Custom instrumentation for ankle replacements

Total ankle replacement surgery has advanced significantly with the introduction of custom instrumentation, a technology that transforms how surgeons plan and execute joint reconstructions. Mr Shelain Patel, consultant foot and ankle orthopaedic surgeon at RNOH Stanmore and RNOH Bolsover Street Outpatient Assessment Centre, utilises these patient-specific guiding systems to achieve unparalleled accuracy when treating severe, end-stage ankle arthritis.

Traditional ankle replacements rely on standard, generic jigs to guide surgical cuts, which can be challenging given the complex anatomy of the foot. This article explores how custom instrumentation works, its clinical benefits, and how it refines the surgical journey for patients.

What is custom instrumentation in ankle surgery?

Custom instrumentation, also known as patient-specific instrumentation (PSI), is the use of tailor-made cutting blocks created specifically for an individual patient's anatomical structure. It’s a rapidly growing innovation within orthopaedic surgery, designed to overcome the subtle variations in bone shape and joint alignment that differ from person to person.

The process begins weeks before the operation, using high-resolution computerised tomography (CT) scans of the patient's lower limb. Advanced software converts these images into a three-dimensional digital model of the arthritic ankle.

The orthopaedic surgeon then uses this virtual model to plan the exact size, position, and orientation of the implant. Once finalised, 3D-printing technology is used to manufacture custom nylon guides that fit perfectly onto the patient's bones during surgery.

What are the primary benefits for the patient?

The integration of patient-specific guides provides substantial advantages over conventional surgical methods, particularly regarding implant longevity and joint function. Because the guides are pre-planned to fit the unique contours of the bone, the surgeon can achieve highly predictable, millimetre-accurate bone cuts.

• Optimal alignment: Precision placement ensures the mechanical axis of the leg is perfectly restored, which reduces uneven wear on the new joint and lowers the risk of long-term implant failure.
• Bone preservation: Custom guides allow the surgeon to trim away the absolute minimum amount of bone necessary, preserving the healthy, dense bone needed to support the prosthetic components.
• Reduced operative time: Eliminating the need for manual intraoperative measurements shortens the time the patient spends under anaesthesia, which directly lowers the risk of surgical site infections.
• Fewer surgical instruments: The streamlined workflow requires fewer trays of generic tools in the operating theatre, minimising tissue disruption and simplifying the procedure.
• An evaluation helps determine if a patient’s arthritis and structural alignment are well-suited to this custom-engineered approach.

What can patients expect during recovery?

While custom instrumentation maximises surgical precision, the biological healing timeline of the bone and soft tissues follows a structured recovery pathway. Patients typically remain in a protective cast or boot and use crutches to stay completely non-weight-bearing for the first two weeks to allow the surgical incision to heal safely.

Once the initial swelling has subsided, patients transition into a removable boot and begin a dedicated physical rehabilitation programme. Because custom alignment reduces abnormal strain on the surrounding ligaments and tendons, early movement is often smoother and more comfortable.

Most individuals gradually return to full weight-bearing by week six, with normal walking and light daily activities resuming by month three. Clinical data indicates that over 85 per cent of patients experience profound pain relief and a substantial improvement in their walking gait, allowing them to return to a more active, independent lifestyle within six to twelve months.

References

• British Orthopaedic Foot & Ankle Society (BOFAS). (2025). Patient-Specific Instrumentation in Total Ankle Replacement.
• Royal National Orthopaedic Hospital (RNOH). (2024). Advanced Surgical Technologies in Foot and Ankle Reconstruction.
• National Institute for Health and Care Excellence (NICE). (2023). Total ankle replacement using patient-specific guides for end-stage arthritis.
• The Bone & Joint Journal. (2022). A comparative study of patient-reported outcomes and alignment accuracy in standard versus custom-guided total ankle arthroplasty.