Abstract
Background
In Sweden approximately 6000 patients yearly sustain displaced femoral neck fractures. During the last decade there has been a shift towards more arthroplasties at the expense of internal fixation. In 2008 approximately 75% of the dislocated femoral neck fractures in Sweden were treated with arthroplasties. Those patients are typically elderly and frail and the vast majority of them receive hemiarthroplasties. In 2005 a national hemiarthroplasty registration was established as part of the Swedish Hip Arthroplasty Register (SHAR).
Material & Method
The SHAR aims to register all hemiarthroplasties performed in Sweden, including primary and salvage procedures. Surgical and patient details are recorded and re-operations are registered.
Results
21.346 hemiarthroplasties were recorded from 2005 through 2009. The most common diagnosis, acute fracture of the femoral neck, increased from 91.3 to 94.3 percent during this period. The most commonly used stems (i.e. the Lubinus SP II and the Exeter stems) accounted for 68.3 percent of the implants. In total 743 patients (3,6%) underwent additional surgery and the most common reason for this was dislocation. The strongest risk factors for re-operation and revision (Cox regression analysis) were hemiarthroplasty due to failed internal fixation (rr 2.1, 95%CI 1.7–2.7) and uncemented stem (2.0, CI 1.5–2.6). Even when only modern uncemented implants are analyzed (i.e. exclusion of Austin-Moore) we can still see an increased risk of any re-operation(1.8, CI 1.3–2.5) and re-operation due to periprosthetic fracture (3.8, CI 2.0–7.1). Bipolar hemiarthroplasty heads also increased the risk of re-operation, especially due to dislocation (1.4, CI 1.1–1.8). The most used bipolar head (Variocup) has no increased risk of re-operation compared to all other bipolar heads generally, but an increased risk of re-operation due to dislocation (1.7, CI 1.2–2.4). Anterolateral surgical approach (Gammer and Hardinge) decreased the risk of re-operation due to dislocation (0.63, CI 0,53-0.83). Other risk factors are male gender and age above 75 years. During the period the use of monoblock type implants decreased from 17.8 to 0.9 percent. Use of uncemented implants decreased from 10.4 percent in 2005 to 3.0 percent in 2009 and the number of procedures performed with anterolateral approach increased from 46.7 to 55.9 percent.
Conclusion
The SHAR have identified risk factors for re-operation and subsequently some important changes have been seen in choice of implant and fixation. We conclude that the results from the hemiarthroplasty registration have a large impact on the methods and implants chosen by the Swedish orthopaedic surgeons and therefore is an important tool in the continuing effort for improving the patient care.
