Reliability, validity, and responsiveness of four knee outcome scales for athletic patients

Walking gait asymmetries 6 months following anterior cruciate ligament reconstruction predict 12-month patient-reported outcomes

The study sought to determine the association between gait biomechanics (vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR]) collected 6 months following anterior cruciate ligament reconstruction (ACLR) with patient-reported outcomes at 12 months following ACLR. Walking gait biomechanics and all subsections of the Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected at 6 and 12 months following ACLR, respectively, in 25 individuals with a unilateral ACLR. Peak vGRF and peak instantaneous vGRF-LR were extracted from the first 50% of the stance phase. Limb symmetry indices (LSI) were used to normalize outcomes in the ACLR limb to that of the uninjured limb (ACLR/uninjured). Linear regression analyses were used to determine associations between biomechanical outcomes and KOOS while accounting for walking speed. Receiver operator characteristic curves were used to determine the accuracy of 6-month biomechanical outcomes for identifying individuals with acceptable patient-reported outcomes, using previously defined KOOS cut-off scores, 12 months post-ACLR. Individuals with lower peak vGRF LSI 6 months post-ACLR demonstrated worse patient-reported outcomes (KOOS Pain, Activities of Daily life, Sport and Recreation, Quality of Life) at the 12-month exam. A peak vGRF LSI ≥0.99 6 months following ACLR associated with 13.33× higher odds of reporting acceptable patient-reported outcomes 12 months post-ACLR. Lesser peak vGRF LSI during walking at 6-months post-ACLR may be a critical indicator of worse future patient-reported outcomes. Clinical significance achieving early symmetrical lower extremity loading and minimizing under-loading of the ACLR limb during walking may be a potential therapeutic target for improving patient-reported outcomes post-ACLR. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2932-2940, 2018.

Dance Functional Outcome Survey: Development and Preliminary Analyses

The Dance Functional Outcome Survey (DFOS) was developed as a self-report questionnaire for healthy and injured ballet and modern dancers, focusing on the low back and lower extremities. Our aim was to determine factor analysis and internal consistency of the 16 items and to investigate test-retest and equivalence reliability and validity of the DFOS compared to three orthopedic outcomes instruments. Data were collected from 80 healthy and injured adult ballet and modern pre-professional and professional dancers. DFOS Likert-type and visual analog scales were completed twice within 4-9 days to study test-retest reliability. The Cincinnati Knee Rating System, Olerud and Molander Foot-Ankle Questionnaire, and Oswestry Disability Index were used to assess concurrent validity using intraclass correlation coefficients in SPSS, p<0.05. To determine instrument dimensions and internal consistency of the items, we conducted exploratory factor analysis and calculated Cronbach's α in JASP. DFOS demonstrated single factor loading and high Cronbach's α; high test-retest repeatability and equivalence reliability ( r =0.74-0.99) and acceptable criterion validity compared to the orthopedic outcomes instruments (r≥0.67). These results support further study of a revised 14 item Likert-version DFOS for repeatability, validity and responsiveness.

Graft-Recipient Anteroposterior Mismatch Does Not Affect the Midterm Clinical Outcomes of Osteochondral Allograft Transplantation of the Femoral Condyle

BACKGROUND

For the treatment of femoral condyle cartilage defects with osteochondral allograft transplantation (OCA), many surgeons have relaxed their graft-recipient size-matching criteria given the limited allograft supply. However, since the anteroposterior (AP) length is typically correlated with the radius of curvature for a given condyle, a large mismatch in graft-recipient AP length can indicate a corresponding mismatch in the radius of curvature, leading to articular incongruity after implantation.

PURPOSE

To evaluate the association between femoral condyle graft-recipient AP mismatch and clinical outcomes of OCA.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective review was conducted of patients treated with OCA for femoral condyle chondral defects from 2000 to 2015. Graft characteristics, including AP and mediolateral dimensions, were gathered from vendor-specific allograft offering documents. Patient condyle dimensions were measured on preoperative magnetic resonance imaging. Reoperations and patient responses to validated outcome measures were reviewed. Failure was defined by any partial removal/revision of the allograft or conversion to knee arthroplasty. A multivariable logistic regression model was fitted to examine the association of AP mismatch with OCA failure while adjusting for patient age and number of previous ipsilateral knee surgical procedures.

RESULTS

A total of 69 knees from 69 patients (mean age, 35.7 years; 71% male) met the inclusion criteria. Mean duration of follow-up was 4 years (range, 2-16 years). The mean absolute graft-recipient AP mismatch was 6.7 mm (range, 0-20 mm; P < .01). At final follow-up, 19 knees had failed. There was no significant difference in the mean absolute AP mismatch between failures (8.1 mm) and nonfailures (6.2 mm; P = .17). Multivariate logistic regression revealed that AP mismatch was not associated with graft failure ( P = .14). At final follow-up, significant improvements were noted in the 36-Item Short Form Health Survey, International Knee Documentation Committee subjective form, and Knee Outcome Survey-Activities of Daily Living ( P < .01 for all). Magnitude of AP mismatch was not associated with postoperative outcome scores or achievement of minimal clinically significant differences in outcome scores.

CONCLUSION

Magnitude of graft-recipient AP mismatch was not associated with midterm OCA failure rates or patient-reported outcome scores, suggesting that AP length mismatch within the limits measured here is not a contraindication for graft acceptance.

Polish Cross-Cultural Adaptation and Validation of the Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS) in Patients Undergoing Total Knee Arthroplasty

Background

The Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS) is a self-reported questionnaire used for the evaluation of the overall health of patients with knee dysfunctions. The purpose of this study was to perform a cross-cultural adaptation of the Polish version of KOS-ADLS and to evaluate its psychometric properties in patients at the end-stage of knee osteoarthritis who were qualified for a total knee replacement (TKR).

Material/Methods

Seventy patients consecutively qualified for surgical TKR procedure participated in this study. To adapt the KOS-ADLS, the following scales and reference tests were used: Knee injury and Osteoarthritis Outcome Score (KOOS), Visual Analogue Scale (VAS), Time Up and Go test (TUG), and Five Times Sit to Stand test (5×STS). The studies were conducted 3 times: 2 weeks before surgery (first study), 6 to 13 days later (retest), and 6 months after surgery.

Results

The Polish version of KOS-ADLS showed excellent reliability (ICC=0.89 SEM=2.68, MDC=7.43) and high responsiveness (ES=4.76, SRM=3.18). The internal consistency was poor in the first assessment (Cronbach’s alpha=0.68), but acceptable in the post-surgery evaluation (Cronbach’s alpha=0.86). There were fair and moderate correlations found between KOS-ADLS and VAS scales in the first examination, TUG, and 5×STS. Stronger correlations were observed between the results obtained in KOS-ADLS and KOOS.

Conclusions

The Polish version of the KOS-ADLS demonstrated good reliability, validity, and responsiveness for use in patients who have undergone TKR surgery.

Validation of a Composite Test for Assessment of Readiness for Return to Sports After Anterior Cruciate Ligament Reconstruction: The K-STARTS Test

Background:

There is limited information on the appropriate timing of return to sports after anterior cruciate ligament (ACL) reconstruction. A composite test was developed to assess the athlete’s ability to return to sports after ACL reconstruction: the Knee Santy Athletic Return To Sport (K-STARTS) test.

Hypothesis:

The K-STARTS test meets validation criteria for an outcome score assessing readiness for return to sports after ACL reconstruction.

Study Design:

Diagnostic study.

Level of Evidence:

Level 3.

Methods:

A prospective comparative study identified 410 participants: 371 participants who had undergone ACL reconstruction and a control group of 39 healthy participants. The K-STARTS score is calculated as the sum of 7 tests (8 components), for a maximal value of 21 points. Construct validity, internal consistency, discriminant validity, and sensitivity to change were used to validate this new test.

Results:

The K-STARTS assessment showed a high completion rate (100%), high reproducibility (intraclass correlation coefficient, 0.87; coefficient of variation, 7.8%), and high sensitivity to change. There was moderate correlation with the ACL Return to Sports after Injury scale (ACL-RSI) and hop tests. There were no ceiling or floor effects. There was a significant difference between K-STARTS scores assessed at 6 and 8 months postoperatively (11.2 ± 2.7 vs 17.1 ± 3.2; P < 0.001). The K-STARTS score in the control group was significantly higher than that in the ACL reconstruction group (17.3 ± 2.1 and 13.7 ± 3.8, respectively; P < 0.001).

Conclusion:

The K-STARTS test is an objective outcome measure for functional improvement after ACL reconstruction.

Clinical Relevance:

It is important for the clinician to determine when return to sports is optimal after ACL reconstruction to reduce the current high risk of reinjury.

Relationship Between Lower-Extremity Strength and Subjective Function in Individuals With Patellofemoral Pain

Objective: Evaluate the relationship between subjective knee function and lower-extremity strength in individuals with patellofemoral pain (PFP). Design: Cohort. Setting: Laboratory. Participants: Participants were 30 individuals with PFP (20 females and 10 males; 76.02 [17.88] kg, 173.04 [7.58] cm, and 24.9 [7] y). Main Outcome Measures: Subjects completed the Activities of Daily Living Scale (ADLS) and had lower-extremity hip and knee isometric strength assessed. Strength was compared between low and high subjective functioning ADLS groups. Correlations for strength and subjective function were assessed, with a linear regression utilized to determine if strength predicted subjective function. Results: Quadriceps strength was significantly greater in the high subjective function group (38.5 [13.9] percent body mass) than in the low subjective function group (27.88 [8.96] percent body mass, P = .02). Significant correlations were seen between the ADLS and all 5 lower-extremity strength measures (r = .376–.535). Quadriceps strength was a strong predictor of subjective function in those with PFP, explaining 28.6% of the total variance in the ADLS. Conclusions: Quadriceps strength was a strong predictor of subjective function when assessed by the ADLS in patients with PFP and significantly greater in those with higher subjective function. A strong relationship exists between self-reported function and lower-extremity strength, suggesting the need to evaluate and treat lower-extremity weakness.

Measuring Quality and Outcomes in Sports Medicine

Patient-reported outcome measures (PROMs) are objective metrics critical to evaluating outcomes throughout orthopedic surgery. New instruments continue to emerge, increasing the breadth of information required for those intending to use these measures for research or clinical care. Although earlier metrics were developed using the principles of classic test theory, newer instruments constructed using item response theory are amenable to computer-adaptive testing and may change the way these instruments are administered. This article aims to define the psychometric properties that are important to understand when using all PROMs and to review the most widely used instruments in sports medicine.

Functional and Patient-Reported Outcomes Improve Over the Course of Rehabilitation: A Secondary Analysis of the ACL-SPORTS Trial

BACKGROUND

The Anterior Cruciate Ligament-Specialized Post-Operative Return to Sports (ACL-SPORTS) randomized controlled trial was designed to address deficits in functional and patient-reported outcomes. The trial examined the effects of a secondary ACL prevention program that included progressive strengthening, agility training, plyometrics (SAP), and other components of current primary prevention protocols, with perturbation training (SAP + PERT group) and without PERT (SAP group). A secondary purpose of this study was to examine whether study outcomes differed between men and women.

HYPOTHESES

(1) Athletes in both the SAP and SAP + PERT groups will have improved knee function and patient-reported outcome measures from pre- to posttraining, (2) the SAP + PERT group would have higher outcome scores than the SAP group, and (3) outcomes will differ by sex.

STUDY DESIGN

Randomized controlled trial (NCT01773317).

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 79 athletes (39 women) were randomized into the SAP and SAP + PERT groups. All athletes had undergone primary ACL reconstruction and achieved 80% quadriceps strength limb symmetry (QI), full range of motion, had minimal effusion, and had no pain. Additionally, all had begun running again. Prior to and after the training program, athletes' QI, hopping, and patient-reported outcomes were assessed. Repeated-measures analyses of variance were used to determine whether there were differences between groups. Subsequently, the SAP and SAP + PERT groups were collapsed to analyze differences between sexes.

RESULTS

There were significant increases for all variables, with the exception of QI. There were no differences between the SAP and SAP + PERT groups. Both men and women made significant improvements in all knee function and patient-reported outcome measures except QI. Men made significant improvements in QI, whereas women did not.

CONCLUSION

The common elements of the training program that all athletes received (10 sessions of progressive strengthening, agility training, plyometrics, and secondary prevention) may be a beneficial addition to the return-to-sport phase of ACL reconstruction rehabilitation. The results suggest that women may require further quadriceps strengthening to maintain and improve QI, an important focus given the relationship between QI and risk for reinjury.

CLINICAL RELEVANCE

During the return-to-sport phase of ACL reconstruction rehabilitation, clinicians tend to shift their focus away from strengthening toward more advanced sports-related tasks. These results indicate that women in particular need continued focus on quadriceps strengthening.

Restoring physical function after knee replacement: a cross sectional comparison of progressive strengthening vs standard physical therapy

Objective: The purpose of this study is to compare the functional status of patients 12 months after total knee arthroplasty (TKA) who underwent progressive strengthening or standard of care rehabilitation to older adults without knee joint pain. Methods: This cross-sectional design study included 165 participants in the progressive strengthening group, 40 participants in the standard of care group, and 88 older adults (control group). The Knee Outcome Survey - Activity of Daily Living, knee active range of motion (ROM), quadriceps strength, and performance tests were compared between groups using a one-way ANOVA. The proportions of participants in both TKA groups who achieved the lower bound of the 95% confidence interval of the control group were compared using a Fisher's exact test. Results: Significant between-group effects were found for all variables (p < 0.001). The control group had better outcomes than both the progressive strengthening and standard of care groups (p < 0.001). Compared to the standard of care group, a higher proportion of participants in the progressive strengthening group achieved the lower bound cutoff for active knee extension ROM (p = 0.042), quadriceps strength (p = 0.032), and stair climbing time (p = 0.029). Conclusion: More participants in the progressive strengthening group had physical function that was similar to the healthy control group, when compared to the standard of care group. Progressive strengthening rehabilitation may be more effective in restoring normative levels of function after TKA than standard of care.

Performance of the PROMIS in Patients After Anterior Cruciate Ligament Reconstruction

Background

The Patient-Reported Outcomes Measurement Information System (PROMIS) is designed to advance patient-reported outcome (PRO) instruments by utilizing question banks for major health domains.

Purpose

To compare the responsiveness and construct validity of the PROMIS physical function computer adaptive test (PF CAT) with current PRO instruments for patients before and up to 2 years after anterior cruciate ligament (ACL) reconstruction.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

Initially, 157 patients completed the PROMIS PF CAT, Short Form-36 Health Survey (SF-36 physical function [PF] and general health [GH]), Marx Activity Rating Scale (MARS), Knee injury and Osteoarthritis Outcome Score (KOOS activities of daily living [ADL], sport, and quality of life [QOL]), and EuroQol-5 dimensions questionnaire (EQ-5D) at 6 weeks, 6 months, and 2 years after ACL reconstruction. Correlations between instruments, ceiling and floor effects, effect sizes (Cohen d), and standardized response means to describe responsiveness were evaluated. Subgroup analyses compared participants with and without additional arthroscopic procedures using linear mixed models.

Results

At baseline, 6 weeks, and 6 months, the PROMIS PF CAT showed excellent or excellent-good correlations with the SF-36 PF (r = 0.75-0.80, P < .01), KOOS-ADL (r = 0.63-0.70, P < .01), and KOOS-sport (r = 0.32-0.69, P < .01); excellent-good correlation with the EQ-5D (r = 0.60-0.71, P < .01); and good correlation with the KOOS-QOL (r = 0.52-0.58, P < .01). As expected, there were poor correlations with the MARS (r = 0.00-0.24, P < .01) and SF-36 GH (r = 0.16-0.34, P < .01 ). At 2 years, the PROMIS PF CAT showed good to excellent correlations with all PRO instruments (r = 0.42-0.72, P < .01), including the MARS (r = 0.42, P < .01), indicating frequent return to preinjury function. The PROMIS PF CAT had the fewest ceiling or floor effects of all instruments tested, and patients answered, on average, 4 questions. There was no significant difference in baseline physical function scores between subgroups; at follow-up, all groups showed improvements in scores that were not statistically different.

Conclusion

The PROMIS PF CAT is a valid tool to assess outcomes after ACL reconstruction up to 2 years after surgery, demonstrating the highest responsiveness to change with the fewest ceiling and floor effects and a low time burden among all instruments tested. The PROMIS PF CAT is a beneficial alternative for assessing physical function in adults before and after ACL reconstruction.

No difference between mechanical perturbation training with compliant surface and manual perturbation training on knee functional performance after ACL rupture

Manual perturbation training improves dynamic knee stability and functional performance after anterior cruciate ligament rupture (ACL-rupture). However, it is limited to static standing position and does not allow time-specific perturbations at different phase of functional activities. The purpose of this study was to investigate whether administering mechanical perturbation training including compliant surface provides effects similar to manual perturbation training on knee functional measures after an acute ACL-rupture. Sixteen level I/II athletes with ACL-ruptures participated in this preliminary study. Eight patients received mechanical (Mechanical) and eight subjects received manual perturbation training (Manual). All patients completed a functional testing (isometric quadriceps strength, single-legged hop tests) and patient-reported measures (Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), Global Rating Score (GRS), International Knee Documentation Committee 2000 (IKDC 2000) at pre- and post-training. 2 × 2 ANOVA was used for data analysis. No significant group-by-time interactions were found for all measures (p > 0.18). Main effects of time were found for single hop (Pre-testing: 85.14% ± 21.07; Post-testing: 92.49% ± 17.55), triple hop (Pre-testing: 84.64% ± 14.17; Post-testing: 96.64% ± 11.14), KOS-ADLS (Pre-testing: 81.13% ± 11.12; Post-testing: 88.63% ± 12.63), GRS (Pre-testing: 68.63% ± 15.73; Post-testing: 78.81% ± 13.85), and IKDC 2000 (Pre-testing: 66.66% ± 9.85; Post-testing: 76.05% ± 14.62) (p < 0.032). Administering mechanical perturbation training using compliant surfaces induce effects similar to manual perturbation training on knee functional performance after acute ACL-rupture. The clinical significance is both modes of training improve patients' functional-performance and limb-to-limb movement symmetry, and enhancing the patients' self-reported of knee functional measures after ACL rupture. Mechanical perturbation that provides a compliant surface might be utilized as part of the ACL rehabilitation training. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1391-1397, 2018.

Comparison of navigated and conventional high tibial osteotomy for the treatment of osteoarthritic knees with varus deformity: A meta-analysis

BACKGROUND

High tibial osteotomy (HTO) is a usefully surgical procedure to correct the malalignment and delay the progression of osteoarthritis. It is still controversy whether navigation system can offer more accuracy of targeted alignment and achieve better clinical outcomes than conventional method. The purpose of present meta-analysis was to investigate whether navigation system was superior to conventional method with regard to clinical and radiographic outcomes.

METHOD

The included studies compared the clinical and radiographic outcomes between navigated HTO group and conventional group. The clinical assessments were Lysholm Score, AKS Function Score and Arc of motion, and the radiographic outcomes were Mechanical axis (MA), Weight bearing line ratio (WBL), Outliers of alignment and Change in TPS used to evaluate alignment correction. The meta-analysis was performed using Review Manager 5.3 software. Downs and Black and the Newcastle-Ottawa Scale (NOS) were used to evaluate the study quality.

RESULT

Sixteen studies were eligible in present meta-analysis, including thirteen studies concerning opening wedge HTO and three studies involving closing wedge HTO. Clinical outcomes were only reported in studies which used opening wedge HTO. No significant differences were observed in all clinical outcomes between navigated and conventional HTO. Regarding radiographic outcomes, no significant difference in WBL ratio was observed between navigated and conventional HTO. Patients undergoing navigated HTO were associated with significantly greater in MA and lower in Outliers of alignment compared with those undergoing conventional HTO. Compared with conventional HTO, increase in TPS was significantly lower in navigated HTO group using opening wedge HTO, but decrease in TPS was significantly greater in navigated HTO group using closing wedge HTO.

CONCLUSION

Our meta-analysis demonstrated that navigated HTO offered more accuracy and precision of alignment correction, except WBL ratio. However, better clinical outcomes were not observed in navigation group.

Osteochondral Allograft Transplantation of the Knee in Patients Aged 40 Years and Older

BACKGROUND

Treatment of large chondral defects of the knee among patients aged ≥40 years remains a difficult clinical challenge owing to preexisting joint degeneration and the lack of treatment options short of arthroplasty.

PURPOSE

To characterize the survivorship, predictors of failure, and clinical outcomes of osteochondral allograft transplantation (OCA) of the knee among patients aged ≥40 years.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Prospectively collected data were reviewed for 54 consecutive patients aged ≥40 years who were treated with OCA. Preoperative levels of osteoarthritis (according to Kellgren-Lawrence classification) and meniscal volume and quality were graded from review of radiographs and magnetic resonance imaging. Complications, reoperations, and patient responses to validated outcome measures were reviewed. A minimum follow-up of 2 years was required for analysis. Failure was defined by any removal or revision of the allograft or conversion to arthroplasty.

RESULTS

Among 51 patients (mean age, 48 years; range, 40-63 years; 65% male), a total of 52 knees had symptomatic focal cartilage lesions (up to 2 affected areas) that were classified as Outerbridge grade 4 at the time of OCA and did not involve substantial bone loss requiring shell allografts or additional bone grafting. Mean duration of follow-up was 3.6 years (range, 2-11 years). After OCA, 21 knees (40%) underwent reoperation, including 14 failures (27%) consisting of revision OCA (n = 1), unicompartmental knee arthroplasty (n = 5), and total knee arthroplasty (n = 8). Mean time to failure was 33 months, and 2- and 4-year survivorship rates were 88% and 73%, respectively. Male sex (hazard ratio = 4.18, 95% CI = 1.12-27.13) and a higher number of previous ipsilateral knee operations (hazard ratio = 1.70 per increase in 1 surgical procedure, 95% CI = 1.03-2.83) were predictors of failure. A higher Kellgren-Lawrence osteoarthritis grade on preoperative radiographs was associated with higher failure rates in the Kaplan-Meier analysis but not the multivariate model. At final follow-up, clinically significant improvements were noted in the pain (mean score, 47.8 to 67.6) and physical functioning (56.8 to 79.1) subscales of the Short Form-36, as well as the International Knee Documentation Committee subjective form (45.0 to 63.6), Knee Outcome Survey-Activities of Daily Living (64.5 to 80.1), and overall condition statement (4.5 to 6.8) ( P < .001). No significant changes were noted for the Marx Activity Rating Scale (5.1 to 3.9, P = .789).

CONCLUSION

A higher failure rate was found in this series of patients aged ≥40 years who were treated with OCA as compared with other studies of younger populations. However, for select older patients, OCA can be a good midterm treatment option for cartilage defects of the knee.

Association Between the Single Assessment Numeric Evaluation and the Western Ontario and McMaster Universities Osteoarthritis Index

CONTEXT

  Patient-reported outcomes (PROs) evaluate how patients describe symptoms as well as level of physical function or quality of life. The Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index is one of the most common PROs used to assess disability in patients with knee osteoarthritis (OA), yet the Single Assessment Numeric Evaluation (SANE) is a single-question instrument that may improve the efficiency associated with the measurement of patient function.

OBJECTIVE

  To determine the associations between (1) SANE_Function and the physical dysfunction subsection of the WOMAC index (WOMAC_Dysfunction) before rehabilitation and after a 4-week therapeutic exercise intervention as well as (2) the percentage change in SANE_Function and WOMAC_Dysfunction in people with knee OA after 4 weeks of therapeutic exercise.

DESIGN

  Cross-sectional study.

SETTING

  Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  Thirty-six participants (15 men, 21 women) with radiographic knee OA.

INTERVENTION(S)

  Participants completed 12 sessions (over a 4-week period) of therapeutic exercise to strengthen the lower extremity.

MAIN OUTCOME MEASURE(S)

  The SANE_Function and WOMAC_Dysfunction (WOMAC_Dysfunction normalized to 100%) scores were collected before and after the 4-week intervention. Percentage change scores over the 4-week intervention were calculated for both measures.

RESULTS

  Participants with a higher SANE_Function score demonstrated a lower WOMAC_Dysfunction score at baseline (r_s = -0.44, P = .007) and at the 4-week time point (r_s = -0.69, P < .001). There was a nonsignificant and weak association between the changes in the SANE_Function and WOMAC_Dysfunction scores over the 4 weeks of therapeutic exercise (r_s = -0.17, P < .43).

CONCLUSIONS

  The SANE_Function and WOMAC_Dysfunction scores demonstrated moderate to weak associations before and after a 4-week exercise program, respectively, whereas the changes in SANE_Function and WOMAC_Dysfunction scores were not associated. These PROs may be measuring different aspects of self-reported function and therefore should not be used interchangeably to determine a therapeutic response.

High Short-Term Failure Rate Associated With Decellularized Osteochondral Allograft for Treatment of Knee Cartilage Lesions

PURPOSE

To report the short-term clinical and radiographic outcomes following the use of decellularized osteochondral (OC) allograft plugs in the treatment of distal femoral OC lesions.

METHODS

An Institutional Review Board-approved database with prospectively collected data was used to identify patients treated with the decellularized OC allograft plugs implant. Demographic information, patient-reported outcomes, magnetic resonance imaging (MRI), and the number and type of reoperations were assessed. Failure was defined as revision surgery with removal of the implant. Patients were evaluated pre- and postoperatively using the Short Form-36, Activity of Daily Living Score, International Knee Documentation Committee Subjective Evaluation, Cincinnati Knee Rating System, and Marx Activity Scale. MRIs were evaluated using the OsteoChondral Allograft MRI Scoring System.

RESULTS

Thirty-four patients were identified, with a mean age of 45 (±11.9) years; 71% were male. Fifteen (44%) patients had undergone prior ipsilateral surgical intervention. Mean defect size was 4 (±1.5) cm², and median number of allografts per knee was 2 (range, 1-5). Mean follow-up duration was 15.5 months (range, 6-24). Ten patients (29%) required revision surgery with removal of the implant. Implant survivorship was 61% at 2 years. Female gender was independently predictive of failure, with a hazard ratio of 9.4 (95% confidence interval [CI], 2.0-58.9; P = .005). Defect size was also independently predictive of failure, with a hazard ratio of 1.9 per 1 cm² increase (95% CI, 1.2-3.1; P = .005). MRIs obtained at 1 year postoperatively demonstrated significantly improved osseous integration (P = .0086) and opposing cartilage (P = .019) in the nonfailure group as compared with the failure group.

CONCLUSIONS

Based on the high short-term failure rate observed in this study, the authors advise that a decellularized OC allograft plugs implant should be used with caution in the treatment of OC lesions of the knee, as similar outcomes have not been noted with other cartilage restoration techniques. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched-Group Analysis With Minimum 2-Year Follow-Up

PURPOSE

To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up.

METHODS

After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm² in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure.

RESULTS

A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups.

CONCLUSIONS

OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Condyle-Specific Matching Does Not Improve Midterm Clinical Outcomes of Osteochondral Allograft Transplantation in the Knee

BACKGROUND

Condyle-specific matching for osteochondral allograft transplantation (OCA) pairs donor and recipient condyles in an attempt to minimize articular incongruity. While the majority of cartilage defects are located on the medial femoral condyle, lateral femoral condyles are more commonly available as a graft source. The purpose of this study was to compare the clinical outcomes of patients treated with non-orthotopic (lateral-to-medial condyle or medial-to-lateral condyle) OCA with those treated with traditional orthotopic (medial-to-medial condyle or lateral-to-lateral condyle) OCA. We hypothesized that clinical outcomes would be similar between groups at midterm follow-up.

METHODS

A retrospective review of prospectively collected data on patients treated with OCA from 2000 to 2014 was conducted. Seventy-seven patients with a full-thickness cartilage defect of a femoral condyle were treated with either orthotopic (n = 50) or non-orthotopic (n = 27) OCA. A minimum follow-up of 2 years was required for analysis. Patients in each group were matched according to sex, age, and total chondral defect size. Reoperations and patient responses to validated outcome measures were reviewed. Failure was defined as any revision cartilage procedure or conversion to knee arthroplasty.

RESULTS

The mean duration of follow-up was 4.0 years (range, 2 to 16 years). The orthotopic and non-orthotopic OCA groups were comparable in terms of demographics, the mean number of prior ipsilateral knee operations, and the percentage of concomitant procedures at baseline. Reoperation (p = 0.427) and failure (p = 0.917) rates did not differ significantly between groups. Both groups demonstrated significant increases in the Short Form-36 (SF-36) physical functioning and pain, International Knee Documentation Committee (IKDC), and Knee Outcome Survey-Activities of Daily Living (KOS-ADL) scores compared with baseline (p < 0.004). Outcome scores (baseline and postoperative) and change scores did not differ significantly between groups.

CONCLUSIONS

Clinical outcomes do not differ between patients treated with orthotopic OCA and those treated with non-orthotopic OCA, suggesting that condyle-specific matching may not be necessary.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Biochemical markers of cartilage metabolism are associated with walking biomechanics 6-months following anterior cruciate ligament reconstruction

The purpose of our study was to determine the association between biomechanical outcomes of walking gait (peak vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR], and knee adduction moment [KAM]) 6 months following anterior cruciate ligament reconstruction (ACLR) and biochemical markers of serum type-II collagen turnover (collagen type-II cleavage product to collagen type-II C-propeptide [C2C:CPII]), plasma degenerative enzymes (matrix metalloproteinase-3 [MMP-3]), and a pro-inflammatory cytokine (interleukin-6 [IL-6]). Biochemical markers were evaluated within the first 2 weeks (6.5 ± 3.8 days) following ACL injury and again 6 months following ACLR in eighteen participants. All peak biomechanical outcomes were extracted from the first 50% of the stance phase of walking gait during a 6-month follow-up exam. Limb symmetry indices (LSI) were used to normalize the biomechanical outcomes in the ACLR limb to that of the contralateral limb (ACLR/contralateral). Bivariate correlations were used to assess associations between biomechanical and biochemical outcomes. Greater plasma MMP-3 concentrations after ACL injury and at the 6-month follow-up exam were associated with lesser KAM LSI. Lesser KAM was associated with greater plasma IL-6 at the 6-month follow-up exam. Similarly, lesser vGRF-LR LSI was associated with greater plasma MMP-3 concentrations at the 6-month follow-up exam. Lesser peak vGRF LSI was associated with higher C2C:CPII after ACL injury, yet this association was not significant after accounting for walking speed. Therefore, lesser biomechanical loading in the ACLR limb, compared to the contralateral limb, 6 months following ACLR may be related to deleterious joint tissue metabolism that could influence future cartilage breakdown. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2288-2297, 2017.

Functional performance 6 months after ACL reconstruction can predict return to participation in the same preinjury activity level 12 and 24 months after surgery

BACKGROUND

Assessing athletes' readiness is a key component for successful outcomes after ACL reconstruction (ACLR).

OBJECTIVES

To investigate whether return-to-activity criteria, individually or in combination, at 6 months after ACLR can predict return to participation in the same preinjury activity level at 12 and 24 months after ACLR.

METHODS

Ninety-five level I/II participants completed return-to-activity criteria testing (isometric quadriceps index, single-legged hop tests, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and Global Rating Score (GRS)) at 6 months after ACLR. The PASS group was defined as scoring >90% on all criteria and the FAIL group as scoring <90% on any criteria. At 12 and 24 months after ACLR, participants were asked if they had returned to participate in the same preinjury activity level or not. All return-to-activity criteria, except quadriceps index, were entered into the logistic regression model.

RESULTS

81% and 84.4% of the PASS group returned to participation in the same preinjury activity level, while only 44.2% and 46.4% of the FAIL group returned at 12 and 24 months, respectively, after ACLR. The 6-meter timed hop, single hop and triple hop limb symmetry indexes; GRS; and KOS-ADLS individually predicted the outcome of interest at 12 months after ACLR (range: R²: 0.12-0.22, p<0.024). In combination, they explained 27% of the variance (p=0.035). All hop tests, individually, predicted the outcome of interest at 24 months after ACLR (range: R²: 0.26-0.37; p<0.007); in combination they explained 45% of the variance (p<0.001).

CONCLUSION

Return to participation in the same preinjury activity level at 12 and 24 months after ACLR was higher in those who passed the criteria compared with those who failed. Individual and combined return-to-activity criteria predicted the outcomes of interest, with the hop tests as consistent predictors at 12 and 24 months after ACLR.

Validating the forgotten joint score-12 in patients after ACL reconstruction

BACKGROUND

The forgotten joint score-12 (FJS-12), used to measure postoperative joint awareness, has been extensively validated to assess outcomes after arthroplasty, however the new score has never been validated in evaluating anterior cruciate ligament (ACL) reconstruction. The purpose of our study was to validate the FJS-12 versus the knee injury and osteoarthritis outcome score (KOOS) for patients who have undergone ACL reconstruction.

METHODS

All patients who had undergone ACL reconstruction with the same arthroscopic surgical technique at our institution between 2011 and 2014 (medium-term follow-up group (M-FU)) or between 2000 and 2005 (long-term follow-up group (L-FU)) were considered for inclusion in the study. To analyze unidimensionality of the FJS-12, we calculated Cronbach's alpha, item-total correlations and conducted an exploratory principal component factor analysis. To assess convergent validity, we calculated Spearman correlation coefficients for the FJS-12 and its comparable scales.

RESULTS

We analyzed 58 patients of the M-FU (mean follow-up 31.5 (SD13.4) months, range 12-54), and 58 patients of the L-FU (mean follow-up 139 (SD15.2) months, range 120-179). The FJS-12 showed high internal consistency (Cronbach's alpha=0.95). Ceiling effects were considerably lower for the FJS-12 (M-FU 12.1%, L-FU 15.5%) compared with the KOOS subscales (M-FU 5.2-37.9%; L-FU 13.8-55.2%) and WOMAC subscales (M-FU 37.9-62.1%; L-FU 44.8-60.3%).

CONCLUSIONS

The FJS-12 is a valid measurement tool to evaluate outcomes of ACL reconstruction. This study extends the possibilities of measuring joint awareness as a patient-reported outcome parameter from joint arthroplasty to ACL reconstruction.

Improvements in Sexual Activity After Total Knee Arthroplasty

BACKGROUND

Sexual limitations in the setting of total knee arthroplasty (TKA) are poorly understood.

METHODS

Surveys were designed to assess preoperative and postoperative sexual function, and limitations were retrospectively administered to 91 sexually active TKA patients at an average of 2.1 years (range, 0.5-4.0) after surgery. Preoperative and postoperative responses were compared using 1-tailed and 2-proportion z tests, with P < .05 as the threshold for significance.

RESULTS

Before TKA, sexual quality and/or frequency was limited in 45% of patients because of their knee. Patients experienced an average 17.1 months (range, 0-60) of sexual limitations before surgery, resulting largely from pain (87%) and diminished range of motion or flexibility (44%). Fifty-five percent of patients reported the need to change their sexual positions to accommodate their knee, with 97% of these patients indicating the need to avoid kneeling during sex. Postoperatively, fewer patients had to adjust their sexual positions to accommodate their knee (55% vs 28%, P = .0005), and avoid bearing weight on the afflicted knee during sex (97% vs 79%, P = .0213). Patients resumed sexual activity after an average of 2.4 months (range, 0-18). Despite these general improvements, 25% of individuals had less sex in the first year after surgery. After 1 year of recovery, however, 60% indicated that they more easily engaged in sexual activity than in the previous year, with 84% of these patients experiencing less pain, and 30% experiencing greater mobility or range of motion.

CONCLUSION

TKA does not eliminate sexual limitations, but it significantly decreases kneeling dysfunction and gives patients more liberty in selecting their sexual positions.

No Clinically Important Difference in Knee Scores or Instability Between Transtibial and Inlay Techniques for PCL Reconstruction: A Systematic Review

BACKGROUND

It is unclear whether the biomechanical superiority of the inlay technique over the transtibial technique, arising from avoidance of the killer turn at the graft-tunnel margin of the proximal tibia during posterior cruciate ligament (PCL) reconstruction, leads to better knee scores or greater knee stability.

QUESTIONS/PURPOSES

This systematic review was designed to compare Tegner and Lysholm scores, and posterior residual laxity of the knee, between single-bundle PCL reconstruction using transtibial and inlay techniques.

METHODS

We searched MEDLINE^®, Embase^®, and the Cochrane Library for studies comparing Tegner and/or Lysholm scores and posterior residual laxity, in patients who underwent PCL single-bundle reconstruction with the transtibial and tibial inlay techniques. There were no restrictions on language or year of publication. Studies were included if they compared clinical outcomes in patients who underwent PCL single-bundle reconstruction with the transtibial and tibial inlay techniques; they simultaneously reported direct comparisons of transtibial and tibial inlay PCL single-bundle reconstruction; and their primary outcomes included comparisons of postoperative scores on knee outcome scales and posterior residual laxity. A total of seven studies (including 149 patients having surgery using a transtibial approach, and 148 with the tibial inlay approach) met the prespecified inclusion criteria and were analyzed in detail.

RESULTS

Our systematic review suggested that there are no clinically important differences between the transtibial and the tibial inlay single-bundle PCL reconstruction in terms of Tegner or Lysholm scores. Of the five studies that assessed Lysholm scores, one favored the transtibial approach and four concluded no difference on this endpoint; however, the observed differences in all studies where differences were observed were quite small (< 7 of 100 points on the Lysholm scale), and likely not clinically important. Of the four studies that compared postoperative Tegner scores, three identified no differences between the approaches, while one favored the tibial inlay approach by a small margin (0.5 of 11 points) suggesting that there likely is no clinically important difference between the approaches in Tegner scores, either. Finally, we identified no difference between the approaches in terms of residual laxity, either among the seven studies that presented data using Telos radiographs, or the five that reported on patients with residual laxity greater than Grade 2 on a four-grade scale of posterior drawer testing (28/107 for transtibial and 26/97 for tibial inlay).

CONCLUSION

We found no clinically important differences between the transtibial and tibial inlay approach for PCL reconstruction. Based on the best evidence now available, it appears that surgeons may select between these approaches based on clinical experience and the specific elements of each patient's presentation, since there do not appear to be important or obvious differences between the approaches with respect to knee scores or joint stability. Future randomized trials are needed to answer this question more definitively.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Do Patients Failing Return-to-Activity Criteria at 6 Months After Anterior Cruciate Ligament Reconstruction Continue Demonstrating Deficits at 2 Years?

BACKGROUND

The variability in outcomes after anterior cruciate ligament reconstruction (ACLR) might be related to the criteria that are used to determine athletes' readiness to return to their preinjury activity level. A battery of return-to-activity criteria (RTAC) that emphasize normal knee function and movement symmetry has been instituted to quantitatively determine athletes' readiness to return to preinjury activities.

PURPOSE

To investigate performance-based and patient-reported measures at 12 and 24 months after ACLR between patients who passed or failed RTAC at 6 months after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 108 patients who had participated in International Knee Documentation Committee level 1 or 2 sports activities completed RTAC testing at 6, 12, and 24 months after surgery. The RTAC included the isometric quadriceps strength index (QI), 4 single-legged hop tests, the Knee Outcome Survey-activities of daily living subscale (KOS-ADLS), and the global rating scale of perceived function (GRS). Patients who scored ≥90% on all RTAC were classified as the pass group, and those who scored <90% on any RTAC were classified as the fail group. At 12- and 24-month follow-ups, patients were asked if they had returned to the same preinjury activity level.

RESULTS

At the 6-month follow-up, there were 48 patients in the pass group and 47 in the fail group. At the 12-month follow-up, 31 patients (73.8%) from the pass group and 15 patients (39.5%) from the fail group passed RTAC, and at the 24-month follow-up, 25 patients (75.8%) from the pass group and 14 patients (51.9%) from the fail group passed RTAC. The rate of return to activities in the pass group was 81% and 84% at 12 and 24 months after ACLR, respectively, compared with only 44% and 46% in the fail group ( P ≤ .012), respectively; however, some patients in the fail group participated in preinjury activities without being cleared by their therapists. At 12 and 24 months, 60.5% and 48.1% of patients continued to fail again on the criteria, respectively. A statistically significant group × time interaction was found for the single hop and 6-m timed hop limb symmetry indices (LSIs) ( P ≤ .037), with only the fail group demonstrating a significant improvement over time. A main effect of group was detected for the QI and the crossover hop and triple hop LSIs ( P < .01), with patients in the pass group demonstrating higher performance. A main effect of time was detected for the crossover hop and triple hop LSIs and the GRS, with improvements seen in both groups ( P < .05).

CONCLUSION

Patients who passed the RTAC early after ACLR were more likely to demonstrate normal knee function and movement symmetry at 12 and 24 months postoperatively, while patients who failed the RTAC early were more likely to demonstrate impaired knee function and movement asymmetry at 12- and 24-month follow-ups. Patients in the pass group had a higher rate of return to their preinjury activity level compared with those in the fail group. A group of patients chose to return to their preinjury activities, even though they were functionally not ready.

Validity, Reliability, and Responsiveness of the Anterior Cruciate Ligament Quality of Life Measure: A Continuation of Its Overall Validation

OBJECTIVE

The purpose is to provide more validity, reliability, and responsiveness testing of the anterior cruciate ligament-quality of life instrument (ACL-QOL), particularly in light of consensus-based standards for the selection of health status measurement instruments (COSMIN) guidelines.

DESIGN

Prospective case series.

SETTING

An orthopedic surgical practice for consultation.

PATIENTS

A convenience sample of 579 ACL-deficient patients.

INTERVENTION

Anterior cruciate ligament reconstructive surgery.

MAIN OUTCOME MEASURES

Patients completed the ACL-QOL at initial visit and underwent reconstructive surgery. Patients were followed at 6, 12, and 24 months using the ACL-QOL to determine its validity and responsiveness. Cronbach's alpha was used to determine the unidimensionality of the ACL-QOL. A subset of patients took the ACL-QOL twice in a test-retest reliability analysis (intraclass correlation coefficient or ICC 2,k). Another subset of 24-month postsurgical patients measured the success of their surgery using a 7-point global rating scale of improvement as an anchor-based method of responsiveness.

RESULTS

Cronbach's alpha coefficients = 0.93, 0.95, 0.96, and 0.98 at 6, 12, and 24 months, respectively. Intraclass correlation coefficient = 0.60, SEM = 6.16, and confidence interval of 12.1 (CI 95%). Responsiveness was measured by comparing the 4 serial time periods. Patients improved significantly at each time period (P < 0.05, ETA squared 0.61). A 24-month ACL-QOL was significantly correlated (P > 0.05) to being "significantly better" or "somewhat better."

CONCLUSIONS

The results of this study added more validity, reliability, and responsiveness for the ACL-QOL. The ACL-QOL has completed 8 of 9 COSMIN criteria.

Outcome reporting following navigated high tibial osteotomy of the knee: a systematic review

PURPOSE

This systematic review evaluates radiographic and clinical outcome reporting following navigated high tibial osteotomy (HTO). Conventional HTO was used as a control to compare outcomes and furthermore investigate the quality of evidence in studies reporting outcomes for navigated HTO. It was hypothesized that navigated HTO will show superior clinical and radiographic outcomes compared to conventional HTO.

METHODS

Two independent reviewers searched PubMed, Ovid (MEDLINE), EMBASE, and Cochrane databases for studies reporting outcomes following navigated HTO. Titles, abstracts, and full-text were screened in duplicate using an a priori inclusion and exclusion criteria. Descriptive statistics were calculated using Minitab ^® statistical software. Methodological Index for Nonrandomized Studies (MINORS) and Cochrane Risk of Bias Scores were used to evaluate methodological quality.

RESULTS

Thirty-four studies which involved 2216 HTOs were analysed in this review, 1608 (72.6 %) navigated HTOs and 608 (27.4 %) conventional HTOs. The majority of studies were of level IV evidence (16). Clinical outcomes were reported in knee and function scores or range of motion comparisons. Postoperative clinical and functional scores were improved by navigated HTO although it is not demonstrated if there is significant improvement compared to conventional HTO. Most common clinical outcome score reported was Lysholm scores (6) which report postoperative scores of 87.8 (standard deviation 5.9) and 88.8 (standard deviation 5.9) for conventional and navigation-assisted HTO, respectively. Radiographic outcomes reported commonly were weight-bearing mechanical axis, coronal plane angle, and posterior tibial slope angle in the sagittal plane. Studies have shown HTO gives significant correction of mechanical alignment and navigated HTO produces significantly less change in posterior tibial slope postoperatively compared to conventional. The mean MINORS for the 17 non-comparative studies was 9/16, and 15/24 for the 14 non-randomized comparative studies.

CONCLUSION

Navigation HTO results in improved mechanical axis alignment and demonstrates significantly better control over the tibial slope angle change postoperatively compared to conventional methods; however, these improvements have not yet been reflected in clinical outcome scores. Overall the studies report HTO does create significantly improved knee scores and functions compared to patients' preoperative ratings regardless of technique. Future studies on HTO outcomes need to focus on consistency of outcome reporting.

LEVEL OF EVIDENCE

IV.

Cross-cultural translation of the Lysholm knee score in Chinese and its validation in patients with anterior cruciate ligament injury

Background

The Lysholm Knee Score (LKS) is widely used and is one of the most effective questionnaires employed to assess knee injuries. Although LKS has been translated into multiple languages, there is no Chinese version even though China has the largest population of patients with knee-joint injuries. The objective of our study was to develop the Chinese version of LKS (C-LKS) and assess its reliability, validity and responsiveness in Chinese patients with anterior cruciate ligament (ACL) injuries.

Methods

Study participants were mainly recruited among patients with ACL injuries scheduled for arthroscopic ACL reconstruction at our hospital. First, we developed the C-LKS in a five-step translation and cross-cultural adaptation procedure. Next, we calculated the Cronbach’s alpha, intraclass correlation coefficient (ICC), Pearson’s correlation coefficient (r), effect size (ES), and standardized response mean (SRM) to evaluate the reliability, validity, and responsiveness of C-LKS respectively.

Results

Overall, 126 patients with ACL injuries successfully completed the questionnaires. Acceptable internal consistency (Cronbach’s alpha = 0.726) as well as excellent test-retest reliability (ICC = 0.935) was found for C-LKS. Good or moderate correlation (r = 0.514–0.837) was determined among C-LKS and International Knee Documentation Committee Subjective Knee Form (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), physical subscales of SF-36; C-LKS also had fair or moderate correlation (r = 0.207–0.462) with the other subscales of SF-36, which adequately illustrated that good validity was included in C-LKS. In addition, good responsiveness was also observed in C-LKS (ES = 1.36,SRM = 1.26).

Conclusions

We have shown that our developed C-LKS questionnaire is reliable, valid and responsible for the evaluation of Chinese-speaking patients with ACL injuries and it would be an effective instrument.

Cross-cultural Adaptation and Validation of the Simplified Chinese Version of the Knee Outcome Survey Activities of Daily Living Scale

PURPOSE

To perform a cross-cultural adaptation and translation of the original version of the Activities of Daily Living Scale of the Knee Outcome Survey into Simplified Chinese and validate of the Simplified Chinese version.

METHODS

The original version was translated and cross-culturally adapted into Simplified Chinese according to the guidelines and the recommendations of the American Academy of Orthopaedic Surgeons Outcome Committee. A total of 213 patients (96 male, 117 female) were selected to participate in our investigation. The inclusion criteria were as follows: 18 years of age and older, able to speak Chinese Mandarin and read Simplified Chinese, and referred to physical therapy for evaluation and treatment for a knee disorder. The exclusion criteria were as follows: patients who had disorders or impairments involving both knees, patients who had other conditions that could affect lower extremity function, patients with physical therapy related to the knee in the previous 1 month, and patients with psychological problems. Each participant was asked to complete the Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS), International Knee Documentation Committee Subjective Knee Form, Western Ontario and McMaster Universities Osteoarthritis Index, and Short Form 36 forms and to provide baseline demographic data. Each participant completed the KOS-ADLS twice on 2 nonconsecutive days for reliability evaluation. A portion of the participants (n = 161) finished the KOS-ADLS a third time 4 weeks after physical treatment to test responsiveness.

RESULTS

The original version of the KOS-ADLS was well adapted and translated into Simplified Chinese. Simplified Chinese of KOS-ADLS was shown to have good internal consistency (Cronbach's alpha = 0.855 to 0.929), great test-retest reliability (intraclass correlation coefficient = 0.935 to 0.961), high construct validity as we hypothesized (significant correlations with Short Form 36 subscales, Western Ontario and McMaster Universities Osteoarthritis Index, and International Knee Documentation Committee Subjective Knee Form), and high responsiveness (standard response means = 0.97 to 1.23, standard effect size = 0.81 to 0.91).

CONCLUSIONS

Simplified Chinese of KOS-ADLS was shown to have good reliability, validity, and responsiveness for use in patients with knee disorders in China.

LEVEL OF EVIDENCE

Level II, testing of previously developed diagnostic criteria in a series of consecutive patients with universally applied gold standard.

Knee Injury and Osteoarthritis Outcome Score has higher responsiveness and lower ceiling effect than Knee Society Function Score after total knee arthroplasty

PURPOSE

To compare the following subjective scoring instruments: the Knee Society Function (KS-F) Score and Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients who underwent total knee arthroplasty (TKA) by assessing standard metrics related to the utility of each instrument, including responsiveness, ceiling effect, and distribution of scores.

METHODS

Patients undergoing TKA for osteoarthritis (n = 82) were evaluated pre-operatively and post-operatively at a median time of 1 year (range 0.7-3.6 years) using the KS-F score and KOOS. Responsiveness, the ability of a tool to measure change over time, was evaluated by computing the standardized response mean. Ceiling effects were determined by calculating the percentage of patients who attained the best-possible score.

RESULTS

The KOOS scale had higher standardized response mean than KS-F scale in the majority of subsections (except sports and recreation). The KOOS had a lower ceiling effect in the majority of subsections (except pain) and was significantly lower on the symptoms and quality of life subscales (both p < 0.05). Scores were not normally distributed for either KS-F or KOOS scales.

CONCLUSIONS

Since the KOOS scale had a higher responsiveness and a lower ceiling effect, it appears to be a superior outcome tool versus the KS-F scale when evaluating the outcomes of TKA patients.

LEVEL OF EVIDENCE

Diagnostic Study, Level I.

Reliability of Physical Activity Measures During Free-Living Activities in People After Total Knee Arthroplasty

BACKGROUND

Few instruments that measure physical activity (PA) can accurately quantify PA performed at light and moderate intensities, which is particularly relevant in older adults. The evidence of their reliability in free-living conditions is limited.

OBJECTIVE

The study objectives were: (1) to determine the test-retest reliability of the Actigraph (ACT), SenseWear Armband (SWA), and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in assessing free-living PA at light and moderate intensities in people after total knee arthroplasty; (2) to compare the reliability of the 3 instruments relative to each other; and (3) to determine the reliability of commonly used monitoring time frames (24 hours, waking hours, and 10 hours from awakening).

DESIGN

A one-group, repeated-measures design was used.

METHODS

Participants wore the activity monitors for 2 weeks, and the CHAMPS questionnaire was completed at the end of each week. Test-retest reliability was determined by using the intraclass correlation coefficient (ICC [2,k]) to compare PA measures from one week with those from the other week.

RESULTS

Data from 28 participants who reported similar PA during the 2 weeks were included in the analysis. The mean age of these participants was 69 years (SD=8), and 75% of them were women. Reliability ranged from moderate to excellent for the ACT (ICC=.75-.86) and was excellent for the SWA (ICC=.93-.95) and the CHAMPS questionnaire (ICC=.86-.92). The 95% confidence intervals (95% CI) of the ICCs from the SWA were the only ones within the excellent reliability range (.85-.98). The CHAMPS questionnaire showed systematic bias, with less PA being reported in week 2. The reliability of PA measures in the waking-hour time frame was comparable to that in the 24-hour time frame and reflected most PA performed during this period.

LIMITATIONS

Reliability may be lower for time intervals longer than 1 week.

CONCLUSIONS

All PA measures showed good reliability. The reliability of the ACT was lower than those of the SWA and the CHAMPS questionnaire. The SWA provided more precise reliability estimates. Wearing PA monitors during waking hours provided sufficiently reliable measures and can reduce the burden on people wearing them.

Return to Play After Periacetabular Osteotomy for Treatment of Acetabular Dysplasia in Adolescent and Young Adult Athletes

BACKGROUND

The Bernese periacetabular osteotomy (PAO) is an effective surgical treatment option for symptomatic acetabular dysplasia. Little evidence exists regarding the results of PAO and rates of return to play (RTP) in an athletic population.

HYPOTHESIS

The majority of athletes will demonstrate improvements in functional outcome measures, such as the modified Harris Hip Score and Hip Disability and Osteoarthritis Outcome Score, and will be able to return to sports after PAO.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A comprehensive surgical hip database at an academic referral center was used to identify a subpopulation of athletes on whom PAO was performed. Data analyzed included preceding surgeries, reoperations, and RTP timing and features. Standard pre- and postoperative radiologic parameters and validated functional outcome measures were assessed, and a regression model assessed risk factors for prolonged time to RTP.

RESULTS

Of 245 PAOs performed over the 5-year study period, 46 were performed in 41 patients who met inclusion criteria for being an athlete (mean age, 26.2 years; range, 13-41 years; 36 females; 19% of all PAOs), representing a variety of sports. Prior surgery had been performed on 9 hips (20%). Only 1 post-PAO procedure (2%), excision of heterotopic ossification, was performed during the study period. At final follow-up (median, 3.1 years; range, 1.2-4.4 years), significant mean improvements were observed in modified Harris Hip Score (from 71 to 90; P < .001) and Hip Disability and Osteoarthritis Outcome Score (from 64 to 89; P < .001). The University of California-Los Angeles Activity Scale scores were maintained at a high level (range, 8.0-8.2; P = .28). RTP was reported in 80% of patients (37 of 46) at a median of 9 months postoperatively, with increased postoperative pain as the only independent predictor of longer time to RTP. Of these 37 athletes, 27 (73%) returned to the same level, although this was significantly less common (P = .06) in competitive athletes (11 of 19; 58%) than in recreational athletes (16 of 18; 89%). Among those who did return at the same level, 23 of 27 (85%) were able to maintain this level over time, but this was not significantly different between competitive (8 of 11; 73%) and recreational (15 of 16; 94%) athletes (P = .27).

CONCLUSION

Most athletic patients undergoing PAO are female patients and show postoperative improvements in function and return to athletic play. However, although there was no decline in overall activity level at a mean of 3 years, self-assessed athletic performance was attained and maintained in approximately one-half of the study population.

Transtibial technique versus two incisions in anterior cruciate ligament reconstruction: tunnel positioning, isometricity and functional evaluation

OBJECTIVE

To compare the transtibial and two-incision techniques for anterior cruciate ligament (ACL) reconstruction using a single band.

METHODS

A prospective and randomized study was conducted in blocks. Patients underwent ACL reconstruction by means of two techniques: transtibial (group 1: 20 patients) or two incisions (group 2: 20 patients). The radiographic positioning of the tunnel, inclination of the graft, graft isometricity and functional results (IKDC and Lysholm) were evaluated.

RESULTS

The positioning of the femoral tunnel on the anteroposterior radiograph, expressed as a mean percentage relative to the medial border of the tibial plateau, was 54.6% in group 1 and 60.8% in group 2 (p < 0.05). The positioning of the femoral tunnel on the lateral radiograph, expressed as a mean percentage relative to the anterior border of Blumensaat's line, was 68.4% in group 1 and 58% in group 2 (p < 0.05). The mean inclination of the graft was 19° in group 1 and 27.2° in group 2 (p < 0.05). The mean graft isometricity was 0.96 mm in group 1 and 1.33 mm in group 2 (p > 0.05). Group 2 had better results from the pivot-shift maneuver (p < 0.05).

CONCLUSION

The technique of two incisions allowed positioning of the femoral tunnel that was more lateralized and anteriorized, such that the graft was more inclined and there was a clinically better result from the pivot-shift maneuver. There was no difference in isometricity and no final functional result over the short follow-up time evaluated.

A conceptual framework for a sports knee injury performance profile (SKIPP) and return to activity criteria (RTAC)

Injuries to the knee, including intra-articular fractures, ligamentous ruptures, and meniscal and articular cartilage lesions, are commonplace within sports. Despite advancements in surgical techniques and enhanced rehabilitation, athletes returning to cutting, pivoting, and jumping sports after a knee injury are at greater risk of sustaining a second injury. The clinical utility of objective criteria presents a decision-making challenge to ensure athletes are fully rehabilitated and safe to return to sport. A system centered on specific indicators that can be used to develop a comprehensive profile to monitor rehabilitation progression and to establish return to activity criteria is recommended to clear athletes to begin a progressive and systematic approach to activities and sports. Integration of a sports knee injury performance profile with return to activity criteria can guide clinicians in facilitating an athlete's safe return to sport, prevention of subsequent injury, and life-long knee joint health.

Lateral Extra-articular Tenodesis Reduces Rotational Laxity When Combined With Anterior Cruciate Ligament Reconstruction: A Systematic Review of the Literature

PURPOSE

To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction would provide greater control of rotational laxity and improved clinical outcomes compared with ACL reconstruction alone.

METHODS

Two independent reviewers searched 9 databases for randomized and nonrandomized clinical studies comparing ACL reconstruction plus LET versus ACL reconstruction alone in a human adult population. All years and 5 languages were included. Animal and cadaveric studies, revision or repair surgical techniques, and studies focused on biomechanical outcomes were excluded. Quality assessment of the included studies was performed with the Cochrane Collaboration tool. Outcomes of interest included the pivot-shift test, KT-1000/-2000 measurements (MEDmetric, San Diego, CA), and International Knee Documentation Committee scores.

RESULTS

The literature search yielded 3,612 articles. After titles and abstracts were reviewed, 106 articles were selected for full-text review, of which 29 studies met the inclusion criteria (8 randomized and 21 nonrandomized studies). Of the 8 randomized studies, 3 concluded that the results were nonsignificant between treatment groups, 4 were in favor of the extra-articular tenodesis, and 1 was in favor of the ACL reconstruction alone. The Cochrane Collaboration tool showed an unclear to high risk of bias for most articles. A meta-analysis showed a statistically significant difference for the pivot-shift test (P = .002, I2 = 34%) in favor of ACL reconstruction with LET. No difference was found between the groups for International Knee Documentation Committee scores (P = .75, I2 = 19%) and KT-1000/-2000 measurements (P = .84, I2 = 34%).

CONCLUSIONS

Meta-analysis showed a statistically significant reduction in pivot shift in favor of the combined procedure. Studies lacked sufficient internal validity, sample size, methodologic consistency, and standardization of protocols and outcomes.

LEVEL OF EVIDENCE

Level III, systematic review of Level I, II, and III studies.

Outpatient rehabilitation care process factors and clinical outcomes among patients discharged home following unilateral total knee arthroplasty

Research examining care process variables and their relationship to clinical outcomes after total knee arthroplasty has focused primarily on inpatient variables. Care process factors related to outpatient rehabilitation have not been adequately examined. We conducted a retrospective review of 321 patients evaluating outpatient care process variables including use of continuous passive motion, home health physical therapy, number of days from inpatient discharge to beginning outpatient physical therapy, and aspects of outpatient physical therapy (number of visits, length of stay) as possible predictors of pain and disability outcomes of outpatient physical therapy. Only the number of days between inpatient discharge and outpatient physical therapy predicted better outcomes, suggesting that this may be a target for improving outcomes after total knee arthroplasty for patients discharged directly home.

The impact of total joint arthroplasty on sexual function in young, active patients

There is limited information regarding sexual function following total hip (THA) and knee arthroplasty (TKA). A multicenter study of 806 THA, 542 TKA, and 181 control patients less than 60 years of age was conducted using an independent survey center to question subjects about their sexual function. Only 1.3% of THA and 1.6% of TKA patients stated they were not sexually active due to their operation. No significant differences were noted in sexual function based on the bearing surface, femoral head size, or use of surface replacement arthroplasty in the hip cohort. Multivariate analysis revealed no difference in the percentage of patients sexually active following a THA or TKA (OR 1.19, P=0.38). Most young active patients return to sexual activity after hip and knee arthroplasty.

Relationship between biomechanical asymmetries during a step up and over task and stair climbing after total knee arthroplasty

BACKGROUND

Patients six months after total knee arthroplasty (TKA) demonstrate movement asymmetries and functional deficits, which may be related to poor functional performance. The aims of this study were to 1) compare biomechanical variables between subjects 6 months after TKA and an age-matched healthy control group during a step up and over task and 2) determine the relationship between quadriceps strength, movement patterns and stair climbing performance.

METHODS

Twenty patients 6 months following unilateral TKA and twenty healthy controls were enrolled. Participants completed questionnaires, isometric quadriceps strength testing and performance based tests to quantify functional performance. Motion analysis was performed during a step up and over task. Functional and biomechanical variables were analyzed using a 2 × 2 ANOVA. The symmetry ratios (operated/non-operated limb*100) for biomechanical variables were analyzed using independent t-tests. Pearson correlations were performed to determine the relationships between biomechanical variables, strength and stair climbing performance.

FINDINGS

In the TKA group, subjects had lower peak moments, power and sagittal plane excursion in the operated knee compared to the contralateral knee (P<0.05), while the hip on the operated side had greater power generation (P = 0.014). Compared to the control group, all symmetry ratios were significantly lower in the surgical group (P < 0.05). Stair climbing time was correlated with quadriceps strength of the operated limb (R = -0.762, P < 0.001).

INTERPRETATION

Individuals 6 months after TKA had worse performance with respect to biomechanics, quadriceps strength, and performance-based tests. Biomechanical asymmetries after TKA reduce the demand on the operated knee and increase reliance on the contralateral limb and ipsilateral hip.

Patient dissatisfaction following total knee replacement

A national, multi-centre study was designed in which a questionnaire quantifying the degree of patient satisfaction and residual symptoms in patients following total knee replacement (TKR) was administered by an independent, blinded third party survey centre. A total of 90% of patients reported satisfaction with the overall functioning of their knee, but 66% felt their knee to be ‘normal’, with the reported incidence of residual symptoms and functional problems ranging from 33% to 54%. Female patients and patients from low-income households had increased odds of reporting dissatisfaction. Neither the use of contemporary implant designs (gender-specific, high-flex, rotating platform) or custom cutting guides (CCG) with a neutral mechanical axis target improved patient-perceived outcomes. However, use of a CCG to perform a so-called kinematically aligned TKR showed a trend towards more patients reporting their knee to feel ‘normal’ when compared with a so called mechanically aligned TKR

This data shows a degree of dissatisfaction and residual symptoms following TKR, and that several recent modifications in implant design and surgical technique have not improved the current situation.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):96–100.

Comparison of the ceiling effect in the Lysholm score and the IKDC subjective score for assessing functional outcome after ACL reconstruction

BACKGROUND

To compare the ceiling effect of the Lysholm and IKDC subjective scores for assessing functional outcome after ACL reconstruction and evaluated the correlation with the one-leg hop test.

METHODS

A total of 134 patients who underwent ACL reconstruction between 2007 and 2011 were enrolled in this study. All patients fulfilled the postoperative 6- and 12-month evaluations. The ceiling effect of the Lysholm and IKDC subjective scores was assessed, and the correlations between two scales and one-leg hop test were analysed.

RESULTS

For the entire sample, the ceiling effect for the Lysholm score was 14.9% and 30.6% at 6 and 12 months postoperatively. The values for the IKDC subjective score were 5.2% and 17.2%, respectively. In all subjects, the correlation coefficients [95% confidence intervals] between the IKDC subjective score and one-leg hop test at 6 and 12months (r=0.492, [0.34 to 0.62]; r=0.296, [0.12 to 0.46]) were higher than those for the Lysholm score (r=0.355, [0.18 to 0.51]; r=0.241, [0.06 to 0.41]), respectively.(p<0.05).

CONCLUSION

With regard to evaluating ACL reconstruction outcomes in patients, no significant difference between the IKDC subjective and the Lysholm scores exists in terms of the amount of ceiling effect and the correlation with the LSI. However, the concern that the ceiling effect of the Lysholm score was greater than the IKDC subjective score, should be addressed in assessing the patient's functional status postoperatively.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Long-term results of autologous chondrocyte implantation in the knee for chronic chondral and osteochondral defects

BACKGROUND

Autologous chondrocyte implantation (ACI) has been shown to be effective in the midterm for the treatment of symptomatic articular cartilage lesions of the knee, but few long-term series have been published. The multioperated chronic articular cartilage defect remains a difficult condition to treat.

PURPOSE

To examine the long-term clinical results of ACI for large chronic articular cartilage defects, many treated as salvage.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a prospective case series of 104 patients with a mean age of 30.2 years and a symptomatic lesion of the articular cartilage in the knee, who underwent ACI between 1998 and 2001. The mean duration of symptoms before surgery was 7.8 years. The mean number of previous surgical procedures on the cartilage defect, excluding arthroscopic debridement, was 1.3. The defects were large, with a mean size of 477.1 mm(2) (range, 120-2500 mm(2)). The modified Cincinnati, Stanmore/Bentley, and visual analog scale for pain scoring systems were used to assess pain and functional outcomes at a minimum 10 years (mean, 10.4 years; range, 10-12 years).

RESULTS

Twenty-seven patients (26%) experienced graft failure at a mean of 5.7 years after ACI. Of the 73 patients who did not fail, 46 patients (63% of patients with a surviving graft) had an excellent result, 18 (25%) were good, 6 (8%) were fair, and 3 (4%) had a poor result. Of a total of 100 patients successfully followed up, 98 were satisfied with the ACI technique for their chronic knee pain and would undergo the procedure again.

CONCLUSION

Autologous chondrocyte implantation can provide a long-term solution in more than 70% of young patients of a difficult-to-treat group with large chronic articular cartilage lesions, even in the salvage situation.

Influence of response shift on early patient-reported outcomes following autologous chondrocyte implantation

PURPOSE

Response shift is the phenomenon by which an individual's standards for evaluation change over time. The purpose of this study was to determine whether patients undergoing autologous chondrocyte implantation (ACI) experience response shift.

METHODS

Forty-eight patients undergoing ACI participated. The "then-test" method was used to evaluate response shift in commonly used patient-reported outcome measures (PROMs)-the SF-36 Physical Component Scale (SF-36 PCS), WOMAC, IKDC, and Lysholm. Each PROM was completed pre- and 6 and 12 months post-surgery. At 6 and 12 months, an additional "then" version of each form was also completed. The "then" version was identical to the original except that patients were instructed to assess how they were prior to ACI. Traditional change, response shift adjusted change, and response shift magnitude were calculated at 6 and 12 months. T tests (p < 0.05) were used to compare traditional change to response-shift-adjusted change, and response shift magnitude values to previously established minimal detectable change.

RESULTS

There were no differences between traditional change and response-shift-adjusted change for any of the PROMs. The mean response shift magnitude value of the WOMAC at 6 months (15 ± 14, p = 0.047) was greater than the previously established minimal detectable change (10.9). The mean response shift magnitude value for the SF-36 PCS at 12 months (9.4 ± 6.8, p = 0.017) also exceeded the previously established minimal detectable change (6.6).

CONCLUSIONS

There was no evidence of a group-level effect for response shift. These results support the validity of pre-test/post-test research designs in evaluating treatment effects. However, there is evidence that response shifts may occur on a patient-by-patient basis, and scores on the WOMAC and SF-36 in particular may be influenced by response shift.

LEVEL OF EVIDENCE

II.

Short-term effects of patellar kinesio taping on pain and hop function in patients with patellofemoral pain syndrome

Background:

Patellofemoral pain syndrome (PFPS) is the most prevalent orthopaedic condition among physically active individuals, contributing to an estimated 30% to 40% of all sports medicine visits. Techniques using Kinesio Tape (KT) have become increasingly popular; however, there has been scant research supporting its use on patients with PFPS.

Hypothesis:

The use of patellar KT to treat patients with PFPS will provide a statistically significant improvement in short-term pain and single-leg hop measures as compared with sham placement of KT.

Study Design:

Nonrandomized controlled clinical trial with repeated-measures design.

Level of Evidence:

Level 3.

Methods:

Forty-nine subjects (41 females, 8 males) between the ages of 12 and 24 years with PFPS participated in this study. Each subject underwent patellar kinesio taping with both experimental and sham applications while completing 4 functional tasks and the single-leg triple jump test (STJT). The treatment outcome was analyzed using separate paired t tests to measure improvement on a numeric pain rating scale. A 2-way, 2 × 2 analysis of variance was used to analyze the relationship between taping condition (experimental vs sham) and side (involved vs uninvolved) for STJT scores.

Results:

Separate paired t tests found step-up, step-down, and STJT pain improvement statistically significant between taping conditions. The 2-factor analysis of variance yielded a significant main effect for taping condition, but the main effect for side was not significant. The interaction between taping condition and side was significant. This showed there was little change in STJT distance between repeated measures performed on the untaped, noninvolved leg. However, subjects’ STJT distances were significantly greater for the experimental KT application than the sham application for the involved side.

Conclusion:

Patellar kinesio taping provided an immediate and statistically significant improvement in pain and single-leg hop function in patients with PFPS when compared with a sham application. However, improvement in STJT scores did not surpass the minimally detectable change value, and therefore, the clinical effectiveness of KT for improving single-leg hop function was not established in the current study.

Clinical Relevance:

Kinesio Tape provides a viable, short-term method to control pain.

Isometric strength ratios of the hip musculature in females with patellofemoral pain: a comparison to pain-free controls

The purpose of the study was to compare hip agonist-antagonist isometric strength ratios between females with patellofemoral pain (PFP) syndrome and pain-free control group. One hundred and twenty females between 15 and 40 years of age (control group: n = 60; PFP group: n = 60) participated in the study. Hip adductor, abductor, medial rotator, lateral rotator, flexor, and extensor isometric strength were measured using a hand-held dynamometer. Comparisons in the hip adductor/abductor and medial/lateral rotator and flexor/extensor strength ratios were made between groups using independent t-tests. Group comparisons also were made between the anteromedial hip complex (adductor, medial rotator, and flexor musculature) and posterolateral hip complex (abductor, lateral rotator, and extensor musculature). On average, the hip adductor/abductor isometric strength ratio in the PFP group was 23% higher when compared with the control group (p = 0.01). The anteromedial/posterolateral complex ratio also was significantly higher in the PFP group (average 8%; p = 0.04). No significant group differences were found for the medial/lateral rotator ratio and flexor/extensor strength ratios. The results of this study demonstrate that females with PFP have altered hip strength ratios when compared with asymptomatic controls. These strength imbalances may explain the tendency of females with PFP to demonstrate kinematic tendencies that increase loading on the patellofemoral joint (i.e., dynamic knee valgus).