We retrospectively reviewed 56 patients (71 hips) treated by total replacement for severe disability after pelvic irradiation. Symptoms were associated with various radiological lesions due to irradiation, including atraumatic femoral-neck fracture, osteonecrosis of the femoral head or of the acetabulum, and radiation osteitis of the whole pelvis. From 1970 to 1982 we used standard cemented components in 49 hips and had a high rate of acetabular loosening (52%) at a mean follow-up of 69 months. This was probably due to the mechanical insufficiency of irradiated periacetabular bone. From 1983 to 1990 we routinely used acetabular reinforcement rings. The rate of aseptic acetabular loosening in 22 hips at a mean follow-up of 40 months was 19%, but there were two septic loosenings emphasising the risk of infection in these patients. When total replacement is required for an irradiated hip, we recommend reinforcement of the acetabulum using a metallic ring, but there is still an increased risk of infection and in difficult cases such as severe acetabular destruction or soft-tissue or vascular injuries, a Girdlestone procedure may be indicated.

We measured the proximal migration of 265 acetabular cups over seven years and correlated the findings with clinical outcome and acetabular revision for aseptic loosening. Cups which eventually became aseptically loose were shown to migrate more rapidly than successful cups. The average proximal migration at two years postoperatively for four groups of cups showed a monotonic relationship to the acetabular revision rate for aseptic loosening at 6.5 years. We conclude that acetabular cups which develop aseptic loosening as evidenced by pain, revision or screw fracture show increased proximal migration by one year, and that the 'migration rate' at two years can be used to predict the acetabular revision rate from aseptic loosening at 6.5 years.

We report the preliminary findings of the use of roentgen stereophotogrammetric analysis to evaluate the early migration of five femoral components after revision for mechanical loosening using impacted cancellous allograft and cement. All hips were examined at one week, four to six months and one year after surgery. All the components subsided by 0.4 to 4.9 mm during the first year. In four hips the prosthetic head was displaced 1.1 to 6.9 mm posteriorly. Fixation of the femoral components was less secure than after primary arthroplasty but the incidence and magnitude of early migration were similar to those after revision with cement alone.

At a minimum of one year after operation, we studied 64 patients with 86 total hip arthroplasties (THA) by standard anteroposterior hip and pelvic radiographs and measurement of range of motion and of isometric abduction strength. The femoral offset correlated positively with the range of abduction (p = 0.046). Abduction strength correlated positively with both femoral offset (p = 0.0001) and the length of the abductor lever arm (p = 0.005). Using multiple regression, abduction strength correlated with height (p = 0.017), gender (p = 0.0005), range of flexion (p = 0.047) and the abductor lever arm (p = 0.060). Our findings suggest that greater femoral offset after THA allows both an increased range of abduction and greater abductor strength.

We performed a randomised trial on 37 hips (33 patients) with early-stage osteonecrosis (ON). After the initial clinical evaluation, including plain radiography and MRI, 18 hips were randomly assigned to a core-decompression group and 19 to a conservatively-treated group. All the patients were regularly followed up by clinical evaluation, plain radiography and MRI at intervals of three months. Hip pain was relieved in nine out of ten initially symptomatic hips in the core-decompression group but persisted in three out of four initially painful hips in the conservatively-treated group at the second assessment (p < 0.05). At a minimum follow-up of 24 months, 14 of the 18 core-decompressed hips (78%) and 15 of the 19 non-operated hips (79%) developed collapse of the femoral head. By survival analysis, there was no significant difference in the time to collapse between the two groups (log-rank test p = 0.79). Core decompression may be effective tin symptomatic relief, but is of no greater value than conservative management in preventing collapse in early osteonecrosis of the femoral head.

In a randomised trial comparing core decompression with conservative treatment we tested the hypothesis that the extent of necrosis at the initial MRI predicts the subsequent risk of collapse of the femoral head. After the initial clinical evaluation, including plain radiography and MRI, 37 hips with early-stage osteonecrosis (ON) in 33 patients were randomly assigned to a core-decompression group or a conservatively-treated group. All were followed regularly by clinical evaluation, plain radiography and MRI at intervals of three months. The extent of ON was estimated on the basis of abnormal signal intensity in the weight-bearing portion of the femoral head as determined from a combination of coronal and sagittal MRIs. The arc of the necrotic portion in the mid-coronal image (A) and that in the mid-sagittal image (B) were used to quantify the extent of necrosis by the formula: (A/180) x (B/180) x 100. There was a strong correlation between this index and the risk of collapse before and after adjustment for age, gender, stage and treatment group. We conclude that the extent of the necrotic portion ascertain by this method is a major predictor of future collapse. We propose a systematic method of determining the index of the necrotic portion which may be clinically useful in the management of early-stage ON of the femoral head.

We report 22 patients (19 women and three men) of mean age 20.8 years who had painful snapping sensations in the groin. Most were able to reproduce the click by extending the affected hip from a flexed, abducted and externally rotated position and most were tender in the adductor triangle. Plain radiographs and an arthrogram were normal. A clinical diagnosis of subluxation of the iliopsoas tendon was made. Conservative management failed in 14 patients, two of whom had bilateral pain. All 14 had surgical release of the iliopsoas tendon through a medial approach. At follow-up (mean 17 months) the click had resolved in ten hips, was occasional but painless in five and unchanged in one. The syndrome of a painful 'snapping' psoas may result in disproportionately disabling symptoms. It may be diagnosed on clinical grounds and effectively treated, when severe, by release of the iliopsoas tendon.

We used fluoroscopy to study the kinematics of the knee in 47 patients with total knee arthroplasty (TKA) and four control subjects with normal knees while performing a single-leg deep-knee bend. The videos were analysed using still photographs taken at 5 degrees increments of flexion. Femorotibial contact points, patellar ligament rotation, and patellar rotation were calculated from each image. Maximum weight-bearing flexion was determined for each knee. Compared with the control group, posterior-cruciate-retaining TKA did not reproduce normal knee kinematics in any case, but showed a starting point posterior to the tibial midline which translated anteriorly with flexion. The curves from successive knee bends could not be consistently reproduced. Under weight-bearing conditions, the maximum flexion for any PCR TKA was 98 degrees and several patients could not flex beyond 70 degrees.

We describe the results of conservative treatment for complete midsubstance tears of the anterior cruciate ligament (ACL) in 18 skeletally immature patients, followed for a minimum of 36 months. Six patients had an ACL reconstruction during the follow-up period and were assessed immediately before their operation. The average time from initial injury to evaluation was 51 months. All patients had symptoms when reviewed. The modified Lysholm knee score showed one excellent result, one good, eight fair, and eight poor with a mean score of 64.3. Only one patient had returned to her preinjury level of athletics. Secondary meniscal tears were confirmed in six patients, and three more had the clinical signs of a tear at follow-up. Radiological evidence of degenerative changes was found in 11 of the 18 patients. We conclude that the results of non-operative treatment for ACL injuries in this age group are poor and not acceptable.

We assessed arthroscopically 22 young athletes with an isolated acute posterior cruciate ligament (PCL) injury. Four had significant damage to the articular cartilage of the medial femorotibial compartment and were advised not to resume sports. Three underwent PCL reconstruction because of a reparable meniscal tear or instability. The other 15 were treated conservatively and resumed sport. At an average follow-up of 51 months, one had developed arthritic symptoms due to newly-developed severe chondral damage to the medial femoral condyle, but none of the other 14 had developed arthritic symptoms and most remained athletically active. Severe chondral damage should be seen at an early arthroscopy. Knees with an isolated injury to the PCL with concomitant articular damage may be successfully managed by conservative treatment.

We compared the strength of fixation of a biodegradable screw with that of two metal screws in a bone-patellar-tendon-bone (BPTB) graft in the bovine knee. We used 33 fresh BPTB specimens with a circular tibial bone plug of 9 mm in diameter which were anchored in a tibial metaphyseal bone tunnel with either an interference screw (n = 11), an AO cancellous screw (n = 11) or a fibrillated, self-reinforced biodegradable poly-L-lactide screw (n = 11). The mean force to failure (+/- SD) in the three groups was 1358 +/- 348 N, 1081 +/- 331 N and 1211 +/- 362 N, respectively. There was no significant difference in the groups with regard to the linear load or the elastic moduli of the fixation. We conclude that the biodegradable screw is as good as either of the two metal screws in the fixation of a BPTB graft in the bovine knee and can be recommended for ACL reconstruction using this type of graft.

We reviewed the results of the treatment of 30 tibial fractures with minor to severe bone loss in 29 patients by early soft-tissue and bony debridement followed by primary locked intramedullary nailing. Subsequent definitive closure was obtained within the first 48 hours usually with a soft-tissue flap, and followed by bone-grafting procedures which were delayed for six to eight weeks after the primary surgery. The time to fracture union and the eventual functional outcome were related to the severity and extent of bone loss. Twenty-nine fractures were soundly united at a mean of 53.4 weeks, with delayed amputation in only one patient. Poor functional outcome and the occurrence of complications were usually due to a departure from the standard protocol for primary management. We conclude that the protocol produces satisfactory results in the management of these difficult fractures, and that intramedullary nailing offers considerable practical advantages over other methods of primary bone stabilisation.

Between 1989 and 1994 we used a vascularised ipsilateral fibular graft in 24 patients with segmental tibial defects. We report 12 patients with a minimum follow-up of two years. The graft was either transposed medially or inverted on its vascular pedicle. Full weight-bearing was achieved at between four and seven months. We had few complications and consider that the use of this method is a valuable option in reconstruction of the tibia.

We randomised 50 patients with ankle fractures of Weber types B and C and a ruptured deltoid ligament treated by open reduction and internal fixation to two treatment groups to examine the influence of the repair of a ruptured deltoid ligament. No differences were found except for a longer duration of surgery in the repair group. Our findings suggest that a ruptured deltoid ligament can be left unexplored without any effect either on early mobilisation or on the long-term result.

We randomised 50 patients with extracapsular fractures of the femoral neck to receive either a bupivacaine femoral nerve block or systemic analgesia alone. A femoral nerve block was found to be an easy and effective procedure which significantly reduced perioperative analgesic requirements and postoperative morbidity.

A reduced retroversion angle of the humeral head may predispose to recurrent anterior shoulder dislocation and may also be a factor in persistent instability after soft-tissue repair. We performed rotational osteotomy of the proximal humerus in 20 patients with recurrent anterior shoulder dislocations (10 traumatic, 10 non-traumatic) and a decreased retroversion angle of the humeral head. The mean preoperative retroversion angle was 12 degrees, which was increased after surgery to a mean value of 32 degrees. All patients regained a normal range of shoulder motion and normal function within three months after surgery. At the five-year review all shoulders were stable, pain-free and had no radiological signs of osteoarthritis.

Patients suffering from generalised convulsions may dislocate their shoulders either anteriorly or posteriorly. Those with anterior dislocation are likely to have recurrent episodes because of secondary bony damage to the anterior rim of the glenoid and head of the humerus. In such patients there is high rate of failure of the standard soft-tissue stabilisation procedures. We have therefore devised a bone buttress operation in which autograft or allograft is secured to the deficient anterior glenoid and shaped to form an extension of its articular surface. We report our experience in 14 patients with grandmal epilepsy and recurrent anterior dislocation of the shoulder. After the bone buttress operation there were no further dislocations and all patients were satisfied despite a small restriction in their range of movement. We believe this to be the operation of choice for patients with this difficult problem.

Chronic rotator-cuff syndrome with impingement is satisfactorily treated by acromioplasty by both open and arthroscopic techniques, but the Neer operation with deltoid detachment requires a prolonged rehabilitation. Arthroscopic acromioplasty reduces recovery time but is a difficult procedure. McShane, Leinberry and Fenlin (1987) described a conservative open anterior technique with good results and shortened rehabilitation. A similar technique has been used in 25 patients with an average age of 46 years. After a mean follow-up of 24 months, 80% were very satisfied and none was dissatisfied. The average recovery times were 2.7 weeks for activities of daily living, 1.9 months for return to work and 3.7 months for all activities including overhead manual labour.

We reviewed 50 capitellocondylar elbow replacements performed by the lateral approach in 42 rheumatoid patients, at a median follow-up of three years. There were two major and 17 minor complications; 18 were early and one was late. Eight elbows required reoperation: soft-tissue surgery was performed in seven and prosthesis removal in one because of a deep infection. There were few problems of instability, but one patient sustained a traumatic dislocation which was stabilised after ligament reconstruction. Wound healing was delayed in two of five elbows which had been immobilised postoperatively for only five days, but healing was rapid in 45 elbows immobilised for 12 days. There was transient ulnar-nerve palsy postoperatively in 11 patients, with permanent palsy in three. All elbows were painfree or only slightly painful at follow-up; 49 were stable and 43 had a range of motion sufficient for activities of daily living. Radiological loosening of the humeral component was suspected in one asymptomatic elbow. The lateral approach is recommended for use with the capitellocondylar type of prosthesis in rheumatoid elbows with reasonably well-preserved bone stock.

Between 1969 and 1989, we performed posterior segmental instrumentation on 38 patients with thoracic Scheuermann's kyphosis. We used a dynamic system without sublaminar fixation, and a kyphosis of 50 degrees was the main indication for surgery. The mean initial angle was 68 degrees (50 to 100) and the mean final kyphosis was 43 degrees at five-year follow-up, with a mean final loss after surgery of 3.7 degrees. Reconstruction of the vertebral bodies, vertebral wedging and the anterior-body height ratio were observed even in skeletally mature patients. There were no medical complications. There were three cases of loss of correction by more than 10 degrees and one of rod fracture with pseudarthrosis. The role of non-operative treatment is evaluated and early surgical treatment is advocated.

We have reviewed 37 patients under the age of 18 years with lesions of the lumbar posterior end plate. All but one were active in sport, and most were seen because of low back pain. An abnormality was commonly found at the inferior rim of the body of L4 and at the superior rim of the sacrum. All adjacent intervertebral discs showed a decrease of signal intensity on the T2-weighted MRI. In 12 patients there was no interposed tissue at the posterior end-plate lesions. When disc material had migrated posteriorly none protruded beyond the posterior margin of the end plate, the dissociated portion of which was the main element compressing neural tissue. The posterior end-plate lesion should be regarded as a vertebral non-articular osteochondrosis.

We have studied 29 patients for at least five years after canal-expansive laminoplasty for cervical spondylotic myelopathy. The short- and long-term clinical results were compared, and successive radiographs assessed. The long-term clinical outcome was excellent in five patients, good in 12, fair in 11 and poor in one. The mean short- and long-term improvements were 54.4% and 48.5% but patients with focal kyphotic, kyphotic and S-shaped cervical spines did less well, as did those who had a decrease in the index of curvature of the cervical spine of more than 10 at follow-up. Canal-expansive laminoplasty with reconstitution of the posterior soft tissues may help to prevent postoperative malalignment and late neurological deterioration.

Tissue reaction to wear particles from metal implants may play a major role in the aseptic loosening of implants. We used electron microprobe elemental analysis to determine the chemical composition of wear particles embedded in the soft tissues around hip and knee implants from 11 patients at revision surgery for aseptic loosening. The implants were made of cobalt-chromium-molybdenum alloy or titanium-aluminium-vanadium alloy. Histological examination showed a widespread giant-cell reaction to the particles. Elemental analysis showed that the chemical composition of the particles was different from that of the implanted alloys: cobalt and titanium were reduced, often down to zero, whereas chromium and aluminium persisted. Our findings indicate that corrosion is continually changing the shape, size and chemical composition of the implanted alloy. This may alter the biochemical environment of the tissue surrounding an implant to favour bone resorption.

We have studied the ability of a range of antibiotics to penetrate intervertebral disc tissue in vitro, using a mouse disc model. Equilibrium concentrations of antibiotics incorporated into the entire disc were determined by bioassay using a microbial growth-inhibition method. Uptake was significantly higher with positively-charged aminoglycosides compared with negatively-charged penicillins and cephalosporins. Uncharged ciprofloxacin showed an intermediate degree of uptake. Our results support the hypothesis that electrostatic interaction between charged antibiotics and negatively-charged glycosaminoglycans in the disc is an important factor in antibiotic penetration, and may explain their differential uptake.

We tested prospectively for hepatitis C virus (HCV) in one orthopaedic surgeon's operative practice for one year. Of 425 consecutive patients, 19 (4.5%) were positive for HCV infection using a second-generation screening assay. The highest correlation with a positive test was the presence of tattoos and the second highest was intravenous drug abuse, but only after a second interview, since most patients did not report this risk on the initial questionnaire. Based on the criteria of the US Public Health Services algorithm, nine (47%) of the patients with a positive initial screening test or 2.2% of the 425 patients, had hepatitis C (both anti-HCV-positive and elevated alanine aminotransferase). In this group of nine, the presence of tattoos had the highest and intravenous drug abuse the second highest correlation, also after the second interview. There is no vaccine available for the prevention of HCV infection, and prophylactic immunoglobulin therapy has no proven value for primary exposure.