When a 38-year-old man presented with pain, weakness and numbness in his left arm, neurosurgeon Shih-Chun “David” Lin knew it was largely caused by issues in the patient’s cervical spine, most notably a herniated disk between the C6 and C7 vertebrae.
An electromyogram performed by neurologist Omid Motabar showed cervical radiculopathy from the disk herniation, and an MRI showed problems in several spots along the cervical spine. Some of those issues were due to the patient playing sports his entire life, including many years of boxing, which had led to shoulder dislocations and rotator cuff surgery. Without surgery, the patient risked permanent pain, weakness and numbness in his left arm.
Rather than anterior cervical diskectomy and fusion — the standard treatment — Lin performed a minimally invasive artificial cervical disk replacement between the C6 and C7 vertebrae. This outpatient procedure preserves a patient’s range of motion and promotes faster recovery. In this case, the patient felt his issues resolve almost immediately after surgery, and he was back in the gym working out within two weeks.
“Medical studies repeatedly show that the outcomes of artificial disk replacement are equivalent to those of fusion and, in some cases, superior to fusion,” says Lin, chief of neurosurgery at Suburban Hospital. “But artificial disk replacement offers a number of advantages over fusion.”
Those advantages include the ability for doctors to preserve range of motion and prescribe anti-inflammatory medications rather than narcotics after surgery (anti-inflammatories slow down bone healing in fusion surgery). After surgery, patients do not need to wear a cervical collar, have less postoperative pain and run a lower risk of developing narcotics dependence.
The best candidates for artificial cervical disk replacement are patients whose spines are anatomically intact rather than distorted. Fusion remains the more commonly performed procedure, even in Lin’s practice, because fewer patients qualify for artificial cervical disk replacement.
This particular patient had enough space between his vertebrae to allow for artificial disk replacement rather than fusion, which Lin says is one of the biggest factors in determining patient eligibility. The other issues in the patient’s cervical spine, while milder, also favored using artificial disk replacement, as fusion has a higher risk of worsening issues in other vertebrae.
One important metric of comparing cervical disk replacement and fusion is the risk of reoperation, which is present in both procedures.
Reoperation risks are equal, at about 10%, for artificial disk replacement and fusion when the procedures are done at one level. However, reoperating on an artificial disk involves fixing the same level, whereas reoperating on a fusion surgery requires fusing an additional level of vertebrae, further restricting motion. In other words, reoperation in fusion can lead to a cascading effect of fusing more and more vertebrae.
For two-level surgeries, artificial disk replacement has been shown to be superior to fusion in a number of ways, including less postoperative discomfort, lower complication rates and lower reoperation risks.
Treatment for Herniated Lumbar Disks
Lin and his neurosurgery colleagues also perform minimally invasive microdiskectomies for patients with herniated disks in the lumbar spine. Like artificial cervical disk replacement, this outpatient procedure also involves making a smaller incision for surgery, which promotes faster healing and reduces postoperative pain.
In microdiskectomies, an incision about a half-inch long is made, and X-ray is used to identify the right spot in the spine. A series of tubes that gradually get wider are used to stretch the tissue and access the part of a disk that is bulging and/or the area of the spine where bone spurs need to be removed. This method is used instead of opening up larger areas of tissue as done in the more traditional approach, which potentially increases infection risk and could result in a longer recovery period, although infection risk still remains low.
While many patients with bulging disks can heal with nonsurgical interventions, those who have neurologic deficits such as muscle weakness or numbness that can be confirmed via MRI are good candidates for microdiskectomy.
“Recovery is highly individual, but a lot of people don’t take pain medicine at all,” Lin says. “Sciatic pain relief tends to be immediate.”
The neurosurgery team at Suburban Hospital also includes neurosurgical spine specialist Louis Chang and neurosurgeon Youssef Comair, an internationally recognized surgeon who pioneered awake craniometries.