2015 Young Investigator Award Winner: Cervical Nerve Root Displacement and Strain During Upper Limb Neural Tension Testing: Part 1: A Minimally Invasive Assessment in Unembalmed Cadavers.

STUDY DESIGN: A cross-sectional cadaveric examination of displacement and strain measured at the level of the cervical nerve roots during upper limb neural tension testing (ULNTT) with median nerve bias. OBJECTIVE: To determine the displacement and strain of cervical nerve roots C5-C8 during ULNTT with minimal disruption of surrounding tissues. SUMMARY OF BACKGROUND DATA: Clinical examination of neural pathology involving cervical nerve roots is difficult because of the transient nature of pathologies, such as cervical radiculopathy, entrapment neuropathies, and thoracic outlet syndrome. Cadaveric studies have demonstrated significant displacement and strain in lumbosacral nerve roots during neurodynamic testing of the lower extremity. Examination into the biomechanical behaviors of cervical nerve roots during ULNTT has not been performed. METHODS: Eleven unembalmed cadavers were positioned supine as though undergoing ULNTT. Radiolucent markers were implanted into cervical nerve roots C5-C8. Posteroanterior fluoroscopic images were captured at resting and ULNTT positioning. Images were digitized and displacement and strain were calculated. RESULTS: ULNTT resulted in significant inferolateral displacement (average, 2.16 mm-4.32 mm, P < 0.001) of cervical nerve roots C5-C8. There was a significant difference in inferolateral displacement between the C5 and C6 nerve roots (3.15 mm vs. 4.32 mm, P = 0.009). ULNTT resulted in significant strain (average, 6.80%-11.87%, P < 0.001) of cervical nerve roots C5-C8. There was a significant difference in strain between the C5 and C6 nerve roots (6.60% vs. 11.87%, P = 0.03). CONCLUSION: ULNTT caused significant inferolateral displacement and strain in cervical nerve roots C5-C8. These results provide the mechanical foundation for the use of ULNTT in clinical evaluation of pathology in the cervical region, such as in cervical radiculopathy, entrapment neuropathies, and thoracic outlet syndrome. LEVEL OF EVIDENCE: 2.

2015 Young Investigator Award Winner: Cervical Nerve Root Displacement and Strain During Upper Limb Neural Tension Testing: Part 2: Role of Foraminal Ligaments in the Cervical Spine.

STUDY DESIGN: A cross-sectional cadaveric examination of the mechanical effect of foraminal ligaments on cervical nerve root displacement and strain. OBJECTIVE: To determine the role of foraminal ligaments by examining differences in cervical nerve root displacement and strain during upper limb neural tension testing (ULNTT) before and after selective cutting of foraminal ligaments. SUMMARY OF BACKGROUND DATA: Although investigators have determined that lumbar spine foraminal ligaments limit displacement and strain of lumbosacral nerve roots, similar studies have not been conducted to prove that it is true for the cervical region. Because the size, shape, and orientation of cervical spine foraminal ligaments are similar to those in the lumbar spine, it is hypothesized that foraminal ligaments in the cervical spine will function in a similar fashion. METHODS: Radiolucent markers were implanted into cervical nerve roots C5-C8 of 9 unembalmed cadavers. Posteroanterior fluoroscopic images were captured at resting and upper limb neural tension testing positioning before and after selective cutting of foraminal ligaments. RESULTS: Selective cutting of foraminal ligaments resulted in significant increases in inferolateral displacement (average, 2.94 mm [ligaments intact]-3.87 mm [ligaments cut], P < 0.05) and strain (average, 9.33% [ligaments intact]-16.31% [ligaments cut], P < 0.03) of cervical nerve roots C5-C8 during upper limb neural tension testing. CONCLUSION: Foraminal ligaments in the cervical spine limited cervical nerve root displacement and strain during upper limb neural tension testing. Foraminal ligaments seem to have a protective role, reducing displacement and strain to cervical nerve roots during tension events. LEVEL OF EVIDENCE: 2.

Validity of musculoskeletal ultrasound for identification of humeroradial joint chondral lesions: a preliminary investigation.

CONTEXT: Epicondylalgia is a common condition involving pain-generating structures such as tendon, neural, and chondral tissue. The current noninvasive reference standard for identifying chondral lesions is magnetic resonance imaging. Musculoskeletal ultrasound (MUS) may be an inexpensive and effective alternative. OBJECTIVE: To determine the intrarater reliability and validity of MUS for identifying humeroradial joint (HRJ) chondral lesions. DESIGN: Cross-sectional study. SETTING: Clinical anatomy research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-eight embalmed cadavers (14 women, 14 men; mean age = 79.5 ± 8.5 years). MAIN OUTCOME MEASURE(S): An athletic trainer performed MUS evaluation of each anterior and distal-posterior capitellum and radial head to identify chondral lesions. The reference standard was identification of chondral lesions by gross macroscopic examination. Intrarater reliability for reproducing an image was calculated using the intraclass correlation coefficient (3,k) for measurements of the articular surface using 2 images. Intrarater reliability to evaluate a single image was calculated using the Cohen κ for agreement as to the presence of chondral lesions. Validity was calculated using the agreement of MUS images and gross macroscopic examination. RESULTS: Intrarater reliability was 0.88 (95% confidence interval = 0.77, 0.94) for reproducing an image and 0.93 (95% confidence interval = 0.80, 1.06) for evaluating a single image. Identifying chondral lesions on all HRJ surfaces with MUS demonstrated sensitivity = 0.93, specificity = 0.28, positive predictive value = 0.58, negative predictive value = 0.77, positive likelihood ratio = 1.28, and negative likelihood ratio = 0.27. CONCLUSIONS: Musculoskeletal ultrasound is a reliable and sensitive tool for a clinician with relatively little experience and training to rule out HRJ chondral lesions. These results may assist with clinical assessment and decision making in patients with lateral epicondylalgia to rule out HRJ chondral lesions.