Terminal Knee Extension Research Articles

Postoperative Supine Sleeping Position Following Total Knee Arthroplasty Decreases Knee Flexion Contractures

Background Total knee arthroplasty (TKA) is an orthopaedic operation that improves quality of life and reduces pain in patients with disabling arthritis of the knee. One commonly recognized postoperative complication is flexion contracture of the knee. While early physical therapy and range of motion (ROM) exercises have helped improve ROM postoperatively, flexion contractures still remain a significant postoperative complication of TKA. This study evaluated postoperative sleeping position and its effect on terminal knee extension and ROM following primary TKA. We hypothesized that patients who slept in the supine position would achieve earlier knee extension and ROM when compared to those in the lateral recumbent position. Methods A total of 150 consecutive primary total knee arthroplasties (TKAs) were conducted by a single surgeon (JMC). Prospective data collection included assessments of preoperative range of motion (ROM), postoperative ROM, patient-reported outcome measures, and sleeping positions. Functional outcomes and patient-reported measures were compared between pre- and postoperative phases, as well as across different sleeping position groups. Results Postoperative follow up was a mean of 29.6 days. Mean postoperative terminal extension ROM at one month was 2.98 degrees in the supine group versus 6.03 degrees in the lateral group (P < 0.001). Overall, there was significant improvement in patient reported outcome measures (WOMAC, Oxford, and pain) after surgery, but no difference existed between sleeping groups. For knee extension, a two-way ANOVA revealed that there was a statistically significant interaction between the effects of surgery and sleep position (p = 0.0053). Conclusions Our results demonstrate that sleeping position does affect initial postoperative knee terminal extension; however, there is no effect on patient reported outcomes. We found a statistically significant difference in extension when comparing patients in the supine versus lateral group. Patients who slept in the lateral position lacked 6.03 degrees of extension which is greater than the 5 degrees threshold needed for normal gait mechanics. Conversely, those in the supine group only lacked 2.98 degrees of extension, allowing for normal gait mechanics. This study identifies an easy, effective means of increasing patient knee range of motion following TKA.

Effects of Isometric Hold Exercise with Passive Terminal Knee Extension in Restoring Quadriceps Function after ACL Reconstruction – Research design and methods

Effects of Isometric Hold Exercise with Passive Terminal Knee Extension in Restoring Quadriceps Function after ACL Reconstruction – Research design and methods

The Effect of Postoperative Sleeping Position on Knee Extension and Range of Motion Following Primary Total Knee Arthroplasty.

Total knee arthroplasty (TKA) is an orthopaedic operation that improves quality of life and reduces pain in patients with disabling arthritis of the knee. One commonly recognized complication is flexion contracture of the knee. Early physical therapy helps prevent flexion contracture and improve range of motion (ROM) postoperatively. This study evaluated postoperative sleeping position and its effect on terminal knee extension and ROM following primary TKA. We hypothesized that patients who slept in the supine position would achieve earlier knee extension and greater ROM when compared to those in the lateral recumbent position. A total of 150 consecutive primary TKAs were performed by a single surgeon (J.M.C.) from April 2014 to December 2014. The data were collected prospectively to determine preoperative ROM, postoperative ROM, and sleeping position. Mean postoperative terminal extension ROM at 1 month was 2.9 degrees in the supine group versus 6.0 degrees (p<.001) in the lateral group. No significant demographic differences between the two groups at baseline were found. Our results demonstrate that sleeping position affects initial postoperative terminal extension, however, not overall ROM. We found a statistically significant difference in extension when comparing patients in the supine versus lateral group. Patients who slept in the lateral position lacked 6 degrees of extension which is greater than the 5 degrees needed for normal gait mechanics. Those in the supine group lacked 2.9 degrees of extension, allowing for normal gait mechanics. This study identifies an easy, effective means of increasing patients initial ability to achieve knee extension and satisfaction following TKA.

A tight anterosuperior intercondylar notch may increase the risk of cyclops syndrome after anterior cruciate ligament reconstruction using a quadruple semi-tendinosus short autograft

BackgroundCyclops syndrome is loss of terminal knee extension caused by a fibrous nodule developed in the anterior intercondylar notch. The many known risk factors include preoperative motion-range limitation, tibial tunnel malposition, and tight hamstrings. The primary objective of this study was to assess whether intercondylar notch size was associated with the risk of cyclops syndrome or graft tear after anterior cruciate ligament (ACL) reconstruction using a quadruple semi-tendinosis autograft. The secondary objective was to determine whether intercondylar notch size was associated with functional outcomes. HypothesisA narrow intercondylar notch is associated with higher risks of cyclops syndrome and poor functional outcomes. MethodsConsecutive patients who underwent ACL reconstruction by quadruple semi-tendinosus autograft were included retrospectively. Preoperative magnetic resonance imaging scans were assessed by a single senior surgeon, who determined the conventional notch width index (NWI) and the anterior NWI (aNWI) for each patient. ResultsThe 120 included patients had a mean follow-up of 2.4±0.8 years. Among them, 20 (16.7%) experienced cyclops syndrome and 7 (5.8%) graft rupture. At last follow-up, 26 (21.7%) had not returned to sports and only 47 (39.2%) had returned to sports at the pre-injury level. The mean Lysholm score was 87.9±13.5 and the main subjective IKDC score was 84±13. A narrow notch was significantly associated with lower likelihoods of returning to sports (p=0.001), returning to the same sport (p<0.0001), and returning to the pre-injury sport level (p=0.004). By multivariate analysis, only the aNWI index was significantly associated with the risk of cyclops syndrome (p<0.0001). An aNWI index lower than 0.18 had 85% sensitivity and 78% specificity for predicting cyclops syndrome. ConclusionA narrow anterosuperior intercondylar notch may increase the risk of cyclops syndrome after ACL reconstruction using a quadruple semi-tendinosus graft but is not associated with the risk of graft rupture. Level of evidenceIV, retrospective observational cohort study.

Radiographic Technique for Routine Clinical Measurement of Postoperative Total Knee Extension

Introduction: We propose a novel clinical technique to easily obtain a radiographic measurement for terminal passive knee extension based upon a weight-bearing lateral radiograph. Materials and Methods: Lateral radiographs were obtained with the patient in the standing position. The leg was positioned with slight hip flexion and full passive extension of the knee by instructing the patient to bear partial weight through their heel, with simultaneous use of a wooden wedge to dorsiflex the foot to neutral and to aid in balance. A Terminal extension was measured radiographically with digital imaging software. Fifty postoperative knee radiographs were used in assessing inter-observer and intra-observer reliability. Results: Inter-observer reliability yielded an Intraclass Correlation Coefficient of 0.973. The correlation coefficient for intra-observer reliability was 0.980. Conclusion: With the use of weight-bearing extension radiographs and our measurement technique, we present a method that can easily be applied across any setting in total knee arthroplasty to obtain accurate, objective data on patient knee extension.

Additional Distal Femoral Resection Minimally Improves Terminal Knee Extension: A Systematic Review and Meta-Regression Challenging the Dogma

BackgroundAdditional distal femoral resection is a common technique to address a flexion contracture during primary total knee arthroplasty (TKA) but can lead to midflexion instability and patella baja. Prior reports regarding the magnitude of knee extension obtained with additional femoral resection have varied. This study sought to systematically review research describing the effect of femoral resection on knee extension and to perform meta-regression to estimate this relationship. MethodsA systematic review was conducted using MEDLINE, PubMed, and Cochrane databases by combining the terms (“flexion contracture” OR “flexion deformity”) AND (“knee arthroplasty” OR “knee replacement”) to identify 481 abstracts. In total, 7 articles reporting change in knee extension after additional femoral resection or augmentation across 184 knees were included. The mean value for knee extension, its standard deviation, and the number of knees tested were recorded for each level. Meta-regression was performed using weighted mixed-effects linear regression. ResultsMeta-regression estimated that each 1mm resected from the joint line produced a 2.5° gain of extension (95% confidence interval, 1.7 to 3.2). Sensitivity analyses excluding outlying observations estimated each 1mm resected from the joint line produced a 2.0° gain of extension (95% confidence interval, 1.9 to 2.2). ConclusionsEach millimeter of additional femoral resection is likely to produce only a 2° improvement in knee extension. Thus, an additional resection of 2 mm is likely to improve knee extension by less than 5°. Alternative techniques, including posterior capsular release and posterior osteophyte resection, should be considered in correcting a flexion contracture during TKA.

The sitting active and prone passive lag test: a validity study in a symptomatic knee population.

[Purpose] This study aimed to determine the diagnostic utility of the sitting active and prone passive lag test in identifying terminal extension lag in unilaterally symptomatic knees. The lack of full extension at the knee leads to greater force of quadriceps activation, overloading of the weight bearing joints, abnormal gait mechanics, resulting in pain and dysfunction. [Participants and Methods] Participants were randomly assigned and evaluated by two blinded examiners, to determine the presence of extension lag at the knee. The reproducibility of test results between examiners was determined, for reliability. In addition, the ability of the test to identify the presence of extension lag in symptomatic knees and absence of extension lag in asymptomatic knees was assessed, for validity. [Results] The results revealed the test to possess an 'almost perfect' inter-rater reliability, high sensitivity, and moderate specificity. [Conclusion] The sitting active and prone passive lag test may be incorporated as a reliable and valid test to determine the presence of terminal knee extension lag in a unilaterally symptomatic knee population.

Patella-Posterior Turning Point of the Distal Femur Distance Is a Potential Indicator for Diagnosing Patella Alta in Recurrent Patellar Dislocation Population

To introduce a simple patellar height measurement method (patella-posterior turning point of the distal femur [P-PTP] Distance) independent of patellar anatomy with standardized patient position, and tested the reliability, validity, and diagnostic accuracy compared with commonly used ratios in knee extension. We retrospectively reviewed 418 computed tomography (CT) images of the knee joint in a group of patients who were diagnosed recurrent patellar dislocation (RPD). With the three-dimensional (3D) CT reconstructed knee, patellar height was qualitatively assessed by the patellar engagement with the femoral trochlea in terminal knee extension to divide RPD population into case (patella alta) and control group. With digitally reconstructed lateral radiographs, patellar height was measured with P-PTP distance (perpendicular distances between the distal edge of patella articular surface and posterior turning point of distal femur), and four commonly used ratios: Caton-Deschamps index, Modified Insall-Salvati index, Blackburne-Peel index, and Insall-Salvati index. An unpaired t-test was conducted to determine significant differences between groups. Correlation coefficient, intra- and inter-observer reliability, receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were also calculated. 198 knee images (198 patients) were included for final evaluation. Patella alta was present in 72 knees (36.3%) with RPD. The effect size was relatively large between the case and control group for P-PTP distance (d=-1.619; 95% CI,-1.948 to-1.286). P-PTP distance correlated moderately to strongly with four commonly used ratios (P < .001). Intraobserver and interobserver reliability was good for P-PTP distance. The AUC of the ROC curve was categorized as excellent for P-PTP distance, better than other measurements (P < .001), and the cutoff value was 4.2 mm with the highest sensitivity (86.11%) and specificity (84.92%). The measurement method, P-PTP distance, showed good intra-observer and inter-observer reliability, well correlated with commonly used ratios, and presented best diagnostic accuracy among commonly used ratios for predicting RPD. P-PTP distance might be a potential indicator for identifying patella alta in RPD patients when supine and knee extended. The measurement reported in this study may help in advancing clinical evaluation of patella alta, providing an alternative and simple method to measure patellar height. Standing or weight-bearing plain lateral radiographs obtained from the routine practice should be further assessed in the next step to further validate the method.

Early Use of Blood Flow Restriction Training with Low-Intensity Exercises following Anterior Cruciate Ligament Reconstruction Improves Quadriceps Strength and Post-Operative Pain: A Randomized Controlled Trial

Objectives:Blood flow restriction therapy (BFRT) has been proposed as a method to enhance rehabilitation following anterior cruciate ligament reconstruction (ACLR). However, a paucity of data exists to support the use of BFRT in clinical practice. The purpose of this study is to determine if early application of BFRT, used with low-weight therapy exercises, increases quadriceps strength, and functional outcomes following ACLR compared to a traditional rehabilitation protocol without BFRT.Methods:Twenty-six patients undergoing ACLR were randomized to receive either: (1) a traditional rehabilitation program (n=14), or (2) a modified program using BFRT with low-weight (20-50% of 1-repetition maximum) exercises (n=12). Two patients crossed over from the control to BFRT groups. An as treated analysis was performed for biweekly measurements in the acute postoperative period of range of motion (ROM), thigh circumference, and terminal knee extension (TKE) strength. Circumference and TKE strength were analyzed as a percentage of the contralateral side. VAS and IKDC scores were assessed preoperatively and during the first 12 weeks postoperatively.Results:Compared to the control group, the BFRT patients demonstrated significantly greater TKE strength at week 8 (68.3% vs. 82.7%, p = 0.022), week 10 (69.0% vs. 82.8%, p = 0.044), and week 12 (64.4% vs. 84.2%, p = 0.002) , as well as greater overall change in TKE strength from week 3 to 12 (8.3% vs 24.4%, p = 0.044). The BFRT group reported significantly lower VAS values at week 6 (2.5 vs. 0.6, p = 0.041), though scores were similar at week 12 (0.9 vs. 1.0, p = 0.912).There was no significant difference for knee ROM, thigh circumference, or IKDC scores at any time point.Conclusions:In comparison to a traditional rehabilitation protocol following ACLR, BFRT used in conjunction with low-weight exercises during the acute postoperative period was associated with significantly lower VAS scores at week 6, as well as greater quadriceps strength at 8, 10, and 12 weeks. These results suggest that BFRT may accelerate rehabilitation after ACLR, though future studies are needed to assess long-term outcomes.

A Study to Compare the Activation of Vastus Medialis Oblique by EMG for three Different Exercises in Patient with Osteoarthrosis of Knee Joint: An Observational Study

Background and Objectives: Osteoarthritis (OA) also called as Osteoarthrosis or degenerative jointdisease,it is the most common form of common disorder of synovial joint.OA represents a major cause ofmorbidity and disability and as well as it having a significant economic burden on patients and health careresources.Dysfunction of the quadriceps muscle,specially vastus medialis (VM) ,has been hypothesized ascause of OA knee.Various studies evaluating the EMG activity for VMO in straight leg raise,knee extensionand weight bearing exercises like single leg stance to strengthen the quadriceps muscle in patient with OAknee but results are different.So,aim of the study is to compare the activation of VMO by EMG for threedifferent exercises in patients with osteoarthritis of knee joint.Methods: The study was conducted on 100 patients with OA knee with mean age of 49.36+5.58 (SD years).EMG activity of VMO was compared during MVIC with 10 RM in three different positions:1)straight legraise(SLR),2) terminal knee extension with medial rotation of hip ,3) Single leg stance at 30 degrees kneeflexion.Results : ANOVA and Tukey Kramer Multiple Comparison Test were used for statistical analysis.The resultrevealed that there is a significant increase in VMO muscle activity when testing position 1 compared withtesting position 2 and 3 but there was no significant difference was found between testing position 2 and 3.Conclusion: The result showed that terminal knee extension with medial rotation of hip and single leg stanceat 30 degrees knee flexion significantly activate the VMO than straight leg raise (SLR) .The comparison ofthese therapeutic exercises have been advanced to strengthen the quadriceps muscles and hence can be usedas early rehabilitation program in patient with OA knee.

Residual Force Enhancement Is Present in Consecutive Post-Stretch Isometric Contractions of the Hamstrings during a Training Simulation

Residual force enhancement (rFE) is observed when isometric force following an active stretch is elevated compared to an isometric contraction at corresponding muscle lengths. Acute rFE has been confirmed in vivo in upper and lower limb muscles. However, it is uncertain whether rFE persists using multiple, consecutive contractions as per a training simulation. Using the knee flexors, 10 recreationally active participants (seven males, three females; age 31.00 years ± 8.43 years) performed baseline isometric contractions at 150° knee flexion (180° representing terminal knee extension) of 50% maximal voluntary activation of semitendinosus. Participants performed post-stretch isometric (PS-ISO) contractions (three sets of 10 repetitions) starting at 90° knee extension with a joint rotation of 60° at 60°·s−1 at 50% maximal voluntary activation of semitendinosus. Baseline isometric torque and muscle activation were compared to PS-ISO torque and muscle activation across all 30 repetitions. Significant rFE was noted in all repetitions (37.8–77.74%), with no difference in torque between repetitions or sets. There was no difference in activation of semitendinosus or biceps femoris long-head between baseline and PS-ISO contractions in all repetitions (ST; baseline ISO = 0.095–1.000 ± 0.036–0.039 Mv, PS-ISO = 0.094–0.098 ± 0.033–0.038 and BFlh; baseline ISO = 0.068–0.075 ± 0.031–0.038 Mv). This is the first investigation to observe rFE during multiple, consecutive submaximal PS-ISO contractions. PS-ISO contractions have the potential to be used as a training stimulus.

Terminal knee extension deficit and female sex predict poorer quadriceps strength following ACL reconstruction using all-soft tissue quadriceps tendon autografts.

The all-soft tissue quadriceps tendon (QT) autograft is becoming increasingly popular for ACL reconstruction (ACLR); however, studies reporting strength recovery and early outcomes after QT autograft are limited with patient samples composed of predominantly males. The primary purpose was to characterize early, sex-specific recovery of strength, range of motion (ROM), and knee laxity in a large cohort of patients undergoing primary ACLR with standardized harvest technique of the all-soft tissue QT autograft. The secondary purpose was to examine the influence of demographic factors and clinical measures on 6-month quadriceps strength. Patients 14-25years who underwent primary, unilateral ACLR with all-soft tissue QT autografts were prospectively followed. Knee laxity and ROM were collected at 6weeks, 3 and 6months; while, quadriceps normalized torques and limb symmetry indices (LSI) were collected at 3 and 6months using isokinetic dynamometry at 60°/s. Two-way ANOVAs with repeated measures were conducted to determine recovery over time and between sexes. Stepwise linear multiple regressions were conducted to determine predictors of 6-month quadriceps strength. Three-hundred and twenty patients were included (18 ± 3years; 156 males:164 females; BMI = 24 ± 4kg/m2) with no early graft failures within the study period. For strength, there were significant main effects of time (p < 0.001) and sex (p < 0.001), indicating similar improvement from 3 to 6months with males demonstrating greater quadriceps LSI (6months: 72.1 vs 63.3%) and normalized strength (6months: 2.0 vs 1.6Nm/kg). A significantly higher proportion of females had knee extension ROM deficits ≥ 5° compared to males at 6weeks (61 vs 39%; p = 0.002). Female sex and 3-month extension ROM deficits were identified as significant predictors of 6-month quadriceps LSI (R2 = 0.083; p < 0.001). Female sex, BMI, and 6-week extension ROM deficits were identified as significant predictors of 6-month normalized quadriceps strength (R2 = 0.190; p < 0.001). Females had decreased quadriceps strength and greater extension ROM deficits at 3 and 6months following ACLR using all-soft tissue QT autografts. Female sex, higher BMI, and loss of extension ROM were independent predictors of poorer quadriceps strength at 6months. There were no early graft failures, and laxity remained within normal ranges for both males and females. Surgeons and rehabilitation clinicians should be aware of the increased risk of postoperative loss of extension ROM in females and its implications on quadriceps strength recovery. III.

A patient-specific lower extremity biomechanical analysis of a knee orthotic during a deep squat movement

Although knee orthotics have become the preferred treatment method for rehabilitation and injury prevention, their biomechanical influence has not yet been quantified. A new type of knee joint orthosis (KJO) using a non-linear spring-loaded (NLSL) component was recently introduced to help prevent the growing number of knee injuries and aid during rehabilitation. The purpose of this case study is to quantify the lower extremity biomechanical effects and evaluate functional benefits of a new KJO as a precision treatment option. Kinematic and kinetic data obtained from two dynamic squat trials were recorded using VICONⓇ motion capture system and an AMTIⓇ force plate. This data was then applied to a modified computational musculoskeletal model. Inverse kinematics and dynamics were performed to calculate joint angles and joint moments while a static equilibrium problem was solved at each instant during the squat cycle, with and without the NLSL KJO to find individual muscle forces of the lower extremity. The NLSL KJO was seen to improve the activation in the subject's posterior chain musculature encouraging a more balanced synergy versus the inherent quadriceps dominant strategy during the squat movement, and encourage a more neutral behavior in the upright position by inhibiting movement towards terminal knee extension.

Nonoperative Management of Minimally Displaced Patellar Sleeve Fractures.

Patellar sleeve fractures primarily occur in the adolescent population from a rapid contraction of the quadriceps with the knee in a flexed position. Several small case reports describe operative reduction and fixation for displaced fractures. However, there is sparse literature on nonoperative management of these injuries. Retrospective review and prospective follow-up of all patients diagnosed with patellar sleeve fracture between 1991 and 2014 at a single institution. Patients with superior pole avulsion fractures, history of prior knee surgery, and fractures managed operatively were excluded. Patients with a clinical diagnosis without support of advanced imaging were also excluded. Radiographs and magnetic resonance imaging (MRI) were reviewed for initial fracture displacement, time until fracture union, and the presence of patellar tendon ossification. Outcome was assessed using the Tegner's activity scale, Kujala's Score and the International Knee Documentation Committee (IKDC) subjective knee evaluation score at final follow-up. Eighteen nonoperatively treated distal patellar pole sleeve fractures were identified, while five patients had advanced imaging to support their diagnosis. All were males with a mean age of 15.1 (range: 12-18). Traumatic and sport-related injuries were noted in the majority of patients. Only one patient had any appreciable displacement, but still < 2 mm. Final radiographic evaluation revealed fracture healing without patellar tendon ossification in all patients. All five patients had full terminal knee extension and symmetric range of motion. Mean IKDC score was 96.4 (range: 82-100) mean Tegner's activity score was 60 (range: 5-8), and mean Kujala's score was 89.7 (range: 63-100) at final follow-up. Of the five cases, three patients presented in a delayed fashion, and all went on to have surgical treatment. Two required arthroscopic loose body removal, while the other had an open patellar debridement and platelet-rich plasma (PRP) injection. Minimally displaced patellar sleeve fractures can be successfully managed nonoperatively with excellent clinical outcomes. However, delayed in presentation may be associated with worse outcome. This study of case series reflects level of evidence IV.

Effect of 6-week retro or forward walking program on pain, functional disability, quadriceps muscle strength, and performance in individuals with knee osteoarthritis: a randomized controlled trial (retro-walking trial)

BackgroundPrevious studies reported the beneficial effects of walking in individual with mild to moderate knee osteoarthritis (OA). The current study aimed to compare the effect of 6-week retro versus forward walking program versus control group on pain, functional disability, quadriceps muscle strength and physical performance in individuals with knee OA.MethodsA three-arm single-blinded, randomized, controlled trial and intention-to-treat analysis was conducted in outpatient physiotherapy department, King Saud University, Saudi Arabia. Sixty-eight individuals (mean age, 55.6 years; 38 female) with knee OA participated. The participants in the retro or forward walking group completed 10 min of supervised retro or forward walking training in addition to usual care, 3 days/week for 6 weeks. The control group received a routine physiotherapy program. This program comprises a combination of closed and open kinematic chain exercises, including straight leg raising, isometric quadriceps, isometric hip adduction, terminal knee extension, semi-squat, and leg press. The primary outcomes were mean pain and knee function score measured by the numerical rating scale and the Western Ontario and McMaster Universities Osteoarthritis Index, respectively. The secondary outcomes were mean score of quadriceps muscle strength and timed up and go test scores. All the outcomes were analyzed at baseline and week 6.ResultsIn total, 68 subjects participated in this 6-week randomized, controlled trial. The completion rates of the primary and secondary outcome measures at week 6 were 91, 87, and 82% in the retro walking, forward walking, and control groups, respectively. In the intention-to-treat analysis, the retro walking group had a greater reduction in pain intensity (mean changes, 1.8 versus 1; p = 0.01) and functional disability (mean changes, 4.8 versus 2.2; p = 0.008) than the control group. Similarly, the retro walking group had a greater improvement in the quadriceps muscle strength (mean changes, 1.7 kg versus 0.7 kg; p = 0.008) and the timed up and go test (mean changes, 0.6 s versus 0.1 s; p = 0.003) than the control group.ConclusionsThe 6-week retro walking program compared with forward walking or control groups resulted in greater reduction in pain and functional disability and improved quadriceps muscle strength and performance in individuals with knee OA.Trial registrationControlled Trials ISRCTN12850845, Registered 26 January 2015.

Hamstring Co-Contraction in the Early Stage of Rehabilitation After Anterior Cruciate Ligament Reconstruction: A Longitudinal Study.

Hamstring co-contraction may affect recovery from anterior cruciate ligament reconstruction. The aim of the study was to evaluate the changes in hamstring co-contraction during the early postoperative stages. Twenty-five patients with anterior cruciate ligament reconstruction were followed up for 1-3 mos postoperatively, during which the Lysholm and International Knee Documentation Committee questionnaires were completed and surface electromyograms were assessed during terminal knee extension maximum voluntary contraction and step-up tests. The integrated electromyogram of the tested muscles and co-contraction ratio were analyzed. Co-contraction ratio during terminal knee extension maximum voluntary contraction at 3 mos postoperatively was significantly less than that at 1 mo postoperatively (P < 0.0083), and it did not significantly differ from that of the uninvolved knee. In contrast, the co-contraction ratio during step-up was significantly higher at 2 and 3 mos postoperatively than that before surgery (P < 0.0167) and for the uninvolved knee (P < 0.05). Moreover, the postoperative hamstring co-contraction ratio in patients with a chronic injury was significantly higher during the step-up test than in patients with an early injury (P = 0.017). Hamstring co-contraction ratio during terminal knee extension maximum voluntary contraction recovers during the early postoperative stages. However, hamstring co-contraction ratio during step-up, which may be related to knee joint proprioception, remains high, particularly for patients with a chronic injury. ChiCTR-COC-17011167.

Surgical Technique for Release of Anterior Interval Scarring of the Knee After Anterior Cruciate Ligament Reconstruction

Postoperative scarring is a known complication after arthroscopic anterior ligament reconstruction of the knee. The anterior interval of the knee has been previously identified as a common location for anterior scar formation. The anterior interval is defined as the space between the infrapatellar fat pad and the anterior border of the tibia. Patients with anterior interval scarring often present with lack of terminal knee extension, anterior knee pain, decreased patellar mobility, and quadriceps atrophy. The goal of this paper is to describe the technique for anterior interval release of the knee.

Лечение вывиха надколенника разгибательной формы

Purpose Evaluate efficacy of the technique offered for the treatment of patellar dislocation at terminal knee extension. Material and methods The review included 67 patients (84 knee joints) with patellar dislocation at terminal knee extension. Surgical planning with the use of Ilizarov module was based on radiological assessment, CT scans and patients’ age. Outcomes of surgical treatment of patients with patellar dislocation at terminal knee extension were followed from 1 to 13 years. Results Evaluation criteria of efficient treatment included absence of patellar dislocation, improved knee function and supportability of the limb, relief of knee pain, and the patella being fully engaged with the femoral trochlea on radiographs and CT scans of the knee joint. Conclusion The approach to the treatment of patellar dislocation at terminal knee extension facilitated excellent and good results in 97.6 % of the cases. Reoperation was required for two patients to ensure good outcome. Preoperative calculations and accurate technical performance are important for patellar tendon transfer to avoid adverse effects.

Hamstring Contracture After ACL Reconstruction Is Associated With an Increased Risk of Cyclops Syndrome.

Background:Cyclops syndrome is characterized by loss of terminal knee extension due to proliferative fibrous nodule formation in the intercondylar notch. This complication occurs in the early postoperative period after anterior cruciate ligament reconstruction (ACLR). The pathogenesis of Cyclops syndrome is not well understood.Hypothesis:Persistent hamstring contracture after ACLR is associated with an increased risk of subsequent Cyclops syndrome.Study Design:Case-control study; Level of evidence, 3.Methods:The files of 45 patients who underwent arthroscopic debridement of a Cyclops lesion after ACLR were analyzed. Recorded data included demographic information and technical details of surgery. Preoperative magnetic resonance images were also analyzed, and patients with femoral bone bruising were identified. Passive and active range of motion were recorded in all patients preoperatively and at 3 and 6 weeks after surgery to address the Cyclops lesion. Passive extension deficit was evaluated in comparison with the contralateral limb and classified as secondary to hamstring contracture when contracture was observed and palpated in the prone position and when the extension deficit was reversed after exercises performed to fatigue the hamstrings. A control group was selected using a random numbers table among our entire ACLR cohort. Statistical analysis was performed to analyze differences between the 2 groups.Results:There was no significant difference between the groups with regard to age at ACLR, sex distribution, time from injury to surgery (P > .05), proportion of professional athletes, presence of femoral bone bruise, or technical aspects of surgery. The overall extension deficit incidence was significantly higher in the Cyclops group at 3 weeks (Cyclops, 71%; control, 22%) (P < .001) and at 6 weeks (Cyclops, 60%; control, 7%) (P < .001). The extension deficit related to hamstring contracture was significantly higher in the Cyclops group at 3 weeks (Cyclops, 58%; control, 22%) (P < .001) and at 6 weeks (Cyclops, 29%; control, 2%) (P < .001).Conclusion:The Cyclops lesion is associated with a persistent hamstring contracture at 3 and 6 weeks after ACLR.

Multi-Ligamentous Knee Injury in Sports Involving Concomitant Anterior Cruciate Ligament and Patellar Tendon Disruption: A Review of Case Reports

Background:Injury to the anterior cruciate ligament (ACL) is one of the most common orthopedic injuries in the United States, while injury to the patellar tendon (PT) is less common. A combined rupture to the ACL and PT is consequentially uncommon and increases the difficulty of a correct initial diagnosis. The purpose of this paper is to critically appraise the current peer-reviewed literature regarding multi-ligamentous knee injuries (MLKI) in sport.Methods:A systematic review was undertaken to identify all relevant peer-reviewed articles regarding MLKI from March 1980 to January 2015. All articles pertaining to simultaneous rupture of the ACL and PT were included for review.Results:A total of 27 cases presented in 15 articles were used. Findings suggest that the combination of a palpable gap over the PT, a positive Lachman test, inability to complete terminal knee extension, and a superior position of the patella are clinical examination markers for a possible MLKI involving the ACL and PT.Conclusion:Simultaneous rupture to the ACL and PT is incredibly rare within the sport population, making diagnosis and treatment of such injury challenging. A thorough examination of the extensor mechanism of the knee is important in making the proper diagnosis.