Osteoporosis Remains Constant in Patients with Hemophilia-Long-Term Course in Consideration of Comorbidities.

INTRODUCTION: Patients with hemophilia (PWHs) suffer from an increased risk of osteoporosis. Multiple hemophilia and hemophilic arthropathy associated factors correlate with a low bone mineral density (BMD) in PWHs. The aim of this study was to assess the long-term development of BMD in PWH as well as to analyze potentially influencing factors. METHODS: A total of 33 adult PWHs were evaluated in a retrospective study. General medical history, specific-hemophilia-associated comorbidities, joint status using the Gilbert score, calcium level, and vitamin D level as well as at least two results of bone density measurements with a minimum range of 10 years per patient were taken into account. RESULTS: The BMD did not change significantly from one point of measurement to the other. A total of 7 (21.2%) cases of osteoporosis and 16 (48.5%) cases of osteopenia were identified. The two following significant correlations could be revealed: the higher the patients' body mass index, the higher their BMD (r = 0.41; p = 0.022). Moreover, a high Gilbert score came along with a low BMD (r = -0.546; p = 0.003). CONCLUSION: Even if PWHs frequently suffer from a reduced BMD, our data suggest that their BMD remains constant on a low level in the course of time. A risk factor of osteoporosis often found in PWHs is a vitamin D deficiency and joint destruction. Therefore, a standardized screening of PWHs on BMD reduction by collecting vitamin D blood level and assessing joint status seems appropriate.

Comparison of Radiofrequency-targeted Vertebral Augmentation With Balloon Kyphoplasty for the Treatment of Vertebral Compression Fractures: 2-Year Results.

STUDY DESIGN: A retrospective study. OBJECTIVES: The aim of this study was the evaluation of the safety and effectiveness of radiofrequency-targeted vertebral augmentation (RF-TVA) in comparison with balloon kyphoplasty (BK) for the treatment of acute painful vertebral compression fractures (VCFs) on the basis of matched pairs. SUMMARY OF BACKGROUND: Vertebroplasty and BK are the common surgical interventions for the treatment of VCF. Both are effective and safe but pose some risks such as adjacent fractures and cement leakage. In 2009, RF-TVA was introduced as an innovative augmentation procedure for the treatment of VCF. MATERIALS AND METHODS: A total of 192 patients (116 female; 51-90 y) with VCF (n=303) at 1 to 3 levels were treated with RF-TVA or BK. Functionality (Oswestry Disability Index), pain (visual analogue scale), vertebral height (anterior, middle), and kyphotic angle were evaluated over a 2-year period (postoperatively, 3-4 d, 3, 6, 12, and 24 mo). In addition, operating time and occurrence of cement leakage were recorded. RESULTS: Pain and functionality were significantly improved after both treatments. In both groups, there was an increase in the vertebral height and a decrease in the kyphotic angle, which remained relatively consistent during 24 months. The incidence of cement leakage was 9.4% (n=9) in the RF-TVA group and 24.0% (n=25) in the BK group. The mean operating time with radiofrequency kyphoplasty was 25.9±9.9 minutes, and with balloon kyphoplasty 48.0±18.4 minutes. CONCLUSIONS: RF-TVA is a safe and effective procedure for the treatment of vertebral compression fractures when compared with BK. Improvement in pain and functional scores after RF-TVA are durable through 24 months postprocedure and remained better than those after BK at long-term follow-up. Operating time for RF-TVA is shorter and the risk of cement leakage is lower. Both procedures provided similar results in vertebral height restoration and reduction in the kyphotic angle.

Implications of trauma and subsequent articulation on the release of Proteoglycan-4 and tissue response in adult human ankle cartilage.

The purpose of this study was to investigate the effects of trauma and subsequent articulation on adult human ankle cartilage subjected to an injurious impact. Trauma was initiated through impaction on talar cartilage explants. Articulation and loading were applied in a joint bioreactor over 5 consecutive days. The early (24 h) effects of impaction included a reduced chondrocytes viability (51% vs. 81% for non-impacted; p = 0.03), increased levels of apoptosis (43% vs. 27%; p = 0.03), and an increase in the histopathology score (4.4 vs. 1.7; p = 0.02) as compared to non-impacted cartilage explants. One of the key findings was that damage also stimulated the PRG4 release (2.2 vs. 1.5 µg/ml). Subsequent articulation for 5 days did not lead to further changes in tissue histopathology and cell viability, neither for injured nor non-injured samples. However, articulation led to an increased apoptosis in the injured samples (p = 0.03 for the interaction term). Articulation also caused a significant increase of PG/GAG release into the culture medium (p = 0.04) for both injured and non-injured samples; however, the synthesis of PG was not affected by articulation (p = 0.45) though the PG synthesis was higher in injured samples (p < 0.01). With regard to the PRG4 release, impacted samples continued to show higher amounts (p = 0.01), adding articulation led to a reduction (p = 0.02). The current study demonstrated that adult human talar cartilage increases both the PRG4 release and biosynthetic activity as an immediate cellular response to injury. Articulation played a less contributing role to biosynthesis and remodeling, behaving mostly neutral, in that no further damage emerged. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:667-676, 2017.

Thirteen year follow-up of a cementless femoral stem and a threaded acetabular cup in patients younger than fifty years of age.

PURPOSE: Compared to older patients undergoing total hip arthroplasty (THA) younger patients are considered to be more active, thereby exposing the implant to significantly higher loads over a much longer period of time. Additionally, cases of secondary osteoarthritis caused by hip dysplasia, femoral head necrosis or rheumatic diseases are much more frequent than among the average patient population. Therefore, durable implant fixation and low wear rates are extremely important to achieve good long-term implant survival in this group of patients. OBJECTIVE: The aim of this retrospective study was to evaluate the mid- to long-term survival of a cementless femoral stem (Zweymüller® SL stem) and a threaded cup (Bicon SL®) in patients younger than 50 years of age. METHODS: Therefore, a consecutive series of 100 patients (111 hips) aged 50 years or younger (range: 30 to 50 years) was analysed at a mean follow up of 13.5 years. Follow-up assessment included physical examination and radiographic workup. Hip disability osteoarthritis and outcome score (HOOS) and Harris hip score (HHS) were used to evaluate the pre- and post-operative functional outcome, respectively. Patient satisfaction with the surgical result was assessed by standardized questionnaires. RESULTS: The overall survival rate with any revision as endpoint was 96.8 % (95 % CI: 90.5 % to 98.9 %) at ten years. Gender, operation time and the occurence of osteolyses had no influence on joint function or patient satisfaction. We recorded an overall failure rate of 7.4 % (six cases). In four cases (5 %) the prosthesis had to be revised due to aseptic loosening of the cup after 12 years, eight years, 12 years and 11 years, in one case (1.2 %) recurrent luxation led to a revision operation (acetabular cup and head) after three years of primary implantation. In one case an implant failure was recorded (acetabular cup breakage after eight years of implantation). We recorded the occurence of asymptomatic radiolucent lines of the cup in 21 % and of the stem in 35 % in our series. The HOOS was influenced by the presence or abscence of radiolucent lines of the stem. Patients with radiolucent lines of the stem had a median HOOS score of (74 points) compared to those without radiolucent lines (89 points). Other factors, such as "diagnosis led to operation" and "previous operations" had no influence on the HHS and HOOS. CONCLUSION: Our study demonstrates excellent long-term survival of cementless femoral stem in combination with a threaded cup in young patients undergoing total hip arthroplasty.

Outcome Predictors in Prosthetic Joint Infections--Validation of a risk stratification score for Prosthetic Joint Infections in 120 cases.

Prosthetic joint infections are a major challenge in total joint arthroplasty, especially in times of accumulating drug resistancies. Even though predictive risk classifications are a widely accepted tool to define a suitable treatment protocol a classification is still missing considering the difficulty in treating the -causative pathogen antibiotically. In this study, we present and evaluate a new predictive risk stratification for prosthetic joint infections in 120 cases, treated with a two-stage exchange. Treatment outcomes in 120 patients with proven prosthetic joint infections in hip and knee prostheses were regressed on time of infection, systemic risk factors, local risk factors and the difficulty in treating the causing pathogen. The main outcome variable was "definitely free of infection" after two years as published. Age, gender, and BMI were included as covariables and analyzed in a logistic regression model. 66 male and 54 female patients, with a mean age at surgery of 68.3 years±12.0 and a mean BMI of 26.05±6.21 were included in our survey and followed for 29.0±11.3 months. We found a significant association (p<0.001) between our score and the outcome parameters evaluated. Age, gender and BMI did not show a significant association with the outcome. These results show that our score is an independent and reliable predictor for the cure rate in prosthetic joint infections in hip and knee prostheses treated within a two-stage exchange protocol. Our score illustrates, that there is a statistically significant, sizable decrease in cure rate with an increase in score. In patients with prosthetic joint infections the validation of a risk score may help to identify patients with local and systemic risk factors or with infectious organisms identified as "difficult to treat" prior to the treatment or the decision about the treatment concept. Thus, appropriate extra care should be considered and provided.

Polymicrobial infections reduce the cure rate in prosthetic joint infections: outcome analysis with two-stage exchange and follow-up ≥two years.

PURPOSE: Prosthetic joint infections (PJI) are a serious and challenging complication after total joint arthroplasty. According to the literature, most PJI are monomicrobial infections caused by gram-positive cocci. The number of polymicrobial PJI might be underrepresented in the literature and only limited data are available regarding the outcome of polymicrobial PJI. Our hypothesis was that polymicrobial PJI are associated with a reduced cure rate compared with monomicrobial PJI. METHODS: Routine clinical data were collected and analysed retrospectively as anonymised, aggregated data. A total of 77 consecutive patients with 77 confirmed PJI and proven infectious organism of the hip and knee joint treated within a two-stage exchange concept and a follow-up ≥ two years were investigated. Detection of the infectious organism was based on multiple microbiological cultures taken intra-operatively. Superficial wound swabs or swabs from sinus tracts were not taken into account. Data were grouped into polymicrobial and monomicrobial PJI. The main outcome variable was "definitively free of infection after two years" as published. Second, we considered several variables as potential confounders or as risk factors. RESULTS: A total of 42 men and 35 women with 46 infected total hip arthroplasties and 31 infected total knee arthroplasties were evaluated. In 37 (46.6 %) of our 77 patients a polymicrobial PJI could be detected. We found a significant association between polymicrobial PJI and the outcome parameter definitively free of infection after two years with an odds ratio (OR) of 0.3 [95 % confidence interval (CI) 0.1-1.0]. The rate of patients graded as definitively free of infection after two years was 67.6 % for polymicrobial infections vs. 87.5 % for monomicrobial infections. The American Society of Anesthesiologists (ASA) score (OR 0.4, 95 % CI 0.2-1.0, p = 0.062) was identified as a borderline significant covariable. CONCLUSIONS: Our data suggest that polymicrobial PJI might be underrepresented in the current literature. Additionally, the presence of multiple infectious organisms is associated with a reduced rate after two years with 67.6 vs 87.5 % for monomicrobial infections. Special attention and extra care should be considered for these patients.

Validation of the Charlson comorbidity index in patients undergoing revision total hip arthroplasty.

PURPOSE: The Charlson comorbidity index (CCI) was developed to quantify the influence of comorbidities on survival. The age-related CCI respects patients' age as an additional risk factor. There are several studies available based on administrative data regarding functional outcome, implant survival, resource use and length of hospital stay in patients undergoing primary total hip arthroplasty (THA). To date, there is a lack of knowledge regarding the correlation of the CCI and the age-related CCI in case of revision total hip arthroplasty (RTHA). OBJECTIVE: Our objective was to validate the influence of the CCI and age-related CCI in patients undergoing RTHA regarding complication rate, resource use implant survival and mortality rate. METHODS: Between October 2007 and November 2012, 142 consecutive patients undergoing RTHA were included in this retrospective study. Routine clinical data were collected and analysed as anonymized aggregated data. In accordance to CCI and age-related CCI the rate of complications (internal medical and surgical complications), the length of hospital stay and the need for ICU treatment and the mortality rate was evaluated. Kaplan-Meier survivorship was used to determine implant survival. RESULTS: Twenty-one patients (15%) had a low risk CCI, 59 patients (41%) a moderate risk CCI and 62 patients (44%) a high risk CCI. The mean follow-up was 27 months (range 24-70 months). In total, we recorded 57 complications (40%), of which 45 were surgical (79%) and 12 were internal medical complications (21%). Twenty-four patients (17%) had to undergo revision surgery. CCI and age-related CCI had no influence regarding implant survival. We recorded a significant influence of the age-related CCI in regard to the necessity of postoperative intensive care unit stay and the length of total hospital stay. Further we recorded a significant influence of the CCI and the age-related CCI regarding postoperative complications and internal complications, postoperative dislocation and the need for surgical revision. CONCLUSION: In summary, we conclude that the CCI and the age-related CCI are strong predictors regarding complication rate in patients undergoing RTHA. In a short- to mid-term follow-up, no influence on implant survival is detectable.

Comparison of balloon kyphoplasty with the new Kiva® VCF system for the treatment of vertebral compression fractures.

BACKGROUND: Vertebral compression fractures are common among the elderly, which is conditioned by osteoporosis. They cause back pain and limit the patient's activities. The Kiva® VCF Treatment System is a new device to treat vertebral compression fractures. Compared to other methods, the utilization of the Kiva System reduces the risk for complications and delivers improvements in back pain reduction and functionality. OBJECTIVES: Evaluation of safety and effectiveness of the Kiva System in comparison to balloon kyphoplasty on the basis of matched pairs. METHODS: 52 patients (47 - 89 years, 68 fractures) were treated with balloon kyphoplasty or with the new Kiva System. Back pain and impairment of motility were assessed preoperatively and 6 months postoperatively, with the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). The operation time and cement extravasation were recorded. Control radiographs were evaluated for new fractures and vertebral heights. RESULTS: Mean VAS values in both groups improved from preoperatively 87.6 ± 12.8 and 83.1 ± 14.9 to 10.8 ± 20.8 and 24.6 ± 11.0 6 months after the treatment. The improvement after 6 months in the Kiva group was significantly better than in the balloon kyphoplasty group (P < 0.0001). Mean ODI scores in both groups also improved from 68.7% ± 15.8% in the Kiva group and 80.6% ± 8.6% in the balloon kyphoplasty group preoperatively to 24.8 ± 18.6% and 33.2 ± 6.3% 6 months after treatment. The mean operation time for the Kiva group was 12.7 ± 3.7 minutes per vertebra and cement leakage occurred in 6 patients. The mean operation time for the balloon kyphoplasty group was 34.1 ± 7.0 minutes per vertebra and cement leakage occurred in 8 patients. Anterior and mid vertebral height in the Kiva group increased from preoperatively 21.06 ± 7.44 mm and 18.36 ± 5.64 mm to postoperatively 22.41 ± 7.14 mm and 20.41 ± 6.00 mm. Anterior and mid vertebral height in the balloon kyphoplasty group increased from preoperatively 21.68 ± 2.06 mm and 21.97 ± 1.78 mm to postoperatively 25.09 ± 2.54 mm and 25.29 ± 2.10 mm. Vertebral height restoration could be therefore maintained with both procedures for 6 months. In the Kiva group 2 cases of nonadjacent fractures and one case of adjacent fractures were observed. In the balloon kyphoplasty group 9 cases of adjacent, as well as 5 cases of nonadjacent, fractures were observed. In the Kiva group significant fewer fractures occurred. LIMITATIONS: The study includes only 26 patients for each procedure, which were compared on the basis of matched pairs. CONCLUSION: The Kiva System appears to be a safe and effective procedure for the treatment of vertebral compression fractures. Six months after treatment with the Kiva System, better VAS values than the values after the treatment with balloon kyphoplasty were recorded. Reduction in functional impairment was as successful as it was after balloon kyphoplasty. Vertebral height restoration was observed in both groups, which was sustained for 6 months. The risk of cement extravasation during the Kiva Treatment is nearly the same as in balloon kyphoplasty; however, it requires a shorter operation time and produces less new fractures.

Three-dimensional computer-assisted navigation for the placement of cannulated hip screws. A pilot study.

PURPOSE: Medial femoral neck fractures are common, and closed reduction and internal fixation by three cannulated screws is an accepted method for the surgical treatment. Computer navigation for screw placement may reduce fluoroscopy time, the number of guidewire passes and optimise screw placement. METHODS: In the context of a sawbone study, a computer-assisted planning and navigation system based on 3D-imaging for guidewire placement in the femoral neck was tested to improve screw placement. Three screws were inserted into 12, intact, femoral sawbones using the conventional technique and into 12, intact, femoral sawbones guided by the computer-based navigation system. Guidewire and subsequent screw placement in the femoral neck were evaluated. RESULTS: Use of the navigation system resulted in a significant reduction of the number of drilling attempts (p≤0.05) and achieved optimised accuracy of implant placement by attaining significantly better screw parallelism (p≤0.05) and significantly enlarged neck-width coverage by the three screws (p≤0.0001). Computer assistance significantly increased the number of fluoroscopic images (p≤0.001) and the operation time (p≤0.0001). CONCLUSIONS: Three-dimensional computer-assisted navigation improves accuracy of cannulated screw placement in femoral neck while increasing the number of fluoroscopic images and operation time. Additional studies including fractured sawbones and cadaver models with the goal of reducing operation time are indispensable before introduction of this navigation system into clinical practice.

CRP and leukocyte-count after lumbar spine surgery: fusion vs. nucleotomy.

BACKGROUND: Despite the fact that C-reactive protein (CRP) levels and white blood cell (WBC) count are routine blood chemistry parameters for the early assessment of wound infection after surgical procedures, little is known about the natural history of their serum values after major and minimally invasive spinal procedures. METHODS: Pre- and postoperative CRP serum levels and WBC count in 347 patients were retrospectively assessed after complication-free, single-level open posterior lumbar interlaminar fusion (PLIF) (n = 150) for disc degeneration and spinal stenosis and endoscopically assisted lumbar discectomy (n = 197) for herniated lumbar disc. Confounding variables such as overweight, ASA classification, arterial hypertension, diabetes mellitus, and perioperative antibiotics were recorded to evaluate their influence on the kinetics of CRP values and WBC count postoperatively. RESULTS: In both procedures, CRP peaked 2-3 days after surgery. The maximum CRP level was significantly higher after fusion: mean 127 (SD 57) (p < 0.001). A rapid fall in CRP within 4-6 days was observed for both groups, with almost normal values being reached after 14 days. Only BMI > 25 and long duration of surgery were associated with higher peak CRP values. WBC count did not show a typical and therefore interpretable profile. CONCLUSION: CRP is a predictable and responsive serum parameter in postoperative monitoring of inflammatory responses in patients undergoing spine surgery, whereas WBC kinetics is unspecific. We suggest that CRP could be measured on the day before surgery, on day 2 or 3 after surgery, and also between days 4 and 6, to aid in early detection of infectious complications.

Soluble ions more than particulate cobalt-alloy implant debris induce monocyte costimulatory molecule expression and release of proinflammatory cytokines critical to metal-induced lymphocyte reactivity.

Aseptic osteolysis has been associated with excessive immune reactivity to particulate implant debris; however, innate and adaptive immune mechanisms that underlie implant debris reactivity remain incompletely understood. Although particulate debris has been implicated as the major type of implant debris mediating macrophage-induced osteolysis, the degree to which metal ions affect a proinflammatory response (if at all) remains unknown. We hypothesized that both soluble and particulate metal implant debris will induce proinflammatory responses in human monocytes resulting in cytokine production and elevated expression of T cell costimulatory molecules, facilitating adaptive immune responses. We tested this hypothesis by characterizing the response of a human monocyte cell line (THP-1), isolated primary human monocytes and PBMCs challenged with Co-Cr-Mo alloy particles and soluble cobalt, chromium, molybdenum, and nickel ions. Our results indicate that soluble cobalt, nickel, and molybdenum can induce monocyte up-regulation of T cell costimulatory molecules (CD80, CD86, ICAM-1) in human monocytes/macrophages. Furthermore, cobalt, molybdenum ions, and Co-Cr-Mo alloy particles similarly induce elevated secretion of IL-1beta, TNFalpha, and IL-6. Antibody blockade of CD80 and CD86, crucial secondary molecules for adaptive responses, abrogated lymphocyte reactivity to metal challenge in metal reactive subjects. Also the addition of IL-1 receptor antagonist (IL-1ra), (which indirectly blocks pro-IL-1beta and thus IL-1beta release), significantly reduced lymphocyte reactivity in metal-reactive subjects. Thus, both soluble and particulate metal implant debris induce monocyte/macrophage proinflammatory responses that are metal and individual specific. This suggests metal-induced up-regulation of costimulatory molecules and proinflammatory cytokine production is necessary to induce lymphocyte activation/proliferation to metal implant debris.

Magnetic resonance imaging findings of the lumbar spine in elite horseback riders: correlations with back pain, body mass index, trunk/leg-length coefficient, and riding discipline.

BACKGROUND: Most orthopaedic problems experienced by competitive horseback riders are related to pain in the lower back, hip joint, and hamstring muscles. Riders-especially, show jumpers-are frequently hampered in their performance because of lumbar pain. To date, there has been no research into lumbar disk degeneration in elite competitive riders. HYPOTHESIS: Competitive horseback riding accelerates lumbar disk degeneration. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Fifty-eight elite riders (18 men, 40 women; mean age, 32.4 years) and a control group of 30 nonriding volunteers (17 men, 13 women; mean age, 28.7 years) were evaluated for lumbar disk degeneration, cross-sectional area of paraspinal muscles, spondylolysis, and spondylolisthesis, using magnetic resonance imaging (MRI). The prevalence of disk degeneration between the 2 groups was compared, and the relationship was investigated between low back pain (LBP), riding discipline, body mass index (BMI), trunk/leg-length coefficient, and MRI results. RESULTS: Eighty-eight percent of elite riders (n = 51) had a history of LBP, versus 33% of the controls (P < .05). There was no statistical difference for the prevalence of LBP among the different riding disciplines. However, there was a high rate of pathologic T2 signal intensity of the lumbar intervertebral disk among riders-specifically, dressage riders-yet no significant increase when compared with controls. History of LBP symptoms, riding discipline, BMI, and trunk/leg-length ratio had no significant effect on the development of lumbar disk degeneration. Occult fractures of the pars interarticularis and manifest spondylolysis were not seen for any rider. Two controls had spondylolisthesis Meyerding grade 1 not associated with back pain. CONCLUSION: Although riders have a high prevalence of LBP, there is no conclusive MRI evidence to suggest that the cause lies in undue disk degeneration, spondylolysis, spondylolisthesis, or pathologic changes of the paraspinal muscles of the lumbar spine.

Microvasculatory reaction of skeletal muscle to Ti-15Mo in comparison to well-established titanium alloys.

Beta-titanium alloys such as Ti-15Mo are increasingly utilized for orthopaedic implant applications because of their excellent corrosion resistance and low elastic modulus. Particularly in osteosynthesis, where the biomaterial stands in direct contact to soft tissue, undesirable biologic reactions may have severe consequences especially in the vulnerable state of trauma and added iatrogenic damage to the microvascular system. In a comparative study we therefore assessed in vivo nutritive perfusion and leukocytic response of striated muscle to the biomaterials Ti-15Mo, Ti-6Al-4V and Ti-6Al-7Nb, thereby drawing conclusions on their short term inflammatory potential. Utilizing the well established skinfold chamber preparation in the hamster and intravital fluorescence microscopy, we could not demonstrate any significant discrepancies between the three alloys. All metals induced an initial moderate inflammatory response in skeletal muscle microcirculation. While recuperation of animals treated with Ti-15Mo and Ti-6Al-7Nb was prompt, we documented a slightly more sluggish recovery of Ti-6Al-4V treated animals. A gross toxicity was not observed for any of the alloys. Conclusively, Ti-15Mo, Ti-6Al-4V and Ti-6Al-7Nb induce an only transient inflammatory answer of the striated muscle microvascular system. Our results indicate that on the microvascular level the tested bulk Ti-alloys do not cause enduring biologic impairment in muscle.

The evaluation of articular cartilage lesions of the knee with a 3-Tesla magnet.

PURPOSE: This prospective study was performed to investigate whether 3-Tesla magnetic resonance imaging (MRI) provides an accurate assessment of the articular cartilage in clinical practice. METHODS: Forty patients with persistent knee pain and suspected cartilage lesions underwent 3-T MRI shortly before arthroscopy with the following sequences: axial/coronal/sagittal proton density-weighted turbo spin echo with spectral fat suppression, axial/sagittal 3-dimensional T1-weighted gradient echo with selective water excitation, and axial T2-weighted gradient echo (Intera 3.0T; Philips Medical Systems, Best, The Netherlands). Knee cartilage surfaces were divided into 6 regions; lesions detected on MRI were classified into stages I to IV and compared with the arthroscopic grading. RESULTS: For the 240 cartilage surfaces evaluated, the sensitivities, specificities, positive predictive values, and negative predictive values of 3-T MRI were 74%, 95%, 74%, and 95%, respectively, for the detection of grade IV lesions; 63%, 90%, 60%, and 91%, respectively, for grade III lesions; 62%, 90%, 57%, and 92%, respectively, for grade II lesions; and 29%, 95%, 39%, and 92%, respectively, for grade I lesions. CONCLUSIONS: In these preliminary clinical studies 3-T MRI provided convincing visualization of the hyaline cartilage with comparatively good diagnostic values. Nonetheless, it must be pointed out that the positive predictive values were low for all grades of lesions. Thus, when 3-T MRI suggests a cartilage defect, the probability that the arthroscopic finding corresponds exactly to the MRI result is between 39% and 74%. Therefore, the value of arthroscopy for a detailed assessment and grading of a cartilage disorder with regard to definitive planning of a therapeutic procedure cannot be replaced by 3-T MRI. LEVEL OF EVIDENCE: Level I, testing of previously developed diagnostic criteria in a series of consecutive patients with universally applied gold standard.

Short-term microvascular response of striated muscle to cp-Ti, Ti-6Al-4V, and Ti-6Al-7Nb.

Due to excellent mechanical properties and good corrosion resistance, titanium-aluminium-vanadium (Ti-6Al-4V) and titanium-aluminium-niobium (Ti-6Al-7Nb) are extensively used for orthopedic surgery. Concern has been voiced concerning the implications of the constituent vanadium in Ti-6Al-4V on the surrounding environment. Particularly in osteosynthesis where the alloys stand in direct contact to skeletal muscle, undesirable biologic reactions may have severe consequences. In a comparative study, we assessed in vivo nutritive perfusion and leukocytic response of striated muscle to the metals Ti-6Al-4V, Ti-6Al-7Nb, and commercially pure titanium (cpTi), thereby drawing conclusions on their short-term inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we quantified primary and secondary leukocyte-endothelial cell interaction, leukocyte extravasation, microvascular diameter change, and capillary perfusion in collecting and postcapillary venules of skeletal muscle. A manifest discrepancy between the metals concerning impact on local microvascular parameters was not found. All metals induced an only transient and moderate inflammatory response. Only a slight increase in leukocyte recruitment and a more sluggish recuperation of inflammatory parameters in animals treated with Ti-6Al-4V compared to the other two metals suggested a minor, overall not significant discrepancy in biocompatibility. Gross toxicity of bulk Ti-6Al-4V on surrounding tissue could not be found. Conclusively, the commonly used biomaterials Ti-6Al-4V, Ti-6Al-7Nb, and cpTi induce an only transient inflammatory answer of the skeletal muscle microvascular system. Our results indicate that on the microvascular level the tested bulk Ti-alloys and cpTi do not cause adverse biologic reactions in striated muscle.

Microvascular response of striated muscle to common arthroplasty-alloys: A comparative in vivo study with CoCrMo, Ti-6Al-4V, and Ti-6Al-7Nb.

The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. Due to excellent physical and corrosion characteristics, CoCrMo-, Ti-6Al-4V-, and Ti-6Al-7Nb-alloys are commonly used in orthopedic surgery. Yet concern has been raised with regard to the implications of inevitable corrosion product of these metals on the surrounding biologic environment, particularly in the case of CoCrMo. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to these alloys, thereby drawing conclusions on their inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that the implant material CoCrMo has a marked impact on local microvascular parameters. While the Ti-alloys Ti-6Al-4V and Ti-6Al-7Nb induced only a transient and moderate inflammatory response, the implantation of a CoCrMo sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity and marked leukocyte extravasation. Animals with Ti-alloys showed a clear tendency of recuperation, while in all but one CoCrMo-treated animals, a breakdown of microcirculation prior to the scheduled end of the experiment was observed. Overall, the alloy Ti-6Al-7Nb was tolerated slightly better than Ti-6Al-4V under the chosen test conditions, though this discrepancy was not statistically significant. Conclusively, the commonly used biomaterials Ti-6Al-7Nb and Ti-6Al-4V induce a considerably lower inflammatory response in the skeletal muscle microvascular system, compared to a CoCrMo-alloy. With a minimum of adverse host reaction, our results indicate that for this particular model Ti-alloys are better tolerated than CoCrMo implant materials.

Coccygectomy for coccygodynia: does pathogenesis matter?

BACKGROUND: Severity of vertical impact to the coccyx can range from mere contusion to a dislocated fracture of the coccyx. With early conservative management, most patients have a good prognosis and heal within weeks to months after the initial trauma. Occasionally, persisting symptoms make a surgical intervention with coccygectomy necessary. METHODS: We report on the results of patients surgically managed for traumatically induced, persisting coccygodynia and compare these to patients operatively treated for idiopathic coccygodynia. Sixteen patients with an average follow-up of 7.3 years were evaluated. Of these, eight were surgically treated for traumatic and eight for idiopathic coccygodynia. The clinical results were assessed by means of the Hambly Score and the Oswestry Low Back Pain Disability questionnaire. Patient satisfaction with the postoperative result was assessed by a visual analog scale. RESULTS: Seven of eight (88%) patients treated for traumatically induced coccygodynia had a good or excellent postoperative result, in contrast to only three of eight (38%) patients with idiopathic coccygodynia. The former group had better results in terms of sitting tolerance and general pain intensity as represented by the Oswestry Low Back Pain Disability questionnaire. According to the significantly better clinical results, personal satisfaction was clearly higher in the traumatic group. CONCLUSION: These results suggest that, in patients where all conservative treatment methods work to no avail, particularly those with traumatically induced persisting coccygodynia benefit from surgical intervention with coccygectomy.