Based on the results of studies of peripheral CS, various pressures have been suggested as critical limits for surgical intervention. Whitesides et al. proposed that fasciotomy should be performed when the compartment pressure has increased to within 10–30 mmHg of diastolic pressure, or approximately 50–70 mmHg in a normotensive individual . Mubarak and Hargens suggested that an absolute pressure of 30 mmHg was critical [11, 12]. Matsen et al. reported that only patients with an intracompartmental pressure of > 45 mmHg could be definitively diagnosed with CS . According to Mubarak, operative decompression is the only satisfactory treatment for CS in the extremities.
Songcharoen studied 20 volunteers to evaluate normal compartment pressures at rest and during weight-lifting exercise . They reported that the mean resting paravertebral compartment pressure was 3.11 mmHg (range 0–11 mmHg) in the prone position and 7.95 mmHg (range 2–20 mmHg) in the sitting position. When a weight of 40 pounds was lifted with a straight back at lift-off, the mean paravertebral compartment pressure was 7.11 mmHg (range 3–30 mmHg), and the pressure returned to the pre-exercise level at 2.16 min (range 1-5 min) after completing the exercise. Peck et al. performed a similar study and reported a mean resting pressure of 10.8 mmHg (7.2-16.4 mmHg) with a mean peak dynamic pressure of 95 mmHg . In all cases, the pressure returned to the normal resting level within 2 seconds of completing the exercise.
Konno et al. studied the relationships between intramuscular pressure of the lumbar back muscles, and pain and degenerative spine disease, in 102 patients with lower back pain with or without neurological deficits . Intramuscular pressure measurements of the lumbar back muscles were performed in various positions. They found that lower back pain was associated with increased intramuscular pressure in the lumbar compartment, and concluded that measurement of intramuscular pressure is an objective method of differentiating between organic and psychogenic back pain. Styf and Lysell reported a patient with exercise-induced chronic back pain caused by chronic CS. They concluded that CS was an uncommon cause of exercise-induced lower back pain .
Paravertebral CS has previously been reported in downhill skiers, surfboarders and weight lifters, as well as in reperfusion injury after surgery of the abdominal aorta [6, 15, 17–21]. Sport-induced CS mainly affects males aged between 20 and 30 years, and generally starts about 2 hours after training. The pain is typically unresponsive to non-narcotic pain medication.
The diagnosis of CS is confirmed by detection of high levels of myoglobin in the serum and urine, a high serum CPK level, and computed tomography findings suggestive of ischemia and necrosis. In all reported cases of paravertebral CS, the main symptom was steadily increasing pain which started within 12 hours of exercise. None of the patients had radicular irritation in the lower extremity. Paravertebral loss of sensation has previously been reported to be a potentially useful sign for early detection of CS. The loss of sensation is thought to result from dysfunction of the lateral branches of the posterior primary rami at multiple levels . Our patient also had a loss of sensation over the paravertebral region. Interestingly, bowel sounds were reported to be diminished in all other patients, with or without abdominal tenderness. Absence of bowel sounds may result from biochemical abnormalities associated with rhabdomyolysis. Our patient had no abdominal symptoms and had normal bowel sounds.
Laboratory findings showed a high serum CPK level and high serum and urine myoglobin levels. Rhabdomyolysis is suspected when the serum CPK level is > 5000 U/l and there are high levels of myoglobin in the serum and urine. In our patient, CS of the paravertebral muscles was indicated by these abnormal laboratory values.
MRI is the preferred radiological examination in patients with suspected CS. Typical MRI findings include muscle edema and hyperintense areas on T2-weighted images. Decreased gadolinium uptake suggests muscle necrosis. In our patient, T2-weighted MRI findings suggested paravertebral muscle edema.
Most previously reported patients with lumbar paravertebral CS were managed by conservative treatment. Careful attention to pain control is very important. Conservative treatment includes administration of analgesics and crystalloid fluid, urine alkalinization and bed rest. In our patient, conservative treatment was not feasible because of the severe pain and increasing serum CPK level. Patients who were managed conservatively experienced only mild back pain on vigorous exertion, and the sequelae of such a condition may be unimportant, making operative decompression unnecessary. Nevertheless, Styf and Lysell reported that fasciotomy relieved the pain in a patient with chronic unilateral lumbar paravertebral CS .
In our case, surgery was performed using the Wiltse approach. Wiltse described a modified transmuscular paravertebral approach consisting of longitudinal separation of the sacrospinalis muscle between its multifidus and longissimus parts .
To date, only 11 cases of acute paravertebral CS have been reported. Three of these were treated with fasciotomy, resulting in full recovery. We therefore conclude that surgical therapy has good outcomes for both acute and chronic CS.
Two further points should be discussed regarding this case. First, the fascia was left open, but the skin was closed. The decision to close the skin was based on the lack of noticeable tension at the wound margins. Second, none of the gray, non-contractile muscle tissue was removed, except for the biopsy specimen. There was intraoperative discussion regarding the need for total resection of the abnormal muscle tissue. In our opinion, the potential for regeneration of the muscle cannot be determined at the time of decompression, and we therefore did not resect the muscle. Intramuscular scar tissue was assumed to be more beneficial for functional regeneration of this long muscle bundle than the potential muscle defect caused by resection.
In conclusion, acute paravertebral CS should be considered in the differential diagnosis of patients with acute exertional back pain, especially if the pain seems out of proportion to the exertion. We experienced good results after performing surgical decompression in a patient with acute lumbar paravertebral CS after excessive training.
Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.