HISTORY: A 61 year old horseback rider with severe OA and labral tear of the left hip underwent her 3rd fluoroscopically-guided triamcinolone injection for pain relief during competition season. She immediately experienced gradual worsening of left groin pain but was able to continue training. Ten days post-injection, she returned with severe groin pain limiting weight bearing. She planned to leave the following day for a trip. She had no fever, chills, swelling, bruising or rash. She had mild pain with hip ROM testing. CRP was elevated without leukocytosis. MRI showed a small effusion with mild synovial inflammation. In the absence of systemic signs of infection, findings were consistent with reactive synovitis with low suspicion for infection. Upon discussion, the patient elected to proceed with her trip, monitor her symptoms closely, and present to a local ED if symptoms worsened. She returned 2 weeks later unable to bear weight. PHYSICAL EXAMINATION: Left hip exam demonstrated full passive internal and external rotation. Focal groin pain was reproduced by both active and passive ROM. No neurological deficits. DIFFERENTIAL DIAGNOSIS:
1. Septic arthritis
2. Avascular necrosis
3. Hemarthrosis
4. Reactive or crystalline synovitis
TESTS AND RESULTS:
XR pelvis w/L lateral hip: Collapse of superior joint space with subchondral cystic change.
L Hip Aspiration: 4 mL bloody effusion (4.9 million RBCs, 2668 WBC, 69% PMNs). Synovasure positive. Open I&D w/resection of the femoral head and placement of
antibiotic spacer
- Synovitis with small amount of clear joint effusion. No gross purulence. Subchondral collapse and area of necrotic bone in the femoral head.
- 1/5 periarticular tissue cultures and 1/1 bone culture positive for Strep mitis/oralis.
- Bone path revealed acute osteomyelitis and osteonecrosis.
FINAL WORKING DIAGNOSIS
Septic arthritis and osteomyelitis of the left native hip
TREATMENT AND OUTCOMES
1. Six week course of IV ceftriaxone
2. Re-admitted 3 weeks post-op for fever, chills, headache and severe L hip pain following return to riding. Two extra-articular hematomas were identified on MRI and
aspirated.
3. Re-admitted 6 weeks post-op for iliofemoral DVT. Underwent catheter-directed thrombolysis and stent placement for May Thurner’s defect. Started on 6 months of Xarelto.
4. Left THA completed 6 weeks post-DVT.