We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.

We investigated the effect of progesterone on the nerve during lengthening of the limb in rats. The sciatic nerves of rats were elongated by leg lengthening for ten days at 3 mm per day. On alternate days between the day after the operation and nerve dissection, the progesterone-treated group received subcutaneous injections of 1 mg progesterone in sesame oil and the control group received oil only. On the fifth, tenth and 17th day, the sciatic nerves were excised at the midpoint of the femur and the mRNA expression level of myelin protein P0 was analysed by quantitative real time polymerase chain reaction. On day 52 nodal length was examined by electron microscopy, followed by an examination of the compound muscle action potential (C-MAP) amplitude and the motor conduction velocity (MCV) of the tibial nerve on days 17 and 52. The P0 (a major myelin glycoprotein) mRNA expression level in the progesterone-treated group increased by 46.6% and 38.7% on days five and ten, respectively. On day 52, the nodal length in the progesterone-treated group was smaller than that in the control group, and the MCV of the progesterone-treated group had been restored to normal.

Progesterone might accelerate the restoration of demyelination caused by nerve elongation by activating myelin synthesis.

We produced large full-thickness articular cartilage defects in 33 rabbits in order to evaluate the effect of joint distraction and autologous culture-expanded bone-marrow-derived mesenchymal cell transplantation (ACBMT) at 12 weeks. After fixing the knee on a hinged external fixator, we resected the entire surface of the tibial plateau. We studied three groups: 1) with and without joint distraction; 2) with joint distraction and collagen gel, and 3) with joint distraction and ACBMT and collagen gel.

The histological scores were significantly higher in the groups with ACBMT collagen gel (p < 0.05). The area of regenerated soft tissue was smaller in the group allowed to bear weight (p < 0.05). These findings suggest that the repair of large defects of cartilage can be enhanced by joint distraction, collagen gel and ACBMT.

We performed a paired study of mature patients with Perthes’ disease to compare the radiological results after treatment between conservatively- and surgically-treated groups. One patient was selected from each group to create the pairs for this study. Each pair was strictly matched for gender, body mass index, age at onset, stage at the first visit, necrotic area and radiological at-risk signs and each was assessed by comparing the values of six radiological measurements.

Eighteen pairs (36 hips) fitted the criteria. The radiological measurements which showed a statistically better result in the surgical groups were Mose’s method, the acetabular-head index and leg-length discrepancy. There were no statistical differences in the slope of the acetabular roof and the articulotrochanteric distance. Four hips in the conservative group were in Stulberg class II, five in class III and nine in class IV. In the surgical group, 13 were in Stulberg class II, four in class III and one in class IV.

We conclude that surgical treatment improved the sphericity of the femoral head and provided greater acetabular cover, but did not reform the acetabular roof.

It was noteworthy that a greater leg-length discrepancy and a smaller articulotrochanteric distance were not seen in the surgical group. Our study suggests that surgical treatment is preferable in patients with severe Perthes’ disease.

We describe a method of exposing the whole length of the axillary and suprascapular nerves through a sabre-cut incision. The coracoid process is osteotomised and part of trapezius is detached from its insertions. The posterior deltoid is freed from its scapular origin to expose infraspinatus.

We have used this approach to explore combined injuries of the axillary and suprascapular nerves with good results, and no serious complications. Its success depends on a meticulous surgical technique.

We report the results in 33 patients who had nerve grafting of the axillary or the suprascapular nerve or of both. There were 32 men and one woman; their mean age was 21 years and the average interval between injury and operation was three months.

At a mean follow-up of 27 months, the deltoid had recovered to M3 or better in 23 of 30 patients (77%) and the infraspinatus in 18 of 25 patients (72%). Shoulder elevation had reached 120° or more in 27 patients (82%), with external rotation of 30° or more in 27 (82%). Twenty-six patients (79%) could reach to the top of their head with their hand.

Recovery of muscle strength, range of movement and shoulder function were satisfactory when surgery was performed within four months of the injury. Early exploration and nerve grafting can lead to a good functional recovery, but thorough exploration and careful repair of both nerves are essential.

We have assessed the efficacy of free nerve grafts in 90 cases of brachial plexus injury. Relatively good recovery of the elbow flexor and extensor muscles and of those of the shoulder girdle was found but recovery of the flexors and extensors of the forearm and of the intrinsic muscles of the hand was extremely poor.

Poor results were found when spinal nerve roots seemed normal to the touch and appeared intact but had abnormal somatosensory evoked potentials or myelography. Recovery of the deltoid and infraspinatus muscles was better when injury had occurred to the circumflex and suprascapular nerves rather than to the plexus itself, perhaps because these nerves were explored in their entirety to determine the presence of multiple lesions.

It is important to visualise the entire nerve thoroughly to assess the overall condition. Thorough exploration of the plexus and the use of intraoperative recording of somatosensory evoked potentials are essential.