Modified grade 4 osteotomy for kyphosis due to old osteoporotic vertebral compression fractures: Two case reports

Distal Junctional Failures in Degenerative Thoracolumbar Hyperkyphosis

OBJECTIVE

Degenerative thoracolumbar hyperkyphosis (DTH) is a disease that negatively affects individual health and requires surgical intervention, yet the ideal surgical approach and complications, especially distal junctional failures (DJF), remain poorly understood. This study aims to investigate DJF in DTH and to identify the risk factors for DJF so that we can improve surgical decision-making, and advance our knowledge in the field of spinal surgery to enhance patient outcomes.

METHODS

This study retrospectively reviewed 78 cases (late osteoporotic vertebral compression fracture [OVCF], 51; Scheuermann's kyphosis [SK], 17; and degenerative disc diseases [DDD], 10) who underwent corrective surgery in our institute from 2008 to 2019. Clinical outcomes were assessed using health-related quality of life (HRQOL) measures, including the visual analogue scale (VAS) scores for back and leg pain, the Oswestry disability index (ODI), and the Japanese Orthopaedic Association (JOA) scoring system. Multiple radiographic parameters, such as global kyphosis (GK) and thoracolumbar kyphosis (TLK), were assessed to determine radiographic outcomes. Multivariate logistic regression analysis was employed to identify the risk factors associated with DJF.

RESULTS

HRQOL improved, and GK, TLK decreased at the final follow-up, with a correction rate of 67.7% and 68.5%, respectively. DJF was found in 13 of 78 cases (16.7%), two cases had wedging in the disc (L3-4) below the instrumentation, one case had a fracture of the lowest instrumented vertebrae (LIV), one case had osteoporotic fracture below the fixation, nine cases had pull-out or loosening of the screws at the LIV and three cases (23.1%) required revision surgery. The DJF group had older age, lower computed tomography Hounsfield unit (CT HU), longer follow-up, more blood loss, greater preoperative sagittal vertical axis (SVA), and poorer postoperative JOA and VAS scores (back). The change in TLK level was larger in the non-DJF group. Post-sagittal stable vertebrae (SSV) moved cranially compared with pre-SSV.

CONCLUSION

Age, CT HU, length of follow-up, estimated blood loss, and preoperative SVA were independent risk factors for DJF. We recommend fixation of the two vertebrae below the apex vertebrae for DTH to minimize surgical trauma.

Junctional Kyphosis after Correction with Long Instrumentation for Late Posttraumatic Thoracolumbar Kyphosis: Characteristics and Risk Factors

OBJECTIVE

Junctional kyphosis is a common complication after corrective long spinal fusion for adult spinal deformity. Whereas there is still a paucity of data on junctional kyphosis, specifically among late posttraumatic thoracolumbar kyphosis (LPTK) patients. Thus, the aim of this study was to investigate the characteristics and risk factors of junctional kyphosis in LPTK patients receiving long segmental instrumented fusion.

METHODS

We retrospectively reviewed a cohort of LPTK patients who had received long segmental instrumented fusion (>4 segments) in our center between January 2012 and January 2019. Radiographic assessments included the sagittal alignment, pelvic parameters, bone quality on CT images, and measurements of the cross-sectional area (CSA, cross-sectional area of muscle-vertebral body ratio × 100) and fat saturation fraction (FSF, cross-sectional area of fat-muscle body ratio × 100) of paraspinal muscles. Patients in this study were divided into those with junctional kyphosis or failure (Group J) and those without (Group NJ) during follow-up. Group J included patients with junctional kyphosis (Group JK) and patients with junctional failure (Group JF).

RESULTS

A total of 65 patients (16 males and 49 females, average age 56.5 ± 23.4 years) were enrolled in this study. After (32.7 ± 8.5) months follow-up, 15 patients (23.1%) experienced junctional kyphosis, and four of them deteriorated into junctional failure. Eighty percent (12/15) of junctional kyphosis was identified within 6 months after surgery. In comparison with Group NJ, Group J were older (P = 0.026), longer fusion levels (P < 0.001), greater thoracic kyphosis (P = 0.01), greater global kyphosis (P = 0.023), lower bone quality (P < 0.001), less CSA (P = 0.005) and higher FSF (P <0.001) of paraspinal muscles. Preoperative global kyphosis more than 48.5° (P = 0.001, odds ratio 1.793) and FSF more than 48.4 (P = 0.010, odds ratio 2.916) were identified as independent risk factors of junctional kyphosis. Based on the statistical differences among Group NJ, Group JK and Group JF (P < 0.001), Group JF had lower bone quality than Group NJ (P < 0.001) and Group JK (P = 0.015). In terms of patient-reported outcomes, patients in Group JF had worse outcomes in ODI and VAS scores, and PCS and MCS of SF-36 than Group NJ and group JK CONCLUSION: The prevalence of junctional kyphosis was 23.1% in LPTK patients after long segmental instrumented fusion. Preoperative hyperkyphosis and advanced fatty degeneration of paraspinal muscles were independent risk factors of junctional kyphosis. Patients with lower bone quality were more likely to develop junctional failure.

Surgical options for symptomatic old osteoporotic vertebral compression fractures: a retrospective study of 238 cases

Background

Symptomatic osteoporotic vertebral compression fractures (OVCF) are increasing, as are acute and chronic pain episodes and progressive spinal deformities. However, there are no clear surgical treatment criteria for patients with these different symptoms. Therefore, this study aims to explore the surgical approaches for the treatment of OVCF with different symptoms and evaluate the feasibility of these surgical approaches.

Methods

We retrospectively analyzed 238 symptomatic OVCF patients who entered our hospital from June 2013 to 2016. According to clinical characteristics and imaging examinations, these patients were divided into I-V grades and their corresponding surgical methods were developed. I, old vertebral fracture with no apparent instability, vertebral augmentation; II, old vertebral fracture with local instability, posterior reduction fusion internal fixation; III, old fractures with spinal stenosis, posterior decompression and reduction fusion and internal fixation; IV, old vertebral fracture with kyphosis, posterior osteotomy with internal fixation and fusion; V, a mixture of the above types, posterior osteotomy (decompression) with internal fixation and fusion. Postoperative visual analog score (VAS), oswestry disability index (ODI) scores, sagittal index (SI) and ASIA grades of neurological function were observed.

Results

All 238 patients were followed up for 12–38 months, with an average follow-up of 18.5 months. After graded surgery, the VAS score, ODI score, and vertebral sagittal index SI of 238 patients were significantly improved, and the difference between the last follow-up results and the preoperative comparison was statistically significant (P ˂ 0.05). Besides, the postoperative ASIA grades of 16 patients with nerve injury were improved from 14 patients with preoperative grade C, 2 patients with grade D to 4 patients with postoperative grade D and 12 patients with postoperative grade E.

Conclusion

In this study, we concluded that graded surgery could better treat symptomatic old OVCF and restore spinal stability. This provides clinical reference and guidance for the treatment of symptomatic old OVCF in the future.

[SRS-Schwab grade osteotomy combined with satellite rod for thoracolumbar old osteoporotic fracture with severe kyphosis]

Objective

To evaluate the effectiveness of SRS-Schwab grade Ⅳ osteotomy combined with satellite rod for thoracolumbar old osteoporotic fracture with severe kyphosis.

Methods

Between April 2013 and August 2016, 20 cases of thoracolumbar old osteoporotic fracture with severe kyphosis were treated with SRS-Schwab grade Ⅳ osteotomy combined with satellite rod. All the patients were females, aged 49-71 years (mean, 54.8 years). The disease duration was 6-28 months with an average of 14 months. The T value of bone density was -4.4 to -1.8 (mean, -2.8). The preoperative Cobb angle was (43.0±11.3)°. The vertebral compression fracture segment was T ₁₂ in 9 cases, L ₁ in 8 cases, and L ₂ in 3 cases. Preoperative spinal cord function was evaluated by Frankel classification; there were 5 cases of grade D and 15 cases of grade E. The operation time, intraoperative blood loss, and perioperative complication were recorded. The Cobb angle for kyphosis and sagittal vertical axis (SVA) were recorded beforeoperation, at 3 months after operation, and at last follow-up. Oswestry disability index (ODI) was used to evaluate the effectiveness before operation and at last follow-up, and the evaluation indicators included pain degree, daily life self-care ability, extracting, walking, sitting, standing, sleeping, social activities, and traveling.

Results

The operation time was 180-314 minutes (mean, 226 minutes). The intraoperative blood loss was 390-1 800 mL (mean, 750 mL). All the incisions healed by first intension without incision infection. Twenty patients were followed up 24-52 months, with an average of 30.9 months. During the follow-up period, no significant complication such as correction loss, nail breakage, rod breakage, pseudoarthrosis formation, or proximal and distal junctional kyphosis occurred. All patients were able to walk upright after operation, and the pain relieved significantly at 6 months after operation. Bone fusion achieved at 12 months after operation. The Frankel grade of nerve function improved from grade D to grade E at last follow-up in 5 patients with nerve damage before operation. At last follow-up, the indicator scores of ODI significantly improved when compared with preoperative values ( P<0.05). Cobb angle significantly improved at 3 months after operation and at last follow-up ( P<0.05) when compared with preoperative one, but there was no significant difference in the Cobb angles between 3 months after operation and last follow-up ( P>0.05). There was no significant difference in SVA between pre- and post-operation ( P>0.05).

Conclusion

SRS-Schwab grade Ⅳ osteotomy combined with satellite rod for thoracolumbar old osteoporotic fracture with severe kyphosis is effective in achieving satisfactory clinical outcomes, as well as maintaining correction of kyphosis.