# Upper Limb Orthotics/Distal Radioulnar Joint Dislocation
## Describe your case study

The patient is a seventeen-year-old female who has experienced an accident whilst riding a horse two days ago. As she fell of her horse she landed on her right hand incorrectly, twisting her wrist. She experiences pain when rotating her forearm and has an excessive prominence of the ulnar head. Medical imaging shows a dorsal displacement ulna head and a partial tear of the triangular fibrocartilaginous complex (TFCC). The patient was diagnosed with an isolated dorsal distal radioulnar joint (DRUJ) dislocation. She is currently not using any medication and is commencing her final year of high-school and wishes to recover as soon as possible in order to complete studies efficiently.

## Written information
### Evidence

ANATOMY
The DRUJ is a complex articulation of the forearm involving the distal ends of the radius and ulna. The ulna is fixed in position as the radius rotates around (Sammer & Chung, 2012, p. 199). Movements of the DRUJ include supination; produced by biceps brachii and supinator and pronation; produced by pronator teres and pronator quadratus (Moore, Dalley & Agur, 2013, p. 806). This synovial joint consists of bony articulations and soft tissue stabilisers. The joint articulations are the sigmoid notch of the radius and the ulnar head. Due to the shape of the sigmoid notch, the joint lacks congruency; therefore soft tissue stabilisers maintain joint integrity (Mulford & Axelrod, 2010, p. 155). The TFCC is the primary stabiliser of the DRUJ, which originates from the radial sigmoid notch and inserts into the ulnar styloid. The TFCC complex consists of articular discs, dorsal and volar radioulnar ligaments, meniscal homologue, ulnar collateral ligament and the extensor carpi ulnaris subsheath (Micucci & Schmidt, 2007, p. 118). DRUJ injuries can be isolated or associated with fractures.
PATHOLOGY
DRUJ dislocations are commonly associated with fractures of the radius or ulna. Intra-articular fractures will disrupt the articulation of the joint. Extra-articular fractures may result in displacement, shortening, angulation or translation of the radius, which can cause DRUJ instability (Sammer & Chung, 2012, p. 199). Although dislocations of the DRUJ often occur in conjunction with fractures, there are also cases of isolated dislocations (Wassink, Lisowski & Schutte, 2009, p. 141; O'Brien & Thurn, 2013, p. 287-288). Common mechanisms of injury for DRUJ dislocations include; forced pronation/ supination, direct force to the ulna/ radius or fall on an outstretched hand (Wassink, Lisowski & Schutte, 2009, p. 143; Mulford & Axelrod, 2010, p. 156). DRUJ dislocations may involve damage to the primary stabiliser. Injury to the TFCC increases in severity in relation to force (Melone Jr & Nathan, 1992, p. 495-496), this will affect the stability of the joint. DRUJ dislocations can be stable or unstable, reducible or irreducible. Stable dislocations only have instability in particular positions and may have strains to the TFCC (Mulford & Axelrod, 2010, p. 156-157). Unstable dislocations have instability in all positions and are commonly associated with rupture or avulsion of the TFCC from ulnar styloid (Thomas & Sreekanth, 2012, p. 497). Irreducible DRUJ dislocations have underlying factors, such as soft tissues or bone, that block reduction (Mulford & Axelrod, 2010, p. 158). Untreated dislocations can lead to chronic instability or reduced range of motion. Depending on severity of the dislocation and other components involved, bone or soft tissue, appropriate treatment plan would be prescribed.
SPECIFIC TO CASE STUDY
Isolated dislocations of the DRUJ can be classified as volar, or dorsal (O'Brien & Thurn, 2013, p. 288). Dorsal DRUJ injuries can be caused by; forced pronation, direct force to the ulna driving it dorsally, direct force to the radius driving it parmarly or fall on an outstretched hand with pronation forces (Wassink, Lisowski & Schutte, 2009, p. 143; Mulford & Axelrod, 2010, p. 156). Dorsal DRUJ dislocations present with limited forearm pronation and an excessive protrusion of the ulnar head (Thomas, & Sreekanth, 2012, p. 494; Mulford & Axelrod, 2010, p 156-157). The stable position for dorsal DRUJ dislocations is in forearm supination.

### Orthotic treatment options

Orthotic treatment is used to immobilise relevant joints and maintain correct alignment. For DRUJ dislocations above elbow, below elbow and wrist orthoses can be prescribed.
ABOVE ELBOW
Above elbow orthotic treatment, with trim lines proximal to the elbow and distal to the wrist are used to immobilize the elbow, forearm and wrist. These could include splints, braces and casts. In stable DRUJ dislocations, instability is only apparent in particular ranges of forearm rotation. Typically for dorsal dislocations, the joint is most stable in forearm supination, where as for volar dislocations the joint would be stable in forearm pronation (Mulford & Axelrod, 2010, p. 156-157; Ellanti & Grieve, 2012, p. 72). Immobilising the arm in the stable position will reduce stretch of ligaments, encourage healing and prevent pain (Micucci & Schmidt, 2007, p. 120-121). This treatment method can be used as a conservative treatment or as post-surgical management.
BELOW ELBOW
Below elbow brace/ cast, with trim lines distal to the elbow and distal to the wrist will immobilise the wrist but still allow full elbow range of motion and certain degrees of pronation and supination (Ellanti & Grieve, 2012, p. 72). In practice below elbow management is commonly used after several weeks of using above elbow immobilisation.
WRIST
A wrist brace, with trim lines distal to the elbow and proximal to the wrist will allow full elbow and wrist range of motion. O'Brien & Thurn (2013) suggests that an ideal functional orthosis will maintain alignment of the radius and ulna as well as stabilise the DRUJ. This treatment method aims to prevent excessive translation of the radius and ulna during forearm pronosupination (O'Brien & Thurn, 2013, p. 287-288).

### Comparison of treatment options

Depending on the type of dislocation and bony or ligamentous structures involved a variety of treatment is available.
Conservative treatment to manage DRUJ dislocations is often considered first (O'Brien & Thurn, 2013, p. 287-288). Stable dislocations usually have strains or tears to the TFCC and therefore are able to heal without surgical intervention. Common treatment for acute, stable dislocations consists of reduction under general anesthesia, followed by orthotic management or casting, to maintain correct alignment (Wassink, Lisowski & Schutte, 2009, p. 141; Mulford & Axelrod, 2010, p. 158). Literature discusses three different orthotic options; above elbow, below elbow, wrist orthoses and casts. Above elbow immobilisation prevents movements of the wrist, forearm and elbow, holding the DRUJ in a position of rotational stability (Mulford & Axelrod, 2010, p. 158). Below elbow treatment immobilises the wrist but forearm pronation and supination are still possible to certain degrees (Ellanti & Grieve, 2012, p. 72). The wrist orthses aims holds the radius and ulna in position, but it is unknown weather allowing full range of motion of the wrist and DRUJ is beneficial for the healing process. Further research is needed for this method. Acute DRUJ dislocations should be completely immobilised to encourage successful healing, therefore above elbow braces are ideal. Below elbow braces are commonly used subsequently to above elbow immobilisation, once the TFCC has stabilised (Mulford & Axelrod, 2010, p. 158).
Surgical intervention is only recommended for gross instability, displaced fractures, TFCC rupture or avulsions and irreducible dislocations (Thomas & Sreekanth, 2012, p. 501; Ellanti & Grieve, 2012, p. 72; Wassink, Lisowski & Schutte, 2009, p. 141). In unstable DRUJ dislocations the TFCC is unable to heal adequately due to lack of reduction, therefore open reduction is recommended (Mulford & Axelrod, 2010, p. 158; Bain, Pourgiezis & Roth, 2007, p. 477-478). Open reduction with the application of transfixpinning allows fractures and dislocations to be manually reduced and the TFCC to be repaired and reattached. This stimulates the healing process and provides protection (Micucci & Schmidt, 2007, p. 121). After surgery patients are usually prescribed an above elbow orthotic management for four-six weeks, followed by below elbow management for two weeks (Wassink, Lisowski & Schutte, 2009, p. 143; Ellanti & Grieve, 2012, p. 72), this will ensure that the DRUJ is in a stable position, align the radius and ulna and provide protection.

### Treatment plan

The patient in this case study is diagnosis with an isolated dorsal DRUJ dislocation with strains to the primary stabiliser, TFCC. The dislocation is stable and reducible. The treatment plan for this patient is to have closed reduction, under local anaesthesia. Followed by an above elbow brace in elbow flexion, forearm supination for 6 weeks. A follow up session to review the dislocation will be held after 6 weeks and a below elbow brace will be prescribed for a further 4-6 weeks if needed.

### Search strategy

Key terms
* Distal radioulnar joint, DRUJ, wrist, triangular fibrocartilaginous complex, TFCC
* Dislocation, subluxation, injury, stable, tear, isolated, dorsal
* Treat*, mange*, ortho*, brace, splint, cast, template, design
Different combinations of key words were used in various databases. Data bases used include: Medline and CINHAL. From articles read, more literature was found in reference lists. Google scholar or Latrobe library search was used to attain these articles.