+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Pin force measurement in a halo-vest orthosis, in vivo



Pin force measurement in a halo-vest orthosis, in vivo



Journal of Biomechanics 31(7): 647-651



The halo-vest is an orthosis commonly used to immobilize and protect the cervical spine. The primary complications associated with the halo-vest have been attributed to cranial pin loosening. However, the pin force history during day-to-day halo-vest wear has not previously been reported. This paper presents a new technique developed to monitor cranial pin forces in a halo-vest orthosis, in vivo. A strain gaged, open-ring halo was used to measure the compressive and shear forces produced at the posterior pin tips. The strain gages measured the bending moments produced by these forces without compromising the structural integrity of the halo-vest system. The prototype halo measured the compressive and shear force components with a resolution of +/- 15 and +/- 10 N, respectively. To test the feasibility and durability of the device, it was applied to one patient requiring treatment with a halo-vest orthosis. At the time of halo-vest application, the mean compressive force in the two posterior pins was 368 N. Over the 3 month treatment period, the compressive forces decreased by a mean of 88%. The shear forces were relatively insignificant. Using this technology future work will be aimed at determining the causes of pin loosening, optimizing vest and pin designs, and investigating the safety of more rapid rehabilitation.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 032828455

Download citation: RISBibTeXText

PMID: 9796687

DOI: 10.1016/s0021-9290(98)00071-2


Related references

Pin loosening in a halo-vest orthosis: a biomechanical study. Spine 25(11): 1325-1331, 2000

Optimal use of the halo-vest orthosis for upper cervical spine injuries. Yonsei Medical Journal 51(5): 648-652, 2010

Acute pulmonary edema following removal of a spinal orthosis: an unusual complication of a halo vest. Archives of Physical Medicine and Rehabilitation 71(3): 255-257, 1990

A new halo-vest: rationale, design and biomechanical comparison to standard halo-vest designs. Spine 13(3): 228-235, 1988

A new method of tightening halo orthosis pins that reduces initial pin force variation. Biomedical Sciences Instrumentation 38: 245-250, 2002

A methodical study of force measurements in three patients with odontoid fractures treated with a strain gauge-equipped halo-vest. Spine 13(4): 433-435, 1988

Failure of halo vest to prevent in vivo motion in patients with injured cervical spines. Spine 16(10 Suppl): S501-S505, 1991

In vivo analysis of atlantoaxial motion in individuals immobilized with the halo thoracic vest or Philadelphia collar. Spine 34(7): 670-679, 2009

Structural behavior of the halo orthosis pin bone interface biomechanical evaluation of standard and newly designed stainless steel halo fixation pins. Spine 11(10): 977-981, 1986

Immediate synergistic effect of a trunk orthosis with joints providing resistive force and an ankle-foot orthosis on hemiplegic gait. Clinical Interventions in Aging 13: 211-220, 2018

Forces in the halo-vest apparatus. Spine 9(8): 773-777, 1984

Adapting shirts to fit over a halo vest. American Journal of Occupational Therapy 33(8): 524-525, 1979

Halo vest effect on balance. Archives of Physical Medicine and Rehabilitation 81(3): 255-257, 2000

Use of halo vest to immobilize cervical spine. Journal of the Iowa Medical Society 70(5): 197-9 202, 1980

Halo-fixator vest--indications and complications. Zentralblatt für Chirurgie 132(1): 54-59, 2007