Compartment Syndrome in a Child Secondary to Acute Osteomyelitis of the Ulna

Abstract

To the Editors: Musculoskeletal infections are common in children. On rare occasions, chronic osteomyelitis can lead to compartment syndrome. Compartment syndrome of the forearm usually develops in the presence of fractures, soft tissue damage, burns, or arterial injury.1 It is difficult to diagnose in children. Restlessness, agitation, and an increasing analgesia requirement are clinical signs of compartment syndrome.2 Prompt intervention is critical in preventing complications. We report a case of acute ulnar osteomyelitis presenting as compartment syndrome of the forearm. CASE REPORT A 5-year-old right-hand dominant male presented with 2 days of left forearm pain, swelling, and erythema. There was no history of trauma, fever, or chills. His temperature was 102.3°F on presentation. Physical examination demonstrated significant swelling of the left forearm. Any passive movement of the wrist or fingers caused severe pain. White blood cell count (WBC) was 40 K/μL (4.4–11.0 K/μL), erythrocyte sedimentation rate (ESR) was 23 mm/HR (0–15 mm/HR), and the C-reactive protein (CRP) was 93.8 mg/L (<8.00 mg/L). Blood cultures obtained showed no growth. Radiographs were normal. The clinical examination raised concern for compartment syndrome and compartment pressures were measured. The volar compartment pressure was elevated (50 mm Hg), whereas the pressure in other compartments was normal. The patient was diagnosed with acute compartment syndrome. A magnetic resonance imaging (MRI) study could not be immediately obtained. Given the urgency of the patient's condition, he was taken emergently for forearm fasciotomies and exploration. Operative Findings The patient had significant swelling over the volar forearm compartment. The fascia over this compartment was released with immediate muscle bulging. No muscle necrosis was present. Cloudy fluid was found in the deep volar compartment and was sent for Gram stain and culture. The ulna periosteum was incised and significant purulence was evacuated. A wound VAC sponge was placed over the wound, because a primary closure could not be obtained. Postoperative Course The patient was given empiric antibiotic therapy. Intraoperative cultures were positive for methicillin-susceptible Staphylococcus aureus. The patient subsequently received a peripherally-inserted central catheter (PICC) and was treated with intravenous nafcillin for 5 weeks. An MRI performed on the first postoperative day showed abnormal bone signal in the distal ulna, a subperiosteal abscess, and extensive edema. The signal change in the ulna was far distal to the area of maximal muscle swelling. The patient rapidly defervesced. He returned to the operating room where the distal ulna was drilled with release of more purulent fluid. He also underwent delayed closure of his fasciotomy incision. The patient remained afebrile after his index procedure. He was discharged home with a PICC line for antibiotic therapy. DISCUSSION Compartment syndrome has been rarely reported after chronic osteomyelitis.3 Osteomyelitis develops via direct inoculation, hematogenous spread from bacteremia, or local invasion from a nearby focus of infection. History of trauma is often associated with the development of infection either locally or at a remote site.4 When faced with a clinical picture suggesting infection with associated compartmental swelling, the differential diagnosis includes infectious myositis, necrotizing fasciitis, neoplasm such as Ewing sarcoma, and infected post-traumatic hematoma. MRI is helpful in the initial evaluation. However, delaying the initial surgical treatment of these patients to obtain imaging studies is not necessary because the radiologic diagnosis is not compromised by surgical intervention. Delayed diagnosis of compartment syndrome can lead to muscle infarction, muscle contracture, and motor or sensory deficits. Infection is rarely a problem in these cases. However, if fasciotomies are done after irreversible injury, secondary infection may develop and can lead to amputation. Mary Mulcahey, MD Nikhil Thakur, MD Stephen Tocci, MD Craig Eberson, MD Department of Orthopedics Warren Alpert Medical School of Brown University Rhode Island Hospital Providence, RI