Objective To assess the feasibility, safety, and validity of the TC-Dynamic posterior stabilized prosthesis implanted in the total knee arthroplasty (TKA). Methods Twelve knees of 10 patients (the TC-Dynamic group) were followed up, who had been implanted with the TC-Dynamic posterior stabilized prosthesis from September 2003 to March 2004. Preoperative KSS knee scores were 16.08±11.58, function scores 13.75±19.79, and the range of motion (ROM) of the knee 75.00±26.46°. Meanwhile, 50 knees of 30 patients (the Scorpio group) werefollowed up, who had undergone TKA with the Scorpio posterior stabilized prosthesis.Preoperative KSS knee scores were 19.48±967, function scores 3.16±19.82,andthe ROM of the knee 80.80±22.82°. The anteroposterior and lateral X-ray filmsof each knee were examined before and after operation. The statistical Z-test was used to analyze the differences between the 2 groups in the improvement of the KSS knee scores, function scores, and ROM after operation. Results The average of the 130 days’ follow-up revealed that the patients implanted with the TC-Dynamic prosthesis had an excellent result. In the TC-Dynamic group, the KSS knee scores were 88.83±4.04 with improved scores of 72.75±14.47 compared with those before operation; function scores were 79.17±5.15 with improved scores of 65.42±19.47; the ROM of the knee was 107.92±11.57° with increased degrees of 32.92±32.22°.Meanwhile, in the Scorpio group, the KSS knee scores were 85.68±7.36 with improved scores of 66.20±10.44 compared with those before operation; function scores were 71.40±12.70 with improved scores of 68.24±25.35; the ROM of the knee was 109.20±11.13° withincreaseddegrees of 28.40±26.41°.There was no significant difference in the improvement of the KSS knee scores, function scores, and ROM after operation between the 2 groups （Pgt;0.01）. All the X-ray films of the knees implanted with both the Scorpio prosthesis and the TC-Dynamic prosthesis were analyzed.No malalignment or lucent line with the prosthesis was seen in all these X-ray films. Conclusion The short-term follow-up indicates that the patients implanted with the TC-Dynamic prosthesis have an excellent result. The TC-Dynamic prosthesis with a scientific and proper design is more suitable for the Chinese. However, the long-term outcome of the patients implanted with the TC-Dynamic prosthesis should be observed in a larger number of TKA operations. The basic surgical principles, including excision of both the cruciate ligaments and correction of thebone deformity with the proper balancing of the soft tissues in flexion and extension, are still crucial to successful TKA and to the longterm high survivalrate of the knee prosthesis.
Objective To investigate an artificial intelligence (AI) automatic segmentation and modeling method for knee joints, aiming to improve the efficiency of knee joint modeling. Methods Knee CT images of 3 volunteers were randomly selected. AI automatic segmentation and manual segmentation of images and modeling were performed in Mimics software. The AI-automated modeling time was recorded. The anatomical landmarks of the distal femur and proximal tibia were selected with reference to previous literature, and the indexes related to the surgical design were calculated. Pearson correlation coefficient (r) was used to judge the correlation of the modeling results of the two methods; the consistency of the modeling results of the two methods were analyzed by DICE coefficient. Results The three-dimensional model of the knee joint was successfully constructed by both automatic modeling and manual modeling. The time required for AI to reconstruct each knee model was 10.45, 9.50, and 10.20 minutes, respectively, which was shorter than the manual modeling [(64.73±17.07) minutes] in the previous literature. Pearson correlation analysis showed that there was a strong correlation between the models generated by manual and automatic segmentation (r=0.999, P<0.001). The DICE coefficients of the 3 knee models were 0.990, 0.996, and 0.944 for the femur and 0.943, 0.978, and 0.981 for the tibia, respectively, verifying a high degree of consistency between automatic modeling and manual modeling. Conclusion The AI segmentation method in Mimics software can be used to quickly reconstruct a valid knee model.
Objective To design a new custom-made artificial semi-knee joint based on rapid prototyping(RP) technique and to explore a method to solve necroses of allocartilage in hemi-joint allotransplantation. Methods Based on the extracted 3D contour image of the articular cartilage of femoral condyle, the custom-made artificial semi-knee joint was designed with Surfacer 9.0 image processingsoftware. The artificial semi-knee joint design used the femoral condylar 3D contour of the patient as the outer face and the subchondral bone 3D contour of allograft bone as inner face. One dado for medullary nailand two for special designing cages which were used to fix the cartilage into the allograft were added on the inner face. After being converted into RP data format, the computerassisted design was imported into the LPS600 rapid prototyping machine, and the prototype was achieved. Furthermore, the prototype could be modified by hand according to the design. Then the RP model was used as a positive mould to build up a silica gel negativemould, and the negative mould was sent to the factory to manufacture Ti-6Al-4V alloy articular cartilage through ordinary mould-melted founding process. Finally, the whole metal cartilage was completed after melting two special cages on it andpolishing it. Results A new custom-made artificial semi-knee joint was made ad used to treat a 14-year old patient. The custom-made artificial semi-knee joint and the subchondral bone were a perfect match. The operative result was satisfactory. The patient could walk 5 weeks after operation. The bone healing of the auto-bone and allo-bone was achieved 6 months later. A follow-up period lasting 1 yearshowed that the knee joint played a good function. Conclusion The artificial semi-knee joint is a good match for the allograft boneand a good idea to solve necroses of allocartilage in hemijoint allotransplantation.
ObjectiveTo explore the correlation between the degree of bone marrow edema (BME) and the content change of tumor necrosis factor α (TNF-α) and matrix metalloproteinase 3 (MMP-3) and the knee pain symptoms in patients with bone contusion around the knee joint. MethodsThirty patients (30 knees) of bone contusion around the knee joint were chosen as the trial group between October 2009 and April 2012. According to visual analogue scale (VAS), 30 patients were divided into mild group (10 cases), moderate group (10 cases), and severe group (10 cases); according to MRI morphological changes, the patients were divided into type I group (12 cases), type Ⅱ group (11 cases), and type Ⅲ group (7 cases). Ten patients (10 knees) with soft tissue injury of the knee were chosen as control group. No significant difference was found (P>0.05) in gender, age, causes, side, and admission time after injury between 2 groups. The serum contents of MMP-3 and TNF-α were detected and statistically analysed between different degrees of pain groups and between different degrees of BME groups. Correlation was analysed between BME and inflammatory factor changes and VAS score. ResultsThe MMP-3 and TNF-α contents in trial group[(29.580±6.870) μg/L and (23.750±7.096) ng/L] were significantly higher than those in control group[(8.219±1.355) μg/L and (6.485±1.168) ng/L](t=9.686, P=0.000; t=7.596, P=0.000). The MMP-3 and TNF-α contents in patients with different degrees of pain and BME were significantly higher than those in patients of control group (P<0.05), and significant difference was found between patients with different degrees of pain (P<0.05), but no significant difference between patients with different degrees of BME (P>0.05). Multiple linear regression analysis showed that TNF-α content was significantly correlated with VAS score (P=0.000). ConclusionKnee pain symptoms are not related to the degree of BME in patients with bone contusion around the knee joint. Inflammatory factor TNF-α content is the main influence factor of knee joint pain symptoms.
Objective To analyze the correlation between the morphology of tibial intercondylar eminence and non-contact anterior cruciate ligament (ACL) injury, and provide a theoretical basis for the prevention and risk identification of ACL injury. Methods A retrospective analysis was conducted on the knee radiographs of 401 patients admitted to the Chengdu Second People’s Hospital between January 2017 and October 2021, including 219 males and 182 females. Non-contact rupture of ACL was observed in 180 patients and confirmed by arthroscopy or surgery, while the remained 221 patients were confirmed to have normal ACL by physical examination and MRI. The heights of medial and lateral tibial intercondylar eminence and the width of tibial intercondylar eminence of the 401 patients were measured, and the risk factors of ACL injury were analyzed. Results The height of medial tibial intercondylar eminence was lower and the width of tibial intercondylar eminence was smaller in male patients with ACL fracture than those in the male control group with statistical significance (P<0.05). Logistic regression analysis showed that a narrow width of tibial intercondylar eminence was a risk factor of ACL injury in males (P<0.05). The receiver operating characteristic (ROC) curve showed that the diagnostic threshold was 11.40 mm, the area under the curve (AUC) was 0.851 [95% confidence interval (CI) (0.797, 0.896)], the sensitivity was 72.81%, and the specificity was 84.76%. The height of medial tibial intercondylar eminence was lower and the width of tibial intercondylar eminence was smaller in female patients than those in the female control group with statistical significance (P<0.05). Logistic regression analysis showed that both a low height of medial tibial intercondylar eminence and a narrow width of tibial intercondylar eminence were risk factors of ACL injury in females (P<0.05). For the width of medial tibial intercondylar eminence, the ROC curve showed that the diagnostic threshold was 8.30 mm, and the AUC was 0.684 [95%CI (0.611, 0.751)], the sensitivity and specificity were 63.64% and 72.41%, respectively; for the height of medial tibial intercondylar eminence, the diagnostic threshold was 11.30 mm, and the AUC was 0.699 [95%CI (0.627, 0.756)], the sensitivity was 89.39%, and the specificity was 47.41%. Conclusions The reduced width of tibial intercondylar eminence is a risk factor and effective predictor of non-contact ACL injury in males. Both the reduced height of the medial tibial intercondylar eminence and the reduced width of tibial intercondylar eminence are risk factors and may be predictors for non-contact ACL injury in females.
ObjectiveTo investigate the mid-term effectiveness of three‐dimensional (3D) printed osteotomy guide plate and personalized prosthesis in knee‐preserving tumor resection. Methods The clinical data of 12 patients who underwent knee‐preserving tumor resection and reconstruction with 3D printed osteotomy guide plate and personalized prosthesis between September 2016 and October 2018 were retrospectively analyzed. There were 7 males and 5 females. The age ranged from 7 to 59 years, with a median of 44.5 years. There were 11 cases of osteosarcoma and 1 case of fibrosarcoma, all of which were Enneking grade ⅡB. The distance from the tumor to the joint surface was 5.5-8.2 cm, with an average of 6.94 cm. Incision healing, tumor recurrence, periprosthetic fracture, and aseptic loosening were observed after operation. The Musculoskeletal Tumor Society (MSTS) scoring system was used to evaluate the function of the patients, and the knee flexion range of motion was measured. ResultsThe 12 patients were followed up 41-66 months, with an average of 54.5 months. The length of osteotomy ranged from 14 to 26 cm, with an average of 22.08 cm. Except for 2 patients with superficial infection of incision tissue, no deep infection involving the prosthesis occurred, no patient underwent revision surgery because of prosthesis infection. During the follow-up, local recurrence occurred in 2 cases and distant metastasis occurred in 3 cases. The overall disease-free survival rate was 58.3%. Two patients died of lung metastasis, and the overall survival rate was 83.3%. One patient underwent amputation due to local recurrence, and 1 patient underwent total knee arthroplasty due to prosthesis rupture. No aseptic loosening of the prosthesis and periprosthetic fracture occurred during the follow-up, and the overall prosthesis survival rate was 83.3%. At last follow-up, 10 patients obtained satisfactory knee flexion range of motion that ranged from 95° to 125°, with an average of 110°. Two children could not cooperate with early rehabilitation treatment due to pain, and the knee flexion range of motion was not ideal (50°, 75°). All patients achieved acceptable lower limb function with MSTS scores ranged from 26 to 30, with an average of 28. All patients walked without crutches. ConclusionThe treatment of malignant bone tumors around the knee joint with 3D printed osteotomy guide plate and personalized prosthesis can preserve the articular surface, obtain good limb function, reduce the risk of aseptic loosening of prosthesis, and achieve better mid-term effectiveness.
OBJECTIVE: Extension stiffness of knee joint is always treated by the quadricepsplasty, but the main deficiency of this method is that patient feels weakness of lower limb and easily kneels down. The aim of this article is to explore the method to resolve the complications after quadricepsplasty. METHODS: Since 1978 to 1997, on the basis of traditional procedures of quadricepsplasty, sartorius muscle was used to reinforce the extension of knee joint. The lower 2/3 of sartorius muscle was fully dissociated only with its insertion intact. A tendon-periosteal-bone flap, about 2 cm in width, was managed on the anterior surface of patella, with its pedicle on the medial edge of patella. The tendon-periosteal-bone flap was used to fix the dissociated sartorious into patella to reinforce the extension of knee joint. The very lower part of sartorius was mainly aponeurosis, with the help of an aponeurosis bundle of iliotibial tract, it was fixed into the insertion of patellar ligament, through a bony tunnel chiseled adjacent to the insertion of patellar ligament. By now the movement of knee joint extension was strengthened by the transferred sartorius muscle. Postoperatively, every patient was required to extend and flex knee joint actively and/or passively. Altogether 12 patients were treated, 9 of them were followed up with an average of 14 months. RESULTS: The average movement was increased from 15 degrees to 102 degrees, and the average myodynamia was improved from grade II to grade IV. CONCLUSION: Traditional quadricepsplasty co-operated with transfer of sartorius muscle can strengthen the myodynamia of knee joint extension. It is simple method and can really achieve good function.
ObjectiveTo investigate the short-term effectiveness of total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing osteotomy navigation template.MethodsA retrospective study was performed on 60 patients with osteoarthritis bewteen January 2016 and June 2017. Thirty cases underwent TKA assisted by 3D printing osteotomy navigation template (3D printing group) and 30 cases underwent the conventional TKA (conventional TKA group). There was no significant difference in gender, age, body mass index, surgical side, and disease duration between 2 groups (P>0.05). The operation time, the pre- and post-operative hemoglobin values, the amount of drainage, the Hospital for Special Surgery (HSS) score and Knee Society Score (KSS) of knee joint before operation and at 3 months after operation were observed. And 6 freedom degrees of knee (the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement, the flexion and extension angle, and the internal and external displacement) before operation and at 3 months after operation were recorded by Opti-Knee (the knee 3D motion analysis system). The values of 2 groups were compared with 30 healthy adults (<60 years).ResultsThe operation time was shorter in 3D printing group than that in conventional TKA group (t=5.833, P=0.000). The hemoglobin values at 1 and 3 days after operation were higher in 3D printing group than those in conventional TKA group (P<0.05). The amount of drainage was less in 3D printing group than that in conventional TKA group (t=5.468, P=0.000). All patients were followed up 6-9 months (mean, 7.3 months). There was no significant difference in pre- and post-operative HSS score and KSS clinical score between 2 groups (P>0.05). There was no significant difference in preoperative KSS function score between 2 groups (P>0.05), but the KSS function score of 3D printing group at 3 months after operation was higher than that of conventional TKA group (P<0.05). Before operation, the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement of 3D printing group and conventional TKA group were larger than that of the healthy adults (P<0.05); there was no significant difference in the flexion and extension angle and the internal and external displacement between 2 groups and healthy adults (P>0.05). At 3 months after operation, compared with healthy adults, the varus and valgus angle of conventional TKA group was increased, the flexion and extension angle of conventional TKA group was decreased (P<0.05); the proximal-distal displacement and the internal and external displacement of 2 groups were decreased (P<0.05); there was no significant difference in other freedom degrees between groups (P>0.05). No sign of prosthesis loosening was observed by X-ray examination.ConclusionCompared with the traditional TKA, TKA assisted by the 3D printing osteotomy navigation template had such advantages as shorter operation time, less postoperative blood loss, and well postoperative recovery.
ObjectiveTo investigate the effect of body mass index (BMI) on the short- and medium-term effectiveness of unicompartmental knee arthroplasty (UKA) in the treatment of anterior medial compartmental osteoarthritis of knee joint.MethodsThe clinical data of 55 patients (61 knees) with anterior medial compartmental osteoarthritis of knee joint treated with minimally invasive UKA between May 2014 and May 2019 were retrospectively analyzed. According to BMI, the patients were divided into 3 groups: normal body mass group [group A, BMI 18.50-24.99 kg/m2, 23 cases (25 knees)], overweight group [group B, BMI 25.00-29.99 kg/m2, 23 cases (25 knees)], obesity group [group C, BMI 30.00-39.99 kg/m2, 9 cases (11 knees)]. There was no significant difference in gender, age, sides, disease duration, and preoperative American Special Surgery Hospital (HSS) score, pain visual analogue scale (VAS) score, and knee range of motion (ROM) among 3 groups (P>0.05). The operation time, intraoperative dominant blood loss, and the postoperative decreased amount of hemoglobin at 1 week were recorded and compared among 3 groups. The HSS score, VAS score, and ROM were used to evaluate the knee function and pain improvement.ResultsThere was no significant difference in the operation time, the intraoperative dominant blood loss, and the postoperative decreased amount of hemoglobin at 1 week among 3 groups (P>0.05). All the 55 patients were followed up 5-60 months, with an average of 24 months. No complication such as infection, fat embolism, or deep venous thrombosis of lower extremity occurred after operation. The anteroposterior and lateral X-ray films of the knee joint showed that no dislocation or loosening of the prosthesis occurred and the position of the prosthesis was good. At last follow-up, the HSS score, VAS score, and ROM of the 3 groups were significantly improved when compared with preoperative ones (P<0.05); but there was no significant difference among 3 groups (P>0.05).ConclusionFor obese and overweight patients with anterior medial compartmental osteoarthritis of the knee joint, the use of minimally invasive UKA can achieve satisfactory short- and medium-term effectiveness, and the long-term effectiveness needs further follow-up.
This article introduces the basic principles of finite element analysis in biomechanics, focusing on the basic principles of a variety of finite element analysis software, and their respective characteristics. In addition, it also describes the basic stress analysis of UGNX6.0 NASTRAN analysis for artificial knee process, i.e. the choice of the type, material definition, the set of constants, finite element mesh division and the finite element results of the analysis. Finite element analysis and evaluation of the design of personalized artificial knee were carried out, so that the rationality of the geometric design of the structure of the experimental design of artificial knee has been verified.