After a minimum of six years of follow-up, this cementless total hip arthroplasty with contemporary alumina bearings was found to be a promising procedure for young, active patients with osteonecrosis of the femoral head. However, we remain concerned about the long-term implications of the noise that was reported in these hips.

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Abbreviations: Aβ, Amyloid β-peptide; AD, Alzheimer's disease; CDK, cyclin-dependent kinase; DMEM, Dulbecco's modified Eagle's medium; DSCR1, Down syndrome candidate region 1; MTT, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide; RT-PCR, reverse transcription polymerase chain reaction; SDS, sodium dodecylsulfate; SEST2, Hi95/sestrin 2; STC, stanniocalcin; ZFP36L2, zinc finger protein 36. A bstract

Despite significant improvements over the past several decades in diagnosis, treatment and prevention of periprosthetic joint infection (PJI), it still remains a major challenge following total joint arthroplasty. Given the devastating nature and accelerated incidence of PJI, prevention is the most important strategy to deal with this challenging problem and should start from identifying risk factors. Understanding and well-organized optimization of these risk factors in individuals before elective arthroplasty are essential to the ultimate success in reducing the incidence of PJI. Even though some risk factors such as demographic characteristics are seldom changeable, they allow more accurate expectation regarding individual risks of PJI and thus, make proper counseling for shared preoperative decision-making possible. Others that increase the risk of PJI, but are potentially modifiable should be optimized prior to elective arthroplasty. Although remarkable advances have been achieved in past decades, many questions regarding standardized practice to prevent this catastrophic complication remain unanswered. The current study provide a comprehensive knowledge regarding risk factors based on general principles to control surgical site infection by the review of current literature and also share own practice at our institution to provide practical and better understandings.

We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA.