To date, few studies have investigated the feasibility of the loop-mediated isothermal amplification (LAMP) assay for identifying pathogens in tissue samples. This study aimed to investigate the feasibility of LAMP for the rapid detection of methicillin-susceptible or methicillin-resistant Staphylococcus aureus (MSSA or MRSA) in tissue samples, using a bead-beating DNA extraction method. Twenty tissue samples infected with either MSSA (n = 10) or MRSA (n = 10) were obtained from patients who underwent orthopedic surgery for suspected musculoskeletal infection between December 2019 and September 2020. DNA was extracted from the infected tissue samples using the bead-beating method. A multiplex LAMP assay was conducted to identify MSSA and MRSA infections. To recognize the Staphylococcus genus, S. aureus, and methicillin resistance, 3 sets of 6 primers for the 16S ribosomal ribonucleic acid (rRNA) and the femA and mecA genes were used, respectively. The limit of detection and sensitivity (detection rate) of the LAMP assay for diagnosing MSSA and MRSA infection were analyzed. The results of this study suggest that the LAMP assay performed with tissue DNA samples can be a useful diagnostic method for the rapid detection of musculoskeletal infections caused by MSSA and MRSA.
The aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models. Five subject-specific musculoskeletal models were validated with computationally predicted muscle activation, electromyography data, and previous experimental data to analyze effects of the ALL and ACL on knee kinematics under gait and squat loading conditions.Objectives
Methods
ONFH with large or lateral-located lesion is challenging due to difficulty of regeneration. We introduce novel tissue engineering technique using ex vivo expanded bone marrow stromal cell seeded on calcium metaphosphate (CMP) scaffold to regenerate dead bone for these challenging cases. Ten millilitres of bone marrow was aspirated from iliac crest and mononuclear cells were collected. These cells were expanded and differentiated to osteoblast-lineage cells using osteogenic media and autologous serum for 2–4 weeks ex vivo. Porous bead-form scaffolds were made of CMP and cells were seeded in a density of million/ml³ into 20 to 30 beads for 1 hour. The necrotic area was curetted and the beads were implanted through core tract in 9 hips (Steinberg IIc in 5 hips and IVc in 4 hips which involved greater than 30% of whole head; JIC classification C1 in 4 hips, and C2 in 5 hips which involved weight bearing area). The tract was blocked with a CMP rod. The age of patients ranged from 16 to 37. Associated factors were; steroid in 4, idiopathic in 3, alcoholic in 1 and traumatic in 1 hip, respectively. Kerboul combined necrotic angle was more than 200° in all hips. We compared preoperative and annual radiographs and MRI images to check dome depression of femoral head and signal change of osteonecrotic area. Follow-up period ranged from 8 to 14 years. Two IIc lesions progressed and were converted to THA at two and six years postoperatively. We could get clinical and radiographic success in 7 hips (78%). Follow-up radiographs and MRI showed partial or nearly complete regeneration of necrotic bone, prevention of collapse, and reduction in necrotic lesion. This can be a good strategy for bone regeneration of unmet need as in a human model.
We evaluated (1) wear rate, (2) prevalence and volume of osteolysis using 3D-CT scan, (3) other bearing-related complications, (4) HHS and survivorship free from revision at 15 years after THA using first-generation XLPE (1G XLPE). One-hundred sixty THAs were evaluated regarding bearing-related complication, HHS and survivorship. Among them, 112 hips underwent 3D-CT to analyze wear rate and osteolysis. All THAs were performed by single surgeon using cup of identical design, a 28-mm metal head and 1G XLPE (10 Mrad). Average age were 57 years and mean follow-up was 15.2 years. 3D-CT scan was performed at average of 13.0 years. Clinical evaluation included HHS and radiographic analysis was performed regarding stem alignment, cup anteversion and inclination angle, component stability, wear rate and osteolysis. Wear was measured using digital software. The prevalence and volume of osteolysis were also evaluated. Complications included XLPE dissociation/rim fracture, dislocation, periprosthetic fracture, infection, HO and any revision. Survivorship free from revision at 15 years was estimated. Average inclination and anteversion angle of cups were 40.7° and 20.6°. Mean stem alignment was 0.1° valgus. Average bedding-in and annual wear rate wear rate was 0.085 mm and 0.025 mm/yr. Eleven hips (10%) demonstrated osteolysis; pelvic osteolysis with average volume of 1.4 cm3 in six and femoral osteolysis with mean size of 0.4 cm2 in seven hips. Of 160 THAs, 5 hips (3%) dislocated. Overall, bearing-related complications occurred in 16 hips (10%). Other complications included postoperative periprosthetic fracture in 4 (3%), infection and HO in 3 hips, respectively. No hip demonstrated loosening, XLPE rim fracture/dissociation. Seven THAs (4%) were revised; recurrent dislocation in 5 and periprosthetic joint infection in 2 hips. Average HHS at last follow-up improved from 47.7 preoperatively to 91.2 points (p<0.001). Estimated survivorship free from revision at 15 years was 95.6 %. THA using 1G XLPE demonstrated low wear rate as well as low incidence of osteolysis at average follow-up of fifteen years. Longer-term studies will be necessary to determine if XLPE will continue to demonstrate this improved osteolysis characteristics.
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
The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.Objectives
Methods
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
Patients with osteonecrosis of the femoral head are typically younger, more active, and often require high rates of revision following primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have been rarely reported in the literature. The purpose of this study was to report the intermediate-term clinical and radiographic outcomes of revision hip arthroplasty in patients with osteonecrosis of the femoral head. Between November 1994 and December 2009, 187 revision hip arthoplasty were performed in 137 patients who had a diagnosis of osteonecrosis of the femoral head. Exclusion criteria included infection, recurrent instability, isolated polyethylene liner exchange, and inadequate follow-up (less than 3 years). The final study cohort of this retrospective review consisted of 72 patients (75 hips) with a mean age of 53.3 years (range, 34 to 76). Components used for the acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 2 hips. Components used for the femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. The mean duration of follow-up was 7 years (range, 3 to 17).Introduction
Materials & Methods
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
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.
Modern ceramic-on-ceramic bearings have become attractive alternatives to conventional polyethylene due to their low wear and minimal particle production. However, ceramic-on-ceramic implants have been associated with ceramic fracture and squeaking. To address these issues, large ceramic heads with a titanium-alloy sleeve have been introduced although limited data are available on their clinical outcomes. The purpose of this study was to report the midterm results of primary total hip arthroplasty using a 32mm with a titanium-alloy sleeve. We reviewed 245 patients who had 274 total hip arthroplasties with a 32 mm ceramic head with a titanium-alloy sleeve and had been followed for more than 5 years (average, 6.5 years; range, 5–9 years). The mean patient age at the time of surgery was 55.1 years (range, 16–82 years). All operations were performed at a single center. All of the ceramic implants were hot isostatic pressed, laser-marked, proof-tested third-generation alumina (Fig. 1). We determined the implant survival, Harris hip scores, incidence of ceramic fracture or noisy hips, and presence of osteolysis.Introduction
Materials & Methods
Theoretically, improved material properties of new alumina matrix composite (AMC) material, Delta ceramics, are expected to decrease concerns associated with pure alumina ceramics and allow manufacturing thinner liners and consequent larger heads. However, limited short-term clinical results are available and mid-term results of these effects are unclear. (1) Does AMC material decrease the rate of ceramic fracture and noise, concerns of previous-generation ceramics, following change of material properties? (2) Does the possible use of larger heads consequent to manufacturing thinner liners decrease dislocation rate and affect inguinal pain? (3) Do any other complications associated with the use of AMC ceramics occur?Background
Questions/Purposes
Even a number of studies have reported clinical outcomes after revision total knee arthroplasty (revision TKA), little information is still available on whether outcomes of patients undergoing a revision TKA as a second stage procedure because of infected TKA are poorer than those of the patients undergoing a single-stage revision TKA because of non-infectious causes. In addition, use of various revision prostheses in most previous studies may limit solid interpretation of the outcomes after revision TKA. This study sought to determine whether outcomes in patients undergoing revision TKA due to infected TKA would be different from those in patients undergoing revision TKA due to non-infectious causes. We assessed 71 cases undergoing revision TKAs with use of a same revision system (Scorpio TS®, Stryker, Mahwah, NJ) from October 1999 to February 2012. All patients followed more than two years and mean follow-up period was 67 months (range: 24 – 168 months). Of them, thirty five patients underwent revisions due to infected TKA (group for infected TKA) while 36 patients due to non-infectious causes including loosening, wear, and/or instability (group for non-infected TKA). All patients in the group for infected TKA underwent two-stage revision surgeries while all patients in the group for non-infected TKA single stage revision surgeries. Comparative variables between two groups were preoperative range of motion (ROM) and American knee society (AKS) scores, postoperative ROM and AKS scores assessed at latest follow-up, amount of bone loss and requirement of stem assessed during the surgeries, and survival rate.Introduction
Materials and 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).Background
Methods
Highly cross-linked polyethylene has been introduced to decrease osteolysis secondary to polyethylene wear debris generation, but there are few long-term data on revision total hip arthroplasty using highly cross-linked polyethylene liners. The purpose of this study was to report the long-term radiographic and clinical outcomes of a highly cross-linked polyethylene liner in revision total hip arthroplasty. We analyzed 63 revision total hip arthoplasties that were performed in 63 patients using a highly cross-linked polyethylene liner between April 2000 and February 2005. Of these, nine died and four were lost to follow-up before the end of the 10-year evaluation. Thus, the final study cohort consisted of 50 patients (50 hips). There were 26 males and 24 females with a mean age at time of revision total hip arthoplasty of 53 years (range, 27–75 years). Mean duration of follow-up was 11 years (range, 10–14 years).Introduction
Materials & Methods
Total knee arthroplasty (TKA) is a proven treatment method for advanced knee arthritis in terms of pain relief, function restoration, and quality-of-life improvement. The TKA use has increased significantly over the past decade and the growing rate is more prominent in Asian countries. Thus, the revision TKA may also increase in recent days, which represents a burden to the national health care system. To the best of our knowledge, little information is currently available regarding the incidence and related factors of revision TKA in Asian countries on the basis of nationwide database. This study sought to find the incidence of revision TKA and related factors in South Korea using national database from 2007 to 2012. Data collected by the Health Insurance Review Agency of Korea, from 260,068 TKA patients between 2007 and 2012, were used to estimate the incidence of revision TKA according to age group, gender and hospital TKA and manufacturer prosthesis volume (i.e., the number of TKA procedures carried out at a given hospital, and the number of procedures performed using a given manufacturer's prosthesis, respectively). Age group and hospital and manufacturer volumes were categorized into three groups and TKA incidence rates were computed for groups stratified according to age, gender and hospital and manufacturer volumes.Introduction
Material and Method
We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing. This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs. Ten-year survivorship analysis was performed using the Kaplan-Meier method with additional surgery for any reason as the end-point. Furthermore, long-term clinical and radiographic results of 109 knees (74%; 84 patients) with more than a 10-year follow-up were analyzed. Ten-year survivorship and long-term outcomes after surgery were determined, and outcomes were compared between patients with and without patellar resurfacing.Introduction
Materials and Methods
3-D Printing with direct metal tooling (DMT) technology was innovatively introduced in the field of surface treatment of prosthesis to improve, moreover to overcome the problems of plasma spray, hopefully resulting in opening the possibility of another page of coating technology. We presumed such modification on the surface of Co-Cr alloy by DMT would improve the ability of Co-Cr alloys to osseointegrate. We compared the in vitro and in vivo ability of cells to adhere to DMT coated Co-Cr alloy to that of two different types of surface modifications: machined and plasma spray(TPS). We performed energy-dispersive x-ray spectroscopy and scanned electron microscopy investigations to assess the structure and morphology of the surfaces. Biologic and morphologic responses to osteoblast cell lines of human were then examined by measuring cell proliferation, cell differentiation (alkaline phosphatase activity), and avb3 integrin. The cell proliferation rate, alkaline phosphatase activity, and cell adhesion in the MAO group increased in comparison to those in the machined and grit-blasted groups.Introduction
Method
We describe a single stage arthroscopic procedure for the treatment of articular cartilage defects in the knee. The novel procedure involves microdrilling and application of atellocollagen and fibrin gel. The aim of the study was to evaluate the clinical outcomes at 4 years. A prospective study of 30 patients with symptomatic ICRS grade III/IV chondral defects which were assessed clinically and radiologically. The lesions were located on the MFC, LFC, trochlea or patella, ranging from 2–8cm2. The surgical procedure involved debridement of the lesion, microdrilling and application of atellocollagen and fibrin gel under CO2 insufflation. Patients were clinically assessed using the Lysholm, IKDC and KOOS scores. Radiological assessment used the MOCART score.Introduction
Materials and Methods
We describe a novel single stage arthroscopic repair procedure for articular cartilage defect in the knee. The aim of the study was to evaluate the clinical and radiological outcomes at two years. The pre-clinical study involved two groups of New Zealand rabbits, treated with microfracture alone and microfracture combined with fibrin gel and concentrated bone marrow aspirate cells (BMAC) application. New cartilage from both groups was studied with histological staining, immunohistochemistry and electron microscopy. The fibrin gel-BMAC group scored better than the microfracture group on all counts. This is a prospective study of 30 patients with symptomatic ICRS grade III/IV chondral defects, ranging from 2–8 cm2, which were assessed clinically and radiologically. The surgical procedure involved debridement of the lesion, microfracture and arthroscopic application of concentrated BMAC with fibrin gel under CO2 insufflation. Patients underwent morphological MRI, quantitative T2*-mapping and d-GEMRIC scan. Clinical assessment was carried out using the Lysholm, IKDC and KOOS scores while radiological assessment used the MOCART score. At 2 year follow-up, Lysholm score was 80.1, as compared to 50.8 pre-operatively (p < 0.05). KOOS (symptomatic) was 92.1, as compared to 65.7 pre-operatively. IKDC (subjective) was 83, up from 39 preoperatively. The mean T2* relaxation-times for the repair tissue and native cartilage were 29.1 and 29.9 respectively. Average MOCART score for all lesions was 72. Our technique shows encouraging clinical and radiological results. The morphological MRI shows good cartilage defect filling and the biochemical MRI (T2*-mapping) suggests hyaline like repair tissue.
Obovatol inhibits receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis and prevents inflammatory bone loss in mice Adult skeletal mass and integrity are maintained by balancing osteoclast-mediated bone resorption and osteoblast-induced bone formation during bone remodeling. Abnormal increases in osteoclastic bone resorption can lead to excessive bone destruction as observed in osteoporosis, rheumatoid arthritis, and metastatic cancers Therefore, Modulation of osteoclast formation and function is a promising strategy for the treatment of bone-destructive diseases. To search for compounds that inhibit osteoclast formation, we tested the effect of obovatol, a natural product isolated from the medicinal plant Summary Statement
Introduction
Whole blood metal ion level and clinical outcomes of ceramic-on-metal bearing were comparable to ceramic-on-ceramic THA in this prospective randomized controlled trial. We randomized 150 consecutive THA cases at one institution into two groups: Group I and Group II. Group I, 75 cases, received a THA using ceramic-on-metal couplings and Group II, 75 cases, received ceramic-on-ceramic bearing THA. The implant differed only in the bearing surfaces used. We compared the serum levels of cobalt (Co) and chromium (Cr) and functional outcome scores preoperatively, and at 2, 6, and 12 months postoperatively.Introduction:
Methods:
The robot-assisted cementless total hip arthroplasty has theoretical advantages of providing better fit and mechanical stability of the stem. However, no previous study has been reported on a short stem implantation using surgical robot. We compared early clinical and radiographic results between robotic milling and manual rasping in short stem total hip arthroplasty. We designed a prospective randomized controlled trial to determine whether robot-assisted short stem total hip arthroplasty improves the implant position represented by stem alignment, leg length equality, and reduces the intraoperative and early postoperative complications. A total of 40 patients were enrolled with informed consents and randomly assigned to robotic milling group (20 hips) and manual rasping group (20 hips) by means of a computer-generated random number table. There were no statistically significant differences in the demographics of the patients between the two groupsIntroduction:
Materials & Methods:
Ceramic head with titanium-alloy sleeve offers a modular ceramic head solution for the damaged taper in revision total hip arthroplasty (THA). It can also be used in primary THA to reduce the risk of ceramic head fracture. The purpose of the present study was to report the intermediate-term outcomes of primary ceramic-on-ceramic THA with use of ceramic head with titanium-alloy sleeve. We evaluated 244 patients (271 hips) who had undergone primary ceramic-on-ceramic THA with use of BIOLOX® forte 32 mm ceramic head with titanium-alloy sleeve between November 2005 and August 2009. There were 158 males (175 hips) and 86 female (96 hips) patients with a mean age of 55.5 years. Clinical and radiographic evaluation was performed at a mean of 4.6 years (range, 2–7 years) postoperatively.Introduction:
Materials & Methods:
The management strategy regarding optimally addressing polyethylene wear with a well-fixed acetabular shell remains controversial. The purpose of the present study was to document outcomes of cementation of a highly cross-linked polyethylene (PE) liner into a well-fixed acetabular metal shell in 36 hips We identified 37 patients (39 hips) who had undergone revision THA by cementation of a highly cross-linked PE liner into a well-fixed metal shell between June 2004 and April 2009. Of these patients, one (1 hip) died before the end of the 3-year evaluation and another was lost to follow-up. Thus, the study cohort consisted of 35 patients (36 hips). There were 23 males (24 hips) and 12 female (12 hips) patients with a mean age at time of revision surgery of 57.6 years (range, 38–79 years). All operations were performed by a single surgeon using only one type of liner. Clinical and radiographic evaluation was performed at a mean of 6.1 years (range, 3–8 years) postoperatively.Introduction:
Materials & Methods:
Melorheostosis is a very rare mesenchymal dysplasia of bone, characterized by sclerosing hyper-pigmentation appearances on the bone, may involve the adjacent soft tissues and lead to joint pain, limitation of joint motion and stiffness as a result of abnormal ossifications and soft tissue contractures, due to periarticular fibrosis. It is well known to tend to affect only one limb, but multifocal involvement, such as multiple limbs, spine and rib, has been extremely rarely reported. A variety of treatment options have been tried so far, none being specific surgical treatments. Here we present a case of a 43-year-old man who sustained melorheostosis with multifocal involvement including the axial skeleton and a whole entire lower limb. He had painful swelling of his left lower limb and mainly complained of difficulty walking due to severe hip pain and knee stiffness, which persisted for 20 years and was aggravated during the last 5 years. Total hip arthropasty [Fig. 1] was done first, and then total knee arthroplasty [Fig. 2, 3] was performed. During operation, there were difficulties in bone cutting and implant insertion due to mixed pattern of hard sclerotic portion and osteoporotic portion despite complete synovectomy and sufficient soft tissue release. He was eventually free of pain during walking and able to walk without a crutch and joint motion of hip and knee was substantially improved after surgery. We found that hip pain and contracture due to osteoarthritis and knee contracture secondary to multifocal melorheostosis could be successfully treated by total hip and knee arthroplasty. To the best of our knowledge, this is the first reporting the total joint arthroplasty performed in the patients with multifocal melorheostosis.
Soft-tissue balancing is crucial in total knee arthroplasty, but proper release of medial collateral ligament is a challenging procedure. It has been well recognized that medial gap tends to be more tight than lateral gap in varus knees after surgery. The purpose of this study is to investigate the incidence and predictable factors of medial tibial bone remodeling following navigation-assisted total knee arthroplasty. One hundred and sixty-six consecutive patients (221 knees) who underwent navigation-assisted total knee arthroplasty and followed during a minimum of 1 year were included in this study. Radiographic examination including anteroposterior and lateral view of both knees were performed at a regular follow-up schedules of 6 weeks, 3 months, 6 months, 1 year and thereafter, annually after surgery. An independent investigator identified the presence of medial tibial bone remodeling at each follow-up. All information on potential factors affecting medial tibial remodeling were retrieved and classified into 2 types (patient- and surgery-related).Background and Purpose
Materials and methods
Many literatures regarding more specific tests to diagnose the supraspinatus tendon injuries and the best rehabilitation methods to strengthen the supraspinatus have been published. However, conflicting results have been reported. 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) has been recently used to assess skeletal muscle activities in various fields. To evaluate & compare the metabolic activities of deltoid & rotator cuff muscles after the full-can & empty-can exercises using PET-CT.Introduction
Purpose
In total hip arthroplasty (THA), one of concerned issues is osteolysis due to wear debris of ultra-high molecular weight polyethylene (PE) which often leads to aseptic loosening. Reduction of PE wear debris is essential to prevent osteolysis, and different bearing combination as well as improvement of the bearing material itself have been attempted. Hence alumina ceramics was introduced for THA, aiming to reduce PE wear debris. Ceramic on PE couple showed good results in clinical wear compared with metal on PE couples. Highly cross-linked PE (HXLPE) with gamma-ray or electron-beam irradiation followed by thermal treatment has also demonstrated a remarkably low wear in the previous in vitro studies. In in vivo studies, the wear of HXLPE acetabular cups against alumina ceramic femoral head was evaluated to compare with that of conventional PE cups against alumina ceramic femoral head. The in vivo wear of 61 HXLPE cups (Aeonian; Kyocera Corp., Kyoto, Japan, currently Japan Medical Materials Corp., Osaka, Japan) against alumina ceramic femoral head of 28 mm in diameter with clinical use for 2.1–7.1 years (mean 5.6 years) and eight conventional PE cups against an alumina ceramic femoral head of 28 mm in diameter used for 18.7–23.3 years (mean 20.4 years) were examined by radiographic analysis with Vector Works 10.5. The in vivo wear of eight retrieved HXLPE cups with clinical use for 0.9–6.7 years (mean 2.9 years) and 14 retrieved conventional PE cups used for 16.0–28.0 years (mean 22.0 years) were examined by using a three-dimensional coordinate measuring machine. The worn surfaces of retrieved HXLPE and conventional PE cups were observed by a scanning electron microscope. In the radiographic study, penetration rate of alumina head into HXLPE and conventional PE for the first 1 year were 0.24 mm/year and 0.34 mm/year respectively. One year later, the HXLPE showed significant lower penetration rate of 0.001 mm/year than the conventional PE penetration rate of 0.12 mm/year (p<
0.01). By the retrieval analysis, the mean penetration of retrieved HXLPE and conventional PE cups were 0.11 and 2.97 mm, and they were similar to the results by radiographic analysis. In the worn surface of the retrieved HXLPE cups used for around 1 year, machine marks were observed. In contrast, the worn surface of the retrieved HXLPE cups used for more than five years were smooth, and furthermore, in high magnification observation they had wear morphology different from conventional PE. These findings from this retrieval study suggest the penetration in the first 1 year detected by radiographic measurement was probably caused by creep deformation in bedding-in stage; and 1 year after, the penetration was probably caused mainly by wear. By the radiographic analysis, HXLPE cups against alumina ceramic femoral head has a 99 % lower wear rate compared with conventional PE cups. Also, retrieved HXLPE cups against alumina ceramic femoral head exhibited lower wear compared with conventional PE cups. In conclusion, we expect that the HXLPE cup used with alumina ceramic femoral head has favorable wear properties in long-term clinical use.
A consensus on total hip arthroplasty (THA) concluded that the major remaining issues of concern included the long-term fixation of the joint replacement, osteolysis due to poluethylene (PE) wear debris which often leads to aseptic loosening. Alumina ceramics had been extensively used in medicine, and we started using the alumina ceramic for THA bearing surface in hopes to reduce the PE debris. It was because alumina ceramics is advantageous for precision machining compared with metal materials, and its hardness is higher than that of metal materials. Also, to augment cement–bone bonding, we interposed hydroxyl apatite (HA) granules at the cement–bone interface, so called “Interface Bioactive Bone Cement (IBBC) technique”. HA granules (2–3 g) were smeared on the bone surface of the acetabulum and femur just before cementing. In this study, we evaluated 19–22 years clinical results of THA with alumina ceramic head combined with PE cup fixated IBBC technique. Total 285 joints (212 patients) were implanted by one senior surgeon from January 1986 to December 1988, and 265 joints (192 patients) were traceable. Alumina ceramic femoral head of 28 mm in diameter and acetabular cup of the conventional PE sterilized with ethylene oxide gas were used in all patients. The PE cup and stem were fixed with IBBC technique in all cases. The presence of radiolucent line, loosening and osteolysis were observed using radiograph of the traceable cases. The locations of radiolucent lines were identified according to the zones described by DeLee and Charnley for acetabular cups and the zones described by Gruen et al. for femoral stems. The in vivo wear of 21 PE acetabular cups for 19.0–21.9 years (mean 20.3 years) was measured from the latest radiographs using computer assistant technique with Vector Works 10.5 software. Features of the clinical radiograph images of the IBBC case were classified as follows: the radiolucent line represented “gap” between the HA layer and the cement; the loosening represented “opening” between the HA layer and the cement. For the quantitative analysis, we divided the surrounding bones of the THA into several zones as done in the previous studies. The “gap” appeared in zone 4 in three joints (1.4 %), in zone 3 in two joints (0.9 %) of acetabular cup. In femoral side, in zone 1 in four joints (1.8 %) in zone 7 in one joint (0.4 %). The “opening” appeared in three acetabular cup (1.4 %). Since no opening was appeared in zone 3 or zone 4, however, no re-operation was needed. Images of osteolysis were seen one in zone 1 (0.5 %), and one in zone 2 (0.5 %) in acetabular side and two in zone 1 (0.9 %) of the femur. The mean linear wear rate of PE acetabular cups was 0.13 mm/year. The fixation to the bone by the IBBC technique has been maintained for long term. We think that the result was brought by the biological integration between bone and HA granules. In conclusion, this study has shown satisfactory results of the cemented THA with ceramic head combined with PE cup for 19–22 years.
The osseointegration of implants is related to the early interactions between osteoblastic cells and titanium surfaces. The behavior of osteoblast cells was compared on four different titanium surfaces in vitro and in vivo: machined, blasted, plasma spray and micro-arc oxidation. X-ray diffraction and scanning electron microscope investigations were performed in order to assess the structure and morphology. Biologic and morphologic responses to the osteoblast cell lines (Saos-2) were then examined, using Promega proliferation assay, alkaline phosphatase activity, vβ3 integrin expression and cytoskeleton staining (Rhodamine-Phallodine). The analysis of gene expression for osteocalcin and collagen I was done through RT-PCR. In addition, differential histologic evaluation and interfacial strength at the bone-implant interfaces were then evaluated in the distal femur of four beagle dogs. In conclusion, micro-arc oxidation of titanium appears to exhibit more favorable osteoblast adhesion and stronger interfacial strength than the compared groups in vitro and in vivo as well.
Aseptic loosening induced by wear debris of polyethylene (PE) is the most common cause of long-term total hip arthroplasty failure. In the previous studies, we reported that the protruding contour and surface morphology of metallic femoral head brought an increase of PE wear. Alumina ceramics is advantageous (neutral shape and smooth surface) for precision machining compared with metal materials, because hardness of ceramics is higher than that of metal materials. In this study, we measured the roundness and the roughness of retrieved alumina ceramic and metallic heads, aiming to evaluate the change of surface morphology of those heads in vivo. Fourteen retrieved alumina ceramic femoral heads (Kyocera Corp., currently Japan Medical Materials Corp.) were examined: ten femoral heads were made of small grain-size alumina ceramic (SG-alumina; mean grain size is 3.4 um) with a diameter of 28 mm, with clinical use for 16–28 years (mean 22 years) and four femoral head was made of extra-small-grain size alumina ceramic (XSG-alumina; mean grain size is 1.3 um) with a diameter of 26 mm, with clinical use for 14–19 years (mean 16 years). Six retrieved metallic femoral heads with average clinical use for 12–28 years (mean 18 years) were examined: a diameter of from 22 to 32 mm (e.g. Zimmer Inc., Stryker Corp.) The roundness of the retrieved femoral heads was measured by a contour tracer. The surface roughness in the contact area and the non-contact area of the retrieved femoral heads was measured by a surface roughness tester. Out-of-roundness of SG-alumina and XSG-alumina heads was 0.15 um and 0.19 um, respectively. In contrast, that of metal heads was 2.43 um, and the profiles were in wide distortion compared with both alumina heads. The surface roughness was 0.012 um in the contact area, and 0.009 um in the non-contact area of retrieved SG-alumina heads. The surface roughness in the contact area, 0.007 um, of XSG-alumina was slightly higher than that in the non-contact area, 0.003 um, and the both area of XSG-alumina represent lower value than SG-alumina, with all alumina heads having a reentrant surface profile. In contrast, the surface roughness of metallic heads was in a range of 0.003–0.053 um and several heads showed the protrusion surface profile. In this retrieval study, the roundness and the roughness of both alumina ceramic femoral heads after long-term clinical use were low and stable compared with metallic heads. And also, the surface roughness increased in the order of XSG-alumina <
SG-alumina <
metallic head. The alumina ceramic femoral head showed the reentrant surface whereas the metallic head showed the protruding surface. When third-body wear occurs during the clinical use, generally reentrant form may occur on the ceramic surface whereas protrusion form may occur on the metallic surface. We have good clinical results more than 20 years using the SG-alumina, and clinical results for a long term will be expected with XSG-alumina of improved microstructure.
We evaluated the outcome of hemiarthroplasty with bone block graft and low profile prosthesis (Aequalis® fracture prosthesis) for the comminuted proximal humerus fractures. Sixteen low profile prostheses were used since July 2004, and 11 patients were followed-up for average 19.9 (12–30) months. Their mean age was 67.3 (52–78) years. Cemented stem in all cases. Two bone block graft and cancellous chip bone from resected humeral head. Ten cases for Neer type 4 fracture, one case for type 3 fracture. During 6 weeks, abduction brace with neutral rotation position was maintained. Passive and active range of motion exercise started at 6 weeks. Pain and satisfaction visual analog scale (VAS), range of motion, and modified UCLA score for hemiarthroplasty were evaluated at every visit. Radiography was also checked for stem position, loosening, and tuberosity union. Mean pain VAS was 2.7 (0–5), and mean satisfaction VAS was 8.4 (5–10). Mean active forward flexion was 137o (90–170), external rotation at side was 45.5o (25–70), and internal rotation at back was T10 (T7-L1). Modified UCLA score was 19 (12–30) at final visit. All stems were stable, and there were no loosening at the final follow-up. All tuberosities were united except two tuberosity absorptions. One complication case was infection. The outcome of hemiarthroplasty with bone block graft and low profile prosthesis was comparable to other implants for comminuted proximal humerus fractures. This system had unique advantages for tuberosity union. Further study with more patients and longer follow-up period are necessary to clarify the effectiveness of this prosthesis.
