Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

Does Patellar Denervation with Electrocautery Benefits for Total Knee Arthroplasty without Patellar Resurfacing: A Meta-analysis of Randomized Controlled Trails

To investigate the effects of patellar denervation (PD) and non-patellar denervation (NPD) after primary total knee arthroplasty (TKA) without patellar resurfacing, this study conducted systematic electronic searches in November 2023 using PubMed, Embase, Web of Science, Cochrane, and Scopus, adhering to Cochrane Collaboration recommendations. Only randomized controlled trials (RCTs) were included. Additionally, a manual search was performed to identify potentially eligible studies from the reference lists of review articles. Two researchers independently conducted literature reviews, data extraction, and risk of bias assessments. The outcome analysis encompassed the incidence of anterior knee pain (AKP), visual analogue scale (VAS), range of motion (ROM), American Knee Society Score (KSS), Oxford Knee Score (OKS), patellar score (PS), complications, and reoperations. Meta-analysis was executed using RevMan 5.3 software. To enhance the credibility of the study, TSA v0.9 software was utilized to perform power analysis on the overall efficacy of primary and secondary outcomes. Twelve studies involving 1745 patients (1587 knees) were included, with 852 undergoing PD and 893 undergoing NPD. Results indicated a superior reduction in AKP incidence in the PD group compared to the NPD group. Statistically significant differences were observed between PD and NPD in KSS, OKS, and PS. However, the upper limit of the 95% confidence interval for each outcome fell below the minimal clinically important difference (MCID). No significant differences were found in VAS and ROM between PD and NPD. Additionally, PD was not associated with an increased incidence of complications or reoperations. Within 12 months and beyond, PD was proven to be a beneficial intervention in reducing AKP following TKA without patellar resurfacing, achieved without an increase in complications or reoperations. Regarding KSS, OKS, and PS, the minimal advantage achievable through PD may not be clinically significant.

Bilateral simultaneous total knee arthroplasty with and without patellar resurfacing. A prospective single surgeon series with a minimum follow-up of 7 years

BACKGROUND

Total knee arthroplasty (TKA) is the most effective treatment for end-stage adult knee osteoarthritis, but it has been reported that patient satisfaction may vary. A malfunction of the patellofemoral joint may produce anterior knee pain (AKP) for several reasons. While some surgeons systematically resurface the patella despite the risk of potential complications such as fracture, loosening, or wear of the patella, others prefer to preserve it to reduce AKP and revision rates. This study aimed to evaluate whether patellar resurfacing had better clinical and functional outcomes, complications, and revision rates in patients undergoing simultaneous bilateral total knee arthroplasty.

METHODS

We conducted a prospective cohort study, including patients who underwent bilateral simultaneous TKA in which the patella was replaced in one knee and preserved in the other, with a minimum follow-up of 7 years. We assessed clinical and functional outcomes with the Knee Society Score (KSS) and Visual Analogue Scale (VAS); complications and revision rates were also registered.

RESULTS

The final series consisted of 43 patients with 86 knee arthroplasties. After a mean of 7.6 years of follow-up, no significant differences were found regarding KSS (clinical: 82.8 ± 7.4 versus 83.2 ± 3.4, p = 0.92; functional 89.1 ± 8.2: versus 90.4 ± 6.8; p = 0.99), VAS (2.0 ± 0.9 versus 1.8 ± 1.0; p = 0.84), complications (10.5% versus 8.1%; p = 0.57), or revision rates (2.3% versus 2.3%; p = 0.99) when comparing patellar resurfacing versus retention.

CONCLUSION

In the context of total knee arthroplasty, patellar replacement did not demonstrate statistically significant differences concerning patellar retention in clinical nor functional outcomes, AKP, complications, or revision rates after a minimum of 7 years of follow-up.

What are the Outcomes of Secondary Patella Resurfacing for Dissatisfaction Following Primary Knee Arthroplasty? A Systematic Review and Meta-Analysis of 604 Knees

BACKGROUND

Secondary patella resurfacing is often performed for dissatisfaction following primary knee arthroplasty where the native patella was retained. The purpose of this meta-analysis was to evaluate outcomes of secondary patella resurfacing.

METHODS

The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting on patients who underwent secondary patella resurfacing after previous primary knee arthroplasty with retention of the native patella were considered eligible. The risk of bias was assessed using the Methodological Index for Non-Randomized studies tool. A random-effects model and the inverse-variance weighting method was used for meta-analysis. There were sixteen retrospective studies including 604 knees (594 patients) with a mean follow up of 42 months (range, 2 to 197).

RESULTS

An overall improvement in patient-reported outcomes (PROMs) was achieved in 53% of cases from pooled data available for 293 knees [95% Confidence Interval (CI) (0.44, 0.62), I2=68% - moderate heterogeneity]. The pooled proportion of patients satisfied with the procedure was 59% [95% CI (48, 68), I2 = 70% - moderate heterogeneity] in a sample size of 415. There was a minimal rate (2%) of complication incidence when performing secondary patella resurfacing and a pooled rate of revision surgery of 10%.

CONCLUSIONS

An improvement in pain, satisfaction, and PROMs was achieved in slightly more than half of the patients following secondary patella resurfacing. However, studies lacked standardized objective selection criteria for the procedure and the available data was predominantly retrospective, with high heterogeneity and variation in outcome reporting.

Anterior knee pain and sit-up tests predicts patients' satisfaction and improvement in quality of life after anterior stabilized total knee replacement without patellar resurfacing

PURPOSE

The purpose of this study was to assess patient satisfaction and identify risk factors for dissatisfaction after anterior stabilised conventional total knee arthroplasty (TKA) without patellar resurfacing, using the Goodman score.

METHODS

We conducted a cross-sectional study using data from our institutional database from 1 January 2018 to 1 March 2021. Patients who underwent TKA with the Vanguard® Cruciate Retaining Anterior Stabilized Knee System (Zimmer Biomet, Warsaw, Indiana, USA) without patellar replacement were included. Patients with other bearing surfaces (posterior stabilised or medial congruent) or diagnosed with infection or instability were excluded. Patients' reported outcomes, body mass index (BMI), passive range of motion, the timed up-and-go test, sit-up test, and algometry were assessed. Patients were also asked if they had anterior knee pain. Satisfaction was assessed using the Goodman scale, and logistic multivariate regression was used to identify variables associated with dissatisfaction and perceived improvement in quality of life.

RESULTS

A total of 131 TKA patients were included in the study. The median satisfaction score was 100 (interquartile range [IQR], 87.5 to 100), with the 75-point threshold at the 90th percentile according to Section A of Goodman. Section B of Goodman showed that 113 TKA patients (86.26%) reported "great improvement" or "more than I ever dreamed." Multivariate logistic regression revealed that anterior knee pain (OR 5.16, 95% CI 1.24 to 21.39), the sit-up test (OR 0.63, 95% CI 0.49 to 0.81), and BMI (OR 0.84, 95% CI 0.70 to 0.99) were significantly associated with patient dissatisfaction and a worse perceived improvement in quality of life. The receiver operating characteristics curve for the models had areas under the curve of 0.83 (95% CI 0.69 to 0.97) and 0.82 (95% CI 0.70 to 0.94), respectively.

CONCLUSION

Anterior stabilised TKA without patellar resurfacing can achieve 90% satisfaction and 86% improvement in quality of life. To improve these results, it is essential to prevent and treat anterior knee pain and enhance quadriceps strength.

LEVEL OF EVIDENCE

Level III (retrospective cohort study).

Patellar resurfacing versus retention in cruciate-retaining and posterior-stabilized total knee arthroplasty

Aims

This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates.

Methods

A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed.

Results

There were 4,135 TKAs (2,068 resurfaced and 2,027 unresurfaced) identified in 35 separate cohorts from 33 peer-reviewed studies. Anterior knee pain rates were significantly higher in unresurfaced knees overall (odds ratio (OR) 1.84; 95% confidence interval (CI) 1.20 to 2.83; p = 0.006) but more specifically associated with CR implants (OR 1.95; 95% CI 1.0 to 3.52; p = 0.030). There was a significantly better Knee Society function score (mean difference (MD) -1.98; 95% CI -1.1 to -2.84; p < 0.001) and Oxford Knee Score (MD -2.24; 95% CI -0.07 to -4.41; p = 0.040) for PS implants when patellar resurfacing was performed, but these differences did not exceed the minimal clinically important difference for these scores. There were no significant differences in complication rates or infection rates according to implant design. There was an overall significantly higher reoperation rate for unresurfaced TKA (OR 1.46 (95% CI 1.04 to 2.06); p = 0.030) but there was no difference between PS or CR TKA.

Conclusion

Patellar resurfacing, when performed with CR implants, resulted in lower rates of anterior knee pain and, when used with a PS implant, yielded better knee-specific functional outcomes. Patellar resurfacing was associated with a lower risk of reoperation overall, but implant type did not influence this.

Patellar resurfacing was not associated with a clinically significant advantage when a modern patellar friendly total knee arthroplasty is employed: A systematic review and meta-analysis

BACKGROUND

Modern total knee arthroplasty (TKA) femoral components are designed to provide a more optimal articular surface for the patella whether or not it has been resurfaced. Previous systematic reviews comparing outcomes of patellar resurfacing and no resurfacing combine both historic and modern designs.

AIMS

The aim of this study was to investigate the effect of patellar resurfacing in modern "patellar friendly" implants on (1) incidence of anterior knee pain, (2) patient reported outcomes (3) complication rates, and (4) reoperation rates compared with unresurfaced patellae in primary TKA.

METHODS

MEDline, PubMed and google scholar studies were evaluated using SIGN assessment tool and data analysis was conducted using Review Manager 5.2 on only randomised controlled trials. The search terms were: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, patellar retaining.

RESULTS

Thirty-two randomised controlled studies were identified that reported the type of TKA implant used: 11 used modern "patellar friendly" implants; and 21 older "patellar non-friendly" implants. Among "patellar friendly" TKAs there were no significant differences in anterior knee pain rates between resurfaced and unresurfaced groups. Patellar resurfacing with "patellar friendly" implants had significantly higher clinical (mean difference (MD) -0.77, p = 0.007) and functional (MD -1.87, p < 0.0001) knee society scores (KSS) than unresurfaced counterparts but these did not exceed the minimal clinically important difference (MCID). Resurfacing with "patellar friendly" implants was not associated with a significant (p = 0.59) difference in the Oxford knee score (OKS), in contrast when a "patellar non-friendly" implant was used there was a significant difference (MD 3.3, p = 0.005) in favour of resurfacing. There was an increased risk of reoperation for unresurfaced TKAs with "non-patellar friendly" implants (Odds ratio (OR) 1.68, 95% CI 1.03-2.74, p = 0.04), but not for unresurfaced patellae with "patellar friendly" implants (OR 1.17, CI 0.59-2.30).

CONCLUSIONS

Patellar resurfacing in combination with a modern patellar friendly implant was not associated with a lower rate of anterior knee pain, complications, or reoperations compared to not resurfacing, nor did it give a clinically significant improvement in knee specific function. In contrast patellar resurfacing in combination with a "non-friendly" TKA implant was associated with a significantly better OKS and lower reoperation rate. Implant design should be acknowledged when patellar resurfacing is being considered.

What can we expect from patellar denervation in knee arthroplasty? An updated systematic review and meta-analysis

Denervation by electrocauterization was proposed to be efficient in preventing anterior knee pain (AKP) following arthroplasty. The purpose of this study was to evaluate the effects of patellar denervation (PD) in primary knee arthroplasty. Systematic search was performed in PubMed, ScienceDirect, Cochrane Library, and ClinicalKey databases until July 2022 for published articles. The quantitative analyses were carried out by Review Manager 5.4 software. Twenty-one studies were included. Overall incidence of AKP, visual analog scale (VAS), and knee society score were significantly superior in PD group. Denervation also showed better outcomes in incidence of AKP at each follow-up time point, and in VAS and range of motion (ROM) at ≤3 months. Subanalyses based on depth of electrocautery showed statistically better results with 2–3 mm depth in VAS and PS compared to ≤1 mm. This study concluded that PD might contribute to lower incidence of knee pain. Patients who expect quicker recovery in pain and ROM may benefit from this procedure.

[Long-term effectiveness of different patellar treatments in primary total knee arthroplasty]

Objective

To compare the long-term effectiveness of patellar denervation by electrotomy combined with patellar replacement and patellar denervation by electrotomy alone in primary total knee arthroplasty (TKA).

Methods

A retrospective analysis was conducted on the clinical data of 30 patients treated with primary TKA of both knees between July 2013 and March 2015 who met the selection criteria. There were 11 males and 19 females, aged 56-79 years, with an average age of 67.6 years. One knee was randomly selected for patellar denervation by electrotomy combined with patellar replacement during TKA (combined group), while the other knee was treated with patellar denervation by electrotomy alone (control group). All patients adopted the same type of total knee prosthesis. After surgery, the patients were followed up regularly, and the occurrence of complications was recorded. The functions of the knee and patella were evaluated using the Knee Society Score (KSS) and Feller score, respectively. The position of the prosthesis, patella trajectory, and prosthesis loosening and wear were observed by imaging examination.

Results

All 30 patients were followed up 81.4-103.5 months, with an average of 90.4 months. The patellar thickness of the combined group ranged from 21 to 26 mm, with an average of 23.0 mm. The position of the prosthesis and patella trajectory in the combined group and the control group were good, without obvious loosening or wear. After operation, 2 sides (6.7%) in the combined group and 3 sides (10.0%) in the control group presented joint adhesion and poor activities. No complication such as lower limb deep vein thrombosis, aseptic fractures, and infections around the prosthesis occurred in both groups. At last follow-up, the KSS clinical score, KSS function score, and Feller score showed no significant difference between the two groups ( P>0.05). According to the KSS score, 24 patients (80.0%) had no obvious preference for patellar denervation combined with patellar replacement, 3 patients (10.0%) preferred patellar replacement combined with patellar denervation, and 3 patients (10.0%) preferred no patellar replacement. Anterior knee pain occurred in 6 sides (20.0%) of both groups.

Conclusion

There is no significant difference in the long-term effectiveness between patellar denervation combined with patellar replacement and patellar denervation alone conducted in patients with knee osteoarthritis undergoing primary TKA.