Incidence of femoral neck shortening after internal fixation of femoral neck fracture and prognostic factors / 中国组织工程研究

ABSTRACT

BACKGROUND: Internal fixation with cannulated screws is the most commonly used treatment for femoral neck fracture, but some patients may have the phenomenon of femoral neck shortening after surgery, and even cause the occurrence of postoperative dysfunction of the hip joint. OBJECTIVE: To investigate the incidence, clinical features, prognosis and influencing factors of femoral neck shortening after internal fixation of femoral neck fracture. METHODS: One hundred and eleven cases of femoral neck fracture treated by cannulated screw internal fixation at three orthopedic hospitals in Chengdu from January 2012 to March 2017 were retrospectively analyzed. All patients signed the informed consents and the study was approved by the ethics committee of the hospital. Femoral neck shortening was as the prognostic indicator. The incidence, occurrence time and main clinical characteristics of femoral neck shortening after surgery were recorded. Univariate chi-square test was used to analyze the correlation between sex, age, Garden type, Garden index, bone mineral density T value, Singh index, time from injury to operation, weight-bearing time and the femoral neck shortening after surgery. Statistically significant factors were included in the multivariate Logistic regression model. RESULTS AND CONCLUSION: (1) The incidence of femoral neck shortening was 48.6% (54/111), with 31.5% (35/111) of 10-19 mm shortening and 5.4% (6/111) of ≥ 20 mm shortening. (2) The occurrence time of femoral neck shortening was mainly within 6 months after surgery, accounting for 76%. (3) The clinical manifestations of the femoral neck shortening mainly included pain during weight-bearing, dysfunction of hip movement and claudication. The analysis results showed that the moderate pain (67%) was dominant in the shortening group, and no pain/mild pain (86%) was dominant in the non-shortening group; the incidence of hip motion limitation in the shortening group was higher than that in the non-shortening group (68% vs. 21%); and the incidence of claudication in the shortening group was higher than that in the non-shortening group (61% vs. 18%); the differences were significant (all P < 0.05). (4) Univariate and multivariate Logistic regression analysis showed that Garden classification of fracture was type III and IV, Garden index was grade III and IV, bone mineral density T value ≤ -2.5, weight-bearing time ≤ 2 months were independent risk factors for femoral neck shortening after reduction and internal fixation of femoral neck fracture. Therefore, there is a high risk of femoral neck shortening after internal fixation with cannulated nails for femoral neck fractures, which mainly occurs within 6 months after surgery.