1. Radiological Findings

From the provided anteroposterior and lateral X-ray images of the knee joint, there is no obvious fracture line or bony abnormality. The articular surfaces appear generally smooth, and the joint space is largely symmetrical. No distinct abnormal calcification is seen in the soft tissue. Overall, the plain films make it difficult to evaluate the soft tissues and menisci.

MRI sequences show:

• An abnormal signal in the Anterior Cruciate Ligament (ACL), with partial discontinuity or disorganized fibers suggestive of a tear or at least a partial tear.
• Thickening of the Medial Collateral Ligament (MCL), with localized signal increase indicating a sprain or tear.
• An abnormal high signal on T2-weighted images extending to the articular surface in the posterior horn of the medial meniscus and the lateral meniscus, suggesting meniscal injuries. Both medial and lateral menisci may be torn, which should be confirmed by clinical symptoms and physical examination.
• A small amount of joint effusion in the articular cavity.

2. Potential Diagnoses

1. O’Donoghue’s Triad (Unhappy Triad)
   Classically defined as an ACL tear, an MCL tear, and a medial meniscus tear. However, subsequent studies have found that many similar injuries actually involve the lateral meniscus or a combined bilateral meniscal tear. In this case, considering MRI suggests ACL and MCL involvement as well as meniscal tears, O’Donoghue’s Triad is an important differential to consider.
2. Complex Knee Ligament and Meniscal Injury
   Concomitant injuries to the ACL and MCL often occur with meniscal tears (especially of the lateral meniscus). It is important to be vigilant about possible bilateral meniscal injuries. Clinically, such injuries are often caused by twisting or forceful impact on the knee during sports.

3. Final Diagnosis

Combining the patient’s history of trauma (knee twisting while playing football), imaging findings, and literature, the most likely diagnosis is: “Anterior Cruciate Ligament (ACL) tear, Medial Collateral Ligament (MCL) tear (or injury), combined with a meniscal tear”, i.e., an O’Donoghue’s Triad-type injury. Notably, MRI also suggests possible involvement of the lateral meniscus, and an arthroscopic examination is recommended for further clarification.

4. Treatment Plan and Rehabilitation Guidelines

Treatment Plan:

• Conservative Treatment: If the ligament tear is incomplete and knee stability is acceptable, bracing, physical therapy, and regular follow-ups can be attempted. However, for active patients or those with significant knee instability, long-term conservative treatment may be limited in efficacy.
• Surgical Treatment: For a complete ACL tear or significant meniscal damage, surgical intervention is often required. Knee arthroscopy can be utilized for ligament reconstruction and meniscal repair (suturing or partial meniscectomy). Severe MCL injuries may also require simultaneous repair or augmentation.

Rehabilitation and Exercise Prescription (FITT-VP Principle):

1. Early Phase (postoperative or acute phase, 1–2 weeks):
   ・Frequency: 2–3 short sessions per day of mild exercises
   ・Intensity: Use knee braces or supports to protect the joint, performing only passive or guided active low-range movements
   ・Time: 5–10 minutes each time, pay close attention to pain levels and avoid overexertion
   ・Type: Primarily isometric quadriceps exercises, ankle pumps, straight leg raises, and other low-intensity exercises
   ・Progression: Gradually increase range of motion while maintaining joint stability
2. Intermediate Phase (postoperative or 4–6 weeks post-injury):
   ・Frequency: 3–4 times per week with guidance from a physical therapist
   ・Intensity: Allow partial weight-bearing exercises, such as brief standing and walking with bracing
   ・Time: 15–20 minutes each session, progressively extending to 30 minutes
   ・Type: Range of motion exercises, seated/supine knee flexion and extension, progressive strengthening of the quadriceps and hamstrings
   ・Progression: Increase joint range of motion and weight-bearing according to soft tissue healing and pain tolerance
3. Late Phase (postoperative or 8–12 weeks post-injury and beyond):
   ・Frequency: 3–5 times per week, including targeted strengthening and balance training
   ・Intensity: Gradually progress to moderate or moderately high intensity under professional supervision
   ・Time: 30–40 minutes per session, adjusted based on joint function recovery
   ・Type: Closed-chain exercises (such as half squats, seated/standing leg exercises), balance board training, core strengthening, and gradually introducing single-leg support
   ・Progression: If returning to sports, transition to running, jumping, and other dynamic training after adequately strengthening the core, hip stabilizers, and proprioception

During the rehabilitation process, carefully monitor for any swelling, pain, or changes in joint stability. If unusual pain or a decline in joint function occurs, seek medical advice promptly or adjust the training regimen.

5. Disclaimer

This report is a reference based on the existing imaging and clinical information and cannot replace an in-person consultation or the advice of a specialized physician. Specific treatment and rehabilitation plans must be made under the guidance of a specialist after a thorough evaluation. Patients are advised to follow medical advice and attend regular follow-ups.