Beach-Chair Versus Lateral Decubitus Positioning for Primary Arthroscopic Anterior Shoulder Stabilization: A Consecutive Series of 641 Shoulders.

BACKGROUND: There are limited data comparing the beach-chair (BC) versus lateral decubitus (LD) position for arthroscopic anterior shoulder stabilization. PURPOSE: To identify predictors of instability recurrence and revision after anterior shoulder stabilization and evaluate surgical position and glenoid bone loss as independent predictors of recurrence and revision at short- and midterm follow-ups. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A consecutive series of 641 arthroscopic anterior stabilization procedures were performed from 2005 to 2019. All shoulders were evaluated for glenohumeral bone loss on magnetic resonance imaging. The primary outcomes of interest were recurrence and revision. Multivariable logistic regression models were used to assess the relationships of outcomes with age, position, glenoid bone loss group, and track. RESULTS: A total of 641 shoulders with a mean age of 22.3 years (SD, 4.45 years) underwent stabilization and were followed for a mean of 6 years. The overall 1-year recurrent instability rate was 3.3% (21/641) and the revision rate was 2.8% (18/641). At 1 year, recurrence was observed in 2.3% (11/487) and 6.5% (10/154) of BC and LD shoulders, respectively. The 5-year recurrence and revision rates were 15.7% (60/383) and 12.8% (49/383), respectively. At 5 years, recurrence was observed in 16.4% (48/293) and 13.3% (12/90) of BC and LD shoulders, respectively. Multivariable modeling demonstrated that surgical position was not associated with a risk of recurrence after 1 year (odds ratio [OR] for LD vs BC, 1.39; P = .56) and 5 years (OR for LD vs BC, 1.32; P = .43), although younger age at index surgery was associated with a higher risk of instability recurrence (OR, 1.73 per SD [4.1 years] decrease in age; P < .03). After 1 and 5 years, surgical position results were similar in a separate multivariable logistic regression model of revision surgery as the dependent variable, when adjusted for age, surgical position, bone loss group, and track. At 5 years, younger age was an independent risk factor for revision: OR 1.68 per SD (4.1 years) decrease in age (P < .05). CONCLUSION: Among fellowship-trained orthopaedic surgeons, there was no difference in rates of recurrence and revision surgery after performing arthroscopic anterior stabilization in either the BC or the LD position at 1- and 5-year follow-ups. In multivariable analysis, younger age, but not surgical position, was an independent risk factor for recurrence.

Minimally Invasive Distal Biceps Tendon Reconstruction With Semitendinosus Allograft and Dual Unicortical Button Fixation.

Complete rupture of the distal biceps tendon is routinely treated with direct repair; however, chronic, mid-substance, or musculotendinous tears are challenging clinical scenarios for surgeons. Although attempts at direct repair should be considered, in cases of severe retraction or tendon deficiency, a reconstruction may be warranted. Herein the authors describe a technique for distal biceps reconstruction using allograft with a Pulvertaft weave via a standard anterior incision, similar to primary repair, with a small catchment incision more proximally for tendon retrieval. Use of this technique with dual unicortical buttons allows for early range of motion, restoration of the distal footprint, and improved biomechanical construct strength, which has proven invaluable in a population of elite and highly active military servicemembers.

Improving visualization in shoulder arthroscopy.

Arthroscopic shoulder procedures are one of the most common procedures used to restore function through minimally invasive techniques. With the demand for shoulder arthroscopic procedures comes the need for safe, effective, and efficient surgery that maximizes patient outcomes while minimizing complications. Many variables contribute to visualization in shoulder arthroscopy including vascular anatomy, blood pressure control, arthroscopic pump systems, turbulence control, epinephrine, and tranexamic acid. Furthermore, patient positioning can have a dramatic effect on visualization with both the beach chair position and lateral decubitus positioning having various strengths and weaknesses depending on the intended procedure being performed. The purpose of this review is to examine the benefits and complications reported in the literature for improving visualization in shoulder arthroscopy.

Prospective Evaluation of Posterior Glenoid Bone Loss After First-time and Recurrent Posterior Glenohumeral Instability Events.

BACKGROUND: Although posterior glenohumeral instability is becoming an increasingly recognized cause of shoulder pain, the role of posterior glenoid bone loss on outcomes remains incompletely understood. PURPOSES: To prospectively determine the amount of bone loss associated with posterior instability events and to determine predisposing factors based on preinstability imaging. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 1428 shoulders were evaluated prospectively for ≥4 years. At baseline, a subjective history of shoulder instability was ascertained for each patient, and bilateral noncontrast magnetic resonance imaging (MRI) scans of the shoulders were obtained 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 MRI scans were obtained and compared with the screening MRI scans. Glenoid version, perfect-circle-based bone loss was measured for each patient's pre- and postinjury MRI scans using previously described methods. RESULTS: Of the 1428 shoulders that were prospectively followed, 10 shoulders sustained a first-time posterior instability event and 3 shoulders sustained a recurrent posterior instability event. At baseline, 11 of 13 shoulders had some amount of glenoid dysplasia and/or bone loss. The change in glenoid bone loss was 5.4% along the axis of greatest loss (95% CI, 3.8%-7.0%; P = .009), 4.4% at the glenoid equator (95% CI, 2.7%-6.2%; P = .016), and 4.2% of total glenoid area (95% CI, 2.9%-5.3%; P = .002). Recurrent glenoid instability was associated with a greater amount of absolute bone loss along the axis of greatest loss compared with first-time instability (recurrent: 16.8% ± 1.1%; 95% CI, 14.6%-18.9%; first-time: 10.0% ± 1.5%; 95% CI, 7.0%-13.0%; P = .005). Baseline glenoid retroversion ≥10° was associated with a significantly greater percentage of bone loss along the axis of greatest loss (≥10° of retroversion: 13.5% ± 2.0%; 95% CI, 9.6%-17.4%; <10° of retroversion: 8.5% ± 0.8%; 95% CI, 7.0%-10.0%; P = .045). CONCLUSIONS: Posterior glenohumeral instability events were associated with glenoid bone loss of 5%. The amount of glenoid bone loss after a recurrent posterior glenohumeral instability event was greater than that after first-time instability. Glenoid retroversion ≥10° was associated with a greater amount of posterior glenoid bone loss after a posterior instability event.

Efficacy of Vancomycin Powder in Mitigating Infection of Open Penetrating Trauma Wounds on the Battlefield: An Evidence-Based Review.

BACKGROUND: Open penetrating trauma wounds to the extremities remain the most common injuries encountered in combat and are frequently complicated by bacterial infections. These infections place a heavy burden on the Servicemember and the healthcare system as they often require multiple additional procedures and can frequently cause substantial debility. Previous studies have shown that vancomycin powder has demonstrated efficacy in decreasing infection risks in clean and contaminated orthopedic surgical wounds. METHODS: This review evaluates the most prevalent organisms cultured post-trauma, the current Tactical Combat Casualty Care (TCCC) guidelines for antibiotic prophylaxis, and relevant research of vancomycin's prophylactic use. RESULTS: Results from previous studies have shown a time-dependent reduction in bacterial load when vancomycin powder is introduced early post injury in traumatic orthopedic wounds. Furthermore, perioperative application affords a cost-effective method to prevent infection with minimal adverse effects. DISCUSSION: The current TCCC guidelines advocate for the use of antibiotics at the point of injury. When vancomycin powder is used in synergy with these guidelines, it can contribute a timely and powerful antibiotic to prevent infection. CONCLUSION: The prophylactic use of vancomycin powder is a promising adjunctive agent to current Clinical Practice Guidelines (CPG), but it cannot be conclusively determined to be effective without further research into its application in traumatic combat wounds.

On-field Emergencies and Emergency Action Plans.

Sideline coverage can be an enjoyable experience and provide the opportunity to witness and evaluate an athlete's pathology at the time of injury. While the majority of on-field injury will likely be of low acuity, it is essential to develop an Emergency Action Plan (EAP) to deliver excellent medical care efficiently. The EAP should provide a written, standardized multidisciplinary approach involving key personnel. The EAP should be rehearsed on at least an annual basis and should highlight the initial assessment of the patient while also accounting for the various types of trauma that may occur on the field and appropriate field extrication procedures. As most players who have a true on-field emergency will not return to same-day play, a thorough understanding of how to deliver emergency care and transfer the player to a higher level of care is essential.

Meniscal Allograft Transplantation.

Meniscal allograft transplantation provides treatment options for patients with a meniscus-deficient knee with lifestyle-limiting symptoms in the absence of advanced degenerative changes. Meniscal transplantation helps to restore the native biomechanics of the involved knee, which may provide chondroprotective effects and restoring additional knee stability. Improvements in pain, function, and activity level have been seen in appropriately selected patients undergoing transplantation. Although various surgical implantation options exist, the majority focus on reproducing native attachments of the meniscal roots to allow near normal mechanics. Although meniscal transplantation may serve as a salvage procedure for symptomatic patients with a meniscus-deficient knee, it may prevent or delay the necessity of a more invasive arthroplasty procedure.

Recurrent Instability and Surgery Are Common After Nonoperative Treatment of Posterior Glenohumeral Instability in NCAA Division I FBS Football Players.

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.

Lateral External-fixation Adjacent to Radial Nerve.

Introduction The aim of our study was to describe the injury pattern and outcomes of active-duty subjects that underwent humeral external fixation and to determine if the placement of external fixator pins outside of the radial nerve safe zones is correlated with injury to the radial nerve. Materials and methods We examined all US Service members treated with humeral external fixation at our facility from June 2005 through June 2015. The mechanism of injury, injury pattern, location of external fixation application, pre- and postoperative radial nerve function, presence or absence of radial nerve transection from injury or external fixation, anatomic location of pins in relation to the radial nerve safe zone, and final radial nerve outcomes were recorded. We defined the proximal safe zone as 5 cm distal to the acromion to 14.8 cm proximal to the lateral epicondyle, and we defined the distal safe zone as the proximal 70% of the transepicondylar width of the humerus when projected proximally from the lateral epicondyle. Results  For our study, 123 patients were identified over our date range, and 16 subjects were included with documentation regarding nerve function/injury characteristics, appropriate radiographs, and active duty status. Around 80% of injuries resulted from a blast mechanism, and 80% of injury patterns included either an intraarticular or open fracture. The radial nerve safe zone was violated in 15 of the 16 subjects (94%). The one subject with a safe construct did not sustain a nerve injury. Complete preoperative documentation on nerve function was only available for half of the subjects. Two of five subjects known to have intact function prior to external fixation had a postoperative neurologic deficit (40%). Of eight subjects with unknown radial nerve function prior to external fixation, seven subjects had full nerve function at the final follow up, and one subject had partial sensory function only. Of the three subjects with impaired preoperative radial nerve function, two made a full recovery, and the third recovered sensory function only. Around 50% of all subjects required medical retirement. Conclusion External fixation of upper extremity injuries in combat is rarely absolutely indicated, often results in the placement of pins outside of the radial nerve safe zone, and is associated with up to a 40% incidence of radial nerve injury.

The Burden of Meniscus Injury in Young and Physically Active Populations.

Meniscus injuries affect the young and physically active population. Although meniscus injuries are common in many sports, football, soccer, basketball, and wrestling are associated with the greatest risk. In an occupational setting, jobs requiring kneeling, squatting, and increased physical activity level have the greatest risk. Meniscus injury can be isolated to the meniscus or associated with other concomitant injuries, including anterior cruciate ligament tears and tibial plateau fractures. The frequency of meniscal repair is increasing because of a better understanding of meniscal pathophysiology, technological advancements, and a focus on meniscal preservation following injury to mitigate long-term consequences such as osteoarthritis.

Increased Glenoid Retroversion Is Associated With Increased Rotator Cuff Strength in the Shoulder.

BACKGROUND: The rotator cuff muscles are critical secondary stabilizers in the shoulder. Increased glenoid retroversion and rotator cuff strength have been associated with the risk of posterior shoulder instability; however, the effect of increased glenoid retroversion on rotator cuff strength remains unclear. PURPOSE/HYPOTHESIS: The purpose was to examine the association between glenoid version and rotator cuff strength in the shoulder in a young and healthy population with no history of shoulder instability. The hypothesis was that increased glenoid retroversion would be associated with increases in rotator cuff muscle strength. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A prospective cohort study was conducted over a 4-year period within a high-risk population to identify the risk factors for shoulder instability. Analyzed participants included 574 freshmen entering a United States service academy. Baseline data collected upon entry into the study included magnetic resonance imaging measurements of glenoid version. Rotator cuff strength was also assessed at baseline using a handheld dynamometer. Internal and external rotation strength were assessed with the glenohumeral joint positioned in neutral and in 45° of abduction. The current study represents an analysis of the baseline data from this cohort. RESULTS: The mean age, height, and weight of participants was 18.77 ± 0.97 years, 176.81 ± 8.48 cm, and 73.80 ± 12.45 kg, respectively. The mean glenoid version at baseline was 7.79°± 4.85° of retroversion. Univariate linear regression analyses demonstrated that increased glenoid retroversion was associated with increased internal and external rotation strength of the rotator cuff in neutral and 45° of abduction (P < .001). Similar results were observed in multivariable models controlling for important confounding variables. CONCLUSION: The results of this study demonstrate that as glenoid retroversion increases, internal and external rotation strength of the rotator cuff also increase in a young and healthy athletic population. These compensatory changes may contribute to increased glenohumeral dynamic stability in the presence of worse static stability with increasing retroversion.

The Role of CT Angiography in Evaluating Lower Extremity Trauma: 157 Patient Case Series at a Military Treatment Facility.

INTRODUCTION: Physical exam and angiography have important roles in the diagnosis of traumatic lower extremity vascular injury with similar reported high rates of sensitivity and specificity. It has been previously shown that CTA is not universally indicated in the setting of acute lower extremity trauma when a reliable physical examination is obtained. As such, the purpose of this study was to determine if obtaining a CTA following physical examination altered the clinical care of patients following high-energy lower extremity trauma and the generalizability to the military population. MATERIALS AND METHODS: Retrospective review of all patients who underwent lower extremity CTA during the initial trauma evaluation at a Level 1 Trauma Center from 2007 to 2014. RESULTS: One hundred and fifty-seven patients met inclusion criteria. One hundred and seventeen patient's initial physical exam excluded limb ischemia with 67 vascular injuries on CTA (9 underwent angiogram in the OR) with no reperfusions required. 40 patients had hard signs of ischemia or ABI's <0.90, 29 had injuries on CTA, and fifteen underwent a vascular reperfusion procedure for acute vascular injury. Ten of 15 reperfusions required no further angiography after CTA. The sensitivity and negative predictive value of physical exam for needed reperfusion were both 100%. There were no instances of missed vascular injury or readmission and 53 patients were discharged directly from the emergency room after a negative CTA. CONCLUSIONS: This study suggests that physical exam alone achieves a high sensitivity for vascular injury in lower extremity trauma. Physical exam excluded all lower extremity ischemia without the need for advanced imaging. While CTA was useful to confirm and localize the source of acute vascular injury, the majority of vascular injuries identified on CTA did not affect immediate clinical care and lead to additional unnecessary procedures. However, in patients with suspected vascular injury, a negative CTA was also used as rationale for immediate discharge from the emergency department without further clinical observation. When applied to the deployed military setting the results of this study support the use of physical exam to accurately diagnose limb threatening ischemia at the time of injury or Role 1 facilities with CTA reserved for diagnosing the level of the vascular injury and for potential patient clearance prior to prolonged evacuation.

Topical rifampin powder for orthopaedic trauma part II: Topical rifampin allows for spontaneous bone healing in sterile and contaminated wounds.

Infectious complications can reduce fracture healing rate. Broad spectrum antibiotics are commonly administered to prevent and treat musculoskeletal infections. Local antibiotics are applied to the wound site to increase therapeutic concentrations without increasing systemic toxicity, however, may hinder local tissue recovery. Rifampin has been shown to eradicate mature Staphylococcal biofilms and its use proven for treating musculoskeletal infections. In this study, a spontaneously healing defect model in a rat was used to investigate the impact rifampin powder has on endogenous bone healing in both a sterile and contaminated wound. No significant differences were identified in bone volume fraction via microcomputed tomography, radiological scoring, or histology between an empty defect and animals that received vancomycin or rifampin powder in a sterile wound. When applied to a contaminated musculoskeletal wound, the rifampin powder had significantly greater bone formation compared to the control, as measured by microcomputed tomography, plain radiology, and histology. In addition, the animals treated with rifampin powder had reduced bacteria, reduced white blood cell count and reduced number of clinical indications of infection. Interestingly, while the vancomycin group still displayed signs of infection via quantitative microbiology, plain radiology, and histology, there was significant bone formation within the defect and reduction of systemic signs of infection. We demonstrated that the use of rifampin powder allows bone to heal in both a sterile and contaminated model of musculoskeletal infection. To our knowledge, this is the first time the direct impact of local antibiotics on bone healing has been investigated. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 36:3142-3150, 2018.

Settable polymer/ceramic composite bone grafts stabilize weight-bearing tibial plateau slot defects and integrate with host bone in an ovine model.

Bone fractures at weight-bearing sites are challenging to treat due to the difficulty in maintaining articular congruency. An ideal biomaterial for fracture repair near articulating joints sets rapidly after implantation, stabilizes the fracture with minimal rigid implants, stimulates new bone formation, and remodels at a rate that maintains osseous integrity. Consequently, the design of biomaterials that mechanically stabilize fractures while remodeling to form new bone is an unmet challenge in bone tissue engineering. In this study, we investigated remodeling of resorbable bone cements in a stringent model of mechanically loaded tibial plateau defects in sheep. Nanocrystalline hydroxyapatite-poly(ester urethane) (nHA-PEUR) hybrid polymers were augmented with either ceramic granules (85% ß-tricalcium phosphate/15% hydroxyapatite, CG) or a blend of CG and bioactive glass (BG) particles to form a settable bone cement. The initial compressive strength and fatigue properties of the cements were comparable to those of non-resorbable poly(methyl methacrylate) bone cement. In animals that tolerated the initial few weeks of early weight-bearing, CG/nHA-PEUR cements mechanically stabilized the tibial plateau defects and remodeled to form new bone at 16 weeks. In contrast, cements incorporating BG particles resorbed with fibrous tissue filling the defect. Furthermore, CG/nHA-PEUR cements remodeled significantly faster at the full weight-bearing tibial plateau site compared to the mechanically protected femoral condyle site in the same animal. These findings are the first to report a settable bone cement that remodels to form new bone while providing mechanical stability in a stringent large animal model of weight-bearing bone defects near an articulating joint.

Topical rifampin powder for orthopedic trauma part I: Rifampin powder reduces recalcitrant infection in a delayed treatment musculoskeletal trauma model.

Open fractures become infected despite meticulous debridement and care. Locally applied antibiotics, commonly embedded in polymethylmethacrylate, deliver high doses of drug directly to the fracture site. Direct application of antibiotic powder, which is being applied prophylactically in spine surgery, is a recent interest in the trauma sector, where bacterial biofilms are more prevalent. Traditional antibiotics, such as vancomycin, are poor performers against bacterial biofilms thus are ineffective in delayed treatment. Rifampin is an effective eradicator of Staphylococcal biofilms. Here, a rat model of musculoskeletal trauma was used to evaluate the utility of locally applied rifampin powder for reducing established orthopedic Staphylococcal infections in a delayed treatment scenario that previously indicated the limited use of local vancomycin. By applying rifampin powder directly to the contaminated segmental defect, the number of bacteria, as well as clinical indications of infection, were significantly reduced compared to vancomycin and daptomycin. Considering the Infectious Disease Society of America's recommendation to use rifampin in combination with another antibiotic to reduce the onset of rifampin resistance, rifampin powder was also applied in combination with vancomycin or daptomycin with insignificant changes in eradication performance. No indications of rifampin resistance were identified. Clinical Significance: The use of locally applied rifampin is a promising therapy for mature and tolerant musculoskeletal infections. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 36:3136-3141, 2018.

Characterization of disability following traumatic through knee and transfemoral amputations.

INTRODUCTION: The purpose of this study is to characterize through knee and transfemoral amputations following severe traumatic injuries. METHODS: A retrospective review of all transfemoral and through knee amputations sustained by United States military service members from 1 October 2001 to 30 July 2011 was conducted. Data from the Department of Defense Trauma Registry, the Armed Forces Health Longitudinal Technology Application, inpatient medical records and the Physical Evaluation Board Liaison Offices were queried in order to obtain characteristics related to injury sustained, demographics, treatment, and disability/mental health outcome data. RESULTS: A total of 1631 amputations in 1315 patients were identified. Of these there were 37 through knee and 296 were transfemoral amputations. Adequate records for detailed analysis were available on 140 and 25 transfemoral and through knee amputations respectively. There were no significant differences in demographic information, injury mechanism, initial injury severity score, or associated injuries, to include contralateral amputations. There was no significant difference in average disability rating (67.9% vs 78.3%, p = 0.46) or number of service members determined to be fully disabled (42.2% vs 28.6% p = 0.33) between the transfemoral and through knee amputation groups. Whereas there was no difference between groups preoperatively, the knee disarticulation group displayed a higher rate of mental health diagnoses post-amputation (96% vs 72%, p < 0.001) and a higher preponderance of anxiety related disorders than the transfemoral amputees (26.92% vs 12.96%, p = 0.0129). DISCUSSION/CONCLUSION: Among this military amputee through knee and transfemoral amputees displayed similar physical disability profiles. However, the through knee amputees displayed a higher level of anxiety related disorders and mental health diagnosis overall. While we don't believe this relationship to be causal in nature, this finding reflects the importance of paying particular attention to mental health in the final disposition of traumatic lower extremity amputees.

Local control of polymicrobial infections via a dual antibiotic delivery system.

BACKGROUND: Contaminated traumatic open orthopedic wounds are frequently complicated by polymicrobial contamination and infection. In high-risk wounds, the standard of care comprises debridement and irrigation combined with antibiotics which can be applied directly or combined with systemic antibiotics. Recently, bioabsorbable chitosan sponges have been shown to be an effective single-agent delivery device for local antibiotics with and without negative pressure wound therapy (NPWT). Severely contaminated orthopedic wounds, however, are often complicated by polymicrobial infections, necessitating multiple antibiotic agents. As such, the purpose of this study was to determine if a chitosan sponge would provide a suitable delivery vehicle for multiple antibiotics for the treatment of a polymicrobial infection in a large animal polytraumatic extremity wound model. METHODS: A complex polytraumatic extremity wound was created in 11 adult male Boer goats. Each wound was contaminated with a bioluminescent strain of S. aureus (1 ml of 108 colony forming units/ml) and of P. aeruginosa (1 ml of 108 CFU/ml) which are genetically engineered to allow quantification with a photon-counting camera. Six hours following initial wound creation and contamination, wounds were debrided and irrigated with low-pressure normal saline. The animals were randomized into one of two treatments: wet-to-dry dressings alone or a commercially available chitosan sponge loaded with 1 g vancomycin and 1.2 g of tobramycin. Each animal was then recovered and reimaged 48 h later for total bacteria content; tissue samples were taken from the wound bed to determine relative bacterial colonization. RESULTS: All animals in the chitosan sponge group saw significant reductions in overall bacterial load of S. aureus and P. aeruginosa (p = 0.001). The bioluminescence was also significantly reduced compared to the wet-to-dry dressing group (p = 0.0001). Furthermore, whereas the antibiotic sponge group displayed near complete eradication of bacteria, the wounds treated with the wet-to-dry dressings alone displayed a significant 2-log increase in total bacteria at 48 h p = 0.0001). S. aureus was the predominant species found in the wounds, comprising 95 and 99% of all bacteria found in the chitosan sponge and wet-to-dry, respectively. CONCLUSION: Dual antimicrobial therapy loaded in a chitosan sponge is an effective way to reduce polymicrobial infections traumatic extremity wound.

Blood Flow Restriction Training After Achilles Tendon Rupture.

Blood flow restriction (BFR) training is a technique shown to be safe and effective at increasing muscular strength and endurance in healthy fitness populations and is under study for its use in postinjury rehabilitation. BFR stimulates muscular strength and hypertrophy gains at much lower loads than traditional methods, allowing patients to begin the rehabilitation process much sooner. We report on 2 patients who incorporated BFR training into their traditional rehabilitation program after Achilles tendon ruptures. Patient 1 was a 29-year-old active duty soldier who sustained a left Achilles tendon rupture while playing competitive football. After operative repair and traditional rehabilitative measures, he was unable to ambulate without assistive devices owing to persistent weakness. The patient subsequently started a 5-week "return to run" program using BFR training. He experienced plantarflexion peak torque improvements of 522% and 108.9% and power gains of 4475% and 211% at 60°/s and 120°/s, respectively. He was able to ambulate without assistive devices at the 5-week follow-up examination. Patient 2 was a 38-year-old male soldier who experienced a complete left Achilles tendon rupture while exercising. After nonoperative treatment with an accelerated rehabilitation program, the patient still experienced significant strength and functional deficits. He was subsequently enrolled in a 6-week course of BFR training. He experienced plantarflexion strength improvements of 55.8% and 47.1% and power gains of 68.8% and 78.7% at 60°/s and 120°/s, respectively. He was able to return to running and sports on completion of 6 weeks of BFR-assisted therapy. Incorporating tourniquet-assisted blood flow restriction with rehabilitation programs can improve strength, endurance, and function after Achilles tendon rupture.

Mechanical Testing of Epiphysiodesis Screws.

Epiphysiodesis is performed to treat leg-length discrepancies and angular deformities in children. However, when placed across a physis to modulate growth, screws can bend or break postoperatively. This study evaluated the mechanical properties of 3 different screw designs commonly used when performing an epiphysiodesis. Six 4.0-mm cannulated, fully threaded; six 4.0-mm cannulated, partially threaded; and six 4.0-mm noncannulated, partially threaded cancellous screws underwent cantilever bending and tension testing in a simulated physis. All screws were tested in simulated cancellous bone foam blocks. All testing was performed using a servo-hydraulic testing machine to determine stiffness and ultimate load. For statistical analysis, one-way analysis of variance with Tukey's honestly significant difference test in post hoc analysis was used to assess significant differences among groups (P<.05). The noncannulated, partially threaded screws had a significantly lower stiffness than the 2 cannulated screw types in the tension test (P<.001) and bending test (P<.001). Additionally, the noncannulated, partially threaded screws had significantly higher ultimate load to failure than the 2 cannulated screw types in the tension test (P<.001) and the cannulated, partially threaded screws in the bending test (P=.045). The results indicate that noncannulated, partially threaded screws have a higher ultimate load capacity and are less stiff than both cannulated, partially threaded screws and cannulated, fully threaded screws. Surgeons should take into consideration that noncannulated, partially threaded screws are less likely to fail following epiphysiodesis. [Orthopedics. 2018; 41(2):e240-e244.].