Abstract
Objective: Bone-patellar tendon-bone (BPTB) and Achilles tendon allografts have been widely used in primary and revision ACL reconstructions showing good results comparable to those with autografts. The literature is sparce with regard to treatment and results of primary ACL reconstruction using Achilles tendon alone. The objective of this study was to present the clinical outcome of 50 consecutive primary ACL reconstructions with Achilles allograft utilizing interference screws fixation. Particular attention was dedicated to the incidence of tunnel widening and graft rejection phenomenon.
Methods: Fifty consecutive patients had primary ACL reconstruction using fresh frozen Achilles tendon allografts from 1997 to 1998 at our institution. All grafts were sterilely harvested and none of them were subjected to secondary sterilization. All procedures were performed using interference screws fixation. A two-year minimum follow-up study was conducted in all of the patients: clinical and functional evaluation was performed according to the International Knee Documentation Committee (IKDC) by an independent examiner. All patients were evaluated using the KT-1000 arthrometer at 30 pounds of force: data was reported as an injured-to-uninjured difference. Lateral and 45° posteroanterior weightbearing radiographs were performed in each patient. The sclerotic margins of the tibial tunnel were measured at the widest dimension by a single observer and were compared with the initially drilled tunnel size.
Results: According to the IKDC rating system, the overall outcome was normal or nearly normal in 96% of the patients. Forty-eight patients had a 30 pound side to side difference £ 5 mm. None of the patients had greater than a 10 mm difference. There was no evidence of graft rejection from an immune response or disease transmission. On the femoral side, all bone plugs appeared to be incorporated radiographically. The average allograft tibial tunnel enlargement at the widest level was 1.9 mm (0 to 5 mm) in the posteroanterior view and 1.7 mm (−0.2 to 5 mm) in the lateral view.
Conclusion: Our results suggest that fresh frozen Achilles tendon allografts represent a good alternative in primary ACL reconstructions. No significant difference was seen in KT-1000 arthrometer measurements and clinical outcomes between patients with different tibial tunnel widening. We believe that fixation with interference screws could reduce the incidence of this undesirable phenomenon.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
