Patellafraktur nach MPFL-Plastik bei erhöhtem TTTG-Abstand

A 19-year-old patient suffered recurrent patellar dislocations and was treated by medial patellofemoral ligament (MPFL) reconstruction with a gracilis ligament autograft. Normal knee flexion while bowling led to a patella fracture 4 years after surgery. Further diagnostics showed a normal mechanical axis, no torsional deformity, no patellar or trochlear dysplasia and normal patella height. Source of the patellar instability was an increased tibial tuberosity-trochlea groove distance (19 mm). Surgical treatment was carried out with screw fixation of the patella fracture and tibial tuberosity transfer. The source of the patellar instability was not completely analyzed before surgery and ultimately led to a patellar fracture. A complete diagnostics of a patellar dislocation is always necessary before surgery.