META analysis of mobile bearing and fixed bearing unicondyle replacement for medial knee osteoarthritis / 中国骨伤

OBJECTIVE@#To evaluate of the clinical effects of mobile-bearing(MB) and fixed-bearing(FB) unicompartmental knee arthroplasty(UKA) in the treatment of knee osteoarthritis by Meta-analysis.@*METHODS@#The literature on FB UKA and MB UKA in the treatment of knee osteoarthritis in PubMed, CNKI, Wanfang, Cochrane and EMBASE database were searched by computer from January 2000 to April 2020. According to the inclusion and exclusion criteria, two authors were selected independently and the selected literature was evaluated for quality.After literature data were extracted, Review Manager 5.3 software was used to analyze knee function score, postoperative activity, revision rate, polyethylene wear rate, pad dislocation, aseptic loosening, postoperative pain, knee arthritis progression, mechanical shaft alignment of lower limbs, and imaging clarity line respectively.@*RESULTS@#A total of 13 literatures were included in this meta-analysis, including 2 randomized controlled studies and 11 cohort studies. A total of 1 871 patients were included, including 913 in FB UKA group and 958 in MB UKA group. Meta analysis results showed that:postoperative knee joint function score[MD=-0.84, 95%CI(-1.46, -0.21), P=0.008] and postoperative knee joint range of motion [MD=-1.51, 95%CI(-2.84, -0.18), P=0.03] in FB UKA group were better than those in MB UKA group. Compared with FB UKA group, MB UKA group had a higher lower limb mechanical axis alignment rate[OR=2.08, 95%CI(1.27, 3.39), P=0.003], and the wear rate of polyethylene [OR=0.11, 95%CI(0.01, 0.91), P=0.04] was lower. There were no differences between two groups in the renovation rate [OR=1.16, 95%CI(0.75, 1.80), P=0.50), liner dislocation rate[OR=3.78, 95%CI(0.93, 15.29), P=0.06], aseptic loosening [OR=2.11, 95%CI(0.81, 5.51), P=0.13], postoperative pain[OR=1.13, 95%CI(0.37, 3.43), P=0.83], osteoarthritis progression[OR=1.28, 95%CI(0.67, 2.47), P=0.46)and imaging radiolucent line[OR=1.62, 95%CI(0.09, 30.22), P=0.75].@*CONCLUSION@#FB UKA has a higher postoperative functional score and range of motion.MB UKA has more advantages in the correction of lower limb mechanical axis, and the wear rate of polyethylene is also lower. There was no significant difference between the two groups in revision rate, dislocation of the liner, aseptic loosening, postoperative pain, progression of osteoarthritis, and postoperative translucency.

Multivariate analysis of varus after Oxford unicompartmental knee arthroplasty / 北京大学学报(医学版)

OBJECTIVE@#To analyze the preoperative influencing factors of varus after Oxford unicompartmental knee arthroplasty.@*METHODS@#A total of 660 patients (767 knees) undergoing Oxford unicompartmental knee arthroplasty in adult joint reconstruction surgery department of Beijing Jishuitan Hospital from January 2018 to December 2019 were retrospectively analyzed. Inclusive criteria: diagnosis was osteoarthritis, single compartment lesions in the medial side of the knee; preoperative flexion deformity was less than 10°, active range of motion was greater than 90°; preoperative X-ray full-length images of both lower limbs showed less than 15° varus (Noyes method); anterior cruciate ligament was well functioned, The cartilage of lateral compartment of knee joint was intact.@*EXCLUSION CRITERIA@#combined with other inflammatory arthropathy; combined with extraarticular deformity; previous knee surgery history. The average age of the patients was (64.4±8.1) years, including 153 males and 497 females. The degree of post-operative varus was measured with Noyes method. The total patients were divided into varus group (Noyes≥3 °) and normal group (Noyes < 3 °). Gender, age, body mass index (BMI), range of motion (ROM), preoperative flexion deformity (FD), American Knee Society pain score (AKS) and American Knee Society function score (AKS function) were recorded. The standard anteroposterior and lateral X-ray films of knee joint and full-length lower extremity kinematic line films were taken by Sonialvision Safine Ⅱ (Shimadzu, Japan) multi-function digital tomography system. The image was measured by picture archiving and communication system (PACS). The following angles were measured preoperative Noyes angle, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA) and joint line converge angle (JLCA) were measured and analyzed.@*RESULTS@#Gender(P=0.346), operative side (P=0.619), age (P=0.746), BMI (P=0.142), preoperative ROM (P=0.102), preoperative knee pain score (P=0.131) and functional score (P=0.098) were not risk factors for postoperative varus. The influencing factors of postoperative varus were preoperative MPTA < 84 ° (P= 0.018, OR= 3.712, 95%CI: 1.250-11.027), preoperative Noyes > 5°(P=0.000, OR= 3.105, 95%CI: 1.835-5.254), preoperative FD > 5° (P= 0.001, OR=1.976, 95%CI: 1.326-3.234). Pre-operative LDFA (P=0.146) and preoperative JLCA (P= 0.709) had no significant effect on postoperative kinematic line.@*CONCLUSION@#Patients with severe preoperative varus, especially those with varus deformity mainly from the tibial side, and those with preoperative flexion deformity are more prone to get varus lower extremity kinematic line after Oxford unicompartmental knee arthroplasty.

Relationship of lower limb force line and the progression of lateral compartment arthritis after unicompartmental knee arthroplasty with mobile bearing / 中国组织工程研究

BACKGROUND: The long-term follow-up report shows that the progress of lateral compartment osteoarthritis is an important reason for the revision of unicompartmental knee arthroplasty, and the force line of lower limbs is considered to be an important factor leading to the progress of lateral compartment osteoarthritis after unicompartmental knee arthroplasty. OBJECTIVE: To explore the influence of lower limb force line on the progression of lateral compartment arthritis in unicompartmental knee arthroplasty with mobile bearing. METHODS: From March 2014 to March 2017, a retrospective analysis was conducted in 84 patients who underwent unicompartmental knee arthroplasty in the Department of Arthrology, Foshan Hospital of Traditional Chinese Medicine. Kellgren-Lawrence X-ray grading was used to evaluate the osteoarthritis of the lateral compartment during the follow-up. According to whether osteoarthritis of the lateral compartment was more advanced than that of the operation during the last follow-up, it was divided into the advanced group and the non-advanced group. The force lines of the lower limbs, such as hip-knee-ankle angle and Kennedy area distribution of the mechanical axis of the lower limbs, were compared between the two groups. Simultaneously, the knee joint function of the two groups was compared by the Hospital for Special Surgery knee score, visual analogue scale score of the knee joint, and motion range of the knee. The relationship between the changes of lower extremity force lines and the progress of lateral compartment arthritis was analyzed. RESULTS AND CONCLUSION: (1) All patients were followed up for 36-72 months, and no complications such as infection, poor wound healing, periprosthetic fracture, polyethylene gasket dislocation occurred. (2) Among the 84 patients, 27 cases were in the advanced group and 57 cases were in the non-advanced group. Significant differences in Hospital for Special Surgery knee score and visual analogue scale score were detected at the last follow-up between the advanced group and the non-advanced group (P 0.05). (3) At the last follow-up, the average hip-knee-ankle angle in the advanced group was (-1.02±3.13)°, while that in the non-advanced group was (3.94±1.56)°. The difference between the two groups was statistically significant (P < 0.05). Meanwhile, there was a significant difference in hip-knee-ankle angle between the last follow-up and the preoperation between the two groups (P < 0.05). (4) The regional distribution of lower limb mechanical axis Kennedy was compared between the two groups at the last follow-up, and the difference was statistically significant (P < 0.05). The postoperative lower limb force lines were mostly located in zone 3 and C in the advanced group, and mostly located in zone 2 in the non-advanced group. (5) Good lower limb alignment is the key factor affecting the clinical efficacy after unicompartmental knee arthroplasty with mobile bearing. Average varus angle of mechanical axis was approximately 3.94° in patients with well-functioning unicompartmental knee arthroplasty at follow-up, whereas patients for progression of osteoarthritis were in more valgus (mean 1.02° of valgus).

Mid-Term Results of Oxford Medial Unicompartmental Knee Arthroplasty in Young Asian Patients Less than 60 Years of Age: A Minimum 5-Year Follow-up

PURPOSE: The purpose of this study was to evaluate the efficacy of unicompartmental knee arthroplasty (UKA) in young active Asian patients by analyzing clinical outcomes, complications and survival rates. MATERIALS AND METHODS: Eighty-two knees were evaluated with a minimum follow-up of 5 years after Oxford phase 3 UKA in patients less than 60 years of age at the time of surgery. Their mean age was 54.7 years (range, 44 to 59 years). The mean follow-up period was 8.9 years (range, 5.3 to 12 years). Kaplan–Meier survivorship analysis was used to estimate implant survival. RESULTS: Including 3 bearing dislocations, 1 medial tibial collapse and 1 lateral osteoarthritis, the total complication rate was 6.1% (5/82). Of the 3 cases of bearing dislocation, 2 cases were resolved by replacing with a thicker bearing and 1 case was converted to total knee arthroplasty (TKA) due to repeated dislocation. The two knees with a medial tibial collapse and a lateral osteoarthritis were converted to TKA. The 10-year cumulative survival rate using Kaplan-Meier survival method was 94.7% (95% confidence interval: 88.7%–100%). CONCLUSIONS: Oxford medial UKA was reliable and effective in young active Asian patients providing good clinical results and survival rate in the mid-term follow-up.

MOBILE- VS. FIXED-BEARING TOTAL KNEE ARTHROPLASTY / Мэс засал

Introduction: The theory that usingmobile bearing (MB) design for total kneereplacementsurgeries can reduce the riskof tibial component loosening compared tofixed-bearing (FB) designs is still unclear.Arthroplastic surgeries developed rapidlywithin recent 10 years, but there is no similarstudy performed yet. This randomized studyinvestigated the impact of prosthesis design toloosening of components at 2 years for totalknee replacement surgeries.Materials and Methods: 479 patientswho underwent total knee arthroplastyin FirstCentral Hospital of Mongolia were allocated toeither FB or MB tibialarticulation.We comparedour results to similar studies which performedabroad due to there is no such a studyperformed before in Mongolia.Results: There is no significant differenceby age, sex, weight, height, body mass index,operation side (right or left) in both groups.Pre- and postoperative range of motionwasalmostsame for MB and FB groups.Butloosening complication was higher for the FBgroup (1.16%) than MB group (0%).Conclusion: Using MB design for total kneearthroplasty has less loosening complicationthan using FB design in Mongolians. Bonemineral density (dual energy absorptiometry)and radiostereometric analysis are necessaryfor widening studies in field of total kneereplacement surgeries in the future.

Short-Term Results of Total Knee Arthroplasty with Anterior-Posterior Glide LCS Mobile-Bearing System

PURPOSE: To evaluate the clinical and radiological results of total knee arthroplasty (TKA) using the anterior-posterior glide (APG) low contact stress (LCS) mobile-bearing system. MATERIALS AND METHODS: We evaluated 130 knees in 117 patients who had undergone TKA with APG LCS mobile-bearing system between September 2005 and July 2007 and could be followed over 5 years. The mean follow-up period was 68 months. The clinical and radiological results were evaluated using the American Knee Society Scoring System, Oxford knee score and the American Knee Society Roentgenographic Evaluation and Scoring System. And we analyzed short-term postoperative complications. RESULTS: The average range of motion of the knee joint was 107.9degrees (range, 70degrees to 135degrees) preoperatively and 125.2degrees (range, 90degrees to 135degrees) at the last follow-up. The average knee and functional scores were improved from 39.1 and 42.0 to 71.2 and 75.6, respectively, between the preoperative and last follow-up evaluation. The Oxford knee score was decreased from 42.9 preoperatively to 23.1 at the last follow-up. The femoro-tibial angle (anatomical axis) changed from 10.1degrees varus preoperatively to 3.3degrees valgus at the last follow-up. Radiolucency was observed in 14% of all cases. There were 1 case of traumatic dislocation of the polyethylene liner, 1 case of aseptic loosening and 6 cases of posterior instability because of posterior cruciate ligament (PCL) insufficiency. CONCLUSIONS: TKA with APG LCS mobile-bearing system demonstrated relatively good short-term clinical and radiological results. However, further considerations for posterior instability associated with PCL insufficiency are needed.

Comparison of Mobile-Bearing and Fixed-Bearing Designs in High Flexion Total Knee Arthroplasty: Using a Navigation System

PURPOSE: We compared and analyzed the short term results of high flexion total knee arthroplasty (TKA) with mobile-bearing and fixed bearing designs. MATERIALS AND METHODS: We studied 32 patients that had undergone TKA with LPS-Flex Mobile and 34 patients with LPS-Flex Fixed using an electromagnetic navigation system between January 2010 and June 2010, and were followed up for at least 1 year. RESULTS: Knee Society Functional Score (KSFS) and Knee Society Knee Score (KSKS) of the mobile-bearing group were 94.5 and 93.8 points, respectively, and were 48.2 and 45.3 points preoperatively, whereas those of the fixed-bearing group were 95.1 and 94.2 points, respectively, and were 49.5 and 46.9 points preoperatively. Postoperative mechanical axis deviation and implant position of the femoral and tibial component both on the coronal and sigittal planes showed no significant differences between the two groups. Range of motion (ROM) and maximal flexion angle (MFA) of the knee joint also showed no significant differences between the two groups. The possibility of crossed-legged sitting and kneeling position also showed no significant differences between the two groups. CONCLUSIONS: Clinical and radiologic parameters, ROM and MFA of knee joints showed no significant differences in both the groups, but long term follow-up results may be necessary, including survival rate.

Short-term Follow-up of Posterior Cruciate Ligament-sacrificed Total Knee Arthroplasty Using a Mobile Polyethylene Insert: Navigation-aided Technique

PURPOSE: Recently, a mobile ultracongruent polyethylene insert was used to increase joint stability in the posterior cruciate ligament sacrificed total knee arthroplasty with non-posted mobile bearing. However, as yet there have been no reports about this implant. In this study, the clinical and radiological results of surgery using the implant were analyzed through a navigation system. MATERIALS AND METHODS: The subjects included 95 cases of 70 patients to whom the rotating tibial implant was applied after posterior cruciate ligament resection among the patients who underwent total knee arthroplasty from September 2006 to December 2008. The follow-up duration was at least 24 months, and 40 months on average. For clinical evaluation, the knee score and functional scores were measured preoperatively and at the time of final follow-up. With reference to a 5 mm joint line change measurement recorded by the navigation system, which can affect the clinical result, the comparison and evaluation were performed by dividing the subjects into group I (5 mm). Radiological evaluation was performed by measuring the angle of the mechanical axis of the lower extremities and the patella tilting angle preoperatively and at the time of final follow-up using plain radiographs. RESULTS: Seventy subjects (95 cases) were followed up for at least 24 months. According to the clinical results, the mean KSS knee score improved from a preoperative score of 43.4 to a final follow-up score of 90.6 (p<0.0001). In addition, the mean functional score improved from a preoperative score of 51 to a final follow-up score of 88.4 (p<0.0001). Finally, the mean joint line change, which can affect the clinical result, was 5.82 mm, ranging from -1 to 12 mm. The clinical and radiological evaluations were performed by dividing the subjects into two groups in relation to the reference value of 5 mm, but no significant difference was found. The mechanical axis angles of the lower extremities improved from the preoperative value of varus 10.01degrees to the final follow-up value of varus 1.89degrees, and the difference was significant (p<0.0001). The mean patella tilting angles were 8.8degrees and 9.3degrees, respectively, at the time before the operation and after the final follow-up; this difference was not significant (p=0.89). CONCLUSION: Good clinical and radiological results were observed after at least two years of follow-up subsequent to total knee arthroplasty, in which a rotating ultracongruent polyethylene insert was applied after posterior cruciate ligament resection using a navigation system.

Comparison of the Mobile-bearing and Fixed-bearing Designs for High Flexion Total Knee Arthroplasty

PURPOSE: We compared and analyzed the follow-up results of high flexion total knee arthroplasty (TKA) with using the mobile-bearing and fixed-bearing designs. MATERIALS AND METHODS: We studied 130 patients who had undergone high-flexion TKA from December 2003 to December 2007 and who were followed up for at least 2 years. Of all the 130 patients, 65 patients had undergone TKA using a mobile-bearing design, and the other 65 patients had undergone TKA using the fixed-bearing design. RESULTS: The post-operative Knee Society Knee Score (KSKS) and Knee Society Functional Score (KSFS) of the mobile-bearing group were 95.6 and 96.1 points, which were 53.2 and 49.7 points, respectively, preoperatively, and the post-operative KSKS and KSFS of the fixed-bearing group were 94.5 and 95.1 points, which were 54.1 and 50.9 points, respectively, preoperatively. The range of motion (ROM) and maximal flexion angle (MFA) of the knee joints of the mobile-bearing group were 129.1degrees and 131.4degrees, which were 122.3degrees and 125.8degrees, respectively, preoperatively, and those of the fixed-bearing group were 128.3degrees and 129.3degrees, which were 122.2degrees and 123.9degrees, respectively, preoperatively. There were no significant differences between the two groups. Crossed-legged sitting and attaining a kneeling position also showed no significant differences between the two groups, but the mobile-bearing group could easily take a crossed-legged sitting position. CONCLUSION: The clinical parameters and the ROM and MFA of the knee joint showed no significant differences between both groups, but the mobile-bearing group felt more comfortable in the crossed-legged sitting position.

Short Term Results of Cruciate Retaining TypeMobile Bearing Total Knee Arthroplasty: Using a Navigation System

PURPOSE: We wanted to report the minimum 3 year follow-up clinical results of the patients who underwent navigation guided cruciate retaining mobile bearing total knee arthroplasty and to evaluate the radiological results for a consecutive series of patients. MATERIALS AND METHODS: Cruciate retaining mobile bearing total knee arthroplasties with using a navigation system were performed for 54 knees. The mean patient age was 65 years old (range: 51~76 years). The mean follow up period was 44 months (range: 36~61 months). The Knee Society Score (KSS) and range of motion (ROM) were evaluated for the preoperative and postoperative clinical assessments. We evaluated the alignment and the position of the implants by using plane radiographs for the radiological assessment, and we investigated the wear and loosening of implants in the same manner at the last follow-up exam. RESULTS: The knee score improved from 38 to 91 (p=0.001) and the functional score improved from 46 to 92 (p=0.001). The mean range of motion was also improved postoperatively. The radiological results of the coronal axis alignment of the lower extremity and the implant position were satisfactory in 98% of the cases. Periprostheic osteolysis occurred in 4 cases, but there were no clinically significant osteolysis seen on the follow-up radiographs. CONCLUSION: Soft tissue balancing and the accuracy of implantation are necessary when performing cruciate retaining mobile bearing total knee arthroplasty. For this type of implant, navigation is useful tool to perform total knee arthorplasty for insuring the accuracy of the surgical procedure.

Comparision between Mobile Bearing and Fixed Bearing T.K.A. in the Same Patient / 대한정형외과학회잡지

PURPOSE: To evaluate the radiological and clinical results including the patient's satisfaction after total knee arthroplasty (TKA) using two differently designed system for both knees in the same patient. MATERIALS AND METHODS: From January 2002 to January 2003, thirty-two bilateral TKAs were prospectively performed using two differently designed systems. One side TKA was performed using a mobile bearing (PFC RP, Dupey) system, and the other side was performed using a fixed bearing system (PFC, Dupey). All 32 patients were followed up for an average of 51.4 months. The mean age of the study group was 67 years (range 54-75). The clinical results were evaluated from the Knee Score, WOMAC score for the patient's satisfaction and range of motion. Radiological analysis including the tibiofemoral angle was also carried out. An independent T-test was used for statistical analysis. RESULTS: The preoperative average knee score improved to 87.3 from 42.5 in the mobile bearing group and to 86 from 39 in the fixed bearing group respectively. The preoperative average WOMAC score decreased to 11.2 from 84.9 in the mobile bearing group and to 16 from 85.5 in the fixed bearing group. The average preoperative range of knee motion improved to 114.5degrees from 104.5degrees in the mobile bearing group and to 113.8degrees from 104.7degrees in the fixed bearing group. The average preoperative tibiofemoral angle improved to 5.3degrees valgus form 4.5degrees varus in the mobile bearing group and to 6degrees valgus from 3.8degrees varus in the fixed bearing group. The only result statistically significant was the WOMAC score (p<0.05). CONCLUSION: The two differently designed TKA system produce similar outcomes except for the subjective satisfaction in the mid-term clinical and radiological evaluation.

A Comparison of Mobile-bearing and Fixed-bearing Total Knee Arthroplasties in Osteoarthritic Patients

PURPOSE: To compare the early clinical and radiographic results including patient's satisfaction after total knee arth- roplasty(TKA) using a mobile bearing knee prosthesis with fixed-bearing device. MATERIALS AND METHODS: From February 2002 to March 2004, author performed 30 posterior cruciate-retaining mobile bearing TKA and 39 posterior cruciate-retaining fixed bearing TKA. Clinical results were evaluated with knee score, patient's satisfaction by WOMAC score and range of motion. Radiographic analysis including tibio-femoral angle was also done. RESULTS: 1) The average knee score improved from 41.9 to 88.6 in mobile bearing group and from 44.3 to 87.6 in fixed bearing group respectively. The improvement of functional score were similar that 49.7 in mobile bearing group, 50.2 in fixed bearing group. 2) The average WOMAC score improved from 85.2 to 12.5 in mobile bearing group and from 85.3 to 13.9 in fixed bearing group. 3) The average range of motion of knee improved from 106.2 to 120.5 in mobile bearing group and from 105.2 to 118.8 in fixed bearing group. 4) The average tibio-femoral angle improved from 5.0 varus to 5.7 valgus in mobile bearing group and from 5.6 varus to 5.7 valgus in fixed bearing group. 5) Two of mobile and one of fixed bearing group complained persistent knee pain and two of mobile and one of fixed bearing group complained giving way sensation. CONCLUSION: This study shows that no significant difference in ROM, function, subjective evaluation and radiologic analysis for patients between two groups after minimum two-year follow-up.

Mobile Bearing Subluxation after Unicompartmental Knee Arthroplasty Treated by Arthroscopy : A Case Report

A polyethylene mobile bearing subluxation is a very rare complication after mobile type unicompartmental knee arthroplasty (UKA). Of 436 cases which had been followed up for 1 year after UKA, we experienced 9 cases of bearing dislocation and a case of bearing subluxation. We treated a case of mobile bearing subluxation by arthroscopy. We achived stable reduction of the bearing using arthroscopic surgery and the patient was satisfied with the outcome. So we report a case of mobile bearing subluxation after UKA treated by arthroscopy.

Long Term Results of LCS Mobile Bearing Knee System in Total Knee Arthroplasty

PURPOSE: To evaluate the long-term (over 10 years) clinical and radiologic results of LCS (low contact stress, Depuy, USA) total knee arthroplasty (TKA) retrospectively. MATERIALS AND METHODS: Out of 57 cases who underwent TKA with LCS knee system between June 1994 and August 1995, 33 cases could be analysed clinically and radiographically. Clinical analysis was performed according to flexion contracture, ROM, Knee Society Clinical Rating System (KSCRS) and Hospital for Special Surgery (HSS) score system. Radiographic analysis was performed according to the roentgenographic evaluation criteria of American Knee Society. Complications and survival rate were evaluated. RESULTS: Average flexion contracture was improved from 10.0degrees preoperatively to 3.7degrees at final followup and average ROM was improved from 104.0degrees preoperatively to 115.3degrees at final follow-up (p<0.05). Average HSS score was improved from 49.5 preoperatively to 80.1 at final follow-up and average KSCRS score was also improved from 77.2 to 152.5. Average tibio-femoral angle was changed from 3.3degrees varus preoperatively to 3.5degrees valgus at final follow-up. There were 4 complications, including infection in two cases and fracture dislocation of polyethylene implant in two cases respectively. Ten year survival rate was 94.1 percent. CONCLUSION: LCS TKA showed excellent results and good survival rate at more than ten years followup. However, more cases should be necessary for statistic significance.

Comparison of the clinical results of fixed-bearing and mobile-bearing total knee arthroplasty / 中国矫形外科杂志

0.05) at preoperatively and postoperatively the total knee score,preoperatively and postoperatively pain score,preoperatively and postoperatively patient function score,and preoperatively and postoperatively Patellar score.The postoperative maximum flexion of the fixed-bearing group and the mobile-bearing group was 108??9.3? and 99.5??10.1? respectively.There was significant difference between the 2 groups for the postoperative maximum flexion (P0.05) at the femoral valgus angle,the tibial angle,the tibial slope angle,and preoperatively and postoperatively the patellar height (Install-Salvati ratio).[Conclusion]The short-term results of the fixed-bearing posterior stabilized prosthesis and the mobile-bearing prosthesis TKA were successful.There was no significance difference between the two groups for the total knee score,function score,pain score,patellar score and radiographic results.The postoperative maximum flexion in fixed-bearing group was higher than that in mobile-bearing group.

Clinical outcome of CR type mobile bearing knee prosthesis / 中国矫形外科杂志

[Objective]To evaluate the role of mobile bearing knee prosthesis in TKA and the clinical results.[Method]A total of 301 TKAs by using mobile bearing knee prosthesis were gotten average 48.7 months follow-up.HSS knee scores and X-ray films were to used to evaluate the results.[Result]The mean HSS score improved from 51.3 before operation to 91.3 after operation.The ROM improved from extension/flexion(-9.5?/64.3?)before operation to extension/flexion(0?/97.5?)after operation.The maximum varus/valgus(25?/15?)before operation were improved to the mean valgus 5.3?.Two cases of septic loosening and 2 cases of femoral fracture were found.[Conclusion]The CR type mobile bearing knee prosthesis not only had advantages in kinematics and wear experiments,but also had achived good clinical result.

LCS mobile bearing knee system in Total Knee Arthroplasty

PURPOSE: The results of total knee arthroplasties using LCS mobile bearing knee system were analysed clinically and radiologically. MATERIALS AND METHODS: 57 total knee arthroplasties using LCS mobile bearing knee system were per-formed from July, 1995 to Dec.2001. There were 44 female and 10 male patients, and mean age was 66.4 years (41 years to 78 years). There were 55 osteoarthritic knees, and 2 rheumatoid arthritic knees. The average follow up period is 5.4 years (2 years to 8.3 years). ROM, and HSS knee score were analysed to evaluate clinical results. The tibiofemoral angle and radiolucent line were analysed to evaluate radiologic results. RESULTS: The preoperative mean flexion contracture is 6.8 degree, further flexion is 93.8 degree and HSS knee score is 51.3. The postoperative mean flexion contracture, further flexion and HSS knee score are improved to 2.1 degree, 124.1 degree and 88.4 respectively at final follow up. The mean tibiofemoral angle was improved from varus 5.8 degree to valgus 5.0 degree. The radiolucent lines were found in 2 knees, but the sum of the widths of the radiolucent lines was less than 4mm respectively, and were not classified as loosening. There was 1 post-operative infection case. The infection was treated with arthroscopic irrigation, IV antibiotics and daily irrigation with super oxidized soft water. There was not polyethylene dislocation or failure. CONCLUSION: LCS mobile bearing knee system showed excellent or good results clinically & radiologi-cally in short term follow up. To evaluate the radiological results of the wear and loosening of total knee arthoplasties using LCS mobile bearing knee system, continuous observation and analysis under the con-dition which excludes the external factor are necessary.

Total Knee Arthroplasty using LCS Mobile Bearing System

PURPOSE: We evaluated the efficancy of low contact stress (LCS) system in total knee arthroplasty by analyzing clinical and radiological results. MATERIAL AND METHOD: Total knee arthroplasty was performed on 194 patients with 280 knees by the senior author between January 1995 and August 2002, using the LCS system. We used the Hospital for Special Surgery knee rating scale, the range of motion, and radiographic evaluation. RESULT: The knee score was increased from average 48.4 points preoperatively to 84.8 points postoperatively. The flexion contracture was decreased from average 9.4 degrees preoperatively to average 2.8 degrees postoperatively. The further flexion was increased from average 102.2 degrees preoperative]y to 123.7 degrees postoperatively. The femorotibial angle was increased from average 6.2 degrees varus preoperatively to average 6.3 degrees valgus postoperatively. There were 3 fractures of meniscal bearing, 10 superficial infection cases, 3 deep infection cases and 2 peroneal nerve palsy. CONCLUSION: We reported that good and excellent clinical results (95%) were obtained in the patients who had arthroplasties with the LCS mobile bearing system.

Medium Term Results of a Mobile Bearing Total Knee Replacement / 대한정형외과학회잡지

PURPOSE: The LCS (low contact stress) mobile bearing knee replacement has been used extensively. The purpose of this study was to report at least five-year clinical results of a primary total knee replacement performed with LCS mobile bearing design. MATERIALS AND METHODS: From January 1992 to October 1997, author performed 80 total knee arthroplasties in 59 patients with LCS mobile bearing knee replacement. At the final follow-up, one patient had died, and ten patients had been lost to follow-up. The patients were evaluated with HSS (Hospital for Special Surgery) knee rating system and radiographic analysis. RESULTS: The fifty-six knees in the forty-two patients were examined for final clinical and radiographic analysis at five to ten years. The average active range of knee flexion was from 5 degrees to 112 degrees preoperatively and 0 degrees to 123 degrees at the final follow-up evaluation. The average HSS score was 60.7 points preoperatively and 88.9 points at the final follow-up evaluation. Of the 56 knees, none had a dislocation of the mobile bearing prosthesis, one case had a traumatic periprosthetic fracture and four cases required reoperation, one for infection, one patellar revision for patellar polyethylene breakage, one rotating platform change to thicker one for posterior instability during flexion and one meniscal bearing change for medial meniscal bearing wear. There was no significant progressive periprosthetic osteolysis on follow-up radiographs. CONCLUSION: After five to ten years of follow-up, the LCS knee replacement was found to be performing well, with durable clinical and radiographic results.

Results of a Mobile Bearing Total Knee Replacement: Comparison of Retention and Sacrifice of the Posterior Cruciate Ligament

PURPOSE: The purpose of this study was to compare the results of posterior cruciate ligament retention and sacrificed total knee arthroplasties with mobile bearing design. MATERIALS AND METHODS: Between January 1992 and October 1997, the study consisted of two types of low contact stress(LCS) implants: a meniscal bearing implant(Group I) that retained the posterior crucaiate ligament(n=31), and a rotating platform implant(Group II) requiring sacrifice of this ligament(n=25). All patients were evaluated with pre-and postoperative range of motion and HSS(Hospital for Special Surgery)knee rating system and radiographic analysis at least five years following the knee replacement. RESULTS: The average active range of knee motion was 4 degrees-113 degrees (Group I), 5 degrees-109 degrees (Group II) preoperatively and 0 degrees-127 degrees (Group I), 0 degrees-118 degrees (Group II) at the final follow-up evaluation. The average HSS score was 61.7(Group I), 56.0(Group II) preoperatively and 90.1(Group I), 88.2(Group II) at the final follow-up evaluation. In group I, one patellar revision for patellar polyethylene breakage and one meniscal bearing change for medial meniscal bearing wear had been performed. In group II, one revision for infection and one rotating platform change had been performed for posterior instability during flexion. we had no dislocation of mobile bearing prosthesis, but 2 cases was required reoperation because of one traumatic periprosthetic fracture(Group 1) and one post. instability(Group 2). There was no significant progressive periprosthetic osteolysis on last follow-up radiographs in both groups. CONCLUSION: After five to ten years of follow-up, we found no signigicant difference between group I and II. However, it might be that subjective symptom is excellent in group I and surgical technique remains an important element of success with mobile bearing implants regardless of posterior cruciate ligament.