Anatomic Lateral Collateral Ligament Reconstruction Graft Options: Clinical and Radiographic Outcomes of Autograft versus Allograft

OBJECTIVES: As awareness of lateral knee pathology has increased, surgical outcomes for lateral collateral ligament (LCL) reconstruction and posterolateral corner reconstructions have improved. Despite reliable improvement in results, no study to date has compared the radiographic or clinical outcome of lateral knee reconstruction procedures when comparing autograft versus allograft reconstruction options. To evaluate patient reported outcomes and radiographic outcomes following anterior cruciate ligament (ACL) reconstruction with isolated LCL anatomic reconstruction, comparing the use of autografts versus allografts for LCL reconstruction. The null hypothesis was that there would be no significant differences in clinical outcomes at 2-year follow up and no differences in LCL insufficiency as defined by a side-to-side difference of greater than 2.1mm in varus stress radiographs at minimum of 6-month follow up. METHODS: All patients who underwent primary ACLR with concomitant isolated LCL reconstruction from 2010 to 2017 by a single surgeon were retrospectively identified; clinical characteristics and graft choice for LCL reconstruction was collected. Patients with minimum 2-year follow up clinical outcome scores and 6-month bilateral varus stress radiographs were included. Patients with any other ligamentous procedure or revision ACL reconstruction were excluded. An a priori power analysis demonstrated a minimum group size of 18 patients per group to detect a difference in LCL insufficiency. RESULTS: There were 58 primary ACLR with concomitant LCL reconstruction patients identified that met inclusion criteria. Thirty-nine patients underwent LCL reconstruction with semitendinosus autograft compared to 19 patients with allograft (16 semitendinosus and 3 tibialis anterior). At a minimum 6-month radiographic varus stress x-ray follow-up, there was no significant difference in LCL graft reconstruction failure (>2.1 mm) between autograft and allograft (autograft 0/39 vs allograft 0/19). There was also no absolute side-to-side difference of stress x-ray gapping between the two cohorts (allograft= 0.49 mm and autograft= 0.15 mm, p= 0.22). Furthermore, there was no difference when comparing the autograft to allograft group at minimum 2-year clinical outcome follow-up for SF-12 Mental Component Score (MCS) and Physical Component Score (PCS), WOMAC (Total, pain, stiffness, activity), Tegner, and Lysholm scores. Lastly, patient satisfaction between allograft and autograft groups showed no significant difference at average follow-up of 3.6 years. There were no significant differences in clinical knee stability between groups at final follow-up (p >0.05). CONCLUSION: In the largest reported series comparing autograft and allograft lateral collateral ligament reconstructions, we found that both autograft and allograft LCL reconstructions offer reliable and similar radiographic and clinical results. As a result, surgeons may discuss the risks and benefits of both graft options with the patient and come to a decision through a shared decision-making process knowing that both grafts will provide reliable outcomes.