LCP Plate Research Articles

Low-profile locking-plate vs. the conventional AO system: early comparative results in wrist arthrodesis

Total wrist arthrodesis represents a reliable salvage procedure for severe painful conditions of the wrist. To date, wrist arthrodesis using a dorsal plate reaching from the distal radius to the third metacarpal is still recommended. A new implant (APTUS© 2.5 TriLock Wrist Fusion Plate, Medartis Suisse) that does not cross the third carpometacarpal joint (CMCJ-3) has been introduced recently. The purpose of this retrospective study was to compare both implants concerning early functional and clinical results. A total of 20 patients underwent total wrist arthrodesis [10, using the new APTUS© implant (APT); 10 using the Depuy-Synthes© LCP plates (AO)]. The postoperative control interval was 18.2 and 37.2months in APT and AO, respectively. Clinical assessment included functional parameters such as active range of motion (AROM) for pronation and supination, grip strength, and passive range of motion of the CMCJ-3. Additionally the DASH score and the Krimmer wrist score as well as pain levels at rest and under stress conditions were evaluated. All patients showed osseous healing without complications except one case of non-union in APT. There were no significant differences between both groups concerning grip strength, AROM of the wrist, pain levels, DASH- and Krimmer Score. APT showed a significantly increased passive range of motion of the CMCJ-3 compared to the unaffected contralateral side. The new implant shows similar functional results compared to the standard procedure. The main advantage of the new implant is the fact that no implant removal is necessary due to the unaffected CMCJ-3. Furthermore the mobility of the CMCJ slightly increased and showed positive impact on hand kinematics.

Functional analysis of distal one-third extra-articular femoral fracture managed with retrograde femur nailing system

Management of fractures has changed very much over the time. It has advanced from bamboo stick, POP to modern minimally invasive surgeries, to Robotic and distant operative techniques. In the modern world with the increase in speed and number of fast moving vehicles there is a great increase in number of RTA and number of polytrauma patients in causalities. The purpose of study is to achieve complete union with full functional ability of Limb as compared to earlier fixation method. New method of fixation of extra–articular distal one–third femur fracture i.e.: 1: 95° angled blade plate; 2: DCS; 3: Retrograde Nailing; 4: Distal Femur LCP Plating. Keywords: Extra-articular, Distal one-third, Femur fracture fixation using, Retrograde femur nailing system

Failure of the proximal locking compression plate in treatment of trochanteric femoral fractures

Treatment of proximal femoral fractures constantly draw attention of trauma surgeons because of their greater incidence. Last 10 years, shows the prevalence of intramedullary techniques, however plate osteosynthesis with proximal locking plate is still quite common in everyday practice.Objective: to conduct a retrospective analysis of treatment results of patients with proximal femoral fractures operated with locking proximal femoral plate and to identify the main mechanisms causing the high rate of unsatisfactory results. Methods: the study included 21 patients (mean age (65 ± 12) years) with fractures 31А2 and 31А3 according to the AO classification, that undergone osteosynthesis with proximal femoral LCP plate. Mean follow-up period was 7.5 months after surgery.Results: the absence of displacement and initial consolidation of the fracture was achieved in 17 of 21 patients (80.9 %). The average time of union was 6 months. Unsatisfactory results of treatment were observed in 4 cases (19.1 %). All of them were associated with fracture of the plate and nonunion of bone fragments. The fracture of the plate occurred at the level of the distal 7.3 mm locking hole in 8–9 months after the surgical intervention. In all this cases the revision surgery- implantation of proximal femoral antirotational nail (PFNA) was performed. In our opinion, such a large number of unsatisfactory results associated with excessive rigidity and an undesirable concentration of load. Conclusions: usage of proximal plates with angular stability of the screws is not always effective for the treatment of unstable fractures of the proximal femur. The high frequency of unsatisfactory results that required re-osteosynthesis with the PFNA, indicates the need for careful preoperative planning and selection of stabilization method for proximal femoral fracture treatment.

The "FraMo" System: A New Mini-Invasive Technique in the Treatment of Proximal Humerus Fractures.

Fractures of the proximal humerus are relatively common injuries in adults accounting for 5% of fractures. Nowadays the most common technique used is open reduction internal fixation with LCP plates. The risks associated with open reduction internal fixation had led us to develop and apply a "hybrid" system, which is based on external fixation and closed surgery principles. This system is capable of stabilize up to 4 fragment fractures on different planes while conferring a strong enough fixation to maintain fracture reduction while allowing the patient to perform passive and active movement since the first day following the surgery. Our study group started on November 2009 until December 2015 and consisted of 118 patients with a mean age of 68.84±10.52 years for females (76) and 65.62±12.56 for males (44). Patients were classified according to the AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma association) Classification. In a few patients we performed mini lateral accesses to allow reduction of the humeral head and greater tuberosity. Shoulder mobilization was initiated from the first day following surgery. The external fixator was removed at 5 weeks with successive check-ups at 3, 6, and 12 months. The majority of type B and type C1 fractures had almost a complete functional recovery. Patients also, especially in the elderly, reported a good quality of life without pain during any range of motion. Our group of patients, after removal of the apparatus at 5 weeks following the surgery, had a mean articular range of motion with active abduction of 90 degrees and about 100 degrees with passive abduction. Postoperative CS scores at 12 months follow-up was 75,47±8.02. In addition there was also significant (P<0.05) improvement between preoperative and postoperative visual analog scale measurements (in cm), 7.67±2.70 and 1.71±2.08, respectively. This technique has shown good functional results with reduced surgical risks and complications that are typical of open reduction surgical fixation of proximal humerus fractures, is quick in execution and minimally invasive. Given the very good results of the study of this new external fixation technique has shown to be a viable option for the treatment of proximal humerus fractures.

Study of surgical management by internal fixation of distal tibia fractures

The purpose of this study is to evaluate the effectiveness, functional results and complications following surgical internal fixation of comminuted distal tibia fractures with supracutaneous LCP plate. In this study 20 patients of fresh distal tibia fractures treated surgically following internal fixation by LCP plating, studied between January 2017 to March 2018. High energy trauma (RTA) accounts for 70% of cases, and according to AOOTA classification 43A type of fracture pattern seen in majority of cases in our study. Surgeries were performed within 4-7 days average. All cases treated surgically by supracutaneous LCP plating, all the fractures united with a union rate of 92%. Radiological union was possible in 17.5 weeks, weight bearing started from 12 weeks, early ankle stiffness noted in 1% of cases which was overcome by good physiotherapy and full ankle motion observed in 90% patients. There were one case of superficial infections, one patient with deep infection got treated with antibiotics, and 1 patient with screw loosening had tightened with hexagonal screw driver. Functional results according to criteria by Jing Wei Zhang et al and Sven A.F. Tulner et al 60% of patients achieved excellent results, 30% patients’ shows good results, and fair result obtained in 10% patients.

Functional outcome of surgical management in schatzker type V, VI tibial plateau fractures with locking compression plate

Tibial plateau fractures are one of the commonest intra articular fractures. Results from indirect coronal or direct axial compressive forces. Among Tibial plateau fractures, Schatzker type V and VI tibial fractures are complex injuries, usually treated with open reduction and internal fixation (ORIF) using LCP plates.AIM: This study was done to determine functional outcome and the complications of Schatzker V and VI tibial plateau fractures treated with LCP plates with a regular follow-up of 18 months.Materials and Methods: Total 30 cases of tibial plateau fracture type V and VI treated with dual plating were studied from FEBRUARY 2017 to NOVEMBER 2018 in Sanjay Gandhi Institute of trauma and orthopaedics, Bangalore. The follow up duration ranged from 6 months to 15 months. The patients were operated through an anterolateral approach for lateral plate and a medial column plate was put through a minimally invasive medial approach or an open posteromedial approach.Results: Total 30 patients were evaluated postoperatively thoroughly for functional and radiological outcomes by Modified Rasmussen Assessment criteria which showed 17 patients (56.7%) had excellent, 8 patients (26.7%) had good,3 patients (10%) had fair and 2 patients (6.7%) had poor outcomeConclusion: We concluded open reduction and internal fixation of high-energy tibial plateau fractures with LCP excellent to good functional outcome with minimal soft tissue complications. Thus, a minimally invasive approach should be used which helps in preventing soft tissue problems and helps in early wound healing. Fixation done by Dual plating is important for early mobilization of knee joint. Early mobilization leads to better range of movements and thereby better functional outcome.

COMPARISON OF LCP AND INTRAMEDULLARY NAIL OSTEOSYNTHESIS IN CALCANEAL FRACTURES.

ABSTRACTObjective:This study compared groups of patients with calcaneal fractures of Sanders types II and III. One group was treated with ORIF using an LCP (plate), while the second was treated with a minimally invasive method using a C-Nail.Methods:The study included 217 patients in the ORIF group and 19 patients in the minimally invasive nail osteosynthesis group.Results:In the LCP group, the outcomes were excellent for 35.7% of the patients; good, 38.9%; satisfactory, 19.7%; and poor, 5.7%. In the C-Nail group, the outcomes were excellent for 36.9% of the patients; good; 31.6%; satisfactory, 21%; and poor, 10.2%. The mean values of the restoration of Böhler's angle from post-injury were 6.8° to 32.3° in the LCP group and 7.1° to 33.3° in the C-Nail group. After 12 months, there was only a minimal decrease in Böhler's angle to 29.2° in both the LCP and C-Nail groups.Conclusion:The outcomes obtained with C-Nail fixation are statistically identical to those obtained with LCP fixation. We conclude that osteosynthesis with a C-Nail is suitable as the first-choice treatment for Sanders types II and III fractures. Level of evidence IV, retrospective observational study.

Minimally invasive percutaneous plate osteosynthesis (MIPPO) in distal tibia fractures-retrospective functional and radiological outcome analysis among rural population

Background: Distal tibia fractures are one of the common fractures and results from indirect coronal or direct axial compression forces. These fractures encompass many and varied fracture configurations that involve medial, lateral, or both sides with many degrees of articular depressions and displacements. Each fracture type has its own characteristic morphology and response to the treatment. Need for Study: Despite many advances in the care of these fractures, distal tibia fractures continue to be a difficult surgical problem. A survey of literatures indicates that many authors report nearly 50% satisfactory results with either closed or operative methods of treatment. In view of these considerations present study was taken up. Aim of Study: The aim of our study was to retrospectively analyze the result of distal tibia fractures managed with LCP plating, the effect on ankle joint function, fracture union, operative difficulties encountered and the incidence of complications in the study population. Materials & Methods: This study is a retrospective study of 30 cases who were admitted and operated in the dept. of orthopedics attached to R. L. Jalappa hospital between January 2011-December 2015. Inclusion criteria is skeletally mature patients with closed and Gustilo /Anderson open grade I, II, IIIA distal tibia fractures. Exclusion criteria is patients with grade IIIB and IIIC of Gustilo Anderson fractures, patients with other ipsilateral limb fractures, pelvic fractures, Neurovascular injury. Follow-up is based clinically and using American Orthopaedic Foot and Ankle Score (AOFAS).Results: Results were analyzed with reference to anatomical reduction achieved, radiological union and ankle functional range of movements. Statistical analysis will be carried out using SPSS version 20(IBM, Chicago, USA).

Results of surgical treatment of intertrochanteric and trochanteric fractures in eldery patients

Intertrochateric and trochanteric include 52 % out of all femo­ral fractures. More than 91 % of these fractures occur in peo­ple 65 years of age and older. Despite the variety of implants, the number of unsatisfactory treatment outcomes remains high. The fatal outcome due to these fractures is 12–19 % and in­creases with age.Objective: to evaluate the long-term results of metalloesteosynthesis and hip replacement in an improved method in elderly people with intertrochateric and trochanteric lfemoral fractures.Methods: 156 patients aged 61 to 94 years were examined. Joint replacement was performed in 51 patients (study group), metalloesteosynthesis with PFN, DHS, angular and LCP-plates — 105 (control). The Harris score was used to analyze long-term functional results.Results: satisfactory functional results of the treatment were obtained after the PFN and DHS — (75.13 ± 10.14) and (72.83 ± 17.36) respectively. When using angular and LCP plates, treatment was unsatis­factory — (55.71 ± 19.28) and (67.67 ± 19.73) points, respec­tively. In the group of total cement endoprosthesis, the results were evaluated as excellent — (93.0 ± 4.33) points; subtotal bipolar — good (86.53 ± 9.7) points; subtotal monopolar — satisfactory (78.23 ± 7.92) points. The total score of excellent and good results in patients in the study group was 76.47 %, the control group — 35.48 %, the poor — 5.88 % and 64.58 % respectively.Conclusion: hip joint replacement in patients over 61 years of age with intertrochateric and trochanteric fractures of the femur gives the best long-term functional results com­pared to the metalloesteosynthesis.

Why a surgically treated humeral shaft fracture became a nonunion: review of 11 years in two trauma centers

The aim of this study was to evaluate nonunion causes of surgically treated humeral shaft fractures in two different trauma centers. A total of 327 cases of humeral shaft fractures were treated in 11years in two trauma centers. We retrospectively reviewed in detail some factors in order to understand the reasons for nonunion: (1) fracture type, according to the AO classification, (2) grade of open fracture, according to Gustilo-Anderson, (3) timing, (4) reduction and (5) fixation. We observed 19 nonunions, 10 women and 9 men, with an average age of 57years. Fractures were 1 A1 case, 2 A2 cases, 4 B2 cases, 6 B3 cases, 2 C1 cases, 1 C2 case and 3 C3 cases. Three cases had a simple fracture with two fragments; all the other were comminuted. Fifteen cases were closed, four open. The major criticalities observed were fracture comminution, exposure, unstable fixation and bone resorption. All 19 patients with nonunion underwent surgical fixation with compression plate and frozen cortical bone graft. A 4.5 LCP plate was used in 17 cases. The remaining 2 cases had an anatomical site-specific proximal humeral 3.5-mm LCP plate (Synthes, Paoli, PA, USA). In 17 patients, the nonunion healed: 15 cases treated with a 4.5 straight plate, and 2 cases with an anatomical site-specific proximal humeral 3.5mm LCP plate, at a mean of 5months. In 2 cases, consolidation was not reached. We believe that humeral diaphyseal fractures should be treated surgically to avoid many complications. Our retrospective analysis indicates that factors that lead to a fixation failure are fracture comminution, open fracture, unstable fixation. The 19 nonunions treated with compression plating and frozen bone graft demonstrated consolidation in almost 90% of the cases.

Bone healing is achievable despite extensive wound dehiscence and wide plate and screws exposure in children

BackgroundExtensive wound dehiscence and wide plate and screw exposure in the early weeks following orthopaedic surgery in children is usually managed either by extensive debridement, lavage and secondary closure or hardware removal and external fixation. PatientsThree children with LCP plate and screws exposure were managed by simple repetitive debridement and local wound care without any IV antibiotics, nor secondary closure or hardware removal. All three cases occurred in the tibia, one following tibial osteotomy in lateral hemimelia with a long history of previous surgeries, one following wide excision of a tibial Ewing sarcoma with chemo- and radiotherapy, and the third following wide excision of a 12cm necrotic tibial segment due to chronic osteomyelitis. Bone healing was uneventful in 2 cases and was in progress in the case with the Ewing sarcoma. Plate and screws were removed in all cases, following an obvious bone healing in 2 cases, and forced by the need for chemotherapy due to the presence of lung metastases in the third case. Spontaneous soft tissue healing occurred thereafter. ConclusionA stable fixation may lead to a good bone healing despite an extensive wound dehiscence and a wide plate and screws exposure with just a proper local wound care and without any major additional surgery. Level of evidenceLevel IV.

Comparative biomechanical analysis of three implants used in bicondylar tibial fractures.

Currently, the most difficult-to-treat tibial plateau fractures are complex, comminuted fractures, which result from high-energy trauma. The anatomical reconstruction of the articular surface and the preservation of the soft tissue envelope are required for agood functional result. The aim of this study is to perform abiomechanical evaluation of three constructs used in the treatment of bicondylar fractures: the L‑shaped plate, the LCP locking plate, and the hybrid external fixator. We used 30experimental models divided into three study groups. There were ten models for each type of implant. The best biomechanical behavior was found with the LCP locking plate, which showed minimal deformation upon cyclic loading, followed by the hybrid external fixator. The LCP plate is the optimal implant for the stabilization of Schatzker type V tibial plateau fractures, with low rates of degradation for the implant and the bone-implant assembly.

Outcome after internal fixation of intraarticular distal humerus (AO type B & C) fractures: Preliminary results with anatomical distal humerus LCP system.

The treatment of intraarticular fractures of the distal humerus is challenging and involves the risk of complications and bad functional results. Anatomical and stable internal fixation with early postoperative mobilization is expected to improve the functional outcomes. The objective of this study was to evaluate the functional and radiological results, along with the complications associated, of open reduction and internal fixation using precontoured anatomical locking LCP plate system for intraarticular distal humerus fractures in adult patients. This prospective study consist of 31 patients with a mean age of 41.2 years (range 19-62) were treated with open reduction and angular stable internal fixation. All underwent posterior transolecranon surgical approach. Mean follow-up to the final interview was 10 months (from 6 to 20 months). All operated patients were available at the time of last followup. AO classification showed 26 C-fractures (9*13C 1, 12*13C2,5* 13C3) and 5 B-fracture (1* 13B1,1* 13B2,3* 13B3). There were 25 closed fractures and 6 open grade 1 fractures. The clinical followup using Mayo elbow performance score (MEPS) and radiographic follow up with elbow anterior-posterior and lateral view X-rays were performed postoperatively. The mean MEPS was 87.9 points out of 100 (range 55-100) with 61% Excellent, 29% good and 10% fair and poor scores. Mean elbow flexion of 115.8° (range 85°-150°). The mean deficit in extension was 19° (range 5°-35°). All olecranon osteotomy were united .Nonunion of distal humerus fracture occurred in 2 cases. Other complications were hardware prominence in 3 cases, superficial infection in 4 cases and Ulnar nerve neuropraxia in 1 case which was recovered uneventfully. Revision surgery was not required in any complication. Open reduction and internal fixation with precontoured distal humerus anatomical locking plate system is a good method of treatment for complex Supra- intercondylar fracture of distal humerus with good functional outcome and low rates of complications. Even though early results are promising, longer term investigations and larger patient groups are necessary to confirm the presented data.

Outcome of surgical treatment of proximal humerał fracture

Glenohumeral joint movement dysfunction, often caused by proximal humeral fracture, limits daily activity. Proximal fracture of the humerus is a common injury which constitutes 5.7% of all fractures in trauma patients. The aim of the study was the retrospective evaluation of results of surgical treatment of proximal humeral fracture in accordance to fracture type and applied treatment. The study group consisted of 70 patients who had undergone surgery due to proximal humeral fracture. The mean age in the study group was 55.2 years. The patients were classified according to the AO/ASIF system, based on the preoperative X-ray in comparison to the operative X-ray image. The patients were treated with five methods (ORIF – LCP-type plate, ORIF – AO-type plate, ORIF – AO screw(s), CRIF – intramedullary nailing, CRIF – „K” wires). The average time of follow-up amounted to 19.4 months. The function of the glenohumeral joint was assessed after surgery applying the Constant-Murley scale. The analysis of treatment outcomes showed that in patients operated on for proximal humeral fracture type A and B, the percentage of results described as very good and good was comparable and amounted to approximately 50%. In the smallest group of patients with the most complex type C fractures, a good and very good result was observed only in 14.29% of the subjects. The analysis did not show statistically significant differences in treatment results (p>0.05). Multiple comparisons showed that regardless of the fracture type, patients received a similar score on the Constant-Murley scale. Osteosynthesis using LCP plates and angular stabile screws does not improve the treatment outcome in any type of the proximal humeral fracture. However, LCP plates and angular stable screws are used as a standard management for the most severe cases of proximal humeral fracture. Because of a many available treatment techniques, qualification for a particular treatment method should be considered individually for every patient.

Early Outcomes of Humeral Non-Union Treatment with Intramedullary Strut Grafting and Long LCP Plating: Case Reports after Failed Ilizarov (Ring) Fixation

Humeral diaphysis non-union is extremely difficult complication for the patients and orthopedic surgeons as well. Number of methods of managing atrophic humeral nonunion have been suggested, and each has its drawbacks. In current literature, there are no articles regarding treatment of humeral non-union after failed Ilizarov (ring) fixation surgery. This article presents early results of two cases of surgically treated fibular (intramedullar) strut graft and long LCP (PHILOS) plate. It is shown that fibular strut auto-graft bridging non-union site in conjunction with locked plating could be high potency healing material in osteoporotic atrophic humeral non-union. This technique need future and long term follow up analysis with potential use in different long bone non-union sites.

A Unique Modality for treating Open Supracondylar fracture Femur with Bone Loss. (Gustillo Anderson – 3B)

Background: Various treatment modalities are used for the treatment of GA-3B injury, yet determining the choice of treatment is difficult. We report fifteen such cases, of which twelve were treated with DCS and 950 plate and three with LCP because of minimal bone stock at the distal end (condyles) along with non- vascularised dual ipsilateral fibular strut graft and cancellous bone grafts from iliac crest. Materials and Methods: We performed this study from 2000 – 2014. We studied Total 1176 cases of supracondylar fracture femur of which 15 were of type GA-3B. The study consisted of eight males and seven females, eleven were right sided and four left sided. Fifteen patients underwent surgery (twelve were treated with DCS and 950 plate, three with LCP plate) with dual ipsilateral fibular strut graft and cancellous bone graft from iliac crest. Thirteen had functional range of movement (avg 0-1170), one had range of movement 0-70o and one had range of movement 0-15o at knee joint. Fractures united in all fifteen patients with average period of union twelve weeks and all returned to previous work. Immediate treatment consisted of debridement, primary closure, proximal tibial skeletal traction and broad spectrum i/v antibiotics. Once the wound was healed, surgery (open reduction internal fixation (ORIF) with plating with ipsilateral dual fibular strut grafts and cancellous graft) was performed. Result and Conclusion: We performed two-stage surgery in all the cases. First in the form of debridement and skeletal traction and secondly, definitive fixation was carried out. The current study demonstrated that ORIF with (DCS and 950 / LCP) plate with dual ipsilateral non-vascularised fibular strut graft and cancellous bone grafts from iliac crest is a good modality for open supracondylar fracture femur with bone loss with good results and functional range of movement. This is a small study with favorable results. However, it requires large study group to prove this technique beneficial for treating such fractures. Keywords: GA-3B, bone loss, fibular strut graft, iliac graft, 95 DCS, LCP.

Acute compartment treatment results of distal humerał fractures

In spite of the fact that distal humeral fractures constitute only 2% of all fractures, they are often the cause of significant elbow joint mobility restrictions, which may disturb proper functioning of the upper limb to a considerable extent. The aim of the study was to evaluate the results of distal humeral fractures treatment with particular focus on type-C fractures according to the AO/ASIF classification. The material of the study was composed of 60 patients between 25 and 82 years of age, treated in the Clinical Department of Orthopaedics and Traumatology of the University Hospital No. 1 in Bydgoszcz in the years 2009-2011. The patients were subject to operative treatment with the use of four techniques (ORIF – LCP-type plate, ORIF – AO-type plate, ORIF – AO screw(s), CRIF – K-wires). The average patient observation period was 18.7 months (±5.9). Patients under the study were subject to observation and functioning of the elbow joint was evaluated after surgery according to the MEPI score. Patients suffering from type-B fractures recorded better treatment results than those suffering from type-C fractures: p = 0.046. The differences between type A and types B and C have been statistically insignificant: p > 0.05. No impact of any type of fixation on the results of treatment has been recorded. In type-C group of fractures according to AO/ASIF, statistical analysis has shown advantage to the benefit of fixation with dedicated anatomical LCP plates and AO plates (p = 0.046). In this group, operative treatment using the aforesaid methods achieved good and excellent results (MEPI ≥ 75 points) in 81% of cases. Good treatment results depend on proper patient qualification for a particular surgical procedure and may be achieved also for type-C intra-articular fractures, provided that anatomical reduction of articular surface and stable plate osteosynthesis are obtained. In other types of distal humeral fractures (types A and B) similar treatment results may be obtained using different operative treatment techniques.

A study on the mechanical characteristics of the EBM-printed Ti-6Al-4V LCP plates in vitro.

PurposeThe electron beam melting (EBM) Ti-6Al-4V material technology has been developed over a short time period. It was introduced through a research to develop Ti-6Al-4V implants for patients, but EBM printed locking compression plates have not been used for clinical implants. The main purpose of this study is to find whether the EBM Ti-6Al-4V plate suit for clinical implants.MethodsFirst, we scanned an AO-locking compression plate (LCP) and printed LCP samples using EBM. Next, we evaluated the EBM plate surface roughness through optical microscopy as well as the LCP and EBM plates’ mechanical characteristics using the ASTM standard, which is commonly used to test the mechanical properties of bone plates subject to bending. Each sample was examined using a single-cycle four-point bending test and hardness testing to acquire data on bending stiffness, bending strength, bending structural stiffness, and hardness.ResultsThe results show significant differences in bending stiffness, bending strength, bending structural stiffness, and hardness between the samples using EBM and the original LCP plates. The EBM-printed samples’ surface roughness was 0.49 ± 0.02 μm. The mean hardness of the LCP sample was 266.67 HV10 ± 5.8, and the EBM-printed sample mean hardness was 341.1 HV10 ± 1.93. The EBM samples’ bending stiffness was 87.67%, which is greater than using the LCP plates’; and the bending strength was 190.7% greater, the bending structural stiffness was 73.2% greater, and the hardness was 27.9% greater.ConclusionsThe results show that the EBM plates’ general mechanical strength was significantly greater than the LCP plates. An EBM plate is advantageous for clinical implants because it can be customized with great potential for improvement.

Plate selection for fixation of extra-articular distal humerus fractures: A biomechanical comparison of three different implants

Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs.Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy.In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens.Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater bending stiffness, torsional stiffness, and yield strength than a single 3.5mm LCP plate for osteotomies created 80mm from the trochlea. At the more distal osteotomy, dual plating was biomechanically superior. Our results suggest that single posterolateral column fixation of extra-articular humerus fractures is appropriate for more proximal fractures but that dual plate fixation is superior for more distal fractures.

Structure determination from in situ diffraction with the Rigaku PlateMate

As crystallographers face increasing problems with crystallizing new proteins, in-situ screening in crystallization trays at room temperature is experiencing a renaissance. It saves a lot of time when screening large numbers of crystallization hits and it helps avoid crystal damage caused by human manipulation error (harsh manual handling, bad freezing) or changes in crystal properties (dehydration, wrong cryo-conditions). In certain cases, it is also possible to go beyond screening and collect enough data for structure solution, especially on an X-ray home source where a less intense beam helps minimize the devastations of radiation damage occurring at room temperature. The Rigaku PlateMate has proved itself as an efficient and easy-to-use in-situ screening tool on the field for the past two years. It is as easily mounted on a goniometer as a regular goniometer head and thanks to a plate adapter with SBS footprints, it accommodates most 96-wells plate types, from sitting and hanging drop to LCP plates. In addition, thanks to its narrow dimensions and aided by software to prevent collisions with the detector and the crystal viewing camera, the PlateMate can be used to easily collect data from crystals in situ. In this work, we present structure solution results obtained from data collected with the PlateMate on crystals from various proteins (native crystals or containing gold or iodine) and using one or multiple crystals to make up a complete data set.