Aims

The material and design of knee components can have a considerable effect on the contact characteristics of the tibial post. This study aimed to analyze the stress distribution on the tibial post when using different grades of polyethylene for the tibial inserts. In addition, the contact properties of fixed-bearing and mobile-bearing inserts were evaluated.

Aims

To compare radiographic failure and re-operation rates of anatomical coracoclavicular (CC) ligament reconstructional techniques with non-anatomical techniques after chronic high grade acromioclavicular (AC) joint injuries.

We have reviewed 80 children who were involved in the Medical Research Council (UK) trial of surgical treatment for tuberculosis of the spine in Hong Kong. Radical surgery or debridement had been performed at mean ages of 7.6 years (n = 47) and 5.1 years (n = 33) respectively. The patients were followed up to skeletal maturity (mean 17 years). Spinal deformity was measured on lateral radiographs taken preoperatively, at six months, one year, five years and at final follow-up. Radical surgery and grafting produced a reduction in kyphos and deformity angles at six months; this correction was maintained during the growth period. By contrast, after debridement surgery there was an increase in deformity at six months, with a tendency to some spontaneous correction during the growth period. There were statistically significant differences between angles for the radical and debridement groups only at six months postoperatively, but the changes during later follow-up were similar in the radical and debridement groups. Our findings highlight the importance of the surgical correction of deformity, and provide no evidence to suggest that disproportionate posterior spinal growth contributes to progression of deformity after anterior spinal fusion in children.

We report the results of a new surgical procedure for spastic equinovarus deformity due to cerebral palsy. This is the transfer of the anterior half of the split tibialis posterior to the dorsum of the foot through the interosseous membrane. We performed the operation on 23 feet in 18 children. All patients were assessed before operation and at follow-up at a mean of 8.4 years postoperatively. Using the criteria of Kling et al (1985), excellent results were obtained in 14 feet, good results in eight, and a poor result in only one.

Of 37 consecutive patients suffering from tuberculosis of the lumbosacral spine, 26 were reviewed after an average follow-up of 20 years. Those presenting at under 10 years of age usually had a discharging sinus or a pointing abscess and a visible kyphosis. In older patients, low back pain was the predominant presenting symptom. Neurological involvement was uncommon. Both operative and conservative treatment had resulted in fusion but all patients treated conservatively ended up with a kyphosis associated with trunk shortening. They had a higher incidence of back pain and more complications in pregnancy. Anterior debridement and fusion with a strut graft can reduce the incidence and size of kyphosis, but is technically demanding. Treatment remains difficult and requires individual consideration.

We reviewed and radiographed 30 skeletally-mature patients after isolated closed femoral shaft fractures in childhood which had been treated conservatively. When the fracture had occurred between the ages of 7 and 13 years, the limb overgrew about 1 cm regardless of sex, upper limb dominance, age, fracture site or configuration. Excessive fracture overlap at the time of injury, but not at union, increased limb overgrowth. Angulation of the fracture remodelled in children injured under 10 years of age, but in older patients this sometimes added to limb shortening. Rotational deformities were minor and gave no symptoms. Treatment of the 7- to 13-year-old patient should aim at 1 cm overlap at union, with correction of angular deformity being more important in children over 10 years of age. This management of fractures will give a maximum leg length discrepancy of 1 cm at skeletal maturity.

Twenty-two patients with late onset Pott's paraplegia presenting at a mean of 18 years after initial symptoms were reviewed an average of seven years after treatment by anterior decompression and fusion. Fourteen patients had active disease, and in 12 of these, activity at the internal kyphus was the direct cause of the paraplegia. In the other two, a soft healing bony ridge was the cause. The eight patients with healed disease had hard bony ridges compressing the cord. The response to anterior decompression was faster, better and safer in patients with active disease: nine recovered completely and three significantly. In patients with healed disease, the anterior decompression was technically more difficult and the recovery less satisfactory. Significant complications included two cases with neurological deterioration, two with cerebrospinal fluid fistulae and four with neurapraxia of the cord.

A retrospective study was made of the results of surgical treatment of subluxation or dislocation of the hip in patients who had suffered from poliomyelitis. Good results were achieved in 46% and satisfactory results in 24%. The key factors for success are muscle balance, the femoral neck-shaft and anteversion angles, and the acetabular geometry. Iliopsoas transfer can augment the hip abductor power by an average of one MRC grade. Varus derotation femoral osteotomy is important to re-establish a normal neck-shaft angle and anteversion. The results of pelvic osteotomy are variable and the importance of a posterior acetabular defect is emphasised.

A new technique is described for extra-articular subtalar arthrodesis; it combines the main elements of the Batchelor and the Grice procedures. Results were reviewed after a minimum of three years. Of the 25 feet treated 24 had solid fusion and had maintained the operative correction of the valgus deformity; the one non-union was due to deep infection.

Talectomy was performed on 10 patients (15 feet) for club foot deformity in arthrogryposis multiplex congenita. These were reviewed after an average follow-up of eight years. At follow-up nine feet were plantigrade, and six had less than 15 degrees residual equinus at the ankle. All the feet were asymptomatic but had mild residual adduction of the forefoot and marked stiffness of the hindfoot. Seven feet developed spontaneous bony ankylosis in the tibiotarsal joint. The common technical errors were incomplete removal of the talus and incorrect positioning of the calcaneus in the ankle mortise.

Thirteen patients with dystrophic spinal deformities from neurofibromatosis treated by anterior and posterior fusion have been reviewed. The shortest follow-up was five years, the average seven years. Combined fusion produced satisfactory results in patients with a smooth kyphoscoliosis or with scoliosis without kyphosis, but it was unsatisfactory in patients with an angular kyphoscoliosis. Of the five patients with angular kyphoscoliosis, one had a persistent pseudarthrosis after operation and all had progression of the kyphosis despite the treatment. The morbidity rate also was high in this group of patients. Many of the complications were related to soft-tissue manifestations of the disease. It is recommended that very special attention be paid to the dystrophic angular deformity in neurofibromatosis; even anterior and posterior spinal fusion may fail to control its progression.

The results of 10 patients with severe rigid drop-foot corrected by the Lambrinudi triple arthrodesis were studied. The average amount of correction was 47 degrees, as evaluated from standing radiographs taken before and after operation. Radiological features of osteoarthritis and of flattening of the talus were common, but the feet were painless when reviewed at an average of 70 months later. A satisfactory range of movement was obtained at the ankle joint.

Forty patients with tuberculosis of the lower cervical spine (second to seventh cervical vertebrae) have been reviewed. Pain and stiffness were important and dominant symptoms. Two types of disease were recognised. In children under 10 years old involvement was extensive and diffuse with the formation of large abscesses. In patients over 10 the disease was localised and produced less pus, but was associated with a much higher incidence of Pott's paraplegia. The overall incidence of cord compression was 42.5 per cent (17 out of 40); 13 of the 16 patients with the "adult" type of disease had this complication. The commonest method of treatment was with antituberculous drugs, anterior excision of diseased bone and grafting. This regime rapidly relieved pain, compressive respiratory symptoms due to abscesses and Pott's paraplegia. It also corrected kyphotic deformities from an average of 25.5 degrees to 5.4 degrees.

The development of lateral tibial torsion in the paralysed lower limb is well documented, but its pathogenesis is poorly understood. This paper attempts to provide an explanation for its development when it is associated with a varus or equinovarus deformity of the hindfoot. Correction of the lateral tibial torsion by supramalleolar derotation tibial osteotomy and reorientation of the ankle mortise appear to unlock the talus from the laterally rotated position, correcting a mobile hindfoot varus deformity and altering soft-tissue tensions about the ankle so that the correction achieved is maintained. In the presence of a fixed hindfoot deformity, supramalleolar derotation tibial osteotomy is useful as a first-stage procedure before corrective osteotomies of the foot. The operation described is technically simple and carries a low morbidity. Twenty supramalleolar derotation tibial osteotomies in 18 patients have been performed with satisfactory results and few complications.

Twenty-eight patients with adolescent idiopathic scoliosis treated by anterior spinal fusion with Dwyer instrumentation were reviewed. The average length of follow-up was 6.9 years. This technique produced better correction of lateral curvature and rotation than Harrington instrumentation, particularly in the thoracolumbar and lumbar region. The length of spine requiring fusion was also shorter. There is, however, a tendency for Dwyer instrumentation to lead to kyphosis. Morbidity was significant and included one case of paraplegia, four cases of deep infection and one case of instrument failure. All of these complications, except one case of deep infection, occurred in patients with curves with an apex above the seventh thoracic vertebra.

This retrospective study assesses the complications affecting the cervical spine after halo-pelvic traction in 83 patients who were followed up for a minimum of five years. Forty-four patients (53 per cent) had significant cervical complications such as radiological degenerative changes, avascular necrosis of the dens, loss of movement, pain or spontaneous fusion. The most important predisposing factors were a long period in the halo-pelvic apparatus, tuberculous kyphosis, stiffness of the spinal deformity and an age of 15 years or more at the time of application.