Socket migration and rotation in the Charnley total hip replacement were evaluated by roentgen stereophotogrammetric analysis in 23 patients with rheumatoid arthritis and 23 patients with osteoarthritis. The two groups were matched with regard to age and sex. The follow-up time was two years. In the rheumatoid patients socket migration was most prominent in the proximal direction and averaged 0.6 mm at 24 months as compared with 0.1 mm in the osteoarthritic group (p = 0.0003). Within the rheumatoid group a preoperative acetabular protrusion in five patients was associated with increased migration and rotation in all directions. The increased proximal migration in rheumatoid arthritis was consistent (p = 0.0009) even after the exclusion of the five protrusion cases. In the rheumatoid patients there was a correlation between low body-weight and proximal migration, but there was no such correlation in the osteoarthritic group. Our results suggest that socket fixation is less secure in patients with advanced inflammatory arthritis.

We allocated randomly 27 patients undergoing 28 primary uncemented total hip replacements (THR) to receive prosthetic components of similar design with either plasma-sprayed titanium alloy (Ti) coating (n = 13) or hydroxyapatite (HA) coating (n = 15). After some exclusions, 15 of the patients (15 THR; 7 with HA- and 8 with Ti-coating) were followed by roentgen stereophotogrammetric analysis at 3, 6 and 12 months to measure migration of the femoral component. Twenty-six of the patients (26 THR) were followed clinically and by conventional radiography. All the femoral components had migrated at 3 months. From 3 to 12 months, the migration of Ti-coated components continued whereas the HA-coated components had stabilised. At 12 months there was significantly less migration of the HA-coated components (p < 0.05). The maximum subsidence was 0.2 mm in both groups. The Harris hip score was equal in the two groups preoperatively but at follow-up it was better in the HA-coated group (p < 0.05) and visual analogue scale scores showed that they had less pain (p < 0.05).

We report complications from the use of modular components in 20 hip replacements in 18 patients. Fifteen complications (in 13 patients) were related to failure of a modular interface after operation. Femoral head detachment from its trunnion was seen in 6 hips from trauma (3), reduction of a dislocation (2), and normal activity (1). In one case the base of the trunnion fractured below an extra-long modular head. In seven other hips the modular polyethylene liner dislodged from its shell, causing severe damage to the shell in four cases with extensive metallosis. In one other hip an asymmetrical polyethylene liner rotated, resulting in impingement of the femoral component and recurrent dislocation. Operative errors were seen in five cases: implantation of a trial acetabular component in one; and mismatching between the size of the femoral head and the acetabular component in the others. Surgeons who use hip replacements with modular components should be aware of the potential for operative error and of the importance of early treatment for postoperative mechanical failure.

We report the histology of a femur retrieved 3.5 years after a cemented revision of a hip replacement in which impaction allografting had been used to fill two large cortical defects. The allograft chips had largely been replaced by viable cortical bone, and the interface between cement and tissue resembled that seen after primary cemented arthroplasty.

Survival analysis is a powerful tool for analysing the results of total joint replacement, but it has major drawbacks when the failure rates are very low. We have reviewed 35 recent survival analyses of joint replacements to assess the magnitude of these problems and make recommendations as to how they may be avoided.

Thirteen methods of hip scoring were applied in the postoperative assessment of 47 hip arthroplasties. Their results were found to be inconsistent, often giving contrary measures of success in the same patient. Ten variables were measured during the postoperative review of 256 hip arthroplasties and the data were submitted to multivariate factor analysis. This revealed that the ten variables could be reduced to three factors: pain, which correlated poorly with any other variable (Spearman correlation, r < 0.02); functional activity (distance walked, use of walking aids, stair climbing, use of public transport, limp, sitting and tying shoelaces); and deformity and range of movement. The range of hip flexion correlated closely with the sum of the arcs of movement and with Gade's index (Spearman correlation, r > 0.9). We suggest that, for outcome assessment, only three variables need to be recorded: pain, walking distance and range of hip flexion. The combination of these three measures into a single hip score is misleading.

Unlike hyaline cartilage, mandibular condylar cartilage can respond to injury by complete healing. We have used the reparative potential of mandibular cartilage to promote repair of defects in a hyaline cartilage joint surface. In 12 adult marmosets, articular fibrocartilage from the mandibular condyles was transplanted into full-thickness defects created in the femoral condyles. Additional defects acted as an ungrafted control group. The grafted defects showed good incorporation of the transplant with restoration of the articular surface within six months. Repair was by proliferation of the fibrocartilaginous graft and chondrogenesis of hyaline cartilage. The repopulating cells were distributed in a matrix of maturing collagen and sulphated glycosaminoglycans. Ungrafted control defects were only partly repaired with fibrous tissue, leaving articular deficiencies. We conclude that transplanted mandibular fibrocartilage can promote reconstitution of wounded hyaline cartilage joint surfaces in primates.

An episode of hypotension is common during cemented joint replacement, and has been associated with circulatory collapse and sudden death. We studied the mechanism of hypotension in two groups of six dogs after simulated bilateral cemented arthroplasty. In one group, with no lavage, the insertion of cement and prosthesis was followed by severe hypotension, elevated pulmonary artery pressure, decreased systemic vascular resistance and a 21% reduction in cardiac output. In the other group, pulsatile intramedullary lavage was performed before the simulated arthroplasties. Hypotension was less, and although systemic vascular resistance decreased, the cardiac output did not change. The severity of the hypotension, the decrease in cardiac output and an increase in prostaglandin metabolites were related to the magnitude of pulmonary fat embolism. Pulsatile lavage prevents much of this fat embolism, and hence the decrease in cardiac output. The relatively mild hypotension after lavage was secondary to transient vasodilation, which may accentuate the hypotension caused by the decreased cardiac output due to a large embolic fat load. We make recommendations for the prevention and management of hypotension during cemented arthroplasty.

We modelled a 'clean' surgical wound lightly contaminated with airborne bacteria, using agar, ovine muscle and ovine adipose tissue. This was used to assess the effect on bacteria of ultraviolet C light (UVC) 1200 mu W/cm2, hydrogen peroxide 3%, povidone-iodine 1% and 10%, chlorhexidine 0.05%, pulsed jet lavage with UVC and syringe and needle lavage with chlorhexidine 0.05%. All the agents were effective on agar, but mixing with blood or plasma neutralised hydrogen peroxide and povidone-iodine 1%. All the agents were less effective on tissue specimens than on agar, but were more effective on adipose tissue than on muscle. All the antiseptics except chlorhexidine were less effective when blood or plasma was added to muscle specimens before disinfection. UVC after pulsed jet lavage had an additive effect. Syringe and needle lavage with chlorhexidine 0.05% was the most effective method tested; it reduced colony counts by 99.8% and warrants clinical investigation.

Four cases of osteomyelitis of the pelvis are reported to demonstrate the several clinical syndromes to which this disease can give rise. Extensive surgical drainage and antibiotic treatment led to recovery in all cases.

This new blood test for infection is based on the phenomenon of leukergy in which white cells agglomerate in the peripheral blood of patients with inflammatory diseases. It was used in 26 patients with proven bone or joint infection and was positive in 25. The leukergy test was more accurate than the ESR, white cell count or blood culture. The percentage of cells agglomerated correlated with the clinical severity of the infection and the test detected reactivation of the septic process better than the other haematological tests. It is a rapid and inexpensive method which is useful in the diagnosis and management of bone and joint infections.

We reviewed the serial radiographs of 54 hips in 47 children treated by closed reduction for congenital dislocation of the hip and followed to at least 14 years of age, to determine the causes of acetabular dysplasia. We excluded hips with femoral head deformity or residual subluxation and compared the results with those from a control series of unaffected hips of patients with unilateral CDH. Acetabular development after the age of 11 or 12 years was significantly worse in Severin group III than in Severin group I hips on the affected side or Severin group III in unaffected control hips. One of the causes of acetabular dysplasia at maturity was found to be impairment of acetabular development after 11 or 12 years of age. This may be attributable to impaired secondary ossification in the acetabular rim. Our findings emphasise the importance of continuing the follow-up of patients treated for congenital dislocation of the hip until full skeletal maturity.

We report a review of 33 hips (32 patients) which had required repeat open reduction for congenital dislocation of the hip. They were followed up for a mean of 76 months (36 to 132). Factors predisposing to failure of the initial open reduction were simultaneous femoral or pelvic osteotomy, inadequate inferior capsular release, and inadequate capsulorrhaphy. Avascular necrosis had developed in more than half the hips, usually before the final open reduction. At review, 11 of the hips (one-third) were in Severin grade 3 or worse; five had significant symptoms and only ten were asymptomatic and radiographically normal. Once redisplacement has occurred after primary open reduction, attempts to reduce the head by closed means or by pelvic or femoral osteotomy are usually unsuccessful and a further open reduction is necessary.

The Chiari osteotomy and various shelf procedures are used to augment the weight-bearing area in dysplastic acetabula. The new articular surface derives by metaplasia from the acetabular rim and joint capsule, and is therefore of poorer quality than congruous hyaline cartilage. We reviewed 32 patients after augmentation procedures, using conventional radiographs and three-dimensional reconstruction from CT scans. We showed that Chiari osteotomy and shelf procedures generally achieve less than complete cover, especially over the posterolateral quadrant of the femoral head. Our results suggest that alternative methods which reorientate the whole of the acetabulum are the treatment of choice. Augmentation procedures remain as a salvage option when reorientation is inappropriate or the original hyaline cartilage surface is absent, as in subluxed joints with a secondary acetabulum. Computerised assessment is recommended before operation to assess existing cover and the possible extent of provision of new cover.

After late reduction of the hip in children with developmental dysplasia the acetabular contour slowly improves and it is difficult to know if and when acetabular reconstruction is required. We studied the radiographs of 19 patients with unilateral dislocated or subluxated hips which had been reduced between the ages of one and two years. Preoperatively, all the affected hips showed acetabular dysplasia. After reduction they steadily improved for three years by which time none was dysplastic as measured by the acetabular index. After the age of ten years, when assessed by the more sensitive centre-edge angle, two were found to be dysplastic. It was not possible to predict these from early radiographs. We conclude that the decision to reconstruct an acetabulum should not be taken until three years after reduction, and that a few hips which appear to be developing satisfactorily at that time will, nevertheless, become dysplastic.

We studied 1061 children with myelomeningocele, reviewing 3184 pelvic radiographs from 802 patients. Hip dislocation had occurred by the age of 11 years in 28% of children with a thoracic neurosegmental level, 30% of those with an L1/2 level, 36% of L3, 22% of L4, 7% of L5 and only 1% of those with sacral levels. Hip dislocation was not inevitable even when there was maximal muscle imbalance about the hip. The average hip flexion contracture in children aged 9 to 11 years was significantly greater in those with thoracic (22 degrees) and L1/2 (33 degrees) levels than in those with L4 (9 degrees), L5 (5 degrees) or sacral (4 degrees) levels. Our findings indicate that muscle imbalance is not a significant factor in the production of flexion deformity or dislocation of the hip; both are commonly seen in the absence of imbalance. The restoration of muscle balance should no longer be considered to be the principal aim of the management of the hip in children with myelomeningocele.

Radiography and CT and MRI scans of the lumbar spine were performed in young patients complaining of pain during extension of the lumbar spine but without neurological signs in the lower limbs. T1-weighted MR images in the coronal plane showed a hypo-intense area in the pars interarticularis before the detection of spondylolysis at that site by plain radiography or CT. We suggest that this may be useful in the early diagnosis of spondylolysis.

A randomised double-blind study was carried out on 60 patients undergoing elective lumbar discectomy. Patients in the study group (n = 30) received an injection of 10 ml of 0.5% bupivacaine into the wound; the control group (n = 30) received none. Postoperative pain was measured by a visual analogue pain scale and by the amount of morphine administered by a patient-controlled analgesia system. Patients in the study group had lower pain scores, used less morphine, waited longer until their first demand for analgesia and reported their postoperative pain to be less severe.

We report 17 patients who had grafting of the common peroneal nerve after traction injuries. Sixteen were reviewed at a median follow-up of 36 months. The nerve gap ranged from 7 to 20 cm. A functionally satisfactory result was achieved in six patients (37.5%), a fair result in six and a poor result in four. Seven patients had, in addition, a posterior tibialis tendon transfer; this improved the result in five. Grafting produced some satisfactory results even when the nerve gap was as long as 20 cm.

We used evoked spinal cord potentials (ESCP) for intraoperative diagnosis in 17 cases of traumatic brachial plexus palsy. Forty spinal nerves were directly stimulated during exploration of the brachial plexus and ESCP recorded from the cervical epidural space were compared with simultaneously observed somatosensory evoked potentials (SEP) and myelographic findings. Both SEP and ESCP could be evoked in 21 spinal nerves but ESCP were always more distinct and five to ten times greater in amplitude than SEP. In four nerves, ESCP but no SEP were produced, suggesting that there was continuity from the nerves to the spinal cord. ESCP were obtained from two spinal nerves which appeared to be abnormal on the myelogram. The results show that intraoperative electrodiagnosis by epidural ESCP recordings can provide useful information on the lesions of traumatic brachial plexus palsy.

A family history of shoulder instability in first-degree relatives was found in 24 of 100 patients who had been operated on for recurrent anterior shoulder instability. The patients with and without a family history were similar in respect of sex ratio, age at first dislocation and age at operation. The initial dislocation was non-traumatic in 22% of the patients with and in 13% of those without a positive family history (p = 0.3). Postoperative recurrence of instability was experienced by 34% of patients with and 33% of those without a family history (p = 0.9). In those with a family history, 13% of the recurrences were dislocations and 87% were subluxations. In patients without a family history 52% of the recurrences were dislocations and 48% were subluxations (p < 0.05). The contralateral shoulder was unstable in 50% of the patients with a family history and in 26% of those without (p = 0.03).

Thirty shoulders, in 20 patients, which had undergone core decompression for symptomatic avascular necrosis of the humeral head were reviewed 2 to 14 years later (average 5.6). Twenty-two showed good or excellent clinical results; the other eight shoulders had required arthroplasty. All 14 shoulders with stage I or II radiological changes (Ficat and Arlet 1980) at operation had good or excellent results. We advocate early core decompression for symptomatic avascular necrosis of the humeral head.

We made a randomised prospective comparison of the Dynamic Hip Screw and the Gamma locking nail for the internal fixation of 200 petrochanteric femoral fractures in elderly patients. There was less intraoperative blood loss and a lower rate of wound complications in the patients treated by the Gamma nail. They had, however, a high incidence of femoral shaft fracture which we relate in part to implant design. We do not recommend the use of the Gamma nail for these fractures.

We report the results of a randomised trial to determine the effects of skin traction on 252 patients awaiting surgery for fractures of the proximal femur. They were allocated randomly to be nursed free in bed or to receive Hamilton-Russell skin traction. No differences were found between the groups in terms of pain suffered, analgesia required, frequency of pressure sores or ease of operation. The application of skin traction to patients with fractures of the upper femur is time-consuming and we recommend therefore that its routine use should be discontinued.

We assessed 882 patients presenting with a proximal femoral fracture by a new mobility score and by a mental test score, to determine which was of the most value in forecasting mortality at one year. Both scores gave a highly significant prediction, but the mobility score had a greater predictive value and is easier to perform.

The torsion of both femora was evaluated in 110 patients who had been treated by intramedullary nailing for unilateral femoral shaft fractures. The anteversion (AV) angle was measured by ultrasound, using a tilted-transducer technique. True torsional deformity, defined as an AV difference of 15 degrees or more between sides was found in 21 patients, but only eight had complaints related to the deformity. Three patients had reoperations for troublesome external torsional deformities. Of 26 patients with AV differences of 10 degrees to 14 degrees, defined as possible torsional deformity, three had complaints, but none had serious problems. AV differences of up to 29 degrees were observed in symptom-free patients, and no patients with AV differences below 10 degrees had complaints. Static and dynamic nailing showed almost equal tendencies to lead to torsional deformity. We conclude that torsional deformities are usually established during the operation. Many patients tolerate abnormal torsion, but efforts should be made to reduce and stabilise the femoral shaft fracture with an AV difference of less than 15 degrees.

Nine patients with nonunited humeral shaft fractures were treated by open reduction and internal fixation with an intramedullary fibular bone graft and a compression plate. Fixation of the screws was enhanced by passing them through the fibula as well as the two humeral cortices (quadricortical fixation). Eight of the nine fractures united at an average of 3.5 months. Tests on cadaver bones showed that quadricortical fixation was as strong as methylmethacrylate augmentation and significantly better than bicortical fixation.

We conducted a retrospective analysis of 94 children with fractures of the distal third of the radius, with or without ulnar fractures, treated by primary closed reduction and plaster. The overall failure rate of 29% was due mainly to irreducibility, inability to maintain reduction and eventual limitation of forearm rotation. Age, sex and severity of angulation were not significant, but the direction of angulation and the degree of translation at either the radial or the ulnar fracture sites were significant risk factors. Translation of the radius was the single most reliable predictor of outcome (83% correct). The risk of failure in fractures with translation of the radius of more than half the diameter of the bone was 60%, compared with 8% for fractures with less translation.

Many methods of reconstruction for ACL deficiency have been described, but little is known about their biomechanical properties. We examined extra-articular (EA), intra-articular (IA) and combined (EA+IA) reconstructions in ten cadaver knees after the ACL had been ruptured by the performance of a rapid anterior drawer movement. Stability at each stage before and after rupture and reconstruction was tested by anterior drawer, Lachman, varus-valgus and tibial rotation tests. Both IA and IA+EA reconstructions restored normal stability, while EA reconstructions improved stability but did not restore it to normal. The addition of an EA procedure to an IA procedure made no difference to knee stability. We conclude that in cases of isolated ACL deficiency there is no biomechanical basis for EA reconstruction, either alone or in addition to an IA reconstruction.

We treated 39 knees with chronic deficiency of the anterior cruciate ligament by reconstruction using the ABC carbon and polyester prosthetic ligament; 31 (79.5%) were reviewed at an average follow-up of 34 months. There had been four complete failures requiring revision. The remaining 27 were studied in detail. On the Lysholm rating, only 11 knees (41%) had good results with a score of over 76. The mean anterior drawer movement was reduced from 7.6 mm before operation to 5.8 mm at review. The mean difference from the opposite uninjured knee was 3.9 mm before operation, 1 mm (in 21 patients) at mean follow-up of 7.4 months and 2.5 mm (in 27 patients) at 34 months, indicating progressive loss of effect. In our opinion the results are unsatisfactory: we do not recommend the use of this prosthetic ligament.

We describe the radiographic measurement of the angle of tilt of the patella and relate it to malalignment of the extensor mechanism. The tilt angle is defined as the angle subtended by a line joining the medial and lateral edges of the patella and the horizontal. The radiograph (Merchant type) is taken with the foot pointing up, the lower edge of the film parallel to the ground, and the knee at 30 degrees flexion. The mean tilt angle of a group of patients with signs and symptoms suggesting patellofemoral malalignment was 12 degrees (+/- 6 degrees); in a similar group of control subjects it was 2 degrees (+/- 2 degrees) (p < 0.01). Tilting of 5 degrees was taken to be the limit of normal. For the detection of patellar malalignment, the tilt angle was almost as specific as the congruence angle (92% v 99%) but more sensitive (85% v 25%) and more accurate (89% v 62%).

We compared the chevron and the Wilson metatarsal osteotomy for hallux valgus in a prospective randomised trial on 87 feet in 51 patients, reviewed at averages of 5.5 and 38 months after operation. The patients in the chevron group returned to work earlier and mobilised faster, but, at the later review, those in the Wilson group had better functional results and were more satisfied with the appearance of the foot. Correction of the hallux valgus angle was better maintained in patients in the Wilson group and they had a better range of motion at the metatarsophalangeal joint; fewer complained of metatarsalgia.

We performed arthrodesis of the ankle in eight patients by arthroscopic joint excision and fixation with crossed tibiotalar compression screws. Two patients had rheumatoid arthritis and six had post-traumatic osteoarthritis. None had a serious deformity of the ankle. Clinical ankylosis was achieved in all cases and there was radiological evidence of bone fusion in four.