Figure 1. Image prompt: AP view of the pelvis and left hip. Authors’ own images.
A 70-year-old male presents with left hip pain and inability to ambulate after a mechanical trip and fall. Examination demonstrates that the left lower extremity is shortened, abducted and externally rotated. Hip and pelvis x-rays are obtained (Figure 1).
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Femoral neck fracture (Figure 2).
- Pearl: Proximal femur, or hip fractures are categorized into femoral neck, trochanteric, and subtrochanteric fractures [1]. There are over 250,000 cases in the US each year and they are associated with a mortality rate of 14-36% within 1 year of the fracture [1-3].
Figure 2. Femoral neck fracture shown by the green arrows. Authors’ own images.
The major risk factors for a hip fracture are osteoporosis, lack of physical activity, dementia, smoking, increased fall risk, age > 65, female sex and family history or prior history of hip fracture [2,4]. The most common mechanism is a ground level fall on the affected hip [5].
Examination may show the classic appearance of a shortened, abducted and externally rotated limb, but the deformity depends on the type of fracture and amount of displacement [3,4]. Pain is elicited with axial loading or the log roll maneuver of the affected extremity [4].
Plain radiography with AP of the pelvis and true lateral view of the hip should be performed [1,4]. Continued suspicion for a radiographically occult hip fracture warrants further imaging with a CT scan (sensitivity of 87%) or MRI (sensitivity of 100%) [6,7]. Ultrasound findings include joint effusion, hematoma and fracture line with a sensitivity of up to 100% [6].
Figure 3: Ultrasound findings of hip fractures. Authors’ own image and illustration.
Multimodal pain control with systemic analgesia including acetaminophen or opiates. There are several narcotic-sparing regional anesthesia techniques like fascia iliaca block or pericapsular nerve group (PENG) block that can be used for pre- and peri-operative pain control for hip fractures. These narcotic-sparing interventions can reduce the incidence of delirium in elderly patients. Local anesthetic systemic toxicity (LAST) is a rare, but life-threatening complication that can be minimized with the use of ultrasound-guidance, aspiration, and dilution of the local anesthetic [8].
- Pearl: In the fascia iliaca compartment block, local anesthetic is injected underneath the fascia iliaca to anesthetize the femoral, lateral femoral cutaneous and obturator nerve distributions (Figure 4).
Figure 4: Ultrasound-guided fascia iliaca compartment block. Authors’ own image and illustration.
Intracapsular fractures, including femoral neck fractures, typically disrupt the blood supply to the femoral head and are associated with nonunion and avascular necrosis. Thus, hemi- or total hip arthroplasty (Figure 5) is preferred over screw fixation in patients > 70 years of age with displaced femoral neck fractures to minimize these complications [1,2]. Meanwhile, extracapsular fractures, including intertrochanteric and subtrochanteric fractures, have an adequate blood supply and typically heal well after fixation with plates, sliding hip screws, or intramedullary nails [1,2].
Figure 5: Femoral neck fracture status post hemiarthroplasty. Authors’ own image.
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Resources and References
Check out ALiEM’s SplintER Series for more can’t miss diagnoses of the hip or the AIR Series module on lower extremity emergencies Â
- Zuckerman JD. Hip Fracture. N Engl J Med. 1996;334(23):1519-1525. PMID: 8618608
- Parker M, Johansen A. Hip fracture. Br Med J. 2006;333(7557):27-30. PMID: 16809710
- Emmerson BR, Varacallo M, Inman D. Hip Fracture Overview. StatPearls Publishing; 2020. Accessed December 10, 2020. PMID: 32491446
- LeBlanc KE, Muncie HL Jr, LeBlanc LL. Hip fracture: diagnosis, treatment, and secondary prevention. Am Fam Physician. 2014;89(12):945-951. PMID: 25162161
- Kelly DW, Kelly BD. A novel diagnostic sign of hip fracture mechanism in ground level falls: two case reports and review of the literature. J Med Case Rep. 2012;6(1):136. PMID: 22643013
- Safran O, Goldman V, Applbaum Y, et al. Posttraumatic painful hip: sonography as a screening test for occult hip fractures. J Ultrasound Med. 2009;28(11):1447-52. doi: 10.7863/jum.2009.28.11.1447. PMID: 19854958
- Weber AE, Jacobson JA, Bedi A. A review of imaging modalities for the hip. Curr Rev Musculoskelet Med. 2013;6(3):226-234. PMID: 23784063
- Steenberg J, Møller AM. Systematic review of the effects of fascia iliaca compartment block on hip fracture patients before operation. Br J Anaesth. 2018;120(6):1368-1380. PMID: 29793602
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