Assessing ulnar instability of the metacarpophalangeal joint of the thumb

MRI of the Stener lesion

“…The examination is performed using local anesthesia with the MCP joint in flexion and extension to identify ligamentous laxity. A complete tear of the UCL with instability is diagnosed when subluxation of more than 35 ~ difference with respect to the opposite side is noted [5]. This method, however, cannot differentiate between displaced and nondisplaced ligamentous tears [14,15].…”

“…If, on the other hand, the UCL becomes displaced and trapped superficially to the adductor pollicis aponeurosis, as discussed by Stener (Stener lesion), primary healing cannot occur and surgery is advocated by many authors [2][3][4][5]. The Stener lesion is not always discernible clinically and is not detectable radiographically, but early diagnosis of this condition may be crucial to primary surgical repair of the UCL [6,7].…”

Injury to the Ulnar Collateral Ligament of the Thumb

“…There is also a rare variation of this injury where the ulnar collateral ligament remains intact, and there is an avulsion fracture involving the volar plate [25,29].…”

A biomechanical modeling of injury, repair, and rehabilitation of ulnar collateral ligament injuries of the thumb

“…A consensus regarding which injuries show sufficient instability to require surgery has not been established. [2][3][4][5][6][7][8] Almost universally all surgical treatment protocols advise total immobilization of the MCP joint for a minimum of 4 weeks, often with pinning of the MCP joint during this period. 9 -13 Although the clinical stability achieved by traditional repair techniques has been excellent, many series report reductions in motion and strength, even in the long term.…”