Detachment and Intra-Articular Migration of a Bone Patella Tendon Bone Graft in ACL Reconstruction

The frequency of anterior cruciate ligament (ACL) reconstruction performed worldwide has been significantly increasing per year. Despite the common nature of the procedure, controversy remains regarding the natural history of ACL injuries, surgical technique, graft choice, and long-term outcomes. We present a case report of a 33-year-old male who had a history of an ACL reconstruction that was performed 12 years ago using bone patella tendon bone (BPTB) graft, by using a press-fit femoral technique. He was referred to our outpatient department due to a re-rupture of his ACL following a football injury. Radiographs of the knee joint that were taken revealed a rectangular prominence of bone projected over the femoral notch extending intra-articularly. The patient also had a magnetic resonance imaging (MRI) scan, which revealed a rerupture of the previously reconstructed ACL and evidence of an intra-articular bony prominence. The patient had arthroscopic revision of his ACL reconstruction by using Semitendinosus allograft, which confirmed the complete tear of previously reconstructed ACL graft. Moreover, a bony prominence was well demonstrated intra-articularly close to the femoral intercondylar notch. We hypothesized that this was a part of the BPTB graft that was reconstructed 12 years ago and had either migrated inside the joint or was never positioned appropriately (not adequately fitted in the femoral tunnel). The bony prominence was shaved by using an arthroscopic bony burr, the ACL was revised, and the patient had a good recovery. Intra-articular migration of the femoral bony ends of the BPTB is a rare complication following ACL reconstruction. The patient may be asymptomatic; however, evidence of the bony prominence is usually revealed on postoperative X-rays and magnetic resonance imaging scans.