1. The hypothesis is advanced that the fundamental lesion of epiphysiolysis is a slow posterior growth migration of the head on the neck. 2. It is suggested that this is unrelated to the erect posture or to any abnormality of the growth cartilage. 3. Sitting stresses are measured and are postulated as the likely cause of the growth deviation. 4. The result of the deviation is an increase in the shear stress component; in the erect posture clinical epiphysiolysis is regarded as a simple fracture occurring in a proportion of deviated cases when the increased shear component exceeds the critical level appropriate to the individual. 5. It is suggested that this hypothesis explains the age and sex incidence, the left predominance, the reduced epiphysial angle found on the uninvolved hip and the clinical and radiological evolution of the disorder

1. A collected series of forty-seven traumatic dislocations of the hip in children is reported and reviewed in detail. 2. All were simple hip dislocations, and no child was included in whom there was any other injury to the affected joint. 3. All were posterior dislocations. 4. No anatomical predisposition was observed. 5. Significant complications occurred in fourteen children: avascular necrosis of the head of the femur in four, degenerative joint changes in three, premature epiphysial fusion in one and overgrowth of the femoral head in six. Study of the children with these complications revealed no common cause except the dislocation itself. 6. The injury responsible was often trivial. 7. The results suggest that it is harmless to bear weight four weeks after reduction

1. The belief that the cessation of spinal growth and curve progression coincides with the completion of growth in the iliac apophyses has been confirmed in a review of material from 224 cases. This applies also to paralytic curves. 2. In a high number of cases this ossification centre showed an asymmetrical development on the two sides of the pelvis. The appearance of a separate posterior centre of ossification is also common, and probably represents an advanced stage in the growth of the iliac apophysis. 3. Menarche and the growth of the apophyses of the vertebral bodies almost always occurred in advance of the iliac apophyses. They should be regarded as early signs of maturation, not reliable in the prognosis of curve progression. 4. The growth of the iliac apophysis appeared to be unaffected by poliomyelitis

A new technique of shoulder fusion is presented using a posterior approach. After removal of the articular cartilage, a Rush pin is introduced from the spine of the scapula, through the glenoid into the medullary canal of the humerus. This is supplemented by tension-band wiring from the acromion to the neck of the humerus and a muscle pedicle graft attached to the acromion. A shoulder spica is applied for four to six weeks. Four patients with injuries to the upper brachial plexus and 14 with paralysis of the upper arm due to anterior poliomyelitis have been followed for three years. One of the 18 patients developed nonunion; she had removed her own cast prematurely. This method of fixation provides high shear resistance and low axial stiffness without deforming plastically. It does not affect bone growth in young patients, is effective in patients with osteoporosis, and gives a high rate of union

Ossification of the ligamentum flavum and secondary spinal-cord compression were produced experimentally in mice by implanting bone morphogenetic protein (BMP) in the lumbar extradural space. The ligamentum flavum became hypertrophied and ossified, and protruded into the spinal canal. The thickness of the ossified ligament increased gradually with time, leading to compression and deformation of the spinal cord which showed various degrees of degeneration. Demyelination occurred in the posterior and lateral white columns and neuronal loss or chromatolysis in the grey matter. The pathological findings in the experimental animals closely resemble those found in the human disease and suggest that BMP may be a causative factor of ossification of the ligamentum flavum in man. This experimental model may be useful for the study of myelopathy caused by gradual spinal-cord compression

We investigated a new method of stress radiography of the subtalar joints using forced maximum dorsiflexion of the ankle in a supinated position. We measured transposition of the lateral process of the talus at the posterior subtalar joint in lateral views of normal amputated ankles, normal control subjects and patients with recurrent ankle sprains. The mean displacement in the control groups (n = 36) was 29.9%, significantly different from the 43.0% in patients with recurrent ankle sprains (n = 24). In the amputated specimens with intact ligaments movement was similar to that in normal subjects. Section of the calcaneofibular and the interosseous ligaments allowed much the same movement as in patients with recurrent ankle sprains. The new method is simple and useful for detecting subtalar instability

Between 1969 and 1989, we performed posterior segmental instrumentation on 38 patients with thoracic Scheuermann's kyphosis. We used a dynamic system without sublaminar fixation, and a kyphosis of 50 degrees was the main indication for surgery. The mean initial angle was 68 degrees (50 to 100) and the mean final kyphosis was 43 degrees at five-year follow-up, with a mean final loss after surgery of 3.7 degrees. Reconstruction of the vertebral bodies, vertebral wedging and the anterior-body height ratio were observed even in skeletally mature patients. There were no medical complications. There were three cases of loss of correction by more than 10 degrees and one of rod fracture with pseudarthrosis. The role of non-operative treatment is evaluated and early surgical treatment is advocated

We have developed a method of measuring anterior displacement of the calcaneus on the talus in instability of the subtalar joint and have used the technique to demonstrate anterior instability in 50 patients (72 feet) showing a positive drawer sign. The angle of the posterior facet of the talus was also measured to assess the bony configuration. Our patients with subtalar joint instability could be divided into three categories. The first group had a history of trauma leading to ankle instability (26 cases), the second showed generalised joint laxity (10 cases) and the third were young females with a history of chronic stress on the foot and a poor bony block (14 cases). Satisfactory results were obtained by treating the instability with a brace or by reconstruction of the interosseous talocalcaneal ligament

In a prospective study we assessed the causes of mechanical failure in a series of 230 intertrochanteric femoral fractures which had been internally fixed with either a sliding hip screw or a Kuntscher Y-nail. The overall rate of mechanical failure was 16.5%; cutting-out of the implant from the femoral head was the cause in three-quarters of the instances. Implants placed posteriorly in the femoral head cut out more often (27%) than those placed centrally (7%). The cut-out rate was also determined by the quality of the fracture reduction, but age, walking ability and bone density (assessed by the Singh grade and metacarpal indices) had no significant influence. We conclude that these fractures should be reduced as accurately as possible and it is imperative that the implant is placed centrally within the femoral head

Using roentgen stereophotogrammetry we have recorded the three-dimensional movements of the knee during an anteroposterior laxity test in 36 patients with torn anterior cruciate ligaments and in three cadaver knees. At 30 degrees of knee flexion and before loads were applied the tibia occupied a more laterally rotated position if the anterior cruciate ligament had been injured. When the tibia was pulled anteriorly knees with cruciate deficiency rotated more laterally and were more abducted than normal knees. Posterior traction induced lateral rotation in the injured knee and medial rotation in the intact one. Precise knowledge of the three-dimensional instability of the anterior cruciate deficient knee may be important when the laxity is evaluated only in relation to one of the three cardinal axes

In the Trillat procedure for recurrent anterior instability of the shoulder the coracoid process is osteotomised and tilted downward to act as a bone block, and a screw is used to fix it and the Bankart lesion to the anterior scapular neck. We reviewed 52 cases after a mean follow-up of 69 months. Results in 73% of shoulders were excellent, 10% were good, 7% fair and 10% poor. Dislocation recurred in 4%, but a positive apprehension sign was present in 10 other shoulders. Some degenerative changes were seen in 62% of shoulders, a complication known to be associated with bone-block procedures. The most important reason for loss of lateral rotation was iatrogenic impingement of the coracoid. This frequent and potentially serious complication can also cause posterior subluxation of the humeral head and osteoarthritis

One-hundred and seventy patients with 252 club feet treated by early posterior release were reviewed after a follow-up averaging 15 years 10 months. The feet were assessed both functionally and clinically and the results related to any bony deformity found radiographically; a satisfactory result was obtained in 81%. Lateral tibial torsion was examined and found to be less than in a normal population. The relationship between primary bone deformity and eventual functional result was examined, and a classification of talar dome deformity introduced. The range of ankle movement was a major factor in determining the functional result, and this in turn was influenced by the degree of talar dome flattening. It is suggested that the primary bone deformity present at birth dictates the eventual result of treatment

Eleven patients with metastases in the cervical spine had operations for severe pain due to a pathological fracture which, in eight of the cases, was unstable. Conservative treatment had either failed or was unsuitable. In the first five patients internal fixation with tension band wires and bone grafts was supported by a halo-brace. The method has evolved to the use of posterior instrumentation with laminar wires from two levels above the lesion to two levels below. Stability is increased by the use of bone cement with or without bone autografts applied to one side of the spine. This technique enables the patient to get up within a few days of operation--a great advantage when life expectancy is limited. The operations were successful in all except one case

The management of traumatic dislocation of the knee in 40 patients (41 knees) with a mean age of 26.3 years is described. They were treated by primary repair and reconstruction with autologous grafting of the anterior (ACL) and posterior cruciate ligaments (PCL) and repair injuries to the collateral ligament and soft-tissue. The ACL and PCL were reconstructed using the patellar tendon and the gracilis and semitendinosus tendons, respectively. Early mobilisation using a continuous-passive-movement machine and active exercises was started on the second day after operation. At a mean follow-up of 39 months no patient reported ‘giving way’ and all except one had good range of movement. Of the 41 knees, 21 were rated as excellent, 15 good, four fair and one poor. Early reconstruction of the cruciate ligaments and primary repair of the collateral ligaments followed by an aggressive rehabilitation programme are recommended for these young, active patients

Five patients with long-standing, severe rheumatoid arthritis who developed cervical myelopathy at the subaxial levels are presented. In each patient the myelopathy occurred in the absence of major subluxation. At laminectomy the cause of the cord compression was found to be a band-like mass of ligamentous and granulation tissue in the posterior half of the extradural space, extending to the underlying portion of the dura and forming a constricting ring. In three patients this constricting ring was released by longitudinal division of the dura followed by application of a fascial patch graft. This release seems to be essential for effective decompression of the cord and good neurological recovery was achieved in these three patients. Of the other two patients, the result was fair in one and poor in the other, this latter result being due to severe intra-operative bleeding with a massive wound haematoma

The management of an anterior supracondylar fracture by closed reduction, traction, percutaneous pinning or open reduction is seldom satisfactory, especially for adults and the aged with a lesser ability to remodel and a slower functional recovery. A new, safe, and simple technique is described in which the condylar mass is pushed posteriorly along the axis of the forearm and the hand is rotated to full supination while the elbow is held in flexion to correct deformities. Fixation is divided into two parts: the circular cast around the upper arm provides a firm buttress onto which the lower fragment is reduced and then the arm is immobilised in a plaster which includes the wrist. Four cases of delayed, comminuted, compound fractures have been fully evaluated clinically and radiologically and the results assessed as good or excellent

1. By unilateral resection of the posterior ends of the sixth to eleventh ribs including the costal parts of both costo-vertebral joints, progressive scoliosis can regularly be provoked in young rabbits. Rotation of the vertebrae is prominent in the experimental deformity. 2. Although severe progressive scoliosis can be provoked by a surgical procedure we do not yet know the deforming forces which are released by the operation, but the way lies open for accurate studies on these factors. 3. It seems possible that studies on experimental progressive scoliosis may provide us with new methods to counteract or cure scoliosis in children. The goal is a means to reverse the deforming forces during growth so that the child's spine is straight when growth ceases

Percutaneous repair of the ruptured tendo Achillis has a low rate of failure and negligible complications with the wound, but the sural nerve may be damaged. We describe a new technique which minimises the risk of injury to this nerve. The repair is carried out using three midline stab incisions over the posterior aspect of the tendon. A No. 1 nylon suture on a 90 mm cutting needle approximates the tendon with two box stitches. The procedure can be carried out under local anaesthesia. We reviewed 27 patients who had a percutaneous repair at a median interval of 35 months after the injury. They returned to work at four weeks and to sport at 16. One developed a minor wound infection and another complex regional pain syndrome type II. There were no injuries to the sural nerve or late reruptures. This technique is simple to undertake and has a low rate of complications

Patients suffering from generalised convulsions may dislocate their shoulders either anteriorly or posteriorly. Those with anterior dislocation are likely to have recurrent episodes because of secondary bony damage to the anterior rim of the glenoid and head of the humerus. In such patients there is high rate of failure of the standard soft-tissue stabilisation procedures. We have therefore devised a bone buttress operation in which autograft or allograft is secured to the deficient anterior glenoid and shaped to form an extension of its articular surface. We report our experience in 14 patients with grandmal epilepsy and recurrent anterior dislocation of the shoulder. After the bone buttress operation there were no further dislocations and all patients were satisfied despite a small restriction in their range of movement. We believe this to be the operation of choice for patients with this difficult problem

Aims

We compared the clinical and radiological outcomes of using a polyetheretherketone cage with (TiPEEK) and without a titanium coating (PEEK) for instrumented transforaminal lumbar interbody fusion (TLIF).