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】　 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

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

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 hands Dominant / Non 16 / 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 3 / 7 hands Mean age: 74.6 y.o. Mean duration: 4.4 yrs Thumb complaint (+)/(-) 7 / 2 hands

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

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 to higher 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 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

Discussions

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

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 　　　　　　　　　

・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

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