Consensus and Equipose in the Management of Military Trainee Femoral Neck Stress Fractures: A Survey of Military Surgeons.

BACKGROUND: Femoral neck stress fractures (FNSFs) are a unique injury pattern not commonly treated in the civilian trauma population; however, it is particularly high with military trainees engaged in basic combat training. To date, no study has surveyed a population of military orthopedic surgeons on treatment preferences for military service members (SMs) with FNSF. QUESTIONS: We aim to evaluate the extent of clinical equipoise that exists in the management of these injuries, hypothesizing that there would be consensus in the factors dictating surgical and non-surgical intervention for FNSF. PATIENTS AND METHODS: A 27-question survey was created and sent to U.S. military orthopedic surgeon members of the Society of Military Orthopaedic Surgeons. The survey was designed in order to gather the experience among surgeons in treating FNSF and identifying variables that play a role in the treatment algorithm for these patients. In addition, seven detailed, clinical vignettes were presented to further inquire on surgeon treatment preferences. Binomial distribution analysis was used to evaluate for common trends within the surgeon's treatment preferences. RESULTS: Seventy orthopedic surgeons completed the survey, the majority of whom were on active duty status in the U.S. Military (82.86%) and having under 5 years of experience (61.43%). Majority of surgeons elected for a multiple screw construct (92.86%), however the orientation of the multiple screws was dependent on whether the fracture was open or closed. Management for compression-sided FNSF involving ≥50% of the femoral neck width, tension-sided FNSF, and stress fractures demonstrating fracture line progression had consensus for operative management. Respondents agreed upon prophylactic fixation of the contralateral hip if the following factors were involved: Complete fracture (98.57%), compression-sided fracture line >75% (88.57%), compression-sided fracture line >50-75% with hip effusion (88.57%), contralateral tension-sided fracture (87.14%), and compression-sided fracture line >50-75% (84.29%). An FNSF < 50% on the contralateral femoral neck or a hip effusion was indeterminate in surgeons indicating need for prophylactic fixation. Majority of surgeons (77.1%) utilized restricted toe-touch weight-bearing for postoperative mobility restrictions. CONCLUSIONS: Consensus exists for surgical and non-surgical management of FNSF by U.S. military orthopedic surgeons, despite the preponderance of surgeons reporting a low annual volume of FNSF cases treated. However, there are certain aspects in the operative and non-operative management of FNSF that are unanimously adhered to. Specifically, our results demonstrate that there is no clear indication on the management of FNSF when an associated hip effusion is involved. Additionally, the indications for surgically treating contralateral FNSF are unclear. LEVEL OF EVIDENCE: IV.

Understanding Noise Exposure During Cast Removal: The Effect of Cast Saw Type and Casting Material.

BACKGROUND: Cast removal can be associated with considerable noise exposure, especially impacting the pediatric patient and provider. Although noise generation from cast saws has been deemed safe by the U.S. Occupational Safety and Health Administration and the U.S. Centers for Disease Control and Prevention standards, there are no current studies on the effects of cast material on noise levels generated. METHODS: A simulated casting model utilizing plaster, fiberglass, and plaster with fiberglass overwrapping was used for experimental testing. Four different casting conditions were tested, with 5 samples in each group. Samples were tested using 2 different cast saws: a standard cast saw and a quiet saw. Each saw was used for 30 seconds of continuous cutting for each sample, measuring peak, mean, and minimum sound levels in decibels with sound level meters. Noise levels were measured at 18, 36, and 72 in (20, 91, and 183 cm) from the saw, comparing saw and cast types against ambient noise and baseline cast-saw noises. Between-group comparisons were performed using univariate analyses. RESULTS: Mean noise generation differed between casting materials, with plaster material demonstrating significantly greater noise levels than fiberglass casts at all distances for each saw type. Increasing fiberglass thickness significantly increased the mean noise levels with standard (18-in distance for 10 and 5 ply: 87.4 and 85.8 dB; p = 0.0004) and quiet cast saws (78.3 and 76.1 dB; p = 0.041. Additionally, the quiet cast saw provided a 5.7 to 10.6 dB reduction in mean and peak noise levels, varying by casting material and distance. CONCLUSIONS: Occupational noise exposure can be mitigated with the use of fiberglass casting material that is not >5 ply in thickness, with a quiet cast saw for removal. The use of a quiet cast saw substantially decreased noise exposure to patients and staff members over standard orthopaedic cast saws.

Surgically Treated Femoral Neck Stress Fractures Are Likely to Result in Military Separation During Basic Combat Training.

BACKGROUND: Femoral neck stress fractures are a common condition affecting military service members, most noticeably during basic combat training. Previous studies have investigated the risk factors for femoral neck stress fracture development in basic trainees and outcomes associated with treatment; however, few studies have focused on operatively treated femoral neck stress fracture in the military trainee. Doing so would be important not only for the military, but also providers caring for athletes, such as distance runners, who have a heightened risk for femoral neck stress fracture development. QUESTIONS/PURPOSES: (1) What proportion of US Army trainees completing basic combat training at Fort Jackson, SC, USA, who undergo surgery for femoral neck stress fracture during basic training subsequently leave military service because of the injury? (2) What factors are related to the patient or the fracture are associated with a higher likelihood of military separation? (3) What factors on the initial MRI are associated with progression of the stress fracture extent? METHODS: A retrospective study of a longitudinally maintained database of stress injuries involving basic combat trainees from a single military post was reviewed over a 3-year period. Inclusion criteria included basic trainees undergoing surgery for a femoral neck stress fracture between January 2018 and June 2020 with a minimum of 1-year follow-up. Surgery was indicated for service members with complete and tension-sided femoral neck stress fractures and those with high risk compression-sided stress fractures, generally representing fractures involving more than 50% of the femoral neck width. Over the study period, 57 service members (51% [29 of 57] women with a mean age of 24 years) underwent surgery for a femoral neck stress fracture, and all 57 had a minimum of 1-year follow-up. Identified service members underwent independent data collection including injury and radiographic parameters based on chart and imaging review. Documented fracture line progression on repeat imaging was present in 39% of service members, with a mean fracture line progression of 55% of the femoral neck width. Service members were subdivided based upon the ability to return to military service at 1 year. Univariate analysis was performed using patient and injury variables to identify factors associated with the ability to return to military service. RESULTS: Overall, 58% (33 of 57) of service members who had a femoral neck stress fracture treated surgically underwent military separation. A higher proportion of service members who demonstrated fracture line progression leading to surgical treatment remained in the military (58% [14 of 24] versus 30% [10 of 33]; odds ratio 0.3 [95% confidence interval (CI) 0.1 to 0.9]; p = 0.03). With the numbers available, we found no other patient- or fracture-related variables associated with military separation, although we suspect we may have been underpowered on some of these comparisons, in particular gender (61% [20 of 33] of individuals separated after surgery for this injury were women compared with 38% [9 of 24] who were retained; OR 2.6 [95% CI 0.9 to 7.56]; p = 0.09). The extent of osseous edema on T1-weighted imaging in association with a hip effusion demonstrated a significant positive correlation with final fracture percentage (r = 0.62; p = 0.003). CONCLUSION: Military service members with a femoral neck stress fracture initially managed nonoperatively but with progression of the fracture line requiring surgical intervention were more likely to return to military duties and complete basic combat training, suggesting that early diagnosis of femoral neck stress fractures may be associated with better functional recovery after surgical treatment. Additionally, the extent of the osseous edema on initial MRI T1-weighted imaging sequences may help predict the final extent of femoral neck stress fractures on repeat imaging. Further investigations should incorporate patient-reported outcomes and further explore factors associated with fracture progression and the inability to return to active duty or sport. LEVEL OF EVIDENCE: Level III, therapeutic study.

Femoral Neck Stress Fractures in Athletes and the Military.

➤: Femoral neck stress fractures (FNSFs) are an infrequent condition in athletic and military populations. ➤: A high index of suspicion with liberal use of magnetic resonance imaging (MRI) is vital for early recognition and treatment initiation. ➤: An associated hip effusion on MRI is a risk factor for an evolving stress injury and requires close assessment and consideration for repeat MRI. ➤: Stress reactions and stable, incomplete FNSFs (<50% of femoral neck width) can be treated nonsurgically. ➤: Surgical intervention is accepted for high-risk, incomplete (≥50% of femoral neck width), and complete FNSFs. ➤: Overall, there is a paucity of high-quality literature on the rates of return to activity following FNSF.

Volar DRUJ Instability After Midshaft Both-Bone Forearm Fracture in a Toddler: A Case Report.

CASE: A 2.5-year-old male child presented to the clinic for evaluation of left wrist popping. Ten months earlier, he sustained a closed left both-bone forearm fracture (BBFF) treated with reduction and casting. His clinical course was complicated by redisplacement requiring secondary manipulation and casting before osseous union. His parents reported wrist popping with active motion in the setting of a 20° apex volar malunion of the midshaft radius. He has been treated with observation and monitoring of deformity remodeling. CONCLUSION: Distal radioulnar joint instability is a potential complication of malunited BBFF, even in a pediatric population. Residual deformity, especially in the radius, should prompt clinical follow-ups after osseous union to assess functional recovery and deformity remodeling.

The cyclophilin inhibitor NIM-811 increases muscle cell survival with hypoxia in vitro and improves gait performance following ischemia-reperfusion in vivo.

Acute ischemia-reperfusion injury in skeletal muscle is a significant clinical concern in the trauma setting. The mitochondrial permeability transition inhibitor NIM-811 has previously been shown to reduce ischemic injury in the liver and kidney. The effects of this treatment on skeletal muscle are, however, not well understood. We first used an in vitro model of muscle cell ischemia in which primary human skeletal myoblasts were exposed to hypoxic conditions (1% O2 and 5% CO2) for 6 h. Cells were treated with NIM-811 (0-20 µM). MTS assay was used to quantify cell survival and LDH assay to quantify cytotoxicity 2 h after treatment. Results indicate that NIM-811 treatment of ischemic myotubes significantly increased cell survival and decreased LDH in a dose-dependent manner. We then examined NIM-811 effects in vivo using orthodontic rubber bands (ORBs) for 90 min of single hindlimb ischemia. Mice received vehicle or NIM-811 (10 mg/kg BW) 10 min before reperfusion and 3 h later. Ischemia and reperfusion were monitored using laser speckle imaging. In vivo data demonstrate that mice treated with NIM-811 showed increased gait speed and improved Tarlov scores compared to vehicle-treated mice. The ischemic limbs of female mice treated with NIM-811 showed significantly lower levels of MCP-1, IL-23, IL-6, and IL-1α compared to limbs of vehicle-treated mice. Similarly, male mice treated with NIM-811 showed significantly lower levels of MCP-1 and IL-1a. These findings are clinically relevant as MCP-1, IL-23, IL-6, and IL-1α are all pro-inflammatory factors that are thought to contribute directly to tissue damage after ischemic injury. Results from the in vitro and in vivo experiments suggest that NIM-811 and possibly other mitochondrial permeability transition inhibitors may be effective for improving skeletal muscle salvage and survival after ischemia-reperfusion injury.

Function of microRNAs in the Osteogenic Differentiation and Therapeutic Application of Adipose-Derived Stem Cells (ASCs).

Traumatic wounds with segmental bone defects represent substantial reconstructive challenges. Autologous bone grafting is considered the gold standard for surgical treatment in many cases, but donor site morbidity and associated post-operative complications remain a concern. Advances in regenerative techniques utilizing mesenchymal stem cell populations from bone and adipose tissue have opened the door to improving bone repair in the limbs, spine, and craniofacial skeleton. The widespread availability, ease of extraction, and lack of immunogenicity have made adipose-derived stem cells (ASCs) particularly attractive as a stem cell source for regenerative strategies. Recently it has been shown that small, non-coding miRNAs are involved in the osteogenic differentiation of ASCs. Specifically, microRNAs such as miR-17, miR-23a, and miR-31 are expressed during the osteogenic differentiation of ASCs, and appear to play a role in inhibiting various steps in bone morphogenetic protein-2 (BMP2) mediated osteogenesis. Importantly, a number of microRNAs including miR-17 and miR-31 that act to attenuate the osteogenic differentiation of ASCs are themselves stimulated by transforming growth factor ß-1 (TGFß-1). In addition, transforming growth factor ß-1 is also known to suppress the expression of microRNAs involved in myogenic differentiation. These data suggest that preconditioning strategies to reduce TGFß-1 activity in ASCs may improve the therapeutic potential of ASCs for musculoskeletal application. Moreover, these findings support the isolation of ASCs from subcutaneous fat depots that tend to have low endogenous levels of TGFß-1 expression.

Heterotopic ossification in complex orthopaedic combat wounds: quantification and characterization of osteogenic precursor cell activity in traumatized muscle.

BACKGROUND: Heterotopic ossification frequently develops following high-energy blast injuries sustained in modern warfare. We hypothesized that differences in the population of progenitor cells present in a wound would correlate with the subsequent formation of heterotopic ossification. METHODS: We obtained muscle biopsy specimens from military service members who had sustained high-energy wartime injuries and from patients undergoing harvest of a hamstring tendon autograft. Plastic-adherent cells were isolated in single-cell suspension and plated to assess the prevalence of colony-forming cells. Phenotypic characteristics were assessed with use of flow cytometry. Individual colony-forming units were counted after an incubation period of seven to ten days, and replicate cultures were incubated in lineage-specific induction media. Immunohistochemical staining was then performed to determine the percentage of colonies that had differentiated along an osteogenic lineage. Quantitative real-time reverse-transcription polymerase chain reaction was used to identify changes in osteogenic gene expression. RESULTS: Injured patients had significantly higher numbers of muscle-derived connective-tissue progenitor cells per gram of tissue (p < 0.0001; 95% confidence interval [CI], 129,930 to 253,333), and those who developed heterotopic ossification had higher numbers of assayable osteogenic colonies (p < 0.016; 95% CI, 12,249 to 106,065). In the injured group, quantitative real-time reverse-transcription polymerase chain reaction performed on the in vitro expanded progeny of connective-tissue progenitors demonstrated upregulation of COL10A1, COL4A3, COMP, FGFR2, FLT1, IGF2, ITGAM, MMP9, PHEX, SCARB1, SOX9, and VEGFA in the patients with heterotopic ossification as compared with those without heterotopic ossification. CONCLUSIONS: Our study suggests that the number of connective-tissue progenitor cells is increased in traumatized tissue. Furthermore, wounds in which heterotopic ossification eventually forms have a higher percentage of connective-tissue progenitor cells committed to osteogenic differentiation than do wounds in which heterotopic ossification does not form. The early identification of heterotopic ossification-precursor cells and target genes in severe wounds not only may be an effective prognostic tool with which to assess whether heterotopic ossification will develop in a wound, but may also guide the future development of individualized prophylactic measures.

Outcomes associated with the internal fixation of long-bone fractures proximal to traumatic amputations.

BACKGROUND: Preservation of optimal residual limb length following a traumatic amputation can be challenging. The purpose of this study was to determine if acceptable results can be achieved by definitive fixation of a long-bone fracture proximal to a traumatic amputation. METHODS: We identified thirty-seven active-duty military service members who underwent internal fixation of a long-bone fracture proximal to a traumatic amputation. Functional status was assessed with the Tegner activity level scale and prosthesis use. Secondary outcome measures were the development of nonunion, infection, and heterotopic ossification. RESULTS: Twelve patients (32%) underwent amputation and fracture in the same osseous segment. Ten patients (27%) sustained bilateral traumatic amputations, and eight (22%) had a major fracture of the contralateral extremity. The median times to fracture fixation and amputation closure were twelve days and nineteen days, respectively, after the injury. The mean Tegner activity score was 3.32 (range, 1 to 6); patients with isolated extremity injuries had significantly higher Tegner scores than those with severe bilateral injuries (3.59 and 2.38, respectively; p = 0.04). Thirty-three patients (89%) developed an infection requiring surgical debridement. However, all fractures were treated until union occurred, and amputation level salvage was successful in all instances. Heterotopic ossification developed in twenty-eight patients (76%), with operative excision required in eleven patients (39%). CONCLUSIONS: High complication rates, but acceptable final results, can be achieved with internal fixation of a fracture proximal to a traumatic amputation to preserve functional joint levels or salvage residual limb length.

Arthroscopic versus open distal clavicle excision: comparative results at six months and one year from a randomized, prospective clinical trial.

The purpose of this report is to compare outcomes after arthroscopic versus open distal clavicle excision in the treatment of refractory acromioclavicular joint pain. A randomized, prospective clinical trial comparing the 6-month and 1-year outcomes of patients undergoing open distal clavicle excision (group 1) with those undergoing arthroscopic distal clavicle excision (group 2) was carried out. The Modified American Shoulder and Elbow Surgeons form, visual analog scale pain score, Short Form 36, and satisfaction questions were assessed preoperatively and at 6 months and 1 year postoperatively. Seventeen patients were enrolled. There was a trend across all measures for earlier or better outcomes (or both) after arthroscopic over open treatment. The improvement in visual analog scale pain score from preoperatively to 1 year postoperatively was significant for group 2 but not group 1 (P = .006 vs P = .13). Occult intra-articular pathology was detected and treated in 50% of group 2 patients. Arthroscopic and open distal clavicle excisions both provide significant pain reduction at 1 year. Both are effective surgeries for the treatment of refractory acromioclavicular joint pain. The ability to diagnosis and treat subtle concomitant shoulder pathology is a unique advantage of the arthroscopic approach.