Effect of Posterior Glenoid Bone Loss and Retroversion on Arthroscopic Posterior Glenohumeral Stabilization.

BACKGROUND: Posterior glenohumeral instability is an increasingly recognized cause of shoulder instability, but little is known about the incidence or effect of posterior glenoid bone loss. PURPOSE: To determine the incidence, characteristics, and failure rate of posterior glenoid deficiency in shoulders undergoing isolated arthroscopic posterior shoulder stabilization. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients undergoing isolated posterior labral repair and glenoid-based capsulorrhaphy with suture anchors between 2008 and 2016 at a single institution were identified. Posterior bone deficiency was calculated per the best-fit circle method along the inferior two-thirds of the glenoid by 2 independent observers. Patients were divided into 2 groups: minimal (0%-13.5%) and moderate (>13.5%) posterior bone loss. The primary outcome was reoperation for any reason. The secondary outcomes were military separation and placement on permanent restricted duty attributed to the operative shoulder. RESULTS: A total of 66 shoulders met the inclusion criteria, with 10 going on to reoperation after a median follow-up of 16 months (range, 14-144 months). Of the total shoulders, 86% (57/66) had ≤13.5% bone loss and 14% (9/66) had >13.5%. Patients with moderate posterior glenoid bone loss had significantly greater retroversion (-11.5° vs -4.3°; P = .01). Clinical failure requiring reoperation was seen in 10.5% of patients in the minimal bone deficiency group and 44.4% in the moderate group (P = .024). There was no difference between groups in rate of military separation or restricted duty. Patients with moderate posterior glenoid bone deficiency were more likely to be experiencing instability instead of pain on initial presentation (P < .001), were more likely to have a positive Jerk test result (P = .05), and had increased glenoid retroversion (P = .01). CONCLUSION: In shoulders with moderate glenoid bone deficiency (>13.5%) and increased glenoid retroversion, posterior capsulolabral repair alone may result in higher reoperation rates than in shoulders without bone deficiency.

Risk Factors for Failure of Nonoperative Treatment of Posterior Shoulder Labral Tears on Magnetic Resonance Imaging.

INTRODUCTION: There are no reports in the literature describing risk factors for failure of nonoperative treatment of patients with posterior labral tears on magnetic resonance imaging (MRI). The purpose of this study is to identify risk factors for failure of nonoperative treatment in patients with an isolated posterior glenoid labral tear identified on MRI only. Patients with posterior labral tears on MRI who fail to improve with nonoperative treatment likely share a constellation of clinical history, physical exam, and radiographic findings. METHODS: One hundred and fifty-nine active duty military service members under the age of 40 with a posterior labral tear seen on MRI and who were clinically evaluated by a musculoskeletal trained physician were identified. We retrospectively evaluated their records ensuring a minimum of 2 years follow-up after MRI to identify surgical intervention for the posterior labral tear during this time period. Patients were stratified into two groups, those treated with any combination of nonoperative modalities and those treated with posterior labral repair surgery during the 2 years after the MRI. The electronic medical records were reviewed for clinical presentation and physical exam results. We measured multiple radiographic parameters, including glenoid version, size of the tear, and bone loss on MRI. Qualitative and quantitative data were compared between groups using Fisher's exact test and Student's t-test, respectively. This study was conducted under institutional review board approval. RESULTS: Of the 157 patients' shoulders in our study, 52% (n = 82) of patients with posterior labral tears underwent nonoperative treatment while 48% (n = 75) underwent surgery. The significant risk factors associated with surgery were a history of a specific injury, primary presenting complaint of instability, patient reported history of subluxation, inability to trust their shoulder with overhead activity, decreased strength with weight lifting, positive posterior load/shift exam, positive anterior apprehension, increased osseous glenoid retroversion, increased humeral head subluxation ratio, and anterior labral height (P < 0.05). Patients with a chief complaint of pain were much more likely to succeed with nonoperative treatment while those with instability underwent surgery more often. Ten (12.5%) of the surgical procedures included an anterior and posterior labral repair/stabilization procedure. CONCLUSION: Patients with an MRI confirmed posterior labral tear, which present with subjective complaints and physical exam maneuvers consistent with instability, appear less likely to be treated nonoperatively. Increased glenoid retroversion and posterior humeral head subluxation may also predispose patients toward surgical treatment. Additionally, posterior labral tears may extend into the anterior labrum more frequently than is recognized on MRI.

Early Pediatric Fractures in a Universally Insured Population within the United States.

BACKGROUND: Musculoskeletal injury, including fracture, is one of the most common causes of morbidity in pediatric patients. The purpose of this epidemiologic study is to determine the prevalence and risk factors for fracture in a large cohort of pediatric patients under the age of 5. RESULTS: Of the 233,869 patients included in the study, 13,698 fractures were identified in 10,889 patients. The highest annual incidence was in the 4 year old age group with a rate of 24.2 fractures per 1000 children. The annual incidence within all age groups was 11.7 fractures per 1000 children. The two most common fractures were forearm and humerus fractures. Fracture incidence was increased in male children, patients who live outside the US, and in Caucasian patients. An increase in rate of fracture was also identified in children of officers when compared with children of enlisted service members. There were 35 abuse related fractures in our cohort, with 19 of them occurring in children less than 1 year old. Only three children in our cohort had Osteogenesis Imperfecta. CONCLUSION: Fractures are common injuries in young children with an incidence over the first 5 years of life of 5.86%. Multiple risk factors were also identified including age, race, geographic location and socioeconomic status. The results of this study are an important contribution to epidemiologic and public health literature and serve to characterize the incidence of and risk factors for sustaining an early childhood fracture.

Prenatal use of medications for gastroesophageal reflux disease and early childhood fracture risk.

BACKGROUND: Gastroesophageal reflux disease is a common condition in pregnancy and is often managed with medications. Specific medications have been linked to osteoporosis and fragility fracture in older adults. This study assessed whether maternal use of antireflux medications is associated with early childhood fracture. METHODS: TRICARE beneficiaries during pregnancy were retrospectively identified using the Military Health System Data Repository and pharmacy data. Mother and infant data were linked; children with continuous enrollment for the first 5 years of life were included. Differences in the children's fracture risk were analyzed through multivariate analysis, adjusting for region, rank, and military branch of service. RESULTS: A total of 378 150 patients comprised the final cohort with 3.3% (n = 12 479) prescribed antireflux medications during pregnancy. A significant decrease in fracture rate was found among children of women who were prescribed antireflux medications during pregnancy compared with those who were not (0.8% vs 1.2%, RR = 0.70, 95% CI 0.58-0.85). There was no difference in fracture risk between histamine type 2 receptor antagonists and proton pump inhibitors. A significantly increased fracture incidence was seen in pregnancies with multiple gestations (RR = 1.38, 95% CI 1.04-1.85). There was no identified difference in fracture risk for women with gestational diabetes, preeclampsia, preterm or low birthweight, chronic hypertension, induction, or breech presentation when compared to women without these conditions. CONCLUSIONS: We found no increase in early childhood fracture risk with maternal antireflux medication use. This suggests that prenatal exposure to antireflux medications does not affect fetal bones to a clinically significant extent.

Proximal Femur Hounsfield Units on CT Colonoscopy Correlate With Dual-energy X-ray Absorptiometry.

BACKGROUND: Quantifying bone mineral density (BMD) on CT using commercial software demonstrates good-to-excellent correlations with dual-energy x-ray absorptiometry (DEXA) results. However, previous techniques to measure Hounsfield units (HUs) within the proximal femur demonstrate less successful correlation with DEXA results. An effective method of measuring HUs of the proximal femur from CT colonoscopy might allow for opportunistic osteoporosis screening. QUESTIONS/PURPOSES: (1) Do proximal femur HU measurements from CT colonoscopy correlate with proximal femur DEXA results? (2) How effective is our single HU measurement technique in estimating the likelihood of overall low BMD? (3) Does the relationship between our comprehensive HU measurement and DEXA results change based on age, sex, or time between studies? METHODS: This retrospective study investigated the measurement of HU of the femur obtained on CT colonoscopy studies compared with DEXA results. Between 2010 and 2017, five centers performed 9085 CT colonoscopy studies; of those, 277 (3%) also had available DEXA results and were included in this study, whereas 8809 (97%) were excluded for inadequate CT imaging, lack of DEXA screening, or lack of proximal femur DEXA results. The median number of days between CT colonoscopy and DEXA scan was 595 days; no patient was excluded based on time between scans because bone remodeling is a long-term process and this allowed subgroup analysis based on time between scans. Two reviewers performed HU measurements at four points within the proximal femur on the CT colonoscopy imaging and intraclass correlation coefficients were used to evaluate interrater reliability. We used Pearson correlation coefficients to compare the comprehensive (average of eight measurements) and a single HU measurement with each DEXA result-proximal femur BMD, proximal femur T-score, femoral neck BMD, and femoral neck T-score-to identify the best measurement technique within this study. Based on their lowest DEXA T-score, we stratified patients to a diagnosis of osteoporosis, osteopenia, or normal BMD. We then calculated the area under the receiver operator characteristic curves (AUCs) to evaluate the classification ability of a single HU value to identify possible threshold(s) for detecting low BMD. For each subgroup analysis, we calculated Pearson correlation coefficients between DEXA and HUs and evaluated each subgroup's contribution to the overall predictive model using an interaction test in a linear regression model. RESULTS: The Pearson correlation coefficient between both the comprehensive and single HU measurements was highest compared with the proximal femur T-score at 0.75 (95% confidence interval [CI], 0.69-0.80) and 0.74 (95% CI, 0.68-0.79), respectively. Interobserver reliability, measured with intraclass correlation coefficients, for the comprehensive and single HU measurements was 0.97 (95% CI, 0.72-0.99) and 0.96 (95% CI, 0.89-0.98), respectively. Based on DEXA results, 20 patients were osteoporotic, 167 had osteopenia, and 90 patients had normal BMD. The mean comprehensive HU for patients with osteoporosis was 70 ± 30 HUs; for patients with osteopenia, it was 110 ± 36 HUs; and for patients with normal BMD, it was 158 ± 43 HUs (p < 0.001). The AUC of the single HU model was 0.82 (95% CI, 0.77-0.87). A threshold of 214 HUs is 100% sensitive and 59 HUs is 100% specific to identify low BMD; a threshold of 113 HUs provided 73% sensitivity and 76% specificity. When stratified by decade age groups, each decade age group demonstrated a positive correlation between the comprehensive HU and proximal femur T-score, ranging between 0.71 and 0.83 (95% CI, 0.59-0.91). Further subgroup analysis similarly demonstrated a positive correlation between the comprehensive HU and proximal femur T-score when stratified by > 6 months or < 6 months between CT and DEXA (0.75; 95% CI, 0.62-0.84) as well as when stratified by sex (0.70-0.76; 95% CI, 0.48-0.81). The linear regression model demonstrated that the overall positive correlation coefficient between HUs and the proximal femur T-score is not influenced by any subgroup. CONCLUSIONS: Our measurement technique provides a reproducible measurement of HUs within the proximal femur HUs on CT colonoscopy. Hounsfield units of the proximal femur based on this technique can predict low BMD. These CT scans are frequently performed before initial DEXA scans are done and therefore may lead to earlier recognition of low BMD. Future research is needed to validate these results in larger studies and to determine if these results can anticipate future fracture risk. LEVEL OF EVIDENCE: Level III, diagnostic study.

The West Point Knot: A Sliding-Locking Arthroscopic Knot.

Despite the advent of sutureless technology, knot tying remains an important skill for any arthroscopist. When one is choosing which knot to tie, there are a variety of options, with each possessing its own inherent strengths and weaknesses. The West Point knot is a sliding-locking arthroscopic knot that is relatively easy to learn and has excellent knot security. This article details the appropriate manner in which to tie this knot.

Biceps Tenodesis and Intra-articular Decompression for Treatment of Superior Labral Tear from Anterior to Posterior and Associated Paralabral Cyst in Active Duty Military.

Background: To examine the outcomes of combined biceps tenodesis and indirect, intra-articular arthroscopic paralabral cyst decompression for the treatment of active duty military patients with superior labral from anterior to posterior tears and associated paralabral cysts. Methods: Retrospective chart review of all active duty patients at our institution from 2011 to 2014 with superior labral from anterior to posterior tears and associated paralabral cysts at the spinoglenoid notch treated with biceps tenodesis and indirect arthroscopic cyst decompression. Patient charts were examined for pre- and post-operative parameters including strength, range of motion, visual analog scale pain score, American Shoulder and Elbow Surgeon Score, and Single Assessment Numeric Evaluation Score. Results: Seven patients met study criteria. All patients presented with chronic shoulder pain and decreased external rotation strength, and three patients had clinically apparent muscular atrophy. Pre- and post-operative assessment showed external rotation strength increased from a median of 4 (range 4-4) to 5 (range 4-5; p-value = 0.014), Single Assessment Numeric Evaluation increased from a median of 50 (range 0-70) to 75 (range 30-95; p-value = 0.031), American Shoulder and Elbow Surgeon increased from a median of 46.0 (range 32.0-58.0) to 66.5 (range 58.0-98.0; p-value = 0.068), and visual analog scale pain score decreased from a median of 3 (range 1-8) to 0 (range 0-5; p-value = 0.017). Median follow-up was 66 wk (range 36-138 wk). The change was statistically significant (p <0.05) for external rotation strength, Single Assessment Numeric Evaluation, and VAS reduction. Post-operatively, all patients returned to full duty at a median of 20 wk (range 12-36 wk). Conclusion: The use of biceps tenodesis in conjunction with indirect, intra-articular arthroscopic paralabral cyst decompression is an effective technique in an active patient population with superior labral from anterior to posterior tear with associated paralabral cyst.

A History of Shoulder Instability in the Military: Where We Have Been and What We Have Learned.

Introduction: Shoulder instability is one of the most common pathologies seen by the orthopedic sports medicine surgeon. With a uniquely young, high-demand patient population in the U.S. Military, the incidence of shoulder instability is remarkably more common than the civilian population. As such, military orthopedic surgeons and sports medicine and shoulder specialists have developed a unique understanding and experience of shoulder instability. The historical advances of shoulder instability in the military have been instrumental in understanding the epidemiology, evaluation, pathology, treatment of first-time shoulder subluxations and dislocations, operative and non-operative treatment options, arthroscopic and open stabilization methods, management of the in-season athlete, treatment of combined and circumferential labral pathology, and associated pathology. Methods: The purpose of this article is to chronicle the experience of military orthopedic surgeons in treating shoulder instability. We discuss how this unique experience has led to a better understanding of the epidemiology and pathology of this condition and how we have adapted our clinical practice to improve patient outcomes. Results: The historical contribution of U.S. Military orthopedics to the understanding of shoulder instability has been monumental. This article reviews the evolution of shoulder instability treatment and the understanding as it has evolved in the U.S. Military. It further elaborates on our understanding of the epidemiology of shoulder instability in the U.S. Military, with attention given to our incidence of 1.69 per 1000 person-years, approximately 20 times higher incidence than the general population. We discuss known risk factors for dislocation that contribute to this incidence, which are specific to military service. We address pathologic changes seen following a first-time instability event, including an analysis of labral injury and the role of these pathologic changes in recurrent instability. We also review our results from arthroscopic evaluation of first-time dislocations and compare the pathologic changes with those following a first-time subluxation. Evaluation of treatment outcomes is discussed, comparing operative and non-operative results as well as open and arthroscopic stabilization in the U.S. Military population and contact/collision athletes. Finally, we address how these results drive our current treatment algorithm. Discussion and Conclusion: The physical demands of military service result in a high rate of shoulder instability relative to the general population. For years military orthopedic surgeons have sought to better understand this pathology and learn how to optimally manage it so as to reduce this heavy burden of disease. This article discusses our experience with treating shoulder instability, provides an overview of the lessons learned, and provides a historical perspective for the evolution of shoulder instability understanding in the U.S. Military.

Glenoid neck Hounsfield units on computed tomography can accurately identify patients with low bone mineral density.

BACKGROUND: Osteoporosis is a costly and morbid disease with the first presentation often with a fragility fracture. The purpose of this study was to assess whether Hounsfield unit (HU) measurements on shoulder computed tomography could identify patients at risk of osteoporosis and aid in its diagnosis. METHODS: We identified patients who had both a computed tomography scan of the glenoid and a dual-energy x-ray absorptiometry scan. Dual-energy x-ray absorptiometry results and HU measurements of the patients' glenoid were recorded. Differences in HU measurements between patients with normal and abnormal central bone mineral density (BMD) were assessed. Correlations were calculated, and receiver operating characteristics were examined. RESULTS: A total of 51 glenoids met the criteria. The mean glenoid HU measurement was 140.6 (95% confidence interval [CI], 120.1-161.1) in the osteoporotic group, 168.1 (95% CI, 152.7-183.5) in the osteopenic group, and 233.2 (95% CI, 210.1-256.4) in the normal BMD group (P < .001). There was a significant correlation between mean glenoid HU measurement and patients' t scores in the femoral neck (r = 0.581), total hip (r = 0.524), and lumbar spine (r = 0.345). The area under the receiver operating characteristic curve was 0.918. With 197 HUs used as the cutoff for diagnosis of abnormal BMD, the positive predictive value was 96.6%. With 257.1 HUs used as the cutoff, the negative predictive value was 100%. CONCLUSION: A patient with an HU measurement below 197 has a 97% chance of having low BMD, and a patient with a measurement over 257 likely has normal BMD. In patients with measurements between these values, a definitive diagnosis should be aggressively pursued. Opportunistic screening for a modifiable disease that has significant morbidity and mortality rates at no additional cost, radiation, or time is of great value.

Analysis of Orthopaedic Research Produced During the Wars in Iraq and Afghanistan.

BACKGROUND: Military orthopaedic surgeons have published a substantial amount of original research based on our care of combat-wounded service members and related studies during the wars in Iraq and Afghanistan. However, to our knowledge, the influence of this body of work has not been evaluated bibliometrically, and doing so is important to determine the modern impact of combat casualty research in the wider medical community. QUESTIONS/PURPOSES: We sought to identify the 20 most commonly cited works from military surgeons published during the Iraq and Afghanistan conflicts and analyze them to answer the following questions: (1) What were the subject areas of these 20 articles and what was the 2013 Impact Factor of each journal that published them? (2) How many citations did they receive and what were the characteristics of the journals that cited them? (3) Do the citation analysis results obtained from Google Scholar mirror the results obtained from Thompson-Reuters' Web of Science? METHODS: We searched the Web of Science Citation Index Expanded for relevant original research performed by US military orthopaedic surgeons related to Operation Iraqi Freedom and Operation Enduring Freedom between 2001 and 2014. Articles citing these studies were reviewed using both Web of Science and Google Scholar data. The 20 most cited articles meeting inclusion criteria were identified and analyzed by content domain, frequency of citation, and sources in which they were cited. RESULTS: Nine of these studies examined the epidemiology and outcome of combat injury. Six studies dealt with wound management, wound dehiscence, and formation of heterotopic ossification. Five studies examined infectious complications of combat trauma. The median number of citations garnered by these 20 articles was 41 (range, 28-264) in Web of Science. Other research citing these studies has appeared in 279 different journals, covering 26 different medical and surgical subspecialties, from authors in 31 different countries. Google Scholar contained 97% of the Web of Science citations, but also had 31 duplicate entries and 29 citations with defective links. CONCLUSIONS: Modern combat casualty research by military orthopaedic surgeons is widely cited by researchers in a diverse range of subspecialties and geographic locales. This suggests that the military continues to be a source of innovation that is broadly applicable to civilian medical and surgical practice and should encourage expansion of military-civilian collaboration to maximize the utility of the knowledge gained in the treatment of war trauma. LEVEL OF EVIDENCE: Level IV, therapeutic study.