Total hip replacement was performed in 27 hips of patients who had sickle cell anaemia with avascular necrosis of the femoral head. The disease was bilateral in 11 patients. Considerable medical problems were encountered although most of the patients had exchange transfusion before surgery (86%), which prevented postoperative sickle cell crises in all but two cases. At the primary operation hard sclerotic bone was seen in nine femora with complete obliteration of the femoral canal. There were four femoral fractures, three following perforation of the shaft due to this hard bone. There was a very high morbidity due to loosening in both cemented and uncemented prostheses. With a rate of 59% over a cumulative 5.5 year period, revision was being performed at an average of only 43 months. Surgeons should be aware of these problems

We randomised 24 patients before they had a cemented hemiarthroplasty for hip fracture to receive either thorough or minimal saline lavage of the femoral canal. We then determined the effect in each group on the thromboembolic and cardiopulmonary responses to the pressurised insertion of cement, using transoesophageal echocardiography to show the echogenic embolic response. We found a statistically significant reduction in both the duration of the response and the number of large emboli in patients who had had thorough lavage as compared with the control group with minimal lavage. There was also less disturbance of pulmonary function, as assessed by the change in end-tidal CO2 levels and oxygen saturation, in patients who had thorough lavage. Three patients had a significant fall in blood pressure during cement insertion; all had only minimal lavage. We consider that thorough lavage should be an essential part of the preparation of the proximal femur before cement insertion

We have compared the survival and radiological outcome at ten years after total hip replacement using two techniques for preparing the femoral canal. The same prosthesis was used throughout and all operations were performed by the same surgical team. In technique 1 the canal was over-reamed by 2 mm and in technique 2 it was reamed to the same size as the prosthesis. Technique 1 was performed on 92 patients and technique 2 on 97 patients. The survival at ten years was 97.2% (90.6 to 99.2) for technique 1 and 98.8% (92.9 to 99.8) for technique 2. Vertical migration was greater in technique 1 (1.8 mm versus 1.0 mm at five years; p = 0.36). There were significantly more lytic lesions and radiolucent lines at five years (p = 0.0061) with technique 1. We conclude that technique 2 is not worse and may produce better long- term results than current teaching suggests

In a prospective, controlled study, we measured the effect on cardiac output of the introduction of methylmethacrylate during hemiarthroplasty for displaced fractures of the femoral neck. We treated 20 elderly patients who were similar in age, height, weight and preoperative left ventricular function with either cemented or uncemented hemiarthroplasty. Using a transoesophageal Doppler probe, we measured cardiac output before incision and at six stages of the procedure: during the surgical approach, reaming and lavage of the femoral canal, the introduction of cement, the insertion of the prosthesis, and in reduction and closure. We found that before the cement was introduced, there was no difference in stroke volume or cardiac output (p > 0.25). Cementation produced a transient but significant reduction in cardiac output of 33% (p < 0.01) and a reduction in stroke volume of 44% (p < 0.02). The introduction of cement did not affect the heart rate or mean arterial pressure. There was no significant difference in cardiac function on insertion of the prosthesis. Standard non-invasive haemodynamic monitoring did not detect the cardiovascular changes which may account for the sudden deaths that sometimes occur during cemented hemiarthroplasty. The fall in stroke volume and cardiac output may be caused by embolism occurring during cementation, but there was no similar fall during reaming or insertion of the prosthesis

CT and advanced computer-aided design techniques offer the means for designing customised femoral stems. Our aim was to determine the Hounsfield (HU) value of the bone at the corticocancellous interface, as part of the criteria for the design algorithm. We obtained transverse CT images from eight human cadaver femora. The proximal femoral canal was rasped until contact with dense cortical bone was achieved. The femora were cut into several sections corresponding to the slice positions of the CT images. After obtaining a computerised image of the anatomical sections using a scanner, the inner cortical contour was outlined and transferred to the corresponding CT image. The pixels beneath this contour represent the CT density of the bone remaining after surgical rasping. Contours were generated automatically at nine HU levels from 300 to 1100 and the mean distance between the transferred contour and each of the HU-generated contours was computed. The contour generated along the 600-HU pixels was closest to the inner cortical contour of the rasped femur and therefore 600 HU seem to be the CT density of the corticocancellous interface in the proximal part of cadaver femora. Generally, femoral bone with a CT density beyond 600 HU is not removable by conventional reamers. Thus, we recommend the 600 HU threshold as one of several criteria for the design of custom femoral implants from CT data

Between 1985 and 1993, 146 patients (162 hips) had total hip replacement (THR) using a conservative uncemented femoral component. The mean age of the patients was 50.8 years and the mean follow-up was 6.2 years (2 to 13). One patient was lost to follow-up, one died within two years of surgery and one had a revision procedure after a fracture sustained in a road-traffic accident. For the remaining 159, Kaplan-Meier survival analysis was calculated for the incidence of revision because of mechanical loosening or osteolysis. Survival without mechanical loosening at both five and ten years was 98.2%. Survival without osteolysis was 99% at five and 91% at ten years. The Harris hip score improved from a mean of 66.3 before to 90.4 at follow-up. Of particular note is the lack of thigh pain in this group. Radiological analysis showed that 139 stems (88%) had no measurable subsidence, 8 (5%) had less than 2 mm and 12 (7%) had more than 2 mm. Two of the eight and one of the 12 were revised for mechanical loosening. Nine hips were revised for late loosening associated with osteolysis. No reaming of the femoral canal was associated with statistically significant less blood loss compared with a comparable control group of uncemented implants (p < 0.0001). Our study suggests that using a conservative femoral implant does not protect against wear debris but the reliable mechanical stability (98.2%) makes this an attractive design of implant particularly for young patients

We examined the roles of methylmethacrylate (MMA) monomer and cementing technique in the formation, and haemodynamic outcome, of pulmonary fat emboli. The preparation of the femoral canal and the cementing technique were studied in four groups of adult dogs as follows: control (no preparation); lavage; cement pressurisation; and cement pressurisation after lavage. We measured the intramedullary pressure, pulmonary artery pressure (PAP), pulmonary capillary wedge pressure and bilateral femoral vein levels of triglyceride, cholesterol and MMA monomer at rest and after reaming, lavage, and cementing. Femoral vein triglyceride and cholesterol levels did not vary significantly from resting levels despite significant elevations in intramedullary pressure with reaming, lavage and cementing (p = 0.001). PAP was seen to rise significantly with reaming (p = 0.0038), lavage (p = 0.0031), cementing (p = 0.0024) and cementing after lavage (p = 0.0028) while the pulmonary capillary wedge pressure remained unchanged. MMA monomer was detected in femoral vein samples when cement pressurisation was used. Intramedullary lavage before cementing had no significant effect on the MMA level. Haemodynamic evidence of pulmonary embolism was noted with reaming and intramedullary canal preparation, irrespective of the presence of MMA monomer. We found no relationship between MMA monomer level and intramedullary pressure, PAP or pulmonary capillary wedge pressure. Our findings suggest that the presence of MMA monomer in femoral venous blood has no effect on the formation of fat emboli or their pulmonary haemodynamic outcome during cemented hip arthroplasty

Aims

Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening.

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

Aims

The direct anterior approach (DAA) for total hip arthroplasty (THA) has potential advantages over other approaches and is most commonly performed with the patient in the supine position. We describe a technique for DAA THA with the patient in the lateral decubitus position and report the early clinical and radiological outcomes, the characteristics of the learning curve, and perioperative complications.

Aims

The aim of this study was to radiologically evaluate the quality of cement mantle and alignment achieved with a polished tapered cemented femoral stem inserted through the anterior approach and compared with the posterior approach.

Aims

We present the clinical and radiological results at a minimum follow-up of 20 years using a second-generation uncemented total hip arthroplasty (THA). These results are compared to our previously published results using a first-generation hip arthroplasty followed for 20 years.

Aims

Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre.

Aims

The Exeter V40 cemented polished tapered stem system has demonstrated excellent long-term outcomes. This paper presents a systematic review of the existing literature and reports on a large case series comparing implant fractures between the Exeter V40 series; 125 mm and conventional length stem systems.

Aims

Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Two-stage revision has traditionally been considered the gold standard of treatment for established infection, but increasing evidence is emerging in support of one-stage exchange for selected patients. The objective of this study was to determine the outcomes of single-stage revision TKA for PJI, with mid-term follow-up.

Aims

The aim of this prospective cohort study was to evaluate the early migration of the TriFit cementless proximally coated tapered femoral stem using radiostereometric analysis (RSA).

Aims

There are concerns regarding initial stability and early periprosthetic fractures in cementless hip arthroplasty using short stems. This study aimed to investigate stress on the cortical bone around the stem and micromotions between the stem and cortical bone according to femoral stem length and positioning.

Aims

Patients receiving cemented hemiarthroplasties after hip fracture have a significant risk of deep surgical site infection (SSI). Standard UK practice to minimize the risk of SSI includes the use of antibiotic-loaded bone cement with no consensus regarding type, dose, or antibiotic content of the cement. This is the protocol for a randomized clinical trial to investigate the clinical and cost-effectiveness of high dose dual antibiotic-loaded cement in comparison to low dose single antibiotic-loaded cement in patients 60 years and over receiving a cemented hemiarthroplasty for an intracapsular hip fracture.

Aims

Optimal exposure through the direct anterior approach (DAA) for total hip arthroplasty (THA) conducted on a regular operating theatre table is achieved with a standardized capsular releasing sequence in which the anterior capsule can be preserved or resected. We hypothesized that clinical outcomes and implant positioning would not be different in case a capsular sparing (CS) technique would be compared to capsular resection (CR).

Aims

The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach.