Introduction and Aims: To study the survivorship and subsidence patterns of the first 433 Exeter polished, totally collarless, double tapered, cemented stems that were inserted between November 1970 and the end of 1975 by 16 different surgeons (13 of them in the training grades) utilising first generation cementing techniques.

Method: A survivorship study up to the 33rd year of follow-up, using the contingency table method, was performed for all 433 hips, the end-point being revision for aseptic stem loosening (including also a ‘worst case’ scenario). Stem subsidence in relation to the cement and the bone was measured in all survivors by a single observer on digitised films (magnified 200%) using the Orthochart™ software. Repeated measurements allowed the analysis of intra-observer errors. Stem subsidence, the grade of cementing, ‘calcar’ resorption, visible cement fractures, focal lysis and radiolucent lines at the interfaces were assessed.

Results: Of the 433 hips, 21 were revisions of previously failed hips. 21.7% of patients have had a re-operation of some sort, including 3.69% for stem fracture, 3.46% for neck fracture (all from a group of 95 stems with excessively machined necks), 9% for aseptic cup loosening, 3.46% for aseptic stem loosening, 1.84% for infection and 0.23% for recurrent dislocation). For the overall series, with revision for aseptic stem loosening as the end-point, the survivorship is 91.42% (95%CI: 70.82 to 100%). When all cases lost to follow-up (28 hips) are regarded as failures, survivorship is 82.9% (95%CI: 58.37 to 100%).

The average age at operation of the survivors was 57.6 years. No significant radiological subsidence between the cement and bone was found. Mean subsidence between the stem and the cement was 2.15mm, most occurring in the first five years and in all but one being less than four. The maximum was 18mm (grade D cementing). Cementing grades were B in 65%, C in 27%, D in 8%. Resorption of the neck (13%) was associated with excessive socket wear or cement left over the cut surface of the neck (the ‘pseudocollar’). Visible cement fractures were found in 14%, none associated with focal lysis, which was seen in 11%.

Conclusion: Although 21.7% of patients in this series of the first 433 Exeter hips to be inserted in Exeter needed a re-operation of some sort, the stem rarely required surgery for aseptic loosening and was associated with benign long-term x-ray appearances in spite of 1st generation cementing.

Introduction and aims: To study the survivorship and subsidence patterns of the first 433 Exeter stems inserted between 1970 and 1975 by 16 different surgeons utilising first generation cementing techniques.

Method: A survivorship study up to the 33rd year of follow-up was performed, the end-point being revision for aseptic stem loosening. Stem subsidence was measured in all survivors, as well as assessing the grade of cementing, ‘calcar’ resorption, visible cement fractures, focal lysis and radiolucent lines at the interfaces.

Results: Of the 433 hips, 21 were revisions of previously failed hips. 21.7% of patients have had a re-operation of some sort including 3.69% for stem fracture, 3.46% for neck fracture (all from a group of 95 stems with excessively machined necks), 9% for aseptic cup loosening, 3.46% for aseptic stem loosening, 1.84% for infection and 0.23% for recurrent dislocation). For the overall series, with revision for aseptic stem loosening as the end-point, the survivorship is 91.42% (95%CI: 70.82 to 100%). The average age at operation of the survivors was 57.6 years. No significant bone-cement subsidence was found. Mean stem-cement subsidence was 2.15mm, most occurring in the first 5 years and in all but 1 being less than 4mm. Cementing grades were B in 65%, C in 27%, D in 8%. Resorption of the neck (13%) was associated with excessive socket wear or cement left over the cut surface of the neck (the ‘pseudocollar’). Visible cement fractures were found in 14%, none associated with focal lysis, which was seen in 11%.

Conclusions: Although 21.7% of patients in this series of the first 433 Exeter hips to be inserted in Exeter needed a re-operation of some sort, the stem rarely required surgery for aseptic loosening and was associated with benign long-term X-Ray appearances in spite of 1st generation cementing.

Two hundred and seventeen consecutive patients (238 hips) underwent total hip arthroplasty using the St Michael’s stem and a non-porous screw ring cup. Patients were followed prospectively clinically using the St Michael’s hip score and radiographically. At an average of 11.9 years (10-13.5 years), 55 patients (59 hips) had died, 23 patients (23 hips) were lost to follow-up. The St Michael’s hip score improved from 13.4 pre-operatively to 21.7 (out of a possible 25) at the latest follow-up. Thirty-seven (24%) of the acetabular components have been revised for aseptic loosening and an additional seven components are radiographically loose. No femoral components have been revised. Using Engh’s criteria one femoral component is definitely loose and two femoral components have stable fibrous ingrowth. Significant stress shielding was noticed in 23 hips (17%) without clinical consequences. Minor osteolysis was seen in 13 hips most commonly around the proximal femur and has not caused symptoms. The St Michael’s stem with its large pore size madreporic surface has comparable results to other porous coated stems with smaller pore size.

The St Michael’s stem provided reliable ingrowth and fixation with an acceptable degree of stress shielding. The non-porous screw ring cup had a high failure rate.