The purpose of the present report is to describe the case of a patient in
whom a trial femoral head displaced and migrated into the abdomen during a
total hip arthroplasty performed with a small incision. We also propose a
simple technique to help to prevent such an occurrence.
Asixty-four-year-old woman with symptomatic osteoarthritis underwent a
right total hip arthroplasty (Fig.
1). The patient was 5 ft (152.4 cm) tall and had a body mass index
of 23.4 kg/m2. After a discussion with her, we proposed a
mini-incision total hip arthroplasty and she accepted. The patient was
informed that data concerning the case would be submitted for publication.
With the patient in the lateral decubitus position, an 8-cm anterolateral
incision was used to expose the proximal part of the femur and the acetabulum.
The Accolade total hip system (Stryker Howmedica Osteonics, Allendale, New
Jersey) was used. Following the placement of the acetabular component, the
proximal part of the femur was broached and the largest broach that conferred
stability was left in place for a trial reduction of the components. A modular
trial femoral head was then placed on the trunion of the broach with what was
thought to be a secure fit. The broach-head construct was reduced into the
acetabular cup. There was a good range of motion without impingement, and the
hip was stable. During dislocation of the trial femoral head from the cup, the
head became disengaged from the broach and disappeared anteriorly into the
soft tissue beneath the rectus femoris muscle. Several unsuccessful attempts
were made to retrieve the trial head, first by hand and then with use of a
large Kelly clamp to dissect along the anterior column of the acetabulum over
the inner table of the pelvis. However, the small size of the incision made it
difficult to obtain sufficient exposure to capture the head. The original
incision was then extended 5 cm, 3 cm proximally and 2 cm distally. Even with
enlargement of the surgical field, additional attempts to retrieve the head
were unsuccessful. At that point, we decided to complete the total hip
arthroplasty.
At the conclusion of the procedure, the trial head was no longer palpable.
In the recovery room, a plain radiograph of the abdomen and pelvis did not
show the location of the radiolucent trial component. A computed tomography
examination of the abdomen revealed that the trial femoral head was lying on
the anterolateral side of the abdominal cavity
(Fig. 2).
On the first postoperative day, the patient complained of pain in the right
and left lower abdominal quadrants. Examination revealed mild tenderness and
guarding of both lower abdominal quadrants. A general surgery consultation was
obtained, and the general surgeon recommended laparoscopic removal of the
trial femoral head. With use of standard periumbilical portals, a
hemoperitoneum and a small abdominal wall defect in the right lower quadrant
were found, but there was no bowel damage. The trial femoral head was removed
without complication. The patient was able to walk on the second postoperative
day. One month after surgery, the patient was doing well with no abdominal or
hip symptoms.
Disengagement and migration of a trial femoral head is a rarely reported
complication of total hip
arthroplasty1,2.
The use of a small incision approach for hip arthroplasty may lead to an
increased prevalence of this complication because of the limited size of the
surgical field.
With repeated sterilizations, the fit between the trial femoral head and
the trunion of the broach or the actual femoral prosthesis deteriorates. It is
imperative to check the fit of the trial femoral head on the broach when
trials of different components are attempted. In our patient, the fit was
thought to be secure prior to the reduction and trial of the different trial
femoral heads.
The original size of the operating field in our patient limited the range
of maneuvers that we could exploit to capture the migrated trial femoral head.
Once the head had migrated, extension of the surgical wound was of little
value. The trial femoral head was readily movable, but its direction could not
be controlled and it displaced further with light touch.
In a previous case report, Batouk et al. described a trial femoral head
that had disengaged and migrated into the abdominal cavity and the patient had
elected to leave it in the abdominal
cavity1. The patient
was an eighty-one-year-old man who had sustained a subcapital fracture of the
femoral neck. The advanced age and medical status of the patient were cited as
reasons to leave the trial femoral head in place. In our patient, the trial
femoral head was removed because she had abdominal signs and symptoms.
Additionally, although the trial femoral heads are made of an inert acetyl
copolymer resin, there is a theoretical risk that this foreign body would
erode into the gastrointestinal tract.
Since the occurrence of this complication, we have developed a technique
that we believe will prevent the dislocation and migration of trial femoral
heads. The technique consists of threading two number-2 heavy sutures through
the dome holes of the trial femoral heads and securing the loop with a
figure-of-eight knot, thus creating a "necklace" of trial femoral
heads (Figs. 3-A through 3-D).
The sutures do not prevent impaction of the trial femoral heads on the trunion
bearing of either the broach or the femoral prosthesis, and they allow for
easy, safe removal of the trial femoral head if it becomes disengaged from the
broach. This technique is readily available, adds no extra time to the
procedure, is inexpensive, and is applicable to any surgical approach. We now
use this technique in all total hip arthroplasties to facilitate retrieval in
the event that a trial head is lost in the soft tissues.
We have used this technique in 112 patients who underwent total hip
arthroplasty. To date, no trial femoral head has displaced, so there has been
no instance for in situ testing of the strength of the "necklace."
We considered a cadaver study to test this technique, but the tissue in a
cadaver is not as pliant as the tissue in a live patient, and we believe that
it would be difficult to draw appropriate conclusions from such a study. A
theoretical problem with use of a suture, albeit a strong one, is that the
suture may be cut by a sharp metallic edge of the trunion of the broach or the
prosthesis.
The merit of this technique is that it may enable the atraumatic retrieval
of a displaced trial femoral head. Attempts to retrieve the head with fingers
or clamps only serve to displace it farther. Retrieval should be possible
regardless of the surgical approach, size of the incision, or prosthetic
design. We believe that this technique would have prevented the problem in our
patient, and we hope it will be of value to others. ?