The efficacy of combined vitamin K2 and D3 therapy on bone fusion outcomes following endoscopic lumbar surgery in osteoporotic patients remains unclear. This prospective study investigated the effects of combined vitamin K2 and D3 supplementation on fusion outcomes in osteoporotic patients undergoing endoscopic lumbar interbody fusion. Seventy-one patients were divided into two groups: the experimental group (n = 36) received vitamin K2 (45 mg/day), vitamin D3 (250 IU/day), and calcium (1.2 g/day), while the control group (n = 35) received only vitamin D3 (250 IU/day) and calcium (1.2 g/day) for 6 months postoperatively. The primary outcome was fusion rate assessed by CT and dynamic radiography. At 6 months postoperatively, the VK2 + VD3 group showed significantly higher complete fusion rates compared to the control group (91.67% vs. 74.29%, P = 0.044). Serum P1NP levels were significantly higher in the VK2 + VD3 group at 3 months postoperatively (P = 0.001). Both groups showed comparable improvements in clinical outcomes (JOA-BPEQ and ODI scores). While BMD changes were not statistically significant between groups, the VK2 + VD3 group showed a trend toward BMD improvement. These findings suggest that combined vitamin K2 and D3 supplementation may enhance early fusion outcomes in osteoporotic patients undergoing endoscopic lumbar interbody fusion, potentially offering a simple and effective adjunct therapy for improving surgical outcomes.

To achieve good bone fusion in anterior column reconstruction for vertebral fractures, not only bone mineral density (BMD) and bone metabolism markers but also lever arms due to bone bridging between vertebral bodies should be evaluated. However, until now, no lever arm index has been devised. Therefore, we believe that the maximum number of vertebral bodies that are bony and cross-linked with the contiguous adjacent vertebrae (maxVB) can be used as a measure for lever arms. The purpose of this study is to investigate the surgical outcomes of anterior column reconstruction for spinal fractures and to determine the effect of bone bridging between vertebral bodies on the rate of bone fusion using the maxVB as an indicator of the length of the lever arm.

The clinical data of 81 patients who underwent anterior column reconstruction for spinal fracture between 2014 and 2022 were evaluated. The bone fusion rate, back pain score, between the maxVB = 0 and the maxVB ≥ 2 patients were adjusted for confounding factors (age, smoking history, diabetes mellitus history, BMD, osteoporosis drugs, surgical technique, number of fixed vertebrae, materials used for the anterior props, etc.) and analysed with multivariate or multiple regression analyses. The bone healing rate and incidence of postoperative back pain were compared among the three groups (maxVB = 0, 2≦maxVB≦8, maxVB ≧ 9) and divided by the maxVB after adjusting for confounding factors.

Patients with a maxVB ≥ 2 had a significantly higher bone fusion rate (p < 0.01) and postoperative back pain score (p < 0.01) than those with a maxVB = 0. Among the three groups, the bone fusion rate and back pain score were significantly higher in the 2≦maxVB≦8 group (p = 0.01, p < 0.01).

Examination of the maxVB as an indicator of the use of a lever arm is beneficial for anterior column reconstruction for vertebral fractures. Patients with no intervertebral bone bridging or a high number of bone bridges are in more need of measures to promote bone fusion than patients with a moderate number of bone bridges are.

Systematic review and meta-analysis.

In an effort to prevent intraoperative neurological injury during spine surgery, the use of intraoperative neurophysiological monitoring (IONM) has increased significantly in recent years. Using IONM, spinal cord function can be evaluated intraoperatively by recording signals from specific nerve roots, motor tracts, and sensory tracts. We performed a systematic review and meta-analysis of diagnostic test accuracy (DTA) studies to evaluate the efficacy of IONM among patients undergoing spine surgery for any indication.

The current systematic review and meta-analysis was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis statement for Diagnostic Test Accuracy Studies (PRISMA-DTA) and was registered on PROSPERO. A comprehensive search was performed using MEDLINE, EMBASE and SCOPUS for all studies assessing the diagnostic accuracy of neuromonitoring, including somatosensory evoked potential (SSEP), motor evoked potential (MEP) and electromyography (EMG), either on their own or in combination (multimodal). Studies were included if they reported raw numbers for True Positives (TP), False Negatives (FN), False Positives (FP) and True Negative (TN) either in a 2 × 2 contingency table or in text, and if they used postoperative neurologic exam as a reference standard. Pooled sensitivity and specificity were calculated to evaluate the overall efficacy of each modality type using a bivariate model adapted by Reitsma et al, for all spine surgeries and for individual disease groups and regions of spine. The risk of bias (ROB) of included studies was assessed using the quality assessment tool for diagnostic accuracy studies (QUADAS-2).

A total of 163 studies were included; 52 of these studies with 16,310 patients reported data for SSEP, 68 studies with 71,144 patients reported data for MEP, 16 studies with 7888 patients reported data for EMG and 69 studies with 17,968 patients reported data for multimodal monitoring. The overall sensitivity, specificity, DOR and AUC for SSEP were 71.4% (95% CI 54.8-83.7), 97.1% (95% CI 95.3-98.3), 41.9 (95% CI 24.1-73.1) and .899, respectively; for MEP, these were 90.2% (95% CI 86.2-93.1), 96% (95% CI 94.3-97.2), 103.25 (95% CI 69.98-152.34) and .927; for EMG, these were 48.3% (95% CI 31.4-65.6), 92.9% (95% CI 84.4-96.9), 11.2 (95% CI 4.84-25.97) and .773; for multimodal, these were found to be 83.5% (95% CI 81-85.7), 93.8% (95% CI 90.6-95.9), 60 (95% CI 35.6-101.3) and .895, respectively. Using the QUADAS-2 ROB analysis, of the 52 studies reporting on SSEP, 13 (25%) were high-risk, 10 (19.2%) had some concerns and 29 (55.8%) were low-risk; for MEP, 8 (11.7%) were high-risk, 21 had some concerns and 39 (57.3%) were low-risk; for EMG, 4 (25%) were high-risk, 3 (18.75%) had some concerns and 9 (56.25%) were low-risk; for multimodal, 14 (20.3%) were high-risk, 13 (18.8%) had some concerns and 42 (60.7%) were low-risk.

These results indicate that all neuromonitoring modalities have diagnostic utility in successfully detecting impending or incident intraoperative neurologic injuries among patients undergoing spine surgery for any condition, although it is clear that the accuracy of each modality differs.PROSPERO Registration Number: CRD42023384158.

The incidence of osteoporosis is a prime concern, especially in parts of the world where the population is aging, such as Europe or the US. Many new therapy strategies have been described to enhance bone healing. Lumbar interbody fusion (LIF) is a surgical procedure that aims to stabilize the lumbar spine by fusing two or more vertebrae using an interbody cage. LIF is a standard treatment for various spinal conditions, such as degenerative disc disease, spinal stenosis, and spondylolisthesis. However, successful fusion is challenging for patients with osteoporosis due to their reduced bone mineral density (BMD) and increased risk of cage subsidence, which can lead to implant failure and poor clinical outcomes.

 A comprehensive literature search yielded 220 articles, with 16 ultimately included. Keywords included BMD, cage subsidence, osteoporosis, teriparatide, and lumbar interbody fusion.

 This review examines the relationship between BMD and LIF success, emphasizing the importance of adequate bone quality for successful fusion. Preoperative assessment methods for BMD and the impact of low BMD on fusion rates and patient outcomes are discussed. Additionally, techniques to improve fusion success in patients with weakened bone density, such as biological enhancement and BMD-matched interbody cages, are explored. However, consensus on the exact BMD threshold for a successful outcome remains elusive.

 While an apparent correlation between BMD and fusion rate in LIF procedures is acknowledged, conclusive evidence regarding the precise BMD threshold indicative of an increased risk of unfavorable outcomes remains elusive. Surgeons are advised to exercise caution in surgical planning and follow-up for patients with lower BMD. Furthermore, future research initiatives, particularly longitudinal studies, are encouraged to prioritize the examination of BMD as a fundamental risk factor, addressing gaps in the literature.

Administering anti-osteoporotic agents to patients perioperatively is a widely accepted approach for improving bone fusion rates and reducing the risk of complications. The best anti-osteoporotic agents for spinal fusion surgery remain unclear.

To investigate the efficacy and safety of different anti-osteoporotic agents in spinal fusion surgery via network meta-analysis.

Searches were conducted in four electronic databases (PubMed, EMBASE, Web of Science, the Cochrane Library and China National Knowledge Infrastructure (CNKI) from inception to November 2022. Any studies that compared anti-osteoporotic agents vs placebo for spinal fusion surgery were included in this network meta-analysis. Outcomes included fusion rate, Oswestry disability index (ODI), and adverse events. Network meta-analysis was performed by R software with the gemtc package.

In total, 13 randomized controlled trials were included in this network meta-analysis. Only teriparatide (OR 3.2, 95%CI: 1.4 to 7.8) was more effective than placebo in increasing the fusion rate. The surface under the cumulative ranking curve (SUCRA) of teriparatide combined with denosumab was the highest (SUCRA, 90.9%), followed by teriparatide (SUCRA, 74.0%), zoledronic acid (SUCRA, 43.7%), alendronate (SUCRA, 41.1%) and risedronate (SUCRA, 35.0%). Teriparatide (MD -15, 95%CI: -28 to -2.7) and teriparatide combined with denosumab (MD -20, 95%CI: -40 to -0.43) were more effective than placebo in decreasing the ODI. The SUCRA of teriparatide combined with denosumab was highest (SUCRA, 90.8%), followed by teriparatide (SUCRA, 74.5%), alendronate (SURCA, 52.7), risedronate (SURCA, 52.1%), zoledronic acid (SURCA, 24.2%) and placebo (SURCA, 5.6%) for ODI. The adverse events were not different between groups.

This network meta-analysis suggests that teriparatide combined with denosumab and teriparatide alone significantly increase the fusion rate and decrease the ODI without increasing adverse events. Based on current evidence, teriparatide combined with denosumab or teriparatide alone is recommended to increase the fusion rate and to reduce ODI in spinal fusion patients.

This study adopted a retrospective cohort study design.

This study aimed to clarify the influence of diffuse idiopathic skeletal hyperostosis (DISH) on bone fusion after transforaminal lumbar interbody fusion (TLIF).

The negative effects of DISH on lumbar degenerative diseases have been reported, and DISH may be involved in the onset and severity of lumbar spinal canal stenosis. Patients with DISH have significantly more reoperations after posterior lumbar fusion, including TLIF. However, the effects of DISH on bone fusion after TLIF have not been reported.

The medical records of patients with intervertebral TLIF from 2012 to 2018 were retrospectively examined. The patients were divided into those with fusion and those with pseudoarthrosis, and the following data were compared: age, sex, DISH, diabetes mellitus, smoking, drinking, albumin levels, body mass index ≥30 kg/m2, and L5/S fixation. Statistical analyses were performed using regression models.

In this study, 180 patients (78.6%) had fusion and 49 patients (21.4%) had pseudoarthrosis. The number of patients with DISH was significantly higher in the pseudoarthrosis group than in the fusion group (36.7% and 21.7%, respectively; univariate p=0.031, multivariate p =0.019). No significant differences in age, sex, diabetes mellitus, smoking, drinking, albumin levels, body mass index ≥30 kg/m2, and L5/S fixation were observed between the two groups. The risk factors for bone fusion were statistically analyzed in 57 patients with DISH. DISH with a caudal end below Th11 was an independent risk factor for pseudoarthrosis (univariate p=0.011, multivariate p=0.033).

DISH is an independent risk factor for pseudoarthrosis after one intervertebral TLIF, and DISH with a caudal end below Th11 is associated with a higher risk of pseudoarthrosis than DISH without a caudal end below Th11.

As an indicator to evaluate the risk of fracture in diffuse idiopathic skeletal hyperostosis, the maximum number of vertebral bodies' bone cross-linked with contiguous adjacent vertebrae (max VB) was developed. This study retrospectively investigates the relationship between max VB, bone mineral density (BMD), and bone metabolic markers (BMM).

In this cross-sectional study (from April 2010 to January 2022), males (n = 114) with various max VB from the thoracic vertebra to the sacrum, measured using computed tomography scans, were selected to assess femur BMD and BMM. The association of max VB with the total type I procollagen N-terminal propeptide (P1NP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and bone turnover ratio (BTR = TRACP-5b/P1NP) as well as its relationship with femur BMD with P1NP and TRACP-5b, were investigated. Furthermore, the relationship between P1NP and TRACP-5b was investigated.

P1NP increased in proportion to max VB and TRACP-5b increased in proportion to P1NP. Moreover, BTR was inversely proportional to max VB. Finally, femur BMD was inversely proportional to P1NP and TRACP-5b.

As max VB increased with P1NP-a potential osteogenesis indicator-and BTR was inversely proportional to max VB with compensatory TRACP-5b increase, max VB can be considered as a possible predictor of bone fusion.

Background Delayed union or pseudoarthrosis after posterior lumbar interbody fusion (PLIF) is associated with poor outcomes in health-related quality of life. Therefore, it is important to achieve earlier solid fusion for a successful clinical outcome after PLIF. A few authors reported that biomechanical factors may influence spinal fusion rates. The purpose of our retrospective study was to evaluate the independent predictors of delayed osseous union related to intraoperative procedures of PLIF, and to find ways to reduce delayed osseous union. Methods This was a retrospective study of a completed trial. We reviewed 66 elderly patients with osteoporosis after PLIF (all female, mean age 71 years, follow-up period over 6 months). Lumbar computed tomography scans at 2 months postoperatively were examined for the presence of a translucent zone between autograft and endplate (more than 50% of vertebral diameter), and autograft position with bone bridging (anterior, central, or posterior). Osseous union was assessed by using computed tomography 6 months postoperatively. Results Thirty-three patients (50%) showed complete osseous union, while 33 did not. A translucent zone between autograft and endplate two months postoperatively was observed in nine patients (27%) in the union group and in 23 (70%) in the nonunion group (p<0.01). Autograft position with bone bridging two months postoperatively was anterior, central, and posterior in 17 (52%), 30 (91%), and 20 patients (61%) in the union group, and in 12 (36%), 20 (61%), and seven patients (21%) in the nonunion group (p=0.22, p<0.01, and p<0.01), respectively. Multivariate logistic regression analysis showed that the presence of a translucent zone between autograft and endplate (odds ratio, 0.101; 95% confidence interval: 0.026-0.398; p<0.01) and teriparatide administration (odds ratio, 8.810; 95% confidence interval: 2.222-34.936; p<0.01) were independently associated with osseous union after PLIF. Conclusions A translucent zone between autograft and endplate at two months postoperatively independently predicted delayed osseous union within six months after PLIF. Complete osseous union rates were higher in patients with posterior bone bridging two months postoperatively than in those without. These findings apart from preoperative predictors of osseous union might serve as indicators of how intraoperative techniques affects osseous union enhancement.

A cost-utility analysis study.

This study aims to evaluate the cost-utility of neoadjuvant teriparatide therapy in osteopenic patients undergoing adult spinal deformity (ASD) surgery.

There is increasing evidence supporting preoperative use of anabolic agents such as teriparatide for preoperative optimization of ASD patients with poor bone density. However, such treatments are associated with added costs. To our knowledge, the cost-utility of teriparatide in osteopenic patients undergoing ASD surgery has not been established.

A decision-analysis model was developed for a hypothetical 68-year-old female patient with osteopenia ( T score <-1.0) undergoing a T11 to pelvis instrumented spinal fusion for ASD. A comprehensive literature review was conducted to create estimates for event probabilities, costs, and quality adjusted life years at each node. Key model assumptions were that administration of a 4-month preoperative teriparatide course reduced 2-year postoperative reoperation rates [for pseudarthrosis from 5% to 2.5% and for proximal junctional failure (PJF) from 15% to 5%]. Monte Carlo simulations were used to calculate the mean incremental cost utility ratio and incremental net monetary benefits. One-way sensitivity analysis was used to estimate the contribution of individual parameters to uncertainty in the model.

Teriparatide was the favored strategy in 82% of the iterations. The mean incremental cost utility ratio for the teriparatide strategy was negative (higher net benefit, lower net cost), and lower than the willingness-to-pay threshold of $50,000 per quality adjusted life year. Teriparatide use was associated with a mean incremental net monetary benefit of $3,948. One-way sensitivity analysis demonstrated that the factors with the greatest impact on the model were the incidence of PJF in the no teriparatide group, the duration and monthly cost of treatment, and the cost of reoperation due to PJF.

Neoadjuvant teriparatide is a cost-effective strategy to reduce postoperative complications in patients with osteopenia undergoing ASD surgery.

Retrospective cohort study.

Nonunion after posterior lumbar interbody fusion (PLIF) is associated with poor improvements in health-related quality of life (HRQOL). We aimed to investigate the influence of early osseous union after PLIF on HRQOL.

We reviewed 138 patients with 1-level PLIF (mean age 67 years, follow-up period ≥1 year). Postoperative lumbar computed tomography was performed to assess screw loosening and intervertebral union. HRQOL was assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire.

Thirty-nine patients (28%) showed complete union at 6 months postoperatively (early union group). Twenty-eight patients (20%) showed complete union at 6 to 12 months postoperatively (delayed union group), while 71 patients demonstrated noncomplete union. Effective improvement of lumbar spine dysfunction and psychological disorders was achieved in 19 (63.3%) and 17 (50.0%) patients in the early union group, in 9 (42.9%) and 14 (53.8%) patients in the delayed union group, and in 22 (34.9%) and 19 (29.2%) patients in the nonunion group, respectively (P = .036 and P = .036, respectively). The nonunion group had a significantly higher proportion of cases with screw loosening at 6 and 12 months postoperatively than the complete union group (P = .033 and P = .022).

Lumbar spine dysfunction and psychological disorders improved in cases with early complete union compared to those with nonunion. Screw loosening occurred in cases with nonunion predominantly from 6 months postoperatively. Therefore, the achievement of early complete union might be helpful for better HRQOL and lower incidence of postoperative complications.

A prospective and nonrandomized concurrent controlled trial.

To address the early effects of concurrent treatment with vitamin K2 and vitamin D3 on fusion rates in patients who have undergone spinal surgery.

Intervertebral pseudarthrosis has been reported after transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion (PLIF), especially in patients with osteopenia or osteoporosis. No study has assessed the early effects of concurrent treatment with vitamin K2 and vitamin D3 on fusion rates.

Patients with osteopenia or osteoporosis who underwent TLIF or PLIF in our department were included. Patients in the VK2+VD3 group received vitamin K2, vitamin D3, and calcium treatment, whereas subjects in the control group only received calcium and vitamin D3. Spine fusion was evaluated by computed tomography. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOA-BPEQ) and visual analog scale (VAS) were used to assess the clinical and neurological symptoms. Bone mineral density (BMD) and bone metabolism markers were measured for osteoporotic evaluation.

Seventy-eight patients were included, and nine patients subsequently discontinued because of 2019-nCoV. At six months postoperatively, complete fusion rates were significantly higher in the VK2+VD3 group than that in the control group (91.18% vs 71.43%, P = 0.036). At six months postoperatively, BMD was increased in the VK2+VD3 group and was higher than that in the control group, although there was no significant difference. At three months postoperatively, a significant increase in procollagen type I amino terminal propeptide (91.81%) and a slight decrease in C-terminal end peptide (8.06%) were observed in the VK2+VD3 group. In both groups, the JOA-BPEQ and VAS scores were significantly improved after spine surgery.

Administration of vitamin K2 and vitamin D3 can increase lumbar interbody fusion rates, improve clinical symptoms, promote bone information, and avoid further decline in BMD within six months after TLIF or PLIF.Level of Evidence: 3.

Expert consensus study.

This expert panel was created to establish best practice guidelines to identify and treat patients with poor bone health prior to elective spinal reconstruction.

Currently, no guidelines exist for the management of osteoporosis and osteopenia in patients undergoing spinal reconstructive surgery. Untreated osteoporosis in spine reconstruction surgery is associated with higher complications and worse outcomes.

A multidisciplinary panel with 18 experts was assembled including orthopedic and neurological surgeons, endocrinologists, and rheumatologists. Surveys and discussions regarding the current literature were held according to Delphi method until a final set of guidelines was created with over 70% consensus.

Panelists agreed that bone health should be considered in every patient prior to elective spinal reconstruction. All patients above 65 and those under 65 with particular risk factors (chronic glucocorticoid use, high fracture risk or previous fracture, limited mobility, and eight other key factors) should have a formal bone health evaluation prior to undergoing surgery. DXA scans of the hip are preferable due to their wide availability. Opportunistic CT Hounsfield Units of the vertebrae can be useful in identifying poor bone health. In the absence of contraindications, anabolic agents are considered first line therapy due to their bone building properties as compared with antiresorptive medications. Medications should be administered preoperatively for at least 2 months and postoperatively for minimum 8 months.

Based on the consensus of a multidisciplinary panel of experts, we propose best practice guidelines for assessment and treatment of poor bone health prior to elective spinal reconstructive surgery. Patients above age 65 and those with particular risk factors under 65 should undergo formal bone health evaluation. We also established guidelines on perioperative optimization, utility of various diagnostic modalities, and the optimal medical management of bone health in this population.Level of Evidence: 5.

Bisphosphonates and teriparatide are the most common therapies used in the treatment of osteoporosis. Their impact on fusion rates in osteoporotic patients following spinal fusion has yet to be concretely defined, with previous systematic reviews focusing heavily on bisphosphonates and lacking clinical insight on the utility of teriparatide. Herein the authors present an updated meta-analysis of the utility of both bisphosphonates and teriparatide in improving spinal fusion outcomes in osteoporotic patients.

After a comprehensive search of the English-language literature in the PubMed and Embase databases, 11 clinical studies were included in the final qualitative and quantitative analyses. Of these studies, 9 investigated bisphosphonates, 7 investigated teriparatide, and 1 investigated a combination of teriparatide and denosumab. Odds ratios and 95% confidence intervals were calculated where appropriate.

A meta-analysis of the postoperative use of bisphosphonate demonstrated better odds of successful fusion as compared to that in controls during short-term monitoring (OR 3.33, 95% CI 1.72-6.42, p = 0.0003) but not long-term monitoring (p > 0.05). Bisphosphonate use was also shown to significantly reduce the likelihood of postoperative vertebral compression fracture (VCF; OR 0.07, 95% CI 0.01-0.59, p = 0.01) and significantly reduce Oswestry Disability Index scores (mean difference [MD] = -2.19, 95% CI -2.94 to -1.44, p < 0.00001) and visual analog scale pain scores (MD = -0.58, 95% CI -0.79 to -0.38, p < 0.00001). Teriparatide was found to significantly increase fusion rates at long-term postoperative periods as compared to rates after bisphosphonate therapy, with patients who received postoperative teriparatide therapy 2.05 times more likely to experience successful fusion (OR 2.05, 95% CI 1.17-3.59, p = 0.01).

The authors demonstrate the benefits of bisphosphonate and teriparatide therapy independently in accelerating fusion during the first 6 months after spinal fusion surgery in osteoporotic patients. In addition, they show that teriparatide may have superior benefits in spinal fusion during long-term monitoring as compared to those with bisphosphonates. Bisphosphonates may be better suited in preventing VCFs postoperatively in addition to minimizing postoperative disability and pain.

Nonunion after posterior lumbar interbody fusion (PLIF) is associated with poor long-term outcomes in terms of health-related quality of life. Biomechanical factors in the fusion segment may influence spinal fusion rates. There are no reports on the relationship between intervertebral union and the absorption of autografts or vertebral endplates. Therefore, the purpose of this retrospective study was to evaluate the risk factors of nonunion after PLIF and identify preventive measures.

The authors analyzed 138 patients who underwent 1-level PLIF between 2016 and 2018 (75 males, 63 females; mean age 67 years; minimum follow-up period 12 months). Lumbar CT images obtained soon after the surgery and at 6 and 12 months of follow-up were examined for the mean total occupancy rate of the autograft, presence of a translucent zone between the autograft and endplate (more than 50% of vertebral diameter), cage subsidence, and screw loosening. Complete intervertebral union was defined as the presence of both upper and lower complete fusion in the center cage regions on coronal and sagittal CT slices at 12 months postoperatively. Patients were classified into either union or nonunion groups.

Complete union after PLIF was observed in 62 patients (45%), while nonunion was observed in 76 patients (55%). The mean total occupancy rate of the autograft immediately after the surgery was higher in the union group than in the nonunion group (59% vs 53%; p = 0.046). At 12 months postoperatively, the total occupancy rate of the autograft had decreased by 5.4% in the union group and by 11.9% in the nonunion group (p = 0.020). A translucent zone between the autograft and endplate immediately after the surgery was observed in 14 and 38 patients (23% and 50%) in the union and nonunion groups, respectively (p = 0.001). The nonunion group had a significantly higher proportion of cases with cage subsidence and screw loosening at 12 months postoperatively in comparison to the union group (p = 0.010 and p = 0.009, respectively).

A lower occupancy rate of the autograft and the presence of a translucent zone between the autograft and endplate immediately after the surgery were associated with nonunion at 12 months after PLIF. It may be important to achieve sufficient contact between the autograft and endplate intraoperatively for osseous union enhancement and to avoid excessive absorption of the autograft. The achievement of complete intervertebral union may decrease the incidence of cage subsidence or screw loosening.

Osteoporosis is one of the most common conditions among adults worldwide. It also presents a challenge among patients undergoing spinal surgery. Use of Teriparatide and bisphosphonates in such patients has been shown to improve outcomes after fusion surgery, including successful fusion, decreased risk of instrumentation failure, and patient-reported outcomes. Herein, we performed a systematic review and indirect meta-analysis of available literature on outcomes of fusion surgery after use of bisphosphonates or Teriparatide.

We conducted a comprehensive search of all databases (Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus) to identify studies assessing outcomes of spinal fusion among osteoporotic patients after use of Teriparatide or bisphosphonate. Four authors independently screened electronic search results, and all four authors independently performed study selection. Two authors performed independent data extraction and assessed the studies' risk of bias assessment using standardized forms of Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) and Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I).

Nineteen studies were included in the final analysis. A total of 13 studies evaluated the difference in fusion rate between bisphosphonates and Teriparatide or control group. Fusion rate was higher for bisphosphonates (effect size (ES) 83%, 95% CI 77-89%) compared with Teriparatide (ES 71%, 95% CI 57-85%), with the p value for heterogeneity between groups without statistical significance (p = 0.123). Five studies assessed the impact of using bisphosphonate or Teriparatide on screw loosening. The rate of screw loosening was higher for bisphosphonates (ES 19%, 95% CI 13-25%) compared with Teriparatide (ES 13%, 95% CI 9-16%) without statistical significance (p = 0.52).

Our results indicate that while both agents may be associated with positive outcomes, bisphosphonates may be associated with a higher fusion rate, while Teriparatide may be associated with lower screw loosening. The decision to treat with either agent should be tailored individually for each patient keeping in consideration the adverse effect and pharmacokinetic profiles.

Here, we determined whether teriparatide treatment would increase fusion rates after foot and ankle arthrodesis by comparing treatment results between patients with high-risk factors for nonunion who received teriparatide against those who did not.

We retrospectively reviewed 66 consecutive patients who underwent foot and ankle arthrodesis. The inclusion criterion was the presence of at least one of the following risk factors for nonunion after previous foot and ankle arthrodesis: deformity, bone defects, avascular necrosis, and nonunion. Sixteen patients were finally enrolled and divided into 2 groups: 8 patients received teriparatide treatment after fusion surgery (PTH group), and 8 patients did not (control group).

The fusion rate was significantly greater in the PTH group than in the control group (100% vs 50%). Four patients in the control group developed nonunion, 3 of whom underwent revision fusion; however, all patients received the teriparatide treatment after revision surgery and subsequently achieved union. No significant differences in demographics, fusion sites, and complication rates were found.

Though the sample size was small, the current study suggests that teriparatide administration may improve fusion rates in patients with high-risk factors for nonunion after foot and ankle arthrodesis.

A multicenter, randomized, open-label, parallel-group trial.

To investigate interbody bone fusion rates in titanium-coated polyetheretherketone (TiPEEK) and polyetheretherketone (PEEK) cages after posterior lumbar interbody fusion (PLIF) surgery.

Previous clinical studies have not revealed any significant difference in bone fusion rates between TiPEEK and PEEK cages.

During one-level PLIF surgery, 149 patients (84 men, 65 women, mean age 67 yr) were randomly allocated to use either a TiPEEK cage (n = 69) or PEEK cage (n = 80). Blinded radiographic evaluations were performed using computed tomography and assessed by modified intention-to-treat analysis in 149 cases and per-protocol analysis in 143 cases who were followed for 12 months. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and the Oswestry Disability Index.

The interbody union rate at 12 months after surgery was 45% owing to a very strict definition of bone fusion. The rates of bone fusion were significantly higher at 4 and 6 months after surgery in the TiPEEK group than in the PEEK group in the unadjusted modified intention-to-treat analysis and were significantly higher at 6 months in the unadjusted per-protocol analysis. Binary logistic regression analysis adjusted for sex, age, body mass index, bone mineral density, and surgical level showed that using a TiPEEK cage (odds ratio, 2.27; 95% confidence interval: 1.09-4.74; P = 0.03) was independently associated with bone fusion at 6 months after surgery. Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Oswestry Disability Index results improved postoperatively in both groups.

Using the TiPEEK cage for PLIF enabled the maintenance of better bone fusion to the endplate than using the PEEK cage at 6 months after the surgery. Our findings suggest the possibility of an earlier return to rigorous work or sports by the use of TiPEEK cage.

1.

As the ageing population continues to grow, the incidence of osteoporosis continues to rise. Patients with osteoporosis are often managed pharmacologically. It is unclear the impact of these medications on osteoporotic patients requiring lumbar interbody fusion, and whether differences exist with respect to patient outcomes among the different medication classes that are often employed. In this systematic review, the authors examine studies evaluating the impact of pharmacologic therapy on osteoporotic patients undergoing lumbar interbody fusion.

Using PubMed and MEDLINE databases, the authors conducted a systematic literature review for studies published between 1986 and 2020 following PRISMA guidelines.

A total of 12 articles were ultimately selected. Studies assessing bisphosphonate usage, parathyroid hormone analogues, vitamin D, or combination therapies and their impact on lumbar interbody fusion were included.

The evidence regarding bisphosphonate therapy and improved fusion rates with reduced incidence of complications is inconsistent. While some studies suggest bisphosphonates to confer added benefit, other studies suggest no such improvements despite reduction in bone turnover biomarkers. Teriparatide, on the other hand, consistently demonstrated improved fusion rates and may reduce screw loosening events. In comparison studies against bisphosphonates, teriparatide demonstrates greater potential. A single study reported vitamin D3 to increase fusion rates, although more studies are needed to validate this finding. It is important to note that these benefits are only demonstrated in single-level fusion, with multi-level fusions not being significantly enhanced by teriparatide therapy. Combination therapy with denosumab further augment fusion rates. Further prospective randomized controlled trials are necessary before standardized recommendations regarding pharmacological intervention in patients undergoing LIF can be made.