Journal of Orthopaedic Science

The purpose of this study was to investigate gait characteristics of patients with bilateral hip osteoarthritis (BHO) independent of walking speed. We measured gait parameters in 12 BHO patients during free walking activities and in 12 normal adults during both free walking and slow walking activities using a three-dimensional computerized gait analysis system. Patients with BHO had a lower walking speed, step length, and cadence than normal subjects during free walking. When compared with normal subjects walking at a slow speed, the walking speed difference among BHO patients disappeared, although BHO patients retained a relatively high cadence. Kinematic and kinetic factor analysis of BHO patients at free speed compared to normal subjects walking at a slow speed showed a forward-tilted pelvic angle in the BHO patients that dropped to that of the ipsilateral side during the stance phase. The peak extension and abduction angle of the hip and the peak abduction moment of the hip were all low, whereas the peak generation power of the ankle was high in BHO patients. Gait characteristics of patients with BHO, independent of walking speed, were as follows: (1) increased cadence and ankle generation power; (2) reduced step width, hip extension, and abduction angle as well as a lower hip abduction moment; (3) maintained forward tilting of the pelvis during gait cycle; and (4) appearance of a dropped pelvis during the stance phase.

Recent studies have revealed that the low-affinity nerve growth factor receptor, p75 neurotrophin receptor (p75NTR), is important in inflammatory pain. Moreover, p75NTR immunoreactive sensory nerve and dorsal root ganglion (DRG) neurons have been found to innervate lumbar intervertebral discs. The purpose of the current study was to investigate the effect of p75NTR saporin, a toxin used to destroy p75NTR, on calcitonin gene-related peptide (CGRP), an inflammatory neuropeptide associated with pain, in DRG neurons innervating punctured intervertebral discs in rats. The neurotracer fluorogold (FG) was applied to the surfaces of L5/6 discs to label their innervating DRG neurons (n = 30). Of 30 rats, 10 were in a nonpunctured disc sham surgery control group (nonpuncture group), and the other 20 were in experimental groups in which intervertebral discs were punctured with a 23-gauge needle. p75NTR saporin was applied to the discs of 10 rats (puncture + p75NTR saporin group) and the other 10 received the same volume of saline (puncture + saline group). At 14 days after surgery, DRGs from L1 to L6 were harvested, sectioned, and immunostained for CGRP, and the proportions of CGRP-immunoreactive DRG neurons was evaluated. Of the FG-labeled neurons innervating the L5/6 disc, the proportion of CGRP-immunoreactive neurons was 32% ± 6% (mean ± SE) in the nonpuncture group, 47.2% ± 8% in the puncture + saline group, and 34.6% ± 9% in the puncture + p75NTR saporin group. The proportion of CGRP-immunoreactive neurons was significantly greater in the puncture + saline group compared with the nonpuncture and puncture + p75NTR saporin groups (P < 0.01). Half of the DRG neurons innervating the discs were positive for CGRP in the puncture + saline group. CGRP is important for mediating inflammatory and nerve-injured pain and may be important in discogenic pain. However, p75NTR saporin suppressed CGRP expression in DRG neurons. Therefore, p75NTR may be an important receptor for mediating discogenic pain via CGRP expression.

We report a patient with severe varus deformity and tibial shortening caused by dysplasia epiphysealis hemimelica (DEH), a rare skeletal developmental disorder characterized by an osteocartilaginous tumor arising from an epiphysis in young children. Limb lengtheninig and angular correction was performed successfully, with an excellent result without abnormal bone growth.