Revision total hip arthroplasty by a ceramic bearing surface after a third- and fourth-generation ceramic head or liner fracture.

PURPOSE: Although rare, fractures of ceramic components are difficult to revise, mainly due to the presence of residual ceramic debris that can cause catastrophic wear of the replacement components. Modern ceramic-on-ceramic bearings are suggested to improve outcomes of revision total hip arthroplasty (THA) for ceramic fractures. However, there are few published reports of mid-term outcomes of revision THA using ceramic-on-ceramic bearings. We evaluated clinical and radiographic outcomes of 10 patients who received ceramic-on-ceramic bearings during revision THA for ceramic fractures. METHODS: All patients but one received fourth-generation Biolox Delta bearings. Clinical evaluation was performed using the Harris hip score at latest follow-up, and all patients received a radiographic evaluation to analyze the fixation of the acetabular cup and of the femoral stem. Osteolytic lesions and the presence of ceramic debris were noted. RESULTS: After a mean follow-up of 8.0 years, there were no complications or implant failures, and all patients reported satisfaction with their implant. The average Harris hip score was 90.6. There was neither osteolysis nor loosening, but despite our extensive synovial debridement, ceramic debris was noted in the radiographs of five patients (50%). CONCLUSION: We report excellent mid-term outcomes, with no implant failures after eight years despite ceramic debris being found in a significant proportion of patients. We conclude that modern ceramic-on-ceramic bearings are an advantageous option for the revision of THA due to the fracture of initial ceramic components.

Combining acetabular and femoral morphology improves our understanding of the down syndrome hip.

BACKGROUND: Hip instability is frequent in patients with Down syndrome. Recent studies have suggested that skeletal hip alterations are responsible for this instability; however, there are currently no studies simultaneously assessing femoral and acetabular anatomy in subjects with Down syndrome in the standing position. The aim was to analyze the three-dimensional anatomy of the Down syndrome hip in standing position. METHODS: Down syndrome subjects were age and sex-matched to asymptomatic controls. All subjects underwent full body biplanar X-rays with three-dimensional reconstructions of their pelvises and lower limbs. Parameter means and distributions were compared between the two groups. FINDINGS: Forty-one Down syndrome and 41 control subjects were recruited. Acetabular abduction (mean = 52° [SD = 9°] vs. mean = 56° [SD = 8°]) and anteversion (mean = 14° [SD = 8°] vs. mean = 17.5° [SD = 5°]) as well as posterior acetabular sector angle (mean = 91° [SD = 7°] vs. mean = 94° [SD = 7°]) were significantly lower in Down syndrome subjects compared to controls (P < 0.01). Anterior acetabular sector angle (mean = 62° [SD = 10°] vs. mean = 59° [SD = 7°]; P < 0.01) was significantly higher in Down syndrome compared to controls. The distributions of acetabular anteversion (P = 0.002;V = 0.325), femoral anteversion (P = 0.004;V = 0.309) and the instability index (P < 0.001;V = 0.383) were significantly different between the two groups, with subjects with Down syndrome having both increased anteversion and retroversion for each of these parameters. INTERPRETATION: Subjects with Down syndrome were found to have a significantly altered and more heterogeneous anatomy of their proximal hips compared to controls. This heterogeneity suggests that treatment strategies of hip instability in Down syndrome should be subject-specific and should rely on the understanding of the underlying three-dimensional anatomy of each patient.

Spinopelvic Alignment in Subjects With Down Syndrome.

STUDY DESIGN: This was a cross-sectional study. OBJECTIVE: The aim of this study was to describe the spinopelvic alignment of subjects with Down syndrome (DS). SUMMARY OF BACKGROUND DATA: Subjects with DS are known to suffer from a large prevalence of scoliosis. While scoliosis is known to significantly affect postural alignment, there are currently no studies on the spinopelvic alignment of subjects with DS. MATERIALS AND METHODS: In total, 41 subjects (28 female subjects and 13 male subjects) with DS, age and sex-matched to 41 asymptomatic subjects, underwent biplanar x-rays with 3-dimensional reconstructions of their spines and pelvises, followed by measurement of commonly used spinopelvic sagittal and coronal alignment parameters. Subjects were then classified into one of Roussouly's 4 types of sagittal alignment. Alignment parameters and prevalence of alignment patterns were compared between the 2 groups. RESULTS: Subjects with DS were found to be relatively hypokyphotic (T4-T12=-29.0 vs. -37.5 degrees; P<0.001) and hyperlordotic (L1-L5=53.8 vs. 44.3 degrees; P<0.001) with larger pelvic incidence (53.2 vs. 45.1 degrees; P<0.001), sacral slope (47.7 vs. 36.8 degrees; P<0.001), Cobb angle (10.2 vs. 8.0 degrees; P=0.005), and axial rotation of the apical vertebra (6.6 vs. 3.7 degrees; P<0.001) but had smaller pelvic tilt (4.9 vs. 8.1 degrees; P<0.001) compared with control subjects. Roussouly's type 4 was found to be the most frequent pattern in DS subjects (68.3% vs. 14.6%; P<0.001). CONCLUSIONS: Subjects with DS were found to have a peculiar pattern of hypokyphosis, hyperlordosis, large pelvic incidence, and small pelvic tilt. The altered spinopelvic alignment found in DS could predispose these subjects to hip instability and osteoarthritis. LEVEL OF EVIDENCE: Level III.

Is progressive lengthening of the distal phalanx of a child's index finger possible and safe?

Progressive lengthening using an external fixator has only recently been applied to the phalanges of the hand. A number of technical challenges exist, especially in pediatric cases, such as the size of the bone involved, the existence of the physis, and the risk of infection and neurovascular compromise. Here, we report a case of lengthening of a short distal phalanx following osteomyelitis in a 7-year-old child with a uniplanar mini-external fixator. Elongation of 63% was obtained, reaching 80% of the contralateral phalanx, with complete resolution of the preoperative functional impairment, and an acceptable cosmetic result for the patient. A mild limitation of the distal interphalangeal joint flexion as well as mild effort-related discomfort was still present at the last follow-up. No complications were recorded. Gradual lengthening of the phalanges using uniplanar minifixators can be performed safely in children with good results as long as appropriate indications and technical limitations are respected.