A randomised, controlled trial of circumpatellar electrocautery in total knee replacement without patellar resurfacing

Abstract

The efficacy of circumpatellar electrocautery in reducing the incidence of post-operative anterior knee pain is unknown. We conducted a single-centre, outcome-assessor and patient-blinded, parallel-group, randomised, controlled trial to compare circumpatellar electrocautery with no electrocautery in total knee replacement in the absence of patellar resurfacing. Patients requiring knee replacement for primary osteoarthritis were randomly assigned circumpatellar electrocautery (intervention group) or no electrocautery (control group). The primary outcome measure was the incidence of anterior knee pain. A secondary measure was the standardised clinical and patient-reported outcomes determined by the American Knee Society scores and the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. A total of 131 knees received circumpatellar electrocautery and 131 had no electrocautery. The overall incidence of anterior knee pain at follow-up at one year was 26% (20% to 31%), with 19% (12% to 26%) in the intervention group and 32% (24% to 40%) in the control group (p = 0.02). The relative risk reduction from electrocautery was 40% (9% to 61%) and the number needed to treat was 7.7 (4.3 to 41.4). The intervention group had a better mean total WOMAC score at follow-up at one year compared with the control group (16.3 (0 to 77.7) versus 21.6 (0 to 76.7), p = 0.04). The mean post-operative American Knee Society knee scores and function scores were similar in the intervention and control groups (knee score: 92.4 (55 to 100) versus 90.4 (51 to 100), respectively (p = 0.14); function score: 86.5 (15 to 100) versus 84.5 (30 to 100), respectively (p = 0.49)). Our study suggests that in the absence of patellar resurfacing electrocautery around the margin of the patella improves the outcome of total knee replacement.

Comparison of Clinical Outcomes between Patellar Resurfacing and Nonresurfacing in Total Knee Arthroplasty: Retrospective Study of 130 Cases

“…33 These pain receptors are destroyed by electrocautery, to reduce postoperative AKP. An observational study comparing two groups of patients (n = 131 each) undergoing patellar nonresurfacing in TKA, with or without circumpatellar electrocautery, 34 found that the incidence of AKP was significantly lower in the group receiving circumpatellar electrocautery than in the other group. In two prospective studies, circumpatellar electrocautery was performed in both patellar resurfacing and patellar nonresurfacing TKA.…”

Anterior knee pain after a total knee arthroplasty: What can cause this pain?

“…The synovium, lateral retinaculum, infrapatellar fat pad, periosteum and subchondral bone of patellae affected with degenerative disease are all richly supplied with type Ⅳa FNEs and fibres containing Substance P [2] . A key aim of this study was to identify literature evaluating the different determinants of AKP after a TKA was found [2,8,9,12,13,15,18,22,23,[25][26][27]30,34,[36][37][38][39][40][41] . The articles reviewed confirm this study's hypothesis that anything that alters the patellofemoral joint (PFJ) mechanics can activate these FNEs and thus induce AKP after TKA [22] .…”

“…The recommendation of this study is that the main focus should be on determining the correct placement and maybe incorporating the ACL (if present) in TKA placement. [23] . One study found a lower prevalence of AKP due to the resection of Hoffa's fat pad [66] .…”

“…Although numerous design improvements have reduced the incidence of AKP, nevertheless approximately 5%-10% of patients still experience Anterior Knee Pain (AKP)(ranging from 0.4%-49.0%) [1][2][3][4][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . Many theories have been proposed to explain the etiology of AKP [1][2][3][4][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . In sports medicine it has been observed that some patients can have severe patellofemoral pain while their articular cartilage appears normal, and that patients with severe patellofemoral cartilage damage can be pain free [26] .…”

Patellar denervation for Anterior Knee Pain Management in Knee Arthroplasty

“…9 In our study, post-surgical knee flexion was significantly lower in patients submitted to PD (p = 0.009), which is not consistent with function results previously described. Considering that a reduction in knee range of motion can occur in patients TKA in general, 14 more research is needed to better assess this variable.…”