A cost comparison of unicompartmental and total knee arthroplasty

A Comparison of Mobile and Fixed-Bearing Unicompartmental Knee Arthroplasty at a Minimum 10-Year Follow-up

BACKGROUND

The long-term survivorship and functional outcomes of the mobile-bearing (MB) compared to the fixed-bearing (FB) unicompartmental knee arthroplasty (UKA) implant design remain a topic of debate. The aim of the current study was to compare the survivorship and functional outcomes of MB and FB UKA at a minimum 10-year follow-up.

METHODS

We retrospectively reviewed 106 consecutive medial UKAs (89 patients) from our institution with a minimum 10-year follow-up. The 38 MB and 68 FB knees had follow-up of 14.2 years (12.9-15.5) and 11.5 years (10.2-15.1), respectively. Validated patient-reported outcomes and radiographs were evaluated as were etiology, timing, and complexity of revision. Kaplan-Meier 10-year survival was calculated with revision to total knee arthroplasty as the end point.

RESULTS

The 10-year survival was 82.9% (95% confidence interval [CI] 65.8-91.9) for MB and 90.9% (95% CI 79.4-96.2) for FB UKA (P = .102), and 88.0% (95% CI 79.3-93.2) for the entire cohort. Patient outcomes were similar between groups, as were timing and etiologies for revision to total knee arthroplasty. One-third of revisions required either stems or tibial augments, and of these, all were of MB design.

CONCLUSION

Survival and functional outcomes were similar between MB and FB designs. One-third of revisions required either stems or augments, all were of MB design.

Unicompartmental knee replacement - Current perspectives

Unicompartmental knee replacement (UKR) is an effective treatment for end-stage, symptomatic unicompartmental osteoarthritis of the knee. However, certain aspects of the procedure are still debated. These areas of discussion include patient selection criteria, implant design and the discrepancy in survival rates between national registries and independent case series. These may contribute in limiting the more widespread acceptance of unicompartmental knee replacement. The aim of this paper is to review the up-to-date evidence on UKR and discuss the most relevant controversies regarding this procedure.

Return to sports and quality of life after high tibial osteotomy in patients under 60 years of age

INTRODUCTION

Since knee osteoarthritis is unicompartmental in most cases, a knee osteotomy is the most logical solution to limit degeneration of the arthritic compartment, thereby delaying knee arthroplasty. Younger patients have high functional demands. The purpose of this study was to evaluate the return to sports and quality of life after high tibial osteotomy (HTO) in athletic patients less than 60 years of age. The hypothesis was that patients can return to sports within 1 year of HTO.

MATERIALS AND METHODS

A single-centre, retrospective study was performed of 30 patients under 60 years of age with medial tibiofemoral osteoarthritis and no history of surgery or trauma who underwent HTO between January 2014 and August 2015. The primary endpoint was the return to sport at 1 year based on the Tegner score. Secondary endpoints were the subjective IKDC score, Lysholm score and SF-36.

RESULTS

The mean follow-up was 1.3 years [1-1.5] and no patients were lost to follow-up. All the patients had returned to sports at 1 year: 73.3% at their pre-surgery level (before the pain started) and 23.3% at a higher level. Their quality of life was significantly improved according to the SF-36 questionnaire: 65.3% pre-operatively compared with 72.5% postoperatively (P=0.01). The preoperative and 1-year postoperative scores were comparable for the Tegner (P=0.167), IKDC (P=0.093) and Lysholm (P=0.061).

CONCLUSION

HTO allows patients to resume their sports activities within 1 year of surgery and significantly improves their quality of life.

LEVEL OF EVIDENCE

Level IV - Retrospective cohort study.

Robotic-arm assisted partial knee arthroplasty: a single centre experience

BACKGROUND AND AIM OF THE WORK

UKA has proven to be an effective surgical procedure, but its survivorship is still negatively affected by inaccuracy in component component positioning, implant and limb alignment. Robotic surgery has been introduced in order to minimize such technical errors. The aim of the present paper was to evaluate clinical and surgical outcomes after a 3 years' experience of robotic assisted UKA with the Mako Robotic Arm.

METHODS

Seventy-three patients undergoing  UKA with robotic instrumentation (65 medial UKAs, 8 lateral UKAs) and with a clinical follow-up of 3 -37 months were included in the present study. A complete clinical evaluation with KOOS, FJS-12 and SF-12 was administered to all patients pre and post operatively. Post-operative HKA angle and surgical time were also recorded.

RESULTS

Mean post-operative KOOS score was 81.32 (SD 17.19), while the mean FJS-12 score was 75.51 (SD 30.12) and the mean SF-12 Physical Score 42.25 (SD 9.97). 91% to 88% of post-operative results were considered satisfactory. Only 1 UKA failure was reported (1.3%) caused by peri-prosthetic infection. In medial UKAs mean postoperative HKA angle in extension was 3.9° varus (SD 2.5°), with no case of overcorrection; in lateral UKAs mean postoperative HKA angle in extension was 1.9° valgus (SD 1.9°) with 1 case (13%) of overcorrection. Mean skin to skin surgical time decreased from 83.2 minutes (SD 13.0) to 70.0 minutes (SD 10.9) along the learning curve.

CONCLUSIONS

Robotic UKA has provided an improvement both in clinical and technical results, determining satisfactory clinical outcomes and a low risk of post-operative complications.