Natural history and clinical outcomes of patients with hypertrophic cardiomyopathy from thin filament mutations.

Hypertrophic cardiomyopathy (HCM) due to thick filament variants is more common; however, HCM due to thin filament variants (HCM-Thin) may be associated with a more malignant phenotype with an increased risk of sudden cardiac death. The aim of this study was to review all the published cases of HCM-Thin to better understand the natural history and clinical outcomes of this disease. A literature review of HCM-Thin identified 21 studies with a total of 177 patients that were suitable for analysis. There were three outcomes of interest, which included a heart failure composite, a ventricular arrhythmia composite and a heart failure and arrhythmia composite outcome. Kaplan-Meier (KM) survival analyses for freedom from each of the abovementioned composite outcomes were completed for the entire cohort and stratified by age of onset and sarcomeric variant. The heart failure composite occurred in 24 (13.6%) patients, the ventricular arrhythmia composite occurred in 30 patients (16.9%) and the combined heart failure and arrhythmia composite occurred in 50 patients (28.2%). In regard to left ventricular ejection fraction (LVEF), the majority of patients were preserved (LVEF > 50%) compared with mildly reduced (LVEF 41%-50%) and reduced (LVEF ≤ 40%) (respectively 26.6% vs. 0.6% vs. 3.4%). The median maximal left ventricular wall thickness (LVWT) was 19.0 mm [interquartile range (IQR) 5.3]. Only 10.7% of the cohort had evidence of left ventricular outflow tract (LVOT) obstruction. Those with paediatric-onset HCM had earlier onset and were at higher risk for each endpoint than their adult counterparts. When stratified by genetic variant, patients with TNNI3 and TPM1 were at a higher risk of the heart failure composite endpoint and the combined heart failure and arrhythmia composite endpoint in comparison with those with the other genetic variants. HCM-Thin is associated with significant morbidity and mortality, with a high arrhythmia burden despite low rates of cardiac obstruction and mild hypertrophy. The paediatric onset of disease and certain sarcomeric variants appear to be associated with a worse prognosis than their adult-onset and other sarcomeric variant counterparts. HCM-Thin seems to have a distinct phenotype, which may require a different management approach.

Successful Noninvasive 12-Lead ECG Mapping-Guided Radiotherapy of Inaccessible Ventricular Tachycardia Substrate Due to Mechanical Valves.

In patients presenting with refractory ventricular tachycardia (VT) and aortic and mitral mechanical prosthetic valves, traditional catheter ablation is challenging. We describe a case in which a novel noninvasive computational electrocardiogram mapping algorithm localized VT sources originating from substrate near the mechanical valves, in which stereotactic ablative radiotherapy eliminated VT in 1.5-year follow-up. (Level of Difficulty: Advanced.).

Heart and Lung Transplant for Mixed Connective Tissue Disease: A Case Report and Implications for Pretransplant Testing.

We present a case of end-stage lung disease secondary to mixed connective tissue disease (MCTD) with concomitant myocarditis found on explant at time of transplant. The patient is a 37-year-old man who was first diagnosed with interstitial lung disease secondary to MCTD at 30 years of age. He underwent en bloc heart-lung transplant for progressive decline in left ventricular ejection fraction and severe pulmonary fibrosis despite immunosuppression with hydroxychloroquine, mycophenolate, and azathioprine. Cardiac MRI failed to demonstrate findings suggestive of myocarditis; however, explant demonstrated significant lymphocytic infiltrate with myocyte damage and areas of fibrosis with myocyte hypertrophy. In patients presenting with unexplained systolic dysfunction in the setting of MCTD, fluorodeoxyglucose-positron emission tomography may be a screening tool and if myocardial inflammation is noted, there may be a role for increased immunosuppression. While this strategy was not employed in our patient, his improvement in left ventricular ejection fraction while on mycophenolate mofetil as compared with HCQ and explant histology suggests a process that may have been further responsive to escalation of immunosuppression.

Thin filament cardiomyopathies: A review of genetics, disease mechanisms, and emerging therapeutics.

All muscle contraction occurs due to the cyclical interaction between sarcomeric thin and thick filament proteins within the myocyte. The thin filament consists of the proteins actin, tropomyosin, Troponin C, Troponin I, and Troponin T. Mutations in these proteins can result in various forms of cardiomyopathy, including hypertrophic, restrictive, and dilated phenotypes and account for as many as 30% of all cases of inherited cardiomyopathy. There is significant evidence that thin filament mutations contribute to dysregulation of Ca2+ within the sarcomere and may have a distinct pathomechanism of disease from cardiomyopathy associated with thick filament mutations. A number of distinct clinical findings appear to be correlated with thin-filament mutations: greater degrees of restrictive cardiomyopathy and relatively less left ventricular (LV) hypertrophy and LV outflow tract obstruction than that seen with thick filament mutations, increased morbidity associated with heart failure, increased arrhythmia burden and potentially higher mortality. Most therapies that improve outcomes in heart failure blunt the neurohormonal pathways involved in cardiac remodeling, while most therapies for hypertrophic cardiomyopathy involve use of negative inotropes to reduce LV hypertrophy or septal reduction therapies to reduce LV outflow tract obstruction. None of these therapies directly address the underlying sarcomeric dysfunction associated with thin-filament mutations. With mounting evidence that thin filament cardiomyopathies occur through a distinct mechanism, there is need for therapies targeting the unique, underlying mechanisms tailored for each patient depending on a given mutation.

Patient Age and Surgical Intervention as Risk Factors for the Development of Osteoarthritis After Posterior Shoulder Instability: A Population-Based Study.

Background: Diagnosis and treatment of posterior shoulder instability (PSI) has improved with advances in imaging and surgical technique. However, the relationship between PSI and osteoarthritis (OA) remains unclear. Purpose: To evaluate a population-based cohort to (1) determine the rate of symptomatic OA, (2) identify patient characteristic risk factors for OA, and (3) evaluate the effect of posterior capsulolabral repair on OA progression. Study Design: Case-control study; Level of evidence, 3. Methods: After review of 324 patient records, we included 115 patients (14 female, 101 male) diagnosed with PSI between January 1994 and July 2012 with an average follow-up of 12.5 years (range, 5-23 years). Medical records were reviewed for patient characteristics, injury characteristics, surgical details (if any), and radiographic progression of OA. Kaplan-Meier survival was used to estimate survival free of OA; characteristics associated with OA progression were determined via univariate Cox regression models, and associated 95% CIs and hazard ratios (HRs) are presented. Results: Overall, 14% (16/115) of patients had radiographic progression of symptomatic glenohumeral arthritis, with 5-year survival of 88.3% (95% CI, 79.7%-97.3%). Older age at the time of instability diagnosis was associated with arthritis progression (10-year unit HR, 1.95; 95% CI, 1.26-3.03). Patients who underwent surgery demonstrated increased radiographic progression of OA (HR, 4.03; 95% CI, 1.23-13.23). There was a trend of increased OA in patients treated with labral debridement compared with repair despite lower baseline levels of OA; however, this difference was not statistically significant (P = .09). Conclusion: Symptomatic glenohumeral arthritis is not seen routinely in patients with PSI. Although uncommon, an age of at least 30 years at the time of diagnosis and surgical intervention were identified as risk factors for developing symptomatic arthritis at long-term follow-up.

Myocarditis following COVID-19 vaccination: incidence, mechanisms, and clinical considerations.

INTRODUCTION: Vaccines have demonstrated protection against the morbidity and mortality of COVID-19, but concerns regarding the rare side effect of acute myocarditis have stymied immunization efforts. This review aims to describe the incidence and theorized mechanisms of COVID vaccine-associated myocarditis and review relevant principles for management of vaccine-associated myocarditis. AREAS COVERED: Epidemiologic studies of myocarditis after COVID vaccination are reviewed, which show an incidence of approximately 20-30 per million patients. The vast majority of these cases are seen with mRNA vaccines especially in male patients under 30 years of age. Mechanisms are largely theoretical, but molecular mimicry and dysregulated innate immune reactions have been proposed. While studies suggest that this subtype of myocarditis is mild and self-limited, long-term evidence is lacking. Principles of myocarditis treatment and surveillance are outlined as they apply to COVID vaccine-associated myocarditis. EXPERT OPINION: COVID vaccine-associated myocarditis is rare but well described in certain at-risk groups. Better understanding of its pathogenesis is key to mitigating this complication and advancing vaccination efforts. Risk-benefit analyses demonstrate that individual- and population-level benefits of vaccination exceed the risks of this rare and mild form of myocarditis.

Total Knee Arthroplasty Function at 25 Years Following Proximal Tibial Osteotomy: Paired Outcomes of Bilateral TKAs Following Unilateral Osteotomy.

BACKGROUND: Proximal tibial osteotomy (PTO) is a well-established treatment for coronal deformity and focal cartilage defects. However, the utility of joint-preserving interventions must be weighed against potential effects on subsequent total knee arthroplasty (TKA). The purpose of this study was to determine the effect of PTO on subsequent TKA by comparing outcomes in patients with bilateral TKAs following unilateral PTO. METHODS: Patients who underwent bilateral TKAs from 2000 to 2015 at a single institution and had previously undergone a unilateral valgus-producing PTO were reviewed. We evaluated 140 TKAs performed in 70 patients (24 female, 46 male) with a mean age at PTO of 50 ± 8 years. The patients underwent conversion to TKA at a mean of 14 ± 7 years following ipsilateral PTO and were followed for a mean of 25 ± 7 years (range, 6 to 40 years) following PTO. The Knee Society Score (KSS), Forgotten Joint Score-12 (FJS-12), subjective knee preference, and revision were compared between the PTO-TKA and contralateral TKA-only sides. RESULTS: The PTO side demonstrated similar KSS Knee subscores (41 ± 16) compared with the contralateral side (39 ± 16, p = 0.67) immediately prior to arthroplasty. Patients had significant improvements in KSS (p < 0.001) after TKA, with clinically similar KSS values at 2 to 15 years of follow-up when knees were compared in a pairwise fashion (p = 0.10 to 0.83). Five PTO-TKA knees (7%) and 4 control TKA-only knees (6%) underwent revision at a mean of 5 years postoperatively (p = 0.76). The number of all-cause reoperations was approximately twice as high in PTO-TKA knees (13% compared with 6% in TKA-only knees, p = 0.24). At the time of final follow-up, PTO-TKA knees demonstrated similar FJS-12 scores (72 ± 26) compared with the contralateral knees (70 ± 28, p = 0.57). Nineteen percent of patients preferred the PTO-TKA knee, 19% preferred the contralateral TKA-only knee, and 62% stated that their knees were equivalent (p > 0.99). The final Tegner activity score was 2.5 ± 1.4. CONCLUSIONS: Long-term clinical function of TKA following PTO was excellent, with patients demonstrating comparable subjective outcomes and equivalent knee preference compared with the contralateral TKA-only knees. Further, well-matched studies are needed to evaluate long-term revision and reoperation rates following PTO-TKA. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Indoor Skydiving: An Emerging Cause of Anterior Shoulder Dislocations.

Background: The risks of indoor skydiving have not been extensively studied. Indoor skydiving facilities are often used for corporate events and parties and by relatively inexperienced participants who may not appreciate the risks involved. The abducted and externally rotated shoulder position, combined with nearby walls, tight spaces, and the strong airstream, has resulted in a pattern of shoulder dislocation injuries. Case Report: A 26-year-old male presented with recurrent left shoulder instability after developing an engaging Hill-Sachs lesion following traumatic anterior shoulder dislocation while indoor skydiving. He entered the wind tunnel with his arms abducted and externally rotated. The wind created an upward force that held his arms in this position. As he reached with his left arm for the side of the tunnel to exit, his arm was forced into further external rotation, dislocating the shoulder. The patient was treated arthroscopically with a remplissage procedure and repair of the glenoid labrum. Postoperatively, he resumed his active lifestyle and sports without further dislocations or instability. Conclusion: Indoor skydiving may pose a high risk of anterior dislocation because the shoulder is forced into abduction and external rotation in the free-fall position. We advise caution before participation in indoor skydiving by any individual, but especially those with a history of shoulder instability.

Nonoperative Management of Posterior Shoulder Instability: What Are the Long-Term Clinical Outcomes?

OBJECTIVE: To report the injury characteristics, radiographic findings, and long-term outcomes of nonoperative management for posterior shoulder instability (PSI). DESIGN: A retrospective review of 143 patients with PSI using a large geographic database. SETTING: Single county between January 1994 and July 2012. PATIENTS: A clinical history and diagnosis of PSI, one confirmatory imaging study to support the diagnosis, and a minimum of 5 years follow-up were required for inclusion. Patients with seizure disorders, anterior-only instability, multidirectional instability, and superior labrum from anterior to posterior diagnosis were excluded. INTERVENTIONS: Patients with PSI were managed nonoperatively or operatively. MAIN OUTCOME MEASURES: Pain, recurrent instability, and progression into glenohumeral osteoarthritis at long-term follow-up. RESULTS: One hundred fifteen patients were identified. Thirty-seven (32%) underwent nonoperative management. Twenty (54%) patients were diagnosed with posterior subluxation, 3 (8%) with a single dislocation, and 7 (19%) with multiple dislocations. Symptomatic progression of glenohumeral arthritis was observed in 8% (3) of patients. Pain improved in 46% (17) of patients and worsened in 19% (7). Recurrent instability and progression to osteoarthritis occurred in 15% (3/20) of patients with a traumatic instability event compared with 0% of atraumatic patients after nonoperative management (P = 0.234). Pain at follow-up was more common in nonoperative than operative patients (P = 0.017). CONCLUSIONS: Nonoperative management is a viable option for many patients with posterior shoulder instability; however, many may continue to have posterior shoulder pain.

High Tibial Osteotomy with a Modern Polyetheretherketone (PEEK) System: Mid-Term Results at a Mean of 6 Years Follow-Up.

The purpose of this study was to determine patient-reported outcomes, hardware removal rates, as well as conversion to arthroplasty at mid-term follow-up following high tibial osteotomy (HTO) with a modern polyetheretherketone (PEEK) system. All PEEK system-based HTOs performed at a single institution between January 2010 and January 2016 with a minimum of 2 years follow-up were reviewed. Rates of postoperative complications, hardware removal and conversion to arthroplasty were calculated. Patient-reported outcomes including visual analog pain scale (VAS), Tegner activity scale, Lysholm, Knee Injury and Osteoarthritis Outcome Score (KOOS), and 36-Item Short Form Survey (SF-36) were obtained. Forty-seven HTOs in 43 patients (mean age: 37.6 ± 10.8 years; 30 M, 13 F) were followed for a mean of 6.0 ± 1.5 years. A total of four postoperative complications occurred in three patients, resulting in an overall complication rate of 6.4%. Hardware removal occurred in three patients at a mean of 0.73 ± 0.53 years after surgery, with overall survival free of hardware removal of 96% (95% confidence interval [CI]: 85-99) at 1 year, 94% (95% CI: 82-98) at 2 years, and 94% (95% CI: 82-98) at 8 years. Conversion to arthroplasty occurred in three patients at a mean of 3.2 ± 1.0 years after surgery, with mean survival of 100% (95% CI: 94-100) at 1 year, 100% (95% CI: 94-100) at 2 years, and 93% (95% CI: 81-98) at 8 years. VAS at rest improved, from 3.1 ± 2.5 preoperatively to 1.1 ± 1.6 postoperatively (p < 0.001). Patients remained active, with a mean Tegner activity scale of 4.4 ± 1.4 at final follow-up and satisfactory Lysholm, KOOS, and SF-36 scores. At mid-term follow-up, medial opening-wedge HTO using a modern PEEK-based system was found to be safe, efficacious, and durable, with satisfactory outcome scores and a low rate of conversion to arthroplasty. PEEK-based implants were found to have low hardware removal rates of 6% at 5 years, which compares favorably to historic metal fixation. This is a Level III study.

A Strategy for Repair, Augmentation, and Reconstruction of Knee Extensor Mechanism Disruption: A Retrospective Review.

BACKGROUND: The loss of extensor mechanism continuity that occurs with patellar and quadriceps tendon rupture has devastating consequences on patient function. PURPOSE: To describe a treatment strategy for extensor mechanism disruption and evaluate the outcomes of 3 techniques: primary repair, repair with semitendinosus tendon autograft augmentation, and reconstruction with Achilles tendon allograft. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors reviewed surgeries for extensor mechanism disruption performed by a single surgeon between 1999 and 2019. Patient characteristics, imaging studies, surgical techniques, and outcomes were recorded. Primary ruptures with robust tissue quality were repaired primarily, and first-time ruptures with significant tendinosis or moderate tissue loss were repaired using quadrupled semitendinosus tendon autograft augmentation. Patients with failed previous extensor mechanism repair or reconstruction and poor tissue quality underwent reconstruction with Achilles tendon allograft. The primary outcome was extensor mechanism integrity at a minimum 1-year follow-up, with extensor mechanism lag defined as >5° loss of terminal, active knee extension. Secondary outcomes included postoperative knee range of motion, International Knee Documentation Committee (IKDC) and Tegner activity scores, and the radiographic Caton-Deschamps Index. RESULTS: Included were 22 patellar tendon and 21 quadriceps tendon surgeries (patients: 82.5% male; mean age, 48.1 years; body mass index, 31). Seventeen (39.5%) cases underwent primary tendon repair, 13 (30.2%) had repair using semitendinosus tendon autograft augmentation, and 13 (30.2%) underwent reconstruction using an Achilles tendon allograft. Seventeen (39.5%) cases had at least 1 prior failed extensor mechanism surgery performed at an outside facility. At the last follow-up, 4 (9.3%) cases had an extensor mechanism lag, no cases required additional extensor mechanism surgery, and all cases were able to achieve >90° of knee flexion. Postoperative IKDC scores were significantly improved with all methods of extensor mechanism surgery, and postoperative Tegner activity scores were significantly improved in patients who underwent primary repair and Achilles tendon allograft reconstruction (P < .05 for all). CONCLUSION: Primary repair alone, repair using quadrupled semitendinosus tendon autograft augmentation, and reconstruction using Achilles tendon allograft were all effective methods to restore extensor mechanism and knee function with the proper indications. Persistent knee extensor lag was more common in chronic extensor mechanism injuries after failed surgery, although patients still reported significantly improved postoperative functional outcomes.

Good Surgical Outcomes After Concomitant Repair of Double Radial Tears of the Lateral Meniscus and Anterior Cruciate Ligament Reconstruction.

PURPOSE: To describe double radial tears of the lateral meniscus (LM), report early clinical treatment outcomes, and determine reoperation and failure rates. METHODS: Twenty-one (N = 21) consecutive cases of arthroscopic-treated lateral meniscus double radial tears treated between 2012 and 2018 were reviewed, including 15 males (71.4%) and 6 females (28.6%). Meniscus repairs were all performed at the time of anterior cruciate ligament (ACL) reconstruction. Patients with associated fractures or prior surgeries were excluded. Concomitant injuries were reported, as were preinjury and postoperative Tegner scores, preoperative and postoperative visual analogue pain scale (VAS) scores, and postoperative International Knee Documentation Committee (IKDC) subjective scores. Reoperation and failure rates were documented. RESULTS: Twenty-one (N = 21) tears were located in the posterior horn of the meniscus near the root attachment; 15 (71.4%) underwent all-inside repair, 4 (19.0%) underwent transtibial pull-through repair, 1 (4.8%) was partially debrided, and 1 (4.8%) was left untreated. Twenty-one tears (N = 21) were in the body of the meniscus; 7 (33.3%) were repaired, 7 (33.3%) were partially debrided, and 7 (33.3%) were left untreated. Thirteen patients (62%) had associated medial collateral ligament (MCL) injuries. Mean follow-up was 2.6 years. VAS at rest and with activity improved by 2.1 points (P < .001) and 3.1 points (P = .017) after surgery. The mean postoperative Tegner activity score was 6.4, and the mean IKDC score was 83.2 at final follow-up. Reoperation was required in 5 patients (23.8%), and the surgical treatment failed in 1 patient (4.7%). CONCLUSIONS: Double radial tears of the LM are uncommon injuries that occur in the setting of ACL tears, usually combined with MCL injury. The variety of surgical treatment techniques have a low failure rate at short-term follow-up. Patients tend to have good clinical outcomes with improvement in pain and overall function after surgically treating these injuries with simultaneous ACL reconstruction. LEVEL OF EVIDENCE: Level IV, therapeutic study, case series.

Surgical Treatment of Isolated Meniscal Tears in Competitive Male Wrestlers: Reoperations, Outcomes, and Return to Sport.

BACKGROUND: Wrestlers are highly active, young athletes prone to meniscal injuries that often require surgery. However, there is a lack of data evaluating the results of meniscal repair or partial meniscectomy in this cohort. PURPOSE: To describe the outcomes (subjective function, return to play, complications, reoperation rates, and progression of osteoarthritis) for treatment (meniscectomy or repair) of meniscal injuries in a cohort of competitive wrestlers. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All competitive wrestlers (high school, collegiate, or professional leagues) with a history of a meniscal injury and isolated meniscal surgery at a single institution between 2001 and 2017 were retrospectively identified. Failure was defined as a reinjury of the operative meniscus by clinical or advanced imaging examination, reoperation, or any additional surgical treatment of the meniscus after the index procedure. All patients were contacted for determination of reinjury rates, current sport status, and International Knee Documentation Committee and Tegner activity scores. RESULTS: Of 85 male wrestlers with isolated meniscal tears, 34% underwent a meniscal repair, and 66% received a partial meniscectomy. Index surgery failed for 9.4% of the cohort. Among wrestlers treated with initial meniscal repair, 21% required a subsequent partial meniscectomy at a mean 2.2 years, and of those treated with partial meniscectomy, 3% underwent a second operation (P < .001). All secondary operations were revision partial meniscectomies occurring at a mean 3.2 years (95% CI, 0.01-6.4 years) after the index procedure. At final follow-up, 89% of patients were able to return to sport, with 65% returning to wrestling competition. There was significant improvement in the Tegner score from a mean 6.5 (95% CI, 5.9-7.2) preoperatively to 8.3 (95% CI 8.0-8.6) postoperatively (P < .001). CONCLUSION: The reoperation rate after meniscal surgery in wrestlers was quite low, but only 65% returned to competitive wrestling. Meniscal repair and partial meniscectomy improved patient-reported outcomes and activity levels at short-term follow-up. However, 21% of wrestlers treated with initial meniscal repair required a subsequent partial meniscectomy at a mean 2.2 years.

Although Surgical Techniques Differ, Similar Outcomes Can Be Obtained When Operating After Single Versus Multiple Anterior Shoulder Dislocations.

PURPOSE: To compare the differences in preoperative pathology, surgical technique, and overall outcomes between patients treated surgically after a single anterior glenohumeral joint dislocation and those undergoing surgery after multiple dislocations. METHODS: An epidemiologic database was used to identify all patients younger than 40 years undergoing surgery for anterior shoulder instability between January 1, 1994, and July 31, 2016, in a defined geographic area. Patient medical records were reviewed to obtain demographic information, patient history, physical examination findings, imaging findings, clinical progression, surgical details, and outcomes. Comparative analysis was performed between patients who underwent surgery after a single dislocation and those who underwent surgery after multiple preoperative dislocations. RESULTS: The study population consisted of 187 patients who had a single anterior shoulder dislocation (n = 55) or multiple anterior shoulder dislocations (n = 132) prior to surgery. The mean follow-up period was 103.3 months (range, 0.3-328.4 months). Demographic characteristics were not significantly different between groups. Although the presence of Hill-Sachs lesions on radiographs was more common in the multiple-dislocation group (42.1%) than in the single-dislocation group (18.8%, P = .005), there were no other significant differences in concomitant pathology between groups. Latarjet procedures were more commonly performed in the multiple-dislocation group (12.5% vs 2.1% in the single-dislocation group, P = .04). There were no other significant differences in surgical techniques and characteristics between groups. Rates of survival free from recurrent instability (P = .790), revision surgery (P = .726), and progression to symptomatic osteoarthritis (P = .588) were not significantly different between groups. CONCLUSIONS: Although patients with multiple dislocations prior to surgery were more likely to show radiographic evidence of Hill-Sachs lesions and undergo the Latarjet procedure than those who received surgery after a single dislocation, no significant differences in outcomes with respect to recurrent instability, revision surgery, or progression to symptomatic osteoarthritis were found between these 2 groups at long-term follow-up. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Establishing the learning curve for elbow arthroscopy: surgeon and trainee perspectives on number of cases needed and optimal methods for acquiring skill.

BACKGROUND: Elbow arthroscopy has increased in frequency as its indications have widened. Despite this growth, a learning curve has not yet been defined. HYPOTHESIS: We hypothesized that there would be significant differences in perspective between trainees and established surgeons for the number of cases needed to reach each skill level and what they felt are the most valuable training tools. METHODS: Orthopedic attending physicians and trainees were asked to complete a questionnaire assessing participant demographics, case volumes required to reach defined skill levels (novice, safe, competent, proficient, and expert), and the efficacy of various learning methodologies for elbow arthroscopy. The value of educational methods was assessed using a 5-point Likert scale (1 = not at all valuable; 5 = extremely valuable). RESULTS: The study population consisted of 323 total participants, of whom 224 (69.3%) were attending surgeons and 99 (30.7%) were trainees (resident or fellow physicians). According to the attending physicians, the mean numbers of cases needed to reach each skill level were 19 to be safe, 42 to be competent, 93 to be proficient, and 230 to be expert. These case numbers were not significantly different from the perspectives of trainees. Across the respondents, there were no significant differences in the number of cases needed to reach each level of skill based on the respondents' level of training, years of experience, type of fellowship, or self-reported skill level.Although both groups highly valued live surgery (4.7 of 5) and cadaveric practice (4.6 of 5) for acquiring skill, attendings placed higher value on reading (4.0 vs. 3.3, P < .001), videos/live demos (4.2 vs. 3.6, P < .001), and formal courses (4.5 vs. 4.1, P < .001) than trainees. Both groups place relatively low value on surgical simulators (2.8-3.6). CONCLUSIONS: There was considerable agreement among attending surgeons and trainees in terms of the number of cases needed to attain various skill levels of elbow arthroscopy, which was consistent regardless of fellowship background, self-reported skill level, career length, and elbow arthroscopy case volume. However, there was some disagreement between attending surgeons and trainees over the most valuable methods for acquiring surgical skill with trainees placing less value on textbooks, surgical videos, and formal courses compared with attending surgeons. An understanding of the elbow arthroscopy learning curve will help trainees and their training programs establish case volume targets before safe, independent practice. Future studies should aim to clinically validate this learning curve.

A Novel Scoring Instrument to Assess Donor Site Morbidity After Anterior Cruciate Ligament Reconstruction With a Patellar Tendon Autograft at 2-Year Follow-up Using Contemporary Graft-Harvesting Techniques.

BACKGROUND: Donor site morbidity after anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BTB) autograft is clinically significant, but evidence with contemporary techniques is lacking. PURPOSE: To (1) evaluate donor site morbidity at a single institution using modern techniques of BTB autograft harvest at 2-year follow-up, (2) develop a 10-question donor site morbidity instrument, and (3) compare this instrument against traditional outcome tools. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We analyzed the 2-year follow-up outcomes of 200 consecutive patients who underwent ACL reconstruction with a BTB autograft performed by 2 surgeons at a single institution. The surgical technique utilized modern and consistent BTB autograft harvest, including graft sizing, patellar tendon and peritenon closure, and patellar and tibial donor site bone grafting. There were 187 patients included, with 13 patients undergoing revision ACL reconstruction excluded. An original 10-question scoring instrument evaluating donor site morbidity was administered to each patient (score, 0-100) and compared against each patient's International Knee Documentation Committee (IKDC) and Lysholm scores. RESULTS: Overall, 13.9% of patients were noted to have anterior knee pain with activity at 2-year follow-up. Moreover, 3.7% of patients reported an inability to kneel on hard surfaces but had no problems on soft surfaces; 5.9% of patients reported mild discomfort but were able to kneel on all surfaces. Additionally, 75.4% of patients had a perfect (100/100) donor site morbidity score. The mean donor site morbidity score at 2-year follow-up was 98.3 ± 3.4. There was a very strong correlation between the IKDC and Lysholm scores but only a strong and moderate correlation when the donor site morbidity score was compared with the IKDC and Lysholm scores, respectively. CONCLUSION: Donor site morbidity after ACL reconstruction with a BTB autograft was less frequent than reported in the existing literature. Some patients developed anterior knee pain; therefore, an informed discussion is advised. IKDC and Lysholm scores may not capture donor site symptoms after surgery. The 10-question donor site morbidity instrument may provide a more accurate assessment.

Lateral Meniscal Oblique Radial Tears Are Common With ACL Injury: A Classification System Based on Arthroscopic Tear Patterns in 600 Consecutive Patients.

BACKGROUND: Meniscal root tears and ramp lesions have been rigorously characterized in recent literature. However, one of the most common lateral meniscal injuries identified with an acute anterior cruciate ligament (ACL) disruption, a posterior horn lateral meniscal oblique radial tear (LMORT), has not been thoroughly described. PURPOSE: To determine the incidence of all meniscal tears and, more specifically, the incidence of posterior horn LMORTs in a multicenter cohort of consecutive, acute ACL reconstructions. Additionally, the authors aimed to develop a new classification system to help guide treatment of posterior horn LMORTs. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A multicenter retrospective cohort design was used to analyze 200 consecutive cases of acute ACL reconstruction from each of 3 different surgeons, for a total of 600 patients. The operative notes and intraoperative photos were analyzed to determine the incidence and laterality of all meniscal tears. A classification system based on tear characterization was then used to categorize tear patterns into similar groups. RESULTS: A total of 396 (66%) of the 600 patients with acute ACL disruption had concomitant meniscal tears. Specifically, 187 (31%) had a lateral meniscal injury, 89 (15%) had a medial meniscal injury, and 122 (20%) had both medial and lateral meniscal injuries. The most common lateral meniscal tear was an LMORT; 71 (18%) patients with meniscal tears had a posterior horn LMORT. Overall, the incidence of ACL injury with a concomitant posterior horn LMORT was 12%. A classification was developed, which included type 1 tear (partial thickness <10 mm from the root attachment), type 2 tear (complete radial oblique tear that extended <10 mm from root), type 3 tear (incomplete LMORT that extended >10 mm from root), and type 4 tear (complete LMORT >10 mm from root). CONCLUSION: In 600 consecutive acute ACL reconstructions, the incidence of concomitant ACL injury with meniscal injury was 66%, and posterior horn LMORTs represented a large proportion of all meniscal tears (12%). A classification scheme was developed for posterior horn LMORTs to aid reporting and clinical decision making for these common tears.

Revision Medial Ulnar Collateral Ligament Reconstruction in Baseball Pitchers: Review of Epidemiology, Surgical Techniques, and Outcomes.

PURPOSE OF REVIEW: The purposes of this review are to describe the epidemiology, treatment options, and clinical outcomes of revision medial ulnar collateral ligament reconstruction in baseball pitchers. RECENT FINDINGS: Rates of revision UCL range from 1 to 15% and have slowly increased over the past several years. Revision UCL procedures are associated with higher complication rates, likely due to the distortion of innate anatomy after primary reconstruction. Techniques for reconstruction are largely influenced by the index surgery and integrity of the ulnar and humeral bone tunnels/sockets. Current literature reporting on the outcomes following revision UCL reconstruction is limited to case series and database studies. Mean time between primary reconstruction and revision surgery is approximately 5 years and return to play rates range from 47 to 85%. Outcomes following revision UCL reconstruction are relatively guarded compared with those of primary UCL reconstruction with the most studies reporting lower return to play rates, decreased workloads compared with pre-injury levels of play, and shorter career longevity following revision surgery. Future research regarding optimal reconstruction techniques and post-operative rehabilitation are needed as the incidence and demand for this procedure is expected to increase.

An Age-Based Approach to Anterior Shoulder Instability in Patients Under 40 Years Old: Analysis of a US Population.

BACKGROUND: While a large volume of literature has focused on risk factors for anterior shoulder instability, the rates of recurrence are inconsistent and require additional population-based epidemiologic data. PURPOSE/HYPOTHESIS: The purpose was to report the effect of patient age on the number of instability events before physician consultation, rate of surgical stabilization, recurrent instability, and progression to osteoarthritis in patients <40 years old with anterior shoulder instability, utilizing an established US geographic population. We hypothesized that younger patients would be more likely to experience multiple episodes of instability before evaluation, undergo surgery, and experience recurrent instability after surgical intervention. STUDY DESIGN: Descriptive epidemiologic study. METHODS: An established geographic database of more than 500,000 patients was used to identify patients <40 years of age with anterior shoulder instability between 1994 and 2016. Medical records were reviewed to obtain patient characteristics, history, imaging, surgical details, and outcomes. Patients were divided into 5 groups based on age (≤15, 16-20, 21-25, 26-30, and 31-40 years) at initial instability. Comparative analysis was performed to identify differences between groups. RESULTS: The study population consisted of 654 patients with a mean follow-up of 11.1 years (range, 2.0-25.2 years). This resulted in 118 patients (18%) ≤15 years of age at initial instability; 250 (38%), 16 to 20 years; 110 (17%), 21 to 25 years; 80 (12%), 26 to 30 years; and 96 (15%), 31 to 40 years. Of patients ≤15 years old at initial instability 47% had 3+ instability events, compared with 12% of patients aged 31 to 40 years (P < .001). At 10 years of follow-up, patients ≤15 and 16 to 20 years old demonstrated the highest recurrent instability rates of 38.8% and 47.1% after nonoperative management, respectively. Patients 16 to 20 years old demonstrated the highest rates of both surgical intervention (40.4%) and recurrence after surgery (24.8%). Patients 31 to 40 years of age were significantly more likely to develop clinically symptomatic osteoarthritis (15.6%) than all other age groups. CONCLUSION: In a US epidemiologic population of patients <40 years old, the rate of recurrent anterior shoulder instability was roughly one-third after initial physician consultation. Younger patients, particularly those ≤15 and 16 to 20 years of age, were more likely to have experienced multiple instability events at the time of initial evaluation, require surgery, and experience recurrent instability compared with older patients. For every year of decrease in age at initial instability, the risk of recurrent instability or surgical intervention after physician consultation increased by 4.1% and 2.8%, respectively.

Biomechanical Study of a Multifilament Stainless Steel Cable Crimp System Versus a Multistrand Ultra-High Molecular Weight Polyethylene Polyester Suture Krackow Technique for Achilles Tendon Rupture Repair.

Currently, Achilles tendon rupture repair is surgically addressed with an open or minimally invasive approach using a heavy, nonabsorbable suture in a locking stitch configuration. However, these sutures have low stiffness and a propensity to stretch, which can result in gapping at the repair site. Our study compares a new multifilament stainless steel cable-crimp repair method to a standard Krackow repair using multistrand, ultra-high molecular weight polyethylene polyester sutures. Eight matched pairs of cadavers were randomly assigned for Achilles tendon repair using either Krackow technique with polyethylene polyester sutures or the multifilament stainless steel cable-crimp technique. Each repair was cyclically loaded from 10 to 50 N for 100 loading cycles, followed by a linear increase in load until complete failure of the repair. During cyclic loading, 4 of the 8 Krackow polyethylene polyester suture repairs failed, whereas none of the multifilament stainless steel cable crimp repairs failed. Load to failure was greater for the multifilament stainless steel cable crimp repairs (321.03 ± 118.71 N) than for the Krackow polyethylene polyester suture repairs (132.47 ± 103.39 N, p = .0078). The ultimate tensile strength of the multifilament stainless steel cable crimp repairs was also greater than that of the Krackow polyethylene polyester suture repairs (485.69 ± 47.93 N vs 378.71 ± 107.23 N, respectively, p = .12). The mode of failure was by suture breakage at the crimp for all cable-crimp repairs and by suture breakage at the knot, within the tendon, or suture pullout for the polyethylene polyester suture repairs. The multifilament stainless steel cable crimp construct may be a better alternative for Achilles tendon rupture repairs.