We performed 41 core decompressions in 32 patients for stage I or stage II osteonecrosis of the femoral head. The intra-osseous pressure at the intertrochanteric level was raised in 28 (68%) and there was histological confirmation of necrosis in 36 hips (88%). After a follow-up of 10 to 84 months (mean 31) nine of the 12 stage I hips (75%) showed significant clinical or radiological deterioration; no evidence of necrosis had been found in the core specimens of the other three hips. Of the 29 hips in stage II, 25 (86%) showed significant radiological deterioration, and only five (17%) had improved clinically. We believe that once necrosis has occurred, core decompression will not significantly influence the subsequent course of the disease

We studied cartilage degeneration in 45 canine acetabula after implantation of prostheses with articulating surfaces of low-temperature isotropic (LTI) pyrolytic carbon, cobalt-chromium-molybdenum alloy and titanium alloy for periods ranging from two weeks to 18 months. Gross specimens and histological sections were compared with the nonoperated (control) acetabulum of the same animal. Cartilage articulating with LTI pyrolytic carbon exhibited significantly lower levels of gross wear, fibrillation, eburnation, glycosaminoglycan loss, and subchondral bone change than with metallic surfaces. Survivorship analysis showed a 92% probability of survival for cartilage articulating with LTI pyrolytic carbon at 18 months, as compared to only a 20% probability of survival for cartilage articulating with either of the metallic alloys

We examined the structure of the digital flexor sheath by dissection and histology. The inner aspect of the sheath was found not to be a continuous smooth surface, as depicted in anatomical and surgical texts. The thin parts of the sheath often overlapped the pulleys before attaching to their superficial aspects, so that the pulleys possessed free edges within the sheath. The frequency of occurrence and sizes of these overlaps were studied in 48 cadaveric fingers; the largest and most frequent overlap was at the distal end of the A2 pulley. Functional studies showed an intricate mechanism of pulley approximation and sheath bulging during flexion. Sutured or partly cut tendons triggered on the free edges; this could be a major contributor to the failures of tendon repairs in "no man's land"

Multiple tumours of peripheral nerves are often seen in patients with neurofibromatosis of type 1 or 2. Multiple schwannomas may occur without other manifestations of neurofibromatosis. We have reviewed 12 patients with multiple schwannomas arising from peripheral lesions who did not fulfil the criteria for either type of neurofibromatosis. Four had spinal and one an intracranial lesion in addition to the peripheral tumours. Two patients had one and three café-au-lait spots, respectively, and another had a probable family history. The largest tumours were 45 to 250 mm in size. Three patients had been referred as having von Recklinghausen’s disease. The large size of tumours, the difficulties of histological diagnosis on biopsy, and the confusion with neurofibromatosis can lead to overtreatment. Malignant change seldom, if ever, occurs in patients with multiple schwannomas

Hyperphosphatasia, or hereditary bone dysplasia with hyperphosphatasaemia, is a rare genetic disorder which is characterised by failure to transform woven into lamellar bone. Clinical, radiological and histological features establish the diagnosis, fractures, deformities, diffuse sclerosis on radiographs and high serum alkaline phosphatase being characteristic. We report the case of a 27-year-old man with follow-up at the same hospital for 20 years. Attempts at treatment with calcitonin and disocium etidronate (EHDP) failed, but stapling of the growth plates at the knee was successfully performed. Transverse "brittle" fractures of the humerus, lower leg and ribs healed normally, but internal fixation and late bone grafting were required for a subtrochanteric stress fracture of the femur at the age of 24 years. At present the patient has no clinical problems and leads a normal life

A study was made of the clinical course of 102 cases of fibrosarcoma of long bones. Of these, 55 were predominantly fibroblastic or pure fibrosarcomata while 47 contained extensive areas resembling so-called malignant fibrous histiocytoma (MFH). Treatment was similar in the two groups, and the five-year survival was the same, 34%, in both groups. Lung metastases developed in 63% of the fibroblastic sarcomata and 59% of the MFH-like tumours. Our study indicates that there is no significant difference in behaviour in fibrosarcoma with or without marked MFH features. The histological grading of both groups of fibrosarcomata together was of prognostic value; five-year survival was 64% in 14 Grade I tumours, 41% in 32 Grade II tumours and 23% in 56 Grade III tumours

In order to study the effect of pure torsional forces upon the rotational development of the growing tibia, 35 immature rabbits underwent torsional loading of one tibia in vivo with a spring-loaded cylinder while the other tibia was a control. The radiographic results showed rotation occurring only at the epiphysial plate. Histologically this was assocaited with angulation of the hypertrophic cartilage columns occurring as little as 24 hours after loading which with longer periods of loading produced angled primary and secondary trabeculae. Radiographic and histological analyses of the diaphysis using tetracycline labelling and Spalteholtz injection techniques failed to show any evidence of cortical remodelling or reorientation of the cortical vessels of a rotational nature, suggesting that rotational modelling occurs solely at the epiphysial plate

This paper reports a detailed examination of three lesions of aseptic necrosis of bone occurring in a man who had worked in compressed air eleven years previously. Although two of the lesions were juxta-articular, in neither had the bone collapsed. Histology of only one similar lesion is reported in the literature (McCallum et al. 1966). Necropsy material is considered, together with radiographs and bone scans of the same lesions taken four years earlier. Similar changes have been shown to occur in commercial divers. On the evidence of this case it becomes clear that radiography is limited in its use and that bone scans as an indicator of repair may be open to misinterpretation. There may be a place for operation before the onset of symptoms in these cases of aseptic bone necrosis

One concern about the fixation of HA-coated implants is the possible disintegration of the surface, with the migration of HA granules into the joint space, producing third-body wear. We report a study of six revisions of HA-coated polyethylene RM cups at 9 to 14 years after successful primary arthroplasty. In all six hips, we found HA granules embedded in the articulating surface of the polyethylene, with abrasive wear of the cup and the metal femoral head. The cup had loosened in four hips and three showed severe osteolysis of the proximal femur. Third-body wear due to HA particles from implant coating may produce severe clinical problems with few early warning signs. Further clinical, radiological and histological observations are needed to determine the possible incidence of this late complication in the various types of coating of a variety of substrates

1. The routes by which adult human articular cartilage can receive its nutrition is still a subject of controversy. 2. Microscopic examination of normal adult human femoral heads has revealed vascular channels which penetrate the subchondral plate and calcified cartilage. These channels bring the medullary soft tissue into contact with the articular cartilage. 3. A fluorescent dye migration technique was used to show that the observed vascular channels are pathways for dye from the medullary cavity to the articular cartilage. It is suggested that these pathways could also be routes by which articular cartilage receives part of its nutrition. 4. The nutritional mechanism in the mature rabbit and adult human femoral heads cannot be compared because histological studies revealed differences in their subchondral structures

Between 1990 and 1998 we saw 21 children with primary subacute haematogenous osteomyelitis. Pain, swelling and a limp had been present for two to 12 weeks with little functional impairment. Laboratory tests were non-contributory. The lesions were classified radiologically into metaphyseal, diaphyseal, epiphyseal and vertebral. There were 24 sites involved, with most (20) being in the tibia; 17 lesions were in the diaphysis, five in the metaphysis and two in the epiphysis. The diagnosis was confirmed histologically in all cases. Staphylococcus aureus was cultured in six patients. Healing occurred in all patients after treatment with antibiotics for six weeks and radiological improvement was seen after three to six months. Subacute osteomyelitis develops as a result of increased host resistance and decreased bacterial virulence. The radiological features can mimic various benign or malignant bone tumours and non-pyogenic infections. Histological confirmation is necessary to avoid a delay in diagnosis

We made a semiquantitative study of the comparative histology of pseudomembranes from 12 loose cemented ceramic-ceramic and 18 metal-polyethylene total hip replacements. We found no significant difference in cellular reaction between the two groups, but there was a major difference in the origin of the particulate debris. In the metal-polyethylene group, polyethylene of articular origin was predominant, while in the ceramic-ceramic group the cellular reaction appeared to be a response to zirconia ceramic particles used to opacify cement used for fixation. Isolation and characterisation of the debris showed that the zirconia particles formed the greatest proportion (76%) in ceramic-ceramic hips, while alumina debris of articular origin formed only 12%. Our study has indicated that aseptic loosening of ceramic cups is not due to a response to debris generated at the articular interface, but to mechanical factors which lead to fragmentation of the cement

We reviewed 166 adult patients on long-term haemodialysis, dividing them into three groups according to the presence and type of shoulder pain. The 24 patients in group A, with spontaneous pain related to a supine posture, had been under haemodialysis for significantly longer than the others, and had a much higher incidence of carpal tunnel syndrome. Open or arthroscopic resection of the coracoacromial ligament in 21 shoulders relieved pain during haemodialysis and night pain, and histological examination showed amyloid deposits and inflammatory-cell infiltration in the subacromial bursa in almost all cases, and in the tenosynovium of the bicipital groove in some. We conclude that one type of shoulder pain experienced by patients on long-term haemodialysis is caused by the subacromial impingement of amyloid deposits. This should be distinguished from other types of shoulder pain, because it can be relieved by resection of the coracoacromial ligament

We prepared a prosthesis for the replacement of the lumbar vertebrae of sheep, using apatite- and wollastonite-containing glass-ceramic. The material is stronger than human cortical bone and has the special feature of chemical bonding to bone. Ten sheep underwent replacement of L3 and L4 vertebrae, without bone grafting. The animals were killed at intervals from three months to 27 months after operation, and the interface between the prosthesis and bone was examined radiologically, histologically and crystallographically. Bone bonding with the prosthesis had occurred in half the implants. It took at least one year for bonding to be complete, but an apatite layer on the surface of the prosthesis was observed as early as three months after the operation, suggesting the possibility of much earlier bone bonding if more rigid fixation of the prosthesis had been provided

We report 60 benign bone tumours treated by resection and curettage followed by the implantation of calcium hydroxyapatite ceramic (CHA). After follow-up of six to 60 months (average 36), no patient had local recurrence of the tumour or any adverse effects from the implants. In almost all cases radiography showed that the CHA was well-incorporated into the host bone, with new bone formation in and around the CHA. Corrective remodelling of deformed bone and normal fracture healing suggested that there was normal bone turnover in the presence of the CHA. Histology of biopsies from seven patients showed bone ingrowth into the pore structure of CHA in the central zone of some defects by one year after implantation. CHA appears to be a useful substitute for bone graft in the treatment of some benign tumours

Aims

Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship.

The cavities left after resection of bone bridges for partial closure of growth plates in children have commonly been filled with free fat grafts. Such cavities have been seen to elongate and thus enlarge during growth after the operation, but the fate of the grafts has been unknown. Similar cavities, made in the tibiae of growing pigs were filled with autogenous fat and studied by radiography for periods of up to 9 1/2 months. These cavities elongated in a manner similar to those in the clinical cases, and histological section showed them to be filled with living adipose tissue. The volume of this tissue had continuously increased in parallel with the growth in length of the bone. The fate of the grafts used in children may be similar to that seen experimentally

We report a high rate of failure of the Ring polyethylene cementless cup caused largely by granulomatous osteolysis. We have reviewed 126 prostheses inserted from 1986 to 1992 at from 11 to 90 months after surgery. There was radiological evidence of osteolytic granulomas adjacent to the external surface of the cup in 32%, appearing on average at three years from operation. In a subgroup of 59 prostheses followed for at least four years the incidence of such changes was 54%. A total of 27 cups (22%) have required revision, 21 for granulomatous loosening at an average follow-up of five years. In the retrieved prostheses there was obvious polyethylene abrasion and histological examination confirmed the presence of polyethylene wear debris. We found no significant correlation of osteolysis with cup size, although smaller cups were predominant among those having revision

1. Pain at the front of the radial side of the wrist may be caused by various lesions of the tendon and sheath of the flexor carpi radialis tendon. 2. The diagnosis may be established by testing resisted movement at the wrist and by the effect of injecting local anaesthetic into the tendon sheath. 3. In women over the age of fifty the lesion is associated with osteoarthritis of the joint between the scaphoid and the trapezium. 4. Osteoarthritis of the joint between the scaphoid and the trapezium is found in about 25 per cent of women over the age of fifty. 5. If the pain is not relieved by simple conservative measures it can usually be cured by incision of the tendon sheath. 6. The histological changes in the tendon sheath are similar to those found in tenovaginitis of the abductor pollicis longus and tibialis posterior tendons