Eversion and First Ray Plantarflexion Muscle Strength in Anterior Cruciate Ligament Reconstruction Using a Peroneus Longus Tendon Graft

BACKGROUND: The peroneus longus tendon has been used as a graft in orthopaedic reconstruction surgery because of its comparable biomechanical strength with the native anterior cruciate ligament (ACL) and hamstring tendon. However, one of the considerations in choosing an autograft is donor site morbidity. PURPOSE/HYPOTHESIS: This study aimed to compare ankle eversion and first ray plantarflexion strength between the donor site and its contralateral site after ACL reconstruction. The study hypothesis was that strength measurements will be different between the harvest site and contralateral healthy site. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent ACL reconstruction using a peroneus longus tendon autograft between March 2017 and December 2018 were included in this study. Patients followed a rehabilitation protocol from the first day after surgery. Ankle eversion and first ray plantarflexion strength were measured using a modified dynamometer 6 months after surgery. Donor site morbidity was assessed 6 months after surgery using the Foot & Ankle Disability Index (FADI) and American Orthopaedic Foot & Ankle Society (AOFAS) scoring system for the ankle and hindfoot. RESULTS: A total of 31 patients (22 male, 9 female; mean age, 27.58 ± 8.69 years [range, 18.00-45.00 years]) fulfilled the inclusion criteria. There was no significant difference in ankle eversion strength at the donor site compared with the contralateral site (P = .55), with means of 65.87 ± 7.63 N and 66.96 ± 8.38 N, respectively. Also, there was no significant difference in ankle first ray plantarflexion strength at the donor site compared with the contralateral site (P = .68), with means of 150.64 ± 11.67 N and 152.10 ± 12.16 N, respectively. The mean FADI score of 99.71 ± 0.57 and mean AOFAS score of 98.71 ± 3.03 at the donor site were considered excellent results. CONCLUSION: Ankle eversion and first ray plantarflexion strength at the donor site were similar to those at the contralateral healthy site, with no donor site morbidity. This suggests that the peroneus longus tendon is a promising graft in ACL reconstruction.