Clinical and radiographic short mid-term outcomes of primary total stabilizer knee arthroplasty

A successful Total Knee Arthroplasty (TKA) requires stability, but rarely in primary TKA, a prosthesis with more constraint than a posterior-stabilizer (PS) is necessary. In patients with severe varus/valgus deformities with incompetent collateral ligaments or in knees that cannot be adequately balanced after ligaments release, a total-stabilizer (TS) prosthesis may be required. The purpose of our retrospective study is to evaluate clinical and radiographic outcomes at short mid-term follow-up in patients treated with a TS TKA. Between January 2013 and August 2016, 36 patients (38 knees) were treated with Stryker Triathlon TS cemented implants. Clinical and radiographic evaluation were performed preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year and at 1-year intervals thereafter. At final follow-up, 33 patients (35 knees) remained and were included in this study and followed with a mean follow-up of 26.6 months. Clinical evaluation was performed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC score) and the Knee Society rating system that is subdivided into a knee score (KS) that rates only the knee joint itself and a functional score (FS). Knee Score (KS) and Functional Score (FS) increased significantly from a mean pre-operative value of 48 and 45, respectively, to a post-operative value at last follow-up of 86 and 82, respectively. Also WOMAC score improved significantly: the mean pre-operative WOMAC score was 45, while the mean post-operative WOMAC score, at last follow-up, was 19. The difference between pre- and post- operative results was significant at statistical analysis. In our opinion, when the adequately prosthesis balancing isn’t possible, because of primary or secondary severe varus/valgus deformity or severe soft tissues retraction, an available option is to perform a total knee arthroplasty with a total stabilizer polyethylene insert. TS prosthesis gives more stability during the most of ROM and, in addition, Triathlon system provides surgeons the possibility to choose a more constrained implant, than a standard PS one, during surgical procedure saving the bone stock. Our experience with this kind of prosthesis has provided good clinical and radiographic outcomes at a short mid-term follow-up with a low-rate of complications.

Immediate implants placed into infected sites: a histomorphometric study in dogs

The study the effect of chronically infected sites on the immediate placement of implants, periapical lesions were induced in the third and fourth premolars of four dogs and the contralateral teeth were used as controls. Nine months after the induction of periapical lesions, experimental and control teeth were extracted, and 28 IMZ implants were immediately placed. After a healing period of 12 weeks, the animals were sacrificed, the hemimandibles were removed, and specimens were prepared to be hard-sectioned and stained with toluidine blue. All areas healed without inflammation or exudation and all implants were clinically immobile and were radiographically determined to be surrounded by normal-appearing bone. Histologically, there were no signs of infection, and the histomorphometric analyses revealed that 28.6% and 38.7% had osseointegrated for the experimental and control implants, respectively. The difference was not statistically significant. It was concluded that chronically infected sites, such as those showing signs of periapical pathosis, may not be a contraindication for immediate implants, if certain clinical measures and preoperative and postoperative care are taken.

The bonded amalgam restoration: a case report

The development of resin cements for use in fixed prostheses has suggested the possibility of a new direct restorative technique, the bonded amalgam. This restoration technique reportedly reduces microleakage and increases adhesion to dental structure compared to conventional amalgam restorative techniques. Factors such as tooth conservation, occlusion, patient age, and the time required for the execution of this type of restoration should also be considered. An amalgam restoration was placed with the adhesive technique in a 13-year-old patient with a nonvital mandibular left second molar and limited interocclusal space. After 3 years of observation, the restoration shows excellent function, suggesting its appropriateness for special clinical situations.