Cost-utility Analysis of Neoadjuvant Teriparatide Therapy in Osteopenic Patients Undergoing Adult Spinal Deformity Surgery

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.

Transpedicular injection of rhBMP-2 with β-tricalcium phosphate to reduce the proximal junctional kyphosis after adult spinal deformity correction: preliminary study

The aim of this preliminary study was to assess the impact of injecting recombinant human bone morphogenetic protein-2 (rhBMP-2) with β-tricalcium phosphate (β-TCP) carrier into the uppermost instrumented vertebra (UIV) during surgery to prevent the development of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). The 25 patients from study group had received 0.5 mg rhBMP-2 mixed with 1.5 g β-TCP paste injection into the UIV during surgery. The control group consisted of 75 patients who underwent surgery immediately before the start of the study. The incidences of PJK and PJF were analyzed as primary outcomes. Spinopelvic parameters and patient-reported outcomes were analyzed as secondary outcomes. Hounsfield unit (HU) measurements were performed to confirm the effect of rhBMP-2 with β-TCP on bone formation at preoperative and postoperative at computed tomography. PJK and PJF was more occurred in control group than study group (p = 0.02, 0.29, respectively). The HU of the UIV significantly increased 6 months after surgery. And the increment at the UIV was also significantly greater than that at the UIV-1 6 months after surgery. Injection of rhBMP-2 with β-TCP into the UIV reduced PJK and PJF rates 6 months after surgery with new bone formation.

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.

Preoperative Optimization: Risk Factors for Perioperative Complications and Preoperative Modification

Adult spinal deformity (ASD) is common and the complication rate in ASD surgery is high due to its invasiveness. There are several factors that increase the risk of complications with ASD surgery. These include age, past medical history, frailty, osteoporosis, or operative invasiveness. Risk factors for perioperative complications can be categorized as modifiable and non-modifiable. The purpose of this article is to present the current available evidence on risk factors for perioperative complications, with a focus on frailty, osteoporosis, surgical site infection prevention, and hip-spine syndrome. In addition, we present the latest evidence for patient-specific surgical risk assessment and surgical planning.

Assessing the influence of modifiable patient-related factors on complication rates after adult spinal deformity surgery

Aims

Postoperative complication rates remain relatively high after adult spinal deformity (ASD) surgery. The extent to which modifiable patient-related factors influence complication rates in patients with ASD has not been effectively evaluated. The aim of this retrospective cohort study was to evaluate the association between modifiable patient-related factors and complications after corrective surgery for ASD.

Methods

ASD patients with two-year data were included. Complications were categorized as follows: any complication, major, medical, surgical, major mechanical, major radiological, and reoperation. Modifiable risk factors included smoking, obesity, osteoporosis, alcohol use, depression, psychiatric diagnosis, and hypertension. Patients were stratified by the degree of baseline deformity (low degree of deformity (LowDef)/high degree of deformity (HighDef): below or above 20°) and age (Older/Younger: above or below 65 years). Complication rates were compared for modifiable risk factors in each age/deformity group, using multivariable logistic regression analysis to adjust for confounders.

Results

A total of 480 ASD patients met the inclusion criteria. By two years, complication rates were 72% ≥ one complication, 28% major, 21% medical, 27% surgical, 11% major radiological, 8% major mechanical, and 22% required reoperation. Younger LowDef patients with osteoporosis were more likely to suffer either a major mechanical (odds ratio (OR) 5.9 (95% confidence interval (CI) 1.1 to 36.9); p = 0.048) or radiological complication (OR 7.0 (95% CI 1.9 to 25.9); p = 0.003). Younger HighDef patients were much more likely to develop complications if obese, especially major mechanical complications (OR 2.8 (95% CI 1.1 to 8.6); p = 0.044). Older HighDef patients developed more complications when diagnosed with depression, including major radiological complications (OR 3.5 (95% CI 1.1 to 10.6); p = 0.033). Overall, a diagnosis of depression proved to be a risk factor for the development of major radiological complications (OR 2.4 (95% CI 1.3 to 4.5); p = 0.005).

Conclusion

Certain modifiable patient-related factors, especially osteoporosis, obesity, and mental health status, are associated with an increased risk of complications after surgery for spinal deformity. Surgeons should look for these conditions when assessing a patient for surgery, and optimize them to the fullest extent possible before proceeding to surgical correction so as to minimize the prospect of postoperative morbidity. Cite this article: Bone Joint J 2022;104-B(11):1249–1255.