Factors Correlated with the Reducibility of Varus Deformity in Knee Osteoarthritis: An Analysis Using Navigation Guided TKA

BACKGROUND: We hypothesized that a number of clinical and radiologic parameters could influence the reducibility of varus deformity in total knee arthroplasty. The aim of this study was to identify the factors correlated with reducibility of varus deformity and predict more accurately the amount of medial soft tissue release required in varus deformity total knee arthroplasty. METHODS: One hundred forty-three knees with preoperative varus alignment and medial osteoarthritis were included in this retrospective study. The total knee arthroplasties were performed using a navigation system (OrthoPilot) by single surgeon. To assess varus deformity, the authors measured preoperative mechanical axis angles and valgus stress angles. Mechanical tibial angles, mechanical femoral angles, femoral osteophyte sizes, and tibial osteophyte sizes were measured. The Ahlback grading scale was applied for radiologic parameters, and clinical parameters (age, body mass index, sex, duration of pain, and preoperative range of motion) were documented. Correlations between these factors and preoperative valgus stress angle were analyzed. RESULTS: A negative correlation was found between preoperative mechanical axis angle and preoperative valgus stress angle (p < 0.01, r = -0.38), and a positive correlation was found between the preoperative mechanical tibial angle and preoperative valgus stress angle (p = 0.01, r = 0.19). CONCLUSIONS: The present study shows that preoperative varus deformity and proximal tibial vara (measured by preoperative mechanical axis angle and mechanical tibial angle, respectively) are correlated with reducibility of varus deformity (measured by preoperative valgus stress angle), and clinical parameters (age, range of motion, duration of pain and body mass index) and other radiologic parameters (osteophyte size, severity of osteoarthritis and angulation of distal femoral joint surface) were not significantly correlated with reducibility of varus deformity.

Comparison between Vertebroplasty and Kyphoplasty in Osteoporotic Vertebral Compression Fractures / 대한정형외과학회잡지

PURPOSE: To compare the outcome of vertebroplasty with kyphoplasty in the treatment of painful osteoporotic vertebral compression fractures. MATERIALS AND METHODS: From May 2002 through April 2004, 55 patients were analyzed. Vertebroplasties were performed on 29 patients under local anesthesia. The patients were divided into two groups: group I consisted of 15 patients who underwent vertebroplasties within two weeks from the onset of the fractures; group II consisted of 14 patients who underwent kyphoplasties after two weeks from the onset of the fractures. Kyphoplasties were performed on 26 patients under general anesthesia. These patients were also divided into two groups, based on the same criteria as those patients who underwent vertebroplasties. For the radiological assessment, we measured the kyphotic angle with Cobb's method and the reduction rate in the anterior, middle, and posterior portions of the vertebral bodies. The clinical results were assessed with the Oswestry Disability Index and Visual Analogue Scale. RESULTS: The reduction rates of the anterior and middle portions of the vertebral bodies were greater than 50 % in patients who underwent vertebroplasties within two weeks from the onset of the fractures and the patients who received kyphoplasty. The reduction rates of the anterior and middle parts of the vertebral bodies in patients who underwent vertebroplasties after two weeks from the onset of the fractures, was much less than in other three groups. There were no significant differences in clinical comparison among the 4 groups: i.e., all the patient had satisfactory results in terms of pain relief and pre-fracture activity levels. CONCLUSION: We obtained better results from kyphoplasties when we compared vertebroplasties with kyphoplasties, regardless of the operation dates. However, when we performed vertebroplasties within two weeks from the onset of the fractures, we obtained radiological results that were similar to those with kyphoplasties. In clinical comparison, there were no statistically significant differences among the 4 groups. The pain scores improved dramatically after the operations and pre-fracture activity levels resumed.