Predictors of return to desired activity 12 months following unicompartmental and total knee arthroplasty

Background and purpose — 1 in 5 patients are dissatisfied following unicompartmental or total knee arthroplasty (UKA or TKA). This may be partly explained by failing to return to desired activity post-arthroplasty. To facilitate return to desired activity, a greater understanding of predictors of return to desired activity in UKA and TKA patients is needed. We compared rates of return to desired activity 12 months following UKA vs. TKA, and identified and compared predictors of return to desired activity 12 months following UKA vs. TKA.

Patients and methods — Patients were prospectively recruited from 2 hospitals prior to undergoing UKA or primary TKA. Patients reported preoperatively the activity/activities that were limited due to their knee that they wished to return to after arthroplasty. At 12-months postoperatively, patients reported whether they had returned to these activities (‘return to desired activity’). Preoperative predictors evaluated were age, sex, BMI, education, comorbidities, pain expectations, Oxford Knee Score (OKS), UCLA Activity Score, and EQ-5D. Generalized linear models assessed the relationship between potential predictors and return-to-desired-activity.

Results — The response rate of all patients eligible for 12-month follow-up was 74%. TKA patients (n = 575) were older (mean (SD) 70 (9) vs. 67 (10)) with a greater BMI (31 (6) vs. 30 (5)) than patients undergoing UKA (n = 420). 75% of UKA and 59% of TKA patients returned to desired activity. TKA patients had a greater risk of non-return to desired activity than patients undergoing UKA (risk ratio (95% CI) 1.5 (1.2–1.8)). Predictors of non-return to desired activity following UKA were worse OKS (0.96 (0.93–0.99)), higher BMI (1.04 (1.01–1.08)), and worse expectations (1.9 (1.2–2.8)). Predictors of non-return to desired activity following TKA were worse EQ-5D (0.53 (0.33–0.85)) and worse OKS (0.98 (0.96–1.0)).

Interpretation — UKA patients were more likely to return to desired activity than TKA patients. Predictors of return to desired activity differed following UKA and TKA. Optimizing selection of arthroplasty procedure based on patient characteristics and targeting predictors of poor outcome may facilitate return to desired activity with potential to enhance postoperative satisfaction.     

Hereditary persistence of hemoglobin F is protective against red cell sickling. A case report and brief review

Fetal hemoglobin (HbF) is a physiologic protein tetramer that is crucial for a developing fetus to survive in utero. Maternal hemoglobin has a relatively lower affinity for oxygen, and thus allows for an efficient transfer of oxygen from maternal to fetal blood. In addition to fulfilling a critical physiologic role, HbF is also known to alleviate symptoms of sickle-cell disease (SCD). The concentration of HbF depends on several factors. HbF is elevated in inherited conditions, such as hereditary persistence of HbF, hereditary spherocytosis, and thalassemia. The level of HbF is also increased in acquired states, such as pregnancy, aplastic anemia, thyrotoxicosis, hepatoma, myeloproliferative disorders, or hypoplastic myelodysplastic syndrome. It has been identified that some genetic loci have significant influence on HbF levels. The XmnI polymorphism, the HMIP locus, and the BCL11A gene are responsible for 45% of variations in HbF levels. Although SCD has been well described in the subpopulations of Africa, it is less common in the subpopulations of India. We describe a case of SCD, in which a patient with high HbF level presented at a very late age (27 years old). We presume the patient’s inherently elevated HbF levels were able to compensate for the hypoxic episodes associated with SCD. The onset of symptoms was delayed as a result of elevated HbF levels.     

Coronary Artery Disease in Patients ≥80 Years of Age

Coronary artery disease (CAD) is a major cause of morbidity and mortality in patients ≥80 years of age. Nonetheless, older patients have typically been under-represented in cardiovascular clinical trials. Understanding the pathophysiology, epidemiology, and optimal means of diagnosis and treatment of CAD in older adults is crucial to improving outcomes in this high-risk population. A patient-centered approach, taking into account health status, functional ability and frailty, cognitive skills, and patient preferences is essential when caring for older adults with CAD. The present systematic review focuses on the current knowledge base, gaps in understanding, and directions for future investigation pertaining to CAD in patients ≥80 years of age.