Locking Plate System Research Articles

A prospective study to evaluate functional results of PHILOS locking plate system in management of proximal humerus fractures in adults

<p class="abstract"><strong>Background:</strong> Various management options are available for management of proximal humerus fractures where PHILOS plating is one of them. But data available in literature on its use and efficacy in management of all types of proximal humerus fractures is still dicey. So, we through our study attempted to grow our knowledge regarding its functional results, complication rates, etc. for use in coming future.</p><p class="abstract"><strong>Methods:</strong> 30 patients with proximal humerus fractures classified on the basis of Neer’s classification were included in study who were operated from 2018 to 2020 at our institute. These patients were operated by PHILOS locking plate system with either delto-pectoral or trans-deltoid approach and they are followed up at regular intervals to assess them clinicoradiologicallly and functionally by Neer’s criteria.<strong></strong></p><p class="abstract"><strong>Results:</strong> In our study we found maximum incidence of these fracture between age group of 40-80 years (66.66%) with male to female ratio of 2:1 with 19 patients having left sided and 11 patients having right sided proximal humerus fracture. Complications were found in 11 patients (36.67%). Functional evaluation was carried out using Neer’s criteria at final follow up which came to excellent results in 3, satisfactory in 18, unsatisfactory in 7 and failure in 2 patients. Average time of fracture union was 12.62 weeks.</p><p class="abstract"><strong>Conclusions:</strong> PHILOS locking plate system serves good purpose in management of fractures of proximal humerus but requires trained faculty to do this operation who has detailed knowledge about shoulder anatomy and mechanism of injury to reduce complications associated with this type of modality.</p>

Infection rate treating radial and ulnar fractures using bone plate fixation without antibiotic prophylaxis.

To evaluate the effectiveness and complication rate of a 1.5- and 2.0-mm titanium locking plate for the treatment of radial and ulnar fractures in small dog breeds and cats without peri-operative antibiotic prophylaxis in a prospective case series. Medical records and radiographs of closed radial and ulnar fractures treated using internal fixation with a 1.5- or 2.0-mm titanium locking plate without antibiotic prophylaxis were collected prospectively. Patients were clinically followed up until radiographical fracture healing was complete. Thirty-two fractures in small breed dogs and cats with an average bodyweight of 3.9kg met the inclusion criteria. The follow-up time radiographically and clinically was 4-35 weeks. All fractures showed radiographical fracture union, and all patients had a good clinical outcome. The superficial infection rate in this case series was 0%; the deep infection rate involving the implant/bone was 3.1%. The novel 1.5- and 2.0-mm titanium locking plate system was successfully used to treat simple closed radial and ulnar fractures in small breed dogs and cats without peri-operative antibiotic prophylaxis, resulting in good clinical outcome and a low infection rate.

Comparison of 24-Month Outcomes After Treatment for Distal Radius Fracture

Distal radius fractures (DRFs) are common injuries among older adults and can result in substantial disability. Current evidence regarding long-term outcomes in older adults is scarce. To compare outcomes across treatment groups at 24 months among adults with DRFs who participated in the WRIST trial. The Wrist and Radius Injury Surgical Trial (WRIST) randomized, international, multicenter trial was conducted from April 1, 2012, through December 31, 2016. Participants were adults aged 60 years or older with isolated, unstable DRFs at 24 health systems in the US, Canada, and Singapore. Data analysis was performed from March 2019 to March 2021. Participants were randomized to open reduction and volar locking plate system (VLPS), external fixation with or without supplementary pinning (EFP), and percutaneous pinning (CRPP). The remaining participants chose closed reduction and casting. The primary outcome was the 24-month Michigan Hand Outcomes Questionnaire (MHQ) summary score. Secondary outcomes were scores on the MHQ subdomains hand strength and wrist motion. A total of 304 adults were recruited for the study, and 187 were randomized to undergo surgery, 65 to VLPS, 64 to EFP, and 58 to CRPP; 117 participants opted for closed reduction and casting. Assessments were completed at 24 months for 182 participants (160 women [87.9%]; mean [SD] age, 70.1 [8.5] years). Mean MHQ summary scores at 24 months were 88 (95% CI, 83-92) for VLPS, 83 (95% CI, 78-88) for EFP, 85 (95% CI, 79-90) for CRPP, and 85 (95% CI, 79-90) for casting, with no clinically meaningful difference across groups after adjusting for covariates (χ23 = 1.44; P = .70). Pain scores also did not differ across groups at 24 months (χ23 = 2.64; P = .45). MHQ summary scores changed from 82 (95% CI, 80-85) to 85 (95% CI, 83-88) (P = .12) between 12 and 24 months across groups. The rate of malunion was higher in the casting group (26 participants [59.1%]) than in the other groups (4 participants [8.0%] for VLPS, 8 participants [17.0%] for EFP, and 4 participants [9.8%] for CRPP; χ23 = 43.6; P < .001), but malunion was not associated with the 24-month outcome difference across groups. The study did not find clinically meaningful patient-reported outcome differences 24 months after injury across treatment groups, with little change between 12 and 24 months. These findings suggest that long-term outcomes need not necessarily be considered in deciding between treatment options. Patient needs and recovery goals that fit to relative risks and benefits of each treatment type will be more valuable in treatment decision-making. ClinicalTrials.gov Identifier: NCT01589692.

A comparison between the femoral neck system and other implants for elderly patients with femoral neck fracture: A preliminary report of a newly developed implant

BackgroundFemoral neck system (FNS) is an implant for patients with femoral neck fracture. It has superior angular and rotatory stability; it is less invasive because of its established locking plate system. To the best of our knowledge, there are no studies yet concerning the clinical outcomes of elderly patients with femoral neck fracture who have been treated using the FNS. MethodsData of patients with femoral neck fracture aged >65 years and who had undergone internal fixation with the FNS and other implants were retrospectively analyzed in this study. The follow-up period was a minimum of six months between January 2006 and November 2020. In total, 52 patients were included in the clinical evaluations, using the FNS (group F) was 25 and using other implants (group O) was 27. Outcome measurements were surgical time, the amount of blood loss, union rate and the cases that underwent reoperation. ResultsThe average surgical time in the group F was 42 ± 13 min (range: 26–83 min) and was shorter than that in the group O (53 ± 21 min, range: 13–111 min, P = 0.032). The average blood loss in the group F was calculated to 36 ± 25 g (range: 0–91 g), while it was 41 ± 40 g (range: 0–169 g) in group O. No significant difference among the groups. The union rate of the group F was 100%, and the reoperation rate of the group F was significantly less than that of the group O (0% vs 22%, P = 0.023). ConclusionInternal fixation using the FNS can be an alternative option with shorter surgical time and lower reoperation rate for elderly patients with femoral neck fracture.

Triplanar Correction for First Metatarsophalangeal Fusion

Successful deformity correction utilizing first metatarsophalangeal (MTP) fusion for hallux valgus with concomitant degenerative changes of the first MTP joint is well documented. Currently, there is limited discussion in the literature focusing on triplanar correction of the first MTP arthrodesis. Presented is a novel approach for triplane correction and fusion of the first MTP joint utilizing a biplanar locked plating system.

Short-term outcomes of 59 dogs treated for ilial body fractures with locking or non-locking plates.

To determine the influence of plating systems on the clinical outcomes in dogs treated for ilial fractures. Retrospective study. Fifty-nine dogs (63 hemipelves). Radiographs and medical records of dogs with ilial fractures presented to Iowa State University between 2003 and 2019 were reviewed. After fracture reduction, fractures were fixed with a locking plate system (LPS) or non-locking plate system (NLS). Perioperative, long-term complications, and follow-up data were recorded. The frequency of implant failure and pelvic collapse were compared using a logistic and linear regression analysis, respectively. Where the univariate test was statistically significant, a multivariate analysis across categories was performed to identify statistically different categories. LPS and NLS implants were used in 25/63 and 38/63 hemipelves, respectively. Median follow-up time was 8 weeks (3-624 weeks). Implant failure occurred in 18/63 (29%) of fracture repairs, consisting of 17 with NLS and 1 with LPS. Revision surgery was recommended in five cases of implant failure, all with NLS. The probability of implant failure was higher when fractures were fixed with NLS (p=.0056). All other variables evaluated did not seem to influence outcome measures. The variable with the most influence on the outcomes of dogs treated for ilial fractures consisted of the fixation method (NLS vs. LPS). Fractures repaired with NLS were nearly 20 times more likely to fail than those repaired with LPS. Surgeons should consider repairing ilial body fractures in dogs with LPS to reduce the risk of short-term implant failure.

Outcome after polyaxial locking plate osteosynthesis in proximal tibia fractures: a prospective clinical trial

BackgroundThe aim of this study was to evaluate the clinical and/or radiologic outcome using different polyaxial locking plates for the treatment of proximal tibia fractures, the Non-Contact-Briding plate (NCB-PT®) by Zimmer or the Variable Angle Locking Compression Plate (VA-LCP®) by Synthes.MethodsThis study enrolled 28 patients with proximal tibia fractures (AO/ OTA 41 B-C) and indication for locking plate osteosynthesis. All patients were treated with a polyaxial locking plate system. Depending on the fracture morphology, patients were either treated with a NCB-PT® or VA-LCP®. The implant was chosen according to the surgeon’s experience and preference, in case of a higher degree of comminution the tendency was observed to use the NCB-PT® plate. After a time interval of 12 months postoperative we conducted clinical (e.g.e.g.exempli gratia range of motion, the Rasmussen score) and radiological (e.g. primary/secondary loss of reduction) follow-ups.ResultsPatients provided with the NCB-PT® (9 patients) showed longer operation time, use of longer implants, longer interval from injury to surgery and lower clinical scores after the 12 months follow-up compared with the VA-LCP® group (19 patients). Interestingly, the results showed no significant differences regarding the clinical and radiologic outcome.ConclusionsThe small number of patients as well as the heterogeneity of fractures constitute a limitation of this study. Nevertheless, the differentiated use of implants is associated with comparable clinical and radiological outcomes. This trial emphasizes the need for further prospective randomised trials with higher patient numbers.Trial registrationRetrospectively registered 21.12.2020. Registration number NCT04680247.

Is early full weight bearing safe following locking plate ORIF of distal fibula fractures?

BackgroundIn the modern western world appraisal of economical points such as treatment and disability after trauma present a financial burden. In this context open reduction internal fixation techniques allowing for early full weight bearing might not only improve the clinical outcome but also shorten the period of disability in working life. The aim of the study was to analyze whether ORIF of ankle fractures using either a standard semitubular plate or a new polyaxial locking plate system result in a better clinical outcome.MethodsIn this prospective study, all patients with distal fibula fractures (AO 44 B1.1, B1.2, B1.3), with indication for surgery were included. Patients were randomized to either the DePuy Synthes® one-third semitubular plate (Group I) or NEWCLIP TECHNICS, Active Ankle® polyaxial locking plate (Group II). Primary outcome parameter was function of the ankle joint, assessed by the Olerud and Molander ankle score, Foot and Ankle outcome score and Karlsson and Peterson Scoring System for Ankle function. Secondary outcome parameter were postoperative complications. Superficial wound infection, delayed wound healing, mechanically prominent implant, skin irritations were considered as minor and deep wound infection, material loosening, loss of reduction were regarded as major complications requiring revision surgery. Clinical and radiological follow-up were performed 6 and 12 weeks, 6 months and 1 year postoperatively.ResultsFifty-two patients (31 W/21 M) with a mean age of 43 yrs. (range 22–64 yrs.) were enrolled. Seven patients (13.5%) were excluded, so that 45 patients were available for follow up. Twenty-five patients were treated with DePuy Synthes® one-third semitubular plate (55.6%; group I) while 20 patients received an anatomically preformed polyaxial locking plate (44.4%, group II). Four minor complications occurred in Group I (16%) compared to two minor complications in group II (10%). Significant better clinical results regarding OMAS (p < 0.02, < 0.04), KPSS (p < 0.04) and FAOS (p < 0.02, < 0.03) were observed 6 and 12 weeks after surgery in group II.ConclusionsThe results of the presented study demonstrate a significant better clinical functional outcome in the early postoperative follow-up in patients treated with a polyaxial locking plate. Furthermore, our data show that ORIF using polyaxial locking plates in combination with an early postoperative weight bearing presents a safe, stable treatment option for ankle fractures so that patients benefit especially in the early stages of recovery.Trial registrationRegistered 20 April 2020, retrospectively on ClinicalTrails.gov (NCT04370561).

Treatment of forearm diaphyseal non-union: Autologous iliac corticocancellous bone graft and locking plate fixation

IntroductionStudies conducted on forearm bone diaphysis non-union are limited due to the rarity of this condition. The present study aimed to evaluate the outcome of our technique using autologous iliac corticocancellous bone graft fixed by locking plate system for the forearm bone diaphyseal non-union without infection. Patients and methodsWe treated eight patients with non-union of radial or ulnar shaft fracture (four men, four women) aged 38 years (range: 18–52 years) on average. The average follow-up period was 18 months (range: 12–24 months). In our technique, we applied the locking plate to the diaphyseal bone fragment, before grafting the bone block to the non-union site. After excision of sclerotic ununited bone, the autologous iliac corticocancellous bone was grafted to the defect and fixed with single locking screw. Pain, grip strength, and disabilities of the arm, shoulder, and hand (DASH) score were measured and compared before and 12 months after the surgery. Radiographs were taken at each follow-up, and the time of bony union was determined. ResultsThe mean time to radiological union was 4.2 months (range: 3–6 months), and bony union was achieved in all cases within 6 months. All measured values, visual analog scale, DASH score, and grip strength, were significantly improved at 12 months after surgery (p<0.05). No minor/major complications including infection, non-union, or malunion were reported. ConclusionsLocking compression plate fixation and autologous iliac corticocancellous bone grafting with a holding locking screw appears to be a reliable primary procedure for non-union of the forearm diaphyseal fracture without infection. Level of evidenceIV; therapeutic study.

Radiographically confirmed outcomes after fracture repair with a PLS polyaxial locking system in 40 dogs and cats.

To report radiographic findings and complications after fracture repair with a new polyaxial locking plate system (PLS polyaxial locking system; Aesculap/B Braun, Tuttlingen, Germany) in dogs and cats. Retrospective case review from four veterinary practices. Twenty-six dogs and 14 cats (40 long bone fractures). Medical and radiographic records of dogs and cats with long bone fractures treated with the PLS were reviewed. Cases were included when operative records were complete and included documentation of radiographic union or complications. Phone interviews of owners were performed for long-term follow-up. Ancillary methods of fracture fixation and associated complications were recorded. Only two complications were recorded, one of which required a revision surgery. Radiographic follow-up was performed for all fractures. Radiographic union without complications was achieved in 38 of 40 (95%) fractures. Radiographic union was documented before 60 days in 19 of 40 (47.5%) fractures, between 61 and 90 days in 15 of 40 (37.5%) fractures, and after 90 days in six of 40 (15%) fractures. A functional union was observed at a mean time ± SD of 70.8 ± 38.9 days (range, 32-182). One or more ancillary fixation methods were used in 27 of 40 (67.5%) fractures. The PLS polyaxial locking system was often used with adjunct fixation in this series, and radiographically confirmed healing without complications was documented in most cases. Use of the PLS can result in high success rates for fracture repair in dogs and cats, but ancillary fixation should be strongly considered.

Locking versus non-locking plating system in the treatment of mandibular fractures: A randomized comparative study

To evaluate fracture stability and complications such as infections, need for hardware removal, malunion, and nonunion when using 2.0-mm locking plating system in fixation of mandible fractures and to compare these to those associated with the 2.0-mm non-locking plating system.A prospective clinical study was conducted in a cohort of mandible fracture patients who were randomly assigned to two groups. Patients in the non-locking group were treated with 2.0-mm non-locking plating system, and those in locking group were treated with 2.0-mm locking plating system. Fracture stability, need for maxillomandibular fixation (MMF) and postoperative complications were assessed and compared.A total of 60 patients (30 in each group) were recruited. Significant differences were found between the two groups with respect to postoperative fracture stability (P = 0.001) and need for MMF (P = 0.005). Multivariate analysis revealed that type of fixation was not the only dependent variable which affected fracture stability. There were no significant differences in postoperative complications between the two groups.The 2.0-mm locking plating system provides greater stability and early functional restoration than the 2.0-mm non-locking plating system, with similar rates of postoperative complications. Thus, it can be used as a reliable and effective treatment modality for treating mandibular fractures.

Does the length of the plate affect the failure rate of hallux MTP joint arthrodesis for severe hallux valgus?

PurposeThe purpose of this study was to investigate the effect of the length of the dorsal locking plate on the failure rate of first MTP joint arthrodesis for severe hallux valgus deformities. MethodsA retrospective review was conducted for all patients who underwent first MTP joint arthrodesis using solely a specific locked plating system (Depuy-Synthes, Raynham, MA) for severe hallux valgus deformities between January 2014 to June 2017. Patients were divided into subgroups according to the length of the plate and the failure rate was investigated. Furthermore, radiographic parameters including intermetatarsal angle (IMA) and hallux valgus angle (HVA) were evaluated in weightbearing AP foot radiographs. ResultsA total of 25 patients were included in this study. There were 16 (64%) patients in the medium-sized plate cohort and 9 (36%) patients in the small-sized plate cohort. We found a significant difference in the failure rate between the two groups; only 1 (6.25%) failure case occurred in the medium-sized plate cohort while 4 (44.44%) failure cases occurred in the small-sized plate cohort (P = .040, Odds ratio (OR) = 12.000, 95% Confidence Interval (CI) = 1.074, 134.110). The mean postoperative IMA and HVA were significantly improved in both cohorts. However, significant differences were found between the two cohorts in final follow-up IMA and HVA (P = .002 and P < .001, respectively). ConclusionsFor severe hallux valgus deformities, the use of longer plates to gain additional purchase in the diaphyseal bone may help mitigate the increased stresses placed on the fixation constructs for first MTP joint arthrodesis and decrease failure rate. Level of EvidenceLevel III, case control study.

The Use of a Locking Plate for the Treatment of Femoral Diaphyseal Fracture in Giant Anteaters (Myrmecophaga tridactyla)

Background: The giant anteater is considered a species vulnerable to trauma due to being slow and, therefore, vulnerable to long bone fractures, such as femoral fracture. Locking plates have the potential to restore and maintain fractured bone stability, as well as reduce damage to the vascular supply. This study aims at reporting cases of two giant anteaters subjected to femoral osteosynthesis using locking plates. Cases:Two giant anteaters presenting non-weight bearing lameness on the right pelvic limbs were evaluated, diagnosed with femoral fracture of unknown etiology and submitted to osteosynthesis. A clinical evaluation was performed under chemical restraint for the adult animal and physical restraint for the young one. Crepitation and swelling in the right femur topography led to a radiographic examination, which showed a complete and transverse diaphyseal fracture of the right femur in both cases. The first one was an adult male and was subjected to osteosynthesis of the right femur using a locking plate. Once anesthetized, the animal was placed in left lateral recumbency, and the right pelvic limb was clipped and sterilized. A craniolateral incision was made to expose the femoral diaphysis. A large amount of fibrous-looking tissue was found and removed. Subsequently, the fracture was reduced and the locking plate system was positioned on the craniolateral side of the femur. An osteotomy of the femoral trochanteric crest was required to position the implant. The overlying fascia lata was closed using monofilament suture in a simple continuous pattern. The closure of the subcutaneous tissue and skin was performed using a Cushing pattern and simple interrupted pattern, respectively. Immediate postoperative radiographic examinations showed fracture reduction and bone axis alignment, with a properly positioned implant. The surgical wound was cleaned daily with 0.5% aqueous chlorhexidine solution. Seven days after surgery, the animal had a partial dehiscence at the suture site, with bone and plate exposure. Wound healing by second intention was initiated. At 127 days after surgery, a radiographic examination showed periosteal bone proliferation in the middle third of the right femur and that the bone implants were well-positioned. The second case was of a young 3.68 kg female anteater. The surgery was performed as described for the adult one, but there was no fibrosis at the fracture site and the osteotomy of the femoral trochanteric crest was not required. Closure of the fascia lata, subcutaneous tissue, and skin was performed as in Case 1. An immediate postoperative radiographic examination showed fracture reduction, bone axis alignment, and a properly positioned implant. The surgical wound was cleaned daily with 0.5% aqueous chlorhexidine solution. On the day of the surgery, the animal could already bear weight on its right pelvic limb, presenting discrete lameness with gradual improvement. Twenty-three days after surgery, a radiographic examination showed moderate periosteal bone proliferation in the middle third of the right femur. The bone implant was still well-positioned and bone healing was achieved around the 40th post-operative day.Discussion:The cases are very similar, but the younger anteater's femoral trochanteric crest didn't prevent positioning the plate. The fibrosis observed on the adult specimen is indicative of a chronic fracture, which may explain, in conjunction with the post-surgical complications, the longer time required for bone healing in the adult animal. Even so, both animals recovered fully and it's safe to deduce that the locking plate is an adequate option for internal fixation in transverse diaphyseal femoral fractures in both adult and young giant anteaters.

Assessment of variable angle volar locking plate as a tool for treatment of unstable intra articular distal radius fractures

Background: Distal radius fractures are one of the common fractures, more so in geriatric age group. Functional outcome is of paramount importance, thus efficacy of newer implant systems remains to be evaluated in terms of patient satisfaction and functional results. Methods: This prospective study involves 35 patients, all having unstable distal radius fractures and treated with Open reduction and Internal Fixation using Variable Angle Locking Plate system. The mean age of patients was 54 years. The PRHWE score was used for evaluation, and radiological assessment as a tool for fracture healing and union. At the time of final evaluation outcome was assessed as per Gartland and Werley scoring system. Results: Average Range of motion as achieved in the present study was recorded as Pronation 79.35 Degree, Supination 82.32 Degree, Palmar flexion 59 Degree, Dorsiflexion 61.8 Degree & Ulnar deviation 3.30 Degree. Radiological parameters as measured at final evaluation were: Volar tilt 5.55 Degree, Radial inclination 18 Degree & Ulnar variance -0.52 mm. At 6 months mean PRHWE score was 6.85 (SD±2.87). At 12 months mean PRHWE score was 4.52 (SD±2.30) Out of 35 patients, 32 patients had final score between 0 to 5 which was statistically significant (P

Effect of Humeral Locking Plate System on Absorbed Energy in Breast Tissue with Different Radiological Energies Using MCNPX Code

Abstract This study aimed to investigate the radiation absorption effects of the humeral locking plate system on breast tissue in different radiological energy ranges using MCNPX (Monte Carlo N-Particle Extended Transport Code System, version 2.6.0) general-purpose Monte Carlo code. In the present study, a novel MCNPX simulation setup has been generated considering the elemental mass fractions of investigated materials and biological structures. The validation of MCNPX simulation geometry used in this study has been provided by comparing the results with standard XCOM data for mass attenuation coefficients of Ti-6Al-4V alloy. A very good match between XCOM and MCNPX data has been achieved. Therefore, validated simulation input has been employed for further investigations of the present study. Our findings showed that the amount of absorbed energy that was measured in breast tissue with the humeral locking plate was higher than that without humeral locking plate for the same radiological energy value. Our results would be beneficial to use the present simulation technique and mass attenuation coefficients for radiation physics and medical applications, especially for assessments of breast cancer risk.

Assessment of the efficacy of the far cortical locking technique in proximal humeral fractures: a comparison with the conventional bi-cortical locking technique

BackgroundLocking plate fixation is one of the treatment strategies for the management of proximal humeral fractures. However, stiffness after locking plate fixation is a clinical concern. The mechanical stiffness of the standard locking plate system may suppress the interfragmentary motion necessary to promote secondary bone healing by callus formation. The far cortical locking (FCL) technique was developed to address this limitation in 2005. FCL increases construct flexibility and promotes callus formation. Our study aimed to evaluate the clinical and radiological outcomes of the FCL technique when implemented in proximal humeral fracture management. Furthermore, we compared the surgical outcomes of FCL with those of the conventional bicortical locking (BCL) screw fixation technique.MethodsForty-five consecutive patients who had undergone locking fixation for proximal humeral fractures were included in this study. A proximal humeral locking plate (PHILOS) system with BCL screw fixation was used in the first 27 cases, and the periarticular proximal humeral locking plate with FCL screw fixation was used in the final 18 consecutive cases. Functional capacity was assessed using the constant score, American Shoulder and Elbow Surgeons (ASES) score, and range of motion. Radiographic outcomes were evaluated using the Paavolainen method of measuring the neck-shaft angle (NSA).ResultsNo significant differences in clinical outcomes (ASES score, constant score, and range of motion) were found between the two groups. The union rate at 12 weeks was significantly higher in the FCL group (94.4%) than in the BCL group (66.7%, p = 0.006). No significant differences in NSA were found between the two treatment strategies. The complication rate was not significantly different between the two groups.ConclusionsWhen implemented in proximal humeral fractures, the FCL technique showed satisfactory clinical and radiological outcomes as compared with the conventional BCL technique. The bone union rate at 12 weeks after surgery was significantly higher in the FCL group than in the BCL group. However, no significant difference in the final bone union rate was found between the two groups.

Biomechanical In Vitro Study on the Stability of Patient-Specific CAD/CAM Mandibular Reconstruction Plates: A Comparison Between Selective Laser Melted, Milled, and Hand-Bent Plates.

An experimental in vitro study. Plate fractures are a recurrent problem in alloplastic mandibular reconstruction. Hypothetically it can be assumed that computer-aided design (CAD)/computer-aided manufacturing (CAM) reconstruction plates have a higher stability than conventional hand-bent plates. The aim of the study was to compare additive and subtractive fabricated CAD/CAM mandibular reconstruction plates as well as conventional plates with regard to their biomechanical properties. In a chewing simulator, plates of 2 conventional locking plate systems and 2 CAD/CAM-fabricated plate systems were compared. The plates were loaded in a fatigue test. The maximum number of cycles until plate fracture and the plate stiffness were compared. While all conventional plates fractured at a maximum load between 150 and 210 N (Newton) after a number of cycles between 40 000 and 643 000, none of the CAD/CAM plates broke despite a nearly doubled load of 330 N and 2 million cycles. Both CAD/CAM systems proved to be significantly superior to the hand-bent plates. There was no difference between the 2 CAD/CAM systems. Concerning the risk of plate fracture, patient-specific CAD/CAM reconstruction plates appear to have a significant advantage over conventional hand-bent plates in alloplastic mandibular reconstruction.

Fixation Stability and Stiffness of Two Implant Systems for Proximal Femoral Varization Osteotomy

Proximal femoral varization osteotomy is a well-established surgical procedure in children with severe hip problems. This study aimed to evaluate the fixation stability and stiffness of two new implant systems. A biomechanical testing model was created with a total of 12 synthetic femora. Proximal femoral varization osteotomy was performed in every femur, and the synthetic femora were fixed with two different implant systems (PediLoc Locking Proximal Femur Plate System versus PediLoc Locking Cannulated Blade Plate System; OrthoPediatrics, Warsaw, IN, USA). The average torsional stiffness of the locking plate group was higher than for the cannulated blade plate group. Differences in internal and external rotations were seen between the two groups, but they were not significant. Using the tested implants in severe osteoporotic bones might show other results. Therefore, it might be helpful to use the locking plate system in osteoporotic bones and in cases of revision operations where stability is of critical focus.

Investigation of Biomechanical Characteristics of Orthopedic Implants for Tibial Plateau Fractures by Means of Deep Learning and Support Vector Machine Classification

An experimental comparative study of the biomechanical behavior of commonly used orthopedic implants for tibial plateau fractures was carried out. An artificial bone model Synbone1110 was used and a Schatzker V type tibial plateau fracture was created in vitro, then stabilized with three different implant types, classic L plate, Locking Plate System (PLS), and Hybrid External Fixator (HEF). The stiffness of the bone—implant assembly was assessed by means of mechanical testing using an automated testing machine. It was found that the classic L plate type internal implant has a significantly higher value of deformation then the other two implant types. In case of the other implant types, PLS had a better performance than HEF at low and medium values of the applied force. At high values of the applied forces, the difference between deformation values of the two types became gradually smaller. An Artificial Neural Network model was developed to predict the implant deformation as a function of the applied force and implant device type. To establish if a clear-cut distinction exists between mechanical performance of PLS and HEF, a Support Vector Machine classifier was employed. At high values of the applied force, the Support Vector Machine (SVM) classifier predicts that no statistically significant difference exists between the performance of PLS and HEF.

Comparison of optimal screw configurations in two locking plate systems for proximal humerus fixation - a finite element analysis study

BackgroundManagement of proximal humerus fractures is challenging, especially in elderly. Locking plating is a common surgical treatment option. The Proximal Humerus Internal Locking System (plate-A) has shown to lower complication rates compared to conventional plates, but is associated with impingement risk, which could be avoided using Peri-articular Proximal Humerus Plate (plate-B). Nevertheless, biomechanical performance and optimal screw configuration of plate-B is unknown. The aim of this study was to evaluate different screw configurations of plate-B and compare with plate-A using finite element analyses. MethodsTwenty-six proximal humerus models were osteotomised to create unstable three-part fractures, fixed with either of the two plates, and tested under three anatomical loading conditions using a previous established and validated finite element simulation framework. Various clinically relevant screw configurations were investigated for both plates and compared based on the predicted peri-implant bone strain, being a validated surrogate of cyclic cut-out failure. FindingsBesides increasing the number of screws, the placement of the posterior screws in combination with the calcar screw in the plate-B significantly decreased the predicted failure risk. Generally, plate-A had a lower predicted failure risk than plate-B. InterpretationThe posterior and calcar screws may be prioritized in plate-B. Compared to plate-A, the more distal positioning, less purchase in the posterior aspect and a smaller screw spread due to not fitting of the most distal calcar screw in most investigated subjects led to a significantly higher predicted failure risk for most plate-B configurations. The findings of the simulations study require clinical corroboration.