We retrospectively evaluated a consecutive series of 42 Motec thumb carpometacarpal total joint arthroplasties. The primary endpoint was revision with implant removal and trapeziectomy. At follow-up the disability of the arm shoulder and hand (DASH) score, pain on numerical rating scale at rest and with activity and serum chrome and cobalt concentrations were assessed for both unrevised and revised patients. At a mean followup of 26 months, 17 patients had been revised. The 2 year cumulative revision rate was 42% (95% CI, 28-60%). The DASH score and pain scores at rest and with activity were comparable between the patients whose thumbs remained unrevised and those revised. Patients with elevated serum chrome and cobalt levels had significantly higher DASH and pain scores, but elevated levels were not associated with revision. The revision rate in this study is unacceptably high. However, pain and DASH scores after revision are acceptable and comparable with patients with non-revised implants. Level of evidence: IV

In this prospective study, we aimed to analyse the early results of 200 consecutive total trapeziometacarpal joint arthroplasties using the Moovis cup, a new generation, dual-mobility, uncemented conical cup, with special focus on early complications. At the 24-month follow-up, we found clinically relevant improvement of function and comfort. Among intraoperative complications were nine intraoperative trapezial fractures, which were treated by screw osteosynthesis; prolonged immobilization; and conversion to cemented cup fixation or primary or secondary trapeziectomy. One was left untreated as the loose cup did not cause notable symptoms. There were three implants with polyethylene wear and two with liner dislocation. We conclude that early outcomes of this new-generation implant are favourable, but its surgery is challenging and associated with important intraoperative and early postoperative complications related to the learning curve. Attentive reaming of the trapezium and careful cup impaction are crucial steps to avoid trapezial fracture and early cup failure. Level of evidence: II

Distal radioulnar joint instability is difficult to grade by clinical examination and interobserver reliability is low. This study used a new and precise radiostereometry method for measurement of distal radioulnar joint translation. Eight human donor arms were positioned in a custom-made fixture and a standardized piano key test was done with pressure on the ulnar head. Examination was done before and after dividing the styloid and foveal insertions of the triangular fibrocartilage complex. In the intact wrists, the piano key test induced a mean 1.36 mm translation of the ulnar head, which increased statistically significantly to 1.96 mm after a lesion of the styloid ligament insertion and to 2.3 mm after combined lesions of the styloid and foveal ligament insertions. This experimental cadaver study demonstrates a radiological method for precise quantification of distal radioulnar joint stability after different grades of triangular fibrocartilage complex injury.