Partial Fracture Research Articles

Investigation of surface integrity transition of SiCp/Al composites based on specific cutting energy during ultrasonic elliptical vibration assisted cutting

Different from brittle materials or homogeneous metal materials, there is no obvious characteristic of brittle removal or plastic removal in machining of particle reinforced metal matrix composites (MMCs). In the present work, we investigate the surface integrity transition of SiCp/Al composites during ultrasonic elliptical vibration-assisted cutting (UEVC). The machined surface is divided into two parts: plastic deformation of metal matrix and defects caused by particle deformation. A specific-cutting-energy-based criterion based on the relationship between plastic deformation and defects formation, is established to characterize the surface integrity transition of SiCp/Al composites quantitatively. The effectiveness of the critical cutting parameter is verified by systematic experiments. Experimental results show that the surface integrity transition of SiCp/Al composites is mainly affected by processing method and cutting speed. When the scratching speed increases from 100 mm/min to 200 mm/min, the main part of machined surface changes from defects to plastic deformation accordingly in UEVC. The ductile surface of SiCp/Al composites can be obtained when the cutting speed, cutting depth and feed rate are 100 mm/min, 0.01 mm and 0.02 mm/rev, respectively. According to the experimental results, particle partial fracture, debonding and micro-deflection dominate particle removal process in UEVC, which is also the main reason why UEVC can improve the machinability of SiCp/Al composites.

Understanding postoperative rehabilitation preferences in operatively managed proximal humerus fractures: do trauma and shoulder surgeons differ?

Proximal humerus fractures (PHFs) are common, and their incidence is increasing as the population ages. Despite this, postoperative rehabilitation remains unstandardized and little is known about surgeon preferences. The aim of this study was to assess differences in postoperative rehabilitation preferences and patient education between orthopedic trauma and shoulder surgeons. An electronic survey was distributed to members of the Orthopaedic Trauma Association and the American Shoulder and Elbow Surgeons to assess differences in postoperative rehabilitation preferences and patient counseling. Descriptive statistics were reported for all respondents, trauma surgeons, and shoulder surgeons. Chi-square and unpaired 2-sample t tests were used to compare responses. Multinomial regression was used to further elucidate the influence of fellowship training independent of confounding characteristics. A total of 293 surgeons completed the survey, including 172 shoulder and 78 trauma surgeons. A greater proportion of trauma surgeons preferred an immediate weightbearing status after arthroplasty compared to shoulder surgeons (45% vs. 19%, P=.003), but not after open reduction and internal fixation (ORIF) (62% vs. 75%, P=.412). A greater proportion of shoulder surgeons preferred home exercise therapy taught by the physician or using a handout following reverse shoulder arthroplasty (RSA) (21% vs. 2%, P=.009). A greater proportion of trauma surgeons began passive range of motion (ROM) <2 weeks after 2-part fractures (70% vs. 41%, P<.001). Conversely, a greater proportion of shoulder surgeons began passive ROM between 2 and 6 weeks for 2-part (57% vs. 24%, P<.001) and 4-part fractures (65% vs. 43%, P=.020). On multinomial regression analysis, fellowship training in shoulder surgery was associated with preference for a nonweightbearing duration of >12 weeks vs. 6-12 weeks after ORIF. Similarly, fellowship training in shoulder surgery was associated with increased odds of preferring a nonweightbearing duration of <6 weeks vs. no restrictions and >12 weeks vs. 6-12 weeks after arthroplasty. Training in shoulder surgery was associated with greater odds of preferring a nonweightbearing duration prior to beginning passive ROM of 2-6 weeks vs. <2 weeks or >6 weeks for 2-part fractures, but not 4-part fractures. Trauma surgeons have a more aggressive approach to rehabilitation following operative PHF repair compared to shoulder surgeons regarding time to weightbearing status and passive ROM. Given the increasing incidence of PHFs and substantial variations in reported treatment outcomes, differences in rehabilitation after PHF treatment should be further evaluated to determine the role it may play in the outcomes of treatment studies.

Operative Treatment of Proximal Humeral Fractures with Reverse Total Shoulder Arthroplasty in Patients ≥65 Years Old: A Critical Analysis Review.

The majority of proximal humeral fractures (PHFs) in patients who are ≥65 years of age are treated nonoperatively, but certain complex fracture patterns benefit from surgical intervention. However, there continues to be debate regarding the indications for surgery and the optimal surgical treatment (repair versus replacement) in this population. Reverse total shoulder arthroplasty (RTSA) has grown in popularity for surgical treatment of fracture-dislocations and displaced complex PHFs in patients who are ≥65 years of age; it has definite advantages over surgical repair and hemiarthroplasty, but this finding requires additional higher-quality evidence. RTSA provides early pain relief and return of shoulder function as well as predictable elevation above shoulder level in the forward plane, but the indications for and understanding of the effect of timing on RTSA after a PHF continue to evolve. RTSA for an acute PHF is indicated in patients who are ≥65 years of age with 3- and 4-part fracture-dislocations, head-split fractures, and severely displaced fractures, and is an option in patients who are not able to tolerate nonoperative treatment of severely displaced 3- and 4-part fractures. RTSA is also indicated as a salvage operation for PHFs that have failed initial surgical repair (i.e., fixation failure, implant failure, rotator cuff failure, or osteonecrosis) and is an option for symptomatic nonunion or malunion after nonoperative treatment.

Modified Posterolateral Approach for the Treatment of 2-Part Fractures of the Posterior Malleolus Associated with Medial and Lateral Malleolar Fractures: 1 Incision, 2 Windows, 3 Steel Plates.

BackgroundThe aim of this study was to investigate the effect of the modified posterolateral approach using 1 incision, 2 windows, and 3 plates in the treatment of 2-part posterior malleolus fractures complicated with medial and lateral malleolus fractures.Material/MethodsTwelve patients with 2-part fractures of the posterior malleolus complicated with medial and lateral malleolar fractures and treated by the modified posterolateral approach from January 2018 to January 2021 were studied retrospectively. After surgery, the ankle hindfoot score and visual analog scale (VAS) of the American Orthopedic Foot and Ankle Society (AOFAS) were used for evaluation.ResultsThe average follow-up time of the 12 patients was 18 months (7–30 months). All patients had no infection, and their incisions healed in the first stage. Postoperative radiography showed that the average fracture healing time was 12.5 weeks (10–15 weeks). The average time for patients to walk weight bearing was 13 weeks (11–16 weeks), and there was no obvious pain or discomfort. At the last follow-up, the average AOFAS ankle hindfoot score of the 12 patients was 87.5 (77–95), with 7 excellent and 5 good scores. The VAS score improved from before surgery (average 8.25 points) to after surgery (average 1 point). The curative effect was satisfactory.ConclusionsThe posterolateral approach using 1 incision, 2 windows, and 3 steel plates was effective in the treatment of 2-part posterior malleolus fractures complicated with medial and lateral malleolus fractures.

Comparative study between delto-pectoral and deltoid splitting approach in surgical treatment of proximal humerus fractures using philos plating

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The present study was done to compare the two approaches of proximal humerus PHILOS plating on the basis of functional outcome of patients and other perioperative parameters.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 40 patients with type 2 and type 3 proximal humerus were assigned to group A and B pre-operatively using random alternate allocation. Patients in group-A were operated with deltoid splitting approach while patients in group-B were operated with delto-pectoral approach. Functional outcome was assessed at 6 weeks, 3-months and 6-months. Perioperative parameters like duration of surgery, associated complications, and hospital stay were also noted and compared.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In each group, there were 12 two-part fractures and 8 three-part fractures. For 2-part fractures the mean duration of surgery was 51.33 min for group A and 63.37 min for group B. While for 3-part fractures it was 67.5 min and 80 min respectively. Irrespective of fracture type, there was statistically significant difference between the constant scores in both groups at 3 months (2-part: group A: 67.67; group B: 44.7; p value=0.001. 3-part: group A: 66; group B: 48; p value=0.001). However, the difference between two groups at 6 months was not statistically significant.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Both approaches show satisfactory outcomes over a long period. However, the significantly less operative time and minimal soft tissue dissection in deltoid splitting approach can be used as an advantage in particular cases. Moreover, there was an early return to day-to-day activities for the deltoid splitting group which should be considered when treating an active individual.&lt;/p&gt;

Endosteal plating in proximal humerus fractures: a novel technique and alternative to fibular strut allograft for medial column support

The purpose of this retrospective study is to investigate the clinical and radiographic outcomes associated with the use of a standard metal plate as an endosteal implant in combination with a lateral locking plate to treat 4 patients with displaced proximal humerus fractures. A retrospective case series study design was utilized, and the medical records of 4 patients with displaced, 3-part proximal humerus fractures treated using this technique between January 2019 and July 2021 were reviewed for this study. The mean age was 52 years (range, 44-57 years). The radiographic outcome of interest was humeral neck-shaft angle preoperatively, intraoperatively, and at the latest follow-up. The average follow-up duration was 62 weeks (range, 12-161 weeks). All fractures healed without loss of reduction or neurovascular deficits. Avascular necrosis was not observed in the 2 patients with sufficient follow-up time to make such an evaluation. The average neck-shaft angles preoperatively, intraoperatively, and at the latest follow-up were 104.8°, 139.8°, and 137°, respectively. Locking plate technology augmented with an endosteal plate provided stable reduction and restoration of physiologic alignment in a small number of patients with displaced proximal humerus fractures. This construct creates a second column of fixation, providing medial column support, and could be removed in the event of a future revision to a reverse shoulder arthroplasty.

Deformation and fracture behavior in TRIP steels under static and dynamic tensile conditions

The present study sought to explore the deformation and fracture behavior of Quenching and Partitioning (Q&P) steel at five different strain rates (10−4 s−1, 1 s−1, 10 s−1, 100 s−1 and 1400 s−1). Tensile tests were carried out on Q&P steel at different strain rates, and the deformation and fracture behaviors were explored through digital image correlation (DIC) and scanning electron microscope (SEM). The results indicated that the strength and plasticity of Q&P steel had significant strain rate sensitivity. The yield strength and ultimate strength increases continuously, whereas the elongation first decreased and then increased with increase in strain rate. The dimples gradually became smaller and flatter with increase in strain rate. The dislocation density increased when strain rate was above 100 s−1, indicating that resistance to dislocation slip increases and the slip distance becomes shorter at high strain rates, which inhibits generation of large deformation. The local plastic strain at the fracture significantly decreased from 0.7 to 0.3, resulting in partial brittle fracture characteristics in fracture morphology. These findings provide a basis for further elucidating the deformability and fracture behavior of Q&P steel at different strain rates.

Outcomes of Reverse Total Shoulder Arthroplasties Performed for Proximal Humeral Fractures Versus Elective Etiologies.

Reverse Total Shoulder Arthroplasty is commonly performed for elective indications, such as cuff tear arthropathies, salvage arthropathies and tumours with excellent outcomes. However, its use in treating acute conditions such as 3- and 4-part proximal humeral fractures in the elderly has been more controversial. The aim of our study is to directly compare the short-term intra-operative and post-operative outcomes of RTSA for traumatic proximal humeral fractures as compared to elective shoulder arthroplasty. We retrospectively identified 78 consecutive patients who had undergone RTSA from 2009 to 2018 at a tertiary hospital. These patients were classified by etiology as either elective or trauma cases. Comparative analysis of the baseline demographics, as well as post-operative surgical, functional and range-of-movement outcomes between the two groups was performed. 57 Patients made up the elective cohort and 14 patients made up the trauma cohort. The elective cohort was significantly older compared to the traumatic fracture cohort (73.2 vs 78.6, p = 0.026). No significant differences were observed when comparing post-operative surgical outcomes. At 6months, the elective cohort demonstrated greater forward flexion (105.8° vs 127.2°, p = 0.041), as well as higher SF-36 PCS (27.85 vs 43.99, p = 0.018) and ASES scores (35.5 vs 76.31, p = 0.009). However, these differences resolved by 1-year post-op and no significant differences were noted comparing functional and range-of-movement outcomes at 1-year post-op. Our study suggests that the application of reverse total shoulder arthroplasty in the management of traumatic humeral fractures may produce similarly favourable 1-year outcomes to that performed for elective etiologies. The online version contains supplementary material available at 10.1007/s43465-022-00625-4.

The Functional and Radiological Outcome of Hoffa's Fracture Treated With Cannulated Cancellous Screws.

Introduction: Distal femur AO type 33 B fractures consist of partial articular fractures subdivided into three types namely sagittal lateral condyle fracture, medial condyle fracture, and coronal split fracture. Coronal plane fractures of the distal femur are less frequent compared to sagittal plane fractures and are known as Hoffa fractures. The mechanism of injury is usually a direct anteroposterior force to the flexed and abducted knee for lateral condylar fractures and a direct impact on the medial side of the knee in flexion for a medial condylar fracture. Various approaches like lateral parapatellar for lateral condylar Hoffa's fixation, with or without posterior approach for open reduction of Hoffa's fracture with screw or buttress plate fixation, medial parapatellar approach for medial condylar Hoffa's fracture screw fixation are used.Materials and Methods: This study was conducted at R L Jalappa Hospital and Research Center attached to Sri Devaraj Urs Medical College, Kolar, India, from June 2017 to May 2020 with 17 patients as a sample size.Results: Seventeen patients with Hoffa's fracture were treated with cannulated cancellous screws with lag effect including 12 males and five females with a mean age of 31.1 years. The range of motion ranged from 120 to 135 degrees of flexion with a mean of 125.2 degrees. Three patients had extensor lag ranging from 5 to 10 degrees with an average of 6.3 degrees. Neer scores were excellent in 11, good in four, and fair in two patients. The average fracture union time for the lateral condyle was 16.4 months and for the medial condyle, it was 16.7 months.Conclusion: Restoration of articular anatomy and its congruence is of paramount importance for better surgical outcomes. Closed or open reduction and stable fixation with anteroposterior cannulated cancellous screws are essential. A good post-operative rehabilitation program is required for better outcomes.

AESTHETICS WITH NATURAL TOOTH VENEER: A CASE REPORT

Among the various treatment options, reattachment of a crown fragment is a conservative treatment that can be considered for crown fractures of anterior teeth. The procedure is simple, economic, conserves tooth structure and needs less chair-side time as compared to conventional methods. This procedure is an interim type of treatment for immediate restoration of aesthetics till a more permanent treatment is planned. Advantages of the fragment reattachment is that all the alternative methods such as direct adhesive resin reconstruction, veneers and crowns can be performed in case of failure. This clinical case report describes the management of a permanent maxillary central incisor which had undergone partial crown fracture during endodontic treatment.

Vascularized bone flaps for trauma induced bone defects of the upper extremity in young adults: Presentation of two cases

Nonunions after complex upper extremity injury in young adults may result in diminished function, pain and decreased quality of life. The use of vascularized bone flaps is challenging. However, it offers the most bone healing stimulating properties in revision surgery. First, we describe the case of a young man with complex open wrist injury. He developed an osteoarthritis of the wrist, with abundant bone loss of the distal radius, ulna and carpal bones. He underwent wrist arthrodesis with the use of a vascularized iliac crest bone flap. Secondly, the case of a young woman is presented following a 4-part luxation fracture of the proximal humerus. She developed a nonunion with concomitant avascular necrosis. A reconstruction with plate fixation and a vascularized fibula flap was performed. In our cases, the use of vascularized autologous bone flaps resulted in union and a good clinical outcome. In literature, scarce evidence is present on the indications, procedure specifics, complications, clinical outcome, and patient related outcome measurements of the use of vascularized bone flaps for posttraumatic bone defects of the upper limb. This is likely due to the heterogeneity and scarcity of the patient population. The use of vascularized bone flaps is a viable treatment option for patients with complex nonunions of the upper extremity. • Impaired fracture healing of the upper extremity results in diminished functional outcome. • The use of vascularized bone flaps is an important option in revision surgery. • Vascularized fibula flaps and iliac crest flaps have good bone healing properties. • Osteoconductivity, osteoinductivity, osteogenicity and structural support determine the effectiveness of the graft.

Stretched to the Limit: Comparing Polytetrafluoroethylene-Covered Endovascular Stents Through Serial Dilations

BackgroundCovered stents are used during congenital cardiac interventions to treat stenotic or injured vessels or to exclude unwanted vascular connections. The ability to postdilate a stented vessel to keep pace with somatic growth is critical in children. In this study, we aimed to compare in vitro performance of 2 brands of covered stents during serial dilations to demonstrate the threshold for stent fracture and polytetrafluoroethylene tear and define recoil and foreshortening characteristics. MethodsiCast and VBX stents of various sizes were measured before and after expansion and through serial dilations. Dilations were performed at 2-mm increments until stent fracture, polytetrafluoroethylene tear, and “napkin-ring” formation, to a maximum of 22-mm diameter. ResultsThe 5- and 6-mm VBX stents fractured during dilation with 10-mm balloon; the 7-mm VBX stents fractured on the 14-mm balloon; and the largest VBX stents fractured on the 20- or 22-mm balloons. iCast stents experienced partial fracture during dilation with the 14- or 16-mm balloons and complete fracture past dilation with 16-mm balloons. VBX stents recoiled less at nominal diameters. Both stents had similar foreshortening at nominal diameters, although VBX stents had more significant foreshortening with postdilation. ConclusionsAll iCast stents experienced partial fracture with dilation between 14- and 16-mm diameter and had unpredictable fracturing patterns. VBX stents showed a more predictable fracture pattern and had less recoil with nominal inflation but more foreshortening with postdilation. These findings may add clinical benefit and empower physicians to make optimal decisions regarding future planning of interventions in children with congenital heart disease.

Incidence and risk factors for pseudosubluxation of the humeral head following proximal humerus fracture.

BackgroundHumeral head pseudosubluxation (HHPS) in relation to the glenohumeral joint is a common finding following fractures of the proximal humerus. The temporary inferior subluxation of the humeral head may be secondary to a transient axillary nerve neuropraxia, pain inhibition of the deltoid, or hemarthrosis or capsular disruption that alters the physiologically negative pressure in the glenohumeral joint. Despite the frequency of this finding, it is not well described in the literature. This study sought to describe the incidence, risk factors, and rate of resolution of HHPS following proximal humerus fracture.MethodsThe practice of two fellowship-trained shoulder and elbow surgeons was queried for proximal humerus fractures. Patient radiographs were reviewed at the time of injury and all subsequent follow-ups through one year after injury. Data collection included the presence of HHPS, type of fracture based on the Neer classification, operative vs. nonoperative management, and resolution of HHPS. Exclusion criteria included skeletally immature patients, fracture-dislocations, patients treated with reverse shoulder arthroplasty, inadequate follow-up, or those patients with incorrect International Classification of Diseases coding.ResultsThe incidence of HHPS was 20.0% (103 out of 515 patients) overall. Patients who required surgical intervention were more likely to develop pseudosubluxation than those who were treated conservatively (P < .001). There was an increasing incidence of pseudosubluxation based on the Neer classification, with 0-part fractures demonstrating a 2.56% (2/78) rate, whereas 4-part fractures were found to have HHPS in 35.1% (20/57) of cases (P < .001). All patients were found to have resolution of their HHPS at the final follow-up or one year after injury. None of age, sex, obesity, or injury to the dominant arm was associated with the occurrence of HHPS. There was, however, a statistically significant difference in the body mass index of those who developed HHPS (28.4, ± 5.77) vs. those who did not (26.2, ± 5.32, P < .01).ConclusionThis retrospective radiographic study is the largest to date investigating the incidence of HHPS following proximal humerus fracture and first to correlate with Neer classification and operative intervention. We found that HHPS occurs in one-fifth of acute proximal humerus fractures and resolves regardless of intervention. More complex fractures, including those with increasing Neer parts or requiring operative intervention, developed HHPS at higher rates than simpler fracture patterns. This study will help both general orthopedists as well as shoulder surgeons understand the epidemiology of HHPS and provide reassurance to patients that PS is a benign finding with expected spontaneous resolution by one year.

Primary Arthroplasty or Internal Fixation in Intertrochanteric Femur Fractures: A Survey of Surgical Attitudes of Orthopedic Surgeons in Turkey.

This study aimed to examine the primary arthroplasty attitudes of Turkish orthopedics and traumatology specialists and residents to patients with intertrochanteric fractures, of various ages, comorbidity situations and fracture types, using an internet-based questionnaire. Between March and April 2021, a cross-sectional survey was conducted with a total of 159 orthopedics and traumatology specialists and residents in Turkey, using an online questionnaire that consisted of 16 different patient scenarios of varying intertrochanteric fracture types, ages, and comorbidity conditions. Respondents’ preference ratio for primary arthroplasty was 24.1% in the scenarios with patients over the age of 71, while it was 8.4% in the scenarios with patients aged between 50 and 70. The ratios of primary arthroplasty preference were 12.4%, 21% and 27.3% in 2-part, 3-part and 4-part fracture scenarios, respectively. The primary arthroplasty preferences of respondents with 10 years or more of professional experience were observed to be statistically significantly different to those of the respondents with 1 to 10 years of experience in the 4-part fracture scenario where the patient was aged 71 years and above with an ASA (American Society of Anesthesiologists) score of 3–4 (p < 0.05). Despite varying opinions in the literature in recent years, primary arthroplasty can be considered a valuable alternative approach for Turkish surgeons, and in older adult patients with unstable intertrochanteric fractures, particularly those who need early mobilization and have high ASA scores.

ЛАБОРАТОРНОЕ ИЗУЧЕНИЕ АДГЕЗИВНЫХ МОСТОВИДНЫХ ПРОТЕЗОВ В БОКОВЫХ ОТДЕЛАХ ЗУБНЫХ РЯДОВ. ЧАСТЬ 2. МЕХАНИЧЕСКИЙ ЭКСПЕРИМЕНТ

Background. To date, numerous retrospective studies on the use of resin-bonded fixed partial dentures (RBFPD) have proven their reliability. Nevertheless, there are still questions about the design of posterior resin-bonded fixed partial dentures for replacing 1 and 2 missing teeth.&#x0D; Objectives. The present research was an in vitro study of the fracture strength of resin-bonded fixed partial dentures (RBFPD) with movable connector on the heat-pressed ceramic minor retainer when replacing 1 or 2 missing premolars. &#x0D; Methods. The laboratory research was carried out to study the fracture strength of fixed/movable RBFPD on acrylic moulds with a space equivalent to one or two premolars. The nature of RBFPD destruction and breaking loads in newtons were assessed by comparing the mean values according to the t-test. We studied 4 groups of RBFPD, depending on the type of retainer and the number of lost teeth.&#x0D; Results. The smallest fracture strength (1017.0 ± 49.0 N) was observed in the group with two missing teeth. In groups with 1mm thick occlusal rest, its deformation was observed. In the groups with 2 mm thick occlusal rest, partial fracture of the ceramic minor retainer was observed. Fixation loss of the adhesive wings or cast crowns as a large retainer was not observed. &#x0D; Conclusions. Fixed/movable RBFPD replacing two missing premolars are less fracture resisted then when replacing one missing premolar. Fixation loss of the large retainers was not observed. Adhesive wings were as effective as cast crowns as a large retainer.

A retrospective analysis of complex proximal humerus fractures managed with reverse shoulder arthroplasty in a level 1 trauma center

BackgroundThe treatment of complex 3- and 4-part proximal humerus fractures (PHFs) in the elderly poses significant challenges because of osteoporosis and fracture comminution. The wide range of surgical options available is evidence of the complex nature of the injury. At present, reverse shoulder replacement is gaining popularity among shoulder surgeons for treating these difficult fractures, and the literature has shown equivalent or superior outcomes with reverse shoulder arthroplasty (RSA). We aimed to analyze the long-term results of these complex PHF treated with reverse shoulder replacement. MethodsFor this study, fractures from 39 patients with a mean age of 63.18 years who were treated with RSA for acute complex fractures of the proximal humerus in our institution between 2013 and 2019 were analyzed (n = 31, acute 4-part fractures; n = 4, acute fracture–dislocation; n = 3, fracture with irreparable cuff tear; n = 1, osteoporotic 2-part fracture). All patients had a standard reverse shoulder replacement (cemented humeral stem n = 37 and uncemented stem n = 2) surgery in a level 1 trauma center. The mean follow-up duration was 60 months (24-111 months). The clinical outcomes (Oxford Shoulder Score and Constant Shoulder Score) and the complications at 6 months, 12 months, and 24 months were analyzed. ResultsOur study found a relatively younger population, with 21 patients (53.84%) aged <66 years. Spearman's correlation showed that younger patients had better signs of improvement in Oxford Shoulder Scores at 2 years (P = .008). The average Oxford Shoulder Score was 39.12 ± 4.327, and the average Constant Shoulder Score was 67.67 on the operated side. The mean active forward elevation was 142.56 ± 22.29º, abduction was 136.538 ± 24.31º, external rotation was 27 ± 9.011º, and internal rotation was 33 ± 20.41º. The overall complication rate of 17.94% (periprosthetic infection n = 2, periprosthetic humerus fracture n = 1, and hematoma evacuation n = 4) in our study was similar to those of recent studies in the literature. ConclusionRSA provides a reliable option for PHFs and offers good results in the form of pain relief and good functional outcomes at 2 years even in a younger age group. Thus, it is fast becoming an important option in treating complex PHF, but we must be wary of the steep learning curve and the complications pertinent to this procedure.

Experimental investigation of friction stir spot welding of polymer-aluminum alloy weldments

The friction stir spot welding (FSSW) process is one of the main solid-state joining methods used widely for welding different materials and dissimilar metals. In this article, the welding of Polytetrafluoroethylene (PTFE) and aluminum alloy sheets by the FSSW process will be investigated experimentally. The joining of polymer (PTFE) and metal (AA1050 aluminum alloy) was done successfully. The effect of process parameters including tool rotational speed, penetration depth, initial holding time, dwell time, and tool shoulder diameter on the joint strength and elongation of the weldments will be studied using response surface methodology (RSM). The joint strength was increased by creating a threaded hole in the aluminum sheet. A mechanical lock was created between the softened PTFE and the edge of the threaded hole. The shear-tensile tests have been carried out for 32 designed experiments. The results show that the joint strength increased by increasing the initial holding time due to the better wettability of PTFE and aluminum sheet. The joint strength increased by increasing the tool rotational speed and tool diameter (better pouring of the hole and formation of the mechanical lock). Two different fracture modes have been observed in the samples: (1) fracture in the peripheral area of the joint (partial interfacial fracture mode) and (2) fracture in the mechanically locked area (pull-out mode with tearing).

Parametric Experimental Study of Ultra-Short Stud Connections for Lightweight Steel–UHPC Composite Bridges

This paper reports on double shear push-out tests conducted on steel-to-ultra-high-performance concrete (UHPC) connections based on studs of 30- or 22-mm diameter in slabs of 35, 55, or 150 mm thickness. The results show that with an increase in stud diameter, the longitudinal shear strength has improved by 25% and 94% for ultra-short and long studs (of aspect ratios below and equal to 4.0), respectively. For short studs, both the aspect ratio and concrete cover greatly influenced failure by partial stud fracture or UHPC pryout, while the diameter governed failure behavior for long studs. Decreases in aspect ratio and cover thickness caused shear resistance to drop by 40% and 7%, respectively, for 30- and 22-mm diameter studs. Regression analyses show that the shear strength, slip stiffness, and ductility of the connections are exponential, sinusoidal, and polynomial functions, respectively, of the stud aspect ratio. The ultra-short stud–UHPC connections are 62% stiffer in slip than their normal concrete counterparts. Future work should entail fatigue testing of the connections.

Anatomical study for the treatment of proximal humeral fracture through the medial approach

BackgroundThe treatment of complex 3- and 4-part proximal humeral fractures has been controversial due to numerous postoperative complications. With the further study of medial support and blood supply of humeral head, new techniques and conception are developing. The study aims to illustrate the medial approach of the proximal humeral fracture through cadaver autopsy.MethodUpper limbs from 19 cadavers have been dissected to expose the shoulder joint. We selected the coracoid process as the bony reference. Vernier caliper will be used to measure the following data, including distance from coracoid process to circumflex brachial artery, distance between anterior humeral circumflex artery (ACHA) and posterior circumflex brachial artery (PCHA) and their diameters. Assessment included the characteristics of the vascular supply around the humeral head, identification of the structures at risk, quality of exposure of the bony structures, and feasibility of fixation.ResultsThe medial approach is appropriate in 86.84% anatomical patterns. Between the lower part of the shoulder capsule and the insertion of conjoined tendon, the bony surface exposed was limited by the interval between ACHA and PCHA. An interval of 2 to 3 cm (24.29 ± 3.42 mm) was available for medial plate. ACHA (49.35 ± 8.13 mm, 35.14–68.53 mm) and PCHA (49.62 ± 7.82 mm, 37.67–66.76 mm) were about 5 cm away from the coracoid process. Risk structures including ACHA and PCHA originate in common, PCHA originated from the deep brachial artery (DBA), the presence of perforator vessels, musculocutaneous nerve intersects with ACHA, the diameter of PCHA: ACHA < 1.5. In 13.15% anatomical patterns, this risk structure should be taken seriously.ConclusionThe medial approach opens a new perspective in the optimal management of complex fractures of proximal humerus. Anatomical research proves that the medial approach is feasible. The interval between ACHA and PCHA is suitable for placement. Anatomical pattern and indication have been discussed, and we hypothesized that ACHA has been destroyed in complex PHFs. With further studies on the anatomy and mechanism of injury, the development of more clinical cases will be an important work of our institution in the future.

Clinical outcomes of reverse total shoulder arthroplasty for elective indications versus acute 3- and 4-part proximal humeral fractures: a systematic review and meta-analysis.

Reverse total shoulder arthroplasty (RTSA) has continued to increase in clinical utility and popularity as an effective treatment for cuff tear arthropathy (CTA), irreparable rotator cuff tears (RCTs), osteoarthritis, and acute 3- and 4-part proximal humeral fractures. Performing RTSA for acute proximal humeral fractures presents the unique challenges of tuberosity management, bone loss, and instability compared with elective indications such as CTA or irreparable RCTs. The purpose of this study was to compare the clinical outcomes, active range of motion (ROM), radiographic outcomes, and complications between patients undergoing elective RTSA (RTSA-E) and those undergoing RTSA for fracture (RTSA-F). A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We queried 3 electronic databases (Embase, Cochrane, and PubMed) using the search term "reverse" AND "shoulder" AND "arthroplasty." Studies investigating the clinical outcomes of RTSA for traumatic and/or elective indications were included. Studies were excluded if they included RTSA performed for fracture sequelae, inflammatory arthritis, post-traumatic osteoarthritis, or avascular necrosis. Data collected included patient demographic characteristics, subjective outcome measurements, ROM, and complications. The pooled means and proportions along with their 95% confidence intervals were generated by a random-effects model that incorporated the between-study variations in weighting. A total of 134 studies (11,651 shoulders) investigating the clinical outcomes of RTSA-E patients and 66 studies (3117 shoulders) investigating RTSA-F patients were included in this systematic review. Analysis of patient-reported outcomes demonstrated that RTSA-F patients experienced significantly lower Constant scores than RTSA-E patients; however, relative Constant scores, Simple Shoulder Test scores, Disabilities of the Arm, Shoulder and Hand scores, American Shoulder and Elbow Surgeons scores, and visual analog scale pain scores were similar. RTSA-F patients also had significantly lower forward elevation, abduction, and external rotation. RTSA-F patients experienced tuberosity complications at a significantly higher rate than RTSA-E patients (25.9% vs. 4.1%). There was no significant difference between the 2 groups in terms of other complications such as heterotopic ossification, radiographic loosening, revision, nerve injury, postoperative stiffness, infection, dislocation, and component loosening. RTSA performed for acute 3- and 4-part proximal humeral fractures yields overall worse clinical outcomes and active ROM compared with RTSA performed for elective indications including CTA, massive irreparable RCTs, and osteoarthritis with deformity. Tuberosity healing may be a major contributing factor to the difference in clinical outcomes. In the setting of RTSA-F, patient and surgeon expectations may need to be tempered and appropriate measures undertaken to optimize tuberosity healing.