Anatomical bases of endoscopic tarsal tunnel release: anatomical and ultra-sonographic study with a preliminary clinical report

Surg Radiol Anat. 2011 Dec;33(10):929-36. doi: 10.1007/s00276-011-0890-y. Epub 2011 Oct 29.


Purpose: The purpose of our study is to present the anatomical bases of a new technique for endoscopic tarsal release and to report the preliminary clinical outcome for this technique.

Method: Anatomical study The technique was performed on 12 intact adult lower limb specimens. The location of portals was evaluated as well as the integrity of the neurovascular bundle. Ultra-sonographic study A prospective case control study was done on 10 patients (11 feet) and 14 normal volunteers (28 feet). Three parameters were measured; the thickness of flexor retinaculum, the nerve cross-section area and the depth of tarsal tunnel. Clinical study Seven patients with idiopathic proximal Tarsal Tunnel Syndrome (TTS) were treated by endoscopic TTR using a modified trocar cannula and dilator system. Preoperative and postoperative evaluation was done by electrophysiological studies and ultra-sonography. Evaluation was done using Takakura's rating scale.

Results: Anatomical study The proximal and distal portals were located at 13 mm (±1.59 STD) and 17.91 mm (±1.44 STD) from the proximal and distal borders of FR, respectively. There was intact neurovascular bundle in all specimens. Ultra-sonographic study There was statistically significant difference in the mean nerve cross-sectional area and the thickness of the FR between the control group and the patients group (P < 0.05). Clinical study The mean TRS improved from 2.28 ± 1.11 STD preoperatively to 8.43 ± 0.97 at 2 years follow-up. The overall good to excellent results was 85.7%.

Conclusion: Based on this preliminary clinical study, endoscopic tarsal tunnel release by the technique described could obtain excellent to good results in 85.7% of patients with idiopathic proximal tarsal tunnel. The anatomical study proved the safety of the technique on the neurovascular structures. Ultra-sonography was an effective tool for preoperative diagnosis and postoperative follow-up.

Level of evidence: Case series study, Level IV.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Ankle / anatomy & histology
  • Ankle / diagnostic imaging
  • Ankle / surgery*
  • Case-Control Studies
  • Endoscopy / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Tarsal Tunnel Syndrome / diagnostic imaging
  • Tarsal Tunnel Syndrome / surgery*
  • Treatment Outcome
  • Ultrasonography