## 3 Results
### LCS
#### 3.1.3 Third Generation  
The Journey II XR (Smith and Nephew plc, Watford, United Kingdom) system was designed to overcome ongoing concerns of loosening and improve kinematics. The design consists of an anatomical tibial component that includes a metal tibia try with two independent and uniquely designed concave medial and convex lateral bearings together with a natural 3\({}^{\circ}\) oblique joint line [4]. One kinematic clinical study in 17 knees of 15 patients found the in vivo kinematics of BCR-TKA knees reproduced native knee kinematics to a lower extent compared 20 patients that received unicompartmental knee arthroplasty (UKA) [25]. Larger clinical trials exploring this design are currently underway ([[https://clinicaltrials.gov/ct2/show/NCT03136887](https://clinicaltrials.gov/ct2/show/NCT03136887)]([https://clinicaltrials.gov/ct2/show/NCT03136887](https://clinicaltrials.gov/ct2/show/NCT03136887)), accessed on 14 April 2022). Intraoperative Technique, Design, Balancing and Alignment  
Tibial base plate design has proven to have an important effect on the risk of aseptic tibial loosening, a severe adverse event which has been described in early BCR-TKA designs. For example, linking of two separate baseplates appears to provide increased primary stability in terms of bony fixation, comparable to that of a conventional single tibial baseplate [26]. Computational modeling has been used to identify the most sensitive components of knee joint laxity and suggest a sequence for balancing ligament tensions during knee arthroplasty with a preserved ACP and PCL. Based on the findings of one study, an optimal sequence for adjusting strains of ligament bundles during surgery were identified using a variety of laxity examinations [27]. For example, the anteroposterior laxity has been found to be sensitive to the tension of the ACL ligament in early flexion [27,28]. What is more, a significant correlation was found between extension joint gap change and the \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Study** & **BCR-TKA (n)** & **Comparator (n)** & **Mean Age** & **Design/LOE** & **Follow-Up** & \begin{tabular}{c} **Clinical** \\ **Outcome** \\ \end{tabular} & \begin{tabular}{c} **Complications** \\ **BCR vs. Comparator** \\ \end{tabular} \\ \hline \begin{tabular}{c} [PERSON] \\ [22] \\ [20] \\ [21] \\ [22] \\ [23] \\ [21] \\ [24] \\ [25] \\ [26] \\ [27] \\ [28] \\ [29] \\ \end{tabular} & 25 & CR-TKA 25 & 68/70 & RCT (l) & 2 years & Equal & Fracture (n = 1), stiffness (n = 3) \\ \begin{tabular}{c} [PERSON] \\ [20] \\ [21] \\ [19] \\ \end{tabular} & 303 & CR-TKA 237 & 65/63 & Retrosp (IV) & 1.5 years & Inferior & Revision 5\% vs. 1.3%, RLL (HR, 2.93; \(p<0.001\)) \\ \begin{tabular}{c} [PERSON] \\ [21] \\ [23] \\ [24] \\ [25] \\ [26] \\ [27] \\ [28] \\ [29] \\ \end{tabular} & 195 & PS-TKA 1471 & 65/66 & Retrosp (IV) & 5 years & Inferior & Aseptic loosening 9.7\% vs. 0.1\% \\ \begin{tabular}{c} [PERSON] et al. \\ [23] \\ [24] \\ [16] \\ [19] \\ \end{tabular} & 61 & CR-TKA 61 & 65 & Case-con (IV) & 2 years & Equal & Equal revision (n = 1) no RLL \\ \
\begin{tabular}{c} [PERSON] \\ [16] \\ [19] \\ \end{tabular} & 146 & - & 68 & Retrosp (IV) & 1 years & Improved & Revision 1.4\% \\
\begin{tabular}{c} [PERSON] et al. \\ [19] \\ \end{tabular} & 141 & - & 64 & Retrosp (IV) & 3 years & Improved & Revision 13.5\% (ibial loosening 4\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Clinical outcome studies for Vanguard XP BCR-TKA. change in ACL elongation in 29 patients, highlighting the importance of precise joint line restoration and soft tissue balancing during BCR-TKA [29]. Although concerns exist regarding an increase in patellofemoral compressive forces after BCR-TKA, no significant correlations between intraoperative patellofemoral compressive force and anterior knee pain after anatomical BCR-TKA have been found in 22 patients at short-term follow-up (1.5 years) [30].