Coronoid fractures of the elbow

Coronoid fractures and complex elbow instability: current concepts

Fractures of the coronoid process typically occur as part of more complex injury patterns, such as terrible triads, trans-olecranon fracture-dislocations, posteromedial rotatory injuries or Monteggia-like lesions. Each pattern is associated with a specific type of coronoid fracture with regard to shape and size and specific soft-tissue lesions. O' Driscoll classification incorporates those associations identifying three major types of fractures: tip, anteromedial facet, and basal fractures. The objective of this study is to review the most common types of complex elbow instability, identify the indications for coronoid fixation and guide the appropriate management. Tip fractures as those seen in terrible triads can conditionally left untreated provided that elbow stability has been restored after radial head fixation and ligaments repair. Anteromedial facet fractures benefit from a buttress plate, while large basilar fractures can be effectively secured with posteroanterior screws. Coronoid reconstruction with a graft should be considered in post-traumatic cases of chronic coronoid deficiency.

Biomechanical evaluation of the modified lasso technique

BACKGROUND

The Terrible Triad of the elbow is a constellation of elbow dislocation, radial head fracture and coronoid process fracture. A common type of coronoid fracture documented with this triad is type II Regan-Morrey coronoid fractures. The preferred fixation method for this fracture type is the lasso technique, medial-lateral tunnel orientation being the traditional approach. Considering elbow anatomy, we saw an opportunity to potentially improve fixation by altering the suture lasso tunnel orientation to a proximal-distal orientation.

HYPOTHESIS

Two tunnels in the proximal-distal direction would result in greater biomechanical stability as compared to the traditional lasso technique.

MATERIAL AND METHODS

A type 2 Regan-Morrey fracture was created in 12 fresh frozen cadaveric elbows at 50% of the coronoid height using an oscillating saw. The humero-ulnar joint was placed in 0 degrees flexion then loaded at a rate of 10mm/min to failure.

RESULTS

The control technique (medio-lateral tunnels) showed failure load of 150±81N that was not significantly different (p=0.825) than the 134±116N measured for the modified technique (distal-proximal tunnels). The portion of the load-displacement curve used to calculate stiffness was linear (R^2=0.94±0.04) with determination coefficients that did not differ between the two groups (p=0.351). For stiffness, we measured 17±13N/mm and 14±12N/mm respectively for control and modified techniques that did not result in a significant difference (p=0.674).

CONCLUSION

In this attempt to improve the shortcomings of the lasso technique, we found that changing from medio-lateral to proximal-distal drilling directions did not result in an appreciable biomechanical benefit.

LEVEL OF EVIDENCE

Basic science study; Biomechanics.

Coronoid Fragment Size in Monteggia Fractures Predicts Ultimate Function

We sought to determine what effect the size of a displaced coronoid fracture fragment in Monteggia injuries has on clinical outcome. Sixty-seven patients presented to an academic medical center for operative fixation of a Monteggia fracture. Radiographs were assessed for length and height of the displaced coronoid fragment using measuring tools in our center's imaging archive system. Data were analyzed using binary logistic or linear regression, as appropriate, controlling for sex, age, and Charlson Comorbidity Index. Outcome measurements included radiographic healing, range of motion, postoperative complications, and reoperation. The cohort had a mean follow-up of 16.7 months. Mean coronoid fragment area was 362.4±155.9 mm2. Elbow range of motion decreased by 3.8° of elbow flexion (P<.001), 3.3° of elbow extension (P<.001), and 3.8° of forearm supination (P=.007) for every 1-cm2 increase in coronoid fragment area. Complications (P=.012) and reoperation (P=.036) were associated with increasing coronoid fragment area. Nonunion rate, nerve injury, and pronation range of motion were not correlated to increasing coronoid fracture fragment area (P=.777, P=.123, and P=.351, respectively). As displaced coronoid fragment size increases in Monteggia fracture patterns, elbow range of motion decreases linearly. Coronoid displacement was also associated with increased rates of postoperative complication and need for reoperation. [Orthopedics. 2024;47(1):15-21.].

Elbow dislocation approach for complex elbow fractures: a cadaveric study

BACKGROUND

Approach need to be considered when surgeons dealt with complex elbow injuries and the choice of the approach is a challenge for surgeons due to the complex anatomy. On the basis of releasing the lateral collateral ligament, we modified the dislocation technique to pursue the superior exposure including not only the distal humeral surface but also the anterior facet of the coronoid process.

METHODS

A total of 4 cadaver specimens and 8 elbows were included in the study. Each cadaver provided one elbow for either the elbow dislocation approach or the posterior olecranon approach. The exposed distal articular surface of humerus, humeral capitulum, humeral trochlea, anterior trochlea of distal humerus, posterior trochlea of distal humerus and the ulnar coronoid process surface were marked by image J software and calculated for a comparison for each surgical approach.

RESULTS

The total distal humeral surface was exposed as a median of 98.2 (97.6, 99.6)% and 62.0 (58.3, 64.5)% for the elbow dislocation approach and the olecranon osteotomy approach (P < 0.001), the capitulum 100% and 32.4 (28.0, 39.2)% (P < 0.001), the trochlea 93.2(90.1, 96.9)% and 72.5 (65.2, 78.8)% (P < 0.001), the anterior trochlear articular surface 96.0(93.0, 97.4)% and 50.3 (43.6, 59.1)% (P < 0.001), the posterior trochlear articular surface 95.4 (93, 100)% and 100% (P = 0.76) and the articular surface of the coronoid process of ulna 71.3 (66.0, 74.2)% and 0% (P < 0.001).

CONCLUSION

For complex elbow fractures, the technique of elbow dislocation provides complete exposure of the distal humerus surface and a significant portion of the coronoid process surface, facilitating direct visualization for reduction and fixation. Level of evidence Anatomy Study; Cadaver Dissection.

Traumatic Irreducible Pediatric Radial Head Dislocations: A Unique Case and Review of the Literature

Background

Irreducible radial head dislocations are uncommon injuries and blocks to reduction typically result from interposed soft tissue. We report the case of a pediatric patient who sustained an irreducible radial head dislocation with a concomitant posterior elbow dislocation and coronoid process fracture. To the author's knowledge, irreducible radial head dislocations presenting as part of a terrible triad like constellation of injuries have not been previously reported. A case-based review of the literature was also performed.

Case Description

A 7-year-old male presents to our pediatric hospital as a transfer from an outside hospital after sustaining a posterolateral radial head and posterior elbow dislocation secondary to a fall. CT imaging and 3D reconstruction revealed a Type 1 coronoid process fracture. At our institution, closed attempts at reduction in the operating room under fluoroscopy with general anesthesia were also unsuccessful. Open reduction of the radial head and repair of the soft tissue structures was ultimately required to stabilize the patient's elbow injury.

Conclusion

Irreducible pediatric radial head dislocations are rare and inherently unstable injuries. To the authors' knowledge, there are no prior reports of irreducible radial head dislocations that present in a terrible triad like fashion with a coronoid process fracture and posterior elbow dislocation. In the present report, successful treatment of this injury required open reduction and soft tissue repair. Level of Evidence: IV.

Surgical Treatment of Adams Type IV Anterolateral Fracture of the Ulna Coronoid Process

OBJECTIVE

Anterolateral coronal fractures are so rare that the mechanism of injury, the type of combined fracture and ligament injury, and the optimal treatment are unknown. To study the outcome of surgical treatments for anterolateral (AL) fracture of the ulna coronoid process (Adams Type IV) and summarize the characteristics of this type of fracture and to guide clinical applications.

METHODS

From February 2015 to April 2021, 32 patients were included in the study. All patients had standard radiography with anteroposterior and lateral views, computed tomography, and intraoperative fluoroscopy. All patients were treated surgically. Surgery-related information, including surgical approach, operation duration, blood loss, and repairing the lateral collateral ligament and the medial collateral ligament integrity, were recorded. The patient's clinical details, such as the final range of motion (ROM), the Broberg-Morrey scores and the visual analogue scale (VAS) at the last follow-up, were described. The chi-square test or Fisher's exact test was used for statistical analysis.

RESULTS

We divided patients into two groups according to the anterolateral coronoid fracture morphology. In the intact group, 20 patients with an intact anterolateral coronoid fracture fragment. In the comminuted group, 12 patients with comminuted anterolateral coronoid fracture fragments extended the less sigmoid notch of the ulna. There was no difference in age, sex, total incision length, follow-up duration, and recovery with rehabilitation among the two groups (all Ps >0.05). The other follow-up outcomes, such as elbow ROM (Flexion, Extension, Posterior rotation, Anterior rotation), VAS score, or Broberg-Morrey scores, were not different between the two groups (all Ps >0.05). Both groups achieved relatively satisfactory clinical outcomes, and the Broberg-Morrey score and index excellence rate reached 84.38%. There is a statistical difference in the history of elbow dislocation (P = 0.017), radial head fracture type (P = 0.041), operation duration (P = 0.014) and blood loss at operation (P = 0.029) between the two groups. Cannulated screws, anchors, and sutures were used as point fixation in the coronoid process of the ulna. There was a statistical difference between the two groups in the choice of internal fixation (P = 0.020).

CONCLUSIONS

For anterolateral ulnar coronoid fractures with different degrees of comminution, effective and reliable surgical treatment can achieve better results and fewer complications.

[Elbow joint dislocation : Frequent concomitant injuries and current treatment concepts]

Dislocations of the elbow joint are among the most prevalent dislocation injuries in the human body after shoulder joint dislocations and represent a challenge in the clinical routine because of the concomitant injuries and complications. They predominantly affect young adults who become injured during athletic or daily activities. A distinction is generally made between a simple elbow dislocation and a dislocation fracture of the elbow; however, a uniform classification or treatment algorithm has not yet been established, especially for simple elbow dislocations with associated ligamentous, muscular and capsular concomitant injuries. Due to this and the complexity of this injury, a standardized approach is needed to initiate the optimal treatment at an early stage and to correctly select the narrow treatment pathway between impending chronic instability and elbow stiffness.

Musculoskeletal Computed Tomography: How to Add Value When Reporting Adult Upper Limb Trauma

ABSTRACT

There is increasing reliance on computed tomography to evaluate fractures and dislocations following routine evaluation with plain radiography, critical in preoperative planning; computed tomography can provide multiplanar reformats and 3-dimensional volume-rendered imaging, providing a better global assessment for the orthopedic surgeon. The radiologist plays a critical role in appropriately reformatting the raw axial images to illustrate best the findings that will help determine further management. In addition, the radiologist must succinctly report the pertinent findings that will have the most significant bearing on treatment, assisting the surgeon in deciding between nonoperative and operative management. The radiologist should also carefully review imaging to look for ancillary findings in the setting of trauma beyond the bones and joints, including the lungs and rib cage when visualized.In this review article, we will systematically describe key features for fractures of the scapula, proximal humerus, distal humerus, radial head and neck, olecranon, coronoid process through a case-based approach, and distal radius. Although there are numerous detailed classification systems for each of these fractures, we aim to focus on the core descriptors that underpin these classification systems. The goal is to provide the radiologist with a checklist of critical structures they must assess and findings that they should mention in their report, emphasizing those descriptors that influence patient management.

The Novel Hooked Kirschner Wire Technique for Ulna Coronoid Process Fractures

Background

The aim of this study was to introduce a novel technique to improve the ease of fixing of even small fragments of the coronoid process and report the clinical outcomes of this method.

Methods

Forty-nine patients with ulnar coronoid process fractures fixed using the hooked Kirschner wire (K-wire) technique at our hospital from 2007 to 2019 were reviewed. Radiological features and fracture union were assessed using simple radiographs. Functional outcomes of the treated elbows were evaluated at the final follow-up visit using the Mayo Elbow Performance Score (MEPS).

Results

All patients were examined at a mean follow-up of 17.7 months (range, 6-62 months). We observed bony union in patients at a mean of 10.9 weeks (range, 6-22 weeks). The mean flexion and extension ranges of the elbow were 132.0° (range, 106° -151°) and 4.5° (range, -20° to 30°), respectively. The mean pronation and supination ranges of the forearm were 81.1° (range, 60°-90°) and 88.3° (range, 60°-120°), respectively. The mean arc of the elbow was 127.4° (range, 78°-160°). All patients were evaluated using the MEPS at the final follow-up visit, with a mean score of 96.9 points (range, 80-100 points). One case of coronoid nonunion was observed and re-fixation was performed. One case of infection was observed and also treated with additional surgery. Three patients complained of ulnar nerve symptoms and 1 patient underwent surgical release for tardy ulnar nerve palsy.

Conclusions

Despite its limitations, the hooked K-wire technique was a useful method for even smaller coronoid process fractures. K-wires were also a useful temporary intraoperative fixation method and could provide permanent fixation.

Optimal K-Wire Placement for Indirect Cannulated Screw Fixation of Coronoid Process Fractures: A Radiology-Based Guide

PURPOSE

Indirect fixation of coronoid process fractures of the ulna, especially arthroscopically, offers the possibility to avoid extensive medial surgical approaches. However, optimal placement of K-wires for cannulated screw fixation is technically challenging. The aim of the present study was to present guide values for K-wire placement for indirect screw fixation of coronoid tip (COT) and anteromedial facet (AMF) fractures of the ulna.

METHODS

Computed tomography scans of the elbows of 197 patients with an uninjured ulna were identified and evaluated following a standard measuring protocol. Optimal placement of K-wires was defined as the bisector between the anterior and articular cortex while respecting a 1.6-mm safe zone for each placement. This placement of the K-wires in the COT and the AMF was analyzed by measuring the wire angulation in relation to the posterior ulnar cortex (AUC), the distance from the entry point to the posterior olecranon edge (DPE), and the intraosseous length (IOL). Because the coronoid has a curved shape, measurements of the COT and AMF were expected to differ significantly. Sex was also expected to influence measurements. To determine whether this optimal placement of K-wires can be reliably identified, interobserver and intraobserver reliabilities were evaluated.

RESULTS

To address tip fragments, we determined a mean AUC of 64°, DPE of 36 mm, and IOL of 38 mm. Regarding wire placement toward the AMF, the means for the AUC, DPE, and IOL were 79°, 27 mm, and 33 mm, respectively. Statistically significant differences were found between the COT and the AMF for the AUC, DPE, and IOL. Our measuring protocol showed good interobserver and intraobserver reliability.

CONCLUSIONS

K-wire placement toward the COT demands a smaller angle, a longer IOL, and a more distal entry point than wires placed toward AMF. These differences reflect the curved and complex anatomy of the coronoid.

CLINICAL RELEVANCE

This measuring algorithm can be used to plan osteosynthesis, and the obtained reference values can help understand the coronoid's complex anatomy.

A Novel Suture-Preset Spring Plate System (SSPS) for Comminuted Coronoid Process Fracture in the Elbow

OBJECTIVE

This study is aimed to investigate the clinical outcomes of a novel SSPS for fixation of the comminuted coronoid fracture.

METHODS

A retrospective study was carried out in the patients with comminuted fractures of the coronoid treated by SPSS fixation between January 2014 and December 2018. A total of 17 patients (17 sides) was included in our study, including 11 male and six female, with a mean age range from 18 to 60. All cases started to functional rehabilitation immediately after the operation. Clinical outcomes were evaluated both radiographically and functionally at the follow-up visit, including the elbow instability, range of motion and Mayo elbow performance score (MEPS).

RESULTS

According to the O'Driscoll classification system, there was two side of type 1.2, two of type 2.1, four of type 2.2, three of type 2.3, two of 3.1 and four of type 3.2. The surgery was carried out by Kocher and anteromedial approach in 12 patients, posterior and anteromedial approach in four, anterior approach in one. The average operation time and intraoperative blood loss was 129.41±43.87 min and 115.29±104.65 ml. The median follow-up time was 9 months (range, 6 to 15 months). The mean flexion, extension, pronation and supination motion was 138.76±8.67 degrees, 20.00±13.58, 82.94±5.32and 74.12±14.39 respectively at final follow up. The mean MEPS score was 89.76±8.46, including 11 excellent, 3 good and 3 fair result. The mean VAS score was 1.94±0.97. The mean union time of coronoid fractures was 2.77±0.31 months according to the established standard of healing. There were no significant differences in clinical outcomes among groups according to the O'Driscoll classification (P > .05) and ligament repair strategy (P > .05). No patient underwent instability or dislocation of the elbow during follow up. There were two cases with mild ulnar nerve symptoms which recovered totally at follow up. Meanwhile, there were three cases with heterotopic ossification of the elbow.

CONCLUSION

Our findings demonstrated that the SSPS can provide a reliable fixation for the comminuted coronoid fracture with satisfactory clinical outcomes.

The coronoid opening angle: a novel radiographic technique to assess bone loss in coronoid trauma

BACKGROUND

Elbow fracture dislocations are complex injuries that often require surgical treatment in order to obtain a stable and congruent elbow joint. The coronoid plays a key role in the stability of this joint. Accurately identifying the degree of coronoid bone loss in the setting of traumatic elbow injuries is challenging. The purpose of this study is to describe a new radiographic measure, the coronoid opening angle (COA), to assist in estimating bone loss in these challenging fractures.

METHODS

Radiographs were drawn from a regional database in a consecutive fashion. Candidate radiographs were excluded on the basis of radiographic evidence of degenerative changes, previous surgery or injury, bony deformity, and inadequate lateral view of the elbow. Normal COA, coronoid height, and calculated COA at varying amounts of bone loss were determined by 3 reviewers.

RESULTS

A total of 120 subjects were included. The normal coronoid opening angle was 34° (95% CI 32.9°-34.0°) and the coronoid height, 18.8 mm (18.1-19.6). Ninety-five percent of the population had an opening angle greater than 29° (95% CI 27.2°-29°). The COA limit was calculated at 20%, 33%, and 50% of baseline coronoid height corresponding to degree of bone loss. Coronoid opening angles of 24°, 20°, and 16°, respectively, indicate the minimum bone loss of interest in 95% of the population. The intraclass correlation coefficient was found to be 0.89 or higher.

CONCLUSION

In the setting of elbow trauma, it is often challenging to predict the amount of coronoid bone loss. The coronoid opening angle is a new technique and an adjunct for lateral elbow radiographs to predict the minimum coronoid bone loss. This can be used to guide clinical decision making, aid in predicting instability, and guide treatment. Future research will aim to validate this tool in the clinical trauma setting.

Histologic Evaluation of the Triceps Brachii Tendon Insertion: Implications for Triceps-Sparing Surgery

PURPOSE

Triceps detachment and olecranon osteotomy are 2 techniques used to enhance exposure in elbow surgery. Both the techniques can potentially add considerable morbidity and lengthen the recovery after surgery. Triceps-sparing surgery can potentially mitigate those issues. The purpose of this study was to evaluate the triceps tendon insertion at a histologic level to help improve triceps-sparing surgical techniques used in elbow trauma and arthroplasty.

METHODS

Seventeen fresh-frozen cadaveric elbow specimens were collected. The olecranon and its soft tissue attachments were isolated. We performed gross measurements and sectioned the specimens for histologic evaluation in the saggital or coronal planes. The proximal-to-distal and medial-to-lateral dimensions of the tendon and the distance from the proximal tip of the olecranon to the proximal tendon insertion were measured microscopically on stained embedded sections.

RESULTS

The proximal-to-distal dimension of the triceps tendon insertion was less than previously reported, whereas the medial-to-lateral dimension was similar. The true distance from the tip of the olecranon to the proximal tendon insertion was greater than the previously reported distance obtained via gross measurement.

CONCLUSIONS

Gross measurement of the triceps tendon insertion overestimates and inaccurately represents the true insertional footprint. Gross measurement has been shown to demonstrate consistent disparity compared with histologic measurement. Histologic investigation provides a more accurate description.

CLINICAL RELEVANCE

The finding that the distance from the articular tip of the olecranon to the proximal tendon insertion is greater than previously reported may have clinical implications. A triceps split approach may allow more visualization and exposure of the posterior joint and, therefore, lessen the need for triceps detachment or olecranon osteotomy.

Radiographic Evaluation of Elbow Fractures

Fractures and dislocations of the elbow are a common cause of emergency department visits each year. Radiography remains the bedrock of an initial injury assessment, and recognition of distinctive injury patterns based on fracture location, morphology, and severity, guides optimal clinical decision-making. This article reviews basic elbow anatomy, frequently seen fractures and injury patterns, and highlights how these findings influence surgical planning and patient management.

Morphological characteristics of fractures of the anteromedial facet of the coronoid in posteromedial rotatory instability of the elbow: a three-dimensional CT remodeling study

BACKGROUND

Fractures of the anteromedial facet of the coronoid in posteromedial rotatory instability of the elbow are classified into 3 subtypes based on their location. The purpose of this study was to analyze the fracture morphology of anteromedial facet fractures in their 3 subtypes (anteromedial rim, anteromedial rim + tip, and anteromedial rim + sublime tubercle [±tip]).

METHODS

Three-dimensional computed tomography remodeling was used to evaluate anteromedial facet fractures in a consecutive series of 40 patients, all of whom were affected by posteromedial rotatory instability of the elbow. Characteristics of the fractures, including the number of fragments, size of fragments, plane of the fracture line, and involvement of the sublime tubercle and radial notch, were measured for each subtype of the anteromedial facet fractures.

RESULTS

Each subtype had a typical fracture pattern and distinct size. The fracture subtype 1 showed a single-fragment fracture, subtype 2 showed either a single- or dual-fragment fracture, and subtype 3 showed either a dual- or triple-fragment fracture. The angle between the fracture line and the coronal plane was greatest in subtype 3 fractures. The surface area of the fragment was largest in subtype 3 fractures. The percentages of articular involvement of the sublime tubercle were 0% in subtype 1, 47% in subtype 2, and 79% in subtype 3. The percentages of articular involvement of the radial notch were 0% in subtype 1, 7% in subtype 2, and 8% in subtype 3.

CONCLUSION

Analysis with quantitative 3-dimensional computed tomography showed the characteristic morphology of each subtype of anteromedial facet fracture. Subtype 1 comprised 1 fragment with the smallest fragment size. Subtype 2 was a single- or dual-fragment fracture, the size of which should be considered in the treatment plan. Subtype 3 was a large fragment comprising the sublime tubercle. Our findings are significant because they highlight unique fracture morphology that may help surgeons to distinguish one fracture subtype from another in clinical practice.

Reconstruction of coronoid process of the ulna: a literature review

As a pivotal part of the elbow joint structure, the coronoid process of the ulna plays a vital role in maintaining elbow joint stability. Loss of coronoid process height causes instability of the elbow joint depending on the fracture characteristics and size. The diagnosis and treatment of coronoid process fractures has gained widespread attention from orthopedic surgeons. Nevertheless, few reports have described reconstruction of coronoid process fractures and defects that affect elbow joint stability. Treatment of elbow joint instability induced by coronoid process defects is challenging because most cases are complicated by other elbow joint injuries. Moreover, the clinical efficacy remains unclear. The present narrative review was performed to examine the research progress on reconstruction of the coronoid process. The findings of this review provide evidence for clinical repair and reconstruction of coronoid process defects and contribute to the published literature on this topic.

Functional Outcome of Surgically Treated Isolated Coronoid Fractures With Elbow Dislocation in Young and Active Patients

Coronoid fractures are less frequent injuries seen in around one-tenth of patients with elbow dislocation. Any injury to the coronoid process can be associated with elbow instability, in which injury to collateral ligaments co-exists, resulting in a loss of congruency of the elbow joint. However, there is a scarcity of evidence regarding patients' management with elbow dislocation and associated coronoid fractures. So, our aim is to assess the functional outcome of the elbow after operative fixation in patients with any type of coronoid fracture with associated elbow dislocation. A total of six patients with closed coronoid fracture of the elbow, with associated elbow dislocation, without any other associated trauma or previous surgery to the same limb, were included in our study. After closed reduction, patients with an incongruent reduction of the elbow joint were operated. The injured structures were repaired in an inside-out sequence: the coronoid fragment was first reduced by using a lasso-type suture. The larger fragments of the coronoid were fixed with either a screw or a plate when deemed necessary. Then, the lateral collateral ligament was repaired either using a suture anchor or transosseous (No. 2 Arthrex; Naples, Florida) sutures.

After repair, the elbow was examined for stability radiologically using the hanging arm test; a concentric reduction of the elbow in lateral view during this test indicates a stable elbow. All patients showed a good to excellent outcome on the Mayo elbow performance score (MEPS) at the final follow-up (three patients had an excellent score while three had a good score). At the final follow-up, mean elbow flexion was 124º, loss of extension was 10º in only one patient, mean supination was 80º, and mean pronation was 72º. Isolated fractures of the coronoid associated with elbow dislocation require appropriate evaluation and management. Closed reduction and immobilization alone in young and active patients may not be sufficient, especially in patients with incongruent ulnohumeral joint. Surgical fixation of the coronoid fragment and repair of the collateral ligament, whenever indicated, can provide good functional outcomes.

Arthroscopic-assisted Fixation of a Nonunited Coronoid Stress Fracture in a Competitive Gymnast: A Case Report

CASE

Gymnasts may suffer elbow injuries due to repetitive loading. However, coronoid stress fractures remain uncommon. We report a case of a high-level female competitive gymnast with a nondisplaced coronoid stress fracture that failed to heal with conservative management. Arthroscopic-assisted in situ fixation of the coronoid nonunion was performed, and the gymnast returned to competition after the fracture healed.

CONCLUSION

Coronoid stress fractures should be considered in gymnasts presenting with chronic elbow pain. If nonoperative treatment is unsuccessful, arthroscopic fixation can be successful in stimulating healing of the nonunion without the morbidity of an open approach or bone grafting.

Functional outcomes after treatments for different types of isolated ulnar coronoid fracture: A protocol for systematic review

BACKGROUND

Optimal treatments for ulnar coronoid fracture have yet to be determined. We aimed to systematically review treatment efficacy assessed by functional outcomes of patients with isolated ulnar coronoid fracture.

METHODS

Medline, Cochrane Library, EMBASE, and Google Scholar were searched for studies reporting quantitative outcomes data after surgical treatment for isolated ulnar coronoid fractures up to July 16, 2019. Functional outcomes determined using disabilities of the arm, shoulder and hand score; Mayo elbow performance score (MEPS); and range of motion were systematically reviewed.

RESULTS

Six studies with a total of 65 patients with isolated coronoid fracture who had received surgical treatment were included. All studies were of good quality according to a modified Delphi checklist. Most patients had Type II fractures based on Regan-Morrey or O'Driscoll classification. Disabilities of the arm, shoulder and hand scores were reported by 2 studies (mean range 5-17). Four studies reported MEPS (mean range 89-98). One study reported Broberg-Morrey scores, in which 93% patients achieved excellent or good outcomes. Five studies reported range of motion, with mean flexion ranging from 122 to 137 and mean extension ranging from 4.0 to 21 degrees. Quantitative analyses revealed that lateral, medial, or posterior approaches in treating Type II fractures are associated with higher postoperative MEPS and flexion scores than the anteromedial approach.

CONCLUSIONS

Treatment efficacy assessed by functional outcomes for isolated ulnar coronoid fractures is overall satisfactory. Whether lateral, medial, or posterior approaches lead to more favorable outcomes than the anteromedial approach is inconclusive. Further prospective studies are warranted.

Buttress plate fixation of coronoid process fractures via a medial approach

PURPOSE

To assess the clinical and radiographic outcomes of coronoid process fractures surgically managed with buttress plate fixation via a medial approach.

METHODS

A retrospective review of all coronoid fractures surgically fixed in our institution using a buttress plate technique via a medial approach between June 2012 and April 2015 by the senior author was performed. These fractures were all sizeable fractures contributing to persistent elbow instability in terrible triad or varus posteromedial rotatory instability injury patterns. A prospective telephone questionnaire was conducted to assess patient outcomes using the disabilities of the arm, shoulder and hand (DASH) score and Mayo hlbow performance score (MEPS).

RESULTS

Twelve patients were included in the study, comprising 10 males and 2 females with an average age of 39 years (range, 19-72 years). Mean follow-up was 16 months (range, 4-18 months). The average time to radiographic union was 4 months (range, 3-7 months). Range of motion measurements at final follow-up were obtained in 11 out of 12 patients, with one patient defaulting follow-up. All 11 patients displayed a functional elbow range of motion of at least 30°-130°, with an average arc of motion of 130° (range, 110° -140°), mean elbow flexion of 134° (range, 110° -140°) and mean flexion contracture of 3° (range, 0° -20°). The mean DASH score was 16 (range, 2.5-43.8) and the mean MEPS was 75 (range, 65-100). Complications observed included one patient with a superficial wound infection which resolved with a course of oral antibiotics and one patient with radiographic evidence of heterotopic ossification which was conservatively managed. No residual elbow instability was observed and no reoperations were performed.

CONCLUSION

Buttress plate fixation via a medial approach of coronoid process fractures that contribute to persistent elbow instability represents a reliable method of treatment that produces satisfactory and predictable outcomes.

Biomechanical Role and Motion Contribution of Ligaments and Bony Constraints in the Elbow Stability: A Preliminary Study

In flexion–extension motion, the interaction of several ligaments and bones characterizes the elbow joint stability. The aim of this preliminary study was to quantify the relative motion of the ulna with respect to the humerus in two human upper limbs specimens and to investigate the constraints role for maintaining the elbow joint stability in different section conditions. Two clusters of four markers were fixed respectively to the ulna and humerus, and their trajectory was recorded by a motion capture system during functional orthopedic maneuver. Considering the posterior bundle of medial collateral complex (pMUCL) and the coronoid, two section sequences were executed. The orthopedic maneuver of compression, pronation and varus force was repeated at 30°, 60° and 90° flexion for the functional investigation of constraints. Ulna deflection was compared to a baseline elbow flexion condition. With respect to the intact elbow, the coronoid osteotomy influences the elbow stability at 90° (deflection = 11.49 ± 17.39 mm), while small differences occur at 30° and 60°, due to ligaments constraint. The contemporary pMUCL section and coronoid osteotomy causes elbow instability, with large deflection at 30° (deflection = 34.40 ± 9.10 mm), 60° (deflection = 45.41 ± 18.47 mm) and 90° (deflection = 52.16 ± 21.92 mm). Surgeons may consider the pMUCL reconstruction in case of unfixable coronoid fracture.

Efficacy of internal fixation with mini plate and internal fixation with hollow screw for Regan-Morrey type II and III ulna coronoid fractures

BACKGROUND

Ulna coronoid fracture is a complicated injury and occurred in the coronal plane. Undeniably, there is no universally accepted approach for treating ulna coronoid fractures. Therefore, this study aimed at exploring the efficacy of different surgical treatments for Regan-Morrey type II and III ulna coronoid fractures.

METHODS

A total of 164 patients with ulna coronoid fractures were admitted and treated in department of orthopedics at Yiwu Central Hospital, the Affiliated Yiwu Hospital of Wenzhou Medical University for retrospective analysis. The baseline features (age, gender, time from injury to surgery and so on) before the surgery and different conditions during the surgery were compared. Following that, the Visual Analogue Scale (VAS) pain score was employed to evaluate the severity of preoperative and postoperative pain experienced by the patients in each group. Afterwards, Broberg and Morrey elbow score was used to evaluate elbow joint function and surgical effect of the patients. Lastly, the postoperative recovery and complications were compared.

RESULTS

It was firstly observed that internal fixation with mini plate and hollow screw compelled to lower average operation time and blood loss than Kirschner wire and steel wire suture. Next, the severity of postoperative pain was lessened in comparison with preoperative pain. Afterwards, mini plate and hollow screw improved elbow joint function more notable than Kirschner wire and steel wire suture, and Kirschner wire and steel wire suture resulted in higher incidence of complications and worse postoperative recovery.

CONCLUSION

Collectively, this study clarified that for the treatment of Regan-Morrey type II and III ulna coronoid fractures, internal fixation with mini plate and hollow screw has an overall superior surgical effect than internal fixation with Kirschner wire and steel wire suture.

[Research progress of posteromedial rotatory instability of the elbow]

Objective

To summarize the research progress in posteromedial rotatory instability (PMRI) of the elbow joint.

Methods

The recent researches about the management of PMRI of the elbow joint from the aspects of pathological anatomy, biomechanics, diagnosis, and therapy were analyzed and summarized.

Results

The most important factors related to PMRI of the elbow joint are lateral collateral ligament complex (LCLC) lesion, posterior bundle of the medial collateral ligament complex (MCLC) lesion, and anteromedial coronoid fracture. Clinical physical examination include varus and valgus stress test of the elbow joint. X-ray examination, computed tomography, particularly three-dimensional reconstruction, are particularly useful to diagnose the fracture. Also MRI, arthroscopy, and dynamic ultrasound can assistantly evaluate the affiliated injury of the parenchyma. It is important to repair and reconstruct LCLC and MCLC and fix coronoid process fracture for recovering stability of the elbow joint. There are such ways to repair ligament injury as in situ repairation and functional reconstruction, which include direct suturation, borehole repairation, wire anchor repairation, and transplantation repairation etc. The methods for fixation of coronal fracture include screw fixation, plate fixation, unabsorbable suture fixation, and arthroscopy technology.

Conclusion

It is crucial that recovering the stability of the elbow joint and early functional exercise for the treatment of PMRI. Individual treatment is favorable to protect soft tissue, reduce surgical complications, and improve the functional recovery and the quality of life.

Lasso plate - An original implant for fixation of type I and II Regan-Morrey coronoid fractures

INTRODUCTION

Coronoid fractures are notoriously difficult to manage particularly when there is a small fragment. We report a retrospective analysis of our experience with consecutive type I and II Regan-Morrey coronoid fractures using a lasso plate.

HYPOTHESIS

Type I and II Regan-Morrey coronoid fractures can be effectively managed using a lasso plate.

METHODS

From October 2011 and December 2013, 25 patients (21 males and 4 females, mean age 40.0 years) with type I and II Regan-Morrey coronoid fractures were treated with the open reduction and internal fixation (ORIF) using the lasso plate. Postoperative measurements of the elbow range of motion were recorded. Elbow function was evaluated by the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

All patients were reexamined at a mean follow-up of 32.7 months (range: 24-49 months). The mean fractures healing time was 13.6 weeks (range: 6 to 18 weeks). The mean flexion range of the elbow was 121.8° (range: 90° to 135°) and the mean extension range of the elbow was 10.6° (range: 0° to 20°). The mean pronation of the forearm was 75.8° (range: 65° to 85°). The mean supination of the forearm was 80.4° (range: 70° to 90°). The mean DASH score was 10.2 (range: 0 to 28). The mean MEPS was 83.4 (range: 55 to 95), 8 patients (32%) were rated excellent, 14 patients (56%) were rated good, 2 (8%) patients were rated fair. One (4%) patient was rated poor. No patient was seriously infected but implant breakage was found in one case. Two cases of elbow heterotopic ossification (HO) were observed. Two cases of elbow medial instability were observed.

DISCUSSION

The type I and II Regan-Morrey coronoid fractures combined with the instability of the elbow should be operated. The lasso plate reduces the pressure between the wire and the insertion of capsule. A tight wire results in greater stability than ordinary suture fixation, thus enabling early functional exercise.

CONCLUSION

In the treatment of type I and II Regan-Morrey coronoid fractures, lasso plate can provide concentric fracture reduction of the elbow and stable fixation to allow for early rehabilitation. Good clinical outcomes can be anticipated.

LEVEL OF EVIDENCE

Level IV: retrospective study.

A figure-eight suture loop with Kirschner wires for fixation of anteromedial coronoid process fractures: A case series

•

Eleven cases with a fracture of the anterior or anteromedial facet of the coronoid process were treated by coronoid fixation using a figure-eight suture loop.

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All 11 fractures were united at final follow-up with no joint incongruity, dislocation, or subluxation of the injured elbow.

•

The figure-eight suture pattern technique is an easy and effective technique to fix anterior or anteromedial facet fractures of the coronoid process.

Purpose

Sufficient fixation of an anterior or anteromedial facet fracture of the coronoid process in fracture-dislocation of elbow is important to maintain joint stability. The purpose of this study was to report our experience with 11 patients who were managed with an original fixation technique using a “figure-eight” suture loop.

Methods

From February 2010 to March 2011, 11 cases with a fracture of the anterior or anteromedial facet of the coronoid process were treated by coronoid fixation using a figure-eight suture loop. For cases with comminuted fractures, to prevent a suture from sliding into the fracture line, a 3- or 4-hole phalanx plate was enclosed in the suture loop to compress multiple fragments. Accompanying injuries, such as a radial head fracture or olecranon fracture, were fixed with repair of lateral collateral ligament injuries.

Results

On final evaluations at an average of 18 months after injury, the mean elbow arc of motion was 125.5° and the mean forearm rotation arc of 124.1°. All fractures were united with an average postoperative score according to the Mayo Elbow Performance Index of 91 points. All patients achieved satisfactory scores (seven excellent, four good). All 11 fractures were united at final follow-up with no joint incongruity, dislocation, or subluxation of the injured elbow.

Conclusions

The figure-eight suture loop technique is an easy and effective technique to fix anterior or anteromedial facet fractures of the coronoid process.

Controversies in Fractures of the Proximal Ulna

The olecranon process, coronoid process, and greater sigmoid notch are important components of the complex proximal ulna. Along with providing bony stability to the ulnohumeral joint, the proximal ulna serves as the attachment site of many important muscles and ligaments that impart soft tissue stability to the elbow joint. Management of proximal ulnar fractures continues to evolve as advances in imaging and anatomic and biomechanical studies have led to improvements in available implants; however, controversies remain, as shown in the current relevant literature.

Arthroscopic fixation of coronoid process fractures through coronoid tunnelling and capsular plication

PURPOSE

the purpose of this study is to describe a new arthroscopic technique for reduction and fixation of coronoid process fractures (CPFs) and report clinical and functional results in 4 patients after a 24-month follow-up.

METHODS

four patients underwent arthroscopic reduction and fixation of isolated CPFs (acute or non-unions, type I or type II according to the Regan-Morrey classification) performed using a new technique based on coronoid tunnelling and capsular plication. The patients were evaluated 6, 12 and 24 months after surgery, using the Disability of the Arm, Shoulder and Hand scale (DASH), the Mayo Elbow Performance Index (MEPI), and a visual analog scale (VAS); elbow range of motion (ROM) and joint stability were also evaluated and the rate of complications was reported.

RESULTS

all 4 patients completed the follow-up. At 6, 12 and 24 months, respectively, they recorded mean DASH scores of 22, 14 and 7, mean MEPI scores of 74, 82 and 94, and mean VAS scores of 4, 2 and 1. The mean ROM increased in all directions (at 6, 12 and 24 months, respectively: flexion: 112°, 125°, 144°; extension: 3°, 5°, 6°; pronation: 76°, 84°, 91°; supination: 78°, 82°, 86°). No signs of instability were observed and no complications were reported.

CONCLUSIONS

the new all-arthroscopic coronoid tunnelling and capsular plication technique here proposed can restore elbow function, ROM and stability and allows anatomical reconstruction of the joint after type I or type II CPFs. If performed by an experienced arthroscopist, it is a valid alternative to open reduction and external fixation.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Endobutton Fixation Technique for Multifragmented Coronoid Fractures

Coronoid fractures commonly occur in a part of unstable elbow fractures. Stable coronoid fracture fixation is important for early elbow motion. It may be difficult to fix multifragmented coronoid process fractures with loose capsular attachment. Thus, we demonstrated the endobutton suspensory technique to fix the anterior coronoidal fragments due to its suspensory effect providing capsular attachment. This technique allows stable fixation to the small multifragmented coronoid fractures with early range of motion.

Management of Adult Elbow Fracture Dislocations

Elbow fracture dislocations are complicated injuries that are difficult to manage and fraught with complications. A complete series of radiographs is typically complemented with CT scan to evaluate the elbow and assist preoperative planning. Typically, operative intervention is necessary and a systematic approach to the elbow injuries should be chosen. This article addresses the coronoid and proceeds to the radial head, lateral soft tissues, and finally the medial ligaments if elbow instability persists. With a focused, systematic surgical approach, improved outcomes have been demonstrated and patients may recover full function and range of motion in the affected elbow.

Treatment of the coronoid process fractures with anteromedial approach: a case report

This study aimed to explore the clinical effect of the coronoid process fractures with anteromedial approach. 18 cases of coronoid process fractures treated with the anteromedial approach were enrolled. Causes of injury included traffic injuries in 3 cases and fall on the ground in 15 cases. There were 6 cases of type I, 10 cases of type II, and 2 cases of type III according to the O'Driscoll classification. The time from injury to operation was 2-10 days (mean, 3.9 days). Fractures were fixed by using mini-plate or screws. All cases were followed-up for 12-24 months (average 14.9 months). The bony union time was 8-14 weeks with an average of 10.6 weeks. The mean flexion at last follow-up was 122° (range, 90°-140°), the mean extension loss was 20° (range, 0°-50°), and the mean pronation was 67° (range, 22°-90°), while the mean supination was 61° (range, 30°-88°). Elbows were stable in the flexion-extension and varus-valgus in all cases. According to the MEPS elbow performance score, results were excellent in 14 cases, good in 3 cases and fair in 1 case. According to the Broberg and Morrey elbow performance score, results were excellent in 9 cases, good in 4 cases, and fair in 1 case. In conclusion, the anteromedial approach facilitates the reduction and fixation of the coronoid process fractures and has advantages of clear exposure, convenient placement of internal fixation, small invasion and good clinical results.

Use of fine-threaded K-wires in the treatment of coronoid fractures in complex elbow instability

The coronoid process is one of the main elbow constraints that provides ulnohumeral joint stability. Coronoid fractures may be fixed using multiple techniques, including transosseous sutures, screws, and plates. The goal of this study was to analyze the clinical and radiographic outcomes in a series of patients with complex elbow instability in whom coronoid fractures were repaired using fine-threaded K-wires. Eight men and 10 women (mean age, 47 years) were followed prospectively for a mean of 26 months. Surgical treatment consisted of open reduction and internal fixation of all fractures; radial head replacement in Mason III injuries; lateral collateral ligament repair in all patients; and, in cases of persistent instability, medial collateral ligament repair, hinged fixator application, or both. Coronoid fixation was performed using 2 or more fine-threaded K-wires, depending on the fragment size, inserted from the posterior aspect of the ulna and directed toward the coronoid fragment using a 1-step fixation technique. At last follow-up, mean extension was 15°, mean flexion was 133°, mean pronation was 78°, and mean supination was 69°; mean Disabilities of the Arm, Shoulder and Hand score was 9.7, mean American Shoulder and Elbow Surgeons score was 85, and mean Mayo Elbow Performance Score was 89. According to the Mayo Elbow Performance Index, 10 excellent, 7 good, and 1 fair result were recorded. All but 1 patient had a stable elbow. Fracture healing was observed in all but 1 patient. No secondary coronoid fragment dislocation or implant failures were reported. This study shows that using fine-threaded K-wires provides easy, minimally invasive, stable, and successful 1-step fixation that can be used to obtain osteosynthesis of coronoid fractures in patients with complex elbow instability.

Midterm Results of 58 Fractures of the Coronoid Process of the Ulna and their Concomitant Injuries

BACKGROUND

In general, fractures of the coronoid process are rare and usually occur in combination with additional elbow joint injuries. The treatment of these injuries aims to regain a stable as well as a flexible and loadable joint. Although there is currently little evidence, therapy recommendations remain controversial. Therefore, the aim of this study was to prognostically determine relevant factors for therapy recommendation by analysing a representative patient population of two trans-regional trauma centres.

MATERIAL AND METHODS

Seventy-seven patients with a fracture of the coronoid process were treated within an 8-year period (2001 to 2009). After an average of 48 months (SD 31), treatment outcome of 58 patients (75%) was acquired. The results were statistically analysed.

RESULTS

The average age of the patient was 51.8 years (SD 13.6); 36 were male and 34 had a fracture on the right arm. Applying the fracture types of the coronoid process in accordance with Regan/Morrey, the result was: Type I (19), II (17) and III (22). Further injuries were also detected: 40 radial head fractures, 17 proximal ulnar fractures and 2 fractures of the olecranon. A luxation was detected in 44 of the 58 patients (76%). The patients' average MEPS (Mayo Elbow Performance Score) was 80.6 points (SD 18), with significant differences between the various therapy strategies. Fifteen% of the coronoid process fractures were reconstructable to a limited extent only by means of osteosynthesis. In 33% of the patients, instabilities remained. The average extension/flexion came to 107° (SD 28), and pronation and supination 153° (SD 38).

CONCLUSION

At present, a surgical therapy of ligamentary injuries cannot be statistically justified. A stable osseous reconstruction appears to make more sense. The strongest negative prognostic parameters in our patient population were: therapy with an external fixator, immobilisation for more than 21 days, the occurrence of complications and unstable osteosyntheses on the coronoid process.

Coronoid fractures

Coronoid fractures are rarely isolated injuries; they are most commonly encountered in association with other elbow injuries as part of 3 major instability patterns. Type 1 fractures are usually associated with terrible triad injuries. Type 2 fractures are associated with varus posteromedial rotatory instability. Type III fractures are associated with transolecranon fracture-dislocations. Current recommendations are to repair all coronoid fractures associated with elbow instability, regardless of fragment size. Surgical techniques are described in detail.

An anatomic study of coronoid cartilage thickness with special reference to fractures

BACKGROUND

Current coronoid fracture classification systems are based on fragment size and configuration using plain radiographs and/or computed tomography (CT). During surgery, coronoid fracture fragments appear much larger than anticipated because cartilage is radiolucent and therefore not accounted for with preoperative imaging. The purpose of this imaging study was to quantify the articular cartilage thickness of the coronoid, with reference to coronoid fractures.

MATERIALS AND METHODS

Twenty-four cadaveric ulnae were dissected, imaged with CT, and analyzed by use of image analysis software. Thirteen identifiable landmarks were chosen on the coronoid, olecranon, and proximal radioulnar joint to measure articular cartilage thickness. Intraobserver reliability and interobserver reliability were determined.

RESULTS

Cartilage thickness was highest at the coronoid tip, with a mean of 3.0 mm (range, 1.7-4.6 mm). Cartilage thickness at the tip correlated inversely with age (P < .01) and correlated strongly with overall ulnar height and ulnar length (P < .05). All measurements had excellent intraobserver and interobserver reliability.

CONCLUSION

The thickness of cartilage on the coronoid tip is not inconsequential. The results of this study indicate that a 2-mm coronoid tip fracture on CT scan may actually appear to be a mean of 5 mm thick when viewed at the time of surgery. Clinically, this is important because it may alter the classification, the decision to treat, or the type of fixation used. Importantly, biomechanical cadaveric studies assessing coronoid injuries have incorporated cartilage thickness into coronoid size measurements when creating simulated fractures; therefore, it is critical that the conclusions of such biomechanical studies be scrutinized with regard to their clinical recommendations. Surgeons should be aware of these discrepancies.

Fractures of the ulnar coronoid process

The ulnar coronoid process plays a central role in elbow stability due to its unique anatomic characteristics. A fracture of the coronoid, although uncommon, represents a serious injury that can adversely affect functional outcome if not treated appropriately. Several surgical interventions addressing different fracture patterns are being increasingly recognised as effective treatment options even for smaller fragments. A review of the literature was performed in order to evaluate different treatment strategies applied to clearly defined fracture configurations. 14 articles reporting data for the management of 236 coronoid fractures met our inclusion criteria and were subjected to critical analysis. The data suggest that recognition of specific coronoid fracture patterns, use of appropriate classification systems and application of staged surgical protocols can stabilise the elbow effectively and lead to favourable outcomes.

The epidemiology of fractures of the proximal ulna

INTRODUCTION

The aim of our study was to report the epidemiological characteristics of fractures of the proximal ulna.

METHODS

From our prospective trauma database of 6872 fractures, we identified all acute fractures of the proximal ulna from a 1-year period between July 2007 and June 2008. Age, gender, mode of injury, fracture classifications, associated injuries and treatment were the factors documented and analysed.

RESULTS

There were 78 fractures of the proximal ulna with a mean age of 57 years (15-97). Males (n=35) sustained their fracture at a significantly younger age than females (p=0.041), with no gender predominance seen (p=0.365). The overall fracture distribution was a unimodal older male and unimodal older female type-F curve. The most common mode of injury was a simple fall from standing height (n=52, 67%), with younger patients more likely to sustain their injuries following a high-energy mechanism such as sports or a motor vehicle collision (p<0.001). Seventeen (22%) patients sustained associated injuries to the ipsilateral limb, with an associated proximal radial fracture most frequent (n=13, 17%). Open fractures were seen in five (6.4%) patients. A total of 64 patients had a fracture of the olecranon, with the Mayo 2A most frequently seen (n=47, 60%).

CONCLUSIONS

Fractures of the proximal ulna are fragility fractures that predominantly occur in elderly patients. Given the number of elderly patients sustaining these injuries, research is needed to determine the role of non-operative treatment for these fractures, particularly in patients with multiple co-morbidities and low functional demands.

The pivotal role of the intermediate fragment in initial operative treatment of olecranon fractures

BACKGROUND

In order to improve initial operative treatment of complex olecranon fractures we searched for new determining details. We assumed that the intermediate fragment plays a decisive role for anatomic restoration of the trochlear notch and consecutive outcome of initial operative treatment.

METHODS

80 patients operated with diagnosis of complex olecranon fracture were identified in an 8-year-period from trauma unit files at two European Level 1 Trauma Centers. Retrospective review of all operative reports and radiographs/computer-tomography scans identified patients with concomitance of an intermediate fragment. The Patient-Rated Elbow Evaluation Score was calculated for 45 of 80 patients at a minimum of 8 months postoperatively (range 8-84 months).

RESULTS

29 patients were treated with stable internal fixation with figure-of-eight tension band wire fixation and 51 patients with posterior plate osteosynthesis with/without intramedullary screw. An intermediate fragment was seen in 52 patients. In 29 of these 52 patients, the intermediate fragment was described in operative report. 24 of these 29 patients were treated with posterior plate osteosynthesis, and 5 patients with figure-of-eight tension band wiring. Complications included superficial infection (2 patients), secondary dislocation (3 patients) and heterotopic ossifications (1 patient). Functional outcome demonstrated a total PREE score of 9 points on average in 45 of 80 patients.

CONCLUSION

An extraordinary amount of patients showed an intermediate fragment. Consideration, desimpaction and anatomic reduction of the intermediate fragment are necessary preconditions for anatomic restoration of the trochlear notch. There is no clear benefit for plating versus tension band wiring according to our data. In the operative report precise description of the fracture pattern including presence of an intermediate fragment is recommended.

The comparative stability of screw versus plate versus screw and plate coronoid fixation

PURPOSE

To compare the biomechanical characteristics of screw versus plate versus both screw and plate fixation for large, type 3 O'Driscoll coronoid fractures.

METHODS

Synthetic ulnas had 70% of their coronoids cut. Fixation was performed with either a cannulated screw, a plate, or both a screw and a plate. Energy to failure, force at failure, first cycle stiffness, and stiffness at failure were measured on a servohydraulic testing machine under cyclic posterior axial loading.

RESULTS

The combination of a plate and screw had significantly greater energy to failure (83 Nm), force required to cause failure (634 N), and stiffness at failure (387 N/mm) compared to either an isolated plate (38 Nm, 474 N, 237 N/mm, respectively) or a screw (10 Nm, 279 N, 149 N/mm, respectively). For energy to failure and force required to cause failure, the plate group significantly outperformed the screw group. There was no significant difference in stiffness at the time of failure between the plate and screw groups.

CONCLUSIONS

For type 3 O'Driscoll coronoid fractures or nonunions when both a screw and a plate can be placed, the combination of these 2 fixation devices appears to produce significantly greater biomechanical stability than either fixation device alone.