Uwe Maus

In-vivo analysis of epicutaneous pressure distribution beneath a femoral tourniquet – an observational study

BackgroundCompression of the tissue beneath tourniquets used in limb surgery is associated with varying degrees of soft tissue damage. The interaction between fluids and applied pressure seems to play an important role in the appearance of skin lesions. The extent of the transfer of force between the tourniquet and the skin, however, has yet to be studied. The aim of the present study was to quantify in-vivo the transfer of pressure between a tourniquet and the skin of the thigh.MethodsPressure under the tourniquet was measured using sensors in 25 consecutive patients over the course of elective surgical procedures. Linear mixed modeling was used to assess the homogeneity of the distribution of pressure around the circumference of the limb, variation in pressure values over time, and the influence of limb circumference and the Body-Mass-Index (BMI) on pressure transfer.ResultsMean pressure on the skin was significantly lower than the inner pressure of the cuff (5.95%, 20.5u2009±u20099.36xa0mmHg, pu2009<u20090.01). There was a discrete, but significant (pu2009<u20090.001) increase in pressure within the first twenty minutes after inflation. Sensors located in the area of overlap of the cuff registered significantly higher pressure values (pu2009<u20090.01). BMI and leg circumference had no influence on the transfer of pressure to the surface of the skin (pu2009=u20090.88 and pu2009=u20090.51).ConclusionsPressure transfer around the circumference of the limb was distributed inhomogeneously. The measurement series revealed a global pressure drop compared to the initial pressure of the cuff. No relationship could be demonstrated between the pressure transferred to the skin and the BMI or limb circumference.

Is there an association between periprosthetic joint infection and low vitamin D levels

PurposeVitamin D is increasingly being recognized as an important mediator of immune function and may have a preventive role in the pathogenesis of periprosthetic joint infection. To the best of our knowledge, no other study has examined possible associations between periprosthetic joint infection and vitamin D deficiency. We investigated the rate of vitamin D deficiency in patients treated for periprosthetic joint infection and whether vitamin D deficiency is independent of other risk factors for vitamin D deficiency in patients with periprosthetic joint infection.MethodsSerum 25-hydroxyvitamin D (25OHD) levels of every patient scheduled to receive a total prosthesis either of the hip, knee, or shoulder in the orthopaedic department of the Johannes-Guttenberg-University Hospital in Mainz, Germany (109 patients), were measured after admission. Furthermore, serum 25OHD levels were measured for every patient presenting with periprosthetic joint infection (nu2009=u200950) or aseptic loosening of the prosthesis (nu2009=u200931) scheduled to undergo revision surgery. The prevalence of normal (>30xa0ng/ml), insufficient (20–30xa0ng/ml), and deficient (<20xa0ng/ml) 25OHD levels was determined.ResultsAll tested patient subgroups showed low vitamin D levels. Statistical analysis found no significant difference in vitamin D levels comparing patients with prosthesis and patients with aseptic prosthesis loosening (pu2009=u20090.58). Significant differences in 25OHD levels were found comparing patients with periprosthetic joint infection and patients scheduled for primary arthroplasty (pu2009<u20090.001). In addition, we found a significant difference (pu2009<u20090,001) in 25OHD levels of patients with periprosthetic joint infection compared with patients with aseptic prosthesis loosening.ConclusionWe found a high frequency of vitamin D deficiency in patients being treated by primary arthroplasty and those with aseptic joint prosthetic loosening and periprosthetic joint infection. Vitamin D deficiency was severe in patients with periprosthetic joint infection.

Is There an Epidemic Vitamin D Deficiency in German Orthopaedic Patients

BackgroundVitamin D plays an essential role in bone health and muscle function. Some studies have shown a widespread rate of vitamin D deficiency in the general population, but few have reported on the vitamin D status of orthopaedic patients.Questions/purposesWe investigated (1) the extent of hypovitaminosis D in orthopaedic patients, (2) seasonal variations in vitamin D levels, and (3) possible risk factors for insufficient vitamin D levels.MethodsVitamin D levels in 1119 patients consecutively admitted to an orthopaedic surgery department in 2011 were measured. To investigate the correlation between climate factors and vitamin D levels, the sunshine hours for each month in 2011 were collected by Deutscher Wetterdienst (the German weather service) in the region where most tested patients lived. The prevalence of normal (> 30 ng/mL), insufficient (20–30 ng/mL), and deficient (< 20 ng/mL) 25-hydroxyvitamin D levels was determined. Univariate and multivariate analyses were used to assess risk factors for insufficient vitamin D levels.ResultsOverall, 84% of patients had insufficient levels of vitamin D and 60% were vitamin D deficient. Only 15% were in the target range of 30 to 60 ng/mL. The prevalence of low vitamin D levels was greater during winter and months with fewer sunshine hours. Vitamin D levels did not vary according to age, sex, and disease. Individuals with obesity, hypertension, and osteoporosis were more likely to have low vitamin D levels compared with their healthy counterparts.ConclusionsThere is an alarmingly high rate of hypovitaminosis D and vitamin D deficiency among orthopaedic patients in this region of Germany, whose latitude (50° N) is approximately the same as those of Vancouver (49°, 15’ N) and Paris (48°, 51’ N). Given the well-known effects on bone metabolism and muscle health, low vitamin D levels may negatively affect patients. Screening and treating hypovitaminosis D appears to be important in this patient population.Level of EvidenceLevel II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Intraosseous Fixation Compared to Plantar Plate Fixation for First Metatarsocuneiform Arthrodesis A Cadaveric Biomechanical Analysis

Background: Metatarsocuneiform (MTC) fusion is a treatment option for management of hallux valgus. We compared the biomechanical characteristics of an internal fixation device with plantar plate fixation. Methods: Seven matched pairs of feet from human cadavers were used to compare the intramedullary (IM) device plus compression screw to plantar plate combined with a compression screw. Specimen constructs were loaded in a cyclic 4-point bending test. We obtained initial/final stiffness, maximum load, and number of cycles to failure. Bone mineral density was measured with peripheral quantitative computed tomography. Performance was compared using time to event analysis with number of cycles as time variable, and a proportional hazard model including shared frailty model fitted with treatment and bone mineral density as covariates. Results: On average the plates failed after 7517 cycles and a maximum load of 167 N, while the IM-implants failed on average after 2946 cycles and a maximum load of 69 N. In all pairs the 1 treated with IM-implant failed earlier than the 1 treated with a plate (hazard ratio for IM-implant versus plate was 79.9 (95% confidence interval [6.1, 1052.2], P = .0009). The initial stiffness was 131 N/mm for the plantar plate and 43.3 N/mm for the IM implant. Initial stiffness (r = .955) and final stiffness (r = .952) were strongly related to the number of cycles to failure. Bone mineral density had no effect on the number of cycles to failure. Conclusion: Plantar plate fixation created a stronger and stiffer construct than IM fixation. Clinical Relevance: A stiffer construct can reduce the risk of nonunion and shorten the period of non-weight-bearing.

Vitamin D insufficiency in the elderly orthopaedic patient: an epidemic phenomenon

PurposeThe purpose of this observational study was to evaluate serum levels of 25-OH-D of elderly patients presenting with orthopaedic illness. Furthermore, we enquired about potential confounders and risk factors of hypovitaminosis D in comorbidities and daily medication of the elderly.MethodsVitamin D levels in 1,083 patients aged >70xa0years and admitted to an orthopaedic surgery department were measured. Univariate and multivariate analyses were used to assess risk factors for insufficient vitamin D levels.ResultsOverall, 86xa0% of patients had insufficient serum levels of 25-OH-D and >60xa0% were vitamin D deficient. Serum vitamin D levels were lower during winter and months with fewer sunshine hours. Patients presenting with obesity, hypertension and osteoporosis were more likely to have low vitamin D levels.ConclusionsWe found a high prevalence of hypovitaminosis D in elderly, nonhospitalized orthopaedic patients. Given the well-known effects of vitamin D on bone metabolism and muscle health, as well as its nonskeletal effects, vitamin D insufficiency may have a negative impact.

Risk factors for pelvic insufficiency fractures and outcome after conservative therapy

PURPOSEnThe prevalence of osteoporosis has continuously increased over the past decades and it is set to increase substantially as life expectancy rises steadily. Fragility or osteoporotic fractures of the pelvis often occur after low energy falls e.g. from standing, however, some patients present with assumed insufficiency fractures of the pelvis without a previous trauma. Osteoporotic fractures impose a tremendous economic burden and these fractures deserve attention as they lead to a decrease in mobility with an increase in dependency and are associated with a high rate of mortality. To date, little is known about potential risk factors for pelvic insufficiency fractures. Furthermore, information on clinical outcome is scarce. In view of this rather limited knowledge, we aimed to identify potential risk factors for pelvic insufficiency fractures and to collect information on their short- and long-term outcomes.nnnMETHODSnFiles of all consecutive patients admitted between January 2010 and December 2013 for a pelvic insufficiency fracture were enrolled in this study. Pelvic fractures that occurred on tumorous bone or after high-energy trauma were excluded. Fractures of the pelvis included all pelvic bones except the coccyx. For all patients, we recorded clinical and biological parameters available from their medical history. For comparison, the same biological and clinical parameters were evaluated in an age matched control group of 1083 patients aged over 70 who were admitted to our orthopaedic department to undergo knee or hip arthroplasty. The statistical analyses used or Fisher test for percentages comparison, 2-tailed t-tests and Mann Whitney for mean comparison. To determine what factors are predictors and what factors are confounders of pelvic insufficiency fractures, multivariate linear regression analysis using the fracture as a continuous variable was performed.nnnRESULTSnNinety-three patients with a pelvic insufficiency fracture were identified. Following the Rommens and Hofmann classification for fragility fractures of the pelvis (FFP), 51 were FFP Type Ia, 26 were FFP Type IIb lesions and 26 were FFP Type IIc. Osteoporosis was found to be significantly associated with pelvic insufficiency fractures (p=0.003), as was hypertension (p=0.036), diabetes (p=0.021), vitamin D deficiency (p=0.004), hypocalcaemia (p=0.002) and nicotine abuse (p=0.0012) after adjustment for possible confounders in the multivariate linear regression analysis. Comparing the autonomous state before and after pelvic fracture, a high loss of autonomy was observed. Patients needing daily assistance nearly doubled their number. Overall mortality was high (20%).nnnCONCLUSIONSnIn conclusion, this study showed multiple risk factors for pelvic insufficiency fractures. Some, like vitamin D deficiency, can benefit easy preventive measures. Outcome of conservative therapy is poor, with loss of social and physical independence and autonomy. The mortality rate is high. Efforts should be made in preventing pelvic insufficiency fractures. All patients should be treated for the severe osteoporosis being associated with these fracture type.

Is there an association between low serum 25-OH-D levels and the length of hospital stay in orthopaedic patients after arthroplasty?

BackgroundThe purpose of this observational study was to evaluate serum levels of 25-OH-D in patients scheduled to undergo elective hip or knee arthroplasty. We hypothesised that 25-OH-D level is an independent risk factor for length of stay in orthopaedic patients after elective hip or knee arthoplasty.Materials and methods25-OH-D levels were measured in 1083 patients admitted to an orthopaedic surgery department to undergo elective hip or knee arthroplasty. Comparisons were performed using Chi square or Student’s t test, followed by univariate and multiple linear regression analysis examining the correlation between the length of stay in the orthopaedic department and 25-OH-D level while adjusting for possible confounders.ResultsOverall, 86xa0% of patients had insufficient serum levels of 25-OH-D, and over 60xa0% were vitamin D deficient. The mean length of stay was 13.2xa0±xa08.3xa0days. In patients with hypovitaminosis D, the length of stay was significantly longer compared to patients with normal serum 25-OH-D levels (15.6xa0±xa07.2 compared to 11.3xa0±xa07.9xa0days, Pxa0=xa00.014). In univariate analyses, serum 25-OH-D level was inversely related to the length of stay in our orthopaedic department compared to patients with normal vitamin D levels (rxa0=xa0−0.16; Pxa0=xa00.008). In multivariate analyses, the length of stay remained significantly associated with low 25-OH-D levels (Pxa0=xa00.002), indicating that low vitamin D levels increase the length of stay.ConclusionsWe found a high frequency of hypovitaminosis D among orthopaedic patients scheduled to undergo elective arthroplastic surgery. Low vitamin D levels showed a significant inverse association to the length of stay in our orthopaedic department. Patients with vitamin D levels in the target range were hospitalised 4.3xa0days less than patients with hypovitaminosis D.Level 3 of evidence according to “The Oxford 2011 levels of evidence”.

Procalcitonin (PCT) als Verlaufsparameter der Spondylodiszitis

AIMnThe diagnosis of spondylodiscitis is often prolonged, but it is an important differential diagnosis of backache. The discrimination between a bacterial infection and an aseptic inflammation with laboratory examinations like ESG, CRP or leukocytes is not possible. The aim of the present study was to determine the value of procalcitonin (PCT) as a diagnostic tool and monitoring parameter for spondylodiscitis and for the discrimination between bacterial infection and aseptic inflammation of the spine.nnnMETHODnA total of 17 patients with spondylodiscitis and 18 patients with disc herniation as control were included in this study and ESG, CRP, leukocytes, fibrinogen, PNM elastase und PCT were examined for 50 days. The median age was 65 (17-78) years and the ratio of males to females was 8 : 9 in patients with spondylodiscitis and 62 (32-87) years and 7 : 11 in patients with disc herniation. For microbiological examination, CT-guided punctures were performed in patients with spondylodiscitis.nnnRESULTSnIn 64 % of the 17 patients with spondylodiscitis a microbiological agent was detected, in 73 % of these cases staphylococcus aureus was isolated. The laboratory parameters indicating an infection were increased except for two cases in patients with spondylodiscitis, the mean value of CRP was 115 mg/dL. Influenced by the therapy these parameters decreased during the observation period. Except for one patient with an infection of a cardiac pacemaker, the PCT concentration was not elevated in both groups (< 0.5 ng/mL). In the group with disc herniation there were no elevated laboratory parameters during the entire observation period.nnnCONCLUSIONnPCT is not useful as diagnostic tool or monitoring parameter for spondylodiscitis. Furthermore, it is not useful for the discrimination between a bacterial infection and an aseptic inflammation of the spine.

In vitro elution characteristics of gentamicin and vancomycin from synthetic bone graft substitutes.

Objects: Beta tricalciumphosphate pellets loaded with individualized antibiotics may represent novel options in the treatment of osteomyelitis and infectious bone disease. Here, the in vitro antibiotic elution of vancomycin and gentamicin from the synthetic bone graft substitutes Cerasorb® and Cerasorb M® was tested. Methods: Antibiotic elution and concentration of gentamcin and vancomycin were measured using photometrically-based measurement and homogeneous particle-enhanced turbidimetric inhibition immunoassays (PETINIA). Results: Initially both materials showed a high release of the loaded antibiotics, with Cerasorb M® showing lower release levels for gentamicin and vancomycin than Cerasorb®. Gentamicin concentrations of Cerasorb M granules and Cerasorb were below the minimum detectiontreshold until day four and six of the experiment respectively. The vancomycin release-level followed a similar pattern, although the vancomycin concentration eluted by Cerasorb M® granules stayed above the detection threshold during the experimental time. Conclusions: Cerasorb® and Cersorb M® may represent a new treatment option in osteomyelitis and infectious bone disease.

Open versus endoscopic bone resection of the dorsolateral calcaneal edge: a cadaveric analysis comparing three dimensional CT scans

BackgroundIt has been claimed that endoscopic calcaneoplasty offers some advantages over open techniques in the surgical treatment of Haglund’s deformity due to reduced postoperative complications like stiffness and pain. Bony over-resection places patients at risk of these complications. The resulting question with regard to the quantitative differences of the extent of the bone removed using these two techniques has not yet been answered. The purpose of the study was to determine the resection volume of calcaneal bone for open and endoscopic surgical techniques.Methods16 feet obtained from body donors were operated on in equal parts using either open surgical or endoscopic techniques, with the technique selected on a random basis. High-resolution CT scans were obtained before and after the interventional procedure and analysed to obtain 3-D polygon models. Post-operative models were subtracted from pre-operative models to provide the volume change resulting from the intervention. This was then correlated with the bone mineral density (BMD) of the preparation.ResultsThe extent of bony resection was greater in open surgical techniques than in endoscopic approaches. The average volume of bone resection was 0.80 (±0.34) cm3 in the endoscopic group and 3.04 (±2.91) cm3 in the group that underwent open surgery. After adjustment for bone mineral density the extent of the resection was significantly larger (pu2009=u20090.018) in the group undergoing open surgery. The two groups did not differ significantly with regard to BMD (pu2009>u20090.1). The extent of the resection fell by 0.011xa0cm3 per 1xa0mg/cm3 areal bone mineral density, i.e., a slightly lower degree of bone resection was associated with a higher bone mineral density.ConclusionsAssuming that the resection volume was adequate to treat the patient’s complaints a smaller resection volume seen in our study using an endoscopic technique might lead to fewer postoperative complaints and faster recovery.