Clinical Significance of Combined Weight-Bearing and Non-Weight-Bearing Positions and MRI Examination in Evaluating Genu Varus.

OBJECTIVE: To siscuss the clinical significance of the early diagnosis of knee varus and knee osteoarthritis with the combination of negative position and non-negative position and radiography.
METHODS: One hundred and eighty patients whose femorotibial angles <182° (genu varus positive) measured by X-ray at the weight-bearing position and femorotibial angles ≥182° (genu varus negative) measured by X-ray at the non-weight-bearing position were selected as the sample group from those patients who received knee joint Magnetic resonance imaging (MRI) examination from July 2015 to July 2017. One hundred and eighty patients whose femorotibial angles ≥182° (genu varus negative) measured at both the weight-bearing position and the non-weight-bearing position were selected as the control group. Femorotibial angles of both groups were respectively measured, to respectively compare and analyze the effect of non-weight-bearing false-negative genu varus on the occurrence and severity of injury of medial meniscus and femorotibial articular cartilage. The two groups of patients had no previous history of knee surgery, and no lower limb fracture, inflammation, tumor, metabolic bone disease, or congenital disease.
RESULTS: The weight-bearing tibiofemoral angles of the non-weight-bearing false-negative genu varus group and the negative genu varus group (180.998° ± 0.589°) were lower than the non-weight-bearing tibiofemoral angles (182.501° ± 0.290°), and they were positively correlated (t = -15.048, P < 0.01). The non-weight-bearing knee varus medial meniscus incidence of false- negative group. Medial meniscus injury that occurred in the sample group were 86.7% (156/180) in the anterior horn, 91.7% (165/180) in the body, 88.3% (159/180) in the posterior horn. Medial meniscus injury that occurred in the control group were 46.7% (84 /180) in the anterior horn, 40.6.3% (73/180) in the body, 43.3% (78/180) in the posterior horn. The incidence of degenerative groups, the differences were statistically significant. The incidence and severity of injury were as follows: medial meniscus anterior horn (χ2 = 41.966, P = 0.000), body (χ2 = 104.94, P = 0.000), posterior horn (χ2 = 81.025, P = 0.000). The incidence and severity of medial meniscus injury in the non-weight-bearing knee varus false negative group was higher than in the control group. The non-weight-bearing knee varus false-negative group medial tibiofemoral articular cartilage degeneration rate was 95.0% (171/180); in the control group, medial tibiofemoral articular cartilage degeneration was 65.1% (117/180). Two medial tibiofemoral articular cartilage degeneration incidence were statistically significant. The incidence and severity of injury were as follows: medial tibiofemoral articular cartilage (χ2 = 50.625, P = 0.000). The incidence and severity of medial tibiofemoral articular cartilage injury in the non-weight-bearing knee varus false negative group was higher than in the control group.
CONCLUSION: The combined weight-bearing position and non-weight-bearing position imaging examination for diagnosing the non-weight-bearing false-negative genu varus patients at an early date is of significant importance to the early diagnosis and treatment of knee osteoarthritis.