The cases of forty-seven patients who underwent a total of fifty-one
stabilized anterior subcutaneous transpositions from 1973 to 1995
were retrospectively reviewed after a minimum of two years of follow-up.
At the latest follow-up evaluation, all patients were interviewed
and examined by one of three surgeons (B. T. B., O. A. B., or P.
F. T.) who had not been directly involved in the treatment of the
study patients. The patients were divided into two groups on the
basis of whether the elbow had been immobilized postoperatively
or an immediate range of motion had been begun. The patients were
naturally divided into these two groups when the senior author (R.
G. E.) and the other author whose patients were included in the
study (S. Z. G.) ceased to utilize any postoperative immobilization.
The latter author discontinued the use of postoperative immobilization
at a later time than the former. This explains the somewhat longer
average duration of follow-up for the patients treated with immobilization.
Group I consisted of twenty patients with twenty-one elbows that
were immobilized postoperatively for two to three weeks in a long
arm cast. There were fourteen male patients and six female patients
with an average age of 39.9 years (range, seventeen to sixty-eight
years). The duration of follow-up averaged 6.6 years (range, two
to thirteen years). Fifteen (71 percent) of the twenty-one procedures
were performed in the dominant extremity. Two patients were involved
in Workers' Compensation cases.
Group II consisted of thirty elbows in twenty-seven patients
who began an active range of motion in the immediate postoperative
period. There were fifteen men and twelve women with an average age
of 46.5 years (range, nineteen to eighty-two years). The duration
of follow-up for this group averaged 4.9 years (range, two to fourteen
years). Seventeen (57 percent) of the thirty procedures were performed
in the dominant extremity. Three patients were involved in Workers'
Compensation cases.
The diagnosis of cubital tunnel syndrome was made primarily on
the basis of a complete history and physical examination. Symptoms
included some combination of pain in the elbow and hand, paresthesias
affecting the hand and forearm, weakness of grip and pinch, and
loss of hand dexterity. Typical physical findings included combinations of
decreased sensibility to light touch and two-point discrimination
in the ulnar nerve distribution, hypothenar wasting, diminished
pinch and grip strength as measured with a calibrated grip dynamometer
and a pinch gauge, a Tinel sign at the cubital tunnel, and a positive
elbow flexion test. The percentages of patients with each of the findings
are listed in Table I.
Corroborative electrodiagnostic studies were not found in the retrospective
chart review for eleven (22 percent) of the fifty-one elbows. Preoperative radiographs
of the involved elbow (and the cervical spine when indicated) were
required for all patients. In forty patients (forty-four elbows),
the cause of the cubital tunnel syndrome was nonspecific. An elbow
fracture was the cause in five of the remaining seven elbows, and
blunt trauma was the cause in two; these cases were essentially equally
divided between the two study groups.
All patients were initially managed with a standard nonoperative
treatment regimen, which included one or more courses of anti-inflammatory
medication, extension splinting of the elbow, and activity modifications
for at least six weeks. The indication for surgery was a diagnosis
of cubital tunnel syndrome that persisted despite nonoperative treatment
modalities.
Surgical Technique
All of the procedures were performed by one of the two senior
authors (R. G. E. or S. Z. G.). The technique originally described
by Eaton et al.2 was utilized
in all patients (Fig. 1-A, Fig. 1-B, Fig. 1-C, Fig. 1-D, and Fig. 1-E). With the patient supine and under
regional anesthesia, a tourniquet is placed high on the brachium. The
medial epicondyle is marked as a reference point on the elbow, which
is flexed to 45 degrees. At a point one to one and one-half centimeters
anterior to the medial epicondyle, a second mark is made to indicate
where the fascial sling will be sutured to the deep dermis because
once the incision is made the skin retracts, distorting the reference points.
After exsanguination with an Esmarch bandage, a curvilinear ten-centimeter
incision is made midway between the epicondyle and the olecranon.
In the deep layer of subcutaneous tissue, one or more branches of
the medial brachial and antebrachial cutaneous nerves are variably
located, and they must be preserved during the blunt dissection.
The ulnar nerve is readily palpable proximal to the cubital tunnel,
where it lies posterior to the medial intermuscular septum. As the
nerve is dissected distally, care must be taken to retain the accompanying
longitudinal venae comitantes, thereby preserving critical longitudinal
blood supply to the nerve, especially since certain small segmental vessels
must be sacrificed to allow for anterior transposition of the nerve.
Attempts to preserve as much of the segmental blood supply as possible should
be made. Nestled under the posterior aspect of the intermuscular
septum is a plexus of veins, which should be dissected from the
septum prior to its excision or cauterized. Approximately three centimeters
of the distal septum should then be excised.
At times, a focal constriction of the nerve within the cubital
tunnel may be found; if it is, any superficial fibrotic epineurium
can be teased apart to relax the constriction. The clinical efficacy
of doing so is not known, however. We never perform an internal
neurolysis. Once the transverse retinacular fibers forming the fascial
roof of the cubital tunnel have been released, dissection is carried distally
to the level at which the nerve enters the flexor carpi ulnaris.
At or distal to this hiatus between the humeral and ulnar heads
of the flexor carpi ulnaris, a transverse arc of fascia may be found
and should be divided. Care must be taken to preserve the small
motor branches at the proximal aspect of the flexor carpi ulnaris
muscle origin. The fascia and muscle are split at a sufficient distance
to prevent the creation of more than a 45-degree angle in the transposed
nerve when the elbow is extended. As the nerve is mobilized and
is moved from its native position to its transposed position, one
must avoid any traction on it. To this end, we prefer to use a broad
Penrose drain to minimize focal pressures on the nerve.
The fascia overlying the flexor-pronator origin is cleared of
adherent subcutaneous tissue, and a one and one-half-centimeter-wide
and two-centimeter-long fascial flap based at the tip of the medial
epicondyle is elevated from the muscle. If any vertical intermuscular
septae are present, they are released to eliminate any sharp edges
upon which the nerve will ultimately rest. No trough is made across
the flexor-pronator mass. The nerve is transposed, and the fascial
sling is sutured to the sturdy deep dermal tissue with 3-0 absorbable
suture. With the skin stretched back toward its original position,
the position of the nerve and its fasciodermal sling is evaluated
through the full arc of elbow motion. Adjustments in the dermal
attachment are rarely necessary. The subcutaneous tissue is closed
with absorbable suture followed by a subcuticular closure reinforced
with Steri-Strips (3M, St. Paul, Minnesota). A soft mobile dressing is
placed about the elbow, and a sling is provided for comfort.
Postoperatively, all patients are instructed to begin gentle,
progressive use of the involved upper limb as tolerated, including
an active range of motion, activities of daily living, and the playing
of musical instruments. Patients are instructed to avoid forceful
use of the involved arm, including manual labor, heavy lifting,
and sports involving such use of the upper limb, until six weeks
after the surgery, at which time all activity restrictions are eliminated.
Patient Assessment
Follow-up evaluation of the patients at a minimum of two years
consisted of a complete reexamination and completion of a questionnaire
that asked for subjective determinations of satisfaction and functional
outcome. The same parameters that were listed as the indications
for surgery were reassessed to determine if the surgery had led
to a resolution of these problems. Satisfaction, willingness to
undergo the procedure again or to recommend the procedure to others,
and the number of days until the patient returned to work were all documented.
Preoperative staging of the severity of the cubital tunnel syndrome
was performed with Dellon's staging criteria1.
The final outcome was graded according to the Bishop rating system8. This demerit point system assesses
the clinical parameters of patient satisfaction, strength, sensibility,
residual symptoms, improvement, work status, and leisure activity
(Table II).
All statistical analyses were performed with the Statistical
Package for the Social Sciences (SPSS for Windows, version 5.02;
Chicago, Illinois, 1993). In order to avoid dependency in the data, the
four patients who had had bilateral elbow surgery were not included
twice in the analyses. Instead, one of the elbows was randomly chosen. Data
are presented as averages and standard deviations for continuous
variables and as numbers and percentages for nominal variables.
The Student t test was used to assess differences between the two
groups with respect to continuous measures. Differences between
the two groups with respect to categorical measures were tested
with chi-square analysis or the Fisher exact test if the expected
number of subjects in any cell was less than five. P values of 0.05
or less were considered significant.
In order to evaluate one of the primary study outcomes (the time
until the patient returned to work), sample-size calculations were
based on a clinically relevant difference of two weeks between the group
treated with immobilization and the group treated with immediate
mobilization of the elbow. With twenty-two patients in each group,
it was found that this study would have sufficient power (85 percent)
to detect this difference at a = 0.05.
Group I (immobilization for two to three weeks postoperatively
in a long arm cast) and Group II (active range of motion begun in
the immediate postoperative period) were equivalent with respect to
gender, age, whether the dominant extremity was affected, and preoperative
severity of the cubital tunnel syndrome. The duration of follow-up in
Group I was 1.7 years longer than that in Group II (p = 0.025),
for the reasons discussed above.
The various features of the neuromuscular evaluation are presented
in Table I.
With the numbers available, no significant differences between the
two groups could be found.
Preoperative severity of cubital tunnel syndrome: According
to Dellon's criterial, the cubital
tunnel syndrome was classified as mild in eight of the twenty-one
Group-I elbows, as moderate in four, and as severe in nine. Similarly, the
cubital tunnel syndrome was classified as mild in fourteen of the
thirty Group-II elbows, as moderate in seven, and as severe in nine.
In the overall group of fifty-one elbows, the cubital tunnel syndrome
was classified as mild in 43 percent, as moderate in 22 percent,
and as severe in 35 percent.
Paresthesias: Of the twenty-one elbows in Group
I, seventeen were associated with substantial preoperative paresthesias
in the ulnar nerve distribution. Postoperatively, the paresthesias
had resolved completely in fourteen of the seventeen limbs and the
remaining three had occasional, mild paresthesias. One of these
three remained essentially unchanged from the preoperative status.
In Group II, twenty-nine of the thirty elbows were associated with
preoperative paresthesias. Postoperatively, the paresthesias had
resolved completely in twenty-four of the twenty-nine limbs whereas
the remaining five still had some paresthesias. Two of these five
had no change from the preoperative status. No patient who had been
free of paresthesias preoperatively complained of paresthesias postoperatively.
Weakness: In Group I, sixteen of twenty affected
limbs were said to be subjectively weak by the patients before the
surgery and four felt weak postoperatively. In Group II, nineteen
of twenty-seven affected limbs were felt to be weak preoperatively
whereas five were said to be weak postoperatively. With the numbers
available, the percentages of the affected limbs reported to be
weak, either preoperatively or postoperatively, did not differ significantly
between the two groups. Moreover, the percentages of preoperatively
weak limbs that were reported to be weak postoperatively did not
differ significantly between the two groups. Approximately half
of the patients in each group reported no change in subjective weakness
between the preoperative and postoperative examinations.
Objective strength: In Group I, average grip
strength increased from twenty-nine kilograms-force (range, 9.1
to 54.5 kilograms-force) preoperatively to 33.1 kilograms-force
(range, 11.3 to 56.8 kilograms-force) postoperatively, an increase
of 14 percent. Average pinch strength increased from 5.4 kilograms-force (range,
2.3 to 9.1 kilograms-force) to 6.5 kilograms-force (range, 3.2 to
ten kilograms-force), an increase of 20 percent. In Group II, average
grip strength increased from 28.6 kilograms-force (range, 5.5 to
52.3 kilograms-force) to 32.7 kilograms-force (range, 11.4 to 52.3
kilograms-force), an increase of 14 percent, whereas average pinch strength
increased from 5.5 kilograms-force (range, 0.5 to 10.5 kilograms-force)
to 7.0 kilograms-force (range, 1.4 to 10.5 kilograms-force), an
increase of 27 percent. The groups did not differ significantly
with regard to objective strength.
Range of motion: In Group I, all twenty-one
elbows exhibited a full range of motion, with no change between
the preoperative and final follow-up values. In Group II, only two
of the thirty elbows did not have a full preoperative and postoperative
range of motion. One elbow had sustained temporally distant trauma,
and the range of motion was the same, albeit reduced, both preoperatively
and postoperatively. One of the two patients involved in a Workers' Compensation
claim had a 20-degree loss of terminal extension and a 10-degree
loss of total motion for unknown reasons during an unremarkable postoperative
course.
Sensibility: Two-point discrimination was considered
abnormal if it was greater than six millimeters. Six of sixteen
affected limbs in Group I and ten of twenty-four in Group II exhibited
abnormal two-point discrimination preoperatively. At the time of
the most recent follow-up, four of the twenty-one affected limbs
in Group I remained abnormal with regard to two-point discrimination,
which averaged 7.75 millimeters (range, seven to eight millimeters).
In Group II, five of the thirty limbs remained abnormal with regard
to two-point discrimination, which averaged 9.4 millimeters (range,
seven to thirteen millimeters). Thus, in both groups, two-point
discrimination was normal postoperatively in more than 80 percent
of the limbs. Only 6 percent (three limbs) exhibited greater than
eight millimeters of two-point discrimination.
Provocative maneuvers (Tinel sign and elbow flexion test): Preoperatively,
sixteen of the twenty-one affected limbs in Group I had a positive
Tinel sign at the elbow compared with twenty-four of the thirty
limbs in Group II. Postoperatively, a positive Tinel sign was found
in seven limbs in Group I and in nine in Group II, but it was only
mildly positive in the majority of cases. There was no significant
difference between the groups with regard to the proportion of patients
who had a positive Tinel sign either preoperatively or postoperatively.
No elbow in either group had a positive elbow flexion test at the time
of the most recent follow-up.
Patient satisfaction: All patients were asked
if they were satisfied with the result and whether they would agree
to undergo the procedure again given the same circumstances. The
patients were satisfied with the result for nineteen of the twenty-one
affected limbs in Group I and for twenty-seven of twenty-nine in
Group II.
Return to work: All patients in the study returned
to their previous occupation except for one in Group I. The patients returned
to work at an average of 29.8 5.3 days (range, two to ninety-nine
days) in Group I and at an average of 9.6 3.3 days (range, zero
to sixty days) in Group II (Fig. 2). This difference was highly significant
(p = 0.002). Seven of twenty-one patients in Group II actually returned
to work on the morning following the surgery, whereas none of the
patients in Group I did so.
Bishop ratings: The surgical results were graded as excellent,
good, fair, or poor with use of the Bishop 12-point rating system8 (Table II). In Group I, sixteen of the results
were rated as excellent; three, as good; none, as fair; and two,
as poor. In Group II, twenty-one results were rated as excellent;
six, as good; two, as fair; and one, as poor.
Our results are consistent with those reported by other authors
after use of a similar subcutaneous ulnar nerve transposition14,18,22 as well as after use of other
techniques1,6,8,10-13,16-18. From
this point of view, the primary information provided by our study,
in which there was a longer-term (minimum two-year) follow-up, is
that the results of subcutaneous transposition do not deteriorate
over time. While most cases of cubital tunnel syndrome resolve within
one year after surgery, Leffert's series included two patients with grade-II
neuropathy (that is, neurological deficits) who did not achieve
their final functional outcome until fifteen months and two years
postoperatively10.
Although most reports reviewed by us6-10,12-14,16-18,20,21,23,24 described
the postoperative regimens, few included the amount of time until
the patients returned to work or to unlimited activities. Presumably
because of a paucity of comparative data, this was not a category
in the comparison of outcomes compiled by Dellon1.
In McGowan's seminal report on forty-six cases of cubital tunnel
syndrome treated with anterior transposition, the nerve was transposed
subcutaneously in forty-two cases whereas a submuscular position
was used in four patients with little subcutaneous fat11. Unfortunately, McGowan made no
mention of a specific postoperative protocol, and while he did mention
the patients' return to their previous occupation he did not report
the time until this occurred.
In a recent review of the results of subcutaneous ulnar nerve
transposition, Osterman and Davis did not mention postoperative
protocols or return to activities14.
Rettig and Ebben reported on a group of athletes at various competitive
levels who had been treated with subcutaneous ulnar nerve transposition18. The elbows were immobilized at
90 degrees for ten days, and the patients were allowed to return
to sports as tolerated at six weeks. The average time until the
patients returned to full activities was 12.6 weeks.
This protocol paralleled that described by Eaton et al. in their
original report on sixteen patients treated with subcutaneous transposition
stabilized with a fasciodermal sling2.
All of their patients, including the seven professional pitchers,
began active elbow motion after ten to fourteen days of immobilization.
Beginning in 1985, the senior author of the present study altered
his regimen to permit active elbow motion in the immediate postoperative
period. Since the operative technique itself remained unchanged,
this allowed for the relatively pure and unbiased comparison that
forms the core of the present study. A study very similar to the
present one was recently reported by Weirich et al.22. They reviewed the results for thirty-six
patients at a minimum of six months after treatment with the stabilized
anterior transposition procedure described by Eaton et al.2. The outcomes for twenty patients
who had had the elbow mobilized immediately and sixteen patients
who had had the elbow immobilized for an average of two weeks did
not differ in terms of clinical outcome but did differ significantly
with regard to the time until they returned to work and daily activities
(a median of one month and 2.75 months in the immediate-mobilization
and delayed-mobilization groups, respectively). It is unclear why
the forty-seven patients in the present study, who underwent essentially
the same operative procedure and postoperative regimen as the patients
in the study by Weirich et al., returned to work and daily activities
sooner (at an average of thirty and ten days in Groups I and II,
respectively).
To our knowledge, none of the previously described techniques
(medial epicondylectomy and submuscular and intramuscular transposition)
include the institution of immediate active elbow motion in the
postoperative protocol7,9,14,24.
Although Heithoff et al. allowed active elbow motion at ten to fourteen
days after medial epicondylectomy, they did not allow unrestricted
activity until three to six months later6,7.
In a comprehensive review, Osterman and Kitay summarized the postoperative
regimen as active motion at seven to ten days, progressive strengthening
at four weeks, and unrestricted activity by three months15.
Submuscular transposition seems to require similarly longer periods
until a return to unrestricted activities. Pasque and Rayan performed
a retrospective review of the cases of forty-eight patients who
had been treated with submuscular transposition16.
The elbows were immobilized for an average of five weeks postoperatively,
and the patients returned to full activities of daily living at
an average of six weeks.
In Leffert's report on forty-eight patients treated with a submuscular
transposition, as originally described by Learmonth, all patients
had the wrist, forearm, and elbow immobilized for three weeks10. No data regarding return to activities
or work were given. Nouhan and Kleinert reviewed the charts of thirty
patients treated with submuscular transposition followed by immobilization
for 2.5 weeks13. The time until
the patients returned to "light duty" averaged 2.5 months, and the
time until they returned to "regular duty" averaged 4.2 months.
In his review article on submuscular transposition, Siegel noted
that range-of-motion and forearm-strengthening exercises were begun
at six weeks20. However, except
for McGowan grades, no outcomes data were provided.
Few would disagree that medial epicondylectomy and submuscular
anterior transposition require more osseous or soft-tissue dissection
than the subcutaneous technique used in the present study. It is
not surprising, then, that the earliest return to activities of
daily living after those more extensive procedures is at six weeks
or that it takes more than four months for some patients to return
to full activities. While the clinical outcomes in our two study
groups were similar, the patients who had been treated with immobilization
returned to activities in an average of thirty days but those treated
with immediate motion returned in an average of ten days. These
results compare quite favorably with those of the above-mentioned
studies.
Anterior intramuscular transposition is the closest relative
of subcutaneous transposition and requires only a mild degree of
additional dissection to stabilize the nerve anteriorly9,15. In addition to providing a useful
postoperative rating system, Kleinman and Bishop reported the results
of their technique8. Their protocol
requires immobilization of the elbow in 90 degrees of flexion and
the forearm in 45 degrees of pronation for three weeks. Unrestricted activity
is begun at eight to ten weeks. This amount of time is still notably
longer than that required by our protocol.
The present study provided preoperative and postoperative outcomes
data at a minimum of two years for two groups of patients who underwent the
same operation but different postoperative regimens. The similarity
of the outcomes of the two groups except for the time until the
patients returned to work suggests that an immediate range of motion
offers an advantage and disrupts the workplace to a lesser degree.
The present study demonstrated that subcutaneous ulnar nerve transposition stabilized
with a fasciodermal sling engendered reliable results and high patient
satisfaction after follow-up of at least two years.