We retrospectively reviewed the hospital records of 68 patients who had been referred with an injury to the posterolateral corner of the knee to a specialist knee surgeon between 2005 and 2009. These injuries were diagnosed based on a combination of clinical testing and imaging and arthroscopy when available. In all, 51 patients (75%) presented within 24 hours of their injury with a mean presentation at eight days (0 to 20) after the injury. A total of 63 patients (93%) had instability of the knee at presentation. There was a mean delay to the diagnosis of injury to the posterolateral corner of 30 months (0 to 420) from the time of injury. In all, the injuries in 49 patients (72%) were not identified at the time of the initial presentation, with the injury to the posterolateral corner only recognised in those patients who had severe multiple ligamentous injuries. The correct diagnosis, including injury to the posterolateral corner, had only been made in 34 patients (50%) at time of referral to a specialist knee clinic. MRI correctly identified 14 of 15 injuries when performed acutely (within 12 weeks of injury), but this was the case in only four of 15 patients in whom it was performed more than 12 weeks after the injury. Our study highlights a need for greater diligence in the examination and investigation of acute ligamentous injuries at the knee with symptoms of instability, in order to avoid failure to identify the true extent of the injury at the time when anatomical repair is most straightforward.
While injury to the posterolateral corner is accepted as a relatively common occurrence associated with rupture of the anterior cruciate ligament, posteromedial meniscocapsular injury has not previously been recognised as such. In a prospective assessment of 183 consecutive reconstructions of the anterior cruciate ligament this injury was observed in 17 cases, giving it an incidence of 9.3%. Clinically, it was associated with a mild anteromedial rotatory subluxation and it is important not to confuse this with posterolateral rotatory subluxation. In no case was this injury identified by MRI. The possible long-term clinical relevance is discussed.
Since 1994, the proportion of women seen with ACL injury doubled from 12% to 25% The proportion of skiing related injuries trebled from 9% to 28% The average age at presentation rose by 6.5 years from 26.5 to 33 The average age of the skiers is 41 and 90% of them are female
In 1994, 62% of the injuries were sustained during soccer and rugby, in 2004 58%. In 1994, 9% of injuries were sustained during skiing, in 2004 28% – a 300% increase. In 1994 the average age was 26.5, in 2004 33. When this increase was examined in detail the average age of the skiers was 41, the soccer players 31 and the rugby players 27. Clearly there has been a change in the demographics of ACL injury which may have a significant impact in providing NHS services for the ACL injured patient in the UK.
Of the 11 patients who had an arthroscopy, 4 were told that they had an ACL injury. None of the 15 who had an MRI scan were told that they had an ACL injury.
We present a series of four patients with what we have termed the snapping pes syndrome. This is a painful clicking and catching experienced at the posteromedial corner of the knee when moving from flexion to extension. Clinical examination and real time ultrasound are the most useful diagnostic tools. If medical treatment is unsuccessful surgical excision of both the semitendinous and gracilis tendons is indicated for relief of persistent symptoms.