Biomedical subjects

Alexandra Kirkley

Publications and source records attributed to Alexandra Kirkley.

17 recordsLinked to original sources

PubMed2005

Prospective randomized clinical trial comparing the effectiveness of immediate arthroscopic stabilization versus immobilization and rehabilitation in first traumatic anterior dislocations of the shoulder: long-term evaluation.

PURPOSE: To report the long-term results of a prospective randomized clinical trial comparing the effectiveness of immediate arthroscopic stabilization versus immobilization and rehabilitation after a first traumatic anterior dislocation of the shoulder. TYPE OF STUDY: Randomized clinical trial. METHODS: Forty subjects younger than 30 years with a first traumatic anterior shoulder dislocation were randomized to receive immediate anterior stabilization plus rehabilitation or immobilization followed by rehabilitation. Patients completed the American Shoulder and Elbow Surgeons (ASES), Disabilities of the Arm, Shoulder and Hand (DASH), and the Western Ontario Shoulder Instability Index (WOSI) questionnaires. RESULTS: At an average follow-up of 75 months, there was a significant difference in the rate of redislocation between the groups but no statistical significant difference in shoulder function with the ASES or the DASH. The mean difference between the 2 groups with the WOSI estimates a small, but clinically significant difference. CONCLUSIONS: It is recommended that immediate arthroscopic stabilization is the treatment of choice in a subset of patients who are younger than 30 years and are higher level athletes, and the timing for surgery is good or their sport is risky, i.e., rugby, football, kayaking, rock climbing. LEVEL OF EVIDENCE: Level II.

Adult↗

PubMed2005

The familial predisposition toward tearing the anterior cruciate ligament: a case control study.

PURPOSE: A study of 171 surgical cases and 171 matched controls was conducted to investigate whether a familial predisposition toward tearing the anterior cruciate ligament of the knee exists. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: Patients who were diagnosed with an anterior cruciate ligament tear were matched by age (within 5 years), gender, and primary sport to subjects without an anterior cruciate ligament tear. All 342 subjects completed a questionnaire detailing their family history of anterior cruciate ligament tears. RESULTS: When controlling for subject age and number of relatives, participants with an anterior cruciate ligament tear were twice as likely to have a relative (first, second, or third degree) with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.00; 95% confidence interval, 1.19-3.33). When the analysis was limited to include only first-degree relatives, participants with an anterior cruciate ligament tear were slightly greater than twice as likely to have a first-degree relative with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.24; 95% confidence interval, 1.24-4.00). CONCLUSIONS: Findings are consistent with a familial predisposition toward tearing the anterior cruciate ligament. CLINICAL RELEVANCE: Future research should concentrate on identifying the potentially modifiable risk factors that may be passed through families and developing strategies for the prevention of anterior cruciate ligament injuries.

Adolescent↗

PubMed2005

A prospective, double-blind, randomized clinical trial comparing subacromial injection of betamethasone and xylocaine to xylocaine alone in chronic rotator cuff tendinosis.

BACKGROUND: Rotator cuff tendinosis is a common problem with significant health and economic effects. Nonoperative management includes the widespread use of subacromial steroid injections despite the lack of evidence of its efficacy. HYPOTHESIS: A subacromial injection of betamethasone will be more effective than xylocaine alone in improving the quality of life, impingement sign, and range of motion in patients who have chronic rotator cuff tendinosis or partial rotator cuff tears. STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1. METHODS: Patients with rotator cuff tendinosis or partial cuff tear with symptoms longer than 6 months, with failure of 6 weeks of physical therapy and 2 weeks of nonsteroidal anti-inflammatory drugs, who were older than 30 years of age, and who showed >50% improvement with the Neer impingement test were stratified for Workplace Safety and Insurance Board status and previous injection. Outcome measures--the Western Ontario Rotator Cuff Index; American Shoulder and Elbow Surgeons standardized form; Disabilities of the Arm, Shoulder and Hand; active forward elevation; active internal rotation; active external rotation; and the Neer impingement sign--were assessed at 2, 6, 12, and 24 weeks after injection. The injection into the subacromial space contained either 5 mL of 2% xylocaine alone or 4 mL of 2% xylocaine and 1 mL (6 mg) of betamethasone in an opaque syringe. RESULTS: In 58 patients (betamethasone group, n = 30; xylocaine group, n = 28), the authors found no statistically significant difference between the 2 treatment groups for all outcomes and time intervals. The scores for the Western Ontario Rotator Cuff Index at 3 months were xylocaine = 45.4% +/- 13% and betamethasone = 56.3% +/- 17% (P = .13). At 6 months, the scores were xylocaine = 51% +/- 32% and betamethasone = 59% +/- 26% (P = .38). All other outcomes showed similar values. As well, similar results were found for 2 and 6 weeks after injection. Both groups showed improvement from baseline in all outcomes. CONCLUSIONS: With the numbers available for this study, the authors found betamethasone to be no more effective in improving the quality of life, range of motion, or impingement sign than xylocaine alone in patients with chronic rotator cuff tendinosis for all follow-up time intervals evaluated.

Anesthetics, Local↗

PubMed2005

Quality-of-life outcome following hemiarthroplasty or total shoulder arthroplasty in patients with osteoarthritis. A prospective, randomized trial.

BACKGROUND: Both total shoulder arthroplasty and hemiarthroplasty have been used commonly to treat severe osteoarthritis of the shoulder; however, their effect on disease-specific quality-of-life outcome is unknown. The purpose of this study was to compare the quality-of-life outcome following hemiarthroplasty with that following total shoulder arthroplasty in patients with osteoarthritis of the shoulder. METHODS: Forty-two patients with a diagnosis of osteoarthritis of the shoulder were randomized to receive a hemiarthroplasty or a total shoulder arthroplasty. One patient died, and all others were evaluated preoperatively and at six weeks and three, six, twelve, eighteen, and twenty-four months postoperatively with use of a standardized format including a disease-specific quality-of-life measurement tool (Western Ontario Osteoarthritis of the Shoulder [WOOS] index), general shoulder rating scales (University of California at Los Angeles [UCLA] shoulder scale, Constant score, and American Shoulder and Elbow Surgeons [ASES] evaluation form), general pain scales (McGill pain score and visual analogue scale), and a global health measure (Short Form-36 [SF-36]). When a patient required revision of a hemiarthroplasty to a total shoulder arthroplasty, the last score before he or she "crossed over" was used for the analysis. RESULTS: Significant improvements in disease-specific quality of life were seen two years after both the total shoulder arthroplasties and the hemiarthroplasties. There were no significant differences in quality of life (WOOS score) between the group treated with total shoulder arthroplasty and that treated with hemiarthroplasty (90.6 +/- 13.2 and 81.5 +/- 24.1 points, respectively; p = 0.18). The other outcome measures demonstrated similar findings. Two patients in the hemiarthroplasty group crossed over to the other group by undergoing a revision to a total shoulder arthroplasty because of glenoid arthrosis. CONCLUSIONS: Both total shoulder arthroplasty and hemiarthroplasty improve disease-specific and general quality-of-life measurements. With the small number of patients in our study, we found no significant differences in these measurements between the two treatment groups. LEVEL OF EVIDENCE: Therapeutic Level I.

Aged↗

PubMed2005

A comparison of pain, strength, range of motion, and functional outcomes after hemiarthroplasty and total shoulder arthroplasty in patients with osteoarthritis of the shoulder. A systematic review and meta-analysis.

BACKGROUND: A systematic review of the literature was performed to estimate the impact of hemiarthroplasty compared with total shoulder arthroplasty on function and range of motion in patients suffering from osteoarthritis of the shoulder. METHODS: We conducted an electronic search for relevant studies published in any language from 1966 to 2004, a manual search of the proceedings from five major orthopaedic meetings from 1995 to 2003, and a review of the reference lists from potentially relevant studies. Four randomized clinical trials, with similar eligibility criteria and surgical techniques, that compared hemiarthroplasty and total shoulder arthroplasty for the treatment of primary osteoarthritis of the shoulder were found to be eligible. Authors from three of the four studies provided original patient data. Analysis of covariance focused on the two-year outcome and included a comparison of the aggregate University of California at Los Angeles shoulder score, four University of California at Los Angeles domain scores, and range of motion. RESULTS: A total of 112 patients (fifty managed with hemiarthroplasty and sixty-two managed with total shoulder arthroplasty), who had a mean age of sixty-eight years, were included in this analysis. A significant moderate effect was detected in the function domain of the University of California at Los Angeles shoulder score (p < 0.001) in favor of total shoulder arthroplasty (mean [and standard deviation], 8.1 +/- 0.3) compared with hemiarthroplasty (mean, 6.6 +/- 0.3). A significant difference in the pain score was found in favor of the total shoulder arthroplasty group (p < 0.0001). However, the large degree of heterogeneity (p = 0.006, I(2) = 80.2%) among the studies decreased our confidence that total shoulder arthroplasty provides a true, consistent benefit with regard to pain. There was a significant difference in the overall change in forward elevation of 13 degrees (95% confidence interval, 0.5 degrees to 26 degrees ) in favor of the total shoulder arthroplasty group (p = 0.008). CONCLUSIONS: At a minimum of two years of follow-up, total shoulder arthroplasty provided better functional outcome than hemiarthroplasty for patients with osteoarthritis of the shoulder. Since continuous degeneration of the glenoid after hemiarthroplasty or glenoid loosening after total shoulder arthroplasty may affect the eventual outcome, longer-term (five to ten-year) results are necessary to determine whether these findings remain consistent over time.

Activities of Daily Living↗

PubMed2004

High-resolution MRI and micro-CT in an ex vivo rabbit anterior cruciate ligament transection model of osteoarthritis.

OBJECTIVE: The aim of this study was to investigate the potential of using non-invasive, multi-modality imaging techniques to quantify disease progression in a rabbit model of experimentally induced osteoarthritis (OA). METHODS: High-resolution 4-T magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) techniques were implemented and validated in an ex vivo rabbit anterior cruciate ligament transection (ACLT) model of OA. A three-dimensional (3-D) rigid body registration technique was executed and evaluated to allow combined MR-CT analysis in co-registered image volumes of the knee. RESULTS: The 3-D MRI and micro-CT data formats made it possible to quantify cartilage damage, joint-space, and osseous changes in the rabbit ACLT model of OA. Spoiled gradient-recalled echo and fast-spin echo (FSE) sequences were jointly used to evaluate femorotibial cartilage and determine the sensitivity (78.3%) and specificity (95.3%) of 4-T MRI to detect clinically significant cartilage lesions. Overall precision error of the micro-CT technique for analysis of joint-space, volumetric bone mineral density (vBMD), and bone volume fraction (BV/TV) was 1.8%, 1.2%, and 2.0%, respectively. Co-registration of the 3-D data sets was achieved to within 0.36 mm for completed intermodality registrations, 0.22 mm for extrapolated intramodality registrations, and 0.50mm for extrapolated intermodality registrations. CONCLUSIONS: These results indicate that high-resolution 4-T MRI and micro-CT can be used to accurately quantify cartilage damage and calcified tissue changes in the rabbit ACLT model of OA. In addition, image volumes can be successfully co-registered to facilitate a comprehensive multi-modality examination of localized changes in both soft tissue and bone within the rabbit femorotibial joint.

Animals↗

PubMed2004

Ex vivo characterization of articular cartilage and bone lesions in a rabbit ACL transection model of osteoarthritis using MRI and micro-CT.

OBJECTIVE: To characterize the rabbit anterior cruciate ligament transection (ACLT) model of osteoarthritis (OA) at various stages of disease using high-resolution 3-D medical imaging systems, which, in turn, will facilitate future longitudinal studies evaluating disease progression and response to therapy in live animals. METHODS: Degenerative changes in femorotibial cartilage, volumetric bone mineral density (vBMD), bone volume fraction (BV/TV), and osteophyte volume were characterized ex vivo using 4-T magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) at 4, 8, and 12 weeks post-ACLT. These changes were subsequently correlated to macroscopic joint evaluation. RESULTS: Macroscopic assessment demonstrated progressive cartilage degeneration post-surgery, which was significantly correlated to MRI evaluation (r=0.82, P<0.0001). Linear regression analysis indicated that vBMD and BV/TV are linearly related such that as vBMD increases, BV/TV increases (P<0.0001). Micro-CT revealed bone loss at 4 and 8 weeks post-ACLT, but recovery to control values at 12 weeks post-ACLT. Volumetric BMD was not strongly correlated with macroscopic assessment of articular cartilage degeneration (r=-0.35, P<0.0001). Quantitative measurement of osteophyte volume demonstrated a statistically significant difference (with respect to control groups) at both 8 and 12 weeks post-ACLT, but not at 4 weeks post-ACLT. CONCLUSIONS: The rabbit ACLT model of OA demonstrates progressive cartilage degeneration and intermediate bone changes at 4, 8, and 12 weeks post-surgery. Cartilage and bone lesions were characterized ex vivo using 4-T MRI and micro-CT, and MRI assessment of cartilage degeneration was correlated to macroscopic grading.

Animals↗

PubMed2004

An evaluation of the apprehension, relocation, and surprise tests for anterior shoulder instability.

BACKGROUND: Although there are many studies describing tests for shoulder instability, there are few assessing the validity of these tests in diagnosing anterior shoulder instability. PURPOSE: To assess the validity of the apprehension, relocation, and surprise tests as predictors of anterior shoulder instability. STUDY DESIGN: Retrospective review of prospectively collected data. METHODS: Forty-six patients with a clear diagnosis of one of the following shoulder disorders were evaluated by four independent, blinded examiners: traumatic anterior instability (18), rotator cuff tendinosis (17), posterior instability (2), glenohumeral osteoarthritis (4), or multidirectional instability (5). Interobserver reliability was also determined. RESULTS: In subjects who had a feeling of apprehension on all three tests, the mean positive and negative predictive values were 93.6% and 71.9%, respectively. The surprise test was the single most accurate test (sensitivity = 63.89%; specificity = 98.91%). An improvement in the feeling of apprehension or pain with the relocation test added little to the value of the tests. Interobserver reliability was determined to be 0.83. CONCLUSIONS: and CLINICAL RELEVANCE: The results of this study suggest that a positive instability exam on all three tests is highly specific and predictive of traumatic anterior glenohumeral instability.

Fear↗

PubMed2003

The effect of early arthroscopic stabilization compared to nonsurgical treatment on proprioception after primary traumatic anterior dislocation of the shoulder.

This randomized clinical trial compared the effect of early arthroscopic stabilization and rehabilitation vs. standard immobilization and rehabilitation on measures of shoulder proprioception. Subjects with primary traumatic anterior dislocations of the shoulder were randomized into one of two groups: standard therapy of immobilization and rehabilitation (n=13) or arthroscopic stabilization followed by rehabilitation (n=11). At a minimum of 3 months posttreatment (mean 19 months) proprioception was evaluated using threshold to detection of passive motion (TTDPM) and reproduction of passive positioning (RPP) at 30 degrees and 60 degrees external rotation. There were no statistically significant differences between surgical and standard treatment groups in either TTDPM or RPP at start positions of 30 degrees and 60 degrees. These findings suggest that treatment by early arthroscopic stabilization and rehabilitation after primary traumatic anterior dislocation of the shoulder does not enhance proprioception more than standard immobilization and rehabilitation.

Adolescent↗

PubMed2003

Practical aspects of randomization and blinding in randomized clinical trials.

Randomization and blinding are important tools in determining the effectiveness of a new intervention and ensuring the validity of a clinical trial. However, randomness and haphazardness are not equivalent. Randomization cannot overcome poor experimental design or technique. Several types of randomization including historical controls and pseudorandomization are discussed, as well as methods of treatment allocation, stratification, and minimization techniques. The importance of decreasing bias and the advantages and disadvantages of blinding in randomized clinical trials are also covered.

Bias↗

PubMed2003

Development of disease-specific quality of life measurement tools.

Most of the conditions that physicians treat each day impact a patient's quality of life rather than the length or quantity of life. In orthopaedic surgery, traditional objective measures of patient outcome have included range of motion, strength, or radiographic variables. Although these measures have gained wide acceptance through their long-standing use, they are usually very poor indicators of the functional and psychological aspects of health. It makes sense to measure the phenomenon of health-related quality of life when assessing the relative efficacies of treatments that are available. If we can accept that health-related quality of life is important to measure, the next steps are to understand the types of instruments that are available and the appropriate methods by which these instruments should be developed and tested. Instruments fall into 2 general categories: generic or specific, each with specific advantages and disadvantages. The methodology for the development of quality of life tools emphasizes patient input and feedback. Determination of validity, reliability, and responsiveness in patients similar to those who will participate in trials is an important part of establishing the usefulness of an instrument.

Humans↗

PubMed2003

Scoring systems for the functional assessment of the shoulder.

A number of instruments have been developed to measure the quality of life in patients with various conditions of the shoulder. Older instruments appear to have been developed at a time when little information was available on the appropriate methodology for instrument development. Much progress has been made in this area, and currently an appropriate instrument exists for each of the main conditions of the shoulder. Investigators planning clinical trials should select modern instruments that have been developed with appropriate patient input for item generation and reduction, and established validity and reliability. Among the other factors discussed in this review, responsiveness of an instrument is an important consideration as it can serve to minimize the sample size for a proposed study. The shoulder instruments reviewed include the Rating Sheet for Bankart Repair (Rowe), ASES Shoulder Evaluation Form, UCLA Shoulder Score, The Constant Score, Disabilities of the Arm, Shoulder and Hand (DASH), the Shoulder Rating Questionnaire, the Simple Shoulder Test (SST), the Western Ontario Osteoarthritis of the Shoulder Index (WOOS), the Western Ontario Rotator Cuff Index (WORC), the Western Ontario Shoulder Instability Index (WOSI), Rotator Cuff Quality of Life (RC-QOL), and the Oxford Shoulder Scores (OSS).

Humans↗

PubMed2003

The development and evaluation of a disease-specific quality-of-life questionnaire for disorders of the rotator cuff: The Western Ontario Rotator Cuff Index.

OBJECTIVE: The purpose of this study was to develop a valid and reliable disease-specific quality-of-life measurement tool for patients with rotator cuff disease. DESIGN: Health-related quality-of-life measurement tool development. METHODS: Methodology for the development and evaluation of the tool included the following: 1) identification of a specific patient population, 2) generation of potential items, 3) item reduction, 4) pretesting the prototype instrument, 5) determination of reliability, and 6) validation. RESULTS: The final instrument, the Western Ontario Rotator Cuff Index, double dagger has 21 items representing five domains, each with a Visual Analog Scale-type response option. Construct validation demonstrated that this instrument correlated predictably with other measurement tools (Disabilities of the Arm, Shoulder, and Hand outcome measure; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form; University of California Los Angeles Shoulder Rating Scale; Constant Score; Rowe; Sickness Impact Profile; Short Form 36; and range of motion; 21 of 21 correlations within 0.19). Reliability was very high at 2 weeks, with an intraclass correlation coefficient of 0.96 and was more responsive (sensitive to change) than the other five shoulder measurement tools, global health instruments, and range of motion. CONCLUSIONS: This measurement tool can be used as the primary outcome in clinical trials evaluating treatments in this patient population, although its features are equally attractive for monitoring patients' progress in clinical practice.

Adult↗

PubMed2003

Agreement between magnetic resonance imaging and arthroscopic evaluation of the shoulder joint in primary anterior dislocation of the shoulder.

OBJECTIVE: To determine the effectiveness of magnetic resonance imaging in identifying shoulder pathology in patients with primary traumatic dislocation of the shoulder and to compare these findings with findings at the time of arthroscopic surgery. DESIGN: Correlation between arthroscopy and magnetic resonance imaging. PATIENTS: Sixteen patients, aged 18 to 30 years, who were randomized to the surgical arm of a study comparing the effectiveness of immediate arthroscopic surgery with immobilization and rehabilitation for primary traumatic anterior dislocation of the shoulder, were included in this study. INTERVENTIONS: Each patient underwent magnetic resonance imaging and a videotaped "tour" of the shoulder prior to any surgical intervention. MAIN OUTCOME MEASURE: Magnetic resonance scans and videotapes were reviewed for the presence or absence of abnormalities in 8 features of the shoulder, and concordant and discordant findings were evaluated. RESULTS: There was moderate correlation for superior labral lesions (kappa = 0.60) and fair agreement for rotator cuff tear (kappa = 0.355). When the joint capsule was assessed, there was only fair agreement for both the presence of an abnormality (kappa = 0.310) and redundancy and tear (kappa = 0.394). Both methods were sensitive for the detection of Hill-Sachs lesions (kappa = 1.0), although there was only moderate agreement (kappa = 0.44) on estimation of size. There was perfect agreement for the detection of Bankart lesions or equivalent capsulolabral disruption (kappa = 1.0). CONCLUSIONS: Magnetic resonance imaging can be considered a valuable tool for the detection of Hill-Sachs and Bankart lesions associated with primary traumatic anterior dislocations of the shoulder. Its ability to detect other pathologic lesions, however, is limited.

Adolescent↗

PubMed2002

Effect of a functional knee brace on knee flexion and extension strength after anterior cruciate ligament reconstruction.

OBJECTIVES: To investigate the effect of a knee brace on knee flexion and extension muscular strength of patients after anterior cruciate ligament (ACL) reconstruction and to evaluate whether the effect of the brace depends on patient symptoms and muscular strength. DESIGN: Repeated measures. SETTING: A university-based outpatient orthopedic clinic and musculoskeletal assessment laboratory. PARTICIPANTS: Twenty-seven patients (14 women, 13 men; mean age, 28+/-11 y) having undergone arthroscopically assisted ACL reconstruction by using a semitendinosus and gracilis autograft. INTERVENTION: A custom-fit ACL functional knee brace. MAIN OUTCOME MEASURES: The brace effect was calculated as the change in peak torque observed with the brace, expressed as a percentage of peak torque observed without the brace, during isokinetic concentric knee flexion and extension movements performed at 90 degrees /s. Patient symptoms were quantified by using a disease-specific health-related quality of life questionnaire. RESULTS: Knee flexion strength decreased significantly with the brace (mean brace effect=-7.3%, P<.05). The brace effect during knee flexion varied considerably (-52% to 47%) and was significantly related to peak torque observed without the brace (r=-.50, P<.01). All other comparisons and correlations were not significant. CONCLUSIONS: These findings suggest that brace effects depend on patient strength. A brace may inhibit knee flexion strength of stronger patients, yet result in no change or even improvements in strength of weaker patients. Future research is required to further elucidate which patients may derive most benefit or detriment from bracing.

Adult↗

PubMed2002

The use of the impingement test as a predictor of outcome following subacromial decompression for rotator cuff tendinosis.

PURPOSE: To evaluate the use of the impingement test as a predictor of outcome following subacromial decompression for patients with rotator cuff tendinosis. TYPE OF STUDY: Observational study. METHODS: An impingement test was administered to each patient immediately before surgery. Patients underwent a subacromial decompression and were assessed postoperatively at 3 and 6 months. The primary outcome measure was the Western Ontario Rotator Cuff Index (WORC). RESULTS: Thirty patients (mean age, 47.0 years; range, 29.4 to 71.2 years) took part in this study. There was no significant correlation between the classic impingement test (Neer's impingement sign before and after subacromial injection of local anesthetic) and the change in WORC score (r = -.174, P =.358). Similar results were obtained for the aggregate impingement test (pain at rest plus Neer's impingement sign plus Hawkins sign plus resisted abduction) before and after subacromial injection of local anesthetic (r = -.208, P =.270). When divided into categories of improvement following the classic impingement test (worse 0%-25%, 26%-50%, 51%-75%, 76%-100% better), there was no significant difference between groups for outcome as indicated by WORC score (P =.203). Results were similar for the aggregate impingement test (P =.271). CONCLUSIONS: The impingement test is a poor tool for predicting the success of subacromial decompression. There are 6 assumptions discussed that must hold true in order for the impingement test to be a useful predictor of outcome following subacromial decompression. If one or more of these assumptions are not met, or are only partially met, the impingement test would be rendered invalid as a predictor of outcome, as this study suggests.

Adult↗

PubMedDate not supplied

Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction.

BACKGROUND: Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness. HYPOTHESIS: Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction. STUDY DESIGN: Prospective evaluation of internal and external tibial rotation strength. METHODS: Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60 degrees /s, 120 degrees /s, and 180 degrees /s at a knee flexion angle of 90 degrees . RESULTS: The mean peak torque measurements for internal rotation strength of the operative limb (60 degrees /s, 17.4 +/- 4.5 ft-lb; 120 degrees /s, 13.9 +/- 3.3 ft-lb; 180 degrees /s, 11.6 +/- 3.0 ft-lb) were statistically different compared to the nonoperated limb (60 degrees /s, 20.5 +/- 4.7 ft-lb; 120 degrees /s, 15.9 +/- 3.8 ft-lb; 180 degrees /s, 13.4 +/- 3.8 ft-lb) at 60 degrees /s (P = .012), 120 degrees /s (P = .036), and 180 degrees /s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities. CONCLUSIONS: We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.

Adult↗