It has been known for well over a century that the corresponding ossification centres of the hand tend to appear before those of the foot (Mall 1906), although even now the range of variability remains poorly defined. Presumably a similar asynchrony also obtains for chondrification, although precise timing is more difficult here than for ossification. Accordingly, it is tempting with respect to this syndrome to relate fusions restricted to the phalanges of the hand and to the tarsal bones to the action of a gene which during a very limited period of development exerts an effect on those small bones of the hand and foot which are in a very specific stage of development. But since there are other inherited abnormalities of the skeleton, such as brachydactyly, where homologous bones are involved, it is clear that at the descriptive level gene action can either appear to be "stage-specific" or "homologue-specific." There are also mutations affecting the axial skeleton such as the type of polydactyly of the foot described by Neel and Rusk (1963) which appear to be neither "stage" nor "homologue" specific, involving only the foot. Finally then, there are syndromes, such as Lawrence-Moon-Biedl-Bardot, in which involvement of the hands and feet (polydactyly) is associated with such other apparently completely unrelated defects as retinitis pigmentosa and hypogonadism. While it is tempting to try to construct theoretical patterns and systems of developmental processes on the basis of results such as these, it is clear that the ultimate understanding of how genes can appear to act in so many ways almost certainly depends on the identification of a genetically controlled, qualitative or quantitative biochemical lesion. With the current parallel developments in biochemical and developmental genetics, new insights into these enigmas will surely be forthcoming in the relatively near future

A study of limb shortening after poliomyelitis in 225 children in whom paralysis was confined to one leg shows:. 1. The paralysed leg became shorter than its fellow in 219 patients (97 per cent). 2. The discrepancy in leg length only once exceeded three and a half inches. 3. Both the tibia and the femur were shorter than their fellows in 171 out of 184 studied (93 per cent). In only one patient was the femur alone shortened. 4. Three patterns of progress of shortening are described. No evidence was found that reduction of shortening ever occurs. 5. It is impossible accurately to predict shortening. In general, the more severe the paralysis the greater the shortening, but there are notable exceptions. 6. No relationship could be found between the amount of shortening and the incidence of paralysis of any individual muscle-group. 7. There was no significant difference in leg shortening in adult life between those who had developed the disease in the first two years of life and those who had developed it later. 8. A cold blue limb is not more likely to undergo severe shortening. 9. When the paralysis was confined below the knee the greatest shortening seen was one and three-quarter inches. When muscles both above and below the knee were involved severe paralysis may produce shortening up to three and a half inches. 10. Lengthening of a paralysed leg can occur during the first two years after the onset of the disease, but this is always a temporary phase. 11. The cause of leg shortening is unknown. In only two patients in this series was there evidence of premature epiphysial fusion

Aims

There is little information about the optimum number of implants to be used in the surgical treatment of idiopathic scoliosis. Retrospective analysis of prospectively collected data from the Swedish spine register was undertaken to discover whether more implants per operated vertebra (implant density) leads to a better outcome in the treatment of idiopathic scoliosis. The hypothesis was that implant density is not associated with patient-reported outcomes, the correction of the curve or the rate of reoperation.

We have evaluated the use of a synthetic porous ceramic (Triosite) as a substitute for bone graft in posterior spinal fusion for idiopathic scoliosis. In a prospective, randomised study 341 patients at five hospitals in the UK and France were randomly allocated either to autograft from the iliac crest or rib segments (171) or to receive Triosite blocks (170). All patients were assessed after operation and at 3, 6, 12 and 18 months. The two groups were similar with regard to all demographic and baseline variables, but the 184 treated in France (54%) had Cotrel-Dubouset instrumentation and the 157 treated in the UK usually had Harrington-Luque implants. In the Triosite group the average Cobb angle of the upper curve was 56°, corrected to 24° (57%). At 18 months, the average was 26° (3% loss). In the autograft group the average preoperative upper curve of 53° was corrected to 21° (60%). At 18 months the mean curve was 25° (8% loss). Pain levels after operation were similar in the two groups, being mild in most cases. In the Triosite group only three patients had problems of wound healing, but in the autograft group, 14 patients had delayed healing, infection or haematoma in the spinal wound. In addition, 15 autograft patients had pain at the donor site at three months. Seven had infections, two had haematoma and four had delayed healing. The haematological and serum biochemistry results showed no abnormal trends and no significant differences between the groups. There were no adverse events related to the graft material and no evidence of allergenicity. Our results suggest that Triosite synthetic porous ceramic is a safe and effective substitute for autograft in these patients. Histological findings on biopsy indicate that Triosite provides a favourable scaffolding for the formation of new bone and is gradually incorporated into the fusion mass

Aims

A failed total ankle arthroplasty (TAA) is often associated with much bone loss. As an alternative to arthrodesis, the surgeon may consider a custom-made talar component to compensate for the bone loss. Our aim in this study was to assess the functional and radiological outcome after the use of such a component at mid- to long-term follow-up.

Infection after intradiscal injections has been recognised as a distinct entity, but discitis after discography has often been attributed to an aseptic process or a chemical reaction to the contrast material. We examined the hypothesis that discitis after discography is always due to infection, and report a clinical review and an experimental study. Part I. We reviewed the case records and radiographs of 432 patients who had undergone lumbar discography. When an 18-gauge needle without a stilette had been used, discitis was diagnosed in 2.7% of 222 patients but stiletted needles and a two-needle technique at each level reduced the incidence to 0.7%. Seven patients with discitis after discography had undergone anterior discectomy and fusion; in them the histopathological findings were of a chronic inflammatory response. Bacteria were isolated from the discs of three of the four patients who had open biopsy less than six weeks from the time of discography. These findings suggest that bacteria were initiators rather than promoters of the response. Part II. Multiple level lumbar discography was carried out in mature sheep, injecting contrast material with or without various concentrations of bacteria. Radiographs were taken and the discs and end-plates were examined histologically and cultured for bacteria at intervals after injection. None of the controls showed any evidence of discitis but all sheep injected with bacteria had typical radiological and histopathological changes by six weeks, though cultures were almost all negative. However, at one and two weeks after injection, but usually not after three weeks, bacteria could be isolated. We suggest that all cases of discitis after discography are initiated by infection, and that a very strict aseptic technique should be used for all injections into intervertebral discs

A study has been made of fifty-six patients suffering from rheumatoid arthritis in whom sixty-nine wrists were fused. The purpose of the investigation was to evaluate to what extent the position of the fused wrist influenced the position of the fingers in the frontal plane. All sixty-nine wrists were followed up by radiographic examination controls, and thirty-seven of the wrists were also examined clinically. The mean period of observation after operation was seven years and ten months. The findings support the so-called "zigzag" theory based on the concept of carpus-metacarpus acting as Landsmeer's intercalated bone in a bi-articular system. When the wrists were fused in more than 5 degrees of radial deviation seventeen of twenty hands showed ulnar drift of the fingers on radiographic examination. Of the nine patients in this group examined clinically, all showed ulnar drift. A strong tendency to correction of the finger position is seen when the hands are pressed against the cassette. For this reason the clinical examination, during which the finger deviation was examined with the metacarpo-phalangeal joints in 30 degrees of flexion regularly revealed an ulnar deviation of 5 degrees more than that shown by radiographic examination. In eighteen wrists the fusion had been done in more than 5 degrees of ulnar deviation. Fourteen of these hands showed a resulting radial deviation of the fingers on radiographic examination. In a group of thirty-one wrists fused in neutral position (0 degrees±5 degrees) only six hands showed more than 5 degrees of finger deviation to either side. The condition of the metacarpo-phalangeal joints asjudged from radiographs did not seem to influence the deviation of the fingers either in direction or in degree. The direction of the deviation of the fingers was almost regularly the opposite to that of the fused wrist. Five hands showing no visible pathological changes in the metacarpo-phalangeal joints displayed finger drift

Aims

This study aimed to investigate the role of quantitative histological analysis in the diagnosis of fracture-related infection (FRI).

One hundred and fifty patients in Hong Kong with a diagnosis of tuberculosis of the thoracic, thoracolumbar or lumbar spine were allocated a random to the "Hong Kong" radical resection of the lesion and the insertion of autologous bone grafts (Rad. series) or to debridement of the spinal focus without bone grafting (Deb. series). All patients received daily chemotherapy with para-aminosalicylic acid (PAS) plus isoniazid for 18 months, with streptomycin for the first three months. After exclusions, the main analyses of this report concern 119 patients (58 Rad., 61 Deb.) followed up for 10 years. During the first five years the allocated regimen was modified because of the spinal lesion in 14 patients, but there were no further modifications between five and 10 years. No patient developed a sinus or clinically evident abscess or a neurological abnormality between five and 10 years. Bony fusion occurred earlier and in a higher proportion of patients in the Rad, series but at five and 10 years there was vary little difference between the series. Over the period of 10 years there was a mean increase in vertebral loss of 0.05 of a vertebral body in the Rad. series and 0.23 in the Deb. series. In both series most of this loss occurred in the first 18 months, with very little subsequent change in the next eight and a half years. Over the 10 years there was a mean reduction in the angle of kyphosis in the Rad. series of 1.4 degrees for patients with thoracic and thoracolumbar lesions and 0.5 degrees for those with lumbar lesions. By contrast, in the Deb. series there were mean increases in the angle of 9.8 degrees and 7.6 degrees respectively. In both series most of the changes had occurred early, and persisted subsequently. At 10 years 57 of 58 Rad. and all 61 Deb. patients had a favourable status, 50 (86 per cent) and 54 (89 per cent) respectively on the allocated regimen without modification

1. Details are given of sixty-three consecutive cases with a history of pleural effusion seen at an orthopaedic hospital. 2. Twenty-four of these were post-primary effusions occurring before the onset of symptoms of the orthopaedic lesion. The bone and joint lesions ultimately developing in this group of patients were widely scattered throughout the skeleton. 3. Three others were secondary to adult-type pulmonary lesions. 4. Thirty-six patients had a pleural effusion after the beginning of their orthopaedic tuberculous history. Seven were certainly secondary to operative intervention, six in the thorax near the parietal pleura (costotransversectomy or antero-lateral decompression of the cord) and one from a haematogenous dissemination after fusion of a hip joint. 5. The remainder of this group with pleural effusion during the history of their orthopaedic tuberculous disease numbered twenty-nine. Of these, twenty-five suffered from disease of the thoracic spine; in two more details are defective. Only two definitely had neither pulmonary nor thoracic spinal disease; their lesions were in the lumbar spine. The conclusion is drawn that the overwhelmingly common cause of pleural effusion in patients with orthopaedic tuberculosis who have normal lungs and have not recently suffered spinal decompression is transpleural infection from thoracic spinal disease and that the sequence is by no means rare. It had occurred in approximately one in six of 145 patients with thoracic Pott's disease seen during this investigation. 6. Details are given of a group of cases with thoracic paravertebral abscess tracking laterally. When the abscess is well clear of the spine and spinal ligaments it may project forwards and radiologically it may appear in the antero-posterior chest film as a shadow in the middle of one or other lung field rather than as a shadow obviously connected with the central paravertebral abscess. Aspiration will yield pus from this posterior extra-pleural abscess extension. 7. The belief that Pott's disease most commonly follows direct spread from caseous paraaortic glands secondary to tuberculous pleurisy is discussed. It is concluded that the evidence is insufficient for so sweeping a statement

1. Nine hundred and fourteen cases of tuberculosis of the spine are analysed and the late results ascertained three or more years after discharge from hospital. 2. The relative frequency with which the various segments of the spine are involved has been found. Cervical disease was present in 3·5 per cent of cases, thoracic in 43·l per cent, lumbar in 32·9 per cent, thoraco-lumbar in 16· 7 per cent and lumbo-sacral in 3·8 per cent. 3. The mortality rate was 16·7 per cent. In patients with multiple lesions 25·5 per cent died, compared with 12·3 per cent in the group without complications. When chronic secondarily infected abscesses and sinuses were present the mortality rate was 19·1 per cent, and of patients with paraplegia 24·8 per cent died. 4. In the late results the working capacity of 390 patients was ascertained. It was full in 86 per cent, partial in 5·8 per cent and nil in 8·2 per cent. 5. An attempt has been made to determine the site of the primary bone focus from the radiograph. Early "epiphysial" changes were present in 33 per cent ; the central focus beginning in the spongy tissue of a vertebral body was present in 11·6 per cent; subperiosteal lesions were present in 2·1 per cent; and infection of the neural arch was present in only 0·5 per cent. In 52·8 per cent, however, widespread destruction had taken place when the patient first came under observation. 6. The ill effect of complications upon the prognosis is stressed—especially in the cases of multiple foci of active tuberculosis, secondarily infected abscesses and sinuses, and paraplegia. Paraplegia occurred in 31·2 per cent of the cases of thoracic disease. 7. An attempt has been made to determine the frequency with which tuberculosis of the spine heals by spontaneous bony fusion of the affected vertebral bodies. It was found in 27·3 per cent of the cases in the present series. 8. Reasons for further treatment after the initial discharge of the patient are examined

Fusion is the main goal in the surgical management of the injured and unstable spine. A wide variety of implants is available to enhance this. Our study was performed to evaluate the stabilising characteristics of several anterior, posterior and combined systems of fixation. Six thoracolumbar (T11 to L2) spines from 13-week-old calves were first tested intact. Then the vertebral body of T13 was removed and the defect replaced and supported by a wooden block to simulate bone grafting. Dorsal implants consisting of a Universal Spine System (USS) fracture system and an AO Fixateur interne (AOFI), and ventral implants comprising of a Kaneda Classic, a Kaneda SR, a prototype of the VentroFix single clamp/single rod construct (SC/SR) and the VentroFix single clamp/double rod construct (SC/DR) were first implanted individually to stabilise the removal of the vertebral body. Simulating the combined anteroposterior stabilisations, all ventral implants were combined with the AOFI. The range of motion (ROM) was measured under loads of up to 7.5 Nm. The load was applied in a custom-made spine tester in the three primary directions while measuring the intervertebral movements using a goniometric linkage system. The dorsal systems limited ROM in flexion below 0.9° and in extension between 3.3° and 3.6° (median values). The improved Kaneda System SR yielded a mean ROM of 1.8° in flexion and in extension. The median rotation found with the VentroFix (SC/DR) was 3.2° for flexion and 2.8° for extension. Reinforcement of the ventral constructs with a dorsal system reduced the ROM in flexion and extension in all cases to 0.4° and lower. In rotation, the median ROM of the anterior systems ranged from 2.7° to 5.1° and for the posterior systems from 3.9° to 5.7°, while the combinations provided a ROM of 1.2° to 1.9°. In lateral bending, the posterior implants restricted movement to 1.1°, whereas the anterior implants allowed up to 5.2°. The combined systems provided the highest stability at less than 0.6°. Our study revealed distinct differences between posterior and anterior approaches in all primary directions. Also, different stabilisation characteristics were found within the anterior and posterior groups. Combinations of these two approaches provided the highest stability in all directions