Introduction Defined as instability between rows (either radiocarpal or midcarpal) radiocarpal instability (between radius and proximal row) midcarpal instability (between proximal and distal row) Epidemiology incidence rare Pathophysiology and Mechanism radiocarpal instability ("inferior arc injury") high-energy injury ulnar translation signifies global rupture of extrinsic ligaments distal radius malunion is the most common cause may be purely ligamentous or have associated ulnar and radial styloid fractures Associated conditions intracarpal injury (scapholunate or lunotriquetral ligament) acute carpal tunnel syndrome compartment syndrome Prognosis volar dislocation is more severe than dorsal Anatomy Volar extrinsic ligaments radioscaphocapitate (RSC) long radiolunate short radiolunate radioscapholunate Classification Overview table of wrist instability Presentation History usually no history of trauma (midcarpal) high energy trauma (radiocarpal) Symptoms subluxation that may or may not be painful complain of wrist giving way irritating clunking sign "clunk" when wrist is moved ulnarly from flexion to extension with an axial load Physical exam generalized ligamentous laxity Imaging Radiographs recommended views required AP and lateral of the wrist optional cineradiographs findings sudden subluxation of proximal carpal row with active radial or ulnar deviation on cineradiograph ulnar translation diagnosis made when >50% of lunate width is ulnarly translated off the lunate fossa of the radius Treatment Nonoperative immobilization +/- splinting indications first line of treatment midcarpal instability is most amenable to splinting Operative immediate open repair, reduction, and pinning indications ulnar translation associated with styloid fractures outcomes poor results with late repair ligament reconstruction has poor long term results midcarpal joint fusion indications midcarpal instability (preferred over ligamentous reconstruction) late diagnosis that failed nonoperative management outcomes will lead to 20-35% loss of motion osteotomy with malunion correction indications distal radius malunion wrist arthrodesis indications failure of above treatments outcomes fusion of radiocarpal joint leads to a 55-60% loss of motion
Technique Guide Technique guide are not considered high yield topics for orthopaedic standardized exams including the ABOS, EBOT and RC. Four Corner Wrist Fusion Orthobullets Team Hand - Scaphoid Lunate Advanced Collapse (SLAC)
QUESTIONS 1 of 1 1 Previous Next (OBQ11.52) A 22-year-old gymnast with known ligamentous laxity has been treated in the hand therapy clinic for 6 months for left wrist pain and discomfort. Radiographs of her left wrist are seen in Figures A and B. Which of the following physical exam findings would be most diagnostic for midcarpal instability? Review Topic | Tested Concept QID: 3475 FIGURES: A B Type & Select Correct Answer 1 Radial wrist pain with sudden ulnar deviation 1% (32/3304) 2 Tenderness to palpation distal to the ulnar styloid 0% (16/3304) 3 Pain and a clunk on ulnar to radial deviation of the wrist while pressure is held on the scaphoid 40% (1316/3304) 4 Pain in the lunate with volar directed pressure on the dorsum of hand 6% (184/3304) 5 Pain and a clunk with axial and palmarly directed forces as the wrist is moved from neutral to ulnar deviation 52% (1733/3304) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept
All Videos (1) Podcasts (0) Login to View Community Videos Login to View Community Videos 29th Orthopaedic Trauma - What We Need to Know in 2017 Case: Carpal Instability: Failed ORIF, What went wrong? - R. Kumar Kadiyala, MD - (NYT #31 - S5-7- 2017) R. Kumar Kadiyala Hand - Carpal Instability Nondissociative (CIND) 10/4/2017 398 views (1)