The sacral screw placement depending on morphological and anatomical peculiarities.

PURPOSE: Various pathologies of the lumbosacral junction require fusion of the L5/S1 segment. However, pseudarthroses, which often come along with sacral screw loosening, are problematic. The aim of the present investigation was to elaborate the morphological features of the L5/S1 segment to define a so-called "safe zone" for bi- or tricortical screw placement without risking a damage of the iliac vessels. METHODS: A total of one hundred computed tomographies of the pelvis were included in this investigation. On axial and sagittal slices, pedicle morphologies, the prevertebral position of the iliac vessels, the spinal canal and the area with the largest bone density were analyzed. RESULTS: Beginning from the entry point of S1-srews iliac vessels were located at an average angle of 7° convergence, the spinal canal at 38°. Bone density was significantly higher centrally with a mean value of 276 Hounsfield Units compared to the area of the Ala ossis sacri. The largest intraosseous screw length could be achieved at an angle of 25°. The average pedicle width was 20 mm and the pedicle height 13 mm. CONCLUSIONS: A "safe-zone" for bicortical screw placement at S1 with regard to the course of the iliac vessels could be defined between 7° and 38° convergence. Regarding the area offering the largest bone density and the maximal possible screw length, a convergence of 25° is recommended at S1 to reduce the incidence of screw loosening. Screw diameter, as a further influence factor on screw holding, is limited by pedicle height not pedicle width.

[Pseudarthrosis and construct failure after lumbar pedicle subtraction osteotomy : Influence of biomechanics, surgical technique, biology and avoidance strategies]. / Pseudarthrose und Konstruktversagen nach lumbaler Pedikelsubtraktionsosteotomie : Einflüsse von Biomechanik, Operationstechnik, Biologie und Vermeidungsstrategien.

There are numerous factors that can lead to construct failure and pseudarthrosis after corrective pedicle subtraction osteotomy (PSO) in the lumbar spine. Frequently, several factors are of relevance in these problematic cases. This article attempts to explain the surgical, biomechanical and biological aspects that should be understood in order to minimize the risk of pseudarthrosis and construct failure. It addresses technical varieties of the PSO procedure as well as the surgical technique, the choice of rod material and the design of multirod constructs. Biological reasons for pseudarthrosis and preventive strategies are discussed, as well as the possible contribution of low-grade infections to pseudarthrosis. The option of substituting a multilevel ALIF procedure for a PSO is another topic, as is the question of surgical indication and strategy.

Guided Growth: A Novel Treatment for Anterolateral Bowing of the Tibia.

BACKGROUND: Tibial pseudoarthrosis is a source of considerable morbidity in children with neurofibromatosis. Preventing the progression of anterolateral bowing of the tibia (ALBT) to tibial pseudoarthrosis is difficult. The aim of this paper is to report the successful use of guided growth to prevent tibial pseudoarthrosis in a child with neurofibromatosis. METHODS: With local ethical approval, we reviewed the case notes and radiographs of a child with pronounced ALBT who was treated with guided growth to correct the deformity and prevent fracture. RESULTS: At 4-year follow-up guided growth has successfully corrected the deformity and prevented tibial pseudoarthrosis. CONCLUSIONS: This is the first report of the use of guided growth to prevent the progression of ALBT to pseudoarthrosis of the tibia in a child with neurofibromatosis. LEVEL OF EVIDENCE: Level IV.

Disc space preparation in transforaminal lumbar interbody fusion: a comparison of minimally invasive and open approaches.

BACKGROUND: Minimally invasive surgical (MIS) approaches to transforaminal lumbar interbody fusion (TLIF) have been developed as an alternative to the open approach. However, concerns remain regarding the adequacy of disc space preparation that can be achieved through a minimally invasive approach to TLIF. QUESTIONS/PURPOSES: The purpose of this cadaver study is to compare the adequacy of disc space preparation through MIS and open approaches to TLIF. Specifically we sought to compare the two approaches with respect to (1) the time required to perform a discectomy and the number of endplate violations; (2) the percentage of disc removed; and (3) the anatomic location where residual disc would remain after discectomy. METHODS: Forty lumbar levels (ie, L1-2 to L5-S1 in eight fresh cadaver specimens) were randomly assigned to open and MIS groups. Both surgeons were fellowship-trained spine surgeons proficient in the assigned approach used. Time required for discectomy, endplate violations, and percentage of disc removed by volume and mass were recorded for each level. A digital imaging software program (ImageJ; US National Institutes of Health, Bethesda, MD, USA) was used to measure the percent disc removed by area for the total disc and for each quadrant of the endplate. RESULTS: The open approach was associated with a shorter discectomy time (9 versus 12 minutes, p = 0.01) and fewer endplate violations (one versus three, p = 0.04) when compared with an MIS approach, percent disc removed by volume (80% versus 77%, p = 0.41), percent disc removed by mass (77% versus 75%, p = 0.55), and percent total disc removed by area (73% versus 71%, p = 0.63) between the open and MIS approaches, respectively. The posterior contralateral quadrant was associated with the lowest percent of disc removed compared with the other three quadrants in both open and MIS groups (50% and 60%, respectively). CONCLUSIONS: When performed by a surgeon experienced with MIS TLIF, MIS and open approaches are similar in regard to the adequacy of disc space preparation. The least amount of disc by percentage is removed from the posterior contralateral quadrant regardless of the approach; surgeons should pay particular attention to this anatomic location during the discectomy portion of the procedure to minimize the likelihood of pseudarthrosis.

Use of demineralized cortical fibers is associated with reduced risk of pseudarthrosis after pedicle subtraction osteotomy for adult spinal deformity.

PURPOSE: To assess the effect of demineralized cortical fibers (DCF) on postoperative pseudarthrosis requiring revision surgery in patients undergoing pedicle subtraction osteotomy (PSO) for adult spinal deformity (ASD). METHODS: The use of DCF was introduced across all procedures in 2017 and subsequent patients undergoing PSO surgery were prospectively and consecutively registered. Following sample-size estimation, a retrospective cohort was also registered undergoing the same procedure immediately prior to the implementation of DCF. The non-DCF group underwent surgery with ABG. Minimum follow-up was 2 years in both groups. The main outcome was postoperative pseudarthrosis, either CT-verified or verified intraoperatively during revision surgery due to rod breakage and assessed using Kaplan-Meier survival analyses. RESULTS: A total of 48 patients were included in the DCF group and 76 in the non-DCF group. The DCF group had more frequently undergone previous spine surgery (60% vs 36%) and had shorter follow-up (32 ± 2 vs 40 ± 7 months). Pseudarthrosis occurred in 7 (15%) patients in the DCF group and 31 (41%) in the non-DCF group, corresponding to a relative risk increase of 2.6 (95%CI 1.3-2.4, P < 0.01). 1-KM survival analyses, taking time to event into account and thus the difference in follow-up, also showed increased pseudarthrosis in the non-DCF group (log-rank P = 0.022). Similarly, multivariate logistic regression adjusted for age, instrumented levels and sacral fusion was also with significantly increased odds of pseudarthrosis in the non-DCF group (OR: 4.3, 95%CI: 1.7-11.3, P < 0.01). CONCLUSION: We found considerable and significant reductions in pseudarthrosis following PSO surgery with DCF compared to non-DCF. LEVEL OF EVIDENCE: III.

Polymethylmethacrylate-assisted ventral discectomy: rate of pseudarthrosis and clinical outcome with a minimum follow-up of 5 years.

BACKGROUND: Polymethylmethacrylate (PMMA) assisted ventral discectomy has been criticized for high rates of graft migration and pseudarthrosis when compared with various other fusion procedures for the treatment of cervical degenerative disc disease (DDD), therefore rendering it not the preferred choice of treatment today. Recently however spine surgery has been developing towards preservation rather than restriction of motion, indicating that fusion might not be necessary for clinical success. This study presents a long term comparison of clinical and radiological data from patients with pseudarthrosis and solid arthrodesis after PMMA assisted ventral discectomy was performed. METHODS: From 1986 to 2004 416 patients underwent ventral discectomy and PMMA interposition for DDD. The clinical and radiological outcome was assessed for 50 of 127 eligible patients after a mean of 8.1 years. Based on postoperative radiographs the patients were dichotomized in those with a pseudarthrosis (group A) and those with solid arthrodesis (group B). RESULTS: Pseudarthrosis with movement of more than 2 of the operated segment was noted in 17 cases (group A). In 33 cases no movement of the vertebral segment could be detected (group B). The analysis of the clinical data assessed through the neck disability index (NDI), the visual analogue scale (VAS) of neck and arm pain and Odom's criteria did not show any significant differences between the groups.Patients from group B showed a trend to higher adjacent segment degeneration (ASD) than group A (p = 0.06). This correlated with the age of the patients. CONCLUSIONS: PMMA assisted discectomy shows a high rate of pseudarthrosis. But the clinical long-term success does not seem to be negatively affected by this.

Perioperative Corticosteroids Reduce Dysphagia Severity Following Anterior Cervical Spinal Fusion: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: The anterior approach to the cervical spine is commonly used to treat cervical pathology. It is, however, associated with high rates of dysphagia, which may be associated with substantial patient morbidity. Perioperative corticosteroid administration has been advocated to decrease dysphagia rates; its efficacy, however, remains uncertain. We conducted a meta-analysis of randomized trials to determine the efficacy of perioperative corticosteroid administration in reducing postoperative dysphagia as well as any adverse effects, such as pseudarthrosis and infection. METHODS: We conducted a systematic search of electronic databases (MEDLINE, Embase, CENTRAL [Cochrane Central Register of Controlled Trials], ClinicalTrials.gov) to identify randomized controlled trials (RCTs) that evaluated corticosteroids versus any comparator for prevention of postoperative dysphagia after anterior cervical spine procedures. Two independent reviewers used the GRADE (Grades of Recommendation Assessment, Development and Evaluation) criteria to assess eligibility and risk of bias, perform data extraction, and rate the quality of evidence. The primary outcome was severity of postoperative dysphagia. We conducted meta-analyses of dysphagia (both overall and by delivery method), pseudarthrosis, and postoperative infection. RESULTS: After screening of 927 articles, a total of 7 studies were eligible for final inclusion. These included 431 patients, of whom 247 received corticosteroids and 184 received placebo or a control treatment. Moderate-quality evidence demonstrated a significant improvement in postoperative dysphagia rates (odds ratio, 0.35; 95% confidence interval, 0.20 to 0.63; p < 0.001), and this finding was robust to both permutation analyses and sensitivity analyses removing the studies with a high risk of bias. There was no significant difference between intravenous and local steroid administration (p = 0.16). There were no documented infections. There was no significantly increased risk of pseudarthrosis in those receiving steroids compared with placebo or a control treatment (p = 0.13). CONCLUSIONS: This meta-analysis found moderate-quality evidence supporting the use of perioperative corticosteroid administration as an adjunct to anterior cervical spinal procedures. Patients treated with corticosteroids intravenously or locally had significantly decreased severity of dysphagia. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

A Comparison of fixed-hole and slotted-hole dynamic plates for anterior cervical discectomy and fusion.

STUDY DESIGN: A retrospective review of clinical data at 1 institution was performed. OBJECTIVES: To compare the clinical and radiologic outcomes between fixed-hole and slotted-hole dynamic cervical plates. SUMMARY OF BACKGROUND DATA: Anterior cervical plating is commonly used to increase stability and promote spinal fusion. Two techniques, fixed-hole dynamic plating that uses variable angled screws and slotted-hole dynamic plating that permits sliding, are viable options, but there have been no clinical studies comparing their effectiveness. METHODS: Fifty-six patients at 1 institution having anterior cervical discectomy and fusion for degenerative disease over a 5-year period were entered into this study. Surgeries were performed with 1 of the dynamic plates for 1 to 3 levels. For the slotted-hole dynamic plate group, a slotted-hole plate was used (ABC, Aesculap, Tuttlingen, Germany or C-tek, Biomet, Parssipany, NJ) and for the fixed-hole dynamic plated group, a variable angled screw was used (C-tek, Biomet, Parssipany, NJ). Radiographic measurements included were graft subsidence, lordotic angle change from each end plate of fusion construct, and implant translation from end plates after a minimum of 12 months follow-up. Fusion state and clinical outcome using Odom's criteria were also evaluated. RESULTS: Demographics were not different among patient populations. The average age of the patients was 51.0 years (range: 27 to 77 y). Mean follow-up period was 20.6 months (range: 12 to 41 mo). Slotted-hole dynamic plates were used for 29 patients (ABC plate, 17; C-tek plate, 12) and fixed-hole dynamic plates for 27 patients. Clinical outcomes and pseudoarthrosis rates were similar for both types of plates. Radiographic measurements showed a statistically significant increased incidence of graft subsidence and implant translation with the slotted-hole dynamic plates. Loss of lordosis was also greater in the slotted-hole dynamic plated group, although the difference was not statistically significant. CONCLUSIONS: The use of a fixed-hole dynamic plate is more favorable in regards to graft subsidence and implant translation in the follow-up period, although clinical outcome and fusion rates are similar in patients with either the fixed-hole or slotted-hole dynamic plates.

A novel sternal closure technique with implants suitable for complex dehiscences.

A novel sternum stabilization implant system is presented in a complex clinical case with previous pseudarthroses. The authors used the advanced closure system Sternal Talon of KLS Martin group and arranged 1 double and 2 single implants in an atypical fashion to fit the patient's needs. One year later follow up has not revealed any recurrence of pain or pseudarthrotic signs such as crepitation.

A concomitant posterior approach improves fusion rates but not overall reoperation rates in multilevel cervical fusion for spondylosis.

STUDY DESIGN: Retrospective comparative study of 2 approaches to multilevel fusion for cervical spondylosis in consecutive patients at a single institution. OBJECTIVE: To provide justification for a concomitant posterior approach in multilevel cervical fusion for spondylosis by demonstrating decreased pseudarthrosis and reoperation rates. SUMMARY OF BACKGROUND DATA: Among the factors that affect cervical rates is the number of levels, such that increasing the number of levels leads to lower fusion rates. Because of this, modifications have been sought to improve union in multilevel procedures. One option is an antero-posterior (AP) approach or circumferential arthrodesis. METHODS: Seventy-eight consecutive patients who underwent multilevel cervical fusion at a single institution and with minimum 2-year follow-up data were divided into an anterior-only group (anterior: n=55), and an AP group (AP: n=23). Union was assessed by surgical exploration, computerized tomography scan, and flexion-extension radiographs. The groups were compared in terms of pseudarthrosis rates and reoperation rates. RESULTS: Using chi(2) analysis, there was a significant difference in pseudarthrosis rates (anterior 38% vs. AP 0%; P<0.001), and reoperation rate for pseudarthrosis (anterior 22% vs. AP 0%; P=0.01). There were no differences in overall (anterior 36% vs. AP 30%; P=0.62) and early (anterior 15% vs. AP 26%; P=0.13) reoperation rates, but late reoperations were increased in the anterior group (24% vs. AP 4%; P=0.043). CONCLUSIONS: A concomitant posterior fusion significantly reduced the incidence of pseudarthrosis (0% vs. 38%) and pseudarthrosis-related reoperations (0% vs. 22%) compared with traditional anterior-only fusion. However, this did not translate to a difference in overall reoperation rates. The majority of reoperations in the AP group (86%) were performed within 6 months, whereas those in the anterior-only group (65%) were performed later, which was generally when a pseudarthrosis became evident.

Skull bone flap fixation--comparative experimental study to assess the reliability of a new grip-like titanium device (Skull Grip) versus traditional sutures: technical note.

INTRODUCTION: After completing a craniotomy, whenever possible, it is crucial to replace and fix the removed bone flap to the cranium; this in order to keep the brain's protection as well as for cosmetic purposes. Visible skull defects might cause patients psychosocial problems and, most importantly, expose the brain to accidental damage. A fixation device should not only provide optimal attachment of the flap to the skull but also allow fast bony healing to avoid possible pseudoarthrosis and/or osteolytic changes. METHODS: After performing 12 different craniotomies on 4 human cadaver heads the skull flaps were replaced using traditional sutures and a new skull fixation device; for each fixation technique a load-bearing test was performed and the results compared. RESULTS: Bone flaps fixed with the "Skull Grip" showed a strong fixation with optimal plastic deformation when compared to flaps held by sutures that showed less resistance to pressure and could be easily dislocated. CONCLUSION: The "Skull Grip" has shown to be a reliable, effective, and stronger bone flap fixation superior to suturing technique.

Autograft containment in posterolateral spine fusion.

BACKGROUND CONTEXT: Pseudoarthrosis rates in lumbar intertransverse fusion remain high. Compression and displacement of the developing fusion mass by the paraspinal musculature may be a contributory factor. Biocontainment devices have been clinically used in the skull and mandible to guide bone regeneration. The role of a mechanical device in containing graft material in the developing posterolateral lumbar spine fusion is unclear. PURPOSE: To determine the benefits of using a bioabsorbable graft-containment device for lumbar intertransverse fusion, and to evaluate the biocompatibility of this implant by histological analysis of the host tissue reaction. STUDY DESIGN: A rabbit intertransverse spine fusion model was used to evaluate a bioabsorbable graft-containment implant. Study and control groups were compared with regard to the rate, volume, and quality of fusion, as well as host tissue reaction to the graft and implant. METHODS: Fourteen adult male New Zealand White rabbits underwent bilateral posterolateral intertransverse spine arthrodesis at L3-L4. The control group (n=7) received autograft alone, and the study group received autografts placed in open meshed hemicylinders fashioned from LactoSorb sheets (LactoSorb; Biomet Orthopedics Inc., Warsaw, IN). Spines were harvested at 6 weeks and imaged. Radiographs and computed tomography (CT) images were used to calculate the rate, area, and volume of fusion mass. Sections were fixed and stained with hematoxylin-eosin and Mallory trichrome for histological analysis of fusion and host tissue response. The Mann-Whitney nonparametric statistical test was used for the radiographic and CT qualitative assessments. The CT volume quantitation was analyzed using the Student t test. A p value of <.05 was used to assign statistical significance. RESULTS: The fusion rates on radiographs and CT imaging did not show a significant difference (p>.05) between the biocontainment and control groups. The volume of fusion revealed a significant increase with biocontainment (mean+/-standard error; total left+right fusion sides=2.88+/-0.30 cc) compared with controls (2.12+/-0.15 cc) (p<.05). Histology revealed no difference in the maturity or the quality of the fusion mass between the two groups. Inflammatory response around the developing fusion mass and muscle necrosis were slightly increased in the study group. The LactoSorb biocontainment material led to variable inflammatory reaction, with some areas showing little or no response and other showing an inflammatory response with fibrous connective tissue, lymphocyte infiltration, and focal foreign body giant cell reaction. CONCLUSIONS: The incidence of fusion was similar with or without a containment device for onlay bone graft. A significant increase in the volume of the fusion suggests that a biocontainment device does play a role in protecting the developing fusion mass from the mechanical effects of the paraspinal musculature. The clinical use of this device cannot be justified at this time, and further studies will determine whether this increase in fusion volume will translate into a better incidence and volume of fusion in primate and human models.

Preventing Pseudoarthrosis and Proximal Junctional Kyphosis: How to Deal with the Osteoporotic Spine.

The increase in the aging population has led to an overall increase in the number of elderly patients undergoing spinal fusion surgery. This patient population, however, exhibits significant treatment challenges because of poor bone quality. By virtue of exhibiting decreased pullout strength and insertional torque, osteoporotic patients are at a substantial risk of developing vertebral fractures, instrumentation failure, pseudoarthrosis, and proximal junctional failures. It is, therefore, imperative for the treating surgeon to optimize bone health before recommending a spinal fusion surgery. Several preoperative medical therapies (vitamin D, calcium, bisphosphonates, parathyroid hormone, and so forth) exist to optimize bone health.

A Novel 4-Rod Technique Offers Potential to Reduce Rod Breakage and Pseudarthrosis in Pedicle Subtraction Osteotomies for Adult Spinal Deformity Correction.

BACKGROUND: Pedicle subtraction osteotomy (PSO) can be used to treat rigid sagittal plane deformities. Nonunions and rod breakages are known complications of PSO. OBJECTIVE: To assess outcomes of 2 methods of posterior instrumentation for PSO, traditional 2 rods vs a novel 4-rod technique in which 2 additional rods span only the osteotomy level. METHODS: This study was a retrospective, radiographic review of consecutive PSOs performed at 2 centers. The primary difference in technique between the centers was the use of 4 rods including 2 independent rods attached only to the vertebral levels immediately adjacent to the PSO (group 1, n = 29 patients) vs the traditional 2-rod technique (group 2, n = 20 patients). RESULTS: Demographics and preoperative to postoperative radiographic measurements were similar between the study groups, including the PSO wedge resection angle (P = .56). The rod breakage rate was 25% with 2 rods and 0% with 4 rods (P = .008), and the pseudarthrosis rate with 2 rods was 25% and with 4 rods was 3.4% (P = .035). The patient with pseudarthrosis from group 1 had an infection and developed pseudarthrosis only after instrumentation removal. Rates of other complications did not differ significantly between the study groups. CONCLUSION: This study provides a comparison between 2 techniques for rod placement across a PSO and suggests that the described novel 4-rod technique may help to reduce the rates of pseudarthrosis and rod failure. It will be important to confirm these findings in a prospectively designed study with multiple institutions in order to better control for potentially confounding factors.

Radiographic Fusion Grade Does Not Impact Health-Related Quality of Life in the Absence of Instrumentation Failure for Patients Undergoing Posterior Instrumented Fusion for Adult Spinal Deformity.

BACKGROUND: Pseudarthrosis and rod fracture (RF) remain significant concerns after fusion for adult spinal deformity (ASD). Although a radiographic system of fusion grade has been proposed, the correlation between fusion grade and health-related quality of life measures (HRQoL) is not known. METHODS: In a retrospective review of a prospectively collected clinical database, patients that underwent ≥5-level posterior instrumented arthrodesis for ASD were evaluated. Fusion grade was determined on plain films using the Lenke criteria. Patients were grouped as 1) complete fusion (grade I or II at all levels), 2) incomplete fusion (grade 3 or 4 at any level), 3) rod fracture without revision (RF), and 4) rod fracture with revision (RFR). Outcome measures were the Oswestry Disability Index, Medical Outcomes Study 36-Item Short-Form Health Survey Physical and Mental Component Summaries, Scoliosis Research Society-22r total, and Lumbar Stiffness and Disability Index. RESULTS: There were 205 (85%) patients who achieved the minimum 2-year follow-up and were included. Complete fusion was achieved in 115 patients (56.1%), 55% patients (26.8%) had incomplete fusion, and 35% patients (17.1%) had RF. Of the 35 patients with RF, 19 (17.1%; 19/205) underwent revision while 16 (7.8%; 16/205) had RF without revision. HRQoL measures were significantly worse in the RFR group, whereas no significant differences were found between groups 1, 2, and 3. CONCLUSIONS: Radiographic fusion grade after ASD surgery did not significantly impact HRQoL in the absence of RF. RFR was associated with significantly worse clinical outcomes. Fusion grade may be less predictive of clinical outcomes than the occurrence of RF.

Use of osteogenic protein-1 in patients at high risk for spinal pseudarthrosis: a prospective cohort study assessing safety, health-related quality of life, and radiographic fusion. Invited submission from the Joint Section on Disorders of the Spine and Peripheral Nerves, March 2007.

OBJECT: The capability of osteogenic protein (OP)-1 to induce bone formation has led to an increasing interest in its use in fusion surgery. This prospective study examines the safety and efficacy of OP-1 use in patients considered to be at a high risk for developing pseudarthrosis following reconstructive spinal surgery. METHODS: Outcome measures included documentation of adverse events, radiographic evaluation of fusion by an independent musculoskeletal radiologist blinded to treatment, the Oswestry Disability Index (ODI), and the 36-Item Short Form Health Survey (SF-36). The health-related quality of life (HRQOL) assessments (ODI and SF-36) were given at baseline and at 3, 6, 12, 18, and 24 months after the surgical OP-1 implant. RESULTS: The study consisted of 17 male and 13 female patients, with a mean age of 53 years (range 20-77 years). Fourteen patients underwent operations for cervical disease, and 16 for lumbar disease, with a median postoperative follow-up of 24 months (range 13-46 months). There were significant improvements in the physical health (from 28.7 +/- 1.5 to 34.2 +/- 3; p = 0.025) and mental health (from 43.7 +/- 2 to 47.5 +/- 3.1; p = 0.015) summary scores on the SF-36. The mean postoperative ODI score at 6, 9, 12, and 18 months was significantly lower than the baseline ODI score, after taking into consideration a 10-point measurement error (p = 0.0003, p = 0.003, p = 0.004, and p = 0.032, respectively). At 24 months, however, the differences in ODI scores were no longer significant. Of the 30 patients, 24 (80%) were deemed to have a solid fusion. There were no allergic reactions to OP-1 and no symptomatic postoperative hematomas. CONCLUSIONS: Our results suggest that the use of OP-1 is safe and may contribute to high fusion rates, as demonstrated by radiographs, reduced levels of disability, and improved HRQOL in patients considered to be at a high risk for developing a nonunion after spinal reconstructive surgery.

Role of Weekly Teriparatide Administration in Osseous Union Enhancement within Six Months After Posterior or Transforaminal Lumbar Interbody Fusion for Osteoporosis-Associated Lumbar Degenerative Disorders: A Multicenter, Prospective Randomized Study.

BACKGROUND: For elderly patients, posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) is usually performed to treat lumbar degenerative diseases. However, some patients exhibit pseudarthrosis following such procedures. The anabolic agent teriparatide is an approved treatment for promoting bone formation in osteoporotic patients. Our multicenter, prospective randomized study assessed the role of once-weekly teriparatide administration on patient outcomes following interbody fusion. METHODS: Patients were females who were ≥50 years of age, had a bone mineral density (BMD) of <80% of the sex-matched young adult mean and/or previous spinal compression or femoral fractures, and had lumbar degenerative disease. Patients were randomly allocated to receive either weekly teriparatide, administered subcutaneously starting at week 1, for 6 months postoperatively (the teriparatide arm), or no teriparatide (the control arm). Blinded radiographic evaluations were performed using dynamic radiography and computed tomography (CT) and assessed by modified intention-to-treat analysis and per-protocol analysis. Clinical and neurological symptoms were evaluated using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOA-BPEQ) and the Oswestry Disability Index (ODI). RESULTS: Seventy-five patients were randomized to treatment, and 66 patients completed treatment. At 4 months postoperatively, bone fusion in the 2 center CT slices was significantly higher in the teriparatide arm compared with the control arm in the age-adjusted modified intention-to-treat analysis and was significantly higher at 6 months in the per-protocol analysis. Radiographic examinations showed no disc-space narrowing and no intervertebral disc instability. JOA-BPEQ and ODI results were improved postoperatively in both treatment arms. CONCLUSIONS: Weekly administration of teriparatide promoted bone formation at the surgical fusion site and decreased bone resorption, as indicated by bone metabolic marker results, within the early postoperative period. Our findings suggest that combining lumbar interbody fusion and teriparatide treatment may be an effective option for managing lumbar degenerative disease in elderly patients. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Bracing After Surgical Stabilization of Thoracolumbar Fractures: A Systematic Review of Evidence, Indications, and Practices.

BACKGROUND: The role of spinal orthotic braces after surgical stabilization is not clearly defined. We systematically reviewed the published literature to determine patterns of practice, indications, and current evidence for the use of orthotic braces after surgical thoracolumbar fracture stabilization. METHODS: A search was performed for publications including descriptions of postoperative management and outcomes after surgical stabilization of thoracolumbar injuries. Differences between wearing versus not wearing a postoperative brace were examined with regard to loss of deformity correction, pain, return to previous work activity, functional improvement, instrumentation failure rate, pseudoarthrosis, and the percentage of reported complications. RESULTS: This search yielded 76 pertinent studies. Postoperative bracing (POB) was adopted in 62 studies for a median wear time of 13.3 weeks. No significant differences in terms of pain, return to work, Frankel score improvement, or instrumentation failure were found between the POB and non-POB groups. Loss of surgical kyphotic reduction was slightly greater in the POB group (4.79° vs. 3.77°; P < 0.001). The overall complication rate was also higher in the POB group (16.3% vs. 11.9%; P < 0.01). The pseudoarthrosis rate was lower in the braced group (2.4% vs. 6.0%; P < 0.001). CONCLUSIONS: Most surgeons use braces for 3 months after surgical thoracolumbar fracture stabilization. Given the lack of clinical or biomechanical evidence for this, and the additional costs and potential discomfort to patients, further investigation is warranted to determine when and if POB for surgically stabilized thoracolumbar fractures is indicated. Controlled studies should include a careful analysis of pseudoarthrosis and complication rates.

Anterior approach with expandable cage implantation in management of unstable thoracolumbar fractures: Results of a series of 93 patients.

INTRODUCTION: Anterior approach indications in unstable thoracolumbar fractures (UTLF) are debated. The aim of this study was to evaluate the results of anterior fixation and expandable prosthetic vertebral body cage (EPVBC) implantation alone or combined with a posterior approach in the management of UTLF. MATERIALS AND METHODS: Ninety-three patients underwent anterior fixation with implantation of an EPVBC for UTLF from T7 to L5. Long-term kyphosis and vertebral height loss reduction, functional outcomes including visual analogical scale and Oswestry disability index were evaluated. RESULTS: Anterior fixation led to a significant increase of vertebral body height with a gain of 13% after a previous posterior approach, 38% after a single anterior approach and 65% after combined posterior and anterior approaches (P=0.0001). However, anterior fixation did not significantly enhance the vertebral regional kyphosis angle (P=0.08), except in cases of single anterior approach for thoracic fractures (P=0.03). No significant difference was found between early, 3 months and 1 year postoperative vertebral regional kyphosis angle and vertebral body height (P=0.6). Complete fusion was routinely observed at 1 year postoperatively. rhBMP2 implantation in selected cases appears to be a safe and reliable strategy. No infections or surgical revisions were observed after the anterior approach. CONCLUSION: Anterior approach and EPVBC implantation, in UTLF, is a safe and effective procedure, providing long-term vertebral body height and kyphosis correction. Adverse effects of anterior approach remain acceptable. Single anterior fixation is a reliable surgical alternative in thoracic fractures without posterior spine segment injury or spinal cord compression. These results prompted us to extend anterior approach indications in oncology and infectious diseases.

Intraoperative antepulsion of a posterior lumbar interbody fusion cage: three case reports.

Spinal fusion surgery techniques develop together with technologic advancements. New complications are seen as the result of new techniques and these may be very severe due to spinal cord and vascular structures in the lumbar region. The posterior lumbar interbody fusion cage (PLIFC) was shown to enhance spinal fusion and to prevent pseudoarthrosis due to its basic dynamic characteristics. PLIFC migrations are usually observed during the postoperative period, just after the mobilization of the patient and usually toward spinal canal. Migration to the retroperitoneal region is a extremely rare condition in the literature. In this article we discussed three cases of PLIFC antepulsion into the retroperitoneal region during the intraoperative period.