Old calcified fibrin coagula are frequently found in simple bone cysts. They provide a scaffold on which new bone is laid down, in a process analogous to endochondral ossification. It is suggested that these coagula are derived in substantial part from the plasma-like contents of the cyst, after the release of plasma-clotting factors as the result of injury. Major haemorrhage is not involved and in many cases there is no antecedent fracture. The phenomenon is not seen in other common cystic conditions of bone and its recognition is thus helpful in the histological diagnosis of simple bone cyst. Cystic bone infarcts and their possible confusion with simple bone cysts are also briefly discussed

The "osteopetrosis" section of the Fairbank Collection in the Radiology Museum of the Royal National Orthopaedic Hospital contains radiographs and case notes of twenty-two patients. This material has been reviewed in terms of modern concepts in an attempt to obtain a long-term follow-up and a firm diagnosis in each individual. Nine patients proved to have the classical autosomal dominant form of osteopetrosis, four had the malignant autosomal recessive type, craniometaphyseal dysplasia was present in two kindreds and isolated individuals had pyknodysostosis, atypical craniodiaphyseal dysplasia and craniosclerosis with osteopathia striata. As these conditions differ greatly in their clinical and genetic prognoses, diagnostic categorisation is of practical importance

1. Thirteen cases of fracture of the lateral process of the talus seen over a period of thirteen months are reported. 2. The mechanism of the injury would appear to be inversion strain of the foot with dorsiflexion of the ankle. 3. The diagnosis would no doubt be made more often if the possibility of this fracture were kept in mind, and if radiographs of good quality were taken with the ankle at 0 degree and the leg rotated inwards 10 to 20 degrees. 4. With regard to treatment, early operation appears to give good results, a single large fragment being reduced accurately and small or comminuted fragments being removed

1. Twenty-eight patients with pyogenic infection of the spine are reported. 2. Diagnosis was by clinical, radiological and bacteriological means. Investigations of the spinal lesions by needle aspiration or open operation was needed in four patients. 3. Treatment consisted primarily of antibiotics and rest. 4. Twenty-five patients were fit and well after follow-up of one to fifteen years. Three deaths occurred, but only one was directly connected with the infection ; urinary infection with paraplegia and haemophilia were the cause in two others. 5. The relatively benign course is stressed, as are some of the diagnostic pitfalls in the early stages, particularly with thoracic lesions

1. Nine cases of disturbance of the relationship between the scaphoid and the radius and between the scaphoid and the lunate bones are described. 2. Persistent dislocation of the scaphoid bone may follow reduction of perilunar dislocations or of other dislocations of the proximal row of the carpus. It may be obvious, as in waist-deep dislocation, or may be solely a rotational dislocation which may be difficult to diagnose. 3. Uncorrected rotational dislocation of the scaphoid bone caused significant disability in six of seven cases. 4. Aids to the diagnosis of this condition are described and a vigorous approach to the problem of correction is advocated. 5. The experience of other workers in this field is reviewed and discussed

We made a prospective study of 58 patients with suspected internal derangement of the knee. They were examined by magnetic resonance imaging using 3-D gradient echo intermediate-weighted studies before having an arthroscopy. The preoperative clinical assessment was found to have a diagnostic sensitivity of 77% and a specificity of 43%, compared with 100% and 63% respectively for magnetic resonance imaging. Comparison of magnetic resonance imaging and arthroscopy confirmed the accuracy of magnetic resonance imaging in the diagnosis of internal derangement but the results for articular cartilage lesions were much less good, with a sensitivity of only 18% but a specificity of 100%. Acceptance of the magnetic resonance imaging findings could have resulted in a 29% reduction in the number of arthroscopies without missing any significant meniscal lesion

We reviewed 275 cases and calculated the prevalence of bacteriologically or radiologically confirmed acute haematogenous osteomyelitis in children under 13 resident in Greater Glasgow during 1970 to 1990. In the 20-year period there was a fall of over 50%, mainly involving cases of long-bone infection, and those due to Staphylococcus aureus. There was a reduced incidence of complications. The proportion of cases involving long bones decreased from 84% to 57%, and those of Staphylococcus aureus infection from 55% to 31%. These changes, in what is becoming a rare disease, need to be known to ensure early diagnosis and adequate treatment, particularly of subacute non-staphylococcal infection at unusual sites

We diagnosed 50 patients (58 shoulders) with a mean age at presentation of 17.3 years, as having involuntary positional instability of the shoulder. They were managed by a programme consisting of a careful explanation, analysis of abnormal muscle couples and then muscle retraining carried out by a specialist physiotherapist. The mean follow-up was two years. Six shoulders had a poor result, but 52 were graded as good to excellent. Nine patients (12 shoulders) relapsed and required further episodes of retraining. In our experience, involuntary positional instability of the shoulder causes symptoms which interfere with normal activities; these can be controlled by a treatment plan of retraining of the muscle pattern with functional benefit. Only 19 of the patients were referred with a diagnosis of positional instability. There should be more awareness of this rather uncommon condition. Surgery is not indicated in these patients

We reviewed a series of 91 patients with deep infection of a cemented total hip arthroplasty caused by coagulase-negative staphylococci (C-NS). Of these, 72 were treated by one-stage exchange arthroplasty with a failure rate of 13% due to recurrence of infection. The other 19 patients have started or completed treatment by a two-stage exchange without failure to date. In 27 of the 91 patients multiple strains of C-NS were discovered, many being resistant to previously used antibiotics. The use of gentamicin-containing cement in the primary arthroplasty was significantly associated with the emergence of gentamicin-resistant C-NS in subsequent deep infection. Bacteriological diagnosis of such infections must take into consideration the possibility that multiple strains of the organism are involved

In a retrospective review of 302 clinically suspected cases of congenital syphilis, bone changes were found in 197. The skeletal manifestations were periostitis (102 cases), osteitis (20), and metaphyseal changes (71). Combinations of more than one lesion were found in 61. Pseudoparalysis was a presenting sign in 34 infants; 12 of these were found to have had pathological fractures and four had dactylitis. Complete radiological healing without residual changes was seen in all 59 cases that were recalled for review. The orthopaedic surgeon should consider the diagnosis of congenital syphilis when destructive lesions of bone are seen in an infant

Objectives

Little is known about tissue changes underlying bone marrow lesions (BMLs) in non-weight-bearing joints with osteoarthritis (OA). Our aim was to characterize BMLs in OA of the hand using dynamic histomorphometry. We therefore quantified bone turnover and angiogenesis in subchondral bone at the base of the thumb, and compared the findings with control bone from hip OA.

Aims

The aim of this study was to compare the outcomes of surgery using growing rods in patients with severe versus moderate early-onset scoliosis (EOS).

We have analysed associated factors in 164 patients with acute compartment syndrome whom we treated over an eight-year period. In 69% there was an associated fracture, about half of which were of the tibial shaft. Most patients were men, usually under 35 years of age. Acute compartment syndrome of the forearm, with associated fracture of the distal end of the radius, was again seen most commonly in young men. Injury to soft tissues, without fracture, was the second most common cause of the syndrome and one-tenth of the patients had a bleeding disorder or were taking anticoagulant drugs. We found that young patients, especially men, were at risk of acute compartment syndrome after injury. When treating such injured patients, the diagnosis should be made early, utilising measurements of tissue pressure

Ten children who had clinically stable hips at birth were radiographed at one month because they had factors predisposing to hip dislocation. In all cases one or both hips gave rise to a suspicion of dysplasia, though clinical abnormalities were slow to appear. Four of these hips subsequently dislocated. We believe that infants with late presentation of acetabular dysplasia and clinical abnormality belong to a different aetiological group from those with neonatal instability due to ligamentous laxity. The significance of this differentiation is that some infants presenting late have only recently dislocated, and the diagnosis has not necessarily been "missed" at neonatal examination

The clinical and pathological features of six cases of desmoplastic fibroma of bone are presented. Desmoplastic fibroma is rarely seen as a primary tumour of bone; when it does occur the sites of predilection are the long bones, but other sites such as the scapula and os calcis can be involved. Radiographically the lesion tends to expand the bone from within; it is well-demarcated and lytic, often with a trabeculated soap-bubble appearance. The cellular structure and the morphological arrangement are similar to those of aggressive fibromatosis of soft tissues. Differential diagnosis from malignant spindle-cell lesions of bone is important because the treatment of choice for desmoplastic fibroma of bone is simply excision with a thin layer of healthy tissue

Aims

The use of a noninvasive growing endoprosthesis in the management of primary bone tumours in children is well established. However, the efficacy of such a prosthesis in those requiring a revision procedure has yet to be established. The aim of this series was to present our results using extendable prostheses for the revision of previous endoprostheses.

The operative and anaesthesic technique for 44 patients undergoing posterior spinal fusion with Harrington rod instrumentation for idiopathic scoliosis is described. There were two groups of 21 and 23 patients, matched for diagnosis and status before operation. The management of both groups was similar but in one group anaesthesia with induced hypotension was employed, using a mixture of sodium nitroprusside and trimetaphan. The mean blood loss at operation and after operation in this group was significantly lower than in the other group, with a consequent reduction in the transfusion requirement. No adverse sequelae were observed. All patients showed a drop in haemoglobin concentration after operation, despite clinically adequate blood transfusion

The clinical and radiological features in three cases of cystic angiomatosis of bone are reported. Although these features are generally diagnostic except from histiocytosis X, the definitive diagnosis must be established by a pathological study, preferably of a segment of an involved rib or fibula. The prognosis varies according to the type of clinical presentation-in particular upon whether the lesions are solely skeletal or whether there is extraskeletal visceral involvement. Whereas these last cases may often prove fatal, those with only skeletal involvement have a favourable prognosis: indeed, the cystic bone lesions may regress without any treatment, as occurred in some cases reported in the literature and in two of our three cases