BACKGROUND: Mechanical complications affect the stability of implant restorations and are a key concern for clinicians, especially with the frequent introduction of new implant designs featuring various structures and materials. This study evaluated the effect of different prosthetic index structure types and implant materials on the stress distribution of implant restorations using both in silico and in vitro methods.
METHODS: Four finite element analysis (FEA) models of implant restorations were created, incorporating two prosthetic index structures (cross-fit (CF) and torc-fit (TF)) and two implant materials (titanium and titanium-zirconium). A static load was applied to each group. An in vitro study using digital image correlation (DIC) with a research scenario identical to that of the FEA was conducted for validation. The primary strain, sensitivity index, and equivalent von Mises stress were used to evaluate the outcomes.
RESULTS: Changing the implant material from titanium to titanium-zirconium did not significantly affect the stress distribution or maximum stress value of other components, except for the implant itself. In the CF group, implants with a lower elastic modulus increased the stress on the screw. The TF group showed better stress distribution on the abutment and a lower stress value on the screw. The TF group demonstrated similar sensitivity for all components. DIC analysis revealed significant differences between TF-TiZr and CF-Ti in terms of the maximum (P < 0.001) and minimum principal strains (P < 0.05) on the implants and the minimum principal strains on the investment materials in both groups (P < 0.001).
CONCLUSIONS: Changes in the implant material significantly affected the maximum stress of the implant. The TF group exhibited better structural integrity and reliability.

UNASSIGNED: This study aims to analyze the biomechanical characteristics of posterolateral plateau fractures fixed by a novel anatomical plate using finite element analysis.
UNASSIGNED: A three-dimensional digital model of the full length of right tibiofibula was obtained by CT scanning. A posterolateral tibial plateau fracture model was then created. The acquired fracture model was assembled with 4 groups of internal fixations: Group A, novel anatomical plate; Group B, straight buttress plate; Group C, oblique T-shaped locking plate; Group D, two lag screws. Axial loads of 500, 1,000 and 1,500 N perpendicular to the horizontal plane were used to simulate the stress on the lateral plateau of a 65 kg person standing, walking and fast running.
UNASSIGNED: Vertical displacements of the posterolateral fragments in each of the four groups gradually increased under loads from 500 N to 1,500 N. The maximum displacement of the fracture fragment in four groups were all located on the lateral side of the proximal part, and the displacement gradually decreased from the proximal part to the distal end. The maximum displacement values under the axial load of 1,500 N was in the following order: novel anatomical plate (1.2365 mm) < oblique T-shaped locking plate (1.314 mm) < two lag screws (1.3747 mm) < straight buttress plate (1.3932 mm). As the axial load increased, the stress value of the different internal fixation models gradually increased. The stress behavior of the same internal fixation model under different loads was similar. The maximum stress value under the axial load of 1,500 N was in the following order: novel anatomical plate (114.63 MPa) < oblique T-shaped locking plate (277.17 MPa) < two lag screws (236.75 MPa) < straight buttress plate (136.2 MPa).
UNASSIGNED: The patients with posterolateral plateau fractures fixed with a novel anatomical plate in standing, walking and fast running can achieve satisfactory biomechanical results, which lays the foundation for future applications. At the same time, clinical fracture types are often diverse and accompanied by damage to the soft tissue. Therefore, the ideal surgical approach and appropriate internal fixation must be selected based on the patient\'s injury condition.

UNASSIGNED: Bilateral combined fractures of the greater tuberosity with anterior internal shoulder dislocation are extremely rare, presenting challenges in treatment due to their uncommon occurrence and lack of standardized management protocols.
METHODS: We report the case of a 22-year-old patient who experienced bilateral anterior shoulder dislocations with associated fractures of the greater tuberosities following a seizure-induced fall. Clinical Discussion: The unique aspect of our case is the unusual mechanism of injury. Unlike typical convulsive seizures, which often result in bilateral posterior dislocations, our patient suffered bilateral anterior dislocations and fractures of the greater tuberosities. Therapeutic management of greater tuberosity fractures lacks a standardized approach, but surgical intervention is warranted if displacement exceeds 0.5 cm. Treatment options include open reduction and internal fixation (ORIF), percutaneous screw fixation, arthroscopic procedures with suture anchors for double-row repair, or a combination of arthroscopic techniques and screw fixation. ORIF with plate osteosynthesis may be recommended for comminuted fractures with large fragments. To assess functional outcomes, commonly used scoring systems include the UCLA Shoulder Score, ASES Score, and Constant-Murley Score.
CONCLUSIONS: Bilateral anterior shoulder dislocation associated with combined fractures of the greater tuberosity is an extremely rare occurrence. Given its anatomopathological significance and impact on functional recovery, careful and individualized management of greater tuberosity fractures is crucial, considering its role as a point of insertion for the rotator cuff tendons.

BACKGROUND: Avulsion fractures of the calcaneal tuberosity with significant displacement can cause soft tissue complications in the heel. However, a treatment strategy for calcaneal tuberosity fractures with poor heel-skin condition is yet to be established. Here, we report a case involving avulsion fracture of the calcaneal tuberosity presenting with superficial skin necrosis that was treated with a plate lacking the anterior component and screws inserted percutaneously.
METHODS: A 74-year-old woman presented with progressive right heel pain following an injury to her heel sustained approximately six weeks previously. She had experienced difficulty walking due to heel pain and superficial necrosis was observed on the posterior surface of the heel. Radiography and computed tomography revealed an avulsion fracture of the calcaneal tuberosity with superior displacement. Open reduction was performed using a lateral L-shaped incision. After inserting two cancellous screws percutaneously into the calcaneal tuberosity, we fixed a plate lacking the anterior component to the lateral surface of the calcaneus. The superficial necrosis healed gradually post-operatively. Bone union was confirmed using radiography six months post-operatively.
CONCLUSIONS: We developed a novel surgical procedure to treat avulsion fractures of the calcaneal tuberosity with poor skin condition. The combination of a plate lacking the anterior component and the percutaneous insertion of canulated cancellous screws can reduce the risk of post-operative soft tissue complications while maintaining fixation of the fractured fragment.
CONCLUSIONS: Our findings provide a novel surgical method for the treatment of avulsion fractures of the calcaneal tuberosity with soft tissue complications.

The controlled dynamization of fractures can promote natural fracture healing by callus formation, while overly rigid fixation can suppress healing. The advent of locked plating technology enabled new strategies for the controlled dynamization of fractures, such as far cortical locking (FCL) screws or active plates with elastically suspended screw holes. However, these strategies did not allow for the use of non-locking screws, which are typically used to reduce bone fragments to the plate. This study documents the first in vivo study on the healing of ovine tibia osteotomies stabilized with an advanced active plate (AAP). This AAP allowed plate application using any combination of locking and non-locking screws to support a wide range of plate application techniques. At week 9 post-surgery, tibiae were harvested and tested in torsion to failure to assess the healing strength. The five tibiae stabilized with an AAP regained 54% of their native strength and failed by spiral fracture through a screw hole, which did not involve the healed osteotomy. In comparison, tibiae stabilized with a standard locking plate recovered 17% of their strength and sustained failure through the osteotomy. These results further support the stimulatory effect of controlled motion on fracture healing. As such, the controlled dynamization of locked plating constructs may hold the potential to reduce healing complications and may shorten the time to return to function. Integrating controlled dynamization into fracture plates that support a standard fixation technique may facilitate the clinical adoption of dynamic plating.

Introduction: Jones fractures frequently fail to unite, and adequate fixation stability is crucial. This study aimed to elucidate the biomechanical stability of various intramedullary screw fixation constructs. Methods: Jones fracture model over the proximal 5th metatarsal of artificial bone was created in all specimens. Six groups were divided based on varied screw constructs with different screw lengths, either 30 or 40 mm, including cannulated screws-C30 and C40 groups, one high-resistance suture combined with intramedullary cannulated screws (F.E.R.I. technique)-CF30 and CF40 groups, and second-generation headless compression screws (SG-HCS) -HL30 and HL40 groups. Mechanical testing was conducted sequentially, and the maximal force (N) and stiffness (N/mm) of all constructs were recorded. Results: The maximal force (N) at 1.0 mm downward displacement in C30, C40, CF30, CF40, HL30, and HL40 groups were 0.56 ± 0.02, 0.49 ± 0.02, 0.65 ± 0.02, 0.49 ± 0.01, 0.68 ± 0.02, and 0.73 ± 0.02, respectively, and the stiffness (N/mm) in subgroups were 0.49 ± 0.01, 0.43 ± 0.01, 0.67 ± 0.01, 0.42 ± 0.01, 0.61 ± 0.01, and 0.58 ± 0.02, respectively. SG-HCS subgroups exhibited greater maximal force and stiffness than conventional cannulated screws. Screws of 30 mm in length demonstrated better stability than all 40 mm-length screws in each subgroup. In C30 fixation, the stiffness and maximum force endured increased by 1.16 and 1.12 times, respectively, compared with the C40 fixation method. There were no significant differences between CF30 and SG-HCS groups. Only the F.E.R.I technique combined with the 4.5 mm cannulated screw of 30 mm in length increased the biomechanical stability for Jones fractures. Discussion: These biomechanical findings help clinicians decide on better screw fixation options for greater stability in Jones fractures, especially when large-diameter screws are limited in use. However, this biomechanical testing of intramedullary screw fixation on Jones fracture model lacks clinical validation and no comparisons to extramedullary plate fixations. Moving forward, additional clinical and biomechanical research is necessary to validate our findings.

Akin osteotomy is commonly used to correct hallux valgus interphalangeus (HVI) deformity. The preferred implant for fixation remains an area of debate, often influenced by the surgeon\'s inclinations and expertise. This review compares the outcomes of contemporary fixation methods utilized in Akin osteotomy. PubMed served as the primary electronic database for the search. The interventions encompassed the use of screw(s), staple(s), and suture(s). The participants considered were adults aged 18 and above, undergoing Akin osteotomy either as a primary procedure or as an adjunct. Excluded were osteotomies performed via percutaneous or minimally invasive methods. Seven studies involving 590 feet were analysed, showcasing an impressive 99.8% overall union rate. The incidence of overall complications stood at 8.98%, with metal prominence notably higher in the screw fixation group (10.5%). All studies exhibited postoperative improvement in radiological angles. Screw, staple, and suture fixations demonstrated excellent union rates. While screws and staples offer robust osteotomy fixation, they pose risks of metal irritation and prominence. Suture fixation delivers comparable outcomes to the other two stabilization methods at a lower cost.

Posterior malleolus fractures (PMFs) (OTA 43B1.1) are frequently seen in combination with fractures of the fibula, medial malleolus, and distal tibia; they can rarely be seen in isolation. PMFs affect the alignment of the ankle mortise and the stability of syndesmosis. Techniques described for fixation of PMFs include open reduction internal fixation through a posterolateral or posteromedial approach or anterior-to-posterior screw fixation. For selected minimally displaced or nondisplaced fractures of the posterior malleolus, we developed a percutaneous technique through the Achilles tendon for the insertion of a posterior-to-anterior cannulated screw. The technique is described, and a clinical series is reviewed.

This case report documents the diagnosis and successful management of a substantial periapical lesion located in the lower left region of the jaw. The patient presented with clinical symptoms indicative of periapical pathology, and radiographic examination revealed an extensive radiolucent lesion. The chosen treatment approach involved endodontic intervention coupled with surgical decompression, leading to the resolution of the lesion and restoration of oral health. This case underscores the significance of an accurate diagnosis and a multidisciplinary treatment approach in addressing large periapical lesions.

Fracture healing in the aged is associated with a reduced healing capacity, which often results in delayed healing or non-union formation. Many factors may contribute to this deterioration of bone regeneration, including a reduced \'angiogenic trauma response\'. The phosphodiesterase-3 (PDE-3) inhibitor cilostazol has been shown to exert pro-angiogenic and pro-osteogenic effects in preclinical studies. Therefore, we herein analyzed in a stable closed femoral fracture model whether this compound also promotes fracture healing in aged mice. Forty-two aged CD-1 mice (age: 16-18 months) were daily treated with 30 mg/kg body weight cilostazol (n = 21) or vehicle (control, n = 21) by oral gavage. At 2 and 5 weeks after fracture, the femora were analyzed by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry, and Western blotting. These analyses revealed a significantly increased bending stiffness at 2 weeks (2.2 ± 0.4 vs. 4.3 ± 0.7 N/mm) and an enhanced bone formation at 5 weeks (4.4 ± 0.7 vs. 9.1 ± 0.7 mm3) in cilostazol-treated mice when compared to controls. This was associated with a higher number of newly formed CD31-positive microvessels (3.3 ± 0.9 vs. 5.5 ± 0.7 microvessels/HPF) as well as an elevated expression of phosphoinositide-3-kinase (PI3K) (3.6 ± 0.8 vs. 17.4 ± 5.5-pixel intensity × 104) and runt-related transcription factor (RUNX)2 (6.4 ± 1.2 vs. 18.2 ± 2.7-pixel intensity × 104) within the callus tissue. These findings indicate that cilostazol accelerates fracture healing in aged mice by stimulating angiogenesis and the expression of PI3K and RUNX2. Hence, cilostazol may represent a promising compound to promote bone regeneration in geriatric patients.