Abstract
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.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
References
[1] Barrack, R.L., et al. J Bone Joint Surg [Br]74, 385–389 (1992). Google Scholar
[2] Garellick, G., et al. J Arthroplasty14, 414–25 (1999). Google Scholar
