Does Immediate Post-Operative Use of Neuromuscular Electrical Stimulation (NMES) Influence Calf Atrophy Following Achilles Tendon Surgery? A Prospective RCT

Christopher F. Hyer, DPM, MS, Gregory Berlet, MD, Jim Wilgus, DPT, Christy Collins, PhD, Joshua Houser, MD, Matt Crill, MPT, MS, Carrie Sexton, Emily Stansbury, Patrick Bull, DO, Terrence Philbin, DO

Does Immediate Post-Operative Use of Neuromuscular Electrical Stimulation (NMES) Influence Calf Atrophy Following

Achilles Tendon Surgery? A Prospective RCT

Christopher F. Hyer, DPM, MS

Our disclosures are in the Final AOFAS Mobile App.There is a potential conflict with this presentation due

to: Research grant, DJO Global (CFH,GCB,TMP)

Statement of Purpose

• Post-surgical muscle atrophy common after Achilles surgery and immobilization

• Lengthy recovery time and sometimes never fully recover

• NMES shown to accelerate recovery in orthopedic surgery

Statement of Purpose

• Perhaps minimizing calf atrophy critical to positive patient outcomes

• The purpose of the study was to quantify the atrophy sparing effects of NMES applied immediately after surgery and its effect on post-operative patient recovery

Study Methods• IRB approved, double

blind, RCT, 40 patients– Powered at 80%

• 20 active and 20 ‘sham’ 4 lead NMES devices

• Blinded study team: MSK radiologist, Physical therapy, surgeons

• Biostatistician

Table 1: Pre and Post Operative Measures

Measure Pre-op Post-op weeks 2, 6, 12

Calf size ✔ ✔

FOTO score

✔ ✔

AOFAS hindfoot

✔ ✔

MRI leg ✔ Weeks 2and 6 only

Study Methods• Only Achilles procedures including:

– Acute rupture repair– Insertional detachment/re-attachment repair– Chronic repair with FHL transfer

• Standard Post-op Regimen:– 4-lead NMES applied in OR under Jones splint, NWB 2 weeks

(± 1 week) with NMES– PWB Boot with NMES x 4 weeks– Discontinued NMES at 6 weeks– PTx at 6 weeks

Results• 40 subjects:

• Mean age: 48.9• Mean BMI: 32.2

• Active group: trended toward higher FOTO and AOFAS but not SS

• Volumetric MRI trended less atrophy in active, but not SS

• No difference in calf circumference at any interval

• 6.4% incidence of device used on wrong setting (8% active, 5% sham) this was SS

Conclusions• In prior case series, NMES anecdotally

decreased pain/swelling, minimized calf atrophy and improved patient outcomes

• In the double blind RCT, trends to improved outcomes in active group but not SS

Conclusions/Questions• Is 6 weeks of NMES treatment and 12

weeks of follow-up long enough to quantify and measure post-op atrophy? – Trends there but perhaps needed longer

follow-up

• ‘Sham’ device still provided minimal stimulation to seem ‘real’. Did this still have minor effect which minimized the delta between Active and Sham?

References

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4. Takano Y, Haneda Y, Maeda T, Sakai Y, Matsuse H, Kawaguchi T, Tagawa Y, ShibaN. Increasing muscle strength and mass of thigh in elderly people with the hybrid-training method of electrical stimulation and volitional contraction. Tohoku J. Exp. Med. 2010; 221: 77-85.