Age does not affect the clinical and radiological outcomes after open-wedge high tibial osteotomy

Factors Associated With Patient Satisfaction After Opening-Wedge High Tibial Osteotomy

Background:

Opening-wedge high tibial osteotomy (OWHTO) is expected to result in higher patient satisfaction compared with knee arthroplasty due to joint preservation. However, patient satisfaction rates as well as factors associated with satisfaction after OWHTO remain unclear.

Purpose:

To evaluate patient subjective satisfaction after OWHTO and determine factors associated with patient satisfaction after OWHTO.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study enrolled 123 patients (123 knees) who underwent unilateral OWHTO. Clinical parameters, including range of motion (ROM), visual analog scale (VAS) score for pain, Knee injury and Osteoarthritis Outcome Score (KOOS), weightbearing line ratio (WBLR), and medial proximal tibial angle (MPTA), were assessed before surgery and at the final follow-up at a minimum of 2 years. Patient satisfaction was evaluated using a 5-point scale regarding (1) surgery, (2) pain relief, (3) knee mobility, (4) daily living function, and (5) lower extremity alignment. The mean overall satisfaction scores for the 5 questions were calculated, and the sample was divided into 2 main groups (satisfied or unsatisfied). Preoperative characteristics, physical activity level, patient expectations for surgery, ROM, and KOOS were compared between the groups. Cartilage regeneration was assessed at the time of plate removal, and WBLR and MPTA were also assessed. Factors associated with patient satisfaction were analyzed using multivariable logistic regression analysis.

Results:

The mean ± SD follow-up was 54.6 ± 20.6 months. The mean WBLR significantly changed from 20.7% ± 11.8% preoperatively to 66.9% ± 10.2% at the final follow-up, and all KOOS subscale scores significantly improved after surgery. Of the 123 patients, 109 (88.6%) were graded as satisfied. Factors associated with patient satisfaction were expectations met (odds ratio, 17.4; P = .026), better postoperative KOOS Pain score (odds ratio, 1.30; P = .001), and better postoperative KOOS Activities of Daily Living score (odds ratio, 1.36; P = .002).

Conclusion:

OWHTO is an effective treatment in terms of subjective satisfactory outcomes. Patient expectations for surgery have a significant effect on patient satisfaction. Surgeons should consider patient expectations before OWHTO and provide patient education to improve patient satisfaction.

Outcomes of Medial Meniscal Posterior Root Repair During Proximal Tibial Osteotomy: Is Root Repair Beneficial?

PURPOSE

To compare the clinical and radiologic outcomes and arthroscopic findings of proximal tibial osteotomy (PTO) alone versus PTO combined with medial meniscal posterior root repair (MMPRR).

METHODS

Between October 2010 and September 2016, patients who underwent PTO and second-look arthroscopy at a minimum of 24 months postoperatively were reviewed. Patients were divided into group I (isolated PTO), group P (PTO with MMPRR using the pull-out technique), and group F (PTO and MMPRR using the side-to-side repair method). The subjective knee scores were assessed. Radiologic evaluation was based on the Kellgren-Lawrence grade. Healing of medial meniscal posterior root tears (good/loose/scar tissue/failed) and cartilage regeneration (excellent/good/poor) were assessed by arthroscopic examination.

RESULTS

Mean clinical follow-up duration of group I (n = 22), P (n = 25), and F (n = 24) was 28.5 ± 5.7, 27.9 ± 6.2, and 26.3 ± 5.3 months, respectively. At final follow-up, Lysholm score, International Knee Documentation Committee subjective score, and Tegner activity scale significantly improved in all groups (P < .001), and subjective scores did not differ among the groups. The Kellgren-Lawrence grade progression showed no significant differences among 3 groups (P = .461). Good healing of medial meniscal posterior root tears was found in 24% and 12.5% of patients in groups P and F, respectively, and 0 in group I; there were significant differences between groups I and P (P < .001) and groups I and F (P < .001). Excellent cartilage regeneration in the medial femoral condyle and medial tibial plateau was found in 13.6% and 9.1% in group I, 24% and 12% in group P, and 16.7% and 8.3% in group F, respectively, without significant differences.

CONCLUSIONS

Concurrent MMPRR during PTO appears to improve the arthroscopic appearance (healing of MMRPTs and cartilage regeneration) during second-look arthroscopy. However, concurrent MMPRR does not significantly improve clinical and radiologic outcomes at short-term follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Plate removal without loss of correction after open-wedge high tibial osteotomy is possible when posterior cortex bone union reaches osteotomy gap center even in incompletely filled gaps

PURPOSE

The study aimed to evaluate the optimal timing for plate removal after open-wedge high tibial osteotomy (OWHTO) without loss of correction and to investigate risk factors for loss of correction after plate removal. The study presents the hypothesis that plate removal without loss of correction was possible when gap filling reached zone 2 (25-50%) on anteroposterior radiographs.

METHODS

Ninety-one patients (101 knees) who underwent OWHTO using the TomoFix^® plate were enrolled. Plate removal was performed at an average 16.4 ± 5.4 months after OWHTO. Clinical evaluation included plate-related symptoms, the Japanese Orthopedic Association Knee Score (JOA score), and Oxford Knee Score (OKS). Radiological outcomes, including the hip-knee-ankle angle (HKA), weight-bearing line ratio (WBLR), medial proximal tibial angle (MPTA), and posterior tibial slope (PTS), were evaluated preoperatively, at plate removal and at 1 year after plate removal. Computed tomography (CT) was performed at plate removal to evaluate the flange bone union, progression rates of gap filling, and posterior cortex bone union. In addition, the risk factors for loss of correction after plate removal were evaluated.

RESULTS

At plate removal, 63 (62.4%) knees had plate-related symptoms (mild, 56 knees; moderate, 7 knees; severe, 0). After plate removal, the JOA score did not change, whereas OKS further improved; six knees developed loss of correction. On CT evaluation at plate removal, the flange bone union was achieved in all cases; the progression rates of gap filling and posterior cortex bone union were 47.0% ± 16.6% and 62.8% ± 16.5%, respectively. A posterior cortex union rate of < 43.3% was the only predictor for loss of correction after plate removal (odds ratio: 1.38, P < 0.01).

CONCLUSIONS

Plate removal without loss of correction after OWHTO was possible when bone union of the posterior cortex reached the center of the osteotomy gap even in incompletely filled gaps.

LEVEL OF EVIDENCE

Therapeutic case series, Level IV.

Joint line convergence angle predicts outliers of coronal alignment in navigated open-wedge high tibial osteotomy

INTRODUCTION

Using a navigation system in open-wedge high tibial osteotomy (OWHTO) has higher accuracy than using the conventional method. However, unintentional over- and under-correction still exist. This study aimed to compare various factors related to over- and under-correction and to assess their predictive factors in the preoperative radiographs.

MATERIALS AND METHODS

This study involved 96 knees. The difference in the hip-knee-ankle angle (HKA) between the intraoperative navigation system and postoperative radiograph was termed navigation correction loss (NCL). Knees with absolute values of NCL (|NCL|) ≦ 1.5° and |NCL| > 1.5° were categorised into acceptable (n = 46) and outlier (n = 50) groups, respectively. The differences in joint line convergence angle (JLCA) between varus and valgus radiographs, varus JLCA, valgus JLCA, standing JLCA and standing HKA were compared between the two groups. Clinical results were evaluated using the American Knee Society (AKS) scores.

RESULTS

The mean intraoperative HKA in the navigation system was - 3.8 ± 1.8°, and that in the postoperative standing radiograph was - 4.2 ± 2.5° (p = 0.033). Preoperative varus, valgus and standing JLCA were higher in the outlier group (p = 0.018, p = 0.020 and p = 0.001, respectively). Logistic regression analyses for preoperative factors of |NCL| ≦ 1.5° showed that standing JLCA was a determining factor, with an odds ratio of 1.334 (confidence interval was 1.087-1.637, p = 0.006). AKS score was higher in the acceptable group (p = 0.040) postoperatively.

CONCLUSIONS

Higher preoperative standing JLCA was the predictive factor of |NCL| > 1.5°. This factor reduced the rates of under- and over-correction and resulted in better AKS score in OWHTO.

Total knee arthroplasty in achondroplasia without deformity correction: A case report with 11 years' follow-up

Knee osteoarthritis in patients with achondroplasia is rare. Bowleg deformity is typical but corrective surgery is limited. Thus, primary total knee arthroplasty (TKA) might be challenging due to the particular anatomy. We report on a patient with 11 year's follow-up after a TKA performed maintaining bowleg alignment, using a posterior stabilized, fixed-bearing design. Sequential X-rays showed radiolucencies on the femoral component within two years postoperatively, slightly increasing over time but stable at last follow-up. The Oxford Knee Score showed an excellent result at 11 years. Despite the peculiarities of a case report, TKA without concomitant osteotomies might be an option for such patients. Nevertheless, a thorough discussion about pros and cons is paramount.

Tibial condylar valgus osteotomy - indications and technique

PURPOSE

To describe the indications for, and surgical technique of, tibial condylar valgus osteotomy (TCVO).

INDICATIONS

TCVO is commonly performed in patients with middle-to-end-stage medial unicompartmental osteoarthritis. Among the most important TCVO indication criteria are the types of tibial plateau shape. The convex-type (also called "pagoda-type"), with over a 5° joint line convergence angle on the standing X-ray, meets the indication criteria for TCVO.

SURGICAL TECHNIQUE

An L-shaped osteotomy is performed from the medial side of the proximal tibia to the lateral beak of the intercondylar eminence. The apex of the L-shaped osteotomy line is on the medial border of the patellar tendon insertion. Surgeons should note the direction of the chisel (during the osteotomy) to the intercondylar eminence following fluoroscopic guidance. The posterior cortical bone is cut under a lateral view observation, and the crossed-leg position is adopted to prevent injury to the popliteal blood vessels. The spreader should be positioned at the posterior cortical bone to avoid increasing the tibial slope. The locking plate reliably stabilizes the osteotomy and helps shorten the period of postoperative rehabilitation.

CONCLUSIONS

TCVO adjusts varus deformity alongside joint congruity. Accurate identification of indications and a detailed surgical plan would ensure effective correction and proper alignment. Additional osteotomies are recommended in case of under-correction of the varus limb deformity. TCVO is an effective intervention in patients with advanced knee osteoarthritis and lateral joint laxity with the pagoda-type tibial plateau shape.

Open-wedge high tibial osteotomy for spontaneous osteonecrosis of the medial tibial plateau shows excellent clinical outcomes

PurposeThere have been few reports on medial tibial plateau osteonecrosis, and treatment options remain controversial. This study aimed to evaluate the clinical outcomes of open-wedge high tibial osteotomy (OWHTO) for osteonecrosis of the medal tibial plateau.MethodsPatients who underwent OWHTO for spontaneous osteonecrosis of the medial tibial plateau from November 2013 to September 2017 at our institution and followed up for at least 2 years after surgery were included in this study. Patients with history of alcohol abuse and corticosteroid therapy were excluded. Clinical evaluations, including the Japanese Orthopedic Association (JOA) score and the Oxford Knee Score (OKS), were measured preoperatively and at the final followup. Radiological evaluations included the weight-bearing line ratio (WBLR) and the lesion stage of the osteonecrosis according to Carpintero, Lotke, and the modified Ficat and Arlet classification. The area and size of the necrosis and the type of meniscus tear were also evaluated using preoperative magnetic resonance imaging (MRI). Additionally, cartilage regeneration was evaluated at plate removal.ResultsTwelve cases that underwent OWHTO for spontaneous osteonecrosis of the medial tibial plateau were enrolled. Eleven cases had isolated medial tibial osteonecrosis, and one case had both femoral and tibial osteonecrosis. The mean age was 59.6 ± 9.0 years, and the mean follow-up period was 41.8 ± 17.6 months.The WBLR significantly changed after OWHTO (24.0% ± 10.7% to 66.3% ± 6.7%, P < 0.001), and all clinical scores significantly improved after surgery: JOA score 63.3 ±12.3 to 95.0 ± 4.8, OKS 27.4 ± 7.8 to 42.6 ± 4.1, both 0.001. There were no adverse complications requiring additional surgery. The MRI findings revealed that all cases had meniscal lesions in addition to a necrotic lesion. Second-look arthroscopy was performed at plate removal in 11 cases, and cartilage regeneration was observed in 9/11 cases (81.8%).ConclusionsThis study's results demonstrated that OWHTO is an effective procedure for spontaneous osteonecrosis of the medial tibial plateau with respect to subjective and objective clinical outcomes.

Health-Related Quality of Life - an Underestimated Factor to Evaluate the Treatment Success after Open Wedge HTO Surgery: Prospective 6-Years Follow-Up

BACKGROUND

The subjective health related quality of life in patients with degenerative joint diseases is an important variable to evaluate the treatment outcome. In this study, mid-term results of open wedge HTO were analysed and compared to the subjective quality of life (SF 36) of the general population. Furthermore, the relationships of preoperative assessed subscales of the health-related quality of life (SF 36) and the conversion to knee arthroplasty were analysed.

METHODS

The cohort consisted of 120 patients who were prospectively followed-up after open wedge HTO. At five follow-up points of time, patients were examined and asked about their subjective, health-related quality of life using the SF 36 score.

RESULTS

104 patients were included and evaluated until the last follow-up (mean: 81.2 ± 11.3 months after open wedge HTO; follow-up rate: 86.7%). Six years after open wedge HTO, similar values in several psychologic subscales of the SF 36 (BP, GH, V, MH) and the mental health component summary score (MCS) compared to the general population were found. The physical health component summary score (PCS) showed a significant improvement relative to the preoperative values. Nine out of 104 patients (8.7%) received a knee arthroplasty (50.1 ± 25.0 months). Low preoperative values of the subscales "physical functioning" (PF) and "bodily pain" (BP) were identified as risk factors in terms of conversion to a total knee arthroplasty.

CONCLUSIONS

Patients with medial unicompartimental knee osteoarthrosis treated with open wedge HTO showed very good results. The health-related quality of life was nearly as high as in the general population. Patients with preoperative low physical function and high pain values have a higher risk to have a conversion to knee arthroplasty. Surgeons should be aware of these factors if an open wedge HTO is considered.

High tibial osteotomy results in improved frontal plane knee moments, gait patterns and patient-reported outcomes

PURPOSE

The purpose of this study was to quantify changes in knee loading in the three clinical planes, compensatory gait adaptations and patient-reported outcome measures (PROMS) resulting from opening wedge high tibial osteotomy (HTO).

METHODS

Gait analysis was performed on 18 participants (19 knees) with medial osteoarthritis (OA) and varus alignment pre- and post-HTO, along with 18 controls, to calculate temporal, kinematic and kinetic measures. Oxford Knee Score, Knee Outcome Survey and visual analogue pain scores were collected. Paired and independent sample tests identified changes following surgery and deviations from controls.

RESULTS

HTO restored frontal and transverse plane knee joint loading to that of the control group, while reductions remained in the sagittal plane. Elevated frontal plane trunk sway (p = 0.031) and reduced gait speed (p = 0.042), adopted as compensatory gait changes pre-HTO, were corrected by the surgery. PROMs significantly improved (p ≤ 0.002). Centre of pressure (COP) was lateralised relative to the knee post-HTO (p < 0.001). Energy absorbed in the sagittal plane significantly increased post-HTO (p = 0.007), whilst work done in the transverse plane reduced (p ≤ 0.008). Pre-operative gait deviations from the control group that were retained post-HTO included smaller sagittal (p = 0.003) knee range of motion during gait, greater stance duration (p = 0.008) and altered COP location (anterior to the knee) in early stance (p = 0.025).

CONCLUSIONS

HTO surgery restored frontal and transverse plane knee loading to normal levels and improved PROMs. Gait adaptations known to reduce knee loading employed pre-HTO were not retained post-HTO. Some gait features were found to differ between post-HTO subjects and controls.

LEVEL OF EVIDENCE

II.

High tibial osteotomy solely for the purpose of return to lifelong sporting activities among elderly patients: A case series study

Knee osteoarthritis (KOA) is a common joint disease among older individuals, associated with increased mortality rates. The current study was conducted to examine whether open wedge high tibial osteotomy (OWHTO) is an effective treatment for elderly patients with a desire to return to sporting activities (RTS) who do not report inconvenience or pain in activities of daily living. We examined a case series of 9 KOA patients (12 knees) aged 50 or above with a desire for RTS, who underwent HTO. We assessed patients before surgery and 2 years after surgery to evaluate surgical outcomes and RTS. The results revealed that patients’ average Japanese Orthopaedic Association score was significantly improved at 2 years after surgery (97.5 ± 4.5), compared with the preoperative score (87.9 ± 7.2; p = 0.008). In addition, the average Tegner activity level score was significantly improved at 2-year follow-up (5.8 ± 1.1) compared with the preoperative score (2.8 ± 1.1; p < 0.001). Eight of nine cases except a marathon runner returned to pre-symptom sporting performance levels. Overall, the current findings suggest that OWHTO provides an appropriate treatment for older KOA patients with a desire for RTS.

Comparison of Clinical and Radiologic Outcomes Between Normal and Overcorrected Medial Proximal Tibial Angle Groups After Open-Wedge High Tibial Osteotomy

PURPOSE

To evaluate whether the overcorrected medial proximal tibial angle (MPTA) affects the clinical outcomes after open-wedge high tibial osteotomy (OWHTO) and to assess the correlation between knee joint line obliquity (KJLO) changes and the compensatory changes in the hip and ankle joints.

METHODS

Consecutive patients who underwent OWHTO from July 2006 to August 2015 were included. Exclusion criteria were bilateral OWHTO and follow-up of <2 years. The patients were retrospectively divided into 2 groups according to postoperative MPTA; a normal group (MPTA <95°) and an overcorrected MPTA group (MPTA ≥95°). The groups were compared with respect to the clinical and radiologic outcomes after OWHTO. Clinical parameters, including Japanese Orthopedic Association (JOA) score, Oxford Knee Score (OKS), and Knee Injury and Osteoarthritis Outcome Score (KOOS), were evaluated. Radiologic outcomes, including the hip-knee-ankle angle (HKA), joint line convergence angle (JLCA), MPTA, KJLO, ankle joint line obliquity (AJLO), and hip abduction angle (HAA), were evaluated preoperatively and at the final follow-up.

RESULTS

Ninety-four patients (normal group; n = 52, overcorrected group; n = 42) were included in this study. After OWTHO, the mean increases in HKA and MPTA were 11.0° ± 3.2° and 10.4° ± 2.7°, respectively, whereas the change in KJLO was only 3.7° ± 2.9°. The mean AJLO (4.3 ± 3.9 to -1.3 ± 3.3, P < .001) and HAA (3.7 ± 2.5 to -1.1 ± 2.3, P < .001) significantly decreased after OWHTO. The mean postoperative MPTA in the overcorrected group was 96.9° ± 1.5°, whereas the mean postoperative KJLO was only 3.1° ± 2.0°. No significant differences were noted in all clinical scores between the groups at the final follow-up.

CONCLUSIONS

A certain degree of overcorrected MPTA (≥95°) did not affect the clinical outcomes after OWHTO because of compensatory changes in the hip and ankle joints.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

Patient reported outcomes after high tibial osteotomy show comparable results at different ages in the mid-term to long-term follow-up

BACKGROUND

Few studies have evaluated the impact of age on patient-reported outcomes in the long-term follow-up after high tibial valgus osteotomy (HTO). The purpose of this study is to assess the association between age at surgery and patient-reported clinical outcomes in the mid-term to long-term follow-up of HTO.

MATERIALS AND METHODS

We mailed the 2011 Knee Society score (KSS) questionnaires to 234 consecutive patients (295 knees) who had undergone closing-wedge HTO, and 158 patients (202 knees, 68.5%) returned a completed questionnaire. The cohort was divided into two groups depending on the age at the time of surgery, and pairs matched the follow-up period and sex was created. The mean follow-up period was approximately 12 years. KSS scores at the final follow-up were compared between two groups using the Student t test and chi-square test, and the survival rates were calculated using Kaplan-Meier survival curves.

RESULTS

The symptom, satisfaction, and expectation scores were not significantly different between the ≤64-year-old patients and ≥65-year-old patients. The functional activities score was significantly lower in older patients than in younger patients. The overall survival rates of HTO were 99.1 ± 0.4% at 5 years, 94.4 ± 1.2% at 10 years, and 84.6 ± 2.7% at 15 years. There was no significant difference in the survival rate after HTO between the two groups divided by the age (p = 0.602).

CONCLUSIONS

Pain relief and satisfaction after HTO in older patients were comparable to those in younger patients in the mid-term to long-term follow-up, although the functional activity was affected by age.

Editorial Commentary: Does Patellofemoral Degenerative Progression After Open-Wedge High Tibial Osteotomy Adversely Affect Clinical Outcomes?

Open-wedge high tibial osteotomy causes deterioration of the patellofemoral cartilage status. However, whether patellofemoral degenerative progression adversely affects clinical outcomes remains unclear, thereby necessitating a comprehensive long-term follow-up study.

Predictive Factors for Patellofemoral Degenerative Progression After Opening-Wedge High Tibial Osteotomy

PURPOSE

To identify risk factors for patellofemoral degenerative progression after opening-wedge high tibial osteotomy (HTO) and to investigate the effect of patellofemoral degeneration on the patellofemoral specific patient-reported outcomes.

METHODS

Between March 2010 and June 2016, 94 knees (86 patients) underwent hardware removal with second-look arthroscopy at 21.4 months after opening-wedge HTO with first-look arthroscopy (mean follow-up duration, 49.8 months). Predictive factors for patellofemoral degeneration, including demographics, preoperative and postoperative mechanical axis (MA) of the lower limb (positive and negative MA indicating varus and valgus, respectively), tibial slope, and modified Blackburne-Peel ratio, were evaluated. Patients were divided into the progression and nonprogression groups according to their patellofemoral degenerative progression from first to second arthroscopy. Clinical outcomes, including the Kujala score and Knee Injury and Osteoarthritis Outcome Score, and radiographic outcomes were compared between the 2 groups.

RESULTS

Postoperative MA (adjusted odd ratio, 0.62; P < .001) was the most significant predictive factor for progressive change in the patellofemoral joint (R_n² = 0.31). Twenty-eight knees (30%) showed patellofemoral degenerative progression. Mean postoperative Kujala score (progression group 60.5 vs nonprogression group, 72.3; P = .005) and Knee Injury and Osteoarthritis Outcome Score scales (except for the symptom subscale) were lower in the progression group. Postoperative MA was significantly more corrected in the progression group (progression group -5.1° ± 2.7° vs nonprogression group -2.4° ± 2.3°; P < .001).

CONCLUSIONS

Postoperative MA, which might be related to overcorrection, is correlated with patellofemoral degenerative progression after opening-wedge HTO. Patients with patellofemoral degenerative progression showed inferior patient-reported outcomes.

LEVEL OF EVIDENCE

Level IV, case series with subgroup analysis.

Large opening gaps, unstable hinge fractures, and osteotomy line below the safe zone cause delayed bone healing after open-wedge high tibial osteotomy

PURPOSE

To evaluate bone formation in the osteotomy gap after open-wedge high tibial osteotomy (OWHTO), including after plate removal, and to investigate risk factors for delayed bone healing.

METHODS

Ninety-three patients (102 knees) who underwent OWHTO without bone grafting were enrolled. The osteotomy gap was divided into the lateral hinge and the four zones on anteroposterior radiographs, and we defined the zone in which trabecular bone continuity could be observed as gap filling. Bone formation in the osteotomy gap was evaluated according to this definition at 3, 6, and 12 months postoperatively; at plate removal; and at the final follow-up (mean, 62.3 ± 30.2 months). We also investigated the risk factors for delayed bone healing.

RESULTS

The lateral hinge united at 3 months postoperatively in 92 knees (90.2%). At 1 year postoperatively, 98 knees (96.1%) reached zone 1 and 92 knees (90.2%) reached zone 2. At plate removal, gap filling reached zone 2 in all cases and progressed further without loss of correction after plate removal. Opening width over 13.0 mm [odds ratio (OR): 1.61, P = 0.02], Takeuchi's classification type II lateral hinge fracture (OR: 20.4, P < 0.01), and osteotomy line below the safe zone (OR: 8.98, P < 0.01) significantly delayed bone formation after OWHTO.

CONCLUSIONS

Gap filling progressed from lateral to medial after OWHTO without bone grafting and progressed further after plate removal. Large opening gaps, unstable hinge fractures, and osteotomy line below the safe zone cause delayed bone healing after OWHTO.

Large deformity correction in medial open-wedge high tibial osteotomy may cause degeneration of patellofemoral cartilage: A retrospective study

To evaluate retrospectively any association between the degree of deformity correction by medial open-wedge high tibial osteotomy (HTO) and patellofemoral joint degeneration. We hypothesized that development of patellofemoral joint degeneration depended on the degree of intraoperative deformity correction.Fifty-seven patients who underwent medial open-wedge HTO for treatment of osteoarthritis in one knee were included in this study. Knees were classified into degeneration (D) and non-degeneration (ND) groups according to worsening of the patellar and/or femoral trochlear cartilage at the time of hardware removal (D group, 27 knees) and no degeneration or improvement (ND group, 30 knees). We compared pre- to post-surgery change in hip-knee-ankle angle (HKA) and medial-proximal-tibial angle (MPTA), open-wedge HTO correction angle, and arthroscopic findings between groups.Mean age, height, weight, and body mass index were 54.1 ± 9.9 years, 160.4 ± 8.7 cm, 66.4 ± 12.1 kg, and 25.7 ± 3.3 kg/m, respectively. Change in both HKA and MPTA differed significantly between groups. The MPTA cut-off values to predict patellofemoral degeneration were determined to be 10°, associated with an AUC of 0.75 (95% confidence interval [CI] 0.62-0.87).This study evaluated retrospectively the effect of the correction angle during medial open-wedge HTO on patellofemoral joint degeneration. If deformity correction exceeds an MPTA of 10° during open-wedge HTO, degeneration of patellofemoral joint needs to be considered.Level of evidence: Level IV.

Comparative Matched-Pair Analysis of Open-Wedge High Tibial Osteotomy With Versus Without an Injection of Adipose-Derived Mesenchymal Stem Cells for Varus Knee Osteoarthritis: Clinical and Second-Look Arthroscopic Results

BACKGROUND

High tibial osteotomy (HTO) is reported to be an effective treatment for varus knee osteoarthritis (OA) by redistributing the load line within the knee joint. The cell-based tissue engineering approach using mesenchymal stem cells (MSCs) has addressed the issue of articular cartilage repair in knee OA.

PURPOSE

This study aimed to compare the clinical, radiological, and second-look arthroscopic outcomes of open-wedge HTO with versus without an MSC injection and to identify the association between cartilage regeneration and HTO outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Among 271 patients treated with HTO for varus knee OA from September 2009 to April 2014, patients treated with HTO alone (conventional group; n = 50) were pair-matched with those who underwent HTO with an MSC injection (injection group; n = 50) based on sex, age, and lesion size. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) score and Lysholm score. Radiological outcomes evaluated were the femorotibial angle and posterior tibial slope. At second-look arthroscopic surgery, cartilage regeneration was evaluated using the International Cartilage Repair Society (ICRS) grade.

RESULTS

At the time of second-look arthroscopic surgery (mean, 12.4 months [conventional group] and 12.7 months [injection group]), the mean IKDC and Lysholm scores in each group significantly improved: conventional group, from 38.4 ± 9.2 to 55.2 ± 15.0 and from 56.7 ± 12.2 to 79.6 ± 13.5, respectively; and injection group, from 36.5 ± 4.7 to 62.7 ± 14.1 and from 55.7 ± 11.9 to 80.6 ± 15.6, respectively ( P < .001 for all). Clinical outcomes at final follow-up (mean, 38.8 months [conventional group] and 37.2 months [injection group]) further improved from 62.7 ± 14.1 to 64.8 ± 13.4 (IKDC) and from 80.6 ± 15.6 to 84.7 ± 16.1 (Lysholm) ( P < .001 and P = .034, respectively) only in the injection group when compared with the values at second-look arthroscopic surgery. At final follow-up, there was a significant difference in the mean IKDC and Lysholm scores between groups ( P = .049 and P = .041, respectively). Overall ICRS grades, which significantly correlated with clinical outcomes, were better in the injection group than in the conventional group. Radiological outcomes at final follow-up showed improved knee joint alignment relative to patients' preoperative conditions but showed no significant correlation with clinical outcomes or ICRS grade in either group ( P > .05 for all).

CONCLUSION

The group that received an MSC injection scored better on the IKDC and Lysholm scales at final follow-up than the group that did not, although these differences were relatively small. When performing HTO for patients with varus knee OA, an MSC injection should be considered as an additional procedure for improved cartilage regeneration with better clinical outcomes.

[Positive and negative predictors of long-term results after an osteotomy around the knee joint]

A frequently asked question in the context of any surgical procedure, including an osteotomy around the knee joint, is "which parameters are in favor of a therapeutic success in this special case?" If the analysis of the leg geometry is in favor of an osteotomy, then the patient must be assessed further, taking into account the joint status and patient's condition. Positive outcome predictors for long-term success of an osteotomy around the knee, especially for a valgus osteotomy at the tibia are a tibial bone varus angle (TBVA) > 3-5°, knee joint range of motion > 100° flexion, male sex, and a BMI < 30. It is unclear whether the degree of degeneration of the affected (medial) compartment is of special relevance. The severity of malalignment, the patient's sex, and psychopathological comorbidities are not important.

The correlation of sagittal osteotomy inclination and the anteroposterior translation in medial open-wedge high tibial osteotomy-one of the causes affecting the patellofemoral joint?

PURPOSE

For opening-wedge high tibial osteotomy, previous studies have shown that most osteotomies were anterior-inclined. The purpose of this study was to determine the effect of sagittal osteotomy inclination on the anteroposterior translation of osteomized fragments and discuss its possible impact on the patellofemoral joint.

METHODS

We retrospectively measured the angle between the joint line and the sagittal osteotomy line. We also evaluated the anteroposterior translation of osteomized fragments by measuring the distance from the most posterior point of the tibial plateau to the tibial tuberosity and the anterior cortical line. Correlation between the sagittal osteotomy inclination and the anteroposterior translation of fragments was analyzed.

RESULTS

The mean sagittal osteotomy inclination was 6.3 ± 8.4° anteriorly to the joint line and 82% of osteotomies were anterior-inclined. The anteroposterior translation of the osteomized fragments was moderately correlated to the sagittal inclination. Anterior-inclined osteotomy tends to result in the anterior translation of the proximal fragment.

CONCLUSION

High rates of anterior-inclined osteotomy have been described previously as well as in this study. Anterior-inclined osteotomy tends to result in the anterior translation of the proximal fragment. This may result in increased vertical vector force onto the patellofemoral joint, which further accelerates patellofemoral joint degeneration. Therefore, surgeons should attempt to perform parallel osteotomy or avoid anterior displacement of the proximal fragment if there is concern of anterior-inclined osteotomy.

A critical appraisal of medial open wedge high tibial osteotomy for knee osteoarthritis

A medial open wedge high tibial osteotomy (MOWHTO) is an effective surgical procedure to correct varus deformity related to Knee Osteoarthritis. It consistently provides relief in knee pain and improves knee function. This technique is recommended for active, middle and old aged individuals with an isolated medial compartment knee OA. The MOWHTO scores several advantages over lateral closed wedge osteotomy and hence is now a preferred choice of HTO.

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.

The use of factor Xa inhibitors following opening-wedge high tibial osteotomy for venous thromboembolism prophylaxis

PURPOSE

This study aimed to investigate the incidence of venous thromboembolism (VTE) after medial opening-wedge high tibial osteotomy (OWHTO) and evaluate the efficacy and safety of edoxaban for the prevention of VTE in patients undergoing OWHTO.

METHODS

A total of 139 patients with osteoarthritis or osteonecrosis undergoing OWHTO were enrolled in this prospective, randomized study. Four patients were excluded because of preoperatively diagnosed VTE, and 135 patients were divided into two groups-an edoxaban group and a non-edoxaban group-and underwent computed tomography venography on day 7 to check for postoperative VTE. Blood samples were taken on the day before OWHTO and on postoperative days 1, 3, 7, and 14.

RESULTS

Treatment with edoxaban reduced the incidence of VTE after OWHTO; however, there was no statistically significant difference between the two groups. No major bleeding was noted in the edoxaban group. There were significant differences in the D-dimer level, prothrombin time, fibrinogen level, and thrombin antithrombin complex levels between the groups.

CONCLUSIONS

Edoxaban is an oral, once-daily, selective, direct factor Xa inhibitor that is safe and easy to handle. It may offer a new option for preventing VTE after OWHTO.

LEVEL OF EVIDENCE

I.

Survivorship of medial opening wedge high tibial osteotomy in the elderly: two to ten years of follow up

BACKGROUND AND PURPOSE

Medial opening wedge high tibial osteotomy (MOWHTO) is a well-accepted procedure, which has been widely used for pain relief and varus deformity correction in the osteoarthritic (OA) knee, especially in the young patient. However, in the elderly patient, the efficacy of this procedure is still unknown. Therefore, this study aims to evaluate the survivorship of MOWHTO in elderly patients as the primary outcome. The secondary outcome is to evaluate the loss of correction angle that is the common complication after MOWTHO.

MATERIALS AND METHOD

A retrospective study of 50 elderly patients (≥ 60 years) was conducted to track survivorship of MOWHTO. All patients were diagnosed with varus OA knee and underwent MOWHTO at our institute. The patients who had previous knee surgery or incomplete data were excluded. Medical records and radiographs of eligible patients were reviewed for recruiting the data. Survivorship of MOWHTO was analyzed using Kaplan-Meier curves. The starting point was the time of operation and the end point was the time of subsequent TKA. The loss of correction angle was defined as the change of medial proximal tibial angle (MPTA) between three months and one year post-operatively.

RESULTS

The mean age of patients was 66 ± 5.0 years. The majority of patients were female (74%). The mean correction angle was 10.6 ± 3.6 degrees. The union rate of osteotomy site was 100%. In survival analysis, the median follow-up time was 6.0 ± 3.0 years. Two patients required subsequent conversions to TKA. The survivorship of MOWHTO at four years was 95.5% (95%CI, 96.0 to 98.0). For radiographic assessment, the loss of correction angle was 1.0 ± 0.5 degrees at one year post-operatively.

CONCLUSION

This study proved that MOWHTO in patient ≥60 years had good mid-term survivorship with acceptable complications. This procedure can be the alternative option for the treatment of varus OA knee in the elderly.

High tibial osteotomy in varus knees: indications and limits

Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure that aims to correct the weight-bearing axis of the knee, moving the loads laterally from the medial compartment. Conventional indications for OWHTO are medial compartment osteoarthritis and varus malalignment of the knee; recently OWHTO has been used successfully in the treatment of double and triple varus. OWHTO, in contrast to closing wedge high tibial osteotomy, does not require fibular osteotomy or peroneal nerve dissection, or lead to disruption of the proximal tibiofibular joint and bone stock loss. For these reasons, interest in this procedure has grown in recent years. The aim of this study is to review the literature on OWHTO, considering indications and prognostic factors (body mass index, grade of osteoarthritis, instability, range of movement and age), outcomes at mid-term follow-up, and limits of the procedure (slope modifications, patellar height changes and difficulties in conversion to a total knee arthroplasty).