Internal fixation of the distal humerus: a biomechanical comparison of methods

Biomechanical Design Optimization of Distal Humerus Fracture Plates: A Review

The goal of this article was to review studies on distal humerus fracture plates (DHFPs) to understand the biomechanical influence of systematically changing the plate or screw variables. The problem is that DHFPs are commonly used surgically, although complications can still occur, and it is unclear if implant configurations are always optimized using biomechanical criteria. A systematic search of the PubMed database was conducted to identify English-language biomechanical optimization studies of DHFPs that parametrically altered plate and/or screw variables to analyze their influence on engineering performance. Intraarticular and extraarticular fracture (EAF) data were separated and organized under commonly used biomechanical outcome metrics. The results identified 52 eligible DHFP studies, which evaluated various plate and screw variables. The most common plate variables evaluated were geometry, hole type, number, and position. Fewer studies assessed screw variables, with number and angle being the most common. However, no studies examined nonmetallic materials for plates or screws, which may be of interest in future research. Also, articles used various combinations of biomechanical outcome metrics, such as interfragmentary fracture motion, bone, plate, or screw stress, number of loading cycles to failure, and overall stiffness (Os) or failure strength (Fs). However, no study evaluated the bone stress under the plate to examine bone "stress shielding," which may impact bone health clinically. Surgeons treating intraarticular and extraarticular distal humerus fractures should seriously consider two precontoured, long, thick, locked, and parallel plates that are secured by long, thick, and plate-to-plate screws that are located at staggered levels along the proximal parts of the plates, as well as an extra transfracture plate screw. Also, research engineers could improve new studies by perusing recommendations in future work (e.g., studying alternative nonmetallic materials or "stress shielding"), clinical ramifications (e.g., benefits of locked plates), and study quality (e.g., experimental validation of computational studies).

Biomechanical analysis of different osteosynthesis configurations in the pin and plate fixation method for distal humerus fractures

Distal humerus fractures commonly occur in adults with low bone mineral density causing major technical challenges for orthopedic surgeons. Persian fixation method was introduced as a novel technique to stabilize small fragments in comminuted distal humerus fractures using a set of K-wires and a reconstruction plate. The present study aims to measure this technique's stiffness and stability of this technique and analyze the effect of influential parameters with numerical simulation and biomechanical testing on a cadaveric specimen. Validation of the finite element (FE) model was conducted based on results of experiments. The results indicated that Delta configuration mainly led to a higher stiffness in the case of axial loading and anterior bending compared to L configuration. Analyzing the influential factors of this technique suggests that changes in diameter and number of K-wires have a similarly significant effect on the construct stiffness while the height of plate had a slight influence. Also, the diameter of wires was the most effective parameter for implant failure, particularly in the 3-pin construct, which caused a reduction in failure risk by about 60%. The results revealed that the Persian fixation method would achieve suitable stability compared to the dual-plating technique.

Double Plating in Type C Distal Humerus Fractures: Current Treatment Options and Factors that Affect the Outcome

Purpose

This is a retrospective cohort study of type C distal humeral fractures (AO classification system) aimed at evaluating the effectiveness of current operative treatment options.

Materials and methods

Thirty-seven patients with type C distal humeral fractures, treated operatively from January 2002 to September 2016, were retrospectively studied. Thirty-two were eligible for inclusion. Patients were treated by open reduction using the posterior approach, olecranon osteotomy and parallel-plate two-column internal fixation. Patients were evaluated for fracture healing, functional outcomes and complications (infection, ulnar neuropathy, heterotopic ossification and need for implant removal). Restoration of the normal anatomy was defined by measuring carrying angle, posterior angulation and intercondylar distance of distal humerus.

Results

The mean follow-up time was 8.7 years [range 2–15.5 years, standard deviation (SD) = 3.96]. Mean time to fracture union was 8 weeks for 29 patients (90.6%) (range, 6–10 weeks). In nine cases, there was malunion of varied importance (28.1%). There was one case with postoperative ulnar neuropathy and one case with deep infection. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score and mean Mayo Elbow Performance Score (MEPS) were 20 (range 0–49) and 83.3 (range 25–100), respectively.

Conclusion

In complex distal humerus fractures, the posterior approach with olecranon osteotomy and parallel plating of two columns, after anatomic reconstruction of the articular segment, is a prerequisite for successful elbow function.

How to cite this article

Athanaselis ED, Komnos G, Deligeorgis D, et al. Double Plating in Type C Distal Humerus Fractures: Current Treatment Options and Factors that Affect the Outcome. Strategies Trauma Limb Reconstr 2022;17(1):7–13.

Intra-articular Distal Humerus Fractures: Parallel Versus Orthogonal Plating

Background: Dual-plating osteosynthesis is the standard treatment for Orthopedic Trauma Association (OTA)-type 13-C distal humerus fractures. However, optimal plate position is debated. Purpose: The purpose of this study was to evaluate dual-plate positioning following intra-articular distal humerus fracture repair by comparing outcomes between patients plated in parallel and those plated orthogonally following open-reduction, internal-fixation (ORIF) of intra-articular distal humerus fractures. Methods: All OTA-type 13-C intra-articular distal humerus fractures treated operatively at our institution over a 10-year period were reviewed. Clinical outcomes and complications were compared between those plated in parallel and those plated orthogonally. Data were analyzed using independent-samples t-tests, Mann-Whitney U tests, chi-square tests, and Fisher's exact tests. Results: A total of 69 patients met inclusion criteria. Mean follow-up among this cohort was 19.3 months; 45 (64.8%) patients had orthogonal dual plating, and 24 (35.2%) had parallel plating. Groups did not differ with respect to demographics or duration of follow-up. Clinically, there were no significant differences in time to union, elbow arc of motion at any time point, or patient Mayo Elbow Performance Index (MEPI) scores at final follow-up. Furthermore, there were no differences in complications. Conclusion: Parallel and orthogonal plating following ORIF of distal humerus fractures with modern, contoured locking compression plates had similar outcomes in this study. This study represents the largest comparative series in the literature at the time of its writing. Both techniques may be considered when deciding on dual-plating technique for treating intra-articular distal humerus fractures.

Does posterior configuration have similar strength as parallel configuration for treating comminuted distal humerus fractures? A cadaveric biomechanical study

BACKGROUND

The posterior plating technique could be used as a clinical alternative to parallel plating for treating comminuted distal humerus fractures (DHFs) successfully with good clinical results. However, the biomechanical characteristics for posterior fixation are still unclear. The purpose of this study is to evaluate the biomechanical properties of the posterior fixation and to make comparisons between the parallel and the posterior fixation systems.

MATERIALS AND METHODS

We performed a cadaveric biomechanical testing with two posterior plating systems (a posterior two plating and a single posterior pre-contoured Y plating system) and one parallel two plating system to treat AO/OTA type-C2.3 DHFs. Among three groups, we compared construct stiffness, failure strength, and intercondylar width changes after 5000-cycle fatigue loading and failure loads and failure modes after destructive tests in both the axial compression and (sagittal) posterior bending directions. The correlations between construct failure loads and bone marrow density (BMD) were also compared.

RESULTS

In axial direction, there were no significant differences in the stiffness and failure load between the posterior and the parallel constructs. However, in sagittal direction, the two-plate groups (posterior two plating and parallel plating group) had significant higher stiffness and failure loads than the one-plate group (single posterior Y plating). There was no fixation failure after 5000-cyclic loading in both directions for all groups. Positive correlation was noted between BMD and failure loads on parallel fixation.

CONCLUSIONS

We found that when using two plates for treating comminuted DHFs, there were no significant differences in terms of most biomechanical measurements between posterior and parallel fixation. However, the single pre-contoured posterior Y plate construct was biomechanically weaker in the sagittal plane than the parallel and the posterior two-plate constructs, although there was no fixation failure after the fatigue test for all groups regardless of the fixation methods.

LEVEL OF EVIDENCE

Biomechanical study.

A pilot biomechanical study comparing a novel, intramedullary Nail/Plate construct to standard Dual-Plate fixation of intra-articular C2.3 distal humerus fractures

BACKGROUND

The gold-standard treatment for intra-articular distal humerus fractures (DHFs) is dual-plate/dual-column fixation, though optimal orientation is not yet established. With a superior method not yet identified, we propose a load-sharing construct, combining absolute stability (extramedullary plate fixation) for distal articular fragments and relative stability (load-sharing intramedullary nail) for the metaphyseal segment. The purpose of this pilot study was to evaluate the biomechanical performance of a novel implant compared to orthogonal dual-plating.

MATERIALS AND METHODS

Ten fresh-frozen matched-pairs of human cadaveric upper extremities with no prior elbow pathology/surgery were used. Pairs were randomized into two groups: Dual-Plate (medial and posterolateral) or novel Nail/Plate (cross-locked medial nail and posterolateral plate). AO/ASIF type 13-C2.3 multifragmentary fractures with simulated metaphyseal comminution. Biomechanical testing included stiffness (MPa) and load to failure (Newtons) in axial (100 cycles at 3 Hz at 20 N increments from 20 to 100 N) and coronal (varus/valgus; 4,000 cycles from 50N-100 N at 3 Hz) planes. Failed specimens were not analyzed and mechanisms were identified. For all failures, mechanisms were identified and reviewed by three consultant surgeons for revision vs. immobilization, to attempt to recreate a real-world scenario. All outcomes were compared between groups.

RESULTS

During stiffness testing, zero Nail/Plate specimens failed, but two (20%) Dual-Plate specimens failed (mechanisms: fracture diastasis; bone collapse and intussusception into osteotomy, yielding articular congruency loss). For remaining samples, Nail/Plate (n = 10) coronal (varus/valgus) stiffness was comparable to Dual-Plate (n = 8) constructs (41.5 vs. 39.0 MPa, p = 0.440). Remaining Dual-Plate constructs had greater axial overall stiffness than Nail/Plate (118.3 ± 48.3 vs. 95.6 ± 34.7 MPa, p = 0.020). Failure loads were comparable between Nail/Plate and Dual-Plate constructs (1,327.8 vs. 1,032.4 N, p = 0.170). Individual nail yield strength ranged from 1,101.1-1,124.4 N (n = 2). In review of all failures, the most common overall mechanism was fracture/osteotomy site posterolateral plate bending. Revision recommendation rate was comparable between constructs (Nail/Plate, 22.2% vs. Dual-Plate, 44.4%, p>0.05).

CONCLUSIONS

The novel Nail/Plate construct demonstrated non-inferior coronal (varus/valgus) stiffness, despite producing lower axial stiffness than orthogonal dual-plating, potentially due to the load-sharing cross-locked design. Considering comparable biomechanical performance, with no failures and comparable recommendations for revision, this novel construct warrants further evaluation as an alternative to the gold-standard, dual-plate fixation method for intra-articular distal humerus fractures.

LEVEL OF EVIDENCE

N/A.

A Limited Fixation, Olecranon Sparing Approach, for Management of Geriatric Intra-Articular Distal Humerus Fractures

Purpose

We propose that geriatric comminuted intra-articular distal humerus fractures can be effectively treated with a limited fixation approach aimed at achieving varus/valgus stability with columnar fixation, but allowing intra-articular comminution to heal by secondary congruency against an intact olecranon, thus avoiding an olecranon osteotomy.

Methods

Fifty-six elderly patients with AO 13-C type fractures, who underwent surgical fixation with ≥12-months of follow-up were retrospectively reviewed. Thirty patients were treated with intra-articular open reduction internal fixation (ORIF) with an olecranon osteotomy and 26 patients were treated with our limited fixation (L-ORIF) approach. Outcomes were range of motion (ROM), complications, additional surgery, and patient-reported outcome measures (PROMIS).

Results

At final follow-up, the average elbow ROM was 97° (40°-155°) in the ORIF group and 86.5° (20°-145°) in the L-ORIF group. There was a trend toward more complications and additional surgery in the ORIF group. PROMIS scores for pain were 53.1 and 52.14, and PROMIS functional scores were 41.7 and 41.4 in the ORIF and L-ORIF group respectively. No differences in outcomes were statistically significant.

Conclusion

A limited fixation technique based on achieving varus/valgus stability with columnar fixation, demonstrated equivalent outcomes in elderly patients with intra-articular distal humerus fractures when compared to intra-articular ORIF with an olecranon osteotomy.

Comparison of olecranon fixation techniques following transolecranon approach in intra-articular fractures of distal humerus in adult patients

Background:

In this study, we assessed functional outcomes among olecranon fixation techniques used following transolecranon approach in patients with comminuted fracture of distal humerus.

Methods:

The study included 37 elbows that underwent olecranon osteotomy due to distal humerus fracture. Functional outcomes were assessed among patients who underwent fixation via tension band technique, plate, or screw fixation.

Results:

The implant irritation was seen in 18% of patients who underwent K-wire plus tension band fixation, in 75% of patients who underwent olecranon plate plus screw fixation, and in 18% of patients who underwent cancellous screw fixation. The rate for implant removal was 2.6 folds lower in K-wire plus tension band fixation when compared to olecranon plate plus screw fixation.

Conclusion:

We concluded that K-wire plus tension band technique and cancellous screw fixation performed in accordance with technical principles caused less skin problem when compared to other techniques. In olecranon fixation, both methods with enhanced stability by tension band can be preferred.

Dual plate fixation results in improved union rates in comminuted distal femur fractures compared to single plate fixation

Purpose

The treatment of distal femur fractures with extensive metaphyseal comminution is frequently complicated by high rates of nonunion and varus collapse. Dual plating with lateral and medial locking plates for these types of fractures has shown promising results in the recent literature. We hypothesize that dual plating of comminuted distal femur fractures leads to higher union rates and lower revision rates compared to an isolated lateral locking plate.

Methods

A retrospective medical chart review between January 2015 and December 2017 was conducted. Inclusion criteria included patients 18 years of age and older who sustained a complex distal femur fracture (AO/OTA 33-C2/33-C3 or periprosthetic fracture with significant metaphyseal comminution) and at least 6 months of follow up. Patients with simple fracture patterns, alternative fixation methods, and inadequate follow up were excluded. All patients in the single plating group were treated with a lateral distal femoral locking plate using a lateral approach. In the patients treated with dual plating, an extensile parapatellar approach was utilized for fracture reduction and placement of an adjunctive medial plate. Demographic information, fracture types, injury severity score (ISS), medical comorbidities, type of surgical fixation, union rates, complications, knee range of motion, time to follow up, and need for revision surgery were extrapolated from the medical charts for analysis.

Results

Twenty-one patients were included in the study. Thirteen patients underwent single plate fixation and 8 underwent dual plate fixation. There were no significant differences in demographics, number of co-morbidities, fracture classification, or ISS between single and dual plate groups (p > 0.05 for all). There was a statistically significant difference in union rates between the single plate group (6 nonunions, 4 unions, and 3 delayed unions) and the dual plate group, with no nonunions or delayed unions (p = 0.0049). Although not statistically significant, 4 patients treated with single plating underwent revision ORIF, compared to none in the dual plating group (p = 0.13). There were no significant differences in time to follow up, time to full weight bearing, or infection rates (p > 0.1 for all).

Conclusion

Based on these results, the medial and lateral locked plating technique demonstrates a higher union rate, with possible lower rates of revision surgery, compared to a single lateral plate in highly comminuted distal femur fractures.

Level of evidence

Level 3. Retrospective Cohort Study.

Orthogonal plating method versus parallel plating method in the treatment of distal humerus fracture: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis was performed to investigate the outcomes of orthogonal plating method and parallel plating method in the treatment of distal humerus fracture from the current literatures.

METHODS

The electronic literature database of Pubmed, Embase, and Cochrane library were searched in November 2018. The data operation time, union time, Mayo Elbow Performance Score (MEPS), range of motion (ROM) of elbow, arc of elbow flexion, arc of elbow extension, rate of excellent and good results and complications (including heterotopic ossification, transient ulnar nerve neuropathy and ankylosis) were extracted. Stata 14.0 software was used for our meta-analysis.

RESULTS

A total of 8 studies including 6 RCTs and 2 cohort studies met our inclusion criteria. This meta-analysis showed that there was no significant difference between the two groups regarding operation time, MEPS, ROM of elbow, arc of elbow flexion, arc of elbow extension and rate of excellent and good results at final follow-up (P = 0.50, P = 0.39, P = 0.87, P = 0.18, P = 0.58 and P = 0.59 respectively). However, the present meta-analysis demostrated that parallel plating method had significantly shorter union time than orthogonal plating method (P = 0.018). As for the complications (heterotopic ossification, transient ulnar nerve neuropathy and ankylosis), there was no significant difference between the two groups (P = 0.89, P = 0.08 and P = 0.29 respectively).

CONCLUSION

Our meta-analysis suggested that both orthogonal plating and parallel plating method could achieve satisfactory outcomes with the similarly low complications in the treatment of distal humerus fracture. More RCTs are required for further research.

Use of the Minimally Invasive Reduction Instrumentation System for Facilitating Alignment and Reduction When Performing Minimally Invasive Plate Osteosynthesis in Three Dogs

The Minimally Invasive Reduction Instrumentation System (MIRIS) was utilized to facilitate minimally invasive plate osteosynthesis (MIPO) of distal limb diaphyseal comminuted fractures (2 crural, 1 antebrachial) in three dogs. The MIRIS facilitated efficient MIPO in all three fractures. Radial and tibial lengths were restored within 2% of the length of the intact bone and postoperative frontal and sagittal plane angulation were within 3° of the normal contralateral limb for each of the fractures. Fixation failed in one of the tibial fractures when the plates bent a week following surgery. The implants were removed and the fracture was restabilized via MIPO facilitated by the MIRIS. Inappropriate implant selection was considered the primary reason for implant failure. All three fractures achieved union by 10 weeks following surgery. The dog that underwent revision surgery developed a surgical site infection 5 months following revision surgery, which necessitated implant removal. All three dogs had excellent limb function at the time of the final evaluation. This system resulted in reductions that were near anatomic, with acceptable restoration of length and alignment and excellent limb function.

Parallel versus orthogonal plate osteosynthesis of adult distal humerus fractures: a meta-analysis of biomechanical studies

PURPOSE

There are two widely used distal humerus fracture (DHF) fixation methods with either orthogonal or parallel double-plate osteosynthesis. However, biomechanical studies have shown inconsistent results on which technique is more effective. We performed a meta-analysis to compare these two fixation methods for adult DHF fixation.

METHODS

We searched the literature for entries discussing the biomechanical testing of orthogonal and parallel fixation techniques for DHFs. We then performed a meta-analysis of the following biomechanical outcome measures: axial/sagittal/coronal/torsional stiffness, load to failure, and torque to failure.

RESULTS

Seventeen studies comparing both constructs were included. The parallel configuration exhibited greater mechanical strength with respect to axial stiffness/load to failure, torsional stiffness, and posterior bending load to failure than the orthogonal constructs. Subgroup analysis revealed that parallel constructs also had higher torsional stiffness in supracondylar fractures.

CONCLUSIONS

This meta-analysis shows that parallel constructs provide greater axial stiffness, axial strength, and torsional stiffness than orthogonal plate for DHF fixation. A subgroup analysis revealed that parallel constructs had better torsional stiffness in supracondylar fracture fixation.

LEVEL OF EVIDENCE

IA.

SURGICAL MANAGEMENT OF APPENDICULAR LONG-BONE FRACTURES IN FREE-RANGING FLORIDA PANTHERS ( PUMA CONCOLOR CORYI): SIX CASES (2000-2014)

The clinical outcomes of six free-ranging Florida panthers ( Puma concolor coryi) that underwent surgical stabilization of appendicular long-bone fractures (three femoral fractures, one tibial and one tibial and fibular fracture and two radial and ulnar fractures) were evaluated. These panthers presented to the University of Florida from 2000-2014. Estimated age of the panthers ranged from 0.5 to 4.5 yr, and weights ranged from 22 to 65 kg. Causes of injuries were vehicular collision ( n = 4) and capture related ( n = 2). All panthers underwent open reduction and fracture stabilization. Fixation failure necessitated three subsequent surgeries in one panther. Five panthers survived the immediate postoperative period, and all of these panthers' fractures obtained radiographic union (range, 8-36 [mean, 22] wk). The five surviving panthers underwent convalescence for 7-14 mo at White Oak Conservation Center before being released back into the wild; however, one panther was killed when hit by a car 3 days after release. The remaining four panthers were tracked for up to 106 mo in the wild and successfully integrated back into the native population. Surgical stabilization of appendicular long-bone fractures in free-ranging Florida panthers can be successful, but must take into account the stress that a large, undomesticated felid will place on the stabilized limb during convalescence as well as the difficulties involved in rehabilitating a wild panther in captivity.

Evaluation of Outcomes of Open Reduction and Internal Fixation Surgery in Patients with Type C Distal Humeral Fractures

Background:

In this study, functional state of patients with Type C distal humerus fractures undergone surgical plating was evaluated 6 and 12 months after the surgery in order to record postsurgical factors such as pain level and job/performance satisfaction.

Materials and Methods:

In this cross-sectional study, 46 patients with humerus fractures were recruited and their ability to do daily tasks, presence of degenerative changes, stability of elbow joint, and range of motion was evaluated. For assessment of response to surgery, Mayo score was used.

Results:

Among 46 patients, 45 (97.8%) of them had joint stability. Evaluation of postsurgical complications showed that six subjects (13%) had no complications, but superficial infection was observed in 12 (26.1%) subjects. Neuromuscular disorders in ulnar nerve were present in 11 subjects (23.9%), recurrent articular bursitis of elbow joint in 6 subjects (13%), stiffness of elbow joint in 29 subjects (63%), nonunion of fracture in 3 subjects (6.5%), and myositis ossification in 4 (8.7%) subjects. Furthermore, 18 (39.1%) patients presented with more than one (2–4) complications.

Conclusion:

Open reduction and internal fixation surgery with dual plating is the method of choice for treatment of Type C distal humeral fractures. Evaluation of long-term outcomes of this surgery could be done via several different questionnaires as many studies suggest. This study demonstrated that the outcomes of this surgery in Isfahan, Iran, have been noticeably inferior compared to results of the studies in other parts of the world.

Intra-articular fractures of the distal humerus-a review of the current practice

Intra-articular fractures of the distal humerus are complex injuries that can considerably limit elbow function if not treated appropriately. Surgical management is indicated for most intra-articular distal humerus fractures with the goal of restoring elbow range of motion and function. Open reduction and internal fixation (ORIF) with plates and screws has been the preferred surgical option. Double plating is recommended for bicolumnar fractures and plates can be applied either parallel or orthogonal to each other. Surgical approach for ORIF of the distal humerus can be performed through an olecranon osteotomy, but other approaches that preserve the olecranon are also in use, such as the triceps-reflecting, triceps-splitting, paratricipital, and triceps-reflecting anconeus pedicle approach. The ulnar nerve is identified during the approach, followed by either in situ decompression or anterior transposition. Elbow arthroplasty has also emerged as a viable alternative to ORIF for fixation of these fractures in elderly patients with poor bone quality.

Challenges and Solutions in Management of Distal Humerus Fractures

Background

Management of distal humerus fractures remains a challenge for trauma surgeons and advancements in treatment options continue to be made to achieve the best results for patients presenting with these complex fractures. Our aim in this article is to provide the surgeons with a detailed review of current literature to help them make an evidence based decision when faced with managing such complex injuries in their surgical practice.

Methods

This is a comprehensive review of the current literature that details various aspects of distal distal humerus fractures such as classification, surgical anatomy, surgical approaches, treatment options, choices of devices, outcomes and complications.

Results

With the advancements in techniques and equipment, there has been improvement in patients' outcomes following surgical management of these fractures and a large proportion of these patients are able to achieve pre-injury level of function. The contoured locking plates have enabled successful fixation of many of these fractures that were previously considered unfixable. For those not amenable to surgical fixation, total elbow arthroplasty and elbow hemiarthroplasty are considered as good alternatives.

Conclusion

Since the days where the 'bag of bones' technique was the preferred method of treating these complex injuries, techniques and outcomes have advanced greatly. However, they still present a significant technical challenge and need meticulous technique and experience to achieve optimal results.

Double plating as treatment for supracondylar humeral fractures

INTRODUCTION AND OBJECTIVES

Supracondylar humeral fractures represent only about 0.5-1% of all fractures in adults. The objective of this study is to evaluate functional outcome and quality of life in patients treated with open reduction and internal fixation using double plates.

MATERIAL AND METHODS

We designed a retrospective descriptive study including 27 supracondylar humeral fractures treated with open reduction and internal fixation using two anatomic plates from January 2005 to September 2012. Mean age was 56 ± 22.9 years including 14 female and 13 male. All fractures were classified using the AO classification. Average follow-up was of 41 ± 23.9 months. Fracture union was evaluated with x-ray exams and functional outcome using the Mayo Elbow Performance Score (MEPS). Quality of life was evaluated using the Short Form-36 survey.

RESULTS

Union at 6 months was achieved in 96% of all fractures. Average range of motion was 102° (70°-140°) and average MEPS 86 points (60-100). Mean score on SF-36 was 54.87 (8.66-89.22) the older patients had lower scores. Sixty percent of patients (15 of 25) were able to return to previous activity. No infection was reported. Two patients required surgical treatment due to a stiff elbow.

CONCLUSIONS

Open reduction and internal fixation using double plates in supracondylar humeral fractures obtains a high union rate allowing excellent functional and radiological outcomes.

Bicolumnar 90-90 plating of AO 13C type fractures

Objective

The aim of this study was to evaluate functional results and complication rate of patients who underwent medial-dorsolateral plating for intra-articular distal humeral fracture (Müller AO type 13C).

Methods

Twenty-four patients (14 men, 10 women; mean age: 47 years) with AO type 13C distal humerus fracture were included in the study. Mean follow-up time was 28 months. Nine patients were in 13C1 subgroup, according to AO classification system, 11 patients were categorized as 13C2, and 4 patients were 13C3. Final follow-up assessment of outcomes included Broberg and Morrey radiological criteria; Mayo Elbow Performance Score, disabilities of the Arm, Shoulder and Hand (DASH) Outcome Measure, score based on Jupiter criteria; and range of motion (ROM) values.

Results

The mean carrying angle of operated elbows was 11.37° (range: 0-20°). According to Broberg and Morrey radiological criteria, 14 patients, had radiologically normal elbow, 4 patients had mild change, 3 patients had moderate change, and 3 patients had severe radiological change. Mean DASH score was 21.91 (range: 0-50), and mean Mayo rating was 83.37 (range: 55-100). Jupiter criteria evaluation revealed excellent results in 10 cases, good in 12, and fair results in 2. One patient with fair result had open fracture, and the other had previous hemiparesis in the same extremity. There was no instance of nonunion observed at follow-up.

Conclusion

Osteosynthesis with medial-dorsolateral plating is a safe and effective method for the treatment of intra-articular fractures of distal humerus.

Level of evidence

Level IV, Therapeutic study.

Biomechanical comparison of orthogonal versus parallel double plating systems in intraarticular distal humerus fractures

OBJECTIVES

In intraarticular distal humerus fractures, internal fixation with double plates is the gold standard treatment. However the optimal plate configuration is not clear in the literature. The aim of this study was to compare the biomechanical stability of the parallel and the orthogonal anatomical locking plating systems in intraarticular distal humerus fractures in artificial humerus models.

METHODS

Intraarticular distal humerus fracture (AO13-C2) with 5 mm metaphyseal defect was created in sixteen artificial humeral models. Models were fixed with either orthogonal or parallel plating systems with locking screws (Acumed elbow plating systems). Both systems were tested for their stiffness with loads in axial compression, varus, valgus, anterior and posterior bending. Then plastic deformation after cyclic loading in posterior bending and load to failure in posterior bending were tested. The failure mechanisms of all the samples were observed.

RESULTS

Stiffness values in every direction were not significantly different among the orthogonal and the parallel plating groups. There was no statistical difference between the two groups in plastic deformation values (0.31 mm-0.29 mm) and load to failure tests in posterior bending (372.4 N-379.7 N). In the orthogonal plating system most of the failures occurred due to the proximal shaft fracture, whereas in the parallel plating system failure occurred due to the shift of the most distal screw in proximal fragment.

CONCLUSION

Our study showed that both plating systems had similar biomechanical stabilities when anatomic plates with distal locking screws were used in intraarticular distal humerus fractures in artificial humerus models.

Distal-third diaphyseal fractures of the humerus: choice of approach and surgical treatment

PURPOSE

Distal-third diaphyseal fractures of the humerus are often hard to treat due to location and pattern of the fractures, radial nerve injury, and quality of bone and age of patients. The aim of this retrospective study is to propose the best approach and the best surgical technique according to the pattern of extra-articular fracture of the distal humerus.

METHODS

We have treated 37 fractures of the distal humerus between January 2010 and July 2015 classified according to the AO classification. There were 2 open fractures. We treated all fractures with open reduction and internal fixation with plates and screws. In 20 cases, we performed a posterior midline triceps-splitting approach, with patients in prone decubitus position; in 2 cases, the triceps-splitting approach with the patients in supine decubitus position; in 3 cases, the olecranon osteotomy approach in prone decubitus position; and in 12 cases, the lateral approach in supine decubitus position.

RESULTS

Thirty cases had a medium follow-up of 6 months. We observe 2 post-operative radial nerve palsies healed in 5 months and 2 cases of non-union. The average time to union of remaining cases was 16 weeks (range 12-24). Elbow motility was complete in 25 cases, in 4 cases there was an extension loss of 5°, and in one case there was an extension loss of 10°.

CONCLUSIONS

The use of plates allows an anatomical fracture reduction, a better control of alignment of humerus and, with a rigid fixation, an early elbow mobilization. The best approach and the best surgical technique depend on the pattern of the fracture of distal humerus.

Distal humerus fractures: a review of current therapy concepts

Fractures of the distal humerus in the adult comprise approximately one third of all humeral fractures. Successful management of distal humerus fractures depends on correct reduction of the fracture, reconstruction of the articular surface if needed, stability and rigidity of the fixation, and appropriate rehabilitation. In this review, we evaluated the available literature and highlighted current therapy concepts. We assessed the evolution of internal fixation and elbow arthroplasty focusing on the established surgical approaches against the background of a growing incidence of distal humeral fractures in an aging patient population. Therefore evaluating the aspect and influence of age-dependent comorbidities like osteoporosis on successful treatment.

Parallel Plating of Simulated Distal Humerus Fractures Demonstrates Increased Stiffness Relative to Orthogonal Plating With a Distal Humerus Locking Plate System

OBJECTIVES

This study compared the stiffness of precontoured parallel and orthogonal locking plate configurations in cyclic torsion and bending, and then extension to failure.

METHODS

Tests were conducted on 9 matched pairs of cadaveric humeri. A 10 mm block of bone was excised from the distal humerus metaphysis to simulate comminution, and fractures were repaired in matched fashion using parallel or orthogonal Biomet ALPS distal humerus locking plates (Biomet, Inc, Warsaw, IN). Specimens were tested at 0.5 degree per second up to ±2 N-m in internal and external rotation for 20 cycles, then in flexion and extension cantilevered bending at 1 mm/s to ±50 N, followed by bending at 1 mm/s to failure in extension.

RESULTS

Torsional stiffness of the parallel configuration group was greater than the orthogonal configuration in both internal and external rotation (P < 0.0001). Also, stiffness in bending was significantly greater in the parallel configuration group in both flexion and extension (P < 0.0001). In extension to failure testing, the parallel plate construct stiffness was significantly greater than the orthogonal configuration (P < 0.005).

CONCLUSIONS

The parallel plate configuration demonstrated significantly greater stiffness than the orthogonal plate configuration in torsion and bending using locked distal humerus plates. This greater stiffness may prove desirable in the postoperative management of patients with comminuted distal humerus fractures, providing a stable anatomic reconstruction of the joint to allow early range of motion.

Distal Humerus Fractures: Open Reduction Internal Fixation

Distal humerus fractures are challenging injuries for the upper extremity surgeon. However, recent techniques in open reduction internal fixation have been powerful tools in getting positive outcomes. To get such results, the surgeon must be aware of how to properly use these techniques in their respective practices. The method of fixation depends on the fracture, taking the degree of comminution and the restoration of the columns and articular surface into account. This article helps surgeons understand the concepts behind open reduction internal fixation of the distal humerus and makes them aware of pitfalls that may lead to negative results.

Condylar orientation plating in comminuted intraarticular fractures of adult distal humerus

BACKGROUND

The condyles of the distal humerus have characteristic orientation in reference to the diaphysis. Anatomical reduction of the articular surface in intraarticular fractures of adult distal humerus does not always restore preinjury functional status. The purpose of this study was to determine the outcome of treating these fractures with technique of condylar orientation precontoured plating. The principle of the technique is to primarily restore the anatomical orientation of the reconstructed distal humeral condyle with the diaphysis of the humerus apart from anatomical reduction of fracture.

MATERIALS AND METHODS

Seventy one consecutive patients with comminuted intraarticular adult distal humerus fractures were treated with the condylar orientation plates, which were specifically designed between 1999 and 2009. 43 fractures were Association for osteosynthesis (AO) type C3, 24 were C2 and 4 were C1. Six were open cases and two were of nonunion distal end humerus. On medial and posterolateral side of the distal humerus, precontoured Sherman plates were applied. Patients were followed up for a mean of 3 years. They were assessed clinically (using mayo elbow performance score [MEPS]) and radio-graphically.

RESULTS

Sixty (84.5%) patients regained MEPS of 90 or more that is an excellent result (range of movement and functional status). One patient had nonunion with implant failure, and two patients developed heterotopic ossification. The mean MEPS was 95. Average extension and flexion was 15° and 133°. The result was graded as excellent in 60, good in 7, fair in 3 and poor in 1. At the time of most recent followup, 63 elbows were painless, and eight had mild pain.

CONCLUSION

Excellent pain free range of motion with a high rate of union can be achieved in comminuted intraarticular distal humerus fractures in adults with the use of condylar orientation precontoured plating technique. Condylar orientation is very important with perfect articular congruity in elbow motion.

Biomechanical testing of a novel osteosynthesis plate for the ulnar coronoid process

BACKGROUND

The present study aimed to biomechanically evaluate a novel locking plate intended for osteosynthesis of coronoid fracture compared to mini L-plates and cannulated screws.

METHODS

Biomechanical tests were performed on a fracture model in synthetic bones. Three groups, each with eight implant-bone-constructs, were analyzed in quasi-static and dynamic tests. Finally, samples were tested destructively for maximum strength.

RESULTS

The mean (SD) highest stiffness was measured for the novel plate [693 (18) N/mm], followed by the mini L-plate [646 (37) N/mm] and the cannulated screws [249 (113) N/mm]. During the cycling testing of the novel plate and the mini L-plate, no failures occurred, although three of the eight samples of cannulated screws failed during the test. The mean (SD) maximum strength during the destructive testing was 1333 (234) N for the novel plate, 1338 (227) N for the mini-L-plate and 459 (56) N for the cannulated screws. No statistical differences were found during the destructive testing between the two plates (p = 0.999), although statistical differences were found between both plates and the cannulated screws (p = 0.000 each).

CONCLUSIONS

Osteosynthesis of the coronoid process using the novel plate is mechanically similar to the mini L-plate. Both plates were superior to osteosynthesis with cannulated screws.

Internal fixation of the distal humerus: a comprehensive biomechanical study evaluating current fixation techniques

OBJECTIVES

The purpose of this study was to evaluate current fixation techniques in the operative fixation of distal humerus fractures, both with conventional and locked plating in both parallel and orthogonal orientation.

METHODS

Twenty-eight upper extremities from 14 cadavers were prepared to create 4 implant testing constructs: Synthes locking plates (IMP1) (medial and posterolateral with lateral flange), Acumed parallel locking plates (IMP2), Smith & Nephew orthogonal locking plates (IMP3), and Synthes orthogonal 3.5-reconstruction plating (IMP4) (1 posterolateral and 1 medial). A 5-mm supracondylar osteotomy was made to simulate the fracture. Stiffness in axial and sagittal plane loading, fatigue properties (over 5000 cycles), and ultimate strength were determined for each construct by biomechanical testing.

RESULTS

The parallel locking plates (IMP2) exhibited the highest stiffness in axial load and the highest ultimate strength (P < 0.05). No significant differences in sagittal plane stiffness and in the fatigue properties were seen across the locking plate groups, regardless of orientation. Locked plating constructs performed significantly better in all categories when compared with conventional nonlocked plating. Plastic deformation and implant loosening were the main modes of failure after ultimate strength test.

CONCLUSION

Parallel locking plate configuration showed significantly higher stiffness to axial load and ultimate failure strength when compared with orthogonal locked and nonlocked plating. Locked plating configurations performed significantly better than nonlocked plating configurations, regardless of orientation. Although parallel orientation seems biomechanically superior, translation to the clinical setting may prove difficult when taking surrounding soft tissue and exposure into consideration.

Comparative study of three models of extra-articular distal humerus fracture osteosynthesis using the finite element method on an osteoporotic computational model

INTRODUCTION

The biomechanical properties of extra-articular fractures of the distal humerus have not been researched sufficiently. The aim of the study was to examine three different models of osteosynthesis for extra-articular distal humerus fractures. Osteosynthesis with two parallel or perpendicular plates is a common method of osteosynthesis for those fractures. We wanted to examine the biomechanical performance of a newly designed Y plate, and compare it to the previously used osteosynthesis methods.

MATERIALS AND METHODS

On an osteoporotic computational model of the distal humerus, a 10 mm gap was made, 25 mm above the olecranon fossa, and osteosynthesis was performed with the newly designed Y-shaped plate and with 3.5 reconstruction plates in parallel and perpendicular configuration. The numerical simulations in axial compression, bending and varus loading were conducted using the finite element method.

RESULTS

On all models the largest displacements in the area of the fracture gap appear around the lower anterior edge. The parallel plate construct had the highest stiffness among the three plating techniques in axial compression. In bending and varus loading the construct with the newly designed plate had the highest stiffness, but in axial compression demonstrated the lowest. The parallel plate configurations had higher stiffness than the perpendicular ones in all three loading directions and the difference is most pronounced in axial compression.

CONCLUSION

The displacements that appeared in all three plating systems are minimal and within the limits that meet the requirements of sufficient biomechanical stability in the usual time for the healing of fractures in that region. The newly designed Y-shaped plate for extra-articular fractures of the distal humerus is a possible alternative to the usual method of osteosynthesis with two plates in the case of an extra-articular fracture of the distal humerus. Further biomechanical studies are needed for a decisive conclusion.

AO extra-articular distal humerus locking plate: extended spectrum of usage in intra-articular distal fractures with metaphyseal extension--our experience with 20 cases

BACKGROUND

LCP extra-articular plate designed by AO has been used in extra-articular fractures of the distal humerus, mal-unions, and nonunions of the distal humerus. They provide anatomically shaped and angular stable fixation system for extra-articular fractures of the distal humerus. We extended the usage spectrum of this plate to the extra-articular with intra-articular distal humerus fractures and compared it with the standard orthogonal locking plate fixation.

METHODS

We included 22 consecutive distal humerus intra-articular fractures with metaphyseal and diaphyseal extension into the study. Each case underwent osteosynthesis with LCP extra-articular plate fixation and augmented the intra-articular fragments with 4.0 mm partially threaded cancellous screws. The cost, surgical time, VAS, Modified Mayo Clinic Performance Index for elbow, and postoperative complications were recorded. The radiological union and postoperative elbow range of motion were assessed at 6 weeks, 6, and 12 months of follow-up. Twenty cases completed the scheduled follow-up. The results were compared with retrospective data of 20 cases from our institute where similar fractures were treated with standard orthogonal LCP distal humerus plate (LCPDHP).

RESULTS

The radiological union rates and the range of motion at 6 weeks, 6, and 12 months in both the groups were comparable and did not vary significantly (p > 0.05). The cost and operative time with the LCP extra-articular plates were significantly less (p < 0.05) when compared to the group LCPDHP.

CONCLUSION

The usage spectrum of extra-articular distal humerus locking plate can be extended to intra-articular fractures. It provides good results and significantly reduces the cost and operative time.

Intra-articular distal humerus fractures

Distal humeral fractures are relatively rare and complex injuries. With appropriate preoperative planning and execution of surgical technique, good outcomes may be obtained in most patients. Patients should be counseled regarding loss of motion in these injuries, and elderly, osteoporotic patients with extensive comminution should be considered for total elbow arthroplasty as an alternative to open reduction and internal fixation.

Distal humerus fractures in the elderly: osteosynthesis or endoprosthesis? Review of the literature

Fractures of the distal humerus in adults are rare but challenging for the orthopaedic trauma surgeon. The bimodal distribution reflects the trauma mechanism. While distal humerus fractures are caused by high-energy traumata in young male adults, a fall from a standing height is the most common reason for humerus fractures among elderly females. As a rule, fractures of the distal humerus are treated surgically. In young patients, open reduction and internal fixation (ORIF) with anatomic locking plates are the gold standard. In elderly patients, reconstruction is not always possible, and total elbow arthroplasty (TEA) becomes necessary. The present article provides an overview of the current diagnostic and treatment recommendations. The current literature is reviewed and the results discussed.

Biomechanical comparison of parallel versus 90-90 plating of bicolumn distal humerus fractures with intra-articular comminution

PURPOSE

To compare the biomechanical properties of 90-90 versus mediolateral parallel plating of C-3 bicolumn distal humerus fractures.

METHODS

We created intra-articular AO/Orthopaedic Trauma Association C-3 bicolumn fractures in 10 fresh-frozen matched pairs of cadaveric elbows. We determined bone mineral density of the metaphyseal region with dual-energy x-ray absorptiometry. The matched pairs of elbows were randomly assigned to either 90-90 or parallel plate fixation. We tested anteroposterior displacement at a rate of 0.5 mm/s to a maximum load of ± 100 N for both the articular and entire distal humerus segments. We tested torsional stability at a displacement rate of 0.1 Hz to a maximum torque of ± 2.5 Nm. After cyclical testing, we loaded the specimens in torsion to failure.

RESULTS

There was no significant difference in the bone density of the paired specimens. Compared with parallel fixation, 90-90 plate fixation had significantly greater torque to failure load. Both plating constructs were equally sensitive to bone density. Both techniques had the same mode of failure in torsion, a spiral fracture extending from the medial plate at the metaphyseal-diaphyseal junction. There was no significant difference in the stiffness of fixation of the articular fragment or the entire distal segment in anteroposterior loading.

CONCLUSIONS

This study demonstrated that 90-90 and parallel plating had comparable biomechanical properties for fixation of comminuted intra-articular distal humerus fractures, and that 90-90 plating had greater resistance to torsional loading.

Fragility fractures of the distal humerus

In light of the growing number of elderly osteopenic patients with distal humeral fractures, we discuss the history of their management and current trends. Under most circumstances operative fixation and early mobilisation is the treatment of choice, as it gives the best results. The relative indications for and results of total elbow replacement versus internal fixation are discussed.

Mid-term results of complex distal humeral fractures

The aim of this study was to assess outcomes following open reduction and internal fixation in complex fractures of the distal humerus. Between 2000 and 2006, 34 patients were operated for complex fractures of the distal humerus. Bone fixation was obtained with a reverse Y-shaped reconstruction plate in 13 cases and with double plating in 21 cases. At final follow-up, all the patients were assessed with the Mayo Elbow Performance Score. Satisfactory results were observed in 71% of the cases despite a high rate of complications. Age over 65 years is correlated with increased risk for an inferior postoperative result. Complex distal humeral fractures are difficult to treat and are associated with a high incidence of complications. It is therefore mandatory to obtain good anatomical reduction and a stable fixation of lateral and medial columns of the distal humerus. The results observed in older patients suggest that an alternative treatment for these patients may be joint replacement.

Locking and Non-locking Constructs Achieve Similar Radiographic and Clinical Outcomes for Internal Fixation of Intra-articular Distal Humerus Fractures

BACKGROUND

Locking plates have been used increasingly for the management of distal humerus fractures. Studies that compare patient-centered outcomes between locking and non-locking fixation for distal humerus fractures are lacking.

QUESTIONS/PURPOSES

The purposes of this study were to (1) determine whether locking plates offered superior fixation compared with non-locking plates for distal humerus fractures, (2) determine whether the use of locking plates was associated with fewer complications, and (3) determine whether locking plate use resulted in superior radiographic outcome compared with non-locking plates. Lastly, another aim was to determine the average cost difference associated with locking plate use versus non-locking plate use for distal humerus fracture fixation.

PATIENTS AND METHOD

Demographic, clinical, and radiographic data including loss of fixation, range of motion, rate of infection, nonunion and reoperation, as well as measures of fixation were collected retrospectively and compared on 96 patients with surgically treated AO type 13C distal humerus fractures (65 locking, 31 non-locking) at 6-week and 6-month follow-up. Average costs of locking and non-locking constructs were calculated and compared.

RESULTS

Three in 96 (3.1%) of all cases experienced loss of fixation, with no difference between the two groups. There was no difference between locking and non-locking groups with regard to the rate of nonunion, infection, and reoperation at 6 weeks and 6 months. On average, locking plate constructs were 348% more expensive than non-locking constructs.

CONCLUSION

While there are some significant differences in radiographic parameters and cost between locking and non-locking constructs for internal fixation of intra-articular distal humerus fractures, there were no statistically significant differences in clinical outcome.

Treatment of supra- and intra-articular fractures of the distal humerus with the LCP Distal Humerus Plate: a 2-year follow-up

BACKGROUND

The LCP Distal Humerus Plate (DHP) system represents an angular stable fixation system consisting of 2 anatomically pre-shaped orthogonal plates intended for the treatment of fractures of the distal humerus. The purpose of this retrospective study was to evaluate the clinical and radiologic outcome after a minimum follow-up of 2 years after open reduction and fixation of distal humeral fractures with this device.

METHODS

Twenty-two consecutive patients with distal humeral fractures were treated with the DHP system between January 2004 and June 2006. Of these, 16 could be clinically and radiologically evaluated after a mean follow-up of 30.5 months. Follow-up included anteroposterior and lateral radiographs; assessment of range of motion; pain according to a VAS; Disabilities of the Arm, Shoulder and Hand score; and Mayo Elbow Performance Score.

RESULTS

All fractures showed satisfactory articular reduction. One patient showed preoperative sensory ulnar neuropathy, which recovered incompletely, and two patients showed sensory ulnar neuropathy postoperatively, requiring revision surgery in one patient. Mean range of motion was as follows: flexion, 129°; extension, -16°; pronation, 82°; and supination, 71°. The mean visual analog scale score was 1 point; the mean Disabilities of the Arm, Shoulder and Hand score, 23.3 points; and the mean Mayo Elbow Performance Score, 84.7 points.

CONCLUSION

The DHP system represents a valuable tool to perform internal fixation of complex fractures of the distal humerus. In contrast to conventional plating, we did not observe any case of secondary fracture displacement, even in elderly patients with potentially reduced bone mass. The multiple angular stable point fixation also of small distal fragments seems to be effective in the application of this system.

Controversies in the management of intra-articular fractures of distal humerus in adults

BACKGROUND

The surgical approach, type of olecranon osteotomy, method of stabilization of osteotomy, type of fracture stabilization, orthogonal vs parallel plate fixation, need for transposition of ulnar nerve, place for primary total elbow replacement, and type of rehabilitation schedule after surgical fracture treatment are the controversial issues in the treatment of complex intra-articular distal humerus fractures (C2 and C3) in adults. Severe comminution, bone loss, and osteoporosis at the site of distal articular fractures of humerus often lead to unsatisfactory results due to inadequate fixation. We hereby report the outcome of a series of intracondylar fractures of the humerus treated by open reduction and internal fixation and discuss the controversies in light of published literature.

MATERIALS AND METHODS

One hundred and eighty-four patients of intra-articular fractures of distal humerus (C2 and C3) were operated by posterior transolecranon approach between January 1980 and December 2008. Initially, in the first part Chevron intra-articular osteotomy (n=108) was performed out of which 94 have been published in another publication. In later second part (1993 onward), extra-articular olecranon osteotomy (n=76) was routinely performed. Both columns were stably fixed by orthogonal methods; (n=174) however, during the last 2 years, in 10 patients with severe comminution with bone loss, stabilization was achieved by parallel plating. The osteotomy was routinely stabilized by tension band wiring with two parallel K-wires introduced up to the anterior ulnar cortex. The results were evaluated by the staging system of Caja et al. at a minimum follow-up of 2 years.

RESULTS

In the first part of the study (n=94), there was delayed union in 4% (n=4), with the fracture taking more than 20 weeks for union. There was delayed union of ulnar osteotomy (n=3) and failure of one tension band wiring, requiring revision. Some loss of motion was seen in 20% of cases and these patients did not achieve full flexion and extension. However, all these patients had useful range of function, with 20°-110° of flexion and full pronation-supination. As per the staging system of Caja et al., the results were in the range of excellent to good in 72% cases (n=67), fair in 19% (n=18), and poor in 9% patients (n=9). In the second part of study (n=90) dual plate fixation of both columns by orthogonal methods (n=80) and parallel plate fixation in 10 patients was performed. The results were excellent to good in 78 patients (86%).

CONCLUSIONS

The high rate of union can be achieved in complex intra-articular fractures of distal humerus if the proper principles of stable fracture fixation are followed, i.e., a posterior transolecranon approach and dual fixation of both columns and restoration of the continuity of articular surface. The stability achieved by this technique permits institution of early intensive physiotherapy to restore elbow function.

Dual plating for fractures of the distal third of the humeral shaft

In this study, we present a novel method for performing dual plating of extra-articular fractures of the distal third of the humerus. Since 2006, we have treated 15 such fractures with dual plates from a single posterior midline incision. In the first part of the study, we provide the surgical protocol we have used in addressing these fractures. In the second part, the charts of these patients were reviewed retrospectively to examine their clinical and radiographic outcomes. Using this technique, we have achieved an excellent union rate without significant complications while allowing early and aggressive range of motion.

Biomechanical evaluation of parallel versus orthogonal plate fixation of intra-articular distal humerus fractures

BACKGROUND

Orthogonal and parallel plate constructs are used for fixation of intra-articular distal humerus fractures but optimal plate configuration remains controversial. The purpose of this study was to compare the biomechanical properties of orthogonal versus parallel plate constructs in a cadaver distal humerus fracture model.

MATERIAL AND METHODS

An intra-articular distal humerus fracture with a metaphyseal defect was created in 14 matched pairs of cadaver elbows. Paired specimens were fixed with either orthogonal or parallel plates from a single elbow plating system using nonlocking screws. Using a novel testing protocol, loading was applied to the forearm and was transmitted to the distal humerus through intact collateral ligaments, olecranon, and radial head. Seven matched pairs were tested under varus loading and seven under axial/sagittal loading. Each specimen underwent cyclic loading first, followed by loading to failure.

RESULTS

Parallel plate constructs had significantly higher stiffness than orthogonal ones during cyclic varus loading (P = .002). Screw loosening occurred in all posterior plates of orthogonal constructs but in no plates of parallel constructs (P = .001). Parallel constructs had significantly higher ultimate torque in varus loading to failure (20.7 vs 15.9 Nm, P = .008), and higher ultimate load in axial/sagittal loading to failure (1287.8 vs 800.0 N, P = .03).

DISCUSSION

Parallel plating of intra-articular distal humerus fractures with a metaphyseal defect demonstrates superior biomechanical properties compared to orthogonal plating, and may be preferable for fixation of these fractures.

Anatomical plate configuration affects mechanical performance in distal humerus fractures

BACKGROUND

Because of strong loads acting in the elbow joint, intraarticular fractures with a methaphyseal comminuted fracture site at the distal humerus demand a lot from the osteosynthetic care. Ambiguities arise concerning to the anatomic position of the implants and the resulting mechanic performance. The aim of this biomechanical study was to compare the performance of different anatomical plate configurations for fixation of comminuted distal humerus fractures within one system.

METHODS

In an artificial bone model two perpendicular and one parallel plating configuration of a dedicated elbow plating system were compared with respect to system rigidity (flexion and extension) and dynamic median fatigue limit (extension). The flexion tests were conducted under 75° and the extension tests under 5°. Furthermore, the relative displacements were recorded. As a fracture model an AO C 2.3-fracture on an artificial bone (4th Gen. Sawbone) was simulated via double osteotomy in sagittal and transversal plane.

FINDINGS

Large differences in mechanical performance were observed between flexion and extension loading modes. In extension the parallel configuration with lateral and medial plates achieved the highest bending stiffness and median fatigue limit. In flexion the highest bending stiffness was reached by the construct with a medial and a postero-lateral plate. Failure of the implant system predominantly occurred at the screw-bone interface or by fatigue of the plate around the screw holes.

INTERPRETATION

All three plate configurations provided sufficient mechanical stability to allow early postoperative rehabilitation with a reduced loading protocol. Although the individual fracture pattern determines the choice of plate configuration, the parallel configuration with lateral and medial plates revealed biomechanical advantages in extension only.

Use of 2 column screws to treat transcondylar distal humeral fractures in geriatric patients

We describe fixation of transcondylar distal humeral fractures with column screws in geriatric patients and review our initial results. We conducted a retrospective review of a prospectively collected database at a Level I trauma center. Six patients met inclusion criteria of age older than 65 years and treatment of minimally or nondisplaced transcondylar distal humeral fracture with column screws only. All were closed fractures with no associated nerve injuries. One patient was lost to follow-up. The mechanism of injury was low-energy fall for the 5 remaining patients (average age, 74 y; age range, 70 to 83 y; average follow-up duration, 10.6 wk). One patient had a traumatic brain injury and a contralateral metacarpal fracture that was treated with internal fixation. The remaining 4 patients sustained isolated distal humeral fractures. No complications were noted, and all fractures healed at an average radiographic union time of 7.2 weeks. Average range of motion was 22 degrees extension [95% CI (-1.47, 45.47)], 114 degrees flexion [95% CI (89.4, 138.6)], and 92 degrees arc of motion [95% CI (58.68, 125.38)]. Treatment of select transcondylar distal humeral fractures with column screws in geriatric patients provides an option for stable fixation that allows early range of motion with minimal surgical morbidity.

The use of parallel pre-contoured plates in the treatment of A and C fractures of the distal humerus

The purpose of this study was to retrospectively evaluate the clinical and radiological results of fixation with parallel pre-contoured plates in intra-articular and extra-articular distal humerus fractures. We retrospectively evaluate seven cases of type A and six cases of type C fracture treated with the Mayo Clinic Congruent Elbow Plate system (Acumed, Hillsboro, Oregon) after a mean follow-up of 14.8 and 21.3 months, respectively. Mayo Elbow Performance Score (MEPS) was utilized for functional evaluation. Mean MEPS was (92.86 +/- 16.8) in the first group showing 6 excellent and one poor result, while (94.17 +/- 12) showing five excellent and one fair in the second group, showing no significant difference between the two groups (P = 0.87). The mean active motion recovered postoperatively was 120 degrees (+/-34.5 degrees) in type A fractures and 113 degrees (+/-14.7 degrees) in type C fractures, and there was no significant difference (P = 0.67). Complications occurred in 6 of the 13 patients analysed at follow-up (3 radial neuropathy, one ulnar neuropathy, one screw mobilization and one heterotopic ossification). The fractures healed in every patient, and no synthesis failed. The parallel plate system has proved to be extremely useful in the treatment of intra-articular and extra-articular distal humerus fractures. The pre-contoured geometry allows easier reduction and stabilization of complex fractures. The higher stability achieved permits early mobilization, thus obtaining a higher percentage of excellent results.

A clinical comparison of two different double plating methods for intraarticular distal humerus fractures

BACKGROUND

This study compared clinical outcomes in patients with intraarticular distal humerus fractures treated using 2 different double plating methods.

METHOD

Seventeen patients were treated by perpendicular plating (group I) and 18 by parallel plating (group II) methods. Arc of flexion averaged 106 degrees +/-23 degrees in group I and 112 degrees +/-19 degrees in group II.

RESULTS

Eleven patients in group I recovered full arc of flexion and 13 patients in group II achieved full arc of flexion. All patients obtained bone union, except 2 patients in group I. Nonunion in these patients developed in the supracondylar area. Complications developed in 6 patients in group I and in 8 in group II. No significant differences were found between the clinical outcomes of the 2o plating methods.

CONCLUSION

Although more patients failed to achieve bony union in the perpendicular plating group, both parallel and orthogonal plates positioning can provide adequate stability and anatomic reconstruction of the distal humerus fractures.

LEVEL OF EVIDENCE

2.

Locking reconstruction double plating of distal humeral fractures: how many screws in the distal ulnar column segment in A3 fracture provide superior stability? A comparative biomechanical in vitro study

OBJECTIVES

Two 90-degree configurations of locking reconstruction plates with different numbers of screws in the distal ulnar column segment of distal extra-articular humeral fractures with metaphyseal comminution (A3) were biomechanically investigated.

METHODS

Eight pairs of fresh-frozen human humeri were used. For paired comparison, the humeri were divided into 2 randomized groups. In both groups, double-plate osteosyntheses with locking reconstruction plates were performed in 90-degree configurations. In group 1, the posteriorly placed radial column plate exceeded the capitellum and the ulnar column plate extended into the ulnar sulcus. The ulnar plate was molded around the medial epicondyle and fixed with 3 short angular stable screws distally. In group 2, the posteriorly placed radial column plate was applied analogous to group 1. The locking reconstruction plate placed on the ulnar column was used reaching to the ulnar epicondyle, fixed with 1 long, angular, stable screw in the distal fragment. Stiffness testing for axial load and bending in static and cyclic tests were performed. In static test mode, a load was applied with a frequency of 0.1 Hz. For cyclic loading conditions, a load was applied at 1 Hz for 5000 cycles.

RESULTS

All tested specimens adequately resisted simulated physiologic loading conditions with no failure. Comparable stiffness values for axial load (P = 0.161) and significant lower stiffness values for bending (P = 0.017) in group 2 under static bending conditions were found. Considering cyclic loading conditions, no significant alterations in stiffness in each group under axial load occurred. In bending conditions, stiffness values for group 2 were significantly lower than that for group 1 (P = 0.036).

CONCLUSIONS

Under static and cyclic bending conditions, stiffness in group 2 was significantly lower than that in group 1. Nevertheless, both implant configurations showed no failure of the constructs. Based on these data, when applying locked plates in the clinical setting, more than 1 locked screw applied into the distal ulnar column of the articular segment is recommended.

Double-column fixation for type C fractures of the distal humerus in the elderly

BACKGROUND

Although several studies reported good results of open reduction and internal fixation of displaced fracture of the adult distal humerus, few studies have specifically addressed the results of such surgical fixation in osteoporotic bone in the elderly.

METHODS

This study focused on AO type C fractures in the elderly by using 2 plates for fixation of the lateral and medial columns to reconstruct a stable triangular frame of the distal humerus. The study comprised 35 patients, and 32 were available for final evaluation at a mean follow-up of 24.5 months (range, 14-60 months).

RESULTS

Mayo Elbow Function Score showed 25 patients (78%) achieved an excellent functional result, and 7 (22%) had a good result. No patients were considered to have a fair or poor result. At the final follow-up, the mean range of flexion to extension of the elbow was 22 degrees (range, 10 degrees -40 degrees) to 125 degrees (range, 100 degrees -140 degrees). All fractures united at average of 3.5 months (range, 2.5-5.3 months).

CONCLUSION

Open reduction and internal fixation using double-columned plating is a useful and effective technique in the management of displaced, comminuted, intra-articular fractures of the distal humerus in elderly patients.

LEVEL OF EVIDENCE

Level 4; Case series, treatment study.