A 34–year–old man with history of myocardial infarction, polysubstance use, hepatitis C, and lumbar disc disease presented with severe back pain and extremity weakness. The patient is a martial arts fighter who was restricting fluids to make a lower weight class. During a match, he suffered repeated blows to the back. Afterward he ingested an unknown amount of ibuprofen and snorted cocaine. He then slept for 1 hour but awoke with severe back pain and could not move his extremities. He stated his strength returned but noted lower back numbness and “tightness” without radiation. Physical exam revealed hard left paraspinal muscles and tenderness to palpation over this area, but no swelling. Sensation was intact and he had normal bilateral lower extremity motor strength. Initial laboratory measurements were as follows: serum creatinine 3.5 mg/dL; aspartate aminotransferase 1106 U/L; alanine aminotransferase 289 U/L; creatinine kinase (CK) 91,790. Lumbar x–rays showed a loss of lordosis and a non–contrast CT scan demonstrated mild degenerative changes of the spine but no paraspinal muscle abnormality. Compartment pressure measurements were obtained. Left and right proximal paraspinal muscle pressures were 20 and 38 mmHg respectively. The following day his CK improved to 63,310. However, persistent severe back pain prompted repeat pressure measurements showing left and right sided pressures of 110 and 115 mmHg respectively. He was taken for an emergent fasciotomy.
Acute compartment syndrome occurs when increased pressure within fascial spaces results in neurovascular compromise. It is rare in the paraspinal muscles and all cases occurred in non–traumatic situations. Risk factors include strenuous physical exertion, trauma, and impaired circulation during aortic bypass surgery. Nearly all patients were initially admitted for treatment of rhabdomyolysis. It is believed to cause rhabdomyolysis by muscle compression. There does not appear to be an increased risk for dialysis. Paraspinal compartment syndrome can share findings with other common causes of back pain. However, the physical exam includes tender paraspinal muscles, loss of lumbar lordosis, absent bowel sounds, and localized sensory loss on physical exam. Pain is out of proportion to exam and is exacerbated by valsalva maneuvers, passive and active spinal flexion, or straight leg maneuvers. CT scans can show muscle swelling but may be normal. MRI demonstrates increased T2–weighted signal intensity. While compartment pressure measurement remains the gold standard for diagnosis, there is no consensus regarding a pressure threshold for fasciotomy. Some use 30 mmHg as a cut off, while others utilize the difference between diastolic and compartment pressures (delta pressure). Definitive management includes surgical decompression.
Early recognition of paraspinal compartment syndrome in a patient with acute, severe back pain and rhabdomyolysis is crucial to prevent permanent muscle and nerve damage.