. Biocomposites in Joint Replacement. OrthopaedicsOne Cases. In: OrthopaedicsOne - The Orthopaedic Knowledge Network. Created Jun 04, 2012 05:08. Last modified Aug 21, 2012 06:15 ver.5. Retrieved 2017-11-24, from http://www.orthopaedicsone.com/x/e4UXBQ.
Avascular necrosis of bone is a common problem in patients with sickle cell disease, most frequently affecting the hip and driving patients to seek hip replacement. This scenario can be complicated by osteomyelitis.
In this case report, we discuss how we approached the management of a patient with these concomitant issues, including the use of an antibiotic biocomposite mixture in the joint replacement.
The patient was a 34-year-old Nigerian male, one of six siblings. Both parents were haploid for sickle cell trait. He was only one of the siblings with sickle cell disease.
He presented with Grade IV avascular necrosis of the left hip, requiring hip replacement. The work-up for a joint replacement included:
- Complete blood count
- Erythrocyte sedimentation rate (ESR)
- Haemoglobin electrophoresis
- Blood culture
- Pre-operative X-rays of the hip
- MRI & CT scans of the hip
- Bacteriological analysis of joint aspirate
The ESR was elevated at 121 mm/hr and the white blood count was 12,000/cu mm. Blood culture was negative. The X-ray of the pelvis revealed avascular changes of both hips with secondary osteoarthritic changes. The proximal portion of the left femur had a bone-in-bone appearance, with some discontinuity seen in the region below the greater trochanter.
An MRI with contrast was then done, which showed a breach in the cortex with a bright signal intensity that was negative to fat suppression. There was edema in the surrounding tissues, and an effusion was present in the hip joint. CT-guided biopsy taken from the area drew a sample of yellowish fluid, which was set up for culture in two labs. One lab reported a negative culture; the other reported a growth of scanty “coagulase negative staphylococcus.”
With a near-positive diagnosis of chronic osteomyelitis, the patient was scheduled for an open debridement.
A lateral approach to the hip was used, with division of the vastus lateralis. A cavitary lesion was identified below the greater trochanter and was debrided thoroughly and a specimen sent for culture. A bio-absorbable bone substitute of calcium sulfate and antibiotic was packed inside the cavity to deliver a high local concentration of the antibiotics vancomycin and tobramycin. In addition, an intravenous infusion of vancomycin and clindamycin was started.
The patient made good progress over 6 weeks of local and intravenous antibiotic therapy, with his inflammatory parameters returning to normal. His pain subsided and his keenness to proceed to hip replacement has diminished. However, he will still require a hip replacement at some stage.