Normally, a slipped disk is not caused by an accident. Some are, however.
Most slipped disks disappear in time without treatment. They cause pain for 6-12 weeks, which is best treated with standard pain medication. Prescriptions through your general physician. In some cases, there is a neurological deficit like paralysis or incontinence. If so, this should be addressed by a neurosurgeon. If there is no or minimal neurology, there is no reason to operate on your mother.
I hope I have informed you to your satisfaction,
Met vriendelijke groet,
Dr. R.H.G.P. van Erve, orthopedisch chirurg
First of all, sorry for the late response. To me these type of complaints seem to be anterior knee pain, most likely to be incurred by the knee cap. Do you remember whether these painful nights follow day in which you were more active or more sitting on your knees, having them flexed? The knee cap is particularly at your age vulnerable to long standing compression, which induces a sore spot there. You could compare it to a bruise. It is nothing to be afraid of and it will disappear in time. Although it could last for several years. If it occurs again, just try to move your knee a little, take some painkillers and go on living, for it is not harmful, it just hurts.
I hope you appreciate my answer.