Spinal cord tethering following myelomeningocele repair

Object. Symptom response to spinal cord untethering, and the impact of duraplasty and scoliosis on retethering, are poorly understood in tethering after myelomeningocele (MMC) repair. In this retrospective study, the authors examined the outcomes of children who developed first-time spinal cord tethering following MMC repair. The response of symptoms to untethering and the role of duraplasty and scoliosis in retethering are explored. Methods. The authors performed a review of 54 children with first-time symptomatic spinal cord tethering following MMC repair to determine the impact of untethering on symptoms, the impact of dural repair type on retethering, and the role of scoliosis on the prevalence and time to retethering. Results. The average patient age was 10.3 ± 4.9 years, and 44% were males. The most common presenting symptoms of tethered cord syndrome were urinary (87%), motor (80%), gait (78%), and sensory (61%) dysfunction. The average postoperative time to symptom improvement was 2.02 months for sensory symptoms, 3.21 months for pain, 3.50 months for urinary symptoms, and 4.48 months for motor symptoms, with sensory improvement occurring significantly earlier than motor improvement (p = 0.02). At last follow-up (an average of 47 months), motor symptoms were improved in 26%, maintained in 62%, and worsened in 11%; for sensory symptoms, these rates were 26%, 71%, and 3%, respectively; for pain, 28%, 65%, and 7%, respectively; and for urinary symptoms, 17%, 76%, and 7%, respectively. There was no difference in symptom response with type of dural repair (primary closure vs duraplasty). Symptomatic retethering occurred in 17 (31%) of 54 patients, but duration of symptoms, age at surgery, and type of dural repair were not associated with retethering. Scoliosis was not associated with an increased prevalence of retethering, but was associated with significantly earlier retethering (32.5 vs 61.1 months; p = 0.042) in patients who underwent additional untethering operations. Conclusions. Symptomatic retethering is a common event after MMC repair. In the authors’ experience, sensory improvements occur sooner than motor improvements following initial untethering. Symptom response rates were not altered by type of dural closure. Scoliosis was associated with significantly earlier retethering and should be kept in mind when caring for individuals who have had previous MMC repair. (DOI: 10.3171/2010.8.PEDS09491)