3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty and revision surgery / 中华骨科杂志

Objective:To investigate the clinical efficacy of 3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty (TKA) and knee revision surgery.Methods:A total of 7 patients (7 knees) with TKA or knee revision who were admitted to the Department of Orthopaedics of the Second Affiliated Hospital of Zhejiang University School of Medicine with large bone defects from July 2018 to December 2023 were retrospectively analyzed, including 4 patients with TKA and 3 patients with knee revision. There were 3 males and 4 females, aged 58.7±7.6 years (range, 54-68 years), 3 patients with left knee and 4 patients with right knee. All the patients had bone defects in the knee joint (AORI type III), 2 cases had bone defects only in the femur, 4 cases had bone defects only in the tibia, and 1 case had bone defects in both the tibia and femur, which were treated with personalized reconstruction using 3D printing. Hip-knee-ankle angles, American Knee Society score (KSS) before and after surgery were compared, and postoperative complications were observed.Results:All patients successfully completed the operation, and the operation time was 189.3±35.5 min (range, 125-240 min). Complex TKA was performed in 4 cases with surgical times of 175, 195, 210, and 240 min, and revision surgery was performed in 3 cases with surgical times of 125, 180, and 200 min, respectively. Intraoperative blood loss was 114±24.4 ml (range, 100-150 ml). Five cases used 3D printed metal augment, and two used 3D printed one-piece tibial components. All patients were followed up for 2, 2, 5, 6, 7, 20, 57 months, respectively. The KSS of the five patients at 3 months postoperatively were 56, 61, 66, 56, and 56 points, respectively, greater than the preoperative scores of 35, 44, 36, 27, and 41 points. The KSS functional scores of the five patients at 3 months postoperatively were 45, 45, 45, 30, and 45 points, respectively, which were greater than the preoperative scores of 30, 30, 15, 20, and 20 points. The hip-knee-ankle angle was 181.8°±3.4° (range, 177.9° to 188.0°) at the final follow-up and 175.8°±12.4° (range, 153.3° to 192.1°) before surgery, with no significant difference ( t=-1.230, P=0.242). At the final follow-up, the 3D printed component was well integrated with the bone surface, the prosthesis was securely positioned, and the force lines of the lower limbs were normal. There were no postoperative complications such as poor wound healing, infection, fat liquefaction, nerve injury, deep vein thrombosis of lower limbs, knee joint stiffness, periprosthesis infection and loosening. Conclusion:Using 3D printed metal augment or tibial prosthesis to reconstruct the huge bone defect in TKA and revision has a satisfactory early clinical effect, satisfactory joint function and good surgical safety.

Manipulation of isocitrate dehydrogenase genes affects the anti-autolytic ability of lager yeast / 生物工程学报

Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast autolysis showed that the citric acid cycle-related genes had a great influence on yeast autolysis. To explore the contribution of isocitrate dehydrogenase genes in autolysis, the IDP1 and IDP2 genes were destroyed or overexpressed in typical lager yeast Pilsner. The destruction of IDP1 gene improved the anti-autolytic ability of yeast, and the anti-autolytic index after 96 h autolysis was 8.40, 1.5 times higher than that of the original strain. The destruction of IDP1 gene increased the supply of nicotinamide adenine dinucleotide phosphate (NADPH) and the NADPH/NADP+ ratio was 1.94. After fermentation, intracellular ATP level was 1.8 times higher than that of the original strain, while reactive oxygen species (ROS) was reduced by 10%. The destruction of IDP2 gene resulted in rapid autolysis and a decrease in the supply of NADPH. Anti-autolytic index after 96 h autolysis was 4.03 and the NADPH/NADP+ ratio was 0.89. After fermentation, intracellular ATP level was reduced by 8% compared with original strain, ROS was 1.3 times higher than that of the original strain. The results may help understand the regulation mechanism of citric acid cycle-related genes on yeast autolysis and provide a basis for the selection of excellent yeast with controllable anti-autolytic performance.

Short-term clinical outcomes of outpatient total hip arthroplasty / 中华骨科杂志

Objective:To investigate the safety, economic effect, and short-term clinical efficacy of ambulatory total hip arthroplasty (THA) in the treatment of hip osteopathy within.Methods:This study retrospectively reviewed patients who underwent 48-hour outpatient THA and conventional primary THA from July 2020 to July 2021. Gender, age, body mass index (BMI), clinical diagnosis, place of resident, length of hospital stay, duration of the surgery, hemoglobin, albumin, C-reactive protein (CRP) and D-dimer before and 1 day after surgery, the visual analogue scale (VAS) was obtained postoperative day 2, hip joint modified Harris score before and 1 month after surgery, readmission and reoperation within 1 month after operation as the data of evaluations were extracted and compared in this study.Results:A totally of 150 cases were involved in this study, which including 75 cases with 48-hour outpatient primary THA and 75 cases with conventional primary THA. There was no significant difference between the two groups in terms of age, sex, BMI, education level, preoperative diagnosis, and preoperative Harris score ( P>0.05), but a significant difference was found in term of residence (χ 2=6.29, P=0.043), that the patients in the outpatient group were all from Zhejiang Province and 48% (36/75) of them were from Hangzhou City. While, in the conventional group, 6 patients were from other provinces. The length of stay was 2.13±0.52 days and operation time was 59.73±18.91 minutes in the outpatient group, which were both shorter than those (6.71±1.44 days and 66.91±22.40 min) in the conventional group ( t=25.91, P<0.001 for the length of hospital stay; t=2.12, P=0.036 for operation time). Compared with the conventional group, outpatient group saved the average hospital cost (4.60±0.44 vs. 5.20±0.72 ten thousand yuan, t=6.16, P<0.001). The VAS on the second day after surgery 3.45±0.75 was higher in the outpatient group than in the conventional group (3.45±0.75 vs. 3.16±0.94 points, t=2.09, P=0.039). The modified Harris score was without statistical significance ( t=0.42, P=0.677) 1 month after surgery in both groups. 75 patients in the outpatient group, 7 patients delayed discharge (were not discharge within 48 hours), and the rate of delayed discharge was 9.3%. Reasons for delayed discharge included poor pain control in two cases, one case had postoperative nausea and vomiting, one case had failed to meet rehabilitation standards, hypotension in one case, the intraoperative infection in one case and postoperative fever within 48 hours in one case. Conclusion:Outpatient THA can reduce the length of hospital stay, operative time and total cost of hospitalization. It has similar safety and early clinical efficacy as conventional THA. However, a small proportion of patients would delay discharge.

Surgical treatments for Vancouver type B1 periprosthetic femoral fractures / 中华骨科杂志

Objective To investigate the outcomes of the treatments for the patients with Vancouver type B 1 periprosthetic femur fractures.Methods Seventeen patients with periprosthetic femoral fractures (5 males and 12 females;average age,70.4 years,range from 37 to 86 years) who underwent revision arthroplasty or open reduction and internal fixation between December 2006 and June 2016 were retrospectively reviewed.Periprosthetic femoral fractures occurred at the mean time of 65.1 months after arthroplasty.Twelve patients underwent open reduction and internal fixation and five cases underwent total hip or stem revision with Solution from Depuy,Wagner from Zimmer,Echelon from Smith & Nephew or Secur-Fit Max from Stryker due to primary bone loss,acetabular component wear or long-time prosthesis use respectively.Data were collected at 1,3,6 and 12 months and then each year postoperatively.All patients were followed up,and the results of X-ray,postoperative Harris hip score,stability of prosthesis and complications were also evaluated.Results A total of 5 patients underwent revision arthroplasty,and 12 patients underwent open reduction and internal fixation.The mean follow-up duration was 56 months (range from 7 to 120 months).Total blood loss in the open reduction and internal fixation group and in revision group was 385± 129 ml and 531± 113 ml respectively.The operation duration in the open reduction and internal fixation group was 72±36 min while it was 126±48 min in the revision group.The postoperative Harris hip score in the open reduction and internal fixation group was significantly increased compared with preoperative Harris hip score (68.8±18.4 vs.46.2±9.6),as well as in the revision group (75.0±8.9 vs.57.4±13.0).For the incidence of complications,in the open reduction and internal fixation group,one patient suffer with delayed fracture union,one patient complained about persistent pain and one suffered a secondary fracture,while in the revision group one suffered from blood loss and one with long-term pain.Conclusion Open reduction and internal fixation is an optimal intervention for Vancouver B 1 fracture,and revision arthroplasty can be considered as a safe alternative in patients with primary bone loss,implant of short survival time,severe liner wear or long-term prosthesis use.

Application of jumbo cup in acetabular revisions for patients with massive acetabular bone deficiency / 中华骨科杂志

Objective To investigate the effects of the jumbo cup in acetabular revision for patients with massive acetabular bone deficiency.Methods We retrospectively studies 48 patients (49 hips) who underwent jumbo cup revisions between 2006 and 2015 (19 men and 29 women;average age:62± 12 years).The acetabular bone defects were classified according to Paprosky classification (Paprosky Ⅱ 27 hips,Paprosky ⅢA 18 hips,Paprosky ⅢB 4 hips).Radiological assessments were conduced to evaluate the acetabular prosthesis loosening,dislocation and infection.The reasons for revisions were mechanical loosening in 41 cases,and infections in another 8 cases with cement spacer putted by last surgery.Results The operation duration and blood loss was 110 min (85-160 min) and 315 ml (270-455 ml) respectively.After an average follow-up of 6.8 years (1-11 years),Harris hip score was increased from 47.6±7.1 preoperatively to 82.4± 6.2 postoperatively.Osseointegration occurred in the acetabular components at 6 months postoperatively.Radiograph analysis showed satisfied position of acetabular cup without complications such as damages of vessels or nerves.The successful rate of jumbo cup revisions was 89.8％±4.4％.However,two in Paprosky ⅢA failures for periprosthetic infection occurred and two in Paprosky ⅢA,one in Paprosky ⅢA and the other in Paprosky ⅢB for acetabular component loosening.One patient in Paprosky ⅢB had weight-bearing pain and relieve slightly after conservative treatment.The radiologic study showed that there was no relationship between failure rate and acetabular abduction angle (r=0.06,P=0.53),rotation center migration in vertical direction (r=0.11,P=0.14) and horizontal direction (r=0.04,P=0.89).Conclusion The mid-term results show that using jumbo cup in revising acetabular failure with massive bone deficiency are optimal,which can be achieved by simplified operation procedures,reduction in the need of bone graft and promotion in acetabulum osseointegration.However,higher failure rate may occur in Paprosky ⅢB patients.

The treatment of patellofemoral arthroplasty for isolated patellofemoral osteoarthritis / 中华骨科杂志

Objective To explore the effect and factors of patellofemoral arthroplasty (PFA) for isolated patellofemoral osteoarthritis.Methods Data of 18 patients (3 males,15 females) with isolated patellofemoral osteoarthritis underwent PFA from March 2006 to December 2014 were retrospectively analyzed.There were 3 males and 15 females with a mean age of 54 years (range,46-74 years).It was strict to grasp the surgical indications according to the clinical symptoms,signs and imaging data preoperatively.11 patients were operated with AVON patellofemoral prosthesis (Stryker Inc.) and the other 7 patients were operated with the Gender Solutions patellofemoral prosthesis (Zimmer Inc.).Active and passive functional rehabilitation exercise was encouraged at the early stage after operation.Visual analogue scale (VAS) was 5.33±0.99 (range,4-7) and hospital for special surgery knee score (HSS) was 53.28±5.71 (range,44-63) before operation.Results The mean duration of follow-up was 63.98 months (range,6-104 months).VAS after operation for 1 and 3 months were 1.17±0.79 (range,0-3) and 0.72±0.67 (range,0-2),and the pain was almost relieved after 9 months.HSS after operation for 1,3,9 months were 70.06±6.33 (range,61-80),86.06±5.12 (range,77-95) and 91.39±4.83 (range,82-97).HSS score of the latest follow-up was 92.06±4.05 (range,84-97),which was improved obviously from the preoperative ones.The excellent and good rate was 100％ (excellent 15 cases,good 3 cases).The satisfactory rate was 94.4％ (17/18).Only one case got slightly knee pain when walking up and down the stairs after 2 years,and the pain was relieved after being administered with NSAIDs and rest.No incision infection,rupture,prosthesis supported bone fracture,prosthesis loosening and other complication was occurred during the follow-up period in the other patients.Conclusion The clinical outcomes of PFA are strictly related to surgical indications,implant design and appropriate surgical technique.Therefore,based on the appropriate PFA implants,strict surgical indications,appropriate patients,excellent operation skills and actively functional rehabilitation exercise,PFA could treat the isolated patellofemoral osteoarthritis effectively.

Acetabular revision using an anti-protrusion cage in patients with periprosthetic acetabular bone loss / 中华骨科杂志

Objective To investigate the risk factors related to the survival time of anti-protrusion cage in acetabular revision.Methods Data of 40 patients who had received acetabular revision using antiprotrusion cages between January 2002 and June 2010 were retrospectively analyzed.There were 16 males and 24 females,aged from 22 to 77 years (average,60.3 years).All patients were followed up for 12 to 82 months (average,39.2 months).According to the AAOS classification,there were 29 cases of type C and 11 cases of type D； while according to the Paprosky classification,there were 29 cases of type ⅢA and 11 cases of type Ⅲ B.The multiple regression analysis was utilized to investigate the relationships between different factors and anti-protrusion cage failure.The corresponding factors included gender,age,bone loss classification,superior or lateral migration of acetabular center of rotation,abduction angle,fixation manners (simple flange fixation or flange fixation plus transacetabular screw fixation),bone grafting techniques and cup type.Results At final follow-up,the average Harris score was 74.5±15.4.Two patients received rerevision due to prosthetic loosening.Obvious radiological loosening of prosthesis combined with pain was found in 2 cases.The statistical analysis indicated that superior migration of acetabular center of rotation,abduction angle and fixation manners were correlated with cup failure,especially when the superior migration was more than 8.5 mm or the abduction angle was larger than 53.5°.Flange fixation plus transacetabular screw fixation could reduce risk of cup failure.Conclusion There is a higher cup failure risk in acetabular revision using an anti-protrusion cage for patients with serious bone defect.However,implanting cup at the level of the true acetabulum as far as possible,decreasing abduction angle properly and using flange fixation plus transacetabular screw fixation can reduce cup failure risk.

Comparison of anterior knee pain after total knee arthroplasty using Genesis Ⅱ and PFC knee prostheses / 中华骨科杂志

Objective To explore relationship between anterior knee pain after total knee arthroplasty and patella resurfacing and prosthesis design,and to evaluate which femoral prosthesis is more friendly with patella:Genesis Ⅱ or PFC knee prostheses.Methods Data of 145 patients (145 knees) who had undergone primary total knee arthroplasty for treating osteoarthritis were retrospectively analyzed.Posterior-cruciate-substituting total knee prostheses were used in all patients.Among 74 patients who had undergone patella resurfacing,Genesis Ⅱ knee prosthesis was used in 32 patients and PFC knee prosthesis in 42 patients.Among 71 patients who had not undergone patella resurfacing,Genesis Ⅱ knee prosthesis was used in 38 patients and PFC knee prosthesis in 33 patients.The Hospital for Special Surgery(HSS) score,patella score,patellar function score,range of motion of knee,anterior knee pain scale,and patient satisfaction were used to evaluate clinical outcomes.At the same time,the imaging results were evaluated by X-rays.Results 144 patients were successfully followed up for 21 to 43 months (average,33 months).There was no significant difference in incidence of anterior knee pain between the group with patella resurfacing and the group without patella resurfacing,while a significant difference was found between patients receiving Genesis Ⅱ knee prosthesis and those receiving PFC knee prosthesis.Four patients who had undergone total knee arthroplasty using PFC prosthesis underwent reoperation.There were no significant differences in postoperative HSS score,range of motion of knee and patient satisfaction between the Genesis Ⅱ group and the PFC group,while there were significant differences in patella score and patellar function score between them.Conclusion Postoperative anterior knee pain was related to the prosthesis design,rather than to the patella resurfacing.Genesis Ⅱ knee prosthesis was more friendly with patella than PFC knee prosthesis.

Controllable synthesis of different size hydroxyapatite nanoparticles and their biological effects on osteoblast-like cells / 中华骨科杂志

ObjectiveTo investigate the size effect of hydroxyapatite nanoparticles on proliferation and apoptosis of osteoblast-like cells.MethodsCetyltrimethylammnonium bromide (CTAB) was used to regulate the size of nano hydroxyapatite (nHAP) particles.All obtained particles were characterized by transmission electron microscopy (TEM),X-ray diffraction,dynamic light scattering and chemical analysis.HAP films were obtained by slowly coating cover glasses with 1％ HAP particle suspension.MG-63 cells on three different films(20HAP,40HAP and 80HAP) were cocultured for up to 5 days.Cell proliferation assay was obtained by methyl thiazolyl tetrazolium (MTT).Cell apoptosis was detected by flow cytometric detection.Cell ultrastructure morphology was observed by TEM observation.ResultsnHAP with diameter of 20 nm,40 nm and 80 nm were synthesized and and analyzed.The MG-63 cells were cultured on three different fihns.The optical density value of cells on 20HAP was 1.22±0.13 after 5 days incubation,and there was no different compared to the control group(F=6.843,P=0.124).Cell number and viability were significantly higher on 20HAP compared to large nHAP after 5 days incubation.The percentage of apoptotic cells increased with increasiug nHAP particle size.TEM images showed 20HAP was found in cytoplasm and cell morphology had no changes.ConclusionBoth cell proliferation and cell apoptosis are related to the size of the nHAP particles.20HAP was the most effective on promoting cell growth and inhibiting cell apoptosis.

Percutaneous compression plating versus short reconstruction nail for the treatment of intertrochanteric hip fractures / 中华骨科杂志

Objective To compare the clinical results of percutaneous compression plating (PCCP)and Trigen short reconstruction intramedullary nail for intertrochanteric hip fractures. Methods During 2005 and 2008, the patients suffered with AO/OTA Al and A2 intertrochanteric hip fractures were divided into two groups; 36 fractures were treated with PCCP and 48 fractures with Trigen short reconstruction nail.During an average of (16.3±3.2) months follow-up, clinical evaluation involved visual analogue scale(VAS)score for pain in the 1st week, the 1st month, the 3rd month, the 6th month and the 12th month, and a Harris hip score one year post operation. Radiographs were examined for fracture healing-time, displacement scale of the neck screws and fracture impaction scale. All the complication in both groups was recorded. Results There were no difference in blood loss and operation time in both groups. The postoperative pain was significantly lower in the PCCP group in the initial three months after the surgery. Larger scale of fracture impaction and screw telescoping were seen in PCCP group. Also shorter healing time, higher Harris score results were achieved in PCCP group than those of Trigen short reconstruction nail group. Four peri-implant fractures occurred in Trigen short reconstruction nail group, which included one in the greater trochanter and three in the femoral shaft, but only one case need revision for bone displacement. In PCCP group, it was found that the superior neck screw was slightly displaced for tendency to cut-out in one patient. Conclusion Both PCCP and Trigen short reconstruction intramedullary nail can be successfully used to treat Al and A2 intertrochanteric hip fractures with minimal invasive technique. And the PCCP showed more rapid pain relief and bone healing, easily bony reduction and fewer complications.

Theoretical analysis of changes in femoral stresses after total hip arthroplasty / 生物医学工程学杂志

Changes in bone stress in the proximal femur following implantation can be estimated with the use of composite beam theory. The aim of this study was to construct the mathematical analytical models for predicting the degree of stress shielding and to test the validity of the predictions using finite element simulation. To define the periprosthetic bone stress values, the proximal femur was divided into eleven equidistant cross sections, then each section was divided into four quadrants corresponding to the anterior, posterior, medial and lateral aspects of the femur. Bone stress values were calculated by both mathematical analytical models and finite element analysis, then linear regression analyses produced slopes and R-values that show numerical and finite element results corresponding well to intact femur and both the types of fixation with/without cement. And the results also showed that femoral bone stress shielding by both the prostheses occurred in most periprosthetic zones. The most serious regions occurred in the proximal medial quadrant. This study has succeeded in creating the mathematical analytical models to predict the bone, cement and prostheses stress values, and thus can help us to evaluate the mechanical behavior of total hip replacement, to further understand the distinction between different fixation, and to make advances in implant design, surgical technique and long-term results.

Nonlinear Finite Element Analysis of Lumbar Spine Stress at Various Loading / 中国运动医学杂志

Objective In order to probe the possible biomechanical mechanism of lumbar vertebral injuries, we studied the nonlinear stress distribution on lumbar vertebrae at 1500N axial compression force and 15Nm bending moments during hambar flexion, extension, lateral bending and axial torsion using an available nonlinear finite element (FE) model of functional spine unit. Methods Three-dimensional nonlinear FE model was created based on CT data of L3-L4 motion segment. The segment mechanical responses to different loadings were evaluated by the range of disc bulging, the stress level of fibrousrings, facet loadings and equivalent stress distribution of posterior structure. Results Compression and flexion induced disc bulging in anterior region, whereas extension and lateral bending induced disc bulging posteriorly and posterolaterally. Axial torsion caused not only higher unilateral facet stress but also the concentrated stress on posteroleteral fibrousrings stress. The loadings in extension and axial compression were lower than in torsion but higher than in lateral bending and anterior flexion. Higher equivalent stress was found when compression and extension loadings were applied to the pedicle of vertebral arch and interarticularis. Conclusion Intervertebral disc beared higher compressive than tensile. The posterolateral regions of lumbar vertebrae were prone to be deformity and at higher risk of fibrousring failure. Stress failure could be occured when facets were overloaded with axial torsion,extension and extension force due to the importance of facets during lumbar movement.