Comparisonof early joint amnesia degree after posterior cruciate-retaining and posterior stabilized total knee arthroplasty / 中国组织工程研究

BACKGROUND: Clinical long-term follow-up showed that there is no obvious difference in knee range of motion, 10-15 year prosthesis survival rate, and main clinical manifestations after replacement of posterior cruciate-retaining and posterior stabilized prostheses. However, the debate over the superiority and inferiority of the two knee prostheses remains. OBJECTIVE: To compare the differences of early functional recovery of patients with unilateral knee osteoarthritis after posterior cruciate-retaining and posterior stabilized prosthesis replacement. METHODS: A total of 60 patients with knee osteoarthritis admitted to the First Affiliated Hospital of Anhui Medical University from July 2018 to September 2019 were selected, including 13 males and 47 females, aged 46-83 years old. Of them, 30 patients received posterior cruciate-retaining prosthesis replacement, and 30 patients received posterior stabilized prosthesis replacement. At 3 months after operation and at the last follow-up, joint amnesia score, knee function HSS score, visual analogue scale score, and knee motion range were assessed. The study was approved by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University. RESULTS AND CONCLUSION: (1) Sixty patients were followed up for 5-16 months, and no complications such as periprosthetic infection, loosening, dislocation, or stiffness occurred during the follow-up. (2) At 3 months after surgery and at the last follow-up, joint amnesia score, HSS scores, visual analogue scores, and knee motion range were not significantly different between the two groups (P > 0.05). (3) The results showed that joint amnesia score was not significantly different in early stage after the posterior cruciate-retaining and posterior stabilized prosthesis replacement for unilateral knee osthoarthritis.

The Use of PS or CR Models is not Sufficient to Explain the Differences in the Results of Total Knee Arthroplasty. Study of Interactions.

Aim: The study of results of Total Knee Arthroplasty based exclusively on the use of models Posterior stabilized (PS) or Cruciate retaining (CR) may be insufficient if we do not analyse other factors. Our objective is to analyse the interaction of certain factors as age, sex, BMI, prior deformity and use of navigation on the follow-up. Materials and Methods: Multicenter study of 415 Total Knee Arthroplasty (TKA). In 298 cases, the CR model was implanted and the PS in 117. The results were evaluated with the scales WOMAC, AKS and SF-12 v2. The average age of the series was 71 years (SD 7.8). The mean BMI was 31.7 (SD 4). In 294 cases, the frontal deformity of the mechanical axis of the knee was greater than 3°, particularly varus. Surgical navigation was used in 38.5% of patients as a helper in the implant of arthroplasty. Results: PS implanted joints demonstrated better results in all subscales than CR implanted joints. However,the study of the interaction between type of technique and preoperative deformity, sex, age, and BMI, showed that prior deformity and BMI influenced more on results than the use of one model or another. Navigation improved the results in the three scales, although these cases started with lower scores. Conclusion: Analysis of results of TKAs based exclusively on the use of PS or CR models is insufficient. Characteristics of the patient, previous deformity and navigation aid influence more on the results than using one model or another.

High-Flexion Posterior-Stabilized Total Knee Prosthesis: Is It Worth the Hype?

High-flexion knee prosthesis was introduced with the aim of obtaining higher degree of flexion and good survivorship in patients with high functional demands or those requiring squatting, kneeling, etc., which is more common in Asians. Based on all the research and experience with this prosthesis, it was concluded that high flexion designs meet the need of deeper degrees of flexion in selected sets of patients only. Results were equal and comparable to the traditional standard posterior-stabilized total knee arthroplasty design and superior to it in terms of gaining more flexion and fulfilling activities, such as squatting, kneeling, and sitting cross-legged.

Evaluation of Postoperative Range of Motion and Functional Outcomes after Cruciate-Retaining and Posterior-Stabilized High-Flexion Total Knee Arthroplasty

PURPOSE: The purpose of this study was to compare postoperative range of motion and functional outcomes among patients who received high-flexion total knee arthroplasty using cruciate-retaining (CR-Flex) and posterior-stabilized (PS-Flex) type prostheses. MATERIALS AND METHODS: Among 127 patients (186 knees) who underwent high-flexion total knee arthroplasty between 2005 and 2007, 92 knees were placed in the CR-Flex group, and 94 knees were placed in the PS-Flex group. After two years of postoperative follow-up, clinical and radiographic data were reviewed. Postoperative non-weight-bearing range of knee motion, angle of flexion contracture and functional outcomes based on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) functional sub-scale were assessed and compared between the two groups. RESULTS: After the 2-year postoperative period, the mean range of motion was 131degrees in the CR-Flex group and 133degrees in the PS-Flex group. There were no significant differences in postoperative range of motion between the two groups. Only age at operation and preoperative range of motion were significantly associated with postoperative range of motion after high-flexion total knee arthroplasty. Postoperative functional outcomes based on the WOMAC functional sub-scale were slightly better in the CR-Flex group (9.2+/-9.1 points) than in the PS-Flex group (11.9+/-9.6 points); however, this difference was not statistically significant (p=non-significant). CONCLUSION: The retention or substitution of the posterior cruciate ligament does not affect postoperative range of motion (ROM) or functional outcomes, according to 2 years of postoperative follow-up of high-flexion total knee arthroplasty.

Outcome of Total Knee Arthroplasty with Retaining Patellar in Osteoarthritis / 中国康复理论与实践

@#Objective To analyze the outcome of total knee arthroplasty with retaining patellar in osteoarthritis.Methods 45 knee joints in osteoarthritis were performed operatively with posterior stabilized knee arthroplasty between January 2005 and June 2008. The series include 7 sides(males) and 38 sides(females). The mean age of patients was 65.7 years ranging from 52 to 79 years, and the data were analyzed by The Hospital for Special Surgery(HSS) score system. Results The follow-up period was averagely 25 months ranging from 8 to 51 months. According to HSS score system, 28 sides were rated as excellent（62.2%）, 12 sides as good（26.7%）, 4 fair（8.9%）and 1 poor（2.2%）, and the excellent-good rate was 88.9%. Conclusion Posterior stabilized knee arthroplasty with retaining patellar represents a simple and valuable treatment methodology for the most osteoarthritis of the knee joint.

Effect of Decreasing Tibial Posterior Slope on the Extension-Gap during PS-TKA

PURPOSE: To evaluate the effect of decreasing tibial slope on extension gap during posterior stabilized total knee arthroplasty. MATERIALS AND METHODS: One hundred and ten cases of total knee arthroplasty which were done with posterior stabilized implant were included and we divided those into Group I; having flexion contracture (n=35) and Group II; no flexion contracture (n=75), and from each group, we evaluated the relationship between degree of decreased angle of tibial slope and frequency of additional resection of distal femur which was done for compensating insufficient extension gap during total knee arthroplasty and compared frequencies of additional distal femoral resections between 2 parts having more and less degree of decreased angle of tibial slope. RESULTS: In Group I and II, tibial slope decrease were 8.7degrees, 7.4degrees (p=0.145) and frequencies of additional resection were 51.4%, 24% (p=0.005) in average. Comparing 2 parts having more and less degree of decreased angle of tibial slope in each Group, frequencies of additional resection were 44.4%, 58.8% (p=0.505) and 13.2%, 35.1% (p=0.032). CONCLUSION: During posterior stabilized total knee arthroplasty, especially having no preoperative flexion contracture, decreasing tibial slope can be considered as a factor influencing on extension gap by removing greater anterior bone and the estimation of predictable tibial slope decrease through preoperative radiologic findings can be helpful in creating equal flexion and extension gaps.

In Vivo Biomechanics Using Dual Orthogonal Fluoroscopy after Posterior Stabilized Total Knee Arthroplasty / 대한정형외과연구학회지

This study investigated the six degrees of freedom (DOF) kinematics and three-dimensional (3D) contact during kneeling after total knee replacement arthroplasty. A total of 16 South Korean female patients (22 knees) after posteriorly stabilized (PS) TKA (LPS-Flex) performed by a single surgeon were randomly recruited. The patients were imaged using a dual fluoroscopic technique while they were kneeling from initial to maximum flexion. The acquired images and 3D models were then used to recreate the in vivo pose of the components Patients flexed their knee, on average, from 107.3degrees to 128.0degrees during the kneeling activity. Changes in kinematics included proximal, medial, posterior translation and varus rotation. Articular contact moved posteriorly by 5.9 mm and 6.4 mm in the medial and lateral compartments, respectively. Contact also moved medially by 3.2 mm and 5.8 mm in the medial and lateral compartments. A decrease in articular contact was observed in both condyles, and lateral condylar lift-off increased with flexion (P=0.0001). The tibiofemoral and cam/post articular contact data acquired in this study further suggest that kneeling may be performed by patients after clinically successful PS TKA who feel comfortable with activity and are free of

Fracture of a Polyethylene Tibial Post in a Scorpio Posterior-Stabilized Knee Prosthesis

We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articulation. This is the first report of a polyethylene tibial post fracture of a Scorpio PS prosthesis.