DE QUERVAIN'S DISEASE

Tenosynovitis of the first extensor compartment is called De Quervains tenosynovitis.

Compartment contains Ab Pollicis Longus and Ext pollicis brevis Usually a single sheath envelops both tendons but occasionally a septation separates the tendons Tendons divide into multile bundles distal to radial styloid Divisions should not be misdiagnosed as delamination

Overuse injury, repetitive thumb action or grasping predisposes Especially common in lactating mothers In many cases, the only sign evident is thickening of the extensor retinaculum

This accounts for the alternative name sclerosing tenosynovitis.

Occasionally a small erosion can be identified in the adjacent radius on X Ray.

This allows a plain film diagnosis of de Quervain’s tenosynovitis particularly if associated soft tissue swelling can be seen On MRI, a small quantity of fluid around the tendon is considered normal Fluid should not exceed the total diameter of fluid should not exceed the diameter of the tendon MRI is poor at assessing the thickened retinaculum unless it is marked

Thus US in a better imaging test

Ultrasound is also capable of demonstrating many of the findings associated with de Quervain’s tenosynovitis.

Thickening of the retinaculum is easily identified and often more obvious than on MRI.

Thus US may diagnose the disease at an earlier stage.

Increased Doppler signal of the retinaculum is also common.

The differential diagnosis of radial sided pain includes intersection syndrome and Wartenbergs syndrome

INTERSECTION SYNDROMES

Classic intersection occurs where dorsal compartment 1 croses compartment 2 This crossover point lies approximately 5-6cm proximal to de Quervain’s point Typically occurs in rowers so often called Rowers wrist

The condition is so well known amongst rowers that imaging is rarely considered necessary.

Also seen in motorcross and other sports where repetitive flexion/extension is involved Increased MR signal in and around the crossover area is seen

Gadolinium enhancement may help with the diagnosis.

Ultrasound findings can be more subtle than MR The presence of crepitus as the probe is passed over the crossover point is an important clue There is a second more distal crossover point where dorsal compartment 3 crosses 2 This is less common and often seen in conjunction with other tendon disease and systemic arthropathy

Wartenbergs syndrome is compression of the radial nerve as it crosses to the dorsal aspect of the distal forearm Occasionally this is referred to as an intersection or crossover syndrome

There is a synovial sheath surrounding each of the flexor tendons.

These are separate from the tendon sheath surrounding the flexor tendons within the carpal tunnel.

Inflammatory changes within the tendon manifests with increased fluid and, with progress of disease, increased vascularity and thickening of the synovial lining.

Magnetic resonance imaging in the sagittal plane with high-resolution coils are best employed for the assessment of flexor tendon disease.

Gadolinium enhancement helps to identify more subtle disease and is useful for recognising associated joint involvement.

On ultrasound, the earliest manifestation is the appearance of the dark halo around the tendon.

This is best appreciated on axial images, especially by comparing the affected finger with those that are not involved.

In long axis fluid and synovial thickening will gather in the areas between the flexor pulleys

FCR

The tendon of flexor carpi radials passes on the radial aspect of the wrist within its own fibrous tunnel that is separate from the carpal tunnel.

It inserts into the base of the second metatarsal.

During its passage across the carpus it passes close to the distal pole of the scaphoid.

Injuries to the scaphoid tubercle may be associated with FCR tendinopathy but STT OA is more common

Tenosynovitis presents as fluid filling the tendon sheath which extends from the insertion to approximately the level of the radio carpal joint.

The Radial side extensor tendons are prone to impingement from volar plate screws This occurs if the screws are too long, but more commonly when collapse occurs at the fracture site due to osteoporosis

EXTENSOR CARPI RADIALIS

Paired tendon group Extensory carpi radialis and longus Occasionally involved with tenosynovitis and tendonopathy MOre susceptible to injury from vlar plate surgery

Overlong screws, osteopaenic bone or late onset osteoporosis can result in screw penetration into the tendons See video clip below