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

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

Tension band versus locking plate fixation for patella fractures - a protocol of a randomised controlled trial.

INTRODUCTION: Following surgical management of patella fractures, patients commonly report pain; difficulties with weight-bearing tasks such as walking, running and climbing stairs; and restrictions in quality of life. Recently, a locking plate system for surgical management of patella fractures has been introduced. To date, no studies have compared standard treatment with tension band wiring with locking plate fixation in a randomised study design. We aim to compare the one-year patient-reported Knee Injury and Osteoarthritis Outcome subscale scores (KOOS5-subscales) after standard care tension band fixation with locking plate fixation for patients with patella fractures. METHODS: This is a multicentre randomised and prospective clinical trial. A total of 122 patients will be included in the study, and the primary outcome will be the KOOS subscales at 12 months after surgery. CONCLUSIONS: Findings from the present study are expected to advance our understanding of outcome following surgical treatment of patella fractures. FUNDING: This study is funded, in part, by the Novo Nordisk Foundation, Denmark. CLINICALTRIALS: gov ID: NCT04891549.

Improving standard volar plate fixation in 3D-guided corrective osteotomy of the distal radius: evaluation of a shim instrument.

Standard volar plates often do not fit the surface of the malunited distal radius after osteotomy, necessitating an offset angle for accurate volar tilt correction. The correction can be achieved if the plate is held at the correct angle when the distal screws are locked. With the advantage of 3D surgical planning and patient-specific instruments, we developed a shim instrument to assist the surgeon in securing the plate at the intended angle when locking the distal screws, and evaluated radiological results. Five female patients aged 63-74 with dorsally angulated extra-articular malunions underwent surgery using 3D-printed guides and the shim instrument. The plate position, drilling guide alignment, screw placements, and distal radius correction on postoperative CTs were compared with the surgical plans. Errors were measured using an anatomical coordinate system, and standard 2D radiographic measures were extracted. Preoperative dorsal tilt ranged from 16° to 35°, and postoperative volar tilt from 1° to 11°. 3D analysis revealed mean absolute correction errors of 6.1° in volar tilt, 1.6° in radial inclination, and 0.6 mm in ulnar variance. The volar tilt error due to the shim instrument, indicated by the mean angle error of the distal screws to the plate, was 2.1° but varied across the five patients. Settling of the distal radius, due to tension during and after reduction, further contributed to a mean loss of 3.5° in volar tilt. The shim instrument helped with securing plates at the intended angle; however, further correction improvements should consider the tension between the fragments of osteoporotic bone.

Comparison between intramedullary nail and conventional plate for displaced intra-articular calcaneal fractures: A meta-analysis.

OBJECTIVES: This study aimed to compare the efficacy and safety of the intramedullary nail and conventional plate for the treatment of displaced intra-articular calcaneal fractures from clinical comparative trials. MATERIALS AND METHODS: A comprehensive search of English databases was carried out in the Springer, PubMed, ScienceDirect, Web of Science, and Cochrane Library databases until September 2023. Studies on calcaneal fractures treated by an intramedullary nail or a plate were considered for inclusion. Endpoints included duration of operation, length of hospital stay, the Visual Analog Scale (VAS) score, postoperative functional score, radiological parameters, and complications. The mean difference (MD) and risk difference (RD) as the combined variables, as well as the 95% confidence intervals, (CIs) were calculated. RESULTS: Five retrospective controlled studies covering 473 feet at the one-year follow-up met the inclusion criteria. The meta-analysis demonstrated that there were significant differences in the duration of operation (MD: -10.81; 95% CI: -16.32, -5.31; p=0.0001), length of hospital stay (MD: -3.65; 95% CI: -4.35, -2.95; p<0.00001). No significant differences were found regarding postoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (MD: 0.36; 95% CI: -3.89, 4.61; p=0.87), VAS (MD: 1.95; 95% CI: -0.30, 4.21; p=0.09), or postoperative Böhler angle (MD: 0.94; 95% CI: -0.04, 1.92; p=0.06) between the two groups. The incidence of total complications (RD: -0.31; 95% CI: -0.46, -0.17; p<0.0001) and wound-healing complications (RD: -0.16; 95% CI: -0.30, -0.03; p=0.02) were lower in the intramedullary nail group. There were no significant differences in the incidences of revision surgery, implant removal, superficial wound infection, deep infection, and nonunion. CONCLUSION: Compared to conventional plates, the intramedullary nail showed a shorter duration of operation, reduced length of hospital stay, and fewer postoperative total complications and wound-healing complications in treating displaced intra-articular calcaneal fractures.

Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement.

OBJECTIVE: Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis. MATERIALS AND METHODS: A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models. RESULTS: The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line. CONCLUSIONS: Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

Use of a novel three-dimensional anatomical plating system for treatment of caudal mandibular fractures in cats: 13 cases (2019-2023).

CASE SERIES SUMMARY: A total of 13 cases of cats with a caudal mandibular fracture treated with a novel surgical technique using the Ramus Anatomical Plate system were reviewed. Preoperative, immediate postoperative and a minimum of 8 weeks postoperative CT images were required as inclusion criteria. The outcome and complications were determined from clinical data and radiographic follow-up examinations. All cases achieved adequate anatomical reduction, resulting in a functional and atraumatic occlusion postoperatively. No intraoperative complications were reported. Time to voluntary food intake was in the range of 1-25 days. No evidence of disruptions to the implants or screw loosening was observed in the 8-week postoperative CT imaging, with radiographic evidence of complete osseous union in all fractures. The most common postoperative complication was swelling at the surgical site. Two cats had postoperative exophthalmos due to retrobulbar haemorrhage, and one cat exhibited partial wound dehiscence 5 days postoperatively, which resolved with medical management. Longer-term complications included intraoral plate exposure in one cat, which required plate removal 10 months postoperatively. RELEVANCE AND NOVEL INFORMATION: In this case series, rigid internal fixation of caudal mandibular fractures using the Ramus Anatomical Plate osteosynthesis system was associated with a minimal complication rate, and satisfactory radiographic and clinical outcomes. The reported outcomes of this novel technique are favourable when compared with previous techniques described for the management of these fracture types.

Biomechanical analysis of plate versus K-wire fixation for metacarpal shaft fractures with wedge-shaped bone defects.

BACKGROUND: Metacarpal shaft fracture is a common type of hand fracture. Numerous studies have explored fixing transverse fractures in the midshaft of the metacarpal bone. However, this section of the metacarpal bone is often susceptible to high-energy injury, resulting in comminuted fracture or bone loss. In such cases, wedge-shaped bone defects can develop in the metacarpal shaft, increasing the difficulty of performing fracture fixation. Notably, the research on this type of fracture fixation is limited. This study compared the abilities of four fixation methods to fix metacarpal shaft fractures with wedge-shaped bone defects. METHODS: In total, 28 artificial metacarpal bones were used. To create wedge-shaped bone defects, an electric saw was used to create metacarpal shaft fractures at the midshaft of each bone. The artificial metacarpal bones were then divided into four groups for fixation. The bones in the first group were fixed with a dorsal locked plate (DP group), those in the second group were fixed with a volar locked plate (VP group), and those in the third group were fixed by combining dorsal and volar locked plates (DP + VP group), and those in the fourth group were fixed with two K-wires (2 K group). Cantilever bending tests were conducted using a material testing machine to measure yielding force and stiffness. The four groups' fixation capabilities were then assessed through analysis of variance and Tukey's test. RESULTS: The DP + VP group (164.1±44.0 N) achieved a significantly higher yielding force relative to the 2 K group (50.7 ± 8.9 N); the DP group (13.6 ± 3.0 N) and VP group (12.3 ± 1.0 N) did not differ significantly in terms of yielding force, with both achieving lower yielding forces relative to the DP + VP group and 2 K group. The DP + VP group (19.8±6.3 N/mm) achieved the highest level of stiffness, and the other three groups did not differ significantly in terms of stiffness (2 K group, 5.4 ± 1.1 N/mm; DP group, 4.0 ± 0.9 N/mm; VP group, 3.9 ± 1.9 N/mm). CONCLUSIONS: The fixation method involving the combined use of dorsal and volar locked plates (DP + VP group) resulted in optimal outcomes with respect to fixing metacarpal shaft fractures with volar wedge bone defects.

The effect of different hybrid rigid internal fixation techniques on the postoperative stability following a mandibular advancement using a bilateral sagittal split ramus osteotomy: A retrospective three-dimensional comparative study.

OBJECTIVE: To three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques. MATERIALS AND METHOD: Seventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS). Measurements were taken pre-operatively (T0), immediately postoperatively (T1), and ≥1 year after surgery (T2) using 3D Slicer software. RESULTS: Age, sex, and follow-up period did not correlate significantly with postoperative relapse or stability. Significant differences were observed in the advancement on the right side between groups II, III, and IV and on the left side between groups I, III, and IV. However, the type of surgical intervention showed no significant effect on postoperative relapse and stability. All groups of fixations showed satisfactory stability with irrelevant relapse (< 2 mm or 2°). CONCLUSION: The study demonstrated satisfactory and comparable stability among different fixation groups on patients undergoing mandibular advancement following bilateral split sagittal osteotomy. The results highlighted the importance of considering the degree of advancement when planning orthognathic surgery and managing postoperative outcomes.

A role for the stringent response in ciprofloxacin resistance in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a major cause of nosocomial infections and the leading cause of chronic lung infections in cystic fibrosis and chronic obstructive pulmonary disease patients. Antibiotic treatment remains challenging because P. aeruginosa is resistant to high concentrations of antibiotics and has a remarkable ability to acquire mutations conferring resistance to multiple groups of antimicrobial agents. Here we report that when P. aeruginosa is plated on ciprofloxacin (cipro) plates, the majority of cipro-resistant (ciproR) colonies observed at and after 48 h of incubation carry mutations in genes related to the Stringent Response (SR). Mutations in one of the major SR components, spoT, were present in approximately 40% of the ciproR isolates. Compared to the wild-type strain, most of these isolates had decreased growth rate, longer lag phase and altered intracellular ppGpp content. Also, 75% of all sequenced mutations were insertions and deletions, with short deletions being the most frequently occurring mutation type. We present evidence that most of the observed mutations are induced on the selective plates in a subpopulation of cells that are not instantly killed by cipro. Our results suggests that the SR may be an important contributor to antibiotic resistance acquisition in P. aeruginosa.

Guided and Prosthetically Driven Bone Augmentation Using the Shell Technique and Allogeneic Cortical Plate: A Prospective Case Series.

PURPOSE: To describe the use of digital technology to surgically guide the shell technique using allogenic cortical plates for a fully guided bone augmentation procedure. MATERIALS AND METHODS: A total of 10 patients who required bone augmentation for implant placement were included in this study. Allogenic cortical plates were planned using CAD/CAM to have identical thickness to the original cortical plates, then were digitally positioned and shaped to outline the bone defect according to the existing anatomical details. A cutting pattern and a surgical template were manufactured according to the digitally preplanned bone graft and the intraoral setting. RESULTS: A total of 12 horizontal bone grafting procedures were performed using the shell technique with allogenic cortical plates. All grafting procedures were deemed successful and allowed for ideal 3D implant positioning. Of the 12 bone grafting procedures, which used a surgical template to position the cortical plate, 3 required an adjustment to reposition the plate to a more ideal position. CONCLUSIONS: Digital technology was used to create a surgical template to guide the shell bone grafting technique with allogenic cortical plates. All surgical templates offered a fixed support to hold the cortical allogenic plate in the preplanned position, offering a predictable, simplified, and accurate guided bone grafting procedure. Further studies on a larger population of patients are necessary to assess those results and to verify the treatment approach described in this study.

A novel model of locking plate and locking spongious screw: a biomechanical in vitro comparison study with classical locking plate.

BACKGROUND: Locking plates are commonly used for the fixation of comminuted, periprosthetic and osteoporotic bone fractures. These plates are secured to the bone with screws, creating a stable connection with fixed angle between the plate and the screws. In this biomechanical in vitro study, our aim is to evaluate and compare the novel locking plate-locking spongious screw model with FDA approved classical locking plate. METHODS: Sawbone PCF-15 osteoporotic bone model was utilized to simulate osteoporotic bone conditions. Two screws were used to attach both the classical locking plate and the novel locking plate-locking spongious screw model to these bone models. The attachment strength of the screws to the bone blocks was measured by pull-out tests. RESULTS: Novel locking plate-locking spongious screw model exhibited an 84.38% stronger attachment to the osteoporotic bone model compared to the current locking plate model. CONCLUSIONS: In conclusion, one of the important problems in the locking plates which is the high Pull-out risk of the locking spongious screws can been resolved with our proposed new model and has a chance of having a better purchase especially in osteoporotic bones.

[Development and clinical application of lateral segmental positioning plates of the body surface spine].

OBJECTIVE: To investigate the clinical efficacy of body-surface guide plates for lateral segmental positioning in the thoracolumbar spine. METHODS: From March 2018 to March 2021, 768 gerontal patientss underwent percutaneous vertebroplasty with balloon dilatation due to thoracolumbar compression fracturess, 356 males and 412 females. aged from 64 to 92 years old with an average of (77.9±13.5) years old. All patients were treated in hospital within 1 week after injury. All patients underwent preoperative localization, and were divided into localization plate group and locator group according to different localization methods. There were 390 patients in the localization plate group, 180 males and 210 females, aged from 64 to 92 years old, with an average age of (78.4±14.3) years old. There were 378 patients in the locator group, 176 males and 202 females, aged from 64 to 90 years old, with an average age of (77.5±13.4) years old. After preliminary positioning with the above two methods, skin markers were made, cloth was routinely disinfected, and the spinal lateral position was fluoroscopically examined after the fine needle was inserted into the marked point and the vertical body at the near tail end. The accuracy of the original positioning method was evaluated. The number of times, time and accuracy of positioning of the two groups of patients were compared and analyzed. RESULTS: The specific data of patient positioning in the two groups were collected for statistical analysis. The number of times of fluoroscopy in the positioning plate group and the locator group was(3.3±0.5) times and (5.0±1.2) times, and the positioning time was (60.4±9.4) s and (105.0±30.9) s, respectively. The accuracy of fluoroscopy was 97.5% (380/390) and 85.7% (324/378), respectively, with statistical significance (P<0.05). CONCLUSION: The lateral segmental positioning plate of the body surface spine has the advantages of simple operation, accurate positioning, and reducing X-ray radiation for patients, which is worthy of clinical application.

[Comparative study of minimally invasive titanium elastic nail and steel plate on the treatment of fracture of tibiofibular fracture in adults].

OBJECTIVE: To compare the clinical outcomes of using elastic intramedullary nail and plate to fix fibular fracture. METHODS: The 60 patients with tibiofibular fractures admitted from January 2015 to December 2022 were divided into two groups:intramedullary nail group and plate group, 30 cases each, intramedullary nail group was treated with elastic intramedullary nail fixation group, plate group was treated with steel plate and screw fixation group. Intramedullary nail group, there were 18 males and 12 females, aged from 22 to 75 years old with an average of (39.4±9.8) years old, including 24 cases of traffic accidents injury, 6 cases of falling injury, 23 cases of closed fractures, 7 cases of open fractures. Steel plate group, there were 15 males and 15 females, aged from 24 to 78 years old with an average of (38.6±10.2) years old. The 22 cases were injured by traffic accident, 8 cases were injured by falling. The 24 cases were closed fractures and 6 cases were open fractures. The operation time, intraoperative bleeding, American Orthopedic Foot and Ankle Society (AOFAS) ankle and hind foot scores, clinical healing time of fibula and the incidence of wound complications were compared between the two groups. RESULTS: The patients in both groups were followed up for 6 to 21 months, with an average of (14.0±2.8) months. Compared with plate group, intramedullary nail group had shorter operative time, less bleeding, shorter clinical healing time of fibula, and lower infection rate of incision, and the difference was statistically significant (P<0.05). There were 2 cases of delayed healing in intramedullary nail group, 1 case of nonunion in plate group, and 2 cases of delayed healing in plate group, and there was no statistically significant difference between the two groups (P>0.05). In the last follow-up, according to the AOFAS scoring standard, the ankle function in intramedullary nail group was excellent in 17 cases, good in 12 cases, fair in 1 case, with an average of (88.33±4.57) points, while in plate group, excellent in 16 cases, good in 10 cases, fair in 4 cases, with an average of (87.00±4.14) points;There was no statistical difference between the two groups (P>0.05). CONCLUSION: Elastic intramedullary nail has the advantages of short operation time, less intraoperative bleeding, short fracture healing time and less incision complications in the treatment of fibular fracture, which is worthy of clinical application.

Robotic-assisted plate fixation of the anterior acetabulum - clinical description of a new technique.

INTRODUCTION: We present a detailed procedure for the robotic-assisted plate osteosynthesis of an anterior acetabular fracture. The purpose of this work was to describe a robotic-assisted minimally invasive technique as a possible method for reducing complications, pain, and hospitalization. Another goal was to present technical recommendations and to assess potential pitfalls and problems of the new surgical approach. METHODS: Surgery was performed in an interdisciplinary setting by an experienced orthopedic surgeon and a urologist. The DaVinci System with standard instruments was used. Reduction was achieved through indirect traction of a pin that was introduced into the femoral neck and direct manipulation via the plate. The plate position and fixation were achieved through 7 additional minimally invasive incisions. RESULTS: The technique has multiple advantages, such as no detachment of the rectus abdominal muscle, a small skin incision, and minimal blood loss. Furthermore, this approach might lower the incidence of hernia formation, infection, and postoperative pain. DISCUSSION: We see the presented technique as a demanding yet progressive and innovative surgical method for treating acetabular fractures with indications for anterior plate fixation. TRIAL REGISTRATION: The study was approved by the local institutional review board (Nr. 248/18).

Treatment of presumed aseptic non-union of the humeral shaft by osteosynthesis combining intramedullary nailing and screw plate.

In 2020, the most common treatment for presumed aseptic non-union of the humeral shaft seems to be decortication, often associated with bone autografting, and stabilized by a screw plate. We propose to evaluate an original technique of rigid osteosynthesis combining intramedullary nailing and screw plate. Between January 2004 and January 2020, 45 patients underwent treatment of presumed aseptic non-union of the humeral shaft by osteosynthesis combining intramedullary nailing and a screw plate. The minimum radio-clinical follow-up was one year postoperatively. The series included 19 men and 26 women with a mean age of 53 years (range 19-84 years). Bone consolidation was achieved in 43 patients, a rate of 95.5%. Comparing patients who achieved bone consolidation with the two failed consolidations did not reveal any statistically significant factor. Interobserver agreement was almost perfect (k=0.93) for the use of the RUST for humeral shaft fractures treated with intramedullary nailing and screw plate. In our study, the treatment of presumed aseptic non- union of the humeral shaft with an osteosynthesis combining intramedullary nailing and screw plate gives, with 95.5% of bone consolidation, results equal to or even superior to the different treatments currently described in the literature.

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.

Determination of the ideal plate for medial femoral condyle fracture fixation: an anatomical fit and biomechanical study.

BACKGROUND: The aim of this study is to determine the best plate to use as a substitute to fix a medial femoral condyle fracture. MATERIALS AND METHODS: The first part is to measure the best fit between several anatomical plates including the Proximal Tibia Anterolateral Plate (PT AL LCP), the Proximal Tibia Medial Plate (PT M LCP), the Distal Tibia Medial Locking Plate (DT M LCP) and the Proximal Humerus (PHILOS) plate against 28 freshly embalmed cadaveric distal femurs. Measurements such as plate offset and number of screws in the condyle and shaft shall be obtained. The subsequent part is to determine the compressive force at which the plate fails. After creating an iatrogenic medial condyle fracture, the cadavers will be fixed with the two plates with the best anatomical fit and subjected to a compression force using a hydraulic press. RESULTS: The PT AL LCP offered the best anatomical fit whereas the PHILOS plate offered the maximal number of screws inserted. The force required to create 2 mm of fracture displacement between the two is not statistically significant (LCP 889 N, PHILOS 947 N, p = 0.39). The PT AL LCP can withstand a larger fracture displacement than the PHILOS (LCP 24.4 mm, PHILOS 17.4 mm, p = 0.004). DISCUSSION AND CONCLUSION: Both the PT AL LCP and the PHILOS remain good options in fixing a medial femoral condyle fracture. Between the two, we would recommend the PT AL LCP as the slightly superior option.

Experimental investigation of ultrasonic assisted coating on three-point bending behavior of 3D printed polymeric bone plates for biomedical applications.

3D printed Poly Lactic Acid (PLA) bone plates exhibit limited three-point bending strength, restricting their viability in biomedical applications. The application of polydopamine (PDM) enhances the three-point bending strength by undergoing covalent interactions with PLA molecular structure. However, the heavy nature of PDM particles leads to settling at the container base at higher coating solution concentrations. This study investigates the impact of ultrasonic-assisted coating parameters on the three-point bending strength. Utilizing Response Surface Methodology (RSM) for statistical modeling, the study examines the influence of ultrasonic vibration power (UP), coating solution concentration (CC), and submersion time (TIME). RSM optimization recommended 100 % UP, 6 mg/ml CC, and 150 min TIME, resulting in maximum three-point bending strength of 83.295 MPa. Microscopic images from the comparative analysis revealed non-uniform coating deposition with mean thickness of 6.153 µm under normal coating. In contrast, ultrasonic-assisted coating promoted uniform deposition with mean thickness of 18.05 µm. The results demonstrate that ultrasonic-assisted coating induces PDM particle collision, preventing settling at the container base, and enhances three-point bending strength by 7.27 % to 23.24 % compared to the normal coating condition. This study emphasizes on the potential of ultrasonic-assisted coating to overcome the limitations of direct immersion coating technique.

Critical loss of primary implant stability in osteosynthesis locking screws under cyclic overloading.

Primary implant stability, which refers to the stability of the implant during the initial healing period is a crucial factor in determining the long-term success of the implant and lays the foundation for secondary implant stability achieved through osseointegration. Factors affecting primary stability include implant design, surgical technique, and patient-specific factors like bone quality and morphology. In vivo, the cyclic nature of anatomical loading puts osteosynthesis locking screws under dynamic loads, which can lead to the formation of micro cracks and defects that slowly degrade the mechanical connection between the bone and screw, thus compromising the initial stability and secondary stability of the implant. Monotonic quasi-static loading used for testing the holding capacity of implanted screws is not well suited to capture this behavior since it cannot capture the progressive deterioration of peri­implant bone at small displacements. In order to address this issue, this study aims to determine a critical point of loss of primary implant stability in osteosynthesis locking screws under cyclic overloading by investigating the evolution of damage, dissipated energy, and permanent deformation. A custom-made test setup was used to test implanted 2.5 mm locking screws under cyclic overloading test. For each loading cycle, maximum forces and displacement were recorded as well as initial and final cycle displacements and used to calculate damage and energy dissipation evolution. The results of this study demonstrate that for axial, shear, and mixed loading significant damage and energy dissipation can be observed at approximately 20 % of the failure force. Additionally, at this load level, permanent deformations on the screw-bone interface were found to be in the range of 50 to 150 mm which promotes osseointegration and secondary implant stability. This research can assist surgeons in making informed preoperative decisions by providing a better understanding of the critical point of loss of primary implant stability, thus improving the long-term success of the implant and overall patient satisfaction.

[Surgical Stabilization of Traumatic Multiple Rib Fractures Using Absorbable Osteosynthesis Agent(u-HA/PLLA Composite Material)].

In case that met several indication criteria with 4 or more rib fractures, we performed surgical stabilization of multiple fractured ribs using a plate and screw system( Super FIXORB MX) that was made of uncalcined hydroxyapatite (u-HA)/poly-L-lactic acid (PLLA) composite material with excellent bioactivity and absorbability. We report our clinical experience of 7 cases in which this device was used. Although there is still room for further consideration of the technique and the strength of the device itself, computed tomography( CT) images taken 9 months after surgery showed that the fixative device was almost assimilated with the bone at the fracture repair site in cases where fixation was successful.