Aims

The aims of this study were to assess the exposure and preservation of the abductor mechanism during primary total hip arthroplasty (THA) using the posterior approach, and to evaluate gluteus maximus transfer to restore abductor function of chronically avulsed gluteus medius and minimus.

1. Prosthetic acetabular cups of the Charnley and McKee-Farrar designs were cemented into cadaveric pelves using different procedures for preparing the acetabulum. 2. The torsional moments needed to loosen these cups were measured. 3. The torsional moments so measured were found to be from about four to more than twenty times higher than the frictional moments measured in independent tests on the two designs of prosthesis. 4. It is argued that late looseness of the acetabular component after total hip replacement, in the absence of infection, seems most likely to be due to thermal damage to the bone occurring at the time of polymerisation of the cement, and to subsequent bone resorption. 5. Surgical preparation of the acetabulum should include removal of all the articular cartilage and cleaning of the acetabular fossa, but the drilling of additional holes in the floor of the acetabulum seems unimportant. 6. The possibility of fatigue fracture in bone as a factor contributing to late loosening is an argument in favour of metal-on-polyethylene prostheses with their lower frictional moments, although the importance of this factor cannot be estimated

We report a patient with bilateral uncemented total hip replacements in whom a deep infection on the second side may have been caused by a transient bacteraemia associated with a revision operation for deep infection on the first side. Both hips were successfully treated by one-stage exchange

We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years). Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular cup. The cup orientation and containment were interrelated; all vertically oriented cups were completely contained, whereas 25% of more horizontal cups were only partially contained. Completely contained cups had significantly lower incidences of complete cement-bone radiolucency (p = 0.02) and of wear (p = 0.09). Vertically oriented cups had a lower incidence of continuous radiolucency than neutrally oriented cups, but this was not statistically significant (p = 0.25). Our results confirm the importance of complete bony containment, and also indicate that it is better to accept vertical orientation and obtain full bony coverage than to have a more horizontal orientation with partial containment

We report a prospective study of 57 one-stage cemented revisions of total hip replacement for deep infection with an actively discharging sinus. The average follow-up was 7 years 4 months. Seven patients had required rerevisions, but at latest follow-up, infection was under control in 49 (86%). A discharging sinus is not, in itself, a contraindication to one-stage revision of a hip replacement

Vascular injuries after total hip arthroplasty are occasionally reported, but we have found only two cases of major arterial occlusion, and none at all involving the common femoral artery. We report two cases of occlusion of the common femoral artery after Charnley arthroplasties, one of which resulted in a below-knee amputation

We assessed 57 total hip arthroplasties in 34 adolescents with juvenile chronic arthritis using standard radiological techniques at an average of 4.7 years (20 months to 9 years) after surgery. The incidence of overall loosening was 24.6% (14 hips), but hips with a follow-up of more than five years had a loosening rate of 43.5% (10 hips; p < 0.01)

We have carried out a prospective, randomised study of prophylaxis for heterotopic ossification (HO) comparing indomethacin for 7 and 14 days, acetylsalicylic acid, and fractional (4 × 3 Gy) or single exposure of 5 or 7 Gy irradiation after operation. We initially had 723 patients (733 hip replacements), but after withdrawals there were 685 hips of which 18.4% developed HO; 14% were grade I, 2.9% grade II and 1.5% grade III of the Brooker classification. We compared the results between these groups with those of a matched control series and found that indomethacin, 2 × 50 mg for 7 and 14 days, and postoperative irradiation of 4 × 3 Gy or 1 × 7 Gy, significantly reduced the development of HO compared with the control group. Patients in the acetylsalicylic acid group and those with a single irradiation of 5 Gy after operation developed significantly more ossification than those in the indomethacin and other irradiation groups. We suggest the use of 2 × 50 mg of indomethacin with mucoprotection for seven days as prophylaxis against HO after total hip replacement for all patients. A single irradiation of 7 Gy is recommended for patients who have developed HO after previous operations or to whom administration of indomethacin is contraindicated

We report a prospective study of the factors associated with acute urinary retention after total hip replacement in 103 consecutive male patients. Eleven patients (10.7%) developed retention after operation. Of the factors investigated before operation three had predictive value: inability to pass urine into a bottle whilst lying in bed, urinary peak-flow rates indicative of obstruction, and a history of previous bladder outflow problems. This study suggests that patients showing one or more of these factors should be assessed and if necessary treated by a urologist before arthroplasty, so as to avoid the need for catheterisation, and the consequent risk of deep infection

The effect of Charnley cemented total hip replacement on venous blood flow in the legs and its relationship to deep-vein thrombosis were investigated in 413 patients. Blood flow was measured using strain-gauge plethysmography before operation, after surgery, and after discharge from hospital. There was a significant reduction in both venous capacitance and venous outflow, affecting both legs but greater in the operated leg. Venous flow remained significantly below preoperative levels in the operated leg six weeks after surgery. There was a highly significant correlation between the degree of reduction in blood flow and the development of postoperative deep-vein thrombosis. Venous stasis was shown to be a major factor in venous thrombogenesis

We measured bone mineral density (BMD) in the proximal femur by dual-energy X-ray absorptiometry (DEXA) in 20 patients after cemented total hip arthroplasty over a period of one year. We found a statistically significant reduction in periprosthetic BMD after six months on the medial side and on the lateral side adjacent to the mid and distal thirds of the prosthesis. At one year after operation there was a mean 6.7% reduction in BMD in the region of the calcar and a mean 5.3% increase in BMD in the femoral shaft distal to the tip of the implant. These changes reflect a pattern of reduced stress in the proximal femur and increased stress around the tip of the prosthesis. They support current concepts of bone remodelling in the proximal femur in response to prosthetic implantation

We compared patient satisfaction with surgeon satisfaction after total hip arthroplasty (THA) in a group of 193 patients (200 THAs, mean follow-up six years) using a visual analogue scale (VAS), and two objective and two subjective scoring systems. We also determined the survival rate with different endpoints. For the 121 hips available for clinical follow-up, we did not find a significant difference in satisfaction between patient and surgeon. In a subgroup with low patient satisfaction, the surgeon was more satisfied than the patient (p = 0.04). The correlation between the patient satisfaction VAS and the different subjective and objective scoring systems suggests that pain during activity is the most important factor for the patient. The survivorship at six years decreased from 96.6% to 83.7% if dissatisfaction (VAS > 20) was added to revision as an endpoint in the survival analysis. The patient satisfaction VAS provides additional information to evaluate the outcome of THA. We recommend the use of both subjective and objective scoring systems to evaluate the outcome of THA

We made a retrospective study of 55 primary total hip arthroplasties in 53 patients with a history of previous acetabular fracture. The mean follow-up was 7.5 years and the average age at fracture was 48.7 years. The incidence of radiographic femoral loosening (29.4%), symptomatic loosening (15.7%), and femoral revision (7.8%) were similar to those previously reported at 10 years for routine arthroplasties by Stauffer (1982). On the acetabular side, the incidence of radiographic loosening (52.9%), symptomatic loosening (27.5%), and revision (13.7%) were four to five times higher. We conclude that a history of prior acetabular fracture has a significant adverse impact on the long-term outcome of any subsequent total hip arthroplasty

In a prospective study of 14 patients undergoing total hip replacement we have used dual-energy X-ray absorptiometry (DEXA) to investigate remodelling of the bone around two different designs of cementless femoral prosthesis. The bone mineral density (BMD) was measured at 12-weekly intervals for a year. Eight patients (group A) had a stiff, collarless implant and six (group B) a flexible isoelastic implant. Patients in group A showed a decrease in BMD from 14 weeks after operation. By 12 months, the mean loss in BMD was 27%, both medially and laterally to the proximal part of the implant. Those in group B showed an overall increase in BMD which reached a mean of 12.6% on the lateral side of the distal portion of the implant. Our results support the current concepts of the effects of stem stiffness and flexibility on periprosthetic remodelling

Although about 200 000 cementless Zweymüller-Alloclassic total hip arthroplasties (THAs) were carried out worldwide in the last decade, the survival analysis of these prostheses was not available in the 2000 report of the Swedish national hip arthroplasty registry. We report a prospective survivorship analysis of 200 consecutive grit-blasted cementless Alloclassic primary THAs carried out since 1988. Using surgical, clinical and radiological endpoints for the stem and the threaded cup the ten-year survivorship was 91.5% for reoperation for any cause, 96.4% for hip pain (Merle d’Aubigné score < 5 points, clinical failure), 99.4% for definite aseptic loosening (radiological failure) and 99.3% for revision for aseptic loosening. Using the Swedish registry criteria of primary osteoarthritis and revision for aseptic loosening as the endpoint, the survival rate of 99.1% at ten years for the subgroup of 157 Alloclassic THAs in osteoarthritis compares favourably with that of the best modern cemented hip replacements reported in the Swedish arthroplasty registry

We describe the development and early clinical application of a ported, proximally-cemented titanium stem for cemented total hip arthroplasty. PMMA bone cement is delivered to the proximal femur under pressure after the stem has been positioned within the femoral canal. A mid-stem cement occluder contains the cement to the proximal stem only. A tapered body is incorporated in the design of the stem to reduce the structural stiffness and hence the degree of stress shielding within the reconstructed joint. We performed preclinical studies to measure the reduction in porosity and the pressurisation achieved. The porosity, as measured by the void percentage within the cured cement mantle, was reduced by more than 50% and there was an almost threefold increase in the mean pressure. Mechanical testing of the stem, using a three-point bend test, showed that the addition of cement injection ports on the anterior and posterior sides of the body of the proximal stem did not reduce its strength. Finite-element analysis indicated that, compared with a fully-cemented conventional stem, there was no change in the stresses within the cement mantle. In a series of 40 proximally-cemented stems followed for up to six years (mean 51 months) the mean Harris hip score was 91, and 85% of patients had good or excellent results. There was excellent pain relief, an increased level of activity and good patient satisfaction. One mechanical failure of the stem required revision at three years after implantation. The early results indicate that the clinical performance was equal to that achieved with other modern cemented stems. Radiological evaluation showed excellent results with no evidence of stress shielding. Further follow-up will determine if long-term stress shielding is reduced and if revision is made easier by the absence of a distal cement mantle

The Ring plastic-on-metal total hip replacement was introduced with the intention of combining the advantages of the cemented low-friction arthroplasty with those of a cementless system. Fourteen hundred and eighty-eight of these procedures have been reviewed. The results of a two to seven-year follow-up, and of a group which has completed at least five years are presented. There was an excellent clinical result in 93% of the whole series, and in 87% of the five-year group. When graded on the Charnley scale there was an average score of 5.86 for pain, 5.96 for function and 5.9 for range of movement, which compares favourably with cemented replacements. The deep infection rate was zero, and the revision rate 1.5% for the whole series. Erosive problems occurred with the smaller acetabular components and the reasons are discussed. The ease and success of exchange have been maintained

In 50 patients with non-infected total hip arthroplasties (THA), 233 C-reactive protein (CRP) values were obtained over a three-year period. Six of these 50 patients occasionally had CRP values of over 20 mg/l. The erythrocyte sedimentation rate (ESR) and CRP concentration were measured in 23 patients with deep infections of THA before revision. In 11 patients the infections were caused by coagulase-negative staphylococci. CRP exceeded 20 mg/l in 18 patients and the ESR was more than 30 mm/hr in 14. In only one infected patient were both CRP and ESR below these levels. All of 33 patients with non-septic loosening had CRP less than 20 mg/l and ESR less than 30 mm/hr before revision. C-reactive protein seems to be a valuable supplement to the ESR in the monitoring of infection after THA

Aims

In the 1990s, a bioactive bone cement (BABC) containing apatite-wollastonite glass-ceramic (AW-GC) powder and bisphenol-a-glycidyl methacrylate resin was developed at our hospital. In 1996, we used BABC to fix the acetabular component in primary total hip arthroplasty (THA) in 20 patients as part of a clinical trial. The purpose of this study was to investigate the long-term results of primary THA using BABC.