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There is an increasing need for articular cartilage restoration procedures. Hyaline cartilage lacks intrinsic healing capacity. Persistent osteochondral defects can lead to early and rapid degenerative changes. Microfracture and autologous chondrocyte implantation provide reasonable outcomes for smaller defects without bone loss. However, these techniques have limited effectiveness for lesions greater than 4 cm2 or with significant bony involvement. Ostochondral allografts provide an option for these lesions. This article reviews osteochondral allografts for articular defects. Emerging options provide different approaches to difficult cartilage defects. We discuss current screening, procurement, and storage methods, surgical techniques, outcomes, and bacterial/viral transmission.

Background: Understanding the risk factors for loss to follow-up in prospective clinical studies may allow for a targeted approach to minimizing follow-up bias and improving the generalizability of conclusions in anterior cruciate ligament reconstruction (ACLR) and other sports-related interventions. Purpose: To identify independent risk factors associated with failure to complete (ie, loss to follow-up) patient-reported outcome measures (PROMs) at 2 years after ACLR within a well-funded prospective longitudinal cohort. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: All patients undergoing primary or revision ACLR enrolled in the prospectively collected database of the multicenter consortium between 2002 and 2008 were included. Multivariate regression analyses were conducted to determine which baseline risk factors were significantly associated with loss to follow-up at a minimum of 2 years after surgery. Predictors assessed for loss to follow-up were as follows: consortium site, sex, race, marital status, smoking status, phone number provided (home or cell), email address provided (primary or secondary), years of school completed, average hours worked per week, working status (full-time, part-time, homemaker, retired, student, or disabled), number of people living at home, and preoperative PROMs (Knee injury and Osteoarthritis Outcome Score, Marx Activity Rating Scale, and International Knee Documentation Committee). Results: A total of 3202 patients who underwent ACLR were enrolled. The 2-year PROM follow-up rate for this cohort was 88% (2821 of 3202). Multivariate analyses showed that patient sex (male: odds ratio [OR], 1.80) and race (black: OR, 3.64; other nonwhite: OR, 1.81) were independent predictors of 2-year loss to follow-up of PROMs. Education level was a nonconfounder. Conclusion: While education level did not predict loss to follow-up, patients who are male and nonwhite are at increased risk of loss to follow-up of PROM at 2 years. Capturing patient outcomes with minimal loss depends on equitable, not equal, opportunity to maximize generalizability and mitigate potential population-level health disparities. Registration: NCT00478894 (ClinicalTrials.gov identifier).

Background Anterior tibial spine fractures (ATSF) in the skeletally immature parallel anterior cruciate ligament (ACL) tears in adult patients, yet these injuries are generally regarded as mutually exclusive. Biomechanical analysis suggests that intrinsic ACL damage occurs during ATSF, and long-term clinical studies demonstrate residual anteroposterior knee laxity following ATSF. We aim to describe prevalence, demographics, and characteristics of pediatric patients who sustained ATSF with concomitant ACL injury. Methods We included 129 patients with ATSF over a 16-year period. Age, sex, injury mechanism, ATSF type, magnetic resonance imaging (MRI) evaluation, treatment modality, ACL injury, and concomitant meniscal/chondral injuries were analyzed. Concurrent ACL injury was confirmed either from MRI or intraoperatively. Results Nineteen percent (n=25) of ATSF patients had concomitant ACL injury, with ACL injury significantly more likely in type II or type III ATSF compared with type I ATSF (P=0.03). Patients with combined ATSF/ACL injury were significantly older (P=0.02) and more likely to be male (P=0.01). Mechanism of ATSF injury was not associated with ACL injury (P=0.83). Preoperative MRI had low sensitivity (0.09) for recognizing ACL injury at the time of ATSF relative to intraoperative assessment. Half of ATSF/ACL-injured patients had additional meniscal or chondral injury, with meniscal repair or debridement required in 37.5% of the type II ATSF/ACL injury. Conclusions There are demographic characteristics, such as age (older) and sex (male), associated with a higher risk of concomitant ACL injury at the time of ATSF. Type II and type III ATSF patterns had a higher prevalence of ACL injury. MRI failed to correctly identify ACL injury at the time of ATSF. Concomitant ACL injury at the time of ATSF is highly prevalent in the skeletally immature, occurring in 19.4% of patients with ATSF. Level of evidence Level IV-case series.

Purpose The purpose of this systematic review was to examine the effect that sex has on recurrence of anterior shoulder instability following primary arthroscopic anterior shoulder stabilization. Methods A systematic review using PRISMA guidelines was performed by searching PubMed, Embase and Cochrane Library databases to identify studies reporting recurrence rates following arthroscopic anterior shoulder stabilization with a minimum follow-up period of 2 years. Patient demographics as well as preoperative, intraoperative and postoperative findings, including patient-reported outcomes and recurrence rates, were analyzed by 2 independent reviewers. Recurrence was defined as an episode of dislocation, subluxation or instability following primary arthroscopic anterior shoulder stabilization. Study methodological quality was evaluated with the Modified Coleman Methodology Score (MCMS). Risk bias was evaluated using the Methodological Index for Non-randomized Studies (MINORS score). Descriptive statistics are presented. Results Ten studies (1 Level I, 1 Level II, 5 Level III, and 3 Level IV), including a total of 7,102 patients with primary traumatic and/or recurrent traumatic shoulder instability without previous procedures who underwent primary arthroscopic anterior shoulder stabilization, were included (mean follow-up, 34.6 months; mean age, 25.4 years). There was a total of 5,097 males (71.8%) and 2,005 females (28.2%). There was a higher recurrence rate in males (6%-37%) compared to females (0-32%). Clinical outcomes were inconsistently reported, so no quantitative analysis of clinical outcomes or return-to-sport between sexes was possible. The average MCMS of all 10 studies was 76.8 ± 8.0, indicating good methodology. Conclusions Males may have higher recurrence rates than females following primary arthroscopic anterior shoulder stabilization; however, the heterogeneity of the included studies precludes any definitive conclusions. Level of evidence IV, Systematic Review of Level I-IV.

BackgroundPatient-reported outcomes (PROs) are a valid measure of results after revision anterior cruciate ligament (ACL) reconstruction. Revision ACL reconstruction has been documented to have worse outcomes when compared with primary ACL reconstruction. Understanding positive and negative predictors of PROs will allow surgeons to modify and potentially improve outcome for patients.Purpose/hypothesisThe purpose was to describe PROs after revision ACL reconstruction and test the hypothesis that patient- and technique-specific variables are associated with these outcomes.Study designCohort study; Level of evidence, 2.MethodsPatients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons over 52 sites. Data included baseline demographics, surgical technique and pathology, and a series of validated PRO instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale. Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Multivariate regression models were used to control for a variety of demographic and surgical factors to determine the positive and negative predictors of PRO scores at 2 years after revision surgery.ResultsA total of 1205 patients met the inclusion criteria and were successfully enrolled: 697 (58%) were male, with a median cohort age of 26 years. The median time since their most recent previous ACL reconstruction was 3.4 years. Two-year questionnaire follow-up was obtained from 989 patients (82%). The most significant positive predictors of 2-year IKDC scores were a high baseline IKDC score, high baseline Marx activity level, male sex, and having a longer time since the most recent previous ACL reconstruction, while negative predictors included having a lateral meniscectomy before the revision ACL reconstruction or having grade 3/4 chondrosis in either the trochlear groove or the medial tibial plateau at the time of the revision surgery. For KOOS, having a high baseline score and having a longer time between the most recent previous ACL reconstruction and revision surgery were significant positive predictors for having a better (ie, higher) 2-year KOOS, while having a lateral meniscectomy before the revision ACL reconstruction was a consistent predictor for having a significantly worse (ie, lower) 2-year KOOS. Statistically significant positive predictors for 2-year Marx activity levels included higher baseline Marx activity levels, younger age, male sex, and being a nonsmoker. Negative 2-year activity level predictors included having an allograft or a biologic enhancement at the time of revision surgery.ConclusionPROs after revision ACL reconstruction are associated with a variety of patient- and surgeon-related variables. Understanding positive and negative predictors of PROs will allow surgeons to guide patient expectations as well as potentially improve outcomes.

BACKGROUND: Patient reported outcomes (PROs) are a valid measure of results following revision anterior cruciate ligament (ACL) reconstruction. Revision ACL reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. Understanding positive and negative predictors of PROs will allow surgeons to modify and potentially improve outcome for these patients. HYPOTHESIS/PURPOSE: The purpose of this study was to describe PROs following revision ACL reconstruction and test the hypothesis that patient and technique specific variables are associated with these outcomes. STUDY DESIGN: Cohort study METHODS: Revision ACL reconstruction patients were identified and prospectively enrolled by 83 surgeons over 52 sites. Data collected included baseline demographics, surgical technique and pathology, and a series of validated PRO instruments (IKDC, KOOS, WOMAC and Marx activity rating score). Patients were followed up at 2 years, and asked to complete the identical set of outcome instruments. Multivariate regression models were used to control for a variety of demographic and surgical factors, in order to determine both the positive and negative predictors of PRO scores at 2 years following revision surgery. RESULTS: 1205 patients met the inclusion criteria and were successfully enrolled. 697 (58%) were males, with a median cohort age of 26 years. The median time since their last ACL reconstruction was 3.4 years. Two-year questionnaire follow-up was obtained on 989 subjects (82%). The most significant positive predictors of 2-year IKDC scores were a high baseline IKDC score, high baseline Marx activity level, male gender, and having a longer time between a patient’s last ACL reconstruction, while negative predictors included having a previous lateral meniscectomy prior to the revision ACL reconstruction or having Grades 3/4 chondrosis in either the trochlear groove or medial tibial plateau at the time of the revision surgery. For KOOS, having a high baseline score and having a longer time between their last ACL reconstruction and revision surgery were significant positive predictors for having better (i.e. higher) 2-year KOOS scores, while having a previous lateral meniscectomy prior to the revision ACL reconstruction was a consistent predictor for having significantly worse (i.e. lower) 2-year KOOS scores. Statistically significant positive predictors for 2-year Marx activity levels included higher baseline Marx activity levels, younger age, male gender, and being a non-smoker. Negative 2-year activity level predictors included having an allograft or a biologic enhancement at the time of revision surgery. CONCLUSIONS: PROs following revision ACL reconstruction are associated with a variety of patient and surgeon related variables. Understanding positive and negative predictors of PROs will allow surgeons to guide patient expectation as well as potentially improve outcome for these patients.

Background: Injuries to the posterolateral corner (PLC) may occur concurrently with anterior cruciate ligament (ACL) injury. Purpose/Hypothesis: This study evaluated the outcomes of patients who underwent operative management of PLC injuries concurrently with ACL reconstruction in a prospective multicenter cohort. We hypothesized that there would be no differences in outcomes between patients who were treated with PLC repair and PLC reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing ACL reconstruction were enrolled into a prospective longitudinal multicenter cohort between 2002 and 2008. Those with complete 6-year follow-up data (patient-reported outcomes and subsequent surgery information) were identified. Excluded from the study were patients with posterior cruciate ligament injuries. Patients who underwent PLC repair were compared with those who underwent PLC reconstruction with regard to interval from injury to surgery, need for revision surgery, and long-term outcomes at 6 years. Results: During the identified time frame, 3026 identified patients underwent primary ACL reconstruction; 34 (1.1%) also underwent concurrent PLC surgery (15 repairs, 19 reconstructions [18 allografts, 1 autograft]). With the numbers available, we did not detect significant differences between groups regarding the rate of meniscal or chondral injuries. Median time to PLC reconstruction was 121 days as compared with 19 days for concurrent ACL reconstruction and PLC repair ( P = .01). There were no between-group differences in Marx activity scores prior to surgery ( P = .4). At 6-year follow-up, there were no between-group differences in Knee injury and Osteoarthritis Outcome Score ( P = .36-.83) or International Knee Documentation Committee score ( P = .84); however, patients treated with PLC reconstructions had lower Marx activity scores (4.1 vs 9.4; P = .02). There was 1 ACL revision in the PLC reconstruction group, and 1 of the PLC repairs was revised to a reconstruction during the follow-up period. Conclusion: Good outcomes were achieved at 6-year follow-up with both repair and reconstruction of PLC injuries treated concurrently with ACL reconstruction. The PLC reconstruction group had lower activity levels 6 years after surgery. The present data suggest that, for appropriately selected patients undergoing acute surgical treatment of combined ACL and PLC injuries, PCL repair can achieve good long-term outcomes.

BackgroundAnterior cruciate ligament (ACL) revision cohorts continually report lower outcome scores on validated knee questionnaires than primary ACL cohorts at similar time points after surgery. It is unclear how these outcomes are associated with physical activity after physician clearance for return to recreational or competitive sports after ACL revision surgery.HypothesesParticipants who return to either multiple sports or a singular sport after revision ACL surgery will report decreased knee symptoms, increased activity level, and improved knee function as measured by validated patient-reported outcome measures (PROMs) and compared with no sports participation. Multisport participation as compared with singular sport participation will result in similar increased PROMs and activity level.Study designCross-sectional study; Level of evidence, 3.MethodsA total of 1205 patients who underwent revision ACL reconstruction were enrolled by 83 surgeons at 52 clinical sites. At the time of revision, baseline data collected included the following: demographics, surgical characteristics, previous knee treatment and PROMs, the International Knee Documentation Committee (IKDC) questionnaire, Marx activity score, Knee injury and Osteoarthritis Outcome Score (KOOS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). A series of multivariate regression models were used to evaluate the association of IKDC, KOOS, WOMAC, and Marx Activity Rating Scale scores at 2 years after revision surgery by sports participation category, controlling for known significant covariates.ResultsTwo-year follow-up was obtained on 82% (986 of 1205) of the original cohort. Patients who reported not participating in sports after revision surgery had lower median PROMs both at baseline and at 2 years as compared with patients who participated in either a single sport or multiple sports. Significant differences were found in the change of scores among groups on the IKDC (P < .0001), KOOS-Symptoms (P = .01), KOOS-Sports and Recreation (P = .04), and KOOS-Quality of Life (P < .0001). Patients with no sports participation were 2.0 to 5.7 times more likely than multiple-sport participants to report significantly lower PROMs, depending on the specific outcome measure assessed, and 1.8 to 3.8 times more likely than single-sport participants (except for WOMAC-Stiffness, P = .18), after controlling for known covariates.ConclusionParticipation in either a single sport or multiple sports in the 2 years after ACL revision surgery was found to be significantly associated with higher PROMs across multiple validated self-reported assessment tools. During follow-up appointments, surgeons should continue to expect that patients who report returning to physical activity after surgery will self-report better functional outcomes, regardless of baseline activity levels.

Several thermal processes were tested to inactivate foot-and-mouth disease virus in beef miniburgers using a dry oven to grill and a steam oven to finish the cooking. A satisfactory product free of foot-and-mouth disease virus was obtained by grilling the contaminated miniburgers in the dry oven for 299 s at 208°C, followed by steam cooking in the moist oven for 190 s with a minimum average exit temperature of 99.4°C. It was found that a temperature indicator device is a reliable tool to verify the thermal process.

Background:Recent studies have described surgical techniques to increase the hamstring graft diameter for anterior cruciate ligament reconstruction (ACLR), particularly for 5-strand hamstring (5HS) autografts.Purpose:To review the literature examining the biomechanical and clinical outcomes of 5HS autografts for ACLR.Study Design:Systematic review; Level of evidence, 3.Methods:A systematic review using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines was performed by searching PubMed, Embase, and the Cochrane Library for studies reporting the biomechanical and clinical outcomes of 5HS autografts. All English-language literature published from 2012 to 2018 that reported the biomechanical properties of 5HS grafts and/or clinical outcomes after ACLR with 5HS autografts with a minimum 1-year follow-up was reviewed by 2 independent reviewers. Graft diameter, stiffness, displacement, strength, failure rates, anteroposterior knee laxity, and patient-reported outcome scores were collected. The study methodology was evaluated using the modified Coleman Methodology Score.Results:Two biomechanical and 3 clinical studies (1 with level 2 evidence, 2 with level 3 evidence) were included. The biomechanical studies compared the results of fourteen 4-strand hamstring (4HS) and fourteen 5HS graft specimens for ACLR (ovine grafts, n = 12; cadaveric grafts, n = 16) and found no significant differences in ultimate load, stiffness, displacement, and stress relaxation ( P > .05), likely attributed to insufficient incorporation of the fifth strand. The mean 5HS cadaveric graft diameter (8.2 mm) was significantly greater than that of 4HS grafts (6.8 mm) ( P = .002), whereas the mean ovine graft diameters were not significantly different (4HS, 5.2 mm; 5HS, 5.3 mm) ( P > .05). Two clinical studies compared the outcomes after ACLR of 53 patients with a 4HS autograft versus 62 patients with a 5HS autograft, while 1 clinical study reported the outcomes of 25 patients after ACLR with a 5HS autograft (mean age, 28.7 years; mean follow-up, 24.8 months). The overall mean diameter for 4HS and 5HS autografts was 8.4 and 9.1 mm, respectively. There was no significant difference in failure rates between 4HS and 5HS autografts ( P = .82). None of the comparative studies reported significant differences in any clinical outcomes ( P > .05 for all).Conclusion:The available literature on traditional 4HS and 5HS autografts for ACLR is limited. Of the available data, clinical and biomechanical studies suggest no difference in outcomes after ACLR with either graft construct. Additional research is needed to determine whether creating a 5HS graft is beneficial.

Background: Arthroscopic posterior shoulder stabilization can be performed with patients in the beach-chair (BC) and the lateral decubitus (LD) positions; however, the impact of patient positioning on clinical outcomes has not been evaluated. Purpose: To compare clinical outcomes and recurrence rates after arthroscopic posterior shoulder stabilization performed in the BC and LD positions. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines was performed by searching PubMed, Embase, and the Cochrane Library for studies reporting the clinical outcomes of patients undergoing arthroscopic posterior shoulder stabilization in either the BC or LD position. All English-language studies from 1990 to 2017 reporting clinical outcomes after arthroscopic posterior shoulder stabilization with a minimum 2-year follow-up were reviewed by 2 independent reviewers. Data on the recurrent instability rate, return to activity or sport, range of motion, and patient-reported outcome scores were collected. Study methodological quality was evaluated using the Modified Coleman Methodology Score (MCMS) and Quality Appraisal Tool (QAT). Results: A total of 15 studies (11 LD, 4 BC) with 731 shoulders met the inclusion criteria, including 626 shoulders in the LD position (mean patient age, 23.9 ± 4.1 years; mean follow-up, 37.5 ± 10.0 months) and 105 shoulders in the BC position (mean patient age, 27.8 ± 2.2 years; mean follow-up, 37.9 ± 16.6 months). There was no significant difference in the overall mean recurrent instability rate between the LD and BC groups (4.9% ± 3.6% vs 4.4% ± 5.1%, respectively; P = .83), with similar results in a subanalysis of studies utilizing only suture anchor fixation (4.9% ± 3.6% vs 3.2% ± 5.6%, respectively; P = .54). There was no significant difference in the return-to-sport rate between the BC and LD groups (96.2% ± 5.4% vs 88.6% ± 9.1%, respectively; P = .30). Range of motion and other patient-reported outcome scores were not provided consistently across studies to allow for statistical comparisons. Conclusion: Low rates of recurrent shoulder instability and high rates of return to sport can be achieved after arthroscopic posterior shoulder stabilization in either the LD or the BC position. Additional long-term randomized trials comparing these positions are needed to better understand the potential advantages and disadvantages of surgical positioning for posterior shoulder stabilization.

Supplemental material, DS_10.1177_0363546519856348 for Relationship Between Sports Participation After Revision Anterior Cruciate Ligament Reconstruction and 2-Year Patient-Reported Outcome Measures in The American Journal of Sports Medicine

Osteochondral autograft transfer (OATS) is a one-stage surgical procedure to treat chondral defects of the knee and other articulating surfaces. Optimal treatment for symptomatic knee lesions remains controversial. Osteochondral autograft transfer is one of several approaches to cartilage repair. Other techniques include marrow stimulation, cell-based strategies, and allograft transplantation. 1 The advantages of OATS include the use of autologous tissue, which avoids the potential risks and costs associated with allograft transplantation, as well as the use of a structural graft with both bone and cartilage. This may be advantageous over marrow stimulation or cellular treatments, which only address the chondral component to the pathology. The disadvantage of OATS is that it cannot be used to treat very large lesions, as there is not enough healthy donor tissue in the knee to account for large lesions. Of note, OATS is an acronym often used for both autograft and allograft osteochondral transplantation, which can be confusing. OATS does refer to osteochondral autograft transplantation, and for the purposes of this manuscript, should not be considered synonymous with allograft transplantation.

The importance of emotional and psychological factors in treatment of patients with rotator cuff disease has been recently emphasized. Our goal was to establish factors most predictive of poor emotional health in patients with full-thickness rotator cuff tears (FTRCTs).In 2007, we began to prospectively collect data on patients with symptomatic, atraumatic FTRCTs. All patients completed a questionnaire collecting data on demographics, symptom characteristics, comorbidities, willingness to undergo surgery, and patient-related outcomes (12-Item Short Form Health Survey, American Shoulder and Elbow Surgeons score, Western Ontario Rotator Cuff Index [WORC], Single Assessment Numeric Evaluation score, Shoulder Activity Scale). Physicians recorded physical examination and imaging data. To evaluate the predictors of lower WORC emotion scores, a linear multiple regression model was fit.Baseline data for 452 patients were used for analysis. In patients with symptomatic FTRCTs, the factors most predictive of worse WORC emotion scores were higher levels of pain (interquartile range odds ratio, -18.9; 95% confidence interval, -20.2 to -11.6; P .0001) and lower Single Assessment Numeric Evaluation scores (rating of percentage normal that patients perceive their shoulder to be; interquartile range odds ratio, 6.2; 95% confidence interval, 2.5-9.95; P = .0012). Higher education (P = .006) and unemployment status (P = .0025) were associated with higher WORC emotion scores.Education level, employment status, pain levels, and patient perception of percentage of shoulder normalcy were most predictive of emotional health in patients with FTRCTs. Structural data, such astendon tear size, were not. Those with poor emotional health may perceive their shoulder to be worse than others and experience more pain. This may allow us to better optimize patient outcomes with nonoperative and operative treatment of rotator cuff tears.

Background:Avulsion fractures of the anterior tibial spine in young athletes are injuries similar to anterior cruciate ligament (ACL) injuries in adults. Sparse data exist on the association between anterior tibial spine fractures (ATSFs) and later ligamentous laxity or injuries leading to ACL reconstruction.Purpose:To better delineate the incidence of delayed instability or ACL ruptures requiring delayed ACL reconstruction in young patients with prior fractures of the tibial eminence.Study Design:Case series; Level of evidence, 4.Methods:We identified 101 patients between January 1993 and January 2012 who sustained an ATSF and who met inclusion criteria for this study. All patients had been followed for at least 2 years after the initial injury and were included for analysis after completion of a questionnaire via direct contact, mail, and/or telephone. If patients underwent further surgical intervention and/or underwent later ACL reconstruction, clinical records and operative reports pertaining to these secondary interventions were obtained and reviewed. Differences between categorical variables were assessed using the Fisher exact test. The association between time to revision ACL surgery and fracture type was assessed by Kaplan-Meier plots. The association between need for revision ACL surgery and age, sex, and mechanism of surgery was assessed using logistic regression.Results:Nineteen percent of all patients evaluated underwent delayed ACL reconstruction after a previous tibial spine fracture on the ipsilateral side. While there were a higher proportion of ACL reconstructions in type II fractures, there was not a statistically significant difference in the number of patients within each fracture group who went on to undergo later surgery ( P = .29). Further, there was not a significant association between fracture type, sex, or mechanism of injury as it related to the progression to later ACL reconstruction. However, there was a significant association between age at the time of injury and progression to later ACL reconstruction ( P = .02). For every year increase in age at the time of injury, the odds of going on to undergo delayed ACL reconstruction were greater by a factor of 1.3 (95% CI, 1.1-1.6).Conclusion:Although an ATSF is a relatively rare injury, our cohort of patients suggests that a subset of young patients with all types of tibial spine fractures will require later ACL reconstruction. There is a need to counsel patients that a delayed ACL rupture is a potential risk after an ATSF, especially as children approach skeletal maturity. Further patient follow-up and prospective studies are required.

In this paper we study discrete-time Markov decision processes in Borel spaces with a finite number of constraints and with unbounded rewards and costs. Our aim is to provide a simple method to compute constrained optimal control policies when the payoff functions and the constraints are of either: infinite-horizon discounted type and average (a.k.a. ergodic) type. To deduce optimality results for the discounted case, we use the Lagrange multipliers method that rewrites the original problem (with constraints) into a parametric family of discounted unconstrained problems. Based on the dynamic programming technique as long with a simple use of elementary differential calculus, we obtain both suitable Lagrange multipliers and a family of control policies associated to these multipliers, this last family becomes optimal for the original problem with constraints. We next apply the vanishing discount factor method in order to obtain, in a straightforward way, optimal control policies associated to the average problem with constraints. Finally, to illustrate our results, we provide a simple application to linear–quadratic systems (LQ-systems).

Purpose To determine which patient and injury factors are associated with the detection of high-grade laxity on examination under anesthesia before anterior cruciate ligament (ACL) reconstruction. Methods We identified 2,318 patients who underwent primary ACL reconstruction without associated ligament injuries. Demographic data and information regarding meniscal tears were collected. Patients with high-grade Lachman (difference from contralateral side >10 mm), pivot-shift (International Knee Documentation Committee grade 3+), or anterior drawer (difference from contralateral side >10 mm) tests were identified by physical examination under anesthesia before ACL reconstruction. Logistic regression modeling was used to evaluate whether chronicity of the ACL injury, patient age, sex, body mass index, generalized ligamentous laxity, and presence of meniscal tears were associated with increased odds of high-grade laxity, while we controlled for examining surgeon. Results Patients with chronic tears (>6 months from injury) had greater than twice the odds of having high-grade Lachman, pivot-shift, and anterior drawer tests (all P P P P = .013) meniscus tears were associated with increased odds of a high-grade Lachman test. Age younger than 20 years (OR, 1.34; P = .023), female sex (OR, 1.49; P = .001), generalized ligamentous laxity (OR, 3.46; P P P = .041) meniscus tear were associated with increased odds of a high-grade pivot-shift test. Generalized ligamentous laxity (OR, 2.27; P P = .001) or lateral (OR, 1.50; P = .010) meniscus tear were associated with increased odds of a high-grade anterior drawer test. Conclusions Chronic ACL tears, generalized ligamentous laxity, and meniscus tears are associated with increased odds of high-grade laxity with all 3 tests. Female patients and age younger than 20 years are associated with increased odds of a high-grade pivot-shift test. Level of Evidence Level II, lesser-quality prospective study.

Background:Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions.Purpose/Hypothesis:The purpose of this study was to determine if the prevalence, location, and/or degree of meniscal and chondral damage noted at the time of revision ACL reconstruction predicts activity level, sports function, and osteoarthritis symptoms at 2-year follow-up. The hypothesis was that meniscal loss and high-grade chondral damage noted at the time of revision ACL reconstruction will result in lower activity levels, decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery.Study Design:Cohort study; Level of evidence, 2.Methods:Between 2006 and 2011, a total of 1205 patients who underwent revision ACL reconstruction by 83 surgeons at 52 hospitals were accumulated for study of the relationship of meniscal and articular cartilage damage to outcome. Baseline demographic and intraoperative data, including the International Knee Documentation Committee (IKDC) subjective knee evaluation, Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx activity score, were collected initially and at 2-year follow-up to test the hypothesis. Regression analysis was used to control for age, sex, body mass index, smoking status, activity level, baseline outcome scores, revision number, time since last ACL reconstruction, incidence of having a previous ACL reconstruction on the contralateral knee, previous and current meniscal and articular cartilage injury, graft choice, and surgeon years of experience to assess the meniscal and articular cartilage risk factors for clinical outcomes 2 years after revision ACL reconstruction.Results:At 2-year follow-up, 82% (989/1205) of the patients returned their questionnaires. It was found that previous meniscal injury and current articular cartilage damage were associated with the poorest outcomes, with prior lateral meniscectomy and current grade 3 to 4 trochlear articular cartilage changes having the worst outcome scores. Activity levels at 2 years were not affected by meniscal or articular cartilage pathologic changes.Conclusion:Prior lateral meniscectomy and current grade 3 to 4 changes of the trochlea were associated with worse outcomes in terms of decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery, but they had no effect on activity levels.Registration:NCT00625885

In this paper we introduce two useful methods to compute optimal control policies for either the discounted or the average payoff criterion with cost constraints when the dynamic system evolves as a n -dimensional diffusion processes. As for the attribute “cost constraints” we mean the coexistence of a given cost function that in general is dominated above by another function (in particular by a constant) playing the role of an extra constraint in the control model. To deduce optimality results for the discounted case, we employ the Lagrange multipliers technique along with dynamic programming arguments. Then, the vanishing discount method is applied to easily obtain average optimal policies. We support our theory by providing an example on pollution accumulation problem.

Objectives: To evaluate the accuracy of correction angle of an all-PEEK medial opening wedge high tibial osteotomy (HTO) system, as well as determine the effect of correction angle on postoperative complications. Methods: Retrospective review was performed on patients who underwent an HTO by the senior author using an all-PEEK HTO system between 2014-2018 with a >6-month follow-up were included. Measurements were performed and classifications formulated by three senior residents and the senior author. Lateral hinge fractures (LHF) were classified according to Takeuchi classification system. Bivariate statistics were performed. Results: Thirty HTOs in 27 patients were included (50% female; age, 37.8±10.8 years). Average follow-up was 16.2±10.1 months. Average post-operative radiographic valgus correction (Δ, 5.8±2.4°) was significantly less than that of the average implant correction angle (8.1±2.3°; p5° loss of planned correction) that shared a common mechanism of medial cortical failure inferior to the implant. When selecting out the construct failures, the average correction accuracy of the 25 (83.3%) non-failures (1.5±1.2°) was significantly better than the 5 (16.7%) failures (6.3±1.8°; p=0.002). Four fractures (13.3%) were identified: 3 (10%) Takeuchi type I and 1 (3.3%) type III. All type I fractures were associated with >5° planned correction loss with medial cortex buckling. Overall, 9 knees (30%) experienced minor complications: neuropathy (n=1; 3.3%), deep vein thrombosis (n=2; 6.7%), and superficial infection (n=3; 10%). Conclusion: The use of an all-PEEK medial opening wedge HTO implant is a safe and effective system, with an acceptable average under-correction of 1.5° in patients not sustaining medial cortex failure. Loss of correction was associated with medial cortex failure and Takeuchi type I LHF. This is the first description of this failure mechanism (medial cortex buckling) that is specific to this implant and technique.