Comparative histomorphometric analysis of cellular phenotype in canine stifle ligaments and tendon

Abstract

Objective: To measure the density of cellular phenotypes in canine caudal cruciate ligament (CaCL), cranial cruciate ligament (CrCL), medial collateral ligament (MCL), and long digital extensor tendon (LDET). Study design: Ex-vivo study. Methods: Ten CaCL, CrCL, MCL, and LDET obtained from 1 stifle of 10 dogs with no gross pathology were analyzed histologically. The density of cells with 3 nuclear phenotypes (fusiform, ovoid, and spheroid) was determined within the core region of each specimen. Results: Cells with fusiform nuclei were most dense in the MCL (median [range], 319 [118-538] cells/mm 2 ) and LDET (331 [61-463]), whereas cells with ovoid nuclei were most dense in the CaCL (276 [123-368]) and CrCL (212 [165-420]). The spheroid nuclear phenotype had the lowest density in all structures (31 [5-61] in CaCL, 54 [5-90] in CrCL, 2 [0-14] in MCL, and 5 [0-80] in LDET); however, the CrCL contained a denser population of spheroid cells compared with MCL and LDET (P < .05). Total cell densities did not differ among the 4 structures (P > .05). Conclusion: Phenotype density varied within the ligaments and tendon tested here. The cell population of CaCL and CrCL differed from that of dense collagenous tissues such as MCL and LDET. Clinical significance: The relatively higher density of spheroid phenotype in CrCL may reflect a distinctive native cellular population or a cellular transformation secondary to unique mechanical environment or hypoxia. This intrinsic cellular population may explain altered tissue properties prone to pathological rupture or poor healing potential of the canine CrCL.

Linear external skeletal fixation applied in minimally invasive fashion for stabilization of nonarticular tibial fractures in dogs and cats

“…Pin‐tract morbidity remains one of the most important complications of ESF, compromising otherwise successful treatment. 1 It was reported in 18 of 55 (33%) cases. Cultures of the pin tract were not performed in any of the cases that developed pin‐tract erythema, swelling, and/or discharge.…”

“…Despite the benefits of ESF for minimally invasive osteosynthesis, its use for this purpose may also lead to complications associated with interference with soft tissues, more demanding postoperative care, and pin loosening. 1 In a recent retrospective study by Beever et al 19 evaluating postoperative complications associated with ESF in dogs, a complication rate of 69% was reported. However, the region of ESF placement was associated with complications and the tibia was reported to have the lowest complication rate (41%) and the complications were mostly minor.…”

“…Fractures of the tibia are relatively common in dogs and cats, and account for 10%‐20% of all fractures. 1 Multiple methods of tibia fracture fixation have been described including open reduction and internal fixation as well as minimally invasive options. 2 , 3 , 4 , 5 , 6 , 7 Open techniques allow for fragment observation and reduction via direct manipulation; however, they have been associated with compromise to the blood supply, which may inhibit bone healing and increase complications.…”

Functional Anatomy of the Craniolateral and Caudomedial Bundles of the Caudal Cruciate Ligament in Beagle Dogs

“…In addition, a recent study elucidated the similarities and differences in cellular population between canine caudal cruciate ligament and cranial cruciate ligament. 28 This may partly explain why isolated rupture of the caudal cruciate ligament is uncommon, and the cranial cruciate ligament rupture is common. Thus, the results of this study contribute to understanding of the biomechanics and the function of the caudal cruciate ligament, which built a foundation to investigate the association with pathophysiology of the caudal cruciate ligament tear.…”