Fat pad excision in total knee arthroplasty does not affect functional outcome or anterior knee pain at 1 year follow-up

Abstract

BackgroundIn total knee arthroplasty (TKA), excision of infra patellar fat pad (IPFP) is usually done to enhance exposure. But effects of this are not clearly understood. A few studies indicate that it may lead to increased incidence of anterior knee pain (AKP). This study was undertaken to determine the effect of excision of IPFP on incidence of AKP (as indicated by Hospital for Special Surgery (HSS) patella score), Knee society score (KSS) and functional score, change in Patellar Tendon length (as measured by Insall-Salvati ratio (ISR)) and, Range of motion (ROM). Methods135 patients (151 knees) operated by two senior arthroplasty surgeons in the period of January 2014 to December 2015 were followed-up for minimum of 1year. Group 1 consisted of 106 knees in which complete excision of fat pad was done and group 2 consisted of 45 knees in which fat pad was retained. ResultsThere was no significant difference in HSS patella score of two groups during the follow-up of 1 year. KSS and functional score was significantly better for IPFP retention group at 6 week follow-up, but in later follow-ups till 1 year, the difference was not significant. The mean change in patellar tendon length for patients with the fat pad removed (ISR=−0.022) and those with it retained (−0.011) was significantly different (p=0.026). Average range of flexion in both the groups at 1 year follow-up was beyond 110 degrees. There was a significant difference in range of flexion at 1 year of follow-up (117.07 degrees in group 1 versus 118.44 degrees in group 2, p=0.04). There were no fracture or avascular necrosis of patella in either group. ConclusionAKP and functional outcome is not significantly affected by excision of IPFP. Fat pad can be sacrificed if exposure is compromised.