From the Research
Claw hand, also known as intrinsic minus hand, is a deformity characterized by hyperextension of the metacarpophalangeal joints and flexion of the interphalangeal joints, resulting in a claw-like appearance of the hand, typically caused by ulnar nerve damage, as seen in a recent study 1. The pathology of claw hand involves denervation of the intrinsic hand muscles, particularly the interossei and lumbricals, while the extrinsic flexors and extensors remain intact, creating an imbalance that produces the characteristic posture. This condition can result from various causes, including ulnar nerve damage, lower brachial plexus injury, or cervical spinal cord lesions. Some key points to consider in the pathology of claw hand include:
- Ulnar nerve injury can induce chronic neuropathic pain and is frequently devastating due to loss of cupping the hand around objects and diminished grip strength, as noted in a study published in 2023 1.
- The deformity is characterized by metacarpophalangeal hyperextension and interphalangeal flexion, making it impossible to oppose the fingers and thumb, as described in a study from 2022 2.
- Early intervention is crucial as longstanding cases may lead to joint contractures and muscle atrophy, highlighting the importance of prompt treatment, as discussed in a study from 2015 3.
- Patients should be evaluated for associated sensory deficits and weakness in other muscle groups to determine the exact level of nerve injury, as emphasized in a study from 2017 4.
- Recent advances in treatment options, such as peripheral nerve stimulation, have shown promising results in managing ulnar neuropathic pain, as reported in a 2023 case study 5.