Anterolateral Dual Plate Fixation for Distal Metaphyseal-Diaphyseal Junction Fractures of the Humerus: Biomechanical Finite Element Analysis with Clinical Results.

Background: Distal metaphyseal-diaphyseal junction fractures of the humerus are a subset of injuries between humeral shaft fractures and distal intra-articular humerus fractures. A lack of space for distal fixation and the unique anatomy of concave curvature create difficulties during operative treatment. The closely lying radial nerve is another major concern. The aim of this study was to determine whether anterolateral dual plate fixation could be effective for a distal junctional fracture of the humerus both biomechanically and clinically. Methods: A right humerus 3-dimensional (3D) model was obtained based on plain radiographs and computed tomography data of patients. Two fractures, a spiral type and a spiral wedge type, were constructed. Three-dimensional models of locking compression plates and screws were constructed using materials provided by the manufacturer. The experiment was conducted by using COMSOL Multiphysics, a finite element analysis, solver, and simulation software package. For the clinical study, from July 2008 to March 2021, a total of 72 patients were included. Their medical records were retrospectively reviewed to obtain patient demographics, elbow range of motion, Disabilities of the Arm, Shoulder and Hand (DASH) scores, Mayo Elbow Performance Scores (MEPS), and hand grip strength. Results: No fracture fixation construct completely restored stiffness comparable to the intact model in torsion or compression. Combinations of the 7-hole and 5-hole plates and the 8-hole and 6-hole plates showed superior structural stiffness and stress than those with single lateral plates. At least 3 screws (6 cortices) should be inserted into the lateral plate to reduce the load effectively. For the anterior plate, it was sufficient to purchase only the near cortex. Regarding clinical results of the surgery, the range of motion showed satisfactory results in elbow flexion, elbow extension, and forearm rotation. The average DASH score was 4.3 and the average MEPS was 88.2. Conclusions: Anterolateral dual plate fixation was biomechanically superior to the single-plate method in the finite element analysis of a distal junctional fracture of the humerus model. Anterolateral dual plate fixation was also clinically effective in a large cohort of patients with distal junctional fractures of the humerus.

Zero-profile implant system versus novel plate systems after ACDF for comparison of sagittal balance parameters and clinical efficacy analysis.

BACKGROUND: The zero-profile implant system (Zero-P) and conventional plates have been widely used in anterior cervical discectomy and fusion (ACDF) to treat cervical spondylosis. The purpose of this study was to compare the effects of the application of Zero-P and new conventional plates (ZEVO, Skyline) in ACDF on the sagittal imaging parameters of cervical spondylosis patients and to analyze their clinical efficacy. METHODS: We conducted a retrospective study on 119 cervical spondylosis patients from January 2018 to December 2021, comparing outcomes between those receiving the Zero-P device (n = 63) and those receiving a novel conventional plate (n = 56, including 46 ZEVO and 10 Skyline plates) through ACDF. Cervical sagittal alignment was assessed pre- and postoperatively via lateral radiographs. The Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and visual analog scale (VAS) scores were recorded at baseline, after surgery, and at the 2-year follow-up to evaluate patient recovery and intervention success. RESULTS: There were significant differences in the postoperative C0-C2 Cobb angle and postoperative sagittal segmental angle (SSA) between patients in the novel conventional plate group and those in the Zero-P group (P < 0.05). Postoperatively, there were significant changes in the C2‒C7 Cobb angle, C0‒C2 Cobb angle, SSA, and average surgical disc height (ASDH) compared to the preoperative values in both patient groups (P < 0.05). Dysphagia in the immediate postoperative period was lower in the Zero-P group than in the new conventional plate group (0% in the Zero-P group, 7.14% in the novel conventional plate group, P = 0.046), and the symptoms disappeared within 2 years in both groups. There was no statistically significant difference between the two groups in terms of complications of adjacent spondylolisthesis (ASD) at 2 years postoperatively (3.17% in the Zero-P group, 8.93% in the novel conventional plate group; P = 0.252). According to the subgroup analysis, there were significant differences in the postoperative C2‒C7 Cobb angle, C0‒C2 Cobb angle, T1 slope, and ASDH between the ZEVO group and the Skyline group (P < 0.05). Compared with the preoperative scores, the JOA, NDI, and VAS scores of all groups significantly improved at the 2-year follow-up (P < 0.01). According to the subgroup analysis, the immediate postoperative NDI and VAS scores of the ZEVO group were significantly better than those of the Skyline group (P < 0.05). CONCLUSION: In ACDF, both novel conventional plates and Zero-P can improve sagittal parameters and related scale scores. Compared to the Zero-P plate, the novel conventional plate has a greater advantage in correcting the curvature of the surgical segment, but the Zero-P plate is less likely to produce postoperative dysphagia.

Comparative efficacy of zero-profile implant and conventional cage-plate implant in the treatment of single-level degenerative cervical spondylosis: a systematic review and meta-analysis.

BACKGROUND: In recent years, the zero-profile implant (Zero-p) has emerged as a promising internal fixation technique. Although studies have indicated its potential superiority over conventional cage-plate implant (Cage-plate) in the treatment of degenerative cervical spondylosis, there remains a lack of definitive comparative reports regarding its indications, safety, and efficacy. METHODS: A computerized search was conducted on English and Chinese databases, including PubMed, Web of Science, Cochrane Library, EMBASE, CNKI, Wanfang and VIP. Additionally, a manual search was meticulously carried out on Chinese medical journals, spanning from the inception of the respective databases until August 2023. The meta-analysis utilized a case-control study approach and was executed through the utilization of RevMan 5.3 software. Stringent quality evaluation and data extraction procedures were implemented to guarantee the reliability and validity of the findings. RESULTS: Nine high-quality studies with 808 patients were included. Meta-analysis showed that the operation time (MD = - 13.28; 95% CI (- 17.53, - 9.04), P < 0.00001), intraoperative blood loss (MD = - 6.61; 95% CI (- 10.47, - 2.75), P = 0.0008), incidence of postoperative dysphagia at various time points: within the first month after surgery (OR = 0.36; 95% CI (0.22, 0.58), P < 0.0001), 1-3 months after surgery (OR = 0.20; 95% CI (0.08, 0.49), P = 0.0004), the final follow-up (OR = 0.21; 95% CI (0.05, 0.83), P = 0.003) and the rate of postoperative adjacent disc degeneration (OR = 0.46; 95% CI (0.25, 0.84), P = 0.01) were significantly lower in the Zero-p group than in the Cage-plate group. Additionally, was also significantly lower in the Zero-p group. However, there were no significant differences in the JOA score, the final follow-up NDI score, surgical segmental fusion rate, postoperative height of adjacent vertebrae, or postoperative subsidence rate between the two groups. CONCLUSION: In summary, when treating single-segment degenerative cervical spondylosis, both internal fixation techniques are reliable and effective. However, Zero-P  implant offer several advantages over cage-plate implant, including shorter operation duration, less intraoperative blood loss, reduced postoperative dysphagia, and slower adjacent disc degeneration. Additionally, Zero-P implant has a broader application space, making them a preferred choice in certain cases.

[Comparison of open reduction hollow nail anchoring system with loop plate fixation under arthroscopy for the treatment of posterior cruciate ligament avulsion fractures].

OBJECTIVE: To compare clinical effect between open reduction and fixation with cannulated screw and threaded rivet via posteromedial approach versus arthroscopic Endobutton plate fixation in treating posterior cruciate ligament avulsion fractures. METHODS: Clinical data of 38 patients with posterior cruciate ligament avulsion fractures from July 2020 to December 2021 were analyzed retrospectively, and divided into open reduction and internal fixation group (posterior medial approach hollow anchor system fixation) and arthroscopic fixation group (Endobutton with loop plate fixation under arthroscopy). There were 20 patients in open reduction and internal fixation group, including 16 males and 4 females, aged from 26 to 74 years old with an average of (42.9±18.8) years old;13 patients on the left side and 7 patients on the right side;12 patients were classified to typeⅡand 8 patiens with type Ⅲ according to Meyers-McKeever fractures classification;14 patients were gradeⅡand 6 patients were grade Ⅲ in back drawer test. There were 18 patients in arthroscopic fixation group, including 11 males and 7 females;aged from 24 to 70 years old with an average of (53.5±13.4) years old;11 patients on the left side and 7 patients on the right side;10 patients were classified to typeⅡand 8 patiens with type Ⅲ according to Meyers-McKeever fractures classification;11 patients were gradeⅡand 7 patients were grade Ⅲ in back drawer test. Operation time, blood loss, and quality of immediate reduction were compared between two groups. Knee range of motion, knee back drawer test, and International Knee Documentation Committee(IKDC) grading, KT2000 stability evaluation and Lysholm function score of knee joint were compared at 6 months after operation. RESULTS: All patients were followed up for 8 to 16 months with an average of (12.3±1.9) months. There were no complications such as incision infection, fracture malunion or non-union, and internal fixation loosening occurred. The avulsion fractures of knee joint were reached to imaging healing standard at 6 months after operation. Operation time and blood loss in open reduction and internal fixation group were (56.4±7.1) min and (63.2±10.2) ml, while (89.9±7.4) min and (27.7±8.7) ml in arthroscopic fixation group, respectively, and had significant difference between two groups (P<0.05). There were no differences in immediate reduction quality (χ2=0.257, P=0.612), knee joint range of motion at 6 months after opertaion (t=0.492, P=0.626), knee joint rear drawer test ( χ2=0.320, P=0.572), IKDC classification of knee joint (χ2=0.127, P=0.938), KT2000 stability evaluation (χ2=0.070, P=0.791), and knee Lysholm function score (t=0.092, P=0.282) between two groups. CONCLUSION: Posterior medial approach with hollow anchoring system fixation and arthroscopic Endobutton with loop plate fixation for the treatment of posterior cruciate ligament tibial occlusion avulsion fracture could achieve satisfactory clinical results, and arthroscopic surgery has less bleeding, but also has a longer learning curve and longer operation time than traditional incision surgery. The surgeon needs to make a choice according to clinical situation of patient and their own surgical inclination.

[Single mini-incision combined with honeycomb titanium plate in treatment of acute acromioclavicular joint dislocation].

OBJECTIVE: To explore clinical effect of single small incision with honeycomb titanium plate in treating acute acromioclavicular dislocation. METHODS: The clinical data of 40 patients with acute acromioclavicular dislocation admitted from December 2019 to December 2021 were retrospectively analyzed and divided into two groups according to different surgical methods. Among them, 20 patients were fixed with single small incision with honeycomb titanium plate (titanium plate group), including 11 males and 9 females, aged from 23 to 65 years old with an average of (47.40±12.58) years old;12 patients on the left side, 8 patients on the right side;11 patients with type Ⅲ, 3 patients with type Ⅳ, and 6 patients with type Ⅴ according to Rockwood classification. Twenty patients were fixed with clavicular hook plate (clavicular hook group), including 8 males and 12 females, aged from 24 to 65 years old with an average of (48.40±12.08) years old;12 patients on the left side, 8 patients on the right side;10 patients with type Ⅲ, 2 patients with type Ⅳ, and 8 patients with type Ⅴ according to Rockwood classification. Operative time, incision length, intraoperative blood loss, hospital stay, visual analogue scale (VAS) and Constant-Murley score of shoulder joint function were compared between two groups. Anteroposterior radiographs of the affected shoulder joint were recorded before, immediately and 6 months after surgery, and the coracoclavicular distance was measured and compared. RESULTS: Both groups of patients were successfully completed operation without serious complications. All patients were followed up for 6 to 15 months with an average of (11.9±4.8) months. There were no incisional infection, internal plant fracture or failure, bone tunnel fracture and other complications occurred. The incision length of titanium plate group (35.90±3.14) mm was significantly shorter than that of clavicular hook group (49.30±3.79) mm (P<0.05). There were no significant difference in operative time, intraoperative blood loss and hospital stay between two groups (P>0.05). At 1 and 3 months after operation, VAS of titanium plate group was lower than that of clavicular hook group (P<0.05). Connstant-Murley scores in titanium plate group at 1, 3 and 6 months after operation were (86.80±1.36), (91.60±2.32) and (94.90±2.22), respectively;and in clavicular hook group were (78.45±5.47), (85.55±2.01) and (90.25±1.92), which were higher than that of clavicular hook group (P<0.05). There was no significant difference in coracoclavicular distance between two groups immediately and 6 months after operation(P>0.05). CONCLUSION: For the treatment of acute acromioclavicular joint dislocation, single small incision combined with honeycomb titanium plate have advantages of shorter incision, fast recovery of shoulder joint function without the second operation, and has good satisfaction of patient.

[Application of modified Frosch approach for Schatzker typeâ ¡tibial plateau fractures with posterolateral column].

OBJECTIVE: To explore clnical efficacy of modified Frosch approach for Schatzker typeⅡtibial plateau fracture with posterolateral column. METHODS: From January 2019 to September 2020, totally 11 patients with Schatzker typeⅡtibial plateau fractures with posterolateral column were treated, including 7 males and 4 females, aged from 21 to 49 years old. Modified Frosch approach was adopted for lateral decubitus position, and posterolateral fractures were fixed with support plates or posterolateral screws. Anterolateral fixation with conventional tibial plateau lateral locking plate. Tibial plateau varus angle and posterior inclination angle were measured by X-ray immediately and 12 months after operation, as well as knee motion at 12 months after operation. Knee function at 12 months after operation was evaluated by knee score of Hospital for Special Surgery(HSS). RESULTS: Eleven patients were followed up for 12 to 15 months. Varus angle and inclination angle at immediately after operation ranged from 76° to 86° and 6° to 10°, respectively, and 79° to 88° and 6° to 10°, respectively at 12 months after operation. The range of extension of knee ranged from 0° to 5°, and flexion was 106° to 137° at 12 months after operation. Postoperative HSS knee score at 12 months ranged from 74 to 94 scores, 8 patients were excellent and 3 good. CONCLUSION: Modified Frosch approach is an effective surgical method for Schatzker typeⅡtibial plateau fracture with posterolateral column. A single incision is used to complete fracture exposure and fixation at two sites, avoiding use of combined incisions, and could obtain good postoperative knee joint function. During operation, popliteal fossa structure should be familiar, and the common peroneal nerve should be protected to avoid injury.

Multicenter, Prospective, Observational Study of Nonoperative Versus Operative Treatment for High-Energy Midshaft Clavicle Fractures.

OBJECTIVES: Evaluate if nonoperative or operative treatment of displaced clavicle fractures delivers reduced rates of nonunion and improved Disability of the Arm, Shoulder, and Hand (DASH) scores. DESIGN: Multicenter, prospective, observational. SETTING: Seven Level 1 Trauma Centers in the United States. PATIENT SELECTION CRITERIA: Adults with closed, displaced (100% displacement/shortened >1.5 cm) midshaft clavicle fractures (Orthopaedic Trauma Association 15.2) were treated nonoperatively, with plates and screw fixation, or with intramedullary fixation from 2003 to 2018. OUTCOME MEASURES AND COMPARISONS: DASH scores (2, 6 weeks, 3, 6, 12, and 24 months), reoperation, and nonunion were compared between the nonoperative, plate fixation, and intramedullary fixation groups. RESULTS: Four hundred twelve patients were enrolled, with 203 undergoing plate fixation, 26 receiving intramedullary fixation, and 183 treated nonoperatively. The average age of the nonoperative group was 40.1 (range 18-79) years versus 35.8 (range 18-74) in the plate group and 39.3 (range 19-56) in the intramedullary fixation group (P = 0.06). One hundred forty (76.5%) patients in the nonoperative group were male compared with 154 (75.9%) in the plate group and 18 (69.2%) in the intramedullary fixation group (P = 0.69). All groups showed similar DASH scores at 2 weeks, 12 months, and 24 months (P > 0.05). Plate fixation demonstrated better DASH scores (median = 20.8) than nonoperative (median = 28.3) at 6 weeks (P = 0.04). Intramedullary fixation had poorer DASH scores at 6 weeks, 3 months, and 6 months than plate fixation and worse DASH scores than nonoperative at 6 months (P < 0.05). The nonunion rate for nonoperative treatment (14.6%) was significantly higher than the plate group (0%) (P < 0.001). CONCLUSIONS: Operative treatment of displaced clavicle fractures provided lower rates of nonunion than nonoperative treatment. Except at 6 weeks, no difference was observed in DASH scores between plate fixation and nonoperative treatment. Intramedullary fixation resulted in worse DASH scores than plate fixation at 6 weeks, 3 months, and 6 months and worse DASH scores than nonoperative at 6 months. Implant removal was the leading reason for reoperation in the plate and intramedullary fixation groups, whereas surgery for nonunion was the primary reason for surgery in the nonoperative group. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

A Novel Bone-Screw-Fastener Demonstrates Greater Maximum Compression Force Before Failure Compared With a Traditional Buttress Screw.

OBJECTIVES: This study compared the maximal compression force before thread stripping of the novel bone-screw-fastener (BSF) with the traditional buttress screw (TBS) in synthetic osteoporotic and cadaveric bone models. METHODS: The maximum compression force of the plate-bone interface before loss of screw purchase during screw tightening was measured between self-tapping 3.5-mm BSF and 3.5-mm TBS using calibrated load cells. Three synthetic biomechanical models were used: a synthetic osteoporotic diaphysis (model 1), a 3-layer biomechanical polyurethane foam with 50-10-50 pounds-per-cubic-foot layering (model 2), and a 3-layer polyurethane foam with 50-15-50 pounds-per-cubic-foot layering (model 3). For the cadaveric metaphyseal model, 3 sets of cadaveric tibial plafonds and 3 sets of cadaveric tibial plateaus were used. A plate with sensors between the bone and plate interface was used to measure compression force during screw tightening in the synthetic bone models, while an annular load cell that measured screw compression as it slid through a guide was used to measure compression in the cadaver models. RESULTS: Across all synthetic osteoporotic bone models, the BSF demonstrated greater maximal compression force before stripping compared with the TBS [model 1, 155.51 N (SD = 7.77 N) versus 138.78 N (SD = 12.74 N), P = 0.036; model 2, 218.14 N (SD = 14.15 N) versus 110.23 N (SD = 8.00 N), P < 0.001; model 3, 382.72 N (SD = 20.15) versus 341.09 N (SD = 15.57 N), P = 0.003]. The BSF had greater maximal compression force for the overall cadaver trials, the tibial plafond trials, and the tibial plateau trials [overall, 111.27 N vs. 97.54 N (SD 32.32 N), P = 0.002; plafond, 149.6 N versus 132.92 N (SD 31.32 N), P = 0.006; plateau, 81.33 N versus 69.89 N (SD 33.38 N), P = 0.03]. CONCLUSIONS: The novel bone-screw-fastener generated 11%-65% greater maximal compression force than the TBS in synthetic osteoporotic and cadaveric metaphyseal bone models. A greater compression force may increase construct stability, facilitate early weight-bearing, and reduce construct failure.

Efficacy of intramedullary bridge fixation for midshaft clavicle fractures: a retrospective analysis of a novel technique.

BACKGROUND: The aim of this study was to explore the efficacy of a novel intramedullary fixation technique using the ortho-bridge system (OBS) for midshaft clavicle fractures. METHODS: A total of 63 patients were included in this study: 35 underwent plate internal fixation (LP group) and 28 underwent OBS intramedullary fixation (OBS group). Surgical time, intraoperative blood loss, incision length, fracture healing time, removal of the internal fixation agent, visual analog scale (VAS) score for shoulder pain, Constant-Murley shoulder score and complication occurrence were compared between the two groups. RESULTS: Preoperative general data, such as sex, age and fracture type, were not significantly different between the two groups (P > 0.05). However, the OBS group exhibited better outcomes than the LP group exhibited in terms of surgical time, intraoperative blood loss and total incision length (P < 0.05). Additionally, the OBS group exhibited a significantly shorter fracture healing time and internal-fixation removal time than the LP group exhibited (P < 0.05). The VAS scores on postoperative day 1, week 1, month 1 and month 3 were lower in the OBS group than in the LP group (P < 0.05). Furthermore, the Constant-Murley shoulder scores at 1, 3, and 6 months postoperatively were higher in the OBS group than in the LP group (P < 0.05), with no significant difference at 1 year after surgery (P > 0.05). None of the patients in the OBS group experienced scarring of the surgical incision, and 6 patients in the LP group experienced scarring of the surgical incision. Finally, the complication incidence in the OBS group was lower than that in the LP group. CONCLUSION: For midshaft clavicle fractures, OBS intramedullary fixation is better than locking-plate internal fixation because it led to less trauma, a faster recovery, better efficacy, and better esthetic outcomes and comfort. Therefore, this technique may have potential as a novel treatment for midshaft clavicle fractures. LEVEL OF EVIDENCE: III, retrospective observational study.

Modified-tension band suturing: 'the pulling the reins technique' - a technique for displaced proximal humeral fracture with medial column instability.

Fractures of the proximal humerus with medial column instability are challenging and present an unacceptable rate of complications and reoperations. Despite good results reported with the use of locking plates and augmentation techniques using bone graft or a second plate, varus subsidence and fixation failure have been frequently reported. We describe the case of a patient presenting with a complex, multifragmentary proximal humerus fractures successfully treated with open anatomic reduction and internal fixation using a locking plate augmented with lateral traction using three bone anchors in the humerus head. After 18 months, the patient reported fully recovering the mobility and functionality of the operated shoulder. The use of bone anchors pulling the humeral in three different directions like three vectors applied from medial to lateral, posterior to anterior and lateral to anterior help to reduce the most important deformities (varus and retroversion) by applying the tension band principle. This is an interesting approach to avoid primary and secondary reduction loss of the proximal fractures of the humerus with postero-medial cortical defect. The procedure is a good alternative to be used in patients with failure or insufficiency of the medial wall and marked varus.

Intraoperative assessment of the dorso-ulnar fragment stability with stress fluoroscopy: An observational study.

This study aims to investigate the effectiveness of intraoperative stress radiographs in evaluating the stability and fixation adequacy of the dorso-ulnar fragment (DUF) after volar plate application. Sixty-four patients who underwent open reduction and internal fixation due to comminuted distal radius fracture accompanied by DUF between May 2020 and February 2022 were reviewed retrospectively. Two groups were compared, with and without stress radiographs used in addition to routine fluoroscopic imaging during the surgical treatment of distal radius fractures. DUF sizes and fracture classifications were made according to preoperative computed tomography. Displacement of the DUF, dorsal cortex screw penetration, and the number of screws inserted into the DUF were evaluated on immediate postoperative CT scans and direct radiographs. DUF displacement at the patients' last follow-up was significantly higher in the control group (1.62 mm) than in the additional stress fluoroscopy applied group (0.53 mm). It was observed that the amount of displacement increased as the dorso-volar size of the DUF decreased. No significant difference was observed in dorsal cortex screw penetrations between the 2 groups. In the additional stress fluoroscopy applied group, stabilization rates with at least 1 screw over volar-locking plate for DUF were significantly higher (P < .001). Compared to the stress fluoroscopy group, the change in ulnar variance (P < .001) and volar tilt (P < .001) was significantly higher in the control group in the last follow-up radiography. No significant difference was observed between the implant removal rates of both groups. Evaluation of the stability of the DUF with stress radiographs after fixation is an effective method to reveal the need for additional fixation. Dorsal stress radiographs allow dynamic evaluation of fixation strength.

Outcomes of Anterior Lateral Approach and Gerdy's Tubercle Osteotomy for Tibial Plateau Fractures Involving the Posterior Lateral Condyle: A Retrospective Study of 20 Patients.

BACKGROUND The objective of this investigation was to assess the effectiveness of using T-shaped steel plates through the anterior lateral approach and Gerdy's tubercle osteotomy for treating posterior lateral tibial plateau fractures. MATERIAL AND METHODS A retrospective analysis was conducted on clinical data from 20 patients, aged on average 53.9±10.36 years, who were admitted for tibial plateau fractures involving the posterior lateral condyle between January 2019 and October 2022. The fixation and reduction of the posterior lateral bone block were performed using the anterior lateral approach combined with Gerdy's tubercle osteotomy to address the posterior lateral tibial plateau fracture. Post-surgery assessment was conducted using the Hospital for Special Surgery (HSS) knee combined score. RESULTS During the 12-24 (14.2±1.7) month postoperative period, we conducted 20 surgeries. Within 9 to 12 weeks, fracture healing transpired without any complications such as incision infection, nerve injury, or fracture displacement being detected. Assessment of knee joint function at the final follow-up was conducted using the HSS knee combined score, with results indicating 16 cases rated as excellent, 3 cases as good, and 1 case as fair. CONCLUSIONS In tibial plateau fractures impacting the posterior lateral condyle, the anterior lateral approach, combined with Gerdy's tubercle osteotomy, allows for direct exposure and manipulation of the posterior lateral bone block fracture. Using a T-shaped support plate and a lateral locking plate provides a reliable method for fracture fixation, aiding in convenient surgical positioning and intraoperative fluoroscopy. The treatment approach effectively manages fractures located on the posterior lateral aspect of the tibial plateau.

Comparison of the biomechanical behavior between commercial and 3D-printed patient-specific Ti6Al4V L-Shaped titanium plates following le fort i osteotomy using finite element analysis: A technical Note.

OBJECTIVE: To evaluate and compare the biomechanical behavior of three-dimensionally (3D) printed patient-specific Ti6Al4V with commercially made titanium mini plates following Lefort-I osteotomy using finite element analysis. METHODS: Le Fort I osteotomy was virtually simulated with a 5 mm maxillary advancement and mediolateral rotation in the coronal plane, resulting in a 3 mm gap on the left side's posterior. Two fixation methods were modeled using software to compare 3D-printed Ti6Al4V and commercial titanium mini plates, both featuring a 4-hole l-shape with thicknesses of 0.5 mm and 0.7 mm at the strategic piriform rim and zygomaticomaxillary buttress locations. Using ANSYS R19.2, finite element models were developed to assess the fixation plates and maxilla's stress, strain, and displacement responses under occlusal forces of 125, 250, and 500 N/mm². RESULTS: This comparative analysis revealed slight variation in stress, strain, and displacement between the two models under varying loading conditions. Stress analysis indicated maximum stress concentrations at the vertical change in the left posterior area between maxillary segments, with the Ti6Al4V model exhibiting slightly higher stress values (187 MPa, 375 MPa, and 750 MPa) compared to the commercial titanium model (175 MPa, 351 MPa, and 702 MPa). Strain analysis showed that the commercial titanium model recorded higher strain values at the bending area of the l-shaped miniplate. Moreover, displacement analysis revealed a maximum of 3 mm in the left posterior maxilla, with the Ti6Al4V model demonstrating slightly lower displacement values under equivalent forces. CONCLUSION: The maximum stress, strain, and segment displacement of both fixation models were predominantly concentrated in the area of the gap between the maxillary segments. Notably, both fixation models exhibited remarkably close values, which can be attributed to the similar design of the fixation plates.

Cylindrical depth image based customized helical bone plate design.

Commercial straight metal plates have been generally used to fix fractured bones, but recently, the need for customized and helical metal plates has emerged. Customized metal plates are designed to fit the shape of the fracture area that is a 3D curved surface, making it more difficult than designing on a 2D plane. Helical plates are researched due to their advantage in avoiding blood vessel damage compared to commercially available straight metal plates. In this paper, we propose a novel algorithm to design a customized helical metal plate for the femur using cylindrical depth images and Boolean operations. We also present the results of 3D printing a metal plate designed using the proposed algorithm, and the shape matching is verified by calculating the minimum distance between the surface of the printed plate and the surface of the femur.

Combined anatomical reduction plate for quadrilateral acetabular fractures via a posterior approach: an anatomical-morphological study.

OBJECTIVE: To digitally measure the fixation trajectory of anatomical plates used in the combined reduction of quadrilateral acetabular fractures via the posterior approach, and to develop anatomical plates that align with the characteristics of the pelvis in the Chinese population. METHODS: Pelvic computed tomography (CT) data from 102 adult patients were collected at the Affiliated Hospital of Zunyi Medical University. This group included 51 males and 51 females, aged between 20 and 60 years. Using Mimics software (version 21.0), a three-dimensional model of each pelvic data point was reconstructed. The fixation path for the combined reset anatomical steel plate was drawn, where the curves on the fixation path were approximated as arcs. The radius of curvature and length of these curves were measured, and an anatomical steel plate was designed to best fit the pelvic structure. RESULTS: The combined anatomical reduction plate fixation system for quadrilateral acetabular fractures using a posterior approach consisted of two parts: a locking plate and a reduction plate. The posterior wall region (r2), ischial region (r3), quadrilateral region (r4), and bending region (r5), and the total length of the reduction plate were significantly smaller in females (P < 0.05). Similarly, the posterior wall region (R3), distal posterior wall region (R4), and the total length of the locking plate were significantly smaller in females (P < 0.05). Additionally, the anterior superior iliac spine side (r1) and the total length of the T-shaped auxiliary plate were significantly smaller in females (P < 0.05). The bending angle (< A) was also significantly smaller in females (P < 0.05). CONCLUSIONS: The pelvic surface structure is irregular and varies greatly among individuals.Compared to the traditional steel plate, The combined reduction anatomical plate designed in this study demonstrated high precision and improved conformity to the anatomical structure of the pelvis.

Design of osteosynthesis plate for detecting bone union using wire natural frequency.

We have developed a novel osteosynthesis plate with bone union detection using a wire's natural frequency (BUDWF) to provide the quantitative result of bone union detection. The concept for detecting bone union is measuring the rate of frequency change. The frequency is measured from sound generated from the wire attached to a modified plate. The plate is modified from a Syncera ADLER B0409.10 and attached with 0.3 mm diameter 316L stainless steel wire. The sound generation mechanism was created by PEEK and installed on the plate to generate the sound. The preliminary experiments were conducted on a Sawbones tibia composite mimic. We used the cut Sawbones to create fracture samples with a 0, 0.5, 1-, 2-, and 5-mm gap representing the fractured bone with different gap sizes and prepared uncut Sawbones as a union sample. These samples were tested five times, and the sound was recorded from a condenser microphone and analyzed. We found that the BUDWF can differentiate samples with a fracture gap above 2 mm from the union sample, as the differences in the rates of frequency change between samples with a fracture gap above 2 mm and union samples were statistically significant. However, there was a limitation that the BUDWF plate was still unable to differentiate the 0 mm fracture gap and the union sample in this study.

Benefits of Rib Fixation Utilizing Low-Cost Materials: A Randomized Pilot Trial.

INTRODUCTION: Surgical stabilization of rib fractures (SSRF) using standard rib plating systems has become a norm in developed countries. However, the procedure has not garnered much interest in low-middle-income countries, primarily because of the cost. METHODS: This was a single-center pilot randomized trial. Patients with severe rib fractures were randomized into two groups: SSRF and nonoperative management. SSRF arm patients underwent surgical fixation in addition to the tenets of nonoperative management. Low-cost materials like stainless steel wires and braided polyester sutures were used for fracture fixation. The primary outcome was to assess the duration of hospital stay. RESULTS: Twenty-two patients were randomized, 11 in each arm. Per-protocol analysis showed that the SSRF arm had significantly reduced duration of hospital stay (22.6 ± 19.1 d versus 7.9 ± 5.7 d, P value 0.031), serial pain scores at 48 h and 5 d (median score 5, IQR (3-6) versus median score 7, IQR (6.5-8), P value 0.004 at 48 h and median score 2 IQR (2-3) versus median score 7 IQR (4.5-7) P value 0.0005 at 5 d), significantly reduced need for injectable opioids (9.9 ± 3.8 mg versus 4.4 ± 3.4 mg, P value 0.003) and significantly more ventilator-free days (19.9 ± 8.7 d versus 26.4 ± 3.2 d, P value 0.04). There were no statistically significant differences in the total duration of ICU stay (median number of days 2, IQR 1-4.5 versus median number of days 7, IQR 1-14, P value 0.958), need for tracheostomy (36.4% versus 0%, P value 0.155), and pulmonary and pleural complications. CONCLUSIONS: SSRF with low-cost materials may provide benefits similar to standard rib plating systems and can be used safely in resource-poor settings.

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.