Aspen® CTO

Biomechanical Analysis of Cervical Orthoses in Flexion  and Extension: A Comparison of Cervical Collars and Cervical Thoracic Orthoses

Gavin, T; Carandang, G; Havey, R; Flanagan, P; Ghanayem, A; Patwardhan, A
Musculosketal Biomechanics Laboratory, Edward Hines Jr., Department of Veterans Affairs Hospital, Maywood, Illinois
Published in J of Rehabilitation Research and Development, 2003 Nov./Dec., Vol. 40, No. 6, 527-538

Abstract

The analysis of current cervical collars (Aspen and Miami J collars) and cervical thoracic orthoses (Aspen 2-post and Aspen 4-post) in reducing cervical intervertebral and gross range of motion in flexion and extension was performed using 20 normal volunteer subjects.

Selected Quotations

“It is important that the prescribing physician recognizes the differences between the function of cervical orthoses, so they may make informed decisions as to which orthosis is most appropriate for a specific condition.”

(Pg. 527)

Gross Head Motion Restriction
“Flexion motion allowed in the Miami J collar was significantly greater than that allowed in the Aspen collar. No significant difference was found between the two collars in extension.”

(Pg. 531)

Neck (CO to C7) Motion Restriction
“When measuring angular motion of CO relative to C7 using VF images, we found no statistically significant differences in angular motion allowed between the Miami J and Aspen collars in either flexion or extension.”

(Pg. 531)

Intervertebral Angular Motion Restriction
“No significant differences in flexion were allowed at any intervertebral segment between the Aspen or Miami J collars except at C5-6, where the Miami J allowed more motion.”

(Pg. 532)

“In restricting angular motion in flexion, the CTO’s were significantly better than the collars at C3-4, C5-6 and C6-7 segments.”

(Pg. 532)

Discussion
“The capability of the 4-post CTO to effectively restrict extension motion seems to contradict the current thinking that the halo may be the only effective orthosis for reducing motion in extension.”

(Pg. 536)

Conclusion
“Our findings suggest that either of the two collars could be used to treat similar cervical pathologies or injuries except those involving the C5-6 segment, where the Aspen collar may provide better motion restriction.”

(Pg. 537)

Hangman's Fracture: Therapy Selection and Treatment Efficacy Evaluation

Jun Zhou, MD, PHD; Huilin Yang, MD, PHD; Lian Chen, Zhigang Zhang; Cheng Ji, MD
The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Poster presented at NASS 24^th Annual meeting. Published in The Spine Journal 9 (2009) 143S.

Abstract

BACKGROUND CONTEXT: Since Hangman's fracture was initially noted in 1965 by Schneider et al, anatomy and the proposed mechanism of this injury have been well documented; however, controversy regarding the optimal treatment of it has continued to linger.

PURPOSE: To discuss the selection of therapy for Hangman's fracture and determine the treatment efficacy.

STUDY DESIGN/SETTING: Retrospective design.

PATIENT SAMPLE: A total of 29 patients from 2002-2008, male 20 cases, femal 9 cases, with a mean age of 39 years (16-57 years).

OUTCOME MEASURES: Levine-Edwards system was used to classify the fractures, and radiographs were used to determine motion, angulation and fracture union.

METHODS: Type I, Type II and part of Type IIA Hangman's fractures were treated with early collar or halo-vest immmobilization after traction reduction, buy Type IIA with an angulation of greater than or equal to 12º between C2 and C3 and Type III fractures were treated with surgical procedure (posterior occipital fusion or C1-3 fusion).

RESULTS: There were a total of 8 Type 1, 14 Type II, 5 Type IIA and 2 Type III Hangman's fractures. Three patients presented with neurologic deficits caused by spinal cord injury, nine patients were found to have associated spinal fractures. The mean follow-up was 18 months (4-37 months). All fractures progressed to union. There was no implant failure (loosening, bending, or breakage of screws).

CONCLUSIONS: Early collar or halo-vest immobilization after traction reduction of Type I, Type II and part of Type IIA Hangman's fractures is an effective method of management. Type IIA with an angulation of greater than or equal to 12º between C2 and C3 and Type III fracture may require posterior occipital fusion or C1- 3 fusion.

FDA DEVICE/DRUG STATUS: Halo-Vest: Approved for this indication; Sofamor Transpedicular Internal Fixation System: Approved for this indication.