Eva Ageberg

Activity Level and Subjective Knee Function 15 Years After Anterior Cruciate Ligament Injury A Prospective, Longitudinal Study of Nonreconstructed Patients

Background The activity level and subjective knee function after an anterior cruciate ligament (ACL) injury treated without reconstruction have not been well elucidated. Hypothesis Patients with ACL injury can achieve good knee function and satisfactory long-term activity level when treated by early activity modification combined with rehabilitation. Study Design Cohort study (prognosis); Level of evidence, 2. Materials and Methods One hundred patients with an acute total ACL injury were observed for 15 years. All patients initially underwent arthroscopic surgery and a rehabilitation program. They were advised to modify their activity level, especially by avoiding contact sports. Patients with recurrent giving-way episodes and/or secondary meniscal injuries that required fixation (n = 6) were subsequently excluded and underwent reconstruction (n = 22). Sixty-seven patients with unilateral nonreconstructed ACL injury remained at the 15-year follow-up. The Lysholm knee score, Tegner activity level, and a visual analog score for global knee function were recorded at regular intervals. At the final follow-up, patients were further evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) subjective knee evaluation form. Results Forty patients resumed their preinjury activity level or higher within 3 years. The median activity level 15 years after injury had decreased from 7 to 4 according to Tegner activity scale (P < .001). The mean Lysholm knee score was 96 and 95, 1 and 3 years after injury, respectively, but declined to 86 after 15 years (P < .001). Forty-nine patients had good/excellent results, and 14 had fair (n = 6) or poor function (n = 8) at 15 years. Patients injured in contact sports scored lower in the quality of life sub-scale of KOOS than those injured in noncontact sports (P < .05). Thirteen of the 67 patients (19%) were reoperated with an arthroscopic procedure because of knee symptoms. Conclusion Early activity modification and neuromuscular rehabilitation resulted in a good knee function and an acceptable activity level in the majority of the nonreconstructed patients. The decline in activity level of patients engaged in contact sports at the time of injury affected their subjective quality of life more than patients involved in noncontact sports.

Sex Differences in Patient-Reported Outcomes After Anterior Cruciate Ligament Reconstruction Data From the Swedish Knee Ligament Register

Background: Female gender is a risk factor for sustaining anterior cruciate ligament (ACL) injury. However, little is known about possible sex differences in patients with ACL injury/reconstruction. Purpose: To study sex differences in patient-reported outcomes before and at 1 and 2 years after ACL reconstruction and to present reference values. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2005 and 2008, 10164 patients (mean age, 27 years; SD, 9.8; 42% females) with primary ACL reconstruction were registered in the Swedish national knee ligament register. There were 4438 (44%) of these patients (42% females) who had completed the knee-specific questionnaire, Knee injury and Osteoarthritis Outcome Score (KOOS), and 5255 (52%) who had completed the generic score of health status, EQ-5D, before surgery and were included in this study. Independent t tests were used to study sex differences in KOOS and EQ-5D preoperatively, 1 and 2 years postoperatively, and over time. Results: Preoperatively, female patients reported worse scores than male patients in 4 KOOS subscales (pain, symptoms, sport/recreation, quality of life) and EQ-5D, with the largest difference seen in KOOS sport/recreation (mean difference, 4.7; 95% confidence interval [CI], 3.0-6.3). At 1 year postoperatively, female patients reported worse scores than male patients in KOOS pain (mean difference, 1.4; 95% CI, 0.4-2.4) and KOOS sport/recreation (mean difference, 2.7; 95% CI, 0.9-4.4) and at 2 years postoperatively in KOOS sport/recreation (mean difference, 4.4; 95% CI, 2.1-6.7) and KOOS quality of life (mean difference, 2.4; 95% CI, 0.4-4.4). Female patients reported less improvement from 1 to 2 years postoperatively than male patients in KOOS sport/recreation (mean difference, 3.2; 95% CI, 0.3-6.1). In some age groups, female patients reported a clinically relevant worse KOOS sport/recreation score than male patients (mean difference ≥8). Conclusion: Female patients reported statistically significant worse outcomes than male patients before and at 1 and 2 years after ACL reconstruction. In some age groups, this difference was also clinically relevant. There were no clinically relevant sex differences in improvements over time. We suggest that possible sex differences be analyzed in future studies on evaluation after ACL injury/reconstruction.

Validity and inter-rater reliability of medio-lateral knee motion observed during a single-limb mini squat

BackgroundMuscle function may influence the risk of knee injury and outcomes following injury. Clinical tests, such as a single-limb mini squat, resemble conditions of daily life and are easy to administer. Fewer squats per 30 seconds indicate poorer function. However, the quality of movement, such as the medio-lateral knee motion may also be important. The aim was to validate an observational clinical test of assessing the medio-lateral knee motion, using a three-dimensional (3-D) motion analysis system. In addition, the inter-rater reliability was evaluated.MethodsTwenty-five (17 women) non-injured participants (mean age 25.6 years, range 18-37) were included. Visual analysis of the medio-lateral knee motion, scored as knee-over-foot or knee-medial-to-foot by two raters, and 3-D kinematic data were collected simultaneously during a single-limb mini squat. Frontal plane 2-D peak tibial, thigh, and knee varus-valgus angles, and 3-D peak hip internal-external rotation, and knee varus-valgus angles were calculated.ResultsTen subjects were scored as having a knee-medial-to-foot position and 15 subjects a knee-over-foot position assessed by visual inspection. In 2-D, the peak tibial angle (mean 89.0 (SE 0.7) vs mean 86.3 (SE 0.4) degrees, p = 0.001) and peak thigh angle (mean 77.4 (SE 1.0) vs mean 81.2 (SE 0.5) degrees, p = 0.001) with respect to the horizontal, indicated that the knee was more medially placed than the ankle and thigh, respectively. Thus, the knee was in more valgus (mean 11.6 (SE 1.5) vs 5.0 (SE 0.8) degrees, p < 0.001) in subjects with the knee-medial-to-foot than in those with a knee-over-foot position. In 3-D, the hip was more internally rotated in those with a knee-medial-to-foot than in those with a knee-over-foot position (mean 10.6 (SE 2.1) vs 4.8 (SE 1.8) degrees, p = 0.049), but there was no difference in knee valgus (mean 6.1 (SE 1.8) vs mean 5.0 (SE 1.2) degrees, p = 0.589). The kappa value and percent agreement, respectively, was >0.90 and 96 between raters.ConclusionsMedio-lateral motion of the knee can reliably be assessed during a single-leg mini-squat. The test is valid in 2-D, while the actual movement, in 3-D, is mainly exhibited as increased internal hip rotation. The single-limb mini squat is feasible and easy to administer in the clinical setting and in research to address lower extremity movement quality.

Muscle strength and functional performance in patients with anterior cruciate ligament injury treated with training and surgical reconstruction or training only: a two to five-year followup

OBJECTIVE To study muscle strength and functional performance in patients with anterior cruciate ligament (ACL) injury with or without surgical reconstruction 2 to 5 years after injury. Good muscle function is important in preventing early-onset osteoarthritis (OA), but the role of reconstructive surgery in restoring muscle function is unclear. METHODS Of 121 patients with ACL injury included in a randomized controlled trial on training and surgical reconstruction versus training only (the Knee, Anterior cruciate ligament, NON-surgical versus surgical treatment [KANON] study, ISRCTN: 84752559), 54 (mean age at followup 30 years, range 20-39, 28% women) were assessed a mean +/- SD of 3 +/- 0.9 years after injury with reliable, valid, and responsive test batteries for strength (knee extension, knee flexion, leg press) and hop performance (vertical jump, one-leg hop, side hop). The Limb Symmetry Index (LSI; injured leg divided by uninjured and multiplied by 100) value and absolute values were used for comparisons between groups (analysis of variance). An LSI >or=90% was considered normal. RESULTS There were no differences between the surgical and nonsurgical treatment groups in muscle strength or functional performance. Between 44% and 89% of subjects had normal muscle function in the single tests, and between 44% and 56% had normal function in the test batteries. CONCLUSION The lack of differences between patients treated with training and surgical reconstruction or training only indicates that reconstructive surgery is not a prerequisite for restoring muscle function. Abnormal muscle function, found in approximately one-third or more of the patients, may be a predictor of future knee OA.

Feasibility of neuromuscular training in patients with severe hip or knee OA: The individualized goal-based NEMEX-TJR training program

BackgroundAlthough improvements are achieved by general exercise, training to improve sensorimotor control may be needed for people with osteoarthritis (OA). The aim was to apply the principles of neuromuscular training, which have been successfully used in younger and middle-aged patients with knee injuries, to older patients with severe hip or knee OA. We hypothesized that the training program was feasible, determined as: 1) at most acceptable self-reported pain following training; 2) decreased or unchanged pain during the training period; 3) few joint specific adverse events related to training, and 4) achieved progression of training level during the training period.MethodsSeventy-six patients, between 60 and 77 years, with severe hip (n = 38, 55% women) or knee OA (n = 38, 61% women) underwent an individualized, goal-based neuromuscular training program (NEMEX-TJR) in groups for a median of 11 weeks (quartiles 7 to 15) prior to total joint replacement (TJR). Pain was self-reported immediately after each training session on a 0 to 10 cm, no pain to pain as bad as it could be, scale, where 0-2 indicates safe, > 2 to 5 acceptable and > 5 high risk pain. Joint specific adverse events were: not attending or ceasing training because of increased pain/problems in the index joint related to training, and self-reported pain > 5 after training. The level of difficulty of training was registered.ResultsPatients with severe OA of the hip or knee reported safe pain (median 2 cm) after training. Self-reported pain was lower at training sessions 10 and 20 (p = 0.04) and unchanged at training sessions 5 and 15 (p = 0.170, p = 0.161) compared with training session 1. There were no joint specific adverse events in terms of not attending or ceasing training. Few patients (n = 17, 22%) reported adverse events in terms of self-reported pain > 5 after one or more training sessions. Progression of training level was achieved over time (p < 0.001).ConclusionsThe NEMEX-TJR training program is feasible in patients with severe hip or knee OA, in terms of safe self-reported pain following training, decreased or unchanged pain during the training period, few joint specific adverse events, and achieved progression of training level during the training period.

Stabilometry and one-leg hop test have high test-retest reliability

The purpose of this study was to investigate the reliability of repeated measurements and a possible learning or tiring process in single‐limb stabilometry and one‐leg hop test. An additional purpose was to study the correlation between different stabilometric variables. Seventy‐five healthy subjects were examined twice with a median interval of 7 d, and with three consecutive measurements on each occasion. Single‐limb stabilometry and one‐leg hop test were found to have high reliability (ICC r= 0.68–0.83 and 0.96, respectively). The correlation between consecutive measurements was acceptable to high in stabilometry (r= 0.42–0.90, P=0.002–P<0.001) and high in the one‐leg hop test (r=0.91–0.97, P<0.001). A learning process over time was observed. The correlation between the stabilometric variables was high (r=0.73–0.95, P<0.001).

Balance in Single-Limb Stance in Patients With Anterior Cruciate Ligament Injury Relation to Knee Laxity, Proprioception, Muscle Strength, and Subjective Function

Background It has been shown previously that an anterior cruciate ligament injury may affect postural control, measured by balance in single-limb stance. To our knowledge, no studies have reported the influence of measures of impairment on postural control after such an injury. Purpose To assess the influence of knee laxity, proprioception, and muscle strength on balance in single-limb stance and to study the correlation between balance in single-limb stance and subjective estimation of extremity function. Study Design Cross-sectional study; Level of evidence, 3. Methods A total of 36 patients with a unilateral, nonoperated, nonacute anterior cruciate ligament injury were examined with regard to anterior knee laxity, proprioception, muscle strength, and stabilometry (amplitude and average speed of the center of pressure movements). Subjective estimation of extremity function was measured on a visual analog scale. Results The multiple regression analysis showed that high knee laxity values were associated with high amplitude values and low average speed. Poor proprioception and high muscle strength values were associated with low average speed among the women only. Low amplitude values correlated with better subjective function. Conclusion Anterior knee laxity, proprioception, and muscle strength seem to play a role in maintaining balance in single-limb stance. Patients with low amplitude values in stabilometry were those with better subjective function.

Proprioceptive deficits after ACL injury: are they clinically relevant?

Objective To establish the clinical relevance of proprioceptive deficits reported after anterior cruciate ligament (ACL) injury. Material and methods A literature search was done in electronic databases from January 1990 to June 2009. Inclusion criteria for studies were ACL deficient (ACL-D) and ACL reconstruction (ACL-R) articles written in English, Dutch or German and calculation of correlation(s) between proprioception tests and clinical outcome measures. Clinical outcome measures were muscle strength, laxity, hop test, balance, patient-reported outcome, objective knee score rating, patient satisfaction or return to sports. Studies included in the review were assessed on their methodological quality. Results In total 1161 studies were identified of which 24 met the inclusion criteria. Pooling of all data was not possible due to substantial differences in measurement techniques and data analysis. Most studies failed to perform reliability measurements of the test device used. In general, the correlation between proprioception and laxity, balance, hop tests and patient outcome was low. Four studies reported a moderate correlation between proprioception, strength, balance or hop test. Conclusion There is limited evidence that proprioceptive deficits as detected by commonly used tests adversely affect function in ACL-D and ACL-R patients. Development of new tests to determine the relevant role of the sensorimotor system is needed. These tests should ideally be used as screening tests for primary and secondary prevention of ACL injury.

Clinical measurements of proprioception, muscle strength and laxity in relation to function in the ACL-injured knee.

A knee injury with anterior cruciate ligament (ACL) rupture may cause deficits in proprioception, increased laxity and decreased muscle strength. Although it may be common knowledge that these factors affect knee function, only a few studies have been performed where this has been investigated in the clinical situation, and the results are not conclusive. The purpose of this study was therefore to investigate how and to what extent proprioception, laxity and strength affect knee joint function and evaluate if the methods commonly used for estimating these factors clinically seem to be relevant. The study encompassed 36 patients with ACL deficiency. A single-leg hop test for distance and subjective rating of knee function were defined as dependent variables and analyzed separately in stepwise linear regression models where proprioception, knee joint laxity, hamstrings and quadriceps strength, age and sex were defined as independent variables. Higher threshold values (poorer proprioception), increased side-to-side difference of anterior laxity and poorer strength significantly predicted shorter length of the hop test. Higher rating of subjective function corresponded to female gender, lesser side-to-side difference of anterior laxity and better proprioception.

Balance in single-limb stance in healthy subjects – reliability of testing procedure and the effect of short-duration sub-maximal cycling

BackgroundTo assess balance in single-limb stance, center of pressure movements can be registered by stabilometry with force platforms. This can be used for evaluation of injuries to the lower extremities. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement error. Previous studies have shown that the ability to maintain standing balance is decreased by fatiguing exercise. There is, however, a need for further studies regarding possible effects of general exercise on balance in single-limb stance. The aims of this study were: 1) to assess the test-retest reliability of balance variables measured in single-limb stance on a force platform, and 2) to study the effect of exercise on balance in single-limb stance, in healthy subjects.MethodsForty-two individuals were examined for test-retest reliability, and 24 individuals were tested before (pre-exercise) and after (post-exercise) short-duration, sub-maximal cycling. Amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. Mean difference between test and retest with 95% confidence interval, the intraclass correlation coefficient, and the Bland and Altman graphs with limits of agreement, were used as statistical methods for assessing test-retest reliability. The paired t-test was used for comparisons between pre- and post-exercise measurements.ResultsNo difference was found between test and retest. The intraclass correlation coefficients ranged from 0.79 to 0.95 in all stabilometric variables except one. The limits of agreement revealed that small changes in an individuals performance cannot be detected. Higher values were found after cycling in three of the eight stabilometric variables.ConclusionsThe absence of systematic variation and the high ICC values, indicate that the test is reliable for distinguishing among groups of subjects. However, relatively large differences in an individuals balance performance would be required to confidently state that a change is real. The higher values found after cycling, indicate compensatory mechanisms intended to maintain balance, or a decreased ability to maintain balance. It is recommended that average speed and DEV 10; the variables showing the best reliability and effects of exercise, be used in future studies.