Joined: January 31, 2005
These are stress views of the ankle. The gloves are on to protect the hands from the rads, and to keep the overlay of the skeletal structure from interfering in the interpretation of the film. The point is to see the degree of instability in the ankle joint. For patients who we are unsure are unstable, or for whom the surgeon is considering for a reconstruction procedure but stability tests aren't clear, these are good views. I do not believe they are commonly done much anymore.
I don't happen to know the standards of what degree of tilt constitutes instability. J
Joined: January 19, 2005
it looks like they're both oblique views with more ankle joint space of the R than the L. i think B ankles are in PF/everted position. is the R ankle showing ligamental laxity of lateral ligaments? just guessing without reading the posts after the x-rays.
Joined: March 12, 2004
This is really cool...the talar test (inversion stress test) captured on an x-ray with either the Michelin Man or Stay-Puff Marshmellow man performing the test. I would suppose these radiographs are showing us lateral instability of the right ankle compared to the left.
I believe Brotzman and Wilk state that greater than 10 degrees difference compared to the contralateral side constitutes instability.
Joined: March 1, 2004
This is a talar tilt stress view radiograph comparing the symptomatic side (right) to the asymptomatic side (left) on this 24 year old female soldier.
The true stress radiologic criteria for diagnosing mechanical lateral ankle instability are controversial. Normal talar tilt values have been reported to range from 0° to 23° (1,2). Because of the wide variance of normal values, some authors feel that this test is not a reliable indicator of ankle instability (2). Others argue that anteroposterior and lateral stress views do not take into account the rotational instability that is occurring at the ankle and subtalar joint (3). This may explain the complaints of subjective ankle instability in the face of normal radiographic stress tests ("functional instability"). One study (4) demonstrated that a 10° difference in talar tilt between the injured and uninjured ankle was diagnostic of a sprain of both lateral ankle ligaments in 97% of cases. Most authors agree that a difference of 5° to 15° between the injured and uninjured side is diagnostic of mechanical ankle instability (5).
1. Rubin G, Witten M: The talar tilt angle and the fibular collateral ligaments: a method for the determination of talar tilt. J Bone Joint Surg 1960;42A:311-326 2. Seligson D, Gassman J, Pope M: Ankle instability: evaluation of the lateral ankle ligaments. Am J Sports Med 1980;8(1):39-42 3. Hintermann B: Biomechanics of the unstable ankle joint and clinical implications. Med Sci Sports Exerc 1999;31(7 Suppl):S459-S469 4. Chrisman OD, Snook GA: Reconstruction of lateral ligament tears of the ankle: an experimental study and clinical evaluation of seven patients treated by a new modification of the Elmslie procedure. J Bone Joint Surg Am 1969;51(5):904-912 5. Safran MR, Benedetti RS, Bartolozzi AR 3rd, et al: Lateral ankle sprains: a comprehensive review. Part 1: etilology, pathoanatomy, histopathogenesis, and diagnosis. Med Sci Sports Exerc 1999;31(7 Suppl):S429-S437
This particular patient had a difference of 17 degrees left to right. The measured angle is formed by drawing a straight line across the tibial plafond and a line across the dome of the talus. From my conversations with an orthopaedic surgeon the gold standard for ankle instability is arthroscopy. I personally feel in order to fully diagnose true ankle instability versus something like ligament laxity or someone with just poor proprioception there needs to be the ?total package?. Meaning that the patient should have several findings including; 1) patient history consistent with ankle instabililty, i.e. trauma or mechanism of injury and history of chronic ankle sprains 2) physical exam consistent with ankle instability. Positive talar tilt and anterior drawers when compared to healthy side 3) Ankle stress views showing the differences compared to healthy side as shown in studies listed above.
On a side note, from what I read the patient should undergo some sort of local anesthetic in the ankle before performing the talar tilt stress view so that you will not get any muscle guarding during the x-ray procedure. I have never seen this done.
Follow on question. What surgeries are performed to correct ankle instability?
< Message edited by Randy J Moore -- July 22, 2007 11:34:40 PM >
The local surgeons tend to do conservative treatments - Aircast, splinting etc etc. I haven't checked my Medline, but these fellows say that results of conservative care are equal or better than surgery in the long run.
Joined: August 25, 2000
I have not read about the specific surgeries mentioned for ankle instability, other than the conservative casting or bracing methods. Would be interesting to know what they specifically do if the conservative approaches do not work.
Joined: January 31, 2005
Though the primary repairs initially had little success, they are gaining in popularity.
I worked with a nationally known podiatrist at my last station, and he was doing almost all DPRs (delayed primary repairs) of the ligaments. I think most places the modified Brostrum is the most common procedure. J
Joined: May 11, 2004
See, that's where I would think that there needs to be balance in our clinical decision making processes. Given that this person has a substantial amount of laxity creating instability, then my interpretation would be that if the laxity was addressed then the pain would have a greater chance of being reduced. I wouldn't worry about the chronic pain issue until after the laxity was addressed and then see how the patient presents. At the same time, I do believe that time spent educating the patient on post-op anticipated expectations both overall outcomes and intial pain on the front end before the surgery could be helpful in preparing the patient to potentially have a more successful outcome with realistic post-op expectations.
Joined: February 14, 2003
From: Madison WI USA
Im with ya SJ, I was kind of being a smart a.... Part of the reason for this is the fact that in this case there is objective evidence for chronic pain, whereas in other cases, the objectivity is not there. Maybe, in those other cases, it is, and we just havent found it yet. Maybe it isnt, and the central pheomenon overrule. I marvel in how much we dont know yet. Im also pathologically black and white in my thought processes. How do I change that? Steve