Involvement of the proximal radial ulnar joint in partial radial head fractures: a novel three-dimensional computed tomography scan evaluation method

Partial articular fractures of the radial head: How to understand them using computed tomography

BACKGROUND

The optimal treatment for different types of displaced partial articular radial head fractures is still debatable. Fractures involving the articulating portion of the radial head can be defined also as bi-articular and are often underestimated. Moreover, the complete loss of periosteal contact between fracture fragments is a marker of instability. Available classifications do not emphasize these aspects. The purpose of the present study is to describe two assessment methods to identify fractures involving the articulating portion of the radial head and complete loss of periosteal contact with the help of 2D-3D CT scan. The second purpose is to propose a classification of the displaced partial articular radial head fractures basing on these two assessment methods.

HYPOTHESIS

We hypothesize that the proposed classification is reliable.

PATIENTS AND METHODS

By observing the position of the bicipital tuberosity with respect to the ulna in reference to the coronal plane in the 3D-CT scan and by observing the location of the fracture fragment in the 2D axial scan, it is possible to understand if a displaced partial articular fracture involves the articulating portion of the radial head. Also, it is possible to understand the presence or absence of a complete loss of periosteal contact between the two fracture fragments by observing the coronal and sagittal 2D-CT scans. We identified 20 displaced partial articular radial head fractures on a series of 149 patients with radial head fractures. Following the above-described assessment methods, these 20 fractures were classified in three subgroups. Also, seven evaluators were asked to use these assessment methods to classify these 20 fractures in the three subgroups, in order to evaluate inter- and intra-observer agreement.

RESULTS

Eight fractures involved the non-articulating portion of the radial head with complete loss of periosteal contact, eight involved the non-articulating portion of the radial head without complete loss of periosteal contact, and four involved the articulating portion of the radial head with or without complete loss of periosteal contact. The kappa for intra-observer reliability ranged from 0.46 to 0.84. The average kappa for inter-observer reliability was 0.570 (range: 0.526 to 0.676). The Kendall's coefficient for inter-observer concordance was 0.673.

DISCUSSION

Prognostically, displaced partial fractures of the articulating portion of the radial head could differ from the other types, regardless of whether or not there is a complete loss of periosteal contact. Underestimating this fracture pattern can lead to poor results due to risk of forearm rotation blockage. Moreover, underestimating complete loss of periosteal contact in displaced partial fractures of the non-articulating portion of the radial head could lead to poor results. The described evaluation methods have moderate reliability, but can represent, along with other described methods, a good starting point to better understand and treat these insidious fractures.

LEVEL OF EVIDENCE

III; retrospective study.

Incidence and pattern of concurrent capitellum fracture associated with radial head and neck fractures

BACKGROUND

Radial head and neck fracture is a common fracture around the elbow. It is mostly caused by axial or valgus loading after a fall in elbow extension and forearm pronation. When a radial head and neck fracture occurs, the capitellum collides with the radial head and experiences a shear force, leading to capitellum fracture. The primary aim of this study was to evaluate the incidence of concurrent capitellum fracture and analyze its patterns among patients treated for radial head and neck fractures based on computed tomography. Secondary aim is to determine factors associated with concurrent capitellum fractures.

HYPOTHESIS

Capitellum fractures are more common than expected in radial head and neck fractures and show a consistent pattern. With the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture will be shown.

METHODS

A total of 101 patients treated surgically (27 patients) or non-surgically (74 patients) for radial head and neck fractures from January 2017 to December 2020 were retrospectively analyzed. Initial computed tomography was reviewed to identify concurrent capitellum fractures. A fracture was diagnosed when the bone continuity was lost in two consecutive images in any one of the three directions of computed tomography scan images. Seventeen patients with capitellum fractures were classified as group 1 and 84 patients without capitellum fractures as group 2. Each group of patients was assessed using Mason classification, whether fracture extended to the radial neck or not, fracture location, and treatment method. To determine the fracture location, radial head was trisected using three anatomical landmarks: safe zone, posteromedial zone, and anteromedial zone. And it was determined as the location where the fracture was most comminuted.

RESULTS

The average age of the 101 patients was 44.6 years old. There were 54 (53.5%) males and 47 (46.5%) females. Capitellum fracture was accompanied in 17 cases. Its incidence was 16.8%. The rate of accompanying capitellum fracture was 9.5% (6/63) for Mason type 1, 25.0% (6/24) for Mason type 2, and 41.7% (5/12) for Mason type 3. The ratio of radial neck extension of fracture was significantly higher in group 2. There was no isolated radial neck fracture in group 1. However, there were 33 in group 2. After eliminating isolated radial neck fracture patients, significantly more fractures were located in the safety zone in group 1. Group 1 had a significantly higher rate of surgical treatment than group 2 (52.9% (9/17) vs. 21.4% (18/84) p=0.007).

CONCLUSION

For radial head and neck fractures, the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture. When the fracture extended to the radial neck, the comorbidity of the capitellum fracture was decreased. Among radial head fractures, when the fracture was located in the safe zone, the comorbidity of capitellum fracture was increased. The rate of surgical treatment was higher in radial head and neck fracture patients with concurrent capitellum fractures.

LEVEL OF EVIDENCE

IV; diagnostic study.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Elbow

ABSTRACT

In this dynamic protocol, ultrasound examination of the elbow using different maneuvers is described for several/relevant elbow problems. Scanning videos are coupled with real-time patient examination videos for better understanding. The authors believe that this practical guide-prepared by an international consensus of several experts (EURO-MUSCULUS: European Musculoskeletal Ultrasound Study Group and USPRM: Ultrasound Study Group of ISPRM [International Society of Physical and Rehabilitation Medicine])-will help musculoskeletal physicians perform a better and uniform/standard approach.

Radial head fractures: a quantitative analysis

Several classification systems for radial head fractures discuss the number of fragments and their displacement, but not the exact location. This study aimed to evaluate the location of the radial head fracture fragments and the influence of the Mason type on the size of the fracture fragment. Forty-one radial head fractures (31 Mason type I and 10 type II) with an elliptical radial head were included in this retrospective study and 3D reconstructed. First, the fragments were repositioned to their original location. Next, the orientation of the scanned forearm was evaluated using the position of the longest axis relative to the proximal radio-ulnar joint, and all radial heads were rotated to the neutral rotation. The radial head was divided into 4 quadrants (anteromedial, anterolateral, posteromedial, and posterolateral). The location of the fracture line in correlation with these 4 quadrants was evaluated. All fracture fragments were located in the anteromedial quadrant. Thirty-eight (93%) were located in the anterolateral quadrant. The posterolateral quadrant was involved in 32%. At last, the average fracture fragment size was evaluated according to the Mason classification. A significant difference was found in the average fracture fragment size between Mason type I (38% of the radial head surface) and type II (48% of the radial head surface). It was concluded that there is an important involvement of the anterior quadrants of the fracture. The mean size of the fracture is significantly larger in Mason type II compared to type I.

Factors affecting outcome of partial radial head fractures: A Retrospective Cohort Study

BACKGROUND

The purpose of this study is to evaluate which factors will affect range of motion (ROM) and function in partial radial head fractures. The hypothesis is that conservative treatment yields better outcomes.

MATERIALS AND METHODS

This retrospective comparative cohort study included 43 adult volunteers with partial radial head fracture, a minimum 1-year follow up, separated into a surgical and non-surgical group. Risk factors were: associated injury, heterotopic ossification, worker's compensation, and proximal radio ulnar joint (PRUJ) implication. Outcomes included radiographic ROM measurement, demographic data, and quality of life questionnaires (PREE, Q-DASH, MEPS).

RESULTS

Mean follow up was 3.5 years (1-7 years). Thirty patients (70%) had associated injuries with decreased elbow extension (-11°, p=0.004) and total ROM (-14°, p=0.002) compared to the other group. Heterotopic ossification was associated with decreased elbow flexion (-9.00°, p=0.001) and fractures involved the PRUJ in 88% of patients. Only worker's compensation was associated with worse scores. There was no difference in terms of function and outcome between patients treated non-surgically or surgically.

DISCUSSION

We found that associated injuries, worker's compensation and the presence of heterotopic ossification were the only factors correlated with a worse prognosis in this cohort of patients. Given these results, the authors reiterate the importance of being vigilant to associated injuries.

LEVEL OF EVIDENCE

IV, Retrospective study.