The Relationship Between Early-Stage Knee Osteoarthritis and Lower-Extremity Alignment, Joint Laxity, and Subjective Scores of Pain, Stiffness, and Function

Abstract

Context:Knee osteoarthritis (OA) is a debilitating disease that affects an estimated 27 million Americans. Changes in lowerextremity alignment and joint laxity have been found to redistribute the medial and/or lateral loads at the joint. However, the effect that changes in anteroposterior knee-joint laxity have on lower-extremity alignment and function in individuals with knee OA remains unclear.Objective:To examine anteroposterior knee-joint laxity, lower-extremity alignment, and subjective pain, stiffness, and function scores in individuals with early-stage knee OA and matched controls and to determine if a relationship exists among these measures.Design:Case control.Setting:Sports-medicine research laboratory.Participants:18 participants with knee OA and 18 healthy matched controls.Intervention:Participants completed the Western Ontario McMaster (WOMAC) osteoarthritis questionnaire and were tested for total anteroposterior knee-joint laxity (A-P) and knee-joint alignment (ALIGN).Main Outcome Measures:WOMAC scores, A-P (mm), and ALIGN (°).Results:A significant multivariate main effect for group (Wilks’ Λ = 0.30, F7,26 = 8.58, P < .0001) was found. Knee-OA participants differed in WOMAC scores (P < .0001) but did not differ from healthy controls on ALIGN (P = .49) or total A-P (P = .66). No significant relationships were identified among main outcome measures.Conclusion:These data demonstrate that participants with early-stage knee OA had worse pain, stiffness, and functional outcome scores than the matched controls; however, ALIGN and A-P were no different. There was no association identified among participants’ subjective scores, ALIGN, or A-P measures in this study.

Predicting Functional Coronal Knee Laxity in Pre-Operative TKA Patients Using Morphological Measurements

“…Obtaining stressed X-rays to determine functional laxity ranges however, is not practical for routine TKA pre-operative analysis and consequently we investigated whether patient specific knee laxity could be predicted from anatomical features on CT scan and radiographs. Previous investigations have found correlations between knee osteoarthritis, alignment and laxity [8], but have not investigated morphological measures on a 3 dimensional patient specific basis. At this stage knee laxity at 20° flexion has shown a significant correlation, indicating that with greater data, bone morphology may assist in characterising the soft tissue profile.…”