Sarah M. Yannascoli

Does timing to operative debridement affect infectious complications in open long-bone fractures? A systematic review

BACKGROUND Existing guidelines recommend emergency surgical debridement of open fractures within six hours after injury. The aim of this study was to systematically review the association between time to operative debridement of open fractures and infection. METHODS Searches of the MEDLINE, EMBASE, and Cochrane computerized literature databases and manual searches of bibliographies were performed. Randomized controlled trials and cohort studies (retrospective and prospective) evaluating the association between time to operative debridement and infection after open fractures were included. Descriptive and quantitative data were extracted. A meta-analysis of patient cohorts who underwent early or delayed debridement was performed with use of a random effects model. RESULTS The initial search identified 885 references. Of the 173 articles inspected further on the basis of the title, sixteen (six prospective and ten retrospective cohort studies with a total of 3539 open fractures) were included. No significant difference in the infection rate was detected between open fractures debrided early or late according to any of the time thresholds used in the included studies. Sensitivity analyses demonstrated no difference in infection rate between early and late debridement in subgroups defined according to the Gustilo-Anderson classification, level of evidence, depth of infection, or anatomic location. CONCLUSIONS The data did not indicate an association between delayed debridement and higher infection rates when all infections were considered, when only deep infections were considered, or when only more severe open fracture injuries were considered. On the basis of this analysis, the historical “six-hour rule” has little support in the available literature. It is important to realize that additional carefully conducted studies are needed and that elective delay of treatment of patients with open fractures is not recommended

Structure-function relationships of postnatal tendon development: a parallel to healing.

This review highlights recent research on structure-function relationships in tendon and comments on the parallels between development and healing. The processes of tendon development and collagen fibrillogenesis are reviewed, but due to the abundance of information in this field, this work focuses primarily on characterizing the mechanical behavior of mature and developing tendon, and how the latter parallels healing tendon. The role that extracellular matrix components, mainly collagen, proteoglycans, and collagen cross-links, play in determining the mechanical behavior of tendon will be examined in this review. Specifically, collagen fiber re-alignment and collagen fibril uncrimping relate mechanical behavior to structural alterations during development and during healing. Finally, attention is paid to a number of recent efforts to augment injured tendon and how future efforts could focus on recreating the important structure-function relationships reviewed here.

The Detrimental Effects of Systemic Ibuprofen Delivery on Tendon Healing Are Time-Dependent

BackgroundCurrent clinical treatment after tendon repairs often includes prescribing NSAIDs to limit pain and inflammation. The negative influence of NSAIDs on bone repair is well documented, but their effects on tendon healing are less clear. While NSAIDs may be detrimental to early tendon healing, some evidence suggests that they may improve healing if administered later in the repair process.Questions/purposesWe asked whether the biomechanical and histologic effects of systemic ibuprofen administration on tendon healing are influenced by either immediate or delayed drug administration.MethodsAfter bilateral supraspinatus detachment and repair surgeries, rats were divided into groups and given ibuprofen orally for either Days 0 to 7 (early) or Days 8 to 14 (delayed) after surgery; a control group did not receive ibuprofen. Healing was evaluated at 1, 2, and 4 weeks postsurgery through biomechanical testing and histologic assessment.ResultsBiomechanical evaluation resulted in decreased stiffness and modulus at 4 weeks postsurgery for early ibuprofen delivery (mean ± SD [95% CI]: 10.8 ± 6.4 N/mm [6.7–14.8] and 8.9 ± 5.9 MPa [5.4–12.3]) when compared to control repair (20.4 ± 8.6 N/mm [16.3–24.5] and 15.7 ± 7.5 MPa [12.3–19.2]) (p = 0.003 and 0.013); however, there were no differences between the delayed ibuprofen group (18.1 ± 7.4 N/mm [14.2–22.1] and 11.5 ± 5.6 MPa [8.2–14.9]) and the control group. Histology confirmed mechanical results with reduced fiber reorganization over time in the early ibuprofen group.ConclusionsEarly administration of ibuprofen in the postoperative period was detrimental to tendon healing, while delayed administration did not affect tendon healing.Clinical RelevanceHistorically, clinicians have often prescribed ibuprofen after tendon repair, but this study suggests that the timing of ibuprofen administration is critical to adequate tendon healing. This research necessitates future clinical studies investigating the use of ibuprofen for pain control after rotator cuff repair and other tendon injuries.

Scapular Dyskinesis is Detrimental to Shoulder Tendon Properties and Joint Mechanics in a Rat Model

Shoulder tendon injuries are frequently seen in the presence of abnormal scapular motion, termed scapular dyskinesis. The cause and effect relationship between scapular dyskinesis and shoulder injury has not been directly defined. We developed and used an animal model to examine the initiation and progression of pathological changes in the rotator cuff and biceps tendon. Sixty male Sprague–Dawley rats were randomized into two groups: nerve transection (to induce scapular dyskinesis, SD) or sham nerve transection (control). The animals were euthanized 4 and 8 weeks after surgery. Shoulder function and passive joint mechanics were evaluated over time. Tendon mechanical, histological, organizational, and compositional properties were evaluated at both time points. Gross observation demonstrated alterations in scapular motion, consistent with scapular “winging.” Shoulder function, passive internal range of motion, and tendon mechanical properties were significantly altered. Histology results, consistent with tendon pathology (rounded cell shape and increased cell density), were observed, and protein expression of collagen III and decorin was altered. This study presents a new model of scapular dyskinesis that can rigorously evaluate cause and effect relationships in a controlled manner. Our results identify scapular dyskinesis as a causative mechanical mechanism for shoulder tendon pathology.

Management of Soft Tissue Defects of the Hand

Soft tissue coverage of the hand remains a challenging problem to the hand surgeon, but advances in the field of microsurgery have provided improved thin, pliable, durable flaps that offer cosmetic reconstructive options. The reconstructive elevator is poised to replace the reconstructive ladder, thereby allowing early reconstruction by the best available option. This reviews focus on the variety of pedicled, free fasciocutaneous, and venous flaps available for successful soft tissue coverage of the hand.

Effect of isolated hyperglycemia on native mechanical and biologic shoulder joint properties in a rat model

Recently, diabetes has been linked to rotator cuff disease and adhesive capsulitis, conditions with increased stiffness and inflammation. Unfortunately, limited research exists examining how hyperglycemia affects the native shoulder (tendon and capsule) properties. Therefore, the objectives of this study were to compare shoulder joint mechanics, tendon properties (mechanics and immunohistochemistry), and capsule of healthy control and hyperglycemic rats 8 weeks following induction of hyperglycemia with a submaximal dose of streptozotocin (STZ). Eighteen rats were injected with STZ to induce hyperglycemia or citrate buffer (control) and underwent normal cage activity for 8 weeks. Passive joint mechanics demonstrated significantly less external rotation in the hyperglycemic group compared to controls, with no other group differences. Tendon mechanical properties (stiffness and modulus) were not significantly different between groups at both the insertion site and mid‐substance. Immunohistochemistry staining of the tendon and capsule demonstrated significantly increased interleukin 1‐beta (IL1‐β) and advanced glycated end‐products (AGE) staining localized to the insertion and mid‐substance of the tendon but not the capsule. In addition, tumor necrosis factor alpha (TNF‐α) staining was significantly increased in the superior capsule but not the supraspinatus tendon. This study demonstrates that isolated hypergylcemia does not diminish shoulder mechanical properties but does induce a chronic inflammatory response.

Effect of scapular dyskinesis on supraspinatus repair healing in a rat model

BACKGROUND Rotator cuff tears are common conditions that often require surgical repair to improve function and to relieve pain. Unfortunately, repair failure remains a common problem after rotator cuff repair surgery. Several factors may contribute to repair failure, including age, tear size, and time from injury. However, the mechanical mechanisms resulting in repair failure are not well understood, making clinical management difficult. Specifically, altered scapular motion (termed scapular dyskinesis) may be one important and modifiable factor contributing to the risk of repair failure. Therefore, the objective of this study was to determine the effect of scapular dyskinesis on supraspinatus tendon healing after repair. METHODS A rat model of scapular dyskinesis was used. Seventy adult male Sprague-Dawley rats (400-450 g) were randomized into 2 groups: nerve transection of the accessory and long thoracic nerves (SD) or sham nerve transection (Sham control). After this procedure, all rats underwent unilateral detachment and repair of the supraspinatus tendon. All rats were sacrificed at 2, 4, and 8 weeks after surgery. Shoulder function, passive joint mechanics, and tendon properties (mechanical, histologic, organizational, and compositional) were evaluated. RESULTS Scapular dyskinesis alters joint function and may lead to compromised supraspinatus tendon properties. Specifically, diminished mechanical properties, altered histology, and decreased tendon organization were observed for some parameters. CONCLUSION This study identifies scapular dyskinesis as one underlying mechanism leading to compromise of supraspinatus healing after repair. Identifying modifiable factors that lead to compromised tendon healing will help improve clinical outcomes after repair.

Erratum to: Biceps Detachment Decreases Joint Damage in a Rotator Cuff Tear Rat Model

The online version of the original article can be found under doi:10.1007/s11999-013-3422-8.