We report a prospective study of 55 patients with acute primary patellar dislocation, all treated by operation and followed up for at least two years. Diagnosis was based on the history of a lateral displacement, with medial tenderness and a positive apprehension test; redislocations were excluded. Before operation, the difference in lateral shift on skyline views of the injured and control patellae was highly significant. At operation, rupture of the medial retinaculum of the patella was seen in all but one case. There were medial marginal fractures of the patella in 23 cases. Subjective results of the operation were excellent or good in 44 of the 55 at two years with a redislocation rate of only 9%. Most patients were able to return to the same level of sporting activity as before the injury.

We investigated a new intramedullary locking nail that allows the distal interlocking screws to be locked to the nail. We compared fixation using this new implant with fixation using either a conventional nail or a locking plate in a laboratory simulation of an osteoporotic fracture of the distal femur. A total of 15 human cadaver femora were used to simulate an AO 33-A3 fracture pattern. Paired specimens compared fixation using either a locking or non-locking retrograde nail, and using either a locking retrograde nail or a locking plate. The constructs underwent cyclical loading to simulate single-leg stance up to 125 000 cycles. Axial and torsional stiffness and displacement, cycles to failure and modes of failure were recorded for each specimen. When compared with locking plate constructs, locking nail constructs had significantly longer mean fatigue life (75 800 cycles (sd 33 900) vs 12 800 cycles (sd 6100); p = 0.007) and mean axial stiffness (220 N/mm (sd 80) vs 70 N/mm (sd 18); p = 0.005), but lower mean torsional stiffness (2.5 Nm/° (sd 0.9) vs 5.1 Nm/° (sd 1.5); p = 0.008). In addition, in the nail group the mode of failure was either cut-out of the distal screws or breakage of nails, and in the locking plate group breakage of the plate was always the mode of failure. Locking nail constructs had significantly longer mean fatigue life than non-locking nail constructs (78 900 cycles (sd 25 600) vs 52 400 cycles (sd 22 500); p = 0.04).

The new locking retrograde femoral nail showed better stiffness and fatigue life than locking plates, and superior fatigue life to non-locking nails, which may be advantageous in elderly patients.

Cite this article: Bone Joint J 2014;96-B:114–21.

We present the results of 38 children with leg inequality treated by circumferential periosteal release. Leg-length discrepancy was expressed as a percentage of the longer limb. All patients showed a decrease in percentage difference at one year after operation, the mean difference dropping from 7.24% to 5.45%. The size of the response was directly related to the age of the patient at operation, being more pronounced in the younger patients. The response was not related to sex, diagnosis, or rate of growth of the patient immediately preceding operation.

The technique and results of microsurgical techniques for lumbar disc protrusions in 60 patients are presented. All patients were followed up for a minimum of 2.5 years, and 91% had good or excellent results. The only patient with a recurrent disc sequestration had a good result after a second operation.

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.

Five cases of congenital pseudarthrosis of the tibia successfully treated by a free vascularised fibular graft are described. Follow-up ranged from 5 to 34 months with a mean of 17.5 months. The technique, which includes radical excision of abnormal bone and soft tissue around the pseudarthrosis, also permits primary bone lengthening, and correction of deformity. The early results indicate that satisfactory bony union is achieved in a relatively short period of time.

The development of the iron-cored electromagnet as a stimulator of bony union is described. In a clinical trial extending over eight years, 80 patients were treated for various forms of failed union. Their results are presented, as well as tentative conclusions regarding the indications and efficiency of the method. The latest, fully-portable apparatus is described.

A simple technique for screw fixation of the carpal scaphoid in cases of delayed union and non-union is described. The results obtained in 32 patients treated by this method are reported. The average follow-up was three years ranging from 10 months to 12 years. Union was obtained in 28 patients. The causes of failure to unite are discussed and the advantages of the reported method over other techniques such as bone grafting are stressed.

Fifty-three ununited fractures with a median time since injury of 28 months were treated by electrical stimulation using pulsing electromagnetic fields. Union was achieved in 38 cases (71.7 per cent) in a median time of six months. For ununited fractures of the tibia the success rate was higher at 86.7 per cent. Previous or active sepsis, the presence of plates or nails, the age of the patient or the time since the injury did not affect the results. Analysis of the failures suggests that inadequate immobilisation, a fracture gap of more than five millimetres or the presence of a screw in the fracture gap was responsible. In four patients no cause of failure could be determined.

The off-loading characteristics of the cast-braces of 30 patients with fractures of the shaft of the femur have been investigated, during axial loading, using strain-gauge transducers. These were applied at the level of the fracture, where the cast was circumferentially split, and to the hinges of the brace at the knee. They measured the load transferred between the two portions of the thigh cast, and between the thigh cast as a whole and the below-knee cast; by subtraction from the total load on the limb, the skeletal force at the fracture level and at the knee could be calculated. In all patients there was an increase in the fracture load as union progressed which was thought to be due to physiological feedback mechanism from the fracture site. The load carried by the two portions of the thigh cast and by the thigh cast as a whole was proportionately high at first and stabilised at an average of 35 per cent of body weight.

A non-invasive method of electrical stimulation of healing in ununited fractures of the tibia by pulsed magnetic fileds has been evaluated. In a series of 17 patients all but two of the fractures united within 4 to 10 months, with an average time of just under six months. The method is sufficiently promising to merit further clinical investigation.

Chronic instability of the ankle is frequently due to disruption of the fibres of the anterior talofibular ligament and the anterolateral capsule. This allows momentary subluxations at the ankle joint; the talus tilts into an abnormal varus position and rotates forwards and inwards about a vertical axis which passes through the medial malleolus. The use of a free tendon graft to reconstruct the anterior talofibular ligament restores the stability of the ankle without restricting movement at the subtalar level.

Children with flail feet who have control of their hips and knees are able to walk but are unable to stand still and find it difficult to walk slowly. These problems have been overcome in fifty-three children with flail feet due to myelomeningocele by fitting them with below-knee orthoses which provide maximum stability and yet allow normal walking. The biomechanical principles and the development of the orthoses are discussed.

1. Early recognition of femoro-pelvic instability in proximal femoral dysplasia is essential to rational management.

2. Certain radiological signs helpful in identifying such patients within the first year are described.

3. Early operation is recommended to prevent displacement of a pseudarthrosis and to encourage healing. Alternative methods are described for established defects.

4. Radiological signs are described which indicate that healing without loss of femoro-pelvic stability will occur. Such patients may be managed expectantly.

1. Attention is drawn to the progressive disability caused by irreparable defects of the ulna in growing children.

2. Cross-union between the radius and the ulna resolves some of these problems and contributes greater stability and power to the hand.

1. Thirty-four cases of calcaneal osteotomy for mobile flat foot in nineteen patients are reviewed.

2. The function was markedly improved in seventeen of the nineteen patients.

3. The operation was successful in correcting the valgus deformity of the heel in thirty of the thirty-four feet. it was less successful in improving the longitudinal arch, especially when the flat foot deformity was severe.