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Background: Controversy exists regarding the ability of posterior (transforaminal) lumbar interbody fusion (PLIF/TLIF) to achieve lordosis. We hypothesized that an interbody device (IBD) designed for positioning in the anterior disc space produces greater lordosis than IBDs designed for straight-in positioning. The purpose of this study is to determine if using either an anterior-position or straight-in position IBD design were associated with successful achievement of postoperative lordosis. Methods: A consecutive series of patients undergoing a undergoing a single-level, posterior open midline (transforaminal) lumbar interbody fusion procedure for degenerative spine conditions during a time period when the two types of interbody devices were being used at surgeon discretion were identified from a multi-surgeon academic training center. Patient demographics and radiographic measures including surgical level lordosis (SLL), anterior disc height, middle disc height, posterior disc height, IBD height, and IBD insertion depth were measured on preop, immediate postop, and one-year postop standing radiographs using PACS. Group comparison and regression analysis were performed using SPSS. Results: Sixty-one patients were included (n=37 anterior, n=34 straight-in). Mean age was 59.8±8.7 years, 32 (52%) were female. There was no difference between IBD type (anterior vs. straight-in) for mean Pre-op SLL (19±7° vs. 20±6°, p=0.7), Post-op SLL (21±5° vs 21±6°, p=0.5), or Change in SLL (2±4° vs. 1±5°, p=0.2). Regression analysis showed that Pre-op SLL was the only variable associated with Change in SLL (Beta = negative 0.48, p=0.000). While the mean Change in SLL could be considered clinically insignificant, there was wide variability: from a loss of 9° to a gain of 13°. Gain of lordosis >5° only occurred when Pre-op SLL was 5° only occurred when Pre-op SLL was >21°. Conclusions: While group averages showed an insignificant change in segmental lordosis following a posterior (transforaminal) interbody fusion regardless of interbody device type, pre-operative lordosis was correlated with a clinically significant change in segmental lordosis. Preoperative hypolordotic discs were more likely to gain significant lordosis, while preoperative hyperlordotic discs were more likely to lose significant lordosis. Surgeon awareness of this tendency can help guide surgical planning and technique.

Background: During the preoperative evaluation of a patient being considered for spinal surgery, Dual-energy x-ray absorptiometry (DEXA) has been traditionally used to diagnose poor bone mineral density (BMD) as a risk factor. As ordering a DEXA can add cost and delay diagnosis, spine surgeons have more recently began to use Hounsfield Units (HU) measured on computed tomography scans (CT) as a measure of BMD. The aim of our study was to evaluate associations between DEXA and HU on lumbar spine CT scans. Methods: Forty-two patients (32 female, 10 male, mean age = 67.7 years) with DEXA and lumbar spine CT scans performed within one year of each other were identified. DEXA T-scores were collected from the hip, forearm and L1-L4. HU was determined using the maximum region of interest within the cancellous area in the mid-vertebral body from L1-L4 in the sagittal and axial planes. Results: Using the lowest T-score, 8 (19 %) cases were osteoporotic and 25 (60 %) were osteopenic. Statistically significant differences in HU were seen in osteoporotic cases (Axial HU = 59.2, Sagittal HU = 61.1, p = 0.006) compared to osteopenic (Axial HU = 119.8, Sagittal HU = 122.9) and normal cases (Axial HU = 141.2, Sagittal HU = 142.3). There were moderate associations between the spine T-scores and CT HUs (Axial HU:r2 = 0.50, Sagittal HU:r2 = 0.49, p

Background: Patients with a pseudarthrosis after anterior cervical discectomy and fusion (ACDF) may have concurrent adjacent segment disease (ASD). Although prior studies have shown posterior cervical decompression and fusion (PCDF) is effective in repairing pseudarthrosis, improvement in patient reported outcomes (PROs) has been marginal. The aim of this study is to evaluate the effectiveness of PCDF in achieving symptom relief in patients with pseudarthrosis after ACDF and whether that is altered by the additional treatment of ASD. Methods: Thirty-two patients with pseudarthrosis were compared with 31 patients with pseudarthrosis and concurrent ASD after ACDF who underwent revision PCDF with a minimum 1-year follow-up. Primary outcomes measures included the neck disability index (NDI), and numerical rating scale (NRS) scores for neck and arm pain. Secondary measures included estimated blood loss (EBL), operating room (OR) time, and length of stay. Results: Demographics between cohorts were similar, however there was a significantly higher mean body mass index (BMI) in the group with concurrent ASD (32.23 vs. 27.76, p=.007). Patients with concurrent ASD had more levels fused during PCDF (3.7 vs. 1.9, p

Background: Novel methods of bone density assessment using computed tomography (CT) and magnetic resonance imaging (MRI) have been increasingly reported in the spine surgery literature. Correlations between these newer measurements and traditional Dual-Energy X-ray Absorptiometry (DEXA) is not well known. The purpose of this study is to perform an updated systematic review of correlations between bone mineral density (BMD) from CT or MRI and DEXA. Methods: Articles published between 2011 and 2021 that reported correlations between the CT-HU or MRI measurements to DEXA t-scores or BMD of lumbar spine or hip were included in this systematic review. Results: A total of 25 studies (15 CT, 10 MRI) met the inclusion criteria with a total number of 2,745 patients. The pooled correlation coefficient of spine CT-HU versus spine DEXA, spine CT-HU versus hip DEXA and spine CT-HU versus lowest t-score were 0.60, 0.50 and 0.60 respectively. Regarding spine DEXA parameters, the pooled r2 for spine CT-HU versus spine t-score was 0.684 and spine CT-HU versus spine BMD was 0.598. Furthermore, in patients undergoing spine surgery in four studies, the pooled correlation between spine CT and spine DEXA was (r2: 0.64). In MRI studies, the pooled r2 of spine MRI versus spine DEXA and spine MRI versus hip DEXA were -0.41 and -0.44 respectively. Conclusions: CT-HU has stronger correlations with DEXA than MRI measurements. Lumbar CT-HU has the highest pooled correlation (r2 = 0.6) with both spine DEXA and lowest skeletal t-score followed by lumbar CT-HU with hip DEXA (r2 = 0.5) and lumbar MRI with hip (r2 = 0.44) and spine (r2 = 0.41) DEXA. Both imaging modalities achieved only a moderate correlation with DEXA. Few studies in both modalities have investigated the correlation in spine surgery populations and the available data shows that the correlations are worse in the degenerative spine population. A careful interruption of CT HU and MRI measurement when evaluation of BMD as they only moderately correlated with DEXA scores. At this time, it is unclear which modality is a better predictor of mechanical complications and clinical outcomes in spine surgery patients.

Background: Temperature elevation, a classic marker of infection and local temperature elevation, might be a useful predictor of early infection. However temperature measurement around the spine is not readily accessible. The purpose of this study was to explore whether a temperature sensing implant might reproducibly detect local temperature change associated with peri-implant wound infection, in a rabbit model. Methods: Twelve adult rabbits were implanted with a spinal screw-rod construct. Temperature probes were placed at the implantation site as well as at a separate scapular site away from the surgical site to serve as control. Animals were inoculated with S. aureus: group 1 (saline control), group 2 (low dose 1 × 102 CFU/site), group 3 (medium dose 1 × 104 CFU/site), and group 4 (high dose 1 × 106 CFU/site) and monitored for 7 days prior to euthanasia. Results: The scapular control temperature and implant site temperature in the non-infected animals remained similar throughout the study period. Both the scapular control and implant site temperatures were elevated in the infected animals compared to the non-infected animals. There was a statistically significant difference in the scapular control temperature and implant site temperature in all infected animals but not in the non-infected animals. Difference in temperature elevation between implant site and control scapular site were greatest for the animals with worst clinical appearance during the post-mortem evaluation. Conclusions: This rabbit model demonstrates that local temperature measured in proximity to a spinal implant is elevated in the presence of infection with greater elevations associated with worse infections. Availability of an implantable temperature sensor may yield valuable information for the assessment and treatment of suspected spinal wound infection in the clinical setting.

Background: The Romberg test is used to identify balance issues in patients with Cervical Spondylotic Myelopathy (CSM), but has subjective interpretation. The purpose of this study is to evaluate force plate pressure readings during a Romberg test to quantify postural control. Methods: Quantitative Romberg force plate readings with eyes open and closed in patients with CSM were obtained and changes in balance measurements were compared to a normal population (N = 28, mean age 39 ± 7 years). Results: We identified 30 CSM patients with a mean age of 58 ± 10 years. Majority of patients presented with pain (90%) and neurologic symptoms (83%). Cord compression on imaging was identified in 90%. Mean eyes closed Romberg measurements were larger compared to eyes open measurements in CSM patients (p

Background: The utilization of the S2 Alar-Iliac (S2AI) screw provides an optimal method of spinopelvic fixation. The free-hand placement of these screws obviates the use of intra-operative fluoroscopy and relies heavily on sacropelvic anatomy; variations of this anatomy could alter the ideal screw trajectory. The S2AI corridor is near several neurovascular structures, thus an accurate trajectory is critical. The reported angles of trajectory vary within the literature and a paucity of data exists on how patient morphometry influences ideal screw trajectory. We sought to examine the relationship between ideal screw trajectory and pelvic parameters. Methods: The records of 99 consecutive patients with degenerative thoracolumbar pathology were reviewed and pelvic parameters including sacral slope, pelvic tilt, and pelvic incidence were measured with preoperative standing radiographs. Using 3-dimensional computed tomography (CT) reconstructions, an ideal S2AI trajectory was defined and anteroposterior (horizontal) and cephalocaudal (sagittal) angles were recorded. Results: Pelvic tilt was found to have a moderate inverse correlation with cephalocaudal screw trajectory (r=-0.467, p-value=0.006). Pelvic incidence and sacral slope had weaker correlations with cephalocaudal screw angle. In subgroup analysis, patients with high pelvic tilt (>20°) had a significantly lower cephalocaudal screw trajectory (24.9 ± 3.7° versus 29.8 ± 2.8°, p-value=

STUDY DESIGN.: The enrollment data were retrospectively reviewed for 1,061 patients entered into a prospective multicenter study of adult spinal deformity between January 2002 and June 2004.OBJECTIVE.: The purpose of this study is to quantify and analyze the use of nonsurgical resources in patients with adult spinal deformity.SUMMARY OF BACKGROUND DATA.: Limited data exist regarding the utilization of nonsurgical treatment methods for adult spinal deformity.METHODS.: Demographic data, surgical history, symptom assessment, and nonsurgical treatment regimen were reviewed. Health status measures were the SF-12, SRS-29, and ODI. Nonsurgical patients were divided into low- and high-symptom subgroups based on age adjusted ODI score. Resource utilization was analyzed based on both patient and physician questionnaire responses.RESULTS.: High- and low-symptom nonsurgical subgroups differed significantly on all reported health status measures (P < 0.0001). High-symptom patients used greater resources in terms of narcotics, epidural blocks, and physical agent methods (P < 0.001), analgesics (P < 0.01), pain management referral and bed rest (P < 0.02), strength training, nerve root blocks, and stabilization exercises (P < 0.05).CONCLUSIONS.: The results of this study demonstrate that, within the population of adult deformity patients, distinct high- and low-symptom groups exist and can be clearly identified. While high-symptom patients used significantly greater resources, most low-symptom patients used nonsurgical resources as well. [ABSTRACT FROM AUTHOR]

STUDY DESIGN.: This study is a retrospective review of 752 patients with adult spinal deformity enrolled in a multicenter prospective database in 2002 and 2003. Patients with positive sagittal balance (N = 352) were further evaluated regarding radiographic parameters and health status measures, including the Scoliosis Research Society patient questionnaire, MOS short form-12, and Oswestry Disability Index.OBJECTIVES.: To examine patients with adult deformity with positive sagittal balance to define parameters within that group that might differentially predict clinical impact.SUMMARY OF BACKGROUND DATA.: In a multicenter study of 298 adults with spinal deformity, positive sagittal balance was identified as the radiographic parameter most highly correlated with adverse health status outcomes.METHODS.: Radiographic evaluation was performed according to a standarized protocol for 36-inch standing radiographs. Magnitude of positive sagittal balance and regional sagittal Cobb angle measures were recorded. Statistical correlation between radiographic parameters and health status measures were performed. Potentially confounding variables were assessed.RESULTS.: Positive sagittal balance was identified in 352 patients. The C7 plumb line deviation ranged from 1 to 271 mm. All measures of health status showed significantly poorer scores as C7 plumb line deviation increased. Patients with relative kyphosis in the lumbar region had significantly more disability than patients with normal or lordotic lumbar sagittal Cobb measures.CONCLUSIONS.: This study shows that although even mildly positive sagittal balance is somewhat detrimental, severity of symptoms increases in a linear fashion with progressive sagittal imbalance. The results also show that kyphosis is more favorable in the upper thoracic region but very poorly tolerated in the lumbar spine. [ABSTRACT FROM AUTHOR]

STUDY DESIGN.: Prospective, randomized, unblinded study of iliac crest bone graft (ICBG) versus recombinant human bone morphogenetic protein-2/compression resistant matrix (rhBMP-2/CRM)in a posterolateral instrumented fusion procedure.OBJECTIVES.: Document initial radiographic characteristics, based on computed tomography, with rhBMP-2/CRM for posterolateral fusion at 6 and 12-month intervals.SUMMARY OF BACKGROUND DATA.: As the acceptance of INFUSE bone graft as an ICBG replacement becomes more widespread, surgeons have begun to study applications for rhBMP-2 in posterior spinal fusion. Preclinical studies have examined variables including carrier composition, rhBMP-2 concentration, and rhBMP-2 dose. Pilot studies have been performed with encouraging initial results.METHODS.: Patients with single level lumbar degenerative disease were enrolled in a randomized study of ICBG versus rhBMP-2/CRM in a posterolateral instrumented fusion procedure. Computed tomography scans at 6 and 12 months were graded as demonstrating no fusion (grade 1), partial or limited unilateral fusion (grade 2), partial or limited bilateral fusion (grade 3), solid unilateral fusion (grade 4), or solid bilateral fusion (grade 5).RESULTS.: At our institution, 74 patients (38 rhBMP-2/CRM, 36 ICBG) reached minimum 1-year follow-up and were included in this analysis. Mean fusion grade (scale1–5) at 6 months after surgery was 4.35 in the rhBMP-2/CRM group versus 3.09 in the ICBG group (P < 0.0001). At 1 year after surgery mean fusion grade was 4.62 in the rhBMP-2/CRM group versus 3.77 in the ICBG group (P < 0.0023).CONCLUSIONS.: These early results are encouraging and suggest a more rapid incorporation and development of the fusion mass with rhBMP-2/CRM than iliac crest autograft in a single level posterior instrumented fusion. [ABSTRACT FROM AUTHOR]

STUDY DESIGN.: Retrospective cohort study. OBJECTIVE.: To determine the effect on fusion of adding platelet gel to autologous iliac crest graft. SUMMARY OF BACKGROUND DATA.: Platelet gel is an osteoinductive material prepared by ultra-concentration of platelets and contains multiple growth factors. Proprietary commercial methods are available for harvesting autologous platelet gel concentrates for use as graft supplement in spine fusions. METHODS.: We reviewed 76 consecutive patients who underwent instrumented posterolateral lumbar fusion with autologous iliac crest bone graft mixed with autologous growth factor (AGF). A control group was randomly selected from patients who underwent instrumented posterolateral lumbar fusion with autologous bone graft alone. The groups were matched for age, sex, smoking history, and number of levels fused. Demographic, surgical, and clinical data were collected from medical records. Diagnosis of nonunion was based on exploration during revision surgery or evidence of nonunion on computerized tomography. The Fisher exact test was used to compare fusion rates. RESULTS.: In both groups, mean age was 50 years, and 24% were smokers. The nonunion rate was 25% in the AGF group and 17% in the control group. This difference was not statistically significant (P = 0.18). CONCLUSIONS.: Platelet gel preparation requires blood draws from the patient. This procedure adds to the risk and cost of surgery. The technique for AGF harvest evaluated in this study provides the highest concentration of platelets among the commercially available methods. Despite this, we showed that platelet gel failed to enhance fusion rate when added to autograft in patients undergoing instrumented posterolateral spinal fusion. The authors do not recommend the use of platelet gel to supplement autologous bone graft during instrumented posterolateral spinal fusion. [ABSTRACT FROM AUTHOR]

STUDY DESIGN.: This study is a retrospective review of the initial enrollment data from a prospective multicentered study of adult spinal deformity.OBJECTIVES.: The purpose of this study is to correlate radiographic measures of deformity with patient-based outcome measures in adult scoliosis.SUMMARY OF BACKGROUND DATA.: Prior studies of adult scoliosis have attempted to correlate radiographic appearance and clinical symptoms, but it has proven difficult to predict health status based on radiographic measures of deformity alone. The ability to correlate radiographic measures of deformity with symptoms would be useful for decision-making and surgical planning.METHODS.: The study correlates radiographic measures of deformity with scores on the Short Form-12, Scoliosis Research Society-29, and Oswestry profiles. Radiographic evaluation was performed according to an established positioning protocol for anteroposterior and lateral 36-inch standing radiographs. Radiographic parameters studied were curve type, curve location, curve magnitude, coronal balance, sagittal balance, apical rotation, and rotatory subluxation.RESULTS.: The 298 patients studied include 172 with no prior surgery and 126 who had undergone prior spine fusion. Positive sagittal balance was the most reliable predictor of clinical symptoms in both patient groups. Thoracolumbar and lumbar curves generated less favorable scores than thoracic curves in both patient groups. Significant coronal imbalance of greater than 4 cm was associated with deterioration in pain and function scores for unoperated patients but not in patients with previous surgery.CONCLUSIONS.: This study suggests that restoration of a more normal sagittal balance is the critical goal for any reconstructive spine surgery. The study suggests that magnitude of coronal deformity and extent of coronal correction are less critical parameters. [ABSTRACT FROM AUTHOR]

Abstract Background Lumbar disc herniation (LDH) is a common problem. When surgical treatment is required, the intervention is typically decompression without fusion. Successful return-to-work (RTW) is a standard expectation with these limited procedures. Occasionally, the size or location of the disc herniation suggests the need for fusion, but the inability to RTW is a significant concern in these cases. The purpose of this study is to determine if the addition of lumbar fusion, as compared to decompression alone, will substantially diminish RTW in patients with lumbar disc herniation. Methods This is a longitudinal cohort study using prospectively collected data from the Quality and Outcomes Database (QOD). Patients with LDH, eligible to RTW (not retired, a student, or on disability) with complete 12-month follow-up data, were identified. Standard demographic and surgical variables, patient-reported outcomes (PROs), and RTW status at 3 and 12 months were collected. Results Of the 5062 patients identified, 4560 (90%) had decompression alone and 502 (10%) had a concurrent fusion. Age and gender were similar in the two groups. The fusion group had worse back pain (NRS 6.52 vs. 5.96) and less leg pain (6.31 vs. 7.01) at baseline compared to the no fusion group. Statistically significant improvement in all PROs was seen in both groups. RTW at 3 months post-op was seen in 85% of decompression cases and 66% of cases with supplemental fusion. At 12 months post-op, RTW increased to 93% and 82%, respectively. Conclusion The need for fusion in LDH cases is unusual, seen in only 10% of cases in this series. The addition of fusion decreased the RTW rate from 85 to 66% at 3 months and from 93 to 82% at 12 months post-op. While the difference is significant, the ultimate deterioration in RTW may be less than anticipated. A reasonable RTW rate can still be expected in the rare patient who requires fusion as part of their treatment for LDH.

Abstract Background Recent work has shed light on the potential benefits of cannabinoids for multimodal pain control following orthopedic procedures. The objective of this review was to summarize the available evidence of analgesic and opioid-sparing effects cannabinoids have in orthopedic surgery and identify adverse events associated with their use. Methods A systematic review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines including PubMed, EMBASE, MEDLINE, PsycINFO, and Google Scholar was performed to include all primary, therapeutic studies published on the use of cannabis, and cannabis-derived products in orthopedic surgery. Results The literature review returned 4292 citations. Thirteen publications were found to meet inclusion criteria. Four randomized controlled trials were evaluated while the remaining studies were of quasi-experimental design. Conclusion Research on cannabinoids in orthopedic surgery is mostly of a quasi-experimental nature and is mainly derived from studies where orthopedics was not the primary focus. The overall results demonstrate potential usefulness of cannabinoids as adjunctive analgesics and in mitigating opioid use. However, the current evidence is far from convincing. There is a need to produce rigorous evidence with well-designed randomized controlled trials specific to orthopedic surgery to further establish these effects.