A 67 year old diabetic lady presented with left groin pain for three weeks off and on associated with fever to the Orthopedic Clinic at the Aga Khan University Hospital, an academic tertiary care hospital in Karachi, Pakistan. She underwent un-cemented unipolar hemiarthoplasty of the left hip 8 years back. On examination, she was unable to elicit active movements at left hip. Personal and family history was negative for tuberculosis and wound infection at the index hip surgery. There was no relevant drug, family and genetic and psychosocial history.
Lab workup was done which showed raised serum infective markers. White cell count was 11.9 x 109/L, erythrocyte sedimentation rate was 118 mm/h (0-20) and CRP was 13.45 mg/dl (0-0.5). Urine culture was negative. Chest radiograph was normal. Hip radiographs demonstrated uncemented unipolar left hip arthroplasty with no evidence of any radiolucency or prosthetic loosening (Fig. 1). Moderate degenerative changes were found on radiograph of lumbosacral spine more marked at L4-L5 and L5-S1 level. Ultrasound of hip joint was performed before proceeding with surgery. Two ml pus was aspirated and culture showed growth of E. coli. Due to left groin pain, markedly elevated ESR and CRP and positive culture from hip aspiration, patient was planned for left hip arthrotomy. The surgery was performed by a consultant orthopaedic surgeon. The previous Moore approach was used for left hip arthrotomy. Hip joint appeared normal and implant was noted to be well fixed. Clear fluid was noted in hip joint at the level of psoas muscle. Pus was debrided at the lesser trochanter. Tissue sample was sent for culture and sensitivity which showed E coli and histopathology reported with psoas abscess. Computed tomography scan of abdomen was performed showing bilateral perinephritic fat standing with dilated ureters suggestive of Pyelonephritis (Fig. 2).
Patient was seen by infectious disease service. Patient tolerated the procedure well and there were no postoperative complications. Post operatively she was started on antibiotics which were continued for three months. She was mobilized weight bearing as tolerated with support postoperatively.The range of motion was restored with normal gait, initially ambulating with support followed by progressive improvement in her range of motion to 70  flexion, 30  abduction, 10  internal rotation and 15  external rotation within two weeks.
ESR and CRP returned to normal limits. Twenty months later, she remains asymptomatic without evidence of infection.