Comparison of Clinical and Semiquantitative Cartilage Grading Systems in Predicting Outcomes After Arthroscopic Partial Meniscectomy.

OBJECTIVE. Cartilage loss on preoperative knee MRI is a predictor of poor outcomes after arthroscopic partial meniscectomy. The purpose of this study was to compare the ability to predict outcomes after arthroscopic partial meniscectomy with a clinically used modified Outerbridge system versus a semiquantitative MRI Osteoarthritis Knee Score system for grading cartilage loss. MATERIALS AND METHODS. Patients who underwent preoperative knee MRI within 6 months of arthroscopic partial meniscectomy and who had outcomes available from the time of surgery and 1 year later were eligible for inclusion. Cases were evaluated by two radiologists and one radiology fellow with the use of both grading systems. The accuracy of each system in discriminating between surgical success and failure was estimated using the ROC curve (AUC) with 95% CIs. A Wald test was used to assess noninferiority of the clinical grading system. Interreader agreement regarding the accuracy of the grading systems in predicting outcomes was also compared. RESULTS. A total of 78 patients (38 women and 40 men; mean age, 56.6 years) were included in the study. A prediction model using clinical grading (AUC = 0.695; 95% CI, 0.566-0.824) was noninferior (p = 0.047) to a model using MRI Osteoarthritis Knee Score grading (AUC = 0.683; 95% CI, 0.539-0.827). Both MRI prediction models performed better than a model using demographic characteristics only (AUC = 0.667; 95% CI, 0.522-0.812). Inter-reader agreement with clinical grading (80.8%) was higher than that with MRI Osteoarthritis Knee Score grading (65.0%; p = 0.012). CONCLUSION. A clinically used system to grade cartilage loss on MRI is as effective as a semiquantitative system for predicting outcomes after arthroscopic partial meniscectomy, while also offering improved interreader agreement.

Greater patient confidence yields greater functional outcomes after primary total shoulder arthroplasty.

BACKGROUND: Patient satisfaction is increasingly being tied to reimbursement rates, and patient satisfaction is often associated with improving functionality and decreasing disability postoperatively. This study sought to determine if a total shoulder arthroplasty patient's preoperative confidence in his or her ability to attain the level of activity desired would influence postoperative functional scores. MATERIALS AND METHODS: Patients undergoing a primary total shoulder arthroplasty at a single institution were asked to complete a preoperative questionnaire with multiple items including baseline symptom severity measures and their confidence in reaching their level of desired functionality postoperatively (scored 0-10). Patients then completed an identical postoperative questionnaire at their follow-up visits. Associations between the patient's confidence in attaining treatment goals and functional outcomes was established by multiple linear regression models that were adjusted for gender, age, body mass index, baseline 12-Item Short Form Health Survey mental component scores, college education, smoking status, baseline functional scores, and length of follow-up. RESULTS: Patients had a high level of confidence that their outcome would match their expectations, with an average score of 7.8 (range, 0-10; 28.4% reported a full 10/10 confidence). For every 1-point increase in confidence, patients experienced an average increase in their function score of 2.7 points (P = .039) and improvement in their pain score of 2.0 (P = .033) according to the Penn Shoulder Score. There was no significant association with the patient's 12-Item Short Form Health Survey score postoperatively. CONCLUSIONS: Patients with greater preoperative confidence actually have significantly better postoperative functional outcomes than their less confident peers even with adjustment for other known risk factors.

The Effect of Aspiration and Corticosteroid Injection After ACL Injury on Postoperative Infection Rate.

BACKGROUND: Injecting bioactive substances into the knee is common in orthopaedic practice, and recently it has been shown to mitigate risk factors for posttraumatic osteoarthritis. Therefore, understanding the influence of these injections on postoperative infection rate is imperative. HYPOTHESIS: Postinjury aspiration and corticosteroid injection (CSI) of the knee before anterior cruciate ligament (ACL) reconstruction (ACLR) would not increase the risk of postoperative infection. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: All patients between the ages of 10 and 65 years who underwent primary bone-patellar tendon-bone ACLR by 1 fellowship-trained sports medicine orthopaedic surgeon between January 1, 2011, and September 8, 2020, at 1 of 2 major academic centers were evaluated for inclusion. A total of 693 patients were included, with 273 patients receiving postinjury and preoperative aspiration and CSI. A postoperative infection was defined as a patient returning to the operating room for an intra-articular washout. The intervals-measured in days-between the CSI and ACLR and between ACLR and the final follow-up were recorded. To further evaluate the infection risk in each cohort (total cohort; aspiration and injection cohort; no aspiration and injection cohort), the upper 95% confidence bound for the infection risk was calculated for each cohort. RESULTS: There were no postoperative infections in the 693 patients included in this study. The upper 95% confidence bounds were 0.4%, 1.1%, and 0.7% for the total cohort, the cohort that underwent aspiration and injection, and the cohort that did not, respectively. The median number of days between the surgical date and that of the aspiration and injection was 34 days, and the mean follow-up for the entire cohort was 337.4 days (95% CI, 307.6-367.3). CONCLUSION: Postinjury and preoperative aspiration and CSI is a safe intervention that can be used before ACLR. Future studies with larger sample sizes, longer patient follow-ups, and multiple surgeons would be helpful to both better understand infection risk and better identify the influence of CSI on preventing posttraumatic osteoarthritis.

Do Patellar Tendon Repairs Have Better Outcomes than Quadriceps Tendon Repairs? A Prospective Cohort Analysis.

Patellar tendon (PT) and quadriceps tendon (QT) ruptures represent significant injuries and warrant surgical intervention in most patients. Outcome data are predominantly retrospective analyses with low sample sizes. There are also minimal data comparing QT and PT repairs and the variables impacting patient outcomes. The level of evidence of the study is level II (prognosis). From the prospective OME cohort, 189 PT or QT repairs were performed between February 2015 and October 2019. Of these, 178 were successfully enrolled (94.2%) with 1-year follow-up on 141 (79.2%). Baseline demographic data included age, sex, race, BMI, years of education, smoking status, and baseline VR-12 MCS score. Surgical and follow-up data included surgeon volume, fixation technique, baseline, and 1-year Knee Injury and Osteoarthritis Outcome Score-Pain (KOOS-Pain), Knee Injury and Osteoarthritis Outcome Score-Physical Function (KOOS-PS), and 1-year Patient Acceptable Symptom State (PASS) scores and complications. Multivariable regression analysis was utilized to identify prognosis and significant risk factors for outcomes-specifically, whether KOOS-Pain or KOOS-PS were different between QT versus PT repairs. There were 59 patients in the PT cohort and 82 patients in QT cohort. Baseline demographic data demonstrated that PT cohort was younger (45.1 vs. 59.5 years, p <0.001), included significantly fewer patients of White race (51.7 vs. 80.0%, p = 0.001), lesser number of years of education (13.9 vs. 15.2 years, p = 0.020), a higher percentage of "high" surgeon volume (72.9% vs. 43.9%, p = 0.001) and 25.4% of PT repairs had supplemental fixation (QT had zero, p <0.001). Multivariable analysis identified gender (female-worse, p = 0.001), years of education (higher-better, p = 0.02), and baseline KOOS-Pain score (higher-better, p <0.001) as the risk factors that significantly predicted KOOS-Pain score. The risk factors that significantly predicted KOOS-PS were gender (female worse, p = 0.033), race (non-White-worse, p <0.001), baseline VR-12 MCS score (higher-better, p <0.001), and baseline KOOS-PS score (higher better, p = 0.029). KOOS-Pain and KOOS-PS scores improved after both QT and PT repairs. Patient reported pain and function at 1 year were similar between PT and QT repairs after adjusting for known risk factors. Multivariable analysis identified female gender and low baseline KOOS scores as predictors for worse outcomes.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.

A Last-Ditch Effort and Personalized Surgeon Letter Improves PROMs Follow-Up Rate in Sports Medicine Patients: A Crossover Randomized Controlled Trial.

Patient-reported outcomes measures (PROMs) are important for the advancement of orthopaedic surgeries. The primary difficulty while collecting PROMs is obtaining adequate follow-up rates. Therefore, it is important to find methods to improve follow-up, especially in patients who have failed to respond to initial attempts. We hypothesized that PROMs follow-up could be effectively increased by sending a salvage-effort personalized surgeon letter to sports medicine patients who failed to respond to initial (centralized electronic, mail, and/or phone contacts) PROMs collection 1 year after surgery. Patients who failed to respond to 1-year follow-up of postoperative PROMs collection at our outpatient sports medicine surgery center were included. Patients were randomized into an intervention or control group. Patients in the intervention group were mailed PROMs form and an Institutional Review Board-approved letter that was personalized with surgical information, surgeon picture, and surgeon signature. Control group was mailed the same letter a month later. Chi-squared analysis was conducted at 5 weeks. Out of 843 surgeries, our initial 1-year PROMs follow-up rate was 65%, which allowed for 292 patients to be eligible for our study. After exclusions, 281 patients (randomized to 140 control group and 141 intervention group) were included in our study. We found a 20% response rate in the intervention group with 28 patients returning PROMs as compared with a 1.4% rate in the control group with two patients returning PROMs. The odds ratio was 17.1 (95% confidence interval: 4-73.3; p < 0.0001). A salvage-effort personalized surgeon letter is an efficient and relatively cost-effective method to increase PROMs follow-up rate, which means that a personalized surgeon letter can reach and engage patients who would otherwise be considered lost to follow-up, allowing for better outcomes monitoring after surgery.

Do Narcotic Use, Physical Therapy Location, or Payer Type Predict Patient-Reported Outcomes After Anterior Cruciate Ligament Reconstruction?

BACKGROUND: Opioid use and public insurance have been correlated with worse outcomes in a number of orthopaedic surgeries. These factors have not been investigated with anterior cruciate ligament reconstruction (ACLR). PURPOSE/HYPOTHESIS: To evaluate if narcotic use, physical therapy location, and insurance type are predictors of patient-reported outcomes after ACLR. It was hypothesized that at 1 year postsurgically, increased postoperative narcotic use would be associated with worse outcomes, physical therapy obtained within the authors' integrated health care system would lead to better outcomes, and public insurance would lead to worse outcomes and athletic activity. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: All patients undergoing unilateral, primary ACLR between January 2015 and February 2016 at a large health system were enrolled in a standard-of-care prospective cohort. Knee injury and Osteoarthritis Score (KOOS) and the Hospital for Special Surgery Pediatric-Functional Activity Brief Scale (HSS Pedi-FABS) were collected before surgery and at 1 year postoperatively. Concomitant knee pathology was assessed arthroscopically and electronically captured. Patient records were analyzed to determine physical therapy location, insurance status, and narcotic use. Multivariable regression analyses were used to identify significant predictors of the KOOS and HSS Pedi-FABS score. RESULTS: A total of 258 patients were included in the analysis (mean age, 25.8; 51.2% women). In multivariable regression analysis, narcotic use, physical therapy location, and insurance type were not independent predictors of any KOOS subscales. Public insurance was associated with a lower HSS Pedi-FABS score (-4.551, P = .047) in multivariable analysis. Narcotic use or physical therapy location was not associated with the HSS Pedi-FABS score. CONCLUSION: Increased narcotic use surrounding surgery, physical therapy location within the authors' health care system, and public versus private insurance were not associated with disease-specific KOOS subscale scores. Patients with public insurance had worse HSS Pedi-FABS activity scores compared with patients with private insurance, but neither narcotic use nor physical therapy location was associated with activity scores. Physical therapy location did not influence outcomes, suggesting that patients be given a choice in the location they received physical therapy (as long as a standardized protocol is followed) to maximize compliance.

What Are the Predictors of Poor Patient-Reported Outcomes After Shoulder Instability Surgery?

BACKGROUND: Prospectively collected responses to Patient Acceptable Symptom State (PASS) questions after shoulder instability surgery are limited. Responses to these outcome measures are imperative to understanding their clinical utility. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate which factors predict unfavorable patient-reported outcomes after shoulder instability surgery, including "no" to the PASS question. We hypothesized that poor outcomes would be associated with male adolescents, bone loss, combined labral tears, and articular cartilage injuries. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients aged ≥13 years undergoing shoulder instability surgery were included in point-of-care data collection at a single institution across 12 surgeons between 2015 and 2017. Patients with anterior-inferior labral tears were included, and those with previous ipsilateral shoulder surgery were excluded. Demographics, American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores, and surgical findings were obtained at baseline. ASES and SANE scores, PASS responses, and early revision surgery rates were obtained at a minimum of 1 year after the surgical intervention. Regression analyses were performed. RESULTS: A total of 234 patients met inclusion criteria, of which 176 completed follow-up responses (75.2%). Nonresponders had a younger age, greater frequency of glenoid bone loss, fewer combined tears, and more articular cartilage injuries (P < .05). Responders' mean age was 25.1 years, and 22.2% were female. Early revision surgery occurred in 3.4% of these patients, and 76.1% responded yes to the PASS question. A yes response correlated with a mean 25-point improvement in the ASES score and a 40-point improvement in the SANE score. On multivariate analysis, combined labral tears (anterior-inferior plus superior or posterior tears) were associated with greater odds of responding no to the PASS question, while both combined tears and injured capsules were associated with lower ASES and SANE scores (P < .05). Sex, bone loss, and grade 3 to 4 articular cartilage injuries were not associated with variations on any patient-reported outcome measure. CONCLUSION: Patients largely approved of their symptom state at ≥1 year after shoulder instability surgery. A response of yes to the PASS question was given by 76.1% of patients and was correlated with clinically and statistically significant improvements in ASES and SANE scores. Combined labral tears and injured capsules were negative prognosticators across patient-reported outcome measures, whereas sex, bone loss, and cartilage injuries were not.

Associations of Preoperative Patient Mental Health and Sociodemographic and Clinical Characteristics With Baseline Pain, Function, and Satisfaction in Patients Undergoing Rotator Cuff Repairs.

BACKGROUND: Shoulder pain and dysfunction are common indications for rotator cuff repair surgery, yet the factors that are associated with these symptoms are not fully understood. PURPOSE/HYPOTHESIS: This study aimed to investigate the associations of patient and disease-specific factors with baseline patient-reported outcome measures (PROMs) in patients undergoing rotator cuff repair. We hypothesized that tear size and mental health status, as assessed by the Veterans RAND 12-Item Health Survey mental component score (VR-12 MCS), would be associated with baseline total Penn Shoulder Score (PSS) and its pain, function, and satisfaction subscale scores. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We prospectively identified 12 patient factors and 12 disease-specific factors as possible statistical predictors for baseline PROMs in patients undergoing surgical repair of superior-posterior rotator cuff tears at a single institution over a 3-year period. Multivariable statistical modeling and Akaike information criterion comparisons were used to investigate the unique associations with, and relative importance of, these factors in accounting for variation in baseline PSS and its subscale scores. RESULTS: A total of 1442 patients who had undergone surgery by 23 surgeons met inclusion criteria, with a baseline median total PSS of 38.5 (pain, 12; function, 24.2; satisfaction, 2). Adjusted R2 in multivariable models demonstrated that the 24 general patient and disease-specific factors accounted for 22% to 24% of the variability in total PSS and its pain and function subscale scores. Large/massive tear size was significantly associated with worse PSS total score and function score but not pain or satisfaction scores. Lower VR-12 MCS was significantly associated with worse total PSS and all 3 subscale scores. Among other factors significantly associated with baseline PROMs were sex, race, preoperative opioid use, years of education, employment status, acromion status, and adhesive capsulitis. Lower VR-12 MCS, preoperative opioid use, female sex, and black race were the factors most strongly associated with baseline PROMs. CONCLUSION: Large/massive tear size, lower VR-12 MCS, and several additional patient and disease-specific factors are associated with baseline PROMs in patients undergoing rotator cuff repair. Further studies are needed to investigate whether these factors will also predict poor postoperative PROMs.

Comparison of Standard and Right/Left International Knee Documentation Committee Subjective Knee Form Scores.

BACKGROUND: The International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) is a validated patient-reported outcome used in clinical research. No studies exist directly comparing the standard unilateral adult version (IKDC-SKF) with the bilateral adult version (R/L IKDC-SKF). HYPOTHESES: The first hypothesis is that no clinically relevant difference would be observed between standard IKDC-SKF scores and involved R/L scores. The second hypothesis is that a relevant difference would be observed between involved and uninvolved scores on the R/L IKDC-SKF. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 2. METHODS: One hundred patients were enrolled via a crossover study design. Participants were split into 2 groups per simple randomization. One group completed the standard IKDC-SKF first and the R/L IKDC-SKF second. The other group completed forms in the reverse order. A 10-minute washout period was administered between questionnaires. Participants reported their preferred form in a postquestionnaire survey. A 5-point threshold for clinical relevance was set a priori, which is less than multiple published minimal detectable change and minimal clinically important difference metrics of the standard IKDC-SKF, ranging from 6.3 to 20.5. Data were analyzed with Bland-Altman plots, paired t tests, correlations, and chi-square tests. RESULTS: Paired t tests between the standard IKDC-SKF and the involved R/L IKDC-SKF scores demonstrated a statistically significant mean difference of 1.4 ( P = .008; 95% CI, 0.4-2.4). However, the 95% CI falls under the clinically relevant threshold of 5. Standard and involved knee scores from the R/L IKDC-SKF were highly correlated, with a rho of 0.95. Patients consistently distinguished the injured knee from the uninjured knee across a range of scores via the R/L IKDC-SKF ( P < .001). The postquestionnaire survey showed that 55 patients preferred the R/L IKDC-SKF, 30 preferred the standard IKDC-SKF, and 15 had no preference. Post hoc analysis showed a significant preference for "R/L vs standard IKDC-SKF" ( P = .014) and "R/L IKDC-SKF vs no preference" ( P < .003). CONCLUSION: No clinically relevant difference was observed between the standard IKDC-SKF and the involved knee score of the R/L IKDC-SKF. Therefore, for symptomatic unilateral knee diagnosis, either form can be used. The R/L IKDC-SKF showed a consistent and clinically relevant difference between involved and uninvolved knees. Patients in this study preferred the R/L IKDC-SKF.

Predictors of Hip Pain and Function in Femoroacetabular Impingement: A Prospective Cohort Analysis.

BACKGROUND: Validated patient-reported outcome measures (PROMs) of hip pain and function at the time of arthroscopy could be predictors of the final outcome. Little is known about how patient factors or pathologic intra-articular findings relate to hip pain or function at the time of surgery for those presenting with femoroacetabular impingement (FAI). PURPOSE: To evaluate all patient and operative factors that contribute to hip pain and dysfunction in patients with FAI. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A prospective cohort of patients undergoing hip arthroscopy for FAI were electronically enrolled between February 2015 and September 2016. Baseline PROMs were collected, including Hip disability and Osteoarthritis Outcome Score (HOOS) for pain, HOOS-Physical Function Shortform (HOOS-PS), Veterans RAND 12-Item Health Survey (VR-12), and University of California-Los Angeles (UCLA) Activity Score. Surgeons documented intra-articular operative findings and treatment. Multivariable linear regression models were created for continuous scores of HOOS pain, HOOS-PS, and VR-12 Physical Component Score as outcome measures. Risk factors included patient characteristics and intraoperative anatomic and pathologic findings. RESULTS: During the study period, 396 patients underwent arthroscopic hip procedures, and 373 (94%) completed preoperative PROMs; 331 patients were undergoing arthroscopic surgery for FAI. The mean patient age was 32.91 ± 12.49 years, mean body mass index was 26.22 ± 4.92 kg/m2, and 71% were female. Multivariate analyses demonstrated female sex, lower education levels, smoking, lower mental health scores, and lower activity-level scores predicted HOOS pain preoperatively. According to multivariate analysis, patient factors associated with worse baseline HOOS-PS include smoking, additional years of education, lower mental health, and activity scores. Lower baseline VR-12 functional scores were predicted by female sex, elevated body mass index, smoking, and lower activity levels. For all baseline PROMs, there was no instance where an arthroscopic variable or pathologic finding proved statistically significant after the important patient covariates were controlled for. CONCLUSION: Patient factors, including mental health, activity level, sex, and smoking, are more predictive of baseline hip pain (as measured by HOOS) and function than are intra-articular findings (eg, status of the labrum or articular cartilage) during hip arthroscopy for FAI. Future studies evaluating patient outcomes after surgery for FAI should consider adjusting for these identified patient factors to accurately interpret the effect of treatment on patient-reported outcomes after surgery.

No Clinically Significant Difference Between Adult and Pediatric IKDC Subjective Knee Evaluation Scores in Adults.

BACKGROUND: Two versions of the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation form currently exist: the original version (1999) and a recently modified pediatric-specific version (2011). Comparison of the pediatric IKDC with the adult version in the adult population may reveal that either version could be used longitudinally. HYPOTHESIS: We hypothesize that the scores for the adult IKDC and pediatric IKDC will not be clinically different among adult patients aged 18 to 50 years. STUDY DESIGN: Randomized crossover study design. LEVEL OF EVIDENCE: Level 2. METHODS: The study consisted of 100 participants, aged 18 to 50 years, who presented to orthopaedic outpatient clinics with knee problems. All participants completed both adult and pediatric versions of the IKDC in random order with a 10-minute break in between. We used a paired t test to test for a difference between the scores and a Welch's 2-sample t test to test for equivalence. A least-squares regression model was used to model adult scores as a function of pediatric scores, and vice versa. RESULTS: A paired t test revealed a statistically significant 1.6-point difference between the mean adult and pediatric scores. However, the 95% confidence interval (0.54-2.66) for this difference did not exceed our a priori threshold of 5 points, indicating that this difference was not clinically important. Equivalence testing with an equivalence region of 5 points further supported this finding. The adult and pediatric scores had a linear relationship and were highly correlated with an R2 of 92.6%. CONCLUSION: There is no clinically relevant difference between the scores of the adult and pediatric IKDC forms in adults, aged 18 to 50 years, with knee conditions. CLINICAL RELEVANCE: Either form, adult or pediatric, of the IKDC can be used in this population for longitudinal studies. If the pediatric version is administered in adolescence, it can be used for follow-up into adulthood.

Statistical comparison of the pediatric versus adult IKDC subjective knee evaluation form in adolescents.

BACKGROUND: The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form is a patient-reported outcome with adult (1998) and pediatric (2011) versions validated at different ages. Prior longitudinal studies of patients aged 13 to 17 years who tore their anterior cruciate ligament (ACL) have used the only available adult IKDC, whereas currently the pediatric IKDC is the accepted form of choice. PURPOSE/HYPOTHESIS: This study compared the adult and pediatric IKDC forms and tested whether the differences were clinically significant. The hypothesis was that the pediatric and adult IKDC questionnaires would show no clinically significant differences in score when completed by patients aged 13 to 17 years. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 100 participants aged 13 to 17 years with knee injuries were split into 2 groups by use of simple randomization. One group answered the adult IKDC form first and then the pediatric form. The second group answered the pediatric IKDC form first and then the adult form. A 10-minute break was given between form administrations to prevent rote repetition of answers. Study design was based on established methods to compare 2 forms of patient-reported outcomes. A 5-point threshold for clinical significance was set below previously published minimum clinically important differences for the adult IKDC. Paired t tests were used to test both differences and equivalence between scores. By ordinary least-squares models, scores were modeled to predict adult scores given certain pediatric scores and vice versa. RESULTS: Comparison between adult and pediatric IKDC scores showed a statistically significant difference of 1.5 points; however, the 95% CI (0.3-2.6) fell below the threshold of 5 points set for clinical significance. Further equivalence testing showed the 95% CI (0.5-2.4) between adult and pediatric scores being within the defined 5-point equivalence region. The scores were highly correlated, with a linear relationship (R(2) = 92%). CONCLUSION: There was no clinically significant difference between the pediatric and adult IKDC form scores in adolescents aged 13 to 17 years. This result allows use of whichever form is most practical for long-term tracking of patients. A simple linear equation can convert one form into the other. If the adult questionnaire is used at this age, it can be consistently used during follow-up.