A Pictorial Review Of Wrist Injuries In The Elite Golfer (P3)
Dorsal Wrist Injury
Dorsal Rim Impaction Syndrome (DRIS)
DRIS (also known as hypertrophic synovitis) is a type of carpal impingement syndrome which predominantly affects the trailing wrist in elite golfers. Dorsal impaction syndromes are also seen in athletes, notably gymnasts, weightlifters and those who do excessive press ups. It is caused by forced dorsiflexion or repetitive hyperextention particularly when accompanied by axial loading. In golfers continued impaction of the dorsal radial rim on the lunate and scaphoid when the club hits the ground can result in dorsal capsular hypertrophic synovitis . Clinical impingement occurs when the thickened dorsal wrist capsule becomes trapped and pinched between the radius, extensor carpi radialis brevis and the dorsal ridge of the scaphoid. A degenerative cascade can then ensue with subchondral cyst formation and bone oedema preceding radial and carpometacarpal osteophytosis but extreme progression is rarely seen in elite golfers as painful soft tissue impingement usually results in clinical presentation and treatment. DRIS presents with dorsal central wrist pain and specifically point tenderness in the radiolunate joint centred at the radiolunotriquetral ligament. The pain is exacerbated by hyperextention. In golfers it is caused by repeated loaded hyperextension of the trailing wrist. Plain xrays and CT are usually normal as this condition, at least initially, is a capsular soft tissue abnormality. Dorsal capsular thickening can be shown on ultrasound or MR imaging but in our experience MR imaging is more reliable in documenting its extent as weell as any concomitant injuries or bone marrow changes elsewhere in the wrist. Capsular thickening and synovitis typically occurs dorsal to the scaphoid and lunate surrounding the extrinsic ligaments and extending inferiorly to the radius. The thickened tissue is low to intermediate signal on MRI T2 weighted images and is rarely markedly oedematous. Joint fluid usually outlines the irregular contour of the thickened capsule and synovitis. On ultrasound the thickening is usually hypoechoic and nodular but rarely shows any Doppler signal. Ultrasound is useful for guiding needle placement into the nodular tissue for therapeutic injection.
A carpal boss is the description for a bony protruberance localised to the carpometacarpal region at the base of the index and middle finger metacarpal bones (the quadrangular joint). Bossing can result in significant morbidity and time away from practice and play for the golfer. Repetitive strain, specifically forced wrist extension, is thought to aggravate bossing symptoms due to adjacent tenosynovitis of the extensor carpi radialis longus and brevis at their basal insertions on the dorsal aspect of the second and third metacarpals. The diagnosis of carpal bossing is made on clinical and imaging findings after ruling out various differential diagnoses. Ganglion cysts are the most common cause of dorsal wrist protuberances. The differential diagnosis between a ganglion and carpal bossing is based on location and palpation. Between 60 and 70% of all ganglions occur over the scapholunate ligament while carpal bossing is always over the quadrangular joint. The aetiology of carpal bossing remains uncertain.
everal mechanisms such as ununited fracture, chronic stress/periostitis, instability, accessory ossicles (os styloideum), ligamentous microrupture,, degeneration and partial bony coalition have been postulated as possible causative factors however the evidence underlying these possible mechanisms remains limited. When bossing is present on radiographic imaging, there is typically no sclerosis or reduction of joint space suggesting that a degenerative aetiology is unlikely. It should also be remembered that this feature can be seen in asymptomatic patients and is not always relevant to wrist pain unless the clinical features correlate to this area. Plain x-rays can be diagnostic for its presence but if negative because of bony overlap CT or MR imaging can define the bossing. MR imaging should be performed routinely in elite golfers as this technique can also demonstrate associated bone marrow oedema, fracture, soft tissue oedema and/or tendon abnormality.