1. A relatively simple method of occipito-cervical fusion using autogenous bone chips without internal fixation is described. 2. In patients with atlanto-axial subluxation posterior fusion from the occiput to the axis rather than from the atlas to the axis is more reliable and is preferred. Inclusion of the occiput adds no more than a few degrees to the restriction of movement that follows C. 1-2 fusion. 3. The indications for occipito-cervical fusion are discussed, particularly in relation to C. 1-2 instability in rheumatoid arthritis

We report nine cases of irreducible congenital dislocation of the knee which were treated by early operation with good results. All were resistant to conservative measures and operation was performed at an average age of nine months. The essential abnormality was a short quadriceps muscle together with subluxation of the hamstring muscles to lie anterior to the axis of knee flexion. The quadriceps tendon was lengthened by VY-plasty and in six cases additional length was gained by proximal mobilisation of the muscle. After operation all the patients were able to walk

The following preliminary conclusions seem possible. 1. In early cases of Pott's disease of the thoracic spine in children the treatment should include chemotherapy, recumbency and costo-transversectomy. An exception may be made if severe destruction has led to subluxation of the column, when more radical surgery is indicated. 2. Combination of conservative treatment with costo-transversectomy can prevent spread of the disease along the vertebral column, and can lead to regression of this "spondylitis anterior.". 3. The abscess can be totally eradicated and the risk of recrudescence therefore diminished

Ten normal neonatal hips were examined in stillborn babies. At first, forcible Barlow manoeuvres did not produce subluxation or dislocation, but by repeated examination a previously stable joint could be rendered unstable. Dissection of the hips showed that the vacuum fit between the femur and the acetabulum was an important factor in neonatal hip stability. The posterior capsule was not a strong or, in itself, an important structure. It is postulated that the capsule and the labrum act together as 'O' rings to maintain the vacuum fit; it is possible that repeated examinations, by producing an effusion, could break the seal and allow instability

Five children with atlanto-axial rotatory fixation (AARF) in association with fractures of the clavicle are described. It is postulated that the rotary fixation is a direct result of the trauma which produces the fracture. The importance of early diagnosis is stressed, since delayed diagnosis may lead to chronic deformity. Early diagnosis depends on awareness of the possibility of AARF, and either fluoroscoping the patient in order to take appropriate spot films or imaging the atlanto-axial joint by CT. A simple classification of AARF is proposed based on distinct radiological features which differentiate subluxation from dislocation

A logical, objective and reproducible grading system for the pivot shift test is proposed. The rationale is based on performing the examination in varying positions of rotation of the tibia, allowing the type and degree of the different laxities to be defined and quantified. The system has been assessed against a new "unblocked" test for anterior subluxation and against radiographic measurements, operative findings and results. This grading system can be valuable in pre-operative assessment and planning and its use in postoperative evaluation would enable results from different centres and different procedures to be compared more accurately

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

1. One hundred and twenty-six metacarpo-phalangeal joints affected by rheumatoid arthritis were studied macroscopically at either synovectomy or arthroplasty. 2. The sites and extent of the initial erosion corresponded with the sites and size of the synovial pouches. 3. The areas of cartilage degeneration were related to the degree of flexion, ulnar deviation and subluxation of the proximal phalanx on the metacarpal head. 4. The routine radiographic findings were not a true reflection of all the pathological changes within the joint. 5. It is suggested that by encouraging joint movement and preventing deformity the degree of cartilage degeneration may be diminished

A simple method of measuring the degree of acetabular development in the radiograph of the adult pelvis is described and arguments for its validity are advanced. This measurement is referred to as the acetabular angle. The normal values for this angle are between 33 and 38 degrees. Angles below 32 degrees are uncommon and probably of no clinical significance, whereas angles from 39 to 42 degrees are in the upper limit of normality. An angle of 47 degrees is shown in a hip with congenital subluxation. The prognosis for hip joints with acetabular angles between 42 and 47 degrees is under investigation

Aims

The primary aim of this study was to address the hypothesis that fracture morphology might be more important than posterior malleolar fragment size in rotational type posterior malleolar ankle fractures (PMAFs). The secondary aim was to identify clinically important predictors of outcome for each respective PMAF-type, to challenge the current dogma that surgical decision-making should be based on fragment size.

Aims

Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology.

Until recently the accepted treatment of choice for severe type-II fibular hemimelia has been Syme’s or Boyd’s amputation. The alternative of distraction lengthening using the Ilizarov technique is now available. We report three patients (four limbs) with type-II fibular hemimelia who were treated by the Ilizarov technique and followed up for two to six years. Severe progressive procurvatum and valgus deformity of the tibia and valgus deformity and lateral subluxation of the ankle were found in all four limbs. Multiple additional soft-tissue and bony surgery was necessary. In view of these problems we feel that reappraisal of the indications for lengthening in type-II fibular hemimelia is necessary

The patterns of laxity of normal wrists subjected to dorsal and volar stresses were analysed. Dorsal and volar displacement tests were carried out on both wrists of 50 subjects under image-intensifier control. Lateral projections in neutral, and dorsal and volar stress positions were taken to analyse the behaviour of the carpal bones. Varying degrees of capitolunate subluxation under dorsal and volar stress were noted. Dorsal displacement of the capitate appeared to be more prominent than volar displacement. The lunate either extended or subluxed dorsally in response to a dorsal stress, suggesting a different pattern of laxity for the radiolunate joint. These observations provide a baseline for the interpretation of dorsal and volar stress views in the symptomatic wrist

Whilst a few studies have associated various symptoms with the presence of a peroneus quartus muscle in the peroneal compartment of the leg, little is known of the clinical relevance of this muscle. We dissected 102 cadaver legs and reviewed the magnetic resonance images of 80 patients with symptoms from the ankle. The peroneus quartus, with a number of different attachments, was present in 6.6% of the legs. It most commonly arose from the peroneus brevis muscle and inserted into the retrotrochlear eminence of the calcaneum. Associated pathology included a longitudinal tear in the tendon of peroneus brevis, possible peroneal tendon subluxation or dislocation, and a prominent retrotrochlear eminence. On the MR scans its presence was associated with pain and weakness of the ankle. Orthopaedic surgeons and radiologists should be aware of the possible presence of the peroneus quartus muscle, not only because of possible associated pathology, but also for its potential use for surgical reconstruction

The anteroposterior stability of cadaveric knees was investigated. There was a wide range of normal laxity; knees were more stable at 90 degrees than at 20 degrees flexion. Anterior cruciate ligament implants with different stiffnesses were inserted; normal stability could always be restored, and the stiffness or extensibility of implants did not affect knee behaviour significantly. The tightness of implants was critical--small tensioning errors caused subluxation, inhibited knee extension and allowed damagingly high implant tensions. It is concluded that the tension of ligament implants could not be adjusted simply with a pre-set instrument; the procedure will remain critically dependent on the judgment of the operating surgeon

We reviewed 41 knees after arthroscopic lateral release for recurrent dislocation of the patella at a mean follow-up of four years, and graded the results according to the criteria of Crosby and Insall (1976). There were no dislocations after operation in 28 knees (68%); the less satisfactory results were in patients with subluxation of the patella on extension of the knee and those with generalised ligamentous laxity. There were no complications. A characteristic and previously unreported lesion of the patellar surface was seen in eight of the 41 knees. The results of lateral release are better than those reported for other techniques. This treatment, by either open or arthroscopic methods, is recommended

The results of excision of the distal ulna in 34 wrists of 25 patients with chronic rheumatoid arthritis of the distal radio-ulnar joint were reviewed. Rest pain had been cured or relieved in 77%, pain on pronation-supination in 86%, and limitation of pronation-supination in 90%, while 88% of the patients graded the result as excellent or fair. Despite this marked relief of symptoms, function of the upper limb was improved in only 25% of patients and remained unchanged in 60%. Ulnar subluxation of the carpus had occurred in 24% but seemed to be related to the destructive disease process rather than to the operation itself. The length of ulna resected was not related to the outcome of the operation

A simple procedure of using a Smillie knife to release the lateral patellar retinaculum and the capsule in the unstable patella syndrome is described. The syndrome includes recurrent dislocation, recurrent subluxation and acute dislocation of the patella. Arthroscopy, to exclude any other pathology such as chondromalacia patellae, is performed before proceeding to closed lateral release. The results of this procedure are as good as those after more major surgical procedures. In a small percentage of patients a second operation such as tibial tubercle transfer or patellectomy may be necessary, especially in patients with an underlying congenital abnormality; but in many patients this type of major surgery has proved unnecessary