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European Spine Journal

, Volume 24, Issue 7, pp 1502–1509 | Cite as

Migration of the penetrated rib head following deformity correction surgery without rib head excision in dystrophic scoliosis secondary to type 1 Neurofibromatosis

  • Saihu Mao
  • Benlong Shi
  • Shoufeng Wang
  • Chengyue Zhu
  • Zezhang Zhu
  • Bangping Qian
  • Feng Zhu
  • Xu Sun
  • Zhen Liu
  • Yong Qiu
Original Article

Abstract

Purpose

Dystrophic scoliosis secondary to Neurofibromatosis type 1 (NF1) may predispose to rib penetration into the spinal canal. No clear consensus was established regarding whether or not to resect the compressing rib head during correction maneuvers. The purpose of this study was to present imaging quantification of the migration of intraspinal-dislocated rib head in order to assess the extraction degree of dislocated rib heads and the associated influencing factors.

Methods

Imaging data of NF1 scoliotic patients with intraspinal rib head dislocation from March 1998 to April 2014 were retrospectively reviewed. The location and migration of the rib head were evaluated in a spinal canal-based coordinate system to calculate their pre- and postoperative vector coordinates. Differences in multiple parameters representative of rib head position were compared by paired sample t test. We also explored whether correction of vertebral rotation and translation could contribute to the extraction of intra-canal rib head by linear regression analysis.

Results

The incidence of apical convex rib head penetration into the canal was 15.9 % (23/145). Only 14.8 % of the dislocated rib heads invaded into the concave half-circle of the spinal canal, which was reduced to 3.7 % postoperatively. The directions of rib head migration were mostly toward the anterior convex quadrant of the spinal canal (70.4 %). Paired sample t tests revealed significant reduction in intraspinal rib length (9.2 ± 3.6 vs. 5.2 ± 3.6 mm, p < 0.001) and improvement in distance between the rib head tip and the most concave spot of the spinal canal (DRCSSC) (14.2 ± 2.6 vs. 18.1 ± 3.3 mm, p < 0.001). Change of rib-vertebrae angle (RVA) was demonstrated to be positively correlated with reduction in intraspinal rib length (β = 0.534, p = 0.004), while Change of RVA (β = −0.460, p = 0.008) and vertebral translation (VT) (β = −0.381, p = 0.024) was negatively correlated with change of DRCSSC.

Conclusions

Spontaneous migration of the dislocated rib head following posterior correction surgery resulted in shorter intraspinal rib length and larger uninvaded area. More correction of vertebral translation and rib-vertebrae angle could increase the degree of extraction from the spinal canal immediately after the surgery.

Keywords

Neurofibromatosis Rib head penetration Migration 

Notes

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (81301603).

Conflict of interest

None.

References

  1. 1.
    Vitale MG, Guha A, Skaggs DL (2002) Orthopaedic manifestations of neurofibromatosis in children: an update. Clin Orthop Relat Res 401:107–118PubMedCrossRefGoogle Scholar
  2. 2.
    Deguchi M, Kawakami N, Saito H, Arao K, Mimatsu K, Iwata H (1995) Paraparesis after rib penetration of the spinal canal in neurofibromatous scoliosis. J Spinal Disord 8:363–367PubMedGoogle Scholar
  3. 3.
    Flood BM, Butt WP, Dickson RA (1986) Rib penetration of the intervertebral foraminae in neurofibromatosis. Spine 11:172–174PubMedCrossRefGoogle Scholar
  4. 4.
    Khoshhal KI, Ellis RD (2000) Paraparesis after posterior spinal fusion in neurofibromatosis secondary to rib displacement: case report and literature review. J Pediatr Orthop 20:799–801PubMedCrossRefGoogle Scholar
  5. 5.
    Mukhtar IA, Letts M, Kontio K (2005) Spinal cord impingement by a displaced rib in scoliosis due to neurofibromatosis. Can J Surg J Can de chirurgie 48:414–415Google Scholar
  6. 6.
    Gkiokas A, Hadzimichalis S, Vasiliadis E, Katsalouli M, Kannas G (2006) Painful rib hump: a new clinical sign for detecting intraspinal rib displacement in scoliosis due to neurofibromatosis. Scoliosis 1:10. doi: 10.1186/1748-7161-1-10 PubMedCentralPubMedCrossRefGoogle Scholar
  7. 7.
    Abdulian MH, Liu RW, Son-Hing JP, Thompson GH, Armstrong DG (2011) Double rib penetration of the spinal canal in a patient with neurofibromatosis. J Pediatr Orthop 31:6–10. doi: 10.1097/BPO.0b013e3182032029 PubMedCrossRefGoogle Scholar
  8. 8.
    Yalcin N, Bar-on E, Yazici M (2008) Impingement of spinal cord by dislocated rib in dystrophic scoliosis secondary to neurofibromatosis type 1: radiological signs and management strategies. Spine 33:E881–E886. doi: 10.1097/BRS.0b013e318184efad PubMedCrossRefGoogle Scholar
  9. 9.
    Sun D, Dai F, Liu YY, Xu JZ (2013) Posterior-only spinal fusion without rib head resection for treating type I neurofibromatosis with intra-canal rib head dislocation. Clinics 68:1521–1527. doi: 10.6061/clinics/2013(12)08 PubMedCentralPubMedCrossRefGoogle Scholar
  10. 10.
    Easwar TR, Hong JY, Yang JH, Suh SW, Modi HN (2011) Does lateral vertebral translation correspond to Cobb angle and relate in the same way to axial vertebral rotation and rib hump index? A radiographic analysis on idiopathic scoliosis. Eur Spine J 20:1095–1105. doi: 10.1007/s00586-011-1702-0 PubMedCentralPubMedCrossRefGoogle Scholar
  11. 11.
    Aaro S, Dahlborn M, Svensson L (1978) Estimation of vertebral rotation in structural scoliosis by computer tomography. Acta Radiol Diagn 19:990–992CrossRefGoogle Scholar
  12. 12.
    Smorgick Y, Settecerri JJ, Baker KC, Herkowitz H, Fischgrund JS, Zaltz I (2012) Spinal cord position in adolescent idiopathic scoliosis. J Pediatr Orthop 32:500–503. doi: 10.1097/BPO.0b013e318259ff4e PubMedCrossRefGoogle Scholar
  13. 13.
    Ton J, Stein-Wexler R, Yen P, Gupta M (2010) Rib head protrusion into the central canal in type 1 neurofibromatosis. Pediatr Radiol 40:1902–1909. doi: 10.1007/s00247-010-1789-1 PubMedCentralPubMedCrossRefGoogle Scholar
  14. 14.
    Cappella M, Bettini N, Dema E, Girardo M, Cervellati S (2008) Late post-operative paraparesis after rib penetration of the spinal canal in a patient with neurofibromatous scoliosis. J Orthop Traumatol 9:163–166. doi: 10.1007/s10195-008-0010-x PubMedCentralPubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Saihu Mao
    • 1
  • Benlong Shi
    • 1
  • Shoufeng Wang
    • 1
  • Chengyue Zhu
    • 1
  • Zezhang Zhu
    • 1
  • Bangping Qian
    • 1
  • Feng Zhu
    • 1
  • Xu Sun
    • 1
  • Zhen Liu
    • 1
  • Yong Qiu
    • 1
  1. 1.Department of Spine SurgeryThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina

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