Pulley Protection Splint

Items Recommended:

Below is a list of all items involved in the splinting process. Depending on your budget and professional setting, you can use as few or as many as you feel are appropriate. The set up cost can range anywhere from $40 – $400 depending on what you can reuse (frying pan, tongs, scissors spatula, etc…) and what you need to buy. For medical providers in the clinical environment recommend items are notated with an asterix. If you are a climber and not a medical provider, you likely have most of the equipment available and can substitute with everyday gear.

Dirtbag Tip:

If you are a climber and looking to make this on a budget, skip the equipment recommendations and try this: Use a pot instead of the skillet, instead of a thermometer just gradually increase heat until the plastic becomes malleable, skip the heat gun and use sandpaper, forget the mandrel – just wrap it around your finger, skip the spatula and use free chop sticks. You get the point…basically everything can be substituted for a dirtbag pulley splint set up – well except for the splinting material and tape.

Measure the Finger

• Measure the injured finger with a strip of paper towel that is roughly 1.5cm wide and 10cm long. (For people with longer fingers you may need to choose 2 cm wide. This will be the width of your PPS.) Overlap the paper towel strip and mark starting end with a pen.
  • **Using paper towel is better than a normal sheet of paper because the paper towel is easier to manipulate.
  • SAVE THIS PAPER TOWEL STRIP.
• Find mark estimate on mandrel
  • Use your paper towel on the mandrel to find what level you will use to wrap the splint around. This level will be where the paper towel wraps around and almost touches end. Or you can measure by touching each end of the paper towel to the edges of the plastic strip on the sides of the mandrel.
  • Save this mark on the mandrel for molding the soft thermoplastic around in a later step.

Heat the Material for the First Time

• Put splinting material in the pan for approximately 2 minutes or until the material becomes pliable
• Wait until the plastic becomes very pliable.
• Remove the thermoplastic cut out from the pan and immediately place the paper towel template onto the thermoplastic cut out.
  • Cut around the paper towel to create a piece of thermolastic that is the exact size and shape of the paper towel template.

Heat the Material for the Second Time

After you’ve cut the thermoplastic to be custom sized, put it back in the heating pan for approx 45-60 more sec.

• Pull out the thermoplastic strip and place it around the mandrel at the level you marked earlier. Wrap around just like you wrapped the paper towel template, until the ends of the plastic strip are separated only by the plastic side bar.
• Gently mold the thermoplastic strip around the mandrel taking care to form the splint over the plastic side bars on the mandrel. Don’t press too hard, or the thermoplastic may stick to the mandrel.
• Let the plastic harden on the mandrel for approx 60-120 sec, and then gently prise it off taking care not to deform the ring too much. Once there is minimal space between the thermoplastic and the mandrel, you can slide it off instead of opening the ring like a book.

Heat the Material for the Third Time

• Dip the edges of the ring into the hot water until the become pliable and cut any excess length off of the pulley protection splint

Heat the Material for the Fourth Time

Now you have a PPS in your hand, but you need to smooth the edges of the plastic. Otherwise there will be sharp edges that can damage the patient’s skin.

• Use the stationary heat gun in the vice to warm the edges of the PPS. (CAUTION: do not hold the splint too close or it will burn/melt. Also gently use pliers to hold the splint to avoid burning your fingers.)
• Gently smooth all edges and corners of the PPS using your finger tips. Repeat this step until all rough edges are smooth.
• Test the sizing of the splint on the patient’s finger. Place PPS on the distal-most aspect of the proximal phalanx (for A2 pulley injury.)

Make the Splint Comfortable

• Add moleskin to the dorsal portion of the splint to decrease the chances of skin breakdown. You can add it to both sides but this dorsal portion is more likely to experience more sheer force.

Securing the PPS Closed

This is the most important step for proper use of the PPS. If the splint is made perfectly, but the patient does not secure the splint tight enough, then the PPS is not doing its job it was made to do.

• Place PPS on the distal-most aspect of the proximal phalanx (for A2 pulley injury) right up against the joint line. When sizing and adjusting, ensure that the PPS does not drift proximally with movement.
• Use leukotape to secure the PPS closed. You must use leukotape because other tapes lack the tensile strength. The tape should be reapplied at least once per day, but at least recheck to make sure the tape and closure is tight. Tape does stretch over time.
  • To close the splint, place a strip of leukotape tape on the palmar side of the splint. Starting the tape from the palmar side and pulling upward ensures an upward directed force mimicking the pulley.
    • Taping Steps:
      1. Stabilize with ipsilateral thumb
      2. Stabilize the dorsal side of the splint with middle finger while pulling tape taut with contralateral thumb/index, and increase closure with contralateral ring finger.
      3. Seal the splint closed. Ensure that the dorsal/palmar lips are indeed closed tight when you seal the tape. REMEMBER: This is the most important step.

Advisory

• When fasting the pulley protection splint to the finger, make sure that you fully educate the climber on how tight to fasten so that it does not occlude blood flow. If the finger has a capillary refill of less than 2 seconds, looses circulation or has temperature changes, immediately remove the splint and reapply with less tension once blood flow, temperature and sensation return to the finger.

Closing Remarks

• If you are a medical practitioner feel free to use this article and the associated videos to learn or refine your thermoplastics skills
• If you are a climber and you have a finger injury, get it checked out and feel free to share these videos with your medical practitioner

Additional Considerations

• Splinting Material
  • The recommended splinting material is 1/8″ PRISM material that has a moderate resistance to stretch. However, there are some scenarios that may require a more pliable and material with minimal resistance to stretch. In this case, Orfit Classic 1/16 inch Smooth can be used.
    Use a tape measure ahead of time to objectively monitor swelling progress but not needed to measure for fit.
• Patient Comfort
  • If the patient reports discomfort with the PPS, there are several possible modifications that can be made to improve overall comfort.
    • If pain is felt on the dorsal aspect of the finger:
      • Add thicker moleskin to the PPS
      • Create a rounded, wider surface area on the PPS where it sits on the dorsum of the finger
    • If pain is felt on the palmar aspect of the finger:
      • Check capillary refill and if greater than two seconds, decrease the amount of pressure in the PPS by loosening the tension of the Leukotape
    • If pain is felt in the webspace of the fingers
      • Make sure that you heated and rounded all edges

Final Thoughts:

There are many ways to fabricate and mold thermoplastics. The methods in this article are a combination of research recommendations and clinical practice. However, if you have some great ideas, or if you feel something was left out of the article, post a comment to add to the discussion!

References:

• Schoffl VR, EINWAG F, STRECKER W, Schoffl I. Strength Measurement and Clinical Outcome after Pulley Ruptures in Climbers. Med Sci Sport Exerc. 2006;38(4):637-643. doi:10.1249/01.mss.0000210199.87328.6a.
• Schoffl VR, Schoffl I. Injuries to the Finger Flexor Pulley System in Rock Climbers: Current Concepts. J Hand Surg Am. 2006;31(4):647-654. doi:10.1016/j.jhsa.2006.02.011.
• Schneeberger M, Schweizer A. Pulley Ruptures in Rock Climbers: Outcome of Conservative Treatment With the Pulley-Protection Splint-A Series of 47 Cases. Wilderness Environ Med. 2016;27(2):211-218. doi:10.1016/j.wem.2015.12.017.
• Gnecchi S, Moutet F. Hand and Finger Injuries in Rock Climbers. Cham: Springer International Publishing; 2015. doi:10.1007/978-3-319-16790-9.
• Zafonte B, Rendulic D, Szabo RM. Flexor Pulley System: Anatomy, Injury, and Management CME INFORMATION AND DISCLOSURES. J Hand Surg Am. 2014;39:2525-2532. doi:10.1016/j.jhsa.2014.06.005.
• Hochholzer T, Schoeffl V, Zapf J. One Move Too Many — : How to Understand the Injuries and Overuse Syndroms of Rock Climbing. Lochner; 2003.
• Schoffl I, Einwag F, Strecker W, Hennig F, Schoffl V. Impact of taping after finger flexor tendon pulley ruptures in rock climbers. J Appl Biomech. 2007;23(1):52-62.