Fractures in the ankylosed spine are associated with poor bone quality and lower hounsfield units.

STUDY DESIGN: Retrospective study INTRODUCTION: Patients with ankylosing spinal disorders have a higher risk of fractures, highlighting the need for bone health surveillance. Bone assessment by dual energy x-ray absorptiometry (DXA) is challenging due to abnormal bone formation but measurements by quantitative computed tomography (qCT) have demonstrated higher sensitivity and specificity. However, no studies have analyzed bone quality using qCT in the ankylosed spine population to assess three-column fracture characteristics and subsequent outcomes. METHODS: 106 patients with 115 three-column fractures were identified from 1999 to 2020. Patient demographics, Charlson comorbidity index, and injury severity score were extracted. Bone quality measured in Hounsfield units (HU), fracture characteristics, neurologic injury, and mortality were obtained. RESULTS: Most injuries occurred in the thoracic spine (70.4%) following a ground level fall (60.5%). HU adjacent to the fracture (127 HU) was significantly lower than the mobile segments (173 HU) (p < 0.001). Fracture adjacent HU was significantly lower in AS patients compared to DISH (109 vs 150 HU, p = 0.02, respectively) and were lower in fractures that resulted in a non-union or revision surgery (88 vs 137 HU, p = 0.04). Patients with longer fused segments were associated with multilevel and displaced fractures. CONCLUSIONS: Fracture adjacent HUs within the autofused segments were significantly lower than in the mobile segments, and longer fusion segments were associated with displaced, multilevel fractures. This study reinforces the importance of assessing patients for decreased HUs as well as better understand how the length of fused segments is associated with displaced, multilevel fractures. LEVEL OF EVIDENCE: Level III.

Outcomes of Recurrent Mobile Spine Chordomas.

INTRODUCTION: Chordomas of the mobile spine are rare malignant tumors. The purpose of this study was to review the outcomes of treatment for patients with recurrent mobile spine chordomas. METHODS: The oncologic outcomes and survival of 30 patients undergoing treatment of a recurrent mobile spine chordoma were assessed over a 24-year period. The mean follow-up was 3.5 years. RESULTS: In patients presenting with a recurrent mobile spine chordoma, the mean 2- and 5-year overall survival was 73% and 39%, respectively. Enneking appropriate resection trended toward improved overall survival at 5 years (100% vs. 32%, P = 0.24). Those undergoing surgical resection for recurrence had improved metastatic-free survival (hazard ratio 0.29, CI 0.08 to 0.99, P = 0.05). Positive margins were found to be a risk factor of further local recurrence (hazard ratio 7.92, CI 1.02 to 61.49, P = 0.04). Those undergoing nonsurgical management trended toward having an increase in new neurologic deficits (P = 0.09), however, there was no difference in overall complications based on treatment type (P = 0.13). CONCLUSION: Recurrent mobile spine chordoma portends a poor prognosis with an overall survival of less than 40% at 5 years. Surgical resection may help prevent new neurologic deficits and tumor metastasis while en bloc excision with negative surgical margins is associated with improved local recurrence-free survival.

Postoperative and Intraoperative Cement Augmentation for Spinal Fusion.

OBJECTIVE: To review outcomes of patients undergoing spinal fusion with prophylactic cement augmentation (CA) of pedicle screws and adjacent levels. METHODS: In a retrospective case-control study, 59 patients underwent CA of pedicle screws for spinal fusion between 2003 and 2018. Most patients (83%) underwent postoperative CA, while 17% underwent intraoperative CA. Outcomes of CA techniques were compared, and patients undergoing CA for a thoracolumbar fusion (n = 51) were compared with a cohort not undergoing CA (n = 39). Mean follow-up was 3 years. RESULTS: In patients receiving CA, survivorship free of proximal junctional kyphosis (PJK) was 94%, 60%, and 20% at 2, 5, and 10 years postoperatively. Survivorship free of revision was 95%, 83%, and 83% at 2, 5, and 10 years postoperatively. Development of PJK (P = 0.02, odds ratio [OR] 24.44) was associated with revision surgery. There were 4 (7%) cardiopulmonary complications. Patients who received CA for thoracolumbar fusion were older (70 years vs. 65 years) and were more likely to have osteoporosis (53% vs. 5%) than patients who did not receive CA. CA was associated with a decreased risk of PJK (P = 0.009, OR 0.16), while osteoporosis (P = 0.05, OR 4.10) and fusion length ≥8 levels (P = 0.06, OR 2.65) were associated with PJK. PJK was associated with revision surgery (P = 0.006, OR 12.65). CONCLUSIONS: CA allows for substantial rates of radiographic PJK; however, this typically does not result in a need for revision surgery and leads to revision and PJK rates that are comparable to patients undergoing long segment fusions without osteoporosis.

Hidden blood loss in adolescent idiopathic scoliosis surgery.

INTRODUCTION: Posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS) have higher blood loss than other pediatric orthopedic surgeries. There is a paucity of literature estimating the hidden blood loss (HBL) in patients with AIS undergoing PSF. The purpose of this study was to compare intraoperative and postoperative estimated blood loss (EBL) in patients undergoing PSF for AIS to determine HBL. HYPOTHESIS: With contemporary blood loss prevention strategies, HBL will be higher than intraoperative EBL. MATERIAL AND METHODS: Over a 3-year period, 67 patients with preoperative and postoperative hemoglobin (Hgb) measurements undergoing PSF for AIS were evaluated. Intraoperative EBL was estimated using a volumetric method and recorded by a perfusionist managing a cell saver machine. Total perioperative EBL was estimated using the validated formula: EBL=weight (kg)×age sex factor×(preoperative Hgb - postoperative Hgb)/preoperative Hgb. HBL was calculated as the total perioperative EBL minus the intraoperative EBL. RESULTS: Calculated total EBL was higher than intraoperative EBL (771±256mL vs. 110±115mL, p<0.001). Mean HBL after wound closure was 660±400mL. Patients 14 years or greater (p=0.03), with a BMI≥25kg/m2(p=0.02) and with surgical times over 3.5hours (p=0.05) had increased HBL. Multivariate analysis determined BMI≥25kg/m2 (OR 9.91; CI, 1.01-104.26; p=0.05) was associated with increased HBL. Allogenic blood transfusion was rare (4%) and associated with increased HBL (897±112mL vs. 540±402mL, p=0.05). DISCUSSION: For patients undergoing PSF for AIS there is more HBL after wound closure than intraoperative blood loss. This HBL is higher in older patients who undergo longer operations and have a BMI≥25kg/m2. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Sacral Insufficiency Fracture Following Short-Segment Lumbosacral Fusion: Case Series and Review of the Literature.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Sacral insufficiency fracture is a rare and serious complication following lumbar spine instrumented fusion. The purpose of this study was to describe the patient characteristics, presentation, evaluation, treatment options, and outcomes for patients with sacral insufficiency fracture after short-segment lumbosacral fusion. METHODS: Six patients from our institutional database and 16 patients from literature review were identified with a sacral insufficiency fracture after short-segment (L4-S1 or L5-S1) lumbar fusion within 1 year of surgery. RESULTS: Patients were 55% female with a mean age of 58 years and body mass index of 30 kg/m2. Osteoporosis or osteopenia was the most common comorbidity (85%). Half of patients sustained a sacral fracture after surgery from a posterior approach, while the others had anterior or anterior-posterior surgery. Mean time to fracture was 42 days with patients clinically presenting with new sacral pain (86%), radiculopathy (60%), or neurologic deficit (5%). Ultimately, 73% of patients underwent operative fixation often involving extension of the construct (75%) and fusion to the pelvis (69%). Men (P = .02) and patients with new radicular pain or neurologic deficit (P = .01) were more likely to undergo revision surgical treatment while women over 50 years of age were more likely to be treated conservatively (P = .003). CONCLUSIONS: Spine surgeons should monitor for sacral insufficiency fracture as a source of new-onset pain in the postoperative period in patients with a short segment fusion to the sacrum. The recognition of this complication should prompt an assessment of bone health and management of underlying bone fragility.

Analysis of patient characteristics and outcomes related to distance traveled to a tertiary center for primary reverse shoulder arthroplasty.

INTRODUCTION: The reasons for referral and travel patterns are lacking for patients undergoing reverse shoulder arthroplasty (RSA). The purpose of this study was to compare comorbidities, surgical time, cost and complications between local and distant primary RSA patients. METHODS: Between 2007 and 2015, 1,666 primary RSAs were performed at our institution. Patients were divided into two cohorts, local patients (from within Olmstead county and surrounding counties, 492 RSAs) and those from a distance (1,174 RSAs). RESULTS: Local patients were older (74 vs 71 years, p < .001), more likely to have RSA for fracture, had a higher Charlson comorbidity score (3.8 vs 3.2, p < .001) and longer hospital stays (2.0 vs 1.8 days, p < 0.001) compared to referred patients. Referral patients required longer operative times (95 vs 88 min, p = .002), had higher hospitalization costs ($19,101 vs $18,735, p < .001), and had a higher rate of prior surgery (32% vs 24%, p < .001). There were no differences between cohorts regarding complications or need for reoperation. CONCLUSIONS: Patients traveling from a distance to undergo primary RSA had longer operative times and were more likely to have had prior surgery than local patients. This may demonstrate the referral bias seen at large academic centers and should be considered when reviewing RSA outcomes, hospital performance, and calculating insurance reimbursement. LEVEL OF EVIDENCE: Level IV.

Ergonomics in Spine Surgery.

As physician burnout and wellness become increasingly recognized as vital themes for the medical community to address, the topic of chronic work-related conditions in surgeons must be further evaluated. While improving ergonomics and occupational health have been long emphasized in the executive and business worlds, particularly in relation to company morale and productivity, information within the surgical community remains relatively scarce. Chronic peripheral nerve compression syndromes, hand osteoarthritis, cervicalgia and back pain, as well as other repetitive musculoskeletal ailments affect many spinal surgeons. The use of ergonomic training programs, an operating microscope or exoscope, powered instruments for pedicle screw placement, pneumatic Kerrison punches and ultrasonic osteotomes, as well as utilizing multiple surgeons or microbreaks for larger cases comprise several methods by which spinal surgeons can potentially improve workspace health. As such, it is worthwhile exploring these areas to potentially improve operating room ergonomics and overall surgeon longevity.

Lymphedema Is a Significant Risk Factor for Failure After Primary Total Hip Arthroplasty.

BACKGROUND: Lymphedema is a chronic disease characterized by fluid buildup and swelling that can lead to skin and soft-tissue fibrosis and recurring soft-tissue infections. Literature with regard to the increased risk of complications following a surgical procedure in patients with lymphedema is emerging, but the impact of lymphedema in the setting of primary total hip arthroplasty (THA) remains unknown. The purpose of this study was to review outcomes following primary THA performed in patients with lymphedema compared with a matched cohort without lymphedema. METHODS: Using our institutional total joint registry and medical records, we identified 83 patients (57 were female and 26 were male) who underwent THA with ipsilateral lymphedema. For comparison, these patients were matched 1:6 (based on sex, age, date of the surgical procedure, and body mass index [BMI]) to a group of 498 patients without lymphedema who underwent primary THA for osteoarthritis. Subsequently, postoperative complications and implant survivorship were evaluated for each group. The mean follow-up for each group was 6 years. Survivorship was compared between cohorts using Kaplan-Meier methodology and included both survivorship free of infection and survivorship free of reoperation or revision. Univariate Cox regression analysis was utilized to assess the association between patient factors for the time to event outcomes noted above. RESULTS: In patients with a history of lymphedema, there was an increased risk of complications (hazard ratio [HR], 1.97; p < 0.01), including reoperation for any cause (HR, 3.16; p < 0.01) and postoperative infection (HR, 4.48; p < 0.01). The 5-year infection-free survival rate was 90.3% for patients with lymphedema compared with 97.7% for patients without lymphedema (p < 0.01). CONCLUSIONS: Patients with lymphedema are at increased risk for complications, including reoperation and infection, following primary THA. These data emphasize the importance of appropriate preoperative counseling in this population and should encourage efforts to identify methods to improve outcomes, including further investigation of the effects of preoperative optimization of lymphedema prior to THA and methods for improved perioperative management. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Value of Cement Augmentation in Patients With Diminished Bone Quality Undergoing Thoracolumbar Fusion Surgery: A Review.

STUDY DESIGN: Systematic review. OBJECTIVES: Osteoporosis predisposes patients undergoing thoracolumbar (TL) fusion to complications and revision surgery. Cement augmentation (CA) improves fixation of pedicle screws to reduce these complications. The goal of this study was to determine the value and cost-effectiveness of CA in TL fusion surgery. METHODS: A systematic literature review was performed using an electronic database search to identify articles discussing the cost or value of CA. As limited information was available, the review was expanded to determine the mean cost of primary TL fusion, revision TL fusion, and the prevalence of revision TL fusion to determine the decrease of revision surgery necessary to make CA cost-effective. RESULTS: Two studies were identified discussing the cost and value of CA. The mean cost of CA for two vertebral levels was $10 508, while primary TL fusion was $87 346 and revision TL fusion was $76 825. Using a mean revision rate of 15.4%, the use of CA for TL fusion would need to decrease revision rates by 13.7% to be cost-effective. Comparison studies showed a decreased revision rate of 11.3% with CA, which approaches this value. CONCLUSION: CA for TL fusion surgery improves biomechanical fixation of pedicle screws and decreases complications and revision surgery in patients with diminished bone quality. The costs of CA are substantial and reported decreases in revision rates approach but do not reach the calculated value to be a cost-effective technique. Future studies will need to focus on the optimal CA technique to decrease complications, revisions, and costs.

Surgical treatment of primary mobile spine chordoma.

BACKGROUND AND OBJECTIVES: Chordomas of the mobile spine (C1-L5) are rare malignant tumors. The purpose of this study was to review the outcome of surgical treatment for patients with primary mobile spine chordomas. METHODS: The oncologic outcomes and survival of 26 patients undergoing surgical resection for a primary mobile spine chordoma were assessed over a 25-year period. The mean follow-up was 12 ± 6 years. RESULTS: The 2-, 5-, and 10-year disease-free survivals were 95%, 61%, and 55%. The local recurrence-free survival was improved in patients receiving en bloc resection with negative margins (83% vs. 35%, p = 0.02) and similar in patients receiving adjuvant radiation therapy (43% vs. 45%, p = 0.30) at 10 years. Debulking of the tumor (hazard ratio [HR] = 6.41, p = 0.01) and a local recurrence (HR = 9.52, p = 0.005) were associated with death due to disease. Complications occurred in 19 (73%) patients, leading to reoperation in 9 (35%) patients; this rate was similar in intralesional and en bloc procedures. CONCLUSION: Surgical resection of mobile spine chordomas is associated with a high rate of complications; however, en bloc resection can provide a hope for cure and appears to confer better oncologic outcomes for these tumors without an increase in complications compared to lesser resections.

Anterior Cervical Osteophyte Resection for Treatment of Dysphagia.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVES: When anterior cervical osteophytes become large enough, they may cause dysphagia. There is a paucity of work examining outcomes and complications of anterior cervical osteophyte resection for dysphagia. METHODS: Retrospective review identified 19 patients who underwent anterior cervical osteophyte resection for a diagnosis of dysphagia. The mean age was 71 years and follow-up, 4.7 years. The most common level operated on was C3-C4 (13, 69%). RESULTS: Following anterior cervical osteophyte resection, 79% of patients had improvement in dysphagia. Five patients underwent cervical fusion; there were no episodes of delayed or iatrogenic instability requiring fusion. Fusion patients were younger (64 vs 71 years, P = .05) and had longer operative times (315 vs 121 minutes, P = .01). Age of 75 years or less trended toward improvement in dysphagia (P = .09; OR = 18.8; 95% CI 0.7-478.0), whereas severe dysphagia trended toward increased complications (P = .07; OR = 11.3; 95% CI = 0.8-158.5). Body mass index, use of an exposure surgeon, diffuse idiopathic skeletal hyperostosis diagnosis, surgery at 3 or more levels, prior neck surgery, and fusion were not predictive of improvement or complication. CONCLUSIONS: Anterior cervical osteophyte resection improves swallowing function in the majority of patients with symptomatic osteophytes. Spinal fusion can be added to address stenosis and other underlying cervical disease and help prevent osteophyte recurrence, whereas intraoperative navigation can be used to ensure complete osteophyte resection without breaching the cortex or entering the disc space. Because of the relatively high complication rate, patients should undergo thorough multidisciplinary workup with swallow evaluation to confirm that anterior cervical osteophytes are the primary cause of dysphagia prior to surgery.

Lymphedema: A Significant Risk Factor for Infection and Implant Failure After Total Knee Arthroplasty.

BACKGROUND: Lymphedema is characterized by fluid buildup and swelling, leading to skin fibrosis and recurring soft-tissue infections. There is a paucity of data examining the impact of lymphedema in total knee arthroplasty (TKA). The purpose of this study was to review the outcomes of TKA in patients with lymphedema compared with a matched cohort with primary osteoarthritis. METHODS: One hundred forty-four knees underwent primary TKA with a preceding diagnosis of ipsilateral lymphedema. The mean follow-up was 7 years. A blinded 1:2 match of knees with lymphedema to a group of knees without lymphedema undergoing primary TKA was performed. Matching criteria included sex, age, date of surgery, and body mass index. The mean follow-up for the comparison cohort was 8 years. RESULTS: Lymphedema increased revision hazard ratio [HR] 7.60; P < 0.001), reoperation (HR, 2.87; P < 0.001), and infection (HR, 6.19; P < 0.001) in addition to periprosthetic fracture (P = 0.04) and tibial component loosening (P = 0.01). The mean time to infection trended toward later time points in knees with lymphedema (19 versus 2 months, P = 0.25). DISCUSSION: Lymphedema increased the risk of revision, reoperation, and infection. These data highlight the need for appropriate patient counseling and the need for further investigation into the effects of preoperative and postoperative optimization of lymphedema management in the TKA setting. LEVEL OF EVIDENCE: Therapeutic Level III.

Total Knee Arthroplasty After Intramedullary Tibial Nail: A Matched Cohort Study.

BACKGROUND: As the use of intramedullary nails (IMNs) has become more common, there are an increasing number of patients requiring total knee arthroplasty (TKA) who have an indwelling tibial IMN. The purpose of this study is to compare implant survivorship, clinical outcomes, and complications in patients undergoing primary TKA with a history of tibial IMN to those without. METHODS: We retrospectively identified 24 TKAs performed between 2000 and 2017 after ipsilateral tibial IMN. Patients were matched 1:2 to patients undergoing primary TKA without history of tibial IMN based upon age, gender, body mass index, and year of surgery. Mean follow-up was 7 years. RESULTS: The 10-year survivorship free of any revision was 100% for the tibial IMN cohort, and 96% for the control cohort, while the 10-year survivorship free of any reoperation was 91% and 89%, respectively (P = .72). Patients with a history of tibial IMN had similar Knee Society Scores to matched controls at 2 years (P = .77) and 5 years (P = .09). Acquired idiopathic stiffness trended toward being more common (17% vs 6%, P = .21) and operative time trended toward being longer (135 vs 118 min, P = .07) when the tibial IMN was removed, but there was no overall difference in complication rate between cohorts. CONCLUSIONS: To our knowledge, this is the first report of primary TKA in patients with a history of ipsilateral tibial IMN. Compared to a matched cohort of patients without tibial IMN, these patients have similar outcomes in regards to implant survivorship, clinical outcomes, and risk of complications. LEVEL OF EVIDENCE: Therapeutic Level III.

Symptomatic Thromboembolic Complications After Shoulder Arthroplasty: An Update.

BACKGROUND: Venous thromboembolism (VTE) complications, including deep vein thrombosis and pulmonary embolism, are dreaded complications of orthopaedic surgical procedures that can result in substantial morbidity and mortality. There is a paucity of data examining risk factors for VTE in shoulder arthroplasty. The purpose of the present study was to review the rate of symptomatic VTE, determine patient and operative risk factors for VTE, and report on complications associated with VTE following shoulder arthroplasty. METHODS: Over a 16-year period, 5,906 patients underwent primary anatomic total shoulder arthroplasty, reverse total shoulder arthroplasty, or hemiarthroplasty. Symptomatic VTE events were identified in 24 shoulders within 90 days of surgery. Patient records were reviewed for surgical indication, patient and operative risk factors, and management of VTE. RESULTS: The rate of symptomatic VTE following shoulder arthroplasty was 0.41%. There were no deaths resulting from VTE events. Compared with patients who did not have VTE, those with symptomatic VTE events were found to be older (74.75 versus 68.51 years; p = 0.0028) and more likely to have had arthroplasty for a traumatic indication (3.31% versus 0.33%; p < 0.001). Age of >70 years and arthroplasty for a traumatic indication were found to be independent risk factors on multivariate nominal logistic regression analysis, whereas body mass index, sex, operative time, and type of arthroplasty performed were not found to be independent risk factors. There were 11 readmissions resulting directly from the VTE events, and patients diagnosed with VTE as inpatients had longer hospital stays than outpatients (13.71 versus 1.94 days; p = 0.0002). CONCLUSIONS: The risk of VTE following shoulder arthroplasty is low, and routine use of pharmacologic VTE prophylaxis may not be necessary. However, VTE complications can lead to substantial morbidity, longer hospital stays, readmission to the hospital, and further complications. Therefore, patients with multiple risk factors for VTE such as prior history of VTE, active malignancy, age of >70 years, or arthroplasty for traumatic indications should be considered for pharmacologic VTE prophylaxis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Efficient generation of functional epithelial and epidermal cells from human pluripotent stem cells under defined conditions.

Human pluripotent stem cells (hPSCs) have an unparalleled potential to generate limitless quantities of any somatic cell type. However, current methods for producing populations of various somatic cell types from hPSCs are generally not standardized and typically incorporate undefined cell culture components often resulting in variable differentiation efficiencies and poor reproducibility. To address this, we have developed a defined approach for generating epithelial progenitor and epidermal cells from hPSCs. In doing so, we have identified an optimal starting cell density to maximize yield and maintain high purity of K18+/p63+ simple epithelial progenitors. In addition, we have shown that the use of synthetic, defined substrates in lieu of Matrigel and gelatin can successfully facilitate efficient epithelial differentiation, maintaining a high (>75%) purity of K14+/p63+ keratinocyte progenitor cells and at a two to threefold higher yield than a previously reported undefined differentiation method. These K14+/p63+ cells also exhibited a higher expansion potential compared to cells generated using an undefined differentiation protocol and were able to terminally differentiate and recapitulate an epidermal tissue architecture in vitro. In summary, we have demonstrated the production of populations of functional epithelial and epidermal cells from multiple hPSC lines using a new, completely defined differentiation strategy.