Pronation External Rotation Stress Test for calcaneofibular ligament insufficiency

Strain was measured in the normal anterior talofibular ligament (ATF) and the calcaneofibular ligament (CF) using Hall effect strain transducers in five cadaveric ankles. These measurements were made in both ligaments with the ankle in neutral position and with the foot moving from 10° dorsiflexion to 40° plantarflexion in an apparatus that permits physiologic motion. The ankle ligaments were then tested with the foot placed in six different positions that combined supination, pronation, external rotation, and internal rotation. In the neutral position, through a range of motion of 10° dorsiflexion to 40° plantarflexion, the anterior talofibular ligament underwent an increasing strain of 3.3%. No significant strain increase was found with internal rotation. The only significant difference from the strains at the neutral position was in external rotation, which decreased strain 1.9%. In all positions, increased strain occurred with increased plantarflexion. The calcaneofibular ligament was essentially isometric in the neutral position throughout the flexion arc. The calcaneofibular ligament strain was significantly increased by supination and external rotation. However, with increasing plantarflexion in these positions, the strain in the calcaneofibular ligament decreased. Therefore, plantarflexion has a relaxing effect on the calcaneofibular ligament. Thus, the anterior talofibular and calcaneofibular ligaments are synergistic, such that when one ligament is relaxed, the other is strained and vice versa.

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Operative Treatment of Syndesmotic Disruptions Without Use of a Syndesmotic Screw: A Prospective Clinical Study

Foot & Ankle International ◽

10.1177/107110079401500801 ◽

1994 ◽

Vol 15 (8) ◽

pp. 407-414 ◽

Cited By ~ 87

Author(s):

Ken Yamaguchi ◽

Christopher H. Martin ◽

Scott D. Boden ◽

Panos A. Labropoulos

Keyword(s):

External Rotation ◽

Clinical Results ◽

Cadaveric Study ◽

Deltoid Ligament ◽

Prospective Clinical Study ◽

Fibular Fracture ◽

Static View ◽

Pronation External Rotation ◽

Rotation Stress

A new protocol for the selected omission of transsyndesmotic fixation in Weber class C ankle fractures was prospectively evaluated in 21 consecutive patients. As proposed in a previous cadaveric study ( J. Bone Joint Surg., 71A:1548–1555, 1989), the protocol suggested that transsyndesmotic fixation was not required if (1) rigid bimalleolar fracture fixation was achieved or (2) lateral without medial fixation was obtained (i.e., with accompanying deltoid tears) if the fibular fracture was within 4.5 cm of the joint. According to this protocol, only 3 of 21 patients (14%) required transsyndesmotic fixation. Ten of the patients who did not receive transsyndesmotic fixation underwent pronation-external rotation stress radiographs in a fashion analogous to the previous cadaveric study. At 1- to 3-year follow-up, no stress (N = 10) or static view (N = 18) widening of the mortise or syndesmosis was seen in any patient, which supports (with the above guidelines) a limited, rather than routine, use of supplemental transsyndesmotic fixation. Clinical results from this prospective study seem to substantiate previously proposed biomechanical guidelines for the selected omission of transsyndesmotic fixation. Given these guidelines, transsyndesmotic fixation was unnecessary in many cases and the need can be determined before surgery by assessing the integrity of the deltoid ligament and level of the fibular fracture.

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External Rotation Stress Test

The Physician and Sportsmedicine ◽

10.3810/psm.2002.08.404 ◽

2002 ◽

Vol 30 (8) ◽

pp. 47-47

Author(s):

Robert E. Sallis ◽

Selina Shah ◽

Kelly Richter ◽

Kurt Spindler

Keyword(s):

External Rotation ◽

Stress Test ◽

Rotation Stress

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The external rotation stress test for impairment of the infraspinatus and teres minor muscles

Physical Diagnosis of Pain ◽

10.1016/b978-0-323-71260-6.00076-9 ◽

2021 ◽

pp. 112-112.e1

Author(s):

Steven D. Waldman

Keyword(s):

External Rotation ◽

Stress Test ◽

Rotation Stress ◽

Teres Minor

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Three-Dimensional Analysis of Fibular Motion After Fixation of Syndesmotic Injuries With a Screw or Suture-Button Construct

Foot & Ankle International ◽

10.1177/1071100716666865 ◽

2016 ◽

Vol 37 (12) ◽

pp. 1350-1356 ◽

Cited By ~ 27

Author(s):

Jeremy M. LaMothe ◽

Josh R. Baxter ◽

Conor Murphy ◽

Susannah Gilbert ◽

Bridget DeSandis ◽

...

Keyword(s):

Sagittal Plane ◽

External Rotation ◽

Stress Test ◽

Coronal Plane ◽

Medial Malleolus ◽

Syndesmotic Injury ◽

Intact Specimen ◽

Suture Button ◽

Single Suture ◽

Rotation Stress

Background: Suture-button constructs are an alternative to screw fixation for syndesmotic injuries, and proponents advocate that suture-button constructs may allow physiological motion of the syndesmosis. Recent biomechanical data suggest that fibular instability with syndesmotic injuries is greatest in the sagittal plane, but the design of a suture-button construct, being a rope and 2 retention washers, is most effective along the axis of the rope (in the coronal plane). Some studies report that suture-button constructs are able to constrain fibular motion in the coronal plane, but the ability of a tightrope to constrain sagittal fibular motion is unknown. The purpose of this study was to assess fibular motion in response to an external rotation stress test in a syndesmotic injury model after fixation with a screw or suture-button constructs. Methods: Eleven fresh-frozen cadaver whole legs with intact tibia-fibula articulations were secured to a custom fixture. Fibular motion (coronal, sagittal, and rotational planes) in response to a 6.5-Nm external rotation moment applied to the foot was recorded with fluoroscopy and a high-resolution motion capture system. Measures were taken for the following syndesmotic conditions: intact, complete lateral injury, complete lateral and deltoid injury, repair with a tetracortical 4.0-mm screw, and repair with a suture button construct (Tightrope; Arthrex, Naples, FL) aimed from the lateral fibula to the anterior medial malleolus. Results: The suture-button construct allowed significantly more sagittal plane motion than the syndesmotic screw. Measurements acquired with mortise imaging did not detect differences between the intact, lateral injury, and 2 repair conditions. External rotation of the fibula was significantly increased in both injury conditions and was not restored to intact levels with the screw or the suture-button construct. Conclusion: A single suture-button placed from the lateral fibula to the anterior medial malleolus was unable to replicate the motion observed in the intact specimen when subjected to an external rotation stress test and allowed significantly more posterior motion of the fibula than when fixed with a screw in simulated highly unstable injuries. Clinical Relevance: Fixation of a syndesmotic injury with a single suture-button construct did not restore physiological fibular motion, which may have implications for postoperative care and clinical outcomes.

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Intraoperative Torque Test to Assess Syndesmosis Instability

Foot & Ankle International ◽

10.1177/1071100718816674 ◽

2018 ◽

Vol 40 (4) ◽

pp. 408-413 ◽

Cited By ~ 2

Author(s):

Nayla Gosselin-Papadopoulos ◽

Jonah Hébert-Davies ◽

G. Yves Laflamme ◽

Marie Beauséjour ◽

Jérémie Ménard ◽

...

Keyword(s):

External Rotation ◽

Stress Test ◽

Rank Test ◽

Direct Visualization ◽

Tibiofibular Ligament ◽

Signed Rank ◽

Fresh Frozen ◽

Signed Rank Test ◽

The Mean ◽

Rotation Stress

Background: In this cadaveric study, a new “torque test” (TT) stressing the fibula posterolaterally under direct visualization was compared with the classical external rotation stress test (ERT) and lateral stress test (LST). Methods: The anteroinferior tibiofibular ligament (AiTFL), the interosseous membrane (IOM), and the posteroinferior tibiofibular ligament (PiTFL) were sectioned sequentially on 10 fresh-frozen human ankles. At each stage of dissection, instability was assessed using the LST, ERT, and TT under direct visualization. Anatomical tibiofibular diastasis measurements were taken directly on cadavers and compared using the Wilcoxon signed rank test. Results: All 3 tests showed statistically significant motion in the syndesmosis when at least 2 ligaments were sectioned. The mean increase across diastasis with a 2-ligament section was 3.0 mm ( P = .005), 3.2 mm ( P = .005), and 4.8 mm ( P = .005) for the LST, ERT, and TT, respectively. The largest mean increase in diastasis was obtained with a complete injury using the TT and was 6.2 mm ( P = .008). With the TT, a 3.5-mm tibiofibular diastasis was 90% sensitive and 100% specific when 2 or more syndesmotic ligaments were sectioned. Conclusion: The TT was a more sensitive and specific tool for detecting syndesmosis instability than classic LST and ERT. Clinical relevance: Stressing the fibula in a posterolateral direction created a larger distal tibiofibular diastasis, which would be easier to detect in the intraoperative setting. The TT was more sensitive and specific to detecting a 2-ligament syndesmotic injury than the classic test and required less force to perform.

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