Aims

To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs).

We have studied the histological appearances of forty femoral heads with idiopathic avascular necrosis. The characteristic histopathological changes of recurrent necrosis were present in 83 per cent. Recurrent necrosis occurred widely after revascularisation had progressed as far as the subchondral zone. The aetiology of idiopathic avascular necrosis of the femoral head may be a chronic condition which produces repeated infarction. The deformation and incomplete revascularisation of the femoral head may be due to repeated episodes of infarction as well as to mechanical factors related to weight-bearing

Aims

The purpose of this study was to compare the clinical, radiological, and patient-reported outcome measures (PROMs) in the first 100 consecutive patients undergoing total hip arthroplasty (THA) via a direct superior approach (DSA) with a matched group of patients undergoing THA by the same surgeon, using a posterolateral approach (PLA).

Deformity after slipped upper femoral epiphysis (SUFE) can cause cam-type femoroacetabular impingement (FAI) and subsequent osteoarthritis (OA). However, there is little information regarding the radiological assessment and clinical consequences at long-term follow-up. We reviewed 36 patients (43 hips) previously treated by in situ fixation for SUFE with a mean follow-up of 37 years (21 to 50). Three observers measured the femoral head ratio (FHR), lateral femoral head ratio (LFHR), α-angle on anteroposterior (AP) and frog-leg lateral views, and anterior femoral head–neck offset ratio (OSR). A Harris hip score < 85 and/or radiologically diagnosed osteoarthritis (OA) was classified as a poor outcome. Patients with SUFE had significantly higher FHR, LFHR and α-angles and lower OSR than a control group of 22 subjects (35 hips) with radiologically normal hips. The interobserver agreement was less, with wider limits of agreement (LOA), in hips with previous SUFE than the control group. At long-term follow-up abnormal α-angles correlated with poor outcome, whereas FHR, LFHR and OSR did not. We conclude that persistent deformity with radiological cam FAI after SUFE is associated with poorer clinical and radiological long-term outcome. Although the radiological measurements had quite wide limits of agreement, they are useful for the diagnosis of post-slip deformities in clinical practice

1. Dissection of forty-four developing human hip joints has shown that while the embryonic acetabulum is a deeply set cavity which almost totally encloses the head it gradually becomes more shallow as birth approaches. During the same period the femoral head becomes less globular and at the end of foetal life is almost hemispherical. The cover afforded to the femoral head by the acetabulum also becomes decreased. 2. After birth these trends reverse: the acetabulum becomes deeper again and the femoral head more globular. This process continues throughout childhood. 3. The findings provide a possible explanation for the increased liability to dislocation of the infantile hip

Aims

To develop and validate patient-centred algorithms that estimate individual risk of death over the first year after elective joint arthroplasty surgery for osteoarthritis.

We analysed 54 alumina ceramic-on-ceramic bearings from total hip replacements retrieved at one centre after a mean duration of 3.5 years (0.2 to 10.6) in situ. These implants were obtained from 54 patients (16 men and 38 women) with a mean age of 67 years (33 to 88) who underwent revision for a variety of reasons. Posterior edge loading was found in the majority of these retrievals (32 out of 54). Anterosuperior edge loading occurred less often but produced a higher rate of wear. Stripe wear on the femoral heads had a median volumetric wear rate of 0.2 mm. 3. /year (0 to 7.2). The wear volume on the femoral heads corresponded to the width of edge wear on the matching liner. Anteversion of the acetabular component was found to be a more important determinant than inclination for wear in ceramic bearings. Posterior edge loading may be considered to be a normal occurrence in ceramic-on-ceramic bearings, with minimal clinical consequences. Edge loading should be defined as either anterosuperior or posterior, as each edge loading mechanism may result in different clinical implications

A clinical, radiological and histopathological study of femoral heads from 125 patients with fracture of the neck of the femur and from 30 cadavers was carried out to identify various risk factors. The findings showed that the Singh index was unreliable as a radiological indicator of the bone content of the femoral heads; that the bone content of the femoral head in patients sustaining a fracture of the femoral neck did not differ from that of the controls; that osteomalacia was not found in any of the heads examined; and that the distribution of trabecular microfractures did not support the hypothesis that fracture of the neck was the result of progressive fatigue. It was concluded that the single most important factor leading to fracture in this Australian population was injury caused by falls and that such injury was frequently associated with other disease processes

We have investigated the factors which affect the progression of osteoarthritis after rotational acetabular osteotomy (RAO). Between 1984 and 1998, we treated 60 dysplastic hips by RAO. The mean age at surgery was 31.6 years (13 to 51) and the mean period of follow-up was 4.6 years (2 to 9.5). The thickness of the articular cartilage on the weight-bearing area, pre- and postoperative acetabular cover, and the sphericity of the femoral head were used for radiological assessment. The osteoarthritis did not progress in 39 hips. Significant factors which affected the radiological grade included sphericity of the femoral head and the postoperative acetabular cover. The surgical approach and preoperative acetabular cover did not affect the progression of osteoarthritis. Patients were divided into two groups according to the surgical approach used, either conventional (23 hips) or modified (37 hips). Significant factors included the postoperative acetabular cover in the modified approach, and the sphericity of the femoral head in the conventional approach. It is critical that the postoperative cover is sufficient, especially when RAO is carried out using our modified technique

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

We biomechanically investigated whether the standard dynamic hip screw (DHS) or the DHS blade achieves better fixation in bone with regard to resistance to pushout, pullout and torsional stability. The experiments were undertaken in an artificial bone substrate in the form of polyurethane foam blocks with predefined mechanical properties. Pushout tests were also repeated in cadaveric femoral heads. The results showed that the DHS blade outperformed the DHS with regard to the two most important characteristics of implant fixation, namely resistance to pushout and rotational stability. We concluded that the DHS blade was the superior implant in this study

Seventeen patients, with an average age of nine years 11 months, underwent 18 Chiari osteotomies for the treatment of painful subluxation of the hips following Perthes' disease. The average follow-up period was four years three months. The 13 patients reviewed clinically all did well and none complained of pain or instability. The radiographs were examined in all 17 cases. The average centre-edge angle and percentage femoral head cover were definitely improved by the operation. No significant medical displacement of the femoral head was achieved. The clinical success may result from improved femoral head coverage and diminished eccentricity. Chiari's osteotomy is recommended for adolescent patients with painful subluxation of the hip as a consequence of Perthes' disease

In a prospective study we assessed the causes of mechanical failure in a series of 230 intertrochanteric femoral fractures which had been internally fixed with either a sliding hip screw or a Kuntscher Y-nail. The overall rate of mechanical failure was 16.5%; cutting-out of the implant from the femoral head was the cause in three-quarters of the instances. Implants placed posteriorly in the femoral head cut out more often (27%) than those placed centrally (7%). The cut-out rate was also determined by the quality of the fracture reduction, but age, walking ability and bone density (assessed by the Singh grade and metacarpal indices) had no significant influence. We conclude that these fractures should be reduced as accurately as possible and it is imperative that the implant is placed centrally within the femoral head

Aims

Iliopsoas pathology is a relatively uncommon cause of pain following total hip arthroplasty (THA), typically presenting with symptoms of groin pain on active flexion and/or extension of the hip. A variety of conservative and surgical treatment options have been reported. In this retrospective cohort study, we report the incidence of iliopsoas pathology and treatment outcomes.

We have investigated the effect of joint tamponade and of traction in extension on the oxygen and carbon dioxide tensions in the femoral head of the immature goat, using mass spectrometry. Tamponade of 75 mmHg caused the oxygen tension in the femoral head to drop from 48 +/- 4 mmHg to 29 +/- 3 mmHg. Traction in extension further decreased the oxygen tension. Both these changes were highly significant. The partial pressure of carbon dioxide increased, but to a lesser extent and only effusion together with traction gave a statistically significant effect. Our study showed that joint effusion can produce hypoxia in the bone as a result of impaired blood flow to the femoral head. The application of traction increases this haemodynamic effect

The results of 110 operations for the treatment of fractures through metastases in the femoral neck and intertrochanteric region have been studied. Of these, forty-four fractures were treated by internal fixation, forty-six by resection of the femoral head and neck, and twenty by prosthetic replacement. The following conclusions were reached. 1. Prosthetic replacement of the femoral head is a reliable procedure. 2. The long stem type of prosthesis has the advantages of greater stability and simultaneous fixation of the shaft. 3. Patients with diffuse metastatic disease of the ilium are not suitable for prosthetic replacement. These patients should be treated by resection of the femoral head and neck. 4. Resection is a less traumatic procedure and therefore useful in the palliative treatment of patients in poor general condition. 5. Internal fixation leads more often to complications and unfavourable results than do the other methods

In Norway total joint replacement after hip dysplasia is reported more commonly than in neighbouring countries, implying a higher prevalence of the condition. We report on the prevalence of radiological features associated with hip dysplasia in a population of 2081 19-year-old Norwegians. The radiological measurements used to define hip dysplasia were Wiberg’s centre-edge (CE) angle at thresholds of < 20° and < 25°, femoral head extrusion index <  75%, Sharp’s angle > 45°, an acetabular depth to width ratio < 250 and the sourcil shape assessed subjectively. The whole cohort underwent clinical examination of their range of hip movement, body mass index (BMI), and Beighton hypermobility score, and were asked to complete the EuroQol (EQ-5D) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The prevalence of hip dysplasia in the cohort varied from 1.7% to 20% depending on the radiological marker used. A Wiberg’s CE angle <  20° was seen in 3.3% of the cohort: 4.3% in women and 2.4% in men. We found no association between subjects with multiple radiological signs indicative of dysplasia and BMI, Beighton score, EQ-5D or WOMAC. Although there appears to be a high prevalence of hip dysplasia among 19-year-old Norwegians, this is dependent on the radiological parameters applied. Cite this article: Bone Joint J 2013;95-B:279–85

Seventy children who had suffered from Perthes' disease were reviewed clinically and radiologically three to eight years from the onset of the condition in order to determine retrospectively the most satisfactory method of assessing the prognosis and the correlation between the clinical and radiological result. In younger children the femoral head was more likely to be spherical at the conclusion of the pathological process but not necessarily of normal proportions nor normally covered by the acetabulum. The prognosis was significantly poorer for girls than for boys. Clinical factors were not an aid to prognosis in the individual cases, but overall there was a close correlation between the clinical and the radiological end-results. The most reliable radiological factors indicating the prognosis were the extent of uncovering of the femoral head, the Catterall grouping, the presence of calcification lateral to the outer limit of the acetabulum and lateral displacement of the femoral head, as measured by comparing the head to tear-drop distances on each side