Knee Stability Research Articles

Enhancing stability and outcomes in young Indian footballers: The synergistic effect of anterior cruciate ligament reconstruction with lateral extra-articular tenodesis – A prospective observational cohort study

Objectives: Anterior cruciate ligament (ACL) tears are frequently seen injuries in young footballers that can contribute to chronic knee instability, meniscal injuries, and increased risk of early-onset osteoarthritis if not properly treated. Materials and Methods: This study evaluated the clinical findings of combined ACL reconstruction and lateral extra-articular tenodesis (LET) in 22 male footballers aged 20–30. ACL reconstruction was carried out using hamstring autografts and LET was done utilizing a modified Lemaire procedure with iliotibial band autograft. Clinical findings were studied preoperatively and at six months and one year postoperatively utilizing the International Knee Documentation Committee (IKDC) and Tegner–Lysholm scores. Results: Mean IKDC and Tegner-Lysholm scores were similar or slightly improved at six months compared to pre-operative baselines and further increased at one year follow-up, with the improvements being statistically significant. There are no cases of graft failure occurred. Conclusion: A combination of ACL reconstruction and LET is a safe and effective treatment for ACL tears in young footballers, which can restore knee stability and allow them to go back to sports. Adding LET to ACL reconstruction may help lower the likelihood of graft failure in this high-risk population.

Randomized Controlled Study Comparing Hamstring Graft and Peroneus Longus Tendon Graft in Arthroscopic ACL Reconstruction.

Graft choice for anterior cruciate ligament reconstruction (ACLR) has been evolving. The peroneus longus tendon (PLT) has been seen as a suitable choice for ACLR, providing comparable results to those of hamstring tendon (HT) autograft, but its clinical relevance in terms of return to sports, to our knowledge, has not been studied. One hundred and twenty patients who sustained an isolated ACL injury were enrolled and underwent ACLR using tripled or quadrupled PLT autograft (if graft thickness exceeded 10 mm then tripled) or quadrupled HT autograft. Patients were followed for 24 months. Functional scores (International Knee Documentation Committee [IKDC] and Tegner-Lysholm scores) were assessed preoperatively and at 3, 6, 12, and 24-month post-operatively. Graft diameter and graft harvesting time were measured intraoperatively. Donor-site morbidity was evaluated using subjective evaluation. Time to return to sports in both groups was compared. The mean diameter of the PLT autograft was significantly larger than that of the HT autograft, and the mean graft harvesting time was less (P < 0.001). Patients in the PLT group returned to sports a mean of 36 days earlier than those in the HT group (P < 0.001) and had a lower rate of donor-site morbidity, and better patient-reported outcomes at the knee (P < 0.001). There was a significant difference between the groups in IKDC and Tegner-Lysholm scores at the 24-month follow-up. Despite some donor site complications, such as numbness and infection, both PLT and HT grafts offer acceptable knee stability. However, PLT grafts seem to provide superior subjective functional outcomes based on patient-reported scores. More research is needed to further establish these findings and optimize graft choices for individual patients.

Evaluation of Lateral and Medial Parts of the Hamstring Muscle Fatigue Symmetry in Professional Footballers Cleared to Play After ACL Reconstruction.

Objectives: Rupture of the anterior cruciate ligament (ACL) is a severe injury common in sports. It also has a high rate of re-injury. The aim of this work was to assess hamstring muscle fatigue in active football players after ACL reconstruction who were cleared to play and to determine symmetry between the lateral and medial hamstring muscles. Methods: In professional football players post ACL reconstruction (n = 25) and non-injured players (n = 26), the bioelectrical activity of the medial (biceps femoris-BF) and lateral (semimembranosus and semitendinosus-SEM) hamstring muscles was measured during 60 s of isometric contraction. The fatigue variables were calculated using the Continuous Wavelet Transform (CWT) tool. Results: The football players following ACL reconstruction demonstrated significant asymmetry in fatigue of the lateral and medial hamstring muscles, with greater fatigue in the SEM compared to the BF muscle. Moreover, in those after reconstruction, the changes are more pronounced, with higher muscle fatigue in both limbs (they have lower MDF than non-injured players) and more severe SEM muscle insufficiency (noted in both limbs but with greater intensity in the non-operated one). Conclusions: The higher SEM muscle fatigue observed in this study influenced the lateral-to-medial activation ratio within the hamstring muscle, which may be a probable cause of this muscle's insufficiency in laterally stabilizing the knee in the frontal and transverse plane. Furthermore, the hamstring muscles after reconstruction were more fatigued in both limbs, which may be another risk factor for ACL graft rupture. Therefore, increased fatigue in specific hamstring muscles may indicate the direction in which knee stabilization is compromised due to ACL overload. A muscle that becomes fatigued and inefficient more quickly also becomes ineffective in performing its function sooner, which can lead to increased overloading forces acting on the ACL graft.

MCL augmentation using a peroneus longus split tendon autograft satisfactorily restores knee stability with no impairment in foot function and with a low failure rate for concurrent ACL reconstruction.

Addressing grade 2 and 3 medial-sided instabilities during anterior cruciate ligament (ACL) reconstruction is crucial to reduce the risk of ACL graft failure. This study introduced a minimally invasive, medial collateral ligament (MCL) augmentation technique using a peroneus longus split tendon autograft, which was fixed to the femoral deep MCL insertion and tibial superficial MCL insertion. This prospective, longitudinal, single-centre case series included patients who underwent MCL augmentation concurrent with primary or revision ACL reconstruction due to anteromedial instability. Preoperatively and at 1-year follow-up, clinical examinations, such as rolimeter test of anterior tibial translation and medial instability, knee (International Knee Documentation Committee subjective knee form [IKDC], Lsyholm, Knee Injury and Osteoarthritis Outcome Score [KOOS]) and foot function scores (American Orthopaedic Foot and Ankle Society score [AOFAS]) and complications, were analyzed. Thirty-one patients with a mean follow-up of 13.5 ± 2.6 months and a mean age of 27.8 ± 9.6 years were included. The side-to-side difference for anterior tibial translation significantly improved from preoperative to 1-year follow-up with an ACL reconstruction failure rate of 6.5%. No patient retained a grade 2 or 3 medial instability on valgus stress testing with 30° flexion. Significant improvements from preoperative to 1-year postoperative follow-up were observed in knee function scores: IKDC (48.9 ± 26.9- 71.3 ± 11.5, p < 0.001) and Lysholm (59.9 ± 28.5-80.5 ± 11.2, p = 0.002) as well as KOOS pain, ADL, sport and QoL, each reaching the respective minimal clinically important difference values. The foot function score AOFAS showed no significant impairment (100 ± 0-99.3 ± 2.5, p = 0.250). Complications included cyclops lesions of ACL reconstruction in three patients. At 1-year follow-up, MCL augmentation using a peroneus longus split tendon autograft for patients simultaneously undergoing ACL reconstruction satisfactorily restores knee stability, has a low ACL reconstruction failure rate and does not significantly impair foot function. Level IV therapeutic study; case series.

The Development and Reliability of a Surface Electromyography-Based Index for Quantifying Knee Muscle Coactivation During the Lower Quarter Y-Balance Test

This study aimed to develop and evaluate the reliability of a surface electromyography-based (sEMG) index to quantify knee muscle coactivation in healthy recreational athletes during the Lower Quarter Y-Balance Test (YBT-LQ). A prospective observational repeated measures design was used to assess both intra- and inter-rater reliability. Forty males completed three trials, with two raters independently conducting assessments. sEMG signals from the vastus medialis, vastus lateralis, biceps femoris, and semitendinosus muscles were collected to calculate four coactivation indices (CoAIs) for different muscle pairs. The reliability evaluation of these CoAIs was based on intraclass correlation coefficients. The results revealed that the reliability of the CoAIs varied depending on the muscle pair, direction, and limb examined. The highest intra- and inter-rater reliability was noted for the left lower limb in the posterolateral direction. The lowest reliability was found for the right lower limb in the anterior direction. Statistical analyses indicated significant differences in specific CoAIs across different YBT-LQ directions. These findings highlight the potential of sEMG-based CoAIs for assessing knee muscle activity during the YBT-LQ in healthy male recreational athletes. However, choosing CoAIs is critical for reliable clinical and research assessments of knee stability and neuromuscular control.

Functional knee stability in elite field hockey depends on playing class and gender

Field hockey, a physically demanding Olympic sport, carries a high risk of lower limb injuries, yet data on injury risk in elite field hockey are limited. Functional knee stability is important for injury prevention and a safe return to sport. This study is the first to investigate functional knee stability in elite field hockey, considering gender and playing class, and establishes reference data for functional knee stability by using a standardized test battery that assesses one- and two-legged stability, jumping tests, speed, and agility. 72 elite field hockey players, 30 males and 42 females (age 19.82 ± 3.74 years) were divided into High Playing Class (HPC) and Moderate Playing Class (MPC). HPC players showed significant better performance in all functional tests except balance tests (p &lt;0.01-0.024). Females showed significantly better one- and two-leg stability (p &lt;0.01) with lower injury rates, indicating the relevance of gender considerations. The study emphasizes the importance of balance and stability in the prevention of lower limb injuries in Olympic field hockey and also highlights the importance of considering pre-existing deficits in functional knee capability when assessing athletes for return to sport. These results can help improve athletic performance, identify individual strengths and weaknesses, prevent injury or re-injury, and facilitate return to sport after injury.

Effect of Graft Choice for ACL Reconstruction on Clinical Outcomes in Combined ACL and MCL Injuries: Comparison Between Bone-Patellar Tendon-Bone and Hamstring Autografts.

Background/Objectives: The optimal graft, particularly in combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries, remains controversial. We evaluated the influence of graft choice between bone-patellar tendon-bone (BPTB) and hamstring autografts on clinical outcomes in combined ACL and MCL injuries. Methods: This retrospective analysis included patients with concurrent ACL and MCL injuries who underwent single-bundle ACL reconstruction with BPTB (group B) or hamstring (group H) grafts, between 2010 and 2019, with a ≥2-year follow-up. Patients were classified based on the MCL injury grade (I, II, or III). Clinical outcomes were assessed through knee stability evaluations using valgus stress radiographs and the KT-2000 arthrometer, patient-reported outcomes using the International Knee Documentation Committee (IKDC) subjective score and Lysholm score, and radiologic outcomes using the IKDC radiographic grade. Results: The study included 169 patients (group B, 92; group H, 77). No significant between-group differences in knee stability or functional outcomes were found after follow-up. Within the same MCL injury grade, particularly in high-grade MCL injuries, BPTB grafts resulted in significantly better medial stability (side-to-side difference in medial joint opening on valgus stress radiographs: grade II, p = 0.006; grade III, p = 0.039) and functional outcomes (IKDC subjective score: grade II, p = 0.045; grade III, p = 0.038) than hamstring grafts. In the hamstring group, higher-grade MCL injuries were associated with worse outcomes (Lysholm knee score, p = 0.009; IKDC subjective score, p = 0.015). Conclusions: Graft choice in ACL reconstruction with concomitant MCL injuries may affect clinical outcomes, particularly in high-grade MCL injuries. Although both graft types performed similarly overall, BPTB grafts provided superior medial stability and functional results in higher-grade MCL injuries. However, caution is needed when interpreting these results due to limitations such as the small sample size and the lack of randomization in graft selection.

Arthroscopic Fixation of Posterior Cruciate Ligament Tibial Bony Avulsion Fractures: The Double Suture Bridge Technique and Evaluation of Results

Background: Surgical fixation is required for displaced posterior cruciate ligament (PCL) tibial bony avulsion fractures or with fractures having grade 2 or more posterior instability. The purpose of this study is to evaluate the results of arthroscopic fixation of PCL tibial bony avulsion fractures using the double suture bridge technique. Methods: A retrospective study was done involving 24 patients having displaced PCL tibial bony avulsion fractures. The arthroscopic double suture bridge technique was used to fix these fractures. Patients were followed up for three years and assessed for knee-related symptoms, signs, Lysholm Knee Score, and satisfaction. Results: The study group consisted of 21 men and three women. Fracture union was achieved in all cases two months postoperatively. The mean Lysholm Knee Score at follow-ups of three months, six months, one year, two years, and three years was 86.6, 96.5, 98.8, 99.1, and 99.4, respectively. At the latest follow-up, all the patients were satisfied with their knee function with respect to pain, range of motion (ROM), stability, and resumption of pre-injury activity level. Conclusion: The arthroscopic double suture bridge technique is an effective method for the fixation of PCL tibial bony avulsion fractures with respect to knee stability, ROM, and resumption of pre-injury activity level.

Comparison of a full tibial tunnel or an all-inside technique for anterior cruciate ligament reconstruction: An observational study.

This study aims to compare the effectiveness of anterior cruciate ligament (ACL) reconstruction performed with either a full tibial tunnel technique or an all-inside technique. Data from patients with ACL rupture who underwent ACL reconstruction using autogenous hamstring tendon grafts between January 2019 and July 2021 were retrospectively reviewed. Patients were followed up for a minimum of 24 months. Preoperative and postoperative International Knee Documentation Committee scores, Lysholm knee scores, visual analog scale pain scores, Tegner activity scale scores, C-reactive protein levels, erythrocyte sedimentation rate, white blood cell (WBC) count, D-dimer levels, and neutrophils were recorded. At the final follow-up, side-to-side differences were assessed with the pivot shift test, Lachman test, anterior drawer test, and a knee laxity-testing device. This study included 135 patients with ACL rupture, with 62 patients (43 males and 19 females, mean age: 34.42 ± 12.79 years) undergoing the full tibial tunnel technique, and 73 patients (58 males and 15 females, mean age: 32.41 ± 11.01 years) undergoing the all-inside techniques (AITs). There were no significant differences in postoperative International Knee Documentation Committee scores, Lysholm knee scores, or Tegner activity scale scores, except at postoperative 6 months. visual analog scale pain scores showed significant improvement in patients that underwent the AIT compared to the full tibial tunnel technique at postoperative 1 week, 2 weeks, and 1 month; however, there were no significant differences at postoperative 3, 6, 12, 18, and 24 months. C-reactive protein levels, erythrocyte sedimentation rate, WBC count, D-dimer levels, and neutrophils were significantly lower in patients that underwent the AIT compared to the full tibial tunnel technique at postoperative 1 month, but there were no other significant differences in these outcome measures, except for WBC count at postoperative 3 months. There was no significant difference in knee stability at the last follow-up. In ACL reconstruction, functional outcomes following the AIT are satisfactory and similar to the total tibial tunnel technique, but patients experience less pain and a reduced early postoperative inflammatory response. These results highlight the promising potential of AITs in the clinical management of ACL rupture and advocate for their widespread adoption.

Midterm Outcomes After Osteochondral Allograft Transplantation in the Knee Using High–Chondrocyte Viability Grafts

Background: Osteochondral allograft transplantation (OCAT) has become a standard-of-care treatment option for patients with large symptomatic articular defects. Recent advances in allograft science and OCAT protocols have been reported to result in consistently robust outcomes after OCAT in the knee. However, only short-term comparisons have been reported, and analyses are lacking for treatment failure risk factors that account for confounding variables. Hypothesis: Midterm functional graft survival rate would exceed 80% for all OCATs combined, with consideration of risk factors for lower survivorship including older patient age, higher body mass index (BMI), tibiofemoral bipolar OCAT, and nonadherence to prescribed postoperative rehabilitation protocols. Study Design: Case series; Level of evidence, 4. Methods: Patients with outcome data available at ≥5 years after primary OCAT using high chondrocyte–viability (HCV) osteochondral allografts were analyzed according to 2 clinically relevant definitions: (1) initial treatment failure, defined by revision or arthroplasty surgery performed for the primary OCAT at any time point during the study period; and (2) functional graft failure, defined by documented conversion to arthroplasty after primary or revision OCAT at any time point during the study period. Analyses were used to assess outcomes for each definition, separately for age group, sex, obesity status, tobacco use, type of OCAT surgery, osteotomy status, concurrent ligament surgery status, and adherence to postoperative protocols. Kaplan-Meier analyses were used to assess differences in survival rates, and Cox proportional hazards models were used to assess risk factors and multivariable relationships with survival. Patient-reported outcome measures for pain, function, mobility, and satisfaction were also analyzed. Results: Analysis included 137 primary knee OCATs performed in 134 patients with a mean follow-up of 66 months (59 female, 75 male; mean age, 37.8 years; mean BMI, 28.5). The midterm (5- to 8-year) functional graft survival rate for patients undergoing primary OCAT in the knee using HCV grafts was 82% for all cases combined, ranging from 69% for tibiofemoral bipolar HCV OCATs to 89% for patellofemoral bipolar, 94% for multisurface unipolar, and 97% for single-surface unipolar. Initial treatment failure rates (revision or arthroplasty after primary OCAT) and OCAT nonsurvival rates (arthroplasty after primary or revision OCAT) were greater for older patient age, concurrent ligament reconstruction, tibiofemoral bipolar OCAT, and nonadherence to the prescribed postoperative rehabilitation protocols. When adjusted for patients’ age, BMI, and tobacco use status, different surgery types did not demonstrate an increased risk for failure, while concurrent ligament reconstruction and nonadherence did. Patients who experienced functional graft survival after primary OCAT reported significantly greater improvements in PROMIS Physical Function and Mobility (Patient-Reported Outcomes Measurement Information System), International Knee Documentation Committee questionnaire, and Single Assessment Numeric Evaluation scores such that they were significantly higher at final follow-up as compared with patients who required arthroplasty. Patient-reported improvements in pain, function, and mobility exceeded minimal clinically important differences for ≥5 years after primary OCAT. When asked if they were satisfied with primary OCAT surgery, 76.2% of patients were very satisfied or satisfied with their results, while 8.5% were neutral and 15.4% were unsatisfied or very unsatisfied. Conclusion: With use of HCV osteochondral allografts, midterm (5- to 8-year) functional graft survival rates for patients undergoing primary OCAT in the knee were notably higher than previously reported midterm rates for traditional OCATs. When adjusted for patient characteristics, risk factors for nonsurvival included concurrent ligament reconstruction for knee instability and nonadherence to the prescribed postoperative rehabilitation protocols. Patients who experienced functional graft survival for ≥5 years after primary OCAT reported statistically significant and clinically meaningful improvements in pain, function, and mobility.

Strategies for Preventing Tunnel Convergence in Multiligament Knee Injury Reconstructions.

Multiligament knee injuries (MLKIs) are complex and heterogeneous, often associated with concomitant injuries, and necessitates precise treatment strategies. Effective preoperative management in MLKIs requires comprehensive evaluation, starting with a detailed patient history to identify the mechanisms of injury and prior treatments. Physical examination assesses for knee stability, while imaging techniques including magnetic resonance imaging (MRI) and radiographs detail ligament, cartilage, and meniscal injuries to identify all injured structures. Vascular evaluations are critical given the high risk of concomitant neurovascular injuries especially in dislocated knees, bicruciate injuries, and lateral-sided injuries. Anatomic reconstruction of the torn ligaments has been biomechanically and clinically validated to improve knee stability and function. When performing multiple anatomic reconstructions, the risk of tunnel convergence is high. Therefore, surgical intervention aimed at optimizing outcomes necessitates careful planning to avoid tunnel convergence. This involves strategic tunnel placement, orientation, and techniques, such as adjusting tunnel angulation and using intraoperative imaging. These measures are vital for restoring knee functionality and minimizing future complications. Managing tunnel convergence is vital in treating MLKIs. Avoiding convergence on the medial side of the femur and tibia is more challenging due to the number of tunnels. In an MLKI involving all ligaments, 4 femoral tunnels and 4 tibial tunnels are required on the medial side, compared to 3 on the femur and 1 on the tibia for the lateral side, respectively. The successof a multiligament knee reconstruction depends on a precise diagnosis, thorough preoperative management, and strategic tunnel placement. A multidisciplinary approach not only enhances surgical outcomes, but also ensures long-term improvement in knee function, effectively addressing the complexities and risks associated with these injuries.

Which technique provides more benefits in return to sports and clinical outcomes after anterior cruciate ligament reconstruction: Double-bundle or single-bundle? A randomized controlled study.

The achievement of an optimal return to sport (RTS) has remained a key goal after sports-related injuries, with the ongoing debate on the effectiveness of different surgical approaches for anterior cruciate ligament (ACL) rupture. This study aims to assess clinical outcomes and RTS across various surgical methods, such as anatomical single-bundle reconstruction (ASBR), central-axial single-bundle reconstruction (CASBR), and double-bundle reconstruction (DBR). A randomized clinical trial was conducted, comprising 191 patients who underwent ACL rupture. These patients were divided into three groups based on the ACL reconstruction techniques they received (ASBR, CASBR, DBR). Over the 2-year follow-up period, the study assessed RTS through four single-hop tests, isokinetic extension tests, and limb asymmetry indices. Postoperative graft status was determined using the signal-to-noise quotient (SNQ), while knee function was evaluated using the International Knee Documentation Committee 2000 (IKDC-2000) score, Lysholm score, Tegner score, and degree of knee laxity. A binary logistic regression model was developed to forecast the factors influencing ideal RTS. DBR (67.63%) and CASBR (58.00%) exhibited higher RTS passing rates compared to ASBR (30.39%; χ2=19.57, P<0.05). Quadriceps strength symmetry in the lower limbs was identified as the key determinant of RTS (χ2=17.08, P<0.05). The RTS rate was influenced by SNQs of the graft's tibial site (odds ratio: 0.544) and quadriceps strength of the reconstructed knee joint at 60°/s (odds ratio: 6.346). Notably, the DBR group showed enhanced knee stability, evidenced by superior results in the Lachman test (χ2=13.49, P<0.01), objective IKDC-2000 (χ2=27.02, P=0.002), and anterior instability test (χ2=9.46, P <0.01). Furthermore, DBR demonstrated superior clinical outcomes based on the Lysholm score (DBR: 89.57±7.72, CASBR: 83.00±12.71, ASBR: 83.21±11.95; F=10.452, P<0.01) and IKDC-2000score (DBR: 90.95±7.00, CASBR: 84.64±12.68, ASBR: 83.63±11.41; F=11.78, P<0.01). For patients with ACL rupture, more ideal RTS rate and clinical outcomes were shown in the DBR group than in the ASBR and CASBR groups. Autograft status and quadriceps strength are postively related to RTS. ClinicalTrials.gov (NCT05400460).

Prospective comparative study between peroneus longus tendon autograft and hamstring tendons autograft in single bundle ACL reconstruction

ABSTRACT Background ACL reconstruction is often regarded as the most effective approach of restoring knee stability. Several graft possibilities are available, including (BPTB), four-strand hamstring autografts, quadriceps tendon, and peroneus longus tendon. Each has both advantages and cons. This study compares the effectiveness of peroneus longus and hamstring tendon autografts for single bundle ACL restoration. Patients and Methods The study involved 60 patients. Thirty of them had their torn anterior cruciate ligaments reconstructed arthroscopically using hamstring tendons, while the other 30 had their ACLs managed arthroscopically with peroneus longus tendon. The follow-up period lasted at least 12 months. Patients were assessed using IKDC score and Lysholm score. Ankle function was assessed using AOFAS score. Results There was a statistically significant difference in preoperative and postoperative range of motion improvement in each group as an IKDC score item. However, no statistically significant difference existed between both groups. A statistically significant change in Lysholm scores preoperatively and postoperatively in each group was detected, but there was no statistical difference between groups 1 and 2, either in terms of improvement or percentage improvement. The AOFAS score was used also to assess for any donor site morbidity. No significant difference was detected between both ankles range of motion and no ankle joint dysfunction or problems with sports activities. Conclusion The current study found that the PL tendon autograft might be considered a safe, effective and a technically easy graft option for ACLR. The research shows no substantial difference in postoperative knee stability or graft failure rate between hamstring and peroneus tendons.

Kaplan fibers of iliotibial band: a comprehensive review of current literature.

This review highlights the pivotal role of Kaplan fibers (KFs) in knee stability, particularly in the anterolateral aspect. Studies reveal their complex anatomy with varying attachments to the distal femur, demonstrating a significant impact on knee joint mechanics across different populations. Investigations into the biomechanics of KFs show their crucial role in maintaining rotational stability of the knee, especially during rotational movements. Their synergistic function with other knee structures, like the anterolateral ligament, is emphasized, underscoring their importance in knee integrity and function. MRI emerges as a key tool in detecting KFs, with varying visibility and prevalence of injuries. The review discusses the development of MRI criteria for accurate diagnosis, highlighting the need for further research to refine these criteria and understand the interplay between KF injuries, anterior cruciate ligament (ACL) ruptures, and associated knee pathologies. The review covers various lateral extra-articular tenodesis (LET) techniques used to address residual laxity and instability following ACL reconstruction. Among them, the modified Lemaire technique, which resembles the anatomical and functional characteristics of distal KFs, shows effectiveness in reducing internal rotation and residual laxity. The review emphasizes the need for further research to understand the healing dynamics of KF injuries and the efficacy of different LET techniques. It suggests that a comprehensive approach, considering both biomechanical and clinical aspects, is crucial for advancing knee joint health and rehabilitation.

Survival and functional outcomes after hemiarthroplasty in children with proximal tibial osteosarcoma

BackgroundTreatment options for correcting limb-length discrepancy after limb-salvage reconstruction for proximal tibial osteosarcoma in children have several limitations. Therefore, we aimed to evaluate the feasibility, complications, prognosis, and clinical outcomes of reconstruction using hemiarthroplasty after tumor resection in pediatric patients with proximal tibial osteosarcoma.MethodsWe conducted a comprehensive retrospective analysis of the data of pediatric patients with osteosarcoma of the proximal tibia who underwent surgery between December 2008 and November 2018 at our center. We enrolled 49 consecutive patients who underwent hemiarthroplasty. The cruciate ligaments of all patients were reconstructed using special spacers, and the medial and lateral collateral ligaments of the knee and joint capsule were reconstructed using a mesh. Postoperatively, if the unequal length of both lower limbs exceeded 4 cm or knee instability occurred, a second-stage surgery was performed for limb lengthening and replacing the distal femoral prosthesis. We analyzed the oncological prognosis, complications of hemiarthroplasty, postoperative stability, and postoperative function.ResultsThe follow-up period ranged between 11 and 159 months, with a median of 84 (62, 129) months. The overall 5-year survival rate was 83.2%. Thirty-nine patients survived at the end of the follow-up period with 34 prostheses (87.2%). The overall prosthesis survival rate was 87.4% after 5 years, indicating the long-term benefits of the procedure. Limb length was measured in 28 adult patients. The average limb-length discrepancy was 33 ± 15 mm with a median of 33 mm (21, 47); the femur and tibia caused a discrepancy of 8.5 ± 9.9 mm and 24.8 ± 15.5 mm, respectively. The patients had 30–135° of knee motion, with a mean of 82 ± 24°. The femoral tibial angle was greater on the affected side than on the healthy side, with a mean difference of 4.5°±3.6°. The Musculoskeletal Tumor Society (MSTS) score was 25 ± 3. Five patients underwent second-stage distal femoral prosthesis replacement, with mean MSTS scores of 24 ± 2 and 28 ± 1 before and after second-stage surgery, respectively.ConclusionsHemiarthroplasty in children reduces limb-length discrepancy in adulthood by rebuilding cruciate ligaments, lateral collateral ligaments, and the joint capsule, thereby improving knee stability.

A Flat Reconstruction of the Medial Collateral Ligament and Anteromedial Structures Restores Native Knee Kinematics: A Biomechanical Robotic Investigation

Background: Injuries of the superficial medial collateral ligament (sMCL) and anteromedial structures of the knee result in excess valgus rotation and external tibial rotation (ER) as well as tibial translation. Purpose: To evaluate a flat reconstruction of the sMCL and anteromedial structures in restoring knee kinematics in the combined MCL- and anteromedial-deficient knee. Study Design: Controlled laboratory study. Methods: Eight cadaveric knee specimens were tested in a 6 degrees of freedom robotic test setup. Force-controlled clinical laxity tests were performed with 200 N of axial compression in 0°, 30°, 60°, and 90° of flexion: 8 N·m valgus torque, 5 N·m ER torque, 89 N anterior tibial translation (ATT) force, and an anteromedial drawer test consisting of 89 N ATT force under 5 N·m ER torque. After determining the native knee kinematics, we transected the sMCL, followed by the deep medial collateral ligament (dMCL). Subsequently, a flat reconstruction of the sMCL with anteromedial limb, mimicking the function of the anteromedial corner, was performed. Mixed linear models were used for statistical analysis (P < .05). Results: Cutting of the sMCL led to statistically significant increases in laxity regarding valgus rotation, ER, and anteromedial translation in all tested flexion angles (P < .05). ATT was significantly increased in all flexion angles but not at 60° after cutting of the sMCL. A combined instability of the sMCL and dMCL led to further increased knee laxity in all tested kinematics and flexion angles (P < .05). After reconstruction, the knee kinematics were not significantly different from those of the native state. Conclusion: Insufficiency of the sMCL and dMCL led to excess valgus rotation, ER, ATT, and anteromedial tibial translation. A combined flat reconstruction of the sMCL and the anteromedial aspect restored this excess laxity to values not significantly different from those of the native knee. Clinical Relevance: The presented reconstruction might lead to favorable results for patients with MCL and anteromedial injuries with an anteromedial rotatory knee instability.

A Robotic Clamped-Kinematic System to Study Knee Ligament Injury.

Knee ligament injury is among the most common sports injuries and is associated with long recovery periods and low return-to-sport rates. Unfortunately, the mechanics of ligament injury are difficult to study in vivo, and computational studies provide limited insight. The objective of this study was to implement and validate a robotic system capable of reproducing natural six degree-of-freedom clamped-kinematic trajectories on human cadaver knees (meaning that positions and orientations are rigidly controlled and resultant loads are measured). To accomplish this, we leveraged the field's recent access to high-fidelity bone kinematics from dynamic biplanar radiography (DBR), and implemented these kinematics in a coordinate frame built around the knee's natural flexion-extension axis. We assessed our system's capabilities in the context of ACL injury, by moving seven cadaveric knee specimens through kinematics derived from walking, running, drop jump, and ACL injury. We then used robotically simulated clinical stability tests to evaluate the hypothesis that knee stability would be only reduced by the motions intended to injure the knee. Our results show that the structural integrity of the knee was not compromised by non-injurious motions, while the injury motion produced a clinically relevant ACL injury with characteristic anterior and valgus instability. We also demonstrated that our robotic system can provide direct measurements of reaction loads during a variety of motions, and facilitate gross evaluation of ligament failure mechanisms. Clamped-kinematic robotic evaluation of cadaver knees has the potential to deepen understanding of the mechanics of knee ligament injury.

Knee proprioception, muscle strength, and stability in Type 2 Diabetes Mellitus- A cross-sectional study

BackgroundThe burgeoning prevalence of Type 2 Diabetes Mellitus (T2DM) has been linked to a spectrum of health complications, including those affecting the musculoskeletal system. Knee proprioception, muscle strength, and stability are essential for maintaining functional mobility and preventing falls, yet their relationship with T2DM is not fully elucidated. ObjectivesThis study aimed to compare knee proprioception, muscle strength, and limits of stability (LOS) between individuals with T2DM and asymptomatic controls and to examine the moderating role of physical activity on these relationships. MethodsIn a cross-sectional design, 192 participants (96 with T2DM and 96 asymptomatic) underwent assessments for knee proprioception using a digital inclinometer, muscle strength via a handheld dynamometer, and LOS through dynamic posturography, graded as a percentage of maximum lean without losing balance. ResultsOur analysis revealed that individuals with T2DM demonstrated reduced knee muscle strength, with mean differences of 12.90 Nm (right) and 18.80 Nm (left) in 25° of flexion, and 25.78 Nm (right) and 26.36 Nm (left) in 40° of flexion, compared to asymptomatic controls. Proprioception errors were greater in the T2DM group (p < 0.001), with significant deficits noted in both knee 25° of flexion and 40° of flexion. Stability limits were also compromised, with the T2DM group displaying a decreased ability to maintain balance across all tested directions (p < 0.001). Physical activity emerged as a positive moderator, with higher activity levels correlating with improved muscle strength and stability. ConclusionT2DM significantly impairs musculoskeletal function, highlighting the need for integrated management strategies. The study underscores the importance of physical activity in mitigating T2DM-related musculoskeletal deterioration, suggesting that therapeutic interventions should include a focus on enhancing muscle strength and stability to improve the quality of life in this population.

Resorption characteristics of an open architecture biocomposite interference screw after ACL reconstruction.

Absorbable interference screws for anterior cruciate ligament reconstruction (ACLR) can lead to tunnel widening and cyst formation. The Biosure Regenesorb interference screw (Smith & Nephew). has been developed with an optimised calcium phosphate/polymer composition to promote bone formation during resorption. The present study aims to investigate screw resorption, new bone formation, and tunnel geometry following ACLR with Biosure Regenesorb screw tibial fixation. The study is a prospective single-centre case series of 12 patients with ACL lesions and treated with ACLR using hamstring tendon autograft with Biosure Regenesorb interference screw tibial fixation with a two-year follow-up period. The Biosure Regenesorb consists of 65% polylactide-glycolic acid poly. 20% calcium sulphate and 15% tricalcium phosphate. Primary endpoint: Tunnel volume. implant volume and new bone formation in the tibial tunnel is evaluated by quantitative computed tomography (CT) scanning. Secondary endpoints: Arthrometric knee laxity, International Knee Documentation Committee (IKDC) and Knee Osteoarthritis and Injury Outcome Scores (KOOS) and Tegner activity scale. Screw volume decreased to 44% within the two-year follow-up period while tunnel volume remained unchanged. Only a minor amount (<1% of tunnel volume) of new bone formation in the screw remnants was observed. Sagittal knee laxity at one year was 0.9 mm. The IKDC score increased by 15 points and the KOOS sport and KOOS quality of life scores increased by 25 and 26 points. respectively. ACLR using Biosure Regenesorb interference screw does not result in tunnel widening. showing a screw resorption of 44% after two years and minor new bone formation. Knee stability and subjective outcome improvements are as expected after other ACLR methods. IV.

Posterior Lateral Meniscal Root Repair Through Lateral Tunnel and Anterior Cruciate Ligament Revision: How to Avoid Tunnel Overlapping

Posterior lateral meniscal root (PLMR) tears are commonly observed in conjunction with anterior cruciate ligament (ACL) injuries. The presence of PLMR tears exacerbates knee instability, increasing stress on ACL grafts and accelerating joint degeneration if left untreated. Anatomical repair of PLMR tears is therefore crucial for restoring native knee kinematics and reducing tibiofemoral contact pressures, thereby safeguarding the ACL graft. However, the standard use of a single medial tunnel approach for concomitant PLMR and revision ACL reconstruction may require reconsideration to prevent the potential risks of tunnel overlapping, which could undermine graft anatomical integrity. This article, to prevent the risk of tunnel overlapping, introduces a surgical approach that employs an additional lateral tibial tunnel for PLMR repair, instead of the typically used single medial one, for PLMR repair during simultaneous revision ACL reconstruction.