This paper aims to analyze the kinetics of the over-ground wheel-type body weight supporting system (BWS); tendency changes of low extremity joint moment (hip, knee, ankle), 3 axis accelerations of a trunk, cadence and gait velocity as weight bearing level changes. 15 subjects (11 males, 4 females, age:23.63.5, height:170.65.1cm, weight:69.0210.75kg) who had no history of surgery participated. 6 levels (0%, 10%, 20%, 30%, 40% and 50%) of BWS were given to subjects at self-selected gait velocity and kinetic data was calculated using a motion capture system, Vicon® (Vicon, UK).Objective
Method
In recent years, there has been an increase in hip joint replacement surgery using short bone-preserving femoral stem. However, there are very limited data on postoperative periprosthetic fractures after cementless fixation of these stem although the periprosthetic fracture is becoming a major concern following hip replacement surgery. The purpose of this study is to determine incidence of postoperative periprosthetic femoral fractures following hip arthroplasty using bone preserving short stem in a large multi-center series. We retrospectively reviewed 897 patients (1089 hips) who underwent primary total hip arthroplasty (THA) or bipolar hemiarthroplasty (BHA) during the same interval (2011–2016) in which any other cementless, short bone-preserving femoral stem was used at 7 institutions. During the study, 1008 THAs were performed and 81 BHAs were performed using 4 different short femoral prostheses. Average age was 57.4 years (range, 18 – 97 years) with male ratio of 49.7% (541/1089). Postoperative mean follow-up period was 1.9 years (range, 0.2 – 7.9 years).Introduction
Materials & Methods
Injection before total knee arthroplasty(TKA) is the one of the postoprative risk factors after TKA and Infection after TKA can result in disastrous consequences. When the duration between injection and TKA is longer than 6 months, the risk is no longer elevated. Evaluation of synovial WBC number in frozen section slide is needed to check the presence of infection in revision total knee arthroplasty. Currently many patients have a history of multiple intraarticular injection before the primary TKA. Purpose of this study is to evaluate the synovial WBC findings in primary TKA and compare between injection group and no injection group. Materials and Methods. The synovial specimen(suprapatella pouch and posterior capsule) of 68 primary total knee arthroplasty were evaluated by the pathologist and reported the number of the WBC in frozen section /5 separate high power fields(HPF) (500x).. Injection group were 37 cases and non -injection group were 31 cases. Preoperative CRP and ESR were recorded and followe-up duration was more than 2 years. Joint fluid was sent to be cultured and analysed. Results. WBC count in frozen section shoed was average 4 WBCs/HPF (range < 0∼ 25) in both specimen and the suprapatella specimen was 3 WBCs/HPW (range 0∼25) and posterior capsule specimen was 1 WBCs/HPF(range 0∼14). The WBC count of injection group was 8 (range, 0∼25) and that of no injection group was 1.2 cells (range 0∼12) (p<0.05). The WBC counts in joint fluid was average 240 cells/ml (range. 1∼300) in non injection group and 643 cells/ml(range, 50∼1000) (p<0.05). The duration from the intraarticular injection to index surgery was 9 months(range, 6 weeks∼ 7 momths). The number of injection and duration bwtween injection and operationto has no significant correlation with the WBC counts. Eight percentage of specimen showed more than 10 WBCs in injection group and these patients have been not infected after more than 24 moths after TKA. Conclusion. The WBC count of the synovium in priamry TKA with injection history for degenerative osteoarthritis is variable and we could not recommend the routine frozen section analysis in primary TKA who have a history of intraarticualr injection..
Use of a baseplate with a smaller diameter in reverse shoulder arthroplasty has been recommended, especially in patients with a small glenoid or insufficient bony stock due to severe glenoid wear. However, effect of a smaller baseplate on stability of the glenoid component has not been evaluated. The purpose of this study was to determine whether a smaller baseplate (25 mm) is beneficial to the initial primary stability of the glenoid component compared to that with a baseplate of a commonly used size (29 mm) by finite element analysis. Computed tomography (CT) scans of fourteen scapulae were acquired from cadavers with no apparent deformity or degenerative change. Glenoid diameter corresponding to the diameter of the inferior circle of glenoid was measured using a caliper and classified into the small and large glenoid groups based on 25mm diameter. CT slices were used to construct 3-dimensional models with Mimics (Materialise, Leuven, Belgium). A corresponding 3D Tornier Aequalis® Reversed Shoulder prosthesis model was generated by laser scanning (Rexcan 3D Laser Scanner, Solutionix, Seoul, Korea). Glenoid components with 25mm and 28mm diameter of the baseplate were implanted into the scapular of small and large glenoid group, respectively. Finite element models were constructed using Hypermesh 11.0 (Altair Engineering, Troy, MI, USA) and a reverse engineering program (Rapidform 3D Systems, Inc., Rock Hill, SC, USA). Abaqus 6.10 (Dassault Systemes, Waltham, MA) was used to simulate 30o, 60o, and 90o glenohumeral abduction in the scapular plane. Single axial loads of 686N (1 BW) at angles of 30o, 60o, and 90o abduction were applied to the center of the glenosphere parallel to the long axis of the humeral stem. Relative micromotion at the middle and inferior thirds bone–glenoid component interface, and distribution of bone stress under the glenoid component and around the screws were analyzed. Wilcoxon's rank-sum test was used for statistical comparison and p < 0.05 was considered as a minimum level of statistical significance.Background
Methods
The purpose of this study is to compare the mid-term outcomes between rotating platform(RP) and posterior cruciate substitute(PS) bearings in LCS-total knee arthroplasty (TKA). This is a prospective randomized matched-pairs case–control study of patients who underwent primary TKAs with a minimum 2 years follow-up. The inclusion criteria was degenerative arthritis, and exclusion criteria was arthritis other than degeneration, previous operations such as osteotomy, body mass index (BMI) over 30 kg/m2. The matching criteria were set as age, BMI, preoperative ROM, gender, and the Knee Society (KS) and Hospital for Special Surgery (HSS) scores. After 1:1 matching, 50 cases involved the LCS RP bearing system as group 1 and 50 cases involved LCS PS bearing system group as group 2. Clinical and radiographic outcomes were evaluated.Purpose
Methods
We describe five results of a novel single stage arthroscopic technique for the treatment of articular cartilage defects of the knee. This involves micro drilling and application of Atelo-collagen (Coltrix) and fibrin gel scaffold. The preclinical study involved two groups of rabbits treated with micro-drilling, and micro-drilling with Atelo-collagen and fibrin gel. New cartilage was subjected to staining with H&E for tissue morphology, toluidine blue (collagen) and safranin O (GAG), immunohistochemistry with antibodies for collagen type I and II, and scanning and transmission electron microscopy to analyse the microstructural morphologies. The micro-drilling with Atelo-collagen, fibrin gel scored better than the micro-drilling alone. Patients (n=30) with symptomatic ICRS grade III/IV chondral defects (lesion size 2–8cm2) are recruited for this prospective study. The surgical procedure involved micro-drilling and application of Atelo–collagen and fibrin gel under CO2 insufflation. Patients underwent morphological evaluation with MRI (T2*-mapping and d-GEMRIC scans). Clinical assessment was done with Lysholm, IKDC and KOOS scores. Radiological assessment was performed with MOCART score.Introduction
Materials and Method
The fourth generation ceramic, in which zirconia is incorporated into the alumina matrix, was developed to reduce the risk of ceramic fractures. The purpose of this study was to evaluate the survivorship, clinical and radiographic results, and bearing-related failures associated with total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings over a minimum follow-up of 5 years. We retrospectively analysed 135 patients (151 hips) who underwent cementless total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings. There were 58 men and 77 women with mean age of 55.9 years (range, 20 to 82 years) at index surgery. Acetabular and femoral components were cementless in all hips. A 36 mm head was used in 81 of 151 hips and a 32 mm head was used in 70 hips with smaller acetabular shells. The mean duration of follow-up was 6.1 years (range, 5 to 6.8 years).Purpose
Materials and methods
The mid- or long-term results of acetabular revision total hip arthroplasty (THA) in Korea are rare. The purpose of this study is to report the mid-term radiographic results (> 5 years) of acetabular revision THA with porous-coated cementless Trilogy® cup (Zimmer, Warsaw, IN, USA). Between 1999 and 2010, 77 patients (79 hips) had underwent acetabular revision THA with Trilogy® cup. Eight patients (8 hips) were excluded due to death before 5-year follow-up, and 22 patients (23 hips) were excluded due to less than 5-year follow-up or follow-up loss. Forty-seven patients (48 hips) were included in our study. The mean age was 57.9 years (range, 36 to 76 years) and the mean follow-up was 9.8 years (range 5.0 to 16.2 years). The causes of revision were aseptic loosening in 40 hips, and septic loosening in 8 hips, respectively. Both acetabular and femoral revisions were performed in 14 hips and isolated acetabular revision was done in 34 hips. Preoperetive acetabular bone defect according to Paprosky classification was; 1 in type I, 6 in IIA, 11 in IIB, 9 in IIC, 15 in IIIA, and 6 in IIIB.Introduction
Materials and Methods
Cross-linked polyethylene (XLPE) has shown reduced wear rates as compared to conventional polyethylene, but the long-term effect of this on the incidence of osteolysis remains unclear. In addition, the measurement of osteolysis on plain radiographs can underestimate the incidence and extent of osteolysis. Therefore, we evaluated the wear rate, incidence and volume of osteolysis at a minimum follow-up of ten years using three-dimensional computed tomography (3-D CT), a more accurate and sensitive method for detecting and measuring the size of osteolysis than plain radiographs. Between 2000 and 2004, 233 primary THAs were performed using 28-mm cobalt-chrome femoral head on first-generation XLPE (Longevity®, Zimmer, Warsaw, IN) with cups of identical design. Fifty-five patients (57 hips) deceased, eight patients (8 hips) were lost and four patients (4 hips) were revised due to recurrent dislocation (2 hips) or infection (2 hips). Among the remaining 164 hips, 95 hips underwent 3-D CT scanning (Aquilion® 64, Lightspeed Ultra® 16 or Optima® 660) at minimum 10 years (range, 10.0 to 15.2) and were included in this study. Mean age at the time of THA was 56.2 years and average body mass index was 23.5 kg/m2. Average cup size was 55.4 mm whereas mean inclination and anteversion angle of cups on CT scan were 40.1 and 17.4 degrees, respectively. Average follow-up period was 12.8 years. 2D wear rate was measured using PolyWare® 3D Rev 7 software (Draftware Inc, Vevay, IN). Osteolysis was strictly defined as a localized area of trabecular loss with a sclerotic margin. Osteoarthritic cyst and age-related osteoporosis were excluded using perioperative CT scan and magnetic resonance imaging or serial plain radiographs. The incidence, location, and volume of osteolysis were measured.Background/Purpose
Materials and Methods
Total hip arthroplasties (THAs) with ceramic bearings are widely performed in young, active patients and thus, long-term outcome in these population is important. Moreover, clinical implication of noise, in which most studies focused on ‘squeaking’, remains controversial and one of concerns unsolved associated with the use of ceramic bearings. However, there is little literature regarding the long-term outcomes after THAs using these contemporary ceramic bearings in young patients. Therefore, we performed a long-term study with a minimum follow-up of 15 years after THAs using contemporary ceramic bearings in young patients with osteonecrosis of the femoral head (ONFH) less than fifty. Among sixty patients (71 hips) with a mean age of 39.1 years, 7 patients (7 hips) died and 4 patients (4 hips) were lost before 15-year follow-up. The remaining 60 hips were included in this study with an average follow-up period of 16.3 years (range, 15 to 18). All patients underwent cementless THA using a prosthesis of identical design and a 28-mm third-generation alumina head by single surgeon. The clinical evaluations included the modified Harris hip score (HHS), history of dislocation and noise around the hip joint: Noise was classified into squeaking, clicking, grinding and popping and evaluated at each follow-up. Snapping was excluded through physical examination or ultrasonography. Radiographic analysis was performed regarding notching on the neck of femoral component, loosening and osteolysis. Ceramic fracture and survivorship free from revision were also evaluated.Background/Purpose
Materials and Methods
The use of tranexamic acid (TXA) in primary total hip arthroplasty (THA) is supported by many studies that confirm its efficacy for decreasing blood loss, but the comparison between topical intra-articular (IA) and intra-venous (IV) is unclear, especially combined with chemical prophylaxis. The purpose of this study is to verify non-inferior efficacy of topical IA TXA compared with IV TXA in primary THA. A single center, randomized, controlled clinical trial was performed to compare topical IA TXA (2 g of TXA in 100 cc of normal saline) with two IV doses of TXA (1 g dose before surgery and another 1 g dose 3 hours later) on blood loss. The primary outcome was total blood loss as calculated from the difference between the preoperative hemoglobin (Hb) and the lowest postoperative Hb. The secondary outcome included drained blood loss, transfusion volume, and thromboembolic events. The sample size of 112 patients was calculated to give a statistical power of 99% for demonstrating inferiority. Fifty-six patients each was assigned to receive topical IA TXA (IA group) and IV TXA (IV group). There were no significant differences in demographics and preoperative laboratory values between the two groups. Non-inferiority was estimated by comparing the confidence interval with a delta of 10%. All subjects took oral direct factor Xa inhibitor to prevent venous thromboembolism included during 2 weeks after surgery.Introduction
Methods & Methods
We aimed to investigate whether the anterior superior iliac spine could provide consistent rotational landmark of the tibial component during mobile-bearing medial unicompartmental knee arthroplasty (UKA) using computed tomography (CT). During sagittal tibial resection, we utilized the ASIS as a rotational landmark. In 47 knees that underwent postoperative CT scans after medial UKA, the tibial component position was assessed by drawing a line tangential to the lateral wall of the tibial component. Rotation of the tibial component was measured using two reference lines: a line perpendicular to the posterior cortical rim of the tibia (angle α) and Akagi's line (angle β). Instant bearing position and posterior cruciate ligament fossa involvement were also evaluated. External rotation of the tibial component relative to each reference line and external rotation of the bearing relative to the lateral wall of the tibial component were considered positive values.Purpose
Methods
The range of motion (ROM) obtained after total knee arthroplasty (TKA) is an important measurement to evaluate the postoperative outcomes impacting other measures such as postoperative function and satisfaction. Flexion contracture is a recognized complication of TKA, which reduces ROM or stability and is a source of morbidity for patients. The purpose of this study was to evaluate the influence of intra-operative soft tissue release on correction of flexion contracture in navigated TKA.Introduction
Objectives
Chondral defects of the knee are common and often seen in young and active individuals. A novel single stage arthroscopic technique for the treatment of articular cartilage defects in the knee is described. This involves microfracture and application of concentrated bone marrow aspirate cells (BMAC) with fibrin and Hyaluronic Acid as a gel. After a representative preclinical study, the 5 year results of a prospective clinical study are presented. The pre-clinical study involved two groups of rabbits with standardised lesions treated with microfracture alone and microfracture combined with fibrin/HA/BMAC application. New cartilage from both groups was subjected to staining with H&E for tissue morphology, toluidine blue (collagen) and safranin O (GAG), immunohistochemistry with antibodies for collagen type I and II, and scanning and transmission electron microscopy to analyse the microstructural morphologies. The fibrin/HA/BMAC group scored better than the microfracture group on all tests. A subsequent prospective clinical study patients (n=60) with symptomatic ICRS grade III/IV chondral defects (lesion size 2–8cm2). The surgical procedure involved debridement of the lesion, micro-fracture and application of fibrin/HA/BMAC gel under CO2 insufflation. Patients underwent morphological evaluation with MRI (T2*-mapping and d-GEMRIC scans). Clinical assessment employed the Lysholm, IKDC and KOOS scores while radiological assessment was performed with MOCART score. At 5 years, Lysholm score was 78, compared to 51 pre-operatively (p<0.05). KOOS (symptomatic) improved to 90 from 66 (p<0.05). IKDC (subjective) went to 80 from 39 (p<0.05). The mean T2* relaxation-times for the repair tissue and native cartilage were 26 and 29.9 respectively. Average MOCART score for all lesions was 70. This technique shows encouraging clinical results at 5 year follow-up. The morphological MRI shows good cartilage defect filling and the biochemical MRI suggests hyaline like repair tissue.
As the proximal femoral bone is generally compromised in failed total hip arthroplasty, achievement of solid fixation with a new component can be technically demanding. Clinical studies have demonstrated good medium-term results after revision total hip arthroplasty using modular fluted and tapered distal fixation stems, but, to our knowledge, long-term outcomes have been rarely reported in the literature. The purpose of this study was to report the minimum ten-year results of revision total hip arthroplasty using a modular fluted and tapered distal fixation stem. We analyzed 40 revision THAs performed in using a modular fluted and tapered distal fixation stem (Fig. 1) between December 1998 and February 2004. There were 11 men (12 hips) and 28 women (28 hips) with a mean age of 59 years (range, 38 to 79 years) at the time of revision THA. According to the Paprosky classification of femoral defects, 5 were Type II, 24 were Type IIIA, and 11 were Type IIIB. An extended trochanteric osteotomy was carried out in 21 (52%) of the 40 hips. Patients were followed for a mean of 11.7 years (range, 10 to 15 years).Introduction
Materials & Methods
Most of revision TKA needs bone reconstruction. The success of revision TKA depends on how well the bone reconstruction can be done. The method of reconstruction includes bone cementing, metal augmentation, allogenic bone graft, APC and tumor prosthesis, etc. In moderate to severe bone defect, allograft is needed. However, allogenic bone graft is surgically demanding and needs long operation time, which is very risky to the elderly patients. The authors revised an alternative method of bone defect reconstruction using cementing method with multiple screws augmentation. There were 12 cases of patients with large defect which could not be reconstructed with metal augment from April 2012 to April 2014. The authors performed 3 to 5 screws fixation on the defect site. Sclerotic bone is prepared with burring for better cementing. 3 ∼ 5 screws according to the size of defect. The length of screw fixation was determined as deep to the bone until stable fixation just beneath the implant. When drilling for the screw insertion, intramedullary guide is put into the medullary canal so as not to interfere with implant insertion. The defect is filled with cement during prosthesis fixation. Weight bearing was permitted on postoperative 3rd day, as usual manner of primary TKA.Purpose
Methods
The purpose of this study is to report the outcome of navigation-assisted cruciate-retaining total knee arthroplasty (TKA) using one type of cemented, second-generation, floating-platform (FP), mobile-bearing system. We retrospectively reviewed 42 patients (51 knees) who underwent cruciate retaining TKAs using e.motion-FP prostheses under navigational guidance. The preoperative diagnosis was osteoarthritis in all knees except one rheumatoid arthritis. There were 2 men (2 knees) and 40 women (49 knees) with a mean age of 64.0 ± 4.7 years (range, 51 – 76 years) at the time of index surgery. The mean follow-up was 120.0 months (range, 106 – 126 months). Clinical and radiographic results as well as mechanical survival rate of this type prosthesis were investigated at a mean follow-up of 10 years.Background
Methods
The acetabular cup should be properly oriented to prevent dislocation and to reduce wear and leg length discrepancy. Despite advances in surgical techniques and instrumentation, achieving proper cup placement in total hip arthroplasty (THA) is challenging with potentially large variations of cup position and limited accuracy. We evaluated whether cup placement on anatomical location ensured original center of rotation (COR) and surgeon's experiences of THA reduced variations in acetabular component positioning. We retrospectively reviewed 145 patients (145 hips) of unilateral THAs with normal contralateral structures of acetabulum and femoral head. All surgeries were performed using the modified posterolateral approach that preserves short external rotator muscles. All of the 145 THAs were performed by two surgeons, who were in the same teaching hospital, but had differences in surgical experience and expertise for THA. The patients were divided into two groups based upon surgical experience: (1) the highly experienced surgeon's group: who had previously performed over 1000 THAs (YSK, 101 hips), and (2) the less experienced novice's group: who had performed fewer than 30 THAs (YWL, 44 hips). Real vertical distances, from the COR to the inter-tear drop line, and the real horizontal distances, from the COR to the lateral wall of the tear drop, were measured preoperatively using picture archiving communication system (PACS) based precise method. Postoperative ones were measured and equalized by use of a magnification marker placed on preoperative plain radiographs. And cup inclination was measured directly on the AP radiographs and anteversion was calculated by trigonometric functions. The patient's mean age was 52.1 years (range, 20–86).Introduction
Methods
Management of the patella with poor bone stock remains a challenge in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate the results of a novel surgical technique in which widely available wires and acrylic bone cement are used in the reconstruction of a deficient patella. Twenty-eight patients (30 knees) underwent revision TKA in which a deficient patella was treated with an onlay-type prosthesis and bone-augmenting procedure, using transcortical wiring. The technique was indicated when the thickness of remnant patella was less than 8mm with variable amounts of the peripheral rim. The remaining patellar height ranged from 3.2mm to 7.3mm. Follow-up was available for all patients with a mean of 36.6 months (range, 24 to 55 months). The respective mean Knee Society scores for knee and function improved from 34.2 points (range, 18 to 65 points) and 23 points (range, 18 to 46 points) preoperatively to 73.5 points (range, 30 to 88 points) and 61points (range, 34 to 80 points) at final follow-up. The mean thickness of the patellar construct was 14.6mm (range, 12.2 – 18.3mm). One patient experienced patellar fracture during knee flexion one week after surgery. There were no complications associated with implanted hardware. A patellar bone-augmenting procedure using transcortical wiring is a straightforward technique that potentially allows firm fixation. Considering the satisfactory short- to mid-term results, we believe that this technique provides a good alternative option in addressing this challenging problem in revision TKA.
Deformity of knee joint causes deviation of mechanical axis in the coronal plane, and the mechanical axis deviation also could adversely affect biomechanics of the ankle joint as well as the knee joint. Particularly, most of the patients undergoing total knee arthroplasty (TKA) have significant preoperative varus malalignment which would be corrected after TKA, the patients also may have significant changes of ankle joint characteristics after the surgery. This study aimed 1) to examine the prevalence of coexisting ankle osteoarthritis (OA) in the patients undergoing TKA due to varus knee OA and to determine whether the patients with coexisting ankle OA have more varus malalignment, and 2) to evaluate the changes of radiographic parameters for ankle joint before and 4 years after TKA. We evaluated 153 knees in 86 patients with varus knee OA who underwent primary TKA. With use of standing whole-limb anteroposterior radiographs and ankle radiographs before and 4 years after TKRA, we assessed prevalence of coexisting ankle OA in the patients before TKA and analyzed the changes of four radiographic parameters before and after TKA including 1) the mechanical tibiofemoral angle (negative value = varus), 2) the ankle joint orientation relative to the ground (positive value = sloping down laterally), 3) ankle joint space, and 4) medial clear space.Introduction
Methods
