A Solution to Tough Revision TKA Approaches, and Its Risks

What’s the Claim?

A large case series of revision TKAs performed using an extended tibial tubercle osteotomy for exposure identified not only the benefits of the approach, but also its risks, namely:

• 15% had severe complications (mostly displaced osteotomies and nonunions)
• 5% underwent major revision procedures

Outcomes scores, as one would expect, were good, but not great. That’s revision TKA in a nutshell. But the honest reporting about the shortcomings of this extensile exposure is worth your attention, as is the authors’ cautionary message about how to do these osteotomies right:

To avoid tibial tubercle fracture or nonunion, a rigorous surgical technique is crucial, with a sufficient length and thickness of the tibial tubercle, a smooth end, a proximal step, a final good bone contact, and a strong fixation; the rehabilitation protocol must be standardized.

How’s It Stack Up?

That’s a big difference from the original description of the technique, which described it as “safe and reliable” and said “early rehabilitation and weightbearing can be done with a low potential for complications.” In fairness, when that author reported again, five years later, he did so with greater modesty: “[the osteotomy] weakens the upper tibia, and predisposes it to fracture in cases of unusually high stress . . . [these fractures] resulted in significant clinical consequences, and these cases illustrate the importance of caution after using this approach . . .”

What’s Our Take?

That observation — and the complications the authors report in the series here — comport well with my own revision TKA experience. If anything, we have to surmise that the percentages the authors report were best-case scenario estimates, since they do not mention loss to follow-up, and I’ve never seen a case series of 135 patients in which none was lost to follow-up before two years. It may therefore be fairer to say that at least 15% had severe complications and at least 5% underwent major revisions. Some may have had complications treated and revisions performed elsewhere.

Nonetheless, we sometimes need greater tibial exposure distally during revision TKA, and there’s no question that an extended tibial tubercle osteotomy beats an extensor mechanism avulsion every day of the week. (Although the title of this article doesn’t use the word “extended,” this is indeed an extended osteotomy; the authors’ technique calls for a “bone block size aimed at least 60 mm in length, 10 mm thick, and 20 mm in width”). My suggestion is do this osteotomy if you need to, but I would not go to it quite as quickly as I would, say, an extended trochanteric osteotomy during a revision THA, where the complications are much less frequent and way less severe.

Two other things to consider during tough knee revisions:

• Patience. Don’t hurry these exposures. Small sequential steps — removing the fat pad and peripatellar/lateral gutter scar tissue, getting the components out before finishing the exposure (if you can do so safely) — can make a big difference.
• Less may be enough. Although many believe the exposure isn’t complete until the patella can be everted, I find that subluxating it laterally and protecting it with a retractor provides similar exposure with less risk.

Source

Cance N, Batailler C, Shatrov J, Canetti R, Servien E, Lustig S. Contemporary Outcomes of Tibial Tubercle Osteotomy for Revision Total Knee Arthroplasty. Bone Joint J. 2023;105-B:1078-1085.