Posterior Elbow approach

In contrast techniques in which the triceps is split or reflected can be used for fixation of fractures and for total elbow arthroplasty, but they give a less satisfactory exposure of the distal humerus than can be achieved by olecranon osteotomy.

I prefer this approach for distal humeral fractures for several reasons:

You can start with a triceps split (75% lateral, 25 % medial), if you require more exposure you can proceed to reflection of triceps off the olecranon.

The distal humerus and elbow are exposed entirely, allowing fixation of fractures or if you find it impossible to reconstruct the distal humeral articular surface you can then still safely proceed to an elbow arthroplasty as the olecranon remains intact.

The dissection is carried out deep to the ulnar nerve which is safely mobilised with its deep soft tissues and
blood supply, reducing the risk of postoperative ulnar neuritis.

Anatomy

Considerations

Consider Tourniquet high on arm

Positioning

Supine with arm over L bar

Lateral with arm over L bar so forearm hanging freely

Skin Incision

Posterior incision beginning 8 cm proximal to the olecranon, extending distally, skirting the ulnar aspect of the tip of the olecranon, and continuing for a further 8 cm along the subcutaneous border of the ulna.

Consider skirting radially and lifting skin flap (takes scar away from area under pressure when resting arm on table etc.)

Superficial dissection

Identify and decompress the ulnar nerve superficially.

Deep dissection

Identify the medial border of the belly of the triceps.

Incise the triceps tendon so that 75% of the muscle lies laterally and 25% medially.

Deepen the incision through triceps to the tip of the olecranon and continue distally splitting the superficial fascia of the forearm for about 6 or 7 cm.

Reflect the medial triceps, with the superficial fascia of the forearm and the periosteum over the medial aspect of the olecranon, medially as a single unit.

Take care to maintain the continuity of the extensor envelope where the triceps blends into the fascia of the
forearm.

Slightly extend the elbow at this stage to relieve the tension, continue the dissection subperiosteally, deep to the ulnar nerve and over the tip of the medial epicondyle.

The dissection is extended laterally according to the needs of the procedure being undertaken.

The lateral 75% of triceps is then reflected from the tip of the olecranon in continuity with the forearm fascia as a strap.

The anconeus is then reflected subperiosteally from the proximal ulna to expose the radial head. The posterior capsule is reflected with the triceps, exposing the entire joint.

Exposure extension

Closure

Drill holes in the olecranon to allow reattachment of triceps with sutures through drill holes in the olecranon.

Repair the triceps tendon, allowing the ulnar nerve to fall back into its anatomical position.

Post operatively

Modifications

Campbell described the posterior split of the triceps muscle in the midline, and continued the exposure distally in the forearm by elevating the anconeus and flexor carpi ulnaris.

Steiger et al modified this approach by raising osteoperiosteal flaps from the olecranon.

Van Gorder created an inverted ‘V’-shaped flap of the triceps mechanism to expose the distal humerus.

In all of these approaches there is considerable mobilisation of the ulnar nerve.

Boyd described a technique reflecting the entire triceps mechanism from the lateral to the medial side.

Bryan and Morrey used a similar technique but with reflection of the triceps from medial to lateral, beginning at
the medial intermuscular septum. The triceps was reflected in continuity with the fascia of the forearm and the periosteum.

The advantage of this approach (Shahane and Stanley) is that the muscle is neither split nor violated and continuity of the extensor mechanism is maintained with the forearm fascio-ulnarperiosteal complex.
This technique allows the raising of the major part of the triceps in continuity.

Protection of the ulnar nerve by the medial part of triceps reduces the possibility of damage to its blood supply and at the end of the operation it can glide and slide in its original position.

References

S. A. Shahane and D. Stanley; A posterior approach to the elbow joint; J Bone Joint Surg Br, Nov 1999; 81-B: 1020 - 1022

Personal observations