Hand Pathology

Bone Pathology

Fractures

• Metacarpal/Phalangeal Fractures: Common in trauma (e.g., boxer’s fracture of 5th metacarpal).

  • MRI Findings: Low-signal fracture line on T1; bone marrow edema on T2 FS/STIR.

• Avulsion Fractures: Often at tendon/ligament insertions.

Osteomyelitis

MRI Findings:

• Bone marrow edema

• Cortical destruction

• Periosteal reaction

• Soft tissue abscess (T2 hyperintense, enhances with contrast on T1 - Fat/Sat helps to visualize this).

Bone Tumors

• Enchondroma: Common benign tumor in phalanges.

  • MRI Findings: Lobulated, T2-hyperintense lesion with chondroid matrix.

Joint and Ligament Pathology

Osteoarthritis

• 1st CMC Joint: Common site due to thumb mobility.

  • MRI Findings: Joint space narrowing, osteophytes, cartilage loss, subchondral cysts/edema.

Rheumatoid Arthritis

MRI Findings:

• Synovitis (T2 hyperintense, enhances with contrast)

• Erosions

• Joint effusion

Collateral Ligament Tears

MRI Findings:

• Discontinuity or abnormal signal in collateral ligaments, often at MCP joints (e.g., gamekeeper’s thumb at 1st MCP ulnar collateral ligament).

rheumatoid arthritis

Collateral Ligament Tears

Tendon Injuries

Tenosynovitis

• An inflammation of the synovium, the sheath that surrounds and protects tendons.

• It can occur in any tendon in the body, but it is most common in the wrists, hands, and feet.

  • MRI Findings: Fluid in tendon sheath (T2 hyperintense), tendon thickening, synovial enhancement.

  • Common in flexor tendons (e.g., trigger finger due to A1 pulley thickening).

Tendon Tears

• MRI Findings: Partial or complete discontinuity, increased T2 signal, retraction in complete tears.

• Common in flexor digitorum or extensor pollicis longus.

Gamekeeper Thumb

Gamekeeper thumb is an injury to the ulnar collateral ligament of the thumb at the level of the first metacarpophalangeal joint.  This injury can occur from skiing or falling on to an outstretched hand. 

Appearance on MRI:

• •

  May show avulsion fracture at the attachment site of the ulnar collateral ligament (one-third of cases).

• •

  Shows tear of the ulnar collateral ligament as a thin, low-signal ligament or discontinuity of the ligament with hemorrhage and edema surrounding the torn ends of the ligament.

Giant Cell Tumor of Tendon Sheath

Giant Cell Tumor of Tendon Sheath

• Common benign tumor.

  • MRI Findings: T1/T2 hypointense due to hemosiderin, enhances with contrast.

Lipoma or Hemangioma

• image is stir demonstrating hemangioma

Lipoma or Hemangioma

• Fat mass or growth of extra blood vessels.

  • MRI Findings: Lipoma (T1 hyperintense, suppresses on fat-sat); hemangioma (T2 hyperintense, vascular flow voids).

Soft Tissue Infections

Soft Tissue Infections

MRI Findings:

• Soft tissue edema

• Abscess formation (T1 hypointense, T2 hyperintense, rim-enhancing)

• Possible bone involvement.