Soft tissue pathology: regional pain syndromes, nerves and ligaments

The sonoanatomy of lumbar erector spinae and its iliac attachment - the potential substrate of the iliac crest pain syndrome, an ultrasound study in healthy subjects

Background

Iliac crest pain syndrome is a regional pain syndrome that has been identified in many patients with low back pain. Based on anatomical studies, it was suggested that the potential substrate of this syndrome might be the enthesis of the erector spinae muscle at the posterior medial iliac crest. As there have been no imaging studies of this important enthesis, our aim was to assess its characteristics by ultrasound.

Methods

Erector spinae enthesis was first studied in a cadaver. Then its characteristics were recorded in 25 healthy volunteers (median age: 28.92, SD: 5.31, mean Body Mass Index 22.61, SD: 3.38), with Esaote My Lab 7 machine using linear transducer (4–13 MHz).

Results

The cadaver study confirmed the attachment of a substantial part of erector spinae to a well-defined region on the medial posterior iliac crest. The US study in the volunteers consistently showed the entheses as typical hyperechoic fibrillar structures, slightly oblique to the skin in the longitudinal plane and attaching to the iliac crest. In the transverse plane, the entheses were seen as oval, densely dotted structures in contact with the superior edge of posterior superior iliac spine. Their mean thickness (4.9 ± 0.6 and 5.2 ± 0.7 mm longitudinally; 4.3 ± 0.6 and 4.4 ± 0.7 mm transversely), maximum width (16.3 ± 2.8 and 15.7 ± 2.3 mm) and depth (10.8 ± 7.3 and 10.6 ± 6.2 mm) on the left and right side, respectively, as well as their echostructure were recorded and described.

Conclusions

The erector spinae entheses could be assessed in detail by ultrasound, thus their pathological transformation associated with iliac crest pain syndrome could be identified.

Comparing Point-of-care-ultrasound (POCUS) to MRI for the Diagnosis of Medial Compartment Knee Injuries

Background:

Ultrasound has become an increasingly utilized tool for the imaging of the musculoskeletal system, especially for imaging the components of the knee. Even though MRI is touted as being the golden standard for identifying knee pathologies, the use of ultrasound has gained popularity in this field given its ability for rapid diagnosis. This study aims to investigate the efficacy of point-of-care ultrasound (POCUS) to diagnose injuries to the medial knee compartment when compared to magnetic resonance imaging (MRI).

Methods:

This was a prospective, observational study conducted at an orthopedic outpatient clinic. Prospective patients with medial knee pain scheduled for an MRI of the knee were evaluated by POCUS prior to the MRI. Sonographic findings were then compared to MRI results to assess correlation.

Results:

Nine patients were enrolled in the study. Median age was 53 years and eight were male (89%). POCUS demonstrated 100% sensitivity and 50% specificity for medial meniscus tear and 67% sensitivity and 83% specificity for medial collateral ligament (MCL) tear.

Conclusion:

Ultrasound may have a role as the initial rapid imaging modality in patients with suspected medial meniscus or MCL tears as it is highly sensitive, and it may serve as an effective screening tool for patients with both acute and chronic knee pain.