Essential Insights On Lateral Column Pain
Midtarsal joint stability plays an important role in cuboid syndrome. Newell and Woodle found that 80 percent of their patients with cuboid syndrome had pronated feet.3 In a normal foot, the subtalar joint is supinating during propulsion and the peroneus longus acts as a stabilizer of the forefoot as it assists in plantarflexing the first ray while using the cuboid as a pulley.
However, when the subtalar joint is pronating through the early phase of propulsion, the peroneus longus has a greater mechanical advantage because the foot is pronated and the midtarsal joint is unstable. Due to this pronated, unstable nature of the cuboid, the peroneus longus is able to sublux the cuboid during the propulsive phase of gait. This in turn can irritate the calcaneocuboid joint capsule and surrounding ligaments, as well as the peroneus longus tendon.
An inversion sprain can also cause subluxation or dislocation of the cuboid as well as stress the peroneal tendons and ligaments of the lateral column. The peroneus longus muscle may forcefully contract in response to an inversion stress in an attempt to restore medial ground contact and balance. This contraction can result in a medial rotation of the cuboid and/or disruption of the intertarsal ligaments.
A Closer Look At Peroneal Tendon Disorders
Peroneal tendon disorders are a commonly overlooked source of lateral column pain because it can be hard to differentiate them from injuries to the ligaments of the lateral ankle. Palpation of the peroneal tendons for defect or tenderness is an important part of the physical exam for a patient complaining of lateral column pain.
Peroneal tendon disorders typically fall into three categories including: tendonitis and tenosynovitis; tendon subluxation and dislocation; and tendon tears and ruptures.4
Peroneal tendonitis and tenosynovitis typically cause lateral ankle and or foot pain as a result of prolonged or repetitive activity. Anatomic variations of the lateral foot as well as ankle and hindfoot alignment can predispose patients to peroneal tendon disorders such as subluxation or tendon tears. The lateral retromalleolar groove can vary in shape and depth, which affects the stability of the peroneal tendons as they pass posterior to the fibula. A shallow or narrow retromalleolar groove can potentiate peroneal tendon subluxation and subsequent tendon pathology.
The musculotendinous junction of the peroneus brevis typically lies proximal to the superior peroneal retinaculum although it can occur more distally and posterior to the retromalleolar groove. Additionally, the peroneus quartus, an accessory muscle reported to be present in 10 to 22 percent of the population, runs posterior to the fibula. Either of these anatomical variations can cause stenosis in the retromalleolar groove and/or attenuate the superior peroneal retinaculum. A hypertrophied peroneal tubercle of the calcaneus can also result in peroneal tendon disorders as it increases mechanical stress on the peroneal tendons.
A cavovarus hindfoot creates a mechanical disadvantage for the peroneal tendons by increasing frictional forces at the lateral malleolus, peroneal tubercle and cuboid notch. The moment arm of the peroneal tendons is also lower and places the peroneal tendons at a higher risk for tendon disorders.
Why Fifth Metatarsal Fractures Lead To Lateral Column Pain
Fractures of the base of the fifth metatarsal typically result in lateral column pain and often physicians overlook this in the presence of an ankle sprain or fracture. The more common avulsion fracture has a good prognosis with non-operative treatment. An avulsion fracture occurs as a result of forced inversion with the peroneal brevis avulsing a small portion of bone at its insertion to the base of the fifth metatarsal. A true Jones fracture of the fifth metatarsal diaphysis can cause significant disability and results from vertical and mediolateral forces over the fifth metatarsal.