Midterm results of modular hinge total knee arthroplasty using cementless osseointegrating stems: low fixation associated complications and good functional outcome in primary and revision knee arthroplasty

PURPOSE

This study aimed to investigate functional outcome and complications after primary and revision modular H-TKA using hybrid fixation with cementless stems.

METHODS

Between 2015 and 2018, 48 patients with 50 implants were included after hybrid implantation of a single design H-TKA system using cementless osseointegrating stems and modular components. Complications and clinical outcome were analysed using Knee Society Score (KSS), the Western Ontario McMasters Universities Osteoarthritis Index (WOMAC) and the Short-Form Health Survey 12 (SF-12) score.

RESULTS

Indications for implantation were aseptic revision (n = 29, 58%), primary TKA (n = 19, 38%) and two-stage septic revisions (n = 2, 4%). Complications were reported in 26% (n = 12), whereas complications associated with hybrid fixation occurred in 5 (10%) cases, with 2 (4%) requiring revision surgery for aseptic loosening and 3 (6%) treated with an adapted postoperative protocol for perioperative fractures. Implant survivorship was 84% after a mean follow-up of 54 months. Postoperative KSS significantly improved from 51.50 (12-100) to 78.36 (41-99; p < 0.001). The mean WOMAC score was 19.26 (0-55), SF-12 PCS was 41.56 points (22.67-57.66) and SF-12 MCS was 49.21 points (23.87-63.21).

CONCLUSION

Hybrid modular implantation in H-TKA provides satisfactory clinical and functional results in primary and revision TKA. Clinical outcomes significantly improve with reduced pain, increased mobility, and good-to-excellent functional scores after implantation. Whilst implant survival is comparable to previous studies and complications associated with hybrid fixation are low, general complication rates are comparably high.

Effects of the antiandrogen, cyproterone acetate, on the induction of papillomas, DNA synthesis and ornithine decarboxylase activity in mouse skin

The antiandrogen, cyproterone acetate (CPA), applied simultaneously with 12-O-tetradecanoylphorbol-13-acetate (TPA) to the dorsal skin of male and female SENCAR mice initiated with 7,12-dimethylbenz[a]anthracene inhibited the production of papillomas of the skin. Although 125 and 250 micrograms of CPA had no effect on the incidence of papillomas per mouse, 500 micrograms of CPA inhibited papilloma production by 95% and 91% in female mice after 20 and 37 weeks of promotion, respectively. Testosterone propionate only partially blocked the inhibitory effect of CPA. In male mice 500 micrograms and 1 mg of CPA inhibited papilloma production by 77% and 88%, respectively. In the two-stage promotion protocol 500 micrograms of CPA was ineffective as an inhibitor when it was applied with TPA during the 1st stage but inhibited papilloma production by 71% when it was applied with mezerein during the 2nd stage. CPA was also observed to inhibit TPA-stimulated epidermal DNA synthesis and inflammation but had no effect on TPA-induced epidermal ornithine decarboxylase activity.

The contribution of internal scatter to radiation dose during CT scan of the head

An acrylic head phantom was irradiated during a computed tomographic scan with four commercial scanners. Measurements of the spatial distribution of the radiation dose on the surface and internal to the phantom were performed for the scan plane and the scattered beam at various distances from the scan plane. The surface scatter dose was found to be considerably smaller than that for internal scatter. A significant increase in radiation exposure within the head phantom due to internal radiation scatter, and an asymmetrical primary beam profile for dual slice scanners were also noted.

Storage of platelets prepared by discontinuous flow centrifugation

Platelet concentrates were prepared by plateletpheresis using discontinuous flow centrifugation. Platelet units were stored in PL-146 bags of 300 ml and 2,000 ml capacity, and in vitro measures helpful in predicting platelet viability were compared. Storage in bags of 300 ml capacity led to significant fall in pH, decreased recovery from osmotic stress, and deterioration of morphology in 24 hours. Storage lesions were significantly decreased by use of 2,000 ml capacity bags.