A Matched-Cohort Analysis of Outcomes in Patients with Hereditary Hemochromatosis After Anterior Cervical Discectomy and Fusion.

BACKGROUND: Hereditary hemochromatosis (HH) is a common autosomal recessive disorder. This disease affects gut iron transport, leading to iron overload, which affects immune function, coagulation mechanics, and bone health. Within the spine, HH contributes to decreased bone mineral density and accelerated intervertebral disc degeneration. The purpose of this study was to discover the differences in the rates of common 90-day postoperative complications and 1-year and 2-year surgical outcomes in patients with and without HH after anterior cervical discectomy and fusion (ACDF). METHODS: Using the PearlDiver database, patients with active diagnoses of HH before ACDF were matched to patients without HH using a 1:5 ratio on the basis of age, sex, body mass index, and comorbidities. Postoperative complications were assessed at 90 days, and 1-year and 2-year surgical outcomes were assessed. All outcomes and complications were analyzed using multivariate logistic regression with significance achieved at P < 0.05. RESULTS: Patients with HH had significantly higher rates of 1-year and 2-year reoperation rates compared with patients without HH (29.19% vs. 3.94% and 37.1% vs. 5.93%, respectively; P < 0.001). The rates of 90-day postoperative complications significantly increased in patients with HH including dysphagia, pneumonia, cerebrovascular accident, deep vein thrombosis, acute kidney injury, urinary tract infection, hyponatremia, surgical site infection, iatrogenic deformity, emergency department visit, and hospital readmission. CONCLUSIONS: Patients with HH undergoing ACDF showed increased 90-day postoperative complications and significantly increased rates of 1-year and 2-year reoperation compared with patients without HH. These findings suggest that iron overload may contribute to adverse outcomes in patients with HH undergoing 1-level and 2-level ACDF.

Surgeon-specific risk stratification model for early complications after complex adult spinal deformity surgery.

STUDY DESIGN: Retrospective outcome analysis of a prospectively collected single-surgeon cases OBJECTIVES: Identify risk factors for complications in adult surgical spine deformity patients, develop a surgeon-specific risk stratification model, and predict the likelihood of 6-week postoperative complications based on prospectively collected preoperative measures. Adult spinal deformity surgery is challenging technically as well as economically. Although many risk factors are well known for spine surgery, complications after complex spine deformity surgery remain a significant problem worldwide. METHODS: We reviewed 124 consecutive adult patients who have undergone instrumented spinal fusion with nine or more levels over a 21-month period in a single institution. We extracted data from patient medical records. Complications within the 6 weeks after surgery were identified. Univariate and logistic regression analyses (LRAs) were implemented. We generated a formula based on the LRA predictive algorithm-a numeric probabilistic likelihood statistic representing an individual patient's risk of developing a complication. RESULTS: A total of 34 (27%) patients had complications that were categorized into either 21 (17%) medical or 17 (13.7%) surgical complications, including 3 (2.4%) proximal junctional kyphosis, 8 (6.4%) neurologic deficit, and 9 (6.5%) any wound issue. The predictive model was significant and calibrated using area under the receiver operating characteristics curve analysis. The model correctly classified 83.1% cases. Patients with a three-column osteotomy or history of deep vein thrombosis have 6 and 19 times higher overall complications, respectively, compared with patients without. Patients with a three-column osteotomy or body mass index > 30, respectively, are 24 and 11 times more likely to develop a wound complication. Patients with a three-column osteotomy have 10 times higher rates of surgical complication. CONCLUSIONS: Complex spine deformity is often associated with complications. No single variable effectively predicts postoperative complications for such a complicated situation. However, when all risk factors are considered, patients with three-column osteotomy have a significantly higher chance to develop early complications. LEVEL OF EVIDENCE: Level IV.

Topical tranexamic acid in spinal surgery: A systematic review and meta-analysis.

Tranexamic acid (TXA) is a commonly used antifibrinolytic agent for perioperative blood conservation in several surgical specialties. Although historically administered intravenously, such systemic administration may be accompanied by severe side effects. Thus, the topical usage of TXA has been established in several fields but remains poorly evaluated in spine surgery. In this study, the authors aimed to review the medical literature on topical TXA usage in spine surgery to evaluate its safety and efficacy. We reviewed manuscripts and clinical trials exploring topical TXA usage in spine surgery published by April 1st, 2018. Postoperative blood loss volumes and hospitalization lengths of stay were evaluated with separate meta-analyses. We identified five articles and one unpublished clinical trial that were placebo-controlled and comprised 218 patients receiving topical TXA in spine surgery. Patients receiving topical TXA demonstrated significantly lower postoperative blood loss as compared to the placebo group (Standardized Mean Difference [SMD] 2.21, 95% CI 0.79-3.62, p < 0.001) and had a lower hospitalization duration (MD 0.99, 95% CI 0.49-1.49, p < 0.001). Overall, topical TXA favorably reduced postoperative blood loss and hospitalization duration in patients undergoing spinal surgery. However, further randomized controlled trials will be needed to definitively establish the optimal therapeutic doses needed for hemorrhage management, and the pharmacodynamics of tTXA in spinal surgery.

Dynamic changes in the reflex exam of patients with sub-axial cervical stenosis.

Though dynamic changes in the physical exam of patients being evaluated for cervical spine pathology have been reported, there is limited information on the prevalence and clinical features associated with reflex changes in a population undergoing surgical evaluation for cervical spine pathology. Fifty-one patients with at least grade 1 cervical stenosis on MRI underwent initial surgical evaluation for cervical spine pathology. All patients received complete neurologic examinations including dynamic reflex testing in three positions (neck neutral, extended, and flexed) by 2 spine surgeons. The average age was 58.7 years (range, 34-80), with 28 (55%) patients being male. Stenosis at the symptomatic levels was grade 1 in 18 patients (35%), grade 2 in 11 (21%), and grade 3 in 22 (43%). Twenty-one patients (41%) had a dynamic change in reflex exam. The most common change in reflex exam was seen in the Hoffman's reflex with 14 patients (28%). Patients with grade 3 stenosis were more likely to have a static Hoffman's reflex (64%) compared with grade 1 (17%) and grade 2 (18%) (p < 0.05). Patients with grade 3 stenosis had a higher rate of either a static or dynamic Hoffman's reflex (82%) compared with grade 1 (44%) (p < 0.05), but there was no difference between grade 3 and grade 2 (64%) (Table 2). Dynamic changes in reflex exam are commonly seen in patients being evaluated for symptomatic cervical stenosis. The routine neurologic exam can be supplemented with dynamic reflex testing, especially in cases where clinical history or imaging is concerning for cervical myelopathy.

Prone Position-Induced Quadriceps Transcranial Motor Evoked Potentials Signal Loss-A Case Report.

BACKGROUND: Transcranial motor evoked potential (TcMEP) is widely used intraoperatively to monitor spinal cord and nerve root function. To our knowledge, there is no report regarding TcMEP signal loss purely caused by patient positioning during the spinal procedure. PURPOSE: The objective of this article is to report an intraoperative TcMEP signal loss of a patient with fixed sagittal imbalance posture along with mild hip contractures. STUDY DESIGN: A retrospective case report. METHODS: A 57-year-old man had fixed sagittal imbalance and flexed hip contractures. For a reconstruction surgery of T10 to the sacrum/ilium and L5 pedicle subtraction osteotomy (PSO), he was put in a prone position on a Jackson table. In order to accommodate his fixed hip flexion contracture, thigh pads were not used and pillows were placed under his bilateral thighs for cushioning. TcMEPs were used to assess lumbar nerve root function. Ten minutes after incision, bilateral vastus medialis TcMEPs were lost during spine exposure whereas all other data remained normal at baseline. The bilateral lower extremities were repositioned, with the knees flexed into a sling position to increase hip flexion. Five minutes after repositioning, the bilateral vastus medialis TcMEPs gradually improved and maintained baseline amplitude during the remainder of the surgery. RESULTS: No muscle weakness was detected immediately after surgery. The patient was discharged day 6 postoperatively with markedly improved posture and alignment. CONCLUSION: Insufficient hip flexion in patients with fixed sagittal imbalance and hip flexion contractures may cause TcMEP signal changes in the quadriceps response. TcMEP monitoring of bilateral lower extremities is highly recommended for patients with sagittal imbalance and hip contractures, with consideration for lower extremity repositioning when data degradation does not correlate with the actual spinal procedure being performed.

Utilization of the 3D-printed spine model for freehand pedicle screw placement in complex spinal deformity correction.

BACKGROUND: We aim to demonstrate the safety and efficacy of utilizing 3D-printed spine models to facilitate freehand pedicle screw placement in complex spinal deformity correction. Currently there is no data on using 3D-printed models for freehand pedicle screw placement spinal deformity correction. METHODS: All patients undergoing spinal deformity correction over a 16-month period (September 2015 - December 2016) at the Spine Hospital of Columbia University Medical Center by the senior surgeon were reviewed. 3D-printed spine models were used to facilitate intraoperative freehand pedicle screw placement in patients with severe spinal deformities. Intraoperative O-arm imaging was obtained after pedicle screw placement in all patients. Screws were graded as intrapedicular, <2 mm breach, 2-4 mm breach, and >4 mm breach; anterior breaches >4 mm were also recorded. Screw accuracy was compared to a historical cohort (not using 3D-printed models) using SPSS 23.0 (Chicago, IL, USA). RESULTS: A total of 513 freehand pedicle screws were placed from T1 to S1 in 23 patients. Overall, 494 screws (96.3%) were placed in acceptable positions according to the pre-operative plan, which had no statistically significant difference (P=0.99) compared to a historical cohort with less severe deformities. There were 84.2% screw that were intrapedicular or <2 mm breach; among the 81 screws (15.8%) with >2 mm breach, 67 were lateral breaches (most are intended juxtapedicular placement), whereas 14 were medial breaches. There were 11 screws (2.1%) that required repositioning due to pedicle violation, and eight screws (1.6%) had >4 mm anterior breach and required shortening. There was no neuromonitoring change or any other complications directly or indirectly related to freehand pedicle screw placement. CONCLUSIONS: The 3D-printed spinal model can make freehand pedicle screw placement safer in severe spinal deformity cases with acceptable accuracy, and no neurological or vascular complications.

High prevalence of greater trochanteric pain syndrome among patients presenting to spine clinic for evaluation of degenerative lumbar pathologies.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) is a relatively common diagnosis among the general population. OBJECTIVE: We aim to determine the prevalence of GTPS among patients who presented to the spine clinic. METHODS: Medical records of patients who were evaluated in the spine clinic were reviewed over a 12-month period (4/1/2016 to 3/31/2017). Patient demographics, presenting symptomatology, physical examination findings, presence or absence of GTPS, medical imaging findings, and interventions were recorded analyzed. Statistical analysis was performed using SPSS Statistics 23.0 (Chicago, IL). Statistical significance is defined as p < 0.05. RESULTS: A total of 273 consecutive patients (145 women, 128 men) were evaluated for degenerative lumbar pathologies by a single spine surgeon over the study period. The average patient age was 61.9 years. Overall, there were 138/273 patients (50.5%) with GTPS (Group I), while 135/273 patients (49.5%) did not have GTPS (Group II). There were 73 patients in Group I received trochanteric injection for GTPS treatment and subsequently returned to clinic for follow-up, and there were 36/73 (49.3%) patients reporting improvement in their symptoms after trochanteric injection. There was a statistically significant predilection for presence of GTPS in the female gender (60% vs 32.8%, p = <0.01). There was no statistically significant difference in the prevalence of low back pain, buttock, thigh or groin pain between the two groups. CONCLUSION: GTPS is a very common but often unrecognized or misdiagnosed condition. Accurate diagnosis and differentiation of GTPS from lumbar spinal pathologies are essential in avoiding potential unnecessary spinal procedures.

Rheumatoid Arthritis Is Associated With an Increased Risk of Postoperative Infection and Revision Surgery in Elderly Patients Undergoing Anterior Cervical Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: To identify the incidence and analyze the risk of postoperative complications amongst elderly patients with rheumatoid arthritis undergoing anterior cervical fusion. SUMMARY OF BACKGROUND DATA: Previous studies have reported elevated risks of postoperative complications for patients with rheumatoid arthritis undergoing orthopedic procedures. However, little is known about the risk of postoperative complications in rheumatoid arthritis patients after spine surgery. METHODS: A commercially available database was queried for all Medicare patients 65 years of age and older undergoing one- or two-level primary anterior cervical fusion surgeries from 2005 to 2013. Complications, hospitalization costs, and length of stay were queried. Multivariate logistic regression analyses were performed to estimate the odds ratio for each complication adjusted for age, sex, and Charlson Comorbidity Index. RESULTS: A total of 6067 patients with a history of rheumatoid arthritis and 113,187 controls were identified. Significantly higher incidences of major medical complications (7.5% vs. 5.9%, P < 0.001), postoperative infections (2.6% vs. 1.5%, P < 0.001), and revision surgery (1.1% vs. 0.6%, P < 0.001) were observed amongst the rheumatoid arthritis cohort. Significantly greater average cost of hospitalization ($17,622 vs. $12,489, P < 0.001) and average length of stay (3.13 vs. 2.08 days, P < 0.001) were also observed. CONCLUSION: Patients with rheumatoid arthritis undergoing anterior cervical fusion face increased risks of postoperative infection and revision surgery compared to normal controls. This information is valuable for preoperative counseling and risk stratification. LEVEL OF EVIDENCE: 3.

Intervertebral disk-like biphasic scaffold-demineralized bone matrix cylinder and poly(polycaprolactone triol malate)-for interbody spine fusion.

Interbody fusion is an established procedure to preserve disk height and anterior fusion, but fusion with autografts, allografts, and metallic cages has its endogenous shortcomings. The objective of this study is to investigate whether a biphasic scaffold model, the native demineralized bone matrix cylinder in conjunction with degradable biomaterial poly(polycaprolactone triol malate), can be employed as a biological graft for interbody fusion. The poly(polycaprolactone triol malate) was synthesized by polycondensing malic acid and polycaprolactone and then the concentric sheet of poly(polycaprolactone triol malate) was fabricated into the demineralized bone matrix cylinder derived from rabbit femurs. Rabbit chondrocytes were loaded onto the three-dimensional constructs with 1-day in vitro culture and implanted into the subcutaneous dorsal pocket of nude mice. The chondrocytes/scaffold constructs are approximately two folds bigger than the scaffold-alone constructs after 12 weeks of implantation. X-ray and micro-computed tomography imaging showed endochondral bone formation in the chondrocytes/scaffold constructs as early as 4 weeks and showed that the bone intensity increased over time. Histological staining confirmed the above observation. By week 8, lamellar bone tissues were formed inside the demineralized bone matrix cylinder. In addition, the compression biomechanical test showed that the chondrocytes/scaffold constructs produced a significant higher compressive strength compared to the scaffold group. These results demonstrated that the inner-phase poly(polycaprolactone triol malate) degraded over time and was replaced by new bone in an in vivo environment.