Knee impingement syndromes.

Abstract Introduction: The so-called knee impingement syndromes are very frequently reported in both professional and amateur sportsmen. Purpose: The objective of our study was to classify the most frequent knee changes responsible for such syndromes considering both pathology and diagnostic work-up. Material and methods: Our patients complained of aspecific symptoms related to articular meniscal, ligament or cartilage, conditions. The site of pain was periarticular and there was no apparent sign of acute traumatic events. All individuals, aged 16–55, practised sports at different levels and women were the majority of the sample. The study was carried out from 1995 to 1997 and all the medical records presented in occasion of the sports-medicine check-up were reviewed. Results: The sites of symptom onset were divided into medial, lateral, anterior and posterior. For each of them the most frequent conditions which could be defined as impingement syndromes, were defined paying particular attention to the possible methods of diagnosis useful to classify the disorder. As for anterior syndromes, patellofemoral disorders were the most frequent findings. They were associated with either incorrect torsion movements of the lower limbs or local dysplasia. Alterations in the single skeletal and cartilage structures were reported. Always referring to anterior syndromes, Hoffa's fat pad imflammation and the jumper's knee were a less frequent finding. As for posterior impingement syndromes, the most frequent abnormalities involved the insertional tract of the midcalf muscle associated with bursa reaction and insertional popliteus hypertrophy. As for medial syndromes, the most frequent abnormality involved the parapatellar synovial fold whose symptoms can be often mistaken for a meniscal injury. Less frequent is the involvement of the 'pes anserinus' tendinitis and the insertional enthesopathy of the semimembranosus muscle. As for lateral syndromes, the phlogistic involvement of the distal insertional tract of the broad fascia tensor tendon with bursa reaction is very frequently reported, while the inflammation of the popliteal tendon and of the femoral bicipital tendon is less common. Conclusions: Although less frequent than meniscal and ligament injuries, impingement syndromes must be taken into due consideration when looking for knee disorders resorting to different diagnosis methods. Diagnostic imaging is very useful in this regard as it allows a proper and correct diagnosis procedure for any single condition.