# Robotic Systems and Navigation Techniques in Orthopedics: A Historical Review
## 4 Discussions and Future Perspectives
### RS and CANS for Various Orthopedic Surgeries  
From Table 1, it can be found that most of the robotic systems are applied for hip/knee surgeries, some are for spine surgeries, and no specific robotic system is exclusively for elbow/shoulder surgeries. For example, ROSA has robot-assisted systems for the hip, knee, and spine, respectively, but only has a computer-aided system for assisting in planning and navigation for the shoulder. RSs have been abundantly developed and frequently used in hip/knee surgeries but not in elbow/shoulder/foot/ankle surgeries, while the latter seems more favorable for CANSs [77]. The possible reason could be that there are much more cases and higher demand for knee/hip surgery than elbow/shoulder surgery. The knee is the largest hinge joint in the body, while the hip is a large ball-and-socket joint. Both the knee and hip joints take a lot of wear, tear, and stress from daily activities (e.g., walking, running, and jumping) while supporting the body weight in horizontal and vertical directions, and they are more vulnerable to injury and osteoarthritis than the elbow/shoulder or any other joints. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline \multicolumn{1}{c}{**RS**} & \multicolumn{1}{c}{**System**} & \multicolumn{1}{c}{**Usage**} & \multicolumn{1}{c}{**Features**} & \multicolumn{1}{c}{**Pros/Cons (\(\Theta\)/\(\Theta\))**} \\ \hline \multirow{8}{*}{**Category**} & \multirow{4}{*}{**Category**} & \multirow{4}{*}{**Category**} & \(\Theta\) & IBM,1980; & \\  & & & & \(\Theta\) & first patient in 1992; & \\  & & & & \(\Theta\) & pre-CT based; & \\  & & & & & \(\Theta\) & but can stop the robot; \\  & & & & & \(\Theta\) & recovery process is complex \\  & & & & \(\Theta\) & \(\Theta\) & if robot is stopped during surgery. \\  & & & & \(\Theta\) & bone milling; bone preparing. & \\ \cline{2-5}  & & & & & \\ \cline{2-5}  & & & & \(\Theta\) & pre-CT based; & \\  & & & & \(\Theta\) & bone milling and preparation; & \\  & & & & \(\Theta\) & position guiding. & \\ \hline \multirow{8}{*}{**Category**} & \multirow{4}{*}{**Category**} & \multirow{4}{*}{**Category**} & \(\Theta\) & pre-CT-based preop. plan; & \\  & & & & \(\Theta\) & 6 DOF robot; & \\  & & & & \(\Theta\) & haptic feedback; & from deviating from the predefined \\  & & & & \(\Theta\) & bone cutting; & cutting zone. \\ \cline{2-5}  & & & & \(\Theta\) & active-constrained control. & \\ \hline \multirow{8}{*}{**RIO**} & \multirow{4}{*}{**Category**} & \multirow{4}{*}{**Category**} & \(\Theta\) & inherited from ACROOT; & \\  & & & & \(\Theta\) & pre-CT based; & \\  & & & & \(\Theta\) & haptic and audio feedback; & \\  & & & & \(\Theta\) & bone cutting; & \\  & & & & \(\Theta\) & force-controlled tip. & \\ \hline \multirow{8}{*}{**MAKO**} & \multirow{4}{*}{**Category**} & \multirow{4}{*}{**Category**} & \(\Theta\) & inherited from RIO; & \\  & & & & \(\Theta\) & pre-CT based; & \\  & & & & \(\Theta\) & bone cutting; & \\  & & & & \(\Theta\) & emergency auto shutdown; & \\  & & & & \(\Theta\) & \(\Theta\) & \(\Theta\) \\  & & & & \(\Theta\) & \(\Theta\) & \(\Theta\) \\  & & & & \(\Theta\) & \(\Theta\) & \(\Theta\) \\  & & & & \(\Theta\) & \(\Theta\) & \(\Theta\) \\ \hline \multirow{8}{*}{**Category**} & \multirow{4}{*}{**Category**} & \multirow{4}{*}{**Category**} & \(\Theta\) & image-free system; & \\  & & & & \(\Theta\) & \(\Theta\) & \(\Theta\) \\  & & & & \(\Theta\) & \(\Theta\) & \Technically, all joint replacement/arthroplasty surgeries are open surgeries since a significant incision needs to be made in order to expose the bone for bone cutting or implant positioning. It is worth noting that in joint replacement/arthroplasty, minimally invasive approaches/procedures have different definitions, such as shorter incision length, nondissection of quadriceps tendon, noneversion of the patella, or nondislocation of the tibofemoral joint [78].