THE LATERAL LIGAMENT COMPLEX: INSIGHTS AND REHABILITATION

The most common musculoskeletal injuries in athletes are ankle sprains. Over 90% of these are inversion injuries causing partial or complete rupture of the anterior talofibular ligament and the calcaneofibular ligament. The rehabilitation of an ankle injury can be challenging for the practitioner. In this article we look at the research available on the rehabilitation of complex ankle injuries.

BY DAVE HANCOCK, MSC MCSP BHSC INTRODUCTION

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nkle sprains are the most common musculoskeletal injuries in athletes.

Studies show that 90–95% of ankle sprains are inversion injuries causing partial or complete rupture of the anterior talofibular ligament (ATFL) and occasionally the calcaneofibular ligament (CFL) (1,2). The rehabilitation of an ankle injury can be

challenging and awkward for the practitioner, depending on the complexity of the injury and the necessity and pressure to return an athlete back to their level of performance. As ankle injuries in sport are so common, a solid diagnosis and a rehabilitation programme are essential. Most individuals with a sprain of the ATFL

recover fully and have no long-term side effects. However, some suffer chronic pain, stiffness, persistent swelling and recurrent “giving way”, with functional and/or mechanical instability (3,4). These episodes have been reported in 10–60% of patients following an initial ankle ligament sprain (5–7). The sensation of the ankle “giving way” has led to the diagnosis of functional instability as opposed to mechanical instability, in which there is excess laxity of the ligament structures and thus of the ankle joint. Tropp (8) described functional instability as a motion beyond one’s control that does not exceed the

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physiological range of the ankle joint. This article looks at the research surrounding the rehabilitation of proprioception and strength in lateral complex ankle injuries, and gives the author’s own experiences in the practical treatment and rehabilitation of such injuries.

ANATOMY The time taken for the athlete to return to play is dependent on the structures involved and the severity of the injury. The ATFL is the smallest (20mm long,

10mm wide, 2mm thick) and the weakest of the lateral ligaments (Fig 2.). It is frequently damaged during inversion injuries with the foot in the plantar-flexed position, when the ligament is placed on full stretch and does not have the safety of the ankle mortice to protect the joint. The ATFL and posterior talofibular ligaments (PTFL) are blended with the ankle joint capsule. In severe injury resulting in large ankle oedema, ATFL/PTFL and capsular tearing must be suspected.

The third lateral ligament structure, the CFL, is a stronger, cord-like ligament; it is much longer (20mm) and thicker (3mm) than the ATFL and PTFL. This ligament is often not injured in isolation and has more of a stabilising effect on the subtalar joint rather than the ankle joint itself. It does not blend with the ankle joint capsule. The inferior tibiofibular ligament may be

damaged during supination or an external rotatory force. This ligament injury is often missed on examination and can be the reason why so many mild to moderate ligament injuries take longer to heal than first expected. The inferior tibiofibular ligament is a firm, fibrous, flattened band that extends obliquely downwards and laterally from the tibia on to the anterior medial aspect of the distal fibula (Fig. 2). It is often known as the sling/base to the syndesmosis of the tibia and fibula complex. This ligament can be identified by a dial/screw test (Fig. 1): the examiner cups the calcaneus with one hand while placing the other hand on the anterior aspect of the tibia with the knee bent to 90°. By fixing the tibia and externally rotating the calcaneus, and indeed the ankle complex, a stress is applied, causing diastasis of the mortice. If injury to this ligament is suspected, then pain and apprehension will prevail.

Figure 1: External rotation test sportEX medicine 2008:38(Oct):14-19