Hi,
The complications of injections manifest almost immediately and not after 3-4 months. There could be other causes of cramps in hands. Please go for MRI of hand and spine to rule out nerve compression. Other causes of cramps could be electrolyte imbalance, vitamin deficiency and poor blood circulation. Please consult a physician and neurologist for diagnosis and treatment. Hope this helps you. Take care and regards!
A single localized steroidal injection in the hand should have no significant side effects.