Objective To summarize the recent minimally invasive approach for cervical spondylotic radiculopathy (CSR). Methods The recent l iterature at home and abroad concerning minimally invasive approach for CSR was reviewed and summarized. Results There were two techniques of minimally invasive approach for CSR at peresent: percutaneous puncture techniques and endoscopic techniques. The degenerate intervertebral disc was resected or nucleolysis by percutaneouspuncture technique if CSR was caused by mild or moderate intervertebral disc herniations. The cervical microendoscopicdiscectomy and foraminotomy was an effective minimally invasive approach which could provide a clear view. The endoscopy techniques were suitable to treat CSR caused by foraminal osteophytes, lateral disc herniations, local l igamentum flavum thickening and spondylotic foraminal stenosis. Conclusion The minimally invasive procedure has the advantages of simple handl ing, minimally invasive and low incidence of compl ications. But the scope of indications is relatively narrow at present.
Objective To study the technique and effect of adjunctive cancellous screw in treatment of intertrochanteric fractures with dynamic hi p screw (DHS) fixation. Methods Between April 2004 and August 2007, 33 patients with intertrochanteric fracture were treated with DHS fixation and adjunctive cancellous screw. There were 13 males and 20 females, aging 43-82 years with an average age of 67 years. Fractures were caused by traffic accident in 7 patients, by fall ing from height in 11 patients, by sprain in 15 patients. All fractures were closed. The patients were operated 3-12 days after injury. According to Evans classification, there were 12 cases of type II, 15 cases of type III, and 6 cases of type IV. Twenty-twocases had osteoporosis. Weight bear time and compl ication were recorded. Fracture heal ing and neck-shaft angle were observed on radiogram. Hip functions were evaluated using Radford criterion. Results Thirty-three patients had no intraoperative compl ications with incision heal ing by first intension. All patients were followed up from 14 months to 38 months, with an average of 21 months. Fracture heal ing was achieved within 14 weeks to 21 weeks, with an average of 17 weeks after operations. The neck-shaft angles were (134.2 ± 13.7)° 3 days after operation, (128.6 ± 8.9)° 8 weeks after operation, and (128.5 ± 9.3)° after fracture heal ing, showing no significant difference when compared with that of the third day after operation (P gt; 0.05). According to the Radford criterion at last follow-up, the excellent and good rate of hi p function was 93.9% (excellent in 21 cases, good in 10 cases, and poor in 2 cases). Compl ications such as loosening, breakage, or grievous migration of hardware were not observed. Conclusion The adjunctive cancellous screw in treatment of intertrochanteric fractures with DHS fixation can provide counteraction of tension and rotation, promote fixation stabil ity, enhance fracture heal ing and decrease compl ication.
Magnetic induction method aims at the noninvasive detection of liver iron overload by measuring the hepatic magnetic susceptibility. To solve the difficulty that eddy current effects interfere with the measurement of magnetic susceptibility, we proposed an improved coil system based on the static field magnetization principle in this study. We used a direct current excitation to eliminate the eddy current effect, and a rotary receiver coil to get the induced voltage. The magnetic field for a cylindrical object due to the magnetization effect was calculated and the relative change of maximum induced voltage was derived. The correlation between magnetic susceptibility of object and maximum magnetic flux, maximum induced voltage and relative change of maximum induced voltage of the receiver coil were obtained by simulation experiments, and the results were compared with those of the theory calculation. The contrast shows that the simulation results fit the theory results well, which proves our method can eliminate the eddy current effect effectively.