Table 2.
Clinical, radiographic and treatment parameters for canine and human anterior cruciate ligament (ACL) rupture
| Parameter | Canine ACL rupture | Human ACL rupture |
|---|---|---|
| Diagnosis | Clinical and radiographic | Clinical and radiographic |
| Symptoms | Knee pain and instability | Knee pain and instability |
| Screening test | Anterior drawer, tibial compression | Anterior drawer, Lachman, pivot-shift |
| Radiographic effusion | ||
| Before diagnosis | Yes | No |
| At diagnosis | Yes | Yes |
| After diagnosis | Yes | Yes |
| Radiographic OA | ||
| Before diagnosis | Typical | Atypical |
| At diagnosis | Typical | Atypical |
| After diagnosis | Yes | Frequently at long-term follow-up |
| Detection of ACL fiber rupture and secondary signs | MR imaging | MR imaging |
| Prediction of disease progression from incomplete to complete ACL rupture | Knee radiography | None |
| Arthroscopic ligament findings | Fiber rupture in both ACL bundles and PCL | Fiber rupture in both ACL bundles |
| Other arthroscopic findings | Synovitis, articular cartilage fibrillation and softening, meniscal tear, periarticular osteophytes | Synovitis, articular cartilage fibrillation and softening, meniscal tear |
| Histological changes in the ACL | Loss of collagen fibers and fiber crimp, chondroid transformation of ligament fibroblasts | Loss of collagen fibers and fiber crimp, chondroid transformation of ligament fibroblasts |
| Conservative treatments | Physiotherapy, activity modification, knee brace occasionally | Physiotherapy, activity modification, knee brace |
| Surgical treatments | Stabilization by tibial osteotomy or extracapsular suture | Stabilization by ACL reconstruction with intraarticular graft. Repair of proximal ACL avulsion, extraarticular augmentationa |
ACL anterior cruciate ligament, PCL posterior cruciate ligament, OA osteoarthritis, MR magnetic resonance; aLess commonly used/investigational