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Background and purpose — The most frequent cause of arthroplasty failure is aseptic loosening—often induced by particles. Abrasion material triggers inflammatory reactions with lymphocytic infiltration and the formation of synovial-like interface membranes (SLIM) in the bone–implant interface. We analyzed CD3 quantities in SLIM depending on articulating materials and possible influences of proven material allergies on CD3 quantities. Patients and methods — 222 SLIM probes were obtained from revision surgeries of loosened hip and knee arthroplasties. SLIM cases were categorized according to the SLIM-consensus classification and to the particle algorithm. The CD3 quantities were analyzed immunohistochemically, quantified, and correlated to the particle types. Results — Metal–metal pairings showed the highest CD3 quantities (mean 1,367 counted cells). CD3 quantities of metal–polyethylene (mean 243), ceramic–polyethylene (mean 182), and ceramic–ceramic pairings (mean 124) were significantly smaller. Patients with contact allergy to implant materials had high but not statistically significantly higher CD3 quantities than patients without allergies. For objective assessment of the CD3 response as result of a pronounced inflammatory reaction with high lymphocytosis (adverse reaction), a defined CD3 quantity per high power field was established, the “CD3 focus score” (447 cells/0.3 mm2, sensitivity 0.92; specificity 0.90; positive predictive value 0.71; negative predictive value 0.98). Interpretation — The high CD3 quantities for metal–metal pairings may be interpreted as substrate for previously described adverse reactions that cause severe peri-implant tissue destruction and SLIM formation. It remains unclear whether the low CD3 quantities with only slight differences in the various non-metal–metal pairings and documented contact allergies to implant materials have a direct pathogenetic relevance.

In the histopathological particle algorithm polyethylene (PE) particles with maximum lengths of more than 100μm - called PE supramacroparticles - are identified exclusively for knee joint and hip prostheses. However, a definitive characterisation, detection in all joint localisations and a causal clarification of the pathogenesis are lacking. In this study a total of 175 SLIM (synovial-like interface membrane) cases with PE supramacroparticles of knee joint prostheses (n=89), hip joint prostheses (n=44), ankle joint prostheses (n=36) and prostheses in three localisations of the upper extremities (n=6) were systematically investigated. The arithmetic mean of the particle length varied greatly within the prosthesis types. This had a significant positive correlation with the prosthesis lifetime and negative correlation with the date of implantation. It can be concluded that both the lifetime and the time of implantation have an influence on the particle length. The prostheses with supramacroparticulate damage moreover showed a clearly reduced survival rate compared with other data published on the prosthesis lifetime. The material wear therefore could not be attributed solely to the usual fatigue factors. Since loosening of the prostheses, decentring of the PE components or damage to the PE inlay existed in all cases, mechanical dysloading seems to be the most probable cause of PE supramacroparticle genesis. Due to the striking length and for demarcation from PE macroparticles, the term supramacroparticulate PE is proposed for a length of more than 100μm. In the extended histopathological particle algorithm supramacroparticulate PE has been included in the macroparticles category and should be taken into account and interpreted causally in histopathological diagnostics of joint prosthesis failure.

Background: Total hip arthroplasty without cement is frequently performed in young active patients, but only limited outcomes data are available after durations of follow-up of more than fifteen years. Methods: We retrospectively evaluated the clinical and radiographic results of a consecutive series of 154 total hip arthroplasties (in 141 patients) performed with an uncemented grit-blasted straight tapered titanium femoral stem combined with a threaded socket in patients under the age of fifty-five years. The median duration of follow-up was seventeen years. Clinical results were evaluated with use of the Harris hip score. The canal fill index was used as the criterion to determine the adequacy of stem sizing. Kaplan-Meier survivorship analysis was performed to predict long-term outcomes. Results: The stem was undersized, with a canal fill index of ≤80%, in forty-one hips (27%). Late aseptic loosening of the stem occurred in four femora, and the femoral component was undersized in all four. These four stems were stable for ten years and then underwent progressive subsidence, which was associated with pain. Five stems were revised because of a late postoperative periprosthetic fracture following trauma. Localized proximal femoral osteolysis was seen in seven hips without signs of loosening. Survivorship of the stem with revision for any reason as the end point was estimated to be 90% (95% confidence interval, 87% to 97%) at twenty years. Survivorship with aseptic loosening as the end point was estimated to be 95% (95% confidence interval, 91% to 99%) at twenty years. Sixty-seven (44%) of the threaded uncemented acetabular components were revised during the follow-up period. Conclusions: After a minimum duration of follow-up of fifteen years, the survival of this type of femoral component is excellent in individuals younger than fifty-five years. The main mode of stem failure was a periprosthetic fracture due to trauma, or late aseptic loosening in a small percentage of the hips in which the femoral implant was undersized. The high rate of failure of the acetabular components was attributable to a poor design that is no longer in use. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

New prosthesis designs should provide either superior function or durability. Before long time follow up studies are started it should at least prove its effectiveness in clinical outcomes. Therefore we have studied the early clinical results of a new mobile bearing total knee prosthesis (e.motion; Aesculap) in comparison with our established fixed-bearing device (PFC; DePuy) in a matched-pair analysis.About 30 consecutive patients received the new mobile bearing device and were matched with patients who received the PFC prosthesis according to age, gender, weight, axis and preoperative AKS-score. Outcomes were measured using the scores that are routinely documented in our arthroplasty register namely the American Knee Society Score (AKSS), the Oxford Knee Score (OKS), Functional Questionnaire of Hannover for Osteoarthritis (FFbH-OA), range of motion (ROM) and knee pain before and 2 years after the operation.No statistical differences could be found neither preoperative nor postoperative. Nevertheless the mobile bearing device had a slightly better ROM and function score.This new device proved to be at least as effective in early clinical outcome as the established fixed bearing prosthesis. It has to be awaited whether it is advantageous in the long run.

Nickel, chromium, and cobalt in stainless steel and Cobalt-chrome-molybdenum (CoCrMo) alloys may induce allergy. The objectives of this study were to evaluate surface coating regarding ion release, patch test reactivity, and arthroplasty performance. Materials and methods included patch test in 31 patients with metal allergy and 30 patients with no allergy to stainless steel and CoCrMo disks that are uncoated or coated by titanium nitride/zirconium nitride (TiN/ZrN). Assessment include atomic absorption spectrometry of released nickel, cobalt, and chromium from the disks after exposure to distilled water, artificial sweat and culture medium. Results showed that both coatings reduced the nickel and chromium release from stainless steel and CoCrMo disks and mostly the cobalt release from the disks (maximally 11.755 µg/cm 2 /5 d to 1.624 by Ti-N and to 0.442 by ZrN). Six of the 31 patients with metal allergy reacted to uncoated disks, but none reacted to the coated disks. The current authors report on exemplary patients with metal allergy who had symptom relief by revision with surface-coated arthroplasty. The authors concluded that the surface coating may prevent cutaneous and peri-implant allergic reactions. [ Orthopedics . 2016; 39(3):S24–S30.]

Inferior survival of cemented total hip arthroplasty has been reported after previous femoral osteotomy. We previously presented 5-15 years results of uncemented femoral stems for this subgroup of patients. The purpose of the present study was to re-evaluate that same patient group at 10-20 years follow-up.Forty-eight hips in 45 patients had undergone conversion THA for a failed intertrochanteric osteotomy of the hip after a mean of 12 years (2-33 years). Mean time of follow-up was 16 years (10-20 years).At the latest follow-up five patients had died (five hips), and one patient (one hip) remained lost to follow-up. Compared to the previous evaluation, one more patient required femoral revision for aseptic loosening giving a total of four patients (four hips) with femoral revision--one for infection and three for aseptic loosening of the stem. Survival of the stem was 91% at 15 and 20 years respectively; survival with femoral revision for aseptic loosening as an end point was 93%. The median Harris-Hip-Score at final follow-up was 76 points (previously 80 points). Radiolucent lines in Gruen zones 1 and 7 were present in 20 and 17% of hips, respectively. Radiolucencies in other zones were not detected. There was no radiographic evidence of femoral osteolysis, stress-shielding or loosening.The long-term results with this type of uncemented tapered titanium femoral component after proximal femoral osteotomy remain encouraging and compare favorably to those achieved in patients with regular femoral anatomy.

Femoral defects often make it difficult to achieve sufficient fixation of the stem during revision surgery. No clinical studies comparing modular stems are available and differentiated recommendations are rare. The aim of this study was to compare the fixation of different revision stems in an experimental and standardised manner. Segmental AAOS type I and III defects were reproduced in four femur pairs and two modular stems of different shape (cylindrical and conical) were implanted. Interfacial stem–bone movements were measured under axial torque application to analyze the stem fixation depending on defect extension. Both stems showed adequate fixation in AAOS type I defect. The defect extension significantly reduced the fixation of both implants. The fixation pattern changed significantly for the cylindrical-shaped stem but was maintained for the conical-shaped stem. Shape as well as the extension of femoral defect have an impact on primary fixation. A type I defect seems to be bridgeable for both stems albeit in a different way. In contrast, stem-demanding activities during the healing phase have to be avoided for the conical-shaped stem in a type III defect, whereas the cylindrical-shaped stem has already ceased to be sufficiently stable in this case.

Inferior survival of cemented total hip arthroplasty has been reported after previous femoral osteotomy. The purpose of this study was to evaluate the long-term survival of uncemented stems after femoral osteotomy. Forty-eight hips in 45 patients had undergone conversion THA for a failed intertrochanteric osteotomy of the hip after a mean of 12 years (2–33 years). Mean time of follow-up was 11 years (5–15 years). At follow-up, two patients (three hips) had died, and one patient (one hip) was not located. Three patients (three hips) underwent femoral revision—one for infection and two for aseptic loosening of the stem. Survival of the stem was 94% at 10 years, and survival with femoral revision for aseptic loosening as an end point was 96%. The median Harris Hip Score at follow-up was 80 points. Radiolucent lines in Gruen zones 1 and 7 were present in 14 and 18% of hips, respectively. Radiolucencies in other zones were not detected. There was no radiographic evidence of femoral osteolysis, stress-shielding or loosening. The results with this type of uncemented tapered titanium femoral component after proximal femoral osteotomy are encouraging and compare to those achieved in patients with regular femoral anatomy.

Bone resorption in the proximal femur is commonly seen after total hip arthroplasty (THA). With dual energy X-ray absorptiometry (DXA), the amount of bone mass (BMD) after implantation of a total hip stem can be precisely determined. However, prospective evaluation of the change of bone mass around the stem is only available for selected stems and short-term follow-up (up to 36 months). We analyzed BMD in patients who had undergone uncemented THA by DXA. Only patients with good clinical outcome (Merle d' Aubigné score12) were included to obtain normative data for regular bone response. Two separate studies were performed: a prospective longitudinal study over 84 months with baseline values acquired within the first postoperative week (group A) (n = 26 patients) and a separate cross-sectional study, median follow-up 156 (124-178) months (group B) (n = 35 patients). Regions of interest were defined according to Gruen (ROI 1-7) and as net average ROI (net avg) for the periprosthetic femoral bone. After the initial remodeling process (12 months), BMD was compared to the 84-month (longitudinal) and the 156-month (cross-sectional) follow-up values to determine long-term periprosthetic changes of bone mineral density. The longitudinal study (group A), after the initial bone remodeling, showed no relevant further bone loss for women and men with BMD values 1.19 +/- 0.15 and 1.40 +/- 0.19, respectively, 12 months (women 89.8%, men 93.6%), and 1.19 +/- 0.13 and 1.36 +/- 0.18, respectively, after 84 months (women 90.0%, men 91.3%) (P = 0.98, P = 0.08,) respectively. The distribution of the BMD around the stem changed during the first 12 months. The ROIs around the proximal stem (ROI 1 and 7) showed the lowest absolute values at the 12-month follow-up and BMD in ROI 7 decreased most during the further follow-up until 84 months. The cross-sectional study (group B) showed no significant difference in BMD (net avg) values at a median of 156 months follow-up compared to the 12-month values (group A) (women: P = 0.77, men: P = 0.44). Initial BMD, implant diameter, and body mass index did not influence BMD loss (net avg) in this study, whereas age showed a weak correlation with BMD loss. The results show that after the initial remodeling process, no relevant further bone loss (net avg) occurs up to 84 months postsurgery, and values after a median of 156 months are similar. Normative long-term changes in the periprosthetic bone can be demonstrated in defined ROIs after implantation of a tapered corundum-blasted titanium stem with a good clinical result.

Cartilage-derived retinoic acid-sensitive protein (CD-RAP), also referred to as melanoma-inhibiting activity (MIA), is detected physiologically only in cartilage tissue and pathologically in malignant melanoma. Recent studies indicated that this protein might be useful as a marker for altered joint metabolism or damage. The purpose of this study was to evaluate whether there is any correlation between the degree of cartilage degradation and levels of this protein. In a prospective cross-sectional study, synovial fluid samples were obtained from 67 consecutive patients undergoing surgery of the knee joint. The degree of cartilage degradation was determined intraoperatively using the Outerbridge and Noyes classifications. MIA/CD-RAP was measured by a commercially available enzyme-linked immunosorbent assay (ELISA). The marker levels were compared against the Outerbridge and Noyes classifications and the correlation coefficients were calculated. At advanced stages of cartilage degradation, there were decreased synovial fluid levels of MIA/CD-RAP. The correlation coefficients were -0.449 and -0.418 for the Outerbridge and Noyes classifications, respectively, with large 95% confidence intervals. While the physiological function of MIA/CD-RAP is still unclear, the results indicate that MIA/CD-RAP levels depend on the degree of cartilage degradation. Despite the high interindividual variations, MIA/CD-RAP might be useful as a marker to monitor degenerative joint lesions.

In 2005, a 60-year-old woman suffering from osteoarthritis received a total knee replacement (TKA) (e.motion, BBraun Aesculap, Tuttlingen, Germany) in another hospital. The prosthesis was implanted using antibiotic-loaded cement. Postoperatively, she suffered reduced mobility (E/F 0/10/60°) and her knee pain did not get better. In 2006, since the pain continued, a cemented retropatellar replacement was implanted. Radiological examination did not reveal any sign of a mechanical complication, but the pain still persisted and the patient was admitted to our hospital. Now, she complained of partly eczematous reactions (local itching, partial oozing, eczematous rashes), which appeared about half a year after the primary surgery (Figure 1). Blood counts including C-reactive protein test and bacteriological tests after joint aspiration virtually excluded a low-grade infection. A lymphocyte transformation test showed no increased values for metal ions (chromium, cobalt, nickel).

Treatment by continuous passive movement at home is an alternative to immobilisation in a cast after surgery for club foot. Compliance with the recommended treatment, of at least four hours daily, is unknown. The duration of treatment was measured in 24 of 27 consecutive children with a mean age of 24 months (5 to 75) following posteromedial release for idiopathic club foot. Only 21% (5) of the children used the continuous passive movement machine as recommended. The mean duration of treatment at home each day was 126 minutes (11 to 496). The mean range of movement for plantar flexion improved from 15.2 degrees (10.0 degrees to 20.6 degrees ) to 18.7 degrees (10.0 degrees to 33.0 degrees ) and for dorsiflexion from 12.3 degrees (7.4 degrees to 19.4 degrees ) to 18.9 degrees (10.0 degrees to 24.1 degrees ) (both, p = 0.0001) when the first third of therapy was compared with the last third. A low level of patient compliance must be considered when the outcome after treatment at home is interpreted.

Study design This investigation was aimed at characterizing anomalies and syndromes associated with Klippel-Feil syndrome in a large group of patients. The authors evaluated the clinical and radiographic features, documented the associated anomalies, and registered the type of treatment. Objective The anomalies or syndromes and the development of scoliosis were correlated to the type of Klippel-Feil syndrome. Material and methods In a cross-sectional study, the authors reviewed data from 57 patients with Klippel-Feil syndrome treated over 25 years at the Department for Orthopedics of the University of Heidelberg. The patients (17 males and 40 females; average age of the first contact, 12 years) were classified into three types according to the description of Feil in 1919. Results Klippel-Feil syndrome Type I (fusion of cervical and upper thoracic vertebra with synostosis) and Type II (isolated cervical spine) corresponded to 40% and 47% of patients, respectively. Type III (cervical vertebra associated with lower thoracic or upper lumbar fusion) was displayed in 13% of the patients only. The authors found a variety of combinations of Klippel-Feil syndrome and other anomalies in the patients examined in this study, with 67% of the patients characterized by an association with other disorders or syndromes. Of the patients, 70% showed scoliosis. Its degree depended on the type of Klippel-Feil syndrome. Scoliosis in Type I correlated with 31 degrees (Cobb angle), in Type III with 23 degrees, and in Type II with 9 degrees only. Thus, Type II, with isolated cervical fusion, shows a low risk for scoliosis. Conclusion This study increases knowledge of a wide range of anomalies and syndromes identified in association with Klippel-Feil syndrome. A special finding of the study was a correlation between the degree of scoliosis and Klippel-Feil syndrome Types I, II, and III.

Continuous passive motion has been shown to be effective in the conservative treatment of idiopathic club foot. We wished to determine whether its use after operation could improve the results in resistant club feet which required an extensive soft-tissue release. There were 50 feet in the study. Posteromedial lateral release was performed in 39 feet but two were excluded due to early relapse. The mean age at surgery was eight months (5 to 12). Each foot was assigned a Dimeglio club foot score, which was used as a primary outcome measure, before operation and at 6, 12, 18 and 44 months after. Nineteen feet were randomly selected to receive continuous passive motion and 18 had standard immobilisation in a cast. After surgery and subsequent immobilisation in a cast the Dimeglio club foot score improved from 10.3 before to 4.17 by 12 months and to 3.89 at 48 months. After operation followed by continuous passive motion the score improved from 9.68 before to 3.11 after 12 months, but deteriorated to 4.47 at 48 months. Analysis of variance adjusted for baseline values indicated a significantly better score in those having continuous passive motion up to one year after surgery, but after 18 and 48 months the outcomes were the same in both groups.

Background: Some nickel (Ni) allergic patients develop complications following Ni-containing arthroplasty. In the peri-implant tissue of such patients, we had observed lymphocyte dominated inflammation together with IFN-γ and IL-17 expression. Objectives: To determine whether Ni stimulation of peripheral blood mononuclear cells (PBMCs) of such patients would lead to a different cytokine pattern as compared to Ni-allergic patients with symptom-free arthroplasty. Patients and Methods: Based on history and patch testing in 15 Ni-allergic patients (five without implant, five with symptom-free arthroplasty, five with complicated arthroplasty) and five non-allergic individuals, lymphocyte transformation test (LTT) was performed using PBMC. In parallel in vitro cytokine response to Ni was assessed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results: All 15 Ni-allergic individuals showed enhanced LTT reactivity to Ni (mean SI = 8.42 ± 1.8) compared to the non-allergic control group. Predominant IFN-γ expression to Ni was found both in the five allergic patients without arthroplasty and also in the five allergic, symptom-free arthroplasty patients. In contrast, in the five Ni-allergic patients with arthroplasty-linked complications a predominant, significant IL-17 expression to Ni was seen but not in patients with symptom-free arthroplasty. Conclusions: The predominant IL-17 type response to Ni may characterize a subgroup of Ni-allergic patients prone to develop lymphocytic peri-implant hyper-reactivity.

A periprosthetic femoral fracture after total hip arthroplasty is a serious but uncommon complication, and therefore difficult to analyze clinically in scientifically and statistically valid study samples. With the aim of preventing these fractures the purpose of this study was to investigate potential risk factors associated with cementless hip arthroplasty in a standardized laboratory setup. Additionally, we aimed to clarify if the treatment with a cementless hip stem is fraught with higher risk of periprosthetic fracture for older patients compared to younger patients.A biomechanical setup was developed to provide analysis on sixteen femoral specimens of different age. A cementless hip stem was implanted into the specimens and loads - representing hip contact forces - were applied under standardized conditions until fracture occurred. The femurs were divided into two age groups (70 andor=77 years of age).The elderly specimens fractured at significantly lower maximum forces (70: Fmax=5,308N;or=77: Fmax=2,519N; p0.01). Maximum fracture loads were found to correlate strongly with age (p=0.01), BMD (e.g. for the Ward's triangle: p0.01) and BMI (p=0.04).In patients with advanced age treated with cementless hip stems the risk of suffering a periprosthetic fracture is significantly higher. It increases in patients with an age of 80 years or older, a Ward's triangle BMD below 0.500 g/cm2 and a BMI33 kg/m2. Whereas one single factor must not be viewed as an exclusion criterion for a cementless hip stem treatment, cumulation of these factors should alert the orthopaedic surgeon.

Myoelectric prostheses have generally been provided for adolescent or adult patients. The availability of smaller-sized electric hands has enabled the introduction of myoelectric prostheses to preschool children, mainly in the Scandinavian countries. This study evaluates the acceptance of myoelectric prostheses in 41 children with unilateral upper limb deficiency between the ages of two and five years. The prosthesis was used for an average time of 5.8 hours per day. The level of amputation was found to influence the acceptance rate. Furthermore, prosthetic use training by an occupational therapist is related to successful use of the prosthesis. The general drop-out rate in preschool children is very low compared to adults. Therefore, infants can profit from myoelectric hand prostheses. Since a correct indication and an intense training program significantly influence the acceptance rate, introduction of myoelectric prostheses to preschool children should take place at specialised centres with an interdisciplinary team.

Patellofemoral complications following knee arthroplasty are a well-known problem. Patellar ischemia has been suspected to be causative for fracture, anterior knee pain, and patella component failure. The purpose of this study was to assess the influence of knee arthroplasty surgical dissection on patellar blood flow. Patellar blood flow was measured by means of intraosseous laser Doppler flowmetry (LDF) in 10 patients undergoing total knee arthroplasty by a standard medial parapatellar approach. The initial blood flow was 121.6 ± 114.7 AU. The signal significantly decreased by 71% (p = 0.0051) when the knee was flexed and lost the pulsatile signal pattern in 80%. After arthrotomy, the signal was 100.1 ± 120.3 AU in extension. The lowest signal was found in flexion and eversion of the patella (mean, 18 ± 10.7 AU) and all signals lost pulsatility. As compared to the initial values, completion of the soft tissue dissection did not lead to a significant change of the blood flow signal (121.3 ± 104.8; p = 0.6835). Flexion of the knee joint markedly reduced patellar perfusion. Standard medial parapatellar approach did not significantly change patellar blood flow. This study does not support the theory of postoperative patellar ischemia as a cause of anterior knee pain or patellofemoral problems. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1389–1394, 2007

After developmental dislocation of the hip, Perthes disease, bacterial coxitis, and other pediatric hip conditions, the femoral neck may develop short, with an overgrowth of the greater trochanter. Forty-four patients with trochanter overgrowth (47 hips) ages 6 to 17 years underwent surgery. Trochanteric epiphysiodesis was performed in 13 patients (group A), distal transfer of the greater trochanter in 24 patients (26 hips; group B), and femoral neck lengthening osteotomy in 7 patients (8 hips; group C). The mean follow-up time was 8.3 years. Clinical results were evaluated by the hip score according to Merle d'Aubigné. Radiological parameters were evaluated by 2 of the authors. Each operative method led to an improvement of clinical symptoms. In group A, no significant changes in the radiological parameters could be found. Groups B and C showed significant improvements in the radiological parameters. However, no difference was found between these 2 groups.

In the 1970s and 1980s, uncemented, threaded acetabular components with smooth surface treatment were widely used in continental Europe for arthroplasty of the hip to overcome the high rate of aseptic loosening in cemented hip arthroplasty in young patients. There were several reports on short- and intermediate-term results, but information on survival in the longer term is not available at present.In a consecutive series of 320 patients, 348 threaded cups with smooth surface treatment (221 Mecring and 127 Weill) had been implanted in combination with one type of uncemented stem. Patients were followed clinically and radiographically. The mean time of follow-up was 12.4 (range 10-15) years (Mecring 11.9 years, Weill 13.3 years).In 76 hips the acetabular component had been revised (Mecring 56, Weill 20): 7 hips for infection and 69 for aseptic loosening. Of the remainder, the cup had migrated in 55 hips, and 32 hips were awaiting revision. Survival at 14 years was 63.8% (95%CI: 52.5-75.0%) for the Mecring and 76.2% (95%CI: 65.6-86.7%) for the Weill component. Radiolucent lines were present in 59 hips (31.9%). The median Harris Hip Score at follow-up was 84 points (Mecring 85, Weill 82). Radiographic loosening did not correlate with clinical outcome.These results support the view that smooth, threaded acetabular components do not provide satisfactory long-term fixation and should be abandoned.

We followed the first 354 consecutive implantations of a cementless, double-tapered straight femoral stem in 326 patients. Follow-up was at a mean of 12 years (10 to 15). The mean age of the patients was 57 years (13 to 81). At follow-up, 56 patients (59 hips) had died, and eight (eight hips) had been lost to follow-up. Twenty-five hips underwent femoral revision, eight for infection, three for periprosthetic fracture and 14 for aseptic loosening. The overall survival was 92% at 12 years (95% CI 88 to 95). Survival with femoral revision for aseptic loosening as an endpoint was 95% (95% CI 92 to 98). The median Harris hip score at follow-up was 84 points (23 to 100). Radiolucent lines (< 2 mm) in Gruen zones 1 and 7 were present in 38 (16%) and 34 hips (14%), respectively. Radiolucencies in zones 2 to 6 were found in five hips (2%). The results for mid- to long-term survival with this femoral component are encouraging and compare with those achieved in primary cemented total hip arthroplasty. The high rate of loosening of the cup and the high rate of pain are, however, a source of concern.

In recent years, many biochemical markers were tested with the aim of developing a tool for the early detection and monitoring of osteoarthritis (OA). Apart from chondral markers, we also evaluated osseous markers from the synovial fluid to obtain more comprehensive information, and we compared the levels in relation to the severity of OA. In this prospective, cross-sectional study, synovial fluid samples were obtained from 73 patients with OA of the knee joint prior to operation and after the joint was flushed with 50 ml of normal saline. All patients underwent surgery and were classified in accordance with the Outerbridge and the Noyes classification. The measured biochemical markers included pyridinoline (PD), deoxypyridinoline (DPD), N-telopeptide (NTx), carboxyterminal propeptide of collagen-1 (PICP), matrix metalloproteinases (MMP-1 and MMP-3), and tissue inhibitor of MMPs (TIMP-1). The marker levels were normalized against the total protein content and were compared with the Outerbridge and the Noyes classification. For the majority of markers, the correlation coefficient was below r=0.3, with large 95% confidence intervals. The highest correlation coefficients were obtained from DPD and TIMP-1. In relation to the Outerbridge classification, DPD revealed high values only in stage IV. The overall results indicate that the majority of the tested markers are unspecific with regard to the different stages of OA. The two markers with the highest correlation coefficients showed no major sensitivity to detect OA at an initial stage. However, they might give additional information to clinical and radiological findings with regard to the severity of the disease.

We reviewed data from 57 patients (40 women) with Klippel-Feil syndrome to identify and characterize limb deficiencies. The cervical synostosis was classified according to the description of Feil (1919). Limb deficiencies were classified according to Henkel et al. (1978) and compared with the sclerotome theory of McCredie and Willert (1999). In a wide variety of combinations of Klippel-Feil syndrome (types I-III) and other anomalies, only 5 patients had a longitudinal upper limb deficiency (one arm or both arms). 4 patients had Klippel-Feil syndrome type II and 1 had type I. 4 patients had "longitudinal distal radial deficiencies", Henkel types 1, 2, 4 and 5 and 1 patient showed "longitudinal combined humero-ulna deficiencies" types 2 and 3 of both arms. The lower limb was not affected. The combination of Klippel-Feil syndrome and upper limb deficiency shows that the defect occurred between the 4th and 5th week of gestation. Sclerotome 6 was mainly affected in our study. In 4 of the 5 patients, the cervical fusion level and sclerotome level of the limb deficiency clearly or partly matched, whereas there was no agreement in 1 patient.

Pathological lumbar kyphosis occurs in approximately 8% to 20% of patients with myelomeningocele. During the past 4 years, nine patients with an average preoperative kyphosis of 152 degrees were surgically corrected. They had a short fusion and a long stabilization with Luque rod instrumentation using a technique described by Warner and Fackler (1993). The average degree of correction was 104 degrees and, on average, 2.5 vertebrae were resected. The average surgical time was 225 minutes, and blood loss averaged 635 ml. We saw two complications: one penetration of the distal part of the rod through the sacrum after 32 months, and a dislocation of the rods out of the first sacral foramen after 33 months. From our experience, this procedure is highly demanding, but effective. It should be limited to patients below the weight of 30 kg.

Congenital horizontal gaze paralysis is a rare disorder which may be associated with severe scoliosis of early onset. We present the clinical findings of two sisters with this syndrome. The additional finding of a unique pericentric inversion of chromosome 12 is considered to be incidental. Every child with congenital horizontal gaze paralysis should be evaluated for a possibly associated scoliosis. If present, a diagnosis of this presumably autosomal recessive syndrome can be made with appropriate treatment and genetic counseling.

The diagnosis of aseptic loosening in total hip arthroplasty is predominantly based on clinical and radiographic evaluation. Loosening is usually associated with increased bone resorption at the interface. In this study we wanted to evaluate the diagnostic value of bone markers in aseptic loosening. We compared 50 patients with proven component loosening during surgery with 50 age-, sex-, and implant-matched patients without clinical or radiological signs of loosening. We measured serum markers of bone formation (bone-specific alkaline phosphatase, osteocalcin [OC], procollagen type I propeptides) and bone resorption (collagen n-telopeptide [NTX], deoxypyridinoline [DPYD], pyridinoline [PYD]). We found significantly increased levels of NTX, DPYD, PYD, and OC in the loosening group. The other markers showed no significant difference between both groups. We conclude that determination of urinary crosslinks may offer a new and valuable diagnostic method in the detection of aseptic loosening in total hip arthroplasty.

We report on two families with the oculodentodigital (ODD) dysplasia syndrome, also called Meyer-Schwickerath syndrome. It represents a rare disorder characterized by eye and facial abnormalities causing a unique facial appearance. The phenotype of the young patients resembles those of identical twins. We found syndactyly mostly at the hands and, additionally, characteristic phalangeal aberrations, defects in teeth enamel, and trichosis. In the one family, the ODD dysplasia syndrome seemingly originated in a new mutation. The affected child was treated surgically in our clinic (syndactyly separation). In the other family, three patients (grandmother, mother, and granddaughter) were subjects of syndactyly separation. The aim of our surgeries was to separate the webbed fingers so there would be a normal spread and to improve the function and appearance of fingers. The ODD dysplasia syndrome correlates with the Hallermann-Streiff syndrome, or oculomandibulodyscephaly, which is characterized by a typical skull shape (brachicephaly with frontal brossing), a bird-like face, and eye abnormalities (congenital cataracts and microphthalmia).

In a prospective longitudinal study over 2 years and a separate cross-sectional study more than 5 years after operation, we analyzed periprosthetic bone mineral density (BMD) after cementless total hip arthroplasty (THA) (press-fit cementless Spotorno stem, Mecron threaded acetabular cup) by dual-energy X-ray absorptiometry (DEXA). BMD was analyzed in a longitudinal prospective study (n = 53 patients: 29 women, 24 men) and in a separate cross-sectional study (n = 23 patients: 13 women, 10 men) with good clinical outcome (Merle d' Aubigne score12). Regions of interest were defined according to Gruen (ROI 1-7) and as netto average ROI (NETAVG I) for the periprosthetic femur, and according to De Lee and Charnley (ROI I-III) and as NETAVG II for the periprosthetic acetabulum. BMD during follow-up was compared with immediate postoperative values of the affected limb. Mean precision error (CV%) was 2.6 +/- 0.5% for ROI 1-7 and 1.3 +/- 0.9% for ROI I-III. BMD significantly decreased in the periprosthetic femur and acetabulum during the first 3 months after operation. At the femur, BMD (NETAVG I) for women and men, respectively, was 92.4% and 87.5% at 6 months, then 89.4% and 96.2% at 2 years. ROIs around the proximal stem showed the lowest absolute values and decreased most during follow-up (to 79.9% ROI 1 and 68.2% ROI 7, respectively). Mineralization around the cup (NETAVG II), respectively, amounted to 81.1%, 82.6% at 6 months, then 80.1% and 93.8% at 2 years. The medially placed ROI II demineralized most (respectively, 72.1% and 76.7%). More than 5 years after THA, BMD in the femur showed little change, but decreased significantly to 76.4% and 79.1%, respectively, around the cup (NETAVG II). DEXA is a useful method for analyzing changes of mineralization around cup and stem of cementless THA. The results reflect the different stress on the periprosthetic bone after implantation of THA in defined ROIs, supporting earlier reported good clinical results of the Spotorno stem and increased loosening rate of threaded acetabular cups after 5 years.

Introduction CD4+CD25+/highCD127low/- regulatory T cells (Tregs) play a crucial role in maintaining peripheral tolerance. Data about the frequency of Tregs in rheumatoid arthritis (RA) are contradictory and based on the analysis of peripheral blood (PB) and synovial fluid (SF). Because Tregs exert their anti-inflammatory activity in a contact-dependent manner, the analysis of synovial membrane (SM) is crucial. Published reports regarding this matter are lacking, so we investigated the distribution and phenotype of Tregs in concurrent samples of SM, SF and PB of RA patients in comparison to those of osteoarthritis (OA) patients. Methods Treg frequency in a total of 40 patients (18 RA and 22 OA) matched for age and sex was assessed by flow cytometry. Functional status was assessed by analysis of cell surface markers representative of activation, memory and regulation. Results CD4+ T cells infiltrate the SM to higher frequencies in RA joints than in OA joints (P = 0.0336). In both groups, Tregs accumulate more within the SF and SM than concurrently in PB (P