gms | German Medical Science

Objectives/Interrogation: Scapho-Trapezium-Trapezoid (STT) arthritis is commonly treated by isolated distal scaphoid resection or plus biologic interposition. Isolated distal scaphoid resection can reduce carpal height developing DISI deformity in long term follow up. Scapho trapezium pirocarbon implant (STPI) is used as a spacer to maintain carpal height and reduce long term DISI deformity. Good tolerance of Pirocarbon and profile of the implant give good life expectancy.

AIM: In this retrospective study the authors describe their experience with the use of a Pirocarbon implant for distal scaphoid in STT arthritis.

Methods: From January of 2007 to September of 2018 42 wrists (Viegas 1 and 2) of 36 patients were treated. All cases were evaluated pre and post-operatively with MMWS, PRWHE and DASH scores with an average follow-up of 72 months (min 3 - Max 138). 6 cases were treated bilaterally.

Results and Conclusions: There was an average relief from pain, no significant improvement in flexion extension ROM and significant improvement grip and pinch strength. At the follow-up there was an average reduction of pain from 7,01 to 1,7 VAS. There was an improvement of grip and pinch force from 51% to 88% of contralateral side. 85% of the patients were satisfied with the results and were able to return to the precedent activities. Improvement of DASH from 89 to 15,6 and of PRWHE from 101 to 19. Radiographic controls revealed 6 cases of complication with 1 case of dislocation of the implant, light reduction in carpal height in 4 pz and average radio-lunate angle passed from 11° pre-operatively to 14° post-operatively.

Replacement of distal pole of scaphoid with STPI can restore a good functionality of wrist and pinch, a complete range of motion free from pain in patients affected from STT arthritis maintaining carpal height and avoiding increase of capito-lunate angle or collapse.