Indication for Partial Vertebral Osteotomy and Realignment in Posterior Spinal Fixation for Osteoporotic Thoracolumbar Vertebral Collapse with Neurological Deficits

Biomechanical and clinical evaluation of PSO, modified PSO and VCR treating OVCF kyphosis: a finite element analysis

Objective

To confirm the effect of surgery on spinal column biomechanics and to provide theoretical support for the advantages and disadvantages of different surgical methods and their clinical efficacy.

Methods

33 continuous patients with no significant difference in risk factors related to the mechanical complications were enrolled in this retrospective study. Sagittal parameters were measured in the pre-, post-operative and following-up lateral radiograph of spine. An finite element (FE) model was created using CT scanning from a female volunteer with osteoporotic vertebral compression fracture (OVCF) with solely kyphosis. Pedicle subtraction osteotomy (PSO), vertebral column resection (VCR) and modified PSO(mPSO) for OVCF were simulated on FE model. Stress distribution and deformation of the FE model were measured.

Results

Clinical - All differences in preoperative spinal sagittal parameters were not statistically significant. mPSO showed it is superior to PSO and VCR in multiple postoperative and following-up spinal sagittal parameters. The operation duration and intraoperative blood loss of mPSO are less than the other two. For postoperative mechanical complications, no statistically significant differences were observed. Biomechanical - Six operating conditions (flexion, extension, left/right bending, left/right twisting) for each post-operative FE model have been examined. In most conditions, the displacement of mPSO is similar to that of PSO, with both larger than that of VCR. All the maximum equivalent stress on the vertebral body is within the safe range. The stress is mainly distributed on the T10 vertebral body and the fixed vertebral body L2, while the stress of VCR is greater than that of mPSO and PSO. The intervertebral disc pressure is highest in VCR, followed by PSO, and lowest in mPSO under all conditions. The maximum pressure on the intervertebral discs is located between T10 and T11.

Conclusion

The finite element analysis showed that mPSO has a similar spine stability to PSO, and possibly creates a better environment for bone-to-bone fusion and prevents adjacent segments degeneration. Combined with its less surgical risks, we believe that the modified pedicle subtraction osteotomy may be an appropriate strategy for indicated cases of OVCF.

Modified posterior osteotomy for osteoporotic vertebral collapse with neurological dysfunction in thoracolumbar spine: a preliminary study

OBJECTIVE

The risk of osteoporotic vertebral collapse (OVC) associated with delayed neurological dysfunction (DND) is substantial, and performing surgery for this condition in elderly patients presents challenges. The focus of the current research is on simplifying surgical procedures while maintaining their effectiveness. This study was designed to contribute clinical data supporting the use of modified posterior osteotomy for treating thoracolumbar OVC with DND. The study compares perioperative clinical parameters, imaging data characteristics, and changes in efficacy outcome indicators to provide evidence for the advancement of this technique.

METHODS

A total of 12 patients diagnosed with osteoporotic vertebral collapse and neurological dysfunction were included in the study. All patients underwent modified posterior osteotomy. Data regarding perioperative and radiological parameters as well as complications such as surgery duration, blood loss, ASIA grade, VAS, ODI, regional kyphosis angle (RKA), anterior vertebral height ratio (AVHr), and spinal canal clearance ratio (SCCr), were collected retrospectively. These parameters were then analysed to evaluate the clinical efficacy and safety of the modified posterior osteotomy technique.

RESULTS

A total of 12 patients were included in the study, with a mean age of 65.5 ± 9.7 years. The average follow-up period was 29.4 ± 5.0 months. The mean operative blood loss was 483.3 ± 142.0 ml, and the average operative time was 3.7 ± 0.7 h. The visual analogue scale (VAS) score decreased from a preoperative value of 5.8 ± 0.7 to a final follow-up value of 1.3 ± 0.8 (P < 0.05), indicating a significant improvement in pain. The ODI decreased from 65.2 ± 6.0 before surgery to 20.5 ± 7.0, indicating a decrease in disability, and the postoperative neurological function showed a significant improvement. Correction of the RKA was observed, with the angle changing from 35.8 ± 10.8° before surgery to 20.0 ± 3.5° after surgery and to 22.5 ± 3.1° at the final follow-up. Similarly, correction of the AVHr was observed, with the height changing from 39.3 ± 18.0 to 63.0 ± 14.3 after surgery and to 53.9 ± 8.9 at the final follow-up. Correction of the SCCr was also observed, with the ratio changing from 54.9 ± 5.4 to 68.1 ± 5.3 after surgery and to 68.68 ± 6.76 at the final follow-up.

CONCLUSIONS

Posterior modified osteotomy is an effective treatment for thoracolumbar osteoporotic fractures with OVC combined with DND. It can significantly preserve vertebral height, increase vertebral canal volume, correct kyphotic angle, and improve postoperative neurological function. The simplified osteotomy also offers advantages in terms of operating time, blood loss, postoperative VAS score, and improvement in lumbar function.

Novel Surgical Strategy for Treating Osteoporotic Vertebral Fractures with Cord Compression

Objectives

Treatment for osteoporotic vertebral fracture (OVF) with cord compression is challenging and it usually requires surgical interventions to decompress nerves and restore spinal sequences. To describe a novel surgical strategy for treating OVFs with cord compression.

Methods

This is a single‐center retrospective analysis. The inclusion criteria were Frankel grade C‐E, single level T₁₀‐L₂. Between January 2008 and December 2016, a total of 56 OVF patients (47 females and nine males, with an average age of 72 years (66–88 years), comprising of eight grade C, 23 grade D, and 25 grade E patients) were enrolled. The treatment algorithm included preoperative evaluation by MRI, extension CT, and radiography to classify the OVFs as type 1.1 (reducible, stable; n = 13), type1.2 (reducible, unstable; n = 16), type 2 (irreducible; n = 19) or type 2M (modifier; n = 8). Vertebroplasty (VP)/kyphoplasty (KP) was applied in type 1.1. VP/KP with posterior fixation and posterolateral fusion was applied in type 1.2. And additional laminectomy/osteotomy was used in type 2, except in a modifier group (2M) where same procedure as applied for type 1.2 was used. VAS, ODI, Cobb angle, Frankel functional grade, and complications were recorded.

Results

Thirteen cases were classified as type 1.1, 16 cases as type 1.2, 19 cases as type 2, and eight cases as type 2M. The follow‐up period was 38.9 months (range, 24–108 months). All patients were followed‐up in at least 24 months, in which time four patients died, two patients were lost at the last follow‐up, and 50 patients completed the full study. The total VAS and ODI improved from 8 (7, 9) and 75.5% (67.2%, 80.0%) preoperatively to 2 (1, 3) and 31% (24.0%, 37.0%) on conclusion, respectively (P < 0.01). The local kyphotic angle was corrected from 22.3° (17.1°, 33. 8°) preoperatively to 10.4° (6.4°, 15.3°) on conclusion (P < 0.01). Twenty‐three patients had achieved neurological recovery on conclusion (42E, 8D, P < 0.01). Asymptotic cement leakage was observed in 17/56 cases (30.4%), 6/56 in the affected vertebra (10.7%), and 24/330 in the screw trajectory (7.3%). At 2 years postoperatively, 11 new VFs had occurred in nine patients (16.1%), including VFs in nine adjacent segments that all occurred within 1 year after surgery. No cement migration or implant failure was noted.

Conclusion

The novel surgical strategy for treating OVFs with cord compression consists of the most tailored and least invasive treatment for each patient. The positive mid‐ and long‐term clinical and radiological outcomes observed could represent a step forward in devising the proposed algorithm.

Outcomes Reported After Surgery for Cauda Equina Syndrome: A Systematic Literature Review

STUDY DESIGN

This is a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

OBJECTIVE

To assess the outcomes reported in trials and observational studies of surgery for cauda equina syndrome (CES), and to inform the development of a core outcome set.

SUMMARY OF BACKGROUND DATA

Scoping searches revealed that there were inconsistencies in which outcomes were reported and how they were measured in research studies for patients who had undergone surgery for CES.

METHODS

Ovid Medline, Embase, CINAHL Plus, and trial registries were searched from January 1, 1990 to September 30, 2016 with the term "cauda equina syndrome." Inclusion and exclusion criteria were applied according to study design, diagnosis, procedure, publication date, language, and patient age. Data extracted included demographics, study design, the outcomes reported, and their definition. We also assessed variation in the use of terminology for each outcome domain.

RESULTS

A total of 1873 articles were identified, of which 61 met the inclusion criteria. Of these, 737 outcomes reported verbatim were categorized into 20 core outcome domains and 12 subdomains with a range of 1 to 141 outcomes per outcome domain or subdomain. The most commonly reported outcomes were bladder function (70.5%), motor function (63.9%), and sensation (50.8%). Significant variation in the terms used for each outcome was documented, for example, bladder function outcome domain had 141 different terms.

CONCLUSION

There is significant heterogeneity in outcomes reported for studies after surgery for CES patients. This indicates a clear need for the development of a core outcome set, which has been registered as number 824 on the COMET (Core Outcome Measure in Effectiveness Trials) database.

LEVEL OF EVIDENCE

1.