Lin, James S.

Background: Pediatric thumb ulnar collateral ligament (UCL) injuries usually have osseous involvement presenting as a Salter-Harris III avulsion fracture from the base of the proximal phalanx. There is limited guidance about when surgical or non-surgical treatment is more appropriate. Methods: Patients with thumb bony UCL injuries who presented to a large pediatric hospital between 2007 and 2017 were retrospectively identified. Demographics, fracture pattern, treatment, clinical course, and outcomes were collected. Radiographic measurements included size and displacement of fracture fragment as a percentage of the proximal phalanx base articular surface. A classification system was developed incorporating clinical stability of the metacarpophalangeal joint and quantity of displacement. Results: Sixty-five patients were included (47 males and 18 females). The mean age at time of injury was 14.8 SD 1.9 yrs old. 46 (71%) injuries occurred during sporting activities. 50 (77%) patients underwent nonsurgical management with immobilization, and 15 (23%) patients were treated surgically with open reduction internal fixation. For patients treated surgically, the mean fragment size was 28.2% SD 6.8% of the articular surface compared to 14.3% SD 12.5% of those treated non-surgically (P<0.0001). The mean fracture displacement for surgically treated patients was 32.7% SD 19.0% compared to 11.4% SD 7.3% of those treated non-surgically (P<0.0001). Overall, 100% of patients reported they were able to return to their previous level of activity. Conclusion: Many pediatric thumb bony UCL injuries can be treated non-surgically. A classification system based upon joint stability and fracture displacement may help guide appropriate management of these injuries.

Cases: Two patients with spontaneous loss of thumb interphalangeal joint extension were referred after history, electrodiagnostic, and/or magnetic resonance imaging (MRI) findings were felt to demonstrate a posterior interosseous nerve (PIN) palsy. Subsequent physical examination and additional directed studies suggested an alternative explanation: rupture of the extensor pollicis longus (EPL) tendon, subsequently confirmed at surgery. An extensor indicis proprius to EPL transfer restored thumb function. Conclusion: Electrodiagnostic and MRI changes consistent with diffuse PIN palsy may occur in the setting of EPL rupture. An accurate diagnosis of EPL dysfunction requires careful physical examination and confirmatory imaging. Further study of this previously unreported phenomenon is required.

Distal radioulnar joint instability is commonly seen after surgical fixation of a distal radial fracture, and surgeons’ ability to reliably determine stability on examination is poor. Debate remains regarding whether to fix the ulnar styloid or reinsert the triangular fibrocartilaginous complex. Four surgeons with Level 5 expertise were asked to respond to questions surrounding this debate.

Degenerative wrist conditions, such as scapholunate advanced collapse and scaphoid nonunion advanced collapse, often require salvage procedures to reduce pain and improve function. For early stages of disease, both proximal row carpectomy and scaphoid excision four-corner arthrodesis are viable motion-preserving options. There remains controversy on which technique is superior. Selection is a nuanced decision that requires consideration of patient characteristics and stage of disease. The traditional notion that proximal row carpectomy should be reserved for older individuals with low demands has been challenged; long-term studies in younger populations demonstrate similar patient-reported outcomes, pain relief and survivorship without conversion to total wrist arthrodesis between proximal row carpectomy and four-corner arthrodesis. The existing evidence suggests proximal row carpectomy has advantages of greater range of motion, fewer complications and lower costs. Advancements such as arthroscopic techniques for both procedures show potential, although mastery involves a steep learning curve.