The role of hematopoiesis in bone repair: an update.

PURPOSE OF REVIEW: The repair of bone after injury requires the participation of many different immune cell populations, which are derived from the hematopoietic lineage. The field of osteoimmunology, or the study of the interactions between bone and the immune system, is a growing field with emerging impact on both the basic science and clinical aspects of fracture healing. RECENT FINDINGS: Despite previous focus on the innate immune system in fracture healing, recent studies have revealed an important role for the adaptive immune system in bone repair. The composition of adaptive and innate immune cell populations present at the fracture site is significantly altered during aging and diet-induced obesity, which may contribute to delayed healing. Recent data also suggest a complicated relationship between fracture repair and systemic inflammation, raising the possibility that immune populations from distant sites such as the gut can impact the bone repair process. SUMMARY: These findings have important implications for the treatment of fracture patients with antibiotics or anti-inflammatory drugs. Furthermore, the effects of systemic inflammation on fracture repair in the contexts of aging or obesity should be carefully interpreted, as they may not be uniformly detrimental.

Identification and Management of Pelvic Fractures in Prehospital and Emergency Department Settings.

INTRODUCTION: This study aims to describe the characteristics of patients with a pelvic fracture treated at a level 1 trauma center, the proportion of prehospital undertriage and the use of pelvic circumferential compression device (PCCD). METHODS: This is a retrospective cohort study. Prehospital and inhospital medical records of adults (≥16 y old) with a pelvic fracture who were treated at Hopital de l'Enfant-Jesus-CHU de Québec (Quebec City, Canada), a university-affiliated level 1 trauma center, between September 01, 2017 and September 01, 2021 were reviewed. Isolated hip or pubic ramus fracture were excluded. Data are presented using proportions and means with standard deviations. RESULTS: A total of 228 patients were included (males: 62.3%; mean age: 54.6 [standard deviation 21.1]). Motor vehicle collision (47.4%) was the main mechanism of injury followed by high-level fall (21.5%). Approximately a third (34.2%) needed at least one blood transfusion. Compared to those admitted directly, transferred patients were more likely to be male (73.0% versus 51.3%, P < 0.001) and to have a surgical procedure performed at the trauma center (71.3% versus 46.9%, P < 0.001). The proportion of prehospital undertriage was 22.6%. Overall, 17.1% had an open-book fracture and would have potentially benefited from a prehospital PCCD. Forty-six transferred patients had a PCCD applied at the referral hospital of which 26.1% needed adjustment. CONCLUSIONS: Pelvic fractures are challenging to identify in the prehospital environment and are associated with a high undertriage of 22.6%. Reducing undertriage and optimizing the use of PCCD are key opportunities to improve care of patients with a pelvic fracture.

Hypotension in the Emergency Department and Contrast Extravasation on Computerized Tomography Predict Blood Transfusion in Low-Energy Pelvic Fractures.

INTRODUCTION: Although low-energy pelvic fractures seldom present with significant hemorrhage, early recognition of at-risk patients is essential. We aimed to identify predictors of transfusion requirements in this cohort. METHODS: A 7-y retrospective chart review was performed. Low-energy mechanism was defined as falls of ≤5 feet. Fracture pattern was classified using the Orthopedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen system as A, B, or C. Primary outcome was transfusion of ≥2 units of packed red blood cells in the first 48 h. Univariable analysis and logistic regression analysis were performed. A P value ≤0.05 was considered significant. RESULTS: Five hundred forty six patients were included with median (interquartile range) age of 86 (79-91) and median (interquartile range) Injury Severity Score of 5 (4-8). Five hundred forty one (99%) had type A fractures. Twenty six (5%) had the primary outcome and 17 (3%) died. Logistic regression found that systolic blood pressure <100 mmHg at any time in the Emergency Department, Injury Severity Score, and pelvic angiography were predictors of the primary outcome. Seventeen percent of those who had the primary outcome died compared with 2% who did not (P = 0.0004). Three hundred sixty four (67%) received intravenous contrast for computerized tomography scans and of these, 44 (12%) had contrast extravasation (CE). CE was associated with the primary outcome but not mortality. CONCLUSIONS: Hypotension at any time in the Emergency Department and CE on computerized tomography predicted transfusion of ≥2 units packed red blood cells in the first 48 h in patients with low-energy pelvic fractures.

Traumatic injuries of the immature hip and pelvis.

PURPOSE OF REVIEW: The pelvis and hip account for 0.3--4% of fractures of the immature skeleton, and generally result from high energy trauma. These fractures range in severity from apophyseal avulsions to complete disruptions of the pelvic ring. The purpose of this article is to review the presentation, diagnosis, treatment and complications of these injuries in order to inform clinicians involved in their management. There is a lack of evidence-based management protocols for fractures of the immature pelvis largely due to their rarity and lack of robust scientific literature on the topic. RECENT FINDINGS: Computed tomography/MRI is essential as up to 30% of pelvis and 70% of acetabular fractures are not identified on initial radiographs. A sub-optimal outcome is common in unstable fractures treated conservatively and adequate reduction and surgical stabilization is often required to avoid long-term morbidity. SUMMARY: A coordinated approach involves resuscitation and temporary stabilization with planned definitive fixation. It is generally accepted that these injures should be managed in paediatric trauma centres. Whilst injuries vary in pattern and severity, we present an overview that considers the evaluation and treatment of the paediatric patient with pelvic and hip fractures to ensure that these injuries are identified promptly and treated by surgeons familiar with contemporary management algorithms.

Sternal fixation for traumatic sternal fractures demonstrates better long-term quality of life outcomes than nonoperative management: A survey analysis.

INTRODUCTION: Sternal fractures are rare, causing significant pain, respiratory compromise, and decreased upper extremity range of motion. Sternal fixation (SF) is a viable treatment option; however, there remains a paucity of literature demonstrating long-term benefits. This study examined long-term outcomes of SF, hypothesizing they have better long-term quality of life (QoL) than patients managed nonoperatively (NOM). METHODS: This was a survey study at our level 1 academic hospital. All patients diagnosed with a sternal fracture were included from January 2016 to July 2021. Patients were grouped whether they received SF or NOM. Basic demographics were obtained. Three survey phone call attempts were conducted. The time from injury to survey was recorded. Outcomes included responses to the QoL survey, which included mobility, self-care, usual activities, chest pain/discomfort, and anxiety/depression. The survey scale is 1-5 (1 = worst condition possible; 5 = best possible condition). Patients were asked to rate their current health on a scale of 0-100 (100 being the best possible health imaginable). Chi square and t-tests were used. Significance was set at p < 0.05. RESULTS: Three hundred eighty four patients were surveyed. Sixty nine underwent SF and 315 were NOM. Thirty-eight (55.1%) SF patients and 126 (40%) NOM patients participated in the survey. Basic demographics were similar. Average days from sternal fracture to survey was 1198 (±492) for the SF group and 1454 (±567) for the NOM group. The SF cohort demonstrated statistically significant better QoL than the NOM cohort for all categories except anxiety/depression. CONCLUSION: SF provides better long-term QoL and better overall health scores compared to NOM.

WNT-modulating gene silencers as a gene therapy for osteoporosis, bone fracture, and critical-sized bone defects.

Treating osteoporosis and associated bone fractures remains challenging for drug development in part due to potential off-target side effects and the requirement for long-term treatment. Here, we identify recombinant adeno-associated virus (rAAV)-mediated gene therapy as a complementary approach to existing osteoporosis therapies, offering long-lasting targeting of multiple targets and/or previously undruggable intracellular non-enzymatic targets. Treatment with a bone-targeted rAAV carrying artificial microRNAs (miRNAs) silenced the expression of WNT antagonists, schnurri-3 (SHN3), and sclerostin (SOST), and enhanced WNT/ß-catenin signaling, osteoblast function, and bone formation. A single systemic administration of rAAVs effectively reversed bone loss in both postmenopausal and senile osteoporosis. Moreover, the healing of bone fracture and critical-sized bone defects was also markedly improved by systemic injection or transplantation of AAV-bound allograft bone to the osteotomy sites. Collectively, our data demonstrate the clinical potential of bone-specific gene silencers to treat skeletal disorders of low bone mass and impaired fracture repair.

A Retrospective Study of the Presentation, Diagnosis, Management, and Outcomes of 27 Patients with Osteogenesis Imperfecta at a Single Center in Türkiye.

BACKGROUND This retrospective study aimed to evaluate the presentation, diagnosis, management, and outcomes of 27 patients diagnosed with osteogenesis imperfecta at a single center in Türkiye between January 2011 and January 2020. MATERIAL AND METHODS We analyzed data from the medical records of 27 patients with osteogenesis imperfecta admitted to Çukurova University Faculty of Medicine, Department of Orthopedics and Traumatology, between January 2011 and January 2020. The data included the clinical examination notes of the cases classified according to the Sillence and Shapiro systems, age, sex, parental consanguinity, genetic analysis (DNA isolation) results, the number and localization of past fractures, treatment methods, complications, hypermobility, and ambulation scoring. RESULTS The mean age of the patients (n=13 male, n=14 female) was 10.4±7.4 years, ranging from 3 to 39 years. Almost half (n=15, 55.6%) had consanguineous parents. The patients had 131 fractures during the 9 years between January 2011 and January 2020, with the femur being the most commonly fractured bone; 13 patients (48.15%) received surgical and conservative treatments, while the remaining 14 underwent only conservative treatments. The results revealed a strong association between the number of fractures and the types of genetic mutations (P=0.004). CONCLUSIONS Study findings indicate that the type of genetic mutation was not significantly correlated with the risk of treatment complications in osteogenesis imperfecta cases. Nevertheless, the study reveals a noteworthy association between the type of mutation and the number of surgeries required. Specifically, patients with the COL1A1 mutation needed more surgeries.

Neonatal upper limb fractures - a narrative overview of the literature.

The aim of this paper is to review the topic of neonatal fractures of the upper limb, describing the different types of fractures focusing on the etiology, epidemiology, risk factors, clinical approach, diagnosis, treatment and prognosis of these injuries. We included all types of research studies, both experimental and observational, published in English, French, Portuguese and Spanish. The information was obtained using the keywords neonatal upper limb fracture, clavicle fracture or humerus fracture from the following resources: MEDLINE database, Embase® database and LILACS database. Other resources such as hand searches of the references of retrieved literature and authoritative texts, personal and hospital libraries searching for texts on upper limb neonatal fractures, discussions with experts in the field of upper limb neonatal fractures and personal experience, were also considered for the completion of the article.Neonatal fractures of the upper limb are consensually considered to have a good prognosis and no long-term sequelae. Conservative treatment is the option in the vast majority of the fractures and is associated with excellent results, with good healing, full range of motion, adequate remodeling without obvious deformity, neurologic impairment or functional implications.

A self-powered implantable and bioresorbable electrostimulation device for biofeedback bone fracture healing.

Electrostimulation has been recognized as a promising nonpharmacological treatment in orthopedics to promote bone fracture healing. However, clinical applications have been largely limited by the complexity of equipment operation and stimulation implementation. Here, we present a self-powered implantable and bioresorbable bone fracture electrostimulation device, which consists of a triboelectric nanogenerator for electricity generation and a pair of dressing electrodes for applying electrostimulations directly toward the fracture. The device can be attached to irregular tissue surfaces and provide biphasic electric pulses in response to nearby body movements. We demonstrated the operation of this device on rats and achieved effective bone fracture healing in as short as 6 wk versus the controls for more than 10 wk to reach the same healing result. The optimized electrical field could activate relevant growth factors to regulate bone microenvironment for promoting bone formation and bone remodeling to accelerate bone regeneration and maturation, with statistically significant 27% and 83% improvement over the control groups in mineral density and flexural strength, respectively. This work provided an effective implantable fracture therapy device that is self-responsive, battery free, and requires no surgical removal after fulfilling the biomedical intervention.

Common Foot Fractures.

Foot fractures account for about one-third of lower extremity fractures in adults. They are typically caused by a crush injury or an axial or twisting force on the foot. Patients usually present with bony point tenderness and swelling of the affected area. Weight-bearing varies based on the extent of the fracture and the patient's pain tolerance. When a foot or toe fracture is suspected, anteroposterior, lateral, and oblique radiography with weight-bearing should be obtained. The Ottawa foot and ankle rules can help determine the need for radiography after an acute ankle inversion injury. Many foot fractures can be managed with a short leg cast or boot or a hard-soled shoe. Weight-bearing and duration of immobilization are based on the stability of the fracture and the patient's pain level. Most toe fractures can be managed nonsurgically with a hard-soled shoe for two to six weeks. Close attention should be paid to the great toe because of its role in weight-bearing, and physicians should follow specific guidelines for orthopedic referral. Meta-tarsal shaft fractures are managed with a boot or hard-soled shoe for three to six weeks. The proximal aspect of the fifth metatarsal has varied rates of healing due to poor blood supply, and management is based on the fracture zone. Lis-franc fractures are often overlooked; radiography with weight-bearing should be obtained, and physicians should look for widening of the tarsometatarsal joint. Other tarsal bone fractures can be managed with a short leg cast or boot for four to six weeks when nonsurgical treatment is indicated. Common foot fracture complications include arthritis, infection, malunion or nonunion, and compartment syndrome.

Clinically Significant Treatment Delay in Pediatric Scaphoid Fractures.

PURPOSE: Pediatric scaphoid fractures present to treatment in a delayed manner 8% to 29% of the time. The indications for cast immobilization in this population are not clear. The definition of a clinically important treatment delay is based only on anecdotal reports. Successful treatment with a cast may be more desirable than surgical intervention. However, it remains unclear what clinical and radiographic factors may predict success with casting. METHODS: A retrospective analysis of all scaphoid fractures treated at a single pediatric hospital was performed to identify fracture characteristics, the presence of cystic change, treatment method, and healing rate. A cut-point analysis was performed to determine the number of days of treatment delay, predictive of casting failure. Kaplan-Meier assessments were performed to determine the differences in time in cast. Characteristics of the delayed group were described and stratified by treatment success or failure. RESULTS: After review, 254 patients met the inclusion criteria. Cut-point analysis determined that a presentation delay of ≥21 days was associated with failure to unite with casting. The median time in the cast for the acute and delayed groups was not significantly different. The casting union rate of delayed fractures was less than acute fractures (75.0% vs 97.0%). CONCLUSIONS: Delayed presentation of scaphoid fractures 21 days or more after injury predicts a greater risk of casting failure; however, the union rate remains high with comparable time in cast. Cast immobilization for scaphoid fractures presenting 21 days or more after injury is a reasonable option. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognosis IV.

The Pressure Is on: Dorsal Versus Volar Univalves for Long-arm Casts.

BACKGROUND: Fiberglass casts are routinely used to treat fractures of the upper extremity. When posttraumatic edema is anticipated, the cast is often valved to hopefully prevent potential complications, especially compartment syndrome. Due to volar forearm compartments being most involved with upper extremity compartment syndrome, volar skin surface pressures (SSP) are paramount. Despite past literature showing that a univalved cast will retain a 3-point mold better than a bivalved cast, there is a paucity of information analyzing the effects of univalving on the volar SSP. We hypothesized that a volar univalve technique would have a greater decrease in the volar skin surface pressures compared to a dorsal univalve in long-arm casts. METHODS: A 100-mL saline bag attached to an arterial line pressure transducer was placed between a long-arm cast and the skin along the volar forearm of a single adult volunteer. Fourteen casts were applied by a single certified orthopaedic technologist with 30 years of experience and assigned randomly to receive either a volar or dorsal univalve. We calculated the change in volar forearm SSP on each cast in 4 stages: isolated univalve, with a 3-mm cast spacer, with a 6-mm spacer, and with bivalve. Statistical analysis of the data was performed using a Mann-Whitney U test. RESULTS: When comparing volar versus dorsal univalve, volar SSP significantly dropped by a mean of 32.00 versus 20.43 mm Hg ( P value=0.001) in stage I, 45.14 versus 38.00 mm Hg in stage II ( P value=0.026), and 56.53 versus 49 mm Hg in stage III ( P value=0.001). There was no significant difference between the 2 groups after a bivalve was performed at stage IV ( P value=0.318). CONCLUSION: Our findings support that a volar univalve with a 6-mm spacer will provide the greatest reduction of skin surface pressure while theoretically maintaining the cast's structural integrity and biomechanical properties when compared to a bivalved cast. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Advances in Hand Therapy: Best Practice in Conservative Management of Proximal Phalangeal Fractures in Children.

BACKGROUND: Proximal phalangeal fractures are one of the most commonly treated hand injuries in children. Conservative management of these fractures is often to splint for 5 weeks post injury, despite children presenting as clinically healed at 3 weeks post injury. Therefore, we investigated the effect of splinting for only 3 weeks in children who present with clinically healed proximal phalangeal fractures at 3 weeks compared with usual care. METHODS: Participants (n=80, aged 10.3 ±2.5 years) presenting to the Hand Clinic of a tertiary Children's Hospital in Sydney, Australia, were randomly allocated into a Current Protocol and a New Protocol group. Following were the inclusion criteria: aged between 5 and 16 years; present with an non-displaced or minimally displaced and stable fracture; no surgical intervention; assessed as clinically healed at 3-week visit. The primary outcome measure was total active motion (TAM) of the injured digit compared with the contralateral digit (deg), at 5 weeks post injury. Secondary outcome measures were grip strength, and a parent-reported questionnaire. Statistical analysis used χ 2 test and the absolute difference described by a 90% CI. The New Protocol was considered noninferior if the 90% CI overlap was > 20% of the Current Protocol. Analysis was by intention to treat. RESULTS: There was a 10% loss to follow up at 5 weeks (Current Protocol =4, New Protocol =4). All CIs between groups overlapped by >10%. TAM 90% CI for Current Protocol was 17.7 to 5.4 degrees and for the New Protocol was 4.7 to 1.6 degrees. CONCLUSIONS: A change in practice is warranted to cease immobilization for children with conservatively managed proximal phalangeal fractures who present as clinically healed at 3 weeks. Therapist assessment of fracture healing is an appropriate indicator for intervention and can be utilized in a therapist-led model of care. LEVEL OF EVIDENCE: Level 1-noninferiority randomized control trial with 2 parallel arms.

Splinting of Low-Risk Pediatric Fractures.

ABSTRACT: This review covers common orthopedic injuries seen after acute traumatic injury. A thorough physical examination and radiographic review of these injuries are key to ensuring appropriate management. Although many injuries may require urgent or emergent orthopedic consultation and management, this review focuses on injuries that are low-risk and amenable to splinting with outpatient orthopedic follow-up. This review covers key physical examination features, radiographic findings that help providers assess injuries, as well as reviewing splinting application to help facilitate rapid management of these injuries in the acute care setting.

Resuscitative Endovascular Balloon Occlusion of The Aorta (REBOA) And Mortality in Hemorrhagic Shock Associated with Severe Pelvic Fracture: a National Data Analysis.

BACKGROUND: The purpose of the study was to evaluate the mortality of patients who received Resuscitative Endovascular Balloon Occlusion of The Aorta (REBOA) in severe pelvic fracture with hemorrhagic shock. METHODS: The American College of Surgeon Trauma Quality Improvement Program (ACS-TQIP) database for the calendar years 2017-2019 was accessed for the study. The study included all patients aged 15 years and older who sustained severe pelvic fractures, defined as an injury with an abbreviated injury scale (AIS) score of ≥ 3, and who presented with the lowest systolic blood pressure (SBP) of < 90 mmHg. Patients with severe brain injury were excluded from the study. Propensity score matching was used to compare the patients who received REBOA with similar characteristics to patients who did not receive REBOA. RESULTS: Out of 3,186 patients who qualified for the study, 35(1.1%) patients received REBOA for an ongoing hemorrhagic shock with severe pelvic fracture. The propensity matching created 35 pairs of patients. The pair-matched analysis showed no significant differences between the group who received REBOA and the group that did not receive REBOA regarding patients' demography, injury severity, severity of pelvic fractures, lowest blood pressure at initial assessment and laparotomies. There was no significant difference found between REBOA versus no REBOA group in overall in-hospital mortality (34.3% vs. 28.6, P = 0.789). CONCLUSION: Our study did not identify any mortality advantage in patients who received REBOA in hemorrhagic shock associated with severe pelvic fracture compared to a similar cohort of patients who did not receive REBOA. A larger sample size prospective study is needed to validate our results. CASE-CONTROL RETROSPECTIVE STUDY: Level of Evidence IV.

The epidemiology of pelvic ring fractures in Qatar.

PURPOSE: This study aimed to determine the incidence of pelvic ring fractures and their associated epidemiological profile in Qatar. METHODS: A retrospective cross-sectional study was performed at the only level I trauma centre in Qatar for patients diagnosed with pelvic ring fractures between January 2016 and December 2018. Age, sex, mechanism of injury, fracture classification and associated characteristics, mode of treatment, associated nerve injuries, and other complications were analyzed. RESULTS: A total of 327 consecutive patients were included, with an average age of 32.6 years. Most of the included patients were males, 85% (279), with a male: female ratio of 6:1. The incidence of pelvic fractures was 3.887/100,000 across the three years. High-speed motor vehicle collisions (MVC) were the most common mechanism of injury (108, 33%), followed by falling from height (105, 32%). Young-Burgess lateral compression (LC) fracture type was the most frequent (224, 68.5%) and was associated with 25% of the entire mortalities. Nine (2.8%) cases were open fractures, and 12% (39) were deemed unstable. Around 29% of cases had associated injuries, with an overall mortality rate of 4.9% (16) observed. Most fractures were treated nonoperatively(n = 283,86.5%). CONCLUSION: This study demonstrated the epidemiology of pelvic fractures in Qatar. MVC and work-related injuries were predominant in a younger cohort compared to the literature. Also, the mortality rate was lower than those reported in the literature. Therefore, well-trained surgeons and specialized trauma centres for treating these injuries are recommended.

Comprehensive comparison between conservative therapy and surgical management for completely displaced and comminuted mid-shaft clavicle fractures.

PURPOSE: It is still controversial whether complete displaced mid-shaft clavicle fractures should be treated with internal fixation or conservative therapy. This retrospective study aims to compare clinical outcomes of two treatment protocols. MATERIALS AND METHODS: 105 patients with displaced and comminuted mid-shaft clavicle fractures were included in this study, among which 55 patients were treated conservatively and 50 patients accepted surgical fixation and were followed up for over 20 months on average. Rate of union, malunion, time taken for union, functional outcome, self-reported satisfaction and complications were compared. RESULTS: Union rate of operative group (n=49, 98.0%) was higher than the non-operative group (n=48, 87.3%). Time taken for union in operative group (2.37±1.06 months) was shorter than the non-operative group (3.69±1.01 months). Malunion and asymmetric were only seen in the conservative group. Numbness of the shoulder was only reported in the operative group (n=23, 46.0%). Most of patients in the operative group (n=45, 90%) accepted a second operation to remove the implant. No statistically difference was found in self-reported satisfaction, Quick-DASH and Constant-Murley score. The operative group returned to work faster (1.47±0.89 to 3.34±1.37 months), regained full range of motion earlier (1.66±0.78 to 3.83±1.24 months) and regained strength faster (3.86±2.45 to 8.03±2.78 months) than the non-operative group. CONCLUSION: Complete displaced and comminuted mid-shaft clavicle fractures treated surgically have more reliable union and faster recovery when compared to conservatively treated fractures.

Ex vivo biomechanical evaluation of an adhered fiberglass and polymethyl methacrylate sole-hoof wall cast on stabilization of type III distal phalanx fractures under simulated physiologic midstance loads.

OBJECTIVE: To evaluate the effect of the application of a novel fiberglass-glue cast (FGC) on the fracture gap width in experimentally created type III distal phalanx fractures in cadaveric specimens under simulated physiologic loads. STUDY DESIGN: Ex vivo biomechanical laboratory study. ANIMALS: Nine unilateral adult equine cadaver forelimbs. METHODS: Type III distal phalanx fractures were created in forelimb specimens, which maintained distal components of the passive stay apparatus. The fracture gap was measured at 5%, 20%, 25%, 50%, 75%, and 95% of fracture length (palmar articular border to solar margin) using D65Pr-PaDiO radiographs. The limb was axially loaded (700, 3600, 4600, and 6700 N) before, during, and after removal of a woven fiberglass cloth and polymethyl methacrylate cast that encompassed the sole and distal portion of the hoof wall (FGC). Fracture gap widths were compared among loads and treatments using a mixed model ANOVA. RESULTS: On average, under simulated physiological midstance loads, the fracture gap width was 0.2 mm smaller after FGC application, with the greatest decrease (0.5 mm) near the articular surface. On average, it was 0.3 mm smaller than after FGC removal. Fracture gap width was 0.1 mm greater when midstance loads transitioned from standing load to walking, trotting, and gallop loads. The fracture gap width increased by 1.3 mm with increasing distance from the articular surface. CONCLUSION: The FGC reduced the fracture gap width and prevented the fracture gap widening that occurred after FGC removal. CLINICAL SIGNIFICANCE: The findings support consideration of FGC use in the treatment of horses with type III distal phalangeal fractures.

Do multiple fractures affect risk of fixation failure after surgical treatment of midshaft clavicle fracture? A retrospective cohort study.

BACKGROUND: Surgical treatment of midshaft clavicle fractures is associated with quick recovery and low risk of non-union. However, fixation failure may occur in case of severe comminution fractures. Moreover, clinical outcomes may be affected when clavicle fractures occur in combination with other injuries, particularly those involving the lower extremities, as the use of crutches or walkers may hinder the process of rehabilitation by adding strain on the acromioclavicular (AC) joint, resulting in possible fixation failure. This study aims to identify risk factors for fixation failure of midshaft clavicle fractures and elucidate the role of combined fractures in treatment outcomes. METHODS: This study included patients diagnosed with midshaft clavicle fractures who underwent initial surgery between January 2012 and November 2021 at a designated regional trauma center hospital. Retrospective evaluation of fixation failure was carried out in 352 patients with midshaft clavicle fractures using standard clinical evaluation protocols and conventional radiographs. The prevalence of fixation failure and the effects of several demographic variables on the risk of fixation failure and non-union were examined. Multivariate logistic regression analysis was carried out to identify independent risk factors for fixation failure. RESULTS: Fixation failure occurred in 40 patients (11.4%). Multivariate analysis identified comminution [odds ratio (OR) 3.532, p value = 0.003, 95% confidence interval (CI) 1.55-8.05)] and fewer number of screws (OR 0.223, p value = 0.022, 95% CI 0.06-0.80) as risk factors for fixation failure. Surgical techniques using wire cerclage reduced the chances of fixation failure in comminuted fractures (OR 0.63, p value = 0.033, 95% CI 0.05-0.80). Combined fractures that required rehabilitation using walkers or crutches increased the risk of non-union (OR 19.043, p value = 0.032, 95% CI 1.28-282.46). CONCLUSIONS: Additional fixation of comminuted fractures using cerclage can reduce the risk of treatment failure, while multiple fractures or rehabilitation for ambulation increases the risk of the same. LEVEL OF EVIDENCE: III.

New Classification for Pediatric Proximal Fifth Metatarsal Fractures.

Proximal fifth metatarsal fractures are the most common foot fractures in children. Attempts to classify these injuries are misapplied and inadequately predict outcomes. This is the first study to identify factors associated with healing in pediatric fifth metatarsal fractures. In this retrospective cohort study (N = 305), proximal fifth metatarsal fractures were classified on radiographs by location on the bone, alignment (transverse or oblique), displacement (>2 mm), and completion through the bone. Based on the literature, they were secondarily sorted by category: apophyseal, intra-articular metaphyseal, extra-articular metaphyseal, and diaphyseal. Primary outcomes included times to healing, indicated by clinical symptoms, immobilization, and return to sports, as well as radiographic callus formation, bridging, and remodeling. Healing times were compared by ANOVA and linear regression. Location had a significant effect on times of immobilization and return to sports, but alignment, displacement, and completion were not associated with healing. When re-classified, the categories were also associated with immobilization and return to sports. Apophyseal fractures healed fastest and diaphyseal fractures required the most time to heal. There was no difference between extra- and intra-articular fractures. For every year of age, symptoms resolved about 2 days sooner. Neither gender nor body mass index (BMI) was positively or negatively associated with healing times. In conclusion, classifying fractures by apophyseal, metaphyseal, and diaphyseal is the most concise, accurate, and useful system. This is the largest series of nonoperatively treated proximal fifth metatarsal fractures in children and a robust standard to which surgical management can be compared.