1. Carpus Overview of the topic Upper Extremity Education taskforce
Meeting (Arial 20 pt)
2019
City, Month, Year (Arial 20 pt)

2. Case: 24 yo fell on outstretched hand after a snowboard jump

3. Learning objectives Describe how to investigate the problem
Classify the lesion
Relate injury patterns to indications and treatment
Decision making (including avoid complications)
Manage using a structured approach

4. Anatomy and biology
Multiple bones, articular surfaces and small ligaments Complex motion – weakest link fails and affects entire joint Poor healing - think scaphoid non union and SL tears that don’t heal with lesser energy injuries Poly trauma patients 25% - compromised healing, other health issues, missed injuries 25%

5. Mayfield Courtesy of Graham Lister
Two names to keep in mind Mayfield and Herzberg
Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. May 1980;5(3):226-41
Courtesy of Graham Lister

6. Mayfield Two names to keep in mind Mayfield and Herzberg
Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. May 1980;5(3):226-41

7. Herzberg Stage I Lunate within fossa
Stage IIa Dislocated from fossa but rotated less than 90°
Stage IIb Dislocated and rotated 90°+
Herzberg et al2 classified these injuries as stage I when the lunate remains located in its fossa, stage IIA when it is dislocated from it fossa but rotated less than 90°, and stage IIB when it is dislocated and rotated more than 90°

8. Classification 2/3 have fractures
95% of the fractures are transcaphoid
Most are dorsal dislocations 90%
Stage IIb can not be closed reduced

9. Investigation
Clinical - median nerve stretch versus compression Radiological plain X-rays 25 % missed CT scan for clarification if required

10. Key features
Radiocarpal joint space Midcarpal joint space Lateral collinearity

11. Treatment Median nerve Carpus
Closed intervention is not enough - failure to heal
Re-establish normal relationships
Maintain relationships for healing to occur
Therapy - early to maintain finger motion
Later for wrist motion

12. Take-home messages Spectrum of injury patterns
Check for median nerve dysfunction
Thorough x-ray analysis
Decompression median nerve where appropriate
Surgical intervention to restore and repair normal bone and ligamentous anatomy and allow for slow healing

13. Surgery
Urgent reduction to reduce pressure on median nerve with appropriate monitoring followed by definitive surgical stabilization, see below
Urgent ORIF for progressive nerve dysfunction (carpal tunnel release), IIB, open injuries
Repair of all bone and soft-tissue to restore carpal stability. ORIF plus ligament repair, maintenance of reduction with IF (K-wires/screws/RASL)
Dorsal approach +/- volar approach