Both total joint arthroplasty (TJA) and Alzheimer's Disease (AD) are prevalent in elderly populations. It is the goal of this study to determine if the presence of implant metals originating from TJA correlates with the onset with higher implant metal content in the brain and AD pathology.

Tissue samples from four brain regions of 701 (229 with TJA) participants from an ongoing longitudinal cohort study (Rush Memory and Aging Project) was analyzed including the inferior-temporal-cortex (ITC), which is associated with early onset of AD. Implant metal (Co, Cr, Mo, Ti, Al) content was determined by ICP-MS. Comparisons were conducted between the no-TJA-group and a TJA group. Due to the higher likelihood of Co release the TJA group was further differentiated in a THA (N=146) and a TKA/TSA (N=83) group. Diffuse and neuritic amyloid plaques and phosphorylated tau were assessed and summarized as standard measures of AD pathology. We used separate linear regression models adjusted for age, sex, education, and APOɛ4-status for the associations of all metals (log-transformed) with global AD pathology, amyloid plaques, and phosphorylated tau.

The THA group had higher cobalt content across all brain regions (p=0.003) and within the ITC (p=0.051) compared to the no-TJA group, whereas the TKA/TSA group did not. Across all tissue samples, Co was associated with higher amyloid load (β=0.35, p=0.027), phosphorylated tau (β=0.47, p=0.011), and global AD pathology (β=0.19, 0.0004) in the ITC. The presence of TJA itself was not associated with AD pathology.

We showed that only Co content was higher within the ITC in persons with THA. We found among all tested metals that Co was consistently associated with AD pathology. Although we found an association of cobalt with AD pathology, the cross-sectional nature of this study does not allow the determination of cause and effect.

The lateral condylar fractures of the humerus are the second most common injury around the elbow in children. Treatment of patients presenting late is controversial. We report our experience of treatment of these fracture over last thirteen years in 78 children seen between 1987 and 2000. Average age- 5.2 years ; 53 patients presented early and 25 patients presented more than 3 weeks after injury . In latter, 11 patients were treated conservatively and rest by internal fixation. Pseudovarus was observed in 30% cases on long term followup. Of 25 patients presenting late, open reduction, internal fixation with bone grafting was carried out in eight cases (those who presented between 3–6 weeks) and rest of the 17 cases were kept under observation on regular follow up. At final follow up, the cases operated late (n= 8) had preservation of 70–80 % of Flexion Extension Arc. Of the 17 cases kept under observation, 8 (showing non union) developed cubitus valgus. 9 cases (showing malunion) continue to have stiff elbow . The elbow function was better in the former group. We suggest that every effort should be made to fix the lateral condylar fragment in patients presenting even more than 3 weeks especially if the metaphyseal chunk is large, the fragment is not widely displaced and rotated and the fracture is type II Milch in a very young child (as those patients rapidly develop very severe cubitus valgus deformity with translocation of ulna).