We have reviewed 54 hips in 46 patients from 2 to 14 years after a joint-preserving operation for idiopathic avascular necrosis of the femoral head. The choice between core decompression (17 hips), bone grafting (18), rotation osteotomy (15) or varus osteotomy (4) was determined by the stage and location of the area of necrosis. The overall success rate was unexpectedly low at 60%. Core decompression and bone grafting by our techniques gave poor long-term results, but those of rotation or varus osteotomies, performed with care for the correct indications, were better. The indications for each procedure are discussed: osteotomy is best when the area of necrosis is shallow and localised in the medial or anterior portion of the femoral head

Twenty-nine patients with avascular necrosis of the femoral head after injury have been treated by operation. Multiple drilling of the femoral head was performed, necrotic bone removed and a muscle-pedicle bone graft implanted into the head and neck of the femur. In 17 of the patients the necrosis was associated with an un-united femoral neck fracture, in 11 it occurred after the fracture had united, and one case followed reduction of a dislocated hip. The hips became painless soon after operation. The patients were young (average age 35 years), and full weight-bearing was not allowed for several months. The follow-up period ranged from 22 to 64 months. The results were excellent in 20 patients, good in five, fair in three and poor in one

We report a case of osteonecrosis of the femoral head in a young man who is a carrier of the prothrombin gene mutation. We suggest that an electrical injury to his lower limb may have triggered intravascular thrombosis as a result of this mutation with subsequent osteonecrosis of the femoral head. No case of osteonecrosis of the femoral head secondary to a distant electrical injury has previously been reported.

We present the long-term results of simple varus intertrochanteric osteotomy for osteonecrosis of the femoral head. We followed 26 hips in 20 patients, with a mean age at the time of surgery of 36 years, for a mean of 12.5 years. The mean varus angulation was 23°.

The outcome in 19 of the hips (73%) was good or excellent; seven (27%) had a fair or poor result, with four needing some form of prosthetic arthroplasty.

Simple varus intertrochanteric osteotomy is indicated, even if the extent of the capital infarct comprises more than 50% of the diameter of maximum radial distance from the circumference, provided that after operation the medial necrotic lesion measures less than two-thirds of the weight-bearing area, and the superolateral bone is normal.

We performed a prospective study using MRI to evaluate early necrosis of the femoral head in 48 patients receiving high-dose corticosteroids for the treatment of various autoimmune-related disorders. The mean interval from the initiation of corticosteroid therapy to the first MRI examination was 2 months (0.5 to 6). MRI was repeated, and the mean period of follow-up was 31 months (24 to 69).

Abnormalities were found on MRI in 31 hips (32%). The initial changes showed well-demarcated, band-like zones which were seen at a mean of 3.6 months after initiation of treatment with steroids. In 14 of these hips (45%) there was a spontaneous reduction in the size of the lesions about one year after treatment had started, but there was no further change in size with a longer follow-up.

Aims

The aim of this study was to evaluate the correlation between Salter’s criteria and Kalamchi’s classification of avascular necrosis in patients treated for developmental dysphasia of the hip (DDH).

We present the histological findings of bone retrieved from beneath the femoral components of failed metal-on-metal hip resurfacing arthroplasties. Of a total of 377 patients who underwent resurfacing arthroplasty, 13 required revision; for fracture of the femoral neck in eight, loosening of a component in three and for other reasons in two. None of these cases had shown histological evidence of osteonecrosis in the femoral bone at the time of the initial implantation.

Bone from the remnant of the femoral head showed changes of osteonecrosis in all but one case at revision. In two cases of fracture which occurred within a week of implantation, the changes were compatible with early necrosis of the edge of the fracture. In the remaining six fractures, there were changes of established osteonecrosis. In all but one of the non-fracture cases, patchy osteonecrosis was seen.

We conclude that histological evidence of osteonecrosis is a common finding in failed resurfaced hips. Given that osteonecrosis is extensive in resurfaced femoral heads which fail by fracture, it is likely to play a role in the causation of these fractures.

In fifty-two knees with spontaneous osteonecrosis the diagnosis was based on a subchondral transradiancy in the weight-bearing surface of the medial femoral condyle. Strontium-85 scintimetry showed a unique pattern, indicating a lively repair reaction by localised high values. Thirteen of fifteen knees followed between two and twenty-three years developed osteoarthritis. The prognosis was based on the size of the transradiancy and the focality of the lesion as determined by scintimetry. It is suggested that scintimetry permits differentiation between primary osteoarthritis and arthritis secondary to osteonecrosis.

A vascular necrosis (AVN) of the head of the femur is a potentially crippling disease which mainly affects young adults. Although treatment by exposure to hyperbaric oxygen (HBO) is reported as being beneficial, there has been no study of its use in treated compared with untreated patients. We selected 12 patients who suffered from Steinberg stage-I AVN of the head of the femur (four bilateral) whose lesions were 4 mm or more thick and/or 12.5 mm or more long on MRI. Daily HBO therapy was given for 100 days to each patient. All smaller stage-I lesions and more advanced stages of AVN were excluded. These size criteria were chosen in order to compare outcomes with an identical size of lesion in an untreated group described earlier. Overall, 81% of patients who received HBO therapy showed a return to normal on MRI as compared with 17% in the untreated group. We therefore conclude that hyperbaric oxygen is effective in the treatment of stage-I AVN of the head of the femur.

We studied the prognostic value of MRI in 32 radiographically normal, asymptomatic hips in 25 patients at risk of osteonecrosis from glucocorticoids or alcoholism. The early findings were band-like hypointense zones on spin-echo images. No operations were performed. Life-table survival curves showed that femoral heads in which the hypointense zone traversed the middle portion of the head were most at risk of subsequent segmental collapse.

The new Ionising Radiation (Medical Exposure) Regulations 2000 (IR (ME)ER) were implemented in January 2001. These regulations state that “the referrer must record in the patient’s notes that a radiograph was taken and what it showed”. As a result it is now incumbent upon the orthopaedic surgeon to document formally the findings of all requested radiographs. We present a case in which a left upper bronchial carcinoma was detected initially on a radiograph of the left shoulder. It highlights the importance of careful examination of the entire radiographic image and the documenting of the findings.

A 59-year-old woman with calcific tendinitis in her right shoulder underwent extracorporeal shock-wave lithotripsy. Three years and four months later she presented with osteonecrosis of the head of the right humerus. It is known that shock waves in patients with urological disorders can damage blood vessels. A possible reason for the development of osteonecrosis in this patient may have been damage to the blood supply of the head of the humerus.

The intra-osseous pressure, PO2, and PCO2 were measured in 32 hips (21 patients) which were painful but showed no severe degenerative changes. Pre-operative scintigraphy and radiography was performed in all patients. Thirteen hips showed early osteoarthritis, eight had early osteonecrosis, and 11 had no changes. Core biopsies were performed and the bone was examined histologically and graded for necrosis. Histologically, necrosis was present in 27 specimens. Scintigraphic findings did not correlate with the histological results but were more closely related to the radiographic findings. The intra-osseous pressure in hips with histological necrosis (mean 47 mmHg) was significantly higher than in hips without necrosis (mean 26 mmHg). The PO2 was lower in bone with histological necrosis (mean 44 mmHg) than in bone without (mean 71 mmHg). PO2 increased and intra-osseous pressure decreased after decompression. The results confirm that ischaemia plays a central role in the development of necrotic changes in bone. Histological necrosis was found in hips with radiographic signs of osteonecrosis and in those with osteoarthritis. Radiography, and scintigraphy are shown to be insensitive methods for differentiating between those disorders.