Background: Treatment of tibial plafond fractures with external
fixation may involve use of transfixation wires within the periarticular
region. Pin track infections that develop along wires placed intracapsularly
may lead to joint infection. To our knowledge, there have been no previous
investigations assessing the circumferential reflection of the ankle capsule
or the potential for communication between the distal tibiofibular joint and
the tibiotalar joint. The purpose of this study was to define these anatomic
entities to provide guidelines for safe extracapsular placement of distal
Methods: Twelve fresh-frozen cadaveric ankles and three ankles of
living human volunteers were utilized for this study. High-resolution magnetic
resonance imaging was performed on each ankle after pressurized distention of
the joint capsule with gadolinium solution. The perpendicular distance from
the subchondral bone at the joint line to the capsular synovial reflection was
measured with use of a verified technique. The cadaveric ankles were
sectioned, the capsular synovial reflections were measured by investigators
who were blinded to the imaging results, and the corresponding measurements
Results: The anterolateral capsular synovial region displayed the
most proximal reflection in all specimens (mean, 9.3 mm; maximum, 12.2 mm).
The anteromedial region displayed less reflection (mean, 3.3 mm; maximum, 5.5
mm). All posteromedial and posterolateral synovial reflections were =2 mm.
Capsular synovial reflections proximal to the medial and lateral malleoli were
negligible. In all ankles, the distal tibiofibular joint communicated with the
tibiotalar joint and had a maximum proximal extension of 20.6 mm.
Conclusions: Placement of distal tibial transfixation wires >12.2
mm from the subchondral surface of the plafond avoids penetration of the
capsule. The distal tibiofibular joint communicates with the tibiotalar joint
and thus should not be penetrated, to ensure extracapsular placement of the
Clinical Relevance: Stabilization with distal tibial transfixation
wires should be proximal to the reflected joint capsule and should avoid
penetration of the distal tibiofibular joint to minimize the risk of
penetration of the capsule and the potential for joint infection as a sequela
of superficial pin track infection.