6-Year follow-up of ventral monosegmental spondylodesis of incomplete burst fractures of the thoracolumbar spine using three cortical iliac crest bone grafts

[Current surgical treatment concepts for traumatic thoracic and lumbar vertebral fractures in adults with good bone quality]

The surgical treatment of traumatic vertebral body fractures in patients with good bone quality is controversially discussed. The data situation is unclear and only of limited help due to mainly insufficient evidence. The surgical measures include an axially aligned reduction and an osteosynthesis which is stable under load so that immediate mobilization of the patient is possible. This requires anatomical restoration of the alignment and the biomechanical challenge of fracture healing or fusion in the correct position without relevant loss of reduction must be taken into account. The aim should be the lowest possible loss of function. In the case of existing or impending neurological deficits it is crucial to prevent deterioration of the neurological situation and to achieve the prerequisites for recovery. Posterior stabilization primarily plays the decisive role in the operative treatment. If possible, this should be a minimally invasive procedure and over short distances. For bisegmental treatment monoaxial screws and the use of index screws improve construct stability. In addition, stable cobalt rods should be used as 5mm longitudinal support. Special minimally invasive reduction instruments are helpful in restoring the sagittal and coronal relationships. The indications for an additional ventral column depend on the rigidity of the posterior stabilization, the extent of the injury of the anterior column and the intervertebral disc. Anterior fusion can often be delayed or avoided altogether, depending on the course with corresponding clinical signs.

Long-term results after thoracoscopic anterior spondylodesis with or without posterior stabilization of unstable incomplete burst fractures of the thoracolumbar junction: a prospective cohort study

Background

Minimally invasive, thoracoscopic anterior spondylodesis (MIAS) is an established treatment for burst fractures of the thoracolumbar spine. Good restoration of the local sagittal alignment and good functional results have been reported. The aim of this study was to evaluate long-term results of MIAS in patients with incomplete burst fractures and to analyze the influence on global sagittal alignment, clinical outcomes, and adjacent segment degeneration.

Methods

From 2002 to 2003, 18 patients were treated with MIAS for incomplete thoracolumbar burst fractures. Mono-segmental spondylodesis was performed with an iliac crest bone graft and bisegmental spondylodesis with a titanium cage. In this single-center prospective cohort study, 15 patients were available for follow-up (FU) after an average of 12.9 years (12.1–14.4). Seven patients were treated with a combined anterior and posterior instrumentation and eight patients with anterior spondylodesis only. The primary clinical outcome parameter was the Oswestry Disability Index (ODI); secondary parameters were the Short Form 36 (SF36) and the visual analog scale (VAS spine). Full spine radiographs were assessed for bisegmental Cobb angle, alignment parameters, and signs of adjacent segment degeneration (ASD).

Results

ODI evaluation showed a mean impairment of 11.7% with minimal limitations in 13 patients. Neither a significant deterioration over time nor significant differences between both therapy strategies were found in the clinical scores at the latest follow-up. The mean bisegmental increase of regional malalignment of reduction was 8.8° (± 7.3°) with no significant correlation to any clinical outcome scores. The majority of patients had no signs of adjacent segment degeneration. Two patients showed minor radiologic changes. All patients had a balanced sagittal spine profile.

Conclusions

In conclusion, MIAS leads to good clinical results with—in majority—minimal spine-related impairment at the latest follow-up. No significant deterioration at 12-year FU was detectable compared to the 6-year results for the SF36 and VAS spine scores. There was no association between sagittal alignment, clinical outcome scores, and ASD.

Trial registration

The study was retrospectively registered in the German Clinical Trials Register (Nr.00015656).

Monosegmental anterior column reconstruction using an expandable vertebral body replacement device in combined posterior-anterior stabilization of thoracolumbar burst fractures

INTRODUCTION

In combined posterior-anterior stabilization of thoracolumbar burst fractures, the expandable vertebral body replacement device (VBRD) is typically placed bisegmentally for anterior column reconstruction (ACR). The aim of this study, however, was to assess feasibility, outcome and potential pitfalls of monosegmental ACR using a VBRD. In addition, clinical and radiological outcome of monosegmental ACR was related to that of bisegmental ACR using the same thoracoscopic technique.

METHODS

Thirty-seven consecutive neurologically intact patients with burst fractures of the thoracolumbar junction (T11-L2) treated by combined posterior-anterior stabilization were included. Monosegmental ACR was performed in 18 and bisegmental ACR in 19 patients. Fracture type and extent of vertebral body comminution were determined on preoperative CT scans. Monosegmental and bisegmental kyphosis angles were analyzed preoperatively, postoperatively and at final radiological follow-up. Clinical outcome was assessed after a minimum of 2 years (74 ± 45 months; range 24-154; follow-up rate 89.2%) using VAS Spine Score, RMDQ, ODI and WHOQOL-BREF.

RESULTS

Monosegmental ACR resulted in a mean monosegmental and bisegmental surgical correction of - 15.6 ± 7.7° and - 14.7 ± 8.1°, respectively. Postoperative monosegmental and bisegmental loss of correction averaged 2.7 ± 2.7° and 5.2 ± 3.7°, respectively. Two surgical pitfalls of monosegmental ACR were identified: VBRD positioning (1) onto the weak cancellous bone (too far cranially to the inferior endplate of the fractured vertebra) and (2) onto a significantly compromised inferior endplate with at least two (even subtle) fracture lines. Ignoring these pitfalls resulted in VBRD subsidence in five cases. When relating the clinical and radiological outcome of monosegmental ACR to that of bisegmental ACR, no significant differences were found, except for frequency of VBRD subsidence (5 vs. 0, P = 0.02) and bisegmental loss of correction (5.2 ± 3.7° vs. 2.6 ± 2.5°, P = 0.022). After exclusion of cases with VBRD subsidence, the latter did not reach significance anymore (4.9 ± 4.0° vs. 2.6 ± 2.5°, P = 0.084).

CONCLUSIONS

This study indicates that monosegmental ACR using a VBRD is feasible in thoracolumbar burst fractures if the inferior endplate is intact (incomplete burst fractures) or features only a single simple split fracture line (burst-split fractures). If the two identified pitfalls are avoided, monosegmental ACR may be a viable alternative to bisegmental ACR in selected thoracolumbar burst fractures to spare a motion segment and to reduce the distance for bony fusion.

Temporary Percutaneous Instrumentation and Selective Anterior Fusion for Thoracolumbar Fractures

STUDY DESIGN

Prospective clinical trial in thoracolumbar trauma with 5-year follow-up.

OBJECTIVE

To analyze clinical and radiographic outcomes of minimal invasive surgery, and the rational of circumferential fracture treatment with regard to age, degenerative changes, bone mineral density, and global sagittal balance.

SUMMARY OF BACKGROUND DATA

Non-neurologic fractures with anterior column defect can be treated by posterior percutaneous instrumentation and selective anterior fusion. After consolidation, instrumentation can be removed at 1 year to provide mobility in non-fused segments.

METHODS

Fifty-one patients, 47 (18-75) years, were operated for A2, A3, or B-type fractures. Visual analog scale (VAS) for back pain and Oswestry Disability Index (ODI) were assessed. Radiographic measurements were: sagittal index, regional kyphosis, T4-T12 kyphosis, L1-S1 lordosis, pelvic incidence, pelvic tilt, sacral slope, and T9 tilt. Anterior fusion and facet joints were analyzed on computed tomography (CT) at 1 year.

RESULTS

The ODI was 8.8 before accident, 35.4 at 3 months, 17.8 at 2 years, 14.4 at 5 years. The VAS was 2.0 at 3 months and 1.0 at 5 years. The sagittal index was 18.0° preoperatively and 1.0° at 3 months (P < 0.0001). A loss of reduction of 1.1° occurred after implant removal (P = 0.009). Global sagittal balance remained unchanged. Ten patients with osteopenia or osteoporosis had a worse ODI: 24.7 versus 11.9 (P = 0.016), and a greater loss of correction: 4.9° versus 1.3° (P = 0.007). Cages filled with cancellous bone from the fractured vertebra fused regularly. Spontaneous facet joint fusions were observed in two patients at the fracture level in B-type injuries.

CONCLUSION

Percutaneous instrumentation and selective anterior fusion using autologous bone and mesh cages lead to high fusion rates, which provided good long-term clinical results in younger patients with thoracolumbar fractures. Sagittal alignment was maintained after instrumentation removal without damaging paravertebral muscles. Outcomes were worse in elderly patients presenting osteopenia or osteoporosis.

LEVEL OF EVIDENCE

3.

Six-year outcome of thoracoscopic ventral spondylodesis after unstable incomplete cranial burst fractures of the thoracolumbar junction: ventral versus dorso-ventral strategy

PURPOSE

The purpose of this study is to determine the long term-results after thoracoscopic spondylodesis particularly with respect to a ventral versus dorso-ventral treatment strategy.

METHODS

In this prospective cohort study, a follow-up examination was performed in 19 patients (seven men, 12 women, average age: 37.7 years, follow-up rate: 79 %), six years after ventral thoracoscopic spondylodesis of unstable, incomplete burst fractures. Nine patients received a ventral monosegmental spondylodesis with iliac crest bone graft. The other ten cases were treated dorso-ventrally, five undergoing a ventral monosegmental treatment with iliac crest bone graft; the other five a ventral bisegmental treatment with expandable titanium cage.

RESULTS

The complication rate was 15.7 %, the rate of revision of 10.5 %. No complication was related to the ventral thoracoscopic approach, whereas all of them were related to the iliac crest bone graft. The operative bisegmental kyphotic reduction was higher in the dorso-ventrally treated group. Afterwards, the loss of reduction was similar in both study groups. The mean VAS spine score summed up to more than 80 in both groups. The mean PCS scores were comparable to a normal healthy collective of the same age.

CONCLUSIONS

The ventral thoracoscopic approach to the spine seems to be a safe therapeutic strategy. A dorso-ventral treatment concept goes along with a higher operative reduction potential.