1. Appropriate Indications of Opponensplasty in Carpal Tunnel Syndrome
Yuki Hara, Yasumasa Nishiura, Yoshiko Nakajima, Naoyuki Ochiai
Depertment of Orthopaedic Surgery
University of Tsukuba, JAPAN
The authors have no financial conflicts of interest to disclose concerning the presentation.

2. Background

3. Questionnaire about the treatment of idiopathic
carpal tunnel syndrome (2008)
Subjects：471 of the JSSH members
【Reasons for performing a tendon transfer
in cases of thumb opposition dysfunction】　
Not perform
primary
opponensplasty
26.1%
Needle
EMG
9.0%
Patient’s complaint
or request
46.8 %
Severe
atrophy
18.1%
Yuki Hara et al,　　51st JSSH meeting, 2008

4. Purpose of this study
Investigation of natural course of muscle strength of
severe atrophic APB after carpal tunnel release only
To clarify appropriate indications for opponensplasty
in idiopathic carpal tunnel syndrome

5. Methods

6. Our methods
Diagnosis of CTS　
Clinical examination
Electrophysiological examination
Motor distal latency and MCV of forearm
SCV of finger to wrist and forearm
APB-CMAP(-) ⇒Needle EMG
Surgery：Open carpal tunnel release

7. Study periods: April 2001～March 2012 Subject：44 patients 49 hands
Pre-op MMT of APB was 【1】　or 【0】
Diagnosed by needle EMG
Underwent carpal tunnel release only
Evaluations
　　・Age at surgery, gender, dominant or nondominant
・Symptomatic duration
・Complaint about thumb dysfunction
・APB muscle strength at one year after surgery ・

8. Results

9. MUP(+) group
35 patients 39 hands
♂ 16 hands ♀ 23 hands
Dominant / Non / 23 hands
Mean age: 64.1 y.o.
Mean duration: 5.1 yrs
Thumb complaint (+)/(-) 27 / 12 hands
MUP(-) group
9 patients 10 hands
♂ 5 hands ♀ 4 hands
Dominant / Non / 7 hands
Mean age: 74.6 y.o.
Mean duration: 4.4 yrs
Thumb complaint (+)/(-) 7 / 2 hands

10. APB muscle strength at one year after surgery
　 MUP(+) group
Recovery rate to
higher than MMT【3】
　　　　　＝100％
(n)
0-1
MMT grade

11. If a voluntary contraction of the APB muscle is
observed pre-operation,
the patients will be able to acquire useful
thumb function within a year after carpal
tunnel release.

12. APB muscle strength at one year after surgery
MUP(-) group　
Recovery rate to
higher than MMT【3】
　　　　　＝44％
(n)
0-1
MMT grade

13. What were poor prognostic factors of pre-op MUP(-) group?
Patient’s details
Age
Sex
Side
Duration
Comorbidity
MMT
SCV 71 ♂ Lt 6m 3
24.1 49 3y 4
36.1 55 ♀ Rt 4y
26.1 74 8m
Diabetes
24.6 75 6y
35.2 54 2y
C. Myelopathy
0-1
24.9
25.3 79
8.2 67 7y － 93
10y 2

14. Discussions

15. Which patients? → Next task
Result of needle EMG study of APB muscle predicted..
Motor unit potential (+) →　All patients
(-) →　One half of patients
will acquire useful thumb function
within a year after CTR
Primary opponensplasty
Not required
Primary opponensplasty
Required in some cases
Which patients?　→　Next task

16. Surgeons should show all choices and their likely clinical outcome
Needle EMG study for severe CTS patients
Drawbacks Benefit
Pain Predictable surgery
Invasive outcome
but its invasion and risk are less than opponensplasty!
Surgeons should show all choices
and their likely clinical outcome
to patients 　　　　　　　　　

17. ・Primary opponensplasty produces good clinical results
and patients satisfaction
(Terrono AL:1993, Wan SH: 2007, Park IJ: 2010,
Uemura T: 2010, Kang SW: 2012, Naeem R:2013)
・Opponensplasty permits patients functional recovery
immediately
・Some patients had no complaint about thumb
dysfunction even if their APB were severe atrophy
Primary opponensplasty should be performed according
to patient’s demands and results of EMG studies

18. Conclusion Needle EMG is very useful for deciding
the necessity of opponensplasty
in carpal tunnel syndrome