Objective To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. Methods Based on CT data of a healthy adult male volunteer’s femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. Results The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. Conclusion For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.
Objective To compare the efficiency of secondary total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH) after failed internal fixation of femoral neck fracture and the primary THA for non-traumatic ONFH and to evaluate if the two groups have significant difference. Methods From June 2004 to July 2007, 203 cases of ONFH were treated by THA. In group A, 83 patients (83 hips) with ONFH after failed internal fixation included 56 males (56 hips) and 27 females (27 hips) with an average age of 58.3 years (range 45-75 years). According to Ficat classification, there were 61 cases atstage III and 22 cases at stage IV. The Harris score was 37.6 ± 2.0. The disease course was 1-6 years with an average of 2.6 years. In group B, 120 patients (167 hips) with non-traumatic ONFH included 67 males (94 hips) and 53 females (73 hips) with an average age of 52.6 years (range 41-67 years). According to Ficat classification, there were 56 cases (83 hips) at stage III and 64 cases (84 hips) at stage IV. The Harris score was 38.2±1.0. The disease course was 1.5-5.0 years with an average of 2.6 years. There were no significant differences in general data between two groups (P gt; 0.05). Results All 203 cases were followed up for 2 to 5 years (average 3.4 years). There were no significant differences in the operation time of single-hip, the blood loss, the blood transfusion between two groups (P gt; 0.05). Intraoperative fractures occurred in 4 hips (4.8%) of group A and 2 hips (1.2%) of group B, showing significant difference (P lt; 0.05). There were no significant differences (P gt; 0.05) in the incidence of dislocation [3 hips (3.6%) in group A and 1 hip (0.6%) in group B], continuous femoral pain [2 hips (2.4%) in group A and 1 hip (0.6%) in group B] and infection [1 hip (0.6%) in group B] between two groups. There were no significant differences (P gt; 0.05) in acetabular abduction, anteversion, femoral anteversion, and combined anteversion angles as well as the recovery rate of acetabular rotational center between two groups. The Harris scores of groups A and B after 2 years were 79.4 ± 2.1 and 84.2 ± 3.5.There was no significant difference between two groups (P gt; 0.05). The Harris score postoperation had significant differences compared with preoperation (P lt; 0.05). Conclusion Compared to the primary THA to non-traumatic ONFH, secondary THA to ONFH after failed internal fixation has no significant increase in operative difficulty, the postoperative hip function isgood, but the incidence of intraoperative fracture is higher.
ObjectiveTo explore the effectiveness of triangular stabilization system in the treatment of postoperative nonunion of femoral neck fracture.MethodsThe clinical data of 30 patients with postoperative nonunion of femoral neck fracture who met the selection criteria between December 2014 and December 2019 were retrospectively analyzed. There were 21 males and 9 females with an average age of 40.7 years (range, 15-65 years). The Pauwels angle at the time of injury was 51°-79°, with an average of 63.6°. According to the Pauwels classification, they were all type Ⅲ. The time from the first operation to this revision operation was 5-24 months, with an average of 9.7 months. The preoperative visual analogue scale (VAS) score was 4.2±1.3, the Harris score was 31.2±5.3, the neck-shaft angle was (116.3±7.9)°, and the lower limb shortening length was (1.73±0.53) cm. Triangular stabilization system, which was made of dynamic condylar screw and medial anatomical buttress plate, combined with the window bone grafting at the fracture site was used for bone nonunion revision. The postoperative lower limb shortening length, neck-shaft angle, fracture healing time, and complications were recorded; the Harris score was used to evaluate the hip joint function, and the VAS score was used to evaluate the pain improvement before and after operation.ResultsAll patients were followed up 12-60 months, with an average of 27.7 months. There was no clear sign of femoral head necrosis and collapse after operation; 1 patient developed infection at 4 months after operation, and the incision healed after debridement and removal of internal fixator. All patients achieved bone healing, and the healing time was 2.8-6.0 months, with an average of 3.9 months. At last follow-up, the lower limb shortening length was (0.30±0.53) cm, which was significantly corrected when compared with preoperative one (t=16.721, P=0.000); the neck-shaft angle was (133.9±5.7)°, which was significantly recovered when compared with preoperative one (t=−11.239, P=0.000). The VAS score was 0.7±0.9, the Harris score was 88.3±5.9, both of which were significantly improved when compared with preoperative scores (t=16.705, P=0.000; t=−40.138, P=0.000).ConclusionTriangular stabilization system combined with window bone grafting can provide a stable and balanced mechanical environment, promote fracture healing, and achieve satisfactory effectiveness in the treatment of postoperative nonunion of femoral neck fracture.
Objective To summarize the selection criteria and clinical application of surgical methods for hip fractures (femoral neck fracture and intertrochanteric fracture) in the elderly. Methods The related literature concerning the surgical methods for femoral neck fracture and intertrochanteric fracture in the elderly at home and abroad was extensively reviewed and summarized. Results Among the elderly patients with femoral neck fracture, the closed reduction and internal fixation or dynamic hip screw (DHS), and total hip arthroplasty are recommended for patients under 65 years old and 65–80 years old respectively and without special surgical contraindication; whereas hemiarthroplasty is recommended for patients with poor physical conditions. Among the patients with intertrochanteric fracture, DHS or the 3rd generation of Gamma nails is recommended for patients with stable fracture while the intramedullary fixation systems (e.g., proximal femoral nail anti-rotation, intertrochanteric antegrade nail) and the extramedullary fixation systems (e.g., proximal femoral locking compression plate and less invasive stabilization system) can be applied to the patients with unstable fracture according to the fracture type and bone conditions. Notably, hip arthroplasty is recommended for elderly patients with comminuted fracture. Conclusion The surgical method and internal fixator should be chosen according to the fracture type and bone condition in the elderly in order to improve the effectiveness and reduce the complication.
ObjectiveTo assess the effectiveness of pedicled iliac periosteal flap graft for treatment of avascular necrosis of the femoral head (ANFH) after femoral neck fracture in adolescents. MethodsBetween December 2006 and August 2011, 9 patients (9 hips) with ANFH after femoral neck fracture were treated with pedicled iliac periosteal flap graft. There were 6 males and 3 females with an average age of 14.7 years (range, 10-18 years). Fractures were caused by traffic accident injury (5 cases), falling injury from height (3 cases), and fall injury (1 case). The time from injury to internal fixation with Kirschner wires or cannulated screws was 3-16 days, and all fractures healed within 10 months after internal fixation. The interval between fracture fixation and ANFH was 10-42 months (mean, 24.4 months). According to Steinberg staging system, 1 hip was classified as stage Ⅲb, 2 hips as stage Ⅲc, 1 hip as stage IVa, 3 hips as stage IVb, and 2 hips as stage IVc. The Harris scores and Steinberg classification were compared between at pre- and post-operation to assess the outcomes clinically and radiologically. ResultsAll incisions healed by first intention. No complications of infection, deep venous thrombosis of lower limb, and pain and numbness of donor site were observed during or after operation. All patients were followed up 38-76 months (mean, 52 months). Joint pain was relieved; no leg length discrepancy was observed; the walking gait was improved and range of motion of hips was increased. The Harris score was significantly increased from 62.8±3.6 at pre-operation to 92.7±9.9 at last follow-up, showing significant difference (t=-12.244, P=0.000). The hip function was excellent in 5 hips, good in 3 hips, and poor in 1 hip, and the excellent and good rate was 88.89%. Post-operative radiological assessment demonstrated that only 1 hip (stage Ⅲb) had further collapse of the femoral head, the other hips had no incidence of deterioration. The radiological success rate was 88.89% (8/9). ConclusionThe pedicled iliac periosteal flap graft for ANFH after femoral neck fracture in adolescents can provide good osteogenesis and vascular reconstruction of the femoral head.
Objective To explore an ideal operative treatment to preserve the hi p joint for the old femoral neck fracture in young and middle-aged patients. Methods Between January 2002 and June 2006, 28 cases of old femoral neck fracture, 23 males and 5 females, aged 19-55 years old (37.6 on average), were reconstructed with free il iac grafts and fixed by dynamic hi p screws (DHS) and/or canulated screws. Multi ple vascular bundles derived from lateral circumflex femoral vascular were implanted in 19 cases. All the 28 cases were close fractures, with 17 of left hip and 11 of right hip. In terms of the fracture site, 4 cases were infer-head, 17 were per-neck and 7 were fundamental-form. The Harris score was 25-72 (49.6 onaverage) before operation. No callus formation was found on X-ray films in all cases; sclerosis and cyst were found in 4 cases and osteonecrosis of femoral head (ONFH) was confirmed by MRI. The duration between initial injury and surgery was 1-21 months (8.6 months on average). Results No deep infection was observed in all 28 cases, and paralysis of the lateral cutaneous nerve of the thigh was observed in 5 cases, and was better 6 months after operation with no special treatment. All 28 cases were followed up for 20-72 months (35.8 months on average). A total of 25 fractures healed within 4-8 months, with the heal ing rate of 89.3%; 3 fractures had nonunion and received artificial hip replacement. During the follow-up, 7 cases (25%) developed ONFH confirmed by MRI within 18 months, and 5 cases (17.9%) developed femoral head collapse. The Harris score was 27-100 (82.7 on average). Leg length discrepancy was not observed and the gait was fairly normal. Conclusion The femoral neck reconstruction procedure can restore the normal anatomy of femoral head and neck and the blood supply, so as to promote fracture heal ing as well as delay or avoid the artificial joint replacement. Therefore, it is an important treatment to preserve the hip joint for the old femoral neck fracture in young and middle-aged patients.
Objective To study the application and the curative effect of compressed screw and sartorius bone flap in treating femoral neck fractures in youth or middle age. Methods From February 1996 to December 2004, 86 patients with femoral neck fracture were treated by open reduction compressed screw and sartorius bone flap, aging from 21 to 49 years. Fracture was caused by traffic accident in 35 cases, fall from height in 27 cases and fall in 24 cases. Accoding to Garden classification, 23 cases were type Ⅱ, 25 cases were type Ⅲ, and 15 cases were type Ⅳ. We analyzed fracture healing and evaluate function by observation of the postoperative X-ray films. Results Of the 86 patients, 62 were followed up 6 months to 7 years (2 years and 5 months on average). According to Weijie’s criterion for nonunion and necrosis offemoral head, nonunion occurred in 4 cases; the healing rate of fracture was 93.5%. In healed patients, necrosis of femoral head occurred in 7 cases (11.3%) after 3 years. The results of hip joint function evaluation were excellent in 44 cases, good in 8 cases, fair in 6 cases and poor in 4 cases; and the excellent and good rate was 83.9%. Conclusion Compressed screw and sartorius bone flap was simple and effective for femoral neck fractures in youth or middle age.
ObjectiveTo summarize the research progress of medial buttress plate assisted fixation for femoral neck fractures in young adults.MethodsThe literature about buttress plate assisted fixation for femoral neck fractures in young adults was widely reviewed and analyzed. The design principle, background, biomechanical characteristics, and clinical results of buttress plate were summarized.ResultsMedial buttress plate assisted fixation is the latest treatment of femoral neck fractures in young adults, which can convert the shear force at the fracture sides into compression force and promote fracture healing. Medial buttress plate can improve the biomechanical stability of femoral neck fractures and reduce the maximum stress of fixation implants. In clinical, the medial buttress plate can maintain fracture reduction, reduce the incidences of nonunion and surgical failure, and improve hip joint function.ConclusionMedial buttress plate assisted fixation can achieve good effectiveness for femoral neck fractures in young adults. However, due to the preliminary application, its indications, fixation implants, and long-term effectiveness need to be further studied and improved.
Objective To compare the curative effect of dynamic hi p screw (DHS) combined with anti-rotation screw and cannulated screw in treating patients with Pauwels type II or III femoral neck fracture and to provide the basis for the choice of surgical procedure. Methods Between March 2008 and September 2009, 51 patients with fresh Pauwels type II or III femoral neck fracture were treated with DHS combined with anti-rotation screw (DHS group) and three cannulated screws (cannulated screw group). The DHS group included 23 patients, 13 males and 10 females, aging 27-59 years (mean, 43.2 years); fracture was caused by fall ing in 1 case, by traffic accident in 17, by fall ing from height in 5 with a mean time of 27 hoursfrom injury to hospital ization (range, 12-70 hours); and 23 fractures included 9 Pauwels type II and 14 Pauwels type III femoral neck fracture. The cannulated screw group included 28 patients, 12 males and 16 females, aging 20-60 years (mean, 40.7 years); fracture was caused by fall ing in 1 case, by traffic accident in 22, by fall ing from height in 5 with a mean time of 25 hours from injury to hospital ization (range, 9-38 hours); and 28 fractures included 12 Pauwels type II and 16 Pauwels type III femoral neck fracture. There was no significant difference in the basel ine characteristics between 2 groups (P gt; 0.05). Results The incision heal ing of both groups by first intention was achieved. There were significant differences in operation time, incision size, operation blood loss, the cases of blood transfusion, the amount of blood transfusion, C reaction protein level on the 2nd postoperative day, and hospital ization days between 2 groups (P lt; 0.05). In DHS group, anatomic reduction was observed in 20 cases (86.96%) and satisfactory reduction in 3 cases (13.04%), while in cannulated screw group, anatomic reduction was observed in 25 cases (89.29%) and satisfactory reduction in 3 cases (10.71%) ; there was no significant difference (χ2=0.660, P=1.000). The patients were followed up 12-30 months with an average of 14.8 months. There was no significant difference (P gt; 0.05) in the rate of nonunion (10.71% vs. 0), the implant failure (3.57% vs. 0), and avascular necrosis of the femoral head (10.71% vs. 0) between the DHS group and the cannulated screw group. The union time was (94.5 ± 2.0) days in the DHS group and (106.0 ± 33.5) days in the cannulated screw group, showing no significant difference (t=—1.641, P=0.107). The re-opereation rates and the overall success rates were 25% and 75% in the cannulated group and were 0 and 100% in the DHS group, showing significant differences (χ2=6.650, P=0.012). At last follow-up, there was no significant difference in Harris hip score and visualanalogue scale (VAS) score between DHS group and cannulated screw group (P gt; 0.05). Conclusion The optimal treatment of young adults Pauwels type II or III femoral neck fracture is DHS combined with anti-rotation screw with an high overall success and less compl ications.
ObjectiveTo explore the changes of bone and risk of micro-fracture in femoral head after removal of cannulated screws following femoral neck fracture healing under the impact force of daily stress.MethodsA total of 42 specimens of normal hip joint were collected from 21 adult fresh cadaveric pelvic specimens. Wiberg central-edge (CE) angle, bone mineral density, diameter of femoral head, neck-shaft angle, and anteversion angle of femoral neck were measured. Then, the 3 cannulated screws were implanted according to the AO recommended method and removed to simulate the complete anatomical union of femoral neck fracture. The morphology of screw canal in the femoral head was observed by CT. Finally, the specimens were immobilized vertically within the impact device in an upside-down manner, and the femoral heads were impacted vertically. Every specimen was impacted at 200, 600, and 1 980 N for 20 times with the impacting device. After impact, every specimen was scanned by CT to observe the morphology changes of screw canal in the femoral head. Micro-fractures in the femoral head could be confirmed when there was change in the morphology of screw canal, and statistical software was used to analyze the risk factors associated with micro-fractures.ResultsAfter impact at 200 and 600 N, CT showed that the morphology of screw canal of all specimens did not change significantly compared with the original. After impact at 1 980 N, there were protrusion and narrowing in the screw canal of the 22 femoral head specimens (11 pelvic specimens), showing obvious changes compared with the original screw canal, indicating that there were micro-fractures in the femoral head. The incidence of micro-fracture was 52.38% (11/21). logistic regression results showed that there was correlation between micro-fracture and bone mineral density (P= 0.039), but no correlation was found with CE angle, diameter of femoral head, neck-shaft angle, and anteversion angle (P>0.05).ConclusionThe micro-fractures in the femoral head may occur when the femoral head is impacted by daily activities after removal of cannulated screws for femoral neck fractures, and such micro-fractures are associated with decreased bone density of the femoral head.