Prevention of extension lag using a sling attachment for Ligamentotaxor ® devices in complex proximal interphalangeal joint injuries.

BACKGROUND

Fracture subluxations at the proximal interphalangeal joint can be difficult to treat and variable in their outcome. A number of devices have been described that provide dynamic external fixation, allowing rehabilitation during the period of stabilisation. The Ligamentotaxor® device (Arex, Palaiseau, France) has been in use at our institution since 2008 and good results have been achieved. It was recognised that a small number of patients develop an extension lag at the distal interphalangeal joint while a Ligamentotaxor® device is in situ during treatment of fractures in the proximity of the proximal interphalangeal joint.

TECHNIQUE

The sling attachment shown was devised in our unit. It is quick and simple to apply to the frame. It is manufactured from Velcro® and Orfit thermoplastic (Wijnegem, Belgium), and is easy to remove for exercise (if appropriate). It does not affect the normal functioning of the frame.

Warmed Orfit thermoplastic is bonded onto ‘loop’ Velcro® approximately 2cm from one end.

The Velcro® strip is secured around one of the distal portions of the spring at the level of the distal phalanx (Fig 1).

Figure 1

Velcro® is bonded to Orfit thermoplastic and attached to Ligamentotaxor® device

The adhesive backed ‘hook’ Velcro® is adhered to the thermoplastic, passed under the distal phalanx and wrapped around the spring on the other side of the Ligamentotaxor® device, fastening to the hook Velcro® underneath, thereby supporting the distal phalanx (Fig 2).

Figure 2

Sling is passed under distal phalanx, looped around device and fastened

DISCUSSION

Prompt recognition of extensor lag and treatment using this frame modification arrests progression of the problem and facilitates its resolution. We recommend use of the Ligamentotaxor® sling in all cases complicated by extension lag.