Arthroscopic Quantitative Measurement of Medial Clear Space for Deltoid Injury of the Ankle: A Cadaveric Comparative Study With Stress Radiography

SLR - June 2022 - Thomas George Jr, DPM

Reference: Chiang, C.-C., Lin, C.-F. J., Tzeng, Y.-H., Teng, M.-H., & Yang, T.-C. (2022). Arthroscopic quantitative measurement of medial clear space for deltoid injury of the ankle: A cadaveric comparative study with stress radiography. The American Journal of Sports Medicine, 50(3), 778–787. 

Level of Evidence: Level III

Scientific Literature Review

Reviewed By: Thomas George Jr, DPM
Residency Program: John Peter Smith Hospital – Fort Worth, TX

Podiatric Relevance: Ankle arthroscopy has been increasingly utilized as both a diagnostic tool as well as direct treatment for ankle pain secondary to arthritis, OCDs, and several other rationales. Evaluating deltoid sufficiency is often difficult as we rely mainly on MRI imaging which can take some time in the setting of a trauma. The use of arthroscopy intraoperatively is a more reliable way to assess the degree of deformity to this integral structure within the ankle joint. 
Twenty-four (24) lower extremity cadavers were used and divided into 4 groups based on deltoid ligament disruption–intact deltoid ligament, superficial deltoid ligament disruption, deep deltoid ligament disruption, and complete deltoid ligament disruption. All 24 cadavers were used to measure medial clear space using ankle arthroscopy, ERS radiography, and GS radiography at varying sections of the syndesmotic ligaments.
Results: Patients with noninjured deltoid versus injured deltoid had MCS that decreased respectively at 0.939 for arthroscopy, 0.932 for ERS radiography, and 0.874 for GS radiography. When considering arthroscopy versus GS radiography, the difference was significant with P value 0.014. When considering deltoid injury as complete vs incomplete, MCS again progressively decreased at 0.811 for arthroscopy, 0.656 for ERS radiography, and 0.721 for GS radiography; arthroscopy and ERS radiography had a difference that was significant in nature as did arthroscopy and GS radiography. 
Conclusions: The use of arthroscopy for diagnosis of deltoid ligament rupture and tare is a beneficial addition to the foot ankle surgeons evaluation of ankle injuries. Often MRI does not allow the surgeon to truly evaluate deep vs superficial injury either which arthroscopy readily can. Though the use of arthroscopy may add time to the surgical management of an injury, the additional information it provides can truly make a difference in treatment choice and, as we have seen in other studies, provide a more robust, stable augmented repair to the ankle joint complex.