Two-part Proximal Humerus Fractures Research Articles

Optimization of Locking Plate Screw Angle Used to Treat Two-Part Proximal Humerus Fractures to Maintain Fracture Stability

Proximal humerus fractures increase with the aging of the population. Due to the high failure rates of surgical treatments such as open reduction and internal fixation (ORIF), biomechanical studies seek to optimize the treatments and intervening factors to improve the quality of life of people undergoing these treatments. The aim of the present study was to determine the optimal insertion angle configuration of screws used in a two-part proximal humerus fracture-locking plate osteosynthesis treatment based on finite element analysis (FEA). A series of 3D models of PHILOS locking plates with different screw insertion angle configurations were designed using a matrix system for screw angulation. The locking plate models were evaluated in a two-part proximal humerus fracture with surgical neck fracture under bending and compressive loading conditions using FEA and statistically analyzed using a design of experiments (DOE). The optimal screw insertion angle setting showed an improvement in relation to the interfragmentary strain value of the fracture. Moreover, calcar screws were the most significant feature in fracture stability throughout the tests, followed by the divergence of the most proximal screws and the proximal–distal alignment of the locking plate.

Outcomes of Percutaneous Pinning Technique in the Management of Two-Part and Three-Part Proximal Humerus Fracture in Adults

Background: Proximal humerus fractures represent 4-5% of over-all fractures. In patients above 40 years of age, it accounts for 75% of all humerus fractures. Fractures of the proximal end of the humerus oftentimes represent a management dilemma with the multiple surgical options available to deal with them. Objective: To evaluate the functional and radiographic outcomes of the percutaneous pinning techniques in the management of two-part and three-part proximal humerus fracture. Patients and Methods: A case series of 25 patients, functional outcome was determined by ASES and Constant scores and multiple radiographic views were taken to assess the fracture union, mal-union, and the presence of avascular necrosis. Results: ASES score of the whole group was 87.27 while the mean Constant score was 79.04. Only 16% of the entire group developed varus malunion (defined by Neck-Shaft-Angle <=120degrees). Moreover, 16% of the whole group developed OA of the glenohumeral joint. Conclusion: This study supports that the percutaneous close reduction and pinning technique is an effective and reliable surgical technique in the management of closed two-part and three-part proximal humerus fractures in adults. Appropriate preoperative planning is important to achieve a successful surgical result, and regular postoperative follow-up and rehabilitation are essential to get an optimum functional outcome. Keywords: Proximal humerus fracture, percutaneous pinning, upper extremity surgery, trauma surgery, Clinical outcomes, Percutaneous fracture fixation

Biomechanical behavior of three types of fixation in the two-part proximal humerus fracture without medial cortical support.

BackgroundThe purpose of this study was to evaluate the role of a non-locking plate applied to the anteromedial surface of the proximal humerus on loads at the implant-bone interface of non-locking and locking lateral plate fixation of proximal humeral fractures with a medial gap.MethodsTwenty synthetic humeri models were used. In fifteen, the proximal portion of the humerus was osteotomized to create a two-part surgical neck fracture, with a 10-mm medial gap and a 5-mm lateral gap; five models were controls. In the osteotomized humeri, five models were stabilized with a locking lateral plate (group L), five with a locking lateral plate and an anteromedial non-locking plate (group L+T), and five with a non-locking lateral plate and a non-locking anteromedial plate (group T+T). All humeri were tested under axial loading until catastrophic failure, which was characterized as complete closure of the medial gap. Stiffness was calculated using force vs. displacement curves. The data were analyzed via descriptive and inferential studies, at a 5% significance level.ResultsStatistically significant differences were seen among all the constructions. The combination of a lateral locking plate with an anteromedial non-locking plate (group L+T) was the stiffest construction, while the combination of a non-locking lateral plate with a non-locking anteromedial plate (group T+T) was the least stiff, even in comparison with a single locking lateral plate (p = 0.01). When the two groups which utilized a lateral locking plate (groups L+T and L) were compared, the group with additional anteromedial support demonstrated greater stiffness (p = 0.03), and stiffness values for the control group comprised of intact humeri models were even higher (p = 0.01).ConclusionCombining a lateral locking plate with a non-locking anteromedial plate provides a stiffer construction for fixation of unstable two-part proximal humerus fractures with a medial gap. Mechanical benefits of medial support with a second non-locking antero-medial plate seems to be related with better construct stability in terms of strength and fatigue, potentially reducing the risk of varus collapse of the humerus head and fracture healing disturbances.

Effect of screw thread length on stiffness of proximal humerus locking plate constructs: A finite element study

Plate-based treatment of proximal humerus fractures is associated with a high risk of complications such as screw perforation into glenohumeral joint. Smooth and threaded pegs were developed with the hope of minimising these risks. No consensus exists onto which threading profile achieves stiffest bone-plate construct. This study investigated the biomechanical effect of five percentages of threading on individual humeral head screws on a bone-plate construct. A finite element model simulating a two-part proximal humerus fracture treated with a Spatial Subchondral Support plate was developed and validated against in vitro biomechanical tests. The proportion of the humeral head screw length that was threaded was varied between 0%-100% in 25% increments. A 5-mm cantilever varus displacement was applied and the required load (F5) was calculated. Full (100%) threading achieved the stiffest construct for all six screws. Fully threading all smooth pegs at once increased F5 by 18%. Threading did not increase F5 equally in all screws. Inferior three plate screws exhibited a larger increase in stiffness than superior three. Most of the mechanical benefits of threading in inferior three screws can be achieved by using threaded pegs (50% threading) while the superior three screws need to be fully threaded. In practice, the smooth surface profile may also offer additional mechanical benefits if implanted with longer lengths and larger diameters. Threading is an effective way of increasing the varus bending stiffness of proximal humerus plates constructs.

Parametric Design Optimisation of Proximal Humerus Plates Based on Finite Element Method

Optimal treatment of proximal humerus fractures remains controversial. Locking plates offer theoretical advantages but are associated with complications in the clinic. This study aimed to perform parametric design optimisation of proximal humerus plates to enhance their mechanical performance. A finite element (FE) model was developed that simulated a two-part proximal humerus fracture that had been treated with a Spatial Subchondral Support (S3) plate and subjected to varus bending. The FE model was validated against in vitro biomechanical test results. The predicted load required to apply 5 mm cantilever varus bending was only 0.728% lower. The FE model was then used to conduct a parametric optimisation study to determine the orientations of inferomedial plate screws that would yield minimum fracture gap change (i.e. optimal stability). The feasible design space was automatically identified by imposing clinically relevant constraints, and the creation process of each FE model for the design optimisation was automated. Consequently, 538 FE models were generated, from which the obtained optimal model had 4.686% lower fracture gap change (0.156 mm) than that of the manufacturer’s standard plate. Whereas its screws were oriented towards the inferomedial region and within the range of neck-shaft angle of a healthy subject. The methodology presented in this study promises future applications in patient-specific design optimisation of implants for other regions of the human body.

Clinical outcome of intramedullary nailing versus locking plate fixation of two-part proximal humerus fractures: a meta-analysis

Objective To compare the clinical outcome of intramedullary nail with locking plate in the treatment of two-part proximal humerus fractures. Methods PubMed, SpringerLink, EMBASE, The Cochrane Library, Medline, Science Direct, CNKI, Wanfang Data and VIP database were searched for relevant studies comparing intramedullary nailing and locking plate fixation of two-part proximal humerus fractures. A meta-analysis of the two methods was conducted using the RevMan 5.0. Differences between the two methods were compared with respect to operation time, intraoperative bleeding, bone union time, Constant score and postoperative complication incidence. Results Seven studies were included in the meta-analysis, with 136 patients treated with intramedullary nail and 159 patients treated with locking plate. Intramedullary nailing showed advantages over locking plate fixation with regards to operation time (WMD=-27.71, 95%CI-36.07--19.35, P 0.05) and postoperative complication incidence (OR=0.89, 95%CI 0.43-1.84, P>0.05). Conclusion Intramedullary nail is superior to locking plate in operation time, intraoperative blood loss and bone union time for the treatment of two-part proximal humerus fractures, but the two methods are similar in Constant score and postoperative complications rate. Key words: Fracture fixation, intramedullary; Bone plates; Humeral fractures; Meta-analysis

A comprehensive update on current fixation options for two-part proximal humerus fractures: A biomechanical investigation

BackgroundRecent advancements in implant technology offer updated options for surgical management that have been rapidly adopted into clinical practice. The objective of this study is to biomechanically test and compare the current fixation options available for surgical fixation of two-part proximal humerus fractures and establish load to failure and stiffness values. MethodsSixteen match-paired (32 total) fresh-frozen, cadaveric specimens were randomized to receive 1 of 4 fixation constructs following creation of an AO/OTA Type 11A3 (two-part) proximal humerus fractures. Fixation constructs tested consisted of 3.5mm fixed angle plate (3.5-FAP), 4.5mm fixed angle plate (4.5-FAP), humeral intramedullary nail (IMN), and a humeral intramedullary nail with a fixed angle blade (IMN-FAB). Specimen bone density was measured to ensure no adequate, non-osteoporotic bone. Constructs were tested for stiffness and ultimate load to failure and compared via one-way ANOVA analysis with subsequent post hoc Tukey HSD multiple group comparison statistical analysis. ResultsThe IMN-FAB construct was significantly stiffer than the 3.5-FAP construct (123.8 vs. 23.9, p<0.0001), the 4.5-FAP construct (123.8 vs. 33.3, p<0.0001) and the IMN construct (123.8 vs. 60.1, p=0.005). The IMN-FAB construct reported a significantly higher load to failure than the 3.5-FAB construct (4667.3N vs. 1756.9N, p<0.0001), and the 4.5-FAP construct (4667.3N vs. 2829.4N, p=0.019, Table 2). The IMN construct had a significantly higher load to failure than the 3.5-FAP construct (3946.8 vs. 1756.9, p=0.001, Table 2). ConclusionBiomechanical testing of modern fixation options for two-part proximal humerus fracture exhibited that the stiffest and highest load to failure construct was the IMN-FAB followed by the IMN, 3.5-FAP and then the 4.5-FAP constructs. However, prospective clinical trials with longer-term follow-up are required for definitive assessment of the ideal fixation construct for surgical management of two-part proximal humerus fractures.

Treatment of Two-Part Proximal Humerus Fractures: Intramedullary Nail Compared to Locked Plating

Two-part proximal humerus fractures are common orthopedic injuries for which surgical intervention is often indicated. Choosing a fixation device remains a topic of debate. The purpose of this study is to compare two methods of fixation for two-part proximal humerus fractures, locking plate (LP) with screws versus intramedullary nailing (IMN), with respect to alignment, healing, patient outcomes, and complications. To our knowledge, a direct comparison of these two devices in treating two-part proximal humerus fractures has never before been studied. We hope that our results will help surgeons assess the utility of LP versus IMN. A retrospective chart review was performed on 24 cases of displaced two-part surgical neck fractures of the humerus. Twelve shoulders were treated using IMN fixation and 12 others were fixated with LP. Data collected included sociodemographic, operative details, and postoperative care and function. Radiographic comparison of fixation demonstrated an average neck-shaft angle of 124° and 120° in the IMN group and LP group, respectively. Adjusted postoperative 6-month follow-up range of motion was 134° of forward elevation in the IMN group and 141 in the LP group. The differences in range of motion and in complication rates were not found to be significant. Our results suggest that either LP fixation or IMN fixation for a two-part proximal humerus fracture provides acceptable fixation and results in a similar range of shoulder motion. Although complication rates were low and insignificant between the two groups, a trend toward increased complications in the IMN group is noted.

Relationship of Cortical Thickness of the Proximal Humerus and Pullout Strength of a Locked Plate and Screw Construct

No study to date has evaluated cortical thickness as it relates to locking plate failure or screw pullout in the proximal humerus. The purpose of this study is to determine the relationship between proximal humerus cortical thickness and locked plate hardware failure in a cadaveric proximal humerus fracture model. Twelve humerus specimens were placed into two groups based on the proximal humerus cortical thickness on an anteroposterior radiograph: less than 4 mm and greater than 4 mm. The specimens were plated with a six-hole proximal humerus locking plate and a 15-mm resection osteotomy at the surgical neck was performed. The specimens were tested in a materials testing machine at a displacement of 5 mm/min to failure. Load at failure, stiffness, maximum load, failure, and fracture gap closure were all statistically similar (P > 0.05) between the groups. Our biomechanical study used modern locked plate-screw construct fixation of a simulated two-part proximal humerus fracture. The mechanical strength was unaffected based on a threshold combined proximal humerus cortical thickness of 4 mm.

Nonoperative management of a patient with a two-part minimally displaced proximal humerus fracture: A case report

ABSTRACTProximal humerus fractures account for up to 10% of all fractures; however, the literature lacks any detailed nonoperative management protocols or treatment progression guidelines that are based on large randomized controlled trials. Several studies support conservative treatment of minimally displaced fractures, yet they do not document the specific interventions used nor do they provide rationale for progression. This case report describes the conservative rehabilitation of a patient following a traumatic, minimally displaced, two-part proximal humerus fracture. The patient was a 58-year-old female who was referred to physical therapy 4 weeks following arm sling immobilization with the primary goal of returning to full-time employment as a retail associate. Outcome measures included the McGill Pain Questionnaire, a numeric pain rating scale, and goniometric range of motion. Upon discharge the patient had zero complaints of pain, improved range of motion, and increased strength, and she returned to her prior level of function. The interventions used along with rationale are described in detail. The plan of care for this patient may be used as a framework for further research to determine the true effectiveness of nonoperative treatment.

Osteossíntese das fraturas da extremidade proximal do úmero com sistema de placa de ângulo fixo com parafusos bloqueados: técnica e resultados

OBJETIVO: Descrever os resultados do tratamento cirurgico das fraturas da extremidade proximal do umero com a placa de sistema bloqueado Philos. METODOS: Entre marco de 2003 e outubro de 2004 foram avaliados, de forma prospectiva, 24 de 26 pacientes com fratura da extremidade proximal do umero tratados com a placa Philos. A media de seguimento foi de 12 meses e da idade dos pacientes, de 57 anos. Seis pacientes tinham fraturas em quatro partes, 11 em tres partes e nove em duas partes. A avaliacao clinica foi feita por meio dos criterios da University of California at Los Angeles (UCLA). RESULTADOS: A media do escore da UCLA foi de 30 pontos (17-35). Todas as fraturas consolidaram. Em tres pacientes a fratura consolidou em varo. Nesses, o indice da UCLA medio foi de 27 pontos. CONCLUSAO: A osteossintese com a placa Philos permite fixacao estavel com bom resultado funcional.

OSTEOSYNTHESIS OF PROXIMAL HUMERAL END FRACTURES WITH FIXED-ANGLE PLATE AND LOCKING SCREWS: TECHNIQUE AND RESULTS

Describe the results of proximal humeral fractures surgically treated with the Philos locking plate system. Method: Between March 2003 and October 2004 we prospectively reviewed 24 of 26 patients with proximal humerus fractures treated with a Philos plate. The mean follow-up time was 12 months and the mean age of patients was 57 years. Six patients had four-part proximal humerus fractures, 11 patients had three-part proximal humerus fractures, and nine patients had two-part proximal humerus fractures. Clinical evaluation was performed using the University of California at Los Angeles (UCLA) criteria. Results: The mean UCLA score was 30 points (17-34). All fractures showed union. Three patients showed fracture union at varus position. The mean UCLA score for these patients was 27 points. Conclusion: Osteosynthesis with Philos plate provides a stable fixation method with good functional outcome.

Biomechanical comparison of a unique locking plate versus a standard plate for internal fixation of proximal humerus fractures in a cadaveric model

Newer internal fixation devices with a locking mechanism between the plate and the screw have recently been released. The efficacy of these plates in the proximal humerus has yet to be fully described. There is a need to compare the biomechanical properties of efficacy of plate fixation with or without locking screws for surgery of two-part proximal humerus fractures. Multiple-plane locking plate and cloverleaf plate designs were tested to determine their ability to maintain fixation on the humeral head. Eight matched pairs of cadaveric shoulders with 7-millimeter osteotomy defects at the surgical neck simulating two-part fractures of the proximal humerus were loaded to failure in thirty degrees of glenohumeral abduction. One side was repaired with a proximal humerus locking plate and the other with a cloverleaf plate. The rotator cuff musculature was then loaded via a servo-hydraulic testing machine under displacement control to simulate the deforming forces present in vivo. The average maximum load to failure was greater in proximal humerus locking plates than in cloverleaf plates (876 versus 712; P=0.04). In the cadaveric, two-part proximal humerus fracture model that was created, the locking plate displayed significantly greater holding power of the humeral head. Clinical relevance is unproven but may be manifested in vivo as improved early range of motion exercises and functional outcome.

The epidemiology of multifocal upper limb fractures.

The aim of this study is to identify the epidemiology of multifocal upper limb fractures and define any commonly occurring patterns. Patients included were those over the age of 13 years who presented to one orthopaedic trauma unit, in an eight-year period, and who sustained a multifocal upper limb fracture. There were 83 patients with 171 multifocal upper limb fractures. Mean age 60 years; range 13 to 92 years. 78 patients had bifocal fractures and 5 had trifocal. The most common pairing of fourteen different combinations was distal radius and proximal humerus. All but nine patients had involvement of the proximal humerus or distal radius. The most common injuries were the two-part proximal humerus fracture, the simple intra-articular olecranon fracture and the extra-articular fracture of the distal radius with metaphyseal comminution. This study has shown that multifocal fractures of the upper limb are most likely to occur in the middle aged to elderly women who have had a fall from standing height. As previously demonstrated osteopenic fractures are increasing in incidence in developed countries, where the population is ageing, which implies that the incidence of multifocal fractures of the upper limb is likely to increase.

Technique for Unstable Two-Part Surgical Neck Proximal Humeral Fractures Utilizing an Intramedullary Staple Device

This article presents a simple technique for treatment of the unstable two-part proximal humerus fracture. Currently, many methods exist to treat this type of injury. This method of intramedullary treatment allows for immediate stabilization and early motion. The procedure has been used successfully in 12 patients with a minimum follow-up of 2 years. Fracture union was achieved in all twelve cases at an average of 3 months. Seven patients reported excellent results, three reported good results, and two reported satisfactory results. Complications included one case of varus malreduction and one case of impingement-like symptoms requiring a second procedure to remove the staple. The Evan's staple can be inserted through a 2 cm incision with minimal disruption of the soft tissues. The procedure is simple to perform and provides predictable postoperative outcomes.

Two-part fractures of the proximal humerus

Between 1981 and 1991, 137 patients had 141 two-part proximal humerus fractures. One hundred thirteen surgical neck, 24 greater tuberosity, 2 anatomic neck, and 2 lesser tuberosity fractures were studied. Eleven patients had died in the interim; the remaining cases were reviewed. The mean age of patients with surgical neck fractures was 57 years (range 20 to 91 years), and 62.8% (71 cases) were women. In 38% of cases there was another significant medical problem. Eighty (70.8%) cases were treated with a sling and early isometric and pendulum exercises. Bony union was obtained in an average of 3.2 months (range 2 to 8 months), and 87.5% achieved satisfactory function. The mean age of patients with greater tuberosity fractures was 37 years (range 20 to 59 years), and 79.2% (19 cases) were men. Ten (41.7%) cases were treated with open reduction and internal fixation, and the remainder were treated without surgery. All patients improved to a satisfactory level of function. Anatomic neck fractures (two) were treated with surgery. Lesser tuberosity fractures (two) were treated conservatively and had good functional results. It appears that conservative measures when coupled with early isometric and pendulum exercises produce a satisfactory result in surgical neck fractures. Similarly, conservative treatment for nondisplaced greater tuberosity fractures and operative intervention for displaced fractures resulted in satisfactory function. Lesser tuberosity fractures without limitation of motion appear to do well with a sling and early motion.