James J. Irrgang

Development and Validation of the International Knee Documentation Committee Subjective Knee Form

A committee of international knee experts created the International Knee Documentation Committee Subjective Knee Form, which is a knee-specific, rather than a disease-specific, measure of symptoms, function, and sports activity. The purpose of this study was to evaluate the reliability and validity of the new International Knee Documentation Committee Subjective Knee Form. To provide evidence for reliability and validity, we administered the final version of the form, along with the Short Form-36, to 533 patients with a variety of knee problems. Analyses were performed to determine reliability, validity, and differential item function related to age, sex, and diagnosis. Factor analysis revealed a single dominant component, making it reasonable to combine all questions into a single score. Internal consistency and test-retest reliability were 0.92 and 0.95, respectively. Based on test-retest reliability, the value for a true change in the score was 9.0 points. The International Knee Documentation Committee Subjective Knee Form score was related to concurrent measures of physical function (r = 0.47 to 0.66) but not to emotional function (r = 0.16 to 0.26). Analysis of differential item function indicated that the questions functioned similarly for men versus women, young versus old, and for those with different diagnoses. In conclusion, the International Knee Documentation Committee Subjective Knee Form is a reliable and valid knee-specific measure of symptoms, function, and sports activity that is appropriate for patients with a wide variety of knee problems. Use of this instrument will permit comparisons of outcome across groups with different knee problems.

Development of a patient-reported measure of function of the knee

The purpose of the present study was to demonstrate the reliability, validity, and responsiveness of the Activities of Daily Living Scale of the Knee Outcome Survey, a patient-reported measure of functional limitations imposed by pathological disorders and impairments of the knee during activities of daily living. The study comprised 397 patients; 213 were male, 156 were female, and the gender was not recorded for the remaining twenty-eight. The mean age of the patients was 33.3 years (range, twelve to seventy-six years). The patients were referred to physical therapy because of a wide variety of disorders of the knee, including ligamentous and meniscal injuries, patellofemoral pain, and osteoarthrosis. The Activities of Daily Living Scale was administered four times during an eight-week period: at the time of the initial evaluation and after one, four, and eight weeks of therapy. Concurrent measures of function included the Lysholm Knee Scale and several global measures of function. The subjects also provided an assessment of the change in function, with responses ranging from greatly worse to greatly better, at one, four, and eight weeks. The Activities of Daily Living Scale was administered to an additional sample of fifty-two patients (thirty-two male and twenty female patients with a mean age of 31.6 years [range, fourteen to sixty-six years]) before and after treatment within a single day to establish test-retest reliability. Factor analysis revealed two dominant factors: one that reflected a combination of symptoms and functional limitations and the other, only symptoms. The internal consistency of the Activities of Daily Living Scale was substantially higher than that of the Lysholm Knee Scale (coefficient alpha, 0.92 to 0.93 compared with 0.60 to 0.73), resulting in a smaller standard error of measurement for the former scale. Validity was demonstrated by moderately strong correlations with concurrent measures of function, including the Lysholm Knee Scale (r = 0.78 to 0.86) and the global assessment of function as measured on a scale ranging from 0 to 100 points (r = 0.66 to 0.75). Analysis of variance with repeated measures revealed significant improvements in the score on the Activities of Daily Living Scale during the eight weeks of physical therapy (F2,236 = 108.13; p < 0.0001); post hoc testing indicated that the change in the score at eight weeks was significantly greater than the change at four weeks and that the change at four weeks was significantly greater than that at one week (p < 0.0001 for both). As had been hypothesized, the patients in whom the knee had somewhat improved had a significantly smaller change in the score, both at four weeks (F1,189 = 33.50; p < 0.001) and at eight weeks (F1,156 = 22.48; p < 0.001), compared with those in whom the knee had greatly improved. The test-retest reliability coefficient (intraclass correlation coefficient[2,1]) was 0.97. These results suggest that the Activities of Daily Living Scale is a reliable, valid, and responsive instrument for the assessment of functional limitations that result from a wide variety of pathological disorders and impairments of the knee.

Evidence of validity for the Foot and Ankle Ability Measure (FAAM).

Background: There is no universally accepted instrument that can be used to evaluate changes in self-reported physical function for individuals with leg, ankle, and foot musculoskeletal disorders. The objective of this study was to develop an instrument to meet this need: the Foot and Ankle Ability Measure (FAAM). Additionally, this study was designed to provide validity evidence for interpretation of FAAM scores. Methods: Final item reduction was completed using item response theory with 1027 subjects. Validity evidence was provided by 164 subjects that were expected to change and 79 subjects that were expected to remain stable. These subjects were given the FAAM and SF-36 to complete on two occasions 4 weeks apart. Results: The final version of the FAAM consists of the 21-item activities of daily living (ADL) and 8-item Sports subscales, which together produced information across the spectrum ability. Validity evidence was provided for test content, internal structure, score stability, and responsiveness. Test retest reliability was 0.89 and 0.87 for the ADL and Sports subscales, respectively. The minimal detectable change based on a 95% confidence interval was ±5.7 and ±-12.3 points for the ADL and Sports subscales, respectively. Two-way repeated measures ANOVA and ROC analysis found both the ADL andSports subscales were responsive to changes in status (p < 0.05). The minimal clinically important differences were 8 and 9 points for the ADL and Sports subscales, respectively. Guyatt responsive index and ROC analysis found the ADL subscale was more responsive than general measures of physical function while the Sports subscale was not. The ADL and Sport subscales demonstrated strong relationships with the SF-36 physical function subscale (r = 0.84, 0.78) and physical component summary score (r = 0.78, 0.80) and weak relationships with the SF-36 mental function subscale (r = 0.18, 0.11) and mental component summary score (r = 0.05, −0.02). Conclusions: The FAAM is a reliable, responsive, and valid measure of physical function for individuals with a broad range of musculoskeletal disorders of the lower leg, foot, and ankle.

Reliability and diagnostic accuracy of the clinical examination and patient self-report measures for cervical radiculopathy

Study Design. A blinded, prospective diagnostic test study was conducted. Objectives. To assess the reliability and accuracy of individual clinical examination items and self-report instruments for the diagnosis of cervical radiculopathy, and to identify and assess the accuracy of an optimum test-item cluster for the diagnosis of cervical radiculopathy. Summary of Background Data. Although cervical radiculopathy remains largely a clinical diagnosis, the reliability and diagnostic accuracy of clinical examination items, individually or in combination, for cervical radiculopathy is largely unknown. Methods. Patients with suspected cervical radiculopathy or carpal tunnel syndrome received standardized electrophysiologic examination of the symptomatic upper quarter followed by a standardized clinical examination by physical therapist examiners blinded to diagnosis. Diagnostic properties were assessed using a neural impairment reference criterion standard. Results. The study involved 82 patients. More than two thirds of 34 clinical examination items had reliability coefficients rated at least fair or better, and 13 items had likelihood ratio point estimates above 2 or below 0.50. A single diagnostic test item cluster of four variables was identified and produced a positive likelihood ratio point estimate of 30.3. The 95% confidence intervals for all likelihood ratio point estimates in this study were wide. Conclusions. Many items of the clinical examination were found to be reliable and to have acceptable diagnostic properties, but the test item cluster identified was more useful for indicating cervical radiculopathy than any single test item. Upper limb tension Test A was the most useful test for ruling out cervical radiculopathy. Further investigation is required both to validate the test item cluster and to improve point estimate precision.

Loss of motion after anterior cruciate ligament reconstruction

We did a retrospective review and follow-up examina tion to investigate the incidence, risk factors, and out come of patients who developed loss of motion after arthroscopic anterior cruciate ligament reconstruction. Two hundred forty-four patients with a minimum fol lowup of 1 year were reviewed. Loss of motion (defined as a loss of extension of more than I0° or flexion of less than 125°) was identified in 27 patients for an overall incidence of 11.1%. Factors associated with loss of motion included acute reconstruction (less than 1 month from initial injury), male sex, and concomitant medial collateral ligament repair or posterior oblique ligament reefing or both. Twenty-one patients required surgery to regain their motion; three patients required a second procedure. Twenty-one of 27 patients with loss of motion under went a detailed followup and were compared with 24 randomly chosen controls who had a normal range of motion after anterior cruciate ligament reconstruction. At followup, patients who experienced loss of motion had a significant decrease in noninvolved to involved knee extension and flexion compared to the control patients. There was no difference between our patients and the controls regarding patellofemoral problems, anterior knee laxity, and functional strength. Sixty- seven percent of patients with loss of motion had a good or excellent result in comparison to 80% of the controls.

Primary Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction A Preliminary 2-Year Prospective Study

Background The anterior cruciate ligament consists of 2 functional bundles, the anteromedial bundle and the posterolateral bundle. Single-bundle anterior cruciate ligament reconstruction is the current standard for the treatment of anterior cruciate ligament deficiency. However, a significant subset of patients continues to report residual symptoms of instability after such reconstruction. Hypothesis Anatomic double-bundle anterior cruciate ligament reconstruction may more closely restore normal kinematics of the knee by reproducing the native anatomy. Study Design Case series; Level of evidence, 4. Methods We report the current clinical outcomes of the initial 100 consecutive patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction with an average follow-up of 2.1 ± 0.5 years. All patients were prospectively followed to document range of motion, ligamentous laxity, and functional strength, as well as activity and sports participation. Results Side-to-side difference in range of motion was 2° ± 3° for extension and 2° ± 5° for flexion. Sixty-five percent of patients had a normal Lachman test result, and 33% were nearly normal. For the pivot-shift test findings, 94% were normal, and 6% were nearly normal. The average side-to-side difference in the KT-2000 arthrometer test was 1.0 ± 2.3 mm. There were 8 graft failures, 7 of which had subsequent revision surgery. No patients reported pain, swelling, or instability during activities of daily living, and 73% to 78% had no symptoms during very strenuous or strenuous sports activities. The scores of the International Knee Documentation Committee Subjective Knee Form, Activities of Daily Living, and Sports Activity Scores of the Knee Outcome Survey were 85.0, 91.8, and 87.0, respectively, and were similar compared with patients undergoing single-bundle anterior cruciate ligament reconstruction, which we have previously reported. Fifty-one percent described their current activity level as normal, and 35% reported it as nearly normal. Conclusion Anatomic double-bundle anterior cruciate ligament reconstruction results in good restoration of joint stability and patient-reported outcomes when evaluated 2 years after surgery.

Use of the International Knee Documentation Committee guidelines to assess outcome following anterior cruciate ligament reconstruction.

Abstract The purpose of this project was to determine if guidelines established by the International Knee Documentation Committee (IKDC) could distinguish differences in outcome, as indicated by the patients’ subjective rating of knee function following ACL reconstruction, and to determine if all subgroups included in the IKDC rating system contribute to the prediction of the overall final IKDC rating. A total of 133 patients undergoing ACL reconstruction were evaluated according to IKDC guidelines 1–5 years postoperatively. Each subject was rated in each of four subgroups on the IKDC scale: patient subjective assessment, symptoms, range of motion (ROM), and laxity. The worst rating for the subgroups defined the overall final rating. The outcome from the patient’s perspective was determined by asking them to rate the function of their knee on a scale from 0 to 100 with 100 being the level of function before injury. Average length of follow-up was 3.2 years (range 1.1– 6.3 years). ANOVA indicated that the patients’ subjective rating of knee function on a scale from 0 to 100 differed according to the overall final IKDC rating (F = 16.1, P < 0.001). The average subjective rating of knee function for those with a normal IKDC rating was 95.2, nearly normal was 91.2, abnormal was 84.9, and severely abnormal was 75.4. The average subjective rating of knee function for those who were severely abnormal was significantly different from those rated normal, nearly normal, and abnormal, and the average subjective rating for those who were abnormal was significantly different from those who were normal or nearly normal. There was no significant difference in average subjective rating between those who were rated as normal or nearly normal. Regression analysis indicated that all four subgroups contributed significantly to the prediction of the final IKDC rating (r2 = 0.70), but the majority of the variance (62%) was accounted for by symptoms and laxity. These results appear to indicate that the IKDC guidelines are useful for describing the outcome following ACL reconstruction. Further testing of the IKDC guidelines is necessary to determine if they are capable of detecting a change in the patients over time following treatment and/or surgery of the knee.

Allograft versus autograft anterior cruciate ligament reconstruction : 3- to 5-year outcome

Sixty-four patients whose knees underwent anterior cruciate ligament reconstruction with nonirradiated allograft tissue were compared with 26 patients whose anterior cruciate ligaments were reconstructed using autograft tissue 3 to 5 years after their operation. Detailed symptoms, activity-level, and functional outcomes, physical examination, and instrumented knee testing were recorded. No statistically significant differences were found except a higher incidence of loss of terminal extension in the autograft group. These differences were small and not considered clinically significant. Laxity and knee scores were similar in both groups. According to International Knee Documentation Committee ratings, overall outcome was normal or nearly normal in 48% of the allograft patients and in 38% of the autograft patients. Overall subjective rating with the Cincinnati Knee Score was 85.8 for the allograft patients and 84.5 for the autograft patients. Allograft tissue provides an acceptable alternative to autograft tissue for reconstruction of the anterior cruciate ligament.

Responsiveness of the International Knee Documentation Committee Subjective Knee Form

Background and Purpose The International Knee Documentation Committee Subjective Knee Form was developed to measure change in symptoms, function, and sports activity in patients treated for a variety of knee conditions. Although previous research has demonstrated reliability and validity of the form, its responsiveness has not been evaluated. The purpose of this study was to determine responsiveness of the International Knee Documentation Committee Subjective Knee Form. Study Design Cohort study (diagnosis); Level of evidence, 1. Methods Patients who participated in the original validation study for the International Knee Documentation Committee Subjective Knee Form completed the form and a 7-level global rating of change scale that ranged from greatly worse to greatly better after a mean of 1.6 years (range, 0.5-2.3 years). Analyses included calculation of the standardized response mean and mean change in International Knee Documentation Committee Subjective Knee Form score compared to the patients perception of change on the global rating of change scale. In addition, a receiver operating characteristic curve was plotted to determine the change in score that best distinguished patients who improved from those who did not. Results The overall standardized response mean was 0.94, which is considered large. With the exception of those who were slightly worse or unchanged, the mean change in the International Knee Documentation Committee Subjective Knee Form score compared to the patients’ perceived global ratings of change was as expected (greatly worse,–15.1; somewhat worse,–8.4; slightly worse, 20.6; no change, 10.7; slightly better, 5.9; somewhat better, 18.1; greatly better, 38.7). The receiver operating characteristic curve analysis revealed that a change score of 11.5 points had the highest sensitivity, and a change score of 20.5 points had the highest specificity to distinguish between those who were or were not improved. Conclusion The International Knee Documentation Committee Subjective Knee Form is a responsive measure of symptoms, function, and sports activity for patients with a variety of knee conditions.

The International Knee Documentation Committee Subjective Knee Evaluation Form Normative Data

Background The International Knee Documentation Committee Subjective Knee Evaluation Form may be used to measure symptoms, function, and sports activity for people with a variety of knee disorders, including ligamentous and meniscal injuries, osteoarthritis, and patellofemoral dysfunction. To date, normative data have not been established for this valid, reliable, and responsive outcomes instrument. Purpose To provide clinicians and researchers with normative data to facilitate the interpretation of results on the International Knee Documentation Committee Subjective Knee Evaluation Form. Study Design Cross-sectional survey. Methods The Subjective Knee Evaluation Form was mailed to 600 people in each of 8 age/gender categories (18-24 years, 25-34 years, 35-50 years, and 51-65 years for both male subjects and female subjects). Participants were drawn from a panel of 550 000 households (1 300 000 subjects) representative of noninstitutionalized persons in the United States and were matched to data from the United States Census Bureau on geographical region, market size, income, and household size. Results Complete data were available for 5246 knees. Twenty-eight percent of respondents reported an injury, weakness, or other problem with one or both knees. Normative data were determined for respondents as a whole and for the subset of respondents with no history of knee problems. Mean scores were determined for men aged 18 to 24 years (89 ± 18), 25 to 34 years (89 ± 16), 35 to 50 years (85 ± 19), and 51 to 55 years (77 ± 23); mean scores were also determined for women aged 18 to 24 years (86 ± 19), 25 to 34 years (86 ± 19), 35 to 50 years (80 ± 23), and 51 to 65 years (71 ± 26). Scores were higher for the subset of respondents with no history of current or prior knee problems. Conclusion Scores on the International Knee Documentation Committee Subjective Knee Evaluation Form vary by age, gender, and history of knee problems. The normative data collected in this article will allow clinicians to interpret how patients with knee injuries are functioning relative to their age-and gender-matched peers and will enable researchers to determine the clinical outcomes of treatment.