The joint surfaces of 60 hips obtained from the cadavers of elderly Asians were studied to determine the incidence, the grade and the distribution of both non-progressive (age-related) and progressive degenerative changes. It was observed that in the Asian population of 40 to 90 years of age, non-progressive changes were common, being seen in 66% of the acetabular specimens and 50% of the femoral heads. Only one specimen of the 60 showed unexplained progressive degenerative change. We conclude that primary osteoarthritis of the hip is rare in Asians

The pressure distribution between the cartilaginous surfaces in the human hip joint was measured using pressure-sensitive film. Five cadaveric hip joints (aged between 58 and 87 years) were measured at three positions and loads, representing three instants in the stance phase of the walking cycle. The pressure distribution was not uniform, indicating that the cartilage did not, to any great extent, distribute the applied load. The maximum pressures recorded were about 10 MN/m2. The anterosuperior surface of the cartilage was identified as an area of high pressure

The aim of this study was to evaluate whether universal (all neonates) or selective (neonates belonging to the risk groups) ultrasound screening of the hips should be recommended at birth. We carried out a prospective, randomised trial between 1988 and 1992, including all newborn infants at our hospital. A total of 15 529 infants was randomised to either clinical screening and ultrasound examination of all hips or clinical screening of all hips and ultrasound examination only of those at risk. The effect of the screening was assessed by the rate of late detection of congenital or developmental hip dysplasia in the two groups. During follow-up of between six and 11 years, only one late-detected hip dysplasia was seen in the universal group, compared with five in the subjective group, representing a rate of 0.13 and 0.65 per 1000, respectively. The difference in late detection between the two groups was not statistically significant (p = 0.22). When clinical screening is of high quality, as in our study, the effect of an additional ultrasound examination, measured as late-presenting hip dysplasia, is marginal. Under such circumstances, we consider that universal ultrasound screening is not necessary, but recommend selective ultrasound screening for neonates with abnormal or suspicious clinical findings and those with risk factors for hip dysplasia

We investigated 42 patients who were being considered for primary total hip arthroplasty (THA), but in whom it was uncertain whether the hip was the source of their pain. They were given an injection of local anaesthetic into the joint space. Of 33 patients who gained pain relief from their injection, 32 subsequently had successful THA. The remaining patient has not had surgery. The intra-articular injection of local anaesthetic is thus at least 96% sensitive. Of the nine patients who had no or only minimal pain relief from injection, one has had an unsuccessful THA, three have been successfully treated for other conditions and five have unresolved pain for which no organic basis has been established. We believe that the injection of local anaesthetic into the hip is a reliable test, with low morbidity. In difficult cases it will aid in the clarification of the cause of pain which possibly arises from the hip

Hip implant retrieval analysis is the most important source of insight into the performance of new materials and designs of hip arthroplasties. Even the most rigorous in vitro testing will not accurately simulate the behavior of implant materials and new designs of prosthetic arthroplasties. Retrieval analysis has revealed such factors as the effects of gamma-in-air sterilisation of polyethylene, fatigue failure mechanisms of polymethylmethacrylate bone cement, fretting corrosion of Morse taper junctions, third body wear effects of both hard-on-hard and hard-on-soft bearing couples, and the effects of impingement of components on the full spectrum of bearing surfaces, none of which was predicted by pre-implantation in vitro testing of these materials and combinations. The temporal sequence of the retrieval process is approximately six years from first implantation through retrieval analysis, laboratory investigation, and publication of results, and thus, in addition to rigorous clinical evaluation, represents the true development and insight cycle for new designs and materials

Neurogenic myositis ossificans is a disabling condition affecting the large joints of patients with severe post-traumatic impairment of the central nervous system. It can result in ankylosis of the joint and vascular or neural compression. Surgery may be hazardous with potential haemorrhage, neurovascular injury, iatrogenic fracture and osteochondral injury. We undertook pre-operative volumetric CT assessment of 45 ankylosed hips with neurogenic myositis ossificans which required surgery. Helical CT with intravenous contrast, combined with two- and three-dimensional surface reconstructions, was the only pre-operative imaging procedure. This gave good differentiation of the heterotopic bone from the adjacent vessels. We established that early surgery, within 24 months of injury, was neither complicated by peri-operative fracture nor by the early recurrence of neurogenic myositis ossificans. Surgical delay was associated with a loss of joint space and a greater degree of bone demineralisation. Enhanced volumetric CT is an excellent method for the pre-operative assessment of neurogenic myositis ossificans and correlates well with the operative findings

We describe 95 patients with previously treated congenital dislocation of the hip who underwent femoral osteotomy after the age of five years. The commonest indication for surgery was progressive uncovering and subluxation of the femoral head; other reasons were coxa vara, long leg dysplasia and persistent anteversion. Femoral osteotomy for uncovering of the femoral head (Severin Grade III) in this age group gave good results at maturity only when the acetabular angle was less than 25 degrees before operation. Femoral osteotomy alone was inadequate for true subluxation of the hip (Severin Grade IV)

Infection remains a significant and common complication after joint replacement and there is debate about which contributing factors are important. Few studies have investigated the effect of the operating time on infection. We collected data prospectively from 5277 hip and knee replacements which included the type of procedure, the operating time, the use of drains, the operating theatre, surgeon, age and gender. In a subgroup of 3449 knee replacements further analysis was carried out using the tourniquet time in place of the operating time. These variables were assessed by the use of generalised linear modelling against superficial, deep or joint-space post-operative infection as defined by the Australian Surgical-Site Infection criteria. The overall infection rate was 0.98%. In the replacement data set both male gender (z = 3.097, p = 0.00195) and prolonged operating time (z = 4.325, p < 0.001) were predictive of infection. In the knee subgroup male gender (z = 2.250, p = 0.02447), a longer tourniquet time (z = 2.867, p = 0.00414) and total knee replacement (versus unicompartmental knee replacement) (z = −2.052, p = 0.0420) were predictive of infection. These findings support the view that a prolonged operating time and male gender are associated with an increased incidence of infection. Steps to minimise intra-operative delay should be instigated, and care should be exercised when introducing measures which prolong the duration of joint replacement

Twenty-six patients with rheumatoid arthritis who had undergone bilateral replacement of the hip and knee were reviewed at a mean follow-up time of 51.6 months. A further operation was necessary in five patients due to complications of replacement of the knee, and seven patients still had significant pain in at least one replaced joint. There were no cases of infection due to operation. Seventeen of the patients still used walking aids, but one-third of these did so because of pain in joints that had not been replaced. Patients preferred painless total replacement of the hip to that of the knee

We describe a technique of ‘cross-hip distraction’ to reduce a dislocated hip with subsequent reconstruction of the joint for septic arthritis with extensive femoral osteomyelitis. A 27-year-old woman presented with a dislocated, collapsed femoral head and chronic osteomyelitis of the femur. Examination revealed a leg-length discrepancy of 7 cm and an irritable hip. A staged technique was used with primary clearance of osteomyelitis and secondary reconstruction of the hip. A cross-hip monolateral external fixator was used to establish normal anatomy followed by an arthroplasty. A good functional outcome was achieved. The use of cross-hip distraction avoids soft-tissue and nerve damage and achieved improved abductor function before arthroplasty

The exact measurement of femoral head cover is essential for an assessment of reduction of congenital dislocation of the hip. We have compared standard anteroposterior radiographs with computerised tomograms and thereby classified the shape of the acetabular roof into four types. We found that the CE angle of Wiberg is a more reliable measure of head cover when the lateral point of bony condensation of the roof is chosen as the reference point rather than the edge of the bone, where these two points do not overlap. We conclude that head cover can be more accurately determined in younger children with dysplastic hips by our 'refined' CE angle, than by the original method of Wiberg

There are many studies of long-term recovery from major joint arthroplasty, but little is known about the first days and weeks after operation. We measured function, emotional state and life evaluation before arthroplasty and at seven and 50 days after in a consecutive series of 40 hip and 23 knee replacements. Pain was relieved significantly at seven days after hip arthroplasty and even more at 50 days. In knee patients, pain relief was modest and was not apparent until 50 days. Functional ability was much improved by 50 days in hip patients, but hardly changed in knee patients. Positive mood and life satisfaction did not improve in either group. Our findings will help with more accurate information for patients before operation and also in judging the rate of recovery

The Articular Surface Replacement (ASR) hip resurfacing arthroplasty has a failure rate of 12.0% at five years, compared with 4.3% for the Birmingham Hip Resurfacing (BHR). We analysed 66 ASR and 64 BHR explanted metal-on-metal hip replacements with the aim of understanding their mechanisms of failure. We measured the linear wear rates of the acetabular and femoral components and analysed the clinical cause of failure, pre-revision blood metal ion levels and orientation of the acetabular component. There was no significant difference in metal ion levels (chromium, p = 0.82; cobalt, p = 0.40) or head wear rate (p = 0.14) between the two groups. The ASR had a significantly increased rate of wear of the acetabular component (p = 0.03) and a significantly increased occurrence of edge loading (p < 0.005), which can be attributed to differences in design between the ASR and BHR. The effects of differences in design on the in vivo wear rates are discussed: these may provide an explanation as to why the ASR is more sensitive to suboptimal positioning than the BHR

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

1. One hundred and forty-two cases of extra-articular arthrodesis of quiescent tuberculous hips with fibrous ankylosis have been reviewed. 2. The methods used were the ilio-femoral graft with and without osteotomy, and the ischio-femoral graft by the Brittain or Foley technique. 3. Success occurs more frequently when the grafting operation is combined with or followed by a femoral osteotomy. 4. It is suggested that this success is due largely to the increased immobilisation afforded by the osteotomy. 5. It appears that equally good results can be obtained with either an ilio-femoral or an ischio-femoral graft in these cases provided that an upper femoral osteotomy is also carried out, preferably at or soon after the grafting operation. 6. An upper femoral osteotomy will frequently convert an unsuccessful extra-articular hip graft into a successful one without further grafting

We have carried out a blind, prospective study of 50 consecutive patients undergoing replacement arthroplasty of the hip using two different approaches. Clinical assessment, including the Harris hip score and a modified Trendelenberg test, and electrophysiological examination of the abductor muscles of the hip were undertaken before and three months after surgery. We found that 48% of patients had preoperative evidence of chronic injury to the superior gluteal nerve. Perioperative injury to the nerve occurred commonly with both approaches to the hip. We did not find a significant correlation between injury to the superior gluteal nerve and clinical problems

Aims. We investigated whether blood metal ion levels could effectively identify patients with bilateral Birmingham Hip Resurfacing (BHR) implants who have adverse reactions to metal debris (ARMD). Patients and Methods. Metal ion levels in whole blood were measured in 185 patients with bilateral BHRs. Patients were divided into those with ARMD who either had undergone a revision for ARMD or had ARMD on imaging (n = 30), and those without ARMD (n = 155). Receiver operating characteristic analysis was used to determine the optimal thresholds of blood metal ion levels for identifying patients with ARMD. Results. The maximum level of cobalt or chromium ions in the blood was the parameter which produced the highest area under the curve (91.0%). The optimal threshold for distinguishing between patients with and without ARMD was 5.5 µg/l (83.3% sensitivity, 88.4% specificity, 58.1% positive and 96.5% negative predictive values). Similar results were obtained in a subgroup of 111 patients who all underwent cross-sectional imaging. Between 3.2% and 4.3% of patients with ARMD were missed if United Kingdom (7 µg/l) and United States (10 µg/l) authority thresholds were used respectively, compared with 2.7% if our implant specific threshold was used, though these differences did not reach statistical significance (p ≥ 0.248). Conclusion. Patients with bilateral BHRs who have blood metal ion levels below our implant specific threshold were at low-risk of having ARMD. Cite this article: Bone Joint J 2016;98-B:1455–62

We have studied the placement of three screws within the femoral head and the degree of angulation of the screws in 395 patients with displaced intracapsular fracture of the hip to see if either was related to the risk of failure of the fracture to unite. No relationship between nonunion of the fracture was found regarding the position of the screws on the anteroposterior radiograph. However, we found that a reduced spread of the screws on the lateral view was associated with an increased risk of nonunion of the fracture

Between 1999 and 2005, 10 264 patients who had undergone total hip replacement (THR) for subcapital fracture of the hip were compared with 76 520 in whom THR had been performed for other reasons. All the cases were identified through the Swedish Hip Arthroplasty Register. The THRs performed as primary treatment for fracture were also compared with those done after failure of internal fixation. After seven years the rate of revision was higher in THR after fracture (4.4% vs 2.9%). Dislocation and periprosthetic fracture were the most common causes of revision. The risk was higher in men than in women. The type of femoral component and the surgical approach influenced the risk. After correction for gender, type of component and the surgical approach the revision rates were similar in the primary and secondary fracture THR groups. Total hip replacement is therefore a safe method for both the primary and secondary management of fracture of the hip

In a consecutive series of 498 patients with 528 fractures of the femur treated by conventional interlocking intramedullary nailing, 14 fractures of the femoral neck (2.7%) occurred in 13 patients. The fracture of the hip was not apparent either before operation or on the immediate postoperative radiographs. It was diagnosed in the first two weeks after operation in three patients and after three months in the remainder. Age over 60 years at the time of the femoral fracture and female gender were significantly predictive of hip fracture on bivariate logistic regression analysis, but on multivariate analysis only the location of the original fracture in the proximal third of the femur (p = 0.0022, odds ratio = 6.96, 95% CI 2.01 to 24.14), low-energy transfer (p = 0.0264, odds ratio = 15.56, 95% CI 1.38 to 75.48) and the severity of osteopenia on radiographs (p = 0.0128, odds ratio = 7.55, 95% CI 1.54 to 37.07) were significant independent predictors of later fracture. Five of the 19 women aged over 60 years, who sustained an osteoporotic proximal diaphyseal fracture of the femur during a simple fall, subsequently developed a fracture of the neck. Eleven of the hip fractures were displaced and intracapsular and, in view of the advanced age of most of these patients, were usually treated by replacement arthroplasty. Reduction and internal fixation was used to treat the remaining three intertrochanteric fractures. Three patients developed complications requiring further surgery; five died within two years of their fracture