ENHANCED REPAIR WITH TERIPARATIDE OF SYNTHESIZED FEMORAL NECK FRACTURES IN OSTEOPOROTIC ELDERLY: NEW THERAPEUTIC PERSPECTIVES

Abstract

Background: Despite of advanced implant modifications and surgical techniques, internal fixation of proximal femur fractures in osteoporotic elderly is conditioned by high rate of complicated healing and implant failure. The deterioration in micro architecture and the loss in mechanical properties of trabecular bone due to impaired bone turnover must be treated. Teriparatide(TPTD) has been demonstrated to improve of new bone formation in both trabecular and cortical envelopes and thus bone strength. Moreover in a number of fracture models on anims stimulates the healing process generating larger total callus volume. The aim of this study was to determine if bone anabolic agent (TPTD) may enhance the repair of femoral neck fractures in osteoporotic elderly synthesized with internal fixation and prevent complications.

Study Design: 31 compliant females between 57 and 95 years-old presenting a lateral femoral neck fracture was considered. At admission in orthopaedic unit they were undergone to haematochemical exams extended to bone turnover markers, lumbar and contralateral femoral BMD measured by DXA and x-rays of dorsal-lumbar spine. They were divided in two subgroups on the basis of concomitant vertebral compression fracture (VCF) discovered. To the patients with VCF was administrated daily subcutaneous injection of 20 microgr. of TPTD (TPTD group). Both groups received 1g of calcium carbonate and 1200 IU of colecalciferol daily from the first post-operative week. All the patients repeated x-rays of affected segments and bone turnover markers at 1,3,6 months. The pain was detected through a self-reported visual analogue scale (VAS). The functional outcome was evaluated in term of hospitalization, of walking on two crutches and their abandon.

Results: At admission serum 25(OH) vitamin D concentration was at lower levels but the supplementation was sufficient to normalize even if in TPTD group it remained lower than control. In TPTD group the bone formation markers were significantly increased at 1st month and peaked at 3rd month without an increase in bone resorption markers. In TPTD group the callus formation was radiologically evident from 1st month followed by consolidation within 3rd month for all. While in control group the fracture repair was less detectable at 3rd month with heterogeneous trend: one needed a re-operation, four were afflicted by delayed union and another one by VCF. Moreover earlier walking and abandon of crutches in TPTD group was related to significant decrease of pain. At 6th month BMD is significantly increased only in TPTD group.

Conclusions: In osteoporotic femoral neck fractures the demonstration of enhanced repair, the stability of the osteosynthesis, the pain relief and the recovery of autonomy in walking obtained with adjuvant anabolic therapy (TPTD) opens new therapeutic perspectives.