To investigate the effect of preserving the infrapatellar fat pad (IPFP) on prognosis after primary total knee arthroplasty (TKA).

A retrospective analysis was performed with data from 237 patients (283 knees) who had undergone primary TKA at the Fuyang No.2 People’s Hospital, between 2015 and 2017. There were 124 knees (109 patients) in the IPFP preservation group (preservation group) and 159 knees (128 patients) in the IPFP resection group (resection group). The intraoperative blood loss, 24h postoperative drainage, operation time, visual analogue scale (VAS), American Knee Society (AKS) scores, postoperative joint function, wound complications after 72 hours and the incidence of precondylar pain after two years of follow-up were observed. The measurement data used t test for comparison and the counting data were compared by chi-square test.

There was no difference in the intraoperative hemorrhage volume, the postoperative wound drainage volume within 48h, VAS within 72 h, AKS score, joint function, and incidence of anterior knee pain between the two groups. In the preservation group, two patients (1.6%) had wound complications (over three days of continuous bleeding), while 13 patients (8.2%) occured wound complications in the resection group. The probabilities of wound complications in the two groups were statistically significant (χ²=5.544, P<0.05). Unilateral and bilateral knee arthroplasty surgery time was (84±15) min and (144±13) min in preservation group, and (74±13) min and (133±15) min in resection group, respectively. The operation time was longer in the preservation group than in the resection group (unilateral: t=5.746, P<0.05, bilateral: t=6.463, P<0.05).

The method of preservation the IPFP, which involves complete IPFP preservation without affecting the surgical procedure may increase the operation time and could not alleviate postoperative pain in the short term, but it can reduce the probability of wound complications.