Preparation of self-microemulsion gel drug delivery system of Carthamus tinctorius extract based on Mentha haplocalyx oil as oil phase / 中草药

Objective: To prepare the self-microemulsion gel drug delivery system of Carthamus tinctorius extract based on Mentha haplocalyx oil as oil phase. Methods: M. haplocalyx oil was used as the oil phase, and C. tinctorius extract was used as the water phase. The prescription of self-microemulsion were optimized by pseudo-ternary phase diagram, the process and prescription of gel were screened by single-factor method and the appearance, viscosity and pH value were evaluated. Result: The optimal formulation of CTE-SMEDDS-BGs was as following: F68 was the emulsifier, anhydrous ethanol was the co-emulsifier, the Km ratio was 1:1, and the total amount of emulsifier and co-emulsifier to M. plocalyx oil was 8:2, carbopol-980 was 2%, glycerin was 6%, and C. tinctorius extract was 5 mL. The CTE-SMEDDS-BGs was obtained by adding the CTE-SMEDDS into swelling gel matrix and triethylamine was used to adjust the pH to 6.0. The characteristics of appearance were yellow translucent, moderate viscosity, uniform and delicate, non-greasy, and easy to spread on the skin, the viscosity was 4.98 × 104 mPa•s (RSD was 1.53%), pH was 6.04 (RSD was 0.44%). Conclusion: The CTE- SMEDDS-BGs with M. plocalyx oil as oil phase is simple and stable, and meets the requirements of gel topical preparations.

Preparation of Oxymatrine Phospholipid Complex Solid Lipid Nanoparticles Lyophilized Powder and Evaluation of Its Quality / 中国实验方剂学杂志

Objective: To prepare oxymatrine phospholipid complex solid lipid nanoparticles(OMT-PC-SLN) lyophilized powder and evaluate its pharmaceutical properties. Method: Pseudo-ternary phase diagram was employed to optimize the formula of microemulsion;single factor experiments were adopted to optimize the formulation process of OMT-PC-SLN lyophilized powder with encapsulation efficiency as index;the morphology of this preparation was observed by transmission electron microscope(TEM).The particle size was measured by particle size analyzer and the in vitro release performance of OMT-PC-SLN lyophilized powder was examined. Result: Optimal formulation process was as following:taking soybean phospholipid and polyethylene glycol 15-hydroxystearate(Kolliphor HS 15) as the emulsifier,ethanol as co-emulsifier,ratio of emulsifier to co-emulsifier(Km)=3:2,oil phase:(emulsifier+co-emulsifier)=1:9,oxymatrine phospholipid complex-stearic acid-soybean phospholipid-Kolliphor HS 15-ethanol(30:100:180:360:360);taking 50 mL of 4%mannitol solution as the external aqueous phase,ice bath stirring at 1 000 r·min-1 and solidifying for 1 h,precooled at -20℃ for 24 h,took out and dried for 24 h.OMT-PC-SLN lyophilized powder was spherical in appearance with encapsulation efficiency of (38.09±1.24)%,average particle size of 785.5 nm,polydispersity coefficient(PDI) of 0.456 and the Zeta potential of -24.82 mV.The cumulative release rates of OMT-PC-SLN lyophilized powder were 72.63%at 2 h and 98.42%at 12 h;the cumulative release rate of oxymatrine(crude drug) was 98.60%at 2 h. Conclusion: This optimized formulation process of OMT-PC-SLN lyophilized powder is stable with good repeatability;compared with oxymatrine,OMT-PC-SLN lyophilized powder has a certain sustained-release effect.

Biomechanical comparison between resurfacing hip arthroplasty and normal proximal femur / 医用生物力学

Objective To investigate the variation of stress distributions on proximal femur after hip resurfacing arthroplasty (HRA) by using three-dimensional (3D) finite element method. Methods The 3D finite element model of proximal femur was reconstructed based on 64-slice spiral CT scan image data. Both the stress distributions on proximal femur after metal-on-metal HRA and normal proximal femur were studied, so as to analyze the biomechanical environment changes after HRA. Results After HRA, the superior, anterior, rear and inferior area of the proximal femoral head showed significant stress shielding, with peak stress of 0.60, 0.57, 0.66, 0.79 MPa, respectively, and stress shielding rate of 99.80%, 99.16%, 98.92%, 96.66%, respectively. Increased stress occurred in most regions of the distal femoral head, while stress shielding appeared only in rear area of the distal femoral head, with stress shielding rate of 4.92%. Increased stress occurred in anterior region of the proximal femoral neck, while stress shielding appeared in the superior, inferior and rear area of the proximal femoral neck, with shielding rate of 16.48%, 22.75% and 7.83%, respectively. Increased stress also occurred in inferior area of the distal femoral neck, while the remaining area showed stress shielding. The stress in greater trochanter increased by 9.22%, and the stress shielding rate for lesser trochanter area and basal area of femoral neck were 2.49% and 14.44%, respectively. Conclusions Stress distributions on most regions of proximal femur after HRA were similar to that on normal femur, and the stress transfer was close to physiological status, which could effectively avoid obvious stress shielding in proximal femur and preserve bone mass, which could contribute to normal physiological activity of patients.

Anatomy study on the fixation technique of buttress plate in the posterior column of the acetabulum / 中国骨伤

<p><b>OBJECTIVE</b>To solve the problem of screw penetrating the joint surface easily by determining the angle of inclination and the mean longth screw plated on the posterior column.</p><p><b>METHODS</b>Ten specimens of adult male cadavers, aged 20 to 74 years old, averaged 54.5 years old, were collected. After removal of the bilateral femurs from the hip joints, and sawing through the sacral and pubic symphysis in the median sagittal plane, 20 semi pelvic specimens were used for this study when the osseous abnormalities were excluded. The specimens were air dried naturelly after the soft tissue attaching to the pelvis had been eliminated. The margin of superior acetabular and inferior acetabular were determined, and the serial cross-sections of the acetabular posterior column were made. The width of posterior column,the width of acetabulum,the width ratio of acetabulum to posterior column, the angle of inclination and the mean length of screw on all entry points were measured. Defined the level parallel to 1/2 section of superior acetabulum was cross-section B; 1/2 section of acetabulum was C; 1/2 section of inferior acettabulum was D. At the different levels, defined the entry point on the outer edge of posterior column of the acetabulum or the trailing edge of acetabulum was B0, C0 or D0; lateral 1/2 of posterior column of the acetabulum was B1, C1 or D1; 1/2 of posterior column of the acetabulum was B2, C2 or D2; medial 1/2 of posterior column of the acetabulum was B3, C3 or D3; the inner edge of posterior column of the acetabulum was B4,C4 or D4.</p><p><b>RESULTS</b>On cross-section B, the angle of inclination and the mean length of screw at B0 was 41 degrees and 44.0 mm; at B1 was 66 degrees and 42.2 mm; at B2 was 91 degrees and 59.5 mm; at B3 was 107 degrees and 64.0 mm; the maximum angle and the mean length at point B4 was 123 degrees and 65.5 mm; the minimum angle and the mean length at point B4 was 109 degrees and 59.0 mm. On cross-section C,the angle and the mean length at point CO was 39 degrees and 39.0 mm; at C1 was 57 degrees and 36.0 mm; at C2 was 74 degrees and 36.0 mm;at C3 was 90 degrees and 36.0 mm; at C4 was 106 degrees and 76.0 mm. On cross-section D,the angle and the mean length at DO was 42 degrees and 35.5 mm; at D1 was 61 degrees and 33.0 mm; at D2 was 81 degrees and 32.0 mm; at D3 was 100 degrees and 31.0 mm; at D4 was 120 degrees and 74.0 mm.</p><p><b>CONCLUSION</b>When using the fixation technique of acetabular posterior column plate, the angles of screw-posterior column are 40 degrees to 60 degrees, 60 degrees to 75 degrees, 75 degrees to 90 degrees and 90 degrees to the angle of parallel to the square area respectively on the region of outer 1/4,outer-middle 1/4,inner-middle 1/4 and inner 1/4 of the acetabulum region, and the screw length is 30 mm.</p>

Evaluation of early clinical results of two stage hip replacement after failed internal fixation for femoral neck fractures / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the early clinical results of two stage hip replacement after failed internal fixation for femoral neck fractures in young patients.</p><p><b>METHODS</b>From June 2008 to June 2010,24 patients with femoral head necrosis caused by failed internal fixation were treated with hip arthroplasty. Among them, 12 patients were male and 12 patients were female, with an average age of 42.9 years old (ranged, 18 to 58). According to Harris score and X-ray examination, the clinical result was evaluated.</p><p><b>RESULTS</b>Twenty-three cases were followed up with an average age of 34.4 months (ranged, 25 to 48). After operation, 1 case complicated with the dislocation of hip joint. No deep infection of hip joint, prosthetic loosing or peripheral fracture was found. The mean Harris score was 90.9 +/- 4.3, and 18 obtained excellent results, 4 good and 1 fair.</p><p><b>CONCLUSION</b>Although treatment of femoral head necrosis with two stage hip replacement after failed internal fixation is difficult during operation, its early result is satisfactory.</p>

Efficacy and safety of rh-endostatin combined with docetaxel in second-line or intolerant toxicity for first-line treatment in patients with advanced non-small cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To analyze the efficacy and safety of combination of rh-endostatin (Endostar) with docetaxel treatment on patients of non-small cell lung cancer (NSCLC) who presented PD or intolerable toxicity in/after first-line chemotherapy.</p><p><b>METHODS</b>A randomized, double-blind, placebo-controlled and multi-center clinical trial was conducted. Patients with stage IIIB/IV of NSCLC experienced previous chemotherapy of one-regimen were screened for this trial. A total of 68 cases were included in this study. Single docetaxel and that combined with endostar were conducted in two arms. The response, time to progression (TTP) and adverse effects were observed in both arms.</p><p><b>RESULTS</b>The objective response rate (ORR) and clinical benefit rate (CBR) were 0 and 62.5% in the combined arm, along with 0 and 53.3% in the single docetaxel arm, with a non-significant difference between the two groups (all P > 0.05), respectively. The median TTPs in the combined and single docetaxel arms were 2.63 and 2.07 months, respectively (P = 0.079). The median TTPs of the participants with progressive disease (PD) after first-line chemotherapy were 1.33 and 1.67 months in the combined and single docetaxel arms, respectively (P = 0.946). The median TTPs of the participants with intolerant adverse effects in first-line chemotherapy were 4.70 months and 3.17 months in the combined and single docetaxel arms, respectively (P = 0.070). The median TTPs of the patients with SD after 2 therapeutic cycles in the combined and single docetaxel arms were 6.23 months and 3.27 months, respectively (P = 0.040). The differences between two arms were non-significant in adverse, serious adverse and cardiovascular adverse effects (all P > 0.05).</p><p><b>CONCLUSIONS</b>Endostar may prolong TTP in patients with advanced NSCLC benefited from docetaxel treatment without increased toxicities.</p>

Short-term result of hip resurfacing arthroplasty in the treatment of patients with femoral head necrosis / 中国骨伤

<p><b>OBJECTIVE</b>To study short-term results of hip resurfacing arthroplasty (HRA) in the treatment of patients with avascular necrosis of femoral head (ANFH), and to explore indication and strategy in this surgery.</p><p><b>METHODS</b>From December 2006 to December 2009, 37 patients (43 hips) with avascular necrosis of femoral head were treated with total hip resurfacing arthroplasty. Among the patients, 25 patients were male and 12 patients were female, with an average age of 44.5 years (ranged, 21 to 67 years). According to ARCO classification, 3 hips were 3A stage, 6 hips were 3B stage, 16 hips were 3C stage and 18 hips were 4 stage. X-ray evaluation of the patients were conducted. The clinical results were evaluated by the Harris hip score system including pain,range of motion, correction of deformity and total function.</p><p><b>RESULTS</b>Thirty-four patients (40 hips) were followed up with an average period of 32.4 months (ranged, 16 to 53 months), and 3 patients were lost. Thirty-seven hips got complete relief of joint pain and 3 patients feel aching pain after walking. There was 1 heterotopic ossification, no femoral neck fracture no dislocation, no infection and no revision in all patients. From pre-operation to present, the average Harris hip score improved significantly from (51.5 +/- 1.7) to (94.3 +/- 1.4). Thirty-seven hips got an excellent result, 3 hips good and no poor.</p><p><b>CONCLUSION</b>The total hip resurfacing arthroplasty is an effective solution for the problems of the younger and active patients with ANFH, and the short-term results are satisfying.</p>

Case-control study on acute colonic pseudo-obstruction after total hip or knee arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the incidence, predisposing factors and therapeutic modalities of acute colonic pseudo-obstruction (ACPO) in patients after total hip arthroplasties (THA) and total knee arthroplasties (TKA).</p><p><b>METHODS</b>From January 2006 to December 2009, 12 patients with ACPO after THA and TKA operation were investigated retrospectively,who were viewed as the ACPO group. There were 10 males and 2 females with an average age of (78 +/- 12) years in the ACPO group. Other 853 patients without ACPO after THA and TKA operation were viewed as the control group treated at the same period. The incidence of ACPO was calculated. The clinical data were collected and compared between the two groups including patient age, gender, procedure, anesthetic class, clinical presentation, radiographic findings, duration from index surgery to diagnosis of ACPO, treatment, postoperative mobilization time, and length of hospital stay.</p><p><b>RESULTS</b>The incidence of ACPO was 1.4%. The incidence of primary THA (1.3%) was higher than that of primary TKA (0.4%); the incidence of hip and knee revisions (5.0%) was higher than that of primary THA and TKA (1.0%); there was no difference in incidence between hip revisions (5.5%) and knee revisions (4.0%). The mean age was (78 +/- 12) years old in ACPO group and (71 +/- 13) in the control group. The male/female ratio was 5:1 in ACPO group and 2:3 in control group. There were statistical differences in mean age and gender ratio between the two groups. No association was found with respect to anesthetic class. On average, ACPO occurred at 2.5 days after index surgery. The abdominal distention occurred in all 12 cases, nausea or vomiting in 8 cases and abdominal pain in 3 cases. Radiographically cecal dilation occurred in all cases and intestinal dilation in 3 cases. All patients initially were treated conservatively with immediate cessation of oral intake,a nasogastric tube and oral mineral oil. Three patients received a rectal tube. Only 1 patient required endoscopic decompression. There were no deaths after ACPO in the series. Mean mobilization time after surgery averaged (5.0 +/- 2.2) days in ACPO group compared with (2.5 +/- 1.1) days in the control group. Mean hospital stay averaged (16.5 +/- 6.4) days in ACPO group compared with (10.5 +/- 4.5) days in the control group. There were statistical differences in mean mobilization time after surgery and mean hospital stay between two groups.</p><p><b>CONCLUSION</b>ACPO mainly happened in old male patients. The majority cases response to conservative treatment and their prognoses are good. But ACPO will delay mobilization time after surgery and increase hospital stay.</p>

Effect of ginsenoside Rg1 on the spatial learning-memory ability in dementia rats after transplanted with bone marrow mesenchymal stem cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effect and mechanism of ginsenoside Rg1 on the spatial learning-memory ability in rats with Alzheimer's disease after transplanted with bone marrow mesenchymal stem cells (BMSCs).</p><p><b>METHODS</b>Using digital randomization table method, seventy-five male SD rats were divided into the bilateral FF transection model group (as the model group: ambi-hippocampal fimbria-fomix transected), the sham-operative control group (the SOC group: receiving the same modeling process as the model group, but without ambi-hippocampal fimbria-fomix transected), the ginsenoside Rg1 treatment group (as the treatment group: Two weeks after modeling ginsenoside Rg1 was peritoneally injected at the dose of 5 mg/kg, once daily for four weeks in total), the BMSCs transplanted treatment group [as the control group: Two weeks after modeling every rat received transplantation of BMSCs (10 microL, 1 x 10(6) cells)], and the ginsenoside Rg1 + BMSCs treatment group (as the combination group: They received both transplantation of BMSCs and peritoneal injection of ginsenoside Rgl). The spatial learning-memory ability of rats was detected by Morris water maze and the escape latency (s) was recorded, mRNA expression of nerve growth factor (NGF) was detected using Real-time PCR.</p><p><b>RESULTS</b>Six weeks after the hippocampal fimbria-fomix (FF) transection, the escape latency o feach medication group was obviously shorter than that of the model group, and the spatial learning-memory ability of dementia rats was somewhat improved. The spatial learning-memory ability of rats in the combination group was (29.95 +/- 2.03) and the mRNA expression level of NGF was (1.13 +/- 0.15), better than those in the BMSCs group (44.36 +/- 1.43, 0.78 +/- 0.09, P<0.05).</p><p><b>CONCLUSIONS</b>Ginsenoside Rg1 could strengthen the spatial learning-memory ability in dementia rats after transplanted with BMSCs. Its mechanism might be possibly correlated with up-regulating mRNA expression of NGF in basal forebrain after BMSCs transplantation.</p>

Comparison of humeral head replacement and internal fixation for the treatment of 3 parts and 4 parts fractures of proximal humerus in the elderly / 中国骨伤

<p><b>OBJECTIVES</b>To compare the indication, technical keys during surgery and early results of humeral head replacement and internal fixation for the 3 parts and 4 parts fractures of proximal humerus in the elderly.</p><p><b>METHODS</b>From July. 2004 to July. 2006,58 patients with 3 parts and 4 parts fractures of proximal humerus were randomly treated with AO locked compressive plates (LCP) or humeral head replacement. In LCP group, there were 12 males and 16 females with an average age of (66.5 +/- 1.4) years, including 24 cases of 3 parts fractures, 1 case of 3 parts fractures with dislocation, 2 cases of 4 parts fractures and 1 case of 4 parts fractures with dislocation. In the humeral head replacement group,there were 12 males and 18 females with an average age of (68.9 +/- 3.5) years, including 9 cases of 3 parts fractures, 2 cases of 3 parts fractures with dislocation, 12 cases of 4 parts fractures, 4 cases of 4 parts fractures with dislocation and 3 cases of humeral head split fractures. Trauma series X-rays of shoulder were taken after operation, 2-week, 6-week, 10-week, 16-week, 6-month and the latest followed-up. VAS, SST (simple shoulder test) questionnaire, ASES (American shoulder & elbow surgeon)score, Constant-Murley score and UCLA score had been adopted for evaluation at the latest followed-up.</p><p><b>RESULTS</b>The mean followed-up period of LCP group was 29.8 months and that of humeral head replacement group was 28.2 months. VAS of LCP group and humeral head replacement group were (2.2 +/- 1.5) and (2.6 +/- 1.9), respectively. There was a statisticaly difference between the two groups (P = 0.002). The degrees of forward elevation of shoulder in LCP group and humeral head replacement group were 110.2 degrees (81 degrees to 130 degrees) and 120.2 degrees (89 degrees to 140 degrees), respectively. There was a statistical difference between the two groups (P = 0.031). ASES score, Constant-Murley score, UCLA score and response "yes" in SST questionnaire in LCP group were 87.7 +/- 2.2, 83.9 +/- 6.8, 30.3 +/- 2.2, 8.0 +/- 0.9, and in humeral head replacement group were 86.4 +/- 4.5, 85.5 +/- 5.6, 31.2 +/- 2.1, 9.0 +/- 0.7, respectively. There was no significant difference between the two groups in ASES score, Constant-Murley score, UCLA score and SST questionnaire.</p><p><b>CONCLUSION</b>Both humeral head replacement and internal fixation are effective treatment for the 3 parts and 4 parts fracture of proximal humerus in the elderly. Humeral head replacement is more technically demanding and has a strict indications. The satisfactory results of humeral head replacement are based on the suitable placement of prostheses and the correct reconstruction of rotator cuff insertion.</p>

Hip resurfacing arthroplasty in patients with ankylosing spondylitis / 中国骨伤

<p><b>OBJECTIVE</b>To study the short-term results of metal on metal hip resurfacing arthroplasty (HRA) for the treatment of patients with ankylosing spondylitis (AS), to explore the indications and technology of this surgery.</p><p><b>METHODS</b>From February 2006 to April 2008, 11 patients (15 hips) with ankylosing spondylitis were treated with metal on metal total hip resurfacing arthroplasty. Among them, 9 patients were male, and 2 patients were female, with an average age of 32.5 years (ranged from 16 to 53 years). The comparative study on preoperative and postoperative pain, range of motion, correction of deformity and function evaluation were performed. The preoperative and postoperative Harris scores were compared and the feasibility and technical difficulty were analyzed.</p><p><b>RESULTS</b>Ten patients were followed up for an average period of 16.2 months (ranged from 8 to 34 months) and 1 patient was lost. Pain disappeared in 10 patients. There were no heterotopic ossification, no femoral neck fracture, no dislocation, no infection and no revision in all patients. From preoperation to present, the mean flexion angle of hip was improved from preoperative 0 degrees to 75 degrees to postoperative 35 degrees to 105 degrees; the mean abducting angle of hip was improved from preoperative 0 degrees to 30 degrees to postoperative 15 degrees to 55 degrees; and the average Harris hip score improved significantly from (30.9 +/- 3.4) (2-47) to (85.1 +/- 3.1) (46-94). According to evaluation criteria, 10 hips got an excellent result, 3 good and 1 poor.</p><p><b>CONCLUSION</b>The total hip resurfacing arthroplasty is an effective solution for the treatment of the younger and active patients with AS and it shows satisfactory short-term results. It is very significant to analysis the different conditions of patients so as to choose proper strategy.</p>

Strategy of prevention and management of intraoperative fractures of acetabulum during primary total hip arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To analyse the causes and resultes of intraoperative occurrence of an acetabular fracture in primary total hip arthroplasty and discuss propriate prevention and treatment of this problem.</p><p><b>METHODS</b>Between July 2004 and December 2006, 326 primary total hip arthroplasties were retrospectively reviewed and found that eleven patients (eleven hips) had sustained an intraoperative acetabular fracture involving 7 male and 4 female,aged from 37 to 71 years (mean 54 years). Analyzed the causes of fractures, the anatomic location, treatment and outcome of the fractures. Acetabular component designs were categorized and each design was analyzed for fracture risk.</p><p><b>RESULTS</b>Among 11 cases, the fractures occurrenced as setting the prosthesis in 6 cases, grinding and drilling in 3 cases, drawning hook in 2 cases. There were 5 cases of central type fracture, 3 of posterior-wall, 2 of anterior, 1 of posterior-upper. Nine of these patients (nine hips) had been followed-up for 12 to 29 months(mean 18 months). There were no heterotopic ossification, no dislocation, no deep venous embolism. All fractures were healing.</p><p><b>CONCLUSION</b>Acetabular fracture during primary total hip arthroplasty is a complication of acetabular fixation without cement, which should be think highly of. In the present series, retention of a stable cup is associated with uneventful osseous in growth and excellent early-term outcomes.</p>

Feasible study of the minimal-invasive surgical treatment for the pelvis fractures / 中国骨伤

<p><b>OBJECTIVE</b>To discuss feasibility of minimal-invasive surgical treatment of the pelvis fractures.</p><p><b>METHODS</b>Twenty-six patients with pelvis fractures were treated by micro-surgical treatment. There were 15 male and 11 female with an average age of 40 years ranging from 20 to 62 years. All patients were closed fractures, 17 patients were hemi-pelvis fractures, 9 patients were bilateral-pelvis fractures. The fracture type of posterior ring of pelvis as follows:8 patients were sacro-iliac joint dislocation, 12 patients were vertical section fractures in the outboard of the sacrum. The fracture type of anterior ring of pelvis as follows: 9 patients were hemi-fracture of rami ossis pubisi or hemi-fracture of rami ischi, 7 patients were bilateral-fracture of rami ossis pubisi or bilateral-fracture of rami ischii, 6 patients were separation of symphysis pubis. Six patients accompanied with shock. Anterior ring of pelvis was fixation by lag screw via superior ramus of pubis and pubic symphysis; Posterior ring of pelvis was fixation by lag screw via sacroiliac joint or intrasacral rod via ilium. X-ray films and multi-slice spiral CT of pelvis was obtained in order to understand exterior and inner details about pelvis fractures. Adopt orientation in body and inducted by C-arm digital subtracting X-ray system when operating.</p><p><b>RESULTS</b>Blood loss was about 10 to 50 ml (mean 30 ml). Operation time was 30 to 50 minutes. Time of fracture union was 8 to 12 weeks (mean 11 weeks). Wound infection, ununion of fracture and nerve injuries had not been found.</p><p><b>CONCLUSION</b>Minimally invasive operation has the merit of short operation time, fine effect, soon recovering and few complication.</p>

The effect of rotational alignment of the femoral components on the patellofemoral biomechanics in total knee arthroplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To study the effect of rotational alignment of the femoral components on the patellofemoral biomechanics in total knee arthroplasty (TKA) demonstrated on autopsy specimens, as the guide for surgeons to choose the correct reference axis for rotational alignment of the femoral components and to reduce the patellofemoral joint complications.</p><p><b>METHODS</b>Select 9 frozen fresh human cadaver knees without gross deformities or instabilities and mount specimens on a patellofemoral joint testing jig connected to a Model 8501 Instron machine (Instron Corporation, Canton, MA). The study simulated the action of squatting from the standing position with the foot firmly planted. Standard TKA was performed in each specimen by the same senior surgeon using Nexgen LPS total knee system (Zimmer Corporation, Warsaw Indiana). Alter rotational alignment of the femoral components referenced to the transepicondylar axis and the Whiteside's line respectively. Measure biomechanics of the patellofemoral joints using Fuji prescale film at 30 degrees , 60 degrees , 90 degrees , 120 degrees of knee flexion respectively. The digital values were obtained by the handheld pressure measurement systems (FPD-305E, FPD-306E) and Autocad software.</p><p><b>RESULTS</b>The rotational alignment of the femoral components paralleled to the transepicondylar axis had the best results of the peak value of the patellofemoral contact pressure (P < 0.05). There were no statistically significant differences in patellofemoral contact area (P > 0.05). But the patellofemoral contact area had the close correlations to the angles of the knee flexion and the specimens.</p><p><b>CONCLUSIONS</b>Rotational alignment of the femoral components has a great influence on the patellofemoral contact pressure in total knee arthroplasty. It is reliable for surgeons to choose the transepicondylar axis as the reference axis to rotate femoral components.</p>