ACL Revision Reconstruction: Results of A Novel Single Stage Approach Using Allograft Dowel Bone Grafting

OBJECTIVES: Failure of ACL grafts poses a substantial challenge to both patient and surgeon. Recent studies regarding ACL revision have shown 24% of failures directly attributable to technical error. Previous mal-position of tunnels and anatomic constraints historically necessitate two stage revision including initial tunnel bone grafting followed by remote ACL reconstruction. Staged revision surgery has an inherently higher complication rate, often diminished outcomes and larger financial burden to the healthcare system. The objective of this study was to evaluate the outcomes of the senior author’s novel single staged technique for ACL revision reconstruction using allograft cloward-dowel type bone grafting of previous tunnels and immediate ACL reconstruction. METHODS: Study Design: Case Series. We reviewed the charts of patients undergoing ACL revision surgery using the single stage technique from 2002-2012. We were able to contact and enroll 14 patients who had subsequent clinical evaluation including cruciate exam, KT 1000 arthrometry, subjective outcome scores and CT evaluation of bone graft incorporation at a mean of 22 months followup. Means and standard deviations were calculated for descriptive data summary. RESULTS: At a mean follow up of 22.2 months (min 4.5mo), CT scans showed excellent graft incorporation in all patients as determined by an orthopaedic surgeon and musculoskeletal radiologist based on ≥75% integration. KT 1000 arthrometry showed mean side-to-side difference between operative and non-operative knees of 0.8mm, and there were no 2+ pivot shift exams in our series. Subjective measures showed mean VAS of 2.6 (SD 2.4), IKDC and KOOS scores were 61.7 (SD 21) and 72.2 (SD 22.1) respectively. CONCLUSION: As illustrated by previous studies, our data shows that revision ACL surgery tends to yield inferior subjective outcomes. However, despite the relatively low mean subjective outcomes scores in our series, the objective outcome measures were very good. We had no failures based on the MARS criteria for ACL revision, the allograft dowels fully incorporated in all patients, and the sided to side difference as measured by KT 1000 was within the range of normal for native knees. This illustrates that a single stage approach to ACL revision reconstruction using this technique yields good reproduction of ACL function. It also supports the use of allograft bone dowels and demonstrates their ability to act as partial fixation for ACL hardware and to integrate very well into the native bone as early as 4.5 months post operatively. Although ACL revision surgery poses a substantial challenge to both patient and surgeon, the ability to perform that surgery in a single stage, regardless of previous tunnel position, helps to limit the morbidity and cost of this procedure.