Asphericity of the femoral head-neck junction is common in cam-type
femoroacetabular impingement (FAI) and usually quantified using
the alpha angle on radiographs or MRI. The aim of this study was
to determine the natural alpha angle in a large cohort of patients
by continuous circumferential analysis with CT. CT scans of 1312 femurs of 656 patients were analyzed in this
cross-sectional study. There were 362 men and 294 women. Their mean
age was 61.2 years (18 to 93). All scans had been performed for
reasons other than hip disease. Digital circumferential analysis
allowed continuous determination of the alpha angle around the entire
head-neck junction. All statistical tests were conducted two-sided;
a p-value <Â 0.05 was considered statistically significant.Aims
Methods
We studied the morphology of the haversian canals in the osteopenic cortical bone of the medial
Torsional instability of femoral components has not received much attention, and is difficult to detect in conventional radiographs. To test this we designed a system to apply a load in an anteroposterior direction to the head of a femoral component, implanted into a cadaveric femur. Rotation within the bone was measured, using a purpose built transducer, with and without preservation of the neck, with and without cement, and with longitudinal ridges but no cement. The results show that torsional instability may be a problem in uncemented replacement. Preservation of the
We measured the scattered radiation received by theatre staff, using high-sensitivity electronic personal dosimeters, during fixation of extracapsular fractures of the
One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the
We used 15 pairs of femora from fresh human cadavers to study the effects of the size and location of the entry hole for an intramedullary nail on the strength of the femur. Right femora were used as controls. Left femora in group 1 had a 10 mm entry hole in the 'ideal' location in the piriformis fossa. Group 2 had a 14 mm entry hole in the same position and group 3 had a 14 mm entry hole anterior to this on the superior aspect of the
We measured the range of rotation in both hips of 397 normal children and in the unaffected hip of 135 children with unilateral congenital dislocation of the hip. Both groups were assessed for generalised joint laxity. Joint laxity was more common in normal children with an internally centred arc of hip rotation than in normal children with a neutral or an externally rotated arc. The children with congenitally dislocated hips had significantly more joint laxity than did the control group and significantly more of them had an internally centred arc of hip rotation. We suggest that the lax joint capsule fails to mould away the neonatal anteversion of the
We studied the reliability of the Singh classification of trabecular bone structure in the proximal femur as a measure of osteoporosis, using kappa statistics. Radiographs of fractures of the
Our aim was to investigate the outcome of excision of osteochondromas. Between 1994 and 1998, 92 symptomatic osteochondromas in 86 patients were excised. There were 40 women and 46 men with a mean age of 20 years (3 to 62). Of these, 56 had a solitary osteochondroma and 30 had multiple hereditary tumours. The presenting symptoms were pain (79.1%), swelling (23.3%), reduced range of movement (19.8%), cosmetic abnormalities (17.4%), and bursitis (12.8%). The most common site (37.6%) was around the knee. Four patients had major complications (4.7%) including one intra-operative fracture of the
We present the results of 506 consecutive Howse hip arthroplasties with a minimum follow-up of 10 years. The mortality within one month of surgery was 0.79%. The early dislocation rate was 1.38%, two hips requiring revision. Nine hips developed deep sepsis (1.78%), eight of which required revision. At 10 years 42 hips (8.3%) had required revision, including 14 with aseptic acetabular loosening and 11 with femoral stem fractures. We feel that as judged by the dislocation rate and the need for subsequent revision, the Howse arthroplasty is an acceptable form of total hip replacement, particularly in the older patient and in those requiring total replacement for
It has been shown by mechanical analysis that by using cement to bond the stem of a femoral head prosthesis to bone two advantages are obtained when the conditions are compared with conventional methods. 1. "Fretting" between the implant and the living bone is eliminated. This source of persistent relative movement is probably the most important starting point for the progressive loosening of weight-bearing implants. 2. When cement is used the bond with the bone is exposed to stresses which are of an order three hundred times less than the shear strength of bone. The conventional prostheses expose the bond to compressive stresses which are near to the failure limits of the compressive strength of bone, especially in elderly patients with atrophic cortical bone in the
1 . The results of transplanting the greater trochanter in 225 "low-friction" arthroplasties of the hip have been examined. 2. Non-union occurred in an average of 7 per cent of cases. 3. When non-union occurred the results still showed improvement. 4. Four different methods of fixation were used, of which that using two wires, crossed in the horizontal and coronal planes, never failed to secure union. 5. Transplantation of the greater trochanter to the best position is only possible if the
1. Nine out of ten patients who undergo McMurray osteotomy may expect lasting relief of pain. Seventy-five per cent should have a satisfactory functional result. It is rare for a patient to be made worse. 2. Osteoarthritis of the hip and ununited fracture of the
Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum.Aims
Materials and Methods
From 1956 to 1965, congenital dislocation of the hip was treated in a standard manner in 191 cases. Reduction and plaster immobilisation was followed by a period in a Batchelor type plaster in full medial rotation.
We have studied the medium- and long-term effects of femoral intramedullary nailing in 34 children. There was a high incidence of abnormality at the proximal end of the femur, including coxa valga, arrest of growth of the greater trochanter and thinning of the
We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild osteogenesis imperfecta with an age- and sex-matched control group. The patients had only mild clinical symptoms but DEXA detected highly significant differences in BMD between them and the controls. The mean BMD in the children with osteogenesis imperfecta was 76.7% of normal in the lumbar spine (p <
0.001) and 71.2% of normal in the
A variety of surgical approaches are used for total hip arthroplasty (THA), all with reported advantages and disadvantages. A number of common complications can occur following THA regardless of the approach used. The purpose of this study was to compare five commonly used surgical approaches with respect to the incidence of surgery-related complications. The electronic medical records of all patients who underwent primary elective THA at a single large-volume arthroplasty centre, between 2011 and 2016, with at least two years of follow-up, were reviewed. After exclusion, 3574 consecutive patients were included in the study. There were 1571 men (44.0%) and 2003 women (56.0%). Their mean age and body mass index (BMI) was 63.0 years (Aims
Patients and Methods
We performed a prospective randomised controlled trial of the A-V Impulse System in 82 patients treated by hemiarthroplasty for subcapital fracture of the
We studied the migration of 58 cemented Hinek femoral components for total hip replacement,using roentgen stereophotogrammetric analysis over four years. The implants migrated faster during the first year than subsequently, and the pattern of migration in the second period was very different. During the first year they subsided, tilted into varus and internally rotated. After this there was slow distal migration with no change in orientation. None of the prostheses has yet failed. The early migration is probably caused by resorption of bone damaged by surgical trauma or the heat generated by the polymerisation of bone cement. Later migration may be due to creep in the bone cement or the surrounding fibrous membrane. The prosthesis which we studied allows the preservation of some of the