Ultrasonography and magnetic resonance imaging of elbow ligaments: a comparative study

Ultrasonographic examination of acute soft tissue lesions in the elbow has good inter-rater reliability and acceptable agreement with magnetic resonance imaging

BACKGROUND

Ultrasonography (US) has been suggested as a valuable complement to clinical and radiologic examinations in elbow trauma. Magnetic resonance imaging (MRI) has been the method of choice, despite fair to moderate inter-rater reliability (IRR). US has potential advantages but is assessor dependent and the IRR scarcely examined. The primary aim of the present study was to investigate IRR for US and secondarily interobserver agreement (IOA) between US and MRI in the acute phase after elbow trauma. Acute phase was defined as 2 weeks and, if applicable, the following weekend. The hypothesis was that US reliability would be at least substantial for complete muscle or ligament lesions.

METHODS

A total of 116 patients (50 men, median age 47 [range 19-87] years) who had an elbow trauma with dislocation and/or fracture were included. Exclusion criteria were prior injury to the same elbow, and US and/or MRI not possible within 16 days. During US, the condition of muscle origins at the epicondyles and collateral and annular ligament complexes was recorded in a predesigned protocol, with the alternatives intact, partially or completely torn. Seventy-two patients had a second US examination the same day by an independent upper extremity surgeon, and 58 of the 116 patients underwent an MRI before or after the US, evaluated by 2 radiologists using the same protocol. IOA and IRR between assessors and modalities were analyzed with kappa statistics and interpreted according to Landis and Koch. Perfect agreement (PA) was reported in percentages.

RESULTS

US examination within 2 weeks was feasible with tolerable discomfort. Defining muscle origins and ligaments as intact or completely torn, the US IRR ranged from substantial to near perfect (kappa 0.63-1, PA 93%-100%). Intact tissues vs. tear (partial and complete tear combined) or intact vs. partial vs. complete tear resulted in kappa values from moderate to substantial and PA 74%-96% with lowest reliability for the muscle origins. The IOA between MRI and US ranged from fair to near perfect for no tear vs. complete tear (kappa 0.25-1, PA 65%-100%). Agreement between no tear and tear (partial and complete together) ranged from fair to substantial (0.25-0.66, PA 63%-89%) and no tear vs. partial or complete tear ranged from fair to moderate (0.25-0.53, PA 50%-79%).

CONCLUSION

US in the acute setting is suitable and reliable for diagnosis of ligament injuries in the elbow and is in addition fast, cheap, and easily accessible. The agreement with MRI seems to vary with the structure assessed and severity of the lesions, ranging from fair to near perfect.

The sonographic posterolateral rotatory stress test: Normal ulnohumeral gap difference in healthy volunteers

Background: The sonographic posterolateral rotatory stress test may be a good preoperative diagnostic tool for posterolateral rotatory instability, especially in atraumatic or occult cases. However, there is lack of study on the living population or the normal elbow. Hypothesis/Purpose: This study evaluates the ulnohumeral opening gap difference between elbows in resting and stress positions while performing ultrasonography in normal healthy volunteers. The hypothesis is that the normal ulnohumeral opening gap difference is less than 2 mm. Methods: A total of 21 participants (9 males and 12 females) who presented at our institution between May and June 2021 were recruited. First, participants with elbow deformity, major elbow trauma, history of injection or surgery around the elbow, or evidence of elbow instability were excluded. Only healthy elbows without symptoms were included in this study. Participants' both elbows were examined using ultrasonography. The ulnohumeral gap was measured in millimeters, and the difference was calculated from the means of ulnohumeral gap in resting and stress positions. Results: The mean age of participants was 36.14 years old. No samples with hyperlaxity were included. Overall, the means of ulnohumeral gap in resting and stress positions were 2.55 ± 0.69 mm and 3.16 ± 0.80 mm, respectively. The average mean of overall ulnohumeral opening gap difference was 0.61 ± 0.32 mm. There was no statistically significant difference between males and females (p = .989). The intraobserver reliability was 0.89 and 0.9 for resting and stress positions, respectively. Conclusion: The sonographic posterolateral rotatory stress test shows that the ulnohumeral opening gap difference between resting and stress positions is less than 2 mm in healthy volunteers. Clinical Relevance: In patients with inconclusively-diagnosed PLRI, the sonographic posterolateral rotatory stress test may be a reliable preoperative diagnosis tool, providing its non-invasiveness and the ability to assess the contralateral side as a comparison.

Ultrasonography: an interesting imaging method for ligament assessment during the acute phase of closed elbow injuries

PURPOSE

To evaluate whether ultrasonography can be used to explore the medial and lateral ligament structures during the acute phase of a closed elbow injury.

METHODS

A single-center, prospective study performed between December 2019 and June 2020, including patients who suffered a radial head fracture or elbow dislocation. Two radiologists did a blinded analysis using ultrasonography of visibility, injury grade, and presence of bone avulsion for the radial collateral ligament (RCL), lateral ulnar collateral ligament (LUCL), annular ligament (AL), and anterior (MCLant) and posterior bundles (MCLpost) of the medial collateral ligament. The inter-rater agreement was calculated. The ultrasonography findings were compared with the intraoperative findings in the patients who subsequently underwent surgery.

RESULTS

Forty patients were included (28 radial head fractures and 12 elbow dislocations). The inter-rater agreement was strong for all the study parameters (kappa between 0.65 and 1), except for the visibility of the LUCL (kappa 0.52) and the visibility and appearance of the MCLpost (kappa 0.54 and 0.47, respectively). The injured ligaments were thicker than their contralateral counterparts (p < 0.05). In the 10 patients who underwent surgery, the radiological-surgical correlation was 100% for the RCL and medial ligaments and 70% for the LUCL.

CONCLUSION

Ultrasonography is a reproducible examination that can be used to assess the damage to elbow ligaments during the acute phase following an injury. This examination could be incorporated into the exploration protocol for elbow injuries during the preoperative assessment and to adapt the treatment.

Elbow Stiffness Imaging: A Practical Diagnostic and Pretherapeutic Approach

Loss of elbow motion can lead to disability in everyday gestures, recreational activities, and work. Unfortunately, the elbow joint is particularly prone to stiffness because of its complex anatomy and biomechanics. The etiology of elbow stiffness is varied and must be diagnosed accurately in order to allow optimal treatment, which may be challenging for surgeons and physiotherapists. Its treatment can be either conservative, arthroscopic or surgical, with a trend for arthroscopic procedures when conservative treatment fails. There is no consensus on the optimal imaging workup for elbow joint stiffness, which may have an impact on patient management. This article reviews the current classification systems of elbow stiffness and the various imaging techniques used for diagnosis. Report checklists and clarifications on the role of each imaging method, as well as the imaging findings of normal and stiff elbows, are presented, leading to a proposed diagnostic algorithm. The main concern in imaging is to determine the cause of elbow stiffness, as many concomitant abnormalities might be present depending on the clinical scenario.

Feasibility and technique of ultrasound traumatic elbow lesion assessment

INTRODUCTION

The present study aimed to describe the technique of ultrasound traumatic elbow lesion assessment performed by an orthopedic surgeon.

METHODS

Nine patients were included in a single-center study. Clinical examination assessed pain, ranges of elbow motion, neurovascular status and elbow ligament testing. Ultrasound was associated to radiography between days 7 and 15, screening for lesions of the bone, medial ligament (in 30-90° flexion), lateral ligament (elbow at 90° in cobra position) and epitrochlear and epicondylar muscle insertions. Ultrasound scanning time and echogenicity were assessed.

RESULTS

Four radial head osteochondral fractures were detected on ultrasound in addition to the 4 fractures seen on radiography, without significant difference (p=0.071). Clinical examination found 2 cases of valgus laxity and 5 of varus laxity. Ultrasound, performed blind to radiography, found 1 medial collateral ligament anterior bundle lesion (in 1 of the 2 patients with valgus laxity) and 4 lateral collateral ligament ulnar bundle lesions (in 4 of the 5 patients with varus laxity). There were no epicondylar or epitrochlear tendon lesions. Scanning time decreased significantly over the study period, from a mean 30minutes in the first 5 cases to a mean 24.8minutes in the last 5 (p=0.046). Three patients could not be put in the cobra position, and 3 showed poor echogenicity.

DISCUSSION

Ultrasound assessment of traumatic elbow lesions could be performed by an orthopedic surgeon on a well-defined protocol. Lesions on ultrasound matched clinical symptomatology. Inter- and intra-observer reproducibility remain to be assessed.

LEVEL OF EVIDENCE

IV.