Abstract
Purpose: The purpose of this study is to investigate the external and internal vascular anatomy of the lunate bone. The genesis of lunatomalacia requires some combination of load, vascular risk and mechanical predisposition. The findings will be correlated with the major existing theories of the cause of lunatomalacia and the most frequent fractures associated with Kienbocks disease: transverse shear fracture and midcoronal fracture.
Material and methods: We studied 21 cadaver upper limbs using latex injection and Spalteholz technique. We investigated the extra- and intraosseous blood supply. In 17 wrists we evaluate the incidence and distribution of anatomic features, arthrosis, and soft tissue lesions.
Results: The lunate morphology was 5 Type I (29.4%), 11 Type II (64.7%) and 1 Type III (5.9%). The lunate was found to have a separate facet for the hamate in 47.1% (Size 3–6 mm). Most frequent arthrosis was identified in the radius (88.2%) and lunate (94.1%). The triangular fibrocartilage complex (TFCC) was found torn in 47%, the lunotriquetral interosseous ligament (LTIL) was torn in 23.5%, and the scapholunate interosseous ligament (SLIL) was torn in 53% of the wrists. Statistical analysis found a correlation between the presence of arthrosis at the proximal pole of the hamate and the presence of a lunate facet. There was also a correlation between the presence of a tear in the SLIL and the presence of cartilage erosion in the scaphoid (p= 0.002). Arthrosis on the lunate was found to have a correlation with an SLIL tear or TFCC tear. The nutrient vessels entered the lunate throught the dorsal and volar poles in all the specimens. Dorsal vessels enter the bone through one or two foramina in the proximal, ulnar, and nonarticular aspect of the bone. Two to six nutrient vessels were observed entering the volar pole throught a ligament insertion: radioscapholunate ligament of Testut-Kuentz, radio-lunate-triquetrum ligament and ulnar-lunate-triquetrum ligament.
Conclusions: The lunate had consistent dorsal and palmar arteries entering the bone in all the specimens. The supply blood and foramina number is more important in the volar pole of the lunate than the dorsal pole. The vascular patterns support a theory of compression fracture from repeated trauma, or anatomical predispositions as the most likely cause of Kienbocks disease.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
