A Comparison of Outcomes in Acute Perilunate Injuries: Systematic Review and Meta-Analysis of Treatment Approaches.

BACKGROUND: Perilunate dislocations (PLD) and fracture-dislocations (PLFD) comprise a spectrum of high-energy wrist injuries. The purpose of this review was to review operative strategies for perilunate injuries based on approach and compare outcomes. METHODS: A systematic review of literature on PLD and fracture-dislocations was carried out according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed and EMBASE databases were queried for literature. Inclusion criteria included English studies reporting clinical or functional outcomes of acute PLD and PLFD. RESULTS: Twenty-nine full-text articles (604 PLD and PLFD injuries) were included. The most common method of PLD and PLFD fixation is through an open approach with combined volar and dorsal exposure. There were no differences between approaches with regard to total arc range of motion, grip strength, Mayo Wrist Score, or mean scapholunate angle. Similarly, there was no difference between approaches and postoperative radiographic arthritis or complications. Most patients were able to return to their prior level of function and work. The incidence of postoperative complications ranged from 0% to 22.5%. CONCLUSION: Current evidence shows no difference in postoperative total wrist arc range of motion, grip strength (as compared to contralateral), or Mayo Wrist Score with regard to surgical approach. The most common method of PLD and PLFD fixation in the literature is through an open approach with combined volar and dorsal exposure. There is a large difference in reported rates of radiographic arthritis, although this finding does not appear to correlate with postoperative pain or disability. LEVEL OF EVIDENCE: I, Systematic Review.

Cement Burn of the Skin Following Total Knee Arthroplasty Case Report and Review of the Literature.

INTRODUCTION: Cement burns following arthroplasty pro-cedures are a rare but serious complication. To the authors' knowledge, this report is the first of its kind in total knee arthroplasty. CASE: A 61-year-old female underwent an otherwise rou-tine left total knee arthroplasty. On postoperative day one, a 3 cm by 3 cm cement burn was noted on the distal aspect of the popliteal fossa of the operative leg. The burn was noted to be a full-thickness (third degree) burn that required plastic surgery burn service management and limited the patient's postoperative recovery and function. CONCLUSIONS: Cement burns of the skin following total joint arthroplasty are rare, though when they do occur, they can cause significant pain and distress. Recognizing the depth of the skin involvement is important to determine the burn classification, treatment, and ultimately the prognosis to optimize outcomes.

"Reverse roussouly": cervicothoracic curvature ratios define characteristic shapes in adult cervical deformity.

PURPOSE: To investigate normal curvature ratios of the cervicothoracic spine and to establish radiographic thresholds for severe myelopathy and disability, within the context of shape. METHODS: Adult cervical deformity (CD) patients undergoing cervical fusion were included. C2-C7 Cobb angle (CL) and thoracic kyphosis (TK), using T2-T12 Cobb angle, were used as a ratio, ranging from -1 to + 1. Pearson bivariate r and univariate analyses analyzed radiographic correlations and differences in myelopathy(mJOA > 14) or disability(NDI > 40) across ratio groups. RESULTS: Sixty-three CD patients included. Regarding CL:TK ratio, 37 patients had a negative ratio and 26 patients had a positive ratio. A more positive CL:TK correlated with increased TS-CL(r = 0.655, p = < 0.001)and mJOA(r = 0.530, p = 0.001), but did not correlate with cSVA/SVA or NDI scores. A positive CL:TK ratio was associated with moderate disability(NDI > 40)(OR: 7.97[1.22-52.1], p = 0.030). Regression controlling for CL:TK ratio revealed cSVA > 25 mm increased the odds of moderate to severe myelopathy and cSVA > 30 mm increased the odds of significant neck disability. Lastly, TS-CL > 29 degrees increased the odds of neck disability by 4.1 × with no cutoffs for severe mJOA(p > 0.05). CONCLUSIONS: Cervical deformity patients with an increased CL:TK ratio had higher rates of moderate neck disability at baseline, while patients with a negative ratio had higher rates of moderate myelopathy clinically. Specific thresholds for cSVA and TS-CL predicted severe myelopathy or neck disability scores, regardless of baseline neck shape. A thorough evaluation of the cervical spine should include exploration of relationships with the thoracic spine and may better allow spine surgeons to characterize shapes and curves in cervical deformity patients.

Interfacet distance at L4 is increased in spines with high-pelvic incidence.

Pelvic incidence (PI) is an angular measurement linked to spinal pathologies. There is an increasing distance between facet joints moving caudally down the sagittal plane of the spine. We defined pedicle divergence (PD) as the ratio of interfacet distance (IFD) between adjacent levels. This study aimed to evaluate the relationship between PI and PD. Two hundred and thirty specimens were obtained from the Hamann-Todd Osteological Collection. Specimens were catalogued for age, sex, race, PI, PD, and lumbar facet angle. Multivariate linear regression analysis was performed to determine the relationship between variables. IRB approval was not required. Average age at death was 57.0 years ±6.2 years. There were 211 (92%) male specimens and 176 (77%) were white. Average PI was 47.1 ± 10.5°. For PD between L3/L4, there was a relationship with PI (ß = -0.18, p = 0.008). For PD between L4/L5, there was an opposite relationship with PI (ß = 0.21, p = 0.003). Regression analyses of the interfacet to body ratio at each level found an association with PI only at L4 (p = 0.008). This study demonstrated that PI has a significant association with IFD in the lower lumbar spine. Increasing PI was associated with increased PD between L3/L4 and decreased PD between L4/L5. These results further support the close relationship between pelvic morphology and the lower lumbar spine, and suggest that L4 may have an important role in compensating for aberrant PI.

Treatment Outcomes in American Football Players After Intervertebral Disk Herniation: Systematic Review and Meta-Analysis.

BACKGROUND: American football players are at increased risk for many forms of spinal injury. Intervertebral disk herniations are particularly concerning as they are the leading cause of days lost to injury and can have long-term effects on player careers. Disk herniation management plays a major role in the likelihood and success of return-to-play (RTP). OBJECTIVE: To assess the incidence, demographic variables, treatment approaches, outcomes, and RTP rates of disk herniations in American football players. METHODS: A systematic review of the literature investigating disk herniations in American football players using PubMed, Cochrane Library, and Embase was performed. RTP estimates were calculated by pooling study-specific data using a random-effects model. RESULTS: Four hundred twenty-two studies were identified, with 18 meeting inclusion criteria. Offensive and defensive linemen were the 2 most commonly injured positions. Players undergoing operations were on average younger, with higher body mass indexes, fewer seasons played, and longer post-treatment careers than nonsurgical counterparts. Postsurgical recovery periods lasted an average 106 d, with a mean RTP duration of 33 games over 2.7 yr and an 8.45% reoperation rate. Operative treatment offered a nonsignificant increase in the likelihood of return-to-play compared with nonoperative treatment (odds ratio = 2.81, 95% CI 0.83-9.51). CONCLUSION: Disk herniations are a common injury, with surgery potentially improving post-treatment outcomes. The literature suffers from heterogeneous definitions of RTP and varying performance metrics, making it difficult to draw clear conclusions. To better understand the impact of disk herniation and treatment on player health and performance, more studies should be performed prospectively and with standardized metrics.

Unicompartmental Knee Arthroplasty in Octogenarians versus Younger Patients: A Comparison of 30-Day Outcomes.

As the United States' octogenarian population (persons 80-89 years of age) continues to grow, understanding the risk profile of surgical procedures in elderly patients becomes increasingly important. The purpose of this study was to compare 30-day outcomes following unicompartmental knee arthroplasty (UKA) in octogenarians with those in younger patients. The American College of Surgeons National Surgical Quality Improvement Program database was queried. All patients, aged 60 to 89 years, who underwent UKA from 2005 to 2016 were included. Patients were stratified by age: 60 to 69 (Group 1), 70 to 79 (Group 2), and 80 to 89 years (Group 3). Multivariate regression models were estimated for the outcomes of hospital length of stay (LOS), nonhome discharge, morbidity, reoperation, and readmission within 30 days following UKA. A total of 5,352 patients met inclusion criteria. Group 1 status was associated with a 0.41-day shorter average adjusted LOS (99.5% confidence interval [CI]: 0.67-0.16 days shorter, p < 0.001) relative to Group 3. Group 2 status was not associated with a significantly shorter LOS compared with Group 3. Both Group 1 (odds ratio [OR] = 0.15, 99.5% CI: 0.10-0.23) and Group 2 (OR = 0.33, 99.5% CI: 0.22-0.49) demonstrated significantly lower adjusted odds of nonhome discharge following UKA compared with Group 3. There was no significant difference in adjusted odds of 30-day morbidity, readmission, or reoperation when comparing Group 3 patients with Group 1 or Group 2. While differences in LOS and nonhome discharge were seen, octogenarian status was not associated with increased adjusted odds of 30-day morbidity, readmission, or reoperation. Factors other than age may better predict postoperative complications following UKA.

Symptomatic Epidural Hematoma After Elective Cervical Spine Surgery: Incidence, Timing, Risk Factors, and Associated Complications.

BACKGROUND: As the rate of elective cervical spine surgery increases, studies of complications may improve quality of care. Symptomatic postoperative cervical epidural hematomas (PCEH) are rare but result in significant morbidity. Because of their low incidence, the risk factors and complications associated with symptomatic PCEH remain unclear. OBJECTIVE: To clarify the prevalence, timing, variables, and complications associated with PCEH following elective cervical spine surgery. METHODS: Using the American College of Surgeons National Surgical Quality Improvement Program database, cervical spine surgeries performed between 2012 and 2016 were identified using Current Procedural Terminology codes. Symptomatic PCEH was defined as readmission or reoperation events specifically associated with International Classification of Diseases code diagnoses of postoperative hematoma within 30 d of index surgery. Multivariate models were created to assess the independent association of symptomatic PCEH with other postoperative complications. RESULTS: There were 53233 patients included for analysis. The overall incidence of symptomatic PCEH was 0.4% (n = 198). Reoperation occurred in 158 cases (78.8%), of which 2 required a second reoperation (1.3%). The majority (91.8%) of hematomas occurred within 15 d of surgery. Multivariate analysis identified male gender, American Society of Anesthesiologists classes 3 to 5, bleeding disorder, increasing number of operative levels, revision surgery, dural repair, and perioperative transfusion as independent factors associated with PCEH. Upon controlling for those confounders, PCEH was independently associated with cardiac arrest, stroke, deep vein thrombosis, surgical site infection, and pneumonia. CONCLUSION: Postoperative epidural hematomas requiring readmission or reoperation following elective cervical spine surgery occurred at an incidence of 0.4%. Symptomatic PCEHs are associated with increased rates of numerous major morbidities.

Postoperative Prophylactic Antibiotics in Spine Surgery: A Propensity-Matched Analysis.

BACKGROUND: Surgical site infections are common and costly complications after spine surgery. Prophylactic antibiotics are the standard of care; however, the appropriate duration of antibiotics has yet to be adequately addressed. We sought to determine whether the duration of antibiotic administration (preoperatively only versus preoperatively and for 24 hours postoperatively) impacts postoperative infection rates. METHODS: All patients undergoing inpatient spinal procedures at a single institution from 2011 to 2018 were evaluated for inclusion. A minimum of 1 year of follow-up was used to adequately capture postoperative infections. The 1:1 nearest-neighbor propensity score matching technique was used between patients who did and did not receive postoperative antibiotics, and multivariable logistic regression analysis was conducted to control for confounding. RESULTS: A total of 4,454 patients were evaluated and, of those, 2,672 (60%) received 24 hours of postoperative antibiotics and 1,782 (40%) received no postoperative antibiotics. After propensity-matched analysis, there was no difference between patients who received postoperative antibiotics and those who did not in terms of the infection rate (1.8% compared with 1.5%). No significant decrease in the odds of postoperative infection was noted in association with the use of postoperative antibiotics (odds ratio = 1.17; 95% confidence interval, 0.620 to 2.23; p = 0.628). Additionally, there was no observed increase in the risk of Clostridium difficile infection or in the short-term rate of infection with multidrug-resistant organisms. CONCLUSIONS: There was no difference in the rate of surgical site infections between patients who received 24 hours of postoperative antibiotics and those who did not. Additionally, we found no observable risks, such as more antibiotic-resistant infections and C. difficile infections, with prolonged antibiotic use. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is Timing to Surgery an Independent Risk Factor for Complications Following Operative Treatment of Periprosthetic Lower Extremity Fractures?

OBJECTIVE: To identify whether timing to surgery was related to major 30-day morbidity and mortality rates in periprosthetic hip and knee fractures [OTA/AO 3 (IV.3, V.3), OTA/AO 4 (V4)]. DESIGN: Retrospective database review. SETTING: Hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. PATIENTS: Patients in the NSQIP database with periprosthetic hip or knee fractures between 2007 and 2015. INTERVENTION: Surgical management of periprosthetic hip and knee fractures including revision or open reduction internal fixation. MAIN OUTCOME MEASUREMENTS: Major 30-day morbidity and mortality after operative treatment of periprosthetic hip or knee fractures. RESULTS: A total of 1265 patients, mean age 72, including 883 periprosthetic hip and 382 periprosthetic fractures about the knee were reviewed. Delay in surgery greater than 72 hours is a risk factor for increased 30-day morbidity in periprosthetic hip and knee fractures [relative risk = 2.90 (95% confidence interval: 1.74-4.71); P-value ≤ 0.001] and risk factor for increased 30-day mortality [relative risk = 8.98 (95% confidence interval: 2.14-37.74); P-value = 0.003]. CONCLUSIONS: Using NSQIP database to analyze periprosthetic hip and knee fractures, delay to surgery is an independent risk factor for increased 30-day major morbidity and mortality when controlling for patient functional status and comorbidities. Although patient optimization and surgical planning are paramount, minimizing extended delays to surgery is a potentially modifiable risk factor in the geriatric periprosthetic lower extremity fracture patient. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Incremental Cost of Inpatient Venous Thromboembolism After Hip Fracture Surgery.

OBJECTIVES: To (1) identify trends in the rates of deep venous thrombosis (DVT) and pulmonary embolism (PE) and (2) calculate the additional incremental inpatient cost and length of stay associated with venous thromboembolism (VTE) after hip fracture surgery. DESIGN: Retrospective database analysis. SETTING: Hospital discharge data. PATIENTS/PARTICIPANTS: A total of 838,054 patients undergoing operative treatment of hip fractures in the National Inpatient Sample from 2003 to 2014. INTERVENTION: Internal fixation or partial/total hip replacement. MAIN OUTCOME MEASURES: The length of stay and cost of hospitalization were compared between patients with VTE and those without using a Student t-test. A logistic regression model was performed to evaluate the trends in VTE rates, and a multivariable linear regression model was performed to evaluate inpatient hospital costs. RESULTS: The overall rates of DVT and PE were 0.3% and 0.53%, respectively. VTE was associated with an increased length of stay (9 days vs. 5 days) and increased inpatient cost ($103,860.83 vs. $51,576.00). The rate of DVT over the study period decreased, whereas the rate of PE increased. CONCLUSIONS: Each episode of VTE after hip fracture is a significant source of additional inpatient cost. Patients who sustain a VTE have approximately twice the length of stay and total inpatient cost compared with those who do not. The rates of DVT after hip fracture surgery are decreasing, whereas the rates of PE are increasing. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pelvic Incidence in Spines With 4 and 6 Lumbar Vertebrae.

STUDY DESIGN: Anatomical study. OBJECTIVES: This study was conducted to determine the prevalence of abnormal lumbar vertebrae (4 and 6) and note any differences in pelvic incidence (PI) between spines with 4, 5, and 6 lumbar vertebrae. METHODS: We screened 2980 dry cadaveric specimens from an osteological collection. Pelvises were reconstructed by articulating the sacra and innominate bones. PI was measured in all specimens via lateral photographs. L6-pelvic incidence (L6PI) was also measured, by articulating L6 to the sacrum and measuring PI from the superior aspect of the L6 vertebral body. RESULTS: Of the specimens screened, 969 specimens were evaluated. Average age of death for all specimens was 50.4 ± 15.4 years. The prevalence of 6 lumbar vertebrae was 0.8% (n = 23), and the prevalence of 4 lumbar vertebrae was 1.8% (n = 54). PI measured 38.5° in specimens with 4 lumbar vertebrae, and 46.7° and 47.1° in specimens with 5 and 6 lumbar vertebrae, respectively. PI was significantly different between specimens with 4 and 5 lumbar vertebrae (P < .001) but not between specimens with 5 and 6 lumbar vertebrae (P = .38). For specimens with 6 lumbar vertebrae, when L6 was added to the sacrum, mean L6PI was 27.4°. CONCLUSIONS: In our large cadaveric study of full spines, we reported a lower prevalence of spines with 4 and 6 lumbar vertebrae compared to previous studies. PI was significantly decreased in subjects with 4 lumbar vertebrae compared with those with normal spines, and special caution should be taken when managing sagittal balance in these patients.

Correlation between the distance from the pubic symphysis to the sacrum with pelvic incidence.

INTRODUCTION: The distance between the pubic symphysis and sacrococcygeal joint has been noted as an important parameter in evaluating pelvic tilt in an anteroposterior (AP) radiograph. Similarly, pelvic incidence measures the sagittal balance of the pelvis and is influenced by pelvic rotation. The relationship between these 2 parameters is unknown and could affect interpretation of pelvic AP radiographs. METHODS: We reconstructed 248 cadaveric pelvises. Pelvic incidence was measured using a previously validated method. Pubic symphysis-sacrococcygeal joint (PSS) height was measured from the superior pubic tubercle to the sacrococcygeal joint. The pelvises were positioned so that the anterior pelvis lay flush with the surface. A ruler was zeroed on the pubic tubercles and a transverse projecting laser was used to measure the height to the sacrococcygeal joint. RESULTS: A total of 248 pelvises were reconstructed. Average age of death of the specimens was 33±6.0 years. 80% of the pelvises were male, 56% were Caucasian, and 44% African American. The mean PSS height was 2.2 ± 1.4 cm and mean PI was 44.3° ± 10.6°. Multiple regression analysis found PI and PSS height were not correlated (p = 0.144). Females had a larger PSS height than males (beta = 1.17, p < 0.001) and African Americans a larger PSS height than Caucasians (beta = 0.63, p < 0.001). CONCLUSIONS: This study provides useful information for clinicians in evaluating AP radiographs of the pelvis in that it supports the use of PSS height to judge the adequacy of a radiograph even in the context of abnormal pelvic incidence.

Incidence of complete spinal instrumentation removal following surgery for spinal deformity: a 22-year single institution study.

The aim of this study was to define the incidence of complete implant removal following surgical correction of spinal deformity in pediatric patients over a 22-year period and identify possible risk factors. A retrospective review of our Pediatric Orthopedic Spine Database between 1992 and 2016 was performed. We included patients undergoing complete implant removal following scoliosis correction surgery with a minimum of 2-year follow-up. Medical charts were reviewed to determine initial patient diagnosis and the indication for implant removal. Statistical analysis was carried out to determine the associations between sex and factors such as primary diagnosis and indication for removal. A review of 1117 procedures in 1114 patients identified complete instrument removal in 52 (4.7%) patients (34 females and 18 males). Mean time to removal following surgery was 2.3 years (range: 0-5.9 years). Removal occurred in 24 of 548 (4.4%) patients with adolescent idiopathic scoliosis, four of 117 (3.4%) patients with juvenile idiopathic scoliosis, 11 of 287 (3.8%) patients with neuromuscular scoliosis, and three of 79 (3.8%) patients with syndromic scoliosis. Infection was the most common indication for complete implant removal [24 (46%) patients], followed by persistent pain [8 (15%) patients], and metal intolerance [8 (15%) patients]. There were two cases of early infection (<1 year following surgery) and 22 late infections (≥1 year following surgery). The overall 22-year incidence of complete implant removal following spinal correction surgery for scoliosis was 4.7%. Infection continues to be the most common indication, followed by pain and metal intolerance.

Preoperative Hyponatremia Is Associated with Reoperation and Prolonged Length of Hospital Stay following Total Knee Arthroplasty.

Hyponatremia is a risk factor for adverse surgical outcomes, but limited information is available on the prognosis of hyponatremic patients who undergo total knee arthroplasty (TKA). The purpose of this investigation was to compare the incidence of major morbidity (MM), 30-day readmission, 30-day reoperation, and length of hospital stay (LOS) between normonatremic and hypontremic TKA patients.The American College of Surgeons National Surgical Quality Improvement Program database was used to identify all primary TKA procedures. Hyponatremia was defined as <135 mEq/L and normonatremia as 135 to 145 mEq/L; hypernatremic patients (>145 mEq/L) were excluded. Multivariable logistic regression was used to determine the association between hyponatremia and outcomes after adjusting for demographics and comorbidities. An α level of 0.002 was used and calculated using the Bonferroni correction. Our final analysis included 88,103 patients of which 3,763 were hyponatremic and 84,340 were normonatremic preoperatively. In our multivariable models, hyponatremic patients did not have significantly higher odds of experiencing an MM (odds ratio [OR]: 1.05; 99% confidence interval [CI] 0.93-1.19) or readmission (OR: 1.12; 99% CI: 1-1.24). However, patients with hyponatremia did experience significantly greater odds for reoperation (OR: 1.24; 99% CI: 1.05-1.46) and longer hospital stay (OR: 1.15; 99% CI: 1.09-1.21). We found that hyponatremic patients undergoing TKA had increased odds of reoperation and prolonged hospital stay. Preoperative hyponatremia may be a modifiable risk factor for adverse outcomes in patients undergoing TKA, and additional prospective studies are warranted to determine whether preoperative correction of hyponatremia can prevent complications.

Differences in Cross-Sectional Intervertebral Foraminal Area From C3 to C7.

STUDY DESIGN: Anatomical comparative study. OBJECTIVES: Few studies have evaluated foraminal areas in the cervical spine without degenerative changes. The purpose of this study was to determine and compare the mean cross-sectional foraminal areas between the C3/4, C4/5, C5/6, and C6/7 levels while also analyzing specimens for differences between sexes and races. METHODS: We performed an anatomic study of the intervertebral foramen at 4 levels (C3/4, C4/5, C5/6, C6/7) in 100 skeletally mature osseous specimens. Specimens were selected to obtain equal number of African American and Caucasian males and females (n = 25/group) aged 20 to 40 years at time of death. Foramina were photographed bilaterally with and without a silicone rubber disc. The maximal vertical height and mid-sagittal width of each foramen were digitally measured and the areas were calculated using an ellipse as a model. RESULTS: The average age at death for all specimens was 30 ± 6 years. The mean cross-sectional area of the C4/5 foramen was significantly smaller compared with the C5/6 (P < .001). C5/6 was significantly narrower than C6/7 (P < .001) foramen with and without disc augmentation. C3/4 was not significantly different from more caudal levels. There was no difference between male and female specimens, while African Americans had smaller foraminal sizes than Caucasians. CONCLUSIONS: This study provides the largest anatomical reference of the cervical intervertebral foramen. In a mature spine without facet joint hypertrophy or osteophytic changes, the C4/5 foramen was narrower than C5/6, which was narrower than C6/7. Understanding the relative foraminal areas in the nonpathological cervical spine is crucial to understanding degenerative changes as well as the anatomical changes in pathologies that affect the intervertebral foramen.

Relationship Between Foraminal Area and Degenerative Changes in the Lower Cervical Spine With Implications for C5 Nerve Root Palsy.

Preoperative foraminal stenosis at C4/5 is a predisposing risk factor for C5 nerve root palsy in elderly patients. However, the area of the C4/5 intervertebral foramen and its relationship to the extent of arthrosis and lower foraminal areas (C5/6 and C6/7) are unknown. The authors sought to compare the areas of the cervical intervertebral foramen at the C4/5, C5/6, and C6/7 levels, noting any differences across race or sex and the relationship between foraminal area and arthrosis grade. A total of 600 cervical foramina from an osseous collection were examined. One hundred specimens between the ages of 60 and 80 years were selected, 50 from each sex and race (white and African American). Foramina were photographed bilaterally at C4/5, C5/6, and C6/7. Vertical height and mid-sagittal width were digitally measured. The degree of arthrosis within each intervertebral foramen was graded by 2 of the authors independently using the Kellgren-Lawrence grading system. Average age of death for specimens was 69.3±5.9 years. The mean foraminal areas at C4/5 (P=.001) and C5/6 (P<.001) were significantly smaller than at C6/7. Whites had larger foraminal areas than African Americans at C4/5 (P=.05) and C6/7 (P=.01). Arthrosis grade was found to make a significant contribution to foraminal area at C4/5 (standardized beta=-0.267; P<.001), but not at C5/6 or C6/7. A higher grade of arthrosis was associated with a narrower intervertebral foramen at the C4/5 level in osseous specimens from elderly individuals. [Orthopedics. 2018; 41(4):e506-e510.].

Pelvic Incidence Is Associated With Sacral Curvature, Sacroiliac Joint Angulation, and Sacral Ala Width.

STUDY DESIGN: Cross-sectional anatomical study in dry cadaveric specimens. OBJECTIVE: This study evaluates how the sacroiliac (SI) joint angulation, midsagittal sacral curvature, and sacral ala width relate to pelvic incidence (PI). SUMMARY OF BACKGROUND DATA: Numerous spinopelvic pathologies have been linked with pelvic incidence; however, the manner in which sacral morphology fits into this association is largely unknown. METHODS: A total of 120 cadaveric sacra and corresponding innominate bones were obtained from an osteological collection. Pelvic incidence was measured in a previously validated method. To gauge ala width, calipers were used to measure the distance between the midpoint of the sacral endplate and the anterolateral aspect of the right and left ala. Sacral curvature was evaluated by measuring the difference of the direct distance and the curved bony distance from the sacral promontory to the inferior aspect of the fourth intervertebral foramen. Three separate angle measurements were made to quantify the angulation of the SI joint, which we divided into an upper and lower limb. Angle 1 approximated the relationship between the upper limb and the sacral endplate; angle 2 between the upper and lower limbs; angle 3 between the lower limb and a tangential line to the fourth sacral foramen. RESULTS: Average age at death for all specimens was 31.9 ±â€Š6.3 years with 63% representation of males and an equal distribution of Caucasian and African Americans. The mean PI of our study population was 45.1 ±â€Š12.6°. Results from our regression showed statistically significant associations between our measured angles evaluating SI joint angulation (angles 1, 2, 3) and PI. Standardized beta for angle 1 was -0.421, angle 2 was 0.419, and angle 3 was -0.439 (all P < 0.001). Additionally, the average endplate-ala distance (beta = -0.254) and average difference between tape-caliper measurements, our measurement for sacral arc, (beta = 0.178) were significantly associated with PI (all P < 0.05). CONCLUSION: Our data supports the theory that increased PI is associated with a highly angulated and curved sacrum, with corresponding changes in the SI joint, and narrowed sacral alae. LEVEL OF EVIDENCE: N/A.

ABO Blood Group Is a Predictor for the Development of Venous Thromboembolism After Total Joint Arthroplasty.

BACKGROUND: The study's purpose was to determine if there is an association between ABO blood group and the development of symptomatic venous thromboembolism (VTE) after total joint arthroplasty (TJA). METHODS: A total of 28,025 patients who underwent primary TJA at a single health care system from 2000 to 2014 were retrospectively reviewed from electronic records. Patients who experienced a symptomatic VTE were identified. A multivariate regression model adjusted for known potential risk factors, including age, gender, body mass index, surgery type, previous VTE, smokers, rheumatologic diseases, malignancy, hypercoagulable state, and VTE prophylaxis, was developed to test the association of ABO blood group and postoperative VTE. Separate multivariate regressions were performed for total knee arthroplasty and total hip arthroplasty, specifically looking at pulmonary embolism. RESULTS: The risk of symptomatic VTE after TJA was increased in AB blood group patients (odds ratio = 1.4; P = .03). Furthermore, the risk of pulmonary embolism was increased after total knee arthroplasty in AB blood group patients (odds ratio = 2.24; P = .001) but not after total hip arthroplasty (P = .742). CONCLUSION: AB blood group increased the risk of VTE after TJA. Patient's ABO blood group should be considered in terms of risk stratification and selection of appropriate postoperative VTE prophylaxis.

Historical Perspective: Henry H. Bohlman (1937-2010): The Father of Contemporary Spine Surgery.

The incredible career of Henry H. Bohlman, MD, spanned over four decades at University Hospitals Case Medical Center. He was an innovator and pioneer, designing several techniques for the management of several spinal pathologies while advocating the anterior approach to the spine. Dr. Bohlman's legacy is preserved in his fellows who have become leaders in spine surgery throughout the world.