Frank Krummenauer

Cumulative incidence rates of the mucopolysaccharidoses in Germany.

SummaryIn order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100 000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100 000 births (1.3 cases per 100 000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100 000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100 000; and that for MPS VI (Maroteaux–Lamy syndrome) as 0.23 cases per 100 000 births. Two cases of MPS IVB (β-galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100 000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4–4.5 in 100 000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.

Exposure to chromium, cobalt and molybdenum from metal-on-metal total hip replacement and hip resurfacing arthroplasty.

Background All metal implants—and metal-on-metal bearings in particular—corrode and cause a release of metal ions. Because cobalt and chromium have been shown to be carcinogenic and mutagenic in human and animal models, systemic toxicity and cancer risk are considered to be possible disadvantages of the metal-on-metal articulation. This study was designed to investigate the serum concentration profiles of chromium, cobalt and molybdenum after implantation of a Birmingham hip resurfacing arthroplasty (BHR) and a cementless total hip replacement with a 28-mm Metasul articulation (MTHR), over the first 2 years after implantation. Methods We analyzed profiles of metal ion serum levels in 111 patients implanted with a BHR, in 74 patients implanted with an MTHR, and in 130 implant-free probands control subjects using atomic absorption spectrophotometry. Results Chromium and cobalt concentrations (in μg/L) of all BHR and MTHR patients differed significantly from those of control subjects (chromium: < 0.25; cobalt: 0.25). The median chromium and cobalt concentrations in BHR patients had increased to 5.1 and 4.3 μg/ L 2 years after surgery. Concentrations in BHR patient exceeded those in the unilateral MTHR patients. Molybdenum serum concentrations hardly changed over time in either group and were not significantly different from the concentrations seen in the control subjects. Interpretation During the first 2 years after surgery, the Birmingham hip resurfacing arthroplasty leads to a significantly greater increase in serum chromium and cobalt levels than the 28-mm metal-on-metal MTHR. Observation of patients over a longer period will be necessary in order to evaluate any chronic adverse effects to the system due to elevated chromium and cobalt serum concentrations.

Serum metal ion exposure after total knee arthroplasty.

All metal implants release metal ions because of corrosion. This has been studied and debated, especially in metal-on-metal total hip arthroplasties. Total knee arthroplasty implants have large metal surface areas and therefore substantial potential for corrosion. We determined changes in serum levels of metal ions in 41 patients after cemented unconstrained total knee arthroplasty without patellar resurfacing, 18 with unilateral total knee arthroplasty (median, 66 months after surgery) and 23 patients with bilateral total knee arthroplasties (75 and 50 months after first and second surgeries, respectively). Serum concentrations of chromium, cobalt, and molybdenum were analyzed and related to the number of total knee arthroplasties and compared with those of 130 control patients without implants. The median chromium, cobalt, and molybdenum concentrations were 0.92, 3.28, and 2.55 μg/L, respectively, in the unilateral total knee arthroplasty sample and 0.98, 4.28, and 2.40 μg/L, respectively, in the bilateral total knee arthroplasty sample. We observed no difference between the serum levels in patients with unilateral and bilateral arthroplasties, but the serum levels of chromium and cobalt of both study groups were greater than those of the control group (less than 0.25 μg/L). The patients who had total knee arthroplasty had molybdenum profiles that were similar to those of the control group (median, 2.11 μg/L).

Neo-capsule tissue reactions in metal-on-metal hip arthroplasty

Background Modern-generation metal-on-metal articulations have a high wear resistance and may therefore be able to improve the long-term performance of artificial joints. However, the biological effects are still under debate. This study was undertaken to review the histopathological changes in neo-capsule tissues of different metal-on-metal hip arthroplasties. Methods Neo-capsule tissue samples from 46 hips with modern second-generation metal-on-metal articulations (39 hip resurfacings and 7 non-cemented total hip replacements) with a variety of failure mechanisms were examined histopathologically and immunohistochemically. Results A distinct lymphocytic infiltration was found in all cases with in situ times of more than 7 months, consisting of CD20-positive B-lymphocytes and CD3positive T-lymphocytes and sometimes thinly distributed CD138-positive plasma cells without dominant T-cell or plasma cell infiltrates. Interpretation This distinct lymphocytic infiltration has not been reported in tissue analyses of metal- or ceramic-on-polyethylene hip replacements, and may therefore be considered to be a characteristic histological pattern of tissue reactions on metal particles and/or ions around metal-on-metal bearings.

Critical assessment of chitotriosidase analysis in the rational laboratory diagnosis of children with Gaucher disease and Niemann-Pick disease type A/B and C

SummaryLaboratory diagnosis of lysosomal storage disorders, especially sphingomyelinase deficiency (Niemann–Pick disease type A/B) and Niemann–Pick disease type C (NPC) can be challenging. We therefore aimed to analyse the feasibility of first-step screening with specific chitotriosidase cut-off values in children ≤ 10 years of age with visceral organomegaly (hepatomegaly, splenomegaly, or hepatosplenomegaly) in whom a storage disorder was suspected. We conducted a retrospective, cross-sectional, referral, single-centre study to assess diagnostic test properties in 106 individuals. Median chitotriosidase activity was 12 655 nmol/h per ml (interquartile range 4693–20982) in Gaucher disease (GD); 780 (465–1298) in SMD (sphingomyelinase deficiency); 925 (319–1215) in NPC and 50 (29–54) in patients with miscellaneous diseases. To restrict the differential diagnosis to GD, SMD or NPC, chitotriosidase activity above 200 nmol/h per ml had a sensitivity of 96%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 95%. For GD alone, chitotriosidase activity above 4000 nmol/h per ml had a sensitivity of 77%, specificity of 100%, PPV of 100% and NPV of 92%. Of the 44 patients analysed, 4.5% were homozygous and 36.4% heterozygous for chitotriosidase gene duplication. Adjusting for the chitotriosidase genotype, chitotriosidase activities were higher in GD type III than in GD type I. We conclude that, in the above setting, the degree of elevation of chitotriosidase activity can be applied to increase the likelihood of GD, SMD, or NPC and guide the choice of the appropriate confirmatory assay.

Rotational alignment of the tibial component in total knee arthroplasty is better at the medial third of tibial tuberosity than at the medial border

BackgroundCorrect rotational alignment of the femoral and tibial component is an important factor for successful TKA. The transepicondylar axis is widely accepted as a reference for the femoral component. There is not a standard reference for the tibial component. CT scans were used in this study to measure which of 2 tibial landmarks most reliably reproduces a correct femoro-tibial rotational alignment in TKA.Methods80 patients received a cemented, unconstrained, cruciate-retaining TKA with a rotating platform. CT scans were performed 5-7 days postoperatively but before discharge. The rotational mismatch between the femoral and tibial components was measured. Furthermore, the rotational variance between the transepicondylar line, as a reference for the orientation of the femoral component and different tibial landmarks, was measured.ResultsThere was notable rotational mismatch between the femoral and tibial components. The median mismatch was 0° (range: 16.2 degrees relative external to 14.4 degrees relative internal rotation of the femoral component).Using the transepicondylar line as a reference for femoral rotational alignment and the medial third of the tuberosity as a reference for tibial rotational alignment, 67.5% of all TKA had a femoro-tibial variance within ± 5 degrees, 85% within ± 10 degrees and 97.5% within ± 20 degrees. Using the medial border of the tibial tubercle as a reference this variance was greater, only 3.8% had a femoro-tibial variance within ± 5 degrees, 15% within ± 10 degrees and 68.8% within ± 20 degrees.ConclusionUsing fixed bone landmarks for rotational alignment leads to a notable variance between femoral and tibial components. Referencing the tibial rotation on a line from the medial third of the tibial tubercle to the center of the tibial tray resulted in a better femoro-tibial rotational alignment than using the medial border of tibial tubercle as a landmark. Surgeons using fixed bearings with a high rotational constraint between the inlay and the femoral component should be aware of this effect to avoid premature polyethylene wear.Trial RegistrationClinical trials registry NCT01022099

Social, educational, and occupational predictors of total hip replacement outcome.

OBJECTIVE There is limited evidence on social, educational, and occupational factors as predictors of response to total hip replacement (THR). We aimed to analyze these factors in a large population-based setting. METHOD Patients of the Dresden Hip Surgery Registry were recruited and the pre and post (6 months) operative functional status was assessed using the global Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score (0-100 points). Non-response was defined a gain of <20 points in WOMAC score over a 6 months period and was analyzed with respect to six socioeconomic parameters. Multiple logistic regression modeling was applied to adjust for age, sex, BMI, co-morbidity, and preoperative functional status. RESULTS Data from 1007 patients (mean age 61 years, STD 13; 55% women) were included. The average preoperative WOMAC score was 45.8 which increased to 84.4 after surgery. 38.2%, 36.6%, and 25.3% of the patients attended school for 8, 9, and 12 years, respectively. 54.1% were retired, 26.9% worked full time, and 6.7% received a disability pension. A 14.8% of the patients did not achieve a gain of > or =20 points in WOMAC score and were classified as non-responders. After control for confounders, significantly increased risks of non-response were found for widowed patients compared to singles [odds ratio (OR) 4.30, 1.45-12.71], those who lived alone (OR 1.70, 1.02-2.85), and patients with a disability pension compared to those who worked full time (OR 5.81, 2.33-14.46). The risk of non-response decreased with increasing length of school education (12 vs 8 years: OR 0.49, 0.27-0.89). Compared to workers, employees (OR 0.55, 0.33-0.90) and self-employed patients (OR 0.41, 0.18-0.94) showed significantly decreased risks of non-response. CONCLUSION Socioeconomic parameters are independent predictors of response to THR. This can help to improve the health service by identifying subgroups which need special attention in order to increase the response rate.

Short-term outcome after posterior versus lateral surgical approach for total hip arthroplasty - a randomized clinical trial*

PurposeCurrently, total hip replacement (THR) is most commonly performed via a posterior or a direct lateral approach, but the impact of the latter on the inventions outcome has yet not been quantified.MethodsWe compared the short-term outcome of cementless THR using the both approaches in a prospective, randomized controlled trial. 60 patients with unilateral osteoarthritis were included. Outcome assessment was performed one day before surgery and one week, four weeks, six weeks and 12 weeks after surgery, respectively, using the Harris Hip score as primary objective.ResultsWe found no significant difference in the intraindividual Harris Hip Score improvement at the pre-and three months post-operative assessments between both treatment groups (p = 0.115). However, Harris Hip scores and most functional and psychometric secondary endpoints showed a consistent tendency of a slightly better three months result in patients implanted via the posterior approach. In contrast a significant shorter operating time of the direct lateral approach was recorded (67 minutes versus 76 minutes, p < 0.001).ConclusionIn our opinion this slightly better short-term functional outcome after posterior approach is not clinical relevant. However, to make definitive conclusions all clinical relevant factors (i.e. mid- to long-term function, satisfaction, complication rates and long-term survival) have to be taken into account. Level of evidence: I - therapeutic

New technology for sizing the continuous curvilinear capsulorhexis: prospective trial.

PURPOSE: To evaluate the deviation of the continuous curvilinear capsulorhexis (CCC) from the target size and shape when a data‐injection ring is used. SETTING: University Eye Clinic, Bochum, Germany. METHODS: In a randomized clinical trial, the horizontal and vertical intraoperative and postoperative CCC diameters in 96 eyes having cataract surgery were measured and compared with a 5.1 mm target size. The eyes were randomly assigned to 1 of 2 groups: (1) data‐injection ring system, in which a reference ring was projected through the light source of the operating microscope to the anterior capsule surface to guide the CCC procedure, and (2) no data‐injection system. The primary clinical endpoint was the identification of a statistically significant difference in CCC diameter and in the scatter around the target diameter between Group 1 and Group 2. RESULTS: No statistically significant between‐group differences were found in mean CCC diameter or horizontal and vertical diameter deviation from the target size. Significant differences were found in the scatter around the target CCC diameter. Intraoperatively, the horizontal CCC diameter was within the normal reference range (4.9 to 5.3 mm) in 92% of eyes in Group 1 and 27% of eyes in Group 2 (P<.001). The vertical diameter was within the normal range in 83% and 21%, respectively. Postoperatively, the same tendency persisted (P≤.002). CONCLUSION: Use of the data‐injection ring system by an experienced surgeon led to more accurate CCC diameters in relation to the scatter around a reference zone.

Biaxial microincision versus coaxial small-incision cataract surgery in complicated cases

PURPOSE: To evaluate and compare the results of biaxial microincision and coaxial small‐incision surgery in patients with cataract with coexisting exfoliation syndrome, uveitis, anterior or posterior synechias, phacodonesis, or previous intraocular surgery over an 8‐week follow‐up. SETTING: Department of Ophthalmology, Mainz University, Mainz, Germany. METHODS: Eyes were prospectively assigned (1:1) to have biaxial microincision (<1.5 mm) phacoemulsification or coaxial small‐incision (2.8 mm) phacoemulsification using pulsed ultrasound energy (Sovereign WhiteStar) with variable duty cycles followed by implantation of a microincision intraocular lens. Intraoperative and postoperative complications, corrected distance visual acuity (CDVA), laser flare photometry values, effective phacoemulsification time (EPT), and endothelial cell count (ECC) were evaluated. RESULTS: The study enrolled 94 eyes. There were no statistically significant differences between the techniques in intraoperative or postoperative complications. The most frequent postoperative complications were corneal edema surrounding the incision (40%, biaxial group; 35%, coaxial group), pupil distortion (3% versus 7%), and fibrin exudation (3% versus 3%). No other postoperative complications occurred. The median EPT was statistically significantly shorter (1.34 seconds versus 5.4 seconds) and the median phaco power significantly lower (3.3% versus 12.9%) in the biaxial group than in the coaxial group (P<.001). There were no differences between groups in CDVA, laser flare photometry values, or ECC. CONCLUSIONS: The EPT was shorter and the mean phaco power lower with biaxial phacoemulsification, perhaps because of better access of the phaco handpiece for grooving the nucleus with this technique. The 2 techniques were comparable in intraoperative and postoperative complications. Financial Disclosure: No other author has a financial or proprietary interest in any material or method mentioned.