We studied the aetiology of vertebral slip in a long-term follow-up of 22 adult patients with isthmic spondylolysis or spondylolisthesis of L5. Of the 18 with spondylolysis without slip, 13 showed no slip after ten years, but five developed displacement of over 5%. All four patients with spondylolisthesis showed progression of the slip. We found that the vertical thickness of the transverse process of L5 was significantly greater (p < 0.01) in the 13 patients with no slip than in the other two groups. The relationship of vertebral slip to the shape of the transverse processes of L5 may be explained by differences in the bulk or physiological strength of the posterior bands of the iliolumbar ligament

Spines are often stabilised posteriorly by internal fixation and anteriorly by a bone graft. The effect of an autologous bone graft from the iliac crest on implant loads is unknown. We used an internal spinal fixation device with telemetry to measure implant loads for several body positions and activities in nine patients before and after anterior interbody fusion. With the body upright, implant loads were often higher after than before fusion using a bone graft. Distraction of the bridged region led to high implant loads in patients with a fractured vertebra and to marked changes in load in those with degenerative instability. Leaving the lower of the bridged intervertebral discs intact led to only small changes in fixator load after anterior interbody fusion. A bone graft alone does not guarantee a reduction of implant loads

Anteriorly displaced fractures of the wrist can be treated by the Kapandji technique of percutaneous intrafocal pinning with pins inserted through an anterior approach to give good reduction and stabilisation of the fracture. We have modified this technique by placing the pins through a posterior approach which decreases the risks of neurovascular damage. We have used this method to treat six children with distal radial fractures showing anterior displacement or instability. Good anterior stabilisation was achieved. The pins were removed at an average of eight weeks and the patients were then able to return to full activity. This simple technique can be used for unstable fractures after the failure of conservative treatment or in bilateral fractures in adolescents

Five patients with classical Ehlers-Danlos syndrome developed severe spinal deformities. Two were shown to have type-VI collagen abnormalities. Three had a double structural scoliosis of the thoracic and lumbar regions, one had a single thoracic scoliosis and one had a thoracic kyphosis. The curves first developed before the age of four years, and were not controlled by bracing. Major corrective surgery with posterior fusion was performed at a mean age of 11 years 8 months. Excessive blood loss could be controlled and although wound haematoma and dehiscence were common, they did not provide major problems. The spinal fusions healed satisfactorily

We treated 183 patients with fractures of the odontoid process (109 type II, 74 type III) non-operatively. Union was achieved in 59 (54%) with type-II fractures. All type-III fractures united, but in 16 patients union was delayed. There was no correlation between union and the clinical or radiological outcome of the fractures. Selective vertebral angiography, carried out in 18 patients ten with acute fractures and eight with nonunion, showed that the blood supply to the odontoid process was not disrupted. Studies on ten adult axis vertebrae at post-mortem showed that the difference in the surface area between type-II and type-III fractures was statistically significant. Our findings show that an age of more than 40 years, anterior displacement of more than 4 mm, posterior displacement and late presentation contribute towards nonunion of type-II fractures

Premature fusion of the triradiate cartilage was obtained surgically in 10 three-week-old rabbits, and compared with isolated fusion of the ilio-ischial and of the ilio-pubic limbs of the triradiate cartilage in two further groups of 10 rabbits. Complete fusion caused acetabular dysplasia five weeks after operation in all animals and hip dislocation at nine weeks in half of them; ilio-ischial fusion had a comparable effect. Ilio-pubic fusion had only a minimal effect on acetabular development. The posterior position of the ilio-ischial limb in the acetabulum and its predominance in the formation of the triradiate cartilage in quadrupeds may have contributed to its decisive effect on acetabular development

Dorsiflexion has been studied in three normal feet and in three feet with talipes equinovarus to determine the anatomical features which might contribute to the failure of operative treatment to correct the deformity. In the normal feet the movement of dorsiflexion was found to be essentially rotatory in nature and not simply hinging; as dorsiflexion proceeds the fibula moves forwards relative to the os calcis and the calcaneal tendon. In the club feet a posterolateral tether was found; this prevented fibular movement and blocked dorsiflexion. As a result of this study a posterior and lateral release is advocated for the operative correction of the hindfoot in a child with a club foot deformity, particularly under the age of a year

Aims

Our aim in this study was to describe the long-term survival of the native hip joint after open reduction and internal fixation of a displaced fracture of the acetabulum. We also present long-term clinical outcomes and risk factors associated with a poor outcome.

A study of spondylolysis and spondylolisthesis in 142 children and adolescents is reported. In twelve of the seventy-nine patients followed for over a year the affected vertebra slipped further by 10 per cent or more. Increasing slip occurred mainly during the adolescent growth spurt, and was greater when spinal bifida or other vertebral anomalies were present. If at presentation the slip is less than 30 per cent then further slip beyond 30 per cent is unlikely. Decompression posteriorly is advised when signs of nerve pressure are present. Indications for spinal fusion are suggested; the intertransverse method of fusion was used in sixty-nine patients

This paper describes seven patients who developed late vertebral deformity after flexion injuries of the cervical spine. In four the clinical and radiological features were subtle and because the patients walked into an emergency department the severity of the injury was not initially appreciated. Certain specific clinical and radiological features of flexion injury are described and emphasis is placed on the importance of correct management. A radiological tetrad is described which should alert the surgeon to the possibility of damage to the posterior interspinous complex of the cervical spine and so lead to further radiological investigations. Despite the frequency of flexion injuries the alarming complications described in this paper are rare

1 . Funnel chest deformity is a common cause of progressive postural defects in children. 2. The underlying pathology of the funnel chest is a congenital deficiency of the muscle fibres of the anterior part of the diaphragm which allows the stronger posterior element to pull backwards the xiphoid and sternum. The postural changes are secondary to the chest deformity. 3. Operative correction of the chest deformity is described. 4. Post-operative physiotherapy is essential to correct the postural deformities. Patients must remain under orthopaedic supervision to maintain the correction obtained. 5. A series of twelve children treated by operation is reported, with excellent results in all

Objectives

Pulsed electromagnetic field (PEMF) stimulation was evaluated after anterior cervical discectomy and fusion (ACDF) procedures in a randomized, controlled clinical study performed for United States Food and Drug Administration (FDA) approval. PEMF significantly increased fusion rates at six months, but 12-month fusion outcomes for subjects at elevated risk for pseudoarthrosis were not thoroughly reported. The objective of the current study was to evaluate the effect of PEMF treatment on subjects at increased risk for pseudoarthrosis after ACDF procedures.

Techniques for the selective cutting of ligaments in cadaver knees defined the static contributions of the posterolateral structures to external rotation, varus rotation and posterior tibial translation from 0° to 120° of flexion under defined loading conditions. Sectioning of the popliteofibular ligament (PFL) (group 1) produced no significant changes in the limits of the knee movement studied. Sectioning of the PFL and the popliteus tendon (femoral attachment, group 2) produced an increase of only 5° to 6° in external rotation from flexion of 30° to 120° (p < 0.001). Even when other ligaments were sectioned first (group 3), the maximum effect of the PFL was negligible. Our findings show that the popliteus muscle-tendon-ligament complex, lateral collateral ligament, and posterolateral capsular structures function as a unit. No individual structure alone is the primary restraint for the movements studied. Operative reconstruction should address all of the posterolateral structures, since restoration of only a portion may result in residual instability

We report the preliminary findings of the use of roentgen stereophotogrammetric analysis to evaluate the early migration of five femoral components after revision for mechanical loosening using impacted cancellous allograft and cement. All hips were examined at one week, four to six months and one year after surgery. All the components subsided by 0.4 to 4.9 mm during the first year. In four hips the prosthetic head was displaced 1.1 to 6.9 mm posteriorly. Fixation of the femoral components was less secure than after primary arthroplasty but the incidence and magnitude of early migration were similar to those after revision with cement alone

We have studied 29 patients for at least five years after canal-expansive laminoplasty for cervical spondylotic myelopathy. The short- and long-term clinical results were compared, and successive radiographs assessed. The long-term clinical outcome was excellent in five patients, good in 12, fair in 11 and poor in one. The mean short- and long-term improvements were 54.4% and 48.5% but patients with focal kyphotic, kyphotic and S-shaped cervical spines did less well, as did those who had a decrease in the index of curvature of the cervical spine of more than 10 at follow-up. Canal-expansive laminoplasty with reconstitution of the posterior soft tissues may help to prevent postoperative malalignment and late neurological deterioration

Intraoperative pulmonary fat and bone-marrow embolism is a serious complication of bone and joint surgery. We have investigated the occurrence and incidence of intraoperative embolism in patients undergoing elective lumbar spinal surgery with or without instrumentation. Sixty adult patients with lumbar degenerative disease were examined by intraoperative transoesophageal echocardiography while undergoing posterior lumbar surgery. Of these, 40 underwent surgery with instrumentation and 20 without. Moderate to severe (grade 2 or 3 according to the grading scale of Pitto et al) embolic events were seen in 80% of the instrumented patients but in none of the non-instrumented patients (p < 0.001). The insertion of pedicle screws was particularly associated with large numbers of pulmonary emboli, while the surgical approach, laminectomy, disc removal and bone harvesting were associated with small numbers of emboli. We consider that, as in arthroplasty and intramedullary fixation of fractures, these embolic events are relevant to the development of potentially fatal fat embolism during spinal surgery

A controlled study, comparing computer- and conventional jig-assisted total knee replacement in six cadavers is presented. In order to provide a quantitative assessment of the alignment of the replacements, a CT-based technique which measures seven parameters of alignment has been devised and used. In this a multi-slice CT machine scanned in 2.5 mm slices from the acetabular roof to the dome of the talus with the subject’s legs held in a standard position. The mechanical and anatomical axes were identified, from three-dimensional landmarks, in both anteroposterior and lateral planes. The coronal and sagittal alignment of the prosthesis was then measured against the axes. The rotation of the femoral component was measured relative to the transepicondylar axis. The rotation of the tibial component was measured with reference to the posterior tibial condyles and the tibial tuberosity. Coupled femorotibial rotational alignment was assessed by superimposition of the femoral and tibial axial images. The radiation dose was 2.7 mSV. The computer-assisted total knee replacements showed better alignment in rotation and flexion of the femoral component, the posterior slope of the tibial component and in the matching of the femoral and tibial components in rotation. Differences were statistically significant and of a magnitude that support extension of computer assistance to the clinical situation

Computerised arthrotomography was performed on 33 patients four to six weeks after acute primary anterior dislocation of the shoulder. Seventeen patients were under, and 16 over 50 years of age. Damage to the anterior glenoidal labrum was seen in all the younger patients and in 75% of the older ones. A large redundant capsular pouch, seen in the older patients, was present in 35% of the younger ones, and a posterior humeral head defect was seen in 82% of the younger patients and only 50% of the older. Associated fractures were more common in the older patients, and a tear of the rotator cuff was demonstrated in 63% of the older patients and in none of the younger ones

Reports of spondylolysis in vertebrae other than those of the lower lumbar spine are rare. We report 32 patients with upper lumbar spondylolysis who have been studied clinically, radiologically and scintigraphically. Twenty patients had bilateral lesions, and seven of those with unilateral lesions had structural changes or anomalies in the opposite posterior arch. Positive scans were found to be associated with a short clinical history, and indicated stress-related lesions. Our findings suggest that mechanical factors may play a role in the aetiology of spondylolysis in the upper lumbar spine similar to that which they play in the lower lumbar spine, and that local structural anomalies may contribute to abnormal loading of these vertebrae