Post-operative complications following primary ACL reconstruction using allogenic and autogenic soft tissue grafts: increased relative morbidity risk is associated with increased graft diameter.

BACKGROUND: The purpose of this study is to compare the risk of peri-operative complication events associated with allogenic and autogenic grafts during routine follow-up for six months after primary arthroscopic anterior cruciate ligament (ACL) reconstruction surgery. METHODS: A retrospective cohort study identified patients that underwent ACL reconstruction via an arthroscopically assisted single tunnel technique. Fixation was primarily cortical suspension (endobutton) from the femora and bicortical fixation (Washer-loc) in the tibia. Patients were monitored for six months following surgery. Morbidity was defined as complications during this period requiring medical or surgical intervention. Risk of complications was compared according to tissue type and patient characteristics. The Cochran-Mantel-Haenszel method was applied to estimate risk ratios (RR) and confidence intervals (CI) as the measure of association between graft type and morbidity risk. RESULTS: The cohort included 413 eligible patients. Sixty six percent received allograft tissue, while the remainder received autograft tissue. Morbidity risk was 7.0% among patients receiving allograft tissue and 2.8% among patients receiving autograft tissue. Allograft demonstrated elevated risk of complication versus autograft (RR=2.3 (95% CI: 0.9-7.2)), though the data are of borderline significance (p=0.11). Complications were associated with larger graft diameter in comparison to patients who experienced no complication (9.0+/-1.2 mm v. 8.4+/-1.0mm, p=0.005). CONCLUSION: The relative morbidity risk was about two-fold greater among patients receiving allograft tissue. Regardless of tissue type, graft size was larger among patients who experienced a complication. LEVEL OF EVIDENCE: Level III.

Osseous Integration after Fresh Osteochondral Allograft Transplantation to the Distal Femur: A Prospective Evaluation Using Computed Tomography.

OBJECTIVE: Fresh osteochondral allograft transplantation (OCA) is an increasingly available option for patients with damage to the bone-cartilage complex of the distal femur. This study prospectively assesses osseous integration and early clinical results following fresh OCA with single or multiple cylindrical grafts to the femoral condyle. DESIGN: Patients with grade 4 International Cartilage Repair Society (ICRS) defects of the distal femur were treated with OCA. Outcome measures were collected preoperatively and postoperatively at 6, 12, and 24 months. Computed tomography (CT) scans obtained at 6 months were used to assess degree of osseous incorporation regionally. RESULTS: Thirty-four patients, with a mean age of 34.5 years (range, 15-61), with a mean femoral osteochondral lesion of 5.7 cm(2) (range, 1.5-15.0) due to focal osteoarthritis, osteochondritis dissecans, and avascular necrosis, are reported. Statistically significant (P < 0.05) mean improvement in outcome scores at 2 years included Knee Injury and Osteoarthritis Outcomes Score (KOOS) pain, sports and recreation, quality of life, and International Knee Documentation Committee (IKDC). CT imaging indicated grafts implanted to direct weightbearing regions had >75% incorporation (20/26 grafts) compared to <50% incorporation in the indirect weightbearing regions (8/14 grafts). A greater degree of incorporation and earlier outcome improvement were found after single (n = 23) compared to multiple (n = 11) grafts. CONCLUSION: CT scans were used to assess osseous incorporation of fresh osteochondral allografts in a cohort that showed significant improvements after 2 years. Single-graft implantation is associated with stable incorporation of a greater percentage of the graft. Lesser incorporation appears more frequently with grafts in posterior indirect weightbearing regions of the condyle and multiple contiguous grafts.