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Rehabilitation after subcutaneous transposition of the ulnar nerve: Immediate versus delayed mobilization
Rehabilitation ulnar nerve:
after subcutaneous transposition of the Immediate versus delayed mobilization
Samuel D. Weirich, MD, Richard H. Gelberman, MD, Sharon A. Best, MA, Sven-Olof Abrahamsson, MD, PhD, Deborah C. Furcolo, OTR, and Robert E. tins, MD,
Boston,
Mass., and
St. louis, MO.
We studied 36 patients who had clinical signs and symptoms consistent with cubital tunnel syndrome and in whom nonoperative management failed. These patients underwent anterior subcutaneous transposition of the ulnar nerve followed by either immediate (20 patients) or delayed (I 6 patients) mobilization. All patients were evaluated with an outcomes assessment questionnaire, and 35 of the 36 were given repeat physical examinations. After surgery, there were no significant differences between the two groups in pain relief, weakness, or patient safisfacfion (71% of the immediate mobilization group and 74% of the delayed group) were satisfied. Secondary quantitative outcomes such as grip strength, lateral pinch, or two-point discrimination were also not significantly different between the groups. Both groups had a statistically significant improvement in first dorsal interosseous and adductor pollicis muscle strength. In the immediate mobilization group, however, patients returned to work and resumed activities OF daily living earlier [median I month) than patients in the delayed mobilization group (median 2.75 months). Therefore, we conclude that anterior subcutaneous transposition provides a high degree of satisfaction and relief of symptoms regardless of when mobilization is initiated. However, immediately mobilizing the patient significantly influenced how early the patient returned to work and resumed activities of daily living. (J Shoulder Elbow Surg 7 998;7:244-9.)
Operative
decompression ment of an established elbow that is unresponsive
is the accepted treatulnar neuropathy of the to conservative therapy.
From the Departments of Orthopedic tional Therapy and the General ter-Biostatistics, Massachusetts ton; and the Department Washington University School
Surgery
Clinical
and
Occupo-
Research Cen-
General Hospital, Bosof Orthopedic Surgery, of Medicine, St. Louis.
Reprint requests: Richard H. Gelberman, MD, Professor and Chairman, Department of Orthopedic Surgery, Washington University, School of Medicine, St. Louis, MO63110. Copyright 0 1998 by journal of Shoulder and Elbow Surgery Board of Trustees. 1O.B2746/98/$5.00
244
+ 0
32/l/80678
Most techniques have been devised to relieve areas of compression, to minimize the potential of producing iatrogenic compression, and to promote normal neural gliding by locating the nerve in an unscarred and well-vascularized bed.* To our knowledge, the fasciodermal sling designed by Eaton et al.8 is the only technique that maintains the anterior position of the nerve while allowing early rehabilitation of the patient. Eaton’ suggested use of early mobilization to accelerate the rehabilitation process after surgery. The purpose of our study was to determine whether the timing of postoperative mobilization after transposition of the ulnar nerve influenced functional recovery. The advantages of early mobilization were anticipated to occur in the early period after surgery. We compared clinical results of immediate and delayed mobilization in a series of patients in whom nonoperative management of cubital tunnel syndrome failed. MATERIALS
AND
METHODS
Cubital tunnel syndrome was diagnosed in 36 patients on the basis of pain, numbness, paresthesias, and/or weakness in the ulnar nerve distal to the elbow. Ulnar nerve percussion and elbow flexion tests were used to establish the diagnosis. Electrophysiologic studies of the ulnar nerve were performed in all patients. In 32 patients results of electrophysiologic studies were positive, indicating a delay in conduction across the elbow, demonstrable, symptomatic subluxation of the ulnar nerve, or both. Four other patients who had normal electrophysiologic study results and no evidence of nerve subluxation underwent transposition because of prolonged characteristic symptoms and signs of cubital tunnel syndrome unresponsive to nonoperative treatment. The signs and symptoms included a positive ulnar nerve percussion test at the elbow, persistent diminished light touch sensitivity determined by monofilament testing, and abnormally increased two-point discrimination over the ulnar nerve sensory distribution. One patient
*References
5,
6, 8, 9,
1 1,
14,
15,
19,
25,
28.
J Shoulder Volume 7,
Elbow Number
Weirich
Surg
et al.
245
3
also exhibited mild intrinsic muscle wasting and motor weakness. From 1987 to 1994, conventional nonsurgical treatment failed in 42 patients, who underwent anterior subcutaneous transposition of the ulnar nerve and wore a noncompressing fasciodermal sling. All surgery was performed by Richard H. Gelberman, MD. Two patients were lost to follow-up, and one patient was excluded from the study because of an additional site of ulnar nerve compression. Two other patients
delayed grade
were excluded because they had other neurologic conditions: one patient had sympathetic mediated pain syndrome and the other had amyotrophic lateral sclerosis. Another patient was excluded because of advanced degenerative cervical spine disease and peripheral neuropathy. Hence our study population consisted of 36 patients divided in two groups. Group 1 consisted of 20 patients who had immediate postoperative mobilization after anterior subcutaneous transposition. The 16 patients in
of-motion (ROM) exercises that were initiated on the day of surgery. A 30” extension block splint was used until sutures were removed 8 to 10 days after surgery to decrease the tendency for the nerve to migrate posteriorly. The operated limbs of patients in group 2 were placed in well-padded plaster splints with the elbows flexed 90”. Immobilization of 7 to 30 days (mean 14.4 days) was followed by active and active-assisted ROM exercises. Postoperative evaluation. All patients were called
group 2 underwent mobilization after 7 to 30 days (mean 14.4). The mean age of patients in group 1 was 40.7 years (range 18 to 76 years), and the mean age in group 2 was 50.4 years (range 23 to 74 years). Group 1 had 5 women and 15 men, and group 2 had 5 women and 11 men. The dominant upper extremity was involved in 12 patients in group 1 and 13
for a follow-up evaluation. A standardized outcomes questionnaire was used to evaluate relief of pain, weakness, and paresthesias. Patients were asked when they were able to return to their normal daily activities or work duties without restrictions. Satisfaction with the operative results was rated on a scale of 0 to 10 with 0 representing total dissatisfaction and 10 representing complete satisfaction. This rating was multiplied by 10 to obtain a satisfaction scale percentage. Additional subjective parameters were evaluated. The outcomes questionnaire rated patients’ improvements in their abilities to perform five common activities of daily living (ADLs) and work capability after surgery [Table I). During the follow-up physical examination seven objective parameters were evaluated (Table II).
patients in group 2. One patient in group 1 was ambidextrous. Five (25%) patients in group 1 and 7 (43%) patients in group 2 were involved in workers’ compensation claims. One patient in group 1 moved out of our area and was unable to be examined. However, this patient completed the outcomes questionnaire. Complete follow-up was available for the remaining 35 patients 197% of the study population). months, and mean follow-up 66 months).
Minimum follow-up was 6 was 22 months (range 6 to
Preoperative assessment. A chart review was used to obtain preoperative patient information. Digital sensibility measurement was determined with the static twopoint discrimination and Semmes-Weinstein monofilament tests. Motor strength testing of the ulnar nerveinnervated forearm and hand muscles was performed and graded from 0 to 5 according to the American Orthopaedic Association muscle grading criteria.’ Grip strength was tested with the Jaymar Dynometer, (Asimov Engineering, Los Angeles, Calif.), and lateral key pinch strength was tested with Therapeutic Instruments, (Clifton, N.J.) in both hands. The severity of nerve involvement was graded at the time of operation by the McGowan19 classification systems. In those patients undergoing immediate mobilization (group l), 9 had grade I, 8 grade II, and 3 grade III involvement. In those patients whose mobilization was
(group 21, 6 had grade I, 9 grade II, and 1 III involvement. Operative method. Anterior subcutaneous transposition of the ulnar nerve was performed as originally described by Eaton et al.8 This technique has been modified to mobilize the ulnar nerve proximally for 10 cm to include the arcade of Struthers. The distal intermuscular septum is also resected for this length. Group 1 patients underwent ulnar nerve anterior subcutaneous transposition and immediate active range-
Outcomes analysis. Satisfaction after the operation and relief of pain, weakness, and paresthesias were considered primary outcomes criteria. Secondary outcomes criteria were categorized as qualitative and quantitative. Secondary qualitative outcomes determined the patient’s subjective functional improvement, the rapidity of returning to work, and the ability to perform ADLs. Secondary quantitative outcomes included assessment of electrophysiologic changes, pinch and grip strength, two-point discrimination, SemmesWeinstein quantitative tactile discrimination, and motor
strength
of the ulnar nerve-innervated muscle groups. Outcome variables were analyzed with an analysis of covariance; the baseline variable was used as a covariate. Analysis of Kaplan-Meier survivorship was used to compare return to work and function, and Fisher’s exact test was used for categoric values. A two-sided 0.05 significance level was used throughout. The quantitative variables are reported as mean and standard deviation. Statistics.
246
Weirich
et al.
J Shoulder
Elbow
May/June
Table
I Common
ADls
and
work
capabilities*
Sleeping Opening jars Picking up small objects (e.g., coins) Carrying a 1 O-pound object (e.g., l-gallon Resuming usual iob activities
Table
milk iug)
*As rated by patients.
RESULTS Study Population In the two study groups there were no significant differences in patient sex, age, hand dominance, involvement in workers’ compensation claims, or severity of ulnar nerve involvement as graded by the McGowan19 classification. Outcomes
Analysis
Primary outcomes. After anterior subcutaneous transposition, immediate mobilization resulted in a patient satisfaction rating of 71% and in delayed mobilization of 74%. This difference was not statistically significant. We were not able to find significant differences in relief of pain, weakness, or paresthesias between the two groups. Secondary outcomes-Qualitative. No statistically significant differences existed between the two groups; there was no significant improvement in their ability to perform five common ADLs and capability to work. Data about resuming ADLs for the two groups were plotted on a Kaplan-Meier curve (Figure 1). The median times to return to work for the immediate movement group was 1 month, and for the delayed movement group was 2.75 months. The log rank test showed a significant increase in return to work time for the patients treated with delayed movement (p = 0.04). Secondary outcomes-Quantitative. Preoperative grip strength values were 53 5 29 and 48 t 38 pounds for immediate mobilization (group 1; n = 16) and delayed mobilization (group 2; n = 151, respectively. After the operation mean grip strength improved to 7.5 i- 35 (n = 19) and 56 ? 35 (n = 16) pounds (Figure 2). No statistically significant improvements in either group or differences between groups were noted after the operation. Although lateral pinch strength measurements improved in both groups after surgery, the difference in values was not statistically significant. Mean lateral pinch strength values before surgery
II Physical
parameters
evaluated
after
Surg
7 998
operation
Two-point discrimination Semmes-Weinstein monofilament testing Grip and key pinch strength Medial epicondyle tenderness Positive elbow flexion test results Ulnar nerve sensitivity in the anteriorly transposed position Motor strength testing of ulnar nerve-innervated muscle groups Adductor pollicis First dorsal interosseous Abductor digiti quinti
were 14 t 9 and 12.5 +- 6.8 pounds in group 1 (n = 15) and 2 (n = 14), respectively, and after surgery were 18 t 7.1 and 14.3 + 6.8 pounds for groups 1 (n = 19) and 2 (n = 15), respectively, (Figure 3). Two-point discrimination was noted to improve within both groups after surgery but was not statistically significant. Mean two-point discrimination was recorded as 6.6 + 2.7 and 7.4 * 3.0 mm before surgery for groups 1 (n = 17) and 2 (n = 14), respectively, and 5.3 t 1.8 and 6.5 2 2.9 mm after surgery for group 1 (n = 19) and group 2 (n = 16), respectively (Figure 4). There was no significant improvement in the preoperative and postoperative Semmes-Weinstein monofilament testing values within either group or between groups (Figure 5). The mean muscle strength values of the first dorsal interosseous muscle before surgery were 4.2 2 1 .O and 3.9 +- 1.5 for groups 1 (n = 17) and 2 (IJ = 13) respectively, compared with postoperative values of 3.9 t 1.5 (n = 19) and 4.8 5 0.3 (n = 15) in groups 1 and 2, respectively. Statistically significant improvement was noted in both the immediate and delayed mobilization groups but was not noted when the two groups were compared. The mean preoperative muscle strength values for the adductor pollicis muscle were 4.5 + 0.9 and 4.6 + 0.7 for Groups 1 (n = 12) and 2 (n = 9), respectively, compared with 4.9 ? 0.3 (n = 19) and 4.9 2 0.3 (n = 15) after the operation. The improvement in muscle strength testing for the adductor pollicis muscle was statistically significant within the immediate mobilization group (p = 0.0102) and within the delayed mobilization group (p = 0.0410). However, no significant
Weirich
I Shoulder Elbow Surg Volume 7, Number 3
et al.
q =z
cl 0
10
247
Immediate
24
6
22 20
=ril
18
E
16
c,
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2
4
6
20
Months
Figure patients
1 Kaplan-Meier curve of time who did not return to ADls.
versus
percent
Preoperative
of Figure
q
3 Mean
values
for lateral
pinch
strength
Immediate
120 110
g
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10
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:
q
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Delayed
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Postoperative
2
2
P b
0 Preoperative
Figure
Postoperative
2 Mean
values
for grip
Postoperative
strength Figure
difference was noted in adductor pollicis muscle strength between the groups. Mean muscle strength testing values for the abductor digiti quinti muscle were 4.3 k 0.9 and 4.2 t 1.6 for the immediate (n = 13) and delayed mobilization (n = 9) groups before the operation, compared with 4.6 k 0.5 (n = 19) and 4.7 -t_0.4 (n = 15) for the two groups after the operation. Statistically significant improvement in abductor digiti quinti muscle strength testing was not encountered in either group or between groups. Both groups had similar postoperative occurrences of medial epicondyle tenderness (48% for group 1 [n = 191 and 50% for group 2 [n = 161) as well as the presence of ulnar nerve sensitivity in the transposed position (53% for group 1 [n = 181 and 53% for group 2 [n = 151). Positive postoperative elbow flexion test results were found in 16% in group 1 (n = 19) and 27% in group 2 (n =
4 Mean
values
for two-point
discrimination
15). Comparison of these values between groups revealed that neither constituted a statistically significant difference. Complications. There were no intraoperative complications in either the immediate or delayed mobilization groups. Five patients’ symptoms were exacerbated in the immediate postoperative period: three in the immediate mobilization group and two in the delayed group. One patient in group 1 continued to have significant symptoms for several months but reported improved symptoms at the last follow-up (7 months after transposition). The remaining four patients noted gradual resolution of symptoms. There were two superficial wound infections, both of which responded to treatment with oral antibiotics. Two patients in whom treatment failed required subsequent ulnar nerve procedures about the el-
248
Weirich
et al.
J Shoulder Elbow Surg May/June I998
q n
Preoperative Figure
ment
5 Mean testing.
values
Immediate Delayed
Postoperative for
Semmes-Weinstein
monofila-
bow. Revision surgery consisted of external neurolysis and submuscular transposition in both cases. Four additional patients were dissatisfied with their operative outcomes and would not have had the surgery if given the choice again. Of these six clinical failures, four were treated with delayed mobilization and two were treated with immediate mobilization. The failure rate between the two groups was not statistically significant. Data from the patients in whom treatment failed were included in the statistical analysis. DISCUSSION Longitudinal excursion between the epineurium of the peripheral nerve and its surrounding connective tissue bed has been shown experimentally to play an important role in the accommodation of nerve-to-joint motion.2, 22, 24, 29, 3o The gliding apparatus, which is composed of several layers of tissue surrounding the nerve, consists of alternating vascular and hypovascular layers of randomly arranged loose connective tissue.13 The internal orientation of axons allows gliding among and between fascicles, and the epineurium provides longitudinal elongation capability during limb movement.4, 12, 26 Overall, the role of elongation has been considered relatively less important than longitudinal neural excursion in the accommodation of normal peripheral nerve-to-limb movement.2, 29 Longitudinal excursion of a normal ulnar nerve is 10 mm above the elbow and 4.7 to 6 mm below the elbow.2, 29 Adherence of a peripheral nerve to its
surrounding soft tissue bed limits longitudinal excursion requiring elongation to accommodate normal joint motion. 20, *’ Increased length of a peripheral nerve during joint motion leads to a decrease in the neural volume and an increase in intraneural intraneural prespressure. lo, 17, 21’ 29, 3o Increased sure, which has been proposed as the primary process underlying compressive neuropathy, aggravates nerve ischemia and promotes endoneural edema. In chronic conditions disruption of the myelin sheath and permanent endoneural fibrosis may result in impaired neural function.3, 16, ‘*, 23, 27 Our initial interest in subcutaneous transposition of the ulnar nerve with a fasciodermal sling was based on reports by Eaton et al.,* who recommended early mobiliiation in the rehabilitation program. We believed that early neural excursion affected the establishment of an enhanced epineural soft tissue gliding mechanism. Therefore we undertook this investigation to determine whether the qualitative and quantitative outcomes during the early postoperative period were affected. Our outcomes analysis demonstrated that both delayed and immediate mobilization after anterior subcutaneous transposition of the ulnar nerve provided significant relief of primary symptoms. Be tween the two groups there were no significant differences in relief of pain, paresthesias, weakness, or overall level of satisfaction. Both groups had statistically significant improvements in first dorsal interosseous and adductor pollicis muscle strength. When we were designing this retrospective study, we recognized the limitations of evaluating preoperative subjective functional status and symptoms. We now believe that the degree of postoperative improvement of symptoms and subjective functional status is an accurate method of measuring these outcomes. No significant differences were noted between the delayed and immediate mobilization groups with regard to most secondary qualitative and quantitative outcomes. Patients in the immediate mobilization group, however, had a statistically significant earlier return to work or resumption of ADLs (median 1 month) than patients in the delayed mobilization group (median 2.75 months). We conclude that anterior subcutaneous transposition of the ulnar nerve with fasciodermal slings leads to a high degree of patient satisfaction and relief of primary symptoms regardless of when mobilization is initiated. Our present investigation also supports the concept that immediate postoperative active ROM accelerates the rehabilitation
J Shoulder Elbow Volume 7, Number
Weirich
Surg 3
process, which leads to an earlier return to work and resumption of ADLs.
17.
Lundborg G, Rydevik B. Effects of stretching the tibia1 nerve of the rabbit: a preliminary study of the intraneural circulation and the barrier function of the perineurium. J Bone Joint Surg Br 1973;556:390-401
18.
MacKinnon SE, Dellon AL, Hudson AR, Chronic nerve compression. An experimental the rat. Ann Plast Surg 1984; 13: 1 12-20.
19.
McGowan A]. The results of transposition nerve for traumatic ulnar neuritis. J Bone 1950;32B:293-301.
of Fon-
20.
tunnel syndrome. TreatJ Bone Joint Surg Am
Mctellan median J Neurol
21.
Millesi H, Ruth T, Reihsner R, Zoch G. Microsurgical neurolysis: its anatomical and physiological basis and its classification. Microsurgey 1993; 14:430-9.
22.
Millesi H, Zoch G, Ruth T. The gliding apparatus peripheral nerve and its clinical significance. Ann Main Memb Super 1990;9:87-97.
23.
Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve with a non-compressing fasciodermal sling. J BoneJoint Surg Am 1980;62A:820-5.
Ochoa J, Marotte L. The nature of nerve lesion caused by chronic entrapment in the guinea pig. J Neurol Sci 1973; 19:49 l-5.
24.
Goldberg BJ, tight TR, Blair SJ. Ulnar neuropathy at the elbow: results of medial epicondylectomy. J Hand Surg [Am] 1989; 14A: 182-8.
Orf G. What governs the size of the retraction gap in divided peripheral nerves? Neurosurg Rev 198 1;4: 11-6.
25.
Osborne neuritis.
26.
Sunderland S. E & S Livingston;
27.
Sunderland S. Nerve injuries critical appraisal. Edinburgh: 1991. p. 24-36.
28.
Jabaley ME, W a IIace WH, Heckler FR. Internal topography of major nerves of the forearm and hand: a current view. J Hand Surg [Am] 1980;5A: l-l 8.
Thomsen PB. Compression neuritis treated with simple decompression. Stand 1977;48: 164-7.
29.
tang J. Uber das bindegewebe nerven. Zeitschrift Anatomie 1962; 123:6 l-79.
Wilgis EFS, Murphy R. The significance excursion in peripheral nerves. Hand 7616.
30.
Loch G, Reihsner R, Millesi H. Dehnungsrerhalten n. medianus und des n. ulnaris in situ und Hanchir Mikrochir Plast Chir 1989;2 1 :305-9.
2.
Apfelberg DB, Larson S]. Dynamic anatomy ulnar nerve at the elbow. Plast Reconstr Surg 5 1:76-8 1.
3.
Bora FW, Clin Orthop
4.
Clarke tuna.
5.
Craven PR, Green DP. Cubital ment by medial epicondylectomy. 1980;62A:986-9.
Osterman 1982;
AL. Compression 163:20-32.
E, Bearn JG. Brain 1972;95:
6.
Curtis ulnar
7.
Eaton RG. Gelberman reconstruction. 1077-85
BF. Traumatic nerve. J Nerv
The spiral l-20.
nerve
of ortho1979. p. of the 1973;
neuropathy. bands
ulnar neuritis, transplantation Ment Dis 1898;25:480.
Anterior subcutaneous transposition. RH, editor. Operative nerve repair Philadelphia: JB Lippincott; 1991
of In: and p.
10
Haftek J. Stretch effects of stretching Br 1970;.52B:354-65.
11
Heithoff SJ, Millender iH, Nalebuff EA, Petruska AJ. Medial epicondylectomy for the treatment of ulnar nerve compression at the elbow. J Hand Surg [Am] 1990; 15A:22-9.
14
1942;
Lundborg G, Dahlin compression. Hand
American Orthopaedic Association. Manual paedic surgery. Chicago: The Association; 5-27.
13
Obstetrics
16.
his assisand David the statistical
1
12
and
leffert ulnar [Am]
for
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Gynecology
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15. We thank Jeffrey N. Katz, MD, MPH, tance with the preparation of this manuscript A. Schoenfeld, PhD, for his assistance with analysis.
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nerve. Surgery, 751792-3.
et al.
Learmonth
injury of peripheral nerve: acute on rabbit nerve. J Bone Joint Surg
JR. A technique
und die gefasse Entwicklungsgeschichte for
transplanting
the
der
ulnar
RD. Anterior submuscular transposition of the nerve by the Learmonth technique. J Hand Surg 1982;7A: 147-55. LB. Th e pathophysiology Clin 1992;8:2 15-27.
of nerve
Hunter DA. model in of the ulnar Joint Surg Br
Dl, Swash M. Longitudinal sliding of the nerve during movements of the upper limb. Neurosurg Psychiatry 1976;39:566-70.
GV. J Bone
The surgical treatment of tardy Joint Surg Br 1957;39B:782-4. Nerves 1968.
and nerve p. 861-85.
injuries.
of Chir
ulnar London:
and their repair: Churchill Livingstone; of the ulnar nerve Acta Orthop of longitudinal Clin 1986;2: des in vitro.
a
after subcutaneous transposition of the Immediate versus delayed mobilization
Samuel D. Weirich, MD, Richard H. Gelberman, MD, Sharon A. Best, MA, Sven-Olof Abrahamsson, MD, PhD, Deborah C. Furcolo, OTR, and Robert E. tins, MD,
Boston,
Mass., and
St. louis, MO.
We studied 36 patients who had clinical signs and symptoms consistent with cubital tunnel syndrome and in whom nonoperative management failed. These patients underwent anterior subcutaneous transposition of the ulnar nerve followed by either immediate (20 patients) or delayed (I 6 patients) mobilization. All patients were evaluated with an outcomes assessment questionnaire, and 35 of the 36 were given repeat physical examinations. After surgery, there were no significant differences between the two groups in pain relief, weakness, or patient safisfacfion (71% of the immediate mobilization group and 74% of the delayed group) were satisfied. Secondary quantitative outcomes such as grip strength, lateral pinch, or two-point discrimination were also not significantly different between the groups. Both groups had a statistically significant improvement in first dorsal interosseous and adductor pollicis muscle strength. In the immediate mobilization group, however, patients returned to work and resumed activities OF daily living earlier [median I month) than patients in the delayed mobilization group (median 2.75 months). Therefore, we conclude that anterior subcutaneous transposition provides a high degree of satisfaction and relief of symptoms regardless of when mobilization is initiated. However, immediately mobilizing the patient significantly influenced how early the patient returned to work and resumed activities of daily living. (J Shoulder Elbow Surg 7 998;7:244-9.)
Operative
decompression ment of an established elbow that is unresponsive
is the accepted treatulnar neuropathy of the to conservative therapy.
From the Departments of Orthopedic tional Therapy and the General ter-Biostatistics, Massachusetts ton; and the Department Washington University School
Surgery
Clinical
and
Occupo-
Research Cen-
General Hospital, Bosof Orthopedic Surgery, of Medicine, St. Louis.
Reprint requests: Richard H. Gelberman, MD, Professor and Chairman, Department of Orthopedic Surgery, Washington University, School of Medicine, St. Louis, MO63110. Copyright 0 1998 by journal of Shoulder and Elbow Surgery Board of Trustees. 1O.B2746/98/$5.00
244
+ 0
32/l/80678
Most techniques have been devised to relieve areas of compression, to minimize the potential of producing iatrogenic compression, and to promote normal neural gliding by locating the nerve in an unscarred and well-vascularized bed.* To our knowledge, the fasciodermal sling designed by Eaton et al.8 is the only technique that maintains the anterior position of the nerve while allowing early rehabilitation of the patient. Eaton’ suggested use of early mobilization to accelerate the rehabilitation process after surgery. The purpose of our study was to determine whether the timing of postoperative mobilization after transposition of the ulnar nerve influenced functional recovery. The advantages of early mobilization were anticipated to occur in the early period after surgery. We compared clinical results of immediate and delayed mobilization in a series of patients in whom nonoperative management of cubital tunnel syndrome failed. MATERIALS
AND
METHODS
Cubital tunnel syndrome was diagnosed in 36 patients on the basis of pain, numbness, paresthesias, and/or weakness in the ulnar nerve distal to the elbow. Ulnar nerve percussion and elbow flexion tests were used to establish the diagnosis. Electrophysiologic studies of the ulnar nerve were performed in all patients. In 32 patients results of electrophysiologic studies were positive, indicating a delay in conduction across the elbow, demonstrable, symptomatic subluxation of the ulnar nerve, or both. Four other patients who had normal electrophysiologic study results and no evidence of nerve subluxation underwent transposition because of prolonged characteristic symptoms and signs of cubital tunnel syndrome unresponsive to nonoperative treatment. The signs and symptoms included a positive ulnar nerve percussion test at the elbow, persistent diminished light touch sensitivity determined by monofilament testing, and abnormally increased two-point discrimination over the ulnar nerve sensory distribution. One patient
*References
5,
6, 8, 9,
1 1,
14,
15,
19,
25,
28.
J Shoulder Volume 7,
Elbow Number
Weirich
Surg
et al.
245
3
also exhibited mild intrinsic muscle wasting and motor weakness. From 1987 to 1994, conventional nonsurgical treatment failed in 42 patients, who underwent anterior subcutaneous transposition of the ulnar nerve and wore a noncompressing fasciodermal sling. All surgery was performed by Richard H. Gelberman, MD. Two patients were lost to follow-up, and one patient was excluded from the study because of an additional site of ulnar nerve compression. Two other patients
delayed grade
were excluded because they had other neurologic conditions: one patient had sympathetic mediated pain syndrome and the other had amyotrophic lateral sclerosis. Another patient was excluded because of advanced degenerative cervical spine disease and peripheral neuropathy. Hence our study population consisted of 36 patients divided in two groups. Group 1 consisted of 20 patients who had immediate postoperative mobilization after anterior subcutaneous transposition. The 16 patients in
of-motion (ROM) exercises that were initiated on the day of surgery. A 30” extension block splint was used until sutures were removed 8 to 10 days after surgery to decrease the tendency for the nerve to migrate posteriorly. The operated limbs of patients in group 2 were placed in well-padded plaster splints with the elbows flexed 90”. Immobilization of 7 to 30 days (mean 14.4 days) was followed by active and active-assisted ROM exercises. Postoperative evaluation. All patients were called
group 2 underwent mobilization after 7 to 30 days (mean 14.4). The mean age of patients in group 1 was 40.7 years (range 18 to 76 years), and the mean age in group 2 was 50.4 years (range 23 to 74 years). Group 1 had 5 women and 15 men, and group 2 had 5 women and 11 men. The dominant upper extremity was involved in 12 patients in group 1 and 13
for a follow-up evaluation. A standardized outcomes questionnaire was used to evaluate relief of pain, weakness, and paresthesias. Patients were asked when they were able to return to their normal daily activities or work duties without restrictions. Satisfaction with the operative results was rated on a scale of 0 to 10 with 0 representing total dissatisfaction and 10 representing complete satisfaction. This rating was multiplied by 10 to obtain a satisfaction scale percentage. Additional subjective parameters were evaluated. The outcomes questionnaire rated patients’ improvements in their abilities to perform five common activities of daily living (ADLs) and work capability after surgery [Table I). During the follow-up physical examination seven objective parameters were evaluated (Table II).
patients in group 2. One patient in group 1 was ambidextrous. Five (25%) patients in group 1 and 7 (43%) patients in group 2 were involved in workers’ compensation claims. One patient in group 1 moved out of our area and was unable to be examined. However, this patient completed the outcomes questionnaire. Complete follow-up was available for the remaining 35 patients 197% of the study population). months, and mean follow-up 66 months).
Minimum follow-up was 6 was 22 months (range 6 to
Preoperative assessment. A chart review was used to obtain preoperative patient information. Digital sensibility measurement was determined with the static twopoint discrimination and Semmes-Weinstein monofilament tests. Motor strength testing of the ulnar nerveinnervated forearm and hand muscles was performed and graded from 0 to 5 according to the American Orthopaedic Association muscle grading criteria.’ Grip strength was tested with the Jaymar Dynometer, (Asimov Engineering, Los Angeles, Calif.), and lateral key pinch strength was tested with Therapeutic Instruments, (Clifton, N.J.) in both hands. The severity of nerve involvement was graded at the time of operation by the McGowan19 classification systems. In those patients undergoing immediate mobilization (group l), 9 had grade I, 8 grade II, and 3 grade III involvement. In those patients whose mobilization was
(group 21, 6 had grade I, 9 grade II, and 1 III involvement. Operative method. Anterior subcutaneous transposition of the ulnar nerve was performed as originally described by Eaton et al.8 This technique has been modified to mobilize the ulnar nerve proximally for 10 cm to include the arcade of Struthers. The distal intermuscular septum is also resected for this length. Group 1 patients underwent ulnar nerve anterior subcutaneous transposition and immediate active range-
Outcomes analysis. Satisfaction after the operation and relief of pain, weakness, and paresthesias were considered primary outcomes criteria. Secondary outcomes criteria were categorized as qualitative and quantitative. Secondary qualitative outcomes determined the patient’s subjective functional improvement, the rapidity of returning to work, and the ability to perform ADLs. Secondary quantitative outcomes included assessment of electrophysiologic changes, pinch and grip strength, two-point discrimination, SemmesWeinstein quantitative tactile discrimination, and motor
strength
of the ulnar nerve-innervated muscle groups. Outcome variables were analyzed with an analysis of covariance; the baseline variable was used as a covariate. Analysis of Kaplan-Meier survivorship was used to compare return to work and function, and Fisher’s exact test was used for categoric values. A two-sided 0.05 significance level was used throughout. The quantitative variables are reported as mean and standard deviation. Statistics.
246
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J Shoulder
Elbow
May/June
Table
I Common
ADls
and
work
capabilities*
Sleeping Opening jars Picking up small objects (e.g., coins) Carrying a 1 O-pound object (e.g., l-gallon Resuming usual iob activities
Table
milk iug)
*As rated by patients.
RESULTS Study Population In the two study groups there were no significant differences in patient sex, age, hand dominance, involvement in workers’ compensation claims, or severity of ulnar nerve involvement as graded by the McGowan19 classification. Outcomes
Analysis
Primary outcomes. After anterior subcutaneous transposition, immediate mobilization resulted in a patient satisfaction rating of 71% and in delayed mobilization of 74%. This difference was not statistically significant. We were not able to find significant differences in relief of pain, weakness, or paresthesias between the two groups. Secondary outcomes-Qualitative. No statistically significant differences existed between the two groups; there was no significant improvement in their ability to perform five common ADLs and capability to work. Data about resuming ADLs for the two groups were plotted on a Kaplan-Meier curve (Figure 1). The median times to return to work for the immediate movement group was 1 month, and for the delayed movement group was 2.75 months. The log rank test showed a significant increase in return to work time for the patients treated with delayed movement (p = 0.04). Secondary outcomes-Quantitative. Preoperative grip strength values were 53 5 29 and 48 t 38 pounds for immediate mobilization (group 1; n = 16) and delayed mobilization (group 2; n = 151, respectively. After the operation mean grip strength improved to 7.5 i- 35 (n = 19) and 56 ? 35 (n = 16) pounds (Figure 2). No statistically significant improvements in either group or differences between groups were noted after the operation. Although lateral pinch strength measurements improved in both groups after surgery, the difference in values was not statistically significant. Mean lateral pinch strength values before surgery
II Physical
parameters
evaluated
after
Surg
7 998
operation
Two-point discrimination Semmes-Weinstein monofilament testing Grip and key pinch strength Medial epicondyle tenderness Positive elbow flexion test results Ulnar nerve sensitivity in the anteriorly transposed position Motor strength testing of ulnar nerve-innervated muscle groups Adductor pollicis First dorsal interosseous Abductor digiti quinti
were 14 t 9 and 12.5 +- 6.8 pounds in group 1 (n = 15) and 2 (n = 14), respectively, and after surgery were 18 t 7.1 and 14.3 + 6.8 pounds for groups 1 (n = 19) and 2 (n = 15), respectively, (Figure 3). Two-point discrimination was noted to improve within both groups after surgery but was not statistically significant. Mean two-point discrimination was recorded as 6.6 + 2.7 and 7.4 * 3.0 mm before surgery for groups 1 (n = 17) and 2 (n = 14), respectively, and 5.3 t 1.8 and 6.5 2 2.9 mm after surgery for group 1 (n = 19) and group 2 (n = 16), respectively (Figure 4). There was no significant improvement in the preoperative and postoperative Semmes-Weinstein monofilament testing values within either group or between groups (Figure 5). The mean muscle strength values of the first dorsal interosseous muscle before surgery were 4.2 2 1 .O and 3.9 +- 1.5 for groups 1 (n = 17) and 2 (IJ = 13) respectively, compared with postoperative values of 3.9 t 1.5 (n = 19) and 4.8 5 0.3 (n = 15) in groups 1 and 2, respectively. Statistically significant improvement was noted in both the immediate and delayed mobilization groups but was not noted when the two groups were compared. The mean preoperative muscle strength values for the adductor pollicis muscle were 4.5 + 0.9 and 4.6 + 0.7 for Groups 1 (n = 12) and 2 (n = 9), respectively, compared with 4.9 ? 0.3 (n = 19) and 4.9 2 0.3 (n = 15) after the operation. The improvement in muscle strength testing for the adductor pollicis muscle was statistically significant within the immediate mobilization group (p = 0.0102) and within the delayed mobilization group (p = 0.0410). However, no significant
Weirich
I Shoulder Elbow Surg Volume 7, Number 3
et al.
q =z
cl 0
10
247
Immediate
24
6
22 20
=ril
18
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c,
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Months
Figure patients
1 Kaplan-Meier curve of time who did not return to ADls.
versus
percent
Preoperative
of Figure
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for lateral
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strength
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Figure
Postoperative
2 Mean
values
for grip
Postoperative
strength Figure
difference was noted in adductor pollicis muscle strength between the groups. Mean muscle strength testing values for the abductor digiti quinti muscle were 4.3 k 0.9 and 4.2 t 1.6 for the immediate (n = 13) and delayed mobilization (n = 9) groups before the operation, compared with 4.6 k 0.5 (n = 19) and 4.7 -t_0.4 (n = 15) for the two groups after the operation. Statistically significant improvement in abductor digiti quinti muscle strength testing was not encountered in either group or between groups. Both groups had similar postoperative occurrences of medial epicondyle tenderness (48% for group 1 [n = 191 and 50% for group 2 [n = 161) as well as the presence of ulnar nerve sensitivity in the transposed position (53% for group 1 [n = 181 and 53% for group 2 [n = 151). Positive postoperative elbow flexion test results were found in 16% in group 1 (n = 19) and 27% in group 2 (n =
4 Mean
values
for two-point
discrimination
15). Comparison of these values between groups revealed that neither constituted a statistically significant difference. Complications. There were no intraoperative complications in either the immediate or delayed mobilization groups. Five patients’ symptoms were exacerbated in the immediate postoperative period: three in the immediate mobilization group and two in the delayed group. One patient in group 1 continued to have significant symptoms for several months but reported improved symptoms at the last follow-up (7 months after transposition). The remaining four patients noted gradual resolution of symptoms. There were two superficial wound infections, both of which responded to treatment with oral antibiotics. Two patients in whom treatment failed required subsequent ulnar nerve procedures about the el-
248
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et al.
J Shoulder Elbow Surg May/June I998
q n
Preoperative Figure
ment
5 Mean testing.
values
Immediate Delayed
Postoperative for
Semmes-Weinstein
monofila-
bow. Revision surgery consisted of external neurolysis and submuscular transposition in both cases. Four additional patients were dissatisfied with their operative outcomes and would not have had the surgery if given the choice again. Of these six clinical failures, four were treated with delayed mobilization and two were treated with immediate mobilization. The failure rate between the two groups was not statistically significant. Data from the patients in whom treatment failed were included in the statistical analysis. DISCUSSION Longitudinal excursion between the epineurium of the peripheral nerve and its surrounding connective tissue bed has been shown experimentally to play an important role in the accommodation of nerve-to-joint motion.2, 22, 24, 29, 3o The gliding apparatus, which is composed of several layers of tissue surrounding the nerve, consists of alternating vascular and hypovascular layers of randomly arranged loose connective tissue.13 The internal orientation of axons allows gliding among and between fascicles, and the epineurium provides longitudinal elongation capability during limb movement.4, 12, 26 Overall, the role of elongation has been considered relatively less important than longitudinal neural excursion in the accommodation of normal peripheral nerve-to-limb movement.2, 29 Longitudinal excursion of a normal ulnar nerve is 10 mm above the elbow and 4.7 to 6 mm below the elbow.2, 29 Adherence of a peripheral nerve to its
surrounding soft tissue bed limits longitudinal excursion requiring elongation to accommodate normal joint motion. 20, *’ Increased length of a peripheral nerve during joint motion leads to a decrease in the neural volume and an increase in intraneural intraneural prespressure. lo, 17, 21’ 29, 3o Increased sure, which has been proposed as the primary process underlying compressive neuropathy, aggravates nerve ischemia and promotes endoneural edema. In chronic conditions disruption of the myelin sheath and permanent endoneural fibrosis may result in impaired neural function.3, 16, ‘*, 23, 27 Our initial interest in subcutaneous transposition of the ulnar nerve with a fasciodermal sling was based on reports by Eaton et al.,* who recommended early mobiliiation in the rehabilitation program. We believed that early neural excursion affected the establishment of an enhanced epineural soft tissue gliding mechanism. Therefore we undertook this investigation to determine whether the qualitative and quantitative outcomes during the early postoperative period were affected. Our outcomes analysis demonstrated that both delayed and immediate mobilization after anterior subcutaneous transposition of the ulnar nerve provided significant relief of primary symptoms. Be tween the two groups there were no significant differences in relief of pain, paresthesias, weakness, or overall level of satisfaction. Both groups had statistically significant improvements in first dorsal interosseous and adductor pollicis muscle strength. When we were designing this retrospective study, we recognized the limitations of evaluating preoperative subjective functional status and symptoms. We now believe that the degree of postoperative improvement of symptoms and subjective functional status is an accurate method of measuring these outcomes. No significant differences were noted between the delayed and immediate mobilization groups with regard to most secondary qualitative and quantitative outcomes. Patients in the immediate mobilization group, however, had a statistically significant earlier return to work or resumption of ADLs (median 1 month) than patients in the delayed mobilization group (median 2.75 months). We conclude that anterior subcutaneous transposition of the ulnar nerve with fasciodermal slings leads to a high degree of patient satisfaction and relief of primary symptoms regardless of when mobilization is initiated. Our present investigation also supports the concept that immediate postoperative active ROM accelerates the rehabilitation
J Shoulder Elbow Volume 7, Number
Weirich
Surg 3
process, which leads to an earlier return to work and resumption of ADLs.
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Lundborg G, Rydevik B. Effects of stretching the tibia1 nerve of the rabbit: a preliminary study of the intraneural circulation and the barrier function of the perineurium. J Bone Joint Surg Br 1973;556:390-401
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Millesi H, Zoch G, Ruth T. The gliding apparatus peripheral nerve and its clinical significance. Ann Main Memb Super 1990;9:87-97.
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Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve with a non-compressing fasciodermal sling. J BoneJoint Surg Am 1980;62A:820-5.
Ochoa J, Marotte L. The nature of nerve lesion caused by chronic entrapment in the guinea pig. J Neurol Sci 1973; 19:49 l-5.
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Goldberg BJ, tight TR, Blair SJ. Ulnar neuropathy at the elbow: results of medial epicondylectomy. J Hand Surg [Am] 1989; 14A: 182-8.
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Thomsen PB. Compression neuritis treated with simple decompression. Stand 1977;48: 164-7.
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