Lesions of the fibrocartilaginous triangle of the carpus (FCTC) and lunatopyramidal (LP) instability are the most frequently treated situations involving ulnar instability of the wrist. Most publications to date have examined results obtain for the treatment of isolated lesions, few have reported associated injuries. Outcome could be better in terms of pain relief: 25–64% of pain-free results for the treatment of FCTC and unpredictable results for the treatment of LP instability.
Considering the column theory proposed by Navarro-Taleisnik we have developed a concept based on fixation of the pyramidal and an adaptation of the Mayfield lines (where kinetic energy is considered exclusively on the ulnar side); we present here what we call the «peripyramidal ring lesion».
In our series of surgical cases, pain-free outcome for combined ulnar lesions treated as FCTC lesions was achieved in 48% of cases. For cases treated as LP instability, the rate was 71.4%. Many combinations are underdiagnosed: pyramidal-median hamate, pyramidal-pisiform. By treating these combined lesions we have increased the rate of excellent results from 64% to 91% for FCTC and obtained 86% pain-free wrists for LP instability.
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