Patellar resurfacing in knee arthroplasty: A comprehensive review and meta-analysis

Abstract

BACKGROUND

Patellar resurfacing in knee arthroplasty remains a contentious issue, with various strategies including routine, selective, and non-resurfacing approaches. This review and meta-analysis aim to assess the incidence of patellar resurfacing, revision rates, patient satisfaction, and relevant knee scores associated with each method.

AIM

To determine the comparative effectiveness of routine, selective, and non-resurfacing strategies in patellar resurfacing within knee arthroplasty by evaluating incidence rates, revision rates, patient satisfaction, and knee function scores.

METHODS

A systematic review spanning from 1990 to 2024 was conducted using PubMed, Embase, and Cochrane Library databases. Studies reporting on the incidence of patellar resurfacing, revision rates, patient satisfaction, and relevant knee scores were included. Data from esteemed world registries such as the Australian Orthopaedic Association National Joint Replacement Registry, the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man and Danish Knee Arthroplasty Registry among others, were meticulously examined. Meta-analysis was employed to derive pooled estimates and 95% confidence intervals.

RESULTS

Analysis of data sourced from diverse world registries and literature sources unveiled significant disparities in the incidence of patellar resurfacing across different geographic regions and healthcare institutions. For instance, the incidence of routine patellar resurfacing ranged from 60% to 90% in some regions, while in others, it was as low as 30% to 50%. The meta-analysis indicated that routine resurfacing was associated with a lower revision rate of 3.5% (95%CI: 2.8%-4.2%) compared to non-resurfacing approaches, which exhibited a higher revision rate of 6.8% (95%CI: 5.5%-8.1%). Patient satisfaction outcomes showed variability, with routine resurfacing demonstrating higher mean satisfaction scores in functionality, pain relief, and stability categories.

CONCLUSION

The findings underscore the complexity of patellar resurfacing in knee arthroplasty and highlight the need for continued research to refine clinical practice. Future studies should prioritize prospective randomized controlled trials comparing different patellar resurfacing techniques using standardized outcome measures. Longitudinal studies with extended follow-up periods are necessary to evaluate the long-term outcomes and durability of various patellar resurfacing strategies. Collaborative efforts among multidisciplinary teams will be essential to conduct high-quality research that can provide actionable insights and improve patient outcomes.

Key Words: Patellar resurfacing; Patellar non-resurfacing; Knee arthroplasty; Knee pain; Revision arthroplasty

Core Tip: This systematic review and meta-analysis provide a comprehensive assessment of patellar resurfacing in knee arthroplasty, examining incidence, revision rates, and patient satisfaction across routine, selective, and non-resurfacing strategies. Routine resurfacing was associated with lower revision rates and higher patient satisfaction compared to non-resurfacing, but significant regional and institutional variability highlights the need for tailored, patient-specific approaches. Future research should focus on high-quality, prospective trials with standardized outcomes to clarify the long-term benefits and risks of different resurfacing strategies, guiding optimal clinical decisions in knee arthroplasty.

INTRODUCTION

Knee arthroplasty is a prevalent orthopaedic intervention for end-stage knee osteoarthritis, with patellar management representing a critical component. The decision regarding whether to resurface the patella routinely, selectively, or not at all is influenced by several multifactorial considerations and has sparked significant debate within the orthopaedic community. There are Specific Controversies and Differing Viewpoints: Routine Resurfacing vs Non-Resurfacing: Proponents of Routine Resurfacing: Advocate for resurfacing the patella in all cases, citing evidence that it can reduce the incidence of anterior knee pain, enhance overall knee function, and lower the risk of revision surgery[1]. Studies supporting this approach have shown that patients often report higher satisfaction levels, improved pain relief, and better functional outcomes[2-23] (Table 1). Opponents of Routine Resurfacing: Argue that routine resurfacing can introduce complications such as patellar fractures, instability, maltracking, and increased wear of the prosthetic components[3]. They suggest that these potential risks may outweigh the benefits, particularly in patients without preexisting patellar pathology[2-23]. Selective Resurfacing: Advocates for Selective Resurfacing: Propose a middle ground where the decision to resurface is made intraoperatively based on specific criteria such as the condition of the patellar cartilage, patient anatomy, and intraoperative findings[5]. This approach aims to balance the benefits and risks, potentially reducing unnecessary resurfacing while still addressing cases where resurfacing may provide significant advantages[1-23]. Critics of Selective Resurfacing: Point out that selective resurfacing can lead to inconsistent outcomes, as the decision-making process may vary significantly between surgeons and institutions. This variability can result in a lack of standardization and difficulty in predicting patient outcomes[7]. Non-Resurfacing: Proponents of Non-Resurfacing: Argue that avoiding patellar resurfacing altogether can eliminate the risks associated with the procedure. They believe that advancements in implant design and surgical techniques can achieve satisfactory outcomes without the need for resurfacing, especially when combined with other strategies to address anterior knee pain[8]. Opponents of Non-Resurfacing: Highlight studies indicating higher revision rates and persistent anterior knee pain in patients who do not undergo patellar resurfacing[2-23]. They argue that non-resurfacing can lead to secondary surgeries, increased healthcare costs, and prolonged patient discomfort[10]. This review endeavours to shed light on the outcomes linked to these distinct patellar resurfacing strategies, aiming to provide a comprehensive analysis of their respective benefits and drawbacks. By examining the latest evidence and data from various studies and registries, this review seeks to inform clinical practice and guide decision-making in knee arthroplasty.

Table 1 Revision rates associated with different patellar resurfacing approaches, (%)¹.

Ref.	Routine resurfacing	Selective resurfacing	Non-resurfacing
Smith et al[2] (2015)	4.2	4.8	6.5
Khan et al[19] (2016)	3.5	4.0	5.8
Delanois et al[15] (2017)	5.1	5.5	7.3
Yi et al[5] (2015)	4.8	5.2	6.9
Li et al[20] (2019)	3.9	4.4	6.1

¹The table shows that across all five studies, routine resurfacing consistently has the lowest revision rates compared to selective resurfacing and non-resurfacing. Selective resurfacing generally has a moderate revision rate, while non-resurfacing shows the highest revision rates in all studies. These findings suggest that routine patellar resurfacing may lead to better long-term outcomes in terms of fewer revision surgeries needed, compared to selective or non-resurfacing strategies.

MATERIALS AND METHODS

A systematic review was conducted to analyze literature from 1990 to 2024, utilizing PubMed, Embase, and the Cochrane Library databases. The review aimed to include studies reporting on the incidence of patellar resurfacing, revision rates, patient satisfaction, and relevant knee scores. Additionally, data from reputable world registries, such as the Australian Orthopaedic Association National Joint Replacement Registry[11], the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man[12], and Danish Knee Arthroplasty Registry[13], among others, were meticulously examined.

Inclusion criteria

Study types: Randomized controlled trials (RCTs), cohort studies, case-control studies, and registry reports.

Population: Patients undergoing knee arthroplasty.

Interventions: Studies examining routine, selective, or non-resurfacing of the patella.

Outcomes: Incidence of patellar resurfacing, revision rates, patient satisfaction, and relevant knee scores (e.g., functionality, pain relief, stability).

Publication dates: Studies published between January 1, 2000, and December 31, 2024.

Language: Studies published in English.

Exclusion criteria

Study types: Case reports, reviews, and editorials.

Population: Studies focusing on animal models or cadaveric specimens.

Incomplete data: Studies with insufficient data on key outcomes or without a clear definition of patellar resurfacing strategies.

Duplicate data: Studies with overlapping patient populations from the same registry or institution. Meta-analysis techniques were employed to derive pooled estimates and 95% confidence intervals for the outcomes of interest.

RESULTS

Analysis of data sourced from diverse world registries and literature sources unveiled significant disparities in the incidence of patellar resurfacing across different geographic regions and healthcare institutions. For instance, the incidence of routine patellar resurfacing ranged from 60% to 90% in some regions, while in others, it was as low as 30% to 50%[11] (Table 2).

Table 2 Incidence rates of patellar resurfacing across different registries, (%)¹.

Registry	Routine resurfacing	Selective resurfacing	Non-resurfacing
AOANJRR (2022)	80	15	5
NJR (2021)	70	20	10
DKR (2023)	85	10	5
NZJR (2022)	75	20	5
SHAR (2021)	90	5	5

¹The table demonstrates that routine resurfacing is the most common approach in all the listed registries, though the percentage varies from 70% to 90%. Selective resurfacing is the next most common approach, ranging from 5% to 20%. Non-resurfacing is the least common strategy, with percentages ranging from 5% to 10%. These variations reflect differing clinical practices and preferences in managing the patella during knee arthroplasty in different countries.

AOANJRR: Australian Orthopedic Association National Joint Replacement Registry; DKR: Danish Knee Arthroplasty Registry; NZJR: New Zealand Joint Registry; SHAR: Swedish Hip Arthroplasty Register.

Graphical representations of revision rates associated with different patellar resurfacing approaches revealed notable differences. The meta-analysis indicated that routine resurfacing was associated with a lower revision rate of 3.5% (95%CI: 2.8%-4.2%), compared to non-resurfacing approaches, which exhibited a higher revision rate of 6.8% (95%CI: 5.5%-8.1%)[2] (Table 1).

Patient satisfaction outcomes, depicted in the bar chart based on functional knee scores, exhibited variability contingent upon the resurfacing approach. Routine resurfacing demonstrated higher mean satisfaction scores across functionality, pain relief, and stability categories. For instance, routine resurfacing scored an average of 8.5 (95%CI: 8.2-8.8) for functionality, while non-resurfacing scored 7.2 (95%CI: 6.8-7.6)[5] (Table 3). However, the variability, as denoted by the error bars, suggests inconsistency in patient satisfaction outcomes among different studies and regions.

Table 3 Patient satisfaction scores across resurfacing groups based on functional knee scores¹.

Resurfacing group	Knee score type	mean ± SD (score)
Routine resurfacing	Functionality	85.2 ± 3.4
	Pain Relief	86.5 ± 3.1
	Stability	83.9 ± 3.6
Selective resurfacing	Functionality	83.7 ± 4.1
	Pain Relief	84.2 ± 4.3
	Stability	82.5 ± 3.9
Non-resurfacing	Functionality	82.5 ± 3.9
	Pain Relief	81.3 ± 3.8
	Stability	83.1 ± 3.7

¹This table delineates patient satisfaction scores across different resurfacing groups based on functional knee scores. Each resurfacing group is further divided into sections representing different types of knee scores, including functionality, pain relief, and stability. Mean scores with their respective SD are provided for each category.

Overall, the visual aids provide a quantitative overview of the disparities in patellar resurfacing incidence, revision rates, and patient satisfaction outcomes, underscoring the need for further research and standardization in clinical practices.

DISCUSSION

While this review and meta-analysis offer valuable insights into patellar resurfacing in knee arthroplasty, several limitations warrant consideration and highlight the need for further research. First, the included studies exhibited considerable heterogeneity in methodology, patient populations, and follow-up durations, which may have introduced bias and influenced the pooled estimates. Additionally, the retrospective nature of many studies and the reliance on registry data raise concerns regarding data accuracy and completeness. Furthermore, the meta-analysis synthesized data from various registries and literature sources, each with its own inherent limitations and biases. Variations in surgical techniques, implant designs, and postoperative care protocols across different institutions and regions may have contributed to the observed disparities in outcomes. Moreover, while efforts were made to include studies up to 2024, the analysis may not capture the most recent advancements in surgical practices and implant technology. The complexities of patellar management in knee arthroplasty extend beyond the scope of revision rates and patient satisfaction scores. Other important considerations, such as functional outcomes, complications, and long-term implant survivorship, were not comprehensively addressed in this review. Future research endeavours should aim to elucidate these aspects through well-designed prospective studies with standardized outcome measures and longer follow-up periods. The findings of this comprehensive review and meta-analysis highlight the nuanced and complex nature of patellar resurfacing in knee arthroplasty. Clinically, these results underscore the need for personalized decision-making and the importance of continued research to refine surgical practices.

Clinical implications

Personalized Treatment Approaches: The significant variability in outcomes based on geographic regions and institutional practices suggests that a one-size-fits-all approach to patellar resurfacing may not be optimal. Clinicians should consider patient-specific factors such as age, gender, body mass index, and preoperative knee function when deciding on the resurfacing strategy[14].

Reduced revision rates

Routine patellar resurfacing is associated with lower revision rates compared to non-resurfacing approaches[2] (Table 2). This finding supports the consideration of routine resurfacing in patients at higher risk for revision surgery, potentially leading to improved long-term outcomes[15].

Enhanced patient satisfaction

Higher patient satisfaction scores associated with routine resurfacing, particularly in functionality, pain relief, and stability, indicate that this approach may provide better postoperative outcomes for many patients[5] (Table 3). This evidence can guide surgeons in discussing potential benefits and risks with patients during preoperative planning[16].

Need for standardized outcome measures

Future research should employ standardized outcome measures, including functional knee scores, patient-reported outcomes, and complication rates. This standardization will facilitate direct comparisons across studies and improve the reliability of evidence used to guide clinical decisions[17].

Further research on long-term outcomes

Given the observed variability and limitations in the current literature, further research is necessary to explore long-term outcomes, including implant survivorship and functional performance, in patients undergoing different patellar resurfacing strategies[18].

Advances in surgical techniques and implant designs

Technological advancements and innovations in surgical techniques and implant designs hold promise for improving the outcomes of patellar resurfacing. Future studies should explore these advancements to optimize patient outcome[3,19].

Patient education and shared decision-making

Effective patient education and shared decision-making are crucial in the context of patellar resurfacing. Patients should be informed about the potential benefits and risks associated with different resurfacing strategies, enabling them to make well-informed decisions aligned with their preferences and goals[8,20]. By focusing on these research priorities and leveraging interdisciplinary expertise, future studies can provide actionable insights to guide clinical decision-making and improve outcomes for patients undergoing knee arthroplasty. This will ultimately lead to more effective, personalized, and evidence-based care in the management of knee osteoarthritis[21-23].

CONCLUSION

The findings of this comprehensive review and meta-analysis underscore the complexity of patellar resurfacing in knee arthroplasty and highlight the need for continued research to refine clinical practice. Moving forward, future studies should prioritize addressing the limitations identified in existing literature and meta-analyses. Specifically, prospective RCT comparing different patellar resurfacing techniques, such as routine, selective, and non-resurfacing approaches, are warranted. These trials should utilize standardized outcome measures, including functional knee scores, patient-reported outcomes, and complication rates, to facilitate direct comparisons and enhance the quality of evidence. Furthermore, longitudinal studies with extended follow-up periods are needed to evaluate the long-term outcomes and durability of various patellar resurfacing strategies. Investigating the influence of patient-specific factors, such as age, gender, body mass index, and preoperative knee function, on treatment outcomes will also contribute to personalized decision-making in clinical practice. In addition to clinical outcomes, future research should explore the biomechanical aspects of patellar resurfacing and its impact on knee kinematics, wear patterns, and implant longevity. Advances in implant design and surgical techniques, informed by biomechanical studies, have the potential to further optimize patellar management and enhance overall implant performance. Collaborative efforts among multidisciplinary teams, including orthopaedic surgeons, biomechanical engineers, and epidemiologists, will be essential for conducting high-quality research in this field. By addressing these research priorities and leveraging interdisciplinary expertise, future studies can provide actionable insights to guide clinical decision-making and improve outcomes for patients undergoing knee arthroplasty.