The purpose of this study was to compare old and new techniques in hemiprosthesis for primary femoral neck fractures. We implemented a new technique for inserting the Charnley stem via the Hardinge approach. This included a distal centraliser, broaches and specific entry into the femoral canal via the piriformis fossa. We then compared stem alignment and cement mantle quality in old and new techniques. The sample comprised 42 patients (34 women) who had been operated on with the old technique and 49 patients (39 women) exposed to the modern technique.

Postoperative anteroposterior and true lateral radiographs were taken and evaluated for cementing quality, mantle thickness in the 14 Gruen zones and alignment of the femoral stem in both planes. On the Barrack classification there were nine grade-A with the new technique, compared to none with the old. There was one Grade-B with the old technique. With the new technique, cement mantle thickness and uniformity was better in Gruen zones 1 to 3, 5 to 10, and 12. Alignment as measured in the lateral plane by the mean antero-posterior angle was 5.2° with the old technique and 2.2° with the new (p =0.0001). In the frontal plane there was no difference.

It is hoped the advantages associated with this modern technique for inserting the Charnley stem will confer longer survival.

Malalignment and cement mantle quality have been implicated in loosening of the Charnley stem [2]. Several types of cemented prosthesis have adopted a modern insertion technique, which has not been available for the Charnley stem. We implemented a new technique for insertion of the Charnley stem via the Hardinge approach including a distal centralizer, broaches and specific entry into the femoral canal via the piriformisfossa, and compared it to the old technique for alignment of the stem and cement mantle quality.

Material and methods: Forty-two patients (34 women) operated with an old technique were compared with forty-nine patients (39 women) with the modern technique. All patients were operated through the Hardinge lateral approach, with primary hemiprosthesis by residents. Post-operative anteroposterior and true lateral radiographs were taken and evaluated for cementing quality [1], mantle thickness in the 14 Gruen zones, and alignment of the femoral stem in both planes.

Results: For the Barrack classification there was 9 grade A with the new technique, compared to none with the old (p< 0.0001, Table 1), and only 1 grade B with the old technique. The cement mantle thickness was more uniform (p< 0.0001), and the mean thickness was higher with the new technique for zones 1-3, 5-10 and 12 compared to the old technique. Alignment as measured in the lateral plane by the mean anteroposterior angle was 5.2° with the old technique, compared to 2.2° for the new technique (p=0.0001). In the frontal plane there was no difference.

Discussion: A modern insertion technique for the Charnley stem gave a much better cementing quality, better cement mantle uniformity and a thicker mantle in the critical zones, and more neutral alignment of the stem. As poor alignment and thin or absent cement mantle has been implicated in loosening the results should hopefully confer into longer survival.

Malalignment and cement mantle quality have been implicated in loosening of the Charnley stem [2]. We implemented a new technique for insertion of the Charnley stem (Hardinge approach) including a distal centralizer, broaches and speciþc entry into the femoral canal via the piriformis fossa, and compared it to the old technique for alignment of the stem and cement mantle quality.

Material and methods: Forty-two patients (old technique) were compared with forty-two patients operated with the modern technique. Residents operated all patients with primary hemiarthroplasty. Post-operative antero-posterior and true lateral radiographs were taken and evaluated for cementing quality [1], mantle thickness in the 14 Gruen zones, and alignment of the femoral stem.

Results: For the Barrack classiþcation there was 9 grade A with the new technique, compared to none with the old (p< 0.0001). The cement mantle was more uniform (p< 0.0001), and the mean thickness was higher with the new technique for zones 1–3, 5–10 and 12. Alignment in the lateral plane was 5.2û with the old technique, compared to 2.2û for the new technique (p=0.0001).

Discussion: A modern insertion technique for the Charnley stem gave a much better cementing quality, better cement mantle uniformity and a thicker mantle in the critical zones, and more neutral alignment of the stem. As poor alignment and thin or absent cement mantle has been implicated in loosening the results should hopefully confer into longer survival.