We report the operative technique and results of a new method of central grafting for persistent nonunion of the tibial shaft. The operation is performed through a lateral approach, anterior to the fibula. Fresh autogenous bone from the iliac crest is used to form a central bridge between the tibia and fibula above, below and at the level of the nonunion. In 48 tibiae, most with long-standing nonunion and some with infection or bone defects, sound healing was obtained in 45 after one operation. Only one failure needed amputation.
In 139 patients with burst fractures of the thoracic, thoracolumbar or lumbar spine, the least sagittal diameter of the spinal canal at the level of injury was measured by computerised tomography. By multiple logistic regression we investigated the joint correlation of the level of the burst fracture and the percentage of spinal canal stenosis with the probability of an associated neurological deficit. There was a very significant correlation between neurological deficit and the percentage of spinal canal stenosis; the higher the level of injury the greater was the probability. The severity of neurological deficit could not be predicted.
1. In ten healthy young men an experimental paralysis of the supraspinatus muscle was induced with the aid of Xylocaine injected in or near the suprascapular nerve. 2. The completeness of the paralysis was checked by electromyography. 3. With the supraspinatus muscle completely eliminated, all subjects could move the arm against gravity through its full range in the shoulder joint, though the force and the power of endurance during abduction were diminished. 4. It is concluded that the role of the supraspinatus muscle is of a quantitative nature only.
1. The effects of heavy training on a skeletal muscle have been studied in the rat. After denervation of the triceps surae muscle the tendon of the plantaris muscle was implanted into the tuberosity of the calcaneum. It was then possible to demand an unusual performance of the plantaris, the weight of which is only 18 per cent of the weight of the triceps surae. 2. Formation of new muscle fibres was observed after prolonged heavy training. This is incontrast to the opinion of most investigators, who have seen no new fibres formed after training. Degenerative changes followed by regeneration were also seen. 3. The trained muscle could almost double its weight, and treble its force. Paradoxically, the supposedly non-contractile sarcoplasm was seen to have increased after training. 4. Training induced a strong protein synthesis in muscle. In normal muscle protein synthesis can hardly be demonstrated. 5. Connective tissue grew between single muscle fibres in the heavily trained muscle. Its distribution was unequal. 6. Heavy exercise caused marked swelling of an untrained muscle. 7. Functional recovery was satisfactory after the operation. This showed that a muscle can be replaced by one only one-fifth its weight, provided the latter is trained adequately. 8. Not even the most arduous training could inflict permanent damage on the muscle.
