Dorsal radioulnar ligament

Original Editor - Noa Weingarten Top Contributors - Noa Weingarten

Original Editor - User Name

Top Contributors - Noa Weingarten  

Description

The dorsal radioulnar ligament (DRUL) is comprised of parallel collagen bundles divides into deep and superficial limbs, which attach into the fovea and ulnar styloid, spanning across the radius and ulna and forming ,among other structures, the triangular fibrocartilage complex (TFCC) located on the ulnar aspect of the wrist joint between the lunate, triquetrum, and ulnar head.

Attachment

The DRUL connects the posterior margin of the ulnar notch at the distal radius to the posterior portion of the head of the ulna. The ligament innervated by the anterior and posterior interosseous nerve and the anterior interosseous artery supply her blood

function

DRUL acts along with the palmar(volar) radioulnar ligament as primary stabilizers of the dorsal radioulnar joint (DRUJ) and act as a shock absorber across the ulna-carpal joint.

clinical relevance

Traumatic or degenerative Injuries can occur with aging and due to the complexity of the anatomical structure and the way load transmission takes place around the ulnar aspect of the wrist joint. Injury often occurs under forced ulnar deviation. Repetitive forearm rotation, in particular, overuse of DRUL which leads to degenerative changes. The injury prevalence in patients aged 70 or older is 49% and 27% in patients aged 30 or younger.. The DRUL injuries are associated with damage involving the TFCC or other radioulnar ligaments resulting from distal radius fractures, fractures of the ulnar styloid, and eponymous Galeazzi or Essex Lopresti fractures. Injury to the interosseous membrane (IOM) can also put a lot of strain on the DRUL consequently can cause injury to the DRUL.

Assessment

Diagnostic tool: as a preliminary diagnosis MRI imaging is useful ; however arthroscopy is the diagnostic gold standard.

subjective

Patients may complain of dull ulnar-sided wrist pain often worsened with activity, particularly during forearm rotation. However, difficulty carrying loads is the hallmark of injury to the DRUL.

Patient history may includes current or previous injuries or fractures (as mentioned above) Patient may participate sports that include swinging a racket or a bat such as baseball player

Physical examination

The pain is accompanied  by clicking or tender points between the pisiform and the ulnar head. The physical examination reveals Muscle weakness in the grip, supination and pronation, which can then indicate on wrist instability.

There is no specific test for the DRUL but several physical exams test the TFCC can possibly indicate injury to the DRUL and rule out the possible for fractures .

These include:

• TFCC compression test: Pain is reproduced with ulnar deviation while forearm in the neutral position.
• TFCC stress test: Pain is reproduced while applying force across the ulnar while the wrist in ulnar deviation .
• Press test: Pain is reproduced while the patient lifts themselves out of a chair using the wrists in an extended position.
• Supination test: Pain is reproduced while the patient grabs the underside of a table with the forearms supinated.
• Piano key test: Pain and excessive movement are reproduced while while the wrist in pronation, stabilizing the wrist and the radius in one hand at the same time press with the other hand anteroposterior on the distal ulnar styloid process.

Treatment

1. It is important to identify the daily activities aggravating the pain and modify them with the help of professionals such as physiotherapists.

2. Allow rest and completely avoid sports activities that consist of full weight bearing on the wrist while performing maneuver movements such as Yoga poses etc.

2. Application of temporary splint or cast.

3. NSAIDs

4. Administration of corticosteroid injection in conjunction with physical therapy in extremely symptomatic patients.

5.Arthroscopy, a surgical procedure is performed only if the conservative treatment fails to alleviate symptoms, or in cases presenting initially with instability of the DRUJ or with unstable and displaced fractures. In most, if not all conditions involving TFCC, arthroscopic management can be conducted successfully.