A quantitative anatomic study of plate-screw fixation of the acetabular anterior column through an anterior approach.

BACKGROUND: Screw penetration of the hip joint is a serious complication during plate-screw internal fixation of acetabular anterior column or anterior wall fractures through an anterior approach. The purpose of the cadaveric study is to determine safe paths for screw placement on the anterior column of the acetabulum. METHODS: A total of 46 hemipelvises (24 male, 22 female) were utilized in this study. These hemipelvises were sectioned, and formed cross-sections anterior endpoint (AEP), anterior quarter point (AQP), midpoint (MP), posterior quarter point (PQP) and posterior endpoint (PEP), respectively. Positions at distances of 0.5-, 1.0-, and 1.5-cm lateral to the pelvic brim on cross-section AQP, MP and PQP were marked, respectively. The nearest distance from entry points of the anterior column to the hip joint, the average medial angulation of cortical screws at 0.5-, 1.0-, and 1.5-cm entry points on cross-section AQP, MP and PQP were measured. RESULTS: The nearest distance from 0.5-, 1.0-, and 1.5-cm entry points to the hip joint is 15.6 +/- 1.5, 13.1 +/- 1.2, and 11.2 +/- 1.4 mm, respectively. The maximum medial angulation to provide safe cortical screw placement at 0.5-, 1.0-, and 1.5-cm entry points is 8.2 +/- 2.2 degrees, 14.9 +/- 3.4 degrees, and 26.1 +/- 4.5 degrees, respectively. CONCLUSIONS: During the operation of plate-screw fixation of the anterior column on the acetabulum, there are three ways to avoid screw penetration of the hip joint. The first one is to use the long screw. Its entry point is placed as close to pelvic brim as possible, and the entry direction is parallel to the quadrilateral surface. The second one is to use the short screws whose lengths are 14, 12 and 10 mm and locate them in the region between the pelvis brim and 0.5-cm entry point, between 0.5- and 1.0-cm entry point, between 1.0- and 1.5-cm entry point, respectively, regardless of the direction of the screw placement. The third one is to take quadrilateral surface as a reference plane, and adjust the medial angulation of the screw placement according to different target locations, i.e., in the coronal plane ranges from 0 degrees to 10 degrees in the region between pelvis brim and 0.5-cm entry point, 10 degrees-20 degrees in the region between 0.5- and 1.0-cm entry point, and 20 degrees-30 degrees in the region between 1.0- and 1.5-cm entry point.

Clinical anatomic study of internal fixation of acetabular posterior column plate technique / 中华外科杂志

<p><b>OBJECTIVES</b>To study the best entry points, direction and length of screw in acetabular posterior column plate technique, and to prevent the serious complications of screw penetrating the joint surface.</p><p><b>METHODS</b>February to July 2008 20 male cadaveric adult semi-pelvic specimen were taken.Serial cross-sections of the acetabular posterior column were determined and made. The safe angle of screw entry and the length on all entry points of each cross-section were measured. And put all data into software SPSS 10.0 for statistics process.</p><p><b>RESULTS</b>On margin of acetabulum, lateral-middle 1/4 point, midpoint, medial-middle 1/4 point and medial margin of posterior column of each cross-section, safe entry angle of inclination was 39 degrees , 57 degrees , 74 degrees , 90 degrees and 106 degrees respectively, the length of the screw was 39, 57, 74, 90 and 106 mm respectively.</p><p><b>CONCLUSION</b>On lateral 1/4 region, lateral-middle 1/4 region, medial-middle 1/4 region and medial 1/4 region, screw posterior column angle is 40 degrees to 60 degrees , 60 degrees to 75 degrees , 75 degrees to 90 degrees , 90 degrees to parallel to the quadrilateral plate, and the length of the screw is 30 mm.</p>

Treatment of chronic calcaneal osteomyelitis following internal fixation for calcaneal fractures / 中华创伤骨科杂志

Objective To study the treatment of the chronic calcaneus osteomyelitis combined with skin ulcers or defects of the posterior heel following internal fixation for calcaneal fractures.Methods From February 1999 to June 2005,17 cases of calcaneus osteomyelitis combined with skin ulcers or defects following internal fix- ation for their calcaneal fractures were treated with elimination of infection focuses and dead spaces,tissue trans- plants and continuous irrigation.Skin flaps or myocutaneous flaps were used to repair heel ulcers or defects and to fill the dead spaces.Drainage and irrigation tubes were placed into the flap covered areas to carry out the continuous irrigation.Results All the cases were followed up for 3 to 36 months(mean,25 months).All the grafts survived without recurrence of calcaneus osteomyelitis.Their posterior heels regained fair appearance.Thirteen cases obtained fine sensory recovery and friction tolerance and could walk with weight-bearing.Conclusion Calcaneus os- teomyelitis can be cured by simply and effectively tissue transplants and continuous irrigation,which can provide adequate anti-infection and improve blood circulation.