Should the patella be everted during primary total knee arthroplasty? A systematic review of overlapping meta-analyses

Does intraoperative patellar eversion affect clinical and functional outcomes in patients undergoing primary total knee arthroplasty? An evidence-based meta-analysis

PURPOSE

This meta-analysis aims to compare the early postoperative recovery, complications encountered, length of hospital stay, and initial functional scores between patellar eversion and non-eversion manoeuvres in patients undergoing during primary total knee arthroplasty (TKA) based on clinical studies available in the literature.

METHODS

A systematic literature search was conducted using PubMed, Embase, Web of Science, and the Cochrane Library databases between January 1, 2000 and August 12, 2022. Prospective trials comparing clinical, radiological, and functional outcomes in patients undergoing TKA with and without patellar eversion manoeuvre were included. The meta-analysis was performed using Rev-Man version 5.41 (Cochrane Collaboration). Pooled-odds ratios (for categorical data) and mean differences with 95% confidence intervals (for continuous data) were calculated (p < 0.05 was regarded as statistically significant).

RESULTS

Ten (out of the 298 publications identified in this subject) were included for the meta-analysis. The patellar eversion group (PEG) had a significantly shorter tourniquet time [mean difference (MD) - 8.91 min; p = 0.002], although the overall intraoperative blood loss was higher (IOBL; MD 93.02 ml; p = 0.0003). The patellar retraction group (PRG), on the other hand, revealed statistically better early clinical outcomes in terms of shorter time necessary to perform active straight leg raising (MD 0.66, p = 0.0001), shorter time to achieve 90° knee-flexion (MD 0.29, p = 0.03), higher degree of knee flexion achieved at 90 days (MD - 1.90, p = 0.03), and reduced length of hospital stay (MD 0.65, p = 0.03). There was no statistically significant difference in the early complication rates, 36-item short-form health survey (1 year), visual analogue scores (1 year), and Insall-Salvati index at follow-up between the groups.

CONCLUSION

The implications from the evaluated studies suggest that in comparison with patellar eversion, patellar retraction manoeuvre during surgery provides significantly faster recovery of quadriceps function, earlier attainment of functional knee range of motion (ROM), and shorter length of hospital stay in patients undergoing TKA.

The Postoperative Effects of Patellar Eversion in Total Knee Arthroplasty: An Updated Systematic Review and Meta-Analysis

Background

During total knee arthroplasty (TKA), surgeons mobilize the patella to facilitate clear visualization of the articular surfaces and allow better prosthesis placement. According to the manipulation, this manipulation can be divided into patellar eversion and noneversion. However, the effect of patellar eversion in TKA is controversial, with substantial variability in clinical practice. This systematic review is aimed at assessing the adverse effects of patellar eversion and patellar noneversion duration in TKA.

Methods

This updated systematic literature review identified randomized controlled trials comparing patellar eversion and noneversion durations in TKA. Two investigators independently extracted data and evaluated the quality of the studies. A meta-analysis was performed using RevMan version 5.3.

Results

Nine studies with a total of 608 patients (730 knees) were included. Of these, 374 knees were classified in the eversion group and 356 knees in the noneversion group. The quality of the studies was high. The results showed that patellar eversion could increase the postoperative complication rate (relative risk [RR] = 1.67; 95% confidence interval [CI], 1.09-2.54; P = 0.02) and postoperative pain before discharge (mean deviation [MD] = 0.19; 95% CI, 0.04-0.34; P = 0.01), compared to noneversion. Additionally, patellar eversion could prolong the time until the patient is able to raise the leg while straightened (MD = 0.42; 95% CI, 0.24-0.59; P < 0.00001) and increase the length of stay (MD = 0.65; 95% CI, 0.05-1.25; P = 0.03). However, patellar eversion did not influence postoperative pain at 1 year (MD = 0.02; 95% CI, -0.23-0.28; P = 0.85), operative time (MD = -2.66; 95% CI, -8.84-3.52; P = 0.40), recovery of quadriceps force throughout the follow-up period, and Insall-Salvati ratio (MD = -0.04; 95% CI, [-0.11-0.02]; P = 0.23).

Conclusions

The patellar eversion could increase the postoperative complication rate and postoperative pain. Current evidence supports the avoidance of patellar eversion in TKA. Further large-sample and long-term trials are required to validate these results.

Patellar retraction versus eversion on functional outcomes in total knee replacement: a randomized controlled study protocol

Background

Patellar mobilization technique during total knee replacement (TKR) has been debated, with some suggesting that lateral retraction, rather than eversion, of the patella may be beneficial. This randomized controlled trial was to investigate the effects of patellar eversion on functional outcomes in TKR.

Methods and analysis

This single-center, prospective, randomized controlled test will be conducted in Jingjiang People's Hospital. Primary end-stage osteoarthritis patients that prepared for unilateral TKR were randomized to one of two patellar exposure techniques during the primary total knee arthroplasty: lateral retraction or eversion. The informed consent will be acquired in each patient. The primary outcome was operation time, length of hospital stay, and straight leg raising time. Second outcomes including Insall-Salvati ratio; range of motion at 1 month, 3 months, and 1 year following TKR; visual analog scale (VAS) at 1 month, 3 months; and Knee Society Score (KSS) score at 1 year following TKR. The significance level was defaulted as P < .05.

Results

Results will be published in relevant peer-reviewed journals.

Conclusion

Our study aims to systematically assess the functional outcomes of patellar eversion for TKR patients, which will provide clinical guidance for TKR patients.

Optimal Handling of the Patella in Tourniquet-Free Total Knee Arthroplasty: Eversion or Lateral Retraction?

Objective

To explore the optimal handling of the patella during total knee arthroplasty (TKA) without the intraoperative application of a tourniquet.

Methods

A total of 104 patients undergoing primary unilateral TKA without the intraoperative use of tourniquets from December 2018 to March 2019 in our center were included in this prospective randomized double‐blinded study, including 42 men and 62 women with a mean age of 66.3 ± 7.8 years and a minimum follow‐up of 1 year. Patients were randomly divided into an eversion group (n = 52) and a retraction group (n = 52) based on the intraoperative handling of the patella (eversion or lateral retraction). Primary outcome measures, including the visual analog scale at rest (rVAS) and the visual analog scale in motion (mVAS) for both anterior knee pain and thigh pain, opioid consumption, active range of motion (aROM), passive range of motion (pROM), the time needed for return of the straight‐leg raise (SLR), and 90° knee flexion, were recorded by an independent observer, who also noted secondary outcome measures, including operation time, length of stay (LOS), patella‐related (patellar tilt and baja) and other complications, knee swelling, Hospital for Special Surgery (HSS) scores, and the 12‐item Short Form Health Survey (SF‐12) scores.

Results

There were no significant differences between the two groups in terms of baseline parameters. At 24, 48, and 72 h postoperatively (PO), patients in the eversion group experienced more severe thigh pain than those in the retraction group (24 h: 2.6 ± 0.8 vs 2.2 ± 0.5 [P = 0.003]; 48 h: 2.0 ± 0.5 vs 1.8 ± 0.4 [P = 0.026]; 72 h: 1.1 ± 0.4 vs 0.9 ± 0.5 [P = 0.012], respectively) and consumed more opioids (24 h: 22.3 ± 7.7 vs 15.1 ± 8.9 mg [P < 0.001]; 48 h: 27.3 ± 9.3 vs 21.4 ± 10.5 mg [P = 0.003]; 72 h: 23.1 ± 8.2 vs 19.8 ± 7.6 mg [P = 0.036], respectively), but no significant difference was found in anterior knee pain (both rVAS and mVAS) preoperatively or at 24, 48 or 72 h, 3 weeks, 2 or 6 months, or 1 year PO (P > 0.05). Throughout the 1‐year follow‐up, patients in the retraction group showed significantly better function, including greater aROM and pROM at all time points (P < 0.05) and a shorter period of time needed for return to SLR (1.9 ± 0.7 vs 2.2 ± 0.8 days [P = 0.044]) and 90° knee flexion (1.2 ± 0.7 vs 1.9 ± 0.8 days [P < 0.001]). In addition, no between‐group difference was found in operation time, complication rate, swelling of the knee, or SF‐12 score during the follow‐up period (P > 0.05). The eversion group had a significantly longer LOS (5.61 ± 1.92 vs 4.93 ± 1.45 days [P = 0.044]) and worse HSS score within 2 months PO (3 weeks PO: 77.4 ± 7.6 vs 81.7 ± 7.2 [P = 0.004]; 2 months PO: 85.1 ± 7.2 vs 88.5 ± 6.1 [P = 0.011]), but at the third follow‐up (6 months PO), the HSS score in the two groups became comparable (P > 0.05). No patellar tilt occurred in either group and there was only one case of patellar baja in the eversion group, with no significant between‐group difference (P > 0.05).

Conclusion

We recommend lateral retraction rather than eversion for optimal handling of the patella during TKA because the postoperative functional recovery is better and thigh pain is relatively less severe.