A. John Timperley

The long-term results of the original Exeter polished cemented femoral component: a follow-up report.

We present a long-term follow-up report of the results of the original Exeter polished cemented stems inserted between November 1970 and the end of 1975 at our institution by surgeons of widely differing experience using crude cementing techniques. The results of this series were reported in 1988 (Fowler et al. Orthopaedic Clinics of North America. 1988;19:477) and again in 1993 (Timperley et al. Journal of Bone and Joint Surgery. 1993;75-B:33). There have been no failures from aseptic femoral component loosening since the 1993 report. From the original series of 433 hips, there were, at the end of 2003, 26 living patients with 33 hips. Of the latter, there were 25 hips in 20 patients with their original femoral components still in situ. Twenty-eight (6.46%) hips from the original series have been lost to follow-up, although none since 1992. With the end point reoperation for aseptic stem loosening, the survivorship is 93.5% (95% confidence interval, 90.0%-97.0%). The reoperation rate for aseptic femoral component loosening is 3.23% into the 33rd year of follow-up.

Original ArticleThe Long-Term Results of the Original Exeter Polished Cemented Femoral Component: A Follow-up Report

We present a long-term follow-up report of the results of the original Exeter polished cemented stems inserted between November 1970 and the end of 1975 at our institution by surgeons of widely differing experience using crude cementing techniques. The results of this series were reported in 1988 (Fowler et al. Orthopaedic Clinics of North America. 1988;19:477) and again in 1993 (Timperley et al. Journal of Bone and Joint Surgery. 1993;75-B:33). There have been no failures from aseptic femoral component loosening since the 1993 report. From the original series of 433 hips, there were, at the end of 2003, 26 living patients with 33 hips. Of the latter, there were 25 hips in 20 patients with their original femoral components still in situ. Twenty-eight (6.46%) hips from the original series have been lost to follow-up, although none since 1992. With the end point reoperation for aseptic stem loosening, the survivorship is 93.5% (95% confidence interval, 90.0%-97.0%). The reoperation rate for aseptic femoral component loosening is 3.23% into the 33rd year of follow-up.

Femoral impaction grafting in revision total hip arthroplasty: a follow-up of 540 hips.

Between 1987 and 1999, 540 revision total hip arthroplasties in 487 patients were performed at our institution using the femoral impaction grafting technique with a cemented femoral stem. All patients were prospectively followed up for 2 to 15 years postoperatively with no loss to follow-up. A total of 494 hips remained successfully in situ at an average of 6.7 years. The 10-year survival rate was 98.0% (95% confidence interval, 96.2-99.8) with aseptic loosening as the end point and 84.2% (95% confidence interval, 78.5-89.9) for reoperation for any reason. Indication for surgery and the use of any kind of reinforcement significantly influenced outcome (P < .001). This is the largest known series of revision THA with femoral impaction grafting, and the results support continued use of this technique.

Mortality following hip arthroplasty--inappropriate use of National Joint Registry (NJR) data.

Mortality following hip arthroplasty is affected by a large number of confounding variables each of which must be considered to enable valid interpretation. Relevant variables available from the 2011 NJR data set were included in the Cox model. Mortality rates in hip arthroplasty patients were lower than in the age-matched population across all hip types. Age at surgery, ASA grade, diagnosis, gender, provider type, hip type and lead surgeon grade all had a significant effect on mortality. Schempers statistic showed that only 18.98% of the variation in mortality was explained by the variables available in the NJR data set. It is inappropriate to use NJR data to study an outcome affected by a multitude of confounding variables when these cannot be adequately accounted for in the available data set.

Posterior Longitudinal Split Osteotomy for Femoral Component Extraction in Revision Total Hip Arthroplasty

We present a technique of single posterior longitudinal split osteotomy. This technique allows the expansion of the proximal femur and easier extraction of uncemented femoral components. Since 1998 we have performed this osteotomy in 12 revision total hip arthroplasties in 11 patients who had either stable fibrous ingrowth or a small amount of bony ingrowth. All were revised to a cemented Exeter stem (Stryker Benoist Gerard, Caen, France). No patient required conversion from a longitudinal split to an extended trochanteric osteotomy. At mean follow-up of 48 months, there were significant improvements in both pain and function. There were no complications due to this technique. Mean in-cement taper engagement (subsidence) was 1.1 mm (range, 0-2 mm). Femoral impaction grafting did not adversely affect the cement mantle or increase in-cement taper engagement. With appropriate patient selection, this is a simple, reliable, and extensile technique to assist in the extraction of uncemented ongrowth femoral components whether hydroxyapatite-coated or not.

Indications for early hip revision surgery in the UK--a re-analysis of NJR data.

This study determined the rate and indication for revision between cemented, uncemented, hybrid and resurfacing groups from NJR (6th edition) data. Data validity was determined by interrogating for episodes of misclassification. We identified 6,034 (2.7%) misclassified episodes, containing 97 (4.3%) revisions. Kaplan-Meier revision rates at 3 years were 0.9% cemented, 1.9% for uncemented, 1.2% for hybrids and 3.0% for resurfacings (significant difference across all groups, p<0.001, with identical pattern in patients <55 years). Regression analysis indicated both prosthesis group and age significantly influenced failure (p<0.001). Revision for pain, aseptic loosening, and malalignment were highest in uncemented and resurfacing arthroplasty. Revision for dislocation was highest in uncemented hips (significant difference between groups, p<0.001). Feedback to the NJR on data misclassification has been made for future analysis.

Benefits of using modern cementing techniques in the acetabulum: the Rim Cutter.

Purpose. To compare radiological records of 90 consecutive patients who underwent cemented total hip arthroplasty (THA) with or without use of the Rim Cutter to prepare the acetabulum. Methods. The acetabulum of 45 patients was prepared using the Rim Cutter, whereas the device was not used in the other 45 patients. Postoperative radiographs were evaluated using a digital templating system to measure (1) the positions of the operated hips with respect to the normal, contralateral hips (the centre of rotation of the socket, the height of the centre of rotation from the teardrop, and lateralisation of the centre of rotation from the teardrop) and (2) the uniformity and width of the cement mantle in the 3 DeLee Charnley acetabular zones, and the number of radiolucencies in these zones. Results. The study group showed improved radiological parameters and were closer to the anatomic centre of rotation both vertically (1.5 vs. 3.7 mm, p<0.001) and horizontally (1.8 vs. 4.4 mm, p<0.001) and had consistently thicker and more uniform cement mantles (p<0.001). There were 2 radiolucent lines in the control group but none in the study group. Conclusion. The Rim Cutter resulted in more accurate placement of the centre of rotation of a cemented prosthetic socket, and produced a thicker, more congruent cement mantle with fewer radiolucent lines.

A modified cementing technique using BoneSource to augment fixation of the acetabulum in a sheep model.

Background and purpose Our aim was to assess in an animal model whether the use of HA paste at the cement-bone interface in the acetabulum improves fixation. We examined, in sheep, the effect of interposing a layer of hydroxyapatite cement around the periphery of a polyethylene socket prior to fixing it using polymethylmethacrylate (PMMA). Methods We performed a randomized study involving 22 sheep that had BoneSource hydroxyapatite material applied to the surface of the acetabulum before cementing a polyethylene cup at arthroplasty. We studied the gross radiographic appearance of the implant-bone interface and the histological appearance at the interface. Results There were more radiolucencies evident in the control group. Histologically, only sheep randomized into the BoneSource group exhibited a fully osseointegrated interface. Use of the hydroxyapatite material did not give any detrimental effects. In some cases, the material appeared to have been fully resorbed. When the material was evident in histological sections, it was incorporated into an osseointegrated interface. There was no giant cell reaction present. There was no evidence of migration of BoneSource to the articulation. Interpretation The application of HA material prior to cementation of a socket produced an improved interface. The technique may be useful in humans, to extend the longevity of the cemented implant by protecting the socket interface from the effect of hydrodynamic fluid flow and particulate debris.

The results of acetabular impaction grafting in 129 primary cemented total hip arthroplasties.

Between 1995 and 2003, 129 cemented primary THAs were performed using full acetabular impaction grafting to reconstruct acetabular deficiencies. These were classified as cavitary in 74 and segmental in 55 hips. Eighty-one patients were reviewed at mean 9.1 (6.2-14.3) years post-operatively. There were seven acetabular component revisions due to aseptic loosening, and a further 11 cases that had migrated >5mm or tilted >5° on radiological review - ten of which reported no symptoms. Kaplan-Meier analysis of revisions for aseptic loosening demonstrates 100% survival at nine years for cavitary defects compared to 82.6% for segmental defects. Our results suggest that the medium-term survival of this technique is excellent when used for purely cavitary defects but less predictable when used with large rim meshes in segmental defects.

Rationale for a Flanged Socket

In clinical practice, flanged cemented sockets have been shown to give better results than simple hemispherical cemented sockets. Laboratory studies have demonstrated their efficacy in increasing the cement injection pressure and thereby improving the cement-bone interface. The flange confers other benefits — it is helpful in attaining accurate socket orientation and the correct depth of insertion in order to establish an adequate, congruent cement mantle.