Higher survival rate in total knee arthroplasty after high tibial osteotomy than that after unicompartmental knee arthroplasty

Total knee arthroplasty after prior high tibial osteotomy results in comparable survival and clinical outcomes but significantly higher complication rates compared to primary total knee arthroplasty: a systematic review and meta-analysis of 550,000 patients

BACKGROUND

High Tibial Osteotomy (HTO) is an effective surgical option in managing medial compartment knee osteoarthritis in the relatively younger population group but most will eventually require conversion to Total Knee Arthroplasty (TKA). TKA post-HTO is considered more complex than a primary TKA, given the numerous factors that increase the difficulty of the surgery-skin and soft tissue scarring, patella baja, limited knee motion, anatomical deformity or bony distortion of the proximal tibial metaphysis after HTO.

METHODS

A random-effects meta-analysis of comparative studies between TKA post-HTO and primary TKA was performed. We searched MEDLINE, EMBASE, Cochrane Library and SCOPUS from inception to August 1, 2024. Survivorship outcomes in terms of revision rates were analyzed. Where possible, further subgrouping to assess the impact of different techniques was performed. Secondarily, associated complications, surgical duration and clinical outcomes (Hospital for Special Surgery (HSS) Scores and Knee Society Scores (KSS) (Knee & Function)) were pooled.

RESULTS

At short-term follow-up, pooled revision rate for TKA post-HTO was 2.9% (95%CI 1.7-5.1) while that for primary TKA was 1.9% (95%CI 1.2-2.9). At mid-term follow-up, the pooled revision rate was 4.8% (95%CI 2.8-8.2) compared to 3.0% (95%CI 1.9-4.8) in primary TKA. At long-term follow-up, the pooled revision rate for TKA post-HTO was 7.2% (95%CI 1.3-30.9), while that of primary TKA was 4.1% (95%CI 1.6-10.2). No significant differences were noted between both groups at each follow-up. Pooled complication rate for TKA post-HTO was 15.8% (95%CI 12.3-20.0%), while that for primary TKA group was 6.1% (95%CI3.5-10.4). TKA post-HTO had significantly greater complication rates than in primary TKA (WMD: 2.6, 95%CI 2.2-3.1, p < 0.01). Pooled mean postoperative HSS scores were 83.5 (95% CI 80.1-86.8) in the TKA post-HTO group, compared to 86.1 (95% CI 82.3-90.0) in the primary TKA group. Pooled mean postoperative KSS (Knee) scores were 85.9 (95% CI 83.6-88.2) in the TKA post-HTO group, and 88.1 (95% CI 84.4-91.7) in the primary TKA group. Pooled mean postoperative KSS (Function) scores were 77.1 (95% CI 72.1-82.1) in the TKA post-HTO group and 78.4 (95% CI 74.5-82.5) in the primary TKA group. No significant differences were noted between both groups.

CONCLUSION

TKA post-HTO has comparable survival but significantly higher complication rates than primary TKA.

Better accuracy of robotic-assisted total knee arthroplasty compared to conventional technique in patients with failed high tibial osteotomy

PURPOSE

This study aimed to compare the clinical outcomes, mechanical axis, component positioning, leg length discrepancy (LLD), and polyethylene liner thickness between robotic-assisted total knee arthroplasty (TKA) and conventional TKA in patients with failed high tibial osteotomy (HTO).

METHODS

A total of 30 patients (30 knees) with failed HTO who underwent TKA using a robot-assisted system between June 2020 and December 2023 were included in this study (robotic group). Additionally, 60 patients (60 knees) with failed HTO who underwent conventional TKA were included as controls (conventional group). Propensity score matching was performed using a 2:1 ratio between the matched participants. The mean follow-up period was 2.1 years in the robotic group and 2.2 years in the conventional group. Clinical evaluations were performed using the Knee Society Score (KSS) rating system. Mechanical axis, component coronal and sagittal positioning, and LLD were evaluated using postoperative radiographs. The thickness of the polyethylene liner was also determined. The mean error values and outliers were calculated and compared between the two groups to determine the accuracy of the mechanical axis, postoperative component positioning, and LLD.

RESULTS

The postoperative KSSs in the robotic and conventional groups were not statistically different. The robotic group achieved better accuracy than the conventional group in terms of postoperative mean mechanical axis (1.7° vs. 2.4°, p < 0.05), femur coronal inclination (90.0° vs. 91.6°, p < 0.05), tibial coronal inclination (90.3° vs. 91.3°, p < 0.05), tibial sagittal inclination (90.5° vs. 91.4°, p < 0.05), and LLD (2.2 vs. 7.0 mm, p < 0.05). A significant difference in polyethylene liner thickness was observed between the two groups (p < 0.05).

CONCLUSIONS

Robotic-assisted TKA showed improved mechanical axis, higher accuracy of component positioning and polyethylene liner thickness, and reduced LLD compared with those of conventional TKA in patients with failed HTO. Further studies with a larger sample size and long-term follow-up are warranted to ascertain whether the accuracy of robotic-assisted TKA can translate into better clinical outcomes and patient satisfaction.

Clinical and functional outcomes of TKA after HTO or UKA: a New Zealand Joint Registry Study

INTRODUCTION

Surgical options for patients with unicompartmental knee osteoarthritis include high tibial osteotomy (HTO) or unicompartmental knee arthroplasty (UKA). When managing younger patients with a higher chance of further surgery, the outcome of any subsequent conversion to total knee arthroplasty (TKA) also needs to be considered. The aim of this study was to compare implant survivorship and patient-reported outcomes for patients undergoing TKA after previous HTO or UKA, with comparisons for age, gender and comorbidities.

METHODS

Revision risk and 6-month Oxford Knee Scores (OKS) from the New Zealand Joint Registry were compared for patients who underwent TKA after HTO (HTO-TKA; n = 1556) or UKA (UKA-TKA; n = 965) between 1999 and 2019, with a comparison group of primary TKA (n = 110,948). Mean follow-up was 8.2 years.

RESULTS

Adjusted revision risk was similar for HTO-TKA and UKA-TKA groups (hazard ratio (HR) 1.04, p = 0.84); and risk for both groups were higher than primary TKA (HTO-TKA HR 1.45, p = 0.002; UKA-TKA HR 1.51, p = 0.01). Overall adjusted mean OKS at 6 months for HTO-TKA (36.2) was similar to primary TKA (36.8, p = 0.23); and both were higher than UKA-TKA (34.2, p < 0.001). For the youngest patient group (< 55 years), revision rates of UKA-TKA were two-fold higher than HTO-TKA (2.8 vs. 1.3 per 100 component yrs, p < 0.03). HTO-TKA had better OKS (37.5 vs. 34.1, p < 0.0001) for males. Mean OKS for UKA-TKA was lower than HTO-TKA for patients with ASA 1-2 (35.6 vs. 37.5, p < 0.01).

CONCLUSION

The findings from this study suggest that revision rate following TKA after HTO and UKA are similar. However, TKA after HTO have superior functional outcomes compared with TKA after UKA and are comparable to functional outcomes post primary TKA. The results support the use of HTO for young, male and less co-morbid patients.

High tibial osteotomy versus unicompartmental knee arthroplasty in advanced medial compartmental knee arthrosis: A comparative study with propensity score matched analysis

BACKGROUND

Isolated knee medial compartmental osteoarthritis(MOA) can be treated with High Tibial Osteotomy (HTO) or Unicompartmental Knee Arthroplasty (UKA). This study aims to describe and compare outcomes of HTO and UKA in patients with isolated severe MOA. The authors hypothesized that similar outcomes can be achieved.

METHODS

Data was collected prospectively of HTOs and UKAs performed between January-2016 and April-2021 by a knee surgeon. Oxford Knee Score (OKS), Knee Society Knee Score (KSKS) and Function Score (KSFS) were collected pre-operatively, six-months and two-years post-surgery. OA severity was graded on pre-operative radiograph. Medial Proximal Tibia Angle (MPTA), Lateral Distal Femoral Angle (LDFA), Joint Line Convergence Angle (JLCA) and Hip-Knee-Ankle Angle (HKAA), were measured on full-length radiograph. 47 HTO and 74 UKA were included. Propensity score matching was performed, accounting for preoperative scores, age, gender and body mass index (BMI), before statistical analysis. Level of significance was set at 0.05.

RESULTS

Both groups were similar in age(56.42 vs 58.57, p = 0.067), BMI(29.82 vs 29.09, p = 0.484), gender distribution (p = 0.663) and laterality (p = 0.836). Pre-operatively, both groups were similar in clinical scores and lower limb alignment. On follow-up, both groups achieved similar improvements in clinical scores. However, the HTO group reported poorer extension at 6-months (7.91° vs 4.80°, p = 0.013) and 2-years (5.57° vs 3.24°, p = 0.018). Three cases of hinge fracture and six cases of implant removal occurred in the HTO group. One case of tibial fracture occurred in the UKA group.

CONCLUSIONS

In severe MOA, similar outcomes were achieved with HTO and UKA at two years.

High survivorship and low complication rate in a single-centre series of 651 medial opening wedge high tibial osteotomy cases with a mean follow-up of 13 years

PURPOSE

This study aimed to report the early to midterm results of medial opening wedge high tibial osteotomy (MOWHTO) from the largest single-centre osteotomy database. The primary outcomes were reporting the radiological corrections and the functional outcomes represented by multiple patient-reported outcome measures (PROMs). The secondary outcomes were to report the complications, revisions and survivorship up to 10 years postoperatively.

METHODS

A prospectively maintained single-centre database of 1138 knee osteotomies was retrospectively reviewed. Patients who underwent MOWHTO and met the inclusion criteria were included. Those inclusion criteria were moderate to severe knee pain that failed conservative management; varus knee malalignment; and isolated medial osteoarthritis of the knee. A total of 651 cases, with a mean age of 46.7 ± 9 years and a mean body mass index of 29.6 ± 5.2 kg/m2 , were included. This comprised 71% males (n = 462) and 29% females (n = 189). The mean follow-up was 158.1 ± 45.4 months. Multiple PROMs were recorded preoperatively and serially postoperatively. This included the Knee injury and Osteoarthritis Outcome Scores, the Oxford Knee Score, the Oxford Knee Score-Activity and Participation Questionnaire, the Western Ontario and McMaster University Scores, the Visual Analogue Scale for health and pain, and the EQ-5D, which is a standardised measure of health-related quality of life. All lower limb alignment measurements were recorded pre- and postoperatively. The rates of osteotomy revision, conversion to arthroplasty, complications, and 5- and 10-year survivorship were recorded.

RESULTS

A total of 651 cases were followed up to a mean of 158.1 ± 45.4 months. The mean planned correction angle was 7.6° ± 2.9°. The mean planned opening wedge distance was 8.1 ± 3.1 mm. The mean intraoperative anterior and posterior osteotomy gaps opening were 7.7 ± 3.4 and 8.9 ± 3.8 mm, respectively. Postoperatively, the mean mechanical tibiofemoral angle improved from -5.7° ± 2.9° varus to 1.3° ± 2.5° valgus, the mean medial proximal tibial angle improved from preoperative 85.5° ± 2.3° to postoperative 91.6° ± 2.7° and the mean Mikulicz point improved from 21.7 ± 12.6% to 54.8 ± 11% (all p values < 0.001). All PROMs significantly improved at 24 months follow-up (all p values < 0.001). The rate of osteotomy revision was 1.1% at a mean of 2 ± 2.5 years postoperatively. The overall rate of arthroplasty conversion was 9.1%. This comprised 5.8% total knee arthroplasty conversion at a mean of 6.9 ± 3.5 years postoperatively and 3.2% unicompartmental knee arthroplasty conversion at a mean of 5.7 ± 2.5 years postoperatively. An overall 10.3% complication rate was recorded. The 5 and 10-year survivorship was 97.2% and 91.9%, respectively.

CONCLUSION

MOWHTO is a radiologically and clinically rewarding procedure with a high survival rate at 5 and 10 years and a low complication rate in experienced hands. MOWHTO should be considered in patients presenting with medial unicompartmental knee pain with an evidence of overload and a varus mechanical coronal plane axis.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

20-Year Outcomes of High Tibial Osteotomy: Determinants of Survival and Functional Outcome

BACKGROUND

High tibial osteotomy (HTO) is a successful joint-preserving procedure for the treatment of medial compartment osteoarthritis. Long-term survivorship of HTO ranges from 40% to 85%. There are consistent factors that predict failure.

PURPOSE

To determine the 20-year survival of HTO and identify predictors of failure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 100 consecutive patients with medial bone-on-bone arthritis were prospectively studied to provide long-term patient-reported outcome measures after lateral closing-wedge HTO and determine the time to failure. Failure was defined as conversion to arthroplasty (total knee arthroplasty or unicompartmental knee arthroplasty) or revision HTO.

RESULTS

At 20 years, HTO survival was determined in 95 patients, and 5 were lost to follow-up. The overall survivorship of HTO at 20 years was 44%. The significant factors that were associated with better survivorship were age <55 years, body mass index <30, and Western Ontario and McMaster Universities Osteoarthritis Index pain score >45. These factors were used to define the favorable candidates. In the favorable candidates, survivorship was 100% at 5 years, after which there was a gradual decline to 62% survival at 20 years. Of those with HTO survival, 32 of 33 (97%) reported satisfaction with surgery, with a mean Knee injury and Osteoarthritis Outcome Score Pain score of 91 and Activities of Daily Living score of 97.

CONCLUSION

HTO is a successful surgical option to treat medial compartment osteoarthritis and prevent the need for arthroplasty in young patients. The most suitable candidates for HTO are aged <55 years, are not obese, and have not progressed to severe symptomatic disability.

Satisfactory long-term outcomes for combined anterior cruciate ligament reconstruction and lateral closing wedge high tibial osteotomy

PURPOSE

A combined anterior cruciate ligament (ACL) reconstruction and high tibial osteotomy (HTO) is considered a valuable treatment in young patients affected by symptomatic medial osteoarthritis and ACL deficiency. However, only a few studies have investigated the outcomes of this procedure, especially in the long term. Therefore, the aim of this study is to report clinical and radiographic outcomes of ACL reconstruction and lateral closing wedge HTO at a mean of 14 years of follow-up.

METHODS

Patients were prospectively evaluated pre-operatively, after 6.5 ± 2.7 years and 14.3 ± 2.2 years. Patient-reported outcome measures (PROMs) were collected, knee laxity was assessed through KT-1000 arthrometer, and limb alignment and knee osteoarthritis were evaluated on long-cassette radiographs. Survivorship of the surgical procedure was calculated through the Kaplan-Meier method.

RESULTS

32 patients were initially enrolled and completed the mid-term evaluation (6.5 ± 2.7 years), and 23 patients (72%) were available for the final evaluation at 14.3 ± 2.2 years after surgery. Statistically significant improvement was found for all the clinical scores (VAS, WOMAC, Tegner, subjective IKDC, objective IKDC) between the pre-operative status and the mid-term follow-up (p < .001). VAS, subjective IKDC and objective IKDC showed no statistically significant differences (p > .05) between the mid-term and the final follow-up; a significant decrease of WOMAC (p < .05) and Tegner (p < .001) was found from mid-term to final follow-up. Significant progression of osteoarthritis was found for all the knee compartments. The survivorship was 95.7% at 5 years, 82.6% at 10 years, and 72.8% at 15 years.

CONCLUSIONS

Combined ACL reconstruction and lateral closing wedge HTO showed satisfactory clinical outcomes and survivorship at a mean of 14 years follow-up.

LEVEL OF EVIDENCE

IV.

Research on the Influence of the Allogeneic Bone Graft in Postoperative Recovery After MOWHTO: A Retrospective Study

Purpose

To compare the effects of an allogeneic bone graft and a non-filled bone graft on the rate of osteotomy gap union in medial opening wedge high tibial osteotomy (MOWHTO) with an opening width less than 10 mm.

Methods

A total of 65 patients undergoing MOWHTO between January 2018 and December 2020 were enrolled in this retrospective study. The patients were divided into two groups: the allograft group (MOWHTO with allogeneic bone grafting, 30 patients) and the non-filling group (MOWHTO without bone void fillers, 35 patients). The clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), Lysholm score, and post-operative complications, were compared. The radiographic evaluation included changes in hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), femorotibial angle (FTA), and weight-bearing line ratio (WBLR) at pre-operation, at two-day post-operation, and the last follow-up. Radiographs were obtained at three, six and twelve months post-surgery, and at the time of the last follow-up to assess the fill area of the osteotomy gap. The union rate of the osteotomy gap was calculated and compared, and risk factors that may affect the rate of osteotomy gap union were also discussed.

Results

The rate of osteotomy gap union at 3 and 6 months after the operation in the allograft group was significantly higher compared with the non-filling group (all P<0.05), while no significant difference was found after the 1-year post-operative and at the last follow-up. Also, the WOMAC and Lysholm scores of the allograft group were significantly higher than those of the non-filling group (all P<0.05), and there was no significant difference between the two groups at the last follow-up.

Conclusion

Filling the gaps with the allograft bones may accelerate the union of osteotomy gap, improve clinical outcomes, and have important implications for patient rehabilitation in the early post-operative course. Bone grafting did not affect the final rate of osteotomy gap union and the clinical score of patients.

Unicompartmental knee arthroplasty is associated with lower pain levels but inferior range of motion, compared with high tibial osteotomy: a systematic overview of meta-analyses

Background

The purpose of this study was to overview the findings of reported meta-analyses on unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO).

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 (PRISMA 2020) guidelines were followed. Two independent reviewers conducted a literature search of PubMed, Embase, the Web of Science, and the Cochrane Database of Systematic Reviews for meta-analyses comparing UKA and HTO that were published prior to September 2021. Literature screening, data extraction, and article quality appraisal were performed according to the study protocol registered online at PROSPERO (CRD42021279152).

Results

A total of 10 meta-analyses were identified, and different studies reported different results. Five of the seven meta-analyses showed that the proportion of subjects with excellent or good functional results was higher for UKA than for HTO. All three meta-analyses showed that UKA was associated with lower pain levels, and all six of the studies that included an analysis of range of motion (ROM) reported that UKA was inferior to HTO. Four of the eight meta-analyses found that total complication rates were lower for UKA. Only 3 of the 10 meta-analyses found that UKA had lower revision rates. Moreover, in the subgroup analysis, the revision and complication rates of UKA were similar to those of opening-wedge HTO but much lower than those of closing-wedge HTO.

Conclusions

Compared to HTO, UKA was associated with lower pain levels but inferior postoperative ROM. The results were inconclusive regarding whether UKA yielded better knee function scores and lower revision or complication rates than HTO. Accurate identification of indications and appropriate patient selection are essential for treating individuals with OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03319-7.

Clinical Outcomes of Revision Total Knee Arthroplasty after High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis

As more high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are performed, orthopaedic surgeons realize that more HTO and UKA failures will require revision to total knee arthroplasty (TKA) in the future. To systematically evaluate the clinical outcomes of TKA after HTO and TKA after UKA, the Embase, PubMed, Ovid, Web of Science, and Cochrane Library databases were searched for studies investigating revision TKA after HTO and UKA published up to June 2021. RevMan version 5.3 was used to perform the meta‐analysis. The revision TKA after HTO and revision TKA after UKA groups were compared in terms of operative time, range of motion (ROM), knee score, postoperative complications, postoperative infection, revision, and revision implants used. Nine studies were ultimately included in the meta‐analysis. Results revealed that the knee score for the revision TKA after HTO group was better than that of the revision TKA after UKA group (MD 4.50 [95% CI 0.80–8.20]; p = 0.02). The revision TKA after HTO group had a lower revision rate (OR 0.65 [95% CI 0.55–0.78]; p < 0.00001) and fewer revision implants used (OR 0.11 [95% CI 0.05–0.23]; p < 0.00001). There were no statistical differences in operation time (MD ‐2.00 [95% CI −11.22 to 7.21]; p = 0.67), ROM (MD ‐0.04 [95% CI ‐3.69–3.61]; p = 0.98), postoperative complications (OR 1.41 [95% CI 0.77–2.60]; p = 0.27), or postoperative infections (OR 0.89 [95% CI 0.61–1.29]; p = 0.53). To conclude, the revision rate of revision TKA after UKA was greater, and more revision implants were required. It is important for orthopaedic surgeons to preserve bone during primary UKA.

Not using a tourniquet is superior to tourniquet use for high tibial osteotomy: a prospective, randomised controlled trial

PURPOSE

Tourniquets are routinely used in high tibial osteotomy (HTO). However, research on the necessity of tourniquets during HTO is lacking. This study was designed to investigate the necessity of tourniquets in HTO.

METHODS

This was a prospective study that included patients who underwent HTO at the same hospital. The patients were randomised into Group A (non-tourniquet, n = 45) and Group B (tourniquet, n = 45). Same surgical techniques and haemostatic methods were used in the two groups.

RESULTS

All patients were followed up for more than three months. There was no difference in operation time, and no intra-operative vascular or nerve damage occurred in either group. The hospital stay was shorter in group A than in group B (p < 0.05). There was no difference in post-operative blood loss, haemoglobin or haematocrit (p > 0.05). The post-operative visual analogue scale (VAS) pain scores and calf swelling were lower in group A (p < 0.05), and the early knee range of motion was higher in group A (p < 0.05). The use of morphine and the incidence of thigh complications were also lower in group A (p < 0.05). There was no difference in the VAS and knee function between the two groups at three months post-operatively (p > 0.05).

CONCLUSION

Tourniquet use during HTO does not reduce post-operative blood loss, operation time or intra-operative complications, but not using a tourniquet shortens the hospital stay and reduces the post-operative usage of morphine and tourniquet-related complications, which promotes early recovery of knee function.