Comparison of metal versus absorbable implants in tension-band wiring: a preliminary study.

The strength of tension-band wiring using bioabsorbable materials versus metal implants was assessed with a rabbit knee fusion model. Ten rabbit knees were osteotomized and rigidly fixed using a tension-band technique: five with metal implants (2 pins and 24-gauge wire) and five with absorbable implants (2-mm pins [Bionx, Blue Bell, Pa] and 1 Maxon [Davis and Geck, Danbury, Conn]). Biomechanical testing of the fixation strength was completed using a servohydraulic mechanical testing machine and a specifically designed four-point bending jig. The parameters assessed were maximal load, relative stiffness, displacement, and bending moment of the constructs. Results of the biomechanical testing showed no statistical difference between the constructs on any of the parameters assessed.

Quantitative ultrasound: an indicator of osteoporosis in perimenopausal women.

The key to effective treatment of osteoporosis is early detection; however, the disease in perimenopausal women is frequently undiagnosed. To assess the utility of quantitative ultrasound (QUS) at the calcaneus in perimenopausal women, broadband ultrasound attenuation (BUA); speed of sound (SOS); quantitative ultra-sound index (QUI), an algorithm of BUA and SOS; and bone mineral density by dual X-ray absorptiometry (DXA) of the posteroanteiror spine, femoral neck, and total hip were measured in 420 women (ages 45-55 yr). Thirty (7.1%) of the women were found to be osteoporotic by DXA. All QUS measurements were predictors of osteoporosis. QUS values did not differ between postmenopausal women on estrogen replacement therapy (ERT) and those not on ERT. There were no differences among BUA, SOS, and QUI in the area under the receiver operating characteristic curves for predicting osteoporotic vs nonosteoporotic cases. At a QUI of 89, ultrasound had an 80% sensitivity for the diagnosis of osteoporosis, but only a 74% specificity. The use of QUS in perimenopausal women will facilitate the identification of women with osteoporosis. However, the high false-positive rate (26%) limits the utility of QUS as the sole diagnostic technique on which to base therapeutic decisions. Nevertheless, low QUS measurements may provide a means for targeting those women who would benefit most from more extensive evaluation (e. g., DXA).

Bone mineral density and broadband ultrasound attenuation with estrogen treatment of postmenopausal women.

The purpose of the current study was to determine the changes in lumbar spine, hip, and calcaneus bone mineral density (BMD), and in calcaneus broadband ultrasound attenuation (BUA) in early menopausal women and to assess the effects of estrogen replacement therapy (ERT) on bone mass at these sites over a 2-yr period. Fifty-three Caucasian women who were at least 6 mo postmenopausal were divided into two groups based on estrogen use. Twenty-one women, average age 53.0 +/- 0.6 yr and 2.9 +/- 0.3 yr since menopause, had been receiving estrogen in combination with progesterone for at least 6 mo prior to enrollment in the study. Thirty-two women, average age 52.7 +/- 0.8 yr and 2.8 +/- 0.3 yr since menopause, had never received ERT. During the 2-yr study, women not receiving ERT had significant decreases in BMD of the spine -2.3 +/- 0.6%, femoral neck -2.2 +/- 0.8%, and calcaneus -4.7 +/- 0.9%, and in BUA of the calcaneus -14.3 +/- 1.8%. ERT prevented the decreases in BMD at the spine +0.4 +/- 0.6% and calcaneus -2.3 +/- 1.1%, but did not prevent a significant decrease in bone mass at the femoral neck -1.9 +/- 0.8% and BUA at the calcaneus -17.8 +/- 3.2%. Neither group had significant decreases in total hip BMD. This study demonstrates again that ERT prevents the menopause-associated decreases in spine BMD. However, in this group of women, ERT did not prevent loss in femoral neck BMD or BUA. The results suggest that women being treated with estrogen for maintenance of BMD in early menopause need to be monitored to ensure efficacy of therapy, especially in the maintenance of femoral neck BMD.

High implant fracture incidence with Sutter silicone metacarpophalangeal joint arthroplasty.

We performed a retrospective review of Sutter silicone metacarpophalangeal (MP) joint arthroplasties in 34 patients (42 hands, 168 implants) with rheumatoid arthritis. Patients were evaluated at an average of 27 months (minimum follow-up period, 12 months). Twenty percent of the implants were shown to be definitely fractured on final follow-up examination, and 45% followed for more than 3 years were definitely fractured. At the final follow-up examination, the average ulnar drift in intact implants was 11 degrees and in the fractured implants, 23 degrees. However, there was no correlation between implant fracture and patient satisfaction. Eighty percent of patients said they would undergo the procedure again. Because of a significantly higher implant fracture incidence at a relatively shorter follow-up period than that of most studies of silicone MP implants of the Swanson design, we have abandoned the use of the Sutter implant.

Retroperitoneal pseudomeningocele complicated by meningitis following a lumbar burst fracture. A case report.

STUDY DESIGN: This case report demonstrates an unusual complication after anterior decompression and fusion of a lumbar burst fracture. OBJECTIVES: The treatment of this patient involved placement of a computed tomography-guided percutaneous drain and intravenous antibiotics to treat an infected retroperitoneal pseudomeningocele. SUMMARY OF BACKGROUND DATA: A case of an anterior retroperitoneal pseudomeningocele complicated by meningitis is presented. This pseudomeningocele occurred in a patient after an L3 burst fracture associated with a dural laceration. METHODS: The patient was admitted to the authors' trauma unit after a motor vehicle accident with an acute L3 fracture associated with incomplete paraplegia. He underwent an urgent anterior corpectomy, strut grafting, and instrumentation. At surgery, he was noted to have a large anterior dural laceration. After surgery, a large retroperitoneal pseudomeningocele developed that became infected with Staphylococcus epidermidis. RESULTS: After placement of a computed tomography-guided percutaneous drain and intravenous antibiotics, the pseudomeningocele resolved. His anterior fusion healed uneventfully and his neurologic deficit improved dramatically. CONCLUSIONS: A case of an anterior retroperitoneal pseudomeningocele complicated by meningitis is presented. This pseudomeningocele occurred in a patient after an L3 burst fracture associated with a dural laceration. The patient was treated successfully with computed tomography-guided percutaneous drain placement and intravenous antibiotics. He made an excellent functional recovery after a severe neurologic injury.