No abstract

Background Limitations of conventional uncemented femoral stems persist, including proximal-distal mismatch, nonideal load transfer, loss of bone, and difficulties with minimally invasive surgery. Metaphyseal-engaging shortstem implants have been designed to address these issues in THA. While these devices have been studied in younger patients, it is unclear whether they offer advantages in older patients. Questions/purposes We asked whether the stability and bony ingrowth of an off-the-shelf short stem in patients 70 years and older were similar to those achieved in patients younger than 70 years at 2-year followup. Furthermore, we asked whether pain and function scores were affected by age, bone quality, or varus alignment. Patients and Methods We retrospectively reviewed 60 patients (65 hips) 70 years and older (mean, 75 years; range, 70-86 years) treated with an uncemented short stem (range, 90-105 mm). We compared radiographic alignment, stability, and bony ingrowth, as well as Harris hip scores and WOMAC pain scores, to a cohort of 89 patients (91 hips) younger than 70 years. Minimum followup was 24 months (mean, 35 months; range, 24-60 months). Results Radiographs showed proximal bony ingrowth and stable fixation of all implants. Average Harris hip score at last followup was 88 (range, 70-100) for the 70 years and older cohort and 93 (range, 70-100) for younger than 70 years cohort; no patients reported thigh pain. Postoperative WOMAC scores averaged 6 (range, 0-43) and 5 (range, 0-25), respectively.

The synthesis of beta-hydroxy carbonyl compounds is an important goal due to their prevalence in bioactive molecules. A novel approach to construct these structural motifs involves the multicomponent reaction of acylsilanes, amides, and electrophiles. The addition of amide enolates to acylsilanes generates beta-silyloxy homoenolate reactivity by undergoing a 1,2-Brook rearrangement. These unique nucleophiles formed in situ can then undergo addition to alkyl halides, aldehydes, ketones, and imines. The gamma-amino-beta-hydroxy amide products derived from the addition of these homoenolates to N-diphenylphosphinyl imines are generated with excellent diastereoselectivity (> or = 20:1) and can be efficiently converted to highly valuable gamma-lactams. Finally, the use of optically active amide enolates delivers beta-hydroxy amide products with high levels of diastereoselectivity (> or = 10:1).

It takes three: The stereoselective synthesis of highly substituted γ‐lactams from amide enolates, acylsilanes, and imines is reported. This multicomponent reaction accesses γ‐amino‐β‐hydroxy amides in a single flask with good yields and excellent levels of diastereoselectivity (see scheme). Exposure of the linear products to microwave irradiation and acidic conditions promotes a cyclization to form the corresponding γ‐lactams in excellent yields.

Drei Zutaten: Bei der stereoselektiven Synthese hoch substituierter γ‐Lactame aus Amidenolaten, Acylsilanen und Iminen werden die Komponenten zunächst in einer Eintopfreaktion mit guten Ausbeuten diastereoselektiv zu γ‐Amino‐β‐hydroxyamiden verknüpft (siehe Schema). Diese werden dann durch Mikrowellenbestrahlung unter sauren Bedingungen in ausgezeichneten Ausbeuten zu den γ‐Lactamen cyclisiert.