Knee Joint Stability Research Articles

Effects of the tibial tunnel position on knee joint stability and meniscal contact pressure after double-bundle anterior cruciate ligament reconstruction

BackgroundTo investigate the effect of the tibial tunnel position on knee stability and the maximum contact area and peak contact pressure on the menisci after double-bundle anterior cruciate ligament (ACL) reconstruction. MethodsTen human knee specimens (mean age: 74.1 ± 15.8 years) were used in this study. The anterior tibial loading test was conducted using a material testing machine at 30°, 60°, and 90° of knee flexion, with the anterior tibial translation (ATT) and the maximum contact area and peak contact pressure on the menisci measured. Outcome measures were compared between the following groups: 1) intact ACL (intact group); 2) anatomical tibial tunnel position (anatomical group) and 3) posterior tibial tunnel position (posterior group) with double-bundle reconstruction, and 4) ACL-deficient (deficient group). ResultsIn response to a 100 N anterior tibial load, the ATT was greater for the posterior and ACL-deficient groups compared to that in the intact group. The normalized maximum contact area of the medial meniscus significantly decreased for the posterior group compared to that in the intact group. The normalized peak contact pressure on the medial meniscus increased in all groups compared to that in the intact group, but with no between-group differences in pressure applied to the lateral meniscus. ConclusionsATT and contact pressure on the medial meniscus increased, concomitant with a decrease in contact area of the medial meniscus, as the position of the tibial tunnel position moved towards a posterior position.

A clinical comparative study on the reconstruction of posterior cruciate ligament with single tendon autograft plus high-strength braid or not

Objective To observe the difference of the clinical effect of using high-strength woven suture or not in the reconstruction of posterior cruciate ligament (PCL) with single tendon autograft under arthroscope. Methods The clinical data of 40 patients with posterior cruciate ligament rupture and ligament reconstruction admitted to Shengjing Hospital Affiliated to China Medical University from 2017 to 2018 were analyzed retrospectively.According to whether or not to add Arthrex ar-7200 (Arthrex, Naples, FL, USA) braided suture in the autogenous hamstring graft, the patients were divided into test group (17 cases) and control group (23 cases). The posterior drawer test (PDT) was used as the knee joint stability test to evaluate the knee function, IKDC score, Lysholm score and Tegner score were used as the evaluation criteria.The evaluation results of the knee joint in the experimental group and the control group were compared before and one year after the operation, and the evaluation results of the knee joint in the two groups were compared one year after the operation and one year before the operation Results Functional aspects of knee joint: The Lysholm score of the experimental group was expressed by median (quartile) 1 year before and after operation.Lysholm scores of the trail group were 64 (40, 81) and 84 (73, 87) preoperative and postoperative, respectively, the control group were 68 (48, 78) and 80 (70, 90) respectively, there was statistically difference before and after surgery (Z value was -2.535 and -3.576, P value was 0.011 and 0.05). The Tegner score of the experimental group before and 1 year after operation was expressed as the median [quartile], which was 2.0 (1.0, 2.5), 6.0 (5.0, 7.5) respectively, and that of the control group was 2.0 (1.0, 3.0), 6.0 (4.0, 7.0) respectively.There was statistically significant difference between the two groups before and after operation (Z value was -3.397, -4.122, all P 0.05). One year after operation, the IKDC scores of the two groups were significantly improved (Z values were -3.750, -4.234, all P 0.05). There was no significant difference between the two groups in the postoperative drawer test (P>0.05); one year after the operation, the stability of the two groups was significantly improved (Z values were -3.674, -4.083, all P<0.01), and the stability of the experimental group was significantly better than that of the control group(Z=0.156, P=0.039). Conclusion Posterior cruciate ligament reconstruction with autologous hamstring muscle can achieve satisfactory clinical results, and placing high-strength braided sutures in the graft is more conducive to the recovery of knee joint stability. Key words: Posterior cruciate ligament; Ligament reconstruction; Arthroscopy; Autogenous hamstring tendon

Relationship between Knee Muscle Strength and Fat/Muscle Mass in Elderly Women with Knee Osteoarthritis Based on Dual-Energy X-Ray Absorptiometry.

Purpose: This study aimed to examine the characteristics and correlation of knee muscle strength and body composition (fat and muscle mass) among elderly women aged 60–70 years with knee osteoarthritis. The present study hypothesized that the muscle mass and the peak torques of the knee joints were considerably low in the knee osteoarthritis (KOA) group. Methods: A total of 47 elderly women aged 60–70 years were recruited from Yangpu District in Shanghai and assigned to the knee osteoarthritis (n = 25, KOA) or healthy control group (n = 22, CON). The knee extension/flexion isokinetic strength measurements were conducted on an isokinetic dynamometer at angular velocities of 90°/s. Dual-energy X-ray absorptiometry was used to measure the body composition (fat and muscle mass in the whole body and lower limbs). The independent sample t-test was employed to determine the effects of knee osteoarthritis on each variable, and the Pearson correlation analysis was used to investigate the correlation between the body composition and knee muscle strength. Results: Compared with the CON, the KOA exhibited the following: (1) Lower absolute peak knee extension torque (66.02 ± 10.57 vs. 56.61 ± 14.69 Nm), relative peak knee extension (1.11 ± 0.19 vs. 0.89 ± 0.26 Nm/kg), and flexion torque (0.62 ± 0.15 vs. 0.54 ± 0.16 Nm/kg, p < 0.05); (2) greater relative peak torque ratio of the knee extension and flexion (0.55 ± 0.08 vs. 0.62 ± 0.15, p < 0.05); and (3) lower total body muscle mass percentage (63.24% ± 4.50% vs. 59.36% ± 3.94%), particularly in the lower limbs (19.96% ± 1.51% vs. 18.47% ± 1.49%, p < 0.05). Furthermore, the total body fat mass percentage was negatively associated with the relative peak knee extension and flexion torque regardless of the group (p < 0.05). The total body muscle mass percentage was positively associated with the relative peak knee extension torque in the two groups and the relative peak knee flexion torque in the CON (p < 0.05). Conclusion: For elderly women with knee osteoarthritis, knee muscle strength decreases significantly, especially for the extensor strength. Moreover, compared with fat mass, the index of muscle mass is more sensitive in detecting the decrease in knee joint torque. Therefore, rather than weight loss alone, the quadriceps muscle and the rear-thigh muscles, which maintain the stability of knee joints during rehabilitation training, should be strengthened emphatically to improve muscle mass.

Is Cyclic Exercise Performed before Tibial Fixation Effective on Grafts during Anterior Cruciate Ligament Reconstruction?

Objectives:The necessity of cyclic exercise to pre-stretch the autograft before tibial fixation during ACL reconstruction is unknown. In this study, we evaluated whether there was a statistically significant difference between the results of patients who underwent cyclic exercise by way of physical examinations, knee joint stability tests, and functional evaluation tests, compared with the patients who underwent ACL reconstructions with or without cyclic exercise.Methods:Between March 2016 and May 2018, 59 patients with at least eight months’ follow-up of an ACL reconstruction were identified. Thirty patients (Group 1) who underwent cyclic exercise before tibial fixation and 29 patients (Group 2) who did not undergo cyclic exercise were evaluated and compared.Results:The mean age of the patients in Group 1 and Group 2 was 25.9 (range, 18-36) years and 25.2 (range, 18-35) years, respectively. The mean follow-up period in Group 1 was 14.6 (range, 8-22) months and 13.5 months in Group 2 (range, 8-21 months).The mean Lysholm scores of Group 1 and 2 were 95.1 (range, 83-100) and 87.1 (range, 78-100), respectively. The modified Cincinnati scores of Groups 1 and 2 were 28.7 (range, 24-30) and 26.2 (range, 21-30). The mean IKDC subjective knee evaluation scores in Groups 1 and 2 were 91.9 (range, 83-100) and 86.7 (range, 75-100). The mean thigh atrophy was 1.5 cm in Group 1 and 2.5 cm in Group 2. In Group 1, 23 patients jumped 85% of the distance compared with the intact side in the single-legged hop test, and 12 patients in Group 2 were able to hop this distance successfully.Group 1 had statistically significantly better results in Lysholm activity scores, modified Cincinnati scores, IKDC subjective knee assessment scores, two-time IKDC activity scale results, comparison of thigh diameters, and single-legged hop tests (p<0.05). No significant difference was found in other examinations and tests.Conclusion:Cyclic exercise during the operation had a positive effect on functional scores. We believe that cyclic exercise should be added to the operative procedure.

Knee joint kinematics of the pendulum test in children with and without Down syndrome

BackgroundThe Wartenberg pendulum test is a common clinical test that is used to measure stiffness about the knee in persons with and without disabilities such as cerebral palsy and Down syndrome (DS). Adults and adolescents with DS show fewer number of swing cycles and a lower relaxation index than healthy controls. However, it is not clear if children with DS show a similar trend compared to typically developing (TD) children. Research questionWas the knee joint kinematics different between children with and without DS during the pendulum test? MethodsThirteen children with DS and 13 TD children participated in this study. There were two load conditions: no load (NL) and with ankle load (AL) equal to 2 % of the subject’s body weight. Five trials of a pendulum test were collected for each condition. ResultsThe DS group showed a smaller first flexion excursion, a lower relaxation index, lower mean and peak velocities and accelerations during the first and second flexion and extension, and greater variability of acceleration during the first flexion than the TD group across both load conditions. This suggests that the DS group may have greater stiffness of the knee than the TD group to compensate for joint instability. SignificanceThe pendulum test appears to be a valid test to evaluate the passive stiffness of the knee in children with DS. The lower relaxation index in children with DS suggests that larger bursts of quadriceps may be activated during a pendulum test, particularly in the first flexion excursion, to assure the knee joint stability.

The anterolateral ligament is a secondary stabilizer in the knee joint: A validated computational model of the biomechanical effects of a deficient anterior cruciate ligament and anterolateral ligament on knee joint kinematics.

ObjectivesThe aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models.MethodsFive subject-specific musculoskeletal models were validated with computationally predicted muscle activation, electromyography data, and previous experimental data to analyze effects of the ALL and ACL on knee kinematics under gait and squat loading conditions.ResultsAnterior translation (AT) significantly increased with deficiency of the ACL, ALL, or both structures under gait cycle loading. Internal rotation (IR) significantly increased with deficiency of both the ACL and ALL under gait and squat loading conditions. However, the deficiency of ALL was not significant in the increase of AT, but it was significant in the increase of IR under the squat loading condition.ConclusionThe results of this study confirm that the ALL is an important lateral knee structure for knee joint stability. The ALL is a secondary stabilizer relative to the ACL under simulated gait and squat loading conditions.Cite this article: Bone Joint Res 2019;8:509–517.

Sensitivity of the knee joint response, muscle forces and stability to variations in gait kinematics-kinetics

Sensitivity analysis of the knee joint response to variations in gait kinematics-kinetics as reported in the literature is crucial for improved understanding and more effective prevention-treatment strategies. Using our validated finite element-musculoskeletal (FE-MS) model of lower extremity, we investigate the sensitivity of knee anterior cruciate ligament (ACL), muscle, and contact forces plus stability to the reported scatter in asymptomatic gait data. Three highly loaded stance instants (25, 50 and 75%) with five levels (mean, ±0.5SD and ±SD) for each of six knee joint angles-moments are used employing Taguchi approach (25 experiments) and regression equations. ACL force drops significantly at larger flexion angles (all periods) and smaller internal moment (at 75% only) but increases with the flexion moment. Tibiofemoral (TF) medial-lateral contact force partitioning is found, contrary to the common claim, most sensitive to changes in the adduction angle and not in the adduction moment. Total TF contact force increases significantly at greater moments (but not angles), especially in the sagittal plane. Forces in lateral hamstrings are significantly influenced by changes in adduction angles-moments. Larger flexion moments (at 25 and 50%) significantly increase forces in quadriceps and on patellofemoral (PF) contact. Sagittal moment, adduction moment (at 75%) and flexion angle (at 25%) contribute most to the joint stability. A strong inverse correlation exists between the joint stability and the total TF compression force. These findings can be exploited to adapt and modify intact, injured and reconstructed knee joint responses during gait.

The Anterolateral Structure of the Knee Does Not Affect Anterior and Dynamic Rotatory Stability in Anterior Cruciate Ligament Injury: Quantitative Evaluation With the Electromagnetic Measurement System

Background: The biomechanical function of the anterolateral structure (ALS), which includes the anterolateral joint capsule and anterolateral ligament (ALL), remains a topic of debate. Hypothesis: The ALS contributes to knee joint stability during the Lachman test and the pivot-shift test in anterior cruciate ligament (ACL)–deficient knees. Study Design: Controlled laboratory study. Methods: Fourteen fresh-frozen hemipelvis lower limbs were used. For 7 specimens, the anterior one-third of the ALS and the residual ALS were cut intra-articularly with a radiofrequency device. Subsequently, the ACL was cut arthroscopically. For the other 7 specimens, the ACL was cut first, followed by the anterior one-third of the ALS and the residual ALS intra-articularly. During the procedures, the iliotibial band (ITB) was kept intact. At each condition, the anterior tibial translation (ATT) during the manual Lachman test and the acceleration of posterior tibial translation (APT) and the posterior tibial translation (PTT) during the manual pivot-shift test were measured quantitatively with an electromagnetic measurement system. The mean values of those parameters were compared among 6 groups (ACL intact, one-third ALS cut, all ALS cut, ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut). Results: The mean ATTs during the Lachman test and the mean APTs and PTTs in the ACL-cut conditions (ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut) were significantly larger than those under the ACL-intact conditions (ACL intact, one-third ALS cut, all ALS cut) (P < .01). However, no statistically significant differences were observed among the intact, one-third ALS–cut, and all ALS–cut conditions, within the ACL-intact or ACL-cut conditions. Conclusion: Intra-articular dissection of the ALS did not increase the ATT during the Lachman test or the APT and PTT during the pivot-shift test under the intact condition of the ITB, regardless of the integrity of the ACL. When the ITB is intact, the ALS does not have a significant role in either anterior or dynamic rotatory knee stability, while the ACL does. Clinical Relevance: Recent growing interest about ALL reconstruction or ALS augmentation may not have a large role in controlling either anterior or dynamic rotatory knee instability in isolated ACL-deficient knees.

Surgical Treatment of Chronic Rupture of the Quadriceps Using a Modified Pulvertaft Weave Technique

The extensor mechanism provides active knee joint extension and stability of the patellofemoral joint. Rupture of the quadriceps tendon, although uncommon, is therefore associated with impairment in knee joint stability and, thus, requires surgical repair. Although various techniques provide excellent clinical outcomes for acute rupture, treatment of chronic rupture remains clinically challenging. We describe our modified technique for quadriceps tendon repair using a semitendinosus tendon autograft, with suturing of the quadriceps tendon stump to the patella via transosseous sutures, wherein the use of allograft and anchors is avoided. Our modified Pulvertaft weave technique is simple and reproducible.

A new method for diagnosing biochemical abnormalities of anterior cruciate ligament (ACL) in human knees: A Raman spectroscopic study

Anterior cruciate ligament (ACL) plays an essential role in knee joint stability and kinematics. The microstructural irregularities such as cellular changes and disorganization of the extracellular matrix (ECM) alter the mechanical properties of the ligament, leading to a significant knee functional instability and progression of osteoarthritis (OA). So far, the identification of the local abnormality in ACL has routinely relied on invasive analytical techniques such as histology or biochemical assays. The non-invasive diagnosis using magnetic resonance imaging (MRI) is still limited to identifying the presence/absence of partial/complete ruptures and mucoid degeneration. In this study, laser micro-Raman spectroscopy with near-infrared excitation (785 nm) was applied to human ACL in order to establish optical algorithms for non-destructively diagnosing a degeneration state at molecular level.Raman spectra were obtained from 44 ex-vivo ACL specimens, and these were subsequently classified as an early (subclinical) and advanced (clinical) level of tissue degradation based on the histopathological scoring system. The significant differences in Raman peak intensities were found between the different degeneration groups, which were assigned to the vibrational modes of nucleic acids in cells, collagens, and phospholipids. Linear discriminant analysis (LDA) was performed to identify cut-off values for the distributions of Raman intensity and intensity ratios, which enable to best discriminate between the early and advanced degenerated tissues. Raman intensity algorithms derived from I1101/I1749, [I1002/I1516vs. I1101/I1749], and [I1002/I1749vs. I1101/I1749], yielded a maximum diagnostic sensitivity of 100%, specificity of 80%, and accuracy of 91% for discriminating the degeneration severity. Statement of SignificanceIn this study, laser micro-Raman spectroscopy was applied to human anterior cruciate ligament (ACL) to establish optical algorithms for non-destructively diagnosing the tissue degeneration at molecular level. To our knowledge, this is the first report on Raman diagnosis for human ACL. Linear discriminant analysis (LDA) was performed to identify cut-off values for Raman intensity and intensity ratios, which enable to best discriminate between an early (subclinical) and advanced (clinical) level of ACL degeneration. The intensity ratios of I1101/I1749, [I1002/I1516vs. I1101/I1749], and [I1002/I1749vs. I1101/I1749] yielded a maximum diagnostic sensitivity of 100%, specificity of 80%, and accuracy of 91% for discriminating the ACL degeneration. The present findings might contribute to expanding clinical diagnostic possibilities for non-invasively identifying tissue degeneration.

Evaluating the Accuracy of Tibial Tunnel Placement After Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Background: Anatomic anterior cruciate ligament (ACL) reconstruction improves knee kinematics and joint stability in symptomatic patients who have ACL deficiency. Despite a concerted effort to place the graft within the ACL’s native attachment sites, the accuracy of tunnel placement using contemporary techniques is not well established. Purpose: To use 3-dimensional magnetic resonance imaging (3D MRI) to prospectively evaluate the accuracy of tibial tunnel placement after anatomic ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Forty patients with symptomatic, ACL-deficient knees were prospectively enrolled in the study and underwent 3D MRI of both their injured and uninjured knees before and after surgery through use of a validated imaging protocol. The root ligament of the anterior horn of the lateral meniscus was used as a radiographic reference, and the center of the reconstructed graft was compared with that of the contralateral normal knee. The tunnel angles and intra-articular graft angles were also measured, as was the percentage overlap between the native tibial footprint and tibial tunnel. Results: The reconstructed tibial footprint was placed at a mean ± SD of 2.14 ± 2.45 mm (P < .001) medial and 5.11 ± 3.57 mm (P < .001) posterior to the native ACL footprint. The mean distance between the center of the native and reconstructed ACL at the tibial attachment site was 6.24 mm. Of the 40 patients, 18 patients had a tibial tunnel that overlapped more than 50% of the native footprint, and 10 patients had maximal (100%) overlap. Further, 22 of the 40 patients had less than 50% overlap with the native footprint, and in 12 patients the footprint was missing completely. Conclusion: Despite the use of contemporary surgical techniques to perform anatomic ACL reconstruction, a significant positioning error in tibial tunnel placement remains.

Functional knee stability in non-elite handball: balance and jump performance differ based on players' position.

Despite the great evolvement of sports medicine, there is still a lack of consensus among sports physicians regarding the decision of return to sports after knee injury, especially in non-elite sports. Currently, no sport-specific reference data for an objective reliable evaluation of functional knee stability exist. The purpose of this study was to assess objective measures on knee joint stability from an established test battery in non-elite handball. It was assumed that players' knee stability differs depending on their field position. One-hundred and sixty-five non-elite handball players with a mean age of 24.3 ± 5.5years underwent a test battery including two-legged and one-legged stability tests, two-legged and one-legged counter movement jumps, two-legged plyometric jumps, one-legged speedy jumps, and a quick feed test. Athletes' physical performance differs in terms of field position. Significant differences between handball players of different positions were found in regard to two-legged stability (p < 0.036) and one-legged stability in the dominant leg (p < 0.009). Players of different positions differed in ground contact time of the plyometric jumps (p < 0.017), whereas the other functional tests did not show significant differences. This study is first to report differences in functional knee stability of non-elite handball players on the basis of objective data. Significant differences of functional performance were noted, which were in congruence with position-specific demands. These findings demonstrate the importance of position-specific screening and training to prevent injuries. II.

An interventional study on functional outcome of combined anterior cruciate ligament and anterolateral ligament reconstruction

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The anterolateral ligament (ALL) is an important structure for rotational stability of knee joint after anterior cruciate ligament (ACL) rupture. Outcome of combined ACL and ALL reconstruction will change view of high demanding ACL tear cases.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A hospital based prospective interventional study was done in Department of Orthopaedics, SMS Medical College, Jaipur to find the functional outcome of combined anterior cruciate ligament and anterolateral ligament reconstruction. A total of 45 patients underwent ACL and ALL reconstruction. Indications for a combined procedure were associated grade 3 pivot shifts, high level of sporting activity and pivoting sports. Patients were assessed pre- and post-operatively with objective and subjective International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The mean follow up time was around 5 months. Two patients lost to follow up. Leaving 45 patients for final evaluation. At the last follow-up, all patients had full range of motion. The Lysholm, subjective IKDC, and objective IKDC scores were significantly improved (all p&amp;lt;0.0001). Pre-operatively, 38 patients had a grade 3 pivot shifts and 7 had a grade 2 according to the IKDC criteria. Post-operatively, 42 patients had a negative pivot shift (grade 0), and 3 patients were grade 1 (p&amp;lt;0.0001).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; This study demonstrates that a combined reconstruction can be an effective procedure without specific complications at a minimum follow-up of 6 months. Longer follow up is required to know any long term complications and functional outcome.&lt;/p&gt;

Efficacy of suprapatellar versus infrapatellar approach in tibial intramedullary nail fixation for tibial fracture: a systematic review and meta-analysis

Objective To investigate the efficacy of suprapatellar versus infrapatellar approach in tibial intramedullary nail fixation for tibial fracture. Methods Clinical trials that evaluated suprapatellar approach and infrapatellar approach for tibia intramedullary nailing fixation were searched in PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biology Medicine (CBM), Wanfang, Weipu and CNKI databases. Methodological qualities of the included studies were assessed using the Cochrane Collaboration tool and Newcastle-Ottawa Scale. Sensitivity analyses were performed to determine whether overall results were reliable. Publication bias was detected using Begg's test and Egger's test. Lysholm score, reoperation rate, Hospital for Special Surgery (HSS) score, operation time, intraoperative blood loss and hospital stay were selected to evaluate the clinical effect of suprapatellar approach and infrapatellar approach in tibial intramedullary nail fixation for tibial fracture. Results Two randomized controlled trials and six case-controlled studies involving 787 patients were included in the analysis. Sensitivity analyses indicated that the results were statistically significant. No significant publication bias was detected by Begg's test or Egger's test. Our meta-analysis indicated that suprapatellar approach had significantly higher Lysholm score (MD=1.04, 95%CI 0.82-1.26, P 0.05). Conclusion Compared with infrapatellar approach, suprapatellar approach in intramedullary nail fixation for tibial fracture can better relieve the pain, keep stability and motion of the knee joint and promote function recovery of knee joint. Key words: Tibial fractures; Fracture fixation, intramedullary; Suprapatellar approach

Knee isokinetic muscle strength and balance ratio in female soccer players of different age groups: a cross-sectional study

ABSTRACTBackground: As a consequence of years of soccer training and sexual maturation, there is an increase in lower body muscle mass and strength especially in the knee extensors and flexors muscles. In this context, the lack of knee joint stability, resulting from strength imbalance between knee extensor and flexors muscles, has been associated with knee injuries. The aim of this study was to compare the knee flexor and extensor muscle peak torque, average power, contralateral deficit, conventional and functional balance ratios of female soccer players from different age groups.Methods: Sixty-six female soccer players were divided into four groups: under 13 (U13), under 15 (U15), under 17 (U17) years old and professional (PRO). Flexor and extensor knee muscle strength in concentric and eccentric actions of both limbs were assessed using isokinetic dynamometer.Results: For the dominant limb, the knee concentric extensor muscles peak torques, assessed at 60 and at 240 deg/sec, and the average power of U15 group were significantly higher than U13 group. Extensor muscle average power of the PRO group was higher than U17. Dominant knee flexor average power of U15 was significantly higher than the U13 group. Peak torque at 60 deg/sec and 240 deg/sec and average power of the PRO group were higher than the U17 group. No differences were found regarding the eccentric action for flexor and extensor muscles. Conventional and functional balance ratios were similar among all age group, except for U13, which presented higher values than the U15 group for the dominant limb.Conclusions: The greatest improvement in muscular performance occur when the athlete starts practicing soccer (after U13) and when they become professional (after U17) and the balance ratios, and muscle balance ratios remain stable in all age groups, although they are below the recommended level in the literature, which may increase the risk for lower limb injury.

Knee stability after anterior cruciate ligament reconstruction with weight-bearing magnetic resonance imaging

Objective: To investigate the application value of the weight-bearing magnetic resonance imaging (MRI) in evaluating the stability of knee joint after anterior cruciate ligament reconstruction. Methods: From July 2011 to August 2013, a total of 25 patients with anterior cruciate ligament rupture and reconstruction surgery in the Second Affiliated Hospital of Soochow University were enrolled in this study, including 18 males and 7 females, with an average age of (32±5) years. All the patients underwent the weight-bearing MRI, knee joint passive relaxation test (Kneelax 3), and Lysholm score before the surgery and 3 and 6 months after the surgery. The three examinations before and after the operation were analyzed by repeated measures of general linear model, and paired t test was used to compare the results before and after the operation. The correlation between the three preoperative examinations was statistically analyzed. Results: The relaxation data measured by Kneelax 3 after the surgery was significantly lower than that before the operation [(1.1±0.9) mm vs (6.1±1.3) mm, t=16.9, P<0.01]. The post-operative lateral tibial plateau anterior shift score was less than the pre-operative score [(3.0±0.7) mm vs (4.8±1.2) mm, t=6.2, P<0.01]. The post-operative Lysholm score was significantly higher than that before the operation (89±6 vs 64±14, t=-8.3, P<0.05). There was a negative correlation between the anterior displacement of the lateral platform and Lysholm score (r=-0.902, P<0.01). There was no correlation between anterior displacement and passive relaxation of the lateral platform in preoperative weight-bearing MRI. Conclusions: Anterior cruciate ligament reconstruction can improve the knee stability. The stability of knee joint can be evaluated by weight-bearing MRI. The anterior tibial displacement measured by the weight-bearing MRI is correlated with the clinical score.

Early effectiveness of arthroscopic three-point suture technique in treatment of anterior cruciate ligament tibial eminence avulsion fracture

To investigate the early effectiveness of three-point suture technique in treatment of anterior cruciate ligament (ACL) tibial eminence avulsion fracture by arthroscopy. Between January 2016 and December 2017, 12 patients with ACL tibial eminence avulsion fractures underwent arthroscopic fixation of avulsion fractures with Ethibon suture using three-point suture technique. There were 9 males and 3 females, with an average of 36.4 years (range, 18-50 years). The fracture caused by traffic accident in 10 cases and sports in 2 cases. Among them, 1 patient was old fracture and 11 was fresh fracture. According to the modified Meyers-McKeever classification criteria, the fractures were rated as type Ⅲ in 7 cases and type Ⅳ in 5 cases. There were 2 cases of medial collateral ligament injury and medial meniscus injury. The preoperative International Knee Documentation Committee (IKDC) score was 37.9±4.7 and Lysholm score was 46.0±3.7. All operations completed smoothly. The operation time was 45-70 minutes (mean, 61.3 minutes). The incisions healed by first intention in all patients. The hospitalization stays ranged from 4 to 9 days (mean, 5 days). All patients were followed up 3-20 months (mean, 9.3 months). The anterior drawer test, Lachman test, and axis shift test in all patients were negative after operation. At last follow-up, the IKDC score was 89.7±2.5 and Lysholm score was 90.2±1.9, which were significantly higher than those before operation ( t=-30.94, P=0.00; t=-33.03, P=0.00). At last follow-up, the X-ray films showed 9 cases of fracture anatomical reduction and 3 cases of almost anatomical reduction, and 12 cases of fracture healing. For ACL tibial eminence avulsion fracture, arthroscopic three-point suture technique can effectively restore the stability of knee joint and obtain satisfactory early effectiveness.

Conversion of cemented revision total knee prostheses to arthrodesis using custom-made arthrodesis modules that preserve the cemented stem anchorage in patients with long-established extensor mechanism insufficiency: A case series

IntroductionLong-established extensor mechanism insufficiency that defies reconstruction is a rare, but devastating, complication after revision total knee arthroplasty (RTKA) that may require arthrodesis. For cemented stem guided knee prostheses with firmly attached stems, prosthesis explantation can lead to significant bone stock loss that may, at worst, make knee arthrodesis significantly more difficult or impossible to achieve. Under these circumstances, conversion of the cemented knee prosthesis with custom-made arthrodesis modules that preserve the existing stem anchorage may be a low-risk alternative. This case series presents this type of conversion to arthrodesis, which was performed for patients with a non-reconstructable, long-established extensor mechanism insufficiency. MethodsAfter intraoperatively ascertaining that reconstruction of the extensor mechanism insufficiency was impossible, the inlying revision prosthesis was converted into arthrodesis with custom-made arthrodesis modules, without explanting the cemented stems. ResultsConversion to arthrodesis was performed in four patients. There was no histopathological or microbiological evidence of a periprosthetic joint infection. Clinical follow-up showed a low level of pain, with a stable knee joint and proper implant position. The Oxford Knee Score increased from 20.5 (95% CI 17–26) to 35.5 (95% CI 30–36) points. The visual analog scale decreased from 5.5 (95% CI 4–7) pre-operatively to 1.5 (95% CI 1–2) points at last follow-up. No implant-specific complications occurred. ConclusionsConversion of cemented RTKA with firmly attached cemented stems, without evidence of loosening, to arthrodesis might be a surgical treatment strategy for patients with a long-established extensor mechanism insufficiency that cannot be reconstructed.

A prospective study of surgical management of bicondylar schatzker type V &amp; VI tibial plateau fracture by dual plating and dual incision

Aim: To assess the clinical and functional outcome of surgically treated Bicondylar Tibial schatzker type V and VI plateau fractures with dual plating at SSIMS-RC, Davanagere during August 2015 TO August 2018.Objectives 1. To assess the anatomical reduction of articular surface of upper end of tibia perfectly by operative treatment with internal fixation.2. To assess the radiological union of fractures after internal fixation with dual plating3. To assess the clinical outcome associated with this treatment modality a. Knee Range of movementsb. Pain relief c. Return to normal activities and work Materials and Methods: Total number of cases studied were 30. Inclusion criteria: All skeletal mature patients with proximal tibia fracture Schatzker type V and VI (>18years), AO Muller type 41-C1, 41-C2, 41-C3, Gustilo-Anderson type I and II compound proximal tibial fractures.Exclusion Criteria: Patients with Gustilo- Anderson Type 3 compound tibial plateau fractures, Children with proximal tibial fractures in whom the growth plate is intact, patients with pathological proximal tibial fractures apart from osteoporosis. Observation and Results: Our study used Honkonen Jarvinen Criteria for radiological, functional, clinical outcome which showed excellent to good result.Our study reported Honkonen Jarvinen Clinical outcome to be 86% excellent, 11.7% good and 1.7% fair. The functional outcome was 81% excellent, 13% good, 5% fair and 1% poor. The Radiological outcome showed 79.2% excellent, 12% good, 0.70% fair results.Conclusion: From this study we conclude that, surgical management of bicondylar tibial plateau fractures with dual plating gives excellent anatomic reduction, accurate axial and articular alignment with rigid internal fixation by dual locking plate, achieving a stable and functional knee joint.

Revision Meniscal Repair - Failure rates, clinical outcome and patient satisfaction

Aims and Objectives: Failure of isolated primary meniscal repair must be expected in 14% - 28%. Patients requiring revision surgery may benefit from revision meniscal repair, however, the results of revision meniscal repair remain unclear. The purpose of this study was therefore to evaluate the clinical outcome and failure rates of revision meniscal repair in patients with re-tears or failed healing after previous isolated meniscal repair in stable knee joints. Materials and Methods: A chart review was performed to identify all patients undergoing revision meniscal repair between 08/2010 and 02/2016. Only patients without concomitant procedures, without ligamentous insufficiency, and a minimum follow-up of 24 months were included. The records of all patients were reviewed to collect patient demographics, injury patterns of the meniscus, and details about primary and revision surgery. Follow-up evaluation included failure rates, clinical outcome scores (Lysholm Score, KOOS Score), sporting activity (Tegner scale), and patient satisfaction. Results: A total of 12 patients with a mean age of 22 ± 5 years were included. The mean time between primary repair and revision repair was 27 ± 21 months. Reasons for failed primary repairs were traumatic re-tears in 10 patients (83%) and failed healing in two patients (17%). The mean follow-up period after revision meniscal repair was 43 months. Failure of revision meniscal repair occurred in 3 patients (25%). In two of these patients, re-revision repair was performed. At final follow-up, the mean Lysholm Score was 95.2 with a range of 90-100, representing a good to excellent result in all patients. The final assessment of the KOOS subscores also showed good to excellent results. The mean Tegner scale was 6.8 ± 1.8, indicating a relatively high level of sports participation. Ten patients (83%) were either very satisfied or satisfied with the outcome. Conclusion: In patients with re-tears or failed healing after previous isolated meniscal repair, revision meniscal repair results in good to excellent knee function, high level of sports participation, and high patient satisfaction. The failure rate is comparable to isolated meniscal repair. Therefore, revision meniscal repair is worthwhile in order to save as much meniscal tissue as possible.