Original Research
Intraosseous and Extraosseous Attachments of Flexor Tendon to Bone: A Biomechanical In Vivo Study in Rabbits
Am J Orthop. 2009 November;38(11):E170-E172
Author and Disclosure Information
Steven M. Green, MD, and Martin A. Posner, MD
Dr. Green is Clinical Associate Professor of Orthopaedic Surgery, New York University Medical School, New York, New York, and Associate Chief, Hand Service, New York University Hospital for Joint Diseases, New York, New York.
Dr. Posner is Clinical Professor of Orthopaedic Surgery, New York University Medical School, New York, New York, and Chief, Hand Service, New York University Hospital for Joint Diseases, New York, New York.
There are 2 popular methods of repairing flexor tendons to the distal phalanx and attaching a free tendon graft to bone: intraosseous, by implanting the tendon into a bony tunnel, and extraosseous, by suturing the tendon to the cortical surface after elevating the periosteum. An in vivo study was designed to determine whether one method is stronger than the other.
The profundus flexor of the third and fourth toes of the hind paw of adult rabbits was divided and reattached to the middle phalanx using either an intraosseous tunnel or an extraosseous suture. Half the rabbits were killed after 3 weeks, the other half after 8 weeks. Repairs were then tested to failure, using an Instron device, and compared with the same tendons in the nonoperated limbs. The repaired tendons demonstrated similar strength 3 weeks and 8 weeks after surgery but were significantly weaker than the nonoperated tendons.
The importance of this study is that it gives equal credence to these usual methods of tendon attachment.