Charles A. Stewart

Regional Osteoporosis in Women Who Have a Complete Spinal Cord Injury

Background: Regional bone loss in patients who have a spinal cord injury has been evaluated in males. In addition, there have been reports on groups of patients of both genders who had an acute or chronic complete or incomplete spinal cord injury. Regional bone loss in females who have a complete spinal cord injury has not been reported, to our knowledge. Methods: In a study of thirty-one women who had a chronic, complete spinal cord injury, we assessed bone mineral density in relation to age, weight, and time since the injury. The results were compared with the bone mineral density in seventeen healthy, able-bodied women who had been age-matched by group (thirty years old and less, thirty-one to fifty years old, and more than fifty years old). Dual-energy x-ray absorptiometry was used to measure the bone mineral density of the lumbar spine, hip, and knee; Z-scores for the hip and spine were calculated. Results: The mean bone mineral density in the spine in the youngest, middle, and oldest spinal-cord-injury groups was 98%, 108%, and 115% of the densities in the respective age-matched control groups (p < 0.0001), and the mean bone mineral density in the oldest spinal-cord-injury group was equal to that in the youngest control group. This gain in bone mineral density in the spine was reflected by the spine Z-scores, as the mean score in the oldest injured group averaged more than one standard deviation above both the norm and the mean score in the control group. The mean loss of bone mineral density in the knee in the youngest, middle, and oldest spinal-cord-injury groups was 38%, 41%, and 47% compared with the densities in the corresponding control age-groups (p < 0.0001). Furthermore, the oldest injured group had a mean reduction of knee bone mineral density of 54% compared with the youngest control group. The mean loss of bone mineral density in the hips of the injured patients was 18%, 25%, and 25% compared with the densities in the control subjects in the respective age-groups (p < 0.0001). Conclusions: The bone mineral density in the spine either was maintained or was increased in relation to the time since the injury. This finding is unlike that seen in healthy women, in whom bone mineral density decreases with age. The bone mineral density in the hips of the injured patients initially decreased approximately 25%; thereafter, the rate of loss was similar to that in the control group. The bone mineral density in the knees of the injured patients rapidly decreased 40% to 45% and then further decreased only minimally. Clinical Relevance: The results provide a partial explanation of the fracture patterns seen after spinal cord injuries. Vertebral fractures rarely occur, whereas the knee is at risk for fracture soon after the spinal cord injury. The potential for fracture of the hip also occurs soon after the spinal cord injury. This risk increases with age and the amount of time since the spinal cord injury.

The effect of pulsed electromagnetic fields on osteoporosis at the knee in individuals with spinal cord injury.

The purpose of this study was to determine the effects of pulsed electromagnetic fields on osteoporotic bone at the knee in individuals with chronic spinal injury. The study consisted of 6 males with complete spinal cord injury at a minimum of 2 years duration. Bone mineral density (BMD) was obtained at both knees at initiation, 3 months, 6 months, and 12 months using dual energy X-ray absorptiometry. In each case, 1 knee was stimulated using The Bone Growth Stimulator Model 3005 from American Medical Electronics, Incorporated and the opposite knee served as the control. Stimulation ceased at 6 months. At 3 months BMD increased in the stimulated knees 5.1% and declined in the control knees 6.6% (p < .05 and p < .02, respectively). By 6 months the BMD returned to near baseline values and at 12 months both knees had lost bone at a similar rate to 2.4% below baseline for the stimulated knee and 3.6% below baseline for the control. There were larger effects closer to the site of stimulation. While the stimulation appeared useful in retarding osteoporosis, the unexpected exaggerated decline in the control knees and reversal at 6 months suggests underlying mechanisms are more complex than originally anticipated. The authors believe a local as well as a systemic response was created.

Fracture Threshold and Risk for Osteoporosis and Pathologic Fractures in Individuals with Spinal Cord Injury

The fracture threshold at the knee is a bone mineral density (BMD) of .78 gm/cm2 (−36% loss), while the breakpoint is .49 gm/cm2 (−57% loss). Using the knee as a proxy for the entire lower extremity (LE), fractures in the LE begin to occur when the BMD at the knee is .86 gm/cm2 (−25% loss) and peak at .49 gm/cm2 (−57% loss). Risk factors for fracture and osteoporosis include completeness of injury, paraplegia, body mass index (BMI) < 25 kg/m2, increasing age and duration of injury, female gender, and previous fracture. A woman with complete paraplegia and a BMI less than 25 kg/m2 is an appropriate candidate for early osteoporosis treatment.

Scintigraphic demonstration of splenosis

A case of splenosis, or the autotransplantation of splenic tissue following trauma, was encountered unexpectedly on a routine liver scan performed in the workup of alcoholic liver disease. Confirmatory scintigraphic images using Tc-99m labeled, heat-damaged, autologous erythrocytes are presented with CT scans of the abdomen.

Bone Loss with Aging and the Impact of SCI

One hundred forty-four individuals with chronic spinal cord injury (SCI), 129 men and 15 women, were evaluated by dual-energy x-ray absorptiometry (DXA) to assess the risk factors of age, duration of injury, neurological deficit, and body mass index (BMI) on the bone mineral densities (BMD) of the lumbar spine, hip, and knee. The participants, ages 18 to 50 years old, were categorized into four neurological classifications: 37 with complete tetraplegia, 25 with incomplete tetraplegia, 57 with complete paraplegia, and 25 with incomplete paraplegia. The effects of risk factors at the regional sites of SCI osteoporosis can be summarized: BMI influences all sites especially the knee; neurologic deficit affects the hip and especially the knee; duration of injury positively influences the spine and negatively influences the hip and the knee to a lesser degree; and age negatively effects the hip.

The Natural History of Bone Loss in the Lower Extremity of Complete Spinal Cord-Injured Males

Bone loss at the lower extremity (LE) in complete spinal cord-injured (SCI) men is divided into three phases: acute, initial 4 months; subacute, subsequent 12 months; and chronic, yearly. Acute loss at the hip, knee, os calcis, and LE is .5%, 1%, 2%, and 2% per week, respectively; subacute loss is .5%, 1%, 1%, and 1% per month, respectively; chronic loss is the same at each site but annually. LE bone loss intensifies from proximal to distal sites. The loss is continuously downward in the LE, tibia, and os calcis but eventually slows at and above the knee with 50% of individuals eventually gaining bone mineral at the hip.

Radionuclide and radiographic demonstration of condensing osteitis of the clavicle.

Radionuclide and radiographic images of a case of condensing osteitis of the clavicle are presented. The clinical and radiographic features are discussed along with a differential diagnosis of sclerotic lesions of the clavicle.

Heterotopic ossification. Effect on dual-photon absorptiometry of the hip.

Dual-photon absorptiometry (DPA) is now widely used to determine bone mineral density of the lumbar spine and hips. Because the resulting images are often not of sufficient resolution to identify many bone or soft tissue abnormalities that may influence results, clinical and radiographic correlation is necessary. Presented are two cases in which results of DPA of the hips were elevated because of the presence of heterotopic ossification.

Urinary bladder herniation into the scrotum : Incidental demonstration on bone scintigraphy

Bone scintigraphy was performed for staging in a patient with prostate carcinoma. Physical examination revealed an enlarged scrotum and inguinal hernia. The bone scintigrams demonstrated wide-spread bony metastases, as well as dense accumulation of activity in the scrotum that appeared contiguous with the urinary bladder. A radiocontrast cystogram confirmed herniation of the urinary bladder into the scrotum.

An index to measure the healing potential of ischaemic ulcers using Thallium 201

Prediction of healing of ulcers in ischaemic limbs can preclude unnecessary treatment for ulcers that cannot heal. Non-invasive methods are of marked value as the ischaemic limb is susceptible to further ulceration from local skin penetration. Relative hyperemia of the ulcer was measured by scintillation count over the ulcer and at points 2.5 cm from the edge of the ulcer. Relative hyperemia was determined by dividing the count per unit area of the ulcer by the counts per unit area of the surrounding tissue. All ulcers with a relative hyperemia over 1.5 healed.