Surgery of Spinal DeformitiesRizzoli Orthopaedic Institute

Bologna, Italy

Surgical options in progressive

scoliosis in pediatric patients with

Neurofibromatosis type I

Konstantinos Martikos, Francesco Lolli, Mario Di Silvestre MD,

Alfredo Cioni, Stefano Giacomini, Mauro Spina,

Tiziana Greggi,

Background Spinal deformity

Spinal deformity in approximately 49% of patients with NF1 (1)

2 types of scoliosis in NF1Non-dystrophic progressession similar to

AIS treated as an AISDystrophic (2) more severe osseous abnormalities

that complicate treatment early and aggressive

surgical intervention is necessary

Dural ectasia bone erosion meningocele

Vertebral scalloping <3mm thoracic

spine <4mm in lumbar spine

Background Dystrophic alterations

Rib Penciling may cause

paralysisDumbbell lesion canalar

neurofibromas expand through

foramen

Orthopedic features

Modulation

a process by which dystrophic characteristics develop over time (3)

C. S. Female5 yrs

C. S. Female10 yrs

Modulation should be carefully assessed to prevent progression of deformity in young patients under the age of 10 years.

Modulation rate is reported 65%; Occures in 81% of NF-1 patients

with scoliosis before the age of 7.

Retrospective evaluation of surgical outcomes 23 consecutive patients, between 4 and 11 years,

with severe progressive scoliosis in NF1. Average Cobb angle before surgery: 48° (min. 38°,

max. 82°) Skeletal maturity according to Risser sign was 0 in all

patients. Mean age at first surgical procedure: 9.1 years (min.

8 yrs, max. 11yrs) Mean follow up: 4 years (min. 18 mos, max 15 yrs).

Materials and methods

Group A (14 patients): Thoracic kyphosis inferior to 50°. Posterior only instrumentation.

Group B (9 patients): Thoracic kyphosis superior to 50°. Combined anterior and posterior instrumented arthrodesis.

Patients retrospectively divided into 2 Groups

Average correction rate of Cobb angle: 60%.

Overall complication rate: 24%.

Major complication rate was 7%.

Crankshaft phenomenon observed in 3 Group A patients (21%);

in these cases anterior arthrodesis was performed after a mean 15 mos period from first surgical procedure.

Fusion failure observed in 1 Group B patient, treated by revision of posterior instrumentation.

Clinical and radiographic evaluation at follow up showed good outcome in terms of deformity progression and quality of life.

Results

Patient M. M. Female

21-07-19962004, age 8

right convex thoracic scoliosis with hyperkyphosis

highly dystrophic

Patient M. B. Female

21-07-19962005, age

9

Combined anterior and posterior arthrodesis with autologus bone graft

2009, age 13

4-year follow-up

Patient M. M. Female

21-07-19962011, age 15

6-year follow-up

In highly dystrophic progressive deformities in pediatric age: early arthrodesis should be performed early approach should be aggressive (anterior and

posterior fusion)

Posterior access

Anterior access

Conclusions

Surgical treatment of early progressive spinal deformities in NF1 is a demanding procedure with un uncertain outcome

Revision surgery may be necessary due to the ongoing dystrophic alterations that may occur over time (modulation).

Conclusions

13-year-old male:double-access arthrodesis with anterior fibular graft

21 years follow up:erosion spares only anterior bone graft

None of the authors has any potential conflict of interest