A 3D geometric morphometric analysis of the bovid distal humerus, with special reference to Rusingoryx atopocranion (Pleistocene, Eastern Africa).

The family Bovidae [Mammalia: Artiodactyla] is speciose and has extant representatives on every continent, forming key components of mammal communities. For these reasons, bovids are ideal candidates for studies of ecomorphology. In particular, the morphology of the bovid humerus has been identified as highly related to functional variables such as body mass and habitat. This study investigates the functional morphology of the bovid distal humerus in isolation due to its increased likelihood of preservation in the fossil record, and the resulting opportunity for a better understanding of the ecomorphology of extinct bovids. A landmark scheme of 30 landmarks was used to capture the 3D distal humerus morphology in 111 extant bovid specimens. We find that the distal humerus has identifiable morphologies associated with body mass, habitat preference and tribe affiliation and that some characteristics are shared between high body mass bovids and those living on hard, flat terrain which is likely due to the high stress on the bone in both cases. We directly apply our findings regarding extant bovids to the extinct alcelaphine bovid, Rusingoryx atopocranion from the mid to late Pleistocene (>33-45 ka) Lake Victoria region of Kenya. This species is known for some peculiar morphologies including a domed cranium with hollow nasal crests, and having small hooves for a bovid of its size. Another interesting aspect of Rusingoryx's skeletal morphology which has not been addressed is an unusual protrusion on the lateral epicondyle of the distal humerus. Despite considerable individual variation in the Rusingoryx specimens, we find evidence to support its historical assignment to the tribe Alcelaphini, and that it likely preferred open grassland habitats, which is consistent with independent reconstructions of the palaeoenvironment. We also provide the most accurate body mass estimate for Rusingoryx to date, based on distal humerus centroid size. Overall, we are able to conclude that the distal humerus in extant bovids is highly informative regarding body mass, habitat preference and tribe, and that this can be applied directly to a fossil taxon with promising results.

Incidence of four major osteoporotic fragility fractures among older individuals in Sado, Japan, in 2020.

INTRODUCTION: This study compared the 2020 incidence of fragility fractures in Sado City with those from 2004 to 2015. MATERIALS AND METHODS: Data from patients aged ≥ 60 years living in Sado City with fragility fractures in the hip, vertebral, distal radius, and proximal humerus between January 1 and December 31, 2020, were collected. We examined the number and incidence of four types of osteoporotic fractures in the older population aged ≥ 60 years living in Sado City in 2020. We compared the results with those of the 2004, 2010, and 2015 surveys, examining the temporal change and trend in the incidence of the four fracture types in this population. We investigated the use rate of anti-osteoporotic medications and the relationship between their administration and the occurrence of fragility fractures. RESULTS: The age-specific incidence of hip fractures slightly decreased from 2015. However, the incidence of the other three fractures slightly increased, although the difference was not statistically significant. The incidence of hip fractures markedly increased in the 80 s. In 2020, the percentage of patients taking anti-osteoporotic agents before the occurrence of fractures decreased to 12.4% from 14.5% in 2015; it increased from 4% in 2004 to 7.6% in 2010. CONCLUSION: The 2020 incidence of the four fractures did not decrease, and the percentage of patients receiving anti-osteoporotic agents did not increase. A higher frequency of osteoporosis treatment is necessary to reduce the incidence of fragility fractures. We recommend using anti-osteoporotic agents to prevent hip fractures among individuals in their mid-70 s and above.

Durability of intercalary endoprosthesis for humeral reconstruction.

INTRODUCTION: The humerus is a common site of metastases and primary tumors. For some patients with a segmental defect and/or diaphyseal cortical destruction a cemented intercalary device may provide a more reliable construct, however data on their use is limited. METHODS: We reviewed 43 (28 male and 15 female) patients treated with an intercalary humeral spacer at a single tertiary referral center between 1989 and 2022. Humeral lesions were most commonly secondary to metastatic disease (n = 29, 68%), with 25 (58%) patients presenting with a pathologic fracture. Mean age and body mass index were 66 years and 27.9 kg/m2 . First generation taper joint device were used in 22 patients and second-generation lap device in 21 patients. RESULTS: Following reconstruction the 2-year overall survival was 30%. Mechanical complications occurred in 11 patients, most commonly aseptic loosening (n = 6, 14%). With death as a competing risk, the cumulative incidence of mechanical failure was 28% at 2-years postoperative. Following the procedure, mean Musculoskeletal Tumor Society scores was 70% and mean shoulder elevation was 87°. CONCLUSION: Reconstruction of the humeral diaphysis with an intercalary endoprosthesis provides restoration of function of the upper extremity, however, is associated with one in four patients having mechanical failure.

Ballistic long bone fracture pattern: an experimental study.

When dealing with badly preserved cadavers or skeletal human remains, the assessment of death circumstances remains challenging. When forensic evidence cannot be taken from the skin and soft tissue, the information may only be deduced from more resistant elements such as bone. Compared to cranial gunshot injuries, reliable data on ballistic long bone trauma remains scarce. This study aims to define ballistic fracture characteristics in human long bones. The shaft of 16 femurs and 13 humeri from body donors was perpendicularly shot with a 9-mm Luger full metal jacket bullet at an impact velocity of 360 m/s from a distance of 2 m. Some bones were embedded in Clear Ballistics Gel®, and some were shot without soft tissue simulant in order to better visualise the fracture propagation on the high-speed camera. The fractures were examined macroscopically and compared between the sample groups. We consistently found comminuted fractures with a stellate pattern. Fracture details were classified into entrance, exit and general characteristics. For some traits, we detected different occurrence values in the group comparison. The results indicate that some of the traits depend on bone properties such as shaft diameter, bone length and cortical thickness. The presence of ballistic gel also influenced some fracture traits, emphasising the relevance of soft tissue simulant in osseous gunshot experiments. This study revealed new insights in the detailed fracture pattern of human long bones. These may serve as guidelines for the identification and reconstruction of gunshot trauma in human long bones.

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.

Peripheral nerve injuries associated with dislocated supracondylar fractures of distal humerus in children: incidence and need of surgical treatment.

PURPOSE: The objective of this study was to determine the incidence, necessity for neurosurgical intervention, and overall results of the treatment of pediatric peripheral nerve injuries associated with dislocated supracondylar fractures of the distal humerus. METHOD: A retrospective analysis of pediatric patients with supracondylar fractures treated from April 2019 to April 2022 with a minimum follow-up of 3 months was conducted. RESULTS: Of 453 included patients, there were 51 recorded peripheral nerve injuries. The ulnar nerve was the most frequently injured nerve. Nine patients required neurosurgical intervention, with the most common procedure being the release of entrapped nerves. The combination of a supracondylar fracture and arterial injury was identified as a significant risk factor for peripheral nerve injury (p < 0.001). Only one patient experienced an unsatisfactory outcome. CONCLUSION: Although the prognosis for peripheral nerve injuries in children with supracondylar fractures is generally favorable, these injuries must be properly identified. We recommend an active neurosurgical approach in children with persisting neurological deficits to minimize the risk of permanent neurological impairment.

Health-economic evaluation of orthogeriatric co-management for patients with forearm or humerus fractures: an analysis of insurance claims data from Germany.

Orthogeriatric co-management (OGCM) describes a collaboration of orthopedic surgeons and geriatricians for the treatment of fragility fractures in geriatric patients. While its cost-effectiveness for hip fractures has been widely investigated, research focusing on fractures of the upper extremities is lacking. Thus, we conducted a health economic evaluation of treatment in OGCM hospitals for forearm and humerus fractures.In a retrospective cohort study with nationwide health insurance claims data, we selected the first inpatient stay due to a forearm or humerus fracture in 2014-2018 either treated in hospitals that were able to offer OGCM (OGCM group) or not (non-OGCM group) and applied a 1-year follow-up. We included 31,557 cases with forearm (63.1% OGCM group) and 39,093 cases with humerus fractures (63.9% OGCM group) and balanced relevant covariates using entropy balancing. We investigated costs in different health sectors, length of stay, and cost-effectiveness regarding total cost per life year or fracture-free life year gained.In both fracture cohorts, initial hospital stay, inpatient stay, and total costs were higher in OGCM than in non-OGCM hospitals. For neither cohort nor effectiveness outcome, the probability that treatment in OGCM hospitals was cost-effective exceeded 95% for a willingness-to-pay of up to €150,000.We did not find distinct benefits of treatment in OGCM hospitals. Assigning cases to study groups on hospital-level and using life years and fracture-free life years, which might not adequately reflect the manifold ways these fractures affect the patients' health, as effectiveness outcomes, might have underestimated the effectiveness of treatment in OGCM hospitals.

Cement-augmented locked plate fixation proximal humerus fractures in elderly patient: a systematic review and meta-analysis.

BACKGROUND: This systemic review and meta-analysis aimed to evaluate the clinical outcomes of proximal humeral fracture in elderly patient fixation using locked plate with or without cement augmentation. METHODS: The databases of PubMed, Embase, and Cochrane Library were searched in August 2023 for literature comparing the clinical outcomes of patients with PHFs treated with locked plate alone and locked plate augmented with cement. Data describing study design; level of evidence; inclusion criteria; demographic information; final follow-up; revision rate; implant failure rate; avascular necrosis rate; total complication rate; constant score; and disability of arm, shoulder, and hand (DASH) score were collected. RESULTS: Eight studies (one randomized-controlled trial and seven observational studies), involving 664 patients, were identified. Compared with locked plates alone, using cement-augmented locked plates reduced the implant failure rate (odds ratio (OR) = 0.19; 95% confidence interval (CI) 0.10-0.39; P < 0.0001) and total complication rate (OR = 0.45; 95% CI 0.29-0.69; P = 0.0002) and improved DASH scores (mean difference (MD) = 2.99; 95% CI 1.00-4.98; P = 0.003). However, there was no significant difference in clinical outcomes, including revision rate, avascular necrosis rate, and constant score. CONCLUSION: In this review and meta-analysis, fixation of the PHFs in elderly patients using locked plates with or without cement augmentation has no significant difference in revision rate, but the implant failure and total complication rates may be lesser on using the cement-augmented locked plate for fixation than on using a locked plate alone. Good results are expected for most patients treated with this technique. TRIAL REGISTRATION: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)21 guidelines were followed to conduct this systematic review and meta-analysis and was registered as a protocol in PROSPERO (CRD42022318798).

Application of Kirschner wire placement guided technology in paediatric supracondylar humerus fractures.

BACKGROUND: To analyze the clinical efficacy of K-wire placement guided technology in paediatric supracondylar humerus fractures. METHODS: A retrospective study was conducted in 105 patients who underwent closed reduction and percutaneous pinning surgeries in our hospital from June 2019 to August 2022. 54 patients treated with a assisted reduction fixation device to assist in closed reduction and percutaneous K-wire cross-fixation were allocated into the Non-guided group, and 51 patients with K-wire placement guided technology to guide K-wire placement were assigned into the Guided group. The operation duration, number of disposable K-wire placement, intraoperative fluoroscopy frequency, Baumann angle, carrying angle, fracture healing time and Flynn score of elbow joint function at the final follow-up were compared between two groups. The postoperative complications of two groups were recorded. RESULTS: There were significant differences between two groups in terms of operation duration, intraoperative fluoroscopy frequency, and disposable K-wire placement rate (p < 0. 05), while no significant differences of Baumann angle, carrying angle and the fracture healing time between two groups were observed (p > 0. 05). In the control group, ulnar nerve injury in 2 case, pin site infection in 4 cases, mild cubitus varus in 2 cases and loss of reduction in 4 cases were detected. In the study group, ulnar nerve injury in 1 case, pin site infection in 2 cases and loss of reduction in 1 case was observed. There was no significant difference in Flynn scores between two groups. CONCLUSION: K-wire placement guided technology is simple and convenient. The application of K-wire placement guided technology could relatively improved disposable K-wire placement rate, shorten the intraoperative fluoroscopy frequencies and reduce complication rates.

Transitivity, coherence, and reliability of network meta-analyses comparing proximal humerus fracture treatments: a meta-epidemiological study.

BACKGROUND: Network meta-analyses can be valuable for decision-makers in guiding clinical practice. However, for network meta-analysis results to be reliable, the assumptions of both transitivity and coherence must be met, and the methodology should adhere to current best practices. We aimed to assess whether network meta-analyses of randomized controlled trials (RCTs) comparing interventions for proximal humerus fractures provide reliable estimates of intervention effects. METHODS: We searched PubMed, EMBASE, The Cochrane Library, and Web of Science for network meta-analyses comparing interventions for proximal humerus fractures. We critically assessed the methodology regarding the development of a protocol, search strategy, trial inclusion, outcome extraction, and the methods used to conduct the network meta-analyses. We assessed the transitivity and coherence of the network graphs for the Constant score (CS), Disabilities of the Arm, Shoulder, and Hand score (DASH), and additional surgery. Transitivity was assessed by comparing probable effect modifiers (age, gender, fracture morphology, and comorbidities) across intervention comparisons. Coherence was assessed using Separating Indirect from Direct Evidence (SIDE) (Separating Indirect from Direct Evidence) and the design-by-treatment interaction test. We used CINeMA (Confidence in Network Meta-analyses) to assess the confidence in the results. RESULTS: None of the three included network meta-analyses had a publicly available protocol or data-analysis plan, and they all had methodological flaws that could threaten the validity of their results. Although we did not detect incoherence for most comparisons, the transitivity assumption was violated for CS, DASH, and additional surgery in all three network meta-analyses. Additionally, the confidence in the results was 'very low' primarily due to within-study bias, reporting bias, intransitivity, imprecision, and heterogeneity. CONCLUSIONS: Current network meta-analyses of RCTs comparing interventions for proximal humerus fractures do not provide reliable estimates of intervention effects. We advise caution in using these network meta-analyses to guide clinical practice. To improve the utility of network meta-analyses to guide clinical practice, journal editors should require that network meta-analyses are done according to a predefined analysis plan in a publicly available protocol and that both coherence and transitivity have been adequately assessed and reported.

Comparative efficacy and safety of medical treatments for proximal humerus fractures: a systematic review and network meta-analysis.

BACKGROUND: Various surgical techniques and conservative therapies are useful tools for treating proximal humerus fractures (PHFs), but it is important to understand how to properly utilize them. Therefore, we performed a systematic review and network meta-analysis to compare and rank the efficacy and safety of medical treatments for PHF. METHODS: PubMed, Embase, the Cochrane Library, and the ClinicalTrials.gov databases were systematically searched for eligible randomized controlled trials (RCTs) from inception until June 2022. Conservative therapy-controlled or head-to-head RCTs of open reduction internal fixation (ORIF), intramedullary nailing (IMN), hemiarthroplasty (HA), and reverse total shoulder arthroplasty (RTSA) used for the treatment of adult patients with PHF were included. The surface under the cumulative ranking (SUCRA) probabilities were applied to compare and rank the effects of medical treatments for PHF. RESULTS: Eighteen RCTs involving 1,182 patients with PHF were selected for the final analysis. Mostly baseline characteristics among groups were well balanced, and the imbalanced factors only included age, injury type, medial comminution, blood loss, and cognitive function in single trial. The SUCRA probabilities found that RTSA provided the best effect on the Constant-Murley score (SUCRA: 100.0%), and the disabilities of the arm, shoulder and hand (DASH) score (SUCRA: 99.0%). Moreover, HA (SUCRA: 85.5%) and RTSA (SUCRA: 68.0%) had a relatively better effect on health-related quality of life than the other treatment modalities. Furthermore, conservative therapy (SUCRA: 84.3%) and RTSA (SUCRA: 80.7%) were associated with a lower risk of secondary surgery. Finally, the best effects on the risk of complications are varied, including infection was observed with conservative therapy (SUCRA: 94.2%); avascular necrosis was observed in HA (SUCRA: 78.1%), nonunion was observed in RTSA (SUCRA: 69.6%), and osteoarthritis was observed in HA (SUCRA: 93.9%). CONCLUSIONS: This study found that RTSA was associated with better functional outcomes, while the comparative outcomes of secondary surgery and complications varied. Optimal treatment for PHF should consider patient-specific factors.

3D printing assisted MIPO for treatment of complex middle-proximal humeral shaft fractures.

BACKGROUND: This study was designed to explore the clinical efficacy of 3-dimensional (3D) printing assisted minimally invasive percutaneous plate osteosynthesis (MIPO) technique by comparing the clinical outcomes with traditional open reduction and internal plating fixation (ORIF) for treating complex middle-proximal humerus fractures (AO 12C fracture type). MATERIALS AND METHODS: The data of 42 participants who received a complicated middle-proximal humerus fracture from the beginning of 2018 to the end of 2022 were retrospectively analyzed. All patients were assigned to two groups: MIPO with detailed preoperative planning assisted by 3D printing technique (MIPO group), and traditional ORIF (ORIF group). RESULTS: This study included 21 patients in the ORIF group and 21 patients in the MIPO group. All patients were followed-up for at least one year (mean: 16.12 ± 4.13 months), and no difference was observed in the range of shoulder joint motion (ROM), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores and Constant scores between the two groups. However, the occurrence of complications (surgical incision site infection, implant loosening, bone nonunion and radial nerve palsy) in ORIF group was remarkably higher compared to the MIPO group. All the cases achieved bone union within the MIPO group. Significant differences were found in surgical time, intraoperative blood loss and fracture healing time between the two groups. CONCLUSION: Preoperative 3D printing assisted MIPO technique exhibits obvious advantages in high operational efficiency and low occurrence of complications, which is worthy of clinical application for treating complex middle-proximal humeral shaft fractures.

Rare presentation of a primary intraosseous glomus tumor in the humerus of a teenager.

A glomus tumor is a benign mesenchymal tumor comprised of cells that resemble the perivascular modified smooth muscle cells of the glomus body. Glomus tumors typically appear in the superficial lesions of the soft tissue in the extremities, such as the subungual region. However, their occurrence in the bone is rare, with only about 30 cases reported to date. Half of these cases involved the distal phalanges of the fingers or toes, with only three reported cases involving the long bones. Here, we present the first case, a primary glomus tumor in the humerus of a 14-year-old female. An osteolytic and cystic lesion was detected after a pathological fracture occurred during exercise. Despite the tumor's large size, no pathological findings indicated malignancy. The fracture healed through conservative treatment, while the tumor was effectively managed with curettage. Appropriate medical care can be provided to patients by focusing on pathological findings.

Comparing long and intermediate-length plates for metastatic bone disease of the proximal humerus: A retrospective analysis.

AIMS: Managing proximal humerus pathologic fractures requires strategic planning to ensure optimal patient outcomes. Traditionally, fixation of the humerus using long devices has been considered the standard of care, but emerging evidence has challenged this approach. This study aimed to compare long plates (LPs) and intermediate-length plates (IPs) in this clinical context. METHODS: Forty-four patients with proximal humerus metastatic bone disease were retrospectively studied from 2013 to 2019, with 11 (25%) receiving long plates (LPs) and 33 (75%) intermediate-length plates (IPs). Outcomes included tumor progression, reoperation rates, postoperative anemia, blood loss, operation time, and hospitalization duration. Tumor progression was classified into three categories, with Type III progression (new metastatic lesions in the distal humerus) theoretically benefiting most from whole bone stabilization. RESULTS: Tumor progression occurred in three patients (7%), all of them was in IPs. No revision surgery was needed to address these tumor progressions, including one type III progression which occurred 34 months postoperatively after IP surgery. IP were associated with a reduced operation time compared with LP (median, 1.5 h [IQR, 1.2-1.9] vs. 2.4 [IQR, 1.7-2.5]; p = 0.004). No differences were found for the other perioperative outcomes. CONCLUSIONS: Our findings reveal a low incidence of tumor progression and low reoperation rates in both groups. The shortened operative time associated with IP use suggests its particular suitability for patients with limited life expectancy. Further research is needed to elucidate the ideal prosthesis length that best balances the risks and benefits when addressing proximal humerus metastatic disease.

The comparison of functional bracing of humeral shaft fractures: thermoplastic custom against preprepared commercial braces.

BACKGROUND: Functional humeral bracing of midshaft humeral fractures has been widely accepted as a gold standard for nonoperative treatment. Despite reported high union rates, there is no proven superiority of any orthosis. Here we aim to compare the outcomes after the use of custom-made thermoplastic vs. commercial humeral brace with regard to time to union, nonunion rates, types of nonunion, and conversion to surgery. METHODS: Patients with humeral fractures treated between 2018 and 2021 were identified retrospectively by electronic records. Only diaphyseal humerus fractures (AO 12) were included in the study. Proximal (AO 11) or distal (AO 13) fractures, open fractures, pathologic fractures, bilateral fractures, multiple fractures, and patients lost to follow-up were excluded. Patients attending one center received a custom-made thermoplastic splint, whereas those at the other center had an off-the-shelf humeral brace applied. Radiologic union was defined as healing of at least 3 of 4 cortices determined from follow-up radiographs. Data calculations were performed using the χ2 test. RESULTS: A total of 53 patients treated with a thermoplastic brace and 43 with a commercial brace were identified. A total of 52 men were included, and the cohort's mean age was 60.1 years (standard deviation: 16.1 years). Both groups had similar gender and age distributions. More patients achieved union with a thermoplastic brace (79.2%) than those with a commercial brace (76.7%), which was statistically significant (χ2, P = .04). Although time to union was similar both clinically and radiologically, patients with a commercial brace converted to surgical treatment more frequently (11 vs. 14 cases). CONCLUSION: Thermoplastic custom-made braces provide better fracture stability, allowing for statistically significantly higher rates of fracture union during a similar treatment period to commercially available splints. Patients wearing a commercial splint were significantly more likely to develop hypertrophic nonunion requiring surgery.

Surgical treatment of displaced proximal humerus fractures is associated with decreased 1-year mortality in patients aged 65 years and older: a retrospective study of Medicare patients.

BACKGROUND: Proximal humerus fracture (PHF) is a risk factor for 1-year mortality. This study aimed to determine if surgery is associated with lower mortality compared to nonoperative treatment following PHF in older patients. METHODS: This retrospective cohort study used the Medicare Limited Data set. Patients aged 65 years and older with a PHF diagnosis in 2017-2020 were included. Treatment was classified as nonoperative, open reduction internal fixation (ORIF), total shoulder arthroplasty (TSA), or hemiarthroplasty. Multivariable logistic regression models examined (a) predictors of treatment type and (b) the association of treatment type with 1-year mortality, adjusting for patient demographics, comorbidities, frailty, and fracture severity among other variables. A subgroup analysis examined how the relationship between treatment type and 1-year mortality varied based on fracture severity. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) are reported. RESULTS: In total, 49,072 patients were included (mean age = 76.6 years, 82.3% female). Most were treated nonoperatively (77.5%), 10.9% underwent ORIF, 10.6% underwent TSA, and 1.0% underwent hemiarthroplasty. Examples of factors associated with receipt of operative (versus nonoperative treatment) included worse fracture severity and lower frailty. The 1-year mortality rate after the initial PHF diagnosis was 11.0% for the nonoperative group, 4.0% for ORIF, 5.2% for TSA, and 6.0% for hemiarthroplasty. Compared to nonoperative treatment, ORIF (aOR 0.55; 95% CI [0.47, 0.64]; P < .001) and TSA (aOR 0.59; 95% CI [0.50, 0.68]; P < .001) were associated with decreased odds of 1-year mortality. In the subgroup analysis, ORIF and TSA were associated with a lower 1-year mortality risk for 2-part and 3-/4-part fractures. CONCLUSIONS: Compared to nonoperative treatment, surgery (particularly TSA and ORIF) was associated with a decreased odds of 1-year mortality. This relationship remained significant for 2-part and 3-/4-part fractures after stratifying by fracture severity.

Optimal Screw Orientation for Fixation of Coronal Shear Fractures: A Biomechanical Comparison.

OBJECTIVE: Coronal shear fractures of the capitellum are rare injuries which can be challenging to treat. The aim of this study was to compare the biomechanical properties of different internal screw fixation techniques for Dubberley type IA fractures of the capitellum. METHODS: In this biomechanical study, Dubberley type IA fractures of the capitellum were created in 30 human fresh-frozen humeri. The specimens were then divided into three groups: fixation was either performed with 3 x 3.0 mm headless cannulated compression screws (HCCSs) in anteroposterior (AP) orientation (AP group), 3 x 3.0 mm HCCSs in posteroanterior (PA) orientation (PA group) or with 2 x 3.0 mm HCCSs in PA orientation and 1 x 3.0 mm HCCS in lateral orientation (LAT group). Displacement under cyclic loading and ultimate load-to-failure were evaluated in all specimens. RESULTS: There was no significant difference in fragment displacement after 2000 cycles between AP and PA groups (0.8 ± 0.5 mm vs. 0.8 ± 0.6 mm; p = 0.987) or PA and LAT groups (0.8 ± 0.6 mm vs. 0.8 ± 0.3 mm; p = 0.966). LAT group showed the highest load-to-failure (548 ± 250 N) without reaching statistically significant difference to AP group (388 ± 173 N; p = 0.101). There was also no significant difference between AP and PA groups (388 ± 173 N vs. 422 ± 114 N; p = 0.649). CONCLUSIONS: Variations in screw placement had no statistically significant influence on cyclic displacement or load-to-failure in Dubberley Type IA fractures. However, fracture fixation in two planes - both the coronal and the sagittal plane - by adding a screw in a lateral to medial direction may be beneficial to increase primary stability.

Superior functional outcome following reverse shoulder arthroplasty compared to hemiarthroplasty for displaced three and four-part fractures in patients 65 and older: Results from a prospective multicentre randomised controlled trial - The Shoulder Hemiarthroplasty or Reverse Polarity Arthoplasty (SHeRPA) trial.

BACKGROUND: Acute unreconstructible 3- or 4-part proximal humerus fractures can be treated with hemiarthroplasty or reverse polarity shoulder arthroplasty. Randomized trials using implants from multiple different companies or uncemented implants have found superior results with reverse polarity arthroplasty. AIMS: This study aims to determine whether cemented reverse polarity arthroplasty produces a superior outcome compared to cemented hemiarthroplasty using one implant system in patients aged 65 years and over at 12 months follow-up as measured with the Constant score. METHODS: A prospective patient and assessor blinded multicenter randomized controlled trial was conducted of shoulder hemiarthroplasty or reverse polarity arthroplasty in patients aged 65 years and older with acute 3- and 4-part proximal humerus fracture not amenable to osteosynthesis. The primary outcome was the Constant score at 12 months with total follow-up to 24 months. Block randomization by site was undertaken using random number generation and sealed envelopes. Power analysis indicated that 17 patients were required in each arm to achieve 80% power with an alpha-value of 5%. Secondary outcome measures were the difference in the mean Constant Score, Quick Disabilities of the Arm Shoulder and Hand Questionnaire (QuickDASH), Oxford Shoulder Score (OSS), American Shoulder and Elbow Surgeons (ASES) Score and EQ5D-5L up to two years; differences in complication rate at one and two years; differences in revision and implant failure at one and two years. RESULTS: 18 patients were randomized to hemiarthroplasty and 18 to reverse polarity arthroplasty across 4 sites. The primary outcome as measured by the Constant score at 12 months was better in the reverse polarity shoulder arthroplasty (RSA) group (Mean 51.1, s.d. 14.9) compared to the hemiarthroplasty (HA) group (mean 35.0, s.d. 13.5) (p=0.004). No significant difference was reported at 24 months but this may be due to high rates of attrition (22%). The mean EQ-5D-5L patient rated health status score was significantly higher in the RSA group compared to the HA group at 12 months. One hemiarthroplasty was revised due to implant uncoupling and one reverse polarity shoulder replacement was revised due to instability. No other complications were recorded. DISCUSSION: Treatment of unreconstructible 3- or 4-part proximal humerus fractures with reverse polarity shoulder arthroplasty results in a superior outcome compared to shoulder hemiarthroplasty at 12 months measured with the Constant score with no increased risk of failure up to 24 months in patients age 65 years and over. High attrition rates are observed in this older population due to cognitive decline and death from other causes.

Reconstruction of the elbow with distal humerus endoprosthetic replacement after tumor resection: a systematic review of the literature and institutional case series.

BACKGROUND: Distal humerus replacement (DHR) is a modular endoprosthesis mainly used for bone reconstruction after resection of primary or metastatic bone lesions. Studies on DHR failure rates and postoperative functional outcomes are scarce. We sought to assess implant survival, modes of failure, and functional outcomes in patients undergoing DHR for oncologic indications. METHODS: A systematic review of the PubMed and Embase databases was performed. PRISMA guidelines were followed for this manuscript. Our study was registered on PROSPERO (457,260). Quality appraisal of included studies was conducted using the STROBE checklist. Prosthetic failure was assessed using the Henderson classification for megaprosthetic failures. We additionally performed a retrospective review of patients treated with a DHR for oncologic indications at a large tertiary care academic center. Weighted means were calculated to pool data. RESULTS: Eleven studies with a total of 162 patients met the inclusion criteria. Mean follow-up was 3.7 years (range, 1.66-8 years). Henderson type 2 failures (aseptic loosening) were the most common mode of failure, occurring in 12% of cases (range, 0%-33%). Five-year implant survival was 72% (range, 49%-93.7%). Mean postoperative Musculoskeletal Tumor Society (MSTS) score was 81.1 (range, 74-84.3). In our institutional case series, 2 out of 5 patients had DHR revision for periprosthetic fracture and aseptic loosening at 16 and 27 months after surgery, respectively. CONCLUSIONS: Distal humerus replacement is a successful reconstruction strategy for tumors of the distal humerus, with high implant survival and good to excellent functional outcomes.

Trends in the treatment of proximal humerus fractures from 2010 to 2020.

BACKGROUND: The incidence of proximal humerus fractures (PHF) is continuing to rise due to shifts towards a more aged population as well as advancements in surgical treatment options. The purpose of this study is to examine and compare trends in the treatment of PHFs (nonoperative vs. operative; different surgical treatments) across different age groups over the last decade (2010-2020). METHODS: The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried using International Classification of Diseases and Current Procedural Terminology codes to identify all patients presenting with or undergoing surgery for PHF between 2010 and 2020. Treatment trends, demographics, and insurance information were analyzed during the study period. Comparisons were made between operative and nonoperative trends with respect to the number and type of surgeries performed among 3 age groups: ≤49 years, 50-64 years, and ≥65 years. The rate of postoperative complications and reoperations was evaluated and compared among different surgical treatments for patients with a minimum 1-year postoperative follow-up. RESULTS: A total of 92,308 patients with a mean age of 67.8 ± 16.8 years were included. Over the last decade, there was no significant increase in the percentage of PHFs treated with surgery. A total of 15,523 PHFs (16.82%) were treated operatively, and these patients, compared with the nonoperative cohort, were younger (64.9 years vs. 68.4 years, P < .001), more likely to be White (80.2% vs. 74.7%, P < .001), and more likely to have private insurance (41.4% vs. 32.0%, P < .001). For patients ≤49 years old, trends in operative treatment have remained stable with internal fixation (IF) as the most used surgical modality. For patients 50-64 years old, we observed a gradual decline in the use of hemiarthroplasty (HA), with a corresponding increase in the use of reverse total shoulder arthroplasty (rTSA), but IF continued to be the most used operative modality. In patients over 65 years, a steep decline in the use of IF and HA was noted during the first half of the decade along with a significant exponential increase in the use of rTSA, which surpassed the use of IF in 2019. Despite the increase in the use of rTSA, no differences in rate of surgical complications were noted between rTSA and IF (χ2 = 0.245, P = .621) or reoperations (χ2 = 0.112, P = .730). CONCLUSION: Nonsurgical treatment remains the mainstay treatment of PHFs. Although there is no increase in the prevalence of operative treatment in patients ≥50 years in the last decade, there is an exponential increase in the use of rTSA with a corresponding decrease in HA and IF, a trend more substantial in patients ≥65 years compared with patients between 50 and 64 years.