Interphalangeal Joint Dislocation Interphalangeal joint dislocations almost always occur dorsally, look for associated avulsion fractures! Here's a quick summary. • PIP joints are the most commonly involved and the dislocation is usually dorsal • DIP and PIP joints are stabilized by the joint capsule. collateral ligaments (prevent radial and ulnar displacernent), and the solar plate (prevents hyperextension) • DIP joint hinge joint; ROM of —0-80 degrees of flexion; lateral slips of the extensor tendons come together form the terminal slip which attaches to the dorsal distal phalanx to enable extension; flexor digitorum profundus attaches to the palmar distal phalanx to enable flexion • PIP joint = hinge joint; ROM — 0-120 degrees of flexion; central slip of the extensor tendons attaches to the dorsal middle phalanx to enable extension; flexor digitorum superficialis attaches to the palmar middle phalanx to enable flexion • Mechanism: Hyperextension injury with axial load (ball striking fingertip) • Exam: Pain and deformity of the affected digit • Possible associated injuries: Avulsion fracture • Complications include swan neck deformity (if dorsal PIP dislocation, due to EDS and/or volar plate rupture), boutonniere deformity (if volar PIP dislocation, due to rupture of the central slip of the extensor tendon), mallet finger deformity (if volar DIP dislocation, due to rupture of the terminal slip of the extensor tendon) • ED Management: Digital block and reduction • Splint: Finger splint • Ortho consult: No (unless unable to reduce or a concomitant fracture renders the joint unstable) • Disposition: Discharge with orthopedic follow-up within 1 week MH/CCF/CWRU EM Res @MetroHealth_EM #Interphalangeal #Joint #Dislocation #IPJoint #Radiology #XRay #Diagnosis #Management #Hand #Orthopedics #MSK
