Suture anchor for acute injuries of medial collateral ligament of knee at degree III / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate clinical efficacy of suture anchors in treating acute injuries of medial collateral ligament (MCL) of knee at degree III.</p><p><b>METHODS</b>Twenty-seven patients with degree III acute MCL injuries of knee were treated with suture anchors from January 2007 to June 2011. There were 15 males and 12 females, aged from 19 to 56 (averaged 32.6) years old. The time from injury to operation was 3 to 10 days, averaged 6 days. Symptoms and physical signs before and after treatment were observed, Lysholm scoring were used to evluated clinical efficacy.</p><p><b>RESULTS</b>All patients were followed up from 16 to 30 months with an average of 21.6 months. The stability of knee joints was good in all patients. Abduction stress test was negative when the knee joint was straightened at 0 degrees and flexed at 30 degrees. The average degree of flexed knee (67.00 +/- 5.80) degrees preoperatively was lower than that of postoperatively (136.50 +/- 6.30) degrees at 1 year. According to Lysholm scoring, preoperative scores ranged from 30 to 43 points, averaged 36.46 +/- 1.48; 1 year after operation ranged from 87 to 100 with an average of 91.50 +/- 3.80 and higher than postoperative. Twenty patients got an excellent results, 5 good and 2 fair.</p><p><b>CONCLUSION</b>Suture anchors in treating acute injuries of medial collateral ligament of knee at degree III has following advantages: small range of tissue dissection, easy to operate, reliable fixation and less complications.</p>

Surgical treatment of thoracolumbar fractures using reduction and short-segment pedicle screw at the fracture level with the approach through para-vertebral muscles / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the efficacy and clinical outcome of reduction and pedicle screws fixation at the fracture level with the approach through para-vertebral muscles in treating thoraeolumbar fractures.</p><p><b>METHODS</b>From January 2007 to March 2010,27 patients with thoracolumbar fractures were treated with posterior open reduction and internal fixation with the approach through para-vertebral muscles. There were 19 males and 8 females with the mean age of 36.3 years old (ranged,21 to 57). According to Magerl type, type A2 was in 5 cases, A3 in 14, B1 in 3, B2 in 5. According to Frankel classification of spinal cord injury: grade D was in 6 cases and grade E in 21 cases. X-rays and CT scans were performed after operation. Cobb angle of the injured vertebral segment,the percentage of vertebral compression,and sagittal diameter stenosis rate of the injured spinal canal were observed by radiographic data. Neurological function was evaluated by the Frankel grade.</p><p><b>RESULTS</b>All patients were followed up from 12 to 28 months with an average of 19.6 months. The percentage of vertebral compression, Cobb angle of the injured vertebral segment, spinal canal sagittal diameter stenosis rate were respectively corrected from (46.6 +/- 10.5)%, (18.3 +/- 7.2) degrees, (30.2 +/- 7.2)% to postoperative (5.2 +/- 3.7)%, (5.3 +/- 5.1) degrees, (6.3 +/- 4.2)% and (6.7 +/- 4.6)%, (7.1 +/- 3.1), (7.2 +/- 4.5)% at last follow-up. There were significant difference in above items between preoperation and postoperation (P < 0.05); and there was no significant difference in above items between postoperation and last follow-up (P > 0.05). In aspect of nerve function, 3 cases with Frankel grade D recovered to grade E.</p><p><b>CONCLUSION</b>Using reduction and short-segment pedicle screws fixation at the fracture level through para-vertebral muscles approach is an effective method in treating thoracolumbar fractures. The method has advantages of simple operation,easy establishing screw, short operative time, less blood loss, which can obtain good reduction and stable, reliable fixation after operation.</p>

Pedicle screw at the fracture level and vertebroplasty via paraspinal approach for the treatment of old thoracolumbar fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility and safety of the treatment for thoracolumbar fractures with pedicle screw at the fracture level and vertebroplasty via paraspinal approach.</p><p><b>METHODS</b>From August 2007 to August 2010, 22 old patients with thoracolumbar fractures were treated with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. There were 14 males and 8 females, ranging in age from 60 to 71 years (mean, 64.6 years). The time from injury to surgery varied from 1 to 4 d (mean,2.7 d). All the patients suffered from single thoracolumbar fractures and located at T11 in 2 cases, at T12 in 5 cases, at L1 in 11 cases and at L2 in 4 cases. According to the Denis fracture classification, there were 6 compression fractures and 16 burst fractures. The mean preoperative load-sharing classification of spine fractures was 5.4 score. The mean preoperative thoracolumbar injury classification and scoring was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases,grade C in 3 cases, grade D in 7 cases and grade E in 10 cases. The neurological function, vertebral central and anterior height, kyphotic angle of the vertebral fractures by radiographs and visual analog scale were calculated pre-operatively, post-operatively and at the last follow-up.</p><p><b>RESULTS</b>Median operating time was 60.8 min (ranged from 50 to 95 min) and median blood loss was 84 ml (ranged from 50 to 130 ml). The operative incisions were healed well. The duration of follow-up averaged 21.6 months (ranged from 12 to 48 months). The anterior vertebral body height was corrected from preoperative (52.3 +/- 10.3) % to postoperative (6.1 +/- 4.2) % and (6.8 +/- 5.4) % at the last follow-up. The central vertebral body height was corrected from preoperative (38.9 +/- 11.2) % to postoperative (8.3 +/- 4.7) % and (9.4 +/- 4.5)% at the last follow-up. The Cobbs angle of the injured vertebral segment was corrected from preoperative (19.5 +/- 9.5) degrees to postoperative (4.3 +/- 4.1) degrees and (6.2 +/- 4.7) degrees at the last follow-up. The VAS scores reduced from preoperative 8.56 +/- 0.88 to post-operative 3.48 +/- 0.91 and 3.20 +/- 0.92 at the last follow-up. The postoperative neurologic function of all 22 patients improved 1 to 2 degrees except 10 patients of grade E. There were no instances of instrumentation failure and no patient had persistent postoperative back pain.</p><p><b>CONCLUSION</b>The pedicle screw at the fracture level and vertebroplasty via paraspinal approach has the advantages of less invasive and blood loss, and could prevent the development of kyphosis and offers improvement of the spinal cord function. Furthermore, it could decrease the risks of postoperative back pain and the failure of instrumentation.</p>

The cup safe-zone and optimum combination of the acetabular and femoral anteversions that fulfills the desired range of motion of the hip / 中国骨伤

<p><b>OBJECTIVE</b>To investigate safe range of acetabular prosthesis angle and the optimum combination of cup and neck in the range of activities of daily living (ADL).</p><p><b>METHODS</b>A three-dimensional generic parametric and kinematic simulation module of THA was developed. Range of motion (ROM) of flexion > or = 110 degrees, internal-rotation > or = 30 degrees at 90 degrees flexion, extension > or = 30 degrees and external rotation > or = 40 degrees were defined as the normal criteria for desired ROM for activities of daily living (ADL), and ROM of flexion > or = 120 degrees, internal-rotation > or = 45 degrees at 90 degrees flexion, extension > or = 30 degrees and external rotation > or = 40 degrees as the severe criteria. The range of the changes in the general head-neck ratios (GR), the femoral neck anteversion (FA), the operative anteversion (OA) and operative inclination (OI) of the cup component were 2-2.92, 0 degrees-30 degrees, 0 degrees-70 degrees, 10 degrees-60 degrees respectively. For the collodiaphyseal angle (CCD) of 135 degrees, the corresponding OA related to the OI which every 5 degrees was calculated, and described using dots and lines in a coordinate system in which OI of acetabular cup was the horizontal ordinate and OA of acetabular cup was the vertical ordinate. All data was analyzed by SAS 6.12 software.</p><p><b>RESULTS</b>Large GR greatly increased the size of safe range and it was recommended that GR be more than 2.37 when the CCD-angle was 135 degrees as it further increases the size of safezone. The size of cup safety range of the severe criteria was smaller than normal criteria. When the CCD-angle was 135 degrees, the optimum relationship between OA of acetabular and FA of the normal criteria and the severe criteria can be estimated by the formula: Y1=-0.816X1 + 39.76 (R2=0.993), Y2=-0.873X2 + 47.04 (R2=0.999) respectively.</p><p><b>CONCLUSION</b>Large GR greatly increases the size of safe-zone and it is recommended that GR be more than 2.37, so it extends the acceptable range of error that clinicians cannot avoid it completely. The larger range of the hip motion, the smaller size of the cup safe-zone,but can retrieve by increase the GR. The OA is negative with FA.</p>