PIP Joint Dislocations

By admin On Oct 23, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Safdar Akbar

Basics

Description

Dislocation of the proximal interphalangeal (PIP) joint
Hinge joint allowing flexion and extension with little lateral movement because collateral ligaments are tight through entire range of motion (ROM)
Dislocations may be dorsal (most common), ventral, or rotary subluxation, where the twisting injury to the finger causes buttonholing of the head of the proximal phalanx through a tear in the central slip and lateral band.
Synonym(s): Finger dislocation

Epidemiology

Most commonly injured joint in the hand

Risk Factors

Playing sports

General Prevention

Wear appropriate sport-specific padding and safety equipment when participating in sports or activities.

Diagnosis

History

Ascertain the direction of dislocation if already reduced.
Determine mechanism: Dislocated finger may be due to forced hyperextension or hyperflexion of digit from traumatic athletic injury, entrapment of finger between objects, or a fall.

Physical Exam

Swelling and deformity if not already reduced by coach or friend
Deformity will indicate direction of dislocation.
Careful palpation about the joint to locate the most tender area can help to differentiate between injuries.
- Volar tenderness: Volar plate
- Lateral joint-line tenderness: Collateral ligaments
- Dorsal tenderness: Central slip injury
Neurologic examination before and after reduction: Check sensation in distal finger.
Check extensor tendon function: Have patient actively extend PIP and distal interphalangeal (DIP) joints.
If able to extend DIP but not PIP joint, consider central slip rupture, which may lead to a boutonniere deformity. Extended DIP and flexed PIP with late loss of DIP flexion is the most disabling problem.
Check flexion.
- Have patient actively flex PIP joint with other fingers held in extension.
- Check DIP flexion with PIP held in extension.
- If unable to flex DIP joint, consider flexor digitorum profundus rupture, which requires surgical consultation.
Check collateral ligaments.
- Apply radial and ulnar stress with PIP joint in full extension and 30 degrees of flexion.
- Look for increased laxity.
Check volar plate.
- Excessive hyperextension is consistent with volar plate injury.
- If volar plate is unstable and not treated properly, it will lead to hyperextension of the PIP joint and flexion of DIP joint, a swan-neck deformity.

Diagnostic Tests & Interpretation

Imaging

X-rays: 2 views, including anteroposterior and lateral, before reduction if possible
Oblique view if initial x-rays are negative but high suspicion of fracture
Ensure joint congruity to rule out fracture-dislocation.
May see small volar avulsion fracture
With rotary subluxation, will see true lateral view of middle phalanx with oblique view of proximal phalanx, or vice versa

Differential Diagnosis

Fracture-dislocation: Large dorsal fracture-dislocations can be missed, with the volar fracture involving >75% of joint surface with dorsal subluxation of the remaining portion of the middle phalanx.
Central extensor tendon rupture (boutonniere injury) rupture of central slip allows lateral bands to slip below PIP joint and cause PIP flexion with distal interphalangeal (DIP) extension.

P.471

Treatment

Long-term treatment
Acute treatment:
- Dorsal dislocation: Reduction:
  - If reduced before onset of swelling, reduction is easier.
  - Reduce with longitudinal traction and gentle pressure to the dorsal aspect of the midphalanx.
- Postreduction evaluation:
  - X-rays: 2 views if not already obtained
  - Rule out dorsal fracture-dislocation.
  - Check collateral ligament stability after reduction.
- Immobilization:
  - If dorsally dislocated and stable, simple, and reduced quickly, patient can continue sporting activity after “buddy taping” fingers if injury is to nondominant hand.
  - Stable: Splint for 1–2 wks in 15–20 degrees of flexion (also may use extension block splint) until pain-free. Often have volar plate injury; if so, consider splint in flexion for 4–5 wks.
  - Splint should include only PIP joint; may be dorsal or volar.
  - “Buddy tape” for an additional 3–4 wks.
  - Can treat with “buddy taping” alone for 3–6 wks if no volar plate injury
- Volar dislocation: Reduction:
  - Same as for dorsal dislocation
  - Closed treatment if minimally displaced avulsion fracture
  - Avulsion fracture reduces with full extension.
- Postreduction evaluation:
  - X-rays: 2 views
  - Check collateral ligament stability after reduction.
- Immobilization:
  - Splint PIP joint in full extension for 6 wks (dorsal or volar splint) because central slip is often involved, DIP and metacarpophalangeal joints free.
  - Need to actively and passively flex DIP joint
  - Night splint for an additional 3–4 wks
  - Splint until full active extension of PIP joint and active flexion of DIP joint
- Rotary subluxation: Reduction:
  - Sometimes difficult to reduce closed
  - Closed reduction:
    - Digital block
    - Gentle traction with metacarpophalangeal and PIP joints at 90 degrees of flexion
    - Dorsiflex wrist (relaxes extensor mechanism).
    - Apply gentle rotatory and traction force.
- Postreduction evaluation:
  - X-rays: 2 views
  - Check collateral ligament stability after reduction.
- Immobilization: “Buddy tape” after closed reduction.

Additional Treatment

Additional Therapies

Rehabilitation:

Dorsal dislocation: Work on ROM when out of splint.
Volar dislocation: Work on ROM of DIP and metacarpophalangeal joints while in splint.
Rotary subluxation: Start active and passive ROM when out of splint; add resisted ROM when pain-free, active and passive ROM.

Surgery/Other Procedures

Unable to reduce closed
Dorsal fracture-dislocation carries significant risk of long-term disability if treated improperly.
Volar dislocation with significant avulsion fracture or fracture does not reduce with extension and carries high risk of disability if treated improperly.

Additional Reading

Eiff MP, Hatch RL, Calmbach WL. Finger fractures. In: Fracture management for primary care. Philadelphia: WB Saunders, 1998.

Green DP, Butler TE. Fractures and dislocations in the hand. In: Rockwood CA, Green DP, Bucholz RW, Heckman JD, eds. Rockwood and Green's fractures in adults, vol. 1, 4th ed. Philadelphia: Lippincott-Raven Publishers, 1996.

Green DP, Strickland JW. The hand. In: Delee JC, Drez D, eds. Orthopaedic sports medicine: principles and practice. Philadelphia: WB Saunders, 1994:945–1017.

Palmer RE. Joint injuries of the hand in athletes. Clin Sports Med. 1998;17:513–531.

Codes

ICD9

834.02 Closed dislocation of interphalangeal (joint), hand