Preoperative overweight and obesity do not cause inferior outcomes following open-wedge high tibial osteotomy: A retrospective cohort study of 123 patients

Conversion to Total Knee Arthroplasty After High Tibial Osteotomy: A Systematic Review and Meta-analysis

Background

High tibial osteotomy (HTO) is a treatment option for younger, active patients with medial compartment knee osteoarthritis. Clinical results of HTO have been shown to deteriorate over time despite initial satisfactory results, requiring patients to eventually undergo conversion to total knee arthroplasty (TKA). Evidence monitoring survivorship of HTO remains scarce and potentially outdated.

Purpose

To investigate the impact of concomitant cartilage repair procedures, conversion to TKA, and associated complications for HTO.

Study Design

Systematic review; Level of evidence, 4.

Methods

We searched MEDLINE, Embase, Cochrane Library, and SCOPUS from inception to July 18, 2023, for studies reporting on survivorship and associated complications after medial opening-wedge HTO. Pooled analysis of conversion to TKO was categorized as occurring at <5 years, 5 to 10 years, or >10 years postoperatively. Further subgrouping was performed on studies reporting on HTO with concomitant cartilage repair procedures.

Results

Overall, 59 studies comprising 5162 patients were included. Rates of conversion to TKA were 4.5% at <5 years, 8.3% at 5 to 10 years, and 11.2% at >10 years. When comparing patients with isolated HTO versus HTO with concomitant cartilage procedures (including mesenchymal stem cell augmentation, osteochondral allograft transplantation, microfracture, abrasion arthroplasty, and autologous chondrocyte implantation), there was no significant difference in survival rates at <5 years (relative risk, 0.78 [95% CI, 0.45-1.33]; P = .36) or 5 to 10 years (relative risk = 0.76 [95% CI, 0.32-1.83]; P = .55). The overall complication rate was 12.1%; intraoperative lateral hinge and tibial plateau fractures had pooled complication rates of 1.6% and 2.0%, respectively. The rate of nonunion was 1.7%, and pooled rates of superficial and deep infections were 2.6% and 2.0% respectively.

Conclusion

Rates of conversion to TKA and complications were low and acceptable, although survival rates decreased with time. Concomitant cartilage repair procedures as a whole did not significantly improve survivorship; however, more high-quality studies are warranted to determine the impact of individual concomitant cartilage repair procedures.

Comparative outcomes of proximal fibular osteotomy versus high tibial osteotomy in patients with medial knee osteoarthritis: A retrospective analysis

High tibial osteotomy (HTO) is a widely used procedure for delaying knee arthroplasty, correcting alignment, and relieving symptoms in patients with knee osteoarthritis. Recently, proximal fibular osteotomy (PFO) has emerged as a less invasive and more cost-effective alternative. This study compares the outcomes of HTO and PFO to evaluate whether PFO can deliver results comparable to HTO in similar patient populations. A total of 96 patients treated between 2018 and 2022 were analyzed, with 54 patients undergoing HTO and 42 undergoing PFO. Subgroups were also created based on body mass index (BMI): non-obese HTO, obese HTO, non-obese PFO, and obese PFO. For each patient, we recorded demographic data, preoperative and 1-year postoperative Oxford Knee Scores (OKS), visual analog scale (VAS) scores, medial joint space (MJS) measurements, mechanical axis deviations (MAD), Kellgren- Lawrence grade (KL), medial proximal tibial angle (MPTA), and any complications. Both HTO and PFO led to significant improvements in OKS, VAS, MJS width, and MAD. Age, KL grade distribution, BMI, and MPTA values were comparable across the groups. Overall, HTO showed superior clinical (OKS, VAS) and radiological (MJS, MAD) outcomes, particularly in non-obese patients. Among obese patients, HTO and PFO achieved similar clinical improvements, although HTO maintained a radiological advantage. Importantly, a lower preoperative MPTA was associated with poorer clinical outcomes in the PFO group. In conclusion, while PFO can produce meaningful clinical and radiological improvements, HTO remains the more effective option in terms of both clinical and radiological outcomes in patients with a BMI below 30. For patients with a BMI over 30, HTO preserves its radiological superiority, although its clinical benefits are comparable to those of PFO. Additionally, a low preoperative MPTA is significantly linked to worse OKS scores in patients undergoing PFO.

Medial opening wedge high tibial osteotomy performs similarly irrespective of body mass index

PURPOSE

This study investigates the effect of the body mass index (BMI) on the early (2 years) to midterm (5 years) results of medial opening wedge high tibial osteotomy (MOWHTO).

METHODS

A prospectively maintained single-centre database of 1138 knee osteotomies, between 2002 and 2022, was retrospectively reviewed. Adult patients who underwent MOWHTO for symptomatic unicompartmental medial knee osteoarthritis (OA), with varus knee malalignment, having failed conservative management, were included. Patients were categorized into three groups according to their BMI as per the classification from the National Institute for Health and Care Excellence (NICE): the healthy weight (HW) group (BMI of 18.5-24.9 kg/m2), the overweight (OW) (BMI of 25-29.9 kg/m2), and the obesity (OB) group (BMI ≥ 30 kg/m2). Multiple patient-reported outcome measures (n = 6) were recorded preoperatively and at 2 and 5 years postoperatively. Deformity analysis was undertaken preoperatively and postoperatively. The relative risk (RR) of the complications between the HW, OW and OB groups was calculated. The rate of conversion to arthroplasty, and 5 and 10 years survivorship were recorded, as well as the hazard ratio (HR) of BMI on survivorship.

RESULTS

A total of 574 cases were included in the study: the HW group (n = 96), the OW group (n = 233) and the OB group (n = 245), with a mean BMI of 23 ± 1.5 kg/m2, 27.4 ± 1.4 kg/m2 and 34.4 ± 3.8 kg/m2, respectively. The mean follow-up was 13.3 years (4.8-20.3). The mean mechanical tibiofemoral angle corrections were in the HW group: 7.1 ± 3°, OW group: 6.6 ± 3.5° and OB group: 7.1 ± 3.8°, with no intergroup significant difference (p = n.s.). Clinically, despite lower preoperative scores in the OW and OB groups, no difference was observed postoperatively amongst the three groups. The overall complication rate was 12.5% in the HW group, 6.8% in the OW group, and 9.8% in the OB group. There was no significant difference in the RR of complications between the HW and OW groups (RR = 0.6, 95% confidence interval [CI] = 0.3-1.3) (p = 0.2), and the HW and OB groups (RR = 0.8; 95% CI = 0.3-2.2) (p = 0.7). There was no overall significant difference in survival outcomes based on the BMI between the three groups (p = 0.4). The HR of conversion to arthroplasty between the HW and OW groups was 1.4 [95% CI = 0.6-3.5](p = 0.5) and between the HW and OB groups was 1.8 [95% CI = 0.8-4.4] (p = 0.2).

CONCLUSION

BMI has no significant effect on either the radiological corrections, clinical outcomes, complications or survivorship of MOWHTO at short- to medium-term follow-up. No specific cutoff point for BMI can be recommended as a contraindication to MOWHTO.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Obesity does not impact complications and conversion to total knee arthroplasty after high tibial osteotomy: A systematic review

PURPOSE

The purpose of this systematic review is to consolidate outcomes of obese patients undergoing high tibial osteotomy and to investigate the effect of obesity on postoperative outcomes, including symptomatic relief and time to conversion to arthroplasty.

METHODS

Medline, Embase and Cochrane Library were searched from database inception up to April 2023 according to PRISMA guidelines by two reviewers. Search terms including 'obesity', 'BMI', 'osteotomy' and 'high tibial osteotomy (HTO)' were included to identify all relevant articles. Only studies that explicitly reported outcomes for obese patients were included. Disagreements in study inclusion or quality assessment were resolved by a senior third reviewer. Metrics compared include time to arthroplasty, preoperative and postoperative mechanical tibiofemoral angle (mTFA), patient-reported satisfaction scores and postoperative complications.

RESULTS

Nine studies comparing 973 patients were included. The mean age was 52.7 ± 4.2 years old and 38.4% were male. Six studies performed the medial opening-wedge HTO, and three utilized the medial wedge closing technique. Most studies indicated significant improvement following surgical intervention with satisfactory outcomes in obese and nonobese patients. In addition, differences in complication rates were minimal between obese and nonobese patients (n.s.), while functional scores did not vary significantly. Conversion to total knee arthroplasty was not found to increase in obese patients (n.s.).

CONCLUSION

Obesity does not appear to carry a greater complication risk or worse outcomes following high tibial osteotomies, and surgeons should consider HTO a viable option for young obese patients with symptomatic unicompartmental chondral wear with coronal limb malalignment.

LEVEL OF EVIDENCE

Level IV.

Muti-factor analysis of sport activity level after high tibial osteotomy

BACKGROUND

Although many studies have shown that high tibial osteotomy is appropriate for active patients, there are limited multifactorial studies on patients' sport activity level after HTO in general population.

METHODS

158 patients who underwent HTO for knee osteoarthritis between January 2016 and December 2019 are included, with a 36-month follow-up. Information was collected from X-rays and questionnaire. The independent variables were age, sex, breadwinner (provide more than 50% income), sport activity level when the knee was pain-free before and after surgery, concomitant meniscal treatment history, Lysholm knee score, desire level for returning to sports. The 158 cases are divided into three groups according to their sports participation before and after operation, Chi-square tests and ANOVA analysis were adopted to identify the effect of these variables on sport activity level after HTO, and factors with statistical differences and clinical relevancies, or provided by previous research were assessed with the ordinal logistic regression analysis.

RESULTS

According to sport activity level analysis, 28(17.7%) patients were categorized into the sport level-reduced group, 97(61.4%) patients into the sport level-unchanged group, and 33(20.9%) patients into the sport level-improved group. Upon ordinal logistic regression analysis, postoperative MA%, age, BMI, and preoperative Lysholm knee score were statistically significant.

CONCLUSIONS

Higher postoperative MA%, younger age, lower BMI, and lower Lysholm score are associate with improvement on activity level after HTO. This finding provides valuable references in operation option and rehabilitation planning.

The effects on joint functions of biplanar distal tubercle open-wedge high tibial osteotomy: A prospective study

Distal tubercle biplanar open-wedge high tibial osteotomy (DT-BOWHTO) is a method frequently applied in the treatment of knee joint medial osteoarthritis. The aim of this study was to evaluate the radiological, clinical, and functional results of patients at 5 years after DT-BOWHTO surgery. The study included a total of 41 patients who underwent DT-BOWHTO, comprising 19 (46.3%) males and 22 (53.7%) females with a mean age of 55.54 ± 4.17 (45-63) years and mean follow-up of 66.76 ± 6.29 (60-81) months. Statistical comparisons were made of the preoperative and postoperative body mass index (BMI), modified Insall-Salvati index, Blackburn-Peel index, Kelgren-Lawrence classification (KLC), tibial slope angle, American Knee Society Functional Score (AKSFS), Clinical American Knee Society Score (CAKSS), visual analog scale (VAS) pain score, Tegner Functional Activity Score (TFAS), total corrected angular measurements (TCA), and the tibio-femoral varus angle. Compared to the preoperative values, no statistically significant difference was determined in the postoperative modified Insall-Salvati index, Blackburn-Peel index, and tibial slope angle values (P > .05), and a statistically significant difference was determined in the BMI, AKSFS, CAKSS, VAS, KLC, tibio-femoral varus angle, and TFAS values (P ≤ .001). When the preoperative and postoperative BMI values were compared in 3 groups of normal, overweight, and obese, there was found to be a statistically significant difference (P = .014). No significant correlation was determined between the BMI values and the VAS and KLC values (P > .05). No significant correlation was determined between the total corrected angular and the preoperative and postoperative pain, and clinical and functional knee scores (VAS, AKSFS, CAKSS, TFAS) (P > .05). DT-BOWHTO was seen to provide extremely good 5-year results in the knee clinical findings, pain severity, and functional results. As the patella height and tibial slope angle were not changed, this did not cause the development of osteoarthritis in the patellofemoral and tibiofemoral joints. Grafting and fixation of the tibial tubercle with additional screws in the application of DT-BOWHTO were not seen to make any additional contribution to the healing of the osteotomy line. There was no relationship between increased BMI, reduced pain, and increase in knee functions in patients who underwent DT-BOWHTO.