PURPOSE: The primary purpose of this paper is to introduce the WARPS/STAID classification system for patellofemoral instability. The secondary purpose is to establish the validity and reliability of the WARPS/STAID classification system. METHODS: Patients (n = 31) with a confirmed diagnosis of patellofemoral instability underwent a thorough knee history and physical examination with 3 raters. The raters graded each component of the WARPS/STAID classification system on a visual analogue scale (VAS). A single Global VAS WARPS/STAID score was graded after all other components of the classification system were completed. Intraclass correlation coefficient (ICC 2, 3) was calculated for each metric of the classification scale and for the Global score. Concurrent validity was assessed by correlating the WARPS/STAID score with the Kujala score. Subjects were assigned to one of three categories (WARPS, STAID, or mixed characteristics) according to the Total WARPS/STAID score to determine the level of agreement between the three raters. RESULTS: Intraclass correlation coefficient (ICC 2, 3) of the WARPS/STAID classification continuum ranged between 0.73 and 0.91 for the individual metrics of the classification. The ICC (2, 3) for the Global WARPS/STAID score was 0.75. The mean Kujala score (m = 61, SD 18) was significantly correlated with the total WARPS/STAID score (r = 0.387, p < 0.05). The majority of subjects were assigned to either the WARPS or STAID categories. CONCLUSION: This study introduced the WARPS/STAID classification system and established both validity and reliability in subjects with patellofemoral instability. LEVEL OF EVIDENCE: II.
PURPOSE: The primary purpose of this paper is to introduce the WARPS/STAID classification system for patellofemoral instability. The secondary purpose is to establish the validity and reliability of the WARPS/STAID classification system. METHODS:Patients (n = 31) with a confirmed diagnosis of patellofemoral instability underwent a thorough knee history and physical examination with 3 raters. The raters graded each component of the WARPS/STAID classification system on a visual analogue scale (VAS). A single Global VAS WARPS/STAID score was graded after all other components of the classification system were completed. Intraclass correlation coefficient (ICC 2, 3) was calculated for each metric of the classification scale and for the Global score. Concurrent validity was assessed by correlating the WARPS/STAID score with the Kujala score. Subjects were assigned to one of three categories (WARPS, STAID, or mixed characteristics) according to the Total WARPS/STAID score to determine the level of agreement between the three raters. RESULTS: Intraclass correlation coefficient (ICC 2, 3) of the WARPS/STAID classification continuum ranged between 0.73 and 0.91 for the individual metrics of the classification. The ICC (2, 3) for the Global WARPS/STAID score was 0.75. The mean Kujala score (m = 61, SD 18) was significantly correlated with the total WARPS/STAID score (r = 0.387, p < 0.05). The majority of subjects were assigned to either the WARPS or STAID categories. CONCLUSION: This study introduced the WARPS/STAID classification system and established both validity and reliability in subjects with patellofemoral instability. LEVEL OF EVIDENCE: II.
Authors: Christopher L Camp; Aaron J Krych; Diane L Dahm; Bruce A Levy; Michael J Stuart Journal: Am J Sports Med Date: 2010-08-17 Impact factor: 6.202
Authors: Edward G McFarland; Tae Kyun Kim; Hyung Bin Park; Carlos A Neira; Maria Isabel Gutierrez Journal: J Bone Joint Surg Am Date: 2003-11 Impact factor: 5.284
Authors: Peter Balcarek; Swantje Oberthür; Stephanie Hopfensitz; Stephan Frosch; Tim Alexander Walde; Martin Michael Wachowski; Jan Philipp Schüttrumpf; Klaus Michael Stürmer Journal: Knee Surg Sports Traumatol Arthrosc Date: 2013-09-05 Impact factor: 4.342