OBJECTIVE: To compare the biomechanical properties of personalized Y-shaped plates with horizontal plates, vertical plates, and traditional Y-shaped plates in the treatment of distal humeral intra-articular fractures through finite element analysis, and to evaluate their potential for clinical application. METHODS: The study selected a 38-year-old male volunteer and obtained a three-dimensional model of the humerus by scanning his upper limbs using a 64-slice spiral CT. Four types of fracture-internal fixation models were constructed using Mimics 19.0, Geomagic Wrap 2017, Creo 6.0, and other software: horizontal plates, vertical plates, traditional Y-shaped plate, and personalized Y-shaped plate. The models were then meshed using Hypermesh 14.0 software, and material properties and boundary conditions were defined in Abaqus 6.14 software. AnyBody 7.3 software was used to simulate elbow flexion and extension movements, calculate muscle strength, joint forces, and load torques, and compare the peak stress and maximum displacement of the four fixation methods at different motion angles (10°, 30°, 50°, 70°, 90°, 110°, 130°, 150°) during elbow flexion and extension. RESULTS: Under dynamic loading during elbow flexion and extension, the personalized Y-shaped plate exhibits significant biomechanical advantages. During elbow flexion, the peak internal fixation stress of the personalized Y-shaped plate was (28.8±0.9) MPa, which was significantly lower than that of the horizontal plates, vertical plates, and traditional Y-shaped plate ( P<0.05). During elbow extension, the peak internal fixation stress of the personalized Y-shaped plate was (18.1±1.6) MPa, which was lower than those of the other three models, with significant differences when compared with horizontal plates and vertical plates ( P<0.05). Regarding the peak humeral stress, the personalized Y-shaped plate model showed mean values of (10.9±0.8) and (13.1±1.4) MPa during elbow flexion and extension, respectively, which were significantly lower than those of the other three models ( P<0.05). Displacement analysis showed that the maximum displacement of the humerus with the personalized Y-shaped plate during elbow flexion was (2.03±0.08) mm, slightly higher than that of the horizontal plates, but significantly lower than that of the vertical plates, showing significant differences ( P<0.05). During elbow extension, the maximum displacement of the humerus with the personalized Y-shaped plate was (1.93±0.13) mm, which was lower than that of the other three models, with significant differences when compared with vertical plates and traditional Y-shaped plates ( P<0.05). Stress contour analysis showed that the stress of the personalized Y-shaped plate was primarily concentrated at the bifurcation of the Y-shaped structure. Displacement contour analysis showed that the personalized Y-shaped plate effectively controlled the displacement of the distal humerus during both flexion and extension, demonstrating excellent stability. CONCLUSION The personalized Y-shaped plate demonstrates excellent biomechanical performance in the treatment of distal humeral intra-articular fractures, with lower stress and displacement, providing more stable fixation effects.
Humans ; Male ; Adult ; Healthy Volunteers ; Finite Element Analysis ; Tomography, Spiral Computed ; Models, Anatomic ; Biomechanical Phenomena ; Humeral Fractures, Distal/surgery* ; Fracture Fixation, Internal/instrumentation* ; Bone Plates ; Computer Simulation ; Precision Medicine/methods* ; Elbow Joint/surgery* ; Elbow/surgery* ; Humerus/surgery* ; Torque ; Stress, Mechanical ; Intra-Articular Fractures/surgery* ; Prosthesis Design/methods* ; Imaging, Three-Dimensional ; Range of Motion, Articular

BACKGROUND: The purpose of this study was to investigate the incidence of acromial fracture after reverse total shoulder arthroplasty (RTSA) and clinical and radiological outcomes of treatment of the fracture. METHODS: A systematic review was performed to identify studies that reported the results of treatment of acromial fractures after RTSA. A literature search was conducted by two investigators using four databases (PubMed, Embase, Cochrane, and Ovid Medline). RESULTS: Fifteen studies (2,857 shoulders) satisfied our inclusion criteria. The incidence of acromial fracture after RTSA was 4.0% (114 / 2,857). The mean age of the patients at the time of fracture was 72.9 years (range, 51 to 91 years). The mean time from RTSA to diagnosis of acromial fracture was 9.4 months (range, 1 to 94 months). One hundred shoulders (87.7%) were treated conservatively and 14 shoulders (12.3%) were treated surgically. The mean follow-up period after acromial fracture was 33.8 months. The overall union rate was 50.0% (43.8% for conservative treatment and 87.5% for operative treatment). The fracture incidence was significantly different among the medial glenoid and medial humerus prosthesis design (8.4%), the lateral glenoid and medial humerus design (4.0%), and the medial glenoid and lateral humerus design (2.8%). The mean values at final follow-up were as follows: visual analog scale score, 2.2; American Shoulder and Elbow Surgeons score, 59.1; Constant score, 59.7; and Simple Shoulder Test, 5.8. The mean forward flexion, abduction, and external rotation were 102.3°, 92.3°, and 25.8°, respectively. CONCLUSIONS: Acromial fractures after RTSA are a complication neither uncommon nor negligible. In the absence of studies with high-level evidence, there is a controversy on the outcomes after treatment. Further well-designed prospective randomized controlled studies with a long-term follow-up should be performed to ascertain the diagnosis, treatment, and prognosis of acromial fractures after RTSA.
Acromion ; Arthroplasty ; Diagnosis ; Elbow ; Follow-Up Studies ; Humans ; Humerus ; Incidence ; Prognosis ; Prospective Studies ; Prosthesis Design ; Research Personnel ; Shoulder ; Surgeons ; Visual Analog Scale

Total elbow arthroplasty is a common surgical procedure used in the management of advanced rheumatoid arthritis, posttraumatic arthritis, osteoarthritis, and unfixable fracture in elderly patients. Total elbow prostheses have evolved over the years and now include the linked, unlinked, and convertible types. However, long-term complications, including infection, aseptic loosening, instability, and periprosthetic fracture, remain a challenge. Here, we introduce each type of implant and evaluate clinical outcomes and complications by reviewing the previous literature.
Aged ; Arthritis ; Arthritis, Rheumatoid ; Arthroplasty ; Elbow Prosthesis ; Elbow ; Humans ; Osteoarthritis ; Periprosthetic Fractures ; Reoperation ; Treatment Outcome

PURPOSE: Understanding elbow biomechanics is necessary to understand the pathophysiologic mechanism of elbow injury and to provide a scientific basis for clinical practice. This article provides a summary of key concepts that are relevant to understanding common elbow injuries and their management. MATERIALS AND METHODS: The biomechanics of the elbow joint can be divided into kinematics, stability and force transmission through the elbow joint. Active and passive stabilizers include bony articular geometry; soft tissues provide joint stability, compression force and motion. RESULTS AND CONCLUSION: Knowledge of elbow biomechanics will help (i) advance surgical procedures and trauma management, (ii) develop new elbow prostheses and (iii) stimulate future research.
Biomechanics ; Elbow ; Elbow Joint ; Elbow Prosthesis ; Joints

OBJECTIVETo retrospectively review the results of Coonrad-Morrey semi-constrained total elbow arthroplasty (TEA) for the treatment of different elbow disorders.

METHODSBetween December 2003 and April 2008, 30 patients with different kinds of elbow disorders including elbow fracture, non-healing elbow fracture, rheumatoid arthritis and osteoarthritis were treated with TEA using the semi-constrained Coonrad-Morrey elbow replacement prostheses. One patient had bilateral total elbow replacements. There were 22 females and 8 males, with a mean age of 66 years (47 to 78).

RESULTSTwenty patients (21 elbows) were available for review. The average length of follow-up was 35 months (from 12 to 52 months). The mean Mayo elbow performance score was 84 points. Excellent results were achieved in 6 elbows (28%), 11 elbows had good outcome (52%), 2 elbows had improvement (10%), while the other 2 elbows had no improvement (10%). The 2 elbows with distal humeral fractures, had no pain after treatment but developed heterotopic ossification, which caused stiffness and lower the Mayo elbow performance score. One delayed healing of the wound, one patient experienced temporary radial nerve hypesthesia and one elbow showed transparent region around the implant without radiological sign of loosening in the implanted prostheses.

CONCLUSIONSThis study reveals good to excellent outcome with the use of semi-constrained TEA for the treatment of rheumatoid arthritis, elbow fracture, osteoarthritis and non-healing elbow fractures in elder patients. The non-healing elbow fractures in elder patients would accompany with severe osteoporosis and comminuted fracture, which would affect the result of open reduction internal fixation. So TEA may be one optimal treatment for these patients.

Aged ; Arthritis, Rheumatoid ; surgery ; Arthroplasty, Replacement ; instrumentation ; methods ; Elbow Joint ; surgery ; Female ; Follow-Up Studies ; Humans ; Humeral Fractures ; surgery ; Joint Prosthesis ; Male ; Middle Aged ; Osteoarthritis ; surgery ; Retrospective Studies ; Treatment Outcome

No abstract available.
Arthritis, Rheumatoid* ; Elbow Prosthesis* ; Elbow*