Post-concussive mTBI in Student Athletes: MRI Features and Machine Learning

Purpose: To determine and characterize the radiomics features from structural MRI (MPRAGE) and Diffusion Tensor Imaging (DTI) associated with the presence of mild traumatic brain injuries on student athletes with post-concussive syndrome (PCS).Material and Methods: 122 student athletes (65 M, 57 F), median (IQR) age 18.8 (15–20) years, with a mixed level of play and sports activities, with a known history of concussion and clinical PCS, and 27 (15 M, 12 F), median (IQR) age 20 (19, 21) years, concussion free athlete subjects were MRI imaged in a clinical MR machine. MPRAGE and DTI-FA and DTI-ADC images were used to extract radiomic features from white and gray matter regions within the entire brain (2 ROI) and the eight main lobes of the brain (16 ROI) for a total of 18 analyzed regions. Radiomic features were divided into five different data sets used to train and cross-validate five different filter-based Support Vector Machines. The top selected features of the top model were described. Furthermore, the test predictions of the top four models were ensembled into a single average prediction. The average prediction was evaluated for the association to the number of concussions and time from injury.Results: Ninety-one PCS subjects passed inclusion criteria (91 Cases, 27 controls). The average prediction of the top four models had a sensitivity of 0.80, 95% CI: [0.71, 0.88] and specificity of 0.74 95%CI [0.54, 0.89] for distinguishing subjects from controls. The white matter features were strongly associated with mTBI, while the whole-brain analysis of gray matter showed the worst association. The predictive index was significantly associated with the number of concussions (p < 0.0001) and associated with the time from injury (p < 0.01).Conclusion: MRI Radiomic features are associated with a history of mTBI and they were successfully used to build a predictive machine learning model for mTBI for subjects with PCS associated with a history of one or more concussions.

Low serum calcium is associated with perioperative blood loss and transfusion rate in elderly patients with hip fracture: a retrospective study

Background To investigate whether hypocalcemia influenced total blood loss and transfusion rate in elderly patients with hip fracture. Methods From our hip fracture database, patients were consecutively included between January 2014 and December 2020. Serum calcium level was corrected for albumin concentration, and hypocalcaemia was defined as corrected calcium < 2.11 mmol/L. Hemoglobin and hematocrit were obtained on admission day and postoperative day, and blood transfusions were collected. According to the combination formulas of Nadler and Gross, the total blood loss of each patient was calculated. Risk factors were further analyzed by multivariate linear regression. Results A total of 583 consecutive elderly hip fracture patients were finally included (mean age 79.32 ± 8.18 years, 68.61% female). On admission, the mean serum corrected calcium level was 2.17 ± 0.14 mmol/L, and the prevalence of hypocalcemia was 33.11% (95% CI: 29.42–37.02). When comparing patients with normal calcium, hypocalcemia patients exhibited a higher blood transfusion rate (7.69% vs 16.06%, P < 0.05), and significantly larger total blood loss (607.86 ± 497.07 ml vs 719.18 ± 569.98 ml, P < 0.05). Multivariate linear regression analysis showed that male, anemia on admission, time from injury to hospital, intertrochanteric fracture, blood transfusion and hypocalcemia were independently associated with increased total blood loss (P < 0.05). Conclusion Hypocalcemia is common in elderly patients with hip fracture, and significantly associated with more total blood loss and blood transfusion. The other risk factors for increased total blood loss are male, anemia on admission, time from injury to hospital, intertrochanteric fracture, and blood transfusion. Level of evidence Level III, retrospective study.

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction

Background: A significant proportion of patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) later experience graft failure. Some studies suggest an association between a steep posterior tibial slope (PTS) and graft failure. Purpose: To examine the PTS in a large cohort of patients about to undergo ACLR and to determine whether a steep PTS is associated with later revision surgery. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective review of a cohort undergoing isolated ACLR between 2002 and 2012 (with 8-19 years of follow-up) was conducted. Preoperative sagittal radiographs of knees in full extension were used for measurements of the PTS. There were 2 independent examiners who performed repeated measurements to assess the reliability of the method. Statistical analyses were performed to compare the PTS in the groups with and without later revision surgery. Results: A total of 728 patients, with a mean age of 28 years at the time of surgery, were included. Overall, 10% (n = 76) underwent revision surgery during the observation period. The group of injured knees had a significantly steeper PTS compared with the group of uninjured knees (9.5° vs 8.7°, respectively; P < .05). The mean PTS in the no revision group was 9.5° compared with 9.3° in the revision group (not significant). Dichotomized testing of revision rates related to PTS cutoff values of ≥10°, ≥12°, ≥14°, ≥16°, and ≥18° showed no association of PTS steepness (not significant) to graft failure. Patients with revision were younger than the ones without (mean age, 24 ± 8 vs 29 ± 10 years, respectively) and had a shorter time from injury to ACLR (mean, 14 ± 27 vs 24 ± 44 months, respectively) as well as a smaller graft size (8.2 vs 8.4 mm, respectively; P = .040). Conclusion: The current study did not find any association between a steep PTS measured on lateral knee radiographs and revision ACL surgery. However, a steeper PTS was seen in the group of injured knees compared with the group of uninjured (contralateral) knees. Independent of the PTS, younger patients, those with a shorter time from injury to surgery, and those with a smaller graft size were found to undergo revision surgery more often.

Knee Hyperextension Greater Than 5° Is a Risk Factor for Failure in ACL Reconstruction Using Hamstring Graft

Background: The degree of knee hyperextension in isolation has not been studied in detail as a risk factor that could lead to increased looseness or graft failure after anterior cruciate ligament (ACL) reconstruction. Purpose: To analyze whether more than 5° of passive knee hyperextension is associated with worse functional outcomes and greater risk of graft failure after primary ACL reconstruction with hamstring tendon autograft. Study Design: Cohort study; Level of evidence, 3. Methods: A cohort of patients who had primary ACL reconstruction with hamstring tendon autografts was divided into 2 groups based on passive contralateral knee hyperextension greater than 5° (hyperextension group) and less than 5° (control group) of hyperextension. Groups were matched by age, sex, and associated meniscal tears. The following data were collected and compared between the groups: patient data (age and sex), time from injury to surgery, passive knee hyperextension, KT-1000 arthrometer laxity, pivot shift, associated meniscal injury and treatment (meniscectomy or repair), contralateral knee ligament injury, intra-articular graft size, follow-up time, occurrence of graft failure, and postoperative Lysholm knee scale and International Knee Documentation Committee subjective form scores. Results: Data from 358 patients initially included in the study were analyzed; 22 were excluded because the time from injury to surgery was greater than 24 months, and 22 were lost to follow-up. From the cohort of 314 patients, 102 had more than 5° of knee hyperextension. A control group of the same size (n = 102) was selected by matching among the other 212 patients. Significant differences in the incidence of graft failure (14.7% vs 2.9%; P = .005) and Lysholm knee scale score (86.4 ± 9.8 vs 89.6 ± 6.1; P = .018) were found between the 2 groups. Conclusion: Patients with more than 5° of contralateral knee hyperextension submitted to single-bundle ACL reconstruction with hamstring tendons have a higher failure rate than patients with less than 5° of knee hyperextension.

Massive Pediatric Burn Injury : A ten-year review

Advances in the care of burn injured pediatric patients has improved mortality over the last 20 years. However, massive burn injuries (50% total body surface area or greater) in pediatric patients, while overall rare, have a significant morbidity and mortality. The primary aim for this study is to analyze treatment and outcomes in massive pediatric burn injuries. A retrospective study of children with burn injuries 50% TBSA or greater who were admitted to Shriners Hospital for Children Northern California, from May 1, 2009 to May 22, 2020 was conducted. Data was collected from the electronic health records through a comprehensive chart review that included: patient demographics, past medical history, treatment interventions and outcomes. This study included 69 patients (59.4% male) with a mean age of 8.7 ± 6 years old. The median time from injury to admission was 2 (1- 4) days. 63.8% of patients were from Mexico, 34.8% were from the United States and 1 patient was from American Samoa. The median time from injury to admission was 2 (1- 4) days. Mean TBSA was 66 ± 12 %. The median TBSA of second-degree burns was 0 (0- 6)%, and the mean TBSA of third-degree burns was 60 ± 16%. 40% of patients suffered an inhalation injury and 83% of patients received a tracheostomy. The median number of days requiring ventilator assistance was 26 (12-58) days. Mean length of hospitalization was 90 ± 60 days, with 61 ± 41 days spent in the ICU. The mean number surgical procedures were 6 ± 4. The time between surgical procedures was 12 ± 6 days. The median time from admission to the first surgical procedure was 1 (0-2) day. At the first procedure, a mean 42 ± 15% TBSA of the burn injury was excised. 62% of patients received autografting (22 ± 11% TBSA) and 52% of patients received allografting (27 ± 17% TBSA) during the first procedure. For survivors, the median number of inpatient occupational therapy encounters were 143.5 (83-215) and inpatient physical therapy encounters were 139.5 (81-215). 25% of the patients included in this study died as a result of their burn injury. Multivariate regression revealed that sustaining an inhalation injury was a significant and independent predictor of death (OR- 3.4, (1.05-11 95% CI), p=0.04). Massive burn injuries in children required a very high number of surgical procedures and hospital resources. Most children who died as a result of their massive burn injury, died within the first month of admission. Inhalation independently increases the risk of dying in pediatric patients with a massive burn injury.

A Longer Duration from Injury to Surgery is Associated with Preoperative Deterioration of an Isolated Meniscal Tear in Patients Aged 40 Years or Older

Background: It remains unclear what percentage of isolated meniscal tears deteriorates before surgery, especially in older patients. We aimed to evaluate the preoperative deterioration of an isolated meniscal tear in patients aged 40 years or older, and whether time from injury to surgery is associated with worsening of a meniscal tear.Methods: Patients aged 40 years or older who underwent arthroscopic surgery for isolated meniscal tear between 2014 and 2019 were retrospectively reviewed. The diagnostic magnetic resonance imaging (MRI) findings and arthroscopic findings were compared to evaluate the deterioration of meniscal tears. Predictors of the development of meniscal tears; patient demographic factors, duration from injury to surgery (injury to MRI and MRI to surgery), and image findings were assessed. Results: A total of 58 patients (58 knees) were included (mean age, 55.9 ± 8.5 years; male/female, 31/27). An isolated meniscal tear deteriorated in 28 (48.3%). In comparison of patients with and without deteriorated meniscal tear, significant differences were found in the MRI grade of meniscal tear (p = 0.03), duration from injury to MRI (164.2 ± 167.9 vs. 45.2 ± 48.7 days, p < 0.001), and from MRI to surgery (148.8 ± 91.1 vs. 67.6 ± 56.7 days, p < 0.001). A multivariate regression analysis showed that the duration from injury to MRI (odds ratio [OR], 1.03; p < 0.001) and from MRI to surgery (OR, 1.02; p < 0.001) were independent predictors of worsening of a meniscal tear. Conclusions: Approximately 50% of isolated meniscal tears deteriorated preoperatively in patients aged 40 years or older. The duration from injury to MRI and from MRI to surgery were independent predictors of the preoperative worsening of an isolated meniscal tear in this cohort.

Age, time from injury to surgery and hop performance after primary ACLR affect the risk of contralateral ACLR

Purpose To evaluate factors affecting the risk of contralateral anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR. Methods Primary ACLRs performed at Capio Artro Clinic, Stockholm, Sweden, during the period 2005–2014, were reviewed. The outcome of the study was the occurrence of contralateral ACLR within 5 years of primary ACLR. Univariable and multivariable logistic regression analyses were employed to identify preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for contralateral ACLR. Results A total of 5393 patients who underwent primary ACLR were included. The incidence of contralateral ACLR within 5 years was 4.7%. Univariable analysis revealed that age ≥ 25 years, BMI ≥ 25 kg/m2, time from injury to surgery ≥ 12 months and the presence of a cartilage injury reduced the odds, whereas female gender, pre-injury Tegner activity level ≥ 6, quadriceps and hamstring strength and a single-leg-hop test LSI of ≥ 90% increased the odds of contralateral ACLR. Multivariable analysis showed that the risk of contralateral ACLR was significantly affected only from age ≥ 25 years (OR 0.40; 95% CI 0.28–0.58; P < 0.001), time from injury to surgery ≥ 12 months (OR 0.48; 95% CI 0.30–0.75; P = 0.001) and a single-leg-hop test LSI of ≥ 90% (OR 1.56; 95% CI 1.04–2.34; P = 0.03). Conclusion Older age (≥ 25 years) and delayed primary ACLR (≥ 12 months) reduced the odds, whereas a symmetrical (LSI ≥ 90%) 6-month single-leg-hop test increased the odds of contralateral ACLR within 5 years of primary ACLR. Knowledge of the factors affecting the risk of contralateral ACLR is important when it comes to the appropriate counselling for primary ACLR. Patients should be advised regarding factors affecting the risk of contralateral ACLR. Level of evidence Level III.

Factors Influencing the Outcomes of a Validated Return to Sports Test Battery After ACL Reconstruction: A Retrospective Analysis of 676 Patients (187)

Objectives: Second ACL injuries (defined as a graft rupture or contralateral ACL rupture) are common after ACL reconstruction. It is postulated that this observation could reflect a premature attempt to return to sports (RTS) and that delaying RTS until certain quality indicators or rehabilitation milestones are met could reduce the risk. There is consequently considerable interest in the application of RTS criteria. Multiple authors have reported that patients who passed a battery of tests prior to RTS, had a lower risk of re-injury and an increased rate of return to sport. However, factors influencing RTS scores have not been well studied. Therefore, the aim of this study was to determine the key factors that influence RTS test scores. Methods: A retrospective analysis of consecutive patients who underwent primary ACL reconstruction between March 2016 and May 2017, who also had a documented RTS evaluation with K-STARTS, (a validated, composite psychological and functional RTS test battery (Fig 1)) at 6 months following surgery, was undertaken. All patients underwent the same standardized rehabilitation program (Table 1) but in addition to this they were offered the opportunity to participate in a separate individualized RTS program (Table 2). If patients chose to participate in the RTS program, this would occur in addition to the standard program and not instead of it. The first session would typically occur 3 months post-operatively and comprised of ten sessions that took place over a 12-week period. Demographic data and characteristics including the frequency of pre-injury sports participation, Tegner score, time from injury to surgery, graft type, the presence of meniscal lesions, whether a lateral tenodesis was performed, and whether patients participated in the specific RTS program in addition to physiotherapy were recorded. To identify factors influencing the K-STARTS score at six months postoperatively, an analysis of variances was performed. When a significant effect was found, post hoc comparisons were made using Tukey’s HSD tests with Bonferroni’s correction. Results: 676 patients were included in the study. Outcomes of the analysis of the influence of factors on the K-STARTS score is comprehensively presented in Table 3. The K-STARTS score was significantly higher in males than females (13.9 vs 12.4, p<0.001), in younger patients (those aged less than 30 vs older patients, 14.2 vs 12, p<0.001), ACL reconstructions performed with hamstring tendon autografts compared to bone-patellar tendon-bone (13.5 vs 13.1, p=0.03) and in those who completed a specific RTS program in addition to standard rehabilitation, compared to those who did not participate (17.1 vs 13.1, p<0.001). However, the only factor that significantly influenced the K-STARTS score beyond the minimal detectable change threshold (previously determined to be 3.3 points) was the completion of the additional RTS program. The pre-injury frequency of sports participation, whether the dominant limb was injured, time from injury to surgery, the presence of associated meniscal injuries and whether a lateral tenodesis was performed, did not significantly influence the K-STARTS score. Conclusions: Completion of a specific return to sports program, in addition to standard rehabilitation, was the most important factor influencing the K-STARTS composite functional and psychological return to sports test score at 6 months after ACL reconstruction.

Early Knee Osteoarthritis Changes Pre- And Post-Anterior Cruciate Ligament Reconstruction Assessed By the Semi-Quantitative MRI Osteoarthritis Knee Score (MOAKS) Case Series and Case-Control Study

Background: Semi-quantitative scoring of knee abnormalities on magnetic resonance imaging (MRI) can aid in the diagnosis of early stage knee osteoarthritis (OA). Injuries to the anterior cruciate ligament (ACL) and medial meniscus (MM) can contribute to the development of knee OA, but their relationship to its time of onset is unknown.Purpose: To analyze the factors contributing to early knee OA changes in ACL injured knees using MRI Osteoarthritis Knee Score (MOAKS). Methods: Thirty-four cases status post unilateral ACL reconstruction (ACLR) were included. Knee OA abnormalities were evaluated using MOAKS scores of MRIs performed pre- and post-ACLR. Using multiple linear regression analysis, the MOAKS scores of medial osteophytes, medial cartilage alteration, and patellofemoral cartilage alteration were determined as dependent variables. Age, the presence of a meniscal abnormality, the time from injury to ACLR, and body mass index (BMI) were determined as explanatory variables. MOAKS differences between knees with and without medial meniscus (MM) abnormality were tested for each variable using a 2-way repeated-measures analysis of variance with the factors of preoperative vs. postoperative status and MM abnormality. Results: In the pre-ACLR multiple linear regression analysis, the waiting period was significantly and positively associated with medial cartilage loss, Lateral femorotibial osteophytes, lateral cartilage loss. and BMI were positively associated with MM abnormalities. BMI and lateral meniscus (LM) abnormality were significantly associated with lateral cartilage loss. Age was significantly associated with medial osteophytes. Age and LM abnormality were significantly associated with lateral osteophytes. Age, BMI, and LM abnormality were significantly associated with patellofemoral osteophytes. Conclusion: We found early knee OA changes in most knees a mean of 28.2 ± 52.0 months after ACL injury. The time from injury to ACLR, BMI, and the presence of MM or LM abnormality in the ACL injured knee were associated with early knee OA changes. In the ACL injured knee with MM involvement, prompt ACLR may forestall the development of OA.

Radiological Comparison of Meniscofemoral Ligaments in Patients with Intact and Ruptured Anterior Cruciate Ligament

Background: Evaluating concomitant injury in patients with anterior cruciate ligament (ACL) rupture is important for predicting long-term results. Meniscofemoral ligament (MFL) rupture has been observed in patients with anterior cruciate ligament rupture in arthroscopic evaluation for ruptured ACL. Objectives: The objective of this study was to investigate the concomitant meniscofemoral ligaments injury in patients with anterior cruciate ligament ruptures via magnetic resonance imaging (MRI). Methods: A total of 200 patients (with ruptured ACL, n = 100; with intact ACL, n = 100) were retrospectively evaluated via MRI. In the group with ruptured ACL; the patients who were diagnosed as having noncontact ACL injuries and had undergone primary ACL reconstructions were included. The control group included 100 patients with suspected ACL rupture (from a similar injury mechanism) and whose MRI revealed an intact ACL. In the group with ruptured ACL, the time from injury to MRI was evaluated. A comparison of the presence of anterior MFL (aMFL) and posterior MFL (pMFL) between the two groups was evaluated. Results: In the ACL ruptured group, a significantly lower presence of aMFL or pMFL was observed compared to the control group (P = 0.001). The time from injury to MRI was significantly higher in the patients with absent MFL defined in MRI relative to the other groups (P = 0.001). Conclusions: We observed absence of MFLs (aMFL and pMFL) in a significant majority of patients with ruptured ACLs. Furthermore, we found a significant relationship between the time from injury to MRI and absence of MFL in the ruptured ACL group.