A comparison of clinical outcomes after total knee arthroplasty (TKA) in patients with preoperative nickel allergy receiving Cobalt-Chromium (CoCr) or Nickel-Free Implant

INTRODUCTION

The role of metal hypersensitivity reactions in total knee arthroplasty (TKA) failure is debated. There is no consensus on whether use of a more expensive nickel-free implant is indicated for patients who have pre-operative nickel allergy. The purpose of this study was to examine the outcome of patients who have pre-operative nickel allergy receiving nickel-free or cobalt chromium (CoCr) implants.

METHODS

This was a retrospective review of 17,798 patients who underwent 20,324 unilateral primary TKAs between 2016 and 2020. Presence of pre-operative nickel allergy was determined (n=282). Patients were divided into 2 cohorts: those receiving (1) nickel-free or (2) CoCr implants. Clinical outcome scores and revision rates were assessed.

RESULTS

243 received a nickel-free implant and 39 received a CoCr implant. There was no significant difference in revision rate between the cohorts. Survivorship free of revision was 94% in the CoCr implant cohort and 98% in the nickel-free implant cohort (P=0.9). When comparing clinical outcome scores between cohorts, there was no difference in preoperative, 6-week or 1-year Knee Osteoarthritis Outcome Score Joint Replacement (KOOS JR.), Visual Analog Scale (VAS), Lower Extremity Activity Scale (LEAS), Patient-Reported Outcomes Measurement Information System (PROMIS), and Veterans RAND 12-item (VR12) scores between cohorts.

CONCLUSIONS

In this retrospective cohort study, there was no difference in revision rates or clinical outcomes in patients who had a nickel allergy undergoing primary TKA with CoCr or nickel-free implants. Further studies are needed to determine if nickel allergy is an independent risk factor for worse TKA outcomes in general.

Traumatic brain injury in college students and the influence of alcohol consumption: A retrospective review from a rural state

Objectives

There is a strong association between alcohol consumption and traumatic brain injury (TBI). Students are known to consume alcohol at a high rate. Despite the connection between alcohol and TBI, this is one of few studies to examine the connection between students, alcohol, and TBI. The objective of this study was to explore the relationship between students, alcohol, and TBI.

Materials and Methods

A retrospective chart review utilizing the institutional trauma data back was performed for patients 18-26 years of age, admitted to the emergency department with a diagnosis of a TBI and positive blood alcohol. Patient diagnosis, injury mechanism, alcohol level on admission, urine drug screen, mortality, injury severity score, and discharge disposition were recorded. The data were analyzed using Wilcoxon rank-sum tests and Chi-square tests to identify differences between students and non-student groups.

Results

Six hundred and thirty-six charts were reviewed for patients aged 18-26 with a positive blood alcohol level and TBI. The sample included 186 students, 209 non-students, and 241 uncertain of status. The student group had significantly higher levels of alcohol than the non-student group (P < 0.0001). P < 0.0001 showed that overall alcohol levels for males are significantly higher than levels of alcohol for females in the student group.

Conclusion

Alcohol consumption contributes to significant injuries such as TBI in college students. Male students had a higher prevalence of TBI, and higher alcohol levels than female students. These results can be used to inform and better target harm reduction and alcohol awareness programs.

Outcomes After Revision Total Knee Arthroplasty from a Specific, Now-recalled Implant System

BACKGROUND

A specific total knee arthroplasty (TKA) implant system was recently recalled for high incidence of early polymeric wear and osteolysis. We analyzed the early outcomes of aseptic revision with these implants.

METHODS

We identified 202 aseptic revision TKAs of this implant system performed at a single institution between 2010 and 2020. Revision indications included aseptic loosening (n=120), instability (n=55), and polymeric wear/osteolysis (n=27). In 145 cases (72%) components were revised and 57 cases (28%) were isolated polyethylene insert exchange. Kaplan-Meier and Cox proportional hazards analyses were used to determine survivorship free from all-cause re-revision and re-revision risk factors.

RESULTS

At 2 and 5 years, survivorship free from all-cause re-revision was 89 and 76% in the polyethylene exchange cohort versus 92 and 84% in the component revision cohort (P=0.5). At 2 and 5 years, survivorship in revision with components from the same manufacturer was 89 and 80% compared to 95 and 86% in revision with components from a different manufacturer (P=0.2). Among re-revisions (n=30), cones (37%), sleeves (7%), hinge/distal femoral replacement implants were frequently used (13%). Men had increased risk for re-revision (Hazard Ratio=2.3, P=0.04).

CONCLUSIONS

In this series of aseptic revision TKAs performed on a now-recalled implant system, survivorship free from re-revision was lower than expected when components from the same manufacturer were utilized, but comparable to contemporary reports when both components were revised with an alternative implant system. Metaphyseal fixation with cones and sleeves as well as highly constrained implants were frequently utilized at time of re-revision TKA.

Subacute sclerosing panencephalitis : CT and MR imaging in a rapidly progressive case

We report the findings on CT and MR imaging in a patient with rapidly progressive subacute sclerosing panencephalitis (SSPE), which correlated with the clinical progression of the disease. In view of the rapid neurological deterioration and CSF pleocytosis, a brain biopsy was done and this confirmed the diagnosis.

Effects of intranasal challenge with group A beta haemolytic streptococcus M type 49 in Swiss albino mice

Mice are susceptible to natural infections with streptococci and therefore can serve as suitable animal models to study experimental streptococcal infections. In an earlier study, we had shown the development of pharyngeal colonization, antibody response and histopathological changes in the heart following intranasal (IN) challenge with a rheumatogenic serotype of group A beta haemolytic streptococcus, the M type 18. To determine if nonpharyngitis associated serotypes can also elicit similar responses, 30 Swiss albino mice were challenged intranasally with 2 x 10(7) colony forming units of a skin associated serotype of group A beta haemolytic streptococcus, the M type 49. Pharyngeal colonization varied from 64% (n = 30) in the first week to 69% (n = 16) during the fourth week after IN challenge. Eleven (36.7%) of the 30 animals studied showed antibody response to DNase B (ADNB) with peak titers varying from 150 to 1200 units. Wide variations were seen in ADNB titers in individual mice. Histopathological evidence for cardiac lesions were seen in three animals. The changes were mild and varied from mild to chronic endocardial inflammation to calcification. The study shows that Swiss albino mice are also susceptible to IN challenge with skin associated strains of GABHS and therefore can serve as useful models to study the effects of experimental infection with diverse serotypes of GABHS.

Histological studies in primary neuritic leprosy: changes in the apparently normal skin

The visually normal skin of 196 patients diagnosed clinically to have primary neuritic leprosy was studied histologically to determine whether there were any specific changes due to the disease in this site. Histological changes due to leprosy were seen in 32.1% of the patients, and included, indeterminate leprosy in 19.4%, borderline tuberculoid leprosy in 6.6% and borderline lepromatous leprosy in 6.1%. The remaining biopsies showed mild non-specific dermal inflammation, mild nerve changes or no significant lesion. The nerve inflammation and/or granulomas were mostly in the deep dermal nerves or neurovascular complexes. This study shows that there is a cutaneous component to primary neuritic leprosy and the disease is not totally confined to nerves. The absence of visible hypopigmented patches in these patients is probably related to the deep location of the dermal inflammation.

Pharyngeal colonisation, ADNB response and development of cardiac lesions in mice following intranasal inoculation with group A beta haemolytic streptococcus M type 18

Swiss albino mice from a randomly bred colony were inoculated intranasally with 1.6, 2 or 2.4 x 10(7) colony forming units of a mid-logarithmic phase culture of group A beta haemolytic streptococcus M type 18 for 3 days, 6 days or once a week respectively for three weeks. Pharyngeal colonisation could be observed in 67 (59.8%) of 112 mice on 4th day after inoculation and 14 (38%) of the 37 mice on 21st day. Out of 27 mice tested for determination of antibodies to deoxyribonuclease B at regular intervals for 98 days, 15 (55.5%) showed responses, with maximum titers varying from 50 units to 4800 units in individual mice. Histopathological evidence for cardiac lesions were seen in five (3.03%) of the 165 animals studied. These included one case of severe endocarditis, two cases of endocarditis with valvular lesions and one case with non-specific lymphocyte infiltration in the heart. One other animal showed subendocardial oval nodular aggregates. Although the cellular nature of these lesions were not determined, this study shows that Swiss albino mice can serve as suitable animal models to study experimental streptococcal infections. However these are preliminary observations and are to be confirmed and revalidated by further controlled experiments.

Spinal cord edema, 5-hydroxytryptamine, lipid peroxidation, and lysosomal enzyme release after acute contusion and compression injury in primates

Physical and biochemical changes in the spinal cord of monkeys at 1/2, 2, and 4 hours following 200 g cm contusion injury and 50 g of compression injury and 2 hours of decompression following 4 hours of compression were studied. The pathophysiologic changes were milder in compression compared to contusion injury. Following contusion injury, at 1/2 and 2 hours there was significant increase in % water content, lipid peroxidation, and alpha-L-fucosidase. alpha-D-Mannosidase was significantly increased at all time periods, and beta-D-hexosaminidase was increased at 1/2 and 4 hours. At 4 hours following injury, serotonin (5 HT) and 5-hydroxyindole-3-acetic acid (5-HIAA) showed a significant increase. From 10 minutes to 2 hours there was increased platelet aggregation. In compression injury, a significant increase in water content and 5 HT was observed only at 1/2 hour. Lipid peroxidation had increased at all time periods, whereas B-D-hexosaminidase, beta-D-galactosidase, and 5-HIAA were increased at 2 hours. alpha-D-Mannosidase had increased at 1/2 and 2 hours, and alpha-L-fucosidase had increased at 4 hours. After 2 hours decompression following 4 hours compression, water content, beta-D-galactosidase, and alpha-D-Mannosidase were significantly increased. An attempt was made to correlate the findings and to understand the sequential pathophysiologic changes in the first 4 hours following spinal cord trauma, providing a baseline for evaluation of the efficacy of any therapeutic maneuvers.