Rate of conversion to secondary arthroplasty after femoral neck fractures in 796 younger patients treated with internal fixation: a Swedish national register-based study.

BACKGROUND AND PURPOSE: In younger patients with a femoral neck fracture (FNF), internal fixation is the recommended treatment regardless of displacement. Healing complications are often treated with arthroplasty. We determined the rate of conversion to arthroplasty up to 5 years after fixation of either undisplaced FNFs (uFNFs) or displaced FNFs (dFNFs). PATIENTS AND METHODS: The study was based on prospectively collected data from the Swedish Fracture Register (SFR) and the Swedish Arthroplasty Register (SAR). FNFs in patients aged < 60 treated with parallel pins/screws or sliding hip screws (SHS) registered in SFR 2012-2018 were cross-referenced with conversions to arthroplasty registered in SAR until 2019. The cumulative conversion and mortality rates were determined by Kaplan-Meier analyses and patient- and surgery-dependent risk factors for conversion by Cox regression analyses. RESULTS: We included 407 uFNFs and 389 dFNFs (median age 52, 59% men). The 1-year conversion rate was 3% (95% CI 1-5) for uFNFs and 9% (CI 6-12) for dFNFs. Corresponding results at 5 years were 8% (CI 5-11) and 25% (CI 20-30). Besides a displaced fracture, age 50-59 was associated with an increased rate of conversion in uFNFs. This older group also had a higher mortality rate, compared with patients aged < 50. There was no sex difference for mortality. INTERPRETATION: Adults aged under 60 with uFNFs and dFNFs face an 8-25% risk, respectively, of conversion to arthroplasty within 5 years after internal fixation. This is new and pertinent information for surgeons as well as patients.

Hip fractures in the non-elderly-Who, why and whither?

Nonelderly hip fracture patients have gathered little scientific attention, and our understanding of the group may be biased by patient case-mix and lack of follow-up. Preconceptions may thwart adequate investigation of bone health and other comorbidities. This literature review focusses on who these patients between 20 and 60 years are, how to treat them and how to evaluate the outcome. 2-11% of the hip fractures occur in non-elderly, equally common in men and women. Every second to forth patient smoke, have chronic diseases, and abuse alcohol. Poor self-rated health, sleep disturbances, low cognitive function and education are associated with increased hip fracture risk in young adults. Bone health is poorly investigated, but literature suggest young patients to have lower bone mineral density regardless of trauma mechanism. Studies contradict on whether surgery within 8-12 h reduce the risk of avascular necrosis in femoral neck fractures (FNF). Based on rationality, surgery ought to be performed promptly, in order to reduce pain and permit rehabilitation. There is no convincing support from the existing literature to use open reduction. Good reduction is mandatory, preferably using a closed reduction technique. The failure rate following internal fixation of displaced FNF in younger patients can be as high as 59%. In some cases a displaced FNF is better treated with a primary arthroplasty; in case of rheumatoid arthritis or osteoarthritis for example. Complications after extracapsular fractures vary from 6 to 23%. The relatively few studies looking at functional outcome in non-elderly use a multitude of outcome measures, precluding comparisons. Many non-elderly patients seem not to fully recover. While some non-elderly hip fracture patients are healthy individuals sustaining high energy trauma, others have low-energy fractures and comorbidities including reduced bone strength (either as a primary or secondary condition). i.e. non-delaying medical optimization, proper surgical technique, bone health investigation and secondary fracture prevention is necessary. Younger hip fracture patients are at risk of permanent loss of function, and negative socioeconomic and psychological consequences. High-energy trauma does not exclude the presence of osteopenia. A hip fracture in adulthood and middle-age is very seldom caused by bad luck only!