Search

SH2‐containing inositol‐5′‐phosphatase‐1 (SHIP‐1) controls the phosphatidylinositol‐3′‐kinase (PI3K) initiated signaling pathway by limiting cell membrane recruitment and activation of Akt. Despite the fact that many of the growth factors important to cartilage development and functions are able to activate the PI3K signal transduction pathway, little is known about the role of PI3K signaling in chondrocyte biology and its contribution to mammalian skeletogenesis. Here, we report that the lipid phosphatase SHIP‐1 regulates chondrocyte hypertrophy and skeletal development through its expression in osteochondroprogenitor cells. Global SHIP‐1 knockout led to accelerated chondrocyte hypertrophy and premature formation of the secondary ossification center in the bones of postnatal mice. Drastically higher vascularization and greater number of c‐kit + progenitors associated with sinusoids in the bone marrow also indicated more advanced chondrocyte hypertrophic differentiation in SHIP‐1 knockout mice than in wild‐type mice. In corroboration with the in vivo phenotype, SHIP‐1 deficient PDGFRα + Sca‐1 + osteochondroprogenitor cells exhibited rapid differentiation into hypertrophic chondrocytes under chondrogenic culture conditions in vitro. Furthermore, SHIP‐1 deficiency inhibited hypoxia‐induced cellular activation of Akt and extracellular‐signal‐regulated kinase (Erk) and suppressed hypoxia‐induced cell proliferation. These results suggest that SHIP‐1 is required for hypoxia‐induced growth signaling under physiological hypoxia in the bone marrow. In conclusion, the lipid phosphatase SHIP‐1 regulates skeletal development by modulating chondrogenesis and the hypoxia response of the osteochondroprogenitors during endochondral bone formation. [ABSTRACT FROM AUTHOR]

Background. The incidence and risk factors of wound-healing complications following rotational ankle fracture surgery are well documented in the literature. However, there is a paucity regarding management options following these complications. The goal of this study was to provide a descriptive analysis of one surgeon's experience managing wound complications in patients who have undergone ankle fracture surgery. Methods. A total of 215 patients who were operatively treated for an unstable ankle were retrospectively identified. Patient demographics, medical histories, initial injury characteristics, surgical interventions, and clinical follow-up were collected. Twenty-five of these patients developed postoperative wound problems. Results. Of the original cohort of 215 patients, 25 (11.6%) developed wound-healing complications. Their average age was 53.6 ± 18.0 years; there were 12 males (48.0%). Connective tissue/inflammatory disease (odds ratio [OR] 3.9), cardiovascular disease (OR 3.6), and active smoking (OR 3.3) were associated with an increased likelihood of developing postoperative wound complications. With regard to injuries, open fractures (OR 17.9) had the highest likelihood of developing postoperative complications, followed by type 44-C (OR 2.8) and trimalleolar fractures (OR 2.0). Conclusion. Wound complications following open treatment of ankle fractures occurred with an incidence of 11.6% in this series, of which only about half required operative intervention. A third of wounds were managed by orthopaedics in conjunction with plastic surgery. Levels of Evidence: Level III: Retrospective comparative study. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to compare the long-term functional status of patients treated surgically for a clavicular nonunion using patients treated either op-eratively or non-operatively for an acute clavicle fracture as a comparison group., Methods: Twenty consecutive patients treated by a single surgeon for a clavicle fracture nonunion were identified. For comparison of outcomes, acute clavicle fractures were identified from an electronic medical record (EMR) query of the same orthopedic surgeon. Ninety acute clavicle fracture patients were identified and 27 (30%) patients were available for long-term follow-up. Clavicular nonunions were compared to acute clavicle fracture patients in a univariate analysis then a multivariate analysis to analyze clavicle nonunion patients against operative and non-operative acute clavicle fracture patients. The main outcome measures were time to bony union, postoperative complications, visual analog scale (VAS) pain scores, and Short Musculoskeletal Functional Assessment (SMFA) scores at long-term follow-up., Results: There was no difference in time to healing or functional outcomes as assessed by SMFA and VAS pain scores between clavicle nonunion and acute fracture patients. Postoperative complications also did not differ between the groups., Conclusions: Patients who are treated surgically for clavicular nonunions ultimately regain a similar functional status as patients who are treated either operatively or non-operatively for an acute clavicle fracture and heal acutely.