Isolated multiple lumbar transverse process fractures with spinal instability: an uncommon yet serious association.

PURPOSE: Isolated vertebral transverse process fractures of thoracolumbar spine without other vertebral injuries and neurological deficit are generally considered as minor injuries with no concern for associated spinal instability. This report describes a case of multiple lumbar transverse fractures associated with an unexpected yet clinically significant spinal instability. METHODS: A young male presented with right flank pain following being pushed and trapped against the ground by a reversing truck. The neurological examination was normal, and computed tomography (CT) imaging revealed multiple fractures at right transverse processes from L1 to L5, a single left-sided transverse process fracture at L2 and subtle facet joint distraction without other spinal lesions or visceral injuries. The injury was initially deemed as stable requiring symptomatic treatment and in-patient observation. However, discharge upright X-rays taken in a brace showed marked subluxation of L2/L3 and L3/L4 levels. RESULTS: Magnetic resonance imaging revealed significant discoligamentous injuries involving anterior and posterior longitudinal ligaments, annulus fibrosus as well as posterior ligamentous complex. The patient underwent posterior spinal instrumentation and fusion of L1 to L5. CONCLUSIONS: This is the first case description of association of multisegmental lumbar transverse process fractures with notoriously unstable injuries of the major soft-tissue stabilizers of the spine presenting subtle changes on CT images. When a seemingly benign spinal injury is caused by high-energy trauma, careful scrutiny for associated instability is needed. In this case, the standing in-brace X-ray was able to avoid a misdiagnosis and potentially unfavourable outcome.

Surgical Site Infection as a Risk Factor for Long-Term Instrumentation Failure in Patients with Spinal Deformity: A Retrospective Cohort Study.

BACKGROUND: Surgical site infection (SSI) remains a complication of spine deformity surgery. Although fusion/instrumentation failure in the setting of SSI has been reported, few studies have investigated the relationship between these entities. We examine the relationship between early SSI and fusion/instrumentation failure after instrumented fusion in patients with thoracolumbar scoliosis. METHODS: A retrospective review of a prospectively maintained case series for patients undergoing spine surgery between January 1, 2006, and October 3, 2017. Inclusion criteria included age ≥18 years and surgery performed for correction of thoracolumbar scoliosis. Data collected included various demographic, clinical, and operative variables. RESULTS: 532 patients met inclusion criteria, with 20 (4%) experiencing SSI. Diabetes mellitus was the only demographic risk factor for increased SSI (P = 0.026). Number of fused levels, blood volume loss, and operative time were similar between groups. Fusion/instrumentation failure occurred in 68 (13%) patients, 10 of whom (15%) had SSI, whereas of the 464 patients with no fusion/instrumentation failure, only 10 (2%) had SSI (P < 0.001). Of the 20 patients with SSI, 10 (50%) had fusion/instrumentation failure, whereas in the 512 patients with no infection, only 58 (11%) had fusion/instrumentation failure (P < 0.001). Patients with infection also experienced significantly shorter time to fusion/instrumentation failure (P = 0.025), higher need for revision surgery (P < 0.001), and shorter time to revision surgery (P = 0.012). CONCLUSIONS: Early SSI significantly increases the risk of fusion/instrumentation failure in patients with thoracolumbar scoliotic deformity, and it significantly shortens the time to failure. Patients with early SSI have a significantly higher likelihood of requiring revision surgery and after a significantly shorter time interval.

Fibromyalgia as a Predictor of Increased Postoperative Complications, Readmission Rates, and Hospital Costs in Patients Undergoing Posterior Lumbar Spine Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study was to identify whether a concomitant diagnosis of fibromyalgia (FM) influences postoperative complications, readmission rates or cost following primary 1 to 2 level lumbar fusions in an elective setting. SUMMARY OF BACKGROUND DATA: Patients with FM often are limited by chronic lower back pain, many of whom will seek operative treatment. No previous study has evaluated whether patients with a concomitant diagnosis of FM have more complications following spine surgery. METHODS: Medicare data (2005-2014) from a national database was queried for patients who underwent primary 1 to 2 level posterolateral lumbar spine fusion for degenerative lumbar pathology. Thirty- and 90-day postoperative complication rates, readmission rates, and treatment costs were queried. To reduce confounding, FM patients were matched with a control cohort of non-FM patients using patient demographics, treatment modality, and comorbid conditions, and then analyzed by multivariable logistic regression. RESULTS: Within the first 30-day postoperative, acute post hemorrhagic anemia (odds ratio [OR]: 2.58; P < 0.001) and readmission rates were significantly higher in FM patients compared to controls. There was no significant difference in wound related complications within first 30-days (0.19% vs. 0.23%; P = 0.520) or with length of stay (3.60 vs. 3.53 days; P = 0.08). Within 90-day postoperative, FM patients had higher rates of pneumonia (OR: 3.73; P < 0.001) and incurred 5.31% more in hospital charges reimbursed compared to the control cohort. CONCLUSION: Primary 1 to 2 level lumbar fusions performed on FM patients have higher rates of postoperative anemia, pneumonia, cost of care, and readmission compared to match controls. FM patients and surgeons should be aware of these increased risks in an effort to control hospital costs and potential complications. LEVEL OF EVIDENCE: 3.

Analysis of Internet Review Site Comments for Spine Surgeons: How Office Staff, Physician Likeability, and Patient Outcome Are Associated With Online Evaluations.

STUDY DESIGN: Observational study. OBJECTIVE: To evaluate how online patient comments will affect website ratings for spine surgeons. SUMMARY OF BACKGROUND DATA: With the ever-growing utilization of physician review websites, healthcare consumers are assuming more control over whom they choose for care. We evaluated patient feedback and satisfaction scores of spine surgeons using comments from three leading physician rating websites: Healthgrades.com, Vitals.com, Google.com. This is the largest review of online comments and the largest review of spine surgeon comments. METHODS: From the North American Spine Society (NASS) membership directory, 210 spine surgeons practicing in Florida (133 orthopedic trained; 77 neurosurgery trained) with online comments available for review were identified, yielding 4701 patient comments. These were categorized according to subject: (1) surgeon competence, (2) surgeon likeability/character, (3) office staff, ease of scheduling, office environment. Type 1 and 2 comments were surgeon-dependent factors whereas type 3 comments were surgeon-independent factors. Patient comments also reported a score (1-5), 5 being the most favorable and 1 being the least favorable. RESULTS: There were 1214 (25.8%) comments from Healthgrades, 2839 (60.4%) from Vitals, and 648 (13.8%) from Google. 89.9% (4225) of comments pertained to surgeon outcomes and likeability (comment type 1 and 2), compared with 10.1% (476) surgeon-independent comments (comment type 3) (P < 0.0001). There was a significantly higher number of favorable ratings associated with surgeon-dependent comments (types 1 and 2) compared with surgeon-independent comments (type 3). Surgeon-independent comments were associated with significantly lower scores compared with comments regarding surgeon-dependent factors on all review sites. CONCLUSION: Spine surgeons are more likely to receive favorable reviews for factors pertaining to outcomes, likeability/character, and negative reviews based on ancillary staff interactions, billing, and office environment. Surgeons should continue to take an active role in modifying factors patients perceive as negative, even if not directly related to the physician. LEVEL OF EVIDENCE: 3.

How social media, training, and demographics influence online reviews across three leading review websites for spine surgeons.

BACKGROUND CONTEXT: The future of health care is consumer driven with a focus on outcome metrics and patient feedback. Physician review websites have grown in popularity and are guiding patients to certain health-care providers, for better or worse. No prior study has specifically evaluated Internet reviews of spine surgeons, determined if social media (SM) correlates with patient reviews, or evaluated Google as a physician review website. PURPOSE: This study aimed to evaluate patient satisfaction scores for spine surgeons in Florida using leading physician ratings websites. STUDY DESIGN: A retrospective study was carried out. SAMPLE POPULATION: The sample comprised spine surgeons with a review on Healthgrades.com (HG), Vitals.com (V), or Google.com (G) online rating websites as of August 17, 2017. OUTCOME MEASURES: Number of ratings, number of comments, overall rating, patient-reported wait times, physician website presence, and physician SM presence were the outcome measures. METHODS: Using the directory of registered North American Spine Society physicians, we identified all spine surgeons practicing in Florida (137 orthopedic trained; 78 neurosurgery trained). Surgeon demographics and ratings data were collected from three physician rating websites (HG, V, G) from July 19, 2017 to August 17, 2017. Using only the first 10 search results from Google.com we then identified if the surgeon had accounts on Facebook (FB), Twitter (TW), or Instagram (IG). RESULTS: Nearly every surgeon in this cohort had either an institutional or personal website (98.1%), and 38.6% had at least one SM outlet of our three reviewed. Both personal and institutional website presence significantly correlated with higher G scores. Spine surgeons with a searchable account on FB, TW, or IG made up 35.4%, 10.2%, and 0.5% of the cohort, respectively. Surgeons with an SM presence had a significantly higher number of ratings and comments on HG, V, and G, but not overall scores. In multivariable analysis, only V showed a significant inverse correlation between overall score and age, private institution, and orthopedic surgery training. Wait times >30 minutes were significantly associated with worse overall scores across all three review sites. Overall ratings between HG, V, and G all had significantly positive correlations on Pearson correlation analysis. CONCLUSION: Social media presence correlates with patient communication in the form of number of ratings and comments, yet does not impact overall scores, suggesting social media may influence patient feedback. Longer wait times are indicative of lower scores across all three platforms. Overall ratings from all three websites correlate significantly with each other, indicating agreement between physician ratings across different platforms. Understanding the factors that optimize a patient's overall experience with a physician is an important and emerging outcome measure for the future of patient-centered health care.

Percutaneous and open iliac screw safety and accuracy using a tactile technique with adjunctive anteroposterior fluoroscopy.

BACKGROUND CONTEXT: All currently described percutaneous iliac screw placement methods are entirely dependent on fluoroscopy. PURPOSE: The purpose of this study was to determine the safety and the accuracy of percutaneous and open iliac screw placement using a primarily tactile technique with adjunctive anteroposterior (AP) fluoroscopy. STUDY DESIGN/CONTEXT: All patients who underwent open and percutaneous iliac screw placement over a 5-year period were identified. Charts were reviewed to assess for any instances of neurologic or vascular injury associated with iliac screw placement. Screw accuracy was judged with postoperative computed tomography (CT) scans. PATIENT SAMPLE: A total of 133 patients were identified who underwent open or percutaneous iliac screw placement. Computed tomography scans were available for 57 patients, and all of these patients were included in the study, with a total of 115 iliac screws. OUTCOME MEASURES: Radiographic measurements were performed, consisting of the distance of the iliac screw to the sciatic notch on postoperative radiographs and CT scans. Computed tomography scans were used to determine iliac screw accuracy. METHODS: Charts were reviewed to assess for any neurologic or vascular injuries related to screw placement. The distance of the iliac screw to the sciatic notch was measured and compared on AP radiography and CT scans. Computed tomography scans were assessed for any screw violation of the iliac cortex or the sciatic notch. The accuracy of open iliac screw placement was compared with minimally invasive percutaneous placement. RESULTS: There were no neurologic or vascular injuries related to screw placement in the 133 patients. Computed tomography scans were available for 115 iliac screws, with 3 cortical breaches, all by less than 2 mm. All 112 other screws were accurately intraosseous. There was a strong correlation between the iliac screw to the sciatic notch distance when measured by CT scan compared with AP radiography (r=0.9), thus validating the accuracy of AP fluoroscopy in guiding iliac screw placement with respect to the sciatic notch. Iliac screw accuracy was equal with the open and percutaneous insertion techniques. CONCLUSIONS: The described surgical technique represents a safe and reliable surgical option for iliac screw placement. Intraoperative AP fluoroscopy accurately reflects the distance of the iliac screw to the sciatic notch. Percutaneous iliac screws placed with this technique are as accurate as open iliac screws.

Changes in Cervical Alignment after Multilevel Schwab Grade II Thoracolumbar Osteotomies for Adult Spinal Deformity.

STUDY DESIGN: A retrospective cohort. OBJECTIVE: The aim of this study was to describe changes in cervical alignment (CA) and cervical deformity (CD) after multilevel Schwab Grade II Osteotomies for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: Reciprocal cervical and global changes after ASD surgery have not been previously described in the setting of multilevel osteotomy. METHODS: Patients with long-segment (> five levels) fusion and osteotomy for ASD were radiographically evaluated. Pre- and postoperative cervical parameters evaluated included cervical lordosis (CL), C2-C7 sagittal vertical axis (C2-C7 SVA), and the T1 slope (T1S) minus the CL (T1S-CL). CD was defined as C2-C7 SVA >4 cm, CL < 0°, or T1S-CL ≥15°. RESULTS: Eighty-five patients (mean age 64 ±â€Š11.1) were identified. Preoperative lumbar lordosis (LL) was 28.7°â€Š±â€Š13.8°, thoracic kyphosis (TK) was 28.2°â€Š±â€Š17.0°, C7 plumbline (C7 SVA) was 7.54 ±â€Š6.7 cm, pelvic tilt (PT) was 30.0°â€Š±â€Š8.96°, lumbopelvic mismatch was 32°â€Š±â€Š17.1°, and the T1 pelvic angle (TPA) was 26.8°â€Š±â€Š12.9°. The C7 SVA and TPA corrected to 3.90 cm (P < 0.0001) and 17.5°, respectively (P < 0.0001). CD increased from 41 (48%) to 47 (55%) patients. The mean CL changed from 16.5° to 11.9° (P < 0.013), C2 SVA from 10.1 to 6.37 cm (P < 0.0001), T1S-CL from 10.2° to 14.3° (P = 0.021), and TK from 28° to 39° (P < 0.0001). A correlation was observed between T1S and CL (ρ = 0.435, P < 0.0001) and C2-C7 SVA (ρ = 0.624, P < 0.0001). T1S was the only independent predictor of both the postoperative C2-C7 SVA and CL.In this study, the presence of any single preoperative CD criterion was noted to be a risk for persistent global deformity on postoperative radiograph [odds ratio (OR) = 2.5] and the development of PJK (OR = 2.1). The T1-CL < 15° may indicate an even greater risk for persistent global deformity (OR = 3.5). CONCLUSION: Thoracolumbar fusion with multilevel Schwab Grade II Osteotomies was associated with a decreased CL and reciprocal increases in TK and T1S-CL. LEVEL OF EVIDENCE: 3.

Multilevel Schwab grade II osteotomies for sagittal plane correction in the management of adult spinal deformity.

BACKGROUND CONTEXT: Prior reports have compared posterior column osteotomies with pedicle subtraction osteotomies in terms of utility for correcting fixed sagittal imbalance in adolescent patients with deformity. No prior reports have described the use of multilevel Smith-Petersen Osteotomies (SPOs) alone for surgical correction in the adult spinal deformity (ASD) population. PURPOSE: The study aimed to determine the utility of multilevel SPOs in the management of global sagittal imbalance in ASD patients. STUDY DESIGN/SETTING: This is a retrospective observational study at a single academic center. PATIENT SAMPLE: The sample included 85 ASD patients. OUTCOME MEASURES: This is a radiographic outcomes cohort study. METHODS: The radiographs of 85 ASD patients were retrospectively evaluated before and after long-segment (>5 spinal levels) fusion and multilevel SPO (≥3 levels) for sagittal imbalance correction. The number of osteotomies, correction in regional lumbar lordosis (LL), and correction per osteotomy was evaluated. Independent predictors of correction per SPO were evaluated with a hierarchical linear regression analysis. RESULTS: Eighty-five patients (mean age: 67.5±11 years) were identified with ASD (372 SPOs). The mean preoperative sagittal vertical axis (SVA) and T1 pelvic angle (TPA) were 8.16±6.75 cm and 25°±13.23°, respectively. The mean postoperative central sacral vertical line (CSVL) and SVA were 0.67±0.70 cm and 1.29±5.41 cm, respectively. The mean improvement in SVA was 6.29 cm achieved with a correction of approximately 5.05° per SPO. The mean LL restoration was 20.3°±13.9°, and 33(39%) patients achieved a final pelvic incidence minus lumbar lordosis (PI-LL) ≤10°. Fifty-four (64%) achieved a postoperative PI-LL ≤15°, 75 (88%) with a PI-LL ≤20°, and 85 (100%) achieved a PI-LL ≤25°. Correction per SPO was similar regardless of prior fusion (4.87° vs. 5.72° for revisions, p=.192). In a subgroup analysis of SVA greater than 10 cm, there was no significant difference in the final LL, thoracic kyphosis, PI-LL, SVA, CSVL, and TPA, as compared with SVA <10 cm. The LL was the only independent predictor of osteotomy correction per level (LL: ß coefficient=-0.108, confidence interval: -0.141 to 0.071, p<.0001). CONCLUSIONS: Multilevel SPOs are feasible for restoration of LL as well as sagittal and coronal alignment in the ASD population with or without prior instrumented fusion.

Prophylactic vertebral cement augmentation at the uppermost instrumented vertebra and rostral adjacent vertebra for the prevention of proximal junctional kyphosis and failure following long-segment fusion for adult spinal deformity.

BACKGROUND CONTEXT: Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are common problems after long-segment (>5 levels) thoracolumbar instrumented fusions in the treatment of adult spinal deformity (ASD). No specific surgical strategy has definitively been shown to lower the risk of PJK as the result of a multifactorial etiology. PURPOSE: The study aimed to assess the incidence of PJK and PJF in patients treated with prophylactic polymethylmethacrylate (PMMA) cement augmentation at the uppermost instrumented vertebrae (UIV) and rostral adjacent vertebrae (UIV+1). STUDY DESIGN/SETTING: This is a retrospective cohort-matched surgical case series at an academic institutional setting. PATIENT SAMPLE: Eighty-five adult patients over a 16-year enrollment period were identified with long-segment (>5 levels) posterior thoracolumbar instrumented fusions for ASD. OUTCOME MEASURES: Primary outcomes measures were PJK magnitude and PJF formation. Secondary outcomes measures were spinopelvic parameters, as well as global and regional sagittal alignment. METHODS: The impact of adjunctive PMMA use in long-segment (≥5 levels) fusion for ASD was assessed in adult patients aged 18 and older. Patients were included with at least one of the following: lumbar scoliosis >20°, pelvic tilt >25°, sagittal vertical axis >5 cm, central sacral vertical line >2 cm, and thoracic kyphosis >60°. The frequency of PJF and the magnitude of PJK were measured radiographically preoperatively, postoperatively, and at maximum follow-up in controls (Group A) and PMMA at the UIV and UIV+1 (Group B). RESULTS: Eighty-five patients (64±11.1 years) with ASD were identified: 47 control patients (58±10.6) and 38 patients (71±6.8) treated with PMMA at the UIV and UIV+1. The mean follow-up was 27.9 and 24.2 months in Groups A and B, respectively (p=.10). Preoperative radiographic parameters were not significantly different, except the pelvic tilt which was greater in Group A (26.6° vs. 31.4°, p=.03). Postoperatively, the lumbopelvic mismatch was greater in Group B (14.6° vs. 7.9°, p=.037), whereas the magnitude of PJK was greater in controls (9.36° vs. 5.65°, p=.023). The incidence of PJK was 36% (n=17) and 23.7% (n=9) in Groups A and B, respectively (p=.020). The odds ratio of PJK with vertebroplasty was 0.548 (95% confidence interval=0.211 to 1.424). Proximal junctional kyphosis was observed in 6 (12.8%) controls only (p=.031). The UIV+1 angle, a measure of PJK, was significantly greater in controls (10.0° vs. 6.8°, p=.02). No difference in blood loss was observed. No complications were attributed to PMMA use. CONCLUSIONS: The use of prophylactic vertebral cement augmentation at the UIV and rostral adjacent vertebral segment at the time of deformity correction appears to be preventative in the development of proximal junctional kyphosis and failure.

Is a Persistent Vacuum Phenomenon a Sign of Pseudarthrosis After Posterolateral Spinal Fusion?

The purpose of this study is to evaluate whether the vacuum phenomenon (VP) resolves after posterolateral lumbar fusion, and whether persistence of VP is indicative of failed fusion. We retrospectively reviewed patients with degenerative lumbar spinal stenosis with instability with a positive VP on preoperative computed tomography (CT) who underwent posterolateral lumbar spinal fusion. Lumbar CT and radiographs were evaluated for the presence of VP and fusion at each level. Thirty-six positive VP levels were identified on the preoperative lumbar CT at the levels in the fusion in 18 patients. The mean age at surgery was 67.6 ± 9.4 years and mean follow-up was 1.6 ± 0.86 years. Fusion was seen at 32 levels (88.9%). Of the 15 levels where VP persisted, evidence of fusion was seen in 13 levels and pseudarthrosis was seen at 2. Of the 21 levels where VP disappeared, fusion was seen at 19 levels and pseudarthrosis was seen at 2 .There was no significant difference between the 2 groups (P > .05). We did not find an association between persistence of VP and pseudarthrosis. Persistence of VP after spinal fusion may not be an indicator of pseudarthrosis, and should not be misinterpreted as an indication for additional surgery.

Focal Correction of Severe Fixed Kyphosis with Single Level Posterior Ponte Osteotomy and Interbody Fusion.

OBJECTIVE: To report the successful correction of a severe, fixed kyphotic deformity utilizing a combination posterior lumbar interbody fusion (PLIF) and Ponte osteotomy at the site of acute kyphosis. SUMMARY OF BACKGROUND DATA: There have been no reports on the experience and surgical strategy of combined one-level focal PLIF and Ponte osteotomy for fixed severe kyphotic deformity. Typically, these corrections would need a pedicle subtraction osteotomy or a vertebrectomy. METHODS: A 24-year-old man presented with progressive back pain and a fixed severe thoracolumbar kyphosis centered at the L2-L3 disc space seven years after removal of instrumentation for intractable infection following correction of Scheuermann's Kyphosis. The patient also demonstrated pseudoarthrosis of the posterior thoracolumbar fusion bed. The original operative plan was to perform a vertebral column resection (VCR) of L2 to correct his severe kyphosis.  During preparation for the VCR, the patient's deformity corrected completely after insertion of blunt distraction paddles for the interbody fusion after the Ponte osteotomy at L2-L3. A VCR was avoided, and the construct was able to be completed with simple rod insertion and posterolateral fusion. RESULTS: The described technique achieved 69 degrees of correction at the L2-L3 disc space without any remodeling of the surrounding vertebrae. The C7 plumb line was normalized, and the patient was able to stand upright with horizontal gaze and without pre-existing discomfort. At the six-month follow-up, the patient reported a significant improvement in pain and was able to resume normal activities.

Minimally Invasive Versus Open Lumbar Fusion: A Comparison of Blood Loss, Surgical Complications, and Hospital Course.

BACKGROUND: Perioperative blood loss is a frequent concern in spine surgery and often necessitates the use of allogeneic transfusion. Minimally invasive technique (MIS) is an option that minimizes surgical trauma and therefore intra-operative bleeding. The purpose of this study is to evaluate the blood loss, surgical complications, and duration of inpatient hospitalization in patients undergoing open posterolateral lumbar fusion (PLF), open posterior lumbar interbody fusion (PLIF) with PLF, or MIS transforaminal lumbar interbody fusion (MIS TLIF). METHODS: Operative reports and perioperative data of patients undergoing single-level, primary open PLF (n=41), open PLIF/PLF (n=42), and MIS TLIF (n=71) were retrospectively evaluated. Patient demographics, operative blood loss, use of transfusion products, complications, and length of stay were tabulated. Patient data was controlled for age, BMI, and gender for statistical analysis. RESULTS: Patients undergoing open PLF and open PLIF/PLF respectively experienced a significantly higher blood loss (p<0.001), higher volume of blood transfusion (p<0.001), higher volume of cell saver transfusion (p<0.001), and more surgical complications (dural injury, wound infections, screw malposition) (p=0.02) than those undergoing MIS TLIF. There was no statistically significant difference in duration of hospital stay (p=0.11). CONCLUSIONS: MIS TLIF provides interbody fusion with less intraoperative blood loss and subsequently a lower transfusion rate compared to open techniques, but this did not influence length of hospital stay. MIS TLIF is at least as safe as open techniques with respect to dural tear, wound infection, and screw placement. LEVEL OF EVIDENCE: Level III, Therapeutic.

Biomechanical comparison of lumbosacral fixation techniques in a calf spine model.

STUDY DESIGN: biomechanical testing of the strength and stability of lumbosacral fixation constructs. OBJECTIVES: The purpose of this study was to quantify and compare the biomechanical properties of five different lumbosacral fixation constructs and determine the benefit of adding supplementary fixation to S1 screws. SUMMARY OF BACKGROUND DATA: Extension of long fusions to the sacrum remains a difficult clinical challenge. Only a limited number of biomechanical studies have evaluated the different fixation methods available, and none has included both nondestructive and load to failure testing of these fixation methods. METHODS: Six fresh-frozen calf spines were prepared and tested for each construct. The five constructs tested included the following: S1 screws alone, S1 screws and S2 proximally directed screws, S1 screws and S2 distally directed screws, S1 screws and intrasacral rods, and S1 screws and iliac screws. Nondestructive, multidirectional flexibility analyses included four loading methods followed by a destructive flexural load to failure. Lumbosacral peak range of motion (millimeters or degrees) and ultimate failure load (Nm) of the five reconstruction techniques were statistically compared using a one-way analysis of variance combined with a Student-Newman-Keuls post hoc test. RESULTS: S1 screw strain tested in flexion-extension was significantly reduced by the addition of any second point of distal fixation. There was no significant difference between any of the different sacral fixation constructs (P > 0.05). In axial compression, only the addition of iliac screws significantly reduced S1 screw strain. In destructive testing under flexion loading, only iliac screws statistically increased the load at failure (P = 0.005). CONCLUSION: This study demonstrates the effectiveness of adding a second fixation point distal to the S1 screws in reducing S1 screw strain. Iliac fixation is more effective than secondary sacral fixation points but may not be necessary in all clinical situations. Only iliac fixation effectively increased the load to failure under catastrophic loading conditions. Supplementary sacral fixation failed to significantly protect against catastrophic failure. These findings support the clinical observation that iliac fixation is least likely to fail in high-risk, long fusions. Whether testing range of motion, screw strain, or load to failure, no benefit could be demonstrated for intrasacral rod placement when compared with other supplementary sacral fixation techniques. Intrasacral rod placement was equal to a second sacral screw in reducing S1 screw strain during flexion-extension loading. It was not as effective as iliac fixation in reducing screw strain or preventing catastrophic failure. When choosing fixation methods in long fusions to the sacrum, this study supports the use of iliac fixation as the method least likely to loosen or pull out. A second point of sacral fixation also offers biomechanical advantages when compared with S1 fixation alone and may be an appropriate choice in less "high risk" fusions to the sacrum.