We report the results of cancellous femoral impaction grafting with cement in revision hip arthroplasty in all patients from one centre who had undergone surgery more than five years previously. A total of 32 surgeons undertook femoral impaction grafting in 207 patients (226 hips). There were no deaths attributable to the revision surgery; 33 patients with 35 functioning hips died with less than five years’ follow-up. One patient was lost to follow-up. Two hips (1%) developed early postoperative infection. Of the 12 stems which underwent a further surgical procedure for aseptic failure, ten were for femoral fracture and two for loosening.

Survivorship with any further femoral operation as the endpoint was 90.5% (confidence intervals, 82 to 98) and using femoral reoperation for symptomatic aseptic loosening as the endpoint, the survivorship was 99.1% (confidence intervals, 96 to 100) at 10 to 11 years. As a consequence of the experience in this series, we have modified our technique with an increased use of longer stems with impacted allograft. Long stems are indicated when the host bone around the tip of a short stem is compromised, in patients with major loss of bone stock, or when a femoral fracture occurs.

Controversy exists with regard to the thickness of cement mantles that are necessary around the femoral components of cemented total hip arthroplasties. Conventional teaching, based on bench-top or computor models and theoretical analyses, as well as post-mortem & follow-up studies, suggests that the cement mantle should be complete and not less than 2–3mm in thickness. Mantles that are less than this are held to be at risk from mechanical failure in the long term; if they are incomplete, focal lysis may occur and progress to aseptic loosening.

However, long term experience with a number of French cemented femoral components suggests that these conventions may be erroneous. These French femoral components include the Charnley-Kerboull (stainless steel) and the Ceraver Osteal (Ti6Al4V) stems, in both of which the underlying design principle is that the stem should completely fill the femoral canal, the cement then being used purely to fill the gaps. Such a design philosophy implies that the cement mantles will be very thin, and since both of these stems are straight and the femoral medullary canal is not, the mantles may not only be thin, but also in places incomplete.

Conventional teaching would suggest that any stem utilising mantles of this type would fail from a combination of focal lysis and cement fracture. Yet the long term results of both of these stems have been outstandingly good, with extremely low levels of aseptic loosening and endosteal lysis, irrespective of the bearing combinations being used. Both these stems have a surface finish of Ra < 0.1 microns. A third French design, the Fare stem, manufactured from Ti6Al4V and based on the same principles, was associated with bad results when manufactured with a rough (> 1.5 microns) surface, and appreciably better results after the surface roughness was changed to < 0.1 microns.

These findings, that constitute the ‘French Paradox’, have profound implications for the mechanical behaviour of cement in the femur and for the mechanisms that underlie stem failure from loosening.

We describe our experience with the implantation of 325 Exeter Universal hips. The fate of every implant was known. The procedures were undertaken by surgeons of widely differing experience. At follow-up at 12 years, survivorship with revision of the femoral component for aseptic loosening as the endpoint was 100% (95% CI 98 to 100). Survivorship with revision of the acetabular component for aseptic loosening as the endpoint was 96.86% (95% CI 93.1 to 98.9) and that with any reoperation as the endpoint 91.74% (95% CI 87.7 to 95.8). No adverse features have emerged as a consequence of the modular connection between the head and neck of the implant.

We have studied the influence of weight-bearing on the measurement of wear of the polyethylene acetabular component in total hip arthroplasty using two techniques. The measured vertical wear was significantly greater when radiographs were taken weight-bearing rather than with the patient supine (p = 0.001, method 1; p = 0.007, method 2). Calculations of rates of linear wear of the acetabular component were significantly underestimated (p < 0.05) when radiographs were taken supine. There are two reasons for this. First, a change in pelvic orientation when bearing weight ensures that the thinnest polyethylene is brought into relief, and secondly, the head of the femoral component assumes the position of maximal displacement along its wear path. Interpretation of previous studies on both linear and volumetric polyethylene wear in total hip arthroplasty should be reassessed in the light of these findings.

We investigated 42 patients who were being considered for primary total hip arthroplasty (THA), but in whom it was uncertain whether the hip was the source of their pain. They were given an injection of local anaesthetic into the joint space.

Of 33 patients who gained pain relief from their injection, 32 subsequently had successful THA. The remaining patient has not had surgery. The intra-articular injection of local anaesthetic is thus at least 96% sensitive. Of the nine patients who had no or only minimal pain relief from injection, one has had an unsuccessful THA, three have been successfully treated for other conditions and five have unresolved pain for which no organic basis has been established.

We believe that the injection of local anaesthetic into the hip is a reliable test, with low morbidity. In difficult cases it will aid in the clarification of the cause of pain which possibly arises from the hip.

We investigated 15 patients with painful hip arthroplasties using intra-articular injection of bupivicaine. Fourteen had pain relief and 13 of them were subsequently found to have loosening of one or both components. The relief of pain after total hip arthroplasty by intra-articular injection of bupivicaine indicates that a satisfactory result is probable after revision surgery with refixation of the components.

Bone necrosis adjacent to self-curing polymethylmethacrylate is a matter of accepted fact. Among the possible causes are mechanical and vascular damage from the preparation of the bone cavity, chemical damage from the monomer and free radicals in the cement dough, and thermal damage from the heat of polymerisation, occurring in this order. Consideration of the tissue reaction to this material, theoretical calculation of the heat output from polymerising acrylic and interface temperature proffiles, experimental observations of interface temperatures and maximal temperatures at polymerisation, together with clinical observations, all lead to the view that the bone necrosis is not a consequence of thermal damage, which is unlikely to be a cause of failure of prosthetic fixation. Temperatures recorded from within polymerising acrylic masses are related primarily to the amount of monomer polymerising and are of no clinical significance in the fixation of prostheses. Interface temperatures are related primarily to the surface area of the interface and the thermal characteristics of the cooler material.

1. The families of fifty patients with Dupuytren's disease have been investigated for its presence.

2. Familial occurrence has been found to be considerably higher than has been reported hitherto.

3. The findings suggest that genetic factors are of extreme importance in the pathogenesis of the common form of Dupuytren's disease.

4. A single gene, behaving as a Mendelian dominant, is likely to be involved.

5. Dupuytren's disease may not be a homogeneous condition from the pathogenic standpoint.