Plate Fracture Research Articles

An experimental investigation on the ice-breaking phenomenon induced by the spark-generated bubble near a vertical plate

The present work experimentally studied the coupled interaction between the fracture of an ice plate floating on the water surface, induced by the pulsation of a high-pressure bubble, and the associated deformation of a vertically submerged aluminum plate. The dynamic behaviors of bubbles and fractured ice were concurrently recorded using two high-speed cameras, and the plastic deformation of the aluminum plate was measured by an ultra-depth three-dimensional microscope. The results indicated that the jet direction of the collapsed bubble is heavily influenced by the position to generate the bubble due to the competing Bjerknes forces caused by various boundaries. There is also a significant discrepancy in the phenomena of bubble collapse near thin vs thick ice plates, attributed to the sudden alteration in boundary conditions caused by ice fracturing. Three distinct ice-breaking mechanisms, namely, the hogging moment, jet impact, and the secondary shock wave, were identified based on the types of loads, leading to the initial ice fractures. In general, it was observed that the efficiency of ice breaking improved with a decrease in the bubble–ice distance (γf) and an increase in the bubble–plate distance (γm). It was found that the contacting jet from an upwardly collapsed bubble is the most effective in breaking the thickest ice plates for γm>1.9. While the shock wave from a bubble collapsing near solid wall corners could fracture thick ice plates, the aluminum plate risked damage from jet impacts when γm was less than 0.6.

Dorsal wrist plating for the management of intra-articular distal radius fractures.

The aim of the study was to evaluate the results of Dorsal Wrist Plating in intra-articular distal radius fractures with a dorsal displacement. In this prospective study, a single surgeon treated 20 patients with a (partially) intra-articular distal radius fracture with a dorsal rim avulsion or a dorsal Barton's type fragment. They all underwent an open reduction and internal fixation by Dorsal Wrist Plating. A total of 17 patients had a follow-up period of at least 12 months (mean follow- up of 17 months) and these patients were included in the study. Both functional and radiological outcome parameters were measured. The total range of motion was 92 % of the contralateral side. The mean grip strength and key pinch were 24.6 kg and 6.9kg respectively compared to 29.5 kg and 7.4 kg on the non-operated side. The average Mayo Wrist Score was 89.7 (range 80-100) and the mean Disability of the Arm, Shoulder and Hand score was 4.5 (range 0-9.2). An articular step-off was only noted in 2 patients (1 and 2 mm respectively). Radial inclination was restored in all patients. Palmar tilt was anatomically restored in five patients. In all other patients, the palmar tilt was acceptably restored. There was no significant radial shortening in any of the patients. No infections, no tendon ruptures, no Complex Regional Pain Syndrome, or union problems were observed. Dorsal wrist plating seems to be a safe and reliable procedure in the treatment of intra-articular distal radius fractures with dorsal displacement.

Does Anterior Plating of Pelvic Ring Fractures Increase Infection Risk in Patients With Bladder or Urethral Injuries?

Evaluate the effect of anterior fixation on infection in patients with operative pelvic fractures and bladder or urethral injuries. Retrospective. Eight centers. Adult patients with closed pelvic fractures with associated bladder or urethral injuries treated with anterior plating (AP), intramedullary screw (IS), or no anterior internal fixation (NAIF, including external fixation or no fixation). Deep infection. There were 81 extraperitoneal injuries and 57 urethral injuries. There was no difference in infection between fixation groups across all urologic injuries (AP: 10.8%, IS: 0%, NAIF: 4.9%, P = 0.41). There was a higher rate of infection in the urethral injury group compared with extraperitoneal injuries (14.0% vs. 2.5%, P = 0.016). Among extraperitoneal injuries, specifically, there was no difference in deep infection related to fixation (AP: 2.6%, IS 0%, NAIF: 2.9%, P = 0.99). Among urethral injuries, there was no statistical difference in deep infection related to fixation (AP: 23.1%, IS: 0%, NAIF: 7.4%, P = 0.21). There was a higher rate of suprapubic catheter (SPC) use in urethral injuries compared with extraperitoneal injuries (57.9% vs. 4.9%, P < 0.0001). In the urethral injury group, SPC use did not have a statistically significant difference in infection rate (SPC: 18.2% vs. No SPC: 8.3%, P = 0.45). Early removal of the SPC before or during the definitive orthopaedic intervention did not significantly affect infection rate (early: 0% vs. delayed: 25.0%, P = 0.16). Surgeons should approach operative pelvic fractures with associated urologic injuries with caution given the high risk of infection. Further work must be done to elucidate the effect of anterior implants and SPC use and duration. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lower Limb Malrotation following Minimally Invasive Plating in Distal Tibia Fractures.

Minimally invasive percutaneousosteosynthesis (MIPO) plating techniques havedemonstrated good outcomes in the treatment of distal tibia fractures. Early arthritis and functional impairment mayoccur if length and rotation are not restored. This study aims to determine the incidence and severity of tibia malrotation following MIPO plating of isolated unilateral distal tibia fractures, defined as torsional difference of greater than 10° as compared to the contralateral limb and whether the degree of malrotation affects functional outcomes scores. This was a level 2 prospective cohort study. All patients with fractures of the distal tibia who underwent surgical fixation with the exclusion ofpatients with polytrauma, neurovascular injuries or pre-existing disabilities were recruited. Patients underwent MIPO plating followed by a post-operative ComputedTomography (CT) scan of bilateral lower limbs. AOFAS ankle-hindfoot score was recorded at six months and one year follow-up. A total of 24 patients (28 to 83 years old) were recruited. Nineteen patients obtained CT scans. Nine of the 19 patients (47.3%) had tibia malrotation. The mean tibia malrotation angle was 10.3° (0° - 45°). The average AOFAS scores was 82.4 and 84.3 at 6 months and 1 year follow-up. Degree of CT malrotation was not significantly associated with AOFAS scores at 6 month (spearman rho -0.386) and 1 year (spearman rho -0.343). Tibia malrotation following MIPO plating of distal tibia fractures is common, with an incidence of 47.3% and an average malrotation angle of 10.3°. The degree of malrotation does not appear to have significant mid-term functional impact on the patient.

A single-centre retrospective 10-year experience of the rhombic 3D condylar fracture plate for open reduction and internal fixation of condylar neck and base fractures

Fractures of the mandibular condyle account for a significant proportion of mandibular fractures. The specific functional loads require particular specifications for the implant design used for open reduction and internal fixation of such fractures. The clinical and radiographic outcomes in patients treated using a single rhombic 3D condylar fracture plate for open reduction and internal fixation at a single institution, and who fulfilled the inclusion and exclusion criteria, are presented.The primary outcome variables were: occlusion, maximum interincisal distance and mandibular excursion at 1, 3, and 6 months postoperatively, and radiographic measurements for mandibular height and gonion angle.In total, 263 patients were included, of whom 173 (65.8%) were male and 90 (34.2%) female. The mean age was 40.4 ± 18.9 years. There was satisfactory occlusion in 98.9% of patients at the 6-month follow-up, and a significant improvement in all parameters for mandibular excursion (p < 0.001), with a reduced ramus height and an increase in the gonion angle on the fractured side.Excellent clinical and radiographic results were achieved using the rhombic-shaped implant, deeming it appropriate for the osteosynthesis of mandibular condyle fractures.

Comparison of Intramedullary Screw Fixation, Plating, and K-Wires for Metacarpal Fracture Fixation: A Meta-Analysis.

Metacarpal fractures are common injuries with multiple options for fixation. Our purpose was to compare outcomes in metacarpal fractures treated with intramedullary screw fixation (IMF), Kirschner wires (K-wires), or plating. A systematic literature review using the MEDLINE database was performed for studies investigating metacarpal fractures treated with IMF, plating, or K-wires. We identified 34 studies (9 IMF, 8 plating, 17 K-wires). A meta-analysis using both mixed and fixed effects models was performed. Outcome measures included mean Disabilities of the Arm, Shoulder, and Hand (DASH) scores, total active motion (TAM), grip strength, time to radiographic healing, and rates of infection and reoperation. Patients with IMF had significantly lower DASH scores (0.6 [95% confidence interval [CI], 0.2-1.0]) compared with K-wires (7.4 [4.8-9.9]) and plating (9.8 [5.3-14.3]). Intramedullary screw fixation also had significantly lower rates of reoperation (4%, [2%-7%]), compared with K-wires (11% [7%-16%]) and plating (11% [0.07-0.17]). Grip strength was significantly higher in IMF (104.4% [97.0-111.8]) compared with K-wires (88.5%, [88.3-88.7]) and plating (90.3%, [85.4-95.2]). Mean odds ratio time was similar between IMF (21.0 minutes [10.4-31.6]) and K-wires (20.8 minutes [14.0-27.6]), but both were shorter compared with plating (52.6 minutes [33.1-72.1]). There were no statistically significant differences in time to radiographic healing, TAM, or rates of reoperation or infection. This meta-analysis compared the outcomes of metacarpal fixation with IMF, K-wires, or plating. Intramedullary screw fixation provided statistically significant lower DASH scores, higher grip strength, and lower rates of reoperation, suggesting that it is a comparable method of fixation to K-wires and plating for metacarpal fractures.

Combined home and clinic-based therapy versus home-based exercise programme after distal radial fracture: a randomized controlled study.

We investigated outcomes of clinic-based hand therapy combined with a home-based exercise programme after anterior plating for distal radial fractures. A total of 102 patients were randomly assigned to one of three groups: a home-based exercise programme alone; a home-based exercise programme combined with four hand therapy sessions in the clinic; and a home-based exercise programme with seven sessions in the clinic. Mean Patient-Rated Wrist Evaluation scores at 6 weeks were significantly better for the group of patients with seven sessions in the clinic than in those with only home exercises (12 vs. 30), but the difference was no longer significant at 12 weeks. Grip strength was significantly better at 6 and 12 weeks. Combined home- and clinic-based hand therapy may facilitate an earlier return of function after anterior plating for distal radius fractures.Level of evidence: II.

Evaluation of the Stability of Internal Fixation Constructs in a Low Distal Tibia Extra-articular Cadaveric Fracture Model: A Comparative Biomechanical Study.

Introduction Despite the recent advances in implant design, the choice of an internal fixation modality for extra-articular distal tibia fractures remains controversial, and there is sparse literature comparing the stability of intramedullary nails and locked plates for such fractures. Hence, we conducted a biomechanical study on an AO type 43A3 tibia fracturecadaveric model stabilized by four different constructs, viz., intramedullary (IM) interlocking nail, anteromedial plate, anterolateral plate, and posterior plate.An AO type 43A3 fracture is defined as an extra-articular fracture of the distal tibia with metaphyseal comminution. Methods A biomechanical comparative study on formalin-preserved human cadaveric tibiae was undertaken; a total of four groups were tested, with eight bones in each group. Out of the 32 cadaveric tibiae, 19 bones belonged to male cadavers, and 13 bones belonged to female cadavers. All bones were dissected from age-appropriate cadavers and fixed with an implant, followed by the creation of a 1 cm osteotomy to simulate an AO type 43A3 fracture. All fixation constructs were subjected to three-point bending tests in the anteroposterior (AP) and mediolateral (ML) planes. Three parameters, viz., bending stiffness, peak fracture gap angle, and neutral zone, were evaluated on the load-displacement curves. Afixation construct was deemed biomechanically stable if it had a highbending stiffness, a low neutral zone (inherent toggle in the construct by its weight), and a low peak fracture gap angle. Results Out of the four implants tested, locked IM nails exhibited the maximum biomechanical stability in terms of higher bending stiffness, smaller peak fracture gap angle, and smaller neutral zones. The IM nail exhibited the highest bending stiffness in the AP plane, and the anterolateral plate had the lowest bending stiffness, and the difference was statistically significant (p= 0.032).In the AP plane, the anterolateral plate exhibited a bending stiffness of 1.51 ± 0.69 Nm/degree, whereas the intramedullary nail exhibited a bending stiffness of 2.34 ± 0.81 Nm/degree, and the posterior locked plate had a bending stiffness of 1.57 ± 0.44 Nm/degree. In the ML plane, the anterolateral plate exhibited the highest neutral zone as compared to the intramedullary nail, which had the lowest neutral zone, and the difference was statistically significant (p = 0.019). The intramedullary nail exhibited the lowest neutral zone of 0.46 ± 0.31 degrees, whereas the posterior locked plate exhibited a neutral zone of 0.78 ± 0.43 degrees in the ML plane. The anterolateral plate exhibited a neutral zone of 1.43 ± 1.00 (expressed as mean ± SD) degrees in the mediolateral plane. Conclusion Our biomechanical study supports the recommendations of using a locked intramedullary nail for AO type 43A3 fractures. We concluded that the anterolateral plate construct exhibited the least biomechanical stability, in terms of lower AP bending stiffness and higher neutral zone. If the surgeon must choose a locked plating technique for any reason, the anterolateral locking plate should be avoided. If plating is at all required, we can recommend both anteromedial and posterior locked plating as biomechanically sound options.

Weak Points of Double-Plate Stabilization Used in the Treatment of Distal Humerus Fracture through Finite Element Analysis.

Multi-comminuted, intra-articular fractures of the distal humerus still pose a challenge to modern orthopedics due to unsatisfactory treatment results and a high percentage (over 50%) of postoperative complications. When surgical treatment is chosen, such fractures are fixed using two plates with locking screws, which can be used in three spatial configurations: either parallel or one of two perpendicular variants (posterolateral and posteromedial). The evaluation of the fracture healing conditions for these plate configurations is unambiguous. The contradictions between the conclusions of biomechanical studies and clinical observations were the motivation to undertake a more in-depth biomechanical analysis aiming to indicate the weak points of two-plate fracture stabilization. Research was conducted using the finite element method based on an experimentally validated model. Three variants of distal humerus fracture (Y, λ, and H) were fixed using three different plate configurations (parallel, posterolateral, and posteromedial), and they were analyzed under six loading conditions, covering the whole range of flexion in the elbow joint (0-145°). A joint reaction force equal to 150 N was assumed, which corresponds with holding a weight of 1 kg in the hand. The biomechanical conditions of bone union were assessed based on the interfragmentary movement (IFM) and using criteria formulated by Steiner et al. Results: The IFMs were established for particular regions of all of the analyzed types of fracture, with distinction to the normal and tangential components. In general, the tangential component of IFM was greater than normal. A strong influence of the elbow joint's angular position on the IFM was observed, with excessive values occurring for flexion angles greater than 90°. In most cases, the smallest IFM values were obtained for the parallel plaiting, while the greatest values were obtained for the posteromedial plating. Based on IFM values, fracture healing conditions in particular cases (fracture type, plate configuration, loading condition, and fracture gap localization) were classified into one of four groups: optimal bone union (OPT), probable union (PU), probable non-union (PNU), and non-union (NU). No plating configuration is able to ensure distal humerus fracture union when the full elbow flexion is allowed while holding a weight of 1 kg in the hand. However, flexion in the range of 0-90° with such loadings is acceptable when using parallel plating, which is a positive finding in the context of the early rehabilitation process. In general, parallel plating ensures better conditions for fracture healing than perpendicular plate configurations, especially the posteromedial version.

Angle-Adjustable Dynamic Hip Screw Plate for Unstable Trochanteric Fractures in Middle-Aged Patients: Mid-Term Outcomes and Return to Sport.

There are conflicting results in the literature regarding the superiority of proximal femoral nails over dynamic hip screw (DHS) plates. The primary aim of this study is to evaluate mid-term post-injury patient-reported outcome measures (PROMs) and return to sport (RTS) in middle-aged patients treated with the DHS plate for unstable trochanteric fractures. Fifty-seven middle-aged patients (35-64 years) treated for proximal femoral fractures of type 31-A2 and 31-A3 according to the AO/OTA classification with the DMS Dynamic Martin Screw (KLS Martin Group, Jacksonville, FL, USA) between January 2017 and December 2019 were enrolled. Forty-nine patients were included in this retrospective study, and the average age was 54.1 years (SD 8.4). The average follow-up duration at final follow-up was 60.5 months (SD 8.6). Post-operative complications included only one case of aseptic loosening of the implant, with a complication rate of 2%. There were no infections, peri-implant fractures, or other complications reported. Two out of the forty-nine patients (4.1%) required treatment with a total hip arthroplasty due to post-traumatic arthritis. The Harris Hip Score at final follow-up was 77.1 (SD 20.1), and the Western Ontario and McMaster Universities Osteoarthritis Index was 21.6 (SD 13.7). The overall rate of RTS was 57.7%. Treatment with DHS for unstable trochanteric fractures is a safe option in middle-aged patients, ensuring a good functional recovery.

A Retrospective Study on Pelvic Fractures in Cats and Dogs (2020-2022)

Pelvic fractures occur in many traumas in cats and dogs. In this study, it was aimed to evaluate the treatment (conservative and operative) and its results together in cats and dogs diagnosed with pelvic fracture. The study material consisted of 223 pelvic fractures (15 acetabulum, 40 ischi, 68 ilium, 38 pubis and 62 sacroiliac separation) detected in 27 dogs and 75 cats of different ages, breeds and genders between 2020-2022. Pelvic fracture was diagnosed with clinical and radiological examination. It was treated conservatively and operatively (using iliosacral screw, iliosacral pin, locking plate, cerclage, acetabular C plate). It was observed that cases with pelvic fractures were mostly caused by falling from a height in cats and traffic accidents in dogs. It was also observed that there could be a single fracture in the pelvis as well as multiple fractures. A total of 73 cases were operated. In 55 of the fractures, iliosacral screw, 1 iliosacral pin, 45 locked plate, 9 cerclage application, 10 acetabular C plate and 1 excision arthroplasty were applied. Conservative treatment was applied to 29 cases. No complications were observed in the controls performed in the operated patients. It was concluded that good results were obtained in stabilization with screws in cases of sacroiliac separation, and the use of locking plates in ilium fractures and the use of acetebular C plate in acetabulum fractures could lead to a more comfortable and comfortable postoperative period.

Optimal Plate Choice for High-Neck Mandibular Condyle Fracture: A Mechanistic Analysis of 16 Options

(1) Background: Mandibular fractures are common, with the condylar process being a frequent site of injury, accounting for 25–45% of cases. This research aims to assess the mechanical suitability of various plates for high-neck condyle fractures. (2) Methods: Polyurethane models mimicking high-neck condyle fractures were utilized in this study. Sixteen distinct plate designs, constructed from titanium sheets, were tested. The figures underwent force assessments on a durability testing apparatus, and the relationship between used force and fracture movement was documented. (3) Results: For high-neck breaking, the two straight plates emerged as the most effective, aligning with established osteosynthesis standards. The second-best plate exhibited nearly half the strength of the gold standard. (4) Conclusions: In response to the aim of this study, considering the mechanical aspects, the double plain plate stands out as the optimal choice for osteosynthesis in cases of high-neck fractures of the mandibular condylar process. In addition, the authors propose the Mechanical Excellence Factor (MEF) as a superior metric for appraising a plate’s mechanical force, surpassing the conventional Plate Design Factor (PDF).

Helical PHILOS plating in shaft humeral fractures with proximal extension: a safe choice using an anterior approach.

Helical plating for humeral shaft fractures has gained popularity in recent years as it avoids iatrogenic nerve damage. A total of 16 patients with humeral shaft fracture involving the metaphyseal proximal part were treated between Dicembrer 2016 and January 2023. Complications such as pseudarthrosis, infections and nerve lesions were investigated during the postoperative period. Functional outcome was quantified using the Italian version of the DASH 30 quality of life assessment item. Healing of the fracture was achie-ved at the last follow-up with good clinical recovery and no pain. The self-contoured Philos-Helix plate for humeral shaft fractures with proximal extension in combination with an anterior window approach is a safe procedure with good functional results at a follow-up of at least one year.

Risk of reverse golf club deformity with medial plating of distal femur fracture.

This study described a deformity induced by medial plating of supracondylar distal femur fractures using plates that are precontoured for other anatomic locations. OTA/AO 33A fractures were created in 12 sawbone femurs and fixed with either a proximal humerus locking plate (PH), an ipsilateral lateral tibial plateau plate (LTP), or an ipsilateral medial distal tibial plate (MDT). A motion capture system measured changes in length and rotation of the distal femur as the plate was applied. Each plate underwent four trials and the mean and standard deviation (SD) for each measurement was reported. An analysis of variance with post hoc Tukey test compared malreduction measures between plate types. All plates consistently created a varus deformity. There was lateral lengthening with a compensatory medial shortening and an increase in the lateral distal femoral angle. The distal fracture fragment was laterally translated, and internally rotated. The PH plate had significantly greater lateral length (27.39mm SD 4.78, p = 0.007), shorter medial length (13.57mm SD 4.99, p = 0.028), greater lateral translation (28.82mm SD 5.70, p = 0.010) and greater widening of the lateral distal femoral angle (28.54° SD 4.98, p < 0.001) than the LTP and MDT plates. The MDT plate had significantly greater angulation anteriorly (8.40° SD 1.07, p < 0.001) and laterally (7.63° SD 3.10, p = 0.002) than the PH and LTP plates. There was no significant difference between plates in internal rotation (PH: 3.07° SD 2.79; LTP: 2.05° SD 1.05; MDT 3.81° SD 3.56; p = 0.659). When dual plating supracondylar distal femur fractures, poor plate positioning and a mismatch between plate contour and the slope of the medial distal femur can lead to varus angulation, internal rotation, and lateral translation or a "reverse golf club deformity". After comparing three types of precontoured plates, the authors recommend initial evaluation of the ipsilateral proximal tibial plate when placing a plate along the medial distal femur. IV.

Outcome of fracture shaft of humerus fixed with dynamic compression plate in B. P. Koirala Institute of Health Sciences, Dharan, Nepal

Introduction: Open reduction and internal fixation with dynamic compression plate (DCP) is necessary for fracture shaft of humerus (SoH) whose closed reduction is not acceptable or cannot be retained in slab or cast.&#x0D; Objectives: Aim of the study was to evaluate outcome of fracture SoH fixed with DCP.&#x0D; Methodology: Patients with fracture SoH fixed with DCP in BPKIHS in 2015-16 were prospectively studied for one year for perioperative issues and functional outcome using DASH score.&#x0D; Results: There were 87 patients of fracture SoH fixed with DCP. Among 87 patients, 65.5% were male and 34.5% were female. The mean age was 36.4 years. The most common mode of injury was road traffic accident followed by fall from height, work place injury. The average operating time was 71 minutes with standard deviation 15.6. The mean blood loss was 205ml ± 45.60. Post-operative hospital mean stay was 4.5 days. There was post-operative radial nerve palsy in 4.6%. Only 69 patients can be followed up for one year for evaluation. Radial nerve palsy recovered fully in those with post-operative palsy. Disability of shoulder arm and hand (DASH) score was 82.50±9.6 after one year of surgery. Fracture was not united in 3(4.3%) patients out of 69 patients who reported for follow up at one year of injury and needed bone grafting and secondary intervention. This shows satisfactory functional outcome in fracture SoH fixed with DCP.&#x0D; Conclusion: Dynamic compression plating for SoH fracture has satisfactory outcome.

The application of inverted lateral clavicle locking compression plate for medial clavicle fractures: biomechanical study and clinical implementation.

There has been no absolute consensus on the optimal implant for fixation of medial clavicle fracture. The purpose of the present study was to test the biomechanical efficacy of inverted lateral clavicle locking compression plate (LCP-LC) in fixation of this specific fracture location by finite element analysis. Transverse and comminuted medial clavicle fracture simulated models stabilized by three different devices including inverted LCP-LC, superior clavicle LCP (LCP-SC), and dual reconstruction (LCP-RP) with LCP-SC were investigated biomechanical performance under three loading conditions, i.e., axial compression, inferior bending, and axial torsion. EQV stress exhibited on implant and elastic strain at fracture site under inferior bending was greater than other loading cases. LCP-SC construct represented the greatest EQV stress and elastic strain. The inverted LCP-LC construct demonstrated lower EQV stress than the LCP-SC construct and was comparable to dual plating. Under axial compression and axial torsion, elastic strain produced from the inverted LCP-LC construct was comparable to dual plating, but greater than dual plating when subjected to inferior bending. By the results of FE analysis, inverted LCP-LC could be a potential application for fixation of clavicle fracture with short medial fragment.

Dynamic Compression Plating Versus Antegrade Intramedullary Nailing for the Treatment of OTA/AO 12-A Fractures: A Retrospective Cohort Study.

Fractures of the humerus diaphysis are common and often result from motor vehicle accidents (MVAs). Treatment methods range from nonoperative approaches to various operative techniques, including antegrade intramedullary nailing (AIMN) and dynamic compression plate (DCP) fixation. This study aimed to compare the cost effectiveness and outcomes of plating and nailing for humerus diaphyseal fractures. A retrospective cohort study involving 59 cases of humerus diaphyseal OTA/AO 12-A fractures was conducted at King Saud Medical City (KSMC), a level I trauma center located in the center region in Riyadh, Saudi Arabia. Patients treated with AIMN, anterolateral plating, or posterior plating were included. Data on demographics, clinical parameters, radiographic healing, and costs were collected and analyzed. The average surgical duration was shorter in the AIMN group compared to the anterolateral and posterior plating groups but with no statistical significance (P > 0.05). The average length of stay (LOS) was shorter, and the change in hemoglobin levels was lower in the AIMN group when compared to other groups but without a statistically significant difference (P > 0.05). The average cost of AIMN was significantly higher than that of anterolateral and posterior plating groups (P < 0.0001). While both nailing and plating procedures are options for treating OTA/AO 12-A fractures, AIMN carries a higher overall procedural cost. The practice of drain placement in our study population is likely the cause of the increased LOS in the plating groups. Relative additional analgesic requirements were associated with AIMN. Surgeons should consider meticulous hemostasis to avoid drain placement, which can decrease LOS, thus possibly decreasing unnecessary treatment costs of humerus shaft fractures.

ANALYSIS OF HARDWARE REMOVAL IN MAXILLOFACIAL TRAUMA: A RETROSPECTIVE STUDY IN A MILITARY HOSPITAL IN SANA'A, YEMEN

Background and objective: Dental trauma is a significant problem for total dental health in terms of expenses, frequency, and age (young patients). Collaboration between various professionals, including oral surgeons, maxillofacial surgeons, dentists, orthodontists, and periodontists, frequently results in the treatment process. Surgical treatment may entail placing plates for fractures and shattered bones for long or permanent periods, and may require their removal for many reasons. Therefore, this study sought to ascertain the reasons for plate removal in individuals referred to the Department of Oral and Maxillofacial Surgery at Military Hospital in Sana'a, Yemen during a period of 3 years. Method: The study included 57 Yemeni patients who visited the Department of Oral and Maxillofacial Surgery at the Military Hospital in Sana’a during the period 2021-2023. Cases of hardware removal were extracted from the medical records to include sex, age, medical history, accident history, type of fracture, primary complaint, period from the date of the first operation, approach to the operation, tooth in the fracture line, and extracted tooth. Results: Gunshot injuries (40.4%) and explosive injuries (31.6%) were the most common causes of maxillofacial fractures. Mandibular fractures (68.4%) were the most frequent, followed by orbital and zygomatic fractures (12.3% each). The main reason for hardware removal was infections (29.8%), followed by patient preference (22.8%) and visible exposed hardware (15.8%). Mini-plates (68.4%) were the most commonly removed hardware, and the extra-oral approach (56.1%) was the most frequently used for removal. There was a significant association between orbital fractures and the incidence of positive discharge, as well as between reconstructive plates and the incidence of positive discharge. Longer plate usage, exceeding 24 months, increased the probability of positive discharge. Tooth involvement and extraction were minimal. Conclusion: Gunshot and explosive injuries were the main causes of maxillofacial fractures, while infections, patient preferences, visible exposed devices, and pain and discomfort were the main reasons for removal of devices. Mandibular fractures were the most common and orbital fractures carry a higher risk of infection, while small plates have shown lower rates of infection. Prolonged panel use beyond 24 months increased the probability of positive discharge. Peer Review History: Received: 25 October 2023; Revised: 18 November; Accepted: 24 December, Available online: 15 January 2024 Academic Editor: Dr. Gehan Fawzy Abdel Raoof Kandeel, Pharmacognosy Department, National Research Centre, Dokki, 12622, Giza, Egypt, gehankandeel9@yahoo.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com Dr. Hasniza Zaman Huri, University of Malaya Medical Centre, Kuala Lumpur, hasnizazh@ummc.edu.my

Damage mechanisms of spline teeth of friction plates under non-uniform impact

The fatigue fracture failure of friction plates seriously affects the safety of high-power density transmission systems due to the non-uniform impact with the inner hub. However, the crack initiation inducement and underlying damage mechanisms are still confused so far, which has critical significance for improving the service life. To address this problem, the matrix metallographic structure of friction plates was observed by Scanning Electron Microscope (SEM), which excludes internal defects within the organization. Then, an impact dynamic model was established to investigate the collision laws between spline teeth and the inner hub. The effect of the inner hub’s speed fluctuations on the impact force and acceleration was analyzed, and an analytical relationship between tooth root stress, impact force, and gear parameters was established. A large module simulation prototype test rig was designed based on the proposed equivalent model to verify the impact dynamic model. Results show that the majority of collisions between spline teeth and the inner hub are “catch-up collisions”, which well explains the non-uniform impact phenomenon. The “frontal collisions” will only occur when the speed of the inner hub is lower than that of the friction plate. The higher cumulative frequency of tensile stress on the pull side of spline teeth roots by “catch-up collisions” reveals the underlying mechanism for the differential extent of cracks’ damage. The minimum bending stress of the teeth root is 125.5 MPa at a pressure angle of 32°, which shows a linear increase with tooth clearance. The fatigue fracture of friction plates has been effectively suppressed after structural optimization.

LATERAL RIM VARIABLE ANGLE LOCKED PLATING VERSUS TENSION BAND WIRING OF SIMPLE AND COMPLEX PATELLA FRACTURES: A BIOMECHANICAL STUDY

Treatment of both simple and complex patella fractures is a challenging clinical problem. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures.Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or a lateral rim variable angle locking plate.Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full knee extension. Interfragmentary movements were captured via motion tracking.For both fracture types, the longitudinal and shear articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p&lt;0.01.Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.