Kwang Jun Oh

Meta-Analysis Comparing Outcomes of Fixed-Bearing and Mobile-Bearing Prostheses in Total Knee Arthroplasty

Study findings have been inconsistent in confirming advantages for mobile-bearing compared with fixed-bearing prostheses for total knee arthroplasty. Therefore, we did meta-analysis of trials comparing outcomes from using the 2 different designs. Of 5670 citations identified for screening, 10 trials reporting 620 participants (906 knees) at final follow-up were eligible for data extraction and meta-analysis. The meta-analysis did not find a significant difference in the American Knee Society Knee Scores, Knee Society Functional and Pain Scores, range of motion, occurrence of radiolucent lines, prosthesis-related complications, and participant preference. The results suggest that the mobile-bearing prosthesis does not offer clinical or radiologic advantage over the fixed-bearing prosthesis.

Clinical and Radiologic Outcomes of Contemporary 3 Techniques of TKA

This report compares the radiologic and early clinical results of total knee arthroplasty (TKA) performed by the same surgeon using 3 techniques. In this prospective study, 75 knees were randomized to conventional technique (25 knees), image-free navigation system (25 knees), or minimally invasive surgery (MIS) (25 knees). Age range of the 43 women (65 knees) and 5 men (10 knees) was 58 to 81 years. Posterior stabilized knee prosthesis was used in all patients. Data was collected according to Knee Society System for radiologic evaluation of x-rays. Knee Society clinical (KS-C) and functional knee scores were measured preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years. The postoperative KS-C was not statistically better in the MIS group (mean, 88 ± 11.5; range, 70-100) than the conventional (mean, 85.9 ± 7.8; range, 74-94) (P=.68) or navigation group (mean, 85 ± 11; range, 63-100) (P=.59). Mean postoperative delta (mechanical axis) angle was significantly different (P=.014): 2.38° in the conventional group (SD=2.88°; 95% CI, 1.19°-3.57°; range, -1.59° to 6.86°), 0.61° in the navigation group (SD=2.07°; 95% CI, -0.24° to 1.46°; range, -2.07° to 4.25°), and 4.25° in the MIS group (SD=6.52°; 95% CI, 1.56°-6.94°; range, -6.72° to 15.60°). Significant difference could be elicited between navigation-assisted and MIS groups, with navigation-assisted surgery providing more accurate alignment of the mechanical axis (P=.014). Of the three techniques, navigation-assisted surgery gives superior prosthesis alignment and promising longevity of TKA.

Computed Tomography Assessment of Image-free Navigation-assisted Cup Placement in THA in an Asian Population

The authors hypothesized that an image-free navigation system would be more accurate than postoperative 3-dimensional (3-D) reconstructed computed tomography (CT) for acetabular cup inclination and anteversion during total hip arthroplasty (THA) in an Asian population. Eighty-one THAs were performed in 72 patients using the OrthoPilot image-free navigation system (B. Braun Aesculap, Tuttlingen, Germany). Cup placement position was measured by postoperative 3-D CT and compared with intraoperative navigation data. The discrepancies between the navigation data and the 3-D CT data were analyzed, as well as the correlation factors that affected the discrepancies. The discrepancies between the navigation data and the 3-D CT data were -1.5° ± 7.1° (P=.04) for anteversion and -1.1° ± 7.6° (P=.02) for inclination. The accuracy and precision of the anteversion discrepancies were 5.6° ± 4.4° and 3.2°, respectively. The accuracy and precision of the inclination discrepancies were 4.5° ± 4.4° and 2.8°, respectively. Five (6%) outliers existed in terms of the safe zones of anteversion and inclination. The main correlated factor among the pelvic geometry was tilt rather than rotation and obliquity of the bony anterior pelvic plane.In an Asian population, the calculated accuracy and precision of acetabular cup inclination and anteversion during THA were more reliable and the outliers were reduced using the OrthoPilot navigation system. However, discrepancies existed between intraoperative navigation data and postoperative 3-D CT data. The pelvic geometry of biometrical factors influenced the discrepancies in the navigation data.

The effect of post-operative immobilization on short-segment fixation without bone grafting for unstable fractures of thoracolumbar spine.

Background: Controversy regarding the fixation level for the management of unstable thoracolumbar spine fractures exists. Often poor results are reported with short-segment fixation. The present study is undertaken to compare the effect of fixation level and variable duration of postoperative immobilization on the outcome of unstable thoracolumbar burst fractures treated by posterior stabilization without bone grafting. Patients and Methods: A randomized, prospective, and consecutive series was conducted at a tertiary level medical center. Thirty-six neurologically intact (Frankel type E) thoracolumbar burst fracture patients admitted at our institute between February 2003 and December 2005 were randomly divided into three groups. Group I (n = 15) and II (n = 11) patients were treated by short-segment fixation, while Group III (n = 10) patients were treated by long-segment fixation. In Group I ambulation was delayed to 10th-14th postoperative day, while group II and III patients were mobilized on third postoperative day. Anterior body height loss (ABHL) percentage and increase in kyphosis as measured by Cobbs angle were calculated preoperatively, postoperatively, and at follow-up. Denis Pain Scale and Work Scales were obtained during follow-up. Results: Mean follow-up was 13.7 months (range 3-27 months). At the final follow-up the mean ABHL was 4.73% in group I compared with 16.2% in group II and 6.20% in group III. The mean Cobbs angle loss was 1.8° in group I compared with 5.91° in group II and 2.3° in group III. The ABHL difference between groups I and II was significant (P = 0.0002), while between groups I and III was not significant (P = 0.49). Conclusion: The short-segment fixation with amenable delayed ambulation is a valid option for the management of thoracolumbar burst fractures, as radiological results are comparable to that of long-segment fixation with the advantage of preserving maximum number of motion segments.

Three-level anterior cervical discectomy and fusion in elderly patients with wedge shaped tricortical autologous graft: A consecutive prospective series

Background: Treatment of multilevel cervical spondylotic myelopathy/radiculopathy is a matter of debate, more so in elderly patients due to compromised physiology. We evaluated the clinical and radiological results of cervical fusion, using wedge-shaped tricortical autologous iliac graft and Orion plate for three-level anterior cervical discectomy in elderly patients. Materials and Methods: Twelve elderly patients with mean age of 69.7 years (65–76 years) were treated between April 2000 and March 2005, for three-level anterior cervical discectomy and fusion, using wedge-shaped tricortical autologous iliac graft and Orion plate. Outcome was recorded clinically according to Odoms criteria and radiologically in terms of correction of lordosis angle and intervertebral disc height span at the time of bony union. The mean follow-up was 29.8 months (12–58 months). Results: All the patients had a complete recovery of clinical symptoms after surgery. Postoperative score according to Odoms criteria was excellent in six patients and good in remaining six. Bony union was achieved in all the patients with average union time of 12 weeks (8–20 weeks). The mean of sum of three segment graft height collapse was 2.50 mm (SD = 2.47). The average angle of lordosis was corrected from 18.2° (SD = 2.59°) preoperatively to 24.9° (SD = 4.54°) at the final follow-up. This improvement in the radiological findings is statistically significant (P < 0.05). Conclusion: Cervical fusion with wedge-shaped tricortical autologous iliac graft and Orion plate for three-level anterior cervical discectomy is an acceptable technique in elderly patients. It gives satisfactory results in terms of clinical outcome, predictable early solid bony union, and maintenance of disc space height along with restoration of cervical lordosis.