Stress Fractures

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- Discussion:
    - occur as the result of repetitive loading below yeild strength & are most common in lower extremity (metatarsals > calcaneus > tibia);
           - Matheson et al.: 370 athletes with stress fractures tibia (49.1%), tarsals (25.3%), metatarsals (8.8%) and bilateral stress fractures in 16.6% of cases;
    - focal structural & muscle weakness & repetitive muscle pull are common;
    - common in athletes, esp in white women, with advancing age, and w/ underlying metabolic bone diseases;
    - differential dx:
    - predisposing factors:
           - menstrual irregularity, osteoporosis, diabetic or idiopathic neuropathy, smoking and alcohol intake, hypothyroidism, anorexia nervosa,
                  Paget's disease, and rheumatoid arthritis;
    - progression of stress fractures:
           - stage I - crack initiation: areas of stress concentration
           - stage II - crack propagation: no repair or more damage than repair
           - stage III - final fracture: cracks coalesce, enlarge, ultimate failure
    - history:
           - 1855 – Breithaupt described foot pain and swelling in military recruits
           - 1897 – Stechow recognized “march fracture” on radiographs
           - 1921 – Deutschlander reported six cases in civilian women
           - 1956 – Devas and Sweetnam noted fibula stress fractures in athletes

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- Work Up:
    - endocrine considerations:
           - menstrual irregularity
           - hyperparathyroidism (need to r/o hypercalcemia);
    - bone density study: (dual X-ray absorptiometry);

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- Specific Types of Stress Frx:
    - sacral stress fractures:
           - references:
                 - Jogger's fracture and other stress fractures of the lumbo-sacral spine.
    - pubic stress frx:
           - patients will note groin pain;
           - diff dx includes hernia and partial avulsion of the rectus abdominus;
           - bone scan may assist in the diagnosis;
           - references:
                 - Stress fractures of the pubic ramus. A report of twelve cases.
                 - Osteitis pubis in athletes: Infection, inflammation or injury? PA Fricker et al.  Sports Med. Vol 12. 1991. p 266-279.    
                 - Abdominal musculature abnormalities as a cause of groin pain in athletes.
                 - Osteitis pubis, Tc 99m, and professional hockey players. RC Briggs et al.  Clin. Nucl. Med. Vol 17. 1992. p 861-863.
    - femoral neck stress frx:
    - tibial stress frx
           - shin splints: 
    - foot and ankle stress frx:
           - risk factors: pronated feet, cavus feet, and increased external tibial torsion are common risk factors;
           - specific types of frx:
                 - distal fibular and medial malleolar frx: uncommon but do occur;
                 - calcaneal fatigue fractures:
                 - forefoot & midfoot stress frx
                 - navicular stress frx:
                 - metatarsal stress frx:
           - references:
                 - Diagnostic dilemmas in foot and ankle injuries.
                 - Stress fracture of the medial malleolus.
                 - Fatigue fractures of the foot and ankle in the athlete. SA Eisele et al JBJS. Vol 75-A. No 2. Feb 1993. p 290-298.
                 - Insufficiency stress fractures of the foot and ankle in postmenopausal women. RA Kaye MD  Foot and Ankle International. Vol 19. No 4. Arp 1998. p 221.

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Review Article: Stress Fractures: Current Concepts.

The long-term followup of soldiers with stress fractures.

Recurrent stress fractures in military recruits. One-year follow-up of 66 recruits.

External rotation of the hip. A predictor of risk for stress fractures.

The effect of pretraining sports activity on the incidence of stress fractures among military recruits. A prospective study.

Stress fractures in young athletes.

Stress Fractures around the Knee in Elderly Patients. A Cause of Acute Pain in the Knee.

MRI in stress fracture.   SA Stafford et al.  AJR. Vol 147. 1986. p 553-556.