Dynamic External Fixation for Unstable Fracture-Dislocations and Pilon Fractures of the Proximal Interphalangeal Joint
Centro Médico MEDEX, Perú
Submission: September 07, 2016; Published: September 19, 2016
*Corresponding author: Ricardo Monreal, República de Panamá 3065 2do piso, San Isidro-Lima, Perú, Email:firstname.lastname@example.org
How to cite this article: Ricardo M. Dynamic External Fixation for Unstable Fracture-Dislocations and Pilon Fractures of the Proximal Interphalangeal Joint. Ortho & Rheum Open Access J. 2016; 2(5): 555598. DOI: 10.19080/OROAJ.2016.02.555598
Introduction: Several methods are used in the treatment of intra-articular proximal interphalangeal joint fractures. The purpose of this study was to evaluate the effectiveness of a simple handmade dynamic external fixator for unstable fracture-dislocations and pilon injuries of the PIP joint in an active-duty population and to investigate whether or not these patients had adequate finger movement.
Materials and Methods: Eleven consecutive patients were treated with a simple dynamic external fixator between 2008 and 2014. The analysis of the results was based on the clinical, radiological, and subjective criteria judging Range of Motion of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints, total active motion of the injured finger, and deformity.
Results: The cases included 3 females and 8 males with a mean age of 34 years (range of 19-54 years). The mean follow-up period was 7 months (range, 3â€“16). Seven patients (77%) attained excellent, 3 (33%) attained good, and 1 (9%) attained fair to poor results. All patients returned to their prior level of activity and duties.
Conclusion: Dynamic external fixation is recommended as the preferred method for dealing with fracture dislocations of the PIP joint because it avoids the soft tissue trauma associated with open surgical techniques. Fixation using this handmade dynamic external fixator for the treatment of the proximal interphalangeal fractures is safe, inexpensive and easy to apply.
Injuries to the proximal interphalangeal joint (PIPJ) of the fingers are common. They occur most often following an axial impact on an extended finger. Fractures of the proximal interphalangeal joint include a wide spectrum of injuries, from stable avulsion fractures to complex fracture-dislocations. Stability of the joint is paramount in determining the appropriate treatment, which should aim to facilitate early mobilization and restoration of function.
The purpose of this clinical investigation was to retrospectively review use of simple and handmade dynamic external fixation for unstable fracture-dislocations and pilon injuries of the PIP joint in an active-duty population.
A retrospective study was conducted in patients treated with a previously described simple dynamic fixator with no rubber
bands(1,2) applied to 11 patients who sustained unstable fracture dislocations or pilon fractures of the PIP joint between 2008 and 2014.
Fracture-dislocation of the PIP was defined as a fracture of the middle phalangeal lip (volar or dorsal) associated with dislocation. An unstable fracture-dislocation was defined as having at least 30% of the articular surface involved, in conjunction with the inability to maintain a concentric reduction of the PIP joint.
The pilon injury type was defined as a fracture in which both the volar and dorsal lips are involved in the fracture. Pilon injuries of the PIP joint are almost always unstable (>1 mm of articular step-off and grossly unstable through full active range of motion). No displaced pilon injuries can be stable; but, this type of injury is rare.
Patients were excluded from the study if they had open injuries or injuries to multiple digits, had sustained a prior injury to the same digit or if they had less than 6 months of
follow-up. The injuries occurred in 1 long, 5 ring, and 5 small
fingers (Table 1).
All procedures were successfully completed under digital
anesthesia without use of sedation, and all patients in our cohort
were able to flex and extend at the PIP joint intraoperatively.
After a closed reduction of the PIP joint fracture-dislocation
performed under 31 digital anesthesia and fluoroscopic
guidance, a simple frame described by Gaul and Rosenberg 
and modified by Badia et al.  is assembled from two 1.4-mm
Placement of the K wires is the most critical step. The first
K-wire (K1) is placed transversely through the center of the head
of the proximal phalanx and the second K-wire (K2) is driven
through the head of the middle phalanx (Figure 1a).
Both sides of the K1 are left long enough so the ends can be
bent 90° distally to lie parallel and 1 cm away from the middle
phalanx (X) (Figure 1b). Two more bends are applied to the
proximal phalanx wire (K1): a dorsal bend (90°) at the base of the distal phalanx approximately 1 cm distal to K2 (Y) (Figure
1b) and another bend on each end of the pin (horn). Traction is
applied on the middle phalanx to engage K2 wire in the horns
of K1 (Z) of the proximal phalanx (K1) wire, achieving the
desired skeletal traction. The K2 ends are bent to maintain the
engagement of K1-K2 and used to adjust the distraction the PIP
joint (Figure 1b).
Intraoperative x-rays are obtained to confirm that the
articular surface of the base of the middle phalanx is not in
contact with the condyles of the proximal phalanx. This system
provides active longitudinal traction while preserving the joint
space and allowing PIP joint motion. The finger is placed in a
soft minimally bulky dressing, incorporating the external fixator.
The dressings are removed the next day and immediate
active flexion extension of the PIP joint is supervised by the
hand therapist (Figure 2) (Supplemental Video 1). Cleansing of
the pin sites is performed twice a day with a mixture of iodine
and saline. After 4 weeks, the fixator is removed under local
anesthesia in the outpatient clinic and physiotherapy continued
(Figure 3) (Supplemental Video 2). Radiographic and clinical
assessments are obtained at final follow-up evaluation (Table 2).
The analysis of the results was based on the clinical,
radiological, and subjective criteria described in (Table 2),
judging Range of Motion (ROM) of the MCP, PIP, and distal
interphalangeal (DIP) joints, Total Active Motion (TAM) of the
injured finger, and deformity. Each fracture was evaluated and
classified according to Rajesh et al.  in one of four categories:
excellent (pain-free union, no angular/rotational deformity, PIP
movement of >100°, total active ROM of >250°); good (occasional pain, minimal angular/rotational deformity, PIP movement of
>80°, total active ROM of >180°); and fair to poor (pain, angular/
rotational deformity, PIP movement of ≤80°, total active ROM of
≤180°). Deformity was described as minimal if it was apparent to the physician but was not a functional or cosmetic problem
for the patient. Otherwise, results were placed in the fair to poor
A Student’s t-test was performed to determine whether
the type of fracture (fracture-dislocation vs pilon), or the digit
involved (index, long, ring or small finger) had an impact on the
final ROM at the PIP and DIP joints.
The cases included 3 females and 8 males with a mean age of
34 years (range of 19-54 years). The mean follow-up period was
7 months (range, 3–16).
At final evaluation no instability was observed in any of
the PIP joints. Proper reduction and congruency of the joint
was noted on final anteroposterior and lateral radiographs.
The average range of motion of the PIP joint at final follow-up
evaluation was 3° to 94° (range, 0° to 100°). The final distal
interphalangeal range of motion was on average 0° to 71° (range,
0° to 82°).
Seven patients (77%) attained excellent, 3 (33%) attained
good, and 1 (9%) attained fair to poor results (Table 2). All
patients returned to their prior level of activity and duties.
When comparing the relative effect of digit involved (p=0.02),
and fracture-dislocations versus pilon injuries (p=0.006), there
were statistically significant differences in PIP joint and DIP
joint range of motion.
Those patients who achieved the greatest degree of PIP
joint flexion displayed frame translation in conjunction with radiographic evidence of osteolysis in the head of the proximal
phalanx. These areas of lysis resolved after removal of the fixator
without the need for further intervention.
One patient developed pin tract infection that resolved with
oral antibiotics and required premature removal of the fixator (3
weeks).No patient had subsequent surgery.
The proximal interphalangeal joint (PIPJ) is the most
commonly injured joint in the hand. Although most of these
injuries are simple ligamentous sprains, more severe fracture
dislocations can occur. Of these, dorsal fracture dislocations are
the most common.
The PIP joint is prone to stiffness following even minor
sprains; therefore, early diagnosis and treatment of severe
fracture-dislocations is essential to achieve optimal function.
Fracture-dislocations of the PIP joint are caused by two basic
mechanisms: avulsion or impaction shear. The direction of the
middle phalanx versus proximal phalanx is used to categorize
the injury as a dorsal fracture-dislocation (i.e., dorsal dislocation
with fracture of the middle phalangeal volar lip) or a volar
fracture-dislocation (i.e., volar dislocation with fracture of the
dorsal lip of the middle phalanx). The third category is a pilon
injury in which both the volar and dorsal lips are involved in the
The main concern of management is the stability of the joint.
It is determined by the size of the articular fragment of the base
of the middle phalanx involved and the degree of impaction of
the articular surface.
Unstable fracture-dislocations (at least 30% of the articular
surface involved and inability to maintain a concentric reduction
of joint) require surgical intervention.
Pilon injuries of the PIP joint are almost always unstable and
require surgical intervention. No displaced pilon injuries can be
stable and can be managed nonsurgical; but, this type of injury
When a finger has a painful, unstable PIP joint with a limited
arc of motion, overall hand function is greatly impaired. The
objectives of treatment of fracture-dislocation of the PIP joint
are to reduce the fracture dislocation, allowing early range of
motion without compromising stability, prevent posttraumatic
arthritis by restoring a congruent joint surface, and optimize
functional outcome by maintaining stable range of motion. An
aligned and reduced joint is necessary for acceptable clinical
outcome [5, 6].
Management of comminuted intrarticular fractures of
the base of the middle phalanx poses a therapeutic dilemma.
Ideally, anatomic restorations of the joint and early motion are
mandatory to minimize posttraumatic arthritis and stiffness.
In reality, however, this goal may be impossible because of
excessive intraarticular and subchondral comminution.
With regard to the articular surface, quality of reduction has
not been shown to correlate with clinically relevant posttraumatic
arthrosis in the PIP joint. Several investigators have shown that a
small intraarticular step-off can be well tolerated .
Several treatment techniques have been described to
treat proximal interphalangeal fracture dislocations and pilon
fractures of the middle phalanx, including extension block
splinting [7,8] or pinning , open reduction and internal
fixation , hemi-hamate arthroplasty , volar plate
arthroplasty [12,13], skeletal traction  force couple splinting
 and external fixation [1,2,16-18]
The first reference to external fixation for the treatment of
PIP fracture-dislocations was in 1946 when Robertson et al. 
described a triplane external fixation device . Later in 1986,
Schenk et al.  again proposed the dynamic external fixation
method for the treatment of PIP fractures .
Many different dynamic external fixators have been described
and some of them provide only a traction force, whereas others
provide traction as well as a translational force to keep the joint
reduced. The ideal dynamic external fixator should be equally
effective at maintaining joint reduction as allowing range of
motion. It should be inexpensive and easy to apply. We have
obtained satisfactory results just by applying the dynamic fixator described by Gaul and Rosenberg  and modified by Badia el al.
. Only a minor complication (pin tract infection) was reported
using this device (Table 1) that resolved with oral antibiotics and
required premature removal of the fixator (3 weeks). No patient
had subsequent surgery.
The patients who demonstrated the greatest motion with
the fixator in place often demonstrated osteolysis around
the proximal phalanx axis pin. This can be attributed to the
mechanical effect of motion around the pin and was resolved in
every case after removal of the fixator.
Although differences were noted in final motion based on
the finger involved or type of injury (better results middle/ring
vs. little finger, and pilon vs. fracture-dislocation type) this study
has some weaknesses including small patient cohort and the
short length of follow-up.
Some loss of motion is expected in nearly all cases of PIPJ
fracture-dislocations, regardless of treatment. Nevertheless, a
functional, pain-free PIP joint is a reasonable treatment goal in
patients with acute injuries.
Dynamic external fixation is recommended as the preferred
method for dealing with fracture dislocations of the PIP joint
because it avoids the soft tissue trauma associated with open
surgical techniques. Fixation using this handmade dynamic
external fixator for the treatment of the proximal interphalangeal
fractures is safe, inexpensive and easy to apply.