pulled closer to the chest,or a prone position accompanied by pressure over the bone,may help to dentify女 ndmarks by reducing the depth of the fat pad overlying the iliaccrest[38 .Examine the potential site for evidence of infection:palpate the posteno iliac crest and posterior superior iliac spine and locate these landmarks (fiaure 1)1391 The anterior superior iliac spine should also be palpated and located,as the needle will be pointed in this direction once the bone s been entered(fiqure 2) .Maintain a steady dialogue with the patient,explaining each step. alerting the patient to potential discomfort,with reassurance as needed. .In the absence of local skin problems(eg,infection,induration, ulceration).the usual site for aspiration and biopsy is approximately three s from the midline and two finger- widths int or to the iliac crest.Mark the chosen area by making an indentation in the skin with a coin,fingemail,or the end of a ballpoint pen with the writing tip retracted .Using sterile technique,protective clothing and gloves(and eye wear if necessary),the bone marrow tray should be first opened and organized for easy access to needed ito ems.Needi stylets, and plastic (not glass) syringes should be checked to ensure that they are intact and function propeny. .Cleanse the chosen area with povidone-iodine solution and drape a sterile field.Prepare the instruments. .Anesthetize the skin and subcutaneous tissues with a 1 to 2 percent lidocaine sol n using a 23-gauge needle:th en anesthetize the periosteum by repeatedly injecting small amounts of lidocaine solution at different points on the surface of the bone with a 21-gauge needle.It is useful to anesthetize a dime-sized area of the periosteum surrounding the tar nt adjacentsites .While waiting for the anesthetic to produce its effect,extra syringes for special studies(eg,flow cytometry,cytogenetics,and molecular studies) can be appropriately anticoagulated.Specimens for molecular studies should not contain heparin the help of an assistant is invaluable .Once local anesthesia has been achieved,make a small (3 mm)skin incision with a scalpel blade at the site of insertion of the aspiratior needle.in order to facilitate its entry and promote organized healing of the wound. .Hold the bone marrow needle (with stylet in place)perpendicular to the skin at the previously marked point,and gently advance it to the periosteur In order to be ure hat the edle is e ente ectly,the second and third fingers on the hand not being used to insert the needle should be placed on the iliac crest or spine and the needle inserted between them [3].When the needle has been advanced to the periosteum,it should be pointed laterally in the direction of the anteriorpulled closer to the chest, or a prone position accompanied by pressure over the bone, may help to identify the landmarks by reducing the depth of the fat pad overlying the iliac crest [38]. ●Examine the potential site for evidence of infection; palpate the posterior iliac crest and posterior superior iliac spine and locate these landmarks (figure 1) [39]. The anterior superior iliac spine should also be palpated and located, as the needle will be pointed in this direction once the bone has been entered (figure 2). ●Maintain a steady dialogue with the patient, explaining each step, alerting the patient to potential discomfort, with reassurance as needed. ●In the absence of local skin problems (eg, infection, induration, ulceration), the usual site for aspiration and biopsy is approximately three finger-widths from the midline and two finger-widths inferior to the iliac crest. Mark the chosen area by making an indentation in the skin with a coin, fingernail, or the end of a ballpoint pen with the writing tip retracted. ●Using sterile technique, protective clothing and gloves (and eye wear if necessary), the bone marrow tray should be first opened and organized for easy access to needed items. Needles, stylets, and plastic (not glass) syringes should be checked to ensure that they are intact and function properly. ●Cleanse the chosen area with povidone-iodine solution and drape a sterile field. Prepare the instruments. ●Anesthetize the skin and subcutaneous tissues with a 1 to 2 percent lidocaine solution using a 23-gauge needle; then anesthetize the periosteum by repeatedly injecting small amounts of lidocaine solution at different points on the surface of the bone with a 21-gauge needle. It is useful to anesthetize a dime-sized area of the periosteum surrounding the targeted location, as the aspiration and biopsy should be taken from slightly different adjacent sites. ●While waiting for the anesthetic to produce its effect, extra syringes for special studies (eg, flow cytometry, cytogenetics, and molecular studies) can be appropriately anticoagulated. Specimens for molecular studies should not contain heparin. The help of an assistant is invaluable. ●Once local anesthesia has been achieved, make a small (3 mm) skin incision with a scalpel blade at the site of insertion of the aspiration needle, in order to facilitate its entry and promote organized healing of the wound. ●Hold the bone marrow needle (with stylet in place) perpendicular to the skin at the previously marked point, and gently advance it to the periosteum. In order to be sure that the needle is entering correctly, the second and third fingers on the hand not being used to insert the needle should be placed on the iliac crest or spine and the needle inserted between them [3]. When the needle has been advanced to the periosteum, it should be pointed laterally in the direction of the anterior