A laminoforaminotomy (posterior foraminotomy) can be a good surgery for the right condition. A cervical nerve root that is trapped by a disc hernation can be decompressed by this procedure without the need for a fusion. The herniation has to be accessible by this approach meaning that if the herniation also extends under the spinal cord, in my opinion, there would be too much manipulation of the cord to allow access the hernation to allow a safe decompression.
This procedure works less well if the compression is caused by a bone spur which is a common finding. See the section under “cervical-radiculopathy” to understand the difference. Accessing and removing the bone spur from the back of the spine (which is the laminoforaminotomy approach) is very difficult and requires significant manipulation of the nerve root. This can leave more numbness and pins/needles after the surgery than before.
I assume the surgeon found this bone spur compressing the nerve root and decided after some attempts that it was better to leave this spur than to try and remove it but possibly injuring the nerve more. This was a good decision on his or her part. There are times that a successful surgery cannot be completed without further danger to the root.
The most appropriate treatment if the symptoms have not improved (especially with continued weakness) is to consider an ACDF surgery (anterior cervical decompression and fusion). This procedure will remove the bone spur and free up the nerve root allowing the best chance for nerve root recovery.