Endoscopic treatment for posterior ankle impingement: high patient satisfaction and low recurrence rate at long-term follow-up

Posterior Ankle Impingement: It's Not Only About the Os Trigonum

Background

Os trigonum and Stieda process are common etiologies for posterior ankle impingement syndrome (PAIS), and diagnosis is typically made by radiographs, computed tomographic, or magnetic resonance imaging. However, these static tests may not detect associated soft tissue and bony pathologies. Posterior ankle and hindfoot arthroscopy (PAHA) is dynamic, providing at least ×8 magnification with full anatomical visualization. The primary aim of this study was to report the prevalence of associated conditions seen with trigonal impingement treated with PAHA.

Methods

In this retrospective comparative study, patients who underwent PAHA for PAIS due to trigonal impingement, from January 2011 to September 2016, were reviewed. Concomitant open posterior procedures and other indications for PAHA were excluded. Demographic data were collected with pre- and postoperative diagnosis, arthroscopic findings, type of impingement, location, associated procedures, and anatomical etiologies. Trigonal impingements were divided in os trigonal or Stieda and subgrouped as isolated, with flexor hallucis longus (FHL) disorders, with FHL plus other impingement, and with other impingement lesions.

Results

A total of 111 ankles were studied-74 os trigonum and 37 Stieda. Isolated trigonal disorders accounted for 15.3% of PAIS (n = 17). Cases having associated conditions had a mode of 3 additional pathologies. FHL disorders were found in 69.4%, subtalar impingement in 32.4%, posteromedial ankle synovitis in 25.2%, posterolateral ankle synovitis in 22.5%, and posterior inferior tibiofibular ligament impingement in 19.8% of cases. Associated pathologies were observed in 58.6% of cases when FHL was not considered. Significant differences were noted comparing os and Stieda (isolated: 20.3% to 5.4%, P = .040; FHL plus others: 35.1% to 59.5%, P = .015).

Conclusion

Trigonal bone (os trigonum or Stieda) was found to cause impingement in isolation in a small proportion of cases even when the FHL was considered part of the same disease spectrum. This should alert surgeons when considering removing trigonal impingement. Open approaches may limit the visualization and assessment of associated posterior ankle and subtalar pathoanatomy, thus possibly overlooking concomitant causes of PAIS.

Level of Evidence

Level III, retrospective comparative study.

Open Versus Endoscopic Surgical Treatment of Posterior Ankle Impingement: A Meta-analysis

BACKGROUND

Surgical treatment of symptomatic posterior ankle impingement consists of resection of the bony impediment and/or debridement of soft tissue. Historically, open techniques were used to perform surgery with good results. However, since the introduction of endoscopic techniques, advantages attributed to these techniques are shorter recovery time, fewer complications, and less pain.

PURPOSE

The primary purpose was to determine whether endoscopic surgery for posterior ankle impingement was superior to open surgery in terms of functional outcome (American Orthopaedic Foot & Ankle Society [AOFAS] score). The secondary aim was to determine differences in return to full activity, patient satisfaction, and complications.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE (Classic), and CINAHL databases were searched. Publication characteristics, patient characteristics, surgical techniques, AOFAS scores, time to return to full activity, patient satisfaction, and complication rates were extracted. The AOFAS score was the primary outcome measure. Data were synthesized, and continuous outcome measures (postoperative AOFAS score and time to return to full activity) were pooled using a random-effects inverse variance method. Random-effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients who were satisfied and who experienced complications.

RESULTS

A total of 32 studies were included in this review. No statistically significant difference was found in postoperative AOFAS scores between open surgery (88.0; 95% CI, 82.1-94.4) and endoscopic surgery (94.4; 95% CI, 93.1-95.7). There was no difference in the proportion of patients who rated their satisfaction as good or excellent, 0.91 (95% CI, 0.86-0.96) versus 0.86 (95% CI, 0.79-0.94), respectively. No significant difference in time to return to activity was found, 10.8 weeks (95% CI, 7.4-15.9 weeks) versus 8.9 weeks (95% CI, 7.6-10.4 weeks), respectively. Pooled proportions of patients with postoperative complications were 0.15 (95% CI, 0.11-0.19) for open surgery versus 0.08 (95% CI, 0.05-0.14) for endoscopic surgery. Without the poor-quality studies, this difference was statistically significant for both total and minor complications, 0.24 (95% CI, 0.14-0.35) versus 0.02 (95% CI, 0.00-0.06) and 0.14 (95% CI, 0.09-0.20) versus 0.03 (95% CI, 0.01-0.05), respectively.

CONCLUSION

We found no statistically significant difference in postoperative AOFAS scores, patient satisfaction, and return to preinjury level of activity between open and endoscopic techniques. The proportion of patients who experienced a minor complication was significantly lower with endoscopic treatment when studies of poor methodological quality were excluded.

Outcomes of a 2-Portal Endoscopic Technique for Osseous Lesions Resulting in Posterior Ankle Impingement Syndrome

Posterior ankle impingement syndrome is common in sporting populations and encompasses a range of disorders that cause posterior ankle pain during maximal forced plantarflexion. The aim of this study was to evaluate the short- and medium- to long-term outcomes of 2-portal endoscopic surgery for osseous lesions causing posterior ankle impingement syndrome. This was a retrospective case series analysis of all patients who underwent 2-portal endoscopic surgery at a single institution between 2005 and 2016. Visual analogue scales and selected components of the Short Form of the Revised Foot Function Index were used to assess ankle function, with the median follow-up time being 4.8 years. Of the 52 patients, 49 (94%) were able to return to their previous sport/physical activity, with the mean time taken being 5.8 months. At the completion of follow-up, the mean pain score during exercise had improved from 7.5 to 0.9 points. The mean work and sporting function scores also improved, from 5.9 to 9.6 points and 2.9 to 8.8 points, respectively. The mean score of the Short Form of the Revised Foot Function Index also improved by 77.7 points, from 84.4 to 6.7 at the completion of follow-up. There were no postoperative infections or any other major complications. This study provides strong supporting evidence for the use of hindfoot endoscopy in the treatment of posterior ankle impingement syndrome in athletes.