Reliability and validity of the Wrightington classification of elbow fracture-dislocation

Reliability of the CURL classification for proximal ulna fracture-dislocations of the elbow

Background

Proximal ulna fracture-dislocations are challenging injuries with a myriad of existing classification systems. The Coronoid, proximal Ulna, Radius, and Ligaments classification (CURL) is a simple framework designed to focus attention on the key components affecting outcome and guide surgical management. This study evaluates interobserver and intraobserver reliability of this new classification.

Methods

Four observers independently reviewed plain radiographs and computed tomography (CT) scans of patients with proximal ulna fracture-dislocations. Each observer scored the Coronoid (C), proximal Ulna (U), and Radius (R) components for each fracture on 2 occasions. The osseous components were subclassified as 'intact', 'simple', or 'complex'. The Ligament component (L) was not rated as this requires intraoperative classification. Interobserver and intraobserver reliability was calculated using Cohen's weighted kappa coefficients. X-ray and CT were compared for patients with both imaging modalities. The Landis and Koch criteria were used to interpret the strength of the kappa statistics.

Results

One hundred seventy seven patients had plain X-rays; 58 patients had both X-ray and CT scans. Overall, in the X-ray only cohort, there was 'almost perfect' interobserver reliability for the radial head (k = 0.94) and coronoid (k = 0.83), and 'substantial' reliability (k = 0.68) for the proximal ulna. For the X-ray and CT cohort, interobserver reliability was 'almost perfect' across both modalities for the radial head (k = 0.88 and k = 0.93, respectively) and 'moderate' for the proximal ulna (k = 0.48 and k = 0.52, respectively). For the coronoid, interobserver reliability for X-ray interpretation was 'substantial' (k = 0.74) and for CT was 'almost perfect' (k = 0.89). Intraobserver reliability was 'almost perfect' for all components, other than CT assessment of the proximal ulna which demonstrated 'substantial' reliability (k = 0.74).

Conclusion

The Coronoid, proximal Ulna, Radius, and Ligaments classification demonstrates strong interobserver and intraobserver reliability, supporting use of the classification for proximal ulna fracture-dislocations. CT is recommended for improved characterization of any fracture with a coronoid component.

"How the Wrightington classification of traumatic elbow instability can simplify the algorithm for treatment"

There are numerous injury patterns of elbow-fracture dislocation that can lead to confusion about the best surgical management. The Wrightington classification aims to provide a simple categorization based on the injury to the coronoid process and the three column concept of the elbow osseous stability that describes a medial column consisting of the anteromedial coronoid facet and sublime tubercle, the middlecolumn is the anterolateral coronoid facet, and the lateral column is the radial head and lateral ligament complex with a fulcrum for varus/valgus stability between the two coronoid facets. Injuries are classified as type A (anteromedial facet/medial-column), B (bifacet/ medial and middle-columns), B+ (bifacet with radial head/all three columns), C (combined radial head and anterolateral facet/middle and lateral-columns), D (distal to coronoid where coronoid is in continuity with olecranon process), and D+ (distal to coronoid with radial head fracture). With each bony injury pattern, we can anticipate which soft tissue constraints are likely to be involved and the importance of their repair to restore stability, and thereby develop algorithms for management. The Wrightington classification has been shown to be reliable and valid. A consecutive series of 60 patients with elbow-fracture dislocation managed according to the surgical algorithms of the Wrightington classification have been reported to have excellent outcomes with a median Mayo Elbow Performance Score of 100 (interquartile 85-100) and flexion/extension arc of movement of 123° (interquartile 101°-130°). In conclusion, the Wrightington classification of elbow-fracture dislocation is a comprehensive, reliable, and valid classification with treatment algorithms that are associated with good functional outcomes.

Predicting the need for collateral ligament repair in transolecranon fractures of the elbow: a traffic light model

BACKGROUND

Biomechanical studies have shown that translation of the proximal radius relative to the capitellum in the sagittal plane can predict integrity of the collateral ligaments in a transolecranon fracture model; no studies have examined this in clinical practice.

METHODS AND MATERIALS

Nineteen consecutive transolecranon fracture dislocations were retrospectively reviewed. Data collection included patient demographics, fracture classifications, surgical management, and failure with instability. Distance between the center of the radial head and the center of the capitellum was measured on initial radiographs by 2 independent raters on 3 separate occasions. Statistical analysis was used to compare the median displacement between patients who required collateral ligament repair for stability and those who did not.

RESULTS

Sixteen cases with a mean age of 57 years (range 32-85) were analyzed with an inter-rater Pearson coefficient of 0.89 for displacement measurement. Median displacement where collateral ligament repair was needed and performed was 17.13 mm (interquartile range [IQR] = 10.43-23.88) compared with 4.63 mm (IQR = 2.68-6.58) where collateral ligament repair was not performed and not required (P = .002). In 4 cases, ligament repair was not performed initially but deemed necessary based on clinical outcome and postoperative and intraoperative images. Of these, the median displacement was 15.59 mm (IQR = 10.09-21.20), and 2 of these required revision fixation.

DISCUSSION

Where displacement on initial radiographs exceeded 10 mm, lateral ulnar collateral ligament (LUCL) repair was required in all cases (red group). If less than 5 mm, ligament repair was not required in any case (green group). Between 5 and 10 mm, following fracture fixation, the elbow must be screened carefully to assess for any instability and a low threshold set for LUCL repair to prevent posterolateral rotatory instability (amber group). Using these findings, we propose a traffic light model to predict the need for collateral ligament repair in transolecranon fractures and dislocation.

Evaluation of Surgical Approaches to Management of Traumatic Posteromedial Elbow Instability Syndrome: A Systematic Literature Review Protocol

Posteromedial Instability Syndrome of the Elbow (PMIE) is a condition that arises from injuries to the stabilizing structures of the elbow joint, such as the coronoid process or ulnar lateral collateral ligament. Surgical treatment is commonly performed, but there is uncertainty regarding its results. This systematic review will synthesise the available evidence regarding the efficacy of surgical approaches to PMIE. Published and unpublished primary studies that regard outcomes of patients treated for PMIE, irrespective of approach, will be considered for inclusion. Iterative searches will be performed in the PubMed/MEDLINE, EMBASE, and Cochrane CENTRAL repositories from their inception to May 2023. Grey literature repositories will also be searched. The Cochrane risk of bias tool will be used to assess the quality of eligible interventional studies, while the MINORS tool will be employed for observational studies. If possible, a meta-analysis based on the random-effects model will be conducted. Heterogeneity will be assessed using Cochrane's Q and I2 statistics, and explored through subgroup analyses and sensitivity analyses. Relevant outcomes will include elbow joint functionality as assessed by validated scales, the proportion of patients returning to usual daily life activities, the development of recurrent joint instability in the postoperative period, quality of life and the development of postoperative arthritis. This protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the University of York. Its registration number is CRD42023451516.

Current concepts in the management of "Terrible Triad" injuries of the elbow

Terrible triad injuries of the elbow are complex injuries which can result in long term complications and significant disability. They must be identified correctly, and managed appropriately in order to maximise functional outcomes. A clear understanding of the bony and ligamentous anatomy is essential to plan appropriate surgical reconstruction to provide elbow stability. Urgent reduction of the elbow, followed by 3-dimensional imaging and surgical repair or replacement of the injured structures is the mainstay of treatment in the majority of cases. This review presents a summary of the relevant anatomy and the evidence for the management of these complex injuries.

Morphological Characteristics of Proximal Ulna Fractures: A Proposal for a New Classification and Agreement for Validation

Historically, proximal ulna fractures have been simplistically diagnosed and treated as simple olecranon fractures, leading to an unacceptable number of complications. Our hypothesis was that the recognition of lateral, intermediate, and medial stabilizers of the proximal ulna and ulnohumeral and proximal radioulnar joints would facilitate decision-making, including the choice of approach and type of fixation. The primary aim was to propose a new classification for complex fractures of the proximal ulna based on morphological characteristics seen on three-dimensional computed tomography (3D CT). The secondary aim was to validate the proposed classification regarding its intra- and inter-rater agreement. Three raters with different levels of experience analyzed 39 cases of complex fractures of the proximal ulna using radiographs and 3D CT scans. We presented the proposed classification (divided into four types with subtypes) to the raters. In this classification, the medial column of the ulna involves the sublime tubercle and is where the anterior medial collateral ligament is inserted, the lateral column contains the supinator crest and is where the lateral ulnar collateral ligament is inserted, and the intermediate column involves the coronoid process of the ulna, olecranon, and anterior capsule of the elbow. Intra- and inter-rater agreement was analyzed for two different rounds, and the results were evaluated according to Fleiss kappa, Cohen kappa, and Kendall coefficient. Intra- and inter-rater agreement values were very good (0.82 and 0.77, respectively). Good intra- and inter-rater agreement attested to the stability of the proposed classification among the raters, regardless of the level of experience of each one. The new classification proved to be easy to understand and had very good intra- and inter-rater agreement, regardless of the level of experience of each rater.

Functional outcomes of elbow injuries managed according to the Wrightington classification of elbow fracture-dislocations

Background

This study aims to review the functional outcomes of patients managed by the application of the Wrightington elbow fracture-dislocation classification system and its corresponding management algorithms.

Methods

This is a retrospective consecutive case series of patients over the age of 16 with an elbow fracture-dislocation managed according to the Wrightington classification. The primary outcome was the Mayo Elbow Performance Score (MEPS) at the last follow-up. Range of movement (ROM) and complications were collected as a secondary outcome.

Results

Sixty patients qualified for inclusion (32 female, 28 male) with a mean age of 48 years (19-84). Fifty-eight (97%) patients completed a minimum of three months follow-up. Mean follow-up was six months (3-18). The median MEPS at the final follow-up was 100 (interquartile range [IQR] 85-100) and median ROM of 123° (IQR 101-130) degrees. Four patients underwent secondary surgery and had improved outcomes with the average MEPS score improving from 65 to 94 following the second surgery.

Conclusions

The results of this study show that good outcomes can be achieved for complex elbow fracture-dislocations through pattern recognition and management with an anatomically based reconstruction algorithm as described by the Wrightington classification system.

Olecranon Fractures: A Critical Analysis Review

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Olecranon fractures account for 10% of all elbow fractures and are more likely to result from a low-energy injury. A displaced fracture with a stable ulnohumeral joint (Mayo type 2) is the most common type of injury.

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The management of an isolated olecranon fracture is based on patient factors (age, functional demand, and if medically fit to undergo surgery) and fracture characteristics including displacement, fragmentation, and elbow stability.

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Nonoperative management can be successfully used in undisplaced fractures (Mayo type 1) and in displaced fractures (Mayo type 2) in frail patients with lower functional demands.

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Patients with displaced olecranon fractures with a stable ulnohumeral joint without significant articular surface fragmentation (Mayo type 2A) can be managed with tension band wiring, plate osteosynthesis (PO), intramedullary fixation, or suture repair.

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PO is advocated for multifragmentary fractures and fractures that are associated with ulnohumeral instability. It is essential to consider the variable anatomy of the proximal ulna during surgery.

Survivorship of anatomic press-fit short-stem radial head replacement with a pyrocarbon bearing

BACKGROUND

Restoring the radial head as a stabiliser of the elbow is considered important in cases where there is an associated bony or ligamentous injury. A variety of radial head prostheses are available. There are no reports of the survivorship of a short-stem press-fit radial head prostheses with pyrocarbon bearing.

PATIENTS AND METHODS

With institutional review board approval, a retrospective case-note analysis was performed of a consecutive single-surgeon case series of the Integra LifeScience pyrocarbon radial head prostheses (Carbon Modular Radial Head) from October 2010 to October 2019 in a tertiary referral centre. The series was divided into acute trauma and salvage cohorts. Kaplan-Meier survivorship analysis was conducted.

RESULTS

36 patients were included, 23 (64%) for acute injuries and 13 (36%) for failed initial treatment. Of the acute injuries, 20 (87%) had a Wrightington type-C elbow fracture-dislocation. Reoperation was performed in 4 (11%) patients; 10 (28%) had possible loosening on radiographs. The implant survival rate was 94% at shortest follow-up of 17 months (mean 70 months).

DISCUSSION

Treatment of complex radial head fractures using a pyrocarbon-bearing, anatomic press-fit design provides satisfactory short-term survivorship in this case series. The implant should be used with caution in salvage cases, due to higher rates of loosening seen in this cohort.

Dislocations of the elbow - An instructional review

Dislocations of the elbow require recognition of the injury pattern followed by adequate treatment to allow early mobilisation. Not every injury requires surgery but if surgery is undertaken all structures providing stability should be addressed, including fractures, medial and lateral ligament insertion and the radial head. The current concepts of biomechanical modelling are addressed and surgical implications discussed.

The three-column concept of elbow joint stability and the Wrightington elbow fracture-dislocation classification, emphasizing the role of cross-sectional imaging

Elbow fracture-dislocation is a complex injury with a combination of osseous and soft tissue disruption. Different classification systems have been used to describe the injury pattern and help guide the management. The article describes the important cross-sectional findings in complex elbow fracture-dislocation injuries based on the relatively new Wrightington classification. This includes the various elements and patterns seen in elbow fracture-dislocations providing a simple and comprehensive system to classify these injuries and help guide the surgical management. The article also describes the three-column concept of elbow joint stability, dividing the elbow joint osseous structures into lateral, middle and medial columns. Detailed radiological assessment of the fractures pattern is vital to understand the mechanism of injury, allowing clinicians to predict the associated capsuloligamentous injury and help guide the management decisions. The Wrightington elbow fracture-dislocation classification categorizes the injuries according to the ulnar coronoid process and radial head fractures. Type A is an anteromedial coronoid fracture. Type B is a bifacet or basal coronoid fracture, with B + indicating associated radial head fracture. Type C is a combined anterolateral facet and radial head or comminuted radial head fractures. Type D is a diaphyseal ulnar fracture, with D + indicating associated radial head fracture.

Posteromedial rotatory instability of the elbow: What the radiologist needs to know

Varus posteromedial rotatory instability of the elbow joint is a relatively new subject described for the first time in 2003. It occurs secondary to axial loading of the elbow with varus force and internal rotation of the forearm. There is usually a specific pattern of osseous and soft tissue injuries that can be recognized on imaging. This includes an anteromedial coronoid fracture and avulsion of the lateral collateral ligament complex from its humeral attachment. Ulnar collateral ligament complex injury is also reported, particularly its posterior bundle which plays an important role in posteromedial elbow joint stability. There is high incidence of early osteoarthritis secondary to the resultant varus instability and increased contact pressure at the ulnohumeral joint. Surgical fixation of the coronoid fracture and ligamentous reconstruction maybe indicated to prevent this recurrent instability. The article reviews the key radiological features of posteromedial rotatory instability with multiple examples from different imaging modalities. The relevant anatomy of the elbow joint stabilising structures will be illustrated, in particular the coronoid process anatomy and the O'Driscoll classification for coronoid process fractures. Radiologists should be familiar with the imaging findings of posteromedial rotatory instability.