80 year old female following a fall from standing. The image above shows an intertrochanteric fracture.
Femoral Neck Stress Fracture. A sub-capital fracture of the femoral neck.
Fractured Neck of Femur (NOF)
Fractured neck of femur is a very prevalent condition globally and poses a serious concern on both an individual and population level. It has been estimated that by the year 2050 there will be 6 million cases of hip fractures worldwide. (1)
The reasons for the increase in numbers are related to an ageing population. Elderly patients are more likely to sustain a fractured neck of femur through falls due to numerous factors:-
- Muscle weakness especially in the legs
- Unsteadiness of gait
- Decreased mental function and confusion for example dementia
- Decreased eyesight
- Osteoporosis: A progressive bone disease characterized by a decrease in bone density and mass leading to fragile bones and an increase risk of fracture (either with or without trauma). Osteoporosis can occur in women after menopause and, in both sexes, after the age of 75, the latter being referred to as senile osteoporosis.
- Underlying disease for example osteoarthritis
- Postural Hypotension
- Medications that cause dizziness or confusion.
Treatment for a fractured neck of femur is by surgical repair which may involve a partial or complete hip replacement. Some fractures can be fixed with plates and screws or rods to stabilise the bone and joint. The type of surgery depends upon numerous factors following a detailed assessment of each individual person and their specific injury. Contributing factors include the assessment of any underlying medical condition, age, type and location of the fracture and general level of mobility before the injury.
Fractures (not including stress fractures of the neck of femur) in the non-elderly population are usually caused by significant trauma such as sports accidents for example, skiing or motor accidents such as car and motorbike collisions.
Stress Fractures in the Non-Elderly Population
X-ray shows a stress fracture of the femoral neck.
32 year-old military personnel.
Stress fractures tend to occur in the non-elderly population amongst athletes, especially endurance athletes such as long distance runners, and military personnel. Stress fractures are more common in females(2) and occur most frequently in weight-bearing bones. They are typically characterised on X-Ray or scan by a hair-line fracture.
There are two types of Stress Fracture
- Fatigue Fracture: Occurs when abnormal stress is applied to bone with normal elastic resistance.
- Insufficiency Fracture: Occurs when normal or physiological stress is applied to bone with deficient elastic resistance(3)
To simplify then, a fatigue fracture happens when abnormal stress is put upon normal bone and an insufficiency fracture when normal stress is put upon abnormal bone. Usually bone adapts to an increase in function by increasing in density but if the strain put upon it exceeds it’s ability to repair itself than a stress fracture will result. This occurs most often when training programmes become too intense and too frequent not giving the bone enough rest time to repair itself.
The treatment obviously varies depending upon the severity of the fracture. In mild injuries (hair-line cracks) immobilisation with crutches to rest the fracture and promote healing combined with physiotherapy may be sufficient. In more serious cases, where the fracture is larger or unstable, surgery may be necessary. It is important that a stress fracture is recognised and treated quickly to avoid long term complications developing even in young, athletic patients.
(1) Kannus P, Parkkari J, Sievanen H, Heinonen A, Vouri I, Jarvinen M. (1996) “Epidemology of hip fractures”Bone 1, 57-63
(2) Niva M.H., Mattila V.M., Kiuru M.J., Pihlajamaki H.K. Bone stress injuries are common in female military trainees: a preliminary study. Clin Orthop Relat Res. 2009;467:2962–2969
(3) Fatigue, Insufficiency, and Pathologic Fractures Richard L. Pentecost, MD; Robert A. Murray, MD; Hanes H. Brindley, MD JAMA Journal of American Medical Association