Anatomical Variations of the Lumbrical Muscles Causing Carpal Tunnel Syndrome
- Author:
BENNY E
1
Author Information
1. Hand and Microsurgery Unit, Department of Orthopaedics and Traumatology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia.
- Collective Name:BENNY E; PARMINDER GS; NUR AZUATUL AK; TAN JA; AHMAD SUPARNO B; JAMARI S; SHALIMAR A
- Publication Type:Case Reports
- Keywords:
anatomical;
carpal tunnel syndrome;
hypertrophy;
lumbrical;
median nerve;
muscle;
variations
- From:Medicine and Health
2019;14(1):197-202
- CountryMalaysia
- Language:English
-
Abstract:
Many anatomical variations exist in and around the carpal tunnel. However,
symptomatic anomalies causing carpal tunnel syndrome is rare. Additionally,
carpal tunnel surgery is considered a simple operation commonly done by junior
surgeons who are usually unaware of variations resulting in unfavorable surgical
outcomes. We highlight a case of lumbrical muscle variation causing carpal tunnel
syndrome. A 73-year-old male presented with numbness and pain of both hands
associated with abnormal fullness over both wrists and distal forearms. Initially the
right hand was numb and subsequently a year later, the left hand became numb.
Physical examination was positive for Durkan, Phalen and Tinel signs at the carpal
tunnel. Magnetic Resonance Imaging (MRI) showed abnormal muscle tissues in
the carpal tunnel. During the carpal tunnel release and exploratory surgery, we
noted an abnormally proximal origin of the lumbrical muscles in the forearm rather
than the typical palmar origin. He also had lumbrical muscle hypertrophy in the
left side. These two factors resulted in overcrowding within the carpal tunnel. Postoperatively the patient recovered well with pain relief and gradual improvement of
his numbness. Variations in the anatomy of the lumbrical muscles is not uncommon
and may result in carpal tunnel syndrome. Hence, carpal tunnel release surgeries
may not be as straight forward as expected and surgeons should be aware of this
possibility.
- Full text:12.2019my0106.pdf
