Bone Quality & Total Ankle Arthroplasty (TAA)

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A core principle in major joint arthroplasty is achieving immediate and stable fixation of the implant. This principle also applies to the tibial fixation in total ankle arthroplasty, but it is challenged by the relatively poor bone quality in the distal tibia.

 

Implant choice may reduce odds of total ankle replacement (TAR) failure

 

In their study published in JBJS this spring, Henry et al. reviewed 731 patients who underwent TAR, focusing on the revision of the tibial component as the primary outcome. They concluded that hindfoot arthrodesis is associated with 2.7 times greater risk of failure. However, the study also revealed that more extensive tibial fixation lowered the odds of failure by 95%.

 

Pegs, posts, and stems

 

In TAR, the choices for tibial fixation include: 

 

• Pegs: fixed-length devices less than 1 cm long, impacted into metaphyseal bone

• Posts: also fixed-length devices, but are 3 cm long or less and similarly impacted into the metaphyseal bone

• Stems: modular devices that extend from the metaphysis into the diaphysis and are 3 cm or longer 

 

Enhanced tibial bone fixation options are particularly beneficial for patients with poor tibial bone quality or those who have undergone hindfoot arthrodesis. 

 

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Pain After Ankle Arthroplasty (AA): Is Conversion to Total Ankle Arthrodesis (TAA) Truly Viable?

by Vince Vacketta, DPM

 

Debilitating ankle osteoarthritis (OA) affects a broad demographic of patients. Considerations for procedure selection between AA and TAA are numerous, though patient age consistently discourages for the use of TAA particularly in young patients with post-traumatic OA. These patients often undergo AA, but later face challenges with adjacent joint arthrosis. This situation presents an opportunity to convert AA to TAA.

 

But are these outcomes successful? 

 

According to a systematic review titled “Takedown of Ankle Arthrodesis and Conversion to Total Ankle Arthroplasty,” the answer is yes. Furthermore, the study, published last week, demonstrated that the improvements in AOFAS scores and visual analog scale scores for takedown TAA are comparable to those for primary TAA. Included within this review were studies with and without a native fibula, as well as those using a fibular prosthesis. As expected, TAA without a native fibula had higher rates of complications, primarily valgus collapse. In contrast, cases using a fibular prosthesis showed improved outcomes. 

 

The takeaway

 

AA takedown to TAA has shown better outcomes than we may have originally expected. Results are more favorable when a native fibula is preserved, so it’s advisable to avoid resecting the fibula during primary AA. 

 

 

What's New? Osteochondral Lesions of the Talus (OLT)

 

Using the general term osteochondral lesions of the talus is a disservice to patients and physicians alike. Individual characteristics like bone marrow edema (BME), location, depth, and mechanism, all impact symptoms, prognosis, and treatment. Teasing out prognostic variables can help set more accurate guide expectations.

 

Edema as a prognostic variable

 

In their 2024 study published this month, Li et al. concluded that the severity of the preoperative BME negatively affected short-term clinical outcomes following arthroscopic bone marrow stimulation (BMS) for OLTs. This finding aligns with a previous study by Cuttica et al., which examined the correlation between MRI detected edema and clinical outcomes after microfracture treatment of OLT. The authors developed an MRI grading system for postoperative BME and concluded that presence of edema on MRI after drilling OLTs was an objective measure of outcome, with patients exhibiting greater edema intensity experiencing inferior clinical outcomes.

 

Hot off the press: outcomes with marrow stimulation

 

Last month, Rikken et al. published a study on the long-term outcomes of BMS for OLT. With a minimum follow-up of 10 years, the survival rate of arthroscopic BMS for OLT was 82%, where survival was defined as the absence of repeat surgery. At 15 and 20 years of follow-up, the survival rate appeared to remain stable.