REVIEWS OF DR. SCHULER
more about fx ankles draft
With the snow and ice fast approaching the number of patients heading to the emergency room with suspected ankle fractures is quickly rising! In previous Blogs we’ve talked about ankle fractures, but this week I want to talk about a different type of fracture associated with ankle injuries: the 5th metatarsal base fracture!
The 5th metatarsal bone is a long bone in the foot that connects the rearfoot to the 5th toe. It is one of five metatarsal bones in the foot, each corresponding to a digit. Fractures of the 5th metatarsal base (the end of the bone closest to the ankle) are commonly associated with classic ankle injuries where the foot turns inward.
There is a muscle that passes along the outside of the ankle and inserts into the 5th metatarsal bone at its base called the peroneus brevis (PB). With an ankle sprain or injury where the foot turns inward, the PB contracts and pulls on the 5th metatarsal base, sometimes so strong that it avulses, or pulls a piece of bone away from the rest of the metatarsal bone. Therefore, when you twist your ankle and have not suffered an ankle fracture, you may not be completely ‘home-free;’
You should be suspicious of a 5th metatarsal base fracture any time that you are suspicious of an ankle injury. However, residual pain along the outside of the foot along the 5th metatarsal bone is a good indicator of injury to that area. Try sliding your finger along the outside border of your foot from your 5th toe back towards your heel.Along the way you should feel a “bump” which is the landmark of your 5th metatarsal base. Pain in that are can be indicative of a fracture, as that is the most likely place where the PB would have pulled off a piece of bone. Be particularly suspicious if the pain in that area has not improved several days after your ‘ankle twisting incident.’
Fractures of the 5th metatarsal base are particularly tricky to treat because the blood supply to that area of the bone is delicate. In the area of such fractures, two blood supplies are coming together, and disruption of their connection via fracture can permanently hinder the healing process, as blood supply is imperative to bone healing.Keeping that in mind, early detection of a 5th metatarsal base fracture is important so that immobilization can be initiated as soon as possible. The goal of immobilization is to decrease motion at the site of the fracture to encourage healing making the delicate blood supply less of a factor!
There are several ways in which immobilization of the fracture site can be initiated and the choice depends on the severity of the fracture. If the fracture is well aligned and shows no gapping between fragments, conservative treatment with immobilization in a short leg cast is indicated. If the fracture is displaced and there is significant gapping between the fragments, the fracture is unlikely to heel unless the fragments are brought back closer together. In this case, surgery may be indicated to place a pin or screw across the fracture site and immobilize the fragment with the “hardware.” A short leg case is still indicated to ensure that the patient remains non-weightbearing and minimizes the risk on non-healing.
In either scenario, 4-6 weeks in a cast should be expected so that the bone has time to heal. Once healing is noted and pain in the area of the fracture is severely decreased or absent, transition into a walking cast and eventually back into a comfortable supportive sneaker can be allowed.
Next time you twist your ankle, don’t be fooled into thinking is just an ankle injury, unless you’ve been cleared by your Podiatrist and no 5thmetatarsal base fracture has been suffered!
Over the last year or so, we’ve covered many topics and have certainly hit on some of the more common pathologies in the world of Podiatric Medicine. Over the next month, I’m going to be blogging about some less common diagnosis and pathologies.
To start us off into the world of rare pathologies, we will be covering navicular fractures this week. A navicular fracture is rare but can be seen, especially in athletes. First, lets talk about what and where the navicular bone is.
The navicular is a bone in the foot also known as the scaphoid bone. It is located towards the inside of the foot (medially) between the heel and the metatarsals. It can be found by running your fingers along the inside of the foot starting at the heel and moving towards the toes. As you slide your fingers along your foot, the first small bump/bulge you feel indicates the location of the navicular. The bone extends from the medial side of the foot, half way across the top over to the outside (lateral side) of the foot. Picture a sideways teardrop-shaped piece of bone that serves as a stabilizer of the foot, particularly the arch.
The best way to discuss navicular fractures is to break them down by the type of fracture suffered. Navicular fractures come in 4 types, as classified by the Watson and Jones Classification System (here we go again: we Podiatrists classifying and naming everything)! Each type of fracture results from a slightly different mechanism of injury and, thus are treated according to that mechanism.
1. Avulsion fracture of the most medial side (fracture of the palpable bump along the inside of the foot). At this area of the bone a large tendon, known as the Posterior Tibial Tendon, responsible for supporting the arch of the foot, attaches. An avulsion injury occurs when increased tension is placed on the tendon while the foot is moving away from the body, whereby the strength of the tendon pulls off (avulses) the most prominent piece of the navicular bone. Most of these fracture fragments remain in close proximity to the main portion of the navicular and will heal properly with immediate immobilization via casting and non-weight bearing for at least 4 to 6 weeks.
2. Chip fracture off of the top surface of the bone. This type of navicular fracture is the most common of the 4 types (although still a rare injury) and can also be referred to as an avulsion injury. Although this time it is not a tendon that is pulling off a piece of bone, but rather a ligament on the top of the foot that becomes tensioned while the foot is moving downward and inward at the same time. If the avulsed fragment is small, casting with non-weight bearing for 4 to 6 weeks is indicated, but if the fragment is much larger surgery may be required to accurately reposition the fragments.
3. Fracture of the body. This type of navicular injury is the least common fracture type and typically results from direct injury, such as a can of soup tumbling out of the pantry and falling onto the foot! The fracture line usually extends from the top to the bottom of the foot, splitting the bone in half. If the two pieces remain close in proximity, casting with non-weight bearing for 4 to 6 weeks is adequate treatment. However, if the pieces become separated or if there are more than two pieces created with injury, surgery may be indicated to re-approximate the fragments and encourage a greater chance for healing.
4. Stress fracture of the body of the navicular. This diagnosis is commonly overlooked because the injury is very difficult to evaluate on standard x-ray therefore, diagnosis comes with a high index of suspicion on the part of your Podiatrist. Sufferers of navicular stress fractures are commonly track and field athletes who describe vague and diffuse pain in the midfoot region. If not recognized and treated with immobilization immediately, a stress fracture can lead to complete fracture.
Navicular fractures can be treated in a fairly straightforward fashion, by recognition and casting with non-weight bearing until healing has been achieved. Unless the fracture fragments are displaced (separated from one another), surgery can typically be avoided. Navicular fracture may not be the first injury to come to mind in foot and ankle injuries, as it is fairly uncommon, but it can be seen!
We just talked about what a tailors bunion is, including why it forms and how it can be treated conservatively. Just to refresh, a tailors bunion is much like the typical bunion except that it is located on the outside of the foot rather than the inside. The bone affected when a tailors bunion develops is the 5th metatarsal bone. There are a total of 5 metatarsal bones in the foot, each corresponding with a toe, such that the 5th metatarsal is located between the rearfoot and the 5th toe, along the outside of the foot.
Aside from an inherited bowing of the 5th metatarsal outward, most tailors bunions are caused by splaying of the foot with gait. This means that with each step, the foot widens out and when the sides of the foot come in contact with the shoe, excess pressure develops and eventually pain. As a result of the excess pressure, responses from both the skin and bone underneath the pressure area induce the formation of thickened skin (callus) and reactive bone growth on the head of the 5th metatarsal, creating the characteristic baby “bump” that is your tailors bunion.
There are a variety of conservative measures which we have already covered, so the aim this week is to briefly review a few of the more common surgical options, should all conservative methods fail.
Soft Tissue Procedures: Although there are various soft tissue procedures that can be used to correct for the traditional bunion located on the inside of the foot, because there are fewer and small structures surrounding the 5th metatarsal, 5th toe and outside of the foot, soft tissue procedures are typically unsuccessful and rarely attempted.
Bone Procedures: When addressing a tailors bunion there are two main options for which bowing of the metatarsal and reactive bone growth can be addressed. There is a “shave the bump” method and a “bone cut” method.
-Shaving the bump: This procedure basically involves removing or shaving off the outside portion of the 5th metatarsal head to prevent it from pushing up against a shoe. The reactive bone growth in addition to a small amount of the normal bone would be removed and smoothed down decreasing the size of the bump. This type of procedure does not require any pins or screws for fixation and is typically used for mild deformities with great success.
– Bone cuts: There are numerous procedures that can be performed where a bone cut would be made, but no matter which type of cut, all procedures aim to achieve the same result: decreasing the deformity and reducing pain/pressure. A bone cut allows the head of the bone (the portion closest to the toe) to be shifted over/inward that after healing reduces splaying of the foot with gait, decreasing pressure of the metatarsal bone against the shoe. This procedure does require a pin or screw that can be temporary or permanent depending on your Podiatrists preference, and is indicated for large tailors bunions.
As with any surgical procedure the risks and benefits should be considered and discussed with your Podiatrist. Complications with any of the tailors bunion procedures described above can include infection, scarring, recurrence of deformity, and transfer pain among others, although the risks of any such complications are minimal. Patients should expect anywhere from 2-6 weeks of recovery depending on the procedure selected and they should expect pain typical of healing during the recovery period, in addition to lingering swelling. Again, all conservative options should be explored prior to surgical intervention, but should surgery be appropriate, pa