Epidemiology of the Frequency, Etiology, Direction, and Severity (FEDS) system for classifying glenohumeral instability.

HYPOTHESIS: The purpose of this multicenter epidemiologic study was to determine the distribution of patients within the Frequency, Etiology, Direction, and Severity (FEDS) classification system to determine which categories are of clinical importance. METHODS: Shoulder instability patients were identified using International Classification of Diseases, Ninth Revision coding data from 3 separate institutions from 2005-2010. Data were collected retrospectively. Details of instability were recorded in accordance with the FEDS classification system. Each patient was assigned a classification within the FEDS system. After all patients were assigned to a group, each group was individually analyzed and compared with the other groups. RESULTS: There are a total of 36 possible combinations within the FEDS system. Only 16 categories were represented by at least 1% of our patient population. Six categories captured at least 5% of all patients with shoulder instability. Only 2 categories represented greater than 10% of the population: solitary, traumatic, anterior dislocation, with 95 patients (24.8%), and occasional, traumatic, anterior dislocation, with 63 patients (16.4%). CONCLUSIONS: There are 16 categories within the FEDS classification that are clinically significant. Solitary, traumatic, anterior dislocation and occasional, traumatic, anterior dislocation were the most frequently observed in our cohort.

Arthroscopy Up to Date: Anterior Cruciate Ligament Anatomy.

PURPOSE: To categorize and summarize up-to-date anterior cruciate ligament (ACL) research published in Arthroscopy and The American Journal of Sports Medicine and systematically review each subcategory, beginning with ACL anatomy. METHODS: After searching for "anterior cruciate ligament" OR "ACL" in Arthroscopy and The American Journal of Sports Medicine from January 2012 through December 2014, we excluded articles more pertinent to ACL augmentation; open growth plates; and meniscal, chondral, or multiligamentous pathology. Studies were subcategorized for data extraction. RESULTS: We included 212 studies that were classified into 8 categories: anatomy; basic science and biomechanics; tunnel position; graft selection; graft fixation; injury risk and rehabilitation; practice patterns and outcomes; and complications. Anatomic risk factors for ACL injury and post-reconstruction graft failure include a narrow intercondylar notch, low native ACL volume, and increased posterior slope. Regarding anatomic footprints, the femoral attachment is 43% of the proximal-to-distal lateral femoral condylar length whereas the posterior border of the tendon is 2.5 mm from the articular margin. The tibial attachment of the ACL is two-fifths of the medial-to-lateral interspinous distance and 15 mm anterior to the posterior cruciate ligament. Anatomic research using radiology and computed tomography to evaluate ACL graft placement shows poor interobserver and intraobserver reliability. CONCLUSIONS: With a mind to improving outcomes, surgeons should be aware of anatomic risk factors (stenotic femoral notch, low ligament volume, and increased posterior slope) for ACL graft failure, have a precise understanding of arthroscopic landmarks identifying femoral and tibial footprint locations, and understand that imaging to evaluate graft placement is unreliable. LEVEL OF EVIDENCE: Level III, systematic review of Level III evidence.

Advantages and Disadvantages of Transtibial, Anteromedial Portal, and Outside-In Femoral Tunnel Drilling in Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: Controversy exists regarding the best method for creating the knee anterior cruciate ligament (ACL) femoral tunnel or socket. The purpose of this study was to systematically review the risks, benefits, advantages, and disadvantages of the endoscopic transtibial (TT) technique, anteromedial portal technique, outside-in technique, and outside-in retrograde drilling technique for creating the ACL femoral tunnel. METHODS: A PubMed search of English-language studies published between January 1, 2000, and February 17, 2014, was performed using the following keywords: "anterior cruciate ligament" AND "femoral tunnel." Included were studies reporting risks, benefits, advantages, and/or disadvantages of any ACL femoral technique. In addition, references of included articles were reviewed to identify potential studies missed in the original search. RESULTS: A total of 27 articles were identified through the search. TT technique advantages include familiarity and proven long-term outcomes; disadvantages include the risk of nonanatomic placement because of constrained (TT) drilling. Anteromedial portal technique advantages include unconstrained anatomic placement; disadvantages include technical challenges, short tunnels or sockets, and posterior-wall blowout. Outside-in technique advantages include unconstrained anatomic placement; disadvantages include the need for 2 incisions. Retrograde drilling technique advantages include unconstrained anatomic placement, as well as all-epiphyseal drilling in skeletally immature patients; disadvantages include the need for fluoroscopy for all-epiphyseal drilling. CONCLUSIONS: There is no one, single, established "gold-standard" technique for creation of the ACL femoral socket. Four accepted techniques show diverse and subjective advantages, disadvantages, risks, and benefits. LEVEL OF EVIDENCE: Level V, systematic review of Level II through V evidence.

Biomechanical Analysis of Internal Bracing for Treatment of Medial Knee Injuries.

The internal brace technique uses a high-strength suture tie to augment injured tissues or a primary repair, allowing early rehabilitation. Anatomic repair with internal bracing is a novel and promising treatment for femoral-sided medial knee avulsion injuries of the medial collateral ligament and posterior oblique ligament. Unfortunately, biomechanical and clinical data are lacking. To evaluate this technique compared with other treatment options, 3 assays of 9 cadaveric matched pairs (54 knees) were tested to failure at 30° under valgus load in a biomechanical testing apparatus. The primary outcome measure was moment at failure (Nm), with secondary outcome measures of stiffness (Nm/°), valgus angulation at 10 Nm (°), and valgus angulation at failure (°). Repair with internal bracing was compared with the intact state, repair alone, and allograft reconstruction. The mean moment to failure (62.5±24.9 Nm) for internal bracing was significantly lower than that for intact specimens (107.2±39.7 Nm) (P=.009). Mean moment to failure and valgus angle at failure were significantly greater for internal bracing (95±31.9 Nm) than for repair (73.4±27.6 Nm) (P=.05). Internal bracing was similar to reconstruction for the primary outcome measure (53.5±26.3 Nm vs 66.9±28.8 Nm) (P=.227) and for all secondary outcome measures. These findings indicate that posteromedial knee repair with internal bracing for femoral-sided avulsions is superior to repair alone and is similar to allograft reconstruction for all parameters measured; however, this technique did not recreate biomechanical properties equivalent to the intact state. [Orthopedics. 2016; 39(3):e532-e537.].

Predictors for Surgery in Shoulder Instability: A Retrospective Cohort Study Using the FEDS System.

BACKGROUND: Shoulder instability is a common cause of pain and dysfunction in young, active patients. While studies have analyzed risk factors for recurrent instability and failure after instability surgery, few have examined which variables are associated with initial surgery in this patient population. PURPOSE: To identify variables that may be associated with surgical intervention in patients with shoulder instability in the context of the FEDS (frequency, etiology, direction, severity) classification, a system that may be useful in the surgical treatment of shoulder instability patients. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: A database of patients treated for shoulder instability from 3 separate institutions from 2005 to 2010 was generated using International Classification of Diseases-9th Revision data. Data were collected via retrospective review. Injury data were categorized according to the FEDS system. Data were analyzed for significance, with the primary outcome of surgical intervention. Summary statistics were used to assess which variables were associated with eventual surgery. To test the unadjusted bivariate associations between shoulder surgery and each data point, Pearson chi-square tests were used for categorical variables and Wilcoxon tests were used for continuous variables. RESULTS: Over the study time period, 377 patients were treated for shoulder instability. Patients who had surgery were more likely younger, had recurrent instability, and had their initial injury while playing a sport. Most patients had anterior instability; however, there was a greater proportion of posterior instability patients in the operative group. Severity of dislocation, measured by whether the patient required help to relocate the shoulder, was not significantly associated with eventual surgery. While imaging was not available for all patients, surgical patients were more likely to have magnetic resonance imaging findings of anterior labral injury and less likely to have a supraspinatus or subscapularis tear. CONCLUSION: Patients who underwent surgery for shoulder instability were younger, more likely to have experienced recurrent instability, and more likely to have sustained their original injury while playing sports. The FEDS classification, particularly the frequency and etiology of the patient's shoulder instability, may be helpful in identifying patients with a higher likelihood of undergoing surgical treatment.