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Background: The straight and thin design of the CLS Spotorno stem makes it prone for coronal plane mal-alignment, with potential for cortical impingement; reactive osteogenesis and thigh pain have been documented in this situation with some stems. The literature is scarce about the effect of distal mal-alignment with this particular stem, and its relationship with thigh pain, functional outcomes and stem survival. We assessed functional outcomes with incidence of varus/valgus CLS stem alignment, and correlated stem subsidence of these thin stems with hip scores. Methodology: Hip arthroplasty cases with CLS Spotorno stems, operated between 2015 and 2022, with a minimum follow up of 18 months were evaluated. Radiology included 100% pelvis x-rays with bilateral hips (anteroposterior with 15° internal rotation plus lateral views); parameters documented were coronal mal-alignment, stem subsidence, any pedestal formation and heterotrophic ossification (HO); special note was made of any thigh pain, and functional outcomes were recorded using mHHS and SF-36 scores. Results: We evaluated 65 patients with 79 operated hips at an average follow up of 5.26 years. 31.6% (25/79) stems were neutrally aligned, 64.6% (51/79) were in varus alignment and 3.8% (3/79) were in valgus alignment. The mean subsidence was 3.15 mm + 2.26 and 3 cases had Pedestal formation at the stem tip. There was no correlation between varus/valgus stem positions with the mHHS (p = 0.271) and SF-36 score (p = 0.553), which also did not correlate with the stem subsidence. HO formation was seen in 16 hips (20.3%), but no cases in our series needed revision during follow up. Conclusion: Significant distal malalignment with some subsidence were noted in the hips studied; despite these radiological issues, there were excellent mid-term outcomes and good stems survival, implying that distal malposition may have no bearing on functional outcomes. [ABSTRACT FROM AUTHOR]

Abstract Background Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk. Methods Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest. Subgroup analysis was performed in players with severe varus alignment (> 6°). Results Analysis of the leg axis geometry revealed a mean static alignment of 6.6° ± 2.5 varus and a mean dynamic alignment of 5.1° ± 2.6 varus. Quantitative T2* mapping showed significantly increased T2* values in the superficial cartilage layer compared to the deeper region (p

Knee osteoarthritis is a whole joint disease highlighting the coupling of cartilage and bone adaptations. However, the structural properties of the subchondral bone plate (SBP) and underlying subchondral trabecular bone (STB) in the femoral compartment have received less attention compared to the tibial side. Furthermore, how the properties in the femoral compartment relate to those in the corresponding tibial site is unknown. Therefore, this study aimed to quantify the structural bone and cartilage morphology in the femoral compartment and investigate its association with those of the tibial plateau. Specifically, tibial plateaus and femoral condyles were retrieved from 28 patients with end-stage knee-osteoarthritis (OA) and varus deformity. The medial condyle of tibial plateaus and the distal part of the medial femoral condyles were micro-CT scanned (20.1 μm/voxel). Cartilage thickness (Cart.Th), SBP, and STB microarchitecture were quantified. Significant (P  < <.001; 0.79 ≤  r  ≤ 0.97) correlations with a relative difference within 10% were found between the medial side of the femoral and tibial compartments. The highest correlations were found for SBP porosity (r  = 0.97, mean absolute difference of 0.50%, and mean relative difference of 9.41%) and Cart.Th (r  = 0.96, mean absolute difference of 0.18 mm, and relative difference of 7.08%). The lowest correlation was found for trabecular thickness (r  = 0.79, mean absolute difference of 21.07 μm, and mean relative difference of 5.17%) and trabecular number (r  = 0.79, mean absolute difference of 0.18 mm−1, and relative difference of 5.02%). These findings suggest that the distal femur is affected by OA in a similar way as the proximal tibia. Given that bone adaptation is a response to local mechanical forces, our results suggest that varus deformity similarly affects the stress distribution of the medial tibial plateau and the medial distal femur. [ABSTRACT FROM AUTHOR]

Background: Contributors to knee degeneration include mechanical axis malalignment, patellar maltracking, meniscal deficiency, and tibiofemoral instability. Full-thickness osteochondral defects in young, active patients can lead to significant pain and instability. The gold standard treatment for large (>2 cm2) osteochondral defects is an osteochondral allograft (OCA) which addresses the pathologic articular cartilage loss and underlying bone deficiency. While biologic failure of fresh OCAs is reported, the majority of early failures are attributed to unaddressed mechanical malalignment in the coronal plane. Proximal tibial osteotomy (PTO) corrects malalignment thereby unloading the affected medial compartment and the newly placed OCA, improving long-term survivability. Indications: OCAs are indicated for isolated osteochondral defects and lesions in active young patients. PTO is indicated for patients with varus malalignment who risk potential graft failure of the affected medial compartment. Technique Description: The articular cartilage defect is identified, and a guide pin is drilled in the center. The defect is templated and scored around the margins. A reamer is used to drill to a total depth of 7 to 8 mm. The recipient site is then dilated for graft insertion. On the donor graft, the harvest site is outlined and drilled to the proper diameter. Careful measurement is utilized to ensure graft depth measurements match the recipient site. Once sized, the graft is tapped into place obtaining an anatomic fit along its entire periphery. The osteotomy is performed by using guide pins to delineate the plane cutting the tibia. Fluoroscopy confirmed the osteotomy site and angle. A spacing plate was securely inserted with screws, with placement confirmed by fluoroscopy. Results: Fresh OCAs can restore osteochondral defects. PTO corrects malalignment and unloads the affected medial compartment, decreasing the risk of revision graft failure or total knee arthroplasty. Discussion: Clinical and biomechanical studies that compared isolated and concomitant procedures demonstrated that OCA with PTOs had significantly greater survival rates. Significant malalignment increases the risk of graft failure. It remains unclear whether concomitant osteotomy with osteoarticular allografts leads to increased complication risk; inherent risks remain associated with individual procedures. In adolescents, simultaneous corrective osteotomy along with fresh OCA may delay arthroplasty and associated ambulatory restrictions. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication. [ABSTRACT FROM AUTHOR]

Background: Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk. Methods: Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest. Subgroup analysis was performed in players with severe varus alignment (> 6°). Results: Analysis of the leg axis geometry revealed a mean static alignment of 6.6° ± 2.5 varus and a mean dynamic alignment of 5.1° ± 2.6 varus. Quantitative T2* mapping showed significantly increased T2* values in the superficial cartilage layer compared to the deeper region (p < 0.001) as well as a significant increase in relaxation times in the femoral cartilage from anterior to intermediate to posterior (p < 0.001). Combination of both methods revealed a significant correlation for the degree of varus alignment and the femoral, posterior, deep region of the medial knee compartment (r = 0.4; p = 0.03). If severe varus alignment was present this region showed a significant increase in relaxation time compared to players with a less pronounced leg axis deviation (p = 0.003). Conclusion: This study demonstrates that varus alignment in young soccer players is associated with elevated T2* relaxation times in the deep cartilage layer of the medial, posterior, femoral compartment and might therefore be a contributing factor in the early pathogenesis of manifest cartilage lesions. Therefore, these findings should be considered in the development of preventive training programs. [ABSTRACT FROM AUTHOR]

Subtrochanteric femoral (ST) fractures are associated with high rates of delayed and non-union. The aim of this study was to analyse the risk factors associated with delayed/non-union in ST fractures. All patients with surgical stabilisation of ST fractures during the period 2014 to 2019 were identified in an electronic patient records database in two trauma centres. Exclusion criteria were incomplete clinical/radiological data, pathological fractures and loss to follow-up. Radiographs at about 6 months post-surgery were assessed for fracture union using Radiographic Union Score for Hip (RUSH). Fracture was deemed to be un-united if RUSH score was <18. CCD (caput-collum-diaphyseal) angle of operated and uninjured hip, residual displacement at fracture site and 3-point relationship was calculated on operative or immediate post-operative images in both groups. Student's t-test was used to compare CCD angle difference between operated and uninjured sides and the residual fracture displacement between delayed union and united fractures group. Chi-square test was used for 3-point relationship. Observational analysis was performed on implant failure rates including distal screw breakage. During the study period, there were total of 278 patients. 193 with inadequate data and 22 with pathological fractures were excluded. Advanced age and female sex had significantly higher rate of delayed union (p value of 0.043 and 0.003 respectively). Delayed union group (26) had a mean RUSH score of 14.1 and united group (37) had a mean RUSH score of 26.3 (p = 0.019). The mean CCD angle difference between operated and uninjured sides was −5.77° for delayed union and −2.33° for united fractures (p = 0.03). Residual displacement at fracture site showed statistically significant difference between delayed union and united fractures on anteroposterior and lateral views (p = 0.001 each). There was no statistical difference in 3-point relationship of implant in two groups (p = 0.775). 10 revision procedures were performed for implant failures. Distal screw failure (3 cases) was not a precursor for non-union in this study. This study confirms varus alignment of hip and residual fracture displacement after fracture fixation of subtrochanteric fracture are surgeon associated significant risk factors for delayed union at 6 months. Fracture contact and alignment are key to reduce failures in these group of fractures. Among patient factors, advancing age and female sex predisposes to higher rate of delayed union. [ABSTRACT FROM AUTHOR]

Abstract Background Medial meniscal posterior root tear (MMPRTs) is a common lesion of the knee joint, and repair surgery is a well-established treatment option. However, patients with obvious varus alignment are at an increased risk for MMPRT and can suffer from a greater degree of medial meniscus extrusion, which leads to the development of osteoarthritis following repair. The efficacy of high tibial osteotomy (HTO) as a means of correcting this malformation, and its potential benefits for MMPRT repair, remains unclear. Purpose To explore whether HTO influenced the outcome of MMPRT repair in clinical scores and radiological findings. Study design Systematic review. Methods According to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of MMPRT repair and extracted data about characteristics of patients, clinical functional scores and radiologic outcomes. One reviewer extracted the data and 2 reviewers assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the results of MMPRT repair with exact mechanical axis (registered in the International Prospective Register of Systematic Reviews, CRD42021292057). Results Fifteen studies with 625 cases of high methodological quality were identified. Eleven studies were assigned to the MMPRT repair group (M) with 478 cases performing MMPRT repair only, and others belonged to the MMPRT repair and HTO group (M and T) performing HTO and MMPRT repair. Most of the studies had significantly improved clinical outcome scores, especially in M groups. And the radiologic outcomes showed that the osteoarthritis deteriorated in both groups with similar degree in about 2-year follow-up. Conclusion HTO is a useful supplement in treating MMPRT patients with severe osteoarthritis and the clinical and radiological outcomes were similar with MMPRT repair alone. Which would be better for patients’ prognosis generally, performing MMPRT repair alone or a combination of HTO and MMPRT repair, was still controversial. We suggested taking K-L grade into account. Large-scale randomized control studies were called for in the future to help make better clinical decisions. Level of evidence III

Abstract Background Patients with severe obesity [body mass index (BMI) ≥ 40 kg/m2] potentially overload the tibial component after total knee arthroplasty (TKA), risking tibial subsidence. Using a cemented single-radius cruciate-retaining TKA design, this study compared the outcomes of two tibial baseplate geometries in patients with BMI ≥ 40 kg/m2: standard keeled (SK) or universal base plate (UBP), which incorporates a stem. Methods This was a retrospective, single-centre cohort study with minimum 2 years follow-up of 111 TKA patients with BMI ≥ 40 kg/m2: mean age 62.2 ± 8.0 (44–87) years, mean BMI 44.3 ± 4.6 (40–65.7) kg/m2 and 82 (73.9%) females. Perioperative complications, reoperations, alignment and patient-reported outcomes (PROMS): EQ-5D, Oxford Knee Score (OKS), Visual Analogue Scale (VAS) pain score and satisfaction were collected preoperatively, and at 1 year and final follow-up postoperatively. Results Mean follow-up was 4.9 years. SK tibial baseplates were performed in 57 and UBP in 54. There were no significant differences in baseline patient characteristics, post-operative alignment, post-operative PROMs, reoperations or revisions between the groups. Three early failures requiring revision occurred: two septic failures in the UBP group and one early tibial loosening in the SK group. Five-year Kaplan–Meier survival for the endpoint mechanical tibial failure was SK 98.1 [94.4–100 95% confidence interval (CI)] and UBP 100% (p = 0.391). Overall varus alignment of the limb (p = 0.005) or the tibial component (p = 0.031) was significantly associated with revision and return to theatre. Conclusions At early to mid-term follow-up, no significant differences in outcomes were found between standard and UBP tibial components in patients with BMI ≥ 40 kg/m2. Varus alignment of either tibial component or the limb was associated with revision and return to theatre.

Recent studies highlighted the crucial contribution of subchondral bone to OA development. Yet, only limited data have been reported on the relation between alteration to cartilage morphology, structural properties of the subchondral bone plate (SBP) and underlying subchondral trabecular bone (STB). Furthermore, the relationship between the morphometry of the cartilage and bone in the tibial plateau and the OA-induced changes in the joint’s mechanical axis remains unexplored. Therefore, a visualisation and quantification of cartilage and subchondral bone microstructure in the medial tibial plateau was performed. End stage knee-OA patients with varus alignment and scheduled for total knee arthroplasty (TKA) underwent preoperative fulllength radiography to measure the hip-knee-ankle angle (HKA) and the mechanical-axis deviation (MAD). 18 tibial plateaux were μ-CT scanned (20.1 μm/voxel). Cartilage thickness, SBP, and STB microarchitecture were quantified in 10 volumes of interest (VOIs) in each medial tibial plateau. Significant differences (p < 0.001) were found for cartilage thickness, SBP, and STB microarchitecture parameters among the VOIs. Closer to the mechanical axis, cartilage thickness was consistently smaller, while SBP thickness and STB bone volume fraction (BV/TV) were higher. Moreover, trabeculae were also more superior-inferiorly oriented, i.e. perpendicular to the transverse plane of the tibial plateau. As cartilage and subchondral bone changes reflect responses to local mechanical loading patterns in the joint, the results suggested that region-specific subchondral bone adaptations were related to the degree of varus deformity. More specifically, subchondral sclerosis appeared to be most pronounced closer to the mechanical axis of the knee.

Background: Medial meniscal posterior root tear (MMPRTs) is a common lesion of the knee joint, and repair surgery is a well-established treatment option. However, patients with obvious varus alignment are at an increased risk for MMPRT and can suffer from a greater degree of medial meniscus extrusion, which leads to the development of osteoarthritis following repair. The efficacy of high tibial osteotomy (HTO) as a means of correcting this malformation, and its potential benefits for MMPRT repair, remains unclear. Purpose: To explore whether HTO influenced the outcome of MMPRT repair in clinical scores and radiological findings. Study design: Systematic review. Methods: According to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of MMPRT repair and extracted data about characteristics of patients, clinical functional scores and radiologic outcomes. One reviewer extracted the data and 2 reviewers assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the results of MMPRT repair with exact mechanical axis (registered in the International Prospective Register of Systematic Reviews, CRD42021292057). Results: Fifteen studies with 625 cases of high methodological quality were identified. Eleven studies were assigned to the MMPRT repair group (M) with 478 cases performing MMPRT repair only, and others belonged to the MMPRT repair and HTO group (M and T) performing HTO and MMPRT repair. Most of the studies had significantly improved clinical outcome scores, especially in M groups. And the radiologic outcomes showed that the osteoarthritis deteriorated in both groups with similar degree in about 2-year follow-up. Conclusion: HTO is a useful supplement in treating MMPRT patients with severe osteoarthritis and the clinical and radiological outcomes were similar with MMPRT repair alone. Which would be better for patients' prognosis generally, performing MMPRT repair alone or a combination of HTO and MMPRT repair, was still controversial. We suggested taking K-L grade into account. Large-scale randomized control studies were called for in the future to help make better clinical decisions. Level of evidence: III [ABSTRACT FROM AUTHOR]

Background: Patients with severe obesity [body mass index (BMI) ≥ 40 kg/m2] potentially overload the tibial component after total knee arthroplasty (TKA), risking tibial subsidence. Using a cemented single-radius cruciate-retaining TKA design, this study compared the outcomes of two tibial baseplate geometries in patients with BMI ≥ 40 kg/m2: standard keeled (SK) or universal base plate (UBP), which incorporates a stem. Methods: This was a retrospective, single-centre cohort study with minimum 2 years follow-up of 111 TKA patients with BMI ≥ 40 kg/m2: mean age 62.2 ± 8.0 (44–87) years, mean BMI 44.3 ± 4.6 (40–65.7) kg/m2 and 82 (73.9%) females. Perioperative complications, reoperations, alignment and patient-reported outcomes (PROMS): EQ-5D, Oxford Knee Score (OKS), Visual Analogue Scale (VAS) pain score and satisfaction were collected preoperatively, and at 1 year and final follow-up postoperatively. Results: Mean follow-up was 4.9 years. SK tibial baseplates were performed in 57 and UBP in 54. There were no significant differences in baseline patient characteristics, post-operative alignment, post-operative PROMs, reoperations or revisions between the groups. Three early failures requiring revision occurred: two septic failures in the UBP group and one early tibial loosening in the SK group. Five-year Kaplan–Meier survival for the endpoint mechanical tibial failure was SK 98.1 [94.4–100 95% confidence interval (CI)] and UBP 100% (p = 0.391). Overall varus alignment of the limb (p = 0.005) or the tibial component (p = 0.031) was significantly associated with revision and return to theatre. Conclusions: At early to mid-term follow-up, no significant differences in outcomes were found between standard and UBP tibial components in patients with BMI ≥ 40 kg/m2. Varus alignment of either tibial component or the limb was associated with revision and return to theatre. Highlights: Favourable knee arthroplasty outcomes in BMI ≥ 40 kg/m2 with different tibial baseplates. No overt advantage of UBP over standard keeled tibia in patients with BMI≥40kg/m2, though may be underpowered to demonstrate this. Varus alignment of tibial component or limb associated with increased revision rate. Further research needed to investigate theoretical benefit of longer tibial stem. [ABSTRACT FROM AUTHOR]

Background and Objectives: Clinically, it is beneficial to determine the knee osteoarthritis (OA) subtype that responds well to conservative treatments. Therefore, this study aimed to determine the differences between varus and valgus arthritic knees in the response to conservative treatment. We hypothesized that valgus arthritic knees would respond better to conservative treatment than varus arthritic knees. Materials and Methods: Medical records of 834 patients who received knee OA treatment were retrospectively reviewed. Patients with Kellgren–Lawrence grades III and IV were divided into two groups according to knee alignment (varus arthritic knee, hip-knee-ankle angle [HKA] > 0° or valgus arthritic knee, HKA < 0°). The Kaplan–Meier curve with total knee arthroplasty (TKA) as an endpoint was used to compare the survival probability between varus and valgus arthritic knees at one, two, three, four, and five years after the first visit. A receiver operating characteristic (ROC) curve was used to compare the HKA thresholds for TKA between varus and valgus arthritic knees. Results: Valgus arthritic knees responded better to conservative treatment than varus arthritic knees. With TKA as an endpoint, the survival probabilities for varus and valgus arthritic knees were 24.2% and 61.4%, respectively, at the 5-year follow-up (p < 0.001). The thresholds of HKA for varus and valgus arthritic knees for TKA were 4.9° and −8.1°, respectively (varus: area under the ROC curve [AUC] = 0.704, 95% confidence interval [CI] 0.666–0.741, p < 0.001, sensitivity = 0.870, specificity = 0.524; valgus: AUC = 0.753, 95% CI 0.693–0.807, p < 0.001, sensitivity = 0.753, specificity = 0.786). Conclusions: Conservative treatment is more effective for valgus than for varus arthritic knees. This should be considered when explaining the prognosis of conservative treatment for knees with varus and valgus arthritis. [ABSTRACT FROM AUTHOR]

• Interactions between hip and foot factors predict the magnitude of foot pronation. • These interactions of foot and hip factors are non-linear. • The profiles help clinicians identify how these factors interact in walking. Interactions between hip and foot biomechanical factors may result in different magnitudes of foot pronation during walking. To investigate non-linear interactions between hip and foot biomechanical factors and their capability to predict foot pronation during walking and identify the profiles of biomechanical factors that predict greater and lower pronation. This is a cross-sectional study. Fifty-one women were classified into greater and lower foot pronation during walking. Biomechanical factors measured: (1) foot-ankle varus alignment, (2) hip passive stiffness, (3) isokinetic eccentric strength of hip external rotators, and (4) foot abduction angle. Classification and regression trees (CART) were used to investigate non-linear interactions that predict greater and lower foot pronation. Four main profiles of biomechanical factors were identified as related to greater and lower foot pronation. Profiles for greater pronation were: (1) varus >25.83°; (2) interaction between varus ≤25.83° and hip stiffness ≤0.09 Nm/rad kg-1; (3) interaction between varus ≤25.83°, hip stiffness >0.09 Nm/rad kg-1, and foot abduction >19.58° The profile for lower pronation involved an interaction among varus ≤25.83°, hip stiffness >0.09 Nm/rad kg-1, and foot abduction ≤19.58° The model had 61% sensitivity and 96% specificity, with the total prediction of 78%. The area under the ROC curve was 0.79 (p = 0.001). Foot-ankle varus, hip passive stiffness, and foot abduction predicted greater and lower foot pronation. Non-linear interactions between hip and foot factors influence the magnitude of foot pronation during walking. The observed profiles help identify which combinations of biomechanical factors should be assessed in individuals with increased or reduced pronation. [ABSTRACT FROM AUTHOR]

Comparing mainly clinical and functional outcomes as well as prosthesis survival with neutral and residual mild varus alignment, we searched PubMed, Embase, Cochrane Library and Web of Science databases from 1 January 1974 to 18 December 2020 to identify studies comparing clinical and functional outcomes as well as prosthesis survival in the presence of different alignments after total knee arthroplasty (TKA) for varus knees. The included studies were assessed by two researchers according to the Newcastle–Ottawa Scale (NOS). Postoperative neutral alignment (0° ± 3°) was compared to residual mild varus (3°–6°) and residual severe varus (>6°). Meta‐analysis was performed using Review Manager 5.3. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables. The fixed‐effect model and random‐effect model were used to meta‐analyze the data. Nine studies were included in the meta‐analysis with 1410 cases of postoperative neutral alignment, 564 of residual mild varus alignment and 175 of residual severe varus alignment following TKA, all of which were published after 2013. Three studies scored 7 points on the NOS, while the remaining studies scored 8 points, suggesting high quality. The pooled mean differences (MDs) of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were 1.07 [95% confidence interval (CI) −1.06 to 3.20; P = 0.32; I2 = 79%]. The meta‐analysis showed that neutral alignment and mild varus alignment were associated with similar the Oxford Knee Score (OKS), Knee Society Knee Score (KS‐KS), and Knee Society Function Score (KS‐FS), while neutral alignment was associated with lower Forgotten Joint Score (FJS) [mean difference −6.0, 95% confidence interval (CI) −9.37 to −2.64, P = 0.0005]. Neutral alignment was associated with higher KS‐KS than severe alignment (M 2.98, 95% CI 1.42 to 4.55, P = 0.0002; I2 = 0%) as well as higher KS‐FS (M 8.20, 95% CI 4.58 to 11.82, P

Introduction: Varus positioning is the most common femoral malposition in total hip arthroplasty (THA). We compared the long-term outcomes of an anatomical cementless femoral stem positioned in varus versus neutral alignment. Materials and methods: Data were retrospectively reviewed for all patients receiving a cementless anatomical femoral stem in THA for osteoarthritis between 1998 and 2008. Exclusion criteria were complex cases, incomplete data or follow-up < 1 year. Primary outcome was survival rate with complications and secondary outcomes were clinical scores, thigh pain, radiological score, cortical hypertrophy and filling rate. Results: Of the 283 included patients, 127 stems were classified as varus and 156 neutral. Mean follow-up was 10 years. Femoral stem size was smaller in the varus group (4.1 vs. 4.4, p = 0.047). A stem-filling rate < 80% was more frequent in the varus group (p < 0.001). The long-term survival rate without any revision procedure was 94.8% ± 2.3% (95%CI 88.4–98.7) in the varus group and 94.1% ± 2.0% (95%CI 91.3–99.1) in the neutral group (p = 0.55). There was no difference in clinical scores, thigh pain or complication occurrence between groups. The Engh–Massin score was lower in the varus group (p < 0.01) and cortical hypertrophy was higher (p < 0.001). Conclusions: A varus alignment of a cementless anatomic femoral stem does not affect survivorship, clinical outcomes or complication rate on an average follow-up of 10 years, despite increasing stress-shielding rates. [ABSTRACT FROM AUTHOR]

Background: This study investigated bone mineral density (BMD) around the knee joint to clarify the mechanism by which tibia deformation exceeds that of the femur in patients with end-stage knee osteoarthritis (KOA)., Methods: We retrospectively analyzed 193 patients who underwent total knee arthroplasty for end-stage KOA with varus alignment. Preoperative T-score of the femur neck and femur total using dual-energy X-ray absorptiometry (DXA) and hounsfield units (HU) of the distal femur and proximal tibia using computed tomography (CT) were measured to asess the BMD. HU was measured by dividing the femur and tibia into medial, lateral, and total parts, respectively. Patients with medial proximal tibial angle (MPTA) ≥ 85° were considered 'group 1', and MPTA < 85° were 'group 2'. The HU between femur and tibia were compared in group 1. T-score, HU, and HU difference between group 1 and group 2 were compared., Results: The HU of the proximal tibia was lower than that of the distal femur (femur lateral > femur medial > tibia medial > tibia lateral). T-score (femur neck, femur total) and HU (femur lateral, femur total, tibia lateral) were lower in group 2 than in group 1. There was no difference in femur-tibia HU difference between groups., Conclusion: The medial tibia collapse more than the medial femur in varus endstage KOA was associated with the lower BMD of the proximal tibia than that of the distal femur, and the MPTA collapse was affected by the absolute value of BMD rather than by the femur-tibia BMD difference., 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 Elsevier B.V. All rights reserved.)

Purpose: The purpose of this retrospective study was to evaluate the effect of varus alignment of the tibial component on the outcomes with a minimum follow-up of 10 years. The hypothesis was that varus alignment of the tibial component might not affect the outcomes and survival of a neutrally aligned primary TKA. Methods: A matched case–control study was designed between 66 patients with varus alignment of the tibial component and 66 with neutral alignment with a minimum follow-up of 10 years. Functional outcome was assessed with the knee surgery scores (KSS) and reduced Western Ontario and MacMaster Universities questionnaire (WOMAC). Patient satisfaction was evaluated by a 0–10 visual analog scale. Radiological evaluation was performed at early postoperative and at final follow-up. Results: The mean follow-up was 11.9 (SD 2.6) years for both groups. The mean postoperative proximal tibial angle in the varus group was 85.0° (SD 0.9) and 88.8° (SD 0.9) in control group. At the final follow-up, there were no significant differences in KSS, WOMAC, range of motion or patient satisfaction. There were no differences in the coronal anatomical alignment of the TKA between groups. Revision of TKA was performed in four knees in the varus group, and one in control group, due to aseptic loosening of the tibial component in all cases. TKA survival at 10 years was not significantly different between groups. Conclusion: The alignment of the tibial component up to 7° varus did not negatively affect implant survival, patient satisfaction, and function of a well-aligned TKA, with a minimum postoperative follow-up of 10 years. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Background. This study aims to analyze the tibial component using the finite element method by cutting the tibial in frontal and sagittal planes at an angle between 1.5° (valgus and anterior tilt) and -1.5° (varus and posterior tilt). Methods. This experimental study used the finite element method as an useful tool for simulating the positioning of the tibial component in order to create a personal pre-operative planning. For the finite element method analysis, a geometrical model of a tibia from a cadaver was three – dimensionally scanned and the tibial component, polyethylene and cement, were three-dimensionally shaped in Computer-Aided Design program using material data such as Young modulus (gigapascal – GPa) and the Poisson coefficient. The analysis determined the equivalent von Mises stress, the maximum displacement of the components and the equivalent von Mises deformation. The results showed that equivalent tension and deformation have higher values in the tibia and the polyethylene, which deform faster than cement and the tibial component. In our study, we chose to simulate the tibial resection at a cutting angle ± 1.5° from neutral positioning (which is represented in frontal plane by the perpendicular on the mechanical axis and in sagittal plane by the posterior slope of 7 degree) in frontal and sagittal plane in order to find the minimum threshold from which the tibial component malalignment may begin to determine unfavorable effects. Results. Our results have shown detrimental effects begin to appear for the polyethene component at -1.5° in frontal plane, and the rest of the components at 1.5° in sagittal plane. Conclusion. This finding leads us to propose preoperative planning based on personal calculus of predefined angles, which may show the surgeon the optimal implantation position of the tibial component.

Purpose: Whether the inclined articular surface on the medial proximal tibia and the external knee adduction moment (KAM) correlate remains unclear. The hypothesis was that a steeper inclined articular surface correlated with a larger KAM in advanced knee osteoarthritis (OA). Methods: A total of 44 females (non-OA, 9 knees; early OA, 14 knees; advanced OA, 21 knees; mean age, 58 ± 16 years) were examined. Three-dimensional (3D) assessment was used on biplanar long-leg radiographs and 3D bone models using a 3D to 2D image registration technique. The approximation plane in the proximal tibia was determined using the least-square method. The joint moments were mathematically calculated in a gait analysis, applying a motion capture system and force plates. The main evaluation parameters were the femorotibial angle (FTA), the coronal inclination of the approximation plane in the medial proximal tibia (coronal inclination), and internal knee joint moments. The KAM means the external moments balanced with the internal knee abduction moments. Results: The advanced OA showed a larger internal abduction moment (p = 0.017) at the loading response than the other groups. The larger FTA and steeper coronal inclination correlated with the larger internal abduction moment (FTA, p < 0.001; coronal inclination, p = 0.003) at the loading response. Conclusions: As the clinical relevance, the association among the coronal inclination of the medial proximal tibia, lower extremity alignment, and KAM is one of the key factors to help better understand the etiology of knee OA. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Comparing mainly clinical and functional outcomes as well as prosthesis survival with neutral and residual mild varus alignment, we searched PubMed, Embase, Cochrane Library and Web of Science databases from 1 January 1974 to 18 December 2020 to identify studies comparing clinical and functional outcomes as well as prosthesis survival in the presence of different alignments after total knee arthroplasty (TKA) for varus knees. The included studies were assessed by two researchers according to the Newcastle–Ottawa Scale (NOS). Postoperative neutral alignment (0° ± 3°) was compared to residual mild varus (3°–6°) and residual severe varus (>6°). Meta‐analysis was performed using Review Manager 5.3. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables. The fixed‐effect model and random‐effect model were used to meta‐analyze the data. Nine studies were included in the meta‐analysis with 1410 cases of postoperative neutral alignment, 564 of residual mild varus alignment and 175 of residual severe varus alignment following TKA, all of which were published after 2013. Three studies scored 7 points on the NOS, while the remaining studies scored 8 points, suggesting high quality. The pooled mean differences (MDs) of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were 1.07 [95% confidence interval (CI) −1.06 to 3.20; P = 0.32; I2 = 79%]. The meta‐analysis showed that neutral alignment and mild varus alignment were associated with similar the Oxford Knee Score (OKS), Knee Society Knee Score (KS‐KS), and Knee Society Function Score (KS‐FS), while neutral alignment was associated with lower Forgotten Joint Score (FJS) [mean difference −6.0, 95% confidence interval (CI) −9.37 to −2.64, P = 0.0005]. Neutral alignment was associated with higher KS‐KS than severe alignment (M 2.98, 95% CI 1.42 to 4.55, P = 0.0002; I2 = 0%) as well as higher KS‐FS (M 8.20, 95% CI 4.58 to 11.82, P < 0.00001; I2 = 0%). Neutral alignment was associated with similar rate of survival as mild varus alignment (95% CI 0.36 to 9.10; P = 0.48; I2 = 65%) or severe varus alignment (95% CI 0.94 to 37.90; P = 0.06; I2 = 61%). There was no statistical difference in others. Residual mild varus alignment after TKA may lead to similar or superior outcomes than neutral alignment in patients with preoperative varus knees, yet the available evidence appears to be insufficient to replace the current gold standard of neutral alignment. Severe varus alignment should be avoided. [ABSTRACT FROM AUTHOR]

Background and Objectives: Clinically, it is beneficial to determine the knee osteoarthritis (OA) subtype that responds well to conservative treatments. Therefore, this study aimed to determine the differences between varus and valgus arthritic knees in the response to conservative treatment. We hypothesized that valgus arthritic knees would respond better to conservative treatment than varus arthritic knees. Materials and Methods: Medical records of 834 patients who received knee OA treatment were retrospectively reviewed. Patients with Kellgren–Lawrence grades III and IV were divided into two groups according to knee alignment (varus arthritic knee, hip-knee-ankle angle [HKA] > 0° or valgus arthritic knee, HKA < 0°). The Kaplan–Meier curve with total knee arthroplasty (TKA) as an endpoint was used to compare the survival probability between varus and valgus arthritic knees at one, two, three, four, and five years after the first visit. A receiver operating characteristic (ROC) curve was used to compare the HKA thresholds for TKA between varus and valgus arthritic knees. Results: Valgus arthritic knees responded better to conservative treatment than varus arthritic knees. With TKA as an endpoint, the survival probabilities for varus and valgus arthritic knees were 24.2% and 61.4%, respectively, at the 5-year follow-up (p < 0.001). The thresholds of HKA for varus and valgus arthritic knees for TKA were 4.9° and −8.1°, respectively (varus: area under the ROC curve [AUC] = 0.704, 95% confidence interval [CI] 0.666–0.741, p < 0.001, sensitivity = 0.870, specificity = 0.524; valgus: AUC = 0.753, 95% CI 0.693–0.807, p < 0.001, sensitivity = 0.753, specificity = 0.786). Conclusions: Conservative treatment is more effective for valgus than for varus arthritic knees. This should be considered when explaining the prognosis of conservative treatment for knees with varus and valgus arthritis.

Abstract Background The inclination of the medial compartment of the proximal tibia (MCT) is assumed to be a critical factor for varus alignment in advanced knee osteoarthritis (OA). This study was aimed at investigating; (1) whether the inclination of MCT is aligned parallel to the ground under weight-bearing (WB) conditions; (2) whether this is associated with the change in alignment and the relative position between the bones; and (3) whether the tibia or femur mainly contributes to the changes. Methods We examined 102 knees (84 women, 18 men; mean 75 years). A three-dimensional (3D) assessment system was applied on biplanar whole lower extremity radiographies using 3D-to-2D image registration technique. The evaluation parameters were 1) MCT angle, 2) femorotibial angle (FTA), 3) medial-lateral femoral location to the tibia (M-L femoral location), 4) WB line passing point, and 5) tibial position to WB line (tibial position) and 6) femoral postion to WB line (femoral position). Each parameter was evaluated in non-WB and WB conditions, and the differences (Δ-parameters). Results MCT angle in the world coordinate system was larger than that in the tibial coordinate system (p

Introduction: The influence of patient demographic factors in predicting the success and failure of HTO remains largely unknown. Objectives: To determine factors associated with success or failure after high tibial osteotomy (HTO) for unicompartmental knee pain with varus deformity at a minimum of 2-year follow-up. Methods: A prospectively collected HTO outcomes registry was queried for patients undergoing HTO. Demographic, preoperative, intraoperative, radiographic, and postoperative data were collected. Patient factors were analyzed for their association with HTO failure, which was defined as conversion to uni- or total knee arthroplasty. Results: Seventy-five patients were identified (n = 58 males; n = 17 females) with a mean age of 37.3 ± 8.7 years at surgery and average follow-up of 5.5 ± 3.8 years. Forty-eight percent (n = 36) of patients underwent reoperation, 28% (n = 21) underwent hardware removal, and 17% (n = 13) converted to arthroplasty. Increased body mass index (BMI) (> 30 kg/m2) (P = .025) and age > 45 years (P = .020) were associated with HTO failure, while performance of concomitant procedures decreased failure probabilities (P = .008). Conclusion: s: High tibial osteotomy is an effective procedure for symptomatic patients with varus deformity, associated with a significant improvement in PROs, a moderate complication rate, and a high survival rate. Reoperation rates remain common, while failure rates requiring conversion to arthroplasty necessitate HTO be performed in appropriately selected patients. Performance of concomitant joint preservation procedures at the time of HTO was protective against HTO failure, while greater patient age and BMI were associated with HTO failures. Level of Evidence: Level 4, Case series

Introduction: The threshold values needed to achieve MCID and PASS following HTO with or without concomitant procedures are not well known. Objectives: To determine values and variables predictive for achieving the minimally clinically important difference (MCID) and patient acceptable symptom state (PASS) of patient-reported outcome (PRO) scores following high tibial osteotomy (HTO) with or without associated restoration procedures for the correction of varus deformity. Methods: A prospectively collected HTO outcomes registry was retrospectively reviewed for patients who underwent HTO between 2001 and 2018. Collected PROs included International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm scores. A distribution-based approach was used to calculate MCID, and an anchor-based approach was used for the calculation of PASS. Results: Fifty-five patients were identified (n = 43 males; n = 12 females) with a mean age of 37.9 ± 9.0 years at surgery and average follow-up of 3.3 ± 3.1 years. The MCID and PASS for IKDC were calculated as 12.5 and 40.23, respectively. MCID and PASS values for each of the KOOS subscales were as follows: symptoms: 9.9 and 71.43; pain: 11.3 and 72.22; daily living: 12.0 and 77.94; sports: 16.0 and 40; quality of life: 15.1 and 56.25, respectively. Conclusions: Based on calculated values for MCID and PASS following HTO using IKDC and KOOS subscales, higher preoperative PROs, prior medial meniscectomy, higher BMI, concomitant ACL reconstruction and worker's compensation status were associated with failure to achieve clinically significant outcomes. Prior ACL reconstruction was found to be predictive of MCID for KOOS-symptoms.

Background: Increased varus alignment of the lower extremity is known to be a poor prognostic factor for the surgical repair for a medial meniscus root tear (MMRT). However, given the concept of constitutional varus, which is present in a substantial portion of the normal population, the generally accepted surgical indication for MMRT concerning a varus alignment of 5° may be unnecessarily narrow. Purpose: To compare the surgical outcomes of arthroscopic transtibial pullout repair of MMRT according to the degree of varus alignment of the lower extremity. Study Design: Cohort study; Level of evidence, 3 Methods: Patients who underwent isolated arthroscopic transtibial pullout repair of MMRT between January 2010 and July 2017 at one institution and had a minimum follow-up of 2 years were included in this study. Patients were classified into 1 of 2 groups: the experimental group (n = 22) included patients with a preoperative hip-knee-ankle angle between 5° and 10° varus (mild to moderate varus alignment) and the control group (n = 51) included those with a preoperative hip-knee-ankle angle <5° varus (neutral alignment). Clinical scores and radiographic parameters were compared between the groups to assess surgical outcomes, which were statistically matched for potential confounders (age, body mass index, the severity of cartilage lesion) by use of the inverse probability of treatment weighting. A noninferiority trial was performed comparing the experimental and control groups in terms of subjective outcomes (International Knee Documentation Committee subjective and Lysholm scores) and objective outcomes (postoperative medial meniscal extrusion and the rate of osteoarthritis progression). Results: There were no statistically significant differences in surgical outcomes between the groups in subjective and objective aspects, which were consistent before and after inverse probability of treatment weighting. Apart from the clinical improvement observed in both groups, overall degenerative changes in the knee were found, although progression rates did not differ between the groups. In terms of the noninferiority trial, the overall surgical outcomes in the experimental group were not inferior to those in the control group. Conclusion: The short-term surgical outcomes of arthroscopic transtibial pullout repair for MMRT of patients with mild to moderate varus alignment were not inferior to but rather comparable with those with neutral alignment in terms of subjective and objective aspects. Therefore, it would be inappropriate to exclude patients with a diagnosis of MMRT from being indicated for the surgery simply because of mild to moderate varus alignment. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to examine the results of meniscal repair performed for symptomatic degenerative medial meniscal tears. Methods: Twenty-four knees in 24 patients with symptomatic degenerative medial meniscal tears (mostly complex horizontal tears) who underwent isolated arthroscopic repair combined with autologous fibrin clot implantation were included in this study. The patients were followed up for a minimum of 2 years. The overall clinical outcome was evaluated using the Lysholm score, while the activity level was graded on the Tegner Activity Scale. The assessment of healing status at the repair site was based on clinical signs/symptoms and follow-up MRI examination results. In addition, the effects of the patient's clinical and radiological factors on healing of the repaired menisci were analyzed. Results: The mean age of the study subjects was 47.0 ± 8.1 years with a mean follow-up period of 39.3 ± 11.6 months. The Lysholm score significantly improved after surgery (P < 0.01). During the follow-up period, meniscal repairs were deemed to have failed in 6 of the 24 knees (25%). In the analysis of factors influencing meniscal healing, varus deformity (% of mechanical axis < 30%) was identified in all knees in the repair failure group, and the presence of varus deformity was shown to be a significant risk factor correlated with repair failure, while other factors did not significantly influence the healing status. Conclusions: The short-term follow-up results showed that arthroscopic repair of degenerative medial meniscal tears combined with fibrin clot implantation attained clinical healing in 18 of 24 knees (75%) of patients, while 6 of the 24 knees (25%) of patients experienced clinical failure. The presence of varus deformity negatively affects the healing rate. In well-aligned knees, degenerative medial meniscal tears are successfully treated by isolated repair with fibrin clot implantation. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The current literature suggests that kinematic total knee arthroplasty (kTKA) may be associated with better outcome scores in patients with constitutional varus alignment. The underlying patellofemoral kinematic changes (patella tilting and patella tracking) and patellofemoral pressure distribution have not yet been described. The present study compared the effects of different tibial cuts, as used in kTKA, on patellofemoral knee kinematics and the pressure distribution, in addition to comparisons with the natural constitutional varus knee.Methods: Seven cadaveric knee joints with constitutional varus alignment were examined in the native state and after 0°, 3°, or 6° tibial cut cruciate-retaining (CR)-TKA using an established knee joint simulator. The effects on patella rotation/patella tilting, patellofemoral pressure, and patellofemoral length ratios (= patella tracking) were determined. In addition, the natural knee joint and different tibial cuts in CR-TKA were compared (Student's t test).Results: In the patellofemoral joint, 6° CR-TKA was associated with the greatest similarity with the natural constitutional varus knee. By contrast, knees subjected to 0° CR-TKA exhibited the largest deviations of patellar kinematics. The smallest difference compared with the natural knee joint concerning patella tilting was found for 6° CR-TKA (mean 0.4°, p < 0.001), and the largest difference was noted for 0° CR-TKA (mean 1.7°, p < 0.001). Concerning patellofemoral pressure, 6° CR-TKA resulted in outcomes most similar to the natural knee joint, featuring a mean difference of 3 MPa. The largest difference from the natural knee joint was identified for 0° CR-TKA, with an average difference of 8.1 MPa (p < 0.001; total mean 17.7 MPa). Meanwhile, 3° and 6° CR-TKA induced medialization of the patella, with the latter inducing the largest medialization value of 4.5 mm at 90° flexion.Conclusions: The improved outcome parameters in kTKA described in the literature could be attributable to the similar kinematics of the patellofemoral joint relative to the normal state. The current study confirmed the similar kinematics between the native constitutional varus knee joint and knee joints subjected to 3° or 6° CR-TKA (patellofemoral rotation/patella tilting and patella pressure). Conversely, there was pronounced medialization of the patella following 6° CR-TKA. Patella pressure and patella tilting are described in the literature as possible causes of anterior knee pain after TKA, whereas medialization of the patella, which is also influenced by other causes, might play a subordinate role.Level Of Evidence: V, Biomechanical study. [ABSTRACT FROM AUTHOR]

Purpose of Review: Coronal and sagittal malalignment in the setting of anterior cruciate ligament (ACL) deficiency alters knee biomechanics and is shown to increase stress and strain on the native ACL and on the ACL graft during reconstruction. The purpose of this review was to determine the role and indications of high tibial osteotomy to correct coronal and/or sagittal plane malalignment with ACL reconstruction. Recent Findings: Recent literature illustrates that an increase in varus malalignment and increased posterior tibial slope increases the biomechanical stress that is seen in a native or reconstructed ACL graft. It has been proposed to correct the sagittal and coronal malalignment by employing a high tibial osteotomy either prior to or at the time of ACL reconstruction to correct these deformities and to decrease the stress placed on the reconstructed ACL graft. Summary: The use of high tibial osteotomy for deformity correction creates a more stable knee for ACL reconstruction and has been shown to have good outcomes with regard to post-operative pain, stability, satisfaction scores, and function. [ABSTRACT FROM AUTHOR]

Purpose: Despite a debilitating effect on athletic performance and an incidence of up to 4% of all stress fractures, there have been only 31 documented cases of medial malleolus stress fractures (MMSF) to our knowledge in the literature. The largest series to date is presented in this study, of 16 professional soccer players undergoing uniform operative treatment. The authors attempt to justify their preferred treatment of MMSFs in the professional soccer player, with an emphasis on patient satisfaction, clinical and radiographic union, and return to high level sport. The authors aim to prove an association between lower limb varus alignment and the development of MMSFs.Method: Sixteen professional soccer players of mean age 23.6 years were analysed. A biomechanic assessment was performed. Preoperative CT+-MRI scan were performed to assess fracture lines and the presence of anteromedial tibial and/or talar spurs; which are the likely pathognomic lesion in the development of MMSFs. All patients underwent open reduction and internal fixation with three screws, as well as arthroscopic debridement of impringement spurs, and concentrated bone marrow aspirate into the fracture site. Patients completed the Ogilvie-Harris score, and all patients had CT scans at 3 months and until union.Results: All the patients in this cohort had causative bony spurs that were debrided at surgery. All of the cohort achieved clinical union. All patients were able to return to professional football; at the same level as prior to the injury. There was complete cohort follow up; and 81% of patients were graded as excellent and 19% as good by the Ogilvie-Harris score. We noted 50% of our cohort demonstrated varus malalignment, either genu varum or hindfoot varus.Conclusions: The authors conclude that open reduction and internal fixation of MMSFs with screws combined with arthroscopic spur debridement results in excellent clinical outcomes. It can be concluded that varus lower limb malalignment is a risk factor for MMSFs. Given the treatment controversy for these injuries, the results herein demonstrate that aggressive multimodal operative treatment produces excellent outcomes in high demand professional footballers. This study is the first to report a biomechanic association, which can alert the clinician to preventative measures; such as hindfoot orthoses.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: Varus alignment is known as one of the major causes of medial compartment osteoarthritis (OA). Medial meniscus extrusion also plays a critical role in the in the development of OA. However, studies on the exact relationship between alignment parameters and medial meniscus extrusion are limited. Therefore, this study aimed to investigate this relationship in patients with knee OA.Methods: Based on a retrospective analysis of the outpatient magnetic resonance imaging (MRI) database, 190 knees were identified to be examined using weight-bearing, whole-leg radiographs and MRIs within 3 months from the first consultation. Subsequently, various parameters of lower leg alignment were measured, which affected the knee varus in radiographs. Finally, a statistical analysis was performed to assess the relationships between the OA grade, distance of medial meniscus extrusion (MME), and alignment parameters; hip-knee-ankle angle (HKAA), percentage of mechanical axis (% MA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The subjects were divided according to the presence or absence of MME (Group A: MME distance below 3 mm, Group B: MME distance 3 mm and above) to assess the differences in each alignment parameter correlated with MME distance between the groups.Results: MME distance significantly increased with OA grade progression. HKAA, % MA, MPTA, and JLCA significantly correlated with medial meniscus extrusion distance (r = - 0.21, - 0.23, - 0.16, 0.3, respectively). Multiple regression analysis of each significant alignment combined with age, sex, and body mass index revealed that HKAA, % MA, MPTA, and JLCA were significant independent factors of MME distance (P = 0.008, 0.0026, 0.011, 0.0001, respectively). These significant findings were reinforced in group B. In contrast, the correlation between alignment parameters and medial meniscus extrusion distance was not significant in group A.Conclusion: Varus alignment factors are related to MME distance especially in extruded meniscus knees, as the OA grade progressed. Therefore, the coexistence of varus alignment and MME can be the risk factors for OA progression. As the low MPTA was an independent alignment factor for generating varus alignment, patients with osteoarthritis of the knee with both, low MPTA and MME could be the appropriate candidates for early intervention by high tibial osteotomy.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: To examine implant migration and articular behavior of primary total knee arthroplasty (TKA) at 10 years after index surgery and correlate to implant alignment.Methods: Thirty-five patients underwent a cemented posterior stabilized total knee arthroplasty with a surgical objective of neutral alignment and were enrolled in a long-term radiostereometric analysis (RSA) study. At 10 years after surgery, patients were analyzed for implant migration using RSA as well as radiographic assessment of articular behavior at four positions of knee flexion. Implant position and alignment was measured on full-length radiographs. Patient demographics and reported outcomes were also collected.Results: No difference between patient demographics or patient-reported outcomes were found. When categorized into neutral and varus groupings, no difference in migration was present. If alignment was considered as a continuous variable, there was no correlation between overall leg alignment and migration, however, migration increased with an increasing varus tibial alignment. Although contact location did not differ between neutral and varus groups through a range of motion, condylar liftoff was much more common in the varus group, of which all were lateral liftoff.Conclusions: Increased tibial varus results in increased implant migration. Overall varus limb alignment is correlated with isolated lateral compartment liftoff, and liftoff occurs more commonly than in neutral aligned knees. The increased migration and liftoff raise concerns about the longevity of malaligned total knee replacements. If a goal of overall varus limb alignment is desired for TKA, the tibia should remain neutral.Level Of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to compare the femoral and popliteal arteries pathway in varus and valgus- aligned lower limbs. Methods: A retrospective CT angiography (CTA) study from October to December 2021 was conducted. Distance of the femoral and popliteal artery to specific bony landmarks in thigh and knee was measured. Results: Eighty limbs including 40 varus and 40 valgus lower limbs were assessed. No significant difference between varus/valgus groups in terms of distances was noted. Conclusion: Our study compared pathway of PA and FA artery in varus and valgus knees using CTA images; and no significant differences was seen between the two groups of varus and valus. [ABSTRACT FROM AUTHOR]

Purpose: Abnormal knee motion under various conditions has been described after total knee arthroplasty (TKA). However, differences in kinematics and kinetics of knees with varus femoral versus varus tibial alignment have not been evaluated. It was hypothesized that varus femoral and tibial alignments have the same impact on knee motion.Methods: A musculoskeletal computer simulation was used. Femoral and tibial alignment in the coronal plane was each varied from neutral to 5° of varus in 1° increments. Lift-off, defined as an intercomponent distance of >2 mm, and tibiofemoral contact forces were evaluated during gait up to 60° of knee flexion. Knee kinematics and contact stresses were also examined during squat, with up to 130° of knee flexion.Results: During gait, lift-off occurred readily with more than 3° of varus tibial alignment and slight lateral joint laxity. In contrast, lift-off did not occur with varus femoral or tibial alignment of up to 5° during squat. Peak medial contact forces with varus femoral alignment were approximately twice those observed with varus tibial alignment. The lowest points of the femoral condyles moved internally with varus femoral alignment, contrary to the kinematics with neutral or varus tibial alignment. On the other hand, there was femoral medial sliding and edge loading against the tibia in mid-flexion with varus tibial alignment.Conclusion: Varus femoral alignment affects the non-physiological rotational movement of the tibiofemoral joint, whereas varus tibial alignment causes medial-lateral instability during mid-flexion. Varus femoral and tibial alignments might lead to post-TKA discomfort and unreliability. [ABSTRACT FROM AUTHOR]

Background: Dynamic and static varus alignment, both, have been reported as risk factors associated with structural progression of knee osteoarthritis. However the association of none of the static and dynamic alignment with structural, clinical, and functional progression associated with knee osteoarthritis has not been assessed yet in a longitudinal study.Methods: Forty-seven women with early and established medial knee osteoarthritis were evaluated. Static and dynamic alignment as well as MRI detected structural features, clinical, and functional characteristics of patients were assessed at baseline and at 2 years follow-up. Associations between baseline static and dynamic alignment with structural, functional, and clinical characteristics at the time of entry, as well as the changes over 2 years were evaluated.Findings: Both static and dynamic varus alignment at baseline were significantly associated with osteoarthritis related tibio-femoral joint structural abnormalities detected on MRI, at the time of entry. Only the magnitude of varus thrust at baseline was predictive of the changes in the presence of meniscal maceration over two years. None of the static or dynamic measures of knee joint alignment were associated with clinical characteristics associated with medial knee osteoarthritis.Interpretation: The key finding of this study is that both frontal plane dynamic and static alignment, are associated with structural abnormalities in patients with medial knee osteoarthritis. [ABSTRACT FROM AUTHOR]

Postural bowleg is a subclinical entity with both aesthetic and functional outcomes and appears to be common in East Asian countries. Internal rotation of the hip joint is associated with varus alignment at the knee joint of the bowleg. Strengthening exercise for the hip external rotator muscles seems to be effective in improving varus alignment of bowleg, but no standardized exercise program exists. A standardized active resistance strengthening exercise for hip external rotator muscles could improve varus alignment of the lower limb in bowlegged Korean women. In this article, a case series study was conducted to observe changes following a standardized 3-month program using equipment designed for strengthening of the hip external rotator muscles. Photogrammetric and radiographic data were used to compare the gap between knees and tibiofemoral (TF) angles before and after the exercise program. As a result, on average, the knee gap decreased by 1.6 cm. The TF angle decreased by 1.5°. Regression analysis revealed a statistically significant association between changes in knee gap and TF angle. The standardized 3-month active resistance strengthening exercise program of hip external rotator muscles was effective in improving postural deviation and cosmetic outcomes in bowlegged Korean women. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors . [ABSTRACT FROM AUTHOR]

Purpose: Toe-in (TI) and toe-in with wider step width (TIW) gait modifications have successfully reduced the internal peak knee adduction moment (KAM) during level walking and stair ascent tasks, respectively, for healthy and knee osteoarthritis populations. However, the concurrent effects of these modifications have not previously been combined to reduce both the first and the second peak KAM during stair ascent or tested among the different knee alignment groups. Therefore, the purpose of this study was to examine effects of TI and TIW gait modifications on knee biomechanics during stair ascent in individuals with varus, neutral, and valgus knee alignments. Methods: Thirty-eight healthy individuals (age 18-30 yr) with varus, neutral, and valgus knee alignments confirmed using radiographs, performed stair ascent in normal, TI, and TIW gait conditions. A3 x 3 (group x condition) mixed model repeated-measures ANOVA compared alignment groups across the stair ascent gait conditions (P < 0.05). Results: The TI and the TIW reduced the first peak KAM and KAM impulses compared with normal stair ascent. The TIW also reduced the second peak KAM compared with normal gait and reduced KAM impulses compared with TI. The varus group had increased first peak KAM compared with neutral and valgus groups. The TI and the TIW also reduced peak knee flexion moments compared with normal gait. The TIW also reduced peak external rotation moments compared with normal gait. Conclusions: The TIW gait modification seems to be successful in reducing knee joint loading in all three planes during stair ascent, regardless of knee alignment. The success of TIW in varus knee alignments may have important implications for people with medial knee osteoarthritis, or those susceptible to knee osteoarthritis. [ABSTRACT FROM AUTHOR]

ABSTRACT This study quantified the contributions by muscles, gravity, and inertia to the tibiofemoral compartment forces in the symptomatic (SYM) and asymptomatic (ASYM) limbs of varus mal-aligned medial knee osteoarthritis (OA) patients, and compared the results with healthy controls (CON). Muscle forces and tibiofemoral compartment loads were calculated using gait data from 39 OA patients and 15 controls aged 49 ± 7 years. Patients exhibited lower knee flexion angle, higher hip abduction, and knee adduction angles, lower internal knee flexion torque but higher external knee adduction moment. Muscle forces were highest in CON except hamstrings, which was highest in SYM. ASYM muscle forces were lowest for biceps femoris short head and gastrocnemius but otherwise intermediate between SYM and CON. In all subjects, vasti, hamstrings, gastrocnemius, soleus, gluteus medius, gluteus maximus, and gravity were the largest contributors to medial compartment force (MCF). Inertial contributions were negligible. Highest MCF was found in SYM throughout stance. Small increases in contributions from hamstrings, gluteus maximus, gastrocnemius, and gravity at the first peak; soleus and rectus femoris at the second peak; and soleus, gluteus maximus, gluteus medius, and gravity during mid-stance summed to produce significantly higher total MCF. Compared to CON, the ASYM limb exhibited similar peak MCF but higher mid-stance MCF. In patients, diminished non-knee-spanning muscle forces did not produce correspondingly diminished MCF contributions due to the influence of mal-alignment. Our findings emphasize consideration of muscle function, lower-limb alignment, and mid-stance loads in developing interventions for OA, and inclusion of the asymptomatic limb in clinical assessments. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:321-330, 2017. [ABSTRACT FROM AUTHOR]

Background: Two-dimensional (2D) coronal joint line orientation on radiography under weight-bearing conditions has been widely used in evaluating knee osteoarthritis (OA). However, the effects of tibial rotation remain unknown. The present study aimed to newly define three-dimensional (3D) joint surface orientation relative to the floor as an unchangeable 3D angle unaffected by tibial rotation using upright computed tomography (CT), and to investigate correlations between 3D and 2D parameters in knee OA., Methods: Sixty-six knees in 38 patients with varus knee OA underwent standing hip-to-ankle digital radiography and upright CT. The 2D parameters measured on radiographs included femorotibial angle (FTA), tibial joint line angle (TJLA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The 3D inner product angle between vectors of the tibial joint surface and the floor from CT was defined as the 3D joint surface-floor angle., Results: Mean 3D joint surface-floor angle was 6.0 ± 3.6°. No correlation was identified between 3D joint surface-floor angle and 2D joint line parameters, even though FTA correlated substantially with 2D joint line parameters. No significant differences in 3D joint surface-floor angle were identified among Coronal Plane Alignment of the Knee (CPAK) types., Conclusions: The 3D joint surface orientation did not correlate with 2D coronal joint line orientation and was unaffected by CPAK classification types. This finding suggests that current 2D evaluations should be reconsidered for a better understanding of true knee joint line orientation., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Masahiro Jinzaki has received a grant from Canon Medical Systems. However, Canon Medical Systems was not involved in the design and conduct of the study, in the collection, analysis, and interpretation of the data, or in the preparation, review, and approval of the manuscript. The remaining authors have no conflicts of interest to declare.]., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Restoration of neutral mechanical alignment is one of the prerequisites for long-term TKA survival. This study aimed to investigate the effect of deviations from neutral alignment on bone and implant stress and on ligament strain. Using a previously validated finite element model, a neutrally aligned TKA model was compared to 3 different varus and valgus configurations induced by tibial or by femoral component only and by both component simultaneously. Each model underwent a 2500 N vertical load simulating the peak walking force. Varus and valgus alignment increased polyethylene and bone stress, and altered ligament strains, as compared to the neutral aligned model. Changes in alignment of the tibial component were always associated with more detrimental effects compared to the one of the femoral component. [ABSTRACT FROM AUTHOR]

Purpose: To prospectively investigate whether preoperative functional flexion axis in patients with osteoarthritis- and varus-alignment changes after total knee arthroplasty and whether a correlation exists both between preoperative functional flexion axis and native limb deformity. Methods: A navigated total knee arthroplasty was performed in 108 patients using a specific software to acquire passive joint kinematics before and after implant positioning. The knee was cycled through three passive range of motions, from 0° to 120°. Functional flexion axis was computed using the mean helical axis algorithm. The angle between the functional flexion axis and the surgical transepicondylar axis was determined on frontal ( α) and axial ( α) plane. The pre- and postoperative hip-knee-ankle angle, related to femur mechanical axis, was determined. Results: Postoperative functional flexion axis was different from preoperative only on frontal plane, while no differences were found on axial plane. No correlation was found between preoperative α and native limb deformity, while a poor correlation was found in frontal plane, between α and preoperative hip-knee-ankle angle. Conclusions: Total knee arthroplasty affects functional flexion axis only on frontal plane while has no effect on axial plane. Preoperative functional flexion axis is in a more varus position respect to the transepicondylar axis both in pre- and postoperative conditions. Moreover, the position of the functional axis on frontal plane in preoperative conditions is dependent on native limb alignment, while on axial plane is not dependent on the amount of preoperative varus deformity. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: Restoration of correct alignment is one of the main objectives of total knee arthroplasty (TKA). However, the influence of residual malalignment on clinical and functional outcomes is currently uncertain. This study was therefore undertaken to ascertain its influence in patients undergoing TKA for varus osteoarthritis of the knee. Methods: A cohort of 132 consecutive patients (143 knees) with pre-operative varus alignment was evaluated with a mean follow-up period of 7.2 years. Based upon the post-operative alignment, patients were stratified into three groups: neutral, mild varus, and severe varus. These groups were compared with respect to clinical and functional outcomes. Results: All patients had post-operative improvements in Knee Society Score (KSS). Knees that were left in mild varus scored significantly better for the KSS and the Western Ontario and McMaster Universities Arthritis Index, compared with knees that were corrected to neutral and knees that were left in severe varus exceeding 6°. No revisions occurred in any of the groups at midterm follow-up. Conclusion: The results of this study contradict the conventional assumption that correction to neutral mechanical alignment leads to the best outcome following TKA. Patients with pre-operative varus had better clinical and functional outcome scores if the alignment was left in mild varus, as compared with patients with an alignment correction to neutral. Level of evidence: Therapeutic study, Level III. [ABSTRACT FROM AUTHOR]

Aims: A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting., Methods: This retrospective study included 255 patients who underwent 305 OUKAs with cementless tibial components. There were 52 males and 203 females. Their mean age was 73.1 years (47 to 91), and the mean follow-up was 1.9 years (1.0 to 2.0). In 217 knees in 187 patients in the conventional group, tibial cuts were made orthogonally to the tibial axis. The varus group included 88 knees in 68 patients, and tibial cuts were made slightly varus using a new osteotomy guide. Anterior and posterior KCDs and the origins of fracture lines were assessed using 3D CT scans one week postoperatively. The KCDs and rate of fracture were compared between the two groups., Results: Medial tibial fractures occurred after surgery in 15 patients (15 OUKAs) in the conventional group, but only one patient (one OUKA) had a tibial fracture after surgery in the varus group. This difference was significant (6.9% vs 1.1%; p = 0.029). The mean posterior KCD was significantly shorter in the conventional group (5.0 mm (SD 1.7)) than in the varus group (6.1 mm (SD 2.1); p = 0.002)., Conclusion: In OUKA, the distance between the keel and posterior tibial cortex was longer in our patients with slight varus alignment of the tibial component, which seems to decrease the risk of postoperative tibial fracture.Cite this article: Bone Joint J  2022;104-B(10):1118-1125.

A retrospective review was conducted to evaluate the mid-term results (8.5 years follow-up) of the Versys ET stem (Zimmer, Warsaw, Indiana, USA). From 1995 to 2000, 225 total hip arthroplasties (THA) were performed using this device. All patients were evaluated clinically by the Harris Hip Score, and radiographically. The Hip Score increased from 54 preoperatively to 97 points postoperatively. The stem displayed a varus alignment between 5° and 10° in 17 cases without any clinical consequences (HHS 96.8). We recorded one case of septic loosening and one case of aseptic loosening. The stability of the stem was radiographically evaluated according to Engh’s criteria, confirming bone ongrowth in all other cases. [ABSTRACT FROM AUTHOR]