Therapeutic evaluation of the correction of the severe bi-maxillary protrusion cases by Tweed-Merrifield technique / 北京大学学报(医学版)

Objective:To evaluate the influence of Tweed-Merrifield technique in correction of severe bimaxillary protrusion adult patients on the measurement of the dental and skeletal changes after orthodon-tic treatment by Johnston analysis and the regular cephalomatric analysis.Methods:Twelve adolescent patients with severe bimaxillary protrusion were included in this self-control retrospective study.Lateral cephalometric radiographs were taken before and after treatments.All the radiographs were traced and analyzed by the method of Johnston analysis.Other measurements were evaluated using a series of 1 3 li-near and angular measurements including SNA,SNB,ANB,U1 -SN,U1 -NA,U1 /NA,L1 -NB, U1 /NB,L1 /MP,U1 -L1 ,(U1 +L1 )/2-AB,MP/SN and MP/FH from regular cephalomatric analysis. These measurements were also applied to compare the differences between pre-and post-treatments,which clarify the dental and skeletal changes by Johnston analysis.The effect of orthodontic correction was de-termined using the non-parameters test.Results:The maxillary moved backforward by 1 .3 mm according to the stable skull base,while the mandible moved forward by 2.1 2 mm.The relative position between the maxillary and mandible (ABCH)changed 3.42 mm.The upper and lower incisors retracted signifi-cantly.The upper and lower molars moved slightly forward and the relative positions of upper and lower molars and anterior teeth after treatment were 3.44 mm and 4.23 mm respectively.After treatment,the parameters of ANB、U1 -NA、U1 /NA、U1 -SN、L1 -NB、L1 /NB and L1 -M were reduced by -(1 .98 ± 1 .55)°(P =0.01 2),-(5.08 ±4.6)mm (P =0.002),-(1 1 .79 ±1 .21 )°(P =0.004),-(1 3.55 ±6.32)°(P =0.047), -(3.1 7 ±3.07)mm (P =0.01 0), -(6.84 ±2.55)°(P =0.038)and-(4.1 3 ±2.24)°(P =0.048)on average,whose changes had the statistically significant effects.Con-clusion:Tweed-Merrifield technique (directional force technique)can stabilize anchorage molar,retract anterior teeth and significantly improve the hard and soft tissue profile for patients with bimaxillary protru-sion,and make a good vertical control which means this technique is applicable to the patients who need strong anchorage.Even for the severe bimaxillary protrusion adult patients,the Tweed-Merrifield tech-nique can control the anchoragewell and make the profiles improved greatly.

Preliminary results of the interspinous implants for treatment of lumbar degenerative diseases / 中华骨科杂志

Objective To describe our initial experience and evaluate the preliminary results as well as the possible complications of interspinous implant (device for intervertebral assisted motion, DIAMTM) in managing symptomatic lumbar degenerative disorders. Methods A group of 22 patients were analyzed ret-rospectively. Fourteen female and eight male patients were treated. Mean age was 38.5 (range, 24 -59) years. They had clinical evidence for lumbar facet joint pain and a facet joint injection therapy had good result. Pre-operatively MRI and CT scan was done to evaluate the lumbar spinous process, lumbar disc and facet joints. Fourteen patients were operated at single level, eight patients at double levels. Radiographic imaging, pain scores, and clinical assessments were obtained at 24th week, 66th week postoperatively. Results Pa-tients were evaluated clinically through the Odom's criteria: 31.8% (7 patients) excellent, 45.4% (10 patients) good, 4.5% (1 patient) fair and 18.1% (4 patients) poor results. A significant difference was observed in im-provement of visual analogue scale that decreased from preoperative mean 7.09±0.92 to postoperative mean 3.23±1.82. Statistically significant differences were noted in neural foraminal height and posterior disc height when comparing patients pre-and postoperatively. For the follow-up period, no migration and loosening of implant was found, and no revision surgery was needed in all cases. Conclusion In this preliminary result, it could be observed that the DIAMTM prosthesis can offer a pain relief in well selected patients suffering lum-bar facet joint pain. The indication should be very strict. The implant acts as: 1) A shock absorber, give dis-traction of the neuroforamina, realign facet interface; 2) Restore posterior column height and share in load transmission.

Treatment of periprosthetic femoral fractures after total hip arthroplasty / 中华骨科杂志

Objective To analyze the causes and results of treatment of periprosthetic femoral frac-tures after total hip arthroplasty and to explore the best operative methods for fractures. Methods 11 cases treated for periprosthetic femoral fracture after total hip arthroplasty were subjected to a retrospective fol-low-up study from December 1998 to March 2003. There were 8 men and 3 women, the mean age was 56 years (range, 43 to 75 years). There were 2 Vancouver A type fractures, 7 B2 type, 1 B3 type, 1 C type. 5 fractures were treated by nonoperative methods and other 6 by operative methods, including one fracture malunion treated initially by skin traction. There were 5 revisions using long stem supplemented with cortical allograft strut, including 4 uncemented stems with distal fixation and one cemented stem; the remaining one fracture treated by open reduction and internal fixation. Results None was lost for follow-up. The mean follow-up period was 25.6 months (range, 7 to 50 months). 9 fractures united at a mean of 4 months (range, 3 to 6 months). Nonunion was found in 2 fractures, both were treated nonoperatively. All the 6 fractures treated by operative methods united. Up to now, 7 stems were well-fixed, continuous radiolucent line was seen in one revision case, 3 stems were loosened. The function of the patients with well-fixed stems was bet-ter than those with loosened stems, the mean Harris score of the former was 91. All the cortical allograft struts were incorporated with host bone within one year. No strut fracture happened. Conclusion Type A fractures with well-fixed stems can be treated by nonoperative methods, while type B1 and type C fractures should be treated by open reduction and internal fixation, on condition there is no surgical contraindication. For fractures with loosened stems, use of an uncemented long stem with distal fixation supplemented with cortical allograft strut is the best choice.

Total hip replacement in patients with congenital dislocation of hip / 中华骨科杂志

Objectiv e To evaluate the mid-term and long-term clinical outcome of total hip re-pl ace ment in patients with hip congenital dislocation.Methods From June198 3to Decem ber1998,36hips in32patients di agnosed as congenital disloca tion of hip(CDH),aged22to69years old(with the mean of 48.5years), were treated with total hip replacement (THR).Thirty-one hips of 28patient s were fol lowed-up with the duration of 9.5years(3.5to18years).Ac c ording to our system,the congen ital dys-pla sia of hip was divid ed into th ree degrees:the first degree was subluxation in15hips,the second degree was in termedi ate dislo cation in11hips,and the third degree was high dislocatio n in5hips.The fixation of the prosthetic compo nents was as follows :10cup s and12stems with cement,21cups and19stems with un-cement.In acetab ula r preparation,most of the patients with subluxation(13hips)underwent deep ening of the acetabu lum and were installed with larger cups;deepening of the acetabulum,smaller cup and auto femoral grafting on the su perior lip fixed w ith screws were performed in2hips with subluxation and all of hips with interm e di ate and high dislocation.Results The complications included intra operativ e lesser trochanter fracture in1case,deep vein thrombosis and thromboembolism of femoral artery in1case re spec-tively,limb discrepancy in3cases,asepti c loosening in4cases(1with trochanteric nonunion and migration,1with stem l oosening and2with both stem and cup loosening).The Harrisscore was85in th e other27hips(48scores before surgery).Con clusion Total hip replacement in patients with congenital dislocation of hip could be some what difficult be cause of the liability to complications.The techni cal difficulties en coun-t ered during surgery in cluded the correction of the length of bilateral lower extremi ty,the balance of the abductor muscles,the re lease of the soft tis sue,the dealing of the su perior segmental defect of acetabulum and selectio n of the compo nents.