According to your 'brief' history, I am assuming that you had spinal cord injury due to the accident. It would be better if you have given some more details such as, when did the accident happen? The exact location of the injury, any surgery happened or are you still on medication? Nonetheless, I will try my best to give you clarification on your query.
The spinal cord injury can be very extreme and the physical condition can deteriorate over the period of time. From the brain, the spinal cord will travel down to the hip area through a column of bones called vertebrae. It will supply its nerves to various body parts which branch out from the main cord into the hands, thorax, abdomen, pelvic area and legs. If there is any injury to the vertebra or the spine itself, there will be compression of the spinal cord or permanent damage which will restrict the passage of information between the nervous tissue (spinal cord) and to the organs it supplies. Depending on the location and the degree of injury, the symptoms may vary.
Since you are saying that you are experiencing numbness in hands and legs, I am assuming that the injury has happened to cervical (C6, C7, and C8) vertebrae as well as the condition called Sciatica. The numbness in hands can be attributed to damage or compression of the spinal cord in C6, C&, or C8 areas whereas extreme lower back pain and numbness in legs is attributed to damage or compression to Sciatic nerve. So if you are experiencing any nervous symptom in the upper body part, the nerve involved might be in the cervical area. Injury or compression of the nerve in the thoracic and lumbar area will not cause symptoms in upper extremities i.e, hands.
Irrespective of the damage or location, you must meet a neurologist (not the neurosurgeon) and take his opinion. Generally, the progressive symptoms will become worse if not treated properly. Since you have the history of trauma (accident) I don't know why your doctor has advised HLA B-27 Antigen typing test. This test is generally done in order to diagnose the cause of pain and other symptoms when there is no history of trauma or infection.
Coming to your MRI report, you said there is degeneration. It would have been better if you have specified the exact location of the degeneration. According to your query, I am assuming that you are having a herniated disc which is the cause of pain in your lower back.
Whatever might be the condition, in layman terms the pain you are experiencing in various body parts due to spinal injury is called as 'stalking and glove', technically called paresthesias and pain. If you are not having this pain before the accident, It would be fair to assume that you are not having metabolic neuropathies (like hypothyroidism), malabsorption neuropathies (like Vitamin B12 deficiency), infectious neuropathies (like Lyme disease), inflammatory neuropathies (like Systemic Lupus Erythematosus) and substance abuse neuropathies (like alcoholism). The treatment will be broadly in three ways:
1. Physical activity may help you a lot. Most patients will respond to this non - surgical method. Learn to strengthen your back. Maintain appropriate posture and weight. Do physical exercises that will relieve the back pain. You can consult a physiotherapist and can take the opinion.
2. The majority painkillers used to relieve nerve pain are called as Non-Steroidal Anti Inflammatory Drugs (NSAIDS). Sometimes local injections which include steroids can also be given.
3. Surgical intervention is done only if the condition does not improve with the above two methods or else if the condition worsens further.
So I would suggest you not to worry and meet neurologist in your area. Take the opinion of orthopaedician as well. Most patients will live full form of life after heavy spinal injuries. You are young, 22 years, you will recover rapidly if you follow a healthy lifestyle. You can follow the link below which explains in detail about the back pain.
Dr. V. Shashikanth