Prótesis de pivote medial y ultra-congruente: satisfacción y resultados clínicos. Serie de casos / Medial and ultra-congruent pivot designed prosthesis: satisfaction and clinical results. case series

Introducción La artroplastia total de rodilla es un procedimiento exitoso que mejora significativamente la calidad de vida de los pacientes disminuyendo el dolor e incrementando su capacidad funcional. Sin embargo, la literatura reporta hasta 25% de pacientes insatisfechos. El objetivo de este estudio es presentar los resultados clínicos y la satisfacción de un grupo de pacientes operados con implantes de tipo pivote medial y ultra-congruente. Materiales y métodos Se realizó un estudio observacional retrospectivo. Se revisaron las historias clínicas de todos los pacientes operados con los sistemas mencionados con mínimo 12 meses post-operatorios. Se analizaron resultados de 100 rodillas (96 pacientes) que completaron los cuestionarios, con una media de seguimiento de 33.5 meses. Se aplicaron los cuestionarios KSS, KOOS y WOMAC. Se estudiaron diferencias en dolor y función entre la etapa pre-operatoria y el último seguimiento. Se analizó la satisfacción de los pacientes con respecto al dolor y la capacidad funcional. Se evaluaron complicaciones presentadas. Resultados Todos los criterios presentaron una mejora estadísticamente significativa entre la etapa pre-operatoria y el último seguimiento. 97% de los pacientes reportaron estar satisfechos con los resultados. Las medias de los cuestionarios fueron entre 83.97 y 95.3. Se presentó 1 caso de revisión por infección peri-protésica. Discusión Las prótesis de pivote medial y ultra-congruente constituyen opciones eficaces y seguras para el tratamiento de artrosis de rodilla. Es necesario realizar estudios prospectivos y comparativos que generen evidencia de más alto nivel para confirmar los beneficios de estos diseños.

Background Total knee arthroplasty is a successful procedure that improves patient quality of life by reducing pain and increasing their functional capacity. However, literature reports up to 25% dissatisfaction in patients. The objective of the study is to present the clinical results and satisfaction of a group of patients operated on using ultra-congruent medial pivot-type implants. Methods A retrospective observational study was carried out. The medical records of all the patients who underwent knee arthroplasty surgery with a specific system were reviewed, including patients with a minimum of 12 months follow up. An analysis was performed on the results of 100 knees (96 patients) that had completed questionnaires. There was a mean follow-up of 33.5 months. The KSS, KOOS, and WOMAC questionnaires were used. Differences in pain and function between the pre-surgical stage and the last follow-up were studied. An analysis was made on patient satisfaction with regard to pain and functional capacity. Specific complications were evaluated. Results All evaluation criteria showed a statistically significant improvement between the pre-surgical stage and the last follow-up. Almost all (97%) of patients reported being satisfied with the results. The means of the questionnaires were between 83.97 and 95.3. One case of revision due to peri-prosthetic infection was presented. Discussion Medial pivot and ultra-congruent prostheses designs are effective and safe options for the treatment of osteoarthritis of the knee. Prospective and comparative studies that generate higher level evidence are necessary to confirm the benefits of these designs.

Application of personalized osteotomy guide plate in medial pivot knee prosthesis replacement based on MRI and three-dimensional CT / 中国组织工程研究

BACKGROUND: Personalized positioning guide plate based on three-dimensional CT data can improve the accuracy of posterior-stabilized prosthesis joint replacement, but bone structure reconstruction based on three-dimensional CT scan data ignores the thickness of distal femoral articular cartilage, which will affect the use of personalized osteotomy guide plate and the clinical effect of total knee arthroplasty. OBJECTIVE: To investigate the safety, accuracy and early clinical efficacy of three-dimensional printed screw positioning guide based on MRI and three-dimensional CT assisted medial pivot-total knee arthroplasty in the treatment of osteoarthritis. METHODS: A total of 110 patients with knee osteoarthritis admitted to Department of Orthopedics, Nanjing Hospital Affiliated to Nanjing Medical University from February 2018 to April 2019 were selected. All patients received medial pivot-total knee arthroplasty, and were randomly assigned to two groups. The 58 patients in the experimental group completed knee osteotomy with the assistance of personalized osteotomy guide plate based on MRI and three-dimensional CT. The 52 patients in the control group completed knee osteotomy with the traditional intramedullary and extramedullary positioning methods. The operation time and intraoperative blood loss of the two groups were recorded. Postoperative follow-up was conducted to review the X-ray films. KSS score of knee function and the visual analogue scale score were evaluated. RESULTS AND CONCLUSION: (1) 110 patients were followed up for 6-10 months without serious postoperative complications. (2) The operation time and intraoperative blood loss in the experimental group were less than those in the control group (P 0. 05). (5) The results showed that the personalized osteotomy guide plate assisted internal axial knee prosthesis replacement based on MRI and three-dimensional CT could effectively improve the accuracy of prosthesis placement and shorten the operation time. The method was safe and feasible, and the early clinical effect was satisfactory.

Total Knee Arthroplasty Using a Posterior Cruciate Ligament Sacrificing Medial Pivot Knee: Minimum 5-year Follow-up Results

PURPOSE: To evaluate minimum 5-year follow-up clinical and radiological results of total knee arthroplasty (TKA) using a posterior cruciate ligament sacrificing (PS), non-substituting Advance Medial Pivot Knee. MATERIALS AND METHODS: One hundred and twenty knees in 80 patients who could be followed up for more than 5 years after TKA using the PS Advance Medial Pivot Knee were evaluated retrospectively. The evaluations included the preoperative and postoperative range of motion (ROM), tibiofemoral angle, Knee Society (KS) knee and function scores, and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. The Kaplan-Meier method was used for survival analysis. RESULTS: The ROM increased from a preoperative mean flexion contracture of 7.6degrees and further flexion of 115.1degrees to a postoperative mean flexion contracture of 1.5degrees and further flexion of 120.5degrees. The tibiofemoral angle was changed from 4.6degrees varus preoperatively to 5.8degrees valgus postoperatively. The KS knee and function scores as well as WOMAC score significantly improved after surgery (p<0.05). Complications developed in 4 cases (3.3%): 2 cases of periprosthetic patellar fracture (1.7%) and 2 cases of aseptic loosening (1.7%). The seven-year survival rate was 98.1% in the Kaplan-Meier survival analysis. CONCLUSIONS: The minimum 5-year follow-up results of TKA using the PS Medial Pivot Knee were satisfactory.

Primary Total Knee Arthroplasty for Simple Distal Femoral Fractures in Elderly Patients with Knee Osteoarthritis

PURPOSE: Primary total knee arthroplasty (TKA) can be an alternative method for treating distal femoral fractures in elderly patients with knee osteoarthritis. The purpose of this study was to evaluate the clinical and radiographic results in patients with knee osteoarthritis who underwent TKA with the Medial Pivot prosthesis for distal femoral fractures. MATERIALS AND METHODS: Eight displaced distal femoral fractures in 8 patients were treated with TKA using the Medial Pivot prosthesis and internal fixation. The radiographic and clinical evaluations were performed using simple radiographs and Hospital for Special Surgery (HSS) knee scores during a mean follow-up period of 49 months. RESULTS: All fractures united and the mean time to radiographic union was 15 weeks. The mean range of motion of the knee joint was 114.3degrees and the mean HSS knee score was 85.1 at the final follow-up. CONCLUSIONS: Based on the radiographic and clinical results, TKA with internal fixation can be considered as an option for the treatment of simple distal femoral fractures in elderly patients who have advanced osteoarthritis of the knee with appropriate bone stock.

A Comparison of the Short-term Results between the PCL Sacrificing Medial Pivot Knee and Nexgen(R) LPS Total Knee Arthroplasty

PURPOSE: We wanted to compare the clinical and radiological results after performing total knee arthroplasty (TKA) with the PCL sacrificing (PS) Medial Pivot Knee (MPK) and the Nexgen(R) LPS. MATERIALS AND METHODS: Seventy knees in 48 patients after TKA with the PS ADVANCE(R) MPK (group I) and 67 knees in 45 patients with the Nexgen(R) LPS (group II) were retrospectively evaluated. All the patients were followed up for more than 2 years. The evaluations included the preoperative and postoperative range of motion (ROM), the Knee Society (KS) scores, the tibiofemoral angle and the postoperative complications. RESULTS: For group I, the ROM increased from a mean flexion contracture of 6.3degrees and further flexion of 116.4degrees to 1.9degrees and 120.5degrees, respectively, and for group II, from 12.6degrees and 117.6degrees to 0.9degrees and 123.0degrees, respectively. For group I, the KS knee and function scores increased from 46 and 37 to 87 and 83, respectively, and for group II, from 50 and 48 to 87 and 83, respectively. For group I, the tibiofemoral angle changed from varus 4.0degrees to valgus 5.5degrees, respectively, and for group II, from varus 4.1degrees to valgus 5.3degrees, respectively. The complications were 2 knees (2.8%) with periprosthetic patellar fractures and 1 knee (1.4%) with a tibial component failure in group I, and 1 knee (1.5%) with early femoral component failure and 1 knee with arthrofibrosis (1.5%) in group II. CONCLUSION: The minimum 2-year follow-up results of PS MPK TKA were comparable to those of Nexgen(R) LPS TKA. However, we think that the MPK system has the advantage of more bony preservation at the femoral intercondylar notch area.

Total Knee Arthroplasty with PCL Substituting Medial Pivot Knee: Short-term Follow-up Results

PURPOSE: To evaluate minimum 2-year follow-up clinical and radiological results after total knee arthroplasty (TKA) with a posterior cruciate ligament (PCL) substituting (PS) Medial Pivot Knee. MATERIALS AND METHODS: Seventy knees in 48 patients, who could be followed up more than 2 years after TKA with PS Advance(R) Medial Pivot Knee from October 2004 to February 2006, were evaluated retrospectively. The evaluations included the preoperative and postoperative range of motion (ROM), tibiofemoral angle, Knee Society (KS) knee and function score and postoperative complications. RESULTS: The ROM increased from preoperative mean flexion contracture of 6.3degrees and further flexion of 116.4degrees to a postoperative mean flexion contracture of 1.9degrees and further flexion of 120.5degrees. The tibiofemoral angle changed from preoperative varus 4degrees to postoperative valgus 5.5degrees. The KS knee and function score improved from 46 and 37 before surgery to 87 and 83 after surgery, respectively (p<0.05). The complications were 2 cases of periprosthetic patellar fracture and 1 case of early failure of the tibial component. CONCLUSION: The minimum 2 year follow-up results after TKA with PS Medial Pivot Knee were satisfactory.

Cruciate Retaining Medial Pivot Knee / 대한정형외과학회잡지

Purpose: To analyze the clinical and radiographic results of patients who underwent total knee arthroplasty with a posterior cruciate retaining medial pivot knee, and to identify the technical aspects in preserving the posterior cruciate ligament. Materials and Methods: From March 2002 to Dec 2003, 40 total knee arthroplasties with a cruciate retaining medial pivot knee were implanted in 28 cases. The average follow-up period was 2.8 years (range, 2 to 3.7 years). The clinical and radiographic results were evaluated using the clinical and roentgenographic evaluation and scoring system of the American Knee Society. Results: The average flexion contracture before surgery was 5.4degrees, which improved to 0.6degrees at the last follow-up. The average preoperative knee flexion was 126.1degrees and 126.6degrees at the last follow-up. The average knee score improved from 60 points preoperatively to 94.8 points postoperatively, and the average functional score improved from 55.3 points to 87.0 points at the final evaluation. The average post operative alpha, beta, gamma and delta angles were 95.1degrees, 91.1degrees, 3.6degrees and 84.0degrees, respectively. There were no postoperative complications. Conclusion: The short term clinical results in patients who had undergone total knee arthroplasty with a cruciate retaining medial pivot knee was acceptable.