An excellent 5-year survival rate despite a high incidence of distal femoral cortical hypertrophy in a short hip stem. Issue 2 (March 2020)

• Record Type: Journal Article
• Authors: Thalmann, Caroline; Horn Lang, Tamara; Bereiter, Heinz; Clauss, Martin; Acklin, Yves P; Stoffel, Karl
• Is Part Of: Hip international. Volume 30:Issue 2(2020)
• Page Start: 152
• Page End: 159
• Publication Date: 2020-03
• Subjects: Bone remodelling -- cortical hypertrophy -- short stem -- survival analysis -- thigh pain -- total hip replacement; Hip joint -- Pathophysiology -- Periodicals; Hip joint -- Diseases -- Periodicals; Hip joint -- Surgery -- Periodicals; 617.581005
• DOI: 10.1177/1120700019834336
• Languages: English
• ISSNs: 1120-7000

Abstract

Background: Although reported results on short stems sound very promising, the occurrence of distal femoral cortical hypertrophy is often observed. The aim of the present study was to report 5-year survival data of a commercially available trochanter sparing short stem and investigate the clinical impact of distal femoral cortical hypertrophy on the outcome. Methods: 123 total hip arthroplasties were performed on 120 patients from April 2008 to May 2010 (mean age 62, range 29–89 years; 71 hips from male patients, 58%). Clinical and radiological data were collected preoperative, at 6 weeks, 1, 2, 3, and 5 years postoperative to assess the outcome. Radiographs taken immediately postoperative as well as 1 and 5 years postoperative were used to identify and assess cortical hypertrophy. Results: 1 stem had to be revised due to aseptic loosening, resulting in a Kaplan-Meier survival analysis with endpoint for stem revision of 99.2% (95% Confidence Interval 94.1–99.9) at 5 years. 96 radiological and 95 clinical follow-ups were analysed 5 years postoperative. 68 (71%) hips showed distal femoral cortical hypertrophy after 5 years. The average Harris Hip Score and Oxford Hip Score improved 33 (standard deviation (SD) 15.1, range 2–70), 18 (SD 12.1, range -10–43) points, respectively. Overall 16% of the patients reported thigh pain, unrelated to the presence of cortical hypertrophy. Discussion: This short stem shows an excellent 5-year survival rate and good clinical outcome despite a high incidence of cortical hypertrophy. However, the question of the mechanism of load transfer arises.