Ligamentous Augmentation to Prevent Proximal Junctional Kyphosis and Failure: A Biomechanical Cadaveric Study.

STUDY DESIGN: Biomechanical cadaveric study (level V). OBJECTIVE: To evaluate the effectiveness of polyethylene bands looped around the supra-adjacent spinous process (SP) or spinal lamina (SL) in providing strength to the cephalad unfused segment and reducing junctional stress. BACKGROUND: Proximal junctional kyphosis (PJK) is a pathologic kyphotic deformity adjacent to posterior spinal instrumentation after fusion constructs. Recent studies demonstrate a mismatch in stiffness between the instrumented construct and nonfused adjacent levels to be a causative factor in the development of PJK and proximal junction failure. To our knowledge, no biomechanical studies have addressed the effect of different methods of polyethylene band placement at the proximal junction. MATERIALS AND METHODS: Twelve fresh frozen cadavers were divided into 3 groups of 4: pedicle screw-based instrumentation from T10 to L5 ("control"), T10-L5 instrumentation with a polyethylene band to the T9 "SP," T10-L5 instrumentation with 2 polyethylene bands to the T9 "SL." Specimens were tested with an eccentric (10 mm anterior) load at 5 mm/min for 15 mm or until failure occurred. Failure was defined by the inflection point on the load versus deformation curves. Linear regression was utilized to evaluate the effect of augmentation on the load-to-failure. Significance was set at 0.05. RESULTS: Fractures occurred in all specimens tested. The mean peak load to failure was 2148 N (974-3322) for the SP group, and 1248 N (742-1754) for the control group (P > 0.05) and 1390 N (1080-2004) for the SL group. No difference existed between the control group and the SP group in terms of fracture level (P > 0.05). Net kyphotic angulation shows no differences among these 3 groups (P > 0.05). CONCLUSION: Although statistical significance was not achieved, ligament augmentation to the SP increased mean peak load-to-failure in a cadaveric PJK model.

Sagittal Pelvic Kinematics in Hip Arthroplasty.

PURPOSE OF REVIEW: The orientation of the spine relative to the pelvis-particularly that in the sagittal plane-has been shown in both kinematic and radiographic studies to be paramount in governance of acetabular alignment during normal bodily motion. The purpose of this review is to better understand the challenges faced by arthroplasty surgeons in treating patients that have concurrent lumbar disease and are therefore more likely to have poorer clinical outcomes after THA than in patients without disease. RECENT FINDINGS: The concept of an "acetabular safe zone" has been well described in the past regarding the appropriate orientation of acetabular component in THA. However, this concept is now under scrutiny, and rising forth is a concept of functional acetabular orientation that is based on clinically evaluable factors that are patient and motion specific. The interplay between the functional position of the acetabulum and the lumbar spine is complex. The challenges that are thereby faced by arthroplasty surgeons in terms of proper acetabular cup positioning when treating patients with concomitant lumbar disease need to be better understood and studied, so as to prevent catastrophic and costly complications such as periprosthetic joint dislocations and revision surgeries.

Risk Factors for Readmission After Surgical Treatment of Slipped Capital Femoral Epiphysis.

Slipped capital femoral epiphysis (SCFE) is a common, surgically treated adolescent hip condition. This study sought to evaluate postoperative complications and factors associated with hospital readmission using a nationally representative database. The 2013 Healthcare Cost and Utilization Project's Nationwide Readmissions Database was queried to analyze the incidence of acute readmission and complications for all patients with SCFE. Patients were separated based on 3 different operative approaches (open procedures, closed procedures, or both) and were compared based on choice of procedure, clinical characteristics, patient demographics, comorbidities, and complications. Univariate and multivariate techniques were used to predict readmission and complications. A total of 1082 patients with SCFE were identified; 58 (5.9%) were readmitted within 90 days of the index surgery, and 47 (73.4%) underwent a "closed" surgery, including 18 bilateral (27.4%). Increasing age and shorter primary length of stay were protective against readmission. Patients with the comorbidity of hypothyroidism were 47.4 times more likely to be readmitted. Obesity, sex, and median household income were not predictive of readmission. Patients readmitted were more likely to have undergone an index procedure of closed reduction or both an open and closed reduction procedure. This study is the first to report national SCFE readmission and complication rates and allows pediatric orthopedic surgeons to have a better understanding of associated risk factors. [Orthopedics. 2019; 42(6):e507-e513.].

National Databases in Pediatric Orthopaedic Surgery: A Comparison of Demographics, Procedures, and Outcomes.

BACKGROUND: Large national databases have been increasingly used in recent years to determine the rate of adverse events and identify factors associated with altered surgical outcomes. This can be especially useful to evaluate rare events such as 30-day mortality. Despite differences between national pediatric databases, there have been no comparison studies in the pediatric orthopaedic population. METHODS: The Healthcare Cost and Utilization Project's Kids' Inpatient Database (KID) along with the American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP Pediatric) databases were queried to identify common pediatric orthopaedic procedures for humeral fractures, scoliosis, slipped capital femoral epiphysis, and femoral fractures during a single year. Clinical characteristics and complications in the 2 databases were compared using Student t test, χ, or Fisher' exact test. RESULTS: In total, 26,978 patients in the KID and 5186 patients in the NSQIP Pediatric databases were identified. Large differences were observed between the databases in identical procedure categories with respect to age, race, sex, and length of stay. Regardless of procedure, NSQIP Pediatric had statistically higher reported rates of cumulative complications. Surgical site infections and sepsis were consistently observed to be at least twice as common in the NSQIP Pediatric database in comparison to the KID. Overall, complication rates ranged from <1% in humeral fractures to >100% in neuromuscular scoliosis. CONCLUSIONS: Clinically and statistically significant differences exist between the KID and NSQIP Pediatric databases. Clinicians and researchers who utilize large databases must understand the differences in data import, quality control, and population sampling in order to provide adequate representation of the population as a whole. LEVEL OF EVIDENCE: Level III, prognostic study.

Early Clinical and Economic Outcomes of Prophylactic and Acute Pathologic Fracture Treatment.

INTRODUCTION: Pathologic fractures often contribute to adverse events in metastatic bone disease, and prophylactic fixation offers to mitigate their effects. This study aims to analyze patient selection, complications, and in-hospital costs that are associated with prophylactic fixation compared with traditional acute fixation after completed fracture. MATERIALS AND METHODS: The Nationwide Inpatient Sample database was queried from 2002 to 2014 for patients with major extremity pathologic fractures. Patients were divided by fixation technique (prophylactic or acute) and fracture location (upper or lower extremity). Patient demographics, comorbidities, complications, hospitalization length, and hospital charges were compared between cohorts. Preoperative variables were analyzed for potential confounding, and χ2 tests and Student's t tests were used to compare fixation techniques. RESULTS: Cumulatively, 43,920 patients were identified, with 14,318 and 28,602 undergoing prophylactic and acute fixation, respectively. Lower extremity fractures occurred in 33,582 patients, and 10,333 patients had upper extremity fractures. A higher proportion of prophylactic fixation patients were white ( P = .043), male ( P = .046), age 74 years or younger ( P < .001), and privately insured ( P < .001), with decreased prevalence of obesity ( P = .003) and/or preoperative renal disease ( P = .008). Prophylactic fixation was also associated with decreased peri- and postoperative blood transfusions ( P < .001), anemia ( P < .001), acute renal failure ( P = .010), and in-hospital mortality ( P = .031). Finally, prophylactic fixation had decreased total charges (-$3,405; P = .001), hospitalization length ( P = .004), and extended length of stay (greater than 75th percentile; P = .012). CONCLUSION: Prophylactic fixation of impending pathologic fractures is associated with decreased complications, hospitalization length, and total charges, and should be considered in appropriate patients.

Traumatic Lumbosacral Dislocation: Current Concepts in Diagnosis and Management.

Traumatic lumbosacral dislocation is a rare, high-energy mechanism injury characterized by displacement of the fifth lumbar vertebra in relation to the sacrum. Due to the violent trauma typically associated with this lesion, there are often severe, coexisting injuries. High-quality radiographic studies, in addition to appropriate utilization of CT scan and MRI, are essential for proper evaluation and diagnosis. Although reports in the literature include nonoperative and operative management, most authors advocate for surgical treatment with open reduction and decompression with instrumentation and fusion. Despite advances in early diagnosis and management, this injury type is associated with significant morbidity and mortality, and long-term patient outcomes remain unclear.

Stability of the Subaxial Spine after Penetrating Trauma: Do Classification Systems Apply?

OBJECTIVE: Blunt spinal trauma classification systems are well established and provide reliable treatment algorithms. To date, stability of the spine after civilian gunshot wounds (CGSWS) is poorly understood. Herein, we investigate the validity of trauma classification systems including the Thoracolumbar Injury Classification and Severity Score (TLICS), Subaxial Cervical Spine Injury Classification and Severity Score (SLIC), and Denis' three-column model when applied to spinal penetrating trauma from gunshots, while secondarily evaluating stability of these injuries. METHODS: Gunshot injuries to the spine were identified from an institutional database from ICD-nine codes. Trauma scorings systems were applied using traditional criteria. Neurologic compromise and spinal stability were evaluated using follow-up clinic notes and radiographs. RESULTS: Thirty-one patients with CSGSW were evaluated. There was an equal distribution of injuries amongst the spinal levels and spinal columns. Twenty patients had neurological deficits at presentation. Eight patient had a TLICS score >4. Three patients had a SLIC score >4. One patient had surgical treatment. Nonoperative treatment did not lead to spinal instability or adverse outcomes in any cases. The posterior column had a high correlation with neurologic compromise, though not statistically significant (p=.118). CONCLUSIONS: The TLICS, SLIC, and three-column classification systems cannot be applied to CSGSW to quantify injury severity, predict outcomes, or guide treatment decision-making. Despite significant neurologic injuries and disruption of multiple spinal columns, CSGSW do not appear to result in unstable injuries requiring operative intervention. Further research is needed to identify the rare spinal gunshot injury that would benefit from immediate surgical intervention.

The Significance of Upper Extremity Neuromonitoring Changes During Thoracolumbar Spine Surgery.

STUDY DESIGN: This is a retrospective matched-pair cohort study. OBJECTIVE: To investigate the significance of upper extremity (UE) neuromonitoring changes in patients undergoing thoracolumbar surgery in prone position. SUMMARY OF BACKGROUND DATA: Peripheral nerve injuries in the UEs due to the prone positioning during prolonged thoracolumbar spinal procedures can cause diminished postsurgical outcomes. Intraoperative neuromonitoring has been utilized to alert the surgeon of the development of such injuries. MATERIALS AND METHODS: Patients who developed intraoperative ulnar somatosensory-evoked potential (SSEP) signal changes during posterior thoracolumbar surgery were identified and compared with a group of patients who did not develop such signal changes. The patients in 2 groups were pair-matched on the number of vertebral levels undergoing surgery. Data regarding intraoperative attempts to resolve signal changes and outcomes were collected. RESULTS: In total, 843 patients underwent thoracic, lumbar, or thoracolumbar spine surgeries in the prone position with intraoperative ulnar SSEPs neuromonitoring data available. Of these, 37 patients (4.4%) had intraoperative signal changes in the UEs. An equal number of patients without signal changes were also selected. In each group, 6 patients underwent thoracic, 20 patients underwent lumbar, and 11 patients underwent thoracolumbar procedures. In 8 patients (21.6%), there was no resolution of SSEP signal changes despite intraoperative attempts. The 2 groups were similar with respect to age and comorbidities. There was no significant difference in the mean body mass index (P=0.22). The mean duration of the procedures was 324 minutes in the SSEP signal change patients and 260 minutes in the patients without SSEP signal changes (P=0.03). No patient with UE SSEP changes had a clinically detectable neurological deficit postoperatively. CONCLUSIONS: UE SSEP signal changes during multilevel posterior thoracolumbar procedures are more likely to occur as the duration of the operation increases. The presence of UE signal changes does not coincide with clinically significant peripheral neuropathies. LEVEL OF EVIDENCE: Level III.

Spinopelvic Dissociation: Comparison of Outcomes of Percutaneous versus Open Fixation Strategies.

INTRODUCTION: Spinopelvic dissociation injuries are historically treated with open reduction with or without decompressive laminectomy. Recent technological advances have allowed for percutaneous fixation with indirect reduction. Herein, we evaluate outcomes and complications between patients treated with open reduction versus percutaneous spinopelvic fixation. METHODS: Retrospective review of patients undergoing spinopelvic fixation from a single, level one trauma center from 2012 to 2017. Patient information regarding demographics, associated injuries, and treatment outcome measures was recorded and analyzed. All fractures were classified via the AO Spine classification system. RESULTS: Thirty-one spinopelvic dissociations were identified: 15 treated with open and 16 with percutaneous techniques. The two treatment groups had similar preoperative characteristics including spinopelvic parameters (pelvic incidence and lumbar lordosis). Compared to open reduction internal fixation, percutaneous fixation of spinopelvic dissociation resulted in statistically significantly lower blood loss (171 cc versus 538 cc; p = 0.0013). There were no significant differences in surgical site infections (p = 0.48) or operating room time (p = 0.66). CONCLUSION: Percutaneous fixation of spinopelvic dissociation is associated with significantly less blood loss. Treatment outcomes in terms of infection, length of stay, operative cost, and final alignment between the open and percutaneous group were similar.

Type III odontoid fractures: A subgroup analysis of complex, high-energy fractures treated with external immobilization.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Type III odontoid fractures are classically treated nonoperatively, yet, the current literature on Type III odontoid fractures includes fractures of multiple etiologies and fracture morphologies. We hypothesize that a subgroup of complex, Type III fractures caused by high-energy mechanisms are more likely to fail nonoperative treatment. MATERIALS AND METHODS: Acute Type III odontoid fractures were identified at a single institution from 2008 to 2015. Fractures were categorized as high- or low-energy fracture with high-energy fractures defined as those with lateral mass comminution (>50%) or secondary fracture lines into the pars interarticularis or vertebral body. Patients were treated in either a hard collar orthosis or halo vest and were followed for fracture union and stability. RESULTS: One hundred and twenty-five Type III odontoid fractures were identified with 51% classified as complex fractures. Thirty-three patients met the inclusion and exclusion criteria including 15 patients treated in a halo vest and 18 in a hard collar orthosis. Mean follow-up was 32 (±44) weeks. Seven patients demonstrated progressive displacement of either 2 mm of translation or 5° of angulation and underwent delayed surgical stabilization. Two additional patients required delayed surgery for nonunion and myelopathy. Initial fracture displacement and angulation were not correlative with final outcome. No statistical advantage of halo vest versus hard collar orthosis was observed. CONCLUSIONS: Complex Type III odontoid fractures are distinctly different from low-energy injuries. In the current study, 21% of patients were unsuccessfully treated nonoperatively with external immobilization and required surgery. For complex Type III fractures, we recommend initial conservative treatment, while maintaining close monitoring throughout patient recovery and fracture union.

Conservative Treatment of Hangman Variant Fractures.

STUDY DESIGN: This is retrospective cohort study. OBJECTIVE: Investigate the stability of patients with hangman variant fractures and outcomes of treatment with external immobilization. SUMMARY OF BACKGROUND DATA: Traumatic spondylolisthesis of the axis (C2) with the fracture extending into the vertebral body has been incompletely characterized. Small case series have showed high rates of neurological injury and cite difficulty treating closed due to greater instability secondary to extensive ligamentous injury. MATERIALS AND METHODS: Retrospectively, all patients admitted to a level 1 trauma center from 2004 to 2015 with acute C2 fractures were identified and classified based on computed tomographic imaging. Study cohort included patients with anterior translation <5 mm and C2-3 angulation <15 degrees that were followed to conclusion of treatment. RESULTS: In total, 107 hangman's variant fractures (14.5%) were identified from a database of 735 acute C2 fractures. In total, 106 of the 107 patients displayed no neurological injury related to the cervical spine at the time of presentation. A total of 63 patients met the inclusion criteria and were followed as outpatients until collar or halo vest removal. All fractures progressed to union without progressive displacement or late neurological injury. No difference was observed in radiographic outcome between patients treated in a hard collar versus halo orthosis. CONCLUSIONS: Although widely considered a difficult fracture to treat with closed means, hangman variants are relatively neurologically benign injuries with low incidence of ligamentous injury. Fractures with <5 mm of horizontal translation and 15 degrees of angulation can be treated with external immobilization. Our results suggest no advantage of halo immobilization versus hard collar orthosis.

Unstable C1 Fracture Managed with Internal Fixation Using Lateral Mass Screws: A Case Report.

CASE: A 47-year-old woman presented with an unstable C1 fracture after falling down several stairs. She was found to have a sagittal split fracture of the right C1 lateral mass extending into the posterior arch. The fracture was treated with a direct posterior osteosynthesis of C1 using lateral mass screws. CONCLUSION: Surgical management of unstable C1 fractures has traditionally involved posterior fusion of C1 to C2 or fusion from the occiput to C2. These fusion procedures can be quite functionally limiting. Recently, direct osteosynthesis of C1 has been shown to be an effective, motion-preserving alternative.

Ability of magnetic resonance imaging to accurately determine alar ligament integrity in patients with atlanto-occipital injuries.

OBJECTIVE: The objective of this study is to evaluate the the reliability of magnetic resonance imaging (MRI) in diagnosing alar ligament disruption in patients with potential atlanto-occipital dissociation (AOD). MATERIALS AND METHODS: Three-blinded readers performed retrospective review on 6 patients with intra-operative confirmed atlanto-occipital dissocation in addition to a comparison cohort of patients with other cervical injuries that did not involve the atlanto-occipital articulation. Ligament integrity was graded from 1 to 3 as described by Krakenes et al. The right and left ligaments were assessed separately. Inter-observer agreement by patient, by group (AOD vs. non-AOD), and intra-observer agreement was calculated using weighted Cohen's kappa. RESULTS: Interobserver agreement of alar ligament grade for individual patients ranged from slight to fair (κ = 0.05-0.30). Interobserver agreement of alar ligament grade for each group (AOD vs. non-AOD) ranged from fair to substantial (κ = 0.37-0.66). No statistically significant difference in categorical analysis of groups (AOD vs. non-AOD) and grade (0-1 vs. 2-3) was observed. Intraobserver agreement of individual patient's alar ligament grade ranged from moderate to substantial (κ = 0.50-0.62). CONCLUSION: The use of MRI to detect upper cervical ligament injuries in AOD is imperfect. Our results show inconsistent and unsatisfactory interobserver and intraobserver reliability in evaluation of alar ligament injuries. While MRI has immense potential for detection of ligamentous injury at the craniovertebral junction, standardized algorithms for its use and interpretation need to be developed.

Risk factors for same-admission mortality after pathologic fracture secondary to metastatic cancer.

PURPOSE: The skeleton is the third most common site of cancer metastases. Approximately 10 % of patients with bone metastases will develop a pathologic fracture, with significant associated morbidity and mortality. The purpose of this study was to identify risk factors for same-admission mortality after pathologic fractures secondary to metastatic cancer. METHODS: The Nationwide Inpatient Sample database was queried from 2002 to 2013 for hospitalized patients with diagnoses of pathologic fracture and a primary cancer at high risk for skeletal metastasis. Univariate and multivariate analyses were performed to determine risk factors associated with same-admission mortality after fracture. RESULTS: A total of 371,163 patients were identified. The spine was the most common site of pathologic fracture (68.0 %) followed by lower extremity (25.0 %) and upper extremity (8.7 %). The following factors were independently associated with increased mortality (p < 0.001): cancer of lung or unspecified location; fracture of upper or lower extremity; male gender; age ≥65; non-Medicare insurance; coexisting congestive heart failure, chronic pulmonary disease, renal failure, or liver disease; and postoperative surgical site infection, acute myocardial infarction, pulmonary embolism, or pneumonia. Closed reductions were associated (p < 0.001) with increased mortality while open or percutaneous surgical treatments were protective (p < 0.001) against mortality. CONCLUSIONS: Pathologic fractures are a devastating consequence of metastatic bone disease, contributing significantly to morbidity and mortality. Numerous demographic and medical factors are associated with increased same-admission mortality. This data is useful for counseling patients with skeletal metastatic disease and should be taken into consideration when conducting routine skeletal surveillance in patients with metastatic cancer.

Concomitant Lumbar Stenosis and Aortic Pseudoaneurysm: A Case Report.

Aortic pseudoaneurysm can create a constellation of symptoms that can mimic lumbar back pain. There are rare but well-documented reports of aortic pathology (aneurysms, pseudoaneurysms, and chronic contained aneurysm ruptures) eroding into the vertebral column causing neural compression. We report a case of a rapidly progressive aortic pseudoaneurysm in a patient with pre-existing lumbar spine pathology which had the potential for catastrophic intraoperative bleeding during a minimally invasive surgery (MIS) using the transforaminal lumbar interbody fusion (TLIF) technique. Postoperatively, the patient's radicular pain resolved but her back pain remained. Further workup identified the pseudoaneurysm and the patient subsequently underwent open vascular repair. In this report, we highlight a lesser known mimicker of lumbar back pain.

Risk factors for infection after operative fixation of Tibial plateau fractures.

INTRODUCTION: Tibial plateau fractures are challenging to treat due to the high incidence of postoperative infections. Treating physicians should be aware of risk factors for postoperative infection in patients who undergo operative fixation. PATIENTS AND METHODS: A retrospective review was undertaken to identify all patients with tibial plateau fractures over a 10 year period (2003-2012) who underwent open reduction internal fixation. A total of 532 patients were identified who met the inclusion criteria. Several patient and clinical characteristics were recorded, and those variables with a significant association (p<0.05) with postoperative infection after a univariate analysis were further analyzed using a multivariate analysis. RESULTS: Fifty-nine (11.1%) of the 532 patients developed a deep infection. The average length of follow-up for patients was 19.5 months. Methicillin-resistant Staphylococcus aureus was the most common species, and it was isolated in 26 (44.1%) patients. Open fractures, the presence of compartment syndrome, and a Schatzker type IV-VI were found to be independent risk factors for deep infection. CONCLUSIONS: The rate of deep infection remains high after operative fixation of tibial plateau fractures. Patients with risk factors for infection should be counseled on the possibility of reoperation, and surgeons should consider MRSA prophylaxis in those patients who are at higher risk.

Insufficiency fracture associated with oncogenic osteomalacia.

Oncogenic osteomalacia is a rare paraneoplastic syndrome of systemic bone demineralization secondary to a tumor-induced dysregulation of phosphorus metabolism. The tumor's low prevalence, small size, and variable location often result in years of muscular weakness and bone pain before diagnosis. With complete treatment, patient's symptoms swiftly dissipate. We report the case of a 63-year-old previously healthy man with a 20-month course of musculoskeletal symptoms before diagnosis and resection of a posterior tibial tumor. Postoperatively, the patient had returned to his previous lifestyle when an insufficiency fracture required prophylactic stabilization.