THE INFLUENCE OF ANTERIOR KNEE PAIN AND LATERAL TIGHTNESS ON KNEE FUNCTION IN TOTAL KNEE ARTHROPLASTY. Filiz Can*1; Murat Bozkurt2; Zafer Erden1; Volkan Aygul2 1. School of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey; 2. Department of Orthopaedics, Orthopaedic Surgeon Emergency Care, Ankara, Turkey PURPOSE: The purpose of this study was to determine the effect of anterior knee pain and lateral tightness on knee functions in the patients undergone TKA. BACKGROUNDS/SIGNIFICANCE: Although complications of total knee arthroplasty rarely involve patellofemoral joint and lateral retinaculum, anterior knee pain and/or lateral pain are the more problematic conditions in patellofemoral joint of the patients with total knee arthroplasty (TKA). Pain in the anterior region of the knee has an inhibitory effect on quadriceps muscle contraction led to failed extensor mechanism of the knee. Anterior knee pain is often associated with improper tracking of the patella within the femoral trochlear notch. Pathology of the lateral aspect of the knee can cause a complex clinical problem, which is called "lateral knee pain syndrome". Iliotibial band syndrome is the most common cause of lateral knee pain. Clinical features of iliotibial band syndrome include pain and palpable tenderness over the lateral femoral condyle. Pain is exacerbated by downhill running and by repetitive flexion-extension movements. Many patients have iliotibial band tightness. Pain in the lateral knee or lateral leg is commonly seen in clinical practice, but is not often attributed to lateral hamstring and/or iliotibial band tightness. Bozkurt et al found that intensity of lateral knee pain and lateral tightness are highly correlated. Although some author recommended that release of the lateral patellar retinaculum can be used to treat patellofemoral instability and to balance the extensor mechanism during knee replacement operations most of the studies in the literature have been focused on anterior or lateral knee pain in patients with patellofemoral pain, not involved the patients with TKA. However anterior knee pain and lateral tightness may be seen in patients operated for TKA and they may affect the knee score and/or functions as being determinant of TKA management. SUBJECTS: 20 patients underwent knee arthroplasty (12 unilateral and 8 bilateral) participated in this study. There were 18 females and 2 males with a mean age of 63.42 ±7.62 (range 50 to 78 years). Patients who had undergone a revision or any corrective surgery and those who had an infection, diabetes, peripheral vascular and upper or lower motor neuron disease were excluded. METHODS AND MATERIALS: The patients were measured for anterior knee pain intensity level in rest and in activity according to the Visual Anolog Scale. Their lateral tightness and tenderness were assessed using the Ober's test and palpation. Knee score were recorded using Knee Society Scoring Scale included knee score and function score ANALYSES: Pearson Coefficient Test was used to determine the correlations between the lateral tightness, anterior knee pain. The significance level was set at p <0.05 and p<0.01. RESULTS: Their mean follow up was 5.45±3.95 months (range between 3 to 12 months). It was found a highly negative correlation between the anterior knee pain at rest and knee score(r =-0.739, p<0.01) while there was a highly negative correlation between activity pain and function score (r = -0.708, p<0.01) in addition to the knee score (r = -0.646, p<0.01). There was a positive correlation between lateral tightness and activity pain (r=0.506, p<0.05). There was also a correlation between lateral tightness and function score (r= -0.549, p<0.05), whereas no correlation between knee score (r=-0.29, p>0.05). CONCLUSIONS: The etiology of anterior and lateral knee pain is probably multifactorial. However this study implicated that the anterior knee pain and lateral tightness are the predictor factor in poor functioning of the knee. If the possible causative factors in those problems can be solved or prevented, the expectation of the success may be higher in outcome of TKA. FUNDING SOURCE: . KEYWORDS: total knee arthroplasty, Total knee arthroplasty, Anterior knee pain, Lateral tightness, Knee functions Copyright 2009 by the American Physical Therapy Association. Requests for reprints should be directed to the corresponding author of the article. Educators, students, and other academic customers may receive permission to reprint copyrighted material from Physical Therapy (ISSN 1538-6724) by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Other types of customers who want permission to reprint should contact the APTA Editorial Office, Attn: Physical Therapy.