Acne Scars

J Appl Physiol. 2009 Jun 18; Eliasson P, Andersson T, Aspenberg PInjured tendons require mechanical tension for optimal healing, but it is unclear which genes are upregulated and responsible for this response. We unloaded one Achilles tendon in rats by Botox injections in the calf muscles. The tendon was then transected and left to heal. We studied mechanical properties of the tendon callus, as well as mRNA expression, and compared them too loaded controls. Tendon calluses were studied 3, 8, 14 and 21 days after transection. Intact tendons were studied similarly for comparison. Altogether 110 rats were used. The genes were chosen for proteins marking inflammation, growth, extracellular matrix and tendon specificity. In intact tendons, procollagen III and tenascin-C were more expressed in loaded than unloaded tendons, but none of the other genes was affected. In healing tendons, loading status had small effects on the selected genes. However, TNF, TGF-b1 and procollagens I and III were less expressed in loaded callus tissue day 3. At day 8, also procollagens I and III, LOX and scleraxis had a lower expression in loaded calluses. However, by day 14 and 21, procollagen I, COMP, tenascin-C, tenomodulin and scleraxis were all more expressed in loaded calluses. In healing tendons, the transverse area was larger in loaded samples, but material properties were unaffected, or even impaired. Thus, mechanical loading is important for growth of the callus, but not its mechanical quality. The main effect of loading during healing might thereby be sought among growth stimulators. In the late phase of healing, tendon-specific genes (scleraxis and tenomodulin) were upregulated with loading, and the healing tissue might to some extent represent a regenerate rather than a scar. Key words: Unloading, tendon healing, inflammation, extracellular matrix, mechanobiology.

Spine J. 2009 Jun 17; Kim DH, Rhim R, Li L, Martha J, Swaim B, Banco RJ, Jenis LG, Tromanhauser SGBACKGROUND CONTEXT: Morbidity associated with autologous bone graft harvest is an important factor in determining the utility of expensive alternatives such as recombinant bone morphogenic protein. The most frequently reported complication associated with graft harvest is chronic pain. PURPOSE: To prospectively determine the degree of pain and morbidity associated with autologous iliac crest bone graft harvest and its effect on activities of daily living. STUDY DESIGN: Prospective observational cohort study. PATIENT SAMPLE: One hundred ten adult patients undergoing elective posterior lumbar spinal fusion surgery involving autologous iliac crest bone graft harvest. OUTCOME MEASURES: Patient self-reported Visual Analog Scale (VAS) scores for pain and a study-specific questionnaire regarding activities of daily living. METHODS: One hundred ten patients were prospectively enrolled. Postoperative VAS scores (0-100) for harvest site pain were obtained at 6-week, 6- and 12-month follow-up. Patients completed a 12-month questionnaire regarding the persistence of specific symptoms and resulting limitation of specific activities. RESULTS: One hundred four patients were available for 1-year follow-up. Mean VAS pain scores (scale 0-100) at 6 weeks, 6 and 12 months were 22.7 (standard deviation [SD], 25.9), 15.9 (SD, 21.5), and 16.1 (SD, 24.6), respectively. At 12 months, 16.5% reported more severe pain from the harvest site than the primary surgical site, 29.1% reported numbness, and 11.3% found the degree of numbness bothersome, whereas 3.9% were bothered by scar appearance. With respect to activity limitations resulting from harvest site pain at 1 year, 15.1% reported some difficulty walking, 5.2% with employment, 12.9% with recreation, 14.1% with household chores, 7.6% with sexual activity, and 5.9% irritation from clothing. CONCLUSIONS: There is a significant rate of persistent pain and morbidity from iliac crest bone graft harvest when associated with elective spine surgery. Mean pain scores progressively decline over the first postoperative year. Nevertheless, harvest site pain remains functionally limiting in a significant percentage of patients 1 year after surgery. Rates of functional limitation are higher than previously reported and may be because of increased sensitivity of the prospective study design and targeted investigation of these specific symptoms. Validity of these findings is necessarily limited by patient ability to discriminate harvest site pain from alternative sources of back and buttock pain.