Heterotopic ossification mimicking infection in patients with traumatic spinal cord injury

Heterotopic ossification (HO) is a common concominant condition in patients with traumatic spinal cord injury (SCI). In this context, we report on patients with heterotopic ossification causing infection like symptoms as a first manifestation of HO subsequent to traumatic SCI.

The objective of the study was to analyse possible ``early-indicator symptoms'' in patients suffering from heterotopic ossification following SCI with special focus on elevated serum CRP, serum CK and body temperature.

All eligible patients treated between January 2004 and December 2013 because of a SCI and heterotopic ossification have been enrolled in this retrospective study. An age below 18 years and the absence of the combination of elevated serum CRP, CK and elevated body temperature (> 38.5 °C) were defined as exclusion criteria. The presence of another infection, led to exclusion. Fifteen out of 235 patients (6.4%) met the inclusion criteria and were included in the final data analysis.

The patient cohort consists of 13 male and two female patients with a mean age of 30.6 years (range from 18 to 56 years; SD = 13.5). The mean time interval between HO development and the injury was 49.4 days (range from 16 to 131 days; SD = 34.3). Focussing on laboratory parameters, mean serum CRP level was 10.2 mg/dl (range from 1.3 to 24.4 mg/dl; SD = 9.6). Mean serum CK was 1365 U/l (range from 255 to 4729 U/l; SD = 1491). Worth mentioning, in 9 cases (60%) serum CK was higher than 500 U/l. Mean body temperature was 38.7 °C (range from 38.0 to 39.4; SD = 0.4). CT scans of the thorax, abdomen and pelvis revealed no further pathologies besides the heterotopic ossification. Urinary tract infections were ruled out, using urine tests as a standard procedure in all cases.

Elevated levels of serum CRP, serum CK and high body temperature in acute SCI may be considered as indicators for a concominant HO diagnosis.