Anatomical study of the inferior extensor retinaculum and the oblique superolateral band: implications for the Brostrom-Gould procedure

PURPOSE: The Brostrom-Gould procedure is currently the gold standard surgical choice for the treatment of chronic ankle instability; it can significantly improve ankle function and stability in patients. However, recent studies have reported doubts regarding the feasibility of the inferior extensor retinaculum (IER) after Brostrom-Gould and therapeutic effects compared with the Brostrom procedure. The purpose of the present study was to observe the anatomical characteristics of the lateral part of the IER using cadaveric bodies in order to guide the surgical operation of chronic ankle instability. METHODS: Twenty-three cadaveric ankles were dissected. The morphology of the IER and its internal structure was observed and recorded for each ankle. The shortest distance between the Stem ligament of the IER and the anterior fibular periosteum (AFP) was measured and recorded, then attempts were made to suture the Stem to the AFP. RESULTS: Twelve of the cadaveric ankles were observed as having an oblique superolateral band (OSLB) that had a tough texture upward of the lateral IER connecting with SL, as are the characteristics of the oblique superolateral band (OSLB) reported in previous studies. The inner and outer membrane of the OSLB were connected with inner and outer membrane of Stem. The average value of the distance between the Stem and AFP was 11.60 ± 2.71 mm, and the maximum and the minimum distance were 19.04 mm and 6.53 mm, respectively. The P -value (P = 0.2) resulting from a single sample K-S test confirmed that the distribution of distances conformed to normality. None of the SL in the study could be sutured to the AFP. CONCLUSION: The OSLB of the IER has a tough texture and connects with the Stem, and has the potential be utilised in the Brostrom-Gould procedure. However, we do not recommend utilization of the Stem in this operation regardless of the distance between the AFP and the Stem. When the Stem cannot be used to enhance repair in this operation, other solutions can be used for strengthening and to protect the repaired ATFL.