Volume 17, Issue 2 , Pages 189-195, February 2001
Interarticular bone tunnel healing☆☆☆★
Abstract
Purpose: To evaluate the healing behavior of an interarticular bone tunnel exposed continuously to a synovial environment. Type of Study: Experimental in vivo animal model. Methods: Twenty-six adult rabbits had 3.2-mm diameter tunnels drilled in the femur and tibia of both hind-limb stifle joints parallel to but without violation of the native anterior cruciate ligament (ACL). The animals were euthanized at 1, 2, 4, and 12 weeks postoperatively. Decalcified sections were made of the bone tunnels and new bone formation was computer quantified using histomorphometric methods at each time interval. Results: In this model, bone tunnel healing velocity was most rapid between 1 and 2 weeks after surgery. Both femoral and tibial interosseous tunnels showed substantial bone ingrowth (71% of bone tunnel volume) by 2 weeks postoperatively. The peripheral tunnel segment, that third of the tunnel furthest from the joint surface, healed rapidly and was 99% occluded with bone (99% confidence interval, 93.7% to 100%) at 2 weeks. Tunnel ingrowth was delayed and incomplete in the articular third of the tunnel, especially the femoral side. At 12 weeks, by volume, only 69.1% (99% confidence interval, 52.3% to 85.7%) of the interarticular third of the femoral tunnel was ingrown with new bone. Peripheral third bone tunnel healing was significantly greater than articular third tunnel healing at all time intervals; P <. 005 for the femoral and P <. 05 for the tibial tunnel. Conclusions: Interarticular bone tunnels heal from the outside in. At 12 weeks, bone healing was slower and incomplete in the articular segment of the tunnel, closest to the joint surface. The same biologic factors that impede intersubstance ACL healing may interfere with bone tunnel healing and be another cause of bone tunnel enlargement after ACL reconstruction.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 2 (February), 2001: pp 189–195
Keywords: ACL reconstruction, Bone tunnel healing, Interarticular ligament, Synovial environment
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☆ Supported in part by a grant from the Southern Medical Association, Birmingham, Alabama.
☆☆ This paper was awarded the 1999 Achilles Sports Medicine Research Award sponsored by the International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine, and Air Cast Incorporated, Summit, New Jersey.
★ Address correspondence and reprint requests to Eugene E. Berg, M.D., New Hampshire Bone & Joint Institute, 48 Constitution Dr, Bedford, NH 03110, U.S.A.
PII: S0749-8063(01)50374-6
doi:10.1053/jars.2001.20958
© 2001 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
Volume 17, Issue 2 , Pages 189-195, February 2001
