Femoral morphology affects postoperative alignment of the lower extremities in hybrid closed-wedge high tibial osteotomy.

INTRODUCTION: This study aimed to determine correction error predictors of lower extremitiy alignment after hybrid closed-wedge high tibial osteotomy (HCWHTO). MATERIALS AND METHODS: From 2011 to 2015, 102 knees in 75 patients with medial compartment knee osteoarthritis of the knee and varus knee deformities who underwent HCWHTO were evaluated in this retrospective study with a minimum 2-year follow-up. Preoperative radiological parameters including weight-bearing line ratio (WBL ratio), mechanical leg axis angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and JLCA under varus or valgus stress were measured. The knees were divided into the following three groups based on the WBL ratio on average 54 months after procedure: acceptable (WBL crossing the tibial plateau between 50 and 70%), under-correction (< 50%), and overcorrection (> 70%). A multiple regression analysis was performed to evaluate predictors that could influence postoperative WBL ratio and cut-off values of predictive preoperative factors was analysed. RESULTS: Significant differences in pre- and postoperative WBL ratios and mechanical leg axis angles were found. Preoperative mLDFA in the under-correction group (89.4° ± 2.1°) was significantly higher than that in the overcorrection group (87.4° ± 2.2°) (p = 0.015), while other preoperative parameters revealed no significant differences. The postoperative MPTA in the under-correction group (92.1° ± 3.7°) was significantly lower than that in the other two groups (p = 0.005 and p = 0.0001, respectively), while there was no significant change between the acceptable (94.6° ± 3.4°) and the overcorrection (96.7° ± 3.2°) groups. Multiple regression analysis revealed that mLDFA (ß = - 0.316; p = 0.010) had a significant impact on postoperative WBLR. The cut-off value for under-correction of mLDFA was 89.5°and sensitivity and specificity were 53.6 and 71.6%, respectively (p = 0.014). CONCLUSIONS: Preoperative mLDFA is significantly associated with postoperative alignment in HCWHTO. While postoperative MPTA is important, disregarding the preoperative mLDFA may bears a high risk of malcorrection. Varus alignment of the knee with larger mLDFA may be an indication for not only HCWHTO, but also for distal femoral osteotomy.

Faster union rate and better clinical outcomes using autologous bone graft after medial opening wedge high tibial osteotomy.

PURPOSE: To compare the radiological bone union rate after medial opening wedge high tibial osteotomy (MOW-HTO) and stabilization using a TomoFix™ plate (Synthes, Oberdorf, Switzerland) in three patient groups. METHODS: Retrospective analysis of 137 knees that underwent MOW-HTO between January 2014 and January 2017 was using a TomoFix™ plate. Osteotomy gaps were filled with ß-tricalcium phosphate (ß-TCP) (group A), left unfilled (group B), and subject to autologous bone graft and ß-TCP (group C). Radiological bone union using simple radiography was determined by a modified version of the Brosset et al. osteotomy filling index. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) and Lysholm score. Statistical analyses using the Chi-square and ANOVA tests were performed between the groups. RESULTS: The mean time for radiological bone union was 8.3 ± 3.1 months in group A, 7.2 ± 3.2 in group B and 3.4 ± 1.5 in group C (p = 0.001). There was statistically significant faster bone union in Group C. If the opening distance was more than 10 mm, group A united in 8.6 ± 3.6 months, group B in 8.8 ± 3.4, and group C in 3.5 ± 1.7 (p = 0.001). IKDC and Lysholm knee scores improved significantly (p = 0.004 for IKDC and 0.001 for Lysholm knee scores) in group C when compared to groups A and B at sixth month follow-up. At final follow-up, there was no difference in IKDC and Lysholm knee scores. Less delayed union occurred in group C. CONCLUSIONS: MOW-HTO with autologous bone graft and ß-TCP had the fastest radiological bone union and best clinical scores at 6 month follow-up. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Hybrid closed wedge high tibial osteotomy improves patellofemoral joint congruity compared with open wedge high tibial osteotomy.

PURPOSE: To evaluate clinical outcomes and radiographic changes in patellofemoral (PF) joint congruity between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge HTO (HCWHTO). METHODS: From 2011 to 2013, 36 knees in 31 patients who underwent OWHTO and 21 knees in 17 patients who underwent HCWHTO were evaluated in this retrospective study with a minimum 5-year follow-up. Radiological outcomes including hip-knee-ankle angle (HKA), femoral patellar height index (FPHI), preoperative PF osteoarthritis (OA) grade, medial and lateral joint spaces of the PF joint, and congruence angle were measured. Clinical parameters including the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) were also evaluated. Preoperative and final follow-up values for each procedure were compared in outcome analyses. RESULTS: Mean preoperative HKA and the degree of PF-OA were significantly more severe for patients treated with HCWHTO compared with those treated with OWHTO (p = 0.001, p = 0.0001). Mean postoperative FPHI was significantly decreased with proximalization of the patella in HCWHTO (p = 0.01) but showed no significant change in OWHTO (n.s.). Regarding PF joint congruity after HCWHTO, lateral joint space and congruence angle were significantly improved (p = 0.0001, p = 0.005), while medial joint space was not significantly changed (n.s.). After OWHTO, congruence angle showed no significant difference (n.s.), but medial and lateral joint spaces were significantly decreased (p = 0.0001, p = 0.018). There were no significant differences in KOOS and OKS between the groups (n.s., n.s.). CONCLUSIONS: Although degrees of varus knee and PF-OA were more severe in HCWHTO than those in OWHTO, HCWHTO led to improved PF joint congruity, and its mid-term clinical outcomes were equivalent to those of OWHTO. Therefore, in patients with varus knee combined with PF-OA preoperatively, HCWHTO is a more effective treatment than OWHTO. LEVEL OF EVIDENCE: Therapeutic level III.

Advantages of creation of holes and removal of air in artificial bone for early bone formation when used artificial bone as a gap filler in open wedge high tibial osteotomy.

Recently, many facilities perform open wedge high tibial osteotomy (OWHTO) using artificial bone as a gap filler. However, there are many cases in which artificial bone is used without a clear purpose. We recommend a surgical technique to promote early synostosis between artificial bone and recipient bone due to mechanical support especially in the early stage after OWHTO. At our hospital, beta-tricalcium phosphate (ß-TCP) with 60% porosity is used in OWHTO. Initially, a wedge-shaped block-type ß-TCP, as large as possible, was inserted into the gap. However, from the standpoint of initial mechanical support, we changed the artificial bone size and created intentional holes. Furthermore, we removed air bubbles from ß-TCP. We evaluated the synostosis on the basis of clinical results and diagnostic imaging. As a result of creating holes and removing air from the artificial bone, a trend toward faster synostosis was noted, especially at the early stage. No adverse events such as tibial plateau fracture, lateral cortical fracture, plate and screw failure and correction loss due to reducing the size of the artificial bone occurred, but placement of the artificial bone in contact with cortical bone and surface contact installation with the recipient bone tissue was important. When using artificial bone in OWHTO, holes formation and removal of air from the artificial bone are recommended for faster synostosis between artificial bone and recipient bone in the early stage after surgery. Artificial bone should be used, with attention to its positioning and shape, for efficient mechanical support.

Responsiveness of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) in Japanese patients with high tibial osteotomy.

BACKGROUND: To assess responsiveness of the Japanese Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) in patients undergoing open-wedge HTO to treat knee osteoarthritis and/or osteonecrosis. METHODS: Patients completed a set of questionnaires before HTO surgery (baseline) and 1 year after surgery. The questionnaires comprised the validated Japanese versions of the KOOS, the OKS, and the SF-36v2 and a visual analogue scale (VAS) for local knee pain and general pain. The treating surgeon completed the Japanese Orthopedic Association (JOA) score for osteoarthritic knees. The study included 119 patients aged 64.7 ± 8.3, 116 were followed at 1 year. 90 patients had knee osteoarthritis (OA) solely. 28 patients suffered from both OA and osteonecrosis (ON); one patient had ON only. Responsiveness to change was assessed using the effect size (ES) between the baseline and the 1-year postoperative assessment and standardized response mean. A distribution-based approach was used to determine the minimally detectable change (MDC95) for the KOOS subscales, and the OKS. RESULTS: All instruments demonstrated statistically significant changes between the preoperative assessments and one year after surgery. All changes showed an improvement in score, but the condition-specific measures revealed higher responsiveness than the generic measures. All KOOS subscales, the OKS, the local pain VAS, and the JOA score showed large ESs (ES > 1.24) and SRMs (SRM>1.04). At a 95% confidence level, the respective MDCs were 15.83, 18.94, 15.22, 18.99 and 17.23 for the KOOS-Pain, KOOS-Symptoms, KOOS-ADL, KOOS-Sport/Rec, and KOOS-QOL subscales, respectively. The MDC95 for the OKS was 8.29. CONCLUSIONS: Both, the KOOS and OKS are responsive for use in Japanese-speaking patients with knee osteoarthritis and/or osteonecrosis who are undergoing HTO.

Comparison of results of medial opening-wedge high tibial osteotomy with and without subchondral drilling.

PURPOSE: The purposes of this study were to compare the results of medial opening-wedge high tibial osteotomy (MOWHTO) with and without subchondral drilling and to assess the formation of fibrocartilage at 2 years postoperatively. METHODS: Patients were divided into 2 groups. Thirty knees were treated with osteotomy and subchondral drilling (group 1), and 31 knees were treated with osteotomy alone (group 2). Clinical evaluations were performed by use of Knee Society scores preoperatively and at 2 years postoperatively. For evaluation of cartilage degeneration, the International Cartilage Repair Society grading system was used for arthroscopic grading on initial arthroscopy during high tibial osteotomy. The patients underwent a second-look arthroscopic evaluation of the articular cartilage at the time of removal of the plate, an average of 2 years after the initial osteotomy. For evaluation of formation of fibrocartilage on second-look arthroscopy, the articular cartilage was classified as having either no change from initial surgery (grade I) or white scattering with fibrocartilage, partial coverage with fibrocartilage, or even coverage with fibrocartilage (grade II). In addition, maturation of the appearance of the cartilage was defined. The appearance was considered mature if the chondral defects were evenly covered with fibrocartilage. It was considered immature if there was white scattering or only partial coverage with fibrocartilage. RESULTS: In group 1 the mean Knee Society knee score and function score were 67.3 ± 8.2 points and 66.5 ± 14.3 points, respectively, preoperatively. At 2 years postoperatively, they improved to 91.2 ± 6.4 and 92.8 ± 10.0, respectively (P = .001 and P = .001, respectively). In group 2 the mean Knee Society knee score and function score were 63.7 ± 13.9 points and 66.8 ± 9.1 points, respectively, preoperatively. At 2 years postoperatively, they improved to 92.5 ± 5.3 points and 92.2 ± 8.0 points, respectively (P = .001 and P = .001, respectively). There were no significant differences in the postoperative Knee Society knee score and function score at 2 years' follow-up between the groups (P = .389 and P = .806, respectively). Grade II regeneration was achieved in the medial femoral condyle articular cartilage in 100% of knees in group 1 and 94% of knees in group 2 (P = .492). Maturation of the cartilage was found in the medial femoral condyle articular cartilage in 10% of knees in group 1 and 3% of knees in group 2 (P = .354). There was no significant difference in the formation of fibrocartilage between the groups. CONCLUSIONS: Subchondral drilling had no effect on the outcome at 2 years after MOWHTO. In addition, there was no significant difference in the formation of fibrocartilage with or without subchondral drilling. Therefore subchondral drilling is not necessary after MOWHTO. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Efficacy of periarticular multimodal drug injection after medial opening-wedge high tibial osteotomy: a randomized, controlled study.

PURPOSE: The purpose of this study was to evaluate the efficacy of periarticular multimodal drug injection after medial opening-wedge high tibial osteotomy regarding the postoperative pain level. METHODS: From January 2011 to January 2012, 70 patients underwent medial opening-wedge high tibial osteotomy. Thirty-five patients were randomly assigned to receive no injection (group I), and 35 patients were assigned to receive periarticular multimodal drug injection (group II). These 2 groups were compared regarding the postoperative pain level, frequency of additional nonsteroidal anti-inflammatory drug injections, total amount of patient-controlled analgesia, and number of times that patients pushed the patient-controlled analgesia button at each time interval. Statistical results were based on multivariate analysis of variance and repeated-measures analyses. RESULTS: Multivariate analysis of variance of mean visual analog scale (VAS) scores over the 2-week postoperative period showed statistical significance (P < .001). Repeated-measures analysis yielded a statistically significant difference (P = .001) for the time-by-treatment interaction, showing a clear periarticular multimodal drug injection benefit over time based on VAS scores. In addition, the mean number of times that patients pushed the patient-controlled analgesia button differed significantly between groups over time (P = .01). The VAS scores, frequency of additional nonsteroidal anti-inflammatory drug injections, mean number of times that patients pushed the patient-controlled analgesia button, and mean total amount of fentanyl consumption differed significantly within each group over time (P < .001 for all variables). However, the frequency of additional nonsteroidal anti-inflammatory drug injections and mean total amount of fentanyl consumption did not differ significantly between groups over time (P = .822, P = .529, and P = .282). Opioid- and injection-related complications were not found. CONCLUSIONS: This prospective randomized study shows that intraoperative periarticular multimodal drug injections in patients undergoing medial opening-wedge high tibial osteotomy for unicompartmental osteoarthritis of the knee could result in significant reductions in VAS scores at 2 weeks postoperatively. LEVEL OF EVIDENCE: Level I, high-quality randomized controlled trial with statistically significant differences.

Second-look arthroscopic assessment of cartilage regeneration after medial opening-wedge high tibial osteotomy.

PURPOSE: The purposes of this study were to evaluate regeneration of the articular cartilage after medial opening-wedge high tibial osteotomy for knees with medial-compartment osteoarthritis and to assess the clinical outcome and cartilage regeneration according to the postoperative limb alignment at 2 years postoperatively. METHODS: The study involved 159 knees in 159 patients. For evaluation of cartilage degeneration, the International Cartilage Repair Society grading system was used for arthroscopic grading on initial arthroscopy during high tibial osteotomy. The patients underwent a second-look arthroscopic evaluation of the articular cartilage at the time of removal of the plate, an average of 2 years after the initial osteotomy. For evaluation of cartilage regeneration, the articular cartilage was classified into 2 stages as no regenerative change (grade 1) or white scattering with fibrocartilage, partial coverage with fibrocartilage, or even coverage with fibrocartilage (grade 2) on second-look arthroscopy. Maturation of the cartilage regeneration was defined as even coverage with fibrocartilage. "Immaturation" of the cartilage regeneration was defined as white scattering with fibrocartilage or partial coverage with fibrocartilage. Clinical evaluations were performed by use of Knee Society scores preoperatively and at 2 years postoperatively. We divided the knees into 3 groups according to the postoperative limb alignment. Group A comprised knees with a mechanical tibiofemoral angle of 0° or less. Group B comprised knees with a mechanical tibiofemoral angle greater than 0° and less than 6°. Group C comprised knees with a mechanical tibiofemoral angle of 6° or greater. RESULTS: Grade 2 regeneration was achieved in the medial femoral condyle articular cartilage in 92% of knees and in the medial tibial plateau articular cartilage in 69% of knees. Maturation of the cartilage regeneration was found in the medial femoral condyle articular cartilage in 4% of knees and in the medial tibial plateau articular cartilage in 1% of knees. At follow-up, no significant differences were seen between clinical outcomes and initial cartilage degeneration (P = .338) or cartilage regeneration (P = .699). Regeneration of the medial femoral condyle articular cartilage was found in 75% of group A knees, 95% of group B knees, and 92% of group C knees. Significant differences were seen between cartilage regeneration and clinical outcomes (P = .001), as well as postoperative limb alignment (P = .018). Clinical and regeneration results were better in group B than in groups A and C. CONCLUSIONS: The degenerated cartilage of the medial femoral condyle and medial tibial plateau could be partially or entirely covered by newly regenerated cartilage at 2 years after adequate correction of varus deformity by medial opening-wedge high tibial osteotomy without cartilage regeneration strategies. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Can status of superficial medial collateral ligament proximal tibial attachment predict progression of OA knee?

Objective: This study aims to identify, whether knee OA progression is affected by the sMCL proximal tibial attachment status and probably is the first one trying to identify such association. Methods: 90 OA knees and 80 normal knees were evaluated using radiographs and MRI for severity of OA knee (K-L grade), sMCL length (L), distance of distal tibial attachment of sMCL from tibial articular surface (I), MCL ratio (L/I) and proximal tibial attachment of sMCL, attached or detached. Results: Mean age of the study population was 52.93 ± 19.52 years. 106 were female knees and 59 were male. Status of sMCL proximal tibial attachment had highly statistically significant negative correlation with severity of OA knee (p-value <0.001). The status of sMCL proximal tibial attachment shows statistically significant negative correlation with sMCL distal tibial attachment and significant positive correlation MCL ratio. But there was no significant correlation with sMCL length. Knees with lower MCL ratio (L/I) have significant higher grade of OA knee as they shows statistically significant negative correlation. Conclusion: Detached sMCL proximal tibial attachment is found to be a strong predictor of OA knee progression. Assessing the status of sMCL proximal tibial attachment will not only help the physician identifying medial stability of the knee, but also assist in planning therapy for the knee in question.

Cartilage regeneration and long term survival in medial OA knee patients treated with HTO and OATS.

Background: Osteoarthritis (OA) of the knee, in most instances primarily, affects medial compartment of knee. Combining Osteochondral Autologous Transfer System (OATS) with Medial Open-Wedge High Tibial Osteotomy (MOWHTO) may represent an integrated approach to sustaining long-term knee functionality in OA patients. Materials and methods: From 2009 to 2016, combined OATS and MOWHTO was performed in 66 knees of 63 patients with medial compartment knee OA. Cartilage regeneration was assessed by 2nd look arthroscopy and Knee function was assessed by knee society scoring (KSS) pre-operatively and post-operatively. The survival rate of MOWHTO plus OATS was assessed. Failure is characterized by the need to convert into total knee replacement. Results: The KSS knee score (from 48.3 to 90.4) and function score (from 42.6 to 88.7) showed a statistically significant improvement (p-value of <0.0001) at a mean follow-up period of 9.49 years. Second look arthroscopy done at the time of implant removal showed 100 % cartilage regeneration with even hyaline cartilage regeneration in 49 out of 57 knees assessed and partial regeneration in 8 knees. The Kaplan Meier survivorship analysis was 96.7 % at the mean 9.49 years after surgery. Only 2 patients needed TKA conversion in follow-up. Conclusion: Combining OATs and valgus MOWHTO provides good option to successfully manage patients of OA and varus malalignment. This resulted in significant improvement in knee function, lowering pain intensity, good cartilage regeneration, and a high survivorship rate for 10 years postoperatively.

Fractures around the lateral cortical hinge after a medial opening-wedge high tibial osteotomy: a new classification of lateral hinge fracture.

PURPOSE: The purpose of this study was to determine the frequency of lateral hinge fractures after opening-wedge high tibial osteotomy and investigate the patterns of fracture and their clinical outcome. METHODS: We analyzed 104 knees in 93 patients with a mean age of 68 ± 7 years. Of the knees, 74 were diagnosed as having primary osteoarthritis and 30 with osteonecrosis. The mean follow-up period was 41 months. Lateral hinge fractures were classified as follows: type I, the fracture reaches just proximal to or within the tibiofibular joint; type II, the fracture reaches the distal portion of the proximal tibiofibular joint; and type III, a lateral plateau fracture. A standard postoperative rehabilitation protocol was used for type I fractures, 3 of 5 patients with type II fractures were treated with non-weight bearing, and type III fractures were treated with non-weight bearing until visible callus formation. RESULTS: The Knee Society scores for the knee and for function showed improvement from 49 ± 11 to 91 ± 7.7 points and from 62 ± 13 to 95 ± 8.2 points, respectively. Lateral cortex fractures were observed in 26 knees (25%): 19 type I, 5 type II, and 2 type III. In the type II fracture group, 2 of 5 patients were judged to have a delayed bone union. There were 2 cases of infection (2%) and 1 case of traumatic neuroma (1%) but no instances of implant failure, nonunion, or deep vein thrombosis among our patient cohort. CONCLUSIONS: High tibial osteotomy patients treated with a combination of TomoFix (Synthes, Bettlach, Switzerland) and bone substitute were able to walk with full weight bearing 2 weeks after surgery. No complications were seen in 19 patients with type I fractures. Of 5 patients with type II fractures, 2 had delayed unions with a correction loss of 3° and 7°, respectively. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Case of juxta-articular osteoid osteoma of calcaneus mimicking arthritis.

Juxta-articular osteoid osteoma is a rare disorder that is difficult to correctly diagnose at an early stage. We report a case of osteoid osteoma in the calcaneus that arose near to the talocalcaneal joint. An 18-year-old female presented with symptoms of joint swelling and effusion similar to those of monoarthritis. Conservative treatment proved ineffective in achieving pain relief, and she underwent surgery 6 months later. The lesion was diagnosed by histologic examination, and it resolved after resection of the tumor.

Tibial Condylar Valgus Osteotomy Combined With Medial Open-Wedge Distal Tuberosity Tibial Osteotomy.

Severe varus deformity in osteoarthritic knees is attributed not only to bony deformity but also to intra-articular deformity as a result of medial joint space narrowing with lateral joint space widening (increased joint line convergence angle). In such knees, correction of bony deformity by high tibial osteotomy (HTO) alone may not be capable of restoring physiological joint geometry and biomechanics. Tibial condylar valgus osteotomy (TCVO), an L-shaped osteotomy in the medial tibial condyle, has been proposed to improve articular stability and congruity by elevating the medial tibial joint line and addressing the articular component of the deformity; however, its surgical efficacy for correction of the valgus deformity is limited. Therefore a procedure combining HTO and TCVO can be a reasonable option to achieve restoration of the knee joint physiology in such situations. In our current practice, medial open-wedge distal tuberosity tibial osteotomy (MOW-DTO) has been the procedure of primary option among the HTO procedures to avoid patellofemoral overload which could be an inherent problem in medial open-wedge HTO. In this article, the surgical rationale and the combined procedure of TCVO and MOW-DTO are described.

Clinical outcomes of hybrid closed wedge high tibial osteotomy for advanced osteoarthritis of the knee compared with total knee arthroplasty.

PURPOSE: To evaluate clinical outcomes between hybrid closed wedge high tibial osteotomy (HCWHTO) and total knee arthroplasty (TKA) for advanced medial compartmental osteoarthritis of the knee (advanced knee OA). METHODS: In more than grade 3 OA based on the Kellgren-Lawrence classification, when patients' age was less than 60 years or activity level was more than level 5 based on the UCLA activity score, 22 knees (18 patients) underwent HCWHTO. The other 22 knees (18 patients) that underwent TKA were evaluated retrospectively. Muscle strength was evaluated preoperatively and at 1 year postoperatively. The visual analogue scale (VAS) and Japanese version of the Knee injury and Osteoarthritis Outcome Score (J-KOOS) were used to evaluate clinical outcomes preoperatively and at a mean 66-months follow-up. RESULTS: All postoperative muscle strength measures improved to preoperative equivalent levels in the HCWHTO group; they were significantly higher in the HCWHTO group than in the TKA group (p < .05). The VAS score and total J-KOOS significantly improved in both groups (HCWHTO, p = .001; TKA, p = .040); there were no significant differences in the scores between the groups at the final follow-up. Hybrid closed wedge HTO significantly improved the activities of daily living and sport/recreation scores, whereas TKA did not at the final follow-up. CONCLUSIONS: In advanced knee OA, HCWHTO led to improved muscle strength, and its midterm clinical outcomes were equivalent to those of TKA. To postpone or even to avoid TKA, HCWHTO is considered an appropriate treatment for young and high-activity patients with advanced knee OA. LEVEL OF EVIDENCE: Therapeutic Level III.

Possible involvement of peptidylprolyl isomerase Pin1 in rheumatoid arthritis.

The peptidylprolyl isomerase Pin1 is over-expressed in some human diseases including malignancies and chronic inflammatory diseases, this suggests that it contributes to the constitutive activation of certain intracellular signaling pathways that promote cell proliferation and cell invasion. Here, we investigate the possible role of Pin1 in rheumatoid arthritis (RA). Pin1 expression was immunohistochemically analyzed in synovial tissue (ST) obtained from patients with RA and osteoarthritis (OA). To investigate the correlation between Pin1 and motility and proliferation of synovial cells, Pin1 localization was immunohistochemically compared with matrix metalloproteinase (MMP)-1, MMP-3, and proliferating cell nuclear antigen (PCNA). Double immunofluorescent staining for Pin1 and p65 was performed to determine whether Pin1 is involved in nuclear factor κB (NF-κB) activation in RA-ST. Results showed Pin1 expression was significantly higher in RA-ST than in OA-ST. The expression of MMP-1, MMP-3, and PCNA was also significantly elevated in RA-ST. Double immunofluorescent staining revealed colocalization of Pin1 and p65 in the nuclei of RA-ST. These results suggest that Pin1 may be involved in the pathogenesis of RA binding with p65 to activate the proteins MMP-1, MMP-3, and PCNA. Therefore, Pin1 may play a pivotal role in the pathogenesis of RA.

Cross-cultural adaptation and validation of the Japanese Knee Injury and Osteoarthritis Outcome Score (KOOS).

BACKGROUND: In Japan, only few cross-culturally adapted, internationally used orthopaedic patient self-assessed outcome scores are available. In addition, the high incidence of knee osteoarthritis (OA) suggests the need for validated outcome measures such as the widely used Knee Injury and Osteoarthritis Outcome Score (KOOS) for Japanese populations. The purpose of this study was to provide a cross-culturally adapted and validated KOOS questionnaire for further use in national and international clinical projects involving Japanese patients. METHODS: The Japanese KOOS was developed according to the standard cross-cultural adaptation guidelines. For validation, the KOOS was tested on 58 patients diagnosed with OA. Reliability was tested using the intraclass correlation coefficient (ICC). Internal consistency or homogeneity was assessed using Cronbach's alpha. Construct validity was evaluated by quantifying the correlation between the KOOS and the Japanese OKS and SF-36 questionnaires with Spearmann's correlation coefficients. RESULTS: No major difficulties were encountered during the translation and pre-testing stages. All five KOOS subscales showed adequate reproducibility with ICC values greater than 0.85, high internal consistency with Cronbach's alpha values around 0.90, and high Spearmann's coefficients over 0.50 signifying good correlation between the KOOS subscales and the OKS as well as the majority of the established subscales of the SF-36. No floor and ceiling effects were observed for the five subscales. CONCLUSIONS: Our validated Japanese KOOS is a reliable and stable outcomes measure that provides a valuable basis for national and international clinical projects focusing on patient-based assessments in knee OA.

Medial Closed Wedge Distal Femoral Osteotomy Using a Novel Plate With an Optimal Compression System.

Medial closed wedge distal femoral osteotomy (MCWDFO) has been widely performed for lateral-compartment osteoarthritis since the development of a biplanar osteotomy technique using existing MCWDFO-specific plates. To further improve this system and the technique, we have developed a newly designed MCWDFO plate (TriS-MDFO; Olympus Terumo Biomaterials). The improved shape of the plate consists of a larger head-shaft angle to fit the distal femur after MCWDFO, more distally oriented distal screws to enable longer screw insertion, and a diamond-shaped plate head to avoid interference with the medial patellofemoral ligament. Technically, to overcome the difficulty in inserting proximal screws through the vastus medialis muscle, a cannulated screw system was employed. This system can prevent difficulties in removing the screw due to cross-threading when plate removal is required. Furthermore, we designed a novel compression hook device with a bulb-shaped head to hook on a screw hole to apply a compressive force to the osteotomized site. On the plate side, a characteristic 1.5 mm-thickness stopper is installed to prevent slippage of the hook device. This optimal compression system can minimize the risk of lateral hinge fracture during the compression procedure. These improvements in the TriS-MDFO may increase the ease and safety of MCWDFO.

Opening wedge high tibial osteotomy affects both the lateral patellar tilt and patellar height.

In the current study, we evaluated changes in the patellofemoral joint indices in 49 knees from 39 patients (11 men and 28 women with a median age of 64 years; range 53-79) who had undergone an opening wedge high tibial osteotomy (OWHTO). Osteoarthritis had been diagnosed in 39 knees and osteonecrosis in the other 10 knees in this patient cohort. Radiographs showing anteroposterior and true lateral views of the knee joints while standing, and also skyline views while standing with a 30 degrees flexion, were taken both pre- and postoperatively. Radiographic assessments were then performed using the following five parameters: femorotibial angle (FTA), modified Blackburne-Peel ratio (mBP), tibial slope (TS), lateral patellar tilt (LPT), and lateral patellar shift (LPS). The average LPT decreased significantly from 7.4 degrees + or - 3.7 degrees to 5.2 degrees + or - 3.6 degrees (P < 0.01). Patients treated with a greater than 15 degrees correction showed a significantly bigger change in their LPT than those with corrections of 15 degrees or less. No statistical differences were found between the preoperative (10.2 + or - 4.5%) and postoperative (10.2 + or - 4.7%) LPS measurements. Changes in the radiographic parameters were also observed in the patellofemoral joint after OWHTO. It is unclear to what extent the postoperative patellar shift and tilt affects the long-term clinical outcomes but our current results suggest that OWHTO negatively affects the congruency of the patellofemoral joint and should not exceed a correction of 15 degrees .

Outcome after treatment of osteoarthritis with open-wedge high-tibial osteotomy with a plate: 2-year results of a Japanese cohort study.

PURPOSE: This prospective multicenter study evaluated patient reported outcomes (PROs) in individuals undergoing medial open-wedge high-tibial osteotomy (OWHTO) with plate stabilization compared to conservative care or no treatment. METHODS: One hundred eighteen of 148 patients older than 40 years were elected for OWHTO with plate treatment. Thirty patients declined surgery and were followed as a conservative group. The primary outcome measure was the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 2 years. Secondary measures included Oxford knee score, Western Ontario and McMaster Universities osteoarthritis index, range of motion (ROM), joint space width (JSW), femorotibial angle (FTA), and weight-bearing line ratio (WBLR). RESULTS: Patient enrollment and baseline characteristics were heterogeneously distributed and led to group characteristics that were not comparable. Therefore, the comparison of the KOOS between the groups showing no differences must be treated with caution. In the OWHTO plate group, all PROs and the ROM significantly improved between baseline and 2-year follow-up. JSW remained stable in the OWHTO group. The FTA and WBLR significantly changed from a mean of 179.3 (95% confidence interval (CI): 178.7, 179.9) to 169.8 (95% CI: 169.2, 170.5) and from 23.1 (95% CI: 20.7, 25.5) to 62.4 (95% CI 59.0, 65.8), respectively. Treatment failure with conversion to total knee arthroplasty occurred in 1% of the OWHTO group; and in the conservative group, 10% converted to HTO or knee arthroplasty. CONCLUSIONS: OWHTO with plate leads to significant improvement of PROs and function 2 years after intervention and demonstrates reliable mechanical axis correction with subsequent shift of weight-bearing.

Medial opening wedge high tibial osteotomy with early full weight bearing.

PURPOSE: We performed clinical and radiographic evaluation of patients with medial compartment osteoarthritis of the knee who had undergone treatment with opening wedge high tibial osteotomy (OWHTO) followed by early full weight bearing. OWHTO procedures were performed by use of TomoFix (Synthes, Bettlach, Switzerland) and bone substitute materials. METHODS: OWHTO was performed in 57 knees in 52 patients with a mean age of 69 years (range, 54 to 82 years) at the time of operation. The diagnosis was primary osteoarthritis in 34 knees in 29 patients and osteonecrosis in a further 23 knees in 23 patients. We established an early weight-bearing exercise program during which these patients were permitted partial weight-bearing exercise 1 week after their osteotomy procedure. All patients performed full weight-bearing exercises at 2 weeks after surgery. The mean follow-up period was 40 months (range, 24 to 62 months). RESULTS: The American Knee Society Score and Function Score showed significant improvement from 50.9 +/- 12.3 to 91.7 +/- 6.9 points and 59.3 +/- 13.1 to 94.1 +/- 8.8 points, respectively. Before surgery, the mean femorotibial angle during standing was 181.3 degrees +/- 2.4 degrees (1.3 degrees anatomic varus), but it measured 169.6 degrees +/- 2.3 degrees (10.4 degrees valgus) at the time of follow-up. There were no instances of nonunion or implant failure in any of our patients. CONCLUSIONS: We have shown that an early weight-bearing exercise program enables full weight bearing at 2 weeks after OWHTO with TomoFix and artificial bone wedges. Overall, this combination was a highly successful course of treatment for correcting knee malalignment in patients with medial compartment osteoarthritis. LEVEL OF EVIDENCE: Level IV, therapeutic case series.