Practice Patterns of Spine Surgeons Regarding Osteoporosis: An International Survey

Questionnaire Development

The survey (Tables 1 and 2) asked about the specialty and the workplace, then was divided into 3 parts:

1. Spine surgeons' practice patterns and attitudes regarding OP and spine fusion surgery (4 questions): This part assessed the role of the neurosurgeon in the diagnostic approach in patients with suspected or confirmed OP without treatment. Suspected OP was defined by the presence of risk factors such as advanced age, being postmenopausal, family history of osteoporosis, previous fracture, current smoking, and long-term treatment with corticosteroids. It also explored the modifications in the surgical plan and the most popular surgical techniques used in patients with OP.

2. Perception of the influence of OP in the development of pseudoarthrosis (2 questions): Part 2 evaluated the surgeon's opinions or perceptions of the influence of OP in the development of pseudoarthrosis and the preoperative management pseudoarthrosis in case of a revision surgery.

3. Trends and management patterns of spine surgeons with respect to osteoporotic VCF (2 questions): This part assessed diagnostic, referral and treatments patterns of spine surgeons regarding VCF.

Administration of the Survey

The survey was integrated into the online survey platform SurveyMonkey and was sent by email to the members of EANS. An invitation to participate in the survey and 2 more reminders were sent. Answers were collected through SurveyMonkey and then transferred to a database (Excel spreadsheet).

The investigation was authorized by the research ethics committee from our hospital and from the research committee of the EANS.

Statistical Analysis

Data were compiled in Excel spreadsheet files, and statistical testing analysis was performed in conjunction with SPSS software, version 25.0 (SPSS Inc, Armonk, NY). The study sample was described by calculating the frequencies and percentages for categorical variables, which were subsequently compared using χ² testing. Statistical significance was established at a 2-sided α level of .05 (P = .05).

Spine Surgeons' Practice Patterns and Attitudes Regarding OP and Spine Fusion Surgery

In our survey, in the case of suspected OP, 47.1% of the surgeons considered obtaining a DXA and/or MBP, 31.4% opted for referring to a specialist, and 21.5% would proceed with the surgery without additional studies (Table 3). Similar studies reported a trend to proceed with the surgery without additional studies in suspected OP; namely, 41% in the Dipaola et al⁸ report, 32.5% in the Spain Society of Neurosurgery (SENEC) survey,¹⁰ and 24.5% in the AOSpine Latin America survey.¹¹

There was a small proportion of surgeons (8.2%) who would prefer to proceed with the surgery without any additional studies or treatment in untreated osteoporotic patients. However, a significant proportion of participants (34.4%) preferred to refer the patient after surgery, which entailed fewer risks for the timely management of OP.⁶

Currently, there is no widely accepted consensus for a preoperative work-up for osteoporosis in the case of spinal fusion surgery.^1,8 According to the American College of Radiology, besides the risk factors for OP, BMD measurement is indicated when a clinical decision would be influenced by test results.¹ A de novo diagnosis of OP prior to spinal surgery should stimulate improvements in terms of timely treatment and lead to pertinent surgical plan modifications.

A review of surgical complications in patients over 65 years old reported an overall rate of early complications of 13%, which included pedicle fractures and VCFs, and a 26% rate of late complications such as pseudoarthrosis with instrumentation failure, adjacent-level disc degeneration, and progressive junctional kyphosis.¹²

In recent decades considerable advances have been made in the treatment of OP. Several clinical trials have investigated the impact of pharmacological treatment on bone fusion in spinal surgery with alendronate,¹³ zoledronic acid,¹⁴ and teriparatide.¹⁵ Most of them showed an increase in bone fusion rates and a reduced risk of screw loosening.

Although there is no clear consensus, some authors recommended that antiresorptive treatment should be started at least 4–6 weeks before surgery and continued in the postoperative period under specialized supervision.⁶

In addition, it has been estimated that between 40% and 90% of adults suffer from decreased serum levels of vitamin D, which could influence both clinical and radiological results of spine surgery.^16–18 It is very likely that providing the needed supplementation of vitamin D in the perioperative period will improve symptoms and may also aid in promoting bone fusion and reducing pseudoarthrosis.^1,6

Therefore, the percentages of study participants who considered MBP (only 17.35% of respondents in the present report, 12% in the case of Dipaola et al,⁸ and 10.4% in the SENEC study¹⁰) seem insufficient given the high prevalence of hypovitaminosis D and the chance of its relatively rapid correction.

Surgical Strategies and Techniques in Osteoporotic Patients

Concerning the pertinent modifications of the surgical plan in the case of patients with OP, in this report, 66.4% of surgeons would alter the surgical plan to enhance fusion. Dipaola et al⁸ found that 74% of the surgeons who reported obtaining a preoperative DXA would alter their surgical plan depending on the result; moreover, the SENEC survey^9,10 participants opted for altering the surgical plan in 48.7% of cases; and finally, in the AOSpine Latin America survey, 67.4% of respondents recognized unplanned modifications of the surgery in OP patients.¹¹

In the present survey, cement-augmented screws were a good option for 77.9% of participants, versus 70% of the surgeons in the SENEC survey.¹⁰ In the AOSpine Latin survey, 63% preferred the option of cement injection associated with instrumentation.¹¹

The surgical strategy of extending instrumentation was valid in 65% of participants of the AOSpine Latin survey.¹¹ In addition, long-segment instrumentation was identified as a good option by almost 30% of participants of the SENEC survey¹⁰ and by 45.1% of surgeons in the present report.

Longer fusion constructs for surgical stabilization can provide increased points of fixation that help protect against junctional or segmental failure.⁶ Authors recommended surgeons avoid starting or ending the constructs at the cervicothoracic or thoracolumbar junction and to extend the instrumentation at least 3 fixation points above and below the apex of a deformity.^12,19,20

Hybrid posterior constructs that use pedicle screws, sublaminar wires, and laminar hooks may increase pull-out strength in osteoporotic bone and improve fixation secondary to the relative preservation of cortical bone in the lamina.⁶

Several observational studies in patients with OP have shown that cement augmentation of pedicle screws and expandable pedicle screws can improve fusion rates and decrease complications related to OP.⁵

Polymethyl methacrylate augmentation of pedicle screws has been proven to increase pull-out strength by 119%–250%, but high polymerization temperature and leakage are among some of the risks associated with its use.^19,21,22

Alternatively, expansive pedicle screws have comparable pull-out strength to standard screws augmented with polymethyl methacrylate and 42.7% greater force than screws augmented with a calcium-based cement.^19,21

Pseudoarthrosis and Osteoporosis

Regarding spine surgeons' attitudes toward pseudarthrosis, Dipaola et al⁸ found that only 19% of surgeons requested a DXA and 20% asked for a bone metabolic profile in patients with pseudoarthrosis. In the SENEC report,¹⁰ 46.1% of respondents did not consider conducting any additional studies for the diagnosis of OP even in the case of reintervention, and only 27.6% would refer the patient to an OP specialist. In our survey, 23.8% of participants would proceed with a reintervention without any additional studies or treatment, and almost 30% opted to refer to a specialist in OP.

The decrease in BMD is an independent risk factor related to the failure of instrumentation in lumbar fusion surgery.²⁰ If revision surgery becomes necessary for an established symptomatic pseudarthrosis, it is recommended to rule out disorders that may deteriorate bone quality, such as OP, smoking, malnutrition, hyperparathyroidism, rheumatoid arthritis, and other systemic inflammatory diseases.^23,24 Consequently, it is reasonable (depending on the clinical context) to make the effort to diagnose and treat a potential risk factor such as OP before revision surgery in a patient with a pseudarthrosis.

Trends and Management Patterns of Spine Surgeons Concerning Osteoporotic VCF

Regarding the participation of spine surgeons in the case of VCF, Dipaola et al⁸ found that 60% of spine surgeons would request a DXA and 39% would ask for metabolic bone laboratory test results after a VCF. In the SENEC study,¹⁰ respondents would improve OP management either by referring the patient to a specialist for medical management (59.7%) or by performing a diagnostic test to confirm OP (24%). In the present survey, 88.4% of surgeons considered referring the patient for treatment or obtaining DXA and metabolic laboratory test results.

It has been seen that any intervention to evaluate osteoporosis in patients sustaining fragility fractures significantly increased the likelihood of treatment of OP.⁷ On the basis of previous reports and this study, it appears that spine surgeons have registered a greater awareness and active participation in the case of VCF related to OP. In our survey, more spine surgeons would agree to screen for OP or refer patients in the case of VCF than with a suspected OP in spine surgery or pseudoarthrosis.

Although VCF, spondylarthrosis, and pseudoarthrosis can be considered different entities with different surgical treatments, it is also true that osteoporotic VCFs are merely a symptom of an underlying metabolic bone disease, and referral for OP treatment should be standard practice, as it is for candidates for spine surgery with risk factors for OP. Second, although not identical to fracture healing, fusion mass healing goes through stages of endochondral ossification and membranous bone healing⁷; the ultimate goal in the treatment of fractures and for fusion is to get them to heal as quickly as possible. Last, spine surgeons, who are frequently provide initial care, are in a unique position to recognize pathologic fractures or detect potential OP in patients scheduled for fusion surgery and institute proper therapy or referrals.^7,8

Regarding the treatment patterns for patients with VCF, 66.2% of participants in the SENEC study¹⁰ and 55.7% in the present report considered that the most appropriate treatment was vertebral augmentation after a 4–6 weeks of conservative treatment with no improvement. Nevertheless, 22.4% of respondents in the SENEC survey¹⁰ and 30.3% in the present EANS survey opted for a vertebral augmentation technique (vertebroplasty or kyphoplasty) at the time of diagnosis.

The updated Cochrane review included the analysis of 5 randomized trials that compared vertebroplasty with a placebo and concluded that there was high-quality evidence that percutaneous vertebroplasty conferred no clinically important benefits concerning pain, disability, or disease-specific quality of life.²⁵

In addition, The American Society for Bone and Mineral Research (ASBMR) created a task force to address key questions on the efficacy and safety of vertebral for patients with acutely painful osteoporotic vertebral fractures. It was founded that percutaneous vertebroplasty provides no demonstrable clinically important benefits compared with placebo or sham procedures.²⁶

However, the ASBMR task force recommendations have aroused many criticisms. One is that they completely discount the large body of literature on vertebral augmentation, and some authors argue that vertebral augmentation is demonstrably a lifesaving and life-prolonging procedure as it can statistically save a life for every 15 patients treated.^27,28 In addition, the task force report does not accurately reflect the evidence for vertebroplasty in patients with severe symptoms within 6 weeks of fracture onset. The VAPOUR trial is the only blinded trial to specifically assess this patient group and found vertebroplasty to be more effective than placebo in alleviating severe pain within 6 weeks.²⁹ Consequently, there is still controversy and no consensus regarding vertebral augmentation.

Regarding the limitations of our research, one was the limited number of key questions; consequently, some important information could not be evaluated. This was balanced by the fact that the rate of response was affected by the length of the survey. This survey was conducted with surgeon members of the EANS whose practices were representative of the neurosurgical community only, and this may have produced a selection bias.

On the basis of recent reports in the literature (Table 3), there is still significant need to improve spine surgeons' awareness and OP management, because between 21% and 41% of surgeons would proceed with spine surgery without additional studies in the case of suspected OP, and 60%–80% of spine surgeons polled appeared to not consider an osteoporosis work-up to be a routine part of a pseudoarthrosis work-up. Only 10%–17% of surgeons considered getting an MBP.^16,17

Finally, the study of these practice patterns of spine surgeons gives valuable insight into the actual decision-making process in clinical practice and treatment strategy and may help in the creation of consensus guidelines. Bone mineral status measurement, MBP evaluation, and prompt referral if needed should be considered in patients older than 50 years, as a routine work-up for spine surgery, pseudoarthrosis patients, and after a VCF.