J Bone Joint Surg Br
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J Bone Joint Surg Br · May 2003
Dorsal root ganglion neurones with dichotomising afferent fibres to both the lumbar disc and the groin skin. A possible neuronal mechanism underlying referred groin pain in lower lumbar disc diseases.
Dorsal root ganglion neurones with dichotomising axons are present in several species and are considered to play a role in referred pain. Clinically, patients with lesions in the lower lumbar discs occasionally complain of pain in the groin. ⋯ Our results showed that the double-labelled neurones had peripheral axons which dichotomised into both the LS-L6 disc and the groin skin, indicating the convergence of afferent sensory information from the disc and groin skin. Our findings provide a possible neuroanatomical mechanism for referred groin pain in patients with disc lesions.
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J Bone Joint Surg Br · May 2003
Comparative StudyZirconia and alumina ceramics in comparison with stainless-steel heads. Polyethylene wear after a minimum ten-year follow-up.
Although alumina has been used in orthopaedic surgery since the 1970s, the long-term clinical results of zirconia have not been well documented in vivo. We studied hips with these two different ceramics during the same period and with a minimum follow-up of ten years. Because the size of the alumina and zirconia heads was different, hips with 32 mm alumina heads and those with 28 mm zirconia heads were compared with control hips with stainless-steel heads of the same size. ⋯ This change was associated with an increase in the surface roughness. A change in the roundness with an increase in the sphericity deviation was also observed both in the articular and non-articular parts of the femoral heads. The increase in rate of wear in the zirconia group was only evident after eight years and may be linked to a long-term biodegradation of zirconia in vivo, associated with the altered roughness and roundness which was observed on the retrieved heads.