Scoliosis Correction with Thoracic Pedicle Screws: Posteroanterior C-arm Rotation Method / 대한정형외과학회잡지

Purpose: This study evaluated a practical, safe and accurate method of thoracic pedicle screw insertion for the surgical treatment of scoliosis using the posteroanterior C-arm fluoroscopy rotation method. Materials and Methods: A total of 611 thoracic pedicle screws were inserted in 45 patients using the posteroanterior (PA) C-arm rotation method. CT scans were taken postoperatively in the transverse and sagittal sections to evaluate the pedicle screw placement. Results: A mean preoperative curve of 57.7o was corrected to 17.1o (range, 3o-45o) in the coronal plane. The postoperative CT scans revealed that 10 screws (1.6%) had penetrated the medial cortex by a mean distance of 3.0 mm and 56 screws (9.2%) penetrated the lateral cortex by a mean distance of 3.5 mm. No screw penetrated the inferior or superior cortex in the sagittal plane. However, 21 screws (3.4%) penetrated the anterior cortex. No neurological or vascular complications were encountered, and none of the screws required replacement. Conclusion: Thoracic pedicle screw insertion in scoliosis patients using the posteroanterior C-arm rotation method is a practical, simple and safe technique that allows the en face visualization of both pedicles by rotating the C-arm to compensate for the rotational deformity.

Thoracic Pedicle Screw Insertion in Scoliosis Using Posteroanterior C-arm rotation Method / 대한척추외과학회지

STUDY DESIGN: A prospective study of the accuracy of thoracic pedicle screws inserted in scoliotic patients. OBJECTIVES: To evaluate and present a practical, safe and accurate method for thoracic pedicle screw insertion in the surgical treatment of scoliosis using the posteroanterior c-arm fluoroscopy rotating method. SUMMARY OF LITERATURE REVIEW: Previous studies have emphasized the clinical importance, yet difficulty, of accurate thoracic pedicle screw insertion in scoliotic patients. Three-dimensional alterations in the pedicle orientation of scoliotic patients makes the accurate insertion challenging. No reports exist on the accuracy and benefits of posteroanterior c-arm fluoroscopy, which is rotated to allow visualization from en face, in real patients. MATERIALS AND METHODS: A total of 350 thoracic pedicle screws were inserted in 29 patients, including 24 with idiopathic scoliosis, using the posteroanterior (PA) c-arm rotation method. The smallest patient weighed 14 kg, and the next smallest 17 kg. The average preoperative curve was 60.9 degrees(range, 45 degrees~101 degrees). CT scans were taken, postoperatively, in the transverse and sagittal sections to evaluate the pedicle screw placement. RESULTS: The mean preoperative curve of 60.9 degrees was corrected to 15.4 degrees(range, 3 degrees~45 degrees) in the coronal plane, a correction of 74.7%. A mean of 12.1 thoracic screws were inserted per patient. On analysis of the postoperative CT scans, 39(11.1%) of the 350 screws penetrated the medial or lateral pedicle cortices, 8(2.3%) into the medial cortex and 31(8.9%) into the lateral cortex, by mean distances of 3.3 and 3.6 mm, respectively. No screws penetrated the inferior or superior cortices in the sagittal plane, but 16(4.6%) penetrated the anterior cortex. No neurological or vascular complications were encountered, and none of the screws required subsequent replacement. CONCLUSIONS: Thoracic pedicle screw insertion in scoliotic patients, using a posteroanterior c-arm rotation method, allows the en face visualization of both pedicles by rotating the c-arm to compensate for rotational deformity, which makes it a practical, simple and safe method.

Gap Discrepancy in Posterior Cruciate Ligament-Sacrificing Total Knee Joint Arthroplasty

PURPOSE: To evaluate the effects of PCL (posterior cruciate ligament) resection on the flexion and extension gap during TKA (total knee joint arthroplasty). MATERIALS AND METHODS: From December 2002 to August 2003, we quantitatively measured and ana-lyzed prospectively the flexion and extension gap before and after PCL resection during TKA in 26 cases among 23 patients of osteoarthritis. A tensioning device was used to measure the gap and a torque wrench attached to the device was used to apply constant force. RESULTS: Before resection, the average flexion gap was 24.9 mm and the average extension gap was 25.3 mm. After resection, the average flexion gap was 29.8 mm and average extension gap was 27.6 mm. The extension gap was increased 2.2 mm and the flexion gap was increased 4.9 mm which implies that using a thicker polyethylene insert would be favorable after PCL resection. CONCLUSION: After PCL resection, both flexion and extension gaps were increased but the flexion gap was increased more than the extension gap.

Prognostic Factors of Hemiarthroplasty for the Proximal Humeral Fractures / 대한정형외과학회잡지

PURPOSE: The purpose of the study was to evaluate the results and analyze various prognostic factors of hemiarthroplasty for proximal humeral fractures. MATERIALS AND METHODS: Thirty-one cases, who underwent hemiarthroplasties for proximal humeral fractures, were evaluated with ASES score at a mean follow-up of 45 months (1-8 years). Global Total Shoulder (Depuy.) (TS Gr) for 21 cases, and Global FX (Depuy.) (FX Gr) for 10 cases were used. Twentysix cases were acute fractures within one month after injury. There were two cases with delayed union and three cases with nonunion. Prognostic values of age, delay of surgery, fracture type, position of the greater tuberosity and design of implant were assessed. RESULTS: The most important prognostic factor was the design of implant. Mean score of FX Gr was significantly higher than that of TS Gr (84.4 and 77.6 respectively, p=0.036). Age, fracture type, delay of surgery and position of the greater tuberosity did not show any prognostic value. CONCLUSION: The clinical results of Hemiarthroplasty specially designed for the proximal humeral fractures has better than that of preexisting implant. Design of the implant was considered to be the most important prognostic factor of hemiarthroplasty for the proximal humeral fractures.