Ankle sprains sideline many athletes each sports season. 80-90% of ankle ligament injuries involve the lateral ligaments. However, there may be other associated injuries that are overlooked or difficult to detect at physical exam. In 2011, 2 researchers set out to see what other injuries occurred with lateral ankle sprains.
From June 2011 to June 2013, researchers examined the MRI’s of 64 patients who had acute inversion ankle injuries. What they found will probably not surprise many seasoned orthopedic clinicians.
75% of patients had Anterior Talofibular Ligament (ATFL) Injury.
41% had injury to the ATFL and calcaneofibular ligaments (CFL)
5% had posterior talofibular ligament (PTFL) injury
71% of the patients with lateral ligament injuries also had concomitant findings
76% of the concomitant findings were bone bruising, 50% of those were deltoid injury, 22% had a fracture, 14% had osteochondral lesions, 8% had syndesmosis injury, and 3% had posterior talofibular ligament injuries (PTFL)
Researchers stated ankle sprains are most commonly inversion injuries with supination and plantar flexion of the foot and external rotation of the tibia. These sprains are classified as grades 1 through 3 in order of severity. In grade 1 injuries, there is stretch to the ligament with no increase in laxity; grade 2, macroscopic rupture with some increased laxity; and grade 3 sprains are a complete rupture. However, this grading system concentrates on the severity of the injury to the lateral ligaments, with no focus on the possibility of other concomitant injuries.
The researchers suggested that clinical assessment in the acute setting may not be reliable because it is limited by the patient’s pain. In a small study done by Frey et al, researchers found that physical exam was only 25% accurate in diagnosing grade 2 tears.
Approximately 30% and 74% of patients with injuries of the ankle ligaments have residual symptoms of pain or instability regardless of treatment. This suggests that other factors or associated injuries may have an impact on recovery.
So, what do we need to change? More MRI’s early on? Good luck getting approval from the insurance company for this! Besides, if the trend of increased back surgeries due to increased imaging is a predictor, we do not want to increase MRI’s for all acute ankle sprains. We just need to be more mindful of the incidence of concomitant injuries. Make sure you are utilizing the Ottawa Ankle/Foot Rules in every case, do not skimp on your soft tissue assessment, be aware of secondary areas of pain in your assessment, and continually assess for changes as treatment progresses. Concomitant injuries may mean more recovery time and increased referrals if patients are not improving.
Take your time with these patients. A simple ankle sprain may not be so simple after all.