Preoperative Evaluation
The preoperative evaluation of elbow stiffness in children includes the
recording of a full general medical history and a detailed evaluation of the
disability and the loss of function. Review of all radiographs, including
injury radiographs, and documentation of previous operations is of utmost
importance to understand the underlying pathology.
Any history of previous manipulations with the patient under anesthesia is
recorded. These maneuvers can cause intra-articular damage by avulsion of
cartilaginous fragments with subsequent damage to the residual cartilage, and
we do not advocate that method of treatment. After a thorough clinical
examination is carried out, plain radiographs are made for analysis of the
joint space and joint congruency as well as the status of the physes and the
axes of the articulating bones. High-resolution computed tomography scans with
a 1-mm slice thickness are performed in order to reveal possible subluxation,
the extent and position of heterotopic bone, and any intra-articular
incongruency. Preoperative ulnar, radial, and median nerve function tests are
performed as a routine procedure. The ulnar nerve is especially vulnerable
when a lack of flexion has persisted for a prolonged period.
Timing of Surgery
All conservative methods of treating restricted elbow mobility should be
attempted before operative procedures are carried out. Prior and subsequent
physiotherapy should be evaluated by a specialized physiotherapist. Only after
a directed course of regular physiotherapy has failed to improve function
should an operative intervention be planned. Indications for operative
treatment are a lack of motion of the dominant extremity and a total range of
movement of <100°, including a flexion deficit. The timing of the
procedure depends on the previous treatment. When stiffness persists despite
adequate physiotherapy, early elective intervention is advisable. However,
when there is heterotopic ossification with limitation of the joint gliding
spaces, we advocate a delay to allow the ossification to mature. In our
experience, it has been possible to remove heterotopic bone at the elbow joint
as early as three months after the injury.
Devices
For intraoperative distraction of the humeroulnar joint, a temporary,
strong fixator with distraction capacity is used to achieve sufficient joint
separation to lengthen the periarticular soft tissues. A standard dynamic
axial fixator (DAF; Orthofix, Verona, Italy) with a standard clamp for the
humeral pins and a T-clamp for two proximal ulnar pins is used for patients
older than fourteen years, whereas a monolateral wrist fixator (Pennig
II-Dynamic Wrist Fixator; Orthofix) with a built-in distractor with a T-clamp
is employed for younger patients. For mobilization of the elbow under moderate
distraction of the joint space and correction of axial malalignment, a
monolateral external fixator with motion capacity is used. In children younger
than thirteen years old, smaller pediatric hinges are used. The fixator
consists of two separate slotted bars, which can be connected on one side to a
fixator clamp. The bars overlap each other and a central screw passes through
the slots of both bars, thus allowing free movement of one against the other
until the central connecting unit is tightened by the surgeon. The central
connecting unit consists of a central locking screw and two additional
link-locking screws that allow the surgeon to fix the position of the central
unit at the center of elbow rotation in each fixator bar independently.
Locking of both of the link-locking screws results in a hinged movement
between both fixator bars corresponding to elbow flexion and extension,
whereas further locking of the central screw serves to immobilize the
humeroulnar joint (Fig. 1).
Operative Procedure
The operation is performed with the patient under general anesthesia and
without the use of a tourniquet.
CRITICAL CONCEPTSINDICATIONS:Posttraumatic stiffness of the elbow in children eleven years of age or
olderChronic posttraumatic subluxation of the elbowAssisted mobilization following reconstructive procedures about the
elbowCONTRAINDICATIONS:Previous infection of the elbow jointPoorly controlled diabetesHIV infectionyPoor compliancePITFALLS:The described technique is demanding, and special experience with the use
of external fixation is mandatory to perform the surgery, as is a dedicated
pin-site-care team and close collaboration with a physiotherapy unit trained
in hand therapy and pediatric physiotherapy.Intraoperative and postoperative observation of nerve status, especially of
the ulnar nerve, is of utmost importance in order to avoid iatrogenic
injury.Clear intraoperative radiographic visualization of joint distraction and
joint congruency is important to avoid iatrogenic subluxation of the
joint.AUTHOR UPDATE:In children older than thirteen years of age, exposure of the ulnar nerve
is now routinely performed to monitor it during distraction. The mechanical
distraction procedure and postoperative therapy have not changed.
CRITICAL CONCEPTS
INDICATIONS:
Posttraumatic stiffness of the elbow in children eleven years of age or
olderChronic posttraumatic subluxation of the elbowAssisted mobilization following reconstructive procedures about the
elbow
Posttraumatic stiffness of the elbow in children eleven years of age or
older
Chronic posttraumatic subluxation of the elbow
Assisted mobilization following reconstructive procedures about the
elbow
CONTRAINDICATIONS:
Previous infection of the elbow jointPoorly controlled diabetesHIV infectionyPoor compliance
Previous infection of the elbow joint
Poorly controlled diabetes
HIV infectiony
Poor compliance
PITFALLS:
The described technique is demanding, and special experience with the use
of external fixation is mandatory to perform the surgery, as is a dedicated
pin-site-care team and close collaboration with a physiotherapy unit trained
in hand therapy and pediatric physiotherapy.Intraoperative and postoperative observation of nerve status, especially of
the ulnar nerve, is of utmost importance in order to avoid iatrogenic
injury.Clear intraoperative radiographic visualization of joint distraction and
joint congruency is important to avoid iatrogenic subluxation of the
joint.
The described technique is demanding, and special experience with the use
of external fixation is mandatory to perform the surgery, as is a dedicated
pin-site-care team and close collaboration with a physiotherapy unit trained
in hand therapy and pediatric physiotherapy.
Intraoperative and postoperative observation of nerve status, especially of
the ulnar nerve, is of utmost importance in order to avoid iatrogenic
injury.
Clear intraoperative radiographic visualization of joint distraction and
joint congruency is important to avoid iatrogenic subluxation of the
joint.
AUTHOR UPDATE:
In children older than thirteen years of age, exposure of the ulnar nerve
is now routinely performed to monitor it during distraction. The mechanical
distraction procedure and postoperative therapy have not changed.
In patients with preoperative motor and sensory compromise and in those
with a severe flexion deficit, in situ decompression and neurolysis of the
ulnar nerve is performed after a curved incision is made over the cubital
tunnel (Fig. 2). The wound is
left open in order to monitor the position of and tension on the ulnar nerve
during the subsequent distraction phase and with flexion under joint
distraction. The wound is closed at the end of the operation. When there are
osseous fragments in the fibroosseous canal of the ulnar nerve they should be
removed cautiously. Transposition of the ulnar nerve as a routine procedure is
not recommended.
With the shoulder in internal rotation, the elbow is then placed on the
medial side. It should be supported by a rolled towel so that a true lateral
image of the elbow can be obtained with the image intensifier. On a true
lateral image, the radial and ulnar epicondyles overlap and the capitellum and
trochlea combine to form an oval structure in children and a ring structure in
adolescents and adults. The tip of a 2-mm Kirschner wire is placed on the
proximal border of this oval or ring and is drilled through the lateral
condyle parallel to the x-ray beam (Fig.
3). Provided that the entry point is at the proximal edge of the
circle, the wire can then be bent until the part protruding from the skin is
parallel to the axis of rotation and appears as a dot on the image-intensifier
screen. This obviates the need to reposition the wire.
Placement of the Humeral Pins
With the Kirschner wire in the correct position, the elbow fixator is slid
over it and is used as its own template to position the humeral link
externally and the ulnar link on the medial side
(Fig. 1). The landmark for the
humeral screws is the insertion of the deltoid muscle on the lateral aspect of
the bone. An open lateral exposure is recommended to avoid damage to a
dorsally positioned radial nerve. The screws are inserted through screw guides
mounted in the fixator clamp after predrilling with the correct-diameter drill
bit through a guide. Positioning of the fixator screws must allow for the
subsequent distraction maneuver. The humeral link should allow a minimum of 15
mm of distal sliding of the central hinge unit. The dimensions of the bone
screws are chosen according to the diameter of the humerus (5 to 6-mm conical
screws with predrilling to 4.8 mm are used in adolescents, and 3.5 to 4.5-mm
conical screws with predrilling to 3.2 mm are used in children).
Placement of Ulnar Screws
With the forearm in neutral rotation, the ulnar bone screws are inserted
from the dorsal direction between the proximal end and the midpart of the
ulnar shaft, in the center of the bone axis. Again, open insertion is
recommended, and both screws must penetrate the medullary canal of the ulna
for bicortical purchase. The conical thread diameter used for the ulnar screws
is 3.5 to 4.5 mm after predrilling with a 3.2-mm drill bit. Correct
penetration of the far cortex by both humeral and ulnar screws is confirmed by
fluoroscopy.
Application of the Distraction Fixator
The humeroulnar fixator is removed, and two temporary screws are inserted
into the posterolateral aspect of the olecranon for application of the
distraction fixator (Fig. 4). A
standard dynamic axial fixator armed with a standard compression-distraction
unit with a standard clamp for the humeral pins and a T-clamp for the
olecranon is used for patients older than fourteen years of age
(Fig. 5,a and
5,b), and a monolateral wrist fixator with a built-in
distractor with a T-clamp is employed for younger patients
(Fig. 5,c). The ideal
screw position is at the base of the coronoid process. More distal insertion
of fixator screws is not advisable because of the risk of producing fractures
in the ulna during distraction of the stiff elbow joint. Again, 3.5 to 4.5-mm
conical screws are recommended, and correct positioning is confirmed
radiographically.
The humeroulnar joint is slowly distracted over a period of ten to fifteen
minutes up to a distraction distance of 12 mm with use of an Allen key and the
compression-distraction unit of the built-in distraction unit. The distractor
is removed after achievement of the desired distance, as measured by the acute
loss of length in the calibrated telescope of the fixator. Acute loss of
distraction can amount to 50% to 60% of the initial effort. In such cases, a
second distraction is performed and is maintained for ten to fifteen minutes.
Final distraction is confirmed with a lateral radiograph
(Fig. 5 [insert]).
Application of the Articulated Elbow Fixator
After the second distraction phase, the distraction fixator is removed
along with the temporary olecranon screws, and the articulating elbow fixator
is mounted. The humeral fixator clamp is tightened first, 2 cm from the skin.
Then the ulnar clamp screws are tightened while the surgeon makes certain that
the Kirschner wire in the central unit has not been bent by the weight of the
fixator. The central unit locking nut is then tightened, followed by the
humeral and ulnar link-locking screws. Finally, the ball joints are tightened.
Before the joint is distracted for a third time, the Kirschner wire is
removed. After the link screw of the humeral link is opened, distraction up to
twice the normal joint space (5 to 6 mm) is performed with use of the small
distractor on the humeral link of the fixator
(Fig. 6, arrow)
(Table I).
Supplementary Measures
The computed tomography scan, in addition to conventional radiographs,
reveals information regarding the presence and location of osteophytes.
Relevant osteophytes at the olecranon or coronoid process and accompanying
heterotopic bone in the olecranon and coronoid fossa are removed through
limited
incisions10,11.
Congruent reduction and full extension cannot be expected unless impinging
heterotopic bone is removed. This also holds true for the anterior part of the
humeroulnar joint. Removal of osteophytes or heterotopic bone is performed
after distraction of the joint.
Mobilization of the Elbow
After the final distraction, pressure is carefully applied to the
mid-forearm region, while care is taken to avoid an excessive flexion load on
the ulnar pin group; the range of flexion and extension is gradually
increased. The distraction maneuver separates the articulating surfaces,
unloads the cartilage and avoids the delivery of excess force to the joint. A
controlled gain in flexion can be achieved with the compression-distraction
device (Fig. 7). An extension
deficit is addressed carefully in a similar manner. If there has been a
long-standing extension deficit of >40°, the possibility that the
radial and median nerves and the brachial artery have been shortened must be
considered as it is important to avoid neurapraxia or tension-induced spasm or
stenosis of the vessel during extension. The extension gain should be not more
than 30° to 50° during the operative procedure; a continuous slow
decrease in the extension deficit with use of a compression-distraction unit
is advisable postoperatively (Fig.
8). Monitoring of the distal radial pulse and digital pulse
oximetry are always performed. In most cases, a flexion deficit is the
relevant problem and visual control of the ulnar nerve is necessary during
intraoperative flexion. At the end of the operation, the humeroulnar fixator
is locked in 110° to 120° of flexion. The status of the ulnar nerve is
assessed directly after the operation, in the recovery room. Any motor
impairment or sensory disturbance is resolved by reducing flexion. Monitoring
of nerve function is of major importance, and therefore pain control with a
continuous brachial plexus block is not recommended.
Postoperative Management
The elbow joint is held in the desired position of flexion for at least six
days and for up to ten days if the deficit has been long-standing. Joint
distraction is maintained by the small distractor units, and elbow motion is
started by unlocking the screw of the central unit. Postoperative
physiotherapy is of utmost importance and is performed twice a day. Increased
flexion is achieved with the compression-distraction unit by applying 2 to 4
mm of compression every thirty minutes between physiotherapy sessions. This is
a slow and continuous process that leads to a gradual gain in flexion. The
second session of physiotherapy is scheduled as late as possible in the day,
after which the fixator is locked for the night, first in maximum flexion and
then, on the following night (after a focus on flexion during the day), in
maximum extension. This night immobilization, alternating between maximum
flexion and maximum extension, is carried out for at least three weeks and
leads to stepwise gains in both flexion and extension. This is followed by
physiotherapy with the same protocol, but without locking of the fixator at
night. In order to avoid formation of heterotopic ossification and to reduce
pain, indomethacin (25 mg twice a day) is prescribed for the total treatment
period.
A postoperative radiograph in two planes documents the distraction; for an
unobstructed lateral view, we use a dental film placed between the skin and
the fixator. Radiographic follow-up is scheduled for two, four, six, and eight
weeks postoperatively. The duration of external fixation ranges from six to
eight weeks, with the treatment protocol being adjusted according to the
individual progress of elbow function. Because of the importance of flexion to
elbow function, our treatment emphasizes it. A persistent extension deficit is
more readily compensated for by the patient. Removal of the fixator is always
performed as an outpatient procedure. Physiotherapy is continued for at least
one year after the distraction arthroplasty.