SBA Answers and Explanations
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury in SBAs for the MRCS Part A, 2018
Since the carpal tunnel exists as a confined space, entrapment of the median nerve may occur within it. This is commonly due to a build-up of fluid within the carpal tunnel, or because of hypertrophy of the bones/ligaments/tendons that surround, or are contained within, the carpal tunnel. Compression of the median nerve within the carpal tunnel is known as carpal tunnel syndrome. Note this is different from cubital tunnel syndrome, which refers to compression of the ulnar nerve behind the medial epicondyle at the elbow. The ulnar artery and nerve do not pass through the carpal tunnel, but instead pass superficial to the carpal tunnel in their own fibro-osseous tunnel commonly given the name Guyon’s canal. The ulnar nerve and artery are therefore unaffected in carpal tunnel syndrome.
Test Paper 1
Teck Yew Chin, Susan Cheng Shelmerdine, Akash Ganguly, Chinedum Anosike in Get Through, 2017
Cubital tunnel syndrome is the most common entrapment neuropathy of the elbow. It is seen in throwing sports, tennis and volleyball. Traction injuries to the ulnar nerve can occur secondary to the dynamic valgus forces. Compression of the ulnar nerve within the cubital tunnel occur secondary to direct trauma, repetitive stresses, or replacement of the overlying retinaculum with an anomalous anconeus epitrochlearis muscle. Recurrent subluxation of the nerve due to acquired laxity from repetitive stress or trauma can lead to friction neuritis. Finally, osseous spurring within the ulnar groove caused by overuse and posteromedial impingement in throwers can cause nerve irritation. Ulnar nerve thickening and increased T2-weighted signal are typical MRI features. Oedema-like signal changes or atrophy of the flexor carpi ulnaris and flexor digitorum profundus muscles may also be secondary to ulnar neuropathy.
Diabetic Neuropathy
Jahangir Moini, Matthew Adams, Anthony LoGalbo in Complications of Diabetes Mellitus, 2022
Carpal tunnel syndrome may be unilateral or bilateral and is caused by compression of the median nerve within the volar aspect of the wrist. This is between the transverse superficial carpal ligament and the flexor tendons of the muscles of the forearm muscles. Risk factors include diabetes mellitus, pregnancy, rheumatoid arthritis, repeated forceful movements with the wrist extended, and possibly, use of a poorly positioned computer keyboard. Most cases are idiopathic. Peroneal nerve palsy is usually caused by compression of the peroneal nerve against the lateral aspect of the neck of the fibula. Risk factors for peroneal nerve palsy include obesity and fibular head fracture. Radial nerve palsy is also known as Saturday night palsy, and is due to compression of the radial nerve against the humerus, such as when the arm is laid over the back portion of a chair for a long period of time – often during deep sleep or because of intoxication. Risk factors for radial nerve palsy include the male gender, jobs that require repetitive motion, or awkward postures or positions, and injuries to the bones and joints. Ulnar nerve palsy, near the elbow, is usually caused by trauma to the nerve within the ulnar groove, from leaning repeatedly on the elbow. It is also caused by asymmetric bone growth after a childhood fracture has occurs – known as tardy ulnar palsy. The ulnar nerve may be compressed along its length, under the medial epicondyle, through the tissues of the cubital tunnel. This sometimes results in cubital tunnel syndrome. Risk factors for ulnar nerve palsy include smoking, male gender, elbow fracture or subluxation, obesity, excessive alcohol consumption, repetitive arm motions, diabetes mellitus, and hypertension.
Effect of dry needling on cubital tunnel syndrome: Three case reports
Published in Physiotherapy Theory and Practice, 2019
Sudarshan Anandkumar, Murugavel Manivasagam
Peripheral nerve entrapments typically occur at mechanical interfaces in the upper extremity. The most common entrapment is of the median nerve at the carpal tunnel (Ibrahim, Khan, Goddard, and Smitham, 2012). Ulnar nerve entrapment is the second most common entrapment neuropathy and may occur at the wrist, thoracic outlet, or elbow (Elhassan and Steinmann, 2007). In the elbow, ulnar nerve entrapment occurs at the cubital tunnel and was described as “cubital tunnel syndrome” cubital tunnel syndrome by Feindel and Stratford in 1958 (Wojewnik and Bindra, 2009). Other nomenclatures that have previously been used to describe this entrapment are “ulnar nerve entrapment syndrome,” “sulcus ulnaris syndrome,” and “tardive ulnar neuritis” (Assmus, Antoniadis, and Bischoff, 2015; Qing et al., 2014).
Superior sulcus tumor disguised as cervical radiculopathy with metastasis to brachial plexus
Published in Baylor University Medical Center Proceedings, 2019
James Rizkalla, Seagal Dauglas, Scott Nimmons, Waleed El-Feky, Ishaq Syed
A 74-year-old man, a former smoker, was referred to a spinal orthopedic surgeon for evaluation of his neck pain that frequently radiated down into his left arm, with maximal pain in the axilla, arm, and forearm. The pain was chronic, had progressively worsened, and was described as intermittent, moderate, stabbing, throbbing, and aching. Resting the limb, acetaminophen, and topical anti-inflammatory gel provided minimal relief. The patient was known to have arthritis, atrial fibrillation, previous hernia surgeries, and left rotator cuff injury. Other orthopedic surgeons told him that he had cubital tunnel syndrome, and he underwent an ulnar release on the left side in an attempt to alleviate his symptoms, without success.
‘Bony’ cubital tunnel syndrome caused by heterotopic ossification
Published in British Journal of Neurosurgery, 2019
Cubital tunnel syndrome (CuTS) is an injury of the elbow ulnar nerve mainly caused by ischaemia or compression. Compression may be direct, or involve repeated flexion and extension of the elbow, traumatic scars, or ectopic muscle.1 Patients with severe burns, traumas, traumatic brain injuries, or other disorders causing heterotopic ossification should undergo an early auxiliary examination to observe bony hyperplasia development in the elbow joint, and nerve decompression surgery if required.
Related Knowledge Centers
- Ulnar Nerve
- Peripheral Neuropathy
- Ulnar Claw
- Froment'S Sign
- Ultrasound
- Magnetic Resonance Imaging
- Carpal Tunnel Syndrome
- Radial Nerve
- Thoracic Outlet Syndrome
- Cervical Vertebrae