Revision Total Elbow Arthroplasty

Why elbows fail. A primary total elbow arthroplasty fails in one of several ways, and the revision has to address the one in front of it. The elbow's small bones, thin cortices and high lever-arm loads make all of them common.

• Aseptic loosening - the commonest late cause of failure and indication for revision
• Polyethylene bushing wear in linked (semi-constrained) implants, which generates particulate debris, osteolysis and progressive loosening
• Periprosthetic fracture
• Deep infection
• Instability or mechanical component failure, such as a fractured stem

The warning signs. Even primary linked TEA has a high complication rate with a comparatively low revision rate. The concerning long-term signals are increasing radiolucent lines around the ulnar component and bushing wear.

Why revision is harder. The revision is performed in bone and soft tissues that are already compromised, so it carries a higher complication burden still, including periprosthetic fracture, ulnar neuropathy, wound-healing problems, re-loosening, infection and re-revision. Outcomes are modest and the risks substantial, which is why selection and planning matter.

Counselling. Tell the patient realistically what to expect: modest function, and a revision that is complication-heavy with a real re-revision rate. The construct is protected by a permanent lifting restriction of 2-5 kg, the same lifelong limit that applies after a primary TEA.

How Bone Loss Is Actually Described at the Elbow

Unlike the hip, the elbow has no single universally adopted bone-loss classification in the way Paprosky is used for the femur and acetabulum. The deficiency therefore has to be described rather than graded, and four questions do the describing. Answer them from a CT with metal-artefact reduction and the reconstruction largely chooses itself.

Periprosthetic Fracture: the Mayo Classification

Periprosthetic fracture is both a reason a primary arthroplasty comes to revision and the commonest single complication of the revision itself, so it needs its own framework. The classification in general use comes from O'Driscoll and Morrey's Mayo experience of more than 1,000 total elbow arthroplasties. It is built on where the fracture lies relative to the stem, and is applied the same way on the humeral and the ulnar side.

The Reconstruction Ladder

The reconstruction climbs with the bone loss, from the least invasive revision to a salvage.

Bushing exchange. For isolated polyethylene wear with well-fixed stems, exchange the bushings and treat any osteolysis. It is the least invasive revision.

Longer stems with impaction grafting. A loose stem with contained, cavitary bone loss is re-cemented with longer revision stems, using impaction (cancellous) grafting to restore the canal.

Allograft-prosthetic composite (APC). Massive segmental bone loss is reconstructed with an APC as a salvage, typically a semi-constrained (Coonrad-Morrey-type) prosthesis cemented into a structural allograft. Midterm series report satisfactory function with allograft incorporation in most, but a high complication rate, including periprosthetic fracture, ulnar neuropathy and wound problems. It is reserved for severe deficiency and counselled accordingly.

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The Infected TEA

DAIR works far less well at the elbow than "acute infection, retain the implant" suggests. In a Mayo cohort of 26 elbows with periprosthetic joint infection managed by debridement, antibiotics and implant retention, the procedure failed in 17: a failure rate of 65% at two years (95% CI 41.3-79.6%), with a median time to failure of only 43 days. The authors conclude that a patient offered DAIR must be told the chance of success is approximately 35%. That number makes the consent honest, and it is why the staged route is the default here in a way it is not at the hip or knee.

When not to retain. DAIR failed in every case with a sinus tract and in every case that was culture-negative, so either finding should be read as a contraindication to retention rather than a reason for caution. A shorter symptom duration and a monomicrobial infection characterised the patients who did well, though with those numbers the associations did not reach statistical significance.

The staged protocol. The first stage removes all components and cement, with radical debridement, deep samples from several sites before antibiotics, and an antibiotic-loaded cement spacer. Organism-directed intravenous therapy follows, guided by microbiology and infectious-disease input, and re-implantation is delayed until the infection is controlled clinically and biochemically.

The soft-tissue envelope. At the elbow it is thin and posterior, with little subcutaneous cover over the implant and often several previous incisions, and wound dehiscence is a prominent complication in the published revision series. Use the previous incision where possible, avoid parallel incisions that devascularise the skin bridge, handle the edges minimally, and involve plastic surgery early where cover is doubtful.

Resection arthroplasty. A legitimate endpoint, not simply a failure. Where re-implantation is not feasible - uncontrolled infection, unreconstructable bone, or a patient unfit for further surgery - resection gives reasonable pain relief at the cost of a flail, unstable elbow. Describe that trade to the patient in those terms rather than as a fallback of last resort.

Revise to a Linked Implant

The revision elbow is, almost by definition, the elbow with deficient bone, incompetent collateral ligaments, or both. That is precisely what an unlinked (resurfacing) design cannot tolerate, because it depends on the soft tissues for stability, so a failed unlinked implant and a failed linked implant are in practice both revised to a linked (semi-constrained) device.

The sloppy hinge. The linkage permits about 7-10 degrees of varus-valgus and rotational laxity. This lets load be shared with the surrounding soft tissues rather than concentrated at the bone-cement interface, the very interface that has already failed once.

Getting the Old Cement Out

Cement extraction, not implantation, is the technical crux of the revision. It is the step that generates most of the bone loss and most of the periprosthetic fractures. The canals are narrow, curved and thin-walled, and the ulna especially offers very little margin between a cement lump and the cortex; perforation and iatrogenic fracture are made here, not at the moment of implantation.

• Take deep samples first if there is the slightest question of infection, and treat the case as potentially infected until they are negative
• Work under direct vision as far as possible, with long, fine osteotomes and cement splitters down the canal rather than blind reaming, taking the cement out in fragments from the inside rather than levering against the endosteum
• Ultrasonic cement removal tools soften deep cement and withdraw it along the canal with less cortical damage than mechanical instruments, and are the standard aid where they are available
• A controlled cortical window or extended osteotomy is preferable to an uncontrolled perforation when distal cement cannot be reached: plan it, place it where it can be plated or strut-grafted, and repair it

Why it is at risk. The ulnar nerve runs in the cubital tunnel behind the medial epicondyle, at the medial margin of the surgical field. In a revision it is encased in scar from the prior surgery and may already have been transposed, so it is distorted, tethered and hard to find, and at high risk from exposure, retraction and traction, and thermal injury. The full anatomy is in Ulnar Nerve Anatomy and Cubital Tunnel Syndrome.

Before surgery. Document any pre-existing ulnar neuropathy, so that a post-operative deficit is not wrongly attributed to the revision.

At operation. Formally expose the nerve in healthy tissue proximal and distal to the scarred zone, follow it into the field and handle it gently. Then decide between in-situ protection and anterior transposition; the nerve is often transposed if it was previously transposed or is tethered.

Counsel for it. Ulnar neuropathy is among the commonest complications of revision elbow surgery. It is often transient (neurapraxic) and occasionally permanent.

The approach. A TEA and its revision must both deal with the triceps insertion on the olecranon, through one of these approaches:

• Triceps-reflecting, for example Bryan-Morrey, which reflects the triceps medial-to-lateral in continuity with the forearm fascia and periosteum
• Triceps-splitting
• Triceps-on (paratriceps, triceps-sparing), which leaves the insertion intact

If the triceps is taken down it must be securely reattached transosseously. Choose the least-disruptive approach that gives adequate access, and protect and securely repair the extensor mechanism: it is as important to the outcome as the implant.

Triceps insufficiency. A recognised complication of revision. Repeated approaches, and the poor tissue of rheumatoid or multiply-operated elbows, can leave the triceps detached or attenuated, with weak or absent active extension and difficulty pushing up from a chair. It is managed by direct repair or by reconstruction, for example anconeus rotation or Achilles tendon allograft; the rupture itself is covered in Triceps Tendon Rupture.