[Classification and microsurgical treatment of primary tethered cord syndrome in adults]

To summarize the clinical manifestation, classification, and experience of surgical treatment of primary tethered cord syndrome (TCS) in adults.

The authors retrospectively analyzed a series of 171 adult patients with primary TCS who were surgically treated under microscope from March 2007 to October 2019. There were 61 males and 110 females whose ages were 18-65 years, with an average age of (39.02±11.81) years. Clinically, the patients presented with various neurological symptoms and signs including lower back and legs pain, reflex changes, sensory disturbances, muscle weakness, and sphincter problems. They were divided into 5 types by clinical manifestations and neuro-imaging features: (1) filum terminale traction in 69 cases, (2) split cord malformation in 21 cases, (3) myelomeningocele in 20 cases, (4) lipomyelomeningocele in 36 cases, and (5) dermal sinus traction in 25 cases. All the patients underwent microsurgery to untether the spinal cord. The patients kept prone position 7 days postoperatively. The Kirollos grading was used to evaluate the outcome of intraoperative untethering. The visual analogue scale (VAS) was used to evaluate the pain, the score of critical muscle strength was used to evaluate the lower extremity motor function, and the Japanese Orthopaedic Association (JOA) sphincter function score was used to evaluate the bladder function.

All of the 171 patients were treated with microsurgery to release the adhesion and cut off the filum terminalis. 61 cases of them received resection of the lesions according to the etiology. All the tethered spinal cord reached Kirollos grade Ⅰ untethering and the dural sac was reconstructed. Other than 5 patients had cerebrospinal fluid leakage and incision laceration and underwent re-suture, there was no surgical complication. The local pain was relieved, the lower limbs weakness or bowel and bladder dysfunction gradually recovered postoperatively. The period of follow-up ranged from 6 months to 12.5 years with an average of (5.62±2.31) years. The neurological function was improved in 153 cases and stable in 18 cases. There was no recurrence of tethered cord be found during the follow-up period.

The primary TCS in adulthood could be classified into 5 types by clinical manifestations and neuro-imaging features and surgical treatment should be undertaken in regard to the classifications including dissection and resection of the lesion detethering the spinal cord and reconstruction of the dura sac under microscope. The outcome of surgical treatment is satisfactory.