Osteoporosis as a Risk Factor for Intraoperative Complications and Long-term Instrumentation Failure in Patients With Scoliotic Spinal Deformity

Perioperative Evaluation and Management of Children with Osteoporosis and Low Bone Mineral Density

As medical and surgical treatment options for children with osteoporosis expand, multidisciplinary strategies for bone health optimization become more important. Each patient's bone mineral density and fracture history should be interpreted in context. Off-label bisphosphonate use is a standard pharmacologic intervention for children with osteoporosis for optimal bone accrual. It is possible to continue this therapy perioperatively under certain circumstances. The rare side effects (osteonecrosis of the jaw and atypical femur fractures) seem less common in children. Physical therapy, vitamin D supplementation, and other interventions are also important tools for optimal bone health perioperatively and for satisfactory surgical outcomes.

Cost-Effectiveness of Corrective Fusion Surgeries for Adult Spinal Deformities: Does Unexpected Revision Surgery Affect Cost-Effectiveness?

Introduction

Previous research has demonstrated that mid- to long-term health-related quality of life following corrective fusion surgery for adult spinal deformity (ASD) can be improved by appropriate revision surgery. In this study, we aim to compare the cost-effectiveness of corrective fusion surgery for ASD with and without unexpected revision surgery 5 years postoperatively.

Methods

In total, 79 patients with ASD (mean age, 68.7 years) who underwent corrective fusion surgery between 2013 and 2015 were included in this study. Cost-effectiveness was evaluated based on the cost of obtaining 1 quality-adjusted life year (QALY). Patients were divided into two groups according to the presence or absence of unexpected revision surgery following corrective fusion and were subjected for comparison.

Results

As per our study findings, 26 (33%) of the 79 ASD patients underwent unexpected revision surgery during the first 5 years following surgery. Although there was no significant difference in terms of inpatient medical costs at the time of initial surgery for 5 years after surgery between the two groups (no-revision group, revision group; inpatient medical costs at the time of initial surgery: USD 69,854 vs. USD 72,685, P=0.344), the total medical expenses up to 5 years after surgery were found to be higher in the revision group (USD 72,704 vs. USD 104,287, P<0.001). The medical expenses required to improve 1 QALY 5 years after surgery were USD 178,476 in the no-revision group, whereas it was USD 222,081 in the revision group.

Conclusions

Although the total medical expenses were higher in the revision group, no significant difference was observed in the cumulative QALY improvement between the revision and no-revision groups. Moreover, the medical expenses required to improve 1 QALY were higher in the revision group, with a difference of approximately 20%.

Survey on Actual Management of Osteoporosis with the Japanese Medical Data Vision Database in Elderly Patients Undergoing Spinal Fusion

Background: No actual data on spinal fusion and management of osteoporosis in Japan have been reported. The aim of the survey was to investigate pre- and post-operative management of osteoporosis, including testing and prescription, in elderly patients undergoing spinal fusion in Japan. Methods: Medical data on patients aged 65 years or older undergoing spinal fusion from April 2018 to March 2022 were extracted from the medical data vision (MDV) database containing health insurance claims data from Japanese acute care hospitals to investigate fusion area, pre- and post-operative osteoporosis tests (bone mineral density and osteoporosis markers), prescriptions of osteoporosis medications, and other information. Results: The analysis set consisted of 26,959 patients. Annual pre-operative BMD testing rates and osteoporosis markers testing rates were higher than the post-operative rates without significant annual changes. The post-operative prescription rate of osteoporosis medications throughout the target period was approximately two times higher than the preoperative rate. The drug with highest pre- and post-operative prescription rates was teriparatide (TPTD) followed by bisphosphonates, showing that the prescription rate of TPTD proportionally increased with the length of fusion area. Conclusions: It was suggested that patients aged 65 years or older undergoing spinal fusion might receive insufficient osteoporosis tests. Despite no trend in the testing rate with the length of fusion area, some tendency was observed in the selection of osteoporosis medications. In patients with osteoporosis undergoing spinal fusion, early examination, diagnosis, and therapeutic intervention may improve the prognoses, and solid testing and prescriptions are therefore expected.

Surgical Strategies for Tuberculous Spondylodiscitis With Severe Osteoporosis: A Case Illustrating the Challenges of Delayed Intervention

Tuberculous spondylodiscitis (Pott's spine) is a complex extrapulmonary manifestation of tuberculosis (TB) that poses significant medical challenges, characterized by vertebral destruction affecting approximately 2% of all TB cases. The management of this condition involves a multidisciplinary approach, with surgical intervention indicated for specific cases, including those with neurological complications, spinal instability, and kyphosis. We report a case of a 49-year-old female with a confirmed diagnosis of tuberculous spondylodiscitis who had undergone eight months of tuberculostatic therapy. She was referred for neurosurgical consultation due to uncontrollable axial pain, despite favorable clinical and imaging responses, which had rendered her immobile for six months. Imaging revealed a complete collapse of the L5 vertebral body, and a complementary dual x-ray absorptiometry (DEXA) scan demonstrated severe osteoporosis. A two-stage surgical approach was chosen to address her condition, involving corpectomy through an anterior approach, followed by lumbopelvic stabilization. Postoperative recovery was uneventful, with progressive improvement in pain and mobility. This case highlights the challenges of managing tuberculous spondylodiscitis and underscores the significance of early detection to prevent complications like severe osteoporosis. In this case, delayed referral for surgery following an extended period of immobility added complexity to an already difficult case. The severe osteoporosis, with a t-score of -5.7, had a substantial impact on surgical planning, leading to a more robust approach to arthrodesis with substantial lumbopelvic instrumentation in order to mitigate the risks associated with implant failure. This case shows that timely intervention and a comprehensive multidisciplinary approach are essential for the effective management of tuberculous spondylodiscitis, especially in cases complicated by severe osteoporosis.

Which Bone Mineral Density Measure Offers a More Reliable Prediction of Mechanical Complications in Adult Spinal Deformity Surgery: Hounsfield Units or DEXA Scan?

OBJECTIVE

In patients undergoing adult spinal deformity (ASD) surgery, we sought to: (1) determine the relationship between dual-energy x-ray absorptiometry (DEXA)-measured bone mineral density (BMD), T-scores, and Hounsfield units (HU), and (2) compare the ability of DEXA-measured BMD, T-scores, and HU to predict mechanical complications and reoperations.

METHODS

A single-institution retrospective cohort study was undertaken for cases from 2013 to 2017.

INCLUSION CRITERIA

≥5-level-fusion, sagittal/coronal deformity, and 2-year follow-up. Multivariable regression controlled for age, body mass index, receiving anabolic medications, and postoperative sagittal vertical axis and pelvic-incidence lumbar-lordosis mismatch. A subanalysis was performed for osteopenic patients (-1 < T-score < -2).

RESULTS

Of 145 patients undergoing ASD surgery, 72 (49.6%) had both preoperative DEXA and computed tomography scans. Mean DEXA-measured BMD was 0.91 ± 0.52 g/cm2, mean T-score was -1.61 ± 1.03, and mean HU was 153.5 ± 52.8. While no correlation was found between DEXA-measured BMD and HU (r = 0.17, P = 0.144), T-score and HU had a weakly positive correlation (r = 0.31, P = 0.007). Mechanical complications occurred in 48 (66.7%) patients, including 27 (37.5%) proximal junctional kyphosis (PJK), 1 (1.4%) distal junctional kyphosis, 5 (6.9%) implant failure, 30 (41.7%) rod fracture/pseudarthrosis, 42 (58.3%) reoperations, and 16 (22.2%) reoperations due to PJK. No association was found between DEXA-measured BMD or T-scores with mechanical complications or reoperations. While univariate regression showed a significant association between lower HU and PJK (OR 0.98, 95%CI 0.97-0.99, P = 0.011), the significance was lost after multivariable analysis. When considering osteopenic patients (n = 37), only DEXA-measured BMD was an independent risk factor for PJK (OR 0.01, 95%CI 0.00-0.09, P = 0.017), with a threshold of 0.82 g/cm2 (AUC 0.70, 95%CI 0.53-0.84, P = 0.019).

CONCLUSIONS

Poor correlation was found between the 3 BMD modalities. DEXA-measured BMD may be superior to T-scores and HU in predicting PJK among patients with osteopenia with a threshold of BMD <0.82 g/cm2.

Comparing zero-profile and conventional cage and plate in anterior cervical discectomy and fusion using finite-element modeling

Conventional cage and plate (CCP) implants usually used in ACDF surgery, do have limitations such as the development of postoperative dysphagia, adjacent segment degeneration, and soft tissue injury. To reduce the risk of these complications, zero-profile stand-alone cage were developed. We used finite-element modeling to compare the total von Mises stress applied to the bone, disc, endplate, cage and screw when using CCP and ZPSC implants. A 3-dimensional FE (Finite element) analysis was performed to investigate the effects of the CCP implant and ZPSC on the C3 ~ T1 vertebrae. We confirmed that the maximum von Mises stress applied with ZPSC implants was more than 2 times greater in the endplate than that applied with CCP implants. The 3D analysis of the ZPSC model von Mises stress measurements of screw shows areas of higher stress in red. Although using ZPSC implants in ACDF reduces CCP implant-related sequalae such as dysphagia, we have shown that greater von Mises stress is applied to the endplate, and screw when using ZPSC implants. This may explain the higher subsidence rate associated with ZPSC implant use in ACDF. When selecting an implant in ACDF, surgeons should consider patient characteristics and the advantages and disadvantages of each implant type.