Atlanto-axial rotatory fixation is one of a spectrum of rotatory abnormalities of the atlanto-axial joint. Rotatory fixation without anterior displacement of the atlas (Type I) has been reported in only a few cases in which there has been a prolonged interval between injury and diagnosis. The majority of these cases eventually required cervical fusion for persistent deformity or instability. Two cases are presented in which this diagnosis was made early with the aid of rotated odontoid radiographs, tomography and computerised axial tomography. Treatment by a short period of halter traction achieved reduction and early return of function. The authors conclude that early recognition and treatment of this rare condition may prevent the subsequent deformity and instability for which cervical fusion has been required.

A case is reported of fracture of the pedicles of the axis vertebra in an infant. Non-operative management in a Minerva cast resulted in union and full recovery without complications.

This report describes a nine-year-old girl with a spondylolisthesis of the C2 vertebra allowing 14 mm of slip. Her father had very similar vertebral anomalies.

A review of 77 patients with traumatic central cord syndrome revealed that atypical variations are more common than the existing literature suggests and that these may be seen in a wide variety of acute injuries to the cervical spine. In general the outcome is good; a favourable prognosis on admission is suggested by good hand function, hyperpathia, Lhermitte's sign and normal perianal sensation. The study has highlighted the value of regular muscle charting and has cast doubt on previous neuroanatomical assumptions about the syndrome.

Recent clinical studies have suggested that a neurological lesion may be a cause of adolescent idiopathic scoliosis and animal experiments have implicated the posterior column pathway. We have tried to determine if differences in neurological response could be detected and measured clinically, and have compared the threshold of detection of vibratory sensation in 20 girls with adolescent idiopathic scoliosis with that in 20 clinically normal age-matched controls. A highly significant reduction of the threshold of detection of vibration was seen in the scoliotic group compared to the controls (p less than 0.001). Curve magnitude did not correlate with this threshold for either the upper (r = 0.172) or lower extremity (r = 0.126). Significant asymmetry between right- and left-sided thresholds to vibration was demonstrated in the scoliotic group. Our study supports the concept that an aberration in the function of the posterior column pathway of the cord may be of primary importance in the aetiology of idiopathic scoliosis. A clinically practical test to measure this function is presented.

Magnetic resonance imaging (MRI) of the spine produces images which reflect the chemical composition of the intervertebral disc. We have conducted a prospective study of the serial changes in the MRI appearance of the intervertebral disc after chemonucleolysis with the enzyme chymopapain. Fourteen patients were studied after single-level chemonucleolysis and the results compared with a control group of 17 discs in six patients who had diagnostic discography without enzyme insertion. A consistent pattern of gradual loss of signal from the nucleus pulposus culminating in complete loss of nuclear signal was seen in all cases after chemonucleolysis. Chymopapain therefore produced MRI changes analogous with premature gross disc degeneration. The rate at which this occurred varied; complete loss of signal took at least six weeks. Transitory minor end-plate changes were present in five patients, probably representing a mild chemical discitis. No similar changes were seen in the discography group.

We have measured the increase in height and width of the vertebral bodies and expressed them as percentages of the total growth in children aged 10 to 17 years. The first group, 10 boys and 10 girls, each had a single thoracic adolescent idiopathic scoliosis while the second group, 10 girls, each had a single lumbar adolescent idiopathic scoliosis. No significant differences were found between the growth increments and spinal dimensions of the vertebral bodies involved in the scoliotic curve and those vertebrae outside the curve in the same patient. The vertebrae were more slender in girls than in boys.

Computerised tomography of the lumbar spine was performed on 22 patients with clinical evidence of prolapse of an intervertebral disc and normal or equivocal radiculograms. Of 11 patients with positive scans who had an operation the presence of pathology was confirmed in 10. Although CT scanning is always helpful in diagnosing disc disorders, where facilities are scarce (as in Great Britain) it is best employed in patients with negative or non-contributory radiculography.

Severe traction injuries may damage the brachial plexus at any level from the spinal cord to the axillary outlet. Investigation aims to determine the level of the injury for each of the nerves, trunks or cords, with particular reference to obtaining firm evidence of any intradural (pre-ganglionic) damage. We report the results of computerised axial tomography of the cervical spine in comparison with conventional myelography and with surgical exploration of the plexus. CT scanning with contrast enhancement greatly improves diagnostic accuracy, particularly at C5 and C6 root levels.

We describe the use of allogeneic human tendon as an intra-articular replacement for the anterior cruciate ligament. Depending on the type and degree of functional instability we recommend the addition, in some cases, of supplementary extra-articular procedures. We have reviewed 31 patients at least two years after operation and have found that 30 of them had been able to return to full sporting activities. The indications for operation and the techniques are discussed and the use of allogeneic tendon is recommended.

The existence of pulmonary metastases in patients presenting with osteosarcoma is known to indicate a poor prognosis. Lung resection of solitary lesions is now a standard treatment approach, but with limited successful long-term results. We report the progress of a 16-year-old girl with osteosarcoma of the proximal tibia who underwent 11 lung resections for pulmonary metastases over a two-year period, and who has since then been free of disease for seven years.

A study of 79 children with malunion of forearm fractures is presented. Age at the time of injury, the site of the fracture and the degree and direction of angulation at union were correlated with loss of forearm rotation at review 3.5 to 6 years later. Some guidelines are proposed for the acceptability of angular deformity at union, importance being placed on the avoidance of radial deviation of the radius, and the maintenance of the interosseous gap between the shafts of the radius and ulna.

A simple method of radiological assessment has been used to measure the angle between the long axis of the humeral shaft and the growth plate of the capitellum (the Baumann angle). In the normal arm a significant relationship was found between the Baumann angle and the carrying angle. The Baumann angle was also measured after reduction of supracondylar fractures of the humerus and was found to correlate well with the final carrying angle measured at follow-up. There was no significant difference between the Baumann angle after reduction and that measured at follow-up; and it is suggested that this angle after reduction can be reliably used to predict accurately the final carrying angle.

Five patients suffered injuries around the wrist complicated by acute tunnel syndrome. Pain associated with median nerve paraesthesia or hypo-aesthesia are indications for urgent treatment; in four patients where operation was delayed, the outcome was poor.

A medical and engineering study was made of 1074 car accidents involving 2520 vehicle occupants. The injuries they sustained were correlated with details of the crash and with contact points inside the cars. Where possible the forces which were generated in the crash were estimated and related to the injuries. In all, 39 car occupants suffered femoral shaft fracture, with an incidence of 1.7% and 0.8% for front and rear seat occupants respectively. Of these, 31 had associated injuries to other regions of the body; these were the cause of 13 of the 14 deaths in this group. Associated injuries were more severe in car occupants who were not wearing seat belts but the incidence of femoral fracture was not significantly different. The mean velocity change (delta-V) causing femoral fracture was 26 mph (42 km/h) and there was a higher incidence of femoral shaft fracture when delta-V was over 30 mph. Estimates of forces needed to cause fracture were higher than those found in cadaver studies. The time to union of femoral fractures did not correlate with the severity of the crash but was longer (mean 19 weeks) than the average for other femoral fractures.

In paralytic lesions in which the triceps surae is the only active muscle in the leg, elongation or division of the tendo calcaneus alone may not be enough to prevent recurrence of equinus deformity. In 10 patients (13 limbs) with this pattern of muscle activity, equinus deformity was treated by hemitransplantation of the tendo calcaneus. At follow-up, which was beyond the end of growth in seven limbs, there was no recurrence of deformity in nine. In three of the four failures, a technical fault may have caused loss of activity in the transplanted part of the tendon. The two-stage operation described is recommended in the management of this pattern of paralytic deformity.

Twenty patients were examined by standard radiography and roentgen stereophotogrammetric analysis (RSA) during a two-year period after total hip arthroplasty. Eleven of the acetabular components migrated cranially and three femoral components migrated distally. This migration was most rapid during the first four months after operation. Our findings support the possibility that mechanical loosening is initiated by thermal injury during polymerisation of the cement; the less frequent migration of the metallic femoral component compared with the polyethylene acetabular component may be because the metal acts as a heat sink. Standard radiographs were inadequate for assessment of early mechanical loosening, whereas RSA could reveal migration within four months of the arthroplasty.

A bulky compression dressing (the Robert Jones bandage) is often used by orthopaedic surgeons. We have reviewed its history and monitored intramuscular compartment pressure under it after total knee replacement. We found that it increased compartment pressure and helped to reduce bleeding, tissue oedema and the size of effusions and haemarthroses.

A 15-year-old girl presented with a very large desmoid tumour in her buttock; it extended into the pelvis and thigh and would have required hindquarter amputation for its removal. This was not performed and the tumour underwent spontaneous regression. Fourteen years later the patient is alive and well. The suggestion is made that in some cases a more expectant approach to treatment might be justified for what is essentially a non-malignant condition.

Proximal tibial osteotomy is commonly performed for osteoarthritis of the knee with deformity. The results of 105 dome osteotomies have been reviewed at a minimum follow-up of one year and an average of 4.8 years. Before operation all the knees were painful, 50.5% severely; a further 45.7% disturbed sleep at night. At review 15.2% of knees were free of pain and 60% had only slight pain which did not restrict activity. The preoperative range of movement was maintained and there was only a slight tendency for radiological changes to progress, with actual improvement in some cases. No correlation was found between the correction of deformity to physiological valgus and the result. We cannot explain why tibial osteotomy produces such useful and sustained pain relief.

The St Georg modular knee replacement has been studied in 59 cases with an observation period ranging from 28 to 73 months. In 47% of the knees both compartments were replaced; five of the six poor results were in this group. These were revised to a hinge arthroplasty or, in one case, to an arthrodesis. Other complications were few and insignificant. There were no infections. We concluded that unicompartmental knee arthroplasty can be recommended when joint involvement is localised to one compartment only. With more generalised joint disease we prefer a semiconstrained total condylar prosthesis.

Five children with chronic renal failure and severe rachitic deformities of the lower limbs were treated with 1 alpha-hydroxyvitamin D (1 alpha-OHD3) for 16 to 53 months. There was symptomatic, biochemical and radiological improvement in all five children and operative correction of their deformities was not needed. We recommend a trial of treatment with 1 alpha-OHD3 for this condition before surgical procedures.

A prospective nation-wide study of knee arthroplasty has been under way in Sweden since October 1975. By the end of 1983, 4505 arthroplasties for osteoarthritis and 3495 for rheumatoid arthritis had been recorded and reviewed one, three and six years after the operation. Using actuarial methods, the probability of the prosthesis remaining in situ after six years was calculated. In osteoarthritis this probability ranged from 65% for hinged prostheses to 90% for medial compartment prostheses. Two-and three-compartment prostheses produced intermediate results with 87% survival. In rheumatoid arthritis the probability varied from 72% for medial compartment prostheses to 90% for two- and three-compartment prostheses. The main reason for failure was loosening of the components, the second most common was infection. The probability of revision for infection by six years was 2% in osteoarthritis and 3% in rheumatoid arthritis. Most revisions were to a three-compartment prosthesis. Knee fusion at primary revision was required in 2% of the cases at six years.

Free osteocutaneous fibular grafts, revascularised by microvascular anastomoses, have been used for one-stage reconstruction of extensive bone and skin loss in the lower leg in seven patients. The addition of an integral skin flap to a vascularised fibular graft makes reconstruction of bone defects with significant skin loss possible, and the technique for designing and raising such a flap is presented. The advantages of this transfer over other microvascular osteocutaneous flaps are the available length of straight cortical bone, the large thin skin flap, the good diameter of the vascular pedicle and the fact that dissection is carried out under a tourniquet.

A prospective study was made of 119 children with transient synovitis or any other cause for synovial effusion and elevated intra-articular pressure. During a follow-up of one year not one case of Perthes' disease was diagnosed and the late clinical and radiographic changes were minimal with moderate overgrowth of the femoral head in 33% and widening of the joint space in 14.2%. Our results do not support the widely accepted concept that Perthes' disease develops as a result of the period of elevated intra-articular pressure found in transient synovitis. Further research into this and Perthes' disease should follow the premise that they are two different diseases without any aetiological connection.

Early mobilisation after arthroplasty of the knee sometimes results in wound breakdown. The two commonly used incisions, the anterior midline and the medial parapatellar incisions, were compared in order to determine which had the best potential for wound healing. Study of the cleavage lines around the knee demonstrated that the medial parapatellar incision lies parallel to the lines, whilst the anterior midline incision lies perpendicular to them. In addition, the medial parapatellar wound was found to be subjected to significantly less tension during flexion; after arthroplasty it can be expected to heal faster and to be less liable to disruption during early mobilisation.

After having had a standard decompression for anterior compartment syndrome, five patients presented with persistent symptoms and pressure values above normal. A repeat procedure combined with fasciectomy relieved their pain; postoperative pressure values were normal.

The aetiology of pain in the lower leg during exercise has been studied in 110 athletes by monitoring intracompartmental pressure during exercise and by technetium bone scans. Patients were assigned to three diagnostic groups: chronic compartment syndrome, medial tibial syndrome and those with non-specific findings. Our results indicate that subcutaneous fasciotomy of the affected compartment(s) is the treatment of choice for chronic compartment syndrome. The treatment of patients with medial tibial syndrome, either by operation or conservatively, has been unsuccessful; non-specific symptoms have been treated conservatively with success.

A case is reported in which an epithelioid sarcoma developed in an apparently benign enchondroma or bone infarct at the site of a chrome-cobalt total knee replacement.

Instability of the knee is frequently found in association with congenital leg-length discrepancy. We have studied six such patients clinically, radiologically and arthroscopically. Clinical signs of knee instability and significant radiological changes were present in all, and at arthroscopy the anterior cruciate ligament was completely absent in four patients and functionless in the other two. This deficiency appears to be a congenital condition which may predispose to meniscus injury or retropatellar pain; it may also lead to subluxation or dislocation of the knee during leg-lengthening procedures.

An orientated substratum has been implicated in the development and regeneration of axons and synapses. We prepared a basement membrane matrix from autogenous striated muscle, used it to repair the sciatic nerve in rats, then investigated the results by histology and electrophysiology. When treated grafts were coaxially aligned with the nerve fascicles functional recovery appeared within 30 days, with good growth of axons into the distal nerve. Grafts with myotubes at right angles to the nerve fascicles supported nerve regeneration but at a slower rate. Grafts of coaxially aligned but untreated muscle allowed axon penetration only through naturally degenerated muscle fibres, with minimal axon penetration of the distal nerve. It is concluded that in the rat a treated graft with correctly orientated empty myotubes can facilitate and guide the regeneration of peripheral nerve after injury and so lead to recolonisation of the distal stump with functional recovery.

Ball-and-socket ankle is a rare deformity associated with such pre-existing conditions as congenital shortening of the lower limb, coalition of tarsal bones, absent digital rays and aplasia or hypoplasia of the fibula. We have observed seven patients with this deformity for an average of six years from initial examination at 20 days to 3.5 years. Arthrography showed that the configuration of the ankle was apparently normal in patients under 10 months of age and that a ball-and-socket joint develops by four to five years of age, possibly in compensation for the loss of inversion and eversion caused by tarsal coalition. Ball-and-socket joint is therefore probably not congenital, but is an acquired deformity secondary to various pre-existing congenital conditions.