The Effect of Release of the Popliteus and Quadriceps Force on Rotation of the Knee

Abstract

The current study was done to determine whether an isolated, partial, or complete injury to the popliteus at the femur increases rotational knee laxity. The other aim was to determine how quadriceps loading affects internal and external rotation. Ten cadaver knee specimens with an intact posterolateral complex were held in a biomechanical testing rig at 0 degrees, 30 degrees, 60 degrees, and 90 degrees flexion. Movement of the tibia relative to the femur was measured while internal and external moments of 3 N-m were applied about the long axis of the tibia. Laxity was assessed for an intact specimen, and with partial and complete detachment of the popliteus femoral insertion. In five of the 10 specimens laxity additionally was assessed with sufficient quadriceps loading to resist 100 N vertical force at the hip. The results showed that partial and total release of the popliteus increased external laxity of the knee by as much as 6.6 degrees (90 degrees flexion) and by as much as 3.5 degrees (90 degrees flexion). Quadriceps loading reduced internal and external knee laxity significantly. Injury of the popliteus at the femoral insertion may be associated with increased rotational laxity of the knee. An increase in quadriceps force may be necessary to control increased external rotation of the tibia.

Gap changes after popliteus-tendon resection in PS-TKA: A cadaveric study in Thai female knees

“…It is described as a primary restraint to external rotation of the knee [4,5]. In addition, the tendon plays a minor role in controlling internal rotation, varus angulation and anterior translation of the knee [5][6][7]. In an arthritic knee, the popliteus tendon may affect the extension gap, the flexion gap or both gaps during total knee arthroplasty (TKA), in which popliteus-tendon release may be necessary in some knee deformities for ligament balancing [6].…”

“…It is described as a primary restraint to external rotation of the knee [4,5]. In addition, the tendon plays a minor role in controlling internal rotation, varus angulation and anterior translation of the knee [5][6][7].…”

“…In a normal knee, the popliteus tendon is reported to have both static and dynamic functional contributions to knee stability [1][2][3][4][5]. It is described as a primary restraint to external rotation of the knee [4,5].…”

Analysis of tibial rotation using magnetic resonance imaging

“…The length of the muscles around the knee, especially quadriceps, hamstrings, IT-band, and popliteus, have previously been found to change the knee kinematics depending on position, possibly affecting the angle of tibial rotation (Kwak et al, 2000;Ferrari et al, 2003). Therefore, we tried to limit these effects as much as possible by using a special apparatus to fix the knee and hip joint flexion angles.…”

Sonographically Guided Popliteus Tendon Sheath Injection

“…1,[5][6][7] Isolated PMTU injuries are uncommon but have been reported as results of minor twisting injuries, tendon instability, impingement against osteophytes or total knee arthroplasty components, calcific tendinopathy, and overuse among runners. [1][2][3][4][8][9][10][11][12][13][14][15][16][17][18] Regardless of etiology, isolated conditions affecting the PMTU may be difficult to recognize and treat because of its relatively deep location and close proximity to adjacent structures. 4 Differential palpation of the popliteus tendon is challenging, and the clinical utility of previously described provocative maneuvers remains indeterminate.…”