Like any injury, a knee injury can differ from mild ligament strains to complex joint damage. As an outcome, it affects mobility, strength, and overall quality of life. The effects of knee injury can be evaluated both in terms of their effect on health-related quality of life or disability and handicap.
In this context, knowledge of patient-reported measures of knee function is important for comprehensive assessment of rheumatology conditions in both clinical and research settings. They help track recovery, know the treatment effectiveness, and guide return-to-activity decisions with scientific precision.
Here, we’ll be explaining the top 4 rating systems for knee injury treatment that are widely recognised and clinically validated knee assessment tools used in physiotherapy and orthopaedic practice.
What are Knee Instruments and Rating Scales?
Knee instruments and rating scales are clinical tools widely used by physiotherapists, orthopaedic specialists, and sports medicine professionals. These are responsible for translating symptoms, such as pain severity, into quantifiable data.
There are two main categories of knee instruments, including:
➔ Subjective (Patient-Reported) Instruments: These rely on how the patient feels and functions in daily activities. At its core, these assess the pain, mobility, and quality of life. KOOS, Lysholm Score, and IKDC Subjective Form are some of its examples.
➔ Objective (Clinician-Reported) Instruments: Objective instruments are totally based on a physiotherapist’s or surgeon’s evaluation. For that reason, they are used to identify ligament stability, range of motion, swelling, and strength. However, the most used instruments for the same include the Cincinnati Knee-Rating System and IKDC Objective Form.
Now that you’ve understood what they are used for, let’s briefly review the types of rating systems for knee injury treatment…
The IKDC Rating System
IKDC stands for the International Knee Documentation Committee, developed by a panel of internationally recognised orthopaedic surgeons. On its initial day, it included 7 parameters related to the knee. These parameters aim to reflect both impairment and disability.
Under this rating system, patients are graded into 4 different grades, including normal, nearly normal, abnormal, and severely abnormal. Amongst each of these categories, the worst grading determined the final outcome. In the later years, this system was further supplemented with a questionnaire related to different subjective factors, including the symptoms, ability to function, and sports activities.
As per the clinical evaluations, the perfect IKDC score is 100. This score indicates a fully functional, symptom-free knee. Moreover, the study demonstrates that patients with ACL reconstructions score somewhere between 85 and 95 within just a year of surgery.
The Cincinnati Knee-Rating System
This rating system was originally designed for athletes. Moreover, it combines both subjective and objective measures to evaluate knee function after injury or surgery. Did you know that the first Cincinnati knee-rating scale was published in 1983? This system is used to focus on pain or swelling levels, instability episodes, functional capacity, and sport-specific performance.
At its core, it has 11 components consisting of sections that measure physical examination, instrumental knee stability, testing, and radiographic findings. As per some research findings, Cincinnati scores correlate strongly with return-to-sport readiness. And due to this, it has become a preferred scale among sports medicine professionals.
A score of 80 indicates the readiness for moderate physical activity; in particular, the 90+ score reflects the full return to sports.
The Knee Osteoarthritis Outcome Score (KOOS)
Most commonly used to track symptoms or progress of patients having both acute injuries and degenerative conditions like osteoarthritis. This particular score was developed rigorously to address patient-relevant evaluation of knee injuries. Moreover, it was developed in the WOMAC (Western Ontario and McMaster Universities osteoarthritis index).
The KOOS is one of the most comprehensive outcome measures available. It mainly includes 5 subscales like pain, symptoms, activities of daily living, sport or recreation function, and knee-related quality of life. Each of these subscales is scored from 0 to 100, where 0 indicates the need for medical intervention and 100 indicates no symptoms and excellent function.
In addition, KOOS differ from Lysholm-Tegner, IKDC, Cincinnati, and Marshall-HSS. Plus, it had validity, responsiveness, reliability, no floor or ceiling effect, and reliability. Overall, this score was thoughtfully documented before it was actually used for the first time.
Lysholm-Tegner Rating System
This rating system is one of the earliest and most trusted tools used for the assessment of ligament injuries, especially ACL and meniscal tears. Back in the days, the Lysholm score was first presented in 1982. At its core, the Lysholm-Tegner scale merges symptom assessment with activity level grading. It goes like this:
➔ The Lysholm score (0–100) assesses limp, locking, instability, pain, swelling, stair climbing, and squatting.
➔ The Tegner scale (0–10) ranks physical activity level, from sedentary life to elite sports.
Similar to, different activities put different demands on the knee, and different patients push themselves to carry out different activities; it is therefore considered important to grade activities in a standardised way.
The main advantage isn’t just a comparison of different patients, but to determine changes in activity levels of the same patients at different times.
Which Score is Best?
After a detailed evaluation of each of the 4 scores, each one has its own advantages and disadvantages. However, the Cincinnati and IKDC are comprehensive approaches that evaluate most aspects of knee injury. On the flip side, the Lysholm-Tegner system is relatively simpler and only evaluates symptoms and activities for further knee pain treatment. Other than that, the Lysholm-Tegner and the KOOS do not summarise the objective functions as well as subjective results in the same way. Consequently, this can limit its usefulness in athletic or post-surgical evaluations.
Final Words
Why do you need to know about this? Well, understanding knee injury rating scales will let you know your condition better and where you are in your healing journey. From the clinician’s perspective, these are useful to deliver targeted yet high-quality rehabilitation.
These tools or scores are perfect to transform patient recovery from subjective “feeling better” to true progress backed by science. If you and someone you know are having knee pain, then you can consider getting checked by experts like Care N Cure physiotherapists. Our specialists make the most of evidence-based scales like IKDC, KOOS, Lysholm–Tegner, and Cincinnati to monitor every milestone and deliver the best outcome at your disposal.
