Part 1: Series- Finger Joint Injuries and Extensor Tendon Ruptures/Sprains
The initial steps of management in finger injuries is highly important. Commonly the severity of injuries is ignored, decreasing the best outcomes of healing. Instead we should treat every ache and pain like a potential injury and learn to evaluate them for signs that we need help from our health care partner. This article focuses on the discussion of common tendon and ligament injuries of the finger and our self-care protocol for such.
It is common for visual signs of deformity to follow an injury to a finger joint or tendon. Long term swelling or abnormal size increases are common signs that an injury is present. Decreasing motion with splinting immediately is a common protocol for treating those injuries to help them to heal as best they can. But which ones do we splint and which ones do we keep moving while they heal?
The Basics of Anatomy: Finger joints and tendons.
Joint stability is provided for each joint of the finger by a dense interwoven connective tissue called the volar plate. Held with ligaments into this plate, each joint of the finger becomes stable unless used outside of its design.
On the top of each finger, a thick fibrous band runs out to the first joint of each finger, or the PIP (proximal interphalangeal joint) to extend it. The joint closest to the fingertip, the DIP (distal interphalangeal joint) is extended straight by two lateral bands on the back sides of each finger. Together, these extensor bands open each finger independently in a multitude of angles.
Once we understand the anatomy, we can better understand our injuries and their care. A complete understanding of your injury cannot be made by motion testing and visual inspection alone, if you heard a pop or snap or have swelling in the region with a lack of range of motion, it is highly recommended that you go in to your medical provider for films. Only from inspecting an X-Ray on 3 views (called a trauma series) can we fully see if you have a bony fracture and if your injury is in need of splinting.
-Pain on the back of the DIP joint.
-Deformity of the joint at rest (DIP joint).
-Inability to straighten the finger with pain on the back/top of the finger.
-Central slip extensor tendon injury.
-Evulsion of the tendon from the bone
-Fracture of the bone with a fragment where the extensor tendon attaches.
A common injury, the extensor tendon either tears off the bone or breaks a bit of the bone off (an avulsion fracture). This injury will not heal itself and is one that we are choosing to highlight as one worth visiting your doctor for...
Creating instability, this truly needs surgical attention. If left alone, this injury might evolve into a boutonniere deformity which is a permanent deformity of the finger (as shown as our article cover photo). Besides the visual changes, the difference between the flexor tendon and extensor tendon strength make the athlete more prone to other injuries of the finger and hand as the overall integrity of the stability of the region is compromised.
More than 30% evulsion of the bone from the surface of the joint.
Difficulty extending your relaxed finger with aid. (AKA passive range of motion).
If the injury was sustained by a child. They still have open growth plates (this increases risk).
If a bony fragment is displaced on X-ray more than 2mm.
If the joint line is incongruent or there is a volar subluxation.
If your finger has either of these above findings, you need to visit your family physician or orthopedic doctor immediately. You might be a candidate for a surgical consult and they will discuss conservative care in comparison with surgical intervention if your xrays confirm instability.
Other possible ailments with similar findings of decreased extension and tenderness without the above red flags are not surgical candidates. The three most common include the following:
1. Crimping injuries most commonly involving the DIP (Distal interphalangeal joint or the joint nearest the tip of the finger) which can be jammed into extention while crimping. This occurs in climbers that are more flexible than they are stable.
2. Pulley tendon inflammation or strains (A2 and A4 most commonly). When high amounts of inflammation and/or swelling exist, the finger becomes stiff and rigid. Over time and without therapy, these fingers can collect granular tissue consistent with healing and scar tissue and can adhere the structures that exist underneath the skin. In office I have seen athletes who cannot extend the finger due to adhering of the skin and the connective tissue underneath the pulley and flexor tendons.
3. Jammed Joints. Good old fashioned impact can limit motion and cause swelling that makes your joint look like a little sausage. This swelling should go down within a few days and should last only a few weeks maximum. If your joint is hit at an angle or is not jammed directly upon the fingertip, there may be ligament or tendon injury. If worried, go to your healthcare partner (MD/DO/DC/DPT)for examination and discuss.
If a true avulsion of the bone within the DIP joint exists or an extensor tendon avulsion injury exists, the area needs to be splinted. We try to stay away from this with most injuries but in this special case, these athletes need to allow this region to heal and to let the bone and tendon mesh back together. As the fibers try to knit the region into stability, you moving it or testing it will only limit the full extent of healing that can occur.
Don't leave the pinkie finger untaped if taping the middle and ring fingers, it is more prone to injury!
In the worst case scenario of tendon or bone injury, it is recommended that a splint be used to keep the joint in full extention for 6 weeks followed by 3 weeks of overnight splinting. This protocol allows the tendon to properly heal. If for some reason the finger is bent during this period, the splinting timeline must start over (6 more weeks). Most doctors will then do surgery if this does not allow the region to return to stable. We want the tendon to re-attach and the bone to strengthen back up to normal. This could take up to 8 weeks depending on how well it heals.
After the region has regained its stability, we need to improve its motion. The trade for a healthy tendon is now a joint that is rigid. Because of this, it is HIGHLY recommended that these athletes undergo physiotherapy and massage to return their tissues to flexible and to decrease the adhesions between their now healed tissues and the surrounding network of skin, connective tissue, bone, ligament, and tendon. Gentle slow work to return motion to the joint and a beginning rehabilitation program to return strength (and then climbing) will all progress nicely as led by your Health Care Partner and based on your unique situation.
1. Acute Finger Injuries. Part1: Tendons and Ligaments. Leggit. J and Meko. C. American Family Physician. Volume 73, Number 5 March 1, 2006.
2. Finger Radiology. M.J. Fuller. http://www.wikiradiography.net/page/Finger Radiography
3. Extensor Tendon injury at the DIP Joint. The Physicians Notebook. http://www.fpnotebook.com/ortho/Hand/ExtnsrTndnInjryAtThDpJnt.htm