SLR - August 2014 - Keveh Panahi

The Role of Arthroscopy in the Treatment of Functional Instability of the Ankle

Reference:  Kerr HL, Bayley E, Jackson R, Kothari P. The Role of Arthroscopy in the Treatment of Functional Instability of the Ankle.   Foot Ankle Surg. 2013 Dec; 19(4): 273-5.

Scientific Literature Review

Reviewed By: Kaveh Panahi, DPM
Residency Program: Hoboken University Medical Center, Hoboken, NJ

Podiatric Relevance: Ankle sprains are the most common injuries in podiatric and orthopedic practice making up 75-85 percent of all ankle injuries. These injuries may result in two separate categories of ankle instabilities with the majority being mechanical, which are diagnosed with use of radiographic and imaging studies with talar tilt of >9 degrees. A smaller portion of these symptomatic ankle instabilities, which the authors identify by functional instability,  are defined with less specific diagnoses such as pain and giving way of ankle without any evidence of mechanical sources. The focus of this study is on treatment of functional instability after exhaustion of all conservative treatments.
Methods: This study was a retrospective analysis of 77 patients with a mean age of 38.1 years who presented with ankle instability after one episode of ankle sprain from 2005 to 2007. All patients were first treated by conservative means such as physiotherapy and occasional use of steroid injections. All patients who failed conservative treatments underwent radiographic and imaging studies to identify the category of their ankle instability. Patients with mechanical instabilities were excluded from this study. However those with functional instability received ankle arthroscopy with a primary focus on intra-articular scars that were treated by debridement. The post operative course included a formal functional rehabilitation with physiotherapy, post-operative visits for 6 weeks, and minimum follow up of six months.

Results: Out of 77 patients, five cases were excluded secondary to diagnosis of true mechanical instability. Thirty patients with clinical stability of the ankle had an MRI and 17 had a ligamentous abnormality. Twenty-one patients were given steroid injections with temporary relief to only 11. However, all of the 72 patients diagnosed with functional instability underwent ankle arthroscopy. Arthroscopy of the ankles revealed significant amount of scar tissue in 67 patients (93.1 percent) focused mainly on the antero-lateral aspect of the ankle and peri-syndesmosis (58.3 percent). Six patients had scar tissues present in the antero-medial and medial gutter. Thirteen patients had scars tissue throughout the ankle and 10 patients with scars only in the lateral gutter. Fifty-two patients (72.2 percent) had symptomatic improvement post arthroscopy. Twenty patients (27.8 percent) did not improve. Of the 20 patients, nine were referred to pain clinic and the other 11 did not seek any further treatments. Two patients had post operative complication comprising of wound dehiscence. Seventeen patients were diagnosed with osteochondral lesions that were not picked up by original MRI studies. Of these 17, 5 had isolated OCD and 12 had concurrent OCD with scars. Eight patients were treated with abrasive chondroplasty (87.5 percent improvement) and the rest treated only with debridement of scar tissues (77.8 percent improvement). All five patients with isolated OCD who were treated with chondroplasty improved symptomatically.

Conclusion: This study demonstrated that the majority of the patients who presented with post sprain ankle instability also had considerable amount of intra-articular scarring with occasional OCD lesions. Treatment of these patients with arthroscopic debridement of the scar tissues and OCD lesions after exhaustion of the conservative treatments resulted in significant improvement. The authors concluded that ankle arthroscopy and associated treatments may be considered in cases with vague symptoms that results from ankle sprains with no clinical or imaging evidence of mechanical origins. 

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