What is it?
A lumbar spine stress fracture, more specifically, a spondylolysis, is a unilateral or bilateral defect of the pars interarticularis (connection point of the superior and inferior facet surfaces in the spine at a given level, most commonly at the L5 vertebra).
This defect may be an acute fracture or a chronic disruption of sclerotic borders. This commonly occurs due to excessive and repetitive extension movements combined with rotation during athletic activity.
A spondylolysis can progress into a spondylolisthesis if precaution is not taken early or there is a failure to diagnose.
Who’s at risk?
- Adolescent Age Group: 30-40% of adolescent athletes who had back pain for greater than 2 weeks had spondylolysis
- Males more prone than females
- Athletes participating in baseball, track and field throwing events, gymnastics, weightlifting, soccer
Typical Presentation:
Complaints of a non-traumatic, insidious/gradual-onset, pinpoint low back pain that worsens with activity (especially lumbar extension movements) and decreases with rest. This may also occur due to a traumatic event in sport with a forced lumbar extension/rotation movement (i.e. snatch or forceful landing on feet with lumbar extension). Typically, little to no pain radiating into the lower extremities. Increased lumbar lordosis and hamstring tightness. Pain with sitting is unlikely. Tenderness upon palpation of the paraspinal muscles.
Diagnosis:
Physical Therapy/Clinical Assessment:
Clinical tests in therapy are neither specific nor sensitive. A few tests that may be used include lumbar extension tests in prone (left photo), quadrant testing (extension + rotation in standing) [middle photo], and the single-leg hyperextension test (right photo) where the athlete stands on one leg and extends the low back. However, these are not nearly 100% accurate tests and imaging is needed for a confident diagnosis.
Radiographs:
X-rays/radiographs are not the most accurate method of diagnosing lumbar spine stress fractures. Anterior/Posterior and Lateral view radiographs are the most common views utilized. Radiologist will often look for the “Scotty Dog Collar Sign” to diagnose.
Advanced Imaging:
CT or SPECT (single proton emission computed tomography) is the gold standard but exposes the patient to significant amounts of radiation. MRI has become more popular and has improved accuracy in detection with decreased radiation exposure.
Prognosis:
92% of athletes are able to return to sport with little to no pain in 6 months. Unilateral injuries are more likely to heal (71%) versus bilateral injuries (18%). The typical course of rehabilitation will course 2-6 months and is based on functionality of the athlete.
Treatment: (3-6 months)
Rest Stage (~ 2-4 weeks)
- No sports participation, limit recreational activities, no physical education class
- Core activation/initiation
- Abdominal bracing techniques
Foundational Rehabilitation Stage (~Weeks 4-12)
- Continue with core activation and abdominal bracing; progress exercise difficulty as able
- Promote low impact aerobic conditioning program
Recovery Rehabilitation Stage (~Weeks 8-16)
- Resistance training with proper spine stabilization
- Promote aerobic conditioning program
- Maintain mobility needed for sport
Functional Rehabilitation Stage (> 8 weeks, when progressed through Recovery Stage)
- Strength and conditioning program (sport specific)
- Dynamic spinal stabilization exercises
Return to Sport Criteria
- Full, pain-free range of motion
- Normal strength and aerobic fitness
- Able to perform sports-related skills without pain