Granulomatosis with polyangiitis according to geographic origin and ethnicity: clinical-biological presentation and outcome in a French population.

Objectives: Granulomatosis with polyangiitis (GPA) mainly affects white Europeans, but rarely GPA may also affect non-Europeans. This study aimed to describe GPA clinical-biological presentation and outcome in black sub-Saharan Africans and Afro-Caribbeans and in North Africans. Methods: Among 914 GPA patients included in the French Vasculitis Study Group database, geographic origin and ethnicity were known for 760. Clinical-biological presentations and outcomes of white Europeans vs black sub-Saharans and Afro-Caribbeans and vs North Africans were analysed. Results: Among the 760 patients, 689 (91%) were white Europeans, 33 (4.3%) were North Africans and 22 (2.9%) were sub-Saharans (n = 8) or Afro-Caribbeans (French West Indies, n = 14). Black sub-Saharans and Afro-Caribbeans, compared with white Europeans, were significantly younger at GPA diagnosis (P = 0.003), had more frequent central nervous system involvement (P = 0.02), subglottic stenosis (P = 0.002) and pachymeningitis (P = 0.009), and tended to have more frequent chondritis and retroorbital tumour. Median serum creatinine levels and Birmingham Vasculitis Activity Score were significantly lower in sub-Saharans and Afro-Caribbeans (P = 0.002 and P = 0.003, respectively). In contrast, in comparison with white Europeans, North Africans had only less frequent arthralgias (P = 0.004). Time to relapse was shorter for black sub-Saharans and Afro-Caribbeans compared with white Europeans [adjusted HR = 1.96 (95% CI: 1.09, 3.51) (P = 0.02)], and did not differ for North Africans. In contrast, overall survival was not significantly different according to ethnicity. Conclusion: Our findings indicated different GPA clinical presentations in white Europeans and sub-Saharans and Afro-Caribbeans, with black patients having more frequent severe granulomatous manifestations. In addition, time to relapse was significantly shorter for black sub-Saharans and Afro-Caribbeans compared with white Europeans.

Clinical and Radiological Changes after Microfracture of Knee Chondral Lesions in Middle-Aged Asian Patients.

BACKGROUND: Although microfracture is widely accepted as an effective treatment option for knee chondral lesions, little is known about the deterioration of clinical outcomes and radiological progression in middle-aged patients. Therefore, this study was conducted to evaluate the clinical and radiological changes after microfracture of knee chondral lesions in middle-aged Asian patients. METHODS: A total of 71 patients were included in the study. They were between the ages of 40 and 60 years and underwent arthroscopic microfracture for localized full-thickness cartilage defects of the knee from January 2000 to September 2015. The recovery status of chondral lesions was assessed by using the magnetic resonance observation of cartilage repair tissue (MOCART) score in postoperative magnetic resonance imaging (MRI). Clinical and radiological results were reviewed, and survival rate with conversion to arthroplasty or osteotomy as an end point was evaluated. RESULTS: The mean age of the patients at surgery was 51.3 ± 4.7 years (range, 40 to 60 years), and the mean follow-up period was 7.2 ± 2.6 years (range, 1.0 to 17.4 years). The MOCART scores of 32 patients at mean postoperative 2.1 years showed three cases (9%) of full recovery, two cases (7%) of hyperplastic recovery, 23 cases (70%) with more than 50% filling, and four cases (14%) with less than 50% filling. Clinical scores improved significantly at 1 year after surgery (p < 0.05); however, the scores deteriorated over time after postoperative 1 year, and the mean values reached preoperative levels at postoperative 10 years. Significant radiological progression of arthritis (Kellgren-Lawrence grade) was observed at 5 years after surgery. Four patients underwent total knee arthroplasty during follow-up. CONCLUSIONS: Most patients showed more than 50% of defect filling at 2 years after surgery on MRI. Clinical results of microfracture of knee chondral lesion showed the best improvement at postoperative 1 year but gradually worsened thereafter until postoperative 10 years. Radiological progression of arthritis was observed from 5 years after surgery.

How critical are the tibiofemoral joint reaction forces during frequent squatting in Asian populations?

This study examines tibiofemoral joint moments and forces when performing a squat. The relevance of studying such an activity is to understand better the mechanical factors involved in the higher incidence of tibiofemoral osteoarthritis in Asian populations where squatting is a common daily activity. In this study, motion analysis data of walking versus squatting were compared, specifically looking at net external knee flexion moments, ground reaction forces and tibiofemoral contact forces. It was found that while squatting resulted in more than 2.5 times larger peak external moments compared with walking, tibiofemoral contact forces were not significantly different. This was due to reduced ground reaction forces recorded for the squatting phase compared to the larger dynamic effects of deceleration at heel strike during walking. The most significant finding of this study was that in squatting, there was a reversal in the tibiofemoral shear reaction force from posterior-directed to anterior-directed, occurring under full compressive load and within a fraction of a second. It is believed that repeated squatting results in many such reversals in shear reactions that may ultimately have significant implications to the long term mechanical function and structural integrity of the joint cartilage.

Bone disease in African children with slipped capital femoral epiphysis: histomorphometry of iliac crest biopsies.

African teenagers with slipped capital femoral epiphysis (SCFE) not infrequently also have genu valgum (knock-knee). Because we had previously demonstrated metabolic bone disease attributable to dietary calcium deficiency in black teenagers with genu valgum, we examined 29 black teenagers (15 male, 14 female) with SCFE for metabolic bone disease. Each patient had an iliac crest bone biopsy taken (after double tetracycline labeling) for routine histomorphometry, and blood and urine samples for bone biochemistry. Spinal bone mineral density was measured in 13 patients. Compared to reported data, we found our patients to be sexually more immature, older, at least as obese, and to have more severe and more frequently bilateral hip disease. Eighty percent of the children took dairy products only once or twice a week or less frequently, and 37.9% had genu valgum. Compared with race- and age-matched South Africans, bone biopsies in our patients showed lower bone volume (BV/TV, p = 0.0003), wall thickness (p = 0.0002), and trabecular thickness (Tb.Th, p = 0.0002), and a tendency to greater trabecular spacing (Tb.Sp, p = 0.053). Lower osteoid volume (OV/BV, p = 0.0001), osteoid surface (OS/BS, p = 0.0001), osteoid thickness (O.Th, p = 0.0002), double labeled surface (dLS/BS, p = 0.029), and bone formation rate (BFR/BS, p = 0.037) suggested poorer bone forming capacity in our patients. No evidence of hyperparathyroid bone disease or osteomalacia was found. BV/TV was below the reference range (14.2%) in 65.5% of cases; these patients had lower values for Tb.Th (p = 0.037) and Tb.N (p = 0.0003), greater Tb.Sp (p = 0.0002), a tendency to lower adjusted apposition rate (Aj.AR, p = 0.057), and had had less frequent intake of dairy products than those with normal BV/TV (p = 0.024). Furthermore, months since menarche correlated with histomorphometric variables BV/TV (r = 0.667, p = 0.009), Tb.Th (r = 0.745, p = 0.002), Tb.Sp (r = -0.549, p = 0.042), O.Th (r = 0.784, p = 0.0009), and Aj.AR (r = 0.549, p = 0.042). The correlation between Tb.Th and spinal bone mineral content (r = 0.656, p = 0.015) suggests that the reduced trabecular thickness reflected a generalized bone condition. A greater than normal proportion of patients had spinal bone mineral density values below -1 standard deviation (SD) of the mean (osteopenia) (p = 0.001). Patients tested for parathyroid hormone and 25-hydroxyvitamin D levels were found to have normal values. Parathyroid hormone correlated with Aj.AR (r = 0.661, p = 0.038) and serum phosphorus (r = -0.764, p = 0.010). We conclude that sexual immaturity and possibly past dietary calcium deficiency contributed to osteopenia, and that this, together with obesity, led to the development of more severe and more frequently bilateral SCFE in our patients than in reported series of black and white children.

Slipped capital femoral epiphysis in black children: incidence of chondrolysis.

The risk of chondrolysis and avascular necrosis (AVN) in black children treated for slipped capital femoral epiphysis (SCFE) is controversial. A retrospective study was conducted of 29 black patients (44 hips) treated for SCFE at Kings County Hospital, Brooklyn, New York, to evaluate our own experience. All patients were treated with in situ pinning. The overall rates of chondrolysis and AVN were 6.8 and 4.5%, respectively. Fifty-two percent of patients had bilateral SCFE. Obesity was extremely common and correlated significantly with bilateral disease. Obesity did not correlate directly with a higher incidence of chondrolysis or AVN. Adherence to technical details described should reduce complications further.