OA is a multifactorial disease, implicating several tissues and systems. Each is affected differently and responds variably to therapy. This landscape underlines a vital lesson: while some elements of OA (structural damages) are hard to influence once established, other pathological changes remain amenable to intervention, especially if detected and treated early (Table 1).

OA pathology and pain are not always synchronised; an animal can exhibit significant pain with relatively mild radiographic changes or appear stoic even as severe structural compromise occurs. This “asynchronous” nature means clinicians must focus as much on pain behaviour and function as on joint appearance.

A successful management plan should account for:

Ongoing cartilage loss and bone changes. Once structural integrity is lost (“eburnation”), cartilage is exceedingly difficult to regenerate; interventions here are focused on preventing further loss. Changes such as subchondral sclerosis and osteophyte formation are hard to reverse, but aggressive management might slow their progression.

Inflammatory and fibrotic changes within the synovium. The synovium—the lining of the joint capsule—plays a pivotal part in OA pathology by mediating inflammation, swelling, and pain. In OA, the synovium becomes infiltrated by inflammatory mediators, leading to pain hypersensitivity due to upregulation of nociceptors (pain receptors) and chronic fibrosis of the joint capsule. Recent advances directly target this biology, leading to profound pain relief for some chronically affected patients. This molecular understanding increasingly informs both diagnostics and therapeutics.

Emerging or entrenched neuropathies. Peripheral sensitisation and central nervous system plasticity (maladaptive pain processing) can sometimes be reversed or limited with judicious management, including use of specific analgesics targeting neuropathic pain

Progressive muscle wasting, adiposity, and functional loss. Muscle wasting and replacement by fibrous tissue (disuse atrophy and fibrosis) are modifiable through targeted rehabilitation, while obesity and adiposity are reversible through controlled diet and exercise.

From this synthesis of anatomy, pathology, and pain biology, several actionable insights emerge:

• Pain control is critical, yet the underlying disease deserves ongoing attention to halt or reverse secondary pathologies wherever feasible.
• The essential factor of OA management remains treating active tissue injury and inflammation.
• While cartilage dystrophy may be irreversible, synovial pathology, neural sensitization, muscle or fat-driven problems can often be improved or reversed with prompt and attentive care.