Autologous stem cell implantation with core decompression for avascular necrosis of the femoral head using a new device.

INTRODUCTION: Autologous stem cell progenitor implantation into necrotic lesions of the femoral head has previously been described as a potential treatment for avascular necrosis (AVN), on the basis that there is a reduced number of functioning stem cells in the marrow within the necrotic segment. We present a case series of patients with AVN that underwent core decompression with autologous stem cell implantation using a new device. METHODS: The records and imaging of patients with AVN of the femoral head treated by a single surgeon were retrospectively reviewed. All patients were treated with core decompression and stem cell progenitor implantation, using the PerFuse system. Preoperatively, demographic information, AVN staging (as per Ficat and Arlet classification) and visual analogue pain scores (VAS) of the hips were recorded. These results were compared with postoperative VAS and imaging, with further review on the progression of AVN. RESULTS: We treated 14 hips in 13 patients with an average follow up of 12 months. Patients with Ficat I-II were selected for the procedure. The average preoperative VAS was 3.9. Postoperatively, this dropped to 2.6, with over half of patients reporting at least a two-point decrease in pain. Eight of the 14 treated hips showed no radiological progression of the disease, while six showed femoral head collapse requiring total hip arthroplasty (THA) at an average of ten months after treatment. CONCLUSION: Our early findings indicate that hip decompression with stem cell progenitor implantation for AVN of the femoral head provides symptomatic relief and may be beneficial in arresting progression of disease using this simple new device.

Bone mineral density in patients receiving suppressive doses of thyroxine for thyroid carcinoma.

AIMS: Studies of the effect of thyroxine therapy on skeletal integrity have given conflicting results; the reductions in bone mass reported by some have prompted recommendations that the prescribed replacement doses of thyroxine should be reduced. We have examined bone mineral density in a group of patients with differentiated thyroid carcinoma receiving high doses of thyroxine to suppress thyroid stimulating hormone (TSH). METHODS: The 44 patients (6 male, 38 female) had a median age of 49 years (range 27-75) with median duration of thyroxine therapy of 9.0 years (range 3 to 42) and mean dose of thyroxine 0.167 mg/day (range 0.125-0.3). TSH levels were chronically suppressed in 39 subjects. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DEXA) in all subjects at the femoral neck and lumbar spine and compared with previously established local reference ranges. RESULTS: There was no reduction in bone mineral density in the thyroxine treated group compared with the local reference population at both lumbar spine and femoral neck, and no correlation with duration of therapy. CONCLUSIONS: These negative findings, that thyroxine in suppressive doses does not significantly reduce bone mineral density in New Zealand patients suggest that thyroxine therapy alone is not a major risk factor for the development of osteoporosis.

Historical assessment of risk factors in screening for osteopenia in a normal Caucasian population.

BACKGROUND: Bone mineral density (BMD) can predict fracture, however, the common use of historical risk factors to predict low BMD is unproven. AIMS: To identify significant historical risk factors for osteopenia. To establish predicting equations for BMD and test their ability to identify those who should be referred for BMD scanning. METHODS: Three hundred and twenty female and 131 male volunteers underwent questionnaire assessment of risk factors and BMD by dual photon absorptiometer at hip and spine. Significant risk factors (P < 0.05) were used to construct a linear regression model to predict BMD. This was cross validated on a second sample of 107 females and 131 males selected from the electoral roll analysing the ability to detect those subjects with BMD in the lower third of the age matched normal range. RESULTS: In women lower BMD at the spine was associated with increased age, decreased weight, smoking, and delayed menarche. Lower femoral BMD was associated with increased age, decreased weight, family history, inactivity, and smoking. In men lower BMD at the lumbar spine was associated with lower weight, and inactivity. Lower BMD at the femur was associated with increased age, decreased weight, family history, and low calcium intake. When cross validated on the second sample, the models produced sensitivity of 86-89% and sensitivity of 25-46%. Referring those with these risk factors could save 10-23% on scanning. Measuring BMD at the site in question remains the only accurate way of assessing an individual's risk of osteopenia.

Asymptomatic low bone mineral density in otherwise healthy people: four year follow up.

AIM: To determine the effect of screening a normal population for low bone density on lifestyle, subsequent bone density and fracture risk. METHOD: A cross sectional study of 726 subjects screened for low bone density identified 60 with bone density greater than one standard deviation below an age and sex matched mean. Those who accepted further assessment were followed clinically and with repeat bone densitometry for up to four years. Those declining assessment were contacted four years later and questioned about lifestyle changes and fractures. They were offered repeat bone densitometry. RESULTS: Twenty five subjects accepted intervention and were advised on lifestyle modification and treated with calcium supplements (18) calcitriol (5) or oestrogen (1). 22 of the 35 subjects who initially declined intervention volunteered to have their bone density repeated. Bone density increased in the group accepting intervention compared to the 22 subjects in the group who initially declined assessment (p < 0.05). Several laboratory investigations had a low yield. Lifestyle modification in the group declining assessment did not significantly affect subsequent bone density. Fractures occurred infrequently in both groups. CONCLUSION: After screening the normal population for low bone density, significant improvements in bone density can be achieved in patients accepting further intervention.

Factors affecting bone mineral density in high school girls.

OBJECTIVES: first to establish a local normal range for hip and spine bone density in the teenage years. Secondly to determine what factors might affect bone mineral density at this age. METHODS: bone mineral density (DPX absorptiometer) at the hip and spine in a cohort of 138 high school girls; mean age 16.4 yr (SD 0.34). Anthropometric factors, calcium intake, physical activity and other lifestyle and medical data were documented in each subject. RESULTS: in this group of 16 year old schoolgirls mean bone mineral density at the hip, 1.01 (0.13) was not significantly different from 20-25 year old New Zealand females, but bone mineral density at lumbar spine, 1.17 (0.12), was significantly lower. Positive correlations of bone mineral density with weight, height, physical activity and calcium intake were demonstrated. Weight was clearly the best predictor of bone mineral density variability. Calcium intake and physical activity showed no predictive value at the spine but contributed significantly at all regions of the femur and particularly at the trochanter. CONCLUSIONS: it appears that peak bone mass can be modified by nutrition and exercise. Adolescents should be encouraged into regular exercise programmes and to maintain adequate body mass and calcium intakes.

Effects of age and sex on bone density at the hip and spine in a normal Caucasian New Zealand population.

We have studied a normal adult caucasian population (462 females, 264 males age range 20-84) using dual photon absorptiometry to establish patterns of bone reduction at the spine and hip. Subjects were either randomly selected from the electoral roll or volunteers. Bone mineral density reduction at the lumbar spine in females appeared to increase at 40 years and was sustained until 60 years. In males bone mineral density at the spine was preserved. The density at the hip in females decreased throughout adult life beginning before the menopause. In males bone density was preserved at the femoral neck and trochanteric region but not at Wards triangle where reduction occurred throughout life. When compared with other normal populations there was higher bone mineral density at the spine in postmenopausal New Zealand females but no significant difference at the hip.