Medical Imaging Analysis Report

I. Imaging Findings

From the provided pelvic anteroposterior X-ray, CT axial slices, and 3D reconstruction images, the following can be observed:

• The angle between the femoral neck and femoral shaft on both sides is significantly reduced, estimated to be below 120°, suggesting a pronounced inward inclination of the femoral neck axis (i.e., Coxa Vara).
• There are developmental abnormalities in the bilateral hip joints, with shortened femoral necks. No distinct signs of acetabular overgrowth or bone destruction are observed.
• No obvious signs of joint surface degeneration or osteophyte formation; no evident joint space narrowing is noted.
• No significant soft tissue swelling or pathological density shadow is observed. The surrounding soft tissue appears essentially normal.
• No other obvious abnormalities are noted in the remaining pelvic area.

II. Potential Diagnoses

Considering the patient is 21 years old, presents with a painless waddling gait, and exhibits bilateral changes on imaging, possible diagnoses or differential diagnoses include:

1. Congenital Coxa Vara: The most common indication is a bilateral decrease in the femoral neck-shaft angle. Patients often present with unsteady gait or limping in childhood. Imaging features typically show a femoral neck-shaft angle of less than 120° and other proximal femoral developmental abnormalities.
2. Developmental Dysplasia of the Hip (DDH): This can also lead to abnormal gait patterns but usually involves acetabular dysplasia and an abnormal position of the femoral head. In this case, no obvious signs of a shallow acetabulum or other typical DDH changes are noted, making this diagnosis less likely.
3. Other rare deformities due to epiphyseal or cartilaginous developmental anomalies: Conditions such as certain types of chondrodysplasia or metabolic bone diseases may cause abnormal hip morphology, though they often involve additional systemic or multiple skeletal manifestations.

III. Final Diagnosis

Based on the bilateral hip imaging findings, clinical presentation (painless waddling gait), and imaging features (a notably decreased femoral neck-shaft angle, approximately <120°), the most likely diagnosis is:

Congenital Bilateral Coxa Vara.

Currently, there are no evident signs of degenerative changes or joint destruction on imaging, indicating that the hip joints remain relatively stable, although there is a possibility of gradual progression over time.

IV. Treatment Plan and Rehabilitation Program

In light of the characteristics of congenital bilateral coxa vara, the treatment and rehabilitation strategies can be outlined as follows:

1. Conservative Management:
   • If the patient’s daily activities are still manageable without significant pain or mobility restrictions, conservative monitoring may be considered initially.
   • Regular follow-up (e.g., every 6–12 months) is recommended to monitor the femoral neck-shaft angle and joint space, keeping track of any onset of pain or worsening deformities.
2. Surgical Treatment:
   • For patients with a pronounced deformity, severely limited gait function, or a progressive trend toward worsening deformity, an osteotomy (such as a proximal femoral corrective osteotomy) should be considered to restore a normal or near-normal femoral neck-shaft angle and improve weight-bearing alignment and range of motion.
   • If acetabular dysplasia or secondary degenerative changes are detected, additional hip reconstruction procedures may be required accordingly.
3. Rehabilitation & Exercise Prescription:
   • Early Intervention: During conservative or surgical treatment, guided functional training should be initiated as early as possible to prevent further loss of hip range of motion.
   • FITT-VP Principle:
     • Frequency: 3–5 rehabilitation sessions per week, gradually increasing based on the patient’s tolerance.
     • Intensity: Begin with low-intensity joint mobility and small muscle group strengthening exercises. Increase gradually, adjusting to joint stability and pain levels.
     • Time: Each session should last about 20–30 minutes. Initially, prolonged weight-bearing activities should be avoided, with an emphasis on proper form.
     • Type: Focus primarily on low-impact exercises such as hip joint active movements performed in seated or supine positions, and resistance band exercises to maintain quadriceps and gluteal muscle strength. Progress to swimming, cycling, or other whole-body exercises.
     • Progression: As joint range of motion and strength improve, gradually introduce weight-bearing training, such as supported standing balance exercises or simple squats with appropriate support.
     • Volume and Pattern: Adhere to the principle of “small amounts multiple times, gradual transition.” Sessions can be divided into segments to allow adequate rest.
   • Individualized Training: Given the special bilateral hip structure, avoid abrupt rotational or excessive twisting movements. Use supportive devices or walkers when necessary to reduce unnecessary external forces.
   • Daily Living Guidance: Avoid prolonged weight-bearing activities (e.g., long periods of standing, heavy lifting). Pay attention to protective postures for the hips when sitting or sleeping.

Disclaimer: This report is a reference analysis based on the information currently provided and does not replace an in-person consultation with a professional physician or further examinations. If you have any questions or experience changes in your condition, please consult an orthopedic specialist for a more comprehensive diagnosis and treatment plan.