Association of Lesions of the Scapholunate Interval With Arthroscopic Grading of Scapholunate Instability Via the Geissler Classification

PurposeTo determine whether specific anatomic lesions of the scapholunate supporting structures are associated with the grades of scapholunate instability according to the Geissler classification.MethodsSix fresh frozen cadaveric limbs underwent serial arthroscopic sectioning of the scapholunate supporting ligaments. To simulate a progressive scapholunate injury based on the current literature, sectioning occurred as follows: volar scapholunate interosseous ligament (SLIL), membranous SLIL, dorsal SLIL, radioscaphocapitate, long radiolunate, dorsal radiocarpal, dorsal intercarpal, and scaphotrapeziotrapezoid ligaments. We performed arthroscopic examination of the radiocarpal and midcarpal joints after each ligamentous sectioning and recorded the appearance of the scapholunate interval.ResultsThere was a progressive increase in Geissler grade with sequential sectioning of the scapholunate supporting ligaments. In all specimens, Geissler grade 2 injury was associated with sectioning of intrinsic ligaments only. Geissler grade 3 injury first appeared with sectioning through the dorsal SLIL and continued through sectioning of the volar extrinsic ligaments. Geissler grade 4 injury did not occur until the dorsal extrinsic ligaments were sectioned. Statistical analysis indicated a linear relationship between ligament sectioned and Geissler grade, with deeper sections associated with a higher Geissler grade.ConclusionsIn this cadaveric model, arthroscopically determined Geissler grade was associated with specific anatomic lesions of the scapholunate supporting ligaments. Sequential sectioning of the ligaments showed a progressive increase in Geissler grade.Clinical relevanceKnowledge of the association of Geissler grade with pathoanatomy may aid the surgeon in deciding which reconstructive method is best.