Objective To investigate the effectiveness of absorbable pins for reconstructing pelvic stability in Salter innominate osteotomy for treating development dysplasia of the hip (DDH). Methods Between January 2003 and December 2008, 392 patients (440 hips) with DDH underwent a Salter procedure. There were 68 boys (82 hips) and 324 girls (358 hips) with a mean age of 3 years and 3 months (range, 1 year and 6 months-5 years). According to Tonnis classification criteria, 13 hips were rated as grade I, 304 hips as grade II, 82 hips as grade III, and 41 hips as grade IV. Based on the degree of displacement of the femoral head and acetabular index on the anteroposterior pelvic X-ray film, operation method was selected before operation. A total of 341 hips were managed with open reduction and Salter innominate osteotomy, and 99 hips with Salter innominate osteotomy and femoral shortening rotating osteotomy. All cases underwent autologous iliac crest grafting and fixation between osteotomy sites and bone graft with 2 absorbable pins. Results At 1 day after operation, anteroposterior pelvic X-ray examination showed concentric reduction in all hips, having no instability of the joint of the osteotomy sites or bone graft shifting. A total of 368 patients (413 hips) were followed up 1 to 7 years (mean, 3 years and 10 months). At 3 months after operation, no bone graft in stability or shift, and sliding or loosening of pins occurred. At last follow-up, concentric reduction rate was 100%; after hip loading, 358 patients had no claudication and limited hip activities, who had the stability of hips and negative Allis and Ortalani signs. No abnormal height growth was observed in all patients. According to Mckay’s hip function evaluation criteria, the results were excellent in 390 hips, good in 16 hips, and fair in 7 hips, with an excellent and good rate of 98.3%; according to Severin X-ray criteria, the results were excellent in 386 hips, good in 17 hips, and fair in 10 hips, with an excellent and good rate of 97.6%. Conclusion Absorbable pins can replace steel pins for fixation of the osteotomy sites and bone graft in Salter innoninate because of flexible and convenient operation without a need for reoperation of steel pins extraction.
Objective To investigate the effect of ultrasonic irradiation time on enhanced green fluorescent protein (EGFP) gene transfection efficiency and local tissue in bone defects using ultrasound-mediated microbubble destruction. Methods Thirty 3-month-old New Zealand rabbits (2.5-3.0 kg in weight) were randomly divided into 5 groups (n=6) and bone defect models were made on the right ulna. At 10 days after modeling, suspension of microbubbles and EGFP plasmids were locally injected (0.3 mL/kg) and then ultrasound was performed on defect at a frequency of 1 MHz, a intensity of 0.5 W/cm2, and a duty ratio of 20% for 1, 2, 3, 4, and 5 minutes respectively (in 1, 2, 3, 4, and 5 minutes groups respectively). The survival condition was observed. Rabbits were sacrificed for gross observation at 7 days after transfer. The gene expression was observed by fluorescence staining. HE staining and transmission electron microscopy were used to observe the local tissue damage. Results The animals all survived. New soft tissue formed in bone defects area at 1 week after transfer, the surrounding muscle tissue was partly filled in it. Green fluorescence expression was observed in all rabbits. The expression was the strongest in 2 minutes group, and was the weakest in 1 minute group. The absorbance (A) value showed significant differences when compared 1 minute and 2 minutes groups with other groups (P<0.05), but no significant difference was found between 3, 4, and 5 minutes groups (P>0.05). Tissue damage was observed in all groups and it was aggravated with the increase of irradiation time. Conclusion EGFP transfection efficiency in bone defect by ultrasound-mediated microbubble destruction is related to irradiation time. EGFP gene can be efficiently transfected without obvious toxicity at 1 MHz, 0.5W/cm2, and duty ratio of 20% for 2 minutes in bone defects of rabbits.
Objective To investigate the effectiveness of the acetabular reconstruction surgery in children pathological dislocation of the hip joint. Methods Between January 2006 and January 2011, 59 patients (59 hips) with pathological dislocation were treated by open reduction combined with acetabular reconstruction surgery. There were 22 boys and 37 girls, aged from 1 to 15 years (mean, 4.9 years). There were 9 cases of hip subluxation and 50 cases of hip joint dislocation, which were caused by suppurative arthritis of the hip (33 cases) and tuberculosis of the hip (26 cases). The diseases duration ranged from 1 month to 10 years. At preoperation Harris hip score was 43-78 (mean, 61); 14 cases had normal acetabular index (AI), 32 cases had slightly increased AI, and 13 cases had significantly increased AI. The concomitant diseases included acetabular destruction in 28 cases; avascular necrosis of the femoral head in 25 cases, femoral head partial defect in 12 cases, femoral head complete defect in 6 cases, and femoral head and neck defects in 3 cases; 25 cases had increased anteversion angle; and 9 cases had varus deformity. Results Immediately postoperative X-ray films showed center reduction in all the hips. Healing of incision by first intention was achieved in 55 cases, and delayed healing in 4 cases. Fifty-three children were followed up 2 to 5 years (mean, 3 years). No re-dislocation of the hip occurred during follow-up. Thirty-eight cases had normal AI, 15 cases had slightly increased AI. The anteversion angle was 15-25 ° (mean, 20 ° ); the neck shaft angle was 110-140 ° (mean, 125 ° ); and the anatomical relation between the head and neck returned to normal. After 2 years, 18 cases had normal function of the hip joint; 30 cases had mild limitation of flexion and rotation; and 5 cases had fibrous ankylosis. The Harris hip score was 62-95 (mean, 87). Conclusion Pathological dislocation caused by neonatal acute suppurative arthritis of the hip and the hip joint tuberculosis is often associated with severe bone destruction and deformity of the acetabular and femoral head and neck. Treatment should strictly follow the principle of individual. Proper acetabular reconstruction should be selected according to pathological changes of the hip; if combined with the femoral head and neck reconstruction processing, the satisfactory results can be obtained.