Knee Joint Imaging Analysis Report

I. Imaging Findings

Based on the provided anteroposterior and lateral X-ray images of the knee, the following key features can be observed:

• A small cortical avulsion-type fracture fragment is seen near the lateral margin of the tibial plateau, tending towards the proximal or posterior portion of the lateral tibial plateau.
• The joint space appears relatively normal, with no obvious collapse or large displaced fractures.
• Mild swelling of the periarticular soft tissue is noted, but due to the limited resolution of plain radiographs, detailed soft tissue evaluation cannot be fully assessed.
• Considering the history of a twisting injury and the position/shape of the avulsion fragment, there is a high suspicion of a “Segond fracture” in association with injury to the anterior cruciate ligament (ACL), lateral joint capsule, or lateral collateral ligament complex.

II. Potential Diagnoses

1. Segond fracture: Classically presents as a small avulsion-type fracture of the lateral tibial plateau, often related to varus stress and internal rotation injury of the knee, commonly accompanied by ACL injury.
2. Avulsion injury of the lateral collateral ligament attachment: Occurs at the fibula or lateral portion of the tibia, caused by acute valgus or external rotation-valgus stress. The fracture site typically differs from a Segond fracture.
3. Other soft tissue injuries with a bony avulsion: Such as minor avulsion fractures at the attachment of the lateral joint capsule or iliotibial band. MRI is often required for more precise evaluation.

Given that the patient twisted the knee during sports, and imaging reveals a small avulsion fracture of the lateral tibial plateau, a Segond fracture is most common and is highly correlated with ACL injury, warranting priority consideration.

III. Final Diagnosis

Based on the mechanism of sports injury, the highly suspicious small avulsion fracture of the lateral tibial plateau seen on imaging, and literature reports indicating a strong correlation between Segond fractures and ACL injury, the most likely diagnosis is:

Segond fracture (with a high probability of concurrent ACL injury).

Further knee MRI evaluation is recommended to clarify the extent of potential ACL, meniscal, and other soft tissue injuries.

IV. Treatment Plan and Rehabilitation

The following treatment and rehabilitation approaches may be considered for a Segond fracture and potential ligament injuries:

1. Conservative Treatment (for fractures without significant displacement, partial ligament injuries with acceptable stability):
   • Joint immobilization and brace protection: During the acute phase, use an appropriate knee brace or support to limit excessive rotation and valgus stress.
   • Icing and swelling control: Apply local cold therapy in the early stage after injury and after training to reduce pain and swelling.
   • Short-term use of NSAIDs: Non-steroidal anti-inflammatory drugs can help alleviate pain and inflammation.
2. Surgical Treatment (for significant ACL tears, joint instability, or high-level athletic demands):
   • ACL reconstruction: Based on the degree of injury, perform anterior cruciate ligament reconstruction, and consider repairing or addressing any concurrent meniscal, cartilage, or lateral support structure damage.
   • If the Segond fracture fragment is very small without significant displacement, specific fixation is usually unnecessary. The primary surgical focus is on ligament repair.
3. Rehabilitation/Exercise Prescription Principles (FITT-VP):
   • Frequency: During the acute phase, low-intensity joint mobility and muscle-strengthening exercises can be done daily or every other day. Once fracture and ligament healing are more stable, the frequency can gradually increase from 2–3 times per week to 3–5 times per week.
   • Intensity: Progress from low-intensity exercises (isometric contractions, range of motion exercises) to moderate intensity (weight-bearing exercises, resistance band training) once the fracture has healed. Avoid early high-impact activities.
   • Time: Initially, start with basic exercises for 5–10 minutes per session, pausing if pain or discomfort occurs. As function improves, extend the exercise duration to 30 minutes or more.
   • Type: In early rehabilitation, focus on passive and active range-of-motion exercises, isometric quadriceps strengthening, and balance training. In later stages, include low-impact aerobic activities such as cycling or swimming, and gradually return to running, jumping, and other high-intensity sports.
   • Progression: Increase intensity and complexity based on fracture healing and ligament stability. If ACL reconstruction is performed, follow the postoperative rehabilitation protocol in phases, gradually advancing range of motion and strength.
   • Volume & Individualization: Tailor the overall training volume to the patient’s recovery and consult with medical professionals. For patients with osteoporosis or cartilage damage, reduce weight-bearing and high-impact activities as necessary.

   For athletes or individuals with high functional demands, adequate strength and proprioception training are essential before gradually returning to specific sports.

Disclaimer

This report provides a reference analysis based on imaging and clinical information. It cannot replace an in-person consultation or professional medical advice. A definitive diagnosis and treatment plan should be made in conjunction with other examinations (such as MRI, arthroscopy, blood tests) and clinical evaluations.