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
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
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
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
