Resection of pathologically altered infrapatellar fat pads during total knee arthroplasty has a positive impact on postoperative knee function

Abstract

Background

The ongoing debate regarding the excision of the infrapatellar fat pad (IPFP) during total knee arthroplasty (TKA) remains a contentious issue, with established parameters for IPFP management still lacking. Excessive resection of IPFP tissue may lead to patellar tendon (PT) shortening and reduced mobility of the knee joint. This study aims to evaluate whether the resection of pathologically altered IPFP tissue during TKA affects knee joint function and PT dimensions.

Methods

A total of 100 patients with end-stage knee osteoarthritis (KOA) who successfully underwent their first TKA were randomly assigned to two groups: one group received resection of the pathologically altered IPFP tissue, while the other group underwent complete resection of all IPFP tissue. The excised IPFP specimens were subjected to pathological and immunohistochemical analysis. Patients underwent X-ray and MRI assessments prior to surgery, as well as at 6 weeks and 6 months postoperatively; additionally, the Numeric Rating Scale (NRS), Knee Injury and Osteoarthritis Outcome Scale (KOOS), and Oxford Knee Score (OKS) were utilized for evaluation. Furthermore, patellar tendon length and thickness were assessed.

Results

Histological examination of the IPFP tissue from patients with KOA revealed that not all IPFP specimens exhibited lesions under hematoxylin and eosin (HE) staining and immunohistochemical analysis, with lesion areas predominantly localized near the synovium. There was no significant difference in the NRS scores between the two patient groups at 6 weeks or 6 months postoperatively (Mann–Whitney test, P = 0.391; P = 0.055). However, a significant difference was observed in both KOOS and OKS between the two groups at 6 months after surgery (Mann–Whitney test, P < 0.05). Sonographic evaluation of patellar tendon parameters indicated a significant difference in PT thickness between the two groups only at 6 weeks postoperatively (Mann–Whitney test, P < 0.05).

Conclusions

This study demonstrated that the resection of pathologically altered IPFP tissue during TKA in patients with end-stage KOA can significantly enhance early postoperative knee joint mobility, improve life satisfaction, and mitigate the impact on PT structure.