Results of 131 consecutive operated patients with a displaced proximal humerus fracture: an analysis with more than two years follow-up

Reverse shoulder arthroplasty for proximal humerus fractures and reverse shoulder arthroplasty for elective indications should have separate Current Procedural Terminology (CPT) codes

BACKGROUND

Reverse shoulder arthroplasty (RSA) for fracture currently shares a single Current Procedural Terminology (CPT) code with RSA for arthropathy despite potential differences in patient factors, procedural demands, postoperative care and needs, and overall hospital systems' resource utilization. We hypothesize that patients indicated for RSA for fracture will have greater medical complexity, require longer operative duration, have higher complication rates, demonstrate inferior functional outcomes, and require greater health care cost expenditures compared to a cohort undergoing RSA for rotator cuff arthropathy.

METHODS

A total of 383 RSAs were retrospectively reviewed from January 2011 to December 2020. Demographics, comorbidities, operative time, financial charge and cost data, length of stay (LOS), discharge disposition, and all-cause revisions were assessed. Visual analog scale (VAS) pain score and active range of motion (AROM) were evaluated at 2, 6, and 12 months postoperatively.

RESULTS

After exclusions, 197 total RSAs were included, with 28 for fracture and 169 for arthropathy indications. RSA operative time was longer for fractures with an average of 143.2 ± 33.7 minutes compared with 108.2 ± 33.9 minutes for arthropathy (P = .001). Average cost per patient for RSA for proximal humerus fracture was $2489 greater than the cost for RSA for elective indications; however, no statistically significant difference was noted between average costs (P = .126). LOS was longer for RSA for fracture compared to arthropathy, with a mean of 4.0 ± 3.6 days vs. 1.8 ± 2.3 days (P = .004). The fracture group was 3.6 times more likely to be discharged to a skilled nursing facility or inpatient rehabilitation (32% vs. 9%, P = .002). Early and late all-cause revisions were similar between groups. Differences in postoperative AROM for fracture vs. arthropathy were significant for active forward flexion at 2 months (95.5° ± 36.7° vs. 117.0° ± 32.3°, P = .020) and 6 months (110.9° ± 35.2° vs. 129.2° ± 28.3°, P = .020) as well as active adducted external rotation at 6 months (20.0° ± 20.9° vs. 33.1° ± 12.3°, P = .007) and at 12 months (23.3° ± 18.1° vs. 34.5° ± 13.8°, P = .012). No difference in VAS pain scores were noted between fracture and arthropathy groups at any time point.

DISCUSSION

RSA for fractures vs. arthropathy have substantial differences in patient characteristics, surgical complexity, and hospital resource utilization. This is of importance given the currently available CPT code does not differentiate indications for RSA, especially if intending to accurately document the surgical care delivered.

Lateral Wall Integrity of the Greater Tuberosity Is Important for the Stability of Osteoporotic Proximal Humeral Fractures After Plate Fixation

BACKGROUND

Previous studies assessing surgical fixation of osteoporotic proximal humeral fractures have primarily focused on medial calcar support. In this study, we utilized a specific model for 2-part surgical neck fracture of the osteoporotic proximal humerus to investigate how severe comminution of the greater tuberosity (GT) lateral wall affects biomechanical stability after fixation with a plate.

METHODS

Ten matched pairs of cadaveric humeri (right and left) were assigned to either a surgical neck fracture alone (the SN group) or a surgical neck fracture with GT lateral wall comminution (the LW group) with use of block randomization. We removed 5 mm of the lateral wall of the GT to simulate severe comminution of the lateral wall. Axial compression stiffness, torsional stiffness, varus bending stiffness, and the single load to failure in varus bending were measured for all plate-bone constructs.

RESULTS

Compared with the SN group, the LW group showed a significant decrease in all measures, including torsional stiffness (internal, p = 0.007; external, p = 0.007), axial compression stiffness (p = 0.002), and varus bending stiffness (p = 0.007). In addition, the mean single load to failure in varus bending for the LW group was 62% lower than that for the SN group (p = 0.005).

CONCLUSIONS

Severe comminution of the GT lateral wall significantly compromised the biomechanical stability of osteoporotic, comminuted humeral surgical neck fractures.

CLINICAL RELEVANCE

Although the generalizability of this cadaveric model may be limited to the extreme clinical scenario, the model showed that severe comminution of the GT lateral wall significantly compromised the stability of osteoporotic humeral surgical neck fractures fixed with a plate and screws alone.

The POSI study: gender differences in 94 cases of postoperative shoulder surgery infection: results of a 7-year retrospective multicenter study

BACKGROUND

Contrary to lower limb infection, POstoperative Shoulder surgery Infection (POSI) often involves Cutibacterium acnes. Our aim was to describe patient characteristics and pathogens retrieved in POSI to guide initial empiric antibiotic selection with suspected infection during revision. We also compared microorganisms in infection following trauma, arthroplasty (AP), and arthroscopy (AS).

METHODS

A multicenter retrospective study from 2010 to 2016 reviewed laboratory databases and medical records to identify patients with a previous shoulder surgery and a confirmed shoulder infection. The following procedures were included: AP, AS, fracture fixation (FF), and another open surgery (OS). A confirmed shoulder infection was defined as 2 positive cultures or more of the same microorganism, or clear clinical infection with 1 positive culture or more.

RESULTS

Among the 5 hospitals and 28 surgeons involved, 94 POSI cases were identified. Mean age was 59 years at index surgery (range: 22-91) with a majority of men (n = 70, 74%). Among POSI cases, AP was the most common index surgery (n = 41), followed by FF (n = 27), AS (n = 16), and OS (n = 10). The median time between index surgery and the first positive sample was 5 months and the mean was 23 months (minimum 6 days to maximum 27 years), illustrating a positively skewed distribution. Cutibacterium spp were identified in 64 patients (68%), including 59 C acnes patients (63%), which was the most frequent germ in all 4 surgical groups. In 86% of cases, C acnes was identified at the first revision. The other 2 most common germs were Staphylococcus epidermidis and Staphylococcus aureus, with 29% and 17%, respectively. Polymicrobial infection was present in 30% of patients. Gender analysis revealed that C acnes was twice as frequent in men (male = 52 of 70, female = 7 of 24; P < .001). S epidermidis was more prevalent in women (n = 11; 46%) compared with men (n = 16; 21%) (P = .032). C acnes infection was most frequent in arthroscopic surgery (n = 14; 70%, P = .049). S epidermidis was 3 times more prevalent in chronic than in acute cases.

CONCLUSION

Empiric antimicrobial therapy following POSI, while waiting for culture results, should cover C acnes, S epidermidis, and S aureus. There is a significant gender difference regarding POSI culture results. C acnes is more frequent in men, but should still be covered in women as it was found in 29% of cases.

Endosteal plating in proximal humerus fractures: a novel technique and alternative to fibular strut allograft for medial column support

Hypothesis

The purpose of this retrospective study is to investigate the clinical and radiographic outcomes associated with the use of a standard metal plate as an endosteal implant in combination with a lateral locking plate to treat 4 patients with displaced proximal humerus fractures.

Methods

A retrospective case series study design was utilized, and the medical records of 4 patients with displaced, 3-part proximal humerus fractures treated using this technique between January 2019 and July 2021 were reviewed for this study. The mean age was 52 years (range, 44-57 years). The radiographic outcome of interest was humeral neck-shaft angle preoperatively, intraoperatively, and at the latest follow-up. The average follow-up duration was 62 weeks (range, 12-161 weeks).

Results

All fractures healed without loss of reduction or neurovascular deficits. Avascular necrosis was not observed in the 2 patients with sufficient follow-up time to make such an evaluation. The average neck-shaft angles preoperatively, intraoperatively, and at the latest follow-up were 104.8°, 139.8°, and 137°, respectively.

Conclusion

Locking plate technology augmented with an endosteal plate provided stable reduction and restoration of physiologic alignment in a small number of patients with displaced proximal humerus fractures. This construct creates a second column of fixation, providing medial column support, and could be removed in the event of a future revision to a reverse shoulder arthroplasty.

A bibliometric analysis of clinical research on fracture-related infection

Background. Infection following orthopaedic trauma surgery is increasingly recognized as one of the major research priorities with as primary goal, improving patient care. This increased interest has been anecdotally recognized through published research, research grants, and, finally, with the development of the fracture-related infection (FRI) consensus group. In 2017, the accepted consensus definition of FRI was published, which has been followed by consensus recommendations from both a surgical and medical perspective. A bibliometric analysis was performed to objectively describe the trends in published clinical research related to FRI. Methods. The terms related to FRI were searched in the Web of Science database between 2000 and 2020. The characteristics of clinical research on FRI regarding the author, country, journal, institution, scientific output, top 100 most cited articles, and trend topics were analyzed using Bibliometrix and WPS Office. Results. A total of 2597 records were eligible for inclusion in this bibliometric approach, with studies originating from 89 countries, including eight languages. The United States of America (USA) published the highest number of articles and citations. International collaborations were present between 72 countries, with the most active country being the USA. The most contributive institution was the University of California. The highest number of papers and citations were from the Injury-International Journal of the Care of the Injured and the Journal of Orthopaedic Trauma. The top 100 most cited articles were published in 27 different journals, with the number of citations ranging between 97 and 1004. The latest trend topics were related to the diagnosis of FRI. Conclusion. The present bibliometric analysis shows the research characteristics and trends of FRI from multiple perspectives. The fact that there is an increasing number of studies being published on FRI shows the agreement among scientists and clinicians that standardization with respect to this topic is very important.

PHILOS Synthesis for Proximal Humerus Fractures Has High Complications and Reintervention Rates: A Systematic Review and Meta-Analysis

Purpose: The aim of this study was to quantify the rate of complications and reinterventions in patients treated with PHILOS plate for proximal humerus fractures (PHFs) synthesis. Methods: A comprehensive literature search was performed on the PubMed, Web of Science, Embase, and Cochrane databases up to 7 October 2021. Studies describing medium and long-term complications in PHF synthesis using the PHILOS plate were included. A systematic review and meta-analysis were performed on complications and causes of reinterventions. Assessment of risk of bias and quality of evidence was performed with the Downs and Black’s “Checklist for Measuring Quality”. Results: Seventy-six studies including 4200 patients met the inclusion criteria. The complication rate was 23.8%, and the main cause was screw cut-out (4.1%), followed by avascular necrosis (AVN) (3.1%) and subacromial impingement (1.5%). In patients over 55 years, the complication rate was 29.5%. In the deltopectoral (DP) approach the complication rate was 23.8%, and in the delto-split (DS) it was 17.5%, but no difference between the two approaches was seen when considering the type of fracture. The overall reintervention rate was 10.5% in the overall population and 19.0% in older patients. Conclusions: Proximal humerus synthesis with a PHILOS plate has high complications and reintervention rates. The most frequent complication was screw cut-out, followed by humeral head AVN and subacromial impingement. These results need to be further investigated to better understand both the type of patient and fracture that is more at risk of complications and reintervention and to compare pros and cons of the PHILOS plate with respect to the other solutions to manage PHFs.

Management of Posttraumatic Avascular Necrosis of the Proximal Humerus

The etiology of avascular necrosis (AVN) of the proximal humerus can be classified as idiopathic or posttraumatic, the latter being mainly due to proximal humerus fractures. Evidence suggests that posttraumatic AVN may require surgical intervention more often than idiopathic AVN of the proximal humerus. This article provides a comprehensive review of the management of posttraumatic AVN of the proximal humerus. Early stage AVN (stages 1 to 3) is commonly treated with nonoperative intervention or core decompression of the humeral head, whereas later stage disease (stages 4 and 5) may require hemiarthroplasty or total shoulder arthroplasty to restore function. [Orthopedics. 2021;44(6):367-375.].

Three-part humeral head fractures treated with a definite construct of blocked threaded wires: finite element and parametric optimization analysis

Background

Mini open reduction and percutaneous fixation of three-part humeral head fracture with blocked threaded wires has demonstrated functional results similar to locking plates or intramedullary nails but with significantly lower major complication rate. In the context of three-part humeral head fractures, we performed a parametric optimization through a finite element analysis of a recently published construct to verify if the encouraging clinical results can be supported by a more rigorous investigation from a mechanical viewpoint.

Materials and Methods

The 2-dimensional geometry of a three-part proximal humerus fracture synthetized with a system of blocked threaded wires was created. Tension/bending/shear and compression load tests were simulated. A parametric optimization analysis was performed considering four design parameters (height of wire couples; wire material; interdistance between two wires). Eighteen simulations were carried out. Additional analyses were performed also considering a varying diameter of the external rod.

Results

Four points where the largest gap occurs and three points associated with the highest stress concentration were considered. As per the tension/bending/shear loading, a slight gap increase was observed in two different points (8.494 μm; 7.540 μm), while a slight decrease was detected along the greater tuberosity fracture line (1.445 μm). The maximum von Mises stress up to 64.4 MPa was achieved in the humeral head. As per the compression loading, the gap increased along the greater tuberosity fracture line (1.445 μm; 7.545μm); the maximum von Mises stress attains the value of 64.42 MPa. The smallest gap distance (15.37μm) and the lowest von Mises stress (51.51 MPa) were obtained in two different alternative constructs. The diameter of the external rod had no significant effect.

Conclusions

The studied construct is biomechanically valid; it only allows micromovements (one-thousandth of the characteristic humerus size) that are not able to cause humeral head rotation and translation. Furthermore, the construct generates acceptable pressure stresses on sensible areas of the fractured humeral head. Compared to the original construct, we propose to space the pair of horizontal wires for the great tuberosity by at least 1 cm.

Screw placement in two different implants for proximal humeral fractures regarding regional differences in bone mineral density: An anatomical study

BACKGROUND

The aim of this study was to investigate proximal humerus plating regarding drill depth and over penetration of the glenohumeral joint and to find a relation between these findings and different areas of bone mineral density (BMD) in the humeral head.

MATERIAL & METHODS

The study sample involved 45 upper extremities from human adult cadavers. Two different plates (HOFER; PHILOS) were applied to the proximal humerus. Each hole was drilled until the respective participant thought to have placed the drill bit subchondral. Next, penetration of the far cortex was conducted to determine the residual bone stock. Additionally, the point of screw penetration of the far cortex was identified for each hole of the plates and allocated to five regions with different bone mineral density as described by Tingart et al.

RESULTS

The screw penetration rate and the residual bone stock were compared within the 5 BMD regions. A significantly thicker residual bone stock was found at the central region (SD ± 13.1 mm) than in the anterior region (SD ± 9.5 mm) and in the posterior region (SD ± 8.5 mm). The anterior region revealed a significantly higher penetration rate than the posterior region (p = 0.01) and the central region (p = 0.03).

CONCLUSION

The anterior region of the humeral head was associated with a higher over penetration rate of the far cortex into the glenohumeral joint and a decreased bone stock after subchondral drilling representing a reduced bone mineral density (BMD).

LEVEL OF EVIDENCE

Cadaver Study.

A New Surgical Technique and Clinical Outcomes of Operated Proximal Metadiaphyseal Humeral Fractures and Nonunions With the Use of Reversed Anatomic Distal Femoral Locking Plate

Introduction Proximal humeral fractures complicated with metaphyseal and diaphyseal extension are usually treated operatively with 3.5 mm long anatomic proximal humerus plates. However, frequently these comminuted and segmental fracture types may be associated with delayed union, nonunion, and/or plate failure. We present a technique for addressing this fracture pattern by using an anatomic contralateral 4.5 mm distal femoral plate in a reversed fashion. Methods Eleven patients (eight women and three men) with a mean age of 70 years (range, 52 to 84 years) were operated on with the described technique. The dominant hand was involved in seven out of 11 patients. There were seven acute metadiaphyseal fractures and four nonunions. In one patient, humeral shaft nonunion was associated with segmental metadiaphyseal defect and a free fibular graft was applied. Results All fractures healed and patients regained almost normal function of the affected shoulder and upper limb. Shoulder abduction and forward elevation ranged from 80 to 110 degrees (mean, 97 degrees) and 90 to 120 degrees (mean, 102 degrees), respectively. The disabilities of the arm, shoulder and hand (DASH) score varied from 6 to 11 points (median 8). No major trauma or systemic complications were recorded. Conclusion The morphology, strength, and characteristics of the plate could effectively conform to the anatomy of the proximal humerus and offer adequate stability for fracture union. The described technique is more useful in case of osteoporosis and/or presence of previous failed internal fixation that further compromise the vascularization and the mechanical properties of the bone.

Preliminary clinical and radiographic outcomes of proximal humeral fractures: comparison of ALPS and PHILOS plating in Asian patients in Taiwan

Background

Up to 20% of proximal humeral fractures need to be treated operatively. However, numerus complications were reported by using fixed angled locking plates. The ALPS Proximal Humerus Plating System is a new design implant with novel design features.

The aim of this study was to compare the preliminary clinical outcomes and complications of proximal humeral fractures treated with either ALPS or the proximal humeral internal locking system (PHILOS) in Asian patients in Taiwan.

Methods

Between January 2016 and December 2018, 66 patients with displaced proximal humeral fractures were analyzed retrospectively, of whom 31 underwent ALPS implant treatment and 35 underwent PHILOS implant treatment. Intraoperative blood loss and operation time, postoperative Constant-Murley Shoulder Outcome (Constant-Murley) score, and complications variables were recorded for the comparison. All cases were regularly followed up for at least 1 year.

Results

The mean follow-up period was 400.8 days (range, 367–446 days). Union was achieved in 98.5% of patients (65/66). The ALPS group yielded similar radiologic and clinical outcomes to the PHILOS plating group for treating displaced proximal humeral fractures, including operation time, intraoperative blood loss, the Constant-Murley score, and varus malunion (P > 0.05, respectively). However, the incidence of total postoperative complications in the ALPS group was significantly lower than in the PHILOS group (P < 0.05). There was a trend of a lower complication rate of screws/pegs protrusion, avascular necrosis, subacromial impingement, postoperative infection, and reoperation in the ALPS group, although it was not statistically significant (P > 0.05, respectively).

Conclusion

The ALPS group yielded similar radiologic and clinical outcomes to the PHILOS plating group for displaced proximal humeral fractures, but the ALPS group had a significantly lower total rate of complications. Therefore, ALPS may be a better option for treating proximal humeral fractures. Further larger clinical studies are needed to confirm the findings presented here.

Trial registration

Retrospective study

The Cost-Effectiveness of Reverse Total Shoulder Arthroplasty Versus Open Reduction Internal Fixation for Proximal Humerus Fractures in the Elderly

BACKGROUND

Open reduction and internal fixation (ORIF) of proximal humerus fractures in elderly individuals (age >70) carries a relatively high short-term complication and reoperation rate but is generally durable once healed. Reverse total shoulder arthroplasty (RTSA) for fractures may be associated with superior short-term quality of life but carries the lifelong liabilities of joint replacement. The tradeoff between short and long-term risks, coupled with disparities in quality of life and cost, makes this clinical decision amenable to cost-effectiveness analysis.

METHODS

A Markov state-transition model was constructed with a base case of a 75 year-old patient. Reoperation rates, quality of life values, mortality rates, and costs were based upon published literature. The model was run until all patients had died to simulate the accumulated costs and benefits.

RESULTS

RTSA was associated with greater quality of life (7.11 QALYs) than ORIF (6.22 QALYs). RTSA was cost-effective with an incremental cost-effectiveness ratio of $3,945/QALY and $27,299/ QALY from payor and hospital perspectives, respectively. RTSA was favored and cost-effective at any age above 65 and any Charlson Score. The model was sensitive to the utility of both procedures.

CONCLUSION

RTSA resulted in a higher quality of life and was cost-effective in comparison to ORIF for elderly patients.Level of Evidence: III.

Late screw-related complications in locking plating of proximal humerus fractures: A systematic review

Locking plating is a common surgical treatment of proximal humeral fractures with satisfactory clinical results. Implant-related complications, especially screw-related, have been reported, however, the lack of information regarding their onset, used surgical technique, complexity of the fracture, bone quality etc., prevents from understanding the causes for them. The aim of this systematic review is to identify the potential risk factors for late screw complications by gathering information about the patient characteristics, comorbidities, fracture types, surgical approaches and implant types. A PubMed search was performed using humerus, fractures, bone and locking as keywords in clinical papers written in English. All abstracts and manuscripts on distal or humerus shaft fractures, and those on proximal humerus fractures without any or with only iatrogenic complications were excluded. One hundred studies met the inclusion criteria, resulting in 33% of the reported cases having at least one complication, with 11% of all complications being screw-related. Most of the latter were secondary screw perforations and screw cut-outs, being predominantly linked to poor bone quality, while screw loosening and retraction were found less frequently as a result of locking mechanism failure. Overall, the amount of information for complications was limited and screw perforation was the most frequent screw-related complication, mostly reported in female patients older than 50 years, following four-part or AO/OTA type C fractures and detected four weeks postoperatively. The sparse information in the literature could be an indicator that the late screw complications might have been under-reported and under-described, making the understanding of the screw-related complications even more challenging.

Reverse shoulder arthroplasty for proximal humerus fracture: a more complex episode of care than for cuff tear arthropathy

BACKGROUND

The purpose of this investigation is to identify the in-hospital and 30-day postoperative complications for reverse total shoulder arthroplasty (RTSA) performed because of proximal humerus fracture (PHFx) vs. cuff tear arthropathy (CTA), and determine whether acute fracture is associated with differences in complications after RTSA.

METHODS

The National Surgical Quality Improvement Program database was queried for RTSA performed for PHFx and CTA. This database contains surgical outcomes within 30 days after the index procedure. Patients underwent a 1:1 propensity matched based on preoperative demographics and comorbidities. Outcomes included operative time, length of stay (LOS), complications, transfusion, readmission, and discharge destination.

RESULTS

A total of 1006 patients (503 per group) were included. With a PHFx, operative time was longer (129.5 ± 54.2 vs. 96.0 ± 40.0 minutes, P < .001), and the patients were more likely to have an adverse event (19.0% vs. 8.2%, P < .001), require transfusion (15.71% vs. 3.98%, P < .001), have longer LOS (3.8 ± 3.6 vs. 2.2 ± 1.7 days, P < .001), and were more likely to be discharged to an extended care facility (27.2% vs. 10.3%, P < .001). PHFx was an independent risk factor for an adverse event after an RTSA.

CONCLUSIONS

RTSA to treat PHFx is associated with longer LOS, increased complications, and discharge to an extended care facility compared with RTSA for CTA. Patients with PHFx require more health care resources than patients with CTA. It is imperative for surgeons, patients, families, governments, hospital systems, and insurance payers to recognize the differences in resource utilization for RTSA in treating PHFx compared with CTA.

Parameterization of proximal humerus locking plate impingement with in vitro, in silico, and in vivo techniques

BACKGROUND

Locked plating of displaced proximal humeral fractures is common, but rates of subacromial impingement remain high. This study used a multidisciplinary approach to elucidate the relationships between common surgical parameters, anatomic variability, and the likelihood of plate impingement.

METHODS

The experiment was completed in 3 phases. First, a controlled in vitro experiment was conducted to simulate impingement. Second, a dynamic in silico musculoskeletal model modeled changes to implant geometry, surgical techniques, and acromial anatomy, where a collision detection algorithm was used to simulate impingement. Finally, in vivo shoulder kinematics were recorded for 9 activities of daily living. Motions that created a high likelihood of impingement were identified.

RESULTS

Of simulated impingement events, 73.9% occurred when the plate was moved proximally, and 84% occurred when acromial tilt was 20° or 25°. Simulations of impingement occurred at cross-body adduction angles between 10° and 50°. Impingement occurred at an average of 162.0° ± 14.8° abduction with 10 mm distal plate placement, whereas the average was 72.1° ± 11.4° with 10 mm proximal placement. A patient may encounter these shoulder angles when performing activities such as combing one's hair, lifting an object overhead, and reaching behind one's head.

DISCUSSION AND CONCLUSION

Proximal implant placement and decreases in acromial tilt play major roles in the likelihood of impingement, whereas plate thickness and humeral head center of rotation should also be considered. Careful preoperative planning that includes these factors could help guide operative decision making and improve clinical outcomes.

Biomechanical comparison of screw-based zones of a spatial subchondral support plate for proximal humerus fractures

Stabilisation of proximal humerus fractures remains a surgical challenge. Spatial subchondral support (S3) plate promises to overcome common complications associated with conventional proximal humerus plates. This study compared the biomechanical performance of S3 plate with a fixed-angle hybrid blade (Equinoxe Fx) plate and a conventional fixed-angle locking plate (PHILOS). The effects of removal of different S3 plate screws on the humeral stability were also investigated. A total of 20 synthetic left humeri were osteotomised transversely at the surgical neck to simulate a two-part fracture and were each treated with an S3 plate. Head screws were divided into three zones based on their distance from the fracture site. Specimens were divided into four equal groups where one group acted as a control with all screws and three groups had one of the screw zones missing. With humeral head fixed, humeral shaft was first displaced 5 mm in extension, flexion, valgus and varus direction (elastic testing) and then until 30 mm varus displacement (plastic testing). Load-displacement data were recorded to determine construct stiffness in elastic tests and assess specimens' varus stability under plastic testing. Removal of the screw nearest to the fracture site led to a 20.71% drop in mean elastic varus bending stiffness. Removal of the two inferomedial screw above it resulted in a larger drop. The proximal screw pair had the largest contribution to extension and flexion bending stiffness. Varus stiffness of S3 plate constructs was higher than PHILOS and Fx plate constructs. Stability of humeri treated with S3 plate depends on screws' number, orientation and location. Varus stiffness of S3 plate construct (10.54 N/mm) was higher than that of PHILOS (6.61 N/mm) and Fx (7.59 N/mm) plate constructs. We attribute this to S3 plates' thicker cross section, the 135° inclination of its screws with respect to the humeral shaft and the availability of pegs for subchondral support.

Outcomes following fixation for proximal humeral fractures

Fractures of the proximal humerus are a very common presentation in modern Trauma and Orthopaedic practice. In an ever-aging population, the incidence has dramatically increased resulting in a large socioeconomical burden. The surgical management of these injuries has evolved over the years. Patient outcomes are variable and there is no consensus on treatment approach. This review article focuses on the outcomes following fracture fixation using common surgical techniques.

Biomechanical analysis of plate systems for proximal humerus fractures: a systematic literature review

BACKGROUND

Proximal humerus fractures are the third most common in the human body but their management remains controversial. Open reduction and internal fixation with plates is one of the leading modes of operative treatment for these fractures. The development of technologies and techniques for these plates, during the recent decades, promise a bright future for their clinical use. A comprehensive review of in vitro biomechanical studies is needed for the comparison of plates' mechanical performance and the testing methodologies. This will not only guide clinicians with plate selection but also with the design of future in vitro biomechanical studies. This review was aimed to systematically categorise and review the in vitro biomechanical studies of these plates based on their protocols and discuss their results. The technologies and techniques investigated in these studies were categorised and compared to reach a census where possible.

METHODS AND RESULTS

Web of Science and Scopus database search yielded 62 studies. Out of these, 51 performed axial loading, torsion, bending and/or combined bending and axial loading while 11 simulated complex glenohumeral movements by using tendons. Loading conditions and set-up, failure criteria and performance parameters, as well as results for each study, were reviewed. Only two studies tested four-part fracture model while the rest investigated two- and three-part fractures. In ten studies, synthetic humeri were tested instead of cadaveric ones. In addition to load-displacement data, three-dimensional motion analysis systems, digital image correlation and acoustic emission testing have been used for measurement.

CONCLUSIONS

Overall, PHILOS was the most tested plate and locking plates demonstrated better mechanical performance than non-locking ones. Conflicting results have been published for their comparison with non-locking blade plates and polyaxial locking screws. Augmentation with cement [calcium phosphate or poly(methyl methacrylate)] or allografts (fibular and femoral head) was found to improve bone-plate constructs' mechanical performance. Controversy still lies over the use of rigid and semi-rigid implants and the insertion of inferomedial screws for calcar region support. This review will guide the design of in vitro and in silico biomechanical tests and also supplement the study of clinical literature.

Cadaveric study of the anatomical reference points for proximal humeral plate positioning

BACKGROUND

Complications following locking plate fixation in proximal humeral fractures often related to malposition plates and inadequate screw fixation. However, literature did not define the best anatomical reference point for plate positioning. We conducted a study to assess the occurrence of subacromial impingement and screw perforation with two anatomical reference points for proximal humeral plate positioning.

METHOD

Sixty shoulders of 30 cadavers were dissected, and proximal humeral locking plate was placed in two different levels in the coronal plane of the upper tip of plate: (1) the proximal portion of bicipital groove group and (2) the most prominent of lesser tuberosity group. Subacromial impingement during passive forward elevation and screw perforation were assessed in relation to the plate positioning.

RESULTS

No subacromial impingement during passive motion contacted to the plate in both groups. The calcar screw perforation rate was significantly lower in the proximal portion of the bicipital groove group (2 of 60 specimens, 3.33%) than the most prominent of lesser tuberosity group (52 of 60 specimens, 86.67%). The most proximal screws of the plate were no humeral head perforation in all specimens.

CONCLUSION

Our study would suggest that two anatomical reference points could be used to be the landmark to avoid the subacromial impingement and the most proximal screw perforation. However, the placement of the locking plate using the proximal portion of bicipital groove reference is better for calcar screw insertion.

Early Results of the A.L.P.S. Proximal Humerus Locking Plate

Background:

Open reduction internal fixation of displaced 3 and 4-part proximal humerus fractures is an effective treatment modality particularly for the younger age group, but it is not without complications. Fixed angled locking screw plates are the mainstay of fixation. The A.L.P.S. Proximal Humerus Plating System is a new implant that has smooth locking pegs in the place of humeral head screws to help reduce glenoid damage in the event of cut-out and is designed to sit low on the humerus in order to reduce the risk of subacromial impingement.

Methods:

Retrospective analysis of 15 consecutive patients who sustained closed displaced 3-part or 4-part fractures and had fixation surgery using the A.L.P.S. plate. Outcome measures were the time to radiographic and clinical union, Oxford Shoulder Score, quick DASH score and complications.

Results:

Average follow-up was 31.9 weeks. Union was achieved in 100% of patients with a mean time to union of 15.1 weeks. In terms of function, mean OSS was 33.6 and mean quick DASH was 32.5. There were no instances of AVN.

Conclusion:

Our preliminary results of 15 patients followed up for a mean of 31.9 weeks show equitable union rates and time to union as well as functional scores compared to other available plating systems. This is the first study to report on this implant to date.

Plate fixation of the proximal humerus: an international multicentre comparative study of postoperative complications

OBJECTIVE

The primary aim was to evaluate the number of complications following locking plate fixation of proximal humeral fractures in country X and in country Y. The secondary aim was to identify risk factors for complications.

METHODS

Multicentre retrospective case series of 282 consecutive patients with proximal humeral fractures, treated with a locking plate between 2010 and 2014.

SETTING

two level 1 trauma centres in country X and one in country Y. Data pertaining to demographics, postoperative complications and re-operations were collected. Fractures were classified according to the AO and Hertel classifications and experienced surgeons assessed the quality of reduction and plate fixation on the postoperative X-rays. Outcomes of the two different countries were compared and logistic regression analysis was performed to analyse the relationship between risk factors and complications.

RESULTS

During a median follow-up of 370 days, 196 complications were encountered in 127 patients (45%). The most frequent complications were: screw perforation in the glenohumeral joint (23%), persistent shoulder complaints (16%), avascular necrosis of the humeral head (10%) and secondary fracture displacement (5%). In 80 patients (28%), 132 re-operations were performed. The patients operated in country X had significantly more complications compared with the patients operated in country Y. For implant-related complications, advanced age, non-anatomic reduction of the greater tuberosity, and country of operation were risk factors.

CONCLUSION

The use of locking plates for proximal humeral fractures was associated with a high number of complications in both countries; the patients operated in country Y, however, had better results compared with the patients operated in country X.

LEVEL OF EVIDENCE

IV.

Detection of primary screw perforation in locking plate osteosynthesis of proximal humerus fracture by intra-operative 3D fluoroscopy

PURPOSE

The purpose of this study was to identify the rate of primary screw perforations after osteosynthesis of proximal humerus fractures with intra-operative 3D fluoroscopy and to analyse the rate of secondary screw perforations as well as complications, outcome, and revision surgeries after a minimum of 12 months.

MATERIALS AND METHODS

Thirty-three patients (20 female, 13 male, median age 67 years, range 35-85 years) with displaced proximal humerus fractures were included. After reduction and fixation, an intra-operative 3D fluoroscopy was performed to evaluate primary screw perforations (PS) and screws with "near perforation" (nPS). These screws were changed intra-operatively. Patients were followed-up for a minimum of 12 months. Clinical and radiological parameters, such as secondary screw perforation, secondary loss of reduction, or functional outcome, were investigated.

RESULTS

In six patients (18.2%), humeral head screws were changed due to primary PS (n = 2) or nPS (n = 4) after the intra-operative 3D fluoroscopy. Follow-up revealed an adapted constant score (%CMS) of 76.2% after a mean follow-up of 17.7 months. Two secondary screw perforations were observed (6%). Loss of reduction was observed in eight patients (24.2%).

CONCLUSION

The intra-operative 3D reveals a high rate of primary screw perforations or near perforations. Immediate change of these screws may lead to a lower rate of secondary screw perforations and, therefore, reduce post-operative complications.

Operative repair of proximal humerus fractures in septuagenarians and octogenarians: Does chronologic age matter?

BACKGROUND

With an expected doubling of the geriatric population within the next thirty years it is becoming increasingly important to determine who among the elderly population benefit from orthopaedic interventions. This study assesses post-operative outcomes in patients aged seventy or greater who sustained a proximal humerus fracture and were treated surgically as compared to a younger geriatric cohort to determine if there is a chronologic age after which post-operative outcomes significantly decline.

METHODS

A retrospective chart review was conducted for 201 patients who sustained fractures of the proximal humerus (OTA 11A-C) and were treated operatively by open reduction and internal fixation. Data from 132 independent, active patients aged fifty-five or older was identified and analyzed. Forty-seven patients age 70 or older were compared to 78 patients aged 55-69. Average length of follow-up was 19.5 months. All complications were recorded. Univariate and multivariate analysis was conducted to assess for differences between groups.

RESULTS

95% of patients achieved fracture union within 6 months. No significant differences were found between cohorts with regard to gender, fracture severity, or CCI (p = 0.197, p = 0.276, p = 0.084, respectively). Functional outcome scores, shoulder range of motion, and complications rates for patients aged 70 and older were not significantly different from patients aged 55-69. There were 10 complications in the older elderly cohort (21%), 6 of which required re-operation and 13 complications in the young elderly cohort (17%), 8 of which required re-operation.

CONCLUSIONS

Operative fracture repair using locked plating of the proximal humerus in septuagenarians and octogenarians can provide for excellent long-term outcomes in appropriately selected patients. These patients tend to have long term functional outcome scores, post-operative range of motion, and complication rates that are comparable to younger geriatric patients. Physicians should not exclude patients for repair of proximal humerus fractures based on chronological age cutoffs.

Hertel 7 fracture of the humeral head. Can two different fixation systems (Diphos/PHP) lead to different outcomes? A retrospective study

OBJECTIVE

To compare clinical outcomes and complication rates in the medium-to-long-term follow-up of Hertel 7 humeral head fractures treated with two different locking plates.

MATERIALS AND METHODS

A total of 52 patients with type 7 humeral head fracture (in accordance with Hertel classification) were enrolled retrospectively: 24 patients [4 male, 20 female; mean age (standard deviation [SD]): 68.9 (5.8) years] were treated with Diphos H plate (Group A) and 28 patients [6 male, 22 female; mean age (SD): 61.0 (7.5) years] with Proximal Humeral Plate (PHP; Group B). The mean follow-up periods were 25.6 and 18.9 months, respectively. Functional outcomes were assessed using the Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score; X-ray evaluation was also performed and complications were recorded.

RESULTS

The mean Constant score in the Diphos and PHP groups at follow-up were 75.6 (SD 13.4) and 78.9 (SD 12.8), respectively (p>0.05). The DASH score was similar in both groups (Diphos: 18.6, range 0-51.5; PHP: 16.8, range 0-47.8) (p>0.05). In our series, 9.6% of patients had complications; these included a case of aseptic non-union and a case of avascular necrosis of the humeral head in each group, and a secondary screw perforation in a patient treated with Diphos.

CONCLUSIONS

In patients with Hertel 7 proximal humeral fractures, Diphos and PHP lead to similar satisfactory functional outcomes and are associated with low complication rates; this confirms that both are useful implants for the treatment of this pattern of fracture.

Significant Differences Between Local Reporting and Central Assessment of Radiographic Complications in a Prospective, Multicenter Study About Locking Plate Fixation of Proximal Humerus Fractures

OBJECTIVES

To compare reporting outcomes of radiographic complications conducted by an independent review board and the responsible on-site study personnel in a multicenter study about locking plate fixation of proximal humeral fractures.

DESIGN

Prospective, multicenter study; setting: 9 level I trauma centers.

PATIENTS

One hundred fifty patients (age 50-90) with a radiographically confirmed displaced proximal humeral fracture fixed with a locking plate were included in the study.

INTERVENTION

All radiographic data were reevaluated by an independent review board according to predefined criteria.

MAIN OUTCOME MEASUREMENTS

Differences in outcomes between the review board and the on-site assessment were analyzed with a paired t test. Interrater agreements between the central review board and on-site assessments were estimated by means of kappa statistics.

RESULTS

The review board revealed significantly more radiographic complications than the on-site assessment (P = 0.006), except for the complication "head necrosis." The interrater agreement was slight to moderate in all calculated categories.

CONCLUSIONS

Implementation of a complication review board using predefined criteria is recommended for clinical studies to prevent underreporting of radiographic complications by on-site assessment.

Displaced proximal humeral fractures: when is surgery necessary?

BACKGROUND

Several therapeutic methods have been traditionally used in the treatment of displaced proximal humeral fractures; however, the indication of these treatments is still controversial. The purpose of this study was to compare the medium-term functional results of four methods commonly used in the treatment of proximal humeral fractures [conservative treatment, proximal humeral nails (PHN), percutaneous K-wiring (PKW), and locking-plates (LP)] taking into consideration the type of fracture and the age of the patients.

METHODS

We conducted a retrospective cohort study on patients with proximal humeral fractures treated with one of the following methods: conservative treatment, PHN, PKW, or LP. Functional results were assessed using the absolute Constant score and the disabilities of the arm shoulder and hand score (DASH). The functional outcome was analysed according to age (≥65 years and <65 years) and fracture type (displaced 2-fragment and 3-4-fragment fractures).

RESULTS

A total of 113 patients were included in the study, with a mean age of 65.3 SD 15.2 years and average follow-up time of 26.2 SD 12.6 months. Patients under 65 years had higher Constant scores when treated with PHN and PKW than those treated conservatively (77.2 vs. 54.7, p=0.01 and 74.0 vs. 54.7, p=0.03, respectively). Patients above 65 years had higher Constant scores when treated with PKW compared to PHN and conservative treatment (68.7 vs. 51.9, p=0.02 and 68.7 vs. 55.9, p=0.029, respectively). In 2-fragment fractures, PKW resulted in higher Constant scores than conservative treatment (70.4 vs. 53.9, p=0.048). No differences were found in the final outcome between patients treated with LP and those treated conservatively regardless of age, and fracture type. There were also no differences between any of the evaluated methods in the treatment of 3-4-fragment fractures.

CONCLUSION

The use of PKW was associated with better functional results than conservative treatment in individuals of all ages, especially in patients with 2-fragment fractures; PKW also achieved better functional results than PHN in elderly patients. PHN was superior to conservative treatment in young individuals. No significant differences were found between LP and conservative treatment in any of the analysed categories.

Long contoured locking plate fixation of traumatic proximal humeral fractures with distal extension

BACKGROUND

There is a paucity of data available with respect to outcome on long contoured locking plate fixation for proximal humerus fractures with distal fracture extension.

METHODS

Thirty-four patients with traumatic proximal humerus fractures with distal extension underwent fixation with long contoured locking plates. Twenty-five patients (74%) were included in the study: one patient died, two patients had unrelated illnesses resulting in them being unable to complete follow-up assessment and six were lost to follow-up. Patients' case notes and radiographs were retrospectively reviewed, and patients were contacted to assess functional outcome using the Visual Analogue Scale (VAS) for pain, Disabilities of the Arm, Shoulder and Hand (DASH) score, Oxford Shoulder Score (OSS) and Stanmore Percentage of Normal Shoulder Assessment (SPONSA).

RESULTS

Mean follow-up was 27 months (range 11 months to 60 months). Mean pain at final follow-up was 3.6 [95% confidence interval (CI) = 2.5 to 4.8] with only four patients having residual pain greater than 5 on the VAS scale. Mean DASH score was 41.2 (95% CI = 32.0 to 50.4), mean OSS was 29.1 (95% CI = 24.3 to 33.9) and mean SPONSA was 63.9% (95% CI = 50.8 to 77.2). There was one wound infection. Three patients had non-unions that required bone grafting and revision internal fixation.

CONCLUSIONS

We feel long contoured locking plates represent a useful treatment option for complex proximal humerus fractures.

Fractures and fracture-dislocations of the proximal humerus: A retrospective analysis of 82 cases treated with the Philos(®) locking plate

OBJECTIVE

To present the experience in a single institution of the management of 82 consecutive fractures and fracture-dislocations of the proximal humerus treated with the Proximal Humeral Internal Locking System (Philos(®)) plate.

MATERIALS AND METHODS

A total of 81 patients with 82 proximal humerus fractures (one patient had bilateral fracture) were treated at our institution with open reduction and internal fixation with Philos(®) plate from January 2008 to December 2012 and the clinico-radiological outcome was analysed. Twelve of these patients also had a dislocation of the proximal humerus. According to the Neer classification, there were seven two-part fractures, 40 three-part fractures and 35 four-part fractures. All patients received a similar physical therapy programme following internal fixation. Mean final follow-up was 32 months. Functional outcome was evaluated for each patient using the Constant-Murley score; radiographic evaluation was also conducted and complications were recorded.

RESULTS

At the end of the follow-up period, the mean Constant-Murley score for the injured side was 75 points (range 42-92); results were graded as excellent for eight patients, good for 52, moderate for 17 and poor for five. Twenty-three patients (28%) had complications during the follow-up period. Reoperation was required in 12 patients. Complications included avascular necrosis of the humeral head in 10 patients (12%), varus positioning of the head in four patients (4.8%), impingement syndrome in three patients (3.6%), secondary screw perforation in three patients (3.6%), non-union of the fracture in two patients (2.4%) and infection in one patient (1.2%).

CONCLUSIONS

Open reduction and internal fixation of proximal humeral fractures with the Philos(®) plate was associated with good clinical outcomes provided the correct surgical technique was used. To better evaluate the real incidence of complications, it is important to follow patients for more than one year after surgery as some complications may arise after this time.

Early outcomes of proximal humerus fracture fixation with locking plate and intramedullary fibular strut graft

Proximal humerus fractures are commonly encountered in elderly patients. Surgical treatment demonstrates high complication rates, including varus construct collapse and screw cutout. In this study, the authors evaluate the clinical outcome of locking plate fixation with intramedullary fibular strut graft augmentation as a primary surgical treatment in the prevention of early collapse and screw cutout. A total of 9 patients were evaluated. Surgery was performed for displaced proximal humerus fractures between April and December 2011. Patients were either class 2, 3, or 4, according to Neer classification. Mean patient age was 75.4 years. Preoperative and immediate, 6-week, and 3-month postoperative radiographs were evaluated. Head-shaft angles were measured to assess for varus collapse and displacement. Range of motion, complication rates, and functional recovery were also evaluated. Patients underwent open reduction and internal fixation with placement of an intramedullary fibular strut graft. Fixation was achieved with a Philos plate (Synthes, Oberdorf, Switzerland). Reduction and fixation were evaluated with radiographs. Passive exercises and range of motion were allowed immediately postoperatively, and all patients achieved active abduction and forward flexion 6 weeks postoperatively. Shoulder radiographs taken 12 weeks postoperatively revealed no loss of reduction or screw cutout. The introduction of the locking plate has improved outcomes. The addition of an intramedullary strut graft has shown improved preliminary results. Maintained reduction was observed in all 9 patients in the early postoperative period, and good functional motion was achieved. No incidence of screw cutout was recorded.

Three-dimensional analyses of proximal humeral fractures using computed tomography with multiplanar reconstruction: early stability of fixation after osteosynthesis in relation to preoperative bone quality

The purpose of this study was to evaluate the relationship between the bone quality of the humeral head measured by CT multiplanar reconstruction images (MPR) and the stability of nail or plate fixation and to compare the clinical outcomes of these procedures in patients with proximal humeral fractures. Thirty-six consecutive patients (nail group: n = 18, plate group: n = 18) were investigated. In nail group, 14 cases were classified as two-part fractures, three cases were classified as three-part fractures and one case was classified as four-part fractures. In plate group, three cases were classified as two-part fractures, nine cases were classified as three-part fractures and six cases were classified as four-part fractures. Both clinical and radiological outcomes were assessed. In addition, the percentage of trabecular bone volume of the humeral head was calculated using preoperative CT-MPR images. Three patients in the nail group underwent reoperation. In contrast, no patients in the plate group underwent reoperation. In nail group, six of 18 (33%) patients demonstrated poor results (three underwent reoperation, and three had varus displacements >10º) and had bone volume percentages (axial image) that were significantly lower than those observed in the patients with good results. The cutoff point of trabecular bone volume required to obtain satisfactory results after surgical treatment using intramedullary nail was 78%. The results of this study suggest that the bone volume of the humeral head calculated using CT-MPR images provides useful information, in addition to the type of fracture, when selecting fixation devices for osteosynthesis of proximal humeral fracture.

Functional outcomes following locking plate fixation of complex proximal humeral fractures

The purpose of this study was to evaluate the functional outcome of patients with complex proximal humeral fractures fixated by locking plate technology. Eighty-nine patients (27 men, 62 women) older than 50 years with 3- and 4-part proximal humeral fractures were treated using locking plate fixation and followed up for more than 1 year. Functional outcomes were assessed by using the Disabilities of the Arm, Shoulder, and Hand (DASH) and Constant scores, and the complications were evaluated through physical and radiographic examinations. Mean DASH and Constant scores for all 89 patients were 19.6 and 66.6 points, respectively. No significant differences existed in the 2 scores between patients with 3- and 4-part fractures. Of the 71 patients without complications, 68 had an excellent functional outcome according to the DASH score, whereas 2 patients had an excellent outcome on the Constant score. For the 18 patients with complications, the functional outcomes were significantly poorer compared with patients without complications. According to the Constant score, all patients with complications were classified into a moderate or poor functional outcome, but the rate was 12% with the DASH score. In patients with 3- and 4-part proximal humeral fractures fixed with locking plate fixation, complications were the major cause of compromised functional outcomes. Based on these results, different conclusions would be reached when the functional outcome was assessed by using the DASH and Constant scores separately. Because the clinician-based Constant score may bias the results, patient-based assessments, such as the DASH score, are required for the evaluation of functional outcome after shoulder surgery.

Treatment for displaced proximal humerus fractures: comparison of interlocking plate fixation versus minimal invasive techniques

BACKGROUND AND PURPOSE

The functional results and the complications following interlocking plate fixation of displaced proximal humerus fractures should be evaluated and compared with those following minimal invasive fixation techniques.

PATIENTS AND METHODS

Fifty patients (30 women, 20 men, mean age 62.7 (18-91) years) were treated for a displaced proximal humerus fracture using an interlocking plate fixation (PHILOS®) between 2003 and 2004. The mean follow-up time was 12 (9-36) months. Functional and radiographic results (Constant-Murley and Neer scores) were analyzed and compared with an equivalent historical control group of 53 patients operated for the same fracture types using minimal invasive techniques (K-wires and/or cannulated screws) between 1995 and 1997. According to the OTA/AO classification, there were 15 type A, 18 type B, and 17 type C fractures in the plate fixation group, and 23, 25, and 5 of these types in the control group, respectively.

RESULTS

The mean Neer score was 85.9, the mean Constant-Murley score 84, whereas 82.4 and 75.4 for the control group, respectively. Good and excellent results were seen in 78%, whereas in 70% in the control group. The results were dependent upon the fracture's type, sex, and patient's age. Complications were seen in 9 patients, whereas in 16 patients in the control group.

INTERPRETATION

Using an interlocking plate, the indication of fixation of displaced proximal humerus fractures had been expanded to type C fractures. The implant failure rate can be reduced. The functional results achieved are better compared with those following minimal invasive techniques.

Open reduction internal fixation of proximal humerus fractures

The treatment of proximal humerus fractures continues to evolve. While the many of these injuries can be managed nonoperatively, a certain percentage require operative treatment. Open reduction internal fixation can offer excellent outcomes when performed in the appropriate patient and utilizing proper techniques. This article reviews the most up-to-date literature regarding all phases of proximal humerus fracture osteosynthesis, including diagnosis, imaging, anatomic considerations, surgical indications, fixation, and surgical outcomes.

Proximal humeral fracture fixation: a biomechanical comparison of two constructs

BACKGROUND

Different options exist for stabilizing proximal humeral fractures. This study compared the mechanical stability of 2 common proximal humeral fixation plates in bending and torsion.

METHODS

Tests were conducted on 40 synthetic and 10 matched pairs of cadaveric humeri (evenly fixed with DePuy S3 proximal humeral plating system [DePuy Orthopaedics, Warsaw, IN, USA] and Synthes proximal humerus locking compression plate [Synthes, Paoli, PA, USA]). Half of the humeri were tested by cantilevered bending in flexion, extension, varus, and valgus for 100 cycles of ±5 mm of displacement at 1 mm/s before loading to failure in varus. The other half were tested in torsion for 100 cycles of ±8° of rotational displacement at 1°/s before loading to failure in external rotation.

RESULTS

Peak cyclic loads for synthetic constructs were higher for DePuy plates than Synthes plates in varus and valgus (P < .0001), but a difference was not detected in extension (P > .40) or flexion (P = .0675). Peak cyclic loads for cadaveric constructs showed a significant difference in extension and flexion (Synthes > DePuy, P < .0001) and in varus (DePuy > Synthes, P < .05) but not in valgus (P > .10). Bending stiffness during varus failure testing was higher for DePuy plates than Synthes plates (P < .0001) for synthetic constructs. Regarding torsion of synthetic and cadaveric constructs, DePuy plates experienced higher peak cyclic torques over all cycles in both directions (P < .0001). For synthetic constructs, DePuy plates showed higher torsional stiffness in external failure than Synthes plates (P < .0001).

CONCLUSIONS

The DePuy plate was stiffer than the Synthes plate with varus and valgus bending, as well as in torsion. The Synthes plate tended to be stiffer in flexion and extension.

Comparison of two different locking plates for two-, three- and four-part proximal humeral fractures--results of an international multicentre study

PURPOSE

The aim of this study was to compare the functional outcome, quality of restoration, and complication rate after open reduction and internal fixation (ORIF) of displaced or unstable 2-, 3- and 4-part humeral fractures using two different locking plates.

METHODS

The data used in this analysis was prospectively collected in two large multicentre studies in 15 European Level 1 trauma centres. A total of 318 patients with proximal humeral fractures were treated with ORIF using either the locking proximal humerus plate (LPHP) or proximal humeral internal locking system (PHILOS). Outcome measurements included Constant and Neer scores, evaluation of local pain at the fracture site and complications, and radiographic assessment at one year.

RESULTS

At one year, the mean Constant scores (relative to the contralateral shoulder) improved significantly for both groups and were above 80% for 2-, 3-, and 4-part fractures. A significantly shorter surgical time, less pain at the fracture site, and better functional outcome was achieved by PHILOS-treated patients with 2-part fractures throughout the one-year follow-up month and with 3-part fractures at three months (p < 0.05). There was no difference between the treatment outcomes for 4-part fractures, and no difference in the complication rates (p > 0.05).

CONCLUSIONS

PHILOS and LPHP can be considered as useful implants for ORIF of displaced and unstable proximal humeral fractures. There was a slight advantage of the PHILOS system with regard to operative time and functional outcome, especially for the treatment of 2- and 3-part fractures.