The Effect of Infrapatellar Fat Pad Resection in Total Knee Replacement on Patella Tendon Length and Functional Outcomes after Five Years

Background : It remains unclear whether infrapatellar fat pad (IPFP) excision leads to patella tendon shortening. Shortening of the tendon alters the biomechanics of the knee and can be problematic however current literature is divided regarding the effect of IPFP resect ion on patella length and functional outcomes following total knee replacement. Methods : Our aim was to identify any functional and radiographic differences incurred with IPFP resection. We conducted a retrospective study comparing resection and preservation of the infrapatellar fat pad between 2007 - 2009 using the Stryker Triathlon or Duracon implants between two independent consultant surgeons. 168 consecutive patients were recruited. Baseline demographics were similar between resection and preservation groups with a mean age of 68.5 (70 vs 67, p=0.17), BMI 31.71 (31.02 vs 32.4, p=0.84) and pa tella resurfacing 23.5 (24 vs 23, p=0.29). Results : Comparisons between the resection and preservation groups for the Insall - Salvati, Modified Insall - Salvati, Caton - deschamps and Blackburne - peel ratios preoperatively, at one year and five years postoperat ively did not demonstrate any statistically significant differences. Knee society scores (KSS) preoperatively (45.36 vs 40.5, p=0.31) and at five years postoperatively (90.49 vs 85.31, p=0.2) were not statistically different. Similarly anterior knee pain s cores (AKPS) demonstrated no statistical significance between groups preoperatively (50.6 vs 42.8, p=0.3) and at five years post operatively (69.4 vs 62.0, p=0.88). Conclusion : There is no statistical difference in radiological measures or functional score s (AKPS &KSS) at one or five years post - operatively between resection or preservation of the infrapatellar fat pad following total knee arthroplasty for primary osteoarthritis.