Infrapatellar Fat Pad Preservation versus Resection in Total Knee Arthroplasty

Preservation of normal-quality infrapatellar fat pads (IPFP) during total knee arthroplasty (TKA) has been proposed, and IPFP of abnormal quality are recommended for resection.

In this trial, patients with knee osteoarthritis (OA) undergoing TKA were stratified by IPFP status on magnetic resonance imaging (Group 1 with normal IPFP [signal intensity score ≤1; ranging from 0 to 3]; Group 2 with abnormal IPFP [signal intensity score ≥2]) and randomly assigned in a 1:1 ratio to IPFP preservation or IPFP resection. The primary outcome was 12-month change in the mean of five Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales (KOOS₅), which range from 0 (worst) to 100 (best).

In Group 1, 179 participants were randomly allocated to IPFP preservation (n=90) and IPFP resection (n=89), and 198 participants were randomly assigned to IPFP preservation (n=101) and IPFP resection (n=97) in Group 2. The increases in KOOS₅ score were 38.1 and 36.1 in Group 1 and were 39.2 and 37.5 in Group 2 in IPFP preservation and IPFP resection groups, respectively, resulting in between-group differences of 1.9 (95% confidence interval [CI], -1.7 to 5.6) in Group 1 and 1.6 (95% CI, -1.3 to 4.6) in Group 2. Adverse events were predominantly nonserious musculoskeletal or skin-related events (three vs. two in Group 1 and eight vs. two in Group 2).

Resection of abnormal IPFP and preservation of normal IPFP did not improve postoperative outcomes 12 months after TKA. (Funded by National Key Research & Development Program of China, Clinical Research Startup Program of Southern Medical University, and National Natural Science Foundation of China; ClinicalTrials.gov number, NCT03763448.).