Knee Stability Research Articles

Estimating the Reliability and Validity of the Quadrant Hop Test in the Assessment of the Functional Stability of the Knee.

Background Many sporting activities demand multidirectional skills and movements, emphasizing the importance of various fitness components such as functional stability, strength, power, endurance, and range of motion. These aspects must be thoroughly assessed before athletes can return to sports safely following an injury. Although the single-leg hop test (SHT) is widely used as the gold standard for evaluating joint stability, it has limitations in assessing multidirectional movements. Therefore, further research is necessary to explore whether increasing the dynamicity of the hop test in different directions enhances its sensitivity in assessing knee joint stability across all four directions. The objective of this study was to investigate the applicability of a new functional assessment tool, the quadrant hop test (QHT), for evaluating lower limb functional stability. Methodology One hundred nineteen amateur sportsmen who are in the age group of 18-25 years with a limb symmetry index of the lower limb calculated through SHT of >80% were included. All the participants performed the SHT, a triple hop test (THT), a crossover hop test (CHT), and the QHT on two different days, with two investigators assessing the QHT on different days and then recording the measurements of Hop distance. Results The mean difference between SHT, THT, and CHT with QHT was 4.59%, with a moderate correlation between all the hop tests. The Cronbach's alpha revealed good intra-rater (0.917) and inter-rater reliability (0.912) of the QHT. Conclusion The QHT proves to be a reliable and valid measure for assessing the functional stability of the lower limb and is 4.59% more sensitive than SHT, THT, and CHT in assessing knee stability and in return to sports criteria.

In Vitro Assessment of Knee Joint Biomechanics Using a Virtual Anterior Cruciate Ligament Reconstruction.

Understanding the biomechanical impact of injuries and reconstruction of the anterior cruciate ligament (ACL) is vital for improving surgical treatments that restore normal knee function. The purpose of this study was to develop a technique that enables parametric analysis of the effect of the ACL reconstruction (ACLR) in cadaver knees, by replacing its contributions with that of a specimen-specific virtual ACLR that can be enabled, disabled, or modified. Twelve ACLR reconstructed knees were mounted onto a motion simulator. In situ ACLR graft forces were measured using superposition, and these data were used to design specimen-specific virtual ACLRs that would yield the same ligament force-elongation behaviors. Tests were then repeated using the virtual ACLR in place of the real ACLR and following that in ACL deficient knee by disabling the virtual ACLR. In comparison to the ACL deficient state, the virtual ACLRs were able to restore knee stability to the same extent as real ACLRs. The average differences between the anterior tibial translation (ATT) of the virtual ACLR versus the real ACLR were +1.6 ± 0.9 mm (p = 0.4), +2.1 ± 0.4 mm (p = 0.4), and +1.0 ± 0.9 mm (p = 0.4) during Anterior drawer, Lachman and Pivot-shift tests, respectively, which is small in comparison to the full ATT range of motion (ROM) of these knees. Therefore, we conclude that a virtual ACLR can be used in place of real ACLR during biomechanical testing of cadaveric knees. This capability opens the door for future studies that can leverage parameterization of the ACLR for surgical design optimization.

Externally validated treatment algorithm acceptably predicts nonoperative treatment success in patients with anterior cruciate ligament rupture.

This study aims to develop and externally validate a treatment algorithm to predict nonoperative treatment success or failure in patients with anterior cruciate ligament (ACL) rupture. Data were used from two completed studies of adult patients with ACL ruptures: the Conservative versus Operative Methods for Patients with ACL Rupture Evaluation study (development cohort) and the KNee osteoArthritis anterior cruciate Ligament Lesion study (validation cohort). The primary outcome variable is nonoperative treatment success or failure. Potential predictor variables were collected, entered into the univariable logistic regression modeland then incorporated into the multivariable logistic regression model for constructing the treatment algorithm. Finally, predictive performance and goodness-of-fit were assessed and externally validated by discrimination and calibration measures. In the univariable logistic regression model, a stable knee measured with the pivot shift test and a posttrauma International Knee Documentation Committee (IKDC) score <50 were predictive of needing an ACL reconstruction. Age >30 years and a body mass index > 30 kg/m2 were predictive for not needing an ACL reconstruction. Age, pretrauma Tegner score, the outcome of the pivot shift testand the posttrauma IKDC score are entered into the treatment algorithm. The predictability of needing an ACL reconstruction after nonoperative treatment (discrimination) is acceptable in both the development and the validation cohort: area under the curve = resp. 0.69 (95% confidence interval [CI]: 0.58-0.81) and 0.68 (95% CI: 0.58-0.78). This study shows that the treatment algorithm can acceptably predict whether an ACL injury patient will have a(n) (un)successful nonoperative treatment (discrimination). Calibration of the treatment algorithm suggests a systematical underestimation of the need for ACL reconstruction. Given the limitations regarding the sample size of this study, larger data sets must be constructed to improve the treatment algorithm further. Level II.

An anteromedial stabilization procedure has the most protective effect on the anterior cruciate ligament in tibial external rotation. A human knee model study

IntroductionAnterior cruciate ligament (ACL) reconstruction remains associated with the risk of re-rupture and persisting rotational instability. Additional extraarticular anterolateral stabilization procedures stabilize the tibial internal rotation and lead to lower ACL failure rate and improved knee stability. However, data for additional stabilization of tibial external rotation is lacking and the importance of an anteromedial stabilization procedure is less well evaluated. Aim of this study is to investigate the influence of an extraarticular anteromedial stabilization procedure for the stabilization of the tibial external rotation and protection of the ACL from these rotational forces.MethodsInternal and external rotations of the tibia were applied to a finite element (FE) model with anatomical ACL, posterior cruciate ligament (PCL), lateral collateral ligament (LCL), medial collateral ligament (MCL) and intact medial and lateral meniscus. Five additional anatomic structures (Anteromedial stabilization/anteromedial ligament, AML, augmented superficial medial collateral ligament, sMCL, posterior oblique ligament, POL, anterolateral ligament, ALL, and popliteal tendon, PLT) were added to the FE model separately and then combined. The force histories within all structures were measured and determined for each case.ResultsThe anteromedial stabilization or imaginary AML was the main secondary stabilizer of tibial external rotation (90% of overall ACL force reduction). The AML reduced the load on the ACL by 9% in tibial external rotation which could not be achieved by an augmented sMCL (-1%). The AML had no influence in tibial internal rotation (-1%). In the combined measurements with all additional structures (AML, ALL, PLT, POL) the load on the ACL was reduced by 10% in tibial external rotation.ConclusionThis study showed that an additional anteromedial stabilization procedure secures the tibial external rotation and has the most protective effect on the ACL during these external rotational forces.

Efficacy of Intraoperative Platelet-Rich Plasma After Meniscal Repair: Systematic Review and Meta-analysis.

Meniscal injuries frequently require surgical intervention to restore knee joint function and stability. Intraoperative platelet-rich plasma (PRP) injection has emerged as a potential adjunctive therapy to enhance tissue healing post-meniscal repair. This systematic review and meta-analysis aimed to evaluate the efficacy of PRP in terms of pain relief, functional recovery, and overall success rates in patients undergoing meniscal repair procedures. A comprehensive search strategy was employed to identify relevant studies across Scopus, PubMed, Embase, and the Cochrane Library databases. The inclusion criteria encompassed human studies, including randomized controlled trials (RCTs), cohorts, and case-control studies, focusing on intraoperative platelet-rich plasma (PRP) use post-meniscal repair and reporting outcomes related to pain, functionality, and cure rates. Exclusion criteria comprised animal studies, non-English publications, studies lacking relevant outcome measures, and those with insufficient data. Two reviewers independently screened titles and abstracts, resolving disagreements through consensus or consultation with a third reviewer, followed by a full-text assessment for potentially eligible studies. Data extraction was conducted independently by two reviewers using a standardized form. The reliability of observational studies was evaluated using the Newcastle-Ottawa Scale. Subgroup analyses and pooled effect estimates for main outcomes were computed using RevMan 5.3, a meta-analysis tool. The demographic analysis revealed that the PRP group had an average age of 41.39years, while the control group had an average age of 42.1years. In terms of gender distribution, the PRP group consisted of 61 men and 29 women, while the control group had 62 men and 34 women. Pain ratings showed a preference for PRP with a mean difference of 4.83 (p = 0.13). However, there was no significant difference in Lysholm scores (mean difference: - 0.44, p = 0.91) or IKDC scores (mean difference: 2.80, p = 0.14) between the PRP and control groups. Similarly, ROM measures did not show a statistically significant difference, with a mean difference of 2.80 (p = 0.18). Additionally, there was no significant distinction in failure rates between the PRP and control groups, as indicated by a weighted mean difference of 0.71 (p = 0.52). These findings suggest that while PRP may offer some benefits in pain relief, its impact on functional recovery, range of motion, and failure rates following meniscal repair procedures is inconclusive. The current evidence regarding the effect of intraoperative platelet-rich plasma (PRP) injection on patients undergoing meniscal repair remains inconclusive. While some studies suggest potential benefits in terms of pain relief and functional recovery, others show no significant differences compared to control groups. The impact of PRP therapy on overall success rates, including rates of re-tear and revision surgery, is also uncertain. Further well-designed randomized controlled trials with larger sample sizes are needed to provide more robust evidence and guide clinical practice in orthopedic surgery.

Reasons for Not Returning to Pre-injury Sport Level After ACL-Reconstruction.

The study aimed to identify athlete-reported reasons for not returning to pre-injury sports level after anterior cruciate ligament reconstruction (ACLR) and to identify the factors associated with these reasons. Ninety-one athletes with 2 years post-ACLR indicated whether or not they had returned to their pre-injury sport level (same frequency, duration, and intensity). Athletes who did not return were asked to provide the reasons. Athletes' characteristics and injury-related factors were used to determine factors associated with the reasons for not returning. Only nine athletes (10%) returned to pre-injury sport level after ACLR. The most common reasons for not returning were lack of confidence or concerns about re-injury (48.8%), followed by continued post-surgical impairments in the reconstructed knee (39%). Having episodes of the knee giving way after ACLR was the only significant predictor of post-surgical impairments (48.8%; OR=8.3, 95%CI=2.48-27.42, p=0.001). Lack of confidence, concerns about re-injury, or post-surgical impairments in the reconstructed knee were the most frequently reported reasons for not returning to pre-injury sports level with 2 years post-ACLR. Reported dynamic knee instability was the only factor associated with ongoing post-surgical knee impairments after ACLR. Rehabilitation programs should address athletes' psychological responses and resolve knee impairments to optimize return to pre-injury sport level after ACLR.

New Anatomic Anterolateral Ligament Reconstruction Used in a Complex Revision ACL Reconstruction

Background: Anterior cruciate ligament reconstructions (ACLRs) are performed to restore knee biomechanics, increase knee stability, and slow the progression of osteoarthritis. After ACLRs, many patients still have residual anterolateral instability which is a risk factor for ACL graft failure. An anterolateral ligament reconstruction (ALLR) attempts to restore the native function of the anterolateral complex to augment the ACL. Performing an ALLR with an ACLR has been reported to reduce symptoms of instability and improve clinical outcomes. Indications: While no definitive indication for an ALLR has been set, current considerations include high posterior tibial slope &gt;12°, revision ACLR, high-grade pivot shift, skeletally immature patients, hyperlaxity, and patients in high-level sports. Technique Description: The preoperative assessment includes a thorough physical examination with special attention paid to rotational laxity assessed via the pivot-shift examination. Imaging should include standard radiographic series (anteroposterior, posteroanterior flexion, lateral, and sunrise views), long-leg mechanical axis views to assess coronal plane alignment and standing lateral ACL stress radiographs to assess sagittal alignment and objective instability. The iliotibial band ALLR graft is harvested first. An 8-cm long by 1-cm wide strip of the inferior iliotibial band is harvested in a standard fashion, leaving the distal aspect attached to Gerdy’s tubercle. An anchor is placed centered upon the native ALL distal tibial insertion. The native ALL femoral origin is identified at 4.7 mm posterior and proximal to the fibular collateral ligament, and a second suture anchor is placed at this point. Final fixation is performed after the final fixation of the ACLR graft. Results: A study by Pioger et al reported that patients with ACLR and ALLR had significantly less reoperation rate than patients with isolated ACLR, 8.9% versus 20.5% respectively. Lee et al found that a revision ACLR in combination with an ALLR was effective in reducing rotational laxity, which was assessed by the pivot-shift test. Discussion: We describe a technique for a new anatomic ALLR using the iliotibial band that attempts to restore the native ALL anatomy. This surgical technique effectively restores rotational laxity and improves knee stability. Patient Consent Disclosure Statement: 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.

Fibrin Clot–Augmented Meniscal Repair

Background: Failure rate of meniscal repair can reach 25%. Multiple techniques have been used to increase meniscal healing, notably biological augmentation techniques. One of them is fibrin clot–augmented meniscal repair, which will be described in this video. Indications: This technique is indicated mainly for the lesions with a high failure rate. This includes large, horizontal, and radial tears and even for meniscal cysts, especially in a stable knee. This technique can also be used in revision meniscal suture when failure is no longer an option. Surgical Technique: Fibrin clot is prepared from sterile peripheral venous blood from the patient. A plastic syringe is used to stir the blood in a sterile glass container. The fibrin clot is then formed and washed rigorously with saline solution. Rolling the fibrin clot which is fixed to the syringe allows to give the fibrillar aspect of the clot. The formed fibrin clot is now solid enough to be manipulated and can be fixed to a vicryl suture thread allowing it to enter the knee and be fixed inside the meniscal lesion. The clot is wrapped inside the meniscal lesion with inside-out or outside-in suture technique. Results: We used this technique for multiple types of lesions, like bucket handle meniscal tear, horizontal meniscal cleavage, parrot beak tear, and even in lesions within white-white zone. The postoperative protocol is the same as standard inside-out meniscal repair. This technique has been used in the literature with promising results. Conclusion: The fibrin clot–augmented meniscal repair is a demanding but promising technique. We need further follow-up to confirm its effectiveness. Patient Consent Disclosure Statement: 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.

Functional Outcome of Single-Bundle Arthroscopic Anterior Cruciate Ligament Reconstruction using Peroneus Longus Graft and Hamstring Graft: An Open-Label, Randomized, Comparative Study.

Background This study investigates the functional outcomes of single-bundle arthroscopic anterior cruciate ligament (ACL) reconstruction, comparing the use of two distinct graft sources: peroneus longus (PL) graft and hamstring graft. The choice of graft material in ACL reconstruction is crucial for optimal postoperative results, and this study aims to contribute valuable insights into the comparative efficacy of these two graft types. Method This open-label randomized comparative study involved a carefully selected cohort of patients undergoing single-bundle arthroscopic ACL reconstruction. Participants were randomly assigned to either the PLgraft group or the hamstring graft group. Surgical procedures were conducted using standardized techniques, and postoperative rehabilitation protocols were closely monitored. Functional outcomes, including range of motion, stability, and patient-reported measures, were assessed at predefined intervals to ensure comprehensive data collection. Results The study underscores significant demographic and clinical factors in ACL reconstruction outcomes. Participants were predominantly aged 17-30 years (58.33%) with a mean age of 29.27 years and exhibited a male predominance (80.56%). Common complaints included knee pain and instability, primarily due to falls from bikes (55.56%) or sports-related trauma (44.44%). Notably, PL grafts demonstrated advantages over hamstring grafts, with longer mean length (10.11 mm vs. 8.77 mm, p=0.0001) and shorter operation times. Visual analog scale (VAS), International Knee Documentation Committee(IKDC), and Tegner Lysholm scores show no significant differences between grafts over the period of time. There is no notable foot eversion weakness or significant donor site morbidity after the PL graft harvest.Hamstring graft cases exhibit a higher incidence of altered sensation and muscle atrophy, suggesting the potential benefits of PL grafts for improved surgical outcomes. Conclusions Graft comparisonsfavored PL grafts due to longer length, and functional outcome assessments between the two graft types. However, foot and anklestrength assessments revealed fluctuations in strength recovery with PL grafts, highlighting the need for tailored rehabilitation. Thigh circumference variations suggested potentialmuscle atrophy in the hamstring graft group, along with reported paresthesia in theipsilateral proximal leg. In conclusion, PL grafts offer potential advantages for ACL surgery, but ongoing monitoring and specialized rehabilitation are crucial.

Comparison of Side-to-Side Difference in Posterior Tibial Slope in Knees With Acute Versus Chronic Anterior Cruciate Ligament Deficiency.

The posterior tibial slope (PTS) is an important feature in knee joint biomechanics and indicates anterior-posterior knee stability. Increased PTS is a known risk factor for both primary anterior cruciate ligament (ACL) rupture and postreconstruction rerupture. To investigate the effect of long-term exposure to ACL deficiency on the PTS and the sagittal anatomy of the proximal tibia. Cross-sectional study; Level of evidence, 3. A total of 44 patients (38 men, 6 women) with a history of knee injury and ACL rupture confirmed by magnetic resonance imaging and physical examination were included in this study. Patients were divided into those with chronic ACL deficiency (group 1: injured ≥5 years prior; n = 22) and acute ACL deficiency (group 2: injured <1 year prior; n = 22). The medial and lateral tibial plateau PTS and anterior tibial translation were measured on monopodal weightbearing knee radiographs at 20° of flexion. The mechanical tibiofemoral angle (MTFA) and the medial proximal tibial angle (MPTA) were measured using an orthoroentgenogram. The side-to-side difference between the affected and unaffected knees was also calculated for all measurements. The mean duration of exposure to ACL deficiency was 7.6 years (range, 5-15 years) in group 1 and 4.4 months (range, 1-11 months) in group 2. Regarding the side-to-side differences in angular measurements, a higher medial PTS (affected vs unaffected: 12.4° vs 10.1°; P = .007), higher lateral PTS (11° vs 8.9°; P = .011), and increased varus alignment on both the MTFA (4.3° vs 2.4°; P = .036) and the MPTA (84.9° vs 86.3°; P = .033) were found in group 1, while no significant differences in angular measurements were found in group 2. Compared with group 2, patients in group 1 had a significantly higher side-to-side difference in the medial PTS (2.3° vs 0.1°; P = .0001), lateral PTS (2.1° vs 0.4°; P = .0001), and MPTA (1.4° vs 0.1°; P = .002). This study showed that the affected knees of patients with chronic ACL deficiency (≥5 years) had higher medial and lateral PTS compared with the unaffected contralateral knees. Therefore, when planning ACL reconstruction for patients with a history of long-term ACL deficiency, it is crucial to measure the preoperative PTS accurately.

Case report of a new technique for with posterior cruciate ligament avulsion fractures treated with a mini transverse incision

Posterior cruciate ligament (PCL) is a strong stabilising ligament of the knee joint originating from posterior part of Intercondylar eminence oof tibia and attaches to the anterior part of medial surface of lateral condyle of femur. The PCL plays a major role in knee stabilization, and are statistically one of the rarest injuries around the knee. Due to the surrounding neurovascular elements in the popliteal space, very few open approaches to repair such injury were performed. The ‘‘safe transverse mini-incision approach’’ to PCL avulsion fracture is a simple approach, does not require exploration of the neurovascular elements, and produced satisfactory results in the majority of patients.

Exploring the Morphometric Variations of Knee Menisci: Implications for Meniscal Injury and Surgical Interventions in Orthopedic Practice

Background: The knee menisci are pivotal for knee biomechanics and stability, yet meniscal injuries remain prevalent, necessitating a detailed understanding of meniscal morphology for effective clinical management. This study investigates the morphometric variations of knee menisci and their implications for injury mechanisms and orthopedic interventions. Material &amp; Methods: A cross-sectional study was conducted on 30 cadavers with intact knee joints. Morphometric parameters of the medial and lateral menisci were measured using digital calipers. Statistical analysis, including correlation analyses and significance testing, was performed using SPSS version 23 to explore associations between meniscal dimensions and knee morphology. Results: Significant variations in meniscal dimensions were observed, both within individuals and between the medial and lateral menisci. Correlation analyses revealed nuanced relationships between different morphometric parameters. Notably, weak correlations were found between meniscal dimensions and the lengths of adjacent bones, suggesting a complex interplay between meniscal morphology and knee anatomy. For instance, the correlation coefficient between the length of the femur and the outer circumference of the right medial meniscus was 0.215 (p = 0.291), indicating a moderate positive correlation, although not statistically significant. Similarly, the correlation coefficient between the length of the tibia and the inner circumference of the left lateral meniscus was -0.315 (p = 0.091), suggesting a moderate negative correlation, which also did not reach statistical significance. Conclusion: This study provides valuable insights into knee meniscal morphometry and its clinical implications. The findings emphasize the importance of considering meniscal dimensions in diagnosing and managing meniscal injuries. Despite limitations such as sample size and the use of cadaveric specimens, the results contribute to orthopedic knowledge and highlight the need for further research to validate and expand upon these findings.

ACL Reconstruction with Peroneus Longus Autograft Using Endobutton &amp; Bioabsorbable Interference Screw and Brace Free Rehabilitation

Objective: To assess the functional outcome of arthroscopic anterior cruciate ligament (ACL) reconstruction with Peroneus longus tendon autografts using endobutton and interference screw at one-year follow-up post- operatively and brace-free rehabilitation. Material and Methods: A prospective study included 53 patients with clinical and radiological ACL deficiency. Arthroscopic ACL reconstruction was performed using Peroneus Longus double bundle autografts with sub- sequent brace-free rehabilitation. Pre- and postoperative assessment at one-year follow-up utilized the International Knee Documentation Committee (IKDC) score. Graft length and diameter were measured perioperatively, and donor site morbidity was evaluated using The American Orthopedic Foot and Ankle Score (AOFAS). Results: The study included 51 (94.4%) males and 2 (3.7%) females, mean age 27.3±7.2 years. Majority were left-sided procedures (64.8%). Peroneus Longus graft mean length and diameter were 116.8±5.3mm and 8.2±0.2mm respectively. At one-year follow-up, ankle joint movement at the graft site was preserved (mean AOFAS 98±0.8). There was a significant improvement in IKDC score postoperatively (p &lt; 0.05). Conclusions: ACL reconstruction with Peroneus longus autograft offers knee stability and facilitates early rehabilitation. Utilizing endobutton and bioabsorbable interference screw fixation supports graft strength until sufficient graft-to-bone healing occurs. Patients regain pre-injury activity levels, including stair climbing, sitting cross-legged, and squatting without difficulty.

Prolonged Physiotherapy after Anterior Cruciate Ligament Reconstruction Does Not Improve Muscular Strength and Function.

Background: After the rupture of the anterior cruciate ligament (ACL), surgery is proposed in the case of knee instability or for athletes who want to return to a pivotal and/or contact sport. The current trend is to extend physiotherapy sessions until a patient's return to sport. We aimed to assess the interest in prolonging the physiotherapy sessions up to 4 postoperative months to restore muscle knee strength and function. Methods: From a historical cohort, 470 patients (24.3 ± 8.7 years) were included; 312 (66%) were males. They all had undergone a primary ACL reconstruction with a hamstring procedure. The number of physiotherapy sessions was established at 4 postoperative months. The main study parameters to assess the benefit of prolonged physiotherapy were the isokinetic limb symmetry index (LSI) for the quadriceps and the hamstrings as well as the Lysholm score. Results: At 4 postoperative months, 148 patients (31.4%) still had physiotherapy sessions. This group had performed 49 ± 14 physiotherapy sessions at the time of evaluation compared to 33 ± 9 sessions performed by the group that stopped physiotherapy at 3 months post-ACL reconstruction. The isokinetic knee LSI and the Lysholm score were not different between the two groups. Continued physiotherapy sessions were associated with female gender, previous high sport level, meniscal repair, lateral tenodesis and outpatient rehabilitation at the beginning of the rehabilitation management, while knee pain complications were not associated. Conclusions: No significant correlation was found between the number of physiotherapy sessions and the knee strength LSI or the Lysholm score. Prolonging patient physiotherapy sessions after 3 months post-ACL reconstruction seems ineffective in improving knee strength recovery and function.

Return to Sports After Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament (ACL) tears are one of the most common orthopedic injuries among athletes. Although a small proportion of patients with isolated tears can return to sports after completing a nonsurgical rehabilitation program, ACL reconstruction is frequently recommended for young athletes, especially those with concomitant knee injuries or symptomatic knee instability. Alongside emerging evidence for the effect of prehabilitation, the current standard of care for postoperative ACL physical therapy includes pain control, range of motion, quadriceps strengthening, weight bearing, postoperative bracing, and dynamic limb stabilization and control. The early rehabilitation period includes non-weight-bearing exercises and passive range of motion, which is followed by a longer period of gradual strengthening focused on regaining preinjury strength, proprioception, and control with progressively more demanding dynamic movements. The total rehabilitation period is expected to take around 9 months, during which the patient should be evaluated at frequent intervals by a licensed physical therapist in addition to a daily home exercise program. Prior to discharge from the rehabilitation program, patients should be evaluated by both the surgeon and physical therapist. Patients are encouraged to return to sports once they meet a set of perceptual, subjective, objective, neuromuscular, functional, sport-specific drills, and load management testing criteria.

Nanosurgical and Bioengineering Treatment of Human Anterior Cruciate Ligament Tears with Ultrasound-Guided Injection of Modified Platelet-Rich Plasma Using Human Cell Memory Based on Clinical, Ultrasound, MRI, and Nanoscope Analyses: A Double-Blind Randomized Trial.

Background: Anterior cruciate ligament (ACL) tears account for 40% to 50% of all ligamentous knee injuries. Most patients with ACL ruptures undergo surgical treatment. There is currently no objective, well-documented, repeatable, and standardized nonsurgical method for ACL tear treatment. This study aimed to investigate ACL outcomes in patients who underwent a novel nanosurgery and bioengineering treatment (NSBT) for an ACL tear. Methods: This was a double-blind randomized trial including 44 patients with a history of traumatic knee injury and a confirmed ACL tear. The final sample comprised 40 patients who met all the eligibility criteria. The patients were divided into two groups: the treatment group (n = 30) and the control group (n = 10). The treatment group underwent nanosurgery with an ultrasound-guided injection of modified platelet-rich plasma (PRP) using human cell memory (RP-hCM). The control group was treated with an ultrasound-guided PRP injection into the joint capsule. At baseline and post-treatment, all patients underwent both ultrasonography and magnetic resonance imaging (MRI), and the following clinical variables were assessed: the WOMAC score, the Lysholm knee score, the visual analog scale score, and knee instability. In most patients, the clinical outcome was verified using nanoscopy. Results: The median WOMAC, VAS, and LKS scores, as well as knee instability, improved significantly 12 weeks after the procedure in the treatment group (p < 0.001). We found a significantly larger improvement in the assessed parameters in the treatment group compared to the control group (p < 0.001). In the treatment group, all the patients had good and very good clinical outcomes, while 90% of the patients had a normal ACL signal in a follow-up MRI scan. In the control group, a physical examination revealed no changes in knee stability after treatment. Conclusions: This study showed that there is a significant difference in patient experience and the duration of recovery for patients with ACL tears treated with NSBT. The novel nonsurgical method was shown to be repeatable, objective, well documented, standardized, and highly effective.

Predictive Refined Computational Modeling of ACL Tear Injury Patterns.

Anterior cruciate ligament (ACL) ruptures are prevalent knee injuries, with approximately 200,000 ruptures annually, and treatment costs exceed USD two billion in the United States alone. Typically, the initial detection of ACL tears and anterior tibial laxity (ATL) involves manual assessments like the Lachman test, which examines anterior knee laxity. Partial ACL tears can go unnoticed if they minimally affect knee laxity; however, they will progress to a complete ACL tear requiring surgical treatment. In this study, a computational finite element model (FEM) of the knee joint was generated to investigate the effect of partial ACL tears under the Lachman test (GNRB® testing system) boundary conditions. The ACL was modeled as a hyperelastic composite structure with a refined representation of collagen bundles. Five different tear types (I-V), classified by location and size, were modeled to predict the relationship between tear size, location, and anterior tibial translation (ATT). The results demonstrated different levels of ATT that could not be manually detected. Type I tears demonstrated an almost linear increase in ATT, with the growth in tear size ranging from 3.7 mm to 4.2 mm, from 25% to 85%, respectively. Type II partial tears showed a less linear incline in ATT (3.85, 4.1, and 4.75 mm for 25%, 55%, and 85% partial tears, respectively). Types III, IV, and V maintained a nonlinear trend, with ATTs of 3.85 mm, 4.2 mm, and 4.95 mm for Type III, 3.85 mm, 4.25 mm, and 5.1 mm for Type IV, and 3.6 mm, 4.25 mm, and 5.3 mm for Type V, for 25%, 55%, and 85% partial tears, respectively. Therefore, for small tears (25%), knee stability was most affected when the tears were located around the center of the ligament. For moderate tears (55%), the effect on knee stability was the greatest for tears at the proximal half of the ACL. However, severe tears (85%) demonstrated considerable growth in knee instability from the distal to the proximal ends of the tissue, with a substantial increase in knee instability around the insertion sites. The proposed model can enhance the characterization of partial ACL tears, leading to more accurate preliminary diagnoses. It can aid in developing new techniques for repairing partially torn ACLs, potentially preventing more severe injuries.

The Impact of Different Anterior Cruciate Ligament Status on Unicompartmental Knee Arthroplasty: Short Term Clinical and Functional Results

Purpose: Purpose of this study is to compare the short-term results of unicompartmental knee arthroplasty applied stable knees regardless of the condition of the ACL and the application of unicompartmental knee arthroplasty and ACL reconstruction combined surgery applied to ACL deficient cases with anterior instability and to identify the condition and function of the ACL for success in this surgery. Patients and Methods: 80 out of the 105 patients who were operated in 2013-2015 and came for follow-up were included in the study and the patients were divided into four groups. The VAS pain score, KSS Score, WOMAC score, OKS questionnaires and joint range of motion measurements were conducted pre-operatively and post-operatively. One leg standing test, joint position sense measurement, and isokinetic muscle strength test were performed in post-operative controls. Results: There was no statistically significant difference between the demographic data and follow-up of the groups (p˃0.05). While there was a statistically significant difference in knee flexion between Group 2-Group 4 and Group 3-Group 4 in the pre-operative period, no difference was found in the post-operative period (p˃0.05). While there was no difference among the groups, knee joint range of motion in direction of extension declined in a statistically significant way in all four groups (p˂0.05). Pain felt postoperatively was the most in Group 1 and the least in Group 3. A statistically significant difference was found between Group 1 and Group 3 in the test performed with the eyes closed (p˂0.05). Conclusion: The presence of a functional anterior cruciate ligament is expected to make a positive contribution to surgical results especially in young patients with high activity expectation. Whether the patient’s ACL rupture is primary or secondary and his/her activity expectation should be effective in the choice of a surgical method.

Dynamic radiostereometry can objectively quantify the kinematic laxity patterns and rotation instability of the knee during a pivot-shift test.

The pivot-shift test is used to clinically assess knee instability in patients with anterior cruciate ligament (ACL) lesions; however, it has low interobserver reliability. Dynamic radiostereometry (dRSA) is a highly precise and noninvasive method for the objective evaluation of joint kinematics. The purpose of this study was to quantify precise knee kinematics during a pivot-shift test using dRSA imaging. Eight human donor legs, including hemipelvises, were evaluated. Arthroscopic intervention was performed inducing ligament lesions in the ACL, and anterolateral ligament (ALL) section was performed as a capsular incision. The pivot-shift test was recorded with dRSA on knees with intact ligaments, ACL-deficient and ACL + ALL-deficient knees. A pivot-shift pattern was identifiable after ligament lesion, as a change in tibial posterior drawer velocity from 7.8 mm/s (95% CI: 3.7; 11.9) in ligament intact knees to 30.4 mm/s (95% CI 23.0; 38.8) after ACL lesionto 35.1 mm/s (95% CI 23.4; 46.7) after combined ACL-ALL lesion. The anterior-posterior drawer excursion increased from 2.8 mm (95% CI 2.1; 3.4) in ligament intact kneesto 7.2 mm (95% CI 5.5; 8.9) after ACL lesionto 7.6 mm (95% CI 5.5; 9.8) after combined lesion. A statistically significant increase in tibial external rotation towards the end of the pivot-shift motion was observed when progressing from intact to ACL + ALL-deficient knees (p < 0.023). This experimental study demonstrates the feasibility of dRSA to objectively quantify the kinematic laxity patterns of the knee during the pivot-shift test. The dynamic parameters obtained through dRSA revealed the kinematic changes from ACL to combined ACL-ALL ligament lesion. Not applicable.

Clinical Outcome of Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft versus Tibialis Tendon Allograft Allograft

Abstract: Objectives: The present study aimed to examine the clinical outcome of anterior cruciate Ligament (ACL) reconstruction using hamstring tendon autograft versus tibialis tendon Allograft. Materials/Patients and Methods: Local institutional review board approval (Code number 930971) was obtained before the commencement of the study. Thereafter, the patients who had undergone anatomical arthroscopic ACL reconstruction with hamstring tendon autograft and allograft tibialis were retrospectively reviewed. A number of 82 eligible Patients in autograft and 100 patients in the allograft group who met inclusion criteria were examined regarding knee stability by clinical examinations and KT-2000 arthrometer from 2008-2014. Results: Anterior drawer test was reported negative in 23.18% of patients in autograft and 23% of patients in the allograft group which was not statistically meaningful (P=0.870). The mean follow-up time was reported as 36.34 and 38.34 months in autograft and allograft groups, respectively. Final score of Knee Injury and Osteoarthritis Outcome Score (KOOS) in autograft and allograft groups was measured at 70.87±19.76 and 71.83%, respectively. In addition, the mean Lysholm score in autograft And allograft groups was reported to be 90±4.77 and 3.3±92, respectively. Moreover, Mean International Knee Documentation Committee (IKDC) score in the autograft and Allograft groups was estimated as 85±14.11 and 7.03±9, respectively. Furthermore, the Mean Kujala score in autograft and allograft groups was measured at 79±3.07 and 3.75±81, respectively. Conclusions: Apart from the mainstay treatment which is the surgical technique, the Use of quadrupled hamstring tendon autograft and tibialis allograft would yield dramatic Results in ACL reconstruction both subjectively and objectively. Moreover, the use of Hamstring tendon autograft and tibialis allograft is reported to have similar medical Results.