The effect of axial and abaxial release on meniscal displacement in the dog

Abstract

The meniscal release (MR) is used to minimize meniscal pathology after Tibial Plateau Leveling Osteotomy (TPLO) surgery. The purposes of this study were: (i) to describe meniscal orientation in a unaltered cadaveric canine stifle, a cruciate deficient stifle, TPLO repaired stifle with and without the MR using magnetic resonance imaging; (ii) to determine if the abaxial release is equivalent to the axial release in its ability to affect caudal pole displacement in a TPLO repaired stifle and (iii) to evaluate with MRI the effect of MR on the femorotibiol articular cartilage contact area in a TPLO repaired stifle. Briefly, cadaver limbs were placed into a jig designed to mimic a weight-bearing stance at 140 degrees and 90 degrees at the stifle. The limbs were sequentially evaluated from the unaltered state; after cranial cruciate ligament transection; after TPLO stabilization; and finally after a meniscal release. No significant difference was found between the intrameniscal area (IMA) of the abaxial and axial meniscal releases although there was an increase in the IMA after the meniscal release compared to the IMA in the normal, cranial cruciate ligament deficient stifle, and TPLO stabilized stifle. In the abaxial release, a meniscal remnant remained in situ and provided a space effect between the femur and the tibial plateau. This is in contrast to the axial meniscal release, where the entire caudal pole of the medial meniscus relocated caudolaterally and consequently permitted more direct femorotibial contact. Overall, however, there was evidence of caudal pole compression of the medial meniscus throughout the MRI series which was ameliorated by either of the MR procedures.

Systematic review of the prevalence, risk factors, diagnosis and management of meniscal injury in dogs: Part 2

“…Four biomechanical studies elucidated the biomechanical alterations of MR in the canine stifle (Kennedy et al . , Pozzi et al . , , ).…”

Effect of 9 mm Tibial Tuberosity Advancement on Cranial Tibial Translation in the Canine Cranial Cruciate Ligament‐Deficient Stifle

“…An alternate method of testing could utilize the entire hind limb with the foot and calcaneal mechanism intact, which may portray in vivo anatomy better, but also, may introduce more uncontrolled variables. 88,89,153 The TTA theory suggests that the forces beyond the quadriceps can be fully accounted for by using the total force acting around the stifle, and this is how testing was done in this experimental model. None of the cadavers used in this study had any evidence of stifle pathology on radiographs or on gross examination.…”

“…140 The menisci provide for joint stability by limiting varus/valgus motion and by increasing the articular surface area for contact with the femoral condyles. 88 The collateral ligaments provide additional control, though in an in vitro study, the joint capsule was found to not provide any cranial to caudal stability by itself. 141 However, in another study the joint capsule significantly reduced cranial to caudal translation.…”

“…When the medial meniscus was assessed by magnetic resonance imaging before and after a meniscal releasing procedure, the caudal horn did move caudally with simulated weight bearing. 88 The authors suggested that meniscal release eliminated the function of the medial meniscus, potentially subjected the femoral and tibial articular surfaces to increased stress, but did allow for reduced chance of postoperative medial meniscal damage. 88 In a radiographic study with simulated weight bearing forces, the effect of meniscal release was not different than caudal pole medial meniscectomy in relation to tibial translation in CCL deficient cadaver specimens.…”

“…88 The authors suggested that meniscal release eliminated the function of the medial meniscus, potentially subjected the femoral and tibial articular surfaces to increased stress, but did allow for reduced chance of postoperative medial meniscal damage. 88 In a radiographic study with simulated weight bearing forces, the effect of meniscal release was not different than caudal pole medial meniscectomy in relation to tibial translation in CCL deficient cadaver specimens. 89 Following TPLO, the caudal medial meniscus was unloaded, and thus the effect of meniscal release was reduced.…”