The comparative analyses of decalcification procedures and methyl benzoate pre-treatment on tissue preservation and antigenicity in human acetabular labra.

The histological processing of musculoskeletal tissue might be challenging. The alteration of tissue composition e.g. by calcification of soft tissue in the elderly, after trauma or surgical interventions makes the histological processing of fixed tissue difficult. Additional steps of decalcification are then needed that probably affect the staining quality. In the present work, the effects of different decalcification agents and the intermedium methyl benzoate on histological staining methods and immunohistochemistry have been compared. Acetabular labra were fixed with 4% paraformaldehyde, left untreated or decalcified using 30% ethylenediaminetetraacetic acid (EDTA; Chelaplex®) or 6% trichloroacetic acid (TCA) for 1-4 days to investigate the effects of decalcification duration. Moreover, samples were pretreated with methyl benzoate or conventionally paraffin embedded independent of decalcification procedure and duration. The specimens were evaluated using hemalaun-eosin, Azur II- methylene blue staining or immunohistochemistry against ankyrin B to visualize nerve fibers. Decalcification with Chelaplex® or TCA reduced cutting artifacts without affecting the tissue morphology and proteoglycan staining but decreased antigenicity in immunohistochemistry. Interestingly, methyl benzoate further reduced cutting artifacts without altering tissue morphology and elevated antigenicity for Chelaplex® decalcified tissue samples in immunohistochemistry. The decalcification with Chelaplex® or 6% TCA preserves tissue morphology and proteoglycan staining similar to non- decalcified tissue but facilitates section processing. In immunohistochemistry both decalcification agents decreased antigenicity. Chelaplex® decalcified, methyl benzoate treated samples yielded an improved antigenicity.

Evaluation of a multimodal pain therapy concept for chronic pain after total knee arthroplasty: a pilot study in 21 patients.

BACKGROUND: In spite of the improvement of many aspects around Total knee arthroplasty (TKA), there is still a group of 10% to 34% of patients who is not satisfied with the outcome. The therapy of chronic pain after TKA remains a medical challenge that requires an interdisciplinary therapy concept. The aim of this prospective pilot study was to evaluate the efficacy of a multimodal pain therapy in chronic complaints after TKA. METHODS: In a prospective cohort pilot study, we included patients with chronic pain after TKA who obtained in-patient care, especially multimodal pain therapy (MMPT), for at least 10 days. Essential elements of this therapy concept were physiotherapy, pain medication therapy, topical application of ketamine, local infiltration and Traditional Chinese Medicine. Patients with varying causes of complaints were excluded in advance. Before the start of the study all test persons were informed and gave their written consent. Moreover, each patient was examined and questioned at hospital admission, discharge and at its first as well as second follow-up. Additionally, knee joint mobility and stability were investigated at all examination times. RESULTS: From 03/07/2016 to 07/14/2016, 21 patients were included in the pilot study. 52% of the considered population were female (11 persons). The median age was 65 years (45-79 years) and the median stay in hospital amounted 9 days (8-14 days). The first follow-up was scheduled after six weeks (median: 38 days, 30-112 days) and the second one after six months (median: 8 months, 7-12 months). The number of patients of the first follow-up was 17 out of 21 (19% drop out). The drop out of the last follow-up accounted for 33%. All patients benefit from the presented applications and therapies with regard to pain, function and range of motion. Especially, during the period of in-patient treatment, nearly all patients have improved in all terms. However, during the first follow-up clear deteriorations occurred in all areas, which stagnated up to the second follow-up. The range of motion has even worsened slightly. CONCLUSIONS: With the presented pilot study on multimodal in-patient therapy of chronic complaints due to TKA, the improvement of pain, function and mobility could be verified, especially during the stationary stay. Even though the results deteriorate during the follow-up period, they did never relapse to their initial level. In order to ensure an effective treatment, a clear diagnostic algorithm is essential, by which treatable causes, such as low-grade infections or loosenings, are safely excluded. Further prospective studies are necessary to obtain precise statements on prospects of success of our therapy plan.

Perioperative risk factors in patients with a femoral neck fracture - influence of 25-hydroxyvitamin D and C-reactive protein on postoperative medical complications and 1-year mortality.

BACKGROUND: This study examined the association of 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP) with postoperative medical complications and one year mortality of elderly patients sustaining a low-energy cervical hip fracture scheduled for surgery. We hypothesized that vitamin D deficiency and CRP in these patients might be associated with an increased 1-year mortality. METHODS: The prospective single-center cohort study included 209 patients with a low-energy medial femoral neck fracture; 164 women aged over 50 years and 45 men aged over 60 years. Referring to 1-year mortality and postoperative medical complications multiple logistic regression analysis including 10 co-variables (age, sex, BMI, ASA, creatinine, CRP, leukocytes hemoglobin, 25(OH)D, vitamin D supplementation at follow-up) was performed. RESULTS: Vitamin D deficiency was prevalent in 87 % of all patients. In patients with severe (<10 ng/ml) and moderate (10-20 ng/ml) vitamin D deficiency one year mortality was 29 % and 13 %, respectively, compared to 9 % in patients with > 20 ng/ml 25(OH)D levels (p =0.027). Patients with a mild (CRP 10-39.9 mg/l) or active inflammatory response (CRP ≥ 40 mg/l) showed a higher one year mortality of 33 % and 40 % compared to 16 % in patients with no (CRP < 10 mg/l) inflammatory response (p = 0.002). Multiple logistic regression analysis identified CRP (OR 1.01, 95 % CI 1.00-1.02; p = 0.007), but not 25(OH)D (OR 0.97, 95 % CI 0.89-1.05; p = 0.425) as an independent predictor for one year mortality. 20 % of patients suffered in-hospital postoperative medical complications (i.e. pneumonia, thromboembolic events, etc.). 25(OH)D (OR 0.89, 95 % CI 0.81-0.97; p = 0.010), but not CRP (OR 1.01, 95 % CI 1.00-1.02; p = 0.139), was identified as an independent risk factor. CONCLUSION: In elderly patients with low-energy cervical hip fracture, 25(OH)D is independently associated with postoperative medical complications and CRP is an independent predictor of one year mortality.

A biomechanical evaluation of methods of distal humerus fracture fixation using locking compression plates versus conventional reconstruction plates.

OBJECTIVES: To examine the biomechanical behavior of 2 techniques of double-plate osteosynthesis for fractures of the adult distal humerus using conventional reconstruction plates and locking compression plates. DESIGN: Basic science study. SETTING: Experimental in vitro study. PATIENTS/PARTICIPANTS: Forty fresh-frozen human distal humeri specimens. INTERVENTION: Four matched groups with 10 humeri each, median age 74 years (46-95), were created using similar bone mineral density values. Two standard configurations of double-plate osteosynthesis (dorsal or 90 degrees configuration) with either conventional reconstruction plates or locking compression plates were studied for biomechanical properties of the constructs. A fracture model with a 5-mm supracondylar osteotomy gap simulating metaphyseal comminution (AO type 13-A3.3) was used. MAIN OUTCOME MEASUREMENT: Stiffness testing of the constructs in anterior/posterior bending, torsion, and axial compression loading. Evaluation of alterations of the bone-implant interface and failure patterns under cyclic loading and strength testing. RESULTS: The study demonstrates that primary stiffness in anterior/posterior bending and torsional loading is significantly increased by using locking compression plates in a 90 degrees configuration (P < 0.05) as compared with dorsally applied plates. The differences between the different plate types are insignificant if applied in the same configuration. It is demonstrated that none of the tested implants failed under cyclic loading within the number of cycles expected for 3 months of use. The bone-implant interface is less likely to fail during strength testing with locking compression plates. CONCLUSION: The biomechanical behavior of the osteosynthesis depends more on plate configuration than plate type. Advantages of locking compression plates are only significant if compared with dorsal plate application techniques. Nevertheless, locking compression plates are helpful supplementary tools for achieving primary stable fracture fixation. This might be of considerable clinical relevance in patients with diminished bone mineral quality or in the presence of metaphyseal comminution.