Comparing Motion Outcomes in Salvage Procedures for Wrist Arthritis
Abstract
Scaphoidectomy and four corner fusion (4CF), and proximal row carpectomy (PRC) are salvage procedures that may be offered in advanced wrist arthritis. The optimal clinical treatment remains unclear. Biomechanical studies comparing outcomes of these procedures often only report uniplanar motion, rather than multiplanar motion which is more representative of functional wrist motion. Further, the impact of altering the relationship of the proximal and distal carpal rows in the coronal plane during 4CF has not been well-studied.
The purpose of this in-vitro biomechanical study was to quantify changes in wrist kinematics during wrist flexion-extension, radial-ulnar deviation, and circumduction in “anatomic 4CF”, “radial 4CF”, and PRC conditions using an active motion simulator. Three important findings are reported: 1) Radial-aligned 4CF resulted in reduced wrist extension and total circumduction compared to the native state, 2) Anatomic 4CF was more restricted in wrist extension than PRC, while PRC was more restricted in radial deviation compared to 4CF, and 3) Total circumduction area was similar between anatomic 4CF and PRC.
These results suggest that 4CF and PRC have comparable motion outcomes. When patients are candidates for either operation, the advantages and disadvantages of each must be considered. If the decision to perform 4CF has been made, anatomic 4CF may provide a better motion profile, provided there is adequate bone stock between the capitate and lunate. In certain situations, adjusting the alignment of the proximal and distal carpal rows is required, making radial 4CF more appropriate. Further clinical investigation comparing these procedures is warranted.