Clinical and radiological outcome of combined femoral and Chiari osteotomies for subluxed or dislocated hips secondary to neuromuscular conditions: a minimum of 10-year follow-up.

We evaluated the medium-term results of combined Chiari pelvic and femoral osteotomies performed at the Manchester Children's Hospitals between the years 1985 and 1994. The indications for these osteotomies were either hip dislocation or subluxation in children with neuromuscular disease. We clinically and radiologically evaluated 20 hips in 18 patients treated for hip subluxation and dislocation with Chiari osteotomy. The average post-operative clinical follow-up period was 11.32 years (range 10.1-12.9). The mean age at the time of surgery was 7.3 years (range 3.1-13.2 years). Clinically, 9 hips had a 'Good' outcome, 10 were "Fair" and 1 was "Poor" according to Osterkamp criteria. At last follow-up, radiologically the mean Sharp's angle improved from 51° to 44° (p = 0.09), the mean Centre-Edge angle improved from -16° to 18° (p = 0.067), the mean Migration Index improved from 59 to 29 % (p = 0.011), the mean femoral neck-shaft angle from 160° to 117° (p < 0.0001) and the Severin criteria improved from an average grade of 4.5-2.9 (p < 0.0001). Our results compared to previous studies confirm that combined femoral and Chiari osteotomies provide a favourable outcome both clinically and radiologically at least 10 years following surgery. Accepting that the numbers are small, we report no statistical difference in the mean age at the time of operation when comparing the children with an eventual 'good' outcome and those with an eventual 'fair' or 'poor' outcome.

Operative treatment for hip subluxation in spinal muscular atrophy.

Subluxation of the hip is common in patients with intermediate spinal muscular atrophy. This retrospective study aimed to investigate the influence of surgery on pain and function, as well as the natural history of subluxed hips which were treated conservatively. Thirty patients were assessed clinically and radiologically. Of the nine who underwent surgery only one reported satisfaction and four had recurrent subluxation. Of the 21 patients who had no surgery, 18 had subluxation at the latest follow-up, but only one reported pain in the hip. We conclude that surgery for subluxation of the hip in these patients is not justified.

Effect of a bisphosphonate, disodium pamidronate, on the quasi-static flexural properties of Palacos R acrylic bone cement.

Aseptic loosening is a major complication of joint replacements and is thought to be associated with a heavy macrophage infiltrate in response to wear particles. Bisphosphonates are compounds known to inhibit osteoclastic activity and are used to reduce osteolysis in Paget's disease, osteoporosis, and metastatic bone disease. Oral bisphosphonates have also been used to decrease osteolysis and therefore prevent aseptic loosening of joint replacements. It has been suggested that bisphosphonates mixed in bone cement can reduce bone resorption in joint replacement surgery. This would be an excellent therapeutic option to prevent or control osteolysis. The present aim was to study the mechanical properties of a commercially available acrylic bone cement, Palacos R, mixed with the bisphosphonate pamidronate. The liquid monomer of Palacos R was mixed with liquid pamidronate. Two groups of bone-cement strips were produced, one with added pamidronate and one without. The flexural properties of the cement strips were examined. A significant reduction in both the bending modulus and bending strength of the specimens with added pamidronate was found. In conclusion, the use of liquid pamidronate mixed with the acrylic bone cement Palacos R in order to reduce osteolysis is not recommended because of its effect on the mechanical properties of Palacos R.

Progression of scoliosis after spinal fusion in Duchenne's muscular dystrophy.

A consecutive series of 85 patients with Duchenne's muscular dystrophy who underwent spinal fusion over a period of 16 years was followed up with regard to the progression of the scoliosis and pelvic obliquity. Of 74 patients with adequate radiographic follow-up, 55 were instrumented with the Luque single-unit rod system and 19 with the Isola pedicle screw system; seven were instrumented to L3/4, 42 to L5, 15 to S1 and 10 to the pelvis with intrailiac rods. The mean period of follow-up was 49 months (SD 22) before and 47 months (SD 24) after operation. There was one peri-operative death and three cases of failure of hardware. The mean improvement in the Cobb angle was 26 degrees and in pelvic obliquity, 9.2 degrees. Fusion to L3/4 achieved a poorer correction of both curves while intrapelvic rods, achieved and maintained the best correction of pelvic obliquity. Fusion to S1 did not provide any benefit over more proximal fusion excluding the sacrum, with regard to correction and maintenance of both angles. The Isola system appeared to provide and maintain a slightly better correction of the Cobb angle.

Hip subluxation and dislocation in Duchenne muscular dystrophy.

Although hip subluxation and dislocation occur commonly in neuromuscular diseases such as cerebral palsy, spinal muscular atrophy and myelomeningocele, they are not known to commonly affect patients with Duchenne Muscular Dystrophy. In this study, 15 out of 54 patients whose hip radiographs were reviewed showed unilateral subluxation, one had bilateral subluxation and three had unilateral dislocation. Having established that hip subluxation and dislocation develop frequently in patients with Duchenne Muscular Dystrophy, serial hip radiographs should be taken as has been advocated for cerebral palsy. The possible relationship between subluxation and pelvic tilt also calls for better control of sitting posture to prevent pelvic tilt. Spinal stabilization should be carried out at an early age when any scoliosis and pelvic tilt are still mild, so that progressive subluxation of the hip may be delayed or prevented, in addition to maintaining sitting balance and comfort.

Radiological evaluation of surgical treatment in Perthes' disease.

We compared the late radiographic results of femoral head coverage in two unselected groups of patients with Perthes' disease, one treated conservatively and one with surgical containment. Forty-eight hips were treated surgically and 28 hips were managed conservatively. The preoperative radiographs were classified using both the Salter and Herring classifications. We found no significant difference in femoral head coverage between the groups. However, there was a trend towards a better femoral head coverage following surgical containment of Salter type B and Herring type II and III hips. The authors conclude that surgical containment may offer a better prognosis for patients with the more severely affected hips.

Calcium mobilization is required for spreading in human osteoblasts.

Adhesion-induced changes in intracellular calcium concentration ([Ca2+]i) were measured in populations of human osteoblasts spreading on bone matrix proteins. In cells spreading on collagen type I, fibronectin, or laminin, average values for [Ca2+]i were found to increase approximately 2x over baseline and then decline. The speed with which [Ca2+]i increased and declined was dependent upon the matrix protein on which the cells were plated but was generally complete within 1 hour from the time of plating. Calcium mobilization was found to be due to influx of calcium across the osteoblast plasma membrane and was integrin dependent. Carboxyamido triazole (CAI), a specific inhibitor of nonvoltage-dependent calcium channels, or BAPTA-AM, a chelator of intracellular calcium, inhibited osteoblast adhesion and spreading on collagen type I, fibronectin and laminin in a dose-dependent manner. In conclusion, these results demonstrate that calcium mobilization is induced upon integrin-ligand contact and that calcium influx is required for cell adhesion and spreading.

Whiplash injury--are current head restraints doing their job?

It is generally accepted that the incidence of whiplash associated disorders is increasing in all industrialised countries, despite the almost universal fitment of head restraints in at least the front seats of cars. This is usually attributed to the fact that few people can be observed to follow the standard recommendations as regards head restraint positioning, that is, level with the head vertically and as close to the head as possible horizontally. This study set out to determine whether any other factors, in addition to head restraint adjustment, could be found which would influence the severity of whiplash injury. This was done by linking medical assessment of real-world accident victims with engineering assessment of the accident vehicles. A random sample of road accident victims suffering from whiplash associated disorder was studied. The vehicles they had been travelling in were examined to assess impact severity and, where possible, measurements were made of seat and head restraint adjustment with the subject sitting in the vehicle. All subjects were interviewed to assess the disability resulting from their injuries, and their progress was followed for 12 months. The results were subjected to statistical analysis to try to determine relationships between severity of injury (as measured by resultant disability) and a number of occupant- and vehicle-related factors. A significant proportion of the sample had suffered lumbar strain injury in addition to whiplash, and these were excluded from the present analysis. Frontal impact victims suffered symptoms indistinguishable from those of rear impact victims. The beneficial effects of good head restraint adjustment could not be clearly demonstrated, and some trends, especially in rear impacts, where the benefits of a well-adjusted restraint should have been very clear, indicated that larger distances from head to restraint were associated with lower disability. The paper discusses these counter-intuitive results and their implications.

The effect of selective ultrasound screening on late presenting DDH.

We examined the impact of selective ultrasound screening on late presenting Developmental Dysplasia of the Hip (DDH) in the Salford area. In the years 1991-1995, babies with suspected clinical hip instability and a number of babies with known risk factors for DDH were referred to a designated Baby Hip clinic for sonographic hip examination. The decision for treatment was based solely on ultrasound findings. We found that nineteen babies reported as having a clinically normal hip by a Senior Registrar in Orthopaedics had sonographically abnormal hips and were treated successfully with an abduction splint. The incidence of late presenting DDH was not reduced when compared with two previous cohorts born at the same centre. None of the children that presented with a late DDH was referred for a sonographic examination after birth. A more widespread ultrasound screening programme including all babies with risk factors for DDH is advised in order to reduce late presentations.

Ratio of basic surgical trainees to type 1 specialist registrar programmes 1999/2000/2001/2002.

It is recently becoming increasingly apparent that there is a significant discrepancy between the number of basic surgical trainees seeking Type 1 higher surgical training programmes and the number of those programmes available for appointment.

Removal of orthopedic implants in children: morbidity and postoperative radiologic changes.

One hundred twenty-one procedures for the removal of metalwork performed on 110 children aged 1-15 years is reported, with a focus on postoperative morbidity and radiographic skeletal changes. The removals were for a variety of acute and chronic pediatric orthopedic conditions. The level of postoperative morbidity was lower than in adult study groups with only one refracture (0.9%). Only four removals were considered to be difficult. All patients had a postoperative radiograph taken. The skeletal response to the fixation device was assessed by measuring the degree of cortical assimilation of the implant. Dynamic compression plating was compared with third tubular fixation. Overall cortical indentation was 7.3% in the third tubular group and 41.6% in the dynamic compression plating group; similar results were found in forearm fracture and hip osteotomy subgroups (P < 0.01, Wilcoxon unpaired test). The degree of indentation was related to the length of time for which the plate was left in situ. It is postulated that plates with high stress-rising characteristics are incorporated with growth and should both be removed early and have strictly limited indications for their use.