Numerous studies have examined the biomechanical properties of the vertebral body following PMMA cement augmentation for the treatment of osteoporotic vertebral body fractures. To date there is no published literature reporting the effects of Vertebroplasty on internal intervertebral disc biomechanics which in turn have been shown to reflect loading patterns of the vertebral column. To study effects of PMMA cement augmentation of vertebral body fractures on intervertebral disc biomechanics using stress prolifometry to assess differential anterior and posterior vertebral column loading. Eight cadaveric motion segments were individually loaded on a hydraulically powered materials testing machine under 1.5kN of axial compression. Following fracture induction the lower vertebral body underwent Vertebroplasty. Profiles of the vertically acting compressive stress were obtained by pulling a pressure sensitive transducer along the mid-sagittal diameter of the intervertebral disc. “Stress profile” measurements were obtained before fracture, following fracture, and after vertebro-plasty both in extension and flexion. Stress profiles were integrated over area to calculate the compressive force across the disc. The compressive load acting on the neural arch was calculated by subtracting the disc force from the applied 1.5kN load. In flexed postures posterior column loading increased from 17.1% to 42.2% following fracture (p<
0.01) and then decreased significantly from 42.2% to 23.68% following vertebroplasty (p<
0.03). There was no significant difference between pre-fracture and post-vertebroplasty status (p=0.11). In extended posture, fracture produced increased posterior column loading 72.9% vs 51.8% (p<
0.005) and following vertebroplasty there was no significant change (p=0.2). In moderate degrees of flexion, vertebroplasty produces normalisation of load bearing through the anterior vertebral column and hence offloads the posterior elements to a significant degree. This could be postulated, to partly account for the analgesic effect seen following vertebroplasty in the clinical setting.
The rehabilitation of elderly patients after hip fractures is important: we report a prospective study which compares supported home rehabilitation with management in hospital in two similar groups of patients. Our results show that early discharge from hospital and home rehabilitation produces substantial savings in bed days, and also provides quicker and more effective recovery.
We have reviewed 50 patients at a mean period of 2.7 years after operations to restore elbow flexion lost as a result of traction injuries of the brachial plexus. A variety of operations were used and, in general, patient satisfaction was high. Objectively, however, the power in the transferred muscles was poor; less than half of the patients had a significant improvement in function. Poor control of the shoulder often compromised the result. Latissimus dorsi and triceps transfers proved most reliable, and some Steindler flexorplasties also gave satisfactory results. Pectoralis major transfers were disappointing and we do not recommend their use in women.
Six mechanisms which may produce fracture-separation of the proximal humeral epiphysis are proposed. Four of them are illustrated by case reports. It is suggested that they may be differentiated by examination of the patient and study of the radiographs. In unstable fractures manipulation is indicated and, if performed with an understanding of the mechanism of injury, will produce a stable reduction.
Fifty-four hips converted to low friction arthroplasty between 1965 and 1975 have been reviewed one to eleven years after operation. In many cases malposition had led to degenerative changes in the opposite hip, the lumbar spine or the knee, often with severe loss of function due to pain. It was found that total replacement could give useful relief of pain and improved function, though the range of movement obtained was not as good as in primary replacement. An outstanding feature was the correction of inequality of leg length. In general, the results were much better in cases of ankylosis acquired in adult life than in cases of spontaneous fusion after sepsis in childhood. The most important complication was a single case of sciatic palsy.