Arthroplasty for Femoral Neck Fracture. Results of a nationwide implementation

Sammanfattning: Hip fractures are devastating for the individual and a substantial economic burden for society. The treatment for displaced femoral neck fracture is a choice between internal fixation, total hip arthroplasty and hemiarthroplasty. As a result of several randomized trials, the treatment has shifted in Sweden from mostly internal fixation towards arthroplasties. There have been concerns about long-term arthroplasty complications such as aseptic loosening and periprosthetic fracture. In addition to investigating this issue, the focus of this thesis was on identifying the optimal treatment methods for patients with this displaced femoral neck fractures, regarding choice of implant and surgical technique. In a 10-year follow-up of a randomized multicenter trial on 450 mentally lucid and relatively healthy patients above 70 years with displaced femoral neck fractures, patients treated with internal fixation had continuously higher rates of major complications compared to those treated with arthroplasty (46 % compared to 9 % at 10 years). Patients with successful healed fractures reported more pain and reduction of mobility at four months than those successfully treated with arthroplasty, and they never attained a better result than the latter. Those results indicate that there are no excess long-term complications after arthroplasty and refute the assumption that retaining the patient’s femoral head is beneficial. The Swedish Hip Arthroplasty Register records total hip arthroplasties since 1979 and hemiarthroplasties since 2005. All hospitals performing arthroplasty surgery in Sweden are participating and completeness of recordings is near 100 %. In a study based on data from the Swedish Hip Arthroplasty Register, patients with fracture-related total hip arthroplasty had a higher revision rate than those treated for other reasons (mainly osteoarthritis); 4.4 % compared to 2.9 % at 7 years. Revision rates were similar after acute fracture procedures and procedures performed secondary to failed internal fixation. Contrasting, hemiarthroplasties in the Swedish Hip Arthroplasty Register performed secondary to failed internal fixation were associated with a doubled risk of re-operation compared to those performed for acute fracture. Anterolateral surgical approach had a lower risk of total hip arthroplasty revision regardless of reason and hemiarthroplasty re-operation due to dislocation. Bipolar and uncemented hemiarthroplasties were risk factors for re-operation; the former due to dislocation, infection and periprosthetic fracture, the latter mainly due to periprosthetic fracture. Males had higher risk of total hip arthroplasty revision and hemiarthroplasty re-operation as well as higher risk of death within one year following the injury. Nationwide, the proportion of hemiarthroplasty procedures for acute fractures increased from 2005 through 2009 at the expense of those secondary to failed internal fixation. Use of monoblock type implants decreased to below 1 %. Modular implants increased generally, while in 2009 bipolar implants decreased in favor of unipolar. Uncemented implants and posterior surgical approach decreased. Assumedly, those changes are results of reports from clinical trials and the Swedish Hip Arthroplasty Register. In collaboration between the Swedish Hip Arthroplasty Register and the National Hip Fracture Register, all Swedish patients with displaced femoral neck fractures during 2009 received a mailed patient-reported outcomes questionnaire (79 % response rate). Patients above 70 years, with total hip arthroplasty reported less pain and were more satisfied than those treated with internal fixation or hemiarthroplasty at a median of 14 months after the fracture. Among patients below 70, those treated with total hip arthroplasty had less pain and were more satisfied than those with internal fixation. The results presented in this thesis support the use of arthroplasty as primary treatment for displaced femoral neck fractures and indicate that use of total hip arthroplasties could be increased even further. The higher risk of re-operation with bipolar implants implies that unipolar hemiarthroplasty may be preferable for the oldest. Finally, the results suggests that anterolateral surgical approach and cemented implants are preferable in fracture-related arthroplasty surgery.