Henrique Cabrita

Post-Operative Delirium Is Associated with Poor Cognitive Outcome and Dementia

The objective of the present study is to evaluate the association between the occurrence of delirium and the cognitive outcome in elderly subjects. Hospital files of 572 patients who underwent hip or knee replacement between 1998 and 2004 were examined. A sample of 90 elderly subjects (31 with evidence of post-operative delirium), non-demented at baseline, was screened for cognitive decline and dementia. Diagnosis of dementia was highly associated with the occurrence of delirium. The relative risk for the diagnosis of dementia among subjects with previous history of delirium, according to the IQcode screening, was 10.5 (95% CI: 3.3–33.2). Such patients had a significantly higher mean IQcode score (3.75) as compared to controls (3.1; p < 0.001). Cognitive functions most affected in these patients were memory, orientation and abstract thinking. We conclude that the occurrence of post-operative delirium in cognitively unimpaired elderly subjects is associated with a worse cognitive outcome and an increased risk of dementia.

Prospective study of the treatment of infected hip arthroplasties with or without the use of an antibiotic-loaded cement spacer

PURPOSE Our purpose was to compare 2 methods of treatment of chronic infection in hip arthroplasties--with or without an antibiotic-loaded cement spacer. METHODS In a prospective study, we treated 68 infected hip arthroplasties with discharging sinuses and bone loss, comparing 30 patients treated in 2 stages without the use of a spacer (control group) and 38 patients treated with a vancomycin-loaded spacer (study group). The average follow-up was 4 years (2-8.5 years). One patient died of unrelated causes 4 months after first-stage surgery and was excluded from the study. RESULTS The 2-stage surgery without spacer controlled the infection in 66.7% of patients, and the 2-stage surgery using the spacer controlled it in 89.1% (P < 0.05). At last follow-up, the average Harris Hip Score increased from 19.3 to 69.0 in the control group versus 19.7 to 75.2 in the study group (P > 0.05). The average leg length discrepancy was 2.6 cm in the control group and 1.5 cm in the study group (P < 0.05). The patients treated with a spacer had better clinical results (81.5% of patients with good results against 60.0% for the control group). CONCLUSION The use of an antibiotic-loaded spacer in the 2-stage treatment of infected hip arthroplasties provides better infection control with good functional results and is superior to treatment in 2 stages without a spacer. LEVEL OF EVIDENCE Therapeutic study, Level I-1.

Periprosthetic Joint Infections

Implantation of joint prostheses is becoming increasingly common, especially for the hip and knee. Infection is considered to be the most devastating of prosthesis-related complications, leading to prolonged hospitalization, repeated surgical intervention, and even definitive loss of the implant. The main risk factors to periprosthetic joint infections (PJIs) are advanced age, malnutrition, obesity, diabetes mellitus, HIV infection at an advanced stage, presence of distant infectious foci, and antecedents of arthroscopy or infection in previous arthroplasty. Joint prostheses can become infected through three different routes: direct implantation, hematogenic infection, and reactivation of latent infection. Gram-positive bacteria predominate in cases of PJI, mainly Staphylococcus aureus and Staphylococcus epidermidis. PJIs present characteristic signs that can be divided into acute and chronic manifestations. The main imaging method used in diagnosing joint prosthesis infections is X-ray. Computed tomography (CT) scan may assist in distinguishing between septic and aseptic loosening. Three-phase bone scintigraphy using technetium has high sensitivity, but low specificity. Positron emission tomography using fluorodeoxyglucose (FDG-PET) presents very divergent results in the literature. Definitive diagnosis of infection should be made by isolating the microorganism through cultures on material obtained from joint fluid puncturing, surgical wound secretions, surgical debridement procedures, or sonication fluid. Success in treating PJI depends on extensive surgical debridement and adequate and effective antibiotic therapy. Treatment in two stages using a spacer is recommended for most chronic infections in arthroplasty cases. Treatment in a single procedure is appropriate in carefully selected cases.

Acetabular Component Positioning in Total Hip Arthroplasty With and Without a Computer-Assisted System: A Prospective, Randomized and Controlled Study

In a study of the acetabular component in total hip arthroplasty, 20 hips were operated on using imageless navigation and 20 hips were operated on using the conventional method. The correct position of the acetabular component was evaluated with computed tomography, measuring the operative anteversion and the operative inclination and determining the cases inside Lewinneks safe zone. The results were similar in all the analyses: a mean anteversion of 17.4° in the navigated group and 14.5° in the control group (P=.215); a mean inclination of 41.7° and 42.2° (P=.633); a mean deviation from the desired anteversion (15°) of 5.5° and 6.6° (P=.429); a mean deviation from the desired inclination of 3° and 3.2° (P=.783); and location inside the safe zone of 90% and 80% (P=.661). The acetabular component positions tomography analyses were similar whether using the imageless navigation or performing it conventionally.

Anterograde removal of broken femoral nails without opening the nonunion site: a new technique

OBJECTIVE: We describe a new technique for removing the distal fragments of broken intramedullary femoral nails without disturbing the nonunion site. METHODS: This technique involves the application of an AO distractor prior to the removal of the nail fragments, with subsequent removal of the proximal nail fragment in an anterograde fashion and removal of the distal fragment through a medial parapatellar approach. Impaction of the fracture site is then performed with a nail that is broader than the remaining fragmented material. RESULTS: Nails were removed from five patients using the technique described above without any complications. After a mean follow-up period of 61.8 months, none of these patients showed worsened knee osteoarthritis. CONCLUSION: The original technique described in this article allows surgeons to remove the distal fragment of fractured femoral intramedullary nails without opening the nonunion focus or using special surgical instruments.

Aseptic Loosening of Total Hip Arthroplasty: Preliminary Genetic Investigation

Femoral and acetabular loosening can be attributed different factors, but the causes and mechanism of early failure are still obscure. The objective of this study was to investigate the relationship between gene polymorphisms and early implant failure. Fifty-eight patients older than 50 years was recruited for analysis of MMP-1 promoter polymorphisms in early osseointegrated implant failure. The results showed in control group a frequency of 20.97% of 2G allele and 67.74% the genotype 1G/1G whereas, in the test group, a frequency of 83.33% of 2G allele and 66.66% the genotype 2G/2G. These results indicate that the polymorphism in the promoter of the MMP-1 gene could be a risk factor for early implant failure of total hip arthroplasty.

A comparative radiographic investigation of femoroacetabular impingement in young patients with and without hip pain

OBJECTIVE: To compare the existence of radiographic abnormalities in two groups of patients, those with and without hip pain. METHODS: A total 222 patients were evaluated between March 2007 and April 2009; 122 complained of groin pain, and 100 had no symptoms. The individuals in both groups underwent radiographic examinations of the hip using the following views: anteroposterior, Lequesne false profile, Dunn, Dunn 45°, and Ducroquet. RESULTS: A total of 1110 radiographs were evaluated. Female patients were prevalent in both groups (52% symptomatic, 58% asymptomatic). There were statistically significant differences between the groups in age (p<0.0001), weight (p = 0.002) and BMI (p = 0.006). The positive findings in the group with groin pain consisted of the presence of a bump on the femoral head in the anteroposterior view (p<0.0001) or in the Dunn 45° view (p = 0.008). The difference in the α angle in the anteroposterior, Dunn, Dunn 45°, and Ducroquet views for all of the cases studied was p<0.0001. The joint space measurement differed significantly between groups in the Lequesne view (p = 0.007). The Lequesne anteversion angle (ρ) and the femoral offset measurement also differed significantly (p = 0.005 and p = 0.0001, respectively). CONCLUSIONS: We conclude that the best views for diagnosing a femoroacetabular impingement are the anteroposterior pelvic orthostatic, the Dunn 45°, and the Ducroquet views. The following findings correlated with hip pain: a decrease in the femoral offset, an increase in the α angle, an increase in the Lequesne ρ angle, a decrease in the CE angle of Wiberg, a thinner articular space and the presence of a bump on the femoral head-neck transition.