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Purpose: The purpose of this study was to investigate whether double‐level (femur + tibia) derotational osteotomy is superior to single‐level femoral derotational osteotomy for recurrent patellar dislocation with severe femoral and tibial rotational deformities (femoral anteversion >30° and external tibial torsion >30°). Methods: Between January 2015 and June 2020, a total of 115 knees with recurrent patellar dislocation treated with combined medial patellofemoral ligament reconstruction (MPFL‐R) and derotational osteotomies were evaluated after a minimum follow‐up of 2 years. Among these cases, 15 knees that underwent double‐level derotational osteotomy were included in the double‐level group, which was propensity‐matched in a 1:2 ratio to a single‐level group of patients who underwent single‐level femoral derotational osteotomy (30 knees). The clinical and radiological outcomes were evaluated and compared between the groups. Furthermore, the foot progression angle was measured preoperatively and 2 years after surgery. Results: The patient‐specific variables did not differ significantly between the double‐ and the single‐level groups after propensity score matching. The postoperative mean foot progression angle was significantly lower in the double‐level group than in the single‐level group (9° ± 8° vs. 15° ± 11°; p = 0.014); however, there were no statistically significant differences between the groups in terms of any other clinical and radiological assessments. Conclusion: For patients with severe femoral and tibial torsional deformities (femoral anteversion >30° and external tibial torsion >30°), the double‐level derotational osteotomy is superior to single‐level osteotomy in maintaining normal foot progression angle, but it does not show an advantage in terms of patient‐reported outcomes, radiological results and redislocation rate at minimum 2 years of follow‐up. Furthermore, concomitant excessive external tibial torsion (>30°) did not have an adverse effect on clinical outcomes in patients who underwent derotational distal femoral osteotomy with MPFL‐R due to excessive femoral anteversion. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Background: Use of a rapid rehabilitation protocol for postoperative recovery after recurrent patellar dislocation (RPD) has gradually gained attention; nonetheless, evidence of its safety and effectiveness is lacking. Purpose: To compare the short-term postoperative outcomes of early rapid rehabilitation with those of conservative rehabilitation in patients with RPD. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 50 patients with RPD who underwent tibial tubercle osteotomy combined with medial patellofemoral ligament reconstruction were enrolled between January 2018 and February 2019. Postoperatively, the patients were randomly assigned to either the early rapid group (rapid group; n = 25 patients) or the conservative group (control group; n = 25 patients) for rehabilitation training. The rapid group underwent faster progression in weightbearing and range of motion (ROM) training. Knee joint functional scores, ROM, bilateral thigh circumference differences, and imaging data were recorded preoperatively and at 6 weeks and 3, 6, 12, and 24 months postoperatively for comparison. Postoperative complications were recorded over the 24-month follow-up period. Results: The baseline data did not significantly differ between the 2 groups. Postoperatively, compared with the control group, the rapid group had higher Tegner scores at 6 weeks and 3 months; higher Lysholm scores at 3 and 6 months; higher International Knee Documentation Committee scores at 6 weeks, 3 months, and 12 months; better ROM; and smaller bilateral thigh circumference differences at 24 months (P <.05 for all). However, no differences were observed in the Tegner, Lysholm, and International Knee Documentation Committee scores at 24 months postoperatively. At the 6-week and subsequent follow-up visits, the Caton and Insall indices were lower in the control group than in the rapid group (P <.01 for all). Moreover, compared with the control group, the rapid group had a lower incidence of patella baja at 24 months (0% vs 17%) and fewer complications during the whole follow-up period (P <.01). Conclusion: Early rapid postoperative rehabilitation appears to be safe and effective for patients who undergo tibial tubercle osteotomy combined with medial patellofemoral ligament reconstruction to treat RPD. In the short term, this approach was shown to be more advantageous than conservative rehabilitation in improving functional scores, allowing an earlier return to daily activities, although the lack of difference at 24 months implies no long-term benefits. In addition, it potentially helped to prevent the occurrence of complications, including patella baja. Registration: ChiCTR1800014648 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Purpose: To explore the relationship between preoperative J‐sign grading and structural bone abnormalities in patients with recurrent patellar dislocation (RPD). Methods: A retrospective study was conducted on RPD patients over 5 years. Patients were categorised based on J‐sign grade into low (J‐ and J1+), moderate (J2+) and high groups (J3+). Trochlear dysplasia (TD) and osseous structures (femoral anteversion angle [FAA], knee torsion, tibial tuberosity‐trochlear groove [TT‐TG] distance, Caton–Deschamps index) were assessed and grouped according to risk factor thresholds. The χ2 test was used to compare composition ratio differences of structural bone abnormalities among the groups. Results: A total of 256 patients were included, with 206 (80.5%) females. The distribution of J‐sign grade was as follows: 89 knees (34.8%) of low grade, 86 moderate (33.6%) and 81 high (31.6%). Among the five structural bone abnormalities, TD was the most common with a prevalence of 78.5%, followed by increased TT‐TG at 47.4%. Excessive tibiofemoral rotation had the lowest occurrence at 28.9%. There were 173 (67.6%) patients who had two or more abnormalities, while 45 (17.6%) had four to five bony abnormalities. Among patients with any bony abnormality, the proportion of high‐grade J‐sign surpassed 40%. Patients with moderate and high‐grade J‐sign had more increased FAA and more pronounced patella alta (all p < 0.001). The proportion of excessive knee torsion and TD increased with increasing each J‐sign grade, with the more notable tendency in knee torsion (high vs. moderate vs. low‐grade: 61% vs. 22% vs 7%, p < 0.001). Furthermore, the higher J‐sign grade was also associated with more combined bony abnormalities (p < 0.001). In the high‐grade J‐sign group, 90.2% of the knees had two or more bony risk factors and 40.7% had four or more, which were significantly higher than the moderate and low‐grade J‐sign groups (40.7% vs. 11.6% vs. 2.2%, p < 0.001). Conclusion: In patients with a high‐grade J‐sign, over 90% of the lower limbs had two or more structural bone risk factors, and more than 40% had four or more. These proportions were significantly higher compared to knees with low‐grade and moderate J‐sign. In clinical practice, when treating high‐grade patellar mal‐tracking, it is important to focus on and correct these strongly correlated abnormal bone structures. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Background: Patellar fracture, femoral physis injury, and recurrent instability are concerning complications in medial patellofemoral ligament (MPFL) reconstruction (MPFLR) techniques for recurrent patellar dislocation in children and adolescents. Purpose: To evaluate the outcomes of an anatomic all–soft tissue fixation technique for reconstruction of the medial patellofemoral complex (MPFC) using a double-bundle quadriceps tendon (QT) autograft for recurrent patellar dislocation in skeletally immature patients. Study Design: Case series; Level of evidence, 4. Methods: This retrospective study involved 24 skeletally immature patients (24 knees; 16 women and 8 men; age range, 9.5-15 years) with recurrent patellar dislocation who underwent MPFC reconstruction using a double-bundle QT autograft between September 2018 and January 2021. Only soft tissue suture fixation was used on the femoral and patellar sides of the 2 bundles of the QT. Radiographs, computed tomography, and magnetic resonance imaging were used to evaluate physeal status, lower limb alignment, patellar height and tilt, trochlear morphology, tibial tubercle-trochlear groove distance, and any associated knee pathology. Functional outcomes were assessed with the Kujala score, the visual analog scale (VAS) for pain, and the grading system of Insall et al.22 Results: The mean follow-up time was 40 ± 9.6 months (range, 28-56 months). At the final follow-up, the Kujala and VAS pain scores showed a significant improvement versus preoperative scores (P <.001), and the passive lateral patellar glide showed a significant reduction (P <.001). All patients had negative apprehension and J signs. Of the 24 patients, 23 regained full range of motion, while 1 patient had a knee flexion deficit. The patellar tilt angle improved significantly at the final follow-up (P <.001). There was no patellar fracture, femoral physis injury, or recurrence of patellar dislocation. According to the grading system of Insall et al, the results were excellent in 15 knees (62.5%), good in 8 knees (33.3%), fair in 1 knee (4.2%), and no knees showed poor results. Conclusion: Reconstruction of the MPFC using a double-bundle QT autograft with an all–soft tissue fixation technique was an effective method for treating patellar instability in skeletally immature patients. [ABSTRACT FROM AUTHOR]

Objective: We aimed to evaluate the effectiveness of modified Aberdeen Weight-Bearing Test (Knee) (AWT-K) and KSS (Knee Society Score) comparing their correlations with the Tegner Lysholm (TL) score in patellar instability patients. Methods: Patients treated for patellar dislocation were divided into two groups. The first group consisted of patients operated on for patellar instability and the second group patients followed by conservative means. Duration of follow-up, age, gender, Caton-Deschamps in)dex, and type of surgical interventions were recorded. Since the TL scoring system was previously validated in the follow-up of patellar instability treatment, the compatibility of KSS and modified AWT-K scoring systems with the TL scoring system was evaluated and their effectiveness in the follow-up of patellar instability was examined. Results: A moderate correlation was found between TL and total KSS scores.However, when the relationship between KSS subgroups ES, SS, OKS, FAS and TL is examined; a weak and moderate correlation was found between the TL scoring system and OKS, SS, and FAS. When weak and non-correlated ES and SS were excluded, there was a strong correlation between TL score and mtKSS.There was a low correlation between TL scores and AWT-K 60-second average load difference and there was a low correlation between FA and AWT-K 60-second mean load difference and ratios. Conclusion: The weak correlation of the AWT-K test for weight-bearing on the knee with findings of KSS and the TL scoring system reveals that may not be an adequate follow-up instrument for patients with patellar instability in short-term follow ups. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to systematically review and quantitatively analyse the clinical outcomes of combined derotational distal femoral osteotomy (D‐DFO) and medial patellofemoral ligament reconstruction (MPFL‐R) in the treatment of recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA). Methods: This study was performed in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) and AMSTAR (Assessing the Methodological Quality Of Systematic Reviews) Guidelines. PubMed, Embase, Web of Science and Cochrane Library databases were searched to identify studies reporting clinical outcomes of combined D‐DFO and MPFL‐R in RPD patients with increased FAA. Data on patient‐reported outcome measures, radiological parameters, patellar tracking as revealed by J‐sign and complications were extracted based on the inclusion criteria. The Methodological Index for Non‐Randomized Study score was used for quality assessment. Review Manager and R statistical software were used to perform the statistical analysis. Results: Eleven studies with a total of 569 knees in 553 patients were included. Patients were predominantly female (79%). The weighted mean of FAA decreased from 33.6° to 13.0° (weighted mean difference = 20.59; p < 0.00001) after the combined procedure. Significant improvements (p < 0.00001) were identified in the Lysholm score (weighted mean: 55.5 vs. 80.4), International Knee Documentation Committee (IKDC) score (weighted mean: 52.8 vs. 78.6) and Kujala score (weighted mean: 54.5 vs. 80.6). The incidence of residual J‐sign ranged from 14.3% to 38.3% with an overall pooled rate of 28.2% (95% confidence interval = 22.8%–33.6%). The overall redislocation rate was 1.1%. No patients experienced surgical site infection or bone nonunion. Two studies compared the clinical outcomes of MPFL‐R with and without D‐DFO. Compared with isolated MPFL‐R, the combined procedure yielded a better Lysholm score (weighted mean: 84.9 vs. 79.3, p < 0.0001), IKDC score (weighted mean: 84.1 vs. 79.9, p = 0.001), Kujala score (weighted mean: 84.3 vs. 79.4, p < 0.0001) and a lower residual J‐sign rate (26/97 [26.8%] vs. 44/105 [41.9%], p = 0.02), respectively. Conclusion: The combination of D‐DFO and MPFL‐R led to improved clinical outcomes and a low redislocation rate in patients with RPD and increased FAA. Additional D‐DFO can achieve more favourable results in subjective function and patellar tracking than isolated MPFL‐R in the setting of excessive FAA. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Background: Surgical correction for recurrent patellar dislocation (RPD) can improve femoral trochlear morphology; nonetheless, the effects of surgical correction on femoral condyle morphology are unclear. Purpose: To investigate the morphological changes in the posterior femoral condyle in skeletally immature patients with RPD and trochlear dysplasia (TD) after surgical correction. Study design: Cohort study; Level of evidence, 3. Methods: A total of 20 skeletally immature patients with bilateral RPD and TD were included in this study. For each patient, the knee that was dislocated more frequently or had sustained a recent injury was treated with medial patellar retinaculum plasty (group S; n = 20 knees), and the asymptomatic or only occasionally dislocated contralateral knee was treated conservatively (group C; n = 20 knees). The lengths of the anterior medial and lateral femoral condyles and the lengths of the posterior medial and lateral femoral condyles were evaluated preoperatively and at the final follow-up. Trochlear morphological characteristics, tibial tuberosity-trochlear groove distance, and patellar tilt angle were compared between preoperative and final follow-up values with the 2-sample paired Student t test and were compared between groups S and C with the independent-samples t test. Results: The mean follow-up time was 60.7 ± 4.8 months. No knee in group S experienced a redislocation, whereas 80% (16/20) of knees in group C experienced a dislocation. There were significant group differences in the ratio of the posterior medial femoral condyle (PMFC) to the posterior lateral femoral condyle (PLFC) (group S, 1.08 ± 0.05; group C, 1.14 ± 0.06; P = .042). There was no significant difference in the ratio of the anterior lateral femoral condyle to the anterior medial femoral condyle (group S, 1.16 ± 0.13; group C, 1.18 ± 0.09; P = .635). In group S, all trochlear morphological characteristics and patellofemoral joint characteristics improved compared with preoperatively (P≤ .047 for all). In addition, all values significantly differed between groups S and C at the final follow-up (P≤ .044 for all). Conclusion: The study findings demonstrated that the morphology of the posterior femoral condyle in skeletally immature patients with bilateral RPD and TD changes after surgical correction, with the PLFC growing faster than the PMFC. [ABSTRACT FROM AUTHOR]

Abstract Background The purpose of current retrospective study was to explore the outcomes of using the adductor magnus tendon to reconstruct the medial patellofemoral ligament in the treatment of recurrent patellar dislocation in children. Method Thirty-two children with recurrent patellar dislocation were selected. Sixteen cases in the conservative group, seven males and nine females, with an average age of 11.81 ± 1.28 years; sixteen cases in the surgical group, eight males and eight females, with an average age of 11.56 ± 1.15 years. All patients had no surgery history. The IS index (> 1.2), Q angle (> 20°) and tibial tubercle–femoral trochlear groove (TT–TG) distance (> 20 mm) were measured by X-ray and MRI. The conservative group was treated with closed reduction and a brace, and the surgical group received surgical treatment. Two years after surgery, congruence angle (CA) (− 6° to 6°) and lateral patellofemoral angle (LPFA) (7.7°–18.7°) were measured by X-ray image and all children were evaluated based on Kujala and Lysholm scores. The re-dislocation rate was recorded. Analysis was performed by t test and chi-square with the statistical SPSS software. P 0.05). Patients in the two groups were followed up for 2 years in average. Among the 16 cases in the conservative group, 7 cases (43.75%) had recurrence of patellar dislocation, while none of recurrence in the surgical group (P

Purpose: To compare clinical outcome between recurrent patellar dislocation (RPD) with or without actual tibial tubercle lateralisation (TTL) after medial patellofemoral ligament reconstruction (MPFL-R) combined with tibial tubercle transfer. Methods: From 2015 to 2018, a total of 172 knees with RPD and a tibial tubercle–trochlear groove (TT–TG) distance of > 20 mm were treated with MPFL-R combined with tibial tubercle transfer. Patients were divided into the lateralisation group (TT–PCL > 24 mm, n = 74) and the nonlateralisation group (TT–PCL ≤ 24 mm, n = 60) based on the presence or absence of actual TTL (TT–PCL > 24 mm). Clinical outcomes were assessed postoperatively at a minimum of 2 years. Second-look arthroscopic evaluations were available for 84 knees to assess cartilage damage. Results: A total of 134 knees with a median follow-up time of 32 months were included. Tibiofemoral rotation (TFR) was significantly higher in the nonlateralisation group than in the lateralisation group (15.4° vs. 9.4°, P < 0.001). At the final follow-up, the nonlateralisation group had significantly lower Kujala (78.2 vs. 86.4, P = 0.001) and Lysholm (80.3 vs. 88.2, P = 0.003) scores than the lateralisation group. At the time of the second-look arthroscopic assessment, 38.9% of the patients in the nonlateralisation group showed cartilage worsening in the medial patellar facet that was significantly higher than that in the lateralisation group (38.9% vs. 12.5%, P = 0.015). Conclusion: Patients with RPD and an increased TT–TG distance of > 20 mm but without actual tibial tubercle lateralisation benefit less from tibial tubercle transfer than patients with actual tibial tubercle lateralisation, which may be related to the significantly higher tibiofemoral rotation angle of the former. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Background: The medial patellofemoral ligament (MPFL) is the most important stabilizer of lateral dislocation of the patella. Single-limb (SL) and double-limb (DL) graft MPFL reconstructions have been increasingly used to treat recurrent patellar dislocations, but the clinical efficacy of SL versus DL graft MPFL reconstructions remains controversial owing to the inconsistent conclusions of previous studies. Purpose: This study aimed to compare the clinical outcomes of SL and DL graft MPFL reconstructions for patients with recurrent patellar dislocation by conducting a meta-analysis of randomized controlled trials and cohort studies. Study Design: Meta-analysis; Level of evidence, 3. Methods: PubMed, Embase, Web of Science, and the Cochrane Library were searched for relevant studies. The retrieval time was up to July 25, 2022. Two evaluators independently screened the literature, extracted data, and assessed the methodological quality of the enrolled studies. Meta-analysis was conducted using RevMan 5.4 software. Results: A total of 4 randomized controlled trials and 3 cohort studies with 451 patients were included. The joint stability and functional scores in both groups improved significantly from baseline. When compared with SL graft reconstruction, DL graft reconstruction provided reduced recurrent instability (P =.01), anterior patella–related pain (P =.02), and patellar lateral shift rate (P =.02). Regarding functional recovery, patients undergoing DL graft reconstruction presented better scores on the Kujala (P <.001), Tegner (P =.009), and International Knee Documentation Committee (IKDC) (P <.001) but similar Lysholm scores as compared with SL graft reconstruction. No statistically significant difference was found between the techniques in the reduction of the patellar tilt angle, complications other than anterior patella–related pain, or postoperative pain. Conclusion: When compared with SL graft MPFL reconstruction, DL graft MPFL reconstruction yielded better outcomes in terms of postoperative recurrent instability, anterior patella–related pain, patellar lateral shift rate, Kujala score, Tegner score, and IKDC score. The amount of high-quality evidence is insufficient, so this conclusion should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Background: The purpose of current retrospective study was to explore the outcomes of using the adductor magnus tendon to reconstruct the medial patellofemoral ligament in the treatment of recurrent patellar dislocation in children. Method: Thirty-two children with recurrent patellar dislocation were selected. Sixteen cases in the conservative group, seven males and nine females, with an average age of 11.81 ± 1.28 years; sixteen cases in the surgical group, eight males and eight females, with an average age of 11.56 ± 1.15 years. All patients had no surgery history. The IS index (> 1.2), Q angle (> 20°) and tibial tubercle–femoral trochlear groove (TT–TG) distance (> 20 mm) were measured by X-ray and MRI. The conservative group was treated with closed reduction and a brace, and the surgical group received surgical treatment. Two years after surgery, congruence angle (CA) (− 6° to 6°) and lateral patellofemoral angle (LPFA) (7.7°–18.7°) were measured by X-ray image and all children were evaluated based on Kujala and Lysholm scores. The re-dislocation rate was recorded. Analysis was performed by t test and chi-square with the statistical SPSS software. P < 0.05 was considered a statistically significant difference. Furthermore, we measured the length (mm) of the adductor tendon and MPFL in three knee cadaveric specimens, and also observed the positional relationship between the two structures. Result: There were no significant differences in sex, age, injury site between groups (P > 0.05). Patients in the two groups were followed up for 2 years in average. Among the 16 cases in the conservative group, 7 cases (43.75%) had recurrence of patellar dislocation, while none of recurrence in the surgical group (P < 0.05). The Lysholm score of the surgical group (94.63 ± 8.99) was significantly better than that of the conservative group (79.31 ± 18.90), and the Kujala score of the surgery group (95.25 ± 10.32) was also significantly better than that of the conservative group (77.06° ± 14.34°) (P < 0.05). The CA and LPFA of the two groups of patients after treatment were significantly recovered. The CA (− 5.81° ± 7.90°) in the surgical group was significantly better than that in the conservative group (20.94° ± 8.21°), and the LPFA (6.44° ± 3.22°) was also significantly better than that in the conservative group (− 9.18 ± 11.08), and the difference is statistically significant (P < 0.05). We found it through autopsy that adductor magnus tendon was 124.33 ± 1.53 mm long, MPFL was 48.67 ± 2.08 mm, and the femoral insertion of the adductor magnus tendon was adjacent to the MPFL femoral insertion. Conclusion: Reconstruction of Medial patellofemoral ligament with the adductor magnus tendon, fixing with PEEK suture anchors on the patellar side, can achieve satisfactory results in the treatment of children with recurrent patellar dislocation. Compared with conservative treatment, the rate of recurrence is lower and the stability of the patella is better. [ABSTRACT FROM AUTHOR]

Purpose: Derotational distal femoral osteotomy (DDFO) has good clinical outcomes for the treatment of the recurrent patellar dislocation combined with increased femoral anteversion angle (FAA). Currently, there is no uniform surgical technique. The purpose of this study was to evaluate the safety and efficacy of computer-aided design (CAD) combined 3D-printed osteotomy guide-assisted DDFO for treating these patients. Methods: In a retrospective study of 36 patients with recurrent patellar dislocation (RPD) from December 2017 to December 2020, all patients had increased FAA and underwent DDFO assisted by CAD combined with a 3D-printed osteotomy guide. Patients' radiological parameters were used to assess the correction of increased femoral torsion and preoperative and postoperative subjective scores were recorded to evaluate the knee function. Complications were recorded to determine the safety of the surgery. Result: A total of 36 knees were included in this study, with a mean follow-up time of 32.6 ± 8.1 months. The mean age of the patients was 24.9±4.4 years and all patients experienced patellar dislocation preoperatively with a mean of 5.7±3.2 times. The patients' femoral anteversion angle decreased from 35.03±3.05° preoperatively to 14.80±0.87°, and the TT-TG distance decreased from 20.03±1.27 mm preoperatively to 19.22±1.22 mm. The hip-knee-ankle (HKA) angle and Insall-Salvatti index were not significantly different postoperatively compared to preoperatively. The knee function scores and visual analogue scale at the last follow-up were significantly improved compared to the preoperative scores. No major complications such as redislocation, nonunion, fixation or graft failure, or infection were observed in any patients. Conclusion: Computer-aided design combined with 3D-printed osteotomy guide-assisted derotational distal femoral osteotomy could correct the increased anterior femoral torsion and demonstrate good results. There were no patients experienced re-dislocation during follow-up period and the overall complication rate is low. [ABSTRACT FROM AUTHOR]

ObjectivesRecurrent patellar dislocation (RPD) greatly affects active young individuals, necessitating the identification of risk factors for a better understanding of its cause. Previous research has connected RPD to lower limb alignment (LEA) abnormalities, such as increased femoral anteversion, tibial external rotation, knee valgus, and flexion. This study aims to use EOS technology to detect RPD-related LEA anomalies, enabling three-dimensional assessment under load conditions.MethodsA total of 100 limbs (50 in the RPD group, 50 in the control group) were retrospectively analyzed. In the RPD group, we included limbs with recurrent patellar dislocation, characterized by dislocations occurs at least two times, while healthy limbs served as the control group. We used EOS technology, including 2D and 3D imaging, to measure and compare the following parameters between the two groups in a standing position: Femoral neck shaft angle (NSA), Mechanical femoral tibial angle (MFTA), Mechanical lateral distal femoral angle (mLDFA), Medial proximal tibial angle (MPTA), Anatomical femoral anteversion (AFA), External tibial torsion (ETT), and Femorotibial rotation (FTR).ResultsThe significant differences between the two groups were shown in NSA 3/2D, MFTA 3/2D, mLDFA 3/2D, MPTA 3D, AFA, FTR. No significant difference was shown in MPTA 2D, ETT between the RPD group and the control group. Further binary logistic regression analysis. Further binary logistic regression analysis was conducted on the risk factors affecting RPD mentioned above. and found four risk factors for binary logistic regression analysis: mLDFA (3D), AFA, NSA(3D), and FTR.ConclusionsEOS imaging identified abnormal LEA parameters, including NSA, MFTA, mLDFA, MPTA, AFA, and FTR, as risk factors for RPD. Children with these risk factors should receive moderate knee joint protection.

Purpose: To propose a new measurement, the patellar shift ratio (PSR), for characterising lateral patellar shift; to determine its diagnostic accuracy in predicting recurrent patellar dislocation (RPD); and to identify the effect of patellar tilt and morphology on shift measurements. Methods: Variables including the PSR, bisect offset (BSO), BSO adjusted by trigonometric analysis, linear patellar displacement (LPD) distance and congruence angle were measured on axial computed tomography (CT). Furthermore, PSR was classified into grades determined by the threshold generated by receiver operating characteristic (ROC) curves. Youden's index was used to identify the ideal threshold on the curve. The area under the ROC curve (AUC) values and likelihood ratios were calculated to assess diagnostic performance in predicting RPD. Correlation analysis was conducted to identify the effects of lateral tilt and the Wiberg index on lateral shift. Intra- and interobserver reliability were evaluated using the intraclass correlation coefficient. Results: The study included 54 RPD patients and 54 controls matched by sex and age. The threshold for PSR was 24.3% (sensitivity, 96.30%; specificity, 85.19%). AUCs were categorised as excellent for all protocols (P < 0.001). The positive likelihood ratio of the PSR for predicting RPD was 6.50. PSR was categorised in terms of lateral trochlear quadrants consisting of 25% increments. Lateral patellar tilt showed a strong positive correlation with BSO (P < 0.001); moderate correlations with PSR, LPD distance and adjusted BSO (P ≤ 0.001); and a weak correlation with congruence angle (P = 0.034). The Wiberg index presented a positive moderate correlation with BSO (P < 0.001), while no correlation was found with PSR, LPD distance, or congruence angle (n.s.). All parameters showed good repeatability (intraobserver) and reproducibility (interobserver). Conclusions: The PSR showed excellent diagnostic performance as indicated by likelihood ratios, measurement accuracy (being relatively resistant to the effects of tilt and the Wiberg index), and intra- and interobserver reliability. The optimal PSR threshold for predicting RPD risk was 24.3%, and the grade of PSR (normal, 1–4) was also a reliable and easily calculated predictor of RPD. This quantifying method to characterise lateral patellar shift is an alternative useful method for clinical assessments of RPD patients and for research on patellofemoral congruence. Level of evidence: Level III [ABSTRACT FROM AUTHOR]

Background: An increased femoral anteversion angle (FAA) is a predisposing factor for recurrent patellar dislocations (RPDs), and combined procedures including derotational distal femoral osteotomy (DDFO) have been shown to be good options. Purpose: To investigate the safety and effectiveness of combined DDFO on clinical and radiological outcomes to treat RPDs with an increased FAA. Study Design: Systematic review; Level of evidence, 4. Methods: This review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. We searched 7 databases for articles from inception to March 10, 2023, that reported outcomes after combined DDFO in patients with an RPD and increased FAA. Two reviewers independently extracted data and assessed study quality. Outcomes evaluated were functional scores, redislocation rates, complications, satisfaction, and radiological parameters. A meta-analysis was performed to pool functional scores, with data reported as mean differences (MDs) and 95% confidence intervals (CIs). Results: Included were 8 studies of 189 knees from 183 patients, with a mean patient age of 22.4 years and a mean follow-up of 33.4 months. The mean preoperative FAA ranged from 31° to 42.70°, and the mean postoperative FAA ranged from 10° to 19.08°. Significant improvements were found in the Kujala score (MD, 26.96 [95% CI, 23.54 to 30.37]), Lysholm score (MD, 26.17 [95% CI, 22.13 to 30.22]), visual analog scale score for pain (MD, –2.61 [95% CI, –3.12 to –2.10]), and Tegner activity score (MD, 1.33 [95% CI, 0.86 to 1.79]). No subluxation or redislocation occurred. The overall complication rate was 10.6%, and most of the complications were pain (60%) and limited knee activity (20%). The overall satisfaction rate was 83.3%. The patellar tilt angle significantly decreased from 40.7° ± 11.9° to 20.5° ± 8.7° and from 26.35° ± 6.86° to 11.65° ± 2.85° in 2 studies. Conclusion: Combined DDFO was found to be safe and effective for the treatment of RPDs and an increased FAA by addressing both patellar dislocations and torsional malalignment. However, because of the lack of comparisons, it remains to be investigated when DDFO should be combined in such patients. [ABSTRACT FROM AUTHOR]

Background: Recurrent patellar dislocation (RPD) and habitual patellar dislocation (HPD) in flexion are frequently encountered in children and adolescents. Purpose: To compare the radiological features of RPD and HPD in children and adolescents. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Imaging data were collected from patients aged 9 to 15 years who received surgical treatment for HPD or RPD at a single institution between June 2015 and September 2020. The prevalence of trochlear dysplasia, tibial tubercle lateralization, and lower limb rotational deformity was assessed through hip/knee/ankle computed tomography (CT) using the following quantitative indicators: trochlear depth index, lateral trochlear inclination, sulcus angle, tibial tubercle–trochlear groove (TT-TG) distance, ratio of TT-TG distance to femoral width, TT-TG angle, femoral anteversion angle, and tibial external rotation angle. The morphology of trochlea and patella were graded on knee CT using the Dejour and Wiberg classification. The Insall-Salvati index and Caton-Deschamps index were used to evaluate the height of the patella on lateral view radiographs. To evaluate lower limbs malalignment, the mechanical lateral distal femoral angle and medial proximal tibial angle were measured on weightbearing full-length radiographs. The collected data were analyzed and compared between the HPD and RPD groups. Results: Enrolled were 15 patients (21 knees) diagnosed with HPD and 18 patients (22 knees) diagnosed with RPD. The age of first dislocation was significantly younger in the HPD group (7.6 ± 3.4 vs 11.2 ± 1.4 years; P = 0.003). Knees in the HPD group had a significantly higher proportion of Dejour type C dysplasia (57.1% vs 4.5%; P <.005) and Wiberg type 3 patella (66.7% vs 9.1%; P <.001). There were statistically significant differences between the groups in the trochlear depth index (HPD vs RPD: 1.1 ± 1.7 vs 2.2 ± 1.5 mm; P =.039), sulcus angle (170.3° ± 13.7° vs 157.3° ± 16.0°; P =.007), Insall-Salvati index (1.1 ± 0.2 vs 1.3 ± 0.2; P =.034), and tibial external rotation angle (31.3° ± 7.8° vs 38.4° ± 8.5°; P =.009). Conclusion: Patients in the HPD group presented with poorer trochlear and patellar development, lower patellar height, and less tibial external rotation compared with patients in the RPG group. [ABSTRACT FROM AUTHOR]

Background: Physiotherapists are often key decision‐makers on when to refer patients with recurrent patellar dislocation for surgical opinion. Limited guidance exists to aid this decision. Differences in orthopaedic surgeons' and physiotherapists' views on which patients and when to refer people for surgical consideration or non‐operative care may affect outcome. This study aimed to explore orthopaedic surgeons and physiotherapists decision‐making surrounding treatment opinions for patients with recurrent patellar dislocation. Methods: An online survey performed. UK registered and practicing orthopaedic surgeons and physiotherapists were invited to participate. The survey utilised two vignettes and a series of related questions to ascertain respondents' views on decision‐making to surgical referral for people with recurrent patellar dislocation. Data were analysed using descriptive statistics and inferential statistical tests to explore factors related to responses. Results: Eighty four respondent surveys were analysed (38 surgeons, 46 physiotherapists). Overall, there was a low level of agreement amongst respondents for the management of the vignettes (k = 0.215, p = < 0.0005). Some disparity existed between the professions on the definition of recurrent patellar dislocations and the clinical features which may require an early surgical assessment. Physiotherapists were three times more likely to delay a surgical opinion for the vignettes presented in this study than the surgeons. Conclusion: This is the first study to investigate orthopaedic surgeons' and physiotherapists' views on decision‐making around surgical or non‐operative management for recurrent patellar dislocations. High‐quality research is required to underpin explicit guidance on decision‐making regarding management of recurrent patellar dislocation. [ABSTRACT FROM AUTHOR]

Abstract Background The aim of the study was to conduct a comprehensive functional and radiological follow-up assessment in patients at least 10 years after adductor magnus MPFL reconstruction, and to assess the presence of early degenerative changes. Methods The mean age at the time of surgery was 16 years (range: 8 to 18 years, SD 2.5). The follow-up examination was performed at least 10 years following adductor magnus MPFL reconstruction (mean 11 years). Twenty-one patients (26 operated knees) attended the follow-up. The mean age at follow-up was 25.1 years (range 20–29 years). Results The significant improvement observed at 3 years, indicated by the Kujala and Lysholm scores, was maintained after 10 years of follow-up (p

Abstract Purpose To investigate the change of the cross-sectional area (CSA) of vastus medialis oblique (VMO) in patients with recurrent patellar dislocation (RPD) treated by tibial tubercle transfer combined with medial patellofemoral ligament (MPFL) reconstruction by imaging methods, and to guide clinical treatment and rehabilitation. Methods From October 2015 to March 2022, 23 patients with RPD who underwent tibial tubercle transfer combined with MPFL reconstruction were retrospectively enrolled. All patients were assessed by CT in the supine position with the knee fully extended and the quadriceps relaxed. The CSA of VMO and the ratio of CSA of VMO to body weight (CSA/BW) were measured at the upper pole of the patella, 5 mm above the upper pole of the patella and 5 mm below the upper pole of patella. The differences of measured parameters were compared before surgery and at follow-up, including CSA of VMO and CSA/BW. Test level α = 0.05. Results The tibial tubercle-trochlear groove (TT-TG) distance was significantly reduced at follow-up compared with that before surgery (27.91 ± 1.95 mm vs 12.33 ± 1.07 mm, P

Objective To investigate the changes in patellar morphology following soft tissue surgical correction of recurrent patellar dislocation in children with low‐grade trochlear dysplasia. Methods The prospective cohort study was performed between November 2007 and December 2012. Finally, 25 cases, with the mean age of 8.4 years (range from 7 to 10 years), were admitted to the study. All patients were diagnosed as bilateral recurrent patellar dislocation associated with femoral trochlear dysplasia. The knee that suffered injury or was dislocated was treated with medial patellar retinacular plasty (surgery group). The contralateral knee, which served as a control, was treated conservatively (conservative group). Axial CT scans were undertaken in all patients to assess the patellar morphological characteristics. Results The mean follow‐up time was 60.8 months (range 48 to 75 months). Preoperatively, there were no statistically significant differences between the patellar morphology in the two groups (P > 0.05). Many radiological parameters of patellar morphology were significantly different between the two groups at the final follow‐up, including well‐known parameters, such as the mean patellar width (surgery group, 40.58 mm [SD 1.26]; conservative group, 36.41 mm [SD 1.17]; P 0.05) at the final follow‐up. No complications were found. Conclusions The patellar morphology can be significantly improved by early soft tissue surgical correction in children with patellar instability associated with low‐grade femoral trochlear dysplasia.

Abstract Background Surgical treatment for recurrent patellar dislocation (RPD) could yield good outcomes. While, unsatisfactory recovery still exists in some cases. For all prognostic factors, serum biomarkers have rarely been investigated. This study aimed to evaluate the prognostic value of preoperative serum calcium level, a widely used serum biomarker, in surgical treatment for RPD. Study design Retrospective study. Methods Ninety-nine patients with RPD were enrolled in the study. Preoperative serum calcium was acquired from routinely tested blood 1 day prior to operation. Demographic data, characteristics of RPD, postoperative functional outcomes were obtained. The association between preoperative calcium and postoperative functional outcomes (Kujala, Lysholm, Tegner, IKDC and KOOS score) was determined by correlation analysis and multivariate linear regression analysis. Poor recovery was determined as Kujala score below 80. The receiver operating characteristic (ROC) curve was used to assess the prognostic value of preoperative calcium. Results Patients were followed up for a mean period of 2.45 ± 1.33 years. All clinical scores showed significant improvement at the latest follow-up. Correlation and multivariate linear analyses indicated that serum calcium level was an important factor related with the prognosis of surgical treatment for RPD. According to the ROC curve, the cut-off value for preoperative calcium was 2.225 mmol/L. The clinical outcomes of patients with a preoperative blood calcium

Background: The aim of the study was to conduct a comprehensive functional and radiological follow-up assessment in patients at least 10 years after adductor magnus MPFL reconstruction, and to assess the presence of early degenerative changes. Methods: The mean age at the time of surgery was 16 years (range: 8 to 18 years, SD 2.5). The follow-up examination was performed at least 10 years following adductor magnus MPFL reconstruction (mean 11 years). Twenty-one patients (26 operated knees) attended the follow-up. The mean age at follow-up was 25.1 years (range 20–29 years). Results: The significant improvement observed at 3 years, indicated by the Kujala and Lysholm scores, was maintained after 10 years of follow-up (p < 0.001). A single recurrence of dislocation was noted in three patients. A significant improvement in radiological parameters was noted. No significant difference in the incidence of chondromalacia, of any degree, was observed compared to controls. Significantly higher quadriceps peak torque was noted for both angular velocities (60 and 180°/sec) compared to the preoperative readings (p < 0.001). Knee flexors were found to be significantly stronger at both 60 and 180°/sec at 10 years follow-up examination (p = 0.008 and p < 0.001 respectively). Conclusion: The use of MPFL reconstruction according to Avikainen yields improvements in clinical and radiological results which are maintained throughout the observation period. No significantly greater articular cartilage degeneration was noted in patients after surgical treatment for recurrent patellar dislocation compared to healthy peers. Trial registration: Registered on Clinical Trails.gov with ID: PMMHRI-BCO.67/2021-A. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the change of the cross-sectional area (CSA) of vastus medialis oblique (VMO) in patients with recurrent patellar dislocation (RPD) treated by tibial tubercle transfer combined with medial patellofemoral ligament (MPFL) reconstruction by imaging methods, and to guide clinical treatment and rehabilitation. Methods: From October 2015 to March 2022, 23 patients with RPD who underwent tibial tubercle transfer combined with MPFL reconstruction were retrospectively enrolled. All patients were assessed by CT in the supine position with the knee fully extended and the quadriceps relaxed. The CSA of VMO and the ratio of CSA of VMO to body weight (CSA/BW) were measured at the upper pole of the patella, 5 mm above the upper pole of the patella and 5 mm below the upper pole of patella. The differences of measured parameters were compared before surgery and at follow-up, including CSA of VMO and CSA/BW. Test level α = 0.05. Results: The tibial tubercle-trochlear groove (TT-TG) distance was significantly reduced at follow-up compared with that before surgery (27.91 ± 1.95 mm vs 12.33 ± 1.07 mm, P < 0.001). The CSA of VMO was significantly increased at follow-up compared with that before surgery at 5 mm below the upper pole of the patella (473.06 ± 106.32 mm2 vs 562.97 ± 157.90 mm2, P < 0.001), at the upper pole of the patella (641.23 ± 188.45 mm2 vs 700.23 ± 177.55 mm2, P = 0.029), and at 5 mm above the upper pole of the patella (788.25 ± 238.62 mm2 vs 849.79 ± 180.84 mm2, P = 0.018). The CSA/BW was significantly increased at follow-up compared with that before surgery at 5 mm below the upper pole of the patella (7.83 ± 2.52 mm2/kg vs 9.22 ± 3.54 mm2/kg, P < 0.001), at the upper pole of the patella (10.48 ± 3.62 mm2/kg vs 11.42 ± 4.14 mm2/kg, P = 0.020), and at 5 mm above the upper pole of the patella (12.86 ± 4.65 mm2/kg vs 13.68 ± 3.86 mm2/kg, P = 0.017). Conclusion: After tibial tubercle transfer combined with MPFL reconstruction, CSA of VMO increased in patients with RPD, which will help to enhance patellar stability and reduce recurrence. [ABSTRACT FROM AUTHOR]

Objectives: The role of the medial patellofemoral ligament (MPFL) as a patellofemoral joint stabilizing structure is undisputable. After traumatic patellar dislocation, MPFL injury, together with bone edema in the medial patellar facet and lateral femoral condyle, is a pathognomonic finding in magnetic resonance imaging (MRI). MPFL injury in the femoral insertion has been reported to most likely predict recurrent dislocations. The objective of this study was to detect if any MPFL injury location predicts the earliest onset of the patellar re-dislocation., Methods: In total, 64 eligible patients with a first-time traumatic patellar dislocation were recruited to the trial. The diagnosis was confirmed within 3 weeks with 3T magnetic resonance imaging. The location of the MPFL injury in MRI was localized at the patellar insertion, midsubstance area, femoral insertion, or a combination of these. During the three-year follow-up period, patellar re-dislocations, range of motion, quadriceps muscle atrophy, and daily symptoms were determined. All the patients were treated non-operatively., Results: Out of 64 patients, 33 (51.6%) had at least one episode of patellar re-dislocation. Re-dislocations occurred in 8 out of 25 (32.0%) patients with the main injury at the femoral insertion, 5 out of 15 (33.3%) patients with the main injury at the midsubstance area, and 10 out of 24 (41.7%) patients with the main injury at the patellar insertion during the 36 months follow-up (p ​= ​0.758). According to Kaplan-Meier analysis, the location of MPFL injury did not have any statistically significant effect on the timing of re-dislocations. At 36 months, survival of patients with MPFL injury at the patellar insertion was 70.8%, which was not statistically significantly different than the survival in patients with injury at the femoral insertion (88.0%) or at the midsubstance area (93.3%). No differences between single and multiple MPFL injuries were found. At 4 weeks, the range of motion was more restricted in patients with MPFL injury at the femoral insertion (93.4° vs. 108.0° for injury at the midsubstance area and 107.7° at the patellar insertion)., Conclusion: The location of MPFL injury did not have any statistically significant effect on timing or the rate of re-dislocations. The MPFL injury at the femoral insertion predicts decreased range of motion (ROM) of the knee and increased quadriceps muscle atrophy during the first three months after sustaining injury., Level of Evidence: Level III., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Abstract Background The purpose of this study was to evaluate the clinical and radiographic outcomes after medial patellofemoral ligament (MPFL) reconstruction combined with supracondylar biplanar femoral derotation osteotomy (FDO) in recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA) and genu valgum. Methods Between January 2017 to December 2020, a total of 13 consecutive patients (13 knees, 4 males and 9 females, mean age 18.7 (range, 15–29 years) with RPD with increased FAA (FAA > 25°) and genu valgum (mechanical axis deformity of ≥5°) who underwent supracondylar biplanar FDO using a Tomofix-locking plate combined with MPFL reconstruction in our institution were included. Preoperative full-leg standing radiographs, lateral views, and hip-knee-ankle computed tomography (CT) scans were used to evaluate the mechanical lateral distal femoral angle (mLDFA), anatomical femorotibial angle (aFTA), mechanical axis, patellar height, tibial tubercle-trochlear groove (TT-TG) distance, and torsional angle of the tibial and femoral in the axial plane. Patient reported outcomes were evaluated using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS), and Tegner score preoperatively and postoperatively. Postoperative CT scans were used to evaluate the changes of FAA and TT-TG, and full-leg standing radiographs was used to evaluate the changes of mLDFA, aFTA, and mechanical axis. Results A total of 13 patients (13 knees) were included with an average follow-up period of 26.7 months (range 24–33). No cases developed wound infection, soft tissue irritation, and recurrent patellar dislocation during the follow-up period after surgery. Bone healing at the osteotomy site was achieved in all cases, and all patients regained full extension and flexion. Clinical outcomes (VAS, Kujala, IKDC, Lysholom, and Tegner scores) improved significantly at the final follow-up after surgery (p 0.05). Conclusion MPFL reconstruction combined with supracondylar biplanar FDO showed satisfactory clinical outcomes and radiographic results in the short-term follow-up period.

Abstract Background The aim of this study was to evaluate patellar morphological changes following surgical correction of recurrent patellar dislocation in children. Methods A total of 35 immature children aged 5 to 10 years who suffered from bilateral recurrent patellar dislocation associated with abnormal patella morphology were enrolled in this study. The knees with the most frequent dislocations (treated with medial patellar retinacular plasty) were selected as the study group (SG), and those undergoing conservative treatment for the contralateral knee were selected as the control group (CG). Computed tomography (CT) scans were performed on all children preoperatively and at the last follow-up to evaluate morphological characteristics of the patella. Results All the radiological parameters of the patella showed no significant difference between the two groups preoperatively. At the last follow-up for CT scans, no significant differences were found for the relative patellar width (SG, 54.61%; CG, 52.87%; P = 0.086) and the relative patellar thickness (SG, 26.07%; CG, 25.02%; P = 0.243). The radiological parameters including Wiberg angle (SG, 136.25°; CG, 122.65°; P

ObjectivesMedial patellofemoral ligament (MPFL) reconstruction is an important surgical therapy for recurrent patellar dislocation. However, few studies have focused on exercise therapy after MPFL reconstruction. Therefore, the first purpose was to compare the active and traditional postoperative exercise therapies on the recovery of knee joint function and reduction of muscle atrophy after MPFL reconstruction, and the second purpose was to compare the active and traditional postoperative exercise therapies on the patellar stability after MPFL reconstruction.MethodsThe cases of 31 patients with recurrent patellar dislocation treated with patella double semi-tunnel anatomical MPFL reconstruction from February 2016 and February 2019 were retrospectively reviewed. The clinical outcomes, including the patellar tilt angle (PTA), lateral patellofemoral angle (LPFA), thigh circumference reduction, Kujala score, and Lysholm score, were compared between two groups (i.e., active exercise and traditional exercise groups) preoperatively, 3 months postoperatively, 6 months postoperatively, 12 months postoperatively, and 24 months postoperatively.ResultsThe Kujala score was significantly higher in the active exercise group than traditional exercise group 3 months postoperatively (80.06 vs. 74.80, P 0.05) or LPFA postoperatively (P > 0.05).ConclusionsOur results suggested that active exercise therapy might benefit the early recovery of knee joint function and reduction of muscle atrophy in patients with recurrent patellar dislocation after MPFL reconstruction.

Objective: To investigate the changes in patellar morphology following soft tissue surgical correction of recurrent patellar dislocation in children with low‐grade trochlear dysplasia. Methods: The prospective cohort study was performed between November 2007 and December 2012. Finally, 25 cases, with the mean age of 8.4 years (range from 7 to 10 years), were admitted to the study. All patients were diagnosed as bilateral recurrent patellar dislocation associated with femoral trochlear dysplasia. The knee that suffered injury or was dislocated was treated with medial patellar retinacular plasty (surgery group). The contralateral knee, which served as a control, was treated conservatively (conservative group). Axial CT scans were undertaken in all patients to assess the patellar morphological characteristics. Results: The mean follow‐up time was 60.8 months (range 48 to 75 months). Preoperatively, there were no statistically significant differences between the patellar morphology in the two groups (P > 0.05). Many radiological parameters of patellar morphology were significantly different between the two groups at the final follow‐up, including well‐known parameters, such as the mean patellar width (surgery group, 40.58 mm [SD 1.26]; conservative group, 36.41 mm [SD 1.17]; P < 0.05), the mean patellar thickness (surgery group, 11.59 mm [SD 0.74]; conservative group, 9.38 mm [SD 0.56]; P < 0.05) and the mean Wiberg index (surgery group, 0.54 [SD 0.06]; conservative group, 0.72 [SD 0.08]; P < 0.05). There are also little‐known parameters, such as the ratio of length of lateral patella to medial patella (surgery group, 1.26 [SD 0.17]; conservative group, 1.69 [SD 0.21]; P < 0.05), which was a measurement of facet asymmetry. However, the Wiberg angle was not significantly different between the two groups (surgery group, 128.63° [SD 9.05]; conservative group, 125.47° [SD 13.96°]; P > 0.05) at the final follow‐up. No complications were found. Conclusions: The patellar morphology can be significantly improved by early soft tissue surgical correction in children with patellar instability associated with low‐grade femoral trochlear dysplasia. [ABSTRACT FROM AUTHOR]

Background: Surgical treatment for recurrent patellar dislocation (RPD) could yield good outcomes. While, unsatisfactory recovery still exists in some cases. For all prognostic factors, serum biomarkers have rarely been investigated. This study aimed to evaluate the prognostic value of preoperative serum calcium level, a widely used serum biomarker, in surgical treatment for RPD.Study Design: Retrospective study.Methods: Ninety-nine patients with RPD were enrolled in the study. Preoperative serum calcium was acquired from routinely tested blood 1 day prior to operation. Demographic data, characteristics of RPD, postoperative functional outcomes were obtained. The association between preoperative calcium and postoperative functional outcomes (Kujala, Lysholm, Tegner, IKDC and KOOS score) was determined by correlation analysis and multivariate linear regression analysis. Poor recovery was determined as Kujala score below 80. The receiver operating characteristic (ROC) curve was used to assess the prognostic value of preoperative calcium.Results: Patients were followed up for a mean period of 2.45 ± 1.33 years. All clinical scores showed significant improvement at the latest follow-up. Correlation and multivariate linear analyses indicated that serum calcium level was an important factor related with the prognosis of surgical treatment for RPD. According to the ROC curve, the cut-off value for preoperative calcium was 2.225 mmol/L. The clinical outcomes of patients with a preoperative blood calcium < 2.225 mmol/L was significantly worse than that with a higher calcium level. The correspondent sensitivity was 0.812 with a specificity of 0.633.Conclusion: Operative treatment for RPD achieved good results, while in some cases the functional scores remain inferior. As a serum biomarker, preoperative calcium could be prognostic for outcomes after surgical treatment for RPD. [ABSTRACT FROM AUTHOR]

Purpose: Recurrent patellar dislocation is a frequent knee disorders in young, active patients. Medial patellofemoral ligament reconstruction (MPFLR) can restore knee stability and function, but the rate of return to sports is less clear. The aim of this study was to evaluate rate of return to sport following treatment of recurrent patellar dislocation with isolated MPFLR. Methods: Between 2011 and 2018, 113 patients with recurrent patellar dislocation were treated with isolated MPFLR at an academic center. Pre-injury sports participation and Tegner score, pre-operative subjective IKDC score, time to return to sports, and post-operative Tegner and subjective IKDC scores were collected, with a minimum of follow-up of 2 years. Results: One hundred and three patients (91%) were evaluated at a mean of 4.5 ± 2.5-year post-operative. 92 patients (89%) participated in sports prior to onset of patellar instability. At final follow-up, 84 of these 92 patients (91%) were able to return to sports. The mean time from surgery to return to sports was 10.4 ± 8.6 months (range: 2–48 months). 62 patients (67%) returned to the same (50 patients) or higher (12 patients) level. 22 patients (26%) returned at a lower level. 19 of these patients attributed this decreased participation to ongoing knee problems. The median Tegner score was noted to decrease from 5 pre-injury to 4 post-operatively (p = 0.02). Conclusion: Isolated MPFL reconstruction allowed return to pre-injury sports in 91% of patients, with 67% of patients returning to the same or higher level than pre-injury. Mean time to return to sports was 10 months and post-operative Tegner score was noted to be modestly decreased from pre-injury level. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Abstract Background Medial patellofemoral ligament reconstruction (MPFLR) is a well-established procedure for addressing recurrent patellar dislocation (RPD) in young patients. However, despite being a promising procedure for RPD with genu valgum, there is a scarcity of reports on simultaneous MPFLR and closing-wedge distal femoral osteotomy (CWDFO). The purpose of the present study was to observe and analyse the clinical and imaging findings of CWDFO combined with MPFLR for RPD with genu valgum. Methods From May 2015 to April 2018, 25 patients with RPD and genu valgum were surgically treated in our department. Anteroposterior long-leg, weight-bearing, lower-extremity radiographs, lateral radiographs and computed tomography (CT) scans of the patellofemoral joint were obtained, and the anatomical femorotibial angle (aFTA), mechanical lateral distal femoral angle (mLDFA), weight-bearing line rate (WBLR), patellar height, patellar lateral shift (PLS) and tibial tubercle–trochlear groove (TT-TG) distance were analysed. Validated knee scores, such as the Kujala, Lysholm, visual analogue scale (VAS) scores and Tegner socres, were evaluated preoperatively and 2 years postoperatively. Results 25 patients, with an average age of 19.8 years (14–27), were evaluated. During the 2-year follow-up period, all patients were able to achieve a better sports level without any problems, with no recurrence of patellar instability. Compared with preoperation, the aFTA, mLDFA, WBLR and PLS showed statistically significant improvement following the procedure (p < 0.001). Meanwhile, no significant differences in the Insall index and TT-TG distance were found. The mean Kujala score, average Lysholm score, VAS score and Tegner socres showed significant postoperative improvement. Conclusions CWDFO combined with MPFLR is a suitable treatment for RPD with genu valgum, and can lead to significant improvement in the clinical and imaging findings of the knee in the short term.

Purpose: The purpose of this study was to evaluate the clinical outcomes of de-rotational distal femoral osteotomy (DDFO) in patients who underwent primary medial patellofemoral ligament reconstruction (MPFLR) failure with increased femoral anteversion along with high-grade J sign. Methods: Between 2011 and 2019, 14 patients underwent DDFO revision surgery due to failed MPFLR. The pre- and postoperative J sign grade, Caton-Deschamps index (CDI), tibial tuberosity–trochlear groove (TT–TG) distance, femoral anteversion angle (FAA), patellar lateral tilt angle (PLTA), MPFL graft laxity, and patient-reported outcomes (Kujala, Lysholm, Tegner, and International Knee Documentation Committee (IKDC) subjective scores) were collected. The anterior–posterior and proximal–distal distances between the actual point and the Schöttle point were also calculated. Results: Fourteen patients underwent MPFLR revision by DDFO combined with MPFLR. The mean PLTA improved from 40.7° ± 11.9° to 20.5° ± 8.7° (P < 0.001). The mean FAA significantly decreased from 42.7° ± 12.0° to 14.1° ± 5.2° (P < 0.001). The mean patellar laxity index (PLI) decreased from 82.4% preoperatively to 15.1% postoperatively (P < 0.001). None of these patients experienced subluxation or re-dislocation during follow-up of 29.7 ± 5.0 months after revision surgery. Meanwhile, the Tegner score at the last follow-up ranged from 3 to 6, with a median of 5. The Kujala, Lysholm, and IKDC subjective scores showed significant improvements, from a mean of 51.0 ± 6.8 preoperatively to 75.4 ± 5.1 postoperatively (P < 0.001), 49.2 ± 7.9 to 75.2 ± 7.2 (P < 0.001), and 42.9 ± 6.2 to 76.8 ± 6.0 (P < 0.001), respectively. The proportion of patients with a high-grade J sign was significantly lower postoperatively than preoperatively (100% vs. 14%). Four out of 14 patients (29%) showed femoral tunnel mal-positioning. Conclusion: MPFLR revision by DDFO combined with MPFLR achieved favorable clinical outcomes in patients with increased femoral anteversion along with high-grade J sign. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Abstract Background The radiological indicators can help doctors determine whether to make tibial tubercle transfer. But which indicator is better is still in question. Methods 117 knees in 103 patients who had undergone patellar surgery and 60 knees in 58 patients who had no history of patellar dislocation from 2014 to 2019 were analyzed. Significant differences of tibial tubercle–trochlear groove (TT-TG) on CT and tibial tubercle–posterior cruciate ligament (TT-PCL) on MRI between the case group and the control group were estimated by an unpaired t test. Significant differences between TT-TG on CT and TT-TG on MRI were estimated by a paired t test. The correlation between TT-PCL on MRI and tibial width was estimated by Pearson test. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were measured to assess the diagnostic accuracy of TT-TG and TT-PCL on MRI. Results The intraclass correlation coefficient (ICC) for TT-TG between CT and MRI evaluated by two raters was were 0.566. When comparing TT-TG on CT with that on MRI, the mean difference was 2.5 mm (p

Abstract Background The purpose of this study was to retrospectively analyze the clinical outcomes of patients with recurrent patellar dislocation who underwent arthroscopic medial patellofemoral ligament (MPFL) reconstruction using gracilis tendon autograft and a modified double-patellar tunnel method. We hypothesized that our modified method would provide good clinical outcomes. Methods Patients who underwent arthroscopic MPFL reconstruction with autograft gracilis tendon and modified double-patellar tunnels technique for recurrent patellar dislocation and were followed up for a minimum of 5 years were identified, and the clinical and follow-up data were retrospectively analyzed. Preoperatively, joint hypermobility was assessed with the Beighton score. The Insall–Salvati ratio, TT–TG distance, and Q angle were measured on radiographic images. Patient-reported outcomes including the Kujala, Lysholm, and Tegner scores were collected preoperatively and postoperatively. Patient satisfaction was assessed at the end of 5 years. Complications and recurrent dislocation occurring after surgery were recorded. Results A total of 79 patients (94 knees) were enrolled; of these, 13 (16.5%) were lost to follow-up. The data of 66 patients (80 knees) were available for final analysis. Mean age at surgery was 21.3 ± 7.8 years. Mean follow-up time was 66.1 ± 5.5 months (range, 60–78 months). Postoperative patient-reported outcome was not associated with Beighton score, Insall–Salvati ratio, or TT–TG distance. Q angle was negatively correlated to Kujala scores and Lysholm scores. Severity of trochlear dysplasia was not associated with postoperative patient-reported outcome. The mean Kujala score increased from 69.4 ± 7.9 to 96.1 ± 1.9, the mean Tegner score increased from 3.1 ± 1.3 to 5.9 ± 1.3, and the mean Lysholm score increased from 73.5 ± 14.6 to 95.3 ± 3.4. Two patients experienced recurrent patellar dislocation during follow-up. Conclusions MPFL reconstruction using autologous gracilis tendon under arthroscopy appears to be a reliable and safe method for treating recurrent patellar dislocation. Level of evidence Level IV.

Purpose: This study compared the radiological characteristics between habitual and recurrent patellar dislocation in skeletally mature patients., Methods: From 2017 to 2019, 77 skeletally mature patients with habitual patellar dislocation were surgically treated at a single institution and reviewed retrospectively. A total of 55 knees from these patients were included in the habitual patellar dislocation group. During the same period, 55 knees with recurrent patellar dislocation were randomly selected from 242 patients and included in the recurrent patellar dislocation group. Various bony deformities were measured and compared between the two groups. Additionally, a subgroup analysis was conducted among patients with habitual patellar dislocation, comparing those with and without an 'invisible patella' observed on true lateral views with 30° of knee flexion., Results: The femoral anteversion angle (21.8° vs. 26.3°, p = 0.041), tibiofemoral rotation angle (9.7° vs. 12.4°, p = 0.042) and external tibial rotation angle (24.3° vs. 29.6°, p = 0.001) in the habitual patellar dislocation group were significantly lower than those in the recurrent patellar dislocation group. 54% of knees in the habitual patellar dislocation group had a patella baja, and this was in sharp contrast to the recurrent patellar dislocation group in which none of the knees had a patella baja. 49.1% of knees in the habitual patellar dislocation group showed 'invisible patella' at 30° of knee flexion, and knees with 'invisible patella' had significantly higher tibial tubercle-trochlear groove (TT-TG) distance (30.4 vs. 19.8, p < 0.001) and tibiofemoral rotation angle (13.2° vs. 6.4°, p < 0.001) than knees with a visible patella., Conclusions: A distinct difference in bony anatomical features was observed between habitual and recurrent patellar dislocation in skeletally mature patients. Habitual patellar dislocation exhibited less severe rotational deformities of the lower extremity but showed poorer trochlear and patellar development, a larger TT-TG distance and a higher incidence of patella baja compared with recurrent patellar dislocation., Level of Evidence: Level III., (© 2024 The Author(s). Knee Surgery, Sports Traumatology, Arthroscopy published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: To report short-term results and clinical outcomes of arthroscopic deepening trochleoplasty combined with medial patellofemoral ligament (MPFL) reconstruction utilizing standard arthroscopic instruments in patients of recurrent patellar dislocation and trochlear dysplasia., Methods: This is a case series of 13 patients between the ages of 14 and 20 years who presented with recurrent patellar dislocation and severe trochlear dysplasia (Dejour grade D). They were treated surgically using an arthroscopic technique from February 2017 to January 2019 and were followed for 18 months. Patients were assessed preoperatively and postoperatively (at 6, 12, and 18 months) with clinical scores (Tegner Activity Score, Lysholm Knee Score, and Kujala Score)., Results: There were 69.2% females, and the mean age was 16.4 ​± ​2.0 years. There were statistically significant improvements in the mean Lysholm and Kujala scores when comparing pre-operative and post-operative scores at every follow-up landmark (p ​< ​0.05). Comparing the preoperative and 18-month postoperative scores-the Lysholm score improved from 68.2 ​± ​10.3 to 98.7 ​± ​2.1 (p ​< ​0.001), and the Kujala score improved from 50.3 ​± ​12.0 to 95.4 ​± ​4.8 (p ​< ​0.001). Five patients were able to achieve premorbid Tegner activity levels at 12 months, with an additional 5 patients achieving the same premorbid Tegner activity at the 18-month mark. The remaining 3 patients were able to attain >90% of their activity level at 18 months' follow-up. No complications were observed during the follow-up period., Conclusions: This proposed arthroscopic deepening trochleoplasty technique combined with MPFL reconstruction has demonstrated excellent and reproducible early clinical outcomes., Level of Evidence: IV., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the clinical and radiographic outcomes after medial patellofemoral ligament (MPFL) reconstruction combined with supracondylar biplanar femoral derotation osteotomy (FDO) in recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA) and genu valgum.Methods: Between January 2017 to December 2020, a total of 13 consecutive patients (13 knees, 4 males and 9 females, mean age 18.7 (range, 15-29 years) with RPD with increased FAA (FAA > 25°) and genu valgum (mechanical axis deformity of ≥5°) who underwent supracondylar biplanar FDO using a Tomofix-locking plate combined with MPFL reconstruction in our institution were included. Preoperative full-leg standing radiographs, lateral views, and hip-knee-ankle computed tomography (CT) scans were used to evaluate the mechanical lateral distal femoral angle (mLDFA), anatomical femorotibial angle (aFTA), mechanical axis, patellar height, tibial tubercle-trochlear groove (TT-TG) distance, and torsional angle of the tibial and femoral in the axial plane. Patient reported outcomes were evaluated using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS), and Tegner score preoperatively and postoperatively. Postoperative CT scans were used to evaluate the changes of FAA and TT-TG, and full-leg standing radiographs was used to evaluate the changes of mLDFA, aFTA, and mechanical axis.Results: A total of 13 patients (13 knees) were included with an average follow-up period of 26.7 months (range 24-33). No cases developed wound infection, soft tissue irritation, and recurrent patellar dislocation during the follow-up period after surgery. Bone healing at the osteotomy site was achieved in all cases, and all patients regained full extension and flexion. Clinical outcomes (VAS, Kujala, IKDC, Lysholom, and Tegner scores) improved significantly at the final follow-up after surgery (p < 0.05). The mean mLDFA, aFTA, mechanical axis, and TT-TG distance showed statistically significant improvement following the combined surgery (p < 0.05), while the CDI did not change significantly after surgery (p>0.05).Conclusion: MPFL reconstruction combined with supracondylar biplanar FDO showed satisfactory clinical outcomes and radiographic results in the short-term follow-up period. [ABSTRACT FROM AUTHOR]

Background: Studies on the clinical outcomes of derotational femoral osteotomy to treat recurrent patellar dislocation in the presence of increased femoral anteversion are limited. Purpose: To investigate the role of derotational femoral osteotomy in the treatment of recurrent patellar dislocation in the presence of increased femoral anteversion. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) by searching the Medline, Embase, Web of Science, and Cochrane Library databases through February 10, 2021. Included were studies of skeletally mature patients presenting with recurrent patellar dislocation and exhibiting increased femoral anteversion who subsequently underwent derotational femoral osteotomy. Methodological quality was assessed using the MINORS (Methodological Index for Nonrandomized Studies) score. The basic characteristics of each study were recorded and analyzed: characteristic information, radiological parameters, surgical techniques, patient-reported outcomes, and complications. Results: A total of 6 studies with 163 patients (170 knees) were included. Sample sizes ranged from 7 to 66 patients, and the patients were predominantly women (range, 79%-100%). The mean age and follow-up ranges were 18 to 28 years and 16 to 44 months, respectively. The mean femoral anteversion decreased significantly from 34° preoperatively to 12° postoperatively. In studies reporting pre- and postoperative outcomes, significant improvements were found in the Lysholm score (from 24.8 to 44.1), Kujala score (from 15.8 to 41.9), International Knee Documentation Committee score (from 11.0 to 28.0), and visual analog scale for pain (from 2.0 to 3.7). All studies reported postoperative complications, giving an overall reported complication rate of 4.7%, but no redislocations occurred during the follow-up period. Conclusion: For recurrent patellar dislocation in the presence of increased femoral anteversion, combination treatment with derotational femoral osteotomy led to favorable clinical outcomes with a low redislocation rate. However, there was no consensus among researchers on the indications for derotational femoral osteotomy in the treatment of recurrent patellar dislocation. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate patellar morphological changes following surgical correction of recurrent patellar dislocation in children. Methods: A total of 35 immature children aged 5 to 10 years who suffered from bilateral recurrent patellar dislocation associated with abnormal patella morphology were enrolled in this study. The knees with the most frequent dislocations (treated with medial patellar retinacular plasty) were selected as the study group (SG), and those undergoing conservative treatment for the contralateral knee were selected as the control group (CG). Computed tomography (CT) scans were performed on all children preoperatively and at the last follow-up to evaluate morphological characteristics of the patella. Results: All the radiological parameters of the patella showed no significant difference between the two groups preoperatively. At the last follow-up for CT scans, no significant differences were found for the relative patellar width (SG, 54.61%; CG, 52.87%; P = 0.086) and the relative patellar thickness (SG, 26.07%; CG, 25.02%; P = 0.243). The radiological parameters including Wiberg angle (SG, 136.25°; CG, 122.65°; P < 0.001), modified Wiberg index (SG, 1.23; CG, 2.65; P < 0.001), and lateral patellar facet angle (SG, 23.35°; CG, 15.26°; P < 0.001) showed statistical differences between the two groups. Conclusions: The patellar morphology can be improved by early surgical correction in children with recurrent patellar dislocation. Therefore, early intervention is of great importance for children diagnosed with recurrent patellar dislocation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this systematic review is to ascertain the reported clinical outcomes and complication profiles of medial patellofemoral ligament (MPFL) reconstruction performed using a superficial "swing-down" quadriceps tendon autograft.Methods: Three databases (PubMed, EMBASE, and MEDLINE) were searched from January 1, 2000, to April 06, 2020. Keywords used in the search included: "medial patellofemoral ligament" and "reconstruction". After screening based on inclusion and exclusion criteria, patient demographics, graft type, outcomes, and complications were extracted. Methodological Index for Non-Randomized Studies criteria were used to assess the quality of each included study.Results: Eleven studies were included, comprising data from 226 patients with mean follow up ranging from 12 to 38 months. All reconstructions used a superficial "swing-down" quadriceps tendon autograft fixed at 20-30 degrees of knee flexion where reported. Eight of eleven studies reported significant improvement in patient reported outcomes such as Kujala score, Lysholm score, and Tegner score. The mean preoperative Kujala score ranged from 35.8 to 82.1 (167 patients), while the mean postoperative Kujala score ranged from 88.4 to 94.8 (197 patients). The mean of the preoperative Lysholm score ranged from 43.3 to 79.3 (77 patients), while the mean of the postoperative Lysholm score ranged from 81.9 to 90.9 (99 patients). The I2 statistic for Lysholm and Kujala scores was 94% and 97%, respectively. Across data reported on 194 patients, there was no incidence of patellar redislocation, patellar fracture, or graft site morbidity.Conclusion: The quadriceps tendon produced improved clinical outcomes with low rates of recurrent postoperative patellar dislocation. These data suggest that the quadriceps tendon remains a suitable alternative for MPFL reconstruction and should remain part of the arsenal of knee ligament surgeons.Level Of Evidence: Systematic review of Level III and IV studies. [ABSTRACT FROM AUTHOR]

Patellofemoral instability is a frequent cause of knee pathology affecting quality of life among the pediatric population. Here, we present a prospective cohort study which included patients who had undergone surgical management using the lateral release and medial imbrication approach (LRMI) or medial patellofemoral ligament reconstruction (MPFL-R). The object of this study was to assess the quality of life among children that have undergone surgical treatment for patellar dislocation. Quality of life was assessed before and after surgery using the Pediatric International Knee Documentation Committee form (Pedi-IKDC), a questionnaire that aims to quantify knee functionality. Postoperative scarring was evaluated using The Stony Brook Scar Evaluation Scale. One hundred and eight patients were selected and grouped according to the type of procedure. Before surgery, the two groups had similar mean Pedi-IKDC scores (41,4 MPFL-R vs. 39,4 LRMI p = 0.314). Improvements were observed in the postoperative scores. The MPFL-R technique showed promising outcomes. When comparing the two surgical groups, there was a significant difference in favor of MPFL-R group (MPFL-R 77.71 points vs. LRMI 59.74 points, p < 0.0001–95% CI (11.22–24.72)). Using the Stony Brook Scar Evaluation Scale, a significant difference in scar quality in favor of MPFL-R was observed (4,5 MPFL-R vs. 2,77 LRMI p = 0.002). In conclusion, this study provides objective evidence-based outcome assessments that support the medial patellofemoral ligament reconstruction technique as the gold standard for patellofemoral instability. [ABSTRACT FROM AUTHOR]

Background: Medial patellofemoral ligament reconstruction (MPFLR) is a well-established procedure for addressing recurrent patellar dislocation (RPD) in young patients. However, despite being a promising procedure for RPD with genu valgum, there is a scarcity of reports on simultaneous MPFLR and closing-wedge distal femoral osteotomy (CWDFO). The purpose of the present study was to observe and analyse the clinical and imaging findings of CWDFO combined with MPFLR for RPD with genu valgum.Methods: From May 2015 to April 2018, 25 patients with RPD and genu valgum were surgically treated in our department. Anteroposterior long-leg, weight-bearing, lower-extremity radiographs, lateral radiographs and computed tomography (CT) scans of the patellofemoral joint were obtained, and the anatomical femorotibial angle (aFTA), mechanical lateral distal femoral angle (mLDFA), weight-bearing line rate (WBLR), patellar height, patellar lateral shift (PLS) and tibial tubercle-trochlear groove (TT-TG) distance were analysed. Validated knee scores, such as the Kujala, Lysholm, visual analogue scale (VAS) scores and Tegner socres, were evaluated preoperatively and 2 years postoperatively.Results: 25 patients, with an average age of 19.8 years (14-27), were evaluated. During the 2-year follow-up period, all patients were able to achieve a better sports level without any problems, with no recurrence of patellar instability. Compared with preoperation, the aFTA, mLDFA, WBLR and PLS showed statistically significant improvement following the procedure (p < 0.001). Meanwhile, no significant differences in the Insall index and TT-TG distance were found. The mean Kujala score, average Lysholm score, VAS score and Tegner socres showed significant postoperative improvement.Conclusions: CWDFO combined with MPFLR is a suitable treatment for RPD with genu valgum, and can lead to significant improvement in the clinical and imaging findings of the knee in the short term. [ABSTRACT FROM AUTHOR]

Objectives To report the clinical outcomes of combined femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation in patients with excessive femoral anteversion. Methods From January 2015 to March 2018, 20 knees in 20 patients (18 female, 2 male) with a mean age of 21 ± 4.2 years (range, 16 to 28 years) were retrospectively reviewed. All patients had undergone femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation and excessive femoral anteversion angle (FAA > 25°). CT and X‐rays were used to assess the correction of the femoral anteversion angle, the tibia tuberosity‐trochlear groove (TT‐TG) distance, patellar tilt, and the congruence angle following the combinatory operations. Subjective scores, such as Kujala, International Knee Documentation Committee (IKDC), Tegner, and visual analogue scale (VAS) scores, were used to evaluate knee function preoperatively and postoperatively. Results No recurrence of patellar dislocation occurred in these patients during an average of 18 months (range, 12 to 23 months) of follow‐up. The mean of the FAA was corrected to 15.80° ± 3.58° postoperatively compared with 31.42° ± 4.95° preoperatively (P

Purpose: Medial patellofemoral ligament (MPFL) reconstruction using the hamstring tendon is widely performed to treat recurrent patellar dislocation. MPFL reconstruction includes a post-operative process of necrosis and reperfusion of the hamstring tendon graft. We hypothesise that the patella gradually shifts laterally because of this process, ultimately affecting the patellofemoral joint alignment. This study aimed to analyse the chronological changes in the patellofemoral joint alignment and the outcomes of MPFL reconstruction. Methods: In this retrospective case-series study, the Knee Society, Lysholm, and Kujala scores were evaluated in 24 consecutive patients (27 knees). To evaluate patellar tracking defects, radiographic indices including the tilting angle, the lateral shift ratio, and the congruence angle were measured before, immediately after, and three, 12, and 36 months after MPFL reconstruction. Results: Post-operative Kujala, Knee Society, and Lysholm scores for the study population significantly improved relative to the pre-operative scores. The tilting and congruence angles at three months after the operation significantly increased relative to those recorded immediately after the operation. The tilting and congruence angles were not significantly different at three, 12, and 36 months after the operation. Conclusions: The post-operative outcomes of MPFL reconstruction for recurrent patellar dislocation were favourable. Insufficient union between the bone tunnel and tendon graft, along with an elongation of the necrotic tendon graft, may change the alignment of the patellofemoral joint within three months after the operation. Therefore, we believe it is necessary to refrain from knee rotation that places lateral stress on the patella until three months after the operation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to analyse the risk factors associated with residual graft laxity after medial patellofemoral ligament reconstruction (MPFL-R) in patients with recurrent patellar dislocation (RPD). Methods: A total of 312 consecutive patients (354 knees) with clinically diagnosed RPD who underwent MPFL-R from 2011 to 2015 were retrospectively analysed. Postoperative MPFL graft stability was assessed with patellofemoral stress radiography, and if the patellar central ridge surpassed the apex of the lateral femoral trochlea, the reconstructed MPFL was defined as having residual graft laxity. Finally, 15 patients who exhibited MPFL residual graft laxity (study group) were matched in a 1:2 fashion to 30 control participants (control group), who showed a normal postoperative patellar stability on stress radiography. Preoperative three-dimensional computed tomography (3D-CT) was used to identify patients with a high-grade J-sign. Femoral tunnel position was assessed using 3D-CT to identify cases with femoral tunnel malposition. Potential predictors of MPFL residual graft laxity, including age, sex, a preoperative high-grade J-sign, femoral tunnel malposition, and several radiological parameters, were assessed by logistic regression analysis. Results: A preoperative high-grade J-sign was identified in 66.7% of the study group, which was significantly higher than that the 13.3% in the control group (P = 0.001). In addition, the presence of a preoperative high-grade J-sign (odds ratio, 11.9 [95% CI, 1.7–82.8]; P = 0.012) and femoral tunnel malposition (odds ratio, 8.2 [95% CI, 1.2–58.0]; P = 0.036) were determined to be independent risk factors associated with residual graft laxity after MPFL-R. Conclusion: The presence of a preoperative high-grade J-sign and femoral tunnel malposition are associated with residual graft laxity after MPFL-R in patients with RPD. These results may provide additional information for counselling patients on residual graft laxity after MPFL-R. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Background: The radiological indicators can help doctors determine whether to make tibial tubercle transfer. But which indicator is better is still in question.Methods: 117 knees in 103 patients who had undergone patellar surgery and 60 knees in 58 patients who had no history of patellar dislocation from 2014 to 2019 were analyzed. Significant differences of tibial tubercle-trochlear groove (TT-TG) on CT and tibial tubercle-posterior cruciate ligament (TT-PCL) on MRI between the case group and the control group were estimated by an unpaired t test. Significant differences between TT-TG on CT and TT-TG on MRI were estimated by a paired t test. The correlation between TT-PCL on MRI and tibial width was estimated by Pearson test. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were measured to assess the diagnostic accuracy of TT-TG and TT-PCL on MRI.Results: The intraclass correlation coefficient (ICC) for TT-TG between CT and MRI evaluated by two raters was were 0.566. When comparing TT-TG on CT with that on MRI, the mean difference was 2.5 mm (p< 0.001). The mean TT-TG difference on CT between the case group and the control group was 5.3 mm, which was significantly bigger than the mean TT-PCL difference on MRI of 1.2 mm(p< 0.001). AUC of TT-TG on CT and TT-PCL were 0.838 and 0.580 (P< 0.001). TT-PCL correlated with tibial width (r=0.450, P< 0.001).Conclusion: A statistically significance and a fair ICC proved that TT-TG could not be used interchangeably. The bigger mean difference between the case group and the control group and better AUC proved that TT-TG on CT might be an indicator more suitable for measuring the lateralization of the tibial tubercle. And TT-PCL should be considered as an individual parameter because of the significant correlation between TT-PCL and tibial width. [ABSTRACT FROM AUTHOR]