Identifying And Treating Stress Fractures And Lateral Ankle Sprains In Athletes

   As our population gets more and more active, it stands to reason that they will suffer from more and more sports-related injuries.

   In the adult population, we see this with the “weekend warrior” types, who have not been conditioned regularly to participate in strenuous activity. Alternately, we may see adult patients who take on an exercise regimen without seeking the proper guidance on how to progress in intensity.

   In the pediatric population, we are seeing more injuries than ever since many of these young athletes get no downtime between sports activities. They go from one sport to another without giving their bodies the much needed rest to heal any micro-injuries they may have sustained during the previous activity’s season of play.

   The two most common injuries we see in the aforementioned populations are metatarsal stress fractures and lateral ankle sprains, which also can present with peroneal tendon injuries or frank fractures of the fifth metatarsal.

How To Address Stress Fractures

   Much of the research on lower extremity stress fractures has been in the military population, which has a high incidence of tibial stress fractures, and the population of young ballet dancers, who may suffer from both tibial and metatarsal stress fractures.1 When it comes to stress fractures in ballet dancers, particularly fractures of the second metatarsal, these were initially attributed to a variance in the length of the second metatarsal with respect to the first. However, subsequent research has discounted this theory.2 Stress fractures were also commonly referred to as “hairline” fractures in the past but this terminology has fallen by the wayside.

   Stress fractures involve an excessive amount of stress on a bone that cannot compensate as it should. It becomes an imbalance of the bone breaking itself down via osteoclastic activity and building itself back up via osteoblastic activity. This assumes that there is no pathologic basis for such an imbalance as one may see when there are certain arthridities and/or cancerous pathologies within the bone itself.

   In most situations, a patient presenting with a stress fracture will note an increasing amount of pain in the midfoot. These patients typically say the pain first occurs at rest and subsequently occurs during and throughout their chosen activity. Patients may relate a certain amount of swelling to the dorsum of the foot but will most likely cite pain as the primary complaint.

   One of the difficulties of identifying a stress fracture is a potential lack of physical signs such as ecchymosis, or severe edema and pain associated with a frank fracture. Also be aware that in-office radiographic evaluation may not facilitate an accurate diagnosis. While the “tuning fork test” is somewhat helpful in the attempted diagnosis, it is a rather non-sensitive test and may have a high false negative rate.

   In patients in whom there is a high suspicion of a stress fracture, some alternate testing to consider may include a bone scan, computed tomography (CT) or magnetic resonance imaging (MRI) in order to pinpoint the location and severity of the injury accurately.

   Treatment of a stress fracture rarely involves surgery as this injury tends to respond very well to conservative management. Immobilization in a cast boot is indicated. One may encourage the patient to attempt light ambulation with the cast boot in an attempt to restore the balance of osteoclastic versus osteoblastic activity. However, physicians still need to provide immobilization to help speed recovery.

   Generally, a period of partial weightbearing in a cast boot of four to six weeks should allow the body adequate time to not only heal itself but also restore the balance of bone restoration and bone destruction. If this is not sufficient time to help patients return to their chosen activity, investigate another cause for the injury such as a more systemic etiology.

What You Should Know About Lateral Ankle Sprains

   The other very common injury is a lateral ankle sprain. These injuries tend to be much more easily identifiable as the patient generally presents with edema, ecchymosis and pain in the lateral ankle. These injuries also tend to be more dynamic acute injuries. With these injuries, patients can usually describe the incident of injury or impact, and give a much more defined time of injury.

   One of the most important and often overlooked aspects of the diagnosis of acute ankle sprains is the evaluation of both the peroneal tendons and checking for a potential fracture at the base of the fifth metatarsal. It is generally for this reason that in-office radiographs are indicated for these injuries. It is necessary to include the ankle in the radiographic studies as the same mechanism of injury is present in acute ankle fractures as well.

   One of the important questions to ask these patients during the initial evaluation is whether they heard anything during the injury like a “pop” or “snap.” Physicians should also ascertain whether the patient was able to ambulate immediately after the injury. Also ask whether the patient noticed ecchymosis and edema immediately, or if there was a lag in time between the injury and when he or she noticed these hallmarks.

Keys To Managing Anterior Talofibular Ligament Injuries

   Interestingly, some patients who present with a chronic injury of the lateral ankle describe a type of transient swelling of the lateral ankle as the day progresses. It is important to explain to these patients that if they sustained an injury to the anterior talofibular ligament (ATFL) — which is the most common ligament affected — since it is an intracapsular ligament, they may have now compromised their ankle joint capsule. This can cause joint fluid to exude through the injury and cause this transient edema. This may also increase their chances for arthritic changes within the ankle joint due to ineffective retention of this important fluid within the joint.

   If one identifies an acute injury to either the ATFL or the peroneal tendons, immediate non-weightbearing in a cast boot for several weeks is indicated. If you diagnose a fracture to either the ankle or the fifth metatarsal, proceed to determine the severity of the fracture. Then the physician must choose between long-term non-weightbearing cast immobilization or open reduction with internal fixation.

   After one has identified a ligamentous or tendinous injury and conservative management has failed, the physician should obtain MRI to further rule out the location of the injury within the tendon or ligamentous structure. Also determine the injury’s severity, specifically whether it is a through and through injury, a rupture or only a partial rupture. Generally, if immobilization is unsuccessful in relieving the patient’s symptoms, surgical intervention is required to restore the structure to a functional state.

   Another injury that MRI can help identify is an osteochondral lesion within the dome of the talus. An acute injury of this nature rarely shows up on an initial radiograph. This can lead to long-term complications if it is not addressed.

   One of the more recent advances in the surgical management of the acute partial ATFL rupture is the use of thermal capsular shrinkage of this ligament in an attempt to limit the morbidity associated with using tendonous grafting to repair the ligament. The postoperative recovery is quicker and the return to activity is also on a much shorter timeline.

   Whether one selects a surgical approach or has success with conservative management, many of these patients with lateral ankle sprains do require some form of physical therapy and bracing support of the affected ankle.

   One of the challenges in treating a lateral ankle sprain is the re-education of the mechanoreceptors within the ATFL. Once the ATFL is injured, it hampers the effectiveness of the mechanoreceptors within the ligament itself to provide the nervous system with important proprioceptive information.

   It is vital to re-establish this function as quickly as possible as this loss of proprioception has been associated with chronic injuries to this ligament, which ultimately can cause more severe injury and chronic ankle instability.

Dr. Raducanu is the President of the American College of Foot and Ankle Pediatrics. He is board certified by the American Board of Podiatric Surgery and is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Raducanu is in private practice in Virginia Beach and Norfolk, Va.

Dr. Richie is an Adjunct Associate Professor in the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University. He is a Fellow of the American Academy of Podiatric Sports Medicine.

References:

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