Sixty patients with congenital deformities of the spine were operated upon in the past fifteen years using a two-stage procedure. In the fifty patients with scoliosis half of the deformities were due to hemivertebrae and half to unilateral bars. The average correction of the deformity was 47 per cent. Early neurological signs observed in two patients with a diastematomyelia resolved. Of the ten patients with kyphosis nine had neurological signs of impending paraplegia and one was completely paraplegic before operation; all improved markedly. Posterior spinal fusion alone in the rapidly progressing congenital deformity may not prevent further progression, particularly in those cases iwth unilateral bars. Anterior resection of the vertebral body with later posterior fusion with Harrington instrumentation is safe and effective

This paper describes a simple method for the recording of rib deformity in idiopathic scoliosis. The relationships have been recorded between the measured rib hump and rib depression deformities and 1) the rotation of the vertebral bodies (as measured by the method of Nash and Moe on the standing radiograph); 2) the degree of lateral curvature (as measured by the method of Cobb on the standing radiograph); and 3) the rib-vertebra angles and their differences (as described by Mehta). No clear linear relationships were found. Many examples of irregular relationship were recorded, for example, marked spinal rotation with minimal rib hump. The response of the rib deformities to treatment by Milwaukee brace in fifty-two patients is described; the hump is little changed but the depression on the opposite side may be considerably reduced. Harrington instrumentation may have a similar effect

1. The results of posterior spinal fusion for paralytic scoliosis in 118 patients have been reviewed after growth had finished. The criteria for skeletal maturity were both clinical and radiological, with emphasis on ossification of the iliac apophyses. 2. The age of onset of anterior poliomyelitis and the age at which scoliosis was first noticed, as well as the extent of the muscle weakness and the curve patterns, all have a bearing on the severity of the deformity and the indication for operative treatment. 3. The method of treatment including operation is described and the complications detailed. The use of a tibial strut has now been abandoned and Harrington instrumentation has become routine. 4. There were five deaths in the series, three early and two late. 5. The difference in height, changes in respiratory function and eventual functional capacity have been analysed

From 1990 to 1993 we treated 22 consecutive patients who had progressive spinal kyphosis due to ankylosing spondylitis by a closing-wedge posterior vertebral osteotomy with partial corporectomy of L4 and transpedicular fixation. The average correction was 32 degrees (24 to 52) with a mean loss of correction after operation of 2.7 degrees (0 to 13). The average operating time was 185 minutes (135 to 240) and blood loss was 2500 ml (1200 to 5000). The osteotomy corrected all patients sufficiently to allow them to see ahead and their posture was improved. There were no fatal complications, but in two cases there was failure of the instrumentation and one patient needed reoperation for nerve compression. Two deep wound infections required removal of the implant and six patients had superficial skin infections under the plaster. The use of a circoelectric bed and intermittent prone lying eliminated this problem

A survey was conducted to document the results of bracing and spinal fusion for scoliosis associated with osteogenesis imperfecta. Observations were made of 121 patients who underwent treatment by bracing or spinal fusion and who had been treated by 51 orthopaedic surgeons in 14 countries. The average curve before bracing measured 43 degrees. The braces were ineffective in stopping progression even in small curves. We were unable to determine whether braces slowed the rate of progression of curvature. The average age at fusion was 15 years 7 months, the average curve before operation measured 74 degrees, and the average correction was 36 per cent. The high incidence of complications was related to the size of the curve before spinal fusion, the use of Harrington instrumentation, and the presence of associated kyphosis. In the absence of pseudarthrosis or kyphosis, late bending of the fused spine did not seem to occur

Aims

It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanical alignment (MA).

The factors during and after operation which influence the development of a solid and stable posterior spinal fusion have been evaluated in 406 patients with scoliosis. The patients were managed in three different ways and all pseudarthroses were accurately detected by exploring the spines six months after the attempted fusion. The incidence of pseudarthroses was significantly lowered from 25 per cent in Group I to 3.8 per cent in Group III by the application of Harrington instrumentation and the use of large amounts of autogenous iliac bone grafts in addition to an interfacetal fusion. Early mobilisation 7 to 10 days after operation and a return to normal activities in a well-moulded underarm plaster jacket did not have a detrimental effect on the development of the fusion or the early maintenance of correction. Those spines with supplementary bone grafts stabilised more rapidly and had better maintenance of correction with only minimal loss after removal of all external support at 10 months

We assessed narrowing of the spinal canal in 39 burst fractures and fracture-dislocations of thoracolumbar vertebrae treated by the AO Internal Spinal Fixator, using CT preoperatively and at various stages postoperatively. Computer-aided planimetry was used to measure the narrowing, and its restoration shortly after instrumentation, or at 15 months. The mean initial reduction of canal area was to 63.7% +/- 18.8% of normal; this was restored to a mean of 95.4% +/- 21.2% of normal when measured either soon after surgery or at 15 months (p < 0.001 for both groups). There was more improvement in cases assessed later. For fractures from D12 to L3, the mean canal area was restored to 99.4% of normal; but at L4 or L5 the mean restitution was to only 60.9% (p < 0.05). We found no correlation between preoperative loss of area and amount of restoration, or severity of neurological deficit. Nor was there any correlation between the delay before surgery and the improvement achieved. The mechanism of fracture reduction appears to be a combination of distraction ligamentotaxis and forced hyperextension

Aims

Spinal tuberculosis (TB) remains an important concern. Although spinal TB often has sequelae such as myelopathy after treatment, the predictive factors affecting such unfavourable outcomes are not yet established. We investigated the clinical manifestations and predictors of unfavourable treatment outcomes in patients with spinal TB.

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental study, loaded pedicle screw instrumentations were implanted in the sheep for six or 12 weeks. After radiological examination the pull-out resistance and the histological characteristics were studied. In the clinical study, all screws with radiolucent zones had a significantly reduced mean extraction torque compared with screws without radiolucent zones (16 ± 10 Ncm v 403 ± 220 Ncm; p < 0.0001). In the experimental study the mean maximum pull-out resistance for the screws with radiolucent zones was significantly lower than for those with no radiolucency (243 ± 156 N v 2214 ± 578 N; p = 0.0006) and the mean bone-to-screw contact was reduced for screws with zones compared with those without zones (8 ± 9% v 55 ± 29%; p = 0.0002). Our findings showed that all screws with radiolucent zones had low extraction torques or low pull-out resistance. A radiolucent zone is a good indicator of loosening of a pedicle screw

We undertook a prospective, randomised study using a non-invasive transcranial Doppler device to evaluate cranial embolisation in computer-assisted navigated total knee arthroplasty (n = 14) and compared this with a standard conventional surgical technique using intramedullary alignment guides (n = 10). All patients were selected randomly without the knowledge of the patient, anaesthetists (before the onset of the procedure) and ward staff. The operations were performed by a single surgeon at one hospital using a uniform surgical approach, instrumentation, technique and release sequence. The only variable in the two groups of patients was the use of single tracker pins of the imageless navigation system in the tibia and femur of the navigated group and intramedullary femoral and tibial alignment jigs in the non-navigated group. Acetabular Doppler signals were obtained in 14 patients in the computer-assisted group and nine (90%) in the conventional group, in whom high-intensity signals were detected in seven computer-assisted patients (50%) and in all of the non-navigated patients. In the computer-assisted group no patient had more than two detectable emboli, with a mean of 0.64 (SD 0.74). In the non-navigated group the number of emboli ranged from one to 43 and six patients had more than two detectable emboli, with a mean of 10.7 (. sd. 13.5). The difference between the two groups was highly significant using the Wilcoxon non-parametric test (p = 0.0003). Our findings show that computer-assisted total knee arthroplasty, when compared with conventional jig-based surgery, significantly reduces systemic emboli as detected by transcranial Doppler ultrasonography

We carried out an audit on the result of achieving early walking in total knee replacement after instituting a new rehabilitation protocol, and assessed its influence on the development of deep-vein thrombosis as determined by Doppler ultrasound scanning on the fifth post-operative day. Early mobilisation was defined as beginning to walk less than 24 hours after knee replacement. Between April 1997 and July 2002, 98 patients underwent a total of 125 total knee replacements. They began walking on the second post-operative day unless there was a medical contraindication. They formed a retrospective control group. A protocol which allowed patients to start walking at less than 24 hours after surgery was instituted in August 2002. Between August 2002 and November 2004, 97 patients underwent a total of 122 total knee replacements. They formed the early mobilisation group, in which data were prospectively gathered. The two groups were of similar age, gender and had similar medical comorbidities. The surgical technique and tourniquet times were similar and the same instrumentation was used in nearly all cases. All the patients received low-molecular-weight heparin thromboprophylaxis and wore compression stockings post-operatively. In the early mobilisation group 90 patients (92.8%) began walking successfully within 24 hours of their operation. The incidence of deep-vein thrombosis fell from 27.6% in the control group to 1.0% in the early mobilisation group (chi-squared test, p < 0.001). There was a difference in the incidence of risk factors for deep-vein thrombosis between the two groups. However, multiple logistic regression analysis showed that the institution of an early mobilisation protocol resulted in a 30-fold reduction in the risk of post-operative deep-vein thrombosis when we adjusted for other risk factors

Aims

The surgical treatment of tuberculosis (TB) of the spine consists of debridement and reconstruction of the anterior column. Loss of correction is the most significant challenge. Our aim was to report the outcome of single-stage posterior surgery using bone allografts in the management of this condition.

One hundred and sixty-seven patients with adolescent idiopathic scoliosis were allocated prospectively to one of three different groups for correction before undergoing posterior spinal fusion and Harrington instrumentation, In group 1 single curves were corrected by a Risser turnbuckle plaster jacket and double curves by halo-pelvic traction. In Group 2 patients performed Cotrel dynamic traction for three weeks and this was followed by correction in a plaster cast. In Group 3 patients were given Cotrel dynamic traction for one week only and the operation was performed without a plaster cast. There was no significant difference in the overall correction achieved among the patients in the three groups except that double curves corrected slightly better in Group 2. The correction achieved by Cotrel dynamic traction after three weeks was not significantly different from that obtained at 48 hours. An anteroposterior radiograph of the spine taken during Cotrel dynamic traction was a valuable guide to the mobility of the curve and is preferable to radiographs of the patients bending laterally, particularly with respect to curves over 70 degrees. The paper concludes that correction before operation is not required routinely in adolescent idiopathic curves unless the deformity is a severe and rigid one in which case a radiograph during Cotrel traction is a useful assessment

Aims

The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA).

1. Osteogenesis imperfecta is characterised by osseous fragility. Patients with the "congenita" form have multiple fractures before birth; those with the "tarda" form have osteoporosis, and develop multiple fractures and milder deformities of long bones at varying times after birth. 2. The frequency of blue sclera, dentinogenesis imperfecta, bruising, ligamentous laxity, and deafness are recorded in sixty patients seen at the Hospital for Sick Children, Toronto, from 1949 to 1969. The major orthopaedic deformities of long bones were antero-lateral bowing of femur and anterior bowing (sabre shin) of tibia. 3. The incidence of scoliosis (40 per cent) is high in osteogenesis imperfecta. Two patients, one in Toronto and one in Seattle, have had Harrington instrumentation and fusion for this. 4. Fractures were commonest in the femur and tibia and few in the cervical spine and femoral neck. There were four cases of disturbing hyperplastic callus formation. 5. Twenty-one patients were operated on for long bone deformities and recurrent fractures by the Sofield technique. Despite extensive subperiosteal dissection non-union is rare (four cases). Fourteen of twenty-one patients so treated are able to walk, with or without assistance. Surgical intervention to both correct and prevent deformities is justified. 6. Patients with osteogenesis imperfecta compensated for their disability by reasonable academic achievement and by choosing a sedentary occupation

Objectives

The use of the haptically bounded saw blades in robotic-assisted total knee arthroplasty (RTKA) can potentially help to limit surrounding soft-tissue injuries. However, there are limited data characterizing these injuries for cruciate-retaining (CR) TKA with the use of this technique. The objective of this cadaver study was to compare the extent of soft-tissue damage sustained through a robotic-assisted, haptically guided TKA (RATKA) versus a manual TKA (MTKA) approach.