We investigated the wear characteristics and clinical performance of four different total hip joint articulations in 114 patients. Wear and migration was measured by roentgenstereophotogrammetric analysis at five years or at the last follow-up. The mean annual wear was 0.11 mm for a stainless steel/Enduron articulation, 0.34 mm for stainless steel/Hylamer cup, 0.17 mm for zirconium oxide ceramic/Enduron and 0.40 mm for zirconium oxide ceramic/Hylamer. The difference between the groups was significant (p < 0.008) except for stainless steel/Hylamer vs zirconium oxide ceramic/Hylamer (p = 0.26). At present, 12 patients have undergone a revision procedure, four at five years and eight thereafter. No patient who received a stainless steel/Enduron articulation at their primary replacement required revision. Conflicting results have been reported about the performance of the zirconium oxide ceramic femoral head, but our findings suggest that it should not be used with a polymethylmethacrylate acetabular component. Hylamer has already been withdrawn from the market

A simple method of measuring the degree of acetabular development in the radiograph of the adult pelvis is described and arguments for its validity are advanced. This measurement is referred to as the acetabular angle. The normal values for this angle are between 33 and 38 degrees. Angles below 32 degrees are uncommon and probably of no clinical significance, whereas angles from 39 to 42 degrees are in the upper limit of normality. An angle of 47 degrees is shown in a hip with congenital subluxation. The prognosis for hip joints with acetabular angles between 42 and 47 degrees is under investigation

1. Thirty-eight cases of tuberculosis of the greater trochanter have been reviewed. 2. Classification into bursal and osseous infections is discussed, and reasons have been given for our belief that either lesion may be the primary one. 3. An attempt has been made to assess available methods of treatment. In general, conservative measures are recommended for primary lesions, and surgery for recurrences. We have the impression that chemotherapy is of definite value. 4. The incidence of spread of tuberculosis to the hip joint is discussed. In this connection, reasons have been given for condemning excision of the trochanter

1. A method has been described whereby the disability of hip disease, bilateral or unilateral, can be graded, and the quality of result following arthroplasty assessed, on a scale of numerical values. 2. The grade expresses the condition of the entire patient, rather than that of the hip joint alone. 3. Certain clinical criteria and physical tests have been adopted as the bases for scoring. The calculation of the patient's total score has been weighted to emphasise mobility, and to provide a more critical measure of the success of arthroplasty. Subjective tests (aside from the patient's estimate of his pain) are avoided, to provide as objective and accurate a method of assessment as possible

1. Degenerative arthritis has been produced consistently in adult rabbits by the injection of the proteolytic plant enzyme papain into the hip joint. Arthritic changes were recognisable radiographically after six weeks. 2. A progression of changes occurred, from loss of acid mucopolysaccharide staining in the matrix, fibrillation, fissuring and erosion of articular cartilage with death of chondrocytes in the weight-bearing areas, to secondary bony changes of subchondral sclerosis, occasional cysts and osteophyte formation. 3. Synovial inflammation occurred with accumulation of cartilage and bone debris in the inferior capsule and later capsular thickening. 4. It is suggested that this arthritis is sufficiently similar to human osteoarthritis to be useful as a model for further studies of the pathogenesis of the disease and the effects of different methods of treatment

1. Twenty-two dislocations of the hip occurring in patients paralysed from an early age have been studied. All showed abnormal coxa valga. The coxa valga, which may gradually reach 180 degrees, precedes dislocation and makes it inevitable. The presence of unbalanced adductor power may hasten dislocation, but the latter can occur in complete flaccid paralysis. 2. The combination of structural instability of the hip joint and muscular weakness may make independent walking impossible, but restoration of stability gives considerable improvement in any remaining muscular power and may alter the patient's whole future. 3. A method of correcting the basic deformity of coxa valga by osteotomy is described and the results of nine operations are reviewed

Canadian Arthroplasty Society. The Canadian Arthroplasty Society’s experience with hip resurfacing arthroplasty: an analysis of 2773 hips. Bone Joint J 2013;95-B:1045-1051

Computed tomography was performed on 40 patients with recent hip trauma. Radiographs of 25 showed a fracture of the femoral neck with slight displacement; 24 of these had intra-articular fluid and 20 had a lipohaemarthrosis on the CT scan. In 15 patients, radiographs at the time of admission were normal but suspicion of fracture remained. A fracture was later verified in five patients, four of whom had lipohaemarthrosis on admission. In the remaining 10 patients no fracture could be detected; only one patient had a hip joint effusion but no free fat. Thus all 24 patients with lipohaemarthrosis had an intracapsular fracture of the hip. We suggest CT for patients with hip trauma and negative radiographs. The presence of a lipohaemarthrosis of the hip strongly suggests an intra-articular fracture of either the femoral neck or the acetabulum

Trendelenburg's test of function of the hip joint was first reported before radiology was available. At least four methods of performing it have since been described in the literature. We examined 50 normal subjects and 103 people with disorders affecting either the spine or the hip, in order to determine the different responses that occurred when they were asked to stand on one leg. This has enabled us to define a standard method of performing the Trendelenburg test, and to interpret the test as a method of assessing hip abductor function. The major pitfalls that result in misinterpretation, or false-positive responses, are pain, lack of cooperation from the patient, and impingement between the rib cage and the iliac crest. False-negative responses result from the patient using muscles above and below the pelvis, and from leaning beyond the hip on the standing side

We have compared the density of nerve fibres in the synovium in club foot with that of specimens obtained from the synovium of the hip at operations for developmental dysplasia. The study focused on the sensory neuropeptides substance P; calcitonin gene-related peptide; protein gene product 9.5, a general marker for mature peripheral nerve fibres; and growth associated protein 43, a neuronal marker for new or regenerating nerve fibres. In order to establish whether there might be any inherent difference we analysed the density of calcitonin gene-related peptide-positive nerve fibres in the hip and ankle joints in young rats. Semi-quantitative analysis showed a significant reduction in the number of sensory and mature nerve fibres in the synovium in club foot compared with the control hips. Calcitonin gene-related peptide (CGRP) positive fibres were reduced by 28%, substance P-positive fibres by 36% and protein gene product 9.5-positive fibres by 52% in club foot. The growth associated protein 43-positive fibres also seemed to be less in six samples of club foot. No difference in the density of CGRP-positive nerve fibres was observed in the synovium between ankle and hip joints in rats. The lack of sensory input may be responsible for the fibrosis and soft-tissue contractures associated with idiopathic club foot

Sixty-nine patients with congenital abnormality of the femur were reviewed. Their manifestation of femoral dysplasia ranged from an intact femur approximately 60 per cent of the length of the normal leg to a subtotal absence of the femur in which only the femoral condyles remained, often with a congenital fusion of the knee joint. Two groups were defined: Group I consisted of those with congenital hypoplastic femur in which the hip and knee could be made functional and where, in some patients at least, leg equalisation was possible; Group II consisted of those with true proximal focal femoral deficiency where the hip joint was never normal and the knee joint was always useless. The patients in each group were examined and evaluated with respect to clinical signs, surgical procedures performed, and prosthetic requirements and function. A protocol of treatment for both groups is suggested

1. Avascular necrosis of the bony epiphysis or necrosis of the articular cartilage of the hip joint–without bony necrosis–can occur after a slipped upper femoral epiphysis. 2. In avascular necrosis of the bony epiphysis the prognosis depends upon the degree of revascularisation that occurs and upon survival of the articular cartilage. The articular cartilage can survive and a good functioning hip result especially if aided by mobilisation without weight bearing. 3. The prognosis after necrosis of the articular cartilage is poor. This complication occurs more often when conservative treatment is used. 4. A certain number of hips will show poor results no matter what treatment is used. 5. Nutrition of the articular cartilage is probably by the synovial fluid. 6. Strong traction may damage the soft-tissue structure of the hip joint. 7. It is not advisable to perform an osteotomy soon after a slip of the epiphysis. It is better to wait until good function is assured in the joint

1. Fracture of the neck of the femur in childhood and its complications are discussed. 2. The high incidence of these complications is not generally appreciated–in this series of twenty-four patients only eight achieved normal hip joints. 3. The complications are due to the arrangement of the blood supply to the head and neck. Avascular necrosis is unavoidable in a high proportion, and is not directly related to any particular method of treatment. 4. Extreme care and gentleness in handling the injured limb will help to reduce the incidence of deformities; internal fixation is not suitable for the very young as it may predispose to necrosis or may damage the epiphysis. In older children it can be used with care. 5. Where growth is still taking place in the limb the retention of the angle between neck and shaft is most important, as this will prevent coxa vara and progressive shortening with the consequent unsightly Trendelenburg limp

Femoral lengthening has been associated with narrowing of the joint space at the hip. We have studied the joint space before lengthening in 20 patients with a short femur due to a femoral-shaft fracture (15) or distal femoral epiphyseal injury (5). Their mean age at injury was 16 years (3 to 27) and the mean shortening was 5.4 cm (1.1 to 14). We found that the hip joint space of the shortened femur was significantly narrower (p < 0.001) than that on the normal side, with a mean narrowing ratio of 15.5% (−5 to +43). The narrowing ratio was directly related to the period spent non-weight-bearing (p < 0.001), but not to the amount of femoral shortening. We have shown that the joint space of the hip in patients with post-traumatic femoral shortening was narrowed even before femoral lengthening had been started

The treatment of osteonecrosis of the femoral head (FHN) is controversial. It mainly occurs in young patients in whom total hip replacement is best avoided because of an increased risk of revision. The objective of this long-term follow-up study was to evaluate the outcome of intertrochanteric flexion osteotomy as a hip joint preserving operation for FHN. Over a 19-year period we carried out 70 intertrochanteric flexion osteotomies for FHN in 64 patients. The mean follow-up was 10.4 years (3.0 to 20.3). The overall mean Harris hip score increased from 51 points preoperatively to 71 points postoperatively. Six patients (9%) developed early postoperative complications. A total of 19 hips (27%) underwent total hip arthroplasty at a mean of 8.7 years after osteotomy. The five-year survival rate was 90%. Survival rates of hips in Ficat stage 2 were higher than those in stages 3 or 4. Hips with a preoperative necrotic angle of < 200° had a better survival probability than those with a necrotic angle > 200°. Our findings suggest that flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3 FHN, preferably with a necrotic angle of < 200°

Aims

This study compared multiple sclerosis (MS) patients who underwent primary total hip arthroplasty (THA) with a matched cohort. Specifically, we evaluated: 1) implant survivorship; 2) functional outcomes (modified Harris Hip Scores (mHHS), Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR), and modified Multiple Sclerosis Impact Scale (mMSIS) scores (with the MS cohort also evaluated based on the disease phenotype)); 3) physical therapy duration and return to function; 4) radiographic outcomes; and 5) complications.

Objectives

Legg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

1. A long-term follow-up of eighty-four patients with talipes equinovarus is reported. 2. A detailed examination was made to ascertain the nature of the residual deformity and assess the function of the deformed foot. 3. Radiographic technique in infants and adults is described. 4. Results showed that: 1) In many cases there was a dysplasia of the whole limb. 2) The dysplasia was no more marked in the patients treated in the early 1930's by multiple forceful under anaesthetic, than in the more recent patients treated by gentler means. 3) Nearly half the cases had only a false correction of the deformity in that the foot was "broken" at the talo-navicular level, leaving the heel in inversion, although the forefoot was plantigrade. 5. The posture of patients with laterally rotated hip joints is related to the fixed inverted heel. 6. Clinical assessment correlated with radiographic appearances shows clearly the near impossibility of a good foot resulting from a false correction

1. A patient wholly insensitive to painful stimuli as judged by psychical, physical, reflex and autonomic responses, showed multiple arthropathies. 2. Biopsy specimens of skin and periosteum from the region of the hip joint showed free nerve terminals similar in morphology to endings considered to subserve pain in normal subjects. The abnormality related to defective pain sensation therefore appears not to be due to a defect in the peripheral nerve endings for pain, but to be located more centrally in the nervous system. 3. In this patient, and in some patients with syringomyelia, arthropathy is associated with selective impairment of pain sensibility of the involved joints. It appears that tissue damage from the wear and tear of normal activity of a joint, if this damage is unheralded because of impairment of pain sense, can lead to arthropathy. 4. It is noted that further experimental evidence is still required to elucidate the role of various modalities of innervation in the maintenance of normal structure and function of joints

Aims

A clicky hip is a common referral for clinical and sonographic screening for developmental dysplasia of the hip (DDH). There is controversy regarding whether it represents a true risk factor for pathological DDH. Therefore a 20-year prospective, longitudinal, observational study was undertaken to assess the relationship between the presence of a neonatal clicky hip and pathological DDH.