Functional Status

Five subjective functional outcome measures were common among studies: (1) Lysholm,⁹ (2) International Knee Documentation Committee (IKDC),¹⁰ (3) Meyer’s Rating Scale,¹¹ (4) Knee Outcome Survey,¹² and (5) Hospital for Special Surgery.¹³ A brief description of these outcome instruments follows.

The Lysholm scale is designed to document the patient’s evaluation of function. It is a conditionspecific outcome measure that contains 8 domains: limp, locking, pain, stair climbing, use of supports, instability, swelling, and squatting.⁹ An overall score from 0 to 100 points is calculated, with 95 to 100 points indicating an excellent outcome; 84 to 94 points, a good outcome; 65 to 83 points, a fair outcome; and less than 65 points, a poor outcome. The instrument has face validity and acceptable construct and criterion validity, as well as test-retest reliability and adequate responsiveness.¹⁴

The IKDC scale has 2 versions. The older version included a subjective patient-rated assessment within a generally physician-rated form (now Knee Examination Form). The subjective portion included 2 patient-rated questions that ask, “How does your knee function?” and “How does your knee affect your activity level?” Patients provide a rating of normal (A), nearly normal (B), abnormal (C), or severely abnormal (D). The question with the lowest rating provides the score for that patient.^10,15 The latest version of the IKDC contains a separate form titled “The Subjective Knee Evaluation Form”¹⁰ that is an 18-item, knee-specific questionnaire designed to detect changes in patients with a variety of knee conditions. The questions address 3 domains: physical symptoms (7 items), sports activities (10 items), and function before injury (1 item). The resulting total score is out of 100 possible points, which represents perfect knee function. This instrument has face validity and demonstrated construct validity, excellent testretest reliability, and sensitivity to change.^10,15

Meyers and coworkers¹¹ developed a rating scale to measure the functional ability of patients after treatment for knee dislocations. They defined “excellent” as the ability to return to work or previous level of activity without impairment and with a stable knee; “good” included having knee symptoms that did not preclude the patient’s return to normal occupation and activities of daily living. In this classification, pain is present but is considered an annoyance, and symptoms of instability are unusual or minimal. A rating of “fair” means the patient is performing all activities of daily living but has difficulty walking upstairs, walking on tiptoes, or running, and tends to avoid such activities. Finally, a “poor” functional rating is assigned to patients who cannot work and who are unable to perform daily activities.

The Knee Outcome Survey was developed to measure symptoms and functional limitations for patients with a variety of knee disorders, including ligamentous and meniscal injuries.¹² The Knee Outcome Survey consists of two scales, the Activities of Daily Living Scale and the Sports Activity Scale. The Activities of Daily Living Scale measures symptoms and functional limitations during activities of daily living. The score ranges from 0 to 100 points, with 100 points indicating an absence of symptoms and functional limitations during activities of daily living. The Activities of Daily Living Scale has been shown to be a reliable, valid, and responsive measure of symptoms and functional limitations during activities of daily living in individuals with a variety of knee injuries. The Sports Activity Scale measures symptoms and functional limitations experienced during sports activities. The Sports Activity Scale score ranges from 0 to 100 points, with 100 points representing the absence of symptoms and functional limitations during sports activities.¹²

Return to Activity

Two scales are used to measure patient activity level: (1) the Tegner Activity Level Scale and (2) the IKDC activity level scale. The Tegner Activity Level Scale rates the level of activity on a scale of 0 (off of work) to 10 (competitive contact sports).¹⁶ The IKDC activity level scale measures return to activity on four levels: I is return to intensive activity, II is moderate activity, III is light activity, and IV is remain sedentary.

Ligament Stability

The overall IKDC Knee Examination Form assesses the function of the knee based on 4 factors: (1) subjective assessment, (2) symptoms, (3) range of motion (ROM), and (4) ligament examination. These factors are rated as normal (A), nearly normal (B), abnormal (C), and severely abnormal (D).¹⁷ The overall final IKDC rating is based on group ratings for function, symptoms, ROM, and laxity. The worst problem area qualification defines the overall final qualification.

Lysholm Scale

Werier and colleagues¹⁸ found that the average Lysholm scale score of 85 (95% confidence interval [CI], 80–90) in the reconstructed group was significantly greater than the average score of 69 (95% CI, 57–81) in those patients who were treated conservatively. When comparing the components of the Lysholm, the reconstructed group had a better ability to climb stairs and experienced less symptomatic instability. Similarly, Richter and investigators¹⁹ found that the Lysholm score was significantly greater in those who underwent surgical treatment (78.3 ± 13.4) compared with those who had nonoperative treatment (64.8 ± 16.3).

International Knee Documentation Committee Subjective Score

Rios and coauthors²⁰ report the IKDC subjective score in terms of having excellent, good, fair, or poor results. The authors did not provide a definition of these classifications. The surgical group (n = 21) had 4 patients with excellent results and 10 patients with good results, whereas none of the patients in the conservatively managed group (n = 5) had excellent or good results. In a similar study, Wong and colleagues²¹ found that operative patients had a significantly greater average IKDC score (75.8 ± 10.0) compared with the conservative group (63.7 ± 9.1), whose average was considered suboptimal.

Meyer’s Rating Scale

According to the Meyer’s Rating Scale, Meyers and researchers¹¹ found that of the 13 patients in the conservatively managed group, 10 reported poor functional outcome, 2 fair, and 1 good. Three patients in the surgical group (n = 20) were rated as poor, 3 fair, 11 good, and 3 excellent. The authors conclude that the surgical group had better outcomes after treatment compared with those patients who did not undergo ligament repair. Similarly, Rios and colleagues²⁰ reported that all of the patients in the conservatively managed group (n = 5) were reported to have fair or poor functional outcomes on the Meyer’s scale, whereas only 2 patients were rated as fair and 2 as poor in the surgical group (n = 21). Sixteen patients in the surgical group had excellent or good results.

Lysholm Scale

Harner and colleagues⁶ found that the 19 patients who underwent acute surgery had an average Lysholm score of 91 ± 7.0 points, compared with 80 ± 16.9 points for the 12 patients whose surgery was delayed. Although the acute group had a greater average score than the chronic group, this difference did not reach statistical significance. Similarly, Tzurbakis and coauthors²² report a mean Lysholm score of 88.3 ± 11.9 for the acutely treated patients and a mean score of 81.7 ± 13.3 for the delayed group (P > 0.05). Similar differences were observed in Liow and investigators’ study³ in which those patients who underwent surgery during the acute phase had better functional ratings (87; 95% CI, 81–91) than those patients who underwent late reconstruction (75; 95% CI, 53–100). All acutely treated knees had a Lysholm score of more than 80 compared with only 5 of the 14 (36%) knees with delayed treatment. Likewise, Wascher and coauthors⁴ report a greater Lysholm score for patients treated acutely compared with chronic patients, with a mean score of 91.3 and 79.3, respectively. Finally, Fanelli and coauthors²³ report no statistically significant difference in the Lysholm score between acute and delayed treated knees; although no data were provided to support these conclusions.

International Knee Documentation Committee Patient Subjective Assessment

Tzurbakis and coauthors²² report that 30 patients in the acutely treated group (n = 38) considered their knee to be normal or nearly normal. Only 5 of 10 patients treated in the delayed phase rated their knee as normal or nearly normal. This difference was statistically significant.

Meyer’s Rating Scale

Harner and colleagues⁶ report that 16 of 19 patients in the acute group had an excellent or good rating, and 3 had a fair rating. Of the 12 patients in the delayed group, 7 received an excellent or good rating, 2 received a fair rating, and 3 received a poor rating. The difference between the acute and delayed groups was not statistically significant. Similarly, Wascher and coauthors⁴ found that 4 patients who underwent surgery in the acute phase (n = 9) had an excellent rating and 5 had a good outcome, whereas no patients were classified as fair or poor. In the delayed group (n = 4), 2 patients were rated as excellent, 1 rated as fair, and 1 rated as poor.

Knee Outcome Survey

One study⁶ evaluated patients using the Knee Outcome Survey. The average score on the Activities of Daily Living scale for the acutely treated patients was 91 ± 6.4, and the patients who received delayed treatment had an average score of 84 ± 11.8. Despite the trend toward a better outcome in the acutely treated patients, this difference was not statistically significant. On the Sports Activity Scale, the patients in the acute group had a significantly greater average score (89 ± 10.3), compared with those in the delayed group (69 ± 27.9) points.

Using their own classification, Noyes and Barber-Westin⁵ had all patients complete a separate rating of their perception of the overall outcome and knee condition, rated as poor, fair, good, very good, or normal. Three patients in the acute group (n