Faculty Bibliography

Background/UNASSIGNED:Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty. Purpose/Hypothesis/UNASSIGNED:The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures. Study Design/UNASSIGNED:Cross-sectional study; Level of evidence, 3. Methods/UNASSIGNED:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain. Results/UNASSIGNED:< .01). Conclusion/UNASSIGNED:Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient's preoperative state but also postoperative pain control and/or postoperative outcomes.

Differences in gait with age or knee osteoarthritis have been demonstrated in laboratory studies using optical motion capture (MoCap). While MoCap is accurate and reliable, it is impractical for assessment outside the laboratory. Inertial measurement units (IMUs) may be useful in these situations. Before IMUs are used as a surrogate for MoCap, methods that are reliable, repeatable, and that calculate metrics at similar accuracy to MoCap must be demonstrated. The purpose of this study was to compare spatiotemporal gait parameters and knee range of motion calculated via MoCap to IMU-derived variables and to compare the ability of these tools to discriminate between groups. MoCap and IMU data were collected from young, older, and adults with knee osteoarthritis during overground walking at three self-selected speeds. Walking velocity, stride length, cadence, percent of gait cycle in stance, and sagittal knee range of motion were calculated and compared between tools (MoCap and IMU), between participant groups, and across speed. There were no significant differences between MoCap and IMU outcomes, and root mean square error between tools was ≤0.05 m/s for walking velocity, ≤0.07 m for stride length, ≤0.5 strides/min for cadence, ≤5% for percent of gait cycle in stance, and ≤1.5° for knee range of motion. No interactions were present, suggesting that MoCap and IMU calculated metrics similarly across groups and speeds. These results demonstrate IMUs can accurately calculate spatiotemporal variables and knee range of motion during gait in young and older, asymptomatic and knee osteoarthritis cohorts.

Background/UNASSIGNED:Osteochondral allograft transplantation is an effective technique for repairing large lesions of the medial femoral condyle (MFC), but its use is limited by graft availability. Purpose/Hypothesis/UNASSIGNED:The present study aimed to determine whether contralateral lateral femoral condyle (LFC) allografts can provide an acceptable surface match for posterolateral MFC lesions characteristic of classic osteochondritis dissecans (OCD). The hypothesis was that LFC and MFC allografts will provide similar surface contour matches in all 4 quadrants of the graft for posterolateral MFC lesions characteristic of OCD. Study Design/UNASSIGNED:Controlled laboratory study. Methods/UNASSIGNED:) were measured using DragonFly software. The process was then repeated for the other allograft plug. Results/UNASSIGNED:= .0002). Conclusion/UNASSIGNED:The present study demonstrates that 20-mm contralateral LFC allografts provide an acceptable surface match for posterolateral MFC lesions characteristic of OCD. Clinical Relevance/UNASSIGNED:With comparable surface matching, MFC and LFC allografts can be expected to present similar stresses on the knee joint and achieve predictably positive clinical outcomes, thus improving donor availability and reducing surgical wait times for matches.

OBJECTIVE:The purpose of this study was (1) to determine which risk factors for patellar instability were associated with the presence of patellofemoral cartilage lesions and (2) to determine how cartilage lesion presence, size, and grade affect postoperative disease-specific quality of life. DESIGN/METHODS:= 121), single variable linear regression was used to determine if the presence, size, or ICRS (International Cartilage Regeneration & Joint Preservation Society) grade of cartilage lesions could predict the 12 or 24+ month postoperative BPII 2.0 score. RESULTS:= 0.015) was associated with the presence of a cartilage lesion. The presence, size, and grade of cartilage lesions were not associated with 12 or 24+ month postoperative BPII 2.0 scores. CONCLUSIONS:Trochlear dysplasia was a risk factor for the development of patellofemoral cartilage lesions in this patient population. Cartilage lesions most commonly involve the distal-medial patella. There was no significant relationship between patellofemoral cartilage lesion presence, size, or grade and postoperative BPII 2.0 scores in short-term follow-up.

Background/UNASSIGNED:In the setting of anterior shoulder instability, it is important to assess the reliability of orthopaedic surgeons to diagnose pathologic characteristics on the 2 most common imaging modalities used in clinical practice: standard plain radiographs and magnetic resonance imaging (MRI). Purpose/UNASSIGNED:To assess the intra- and interrater reliability of diagnosing pathologic characteristics associated with anterior shoulder instability using standard plain radiographs and MRI. Study Design/UNASSIGNED:Cohort study (diagnosis); Level of evidence, 3. Methods/UNASSIGNED:Patient charts at a single academic institution were reviewed for anterior shoulder instability injuries. The study included 40 sets of images (20 radiograph sets, 20 MRI series). The images, along with standardized evaluation forms, were distributed to 22 shoulder/sports medicine fellowship-trained orthopaedic surgeons over 2 points in time. Kappa values for inter- and intrarater reliability were calculated. Results/UNASSIGNED:The overall response rate was 91%. For shoulder radiographs, interrater agreement was fair to moderate for the presence of glenoid lesions (κ = 0.49), estimate of glenoid lesion surface area (κ = 0.59), presence of a Hill-Sachs lesion (κ = 0.35), and estimate of Hill-Sachs surface area (κ = 0.50). Intrarater agreement was moderate for radiographs (κ = 0.48-0.57). For shoulder MRI, interrater agreement was fair to moderate for the presence of glenoid lesions (κ = 0.44), glenoid lesion surface area (κ = 0.35), Hill-Sachs lesion (κ = 0.33), Hill-Sachs surface area (κ = 0.28), humeral head edema (κ = 0.41), and presence of a capsulolabral injury (κ = 0.36). Fair agreement was found for specific type of capsulolabral injury (κ = 0.21). Intrarater agreement for shoulder MRI was moderate for the presence of glenoid lesion (κ = 0.59), presence of a Hill-Sachs lesion (κ = 0.52), estimate of Hill-Sachs surface area (κ = 0.50), humeral head edema (κ = 0.51), and presence of a capsulolabral injury (κ = 0.53), and agreement was substantial for glenoid lesion surface area (κ = 0.63). Intrarater agreement was fair for determining the specific type of capsulolabral injury (κ = 0.38). Conclusion/UNASSIGNED:Fair to moderate agreement by surgeons was found when evaluating imaging studies for anterior shoulder instability. Agreement was similar for identifying pathologic characteristics on radiographs and MRI. There was a trend toward better agreement for the presence of glenoid-sided injury. The lowest agreement was observed for specific capsulolabral injuries.

PURPOSE OF REVIEW/OBJECTIVE:The purposes of this review were to report the currently validated outcomes for OCA transplant patients, discuss the benefits and challenges associated with "return to sports" as an outcome measure, and summarize the currently available data on patients' ability to return to sports after OCA transplant. RECENT FINDINGS/RESULTS:College athletes may take less time than professionals to return to basketball, but there are many factors that can influence this timeframe. Player productivity is decreased ~ 40% and future career length is only 1 to 2 years following return to play. When evaluating all OCA transplant patients, 75-88% of patients return to sport and 38-80% return to their previous level of play at approximately 8-10 months following surgery. Overall graft failure rates are low (0-9.4%) but are based on limited short- to medium-term data. Data on the return to professional and college sports after OCA transplant is limited. Surgeons should consider collecting patient outcomes across multiple domains and contributing data to aggregate databases to allow for better quality outcome data to be reported.

BACKGROUND:Traumatic anterior shoulder instability is a common condition affecting sports participation among young athletes. Clinical outcomes after surgical management may vary according to patient activity level and sport involvement. Overhead athletes may experience a higher rate of recurrent instability and difficulty returning to sport postoperatively with limited previous literature to guide treatment. PURPOSE:To report the clinical outcomes of patients undergoing primary arthroscopic anterior shoulder stabilization within the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Consortium and to identify prognostic factors associated with successful return to sport at 2 years postoperatively. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:Overhead athletes undergoing primary arthroscopic anterior shoulder stabilization as part of the MOON Shoulder Instability Consortium were identified for analysis. Primary outcomes included the rate of recurrent instability, defined as any patient reporting recurrent dislocation or reoperation attributed to persistent instability, and return to sport at 2 years postoperatively. Secondary outcomes included the Western Ontario Shoulder Instability Index and Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow questionnaire score. Univariate regression analysis was performed to identify patient and surgical factors predictive of return to sport at short-term follow-up. RESULTS:A total of 49 athletes were identified for inclusion. At 2-year follow-up, 31 (63%) athletes reported returning to sport. Of those returning to sport, 22 athletes (45% of the study population) were able to return to their previous levels of competition (nonrefereed, refereed, or professional) in at least 1 overhead sport. Two patients (4.1%) underwent revision stabilization, although 14 (28.6%) reported subjective apprehension or looseness. Age ( P = .87), sex ( P = .82), and baseline level of competition ( P = .37) were not predictive of return to sport. No difference in range of motion in all planes ( P > .05) and Western Ontario Shoulder Instability Index scores (78.0 vs 80.1, P = .73) was noted between those who reported returning to sport and those who did not. CONCLUSION:Primary arthroscopic anterior shoulder stabilization in overhead athletes is associated with a low rate of recurrent stabilization surgery. Return to overhead athletics at short-term follow-up is lower than that previously reported for the general athletic population.

PURPOSE:To compare the clinical and functional outcomes of allograft and autograft reconstruction in patients with posterior cruciate ligament (PCL) deficiency. METHODS:The MEDLINE, Embase, and Cochrane Library databases were used to identify all relevant articles. Clinical outcomes including International Knee Documentation Committee, Tegner, and Lysholm scores; joint laxity; and posterior tibial displacement were evaluated. RESULTS:Among the 145 unique articles identified during the title screening, 25 studies published between 2002 and 2016 with a combined population of 900 patients were deemed eligible for inclusion in the review. Of the 900 patients, 603 were treated with autograft and 297 were treated with allograft PCL reconstruction. Five of the included studies directly compared autograft and allograft PCL reconstruction. Most studies found postoperative functional outcomes and joint laxity to improve postoperatively regardless of graft source. With only 1 exception, the included comparative studies found no significant postoperative difference in any of the functional outcome scores between patients treated with allograft and those treated with autograft. Two comparative studies found autograft reconstruction to result in significantly less posterior laxity than in the allograft group, whereas 2 comparative studies found no significant difference in posterior laxity between the 2 groups. CONCLUSIONS:PCL reconstruction results in improved functional outcome scores and joint laxity regardless of graft source. Current studies suggest there is no significant difference in postoperative functional outcomes between patients treated with autograft and those treated with allograft. Patients treated with autograft have donor-site morbidity that is not associated with allograft reconstruction. Some evidence suggests that autograft reconstruction may result in reduced posterior laxity relative to allograft reconstruction. The magnitude of this finding, however, may not be clinically significant. Our review found that decision making based on the current literature is at high risk of potential bias. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

BACKGROUND:Shoulder instability is a common diagnosis among patients undergoing shoulder surgery. PURPOSE:To perform a descriptive analysis of patients undergoing surgery for shoulder instability through a large multicenter consortium. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:All patients undergoing surgery for shoulder instability who were enrolled in the MOON Shoulder Instability Study were included. Baseline demographics included age, sex, body mass index, and race. Baseline patient-reported outcomes (PROs) included the American Shoulder and Elbow Surgeons (ASES) score, Shoulder Activity Score, Western Ontario Shoulder Instability Index (WOSI), 36-Item Health Survey (RAND-36), and Single Assessment Numeric Evaluation (SANE). The preoperative physician examination included active range of motion (ROM) and strength testing. Preoperative imaging assessments with plain radiography, magnetic resonance imaging (MRI), and computed tomography were also included and analyzed. RESULTS:Twenty-six surgeons had enrolled 863 patients (709 male, 154 female) across 10 clinical sites. The mean age for the cohort was 24 years (range, 12-63 years). Male patients represented 82% of the cohort. The primary direction of instability was anterior for both male (74%) and female (73%) patients. Football (24%) and basketball (13%) were the most common sports in which the primary shoulder injury occurred. No clinically significant differences were found in preoperative ROM between the affected and unaffected sides for any measurement taken. Preoperative MRI scans were obtained in 798 patients (92%). An anterior labral tear was the most common injury found on preoperative MRI, seen in 66% of patients, followed by a Hill-Sachs lesion in 41%. Poor PRO scores were recorded preoperatively (mean: ASES, 72.4; WOSI, 43.3; SANE, 46.6). CONCLUSION:The MOON Shoulder Instability Study has enrolled the largest cohort of patients undergoing shoulder stabilization to date. Anterior instability is most common among shoulder instability patients, and most patients undergoing shoulder stabilization are in their early 20s or younger. The results of this study provide important epidemiological information for patients undergoing shoulder stabilization surgery.

Spacecraft exploring Mars such as the Mars Exploration Rovers Spirit and Opportunity, as well as the Mars Science Laboratory or Curiosity rover, have accumulated evidence for wet and habitable conditions on early Mars more than 3 billion years ago. Current conditions, by contrast, are cold, extremely arid and seemingly inhospitable. To evaluate exactly how dry today's environment is, it is important to understand the ongoing current weathering processes. Here we present chemical weathering rates determined for Mars. We use the oxidation of iron in stony meteorites investigated by the Mars Exploration Rover Opportunity at Meridiani Planum. Their maximum exposure age is constrained by the formation of Victoria crater and their minimum age by erosion of the meteorites. The chemical weathering rates thus derived are ∼1 to 4 orders of magnitude slower than that of similar meteorites found in Antarctica where the slowest rates are observed on Earth.