Managing femoral head osteonecrosis in patients with sickle cell disease.

With an increasing number of people immigrating between different countries, sickle cell disease (SCD) is spreading all over the world. Due to improved health care, the life span of SCD patients has increased and many of them live to adulthood and middle-age. Osteonecrosis of the femoral head is one of the most common musculo-skeletal problems in SCD patients. Once osteonecrosis starts in the femoral head, it can progress from early to late stages in just a few years. Managing osteonecrosis of the femoral head in young-adults is a challenging problem and, in many situations, it requires major surgical procedures. In the early stages of the disease it is advisable to treat it by femoral head preserving procedures. In advanced stages, hip replacement arthroplasty (HPA) is indicated. In SCD patients, the incidence of operative complications and failure rates are higher than that for osteonecrosis due to other causes. Understanding the problems of SCD patients; appropriate diagnosis, prognosis, implications of the procedure performed and taking the necessary precautions, can reduce the complications and delay the failure of surgical procedures.

The value of ultrasound and aspiration in differentiating vaso-occlusive crisis and osteomyelitis in sickle cell disease patients.

We have studied 50 patients with sickle cell disease who presented with musculoskeletal pain over a 2-year period to assess the use of ultrasound in differentiating infection from infarction. All the patients were evaluated by ultrasound. Five had soft tissue oedema and no fluid collection adjacent to the bone. Forty-five had a subperiosteal fluid collection. Twelve patients whose collections were not aspirated were diagnosed according to clinical evaluation. The remaining 33 patients underwent aspiration under ultrasound guidance to distinguish between an infection and infarction. Twenty-three of these were diagnosed as osteomyelitis and 10 as vaso-occlusive crises. In 21 out of the 23 infected cases, the fluid collection was greater than 10 mm at its thickest point perpendicular to the bone surface and all those with infarction had fluid less than 10 mm thickness. Aspiration under ultrasound guidance is a useful method to differentiate the two clinical entities. In patients suffering from osteomyelitis, identification of the organisms guides antibiotic administration. Needle decompression can help to relieve pain in osteomyelitis and vaso-occlusive crisis.

New technique for assessing muscle damage after trauma.

We report a new technique which is a useful objective method for assessing the extent and severity of traumatic muscle damage using scintigraphic imaging. Radionuclide indium-111 antimyosin was used in 13 patients with trauma. The increased uptake was confined to the injured muscles and the intensity was related to the severity of damage.

Indium-111 monoclonal anti-myosin antibody in assessing skeletal muscle damage in trauma.

Accurate assessment of the severity of soft tissue damage particularly skeletal muscle associated with fractures in trauma patients is important in determining the plan of management and prognosis. We used Indium-111 labelled anti-myosin to determine the extent of skeletal muscle injury in five patients involved in traumatic accidents. We found abnormal uptake in all 20 sites of muscle injury in four patients, 13 at the sites of fractures and seven away from fracture sites. There was good correlation between the degree of uptake and the extent of muscle injury. No uptake was seen in a case with no fracture and no muscle injury. At surgery this case proved to be haemarthrosis of the left knee. Indium-111 anti-myosin scanning is a potentially sensitive and useful technique in assessing extent of acute muscle injury in trauma patients.

Role of thallium-201 in the diagnosis of solitary bone lesions.

Thallium-201 is known to accumulate in malignant tumours. In this work we are evaluating the role of thallium in differentiating benign from malignant solitary bone lesions in 28 patients with solitary bone lesions on 99Tcm-MDP bone scans. Lesions' uptake of 201Tl was evaluated using visual assessment and lesion to background ratio. We found significant uptake with a mean lesion to background ratio of 4.27 in malignant lesions and no or faint uptake with a mean lesion to background ratio of 1.37 in benign lesions.