Lateral Posterior Tibial Slope Research Articles

Ipsilateral ACL injured patients with Segond fractures demonstrate increased posterior tibial slope

BackgroundThe anterolateral complex has been demonstrated to assist with rotational stability and prevention of anterior tibial translation during the pivot shift. In this study the Segond fracture is used as a surrogate for an anterolateral complex injury to determine if there is an association between Segond fracture and increased posterior tibial slope. MethodsPatients’ charts and radiographs were analyzed retrospectively for the presence of Segond fractures on injury radiographs. These patients, the Segond cohort, were then age and gender matched to a control cohort. Demographic as well MRI measurements of medial and lateral posterior tibial slope and lateral-to-medial slope asymmetry were collected for each cohort. Secondary outcome of anterior cruciate ligament reconstruction failure data was also collected. ResultsThe Segond group demonstrated a statistically significantly greater lateral posterior tibial slope (8.42° versus 6.55°, P = 0.003) as well as medial posterior tibial slope (6.57° versus 5.34° degrees, P = 0.045). There was no significant differences between lateral-to-medial asymmetry (2.18°versus 1.83°, P = 0.246). ConclusionPatients with Segond fractures at the time of anterior cruciate ligament injury have increased medial and lateral posterior tibial slope. This may relate to increased rotational and translational instability associated with anterolateral complex injuries. Surgeons treating these patient may use this information to counsel their patients on the risks of associated pathology at the time of arthroscopy such as lateral meniscal posterior root tears.

Decreased lateral posterior tibial slope and medial tibial depth are underlying anatomic risk factors for posterior cruciate ligament injury: a case–control study

ObjectivesTo research whether medial PTS, lateral PTS and MTD were different between the PCL injury group and the PCL intact group.DesignRetrospective case–control study, level of evidence III.MethodsFifty patients with PCL rupture from 2015 to 2020 in our hospital, and 50 patients matched by age and sex with intact PCL were enrolled in our study. The intraclass correlation coefficient (ICC) was used to assess the reliability of each parameter. The independent t-test was conducted to identify the differences in tibial morphometric characteristics between the PCL-injured and PCL-intact individuals, including the posterior tibial slope (PTS), meniscal slope (MS), medial tibial depth (MTD). A binary logistic regression model was established to evaluate the roles of those anatomic parameters of interest play in PCL injuries.ResultsThe interobserver reliability of each parameter showed excellent agreement. Significant differences in the medial (P = .023) and lateral (P = .009) PTS were found between the PCL-injured group (3.68 ± 2.70 and 4.55 ± 3.19, respectively) and the controls (5.00 ± 2.73 and 6.39 ± 3.29, respectively). And the MTD was 1.98 ± 0.64 mm in the PCL-injured group and 2.37 ± 0.55 mm in the control group (P = 0.007). Binary logistic regression analysis showed that smaller lateral PTS and MTD were directly associated with PCL injury, with an OR of 1.17 and OR of 3.14, respectively. The medial PTS was independent to PCL injures.ConclusionDecreased lateral PTS and MTD were underlying anatomic risk factors for PCL injury.

Differentiation in Posterior Tibial Slope by Sex, Age, and Race: A Cadaveric Study Utilizing 3-Dimensional Computerized Tomography

Background: Posterior tibial slope (PTS) has recently gained increased attention for its possible role in anterior cruciate ligament and posterior cruciate ligament injury. The possible differences among age, sex, and ethnicity in PTS have not yet been reported. Purpose: To describe demographic variances of proximal tibial anatomy and to detect differences in regard to ethnicity, sex, and age. Study Design: Cross-sectional study; Level of evidence, 3. Methods: In total, 250 cadaveric specimens with full-body computerized tomography scans from the New Mexico Descendant Imaging Database were randomly selected (inclusion/exclusion criteria: older than 18 years, complete imaging of the knee without previous surgery or arthroplasty) and reviewed by 3 independent observers measuring medial posterior tibial slope (MPTS), lateral posterior tibial slope (LPTS), and global posterior tibial slope (PTS), which was calculated as the mean of the MPTS and LPTS. Individuals were evenly divided among male and female and ethnicities/races: African American/Black, Asian American, Hispanic, Native American, and White. Intraclass correlation coefficient was calculated for interobserver reliability and analysis of variance statistical testing to determine statistical significance between groups. Fisher exact test was also used to understand PTS differences among ethnicities when looking at clinically significant values for potential ligamentous injury. Results: Measurements were obtained from 250 specimens with a mean age of 49.4 years (range, 19 to 103 years). The mean PTS was 8.92° (range, –9.4° to 14.95°). Asian Americans had a 1.7° greater mean MPTS than Whites (P = .016), and African Americans/Blacks had a 1.6° greater mean PTS than Whites (P = .022). No difference in mean PTS was seen between age and sex. When looking at clinically significant PTS, 61 (24.4%) individuals had tibial slopes <6° or >12°, 32 (12.8%) and 29 (11.6%), respectively. Statistically significant differences were seen among ethnicities with PTS <6° (P = .017) but not with PTS >12° (P = .106). No sex-based differences were seen in the percentage of specimens with a PTS of >12° or <6°. Conclusion: Among ethnicities, African Americans/Blacks and Asian Americans have increased PTS in comparison with Whites. Nearly 25% of individuals have clinically significant slopes of <6° or >12°, with no difference in tibial slope among sex or age groups.

Paper 82: High Variability Exists Between Longstanding Lateral Radiographs and Standard Lateral Knee Radiographs Evaluating Posterior Tibial Slope in Revision ACL Patients

Objectives:Increased posterior tibial slope (PTS) has been identified as a risk factor for both short-term and long-term failure after anterior cruciate ligament (ACL) reconstruction. Correction of PTS may improve outcomes after revision ACL reconstruction. Conflicting reports demonstrate the most accurate way to measure the PTS on standard short knee radiographs versus longstanding lateral radiographs including the entire tibia. Many reports advocate short knee radiographs as adequate for the evaluation of posterior tibial slope and deciding surgical treatment. The purpose of this study was to compare posterior tibial slope measurements between standard short segment knee (SSK) and longstanding lateral knee radiographs (LSL) in a failed ACL cohort. We hypothesize that there is high variability in SSK measurements compared to LSL. Our secondary hypothesis is that our series of surgical deformity corrections for failed ACL reconstructions with increased PTS includes a significant number of biplanar deformities requiring altered technique to completely address all deformities.Methods:The medial and lateral PTS were measured on 35 consecutive patients with failed ACL reconstructions using SSK and LSL using previously published techniques. Coronal plane deformity was assessed by the tibiofemoral angle on AP long standing films. All measurements were made by two trained independent observers at two different times separated by one month for calculation of inter- and intra-observer reliability using intra-class correlation coefficients (ICCs). Measurements recorded by the observer with the higher intra-observer ICC for the SSK and LSL were used for calculation. Paired t-tests were used for direct comparison of tibial slope measurements between the SSK and LSL conditions. P-values less than 0.05 were considered statistically significant.Results:There was a statistically significant difference in average lateral plateau PTS between standard short knee lateral and longstanding lateral radiographs (11.0 degrees versus 12.2 degrees, P =0.031). More importantly, 66.6% of the absolute measurements differed by at least 3 degrees, with variability as high as 7 degrees in our series as shown in Figures 1 and 2. 20/35 patients (57.1%) also had varus or valgus deformity > 2 degrees. Twelve patients underwent posterior slope correction as part of their revision ACL reconstruction. 8/12 of those patients (66.7%) had varus/valgus deformity > 2 degrees, and 41.7% (5/12) of patients required biplanar proximal tibial osteotomy correction to adequately address their multiplanar deformity.Conclusions:Long segment radiographs more completely evaluate the complex deformities of posterior tibial slope associated with failed ACL reconstruction, with less variability than standard short knee radiographs. In our series, a high percentage of patients needed biplanar correction, and we recommend obtaining long segment anteroposterior and lateral radiographs as essential imaging in these patients.

Relationship Between Posterior Tibial Slope and Lower Extremity Biomechanics During a Single-Leg Drop Landing Combined With a Cognitive Task in Athletes After ACL Reconstruction.

Background:A steeper posterior tibial slope (PTS) is an important risk factor for anterior cruciate ligament (ACL) reinjury. The PTS may affect lower extremity biomechanics under competition-like conditions for athletes with a reconstructed ACL.Hypothesis:It was hypothesized that the PTS would be associated with lower extremity biomechanics, which may increase ACL strain.Study Design:Descriptive laboratory study.Methods:Included were 10 athletes (mean age, 20.9 ± 1.8 years) who had undergone ACL reconstruction. The authors recorded the 3-dimensional lower extremity biomechanics while participants performed a single-leg drop jump with the Stroop task (dual task). Kinematic and kinetic data were analyzed and compared between the involved and contralateral limbs. The medial and lateral PTSs were measured using magnetic resonance imaging scans of the involved knee. The correlation between the biomechanical data and the PTS in each knee was evaluated.Results:The lateral PTS was significantly correlated with the maximum hip adduction moment (r = 0.64; P < .05) and maximum internal tibial rotation angle (r = 0.71; P < .05) in the involved limb. There were no differences in kinematic and kinetic data between the involved and contralateral limbs.Conclusion:In athletes after ACL reconstruction, the lateral PTS was directly associated with the maximum internal tibial rotation angle during single-leg drop landing with a cognitive task.Clinical Relevance:The findings in this study indicate that a steeper lateral PTS may cause internal rotation of the tibia during landing, which may be associated with reinjury in athletes with a reconstructed ACL.

Poster 225: Accuracy of 3D Printed Cutting Guide Versus Free-hand Technique for Anterior Closing Wedge Proximal Tibia Osteotomy in an Animal Model

Objectives:Anterior closing wedge proximal tibia osteotomy (ACWPTO) is an effective treatment for patients with elevated posterior tibial slope (PTS) and recurrent anterior cruciate ligament (ACL) injuries. However, the preoperative planning and surgical execution can be challenging, especially with limited surgeon experience and training. The purpose of this study was to evaluate the initial design of a 3D printed patient-specific cutting guide (PSG) for performing ACWPTO in an animal model. It was hypothesized that the PSG for ACWPTO will more accurately achieve the desired PTS correction compared to a traditional free-hand (FH) technique.Methods:Thirty cadaveric porcine knees underwent lateral radiographs and computed tomography (CT) scans, and were randomly assigned to ACWPTO by PSG or FH technique. Three knees within each group were then assigned to a 10°,12°,14°,16° or 18° correction. Knees assigned to the PSG group then underwent 3D modeling and a PSG was created in SolidWorks to complete the desired PTS correction (Figure 1). Knees assigned to the FH group were templated by an experienced orthopedic surgeon for performing ACWPTO by measuring a pre-determined wedge of bone to be removed from the anterior tibia. Surgeries were then performed by an experienced (attending physician), intermediate (resident physician), and novice surgeon (medical student). Each surgeon performed ACWPTO using the PSG and FH technique for each of the intended angles of correction (10°,12°,14°,16°,18°). Following ACWPTO, post-operative radiographs and CT scans were taken to measure the PTS and the accuracy was determined as the difference between the planned and actual PTS correction (Figure 2). The accuracy, surgical time, and radiation exposure were compared between surgeons using ANOVA. Further analyses to compare the variables of interest between the FH and PSG techniques were conducted using independent samples t-tests.Results:All data are summarized in Tables 1 and 2. Overall, we found the PSG to have significantly faster surgical time (6.4 +/- 2.2 minutes versus 12.0 +/- 3.9 minutes, p < 0.001) and less radiation exposure (8.7 +/- 4.9 mGy versus 58.7 +/- 28.1 mGy, p < 0.001). While the PSG trended towards increased accuracy with radiographic measurements of PTS, this did not reach statistical significance (1.6 +/- 1.6 degrees versus 2.9 +/- 2.0 degrees, p = 0.059). The highest accuracy was found for the resident (intermediate) surgeon using the PSG (0.5 +/- 0.5 degrees), which was significantly more accurate than FH technique for this surgeon (3.6 +/- 2.5 degrees, p = 0.026). Based on CT measurements of medial and lateral PTS we found the FH technique to be as accurate as the PSG (Table 2).Conclusions:One reason for the discrepancy between radiographic and CT measurements may be the lack of standardized methods for measuring PTS in porcine knees. The proximal tibia articular surface has a more complex geometry as compared to human knees, which did make measuring consistent landmarks challenging and is one of the primary limitations of this study. Other limitations of this study include the margin of error in the design of the 3D printed PSG, and accurate placement of the PSG on the proximal tibia. Guide placement was challenging if any cartilage remained around the tibial tubercle as this was not templated in the CT design. Also, PTS measurements can be highly dependent on limb rotation and observer experience. Despite these limitations, this study demonstrated the feasibility of a 3D printed PSG for performing ACWPTO in an animal model. This PSG was as accurate as the free-hand technique based on CT measurements and trended towards improved accuracy based on radiographic measurement of PTS. Future studies are planned to investigate this design in human cadaveric specimens.Table 1.Comparison of Results by Surgeon (Novice vs. Intermediate vs. Expert)Figure 1.A) 3D model of porcine tibia created in SolidWorks to create a patient specific cutting guide to perform anterior closing wedge tibial osteotomy. B) 3D printed patient specific cutting guide for anterior closing wedge tibial osteotomy.Table 2.Comparison of Results by Surgical Technique (Free-hand vs. Patient-Specific Guide)Figure 2.A) Pre-operative radiograph with measurement of posterior tibial slope. B) Post-operative radiograph after anterior closing wedge proximal tibial osteotomy performed with measurement of posterior tibial slope.

A radiographic model predicting the status of the anterior cruciate ligament in varus knee with osteoarthritis

PurposeThe study aims to investigate the accuracy of different radiographic signs for predicting functional deficiency of anterior cruciate ligament (ACL) and test whether the prediction model constructed by integrating multiple radiographic signs can improve the predictive ability.MethodsA total number of 122 patients from January 1, 2018, to September 1, 2021, were enrolled in this study. Among them, 96 patients were classified as the ACL-functional (ACLF) group, while 26 patients as the ACL-deficient (ACLD) group after the assessment of magnetic resonance imaging (MRI) and the Lachman’s test. Radiographic measurements, including the maximum wear point of the proximal tibia% (MWPPT%), tibial spine sign (TSS), coronal tibiofemoral subluxation (CTFS), hip–knee–ankle angle (HKA), mechanical proximal tibial angle (mPTA), mechanical lateral distal femoral angle (mLDFA) and posterior tibial slope (PTS) were measured using X-rays and compared between ACLF and ACLD group using univariate analysis. Significant variables (p < 0.05) in univariate analysis were further analyzed using multiple logistic regression analysis and a logistic regression model was also constructed by multivariable regression with generalized estimating models. Receiver-operating-characteristic (ROC) curve and area under the curve (AUC) were used to determine the cut-off value and the diagnostic accuracy of radiographic measurements and the logistic regression model.ResultsMWPPT% (odds ratio (OR) = 1.383, 95% confidence interval (CI) = 1.193–1.603, p < 0.001), HKA (OR = 1.326, 95%CI = 1.051–1.673, p = 0.017) and PTS (OR = 1.981, 95%CI = 1.207–3.253, p = 0.007) were shown as predictive indicators of ACLD, while age, sex, side, TSS, CTFS, mPTA and mLDFA were not. A predictive model (risk score = -27.147 + [0.342*MWPPT%] + [0.282*HKA] + [0.684*PTS]) of ACLD using the three significant imaging indicators was constructed through multiple logistic regression analysis. The cut-off values of MWPPT%, HKA, PTS and the predictive model were 52.4% (sensitivity:92.3%; specificity:83.3%), 8.5° (sensitivity: 61.5%; specificity: 77.1%), 9.6° (sensitivity: 69.2%; specificity: 78.2%) and 0.1 (sensitivity: 96.2%; specificity: 79.2%) with the AUC (95%CI) values of 0.906 (0.829–0.983), 0.703 (0.574–0.832), 0.740 (0.621–0.860) and 0.949 (0.912–0.986) in the ROC curve.ConclusionMWPPT% (> 52.4%), PTS (> 9.6°), and HKA (> 8.5°) were found to be predictive factors for ACLD, and MWPPT% had the highest sensitivity of the three factors. Therefore, MWPPT% can be used as a screening tool, while the model can be used as a diagnostic tool.

Age, male sex, higher posterior tibial slope, deep sulcus sign, bone bruises on the lateral femoral condyle, and concomitant medial meniscal tears are risk factors for lateral meniscal posterior root tears: a systematic review and meta-analysis.

Lateral meniscus posterior root tears (LMPRTs) are commonly found in patients with anterior cruciate ligament (ACL) injuries. However, risk factors for LMPRTs are not well known. This study was designed to systematically review the available evidence regarding risk factors associated with LMPRTs. The PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for papers containing the key words "lateral meniscus posterior root tears", "LMPRTs" and "risk factor". Inclusion screening, data extraction, and quality assessment of the included articles were conducted independently by two authors. Statistical analysis was conducted to determine risk factors for LMPRTs. Seventeen studies with a total sample size of 6, 589 patients were identified. The pooled prevalence of LMPRTs was 9.6% (range, 5.1-33.8%) for ACL injury. Significant risk factors included a patient age of < 30 [OR = 1.4, 95% CI (1.07, 1.84), p = 0.01], male sex [OR = 1.50, 95% CI (1.24,1.81), p = 0.01], higher body mass index (BMI) [MD = 0.45, 95% CI (0.13, 0.76), p < 0.01], higher lateral posterior tibial slope (LPTS) [MD = 2.22, 95% CI (1.37, 3.07), p < 0.01], deep sulcus sign [OR = 5.76, 95% CI (1.35, 24.52), p < 0.01] and bone bruises on lateral femoral condyle [OR = 4.88, 95% CI (1.27, 18.77), p < 0.01], lateral meniscal extrusion > 1mm [OR = 5.56, 95% CI (1.52, 20.29), p < 0.01] and > 3mm [OR = 12.91 95% CI (1.28, 130.01), p < 0.01], medial meniscal tears [OR = 1.40, 95% CI (1.12, 1.75), p < 0.01], and medial ramp lesions [OR = 2.29, 95% CI (1.35, 3.89), p < 0.01]. Age below 30, male, higher BMI, higher LPTS, deep sulcus sign, bone bruises on lateral femoral condyle, lateral meniscal extrusion, medial meniscal tear, and medial ramp lesion are risk factors for LMPRTs. Level IV.

Posterior Tibial Slope in Patients With Torn ACL Reconstruction Grafts Compared With Primary Tear or Native ACL: A Systematic Review and Meta-analysis

Background:Increased posterior tibial slope (PTS) is a risk factor for anterior cruciate ligament (ACL) rupture and failure of ACL reconstruction (ACLR) grafts.Purpose:The purpose was to conduct a systematic review of literature on PTS measurements and to conduct a meta-analysis of comparable PTS measurements based on a patient’s ACL status. It was hypothesized that patients with torn ACLR grafts would have significantly larger medial and lateral PTS compared with patients with native ACLs or those who underwent primary ACLR.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included were studies that reported medial and/or lateral PTS measurements, those that reported PTS measurements based on ACL status (ie, intact ACL, primary ACL tear, failed ipsilateral ACLR, or revision ACLR), and those that reported their specific PTS measurement technique. Average PTS measurements, measurement location (medial or lateral tibial plateau) and technique, imaging modality used, and ACL status were extracted from each study. Data were pooled using DerSimonian and Laird random-effects models, and results were compared using the Altman interaction test.Results:The literature search identified 1705 studies, of which 82 (N = 12,971 patients) were included. There were 4028 patients in the intact ACL group (31%), 7405 in the primary ACLR group (57%), and 1538 in the failed ACLR group (12%). Measurements were obtained from lateral radiographs in 31 studies (38%), from magnetic resonance imaging in 47 studies (57%), and from computed tomography in 4 studies (5%). The failed ACLR group had a significantly larger lateral PTS (9.55°; 95% CI, 8.47°-10.63°) than either the primary ACL tear (7.13°; 95% CI, 6.58°-7.67°) or intact ACL (5.57°; 95% CI, 5.03°-6.11°) groups (P < .001 for both). The failed ACLR group also had a significantly larger medial PTS (9.05°; 95% CI, 7.80°-10.30°) than the primary (6.24°; 95% CI, 5.71°-6.78°) or intact ACL (6.28°; 95% CI, 5.21°-7.35°) groups (P < .001 for both).Conclusion:Both lateral and medial PTS measurements were greater in patients who had failed previous ACLR than those with a primary ACL tear or an intact native ACL. The lateral PTS of patients with primary ACL tears was greater than those with an intact native ACL.

Medial and Lateral Posterior Tibial Slope in the Skeletally Immature: A Cadaveric Study.

Background:An increased posterior tibial slope (PTS) results in greater force on the anterior cruciate ligament (ACL) and is a risk factor for ACL injuries. Biomechanical studies have suggested that a reduction in the PTS angle may lower the risk of ACL injuries. However, the majority of these investigations have been in the adult population.Purpose:To assess the mean medial and lateral PTS on pediatric cadaveric specimens without known knee injuries.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 39 pediatric knee specimens with computed tomography scans were analyzed. Specimens analyzed were between the ages of 2 and 12 years. The PTS of each specimen was measured on sagittal computed tomography slices at 2 locations for the medial and lateral angles. The measurements were plotted graphically by age to account for the variability in development within age groups. The anterior medial and lateral tibial plateau widths were measured. The distance between the top of the tibial plateau and the physis was measured. The independent-samples t test and analysis of variance were used to analyze the measurements.Results:The mean PTS angle for the medial and lateral tibial plateaus was 5.53° ± 4.17° and 5.95° ± 3.96°, respectively. The difference between the PTS angles of the medial and lateral tibial plateaus was not statistically significant (P > .05). When plotted graphically by age, no trend between age and PTS was identified.Conclusion:This data set offers values for the PTS in skeletally immature specimens without a history of ACL injury and suggests that age may not be an accurate predictive factor for PTS.

Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction.

Although anterior cruciate ligament reconstruction (ACLR) is considered a successful procedure, residual pivot-shift after surgery remains to be solved. The purpose of this study was to comprehensively evaluate the risk factors of residual pivot-shift after anatomic double-bundle (DB) ACLR. A total of 164 patients who underwent primary anatomic DB-ACLR between January 2014 and December 2019 and screw removal after the index ACLR in our hospital were included in this retrospective case-control study. The manual pivot-shift test was performed under general anesthesia during screw removal surgery, and patients with grade 1 or higher pivot-shift were classified as the positive pivot-shift group, and those with grade 0 were defined as the negative pivot-shift group. Univariate and logistic regression analyses were performed to identify the factors associated with postoperative residual pivot-shift. Assessment included sex, age, time to surgery, preoperative Tegner activity scale, preoperative pivot-shift grade, preoperative anterior tibial translation by the KT-2000 arthrometer measurement, meniscus injury and its surgical procedure, knee hyperextension, cartilage damage, Segond fracture, medial and lateral posterior tibial slope, lateral-medial slope asymmetry, participation in pivoting sport/activity at the time of injury, and return to sports at postoperative one year line. Postoperative positive pivot-shift was observed in 14 (8.5%) of 164 patients. The KT-2000 measurement at 1-year postoperatively was significantly higher in the residual pivot-shift-positive group than in the negative group (P < 0.05). Logistic regression analysis revealed that age of patients < 20years [P < 0.05, odds ratio (OR): 6.1)], preoperative pivot-shift grade (P < 0.05, OR: 4.4), and hyperextended knee (P < 0.05, OR: 11.8) were risk factors of postoperative pivot-shift. There were no statistically significant differences between other variables. Patients < 20years of age, with high-grade preoperative pivot-shift, or hyperextended knees had a higher risk of residual postoperative pivot-shift.

Anterior and rotational tibial subluxation in the setting of anterior cruciate ligament injuries: An MRI analysis

BackgroundThe relationship between preoperative tibiofemoral position and failure of anterior cruciate ligament (ACL) reconstruction has been widely discussed. Most established methods for measuring tibiofemoral position on magnetic resonance imaging (MRI) mainly focus on anterior tibial subluxation (ATS), while a quantitative measuring method for rotational tibial subluxation (RTS) is still undetermined. Moreover, there are still controversies about the related factors for ATS. The aim of this study was to quantitatively describe preoperative ATS and RTS in ACL-injured and ACL-intact knees and identify the related factors for ATS and RTS based on MRI images. MethodsDemographic data and preoperative MRIs of 104 ACL-injured patients were retrospectively analyzed. ACL-intact knees were 1:1 matched as control group. ATS was measured using longitudinal tibial axis, and RTS was determined by the difference between lateral and medial ATS. Related factors for ATS and RTS were examined. ResultsIncreased lateral ATS (P < 0.0001), medial ATS (P < 0.0001) and RTS (P = 0.0479) were observed in ACL-injured knees compared with the control group. Increased posterior tibial slope (PTS), Beighton Score ≥ 4, presence of meniscal injury and long injury-to-MRI time were identified as being correlated with the increase of ATS. Factors for the increase of RTS were increased lateral PTS, Beighton score ≥ 4, presence of lateral meniscal injury, and left side. ConclusionsIn ACL-injured knees, tibia not only subluxated anteriorly in both lateral and medial compartments, but also rotated internally. During preoperative planning, attentions should be paid to the factors that are correlated with altered tibiofemoral position.

The influence of the steep medial posterior tibial slope on medial meniscus tears in adolescent patients: a retrospective case-control study

BackgroundSeveral studies have demonstrated a relationship between the posterior tibial slope (PTS) and meniscal tears in adults. However, little is known about the association between the PTS of the adolescents and medial meniscal tears (MMT). The purpose of this study was to evaluate the association between the PTS and MMT in adolescents, and to determine the optimal cut-off values of PTS for discriminating between the MMT and the control groups.MethodsBetween January 2018 and January 2020, a retrospective case-control study was performed. In this study, isolated MMT adolescent patients with no ligamentous injuries were matched by age and sex to a control group of radiologically normal images. The PTS was defined as the angle between the perpendicular line to proximal tibial cortex (PTC) and the tangent line along the tibial plateau. Then, both the medial posterior tibial slope (MPTS) and lateral posterior tibial slope (LPTS) were measured by plain radiographs on the lateral views. In addition, the optimal cut-off values of PTS were determined by the receiver operating characteristic (ROC) curve analysis.ResultsA total of seventy-two patients who met the inclusion criteria were enrolled in the final analysis (36 patients with isolated MMT, 36 controls). The MPTS was greater in the knees with isolated MMT (10.7° ± 2.1°) than that of the control group (8.8° ± 1.7°), showing significant difference (P<0.001). However, there was no significant difference regarding the LPTS between the isolated MMT and controls (11.5 ± 3.4 vs 10.9 ± 2.6, p>0.05). In the ROC curve analysis, the calculated cutoff value of the MPTS discriminating between the groups was 10.3°, with a sensitivity of 73.3% and specificity of 78.9%.ConclusionsThis study demonstrated that steep MPTS is associated with MMT, and MPTS≥10.3° was identified to be a risk factor for MMT in adolescents.

The treatment of posterolateral tibial plateau fracture with a newly designed anatomical plate via the trans-supra-fibular head approach: preliminary outcomes

BackgroundThere are no ideal plates or approaches for anatomical restoration and rigid fixation of posterolateral tibial plateau fractures. This study aimed to evaluate the short-term preliminary outcomes of our novel anatomical plate placed via the trans-supra-fibular approach to treat posterolateral tibial plateau fractures.MethodsFrom May 2016 to May 2018, 23 consecutive patients with posterolateral tibial quadrant fractures underwent open reduction with internal fixation via the trans-supra-fibular-head approach with our newly developed plate. The tibial plateau-tibial shaft angle (TPTSA), lateral posterior tibial slope angle (LPSTA), step-off, and condylar widening were measured on radiological images pre-operatively, 3 days post-operatively, 3 months post-operatively, and at the final follow-up examination. The radiological Rasmussen score was calculated, and the Hospital for Special Surgery (HSS) knee score was assessed to evaluate the functional outcomes.ResultsThe LTPSA, TPTSA, step-off, and condylar widening at 3 days post-operatively, 3 months post-operatively, and at the final follow-up were significantly different (p = 0.001) compared with those pre-operatively, as was the radiological Rasmussen score (p = 0.001). The HSS score at the final follow-up was 89.10 ± 5.94 (range, 78–98), which was significantly higher than that at the 3-month follow-up 84.36 ± 6.76 (range, 74–96); p = 0.001).ConclusionsOur newly designed anatomical plate placed via the trans-supra-fibular approach can effectively treat posterolateral tibial plateau fractures. We noted minor trauma, stable fixation, and satisfactory clinical results.

Wide variation in tibial slopes and trochlear angles in the arthritic knee: a CT evaluation of 4116 pre-operative knees

As surgeons continue to grapple with persistent issues of patient dissatisfaction post-TKA, the literature has focused on the coronal plane when considering alignment strategies but has largely ignored the sagittal and axial planes. The purpose of this retrospective observational cohort study is to evaluate variability in knee anatomy and alignment beyond the coronal plane and rationalise how this relates to existing arthroplasty alignment philosophies. 4116 knee CTs from 360 Knee Systems© database of arthritic pre-operative TKA patients were evaluated. Standardised bony landmarks were used in each CT to determine the hip-knee angle, medial proximal tibial angle, lateral distal femoral angle, medial plateau posterior tibial slope, lateral plateau posterior tibial slope, trochlea angle (TA) to distal femoral angle (TA-DFA) and TA to posterior condylar angle (TA-PCA). Analysis was performed to determine the distributions of each measure across the cohort population. Both the medial and lateral PTS ranged from 5° anterior to 25° posterior. 22.6% of patients had differential PTS greater than 5°. 14.5% have greater lateral PTS (mean difference to medial PTS of 4.8° ± 5.0°), whilst 31.0% have greater medial PTS (mean difference to lateral PTS of 5.7° ± 3.2°). 14% of TA-DFAs and 5.2% of TA-PCAs vary greater than 10°. This study demonstrates a wide variation in tibial slope, differential slope between the medial and lateral tibial plateau as well as variation in the trochlear geometry. There has been an overemphasis in the literature on coronal alignment, ignoring the considerable variability present in tibial and patellofemoral morphology. Existing arthroplasty techniques are based on assumptions that may not adequately address the anatomy of morphologic outliers and could lead to dissatisfaction. III-retrospective cohort study.

The correlation between posterior tibial slope and dynamic anterior tibial translation and dynamic range of tibial rotation

PurposeThe amount of passive anterior tibial translation (ATT) is known to be correlated to the amount of posterior tibial slope (PTS) in both anterior cruciate ligament-deficient and reconstructed knees. Slope-altering osteotomies are advised when graft failure after anterior cruciate ligament (ACL) reconstruction occurs in the presence of high PTS. This recommendation is based on studies neglecting the influence of muscle activation. On the other hand, if dynamic range of tibial rotation (rTR) is related to the amount of PTS, a “simple” anterior closing-wedge osteotomy might not be sufficient to control for tibial rotation. The purpose of this study was to evaluate the correlation between the amount of PTS and dynamic ATT and tibial rotation during high demanding activities, both before and after ACL reconstruction. We hypothesized that both ATT and rTR are strongly correlated to the amount of PTS.MethodsTen subjects were studied both within three months after ACL injury and one year after ACL reconstruction. Dynamic ATT and dynamic rTR were measured using a motion-capture system during level walking, during a single-leg hop for distance and during a side jump. Both medial and lateral PTS were measured on MRI. A difference between medial and lateral PTS was calculated and referred to as Δ PTS. Spearman’s correlation coefficients were calculated for the correlation between medial PTS, lateral PTS and Δ PTS and ATT and between medial PTS, lateral PTS and Δ PTS and rTR.ResultsLittle (if any) to weak correlations were found between medial, lateral and Δ PTS and dynamic ATT both before and after ACL reconstruction. On the other hand, a moderate-to-strong correlation was found between medial PTS, lateral PTS and Δ PTS and dynamic rTR one year after ACL reconstruction.ConclusionDuring high-demand tasks, dynamic ATT is not correlated to PTS. A compensation mechanism may be responsible for the difference between passive and dynamic ATT in terms of the correlation to PTS. A moderate-to-strong correlation between amount of PTS and rTR indicates that such a compensation mechanism may fall short in correcting for rTR. These findings warrant prudence in the use of a pure anterior closing wedge osteotomy in ACL reconstruction.Trial registrationNetherlands Trial Register, Trial 7686. Registered 16 April 2016—Retrospectively registered.Level of evidenceLevel 2, prospective cohort study

Effect of Time on MRI Appearance of Graft After ACL Reconstruction: A Comparison of Autologous Hamstring and Quadriceps Tendon Grafts

Background:After anterior cruciate ligament (ACL) reconstruction (ACLR), changes in the appearance of the ACL graft can be monitored using magnetic resonance imaging (MRI).Purpose:The purpose of this study was to evaluate and compare the MRI signal intensity (SI) of hamstring and quadriceps tendon grafts during the first postoperative year after ACLR. As a secondary aim, the relationship of SI to clinical and anatomic measurements was analyzed.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 78 patients who underwent ACLR with an autologous graft were reviewed; 55 received hamstring grafts and 23 received quadriceps tendon grafts. At 3 and 9 months postoperatively, 3-T MRI was performed using a dedicated knee coil, and the median SI of the intra-articular ACL graft was measured on sagittal-plane images. Postoperative lateral radiographs were analyzed to determine medial and lateral posterior tibial slope (PTS). Side-to-side difference in anterior knee laxity between injured and uninjured limbs was measured at 6 and 12 months postoperatively.Results:The median SI of quadriceps grafts was significantly greater than hamstring grafts at 3 months after ACLR (P = .02). Between 3 and 9 months, the median SI of quadriceps grafts decreased (P < .001), while that of hamstring grafts did not significantly change (P = .55). The lateral PTS was significantly correlated with median SI measurements at 3 and 9 months such that greater lateral PTS values were associated with greater median SI. The side-to-side difference in anterior knee laxity decreased for the quadriceps group (P = .04) between 6 and 12 months but did not change for the hamstring group (P = .88).Conclusion:The median SI of quadriceps grafts significantly decreased on MRI between 3 and 9 months after ACLR, while the median SI of hamstring grafts did not significantly change. The change in MRI appearance of the quadriceps grafts was paralleled by a reduction in anterior knee laxity between 6 and 12 months after surgery. In the absence of standardized imaging techniques and imaging analysis methods, the role of MRI in determining graft maturation, and the implications for progression through rehabilitation to return to sport, remain uncertain.

Medial and Lateral Posterior Tibial Slope Are Independent Risk Factors for Noncontact ACL Injury in Both Men and Women.

Background:Higher posterior tibial slope (PTS) is a risk factor for anterior cruciate ligament (ACL) injury in men and women. The individual contribution of the lateral (LPTS) and medial (MPTS) slope has not yet been investigated.Purpose:To determine whether either the LPTS or the MPTS is an independent risk factor for ACL injury, and to determine sex-specific differences between patients with ACL-deficient and ACL-intact knees.Study Design:Cohort study; Level of evidence, 3.Methods:We reviewed knee magnetic resonance (MR) images performed on ACL-deficient and ACL-intact knees between January 2018 and June 2020 at a single institution. Inclusion criteria were isolated ACL injury and noncontact mechanism (ACL-deficient group) and nonspecific knee pain and no history of injury (ACL-intact group). Exclusion criteria for both groups were the following: previous knee surgery; meniscal, collateral ligament, posterior cruciate ligament, or multiligamentous injuries; radiological evidence of osteoarthritis; and chondral damage on the tibia. The MR images were used to establish the posterior bony slope at 25%, 50%, and 75% from the medial and/or lateral border of the tibial plateau with respect to the proximal tibial anatomic axis. One-way analysis of variance (ANOVA) was used to determine differences in PTS at the 25%, 50%, and 75% distances for the medial and lateral tibial plateau between the groups and between the sexes.Results:Overall, 325 images were included (mean age, 36.1 ± 11.1 years; 142 ACL-deficient images [82 men and 60 women]; 183 ACL-intact images [112 men and 71 women]). MPTS and LPTS were significantly higher at 25%, 50%, and 75% in the ACL-deficient group (range, –2.7° to –5.7°) compared with the ACL-intact group (range, –2.1° to 1.5°; P = .00001). Similarly, MPTS and LPTS were significantly different in men versus women (P = .00001). ANOVA revealed that there were no significant differences in PTS between men and women for all measures (MPTS, LPTS, ACL-deficient, ACL-intact; P = .68).Conclusion:The study results demonstrated that higher MPTS and LPTS is a potential risk factor for ACL injury in both men and women. However, despite being highly statistically significant, the differences between groups and sexes were small and may not be clinically relevant.

Feasibility study of early prediction of postoperative MRI findings for knee stability after anterior cruciate ligament reconstruction

BackgroundAt present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability.MethodsWe retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group (n = 57) and an unstable group (n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation.ResultsThere were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction (P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors (P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%.ConclusionsWe found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.

Increased Posterior Tibial Slope is Associated with Revision Anterior Cruciate Ligament Reconstruction Graft Re-Rupture

Objectives:Anterior cruciate ligament reconstruction (ACLR) graft failure continues to be a problem with failure rates reported up to 11%. Following revision ACLR, 3.3 – 4.3% of these patients suffer re-tear of the revision ACL graft. The purpose of this study was to evaluate the influence of posterior tibial slope (PTS) on ACL graft re-tear after revision ACLR. It was hypothesized that increased posterior tibial slope (PTS) is associated with an increased risk of ACL graft re-tear following revision ACLR.Methods:Retrospective chart review identified patients who underwent revision ACLR between 2005 and 2016 at a single institution. Patients who suffered an ACL re-tear following revision surgery were matched by age, sex, and graft type to controls who had intact revision ACLR grafts at a minimum of 2 years follow-up. Medial posterior tibial slope (MPTS) and lateral posterior tibial slope (LPTS) were measured on lateral radiographs and sagittal magnetic resonance imaging (MRI). Tibial slope was then compared between groups using independent sample t-tests.Results:Twenty-nine patients with a graft failure after revision ACLR were included and compared to 29 matched controls with a mean follow-up of 5.8 years (range: 2 to 11.3 years). Each group included 16 males and 13 females. Average age was 26 +/- 8.3 years at time of revision ACLR. Both x-ray and MRI demonstrated increased LPTS in the failure group versus controls (12.7 ± 3.2 degrees vs. 10.6 ± 3.6 degrees, p = 0.02 and 8.1 ± 3.4 degrees vs. 5.0 ± 3.5 degrees, p = 0.001, respectively). There was no significant difference in MPTS between the failure and control groups on x-ray (11.9 ± 2.9 degrees vs. 11.1 ± 3.6 degrees, p = 0.3772) nor MRI (4.3 ± 3.5 degrees vs. 3.3 ± 3.0 degrees, p = 0.2486).Conclusions:Matching for age, sex, and graft type, increased LPTS measured on both x-ray and MRI is associated with increased risk of a subsequent ACL injury following revision ACLR. Identification of at-risk patients may guide pre-operative discussions regarding revision ACL graft failure risk.