What is the Case Volume of Orthopaedic Trauma Surgeons in the Military Health System? An Assessment of Wartime Readiness and Skills Sustainment.

INTRODUCTION: Complex, high-energy extremity trauma secondary to explosive mechanisms has been increasingly common in modern warfare, accounting for a majority of combat wounds throughout the conflicts in Iraq and Afghanistan. Fellowship-trained orthopaedic trauma surgeons treated many of these complex injuries; however, as the number of casualties continue to decrease during a period of relative peace, a growing concern over maintaining military trauma readiness exists. METHODS: The Military Health System Data Repository was queried for all Common Procedural Terminology (CPT) codes associated with 18 fellowship-trained orthopaedic trauma surgeons from 2013 to 2019. The codes were further analyzed and categorized based on common trauma subspecialty procedures such as fracture fixation of the pelvic ring, acetabulum, upper and lower extremity, peri-articular, and nonunion/malunion surgery. We used descriptive statistics to quantify both the average number of cases per surgeon per year in each of the subcategories and case volume among Military Treatment Facilities (MTFs) during the study period. RESULTS: We identified 7,769 CPT codes for surgical procedures throughout the study period. The most common surgical procedures performed were: removal of implant (n = 836, 11%), knee arthroscopy (n = 507, 7%), and debridement of devitalized tissue (n = 345, 4%). The total trauma subspecialty procedural codes and average cases per surgeon per year were as follows: pelvic ring (n = 54, <1 case/year), acetabulum (n = 90, 1 case/year), upper extremity (n = 1,314, 15 cases/year), lower extremity (n = 2,286, 25 cases/year), peri-articular (n = 675, 8 cases/year), and nonunion/malunion (n = 288, 3 cases/year). San Antonio Military Medical Center (SAMMC) accounted for the most fracture-related CPT codes overall (35%), while all other MTFs contributed approximately 10% or less of all fracture-related codes. CONCLUSIONS: These results highlight the lack of orthopaedic trauma volume at other MTFs outside of SAMMC, raising concern for maintaining military readiness during an inter-war period of relative peace. The DoD continues to make concerted efforts to maintain readiness through civilian partnerships and subsequently increase surgical case volume for military trauma surgeons. Future efforts should include an in-depth analysis of caseloads of military trauma surgeons providing care at both MTFs and civilian institutions to optimize preparedness in future conflicts.

Pure Superior Wall Acetabular Fracture: A Rare Posterior Wall Variant.

CASE: We present a case of a pure superior wall acetabular fracture in an US soldier, caused by a collapsing wall. Although Letournel and Judet classified this pattern as a rare variant of a posterior-superior wall acetabular fracture, it shares features of several patterns and the treatment more closely follows that of the anterior-based elementary patterns. CONCLUSION: The mechanism, incidence, and long-term outcomes of this fracture remain unknown, but improved recognition and proper classification may help to guide treatment. This case highlights 1 patient with this unique pattern and outlines its management and short- to mid-term outcome.

High Frequency Spectral Ultrasound Imaging Detects Early Heterotopic Ossification in Rodents.

Heterotopic ossification (HO) is a devastating condition in which ectopic bone forms inappropriately in soft tissues following traumatic injuries and orthopedic surgeries as a result of aberrant mesenchymal progenitor cell (MPC) differentiation. HO leads to chronic pain, decreased range of motion, and an overall decrease in quality of life. While several treatments have shown promise in animal models, all must be given during early stages of formation. Methods for early determination of whether and where endochondral ossification/soft tissue mineralization (HO anlagen) develop are lacking. At-risk patients are not identified sufficiently early in the process of MPC differentiation and soft tissue endochondral ossification for potential treatments to be effective. Hence, a critical need exists to develop technologies capable of detecting HO anlagen soon after trauma, when treatments are most effective. In this study, we investigate high frequency spectral ultrasound imaging (SUSI) as a noninvasive strategy to identify HO anlagen at early time points after injury. We show that by determining quantitative parameters based on tissue organization and structure, SUSI identifies HO anlagen as early as 1-week postinjury in a mouse model of burn/tenotomy and 3 days postinjury in a rat model of blast/amputation. We analyze single cell RNA sequencing profiles of the MPCs responsible for HO formation and show that the early tissue changes detected by SUSI match chondrogenic and osteogenic gene expression in this population. SUSI identifies sites of soft tissue endochondral ossification at early stages of HO formation so that effective intervention can be targeted when and where it is needed following trauma-induced injury. Furthermore, we characterize the chondrogenic to osteogenic transition that occurs in the MPCs during HO formation and correlate gene expression to SUSI detection of the HO anlagen.

Validation of PATHFx 2.0: An open-source tool for estimating survival in patients undergoing pathologic fracture fixation.

Treatment decisions in patients with metastatic bone disease rely on accurate survival estimation. We developed the original PATHFx models using expensive, proprietary software and now seek to provide a more cost-effective solution. Using open-source machine learning software to create PATHFx version 2.0, we asked whether PATHFx 2.0 could be created using open-source methods and externally validated in two unique patient populations. The training set of a well-characterized, database records of 189 patients and the bnlearn package within R Version 3.5.1 (R Foundation for Statistical Computing), was used to establish a series of Bayesian belief network models designed to predict survival at 1, 3, 6, 12, 18, and 24 months. Each was externally validated in both a Scandinavian (n = 815 patients) and a Japanese (n = 261 patients) data set. Brier scores and receiver operating characteristic curves to assessed discriminatory ability. Decision curve analysis (DCA) evaluated whether models should be used clinically. DCA showed that the model should be used clinically at all time points in the Scandinavian data set. For the 1-month time point, DCA of the Japanese data set suggested to expect better outcomes assuming all patients will survive greater than 1 month. Brier scores for each curve demonstrate that the models are accurate at each time point. Statement of Clinical Significance: we successfully transitioned to PATHFx 2.0 using open-source software and externally validated it in two unique patient populations, which can be used as a cost-effective option to guide surgical decisions in patients with metastatic bone disease.

The management of embedded metal fragment patients and the role of chelation Therapy: A workshop of the Department of Veterans Affairs-Walter Reed National Medical Center.

Exposure to retained metal fragments from war-related injuries can result in increased systemic metal concentrations, thereby posing potential health risks to target organs far from the site of injury. Given the large number of veterans who have retained fragments and the lack of clear guidance on how to medically manage these individuals, the Department of Veterans Affairs (VA) convened a meeting of chelation experts and clinicians who care for embedded fragment patients to discuss current practices and provide medical management guidance. Based on this group's clinical expertise and review of published literature, the evidence presented suggests that, at least in the case of lead fragments, short-term chelation therapy may be beneficial for embedded fragment patients experiencing acute symptoms associated with metal toxicity; however, in the absence of clinical symptoms or significantly elevated blood lead concentrations (greater than 80 µg/dL), chelation therapy may offer little to no benefit for individuals with retained fragments and pose greater risks due to remobilization of metals stored in bone and other soft tissues. The combination of periodic biomonitoring to assess metal body burden, longitudinal fragment imaging, and selective fragment removal when metal concentrations approach critical injury thresholds offers a more conservative management approach to caring for patients with embedded fragments.

Orthopaedic osseointegration: Implantology and future directions.

Osseointegration (OI) is the direct anchorage of a metal implant into bone, allowing for the connection of an external prosthesis to the skeleton. Osseointegration was first discovered in the 1960s based on the microscopic analysis of titanium implant placed into host bone. New bone was observed to attach directly to the metal surface. Following clinical investigations into dentistry applications, OI was adapted to treat extremity amputations. These bone anchored implants, which penetrate the skin and soft tissues, eliminate many of the challenges of conventional prosthetic sockets, such as poor fit and suspension, skin breakdown, and pain. Osseointegrated implants show promise to improve prosthesis use, pain, and function for amputees. The successful process of transcutaneous metal integration into host bone requires three synergistic systems: the host bone, the metal implant, and the skin-implant interface. All three systems must be optimized for successful incorporation and longevity of the implant. Osseointegration begins during surgical implantation of the metal components through a complex interplay of cellular mechanisms. While implants can vary in design-including the original screw, press fit implants, and compressive osseointegration-they face common challenges to successful integration and maintenance of fixation within the host bone. Overcoming these challenges requires the understanding of the complex interactions between each element of OI. This review outlines (a) the basic components of OI, (b) the science behind both the bone-implant and the skin-implant interfaces, (c) the current challenges of OI, and (d) future opportunities within the field.

Internal Fixation Versus Arthroplasty for the Treatment of Nondisplaced Femoral Neck Fractures in the Elderly: A Systematic Review and Meta-Analysis.

OBJECTIVE: To compare the outcomes of elderly patients with nondisplaced and minimally displaced femoral neck fractures treated with internal fixation versus arthroplasty. DATA SOURCES: A comprehensive search of the MEDLINE, Embase, and central databases was conducted through June 25, 2019. STUDY SELECTION: Studies were included if the sample population was (1) 60 years of age or older, (2) had nondisplaced or minimally displaced (Garden I or II) femoral neck fractures, and (3) if the study compared internal fixation versus arthroplasty. Only full-text English manuscripts were included. The primary outcome was reoperation. Secondary outcomes included mortality, patient-reported outcomes, length of hospital stay, infection, and blood transfusions. DATA EXTRACTION: Two authors independently extracted data from the included studies. Each study was independently evaluated for quality using the Cochrane risk of bias assessment. DATA SYNTHESIS: Of the 1597 identified articles, 4 manuscripts met the eligibility criteria with a total of 579 patients (236 treated with hemiarthroplasty and 343 treated with internal fixation). Patients treated with arthroplasty had a significantly lower risk of reoperation when compared with those treated with internal fixation [relative risk: 0.30 (95% CI, 0.16-0.55, P < 0.01)]. There was no significant difference detected in 1-year mortality risk between the 2 treatment groups. CONCLUSIONS: In elderly patients with nondisplaced and minimally displaced femoral neck fractures, treatment with hemiarthroplasty may reduce the relative risk of reoperation by 70% when compared with internal fixation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is PROMIS the new standard for patient-reported outcomes measures in orthopaedic trauma research?

This review describes some of the benefits of the Patient-Reported Outcomes Measurement Information System (PROMIS) architecture, determined how frequently PROMIS measures were used in the current orthopaedic trauma literature, and compared the features of PROMIS instruments with other frequently used patient-reported outcomes measures (PROMs). PROMIS instruments have several unique elements to their architecture, such as item response theory, computerized adaptive testing options, and scaling using T-scores, that differentiate the instruments from many other PROMs. Over the past five years, 108 different PROMs were reported in 319 studies published in high-impact orthopaedic journals. PROMIS measures, including PROMIS Physical Function, Pain Interference, and Upper Extremity Function, were only used in seven studies (2%). PROMIS measures were found to be comparable to other more common PROMs with respect to respondent burden, administration options, and psychometric assessments specific to fracture patients. Likely, the limited familiarity and interpretability of PROMIS measures in the fracture population remain the most substantial barriers to broader adoption in orthopaedic trauma research.

Incidence and Characteristics of Humeral Shaft Fractures After Subpectoral Biceps Tenodesis.

BACKGROUND: Biceps tenodesis is a procedure that can address biceps and labral pathology. While there is an increased risk of humeral fracture after biceps tenodesis, it has been described only in case reports. PURPOSE: To identify the incidence, demographics, and characteristics of humeral shaft fractures after biceps tenodesis. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The US Military Health System Data Repository was searched for patients with a Current Procedural Terminology code for biceps tenodesis between January 2013 and December 2016. The cohort of identified patients was then searched for those assigned a code for humeral fracture per the International Classification of Diseases, 9th Revision and 10th Revision. The electronic health records and radiographs of patients who were diagnosed with a humeral fracture were then evaluated to confirm that the fracture was related to the biceps tenodesis. Records were then reviewed for patient demographics, radiographs, operative reports, and clinical notes. RESULTS: A total of 15,085 biceps tenodeses were performed between January 2013 and December 2016. There were 11 postoperative and 1 intraoperative humeral fractures. The incidence of fracture was <0.1%. All fractures were extra-articular spiral fractures that propagated through the tenodesis site. Eight patients were treated with functional bracing, 3 with open reduction and internal fixation, and 1 with a soft tissue biceps tenodesis revision. Of 8 patients successfully treated nonoperatively, 6 regained full range of shoulder motion. Only 2 of the 4 patients who required operative treatment regained full range of shoulder motion. CONCLUSION: Humeral shaft fracture after biceps tenodesis is a rare complication that occurs in 7.9 out of 10,000 cases. Fractures occurred after various methods of fixation, including suture anchor, cortical button, and interference screw. Most patients were initially treated nonoperatively, and those who healed usually achieved full range of motion; however, those who required operative intervention often had restricted range of motion on final follow-up. Future studies should determine risk factors for fracture after biceps tenodesis.

Alternative Bone Graft Sources and Techniques for Tibiofibular Synostosis Creation Following Transtibial Amputation: A Report of Two Cases.

CASE: Alternative methods of the modified Ertl osteomyoplasty with use of two different tibial grafts for synostosis are presented in two patients who underwent revision transtibial amputation. CONCLUSION: These two techniques spare residual limb length relative to other described local techniques, avoid the morbidity of remote autograft harvest, and may be attempted in patients with inadequate residual limb lengths or in those who have tibiofibular length mismatch to achieve stable bridge synostosis.