Is primary total hip arthroplasty in patients with Down's syndrome associated with increased complications at 2 years follow-up?

INTRODUCTION: Previous reports on primary total hip arthroplasty (THA) in patients with Down's syndrome (DS) are often small and/or lack a comparison cohort, and thus it is challenging to draw meaningful conclusions about this group. The purpose of this study was to report on the post-operative complications in patients with DS undergoing primary THA, compared to a non-DS cohort. METHODS: In this retrospective study, we evaluated patients from 2010 to 2018 using a national database. We assessed surgical complications: closed reduction for dislocation, revision, resection, periprosthetic fracture, and infection in patients with a diagnosis of DS undergoing primary THA and compared them to a THA group of patients without DS. Patients undergoing THA for hip fractures were excluded. Complications were evaluated at 90 days and 2 years. Multivariable logistic regression analysis was used to adjust for age, sex, body mass index, and Charlson comorbidity index. RESULTS: At 90 days patients with DS had an increased risk of revision (OR 3.1, CI 1.14-8.41), but no significant risk of resection (OR 5.24, CI 0.73-37.8), closed reduction (OR 2.03, CI 0.28-14.59), infection (OR 1.48, CI 0.6-3.62), or periprosthetic fracture (OR 1.97, CI 0.27-14.14). At 2 years patients with DS had an increased risk of periprosthetic fracture (OR 5.88, CI 1.84-18.78), but no significant increased risk of revision (OR 1.82, CI 0.66-5.01), resection (OR 2.37, CI 0.33-17.17), or infection (OR 0.65, CI 0.2-2.07). CONCLUSIONS: Primary THA in patients with DS is associated with increased 90-day revision, and periprosthetic fracture at 2 years.

Percent Body Fat Is More Predictive of Function After Total Joint Arthroplasty Than Body Mass Index.

BACKGROUND: Obesity has an important impact on the future of total joint arthroplasty; however, the definition and influence of obesity on surgical risks and outcomes remain controversial. Our hypothesis was that percent body fat was better than body mass index (BMI) at identifying clinical risks and patient-reported functional outcomes following arthroplasty. METHODS: Clinical and functional outcomes were collected prospectively in 215 patients undergoing primary total knee arthroplasty (115 patients) or total hip arthroplasty (100 patients) at a mean time of twenty-four months (range, twelve to forty months). Clinical data included patient demographic characteristics, preoperative evaluation including measurements of BMI and percent body fat, intraoperative records, hospital course or events, and postoperative outpatient follow-up. Patient-reported outcomes were obtained through a series of questionnaires: a surgical satisfaction survey; the University of California, Los Angeles (UCLA) activity scale; the Knee Injury and Osteoarthritis Outcome Score (KOOS) for total knee arthroplasty; and the Hip Disability and Osteoarthritis Outcome Score (HOOS) for total hip arthroplasty. Multivariable regression models were used to identify significant body mass predictors of outcomes (p < 0.05). RESULTS: Higher percent body fat predicted occurrence of any medical or surgical complication (odds ratio per one standard deviation increase, 1.58 [95% confidence interval, 1.04 to 2.40]; p = 0.033). Percent body fat was also a predictor of the UCLA activity score (risk ratio, 0.92 [95% confidence interval, 0.85 to 0.98]; p = 0.013) and pain scores (risk ratio, 1.18 [95% confidence interval, 1.03 to 1.36]; p = 0.017), and it trended toward significance for the surgical satisfaction score (odds ratio, 1.96 [95% confidence interval, 0.93 to 4.15]; p = 0.078), whereas BMI was not predictive of these functional outcomes. Additionally, with regard to surgical procedure-specific outcome scores, percent body fat was predictive of outcomes after total knee arthroplasty (KOOS pain, p = 0.015, and KOOS activities of daily living, p = 0.002), but not for those after total hip arthroplasty. CONCLUSIONS: Percent body fat should be considered when predicting clinical and functional outcomes at two years following total joint arthroplasty. Percent body fat may help surgeons to improve risk stratifications, to project patient-reported functional outcomes, and to better educate obese patients with regard to postoperative expectations prior to undergoing elective total joint arthroplasty. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Fracture of an uncemented tantalum patellar component.

A 62-year-old man presented with the acute, atraumatic onset of pain 3 years after uncemented right total knee arthroplasty. He complained of new mechanical locking with the knee held in extension on examination and unable to flex the knee. On the plain radiographs, the patellar component peg was fractured and the plate was dislocated. The knee was immobilized, and revision to a cemented 3-peg component was performed. Fracture of a single-peg, tantalum-backed uncemented patellar component has not been described. Clinical suspicion for this should be given in the setting of acute locking. We recommend revision with a cemented polyethylene component.

Treatment of osteonecrosis of the femoral head with vascularized bone grafting.

Osteonecrosis of the femoral head (ONFH) is a challenging diagnosis for the patient and treating surgeon. Though its cause is poorly understood, several methods of surgical treatment exist and are performed with variable success. Vascularized bone grafting is one such treatment that attempts to restore viable bone, structural support, and blood supply to the avascular portion of the femoral head. This review summarizes the various approaches to this technique that have been proposed and put into practice. The cost effectiveness of these procedures, both in time and resources, has been evaluated and found to be favorable. The use of revascularization procedures, along with the introduction of other potentiating factors, may signal an exciting future for this debilitating disease process.

Inherited thrombocytopenia due to GATA-1 mutations.

The GATA family of transcription factors, including the founding member, GATA-1, have an important role in gene regulation. GATA-1 is integral to successful hematopoiesis. A wide variety of mutations in GATA-1 affect its function, as well as its interaction with its cofactors (especially Friend of GATA) and the genes upon which GATA-1 acts. Here we review the known mutations, focusing on the specific alterations within the amino acid sequence, the resulting effect on hematopoietic development, and the clinical manifestations that result. Attention is also paid to the relationship between Trisomy 21, also known as Down syndrome, and the phenomenon of a truncated GATA-1, named GATA-1s. The evidence for specific interaction between GATA-1 and chromosome 21, which may explain the correlation between these two mutations, is briefly reviewed.