Radial head - modified posterior approach

(Wrightington)

Indication

Access to the radial head (radial head replacement), allows easy subluxation of radial head.

The lateral approaches to the radial head involve incising the lateral ligament and radial head dislocation is difficult due to the constraints of the interosseous membrane and the annular ligament. See Kocher lateral approach to radial head

Anatomy

See general anatomical considerations about the elbow (link)

The lateral collateral ligament complex is an important constraint to varus and valgus external rotatory laxity.

Avoids posterior interoseous nerve.

Considerations

Not suitable as approach to the radial head  where there is an associated deficiency of the lateral collateral ligament complex. If there is an injury to the lateral ligament as in an acute fracture dislocation, a lateral approach would be better allowing assessment and repair as needed.

Injury to the cutaneous nerves is reduced as few cross the posterior, midline aspect of the elbow.

The modification is the osteotomy, in standard posterior approaches it is important to reconstruct the annular ligament to avoid dislocation of the radial head.

Positioning

Tourniquet on upper arm.

Lateral position with the limb placed over an arm rest.

(Alternatively see elbow positioning)

Landmarks are the olecranon, the lateral epicondyle and the head of the radius.

Skin Incision

Curvilinear incision from the lateral epicondyle to a point 3 to 4 cm distal to the olecranon. This incision is then extended proximally for a further 2 cm to 3 cm towards the midline.
This incision has the advantage of being a smaller wound, centred over the head of the radius.
Alternatively use posterior midline skin incision elevating skin flap, this also allows access to the medial side of the joint.

Superficial dissection

Raise full thickness flaps exposing the deep fascia over anconeus muscle. Incise this fascia leaving a 1 cm flap attached to the ulna.

Dissect anconeus from the ulna, make an arthrotomy exposing the head of the radius, the annular ligament inserting into the supinator tuberosity and the interosseous membrane. The supinator tuberosity can be seen and palpated.
Osteotomise the supinator tuberosity using an osteotome; make the osteotomy flush with the shaft of the ulna.

(Critical step make ostetomy flush with ulna don't make fragment too small)

The preferred method of fixation is bone anchors, screws may be used but risk fracturing the small bone fragment. If using screws pre drill the holes prior to making the osteotmy.

Osteotomise at least 5mm of bone with the attached annular ligament still attached.

Dislocate the head if needed.

Closure

Re attach the bone fragment and annular ligament with:

• Bone anchors and suture fixation (mini Mitek G-2) - Stanley preffered method

• Mini fragment screws - risks fracture of fragment

• Trans osseous sutures/ wire

Repair the anconeus muscle to the ulna.
 

Post operatively

Depends a little on indication.

For simple radial head replacement - early ROM day 1 or day 2.

References

Stanley JK, Penn DS, Wasseem M.; Exposure of the head of the radius using the Wrightington approach.; J Bone Joint Surg Br. 2006 Sep;88(9):1178-82.
 

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Page created by: Lee Van Rensburg

Last updated 11/09/2015