Detailled Information

Noble PC, Scuderi GR, Brekke AC, Sikorskii A, Benjamin JB, Lonner JH, Chadha P, Daylamani DA, Scott WN, Bourne RB. Development of a new Knee Society scoring system. Clin Orthop Relat Res. 2012 Jan;470(1):20-32

The new Knee Society Knee Scoring System

Validity and Internal Consistency of the New Knee Society Knee Scoring System

Rationale of the Knee Society Clinical Rating System

Translation and Validation of the German New Knee Society Scoring System

Translation and validation of the new knee society knee scoring system into Spanish: Spanish KSS translation

Cross-cultural adaptation and validation of the Japanese version of the new Knee Society Scoring System for osteoarthritic knee with total knee arthroplasty

https://www.kneesociety.org/assets/2011KSS%20Support%20Materials.pdf

The final design of the new Knee Society Scoring System consists of four subscales: (1) Objective Knee Score (seven items; 100 points), (2) Satisfaction Score (five items; 40 points), (3) Expectation Score (three items; 15 points), and (4) Functional Activity Score (19 items; 100 points). It includes versions to be administered preoperatively and postoperatively.

It varies according to the subscale:

• Objective Knee Score: “Alignment” has a maximum of 25 points and is determined on a weight-bearing AP radiograph measuring the femoral-tibial (Anatomic) axis. “Instability” allows a maximum of 25 points for a knee that is stable in the coronal and saggital axis. “Joint Motion” allows one point for each 5° of joint motion. Unlike the old scoring system that allowed a maximum of 25 points the new system allows greater than 25 points for patients with greater than 125° of motion. There are deductions for flexion contracture and extension lag. The presence of recurvatum is not specifically addressed however patients with recurvatum will have significant ligament laxity in other planes that is captured in the “Instability” category of the objective score. Maximum allowable points 25+ “Symptoms” category contains two 10-level scales, ranging from “none” to “severe” for each patient to rate their pain with walking on level ground and on stairs/inclines. The patient starts with 10 points on each scale for a painless knee with deductions of up to 10 points deductions as indicated by the patient’s response on each pain scale. There is an additional question regarding how “normal” the knee feels to the patient. Maximum allowable points 25.
• Patient Expectations is a three-question fifteen-point scale that is collected pre-operatively and post-operatively. 
• Patient Satisfaction is a five-question 40-point scale that is collected preoperatively and at each follow-up visit.
• Functional Score is composed of four subgroups (Walking and Standing, Standard Activities, Advanced Activities, Discretionary Activities) and has a maximum score of 100.