Biomechanical specimen assessment by low dose biplanar X-ray study of fusion constructions using a posterior lumbar cage with integrated anchors and posterior adjunctive fixators.

The objective was to compare L4/5 range of motions of fusion constructs using anchored cages. Twelve human cadaveric spine were tested in intact condition, and divided into TLIF and PLIF groups. Testing consisted in applying pure moments in flexion-extension, lateral bending and axial rotation. The computation of intersegmental motion was assessed using 3 D biplanar radiographs. In TLIF group, the addition of contralateral transfacet decreased flexion-extension motion (39%; p = 0.036) but without difference with the ipsilateral pedicle screw construction (53%; p = 0.2). In PLIF group, the addition of interspinous anchor reduced flexion-extension motion (12%; p = 0.036) but without difference with the bilateral pedicle screw construction (17%; p = 0.8).

Medicoeconomic evaluation of total disc replacement based on French National Health Care System data.

INTRODUCTION: Total disc replacement (TDR) has existed since 1984 but is not covered by the French national healthcare system (Sécurité Sociale). The present study assessed clinical outcomes, and also pre-, peri- and postoperative treatment costs. HYPOTHESIS: Surgical management of low back pain (LBP) provides medical and economic benefit. MATERIALS AND METHODS: A prospective study recruited 19 patients in the Nice University Hospital Center (France); mean age, 41 years; 15 female. Inclusion criteria were: age less than 60 years; chronic low back pain (LBP) with single-segment discopathy; work related injuries and patients not covered under the General provision of the Sécurité Sociale were excluded. VAS, Oswestry and SF36 scores and return to work capability were analyzed. The local national health insurance branch office (Caisse Primaire d'Assurance Maladie [CPAM]) provided detailed coverage data for a 39-month period around the operation. RESULTS: Revision surgery was required for one instance of vertebral fracture. Preoperative follow-up was 14 months, postoperative FU 21 months and the perioperative period 4 months. LBP and quality of life showed improvement. Seventy-nine percent of patients reported satisfaction, 59% returned to work, and 84% had leisure activity. Total CPAM payout (reimbursement) was €399,082. Daily sickness benefit and disability compensation were the main cost items. Mean TDR cost per patient was €6833. Mean reimbursements were 19% lower post- than preoperatively. Pre- and postoperative clinical results did not correlate, while pre- and postoperative reimbursement costs did, as did cost and postoperative clinical status (r=-0.72). Preoperative cost was a predictive factor for postoperative clinical result. DISCUSSION: TDR achieves favorable medicoeconomic results. LEVEL OF EVIDENCE: III: case-control study.