Idiopathic Leg Pain-Pediatrics

CLINICAL CASE HISTORY: An 18-month-old male presented to clinic with limp for 1 week. Patient was recovering from a cold with resolved rhinorrhea and was treated with NSAIDs every 6 hours with minimal improvement in ambulation. In the clinic, the patient was very irritable with limited use of left leg. Mother denied any recent falls/trauma, fevers, joint swelling, rashes, changes in behavior, cough, congestion. Reported dad was at home sick with diagnosed strep throat. Due to non-improving symptoms, the patient was transferred to ED for further workup and admitted to the floor in stable condition. PHYSICAL EXAMINATION: Afebrile with stable vitals. On exam, left hip in ER and flexed. No lacs or deformities noted on LE. No swelling, erythema, or warmth noted on b/l hip, knee, and ankle joints. No TTP over hip, femur, knee, leg or ankle. Pain with PROM of left hip and knee. No pain with PROM of ankles. Sporadically moves LLE. 5/5 strength. 2+ dP Throughout exam the patient was grimacing in pain. On ambulation, patient favored the right leg and upon bearing weight with left leg, patient immediately buckled. No neurological symptoms or signs. DIFFERENTIAL DIAGNOSIS: 1. Transient synovitis 2. Septic Left Hip joint 3. Oligoarticular JIA TEST AND RESULTS: Blood work: WBC 12.3, sed rate 31 and CRP 2.0. XR HIP: No acute fx or dislocation XR KNEE No acute fx or dislocation XR PELVIS: No acute fx or dislocation US LE JOINTS: No joint effusion in bilateral hip and knees. XR TIBIA FIBULA: No evidence of acute or healing fx. The osseous structures are in anatomic alignment. MRI FEMUR LEFT: Osteomyelitis with intraosseous abscess of the distal left femur. FINAL/WORKING DIAGNOSIS: Osteomyelitis with intraosseous abscess of the distal left femur. TREATMENT AND OUTCOMES: 1. Orthopedic Surgery: Irrigation and excisional debridement, osteomyelitis, left distal femur. 2. Ancef, blood cultures, bone cultures 3. Safe ambulation and mobility education, left leg strengthening and gentle knee PROM. No physical activity restrictions. Pt was safe for home dc from a mobility standpoint, no assisted device or further PT needed. 4. Repeat radiographs one week post op 5. Pt regained full mobility with resolution of limp after 1 month of discharge