Reponse Of Tendons To Limb Lenghtening
Response of the tendon during limb lengthening.
Szöke G, Lee SH, Simpson AH, Prescott J.
University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, Scotland, UK.
J Bone Joint Surg Br. 2005 Apr;87(4):583-7
”Little is known about the increase in length of tendons in postnatal life or of their response to limb lengthening procedures. A study was carried out in ten young and nine adult rabbits in which the tibia was lengthened by 20% at two rates 0.8 mm/day and 1.6 mm/day. The tendon of the flexor digitorum longus (FDL) muscle showed a significant increase in length in response to lengthening of the tibia. The young rabbits exhibited a significantly higher increase in length in the FDL tendon compared with the adults. There was no difference in the amount of lengthening of the FDL tendon at the different rates. Of the increase in length which occurred, 77% was in the proximal half of the tendon. This investigation demonstrated that tendons have the ability to lengthen during limb distraction. This occurred to a greater extent in the young who showed a higher proliferative response, suggesting that there may be less need for formal tendon lengthening in young children.”
PMID: 15795216 [PubMed - indexed for MEDLINE]
Biomechanical properties of tendons during lower-leg lengthening in dogs using the Ilizarov method
B. FinkCorresponding Author Contact Information, a, G. Schwingerb, J. Singera, G. Schmielauc and W. Rüthera
Journal of Biomechanics
Volume 32, Issue 8, August 1999, Pages 763-768
Ten dogs were provided with a circular fixator. Segment resection of the fibula and tibial osteotomy in the right lower leg was performed. 5 days after surgery, a lengthening of the right lower leg by 2.5 cm was performed on 6 dogs using a distraction rate of 0.5 mm, twice per day. 3 dogs with leg lengthening and 2 dogs of the control group without leg lengthening were sacrificed at the end of the distraction phase of 25 days and the remaining dogs after another 25 days. Postmortally the tendons of the tibialis anterior, extensor digitorum longus, peroneus longus and the achilles tendon were taken from the operated right side and the left non-operated control side and were examined biomechanically in cyclic tests. The control group without lengthening showed no changes in the biomechanical properties in the tendons of either side nor in those of the unlengthened left side of the operated dogs. In contrast the biomechanical tests revealed a marked decrease of the elastic modulus, an increase of distraction length and an increase of modulus reduction on the lengthened side compared to the non-operated left side.
Journal of Bone and Joint Surgery - British Volume, Vol 88-B, Issue 12, 1666-1669.
Relative ability of young and mature muscles to respond to limb lengthening
T. Shisha, MD, PhD candidate, General Practitioner1; S. Kiss, MD, Orthopaedic Surgeon1; K. Pap, MD, PhD candidate, General Practitioner1; H. Simpson, MD, PhD, DM(Oxon), Professor, Orthopaedic Surgeon2; and G. Szöke, MD, PhD, MSc(Oxon), Assistant Professor, Orthopaedic Surgeon1
“The response of the muscle is critical in determining the functional outcome of limb lengthening. We hypothesised that muscle response would vary with age and therefore studied the response of the muscles during tibial lengthening in ten young and ten mature rabbits. A bromodeoxyuridine technique was used to identify the dividing cells.
The young rabbits demonstrated a significantly greater proliferative response to the distraction stimulus than the mature ones. This was particularly pronounced at the myotendinous junction, but was also evident within the muscle belly.
Younger muscle adapted better to lengthening, suggesting that in patients in whom a large degree of muscle lengthening is required it may be beneficial to carry out this procedure when they are young, in order to achieve the optimal functional result.”