Introduction. Some patients complain ingrown pain or discomfort after implanting Co-Cr conventional endprosthesis of the hip. Some of this complaint may be attributable for effect on cartilage metabolism. It have been reported that ceramic is bioinert for biological tissue. On the other hand, metal including cobalt-chrome (Co-Cr) have some detrimental effect on biological tissue. However, there is no report concerning acetabular cartilage metabolism after hip endprosthesis implantation. In the present study, we hypothesized that ceramic head have small detrimental effect on cartilage cell metabolism. Specific aim of the study is to compare the protein level of inflammation related cytokines, amount of hyaluronic acid (HA) in culture media, and cartilage mRNA expression in organ culture model of hip end prosthesis implanted using ceramic head and Co-Cr head. Materials and Methods. Six acetabulum of 3 matured crossbred pig (average weight: 36 +/− 3.6kg) was retrieved. Animal experiment was performed under the rules of ethical committee of animal experiment. Average diameter of pig acetabulum was 26.3 +/− 0.6 mm. Just after sacrifice, mechanical loading using Instron testing machine with 26mm diameter of Co-Cr in right hip and Ceramic heads in left hip was performed in culture media. Ten thousand cycles of cyclic compression and rotation load (1.5kN to 0.15kN of compression and 12 degrees of rotation) to cartilage was applied at 1Hz (Figure 1). Culture media was analyzed for protein levels of inflammation related cytokines and amount of HA. Relative quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) from acetabular cartilage was performed as previously reported using specific primer sets for type II collagen, aggrecan, TNF-alpha, Interleukine-1 and 6, and MMP-1, 3, 13. Results. IL-1 beta protein level from culture media was significantly higher in Co-Cr than that in Ceramic (155+/−25.2 pg/ml vs. 86.3+/−9.6 pg/ml respectively). MMP-3 protein level had tendency to be higher in culture media from Co-Cr than that from Ceramic (16.3+/−10.6 ng/ml vs. 10.0+/−0.1 ng/ml respectively, p<0.05), however there was no significant difference. There were no significant differences of protein levels from culture media in MMP-1, IL-1a, and TNF between two groups. Amount of HA from culture media of Co-Cr group was significantly higher than that from Ceramic group (337+/−38.4 mg/ml versus 257+/−11.1 mg/ml respectively, p<0.05). Type II collagen mRNA expression was 3 times higher in Ceramic group than that in Co-Cr group. IL-1 beta mRNA expression was 4 times higher in Co-Cr group than that in Ceramic group. Other gene expression had no significant differences. Discussion. The present study showed that Co-Cr affects cartilage metabolism than Ceramic. Co-Cr group had higher protein level and mRNA expression of inflammation related cytokine, IL-1 beta, and higher HA. Concerning the mRNA expression from cartilage, type II collagen was significantly higher in Ceramic group. It has been reported that HA level is high in osteoarthritic joint. These report and our results showed that ceramic head have small detrimental effect on cartilage cell metabolism. There are limitations of the present study. Firstly, the sample size is small. Secondly, we did not evaluate synovial membrane metabolism

Introduction. In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions. Methods. In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534-539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 - cleavage lesion; Grade 3 - delamination and Grade 4 –exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa. For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics. Results. We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96). In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions seen at hip arthroscopy

The objective of this study is to compare three dimensional (3D) postoperative motion between metal and ceramic bipolar hip hemiarthroplasty for femoral neck fracture. Materials and Methods. This study was conducted with forty cases (20 cases of metal bipolar hemiarthroplasty (4 males, 16 females), 20 cases of ceramic bipolar hemiarthroplasty (2 males, 18 females)) from November 2012 to November 2014. Average age was 80.8±7.5 years for the metal bipolar group and 79.3±10.5 years for the ceramic bipolar group. We obtained motion pictures from standing position to maximum abduction in flexion by fluoroscopy then analyzed by 2D–3D image matching method. The motion range of the “Shell angle”, “Stem neck angle” and the “Stem neck and shell angle” has been compared between the metal bipolar group and the ceramic bipolar group (Fig. 1). Results. Metal bipolar showed greater variability of the Stem neck angle and Shell angle than ceramic bipolar. Six of the twenty cases reached unilateral oscillation angle of 37 degrees in metal bipolar. In other words, 30% of metal bipolar group revealed neck-shell impingement. No case reached oscillation angle of 58 degrees in ceramic bipolar group. There was no significant difference between the metal bipolar group and the ceramic bipolar group with respect to the difference of minimum and maximum angle of Stem neck angle (movement range of the stem neck) and Shell angle (movement range of the bipolar cup). On the other hand, difference of minimum and maximum angle of the Stem neck and shell angle (movement range of the inner head) was significantly greater in the metal bipolar group than the ceramic bipolar group. Movement, range of bipolar shell was significantly greater than that of inner head in both groups (Table 1). Discussion. The present study is the first report using 2D–3D image matching method in bipolar impingement. From the result of our study, bipolar shell moves greatly against the acetabular cartilage for both metal bipolar and ceramic bipolar, and the range of movement of the outer shell was significantly greater than the range of movement of the inner head. It indicates that most of the movement actually occurs between outer shell and acetabular cartilage, despite bipolar prosthesis having a double bearing function intrinsic to the design. Impingement between the shell and the stem neck was found six of twenty cases with metal bipolar group and no impingement occurred with ceramic bipolar group. The present results showed that the ceramic bipolar has the possibility to avoid the characteristic complications of the bipolar caused by the wear debris produced by impingement. In conclusion, the metal bipolar group's inner head's range of movement was greater than the ceramic bipolar group. The impingement between stem neck and shell occurred in the 30% of metal group patients. On the other hand, there were no impingement cases for the ceramic bipolar group. We expect good long term clinical result and expansion of the indication as the ceramic bipolar may reduce the typical bipolar related complication

Introduction. Geometric variations of the hip joint can give rise to repeated abnormal contact between the femur and acetabular rim, resulting in cartilage and labrum damage. Population-based geometric parameterisation can facilitate the flexible and automated in silico generation of a range of clinically relevant hip geometries, allowing the position and size of cams to be defined precisely in three dimensions. This is advantageous compared to alpha angles, which are unreliable for stratifying populations by cam type. Alpha angles provide an indication of cam size in a single two-dimensional view, and high alpha angles have been observed in asymptomatic individuals. Parametric geometries can be developed into finite element models to assess the potential effects of morphological variations in bone on soft tissue strains. The aim of this study was to demonstrate the capabilities of our parameterisation research tool by assessing impingement severity resulting from a range of parametrically varied femoral and acetabular geometries. Methods. Custom made MATLAB (MathWorks) and Python codes. [1]. were used to generate bone surfaces, which were developed into finite element models in Abaqus (SIMULIA). Parametric femoral surfaces were defined by a spherical proximal head and ellipse sections through the neck/cam region. This method produced surfaces that were well fitted to bone geometry segmented from CT scans of cam patients and capable of producing trends in results similar to those found using segmented models. A simplified spherical geometry, including the labrum and acetabular cartilage, represented the acetabulum. Femoral parameters were adjusted to define relevant variations in cam size and position. Two radii (small and large cams) and two positions (anterior and superior cams) were defined resulting in four models. Alpha angles of these parametric femurs were measured in an anterior-posterior view and a cross-table lateral view using ImageJ (NIH). A further model was developed using a femur with a medium cam size and position, and the level of acetabular coverage and labrum length were varied. Bones were modelled as rigid bodies and soft tissues were modelled as transversely isotropic linearly elastic materials. With the acetabulum fully constrained in all cases, the femurs were constrained in translation and rotated to simulate flexion followed by internal rotation to cause impingement against the labrum. Results and Discussion. Models generated using the parametric approach showed that potential for tissue damage, indicated through local strain, was not predicted by measured alpha angle, but resulted from cam extent and position as defined by the ellipses. When variations were made to the acetabular rim, an increase in bone coverage had the greatest effect on impingement severity, indicated by strain in the cartilage labral-junction. An increase in labral length increased labral displacement, but had less effect on cartilage-labral strain. Patient specific models currently require full image segmentation, but there is potential to further develop these parametric methods to assess likely impingement severity based on a series of measures of the neck and acetabulum when three-dimensional imaging of patients is available

Objectives. Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) is a novel MRI-based technique with intravenous contrast agent that allows an objective quantification of biochemical cartilage properties. It enables a ‘monitoring' of the loss of cartilage glycosaminoglycan content which ultimately leads to osteoarthritis. Data regarding the longitudinal change of cartilage property after joint preserving hip surgery is sparse. We asked (1) if and how the dGEMRIC-index changes in patients undergoing open/arthroscopic treatment of femoroacetabular impingement (FAI) one year postoperatively compared to a control group of patients with non-operative treatment; (2) and if a change correlates with the clinical short term outcome. Methods. IRB-approved prospective comparative longitudinal study of two groups involving a total of 61 hips in 55 symptomatic patients with FAI. The ‘operative' group consisted of patients that underwent open/arthroscopic treatment of their pathomorphology. The ‘non-operative' group consisted of conservatively treated patients. Groups were comparable for preoperative radiographic arthritis (Tönnis score), preoperative HOOS- and WOMAC-scores and baseline dGEMRIC indices. All patients eligible for evaluation had preoperative radiographs and dGEMRIC scans at baseline and repeated dGEMRIC scans using the same scanner and protocol. (1) dGEMRIC indices of femoral and acetabular cartilage were assessed separately on the initial and follow-up dGEMRIC scans. Radial images were reformatted from a 3D T1 map for measurements. Regions of interest were placed manually peripherally and centrally within the cartilage based on anatomical landmarks at the 12 ‘hour' position of the clcok-face with the help of radial high-resolution PD-weighted MR images. (2) Patient-reported outcome was evaluated at baseline and at 1 year follow-up: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Hip disability and Osteoarthritis Outcome Score (HOOS). Statistical analysis included Student's t-Tests, Mann-Whitney U-tests and Wilcoxon signed-rank tests (p<0.05). Results. On the acetabular side, the dGEMRIC index decreased significantly (p<0.05) in 17/20 (85%) zones respectively in 21/24 (88%) of femoral zones in the operated group [Fig. 1]. In the non-operative group, no acetabular zone and 2/24 (8%) femoral zones presented with a significant drop [Fig. 2]. After one year the WOMAC and the HOOS scores significantly improved (58±42 to 33±42; p= 0.007 respectively 63±16 to 74±18; p= 0.028) for the operative group, while there was no change (55±45 to 48±50; p= 0.825 respectively 63±14 to 66±19; p= 0.816) for the non-operative group. Discussion. Interestingly joint-preserving surgery for FAI led to a decline in biochemical cartilage properties on MRI at a one year follow-up despite the significant improvement of patient outcome. This short-term phenomenon was described after periacetabular osteotomy for correction of hip dysplasia in literature with a normalization of the dGEMRIC values at 2 years

The first case was that of an 89-year-old woman with advanced dementia. After falling onto the left hip, she was admitted to the emergency room. Standard x-rays revealed an unstable intertrochanteric fracture. Closed reduction and internal fixation was performed using the long PFNA with a 105-mm helical blade, the second patient treated with this implant in our series. The operation was performed by an attending surgeon who was experienced with treatment of trochanteric fractures with intramedullary devices. Six weeks later the patient presented again with severe pain after she had fallen onto her left hip for a second time. Follow-up x-rays showed a perforation of the helical blade through the cortex of the femoral head after a shortening of the femoral neck by 2 cm. CCD angle was still 129 degrees, and there were no radiological signs of rotational displacement. The acetabular cartilage appeared intact. At her second operation, a replacement of the blade was performed using a shorter 95-mm implant. Postoperatively the patient was again mobilized under full weight bearing, and at 12 weeks follow-up, we found cut through again, we replaced hip with biopolar hemiarthroplasty

Introduction. Total hip arthroplasty (THA) is the most common surgery performed for complications of bipolar arthroplasty. The present study evaluated the functional results and complications associated with this surgery. Patients and Methods. Forty eight hips (48 patients) who had conversion of bipolar arthroplasty to THA between 1998 June and 2013 June, and who were followed-up for more than one year were evaluated. Twenty one hips had conversion surgery to THA using a Fitmore cup with metal-on-metal articulation (28 mm head). Six hips had surgery using the SecurFit cup and three hips, using the Lima LTO cup with ceramic-on-ceramic articulation (28 mm or 32 mm head). Eighteen hips had surgery using a large head metal-on-metal bearing: –MMC (seven hips), ACCIS (six hips) and Magnum (five hips). The average time of follow-up duration was 3.9 years (range, 1.0–11.3). There were 22 men and 26 women between the ages of 28 and 80 years (average, 68.9 years) at the time of conversion surgery. Conversion arthroplasty was performed for acetabular erosion without femoral stem loosening in 19 hips, acetabular cartilage erosion with femoral stem loosening in 13 hips, periprosthetic fracture in 12 hips, and recurrent dislocation in four hips. Results were evaluated using Harris hip score (HHS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score. The radiographs were analyzed for evidence of acetabular and femoral osteolysis or loosening. The complications were evaluated. Results. The time interval between hemiarthroplasty and conversion total hip prosthesis was 6.7 years on average (range, 5 months to 12 years). Pain was the leading sign in all patients. Average HHS improved from 42 preoperatively (range, 34–67) to 86 (range, 65 – 97) postoperatively. The average total WOMAC score improved from 47 (range, 32–67) to 22 (range, 9–44) postoperatively. All the patients operated for groin pain reported significant improvement in their symptoms. Radiological evaluation showed good bony ingrowth and stability of all the femoral components. None of the acetabular component showed migration, loosening, wear, or osteolysis at last follow-up. Complications occurred in five hips. One dislocation and one recurrent dislocation were encountered in isolated acetabular revision hips; whereas one single dislocation, one recurrent dislocation, and one trochanteric nonunion occurred in the hips with revision of both components. All dislocations were occurred in hips with a femoral head size of 28 mm. Dislocations were managed by closed reduction, and none of the patients required revision for dislocation. Conclusions. Conversion THA after symptomatic bipolar arthroplasty can offer reliable pain relief and functional improvement. The perioperative complications approximate those of revision THAs

[Background]. Bipolar hemiarthroplasty (following BHA) have historically had poor results in patients with idiopathic osteonecrosis of femoral head (OFNH). However, most recent report have shown excellent results with new generation BHA designs that incorporate advances in bearing technology. These optimal outcomes with bipolar hemiarthroplasty will be more attractive procedure for young patients who need bone stock for future total arthroplasty. The purpose of the current study was to evaluate the clinical and radiographic finding of this procedure for the treatment of OFNH at our institution after 7-to 21years follow-up. [Subjects and Methods]. We retrospectively reviewed a consecutive series of 29 patients (40 hips) who underwent primary bipolar hemiarthroplasty for ION (36 hips with stage III and 4 hips with stage IV) with a cementless femoral component between 1992 and 2006. Osteonecrosis was associated with corticosteroid use (23 patients), alcohol (16 patients), idiopathic (one patients). The mean follow-up duration was approximately 12 (range 7 to 21) years. Patients were evaluated according to the Japan Orthopaedic Association (JOA) hip score. We evaluate osteolysis and bone response of acetabulum or femur, and migration distance of outer head were calculated at the latest follow-up. Kaplan-Meier survivorship rate was investigated to examine implant failure rate. [Results]. The average the Japan Orthopedic Association (JOA) hip score significantly improved from 53.9±16.0 points (preoperative) to 89.6±8.0 points (final follow-up). At the time of the final follow-up, one patients (one hips) had undergone revision to total hip arthroplasty because of groin pain without mechanical failure and migration. The rate of implant survival, with revision because of any reason as the end point, was 100% for femoral components and 97.5% for bipolar head components at a average 12 years (139.9±51.1 months) respectively. A complication that include dislocation and disassembly was not occurred in this study group. Radiographically, all cases is acquired bone ingrowth fixation. Stress shielding of femoral-component was observed 13 cases (32.5%). No femoral-component loosening and osteolysis of femur and acetabular was occurred at final follow-up. Bipolar head shift greater than 2mm is 3cases (7.5%) at final follow-up point, but progressive outer head migration was not occurred (0 %). [Discussion]. Survivorship determined in our study was more favorable than that of previous studies. The our long-term postoperative clinical results of up to Stage3 without the acetabular cartilage surface damage showed more superior to those previously reported for BHA. Recently, larger oscillation angle, proximal porous coating, highly cross-linked PE liner, improved these BHA design concept. Thus, the current BHA can be one of reliable procedure. Based on our results, The BHA for stage III ION, with appropriate surgical indications, may be a good option

Background. Femoro-acetabular impingement (FAI) is increasingly recognised as a cause of mechanical hip symptoms in sportspersons. In femoro-acetabular impingement abnormal contact occurs between the proximal femur and the acetabular rim during terminal motion of the hip as a result of abnormal morphologic features involving the proximal femur (CAM) or the acetabulum (Pincer) or both (Mixed) leading to lesions of acetabular labrum and the adjacent acetabular cartilage. It is likely that it is a cause of early hip degeneration. Ganz developed a therapeutic procedure involving trochanteric flip osteotomy and dislocation of the hip, and have reported good results. We have developed an arthroscopic technique to reshape the proximal femur and remove prominent antero-superior acetabular rim thereby relieving impingement. Methods. Twelve patients presented with mechanical hip symptoms and had demonstrable cam-type (eight patients) or mixed (four patients) FAI on radially-reconstructed MR arthrography, were treated by arthroscopic femoral osteochondroplasty and acetabular rim resection if indicated. All patients were competing at the highest level in their respective sport (football, rugby and athletics). All patients were followed up and post-operative Non-Arthritic Hip Scores (NAHS, maximum possible score 100) compared with pre-operative NAHS. Results. There were no complications. All patients were asked to be partially weight-bearing with crutches for four weeks and most returned to training within six weeks. All of them returned to competitive sports by 14 weeks. Symptoms improved in all patients, with mean NAHS improving from 72 pre-operatively to 97 at 3 months. Conclusion. Arthroscopic reshaping to relieve FAI is feasible, safe and reliable. However it is technically difficult and time-consuming. The results are comparable to open dislocation and debridement, but avoid the prolonged disability and the complications associated with trochanteric flip osteotomy. This is important in elite athletes as they can return to training and competitive sports much quicker with less morbidity

Introduction:. Most cases of hip osteoarthritis (OA) are believed to be caused by alterations in joint contact mechanics resulting from pathomorphologies such as acetabular dysplasia and acetabular retroversion. Over the past 13 years, our research group has focused on developing approaches for patient-specific modeling of cartilage and labrum in the human hip, and applying these approaches to study hip pathomorphology. The long term objective is to improve the understanding of the etiology of OA related to hip pathomorphology, and to improve diagnosis and treatment. The objectives of this presentation are to provide a summary of our subject-specific modeling approach, and to describe the results of our analysis of hips from three populations of subjects: normal, traditional dysplastic, and retroverted. Methods:. A combined experimental and computational protocol was used to investigate contact mechanics in ten normal subjects (normal center edge angles (CEA), no history of hip pain), ten subjects with hip pain secondary to acetabular dysplasia (CEA less than 25°), and ten patients with a radiographic crossover sign, pain and clinical exams consistent with acetabular retroversion. CT arthrography was used to image cartilage and bone. Volumetric image data were segmented and discretized, and subject-specific finite element models were produced using validated methods [Fig. 1]. Boundary and loading conditions were obtained from instrumented implant and gait data. Contact mechanics were evaluated on the acetabular cartilage and labrum. Labrum contact area and peak contact stress were evaluated. Cartilage contact area, peak and average contact stress were evaluated in six anatomical regions in the acetabulum. Results:. Hip contact patterns were subject-specific, but distinct patterns emerged in the groups. Dysplastic hips had a larger contact area in the lateral region of the acetabulum, while normal hips demonstrated a more distributed contact pattern. The labrum in dysplastic hips supported significantly more load than the labrum in normal hips in all activities [Fig. 2]. Contact in retroverted hips tended to be focused medially and superiorly [Fig. 3]. Retroverted subjects had smaller contact stress and area in most regions. Discussion:. The differences in labrum mechanics between the normal and dysplastic groups provide clear support for the mechanical importance of the acetabular labrum in dysplastic hips. There were only minor differences in cartilage contact stress and area between normal and dysplastic groups, because of a lateral shift in the location of contact and subsequent loading on the acetabular labra in the dysplastic hips. The larger labrum load support and contact area in dysplastic hips indicates that the labrum compensates for the shallow acetabula. Clinically, this may account for the pattern of OA onset in dysplastic hips. The results for the retroverted group do not support the commonly held belief that concentrated posterior loading in retroverted hips leads OA because there were lower contact stresses and areas in the posterior regions of retroverted hips. Further, these results suggest that rim trimming may be appropriate for retroverted hips. The preferred surgery likely depends on subtle patient specific aspects of hip pathoanotomy in both retroverted and dysplastic hips