Complete ACL Rupture Research Articles

Role of sagittal - oblique technique of MRI in diagnosis of anterior cruciate ligament injuries

Abstract Background Sagittal-oblique technique clearly shows partial rupture because its’ double angulation follows the specific course of the patient’s ligament, due to approximate orientation of the external rotation of the foot. Sagittal-oblique technique provides a higher number of slices presenting the whole course of ACL Objective To value the role of sagittal- oblique technique of MRI adding to the standardized MRI technique in the diagnosis of anterior cruciate ligament injuries. Patients and Methods The study was approved by the hospital ethical committee and all patients agreed to participate in the study. We prospectively evaluated 20 patients with MRI examination of the knee. Patients presented with painful knee joint due to trauma of knee soft tissue structures. They were 9 females and 11 males, ranging in age from 26 to 67 years. Mean age is 39.80 years. Results Accuracy of standard MRI protocol of the knee comparing to additional technique is identical in detection of a complete ACL rupture. Presentations of the partial ruptures of ACL using sagittal-oblique technique were more sensitive than presentation using standard MR protocol. There was statistically significant difference between MRI detection of the ruptured ACL between additional techniques. Sagittal-oblique technique provides a higher number of MRI slices showing the whole course of the ACL and requires a shorter scan time. Conclusion The addition of oblique sagittal technique to the standard MRI imaging improved diagnostic accuracy for detecting partial tear of the ACL. However, oblique sagittal technique is just as precise as the standard MR technique for the evaluation of a complete rupture of the ACL, so it should be used in cases of suspicion of partial rupture of the ACL

Varus Stress Injury to the Knee During Soccer

The patient was a 24-year-old man who presented to a direct-access clinic 1 day following a noncontact trauma to the right knee while sprinting during soccer. The patient was evaluated by a dual-licensed physical therapist and nurse practitioner. Following examination, the patient was referred for radiographs, due to acute twisting trauma and knee effusion. Radiographs revealed an avulsion fracture at the tibial plateau, commonly known as a Segond fracture. Magnetic resonance imaging 2 days later revealed a complete ACL rupture, a tear in the posterior horn of the lateral meniscus, and improved visualization of the Segond fracture. JOSPT Cases 2021;1(2):124–125. doi:10.2519/josptcases.2021.10256

Does kinesiotaping can improve static stability of the knee after anterior cruciate ligament rupture? A randomized single-blind, placebo\u2010controlled trial

BackgroundThe aim of the study was the assessment of the early impact of the selected kinesiotaping technique on the static stability of the knee joint in patients with ACL rupture on the basis of stabilographic parameters.MethodsSixty-two patients with a complete ACL rupture (32 patients in experimental group and 30 patients in placebo group) took part in the randomized single-blind, placebo-controlled trial. The ligament technique of KT was taken into consideration. Application of a KT tape only on the injured knee was to stabilize the knee joint. Experimental group had application of KT on the injured knee and the placebo group had a KT placebo application (with no tension on KT). Intervention and stabilographic test in both groups was the same.Research tools included measurements of static stabilographic parameters on stabilometric platform CQStab2P®. Outcome measures were assessed before intervention and after KT application. The analysis included evaluation of outcome variables – total path length, (SP), statokinesiogram path length in the XY axes (SPML, SPAP), and mean velocities in the XY axes (MV, MVML, MVAP).ResultsThe results show a statistically significant shortening of the SP, SPAP and SPML variables only in experimental group. In the placebo group the results were not significant. The analysis also showed a significant improvement in all analyzed variables in the experimental group compared to the healthy side. In the placebo group, the results did not improve significantly after KT application compared to the healthy side.ConclusionsApplication of KT in patients after ACL rupture shortened the total path length and improved the value of parameters in the frontal and sagittal planes in experimental group, which may suggest the potentially greater improvement in these parameters. By improving the values of the analyzed variables, the KT application is able to compensate for the loss of static stability of the knee.Trial RegistrationThis study was registered retrospectively in the Australian New Zealand Clinical Trials Registry (ANZCTR). Registration number: ACTRN12616001407482.

Injury and illness epidemiology in professional Asian football: lower general incidence and burden but higher ACL and hamstring injury burden compared with Europe

BackgroundWhile football injury and illness epidemiology surveillance at professional club level in Europe is available, epidemiological data from other continents are lacking.PurposeInvestigating injury and illness epidemiology in professional Asian football.Study...

Greater medial tibial slope is associated with increased anterior tibial translation in females with an ACL-deficient knee.

The purpose of the study was to determine the correlation between medial tibial slope (MTS) and anterior tibial translation (ATT) in female patients with an ACL-deficient knee. It was hypothesized that female patients with a greater medial tibial slope had an increased anterior tibial translation compared to males. MTS and ATT were analysed in 276 patients (138 females and 138 males) with a complete ACL rupture from 2012 to 2016. The mean age was 32 ± 12years. Previous surgery or additional ligament injury was excluded. CT scan was used for measuring MTS. Meniscal findings were reported. Anterior tibial translation and side to side difference (SSD) were measured by bilateral Telos™ stress radiography with knee flexion of 20°. There was no significant difference in ATT between females (5.4 ± 3.9) and males (5.8 ± 4.2), nor was there a difference in MTS between females (9.8 ± 2.8) and males (9.8 ± 2.7). A positive correlation was found between MTS and ATT absolute (r = 0.35, p < 0.001) and side to side difference (r = 0.12, p = 0.03). MTS greater or equal to 11° significantly increased the ATT (p < 0.05). For each degree of increase of the MTS, increases in ATT absolute of 0.6mm and SSD of 0.18mm were observed. Greater MTS was identified as a risk factor for an increase of ATT in females (r = 0.37, p < 0.001) but not in males (r = -0.1, n.s). Increases of 1° of MTS increased ATT 0.57mm in female patients (p < 0.001). MTS was influential in ATT despite the presence (r = 0.28 [0.11, 0.44], p = 0.001) or absence (r = 0.48 [0.35, 0.6], p < 0.001) of meniscal lesions. Greater medial tibial slope is associated with increased anterior tibial translation in females with ACL-deficient knees compared to males, despite the presence or absence of meniscal lesions. This could be due to a quadriceps/hamstring imbalance in females and the ability of the hamstring muscles to moderate ATT. III.

Anterior Cruciate Ligament, Acute Tears. Spontaneus Healing, is True or False

Objectives:To identify patients with a diagnosis of acute and complete ACL rupture that healed spontaneously, and to determine whether such healing is related to age, sex, type of rupture, resting time, and trauma mechanisms.Materials and Methods:30 patients with complete acute ACL rupture were evaluated by clinical diagnosis and Magnetic Resonance Image (MRI). Both Lysholm test and IKDC 2000 were used for subjective evaluation.Results:All patients improved from the first to the second consult, with the following results: Lachman (p <0.0406), pivot shift (p = 0.071), and anterior drawer (p <0.001). During the follow-up MRI, all patients showed signs of healing in ACL. With an average follow-up of 12 months for men (95% CI 6-17) and 13 months for women (95% CI 31 max.), a nearly complete clinical recovery could be inferred, as well as healing occurring independently of variables such as age, sex, or specific treatment (p = 0.795 and p = 0.841).Discussion:Despite this study size limitation, the objectives were achieved. There would be spontaneous ACL healing associated with a 3-month post-injury resting time, but it is unrelated to age, sex, specific physiotherapy treatments, or the use of immobilizers. Level of evidence: level of evidence IV

ACL injury incidence, severity and patterns in professional male soccer players in a Middle Eastern league

AimTo ascertain ACL injury incidence, severity (injury burden) and patterns (contact/non-contact and reinjuries) in a professional male football league in the Middle East over five consecutive seasons.MethodsProspective epidemiological study reporting...

A Tomahawk Shape of the Femur Predicts Greater Rotatory Knee Laxity in Patients with Anterior Cruciate Ligament Ruptures

Aims and Objectives: Interindividual variations in knee laxity are poorly understood. Utilizing novel pivot shift arthrometers and patients in our ACL registry the magnitude of the pivot shift was found to vary between 0-14 mm of anterior translation in the lateral compartment. Increased tibial slope was found to influence the magnitude of the pivot shift, however, it is unclear if femur morphology might influence the magnitude of the pivot shift. Therefore, the purpose of this study was to determine the relationship between anterior translation of the lateral compartment during a quantitative pivot shift test and the posterior femoral offset, quantified as the “tomahawk ratio”, in patients with complete ACL rupture. It was hypothesized that the “tomahawk ratio” would correlate with increased anterior translation of the lateral compartment of the knee. Materials and Methods: Consecutive patients with no history of prior knee surgeries undergoing primary ACL reconstruction were analyzed. A standardized pivot shift test was performed preoperatively under anesthesia on both knees and quantified using tablet technology as previously described. Radiographic measurements were made using standard lateral knee radiographs. The long axis of the femur shaft was determined by a line through the center of two circles centered on the femoral shaft. The axis of the femoral condyle was determined by a line between the most posterior and most anterior points of the lateral condyle. The distance from the intersection of these lines to the posterior end of the condyle was divided by the total anteroposterior length of the condyle. This ratio was defined as “tomahawk ratio”. Pearson correlation coefficient was used to analyze correlations (p- value < 0.05). Results: Data sets were successfully obtained for 32 female and 25 male patients. The mean anterior translation of the lateral compartment during the pivot shift test was found to be 3.96 ±2.38 mm and 1.27±0.89 mm for the involved and uninvolved knees, respectively, with a mean side-to-side difference of 2.70±2.25 mm. The mean length of the lateral femoral condyle on x-ray was 68.36±5.31 mm, and the mean tomahawk ratio was 63.16±4.53%. There was a significant correlation between the tomahawk ratio and the absolute quantitative (r = 0.370 p < 0.05) and side-to-side differences in anterior translation of the lateral compartment (r =0.419 p < 0.05). Conclusion: The main finding from this study is that ACL-deficient patients with larger posterior femoral offsets quantified as the “tomahawk ratio” were found to have higher lateral translations of the knee during the pivot shift test. This suggests that variation in knee instability may be significantly affected by femoral bony morphology characterized by a larger posterior portion of the lateral condyle. This study may assist clinicians in evaluating ACL injuries and identifying patients at greater risk for increased rotational knee instability.

English

Introduction: A 29-year old male athlete (body mass: 64 kg; height: 172 cm)sustained complete ACL rupture of the right knee. He was a martial-arts player and the injurywas repetitive, overuse in nature due to cyclic unilateral loading and unloading of the rightknee during training sessions. Rupture was diagnosed through detailed patient history, clinicalphysical examination and was confirmed through magnetic resonance imaging (MRI) of theright knee. Surgical reconstruction of the ACL was planned and a patellar tendon graft wasused. His baseline isokinetic data was recorded 4 months after the surgery. Objective: Thiscase study describes the effects of isokinetic strength training on knee biomechanics andphysical function of an ACL-reconstructed martial-arts athlete. Setting: Pakistan Sports BoardIslamabad. Study period: 40 days. Materials and Methods: Biodex System 3 Pro was used totrain the athlete for 15 sessions on alternate day basis. Average peak torque, average power,total work and peak torque to body weight ratio were recorded for hamstring and quadricepsbefore and after isokinetic rehabilitation. The athlete was positioned in the dynamometer withupright back while hip and knee were flexed to 90 degrees. Unilateral isokinetic contractionswere performed according to a premeditated exercise protocol. Both hamstring and quadricepswere tested isokinetically at five different movement speeds (30deg/sec, 90deg/sec, 150deg/sec, 210deg/sec, and 270deg/sec). Five contractions were performed at each speed duringboth knee flexion and extension. At baseline, average peak torque was higher at lower speedsfor both hamstring and quadriceps. Results: As a result of rehabilitation, average peak torquefor hamstring and quadriceps significantly improved at speeds of 150deg/sec and 90deg/secrespectively. Average power, peak torque to body weight ratio, total work was also improved forboth hamstring and quadriceps. Two physical performance tests - agility run test and verticaljump test - were used to assess the effects of training and both performance tests improved 51%and 100% respectively. Conclusion: Isokinetic training improved the strength of quadricepsand hamstring after ACL reconstruction. Hamstring muscle demonstrated greater traininginducedincrements in torque production compared to quadriceps at all contraction velocities.

KNEE BIOMECHANICS AND PHYSICAL PERFORMANCE;

Introduction: A 29-year old male athlete (body mass: 64 kg; height: 172 cm)sustained complete ACL rupture of the right knee. He was a martial-arts player and the injurywas repetitive, overuse in nature due to cyclic unilateral loading and unloading of the rightknee during training sessions. Rupture was diagnosed through detailed patient history, clinicalphysical examination and was confirmed through magnetic resonance imaging (MRI) of theright knee. Surgical reconstruction of the ACL was planned and a patellar tendon graft wasused. His baseline isokinetic data was recorded 4 months after the surgery. Objective: Thiscase study describes the effects of isokinetic strength training on knee biomechanics andphysical function of an ACL-reconstructed martial-arts athlete. Setting: Pakistan Sports BoardIslamabad. Study period: 40 days. Materials and Methods: Biodex System 3 Pro was used totrain the athlete for 15 sessions on alternate day basis. Average peak torque, average power,total work and peak torque to body weight ratio were recorded for hamstring and quadricepsbefore and after isokinetic rehabilitation. The athlete was positioned in the dynamometer withupright back while hip and knee were flexed to 90 degrees. Unilateral isokinetic contractionswere performed according to a premeditated exercise protocol. Both hamstring and quadricepswere tested isokinetically at five different movement speeds (30deg/sec, 90deg/sec, 150deg/sec, 210deg/sec, and 270deg/sec). Five contractions were performed at each speed duringboth knee flexion and extension. At baseline, average peak torque was higher at lower speedsfor both hamstring and quadriceps. Results: As a result of rehabilitation, average peak torquefor hamstring and quadriceps significantly improved at speeds of 150deg/sec and 90deg/secrespectively. Average power, peak torque to body weight ratio, total work was also improved forboth hamstring and quadriceps. Two physical performance tests - agility run test and verticaljump test - were used to assess the effects of training and both performance tests improved 51%and 100% respectively. Conclusion: Isokinetic training improved the strength of quadricepsand hamstring after ACL reconstruction. Hamstring muscle demonstrated greater traininginducedincrements in torque production compared to quadriceps at all contraction velocities.

Ocena wybranych parametrów chodu pacjentów przed- i 6 miesięcy po zabiegu wczesnej rekonstrukcji więzadła krzyżowego przedniego

[b]Background. [/b]ACL rupture and reconstruction may lead to impairment of spatiotemporal and kinematic gait parameters. The purpose of this study was to evaluate patient's gait following a complete tear of the ACL and its endoscopic reconstruction.[b]Material and methods.[/b] 3D gait analysis was performed using the BTS Smart optoelectronic system (6 IR cameras, 120 Hz). The study group included 40 patients with complete unilateral ACL rupture and 37 healthy matched subjects. In the study group gait analysis was performed twice, within one to two weeks prior to the ACL reconstruction and the follow-up study six months after surgery. In the control group single gait analysis was performed.[b]Results. [/b]Six months after the ACL reconstruction the duration of the stance phase for the non-operated limb (p&amp;amp;amp;lt;0,0000) and the initial double stance phase for the operated limb (p&amp;amp;amp;lt;0,0000) were reduced. A statistically significant increase in the step length for both lower limbs was observed. Additionally patients gait cadence (p=0,0003) and mean gait speed (p=0,0006) have also increased. Nevertheless, in the second study, these parameters were still significantly different comparing to the control group. Analysing the kinematic parameters of patients" gait after surgery it was demonstrated, that the hip and knee joints range of motion in both limbs has increased in a statistically significant way. The range of motion of the ankle joint of the operated limb has also improved.[b]Conclusions.[/b] 1. Within six months after the ACL reconstruction there was significant improvement and normalization of the patient's gait pattern, though we may still observe significant differences when compared to the control group, which indicates the need for further rehabilitation focused on the re-education of patients gait pattern. 2. Results of our study indicates a need of long-term observation in the group of patients after ACL reconstruction to determine, whether the gait pattern impairment demonstrate further tendency to improve in time.

Ramp lesions associated with ACL injuries are more likely to be present in contact injuries and complete ACL tears

The purpose of this study was to analyse patient and injury characteristics as well as arthroscopic findings in a prospective cohort of ACL-injured patients with or without an associated ramp lesion. Two hundred and twenty-four patients undergoing a primary (n=196) or revision (n=28) ACL reconstruction were included. The presence of a ramp lesion was determined by a systematic arthroscopic inspection of the posteromedial compartment. Chi-square tests were used to compare the population of ACL-injured patients with and without a ramp lesion regarding sex, age, body mass index, previous ACL injuries, sport before injury, and injury characteristics. Significance was set at p<0.05. Fifty-three out of 224 patients had a ramp lesion (24%). The presence of the latter was not related to any of the analysed patient characteristics. The prevalence of the lesion was higher in contact injuries (n=19; 41%) compared with non-contact injures (n=34; 19%; p<0.001). It was higher in patients with complete ACL ruptures (n=49; 27%) as opposed to partial ruptures (n=1; 4%; p=0.01). A patient was 2.98 [95% CI 1.49-5.98] times more likely to have a ramp lesion if the ACL injury was declared to have been caused by direct contact and 8.71 [95% CI 1.15-66.12] times more likely if the ACL tear was complete. Ramp lesions may be anticipated in almost one out of four patients undergoing ACL reconstruction, especially if a patient sustained a contact injury and in the presence of a complete ACL tear. III.

The difference in the pattern of joint damage in knee osteoarthritis in knees with partial and complete ACL ruptures

The difference in the pattern of joint damage in knee osteoarthritis in knees with partial and complete ACL ruptures

Increased Lateral Tibial Slope is a Risk Factor for Pediatric ACL Injury

Objectives:Recent research has asserted that increased posterior tibial slope measured on plain radiographs is associated with elevated risk of ACL rupture in adults. It is unclear, however, if tibial slope is also of significance in children and adolescents. The purpose of this case-control study was to 1) determine if alterations in posterior tibial slope are associated with ACL rupture in pediatric and adolescent athletes, and 2) to quantify changes in tibial slope by age.Methods:T2-weighted sagittal MRI scans of the knee were reviewed by three raters in a 1:1 sample of cases and controls, totaling 152 patients. Seventy-six skeletally immature patients with a complete non-contact ACL rupture were compared to an age- and gender-matched control group of 76 knees without ACL injury. The mean age of both groups was 14.8 +/- 1.3 years old and 46% of both groups were male. The medial and lateral compartments were each measured separately. All measurements were made using PACS software, employing a method similar to that which has been standardized in the adult literature. Our technique differed from previous studies in adults, though, in that the slope was measured on the cartilage surface, not the subchondral bone.Results:The mean posterior slope of the medial tibial plateau (MTS) was 5.4° ± 2.2° and 5.1° ± 2.3° (t-test; P=0.42) in the ACL-injured and control knees, respectively. The mean posterior slope of the lateral plateau (LTS) was 5.7° ± 2.4° in the ACL-injured knees and 3.4° ± 1.7° in the control knees (t-test; P<0.001) (Table 1). There was no difference in LTS between males and females (4.46° and 4.58°, P = 0.75). An interaction variable created by combining gender with LTS in a logistic regression model was not significant (P=0.12). Receiver operating characteristic (ROC) analysis of lateral tibial slope was used to determine a threshold value that might predict elevated risk of ACL injury. A cutoff of lateral posterior tibial slope >4° resulted in a sensitivity of 76% and a specificity of 75% for predicting ACL rupture in this cohort. Interrater reliability of tibial slope measurements was excellent (ICC=0.62 and 0.77 for the medial and lateral tibial plateaus, respectively). Spearman correlation analysis revealed that tibial slope decreased, or flattened, by 0.18° (P=0.028) and 0.21° (P=0.009) degrees per year as adolescents age.Conclusion:The biomechanical basis for an association between posterior tibial slope and ACL injury is well established in adults. To our knowledge, this is the first study that evaluates the association between tibial slope (as measured along the cartilage surface on MRI rather than subchondral bone on plain radiographs) and the risk of ACL rupture in a large adolescent cohort using a case-control design. Employing standard measurement techniques, the lateral tibial slope averaged 5.7° in ACL-injured knees and 3.4° in ACL-intact knees. A cutoff of >4° for the lateral posterior slope is 76% sensitive and 75% specific for predicting ACL rupture in this cohort of skeletally immature athletes. LTS did not influence the incidence of ACL injury differently between genders.

Do graft diameter or patient age influence the results of ACL reconstruction?

Hamstring tendons are commonly used as a graft source for ACL reconstruction. This study seeks to determine whether either the diameter of the tendon graft or the age of the patient influences the outcome of the ACL reconstruction when measured using a standard, previously validated laxity measurement device. This is a retrospective study of 88 patients who underwent ACL reconstruction with a short, quadrupled tendon technique, using the semitendinosus±gracilis tendons. Patients included in this study were sequential, unilateral, complete ACL ruptures. The patients were followed for a minimum of 1year postoperatively, with a mean follow-up of 26months. Patients were divided into three groups according to the diameter (Ø) of the graft: group 1 (32 patients): 8mm≤Ø≤9mm; group 2 (28 patients): 9mm<Ø≤10mm; and group 3 (28 patients): Ø>10mm. Three groups with differential laxity at 134N (Δ134=healthy side vs. operated side) measured with the laximeter GNRB(®) were compared. The risk of residual laxity (OR) between the three groups taking age, gender, BMI and meniscus status into account was calculated. A side-to-side laxity >3mm was considered as a residual laxity. The mean patient age at the time of reconstruction was 29.4years. The three groups were comparable. Postoperative Δ134 was 1.50±1.3, 1.59±1.5 and 2±1.7mm for groups 1 through 3, respectively. Δ134>3mm was observed in three patients in group 1, four patients in group 2 and nine patients in group 3. As compared to group 1, OR was 1.46 (95% CI 0.35-6.05) and 3.31 (95% CI 0.89-12.34) in groups 2 and 3, respectively. Adjustment for age, gender, BMI and meniscus did not change the estimates [OR 1.44 (95% CI 0.34-6.16) and 3.92 (95% CI 1-15.37)] in groups 2 and 3, respectively. Patients younger than 20 had a significantly higher average postoperative laximetry (2.4±1.5mm) compared to those aged 20years and over (1.5±1.5mm) (p=0.03), regardless of the diameter of the graft. The diameter of the graft between 8 and 10mm does not affect the laximetric results of an ACL reconstruction. Therefore, there does not appear to be a benefit to harvesting and adding further tissue to increase the diameter of the graft above 10mm. Patients younger than 20 represent a population at risk of graft elongation. In these patients at risk, postoperative management needs to be modified (delayed weight bearing, articulated splinting, slower rehabilitation) in the first months. Retrospective case series, Level IV.

Acute loading injuries and their relation to post-traumatic osteoarthritis in a preclinical model

Purpose: Up to 50% of knee injuries that result in tears of the ACL progress to post-traumatic OA (ptOA) within 10-15 years of the initial trauma. This represents an almost 5-fold increase in risk compared to non-injured joints, with current interventions (including surgical reconstruction) not significantly altering OA risk. Factors other than altered biomechanics may therefore play a significant role in disease development. Risk, rate of onset, and progression of ptOAmay be linked to the trauma's impact severity and the joint structures affected both acutely and chronically. A better understanding of the interaction of these variables may improve prognostic capability and enable the development of specific treatments for injury management and disease prevention. In the present study we investigated the relationships between age, gender, body mass, joint load, ACL rupture, and ptOA pathology using a murine model of non-surgical ACL rupture. Methods: ACL injury was induced by a single, axial compressive load to the flexed knee of themouse. At the peak load,10-15 seconds of sustained compression was applied before release. An initial cadaveric study assessed ACL failure loads over a range of mouse biometrics (9-52 week old, male and female C57BL-6, n1⁄4164). The failure load was determined from force-displacement curves and the mode of failure by microscopic evaluation. The potential predictors of these outcomes were assessed using mixed model linear regression and mixed model multinomial logistic regression. A subsequent in vivo study loaded the knees of anaesthetisedmice (10-12 week, male C57Bl-6) to either failure or 55% of the mean failure. Joint pathology was assessed histologically at 2 or 4 weeks post-injury (n1⁄47) in both the medial and lateral compartments. Results: In the cadaveric study, damage induced by loading was largely restricted to the ACL with little evidence of injury to other joint tissues. The ACL was consistently ruptured but the mode of failure varied between specimens. Ruptures occurred towards the femoral insertion with 16% of tears entirely midsubstance, 35% total avulsion fractures and 49% demonstrating a mixture of the two. Logistic regression determined that there was no effect of age, mass, rupture load or joint stiffness on the mode of failure. However, when comparing males and females with avulsion fractures, the relative risk for females was 7.11 (95% CI [1.36 37.07]). The ACL rupture load itself was demonstrated to have a positive association with mass (p < 0.001) but not age or gender when correcting for other covariates. In the in vivo study, complete ACL rupture resulted in significant femorotibial OApathology, particularly towards theposterior region and greatest in the medial compartment. At 2 weeks substantial synovitis, tibio-femoral cartilage erosion and structural damage to themedialmeniscuswere evident. By 4 weeks cartilage erosion progressed and subchondral bone sclerosis, osteophytes and enthesophytes developed. In contrast, subfailure loading of the knee resulted in only mild OA pathology. In these knees the ACL remained intact and there was no evidence of synovitis or osteophyte development. There was mild cartilage damage (unlike ACL failure this was similar in medial and lateral compartments) with significant progression from2 to 4weeks. Avery localised subchondral bone remodelling response was also evident posteriorly in the tibia. Conclusions: In this model ACL failure loads have been established for a range of mouse biometrics and were shown to be independent of the age and sex of the mouse. In vivo, complete ACL failure results in the rapid onset of pathology with a clinically relevant pattern of OA change in all other joint tissues. At the early time points examined in this study, mechanical loading alone (no ACL rupture) induces mild changes largely restricted to the cartilage, although this may progress further given more time. Comparisons with other loading regimes and surgical models of ptOA may further illuminate the complex interactions that occur between different joint tissues and risk factors for ptOA.

CORR Insights®: How Useful is MRI in Diagnosing Isolated Bundle ACL Injuries?

Where Are We Now? We now know that the ACL has at least two distinct bundles: anteromedial and posterolateral. Because of this, anatomic two-bundle ACL reconstruction techniques have become an established option [3]. Taking this a step further, some authors have identified partial ACL disruptions (a tear to one of two bundles), and have promoted isolated bundle reconstructions — reconstructing only the torn bundle, leaving alone the bundle that is apparently uninjured. This kind of ACL-remnant preservation with isolated bundle reconstruction is gaining recognition in the orthopaedic community. In fact, several authors have demonstrated clinical outcomes equal to those of standard ACL reconstruction with the use of remnant preservation/isolated bundle reconstructions [1, 2, 6]. Identifying these isolated/partial ACL tears can be difficult, not only on clinical examination, but also by MRI. Recently, Van Dyck et al. [5] demonstrated that the accuracy of MRI for the diagnosis of partial ACL tears was 25% to 53%, with only moderate interobserver agreement. The authors found that the partial tears demonstrated MRI features that are indistinguishable from complete ACL tears, mucoid ACL degeneration, and the normal ACL. Additionally, Dejour et al. [4] confirmed these findings by indicating that, in partial tears, there was no correlation between preoperative MRI findings and arthroscopically confirmed type of ACL tear. Partial ACL disruption, compared with complete ACL disruption, is extremely rare. In the Van Dyck study, researchers diagnosed partial ACL disruption on MRI in only 6% of their patient cohort. Where Do We Need to Go? In the current study by Chang et al., the authors sought to determine: (1) the proportion of knees with an intact anteromedial or posterolateral bundle in patients undergoing ACL reconstruction; (2) whether MRI predicted the bundle conditions seen at the time of surgery; and (3) whether the accuracy of the MRI prediction was affected by the timing of MRI after injury. Similar to the Van Dyck series, the authors found only 7% of the patients at the time of arthroscopy had an intact isolated anteromedial or posterolateral bundle. Unlike the Van Dyck series, Chang and authors found an overall diagnostic accuracy of MRI to be 83% for predicting isolated bundle tear. Lastly, an MRI performed earlier than 6 weeks from the time of injury was less accurate compared with an MRI performed later than 6 weeks. The authors concluded that MRI “can help surgeons predict bundle injury pattern with satisfactory precision.” There is no question that if we are going to treat these injuries effectively, it is important that we be able to diagnose them accurately. The other issue — perhaps the greater of the two — is how to correlate each injury (whether a partial, one-bundle injury, or a complete ACL rupture) with its physical findings, and interpret these findings in the context of each patient’s needs. How Do We Get There? Although MRI is helpful, clinical examination and assessment of the functional needs of the patient ultimately guides treatment in patients considering ACL reconstruction. Therefore, an ideal study examining the efficacy of MRI in diagnosing isolated ACL injuries would compare preoperative physical exam findings with MRI detection of isolated bundle tears, correlating the results to arthroscopic findings. A study of this magnitude could lead to alterations in surgical decision making. In other words, the decision to perform an ACL reconstruction depends on many factors, including patient age, activity level, concomitant meniscal and cartilage lesions, patient goals, and expectations of the patient, just to name a few. Ideally, if we could predict preoperatively, based on MRI and physical exam findings, which patients would benefit from isolated bundle reconstructions, then the use of MRI to predict isolated bundle tears would be helpful. If the decision to perform isolated bundle reconstruction is made solely at the time of ACL surgery, then the use of MRI to detect isolated tears preoperatively becomes less clinically relevant.

Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of physical examinations with and without anaesthesia

The aims of this meta-analysis were to determine the sensitivity and specificity of the Lachman, pivot shift and anterior drawer test for acute complete ACL rupture in the office setting and under anaesthesia. It was hypothesized that the Lachman test is the most sensitive and the pivot shift test the most specific. Secondly, it was hypothesized that the sensitivity and specificity of all three exams increases when the examination is performed under anaesthesia. An electronic database search was performed using MEDLINE and EMBASE. All cross-sectional and cohort studies comparing one or more physical examination tests for diagnosing acute complete ACL rupture to an accepted reference standard such as arthroscopy, arthrotomy and MRI were included. Twenty studies were identified and included. The overall sensitivity of the Lachman test was 0.81 and the specificity 0.81; with anaesthesia, the sensitivity was 0.91 and the specificity 0.78. For the anterior drawer test, the sensitivity was 0.38 and the specificity 0.81; with anaesthesia, the sensitivity was 0.63 and the specificity 0.91. The sensitivity of the pivot shift test was 0.28 and the specificity 0.81; with anaesthesia, the sensitivity was 0.73 and the specificity 0.98. In the office setting, the Lachman test has the highest sensitivity for diagnosing an acute, complete ACL rupture, while all three tests had comparable specificity. When the examination was performed under anaesthesia, the Lachman test still obtained the highest sensitivity, but the pivot shift test was the most specific. Meta-analysis of diagnostic test accuracy, Level II.

Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of instrumented knee laxity tests

The aims of this meta-analysis were to determine the sensitivity and specificity of the KT 1000 Arthrometer, Stryker Knee Laxity Tester and Genucom Knee Analysis System for ACL rupture. It was hypothesized that the KT 1000 test is the most sensitive and specific. Secondly, it was hypothesized that the sensitivity and specificity of the KT 1000 arthrometer increase when the amount of Newton force is increased. An electronic database search was performed using MEDLINE and EMBASE. All cross-sectional and cohort studies comparing one or more instrumented examination tests for diagnosing acute complete ACL rupture in living human subjects to an accepted reference standard such as arthroscopy, arthrotomy and MRI were included. The sensitivity of the KT 1000 Arthrometer with 69 N was 0.54. With 89 N, the sensitivity was 0.78 and the specificity 0.92, and with maximum manual force, the sensitivity was 0.93 and the specificity 0.93. For the Stryker Knee Laxity Tester, the sensitivity was 0.82 and the specificity 0.90. And for the Genucom Knee Analysis System, the sensitivity was 0.74 and the specificity 0.82. The KT Arthrometer performed with maximum manual force has the highest sensitivity, specificity, accuracy and positive predictive value for diagnosing ACL rupture. Meta-analysis, level I.

Arthroscopy

In this issue of Clinical Orthopedics and Related Research, we present papers related to the indications and benefits of minimally invasive or endoscopic surgery for treating athletic injuries in different joints. These papers were selected from those presented at the 11th Biannual Meeting of the Argentina Arthroscopy Association held in Buenos Aires, Argentina, in May 2010. This meeting was organized in conjunction with the XIII Annual Meeting of the Argentina Association of Sports Trauma and the IV Annual Meeting of the Latin America Society of Arthroscopy, Knee Surgery, and Sport Medicine. The American Orthopaedic Society for Sports Medicine participated as the guest society. The forum provided a unique opportunity for members of these societies to share scientific information in an intimate setting. Three of the eight articles address the ongoing difficulty in diagnosing and treating recurrent anterior shoulder instability. The first study explored the relationship between generalized joint laxity and the potential increased risk of recurrent shoulder instability, as has been suggested in the literature. However, there are conflicting data on the association between generalized joint laxity and traumatic recurrent shoulder instability. Although these findings are not definitive, they add to the body of literature suggesting generalized joint laxity does not predispose to recurrent shoulder instability. The second study compared the frequency of lesions associated with traumatic anterior instability in patients with primary and recurred instability. Associate injuries are more common in shoulders with recurrent dislocations, suggesting delay of the reconstruction may increase these secondary morbidities. The third study analyzed a group of patients with revision surgery of a previous arthroscopic instability repair. In this situation, the surgeon is faced with the following dilemma: to perform either an open repair technique in an attempt to minimize the chance of recurrence or an arthroscopic repair aiming to minimize soft tissue damage and enable the patient to regain as much function as possible. The authors suggested the recurrence rate after revision arthroscopic and open instability repairs would be similar in the absence of glenoid or humeral bone loss and if the patient was willing to avoid contact sports. Another paper evaluated patients with irreparable tears of the scapholunate interosseous ligament area, which is a common cause of mechanical wrist pain. The authors determined whether arthroscopic reduction is feasible, controls pain, and improves wrist function while preserving ROM. Although arthroscopic reduction is a minimally invasive alternative to the open procedure, its effectiveness in controlling pain and preserving wrist function has not been established. Three articles analyzed novel events or therapies for ACL ruptures, knee instability, or chronic patellar tendinopathy. The first paper reported a clinical and MRI study of patients with spontaneous healing in complete ACL ruptures and determined whether patients were able to return to athletic activity. Although most orthopaedists believe the ACL does not spontaneously heal after a complete rupture, the authors’ observations indicate the injured ACL may eventually spontaneously heal without using an extension brace, allowing return to athletic activity. The second study described a series of patients with rotatory knee instability associated with depressions of the lateral tibial plateau despite an intact arcuate ligament complex. The authors found correcting the bone deformity with an open-wedge osteotomy of the lateral tibia plateau and elevating the depressed bone could restore knee stability. The third paper explored whether an arthroscopically assisted approach to débride not only the tendon and bone but also the peritenon could relieve pain from patellar tendinopathy and allow athletes to return to their former activities. Another paper compared percutaneous repair versus open repair in acute Achilles tendon rupture in terms of function, cosmesis, and complications. I would like to thank all of the authors for their hard work in presenting their observations and data on minimally invasive surgery for various sports-related problems (Fig. 1).Fig. 1: Dr. Miguel A. Ayerza is shown.