Numbness and tingling after surgery are indicators of a type of nerve problem in your foot after surgery. There are different types of “injuries” that can occur during surgery to the nerves in your ankle.
One of the reasons for the numbness and tingling and potential nerve injury is the small size of the ankle coupled with a large nerve supply due to the increased amount of muscles in the area.
There are two different types of nerves in your limbs. Motor, which make you move, and sensory, which make you feel. When motor nerves are damaged, you are unable to move the muscle it innervates. Innervates is a fancy word for supplies.
When a sensory nerve is damaged, you experience the numbness and tingling. You may also experience “hypersensitivity” which means when the area is touched you feel an intense pain or sensation.
In this article, we will talk about the different types of nerve injury, how you could potentially have nerve damage after surgery, how nerves can regenerate, and how physical therapy can help with this whole process.
What are the three different types of nerve injury?
There are three different levels of nerve injury(3). The first type of injury is called a neuropraxia. This is when the nerve signals are slowed or blocked. This is a temporary injury and recovery is usually complete(3).
Axonotmesis is when there is loss of nerve continuity, but the supportive connective tissues stay intact. There may be degeneration of the nerve below the spot of injury. Recovery is generally incomplete, and, in some cases, surgery is required(3).
The most severe type of nerve injury is neurotmesis which is a complete severance of the nerve fiber and connective tissue(3). Surgery is generally indicated in this type of nerve injury.
What are three nerves potentially responsible for numbness and tingling in the foot after surgery?
In general, sensory nerves are damaged in ankle surgery as opposed to motor nerves(9). There are three nerves that are the most commonly damaged: sural nerve, superficial peroneal nerve, and the plantar medial cutaneous nerve(9).
The sural nerve supplies the back of your calf, lateral (outside) aspect of your heel, and bottom and lateral side of your foot.
Superficial peroneal nerve
The superficial peroneal nerve, also known as the superficial fibular nerve, supplies the front of your lower leg (shin), top of your foot, and most of your toes.
Plantar medial cutaneous nerve
Lastly, the plantar medial cutaneous nerve supplies most of the bottom of your foot. The nerve may be damaged a few ways.
How can these nerves be damaged during surgery?
First, a nerve block or anesthesia may cause very temporary numbness and tingling. This should resolve shortly after surgery. The nerve may be cut when the incision is made or could be bruised or entrapped when the surgeon applies sutures(9).
The nerve may be stretched too far when the tissues are being held open, this is called a traction injury(8).
Another mechanism of injury found is mechanical stress on a nerve. This means that the way you were positioned during surgery may have placed unwanted stress on the nerve causing the numbness and tingling(1).
There are also extrinsic factors that could cause numbness and tingling after surgery. For example, if the dressing/wraps are too tight after surgery this could occlude the nerve and cause the numbness.
Likewise, if you were instructed to wear a boot and it does not fit properly this could cause numbness and tingling. It is important to address these extrinsic factors right away because they are easily solved and will not cause permanent damaged when attended to.
If the nerve is directly damaged, there is a chance a neuroma can occur. A neuroma is a benign growth of nerve tissue, generally between the third and fourth toe. You may experience pain, burning, and numbness and tingling(3,2).
It is very important to note that if you are having serious problems such as hypersensitivity, lack of ability to move muscles in your foot, or numbness and tingling that interrupts your daily life, you must speak to your surgeon right away. With your operating doctor you can develop and discuss a plan to address the issue.
Can these damaged nerves recover?
The good news is that with most types of nerve injuries that don’t need surgical intervention, recovery is possible. Studies show that function of the nerve is restored in most patients within six months(9). Patients were still seeing improvements at nine months and one year post surgery in cases that did not recover within the six months(9).
If a nerve is bruised or traumatized, but not cut the average time frame for recovery is 6-12 weeks(7). If a nerve is cut during surgery, the nerve has potential to regenerate 1mm per day(7,3). It is found that cut nerves lay dormant for about 4 weeks until they start to regenerate (7).
Other factors that affect recovery of the nerve is the age and motivation of the patient(3). In an older individual, healing is naturally delayed due to the aging process. If there is an excess amount of scar tissue around the nerve, this will also inhibit recovery.
Lastly, if a motor nerve is damaged it has a decreased chance of recovery over a sensory nerve(7). Motor nerves have been showed to require repair within 12-18 months after injury to stop the nerve from dying and no longer sending signals to the muscle which it innervates(7).
Physical therapy can be very helpful in the rehabilitation process of a damaged nerve. Not only right away but when the damage and surgery becomes chronic, even up to one year and beyond surgery.
How can a physical therapist help you?
First, let’s talk about the evaluation of the nerve damage. Your physical therapist can be helpful in many ways. Not only can they help you determine if there is actual nerve damage, but they can provide treatments which will aid in the healing and regeneration of the nerve.
To begin with, your therapist will examine you to get a better idea of your symptoms. They will check your sensation, coordination, and muscle strength. The therapist will also ask about your pain, check the condition of your skin, and make sure your joints are not too stiff.
They will also assess if you have balance and functional deficits. Functional deficits include the inability to perform everyday tasks which will affect your quality of life due to the nerve injury (6).
During the acute phase, your physical therapist can help with ensuring you are mobilized or immobilized correctly. The PT will check that you have the proper splint or brace, that it fits properly, and that you understand how to protect the affected foot and ankle (3).
During the subacute, or recovery phase of the injury your physical therapist will help you perform desensitization and motor retraining. Yup, that’s right, this is when your home exercises will begin.
You know every good PT prescribes and HEP, right? Your therapist may also prescribe other forms of treatment including manual therapy, ultrasound, and electrical stimulation to help the nerve regenerate (6,4).
During the chronic phase of your recovery, physical therapist will continue to help you with not only the rehabilitation of your foot and ankle after surgery but also in dealing with the damaged nerve.
During this phase, your PT will help to guide you in how to modify your daily life to ensure the utmost independence and quality of life. Your physical therapist will assist you in confirming you have the proper foot wear, the proper bracing if necessary, and the correct assistive devices for your level of function.
Throughout your treatment, the PT will provide you with techniques to reduce sensitivity including tapping, pinching, and brushing. If you present with balance and coordination deficits, your physical therapist will be sure to assist you in activities that will challenge these deficits.
The PT is trained to “grade” these activities which will get harder as you get better at them. Other adjunct therapies your PT might utilize are yoga and tai chi to help with improving proprioception(6).
Proprioception is the part of balance which helps your nerves tell where you are in space. With nerve injury and even after surgery, proprioception can become damaged. Your physical therapist is armed with an entire arsenal of treatments to ensure you get back on your feet (pun intended) and remain as mobile as possible.
It is the PTs specialty to work with the surgeons following their protocol to not only ensure your ankle rehabilitates to its fullest potential, but also, they are highly trained in helping with neurological issues as well. As with any injury or surgery, it is very important you commit to the plan and give 100%. With full commitment to your recovery you will see the best results.