Traumatic osteoarthritis-induced persistent mechanical hyperalgesia in a rat model of anterior cruciate ligament transection plus a medial meniscectomy

Abstract

BackgroundOsteoarthritis (OA) is a degenerative joint disease characterized by progressive cartilage degeneration, subchondral bone changes, osteophyte formation, and synovitis. A major symptom is pain that is triggered by peripheral and central changes within the pain pathways. Some surgery-induced joint instability rat models of OA were described to mimic traumatic OA. Several behavioral tests were developed to access OA-induced pain. However, follow-up in most studies usually only occurred for about 4 weeks. Since traumatic OA is a chronic disease which gradually develops after trauma, the pattern of pain might differ between early and late stages after the trauma.PurposeTo observe the time-dependent development of hypersensitivity after traumatic OA and to determine the best timing and methods to investigate traumatic OA-induced pain.MethodsAnterior cruciate ligament transection plus medial meniscectomy was used to induce traumatic OA in Sprague-Dawley rats. Traumatic OA-induced pain was evaluated using four different behavioral tests for 15 weeks.ResultsA significant difference in mechanical hypersensitivity developed throughout the observational period. It was worst in the first 3 weeks after the operation, then became less significant after 5 weeks but persisted. There were no differences in thermal hyperalgesia or motor coordination.ConclusionTraumatic OA induced mechanical hyperalgesia but did not cause thermal hyperalgesia or influence motor coordination. Furthermore, to investigate chronic pain induced by OA, the observational period should be at least 5 weeks after the intervention. These findings may help in further research and improve our understanding of traumatic OA-induced pain mechanisms.

Clinical-like cryotherapy improves footprint patterns and reduces synovial inflammation in a rat model of post-traumatic knee osteoarthritis

“…Finally, the chronicity characteristics of KOA may explain the absence of a cryotherapy effect on both skin temperature and swelling of the knee joint. There were also no changes in thermal hyperalgesia in the KOA model, which is supported by previous studies of the post-traumatic KOA model 47,48 . Behavioral changes commonly reported in the literature involve the assessment of other parameters, such as gait adaptations, mechanical hyperalgesia, mechanical allodynia and weight-bearing asymmetries.…”

Knee osteoarthritis induces atrophy and neuromuscular junction remodeling in the quadriceps and tibialis anterior muscles of rats

“…This result corroborates a recent study that found reduced pain threshold associated with muscle weakness after ACLT 53 . Another recent study showed the presence of persistent mechanical hyperalgesia in a KOA model 54 . Our results strengthen the evidence that pain is related to the inflammatory and neuromuscular changes observed in the KOA.…”

Effects of Pomegranate Concentrate Powder: Eucommiae Cortex: Achyranthis Radix 5:4:1 (w/w) Mixed Formula on Monosodium Iodoacetate-Induced Osteoarthritis in Rats

“…Chemical-OA and surgery-OA models may induce different degrees of pain over time. Multiple methods have been used to analyze pain behaviors 32 ; the Von Frey filament test and open field test are generally used to assess these. At the later stages of MIAinduced OA, the damage to exposed subchondral bone and synovia resembles human OA and is related to joint pain.…”