Effect of Excision of the Fat Pad in Total Knee Replacement Surgery. A Randomised Controlled Trial

Introduction:

The infrapatellar fat pad (Hoffa's fat pad) is a structure which is located intra-articularly. Its function is not well known. During knee replacement surgery, some surgeons would prefer removing the whole of the fat pad as this can improve exposure of the knee joint, as it can affect exposure of the knee joint which will in turn make the procedure slightly more efficient. Other surgeons would rather resect the minimum amount and preserve the bulk of the structure as anecdotally this is thought to decrease the level of post operative pain. This surgical step fat pad resection is a very small part of the whole total knee replacement procedure.

A previous retrospective review of patients whose fat pad had been removed showed that they were nearly twice as likely to experience postoperative pain (P = 0.0005), while another study showed that they are at a slight risk of patellar tendon shortening.

A randomised controlled trial of 68 patients did not show any difference in patella tendon length at six months and no difference in pain relief in both groups 3. However this study did not evaluate the functional outcome in both groups.

To our knowledge, there are no RCT looking at the effect of the excision or preservation of the fat pad in TKR and the functional outcomes post operatively.

Study Hypothesis:

Excision of Hoffa's fat pad during total knee replacement surgery does not affect functional outcome, pain level after surgery or the patella tendon length at either one or two years.