The role of the intra-articular synovial fold as a source of facet joint pain is unclear, because the nature of nociceptive innervation in lumbar synovial folds is controversial, and there have been no such studies in cervical synovial folds. The present study aimed to demonstrate the presence of nerve fibers including nociceptive fibers in synovial folds of human cervical facet joints using immunohistochemistry. Synovial folds of cervical facet joints removed from patients undergoing cervical spine laminoplasty were analyzed immunohistochernically using antibodies to protein gene product 9.5, p 111-tubulin, substance P and calcitonin gene-related peptide. Many nerve fibers immunoreactive for protein gene product 9.5 and 111-tubulin were demonstrated both around blood vessels and as free fibers in the stroma of the synovial fold. Also, immunostaining showed the presence of free nerve fibers immunoreactive for substance P and calcitonin gene-related peptide in the stroma. The presence of putative nociceptive fibers in cervical synovial folds supports a possible role for these structures as a source of cervical facet joint pain. 0 3001 Orthopaedic Research Society. Published by

Leg lengthening procedure is used increasingly to treat leg length discrepancy and some forms of dwarfism. We investigated adaptation in rat sciatic nerve to the gradual nerve elongation that occurs with leg lengthening. Indirect nerve elongation was produced by leg lengthening by a total of 15, 30, 45, or 70 mm at a rate of 1 m d d a y . One day after leg lengthening completion, transverse semithin sections of sciatic nerve were prepared and examined; a teased-fiber study also was performed. Elongation decreased axon diameter, but not significantly. In teased-fiber preparations, internodal length was increased by 93%, and the longest internode measured 3000 pm after leg lengthening by 70 mm. Slopes of fiber diameter-internodal length regression lines increased with increasing elongation. Paranodal demyelination caused by nerve elongation worsened as elongation increased, stimulating remyelination (i.e., intercalation of a segment). Only 0.8% of axons showed degeneration in the group with 70 mm of elongation. We concluded that adult rat sciatic nerve can adapt itself to leg lengthening procedure with even doubling internodal length.

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A case of neonatal compartment syndrome of the forearm is reported. The cause was thought to be compression during delivery. It not only caused muscle contractures but also affected bone growth. Conservative treatment was given. At the age of 6 years, the muscle contracture had recovered and there was full hand function, but there was growth arrest of the distal radial epiphysis and the affected forearm was shorter than the other.

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