Better clinical outcomes after unicompartmental knee arthroplasty when comparing with high tibial osteotomy

Effects of high tibial osteotomy compared with unicondylar knee arthroplasty on the surgical site wound infection and pain in patients with medial knee osteoarthritis

This study aims to comprehensively compare the effects of unicondylar knee arthroplasty (UKA) and high tibial osteotomy (HTO) on wound infection and pain in patients with medial knee osteoarthritis. A computerized search was conducted in Embase, PubMed, Google Scholar, China National Knowledge Infrastructure, Cochrane Library and Wanfang databases, from database inception to October 2023, for studies comparing UKA and HTO for medial knee osteoarthritis. Studies selection, data extraction and study quality evaluation were independently conducted by two researchers. Stata 17.0 software was employed for data analysis. Overall, 10 studies involving 870 patients with medial knee osteoarthritis were included. It was found that the UKA group had significantly lower wound visual analogue scale scores compared to the HTO group (SMD = -0.53, 95%CI: -0.87 to -0.20, p < 0.001). The incidence of wound infection in the UKA group was higher than in the HTO group (OR = 1.92, 95%CI: 0.65-5.69, p = 0.240), and the incidence of complications was lower (OR = 0.89, 95%CI: 0.52-1.54, p = 0.684), though these differences were not statistically significant. This study indicates that UKA is effective in alleviating postoperative wound pain in medial knee osteoarthritis. However, the rates of postoperative wound infection and complications are comparable to those of HTO. Clinicians should consider factors such as patient age and disease severity in making individualized treatment decisions.

Comparison of Early Complication Rates After High Tibial Osteotomy Versus Unicompartmental Knee Arthroplasty for Knee Osteoarthritis

Background

Although both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) can be utilized to treat unicompartmental osteoarthritis (OA) in select patients, the early complication rates between the 2 procedures are not well understood. Understanding of the complication profiles for both procedures would help clinicians counsel patients with unicompartmental knee OA who may be eligible for either treatment option.

Purpose

To compare the 30-day complication rates after HTO versus UKA for the treatment of knee OA using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

Study Design

Cohort study; Level of evidence, 3.

Methods

NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing HTO and UKA for knee OA. Patients >60 years of age were excluded. Patient demographics, preoperative comorbidities, and intraoperative data were collected. Postoperative 30-day complications, including venous thromboembolism (VTE), urinary tract infection (UTI), transfusion, surgical-site infection (SSI), and reoperations were recorded. Complication rates between treatment groups were compared using a multivariate logistic regression model adjusted for sex, age, body mass index, steroid use, respiratory status (smoking/dyspnea/chronic obstructive pulmonary disease), diabetes, and hypertension.

Results

A total of 156 patients treated with HTO and 4755 patients treated with UKA for knee OA were identified. Mean patient ages were 46 years for the HTO group and 53.4 years for the UKA group. Operative time was significantly longer in the HTO group versus the UKA group (112 minutes vs 90 minutes; P < .001). Multivariate analyses found no significant differences in VTE (1.3% vs 0.6%), UTI (0.6% vs 0.3%), transfusion (0.6% vs 0.2%), deep SSI (0.6% vs 0.1%), and reoperation (1.3% vs 1%) rates between HTO and UKA groups. The HTO group had a higher rate of superficial SSI compared with the UKA group (2.6% vs 0.6%; P = .006) (adjusted odds ratio, 4.2; 95% CI, 1.4-12.5; P = .01).

Conclusion

There were no differences in 30-day VTE, UTI, transfusion, deep SSI, and reoperation rates for HTO versus UKA in the treatment of knee OA. HTO was associated with a higher rate of superficial SSI compared with UKA. These findings serve to guide clinicians in counseling patients regarding the early risks after HTO and UKA.

Severe medial osteoarthritis predicts patient dissatisfaction after proximal fibular osteotomy: a mid- to long-term follow-up study

PURPOSE

This study aimed to investigate postoperative patient satisfaction at mid- to long-term follow-up after proximal fibular osteotomy and to identify risk factors for patient dissatisfaction.

METHODS

This was a retrospective cross-sectional study that included 252 knees from 160 osteoarthritis (OA) patients who underwent proximal fibular osteotomy with a follow-up of four to eight years. Patients were categorized into a satisfied group (satisfaction score ≥ 20) or a dissatisfied group (satisfaction score < 20) based on the New Knee Society Score (New KSS). Patient demographics, preoperative pain visual analogue scale (VAS) score, preoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Kellgren-Lawrence (K-L) grade, preoperative hip-knee-ankle (HKA) angle, and preoperative medial proximal tibial angle (MPTA) were compared between the two groups. Multiple logistic regression analysis was used to identify risk factors for patient dissatisfaction.

RESULTS

Of the 203 knees, 130 (64.0%) were satisfied with their results. Multiple logistic regression analysis demonstrated that severe medial OA (K-L grade = IV) was an independent risk factor for patient dissatisfaction after proximal fibular osteotomy (OR 8.334, 95% CI 3.815-18.206, P < 0.001).

CONCLUSION

Our study confirmed that proximal fibular osteotomy was a simple and effective treatment for medial OA patients, and majority of our patients obtained a higher satisfaction rate within mid- to long-term follow-up after surgery. Severe medial OA, however, was an independent risk factor for dissatisfaction.

Comparison of joint awareness after total knee arthroplasty, medial unicompartmental knee arthroplasty, and high tibial osteotomy: a retrospective study

INTRODUCTION

This study aimed to compare the Forgotten Joint Score-12(FJS) outcomes and the minimum clinically important difference (MCID) of the FJS after high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA), and total knee arthroplasty (TKA) with short-term follow-up (at least 2 years). Another objective of the study is to investigate the factors influencing FJS. It is hypothesized that there are differences in FJS outcomes among the three procedures.

METHODS

Patients who underwent HTO, UKA, and TKA from January 2016 to December 2020 and were followed up for a minimum of 2 years were included in the study. The FJS were analyses from a cohort of people who submitted data to two years. The preoperative and postoperative clinical outcomes were compared and evaluated the patient-related factor. The FJS scores were predicted using multiple linear regression analysis. Additionally, Patient's Joint Perception (PJP) questions were used as anchors to determine the achievement of the forgotten joint, and FJS MCID were calculated using the receiver operating characteristic curve (ROC).

RESULTS

Three hundred eighty-nine patients were included in the final study, and there were 111 patients in HTO groups,128patients in UKA groups, and 150 patients in TKA groups. The mean follow-up was 47.0 months. There was a significant difference in the total FJS, between the HTO, UKA, and TKA groups (FJS:59.38 ± 7.25, 66.69 ± 7.44 and 56.90 ± 6.85, p < 0.001. We found the MCID of the FJS of HTO, UKA, and TKA were 63.54, 69.79, and 61.45, respectively. In multiple linear regression, younger age, and higher FS were significant predictors of better FJS.

CONCLUSION

Medial UKA demonstrated lower patient awareness in comparison to HTO and TKA, as assessed by the FJS. Younger age and higher FS were identified as significant predictors of improved FJS, providing valuable guidance for surgical decision-making.

Surgical interventions for symptomatic knee osteoarthritis: a network meta-analysis of randomized control trials

BACKGROUND

Multiple surgical interventions exist for the treatment of symptomatic knee osteoarthritis, but the surgeon and patient may often have difficulty deciding which interventions are the best option.

METHODS

We conducted a systematic review to identify randomized clinical trials (RCTs) that compared complications, revisions, reoperations, and functional outcomes among TKA (total knee arthroplasty), UKA (unicompartmental knee arthroplasty), HTO (high tibial osteotomy), BCA (bicompartmental knee arthroplasty), BIU (bi-unicompartmental knee arthroplasty), and KJD (knee joint distraction). The PubMed, Embase, and Cochrane databases were reviewed for all studies comparing two or more surgical interventions. Direct-comparison meta-analysis and network meta-analysis (NMA) were performed to combine direct and indirect evidence. The risk of bias was assessed using the revised Cochrane risk of bias tool for RCTs.

RESULTS

This NMA and systematic review included 21 studies (17 RCTs), with a total of 1749 patients. The overall risk-of-bias assessment of the RCTs revealed that 7 studies had low risk, 5 had some concerns, and 9 had high risk. SUCRA (the surface under the cumulative ranking curve) rankings revealed that KJD had the greatest risk of appearing postoperative complications, revisions, and reoperations, and UKA or TKA had the lowest risk. The majority of comparisons among various treatments showed no difference for functional outcomes.

CONCLUSION

Each surgical intervention is noninferior to other treatments in functional outcomes, but UKA and TKA are better options to treat OA according to SUCRA rankings by comparing complications, revisions, and reoperations. KJD is an imperfect option for treating OA. Other treatments should be carefully considered for each patient in accordance with their actual conditions. However, this conclusion is limited by the selection of reviewed publications and individual variation of surgical indications for patients.

TRIAL REGISTRATION

This study was registered with Research Registry (reviewregistry1395).

Comparative Analysis of Unicompartmental Total Knee Arthroplasty and High Tibial Osteotomy: Time to Total Knee Arthroplasty and Other Outcome Measures

Background

There is no consensus on whether unicompartmental arthroplasty (UKA) or high tibial osteotomy (HTO) is superior for unicompartmental arthritis. While there are studies comparing revision and complication rates, none matched a large number of patients undergoing HTO and UKA in the United States and compared these outcomes. We investigated TKA conversion rate and the complications following HTO or UKA.

Methods

This retrospective study queried the PearlDiver database of all patients undergoing UKA and HTO using CPT codes between January 2011 and January 2020. We compared propensity-matched populations based on age, gender, Charlson comorbidity index, and Elixhauser comorbidity index to compare odds of complications, TKA conversion, and drug use between UKA and HTO groups. Two-independent sample t-test for unequal variances and test of significance were performed.

Results

We found 32,583 UKA patients and 816 HTO patients. Each matched group had 535 patients. One-year complication showed higher risk of pneumonia, hematoma, infection, and mechanical complications among HTO patients. UKA patients used narcotics on average of 10.3 days compared to 9.1 days among HTO patients (P < .01). UKA conversion rates were 4.1%, 5.4%, 7.7%, and 9.2% at 1-, 2-, 5-, and 10-year intervals, respectively. HTO conversion rates were less than 2% at 1- and 2-year intervals, 3.4% at 5-year, and 4.5% at 10-year intervals. This difference was statistically significant at 5- and 10-year intervals (P < .01).

Conclusions

Using large matched cohorts, HTO may be converted to TKA later than UKA in short- to mid-term follow-up, and HTO patients used opioids for shorter duration.

Unicompartmental knee arthroplasty versus high tibial osteotomy for medial knee osteoarthritis: A systematic review and meta-analysis

We aimed to systematically compare the clinical and functional outcomes between unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) for the treatment of medial knee osteoarthritis (KOA). Literatures were searched from PubMed, EMBASE, the Cochrane library, Wanfang DATA, China National Knowledge Infrastructure (CNKI) and SinoMed database until December 2020. Studies comparing postoperative clinical and functional outcomes of UKA versus HTO were included. Totally, 38 studies were included, including 2368 patients with 2393 knees in HTO group and 6536 patients with 6571 knees in UKA group. There was significant difference in postoperative pain, revision rate, complications, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between HTO and UKA groups (p < 0.05). No significant difference was found in excellent/good surgical results, Lysholm, Hospital for Special Surgery (HSS) score, Knee Society Knee (KSS) score, knee and function score of Knee Society (KSFS) score and Tegner score between these two groups (p > 0.05). UKA produced less postoperative pain, less complications and superior WOMAC score, whereas HTO offered extended range of motion (ROM) and less revision rate.

Higher activity level after opening wedge high tibial osteotomy compared to medial unicompartimental knee arthroplasty in a selected cohort of advanced age: A propensity score-matched analysis

BACKGROUND

High tibial osteotomy (HTO) and medial unicompartmental knee arthroplasty (mUKA) are accepted treatment for medial knee osteoarthritis (OA). Patients often present meeting indications for both procedures. The purpose of this study was to compare results after MOWHTO and UKA in a matched population of patients older than 50 years.

METHOD

A retrospective analysis searching for patients older than 50 years meeting indication both for UKA and MOWHTO was performed. A propensity score matching (PSM) based on demographics and clinical data was performed. Tegner activity scale (TAS), Lysholm knee score (LKS) and numeric rating scale for pain (NRS) were recorded prospectively prior to surgery, at 6 months and after a minimum of 4 years.

RESULTS

64 UKA and 71 MOWHTO were found. Mean follow up was similar (54,05 ± 4,80 and 52,62 ± 3,91). A significant improvement was found in both groups for all outcomes at 6 months and at final follow up. PSM yielded 29 pairs. Patients treated with MOWHTO showed superior TAS scores at 6 months (3,41 ± 0,50 vs 3,10 ± 0,56; p < 0,05) and at final follow up (3,83 ± 0,80 vs 3,27 ± 0,59; p < 0,005). NRS and LKS were comparable between groups.

CONCLUSIONS

MOWHTO performed using an open wedge technique, with locking plate and a fast rehabilitation protocol guaranteed higher level of activity than UKA in patients older than 50 years. Difference is significant already at 6 months and last longer than 4 years.

LEVEL OF EVIDENCE

III.

Unicompartmental Knee Arthroplasty Has Lower Infection, Conversion, and Complication Rates Compared to High Tibial Osteotomy

INTRODUCTION

 Isolated medial knee osteoarthritis can be surgically treated with either unicompartmental knee arthroplasty (UKA) or high tibial osteotomy (HTO). Proponents of UKA suggest superior survivorship, while HTO offers theoretically improved alignment and joint preservation delaying total knee arthroplasty (TKA). Therefore, we compared complications in a large population of patients undergoing UKAs or HTOs. We specifically assessed 90 days, 1 year, and 2 years: (1) periprosthetic joint infection (PJI) rates, (2) conversion to TKA rates, as well as (3) complication rates.

METHODS

 A review of an administrative claims database was used to identify patients undergoing primary UKA (n = 13,674) or HTO (n = 1,096) from January 1, 2010 to December 31, 2019. Complication rates at 90 days, 1 year, and 2 years were compared between groups using unadjusted odds ratios (ORs) with 95% confidence intervals. Subsequently, multivariate logistic regressions were performed for PJI and conversion to TKA rates.

RESULTS

 At all time points, patients who underwent UKA were associated with lower rates of infection compared with those who underwent HTOs (all OR ≤ 0.51, all p ≤ 0.010). After 1 year, patients who received UKAs were found to have lower risk of requiring a conversion to a TKA versus those who received HTOs (all OR ≤ 0.55, all p < 0.001). Complications such as dislocations, periprosthetic fractures, and surgical site infections were found at lower odds in UKA compared with HTO patients.

CONCLUSION

 This study provides large-scale analyses demonstrating that UKA is associated with lower infection rates and fewer conversions to TKA compared with patients who have undergone HTO. Dislocations, periprosthetic fractures, and surgical site infections were also found to be lower among UKA patients. However, with careful patient selection, good results and preservation of the native knee are achieved with HTOs. Therefore, UKA versus HTO may be an important discussion to have with patients in an effort to lower the incidence of postoperative infections and complications.

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.

Unicompartmental knee arthroplasty is superior to high tibial osteotomy for the treatment of medial unicompartmental osteoarthritis: A systematic review and meta-analysis

BACKGROUND

Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are widely used for the treatment of medial unicompartmental knee osteoarthritis (OA). However, the best approach remains controversial. This study aimed to present a systematic review and a meta-analysis to directly compare the clinical outcomes between HTO and UKA. We hypothesized that the clinical outcomes after UKA and HTO would be similar.

METHODS

Electronic databases (Web of Science, PubMed, Embase, CENTRAL, and Biosis Preview) were searched for related studies published before November 30, 2021. Retrospective and prospective studies that directly compared the postoperative outcomes between UKA and HTO were included. Odds ratio (ORs) and 95% confidence interval (CIs) for complications, revision to total knee arthroplasty (TKA), and weighted mean difference (MD) and 95% CIs in range of motion (ROM), pain, walking speed and function score were evaluated. Two reviewers independently assessed the quality of the studies. Subgroup and sensitivity analyses were performed to explore the heterogeneity.

RESULTS

Twenty-three retrospective and 6 prospective studies were included. A total of 3004 patients (3084 knees) were evaluated for comparison. Complications (OR, 4.88, 95% CI: 2.92-6.86) were significantly greater in the HTO group than in the UKA group. Postoperative function scores including Lysholm score (MD, -2.78, 95% CI: -5.37 to -0.18) and Hospital for Special Surgery (HSS) score (MD, -2.80, 95% CI: -5.39 to -0.20) were significantly lower in the HTO group than the UKA group. The postoperative ROM was similar between HTO and mobile-bearing UKA (MD, -3.78, 95% CI: -15.78 to 8.22). However, no significant differences were observed between the HTO and UKA group in terms of postoperative pain, walking speed, and revision to TKA.

CONCLUSIONS

UKA is superior to HTO in minimizing complications and enhancing postoperative function scores. Mobile-bearing UKA has a similar ROM compared with HTO. Both HTO and UKA provide satisfactory clinical outcomes in terms of walking speed, relieving pain, and revision to TKA. UKA appears to be more suitable for the elderly, and both mobile-bearing UKA and HTO are viable surgical options for younger active individuals.

Comparison of joint awareness after medial unicompartmental knee arthroplasty and high tibial osteotomy: a retrospective multicenter study

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are established treatments for medial compartment osteoarthritis (OA) or osteonecrosis (ON) of the knee joint, and the predominance of either procedure is inconclusive. We compared the awareness of the knee after UKA and HTO using the Forgotten joint score-12 (FJS).

MATERIALS AND METHODS

This was a retrospective, multicenter study. Ninety-six knees of 90 patients who received UKA or HTO and were followed-up for at least 1 year were analyzed. Postoperative FJS was compared between the two groups and evaluated for the effect of patient-related factors and clinical outcomes. Multiple linear regression analysis was performed to predict FJS.

RESULTS

There was no significant difference in the FJS between the UKA and HTO groups (p = 0.24). FJS did not correlate with any of the patient-related factors. There was a correlation between the FJS and each item of the Knee Injury and Osteoarthritis Outcome Scores (KOOS) and Lysholm Knee Scoring Scale (LKS). In multiple linear regression analysis, lower BMI, the diagnosis of OA Kellgren-Lawrence (KL) grade ≥ 3, and ON were significant predictors of better FJS. In both groups, FJS was correlated with each item of the KOOS and LKS. Internal consistency in terms of Cronbach's alpha was excellent.

CONCLUSIONS

There was no significant difference in FJS between patients who underwent UKA and HTO. Lower BMI, the diagnosis of OA KL grade ≥ 3, and ON were significant predictors of better FJS.

Return to Sport After Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-analysis

Background:

Patients undergoing unicompartmental knee arthroplasty (UKA) often want to return to sport (RTS) after surgery. However, the time taken to RTS and proportion of patients who RTS after UKA remain unknown.

Purpose:

To determine the time to RTS and proportion of patients who RTS after UKA.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A search was performed using PubMed, Medline, Embase, SPORTDiscus and the Cochrane Library databases for clinical trials reporting on RTS after UKA published between database inception and September 2021. In addition, a manual search was performed of relevant sports medicine and orthopaedic journals, and bibliographies were reviewed for eligible trials. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were used to undertake this study.

Results:

This meta-analysis included 11 studies (749 patients) that reported on RTS after UKA. The proportion of patients returning to sports increased over time: 6 studies (432 patients) demonstrated an overall pooled proportion of 48.1% (95% CI, 36.3%-60.2%) of patients who returned to sport at 3 months after surgery, while 7 studies (443 patients) demonstrated an overall pooled proportion of 76.5% (95% CI, 63.9%-87.1%) of patients who returned to sport at 6 months after surgery. Overall, 92.7% (95% CI, 85.8%-97.4%) of 749 patients were able to RTS at 4 years after surgery. Overall excellent patient-reported functional outcomes scores and low risk of complications with RTS after UKA were reported.

Conclusion:

The authors found that 48.1% of patients were able to RTS at 3 months after surgery and 76.5% were able to RTS at 6 months after UKA. Pooled proportion analysis showed that >90% of patients undergoing UKA were able to RTS at 48 months after surgery. The majority of patients who were able to RTS after UKA did so at a lower level of intensity than their preoperative level. RTS after UKA was associated with good patient-reported functional outcomes scores and a low risk of complications.

A comparative study of 21,194 UKAs and 49,270 HTOs for the risk of unanticipated events in mid-age patients from the national claims data in South Korea

Background

Both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are well-established treatments for medial knee osteoarthritis (OA). However, over the past 20 years, results of comparisons of long-term survival rates and outcomes have remained controversial. Furthermore, in patients at the boundary age, from 50 to 70 years, considering age as a treatment indication, selecting a surgical method is difficult. Therefore, we aimed to investigate conversion rates to total knee arthroplasty (TKA) and perioperative adverse outcomes between the two surgical methods in mid-age patients.

Methods

We extracted data from the Korean National Health Insurance claims database. A total of 70,464 patients aged between 50 and 70 years, considered as mid-age patients were included in the final study population. We used a multivariable Cox proportional hazard regression model, adjusting for potential confounders such as age, sex, insurance type, region of residence, hospital type, comorbidities, and the Charlson comorbidity Index (CCI).

Results

Of the 70,464 patients, 21,194 were treated with UKA and 49,270 were treated with HTO. HTO showed a higher risk of revision than UKA at five, and 10 years and during the whole observation period. The incidence of deep vein thromboembolism, and surgical site infection was significantly higher in UKA than in HTO.

Conclusions

It is important to choose an appropriate surgical method considering that UKA has better results in terms of long-term survival rates but may have a higher incidence of various complications.

Unicompartmental Knee Arthroplasty: More Conversions, Fewer Complications Than Proximal Tibial Osteotomy in a Young Population

BACKGROUND

Patients with isolated medial compartment osteoarthritis requiring surgical intervention generally have two surgical options: unicompartmental knee arthroplasty (UKA) and proximal tibial osteotomy (PTO). Outcomes of reoperation rates and survivorship are important for counseling patients on treatment options.

METHODS

A retrospective, comparative cohort study was performed for a consecutive series of patients in the Military Health System who underwent either UKA or PTO between 2003 and 2018. All patients were between 18 and 55 years old and diagnosed with isolated medial compartmental arthritis. Cases with concurrent meniscal or cartilage procedures were included, while cases with concurrent ligament reconstruction were excluded. A minimum 2-year follow-up was required. The primary outcome was conversion to total knee arthroplasty, and the secondary outcome was reoperation for any reason.

RESULTS

A total of 383 procedures were performed for isolated medial compartment arthritis in 303 patients (UKA 270, PTO 113). A multivariate analysis showed that PTO was associated with decreased risk of conversion to TKA compared to UKA (P = .0364). However, the reoperation due to complications was significantly higher in the PTO group (21.2% vs 2.2%; P ≤ .01). The 5-year conversion rate was 13.7% for UKA and 3.5% for PTO (P = .0033) with an average time to conversion of 3.1 years for UKA and 2.9 years for PTO (P = .7805).

CONCLUSIONS

In young patients with isolated medial compartment arthritis, conversion rates to TKA are higher with UKA compared to PTO. However, overall reoperation rate is higher with PTO, secondary to complications and revision procedures. Overall survivorship is acceptable for both procedures.

Hypoalbuminemia Predicts Adverse Events following Unicompartmental Knee Arthroplasty

Hypoalbuminemia is a potentially modifiable risk factor associated with adverse events following total knee arthroplasty. The present study aimed to evaluate whether hypoalbuminemia similarly predisposes to adverse events following unicompartmental knee arthroplasty (UKA). Patients who underwent UKA during 2006-2018 were identified through the American College of Surgeons National Surgical Quality Improvement Program. Only patients with preoperative serum albumin concentration were included. Outcomes were compared between patients with and without hypoalbuminemia (serum albumin concentration < 3.5 g/dL). All associations were adjusted for demographic, comorbidity, and laboratory differences between populations. A total of 11,342 patients were identified, of whom 6,049 (53.3%) had preoperative serum albumin laboratory values available for analysis. After adjustment for potential confounders, patients with hypoalbuminemia had a greater than 2-fold increased probability for occurrence of any complication (7.02% vs. 2.23%, p = 0.009) and a 4-fold increased probability of receiving a blood transfusion (1.81% vs. 0.25%, p = 0.045). Among procedures performed as inpatients, mean postoperative length of stay (LOS) was longer in patients with hypoalbuminemia (2.2 vs. 1.8 days; p = 0.031). Hypoalbuminemia is independently associated with complications and increased LOS following UKA and a marker for patients at higher risk of postoperative complications. Patients should be screened for hypoalbuminemia and nutritional deficiencies addressed prior to UKA.

Functional results and survivorship after medial unicompartmental knee arthroplasty: a single center experience from Saudi Arabia

BACKGROUND

Isolated involvement of the medial compartment of the knee in degenerative disease is encountered in about 25% of patients with gonarthrosis. We aim to show that in a well-selected group of such patients, medial unicompartmental knee arthroplasty (UKA) is a good option.

OBJECTIVES

Review the functional outcomes of patients undergoing UKA and determine the long-term survivorship of the implants and complications of the procedure.

DESIGN

Analytical retrospective chart review.

SETTING

Academic tertiary care medical center and tertiary care private hospital in the western region of Saudi Arabia.

PATIENTS AND METHODS

We selected patients who underwent medial UKAs by the same surgeon between December 1988 and December 2009. The life table approach and the Kaplan-Meier statistical method were used to estimate the survival rate (5-30 years) with revision as the endpoint. Functional outcome scores were determined according to the Knee Society Clinical Rating System.

MAIN OUTCOME MEASURES

Change in performance scores for pain, walking, and range of movement. Survivorship of the implants with removal of the implant as the endpoint; post-operative complications.

SAMPLE SIZE

218 implants on 142 patients.

RESULTS

The survival rate of UKA was 94.7% at 10 years (95% CI 0.906-0.970), 80.9% at 20 years (95%CI 0.724-0.871), and 77.8% at 30 years (95%CI 0.669-0.855). The average grand total functional score increased from 61 (maximum 200) at 0 months to above 150 at ≥6 months.

CONCLUSION

UKA is a good option for isolated medial compartment gonarthrosis with excellent functional outcome and good survivorship in selected patients.

LIMITATION

Single center experience, retrospective. We lost 6.0% of patients during follow-up. Comparison with other treatment modalities is based on literature review and not on our own data.

CONFLICT OF INTEREST

None.

Comparison of Long-Term Survival Analysis Between Open-Wedge High Tibial Osteotomy and Unicompartmental Knee Arthroplasty

BACKGROUND

To compare unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO) in a long-term follow-up propensity score matching analysis.

METHODS

Patients who underwent UKA or OWHTO for unilateral medial unicompartmental osteoarthritis (OA) between 2004 and 2010 were included. The ROM, HSS score, KS score, WOMAC score, forgotten joint score, OA progression in patellofemoral and lateral compartments, and survivorship were compared within ten years of follow-up between 67 UKA and 67 OWHTO patients after propensity score matching for age, gender, body mass index, range of motion, and osteoarthritis (OA) grade.

RESULTS

At the last follow-up, there were no significant differences between the two groups in clinical outcomes, but the WOMAC score showed better results after UKA (13.1 in UKA vs 18.9 in OWHTO, P = .011). The OA progression also showed no significant difference between the two groups. After a 10-year follow-up, the survival rate was higher in UKA patients (96.2%) than in OWHTO patients (87.7%), with no statistical difference (P = .06).

CONCLUSION

UKA showed better clinical outcomes and OA progressions than OWHTO. The survival rate presented a superiority of 8.5% for the UKA group in the 10-year follow-up, without significant difference.

Unicompartmental bipolar osteochondral and meniscal allograft transplantation is effective for treatment of medial compartment gonarthrosis in a canine model

Osteochondral allograft (OCA) transplantation can restore large articular defects in the knee. Bipolar OCA transplantations for partial and whole joint resurfacing often have less favorable results than single-surface transplants. This study was designed to use a large animal model to test the hypothesis that unicompartmental bipolar osteochondral and meniscal allograft transplantation (BioJoint) would be as or more effective for treatment of medial compartment osteoarthritis (OA) compared to standard-of-care nonoperative treatment. OA was induced in one knee of each research hound (n = 8) using a meniscal release model and pretreatment assessments were performed. After 3 months, dogs were randomly assigned to either the control group (n = 4, no surgical intervention, daily nonsteroidal antiinflammatory drugs [NSAIDs]) or the BioJoint group (n = 4). Clinical, radiographic, and arthroscopic assessments were performed longitudinally and histopathology was evaluated at the 6-month endpoint. At study endpoint, functional, pain, and total pressure index measures, as well as radiographic and arthroscopic grading of graft appearance and joint health, demonstrated superior outcomes for BioJoints compared to NSAID controls. Furthermore, histologic assessments showed that osteochondral and meniscal transplants maintain integrity and integrated into host tissues. Clinical significance: The results support the safety and efficacy of unicompartmental bipolar osteochondral and meniscal allograft transplantation in a preclinical model with highly functional outcomes without early OA progression.

Return to Physical Activity After High Tibial Osteotomy or Unicompartmental Knee Arthroplasty: A Systematic Review and Pooling Data Analysis

BACKGROUND

The 2 most common definitive surgical interventions currently performed for the treatment of medial osteoarthritis of the knee are medial opening wedge high tibial osteotomy (HTO) and medial unicompartmental knee arthroplasty (UKA). Research exists to suggest that physically active patients may be suitably indicated for either procedure despite HTO being historically indicated in active patients and UKA being more appropriate for sedentary individuals.

PURPOSE

To help consolidate the current indications for both procedures regarding physical activity and to ensure that they are based on the best information presently available.

STUDY DESIGN

Systematic review.

METHODS

A search of the literature via the MEDLINE, Embase, and PubMed databases was conducted independently by 2 reviewers in accordance with the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. Studies that reported patient physical activity levels with the Tegner activity score were eligible for inclusion. Patient demographics, operative variables, and patient-reported outcome scores were abstracted from the included studies.

RESULTS

Thirteen eligible studies were included, consisting of 401 knees that received HTO (399 patients) and 1622 that received UKA (1400 patients). The patients' mean age at surgery was 48.4 years for the HTO group and 60.6 years for the UKA group. Mean follow-up was 46.6 months (HTO) and 53.4 months (UKA). All outcome scores demonstrated an equal or improved score for activity and knee function regardless of the operation performed. Operative variables during HTO had a larger effect on outcome than during UKA.

CONCLUSION

Patients who underwent HTO were more physically active pre- and postoperatively, but patients undergoing UKA experienced an overall greater increase in their physical activity levels and knee function according to Tegner and Lysholm scores. Activity after HTO may be influenced by operative factors such as the implant used and the decision to include a graft material in the osteotomy gap, although this requires further research. Some studies found that patients were able to return to physical activity postoperatively despite having an age or body mass index that would traditionally be a relative contraindication for HTO or UKA.

Medial Osteoarthritis in an ACL-Deficient Knee: A Critical Analysis Review

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In anterior cruciate ligament (ACL)-deficient knees, treatment of medial compartment osteoarthritis (OA) that is refractory to nonoperative modalities is a controversial subject.

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Currently available treatment options include unicompartmental knee arthroplasty (UKA) with or without ACL reconstruction (ACLR), high tibial osteotomy (HTO) with or without ACLR, and total knee arthroplasty (TKA).

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Each treatment option has its own risks and benefits, and the evidence that is reviewed in this article suggests that patient characteristics guide treatment selection.

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Future high-quality prospective studies that directly compare all 3 of the modalities are necessary to determine the best treatment option for different patient populations.

A Comparison of Mobile- and Fixed-Bearing Unicompartmental Knee Arthroplasties in the Treatment of Medial Knee Osteoarthritis: A Systematic Review and Meta-analysis of 1,861 Patients

Many studies have compared mobile-bearing (MB) and fixed-bearing (FB) unicompartmental knee arthroplasties (UKAs) in patients with unicompartmental knee osteoarthritis (OA). The present systematic review and meta-analysis examined the differences in the clinical and radiological outcomes of MB UKA and FB UKA. PubMed, EMBASE, and Cochrane databases, as well as Google Scholar were searched for relevant studies. Randomized controlled trials (RCTs) and cohort studies that compared MB UKA and FB UKA were included. The weighted mean difference in the knee scores and range of motion (ROM) as well as the summary odds ratio of postoperative mechanical axis alignment, radiolucency, revision rate, and complications were calculated in the MB UKA and FB UKA groups. Finally, 2 RCTs and 11 cohort studies that involved 1,861 patients (1,996 knees) were included. The FB UKA group showed better postoperative Knee Society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and ROM than the MB UKA group. However, the MB UKA group had more knees with a neutral limb alignment and a lower incidence of polyethylene wear than the FB UKA group. No significant differences were observed between the groups with respect to radiolucency, revision rate, and complications, such as arthritis progression, aseptic loosening, and postoperative pain. This meta-analysis has demonstrated that both prostheses provided excellent clinical outcomes and survivorship in patients with unicompartmental knee OA. The MB UKA group achieved the expected postoperative neutral limb alignment as compared with the FB UKA group, while the FB UKA group showed higher knee scores and superior ROM than the MB UKA group. Limited evidence is currently available; therefore, the results of our meta-analysis should be interpreted with caution.

Risk of a complete exchange or failure in total knee arthroplasty and unicompartmental knee arthroplasty: a nationwide population-based cohort study from South Korea

PURPOSE

Few large-scale studies using adjusted data from national registries have explored the risk factors of subsequent revision in patients with unicompartmental knee arthroplasty (UKA) compared to those with total knee arthroplasty (TKA). We investigated the incidence rate and risk factors of subsequent revision in patients with UKA and TKA.

METHODS

We enrolled all patients who had undergone TKA or UKA as the primary surgical procedure without histories of having undergone either procedure during the preceding 2 years. Matched Cox regression models were used to compare the risks of revision between groups after propensity score matching. Revision was defined as conversion to revision TKA after primary TKA and conversion to TKA after UKA.

RESULTS

The study enrolled 418,806 TKA patients and 446,009 UKA patients. The risk of revision during the entire study period was higher for patients with UKA than for patients with TKA (adjusted hazard ratio [HR] 1.22, 95% confidence interval [95% CI]: 1.10-1.36). The Kaplan-Meier 8-year survival was 98.7% in the TKA group and 96.7% in the UKA group. Patients with UKA were at an increased risk of revision in cases of advanced age (70-79 years, HR 1.40, 95% CI: 1.15-1.71), female sex (HR 1.32, 95% CI: 1.16-1.49), the presence of chronic obstructive pulmonary disease (COPD) (HR 1.27, 95% CI: 1.05-1.54), the presence of peptic ulcer disease (PUD) (HR 1.34, 95% CI: 1.11-1.61) compared to patients with TKA. In patients with hemiplegia, however, UKA were associated with a lower risk of subsequent revision (HR 0.25, 95% CI: 0.07-0.94).

CONCLUSION

The risk of a complete exchange or failure was higher for patients with UKA than for patients with TKA. The most significant independent risk factors for subsequent a complete exchange or failure in patients with UKA were advanced age (70-79 years), female sex, and the presence of comorbidities such as COPD and PUD.

Obesity does not adversely impact the outcome of unicompartmental knee arthroplasty for osteoarthritis: a meta-analysis of 80,798 subjects

BACKGROUND

Patients with end-stage single compartment osteoarthritis benefit from the less invasive unicompartmental knee arthroplasty (UKA). With increasing financial restraints, some healthcare services have set specific BMI cut-offs when determining patient eligibility for knee arthroplasty due to perceived obesity-related complications. The aim of this systematic review is to determine the effect obesity has on outcomes following UKA, and thus elucidate whether obesity should be a contraindication for UKA.

METHODS

A PRISMA systematic review was conducted using five databases (MEDLINE, EMBASE, Cochrane, PubMed and Web of Science) to identify all clinical studies that examined the effect of obesity on outcomes following UKA. Quantitative meta-analysis was carried out using RevMan 5.3 software. Quality assessment was carried out using the Critical Appraisal Skills Programme (CASP) checklist.

RESULTS

Thirty studies, including a total of 80 798 patients were analysed. The mean follow- up duration was 5.42 years. Subgroup meta-analyses showed no statistically significant difference following UKA between patients cohorts with and without obesity in overall complication rates (95% CI, P = 0.52), infection rates (95% CI, P = 0.81), and revision surgeries (95% CI, P = 0.06). When further analysing complications, no differences were identified in minor (95% CI, P = 0.23) and major complications (95% CI, P = 0.68), or venous thromboembolism rates (95% CI, P = 0.06). When further analysing revision surgeries, no differences were identified for revisions specifically for infection (95% CI, P = 0.71) or aseptic loosening (95% CI, P = 0.75).

CONCLUSIONS

This meta-analysis shows that obesity does not result in poorer post-operative outcomes following UKA and should not be considered a contraindication for UKA. Future studies, including long-term follow-up RCTs and registry-level analyses, should examine factors associated with obesity and consider stratifying obesity to better delineate any potential differences in outcomes.

Better outcomes and reduced failures for arthroplasty over osteotomy for advanced compartmental knee osteoarthritis in patients older than 50 years

BACKGROUND

Both compartmental knee arthroplasty (CKA) and open-wedge high tibial osteotomy (HTO) may be used to treat patients older than 50 years of age with advanced compartmental osteoarthritis (OA) secondary to leg axis deformities. A meta-analysis was conducted to clarify the role of open-wedge HTO versus CKA for patients older than 50 years with advanced compartmental knee OA. The present investigation aimed to analyse the clinical outcomes, implant failure and survivorship.

METHODS

This meta-analysis was performed in accordance with the PRISMA guidelines. In September 2020, the main online databases were accessed. All clinical trials comparing the outcomes of open-wedge HTO versus CKA for compartmental knee OA were considered. Data analysis was performed through the Review Manager Software 5.3 (the Nordic Cochrane Collaboration, Copenhagen). Implant survivorship was analysed with a Kaplan-Meier (KM) curve that was performed using the STATA/MP software (StataCorp, College Station, TX).

RESULTS

Data from 618 (HTO, 307; CKA, 311) patients were collected. Good baseline comparability among patient age, BMI and gender was detected. The Tegner Activity Scale was higher in the CKA group (P = 0.04), as were the Lysholm score (P = 0.001), the International Knee Documentation Committee (P = 0.0001) and the Knee injury and Osteoarthritis Outcome Score (P = 0.05). At a mean follow-up of 5 years, revisions were less in the CKA cohort (OR, 2.27; P = 0.004). The Kaplan-Meier curve evidenced longer implant survivorship in favour of the CKA group (P = 0.01).

CONCLUSION

In patients older than 50 years of age with compartmental knee OA secondary to frontal axis leg deformities, CKA performed better than open-wedge HTO.

Therapeutic Effects Comparison and Revision Case Analysis of Unicompartmental Knee Arthroplasty and Open Wedge High Tibial Osteotomy in Treating Medial Knee Osteoarthritis in Patients Under 60 years: A 2-6-year Follow-up Study

Objective

To evaluate the therapeutic effects and revision cases of unicompartmental knee arthroplasty (UKA) and open wedge high tibial osteotomy (OWHTO) in treating medial knee osteoarthritis (MKOA) in patients under 60 years.

Methods

The present retrospective study included a total of 192 patients who were diagnosed with MKOA and treated by UKA or OWHTO in the Second Affiliated hospital of Xi'an Jiaotong University and Xi'an Honghui Hospital between December 2012 and December 2016. Among these patients, 83 were treated by UKA (17 men and 66 women, aged 53.7 ± 5.2 years) and 109 were treated by OWHTO (23 men and 86 women, aged 51.8 ± 6.9 years). Patients were followed up at 1, 3, 6, and 12 months for the first year postoperation, and every 6 months from the second year postoperation. Basic data, perioperative data, hospital for special surgery (HSS) score, visual analogue pain score (VAS), low‐impact recovery, and revision cases of the patients were evaluated.

Results

The average follow‐up periods of the UKA group and the OWHTO group were 39.3 ± 11.2 months and 40.2 ± 13.5 months, respectively. No significant difference was found in the basic data of the two groups (P ≥ 0.05). The operative time, incision length, and dominant blood loss of the UKA group was less than those of OWHTO group by 19.6%, 10.7%, and 35.1%, respectively, and the differences were significant (P < 0.05), while no significant difference was found in postoperative in‐bed time (P ≥ 0.05). The HSS scores of the UKA group at 1 and 3 months postoperation were higher than those of the OWHTO group by 5.1% and 3.9% (P < 0.05), while no differences were found from 6 months postoperation (P ≥ 0.05). The VAS score of the UKA group 1 month postoperation was lower than that of the OWHTO group by 12.2% (P < 0.05), while no differences were found from 3 months postoperation (P ≥ 0.05). One year after the operation, most patients in both groups could not achieve ideal recovery in low‐impact sports, and no significant differences were found (P < 0.05). The sport in which most patients could not achieve ideal recovery was mountain climbing. No revision cases occurred in the OWHTO group, while two revisions occurred in the UKA group.

Conclusion

Candidates for UKA should be chosen carefully and the current indications and contraindications raised by Goodfellow should be modified.

[Research progress in unicompartmental knee arthroplasty]

OBJECTIVE

To summarize the clinical application and research progress in unicompartmental knee arthroplasty (UKA).

METHODS

The literature related to UKA in recent years was reviewed and the emerging indications, implant options, comparisons between other surgical techniques, and recent advances were summarized.

RESULTS

Clinical studies show that UKA has many advantages, such as less trauma, faster recovery, and fewer postoperative complications. At present, the operative indication has been expanded. The body mass index more than 25 kg/m 2, less than 60 years old, patellofemoral arthritis, and anterior cruciate ligament dysfunction are no longer considered as contraindications. The prosthesis type in UKA should be selected according to the patient's condition. In recent years, the robot-assisted UKA can effectively improve the effectiveness, improve patient satisfaction, and reduce postoperative complications.

CONCLUSION

With the development of surgical techniques, designs of prosthesis, and the robotic technology, UKA would be further applicated. As more long-term data on UKA become available, it will further guide clinicians in counseling patients on whether UKA should be performed.

What Factors Predict Patient Dissatisfaction After Contemporary Medial Opening-Wedge High Tibial Osteotomy?

BACKGROUND

Although current advances in surgical techniques have improved outcomes of the medial opening-wedge high tibial osteotomy (MOWHTO), the factors associated with patient dissatisfaction remain unclear. Thus, the purpose of this study is to identify risk factors for patient dissatisfaction following contemporary MOWHTO.

METHODS

We retrospectively reviewed prospectively collected data on 140 consecutive MOWHTO patients using an anatomical locking plate with a minimum follow-up of 2 years. Patient demographics, pain Visual Analogue Scale, Western Ontario and McMaster Universities Osteoarthritis Index, Kellgren-Lawrence (K-L) grade, activity level, articular cartilage and meniscal status, hip-knee-ankle angle, change in alignment, and postoperative weight-bearing line ratio were recorded. Patients were categorized using the New Knee Society Score into satisfied (satisfaction score ≥20) or dissatisfied (satisfaction score <20) groups. Patient and surgical factors were compared between the groups by the identified predictors. Multiple logistic regression analysis was used to analyze risk factors, including K-L grade IV medial osteoarthritis (OA), preoperative pain Visual Analogue Scale, total Western Ontario and McMaster Universities Osteoarthritis Index score, postoperative hip-knee-ankle angle, change in alignment, and partial meniscectomy.

RESULTS

Of the 140 patients, 24 (17.1%) were dissatisfied with their results. Multiple logistic regression analysis showed that only K-L grade IV medial OA was statistically associated with patient dissatisfaction following MOWHTO (odds ratio 4.911, 95% confidence interval 1.820-13.256, P < .01).

CONCLUSION

Severe medial OA was an independent risk factor for dissatisfaction following contemporary MOWHTO using a rigid locking plate. Surgeons should take this into consideration when counseling and choosing surgical options in MOWHTO candidates with severe medial OA.

LEVEL OF EVIDENCE

Level III.

High tibial osteotomy in obese patients: Is successful surgery enough for a good outcome?

INTRODUCTION

Knee osteoarthritis is the most common articular pathology. High tibial osteotomy (HTO) is a frequently used treatment procedure in medial osteoarthritis of the knee joint. We aimed to reveal factors that affect clinical and radiologic outcomes by evaluating the efficacy of HTO in patients with BMI ≥30 kg/m2 who were not appropriate for prostheses considering their activity, degree of pain, and age.

MATERIAL AND METHOD

HTO was performed using the medial open wedge technique who presented to the orthopedics polyclinic with symptoms of knee pain, whose BMI was over 30 kg/m2. All patients were diagnosed as having mechanical axis deviation and isolated medial compartmental arthrosis between 2013 and 2015.The clinical and radiologic follow-ups of patients were performed on day 45, at month 3, month 6, and after 1 year. The knee scoring system from the American Knee Society (AKS), and range of motion (ROM) were used in the functional evaluation of the patients.

RESULT

Eighteen patients were included in the study. Thirteen patients (72.2%) were women and 5 (27.8%) were men. Preop axis score was found significantly lower compared with the axis scores at postop month 6 and in final follow-up, the postoperative final follow-up axis score was found significantly lower than the axis score at month 6 (p < 0.05).

CONCLUSION

We anticipated in our study that the better outcomes obtained in the early period might be maintained for longer in parallel with weight loss and decreased BMI in the postoperative period. We believe that it is important to perform complication-free HTO with the correct technique, and by organizing a rapid and systematic weight loss process.

Long-term survival is similar between closed-wedge high tibial osteotomy and unicompartmental knee arthroplasty in patients with similar demographics

PURPOSE

Long-term clinical and radiographic results and survival rates were compared between closed-wedge high tibial osteotomy (HTOs) and fixed-bearing unicompartmental knee arthroplasty (UKA) in patients with similar demographics.

METHODS

Sixty HTOs and 50 UKAs completed between 1992 and 1998 were retrospectively reviewed. There were no significant differences in pre-operative demographics. The mean follow-up period was 10.7 ± 5.7 years for HTO and 12.0 ± 7.1 years for UKA (n.s.). The Knee Society knee and function scores, WOMAC, and range of motion (ROM) were investigated. The mechanical axis and femorotibial angle were evaluated. Kaplan-Meier survival analysis was performed (failure: revision to TKA) and the failure modes were investigated.

RESULTS

Most of the clinical and radiographic results were not different at the last follow-up, except ROM; ROM was 135.3° ± 12.3° in HTO and 126.8° ± 13.3° in UKA (p = 0.005). The 5-, 10-, 15-, and 20-year survival rates were 100%, 91.0%, 63.4%, and 48.3% for closed-wedge HTO, respectively, and 90.5%, 87.1%, 70.8%, and 66.4% for UKA (n.s.). The survival rate was higher than that for UKA until 12 years post-operatively but was higher in UKAs thereafter, following a remarkable decrease in HTO. The most common failure mode was degenerative osteoarthritic progression of medial compartment in HTO and femoral component loosening in UKA.

CONCLUSIONS

Long-term survival did not differ significantly between closed-wedge HTO and fixed-bearing UKA in patients with similar pre-operative demographics and knee conditions. The difference in post-operative ROM and failure mode should be considered when selecting a procedure.

LEVEL OF EVIDENCE

III.