High frequency of posterior and combined shoulder instability in young active patients.

OBJECTIVE: The purpose of this study was to describe the epidemiology and demographics of surgically treated shoulder instability stratified by direction. We hypothesized that there would be an increased frequency of posterior and combined shoulder instability in our population compared with published literature. Secondarily, we assessed preoperative magnetic resonance imaging (MRI) reports to determine how accurately they detected the pathology addressed at surgery. MATERIALS AND METHODS: A retrospective review was conducted at a single facility during a 46-month period. The study included all patients who underwent an operative intervention for shoulder instability. The instability in each case was characterized as isolated anterior, isolated posterior, or combined, according to pathologic findings confirmed at arthroscopy. The findings were retrospectively compared with official MRI reports to determine the accuracy of MRI in characterizing the clinically and operatively confirmed diagnosis. RESULTS: A consecutive series of 231 patients (221 men, 10 women) underwent stabilization for shoulder instability over 46 months. Patients were a mean age of 26.0 years. There were 132 patients (57.1%) with isolated anterior instability, 56 (24.2%) with isolated posterior instability, and 43 (18.6%) with combined instability. Overall, MRI findings completely characterized the clinical diagnosis and arthroscopic pathology in 149 of 219 patients (68.0%). CONCLUSION: The rate of posterior and combined instability in an active population is more common than has been previously reported, making up more than 40% of operatively treated instability, including a previously unreported incidence of 19% for combined instabilities. In addition, MRI was often incomplete or inaccurate in detecting the pathology eventually treated at surgery.

Improving visualization in shoulder arthroscopy.

Arthroscopic shoulder procedures are one of the most common procedures used to restore function through minimally invasive techniques. With the demand for shoulder arthroscopic procedures comes the need for safe, effective, and efficient surgery that maximizes patient outcomes while minimizing complications. Many variables contribute to visualization in shoulder arthroscopy including vascular anatomy, blood pressure control, arthroscopic pump systems, turbulence control, epinephrine, and tranexamic acid. Furthermore, patient positioning can have a dramatic effect on visualization with both the beach chair position and lateral decubitus positioning having various strengths and weaknesses depending on the intended procedure being performed. The purpose of this review is to examine the benefits and complications reported in the literature for improving visualization in shoulder arthroscopy.

Minimally Invasive Distal Biceps Tendon Reconstruction With Semitendinosus Allograft and Dual Unicortical Button Fixation.

Complete rupture of the distal biceps tendon is routinely treated with direct repair; however, chronic, mid-substance, or musculotendinous tears are challenging clinical scenarios for surgeons. Although attempts at direct repair should be considered, in cases of severe retraction or tendon deficiency, a reconstruction may be warranted. Herein the authors describe a technique for distal biceps reconstruction using allograft with a Pulvertaft weave via a standard anterior incision, similar to primary repair, with a small catchment incision more proximally for tendon retrieval. Use of this technique with dual unicortical buttons allows for early range of motion, restoration of the distal footprint, and improved biomechanical construct strength, which has proven invaluable in a population of elite and highly active military servicemembers.

Post-operative Baseplate Radiographic Evaluation Using Routine pre-Operative CT.

Background: There is limited data evaluating post-operative component position and fixation in reverse shoulder arthroplasty (RSA). Therefore, the purpose of this study was to evaluate baseplate position and fixation using routine pre-operative CT and post-operative radiographs. Methods: A retrospective analysis of a series consecutive patient who underwent primary RSA was performed. Pre-operative and post-operative glenoid retroversion and inclination were measured using radiographs aligned with projection silhouettes of 3D scapula models in Mimics software. Baseplate retroversion and inclination were measured followed by evaluating for the presence of radiolucent lines (RLLs). Results: Twenty-four patients met inclusion criteria. The average age was 73.4 ± 10.7 years (range, 45-89 years). Radiographic follow-up was 3.4 ± 1.3 years. Post-operative glenoid baseplate retroversion was 2 ± 10 degrees (range, 30 to -9). Post-operative glenoid baseplate inclination was 3.8 ± 9.1 (range, -13 to 19). Five (21%) RSAs had baseplate retroversion >10 degrees. Follow-up radiographs revealed no RLLs around the baseplate, central post, or peripheral screws in any patient. Conclusions: Pre-operative CT imaging enabled evaluation of baseplate component placement and fixation on post-operative radiographs. Baseplate version was within 10 degrees of neutral in 79% (19/24) of patients. No RLLs or loss of fixation were found in any cases. Level of Evidence: Level IV: Diagnostic Study.

Local Accumulation of Axonal Mitochondria in the Optic Nerve Glial Lamina Precedes Myelination.

Mitochondria are essential for neurons and must be optimally distributed along their axon to fulfill local functions. A high density of mitochondria has been observed in retinal ganglion cell (RGC) axons of an unmyelinated region of the optic nerve, called the glial lamina (GL) in mouse (lamina cribrosa in human). In glaucoma, the world's leading cause of irreversible blindness, the GL is the epicenter of RGC degeneration and is connected to mitochondrial dysfunction. It is generally accepted that the local accumulation of mitochondria in the GL is established due to the higher energy requirement of unmyelinated axons. Here we revisit the connection between mitochondrial positioning and myelin in RGC axons. We show that the high density of mitochondria in the GL is restricted to larger axons and is established before myelination. Thus, contrary to a longstanding belief in the field, the myelination pattern is not responsible for the establishment of the local accumulation of mitochondria in GL axons. Our findings open new research avenues likely critical to understanding the pathophysiology of glaucoma.

Return to Duty After Mini-Open Arthroscopic-Assisted Treatment of Femoroacetabular Impingement in an Active Military Population.

PURPOSE: To report the return-to-duty rate and surgical outcomes in a military population after mini-open arthroscopic-assisted surgery for femoroacetabular impingement (FAI) in an effort to affirm its efficacy. METHODS: A retrospective review of consecutive active-duty patients receiving mini-open arthroscopic-assisted surgery for FAI between 2007 and 2011 was performed. Patients younger than 18 years, non-active-duty patients, and patients with prior hip surgery were excluded. Demographic, radiographic, and duty-status data were collected. The primary outcome measure was a return to duty. Outcome scores were obtained in a proportion of the cohort, including the modified Harris Hip Score, Single Assessment Numeric Evaluation score, Western Ontario and McMaster Universities Osteoarthritis Index score, patient satisfaction score, and Veterans RAND 12 (VR-12) score. All patients had achieved a minimum of 1 year of follow-up at the time of assessment. All P values for significance were set at .05 or lower. RESULTS: Of 182 patients (average age, 30.4 years), 156 (86%) were available for follow-up with return-to-duty data at an average of 2.8 years (range, 1-6 years). Of the patients, 78% returned to full duty (53%) or returned to duty with restrictions (25%). Outcome scores were available for 101 of 182 patients (55%) with duty rates similar to the total cohort (81% who returned to duty: 58% with no restrictions and 23% with restrictions). Return to duty correlated with improved outcomes compared with those who were medically discharged with respect to the modified Harris Hip Score (68.2 vs 54.5, P < .03), Single Assessment Numeric Evaluation score (48.2 vs 25.3, P < .02), and VR-12 physical (39.7 vs 33.2, P < .05) and VR-12 mental (54.5 vs 43.4, P < .005) scores. CONCLUSIONS: Mini-open arthroscopic-assisted surgery for FAI is successful in returning most service members to duty at short-term follow-up. Return correlates with improved outcome scores, although previously reported minimally clinical important difference and patient acceptable symptomatic state threshold values were not uniformly achieved. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Distal Knee Medial Collateral Ligament Repair With Suture Augmentation.

The medial collateral ligament (MCL) is the most commonly injured ligament of the knee. Given its extra-articular location, the MCL has great healing capacity such that the mainstay of treatment for most injuries remains conservative management. However, certain injury patterns place patients and athletes at risk of residual valgus laxity, which may require delayed surgical care and prolonged time out from sports. As such, identifying the specific injuries known to place patients at risk for failure with nonoperative management is of paramount importance. Although controversy remains regarding the optimal treatment of grade III MCL injuries, it is generally accepted that MCL ruptures from the distal tibia attachment require operative fixation. This technique article with accompanying video provides a detailed description of a technique for repairing the distal MCL attachment with suture augmentation. There are several advantages associated with an augmented direct repair including early, safe rehabilitation; prevention of valgus instability; and avoiding the comorbidities associated with a larger reconstruction.

Regulation of multiple tumor microenvironment markers by overexpression of single or paired combinations of ErbB receptors.

The progression of primary tumors to an invasive phenotype requires dynamic changes in multiple cellular and local tumor microenvironment markers. In this study, we report a genomic approach to assess gene transcriptional changes upon overexpression of ErbB receptors, in vitro and in vivo, focusing on markers involved in the regulation of the tumor microenvironment. ErbB receptors (ErbB-1/epidermal growth factor receptor, ErbB-2, ErbB-3, and ErbB-4) were stably overexpressed in a polyclonal cell population as single or paired combinations using murine and human breast cell models. The overall numbers of known genes that are up- or down-regulated was significantly higher in cells and tumors overexpressing paired combinations of receptors compared with cells and tumors overexpressing single ErbB receptors. Genes encoding components of cell-cell structures, extracellular matrix, coagulation factors, and angiogenesis were predominantly affected by the most active ErbB receptor combinations and were predictive of the aggressive in vivo tumorigenicity, a feature that was not always seen in vitro. Among ErbB-regulated tumor microenvironment markers detected by the genomic analysis, thrombospondin 1, an endogenous inhibitor of angiogenesis, was additionally validated in relation to tumor growth phenotype. Thrombospondin 1 mRNA and protein were down-regulated by specific ErbB receptors, in vitro and in both rodent and human ErbB-induced tumors, consistent with the extent of tumor growth and tumor vascularization associated with specific ErbB receptors. In summary, our genomic results highlight the broad diversity of ErbB-regulated cancer-associated genes and revealed several novel targets that may have potential therapeutic applications for targeting tumor progression involving aberrations of ErbB receptors.

Redefining "Critical" Bone Loss in Shoulder Instability: Functional Outcomes Worsen With "Subcritical" Bone Loss.

BACKGROUND: Glenoid bone loss is a common finding in association with anterior shoulder instability. This loss has been identified as a predictor of failure after operative stabilization procedures. Historically, 20% to 25% has been accepted as the "critical" cutoff where glenoid bone loss should be addressed in a primary procedure. Few data are available, however, on lesser, "subcritical" amounts of bone loss (below the 20%-25% range) on functional outcomes and failure rates after primary arthroscopic stabilization for shoulder instability. PURPOSE: To evaluate the effect of glenoid bone loss, especially in subcritical bone loss (below the 20%-25% range), on outcomes assessments and redislocation rates after an isolated arthroscopic Bankart repair for anterior shoulder instability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Subjects were 72 consecutive anterior instability patients (73 shoulders) who underwent isolated anterior arthroscopic labral repair at a single military institution by 1 of 3 sports medicine fellowship-trained orthopaedic surgeons. Data were collected on demographics, the Western Ontario Shoulder Instability (WOSI) score, Single Assessment Numeric Evaluation (SANE) score, and failure rates. Failure was defined as recurrent dislocation. Glenoid bone loss was calculated via a standardized technique on preoperative imaging. The average bone loss across the group was calculated, and patients were divided into quartiles based on the percentage of glenoid bone loss. Outcomes were analyzed for the entire cohort, between the quartiles, and within each quartile. Outcomes were then further stratified between those sustaining a recurrence versus those who remained stable. RESULTS: The mean age at surgery was 26.3 years (range, 20-42 years), and the mean follow-up was 48.3 months (range, 23-58 months). The cohort was divided into quartiles based on bone loss. Quartile 1 (n = 18) had a mean bone loss of 2.8% (range, 0%-7.1%), quartile 2 (n = 19) had 10.4% (range, 7.3%-13.5%), quartile 3 (n = 18) had 16.1% (range, 13.5%-19.8%), and quartile 4 (n = 18) had 24.5% (range, 20.0%-35.5%). The overall mean WOSI score was 756.8 (range, 0-2097). The mean WOSI score correlated with SANE scores and worsened as bone loss increased in each quartile. There were significant differences (P < .05) between quartile 1 (mean WOSI/SANE, 383.3/62.1) and quartile 2 (mean, 594.0/65.2), between quartile 2 and quartile 3 (mean, 839.5/52.0), and between quartile 3 and quartile 4 (mean, 1187.6/46.1). Additionally, between quartiles 2 and 3 (bone loss, 13.5%), the WOSI score increased to rates consistent with a poor clinical outcome. There was an overall failure rate of 12.3%. The percentage of glenoid bone loss was significantly higher among those repairs that failed versus those that remained stable (24.7% vs 12.8%, P < .01). There was no significant difference in failure rate between quartiles 1, 2, and 3, but there was a significant increase in failure (P < .05) between quartiles 1, 2, and 3 (7.3%) when compared with quartile 4 (27.8%). Notably, even when only those patients who did not sustain a recurrent dislocation were compared, bone loss was predictive of outcome as assessed by the WOSI score, with each quartile's increasing bone loss predictive of a worse functional outcome. CONCLUSION: While critical bone loss has yet to be defined for arthroscopic Bankart reconstruction, our data indicate that "critical" bone loss should be lower than the 20% to 25% threshold often cited. In our population with a high level of mandatory activity, bone loss above 13.5% led to a clinically significant decrease in WOSI scores consistent with an unacceptable outcome, even in patients who did not sustain a recurrence of their instability.

The Effect of Syndesmosis Screw Removal on the Reduction of the Distal Tibiofibular Joint: A Prospective Radiographic Study.

BACKGROUND: Injury to the tibiofibular syndesmosis is frequent with rotational ankle injuries. Multiple studies have shown a high rate of syndesmotic malreduction with the placement of syndesmotic screws. There are no studies evaluating the reduction or malreduction of the syndesmosis after syndesmotic screw removal. The purpose of this study was to prospectively evaluate syndesmotic reduction with CT scans and to determine the effect of screw removal on the malreduced syndesmosis. METHODS: This was an IRB-approved prospective radiographic study. Patients over 18 years of age treated at 1 institution between August 2008 and December 2011 with intraoperative evidence of syndesmotic disruption were enrolled. Postoperative CT scans were obtained of bilateral ankles within 2 weeks of operative fixation. Syndesmotic screws were removed after 3 months, and a second CT scan was then obtained 30 days after screw removal. Using axial CT images, syndesmotic reduction was evaluated compared to the contralateral uninjured ankle. Twenty-five patients were enrolled in this prospective study. The average age was 25.7 (range, 19 to 35), with 3 females and 22 males. RESULTS: Nine patients (36%) had evidence of tibiofibular syndesmosis malreduction on their initial postoperative axial CT scans. In the postsyndesmosis screw removal CT scan, 8 of 9 or 89% of malreductions showed adequate reduction of the tibiofibular syndesmosis. There was a statistically significant reduction in syndesmotic malreductions ( t = 3.333, P < .001) between the initial rate of malreduction after screw placement of 36% (9/25) and the rate of malreduction after all screws were removed of 4% (1/25). CONCLUSIONS: Despite a high rate of initial malreduction (36%) after syndesmosis screw placement, 89% of the malreduced syndesmoses spontaneously reduced after screw removal. Syndesmotic screw removal may be advantageous to achieve final anatomic reduction of the distal tibiofibular joint, and we recommend it for the malreduced syndesmosis. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Isolated ring finger flexor digitorum profundus entrapment after closed reduction and intramedullary fixation of both-bone forearm fracture.

Flexor tendon entrapment after a pediatric forearm fracture is a rarely reported complication that is often diagnosed late. Flexor tendon entrapment is more frequently reported after distal forearm fractures, and possible etiologies include fibrosis secondary to hemorrhage at the fracture site and simple entrapment of the muscle belly.This article describes a case of ring finger flexor digitorum profundus entrapment in a 12-year-old boy with a closed both-bone forearm fracture that was treated with closed reduction and intramedullary nail fixation. Preoperatively, the patient had full flexion and extension of all fingers. The entrapment was noted at the first postoperative follow-up when the patient could fully extend the ring finger proximal interphalangeal joint but was unable to concomitantly extend the metacarpal phalangeal joint. Magnetic resonance imaging and ultrasound were obtained to identify the entrapment site. Intraoperatively, a portion of the flexor digitorum profundus musculotendinous junction was entrapped in the fracture site. After release of the entrapment, the patient gained immediate passive range of motion. Subsequently, the hardware was removed, and the patient healed and regained full ring finger function. To the authors' knowledge, this is the only report of isolated ring finger flexor digitorum profundus entrapment after closed reduction and intramedullary fixation of a pediatric forearm fracture. The authors recommend vigilant physical examination of passive and active range of motion of all digital joints with the wrist in flexion and extension before and after bony manipulation.

Anterior ulnohumeral compression plate arthrodesis for revision complex elbow injury: a case report.

Elbow arthrodesis can be used for complex elbow injuries that are complicated or fail other conventional treatment methods. We present a case report of an anterior ulnohumeral compressive plate elbow arthrodesis for a patient with a complex elbow injury from a gunshot wound that failed initial open reduction and internal fixation and posterior ulnohumeral arthrodesis secondary to numerous complications.