Biomechanical analysis on Vancouver BI periprosthetic femoral fractures fixed by a customized anatomical plate system / 中国组织工程研究

BACKGROUND:At present,the use of a locking bone plate combined with steel wire or steel cable for the treatment of periprosthetic femoral fracture often adopts monocortical fixation,which is not stable and the proximal end of the bone cannot be achieved anatomically fitted by plate.The customized anatomical plate system can effectively solve this problem. OBJECTIVE:To explore the biomechanical strength of a customized anatomical plate system in fixation of Vancouver BI periprosthetic femoral fracture. METHODS:CT thin layer scanning data of normal femurs of 1 006 cases were selected and input into the MIMICS 21.0 software to establish the three-dimensional reconstruction model of the femur,which was set as the three-dimensional reconstruction group.56 complete human femoral specimens were selected as the femoral specimen group.The measured results of the two groups for femoral anatomical appearance were compared.If there was no significant difference between the two groups,the approximate appearance of a customized anatomical plate system was designed based on the measurement results in MIMICS 21.0 software and NX11.0 software.The customized anatomical plate system was designed and prepared according to the above measurement results.Eight pairs of frozen human femurs were selected to make Vancouver BI periprosthetic femoral fracture,which of the left were thin layer scanned by dual-source CT to obtain data.The data were transferred to determine the customized anatomical plate system model by the above design software.Eight sets of customized anatomical plate systems were ultimately produced,relying on the instrument company.The eight pairs of models were numbered 1-8.The left side was fixed with the customized anatomical plate system(customized anatomical plate system group);the right side was fixed with a metal locking plate system-large locking plate(claw plate group).L1-L4 and R1-R4 were subjected to vertical short-cycle loading test and vertical loading test.L5-L8 and R5-R8 were subjected to horizontal short-cycle loading test and four-point bending test.The vertical loading test and four-point bending test were used to collect bending load,bending displacement,and bending strain.Two short cycle loading tests were used to collect strain displacement to compare the maximum load,maximum displacement,bending stiffness,and short-period displacement resistance of the two kinds of bone plates. RESULTS AND CONCLUSION:(1)There were no significant differences in all indexes between the three-dimensional reconstruction group and the femoral specimen group(P>0.05).Individual customized anatomical plate system was designed based on the measurement results combined with digital software.(2)In the vertical loading test,the maximum load was higher(P=0.015),the maximum bending displacement was smaller(P=0.014),and the bending stiffness was higher(P=0.005)in the customized anatomical plate system group compared with the claw plate group.(3)In the four-point bending test,the maximum load was higher(P=0.023),the bending stiffness was higher(P=0.005),and the maximum bending displacement was not significant(P=0.216>0.05)in the customized anatomical plate system group compared with the claw plate group.(4)In the vertical short-cycle loading test,the average level of bending displacement in the customized anatomical plate system group(0.23±0.10 mm)was significantly lower than that in the claw plate group(0.44±0.02 mm)(P<0.05).(5)There was no significant difference in the average level of bending displacement between the two groups in the horizontal short cycle loading test(P>0.05).(6)It is concluded that the customized anatomical plate system has personalized anatomical characteristics,and the fixation of Vancouver BI periprosthetic femoral fracture is more stable,which has certain significance for clinical treatment.

Risk factors and prediction model for periprosthetic femoral fracture after total knee arthroplasty in the elderly / 局解手术学杂志

Objective To investigate the risk factors of periprosthetic femoral fracture(PFF)after total knee arthroplasty(TKA)in the elderly and to construct a predictive model for the prevention of PFF after clinical operation.Methods The clinical data of 537 elderly patients who underwent TKA in the orthopedic department of the First Affiliated Hospital of Air Medical University from October 2016 to October 2021 were retrospectively analyzed.The occurrence of PFF during the follow-up period was statistically analyzed and the clinical data were collected.Binary Logistic regression was used to analyze the risk factors of PFF after TKA in the elderly,and a predictive model of PFF after TKA in the elderly was constructed based on the risk factors.Receiver operating characteristic(ROC)curve and Hosmer-Lemeshow(H-L)were used to test the discrimination and calibration of prediction model.Results The patients were followed up for 12 to 72 months after discharge,with a median time of 47 months.During the follow-up period,31 patients(5.77%)developed PFF.Age,osteoporosis,Parkinson's disease and anterior femoral notch(AFN)were the risk factors for PFF after TKA in the elderly(P<0.05),and cross fixation of prosthesis and bone cement fixation were the protective factors(P<0.05).The results of H-L test showed that the risk prediction model of PFF after TKA in the elderly had good calibration(P>0.05).ROC curve analysis showed that the risk prediction model of PFF after TKA in the elderly has high discrimination(area under the curve was 0.858,95%CI:0.826 to 0.887),the sensitivity was 83.87%,the specificity was 88.34%.Conclusion The risk of PFF after TKA in the elderly is high,and prevention should be carried out according to the high risk factors.The prediction model constructed based on the high risk factors has good prediction efficiency.

Radiographic Characteristics of the Femoral Nutrient Artery Canals in Total Hip Arthroplasty using Cementless Femoral Stem

@#Introduction: Accurate diagnosis of undisplaced periprosthetic femoral fracture (PFF) after hip arthroplasty is crucial, as overlooked PFF may affect its treatment and prognosis. The undisplaced PFF is often difficult to distinguish from radiolucent lines of nutrient artery canal (NAC) of the femur present on post-operative radiographs. We aimed to identify the radiographic features of NAC to distinguish them from PFFs. Materials and methods: In this retrospective radiological study, a total of 242 cases in 215 patients with hip arthroplasty were analysed using pre-operative and postoperative anteroposterior (AP) and translateral (TL) radiographs. Interobserver agreement of the measurements was assessed by two independent experienced orthopaedic surgeons. The kappa value ranged from 0.83 to 0.87, indicating strong agreement according to the Landis and Koch criteria. Results: The NACs were found pre-operatively in 94 (39.8%) cases on AP views and in 122 cases (50.4%) on TL views. The radiolucent lines were observed post-operatively in 42 (17.4%) on AP views and 122 (50.4%) on the TL views. three cases (1.2%) had a fracture around the stem that were detected on radiographs. One case with PFF presented simultaneously with NAC on the immediate post-operative radiographs. All patients were treated by conservative measures, and the radiolucent lines did not appear on followup radiographs. Conclusion: It is not easy to differentiate undisplaced PFFs that can occur after hip arthroplasty operation from NACs. However, accurate diagnosis is possible through careful observation and comparison of pre-operative and postoperative radiologic images

The Clinical and Radiological Results of Vancouver Type B1 and C Periprosthetic Fractures

PURPOSE: The purpose of this study is to evaluate the clinical and radiologic results of plate fixation in the Vancouver B1 and C periprosthetic femoral fracture (PFF). MATERIALS AND METHODS: Twenty patients who had sustained a Vancouver type B1 and C periprosthetic fracture after hip arthroplasty (years 2002-2012) were identified. The mean age was 66.0 years (range, 43-85 years) and the mean follow-up duration of the group was 38 months (range, 12-102 months). The dynamic compression plate (DCP) group included 12 patients and the locking compression plate (LCP) group included eight patients. Harris hip score (HHS) and walking ability, knee joint range of motion (ROM) were compared before injury and last follow-up. Fracture union rate and period were compared. RESULTS: The mean HHS score was 90.7 (64-96). There was no statistical difference between the two groups. At the last follow-up, knee joint ROM was 103.3degrees (105degrees-140degrees) in the DCP group and 118.4degrees (110degrees-140degrees) in the LCP group, showing good results in the LCP group (p=0.043). No significant difference in the fracture union rate and union periods was observed between the two groups. CONCLUSION: A better result for the postoperative knee flexion exercise capacity was observed in the LCP group. Use of LCP plate fixation is a good option in management of Vancouver classification B1 and C PFF.

Outcomes of Surgical Treatment of Periprosthetic Femoral Fractures in Cementless Hip Arthroplasty / 대한고관절학회지

PURPOSE: We aimed to evaluate the results of surgical treatment of periprosthetic femoral fractures in cementless total hip arthroplasty (THA). MATERIALS AND METHODS: From June 2002 to May 2012, 40 patients who could be followed-up for more than 1 year after surgery were enrolled in this study. The mean duration of follow-up was 28.5 months (range, 15-97 months) and the average age at the time of surgery was 71.5 years (range, 38-89 years). The fracture types were determined by using the Vancouver classification. Among intraoperative fractures, there were type A in 3 hips, type B2 in 2 hips and type B3 in one. Among postoperative fractures, type AG was present in 5 hips, type AL in 2 hips, type B1 in 15 hips, type B2 in 6 hips, type B3 in 3 hips, and type C in 3 hips. Evaluation of the results was based on bony union, stability of the prosthesis, postoperative complications, and Harris hip score at the final follow-up. RESULTS: Bony union was achieved in all but one case and the average time for bony union was 21 weeks. The mean Harris hip score was 86 at the final follow-up. Clinical results were above good in 34 of 40 hips (85.0%). Stem loosening occurred in one patient with a type B1 fracture treated with open reduction and plate fixation. Nonunion was observed in 1 patient with an AG type fracture. CONCLUSION: Open reduction and fixation using a plate with a screw and cerclage wiring provided good results for periprosthetic fractures in patients who had a stable femoral stem without bone defects. Revision surgery with a cementless long stem should be considered in patients with an unstable stem or suspected stability in B1 type of THA using a proximal fixation type.

Minimally Invasive Plate Osteosynthesis for Periprosthetic Distal Femoral Fractures after Total Knee Arthroplasty

PURPOSE: To evaluate the outcomes of the treatment of distal femoral fractures using minimally invasive plate osteosynthesis following total knee arthroplasty (TKA). MATERIALS AND METHODS: From July 2008 to October 2011, 14 patients were treated with minimally invasive plate osteosynthesis for periprosthetic fractures following TKA. The mean duration of follow-up was 19.2 months and the mean age was 69.7 years. Lewis and Rorabeck classification was used to categorize the type of fracture. Pre- and postoperative range of motion, femorotibial angle, and Knee society score, time to bony union, and complications were evaluated. RESULTS: The mean range of motion was 108.4 degrees preoperatively and 107.3 degrees postoperatively. No significant difference was observed in the pre- and postoperative mean range of motion. The average time to bony union was 3.9 months. The knee society score was 82.6 points preoperatively and 78.9 points postoperatively. The mean femorotibial angle was changed from 6.1 degrees valgus postoperatively to 4.6 degrees valgus postoperatively. There was no complication during the follow-up. CONCLUSIONS: Minimally invasive plate fixation for distal femur fractures after TKA showed good results. Minimally invasive plate osteosynthesis is a recommendable treatment method for periprosthetic fractures.

Repeated Periprosthethic Femoral Fracture in a Below Knee Amputee with Ipsilateral Cementless Total Hip Arthroplasty: A Case Report / 대한고관절학회지

Total hip arthroplasty (THA) is rarely performed in below-knee amputee patients. To the best of the authors' knowledge, periprosthetic femoral fracture in such patients has not been previously reported. Such devastating complication can occur even with minor trauma. To prevent occurrence of such events, there may be several important factors to be considered in performance of THA surgery in below-knee amputee patients and during the course of rehabilitation. In this report, we describe a case involving a below-knee amputee patient who experienced multiple periprosthetic femoral fractures after THA.

Periprosthetic Femoral Fractures after Hip Arthroplasty

Periprosthetic femoral fractures are increasing. In a periprosthetic femoral fracture, treatment is difficult and complications are common. The result of total hip arthroplasty becomes poor. The study sought to determine the cause and risk factors of periprosthetic femoral fracture after total hip arthroplasty, and discusses treatment according to the guidelines of the Vancouver classification.

Treatment of Periprosthetic Femoral Fractures after Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: To determine results of treatment according to the guidelines of the Vancouver classification in periprosthetic femoral fractures after total hip arthroplasty. MATERIALS AND METHODS: Among 44 cases of periproshtetic femoral fractures after hip arthroplasty treated between Aug. 1991 and Feb. 2008, thirty-two cases with minimum follow-up greater than one year were included. Outcomes were evaluated using the Beals and Tower's critieria. RESULTS: Outcomes were excellent in 27 cases, and poor in 5 cases. Four of 5 cases with poor result were due to non-union. Three cases were treated with internal fixation and 1 case was treated with a conservative method. One case with a poor result was due to loosening of the cemented stem of a Vancouver type B1 fracture. Loosening of the stem after mid to long term follow up occurred in an additional 4 cases (3 cases with a cemented stem in a type B1 fracture, 1 case with a cemented stem of a type C fracture). Loosened stems were revised with a long revision stem. CONCLUSION: For type B1 periprosthetic fractures around a cementless stem, and for type B2, type B3 periprosthetic fractures, treatment according to the guidelines of the Vancouver classification showed excellent results. However, type B1 periprosthetic fractures around a cemented stem showed poor results with non-union or stem loosening. Hence, more rigid fixation using a bone graft or revision of the stem is needed. In type C periprosthetic fractures in osteoporotic patients, closer attentions is needed to avoid complications.

Treatment of Vancouver B2 and B3 Periprosthetic Femoral Fractures

Purpose: To evaluate respectively the clinical results after femoral stem exchange or retention in the treatment of Vancouver B2, B3 periprosthetic femoral fractures. Materials and Methods: Nineteen cases of Vancouver B2 fractures and 8 cases of B3 fractures that were treated surgically between January 1992 to October 2004 were reviewed. There were 15 retained stems (group A) and 12 exchanged stems (group B). Firm fixation of a fracture and stem with a plate, screw and cable was performed in both groups. The HHS and criteria of Beals and Tower was used for the clinical and radiological evaluation. Results: The mean HHS was 84 in group A and 85 in group B. Unsatisfactory (<80 HHS) results were obtained in 2 cases from each group. The radiological results were excellent in both groups with the exception of one case of femoral stem loosening in group A and one case of non-union in group B. The complications encountered were 1 case of femoral stem loosening, 1 case of non-union, 1 case of a superficial infection, 1 case of dislocation, and 1 case of cup loosening. Conclusion: Stable fixation of the fracture and stem with a sufficient bone graft in the treatment of Vancouver B2, B3 periprosthetic femoral fractures can produce favorable clinical results regardless of the level of femoral exchange.

Treatment of Periprosthetic Femoral Fractureaccording to the Vancouver Classification / 대한정형외과학회잡지

PURPOSE: To determine the treatment results according to the guideline of the Vancouver classification in periprosthetic femoral fractures. MATERIALS AND METHODS: Thirty-five periprosthetic femoral fractures treated between May 1981 and February 2003 were assessed. The mean age of the patients was 56 years (30-83 years). The outcomes were estimated according to the Beals and Tower's criteria. RESULTS: The overall incidence of postoperative periprosthetic femoral fracture was 0.91%. The frequency of the fracture types in decreasing order was B1, B2, B3, C, AG and AL. The treatment outcomes according to the Vancouver guidelines were excellent in 27 hips, good in 5 hips and poor in 3 hips. Suspicious risk factors of periprosthetic fractures were found in 6 hips (osteoporosis in 4 hips, osteolysis in 1 hip and loosening of femoral stem in 1 hip). Complications related to the treatment included a bony defect in 1 hip and an infection with non-union in 1 hip. The complications related to treatment for an implant were loosening in 2 hips and subsidence of stem in 1 hip. CONCLUSION: In order to obtain favorable results, in addition to following the Vancouver treatment guideline, consideration should be made to the basic principles such as the stability of the fractures, the stability of the implant and restoration of the bone stock.

Treatment of Periprosthetic Femoral Fractures with Cable Plate

PURPOSE: To evaluate the results of Cable plate fixation for the treatment of periprosthetic femoral fracture after hip arthroplasty. MATERIALS AND METHODS: We reviewed 10 cases of periprosthetic femoral fractures after hip arthroplasty between Nov. 2002 and May 2004. The mean follow up periods were 20 months. The fractures were classified according to Vancouver classification. Seven cases of type B1, one case of type B3 and two cases of type C were treated with open reduction and internal fixation with Cable plate. Evaluation of results was based on mean union time, postoperative complications and Harris hip score. RESULTS: The mean time for bony union was 4.8 months in type B1, 6 months in type B3 and 8 months in type C fracture. As for complications, there were refracture, metal breakage and nonunion. The postoperative mean Harris hip score was 91.5 points for type B1, 85 points for type B3 and 72.5 points for type C fracure. CONCLUSION: Cable plate can be useful for treatment of periprosthetic femoral fractures after hip arthroplasty, but the selection of treatment methods should be cautiously made according to the type of fracture and status of patients.