How to manage and avoid revision after unicompartmental knee arthroplasty?

Abstract

The article by Zhao et al presents a retrospective case series on the reasons for initial revision after unicompartmental knee arthroplasty (UKA). Clarifying the reasons that may cause UKA revision can further reduce the rate of revision UKA, focusing on gasket dislocation, osteophytes, intra-articular loose bodies, and tibial prosthesis loosening. This article provides valuable insights, not only by detailing the revision status of 13 patients who underwent revision after initial UKA but also by providing a comprehensive analysis of the incidence of revision after initial UKA. By reviewing and analyzing the causes, they established references for the early detection of risk factors for revision in clinical practice and for formulating surgical strategies and rehabilitation programmes. This commentary emphasizes the need for a meticulous understanding and an analysis of the revision rate following initial UKA and related management strategies. The implant rates, regional variation, and benefits of uncemented Oxford UKA have been explored, particularly in terms of bone preservation, appropriate surgical techniques, and weight management to control complications and improve patient prognosis.

Key Words: Unicompartmental knee arthroplasty; First revision; Incidence; Complications; Editorial

Core Tip: Unicompartmental knee arthroplasty (UKA) revision risks vary based on factors such as lateral vs medial approach, total knee arthroplasty conversion, and implant type. Uncemented Oxford UKA, bone preservation, and appropriate surgical techniques contribute to lower revision rates. Obesity increases the risk of revision following total knee arthroplasty, particularly in the short term.

INTRODUCTION

We read with interest the recent article by Zhao et al[1], a retrospective case study summarized the reasons that the first revision after unicompartmental knee arthroplasty (UKA). They employed an electronic medical record system to record and analyse the baseline data, including patients and comprehensively analysed the reasons that revision after UKA among the included patients based on their imaging data, medical histories, physical examination results, chemical test results, intraoperative conditions, and pathological findings. The author proves that the initial revision after UKA is mainly due to dislocation of the joint pad, intra-articular loosening, osteophyte and tibial prosthesis loosening. Avoiding the above factors can significantly reduce the incidence of postoperative revision in UKA, reduce medical burden, and improve patient satisfaction. and comprehensively analyzed the factors leading to revision in UKA patients, The case study is based on clinical evidence, authentic and credible, with accompanying images, which is not common in other studies. However, the paper did not mention renovation rate and management strategies, and addressing those issue would help to gain a broader understanding of potential complex situations

MANAGEMENT AND PREVENTION STRATEGIES TO AVOID REVISION AFTER PRIMARY REVISION UKA

Studies have indicated that total knee arthroplasty (TKA) converted from medial UKA has a three fold higher risk of revision[2]. A prospective observational cohort study conducted from September 2016 to December 2017 on patients scheduled for primary knee arthroplasty revealed varying 2-year cumulative revision rates across different hospitals[3]. This underscores the need for a more nuanced understanding of the indications for lateral UKA revision, as lateral UKA has shown higher revision rates than medial UKA[4].

The controversy surrounding implant rates and UKA revision rates is further discussed in the literature. The report emphasizes the variability in revision rates following primary knee arthroplasty, influenced by factors such as country, region, and hospital[5]. However, in hospitals with different revision rates, the measurement results reported by patients before primary knee replacement surgery are comparable. Further exploration is warranted to determine whether the rate of UKA revision varies significantly by country, region, and hospital.

In addition, a comparison between cemented and uncemented Oxford UKA groups reveals that the latter is associated with a lower revision rate and fewer radiolucent lines after a minimum 2-year follow-up[6]. The uncemented group also exhibited a significantly shorter operation time, emphasizing the potential benefits of this approach. Orthopedic surgeons should prioritize bone preservation during primary UKA, as highlighted by the greater revision rate observed for revision TKA after UKA, requiring more revision implants[7]. Utilizing an appropriate surgical technique, navigation-assisted revision from UKA to TKA can produce clinical and radiological results comparable to primary navigation-assisted TKA[8]. Moreover, obesity, defined by increased body mass index (BMI), has been consistently associated with higher revision rates following TKA[9]. In the population with the highest BMI and weight, the risk of infection is almost twice as high. The study also suggests that BMI, weight, and height may be associated with different types of risk adjusted after TKA, with obesity particularly impacting short-term revision risks[10].

CONCLUSION

In conclusion, compared to primary TKA, TKA converted from medial UKA has a significantly higher risk of revision. Measures such as uncemented Oxford UKA, bone preservation, appropriate surgical techniques, and weight management should be considered to control complications and improve patient outcomes. Further research is warranted to explore variations in UKA revision rates across different settings, and surgeons should be vigilant in counseling patients about potential risks and management strategies.