Promising Clinical Outcomes Using Rotational Achilles Autograft for Knee Arthroplasty Terrible Triad

Area of Science:

• Orthopedic Surgery
• Reconstructive Surgery
• Limb Salvage Procedures

Background:

• The knee arthroplasty terrible triad (TT) is a complex limb-threatening condition characterized by periprosthetic joint infection (PJI), extensor mechanism insufficiency, and soft-tissue defects.
• TT historically leads to poor functional outcomes, with high rates of amputation or fusion.
• The rotational gastrocnemius-Achilles flap (GARF) is explored for its potential to provide native soft-tissue coverage and muscular support for knee extension.

Purpose of the Study:

• To evaluate the efficacy of the gastrocnemius-Achilles rotational flap (GARF) combined with two-stage revision for treating the knee arthroplasty terrible triad (TT).
• To assess if GARF application improves functional and limb-salvage outcomes compared to historical data.

Main Methods:

• A retrospective review of 19 patients with TT who underwent GARF between January 2020 and December 2024.
• Primary endpoint: composite functional success (retained arthroplasty, no infection, ≥90° ROM, ≤15° extensor lag, independent ambulation at 1 year).
• Secondary outcomes: amputation rate, GARF complications, and patient-reported outcomes (KOOS JR).

Main Results:

• Composite functional success was achieved in 8 of 19 patients.
• Two patients underwent knee fusion, and three required above-knee amputation; 13 patients were independently ambulatory with assistive devices.
• Knee injury and Osteoarthritis Outcome Score Joint Replacement (KOOS JR) scores improved significantly, and GARF-related complications were minimal.

Conclusions:

• The gastrocnemius-Achilles rotational flap (GARF) is a safe and promising treatment for the knee arthroplasty terrible triad (TT).
• GARF yields superior early composite functional outcomes and improved limb salvage rates compared to traditional reconstruction and coverage techniques.
• Extended follow-up is necessary to confirm sustained treatment success.