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.

Background

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 】　

Yuki Hara et al, 　　 51st JSSH meeting, 2008

Patient’s complaint or request 46.8 %

Severeatrophy 18.1%

Not perform primary opponensplasty 26.1%

Needle EMG 9.0%

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

Purpose of this study

Methods

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

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

　

・

Results

MUP(+) group 35 patients 39 hands♂ 16 hands ♀ 23 handsDominant / Non 16 / 23 handsMean age: 64.1 y.o.Mean duration: 5.1 yrsThumb complaint (+)/(-) 27 / 12 hands

MUP(-) group 9 patients 10 hands♂ 5 hands ♀ 4 handsDominant / Non 3 / 7 handsMean age: 74.6 y.o.Mean duration: 4.4 yrsThumb complaint (+)/(-) 7 / 2 hands

APB muscle strength at one year after surgery

　 MUP(+) group

Recovery rate tohigher than MMT 【 3 】　　　　　＝ 100 ％　　　　　　

0-1

MMT grade

(n)

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.

APB muscle strength at one year after surgery

MUP(-) group 　　

Recovery rate tohigher than MMT 【 3 】　　　　　＝ 44 ％　　　　　　

(n)

0-1

MMT grade

What were poor prognostic factors of pre-op MUP(-) group?

Patient’s details

Age Sex Side Duration Comorbidity MMT SCV71 ♂ Lt 6m 　 3 24.149 ♂ Lt 3y 　 4 36.155 ♀ Rt 4y 　 4 26.174 ♂ Lt 8m Diabetes 3 24.675 ♀ Rt 6y 　 4 35.2

54 ♀ Rt 2yC.

Myelopathy

0-1 24.9

54 ♀ Lt 2yC.

Myelopathy

0-1 25.3

79 ♂ Lt 6y 　 0-1 8.267 ♂ Lt 7y 　 0-1 －93 ♀ Rt 10y 　 2 －

Discussions

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 opponensplastyRequired in some cases

Which patients? 　→　 Next task

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 　　　　　　　　　

・ 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 accordingto patient’s demands and results of EMG studies

　　　　　　　　　

Conclusion

Needle EMG is very useful for deciding

the necessity of opponensplasty

in carpal tunnel syndrome