Probabilistic timed Petri nets for clinical pathway design and analysis: a case study

An increased posterior tibial slope (PTS) has been shown to be a risk factor for anterior cruciate ligament (ACL) ruptures, but the difference in the mean PTS between patients with ACL ruptures and patients with intact ACLs is only approximately 1°, and the PTS has a wide range between 1° and 22°. Therefore, an ACL rupture may be associated with other morphological differences along with the PTS. To evaluate whether the predictive value of the PTS can be increased with new parameters associated with the proximal tibia, distal femur, and extensor mechanism. Cross-sectional study; Level of evidence, 3. This study included 81 patients who underwent surgical treatment for isolated ACL ruptures and 81 patients with intact ACLs as the control group.Lateral PTS (LPTS), medial PTS (MPTS), lateral femoral condylar offset, anterior patellar offset (APO), lateral tibial plateau offset, and tibial tubercle offset were measured on magnetic resonance imaging. The patella-lateral tibial plateau ratio (P-LTPR) was obtained by dividing the APO by the lateral tibial plateau offset, and the patella-tibial tubercle ratio (P-TTR) was obtained by dividing the APO by the tibial tubercle offset. Patients with ACL ruptures and intact ACLs were subdivided according to an LPTS ≥8° and an LPTS <8° and compared. The parameters independently associated with ACL ruptures were P-LTPR (P = .001), P-TTR (P = .006), LPTS (P = .016), and MPTS (P = .047). In patients with intact ACLs and an LPTS ≥8°, P-LTPR was negatively correlated with LPTS and MPTS (P = .015 and P < .001, respectively; r = -0.736 and r = -0.758, respectively). In patients with an LPTS ≥8°, P-LTPR was associated with ACL ruptures, with 77.8% sensitivity and 73.7% specificity, at values >1.38, while P-TTR was associated with ACL ruptures, with 68.3% sensitivity and 67.7% specificity, at values >1.77. In patients with an LPTS <8°, P-TTR was associated with ACL ruptures, with 68.7% sensitivity and 77.2% specificity, at values >1.86. An evaluation of the P-LTPR and P-TTR parameters when assessing anatomic risk factors for an ACL rupture may increase the predictive information provided by the PTS. P-LTPR may be especially useful in re-evaluating the risk of ACL ruptures in patients who are considered to have a high risk because of a high PTS but an intact ACL, and P-TTR may be useful in re-evaluating the risk of ACL ruptures in patients who are considered to have a low risk because of a low PTS.

BackgroundStudies have shown that the spherical shape of the lateral femoral condyle has a clear relationship with the relative axial movement of tibiofemoral joint and the anterior cruciate ligament (ACL) rupture. The purpose of this study was to describe the distal curvature of the lateral femoral condyle by ratio of height of lateral femoral condyle to anteroposterior diameter (HAPR), and evaluate its correlation with ACL rupture.MethodsA retrospective case-control study of 64 patients was conducted. Two age-and sex-matched cohorts (each n = 32) were analyzed: primary ACL ruptures, and a control group consisting of isolated meniscal tears. On the radiograph, the distance from the intersection of the axis of the distal femur and the anteriorly diameter of the lateral femoral condyle to the lower point of the lateral femoral condyle divided by the anteriorly diameter of the lateral femoral condyle is HAPR. The HAPR was measured by digital radiograph imaging systems (DR) to quantify femoral sphericity. Cutoff values were defined; and diagnostic performance of the risk factors was assessed. Meanwhile, we measured the posterior tibial slope (PTS) on radiograph and compared the two methods to evaluate the significance of HAPR in predicting ACL rupture.ResultsA total of sixty-four patients who met the inclusion criteria were included in the final analysis (32 with primary ACL rupture, 32 controls). The HAPR was smaller in the knees with primary ACL rupture (0.31 ± 0.02) than that of the control group (0.33 ± 0.02) (p < 0.01). The PTS was bigger in the knees with primary ACL rupture (8.18 ± 2.77) than that of the control group (6.61 ± 2.85) (p = 0.036). The AUC of HAPR was bigger (0.825; 95% CI, 0.72–0.93) than that of PTS (0.675; 95%CI, 0.85–0.81). The calculated cutoff of HAPR of 0.32 (Youden index, 0.56) was associated with an increased risk for ACL rupture, with sensitivity of 75% and specificity of 81% to predict an ACL rupture.ConclusionsThis study showed that a decreased HAPR is associated with an ACL rupture, and the decrease of HAPR was more significant in predicting ACL ruptures than the PTS. This helps clinicians identify susceptible individuals who may benefit from targeted ACL rupture prevention counseling and intervention.

Gene expression profiling of normal and ruptured canine anterior cruciate ligaments

Recent studies have shown that several genetic factors can cause susceptibility to anterior cruciate ligament (ACL) rupture. The aim of the present study was to evaluate certain underlying factors that increase the risk of ACL rupture. Eight hundred thirty-six patients with ACL rupture who underwent ACL reconstructive surgery from 2010 to 2013 at an academic center completed a minimum of 5years post-operation follow-up. The collected variables included sex, age, height, weight, exercise level, time interval between ACL rupture in the first knee and contralateral ACL rupture, dominant leg, side of the involved knee and sibling history of ACL rupture. The median follow-up duration was 6.5 (range: 5-8) years. Eighty-three patients (9.9%) had a contralateral ACL rupture, and 155 patients (18.5%) had siblings with a history of ACL rupture. The rate of contralateral ACL rupture was three times higher in women than in men and in patients with siblings with a history of ACL rupture than in those without such history. In addition, the risk of contralateral ACL rupture was higher in those younger than 30years of age, those with a BMI of 20-25kg/m2 and those who participated in regular sports activity. However, whether the involved knee was on the dominant or nondominant side had no effect on the incidence of contralateral ACL rupture. The results of the study showed that 69 (83.1%) of the contralateral ACL ruptures occurred within the first 2years after the primary operation. In a 5- to 8-year follow-up, one out of every ten patients had a contralateral ACL rupture, and two out of every ten patients had siblings with a history of ACL rupture. The findings suggest that having a sibling with a history of ACL rupture and being female are important risk factors for ACL rupture of the contralateral knee. III.

To evaluate, using magnetic resonance imaging (MRI), the prevalence of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) rupture in knees with symptomatic osteoarthritis (OA) compared with those without OA, and the relationship to pain and recalled injury. MRI and plain radiography of the knee were performed in a group of 360 subjects with painful knee OA (cases; 66.7% male, mean age 67.1 years) and 73 without knee pain (controls; 57.5% male, mean age 66.1 years). MRIs were read for the presence or absence of complete or partial ACL or PCL tear. Subjects with knee pain were asked to quantify severity of pain on a visual analog scale and to report whether they could recall a significant knee injury (requiring use of a cane or crutches). We compared the prevalence of ACL and PCL rupture in those with and those without knee pain and also evaluated whether, in cases, there was any association with recalled knee injury. The proportion of cases who had complete ACL rupture was 22.8%, compared with 2.7% of controls (P = 0.0004). PCL rupture was rare both in cases (0.6%) and in controls (0%). Cases with ACL rupture had more severe radiologic OA (P < 0.0001) and were more likely to have medial joint space narrowing (P < 0.0001) than cases with intact ACLs, but did not have higher pain scores. Among cases, only 47.9% of those with complete ACL tears reported a previous knee injury, compared with 25.9% of those without complete ACL tears (P = 0.003). ACL rupture is more common among those with symptomatic knee OA compared with those without knee OA. Fewer than half of subjects with ACL rupture recall a knee injury, suggesting that this risk factor for knee OA is underrecognized.

BackgroundThe literature does not clearly convey the relationship between eminential morphometry and non-contact anterior cruciate ligament (ACL) ruptures. This study attempts to reveal whether there is a relationship between non-contact ACL ruptures and eminential morphometry.MethodsKnee magnetic resonance images (MRIs) taken for the various indications between January 2022 and June 2023 were retrospectively scanned. The patients were categorized into 2 groups: those with an ACL rupture and those with an intact ACL. For each patient, eminential angle 1, eminential angle 2, medial eminential height, lateral eminential height, total eminential height, eminential width, and the ratio of tibial plateau width and eminential width to the tibial plateau width were measured by 2 different orthopedists. Patients whose MRIs were used for measurement were evaluated and grouped according to their age, sex, and injury side.ResultsIn total, 400 MRIs of 400 patients were included in the study. While 200 patients had an ACL rupture, 200 had an intact ACL. The total eminential height in the ACL rupture group was measured at 16.1 ± 2.6 mm and 15.5 ± 2.7 mm (p = 0.035) in the ACL intact group. Eminental width in the ACL rupture group was measured at 12.1 ± 1.9 mm and 13.0 ± 2.0 mm in the ACL intact group (p = 0.0001). The tibial plateau width was 75.4 ± 15.7 mm in the ACL rupture group and 73.6 ± 5.8 mm in the ACL intact group (p = 0.002). According to the logistic regression analysis, the p-value for males was 0.0001, and for eminential width, the p-value was 0.0001.ConclusionsA significant difference was found between the ACL rupture and the ACL intact groups regarding eminential height, eminential width, and tibial plateau width parameters. Being male and having a low eminential width were identified as independent risk factors for non-contact ACL.Trial registrationNot applicable.

To examine the rate of (1) second anterior cruciate ligament (ACL) rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone in patients with generalized joint hypermobility (GJH) at 12 months, at 24 months, and at the longest available time (LAT) following return to sport (RTS) after ACL reconstruction depending on graft choice, that is, hamstring tendon (HT) autograft or bone-patellar tendon-bone (BPTB) autograft. Data were extracted from a rehabilitation registry that comprised patients who had undergone ACL reconstruction between 2014 and 2022. Patients with GJH aged between 16 and 50 years who had minimum 24-month follow-up following RTS after ACL reconstruction with HT autograft (GJH-HT) or BPTB autograft (GJH-BPTB) were included. A Cox proportional hazard regression model was used to examine the rate of (1) second ACL rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone at 12 months, at 24 months, and at the LAT after RTS. This study included 82 patients (54 in the GJH-HT group and 28 in the GJH-BPTB group), of whom 72.0% were female patients, and the average age was 22.7 ± 7.4 years. The proportion of second ACL ruptures was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (11 of 54 [20.4%] vs 0 of 28 [0%], P = .013), at 24 months (13 of 54 [24.1%] vs 1 of 28 [3.6%], P = .028), and at the LAT (16 of 54 [29.6%] vs 2 of 28 [7.1%], P = .024) after RTS. The rate of second ACL rupture was greater in the GJH-HT group than in the GJH-BPTB (hazard ratio = 4.98, P = .032) at the LAT after RTS. The proportion of patients with graft rupture was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (8 of 54 [14.8%] vs 0 of 28 [0%], P = .046), at 24 months (10 of 54 [18.5%] vs 0 of 28 [0%], P = .013), and at the LAT (12 of 54 [22.2%] vs 0 of 28 [0%], P = .006) after RTS. An over 4 times greater rate of second ACL rupture after RTS was reported for patients with GJH who underwent ACL reconstruction with HT autograft compared with BPTB autograft. Patients with GJH who were treated with BPTB autograft for ACL reconstruction did not experience graft rupture after RTS. Level III, retrospective study.

Background:Lower limb valgus alignment has previously been identified in pediatric patients with anterior cruciate ligament (ACL) rupture. This study aimed to evaluate knee morphology on magnetic resonance imaging (MRI) in valgus and non-valgus aligned pediatric patients with ACL rupture and compare them against a typically developed (TD) cohort without ACL rupture.Hypothesis:There would be differences in knee morphology between valgus and non-valgus aligned pediatric patients with ACL rupture and a TD cohort.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Data were extracted from the Queensland Children's Hospital prospective pediatric ACL Injury Registry. Preoperative MRI of patients with ACL rupture was compared against an age- and sex-matched TD cohort without knee pathology. The following morphological parameters were measured: lateral femoral condyle index (LFCI), lateral tibial height, medial posterior slope, lateral posterior slope (LTS), medial tibial depth, and notch width index. The mechanical axis deviation (MAD) was measured from preoperative long-leg radiographs. One-way analysis of covariance with the Tukey post-hoc test compared parameters in valgus (MAD <1 mm medial), non-valgus (MAD ≥1 mm medial), and TD groups, adjusting for age and sex. Mean differences were reported with 95% CIs.Results:A total of 150 patients with ACL rupture were eligible. After propensity score matching against the TD cohort (n = 26), the ACL rupture group (valgus, n = 26; non-valgus, n = 26) had similar baseline characteristics: combined mean age (13.97 ± 2.20 years) and sex (57.69% women vs 42.31% men). Compared with the TD cohort, valgus ACL-ruptured patients had significantly smaller LFCI (–0.16 [95% CI, –0.20 to −0.11]) and larger LTS (2.53 [95% CI, 0.50 to 4.56]) values. Valgus-aligned patients with ACL rupture had smaller LFCIs compared with non-valgus-aligned patients with ACL rupture (–0.12 [95% CI, 0.17 to −0.08]).Conclusion:Compared with a TD cohort, morphological variations were found within subsets of pediatric patients with ACL rupture when accounting for lower limb alignment. Valgus-aligned patients had smaller LFCI and steeper LTS values than the TD cohort.

Right and left knee laxity measurements: a prospective study of patients with anterior cruciate ligament injuries and normal control subjects.

Knee Injury and Osteoarthritis Outcome Score or International Knee Documentation Committee Subjective Knee Form: Which Questionnaire Is Most Useful to Monitor Patients With an Anterior Cruciate Ligament Rupture in the Short Term?

BackgroundAnterior cruciate ligament plays a significant role in knee joint stability. It is claimed that the incidence of knee osteoarthritis increases in individuals with anterior cruciate ligament (ACL) rupture. The aim of this study was to evaluate the knee joints reaction force in ACL rupture group compared to normal subjects.MethodFifteen patients with acute ACL rupture and 15 healthy subjects participated in this study. The ground reaction force (GRF) and kinematic data were collected at a sampling rate of 120 Hz during level-ground walking. Spatiotemporal parameters, joint angles, muscle forces and moments, and joint reaction force (JRF) of lower extremity were analyzed by OpenSIM software.ResultsThe hip, knee and ankle joints reaction force at loading response and push-off intervals of the stance phase during walking was significantly higher in individuals with ACL rupture compared to healthy controls (p value < 0.05). Walking velocity (p value < 0.001), knee (p value = 0.065) and ankle (p value = 0.001) range of motion in the sagittal plane were significantly lower in the patients with ACL rupture compared to healthy subjects. The mean value of vertical GRF in the mid-stance, the peak of the hip adduction moment in loading response and push-off phases, the hip abductor, knee flexor and vastus intermedius part of quadriceps muscle forces were significantly higher compared to healthy subjects (p < 0.05) while vastus medialis and vastus lateralis produced significantly lower force (p < 0.001).ConclusionsBased on results of this study, lower limb JRF was higher in those with ACL rupture compared to healthy subjects may be due to the compensatory mechanisms used by this group of subjects. An increase in knee JRF in patients with ACL rupture may be the reason for the high incidence of knee OA.

Is an excessively high posterior tibial slope a predisposition to knee injuries in children? Systematic review of the literature

Background: Although the femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, the recommendations for the ideal femoral footprint position are mostly based on cadaveric studies with small sample sizes, elderly patients with unknown ACL status, and 2-dimensional techniques. Furthermore, a potential difference in the femoral ACL footprint position and ACL orientation between ACL-ruptured and ACL-intact knees has not been reported in the literature. Hypothesis: The femoral ACL footprint position and ACL orientation vary significantly between ACL-ruptured and matched control ACL-intact knees. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance images of the knees of 90 patients with an ACL rupture and 90 matched control participants who had a noncontact knee injury without an ACL rupture were used to create 3-dimensional models of the femur and tibia. The ACL footprints were outlined on each model, and their positions (normalized to the lateral condyle width) as well as ACL orientations were measured with an anatomic coordinate system. Results: The femoral ACL footprint in patients with an ACL rupture was located at 36.6% posterior and 11.2% distal to the flexion-extension axis (FEA). The ACL orientation was 46.9° in the sagittal plane, 70.3° in the coronal plane, and 20.8° in the transverse plane. The ACL-ruptured group demonstrated a femoral ACL footprint position that was 11.0% more posterior and 7.7% more proximal than that of the control group (all P < .01). The same patients also exhibited 5.7° lower sagittal elevation, 3.1° higher coronal plane elevation, and 7.9° lower transverse plane deviation (all P < .01). The optimal cutoff value of the femoral ACL footprint position to prevent an ACL rupture was at 30% posterior and 12% distal to the FEA. Conclusion: The ACL femoral footprint position might be a predisposing factor to an ACL rupture. Patients with a >30% posterior and <12% distal position of the femoral ACL footprint from the FEA might have a 51.2-times increased risk of an ACL rupture.

Reconstruction of the anterior cruciate ligament (ACL) is a common surgical procedure with an estimated 50,000 procedures in the US annually. Injury of the ACL often requires costly treatment, extensive rehabilitation, and results in early osteoarthritis. While ACL ruptures occur secondary to a complex interplay of multiple variables, a number of risk factors have been identified that increase risk of ACL rupture. We will analyze a variety of identified risk factors including anatomic, neuromuscular control, hormonal, genetic, and external variables. In terms of intrinsic risk factors, multiple recent studies have identified neuromuscular risk factors that put the ACL at risk for injury. These studies show differences in neuromuscular control of knee joint mechanics, hamstring muscle strength and core stability in patients who sustain ACL injury. Anatomical variants between individuals, genders and races have also been implicated as risk factors for ACL injury. These risk factors include femoral intercondylar notch width, tibial slope geometry, ACL dimensions, and generalized ligamentous laxity. Studies have sought to evaluate the interactions between absolute femoral notch width, notch width index, and intercondylar notch shape and how these factors relate to ACL injury risk. Postulating that an increased anterior directed shear force on the tibia correlates with higher incidence of ACL injury, studies have identified an increased posterior inferior directed tibial slope and shallow medial depth of the tibial plateau, as significant risk factors for ACL injury. Newer research suggests that meniscal geometry factors into this equation as well. Other studies have suggested that decreased ACL volume is a contributing factor, while further studies propose that ACL injury risk can be predicted as a factor of generalized joint laxity. Lastly, prior ACL injury and reconstruction have been implicated as risk factors for future knee injury. Patients undergoing ACL reconstruction are at higher risk for contralateral ACL injury and ACL rerupture post reconstruction compared to individuals without prior ACL injury. Additionally, hormonal and genetic factors have been connected to ACL injury. After estrogen and progesterone receptor sites were found on the ACL, multiple studies have analyzed hormone levels and ACL rupture risk. Overall, the results of these studies are varied and controversial, but suggest an increased risk in the pre ovulatory menstrual cycle phase. Genetic studies have shown specific mutations that place patients at risk for ACL injury and other tendon injury. Also, a study has shown that patients with an ACL rupture were more than 4 times as likely to have a relative with history of ligament injury.

OBJECTIVE To measure the electroencephalography (EEG) of the patients with anterior cruciate ligament (ACL) rupture when performing joint position perception movement task, to compare the differences between the ACL rupture side and the unaffected side, to identify the EEG change in the power spectrum caused by the ACL rupture, and to provide evidence for the diagnosis, treatment and rehabi-litation for ACL injury as well as knee instability. METHODS Sixteen male patients, selected from the Department of Sports Medicine, Peking University Third Hospital from November 2014 to April 2015, with only ACL rupture on one side used isokinetic muscle strength testing equipment were enrolled in the study to perform unilateral active knee joint positional movement and passive knee joint positional movement tasks. EEG was recorded to compare between the affected and unaffected limb of ACL rupture patients when doing single leg movement tasks, including passive knee joint position test and active knee joint position sensation test. The target position of the active knee joint position movement task and the passive knee joint position movement task was 30 degrees of knee flexion. RESULTS During the passive knee joint position test, there was no significant difference in EEG power spectrum of Delta[F (1, 15)=0.003, P=0.957, ηP2 =0.001], Theta[F (1, 15)=0.002, P=0.962, ηP2 < 0.001], Alpha[F (1, 15)=0.002, P=0.966, ηP2 =0.001], Beta[F (1, 15)=0.008, P=0.929, ηP2 =0.001] at Fz, Cz, and Pz between the affected and unaffected limbs in the ACL patients. During the active knee joint position movement task, the EEG power spectrum of Delta, Theta, Alpha, Beta at Fz and Cz location, on the affected side was significant higher than on the unaffected side. CONCLUSION This study compared the differences between the ACL rupture side and the unaffected side during active knee position movement task and passive knee position movement task, and identifyied the EEG changes in the power spectrum caused by the ACL rupture, It was found that the central changes caused by unilateral ACL rupture still existed during contralateral (unaffected) side movement. The EEG power spectrum of the affected side during active exercise was significantly higher than that of the unaffected side This study provides new electrophysiological evidence for the study of ACL injury.