Medical Imaging Analysis Report

I. Imaging Findings

Based on the provided X-ray images of both knees in the anteroposterior and lateral views, multiple round or nearly round dense shadows can be seen in the left knee joint. These are distributed within the joint cavity, including the suprapatellar bursa and the synovial regions around the joint. The shapes and sizes vary, with some displaying higher density, consistent with free bodies that have undergone calcification or ossification. The right knee appears normal, with no similar lesions observed. The continuity of the articular surface bone is generally intact, but mild changes on the distal femoral articular surface of the left knee indicate the presence of mild degenerative changes. No obvious narrowing of the joint space is noted. According to intraoperative findings, multiple scattered masses were removed; macroscopically, they appear spherical or nearly spherical, vary in size, and some show layered structures.

II. Potential Diagnoses

• 1. Synovial Osteochondromatosis
  Multiple intra-articular loose bodies, especially a large number of calcified or ossified bodies, commonly arise from synovial proliferation forming multiple osteochondral nodules. These nodules are covered by synovium and accumulate in the joint space, matching the imaging characteristics and clinical presentation in this case.
• 2. Osteochondritis Dissecans
  Often involves detachment of bone-cartilage fragments from the articular weight-bearing surface, forming loose bodies. Typically, the number of loose bodies is smaller, and an obvious bone-cartilage defect is usually noted on the articular surface. While there are mild degenerative changes in this case, no typical osteochondral detachment or defect is seen, and the number of loose bodies far exceeds what is typical for osteochondritis dissecans.
• 3. Degenerative Joint Disease with Loose Bodies
  Advanced knee osteoarthritis can produce intra-articular loose bodies (e.g., detached osteophytes), but these are usually smaller in size and fewer in number. The high number of loose bodies in this case is not typical of simple degenerative joint disease.

III. Final Diagnosis

Taking into account the clinical history (intellectual disability, diabetes, and delayed detection due to communication difficulties), the imaging findings (numerous dense intra-articular shadows of varying sizes), arthroscopic confirmation of multiple bony or cartilaginous loose bodies, and the observed layered encasement upon cross-section, the most likely and fitting diagnosis is:

Synovial Osteochondromatosis.

If further confirmation is needed, pathological examination may be considered. Typically, it would reveal proliferative synovium with the formation of cartilaginous or bony tissue.

IV. Treatment Plan and Rehabilitation Program

1. Treatment Strategies

• Surgical Treatment: Arthroscopic debridement is the main approach, allowing removal of intra-articular loose bodies and partial synovectomy to prevent further proliferation. If there is evident cartilage damage or joint degeneration, cartilage repair or other reconstructive procedures can be considered.
• Conservative Treatment: If clinical symptoms are mild, and the number of loose bodies is small or the surgical risk is significant, observation, joint mobility guidance, and joint support (e.g., bracing) may be considered. However, given the large number of loose bodies and functional impairment in this case, arthroscopic debridement is still recommended.
• Medication: There is no specific pharmacotherapy, but nonsteroidal anti-inflammatory drugs (NSAIDs) can be used for symptomatic relief of pain and inflammation. In cases of poorly controlled blood sugar, better glycemic management should be ensured to promote healing.

2. Rehabilitation/Exercise Prescription Suggestions (FITT-VP Principle)

Postoperative rehabilitation should focus on restoring joint range of motion, muscle strength, and gradually resuming weight-bearing activities. The progression can be guided as follows:

• Frequency (F): 3-5 times per week, gradually increasing according to recovery.
• Intensity (I): Begin with low-resistance or isometric exercises to avoid excessive joint loading. Progress to gentle resistance exercises (e.g., resistance bands, light weights) in the later stages.
• Time (T): Each session of 20-30 minutes, possibly split into multiple shorter sessions to prevent fatigue.
• Type (T):
  • Joint mobilization exercises and passive range-of-motion exercises
  • Seated or semi-reclined leg raises (isometric and isotonic quadriceps training)
  • In the later stages, incorporate low-impact aerobic activities such as stationary cycling or swimming
• Progression (P): Increase training load and range of motion as the knee joint function improves. Balance training under the guidance of a physical therapist may be introduced if necessary.

Special Considerations: For patients with diabetes, closely monitor blood glucose levels to prevent postoperative wound-healing complications. In addition, pay attention to safe weight-bearing and daily activities.