Radiological Findings

Based on the provided anteroposterior and lateral X-ray images of the right knee joint, the following main features are observed:

• Calcification within or under the cartilage is visible within the joint space, suggesting possible calcium salt deposition in the cartilage matrix or along its edges.
• No obvious signs of acute fractures are noted around the knee joint.
• The joint surfaces appear relatively clear in contour, though mild degenerative changes (such as subchondral sclerosis or small osteophytes) can be seen.
• There are no clearly visible large soft tissue swellings or significant calcifications in the soft tissue; the main changes are concentrated on the articular cartilage surface.

Potential Diagnoses

Based on the patient’s clinical presentation (acute joint pain, swelling) and radiological findings (cartilage or subchondral calcifications), the following diagnoses and differentials should be considered:

1. Pseudogout (CPPD-related arthritis): Cartilage and subchondral calcifications are common in pseudogout; clinically it can present with an acute onset and features of inflammatory arthritis.
2. Osteoarthritis (OA): In the absence of an obvious acute trigger or crystal confirmation, degenerative joint disease may be considered. However, calcifications in primary OA may not be as characteristic as those in pseudogout.
3. Gout: Though also crystal-related, gout more often affects the first metatarsophalangeal joint or other joints; radiologically, typical findings include soft tissue swelling and “punched-out” erosions of bone. Intra-articular calcifications are not common.
4. Septic arthritis: Clinically, significant redness, swelling, warmth, and pain may be most notable. Radiologically, one might see bone destruction. Current imaging findings are not typical, though infection cannot be completely ruled out without laboratory tests.

Final Diagnosis

Combining the evident cartilage calcifications on the X-ray, acute right knee pain, swelling, and common triggers of acute pseudogout (such as trauma, surgery, or physiological stress), the most likely diagnosis is:

Pseudogout (CPPD arthritis).

Further confirmation can be achieved if calcium pyrophosphate crystals are found in joint aspirate. Additional examinations, such as joint fluid culture and blood tests (e.g., white blood cell count, C-reactive protein), may be necessary to rule out infection or other causes.

Treatment Plan and Rehabilitation

Treatment Strategies:

• Acute Joint Management: First-line treatments include nonsteroidal anti-inflammatory drugs (NSAIDs) or colchicine to control pain and inflammation. If NSAIDs are contraindicated, consider oral or intra-articular corticosteroids.
• Joint Protection and Physical Therapy: Adequate rest and elevation of the affected limb, along with ice application, can reduce swelling and pain. Once pain subsides, early mobilization exercises help prevent stiffness.
• Address Underlying Conditions: If there are metabolic abnormalities (e.g., thyroid dysfunction, calcium/phosphorus imbalance) or a family history, evaluate and treat any potential underlying cause.

Rehabilitation and Exercise Prescription (FITT-VP Principle):

1. Type of Exercise:
   • Initially, when pain has subsided, engage in non-weight-bearing or low-impact activities, such as straight-leg raises, seated knee flexion/extension, and lower limb muscle strengthening.
   • Range-of-motion exercises, such as gentle knee flexion and extension, to maintain joint flexibility.
2. Intensity:
   • Towards the later acute phase or when symptoms have significantly eased, gradually increase resistance training (e.g., using resistance bands) to strengthen key muscle groups like the quadriceps.
   • Avoid excessive loading. If joint pain worsens, reduce intensity or pause.
3. Frequency:
   • 3–5 sessions per week; during the acute phase, it can be reduced to 2–3 sessions. Adjust according to the joint’s response.
4. Duration (Time):
   • Each session can last around 20–30 minutes, potentially split into segments (e.g., 10-minute sessions repeated 2–3 times). Increase gradually based on tolerance.
5. Progression:
   • As joint function improves and pain decreases, progressively increase training volume and resistance. After several weeks, patients can attempt light squats or walking exercises.
   • If needed, conduct therapy with professional rehabilitation specialists, incorporate balance aids, or consider aquatic exercises to reduce joint stress.

Safety Considerations:
Throughout rehabilitation, monitor any changes in joint pain or swelling. If significant redness, swelling, or functional limitation worsens, or if complications are suspected, seek medical evaluation promptly.

Disclaimer: The above report is a reference analysis based on existing data and cannot replace an in-person consultation or the opinion of a qualified physician. Actual diagnosis and treatment should be determined by professional medical staff, incorporating the patient’s specific condition and further test results.