PHILOS Plates Research Articles

PHILOS (Proximal Humerus Internal Locking System) Plating vs MultiLoc Nailing in Proximal Humerus Fracture: Systematic Review and Meta-Analysis of Radiological and Functional Outcomes.

Proximal humeral fractures, predominantly affecting the elderly, pose significant treatment challenges due to the complex anatomy of the shoulder joint and variability in bone quality. MultiLoc nails (Synthes USA Products, West Chester, USA) are the latest construct, and PHILOS (Proximal Humerus Internal Locking System, (Synthes USA Products, West Chester, USA)) plates are the earlier construct used for the fixation of proximal humerus fractures. This systematic review aims to provide a comparison of MultiLoc nails and PHILOS plates, focusing on their effectiveness, safety, and patient outcomes. Our study included randomized controlled trials (RCTs) and observational studies comparing the effectiveness of MultiLoc nails and PHILOS plates. We searched literature in databases, including PubMed, EMBASE, and Web of Science, until December 20, 2023. The primary outcome of focus was the Neck Shaft Angle, supplemented by a range of secondary surgical and functional outcomes. The Nested Knowledge web software (Nested Knowledge, Inc., Saint Paul, USA) facilitated the screening and data extraction processes. The quality of included studies was assessed using the Cochrane Risk of Bias tool for RCTs (Cochrane, London, UK) and the ROBINS-I (Risk Of Bias In Non-randomised Studies - of Interventions) tool for observational studies (Cochrane, London, UK). R software version 4.3 (R Foundation for Statistical Computing,Vienna,Austria) was used to synthesize the collected data. Six studies met the inclusion criteria, primarily involving older adults in their mid-50s to late 70s. While MultiLoc nails offer shorter operation times and potentially reduced blood loss, both techniques effectively maintain the Neck Shaft Angle, a crucial factor for shoulder function. Comparable Constant-Murley scores and complication rates were observed between the two methods. PHILOS plates showed higher American Shoulder and Elbow Surgeons Shoulder Score(ASES) scores for two-part proximal humeral fractures with displacement. Other observations suggested advantages of MultiLoc nails in terms of faster union and fewer complications.

Biomechanics of PHILOS plates in Vancouver B1 periprosthetic femoral fracture.

Objective: To investigate the clinical efficacy of PHILOS plates in the treatment of Vancouver B1 periprosthetic femoral fracture (PFF) and to validate its biomechanical reliability via finite element analysis and mechanical testing on the Synbone femoral models. Methods: Ten males and eight females with Vancouver B1 PFF who underwent PHILOS plate fixation between September 2017 and January 2022 were selected. The average age was 72.61 ± 8.19years, with a range of 57-86years old. X-ray films were taken to assess the fracture healing situation around the femoral prosthesis as well as the position of the PHILOS plates and femoral prosthesis. Two different plates (the PHILOS plate and the Cable GTR plate) were used for fixation, and the differences in biomechanical stability of the two fixation methods were compared using finite element analysis and mechanical testing on the Synbone femoral models to validate the biomechanical dependability of the PHILOS plate. Results: All 18 cases were followed for at least 1year, as a result. The average period of follow-up was 17months, ranging from 12 to 36months. At the most recent follow-up, Harris scores for the hip joints of patients ranged from 82 to 89, with an average score of 86. The X-rays revealed that all fractures surrounding the femoral prosthesis had healed and that there was no looseness in the femoral prosthesis. None of the PHILOS license plates had expired. All patients were able to perform full-load walking, and pain and claudication in affected limbs were significantly reduced. Finite element analysis and mechanical testing of the Synbone femoral model revealed that the fixation effect of the PHILOS group was superior to that of the Cable group; consequently, PHILOS plates can be used to effectively fix fractures around the proximal femoral prosthesis. Conclusion: PHILOS plates are initially used in the treatment of Vancouver B1 PFF, which may be a good choice due to their simpler operation, lower medical costs, and satisfactory clinical efficacy.

HELICAL VERSUS STRAIGHT PLATING OF PROXIMAL THIRD HUMERAL SHAFT FRACTURES - A BIOMECHANICAL STUDY

Proximal humeral shaft fractures are commonly treated with long straight locking plates endangering the radial nerve distally. The aim of this study was to investigate the biomechanical competence in a human cadaveric bone model of 90°-helical PHILOS plates versus conventional straight PHILOS plates in proximal third comminuted humeral shaft fractures.Eight pairs of humeral cadaveric humeri were instrumented using either a long 90°-helical plate (group1) or a straight long PHILOS plate (group2). An unstable proximal humeral shaft fracture was simulated by means of an osteotomy maintaining a gap of 5cm. All specimens were tested under quasi-static loading in axial compression, internal and external rotation as well as bending in 4 directions. Subsequently, progressively increasing internal rotational loading until failure was applied and interfragmentary movements were monitored by means of optical motion tracking.Flexion/extension deformation (°) in group1 was (2.00±1.77) and (0.88±1.12) in group2, p=0.003. Varus/valgus deformation (°) was (6.14±1.58) in group1 and (6.16±0.73) in group2, p=0.976. Shear (mm) and displacement (°) under torsional load were (1.40±0.63 and 8.96±0.46) in group1 and (1.12±0.61 and 9.02±0.48) in group2, p≥0.390. However, during cyclic testing shear and torsional displacements and torsion were both significantly higher in group 1, p≤0.038. Cycles to catastrophic failure were (9960±1967) in group1 and (9234±1566) in group2, p=0.24.Although 90°-helical plating was associated with improved resistance against varus/valgus deformation, it demonstrated lower resistance to flexion/extension and internal rotation as well as higher flexion/extension, torsional and shear movements compared to straight plates. From a biomechanical perspective, 90°-helical plates performed inferior compared to straight plates and alternative helical plate designs with lower twist should be investigated in future paired cadaveric studies.

Minimally invasive plate osteosynthesis for segmental humerus fractures with a helical plate. Which distal fixation—the anterior or lateral—is superior?

Aim: In order to achieve adequate stability in segmental humerus fractures, the PHILOS fixation with minimal invasive approach comes into use instead of conventional plating. However, according to the AO classification, 12C type segmental humerus fractures treated with minimally an invasive method are prone to complications. The purpose of this prospective study is to compare functional outcomes and complication rates following two different angled helical PHILOS plate fixation. Material and Method: This multicenter study is a prospective review of cases with a final follow-up outcome. Twenty-two patients with AO 12-C humerus fractures underwent PHILOS fixation with contoured PHILOS plates between January 2016 and June 2019. Patients evaluated in two groups. Group 1 consisted 12 patients who were treated with a 30° helical plate and Group 2 consisted 10 patients who were treated with 70° helical plate. Clinical outcomes were noted according to the Constant-Murley scoring system. Results: The mean age of patients treated in groups 1 and 2 were 49±15.8 and 50.7±17, respectively. Fractures healed in an average of 13.1±3.9 weeks in Group 1 and 13.8±3.1week in Group 2, respectively. The mean follow-up period of the patients was 18±6.1months in Group 1 and 22±4.2 months in Group 2. Mean Constant-Murley scores at final follow-up were 88±2.7 and 90±2.5 in Groups 1 and 2 respectively (p=.665). Radial nerve neuropraxia was seen in 2 cases in Group 1, and a sensorial injury of the musculocutaneous nerve was seen in 1 patient in Group 2 (p=.365). Conclusion: Similar union rates and successful clinical results were obtained from both groups. However, this study suggests that the 70° angled helical PHILOS technique could be performed relatively easily in AO 12-C fractures with fewer complication rates. Musculocutaneous nerve affliction can be as functionally destructive as radial nerve affliction.

One size may not fit all: patient-specific computational optimization of locking plates for improved proximal humerus fracture fixation.

Optimal treatment options for proximal humerus fractures (PHFs) are still debated because of persisting high fixation failure rates experienced with locking plates. Optimization of the implants and development of patient-specific designs may help improve the primary fixation stability of PHFs and reduce the rate of mechanical failures. Optimizing the screw orientations in locking plates has shown promising results; however, the potential benefit of subject-specific designs has not been explored yet. The purpose of this study was to evaluate by means of finite element (FE) analyses whether subject-specific optimization of the screw orientations in a fixed-angle locking plate can reduce the predicted cutout failure risk in unstable3-part fractures. FE models of 19 low-density proximal humeri were generated from high-resolution computed tomographic images using a previously developed and validated computational osteosynthesis framework. The specimens were virtually osteotomized to simulate unstable malreduced 3-part fractures and fixed with the PHILOS plates using 6 proximal locking screws. The average principal compressive strain in cylindrical bone regions around the screw tips-a biomechanically validated surrogate for the risk of cyclic screw cutout failure-was defined as the main outcome measure. The angles of the 6 proximal locking screws were optimized via parametric analysis for each humerus individually, resulting in subject-specific screw orientations (SSO). The average peri-implant strains of the SSO were statistically compared with the previously reported cohort-specific (CSO) and original PHILOS screw orientations (PSO) for females vs. males. The optimized SSO significantly reduced the peri-screw bone strain vs. CSO (6.8% ± 4.0%, P = .006) and PSO (25.24% ± 7.93%, P < .001), indicating lower cutout risk for subject-specific configurations. The benefits of SSO vs. PSO were significantly higher for women than men. The findings of this study suggest that subject-specific optimization of the locking screw orientations could lead to lower cutout risk and improved PHF fixation. These computer simulation results require biomechanical and clinical corroboration. Further studies are needed to evaluate whether the potential benefit in stability could justify the increased efforts related to implementation of individualized implants. Nevertheless, computational exploration of the biomechanical factors influencing the outcome of fracture fixations could help better understand the fixation failures and reduce their incidence.

The missing piece of the trauma armoury-medial femoral condyle plate

Fixation of distal femoral fractures is often challenging due to the fracture configuration and associated poor bone quality. Dual plating (lateral and medial) has become an acceptable option to provide improved stability versus a single plate fixation.Though there are several commercially available anatomically designed plates for the lateral femoral condyle, there is no anatomic plate available in UK specifically for medial fixation of distal femur fractures.Our aim is to determine the best suited pre-contoured plate for stabilising the medial femoral condyle (MFC).Right sided femur sawbones were used to determine how well 18 different pre-contoured anatomical plates (Depuy Synthes, Leeds, UK) fit the medial femoral condyle. Some of these had variable angle (VA) option. Lift off, fit and notch penetration were assessed and recorded independently by 4 orthopaedic trauma surgeons. The number and distribution of screws in the MFC that each plate allowed was also determined. To do this the MFC was divided into quadrants: Proximal anterior (PA), distal anterior (DA), proximal posterior (PP) and distal posterior (DP).The ipsilateral anterolateral proximal tibial (VA and 4.5 mm non-VA), PHILOS, posteromedial proximal tibial and ipsilateral lateral extra-articular distal humeral plate offered good sagittal fit, less than 2 mm lift off at the condyles and no diaphyseal lift off. Plate positioning in the PA quadrant offered the best fit.The ipsilateral anterolateral proximal tibial plates (VA) and PHILOS allowed at least 4 screws to be placed in the PA and 2 in the PP quadrant with no notch penetration. The Tomofix provided good fit, but all 4 screws were in PA quadrant, with distal screws causing notch penetration. The non-VA and PHILOS plates did not offer the VA advantage.The ipsilateral anterolateral proximal tibial VA plates provided the best anatomical fit for the MFC with the greatest number of screws in the condylar quadrants with the option of variable angle screw placement.

Treatment of humeral fractures with long PHILOS plates using a modified technique and approach avoids radial nerve palsy in the last 10 years

Abstract Objective Radialis paresis is a known complication of plate osteosynthesis of the proximal humeral shaft. There are major differences with regard to surgical approach and implant. The standard treatment is a lateral-lateral approach. Here, iatrogenic damage to the radial nerve is a relevant complication. In our institution, these fractures have been treated with an adapted procedure for about 10 years. A long Philos plate is inserted proximally via a deltoido-pectoral approach. The plate is first torqued distally by about 45°-90° and then lies anteriorly on the humerus. The distal screws can be placed via anterior stab incisions. The advantage of this technique is that the implant and approach respect the anatomical course of the radial nerve and it does not have to be manipulated in an open exploratory manner. The aim of the study is to demonstrate the effectiveness of the surgical technique in relation to iatrogenic radial nerve paresis in comparison to the literature. Methods We analysed patients with a proximal humeral shaft fracture who were treated at our clinic with a long torqued philos plate using the adapted surgical method over the last 10 years. The fracture, the occurrence of iatrogenic radial damage and biometric data of the patients were analysed retrospectively. Results We found a total of 59 patients who underwent surgery according to the above-mentioned scheme between 2010 and 2020. The average age was 70.1 (40-101) years. There were 44 women and 15 men. 2 patients had a preoperatively documented radial nerve damage. In 57 patients, no damage could be found in the radialis supply area both pre- and postoperatively. 2 patients died shortly after surgery, 6 patients were loss to follow up. 2 patients had a tear of the distal plate bearing (1 malcompliance/1 pseudarthrosis). Both had to be revised. In the remaining 47 patients (78%), the healing process was unremarkable. Conclusion The described treatment of the proximal humeral shaft fracture has been successfully practised at our clinic for 10 years. Most of the fractures healed without complications. Compared to the exploration of the nerve, this method respects the anatomical course of the nerve and shows in the retrospective analysis that no iatrogenic damage to the radial nerve occurred. Thus, the surgical method represents a valid alternative to the established implants and classical surgical treatments.

Shoulder function after helical long PHILOS plate.

In order to minimize the risk of damaging the radial nerve while using a long PHILOS plate for proximal humerus fractures, recent studies have proposed twisting the plate in a helical form. This implies a modified surgical approach being yet unclear whether it leads to different middle to long-term shoulder function. This study compares the one-year shoulder functional outcomes of both techniques (helical vs. control). In this retrospective comparative study, we analyzed 30 patients that fit the inclusion criteria, being 14 treated with a helical plate and 16 with a conventional straight long PHILOS plate. The primary endpoint was the normalized constant score after a minimum follow up of one year. Both groups had a good one-year shoulder function, and no significant difference between the normalized constant scores was seen. There was no significant difference in the surgical complications as well. Opting for a helical long PHILOS plate in order to avoid radial nerve damage provided a safe treatment with similarly good one-year shoulder function compared to straight PHILOS plates. Level 3, Retrospective Cohort Study.

The results of open reduction and plate fixation with angular stability of the proximal humerus fractures in patients with osteoporosis

Objective: a retrospective study of anatomical and functional results of open reduction and plate osteosynthesis in patients older than 50 years with of the proximal humerus fractures type AO/OTA 11-B, 11-C and osteoporosis, who were treated with plate PHILOS taking into account the surgical treatment of adverse results with reverse total shoulder arthroplasty (RTSA). Methods: we analyzed case histories of 58 patients (age older 50 years) with osteoporosis and three- and four-fragment fractures of the proximal umerus according to the Neer classification (type AO/OTA 11-B, 11-C). In group I — 20 patients (age from 50 to 76 years, 8 men and 12 women) — we made open reduction, ORIF with plate PHILOS; II — 38 patients (aged 54 to 78 years, all women) — had surgeries ORIF with PHILOS plate and 3D polylactide implants. Results: according to the Constant Murley Shoulder Score system in 11 (55 %) patients of group I excellent and good results were obtained, in 5 (25 %) — satisfactory, in 4 cases (20%) are unsatisfactory. At the last cases we made RTSA in terms from 6 to 12 months after the primary surgery, one of them had revision RTSA due to fracture of the humeral shaft and instability of the stem implant. According to the Constant Murley Shoulder Score system, the average score after 12 months in group I was 78, in II — 87. No signs of avascular necrosis of the humeral head were observed. Conclusions: the use of PHILOS plates with additional reinforcement with 3D polylactide implants allowed us to obtain positive results in 34 (89.5 %) patients after 6–12 months after the surgery with a lower complications rate compare to known techniques. If ORIF method gives an unfavorable result then RTSA gives the possibility to achieve positive results within 3 years after the surgery.

Comparing iatrogenic radial nerve lesions in humeral shaft fractures treated with helical or straight PHILOS plates: a 10-year retrospective cohort study of 62 cases

Humerus shaft fractures are common and often treated surgically with a proximal humerus internal locking system like the long PHILOS® plate. Due to its close anatomical proximity to the humerus, the radial nerve is particularly susceptible to traumatic and iatrogenic damage. The iatrogenic radial nerve damage associated with internal locking systems is described in about 7% of the cases. In order to avoid this lesion, helical plates have been suggested since 1999. This technique continues to not being used as standard as there is still a clear lack of evidence. This study aimed to understand if twisting a long PHILOS plate can reduce the rate of iatrogenic radial nerve damage in humerus shaft fractures. In this 10-year retrospective comparative study, patients with primary traumatic proximal humerus shaft fracture treated with a straight or twisted helical PHILOS® plate were analyzed and compared. Among the 62 patients meeting the inclusion criteria between 2008 and 2018, 33 received a conventional straight plate, while 29 were treated with a helical plate. The primary endpoint was iatrogenic radial nerve damage immediately after surgery with a follow-up of at least 3months. No case of radial nerve damage was reported in the helical group. In the control group, iatrogenic radial nerve damage occurred in two cases (6%), which was not statistically significant when comparing both groups (p = 0.18). Manually twisting long PHILOS® plates is a safe procedure to avoid radial nerve lesion in humerus shaft fractures. Even though the group size did not allow a statistically relevant difference, we underline that only the helical group showed no iatrogenic radial lesion. This technique deserves further attention. Level 3, retrospective cohort study.

Axillary nerve elongation in humeral fracture plating: A cadaveric study for comparison between straight and helical Philos plates

ObjectiveHelical plating is a known concept in humeral fracture treatment. Attention should be paid to the axillary nerve when inserting a plate underneath the deltoid muscle. The purpose of this cadaveric study was to estimate axillary nerve stretching when introducing the plate. Methods: On 42 fresh frozen human humeri, an 8-, 10- and 12-hole Philos plate in a straight and a helical shape were compared measuring the maximum plate-bone-distance. Results: For all three plate lengths, the helical plates had a significantly lower plate-bone-distance. Conclusion: Indirectly, this suggests a lower axillary nerve elongation and hence less chance of nerve damage.

The results of clinical trial with polylactide implants for osteosynthesis of proximal humerus fractures in patients with osteoporosis

Proximal humerus fractures (AO/OTA 11) occur in 5–6 % of the trauma structure and most often are in people older than 50 years. There is no currently existing universally accepted approach to the treatment of proximal humerus fractures with osteoporosis. Objective: to analyze the results of surgical treatment of patients with multifragments proximal humerus fractures and osteoporosis using PHILOS type plate and polylactide implants. Methods: 38 women with osteoporosis were made surgeries with PHILOS and polylactide implants; their age was from 54 to 78 years, at the period 2015–2019. 32 patients had three-fragment proximal humerus fracture by Neer (AO/OTA 11-B), 6 — four-fragment (AO/OTA 11-C). The results were evaluated by Constant-Murley Shoulder Score in 3, 6, 12 and 24 months after surgery. Results: there was fracture healing in all patients. We did not observe any avascular head necrosis. The average score by Constant-Murley Shoulder Score after 3, 6, 12 and 24 months after surgery was equal to 78.2; 82.1; 87.2 and 87.2 points, respectively. One patient had a perforation by screw; two patients had a superficial infection that was eliminated with antibacterial therapy. There was a secondary displacement of small tubercle of the humeral head up to 8–10 mm in one patient after 3 months without any harm to shoulder joint function. Conclusions. PHILOS plates with reinforcement of polylactide implants allowed to achieve 89.5 % positive results in the period from 6 to 24 months after the surgery in patients with multifragments proximal humerus fractures and osteoporosis. There is low level of complications comparing with other available methods (mean score for Constant-Murley Shoulder Score 87.2).

To evaluate intraoperative technical difficulties during PHILOS plating for treatment of displaced proximal humerus fractures

Background: This is a Prospective study carried out at Department of Orthopaedics & traumatology, Amaltas Institute of Medical Sciences, Dewas, M.P. in 30 patients of proximal humerus fracture were attended in casualty and OPD and were admitted.Result: Most of the injuries caused by was road traffic accident. In our study, patients with two part fracture had better functional outcome as compared to patients with three and four part fracture.Conclusion: The internal fixation with the PHILOS plate seems to be a reliable option in the operative treatment of upper end humeral fractures, especially in osteoporotic bone. It allows secure fracture fixation and quick shoulder mobilization. PHILOS plates are pre-shaped & pre-contoured plates to match proximal humeral anatomy with multiple proximal locking screw placement options has made fixation of complex fractures easy. It provides rigid fixation, enhanced axial & angular stability & allows early mobilization of the shoulder without compromising fracture union.

Screw configuration in proximal humerus plating has a significant impact on fixation failure risk predicted by finite element models

Proximal humeral fractures occur frequently, with fixed angle locking plates often being used for their treatment. No current quantitative evidence for the effect of different screw configurations exists, and the large number of variations makes biomechanical testing prohibitive. Therefore, we used an established and validated finite element osteosynthesis test kit to quantify the effect of variations in screw configuration on predicted failure risk of PHILOS plate fixation for unstable proximal humerus fractures. Twenty-six low-density humerus models were osteotomized to create malreduced unstable 3-part fractures that were virtually fixed with PHILOS plates. Twelve screw configurations were simulated: 6 using 2 screw rows, 4 using 3 rows, and 1 with either 8 or 9 screws. Three physiological loading cases were modeled and an established finite element analysis methodology was used. The average peri-screw bone strain, previously demonstrated to predict fatigue cutout failure, was used to compare the different configurations. Significant differences in peri-screw strains, and thus predicted failure risk, were seen with different combinations. The 9-screw configuration demonstrated the lowest peri-screw strains. Fewer screw constructs showed lower strains when placed further apart. The calcar screws (row E) significantly (P < .001) reduced fixation failure risk. Screw configurations significantly impact predicted cutout failure risk for locking plate fixations of unstable proximal humerus fractures in low-density bone. Although requiring clinical corroboration, the result of this study suggests that additional screws reduce peri-screw strains, the distance between them should be maximized whenever possible and the calcar screws should be used.

Optimal viewing angles of intraoperative fluoroscopy for detecting screw penetration in proximal humeral fractures: a cadaveric study

BackgroundTo identify the optimal viewing angles for every proximal screw in PHILOS plate-fixed proximal humeral fractures.MethodsThree fresh-frozen human cadaveric bodies with six intact shoulders were studied. All three bodies were put in the beach chair position and PHILOS plates were placed on the proximal humerus. Head screws penetrating 1 mm into the joint were fitted one by one. Fluoroscopy was conducted in the 180° horizontal plane and the 120° coronal plane to analyze each screw’s penetration in every shoulder. Images were taken every 5°, then all images were analyzed to identify the sensitive angles.ResultsThe range of optimal viewing angles to visualize penetration of every head screw was identified. In the coronal plane, the angles in the range between 0° and 10° were sensitive to all screws except No. 8 and No. 9. Furthermore, penetration of screws No. 8 and 9 could not be identified on any axillary view, but could be identified in the horizontal plane from − 30° to − 10° and from 10° to 35° respectively.ConclusionsWe recommend a 0°–10° axillary view with 30° arm abduction combined with two horizontal angles in the range of − 30° to − 10° and 10° to 35° for routine fluoroscopy during surgery. Our results will be helpful in avoiding primary screw penetration.

Proximal third humeral shaft fractures fixed with long helical PHILOS plates in elderly patients: benefit of pre-contouring plates on a 3D-printed model\u2014a retrospective study

BackgroundTo explore the clinical efficacy of 3D printing fracture models to assist in creating pre-contoured plates to treat proximal third humeral shaft fractures.MethodsWe retrospectively identified proximal third humeral shaft fractures treated between February 2012 and February 2015. The patients were divided into two groups according to the treatment procedure: a Synbone group and a 3D-printed group. In the Synbone group, long proximal humeral internal locking system plates were pre-contoured into helical shape on Synbones before surgery, while in the 3D-printed group, they were contoured on 3D-printed bone models. The pre-contoured plates were sterilized before surgery and were then used for fracture fixation during surgery. Duration of surgeries, blood loss volumes, the incidence of complications, and the time to fracture union were recorded, and functional outcomes were assessed by the Constant-Murley shoulder score and the Mayo Elbow Performance Score (MEPS) at 1-year follow-up.ResultsThe subjects comprised 46 patients; 25 patients were allocated to the Synbone group and the remaining 21 to the 3D-printed group. There was no significant difference between the baseline characteristics of the two groups. At the 1-year follow-up visit, all fractures were healed and showed a satisfactory outcome. There were no instances of iatrogenic radial nerve injury, and there was no significant difference between the two groups with regard to fracture union time, Constant-Murley score, or MEPS score. Surgery duration was significantly shorter in the 3D-printed group compared to the Synbone group (42.62 vs. 60.36 min, P = 0.001), and the 3D-printed group lost less blood during surgery (105.19 vs. 120.80 ml, P = 0.001). In addition, in the 3D-printed group, 9 surgeries were finished by senior attending doctors and 12 were finished by junior attending doctors; however, there was no significant difference between the 1-year outcomes of the two grades of surgeons.ConclusionsOur results show that the 3D printing technique is helpful in shortening the duration of surgery, reducing blood loss volume, and in making this surgical procedure easier for less-experienced surgeons.Trial registrationThis clinical study was registered in CHICTR on September 30, 2017 (number 17012852).

Biomechanical comparison of screw-based zoning of PHILOS and Fx proximal humerus plates

BackgroundTreatment of proximal humerus fractures with locking plates is associated with complications. We aimed to compare the biomechanical effects of removing screws and blade of a fixed angle locking plate and hybrid blade plate, on a two-part fracture model.MethodsForty-five synthetic humeri were divided into nine groups where four were implanted with a hybrid blade plate and the remaining with locking plate, to treat a two-part surgical neck fracture. Plates’ head screws and blades were divided into zones based on their distance from fracture site. Two groups acted as a control for each plate and the remaining seven had either a vacant zone or blade swapped with screws. For elastic cantilever bending, humeral head was fixed and the shaft was displaced 5 mm in extension, flexion, valgus and varus direction. Specimens were further loaded in varus direction to investigate their plastic behaviour.ResultsIn both plates, removal of inferomedial screws or blade led to a significantly larger drop in varus construct stiffness than other zones. In blade plate, insertion of screws in place of blade significantly increased the mean extension, flexion valgus and varus bending stiffness (24.458%/16.623%/19.493%/14.137%). In locking plate, removal of screw zones proximal to the inferomedial screws reduced extension and flexion bending stiffness by 26–33%.ConclusionsAlthough medial support improved varus stability, two inferomedial screws were more effective than blade. Proximal screws are important for extension and flexion. Mechanical consequences of screw removal should be considered when deciding the number and choice of screws and blade in clinic.

What is the Single Most Important Technical Aspect When Fixing a Proximal Humeral Fracture with A PHILOS Plate?”

Introduction: This study aimed to identify technical factors contributing to hardware complications with PHILOS plates. Methods: A five year retrospective radiological review of all PHILOS platings at our institution was performed. Pathological fractures and revision cases were excluded. (79 patients, 73 females, mean age 88 and range 15-108). AP (Antero-posterior) radiographs were used to assess infero-medial support (presence or absence of calcar screws), adequacy of reduction by measuring the neck-shaft angle, and loss of reduction. The first postoperative radiograph was compared with a follow up radiograph from more than 12 months after the index surgery and cases that required revision were identified. Six patients underwent further surgery for either screw perforation into the joint or plate failure. Cases were then divided into two groups, a revision group (R) and an unrevised group (U), and statistical analysis using Wilcoxon’s rank test for non-parametric data was performed looking at the differences between mean neck shaft angle, adequacy of reduction and loss of reduction in both groups. Results: A clinically and statistically significant difference was found in the mean neck shaft angle between the unrevised and the revised groups. The mean neck shaft angle was 129° in patients who did NOT undergo any further procedures (N = 73). The mean neck shaft angle was 110° in patients who DID undergo revision (N = 10) P <0.03. Conclusion: Restoration of an adequate neck-shaft angle was the most important determinant of successful PHILOS plate fixation. If this was not achieved, screw perforation or plate failure occurred.

Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture.

Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer's type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value< 0.05 is considered significant. Of the 26 patients, all fractures united radiologically and clinically and average constant score at final follow-up was 72.5. At the final follow-up 8 patients had good score, 10 patients had moderate score, 6 patients had excellent outcome and 2 patients had poor outcome according to Constant score. Mean time to union was 12.3 weeks (9 -15 weeks). Four complications (15.4%) were encountered, 2 cases of varus malunion, 1 case of wound infection which required wound debridement and 1 case of screw cut-out in which screw removal was done. Mean constant score in delto splitting approach was 70.9 and 74 in deltopectoral group (p-value= 0.54). No significant difference existed in constant score in 2 approaches. No significant difference existed between groups in terms of complications (P > .05) and all fractures were united. Our study demonstrates that locking plate fixation gives good functional outcomes in treatment of proximal humerus fractures. There was no significant difference in the two approaches used for exposure. Our results are comparable to various studies conducted by other authors which states that locking plates provide better functional and radiological outcomes as compared to other fixation methods like Tension band wiring, percutaneous K-wire fixation, non-locking plates, intramedullary nails.

Augmentation technique on the proximal humerus

The treatment of osteoporotic fractures is still a challenge. The advantages of augmentation with respect to primary in vitro stability and the clinical use for the proximal humerus are presented in this article. In this study six paired human humeri were randomized into an augmented and a non-augmented group. Osteosynthesis was performed with a PHILOS plate (Synthes®). In the augmented group the two screws finding purchase in the weakest cancellous bone were augmented. The specimens were tested in a 3-part fracture model in a varus bending test. The augmented PHILOS plates withstood significantly more load cycles until failure. The correlation to bone mineral density (BMD) showed that augmentation could partially compensate for low BMD. The augmentation of the screws in locked plating in a proximal humerus fracture model is effective in improving the primary stability in a cyclic varus bending test. The targeted augmentation of two particular screws in a region of low bone quality within the humeral head was almost as effective as four screws with twice the amount of bone cement. Screw augmentation combined with a knowledge of the local bone quality could be more effective in enhancing the primary stability of a proximal humerus locking plate because the effect of augmentation can be exploited more effectively limiting it to the degree required. The technique of augmentation is simple and can be applied in open and minimally invasive procedures. When the correct procedure is used, complications (cement leakage into the joint) can be avoided.