Stress radiography to measure posterior cruciate ligament insufficiency: a comparison of five different techniques

Abstract

Stress radiography presents the golden standard to quantify posterior laxity in posterior cruciate ligament (PCL) insufficiency. Several different techniques are currently available, but comparative data are insufficient. Different stress radiographic techniques result in different values for posterior laxity. Comparative controlled clinical study was designed. Prior to PCL reconstruction 30 patients underwent a series of stress radiographs: Telos device, hamstring contraction, kneeling view, gravity view, and an axial view. Posterior displacement, side-to-side difference (SSD), condyle rotation, required time, and pain were measured. Posterior displacement was: Telos 12.7 +/- 3 mm (SSD 10.6 +/- 3.1 mm), hamstring contraction 11.2 +/- 3.2 mm (SSD 8.5 +/- 3.4 mm), kneeling 14.4 +/- 3.8 mm (SSD 10.2 +/- 3.5 mm), gravity view 10.5 +/- 2.8 mm (SSD 9.1 +/- 2.4 mm), and axial view 19.4 +/- 6.9 mm (SSD 8.5 +/- 4.1 mm). In comparison to Telos the hamstring contraction, gravity, and the axial view underestimated the SSD by approximately 2 mm. Telos and kneeling caused significantly more pain than all other techniques (P < 0.001). The axial view was fastest (115 s, P < 0.001) and Telos longest (305 s, P < 0.001), respectively. Telos indicated the lowest rotational error with a significant difference between kneeling and gravity (P < 0.003). In contrast to Telos as the golden standard, hamstring contraction, gravity, and axial view underestimated the SSD. Kneeling and Telos are comparable with respect to SSD and pain. Although kneeling indicates a greater rotational error than Telos, it seems to be a reliable alternative for quantifying posterior tibial displacement in a more simple and fast way.

Stress Radiography for the Diagnosis of Knee Ligament Injuries: A Systematic Review

“…The stress radiography techniques and devices described in the literature varied by the plane of stress and therefore the ligament(s) isolated ( 47], manual force [6,12,13,32,40,44,46], hydraulic force [17][18][19], S-type load cell [25,26], a constant-tension spring [48], and the dynamic stress test using active muscle contraction [1,7,21]. A total of 16 unique stress techniques were described across all studies included in this review (Table 3).…”

“…Its applications include diagnosing acute and chronic injuries [1,21,30,32], comparing instability preoperatively and postoperatively [20,24,39,55], and monitoring stability in nonoperatively treated patients [17]. A variety of stress techniques have been described that assess ligament stability using an anteriorly, posteriorly, varus-, or valgus-directed force to the knee [10,14,17,28,29,37,40,41,43,45].…”

Arthroscopic Treatment of Acute Tibial Avulsion Fracture of the Posterior Cruciate Ligament Using the TightRope Fixation Device

“…Side-to-side differences in anteroposterior translation are graded with a Telos Stress Device (Telos, Marburg, Germany) beginning at 3 months after surgery. 13 Of note, because of the risk of displacement, passive stress radiographs are not obtained before surgery (Fig 7).…”

Role of High Tibial Osteotomy in Chronic Posterior Cruciate Ligament and Posterolateral Corner Knee Instability

“…The patient lies in the lateral decubitus or in the seated position with the knee at 90° of flexion and the heel fixed to a stand. A lateral X-Ray is taken while the patient contracts his/her hamstring for at least 10 seconds (Chassaing et al, 1995;Jung et al, 2006). -Lateral stress view according to Gravity method (Staubli & Jakob, 1990).…”