Introduction and Overview[edit | edit source]
Objective:
In this session, you will become familiar with the specific psychomotor skills involved in removing a cortical window and the rubric you will use to assess your skills.
Background:
In many cases of osteomyelitis, the clinician caring for the patient needs to be able to enter the intramedullary canal of the bone to debride purulent material and necrotic bone.
To safely enter a bone, making a cortical window is recommended. Making a window allows for instruments to be safely and easily passed into the intramedullary canal in order to do the debridement and cleaning of the inner core of the bone. Without a thorough debridement, the infection will not be able to be cleared.
The window should be made in the area where the majority of the necrotic material is present (as seen in the xrays) but also, we preferentially make the window in the metaphyseal area where blood supply is more robust so that there is better healing post-operatively. It is also preferred to make the window under an area where there is overlying muscle, as the overlying muscle will help with healing and prevent scarring of subcutaneous tissue and skin down to the bone.
To make the window, you will make a series of unicortical holes (just through the near cortex) in an elongated oval shape. After the holes are made, you will take an osteotome and position it along the drill hole line and mallet the osteotome to start to cut into the bone, connecting the drill holes. This is the importance of the holes – they both serve as a guide for the osteotome, while also helping reduce the risk of causing a fracture in the bone with the osteotome.
As you go around the oval with the osteotome, you may not go all the way through right away, particularly in thicker cortical bone. Work your way around the oval, to eventually cut through the full thickness of the cortex. Once through, the piece of cortical bone will be free. Often you need to use the osteotome to come under the piece and lever it up to lift it out of the bone. Set this aside. You will then have access to the intramedullary canal of the bone to do your debridement.
By the end of this Module, you will be able to:
- Use a rubric to self-assess and improve your cortical window removal skills.
- Drill multiple, uni-cortical holes with good spacing and timing.
- Complete the cortical window using an osteotome.
- Extract the cortical window smoothly and efficiently.
You will use this rubric to assess your own skills and to measure your progress over time as you learn to remove a cortical window on the bone simulator.
Assessment Rubric for Learning Target 5: I can perform the removal of a cortical window.
| SKILLS: | EMERGING (I am just getting started on this skill) | APPROACHING (I am still developing this skill) | MEETS (I am competent and confident in this skill) |
|---|---|---|---|
| 1. Drill multiple, uni-cortical holes in an oval shape | I am able to drill unicortical holes, but they are not well-spaced. | I am able to drill unicortical holes with good positioning in an oval shape most of the time. | I am consistently able to drill unicortical holes with good spacing and timing. |
| 2. Complete the cortical window using an osteotome | I have difficulty keeping the osteotome engaged along the line of the drilled cortical window. | I am able to keep the osteotome engaged along the window line, but it takes me considerable time to extract the cortical window. | I am able to consistently use the osteotome to connect the drill holes without slipping from the window line. |
| 3. Extract the cortical window using an osteotome or bone nibbler/rongeur | I have difficulty extracting the cortical window and often drive it further inward instead of lifting out smoothly and efficiently. | I am able to extract the cortical window smoothly and efficiently most of the time. | I am able to consistently extract the cortical window smoothly and efficiently. |
File:Performing a cortical window.mp4
Think through these questions:
- What is your timeline to work through this Module?
- How will you work with your learning partner? How will you give each other feedback?
- When will you meet with your mentor for feedback and discussion?
Materials needed[edit | edit source]
- Bone simulator (see Module 4)
- Electric or manual (egg beater) drill
- Osteotome
- Bone nibbler/rongeur
- Computer or mobile phone to watch instructional videos
- Mobile phone to take videos and something steady to place it on
Additional Resources and References on Drilling Bone
Removing a Cortical Window Skills Practice and Self-Assessment[edit | edit source]
Objective:
In this session, you will get hands on practice as you learn how to:
- Drill uni-cortical holes in an oval shape, with good spacing and timing.
- Complete the cortical window using an osteotome.
- Extract the cortical window smoothly and efficiently.
Refer to the rubric in Step 2 at the beginning of this Module (you may want to print out one or more copies). Use the rubric to assess the following and note if you are EMERGING, APPROACHING, or MEETING each of the sub-skills. This will help you know which knowledge and sub-skills require more practice. Please take notes on your self-assessment below.
- Row 1: How well are you able to drill unicortical holes in an oval shape?
- Row 2: How well are you able to complete the cortical window with the osteotome?
- Row 3: How well are you able to remove the cortical window?
SELF-ASSESSMENT NOTES:
Watch the video(s) to assess your skills and see where you can improve. You can also share the video(s) with your mentor and learning partner for feedback.
Continue to practice removing a cortical window until you are competent and confident with each skill. Re-watch the instructional videos as many times as you need. Over time, you should progress from EMERGING, to APPROACHING, to eventually MEETING the criteria for each sub-skill in the removing a cortical window rubric. Once you have determined that you MEET all of the sub-skills, you can move on to the next and final Module.