Medical Analysis Report

I. Imaging Findings

Based on the provided X-ray images of the right knee, the prosthesis appears generally well-positioned following right knee arthroplasty, with no obvious signs of loosening. There is no pronounced bone destruction or fracture around the joint. A slender, arc-shaped abnormal density is detectable in the suprapatellar bursa area, distinct from surrounding tissue density, raising a suspicion of a retained foreign body. The shape is elongated and located above the joint cavity or in the extended joint region. Considering the clinical context, it is highly suggestive of a retained tubular foreign body.

II. Potential Diagnoses

• Postoperative Retained Foreign Body: Based on clinical and radiological findings, the foreign body shape is consistent with a drainage tube or other plastic material. Given the patient’s postsurgical status, the most likely diagnosis is a foreign object left behind during surgery or related procedures.
• Infection in the Surgical Area: Although infection cannot be entirely ruled out based on imaging alone, the current X-ray shows no obvious bone destruction or lytic changes around the prosthesis. However, any unexplained pain post-surgery should raise the suspicion of infection, warranting further laboratory and clinical evaluations.
• Mechanical Prosthesis Issues: Prosthesis loosening or wear could lead to symptoms, but in this case, the prosthesis position and fixation appear acceptable on X-ray, so this is not a primary consideration.

III. Final Diagnosis

Considering the patient’s age, history of right knee replacement surgery, imaging features, and postoperative onset of pain, the most likely diagnosis is:

Postoperative retained foreign body (residual drainage tube fragment in the context of right knee arthroplasty).

If infection is ruled out clinically (e.g., normal blood tests, inflammatory markers, and synovial fluid analysis), and if combined with operative or postoperative procedural records and examination of any extracted surgical material, the source of the foreign body can be confirmed.

IV. Treatment and Rehabilitation Plan

1. Treatment Strategy:

• Surgical Removal of the Foreign Body: If the foreign body is confirmed to be a fragment of the drainage tube, arthroscopy or a small incision surgery under strict sterile conditions may be considered to locate and remove the foreign body. This prevents ongoing joint irritation and potential synovial inflammation or infection.
• Infection Screening and Management: Prior to and following surgery, complete blood counts, C-reactive protein, and erythrocyte sedimentation rate tests are recommended. Appropriate antibiotics should be administered if infection is present. If arthroscopy reveals significant synovial hyperplasia or purulent material, thorough debridement is advised, with samples sent for pathology and microbiological analysis.
• Prevention of Complications: After removal of the foreign body, attention should be given to maintaining knee joint range of motion, soft tissue healing, and muscle strength recovery. If needed, dependent on intraoperative findings, drainage or short-term external fixation may be arranged.

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

• Frequency: In the early postoperative period, basic functional exercises are recommended 2–3 times per day. As soft tissue reactions subside, frequency can gradually decrease to 3–5 sessions per week on a regular basis.
• Intensity: Begin with low-intensity exercises that avoid excessive joint loading and pain. Exercises may include walking on level ground, isometric contractions in a seated or supine position, and avoiding deep squatting or heavy load-bearing.
• Time: Each training session should last 10–15 minutes initially, gradually increasing to about 30 minutes per session in segments, depending on pain and swelling control.
• Type: Focus on range-of-motion exercises for the joint and strengthening the quadriceps, hamstrings, and other key muscle groups. Early stages may involve continuous passive motion (CPM) combined with assisted active exercises. Progress to active resistance training such as straight-leg raises and standing ankle dorsiflexion/plantarflexion.
• Progression: As postoperative joint function improves and pain or swelling stabilizes, gradually increase resistance and range of movement. Examples include stepping onto a low platform and using knee-extension machines in a seated position. If notable pain or swelling arises upon increasing difficulty, reduce intensity and adjust the plan.
• Volume & Individualization: Develop a tailored regimen based on the patient’s age, preexisting joint function, and overall tolerance level. Avoid overtraining that could result in secondary injuries or excessive fatigue.

Disclaimer

This report is a reference-based analysis derived from the provided medical history, imaging data, and common clinical management principles. It does not replace a professional, in-person diagnosis or treatment plan. If you have further questions or if the condition changes, please consult a specialist physician promptly and follow their professional recommendations.