Complications and Functional Outcome of Displaced Femoral Neck Fractures Treated With Internal Fixation vs Total Hip Arthroplasty in Patients Younger Than 70 Years. A Randomized Controlled Double Blind Multi Center Trial.

Introduction:

Patients younger than 70 years with a displaced femoral neck are in serious conditions. The FNF (femoral neck fracture) is associated with low activity levels, hip pain and substantially reduced QoL (quality of life) . Individuals with high-energy fractures, caused by e.g. car accidents or falls from great heights, are in general healthy and often have normal bone quality in the femoral neck. In these cases, FNF rarely affects the femoral neck but rather the trochanteric area or the femoral shaft. Relatively young individuals with low-energy fractures tend to have additional morbidity or lower bone quality. The literature indicates that 5 % of all displaced FNFs are in patients aged 55 - 70 years. 3535 patients aged 55 - 70 years were registered in the Norwegian Arthroplasty Registry and in the Norwegian Hip Fracture Registry in the period 2005 - 2012. Little research and lack of consensus and guidance about appropriate treatment of these patients renders choice of treatment and the health economic aspect a great challenge. In this study we aim to answer if patients aged 55 - 70 years with displaced and low-energy FNF treated with a THA (total hip arthroplasty) leads to a better functional outcome than osteosynthesis (stabilization by use of hip pins) and can patient-related factors be identified that predispose for FNF?

Background:

Displaced low - energy FNF in patients aged 55 - 70 years is usually treated with internal fixation or implantation of a prosthesis. For patients older than 70 years, several randomized studies compare THA with other treatment options [1,2,3,4,5]; the studies have not found a higher mortality or morbidity for THA. Most orthopedics would probably recommend a closed reposition and osteosynthesis for patients younger than 60 years [6]. Screw fixation procedures will often be of shorter duration and less invasive, but the risk of needing a new operation because of a failure is higher than with prosthetic surgery. With a reoperation the risk of complications is higher than with the first operation. How this affects mortality, morbidity and functional outcome in this patient group is uncertain. Studies have shown both lower morbidity and earlier mortality than with prosthetic surgery [7,8,9]. On the other hand the reoperation rate because of failed osteosynthesis is 28 - 42% versus about 10% for THA; more recent studies show a reoperation rate for THA of 5% [1,2,3,4,5,10]. This is both of clinical and social economic importance. A study by McKinley and Robinson (2002) concluded that THA after failed osteosynthesis (screw fixation) was associated with a significantly higher prevalence of certain complications than THA as a first intervention [11]. Frihagen and collaborators reported about twice as many complications with prosthetic surgery after failed osteosynthesis (screw fixation) than with prosthetic surgery as the first intervention [12]. Young patients with low - energy FNF often have other diseases and conditions that may increase the risk of failed osteosynthesis. Reasons may be use of medication (steroids, epilepsy medication), alcoholism or other types of substance abuse and presence of risk factors for osteoporosis [13]. Several review articles and meta - analyses conclude that THA is associated with a lower rate of complications and a better functional outcome than other treatment alternatives [7,9,14,15]. Most orthopedic departments in Norway treat displaced FNFs in patients under 70 years of age with closed reduction and osteosynthesis or with different types of prosthetic surgery. Osteosynthesis is usually done with fluoroscopy on a transparent lighted stretch table and with some type of cannulated screws (Hip pins). Hemiprostheses or total hip prostheses are used for joint replacement surgery.

Goals for the project: