Abstract
Background
No studies have been conducted to clarify an in vivo remodeling of the radiofrequency-treated lesion of the anterior cruciate ligament.
The purpose was to determine in vivo effects of radiofrequency shrinkage on mechanical properties of the anterior cruciate
ligament.
Methods
Thirty skeletally mature rabbits were used. In each group, radiofrequency energy set
at non-ablative levels was applied to the posterolateral bundle of the anterior cruciate
ligament with a bipolar radiofrequency generator. All animals were sacrificed at 0,
6, and 12 weeks after surgery, respectively. In each group, 7 and 3 out of the 10
specimens were used for biomechanical and histological evaluations.
Findings
After shrinkage treatment, the anterior–posterior translation of the knee and the
length of the posterolateral bundle were significantly reduced immediately after surgery,
but that this effect disappeared at 6 weeks. The tensile strength and the tangent
modulus of the treated bundle were significantly lower than that of the normal control
bundle at each period. In addition, the tensile strength and the tangent modulus measured
at 12 weeks were significantly lower than that at 0 week. Histological examination
showed granulation-like tissues with numerous plump fibroblasts and inflammatory cells
were dominantly found in the midsubstance of the posterolateral bundle at 12 weeks.
Interpretations
This result suggested that the anterior cruciate ligament tissue shortened with the
radiofrequency treatment is elongated gradually over time. The mechanical properties
of the posterolateral bundle of the anterior cruciate ligament reduced by the radiofrequency
shrinkage are not restored in vivo, but significantly deteriorated with time.
Keywords
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Article info
Publication history
Published online: August 28, 2007
Accepted:
July 3,
2007
Received:
April 3,
2007
Footnotes
☆This paper was presented at the 50th Annual Meeting of the Orthopaedic Research Society, San Francisco, CA, USA, March 2004.
Identification
Copyright
© 2007 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
