AAHS ASPN ASRM - 2013 Annual Meeting - American Association ...

Introduction
AAHS SPECIALTY DAY PROGRAM 2007
“Pilon & PIP Fracture- Dislocation”
Joseph F. Slade, III, MD
Associate Professor & Director
Hand and Upper Extremity Service
Department of Orthopaedics & Rehabilitation
Yale University School of Medicine
Joseph.slade@yale.edu
“Rapid Recovery- The Fast Track”
9:30-9:50AM
AAHS 2007 ANNUAL MEETING
PUERTO RICO
Wednesday, January 10th, 2007
Pilon fractures are comminuted intra-articular fractures of the base of the middle phalanx. These fractures are
a result of axial loading which cause a disruption of articular rim of the base of the middle phalanx both the dorsal and
volar articular surface. This injury results in central articular depression and widening of the base of the proximal phalanx.
Stern reported that pilon fractures treated with external fixation resulted in similar results from those treated with
ORIF, but without the associated complications of open repair. Salter determined that early motion of articular injuries
resulted in healing and remodeling of an injured joint surface. Schenck applied Salter’s principles and design an orthotic
traction splint which permitted passive motion while applying continuous traction. This traction splint used ligamentotaxis
to mold the injured base of the middle phalanx articular surface to the condyles of the proximal phalanx during
healing. There were two concerns about continuous traction in the treatment of pilon fractures. The first, was the ability
of traction alone to prevent levering at the fracture site as it attempted to glide around the Condyles. The second,
was the force required to maintain reduction. These problems were solved by the placement of a fulcrum just distal to
the fracture site. The application of a lever reduces the forces required to maintain fracture reduction. The fulcrum also
acts as a check to joint subluxation as the joint glides through a full arc of motion. The dynamic traction external fixator
maintains congruent reduction of a pilon fracture while restoring hand function by permitting early initiation of
both active and passive motion protocols.
Anatomy of PIP Joint
The PIP joint is a constrained hinge joint whose stability is conferred by both the matched bone contouring at the joint interface
and the capsular complex composed of stout lateral cords and mobile volar plate. The head of the proximal phalanx is cam shaped
and composed of a bicondylar head with a central groove. The doubly concave surface of the base of the middle phalanx is divided by
a midline tongue to guide the joint through its eccentric arc of motion. The main lateral stabilizer of this joint is the proper collateral
ligament. This ligament originates from the head of the proximal phalanx and inserts into the base of the middle phalanx. The proper
collateral ligament is joined to the volar plate by shroud-like fibers of the accessory collateral ligament. These two structures function
as a composite unit to resist both the lateral and hyperextension stresses on the joint. In extension the volar plate is tight and the collateral
ligament is moderately lax. As the joint flexes the collateral ligament tightens over the larger volar condlyes to seat the base of
the middle phalanx firmly against the proximal phalangeal head. In flexion, the volar plate is lax. The average ROM at the PIP joint
is approximately 110 degrees.
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