Kevin,
As I stated previously my concern in providing an external torsion and where that occurs is a major concern.
see below
Pediatr Orthop. 1991 Sep-Oct;11(5):583-7.
Effects of lateral rotation splinting on lower extremity bone growth: an in vivo study in rabbits.
Barlow DW, Staheli LT.
University of Washington School of Medicine, Seattle.
To study the effect of lateral splinting on limb development, 14 immature rabbit femurs and tibias were marked with six parallel pins. Of these, the lower limbs of seven rabbits were splinted in lateral rotation for 3 weeks (1-year human equivalent). The static position of the foot in the splinted group was 23 degrees more lateral (p greater than 0.05) than in the control group. No significant difference was found in the axial alignment of the pins across the growth plate or diaphyses between the splinted or control groups. This study suggests that night splinting alters the joint relationships and not the shape of the femur or tibia.
If you attempt to provide compensation elsewhere, what effect is this having on the normal ontogenic development of joint rotations?
regards
Tony
________________________________
From: A group for the academic discussion of current issues in podiatry on behalf of Kevin Kirby
Sent: Tue 23/11/2004 05:05
To: [log in to unmask]
Subject: Re: Serial Casting for Internal Tibial Position
Tony and Colleagues:
Tony wrote:
<<In regard to my concerns as to where external torques are applied, this may help.
Moreland MS. Morphological effects of torsion applied to
growing bone: an in-vivo study in rabbits. J Bone Joint Surg
1980;62B:230-7.>>
Here is the complete abstract of the article you cited, Tony:
Morphological effects of torsion applied to growing bone. An in vivo study in rabbits.
J Bone Joint Surg Br 1980 May;62-B(2):230-7 (ISSN: 0301-620X)
Moreland MS
In order to study the effect of pure torsional forces upon the rotational development of the growing tibia, 35 immature rabbits underwent torsional loading of one tibia in vivo with a spring-loaded cylinder while the other tibia was a control. The radiographic results showed rotation occurring only at the epiphysial plate. Histologically this was assocaited with angulation of the hypertrophic cartilage columns occurring as little as 24 hours after loading which with longer periods of loading produced angled primary and secondary trabeculae. Radiographic and histological analyses of the diaphysis using tetracycline labeling and Spalteholtz injection techniques failed to show any evidence of cortical remodeling or reorientation of the cortical vessels of a rotational nature, suggesting that rotational modelling occurs solely at the epiphysial plate.
After careful review of the abstract of the article you provided, Tony, it seems that if an external rotation moment can be applied to the tibia of a rabbit and show a histological change within 24 hours within the epiphyseal plate in response to this external rotation moment, then this would certainly tend to support my hypothesis that an external rotation moment placed on the tibia in a human child could also cause a rotation in the epiphyseal plate to effect a correction in abnormal tibial torsion. In fact, Ron Valmassy was teaching this same fact to us at CCPM over 20 years ago that he thought the changes he saw in the malleolar torsion with the use of a night splint was occurring at the epiphyseal plate. The epiphyseal plate is part of the tibia and will ossify as the child matures into adulthood. Therefore, these facts make it imperative that we offer our best treatments to these young children that may help them avoid embarrassment, physical disability, or abnormal pathological function of the foot from the abnormal torsional problems in their lower extremities.
Every day of delay in treating the pediatric deformity is a golden opportunity lost forever (Kirby KA, Green DR: Evaluation and Nonoperative Management of Pes Valgus, pp. 295-327, in DeValentine, S.(ed), Foot and Ankle Disorders in Children. Churchill-Livingstone, New York, 1992).
Cheers,
Kevin
****************************************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Private Practice:
107 Scripps Drive, Suite 200
Sacramento, CA 95825 USA
Voice: (916) 925-8111 Fax: (916) 925-8136
****************************************************************************
----------------------------------------------------------------- This message was distributed by the Podiatry JISCmail list server
All opinions and assertions contained in this message are those of the original author. The listowner(s) and the JISCmail service take no responsibility for the content.
to leave the Podiatry email list send a message containing the text leave podiatry to [log in to unmask]
Please visit http://www.jiscmail.ac.uk for any further information -----------------------------------------------------------------
-----------------------------------------------------------------
This message was distributed by the Podiatry JISCmail list server
All opinions and assertions contained in this message are those of
the original author. The listowner(s) and the JISCmail service take
no responsibility for the content.
to leave the Podiatry email list send a message containing the text
leave podiatry
to [log in to unmask]
Please visit http://www.jiscmail.ac.uk for any further information
-----------------------------------------------------------------
|
