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Chondrosarcomas, malignant cartilaginous neoplasms, are capable of transitioning to highly aggressive, metastatic, and treatment-refractory states, resulting in significant patient mortality. Here, we aim to uncover the transcriptional program directing such tumor progression in chondrosarcomas. We conduct weighted correlation network analysis to extract a characteristic gene module underlying chondrosarcoma malignancy. Hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is identified as an upstream regulator that governs the malignancy gene module. HIF-2α is upregulated in high-grade chondrosarcoma biopsies and EPAS1 gene amplification is associated with poor prognosis in chondrosarcoma patients. Using tumor xenograft mouse models, we demonstrate that HIF-2α confers chondrosarcomas the capacities required for tumor growth, local invasion, and metastasis. Meanwhile, pharmacological inhibition of HIF-2α, in conjunction with the chemotherapy agents, synergistically enhances chondrosarcoma cell apoptosis and abolishes malignant signatures of chondrosarcoma in mice. We expect that our insights into the pathogenesis of chondrosarcoma will provide guidelines for the development of molecular targeted therapeutics for chondrosarcoma., Chondrosarcomas are frequently aggressive, understanding the transcriptional changes associated with progression may help in developing new treatments. Here, the authors show that HIF-2α is increased in expression on progression and pharmacological inhibition of the protein together with chemotherapy is a useful strategy for controlling tumour growth in mice.

Introduction: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA). Methodology: This cross-sectional study included 122 patients who underwent total knee arthroplasty. Central and knee dual-energy X-ray absorptiometry was performed preoperatively. BMD at 6 regions of interest (ROIs) around the knee joint were measured, and their correlations with central BMD were determined using Spearman's correlation analysis. Lower limb alignment, severity of OA, body mass index (BMI), preoperative functional and pain scores were assessed to elucidate the factors associated with knee BMD using linear regression analysis. Results: Around the knee joint, BMD was the lowest at the distal femoral metaphysis and lateral tibial condyle. Knee BMD was significantly correlated with central BMD. However, the correlation coefficients varied by the ROI. Additionally, multivariate analysis revealed different associations with respect to the regions around the knee joint. Varus alignment of the lower limb was associated with increased BMD of the medial condyles and decreased BMD of lateral condyles. High grade OA was a protective factor; it was associated with increased BMD at the lateral condyles of the femur and tibia. Higher BMI was an independent protective factor in all ROIs around the knee joint except the lateral femoral condyles. Lower functional level was not associated with decreased BMD, whereas a higher pain score was significantly associated with lower BMD at the proximal tibial metaphysis. Conclusions: Knee BMD was significantly correlated with central BMD. However, the correlations varied with the regions around the knee joint probably due to their independent association with the alignment of the lower limb, severity of OA, BMI, and preoperative pain level.

BACKGROUND Tranexamic acid (TXA) is typically discontinued on the day of total knee arthroplasty (TKA). However, bleeding may persist for several days. We sought to determine whether sequential administration of intravenous (IV) and oral TXA could reduce hemoglobin (Hb) drop more than IV TXA alone. We also wanted to determine whether the use of additional oral TXA increased the rate of complications of deep vein thrombosis (DVT) or symptomatic pulmonary embolism (PE). METHODS This prospective, randomized controlled trial included 141 patients. We compared the Hb drop, estimated blood loss (EBL), and transfusion rate of patients receiving IV TXA alone (group IV, n = 48) to those of patients who received IV TXA followed by oral TXA for 2 days (group 2D, n = 46) or 5 days (group 5D, n = 47). IV TXA was administered 10 minutes prior to the tourniquet release and 3 hours after the first IV TXA administration. Computed tomography (CT) was performed on postoperative day 6 to identify radiographic evidence of DVT. We also assessed the prevalence of symptomatic DVT and PE. RESULTS There were no differences in maximal Hb drop, Hb drops measured at each time point, EBL, or transfusion rate among the 3 groups. The mean maximal Hb drop was 3.5 g/dL in group IV, 3.2 g/dL in group 2D, and 3.4 g/dL in group 5D. The mean EBL was 999.9 mL in group IV, 886.4 mL in group 2D, and 972.5 mL in group 5D. One patient in each group required a transfusion. There were no differences in the prevalence of radiographic evidence of DVT or symptomatic DVT. Symptomatic DVT occurred in 3 patients in group IV and 2 patients in group 5D. One patient in group IV developed a symptomatic PE. CONCLUSIONS Although there was no increase in the complication rate, the sequential administration of oral TXA for up to 5 days after IV TXA did not decrease Hb drop. Therefore, our findings suggest that sequential use of oral and IV TXA is not recommended. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Background: The anterolateral ligament of the knee (ALL) is a component of the lateral complex that stabilizes the structure against rotational force and may be associated with the outcome of anterior cruciate ligament (ACL) reconstruction (ACLR). Purpose: To (1) find whether the visibility of the structure of the ALL is different in primary and revision ACLR groups, (2) determine whether the abnormal findings of the ALL structure on magnetic resonance imaging (MRI) scans are associated with type of trauma in ACL injury and mode of graft failure, and (3) determine whether there are differences in knee functional scores between patients with or without abnormal findings of the ALL structure on MRI scans in primary and revision ACLR groups. Study Design: Cohort study; Level of evidence, 3. Methods: This retrospective study included 40 patients who underwent primary ACLR and 39 patients who underwent revision ACLR. Conventional MRI (1.5-T) scans taken before primary or revision ACLR were obtained and analyzed for visibility of the ALL, frequency and degree of injury of the ALL, and ALL signal anomalies. We also evaluated 1-year postoperative functional knee scores using the subjective International Knee Documentation Committee and Lysholm scores. Results: Visibility of the ALL was better in the primary ACLR group than the revision ACLR group (38% vs 14%; P = .041). The primary ACLR group showed a lower degree of injury across the femoral, meniscal, and tibial attachment sites than did the revision ACLR group (30% vs 13%, 41% vs 8%, and 62% vs 26%, respectively). Relative signal anomaly of the ALL was more frequent in the case of contact versus noncontact trauma of the ACL (85% vs 15%; P = .035), while absolute signal anomaly was equally observed between cases of contact and noncontact trauma in the primary ACLR group (50% vs 50%). No association was observed between ALL signal anomalies and 1-year postoperative functional knee scores. Conclusion: The revision ACLR group offered less visibility and showed a tendency for more frequent, higher degree of injury to the structure of the ALL. Regardless of observational differences between the 2 groups, no definite relevance was observed between the image and the functional outcome. For the assessment of the ALL, routinely performed conventional MRI alone is insufficient to make a clinical decision.

Studies regarding the best strategy to determine appropriate femoral component rotation during bilateral total knee arthroplasty (TKA) in wind swept deformities (WSD) are very limited. The purpose of this study was (1) to evaluate whether femoral rotational profiles differ between varus and valgus osteoarthritic knees in WSD and (2) to analyze the correlation between femoral rotational profiles and coronal radiologic parameters. A total of 40 patients who were diagnosed with bilateral knee osteoarthritis with WSD between January 2010 and December 2020 at a single institution were retrospectively reviewed. On axial computed tomography scans, femoral rotational profile parameters such as the clinical transepicondylar axis (cTEA) and anterior–posterior (AP) axis were compared between valgus and varus osteoarthritic knees. In standing full-limb AP radiographs, coronal radiographic parameters including hip–knee–ankle angle (HKA), valgus correction angle (VCA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) were measured in both knees. The correlation between the varus-valgus cTEA difference, and differences in coronal radiologic parameters was analyzed. In valgus osteoarthritic knees, cTEA was significantly increased compared to varus osteoarthritic knees by 1.5° (valgus: 7.65° ± 1.82°, varus: 6.15° ± 1.58°, p

Background: We aimed to determine whether temporal values of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) after total knee arthroplasty (TKA) differ between patients with and without elevated preoperative CRP. We hypothesized that temporal pattern of CRP and ESR change would differ between the two groups. Materials and Methods: This retrospective study included 30 TKAs with a diagnosis of osteoarthritis with elevated preoperative CRP (>1 mg/dl) without clinical signs and symptoms of infection before surgery (elevated CRP group). Patients without elevated preoperative CRP were matched in a 1:10 fashion according to age, sex, number of comorbidities and whether TKA was unilateral or bilateral (nonelevated CRP group). The temporal values of CRP and ESR after TKA were compared between the two groups until 2 months after surgery. Results: The mean peak values of CRP and ESR after surgery were similar between the two groups in both unilateral and bilateral TKAs. In the unilateral TKA, mean values of CRP and ESR and the proportions of the knees with normal CRP and ESR at 2 months after surgery were similar in the two groups. However, in the bilateral TKA, mean values of CRP and ESR were higher and the proportions of the knees with normal CRP and ESR at 2 months after surgery were lower in the elevated CRP group compared to the nonelevated CRP group. Conclusions: When performing TKA in patients with elevated preoperative CRP, the fact that the levels of CRP and ESR may not be normalized until 2 months after surgery should be considered during followup.

The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) remains controversial, even though SONK involves only one compartment of the knee joint. We aimed to compare the survival rate and clinical outcomes of UKA in SONK and medial compartment osteoarthritis (MOA) via a meta-analysis of previous studies. MEDLINE, Embase, and Cochrane Library were searched up to January 2018 with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: (1) medial UKA as the primary procedure, (2) reporting implant survival or clinical outcomes of osteonecrosis and osteoarthritis, and (3) follow-up period > 1 year. Quality assessment was performed using the risk of bias assessment tool for non-randomized studies. A random-effects model was used to estimate the pooled relative risk (RR) and standardized mean difference. The incidence of UKA revision for any reason was significantly higher in SONK than in MOA group (pooled RR = 1.83, p = 0.009). However, the risk of revision due to aseptic loosening was not significantly different between the groups. Moreover, when stratified by the study quality, high-quality studies showed similar risk of overall revision in SONK and MOA (p = 0.71). Subgroup analysis revealed no significant difference in failure between SONK and MOA after cemented mobile and fixed bearing UKA. Results of uncemented UKA were reported only in one study, which showed higher failure of SONK compared to MOA. Clinical outcomes after UKA were similar between SONK and MOA (p = 0.66). Cemented UKA has similar survival and clinical outcomes in SONK and MOA. Prospective studies designed specifically to compare the UKA outcomes in SONK and MOA are necessary.

Background: Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established. Purpose: To determine the degree of gap healing achieved without bone grafting, the factors associated with gap healing, and whether additional gap healing would be obtained after plate removal. Study Design: Cohort study; Level of evidence, 3. Methods: This retrospective study included 73 patients who underwent OWHTO without bone grafting between 2015 and 2018. Patients in the study were divided into 2 groups based on the correction angle: small correction group (Results: Although both groups achieved acceptable gap healing regardless of the correction angle, the SC group showed higher and earlier gap healing than did the LC group (gap healing rate 81.4% in the SC group vs 41.7% in the LC group at 3 months postoperatively). The GVR was 8.6% in the SC group and 15.3% in the LC group at 12 months after surgery ( P = .005). Both the amount of time that elapsed after surgery and the correction angle were associated with gap healing ( P < .05). Additional gap healing was observed after plate removal, as the GVR decreased 2.7% more in the patients with plate removal than in patients who did not have plate removal ( P = .012). Conclusion: All patients achieved acceptable gap healing without bone graft. The degree of gap healing was higher in the SC group and increased over time. Gap healing was promoted after plate removal. Considering the results of this study, a bone graft is not necessary in routine OWHTO in terms of gap healing.

The degree of cartilage degeneration assessed intraoperatively may not be sufficient as a criterion for patellar resurfacing in total knee arthroplasty (TKA). However, single-photon emission tomography/computed tomography (SPECT/CT) is useful for detecting osteoarthritic involvement deeper in the subchondral bone. The purpose of the study was to determine whether SPECT/CT reflected the cartilage lesion underneath the patella in patients with end-stage osteoarthritis (OA) and whether clinical outcomes after TKA without patellar resurfacing differed according to the severity of patellofemoral (PF) OA determined by visual assessment and SPECT/CT findings. This study included 206 knees which underwent TKA. The degree of cartilage degeneration was graded intraoperatively according to the International Cartilage Repair Society grading system. Subjects were classified into low and high uptake groups according to the degree of bone tracer uptake (BTU) on SPECT/CT in the PF joint. The Feller's patella score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed preoperatively and postoperative 1 and 2 years. The increased BTU in the PF joint was associated with more severe degenerative cartilage changes underneath the patella (p

Introduction Implant material is a more important factor for periprosthetic tibial bone resorption than implant design after total knee arthroplasty (TKA). The virtual perturbation study was planned to perform using single case of proximal tibia model. We determined whether the implant materials’ stiffness affects the degree of periprosthetic tibial bone resorption, and whether the effect of material change with the same implant design differed according to the proximal tibial plateau areas. Materials and methods This three-dimensional finite element analysis included two cobalt-chromium (CoCr) and two titanium (Ti) tibial implants with different designs. They were implanted into the proximal tibial model reconstructed using extracted images from computed tomography. The degree of bone resorption or formation was measured using the strain energy density after applying axial load. The same analysis was performed after exchanging the materials while maintaining the design of each implant. Results The degree of periprosthetic tibial bone resorption was not determined by the type of implant materials alone. When the implant materials were changed from Ti to CoCr, the bone resorption in the medial compartment increased and vice versa. The effect of material composition’s change on anterior and posterior areas varied accordingly. Conclusions Although the degree of bone resorption was associated with implant materials, it differed depending on the design of each implant. The effect on the degree of bone resorption according to the materials after TKA should be evaluated while concomitantly considering design.

Summary Cellular senescence is a complex stress response implicated in aging. Autophagy can suppress senescence but is counterintuitively necessary for full senescence. Although its anti-senescence role is well described, to what extent autophagy contributes to senescence establishment and the underlying mechanisms is poorly understood. Here, we show that selective autophagy of multiple regulatory components coordinates the homeostatic state of senescence. We combined a proteomic analysis of autophagy components with protein stability profiling, identifying autophagy substrate proteins involved in several senescence-related processes. Selective autophagy of KEAP1 promoted redox homeostasis during senescence. Furthermore, selective autophagy limited translational machinery components to ameliorate senescence-associated proteotoxic stress. Lastly, selective autophagy of TNIP1 enhanced senescence-associated inflammation. These selective autophagy networks appear to operate in vivo senescence during human osteoarthritis. Our data highlight a caretaker role of autophagy in the stress support network of senescence through regulated protein stability and unravel the intertwined relationship between two important age-related processes.

Background We determined whether postoperative intravenous (IV) iron supplementation could reduce transfusion rate in patients undergoing staged bilateral total knee arthroplasty (TKA). Furthermore, we examined whether hemoglobin (Hb) levels and iron profile differed between patients with and without postoperative IV iron supplementation. Methods This retrospective, comparative cohort study included 126 patients who underwent primary staged bilateral TKA during a single hospitalization. The second TKA was performed at a week’s interval. Group iron (n = 65) received IV iron immediately after each surgery, while patients in group no-iron (n = 61) received no iron after surgery. Transfusion rate, change in Hb levels, and iron profile including serum iron, ferritin, total iron binding capacity, and transferrin saturation were evaluated preoperatively; on postoperative days 1, 2, and 4 after the first TKA; and postoperative days 1, 2, 4, and 7, 6 weeks, and 3 months after the second TKA. Results There were no significant differences in Hb levels and transfusion rate following staged bilateral TKA between patients with and without postoperative IV iron supplementation although serum iron profiles were improved in patients with IV iron supplementation. Conclusion Postoperative IV iron supplementation immediately after acute blood loss caused by TKA was not effective in improving the transfusion rate. Therefore, surgeons should use protocols other than postoperative IV iron supplementation for reducing the transfusion rate in patients undergoing staged bilateral TKA in a single hospitalization. Level of Evidence III.

IntroductionAt present, information about clinical efficacy and adverse events of controlled release (CR) form of pelubiprofen, a prodrug of 2-arylopropionic acid with relatively selective effects on cyclooxygenase-2 activity, remains scarce. In this study, we sought to determine non-inferiority of pelubiprofen CR 90 mg/day compared to aceclofenac 200 mg/day regarding clinical efficacy and adverse events after a 4-week course of medication in the patients with symptomatic knee osteoarthritis.Materials and methodsA total of 191 patients were randomly assigned to take either pelubiprofen CR 90 mg (n = 95) or aceclofenac 200 mg (n = 96). The primary outcome variable was non-inferiority of pain reduction between baseline and week 4 when assessed using a 100 mm pain visual analogue scale (VAS). Pelubiprofen was considered non-inferior to aceclofenac if the upper limit of the one-sided 97.5% confidence interval for the difference in terms of pain VAS was above 15 mm (the average change of pain VAS in the pelubiprofen group-pain VAS reduction in the aceclofenac group). Secondary outcome variables were the changes in 100 mm pain VAS at week 2 versus baseline, K-Western Ontario, and McMaster University Arthritis Index (K-WOMAC) changes at weeks 2 and 4 as compared to baseline, patient global assessment at weeks 2 and 4. The frequency and amount of rescue medicine usage at weeks 2 and 4 were also evaluated as the secondary outcome variable. For safety analysis, adverse events, clinical laboratory tests, vital signs, and physical examinations were assessed and conducted at each follow-up visit.ResultsAt week 4, the pain VAS values were significantly reduced in both groups receiving either pelubiprofen CR 90 mg or aceclofenac 200 mg as compared to the baseline. However, the pelubiprofen group and the aceclofenac group respectively showed the pain VAS changes of -22 and -21.9 in the pre-protocol set and -20.8 and -21.7 in the full analysis set, confirming non-inferiority. The pelubiprofen CR 90 mg showed a reduced incidence of adverse events compared to the aceclofenac 200 mg (p = 0.005).ConclusionsPelubiprofen CR 90 mg is as effective as aceclofenac 200 mg with reduced adverse events for the treatment of symptomatic knee osteoarthritis.

We aimed at determining whether the coronal alignment of lower extremity was related to rotational geometry of distal femur, femoral anteversion, and tibial torsion in patients with knee osteoarthritis.A total of 422 lower extremities were divided into 3 groups according to the coronal alignment: valgus (n = 31), neutral (n = 78), and varus group (n = 313). Condylar twisting angle was measured to determine rotational geometry of distal femur as the angle between the clinical transepicondylar axis and the posterior condylar line. Femoral anteversion was assessed using the angle between a line intersecting the femoral neck and the posterior condylar line (pFeAV) and the angle between the same line and transepicondylar axis that is not affected by posterior condylar variations (tFeAV). Tibial torsion was evaluated by measuring the angle between the posterior condyles of the proximal tibia and the transmalleolar axis.As the coronal alignment changed from varus to valgus, the condylar twisting angle increased (r = 0.253, P.001; 6.6° in varus, 7.4° in neutral, and 10.2° in valgus group). Although the pFeAV also increased (r = 0.145, P = .003), the tFeAV did not change significantly (P = .218). Mean tFeAV was 4.3° in varus, 4.7° in neutral, and 6.5° in valgus group. In contrast, as the coronal alignment changed from varus to valgus, the external tibial torsion increased (r = 0.374, P.001; 22.6° in varus, 26.3° in neutral, and 32.6° in valgus group).The change patterns of the rotational profiles of the lower extremity according to the coronal alignment should be considered in order to obtain satisfactory rotational alignment after TKA.

Background This study aimed to determine the prevalence of excessive lateral pressure syndrome (ELPS) in potential candidates for high tibial osteotomy (HTO) using single-photon emission computed tomography–computed tomography (SPECT–CT). We also sought to identify risk factors related to the presence of ELPS. Methods This retrospective study included 150 patients (216 knees) who were candidates for HTO from an initial screening of 3579 patients (7158 knees). There were 183 female and 33 male knees with a mean age of 58 years. The presence of ELPS was defined as a grade 3 uptake on the SPECT–CT at the lateral PF joint. To determine the risk factors related to the ELPS, multivariate regression analysis was performed with independent demographic and radiographic variables. Results Increased uptake on the lateral side of the PF joints was detected in 120 knees (56% of total subjects). Of these, 34 (16%) knees presented with a grade 3 uptake, which indicated the presence of ELPS. No single risk factor had significant associations with the presence of ELPS. Conclusions A considerable number of the knees that were candidates for HTO had ELPS. Nonetheless, we did not find any risk factor related to the presence of ELPS. These results suggest that surgeons should be cautious when diagnosing concomitant ELPS despite acceptable radiographic findings from patellofemoral joints when performing HTO.

The purpose of this study is to compare the progression rate of bone union and clinical outcomes of opening wedge high tibial osteotomy (OWHTO) using allogenous bone chip or tri-calcium phosphate (TCP) granule as bone graft materials. The hypothesis was that the bone union progression in OWHTOs using TCP granule grafts would be comparable to that of OWHTOs using allogenous bone chip grafts. Between 2011 and 2013, 54 patients who had undergone OWHTO for genu varum and osteoarthritis were randomized to one of the two groups at five centres. TCP granule was used to fill the defect in 27 patients and lyophilized allogenous bone chip was used in the other 27 patients. The degree of bone union was classified on a five-point scale and evaluated using plain radiographs of the knee at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, pain Visual Analogue Scale (VAS) score and complications were also evaluated. The highest degree of bone union observed at 6 and 12 months postoperatively was grade 4, and the number of cases of union progression at each time-point was not significantly different between the two groups (p > 0.05). WOMAC and pain VAS scores also showed no differences between the two groups. No complications were observed during the 12-month period following OWHTO in either group. OWHTO using TCP granule bone substitute showed similar bone union rates and clinical outcomes compared to allogenous bone chip grafts. TCP granule can be used as bone substitutes instead of allogenous bone chip grafts in OWHTO. Level 1.

BACKGROUND Some patients with recurrent symptomatic instability after primary anterior cruciate ligament (ACL) reconstruction have an extension deficiency (ED). This study (a) compared preoperative clinical conditions between the ED and non-ED groups undergoing revision ACL reconstruction, (b) documented clinical and arthroscopic findings in ACL-reconstructed patients with reinstability and ED, and (c) determined whether the ED could be resolved and whether the clinical results of revision surgery differed between the ED and non-ED groups. METHODS This study included 58 patients who underwent revision ACL reconstruction. Patients were divided into the ED and non-ED groups. Preoperatively, the demographics and clinical conditions of the two groups were compared. Intraoperatively, the pathological structures that related to ED were documented. After surgery, the degree of postoperative ED and functional outcomes were compared between the two groups at 2-year follow-up. RESULTS The International Knee Documentation Committee subjective score and SF-36 physical component summary scores were worse in the ED group than the non-ED group preoperatively (54 vs 48 [P = 0.014]; 42 vs 39 [P = 0.031], respectively). Intraoperatively, the ED group showed significantly more frequent graft malposition (50% vs 5%), anvil osteophytes (44% vs 0%), and scarring around posterior intercondylar notch (100% vs 0%). However, there was no difference in the degree of postoperative ED and functional outcome between the two groups at follow-up. CONCLUSIONS ED in patients with recurrent instability after primary ACL reconstruction could be treated with good clinical result by addressing the pathological conditions causing ED in addition to ACL re-reconstruction.

Background We sought to document the incidences of deep vein thrombosis (DVT) before and after total knee arthroplasty (TKA). In addition, we aimed to explor whether routine preoperative DVT evaluation was useful to establish DVT treatment strategies after TKA. Finally, we wanted to evaluate whether the incidences of DVT differed between patients undergoing unilateral and staged bilateral TKA within the same hospitalization period. Methods The retrospective study included 153 consecutive patients (253 knees) with osteoarthritis who underwent primary TKA. After surgery, mechanical compression devices (only) were used for DVT prophylaxis. DVT status before and after TKA was determined via 128-row, multidetector, computed tomography/indirect venography. Results Overall, the preoperative DVT incidence was 2.6% per patient and 1.6% per knee. All preoperative DVTs were distal in nature and asymptomatic. After TKA, newly developed thrombi were evident in various calf veins, without propagation of any pre-existing thrombi. Postoperatively, the overall incidences of DVT were 69.9% per patient and 58.5% per knee. The DVT incidences were 66% per patient and 69.8% per knee in the unilateral TKA group. In contrast, the incidences were 72% per patient and 55.5% per knee in the staged bilateral TKA group. There was one case of symptomatic distal (unilateral TKA; 0.65% per patient and 0.4% per knee) and proximal DVT (bilateral TKA; 0.65% per patient and 0.4% per knee), respectively. Conclusions The incidence of symptomatic DVT was low in Asian patients treated with mechanical compression devices alone, although substantial portion of patients had DVT after surgery. Routine preoperative DVT evaluation is probably not necessary; preoperative DVT was rare and of limited clinical relevance. Furthermore, staged bilateral TKA during a single period of hospitalization does not increase the incidence of DVT.

Background We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing. Methods This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs. Ten-year survivorship analysis was performed using the Kaplan–Meier method with additional surgery for any reason as the end-point. Furthermore, long-term clinical and radiographic results of 109 knees (74%; 84 patients) with more than 10-year follow-up were analyzed. Ten-year survivorship and long-term outcomes after surgery were determined, and outcomes were compared between patients with and without patellar resurfacing. Results The cumulative survival rate of the single-radius posterior-stabilized TKA of 148 knees was 97.7% (95% confidence interval, 93.1%–99.3%) at 10 years after surgery. Three knees required additional surgery during the 10-year follow-up because of one case of instability and two cases of periprosthetic infections. Mean postoperative Knee Society knee score and function score were 97 points and 75 points, respectively. There were no cases of aseptic loosening of the prosthesis, even though a non-progressive radiolucent line was found in 10 (9%) knees. There were no differences in postoperative scores and degree of patellar tilt and displacement between patients with and without patellar resurfacing. Conclusions Single-radius, posterior-stabilized TKA showed satisfactory long-term clinical and radiographic outcomes in Asian patients regardless of patellar resurfacing, with comparable survivorship to that reported in westerners.

Background: Although a few studies have reported the incidence of deep vein thrombosis (DVT) after opening-wedge high tibial osteotomy (OWHTO), previous studies focused only on symptomatic DVT. Information is lacking regarding the overall incidence of DVT after OWHTO, thrombus location, and the relationship between DVT and clinical outcome. Purpose: To determine the overall incidence of DVT and classify the location of DVT after OWHTO. We also determined whether significant differences in clinical improvement exist in patients with and without DVT at 6 months and at 2 years after OWHTO. Study Design: Case-control study; Level of evidence, 3. Methods: This study included 46 patients (47 knees) who underwent OWHTO. All patients were instructed to perform knee range of motion exercises and partial weightbearing after drain removal. None of the patients received a chemoprophylaxis for DVT except intermittent pneumatic compression. DVT was diagnosed using 128-row multidetector computed tomography performed before discharge on the fourth postoperative day. The location was classified into 6 segments in the distal portion (muscular and axial veins) and proximal portion (popliteal, femoral, and common femoral veins and veins located above the iliac vein). International Knee Documentation Committee (IKDC) score was assessed preoperatively and postoperatively at 6 months, 1 year, and 2 years using a linear mixed model. Results: Although the incidence of symptomatic DVT was 8.5% (n = 4), the overall incidence of early DVT was 44.7% (n = 21). All DVTs were located in the distal portion of the lower extremity vein, and 76.2% of the DVTs were located in an axial vein. The IKDC scores were 33.6 ± 7.2 and 35.3 ± 9.1 ( P = .910) preoperatively, 38.1 ± 5.6 and 40.6 ± 8.4 ( P = .531) at 6 months after surgery, and 44.8 ± 6.9 and 45.9 ± 11.4 ( P = .786) at 2 years after surgery in patients without and those with DVT, respectively. Conclusion: The overall incidence of early DVT after OWHTO was 44.7%. DVT after OWHTO was found particularly around the osteotomy site (76.2%). Patients with DVT did not have inferior short-term clinical outcomes after surgery.

Background To date, there has been no established protocol regarding the timing of the scheduled administration of antiemetics in total knee arthroplasty (TKA). Previous prospective studies analyzing the scheduled use of antiemetics differed in the timing at which the drugs were administered. However, antiemetic drugs are not administered post-operatively until noxious stimuli caused by drugs used during anesthesia and operative procedures. The purpose of this study was 1) to determine whether preoperative scheduled administration of an antiemetic drug can reduce iatrogenic postoperative nausea and vomiting (PONV) in TKA compared to postoperative administration, and 2) to determine whether there was a difference in postoperative pain, patient satisfaction, and complications after TKA between pre- and postoperative administrations.Methods This retrospective study included patients who were assigned to either intravenous administration of the antiemetic drug (ramosetron) 1 hour before surgery (pre-injection group: 50 patients) or at the end of surgery (post-injection group: 51 patients). The incidence of PONV and the frequency of rescue medicine use were recorded until 48 hours postoperation. Postoperative pain level and satisfaction were also assessed using the visual analogue scale (VAS). Possible complications associated with serotonin receptor antagonists; for example, headaches, dizziness, and drowsiness were also assessed.Results The incidence of nausea events was lower in the pre-injection group than in the post-injection group. However, there was no difference between the two groups in terms of frequency of vomiting events and the use of rescue medicine for PONV. Also, postoperative pain, satisfaction scores, and incidence of complications were not different between the two groups.Conclusions The patients with preoperative scheduled administration of antiemetics showed lower incidence of nausea events than those with postoperative administration. However, it is difficult to conclude that the extent of the effect was clinically significant. Further research is needed to determine the optimal timing and method for more effective antiemetic treatment.

Osteoarthritis (OA) is a prevalent degenerative disease, which involves progressive and irreversible destruction of cartilage matrix. Despite efforts to reconstruct cartilage matrix in osteoarthritic joints, it has been a difficult task as adult cartilage exhibits marginal repair capacity. Here we report the identification of tankyrase as a regulator of the cartilage anabolism axis based on systems-level factor analysis of mouse reference populations. Tankyrase inhibition drives the expression of a cartilage-signature matrisome and elicits a transcriptomic pattern that is inversely correlated with OA progression. Furthermore, tankyrase inhibitors ameliorate surgically induced OA in mice, and stem cell transplantation coupled with tankyrase knockdown results in superior regeneration of cartilage lesions. Mechanistically, the pro-regenerative features of tankyrase inhibition are mainly triggered by uncoupling SOX9 from a poly(ADP-ribosyl)ation (PARylation)-dependent protein degradation pathway. Our findings provide insights into the development of future OA therapies aimed at reconstruction of articular cartilage., Osteoarthritis results from the progressive destruction of cartilage matrix. Here, Kim et al. identify tankyrase as a regulator of cartilage matrix anabolism, and find that tankyrase inhibition, by preventing SOX9 PARylation, protects from cartilage destruction in a mouse model of osteoarthritis.

BackgroundWe sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) and clinical outcomes following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system.MethodsThis retrospective study included 130 consecutive patients (184 knees) with osteoarthritis who underwent primary posterior cruciate ligament (PCL)-substituting fixed-bearing TKA. The difference between preoperative and postoperative PCO and PCOR values were calculated. Clinical outcomes including ROM and Western Ontario and McMaster University (WOMAC) scores were evaluated. Furthermore, multiple linear regression analysis was performed to determine the factors related to postoperative ROM in each referencing system.ResultsThe postoperative PCO was greater in the AR group (28.4 mm) than in the PR group (27.4 mm), whereas the PCO was more consistently preserved in the PR group. The mean postoperative ROM after TKA was greater in the AR group (129°) than in the PR group (122°), whereas improvement in WOMAC score did not differ between the two groups. Preoperative ROM was the only factor related to postoperative ROM in both groups.ConclusionsThere was no difference in postoperative PCO in AR and PR group and the PCO was not associated with postoperative ROM. PCO was more consistently preserved after surgery in the PR group. The postoperative PCO and PCOR changes did not affect the postoperative ROM. Furthermore, similar clinical outcomes were achieved in the AR and PR groups.Trial registrationRetrospectively registered (Trial registration number:06-2010-110).

There is little information about the management and clinical outcomes of the periprosthetic fracture after total knee arthroplasty (TKA) with a stem extension. The purposes of this study were to demonstrate management of the periprosthetic fractures after TKA with a stem extension, to report treatment outcomes, and to determine whether dual-plate fixation is superior to single-plate fixation regarding the radiographic bone union time and incidence of metal failure. This retrospective study included 15 knees with periprosthetic fractures after TKA using a stem extension. We demonstrated the fracture characteristics and management according to the fracture location and implant stability. The radiographic union time was determined. Complications, range of motion, and functional outcomes, including Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score were assessed. Periprosthetic fractures after TKA with stem extension were 1 metaphyseal fracture without implant loosening, 7 diaphyseal fractures adjacent to the stem without implant loosening, 3 diaphyseal fractures away from the stem without implant loosening, and 4 fractures with implant loosening. Treatment included immobilization using a long leg cast, open reduction and internal fixation (ORIF), and re-revision TKA. There was no difference in functional outcomes and range of motion pre- and posttreatment. The complications included 2 cases of subsequent implant loosening. Patients in the dual-plating required a shorter bony union time than those in the single-plating (2.4 ± 1.1 vs 7.4 ± 2.2 months; P = .003). Periprosthetic fractures after TKA with stem extension could be managed individually according to the fracture location and implant stability. Complications were not uncommon even if patients were able to return to their preinjury functional level posttreatment. To avoid complications after ORIF, the dual plate was superior to the single plate, and subtle implant loosening should not be overlooked.

Repairs of orbital post-traumatic and extensive malignant defects remain a major surgical challenge, in view of follow-up outcomes. Incorrect surgical management of injured facial structures results in cosmetic, ophthalmic, and social aftereffects. A custom-made knitted TiNi-based mesh (KTNM) endograft was employed to overcome post-surgical complications and post-resected lesions of the orbital area. Preoperative high-resolution computed tomography (CT) imaging and CAD modelling were used to design the customized KTNM in each case. Twenty-five patients underwent surgery utilizing the suggested technique, from 2014 to 2019. In all documented cases, resolution of the ophthalmic malfunction was noted in the early period. Follow-up observation evidenced no relapsed enophthalmos, hypoglobus, or diplopia as late complications. The findings emanating from our clinical observations allow us to claim that the KTNM indicated a high level of biocompatibility. It is simply modified intraoperatively to attach any desired shape/size for implantation and can also be screw-fixed, providing a good supporting ability. The KTNM precisely renders orbitozygomatic outlines and orbital floor, thus recovering the anatomical structure, and is regarded as an attractive alternative to Ti-based meshes and plates. Additionally, we report one of the studied cases, where good functional and cosmetic outcomes have been achieved.

Objective: To evaluate in vivo application of a new surgical mesh knitted of the TiNi-based filament as a graft substitute for the repair of cranial defects in a rabbit model. Materials and methods: The study was carried out in 69 male rabbits. Full-thickness excisional wounds of 15.0 by 15.0 mm were bilaterally created in the parietotemporal area by symmetrical dissection, leaving the dura mater intact. The lesion was treated by the knitted TiNi mesh graft (KTNM) that has been preoperatively laminated by twice-folding. Four groups were assigned: animals were grafted with the KTNM made of 40 μm (Group I), 60 μm (Group II), and 90 μm (Group III) thick TiNi-based filament, whereas in the sham-surgery control Group IV defects were left unrepaired. For histomorphological examination of the in vivo osteogenic capability, samples were taken at 7, 14, 21, 28 and 35 days postoperatively. Three series of studies in each experimental group and 3 cases in the control group (total number of cases—135) have been histomorphologically evaluated. Results: The diameter of a filament used in the KTNM fabrication has no significant impact on the osteogenic ability, but nonetheless, Group I tended to has rapid regeneration in histological assessment. In all experimental groups, an organotypic stratified-spongy osseous tissue was noted to form in the periphery layers, whereas the compact, semi-mature connective tissue was detected within the core horizons by the end of the study. A newly formed bone-KTNM interface was noted to modulate and facilitate the regenerative process therein observed, which enables us to expect that anatomical and functional features of the brain, cranium and dura mater can be completely restored by osseous wound-healing. Conclusion: These findings thus shed light on the promising tissue-engineering approach and unsophisticated surgical technique utilising KTNMs, which can repair even large skull lesions.

Although the importance of quadriceps femoris function was reported previously, little is known about volume-related factors and their effects on clinical outcomes after total knee arthroplasty (TKA). We sought to determine whether there was a bilateral difference in vastus medialis muscle volume measured on single-photon emission computed tomography–computed tomography (SPECT-CT) in patients who underwent unilateral TKA. We also aimed to determine whether vastus medialis volume was related to osteoarthritis (OA) severity or scintigraphic uptake degree around the knee joint on SPECT-CT. And finally, we attempted to investigate the factors, such as vastus medialis volume and scintigraphic uptake degree, associated with the functional outcomes of TKA. This retrospective study included 50 patients (41 female, 9 male) undergone unilateral TKA due to primary OA. The maximal cross-sectional area of the vastus medialis was measured on axial SPECT-CT images. Scintigraphic uptake degrees and Kellgren-Lawrence (K-L) grade at the tibiofemoral joints were assessed. We compared maximal cross-sectional area of the vastus medialis on SPECT-CT for difference of bilateral lower limbs. We also analyzed the relationship between volume of vastus medialis and scintigraphic uptake measured on SPECT-CT and the severity of OA on conventional radiographs. The clinical outcomes were evaluated using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index at baseline and at 1 and 2 years after surgery. The relationship between preoperative muscle volume and scintigraphic uptake on SPECT-CT and WOMAC index was analyzed. The amount of muscle volume measured on SPECT-CT was smaller in operated limb in patients who underwent unilateral TKA. Preoperative vastus medialis muscle volume was not related to preoperative OA severity measured on conventional radiographs and scintigraphic uptake on SPECT-CT. However, a decreased vastus medialis muscle volume was related to worse clinical outcomes after TKA (P = .045), whereas the degree of scintigraphic uptake on SPECT-CT was not associated with postoperative clinical outcomes. Muscle volume of vastus medialis was decreased in the operated knee than in the nonoperated knee, and that was correlated with worse postoperative results. Even if the preoperative volume of vastus medialis were not related to OA severity on conventional radiographs and scintigraphic uptake on SPECT-CT, preservation and improvement of the muscle mass of the knee undergoing TKA is important.

The aim of this study was to determine whether the infection control rate of a modified debridement, antibiotics, and implant retention (DAIR) protocol (DAIR with antibiotic-impregnated cement beads) is comparable to that of 2-stage revision for acute periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). We also aimed to determine whether this modified DAIR technique produced better clinical results than those obtained using 2-stage revision in terms of functional outcome, range of motion (ROM), and patient satisfaction at 2 years after surgery. This retrospective comparative study included patients who underwent modified DAIR (7 patients, 9 knees) or 2-stage revision (8 patients, 9 knees) for acute PJI of the knee joint. Infection control rate, functional outcome measured using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, ROM and patient satisfaction were compared between the two groups. There was no difference in infection control rates between the modified DAIR and 2-stage revision groups (78% vs 78%, respectively). In contrast, surgical outcome in the modified DAIR group was tended to be better than 2-stage revision group, but it did not reach statistical significance. Median maximal range of flexion was 103° in the modified DAIR group and it was 90° in the 2-stage group (P = .191). In addition, the median WOMAC function score was 24 in the modified DAIR group and it was 30 in the 2-stage group (P = .076). Median patient satisfaction measured using visual analogue scale was 8 in the modified DAIR group and 5 in the 2-stage group (P = .069). The infection control rates of the modified DAIR protocol and 2-stage revision protocol were similar for the treatment of acute PJI of the knee joint. However, the modified DAIR protocol could not provide substantially increased functional outcomes and patient satisfaction compared to 2-stage revision. Therefore, the modified DAIR technique should be considered to be of limited use in patients with high surgical morbidity.

A two-stage approach to total knee arthroplasty (TKA) using an antibiotic-impregnated articulating cement spacer is an option for an infected arthritic knee. Vancomycin combined with broad-spectrum antibiotics can be used to make an antibiotic-impregnated articulating cement spacer. Causative organisms are sometimes not confirmed before surgery. Joint infections of multidrug-resistant organisms are increasing. Therefore, routine combinations of antibiotics may not be effective. We present a case of a patient who developed vancomycin-resistant Pseudomonas aeruginosa infection in an arthritic knee. A 71-year-old man was initially diagnosed with pyogenic arthritis caused by Staphylococcus aureus. He underwent arthroscopic debridement elsewhere. However, the infection persisted. He was referred to our hospital, and we performed a two-stage TKA using a vancomycin-based antibiotic-impregnated articulating cement spacer. Vancomycin-resistant P. aeruginosa was identified after surgery. Intravenous colistin was added. However, this failed, either because vancomycin was not effective against P. aeruginosa, or because insufficient systemic colistin due to colistin-induced acute kidney injury. Therefore, debridement was repeated, and colistin-loaded cement spacer was inserted. The spacer delivered high concentrations of colistin to the infected joint with decreased systemic effects. Thus, less systemic colistin was used. The infection was controlled without recurrent acute kidney injury. One year after surgery, conversion to TKA was successfully performed. A two-stage approach to TKA using a colistin-loaded articulating cement spacer can be used for an arthritic knee infected by vancomycin-resistant P. aeruginosa. Furthermore, local administration of colistin using a cement spacer can reduce the systemic side effects of colistin.

Background Occasionally, patients experience new or increased ankle pain following total knee arthroplasty (TKA). The aims of this study were to determine (1) how the correction of varus malalignment of the lower limb following TKA affected changes in alignment of the ankle and hindfoot, (2) the difference in changes in alignment of the ankle and hindfoot between patients with and without ankle osteoarthritis (OA), and (3) whether the rate of ankle pain and the clinical outcome following TKA differed between the 2 groups. Methods We retrospectively reviewed prospectively collected data of 56 patients (99 knees) treated with TKA. Among these cases, concomitant ankle OA was found in 24 ankles. Radiographic parameters of lower-limb, ankle, and hindfoot alignment were measured preoperatively and 2 years postoperatively. In addition, ankle pain and clinical outcome 2 years after TKA were compared between patients with and without ankle OA. Results The orientation of the ankle joint line relative to the ground improved from 9.4° of varus to 3.4° of varus, and the valgus compensation of the hindfoot for the varus tilt of the ankle joint showed a 2.2° decrease following TKA. Patients in the group with ankle OA showed decreased flexibility of the hindfoot resulting in less preoperative valgus compensation (p = 0.022) compared with the group without ankle OA. The postoperative hindfoot alignment was similar between the 2 groups because of the smaller amount of change in patients with ankle OA. The group with ankle OA had a higher rate of increased ankle pain (38% compared with 16%) as well as a worse Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (mean of 22.2 compared with 14.2) following TKA. Conclusions A considerable proportion of patients who underwent TKA had concomitant ankle OA with reduced flexibility of the hindfoot. These patients experienced increased ankle pain following TKA and a worse clinical outcome. Level of evidence Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The purpose of this study was to assess the overall clinical results and range of motion (ROM) after total knee arthroplasty (TKA) in patients with preoperative stiffness. We also aimed to determine whether the severity or cause of the stiffness can affect the clinical outcome after surgery. This retrospective study included 122 knees (117 patients) with follow-up of more than 2 years (mean age, 64.3 years). TKA was performed using posterior-stabilized, varus-valgus constrained (VVC), and hinged prostheses. To determine the effect of the severity of stiffness on the clinical outcome, the subjects were divided into two groups: the severe group (preoperative ROM ≤ 50°; 18 knees) and the moderate group (preoperative ROM, 50°-90°; 104 knees). Then, clinical results and ROM were compared according to the severity or cause of preoperative stiffness. After surgery, preoperative ROM (mean, 78°; range, 25°- 90°) was improved (mean, 107°; range, 70°- 130°). The severe group more frequently used the VVC or hinged prostheses (72% vs. 18%). Furthermore, the severe group had worse knee and function scores as well as more complications (33% vs. 13%), even though the severe group had a greater ROM increment (47° vs. 27°) after surgery. Patients with osteoarthritis and rheumatoid arthritis showed better ROM and clinical results compared to patients with infectious or traumatic arthritis. Although TKA in stiff knees can be successful, the results are inferior in knees with severe stiffness and knees with infectious or traumatic arthritis.

The study aimed to explore the in vivo applicability of intracorporeal constructions with hepatocytes cultured in the porous TiNi-based scaffold (PTNS). We also sought to determine whether application of hepatocytes cultured in the PTNS was superior to sham operation or simple hepatocyte injection in terms of restoration of liver functions and survival time in a CCl4-induced hepatitis rat model. Using 12 animals, image analysis of SEM data of in vivo hepatocyte evolution in the PTNS was carried out. In addition, 200 animals were assigned to explore the experimental groups as follows: (1) Group I, control group; (2) Group II, animals with toxic hepatitis; (3) Group III, animals with toxic hepatitis followed by implantation of cell-free PTNS (sham-surgery); 4) Group IV, animals with toxic hepatitis followed by infusion of hepatocytes only (15 × 106 cells ml−1); 5) Group V, animals with toxic hepatitis followed by implantation of hepatocytes cultured in the PTNS. In the SEM analysis, hepatocytes demonstrated good adhesion and proliferation in the pore space of the PTNS. Moreover, mature tissue comprising both colloidal and fibrous components filled the pore body by 95% in 28 days. Concerning restoration of liver function, Group V showed a significant reduction of serum alanine aminotransferase level compared to Group II. Group IV also showed a significant decrease in ALT level at 15 days. However, the level of ALT increased at 30 days, and the level was similar with results of the group II. This situation probably was caused by a short-term effect of hepatocyte injection only. The change patterns of serum protein, lactate, albumin, fibrinogen, and total bilirubin levels were similar to the results of ALT. The survival time of animals was significantly longer in Group V. These findings showed possible abilities of the PTNS as a scaffold to support the hepatocellular metabolism. Overall, this study sheds a different light on how the implantable «auxiliary liver» by engrafting the cultured PTNS substitutes the missing hepatic function without the need to replace the whole liver.

Purpose To determine what proportion of patients visiting a tertiary knee clinic had pre-obtained knee magnetic resonance imaging (MRI) and to assess the impact of pre-obtained knee MRI on the selection of treatment plans. Materials and Methods Six hundred and eighty patients were enrolled from patients who visited our knee clinic during a 6-month period. The proportion of patients with pre-obtained knee MRI was calculated, and associations of sociodemographic factors, disease category, and finally selected treatment options with knee MRI pre-obtainment were investigated. A utility assessment panel of five orthopaedic surgeons was formed and established utility assessment criteria. Two rounds of utility assessment (before and after MRI review) were performed. Results Of the 680 patients, 185 (27%) had pre-obtained knee MRI. In the first round of utility assessment, 39%, 18%, and 43% of the 185 knee MRIs were evaluated as useful, equivocal, and arguably useless, respectively, and almost identical results were obtained in the second round. The proportion of assessed 'useful MRI' was higher in sports related injury (84%) and other conditions (91%) than in degenerative joint disease (18%) and nonspecific knee pain (31%). Utility assessment results among panels varied little for practice patterns and education duration. Conclusions This study suggests clinicians should reconsider and counsel patients the expected utility of knee MRI acquisition.

Purpose The aim of this study was to determine the outcomes of bursoscopic ossicle excision in young and active patients with unresolved Osgood-Schlatter disease. Methods This retrospective study included 18 male military recruits. A direct bursoscopic ossicle excision was performed using low anterolateral and low anteromedial portals. Outcomes were evaluated using the Lysholm knee score, pain score on a visual analog scale (VAS) (from 0 to 10), and Tegner activity scale score. In addition, patients were asked whether they could kneel or squat and whether they were able to return to their duty after surgery. Patient satisfaction was evaluated using the VAS and by asking whether patients thought that the prominence of the tibial tuberosity was reduced and whether they would recommend the same surgical treatment to others. Complications after surgery were also evaluated. Results The mean Lysholm knee score was 71 preoperatively and improved to 99 after surgery. The mean VAS pain score was 6.5 in the preoperative period and decreased to 0.9 after surgery. In addition, the mean Tegner activity scale score improved from 2.7 preoperatively to 6.2 at final follow-up. However, 4 patients were not able to return to their duty, and 4 patients still had difficulties with kneeling after surgery. A superficial infection occurred in 1 patient, and a recurrent ossicle formation was found in 1 patient. Of 18 patients, 17 were satisfied with their surgical outcomes, and the mean VAS score for patient satisfaction was 8.8. Furthermore, all but 1 patient would recommend the same surgical treatment to others. However, 6 patients did not believe that the prominence of the tibial tuberosity was reduced. Conclusions Bursoscopic ossicle excision showed satisfactory outcomes in selective young and active patients with persistent symptoms. However, bursoscopic surgery showed limitation in reducing the prominence of the tibial tuberosity. Level of Evidence Level IV, therapeutic case series.

A progressive loss of cartilage matrix leads to the development of osteoarthritis (OA). Matrix homeostasis is disturbed in OA cartilage as the result of reduced production of cartilage-specific matrix and increased secretion of catabolic mediators by chondrocytes. Chondrocyte senescence is a crucial cellular event contributing to such imbalance in matrix metabolism during OA development. Here, we identify miR-204 as a markedly up-regulated microRNA in OA cartilage. miR-204 is induced by transcription factors GATA4 and NF-κB in response to senescence signals. Up-regulated miR-204 simultaneously targets multiple components of the sulfated proteoglycan (PG) biosynthesis pathway, effectively shutting down PG anabolism. Ectopic expression of miR-204 in joints triggers spontaneous cartilage loss and OA development, whereas miR-204 inhibition ameliorates experimental OA, with concomitant recovery of PG synthesis and suppression of inflammatory senescence-associated secretory phenotype (SASP) factors in cartilage. Collectively, we unravel a stress-activated senescence pathway that underlies disrupted matrix homeostasis in OA cartilage.

Purpose To determine whether there are differences between adjustable-length loop and fixed-length loop devices in terms of the amount of displacement, temporal pattern of displacement, and ultimate failure load when tested using 4,500 cycles of sinusoidal loading with high loads (100-400 N). Methods Two cortical suspension devices with a fixed- or adjustable-length loop were tested. For our comparisons, a 20-mm fixed-length loop device and a fixed-length loop device with the same loop length were used. Comparisons between the devices used both a device-only model (DOM) and a device–bone–soft-tissue graft construct model (CM). Results In the DOM, the adjustable-length loop device showed weaker mechanical properties. Mean cumulative peak displacement was 1.91 mm for the adjustable-length loop device and 0.74 mm for the fixed-length loop device ( P = .001). The displacement of the adjustable-length loop device increased between 1,000 and 4,500 cycles; in contrast, that of the fixed-length loop device reached a plateau. However, there was never displacement greater than 3 mm. In addition, the adjustable-length loop device showed a weaker ultimate failure load (925 N vs 1,410 N, P = .001). In the CM, the difference in cumulative peak displacement between the 2 groups decreased and did not reach statistical significance. The displacement of both devices showed a similar pattern. In addition, there was no difference in ultimate failure load between the 2 groups. Conclusions There was no significant difference in terms of total displacement, temporal pattern of displacement, and ultimate failure load between the 2 devices in the CM, which is the more clinically relevant model. Furthermore, even in the DOM, the difference in total displacement was small and did not reach a clinically meaningful level. Therefore, both devices can be used effectively during anterior cruciate ligament reconstruction with soft-tissue graft. Clinical Relevance Both femoral cortical suspension devices with adjustable- and fixed-length loops can be used with similar mechanical properties during anterior cruciate ligament reconstruction.

Purpose We aimed to determine 1) whether dropout rate decreased and 2) whether health care providers' perceptions were changed with continued improvements of contents of clinical pathway (CP) for total knee arthroplasty (TKA). Materials and Methods This retrospective study included two separate analyses of patients and health care providers. In the analysis of patients, dropout rates and reasons were evaluated in two cohorts of patients who underwent TKA with CP applied at two different time periods (384 patients from 2009 to 2010 and 242 patients from 2012 to 2013). Contents of CP were continuously improved during the 3-year interval. Self-administered questionnaire surveys targeted to health care providers were carried out twice (2010 and 2013) and compared. Results Dropout rate decreased from 19.1% in the first time period to 10.4% in the second time period. Although overall satisfaction of care providers was high at both time-points, doctors had more favorable perceptions than nurses; most positive changes of perception were noted in nurses. The health care providers' perceptions for potential concerns of CP were improved while the perceptions for potential benefits and satisfaction were maintained. Conclusions Continuously improved CP has increased feasibility for TKA patients and reduced health care providers' concern about its value. We propose that CP can be implemented and actively used to improve the outcomes and efficacy of patient care for TKA, regardless of the rotation of care providers.

We hypothesized that the circumstances of the two consecutive operations of a simultaneous bilateral total knee arthroplasty (TKA) are different, and could lead to different outcomes of overlapping bilateral TKAs. Both knees of 420 subjects were evaluated in the current study. In the second TKA, there were more incidence rates of outlier in mechanical femoro-tibial angle (16.2% vs. 9.0%), more blood loss (735 vs. 656 mL), and longer operation time (61, 58 minutes respectively), as compared to the first TKA, while no significant differences in clinical outcomes. In conclusion, there were no significant differences in the clinical outcomes even though few distinct outcomes due to different circumstances of the surgery. Awareness of these findings can help the continued success of bilateral TKA in an increasing patient population.

We sought to determine the relationship between the mechanical axis-derived and the anatomic landmark-derived femoral rotational axes using three dimensional computed tomographic images of 20 lower extremities. The mechanical axis-derived femoral rotational axis was created on the distal articular surface of the femur using coronal mechanical limb axis and the reconstructed images of the femur. Then, we measured the angular difference between mechanical axis-derived and anatomic landmark-derived femoral rotational axes. The mechanical axis-derived femoral rotational axis was externally rotated with a mean of 2.2° (range, 0 to 4.7°; SD, 1.0) compared with the surgical epicondylar axis. Our findings should be considered to obtain a proper femoral rotational axis in total knee arthroplasty.

Staged bilateral total knee arthroplasty (TKA) may provide an ideal clinical model for the study of central sensitization. In staged TKA, hyperalgesia may be induced as a result of repeated surgical injury possibly via central sensitization, which can decrease functional outcomes. Therefore, we hypothesized that in staged bilateral TKA, patients would have greater pain in the second operated knee than in the first. Thirty patients undergoing staged bilateral TKA at a 1-week interval were enrolled. Postoperative pain, which was reported on the basis of a visual analog scale (VAS; primary outcome) at rest and at maximum knee flexion, and the amount of patient-controlled analgesic (i.v. fentanyl) and rescue analgesic (i.v. ketoprofen; secondary outcomes) administered during the 48 h after the operation, were compared between the first and second TKA. VAS scores at rest and at maximum knee flexion were greater on the second operated knee (P.001 and P.01, respectively). The cumulative amounts of patient-controlled analgesic and the rescue analgesic were greater in the second than in the first TKA (P.001 and P.05, respectively). Patients undergoing staged bilateral TKA experience greater postoperative pain in the second operated knee than the first. This suggests extension of hyperalgesia beyond the initially injured site to remote regions after surgical injury, in which central sensitization may be involved. Therapeutic approaches to reduce such hyperalgesia induced in the course of staged operations are required.

Background Failed ACL reconstruction frequently is accompanied by irreparable medial meniscal tear and/or visible osteoarthritis (OA) in the medial tibiofemoral joint. Thus, assessment for the presence of varus malalignment is important in caring for patients in whom revision ACL reconstruction is considered.

Background Selective bundle anterior cruciate ligament (ACL) reconstruction and/or remnant ACL preservation may be reasonable options for some patients. However, the frequency of isolated anteromedial (AM) or posterolateral (PL) bundle injuries in patients undergoing ACL reconstruction is unknown, and the value of MRI for prediction of this injury pattern is likewise unknown.