Lunate loads following different osteotomies used to treat Kienböck's disease: A 3D finite element analysis

Abstract

Background: One of most accepted principles for treating Kienböck's disease before wrist degeneration settles in is to decompress the lunate by an osteotomy. Several osteotomies have been proposed since 1935. However, they are based on biomechanical hypotheses that are sometimes conflicting: This study compares the decompression effect of radius transverse shortening, radius lateral closing and medial closing wedge osteotomies, capitate shorteningwith and without hamate shorteningand a Camembert-type radius wedge osteotomy with and without ulnar head shortening according to Sennwald. Methods: We built a 3D wrist model using finite elements that included the metacarpal, carpal and forearm bones. All wrist ligaments and Triangular Fibrocartilage Complex were incorporated in the simulation. Load was applied on the metacarpals with the forearm bones fixed. We then applied the different osteotomies to the model. Findings: When load was applied to the wrist, the osteotomies that best unloaded the lunate were the capitate shortening osteotomy combined with hamate shortening and the Camembert osteotomy combined with ulna shortening; the latter was the only osteotomy that completely unloaded the lunate. Interpretation: We think the association of the radius Camembert osteotomy and ulna Sennwald's shortening osteotomy is the most effective procedure to propose in Kienböck's disease.

Kienböck’s disease: preventing disease progression in early-stage disease

“…JLPs initially had the goal of achieving neutral ulnar balance in cases of negative ulnar variance, to counteract the predisposing effect for developing KD described by Hulten in the late 1920 s (Hulten, 1929). Although there is much doubt about this concept, these techniques do mechanically decompress the lunate in different degrees (Camus et al., 2020) and usually provide good functional results compared with the unpredictable long-term natural course of KD (Viljakka et al., 2014). Other procedures focused on treating the biological aspect of KD, such as VBGs, can be combined with a JLP in a multimodal approach and salvage procedures can still be performed if needed.…”

“…The selective shortening wedge osteotomy or ‘camembert’ osteotomy shortens only the part of the radius facing the lunate, offloading the bone without decompressing the scaphoid as is done in the other osteotomies. It may need an associated ulnar wedge osteotomy, but it has the most beneficial biomechanical effect (Camus et al., 2020).…”

“…Many biomechanical studies have demonstrated that a capitate shortening osteotomy (CSO) effectively unloads the lunate and radiolunate joint (An, 1993; Camus et al., 2020) without overloading the radioscaphoid or ulnocarpal joints. Despite that, the authors have very seldom performed this type of osteotomy.…”

Novel Descriptions of the Radial Osteotomy in Kienböck’s Disease: A Systematic Review

“…Clinical outcomes have been generally satisfactory across the spectrum of osteotomy techniques; however, there is conflicting evidence. 3 , 4 , 5 , 6 A recent systematic review showed superior clinical outcomes including pain and wrist range of motion in cases of Kienböck’s disease treated with radial osteotomy compared with cases treated nonsurgically. 4 Importantly, the authors noted that the radial osteotomy group had more advanced disease than the nonsurgical group.…”

“…A biomechanical study has validated the decompressive effect of radial osteotomy on the lunate. 5 The magnitude of lunate unloading substantially varied between osteotomy techniques, with some techniques providing minimal decrease in radiolunate loading.…”