A 58-year-old male recently presented with ulnar nerve subluxation. He reported symptoms that were consistent with bilateral cubital tunnel syndrome. Specifically, he experienced numbness, tingling, and pain. These sensations originated at his elbow and extended down the side of his forearm, primarily affecting the areas near his pinky and ring fingers.
When considering bilateral cubital tunnel syndrome, it is important to evaluate potential contributing factors. One should rule out involvement from a cervical nerve root, such as a pinched nerve in the neck, which could lead to symptoms in both arms. However, in this case, a neck component was ruled out, as there was no evidence suggesting a cervical nerve issue contributing to the patient’s symptoms.
It is also notable that the severity of symptoms differed between the two sides; the patient’s left arm was affected more than the right.
One of the first things that we did was an ultrasound exam. You know, we want to look at ligaments, tendons around the elbow. Is the elbow stable? Is it unstable? Is there any reason to suspect that any kind of instability is at play that’s kind of knocking on that er nerve? You know, that those bones are moving more than they should.
Ultrasound Examination for Elbow Stability
We performed an ultrasound examination of the patient’s elbow to evaluate the ligaments and tendons surrounding the elbow joint. The procedure involves moving the patient’s arm through flexion and extension to observe the nerve’s behavior relative to the bone. This helps us determine whether the elbow is stable or unstable. The ulnar nerve is situated very close to the bone, making it susceptible to irritation or injury if instability is present.
The ultrasound examination also revealed important differences between the patient’s left and right arms. On the left side, which was the more symptomatic side, instability was found. The nerve is seen sliding over the bone during movement, which is identified as ulnar nerve subluxation—a condition where the nerve shifts out of place and flips over the bone. This can cause significant discomfort, including numbness, tingling, and pain, due to increased friction and pressure on the nerve during elbow motion.
A March 2026 study in the Journal of ultrasonography (1) wrote that high-resolution ultrasound has emerged as a primary diagnostic tool for evaluating cubital tunnel syndrome. Dynamic maneuvers performed during ultrasound examinations can identifying specific nerve pathologies and by observing the ulnar nerve as the patient moves their elbow or forearm, clinicians can detect occurrences such as nerve subluxation, dislocation, or snapping over the medial epicondyle.
Poor posture involvement and cell phones
A March 2026 study in the Journal of Clinical Medicine (2) found with the widespread adoption of smartphones, poor and sustained upper-limb postures are risk factors for ulnar nerve compression. This retrospective study investigated the potential correlation between smartphone use patterns and the development of Cubital tunnel syndrome.
A retrospective observational study was conducted on 50 patients with EMG-confirmed cubital tunnel syndrome who underwent surgical decompression and 50 matched controls.
The researchers found smartphone use may contribute to ulnar nerve compression primarily through ergonomically disadvantageous postures, particularly sustained elbow flexion, rather than total usage time. These findings highlight a modifiable behavioral risk factor relevant to the rising prevalence of Cubital tunnel syndrome.
References
1 Cosentino A, Carlier Y, Rennie WJ, Pesquer L. Ultrasound evaluation of the ulnar nerve in cubital tunnel syndrome: anatomy, normal and abnormal findings, and postoperative aspects. Journal of ultrasonography. 2026 Mar 13;26(104):20260002. [Google Scholar]
2 Vavalle G, Barbieri C, Messina D, Pietramala S, Rocchi L, Fulchignoni C. The Correlation Between Smartphone Use and Compressive Ulnar Neuropathy at the Elbow: A Retrospective Study. Journal of Clinical Medicine. 2026 Mar 5;15(5):2004. [Google Scholar]