Comparison of Arthroscopic Approaches and Accessible Anatomic Structures During Arthroscopy of the Caudal Pouches of Equine Femorotibial Joints

Abstract

To (1) describe a caudal approach to equine medial and lateral femorotibial (FT) joints and (2) illustrate the complex anatomic detail of the caudal compartments of the lateral FT joint. Prospective experimental study. Cadaveric equine hindlimbs (n = 36; 26 horses) and 6 horses (11 hind limbs). Stifles (n = 8) were dissected and 10 FT joints were injected with silicone. Arthroscopic exploration (n = 29) was performed, followed by dissection to determine sites and structures penetrated during entry. A more caudal approach to the caudal pouch of the medial FT improved anatomic observation. A more caudal approach to the caudal pouch of the lateral FT joint occasionally caused damage to the common peroneal nerve; however, after reverting to the previously described approach, damage was avoided. Arthroscopy of the caudal pouch of the medial FT joint was facilitated using a more caudomedial approach, which improved observation of intrasynovial structures, most importantly, the caudal cruciate ligament and caudal horn of the medial meniscus. A more caudal approach to the caudal pouch of the lateral FT joint cannot be safely performed without risk to the common peroneal nerve and therefore the standard caudal approach is described in detail. A caudomedial arthroscopic approach allows improved surgical assessment of meniscal or caudal cruciate ligament injury. Care should be exercised when exploring the caudal pouch of the lateral FT joint because the common peroneal nerve is variably located and could easily be damaged during arthroscope or instrument insertion, especially if the limb is minimally flexed.