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.
【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 rotational mismatch of total kneereplacement with medial 1/3 of tibial tuberosity as bony landmark in osteoarthritic patients with varus or valgus deformity. Methods Axial images on computed tomography of 62 knees (including 55 varus deformities and 7 valgus deformities) in 32 Chinese osteoarthritic patients who had total knee arthroplasty were analyzed, compared with that of 10 healthy knees. On images of the distal femur, the angle between the lines of surgical epicondylar axis(SEA) and posterior condylar axis was measured as posterior condylar angle (PCA), and on images of the proximal tibia, a baseline for the anteriorposterior axis of each component was drawn based on the SEA for the femur and the medial 1/3 of the tibial tuberosity for the tibia. The angle between these lines (Angle α) was defined as therotational mismatch between the components when they were aligned to the anatomic landmarks of each bone. Results The sulcus of medial epicondyle of femur could be identified on CT images of over 80% osteoarthritic knees; the median value of PCA was +2.36°, with an individual variation of 0° to +7.5°. Angle α was +6.45±3.68°(range, 0° to +11.8°) in 10 healthy knees, which increased significantly to +10.85±10.47°(range, 0° to +28.1°)in 55 varus knees (P＜0.05), which also increased significantly to +11.6±7.3°(range, -6.5° to +26.8°) in 7 valgus knees (P＜ 0.05). Conclusion With the medial 1/3 of the tibial tuberosity as the rotational landmark for the tibial component, there was a tendency to align the tibial component in external rotational position relative to the femoral component in knees with normal alignment, the rotational mismatch increased in Chinese osteoarthritic knees with varus and valgus deformity.
ObjectiveTo compare the early clinical outcome of GenesisⅡ high-flexion versus standard prostheses in total knee arthroplasty (TKA), and evaluate whether high-flexion prostheses can improve the postoperative range of motion (ROM). MethodsBetween September 2007 and December 2011, 80 patients (85 knees) consecutively underwent posterior cruciate-sacrificing TKA with GenesisⅡ systems. Finally, we reviewed 60 patients (60 knees) including 32 knees in high-flexion group and 28 knees in standard group. The follow-up time was 2.7 years in average. The postoperative knee ROM and the rate of complication of the two groups were evaluated. ResultsThe mean postoperative knee ROM of 32 knees was 112.8° in the high-flexion group and was 108.9° in the standard group. The mean postoperative HSS score was 86.6 and 84.2, respectively. The postoperative knee ROM, hospital for special surgery (HSS) score and the rate of complication did not show significant difference between the two groups. ConclusionThe high-flexion prosthesis is no better than the ordinary prosthesis in terms of the range of motion. We need more mid to long-term studies to do further research.
Objective To discuss the recent advancement of total knee arthroplasty (TKA) in the aspects of prosthesis selection, and compare the cl inical effect of every kind of knee prostheses so as to provide more information for cl inical appl ication. Methods The l iterature concerning prosthesis selection was extensively reviewed, and the methods and data were analyzed and summarized. Results The major disputes consisted of posterior cruciate retained versus excised,fixed-bearing versus mobile-bearing, high-flex versus standard implants and patella resurfacing versus nonresurfacing for TKA. Every kind of knee prostheses displayed safety and effectiveness in early and medium term follow-up, no significant differences were found in cl inical results. Conclusion Prosthesis selection in TKA should be overall considerated, and the merits of every kind of prostheses should be judged with long-term follow-up results.