The Relation Between Tunnel Widening and Bone Mineral Density After Anterior Cruciate Ligament Reconstruction: An Experimental Study in Sheep

Meller, Rupert; Neddermann, Alexandra; Willbold, Elmar; Hesse, Eric; Haasper, Carl; Singh, Anshu; Knobloch, Karsten; Krettek, Christian; Hankemeier, Stefan

doi:10.1016/j.arthro.2009.08.025

« Previous Next »Arthroscopy: The Journal of Arthroscopic and Related Surgery
Volume 26, Issue 4 , Pages 481-487, April 2010

The Relation Between Tunnel Widening and Bone Mineral Density After Anterior Cruciate Ligament Reconstruction: An Experimental Study in Sheep

Rupert Meller, M.D.
- Trauma Department, Hannover Medical School, Hannover, Germany
- Address correspondence and reprint requests to Rupert Meller, M.D., Trauma Department, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
Alexandra Neddermann, D.V.M.
- Orthopaedic Department, Hannover Medical School, Hannover, Germany
Elmar Willbold, M.D.
- Orthopaedic Department, Hannover Medical School, Hannover, Germany
Eric Hesse, Ph.D.
- Trauma Department, Hannover Medical School, Hannover, Germany
Carl Haasper, M.D.
- Trauma Department, Hannover Medical School, Hannover, Germany
Anshu Singh, M.D.
- Harvard Shoulder Service, Boston, Massachusetts, U.S.A.
Karsten Knobloch, M.D.
- Department of Plastic, Hand, and Reconstructive Surgery, Hannover Medical School, Hannover, Germany
Christian Krettek, M.D., F.R.A.C.S.
- Trauma Department, Hannover Medical School, Hannover, Germany
Stefan Hankemeier, M.D.
- Trauma Department, Hannover Medical School, Hannover, Germany

Received 19 March 2009; accepted 30 August 2009. published online 17 February 2010.

Purpose

The aim of this study was to analyze the relation between bone mineral density (BMD) and femoral tunnel enlargement (TE) in a previously validated sheep model of soft-tissue anterior cruciate ligament (ACL) reconstruction.

Methods

Thirty sheep underwent ACL reconstruction by use of a soft-tissue graft at the age of 4 months. Graft fixation was achieved with the EndoButton (Smith & Nephew Endoscopy, Andover, MA) and Suture Washer (Smith & Nephew Endoscopy). Six animals were killed at 0, 3, 6, 12, and 24 weeks postoperatively. Each ACL-reconstructed knee was examined both by computed tomography to analyze the bone tunnel cross-sectional area and by dual-energy x-ray absorptiometry to analyze BMD.

Results

There was a significant increase in tunnel cross-sectional area. BMD decreased significantly within the first 3 weeks after surgery and increased thereafter. A positive correlation between TE and BMD was found. However, a subgroup analysis showed that there is no influence of BMD on the development of a tunnel widening.

Conclusions

The hypothesis that a TE would be associated with a loss in BMD was not confirmed. Tunnel widening during the first 6 months after ACL reconstruction is not affected by the transient changes in BMD.

Clinical Relevance

There is no correlation between TE and BMD in an experimental sheep model of ACL reconstruction. Translational investigations will determine whether this is also true in humans.