John C. Dunn

Thirty-day morbidity and mortality after elective total shoulder arthroplasty: patient-based and surgical risk factors

BACKGROUND Total shoulder arthroplasty (TSA) is an effective treatment for painful glenohumeral arthritis, but its morbidity has not been thoroughly documented. METHODS The National Surgical Quality Improvement Program database was queried to identify all patients undergoing primary TSA between 2006 and 2011, with extraction of selected patient-based or surgical variables and 30-day clinical course. Postoperative complications were stratified as major systemic, minor systemic, major local, and minor local, and mortality was recorded. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were derived from bivariate and multivariable analysis to express the association between risk factors and clinical outcomes. RESULTS Among the 2004 patients identified, the average age was 69 years, and 57% were women. Obesity was present in 46%, and 48% had an American Society of Anesthesiologists classification of ≥3. The 30-day mortality and total complication rates were 0.25% and 3.64%, respectively. Comorbid cardiac disease (OR, 85.31; 95% CI, 8.15, 892.84) and increasing chronologic age (OR, 1.19; 95% CI, 1.06, 1.33) were independent predictors of mortality, whereas peripheral vascular disease was associated with statistically significant increase in any complication (OR, 6.25; 95% CI, 1.24, 31.40). Operative time >174 minutes was an independent predictor for development of a major local complication (OR, 4.05; 95% CI, 1.45, 11.30). Obesity was not associated with any specified complication after controlling for other variables. CONCLUSIONS Whereas TSA has low short-term rates of perioperative complications and mortality, careful perioperative medical optimization and efficient surgical technique should be emphasized to decrease morbidity and mortality.

Patient-based and surgical characteristics associated with the acute development of deep venous thrombosis and pulmonary embolism after spine surgery.

Study Design. Retrospective analysis of a prospectively collected data set. Objective. Identify the incidence of, and risk factors for, deep venous thrombosis (DVT) and pulmonary embolism (PE) after spine surgery. Summary of Background Data. Determination of ideal candidates for chemoprophylaxis after spine surgery is limited by the state of the literature, including incomplete understanding regarding the incidence of DVT and PE, as well as an inability to quantify specific risk factors among patients. Methods. The 2005 to 2011 data set of the National Surgical Quality Improvement Program was queried to identify all individuals having undergone spine surgery. Demographic data, medical comorbidities, surgical characteristics, and the presence of DVT, PE, and/or mortality were abstracted for all individuals meeting inclusion criteria. Unadjusted univariate analysis was performed to identify variables that were potentially associated with the development of DVT or PE after surgery. A multivariate logistic regression test, controlling for other factors present in the model, was subsequently performed. Predictor variables that maintained significance after multivariate testing were considered influential in the development of DVT and/or PE. Results. There were 27,730 patients who received spine procedures in this cohort. The average age was 56.4 (±15.1) years. Lumbar spine procedures made up 61% of interventions. Death occurred in 87 instances (0.3%). The venous thromboembolic rate was 1%, with 206 individuals (0.7%) sustaining DVT and 113 (0.4%) developing a PE. Body mass index 40 and greater, age 80 years and older, operative time exceeding 261 minutes, and American Society of Anesthesiologists classification 3 or higher were identified as significant independent predictors of DVT, whereas body mass index 40 and greater, operative time exceeding 261 minutes, and male sex were associated with the development of PE. Conclusion. Multiple independent risk factors for the development of DVT and/or PE after spine surgery were identified. Patients with these characteristics may require additional counseling, procedural modification, or prophylaxis against venous thromboembolic events. Level of Evidence: 2

The nature and extent of war injuries sustained by combat specialty personnel killed and wounded in Afghanistan and Iraq, 2003-2011.

BACKGROUND Previous studies regarding combat wounding have a limited translational capacity due to inclusion of soldiers from all military branches and occupational specialties as well as a lack of information regarding soldiers who died in theater. METHODS A search was performed of the Department of Defense Trauma Registry and Armed Forces Medical Examiner data set for the years 2003 to 2011 to identify all injured personnel with the military specialty 19D (cavalry scout). A manual search was conducted for each record identified, and age, rank, location and manner of injury, mechanism of injury, Injury Severity Score (ISS), and extent of wounding were abstracted. The incidence of injuries by body region and rates for specific types of wounds were determined. Statistically significant associations between rank, location of injury, manner of injury, body region involved, and injury mechanism were assessed using &khgr;2 analysis. Associations between ISS, rank, manner of injury, and survival were evaluated by t test with Satterthwaite correction. RESULTS A total of 701 casualties were identified with 3,189 distinct injuries. Mean (SD) age of injured personnel was 25.9 (6.0) years. Thirty-five percent of the cohort was composed of soldiers who died in theater. Explosions were the most common mechanism of injury (70%), while 18% of wounds occurred owing to gunshot. Extremity wounds and injuries to the head and neck represented 34% of casualty burden. Thoracic trauma occurred in 16%, and abdominal injuries occurred in 17%. Wounds with a frequency exceeding 5% included skin, extremity, facial, brain, and gastrointestinal injuries. Vascular injury occurred in 4%. Gunshot wounds were a greater cause of injury in Afghanistan (p = 0.001) and resulted in a higher percentage of thoracic injuries (p < 0.001). CONCLUSION The nature and extent of trauma sustained by combat-specific personnel seems to be different from that experienced by all soldiers deployed to a war zone. LEVEL OF EVIDENCE Epidemiologic/prognostic study, level III.

Pelvic, spinal and extremity wounds among combat-specific personnel serving in Iraq and Afghanistan (2003–2011): A new paradigm in military musculoskeletal medicine☆☆☆

INTRODUCTION Previous studies regarding musculoskeletal injuries sustained during war have been limited by a lack of specificity regarding wounds incurred by combat-specific personnel. This investigation endeavoured to develop a comprehensive catalogue of the extent of musculoskeletal trauma, as well as the frequency of distinct injuries, among soldiers possessing a single combat-specific specialty. METHODS The Department of Defense Trauma Registry (DoDTR) and the Armed Forces Medical Examiner System (AFMES) were queried for all individuals with the combat-specific designation of cavalry scout who sustained injuries during deployment between the years 2003 and 2011. This data was refined to include only those soldiers found to have injuries involving the spine, pelvis, or extremities. Soldier age, rank, injury location (Afghanistan or Iraq), injury scenario (combat vs. non-combat) and mechanism of wounding were recorded, as were injury-specific data. Statistical comparisons for categorical variables were made using the chi-square statistic. RESULTS Sixty-seven percent (n=472) of 701 cavalry scouts injured during deployment sustained one or more injuries to the musculoskeletal system. Mean age for the group was 25.9 (range 18-54) years and 3.3 musculoskeletal injuries were incurred on average per casualty. The majority of casualties occurred during combat and in the Iraq theatre. Sixty-nine percent (n=328) of musculoskeletal casualties were incurred following explosion, and 20% (n=94) occurred due to gunshot. No significant difference (p>0.05) was encountered for the risk of musculoskeletal injury by wound mechanism. Forty-six percent of all injuries involved the lower extremities, while 32% occurred in the upper extremities. Tibial fractures were the most common injury encountered (8%), while amputations comprised 11% of all wounds. Spinal cord injury occurred in 12% of all casualties and represented 4% of all musculoskeletal wounds. CONCLUSIONS This effort is among the first to combine complimentary data from the DoDTR and AFMES over a multi-year period in order to comprehensively catalogue musculoskeletal wounds sustained by combat-specific soldiers. This investigation highlights a 49% incidence of injuries involving the spine, pelvis, and/or extremities within a cohort of combat-specific soldiers. Elevated rates of amputations, spinal injuries, and pelvic trauma were also appreciated as compared to earlier reports.

Chronic Exertional Compartment Syndrome of the Leg in the Military

CECS is a common source of lower extremity disability among young athletic cohorts and military personnel. The five cardinal symptoms are pain, tightness, cramps, weakness, and diminished sensation. History and clinical examination remain the hallmarks for identifying CECS, although ICP measurements during exercise stress testing may be used to confirm diagnosis. Nonsurgical management is generally unsuccessful, although gait retraining may have benefits in selected individuals. When conservative measures have failed, operative management may be considered with fascial release of all affected compartments. Although clinical success has been documented in civilian cohorts, the results of surgical treatment in military service members have been far less reliable. Only approximately half of the military service members experience complete resolution of symptoms and at least 25% are unable to return to full duty.

Predictors of length of stay after elective total shoulder arthroplasty in the United States

BACKGROUND Total shoulder arthroplasty (TSA) is an increasingly used treatment of glenohumeral arthritis and proximal humerus fractures. However, patient-specific characteristics affecting length of hospital stay postoperatively have not been elucidated. METHODS All patients undergoing primary unilateral TSA between 2005 and 2011 were isolated from the National Surgical Quality Improvement Program database. Patient demographics, medical comorbidities, and selected surgical variables were extracted, and length of stay was established as the primary end point of interest. Risk factors were expressed as odds ratios (ORs) with 95% confidence intervals by bivariate and multivariable analysis. RESULTS A total of 2004 patients were identified; the average age was 68.8 years, and 57% were women. Mean length of stay after TSA was 2.2 days (standard deviation, 1.7), and 91% of cases received hospital discharge in <3 days. Multivariable logistic regression analysis identified renal insufficiency (OR, 11.35; P = .0002), increased age (OR, 2.13; P = .011), longer operative time (OR, 1.94; P = .0041), and American Society of Anesthesiologists class ≥3 (OR, 1.86; P = .0016) as the most significant risk factors for length of stay. Gender also influenced length of stay; women were more likely to stay ≥4 days (OR, 0.44; P < .0001). CONCLUSIONS Perioperative risk stratification and preoperative counseling are paramount for patients undergoing TSA, particularly for those individuals with cardiac and renal disease or of advancing age. These variables may effectively predict prolonged hospital stay after TSA.

Arthroscopic Shoulder Surgical Simulation Training Curriculum: Transfer Reliability and Maintenance of Skill Over Time.

BACKGROUND Surgical education is evolving as work hour constraints limit the exposure of residents to the operating room. Potential consequences may include erosion of resident education and decreased quality of patient care. Surgical simulation training has become a focus of study in an effort to counter these challenges. Previous studies have validated the use of arthroscopic surgical simulation programs both in vitro and in vivo. However, no study has examined if the gains made by residents after a simulation program are retained after a period away from training. METHODS In all, 17 orthopedic surgery residents were randomized into simulation or standard practice groups. All subjects were oriented to the arthroscopic simulator, a 14-point anatomic checklist, and Arthroscopic Surgery Skill Evaluation Tool (ASSET). The experimental group received 1 hour of simulation training whereas the control group had no additional training. All subjects performed a recorded, diagnostic arthroscopy intraoperatively. These videos were scored by 2 blinded, fellowship-trained orthopedic surgeons and outcome measures were compared within and between the groups. After 1 year in which neither group had exposure to surgical simulation training, all residents were retested intraoperatively and scored in the exact same fashion. Individual surgical case logs were reviewed and surgical case volume was documented. RESULTS There was no difference between the 2 groups after initial simulation testing and there was no correlation between case volume and initial scores. After training, the simulation group improved as compared with baseline in mean ASSET (p = 0.023) and mean time to completion (p = 0.01). After 1 year, there was no difference between the groups in any outcome measurements. CONCLUSION Although individual technical skills can be cultivated with surgical simulation training, these advancements can be lost without continued education. It is imperative that residency programs implement a simulation curriculum and continue to train throughout the academic year.

The Rising Incidence of Degenerative and Posttraumatic Osteoarthritis of the Knee in the United States Military.

BACKGROUND This investigation sought to quantify incidence rates (IRs) and risk factors for primary and secondary (ie, posttraumatic) osteoarthritis (OA) of the knee in an active military population. METHODS We performed a retrospective review of United States military active duty servicemembers with first-time diagnosis of primary (International Classification of Disease, 9th Edition code: 715.16) and secondary (International Classification of Disease, 9th Edition code: 715.26) OA of the knee between 2005 and 2014 using the Defense Medical Epidemiology Database. IRs and 95% CIs were expressed per 1000 person-years, with stratified subgroup analysis adjusted for sex, age, race, military rank, and branch of military service. Relative risk factors were evaluated using IR ratios and multiple regression analysis. RESULTS A total of 21,318 cases of OA of the knee were identified among an at-risk population of 13,820,906 person-years for an overall IR of 1.54 per 1000 person-years, including 19,504 cases of primary (IR: 1.41) and 1814 cases of secondary OA (IR: 0.13). The IRs of both primary and secondary OA increased significantly from 2005 to 2014. Increasing age (P < .0001); black race (P < .001); senior military rank (P < .0001); and Army, Marines, and Air Force services (P < .0001) were significantly associated with an increased risk for knee OA. CONCLUSION This study is the first large-scale report of knee OA in a young athletic population. An increasing incidence and several risk factors for knee OA were identified, indicating a need for better preventative strategies and forecasting the increased anticipated demands for knee arthroplasty among US military servicemembers.

Sternoclavicular Reconstruction in the Young Active Patient: Risk Factor Analysis and Clinical Outcomes at Short-Term Follow-up.

Objective: To determine the functional outcomes in young, active individuals after sternoclavicular (SC) joint reconstruction. Design: Level IV, case series. Setting: United States military hospitals, 2008–2012. Patients/Participants: Retrospective review of all consecutive patients from the Military Health System Management Analysis and Reporting Tool was performed. Patients who underwent other open-shoulder procedures (eg, acromioclavicular joint reconstruction), those of nonmilitary or retired status, and patients with under 12-month minimum follow-up without medical separation were excluded from further analysis. Intervention: Open reconstruction of SC joint dislocation. Main Outcome Measures: Primary outcomes of interest were clinical failure and medical separation due to persistent shoulder girdle dysfunction. Demographic data, surgical technique, outcomes, complications, and occupational military outcomes were recorded. Results: Fourteen patients, with an average age of 26 years, experienced 8 anterior (57.1%) and 6 posterior (42.9%) SC joint dislocations. Four patients (28.6%) presented with dysphagia or dyspnea, and 10 patients (71.4%) had a missed diagnosis with an average of 13 months until diagnosis. Twelve of 14 (85.7%) patients underwent figure-of-eight tendon reconstruction, and 10 (71.4%) were able to return to full active military duty at an average 26.8 ± 12.9 months follow-up. There were 6 complications in 5 patients (35.7%), whereas 2 (14.3%) reported persistent instability and 2 (14.3%) required reoperation. Conclusions: SC joint dislocations are rare injuries that are frequently missed on clinical presentation in this study. However, acute or delayed surgical reconstruction may afford predictable rates of return to function in young active military service members. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Effect of Operative Technique on Ulnar Nerve Strain following Surgery for Cubital Tunnel Syndrome

BackgroundThe aim of this study is to compare the amount of strain on the ulnar nerve based on elbow position after in situ release, subcutaneous transposition, submuscular transposition, and medial epicondylectomy.MethodsSix matched cadaver upper extremity pairs underwent ulnar nerve decompression, transposition in a sequential fashion, while five elbows underwent medial epicondylectomy. A differential variable reluctance transducer (DVRT) was placed in the ulnar nerve. An in situ release, a subcutaneous transposition, and a submuscular transposition were performed sequentially with the strain being measured after each procedure in neutral, full elbow flexion, and extension positions. The strain was then averaged and compared for each procedure. Five cadavers underwent medial epicondylectomy and were similarly tested.ResultsAfter the in situ release, there was no statistically significant change in strain in either flexion or extension. After a subcutaneous transposition, there was a statistically significant decrease in strain in full elbow flexion but not in extension. Similarly after a submuscular transposition, there was a statistically significant decrease in strain in full flexion but not in extension. There was not a statistically significant change in strain with medial epicondylectomy.ConclusionAn in situ release of the ulnar nerve at the elbow may relieve pressure on the nerve but does not address the problem of strain which may be the underlying pathology in many cases of ulnar neuropathy at the elbow (UNE). Transposition of the ulnar nerve anterior to the medial epicondyle addresses the problem of strain on the ulnar nerve. In addition, it does not create an increased strain on the ulnar nerve with elbow extension.