Comparison of the Radiological Results Between Linker-Guided and Navigation-Guided total Knee Arthroplasty

PURPOSE: To compare the accuracy of implantation by radiologic results between 3D Linker and navigation guided total knee arthroplasty. MATERIALS AND METHODS: Between February 2004 and April 2005, total knee arthroplasties were done in 25 knees with balanced gap-resection technique (group A) and 25 using kinematic navigation system(group B) by a single surgeon. All patients had standing long anteroposterior (AP) radiographs of the lower extremities and supine lateral radiographs of the knees at 6 weeks postoperatively. Mechanical axis deviation, alpha and beta, angles were measured on standing long leg AP views and alpha and beta angles on supine knee lateral views. Results were classified according to the deviation from the reference line and graded as excellent, good, and poor. The result was regarded as satisfactory when all five angles were excellent or good. RESULTS: The mean mechanical axis deviation was 1.11degrees in group A and 1.36degrees in group B and all were excellent in both groups. Regarding alpha.angles, 19 cases were excellent and, 6 good in group A and, 21 excellent and 4 good in group B. Regarding., angles, 22 cases were excellent and, 3 good in group A and, 23 excellent and 2 good in group B. Regarding.,, angles, 15 cases were excellent, 8 good and 2 poor in group A and, 15 excellent, 9 good, and 1 poor in group B. Regarding beta angles, 19 cases were excellent, 3 good and 3 poor in group A and, 23 excellent, and 2 poor in group B. There were no statistical differences between two groups in all five angles (p>0.05). An excellent implantation in all five angles was obtained in 28% in group A and 60% in group B (p0.05). CONCLUSION: Radiological results (mechanical axis and component angles) of total knee arthroplasty were satisfactory in 80% with balanced gap-resection technique and 84% with kinematic navigation system and showed no statistical difference.

A Comparison of Extramedullary and Intramedullary Femoral Component Alignment Guide Systems in TKA

PURPOSE: To compare a new extramedullary femoral alignment guide system with the conventional intramedullary alignment guide system for femoral component alignment in total knee arthroplasty(TKA). MATERIALS AND METHODS: From November 2004 to June 2005, a newly developed extramdullary technique was applied in 80 cases (EM group), which was compared to another 80cases (IM group) in which conventional intramedullary technique was used. Standing long leg anteroposterior (AP) radiographs were evaluated at postoperative 2 months to compare the alignment between the groups. And surgery time between two groups was compared. RESULTS: Femoral component alignment was 1.7+/-1.3degrees in EM group and 1.3+/-1.2degrees in IM group (p=0.025). Clinically acceptable femoral component alignment(<+/-3degrees) was achieved in 92% of EM group and 93% in IM group. The femoral component flexion angle was 3.9+/-2.3degrees delta in EM group and 5.5+/-2.7degrees delta in IM group (p<0.0001). The surgery time was 69+/-11.5 min in EM group and 68+/-11.7 min in IM group(p= 0.516). CONCLUSION: By using our EM technique, we could achieve a accurate alignment and similar surgery time compared with conventional IM technique, although it is not superior to IM technique. We think that our new extramedullary technique is a useful surgical method decreasing the complications of intramedullary canal injury.

Bilateral Total Knee Arthroplasties: Comparison of Simultaneous, Sequential, Staged Knee Replacement

PURPOSE: To compare the clinical outcomes of bilateral total knee arthroplasty (TKA) performed simultaneously by two teams or sequentially by one team under a single anesthesia, with those of staged bilateral TKA performed during separate hospitalizations. MATERIALS AND METHODS: We retrospectively analyzed 83 patients (166 knees) who underwent bilateral TKA. Group I comprised 25 patients receiving simultaneous bilateral TKA. Group II comprised 31 patients receiving sequential bilateral TKA. Group III comprised 27 patients receiving staged bilateral TKA spaced an average of 8.9 weeks apart. Data including complication rate, length of hospital stay, and allogenic blood transfusion rate were evaluated. RESULTS: Complication rate for group I, II, and III was 12%, 19.4%, and 25.9%, respectively, but there was no significant difference. Allogenic blood transfusion rate was 28%, 29%, and 11.1%, respectively, but there was no significant difference. The average hospital stay was 8.4 days, 8.9 days, and 14.5 days, respectively, and group I and II showed significantly shorter hospitalization compared with group III. CONCLUSION: Simultaneous or sequential bilateral TKA is a safe and efficient procedure that can shorten hospital stay without increasing complication rate and allogenic blood transfusion rate, compared with staged bilateral TKA.

Bone & Soft Tissue Injuries Diagnosed by Magnetic Resonance Imaging in Thoracolumbar Fractures

PURPOSE: To assess diagnostic efficacy of the MRI in thoracolumbar fractures, especially in changes of bone and soft tissue which cannot be documented by other diagnostic tools. MATERIALS AND METHODS: Among 85 patients managed for thoracolumbar fractures between January 1997 and June 2003, MRI was performed in 30 patients to get more informations. Plain X-ray, CT and MRI of these cases were reviewed retrospectively by two orthopaedic spine surgeons and one radiologist to investigate the informations which only MRI could afford. RESULTS: 14 (46.7%) among 30 patients had occult fractures of vertebrae other than main fracture which had not been diagnosed as fractured. Besides 6 patients who showed distraction of posterior structure on plain X-ray, injury of posterior ligament complex was confirmed by MRI in 12(40%) patients. Additionally, MRI visualized other soft tissue injuries such as intramuscular and subcutaneous hematoma, changes of the spinal cord and intervertebral disc. In 16 among 30 patients, informations achieved from MRI were the most important factors in deciding treatment modality. CONCLUSION: MRI seems to be efficient in visualizing not only soft tissue injury such as ligament but also occult fractures of additional vertebra in thoracolumbar fractures, therefore MRI seems to be an important diagnostic tool in decision of treatment modalities, especially in cases of uncertain stability.

The Effect of Shoe Lift on Lumbar Scoliosis Associated with Pelvic Obliquity / 대한척추외과학회지

STUDY DESIGN: A retrospective study designed to evaluate the effect of a shoe lift on the lumbar scoliosis associated with pelvic obliquity. OBJECTIVES: To analyze the changes in pelvic height, Cobb angle and clinical manifestations after application of a shoe lift. SUMMARY OF LITERATURE REVIEW: The most common form of scoliosis in adolescence is idiopathic (85% of scoliosis), which is a form of structural scoliosis. Some non-structural scoliosis may be assessed as an idiopathic form, which can result in an unnecessary treatment, such as bracing. Pelvic obliquity may be a cause of non-structural scoliosis, and a shoe lift may be used for its correction. MATERIALS AND METHODS: Twelve cases of lumbar scoliosis associated with pelvic obliquity, between April, 1998 and October, 2002, were investigated for the changes in the pelvic height and Cobb angle. Standing T-L AP and standing pelvic AP for measuring the Cobb angle and pelvic obliquity, respectively, were checked before and after application of a shoe lift. The Bell-Thompson method was used for measuring the limb length discrepancy. The shoe lift was composed of a compact cork pad and soft sponge tissue. The extent of a shoe lift was determined with the use of the most comfortable wood block height on stand-ing still. The radiological and clinical outcomes of the shoe lift were investigated. RESULTS: After the introduction of the shoe lift, 9 cases (75%) achieved a leveled pelvis (height difference less than 0.3cm) 1 week post-shoe lift. The mean Cobb angle before treatment was 16degrees ranging from 9 to 26degrees which was reduced to 6.7degrees ranging from 0 to 23degrees due to the shoe lift 1 week post-shoe lift. The mean correction of the Cobb angle after the introduction of a shoe lift was 73.9%. Clinically, 2 cases with low back pain achieved an improvement in the pain, and most patients expressed that walk-ing and standing had become more comfortable. CONCLUSION: A shoe lift seems to be significantly effective in correcting the Cobb angle and pelvic height in lumbar scoliosis associated with pelvic obliquity.