Search

Objectives: To develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect the most valuable variables associated with failure. Methods: A single institution prospectively collected database of cartilage procedures was queried for procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery and/or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. The dataset was randomly divided into training (70%) and independent testing (30%) sets. Four machine learning algorithms were trained and internally validated. Algorithm performance was assessed using area under curve (AUC) and the Brier score. Local Interpretable Model-agnostic Explanations (LIME) was utilized to assess the optimized algorithm fidelity. Results: A total of 1091 patients who underwent surgical procedures addressing cartilage defects in the knee with a minimum of 2-years of follow-up were included. The mean follow-up was 3.5 ± 2.8 years. The mean age was 40.5 ± 15 years. There were 205 (18.8%) patients who failed at final follow-up. The Random Forest algorithm was found to be the best performing algorithm, with an AUC of 0.765 and a Brier score of 0.135. The 10 most important features for predicting failure following surgical procedures addressing cartilage defects of the knee were: symptom duration, age, body mass index (BMI), lesion grade, total lesion area (sum of all lesion areas), number of previous surgeries, number of lesions in the knee, gender, athletic level, and traumatic etiology. LIME analysis allowed for assessment of the optimized algorithm fidelity, as well as provided a patient-specific comparison for the risk of failure of an individual patient being assigned various types of cartilage procedures. Conclusions: Machine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features being symptom duration, age, BMI, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee. Integrated human and machine learning decision-making may improve patient selection and bring about the new era of patient-tailored evidence-based clinical care. [ABSTRACT FROM AUTHOR]

Objectives: Ulnar collateral ligament reconstruction (UCL-R) surgeries have increased significantly in amateur and professional baseball pitchers. While high school (HS) showcase participation has been considered an injury risk factor, limited data corroborating this association exists. Despite concern that showcase participation in amateur athletes may lead to higher risk of future injury, there is a scarcity of UCL injury-specific research on elite amateur pitchers using reliably recorded pitch velocity and other performance data rather than self-reported metrics. The objectives of this study were to examine the age at which elite high school pitchers began to achieve high fastball velocity, specifically greater than 90, 92, and 95 mph (≥90/92/95 mph), as well as to examine the relationship between showcase participation and future need for UCL-R during their professional career. We hypothesize that pitchers achieving fastball velocities ≥90/92/95 mph at younger ages are more likely to undergo UCL-R earlier in their professional careers compared to pitchers not achieving these velocity thresholds. Additionally, we hypothesize that pitchers participating in high showcase volumes are more likely to undergo UCL-R compared to pitchers participating in fewer showcases. Methods: Demographic, HS showcase performance, and injury data from pitchers selected in the first 5 rounds of the Major League Baseball (MLB) Draft (2011-2020) were gathered from publicly available databases. Demographic data collected for each pitcher included date of birth, height/weight/body mass index at time of MLB Draft, position (left- vs. right-handed pitcher), MLB Draft year, MLB Draft round and overall pick, high school state/country, college (if attended), whether pitcher entered professional baseball directly after HS, U.S. region, MLB organization which drafted pitcher. Performance data were collected for each pitcher exclusively from PG (www.perfectgame.org) and PBR (www.prepbaseballreport.com) events participated in during their HS careers prior to MLB draft. Performance metrics included: peak fastball velocity at HS showcases, age at which a pitcher achieved ≥90/92/95 mph at a HS showcase, age at which slider was first thrown in a HS showcase, peak slider velocity in a HS showcase. UCL injury data included: age at UCL-R, specific amateur or professional level when injured, and recovery time (in months). Continuous and categorical variables for pitchers undergoing UCL-R and those not undergoing UCL-R were compared, and multivariable analysis was performed using logistic regression. Standard deviations of ±1 SD were used to define "early" versus "late" UCL-R subgroups after normal distribution was confirmed (Shapiro-Wilk test, p = 0.183). Trends in time were evaluated using linear regression. The significance of trends over time was evaluated using linear regression. Data analysis was performed using SPSS Version 27 (IBM Corp). A two-tailed P<0.05 was used for determining statistical significance. Results: There were 845 pitchers selected in the first five rounds of the MLB Draft in the 10-year period selected for this study (2011-20). Overall, 659 of 845 pitchers (78.0%) had retrievable showcase performance data. Of 845 pitchers, 229 (27.1%) underwent UCL-R. Peak fastball velocity recorded at showcases was the strongest predictor of UCL-R (adjusted odds ratio 1.19, 95% CI 1.02, 1.39; p = 0.03) (Figure 1). Peak fastball velocity in high school (HS) was significantly higher among pitchers who underwent UCL-R compared the no UCL-R group (91.57 vs. 90.71 mph, 95% CI -1.43, -0.29; p < 0.01). Pitchers who achieved a peak fastball velocity of ≥ 90 mph in HS were more likely to undergo UCL-R compared to those who did not (p = 0.03). Similarly, pitchers who achieved a peak fastball velocity of ≥ 92 mph in HS were more likely to undergo UCL-R compared to pitchers who did not (p < 0.01). Age at which pitchers participated in their first HS showcase was significantly younger for the "early" versus the "late" UCL-R group (15.53 vs. 16.51 years, 95% CI -1.53, -0.41; p < 0.01). Elite pitchers with "early" UCL-R participated in more showcases compared to the "late" UCL-R group (5.38 vs. 2.89, 95% CI 0.48, 4.50; p = 0.02) (Figure 2). Upon multivariable analysis, peak fastball velocity in HS and a peak fastball velocity of ≥95 mph in HS were primary independent predictors of undergoing UCL-R. The likelihood of undergoing UCL-R increased 19% for every unit (mph) increase in peak fastball velocity at HS showcases (aOR 1.19, 95% CI 1.02, 1.39; p = 0.03). Between 2011-2022, significant trends were identified among pitchers chosen in the first five rounds of the MLB Draft (Figure 3). Mean age at which a pitcher underwent UCL-R decreased steadily over the decade by over 3.5 years (23.85 vs. 20.29 years, p < 0.001). Mean age at which a pitcher attended his first HS showcase steadily declined as well over the ten-year period (16.53 vs. 15.63 years, p < 0.001). Mean number of HS showcases a pitcher attended more than doubled during the decade (2.88 vs. 6.00 total showcases, p < 0.001). Additionally, mean age at which a pitcher achieved ≥90 mph fastball in a HS showcase also declined (17.19 vs. 16.71 years, p < 0.01). Conclusions: Peak fastball velocity recorded at HS showcase events is the strongest predictor of UCL-R in elite pitchers. Achieving fastball velocity thresholds of ≥90 mph and ≥92 mph at HS showcase events significantly increased the likelihood of UCL-R in elite pitchers. Younger age at first HS showcase, and younger age achieving ≥90 mph in a HS showcase significantly increased the likelihood of early UCL-R compared to late UCL-R in this cohort. Overall, our study findings provide statistically significant results which support a formal recommendation to limit showcase participation in adolescent and HS pitchers to age 16 years and older. [ABSTRACT FROM AUTHOR]

Objectives: Osteochondritis dissecans (OCD) of the humeral capitellum is an often painful condition that typically affects the adolescent athlete. There is little consensus on treatment and a scarcity of long-term outcomes data. The purpose of this study was to (1) report the long-term outcomes associated with both operative and non-operative management of capitellar OCD, (2) identify factors associated with failure of non-operative management, and (3) determine whether delay in surgery affects final outcomes. Methods: All patients diagnosed with OCD of the capitellum from 1995-2020 within a defined geographic cohort were included. Medical records, imaging studies, and operative reports were manually reviewed to record demographic data, treatment strategies, and outcomes. Surgical treatment was considered delayed if it occurred more than 6 months after symptom onset. Results: A total of 50 elbows with a mean follow-up of 9.4 years were included. Of these, 7 (14%) were treated non-operatively and never underwent surgery during follow-up, while 43 (86%) underwent surgical intervention: 27 had early surgery and 16 underwent delayed surgery after ≥ 6 months of non-operative treatment. When compared to non-operative management, surgical management resulted in superior MEPI scores (90 vs 83, p=0.05), decreased persistence of mechanical symptoms (9% vs 50%, p<0.01), and better elbow flexion (141° vs 131°, p=0.01) at long-term follow up. Older patients had a trend toward increased failure of non-operative management (p=0.06). The presence of an intra-articular loose body strongly predicted failure of non-operative management (p=0.01; OR 13). Plain radiography and MRI had poor sensitivities for identifying loose bodies (27% and 40%, respectively). Differences in outcomes following early versus delayed surgical management were not demonstrated. Conclusions: Patients with capitellar OCD initially treated nonoperatively failed nonoperative management 70% of the time. Elbows that did not undergo surgery had slightly increased symptoms and decreased functional outcomes compared to those treated surgically. In this cohort, the greatest predictors for failure of non-operative treatment were older age and presence of a loose body; however, an initial trial of non-operative treatment did not adversely impact the success of future surgery at long term follow-up. [ABSTRACT FROM AUTHOR]

Objectives: Despite successful return to sport (RTS) outcomes after posteromedial osteophyte resection, one possible consequence of removing this osteophyte is increased stress on the ulnar collateral ligament (UCL), leading to a UCL injury. It is currently unknown how often overhead athletes who have an isolated posteromedial osteophyte resection progress to require UCL reconstruction (UCLR). Therefore, the purpose of this study was to report outcomes following arthroscopic resection of posteromedial osteophyte in overhead athletes and determine if baseball pitchers who underwent arthroscopic posteromedial osteophyte resection for posteromedial impingement went on to require UCL surgery. Methods: All patients who underwent elbow arthroscopy from 2010-2020 were reviewed. Patients were included if they underwent isolated arthroscopic posteromedial osteophyte resection without concomitant UCL surgery, were overhead athletes at the onset of posteromedial impingement symptoms and had no history of prior elbow surgery. Primary outcomes included RTS rate, complications, subsequent shoulder and elbow injury/surgery and several patient-reported outcome measures (Kerlan-Jobe Orthopaedic Clinic score, Timmerman-Andrews Elbow score, Conway-Jobe score). Results: Overall, 36 overhead athletes were evaluated at 5.1 years post-operatively, including 28 baseball pitchers, 3 baseball catchers, 3 softball players, 1 tennis player, and 1 volleyball player. 77% of overhead athletes RTS and had a mean KJOC score of 70, with 89% of athletes having either an excellent (73%) or good (16%) Conway-Jobe score at long-term follow-up. Subsequent UCLR was required in 18% (n=5) of baseball pitchers at a median of 13 months post-op. Three of the five UCLR were performed shortly after posteromedial osteophyte resection (6, 7, and 13 months post-op), while the other two UCLRs were performed at 6.2 and 7.5 years post-op. Conclusions: Following arthroscopic posteromedial osteophyte resection, 77% of athletes were able to RTS. Baseball pitchers who undergo arthroscopic posteromedial osteophyte resection have an 18% risk of subsequent UCLR. [ABSTRACT FROM AUTHOR]

Objectives: Suprascapular neuropathy due to nerve compression or tension at the suprascapular notch is an uncommon source of shoulder pain and rotator cuff weakness with recent increased recognition and treatment. Long considered an elusive diagnosis, work-up can be lengthy and patients may experience treatment delay. We aimed to review presentation patterns and outcomes of arthroscopic suprascapular nerve decompression in a predominantly young and active military population. Methods: The surgical databases of two surgeons were queried for patients treated with arthroscopic suprascapular nerve decompression at the suprascapular notch from 2013 to 2021. Patient data, presentation and workup findings, and outcome measures were collected through review of the electronic medical record. Primary outcome measures were rate of return to active-duty military service, shoulder abduction and external rotation strength, and VAS pain scores. Secondary outcome measures were American Shoulder and Elbow Surgeons (ASES) Shoulder Score, Visual Analogue Scale (VAS), and Single Assessment Numerical Evaluation (SANE) score. Results: Twenty-five patients were identified. Average age was 26.6 years and follow-up 17.9 months (4-62 months). There were two distinct primary presentation types in this cohort: the chief complaint was pain in 13 patients (52%) and weakness in 12 (48%). Supraspinatus and/or infraspinatus atrophy was present on MRI in 10/12 patients with weakness and 0/13 with pain. Electromyography was positive in 9/12 with weakness and negative when obtained in 5 patients with pain. Ultrasound-guided suprascapular nerve injection was performed in 10/13 with pain and provided mean 91% symptom relief. Patients with pain had longer duration of pre-operative symptoms (22.2 [±13.1] vs. 10.3 [±13.6] weeks). Postoperatively, the pain group had significant improvement in VAS scores (6.2 [±1.6] to 1.0 [±0.9]), while the weakness group had significant improvement in abduction and external rotation motor grading (3.7 [±0.7] to 4.7 [±0.4] and 3.3 [±0.8] to 4.4 [±0.6] respectively). Return to duty or sport was 92% at a mean of 14.6 (±9.3) weeks. Conclusions: In this young, active cohort, suprascapular neuropathy presented with one of two distinct primary presenting complaints: pain or weakness. Given different expected work-up findings, categorizing patients into one of these two groups may be beneficial in effectively diagnosing and treating suprascapular neuropathy. Outcomes after arthroscopic suprascapular nerve release at the suprascapular notch predictably led to successful pain relief and strength improvement in patients presenting with pain and weakness respectively. [ABSTRACT FROM AUTHOR]

Objectives: Patellar dislocations are associated with a high risk of patellofemoral osteoarthritis (OA). The risk is further elevated for adolescent patients and patients who experience multiple dislocations. Quantitative MRI using T1ρ relaxation time mapping characterizes cartilage properties based on concentration of proteoglycans. Elevated T1ρ values identify cartilage degradation that could develop into post-traumatic OA. The current study compares T1ρ relaxation times throughout the knee between adolescents being treated for a single dislocation, multiple dislocations, and healthy controls. The hypothesis of the study is that patellar dislocation will increase T1ρ relaxation times for patellofemoral cartilage, with higher T1ρ relaxation times for multiple dislocations than single dislocations. Methods: The IRB-approved study included 13 patients (16 ± 2 years; 5 females; BMI: 23 ± 3 kg/m², 47 ± 38 days since dislocation) being treated for an initial, unilateral traumatic lateral patellar dislocation, 10 being treated for multiple unilateral dislocations (17 ± 2 years, 2 females; 23 ± 4 kg/m², 55 ± 24 days since most recent dislocation), and 10 healthy controls (16 ± 2 years, 5 females; 22 ± 2 kg/m²). MRI scans included a 3D water excitation dual energy steady state (DESS) scan of the knee for segmentation of cartilage surfaces (slice thickness of 0.7 mm) and a T1ρ relaxation time scan (fat saturated scan, slice thickness = 4 mm, spin lock times = 0, 10, 40, and 80 ms, spin-lock frequency = 500 Hz). Automated algorithms based on machine learning were used to automatically segment cartilage into six compartments: patella, trochlear groove, lateral/medial femur, lateral/medial tibia. The cartilage on the patella and within the trochlear groove were further divided into medial, lateral and central regions. The central region was centered on the patellar ridge for the patella and the deepest points throughout the trochlear groove and extended one-third of the distance to the medial and lateral edges. Additional automated algorithms mapped T1ρ relaxation times to the reconstructed cartilage surfaces (Fig. 1). Mean T1ρ relaxation times were quantified within each region for each knee. The mean T1ρ relaxation times within the regions were compared between the three groups with ANOVA's and Student-Newman-Keuls post-hoc tests. Statistical significance was set at p < 0.05. Results: T1ρ relaxation times were significantly longer for injured knees (both single and multiple dislocations) than controls at the medial and central patella, central trochlear groove, and lateral tibia (Fig. 2). For regions on the patella, the significant differences represented a difference between injured and control knees of 20% or larger. For the other significant regions, the difference was approximately 10%. No significant differences were identified between single and multiple dislocations. Conclusions: For adolescent patients, a patellar dislocation is associated with elevated T1ρ relaxation times for cartilage throughout the knee. Elevated T1ρ values indicate loss of proteoglycan content that reduces cartilage integrity and could be an initiation point for progression to OA. Elevated relaxation times from quantitative MRI is consistent with previous studies focused on patellar dislocations. The current study uniquely focuses on an adolescent population and uniquely compares single to multiple dislocations in the acute phase following injury. The results set a baseline for characterization of progressive cartilage degradation to OA following patellar dislocation for adolescents. The elevated T1ρ relaxation times within the patellofemoral joint are consistent with high risk of long term patellofemoral OA for adolescents who experience patellar dislocations. The elevated T1ρ relaxation times at the lateral tibia indicate an additional risk of tibiofemoral OA. The similar T1ρ relaxation times for single and multiple dislocations was not expected due to the higher risk of patellofemoral OA following multiple dislocations. Traumatic impact of the medial patella against the lateral femoral condyle during a dislocation is a primary contributor to cartilage degradation in the acute phase following a patellar dislocation, as demonstrated by the largest difference between injured knees and controls occurring at the medial patella for first time dislocators. Additional dislocations did not further increase T1ρ relaxation times at the medial patella. Recurrent dislocations could be less traumatic due to previous injury to medial soft tissue restraints, decreasing the influence on cartilage properties. Inflammation and pathologic anatomy can also contribute to cartilage degradation in adolescents experiencing patellar dislocations. Traumatic injury induces an inflammatory response that can be detrimental to cartilage. Pathologic anatomy associated with patellar dislocations includes patella alta, trochlear dysplasia and a lateral position of the tibial tuberosity. Pathologic anatomy can create loading conditions during daily function that adversely influence cartilage. Inflammation and anatomy likely contribute to the significantly elevated T1ρ relaxation times away from the medial patella. Over the long term, inflammation and anatomy may play a greater role in the risk of OA for multiple dislocators than repeated impact injuries. To continue to characterize the continuum from patellar dislocation to OA, additional recruitment is warranted to determine if significant differences can be identified in additional regions. Additional characterization of the influence of inflammation and pathologic anatomy on cartilage degradation is also warranted to identify patients at highest risk of OA and develop treatment strategies to preserve cartilage following patellar dislocations. [ABSTRACT FROM AUTHOR]

Objectives: Rates of anterior cruciate ligament (ACL) injury in the pediatric population have increased in the last 20 years. While many risk factors have been investigated, to the authors knowledge no study has analyzed the difference in the posterior femoral condyles in patients who have sustained ACL rupture. Therefore, this case control study sought to understand the relationship between the medial and lateral posterior condyles, as well as examining distal femoral version. The authors hypothesized that pediatric patients who suffered ACL rupture will have a relatively larger medial posterior femoral condyle leading to increase structural valgus in flexion. Methods: Pediatric patients with a pre-operative knee MRI who underwent ACL reconstruction between February 2016 and June 2020 at a tertiary orthopedic hospital were collected. Cases were matched to controls based on sex, laterality of injury, and age at imaging within 1.5 years. Medial and lateral posterior condylar height was measured for each participant. Condylar difference was calculated as medial posterior condylar height minus lateral posterior condylar height. The distal femoral version was calculated as the angle between the femoral posterior cortical axis and the posterior condylar axis. Mann-Whitney U tests were used to compare continuous variables. Significance was set as a p≤0.05. Results: A total of 72 participants were included in this analysis - 36 cases and 36 controls. Median age was 13.5 ± 3.3 years for all participants. Condylar difference was noted to be 1.8 mm greater in cases than controls (p=0.038), while distal femoral version was noted to be 2.0° greater in cases than controls (p=0.025). Conclusions: This study demonstrated a significantly greater posterior condylar height difference and distal femoral version among pediatric patients who suffered ACL rupture compared to a matched control group. We speculate that this morphology leads to a relative increase in knee valgus in flexion. [ABSTRACT FROM AUTHOR]

Objectives: Superior capsule reconstruction (SCR) was developed as an alternative treatment for irreparable rotator cuff tears. Previous studies showed graft healing is key to improve shoulder function and pain relief after SCR. Graft healing rate after SCR have been reported for irreparable rotator cuff tears in short-term follow-up studies. The objective of this study was to assess graft survival rate and progression of cuff tear arthropathy in minimum 10-year follow-up of arthroscopic SCR. Methods: A total of 48 consecutive patients with 50 affected shoulders underwent SCR using fascia lata autograft for the treatment of irreparable rotator cuff tears by a single surgeon between 2007 to 2011. Of these 48 initially identified patients, 5 had died, 5 had moved and were unable to be contacted, 2 had severe health problems that were unrelated to SCR, 1 refused to participate, and 1 was unable to participate because she was caring for her child with terminal cancer, thus leaving 34 patients with 36 affected shoulders for review. Structural outcomes were evaluated for a minimum of 10 years of follow-up (range, 10-13 years). Acromiohumeral distance (AHD) and Hamada grade (stage of cuff tear arthropathy) were evaluated by using standard radiography. Fatty degeneration of the rotator cuff muscles was evaluated according to the Goutallier grading system. Graft healing and thickness were assessed by using T2-weighted MRI (1.5-T closed-type scanner). By using SYNAPSE software (accuracy, 0.05 mm; FUJIFILM Medical System, Loveland, CO), graft thickness at 1 cm posterior to the bicipital groove in the coronal plane of T2-weighted MRI was measured at the greater tuberosity side (medial aspect of the footprint on the greater tuberosity), at midgraft (top of the humeral head), and at the glenoid side (5 mm posterior to the articular surface on the glenoid). Results: Graft survival rate was 94% (34 of 36 shoulders) at 1 year after SCR, 92% (33 of 36 shoulders) at 2 to 4 years after SCR, and 89% (32 of 36 shoulders) at 5 to 10 years after SCR. Regarding the 30 patients (32 shoulders) whose grafts remained intact, graft thickness at 1 year after SCR was 8.1 ± 1.9 mm on the greater tuberosity, 6.8 ± 1.5 mm at midgraft, and 11.4 ± 2.0 mm on the glenoid. At 10 years after SCR, graft thickness (7.8 ± 1.6 mm on the greater tuberosity, 7.5 ± 1.8 mm at midgraft, 11.2 ± 2.2 mm on the glenoid) did not significantly differ from that at 1 year after SCR (P = 0.14 to 0.52). Although the rate of low intensity on T2 MRI of the grafts at 1 year after SCR was 53% (17 of 32 shoulders), all grafts had become low intensity on T2 MRI by 10 years after SCR (P < 0.001). Compared with the preoperative measurement, AHD was increased significantly at 1, 5, and 10 years after SCR (P < 0.001). Average AHD did not differ among 1, 5, and 10 years after SCR (P = 0.09 to 0.87). Because of the increase in AHD, the Hamada grade at 1, 5, and 10 years after SCR was significantly decreased (i.e., reduced cuff tear arthropathy) (P < 0.001) compared with the preoperative grade. Before SCR, the AHD was significantly narrower and the Hamada grade was significantly higher in the affected shoulder compared with the unaffected shoulder. At 10 years after SCR, neither AHD nor Hamada grade differed significantly between the affected and unaffected shoulders (i.e., cuff tear arthropathy had not progressed during the 10 years or more after SCR) in patients with healed grafts, whereas all 4 of the remaining patients with postoperative graft tear showed increased cuff tear arthropathy to grade 4a or 4b. One patient with graft tear was converted to reverse shoulder arthroplasty. Conclusions: The graft survival rate at 10 years follow-up was 89%. Graft thickness was maintained at 10 years after SCR when graft was healed. Graft healing prevented progression of cuff tear arthropathy after arthroscopic SCR. [ABSTRACT FROM AUTHOR]

Objectives: Adequate visual clarity is paramount to performing arthroscopic shoulder surgery safely, efficiently, and effectively. The addition of epinephrine in irrigation fluid, and the intravenous or local administration of tranexamic acid (TXA) have independently been reported to decrease bleeding thereby improving the surgeon's visualization during arthroscopic shoulder procedures. No study has compared the effect of systemic administered TXA, epinephrine added in the irrigation fluid or the combination of both TXA and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. The purpose of this study is to determine if intravenous TXA is an effective alternative to epinephrine delivered by a pressure-controlled pump in improving arthroscopic shoulder visualization during arthroscopic procedures and whether using both TXA and epinephrine together has an additive effect in improving visualization. Methods: The design of the study was a double-blinded, randomized controlled trial with four 1:1:1:1 parallel groups conducted at one center. Patients aged ≥18 years undergoing arthroscopic shoulder procedures including rotator cuff repair, arthroscopic biceps tenotomy/tenodesis, distal clavicle excision, subacromial decompression and labral repair by five fellowship-trained upper extremity surgeons were randomized into one of four arms: Pressure pump-controlled regular saline irrigation fluid (control), epinephrine (1ml of 1:1000) mixed in irrigation fluid (EPI), 1g intravenous TXA (TXA), and epinephrine and TXA (EPI/TXA). Visualization was rated on a 4-point Likert scale every 15 minutes with 0 indicating 'poor' quality and 3 indicating 'excellent' quality. The primary outcome measure was the unweighted mean of these ratings. Secondary outcomes included mean arterial blood pressure (MAP), surgery duration, surgery complexity, and adverse events within the first postoperative week. Unweighted means (SD) were calculated for visualization and mean arterial pressure (MAP) for each patient. Study group allocation was represented with epinephrine and tranexamic acid being coded in dichotomous variables (used or not used) for each patient. A step-wise linear regression was performed using visualization as the dependent variable and a series of independent variables considered for inclusion: epinephrine, tranexamic acid, surgery duration, complexity, mean arterial pressure, increase in pump pressure, and volume of irrigation fluid. All statistical tests were considered significant if p<0.05. Results: One-hundred and twenty-eight participants with a mean age (± SD) of 56 (± 11) years were randomized. Figure 1 presents the patient flow through the study. Mean visualization quality for the control, TXA, EPI, and EPI/TXA groups were 2.1 (±0.40), 2.1 (±0.52), 2.6 (±0.37), 2.6 (±0.35), respectively. In a regression model with visual quality as the dependent variable, the presence/absence of EPI was the most significant predictor of visualization quality (R=0.525; p<0.001). TXA presence/absence had no effect, and there was no interaction between TXA and EPI. The addition of MAP and surgery duration strengthened the model (R=0.529; p<0.001). Increased MAP and surgery duration were both associated with decreased visualization quality. When surgery duration was controlled, surgery complexity was not a significant predictor of visualization quality. No adverse events were recorded in any of the groups. Conclusions: Intravenous administration of TXA is not an effective alternative to epinephrine in the irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries although its application is safe. There is no additional improvement in visualization when TXA is used in combination with epinephrine beyond the effect of epinephrine alone. [ABSTRACT FROM AUTHOR]

Objectives: Arthroscopic correction of FAI is a powerful way to improve pain and function in athletes and patients. Surgeons learning hip arthroscopy experience a learning curve while gaining competence. The objective of the present study was to evaluate the learning curve in hip arthroscopy for FAI according to improvements in patient-reported outcome instruments. Methods: A retrospective review was performed of a single surgeon's first 1000 hip arthroscopy cases during their first 4 years in practice. Arthroscopy cases that occurred concurrently with PAO or femoral osteotomy (n=360) were excluded. Convenience samples (n=50) were taken from each year in practice. Pre-operative and post-operative HOOS-Pain and HOOS-physical function scores were obtained. Linear trends were assessed, and cutoffs for MCID for HOOS (10 points) were surveyed across time. Students t tests were used for continuous variables and chi squared tests were used for categorical variables and significance was set to p<0.05. Results: During the first 250 cases, a sample of patients was obtained (n=50), and 11/50 did not meet MCID (22%) for HOOS Pain at 1-year follow-up. A convenience sample of cases subsequent to this from cases 251-1000 (n=100) 11/100 after that did not meet MCID (11.0%, p<0.05). The mean 1-year postop HOOS Pain score for year 1 was 82.77, year 2 was 90.56, year 3 was 89.34 and year 4 was 93.48 (P<0.05). Delta HOOS Pain of PS did not change over time, p>0.05). For both HOOS Pain and Physical Function subscales, 1-year postop scores continued to improve over the 4-year 1000-case study period (graph). Conclusions: According to the HOOS validated patient reported outcome instrument, the learning curve for significant benefits in hip arthroscopy is between 130-250 cases. Many patients (almost 80%) saw significant clinical benefit during the learning curve, however the quality of outcome was significantly improved after 250 cases. 1-year post-op PROs appear to continually improve even after cases 750-1000 [ABSTRACT FROM AUTHOR]

Objectives: Patellar instability is estimated to affect approximately 150 out of 100,000 adolescents between the age of 14-18 years old, a rate which is expected to increase over time. Several risk factors have been associated with patellar instability such as younger age, trochlear dysplasia and patella alta. Patella alta is defined as a superiorly-positioned patella, commonly determined using the Caton- Deschamps Index (CDI), with a ratio of 1.3 or greater indicative of patella alta. Patients with patella alta are approximately 2.5-4.0 times more likely to suffer a recurrent patellar dislocation, which is thought to be due to the changes in biomechanics seen in patella alta. Differences in chondral injury in patients with patellar instability between patella alta and patella norma has not been evaluated. Our objective was to retrospectively analyze whether preoperative cartilage damage differs in severity and location between patellar instability patients with and without patella alta. Methods: Patients with patellar instability who underwent patellar realignment surgery at a single institution with a preoperative MRI within 3 months were included. After measurement of CDI on MRI, patients were divided into patella alta (CDI≥1.3) and patella norma groups. To quantify cartilage defect severity, the Magnetic Resonance Imaging Score and Classification system (AMADEUS) was utilized by two sports medicine clinical fellows. The AMADEUS score characterizes cartilage defect size, defect depth, presence of subchondral bone defects, and bone marrow edema. The scale is scored 0-100 with 100 indicating no cartilage damage. In patients with multiple cartilage defects on MRI, each defect was characterized and analyzed independently. Continuous variable data were reported as means with standard deviations and categorical data reported as frequencies with percentages. The distribution of data was assessed with the Shapiro-Wilk test. Continuous data were assessed with the Student's t test and Mann-Whitney U tests as appropriate. Categorical data were assessed with chi-squared analysis. The threshold for significance was set to p < 0.05. Multivariate analysis was conducted with defect depth, bone edema, and AMADEUS score as the dependent variable. All statistical analyses were performed with R Studio (Version 3.6.3, Vienna, Austria). Results: One hundred-twenty-one patients were divided into patella alta (n=50) and patella norma (n=71). The groups did not significantly differ in sex ratio, age at MRI, body mass index (BMI), mean reported number of prior dislocations, or mean interval between first reported dislocation and date of MRI. Thirty-four (68%) of the patella alta group and 44 (62%) of the patella norma group had chondral defects (P=0.625) with no statistically significant difference in the size of the chondral defects between the groups (P=0.419). In both groups, chondral injuries most affected the medial patellar facet (55% in patella alta vs. 52% in patella norma), followed by the lateral facet (25% vs 18%), and lateral femoral condyle (10% vs 14%)(P=0.859). The patella alta group had a smaller proportion of patients who had full thickness defects in comparison to the patella norma group (60% vs 82%; P=0.030). The overall AMADEUS score for the patella alta group was higher (68.9 vs. 62.1; P=0.023) compared to the patella norma group, indicating superior articular cartilage status. When looking at a multivariate regression using AMADEUS score as the dependent outcome, female sex shows an increase in AMADEUS score with a beta estimate of 11.96 (P<0.001). Female sex also shows a higher probability of having no defect associated bone marrow edema (Odds ratio:6.7; P=0.010), and a higher probability of partial-thickness defect rather than full-thickness (Odds ratio:3.9; P=0.004). Age, BMI, interval between dislocation and MRI, and reported number of dislocations were not found to be associated with total AMADEUS score, probability of having defect-associated bone marrow edema, or defect depth. Conclusions: There is a high percentage of cartilage injury in patients with a history of patellar instability with over 60% of patients showing cartilage damage on MRI. Patients with normal patellar height have a higher frequency of full thickness cartilage defects and more severe injury compared to those with patella alta. The location of cartilage injury between alta and norma is similar, with most defects affecting the medial facet, lateral facet, and lateral femoral condyle in descending frequency. [ABSTRACT FROM AUTHOR]

Objectives: Accuracy of femoral tunnel positioning is critical during medial patellofemoral complex (MPFC) reconstruction, as even 5mm of malpositioning has been associated with altered patellofemoral contact pressures. To help identify the appropriate position for femoral tunnel placement, Schottle and others have described radiographic landmarks to identify the MPFC footprint on lateral knee radiographs. These measurements are based on an extension of the posterior cortical line, which can vary based on the length of the femur visible on the radiograph. Because the scope of view can vary between intraoperative imaging modalities, the aim of this study was to assess the effect of femoral length on the accuracy of radiographic landmarks of the MPFC. Methods: In 9 unpaired cadaveric knees, the MPFC footprint was exposed on the medial femur, and the proximal and distal boundaries of the footprint were marked. Lateral fluoroscopic images of the knee were obtained and assessed in 1 cm length increments, beginning 1cm proximal to the posterior condyle and continuing proximally to a femoral length of 8 cms. The MPFC midpoint was described on each image relative to the posterior cortical line of the femur and a line perpendicular to this line, relative to the proximal margin of the posterior condyle. Linear regression analysis was used to assess the effect of femoral length on the radiographic position of the MPFC. ROC curve analysis and Delong test were used to determine ROC curve analysis and Delong test were used, and the minimum amount of femoral length required on radiographs to accurately identify an anatomic femoral tunnel was determined using Youden's J statistic. Results: Using the posterior cortical line as a reference, the radiographic description of the MPFC footprint moved anteriorly with decreasing femoral length on the radiographs, particularly at 4cm and less. However, no proximal-distal change was seen in relation to the line through the proximal margin of the posterior condyle with changing femoral lengths. Linear regression analysis showed a significant relationship between the femoral length and anterior position of the MPFC on radiographs (R = 0.461, R² = 0.212, B= -0.636, p < 0.001). The slope coefficient was -0.636 mm, indicating that for every cm decrease in femoral length, the actual anatomic footprint of the MPFC moves anteriorly by 0.636 mm in relation to the posterior cortical line. Furthermore, ROC curve analysis revealed that a minimum of 4 cm of femoral length on lateral radiographs is required to accurately localize the footprint of the MPFC (AUC 0.79; sensitivity 76.7 %; specificity 69 %; p < 0.001). Conclusions: The radiographic landmarks for the MPFC femoral footprint can change depending on the length of the distal femur visible on radiographs. We found that at least 4cm of the femoral shaft should be visible for the radiographic landmarks to be accurate. As fluoroscopy is frequently used intraoperatively for MPFC reconstruction, our findings may serve as a guide for accurate femoral tunnel placement. [ABSTRACT FROM AUTHOR]

Objectives: Recurrent anterior shoulder instability after arthroscopic Bankart repair presents a challenging clinical problem, with the primary stabilization procedure often portending the best chance for clinical success. While the glenoid track concept continues to evolve, a limitation of the glenoid track is that it relies on bony anatomy without specific considerations for capsuloligamentous integrity or the effect that capsular laxity may have on the glenohumeral contact points throughout shoulder range of motion. The purpose of the study was to determine if capsuloligamentous laxity has a modifying effect on the glenoid track, specifically for on-track lesions with a small distance to dislocation (DTD) from being an off-track lesion or the so-called "near-track" lesion. This may explain why some on-track lesions are at an increased risk of recurrent instability. We hypothesized that patients with ligamentous laxity and "near track" lesions would be at increased risk of recurrent instability following arthroscopic Bankart repair. Methods: Consecutive patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair alone without remplissage for recurrent anterior glenohumeral instability between January 2007 and December 2015 at a single institution were retrospectively reviewed. Patients with less than 2-year follow up, glenoid bone loss > 20%, off-track lesions, concomitant remplissage, and atraumatic instability were excluded. Determination of shoulder laxity was based on exam under anesthesia (EUA), including anterior load and shift, posterior load and shift, and sulcus testing at the time of surgery before arthroscopy. Capsuloligamentous shoulder hyperlaxity was defined as external rotation of >85° and/or grade of 2+ or greater load and shift in two or more planes. Measurements of glenoid bone loss, Hill-Sachs interval (HSI), and glenoid track (GT) were performed based on prior described methods. DTD was calculated (DTD=GT-HSI, with DTD>0 classified as on-track lesions). Near track lesions were defined as 01 instability episode preoperatively (p=0.018), and smaller DTD (p=0.0008). Hyperlaxity was associated with the use of more anchors (p=0.0001). Shoulder laxity was not independently predictive of overall failure (Figure 1, p=0.18); however, DTD was significantly associated with failure risk and recurrent instability in patients with hyperlaxity (p=0.006) specifically in younger patients with hyperlaxity (Figure 1, Table 1). Conclusions: Our study suggests that while capsuloligamentous laxity is not independently predictive of failure after arthroscopic Bankart repair for on-track lesions, laxity may play a significant role in clinical outcomes in patients with a small DTD or near-track lesions. In younger patients with near-track lesions, hyperlaxity may be particularly predictive of failure after arthroscopic Bankart repair. As our understanding of the glenoid track continues to evolve, surgeons may need to consider the track concept as a continuum with evolving surgical algorithms other than an arthroscopic Bankart alone in young patients with near track lesions and hyperlaxity. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate whether postoperative treatment with Losartan decreased the revision rate in patients undergoing primary hip arthroscopy. Methods: Patients underwent primary hip arthroscopy with labral repair and CAM osteoplasty and rim trimming between 2012 and 2017. Patients who underwent microfracture, labral debridement or reconstruction, core decompression, ligamentous teres repair or reconstruction, or capsular reconstruction were excluded. Losartan was added to all patients' post-operative protocol in December 2015. Patients who underwent hip arthroscopy prior to November 2015 were included in the no-Losartan group (NOLOS) and patients who had arthroscopy between December 2015 and Dec 2017 were included in the losartan group (LOS). Results: Of the 964 cases, follow-up was obtained on 673 patients (70%). There were 405 patients in the NOLOS group and 268 in the LOS group. There was no difference in gender distribution (P=0.128) between groups. The LOS group was significantly older (36.6 ±13 years) compared to the NOLOS group (34.1±11) (p=0.012). Average follow-up in the NOLOS group was 5.8±2 years and was 4.1±1 years in the LOS group. Revision hip arthroscopy was required in 35 (8.6%) patients in the NOLOS group and 6 (2.2%) patients in the LOS group(p=0.001). There was no difference in age between those patients who required revision (32±11 years) and those who did not (35±12 years) (p=0.137). Conclusions: The prevalence of revision hip arthroscopy was significantly lower (2.2%) in patients who took Losartan as part of their post-operative protocol compared to those who did not (8.6%). Reduction in the need for revision hip arthroscopy can improve patient outcomes and reduce healthcare dollars spent. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the rate of graft failure, return to sport (RTS), and clinical outcomes in patients undergoing osteochondral allograft (OCA) transplantation in the patellofemoral (PF) joint with concomitant tibial tuberosity osteotomy (TTO) compared to those undergoing an isolated PF OCA transplantation. Methods: This is a retrospective review of patients who underwent PF OCA transplantation with or without TTO at a single institution. Patients with a primary patellar or trochlear lesion were included. Those undergoing revision OCA, medial patellofemoral ligament reconstruction (MPLFR), or who had a prior TTO were excluded. Graft failure was defined as cartilage procedure revision, chondroplasty, or conversion to joint replacement. Knee pain and functional outcomes were assessed with Visual Analog Scale (VAS), Knee Injury and Osteoarthritis Outcome Score Joint Restoration (KOOS JR), and Tegner Activity Scale. Additionally, patients were asked about preoperative and postoperative sports activity to determine rate of RTS. Results: A total of 40 patients met inclusion criteria for the study; 35 were available for follow-up at an average of 31.6 ± 7.8 months. The cohort had 20 female (64%) and 15 male (36%) patients; the average age was 34 ± 8 years. Graft failure rates were 7.7% and 22.7% in the PF OCA + TTO and isolated PF OCA groups, respectively (p= 0.254). There were no significant differences in RTS between groups (p=0.668). Among patients who returned to sport at a lower level, those in the OCA + TTO group unanimously cited pain as the primary reason (100%), while most in the isolated OCA group cited fear of re-injury instead (66.7%). Patients who underwent concomitant OCA + TTO experienced reported lower KOOS scores (p=0.009). However, after adjusting for covariates, there was no significant association between TTO (p=0.86) and KOOS. Conclusions: In this study population, patients undergoing OCA with concomitant TTO were found to have comparable return to sport rates compared to patients who underwent an isolated OCA. Both cohorts showed improvements in pain levels and functional outcomes from baseline. However, patients undergoing combined OCA and TTO exhibited higher pain levels with activity and cited pain as the primary reason for return at a lower level of performance. These findings highlight the need for additional well-powered studies to further investigate clinical and functional outcomes following OCA and concomitant TTO to offload the PF compartment. [ABSTRACT FROM AUTHOR]

This section offers news briefs related to the plastics industry as of July 2014. Highlights of the Society of Plastics Engineers Annual Technical Conference held in Las Vegas, Nevada are provided including a session on nanofillers and a presentation on carbon nanotubes. Also mentioned is a list of industry-related events for 2014-15 such as the Plastic Industry Exhibition & Conference 2014, 23rd Annual Thermoforming Conference, and ANTEC 2015/NPE 2015.

The article presents updates related to the American Orthopaedic Society for Sports Medicine (AOSSM). Housing information for the 2009 AOSSM Annual Meeting in Keystone Colorado is reportedly available at the website www.sportsmed.org. March 15, 2009 is reportedly the deadline for the 2009 Subspecialty Certification in Sports Medicine Exam. Information is also provided on the upcoming AOSSM 2009 Specialty Day on February 28, 2009 in Las Vegas, Nevada.

It must be a sign of the times - in terms of the R&D spending being lavished on topical PM technologies, and the degree of competition among the major global powder suppliers - that one could find out more than one would probably ever want to know about a single process step like sinterhardening, by sitting through 12 presentations in four separate sessions at the PM[sup 2]Tec 2003 Conference in Las Vegas, writes Dr JOSEPH M. CAPUS. [ABSTRACT FROM AUTHOR]