The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study.

Abstract The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) recon- struction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with ham- strings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients under- going ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The pa- tients were randomly assigned to enter the control group (group A, standard post-operative rehabilita- tion) and the study group (group B, brace free accel- erated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method A.Vadala` R.IorioA.DeCarliV.D.Sanzo F. Conteduca A. Ferretti (&) Orthopaedic Unit and ‘‘Kirk Kilgour’’ Sports Injury Centre, S. Andrea Hospital, University of Rome ‘‘La Sapienza’’, Via Grottarossa 1065, Rome, Italy e-mail: aferretti51@virgilio.it G. Argento Radiology Unit, S. Andrea Hospital, University of Rome ‘‘La Sapienza’’, Rome, Italy [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9–11). Statistical analysis was performed using paired t- test. The mean femoral tunnel diameter increased significantly from 9.04 ± 0.05 (post-operative) to 9.30 ± 0.8 mm (follow-up) in group A and from 9.04 ± 0.03 to 9.94 ± 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 ± 0.04 to 10.01 ± 0.80 mm in group A and from 9.04 ± 0.03 to 10.60 ± 0.78 mm in group B. The in- crease in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control group. Our results suggest that bone tunnel enlargement after ACL reconstruction using hamstrings autograft can be increased by an acceler- ated, brace free, rehabilitation protocol.