Aim: The study aimed to assess tendon length change following patello-femoral replacement (PFR) surgery and total knee replacement (TKR).
Method: A retrospective analysis was conducted of 40 patients undergoing PFR surgery and 40 patients undergoing TKR and an unoperated control group. Immediate preoperative radiographs were compared with those at 1 year postoperatively. Intra/inter-observer error was assessed in four observers.
Result: In the unoperated patients the mean shortening was 0.6% (range 6% shortening to 3% lengthening). The mean shortening after PFR surgery was 0.1% of shortening (range 14% shortening to 11% lengthening). The mean shortening after TKR was 7.14% (range 25% shortening to 7% lengthening).
Conclusion: Shortening of the patella tendon after PFR surgery occurs infrequently and less severely compared with TKR.
Level of evidence: Level 2 prognostic study.