Background: International registries with large, heterogeneous patient populations provide excellent research opportunities for studying factors that influence treatment outcomes after total hip arthroplasty. In the present study, we used a European multinational database to investigate whether there is an association between three functional variables (preoperative pain, mobility, and motion) and functional outcome.
Methods: We performed a retrospective cohort study on preoperative and follow-up clinical data that were prospectively entered into the International Documentation and Evaluation System European hip registry between 1967 and 2002. The inclusion criteria for this study were an age of more than twenty years, an underlying diagnosis of osteoarthritis, and a Charnley class-A functional designation at the time of surgery. A total of 12,925 patients (13,766 total hip arthroplasties) who met these criteria were entered into the analysis. Three functional variables (pain, mobility, and motion) that were assessed preoperatively were evaluated postoperatively at various follow-up examinations for a maximum of ten years.
Results: Six thousand four hundred and one patients could walk longer than ten minutes preoperatively; of these, 57.1% had a walking capacity of more than sixty minutes at the time of the most recent follow-up. In comparison, 6896 patients had a preoperative walking capacity of less than ten minutes and only 38.9% of these patients could walk more than sixty minutes at the time of the most recent follow-up. The difference was significant (p < 0.01). Similarly, 10,375 patients had a preoperative hip flexion range of >70°; of these, 74.7% had a flexion range of >90° at the time of the most recent follow-up. In comparison, 2793 patients had a preoperative hip flexion range of <70° and only 62.6% of these patients had a flexion range of >90° at the time of the most recent follow-up. The difference was also significant (p < 0.01). Lasting, complete, or almost complete pain relief was achieved by >80% of the patients following total hip arthroplasty regardless of their preoperative categorization of pain.
Conclusions: Patients with poor preoperative walking capacity and hip flexion are less likely to achieve an optimal outcome with regard to walking and motion. In contrast, there is no correlation between the preoperative pain level and pain alleviation, which is generally good and long-lasting after total hip arthroplasty.
Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.
Disclosure: The authors did not receive grants or outside funding in support of their research for or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.
A commentary is available with the electronic versions of this article, on our web site (www.jbjs.org) and on our quarterly CD-ROM (call our subscription department, at 781-449-9780, to order the CD-ROM).
Investigation performed at the Maurice E. Müller Research Center in Orthopedic Surgery, University of Bern, the Orthopedic Department at Inselspital University Hospital, Bern, and the Institute for Mathematical Statistics and Actuarial Science, University of Bern, Switzerland
- Copyright © 2007 by The Journal of Bone and Joint Surgery, Incorporated
Enter your JBJS login information below.
Please note that your username is the email address you provided when you registered.