Both minimally invasive surgery(MIS) and computer-assisted surgery(CAS) in total knee arthroplasty have been scientifically linked with surgical benefits. However, the long-term results of these techniques are still controversial. Most surgeons assessed the surgical outcomes with regard to knee alignment and range of motion, but these factors may not reflect subjective variables, namely patient satisfaction To compare satisfaction and functional outcomes between two technical procedures in MIS total knee arthroplasty, namely computer-assisted MIS and conventional MIS procedure, operated on a sample group of patients after 10 years.Background
Purpose
Hard-on-hard bearings showed advantages of reduction of wear rates, osteolysis and aseptic loosening in total hip arthroplasty (THA). A new combination of ceramic-on-metal (COM) was developed to compensate the disadvantages of MOM and COC. COM showed good short-term results in vitro and in vivo studies. There was no report of stripe wear and metal ion level elevation. Our study was designed to evaluate the wear pattern of this bearing in early loosening THA. During January 2009 to December 2010, 121 primary THAs were performed at our institution by single-surgeon, using the same acetabular component and same uncemented femoral stem with a 32-mm modular head. All patients received the information of the bearing couples and made their own decision to choose one of the following bearings: COM, MOP and MOM. The functional outcomes (Harris Hip Score), Serum Co and Cr levels and survival rates were compared between groups at 5 years. The retrievals were tested by optical microscopy and Raman spectroscopy to evaluate the wear pattern in the cases those need revision.Background
Methods
Correct sizing of prostheses is a considerable factor regarding function and successful rate of total knee arthroplasty (TKA). Patient-specific guide (PSG), using CT preoperative planning for sizing, alignment and bone cutting, has been developed to improve the accuracy and reproducibility of TKA. The purpose of this study is comparing the accuracy of CT-based preoperative sizing in PSG with the conventional femoral sizing instrument. From January 2012 to December 2012, fifty-four patients underwent TKA with CT-based PSG. Preoperative sizing was compared to the component size measured intra-operatively by conventional anterior reference femoral sizing instrument. The actual sizes of implanted components were also recorded to analyze the accuracy of each measurement.Purpose
Methods
Rotational malalignment in total knee arthroplasty (TKA) may lead to several complications. Transepicondylar axis has been accepted for a reference of femoral rotation. In contrast, standard reference of tibial rotation remains controversial. Currently, two techniques are widely used, the anatomical landmarks technique and the range-of-movement (ROM) technique. Fifty-one patients underwent posterior-stabilized TKA with center-post self-align ROM technique for tibial component placement. Laurin view radiograph and computer tomography (CT) were used to assess the prosthetic position. The rotational mismatch between tibial and femoral components was 2.00° ± 0.34° (range, 0.1°-5.8°). All TKA showed a tibiofemoral mismatch within 10° (range, 0.1° −5.8°). Intraoperative evaluation of patellar tracking by no-thumb test and the Laurin view showed normal range in 90%. We concluded that tibial component placement with center-post self-align technique in PS-TKA can produce good patellar tracking with acceptable range of tibiofemoral mismatch.
Osteolysis is one of a major cause of failure that affect long term survival rate in THA. Hard-on-hard bearing surface were developed to reduce wear and osteolysis, such as ceramic-on-ceramic which is the lowest wear rate was introduced but it still has squeaking and ceramic fracture. Metal-on-metal bearing surface significantly reduce wear rate but it still release metal ion which affect local tissue reaction. Then ceramic-on-metal is another choice of bearing with combine the advantage of reduce wear rate, metal ion release, no stripe wear, no squeaking and no ceramic fracture. However after clinical use ALTRs may occur and disturb the longevity of THA. During January 2009 to December 2009 we performed 98 THR with the same femoral stem and acetabular cup with difference bearing which were 87 cases of metal on cross-linked PE, 8 cases of ceramic on metal and 5 cases of metal on metal. Routinely postoperative care were done with clinical evaluation, plain x-rays and Harris hip score. After 5 years follow up there are clinical problems in ceramic on metal THA with decrease clinical score and progressive osteolysis in radiographic finding in 2 cases then we investigated to find the cause of this problem and revise the components. We preformed magnetic resonance imaging and collect blood sample for ESR, CRP and Cobalt and Chromium level. We revised 2 cases of ceramic on metal THA, during surgery we collected tissue for bacterial and AFB and histopathology. All retrieval components were studied for wear pattern. First patient have thigh pain and progressive osteolysis after year 4th of follow up. She had normal ESR and CRP with high level of cobalt and chromium level. We revised both components and tissue histopathology showed metallosis with chronic inflammation. Another patient had failure due to ALTRs with mixed solid-cystic mass at trochanteric bursa but component is stable then only bearing surface were change. Wear pattern at femoral head was in weight bearing area with corresponding to apical center wear of metal liner. Our study showed that only in group of ceramic-on-metal THA that have 5 years follow up have early reoperation due to osteolysis and tissue reaction. We routinely stop to use this bearing since 2010. But we have small number of cases in our study to conclude that is bearing are not suitable for clinical usage.
