Beta-Tricalcium Phosphate Block for Donor Site Morbidity of the Patella in Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Graft

PURPOSE: This study aimed to investigate anterior knee symptoms in patients who underwent anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) graft followed by implantation of a beta-tricalcium phosphate (β-TCP) block as a bone void filler. MATERIALS AND METHODS: We retrospectively reviewed 84 cases of synthetic bone grafting using a β-TCP block for the patellar bone defect in ACL reconstruction with a BPTB autograft. Computed tomography of the operated knee was performed immediately after the surgery to evaluate whether the grafted β-TCP block protruded forward from the anterior surface of the patella. On the basis of the results, the cases were divided into a protrusion group (n=31) and a non-protrusion group (n=53). Anterior knee symptoms at 12 months postoperatively and absorption of the grafted β-TCP block were compared between the two groups. RESULTS: Except for patellofemoral crepitus, there was no significant difference in anterior knee symptoms between the two groups (p>0.05). The incidence of patellofemoral crepitus was significantly lower in the protrusion group than in the non-protrusion group (p=0.027). The groups showed no significant difference in β-TCP absorption. CONCLUSIONS: The present study demonstrated that the protrusion of β-TCP that was used as a bone void filler had no adverse effects.