Category Archives: injury

Are you using the heel hook? Should you?

As climbing has progressed from simple vertical faces to more complex topography of the rock wall, largely brought on by recreational bouldering, so too have the techniques. One of these is the heel hook. It’s as if the first climber said to him or herself, “hey, that’s like an extra pair of hands down there. Let’s use those!”

And so began at least the documented use of the heel hook, specifically using the back of the heel to put pressure on a hold using your hamstrings. When climbers tell you that you should be using your legs more, they generally didn’t mean this. At least not with gusto, because this paper is a case series of 17 injuries from using this technique.

Heel hook in action

Now, I know what you’re saying. Lower extremity injuries are a small subset of climbing injuries (~5 to ~13%), and most of those are from falls instead of from using the heel as a climbing implement. But this should be looked at more closely, as the authors of this paper state that nearly 2/3rds of their patients were coming for a second opinion due to initial misdiagnosis.

So what injuries do you get from this? All of the climbers in the case series state that while using the heel hook, they had sudden dorsal pain in the knee, thigh, or pelvis. Seven reported a snapping sound as if a ligament had torn. All had a noticeable limp immediately, and point tenderness on exam. With US and MRI, the authors discovered 8 strains, and 9 torn muscles or ligaments. Of note, only 2 required surgery, and the rest were treated conservatively.

Interesting enough is that 6 of the tears were in the pelvis (5 in the biceps femoris alone) in a pattern more common with soccer (football) players,. The 2 knee injuries were similar to those of martial arts injuries from a similar but different heel hook. The velocity there leads to more ACL injuries however.

Prevention is obtained (in the words of the authors) by thorough stretching and flexibility exercises, and a good warmup routine. They also note that people should not use the heel hook ambitiously, as knowing their own limits will prevent injury. They also feel that MRI is not necessarily overkill for pelvic injuries and professional climbers.

The “Heel Hook”—A Climbing-Specific Technique to Injure the Leg

Dislocations? Put your shoulder into it!

Shoulder dislocations. Few procedures are more fulfilling in the emergency department. A little intra-articular lidocaine, some ketamine (always the answer), some propofol, and you’ve nearly instantaneously fixed a painful condition. Thankfully we’ve moved on from the barbaric techniques pictured below.

But this blog isn’t about reducing a shoulder in the emergency department using procedural sedation. It’s about the wilderness. So what are you supposed to do when it happens to someone on your trip, or heaven forbid, yourself? Between skiing, climbing, kayaking, mountain biking, and Pokemon Go, there are lots of activities that can result in shoulder dislocations at a scene distant from advanced medical care.

There are a few options other than openly cursing. At least one doesn’t have a name yet, and another is the Davos Technique, which was brought to my attention by none other than Tim Horeczko (@EMtogether). There are more, but I’m only going to talk about these two today.

First is the sin nombre technique, which I will refer to as the German technique after the location of the authors. It involves the following steps:

1.The practitioner holds the patient’s wrist with the left hand (in the case of a left shoulder dislocation) and the patient’s elbow with the right hand.
2.With the elbow in 90° of flexion, the glenohumeral joint is flexed forward to 90°.
3.While still in flexion, the glenohumeral joint is adducted until the elbow reaches the midline of the body; it is important to continue this movement until this landmark is completely reached.
4.Then, internal rotation of the shoulder is performed. During this step, the patient’s elbow must stay at the landmark described above. At 25° to 30° of rotation, a mild resistance is usually encountered.
5.The last step of the maneuver consists of applying a constant internal rotation pressure to overcome this mild resistance without pain. Reduction is usually achieved at approximately 30° of internal rotation.

For the visual learners, it is demonstrated in the video below.

The authors published their paper after a 50 month prospective observational trial that enrolled 39 patients older than 16. Of note, no pre-reduction xrays were performed, diagnosis was made clinically by deformation, pain, and decreased range of motion. All reductions were made without sedation, analgesia, or anesthesia, including alcohol.
Of the 39 dislocations, reduction was 95% successful on first attempt, and success was 100% on the second attempt on the 2 that failed the first. Mean dislocation time was nearly 4 hours, and reduction time was 6 minutes. Pain on a visual analog scale was low, and at least according to their followups, there was no need for surgery after reduction, nor were there any complications.
100% success without medications puts this at the top of list of possible techniques, tied with scapular manipulation. The downside to this technique (and many others) as far as wilderness medicine goes is that it pretty much requires a second participant. The arm movements would be nearly impossible to perform on yourself.

The Davos Technique is pretty trendy, as it just came out in JEM. However, it has been around awhile first described in 1993 by Boss, Holzach, and Matter. They worked at Davos Hospital. Their reduction rate was 60%, and further descriptions of this maneuver had similar rates. It is performed by following these steps:

The patient is sitting on his bed holding his injured extremity with his other hand. He is asked to flex his ipsilateral knee as much as possible and, with a little help, he passes both hands in front of the flexed knee. The hands are then tied together using an elastic band, preferably at the level of the wrist joint and not at the fingers, as this way the patient doesn’t have to concentrate on keeping the fingers crossed, and thus, can be more relaxed. Another important point is that the elbows should be kept close to the thigh, as this way the shoulders can be more relaxed. The two wrists can either be tied on the proximal tibia or simply held in place by whoever is treating the patient. At that point the physician can sit on the patient’s foot and instruct the patient to lean his head back, let his shoulders roll forward, extending the arms and relaxing all the muscles. By extending the neck, the patient exerts a constant traction on the injured shoulder and the dislocation is reduced without any need for additional maneuvers on the physician’s part. Once the shoulder is reduced, it is immobilized in a sling, and postreduction x-ray studies can be obtained.

Or, again, watch the video.

This paper retrospectively evaluated 100 patients with shoulder dislocations who had the Davos Technique performed on them over a period of 18 months. 82% of them had received analgesia prior to reduction, with morphine given nearly 40% of the time. Reduction was only successful in 86 patients, and they don’t list the number of attempts of the Davos Technique. 4 of them were reduced using a different technique, and the last 10 went under general anesthesia.
However, 8 of the 14 failures had psychiatric problems or dementia, and for a technique that requires patient effort, this could drastically decrease success rate. Of note, the 18 patients who didn’t get pain medications were all successful with Davos. Their complication rate was zero, just as with the German technique. It seems that this could be successful as an auto-reduction by interlocking your fingers, but some people may not have the strength to keep their hands together. The new authors recommend against it specifically. If you use the band, it again requires a second participant. I can’t read in German, so if anyone wants to pull the original Boss et al paper, let me know what their thoughts were on the matter.
In the end, it looks like both techniques are suited for wilderness reduction of shoulder dislocations because they are well tolerated, have minimal apparent complications, and don’t require the use of medications.

You’ll note that I recommend either of these techniques over the Riggs method, demonstrated below.

And should you think this will never happen, think again.

Reduction of Acute Shoulder Dislocations in a Remote Environment: A Prospective Multicenter Observational Study.
Also available as FOAMed!
Reducing a Shoulder Dislocation Without Sweating. The Davos Technique and its Results. Evaluation of a Nontraumatic, Safe, and Simple Technique for Reducing Anterior Shoulder Dislocations.

Komodo dragons: Myth vs Reality

The Komodo dragon is a creature that inspires fear and mysticism in many. It’s got all the characteristics of a good monster movie: only found on rare tropical islands, large, and possessing magical saliva that can kill. First identified by the west in 1910 by Dutch sailors, they reported the lizards could spit fire and reached 7m in length. In reality the lizard can only get up to 3m and can weigh 70kg, and none have been identified as either breathing or spitting fire.

Komodo dragon (Varanus komodoensis), Komodo National Park, Indonesia

This review comes after a zoo worker was bitten on the hand by a small Komodo dragon. She had transient hypotension, and a retained tooth on xray. This was not removed, and after loose approximation (Ed. note: never do this), she was discharged on antibiotics. Thankfully the tooth came out on its own, and she did not develop a deep space infection. After this case report, the authors decided to do a literature review, knowing that it would help them get published.

Many of us are taught in school that Komodo dragon saliva is a possibly venomous, potentially fatal concoction of particularly virulent bacteria, including E. Coli, Staphylococcus, Streptococcus, and Pasteurella. These bacteria live in the rotting flesh that they leave in their mouth. But what is that based on?

It turns out, not much. The “facts” we have in textbooks, zoos, and medical literature are based on one guy’s book written in 1981. While Walter Auffenberg was the Jane Goodall of Komodo dragons, moving to the island and studying them in their natural habitat, his results haven’t been widely reproducible. And, more importantly, komodos don’t carry rotting flesh in their mouth. They fastidiously clean their teeth and gums. Now, perhaps the water buffalo does die of sepsis after being bitten, but if it does, it’s because it runs into murky water with fresh wounds, and not from bacteria in the mouth of the lizard. So, the “bacteria as venom” concept is just as dead in the water as the buffaloes.

So what about the venom aspect? The author of that study (Fry) was able to identify glands in the lower jaw that could potentially be venom glands. Furthermore, the extract of those glands does in fact contain proteins that inhibit blood clotting similar to snake venom. However, there isn’t any evidence that the venom actually affects the prey or is secreted in any significant amount during bites. The teeth lack venom grooves present in every other venomous animal (including the shrew). On the plus side, the author did come up with the “grip, rip, and drip” model of lethality from komodos.

Then why do animals die after being bitten by a large, reptilian predator? For the same reasons they die after being bitten by any large animal. Direct trauma, blood loss, and hypovolemic shock (and by eating).

Our findings are also in accord with the view that the killing technique of V. komodoensis is broadly similar to that of some sharks and Smilodon fatalis (saber cat). Despite obvious anatomical differences, these unrelated predators kill or are thought to have killed (respectively) large prey by using relatively weak bite forces amplified by sharp teeth and postcranial input.

They have strong neck muscles and serrated teeth, so after they bite they pull away, tearing holes in the prey that then bleeds to death. Is it possible that venom can increase this bleeding? Sure, but it’s also possible that it doesn’t.

So then why did this patient become hypotensive? Likely a vasovagal response. And given that the bite was on the hand, it’s appropriate to put the patient on antibiotics. But maybe we can finally stop propagating the magical thinking associated with komodo dragons.

Bitten by a Dragon

Further enjoyable reading
National Geographic
A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus

Is there anything a SAM splint can’t do?

Deciding what to carry in your medical kit on an expedition is hard. You don’t want to leave anything out, but you can’t carry an entire hospital on your back. I mean, the wheels on the slit lamp really suck at crossing rough terrain. So you have to decide what goes and what doesn’t. Thus the reason for much of the improvisation inherent in wilderness medicine. An item that only does one job had better be the only item that can do that job, or it is extra weight.

C collars are one of those items. Now, ignoring the fact that many of them aren’t good at their job to begin with, they really aren’t good for much else. Sure, you could maybe improvise a pressure dressing out of it, but what else are you going to do? And while some of them do lay flat, they’re still pretty long and take up space that could be used for something else.

Enter the SAM splint®*. Waterproof, moldable, and able to be cut to size, it can be used pretty much anywhere on the body. And everyone has seen the picture of one being used to immobilize the cervical spine. But does it work well in that role?

Improvised C Collar in Auckland

These authors put it to the test against a Philadelphia collar using 13 EM resident “volunteers”. I’m sure they were paid well for their time. Using a goniometer they measured maximal extension, rotation, and lateral flexion. They found that no statistically significant difference in any one measurement, but looking at the results the SAM does appear to allow slightly more rotation and extension, while doing a better job of limiting lateral flexion. This likely is due to the bulkiness of the SAM laterally.

While the method of measuring falls short of a radiographic gold standards, and the number of subjects is low (but powered to an 11° difference per the authors), it looks like the SAM splint, in fact, is just as good as a Philly collar at immobilizing the C spine. I am OK with it in an awake patient, but would add more reinforcement to an unconscious patient.

Comparison of a SAM Splint-Molded Cervical Collar with a Philadelphia Cervical Collar

*I’m using SAM splint to cover all the moldable splints out there, similar to how Xerox is used to cover all photocopiers. I do not receive any money from SAM Medical Products® for using their name here. You are welcome to use other splints, but this article only used the SAM.