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ContextLower extremity bone stress injuries (BSIs) place a significant burden on the health and readiness of the US Armed Forces.ObjectiveTo determine if preinjury baseline performance on an expanded and automated 22-item version of the Landing Error Scoring System (LESS-22) was associated with the incidence of BSIs in a military training population.DesignProspective cohort study.SettingUS Military Academy at West Point, NY.Patients or Other ParticipantsA total of 2235 incoming cadets (510 females [22.8%]).Main Outcome Measure(s)Multivariable Poisson regression models were used to produce adjusted incidence rate ratios (IRRs) to quantify the association between preinjury LESS scores and BSI incidence rate during follow-up and were adjusted for pertinent risk factors. Risk factors were included as covariates in the final model if the 95% CI for the crude IRR did not contain 1.00.ResultsA total of 54 BSIs occurred during the study period, resulting in an overall incidence rate of 0.07 BSI per 1000 person-days (95% CI = 0.05, 0.09). The mean number of exposure days was 345.4 ± 61.12 (range = 3–368 days). The final model was adjusted for sex and body mass index and yielded an adjusted IRR for a LESS-22 score of 1.06 (95% CI = 1.002, 1.13; P = .04), indicating that each additional LESS error documented at baseline was associated with a 6.0% increase in the incidence rate of BSI during the follow-up period. In addition, 6 individual LESS-22 items, including 2 newly added items, were significantly associated with the BSI incidence.ConclusionsWe provided evidence that performance on the expanded and automated version of the LESS was associated with the BSI incidence in a military training population. The automated LESS-22 may be a scalable solution for screening military training populations for BSI risk.

Background In-season return to play after anterior glenohumeral instability is associated with high rates of recurrent instability and the need for surgical stabilization. We are not aware of previous studies that have investigated in-season return to play after posterior glenohumeral instability; furthermore, as posterior shoulder instability in collision athletes occurs frequently, understanding the expected outcome of in-season athletes may improve the ability of physicians to provide athletes with a better understanding of the expected outcome of their injury and their ability to return to sport. Questions/purposes (1) What proportion of athletes returned to play during the season after posterior instability in collegiate football players? (2) How much time did athletes lose to injury, what proportion of athletes opted to undergo surgery, and what proportion of athletes experienced recurrent instability after a posterior instability episode during a collegiate football season? Methods A multicenter, prospective, observational study of National Collegiate Athletic Association (NCAA) Division 1 Football Bowl Subdivision athletes was performed at three US Military Service Academies. Ten athletes who sustained a posterior instability event during the regular football season and who pursued a course of nonoperative treatment were identified and prospectively observed through the subsequent season. All athletes in the observed cohort attempted an initial course of nonoperative treatment during the season. All athletes sustained subluxation events initially identified through history and physical examination at the time of injury. None of the athletes sustained a dislocation event requiring a manual reduction. Intraarticular pathology consisting of posterior labral pathology was further subsequently identified in all subjects via MRI arthrogram. Return to play was the primary outcome of interest. Time lost to injury, surgical intervention, and subsequent instability were secondary outcomes. Results Of the 10 athletes who opted for a trial of initial nonoperative management, seven athletes were able to return to play during the same season. Although these seven athletes returned within 1 week of their injury (median of 1 day), 5 of 7 athletes sustained recurrent subluxation events with a median (range) of four subluxation events per athlete (0 to 8) during the remainder of the season. Seven athletes were treated surgically after the completion of their season, four of whom returned to football. Conclusion This study suggests that although collegiate football players are able to return to in-season sport after a posterior glenohumeral instability event, they will likely sustain multiple recurrent instability events and undergo surgery after the season is completed. The results of this study can help guide in-season management of posterior shoulder instability by allowing more appropriate postinjury counseling and decision making through the identification of those athletes who may require additional attention from medical staff during the season and possible modifications to training regimens to minimize long-term disability. Further prospective studies involving a larger cohort over several seasons should be performed through collaborative studies across the NCAA that better assess function and injury risk factors before beginning collegiate athletics. This would better characterize the natural history and associated functional limitations that athletes may encounter during their collegiate careers. Level of evidence Level IV, prognostic study.

The purpose of this project is to design a device that provides skeletal traction to a patient with a fractured femur in an aeromedical evacuation environment. Skeletal traction is typically provided by using weights and cable to provide tension onto a fractured limb. However, in an aeromedical evacuation environment, the forces vary and the environment is not stable, so the traditional method to provide skeletal traction is not suitable. Therefore, we designed and tested a device that could provide skeletal traction to a femoral fracture in an aeromedical evacuation environment.

Background: Patient-reported outcomes (PROs) measure progression and quality of care. While legacy PROs such as the International Knee Documentation Committee (IKDC) survey are well-validated, a lengthy PRO creates a time burden on patients, decreasing adherence. In recent years, PROs such as the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function and Pain Interference surveys were developed as computer adaptive tests, reducing time to completion. Previous studies have examined correlation between legacy PROs and PROMIS; however, no studies have developed effective prediction models utilizing PROMIS to create an IKDC index. While the IKDC is the standard knee PRO, computer adaptive PROs offer numerous practical advantages. Purpose: To develop a nonlinear predictive model utilizing PROMIS Physical Function and Pain Interference to estimate IKDC survey scores and examine algorithm sensitivity and validity. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The MOTION (Military Orthopaedics Tracking Injuries and Outcomes Network) database is a prospectively collected repository of PROs and intraoperative variables. Patients undergoing knee surgery completed the IKDC and PROMIS surveys at varying time points. Nonlinear multivariable predictive models using Gaussian and beta distributions were created to establish an IKDC index score, which was then validated using leave-one-out techniques and minimal clinically important difference analysis. Results: A total of 1011 patients completed the IKDC and PROMIS Physical Function and Pain Interference, providing 1618 complete observations. The algorithms for the Gaussian and beta distribution were validated to predict the IKDC (Pearson = 0.84-0.86; R2 = 0.71-0.74; root mean square error = 9.3-10.0). Conclusion: The publicly available predictive models can approximate the IKDC score. The results can be used to compare PROMIS Physical Function and Pain Interference against historical IKDC scores by creating an IKDC index score. Serial use of the IKDC index allows for a lower minimal clinically important difference than the conventional IKDC. PROMIS can be substituted to reduce patient burden, increase completion rates, and produce orthopaedic-specific survey analogs.

Objectives: To prospectively determine the amount of bone loss associated with posterior instability and to determine predisposing factors based on pre-instability imaging. Methods: A total of 714 athletes were evaluated prospectively for 4+ years. At baseline, every patient received a subjective history of shoulder instability as well as bilateral noncontrast shoulder magnetic resonance imaging (MRI) regardless of any reported history of shoulder instability. The cohort was prospectively followed during the study period, and those who were diagnosed with posterior glenohumeral instability were identified. Postinjury MRIs with contrast were obtained and compared with the screening MRI. Glenoid version, perfect-circle-based bone loss was measured for each patient’s pre- and post-injury MRI using previously described methods. Results: Of the 714 athletes (1428 shoulders) who were prospectively followed during the 4-year period, 5 athletes (7 shoulders) sustained a first-time posterior instability event (1 dislocation, 5 subluxations), and one athlete (1 shoulder) sustained a recurrent posterior instability event. At baseline, 6 out of 8 shoulders were noted to have some level of dysplasia and/or bone loss. Glenoid bone loss increased significantly after instability event in terms of percentage linear bone loss (6.96 ± 4.66 versus 13.54% ± 4.66, p=0.014) and total area of bone loss (3.51 ± 2.78 versus 8.10 ± 3.25, p= 0.009). Baseline glenoid retroversion >10° was associated with a significant greater percentage of bone loss (2.58 ± 1.94 versus 5.79 ± 1.28, p=0.028). Conclusions: Patients with posterior instability tend to have baseline dysplasia and/or glenoid bone loss. Glenoid bone loss of 8.1% was observed after index posterior instability event, with baseline glenoid retroversion >10° being associated with more bone loss.

Objectives: There are no studies that directly compare beach chair (BC) versus lateral decubitus (LD) position for anterior instability. In the only systematic review evaluating BC vs LD, bone loss is not accounted for in the recurrence rate. The purpose of this is to identify predictors of shoulder instability recurrence and revision after anterior shoulder stabilization surgery in a young, high demand population and evaluate surgical position and glenoid bone loss as independent predictors of the outcomes of interest, recurrence and revision. Methods: A consecutive series of 641 arthroscopic Bankart stabilizations were performed by sports-medicine certified and fellowship trained orthopaedic surgeons from 2009-2016 in either the BC or LD position. Patients were included if they underwent an isolated primary arthroscopic anterior capsulolabral repair. Patients were excluded if concomitant labral repair and/or Remplissage procedures were performed at the time of surgery. Shoulders were additionally excluded if magnetic resonance imaging (MRI) was not available at the time of preoperative evaluation or the patient was lost to follow-up. All shoulders were evaluated for glenohumeral bone loss using the perfect circle technique on the sagittal en-face MRI as well as for bipolar lesions according to the on/off-track method of Diagacomo et al. Glenoid bone loss was grouped into three categories: 13.5%. The primary outcomes of interest were recurrent instability and revision stabilization. Recurrent instability was defined as the presence of a recurrent subluxation and or dislocation event and/or the presence of a positive apprehension. Multivariable logistic regression models were used to assess the relationships of outcomes with age, position, glenoid bone loss group, and, track. Results: 641 shoulders with a mean age of 22.3 years (SD 4.46) underwent isolated arthroscopic Bankart repair and were followed for a mean 6 years. The overall recurrent instability and revision rates were 15.7% (101/641) and 11.5% (74/641). Recurrent instability was observed in 15.6% (24/154) and 15.9% (77/487) of LD and BC shoulders, respectively. After adjusting for confounders, multivariable logistic regression found no association between surgical position and recurrent instability (p=0.85). Age was an independent predictor for recurrence. The odds of recurrence were 1.58 times higher per 4.5 years (1 standard deviation) decrease in age (PConclusions: Among fellowship-trained orthopaedic surgeons the overall failure of primary arthroscopic anterior shoulder stabilization was 15.7% in a high-demand population and equivalent outcomes may be anticipated with arthroscopic Bankart repair performed in the BC or LD position. In multivariable analysis, younger age, but not surgical position, was an independent risk factor for recurrence.

Background: The preferred patient-reported outcome measure for the assessment of shoulder conditions continues to evolve. Previous studies correlating the Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive tests (CATs) to the American Shoulder and Elbow Surgeons (ASES) score have focused on a singular domain (pain or physical function) but have not evaluated the combined domains of pain and physical function that compose the ASES score. Additionally, previous studies have not provided a multivariable prediction tool to convert PROMIS scores to more familiar legacy scores. Purpose: To establish a valid predictive model of ASES scores using a nonlinear combination of PROMIS domains for physical function and pain. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: The Military Orthopaedics Tracking Injuries and Outcomes Network (MOTION) database is a prospectively collected repository of patient-reported outcomes and intraoperative variables. Patients in MOTION research who underwent shoulder surgery and completed the ASES, PROMIS Physical Function, and PROMIS Pain Interference at varying time points were included in the present analysis. Nonlinear multivariable predictive models were created to establish an ASES index score and then validated using “leave 1 out” techniques and minimal clinically important difference /substantial clinical benefit (MCID/SCB) analysis. Results: A total of 909 patients completed the ASES, PROMIS Physical Function, and PROMIS Pain Interference at presurgery, 6 weeks, 6 months, and 1 year after surgery, providing 1502 complete observations. The PROMIS CAT predictive model was strongly validated to predict the ASES (Pearson coefficient = 0.76-0.78; R2 = 0.57-0.62; root mean square error = 13.3-14.1). The MCID/SCB for the ASES was 21.7, and the best ASES index MCID/SCB was 19.4, suggesting that the derived ASES index is effective and can reliably re-create ASES scores. Conclusion: The PROMIS CAT predictive models are able to approximate the ASES score within 13 to 14 points, which is 7 points more accurate than the ASES MCID/SCB derived from the sample. Our ASES index algorithm, which is freely available online ( https://osf.io/ctmnd/ ), has a lower MCID/SCB than the ASES itself. This algorithm can be used to decrease patient survey burden by 11 questions and provide a reliable ASES analog to clinicians.

Introduction Musculoskeletal injuries are an endemic amongst U.S. Military Service Members and significantly strain the Department of Defense’s Military Health System. The Military Health System aims to provide Service Members, military retirees, and their families the right care at the right time. The Military Orthopedics Tracking Injuries and Outcomes Network (MOTION) captures the data that can optimize musculoskeletal care within the Military Health System. This report provides MOTION structural framework and highlights how it can be used to optimize musculoskeletal care. Materials and Methods MOTION established an internet-based data capture system, the MOTION Musculoskeletal Data Portal. All adult Military Health System patients who undergo orthopedic surgery are eligible for entry into the database. All data are collected as routine standard of care, with patients and orthopedic surgeons inputting validated global and condition-specific patient reported outcomes and operative case data, respectively. Patients have the option to consent to allow their standard of care data to be utilized within an institutional review board approved observational research study. MOTION data can be merged with other existing data systems (e.g., electronic medical record) to develop a comprehensive dataset of relevant information. In pursuit of enhancing musculoskeletal injury patient outcomes MOTION aims to: (1) identify factors which predict favorable outcomes; (2) develop models which inform the surgeon and military commanders if patients are behind, on, or ahead of schedule for their targeted return-to-duty/activity; and (3) develop predictive models to better inform patients and surgeons of the likelihood of a positive outcome for various treatment options to enhance patient counseling and expectation management. Results This is a protocol article describing the intent and methodology for MOTION; thus, to date, there are no results to report. Conclusions MOTION was established to capture the data that are necessary to improve military medical readiness and optimize medical resource utilization through the systematic evaluation of short- and long-term musculoskeletal injury patient outcomes. The systematic enhancement of musculoskeletal injury care through data analyses aligns with the National Defense Authorization Act (2017) and Defense Health Agency’s Quadruple Aim, which emphasizes optimizing healthcare delivery and Service Member medical readiness. This transformative approach to musculoskeletal care can be applied across disciplines within the Military Health System.

Objectives: Shoulder instability is a common cause of shoulder pain and dysfunction, particularly in young and active individuals. While anterior instability remains the most common type, recent literature shows that posterior instability occurs more frequently than previously thought. As opposed to its anterior counterpart, posterior instability most often presents with pain, particularly in active individuals involved in dynamic posterior loading of the shoulder resulting in repetitive microtrauma of the posterior capsulolabral structures. While arthroscopic stabilization for posterior glenohumeral instability has shown excellent success preventing recurrent instability and allowing return to sport, eventual progression to glenohumeral arthritis remains a concern in these patients. However, the rate of and risk factors for arthritis post-surgery in young and high demand populations have not been described in the literature and may be important in guiding decision making when treating the young patient with posterior shoulder instability. The purpose of this study was to evaluate the rate of progression to glenohumeral arthritis and identify potential risk factors after arthroscopic posterior stabilization in a young and high demand population. Methods: This study included 110 active duty servicemembers identified in the Military Heath System (MHS) with ICD-9/ICD-10 posterior shoulder instability who underwent primary arthroscopic surgical stabilization and had postoperative imaging or medical records available over a twelve-year period between January 2004 and September 2016. All procedures were performed at a single institution. Patients were excluded if the they had previously undergone a stabilization procedure on the shoulder of interest, if no pre-operative imaging was available, if they did not have a minimum follow-up of four years, or if operative information regarding the number of anchors used was unavailable. Presence of arthritis (yes/no) was defined over follow-up using radiographic parameters as described by Samielson and Prieto identifying patients with at least ‘mild arthritis’. Kaplan-Meier survival curves were estimated for development of arthritis and compared by patient characteristics using log-rank tests. Cox proportional hazard models were used to calculate Hazard Ratios (HR) with 95% confidence intervals (95% CI) associated with patient characteristics as predictors of the development of glenohumeral arthritis. Results: Among the 110 patients with posterior shoulder instability requiring surgical fixation, 12% (13/110) developed glenohumeral arthritis. The mean age of all patients was 23.9 years (SD 6.71). The median time to diagnosis of arthritis was 7 years and the median follow-up time was 8 years (IQR 5;11). Kaplan-Meier curves showed differences in time to arthritis among patient groups stratified by age and index surgery anchor number (log rank p for each Conclusions: No previous study has reported the incidence and risk factors for glenohumeral arthritis after arthroscopic surgical stabilization for posterior shoulder instability. In the current study, generally young and high demand patient population, the rate of progression to glenohumeral arthritis after posterior stabilization surgery was 12%. Within this cohort, older age and higher number of anchors used were associated with progression to arthritis. The incidence of arthritis over follow up post surgery was lower than incidences previously described in older populations, a finding which may advocate for early surgical intervention for a young patient presenting with posterior shoulder instability.

BACKGROUND: Meniscal allograft transplantation (MAT) is considered a viable surgical treatment option in the symptomatic, postmeniscectomy knee and as a concomitant procedure with ACL revision and articular cartilage repair. Although promising outcomes have recently been reported in active and athletic populations, MAT has not been well-studied in the high-demand military population. QUESTIONS/PURPOSES: (1) What proportion of active-duty military patients who underwent MAT returned to full, unrestricted duty? (2) What demographic and surgical variables, if any, correlated with return to full, unrestricted duty? METHODS: Between 2005 and 2015, three fellowship-trained sports surgeons (TMD, SJS, BDO) performed 110 MAT procedures in active-duty military patients, of which 95% (104 patients) were available for follow-up at a minimum 2 years (mean 2.8 ± SD 1.1 year). During the study period, indications for MAT generally included unicompartmental pain and swelling in a postmeniscectomized knee and as a concomitant procedure when a meniscal-deficient compartment was associated with either an ACL revision reconstruction or cartilage repair. Demographic and surgical variables were collected and analyzed. The primary endpoints were the decision for permanent profile activity restrictions and military duty termination by a medical board. The term “medical board” implies termination of military service because of medical reasons. We elected to set statistical significance at p < 0.001 to reduce the potential for spurious statistical findings in the setting of a relatively small sample size. RESULTS: Forty-six percent (48 of 104) of eligible patients had permanent profile activity restrictions and 50% (52 of 104) eventually had their military duty terminated by a military board. Only 20% (21 of 104) had neither permanent profile activity restrictions nor medical-board termination and were subsequently able to return to full duty, and only 13% (13 of 104) continued unrestricted military service beyond 2 years after surgery. Age, gender, tobacco use, and BMI did not correlate with return to full duty. Combat arms soldiers were less likely to have permanent profile activity restrictions (odds ratio 4.76 [95% confidence interval 1.93 to 11.8]; p = 0.001) and were more likely to return to full duty than soldiers in support roles (OR 0.24 [95% CI 0.09 to 0.65]; p = 0.005), although these findings did not reach statistical significance. Officers were more likely to return to full duty than enlisted soldiers at more than 2 years after surgery (OR 17.44 [95% CI 4.56 to 66.65]; p < 0.001). No surgical variables correlated with return-to-duty endpoints. CONCLUSIONS: Surgeons should be aware of the low likelihood of return to military duty at more than 2 years after MAT and counsel patients accordingly. Based on this study, MAT does not appear to be compatible with continued unrestricted military duty for most patients. LEVEL OF EVIDENCE: IV, therapeutic study.

The biomechanical strength of a bone–patellar tendon–bone graft in the tibia may vary depending on whether the interference screw abuts the cancellous vs the cortical surface of the bone plug. In a porcine model, 10×20-mm bone–patellar tendon–bone grafts were prepared and fixed in a 10-mm diameter tibial tunnel using a 9×25-mm titanium interference screw. The screw was positioned on the cancellous surface of the graft in group A (n=13) vs the cortical side of the graft in group B (n=14). Specimens underwent precycling, cyclic loading, and load-to-failure testing. The mean ultimate failure load was 493±245 N for group A vs 304±145 N for group B ( P =.008). Sixty-nine percent of specimens in group A survived 1000 cycles of load testing compared with 21% of specimens in group B. Forty-three percent of specimens in group B sustained intratendinous failure adjacent to the bone plug compared with 15% of specimens in group A. Orientation of the tibial interference screw along the cancellous vs the cortical side of the graft results in superior cyclic loading and ultimate failure load characteristics. Additionally, screw placement along the cortical side may weaken the tendon interface and lead to tendon failure under load. This study indicates that placement of the tibial interference screw along the cancellous side of the graft is biomechanically favorable. However, the clinical ramifications of these findings are not clear. [ Orthopedics . 2018; 41(6):337–342.]

Bone stress injuries occur when forces applied to a bone for an extended period exceed the ability of the bone to adequately remodel. These injuries, which range from stress reactions to nondisplaced and even displaced fractures, most often affect people who experience high levels of repetitive stress and loading in the lower extremity or changes in physical activity level. For example, stress fractures are common in endurance athletes, in athletes engaged in preseason and early-season conditioning, and in military recruits. In the military, these injuries are most often encountered during basic training, when new recruits undergo the rigors of intense physical activity to which they may not be accustomed. Female athletes and athletes with poor nutritional status are at elevated risk for injury. Bone stress injuries are difficult to diagnose with radiographs alone. Making the correct diagnosis may require a combination of physical examination, advanced imaging, and an index of suspicion. Differences in injury location account for variations in risk for nonunion, displacement, and other complications. For low-risk injuries, treatment typically consists of reduced weight-bearing for several weeks with gradual return to activity. Higher-risk injuries need to be closely monitored for progression and may require operative intervention. Even after surgery, some types of stress fractures may take several months to achieve radiographic union. In addition, underlying nutritional or metabolic deficiencies may need to be treated to prevent future injuries. In this article, we review the diagnosis, management, and prevention of bone stress injuries with a focus on more serious manifestations, such as stress fracture.

Background Little is known about the injury rates in Major League Baseball (MLB) players, as a formal injury surveillance system does not exist. The goal of this study was to characterize the epidemiology of MLB injuries over a 7-year period. Hypothesis Injuries in MLB would be common. Study Design Descriptive epidemiologic study. Methods The authors analyzed the MLB disabled list data from 2002 through 2008. Injuries were analyzed for differences between seasons, as well as during seasons on a monthly basis. The injuries were categorized by major anatomic zones and then further stratified based on injury type. Position-specific subanalyses for pitcher and position players were performed. Results From the 2002 season through the 2008 season, an average of 438.9 players per year were placed on the disabled list, for a rate of 3.61 per 1000 athlete-exposures. There was a significant 37% increase in injuries between 2005 and 2008. The highest injury rate during the season was during the month of April (5.73/1000 exposures) and the lowest in September (0.54/1000 exposures). No differences were noted in the injury rates between the National League and the American League (incidence rate ratio [IRR] = 1.06; 95% confidence interval [CI] = 0.98, 1.15). Pitchers experienced 34% higher incidence rates for injury compared with fielders during the study period (IRR = 1.34; 95% CI = 1.25, 1.44). Among all player injuries, upper extremity injuries accounted for 51.4% while lower extremity injuries accounted for 30.6%. Injuries to the spine and core musculature accounted for 11.7% while other injuries and illnesses were 6.3% of the total disabled list entries. There was a significant association between position played and anatomic region injured ( P < .001), with pitchers experiencing a significantly greater proportion of injuries to the upper extremity (67.0%; 95% CI = 63.1%, 70.9%) compared with fielders (32.1%; 95% CI = 29.1%, 35.1%). Conversely, fielders experienced a significantly greater proportion of injuries to the lower extremity (47.5%; 95% CI = 43.8%, 51.1%) compared with pitchers (16.9%; 95% CI = 14.9%, 18.8%). The mean number of days on the disabled list was 56.6. Overall, a greater proportion of disability days were experienced by pitchers (62.4%; 95% CI = 62.0%, 62.8%; P < .001) compared with fielders (37.6%; 95% CI = 37.3%, 37.9%). Conclusion Injuries in MLB resulting in disabled list designation are common. Upper extremity injuries were predominant in pitchers, while lower extremity injuries are more common in position players. These data may be used in the development of a formal MLB injury database, as well as in the development and implementation of specific preseason training and in-season conditioning for injury prevention.

PurposeThe purpose of this paper is to investigate the use of medical‐grade polymethylmethacrylate (PMMA) in fused deposition modeling (FDM) to fabricate porous customized freeform structures for several applications including craniofacial reconstruction and orthopaedic spacers. It also aims to examine the effects of different fabrication conditions on porosity and mechanical properties of PMMA samples.Design/methodology/approachThe building parameters and procedures to properly and consistently extrude PMMA filament in FDM for building 3D structures were determined. Two experiments were performed that examined the effects of different fabrication conditions, including tip wipe frequency, layer orientation, and air gap (AG) (or distance between filament edges) on the mechanical properties and porosity of the fabricated structures. The samples were characterized through optical micrographs, and measurements of weight and dimensions of the samples were used to calculate porosity. The yield strength, strain, and modulus of elasticity of the samples were determined through compressive testing.FindingsResults show that both the tip wipe frequency (one wipe every layer or one wipe every ten layers) and layer orientation (transverse or axial with respect to the applied compressive load) used to fabricate the scaffolds have effects on the mechanical properties and resulting porosity. The samples fabricate in the transverse orientation with the high tip wipe frequency have a larger compressive strength and modulus than the lower tip wipe frequency samples (compressive strength: 16±0.97 vs 13±0.71 MPa, modulus: 370±14 vs 313±29 MPa, for the high vs low tip wipe frequency, respectively). Also, the samples fabricated in the transverse orientation have a larger compressive strength and modulus than the ones fabricated in the axial orientation (compressive strength: 16±0.97 vs 13±0.83 MPa, modulus: 370±14 vs 281±22 MPa; for samples fabricated with one tip wipe per layer in the transverse and axial orientations, respectively). In general, the stiffness and yield strength decreased when the porosity increased (compressive strength: 12±0.71 to 7±0.95 MPa, Modulus: 248±10 to 165±16 MPa, for samples with a porosity ranging from 55 to 70 percent). As a demonstration, FDM is successfully used to fabricate patient‐specific, 3D PMMA implants with varying densities, including cranial defect repair and femur models.Originality/valueThis paper demonstrates that customized, 3D, biocompatible PMMA structures with varying porosities can be designed and directly fabricated using FDM. By enabling the use of PMMA in FDM, medical implants such as custom craniofacial implants can be directly fabricated from medical imaging data improving the current state of PMMA use in medicine.

BackgroundOver 30 years ago, Feagin and Curl reported on the diagnosis and treatment of “isolated” injuries of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the long-term results of the patients initially diagnosed with tears of the ACL, with special emphasis on those treated with primary repair.HypothesisLong-term results are unsatisfactory for open evaluation and treatment of ACL injuries with or without primary repair.Study DesignCase series; Level of evidence, 4.MethodsFollow-up was available on 34 of the original 57 patients (60%) who had ACL tears on evaluation by arthrotomy. The average age at the index procedure was 20 years, and average follow-up was 32 (range, 29-36) years. Twenty-five of the 26 complete ACL tears were treated with primary repair. None of the 8 partial tears was repaired. Evaluations included the subjective and symptom ratings of the International Knee Documentation Committee (IKDC) evaluation form, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner activity scale, and SANE rating.ResultsFor the IKDC subjective score, 18 of 34 patients rated their knees as normal or nearly normal. The Lysholm scores averaged 70.1 (range, 20-100). The average SANE rating at 5 years was 74.8 (range, 49-110), and the current SANE rating averaged 68.9 (range, 10-100). The overall KOOS rating averaged 68.6 (range, 26.4-100). The Tegner activity score was 3.7. There was little difference between patients with unrepaired partial tears and those who had primary repairs.ConclusionAt more than 30-year follow-up, patients have decreased activity levels and an equal mix of acceptable and unacceptable outcomes. We were unable to identify any predictive factors that correlated with the results; however, subsequent meniscal surgery did correlate with poor results. The results at greater than 30 years reinforce the 5-year results that showed unsatisfactory results after the open evaluation and treatment of ACL injuries with or without repair.

Background: Initial treatment of Eichenholtz stage I Charcot arthropathy of the foot generally is total contact casting and nonweightbearing. This method, however, often is time-consuming and has a poor result. This study was done to determine the success rate of total contact casting in a small group of patients and to establish a benchmark time period for treatment. Methods: Ten subjects with acute Eichenholtz stage I (stage of development) Charcot foot arthropathy were prospectively treated with weightbearing total contact cast therapy, undergoing biweekly cast changes. One subject did not complete the study. Subjects were monitored with biweekly clinical examination, limb volume measurement, and radiographs. The average age was 58.2 (range 39 to 72) years and weight was 216.9 (range 160 to 275) pounds. Results: All subjects were able to use commercially available depth-inlay shoes and custom accommodative foot orthoses at an average of 9.2 (range 8 to 16) weeks. One subject developed a superficial ulcer that resolved with footwear modification. Conclusion: This preliminary study supports the use of total contact cast therapy and weightbearing in the treatment of acute Charcot foot arthropathy. When the total contact cast was changed every 14 days, all subjects were able to use commercially available depth-inlay shoes and custom orthoses.

Aortic surgery is associated with a high incidence of perioperative complications, affecting virtually every organ system. The development of these complications is influenced by several factors, including whether surgery was emergent or elective, the location and duration of aortic cross-clamping, and the presence of coexisting disease states. The occurrence of end-organ damage reflects two main processes which are set in motion by aortic cross-clamping. The haemodynamic response refers to the changes produced in preload, afterload, and myocardial contractility. The humoral response refers to the formation and release of a series of mediators that both reflect and cause an ischaemia–reperfusion injury process. A clear understanding of the pathophysiological mechanisms involved in these processes will aid the clinician in adopting a rational approach to the care of patients undergoing aortic surgery.

Management of displaced midshaft clavicle fractures in the military, a largely shoulder-bearing population, is controversial. We aimed to report the military-relevant functional outcomes after plate fixation. We performed a nested cross-sectional analysis of active duty service members enrolled in an ongoing multicenter, randomized trial on clavicle plating. For this analysis, we included subjects with 26 months follow-up. Outcome measures included radiographic appearance, physical examination, a military-specific questionnaire, and validated shoulder surveys. Mean follow-up for 28 clavicle fractures was 13 months. Union rate by 12 weeks was 93% (26/28). There was one case of soft tissue irritation requiring hardware removal. At latest follow-up, 75% of patients were satisfied; 68% had mild/no pain; 79% had full range of motion; 75% could perform push-ups; and 21% have deployed. For the majority of active duty personnel, rapid healing, return to military-specific tasks, and satisfaction with outcome are possible after plate fixation of clavicle fractures. However, approximately 25% report some functional limitations at 1 year.

We conducted a study to characterize compression forces and pullout strengths of 4 commercially available bioabsorbable nails and screws in a synthetic bone model. A piezoelectric sensor was used to measure peak compression forces, and a material testing machine was used to measure maximum pullout strengths. The strongest compression force was found for SmartScrew (12.7 N), then SmartNail (12.3 N), LactoNail (8.5 N), and ReUnite Screw (5.1 N). Mean compression force was significantly (P.05) different between LactoNail and SmartScrew, ReUnite Screw and SmartNail, and ReUnite Screw and SmartScrew. The most pullout strength was found for SmartScrew (530 N), then ReUnite Screw (414 N), SmartNail (336 N), and LactoNail (189 N). These values were all statistically significantly (P.05) different from each other. In this model, SmartScrew had the overall strongest compression force and most pullout strength.

A prospective, longitudinal analysis of injuries sustained by a large combat-deployed maneuver unit has not been previously performed.A detailed description of the combat casualty care statistics, distribution of wounds, and mechanisms of injury incurred by a U.S. Army Brigade Combat Team during "The Surge" phase of Operation Iraqi Freedom was performed using a centralized casualty database and an electronic medical record system.Among the 4,122 soldiers deployed, there were 500 combat wounds in 390 combat casualties. The combat casualty rate for the Brigade Combat Team was 75.7 per 1,000 soldier combat-years. The % killed in action (KIA) was 22.1%, and the %died of wounds was 3.2%. The distribution of these wounds was as follows: head/neck 36.2%, thorax 7.5%, abdomen 6.9%, and extremities 49.4%. The percentage of combat wounds showed a significant increase in the head/neck region (p0.0001) and a decrease in the extremities (p0.03) compared with data from World War II, Korea, and Vietnam. The percentage of thoracic wounds (p0.03) was significantly less than historical data from World War II and Vietnam. The %KIA was significantly greater in those soldiers injured by an explosion (26.3%) compared with those soldiers injured by a gunshot wound (4.6%; p = 0.003). Improvised explosive devices accounted for 77.7% of all combat wounds.There was a significantly higher proportion of head/neck wounds compared with previous U.S. conflicts. The 22.1% KIA was comparable with previous U.S. conflicts despite improvements in individual/vehicular body armor and is largely attributable to the lethality of improvised explosive devices. The lethality of a gunshot wound in Operation Iraqi Freedom has decreased to 4.6% with the use of individual body armor.

High-energy injuries may result in a femur fracture with resultant bending of a previously placed intramedullary femoral nail. A bend of the nail in the sagittal plane presents unique challenges for nail extraction and subsequent exchange nailing. The described surgical technique illustrates a simple method to straighten the sagittal plane bend in situ and performs exchange nailing although maintaining symmetric femoral length and rotation.

Background Previous studies have shown that women involved in similar activities as men are at increased risk for anterior cruciate ligament injuries. Hypothesis The incidence rate of complete anterior cruciate ligament tears for men and women in our athletic, college-aged population is similar. Study Design Descriptive epidemiology study. Methods Students graduating in class years 1994 to 2003 at our institution who sustained complete anterior cruciate ligament tears were assessed for mechanism of injury and type of sport played at time of injury. We calculated the incidence proportion, an estimation of risk, by gender and class year, and the incidence proportion ratio comparing men and women by class year. We also calculated incidence rates by gender and type of sport played and incidence rate ratios comparing men and women. Results There were 353 anterior cruciate ligament injuries in the 10 classes studied. We found an overall, 4-year incidence proportion of 3.24 per 100 (95% confidence interval, 2.89-3.63) for men and 3.51 (95% confidence interval, 2.65-4.65) for women (incidence proportion ratio, 1.09 [95% confidence interval, 0.80-1.47]). The overall anterior cruciate ligament injury rate, excluding male-only sports, was significantly greater in women (incidence rate ratio, 1.51 [95% confidence interval, 1.03-2.21]). We found significantly greater injury rates among women in a gymnastics course (incidence rate ratio, 5.67 [95% confidence interval, 1.99-16.16]), indoor obstacle course test (incidence rate ratio, 3.72 [95% confidence interval, 1.25-11.10]), and basketball (incidence rate ratio, 2.42 [95% confidence interval, 1.05-5.59]). Conclusion We found little gender difference in the overall risk of an anterior cruciate ligament tear; however, there were gender differences in injury rates when specific sports and activities were compared and when male-only sports were removed from the overall rate assessment.

Purpose While targeted inhibitors of tyrosine kinase activity demonstrate dramatic efficacy in the majority of patients with advanced gastrointestinal stromal tumors (GISTs), cure remains elusive and resistance to systemic therapy is a challenge. To assess the role of surgery in multimodality management of GISTs, we studied postoperative outcomes in patients treated with targeted kinase inhibitors for advanced GIST. Methods We evaluated outcomes in a single institution series of 69 consecutive patients who underwent surgery for advanced GISTs while receiving kinase inhibitors. Patients were categorized based on extent of disease before surgery (stable disease, limited disease progression, generalized disease progression) and surgical result (no evidence of disease, minimal residual disease, bulky residual disease). Results Disease status before surgery was associated with surgical result (P < .0001; median follow-up, 14.6 months). After surgery, there was no evidence of disease in 78%, 25%, and 7% of patients with stable disease, limited progression, and generalized progression, respectively. Bulky residual disease remained after surgery in 4%, 16%, and 43% of the patients with stable disease, limited progression, and generalized progression. Twelve-month progression-free survival was 80%, 33%, and 0% for patients with stable disease, limited progression, and generalized progression (P < .0001). Twelve-month overall survival was 95%, 86%, and 0% for patients with stable disease, limited progression, and generalized progression (P < .0001). Conclusion Patients with advanced GISTs exhibiting stable disease or limited progression on kinase inhibitor therapy have prolonged overall survival after debulking procedures. Surgery has little to offer in the setting of generalized progression.

Hypothesis An inexpensive and widely applicable technique to monitor recurrent laryngeal nerve (RLN) function during thyroid surgery can be safely implemented. Design Consecutive sample. Setting Single-surgeon academic practice. Patients Three hundred sixty-three consecutive patients undergoing surgery for thyroid disease in the 18 months from November 1, 1999, to May 31, 2001. Interventions Anesthetic management using laryngeal mask airway and spontaneous ventilation, combined with electrical RLN stimulation and fiberoptic video laryngoscopy to confirm vocal cord response. Main Outcome Measures Vocal cord response to RLN stimulation, intraoperative anatomic findings, postoperative voice quality, and anesthetic complications. Results We used the laryngeal mask airway–based technique in 327 cases. Visualization of vocal cords was maintained throughout the surgery in 310 cases (95%). In 10 cases (3%), the branch of the RLN carrying vocal cord function could not be identified until electrical testing was performed. A single inadvertent RLN palsy was seen in 1 of the 17 cases in which vocal cord visualization was lost during the procedure (0.03% overall). Upper airway obstruction occurred in 16 (5%) of 327 attempted procedures, requiring tracheal intubation in 3 (1%). No further complications regarding airway management were seen. Pneumothorax was observed in 5 cases (2%), each of which resolved without chest tube placement. Conclusions This technique can be applied to thyroid surgery as a safe means of managing the airway. It is associated with an ability to test RLN function at will in more than 95% of cases using readily available equipment.

Watson’s syndrome is an uncommon genetic disorder whose features include mental retardation and pulmonary valvular stenosis. The purpose of this report is to describe one management strategy used successfully to anaesthetize a woman with this disorder who presented for Caesarean section. Epidural anaesthesia using 0.5% bupivacaine without epinephrine in 2–3 ml boluses to a total dose of 15 ml was administered over 30 min. Invasive haemodynamic monitoring in the form of arterial and central venous catheters were used to guide therapy and help ensure maternal and fetal well-being. Intravenous ketamine in doses of 10–20 mg every five minutes to a total dose of 245 mg (4.5 mg · kg−1) was used to overcome the patient’s uncooperative nature and facilitate invasive procedures. Postoperative analgesia was provided using 3 mg epidural morphine. The patient was observed in the intensive care unit for the first postoperative day and experienced an uncomplicated intra- and postoperative course. We conclude that this technique represents a safe and effective method for anaesthetizing patients with this complicated problem for Caesarean section.