OBJECTIVETo explore the operating procedures and therapeutic effects of medial patellofemoral ligament reconstruction with Tightrope(Arthrex, FL, USA) button fixation at lateral femoral cortex.

METHODSFrom May 2014 to July 2016, 9 patients with traumatic patellar dislocation were treated. There were 5 males and 4 females, ranging in age from 16 to 47 years old, with an average of 23.7 years old. All the patients underment arthroscopic lateral retinaculum release and joint debridement first. Then the medial patellofemoral ligament was reconstructed by using a semitendinosus autograft. The ends of semitendinosus were pulled into two patellar tunnels respectively, knotted and fixed at the lateral side of patella. The semitendinosus loops were suspended and fixed through femoral tunnel with Tightrope button. The knee was fixed to about 60 degree and the tension of MPFL was adjusted by pulling Tightrope wire under arthroscopic observation. Two patients received superomedial transfer of tibial tuberosity on account of TT-TG >=20 mm.

RESULTSAll the patients were followed up, and the duration ranged from 6 to 23 months, with an average of 13.6 months. Patellar stability was re-obtained in all patients. No dislocation re-currenced during the follow-up period. The Kujala score(scoring of patellofemoral disorders) was improved at the latest follow-up compared with that before operation. All the patients returned to routine life.

CONCLUSIONSReconstruction of medial patellofemoral ligament with the Tightrope button fixation on the femoral side for the treatment of traumatic patellar dislocation is effective and economic. The method make the MPFL tension adjustable during the reconstuction under arthroscopy. The MPFL tension should be adjusted at 60 degree flexion of knee in order to avoid making tension level too high.