Patellar Lateral

The patellofemoral contact area is smaller than the tibiofemoral contact area (Table 49.10). As the knee joint moves from extension to flexion, a band of contact moves upward over the patellar surface (Figure 49.10). As knee flexion increases, not only does the contact area move superiorly, but it also becomes larger. At 90° of knee flexion, the contact area has reached the upper level of the patella. As the knee continues to flex, the contact area is divided into separate medial and lateral zones. 

The PTB socket design, initially developed at the University of California at Berkeley in the late 1950s, accommodates the nonuniform load-bearing tolerances of the residual limb. The basic concept of the PTB socket is to distribute the load over areas of the residual limb in proportion to their ability to tolerate load. Therefore, the majority of the load is to be borne on the patellar tendon (hence the name), medial and lateral flares of the tibia, and the popliteal area. The PTB socket precompresses the residual limb tissues in these load areas so that forces are transmitted comfortably and movement of the socket relative to the skeleton is minimized.The socket is thus a replica of the residual... 

Patellar tendons from donors ranging in age from 17 to 54 years were tested at either 10% or 100% elongation per second, to examine effects of donor and strain rate on tensile properties. A pressure micrometer was used to measure cross-sectional area and the initial length of the tendon (from patellar to tibial insertion site) was used for strain measurements. Specimens were kept moist with a saline spray during tensile testing. Medial, lateral, and sometimes central portions were taken from 25 donors regional differences across the tendon were not considered. 

Fig. 15.1 Locations of the three portals and landmarks on the right knee joint for ACL reconstruction using the far anteromedial portal technique. AL anterolateral portal, AM anteromedial portal, FAM far anteromedial portal, FT patellar tendon, IFF inferior pole of the patella, UL lateral joint line, MJL medial joint line, 7T tibial tuberosity...

We generally use a three-portal technique using the anterolateral portal, central anteromedial portal (CAM), and the far anteromedial portal (FAM) [20]. The anterolateral portal is positioned above the lateral meniscus, adjacent to the lateral border of the patellar tendon, and serves as a viewing portal for the tibial insertion. 

The graft is harvested through 5-6-cm longitudinal skin incision just medial to the patellar tendon from the central portion of the medial half of the patellar tendon. As the central portion of the tendon is shorter than the lateral or medial side, the graft has longer and shorter side in its tendinous portion. The former is assigned to anteromedial portion of the graft, and the shorter one is to the posterolateral portion (Fig. 30.3). 

Fig. 39.2 Preoperative three-dimensional (3D) computed tomography (CT) images of the knee showing a completely malpositioned femoral tunnel (black arrow), (a) The broken line shows a lateral intercondylar ridge which was not destroyed by the previous tunnel, (b) The black ellipse shows a new anatomical rectangular tunnel location in a revision procedure with bone-patellar tendon-bone graft without communication with the previous tuimel. (c) Two anatomical tunnels in a revision procedure using hamstring tendon grafts without communication with the previous tunnel are marked...

Boston, MA, NAS participants (N = 448 men), 6% with diabetes, 26% hypertensive PbB, tibial Pb, patellar Pb examined at baseline Predictive changes, serum creatinine at baseline and 6 years later Serum creatinine and PbB decreased over the period interactions with diabetes and hypertension on creatinine changes Tsaih et al. (2004)... 

The femoropatellar joint is a sellar joint the articulating surface of the patella is adapted to the patellar surface of the femur. This femoral articulation involves the anterior surface of both condyles. An oblique groove divides it into a large lateral and smaller medial area. The quadriceps muscles, the quadriceps tendon, and the patellar tendon maintain the joint s stability. Its major motions are vertical up-and-down movement on the femur, and movement in a sagittal plane with respect to the tibia. This allows a pulley function during flexion and extension of the knee. 

FIG. 98-5 Location of the tender points around the knee. PAT, patellar LM, lateral meniscus LH, lateral hamstring MM, medial meniscus MH, medial hamstring EX, gastrocnemius AC, anterior cruciate PC, posterior cruciate. 

Conclusion Ablation of the VM did not cause a lateral shift in patellar tracking, or an increase in lateral pressure distribution in the patellofemoral joint, as has been suggested clinically and anecdotally. It is not known whether this result would also hold for the human knee, but it does raise the question why clinical treatments of patellofemoral joint pain are concerned primarily with strengthening VM, despite a lack of direct evidence that VM strengthening will alter patellar tracking and/or patellofemoral contact pressure distributions. 

The femoral unit clamping block or jig was produced which it can flex at certain angle. The jig produced has the same lateral profile as the femoral unit. The femoral s jig has 5 holes which is to lock the femoral s jig at 5 flexion angle of knee flexion. At the back of the femoral unit, there are 2 pins which allows the femoral s jig to clamp the femoral unit. The femoral s jig is clamped by compression test machine (Universal Testing Machine, model LS-28101-UTM) [1]. The patellar s jig with a diameter central holes 14.45mm and depth of 5.5mm was clamp to the UTM machine. Then the articulate patellar seated into the patellar s jighole underneath the femoral unit and allowed to move freely in the hole to centralise the unit about the femoral surface. The two sheets of FUJI Prescale low stress film... 

Secondly, the patellar movement during flexion in both lateral and rotary directions for prosthesis fixed to the bone of the patella. This can cause larger compression forces on the periphery of the polyethylene and increased tension of the lateral tissues around the patella[l,4]... 

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