Short-term adverse events, length of stay, and readmission after iliac crest bone graft for spinal fusion

High Strength and Shape Memory Spinal Fusion Device for Minimally Invasive Interbody Fusions

Introduction

Lumbar interbody fusion is widely employed for both acute and chronic spinal diseases interventions. However, large incision created during interbody cage implantation may adversely impair spinal tissue and influence postoperative recovery. The aim of this study was to design a shape memory interbody fusion device suitable for small incision implantation.

Methods

In this study, we designed and fabricated an intervertebral fusion cage that utilizes near-infrared (NIR) light-responsive shape memory characteristics. This cage was composed of bisphenol A diglycidyl ether, polyether amine D-230, decylamine and iron oxide nanoparticles. A self-hardening calcium phosphate-starch cement (CSC) was injected internally through the injection channel of the cage for healing outcome improvement.

Results

The size of the interbody cage is reduced from 22 mm to 8.8 mm to minimize the incision size. Subsequent NIR light irradiation prompted a swift recovery of the cage shape within 5 min at the lesion site. The biocompatibility of the shape memory composite was validated through in vitro MC3T3-E1 cell (osteoblast-like cells) adhesion and proliferation assays and subcutaneous implantation experiments in rats. CSC was injected into the cage, and the relevant results revealed that CSC is uniformly dispersed within the internal space, along with the cage compressive strength increasing from 12 to 20 MPa.

Conclusion

The results from this study thus demonstrated that this integrated approach of using a minimally invasive NIR shape memory spinal fusion cage with CSC has potential for lumbar interbody fusion.

Impact of surgical risk factors for non-union on lumbar spinal fusion outcomes using cellular bone allograft at 24-months follow-up

BACKGROUND

The current report investigates fusion rates and patient-reported outcomes following lumbar spinal surgery using cellular bone allograft (CBA) in patients with risk factors for non-union.

METHODS

A prospective, open label study was conducted in subjects undergoing lumbar spinal fusion with CBA (NCT02969616) to assess fusion success rates and patient-reported outcomes in subjects with risk factors for non-union. Subjects were categorized into low-risk (≤ 1 risk factors) and high-risk (> 1 risk factors) groups. Radiographic fusion status was evaluated by an independent review of dynamic radiographs and CT scans. Patient-reported outcome measures included quality of life (EQ-5D), Oswestry Disability Index (ODI) and Visual Analog Scales (VAS) for back and leg pain. Adverse event reporting was conducted throughout 24-months of follow-up.

RESULTS

A total of 274 subjects were enrolled: 140 subjects (51.1%) were categorized into the high-risk group (> 1 risk factor) and 134 subjects (48.9%) into the low-risk group (≤ 1 risk factors). The overall mean age at screening was 58.8 years (SD 12.5) with a higher distribution of females (63.1%) than males (36.9%). No statistical difference in fusion rates were observed between the low-risk (90.0%) and high-risk (93.9%) groups (p > 0.05). A statistically significant improvement in patient-reported outcomes (EQ-5D, ODI and VAS) was observed at all time points (p < 0.05) in both low and high-risk groups. The low-risk group showed enhanced improvement at multiple timepoints in EQ-5D, ODI, VAS-Back pain and VAS-Leg pain scores compared to the high-risk group (p < 0.05). The number of AEs were similar among risk groups.

CONCLUSIONS

This study demonstrates high fusion rates following lumbar spinal surgery using CBA, regardless of associated risk factors. Patient reported outcomes and fusion rates were not adversely affected by risk factor profiles.

TRIAL REGISTRATION

NCT02969616 (21/11/2016).

Safety of a Porous Hydroxyapatite Bone Substitute in Orthopedics and Traumatology: A Multi-Centric Clinical Study

The development of biomaterials in recent years has made it possible to broaden their use in the surgical field. Although iliac crest bone graft harvesting currently remains the gold standard as an autograft, the properties of hydroxyapatite bone substitutes appear to be beneficial. The first fundamental step to consider is the safety of using these devices. The purpose of this retrospective cohort study is to consider all the adverse events observed in our population and assess their relationships with the bone substitute device. The population analyzed consisted of patients undergoing trauma osteosynthesis with at least one implanted porous hydroxyapatite device. We considered a court of 114 patients treated at "Azienda Ospedaliera Universitaria di Ferrara-U.O. di Ortopedia e Traumatologia" in the period from January 2015 to December 2022. Upon analyzing our population, no adverse events related to the device emerged. Taking into consideration different study groups from other National Hospital Centers, no critical issues were detected except for three cases of extrusion of the biomaterial. It is necessary to clarify that bone substitutes cannot replace compliance with the correct principles linked to the biomechanics of osteosynthesis. This report outlines a safety profile for the use of these devices as bone substitutes in trauma orthopedic surgery.

Comparison of Different Osteobiologics in Terms of Imaging Modalities and Time Frames for Fusion Assessment in Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The study's primary objective was to determine how osteobiologic choice affects fusion rates in patients undergoing anterior cervical discectomy and fusion (ACDF). The study's secondary objectives were to 1) determine the optimal timing of fusion assessment following ACDF and 2) determine if osteobiologic type affects the timing and optimal modality of fusion assessment.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published from 2000 through October 2020 comparing anterior fusion in the cervical spine with various osteobiologics. Both comparative studies and case series of ≥10 patients were included.

RESULTS

A total of 74 studies met the inclusion criteria. Seventeen studies evaluated the efficacy of autograft on fusion outcomes, and 23 studies assessed the efficacy of allograft on fusion outcomes. 3 studies evaluated the efficacy of demineralized bone matrix, and seven assessed the efficacy of rhBMP-2 on fusion outcomes. Other limited studies evaluated the efficacy of ceramics and bioactive glasses on fusion outcomes, and 4 assessed the efficacy of stem cell products. Most studies utilized dynamic radiographs for the assessment of fusion. Overall, there was a general lack of supportive data to determine the optimal timing of fusion assessment meaningfully or if osteobiologic type influenced fusion timing.

CONCLUSIONS

Achieving fusion following ACDF appears to remain an intricate interplay between host biology and various surgical factors, including the selection of osteobiologics. While alternative osteobiologics to autograft exist and may produce acceptable fusion rates, limitations in study methodology prevent any definitive conclusions from existing literature.

Safety and efficacy of autologous bone marrow clot as a multifunctional bioscaffold for instrumental posterior lumbar fusion: a 1-year follow-up pilot study

Background

Bone marrow aspirate (BMA), when combined with graft substitutes, has long been introduced as a promising alternative to iliac crest bone graft in spinal fusion. However, the use of BMA is limited by the absence of a standardized procedure, a structural texture, and the potential for diffusion away from the implant site. Recently, the potential use of a new formulation of BMA, named BMA clot, has been preclinically described. In this report, we present the results of a prospective pilot clinical study aimed at evaluating the safety and efficacy of autologous vertebral BMA (vBMA) clot as a three-dimensional and multifunctional bioscaffold in instrumented posterior lumbar fusion.

Methods

Ten consecutive patients with an indication of multilevel (≤5) posterior spinal fusion due to lumbar spine degenerative diseases were included in the study and treated with vBMA. Clinical outcomes were assessed using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and EuroQoL-5L (EQ-5L) preoperatively and at 3 months and 12 months after spinal fusion. Bone fusion quality was evaluated at the 12-month follow-up using the Brantigan classification on radiography (XR) imaging. Bone density was measured on computed tomography (CT) scans at 6 and 12 months of follow-up visits at the intervertebral arches and intervertebral joint areas and expressed in Hounsfield unit (HU).

Results

The results indicate a successful posterolateral fusion rate of approximately 100% (considering levels with C, D, and E grades according to the Brantigan classification) at the 12-month follow-up, along with an increase in bone density from 6 to 12 months of follow-up. An improvement in the quality of life and health status following surgery, as assessed by clinical scores (ODI, VAS, and EQ-5L), was also observed as early as 3 months postsurgery. No adverse events related to the vBMA clot were reported.

Conclusion

This prospective pilot study demonstrates the effectiveness and safety profile of vBMA clot as an advanced bioscaffold capable of achieving posterior lumbar fusion in the treatment of degenerative spine diseases. This lays the groundwork for a larger randomized clinical study.

Twenty-four-month interim results from a prospective, single-arm clinical trial evaluating the performance and safety of cellular bone allograft in patients undergoing lumbar spinal fusion

BACKGROUND

Autologous bone grafts are the gold standard for spinal fusion; however, harvesting autologous bone can result in donor site infection, hematomas, increased operative time, and prolonged pain. Cellular bone allografts (CBAs) are a viable alternative that avoids the need for bone harvesting and may increase fusion success alone or when used as an adjunct material. The present study examined the efficacy and safety of CBA when used as an adjunct graft material to lumbar arthrodesis.

METHODS

A prospective, single-arm, multicenter clinical trial (NCT02969616) was conducted in adult subjects (> 18 years of age) undergoing lumbar spinal fusion with CBA graft (CBA used as primary (≥ 50% by volume), with augmentation up to 50%). Radiographic fusion status was assessed by an independent review of dynamic radiographs and CT scans. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), and Visual Analog Scales (VAS) score for back and leg pain. Adverse events were assessed through the 24-month follow-up period. The presented data represents an analysis of available subjects (n = 86) who completed 24 months of postoperative follow-up at the time the data was locked for analysis.

RESULTS

Postoperative 24-month fusion success was achieved in 95.3% of subjects (n = 82/86) undergoing lumbar spinal surgery. Clinical outcomes showed statistically significant improvements in ODI (46.3% improvement), VAS-Back pain (75.5% improvement), and VAS-Leg pain (85.5% improvement) (p < 0.01) scores at Month 24. No subject characteristics or surgical factors were associated with pseudoarthrosis. A favorable safety profile with a limited number of adverse events was observed.

CONCLUSIONS

The use of CBA as an adjunct graft material showed high rates of successful lumbar arthrodesis and significant improvements in pain and disability scores. CBA provides an alternative to autograft with comparable fusion success rates and clinical benefits.

TRIAL REGISTRATION

NCT02969616.

Is it feasible to treat unstable traumatic spondylolisthesis of the axis via posterior fixation without fusion?

BACKGROUND

Few studies reported treatment of unstable traumatic spondylolisthesis of the axis using posterior fixation without fusion. The aim of this study was to evaluate the results and feasibility of posterior fixation without fusion in treating unstable traumatic spondylolisthesis of the axis.

METHODS

Eleven patients with traumatic spondylolisthesis of the axis were included in this study, and posterior fixation without fusion using screw-rod system was performed for them. The clinical outcomes were assessed using the Visual Analog Scale (VAS), the Neck Disability Index (NDI), and the Odom's grading system. Plain radiography was used to measure the displacement and angulation of C2-C3, and cervical lordosis. Plain radiography and computed tomography were also used to observe the bony fusions of fracture lines and postoperative spontaneous fusion of C2-C3.

RESULTS

The mean follow up time was 24.6 months (range, 12-72 months). The VAS and NDI scores were significantly improved at the final follow-up compared with those before operation (P < 0.05), and according to Odom's criteria, 90.9% (10/11) of patients rated their level of satisfaction as excellent or good. The angulation and displacement of C2-C3, and cervical lordosis were significantly improved after operation compared with those before operation (P < 0.05), and at the final follow-up, and these radiological parameters were maintained. All patients achieved solid bony fusions of fracture lines. No operative segment instability was found in all patients during the follow-up period. Spontaneous fusion at bilateral C2-C3 facet joints was found in 11 cases, and anterior and/or posterior bony bridge of intervertebral bodies at C2-C3 was found in 9 cases.

CONCLUSIONS

Posterior fixation without fusion may be a feasible and effective option for unstable traumatic spondylolisthesis of the axis.

The safe and effective use of supercritical CO2-processed bone allografts for cervical and lumbar interbody fusion: A retrospective study

Introduction

The clinical efficacy and safety of supercritical CO₂-processed bone allografts prepared from living donors has yet to be confirmed in spinal surgery. Here we report our clinical and surgical experience of using supercritical CO₂-processed bone allografts for lumbar and cervical fusion.

Methods

Sixteen patients underwent one or two level anterior cervical discectomy and fusion and 37 patients underwent anterior retroperitoneal route lumbar fusion using bone allografts processed using supercritical CO₂ extraction combined with chemical viral inactivation. Fusion success was assessed radiographically in the immediate postoperative period and at one month, six months, one year, and three years postoperatively. Function and pain were assessed using visual analog scales, Odom's criteria, the neck disability index (NDI), and the Oswestry disability index (ODI).

Results

At a mean of 43 and 47 months postoperatively, 95.3% and 90.5% of cervical and lumbar fusion patients had radiographic evidence of bone fusion, respectively. Over 80% of patients reported good to excellent outcomes according to Odom's criteria, the perception of pain significantly decreased, and the mean NDI and ODI scores significantly improved at the last follow-up compared with before the operations. There were no safety concerns. For the cervical group, the mean NDI score improved from 26.3 ± 6.01 preoperatively to 15.00 ± 8.03 and 17.60 ± 13.95 at immediate post-op (p = 0.02) and last follow-up visits (p = 0.037) respectively. For the lumbar cases, the mean ODI score improved from 28.31 ± 6.48 preoperatively to 14.68 ± 5.49 (p < 0.0001) and 12.54 ± 10.21 (p < 00001) at immediate post-op and last follow-up visits respectively.

Conclusion

Within the limitations of this study, the use of supercritical CO₂-processed bone allografts resulted in satisfactory clinical outcomes and fusion rates with acceptable safety for both cervical and lumbar surgeries.

Quasi-static loading of glass fiber-reinforced composite cervical fusion cage

OBJECTIVES

Anterior decompression and fusion in cervical spine has become one of the most common procedures in neurosurgery. In the surgery, cervical cage implants made of different biomaterials are used. Our purpose was to create a cervical cage made of glass fiber-reinforced composite (FRC) filled with bioactive glass particles and to characterize its behavior in quasi-static compression/shear stress loading conditions.

MATERIALS AND METHODS

FRC cages (n = 6) were manufactured with 2, 4, 6, 8 and 10 layers of glass fiber laminates and thermoset dimethacrylate resin matrix resulting in wall thickness from 0.70 to 2.1 mm. Control cage was a commercial PEEK cage (CeSpaceXP) implant with asymmetrical wall thickness of up 4.0 mm. Interior of the cage was filled with glass particles of the size 500-1250 μm simulating the bioactive glass which are used in FRC cranial implants. The FRC cages were quasi-statically loaded (compressive/shear stress) at a constant speed of 1 mm/min in the air.

RESULTS

The average yield strength force (YF) of the control PEEK cage was 3483.6 N (±134.3 N). The average YFs for tested FRC cage with 2, 4, 6, 8 and 10 layers of FRC fabric varied from 1336.5 N (±403.8 N) to 7675.0 N (±670.0 N), respectively. The average ultimate forces (UF) for tested FRC cages varied from 1535.8 N (±406.2 N) to 9975.0 N (±1492.4 N). With six layers of FRC fabric, YF of the FRC cage was comparable to the PEEK implants.

CONCLUSIONS

In this study, it was demonstrated that it is possible to manufacture a cervical interbody fusion device made of FRC and filled with bioactive glass with proper load bearing capacities. Because of physical properties of FRC-bioactive glass, the FRC cage might have some advances compared to the state-of-the-art cages, like faster bony union and smaller rate of subsidence, which will be studied in the future.

Ceramic bone graft substitute (Mg-HA) in spinal fusion: A prospective pilot study

Background: Iliac crest bone graft (ICBG) is considered the gold standard for spine surgical procedures to achieve a successful fusion due to its known osteoinductive and osteoconductive properties. However, complications related to harvesting procedure and donor site morbidity have been largely reported in the literature, favoring the development of a wide range of alternative products to be used as bone graft extenders or substitutes for spine fusion. Among all, ceramic-based biomaterials have been widely studied and employed in the last years as bone graft substitutes. Methods: We report here the results of a prospective pilot study aimed to evaluating the grade of ossification obtained by the use of an Mg-doped hydroxyapatite (HA) product to achieve postero-lateral fusion in degenerative spine diseases. Results: Results show a successful degree of fusion of about 62% at the 12-month follow-up and an improvement of quality of life and health status following surgery, as evaluated by clinical scores (ODI, VAS, and EQ-5L). No adverse events related to the material were reported. Conclusion: The present pilot study shows the effectiveness and the safety profile of an Mg-doped HA bone graft substitute used to achieve postero-lateral fusion in the treatment of degenerative spine diseases, laying down the basis for further larger clinical investigations.

Masquelet's induced membrane technique associated with Reamer Irrigation Aspiration grafting and intramedullary Nailing (MaRIAN) for chronic diaphyseal osteomyelitis of the lower limb

INTRODUCTION

Masquelet's induced membrane technique offers a definitive contribution to the treatment of diaphyseal osteomyelitis. To overcome its drawbacks while maintaining its principles, technical modifications have been proposed: antibiotic cement, femoral intramedullary autograft harvested by RIA (Reamer Irrigation Aspiration) and interlocking nails.

MATERIAL AND METHOD

This retrospective study gathered patients with chronic osteomyelitis of the femur or tibia. The first surgical stage consisted of bone resection in the healthy zone and use of a gentamicin cement spacer to fill the bone defect. The second stage consisted of the placement of a statically locked intramedullary nail associated with a bone autograft using the RIA technique.

RESULTS

Among this group of 12 men with diaphyseal osteomyelitis; 9 tibial and 2 femoral, and 1 knee nonunion, the mean bone defect was 7.3cm (±6.7). The mean time between the 2 stages was 2.7months (±3) with a mean antibiotic period of 3.25weeks (±3). There was a femoral diaphyseal fracture at the donor site, and a wrong trajectory intraoperatively during the RIA. Two patients with tibial nonunion presented with nail rupture without septic recurrence. A septic recurrence was healed by removal of the nail. At a minimum follow-up of 18months, with an average of 5years, consolidation was complete without infectious recurrence. Despite the statistical weakness related to the size of the cohort, the resumption of early weight bearing (OR=-7.68 95% CI [-13.33 to -2.08] (p=0.01)) and nail dynamization seemed to have an impact on the formation of complete consolidation (OR=-0.86 95% CI [-1.39 to -0.33] (p=0.007)).

DISCUSSION AND CONCLUSION

This short series, compared to the literature, demonstrated that the proposed technical modifications improved the overall management of this rare and challenging condition while maintaining the reliability of the original technique. Dynamization was also seen to be of particular interest.

LEVEL OF EVIDENCE

IV, retrospective study.

Twelve-Month Results from a Prospective Clinical Study Evaluating the Efficacy and Safety of Cellular Bone Allograft in Subjects Undergoing Lumbar Spinal Fusion

BACKGROUND

While autologous bone grafts remain the gold standard for spinal fusion procedures, harvesting autologous bone is associated with significant complications, including donor site infection, hematomas, increased operative time, and prolonged pain. Cellular bone allograft (CBA) presents an alternative to autologous bone harvesting, with a favorable efficacy and safety profile. The current study further investigates CBA as an adjunct to lumbar spinal fusion procedures.

METHODS

A prospective, multicenter, open-label clinical study was conducted in subjects undergoing lumbar spinal fusion with CBA (NCT02969616). Radiographic fusion status was assessed by an independent review of dynamic radiographs and CT scans. Clinical outcome measures included the Oswestry Disability Index (ODI) and visual analogue scale (VAS) for back and leg pain. Adverse-event reporting was conducted throughout 12 months of follow-up. Available subject data at 12 months were analyzed.

RESULTS

A total of 274 subjects were enrolled into the study, with available data from 201 subjects (73.3%) who completed 12 months of postoperative radiographic and clinical evaluation at the time of analysis. Subjects had a mean age of 60.2 ± 11.5 years. A higher number of women (n = 124, 61.7%) than men (n = 77, 38.3%) were enrolled, with a collective mean BMI of 30.6 + 6.5 kg/m² (range 18.0-51.4). At month 12, successful fusion was achieved in 90.5% of subjects. A significant (<i>p</i> &amp;lt; 0.001) improvement in ODI, VAS-back, and VAS-leg clinical outcomes was also observed compared to baseline scores. One adverse event related to CBA (postoperative radiculopathy) was reported, with surgical exploration demonstrating interbody extrusion of graft material. This subject reported successful fusion at month 12.

CONCLUSIONS

CBA represents a viable substitute for harvesting of autograft alone with a high rate of successful fusion and significant improvements in subject-reported outcomes, such as pain and disability. Positive benefit was observed in subjects reporting single and multiple risk factors for pseudoarthrosis.

History of Bone Grafts in Spine Surgery

Bone grafting replaces damaged or missing bone with new bone and is used for surgical arthrodesis. Patients benefit from a huge variety of bone graft techniques and options for spinal fusions. This article reviews the rich history of bone grafts in surgery with particular emphasis on spinal fusion. During the early years of bone grafting in spine surgery, bone grafts were used on tuberculosis patients, and the structural support of the graft was most the important consideration. Between 1960 and 2000, many advances were made, specifically in the use of bone graft substitutes. The field of bone grafts in spine surgery has evolved rapidly since first described.

Preclinical Safety of a 3D-Printed Hydroxyapatite-Demineralized Bone Matrix Scaffold for Spinal Fusion

STUDY DESIGN

Prospective, randomized, controlled preclinical study.

OBJECTIVE

The objective of this study was to compare the host inflammatory response of our previously described hyperelastic, 3D-printed (3DP) hydroxyapatite (HA)-demineralized bone matrix (DBM) composite scaffold to the response elicited with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a preclinical rat posterolateral lumbar fusion model.

SUMMARY OF BACKGROUND DATA

Our group previously found that this 3D-printed HA-DBM composite material shows promise as a bone graft substitute in a preclinical rodent model, but its safety profile had yet to be assessed.

METHODS

Sixty female Sprague-Dawley rats underwent bilateral posterolateral intertransverse lumbar spinal fusion using with the following implants: 1) type I absorbable collagen sponge (ACS) alone; 2) 10 μg rhBMP-2/ACS; or 3) the 3DP HA-DBM composite scaffold (n = 20). The host inflammatory response was assessed using magnetic resonance imaging, while the local and circulating cytokine expression levels were evaluated by enzyme-linked immunosorbent assays at subsequent postoperative time points (N = 5/time point).

RESULTS

At both 2 and 5 days postoperatively, treatment with the HA-DBM scaffold produced significantly less soft tissue edema at the fusion bed site relative to rhBMP-2-treated animals as quantified on magnetic resonance imaging. At every postoperative time point evaluated, the level of soft tissue edema in HA-DBM-treated animals was comparable to that of the ACS control group. At 2 days postoperatively, serum concentrations of tumor necrosis factor-α and macrophage chemoattractant protein-1 were significantly elevated in the rhBMP-2 treatment group relative to ACS controls, whereas these cytokines were not elevated in the HA-DBM-treated animals.

CONCLUSION

The 3D-printed HA-DBM composite induces a significantly reduced host inflammatory response in a preclinical spinal fusion model relative to rhBMP-2.Level of Evidence: N/A.

Bone Marrow Aspirate in Spine Surgery: Case Series and Review of the Literature

Background With the modernization of biotechnology, there has been a concerted effort to create novel biomaterials to promote arthrodesis for spine surgery. The novel use of the stem cells from bone marrow aspirate (BMA) to augment spine surgery is a burgeoning field because these cells are considered to be both osteoinductive and osteogenic. We sought to review the evidence behind the use of BMAs in spinal fusions and report the results of our own case series. Methods PubMed and EMBASE databases were searched for studies that investigated the use of stem cells for spine surgery. For our own case series, the medical records of 150 consecutive patients who underwent a lumbar spinal fusion with BMA were retrospectively reviewed for adverse events (AEs) for up to two years after surgery. Results In our case series, there were no AEs identified in 49% of our patients. Of the identified AEs, 61% were unrelated to the use of BMA (e.g., UTI and heart failure), with the remaining 39% likely unrelated to its use (e.g., back pain and anemia). There was a 92.8% arthrodesis rate with the use of BMA. Conclusions We reviewed the rationale, basic science, and clinical science for BMA usage in spine surgery and concluded that BMA is safe for use in spine surgery and is associated with a high rate of arthrodesis.

Regional anesthesia for nonunion surgery with iliac crest bone grafting results in an increase in same day discharge

INTRODUCTION

The purpose of this study was to evaluate the outcomes of fracture nonunion repair with autogenous iliac crest bone graft (ICBG) under regional anesthesia alone or in combination with other techniques compared to other anesthesia techniques.

MATERIALS AND METHODS

Overall, 137 patients were identified who underwent ICBG as part of a repair of a long bone fracture nonunion between January 1, 2013 and October 1, 2020. Surgical and anesthetic records were reviewed to classify patients by anesthesia type. General, spinal, and regional anesthetics were used as either the primary anesthetic or as a combination of regional nerve block with general or spinal anesthesia.

RESULTS

Administration of regional anesthesia alone or in combination with general or spinal anesthesia (RA) and general or spinal anesthesia only (GS) groups differed in nonunion site distribution (p < 0.001). RA patients were discharged the same day more often than GS patients (30.9% vs 10.0%, p = 0.009) and experienced fewer postoperative complications (p = 0.021). The RA group achieved union sooner than the GS group (by 5.3 ± 3.2 months vs. by 6.8 ± 3.2 months, p = 0.006). Mean morphine equivalent dose was similar between groups (p = 0.23). Regional anesthesia use increased from 2013 to 2020, and same day discharge surgeries simultaneously increased over the same time period.

CONCLUSION

Regional anesthesia use increased in nonunion repair surgery with ICBG from 2013 to 2020. This was associated with an increase in same day discharge, sooner time to union, and decreased postoperative complications. There was not a need for increased opioid prescription in patients that underwent regional anesthesia.

Autologous Stem Cells in Cervical Spine Fusion

STUDY DESIGN

Systematic review.

OBJECTIVES

To systematically review, critically appraise and synthesize evidence on use of stem cells from autologous stem cells from bone marrow aspirate, adipose, or any other autologous sources for fusion in the cervical spine compared with other graft materials.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and through February 20, 2020 for EMBASE and ClinicalTrials.gov comparing autologous cell sources for cervical spine fusion to other graft options.

RESULTS

From 36 potentially relevant citations identified, 10 studies on cervical fusion met the inclusion criteria set a priori. Two retrospective cohort studies, one comparing cancellous bone marrow (CBM) versus hydroxyapatite (HA) and the other bone marrow aspirate (BMA) combined with autograft and HA versus autograft and HA alone, were identified. No statistical differences were seen between groups in either study for improvement in function, symptoms, or fusion; however, in the study evaluating BMA, the authors reported a statistically greater fusion rate and probability of fusion over time in the BMA versus the non-BMA group. Across case series evaluating BMA, authors reported improved function and pain and fusion ranged from 84% to 100% across the studies. In general, complications were poorly reported.

CONCLUSIONS

The overall quality (strength) of evidence of effectiveness and safety of autologous BMA for cervical arthrodesis in the current available literature was very low. Based on currently available data, firm conclusions regarding the effectiveness or safety of BMA in cervical fusions cannot be made.

Clinical and radiographic outcomes using third-generation bioactive glass as a bone graft substitute for multi-level anterior cervical discectomy and fusion-a retrospective case series study

Background

Bioactive glasses have unique bone forming properties that have been used as a bone graft substitute for anterior cervical discectomy and fusions (ACDFs). Bone graft substitutes are used for achieving fusion while simultaneously avoiding donor site morbidity of iliac crest autograft. In this study, our principal intention is to assess the clinical and radiographic outcomes in patients with multi-level cervical disc disease undergoing ACDF using a third-generation bioactive glass as a bone graft substitute.

Methods

A retrospective case series study was performed of patients who underwent primary multi-level instrumented fusions for degenerative cervical disc disease with bioactive glass bone graft substitute between May 2016 and December 2017 by a single fellowship-trained spine surgeon. All patients were treated with a porous PEEK interbody spacer and with a third-generation bioactive glass synthetic bone graft substitute. Patients were assessed pre-operatively, immediately following surgery, and at 3, 6, 12, and 24 months. Accepted standard outcome measures were applied to evaluate preoperative and postoperative metrics, including Visual Analog Scale neck pain and arm pain, and Neck Disability Index. Dynamic lateral radiographs were used to assess sagittal alignment, disc space height, arthrodesis status, osseous integration, and implant migration. Sagittal plane angulation was measured by Cobb's criteria.

Results

Thirty-nine patients underwent multi-level instrumented fusions: seventeen (43%) were two-level; 12 (31%) were three-level; 9 (23%) were four-level; and 1 (3%) was five-levels. All patients were followed for a minimum of 6 months for mean of 16.0 months (range, 6 to 36 months); none were lost to follow-up. Significant improvements from preoperative scores in Neck Disability Index scores as well as neck and arm visual analog scale pain scores were realized. All patients either maintained or improved their neurological status. Radiographically, all patients were fused by 6 months postoperatively and showed improvement in fusion segment lordosis (Pre-Post and Pre-Final P<0.001), C2-C7 lordosis angle (Pre-Post and Pre-Final P<0.001), T1 slope (Pre-Post P=0.01, Pre-Final P=0.07) and maintenance of disc height (Post-Final P=0.02). There were no adverse events, infections, or reoperations.

Conclusions

Third-generation bioactive glass synthetic graft is a viable alternative to allograft or autograft in the setting of multi-level instrumented fusions for achieving improved clinical and radiographic outcomes.

Clinical study on repair of metacarpal bone defects using titanium alloy implantation and autologous bone grafting

Due to various limitations in the use of autologous bone and allogeneic bone in the repair of bone defects, the use of synthetic bone graft substitute has become a hot topic in orthopedic surgery and repair medicine. A total of 53 patients treated for trauma-induced metacarpal bone defects were recruited. These patients were divided into the TiAl₆V₄ titanium alloy implantation group (group A) and the autologous bone graft group (group B). The symptoms of patients in the two groups were closely observed and followed up. The operation time, time to bone fusion, post-surgical pain [visual analog scale (VAS) scores], hand function recovery [total active flexion scale (TAFS) scores] and complications were compared between the two groups. Following surgery, none of the patients had necrosis of fingers or bone non-union. The recovery was rated as excellent and good in up to 91.6% of patients, indicating high clinical efficacy. Compared with the use of autologous bone grafting as the gold standard (group B), there was no significant difference in the excellent and good recovery rate based on TAFS scores at 16 weeks after surgery (91.7 vs. 89.7%, P>0.05), and there was also no significant difference in the incidence of post-operative complications (33.3 vs. 41.3%, P>0.05). The operation time (82.08±6.64 min), time to bone fusion (7.75±1.73 weeks) and VAS scores at 3 days after surgery were all significantly lower in group A than in group B (P<0.05). The values of group B were 104.69±8.63 min, 9.17±2.78 weeks and [5(5, 6)], respectively. However, the hospitalization cost (22,657.8±1,595.4Ұ) was significantly higher than that in group B (14,808.2±2,291.3Ұ; P<0.05). In conclusion, the use of titanium alloy implantation may avoid new injury to the donor site, reduce the operation time and post-operative pain and accelerate bone fusion. Therefore, this method is worthy of popularization for defective bone reconstruction and recovery in the clinic.

Nanostructured Biomaterials for Bone Regeneration

This review article addresses the various aspects of nano-biomaterials used in or being pursued for the purpose of promoting bone regeneration. In the last decade, significant growth in the fields of polymer sciences, nanotechnology, and biotechnology has resulted in the development of new nano-biomaterials. These are extensively explored as drug delivery carriers and as implantable devices. At the interface of nanomaterials and biological systems, the organic and synthetic worlds have merged over the past two decades, forming a new scientific field incorporating nano-material design for biological applications. For this field to evolve, there is a need to understand the dynamic forces and molecular components that shape these interactions and influence function, while also considering safety. While there is still much to learn about the bio-physicochemical interactions at the interface, we are at a point where pockets of accumulated knowledge can provide a conceptual framework to guide further exploration and inform future product development. This review is intended as a resource for academics, scientists, and physicians working in the field of orthopedics and bone repair.

Ceramic Biologics for Bony Fusion-a Journey from First to Third Generations

PURPOSE OF REVIEW

To provide information on characteristics and use of various ceramics in spine fusion and future directions.

RECENT FINDINGS

In most recent years, focus has been shifted to the use of ceramics in minimally invasive surgeries or implementation of nanostructured surface modification features to promote osteoinductive properties. In addition, effort has been placed on the development of bioactive synthetics. Core characteristic of bioactive synthetics is that they undergo change to simulate a beneficial response within the bone. This change is based on chemical reaction and various chemical elements present in the bioactive ceramics. Recently, a synthetic 15-amino acid polypeptide bound to an anorganic bone material which mimics the cell-binding domain of type-I collagen opened a possibility for osteogenic and osteoinductive roles of this hybrid graft material. Ceramics have been present in the spine fusion arena for several decades; however, their use has been limited. The major obstacle in published literature is small sample size resulting in low evidence and a potential for bias. In addition, different physical and chemical properties of various ceramics further contribute to the limited evidence. Although ceramics have several disadvantages, they still hold a great promise as a value-based graft material with being easily available, relatively inexpensive, and non-immunogenic.

Iliac Crest Bone Graft for Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Prospective Analysis of Inpatient Pain, Narcotics Consumption, and Costs

STUDY DESIGN

Retrospective Analysis OBJECTIVE.: The aim of this study was to determine whether an association between increased acute pain, postoperative time, and direct hospital costs exists between the use of iliac crest bone grafting (ICBG) and bone morphogenic protein (BMP)-2 following a primary, single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

SUMMARY OF BACKGROUND DATA

ICBG has been associated with enhanced fusion rates. Concerns have been raised in regards to increased operative time and postoperative pain. The advantages of ICBG compared to other spinal fusion adjuncts have been debated.

METHODS

Prospective, consecutive analysis of patients undergoing primary, single-level MIS TLIF with ICBG was compared to a historical cohort of consecutive patients that received BMP-2. Operative characteristics were compared between groups using χ analysis or independent t test for categorical and continuous variables, respectively. Postoperative inpatient pain was measured using the Visual Analog Scale, and inpatient narcotics consumption was quantified as oral morphine equivalents. Outcomes were compared between groups using multivariate regression controlling for preoperative characteristics.

RESULTS

A total of 98 patients were included in this analysis, 49 in each cohort. No significant differences were noted between cohorts with exception to sex (Females: ICBG, 53.06% vs. BMP-2, 32.65%, P = 0.041). There was a significant increase in operative time (14.53 minutes, P = 0.006) and estimated blood loss (16.64 mL, P = 0.014) in the ICBG cohort. Narcotics consumption was similar between groups on postoperative days 0 and 1. ICBG was associated with decreased total direct costs ($19,315 vs. $21,645, P < 0.001) as compared to BMP-2.

CONCLUSION

Patients undergoing MIS TLIF with ICBG experienced increases in operative time and estimated blood loss that were not clinically significant. Furthermore, iliac crest harvesting did not result in an increase in acute pain or narcotics consumption. Further follow-up is necessary to determine the associated arthrodesis rates and long-term outcomes between each cohort.

LEVEL OF EVIDENCE

3.

Transforaminal Lumbar Interbody Fusion With Viable Allograft: 75 Consecutive Cases at 12-Month Follow-up

Background

When conservative treatments fail to alleviate the discomfort of abnormal motion, spinal fusion has been shown to provide symptomatic treatment for spinal instability, stenosis, spondylolisthesis, and symptomatic degenerative disc disease. The trend and rates of fusion over the past few years have been dramatic in the United States. Accompanying that higher incidence has been the shifting from traditional open surgery to minimally invasive techniques to reduce scar tissue formation, extent of muscle stripping, and muscle retraction which all have been shown to adversely affect outcomes. Other reasons supporting the widespread transition to minimally invasive surgical (MIS) techniques include decreased postoperative pain, decreased intraoperative blood loss, shorter postoperative hospital stay, faster return to normal activity, and reduced reoperation rates. Spinal fusion procedures rely on a bony fusion substrate in addition to fixation hardware. While available grafting options include autogenous, allogeneic, and synthetic materials, recent interest in viable allograft material with living cells has drawn attention and attraction for incorporating a biologic basis for regenerative consideration. A recent viable allograft, complete with cellular and designated bone carrier (VIA Graft, Vivex Biomedical, Marietta, Georgia) has been developed. This study represents a retrospective review of a single-practice, single-surgeon evaluation of the product in 75 consecutive patients for fusion by computed tomography (CT) and radiographic evaluation at 12 months in conjunction with a MIS approach. Viable allograft was used to fill the peri-implant space, and central implant lumen was filled with a cancellous bone sponge soaked in perivertebral bone marrow. Posterolateral supplementation was attained with beta-tricalcium phosphate as a bulking agent.

Methods

A retrospective review identified patients treated for both primary and revision surgery who received VIA Graft cellular bone matrix material in minimally invasive interbody fusion (MIS-TLIF) with a minimum of 12-month follow up. The patient diagnoses included radiculopathy in all instances and varied collateral indications such as foraminal collapse, recurrent disc herniation, and spondylolisthesis to which pain and morbidity had been unresolved by conservative treatment. Adverse events including infection, revisions, and evidence of immune response were evaluated and patient comorbidities defined for the entire population of patients. Patient fusion status was assessed using thin slice CT by 2 independent radiologists separate from the surgeon. There were 75 consecutive adult patients with degenerative conditions of the lumbar spine who underwent MIS-TLIF surgery of which 40 (53%) were male and 35 (47%) were female. Mean age, height, and weight were 58 years, 170.18 cm (67 in), and 88.45 kg (195 lbs), respectively. The mean body mass index was 30. There were 16 patients (21%) who smoked and 12 (16%) with a history of diabetes. Independent blinded review of fusion was obtained by a board certified musculoskeletal radiologist and an experienced board certified orthopaedic surgeon to assess patient fusion status. Spinal segments were deemed fused if 12-month CT scans demonstrated evidence of bridging bone at the fusion site without observed motion on flexion-extension radiographs. Findings such as osteolysis around the implant or pedicle screws, extensive endplate cystic changes, or linear defects parallel to the endplates through intradiscal new bone formation were interpreted as signs of pseudarthrosis. Interobserver and intraobserver error and κ assessments were analyzed to assure agreement in the CT outcomes assessment where interpretation of κ were as follows: <0.00 = poor agreement, 0.00-0.20 = slight agreement, 0.21-0.40 = fair agreement, 0.41-0.60 = moderate agreement, 0.61-0.80 = substantial agreement, and 0.81-1.00 = almost perfect agreement. Differences were resolved by consensus amongst the observers.

Results

In total, 96% of the 75 patients with a total of 85 levels (96.5% of levels treated) achieved a fusion at 12 months. There were no perioperative or latent complications and no transfusions in all 75 patients.

Conclusions

In this population, 96% of the patients treated achieved the surgical objective in 96.5% of the levels treated.

Level of Evidence

IV.

Clinical Relevance

The high rate of fusion, the lack of secondary morbidity with autologous bone harvest, and the clinical success account for the benefits of viable allograft matrix for MIS-TLIF use.

Complication Rates in Posterior Lumbar Interbody Fusion (PLIF) Surgery With Human Bone Morphogenetic Protein 2: Medicare Population

STUDY DESIGN

Retrospective cohort study among Medicare beneficiaries who underwent posterior lumbar interbody fusion (PLIF) surgery.

OBJECTIVE

To identify the complication rates associated with the use of bone morphogenetic protein 2 (BMP2) in PLIF. Human BMP2 is commonly used in the "off-label" manner for various types of spine fusion procedures, including PLIF. However, recent studies have reported potential complications associated with the recombinant human BMP2 (rhBMP2) use in the posterior approach.

METHODS

Medicare records within the PearlDiver database were queried for patients undergoing PLIF procedure with and without rhBMP2 between 2005 and 2010. We evaluated complications within 1 year postoperatively. Chi-square was used to compare the complication rates between the 2 groups.

RESULTS

A total of 8609 patients underwent PLIF procedure with or without rhBMP2. Individual complication rates in the rhBMP2 group ranged from 0.45% to 7.68% compared with 0.65% to 10.99 in the non-rhBMP2 group. Complication rates for cardiac, pulmonary, lumbosacral neuritis, infection, wound, and urinary tract (include acute kidney failure and post-operative complications) were significantly lower in the rhBMP2 group (P < .05). There was no difference in the rates of central nervous system complications or radiculitis between the 2 groups.

CONCLUSION

Our data showed that the patients who received rhBMP2 had lower complication rates compared to the non-rhBMP2 group. However, use of rhBMP2 was associated with a higher rate of pseudarthrosis. We did not observe any difference in radiculitis and central nervous system complications between the groups.

Delayed union of humeral shaft fractures: comparison of autograft with and without platelet-rich plasma treatment: a randomized, single blinded clinical trial

INTRODUCTION

Despite an adequate orthopedic treatment with functional bracing, some patients develop a delayed union in humeral shaft fractures. The objective of the present study was to determine the bone consolidation time among patients with delayed union of diaphyseal humeral fractures who were managed with locking compression plate (LCP) fixation combined with an iliac crest autograft using platelet-rich plasma (PRP) as a co-adjuvant.

MATERIALS AND METHODS

This study was a controlled, randomized, experimental, longitudinal, comparative, prospective, blind clinical trial. Patients diagnosed with delayed union of a diaphyseal humeral fracture with at least 4 months of evolution were treated with an open reduction and LCP osteosynthesis combined with an iliac crest autograft. The experimental group also received PRP. The patients were assessed radiographically until 36 weeks of evolution.

RESULTS

A total of 16 patients were included. Both groups had similar demographic characteristics. The patients treated with PRP had an earlier beginning of bone consolidation. Furthermore, these same patients exhibited bone consolidation at 19.9 weeks, on average, in contrast to 25.4 weeks in the control group.

CONCLUSIONS

The use of PRP promotes earlier bone consolidation in patients with delayed union of the humeral shaft.

Building better bone: The weaving of biologic and engineering strategies for managing bone loss

Segmental bone loss remains a challenging clinical problem for orthopaedic trauma surgeons. In addition to the missing bone itself, the local tissues (soft tissue, vascular) are often highly traumatized as well, resulting in a less than ideal environment for bone regeneration. As a result, attempts at limb salvage become a highly expensive endeavor, often requiring multiple operations and necessitating the use of every available strategy (autograft, allograft, bone graft substitution, Masquelet, bone transport, etc.) to achieve bony union. A cost-sensitive, functionally appropriate, and volumetrically adequate engineered substitute would be practice-changing for orthopaedic trauma surgeons and these patients with difficult clinical problems. In tissue engineering and bone regeneration fields, numerous research efforts continue to make progress toward new therapeutic interventions for segmental bone loss, including novel biomaterial development as well as cell-based strategies. Despite an ever-evolving literature base of these new therapeutic and engineered options, there remains a disconnect with the clinical practice, with very few translating into clinical use. A symposium entitled "Building better bone: The weaving of biologic and engineering strategies for managing bone loss," was presented at the 2016 Orthopaedic Research Society Conference to further explore this engineering-clinical disconnect, by surveying basic, translational, and clinical researchers along with orthopaedic surgeons and proposing ideas for pushing the bar forward in the field of segmental bone loss. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1855-1864, 2017.

A new bioinspired collagen-hydroxyapatite bone graft substitute in adult scoliosis surgery: results at 3-year follow-up

Background

Spinal fusion is a common procedure used for surgical treatment of spinal deformity. In recent years, many bone graft substitutes (BGS) have been developed to provide good arthrodesis when the available autologous bone harvested from the patient is not enough. The aim of this study was to analyze the use of a new-generation composite material (RegenOss) made of Mg-hydroxyapatite nanoparticles nucleated on type I collagen to obtain long posterolateral fusion in adult scoliosis surgery.

Methods

A total of 41 patients who underwent spinal fusion for the treatment of adult scoliosis were retrospectively analyzed. According to Lenke classification, visual analog scale (VAS) score and Oswestry Disability Index (ODI) score, radiographic rates of bone union were evaluated before surgery and at 6, 12 and 36 months of follow-up. Fusion was considered to be successful when criteria for Lenke grade A or B were satisfied. Patient-related risk factors were considered for the evaluation of the final outcome.

Results

At 36-month follow-up, radiographic evidence of spinal fusion was present in the majority of patients (95.1%). A time-dependent statistically significant improvement was evidenced after surgery for all clinical outcomes evaluated. Based on the demographic data collected, there were no statistically significant factors determining fusion. The correction of deformity was maintained at different time points. No intraoperative or postoperative complications were recorded.

Conclusions

The present study demonstrated that RegenOss can safely be used to achieve good arthrodesis when associated with autologous bone graft to obtain long spinal fusion in the treatment of adult scoliosis.

Higher Modified Charlson Index Scores Are Associated With Increased Incidence of Complications, Transfusion Events, and Length of Stay Following Revision Hip Arthroplasty

BACKGROUND

Revision total hip arthroplasty (RHA) has been associated with greater morbidity and length of stay (LOS) compared to primary total hip arthroplasty. Despite this, few validated metrics exist for risk stratification in RHA cohorts. The Charlson Comorbidity Index (CCI) has been associated with complications in total hip arthroplasty, but its utility in revision surgery remains unexplored. The purpose of this study was to examine the relationship between preoperative CCI and a variety of outcome metrics following RHA.

METHODS

The National Surgical Quality Improvement Program database was used to identify all patients undergoing aseptic RHA between 2006 and 2013. A variety of demographics and perioperative variables were collected. Modified CCI scores were computed for each patient based on a validated formula incorporating comorbidities found in the National Surgical Quality Improvement Program database. Outcome variables of interest included mortality, major postoperative complications, minor adverse events, incidence of transfusion, and prolonged LOS. Perioperative factors were tested for association with these outcomes using bivariate analysis and significant variables were then incorporated into a logistic regression model to explore the relationship between preoperative CCI scores and postoperative events.

RESULTS

In a multivariable regression model controlling for the significant perioperative variables, operative time, and American Society of Anesthesiologists classification, higher CCI scores were significantly associated with mortality (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.64-2.18, P < .001), major complications (OR 1.12, 95% CI 1.05-1.20, P = .001), minor complications (OR 1.53, 95% CI 1.39-1.69, P < .001), transfusions (OR 1.14, 95% CI 1.09-1.20, P < .001), and prolonged LOS (OR 1.32, 95% CI 1.26-1.39, P < .001).

CONCLUSION

Higher preoperative CCI scores were independent risk factors for numerous complications. This highlights the potential utility of the CCI in risk stratification for RHA populations.

Long-Segment Fusion for Adult Spinal Deformity Correction Using Low-Dose Recombinant Human Bone Morphogenetic Protein-2

BACKGROUND:

Although use of very high-dose recombinant human bone morphogenetic protein-2 (rhBMP-2) has been reported to markedly improve fusion rates in adult spinal deformity (ASD) surgery, most centers use much lower doses due to cost constraints. How effective these lower doses are for fusion enhancement remains unclear.

OBJECTIVE:

To assess fusion rates using relatively low-dose rhBMP-2 for ASD surgery.

METHODS:

This was a retrospective review of consecutive ASD patients that underwent thoracic to sacral fusion. Patients that achieved 2-year follow-up were analyzed. Impact of patient and surgical factors on fusion rate was assessed, and fusion rates were compared with historical cohorts.

RESULTS:

Of 219 patients, 172 (78.5%) achieved 2-year follow-up and were analyzed. Using an average rhBMP-2 dose of 3.1 mg/level (average total dose = 35.9 mg/case), the 2-year fusion rate was 73.8%. Cancellous allograft, local autograft, and very limited iliac crest bone graft (&lt;20 mL, obtained during iliac bolt placement) were also used. On multivariate analysis, female sex was associated with a higher fusion rate, whereas age, comorbidity score, deformity type, and 3-column osteotomy were not. There were no complications directly attributable to rhBMP-2.

CONCLUSION:

Fusion rates for ASD using low-dose rhBMP-2 were comparable to those reported for iliac crest bone graft but lower than for high-dose rhBMP-2. Importantly, there were substantial differences between patients in the present series and those in the historical comparison groups that could not be fully adjusted for based on available data. Prospective evaluation of rhBMP-2 dosing for ASD surgery is warranted to define the most appropriate dose that balances benefits, risks, and costs.

Synthetic bone graft versus autograft or allograft for spinal fusion: a systematic review

The purpose of this review was to compare the efficacy and safety of synthetic bone graft substitutes versus autograft or allograft for the treatment of lumbar and cervical spinal degenerative diseases. Multiple major medical reference databases were searched for studies that evaluated spinal fusion using synthetic bone graft substitutes (either alone or with an autograft or allograft) compared with autograft and allograft. Randomized controlled trials (RCT) and cohort studies with more than 10 patients were included. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. The search yielded 214 citations with 27 studies that met the inclusion criteria. For the patients with lumbar spinal degenerative disease, data from 19 comparative studies were included: 3 RCTs, 12 prospective, and 4 retrospective studies. Hydroxyapatite (HA), HA+collagen, β-tricalcium phosphate (β-TCP), calcium sulfate, or polymethylmethacrylate (PMMA) were used. Overall, there were no differences between the treatment groups in terms of fusion, functional outcomes, or complications, except in 1 study that found higher rates of HA graft absorption. For the patients with cervical degenerative conditions, data from 8 comparative studies were included: 4 RCTs and 4 cohort studies (1 prospective and 3 retrospective studies). Synthetic grafts included HA, β-TCP/HA, PMMA, and biocompatible osteoconductive polymer (BOP). The PMMA and BOP grafts led to lower fusion rates, and PMMA, HA, and BOP had greater risks of graft fragmentation, settling, and instrumentation problems compared with iliac crest bone graft. The overall quality of evidence evaluating the potential use and superiority of the synthetic biological materials for lumbar and cervical fusion in this systematic review was low or insufficient, largely due to the high potential for bias and small sample sizes. Thus, definitive conclusions or recommendations regarding the use of these synthetic materials should be made cautiously and within the context of the limitations of the evidence.

The Effect of Anesthetic Type on Outcomes of Hip Fracture Surgery: A Nationwide Population-Based Study

Hip fractures are a global public health problem. During surgery following hip fractures, both general and regional anesthesia are used, but which type of anesthesia offers a better outcome remains controversial. There has been little research evaluating different anesthetic types on mortality and readmission rates for hip fracture surgery using nationwide population-based data.We used nationwide population-based data to examine the effect of anesthetic type on mortality and readmission rates for hip fracture surgery.Retrospective observational study.General acute care hospitals throughout Taiwan.A total of 17,189 patients hospitalized for hip fracture surgery in 2011.Generalized estimating equation models with propensity score weighting were performed after adjustment for patient, surgeon, and hospital characteristics to examine the associations of anesthesia type with 30-day all-cause mortality, 30-day all-cause readmission, and 30-day specific-cause readmission (including surgical site infection, sepsis, acute respiratory failure, acute stroke, acute myocardial infarction, acute renal failure, deep vein thrombosis, pneumonia, and urinary tract infection).Of 17,189 patients, 11,153 (64.9%) received regional anesthesia and 6036 (35.1%) received general anesthesia. Overall, the 30-day mortality rate was 1.7%, and the 30-day readmission rate was 12.3%. Regional anesthesia was not associated with decreased 30-day all-cause mortality (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.67-1.18, P = 0.409), but associated with decreased 30-day all-cause readmission and surgical site infection readmission relative to general anesthesia (OR 0.83, 95% CI 0.75-0.93, P = 0.001 and OR 0.69, 95% CI 0.49-0.97, P = 0.031).Regional anesthesia is not associated with 30-day mortality, but is associated with lower 30-day all-cause and surgical site infection readmission compared with general anesthesia for hip fracture surgery.

Bone Grafting: Sourcing, Timing, Strategies, and Alternatives

Acute fractures, nonunions, and nonunions with bone defects or osteomyelitis often need bone graft to facilitate union. There are several factors to consider when it is determined that a bone graft is needed. These factors include the source of the bone graft (autograft vs. allograft), proper timing for placement of the bone graft, strategies to avoid further complications (particularly in the setting of osteomyelitis), and with the development of a variety of bone graft substitutes, whether alternatives to autograft are available and appropriate for the task at hand. Autograft bone has commonly been referred to as the "gold standard" of bone grafts, against which the efficacy of other grafts has been measured. The best timing for when to place a bone graft or substitute is also somewhat controversial, particularly after an open fracture or a potentially contaminated bed. The treatment of infected nonunions, particularly those that require a graft to facilitate healing, can be quite challenging. Typically, the infection is completely eradicated before placement of a bone graft, but achieving a sterile bed and the timing of a bone graft require strategic thinking and planning. This review outlines the benefits of autografts, the most suitable sites for harvesting bone grafts, the timing of bone graft procedures, the potential risks and benefits of grafting in the face of infection, and the currently available bone graft extenders.