Medical Imaging Analysis Report

1. Imaging Findings

The patient is a 46-year-old female who has experienced pain and swelling on the dorsal side of her right hand for nearly one month. Based on the provided MRI and ultrasound images, the following key features are observed:

• On the T2-weighted MRI sequence, there is noticeable soft tissue edema in the soft tissues around the dorsal side of the right hand near the metacarpophalangeal joint, suggesting acute or subacute inflammatory or injury response.
• In the area of the first phalanx (proximal phalanx) and the dorsal aspect of the corresponding metacarpal head, a linear low-signal structure adjacent to the extensor tendon appears hazy or discontinuous, possibly indicative of a partial tear of the sagittal band.
• Ultrasound examination shows localized disorganized echogenicity or abnormally thickened hypoechoic bands around the extensor tendon on the dorsal side of the metacarpophalangeal joint. Some areas appear to have disrupted continuity, consistent with a sagittal band injury.
• No obvious signs of fracture are noted in the bony structures, and no apparent collapse or displacement of the joint surfaces is observed.

2. Potential Diagnoses

Taking into account the patient’s history of trauma and the imaging findings, possible diagnoses include:

1. Sagittal band tear or injury (“Boxer’s knuckle”)
   Trauma may cause partial or complete disruption of the fibrous tissue of the sagittal band, leading to instability or even subluxation of the extensor tendon at the metacarpophalangeal joint. This typically presents with localized pain, swelling, and limited finger extension.
2. Other soft tissue strains or ligament injuries around the metacarpophalangeal joint
   For instance, injuries to the collateral ligaments or palmar plate could cause pain and restricted joint mobility, often accompanied by joint side-to-side instability or palmar functional impairment. This presentation differs somewhat from a sagittal band injury.
3. Other overuse or tenosynovitis of the extensor tendon insertion
   In the absence of a clearly visible tendon subluxation or sagittal band rupture, it could be localized inflammation of the extensor tendon or tenosynovitis. However, MRI and ultrasound findings already indicate a definite abnormality in the sagittal band, making this less likely.

3. Most Likely Final Diagnosis

Based on the patient’s trauma history, the duration of symptoms, and the imaging findings revealing disruption of the sagittal band’s continuity, the most likely diagnosis is:

Partial tear of the sagittal band (extensor tendon supporting band) on the dorsal side of the right hand, accompanied by surrounding soft tissue edema.

If more precise evaluation of the injury extent is necessary, further high-resolution ultrasound follow-up could be considered, or comparative examinations may be performed if a concurrent ligament injury is suspected. However, the current images and clinical history are sufficient to support this diagnosis.

4. Treatment Plan and Rehabilitation

For a localized tear of the sagittal band, the treatment goal is to reduce local inflammation and restore the stability of the extensor tendon in that region, preventing recurrent injury and functional impairment. Potential strategies include:

• Conservative Treatment:
  • Early use of a splint or brace for short-term immobilization of the metacarpophalangeal joint (usually 2–3 weeks) to minimize tendon displacement and local traction during activities.
  • Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) orally or topically to relieve pain and inflammation.
• Surgical Treatment:
  • In cases of severe injury or clear subluxation of the extensor tendon where conservative management proves ineffective, surgical repair of the sagittal band and reconstruction of extensor tendon stability may be warranted.
• Rehabilitation and Exercise Prescription:
  • Early Phase (Immobilization Period):
    • During the protection phase, static exercises are primarily used to maintain mobility of adjacent joints. For example, gentle wrist flexion and extension exercises can help maintain blood circulation, but any stress on the injured area should be avoided.
    • Gentle “make a fist and extend” finger exercises can be performed daily, limiting the range of motion to avoid significant pain, 3–4 times per day, 10–15 repetitions each time.
  • Intermediate Phase (Post-Immobilization):
    • Gradually increase the range of joint movement, such as active finger flexion and extension in warm water, supplemented by gentle assisted stretches.
    • Each exercise session can be extended from 5 minutes to around 15–20 minutes, performed 2–3 times a day.
    • Use an elastic band for mild resistance training, carefully monitoring local pain and swelling.
  • Late Phase (Strength Recovery):
    • Strengthen the hand and forearm muscles with light hand-gripping or pinching exercises, ensuring movements remain within the patient’s pain threshold.
    • Incorporate functional exercises (e.g., grasping small objects, twisting bottle caps) to restore dexterity and coordination in finer hand movements.
    • During this stage, training volume and resistance can be increased progressively based on individual recovery, following the FITT-VP principle (Frequency, Intensity, Time, Type, Progression, and Individualization).

  Throughout the rehabilitation process, regular follow-up is necessary. If severe joint pain, significant swelling, or other discomfort arises, relevant activities should be immediately paused, and medical evaluation should be sought.

Disclaimer: This report is a reference analysis based on the existing medical history and imaging data. It cannot replace the diagnosis and treatment advice provided by an in-person physician. Patients should develop a final individualized treatment plan based on a comprehensive evaluation by professional healthcare providers.