Comparative supine-sitting lateral radiographs identifying incident osteoporotic vertebral fractures

Effects of Weekly Teriparatide Administration for Vertebral Stability and Bony Union in Patients with Acute Osteoporotic Vertebral Fractures

Study Design

An open-label, non-randomized prospective study.

Purpose

Teriparatide (TPTD) is known to be an antiosteoporotic agent that may accelerate the healing of fractures. This study was designed to investigate the effect of once-weekly TPTD administration on vertebral stability and bony union after acute osteoporotic vertebral fracture (OVF).

Overview of Literature

Once-weekly TPTD administration can lead to early vertebral stability and promote bony union of fractured vertebrae in patients with severe osteoporosis.

Methods

Forty-eight subjects with acute OVF were assigned to receive activated vitamin D3 and calcium supplementation or onceweekly subcutaneous injection of TPTD (56.5 μg) in combination with activated vitamin D3 and calcium supplementation for 12 weeks. Vertebral stability was assessed using lateral plain radiography. Vertebral height at the anterior location (VHa) and the difference in VHa {ΔVHa=VHa (supine position)−VHa (weight-bearing position)} were measured at baseline and 12 weeks after starting treatment. Bony union was defined as the absence of a vertebral cleft or abnormal motion (ΔVHa >2 mm).

Results

Although not significant, ΔVHa, indicating vertebral stability, tended to be lower in the TPTD group at 12 weeks (p =0.17). As for subjects with severe osteoporosis, ΔVHa at 12 weeks was significantly lower in the TPTD group than in the control group (mean ΔVHa: control group, 3.1 mm (n=15); TPTD group, 1.4 mm (n=16); p =0.02). The rate of bony union was significantly higher in the TPTD group than in the control group (control group, 40%; TPTD group, 81%; p =0.03).

Conclusions

Once-weekly TPTD administration may facilitate early bony union after acute OVF accompanied by severe osteoporosis.

Efficacy of the dynamic radiographs for diagnosing acute osteoporotic vertebral fractures

We investigated the efficacy of dynamic radiographs for diagnosing acute osteoporotic vertebral fractures (OVFs) compared with supine radiographs or sitting radiographs alone. Evaluation of the dynamic radiographs was superior to the other evaluations. Dynamic radiographs provide a convenient and useful method of diagnosing acute OVFs.

INTRODUCTION

Identifying acute OVFs on plain radiographs is difficult. We studied a new approach to identify acute OVFs on the basis of fracture mobility.

METHODS

We performed a retrospective radiographic analysis of 472 acute OVFs (<3 weeks after onset), which were diagnosed on the basis of magnetic resonance imaging of T5 through L5 (a total of 5,239 vertebrae). Supine lateral radiographs were compared with sitting lateral radiographs to determine the presence or absence of mobility. Vertebrae showing changes in the vertebral body height were diagnosed as acute OVFs. We analyzed the diagnostic accuracy on the basis of comparative supine and sitting lateral radiographs and compared it with that of radiographs obtained in the supine or the sitting position alone.

RESULTS

Of the 472 acute OVFs diagnosed, 313 (66 %) exhibited vertebral mobility on supine lateral and sitting lateral radiographs. Correct diagnoses of acute OVFs or no acute OVFs were made in 4,883 vertebrae. There were 159 unreadable OVFs (3 %), and 197 previous OVFs (4 %) were misdiagnosed as acute OVFs. The sensitivity was 66 % and the specificity was 96 %. Evaluation of the mobility of acute OVFs in the supine and the sitting position was superior to evaluation using radiographs in either the supine or the sitting position alone.

CONCLUSIONS

Dynamic radiographs provide a convenient way to identify acute OVFs.

Union rates and prognostic variables of osteoporotic vertebral fractures treated with a rigid external support

Object

External supports serve as a traditional treatment option for osteoporotic vertebral fractures (OVFs). However, the role of external supports in the treatment of OVF remains inconclusive. The purpose of this study was to determine the role of a rigid external support in the healing of OVFs by prospectively evaluating union (fracture settling) rates and prognostic variables for patients suffering from an incident OVF.

Methods

Fifty-five patients with acute back pain were enrolled in this study after being diagnosed with an OVF based on MRI findings. Patients were treated using a plastic thoracolumbosacral orthosis (TLSO) and underwent follow-up at 2, 3, and 6 months. Vertebrae were referred to as “settled” when there was no dynamic mobility on sitting lateral and supine lateral radiographs. At the time of the 3- and 6-month follow-up visits, the patients were divided into 2 groups, the “settled group” and the “unsettled group.” Patients in these groups were compared with regard to clinical and radiographic features.

Results

Of the 55 patients enrolled, 53 patients were followed up for 6 months. There were 14 men and 39 women with an average age of 75.3 years. Fracture settling of the affected vertebra was defined in 54.7% of the patients at 2 months, in 79.2% at 3 months, and in 88.7% at 6 months. All 5 components of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire improved significantly both at 3 months and 6 months. Patients in the unsettled group exhibited a statistically greater likelihood of having fractures at the thoracolumbar junction, Type A3 fractures, and fractures with a diffuse low-intensity area on T2-weighted MRI studies at 3 months. In contrast, at 6 months, the only statistically significant difference between the groups was patient age.

Conclusions

The biomechanical disadvantages of OVFs (location, type, and size) adversely influencing the fracture healing were overcome by the treatment using a TLSO within 6 months. The authors' findings show that a TLSO plays a biomechanical role in the healing of OVFs.