Biomechanical Rationale for the Pathology of Rheumatoid Arthritis in the Craniovertebral Junction

Abstract

To the best of the authors' knowledge, this is the first report of a validated, three-dimensional model of the C0-C1-C2 complex with application to rheumatoid arthritis. The data indicate that there may be a mechanical component (in addition to enzymatic degradation) associated with the osseous resorption observed during rheumatoid arthritis. Specifically, erosion of the odontoid base may involve Wolff's law of unloading considerations. Changes through the lateral aspects of the atlas suggest that this same mechanism may be partially responsible for the erosive changes seen during progressive rheumatoid arthritis. Anterior and posterior atlantodental interval values indicate that complete destruction of the transverse ligament coupled with alar and/or capsular ligament compromise is requisite if advanced levels of atlantoaxial subluxation are present.

Surgical Considerations of Rheumatoid Disease Involving the Craniocervical Junction and Atlantoaxial Vertebrae

“…Enzymatic degradation causing erosion of the odontoid process have been shown to occur (Scutellario & Orzincolob 1988, Mancur & Williams 1995, a biomechanical process of osteolysis occurring at the odontoid peg base which also causes bony resorption. This phenomenon, consistent with Wolff's Law, occurs in rheumatoid patients due to transverse ligament laxity resulting in significant odontoid peg stress reduction and resultant localised osteopenia (Puttlitz et al 2000). This ligamentous laxity-odontoid osteopenia cycle results in the commonly seen atlantoaxial instability in rheumatoid patients.…”

“…This ligamentous laxity-odontoid osteopenia cycle results in the commonly seen atlantoaxial instability in rheumatoid patients. Puttlitzz's study (Puttlitz et al 2000) of a validated fully threedimensional finite element model of rheumatoid development and progression also suggests a biomechanical mechanism underlying the resorption of lateral masses of rheumatoid atlases. An alteration in the contact force data, resulting in an unloading of the lateral aspects of the atlantoaxial and occipitoatlantal joints will result in localised resorption and osteopenia.…”

Development and initial evaluation of a finite element model of the pediatric craniocervical junction

“…Similarly, the problems investigated by adult FEMs, such as odontoid fractures, rheumatoid arthritis, and the effects of posterior instrumentation, are not commonly demonstrated in children. 5,32,33,38 The pediatric CCJ differs from the adult CCJ in many important ways. Greater ligamentous laxity, different joint angles and relationships, a greater ratio of head mass to body size, and the presence of immature cartilage all play a part in differentiating the pediatric CCJ from its adult counterpart.…”

“…Recent advances in computational power have allowed researchers to use FEMs to examine the biomechanical behaviors of a wide variety of skeletal structures, including the spine. 4,7,21,22,32,33,36 The FEM must also be evaluated with cadaveric biomechanical test results, which, as discussed above, are very difficult to obtain for the pediatric population.…”

Die Zervikale Myelopathie als Komplikation der Rheumatoiden Arthritis

“…Die häufigste Variante -und meist auch erste -ist die horizontale atlantoaxiale anteriore Subluxation mit Instabilität im Atlantodentalgelenk und Gelenkspalterweiterung [64]. Ursache ist eine Schädigung des Ligamentum transversum und der Ligamenta alaria sowie sekundär häufig auch eine Lockerung der okzipito-atlanto-axialen Gelenkkapseln [96,106]. Eine Destruktion der kleinen Wirbelgelenke ist Folge der Subluxation, nicht ihre Ursache [121].…”