Incidence of and Risk Factors for Glenohumeral Osteoarthritis following Anterior Shoulder Instability: A U.S. Population-Based Study with an Average 15-year Follow-up
Objectives: The rate of osteoarthritis (OA) in patients with anterior shoulder instability (ASI) varies within the literature, with the majority of studies investigating rates after surgical stabilization. ASI appears to lead to increased rates of OA, although risk factors for developing OA in non-operative and operative cohorts are not well defined. The purpose of this study was to determine the incidence of clinically symptomatic OA and identify potential risk factors for the development of OA following ASI in a U.S. geographic population of patients under the age of 40. Methods: An established geographic database was used to identify patients less than 40 years old diagnosed with anterior should instability between 1994 and 2016. Patient information, including demographics, imaging and surgical details, was collected and comparative analysis was performed between groups with and without OA at final follow-up, as well as patients who underwent surgical and non-surgical management. Results: The study population consisted of 154 patients with a mean follow-up of 15.2 years (range 5.1-29.8). Overall, 22.7% of patients developed clinically symptomatic glenohumeral OA. Twenty-eight percent of patients who underwent at least 1 surgical intervention and 17% of patients who underwent non-operative management of anterior shoulder instability developed glenohumeral OA (p=0.176). Patients who developed arthritis were older at initial instability event (p=0.002) and had higher BMI (p=0.007). Additionally, patients with OA were more likely to be current or former smokers (p=0.004), have a seizure disorder (p=0.033), and be manual laborers (p=0.044). Risk factors for developing OA included seizure disorders (RR 2.61, 95 % CI 1.34-5.07), cartilage injury on initial MRI (RR 2.48, (1.00-6.13), current or former smoker (RR 2.46, 95% CI 1.37-4.42), laborer occupation (RR 2.14, 95% CI 1.14-4.01), and age at initial instability event (OR 1.09 per year, 95% 1.03-1.17). Athletes (RR 0.51, 95% CI 1.08-3.54), specifically contact athletes at the time of initial instability (RR 0.45, 95% CI 0.21-0.97), were less likely to develop OA. There was no difference in the number of dislocations or number of instability events in patients with and without symptomatic osteoarthritis. Conclusions: In a U.S. geographic population of patients less than 40 years old with ASI, approximately one-fourth of patients developed symptomatic OA at a mean follow-up of 15 years from their first instability event. When accounting for differences in patient demographics, there was no significant difference in the rates of OA in patients who underwent surgical and non-surgical management. Overall, there was an increased risk for the development of OA in patients with seizure disorders, cartilage injury on initial MRI, current or former smokers, laborer occupation and increased age at the initial instability event.
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.
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.