Patella tendon length after patella arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomechanical Analysis
• Radiographic Assessment

Background:

• Patellofemoral replacement (PFR) and total knee replacement (TKR) are common surgical interventions for knee conditions.
• Understanding postoperative tendon length changes is crucial for assessing surgical outcomes and biomechanical function.

Purpose of the Study:

• To compare patellar tendon length changes after patellofemoral replacement (PFR) surgery versus total knee replacement (TKR).
• To evaluate the incidence and severity of tendon shortening following these procedures.

Main Methods:

• Retrospective analysis of 40 patients undergoing PFR and 40 patients undergoing TKR.
• Comparison of immediate preoperative and 1-year postoperative radiographs.
• Inclusion of an unoperated control group for baseline comparison.
• Assessment of intra/inter-observer variability in radiographic measurements.

Main Results:

• Unoperated controls showed a mean shortening of 0.6% (range: 6% shortening to 3% lengthening).
• Patellofemoral replacement (PFR) resulted in minimal mean shortening of 0.1% (range: 14% shortening to 11% lengthening).
• Total knee replacement (TKR) demonstrated significant mean shortening of 7.14% (range: 25% shortening to 7% lengthening).

Conclusions:

• Patellar tendon shortening occurs infrequently and to a lesser degree after PFR surgery compared to TKR.
• TKR is associated with a higher incidence and greater severity of patellar tendon shortening.