Total knee arthroplasty (TKA) has evolved over the past 40 years to a point where it now is a routine treatment with fairly predictable outcomes. However, TKA is an end-stage treatment which frequently is used when only one or two compartments in the knee are damaged. Ideally, treatments for earlier stage and isolated disease would be available to provide the same high level of outcome predictability, but provide for isolated treatment of the affected compartments, greater levels of postoperative physical activity and the shorter convalescence demanded by younger, more active, and often employed patients. One approach to a compartment-by-compartment treatment regime is the utilization of discrete condylar unicompartmental prostheses and a patellofemoral prosthesis in any combination. This approach has been practiced in some European clinics for decades with good reported outcomes. However, it remains a major surgical challenge to optimally place multiple discrete arthroplasty components using conventional tools and small incisions. This lecture will present a detailed overview of a unified approach to minimally invasive, modular knee arthroplasty using haptic robotic instrumentation and implants designed specifically for robotic installation in a customized modular treatment regime.

Haptic robotics provide a ‘virtual cutting guide’ capability permitting precise sculpturing of bone surfaces using near-zero-visibility minimally invasive incisions. The use of a single-multifunctional tool eliminates many of the instrument trays commonly needed for these procedures. The surgeon has complete control in manipulating the bone cutting tool within the desired bone-removal area, but the haptic robotics prohibit the cutting tool from removing bone outside the planned bone removal volume. Precise bone sculpturing has the potential to minimize bone removal and optimize the alignment and fixation of the prosthetic components.

Haptic robotic cutting tools obviously can be used with off-the-shelf prosthetic components, but this approach would fail to fully take advantage of the precision surfaces that can be achieved using robot assisted bone sculpting. Instead, a purpose built system of modular knee components can be defined that work in any combination (medial or lateral unicompartmental, bi-unicondylar, medial or lateral plus patellofemoral, or tricompartmental), require minimum bone removal, can be placed through very small incisions, give great flexibility to customize implant placement to fit the patient’s anatomy, and take advantage of the types of fixation features which easily are created with a robotically controlled bone cutting device.

The current treatment implementation and implant design will be presented. Clinical results for unicompartmental procedures and in vitro results for multiple-compartment procedures will be presented and discussed.