Swinging injuries in competitive baseball players.

Injuries are common in competitive baseball players and can occur in all facets of the game. The majority of the existing literature on injuries in baseball players has focused on injuries secondary to the overhead throw with very little attention given to injuries sustained while batting. The baseball swing is a complex, often violent, motion that predisposes batters to a variety of injuries affecting the spine, trunk, pelvis, and extremities. Knowledge of injury patterns that commonly occur during the baseball swing and radiologic findings important to the treating physician can help radiologists provide accurate imaging interpretations that appropriately guide patient management.

Normal Humeral Head Ossification in Pediatric and Adolescent Shoulders Can Mimic Hill-Sachs Lesions: A Magnetic Resonance Imaging-based Study.

BACKGROUND: The sequential maturation of the humeral head (HH) as viewed on magnetic resonance imaging (MRI) has not been described to date. Proper assessment may be complicated by the presence of physeal tissue in pediatric patients. Past studies suggest that skeletally immature patients may also have a higher risk of a false-positive diagnosis of Hill-Sachs lesion on MRI. The purpose of this study was to define pediatric HH developmental patterns using MRI and to investigate for any associations with findings of known false-positive Hill-Sachs. METHODS: Picture Archiving and Communication System (PACS) records at an urban academic tertiary care musculoskeletal facility from 2014 to 2020 were queried for shoulder MRI in patients aged 0 to 15 years. Patients were excluded if they had a history of glenohumeral instability, fracture, growth arrest, brachial plexus injury, surgery, or infection. All images were independently evaluated by a musculoskeletal fellowship-trained radiologist. Each HH was staged based on skeletal maturity. RESULTS: For both sexes, HHs matured in a predictable manner with increasing chronological age associated with a higher ossification stage. False Hill-Sachs lesions were observed in girls aged 4 to 7 and boys aged 5 to 14, exclusively during stage I to II ossification. CONCLUSIONS: False Hill-Sachs lesions were visualized on MRI in stage I to II proximal humerus ossification. Due to differential timing of skeletal maturation, males present with false Hill-Sachs lesions at a later age than females on average. When interpreting shoulder MRI for glenohumeral instability, clinicians should be cautious of false Hill-Sachs lesions, especially in younger patients with distinct greater tuberosity and HH ossification centers (stage I to II ossification). LEVEL OF EVIDENCE: Level III.

MRI findings of chronic distal tendon biceps reconstruction and associated post-operative findings.

Rupture of the distal biceps tendon is becoming increasingly diagnosed due to an active aging population and an increase in diagnostic imaging opportunities. While physical exam may help in diagnosis, magnetic resonance imaging (MRI) is particularly useful in evaluating chronic rupture. Although partial tears can be managed conservatively, the gold standard treatment for a chronic distal biceps tear is anatomic reinsertion with additional use of an allograft or autograft. No study has highlighted the normal appearance and postsurgical complications seen on MRI associated with allograft or autograft usage. Clinicians and radiologists may be unaware of the normal and abnormal post-operative imaging findings and their clinical relevance. The purpose of this manuscript is to discuss the epidemiology, clinical presentation, and preoperative MRI findings of distal biceps ruptures necessitating reconstruction, to explain distal biceps tendon surgical reconstruction technique with allograft or autograft usage, to display the normal and abnormal post-operative MRI findings, and to review the clinical outcomes associated with the procedure.

Computed Tomography-Based Preoperative Planning Provides a Pathology and Morphology-Specific Approach to Glenohumeral Instability With Bone Loss.

PURPOSE: To use computed tomography (CT) to determine a reproducible method of coracoid measurement to compare the ability of the classic Latarjet technique and the congruent arc modification (CAM) to restore native glenoid diameter and to develop a preoperative planning algorithm for glenoid restoration with a goal of achieving an on-track shoulder. METHODS: Coracoid dimensions were measured on multiplanar reconstructed shoulder CT scans of patients aged 18 to 45 years obtained between December 1, 2019, and March 13, 2020. Patients were excluded if CT demonstrated osteophyte formation, glenoid dysplasia, coracoid fracture, or tumor. The proportion of glenoid diameter able to be restored using classic Latarjet technique and CAM were calculated. A treatment algorithm was proposed considering the amount of bone loss present and coracoid dimensions. RESULTS: Coracoid dimensions of 117 consecutive patients were measured and varied considerably (length: 17.5-31.8 mm, width: 9.1-20.5 mm, thickness: 6.1-15.7 mm). While most patients had harvestable coracoid length ≥20 mm (male: 96.3% vs female: 94.4%, P = .65), only 27.8% of female patients had coracoid thickness ≥10 mm. When comparing Latarjet techniques, there was no difference in the proportion of patients in whom 30% glenoid diameter could be fully restored, but CAM was able to restore at least 35% in more male and female patients (98.8% vs 79.0% and 100% vs 61.1%, respectively, P = .00001). Intra- and inter-rater reliability was excellent ( intraclass correlation coefficient ≥0.950 for all dimensions). CONCLUSIONS: We describe a reliable method of measuring coracoid dimensions for preoperative planning of glenoid restoration. The classic Latarjet technique reliably restores the glenoid anteroposterior diameter with bone loss of up to 30%. The majority of female patients have coracoid thickness <10 mm, which may increase the risk of graft fracture when using CAM. The decision to use the classic Latarjet technique or CAM considers each individual's glenoid and coracoid dimensions with a goal of achieving an on-track shoulder. CLINICAL RELEVANCE: Our reliable method of coracoid measurement demonstrated the differing abilities of the classic Latarjet and CAM to restore the native glenoid diameter. An evidence-based algorithm using these measurements was developed to assist in preoperative planning for glenohumeral instability in the setting of bone loss, with a goal of achieving an on-track shoulder. Alternative techniques may be considered if an on-track shoulder cannot be achieved with Latarjet.

Magnetic Resonance Imaging Findings of Core Muscle Injuries in High Level Athletes.

ABSTRACT: Core muscle injuries are common injuries in athletes involved in high speed side-to-side acceleration movements. The term core muscle injury encapsulates several different injuries that occur in the pelvic region that have similar presentations. Along with a good history and physical examination, magnetic resonance imaging (MRI) can be a helpful tool in the diagnostic process. Correct orientation and protocols are needed to show the correct anatomy with an MRI. Furthermore, to determine the exact etiology of the core muscle injury, it is important to know which structures are likely to be involved and be able to recognize the patterns of injury on imaging.

MRI of Superior Capsular Reconstruction.

Massive irreparable rotator cuff tears can be a challenging problem for arthroscopists in the perioperative setting because the typical treatment, reverse total shoulder arthroplasty, may not be the best option for all patients. Superior capsular reconstruction (SCR) is an advancing treatment option for patients with rotator cuff tears that are neither amenable to primary repair nor ideal for arthroplasty. Patient selection, which is strongly dependent on preoperative imaging findings, is an important step in obtaining favorable surgical outcomes. The tissue quality and tear type are particularly important when considering SCR for a patient. When unsuccessful SCR is suspected, postoperative MRI of the shoulder offers the surgeon and radiologist a means of evaluating the integrity and fixation of the graft. Fluid-sensitive MRI sequences are best for examining the final SCR construct, with high-signal-intensity fluid interruptions within the graft and the presence or worsening of shoulder arthropathy indicating graft failure. The indications for SCR are discussed, and the normal postoperative MRI findings after SCR are described in this review. In addition, the common types of SCR graft failure and associated imaging findings are described and illustrated. ©RSNA, 2020.

Normal Glenoid Ossification in Pediatric and Adolescent Shoulders Mimics Bankart Lesions: A Magnetic Resonance Imaging-Based Study.

PURPOSE: The purpose of this descriptive study was to define patterns of ossification and fusion of growth centers around the pediatric and adolescent glenoid as a function of age using 3-dimensional, frequency-selective, fat-suppressed spoiled gradient recalled echo magnetic resonance (MR) imaging sequences, with a particular focus on the anterior glenoid rim because of its clinical relevance as a potential confounder of glenohumeral instability. METHODS: Picture Archiving and Communication System records at an urban academic tertiary care orthopaedic facility from October 2005 to December 2018 were queried for shoulder MRI in patients aged 9 to 17 years. Patients were excluded if they had any diagnoses that could alter glenoid development. All images were independently evaluated by a musculoskeletal fellowship-trained radiologist. Secondary ossification centers were characterized as cartilage anlage, ossified, or fused at 3 anatomic sites: the anterior glenoid rim, coracoid, and superior glenoid rim. RESULTS: A total of 250 MR examinations (143 males, 107 females) were assessed in this study. The glenoid develops in a predictably sequential manner with ossification at the anterior glenoid rim lagging behind the coracoid and superior glenoid rim. The earliest age of anterior glenoid rim ossification was 11 years for both males (range 11-17) and females (range 11-12). Anterior glenoid rim ossification peaked at age 16 among males (34.8%, 8/23) and age 11 among females (27.3%, 3/11). CONCLUSIONS: Glenoid ossification and fusion progress in a predictable and chronological manner. This pattern should be used as a guideline when interpreting pediatric shoulder MRI examinations. In particular, an anterior glenoid ossification center should not be confused with an anterior glenoid injury (e.g., Bankart lesion), particularly in males 11 to 17 years old and females 11 to 12 years old. LEVEL OF EVIDENCE: IV (case series).

Non-treatment of stable ramp lesions does not degrade clinical outcomes in the setting of primary ACL reconstruction.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of various methods of treatment of stable and unstable ramp lesions compared to patients with no meniscal pathology at the time of primary ACL reconstruction. METHODS: All patients with a preoperative MRI performed at our facility who were enrolled in an institutional ACL registry and 1-year clinical follow-up were identified. A musculoskeletal radiologist reviewed preoperative MRI scans for evidence of a ramp lesion. Ramp lesions were classified as stable if a peripheral tear of the posterior horn of the medial meniscus was identified by MRI, but did not displace into the medial compartment with anteriorly directed probing at the time of surgery. Ramp lesions were classified as unstable if a tear was identified by preoperative MRI at the meniscocapsular junction and the meniscus was displaceable into the medial compartment with probing. Reoperation rates for ACL graft failure or recurrent medial meniscus pathology were collected. Patient-reported outcome scores (IKDC, SF12 PCS, SF12 MCS, and Marx Activity scale) were recorded at baseline and final follow-up. RESULTS: A total of 162 patients were included in the analysis with median 2-year (range 1-5 years) clinical follow-up. Patients with a repaired unstable ramp lesion had a significantly higher likelihood of reoperation for recurrent medial meniscus pathology than patients without meniscal pathology at the time of index surgery. Patients with an untreated stable ramp lesion had a similar rate of reoperation when compared to patients without meniscal pathology. At final follow-up, there was no difference between groups in IKDC score, SF12 PCS/MCS, or Marx activity score or change in any score. CONCLUSIONS: Patients with untreated stable ramp lesions have similar clinical outcomes at median 2-year (range 1-5 years) follow-up when compared to patients without a ramp lesion. Treatment of stable ramp lesions at the time of ACL reconstruction does not have clinical benefit. LEVEL OF EVIDENCE: III.

Total Knee Arthroplasty: Diagnostic Accuracy of Patterns of Synovitis at MR Imaging.

Purpose To determine the diagnostic accuracy of magnetic resonance (MR) imaging for differentiating synovial patterns in patients with total knee arthroplasty (TKA), whether diagnostic accuracy differs in index versus revision TKA, and interobserver and intraobserver reliability for assessment of synovial patterns at MR imaging. Materials and Methods This retrospective cross-sectional study included 108 consecutive patients with TKAs who underwent MR imaging within 1 year prior to revision surgery from 2012 to 2014. Institutional review board approval was obtained, with waiver of the need to obtain informed consent. MR images were reviewed, and cases were qualitatively categorized by the appearance of the synovium as one of the following: frondlike and hypertrophied (particle-induced synovitis), lamellated and hyperintense (infection), and a homogeneous effusion with the signal intensity of fluid (nonspecific synovitis). The MR imaging appearance was compared with surgical and microbiology reports as the reference standard to determine the sensitivity, specificity, and positive and negative predictive values for the index TKA and revision TKA cohorts. Results For all patients combined, MR imaging had 0.907-0.930 sensitivity and 0.723-0.738 specificity for a surgical diagnosis of complications related to polyethylene wear (including osteolysis and loosening); 0.652-0.783 sensitivity and 0.976-0.988 specificity for infection; and 0.643-0.667 sensitivity and 0.894-0.939 specificity for stiffness, instability, and nonspecific pain. Diagnostic accuracy was higher in the index TKA cohort than in the revision TKA cohort. Interobserver and intraobserver reliabilities were almost perfect (κ = 0.82 and κ = 0.83, respectively). Conclusion MR imaging can help distinguish qualitative differences in the appearance of the synovium in TKA between particle-induced synovitis, infection, and nonspecific synovitis, with almost perfect interobserver and intraobserver reliability. Diagnostic accuracy is higher for index TKA than for revision TKA. © RSNA, 2016.

MRI Evaluation of Femoroacetabular Impingement After Hip Preservation Surgery.

OBJECTIVE: This article reviews the surgical treatment options for femoroacetabular impingement (FAI), including labral repair and osteochondroplasty, and the expected postoperative appearance on MRI. Complications, including residual osseous deformities, chondral injury, adhesions, femoral neck stress fractures, osteonecrosis, instability, malpositioned suture anchors, and infection, will also be discussed. CONCLUSION: Knowledge of the surgical treatment of FAI can assist in improving our understanding of the expected postoperative MRI appearance and in evaluating surgical complications.

Optimal detection of scapholunate ligament tears with MRI.

Background Scapholunate interosseous ligament (SLIL) injuries can often be difficult to detect using magnetic resonance imaging (MRI), especially with older 1.0 and 1.5 Tesla magnets. Wrist arthroscopy is the gold standard for diagnosis of SLIL injuries, but is an invasive procedure with associated risks. Purpose To assess whether SLIL injuries can be more accurately detected using axial MRI sequences instead of coronal sequences. Material and Methods An institutional review board approved retrospective analysis of arthroscopic wrist surgeries performed at our institution. Patients that had a preoperative MRI performed at our university center using a 1.5 Tesla scanner with a dedicated wrist coil were included in the study. Three fellowship-trained musculoskeletal radiologists reviewed the axial sequences and coronal sequences independently. The accuracy of the coronal and axial sequences was compared with the arthroscopic/surgical findings. Result Twenty-six patients met the inclusion criteria. The sensitivity for SLIL tears was 79% and 65% for the axial and coronal sequences, respectively. The specificity was 82% for the axial and 69% for the coronal sequences, respectively. The positive and negative predictive values for the axial sequences were 76% and 84% respectively, compared to 68% and 71% for the coronal sequences, a statistically significant difference. Conclusion SLIL tears are more readily detectable on axial MRI sequences than coronal. Clinically, patients with radial-sided wrist pain and suspicion for SLIL tears should have the axial sequences scrutinized carefully. An otherwise normal study with the axial sequence being degraded by motion or other MRI artifacts might need repeat imaging.

Segond Fractures Can Be Identified With Excellent Accuracy Utilizing Deep Learning on Anteroposterior Knee Radiographs.

Purpose: To develop a deep learning model for the detection of Segond fractures on anteroposterior (AP) knee radiographs and to compare model performance to that of trained human experts. Methods: AP knee radiographs were retrieved from the Hospital for Special Surgery ACL Registry, which enrolled patients between 2009 and 2013. All images corresponded to patients who underwent anterior cruciate ligament reconstruction by 1 of 23 surgeons included in the registry data. Images were categorized into 1 of 2 classes based on radiographic evidence of a Segond fracture and manually annotated. Seventy percent of the images were used to populate the training set, while 20% and 10% were reserved for the validation and test sets, respectively. Images from the test set were used to compare model performance to that of expert human observers, including an orthopaedic surgery sports medicine fellow and a fellowship-trained orthopaedic sports medicine surgeon with over 10 years of experience. Results: A total of 324 AP knee radiographs were retrieved, of which 34 (10.4%) images demonstrated evidence of a Segond fracture. The overall mean average precision (mAP) was 0.985, and this was maintained on the Segond fracture class (mAP = 0.978, precision = 0.844, recall = 1). The model demonstrated 100% accuracy with perfect sensitivity and specificity when applied to the independent testing set and the ability to meet or exceed human sensitivity and specificity in all cases. Compared to an orthopaedic surgery sports medicine fellow, the model required 0.3% of the total time needed to evaluate and classify images in the independent test set. Conclusions: A deep learning model was developed and internally validated for Segond fracture detection on AP radiographs and demonstrated perfect accuracy, sensitivity, and specificity on a small test set of radiographs with and without Segond fractures. The model demonstrated superior performance compared with expert human observers. Clinical Relevance: Deep learning can be used for automated Segond fracture identification on radiographs, leading to improved diagnosis of easily missed concomitant injuries, including lateral meniscus tears. Automated identification of Segond fractures can also enable large-scale studies on the incidence and clinical significance of these fractures, which may lead to improved management and outcomes for patients with knee injuries.

Transosseous Repair of Isolated Posterior Medial Meniscal Root Injuries in Children and Adolescents.

The meniscal roots are critically important for maintaining knee stability, functional load distribution, and proper knee kinematics. Although adult meniscal root injuries have been a topic of increasing research, medial meniscus injuries also occur in pediatric and adolescent patients, with up to 2% of meniscal injuries involving root attachments. The purpose of this Technical Note is to demonstrate the transosseous repair of isolated posterior medial meniscal root injuries in children and adolescents, including tear visualization on magnetic resonance imaging and during arthroscopy, operative technique, and postoperative management.

Current Concepts in the Measurement of Glenohumeral Bone Loss.

PURPOSE: The extent of glenohumeral bone loss seen in anterior shoulder dislocations plays a major role in guiding surgical management of these patients. The need for accurate and reliable preoperative assessment of bone loss on imaging studies is therefore of paramount importance to orthopedic surgeons. This article will focus on the tools that are available to clinicians for quantifying glenoid bone loss with a focus on emerging trends and research in order to describe current practices. RECENT FINDINGS: Recent evidence supports the use of 3D CT as the most optimal method for quantifying bone loss on the glenoid and humerus. New trends in the use of 3D and ZTE MRI represent exciting alternatives to CT imaging, although they are not widely used and require further investigation. Contemporary thinking surrounding the glenoid track concept and the symbiotic relationship between glenoid and humeral bone loss on shoulder stability has transformed our understanding of these lesions and has inspired a new focus of study for radiologists and orthopedist alike. Although a number of different advanced imaging modalities are utilized to detect and quantify glenohumeral bone loss in practice, the current literature supports 3D CT imaging to provide the most reliable and accurate assessments. The emergence of the glenoid track concept for glenoid and humeral head bone loss has inspired a new area of study for researchers that presents exciting opportunities for the development of a deeper understanding of glenohumeral instability in the future. Ultimately, however, the heterogeneity of literature, which speaks to the diverse practices that exist across the world, limits any firm conclusions from being drawn.

Repair of gluteus medius tears with bioinductive collagen patch augmentation: initial evaluation of safety and imaging.

The purpose of this study was to perform an initial, prospective evaluation of imaging findings and outcomes after open surgical repair of gluteus medius tendon tears with bioinductive collagen patch augmentation. A prospective study was performed of patients with clinical and magnetic resonance imaging (MRI) evidence of symptomatic gluteus medius tears who underwent open, double-row suture anchor repair with bioinductive bovine collagen patch augmentation. Preoperative and 6-month postoperative MRIs were reviewed by a fellowship-trained musculoskeletal radiologist, and outcome scores were recorded preoperatively and 6 months postoperatively [Hip Outcome Score (HOS) Sport; HOS Activities of Daily Living (HOS ADL); Modified Harris Hip Score (mHHS) and International Hip Outcomes Tool (iHOT-33)]. Nine patients, four high-grade tears (≥50% tendon thickness) and five low-grade tears (<50% thickness) underwent surgical repair. At 6 months, 7/9 (77.8%) of tendons were qualitatively classified as completely healed on MRI, with no complications. Mean tendon thickness increased significantly: mediolateral dimension by 5.8 mm (P < 0.001), anteroposterior dimension by 4.1 mm (P = 0.02) and cross-sectional area (CSA) by 48.4 mm2 (P = 0.001). Gluteus medius and minimus CSA did not change significantly (P > 0.05). Patients demonstrated improvements in mean scores for HOS ADL, mHHS and iHOT that met defined minimum clinically important differences (P < 0.05). Open surgical repair of gluteus medius tendon tears with bioinductive collagen patch augmentation is safe and associated with increased tendon thickness on postoperative MRI. Early outcome scores are encouraging and should be evaluated after patients have completed postoperative rehabilitation to measure the whole effect of treatment.

Articular Cartilage Repair in the Knee: Postoperative Imaging.

Diagnostic and therapeutic advancements have improved clinical outcomes for patients with focal chondral injuries of the knee. An increased number and complexity of surgical treatment options have, in turn, resulted in a commensurate proliferation of patients requiring postoperative evaluation and management. In addition to patient-reported clinical outcomes, magnetic resonance imaging (MRI) offers clinicians with noninvasive, objective data to assist with postoperative clinical decision making. However, successful MRI interpretation in this setting is clinically challenging; it relies upon an understanding of the evolving and procedure-specific nature of normal postoperative imaging. Moreover, further research is required to better elucidate the correlation between MRI findings and long-term clinical outcomes. This article focuses on how specific morphologic features identified on MRI can be utilized to evaluate patients following the most commonly performed cartilage repair surgeries of the knee.

Patterns of Articular Cartilage Thickness in Pediatric and Adolescent Knees: A Magnetic Resonance Imaging-Based Study.

PURPOSE: To establish normative values for articular cartilage thickness in pediatric and adolescent knees using magnetic resonance imaging (MRI) and investigate for any associations with age and skeletal maturity. METHODS: MRI scans were analyzed in patients 7 to 18 years old without osteochondral lesions, chondral wear/pathology, intra-articular fractures, or history of knee surgery. Measurements of articular cartilage thickness at the patella (medial facet, lateral facet, median ridge), femur (medial condyle, lateral condyle, lateral trochlea), and tibia (medial plateau, lateral plateau) were made on axial, coronal, and sagittal MRI. Descriptive statistics were used to calculate mean cartilage thickness by age and sex. Analysis of variance with repeated measures, analysis of covariance, independent samples t test, and linear regression were performed to determine differences in mean cartilage thickness by anatomic location, sex, physeal status, and age, respectively. RESULTS: A total of 240 knee MRI scans were included. Articular cartilage was thickest at the patella and did not vary with age or skeletal maturity. On the femur, articular cartilage was thickest at the lateral trochlea with mean cartilage thickness of 4.4 ± 1.4 mm in male patients and 3.6 ± 1.3 mm in female patients (P < .001). Patients with open distal femoral physes had significantly thicker cartilage at the medial femoral condyle, lateral femoral condyle, and lateral trochlea compared to patients with closing/closed physes (P < .001). Linear regression analysis revealed a significant inverse association between cartilage thickness at the femur and age. CONCLUSIONS: In pediatric and adolescent knees, articular cartilage is thickest at the patella, where it does not strongly correlate with age. In contrast, there is a strong inverse association between increasing age and articular cartilage thickness of the distal femoral condyles. CLINICAL RELEVANCE: The longitudinal reference data presented in this study can aid in pre-operative interpretation of knee cartilage under pathologic conditions in pediatric and adolescent patients.

The Incidence of Kaplan Fiber Injury Associated With Acute Anterior Cruciate Ligament Tear Based on Magnetic Resonance Imaging.

BACKGROUND: Kaplan fibers are distinct deep layers of the distal iliotibial band (ITB) that anchor the ITB to the distal femur and have a role in rotational stability of the knee. However, the incidence of Kaplan fiber injury in the setting of acute anterior cruciate ligament (ACL) tear is unknown. PURPOSE: To determine the reliability of identifying and evaluating Kaplan fibers on magnetic resonance imaging (MRI) examinations based on previously reported characteristics and to report on the incidence of combined ACL and Kaplan fiber injuries based on MRI examinations. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Patients with an acute primary ACL tear who obtained a postinjury MRI scan at our institution and were treated with ACL reconstruction between January 1, 2007, and May 31, 2012, were identified from an institutional registry. Each patient's postinjury MRI scan was reviewed by 2 musculoskeletal radiologists, who identified Kaplan fibers and graded them as intact, injured, or not visualized. Intrarater reliability was measured using the intraclass correlation coefficient (ICC), and interrater reliability was measured using the kappa statistic. RESULTS: A total of 72 patients were identified. For the proximal Kaplan fibers, 50% versus 58% were identified as injured, 32% versus 29% were identified as intact, and 18% versus 13% were not visualized by radiologist 1 and 2, respectively. For the distal Kaplan fibers, 46% versus 60% were identified as injured, 43% versus 28% were identified as intact, and 11% versus 12% were not visualized by radiologist 1 and 2, respectively. The ICC intrarater reliability measurements were 0.89 (95% CI, 0.83-0.93) for proximal Kaplan fibers and 0.66 (95% CI, 0.51-0.78) for distal Kaplan fibers. The interrater reliability measurements for both radiologists showed substantial agreement (kappa = 0.7) for proximal Kaplan fibers and moderate agreement (kappa = 0.51) for distal Kaplan fibers. CONCLUSION: Kaplan fibers were visualized on MRI studies in the majority of cases, with substantial reliability for the proximal fibers and moderate reliability for the distal fibers. There was an associated injury to either the proximal or distal or both Kaplan fibers in the majority of acute primary ACL tears.

Lumbosacral Transitional Vertebrae Predict Inferior Patient-Reported Outcomes After Hip Arthroscopy.

BACKGROUND: While the association between spinal disease and hip arthroplasty outcomes has been well studied, there is less known about the effect of spinal pathology in hip arthroscopy (HA) outcomes. Lumbosacral transitional vertebrae (LSTV) are anatomic variations where caudal vertebrae articulate or fuse with the sacrum or ilium. HYPOTHESIS: LSTV can lead to inferior outcomes after HA for treatment of femoroacetabular impingement. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We retrospectively reviewed the prospectively collected Hip Arthroscopy Database at our institution for patients with LSTV who underwent HA between 2010 and 2017. A total of 62 patients with LSTV were identified and then matched to controls. Patient-reported outcome measures (PROMs) were collected, including the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports, and the 33-item International Hip Outcome Tool. They were collected at 4 time points: preoperatively and 5 to 11 months, 12 to 23 months, and 24 to 35 months postoperatively. Longitudinal analysis of the PROMs was done using generalized estimating equation modeling. Additionally, alpha angles were measured from preoperative radiographic data. RESULTS: Preoperatively, there was no significant difference between patients with and without LSTV on 3 of the 4 PROMs; however, patients with LSTV did have significantly lower preoperative scores than controls for the Hip Outcome Score-Activities of Daily Living (P = .029). Patients with LSTV reported significantly lower scores on all 4 PROMs at each postoperative time point. Radiographic data showed no significant difference in alpha angles across cohorts. When LSTV were compared by Castellvi type, types 3 and 4 tended to have lower scores than types 1 and 2; however, these comparisons were not significant. CONCLUSION: The data support our hypothesis that HA has less benefit in patients with LSTV as compared with patients without LSTV. In patients with LSTV, careful evaluation of the anomaly is recommended to help guide surgical counseling and manage expectations.