Proprioceptive improvement in knees with anterior cruciate ligament reconstruction

Known-group validity of passive knee joint position sense: a comparison between individuals with unilateral anterior cruciate ligament reconstruction and healthy controls

BACKGROUND

Knee joint position sense (JPS) might be negatively affected after injuries to the anterior cruciate ligament (ACL). Recent systematic reviews suggest further investigation of psychometric properties, including validity, of knee JPS tests following ACL reconstruction (ACLR). This study investigated the known-group validity by comparing knee JPS errors between individuals who underwent unilateral ACLR and healthy controls.

METHODS

This cross-sectional study involved 36 men, including 19 after ACLR (ACLR group) and 17 healthy controls (control group). In both groups, the absolute error (AE), constant error (CE) and variable error (VE) of passive knee JPS were calculated in the flexion and extension directions, for two target angles (30° and 60° flexion) per direction. Discriminative validity was evaluated by comparing JPS errors between the operated and non-operated knees in the ACLR group. Known-group validity was evaluated by comparing JPS errors between the operated knees in the ACLR group and the asymptomatic non-dominant knees of healthy controls.

RESULTS

Mean AE, CE and VE for all tests were 4.1°, - 2.3° and 3.6° for the operated knees in the ACLR group, 5.5°, - 2.6° and 3.3° for the non-operated knees in the ACLR group and 4.6°, - 2.6° and 3.3° for the non-dominant knees in the control group, respectively, regardless of the test direction and target angle. The operated knees in the ACLR group did not show significantly greater JPS errors compared to the contralateral knees in the ACLR group and to the non-dominant knees in the control group (p ≥ 0.05). On the other hand, the non-operated knees showed significantly greater AE for the 0°-60° flexion test (p = 0.025) and CE for the 0°-30° flexion test (p = 0.024) than the operated knees in the ACLR group. JPS errors did not significantly differ in the operated knees in the ACLR group based on the direction of movement and the target angle. However, the errors were significantly higher when the knee was moved through a greater range compared to that of a lesser range between the starting and target angles.

CONCLUSION

The ACLR knees did not show greater passive JPS errors than the contralateral or control knees. The direction of movement and target angle did not influence the JPS acuity after ACLR. However, higher JPS errors were evident when the knee was moved through a greater range compared to a lesser range of motion. Further studies investigating the psychometric properties of standardized JPS tests following ACLR are warranted.

Proprioception Analysis following Anterior Cruciate Ligament Reconstruction using Stabilometry: A Prospective, Longitudinal Study

Objective  Commonly used methods for measuring proprioception have resulted in conflicting reports regarding knee proprioception with anterior cruciate ligament (ACL) rupture and the influence of ACL reconstruction. Methods  One hundred subjects (50 patients with radiologically and arthroscopically confirmed unilateral ACL rupture and 50 normal controls) were assessed with regards to proprioception using dynamic single-leg stance postural stabilometry. Instrumented knee ligament laxity and knee outcome scores were also measured. Of the 50 patients in the ACL group, 34 underwent reconstruction and were reassessed postoperatively. Results  There was a significant proprioceptive deficiency in the ACL group compared with their contralateral knee ( p  < 0.001) and to the control group ( p  = 0.01). There was a significant improvement in knee proprioception following ACL reconstruction compared to preoperative findings ( p  = 0.003). There was no correlation between ligament laxity measurements and outcome scores. A significant correlation was found preoperatively between outcome scores and proprioception measurements. This correlation was not found post-operatively. Pre-operative proprioception testing had a significant correlation (r = 0.46) with post-operative proprioception ( p  = 0.006). Conclusion  Patients with an ACL rupture had a proprioceptive deficit which improved following ligament reconstruction. Knee outcome scores had a better correlation with proprioception than ligament laxity. Proprioception may be a superior objective measure than ligament laxity in quantifying functional knee deficits and outcomes in patients with ACL ruptures. Level of Evidence III Therapeutic Study; Prospective Longitudinal Case-Control Study.

Properties of Knee Joint Position Sense Tests for Anterior Cruciate Ligament Injury: A Systematic Review and Meta-analysis

Background:

Knee proprioception is believed to be deficient after anterior cruciate ligament (ACL) injury. Tests of joint position sense (JPS) are commonly used to assess knee proprioception, but their psychometric properties (PMPs) are largely unknown.

Purpose:

To evaluate the PMPs (reliability, validity, and responsiveness) of existing knee JPS tests targeting individuals with ACL injury.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

PubMed, Allied and Complementary Medicine, CINAHL, SPORTDiscus, Web of Science, Scopus, CENTRAL, and ProQuest databases were searched to identify studies that assessed PMPs of knee JPS tests in individuals with ACL injury. The risk of bias for each included study was assessed and rated at the outcome level for each knee JPS test. Overall quality and levels of evidence for each PMP were rated according to established criteria. Meta-analyses with mean differences were conducted using random effects models when adequate data were available.

Results:

Included were 80 studies covering 119 versions of knee JPS tests. Meta-analyses indicated sufficient quality for known-groups and discriminative validity (ACL-injured knees vs knees of asymptomatic controls and contralateral noninjured knees, respectively), owing to significantly greater absolute errors for ACL-injured knees based on a strong level of evidence. A meta-analysis showed insufficient quality for responsiveness, which was attributed to a lack of significant change over time after diverse interventions with a moderate level of evidence. Statistical heterogeneity (I² > 40%) was evident in the majority of meta-analyses. All remaining PMPs (reliability, measurement error, criterion validity, convergent validity, and other PMPs related to responsiveness) were assessed qualitatively, and they failed to achieve a sufficient quality rating. This was a result of either the study outcomes not agreeing with the statistical cutoff values/hypotheses or the level of evidence being rated as conflicting/unknown or based on only a single study.

Conclusion:

Knee JPS tests appear to have sufficient validity in differentiating ACL-injured knees from asymptomatic knees. Further evidence of high methodologic quality is required to ascertain the reliability, responsiveness, and other types of validity assessed here. We recommend investigations that compare the modifiable methodologic components of knee JPS tests on their PMPs to develop standardized evidence-based tests.

Alterations in sensorimotor function after ACL reconstruction during active joint position sense testing. A systematic review

BACKGROUND

The anterior cruciate ligament (ACL) rupture can lead to impaired knee function. Reconstruction decreases the mechanical instability but might not have an impact on sensorimotor alterations.

OBJECTIVE

Evaluation of the sensorimotor function measured with the active joint position sense (JPS) test in anterior cruciate ligament (ACL) reconstructed patients compared to the contralateral side and a healthy control group.

METHODS

The databases MEDLINE, CINAHL, EMBASE, PEDro, Cochrane Library and SPORTDiscus were systematically searched from origin until April 2020. Studies published in English, German, French, Spanish or Italian language were included. Evaluation of the sensorimotor performance was restricted to the active joint position sense test in ACL reconstructed participants or healthy controls. The Preferred Items for Systematic Reviews and Meta-Analyses guidelines were followed. Study quality was evaluated using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data was descriptively synthesized.

RESULTS

Ten studies were included after application of the selective criteria. Higher angular deviation, reaching significant difference (p < 0.001) in one study, was shown up to three months after surgery in the affected limb. Six months post-operative significantly less error (p < 0.01) was found in the reconstructed leg compared to the contralateral side and healthy controls. One or more years after ACL reconstruction significant differences were inconsistent along the studies.

CONCLUSIONS

Altered sensorimotor function was present after ACL reconstruction. Due to inconsistencies and small magnitudes, clinical relevance might be questionable. JPS testing can be performed in acute injured persons and prospective studies could enhance knowledge of sensorimotor function throughout the rehabilitative processes.

Effects of neuromuscular training on knee proprioception in individuals with anterior cruciate ligament injury: a systematic review and GRADE evidence synthesis

OBJECTIVE

To systematically review and summarise the evidence for the effects of neuromuscular training compared with any other therapy (conventional training/sham) on knee proprioception following anterior cruciate ligament (ACL) injury.

DESIGN

Systematic Review.

DATA SOURCES

PubMed, CINAHL, SPORTDiscus, AMED, Scopus and Physical Education Index were searched from inception to February 2020.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials investigating the effects of neuromuscular training on knee-specific proprioception tests following a unilateral ACL injury were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened and extracted data and assessed risk of bias of the eligible studies using the Cochrane risk of bias 2 tool. Overall certainty in evidence was determined using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool.

RESULTS

Of 2706 articles retrieved, only 9 RCTs, comprising 327 individuals with an ACL reconstruction (ACLR), met the inclusion criteria. Neuromuscular training interventions varied across studies: whole body vibration therapy, Nintendo-Wii-Fit training, balance training, sport-specific exercises, backward walking, etc. Outcome measures included joint position sense (JPS; n=7), thresholds to detect passive motion (TTDPM; n=3) or quadriceps force control (QFC; n=1). Overall, between-group mean differences indicated inconsistent findings with an increase or decrease of errors associated with JPS by ≤2°, TTDPM by ≤1.5° and QFC by ≤6 Nm in the ACLR knee following neuromuscular training. Owing to serious concerns with three or more GRADE domains (risk of bias, inconsistency, indirectness or imprecision associated with the findings) for each outcome of interest across studies, the certainty of evidence was very low.

CONCLUSIONS

The heterogeneity of interventions, methodological limitations, inconsistency of effects (on JPS/TTDPM/QFC) preclude recommendation of one optimal neuromuscular training intervention for improving proprioception following ACL injury in clinical practice. There is a need for methodologically robust RCTs with homogenous populations with ACL injury (managed conservatively or with reconstruction), novel/well-designed neuromuscular training and valid proprioception assessments, which also seem to be lacking.

PROSPERO REGISTRATION NUMBER

CRD42018107349.

Histological and cellular evaluation of anterior cruciate ligament

BACKGROUND

We hypothesized that the torn anterior cruciate ligament (ACL) demonstrates a great healing response after initial trauma and has competent cells leading to the healing but differs in its response based on the type of tear and duration of injury. This study aimed to evaluate the histological and cellular responses to the injured ACL.

METHODS

Fifty-two tissue samples from the ACL were harvested from patients undergoing arthroscopy. Detailed histological and cellular examinations were performed for ligament angiogenesis, fibrocytes, and synovial tissue infiltration. We compared the cellular response to injury in partially and completely ruptured ACLs. The duration of ACL injury and its response to cellular characteristics were also examined. Immunohistochemical studies using cluster of differentiation 34 (CD34) staining was used to evaluate endothelial cells and fibrocytes.

RESULTS

We found a significantly higher density of synovial and ligament angiogenesis and fibrocytes at the torn end of ACL (Mann-Whitney, P < 0.050). Numerous fibrocytes were identified in complete ACL tears versus partial tears (Mann-Whitney = 0.020). Increased cellular proliferation was identified at the ruptured end of ACL remnant (Kruskal-Wallis, P < 0.050). The cellular proliferation of ruptured ACL decreased after 12 months.

CONCLUSIONS

Based on our findings of the time-dependent decrease in the cellular response at the torn ends of the ACL, we recommend early intervention, preservation of the ACL remnant, and primary ACL repair or augmented reconstruction.

Immunohistochemical analysis of sensory corpuscles in human transplants of the anterior cruciate ligament

Background

Sensory nerve endings in ligaments play an important role for the proprioceptive function. Clinical trials show that the sense of body position does not fully recover in the knee joint after reconstructive surgery of the ruptured anterior cruciate ligament. The aim of this study is to identify sensory corpuscles in autogenous and allogenous transplants of the ligament and to compare their quantity between the used allografts and autografts.

Methods

Thirty-three patients were included in this study. Three patellar tendon allografts, 14 patellar tendon autografts and 12 semitendinosus autografts were harvested during revision surgery after traumatic rerupture of the graft. The control consisted of 4 healthy anterior cruciate ligaments after fresh rupture. After haematoxylin staining, immunohistochemical analysis was performed using antibodies against S100, p75 and PGP9.5. Microscopical examination was carried out, and the number of mechanoreceptors was counted. Statistical analysis was performed using the Mann-Whitney U test.

Results

Two types of mechanoreceptors were identified in each graft: Ruffini corpuscles and free nerve endings. The number of Ruffini corpuscles per square centimeter was the highest in the control. Comparing the grafts, the highest number of receptors could be detected in the semitendinosus autograft. The amount of free nerve endings was higher in the semitendinosus and patellar tendon autografts than in the control; the allografts showed the lowest number of receptors. With increasing time after reconstruction, the number of both types of receptors showed a decrease in the semitendinosus graft, whereas it increased in the patellar tendon graft and allograft. The number of mechanoreceptors in the semitendinosus and patellar tendon graft decreased over time after graft-failure, whereas it increased slightly in the allograft.

Conclusion

This study was the first to identify mechanoreceptors in human transplants of the anterior cruciate ligament. The partial increase in the number of receptors over time after reconstruction could indicate a reinnervation of the grafts.

Proprioception deficiency in articular cartilage lesions of the knee

Purpose

The purpose of this study is to investigate the proprioceptive function of patients with isolated articular cartilage lesions of the knee as compared to normal controls.

Methods

The Cartilage group consisted of eight subjects with radiologically and arthroscopically confirmed, isolated, unilateral, articular cartilage lesions of the knee (Outerbridge grade III or IV). They were compared to 50 normal controls. Knee proprioception was assessed by dynamic postural stabilometry using the Biodex Balance SD System. Patient-reported outcome measures (PROMs) were used to evaluate all subjects.

Results

Proprioception of the injured knee of the Cartilage group was significantly poorer compared to that of the control group (p < 0.001). A significant proprioceptive deficit also was observed when the uninjured knees of the Cartilage group were compared to those in the Control group (p = 0.003). There was no significant proprioceptive difference between the injured and the contra-lateral uninjured knee of the Cartilage group (p = 0.116). A significant correlation was found between the proprioception measurements of the injured and uninjured knee of the Cartilage group (r = 0.76, p = 0.030). A significant difference was observed in all PROMs (p < 0.001) between the Cartilage and Control groups.

Conclusions

Patients with isolated articular cartilage lesions of the knee had a significant proprioceptive deficit as compared to normal controls. The deficiency was profound and even affected the proprioceptive function of the contra-lateral uninjured knee. This study has shown that articular cartilage lesions have a major influence on knee proprioception. However, it remains uncertain as to whether a proprioceptive deficit leads to osteoarthritis or is a consequence of it.

Quadriceps tendon autograft ACL reconstructed subjects overshoot target knee extension angle during active proprioception testing

PURPOSE

To compare the active joint position sense (JPS), muscle strength, and knee functions in individuals who had anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft, hamstring tendon autograft, tibialis anterior allograft and healthy individuals. It was hypothesized that when compared to an age and gender-matched healthy control group, subjects who were post-ACL reconstruction would display impaired active joint position sense, knee extensor and flexor strength symmetry and knee function at 1 year post-surgery. A secondary hypothesis was that differences would exist between the quadriceps tendon autograft, hamstring tendon autograft and tibialis anterior allograft groups.

METHODS

Sixty-seven patients with ACL reconstruction and 20 healthy individuals were included. Active JPS reproduction was measured at 15°, 45° and 75° of knee flexion. International Knee Documentation Committee (IKDC) subjective score and one-leg hop test were used to assess the functional status of the patients.

RESULTS

The JPS detection was different at the 15° target angle between groups (F_3.86 = 24.56, p < 0.001). A significantly higher proportion of quadriceps tendon autograft group patients failed to identify the 15° active JPS assessment position compared to the other groups (p < 0.0001). The quadriceps index was lower in patients compared to healthy individuals (p < 0.001), while the hamstring index was similar (n.s.). The knee functional outcomes were similar between ACL reconstructed groups and healthy controls (n.s.).

CONCLUSION

Knee proprioception deficits and impaired muscle strength were evident among patients at a mean 13.5 months post-ACL reconstruction compared with healthy controls. Patients who underwent ACL reconstruction using a quadriceps tendon autograft may be more likely to actively over-estimate knee position near terminal extension. Physiotherapists may need to focus greater attention on terminal knee extension proprioceptive awareness among this patient group.

LEVEL OF EVIDENCE

III.

Systematic Selection of Key Logistic Regression Variables for Risk Prediction Analyses: A Five-Factor Maximum Model

GENERAL AND CRITICAL REVIEW FORMAT

The evolution of clinical practice and medical technology has yielded an increasing number of clinical measures and tests to assess a patient's progression and return to sport readiness after injury. The plethora of available tests may be burdensome to clinicians in the absence of evidence that demonstrates the utility of a given measurement.

OBJECTIVE

Thus, there is a critical need to identify a discrete number of metrics to capture during clinical assessment to effectively and concisely guide patient care.

DATA SOURCES

The data sources included Pubmed and PMC Pubmed Central articles on the topic. Therefore, we present a systematic approach to injury risk analyses and how this concept may be used in algorithms for risk analyses for primary anterior cruciate ligament (ACL) injury in healthy athletes and patients after ACL reconstruction.

MAIN RESULTS

In this article, we present the five-factor maximum model, which states that in any predictive model, a maximum of 5 variables will contribute in a meaningful manner to any risk factor analysis.

CONCLUSIONS

We demonstrate how this model already exists for prevention of primary ACL injury, how this model may guide development of the second ACL injury risk analysis, and how the five-factor maximum model may be applied across the injury spectrum for development of the injury risk analysis.

Should Return to Sport be Delayed Until 2 Years After Anterior Cruciate Ligament Reconstruction? Biological and Functional Considerations

Anterior cruciate ligament (ACL) tears are common knee injuries sustained by athletes during sports participation. A devastating complication of returning to sport following ACL reconstruction (ACLR) is a second ACL injury. Strong evidence now indicates that younger, more active athletes are at particularly high risk for a second ACL injury, and this risk is greatest within the first 2 years following ACLR. Nearly one-third of the younger cohort that resumes sports participation will sustain a second ACL injury within the first 2 years after ACLR. The evidence indicates that the risk of second injury may abate over this time period. The incidence rate of second injuries in the first year after ACLR is significantly greater than the rate in the second year. The lower relative risk in the second year may be related to athletes achieving baseline joint health and function well after the current expected timeline (6-12 months) to be released to unrestricted activity. This highlights a considerable debate in the return to sport decision process as to whether an athlete should wait until 2 years after ACLR to return to unrestricted sports activity. In this review, we present evidence in the literature that athletes achieve baseline joint health and function approximately 2 years after ACLR. We postulate that delay in returning to sports for nearly 2 years will significantly reduce the incidence of second ACL injuries.

Effects of localized vibration on knee joint position sense in individuals with anterior cruciate ligament reconstruction

BACKGROUND

Anterior cruciate ligament injury can disrupt one's mechanoreceptors and result in decreased proprioception such as joint position sense and ultimately altered motor function. The application of localized vibration has been used to investigate the integrity of the sensorimotor system and the mechanisms of quadriceps function after anterior cruciate ligament injury and reconstruction. The purpose of the study is to evaluate joint position sense with and without vibration and compare among anterior cruciate ligament reconstructed, contralateral, and control limbs.

METHODS

Fourteen subjects with anterior cruciate ligament reconstruction (8 males and 6 females) and fourteen control subjects (7 males and 7 females) participated in the study. Subjects sat on an isokinetic dynamometer chair with localized vibration strapped on the quadriceps tendon while visual and auditory cues were removed. Subjects were asked to remember an active target position and replicate that position actively. The absolute difference between the target and replicated trial was used as joint position sense. There were three trials at three target positions (15, 45, and 75 degrees of knee flexion) with and without vibration. The order of testing conditions was randomized. One-way analysis of variance or non-parametric equivalent (Kruskal-Wallis test) was used to compare among limbs. Significance was set at P < 0.05 a priori.

FINDINGS

There were no significant joint position sense differences among anterior cruciate ligament reconstructed, contralateral, and control limbs with or without vibration (P = 0.207-0.914).

INTERPRETATION

There are several potential reasons for the current findings: vibration-induced post effect, locations of vibration, types of vibration, and rehabilitation status. Future studies should expand the current investigation and explore both sensory and motor functions in anterior cruciate ligament reconstructed subjects.

Proprioception in patients with posterior cruciate ligament tears: A meta-analysis comparison of reconstructed and contralateral normal knees

Posterior cruciate ligament (PCL) reconstruction for patients with PCL insufficiency has been associated with postoperative improvements in proprioceptive function due to mechanoreceptor regeneration. However, it is unclear whether reconstructed PCL or contralateral normal knees have better proprioceptive function outcomes. This meta-analysis was designed to compare the proprioceptive function of reconstructed PCL or contralateral normal knees in patients with PCL insufficiency. All studies that compared proprioceptive function, as assessed with threshold to detect passive movement (TTDPM) or joint position sense (JPS) in PCL reconstructed or contralateral normal knees were included. JPS was calculated by reproducing passive positioning (RPP). Five studies met the inclusion/exclusion criteria for the meta-analysis. The proprioceptive function, defined as TTDPM (95% CI: 0.25 to 0.51°; P<0.00001) and RPP (95% CI: 0.19 to 0.45°; P<0.00001), was significantly different between the reconstructed PCL and contralateral normal knees. The mean difference in angle of error between the reconstructed PCL and contralateral normal knees was 0.06° greater in TTDPM than by RPP. In addition, results from subgroup analyses, based on the starting angles and the moving directions of the knee, that evaluated TTDPM at 15° flexion to 45° extension, TTDPM at 45° flexion to 110° flexion, RPP in flexion, and RPP in extension demonstrated that mean angles of error were significantly greater, by 0.38° (P = 0.0001), 0.36° (P = 0.02), 0.36° (P<0.00001), and 0.23° (P = 0.04), respectively, in reconstructed PCL than in contralateral normal knees. The proprioceptive function of PCL reconstructed knees was decreased, compared with contralateral normal knees, as determined by both TTDPM and RPP. In addition, the amount of loss of proprioception was greater in TTDPM than in RPP, even with minute differences. Results from subgroup analysis, that evaluated the mean angles of error in moving directions through RPP, suggested that the moving direction of flexion has a significantly greater mean for angles of error than the moving direction of extension. Although the level of differences between various parameters were statistically significant, further studies are needed to determine whether the small differences (>1°) of the loss of proprioception are clinically relevant.

Performance: Bridging the Gap After ACL Surgery

PURPOSE OF REVIEW

The purpose of this paper is to identify strategies for a successful transition to sports in patients following rehabilitation for ACL reconstruction surgery (ACLR).

RECENT FINDINGS

Recent research continues to demonstrate a relatively low rate of return to previous level of play among athletes following ACLR combined with a significant risk of injury to either the ipsi or the contralateral ACL. Recent research also demonstrates a growing use of a varied battery of assessments to determine readiness to return to sport as well as a lack of consensus on the ideal rehabilitation program, the criteria for clearance for return to play (both in time from surgery and functional milestones), and the nature of a conditioning program designed specifically for transitioning the cleared athlete back to competition. Due to the lack of consensus and consistency regarding rehabilitation protocols and criteria for clearance to play after ACLR, deficits in strength, neuromuscular control, and psychological readiness may exist in "cleared" athletes. These deficits may not only negatively impact sports performance but also raise the risk of re-injury. Programs designed to successfully return an athlete to previous level of play should include not only strength and conditioning aimed at restoring fitness that was compromised as a result of the injury but also include attention to psychological readiness and address deficits in neuromuscular control. Problems that exist following ACLR cannot be solved by one professional; successful rehabilitation and return to play require a coordinated effort among the surgeon, physical therapist, athletic trainer, and fitness professional. Future research is needed to determine the optimal strategy to restore the neuromuscular control, functional strength, and psychological readiness necessary for a successful return to competition following ACLR.

Effects of Remnant Tissue Preservation on the Tendon Graft in Anterior Cruciate Ligament Reconstruction: A Biomechanical and Histological Study

BACKGROUND

There is controversy regarding the efficacy of remnant tissue preservation on graft healing in anterior cruciate ligament (ACL) reconstruction.

HYPOTHESIS

The preserved remnant tissue will (1) adhere to the graft surface and undergo a remodeling process, (2) accelerate graft revascularization, (3) increase the number of graft mechanoreceptors by 4 weeks, and (4) improve anteroposterior knee laxity and structural properties of the graft by 12 weeks.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-two sheep were randomly divided into 2 groups of 21 animals. In group I, the ACL was completely removed. In group II, the ACL was transected at the midsubstance but not debrided. ACL reconstruction was performed using a semitendinosus tendon autograft in both groups. Histological changes of the grafted tendon and the remnant tissue were evaluated at 4 and 12 weeks after surgery. Biomechanically, anterior translation and knee joint stiffness under an anterior drawer force and the structural properties of the femur-graft-tibia complex were evaluated.

RESULTS

The preserved remnant tissue was histologically distinct from the graft at 4 weeks, while the tissue partially adhered to the graft surface at 12 weeks. The ACL remnant tissue significantly accelerated revascularization in the grafted tendon at 4 weeks and significantly increased the number of mechanoreceptors at 4 and 12 weeks. In addition, remnant preservation significantly improved anterior translation (9.3 ± 2.1 mm and 5.4 ± 1.7 mm at 60° of knee flexion in groups I and II, respectively) and knee joint stiffness at 12 weeks. However, there were no significant differences in the structural properties between the 2 groups at 4 and 12 weeks after surgery.

CONCLUSION

Preservation of the ACL remnant tissue in ACL reconstruction enhanced cell proliferation, revascularization, and regeneration of proprioceptive organs in the reconstructed ACL and reduced anterior translation. However, remnant preservation did not improve the structural properties of the graft.

CLINICAL RELEVANCE

These results imply that preservation of the ACL remnant tissue may improve graft healing after ACL reconstruction.

Clinical results of anterior cruciate ligament reconstruction with ligament remnant tissue preservation: A systematic review

PURPOSE

To clarify the effects of ACL remnant tissue preservation on the clinical outcome of ACL reconstruction.

METHODS

This is a systematic review.

RESULTS

The majority of the reviewed articles suggested that remnant preservation significantly improved knee stability after ACL reconstruction, although there was some controversy. In addition, it was suggested that the degree of initial graft coverage significantly affected postoperative knee stability. Remnant preservation did not increase the occurrence rate of cyclops lesion.

CONCLUSION

Sufficient coverage of the graft with remnant tissue improves postoperative knee stability without any detrimental effects on the subjective and functional results.

Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction

[Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period.

Effects of knee bracing on postural control after anterior cruciate ligament rupture

STUDY DESIGN

Randomized clinical trial.

OBJECTIVES

To investigate the effects of functional knee braces on postural control in patients with anterior cruciate ligament (ACL) rupture.

BACKGROUND

ACL rupture leads to both mechanical knee instability and deficits in proprioception. Although elastic knee braces do not increase mechanical stability, patients report improved stability when wearing a brace. Elastic braces were found to reduce the loss of proprioception. It is, however, still unclear whether they also improve postural control, which involves the processing of proprioceptive input at a higher level.

METHODS

We studied 58 patients with isolated unilateral ACL rupture using computerized dynamic posturography and compared overall stability index (OSI) scores for injured and uninjured legs with and without a knee brace. In addition, patients were classified as copers and non-copers depending on knee function.

RESULTS

Within subjects, OSI scores were 3.0 ± 1.1° for uninjured legs when unbraced, 2.8±1.3° for uninjured legs when braced (p=0.17), 3.7 ± 1.5° for unbraced injured legs, and 2.9 ± 1.3° for braced injured legs (p<0.001). For the injured legs of copers and non-copers, OSI scores were 3.4° ± 1.2° for copers and 4.0° ± 1.6° for non-copers in the unbraced condition (p=0.11) and 2.7 ± 1.0° for copers and 3.1 ± 1.4° for non-copers in the braced condition (p=0.26).

CONCLUSION

Elastic knee braces increase postural stability by approximately 22% in patients with ACL rupture. There was no difference in postural stability between uninjured and injured legs in the braced condition. One possible explanation is that bracing improves both proprioception and postural control.

WITHDRAWN: Exercise for treating anterior cruciate ligament injuries in combination with collateral ligament and meniscal damage of the knee in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. The ACL may be damaged in isolation but often other ligaments and menisci are implicated. The injury may be managed surgically or conservatively. Injury causes pain, effusion and inflammation leading to alteration in muscle function. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the treatment of ACL injuries in combination with collateral ligament and meniscal damage to the knee in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2006), Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 3), MEDLINE (1996 to October 2006), EMBASE (1980 to October 2006), other databases and reference lists of articles.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised trials testing exercise programmes designed to treat adults with ACL injuries in combination with collateral ligament and meniscal damage. Included trials randomised participants to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Five trials (243 participants) evaluated different exercise programmes following ACL reconstruction and one trial (100 participants) compared supervised with self-monitored exercises as part of conservative treatment. No study compared the effect of exercise versus no exercise. Methodological quality scores varied considerably across the trials; participant and assessor blinding were poorly reported. Pooling of data was rarely possible due to the wide variety of comparisons, outcome measures and time points reported, and lack of appropriate data. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention over another. Further research should be considered in the form of large scale well-designed and well-reported randomised controlled trials with suitable outcome measures and surveillance periods. Suitable outcome measures should include a measure of functional outcome relevant to the individual.

WITHDRAWN: Exercise for treating isolated anterior cruciate ligament injuries in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. Injury causes pain, effusion and inflammation leading to the inability to fully activate the thigh muscles. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the rehabilitation of isolated ACL injuries in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (Feb 2005), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2005), MEDLINE (1996 to March 2005), EMBASE (1980 to March 2005), other databases and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials testing exercise programmes designed to rehabilitate adults with isolated ACL injuries. Trials where participants were randomised to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions, were included. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Nine trials involving 391 participants were included. Only two trials, involving 76 participants, reported conservative rehabilitation and seven trials, involving 315 participants, evaluated rehabilitation following ACL reconstruction. Methodological quality scores varied considerably across the trials, with the nature of participant and assessor blinding poorly reported. Trial comparisons fell into six categories. Pooling of data was rarely possible due to lack of appropriate data as well as the wide variety in outcome measures and time points reported. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention against another and the use of supplementary exercises in the management of isolated ACL injuries. Further research in the form of large scale well designed randomised controlled trials with suitable outcome measures and surveillance periods, using standardised reporting should be considered.

Dynamic assessment in patients following bone-patellar tendon-bone autograft anterior cruciate ligament reconstruction

Background:

The knee’s passive movement is insufficient to determine function in patients following ACL reconstruction.

Hypothesis:

We hypothesize that there are kinematic differences in the lower extremities (LE) during stair climbing and ground level walking following ACL surgery between the intact and reconstructed sides.

Study Design:

This was a retrospective cohort study. Eleven patients with an average age of 15.3 years at the time of their ACL reconstructive surgery (BPTB autograft) participated in the study.

Methods:

Patients were followed for at least 2 years post surgery. The subjects underwent a non-weight bearing ability test to reproduce predetermined knee joint positions. Their LE’s velocity and joint kinematics were then measured during level ground walking and on a set of custom designed stairs as they ascended and descended.

Results:

During level ground walking the maximum internal rotation at the ankle during the swing phase on the reconstructed side increased significantly from 2.3º to 19.9 º compared to the unreconstructed limb (P=0.04). The leading reconstructed knee during stair ascent exhibited less knee flexion as compared to the unreconstructed knee for each step (1^st step: 74.2º vs 81.5º; 2^nd step:93.6º vs 97.6º; 3^rd step: 48º vs 53.5º; 4^th step: 72.5º vs 78.1º; p<0.05).

Conclusions:

A two-year follow-up study in adolescents who had a bone-patellar tendon-bone autograft demonstrated that they had normal knee proprioception and 3D joint rotations of the LE, while showing an alteration of the ankle and knee kinematics during walking or ascending stairs.

Knee proprioception following ACL reconstruction; a prospective trial comparing hamstrings with bone-patellar tendon-bone autograft

We prospectively studied knee proprioception following ACL reconstruction in 40 patients (34 men and six women; mean age 31 years). The patients were allocated into two equal groups; group A underwent reconstruction using hamstrings autograft, and group B underwent reconstruction using bone-patellar tendon-bone autograft. Proprioception was assessed in flexion and extension by the joint position sense (JPS) at 15°, 45° and 75°, and time threshold to detection of passive motion (TTDPM) at 15° and 45°, preoperatively and at 3, 6 and 12 months postoperatively. The contralateral healthy knee was used as internal control. No statistical difference was found between the ACL-operated and the contralateral knees in JPS 15°, 45° and 75° at 6 and 12 months, in both study groups. No statistical difference was found between the ACL-operated and the contralateral knees in TTDPM 15° at 6 and 12 months, nor regarding TTDPM 45° at 3, 6 and 12 months, in group A. No statistical difference was found in JPS and TTDPM between the two grafts, at any time period. Knee proprioception returned to normal with ACL reconstruction at 6 months postoperatively, without any statistically significant difference between the autografts used.

Proprioception following partial meniscectomy in stable knees

PURPOSE

to investigate the proprioceptive function of patients with isolated meniscal tears of the knee before and after arthroscopic partial meniscectomy.

METHODS

one hundred subjects (50 patients who underwent a knee arthroscopy and 50 normal controls) were evaluated using single-leg dynamic postural stabilometry. All participants were assessed clinically and radiologically. Knee outcome scores were obtained for all subjects.

RESULTS

of the 50 patients arthroscoped, 34 were found to have meniscal tears. Twenty-nine of these patients were reassessed 3 months post-operatively. There was a significant proprioceptive deficit in subjects with meniscal tears when compared to their normal contra-lateral knee (P < 0.001) and the control group (P < 0.001). Partial meniscectomy resulted in a significant improvement in knee outcome scores but not proprioception measurements (n.s.).

CONCLUSION

patients with isolated meniscal tears were found to have a significant proprioceptive deficit which persisted following arthroscopic partial meniscectomy despite an otherwise successful clinical outcome.

New method of measuring wrist joint position sense avoiding cutaneous and visual inputs

BACKGROUND

Aspects of afferent inputs, generally termed proprioception, are being increasingly studied. Extraneous factors such as cutaneous inputs can dramatically interfere while trying to design studies in order to determine the participation of the different structures involved in proprioception in the wrist position sense. We tried to determine validity and repeatability of a new wrist joint position measurement device using methodology designed to minimize extraneous factors and isolate muscle and joint inputs.

METHODS

In order to test the reliability of the system, eighty young-adult subjects without musculoskeletal or neurologic impairments affecting the right upper extremity were tested using a custom made motion tracking system. Testing consisted of two conditions: active reproduction of active placement and passive reproduction of passive placement. Subjects performed two repetitions of each target position (10, 20, and 30 degrees of flexion and extension) presented in a random order. Test- retest reliability was then tested.

RESULTS

The average constant error in the passive condition was -0.7 degrees +/- 4.7 degrees as compared to the active condition at 3.7 degrees +/- 5.1 degrees. Average absolute error in the passive condition was 4.9 degrees +/- 2.9 degrees compared to the active condition in which absolute error was 5.9 degrees +/- 3.5 degrees.

DISCUSSION

Test-retest repeatability in both conditions was less than the 5 degrees magnitude typical of clinical goniometry. Errors in the active condition (less than 2 degrees ) were slightly smaller than the passive condition, and the passive condition was also associated with poorer consistency between apparatus sensors and skin sensors.

CONCLUSIONS

The current system for measurement of wrist joint proprioception allows the researcher to decrease extraneous influences that may affect joint position sense awareness, and will help in future study aiming to determine precisely the role of the different structure involved in proprioception.

Effect of anterior cruciate ligament injury and reconstruction on proprioceptive acuity of knee rotation in the transverse plane

BACKGROUND

Studies assessing proprioceptive acuity in anterior cruciate ligament (ACL)-deficient knees have only considered proprioception for knee movements in the sagittal plane rather than in the transverse plane (ie, rotation), despite the fact that the ACL plays a critical role in knee rotational stability and that the ACL is injured almost exclusively with a rotation mechanism. Therefore a test of proprioception is needed that involves movements similar to the mechanism of injury, in this case, rotation.

PURPOSE

To determine whether proprioceptive acuity in rotation changes after ACL injury and reconstruction, and to examine differences in proprioceptive acuity, range, laxity, and activity level among injured knees, contralateral knees, and healthy controls.

DESIGN

Cohort study; Level of evidence, 2.

METHODS

Proprioceptive acuity for active knee rotation movements, passive rotation range of motion, anterior knee laxity, and knee function were measured in 20 consecutive participants with unilateral ACL rupture and 20 matched controls. Reconstruction was performed using a single-incision technique with a 4-strand hamstring tendon autograft. Thirty participants (15 control and 15 ACL reconstructed) were retested at 3 months, and 14 with ACL reconstruction were tested at 6 months.

RESULTS

A deficit was found in preoperative knee rotation proprioception compared with healthy controls (P = .031). Three months after reconstruction, there was a significant improvement (P = .049) in proprioceptive acuity, single-plane anterior laxity (P = .01), and self-reported knee function (P = .001). At 3 months after reconstruction, proprioceptive acuity of the ACL-reconstructed knee was correlated with reported activity level (r = .63; P = .021).

CONCLUSION

Knee rotation proprioception is reduced in ACL-deficient participants compared with healthy controls. Three to 6 months after reconstruction, rotation proprioceptive acuity, laxity, and function were improved. While these findings are consistent with a return to previous activity level 6 months after reconstruction, the extent of graft maturation and restoration of kinematics should also inform the decision about return to sport.

Evaluating the center of gravity of dislocations in soccer players with and without reconstruction of the anterior cruciate ligament using a balance platform

OBJECTIVE

The objective of this study was to compare the dislocation of the center of gravity and postural balance in sedentary and recreational soccer players with and without anterior cruciate ligament (ACL) reconstruction using the Biodex Balance System (BBS).

METHOD

Sixty-four subjects were divided into three groups: a) soccer players who were post- anterior cruciate ligament reconstruction; b) soccer players with no anterior cruciate ligament injuries; and c) sedentary subjects. The subjects were submitted to functional stability tests using the Biodex Balance System. The instability protocols used were level eight (more stable) and level two (less stable). Three stability indexes were calculated: the anteroposterior stability index, the mediolateral stability index, and the general stability index.

RESULTS

Postural balance (dislocation) on the reconstructed side of the athletes was worse than on the side that had not undergone reconstruction. The postural balance of the sedentary group was dislocated less on both sides than the reconstructed knees of the athletes without anterior cruciate ligament injuries. There were no differences in postural balance with relation to left/right dominance for the uninjured athletes and the sedentary individuals.

CONCLUSION

The dislocation of the center of gravity and change in postural balance in sedentary individuals and on the operated limb of Surgery Group are less marked than in the soccer players from the Non Surgery Group and on the non-operated limbs. The dislocation of the center of gravity and the change in postural balance from the operated limb of the soccer players is less marked than in their non-operated limbs.

15-year follow-up of neuromuscular function in patients with unilateral nonreconstructed anterior cruciate ligament injury initially treated with rehabilitation and activity modification: a longitudinal prospective study

BACKGROUND

It has been suggested that neuromuscular function is of importance in the overall outcome after anterior cruciate ligament (ACL) injury.

HYPOTHESIS

Good neuromuscular function can be achieved and maintained over time in subjects with ACL injury treated with rehabilitation and activity modification but without reconstructive surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

One hundred consecutive patients (42 women and 58 men) with acute ACL injury at a nonprofessional, recreational or competitive activity level were assessed 1, 3, and 15 years after injury. Their mean age at inclusion was 26 years (range, 15-43 years). All patients initially underwent rehabilitation and were advised to modify their activity level, especially by avoiding contact sports. Patients with recurrent giving-way episodes or secondary meniscal injuries that required fixation were subsequently excluded and underwent reconstruction of the ACL. Sixty-seven patients (71% of those available for follow-up) with unilateral nonreconstructed injury remained at the 15-year follow-up. Fifty-six of these 67 patients were examined with the single-legged hop test for distance and knee muscle strength. The limb symmetry index (LSI), calculated by dividing the result for the injured leg by that of the uninjured leg and multiplying by 100, was used for comparisons over time (paired t test).

RESULTS

The LSI for the single-legged hop test was higher at the 3-year follow-up (mean, 98.5%; standard deviation [SD], 7.6%) than at the 15-year follow-up (mean, 94.8%; SD, 10.5%) (mean difference, -3.7%; 95% confidence interval [CI], -6.1% to -1.2%; P = .004). The LSI for isometric extension was higher at the 15-year follow-up (mean, 97.2%; SD, 13.7%) than at the 1-year follow-up (mean, 88.2%; SD, 15.4%) (mean difference, 9.0%; 95% CI, 3.7% to 14.4%; P = .001). At the 15-year follow-up, between 69% and 85% of the patients had an LSI >or= 90%.

CONCLUSIONS

Good functional performance and knee muscle strength can be achieved and maintained over time in the majority of patients with ACL injury treated with rehabilitation and early activity modification but without reconstructive surgery.

Proprioceptive comparison of allograft and autograft anterior cruciate ligament reconstructions

The aim of this study is to search if there is any proprioceptive difference between auto and allograft anterior cruciate ligament (ACL) reconstructions, and also to determine if there is any relationship between instrumented anterior knee laxity and proprioception after an ACL reconstruction. The following four groups were constituted for this purpose: group I, control group; group II, autograft reconstructions; group III, allograft reconstructions and group IV, people with injured ACLs. Each group consisted of 20 patients/volunteers. Two subgroups were constituted according to the findings of KT-1,000 laxity testing in group II and III; patients/volunteers found to have a laxity of 3 mm or less were enrolled in the normal subgroup and those with a laxity of more than 3 mm were enrolled in the lax subgroup. Two proprioceptive tests were used: threshold to detect passive motion (TDPM) and joint position sense (JPS) by using Cybex Norm dynamometer. Patients underwent ten tests and the discrepancy in degrees was averaged for ten trials. Comparisons were made to evaluate the proprioceptive differences between groups/subgroups; ANOVA and t test was used for comparisons where appropriate, and the significance was set at P < 0.05. There was a significant difference in degrees between patients with injured ACLs and the other three groups in TDPM evaluations (injured: 1.93 degrees vs. control: 1.03 degrees , autograft: 1.01 degrees , allograft: 0.96 degrees ; P < 0.001). Auto and allograft reconstructions were not different from each other and controls. Allo and autograft ACL reconstructions are not different from each other according to proprioceptive measurements. Also, proprioception is not correlated to postoperative anterior knee laxity; many variables involve joint proprioception and mostly the anterior knee laxity may not be the sole determining element, and a lax ACL still may fulfill some of its afferent arc functions as long as it bridges the femur and tibia.

Design of a knee rotatory kinaesthetic device

The anterior cruciate ligament (ACL) constrains rotatory motion at the knee and is commonly injured during rotational movements in athletic activity. This densely innervated ligament is assumed to play a role in knee proprioception, however, no study has measured proprioception in a manner relevant to either the kinematics of the ligament or the mechanism of injury, partly because of a lack of suitable equipment. The aims of this technical note are to document the development of a novel knee rotatory kinaesthetic device, and to present details of its construction, reproducibility, accuracy and application. The purpose-built device allows rotational movements at the knee to occur with minimal frictional resistance and provides accurate limits to the magnitude of these movements. This allows analysis of subjects' ability to discriminate between movements of differing magnitudes and thus allows calculation of subjects' sensitivity to small differences in magnitude of active knee rotation. Measurements taken with the device had a high level of agreement with those of a calibrated digital inclinometer (ICC=0.99; 95% CI 0.88 to 0.99) with a mean error of 0.24 degrees . The device also demonstrated excellent reproducibility (Pearson's r=1.0). A single case study is presented to detail the clinical application of the device. This novel device allows subjects to perform active knee rotational movements in a closed kinetic chain with discrete, self-paced movement, enabling calculation of movement discrimination. The device is compact and portable enabling testing to be undertaken in remote settings enhancing its clinical applicability.

Exercise for treating anterior cruciate ligament injuries in combination with collateral ligament and meniscal damage of the knee in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. The ACL may be damaged in isolation but often other ligaments and menisci are implicated. The injury may be managed surgically or conservatively. Injury causes pain, effusion and inflammation leading to alteration in muscle function. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the treatment of ACL injuries in combination with collateral ligament and meniscal damage to the knee in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2006), Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 3), MEDLINE (1996 to October 2006), EMBASE (1980 to October 2006), other databases and reference lists of articles.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised trials testing exercise programmes designed to treat adults with ACL injuries in combination with collateral ligament and meniscal damage. Included trials randomised participants to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Five trials (243 participants) evaluated different exercise programmes following ACL reconstruction and one trial (100 participants) compared supervised with self-monitored exercises as part of conservative treatment. No study compared the effect of exercise versus no exercise. Methodological quality scores varied considerably across the trials; participant and assessor blinding were poorly reported. Pooling of data was rarely possible due to the wide variety of comparisons, outcome measures and time points reported, and lack of appropriate data. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention over another. Further research should be considered in the form of large scale well-designed and well-reported randomised controlled trials with suitable outcome measures and surveillance periods. Suitable outcome measures should include a measure of functional outcome relevant to the individual.

Proprioceptive skills and functional outcome after anterior cruciate ligament reconstruction with a bone-tendon-bone graft

Several studies have shown that patients with anterior cruciate ligament (ACL) reconstruction have an improved proprioceptive function compared to subjects with ACL-deficient knees. The measurement of functional scores and proprioception potentially provides clinicians with more information on the status of the ACL-reconstructed knees. To evaluate proprioception in patients following ACL reconstruction with a bone-tendon-bone (BTB) graft, we used the angle reproduction in the sitting, lying and standing positions and the one-leg hop test. Forty-five patients between 19 and 52 years of age were investigated in a 36-month period after the operation. For functional performance measurement, the International Knee Documentation Committee (IKDC) score was used. Very good and good results were seen in 95% of cases. All patients returned to the same activity level as seen before ACL repair. There was a significant difference in the active angle reproduction test between the ACL-reconstructed knees and normal knees in the active sitting position. Tests with passive angle adjustment in the sitting, lying and active standing positions did not show any differences in proprioceptive skills. Good to very good results in the one-leg hop test we found in 95% of patients. After ACL reconstruction, deficiencies in the active angle reproduction test were very small but, nevertheless, were still observed. Overall, the functional and proprioceptive outcomes demonstrate results to recommend the procedure.

A prospective study of 3-day versus 2-week immobilization period after anterior cruciate ligament reconstruction

BACKGROUND

Aggressive early rehabilitation is recommended after reconstruction of the anterior cruciate ligament (ACL) using a patellar tendon-bone graft. However, rehabilitation after reconstruction of ACL using the multistranded hamstring is controversial. In this study, we compared the clinical results of 3-day immobilization after reconstruction of ACL using the multistranded hamstring, with those of 2-week immobilization prospectively.

METHODS

A total of 30 consecutive patients with ruptured ACL underwent single-socket ACL reconstruction. 10 male and 5 female patients (mean age of 29.2+/-10.0 years) were prospectively randomized for a 3-day immobilization period, and 6 male and 9 female patients (mean age of 27.3+/-10.9 years) were randomized for a 2-week immobilization period. We measured the anterior laxity with a KT-2000 arthrometer, joint position sense, and thigh muscle strength at 3, 6 and 12 months after surgery.

RESULTS AND CONCLUSIONS

There were no statistically significant differences between the two groups. We concluded that the post-operative 3-day immobilization period is preferable to the longer 2-week period in our rehabilitation program from the viewpoint of psychological load to the patients and the duration of hospitalization after ACL reconstruction using multistranded hamstring tendons.

Temporal change of joint position sense after posterior cruciate ligament reconstruction using multi-stranded hamstring tendons

A total of 29 patients who had undergone posterior cruciate ligament (PCL) reconstruction using multi-stranded hamstring tendons were prospectively followed-up for joint stability and proprioceptive function at a minimum of 24 months after surgery. We measured temporal changes of the posterior laxity by stress radiography and the KT-2000 arthrometer, and we also measured joint position sense for an average of 42 months (range 24-78 months). In terms of results, improvement of joint stability was observed postoperatively and maintained over 2 years after PCL reconstruction, although posterior stability in the reconstructed knee was not identical to the contralateral normal knee. Although joint position sense worsened just after reconstruction, it gradually recovered from 18 months after surgery. However, proprioceptive function after PCL reconstruction did not recover to the same level as in the contralateral normal knee even over 24 months after surgery.

Muscular compensation and lesion of the anterior cruciate ligament: contribution of the soleus muscle during recovery from a forward fall

BACKGROUND

Knee stability following an anterior cruciate ligament lesion has been widely studied. Only recent studies focused on the contribution of the soleus muscle. Our purpose was to characterize the dynamic and muscular activity of balance recovery in healthy subjects and patients with an anterior cruciate ligament rupture. The role of the soleus was investigated in the ipsilateral compensation developed to stabilize the knee and in the contralateral compensation to recover balance.

METHODS

Twelve anterior cruciate ligament deficient patients, ten anterior cruciate ligament repaired patients and 14 control subjects were recorded during a forward fall involving stepping to recover balance.

FINDINGS

The dynamic of the centre of gravity remained normal when compared to the control group regardless of the treatment, suggesting an adapted compensation to knee instability in this situation. A bilateral increase in soleus activity was related to an increased duration in the balance recovery process in all patients. Patients used one of two strategies to recover balance regardless of the treatment: reducing the step length, involving an early recruitment of the soleus before heel contact, or anticipating braking with a similar step length requiring a predominant activity of the hamstrings.

INTERPRETATIONS

These results suggest that bilateral activity of the soleus is involved to compensate for instability and highlight the contribution of the soleus to rehabilitation after an anterior cruciate ligament lesion, not only as a compensatory muscle acting at the knee level but also at a higher level in the bilateral control of stance.

Decrease in anterior knee laxity by electrical stimulation of normal and reconstructed anterior cruciate ligaments

We have investigated the changes in anterior laxity of the knee in response to direct electrical stimulation of eight normal and 45 reconstructed anterior cruciate ligaments (ACLs). In the latter, the mean time from reconstruction was 26.7 months (24 to 32). The ACL was stimulated electrically using a bipolar electrode probe during arthroscopy. Anterior laxity was examined with the knee flexed at 20 degrees under a force of 134 N applied anteriorly to the tibia using the KT-2000 knee arthrometer before, during and after electrical stimulation. Anterior tibial translation in eight normal and 17 ACL-reconstructed knees was significantly decreased during stimulation, compared with that before stimulation. In 28 knees with reconstruction of the ACL, in 22 of which the grafts were found to have detectable somatosensory evoked potentials during stimulation, anterior tibial translation was not decreased. These findings suggest that the ACL-hamstring reflex arc in normal knees may contribute to the functional stability and that this may not be fully restored after some reconstructions of the ACL.

Exercise for treating isolated anterior cruciate ligament injuries in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. Injury causes pain, effusion and inflammation leading to the inability to fully activate the thigh muscles. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the rehabilitation of isolated ACL injuries in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PEDro - The Physiotherapy Evidence Database, CINAHL, AMED, and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials testing exercise programmes designed to rehabilitate adults with isolated ACL injuries. Trials where participants were randomised to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

All trials judged to have met the inclusion criteria were independently assessed for methodological quality by use of a 15 point checklist. Pairs of authors independently extracted data. For each study, relative risk and 95% confidence intervals were calculated for dichotomous outcomes and mean differences and 95% confidence intervals calculated for continuous outcomes.

MAIN RESULTS

Nine trials, involving 391 participants met the inclusion criteria of the review. Only two trials, involving 76 participants, reported conservative rehabilitation and seven trials, involving 315 participants, evaluated rehabilitation following ACL reconstruction. Methodological quality scores varied considerably across the trials, with the nature of participant and assessor blinding poorly reported. Trial comparisons fell into six categories. Pooling of data was rarely possible due to lack of appropriate data as well as the wide variety in outcome measures and time points reported. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention against another and the use of supplementary exercises in the management of isolated ACL injuries. Further research in the form of large scale well designed randomised controlled trials with suitable outcome measures and surveillance periods, using standardised reporting should be considered.

Weight Discrimination After Anterior Cruciate Ligament Injury: A Pilot Study

OBJECTIVE

To determine whether the ability to discriminate weights remained accurate after anterior cruciate ligament (ACL) injury.

DESIGN

Descriptive case series.

SETTING

Outpatient physical therapy.

PARTICIPANTS

Convenience sample of 10 participants with unilateral ACL injuries (age, 27.1+/-8.2 y) and 8 healthy controls (age, 22.6+/-2.8 y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Weber fractions, expressed as percentage differences from the standard weight (3.00 kg) that could be reliably detected (75% correct level), were derived from each leg to provide an index of proprioceptive acuity for weight discrimination. Subjective ratings of knee function (Activities of Daily Living Scale of the Knee Outcome Survey) and measurements of quadriceps strength (peak isometric torque).

RESULTS

The ACL group exhibited a reduced acuity to detect differences in weight on the injured, as compared with the uninjured, side as reflected in the increase in Weber fractions (mean, 6.7%+/-2.3% vs 4.8%+/-1.1%, respectively; P = .043). No such difference in acuity between legs was detected in healthy controls (mean right and left, 5.4%+/-1.4% vs 5.7%+/-1.3%, respectively, P = .99).

CONCLUSIONS

Proprioceptive acuity for weight discrimination was significantly reduced after an ACL injury, possibly reflecting deficits in the ability to properly calibrate force signals generated while muscles are actively contracting, as a result of a loss in ligamentous sensory innervation.

Proprioceptive recovery of patients with cervical myelopathy after surgical decompression

STUDY DESIGN

A prospective observational study.

OBJECTIVES

To determine whether proprioceptive deficit recovers after surgery and whether proprioceptive evaluation can predict functional outcome in cervical myelopathy patients.

SUMMARY OF BACKGROUND DATA

Proprioceptive sensation plays an important role in smooth, coordinated movement of the limbs. Information about proprioception ascends through the dorsal columns in the spinal cord. In severe compressive myelopathy, proprioceptive ability would be reduced and could be improved after surgical decompression. However, there have been few studies concerning proprioceptive impairment in cervical myelopathy.

MATERIALS AND METHODS

The study group included 26 cervical myelopathy patients who underwent posterior surgical decompression. Knee proprioception was assessed by joint position sense, which was evaluated by measuring the error angle when the subjects tried to reproduce the predetermined angle by extension and by flexion. Proprioceptive deficit in the study group was evaluated, compared with age-matched normal subjects. Postoperative recovery and correlation to functional status was analyzed in the study group. The Japanese Orthopedic Association (JOA) scores were used for functional evaluation.

RESULTS

The error angles were significantly higher in the study group than those in the control group before surgery. All patients in the study group finally had improvement of the error angles by a year after surgery. The average of error angles in the study group was improved 2 weeks after surgery; however, no changes were observed later. There was significant correlation between the improvement rate of the error angles 2 weeks after surgery and that of the JOA scores 2 years after surgery. There were 9 patients who had worsened proprioception 2 weeks after surgery either by extension or by flexion, all of whom had poor functional outcome.

CONCLUSIONS

Knee proprioception was impaired in cervical myelopathy and recovered after surgical posterior decompression. Proprioceptive improvement at 2 weeks correlates with the degree of improvement in JOA scores at 2 years after surgery.

Knee proprioception in patients with osteosarcoma around the knee after modular endoprosthetic reconstruction

BACKGROUND

Proprioception as an outcome for patients with osteosarcoma who have undergone modular endoprosthetic knee reconstruction has not been studied, as far as we know. The primary purpose of the present study was to understand the differences in knee proprioception between this patient population and control subjects. We also compared differences in proprioception between patients with tumors at different sites and between patients who had different proportions of bone length excised.

METHODS

We evaluated twenty patients who had undergone a wide resection of a tumor about the knee followed by reconstruction with a modular endoprosthesis. The mean age of the patients was 21.7 years. The patients were grouped according to tumor site, i.e., the distal part of the femur or the proximal part of the tibia; they were also grouped according to the length of resected bone (<40% or >or=40% of the length of the bone). Another twenty age-matched control subjects were recruited for this study. Knee proprioception was evaluated by comparing active and passive angular repositioning of the involved limb and the normal limb in the patients and the dominant limb in the central subjects.

RESULTS

The absolute matching error of active and passive repositioning was 2.7 degrees +/- 2.1 degrees and 2.9 degrees +/- 2.2 degrees , respectively, for knees treated operatively and 3.2 degrees +/- 2.1 degrees and 2.1 degrees +/- 1.3 degrees , respectively, for the dominant knees in the control subjects. The differences between the operatively treated knees and the control knees were not significant (p > 0.05). There was also no significant difference in proprioception between the patients with a distal femoral tumor and those with a proximal tibial tumor (p > 0.05). The proprioception of the patients with a greater length of bone resected was significantly worse in both lower extremities than that of patients with a shorter resected length (p = 0.016 for the normal side and p = 0.025 for the involved side).

CONCLUSIONS

The proprioception of the involved knees in the patients with osteosarcoma who had modular endoprosthetic reconstruction was not found to be different from the normal knees or the knees in the control subjects. On the basis of our data, we found that proprioception is probably not influenced by the tumor site. Conversely, resection length appears to be an important factor. These study findings may be used as a reference for knee proprioception in patients with osteosarcoma who have a modular endoprosthetic knee reconstruction.

Impaired joint proprioception in patients with cervical myelopathy

STUDY DESIGN

Prospective clinical study.

OBJECTIVES

To evaluate impairment of proprioception quantitatively in patients with cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Sensory information regarding proprioception ascends through the posterior columns in the spinal cord. Damage to these columns causes proprioceptive loss in patients with spondylotic myelopathy. Nevertheless, there have been few studies regarding proprioception in patients with myelopathy.

METHODS

The authors evaluated knee proprioception in 54 cervical myelopathy patients and compared results with those of 54 age-matched healthy volunteers. Knee proprioception was assessed by joint position sense, represented by the error angles when patients reproduced predetermined angles of knee flexion.

RESULTS

The average absolute angle error of right and left knee with the predetermined position of 30 degrees of knee flexion was 2.5 +/- 1.8 (mean +/- standard deviation) and 1.8 +/- 1.2 degrees and with the predetermined 60 degrees of flexion, 4.7 +/- 2.8 and 2.8 +/- 1.4 degrees in the myelopathy and control groups, respectively. The average absolute angular errors in the myelopathy group were significantly higher than those in the control group for each predetermined knee position (P < 0.01).

CONCLUSIONS

Proprioceptive ability is impaired in patients with cervical myelopathy. Position sense can be assessed by measuring the angular error when reproducing criterion positions, and the results may reflect the severity of cervical myelopathy. Thus, the present method of measuring proprioception is easy to perform and useful for quantitative assessment of the severity of cervical myelopathy.

Tibiofemoral kinematics following successful anterior cruciate ligament reconstruction using dynamic multiple resonance imaging

BACKGROUND

The aim of anterior cruciate ligament reconstruction is to reduce excess joint laxity, hoping to restore normal tibiofemoral kinematics and therefore improve joint stability. It remains unclear if successful ACL reconstruction restores normal tibiofemoral kinematics and whether it is this that is associated with a good result.

STUDY

Case series.

PURPOSE

To assess the kinematics of the anterior cruciate ligament-reconstructed knee using open-access MRI.

METHODS

Tibiofemoral motion was assessed using open-access MRI, weightbearing through the arc of flexion from 0 degrees to 90 degrees in 10 patients with isolated reconstruction of the anterior cruciate ligament (hamstring autograft) in one knee and a normal contralateral knee. Midmedial and midlateral sagittal images were analyzed in all positions of flexion in both knees to assess the tibiofemoral relationship. Sagittal laxity was also assessed by performing the Lachman test while the knees were scanned dynamically using open-access MRI.

RESULTS

The amount of excursion between the tibial and femoral joint surfaces was similar between the normal and reconstructed knees, but the relationship of tibia to femur was always different for each position of knee flexion assessed-the lateral tibia being about 5 mm more anterior in the anterior cruciate ligament-reconstructed knees. This anterior tibial position is statistically significantly different at 0 degrees (P <.0006), 20 degrees (P =.0004), 45 degrees (P =.002), and 90 degrees of flexion (P <.006). Anteroposterior laxity was similar between normal and anterior cruciate ligament-reconstructed knees.

CONCLUSION

Anterior cruciate ligament reconstruction reduces sagittal laxity to within normal limits but does not restore normal tibiofemoral kinematics despite a successful outcome.

Dynamic upper limb proprioception in multidirectional shoulder instability

The ability of subjects with multidirectional shoulder instability to use proprioception to complete a series of upper limb repositioning tasks was investigated. Twelve subjects with multidirectional instability and 12 control subjects were blindfolded and instructed to use proprioception to reproduce a self-selected target position as accurately as possible. Subjects completed 10 repetitions for each limb using three distinct upper limb movements: overhead reaching, scapular plane pointing, and humeral external rotation with abduction. A three-dimensional video motion analysis system tracked limb position and determined spatial hand position error. Subjects with multidirectional shoulder instability showed significantly greater hand position error than control subjects. No hand position error differences were found between the symptomatic and the asymptomatic limbs of subjects in the instability group. Inter-repetition error for subjects in both groups improved significantly during the first three movement cycles. These results suggest that after movement initiation, dynamic proprioception was a factor in improving hand position accuracy in both groups, but to a lesser degree in subjects with multidirectional instability. Consequently, subjects with multidirectional instability may have a reduced capacity to use proprioception to refine and control the motor output of the upper limb.

Effect of fatigue on knee proprioception: implications for dynamic stabilization

The high incidence of injuries that occur later during a session of sports or recreational activities suggests that fatigue may contribute to altered neuromuscular control of the lower limb and an individual's subsequent altered ability to dynamically stabilize the knee joint. One possible mechanism is a fatigue-mediated alteration in proprioception. This paper reviews experimental evidence of fatigue-induced changes in knee joint position sense and movement sense, or kinesthesia. We will discuss the possible physiological mechanisms behind these changes, including the role of joint and muscle receptors in proprioception and neuromuscular control of the knee, and the role of fatigue in changes in afferent output from muscle and joint receptors. We will then explore the implications that alteration in proprioception may have for dynamic stabilization of the knee joint.