Scapular winging is a rare, underreported, and debilitating disorder that produces abnormal scapulothoracic kinematics, which can lead to shoulder weakness, decreased range of motion, and substantial pain. Although there are numerous underlying etiologies, injuries to the long thoracic nerve or spinal accessory nerve are the most common, with resultant neuromuscular imbalance in the scapulothoracic stabilizing muscles. Early diagnosis followed by initiation of a treatment algorithm is important for successful outcomes. Most cases resolve with nonsurgical management. However, in patients with persistent symptoms despite nonsurgical management, appropriate dynamic muscle transfers can effectively treat the scapular winging, with good clinical outcomes.

Interstitial fibroblasts are an integral component of the alveolar wall. These cells produce matrix proteins that maintain the extracellular scaffold of alveolar structures. Emphysema is characterized by airspace enlargement resulting from the loss of alveolar cellularity and matrix. In this study, we explored the endotracheal delivery of fibroblasts to the lung parenchyma as a means of repairing damaged alveolar structures directly or indirectly for the delivery of transgenes. Fibroblasts were isolated from the lungs of neonatal transgenic mice expressing GFP during the period of rapid alveolarization. These GFP ϩ cells maintained their myofibroblast phenotype in culture and expressed elastin and ␣-smooth muscle actin mRNA. We administered GFP ϩ fibroblasts to saline-and elastase-treated mice by endotracheal instillation. We detected more GFP ϩ fibroblasts in the alveolar walls and in the interstitial areas of elastaseinjured lungs than in normal lungs as assessed by immunohistochemistry and fluorescent imaging. The presence of GFP ϩ fibroblasts in the interstitium demonstrated transepithelial migration of these cells. Expression of GFP ϩ fibroblasts in recipient lungs was maintained for at least 20 d after endotracheal administration. These cells synthesize matrix components including elastin in vitro and could contribute to restoring the structural integrity of the alveolar wall.Keywords: elastase; elastin; emphysema; fibroblasts Emphysema is defined by the presence of airspace enlargement (1, 2). The occurrence of emphysema in patients with ␣ 1 -antitrypsin inhibitor deficiency indicates that destruction of matrix substances especially elastin and collagen is an important feature of this process. Failure to repair damaged elastin may also contribute to airspace enlargement. Mice deficient in lysyl oxidaselike protein 1 (LOXL1) develop airspace enlargement in adult life (3). This enzyme promotes the formation of crosslinks between elastin fibrils in the developing fiber and is a component of the extracellular scaffold providing structural support to alveolar walls. The elastin and collagen network is subject to remodeling, presumably by synthesis and incorporation of newly formed fibrils into damaged fibers. The failure to maintain elastin renewal in the alveolar wall results in loss of structural integrity. Similarly, mice deficient in fibulin-5 develop airspace enlargement. This extracellular protein binds elastin and LOXL1 and may be important in the organization of the extracellular scaffold (4).Emphysema in mice can be induced by endotracheal administration of pancreatic or neutrophil elastase (2). Levels of lung (Received in original form October 8, 2004 and in final form May 15, 2005) This work was supported by the Department of Veterans Affairs REAP research program and the National Heart, Lung, and Blood Institute Grants HL66547 and HL46902.Correspondence and requests for reprints should be addressed to Ronald H. Goldstein, M.D., The Pulmonary Center, Boston University School of Medicine, 715 Alba...

The HFIA material looks promising as a potential solution to stripped screws in osteoporotic bone. However, this material has yet to be tested in human bone. Furthermore, the fine mesh material could be damaged by autoclaving and could break off in vivo causing unknown tissue reactions. We recommend additional testing in a living animal model to better understand how living bone will react to the HFIA material.

Background: Previous studies have aimed to biomechanically improve the transosseous tunnel technique of rotator cuff repair. However, no previous work has addressed tunnel inclination at the time of surgery as an influence on the strength of the repair construct. Hypothesis: We hypothesized that the tunnel angle and entry point would influence the biomechanical strength of the transosseous tunnel in rotator cuff repair. Additionally, we investigated how tunnel length and bone quality affect the strength of the repair construct. Study Design: Controlled laboratory study. Methods: Mechanical testing was performed on 10 cadaveric humeri. Variations in the bone tunnel angle were imposed in the supraspinatus footprint to create lateral tunnels with inclinations of 30°, 45°, and 90° relative to the longitudinal axis of the humeral shaft. A closed loop of suture was passed through the bone tunnel, and cyclic loading was applied until failure of the construct. Load to failure and distance between entry points were the dependent variables. Analysis of variance, post hoc paired t tests, and the Bonferroni correction were used to analyze the relationship between the tunnel angle and failure load. The Pearson correlation coefficient was then used to evaluate the correlation of the distance between entry points to the ultimate failure load, and t tests were used to compare failure loads between healthy and osteoporotic bone. Results: Tunnels drilled perpendicularly to the longitudinal axis (90°) achieved the highest mean failure load (167.51 ± 48.35 N). However, there were no significant differences in the failure load among the 3 tested inclinations. Tunnels drilled perpendicularly to the longitudinal axis (90°) measured 13.86 ± 1.35 mm between entry points and were significantly longer ( P = .03) than the tunnels drilled at 30° and 45°. We found no correlation of the distance between entry points and the ultimate failure load. Within the scope of this study, we could not identify a significant effect of bone quality on failure load. Conclusion: The tunnel angle does not influence the strength of the bone-suture interface in the transosseous rotator cuff repair construct. Clinical Relevance: The transosseous technique has gained popularity in recent years, given its arthroscopic use. These findings suggest that surgeons should not focus on the tunnel angle as they seek to maximize repair strength.