Spinal fusion in Duchenne muscular dystrophy.

Sixty-eight patients from a clinical population of 183 patients with Duchenne muscular dystrophy underwent posterior spinal fusion with instrumentation for progressive spinal deformity. Pulmonary complications were the most common postoperative problem, occurring in 17 per cent of the patients. A 35 per cent normal forced vital capacity was a reliable indicator of pulmonary complication risk. The patients with surgically stabilized spines were more comfortable in the later years of life and easier to care for, but deteriorating pulmonary function was not affected by the spinal fusion. The average age at death for the 29 boys who underwent spinal fusion was 18.3 years, which was similar to that of the 58 boys with scoliosis. Factors that improved the patients' quality of life included segmental instrumentation, fusion from T2 to the pelvis, correcting or balancing scoliosis, creating normal sagittal plane alignment and correcting pelvic obliquity.

Height measurement of patients with neuromuscular disease and contractures.

Patients with neuromuscular diseases frequently have joint contractures, which preclude standard measurements of standing height. Standing height, arm-span, forearm and ulnar-segment measurements were taken of 116 normal children without contractures. Measurement of the forearm segment had the highest correlation with standing height, but it requires a special ruler. Arm-span measurement had good correlation with standing height, although this cannot be used if elbow or shoulder contractures are present; in such patients ulnar segment measurement can be used, but it has the lowest correlation with standing height.

Pelvic anatomy relative to lumbosacral instrumentation.

Anatomical study of 72 pelves revealed that the most substantial area of bone that could best support a rod for surgical fixation is the body of the ilium, with the best part of the bone being the area above the sciatic notch. Placement of the rods into the body of the ilium provides good fixation but requires complex bending of the rods and a good three-dimensional perception of the osseous anatomy of the pelvis. This study was undertaken to define the intraosseous anatomy and the range of anatomical variation of the ilium. The results of this study are useful in developing a prebent spinal fixation rod, providing a better understanding of this anatomical area from a three-dimensional perspective and providing better lumbosacral spinal instrumentation.

Unit rod segmental spinal instrumentation in the management of patients with progressive neuromuscular spinal deformity.

Thirty-four nonambulatory patients with progressive neuromuscular spinal deformity were surgically managed using a 1/4" U-shaped double rod construct with segmental instrumentation from T2 to the pelvis accompanied by posterior spinal fusion. Diagnoses included 17 patients with cerebral palsy, six with spinal bifida, and 11 with other diseases (spinal muscular atrophy, Friedreich's ataxia, polyneuropathy, nemaline myopathy, and polio). Twenty-three patients had single uncompensated thoracolumbar curves, and 11 had a double curve pattern. The mean preoperative major curve was 66 degrees (range, 22-132 degrees), the secondary curve 58 degrees (range, 23-84 degrees). No postoperative spinal support was used. Mean curve correction was 36 degrees or 54.6%. There were four major complications, including two implant failures requiring revision and two patients sustaining excessive intraoperative blood loss necessitating completion of the procedure in a second stage. There were two neurologic complications including one case of postoperative seizures and an L4 monoradicular neuropathy in a spina bifida patient. Four patients had temporary postoperative ileus, one gastroesophageal reflex, and four had urinary tract infections. There were no significant postoperative pulmonary complications. Excluding the patients with rod failure, mean loss of correction at mean follow-up of 21.3 months was 6.5%. The stability and curve correction obtained using this system supports its continued use in patients with progressive neuromuscular scoliosis.

Progression of scoliosis in Duchenne muscular dystrophy.

We reviewed the clinical charts and spinal radiographs of fifty-one boys who had Duchenne muscular dystrophy, had not had surgical treatment of the spine, and had been followed until death. All had scoliosis. None of the following variables was useful in predicting which curves would become severe: age when the patient initially walked, age when he ceased walking, age at onset of spinal collapse, surgical release of the iliotibial bands, or age at the time of death. Radiographs were made within eighteen months before death for thirty-three patients; in thirty-one of them, the final curve exceeded 40 degrees and in seventeen, 90 degrees. For the remaining eighteen patients, final radiographs were made more than eighteen months before death; at that time, eight of them already had a curve of more than 90 degrees. Although there was a relationship between extension of the lumbar spine and severity of scoliosis at the time of final follow-up, early maintenance of the lumbar spine in extension rarely prevented the development of a severe curve. For most of the patients who had a severe curve, sitting was difficult and was accompanied by breakdown of the skin and pain. When a patient's curve exceeded 35 degrees, the vital capacity usually was less than 40 per cent of the predicted normal value. Therefore, when walking becomes impossible for boys who have Duchenne muscular dystrophy, routine spinal arthrodesis should be considered.

Hypercapnia in relation to pulmonary function in Duchenne muscular dystrophy.

Arterialized blood gases were analyzed in 143 patients with Duchenne muscular dystrophy (DMD) to assess the relationship between forced vital capacity (FVC) and hypercapnia. The majority of patients studied had PaCO2 values in the low or normal range. Only six older patients had hypercapnia (PaCO2 greater than or equal to 45 mm Hg), and all these patients had FVC values less than or equal to 40% predicted. We conclude that hypercapnic respiratory failure occurs as a late preterminal event in DMD.

Pulmonary function and scoliosis in Duchenne dystrophy.

Pulmonary function data were evaluated in 68 Duchenne muscular dystrophy patients to determine the rate of decline of the percentage of normal forced vital capacity (FVC). The percentage of normal FVC declined most rapidly during the adolescent growth spurt, which demonstrated a need for an accurate and reliable means for determining height in these patients. The age at 35% of normal FVC was 14.9 +/- 3.6 years (2 SD), and survival for the 28 patients who died was 3.2 (range 0.2-5.7) years. Pulmonary function tests were performed 10-74 months after spinal stabilization on 21 Duchenne dystrophy patients and compared with 46 nonfused scoliotic Duchenne patients. No difference was found in the rate of deterioration of the percentage of normal FVC.

Limb swelling after release of a tourniquet.

Using a water displacement method the authors found that an exsanguinated human limb will swell immediately by approximately 10% of its original volume after release of a pneumatic tourniquet. Exsanguination reduces limb volume by forcing blood from it. Approximately one-half of the post-tourniquet swelling is due to the return of the exsanguinated blood volume to the limb. Reactive hyperemia accounts for the remainder of the swelling the authors measured. Subsequently, additional swelling can occur from both hematoma formation and the accumulation of postanoxic edema fluid. In some cases, the placement of a circumferential postoperative plaster on a limb prior to tourniquet release may be a hazardous procedure.

Pin placement in slipped capital femoral epiphysis.

Standard radiographs taken at right angles to each other during the pinning of a slipped capital femoral epiphysis may not demonstrate pins protruding into the joint. In this study roentgenograms of 110 patients (148 hips) with slipped capital femoral epiphyses were analysed by a three-dimensional mathematical model of the femoral head and pin position. A computer was used to determine the spatial distance between the tip of the pin and the subchondral bone of the femoral head. Pin protrusion was found in 41 hips. In 22, protrusion was sufficient to have transgressed the joint space. Pin protrusion did not, however, appear to increase the risk of chondrolysis.

Muscle growth in normal and spastic mice.

Longitudinal muscle growth was studied in normal and spastic mice. Muscle growth takes place at the musculotendinous junction--the 'muscle growth-plate'. In spastic mice muscle growth is reduced by 45 per cent, resulting in contractures.

Seating for children with cerebral palsy.

Special seating enables children with even the most severe forms of cerebral palsy to sit comfortably. A straight spine and mobile hips are desirable. Prevention of hip dislocation by operation, or release of a hip extension contracture, is required for 40% of the younger children. Surgical correction of scoliosis is required for 20% of the older ones. Seating problems may be classified by (a) ability--hands free, hand dependent or propped--(b) the pattern of deformity--symmetrically slouched or windswept--and (c) severity of deformity--none, amenable to surgery, or beyond surgery. Each of these categories requires a different therapeutic approach.

Internal fixation of slipped femoral capital epiphyses.

The problems related to internal fixation for the treatment of slipped femoral capital epiphyses were reviewed in 164 cases and by a questionnaire of 59 orthopedic surgeons. Significant problems were reported with all fixation devices. With Trifin nails, the main difficulty was getting them to stay in in place. With threaded pins, there was difficulty removing them. The best fixation was obtained with the cast Vitallium Knowles pin, but it requires additional modification and improvement.

A simple approach to standardized spinal radiographs.

Present methods of obtaining spine radiographs for the clinical assessment of scoliosis are inadequate. Routine quantitative measurements made on anterior-posterior (A-P) and lateral radiographs describing the spinal deformities are grossly inaccurate since they are two-dimensional measurements of three-dimensional deformities. The approach described in this paper uses a simple device, the "Throne," which ensures reproducible positioning of patients for sitting spine radiographs as well as exact orthogonality of A-P and lateral film exposures. These two views of the spine form the data in digitized form for input into a computer program which generates the 3-D geometry of the line passing through the centers of each vertebral body from L5 to T1. Parameters describing the 3-D deformities of the spine are calculated automatically and converted to printed form for detailed examination and to plotted form for clinical use. Approximately 80 postambulatory Duchenne muscular dystrophy patients are being followed using this method. Of these, 20 have been followed for periods of 2 to 3 years. Costs of the method are minimal. The "Throne" can be built for approximately $50 of materials and 30 hours of labor. Each set of A-P and lateral radiographs can be processed in less than 5 minutes, including digitizing time at a computer cost of about 50 cents. The computer program may be handled by a minicomputer.

Role of the wheelchair in the management of the muscular dystrophy patient.

During the postambulatory period, patients with pseudohypertrophic muscular dystrophy depend entirely on their wheelchairs for comfort and spinal support. Without the comfort they are unable to enjoy and participate in every waking activity; without the spinal support they are destined to accept a bedbound life, not so much by the actual weakness as by the progression of spinal deformity. Present-day wheelchairs are not comfortable and they do not provide adequate spinal support. A novel spinal support system (brace) has been prescribed for 50 patients during the last 24 months. It consists of a contoured seat, mounted on a modified wheelchair frame, with integral armrests, footrests and headrest. All patients are clearly more comfortable and spend between 9 and 14 hours a day in their special wheelchairs, compared with 2 to 3 hours at a time in standard wheelchairs. Parents, teachers and therapists have reported a definite improvement in the attitudes of these patients. Although we have measured no progression in spinal deformity and have recorded regression in a few patients, we cannot yet assess the final value of this promising method of support in preventing spinal collapse.

A new foam for support of the physically handicapped.

This article is intended to inform professionals in the fields of rehabilitation medicine and biomedical engineering of some of the more significant properities of Temper Foam, a new foam for support of the physically handicapped. The unique properties of this foam are explained in terms of its microstructure, illustrated by scanning electron micrographs and by mechanical tests using an Instron Materials Testing machine. Fourteen non-ambulatory patients with Duchenne muscular dystrophy are using this foam in custom-fitted contoured support systems. Normally, these children show increasing signs of discomfort and skin breakdown due to their inability to alternate areas of weight bearing and high local pressure such as the ischial tuberosities. In our support systems lined with Temper Foam these problems have completely dissappeared. We find that Temper Foam types T-36, T-38 and -41 are ideally suited for patients weighing up to 35 kg. T-41 may be used for patients weighing up to 70 kg.