Complex fracture-dislocations of the elbow can often be either irreducible
or unstable, with an inability to hold the reduction or with the delayed
development of subluxation or dislocation. The aim of the present study was to
evaluate the etiology of the instability, both osseous and ligamentous, and
the results of stabilization with a combination of internal fixation, ligament
repair, radial head arthroplasty and, when necessary, hinged external
fixation. Figures 1 and
2 represent our formulated
protocol and treatment algorithm for elbow fracture-dislocation in this series
of thirty-two patients.
The so-called terrible triad injury has a history of complicated outcomes
as the surgeon attempts to maximize functional range-of-motion goals while
maintaining
stability1-3.
On the basis of previous evaluations of these specific injuries and the recent
evolution of surgical protocols, the restoration of congruency and stability
coupled with progressive rehabilitation can reliably enhance the functional
outcome4-6.
Thirty-two consecutive patients with unstable elbow injuries who had been
referred to three tertiary centers were prospectively recruited for the
present study between 2001 and 2005. Six of these patients had been
unsuccessfully managed at outside facilities and had been transferred to our
care. The unsuccessful treatments had included attempted closed reduction
(four patients), radial head excision (one patient), and open reduction and
internal fixation of the proximal part of the ulna (one patient).
All patients were evaluated with fine-cut computerized tomographic scans,
including sagittal, coronal, and three-dimensional reconstructions. All elbows
were approached with use of a posterior global
incision7,8.
Ulnar neurolysis was routinely performed. The medial and lateral ligament
complexes were inspected and repaired by means of direct suture repair or with
use of suture anchors. Internal fixation of the radial head was attempted when
possible, or a radial head arthroplasty was performed. The coronoid-brachialis
complex was repaired with use of pull-through sutures. Elbow stability was
then tested, and a hinged external fixator was used when indicated. All
fixators were removed at six weeks, and indomethacin prophylaxis was
administered for eight weeks to decrease the risk of heterotopic
ossification.
All patients were examined clinically, radiographically, and with the
Disabilities of the Arm, Shoulder and Hand (DASH) self-administered
questionnaire. Range of motion, articular congruity, elbow stability, and
complications were serially documented, and mean results were calculated for
each treatment protocol in our algorithm.
All of the patients in the present prospective evaluation were managed by a
single surgeon (M.K.P.) with use of the algorithm shown in
Figure 2. The majority of
patients were placed in the lateral position with the injured arm placed over
a radiolucent post, and a sterile tourniquet was applied. Intraoperative image
intensification was used. A posterior global
incision7,8
was preferred (Figs. 3,
4-A, and 4-B), but,
alternatively, the patient was placed supine with a radiolucent extremity
board6. With the
patient in the supine position, a lateral Kocher surgical
approach7,8
was used; however, this approach is preferable only if (1) no medial
abnormality is identified and (2) the surgeon is confident that the
coronoid-brachialis complex can be repaired through the lateral incision. The
lateral approach also facilitates radial head replacement.
Coronoid-Brachialis Capsular-Ligamentous Complex
The coronoid fracture is typically a shear fracture, not an avulsion
fracture9. The
coronoid-brachialis complex, with the attached capsular-ligamentous
structures, forms the anterior restraint to dislocation. It is inevitably
damaged when the ulna is dislocated posteriorly and the distal part of the
humerus is translated anteriorly. Type-1 coronoid fractures are often
associated with this injury. The bone fragments are often comminuted and not
amenable to internal fixation. In these cases, repair of the
coronoid-brachialis capsular-ligamentous complex is as important as the
fixation of a type-2 or type-3 coronoid base fracture. Repair is performed
with use of a pull-through suture technique devised by the senior author
(M.K.P.) as shown in Figures 5-A through
5-E. A locking stitch is placed in the cartilaginous ledge at the
soft-tissue attachment to the brachialis with use of a heavy number-2 braided
nonabsorbable suture. Bone fragments are ignored or incorporated in the
locking stitch. A 2.3-mm passing pin with an oval eye, commonly used for
anterior cruciate ligament reconstructions (Smith and Nephew, Memphis,
Tennessee), is used to drill, by hand, a hole from the subcutaneous border of
the ulna, exiting at the coronoid tip. The passing pin is then reversed to
allow the eye of the pin to be delivered into the wound to pull the locking
stitch through the subcutaneous border of the ulna. Two strands of sutures are
pulled through two separate holes, which are placed at least 7 mm apart at the
coronoid exit point. The sutures are then pulled tight to reduce the
coronoid-brachialis capsular-ligamentous complex to the bone and are tied over
the subcutaneous border of the ulna, with the elbow flexed at 90°. The
anteromedial facet of the coronoid, if fractured, requires fixation as
described by O'Driscoll et
al.3.
Radial Head Reconstruction or Replacement
The decision to replace or repair the radial head is based on a
preoperative evaluation of the radiographic studies and careful intraoperative
assessment of the degree of comminution, fracture displacement, and fragment
size. Specifically, fractures that involve more than one-third the articular
surface of the radial head with >2 mm of displacement and any sizeable
comminution are replaced. Reconstruction is performed with use of
tissue-sparing plate fixation (Acumed, Hillsboro, Oregon). Replacement is
usually performed with a monopolar modular implant (EVOLVE; Wright Medical
Technology, Arlington, Tennessee) (Figs.
6-A through
7-B). Occasionally, a cemented
bipolar implant (CRF II; Tornier, Grenoble, France) is used to compensate for
bone loss (Figs. 8-A through
8-D). The modularity of this device makes it easier to implant the
stem initially and to repair the coronoid-brachialis capsular-ligamentous
complex prior to implantation of the head component.
In cases in which the radial head is not reconstructable, replacement is
required. Once the remnants have been excised, the coronoid-brachialis
capsular-ligamentous complex is easily accessible through the lateral window
and should be repaired before the radial head is replaced. Similarly,
displaced radial head fragments can be set aside for later reconstruction
after the coronoid-brachialis capsular-ligamentous complex is repaired. Even
if the radial head is intact, disruption of the lateral ulnar collateral
ligament makes the coronoid-brachialis capsular-ligamentous complex easily
accessible from the lateral soft-tissue window.
Application of External Fixation
External fixation was applied to supplement stability at the time of
surgery on the basis of our protocol (Figs.
9,
10-A, 10-B, and
11). A hinged external fixator
positioned over the center of rotation of the elbow allows for early
mobilization without the danger of anterior subluxation. The center of
rotation of the elbow is the center of the trochlear and capitellar
"spool," which can be seen clearly as a circle on the true-lateral
radiographic projection.
Two types of fixators were used in the present study, depending on
availability at the time of surgical intervention (Compass Universal Hinge
[Smith and Nephew] and OptiROM Elbow Hinged Fixator [EBI, Biomet Trauma,
Parsippany, New Jersey]). The Compass hinge has the advantage of being a
circular fixator and offers multiaxial fixation. The OptiROM hinge is the only
currently available elbow hinge fixator in which the central hinge has been
expanded, providing a virtual hinge through which radiographs of the elbow can
be made to give a true-lateral image of the elbow without metal interference
(Fig. 10-A). The hinge must be
tested intraoperatively to allow for full frictionless range of motion without
soft-tissue resistance. The humeral fixation pins can be placed in the lateral
plane or posteriorly (posteromedially and posterolaterally) through the
triceps. The former can endanger the radial nerve, whereas the latter can
cause triceps tethering that restricts elbow flexion. It is imperative not to
insert the radial pins percutaneously. We prefer to make a formal incision and
to dissect down to bone, carefully watching for and avoiding the radial nerve.
This is best done as the last step of the operation after removal of the
sterile tourniquet. A zone within 2 to 3 cm from the deltoid insertion is the
safest area for the insertion of humeral pins in the lateral plane.
Postoperative Care and Rehabilitation
Early mobilization is encouraged if a hinge fixator is used. If external
fixation is not utilized, a well-padded hinged brace is applied with the elbow
at 90° of flexion. The forearm is rested in pronation to protect any
lateral ligament repair. If both collateral ligaments are repaired or no
ligament repair is performed, the forearm is placed in neutral rotation.
Protected mobilization is commenced at ten to fifteen days. Indomethacin
(25 mg, administered orally three times per day) is used for a period of three
weeks for prophylaxis against heterotopic ossification.
The hinged fixator is removed six weeks after surgery, and physiotherapy is
pursued to achieve maximum range of motion.
All thirty-two patients underwent a repair of the coronoid-brachialis
complex. The radial head was noted to be intact in six elbows. It was able to
be reconstructed in seven of thirteen cases in which reconstruction was
attempted, and it was replaced in nineteen cases. A lateral repair alone was
performed in eighteen cases, a medial repair alone was performed in two cases,
and a combined medial and lateral repair was performed in twelve cases.
Twenty-one elbows required protection in a hinged external fixator; the
Compass hinged fixator was used in nine elbows, and the OptiROM hinged fixator
was used in twelve.
After a mean duration of follow-up of three years (range, one to five
years), all thirty-two elbows had a functional arc of motion from 30° to
130°. The mean extension loss was 12° (range, 0° to 20°), the
mean flexion loss was 14° (range, 0° to 20°), and a full range of
motion was exhibited by three patients. The average DASH score was 23 (range,
19 to 28).
Despite having received indomethacin prophylaxis, three patients had
development of minor heterotopic ossification, which did not affect the final
outcome. The patients who had been managed with radial head arthroplasty
exhibited no intermediate-term problems such as loosening or capitellar
wear.
Reconstruction of complex elbow fracture-dislocations represents one of the
most troublesome and unpredictable procedures that orthopaedic surgeons face.
We have found that three-dimensional computerized tomographic reconstructions
are very useful to facilitate preoperative planning and to stage the
treatment. The algorithm that we have developed
(Fig. 2) represents a
systematic approach to achieve the goals of reestablishing stability and
functional motion. Our goal was prompt surgical stabilization once the acute
swelling had subsided. Adequate stability must be achieved intraoperatively.
In our limited experience, patients with a complex elbow dislocation who had a
hinged elbow fixator had an earlier return of mobility. Our preference now is
to use the OptiROM external fixator (EBI, Biomet Trauma) as it provides the
ability to make lateral radiographs of the elbow joint and intraoperative
fluoroscopy through the central hole in the expanded hinge. ?