224 A 5-Year Observational Study on Distal Femoral Periprosthetic Fractures in Elderly Patients in a Single Institution: Distal Femoral Replacement vs. Internal Fixation

Aim

To evaluate the outcome of distal femoral replacements versus internal fixation for elderly patients with distal femoral periprosthetic fracture in a single institution.

Method

A five-year retrospective observational study was conducted of a consecutive series of patients with distal femoral periprosthetic fracture who underwent either distal femoral replacement (DFR) or internal fixation (IF) in a tertiary referral centre. Clinical information analysed included patient demographics, co-morbidities, interval between primary total knee arthroplasty (TKA) to distal femoral periprosthetic fracture, type of fracture, operative technique, preoperative ASA grade, post-operative complications, intensive therapy unit (ITU) stay, length of hospital stay (LOS), re-fixation and mortality.

Results

Study included 27 patients of which fourteen patients underwent a DFR while 13 underwent an IF. 89% of the patients were females. Mean age of the patients at the time of fracture was 85 versus 80 (DFR vs IF). The mean interval from the primary TKA to the fracture were 80 months (range 0-181). There were no intraoperative complications in either group. Three patients required ITU stay from the DFR group while one patient from the IF group required re-fixation. Median LOS was 56 days (range 9-144) after DFR and 55 days (range 4-83) after IF. There was one 30-day mortality in the DFR group. One-year mortality for the DFR group was 7% vs 15% for the IF group.

Conclusions

In our study, DFR and IF were observed to have similar LOS with a higher mortality in the IF group at one year. There was one re-fixation in the IF group.

Melkersson-Rosenthal syndrome

Melkersson-Rosenthal syndrome (MRS) is a rare idiopathic non-caseating granulomatous condition. It is rarely described in otorhinolaryngology-related journals, although facial palsy, lip-swelling, and lingua plicata, are its most common presenting features. This classical triad however is not always present in MRS. Other forms of orofacial swelling exist. This paper describes a patient with a variant of MRS, treated by us with intra-lesional steroid injection. We also discuss the other differential diagnoses that may mimic MRS.

Involvement of calyculin A inhibitable protein phosphatases in the cyclic AMP signal transduction pathway of mouse corticotroph tumour (AtT20) cells

1. The role of non-calcineurin protein phosphatases in the cyclic AMP signal transduction pathway was examined in mouse pituitary corticotroph tumour (AtT20) cells. 2. Blockers of protein phosphatases, calyculin A and okadaic acid, were applied in AtT20 cells depleted of rapidly mobilizable pools of intracellular calcium and activated by various cyclic AMP generating agonists. Inhibitors of cyclic nucleotide phosphodiesterases were present throughout. The accumulation of cyclic AMP was monitored by radioimmunoassay, phosphodiesterase activity in cell homogenates was measured by radiometric assay. 3. Neither calyculin A nor okadaic acid altered basal cyclic AMP levels but cyclic AMP formation induced by 41 amino acid residue corticotrophin releasing-factor (CRF) was strongly inhibited (up to 80%), 1-Norokadaone was inactive. Similar data were also obtained when isoprenaline or pituitary adenylate cyclase activating peptide1-38 were used as agonists. 4. Pertussis toxin did not modify the inhibition of CRF-induced cyclic AMP production by calyculin A. 5. Pretreatment with calyculin A completely prevented the stimulation of cyclic AMP formation by cholera toxin even in the presence of 0.5 mM isobutylmethylxanthine (IBMX) and 0.1 mM rolipram. Cholera toxin mediated ADP-ribosylation of the 45 K and 52 K molecular weight Gs alpha isoforms in membranes from calyculin A-pretreated cells was enhanced to 150-200% when compared with controls. 6. Cholera toxin-induced cyclic AMP was reduced by calyculin A within 10 min when calyculin A was applied after a 90 min pretreatment with cholera toxin. Under these conditions the effect of calyculin A could be blocked by the combination of 0.5 mM IBMX and 0.1 mM rolipram, but not by 0.5 mM IBMX alone. 7. Phosphodiesterase activity in AtT20 cell homogenates showed a significant, 2.7 fold increase after treatment with calyculin A. In control cells phosphodiesterase activity was blocked by 80% in the presence of IBMX (0.5 mM), or IBMX plus rolipram (0.1 mM). In calyculin A-treated cells phosphodiesterase activity was also strongly inhibited by IBMX, but because of the stimulating effect of calyculin A, the activity remaining was still 55% of that found in control homogenates. This activity was reduced to 5% of control by using IBMX and rolipram in combination. Assay of phosphodiesterase in Ca2+ free conditions showed that calyculin A markedly increases the activity of rolipram sensitive (type 4) phosphodiesterase. 8. Taken together, blockers of protein phosphatases (PPases) impaired signal transduction through Gs-mediated pathways and activated cyclic AMP degrading phosphodiesterase(s), indicating that PPases 1 and/or 2A are essential for agonist-mediated regulation of cyclic AMP levels in AtT20 cells, and are thus important in maintaining the secretory phenotype of the cells.