Abstract
Research Type:
Level 4 – Case series
Introduction/Purpose:
Total ankle arthroplasty (TAA) through an anterior approach is a widely performed procedure. The success of this procedure can be substantially compromised by wound healing complications. The multiple extensor tendons on the anterior aspect of the ankle are covered by the extensor retinaculum and the crural fascia, creating an effective restraint and preventing tendon bowstringing. Repairing this layer following an anterior approach to the ankle reduces tension on the skin and may prevent wound healing complications. Details regarding the shape and thickness of the extensor retinaculum and crural fascia remain underexplored. The purpose of this cadaveric investigation is to identify the zones of maximal tissue thickness. This knowledge may optimize the surgeons’ ability to repair this important layer.
Methods:
The study used ten cadaver lower limb specimens from the Dalhousie Body Donation Program. The study was approved by the Local Ethics Board. An anterior incision of 15cm was made to reveal the area of interest, followed by the gross analysis of the shape of the IER. Histological samples were extracted using a 4mm punch biopsy, with 12 samples per specimen in four rows spaced 3 cm apart. Each row contained samples over the extensor hallucis longus (EHL), extensor digitorum longus (EDL), tibialis anterior (TA), for a total of 120 specimens. Samples were fixed in 10% formalin, sectioned, and mounted on slides for analysis. ImageJ was used to assess the thickness in um. SPSS was used to analyze the data by averaging five measurements per sample, then averaging these values across all ten specimens for each zone and calculating the standard deviation. An ANOVA was performed to compare the averages.
Results:
Of the ten specimens, only one had the X-shaped IER, the rest were Y-shaped. The thickest portions of the extensor retinaculum were at the level of the ankle joint (zone 8: 641.47±322.00 and 9: 632.67 ±350.65) and 3 cm from the ankle joint (zone 4: 621.49 ± 306.90). On average, qualitatively, the extensor retinaculum tissue overlying the TA and EHL was the thickest. However, One-way ANOVAs showed no significant differences in thickness between horizontally grouped (F = 1.121, p = .353), vertically grouped (F = .348, p = .709), or individual zones (F = .669, p = .765).
Conclusion:
Quantitatively, the result of the study showed no variability, as there was no consistent thickness variation across zones when using one-way ANOVA comparing horizontal and vertical grouping as well as individual zones. However, qualitatively, zones 4, 8, and 9 appeared thicker. In conclusion, there is no one region where surgical reinforcement may improve surgical wound healing.
