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.

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.

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.

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.

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.

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.

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.

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.

Distal Tibial Tuberosity Arc Osteotomy in Open-Wedge Proximal Tibial Osteotomy to Prevent Patella Infra.

Open-wedge high tibial osteotomy is considered to be an effective surgical intervention for medial compartmental knee osteoarthritis. However, patella infra, which has been reported to be a result of tuberosity distalization after open-wedge high tibial osteotomy, changes the native patellofemoral biomechanics. This could raise abnormal patellofemoral contact stresses, which might be the trigger of patellofemoral arthrosis. To minimize the reduction in patellar height, we have developed a technique called open-wedge distal tuberosity tibial osteotomy. The benefits of this technique include increased bone-to-bone contact of the distal tuberosity cut surface after correction by cutting an arc osteotomy around the hinge position, which is the center of rotation. This technique also provides cortical support at the anterior osteotomy site without additional bone defect and, therefore, may be advantageous against weight-bearing stress on the osteotomy site. In all, open-wedge distal tuberosity tibial osteotomy could potentially be a unique open-wedge osteotomy that eliminates the risk for postoperative patellofemoral osteoarthritis and also could theoretically encourage rapid healing of the osteotomy, which could lead to early return to full physical activity.

Low-Intensity Pulsed Ultrasound Prevents Development of Bisphosphonate-Related Osteonecrosis of the Jaw-Like Pathophysiology in a Rat Model.

We developed a rat model of bisphosphonate-related osteonecrosis of the jaw (BRONJ) by removing a maxillary molar tooth (M1) from ovariectomized rats after treatment with alendronate. To mimic periodontitis, some of the rats were administered Porphyromonas gingivalis (p. gingivalis) at the M1 site every 2 to 3 d for 2 wk. Rats pretreated with alendronate plus p. gingivalis showed delayed healing of socket epithelia, periosteal reaction of alveolar bone formation and lower bone mineral density in the alveolus above adjacent M2 teeth. These abnormalities were prevented by tooth socket exposure to 20 min/d low-intensity pulsed ultrasound (LIPUS), which restored diminished expression of RANKL, Bcl-2, IL-6, Hsp70, NF-κB and TNF-α messenger ribonucleic acids in remote bone marrow, suggesting LIPUS prevented development of BRONJ-like pathophysiology in rat by inducing systemic responses for regeneration, in addition to accelerating local healing. Non-invasive treatment by LIPUS, as well as low-level laser therapy, may be useful for medication-related osteonecrosis of the jaw patients.

Comparison of torsional changes in the tibia following a lateral closed or medial open wedge high tibial osteotomy.

OBJECTIVE: The aim of this study is to evaluate, by computed tomography (CT), whether different torsional changes occur in the tibia following a lateral closed wedge high tibial osteotomy (CWHTO) versus a medial open wedge high tibial osteotomy (OWHTO) procedure. It was hypothesized that the distal fragment of the tibia would show greater internal rotation after CWHTO. METHODS: Thirty knees from 25 patients who underwent HTO were enrolled. Fifteen knees of 14 patients who underwent CWHTO and 15 knees of 11 patients who received OWHTO were match-paired. CT scans were taken before and three weeks after surgery. Rotational changes in the distal fragment of the tibia were assessed by measuring the tibial torsion angle (TTA). RESULTS: The mean TTA in the CWHTO group pre-operatively and postoperatively was +23.9°â€¯±â€¯7.8° and + 18.2°â€¯±â€¯7.0°, respectively. Internal rotation of the distal fragment of the tibia after CWHTO was -5.7 ±â€¯3.3° (P < 0.001). In the OWHTO group, the mean TTA pre-operatively and postoperatively was +27.9°â€¯±â€¯6.9° and + 26.8 ±â€¯7.7°, respectively, with no significant change in torsion observed (P > 0.05). CONCLUSIONS: The distal fragment of the tibia rotated internally after CWHTO but not after OWHTO. LEVEL OF EVIDENCE: Level III: case-control study.

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.

Primary stability of different plate positions and the role of bone substitute in open wedge high tibial osteotomy.

BACKGROUND: The purpose of this study was to compare the mechanical fixation strengths of anteromedial and medial plate positions in osteotomy, and clarify the effects of bone substitute placement into the osteotomy site. METHODS: Twenty-eight sawbone tibia models were used. Four different models were prepared: Group A, the osteotomy site was open and the plate position was anteromedial; Group B, bone substitutes were inserted into the osteotomy site and the plate position was anteromedial; Group C, the osteotomy site was open and the plate position was medial; and Group D, bone substitutes were inserted into the osteotomy site and the plate position was medial. The loading condition ranged from 0 to 800N and one hertz cycles were applied. Changes of the tibial posterior slope angle (TPS), stress on the plate and lateral hinge were measured. RESULTS: The changes in the TPS and the stress on the plate were significantly larger in Group A than in Group C. These were significantly larger in Group A than in Group B, and in Group C than in Group D. There was no significant difference between Group B and Group D, and no significant difference between knee flexion angles of 0° and 10°. Stress on the lateral hinge was significantly smaller when bone substitute was used. CONCLUSIONS: A medial plate position was biomechanically superior to an anteromedial position if bone substitute was not used. Bone substitute distributed the stress concentration around the osteotomy gap and prevented an increase in TPS angle regardless of the plate position.

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.

In vivo vascularization of cell sheets provided better long-term tissue survival than injection of cell suspension.

Cell sheets have shown a remarkable ability for repairing damaged myocardium in clinical and preclinical studies. Although they demonstrate a high degree of viability as engrafted cells in vivo, the reason behind their survivability is unclear. In this study, the survival and vascularization of rat cardiac cell sheets transplanted in the subcutaneous tissue of athymic rats were investigated temporally. The cell sheets showed significantly higher survival than cell suspensions for up to 12 months, using an in vivo bioluminescence imaging system to detect luciferase-positive transplanted cells. Terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay also showed a smaller number of apoptotic cells in the cell sheets than in the cell suspensions at 1 day. Rapid vascular formation and maturation were observed inside the cell sheets using an in vivo imaging system. Leaky vessels appeared at 6 h, red blood cells flowing through functional vessels appeared at 12 h, and morphologically matured vessels appeared at 7 days. In addition, immunostaining of cell sheets with nerve/glial antigen-2 (NG2) showed that vessel maturity increased over time. Interestingly, these results correlated with the dynamics of cell sheet mRNA expression. Genes related to endothelial cells (ECs) proliferation, migration and vessel sprouting were highly expressed within 1 day, and genes related to pericyte recruitment and vessel maturation were highly expressed at 3 days or later. This suggested that the cell sheets could secrete appropriate angiogenic factors in a timely way after transplantation, and this ability might be a key reason for their high survival. Copyright © 2014 John Wiley & Sons, Ltd.

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.

A novel closed-wedge high tibial osteotomy procedure to treat osteoarthritis of the knee: hybrid technique and rehabilitation measures.

High tibial valgus osteotomy (HTO) is an established treatment for medial-compartment osteoarthritis of the knee. We have combined medial open and lateral closed-wedge HTO (hybrid closed-wedge HTO) to overcome the limitations of traditional closed-wedge HTO. Our new hybrid procedure has the following advantages: (1) the bone block removed is smaller in size; (2) the procedure yields optimal geometric characteristics for bone healing; (3) there is no step-off at the lateral osteotomy site; (4) the lateral cortex of the proximal and distal fragments is attached firmly by the oblique osteotomy; and (5) early full weight-bearing walking is possible. This procedure is effective in treating medial-compartment osteoarthritis accompanied by patellofemoral osteoarthritis. The indications for this procedure include a willingness and ability to comply with the postoperative rehabilitation program; a diagnosis of either medial-compartment osteoarthritis or complicated patellofemoral osteoarthritis; and preferably, an age of 70 years or younger, although this is not a strict constraint. Patients are permitted to stand using both legs on the day after surgery and walk with full weight bearing within 2 weeks of undergoing our novel HTO procedure. We describe the details of this surgical technique and the postoperative rehabilitation program for the patients who undergo this treatment.

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.