Lunate Shift Index (LSI): A New Parameter for the Evaluation of Residual Ulnar Side Wrist Pain in Patients with Wrist Osteoarthritis Undergoing Three-Corners Arthrodesis vs. Four-Corners Arthrodesis-A Retrospective Comparative Study with Minimum 2 Years of Follow-up.

Purpose: Both scaphoid non-union advanced collapse wrist (SNAC) and scapho-lunate advanced collapse wrist (SLAC) at stage II-III are common indications for limited wrist fusions including four-corners fusion (4CF) and three-corners fusion (3CF). The aim of this study was to assess the clinical and radiological outcomes in patients undergoing 3CF vs. 4CF. A new radiological index called Lunate Shift Index (LSI) was devised to evaluate the importance of the lunate displacement relative to the radiolunate joint. Materials and Methods: Twenty-eight patients undergoing 3CF and 40 patients undergoing 4CF were clinically evaluated. The radiolunate angle, the carpal height, and the LSI were recorded radiographically. The LSI corresponds to the ratio between the distance from the lunate centre to the middle of the intermediate column and the length of the intermediate column of the distal radius. Results: A statistically significant correlation was observed between LSI and clinical outcomes. The lunate displacement was associated with an increased incidence of wrist ulnar pain. No statistically significant differences were observed between 3 and 4CF in all parameters compared. Conclusions: The osteoarthritis of piso-triquetral joint has been identified as the cause of wrist ulnar pain in patients undergoing 4CF. The lunate correct positioning allows to maintain the carpal height and to increase the contact area at the level of the radiolunate joint. A good reduction of the lunate could be obtained with the 3CF compared to 4CF. This study showed how proper realignment of the lunate following midcarpal arthrodesis correlates with a better clinical outcome. Level of Evidence: Level III, Retrospective comparative study.

From the central pivot to the peripheal knee injuries in the skier: a narrative review.

The improvement in the technology in the last 20 years has showed its main effect on the increase of the speed in the curves, thus leading to a rise of knee injuries. In fact, the most injured zone of the body was the knee (35,6 %) and the distal part of the lower body (11,5%), with ACL lesion as the most frequent diagnosis (49% of all the injuries to the knee) due to a trauma in valgus and external rotation in most of cases. The MCL is involved in the 15-20% of the cases while the LCL in only the 4,2% of the patients. Unique epidemiology and distinct mechanisms of injuries are peculiar for skier's knee while evaluation and treatment is similar to evaluation and treatment of knee injuries in other athletes. In this narrative review we aimed to highlight the current evidences in skiers' traumatology with special focus on the treatment nowadays proposed in the international literature and to the return to sport.