In rheumatoid arthritis patients undergoing total knee replacement, resection or retention of the subpatellar fat pad have advantages of alleviating postoperative pain and improving functional recovery. However, retention of the intrapatellar fat pad is valuable for the restoration of patellar height.

A study was performed to explore the influence of resection or retention of the subpatellar fat pad on the height of the patella during total knee replacement in patients suffering from rheumatoid arthritis.

The study recruited 48 rheumatoid arthritis patients who underwent total knee replacement from Oct 2013 to Oct 2017. Participants were retrospectively assessed and allocated into resection (n=23, subpatellar fat pad were resected during operation) and retention (n=25, subpatellar fat pad were retented during operation) subpatellar fat pad group.

The postoperative complications were compared between both the cohorts. To determine the degree of pain relief and clinical effect of the knee joint, visual analogue scale (VAS) and Hospital for Special Surgery (HSS) at one year after operation was utilized. To compare alteration in postoperative patella height at one year after the operation, the Insall-Salvati ratio (I-S ratio) was utilized.

The postsurgery wound properly healed without any infection complications, prosthetic loosening, or revision. Compared to the preoperative VAS score, the postoperative VAS score at one year was found to be lower between the two groups. However, no statistical difference was witnessed between the two groups at one year after the surgery.

The postoperative HSS score between the two interventions was found to be elevated compared to before the operation. However, no difference in the HSS score was noted between the two interventions at one year after surgery. I-S ratio of resection group was found to be statistically significantly lower compared to the retention group, as shown below:

Resection or retention of the subpatellar fat pad effectively relieves post-surgery pain and improves functional recovery in rheumatoid arthritis patients. But, retention of intrapatellar fat pad is more advantageous for restoring patellar height.