Research on the Pathogenesis and Therapeutic Targets of Articular Cartilage Degeneration in Osteoarthritis

Inclusion criteria

Osteoarthritis group:

• Meets the American College of Rheumatology (ACR) diagnostic criteria for osteoarthritis: ① Persistent knee pain for ≥1 month; ② X-ray shows osteophytes at the knee joint margin; ③ Age ≥50 years; ④ Morning stiffness <30 minutes; ⑤ Knee joint friction sounds. (Diagnosis requires item ① plus any two of items ②-⑤).
• Radiographic Kellgren-Lawrence (K-L) grade ≥2;
• Complete the entire treatment course without interruption or modification of the treatment plan during the process;
• Complete the full-process assessment and follow-up;
• The image and medical record materials are complete.

Normal control group:

Normal Control Group (subjects must meet criteria for one of the following two sources):

(1) Source A - Non-arthritic surgery patients:

1)No history of knee osteoarthritis, rheumatoid arthritis, gouty arthritis, infectious arthritis, or other joint diseases 2)Undergoing surgery for one of the following indications:

• Femoral neck fracture (Garden type I/II) treated with artificial femoral head replacement
• Simple meniscus injury or ligament injury requiring knee arthroscopy 3)Preoperative X-ray of the joint from which cartilage will be collected shows normal joint space, K-L grade 0, and no osteophytes, subchondral sclerosis, or cystic change (hip joint for femoral head replacement; knee joint for arthroscopy) 3)Intraoperative macroscopic observation or specimen evaluation confirms smooth cartilage surface with no softening, fissure, or fibrosis (Outerbridge grade 0) 4)Complete imaging and medical records available

Source B - Traumatic amputees:

• No history of any joint disease (knee osteoarthritis, rheumatoid arthritis, gouty, infectious arthritis, etc.)
• Undergoing amputation of a lower limb purely for traumatic reasons, with no pre-existing joint pathology in the limb to be amputated
• Preoperative X-ray of the target joint (typically knee or hip) shows K-L grade 0 and no signs of osteoarthritis
• Intraoperative macroscopic evaluation of the articular cartilage from the amputated limb confirms Outerbridge grade 0 (smooth, intact surface)
• Complete imaging and medical records available Both sources: Signed informed consent for voluntary participation

Exclusion criteria

① Combined with other types of joint diseases, autoimmune diseases or bone metabolic diseases;

② Has a history of drug abuse;

③ Those who have not signed the informed consent form;

④ Suffering from mental illness and unable to cooperate with research;

⑤ Other personnel who are not suitable to participate in the research.