Complications and morbidity of the extended delto-pectoral approach in treating complex humeral shaft fractures with proximal metaphyseal extension using a long locking plate for internal fixation.

BACKGROUND: Humeral shaft fractures account for up to 3% of all fractures, but complex forms of those fractures (type AO/OTA B or higher) are rare. Plate and screw fixation of the fracture are rated as consolidated from 80 to 97%. Reported complications include non-union, secondary radial nerve palsy and infection. Minimally invasive plate osteosynthesis (MIPO) should provide the same union rate as open reduction and internal fixation (ORIF) but potentially with fewer complications. The aim of our study was to review patients treated for complex humeral fractures with ORIF through an extended delto-pectoral approach using a long pre-contoured locking plate. The morbidity of the open approach, complication rates, union rate and clinical outcomes were assessed. METHODS: We performed a retrospective analysis of 26 consecutive complex humeral shaft fractures (7 males, mean age 59 years; 19 females, mean age 67 years) treated in our institution with a long pre-contoured locking plate between June/2011 and December/2017. Fracture healing was evaluated with standard radiographs. Eventual complications and the morbidity of the approach were assessed through chart review. The final clinical outcome and quality of life were assessed via telephone interview with DASH score and EQ-5D-3 L in 25 of the 26 patients included. RESULTS: There were no complications related to the open approach with uneventful wound healing in all cases without any infections. Mechanical complications occurred in 3 cases (11%): one tuberosity dislocation (revised) and two plate failures (one revised). Postoperative radial nerve palsy was observed in two patients (7%), of which one was transient, the other was persistent. The plate was removed in 4 cases (15%). The average radiological and clinical follow-up was 21 months (range: 12-56). At 12 months follow-up complete fracture healing was confirmed in 22 out of 26 cases and in three more patients after 18 months. After an average of 44 months, the mean DASH score was 35 (SD ± 15.83) points; the EQ-5D-3 L score 0.7 (SD ± 0.31). CONCLUSION: ORIF with a long locking plate though an extended delto-pectoral approach is certainly still a viable option to treat complex humeral shaft fractures with good soft tissue and bone healing as well as good functional recovery. No increased morbidity was attributed to the open surgical approach. In our series, radial nerve palsy could not be completely avoided, accentuating the potential risk of this specific fracture in close proximity to the radial nerve. TRIAL REGISTRATION: Ethics Committee: Ethikkommission Ostschweiz (EKOS), Project ID: 2019-00323.

Lateral minimally invasive plate osteosynthesis (MIPO) with long PHILOS for proximal metaphyseal-diaphyseal humeral fracture: surgical techniques and a clinical series.

The minimally invasive plate osteosynthesis (MIPO) for proximal metaphyseal-diaphyseal humeral fracture is an effective alternative treatment with satisfactory outcomes. In this study, we described the surgical techniques and clinical results using MIPO via a lateral approach and long PHILOS plate fixation in 23 patients. All fractures were successfully united within a mean union time of 13.5 weeks (range 9-18). There was no iatrogenic radial nerve palsy. The deltoid power was grade 5 in all patients, except for 2 patients who had associated brachial plexus injury and gunshot injury at the deltoid muscle. The mean Constant-Murley score was 85.6 (range 16-98) and DASH score was 12.1 (range 1.7-85). Based on these findings, the lateral MIPO with long PHILOS plate fixation could be an alternative for the proximal metaphyseal-diaphyseal fractures of the humeral shaft.

Comparative study of mechanical performance of various fixation constructs in multifragmentary distal humeral shaft fracture: a finite element analysis.

BACKGROUND: There has been no scientific mechanical assessment demonstrating the optimal fixation technique in multifragmentary fractures of the distal humeral shaft. The purpose of the present study was to compare the biomechanical performance of 5 fixation constructs as used in minimally invasive plating osteosynthesis (MIPO) for distal humeral shaft fractures. METHODS: Three-dimensional (3D) humerus model with 20 mm distal humeral shaft fracture gap simulating multifragmentary fracture was created from computed tomography data and virtually fixed by 5 fixation techniques as MIPO, i.e., anterior narrow dynamic compression plate (DCP), anterior narrow locking compression plate (LCP), anterior reversed proximal humeral internal locking system (R-PHILOS), extra-articular distal humerus locking compression plate (LCP-EADH), and anteromedial LCP. All constructs were biomechanically tested under 6 loading conditions by means of finite element analysis, i.e., 250-N axial compression, 7.5-N m internal rotation, 7.5-N m external rotation, 10-N m posterior bending, 10-N m valgus rotation, and 10-N m varus rotation. In addition, A 3D model of each construct was fabricated as 3D printed models. Fixations were applied to the 3D printing model which were later mechanically tested to validate the FE results. RESULTS: EQV stress exhibited on anterior narrow LCP and anterior R-PHILOS were comparable which were lower than other constructs under axial compression and valgus-varus bending. Anterior R-PHILOS produced lower EQV stress than other constructs under internal-external rotation and posterior bending. On the whole, R-PHILOS demonstrated a comparable fracture displacement to those LCP with anterior or anteromedial approaches, that achieved the lowest displacement values. In addition, the experimental mechanical test values shared a correlation with the FE model results. CONCLUSION: Overall, the anterior R-PHILOS was considered as a potential candidate for multifragmentary distal humeral shaft fractures. It demonstrated efficacious biomechanical performance in terms of implant stress and distal fragment displacement.

Comparison of the ALPS and PHILOS plating systems in proximal humeral fracture fixation - a retrospective study.

BACKGROUND: Open reduction and plate osteosynthesis are considered as a successful technique for the treatment of proximal humerus fracture (PHF) despite high complication rates. The objective of our study was to review the clinical outcome and complications of the Anatomic Locking Plate System (ALPS) and compare it to the Proximal Humeral Internal Locking System (PHILOS). Our hypothesis was that ranges of motion (ROM) were superior and complication rates were lower with ALPS. METHODS: Twenty patients treated with ALPS for PHF were retrospectively compared to 27 patients treated with PHILOS. Union, ROM and complications were clinically and radiologically assessed at 6 weeks, 3, 6, 12 and 18-24 months post-operatively. RESULTS: Mean age was 52 ± 14 in the ALPS group and 58 ± 13 in the PHILOS group. Last follow-ups were conducted at a mean of 20.6 ± 4.8 months. Mean shoulder abduction was superior with ALPS by 14° (p-value = 0.036), 15° (p-value = 0.049), and 15° (p-value = 0.049) at 3, 6, and 12 months respectively. Mean shoulder external rotation was superior with ALPS by 11° (p-value = 0.032), 15° (p-value = 0.010) and 12° (p-value = 0.016) at 6 weeks, 3 and 6 months respectively. At the end of the follow-up, ROM remained better with ALPS, but not significantly. Complication rates over 21 months reached 20% with ALPS and 48% with PHILOS (p-value = 0.045). Implant removal rates reached 10% with ALPS and 37% with PHILOS (p-value = 0.036). Avascular necrosis was the only cause for hardware removal in the ALPS group. CONCLUSION: The ALPS group showed better clinical outcomes with faster recovery in abduction and external rotation, although no difference in ROM remained after 21 months. Additionally, the complications rate was lower at last follow up. In our experience, the ALPS plating system is an effective management option in some PHF.

Intraoperative 3D imaging in plate osteosynthesis of proximal humerus fractures.

INTRODUCTION: Proximal humerus fractures are common and often associated with osteoporosis in the elderly. Unfortunately, the complication and revision rate for joint-preserving surgical treatment using locking plate osteosynthesis is still high. Problems include insufficient fracture reduction and implant misplacement. Using conventional intraoperative two dimensional (2D) X-ray imaging control in only two planes, a completely error-free assessment is not possible. MATERIALS AND METHODS: The feasibility of intraoperative three-dimensional (3D) imaging control for locking plate osteosynthesis with screw tip cement augmentation of proximal humerus fractures was retrospectively studied in 14 cases with an isocentric mobile C-arm image intensifier set up parasagittal to the patients. RESULTS: The intraoperative digital volume tomography (DVT) scans were feasible in all cases and showed excellent image quality. One patient showed inadequate fracture reduction in the imaging control, which then could be corrected. In another patient, a protruding head screw was detected, which could be replaced before augmentation. Cement distribution in the humeral head was consistent around the screw tips with no leakage into the joint. CONCLUSION: This study shows that insufficient fracture reduction and implant misplacement can be easily and reliably detected by intraoperative DVT scan with an isocentric mobile C-arm set up in the usual parasagittal position to the patient.

Modified use of the proximal humeral internal locking system (PHILOS) plate for distal femoral nonunions.

PURPOSE: Nonunion is a common complication after a distal femoral fracture (DFF). Standard treatment consists of revision plating and/or bone grafting. Single lateral plating for a distal femoral nonunion can be insufficient in case of a persistent medial gap and compromised bone stock. Alternatively, dual plating can be used to treat a distal femoral nonunion, but to date there is no Gold standard. The aim of our study was to report our results after use of a minimally invasively placed proximal humeral internal locking system (Philos) plate as a medial buttress in the treatment of a distal femoral nonunion. METHODS: Fifteen adult patients with a distal femoral nonunion were prospectively entered in a trauma database and retrospectively assessed. All patients underwent a similar operation, which included removal of failed hardware, nonunion debridement, fixation with a lateral plate, and a medial Philos plate combined with bone grafting. Data collected included union rate, time to union, complications and functional outcome. RESULTS: In twelve out of fifteen patients (80%), the fracture united after our index operation. Median time to union was 4.8 months (range 1.6-15). Three patients (20%) needed additional bone grafting surgery. One patient underwent a Judet quadricepsplasty. CONCLUSION: This study suggests that the Philos plate is a safe and effective adjunct as a medial buttress plate for distal femoral nonunions.

A cost-effectiveness analysis of reverse total shoulder arthroplasty compared with locking plates in the management of displaced proximal humerus fractures in the elderly: the DelPhi trial.

AIM: To evaluate the cost-effectiveness of surgical treatment with reverse total shoulder arthroplasty (RTSA) compared with open reduction and internal fixation (ORIF) with a locking plate for patients 65-85 years old with a displaced proximal humerus fracture. METHODS: A cost-utility analysis was conducted alongside a multicenter randomized controlled trial, taking a health care perspective. A total of 124 patients with displaced proximal humerus fractures were randomized to treatment with RTSA (n = 64) or ORIF (n = 60) during a 2-year period. The outcome measure was quality-adjusted life years derived from the generic questionnaire 15D in an intention to treat population. The results were expressed as incremental cost-effectiveness ratios, and a probabilistic sensitivity analysis was performed to account for uncertainty in the analysis. RESULTS: At 2 years, 104 patients were eligible for analyses. The mean quality-adjusted life year was 1.24 (95% confidence interval: 1.21-1.28) in the RTSA group and 1.26 (95% confidence interval: 1.22-1.30) in the ORIF group. The mean cost in the RTSA group (€36.755 [€17,654-€55,855]) was higher than that in the ORIF group (€31.953 [€16,226-€47,279]). Using incremental cost-effectiveness ratio, ORIF was the dominant treatment. When using a probabilistic sensitivity analysis with 1000 replications, the plots were centered around origo. This indicates that there is no significant difference in cost or effect. CONCLUSION: In the cost-utility analysis of treatment of displaced proximal humeral fractures, there were no differences between RTSA and ORIF.

Comparison between anterior and posterior plating systems in extra-articular distal-third diaphyseal humeral fractures.

PURPOSE: The ideal surgical treatment of extra-articular distal-third diaphyseal humeral fractures is controversial in terms of the surgical approach and plate position. The aim of this study was to compare the clinical and radiological outcomes between anterior and posterior plating methods for extra-articular distal-third diaphyseal humeral fractures. METHODS: Twenty-four patients were treated with anterior plating with modified placement of the proximal humeral internal locking system (PHILOS) plate, and 22 patients were treated with posterior plating of the extra-articular distal humerus plate (EADHP). Patient demographics, the fracture configuration, the number of screws in the distal fragment, the operation time, and the time to union were analyzed. The range of elbow motion, Mayo elbow performance score (MEPS), plate-related symptoms, and complications were evaluated at the final follow-up. RESULTS: There were no statistically significant differences in the demographic data between the two groups. The mean operation time for anterior plating (108.2 ± 24.5 min) was significantly shorter than that for posterior plating (144.2 ± 29.5 minutes, p < 0.001). The average number of screws used in the distal humeral fragment was significantly higher with anterior plating (5.7 ± 0.7) than with posterior plating (4.8 ± 0.5, p < 0.001). No patients in the anterior plating group had plate-related symptoms, while 17 patients in the posterior plating group (77%) had discomfort or cosmetic problems related to the plate (p < 0.001). Plate removal was performed upon patient request in nine patients of the posterior plating (52.9%) and four (17%) in anterior plating (p = 0.040). Nonunion occurred in one patient who underwent anterior plating, and one patient who underwent posterior plating had post-operative radial nerve palsy. There were no significant differences in the MEPS or elbow range of motion between the two surgical methods. CONCLUSION: Both anterior and posterior plating provide satisfactory clinical and radiologic outcomes for extra-articular distal-third diaphyseal humeral fractures. Despite the satisfactory outcomes, however, posterior plating is highly associated with plate-related complaints, which might be one of the considerations when the surgical method is selected for extra-articular distal-third diaphyseal humeral fractures.

Reduction and fixation of proximal humeral fracture with severe medial instability using a small locking plate.

BACKGROUND: Currently, the reduction and support of comminuted medial cortex of humeral fracture remains a challenge, Therefore, a novel reduction and fixation technique that employs an anteromedial small locking plate was explored in this study, and its viability and the associated complications were assessed. METHODS: Fifteen cases of proximal humeral fractures with medial instability (five cases were classified as three-part and ten as four-part by Neer classification) were treated by the proposed reduction technique using an anteromedial small locking plate. Subsequently, the radiological and clinical outcomes were evaluated over an average follow-up period of 18.53 months. RESULTS: The average operation time was 108 min (range, 70-130 min), and the mean fracture union time in all patients was 12.13 weeks (range, 8-16 weeks). Complications such as infection and neurovascular injury were not observed. Postoperative X-ray showed avascular necrosis and screw penetration in one patient, while screw penetration, varus malunion, or significant reduction loss was not found in the other cases. The mean Constant score was 79.8 (range, 68-92) during the final visit. CONCLUSIONS: The use of an anteromedial small locking plate improved the reduction efficiency, reconstructed the medial support, and alleviated the occurrence of complications in proximal humeral fractures with medial instability.

Shoulder function after helical long PHILOS plate.

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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 OF EVIDENCE: Level 3, Retrospective Cohort Study.

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.

BACKGROUND: 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. METHODS: 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 3 months. RESULTS: 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). CONCLUSION: 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 OF EVIDENCE: Level 3, retrospective cohort study.

[The PHILOS plate-also an indication for osteosynthesis of the distal tibia?] / Die PHILOS-Platte ­ auch an der distalen Tibia eine Indikation zur Osteosynthese?

According to the manufacturer's instructions the application of a PHILOS plate is restricted to humeral fractures. An extension to other anatomical regions of the body is not provided; however, based on the anatomical design of the plate it was observed that the application of this plate also appears to be possible for the distal tibia. This article reports three different osteosyntheses by a reverse PHILOS plate on the medial malleolus and on the distal tibia posteriorly with a short and a long PHILOS plate design. In summary, the applications have so far resulted in primary wound healing with correct consolidation of the fractures.

Anterior minimally invasive plating osteosynthesis using reversed proximal humeral internal locking system plate for distal humeral shaft fractures.

OBJECTIVE: To describe the surgical application of anterior minimally invasive plating osteosynthesis (MIPO) using reversed proximal humerus internal locking system (PHILOS) plate for multifragmentary distal humeral shaft fractures. METHODS: Twelve patients with distal humeral shaft fractures (type 12B, n = 6 and type 12C, n = 6) were operated on by anterior MIPO and reversed PHILOS plate fixation. The amount of intact bone in the distal fragment was measured by fracture-to-coronoid distance (FCD). Data of the postoperative alignment, complications, union time, and clinical outcomes were collected. RESULTS: The mean time for fractures to unite in all patients was 14.8 weeks (range 12-22). There was no perioperative complication. The mean FCD was 4.8 cm (range 2.1-8.1). The mean coronal angulation was 3.4° (range 0-9), and the mean sagittal angulation was 1° (range 0-5). All patients had excellent UCLA shoulder score and MEP score results, and the mean range of elbow motion was 140° (range 130-145). CONCLUSION: Anterior MIPO using reversed PHILOS plate is safe and effective for multifragmentary fractures of the distal humeral shaft even in a fracture with a length of intact bone above the coronoid fossa of only 2 cm.

Narrow locking compression plate vs long philos plate for minimally invasive plate osteosynthesis of spiral humerus shaft fractures.

BACKGROUND: Our hypothesis was that minimally invasive plate osteosynthesis (MIPO) using long philos plate (LPP) would show better clinical and radiological outcomes and less complications than narrow locking compression plate (NLCP) for spiral humerus shaft fractures with or without metaphyseal fracture extension. METHODS: From January 2009 to May 2016, we retrospectively studied 35 patients who underwent MIPO for spiral humerus shaft fractures with or without metaphyseal fracture extension (AO classification 12 A, B, C except A3). Eighteen patients underwent MIPO with a 4.5 mm NLCP (group I) in the early period of this study, while 17 patients underwent MIPO with LPP (group II) in the later period. Range of motion (ROM), pre- and post-operative anteroposterior (AP) and lateral angulation of the fracture, operation time, amount of bleeding, and functional outcomes including American Shoulder and Elbow Surgeons score, University of California at Los Angeles score, and Simple Shoulder Test score were analyzed at the final follow up. RESULTS: All patients had complete bony union and achieved satisfactory functional outcomes except 2 patients. In LPP group, better outcomes in postoperative fracture angulation on X-ray and operation time (p < 0.05) were shown. But, two revision surgery with NLCP and bone graft was performed owing to 2 metal failures. CONCLUSIONS: In spiral humeral shaft fractures, LPP group showed better fracture reduction on X-ray and shorter operation time except metal failure owing to weak fixation. Even though MIPO technique using LPP is easier and more accurate reduction method, rigid fixation should be considered.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

A new risk to the axillary nerve during percutaneous proximal humeral plate fixation using the Synthes PHILOS aiming system.

BACKGROUND: Percutaneous aiming arms have been developed to minimize injury during placement of submuscular proximal humerus plates. The purpose of this study was to determine the risk of axillary nerve injury during percutaneous proximal humeral plate fixation using the Synthes PHILOS aiming system. METHODS: By use of 10 fresh-frozen cadavers (20 shoulders), a 3.5-mm locking compression proximal humeral plate was fixated percutaneously to the humerus through a lateral deltoid-splitting approach using the PHILOS aiming guide. Dissection of the axillary nerve was then carried out, and measurements of its relation to the screw holes in row A through row G of the plate were taken. The lateral acromion-to-axillary nerve distance was also measured. RESULTS: The axillary nerve traversed row D in every shoulder, whereas it crossed over row C in 11 shoulders and both holes in row E in 16 shoulders. The closest distance to the axillary nerve achieved was 4.5 mm, corresponding to the distal (left) screw in row B. A significant negative correlation was found for the distance from the nerve to the closest proximal and distal screws (row B and row G, respectively) in both right shoulders (ρ = -0.797; 95% confidence interval, -0.916 to -0.548) and left shoulders (ρ = -0.615; 95% confidence interval, -0.831 to -0.237). CONCLUSION: The axillary nerve traverses rows C, D, and E of the proximal humeral plate using the PHILOS aiming system. Importantly, our study is the first to demonstrate that the axillary nerve crosses over row C. Left-sided plate screws also came in closer proximity to the axillary nerve than right-sided plate screws.

Long-term follow-up after MIPO Philos plating for proximal humerus fractures.

INTRODUCTION: Minimally invasive plate osteosynthesis (MIPO) has been described as a suitable technique for the treatment of proximal humerus fractures, but long-term functional results have never been reported. The aim of this study was to describe the long-term functional outcome and implant-related irritation after MIPO for proximal humerus fractures. METHODS: A long-term prospective cohort analysis was performed on all patients treated for a proximal humerus fracture using MIPO with a Philos plate (Synthes, Switzerland) between December 2007 and October 2010. The primary outcome was the QuickDASH score. Secondary outcome measures were the subjective shoulder value (SSV), implant related irritation and implant removal. RESULTS: Seventy-nine out of 97 patients (81%) with a mean age of 59 years were available for follow-up. The mean follow-up was 8.3 years (SD 0.8). The mean QuickDASH score was 5.6 (SD 14). The mean SSV was 92 (SD 11). Forty out of 79 patients (50.6%) had implant removal, and of those, 27/40 (67.5%) were due to implant-related irritation. On average, the implant was removed after 1.2 years (SD 0.5). In bivariate analysis, there was an association between the AO classification and the QuickDASH (p = 0.008). CONCLUSION: Treatment of proximal humerus fractures using MIPO with Philos through a deltoid split approach showed promising results. A good function can be assumed due to the excellent scores of patient oriented questionnaires. However, about one-third of the patients will have a second operation for implant removal due to implant-related irritation.

Cement augmentation of the proximal humerus internal locking system in elderly patients: a multicenter randomized controlled trial.

INTRODUCTION: Cement augmentation of the proximal humerus internal locking system (PHILOS) screws might reduce complication rates in osteoporotic bones. This study compared the risk of mechanical failure during the first year after PHILOS™ treatment of proximal humerus fractures (PHF) without (control group) and with (augmented group) screw augmentation. Secondary objectives were to report shoulder functions, quality of life (QoL), adverse events (AEs), and reoperation rates. MATERIALS AND METHODS: This multicenter randomized trial enrolled patients aged ≥ 65 years with displaced/unstable PHF from eight European centers. Randomization was performed during surgery through sealed opaque envelopes. Mechanical failures were assessed by two independent reviewers via radiographs, shoulder function by Quick DASH, SPADI, and Constant Murley scores, and QoL by EQ-5D. Follow-ups were planned at postoperative 6 weeks, 3, 6, and 12 months. RESULTS: The preliminary analysis of 6-week radiographs of the first 59 enrolled patients suggested a mechanical failure rate lower than expected and the difference between groups was too small to be detected by the planned sample size of 144. The trial was prematurely terminated after 67 patients had been enrolled: 34 (27 eligible) in the control group and 33 (29 eligible) in the augmented group. Follow-ups were performed as planned. Nine patients had mechanical failures and the failure rates (95% CI) were: augmented group, 16.1% (5.5; 33.7); control group, 14.8% (4.2; 33.7); the relative risk (95% CI) for the augmented group was 1.09 (0.32; 3.65) compared to the control group (p = 1.000). No statistically significant differences in shoulder function, QoL, and AEs were observed between study groups at 1 year. Nine patients (15.8%) underwent a revision. CONCLUSIONS: Due to premature termination, the study was underpowered. A larger study will be necessary to determine if cement augmentation lowers the risk of mechanical failure rate.

The influence of screw length on predicted cut-out failures for proximal humeral fracture fixations predicted by finite element simulations.

BACKGROUND: The aim of this study was to identify the effect of screw length on predictions of fixation failure in three-part proximal humeral fractures using a finite element-based osteosynthesis modelling toolkit. METHODS: A mal-reduced unstable three-part AO/OTA 11-B3.2 fracture with medial comminution was simulated in forty-two digitally processed proximal humeri covering a spectrum of bone densities and fixed with the PHILOS plate using three distal and six proximal locking screws. Four test groups were generated based on the screw tip to joint surface distance (TJD), with all proximal screws being shortened from 4 mm TJD to be 8, 12 or 16 mm TJD. Average bone strains around the screw tips, correlating with biomechanical cyclic cut-out-type failure, were evaluated in three physiological loading protocols representing simple shoulder motions. Six further groups were tested, where five of the proximal screws were inserted to 4 mm TJD and the sixth screw to 8 mm TJD. RESULTS: Exponential increases in the predicted risk of fixation failure were seen with increased tip-to-joint distances (p < 0.001). When one of the proximal screws was placed 8 mm from the joint, with the remaining five at 4 mm distance, significant increases (p < 0.001) were registered in the strains around the screw tips in all except the two superior screws. This effect was maximal around the calcar screws (p < 0.001) and for lower density samples (p < 0.001). CONCLUSIONS: These results suggest that longer screws provide reduced risk of cut-out failure, i.e. distalisation and/or varisation of the head fragment, and thus may decrease failure rates in proximal humeral fractures treated with angular stable plates. These findings require clinical corroboration and further studies to investigate the risk of screw perforation.

Titanium mini locking plate with trans-osseous sutures for the treatment of humeral greater tuberosity fracture osteosynthesis versus PHILOS: a retrospective view.

PURPOSE: Greater tuberosity fractures (GTFs) account for 17 to 21% of proximal humerus fractures, most of these fractures are treated conservatively, but treatment for displaced fractures is still controversial. The aim of this study is to compare intra-operative clinical conditions and post-operative outcomes when displaced GTFs are treated with either proximal humeral internal locking system (PHILOS) or mini locking plate with trans-osseous sutures. METHODS: This is a retrospective study conducted in Shanghai Tenth People's Hospital. A total of 60 patients (22 males and 38 females) with displaced humeral GTF between May 2013 and March 2017 were included, of whom 43 underwent PHILOS implant treatment and 17 underwent titanium mini plate implant with trans-osseous suture treatment. Intra-operative (incision size, intra-operative blood loss, operative duration) and postoperative (Constant-Murley score (CMS) and implant cost) variables were recorded for the comparison. RESULTS: Mini locking plate with trans-osseous sutures shows better results. Operative duration (PHILOS mean 77.0 minutes vs mean 63.7 minutes, p value < 0.05), blood loss during surgery (PHILOS mean 111.5 vs 66.5 ml, p value < 0.05), incision size (PHILOS mean 7.2 vs 4.6 cm, p value < 0.05), CMS (PHILOS mean 81.0 vs 87.3, p value < 0.05), and implant costs (PHILOS mean 26,192.6 renminbi (RMB) vs mean 21,358.8 RMB, p value < 0.05). On the other hand, 9.30% of impingement in the PHILOS group was observed to have no complications compared to the mini locking plate group. CONCLUSIONS: Mini locking plate with trans-osseous sutures shows better efficacy in reducing the incision size, operative duration, intraoperative blood loss, and implant cost and in improving CMS. No complication was found with its use. Our data can provide rationale and inform sample- size calculations for such studies. Larger, control studies are needed for better understanding.