[Comparative study of proximal femoral shortening after the third generation of Gamma nail versus proximal femoral nail anti-rotation in treatment of intertrochanteric fracture]

[Concept evolution and research progress of stability reconstruction for intertrochanteric fracture]

Objective

To summarize the evolving concept and research progress on stability reconstruction in the surgical treatment of intertrochanteric fracture.

Methods

Related literature and author's own experience concerning the surgical treatment of intertrochanteric fracture were reviewed and analyzed in terms of fracture pathoanatomy, stable and unstable pattern, adequate and in-adequate reduction, primary and secondary stability, postoperative stability evaluation, and early weight-bearing.

Results

Intertrochanteric fracture occur at the translational area of cervico-trochanteric junction, which has a nature tendency to varus instability. Fracture reduction quality is the paramount factor and is evaluated by two views, the anteroposterior and lateral Garden alignment and cortex apposition between the head-neck fragment and the femoral shaft. Rather than the posteromedial lesser trochanteric frag ment, the cortical support concept (positive, neutral, negative) emphasizes the reduction of anteromedial cortex to a nonanatomic positive apposition or an "anatomic" neutral apposition in intraoperative fluoroscopy. Postoperative radiographic stability score provides a quantitative assessment for early weight-bearing standing and walking. However, some fractures may lose cortical contact and buttress (negative) during the process of postoperative telescoping and secondary stability. Further studies are needed to elucidate the risk factors such as tilting, swing or rotation of the head-neck fragment, and propose new preventive methods.

Conclusion

Stability reconstruction of intertrochanteric fracture requires adequate fracture reduction with Garden alignment and anteromedial cortical support apposition, and reliable sustainment by internal fixation implants. Early weight-bearing standing and walking is safe in patients with perfect postoperative stability score.

[Research progress on anteromedial cortical positive support reduction in treatment of intertrochanteric fracture]

Objective

To introduce the reduction concept of anteromedial cortical support in the treatment of intertrochanteric fracture, summarize the history, characteristics, biomechanics, and clinical applications, discuss the unsolved problems and prospect the future directions.

Methods

Relevant domestic and foreign studies on cortical support reduction of intertrochanteric fracture in recent years were reviewed. Conclusions were drawn combined with clinical experience.

Results

The positive cortical supportive reduction of intertrochanteric fracture, as a stable non-anatomical fracture reduction technique, has dual effects on mechanical buttress and biological bone healing. It does not increase the difficulty of doctors' surgical procedure. For patients, it decreases the loss of femoral neck length, the loss of neck-shaft angle, the incidence rate of coxa vara, and maintains stable mechanical structure of the pelvis. It also shows a lower rate of instrument-related complications, and higher limb function scores. The mechanical stability of medial cortex apposition is more important than that of anterior cortex. For the best stability of the fracture, both sides should get positive support reduction pattern.

Conclusion

Anteromedial cortical support reduction can improve the postoperative stability of intertrochanteric fracture, enable better imaging and functional prognosis. As a kind of non-anatomic form of functional reduction, it can be used as a suboptimal choice secondary to anatomic reduction.

[The measurement and clinical significance of the rotation angles of head-neck fragments after cephalomedullary nail fixation in intertrochanteric fractures]

OBJECTIVE

To measure the rotation angle of the head-neck fragment of intertrochanteric fracture after cephalomedullary nail fixation by three-dimensional CT imaging, and to explore its clinical significance.

METHODS

The clinical data of 68 patients with unstable intertrochanteric fracture of AO/Orthopaedic Trauma Association (AO-OTA) type 31-A2 treated with cephalomedullary nail fixation and with complete intraoperative fluoroscopy and postoperative three-dimensional CT imaging data between July 2016 and October 2018 were retrospectively analyzed. Among them, there were 21 males and 47 females, aged 68-93 years, with an average age of 81.8 years. There were 31 cases of AO/OTA type 31-A2.2 and 37 cases of 31-A2.3. Fracture reduction quality was evaluated according to Baumgaertner et al. and Chang et al. criteria. The anteromedial cortical contact or not of each patient was observed by three-dimensional CT imaging on T3DView software after operation. The rotation of head-neck fragments were divided into three types: non-rotation, flexion rotation, and hyperextension rotation. The rotation angles of each type were measured and the relationship between the rotation type of the head-neck fragments and the contact of the anteromedial cortex was analyzed.

RESULTS

The reduction and fixation of the small trochanter were not performed in 68 patients. According to Baumgaertner et al. criteria, the quality of fracture reduction was excellent in 15 cases (22.1%), acceptable in 50 cases (73.5%), and poor in 3 cases (4.4%). According to Chang et al. criteria, 31 cases were excellent (45.6%), 33 cases were acceptable (48.5%), and 4 cases were poor (5.9%). Thirty-nine cases (57.4%) received anteromedial cortical support and 29 cases (42.6%) did not receive cortical support. Three-dimensional CT imaging showed non-rotation in 12 cases (17.6%), flexion rotation in 39 cases (57.4%), and hyperextension rotation in 17 cases (25.0%). There were 7 cases (58.3%), 30 cases (76.9%), and 2 cases (11.8%) of cortical support in non-rotation group, flexion rotation group, and hyperextension rotation group, respectively. The rotation angles were (1.05±0.61), (13.96±6.17), (8.21±3.88)°, respectively. There were significant differences between groups ( P<0.05).

CONCLUSION

In the unstable intertrochanteric fracture after cephalomedullary nail fixation, the rotation of head-neck fragment exists in most patients, and the types of flexion rotation and non-rotation can easily obtain cortical support reduction.

[Clinical study on reduction of difficult-reducing intertrochanteric fracture with ball head screw driver of proximal femoral nail antirotation]

OBJECTIVE

To evaluate the effectiveness of the leverage reduction with proximal femoral nail antirotation (PFNA) ball head screw driver for difficult-reducing intertrochanteric fracture.

METHODS

The clinical data of 8 patients with difficult-reducing intertrochanteric fractures between July 2015 and February 2018 were retrospectively analysed. There were 3 males and 5 females, aged 66-89 years, with an average age of 76.3 years. According to Evans classification, there were 3 cases of type Ⅲ and 5 cases of type Ⅳ. The time from injury to operation was 2-8 days (mean, 3.9 days). All patients were reducted with ball head screw driver leverage through PFNA proximal incision during operation. The operation time, intraoperative blood loss, reduction time, and fluoroscopy times were recorded. Harris hip function score was used to evaluate the effectiveness at last follow-up.

RESULTS

The operation time was 52.5-83.7 minutes (mean, 68.1 minutes), the intraoperative blood loss was 49.8-96.4 mL (mean, 73.1 mL), the reduction time was 3.7-9.1 minutes (mean, 6.4 minutes), and the fluoroscopy times were 18.4-27.4 times (mean, 22.9 times). Patients were followed up 6-18 months (mean, 9.6 months). Postoperative X-ray films showed that the fracture obtained good reduction. No fracture displacement, fixation failure, and coxa vara occurred after operation. Fracture healing time was 3-6 months (mean, 4.6 months). At last follow-up, the Harris hip function score was 85-96 (mean, 91.6), with a result of excellent in 6 cases and good in 2 cases.

CONCLUSION

The reduction of difficult-reducing intertrochanteric fracture by using ball head screw driver can obtain good reduction and reliable fixation. The method has such advantages as no more incision, and less blood loss and soft tissue injury.