Common animal models lack a distinct glenoid labrum: a comparative anatomy study

Purpose Development and validation of an animal model of labral healing would facilitate translation of novel surgical and biological strategies to improve glenolabral healing. The purpose of this study was to characterize the anatomic and histological properties of the shoulder labrum in rat, rabbit, dog, pig, goat, and humans. Given the demonstrated similarities in size and structural morphology in other joints, it was hypothesized that the goat glenoid with surrounding capsulolabral complex would most closely resemble that of humans in terms of dimensions and structure, as observed grossly and histologically. Methods Cadaveric glenohumeral joints from rats (n = 8), New Zealand white rabbits (n = 13), Mongrel dogs (n = 9), Spanish goats (n = 10), Yorkshire pigs (n = 10), and humans (n = 9) were freshly harvested. Photographs were taken of the glenoid with its surrounding capsulolabral complex. Linear dimensions of the glenoid articular surface were measured. It was determined where the capsulolabral complex was continuous with, or recessed from, the articular glenoid surface. The glenoid was divided into 6 equal segments radiating out toward 12, 2, 4, 6, 8, and 10 o’clock positions. Samples were sectioned and stained with Safranin O/Fast green and Mallory Trichrome. Insertion of the capsulolabral tissue onto the glenoid was qualitatively assessed and compared with gross morphology. Results Dimensions of the goat glenoid most closely paralleled dimensions of the human glenoid. A capsulolabral complex was continuous with the glenoid surface from ~ 9 to 12 o’clock in the rats, 7 to 12 o’clock in rabbits, 5 to 12 o’clock in the dogs, and 9 to 12 o’clock in goats, 6 to 12 o’clock in pigs, and 2 to 8 o’clock in humans. In contrast to humans, no other species demonstrated an organized fibrocartilaginous labrum either macroscopically or histologically. Conclusion The animals in the present study did not possess a discrete fibrocartilaginous labrum by gross or histological evaluation, as directly compared to humans. While models using these animals may be acceptable for examining other shoulder pathologies, they are not adequate to evaluate labral pathology. Level of evidence Basic Science Study; Anatomy and Histology; Cadaveric Animal Model.

Arthroscopic Bennett Lesion Resection: A Novel Technique

Background: Bennett lesion is ossification of the posterior inferior glenohumeral ligament complex. Though often asymptomatic, these lesions can become painful and interfere with throwing ability. Indications: The Bennett lesion is relatively common among elite throwers, present in 22% to 25% of asymptomatic pitchers. Suggested causes of this lesion include traction on the posterior joint and posterior impingement in the late cocking phase. These lesions can become painful due to displacement and irritation of the joint capsule and axillary nerve. Therefore, efficient arthroscopic treatment of symptomatic lesions is essential. Technique Description: The patient is positioned in the lateral decubitus position, and the glenohumeral joint is accessed via posterior and anterior portals. Once the lesion is identified, it may be probed and debrided via the posterior portal. A posterior capsular release is performed, and 4.0 mm burr resection of the lesion is started, viewing from the anterior portal with a 70° arthroscope. Direct visualization through the posterior portal can be used to verify complete lesion resection. If there is a true tear of the posterior labrum, this can be repaired with a knotless suture anchor back to the glenoid, but usually there is delamination that can be left alone after addressing the Bennett lesion. Results: We have found good success treating Bennett lesions via the above technique. This is supported by previous literature as well, with return to preinjury levels ranging from 69% to 85% following arthroscopic resection. Discussion/Conclusion: Four diagnostic criteria have been described to ensure accurate diagnosis: detection of a bony spur at the posterior glenoid rim on plain x-ray films, best seen on Stryker notch and Bennett view; posterior shoulder pain while throwing; tenderness at the posteroinferior aspect of the glenohumeral joint; and improvement in pain following lidocaine injection. Magnetic resonance imaging is also an excellent diagnostic tool to detect early enthesopathic changes in the posterior glenoid or periosteum, as well as labral pathology. Following arthroscopic resection, 88% of patients were satisfied with their treatment when using these diagnostic criteria. Accurate diagnosis and efficient treatment of Bennett lesions are imperative in the throwing athlete, and when performed correctly, our technique provides significant and lasting improvement for patients.

Achieving Successful Outcomes in High-Level Athletes With Borderline Hip Dysplasia Undergoing Hip Arthroscopy With Capsular Plication and Labral Preservation: A Propensity-Matched Controlled Study

Background: Return to sports (RTS) rates and patient-reported outcomes (PROs) after hip arthroscopy in athletes with borderline dysplasia (BD) have not been established. Purpose: (1) To report minimum 2-year PROs and RTS rates in high-level athletes with BD who underwent hip arthroscopy for labral pathology in the setting of microinstability and (2) to compare clinical results with those of a matched control group of athletes with normal acetabular coverage. Study Design: Cohort study; Level of evidence, 3. Methods: Data were reviewed for surgery performed between January 2012 and July 2018. Patients were considered eligible if they received a primary hip arthroscopy in the setting of BD (lateral center-edge angle, 18°-25°) and competed in professional, collegiate, or high school sports. Inclusion criteria included preoperative and minimum 2-year follow-up scores for the modified Harris Hip Score, Non-arthritic Hip Score, Hip Outcome Score–Sport Specific Subscale, and visual analog scale for pain. Athletes with BD were matched to a control group of athletes with normal acetabular coverage (lateral center-edge angle, 25°-40°). Results: A total of 65 patients with BD were included in the study with a mean ± standard deviation follow-up of 47.5 ± 20.4 months. Athletes with BD showed significant improvement in all outcome measures recorded, demonstrated high RTS rates (80.7%), and achieved the minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) for the Hip Outcome Score–Sport Specific Subscale at high rates (MCID, 90.8%; PASS, 75.4%). When compared with a propensity-matched control group with normal acetabular coverage, capsular plication was performed more commonly in the BD group (93.8% vs 82.7%; P = .037). PROs and RTS, PASS, and MCID rates were similar between the BD and control groups ( P > .05). Conclusion: High-level athletes with BD who undergo primary hip arthroscopy for labral pathology in the setting of microinstability may expect favorable PROs and RTS rates at minimum 2-year follow-up. These results were comparable with those of a control group of athletes with normal coverage.

Posterior shoulder labrocapsular structures in all aspects; 3D volumetric MR arthrography study

Pathologies of the posterior labrocapsular structures of the shoulder joint are far less common than anterior labrocapsuloligamentous lesions. Most of these pathologies have been associated with traumatic posterior dislocation. A smaller portion of the lesions include posterior extension of superior labral anteroposterior lesions, posterior superior internal impingement, and damage to the posterior band of the inferior glenohumeral ligament. Labrocapsular anatomic variations of the posterior shoulder joint can mimic labral pathology on conventional MR and occasionally on MR arthrographic images. Knowledge of this variant anatomy is key to interpreting MR images and studying MR arthrography of the posterior labrocapsular structure to avoid misdiagnosis and unnecessary surgical procedures. In this article, we review normal and variant anatomy of the posterior labrocapsular structure of the shoulder joint based on MR arthrography and discuss how to discriminate normal anatomic variants from labrocapsular damage.

Preoperative MRI and Intraoperative Arthroscopic Evaluation of Chondral Pathology at the Hip Chondrolabral Junction

Background: Previous literature has found that hip magnetic resonance imaging (MRI) has lower accuracy and reliability in preoperative diagnosis of cartilage and labral pathology compared with knee and shoulder MRI. This is a notable limitation, as MRI findings play a significant role in the determination for surgical intervention in femoroacetabular impingement syndrome (FAIS) and aid in surgical planning, intraoperative cartilage management, and in postoperative rehabilitation expectations. Indications: Hip arthroscopy is most commonly utilized for the treatment of FAIS and associated labral tears and chondral pathology of varying grades, particularly at the chondrolabral junction. Given the difficulty in assessing chondrolabral pathology on preoperative MRI, we present our preferred method of correlating MRI to intraoperative findings at the chondrolabral junction. Technique Description: Using preoperative MRI and the Outerbridge classification system, we describe our method to assess cartilage injuries and chondrolabral junction pathology in patients who undergo hip arthroscopy for FAIS. We correlate chondral injuries with preoperative MRI to aid surgeons in interpreting the degree of chondral injury from MRI and corresponding surgical findings. Results: Given that MRI of the hip is neither as accurate nor as reliable as MRI of the knee or shoulder, an understanding of how to correlate preoperative MRI with intraoperative appearance can better prepare the surgeon for findings at the chondrolabral junction of the hip. The absence of findings on MRI does not rule out the possibility of cartilage or labral pathology. Discussion/Conclusion: Intraoperatively, hip cartilage is assessed using either the Outerbridge or Beck classification systems. These classification systems require direct visualization of the hip joint, and full assessment of the chondrolabral junction and associated pathology may not be possible until intra-articular work is complete. While MRI evaluation of the hip is difficult due to the depth of the hip joint, location of the hip relative to the MR magnet, and thinness of the acetabular cartilage, it is a useful tool for preoperative hip joint cartilage assessment, though not as accurate as knee and shoulder MRIs. Understanding the correlation between preoperative hip MRI and intraoperative chondrolabral pathology can aid the surgeon in preparation for hip arthroscopy in the treatment of FAIS.

Pediatric and Adolescent Shoulder Instability: Does Insurance Status Predict Delays in Care, Outcomes, and Complication Rate?

Background: Recurrent shoulder instability results from overuse injuries that are often associated with athletic activity. Timely diagnosis and treatment are necessary to prevent further dislocations and secondary joint damage. In pediatric and adolescent patients, insurance status is a potential barrier to accessing timely care that has not yet been explored. Purpose: To examine the effect of insurance status on access to clinical consultation, surgical intervention, and surgical outcome of pediatric and adolescent patients with recurrent shoulder instability. Study Design: Cohort study; Level of evidence, 3. Methods: We conducted a retrospective review of pediatric and adolescent patients who were treated at a single tertiary children’s hospital for recurrent shoulder instability between 2011 and 2017. Patients were sorted into private and public insurance cohorts. Dates of injury, consultation, and surgery were recorded. Number of previous dislocations, magnetic resonance imaging (MRI) results, surgical findings, and postoperative complications were also noted. Delays in care were compared between the cohorts. The presence of isolated anterior versus complex labral pathology as well as bony involvement at the time of surgery was recorded. The incidences of labral pathology and secondary bony injury were then compared between the 2 cohorts. Postoperative notes were reviewed to compare rates of repeat dislocation and repeat surgery. Results: A total of 37 patients had public insurance, while 18 patients had private insurance. Privately insured patients were evaluated nearly 5 times faster than were publicly insured patients ( P < .001), and they obtained MRI scans over 4 times faster than did publicly insured patients ( P < .001). Publicly insured patients were twice as likely to have secondary bony injuries ( P = .016). Postoperatively, a significantly greater number (24.3%) of publicly insured patients experienced redislocation versus the complete absence of redislocation in the privately insured patients ( P = .022). Conclusion: Public insurance status affected access to care and was correlated with the development of secondary bony injury and a higher rate of postoperative dislocations. Clinicians should practice with increased awareness of how public insurance status can significantly affect patient outcomes by delaying access to care—particularly if delays lead to increased patient morbidity and health care costs.