Non-injured Knee Research Articles

Assessment of knee instability in ACL-injured knees using weight-bearing computed tomography (WBCT): a novel protocol and preliminary results.

To propose a protocol for assessing knee instability in ACL-injured knees using weight-bearing computed tomography (WBCT). We enrolled five patients with unilateral chronic ACL tears referred for WBCT. Bilateral images were obtained in four positions: bilateral knee extension, bilateral knee flexion, single-leg stance with knee flexion and external rotation, and single-leg stance with knee flexion and internal rotation. The radiation dose, time for protocol acquisition, and patients' tolerance of the procedure were recorded. A blinded senior radiologist assessed image quality and measured the anterior tibial translation (ATT) and femorotibial rotation (FTR) angle in the ACL-deficient and contralateral healthy knee. All five patients were male, aged 23-30 years old. The protocol resulted in a 16.2 mGy radiation dose and a 15-min acquisition time. The procedure was well-tolerated, and patient positioning was uneventful, providing good-quality images. In all positions, the mean ATT and FTR were greater in ACL-deficient knees versus the healthy knee, with more pronounced differences observed in the bilateral knee flexion position. Mean lateral ATT in the flexion position was 9.1±2.8 cm in the ACL-injured knees versus 4.0±1.8 cm in non-injured knees, and mean FTR angle in the bilateral flexion position was 13.5°±7.7 and 8.6°±4.6 in the injured and non-injured knees, respectively. Our protocol quantitatively assesses knee instability with WBCT, measuring ATT and FTR in diverse knee positions. It employs reasonable radiation, is fast, well-tolerated, and yields high-quality images. Preliminary findings suggest ACL-deficient knees show elevated ATT and FTR, particularly in the 30° flexion position.

Chondral Injury Associated With ACL Injury: Assessing Progressive Chondral Degeneration With Morphologic and Quantitative MRI Techniques.

Anterior cruciate ligament (ACL) injuries are associated with a risk of post-traumatic osteoarthritis due to chondral damage. Magnetic resonance imaging (MRI) techniques provide excellent visualization and assessment of cartilage and can detect subtle and early chondral damage. This is often preceding clinical and radiographic post-traumatic osteoarthritis. Morphologic and quantitative MRI techniques can assess early and progressive degenerative chondral changes after acute ACL injury. Prospective longitudinal cohort. Level 3. Sixty-five participants with acute unilateral ACL injuries underwent bilateral knee MRI scans within 1 month of injury. Fifty-seven participants presented at 6 months, while 54 were evaluated at 12 months. MRI morphologic evaluation using a modified Noyes score assessed cartilage signal alteration, chondral damage, and subchondral bone status. Quantitative T1ρ and T2 mapping at standardized anatomic locations in both knees was assessed. Participant-reported outcomes at follow-up time points were recorded. Baseline Noyes scores of MRI detectable cartilage damage were highest in the injured knee lateral tibial plateau (mean 2.5, standard error (SE) 0.20, P < 0.01), followed by lateral femoral condyle (mean 2.1, SE 0.18, P < 0.01), which progressed after 1 year. Longitudinal prolongation at 12 months in the injured knees was significant for T1ρ affecting the medial and lateral femoral condyles (P < 0.01) and trochlea (P < 0.01), whereas T2 values were prolonged for medial and lateral femoral condyles (P < 0.01) and trochlea (P < 0.01). The contralateral noninjured knees also demonstrated T1ρ and T2 prolongation in the medial and lateral compartment chondral subdivisions. Progressive chondral damage occurred despite improved patient-reported outcomes. After ACL injury, initial and sustained chondral damage predominantly affects the lateral tibiofemoral compartment, but longitudinal chondral degeneration also occurred in other compartments of the injured and contralateral knee. Early identification of chondral degeneration post-ACL injury using morphological and quantitative MRI techniques could enable interventions to be implemented early to prevent or delay PTOA.

Tibial Slope on Conventional Lateral Radiographs in Anterior Cruciate Ligament–Injured and Intact Knees: Mean Value and Outliers

Background: An increased tibial slope (TS) has been identified as a risk factor for anterior cruciate ligament (ACL) injury and graft failure after ACL reconstruction. However, different imaging modalities are used to determine the TS, resulting in divergent values. Consequently, no reference values and no consensus on thresholds can be reached, which in turn is mandatory for indicating correction osteotomies when facing outlier TS. Purpose: To determine the mean values of the TS and the incidence of their outliers in large cohorts of patients with ACL-injured and noninjured knees and to determine the feasibility of measuring TS on conventional lateral radiographs (CLRs). Study Design: Cross-sectional study; Level of evidence 3. Methods: TS of ACL-injured knees (n = 1000, group A) and ACL-intact knees (n = 1000, group B) was measured by 3 experienced examiners. Medial TS was measured on CLRs using the technique of Dejour and Bonnin. Patients with radiographs with poor image quality, osteoarthritis, previous osteotomies, or nondigital radiographs were excluded. The intra- and interrater reliability was calculated using the intraclass correlation coefficient. Results: The mean TS was significantly higher in group A than in group B (10.04°± 3° [range, 2°-22°] vs 9.02°± 2.9° [range, 1°-18°], respectively; P < .001). Significantly more participants in group A had TS larger than 12° (≥12°, 32.2% vs 19.8%, P < .001; ≥13°, 20.9% vs 11.1%, P < .001; ≥14°, 13.5% vs 5.7%, P < .001; ≥15°, 8% vs 2.7%, P < .001; ≥16°, 3.7% vs 1.4%, P = .0005), respectively. In contrast, significantly more participatns in group B had TS 8° or less (≤8°, 32.1% vs 42.7%, P < .001; ≤7°, 20% vs 30.9%, P < .001; ≤6°, 12.4% vs 19.8%, P < .001; ≤5°, 6.6% vs 12%, P = .0003; ≤4°, 2.8% vs 5.3%, P = .0045). The intraclass correlation coefficient revealed a good to excellent reliability throughout measurements. Conclusion: Median values for the TS were 9° for uninjured and 10° for ACL-injured knees on CLRs. Notwithstanding its statistical significance, this finding might be negligible in clinical practice. However, a significantly larger number of outliers were found in the ACL-injured group exceeding a TS of 12° and demonstrating an incremental proportion with increasing TS, serving as a potential threshold for correction osteotomy. Furthermore, CLRs in the largest cohort to date exhibited high reproducibility, proving the feasibility of CLRs as a routine measurement for TS.

Association of Traumatic Knee Injury With Radiographic Evidence of Knee Osteoarthritis in Military Officers.

The association between knee injury and knee osteoarthritis (OA) is understudied relative to its importance, particularly in younger populations. This study was undertaken to examine the association of knee injury with radiographic features of knee OA in military officers, who have a physically demanding profession and high rates of knee injury. Participants were recruited in 2015-2017 from an existing program that enrolled 6,452 military officers during 2004-2009. Officers with a history of knee ligament or meniscal injuries (n=117 via medical record review) were compared to officers with no history of knee injury (n=143). Bilateral posteroanterior knee radiographs were obtained using a standardized fixed-flexion positioning frame. All images were read for Kellgren/Lawrence (K/L) grade, osteophyte (OST), and joint space narrowing (JSN) scores. Data were analyzed using linear-risk regression models with generalized estimating equations. Injured and noninjured participants were similar (mean age 28 years, mean body mass index 25 kg/m2 , ~40% female). The mean time from first knee injury to imaging among injured participants was 9.2 years. Compared with noninjured knees, greater prevalence of radiographic OA (K/L grade ≥ 2), OST (grade ≥ 1), and JSN (grade ≥ 1) was observed among injured knees, with prevalence differences of +16% (95% confidence interval [95% CI] 10%, 22%), +29% (95% CI 20%, 38%), and + 17% (95% CI 10%, 24%), respectively. Approximately 1 in 6 officers with prior knee injury progressed to radiographic OA by age 30 years. At the midpoint of a projected 20-year military career, officers with a history of traumatic knee injury have a markedly increased prevalence of knee radiographic OA compared to officers without injury.

Three-Dimensional Orientation of the Native Anterior Cruciate Ligament in Magnetic Resonance Imaging.

The aim of this study was to describe the three-dimensional orientation of the native anterior cruciate ligament (ACL) in magnetic resonance imaging (MRI) by calculating the angles of inclination in relation to the axial plane which is given for the knee joint line in a group of healthy individuals. These could help to establish guidelines that may be used for the surgical positioning of bone tunnels during ACL reconstruction. A total of 290 MRI scans of patients with integrity of the ACL were evaluated; three observers identified the coordinates of the femoral and tibial insertion sites, then it is defined the vector and evaluated its angles with respect to axial axis and calculated the angles with trigonometric equations. The data were analyzed according to the age, sex, side, BMI, and height of the patients, and the interobserver reliability was calculated. The patient demographics were as follows: age average: 45 years old, BMI average: 27.1, 54% right knees, and 60% female. The average angle for all the measurements was 76.95 degrees (SD ± 6.8 degrees) in the sagittal plane, 81.65 degrees (SD ± 7.79 degrees) in the coronal plane and 33.17 degrees (SD ± 4.98 degrees) in the axial plane. No statistically significant differences were found between the categorical variables mentioned; moderate to substantial interobserver reliability strength was found with an average kappa of 0.791 for all measurements. The three-dimensional orientation of the native ACL in a group of healthy individuals was established. The findings can be helpful for performing anatomical reconstructions of the ACL in injured patients using as reference the average calculated angles, or measure of the contralateral non-injured knee for surgical planning; these results serve as a basis for the design of a technique that optimizes the three-dimensional position of the ACL when it undergoes reconstruction in the trend toward greater precision for better functional results. Biomechanical and clinical-surgical studies are required to further evaluate our results.

Does posterior tibial slope laterality exist? A matched cohort study between ACL-injured and non-injured knees

PurposeThe purpose of this study is to examine 1) the degree and frequency of laterality in posterior tibial slope (PTS) with control and anterior cruciate ligament (ACL) injury groups and 2) the laterality of PTS between sides of injury and dominant legs in patients with primary ACL injuries.MethodsA total of 187 consecutive patients with clinically diagnosed noncontact ACL injuries and an age- and sex-matched 1:1 control group were identified. PTS was measured using three different methods (aPTS = anterior PTS, mPTS = middle PTS, pPTS = posterior PTS) on a lateral knee radiograph. PTS of the left and right sides were compared between the patients in the control and ACL-injured groups, and between the injured and non-injured and dominant and non-dominant legs among the patients in the ACL-injured group. The patients with a difference in PTS of ≥ 3° in mPTS were selected. The percentages were compared between left and right between and among both groups, and between the injured and non-injured, and non-dominant and dominant leg, for the ACL group. Multiple regression analysis was performed to analyze the factors influencing the degree of mPTS.ResultsBoth control (Right vs Left: aPTS; 9.0 ± 2.5 vs 10.5 ± 3.0, mPTS; 6.6 ± 2.3 vs 8.1 ± 2.7, pPTS; 4.0 ± 2.4 vs 5.6 ± 2.8, respectively, p < 0.01) and ACL injury groups (Right vs Left: aPTS; 10.6 ± 3.0 vs 12.6 ± 2.9, mPTS; 7.6 ± 2.6 vs 9.5 ± 2.6, pPTS; 5.9 ± 3.0 vs 8.0 ± 3.0, respectively, p < 0.01) had a significantly greater PTS on the left than on the right side, and the ACL group had a significantly greater PTS than the control group on both the left and right sides. In the ACL group, PTS was greater on the injured and the non-dominant leg than on the non-injured and the dominant leg. The percentage of patients with a PTS difference of ≥ 3° was significantly greater on the left, injured, and non-dominant leg (95.3% vs 4.7%, 73.8% vs 26.2%, 86.1% vs 13.9%, respectively, p < 0.01). Only the left leg had a significant influence on PTS in the multivariate analysis.ConclusionThere was laterality in PTS within control and ACL injury groups, and this information is of benefit for effective treatment of ACL injuries.Level of evidenceLevel III.

Low-Profile Modifications of the Losee Pivot Shift Test for Assessment of an ACL-Deficient Knee in the Awake Patient

Background: Pivot shift test results have demonstrated widely inconsistent sensitivities when used on awake clinic patients. We believe the painful valgus force applied during traditional pivot shift techniques is the primary culprit and can be circumvented with our novel examination technique. Indications: The reason for publishing this examination technique is to maximize the sensitivity and accuracy of the pivot shift examination in the awake patient. Technique Description: Four major modifications of Ronald Losee’s original valgus-based examination technique are introduced. These are the 4 general modifications: minimizing the sagittal plane arc of motion, avoiding applying valgus force to the knee, application of gentle anteriorly directed force to the lateral tibia, and performing the examination on the patient’s noninjured knee first. We also provide detailed description of the hand placement during the Albright-Losee pivot shift test. (1) Once the patient is relaxed, the examiner’s hands are placed as follows: (1) the ulnar side of the examiner’s thumb is applied to the posterior aspect of the fibular head. The fingers are placed above the patella on the distal femur as shown in the video. (2) With the examiner’s hands in the correct position, the knee is flexed to 20° to 30°. One-to-3 pounds of anterior translatory force is then applied by the side of the thumb to the fibular head while the knee is taken slowly toward extension. Pathological anterior tibial translation can be expected to begin in a 20° to 30° range short of the patient’s complete knee extension. The examiner must be conscious not to provide any valgus or additional internal or external rotation of the leg. Results: This examination is useful for reproducing the subluxation phenomenon in anterior cruciate ligament (ACL)-deficient knees. Our work has shown that these modifications yield an accuracy of 95.51% and a sensitivity of 94.7% in 353 knees examined by 71 clinicians. Discussion/Conclusion: The Albright-Losee pivot shift test is an easy to perform, highly sensitive, and highly specific test. In our recently submitted American Journal of Sports Medicine manuscript, the Albright-Losee pivot shift test suggested to be of greater value than Lachman test. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Correlation among Knee Muscle Strength and Self-Reported Outcomes Score, Anterior Tibial Displacement, and Time Post-Injury in Non-Coper Anterior Cruciate Ligament Deficient Patients: A Cross-Sectional Study.

Little attention has been paid to knee muscle strength after ACL rupture and its effect on prognostic outcomes and treatment decisions. We studied hamstrings (H) and quadriceps (Q) strength correlation with a patient-reported outcome measures score (International Knee Documentation Committee, IKDC), anterior tibial translation (ATT), and time post-injury in 194 anterior cruciate ligament deficient patients (ACLD) who required surgery after a failed rehabilitation program (non-copers). The correlation between knee muscle strength and ATT was also studied in 53 non-injured controls. ACLD patients showed decreased knee muscle strength of both the injured and non-injured limbs. The median (interquartile range) values of the H/Q ratio were 0.61 (0.52–0.81) for patients’ injured side and 0.65 (0.57–0.8) for the non-injured side (p = 0.010). The median H/Q ratio for the controls was 0.52 (0.45–0.66) on both knees (p < 0.001, compared with the non-injured side of patients). The H/Q, ATT, and time post-injury were not significantly correlated with the IKDC score. ATT was significantly correlated with the H/Q of the injured and non-injured knees of patients, but not in the knees of the controls. Quadriceps strength and H/Q ratio were significantly correlated with ATT for both limbs of the patients. IKDC score correlated significantly with the quadriceps and hamstrings strengths of the injured limb but not with the H/Q ratio, ATT or time passed after injury.

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 (I 2 > 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.

Clinically Reliable Knee Flexion Angle Measured on Stress Radiography for Quantifying Posterior Instability in Posterior Cruciate Ligament Injury.

Background:After posterior cruciate ligament injury, stress radiography is a common method of quantifying posterior instability, defined as the side-to-side difference in posterior tibial displacement (PTD) between the injured knee and contralateral noninjured knee. However, no study has evaluated the reliability of PTD according to knee flexion angle (KFA) measurements on stress radiographs.Purpose:To evaluate the test-retest reliability of stress radiographic measurements of the KFA in the noninjured knee. In addition, we established a reliable range of KFAs to indicate posterior instability by comparing results with the instability measured at 90° KFA, which is considered the gold standard.Study Design:Cohort study (diagnosis); Level of evidence, 3.Methods:We evaluated patients who had undergone bilateral stress radiographic examinations at least 5 times for ligament injuries between January 2013 and November 2019. All examinations were performed on a Telos device with a 150-N posterior load. A total of 120 knees and 644 stress radiographs were enrolled. We measured the KFA and PTD on stress radiographs and evaluated the reliability of repeated PTD measurement and the correlation between KFA and PTD.Results:The distribution of the actual noninjured knee KFA ranged from 56.9° to 106.7°. Among the 644 radiographs, 155 (24.1%) showed KFAs between 85° and 95°, and 287 (44.6%) showed KFAs between 80° and 85°. A significant correlation was found between KFA and PTD (P < .001), and the intrapatient intraclass correlation coefficient (ICC) was 0.788. A KFA range of 85° to 92° satisfied the criteria of high ICC (0.885) and nonsignificant correlation between KFA and PTD (P = .055) and thus was considered a reliable range of KFAs for quantifying posterior instability. We found no significant risk factors for measurement error, including age (P = .674), sex (P = .328), height (P = .957), weight (P = .248), or body mass index (P = .257).Conclusion:We found high reproducibility of posterior displacement measurements on Telos stress radiography at a KFA of 85° to 92° in noninjured knees.

Development of supine and standing knee joint position sense tests

ObjectivesWe aimed to assess the test-retest reliability of a supine and standing knee joint position sense (JPS) test, respectively, and whether they discriminate knees with anterior cruciate ligament (ACL) injury from asymptomatic knees. DesignRepeated measures and cross-sectional. SettingResearch laboratory. ParticipantsFor test-retest reliability, 24 persons with asymptomatic knees. For discriminative analysis: 1) ACLR - 18 persons on average 23 months after unilateral ACL reconstruction, 2) CTRL - 23 less-active persons, and 3) ATHL - 21 activity level-matched athletes. Main outcome measuresAbsolute error (AE) and variable error (VE). ResultsTest-retest reliability was generally highest for AE of the standing test (ICC 0.64–0.91). Errors were less for the standing compared to the supine test across groups. CTRL had greater knee JPS AE (P = 0.005) and VE (P = 0.040) than ACLR. ACLR knees showed greater VE compared to the contralateral non-injured knees for both tests (P = 0.032), albeit with a small effect size (ηp2 = 0.244). Conclusions: Our standing test was more reliable and elicited lesser errors than our supine test. Less-active controls, rather than ACLR, produced significantly greater errors. Activity level may be a more predominant factor than ACLR for knee JPS ∼2 years post-reconstruction.

Anterior cruciate ligament bundle insertions vary between ACL-rupture and non-injured knees.

The present study aimed to investigate the three-dimensional topographic anatomy of the anterior cruciate ligament (ACL) bundle attachment in both ACL-rupture and ACL-intact patients who suffered a noncontact knee injury and identify potential differences. Magnetic resonance images of 90 ACL-rupture knees and 90 matched ACL-intact knees, who suffered a noncontact knee injury, were used to create 3D ACL insertion models. In the ACL-rupture knees, the femoral origin of the anteromedial (AM) bundle was 24.5 ± 9.0% posterior and 45.5 ± 10.5% proximal to the flexion-extension axis (FEA), whereas the posterolateral (PL) bundle origin was 35.5 ± 12.5% posterior and 22.4 ± 10.3% distal to the FEA. In ACL-rupture knees, the tibial insertion of the AM-bundle was 34.3 ± 4.6% of the tibial plateau depth and 50.7 ± 3.5% of the tibial plateau width, whereas the PL-bundle insertion was 47.5 ± 4.1% of the tibial plateau depth and 56.9 ± 3.4% of the tibial plateau width. In ACL-intact knees, the origin of the AM-bundle was 17.5 ± 9.1% posterior (p < 0.01) and 42.3 ± 10.5% proximal (n.s.) to the FEA, whereas the PL-bundle origin was 32.1 ± 11.1% posterior (n.s.) and 16.3 ± 9.4% distal (p < 0.01) to the FEA. In ACL-intact knees, the insertion of the AM-bundle was 34.4 ± 6.6% of the tibial plateau depth (n.s.) and 48.1 ± 4.6% of the tibial plateau width (n.s.), whereas the PL-bundle insertion was 42.7 ± 5.4% of the tibial plateau depth (p < 0.01) and 57.1 ± 4.8% of the tibial plateau width (n.s.). The current study revealed variations in the three-dimensional topographic anatomy of the native ACL between ACL-rupture and ACL-intact knees, which might help surgeons who perform anatomical double-bundle reconstruction surgery. III.

Quantitative Evaluation of Dynamic Lateral Meniscal Extrusion After Radial Tear Repair

Background:Radial tears of the lateral meniscus frequently accompany acute anterior cruciate ligament (ACL) injuries and lead to increased joint stress and pathological meniscal extrusion (ME). The dynamic behavior of the lateral meniscus after radial tear repair with respect to ME has not been described.Purpose:To quantitatively assess dynamic lateral ME after all-inside radial tear repair.Study Design:Case series; Level of evidence, 4.Methods:Patients who underwent ACL reconstruction and all-inside radial tear repair of the lateral meniscus and had no history of contralateral knee injuries were included. Magnetic resonance imaging scans were acquired in loaded (50% of body weight) and unloaded conditions of both the injured and noninjured knees. A custom-made pneumatically driven knee brace was used for standardized knee positioning in 10° of flexion and with axial load application. Quantitative measures included the absolute lateral ME, meniscal body extrusion ratio, and Δ extrusion. Preoperative and postoperative unloaded extrusion data were compared by paired t tests. For postoperative data, the concomitant influence of the factors “leg” and “condition” were assessed through factorial analyses of variance.Results:A total of 10 patients with a mean follow-up of 47.9 months were enrolled. The intraclass correlation coefficient (ICC) confirmed good interrater reliability (ICC, 0.898) and excellent intrarater reliability (ICC, 0.976). In the unloaded injured leg, all-inside repair reduced ME from 3.15 ± 1.07 mm to 2.13 ± 0.61 mm (–32.4%; P = .033). Overall, load application led to a significant increase in ME (+0.34 mm [+21.8%]; P = .029). Significantly greater ME was observed in the injured knee (+1.10 mm [+93.2%]; P = .001) than in the noninjured knee. The condition × leg interaction was not significant (P = .795), suggesting that the compression-associated increase in ME did not differ significantly between the injured and noninjured knees.Conclusion:Lateral ME depends on the knee status and loading condition. All-inside repair of radial meniscal tears led to a reduction of extrusion with no alteration in dynamic lateral ME. Meniscus-preserving therapy is recommended in the case of a radial lateral meniscal tear to preserve its dynamic behavior.

Osteoarthritis and ACL Reconstruction-Myths and Risks.

Anterior cruciate ligament (ACL) injury is one of the most common ligamentous injuries suffered by athletes participating in cutting sports. A common misperception is that ACL reconstruction can prevent osteoarthritis (OA). The goal of this paper is to review and discuss the contributing factors for the development of OA following ACL injury. There has been interesting new research related to ACL reconstruction. As understanding of knee biomechanics following ACL injury and reconstruction has changed over time, many surgeons have changed their surgical techniques to low anterior drilling to position their femoral tunnel in an attempt to place the ACL in a more anatomic position. Even with this change in the femoral tunnel position, 85% of knees following ACL reconstruction have abnormal tibial motion compared to contralateral non-injured knees. Studies have shown increases in inflammatory cytokines in the knee following ACL injury, and newer MRI sequences have allowed for earlier objective detection of degenerative changes to cartilage following injury. Recent studies have shown that injecting IL-1 receptor antagonist and corticosteroids can modulate the post-injury inflammatory cascade. ACL reconstruction does not prevent the development of OA but can improve knee kinematics and reduce secondary injury to the cartilage and meniscus. Advancements in imaging studies has allowed for earlier detection of degenerative changes in the knee, which has allowed researchers to study how new interventions can alter the course of degenerative change in the knee following ACL injury.

Minimally invasive treatment of tibial plateau depression fractures using balloon tibioplasty: Clinical outcome and absorption of bioabsorbable calcium phosphate cement.

The exact reconstruction of the tibial plateau and articular surface is the main operative aim in the treatment of tibial plateau depression fractures. For selected cases, a novel technique with the use of balloon tibioplasty in combination of bioabsorbable calcium phosphate cement is available. In this study, the first objective was to answer the question whether the clinical outcome parameters after balloon tibioplasty are comparable to open reduction procedures described in the literature. Secondly, we asked whether the cement absorption is safe in relation to adverse effects like osteolysis and measured the absorption ability during the bone conversion process in the proximal tibia bone. Eight patients (mean age 54 years; 4 males and 4 females) received the abovementioned surgical procedure. Mean follow-up period was 27 months. This study evaluated clinical outcome and radiological measured cement absorption within the postoperative course. Cement absorption was measured on X-rays and calculated based on the greatest extend on anterior-posterior and lateral view radiographs just after the operation on the latest available follow-up. WOMAC score showed a mean of 93. Radiologic absorption was 1/5 at a mean of 18 months. No osteolysis reaction was seen surrounding the cement. This far, promising clinical and radiological results have been shown with WOMAC scores comparable to the results of noninjured knees. The indication for this relatively new technique is restricted to isolated depression fractures. It is a useful tool to facilitate the reduction of select depressed tibial fractures. The radiologic absorption effect seems to be quite fast in bone remodeling and safe without any osteolysis or osseous reaction.

Pain and outcome prediction in muscle strength rehabilitation after knee injury in recreational athletes.

Effects of rehabilitation on knee function, activity and health-related quality of life after soft-tissue knee injury have been widely studied in clinical trials, but there is still a lack of data on the relation between knee muscle strength and athlete's perceived performance to identify sports-risk modifiers. We performed a prospective observational clinical study of knee muscle strength and self-reported health during rehabilitation after unilateral knee soft-tissue injury in recreational sports. Forty-three patients performed isokinetic dynamometry and filled in the Short form Health Survey (SF-36) and the Oxford Knee Score questionnaires before and after 4 months of instructed home strengthening program. We observed significant improvement in peak torque deficit between two limbs during concentric extension (PTDE) and flexion, dynamic control ratio of the involved knee, most of the SF-36 subscales and the Oxford Knee Score values (P ≤ 0.001). Dynamic control ratio of the uninvolved knee values remained below referential values and unchanged. Improvement of PTDE correlated positively with improvement of the bodily pain subscale of SF-36 score (r = 0.51, P < 0.001). Receiver operating characteristic analysis indicated that reduction of pain by at least nine points predicts at least 10% reduction in PTDE, whereby the bodily pain change achieved poor (56%) sensitivity and good (86%) specificity as a rehabilitation success measure for recreational athletes after knee injury. Primary inferior eccentric strength of noninjured knee hamstrings might indicate increased risk of knee injury. Diminished perceived pain predicts strength improvement of the injured knee extensors with poor sensitivity and good specificity.

Motor imagery in high-functioning individuals with chronic anterior cruciate ligament deficiency: A cross-sectional study

BackgroundThere is increasing evidence that motor imagery performance (MIP) is impaired in conditions that have a component of movement dysfunction. However, MIP has not been investigated in people with chronic anterior cruciate ligament (ACL) deficiency who experience limited disability and function at high levels. HypothesisThis study had three objectives: (1) to assess implicit MIP in individuals with a chronic ACL deficient (ACLD) knee compared with healthy controls (i.e., intact anterior cruciate ligament); (2) to determine if the location of ACL deficiency affects MIP (dominant versus non-dominant leg); and (3) to determine if impairment in MIP is specific to the side (injured versus non-injured) of ACL deficiency. MethodsForty-five participants with chronic ACLD knee and 44 healthy controls completed a left/right judgement task of pictured knees using the “Recognise” app to evaluate implicit MIP. Accuracy and reaction time of judgements were compared between groups. Additionally, within the chronic ACLD knee group, we made comparisons between the dominant ACLD knee and non-dominant ACLD knee subgroups and between the injured knee and the non-injured knee of the ACLD group. ResultsThere were no differences in implicit MIP between the ACLD knee and the control group, the non-injured knee versus injured knee of the ACLD knee group, or the dominant ACLD knee versus non-dominant ACLD knee subgroups. ConclusionImplicit MIP is not disrupted in high functioning individuals with chronic ACLD knee.

Analysis of Motor Coordination Alteration after Anterior Cruciate Ligament Reconstruction

Research background and hypothesis. The Anterior cruciate ligament (ACL) is the most commonly injured ligament of the knee and its injuries result in significant functional impairment. Injury to the ACL is associated with altered knee joint loading and impaired neuromuscular control, which defined as the ability to produce well controlled movements and dynamic balance.Research aim. The aim of this study was to evaluate motor coordination and functional capacity of patients who received rehabilitation program following ACL reconstruction.Research methods. The study included 15 males aged 33.7 ± 2.49 years who had undergone unilateral ACL reconstruction with a semitendinosus/gracilis (STG) graft in Kaunas Clinical hospital. For objective functional testing, we used figure-of-eight movement coordination test. The Lysholm questionnaire was included as a disability outcome measure following ACL injury and reconstruction. The patients were assessed preoperatively and after 5 and 21weeks postoperatively.Research results. The results of this study indicated that motor coordination timescale showed significant differences (p &lt; 0.05) between the injured and the healthy legs before surgery and after 5 and 21 weeks. The movement coordination test data showed that there the timescale significantly longer on the injured knee compared with the noninjured knee. After 21 weeks of rehabilitation we found significantly lower (p &lt; 0.05) values in injured knees compared with the preoperative data. In injured knee the timescale after 21 weeks of rehabilitation was significantly (p &lt; 0.05) longer compared with noninjured knee.The Lysholm questionnaire scale indicated that there was a significant difference in the results for values (p &lt; 0.05) before surgery and after 21 weeks of rehabilitation. The questionnaire scale data showed that after 21 weeks of rehabilitation results for values was significantly (p &lt; 0.05) highest compared with before surgery and after 5 weeks.Discussion and conclusions. There was improvement in the injured leg in mean motor coordination timescale 21 weeks after ACL reconstruction, but the timescale was higher than in the uninjured leg. After 21 weeks of ACL reconstruction knee functional status in most patients was good or excellent.Keywords: knee joint, the Lysholm questionnaire, movement coordination test.

Knee kinematics in anatomic anterior cruciate ligament reconstruction with four- and five-strand hamstring tendon autografts

An alternative to the gold standard fourstrand hamstring tendon autograft for anterior cruciate ligament (ACL) reconstruction is the five-strand graft. The rationale for its use is to increase graft width to better restore the anatomical footprint and biomechanical properties of the native ACL when unable to create a four-strand graft of 8 mm in diameter. To date, there are no trials assessing the use of this wider graft and its effect on the kinematics of the knee. The aim of this study was to determine whether the use of a wider five-strand hamstring tendon autograft in ACL reconstructive surgery better replicated the kinematics of a normal non-injured knee than the gold standard four-strand graft. Forty-four patients (27 operative and 17 normal control) were recruited for this study over a 12-month period. Twenty patients underwent anterior cruciate ligament reconstruction with the four-strand hamstring tendon autograft construct and seven with the five-strand construct. All patients underwent kinematic testing using the KneeKG System (EMOVI, CA) according to a strict testing protocol. The operative group underwent testing at six (T1) and twelve (T2) weeks postoperatively. Analysis of variance was used to compare six degrees of freedom kinematic data across groups and correlations were made between kinematic data and intraoperatively measured graft width. Postoperative kinematic data revealed no statistically significant differences between graft types. At 12 weeks significant differences were seen between the four-strand and control group in the flexion/extension cycle in the preloading phase and at terminal stance. Significant correlations were seen between graft width and rotational stability at Preloading (Pearson’s r=0.415) and Maximum Internal Rotation (Femoral Width Pearson’s r=0.456 and Tibial Width Pearson’s r=0.476) at 12 weeks regardless of graft type.This study demonstrated that to achieve anatomic knee kinematics in primary ACL reconstruction in the first 12 weeks postoperatively, a technique to optimise autograft width using a five-strand hamstring tendon autograft is useful. A relationship was found between graft width and more stable rotational kinematics of the knee during walking, regardless of graft type.

Longitudinal analysis of tibiofemoral cartilage contact area and position in ACL reconstructed patients

Patients who have suffered ACL injury are more likely to develop early onset post-traumatic osteoarthritis despite reconstruction. The purpose of our study was to evaluate the longitudinal changes in the tibiofemoral cartilage contact area size and location after ACL injury and reconstruction. Thirty-one patients with isolated unilateral ACL injury were followed with T2 weighted Fast Spin Echo, T1ρ and T2 MRI at baseline prior to reconstruction, and 6 months, 1 year, and 2 years after surgery. Areas were delineated in FSE images with an in-house Matlab program using a spline-based semi-automated segmentation algorithm. Tibiofemoral contact area and centroid position along the anterior-posterior axis were calculated along with T1ρ and T2 relaxation times on both the injured and non-injured knees. At baseline, the injured knees had significantly smaller and more posteriorly positioned contact areas on the medial tibial surface compared to corresponding healthy knees. These differences persisted 6 months after reconstruction. Moreover, subjects with more anterior medial centroid positions at 6 months had elevated T1ρ and T2 measures in the posterior medial tibial plateau at 1 year. Changes in contact area and centroid position after ACL injury and reconstruction may characterize some of the mechanical factors contributing to post-traumatic osteoarthritis. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2718-2727, 2018.