Objective To investigate a modified robotized hydraulictensor for management of the ligament balance in the total knee arthroplasty. Methods The effect of the modified robotized hydraulic tensor on the mechanical behaviour of the ligament system balance in the total knee arthroplasty was analyzed andthe related information was obtained. Results The robotized hydraulic tensor acted as a tensorsensor system, which could assist the surgeon by providing thequantitative information to align the lower limb in extension, equalize the articular spaces in extension and flexion, balance the internal and external forces, and define the femoral component rotation, and by providing the information toplan the releasing of the soft tissues and the rotating of the femoral component. Conclusion The modified robotized hydraulic tensor can enable the surgeon to properly manage the ligament balance in the total knee arthroplasty.
Objective
To investigate the effect of lateral retinacular release on the clinical outcomes after total knee arthroplasty (TKA) without resurfacing of the patella.
Methods
A prospective randomized controlled study was performed on 132 patients with unilateral degenerative knee arthritis undergoing TKA bewteen October 2012 and October 2014, who met the selection criteria. During TKA, lateral retinacular release was used in 66 cases (trial group) and was not used in 66 cases (control group). Two patients were excluded from the study due to missing the follow-up in trial group. Four patients were excluded from the study due to lateral retinacular release in control group. Finally, 64 patients and 62 patients were included in the trial group and in the control group. There was no significant difference in gender, age, body mass index, side, disease duration, preoperative patellar morphology, grading of patellofemoral arthritis, grade of patellar cartilage degeneration, patellar malposition, patellar maltracking, patellar score, and Knee Society Score (KSS) between 2 groups (P>0.05). The operation time, postoperative drainage volume, hospitalization time, postoperative complications, and patient satisfaction were recorded. Postoperative anterior knee pain was assessed by visual analogue scale (VAS), and the knee joint function was evaluated by KSS score and patellar score. The femoral angle, tibial angle, femoral flexion angle, and tibial posterior slope angle were measured on the X-ray film for postoperative prosthetic alignment. The postoperative patellar tracking and patellar position, as well as the presence of osteolysis, prosthesis loosening, patellar fracture and patellar necrosis were observed.
Results
All patients were followed up for 24 months. There was no significant difference in operation time, postoperative drainage volume, hospitalization time, and patient satisfaction between 2 groups (P>0.05). The incidence of anterior knee pain in the trial group was better than that in the control group (P=0.033). KSS score and patellar score were significantly improved in both groups at 24 months after operation when compared with preoperative scores (P<0.05), but no significant difference was found between 2 groups (P>0.05). Complications included hematoma (2 cases in the trial group, and 1 case in the control group), mild wound dehiscence (2 cases in each group respectively), skin-edge necrosis (1 case in the trial group), and superficial wound infection (1 case in each group respectively), which were cured by conservative treatment. No patellar necrosis, patella fracture, or knee lateral pain occurred in 2 groups. There was no significant difference in complication rate between groups (P=0.392). Satisfactory implant alignment was observed in both groups during follow-up. There was no significant difference in femoral angle, tibial angle, femoral flexion angle, and tibial posterior slope angle between 2 groups (P>0.05). No radiolucent line at the bone-implant interface was seen around the tibial components and femoral components in both groups. The patellar maltracking was observed in 3 patients of the trial group and 5 patients of the control group, showing no significant difference (P=0.488). However, the incidence of patellar malposition in the trial group (18.8%) was significantly lower than that in the control group (35.5%) (χ2=0.173,P=0.034).
Conclusion
Lateral retinacular release during primary TKA without resurfacing of the patella can reduce postoperative knee pain without increasing complications.
【Abstract】 Objective To explore the flexibil ity and rel iabil ity of cementless total knee arthroplasty (TKA) without patellareplacement through a retrospective study of the mid-term therapeutic effect of the treatment of the patients. Methods FromJune 1997 to March 2000, a consecutive series of 152 (152 knees) cementless TKA performed in Hessing-Stiftung was studied. Among them, there were 63 males and 89 females, with 70 left knees and 82 right knees. Their ages ranged from 51 years to 72 years, with an average of 59 years. There were 146 cases of osteoarthritis and 6 cases of traumatic arthritis. The course of the disease lasted for 1.0 years to 3.5 years. The EFK prostheses of German Plus company were used in all the cases. The HSS score before the operation was 41.5 ± 12.3, and the average range of motion was 55o (ranging from 30o to 90o). Results Five patients underwent anterior knee pain, and the pain was released after the appropriate treatment. No deep infection happened in all cases. A total of 145 patients (145 knees) were followed up for 5 years to 8 years. The HSS score was 87.5 ± 8.2 at the end of the follow-up, showing significant difference (P lt; 0.05). The average range of motion was 95o (ranging from 90o to 110o). Partial radiolucencies occurred at the tibia side in 18knees 3 to 6 months after the operation. Among them, the width was less than 2 mm in 15 knees without symptom, and more than 2 mm in 3 knees. There were 2 of the 3 knees which were revised at the tibia side because of the aseptic loosing, while 1 patient had only mild pain in the knee during the follow-up, with no sign of loosing. Conclusion The mid-term effect of cementless TKA is satisfactory. The ingrowth of femur and tibial bones is rel iable. The early stage migration of the component is the main reason of loosing. Satisfying outcomes can also be achieved without patella replacement during TKA.
Objective To discuss shortterm effect of rotating hinge knee prosthesis. Methods From July 2002 to April 2005, 17 cases of severe knee joint deformity and instability received rotating hinge knee prosthesis for total knee arthroplasty. There were 8 males and 9 females, aging from 41 to 79 years. The left joints were involved in 10 cases and right joint in 7 cases. All patients were admitted because of pain. The course of disease was from 1 to 7 years. There were 10 cases of osteoarthritis，5 cases of rheumatoid arthritis，1 case of traumatic arthritis after operation of left femur fracture，and 1 case of traumatic arthritis with injury of anterior cruciate ligament, meniscus medialis and medial collateral ligament after operation of left fracture of tibial plateau. According to HSS(hospital for special surgery) scoring system，the preoperative score was 36 to 58 with an average of 48.6. The preoperative flexed motion range of articulation was 21° to 80° with an average of 57.4°. Results All patients were followed up from 7 months to 3 years with an average of 23.6 months. There were no complications of thrombogenesis of veins of lower extremity, pulmonary embolism, palsy of peroneal nerve, fracture, and breakage of extended knee structure. Infection occurred in 1 case at 3 months postoperatively，the prosthesis was dislodged，antibiotic-impregnated cement was filed with knee joint，twostage arthroplasty was expected. At the last follow-up,the HSS score was 78 to 98 with an average of 91.1 in 16 patients. The flexed motion range of articulation was 75° to 100° with an average of 852° at 2 weeks postoperatively. The flexed motionrange of articular was 85° to 123° with an average of 1083° at the last followup. There were significant differences in HSS score and motion range of articular between preoperation and thelast follow-up (P＜0.05). Conclusion The short-term outcome of rotating hinge knee prosthesis is good and a long term followup is necessary.
The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients’ walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427?0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Objective To review the advance in the researchand clinical application of the tibial rotational alignment technique in the total knee arthroplasty in China and abroad. Methods The recent literature concerned with the tibial rotational alignment technique in the totalknee arthroplasty was extensively reviewed and briefly summarized. Results According to the literature reviewed, the traditional tibial rotational references for the total knee arthroplasty were affected by many factors, so that the references were not accurate enough. There have been no unified references.ConclusionChoosing the range from the medial border of the tibial tubercle to the medial 1/3 of the tibial tubercle, decided by the degrees of the varus deformities and the valgus deformities, to determine the rotaional alignment of the tibial component will create an optimal tibiofemoral rotational alignment.
Objective To make a retrospective analysis on an early clinical outcome of total knee arthroplasty (TKA) for the knees with different degrees of flexion-contracture deformities. Methods Ninety-seven knees of 65 patients undergoing total knee arthroplasty with the Scorpio posterior-stabilized knee prosthesis from January 2000 to December 2003 were reviewed, including 51 osteoarthritis patients (74 knees) and 14 rheumatoid arthritis patients (23 knees). Thirtythree patients underwent unilateral TKA, and 32 patients underwent bilateral TKA. The average range of motion (ROM) before operation was 82.8°(range, 5-140°).According to the preoperative flexion-contracture degrees of the knees, these patients were divided into 2 groups, group A and group B. Group A consisted of the patients with flexioncontracture less than 20° (range, 0-15°), and group B consisted of the patients with flexion-contracture not less than 20° (range, 20-60°). In group A, the average flexion-contracture degree, ROM, KSS (knee society score), and function score were 10.7±8.0°, 104.6±20.0°, 29.1±18.0, and 32.6±20.7, respectively. But the corresponding data were much worse ingroup B than in group A, which were 28.2±7.8°, 60.8±26.6°, 12.1±13.2, and 26.8±18.1. All the operations were primary total knee arthroplasty, and they were performed by the same group of surgeons. The time for the prosthesis installed lasted for 25.6 minutes, and the average tourniquet time was 34.7 minutes. Three or four days after operation, the patients began the continuous passive motion (CPM) and active functional exercise of the knee.Results The patients were followed up for an average of 2 years and 7 months(range, 8 mon-3.5 yr). During the follow-up period, the average flexion-contracture degree, ROM, KSS, and function score in group A were 0.4±2.1°, 108.6±19.0°, 82.1±13.8, and 72.3±29.1, respectively; and the corresponding data in group B were 1.3±3.2°, 986±16.4°, 75.9±8.2, and 81.4±26.9, respectively. There was no significant difference between the 2 groups. No revision or deep infection was found. Conclusion The curative effect is mainly determined by the surgeon’s good operational skills, rich clinical experience, and familiarity with the prosthesis, and it is not influenced by severity of the knee flexioncontracture deformity. The knee ROM after TKA, which has a “toward middle ROM”phenomenon, is influenced by many clinical factors. It is very important for the patientto perform a functional exercise of the knee as early as possible after operation.
ObjectiveTo evaluate the effect of the surgeon’s handedness on the distribution of prosthesis during primary total knee arthroplasty (TKA).MethodsA retrospective analysis was performed on 86 patients (100 knees) with primary TKA completed by the same right-handed surgeon between December 2016 and December 2018, including 72 cases of single knee and 14 of bilateral knees. The patients were divided into dominant group (right side) and non-dominant group (left side) according to the operating position of the surgeon and each group had 50 knees. There was no significant difference in gender, age, body mass index, disease duration, clinical diagnosis, preoperative Hospital for Special Surgery (HSS) score, and other general data between the two groups (P>0.05). The operation time and complications were recorded in both groups. The function of knee was evaluated by HSS score. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle (mMPTA) were measured by using X-ray film of full-length lower extremity before TKA and at 2 weeks after TKA that were used to evaluate the coronal position of the prosthesis. Posterior distal femoral angle (PDFA) and posterior proximal tibial angle (PPTA) were measured by using lateral X-ray films at 3 months after operation that were used to evaluate the sagittal position of the prosthesis.ResultsThere was no significant difference in operation time between the two groups (t=?1.128, P=0.262). One case of posterior tibial artery thrombosis occurred in the dominant group, and 1 case of poor healing of the incision occurred in each of the dominant group and the non-dominant group. Patients in both groups were followed up 12-34 months with an average of 22.0 months. The HSS scores at last follow-up were 87.2±4.3 in the dominant group and 86.8±5.0 in the non-dominant group. There was no significant difference between the two groups (t=0.471, P=0.639). No complications such as periprosthetic infection, prosthetic loosening, or periprosthetic fracture occurred during follow-up. There was no significant difference in the HKA, mLDFA, and mMPTA between the two groups before and after operation (P>0.05). The differences in the incidence of sagittal femoral prosthesis malposition and PDFA between the two groups were significant (P<0.05); however, there was no significant difference in the PPTA, the rate of femoral prosthesis distributed in the neutral position, the incidence of over-flexed femoral prosthesis, and the incidence of anterior femoral notch (P>0.05).ConclusionThe surgeon’s handedness is one of the factors affecting the placement of the sagittal femoral prosthesis in primary TKA. The incidence of sagittal femoral prosthesis malposition could increase when the surgeon performs on the non-dominant side.
Objective To investigate the effect of body mass index (BMI) on the short-term effectiveness of high tibial osteotomy (HTO) in the treatment of varus knee arthritis. Methods The clinical data of 84 patients (84 knees) with varus knee arthritis treated with HTO between May 2016 and August 2020 were retrospectively analyzed. According to BMI, the patients were divided into normal group (32 patients in group A, BMI<25 kg/m2), overweight group (27 patients in group B, BMI>30 kg/m2), and obese group (25 patients in group C, BMI>30 kg/m2). The BMI of groups A, B, and C were (23.35±0.89), (26.65±1.03), and (32.05±1.47) kg/m2, respectively. There was no significant difference (P>0.05) in gender, age, surgical side, disease duration, and preoperative Hospital for Special Surgery (HSS) score, visual analogue scale (VAS) score, knee range of motion, and hip-knee-ankle angle (HKA) between groups. The operation time, intraoperative dominant blood loss, and the decrease of hemoglobin on the 3rd day after operation were recorded and compared between groups. The improvement of knee joint function and pain status were evaluated by knee joint HSS score, knee range of motion, and VAS score before and after operation, and measuring the HKA of patients on X-ray film. During the follow-up, the X-ray films of the knee joint were reexamined to observe the position of the internal fixator and the healing of osteotomy. Results All patients completed the operation successfully and were followed up 8-40 months (mean, 19.3 months). There was no significant difference in follow-up time, operation time, intraoperative dominant blood loss, and the decrease of hemoglobin on the 3rd day after operation between groups (P>0.05). No operative complications such as severe vascular or nerve injury occurred. After operation, deep venous thrombosis of lower extremities occurred in 1 case in groups A and B respectively, and fat liquefaction of surgical incision occurred in 2 cases in group C. There was no significant difference in the incidence of perioperative complications between groups (3.1% vs. 3.7% vs. 8.0%) (P=0.689). During the follow-up, there was no bone nonunion, plate fracture or loosening. At last follow-up, HSS score, VAS score, knee range of motion, and HKA significantly improved in the 3 groups when compared with those before operation (P<0.05), but there was no significant difference in the differences of the above indexes between groups before and after operation (P>0.05). Conclusion BMI does not affect the short-term effectiveness of HTO in the treatment of varus knee arthritis. HTO can be selected for overweight and obese patients after standard medical treatment is ineffective.
Objective To develop a neural network architecture based on deep learning to assist knee CT images automatic segmentation, and validate its accuracy. Methods A knee CT scans database was established, and the bony structure was manually annotated. A deep learning neural network architecture was developed independently, and the labeled database was used to train and test the neural network. Metrics of Dice coefficient, average surface distance (ASD), and Hausdorff distance (HD) were calculated to evaluate the accuracy of the neural network. The time of automatic segmentation and manual segmentation was compared. Five orthopedic experts were invited to score the automatic and manual segmentation results using Likert scale and the scores of the two methods were compared. Results The automatic segmentation achieved a high accuracy. The Dice coefficient, ASD, and HD of the femur were 0.953±0.037, (0.076±0.048) mm, and (3.101±0.726) mm, respectively; and those of the tibia were 0.950±0.092, (0.083±0.101) mm, and (2.984±0.740) mm, respectively. The time of automatic segmentation was significantly shorter than that of manual segmentation [(2.46±0.45) minutes vs. (64.73±17.07) minutes; t=36.474, P<0.001). The clinical scores of the femur were 4.3±0.3 in the automatic segmentation group and 4.4±0.2 in the manual segmentation group, and the scores of the tibia were 4.5±0.2 and 4.5±0.3, respectively. There was no significant difference between the two groups (t=1.753, P=0.085; t=0.318, P=0.752). Conclusion The automatic segmentation of knee CT images based on deep learning has high accuracy and can achieve rapid segmentation and three-dimensional reconstruction. This method will promote the development of new technology-assisted techniques in total knee arthroplasty.
