Pain in desmoid-type fibromatosis: Prevalence,determinants and prognosis value

The aim of this study is to evaluate the prevalence, determinants and prognostic value of pain at diagnosis in patients with desmoid-type fibromatosis (DF). We selected patients from the ALTITUDES cohort (NCT02867033), managed by surgery, active surveillance or systemic treatments, with pain assessment at diagnosis. Patients were invited to fill QLQ-C30 questionnaire and Hospital Anxiety Depression Scale. Determinants were identified using logistic models. Prognostic value on event-free survival (EFS) was evaluated using the Cox model. Overall, 382 patients were included in the current study (median age: 40.2 years; 117 men). The prevalence of pain was 36%, without significant difference according to first-line treatment (P = .18). In the multivariate analysis, pain was significantly associated with tumor size >50 mm (P = .013) and tumor site (P < .001); pain was more frequent in the neck and shoulder locations (odds ratio: 3.05 [1.27-7.29]). Pain at baseline was significantly associated with poor quality of life (P < .001), depression (P = .02), lower performance status (P = .03) and functional impairment (P = .001); we also observed a nonsignificant association with anxiety (P = .10). In the univariate analysis, baseline pain was associated with poor EFS; the 3-year EFS was 54% in patients with pain compared to 72% in those without pain. After adjustment for sex, age, size and line of treatment, pain was still associated with poor EFS (hazard ratio: 1.82 [1.23-2.68], P = .003). One third of recently diagnosed patients with DF experienced pain, especially those with larger tumors and neck/shoulder locations. Pain was associated with unfavorable EFS after adjustment for the confounders.     

Kidney‐Induced Cardiac Allograft Tolerance in Miniature Swine is Dependent on MHC‐Matching of Donor Cardiac and Renal Parenchyma

Kidney allografts possess the ability to enable a short course of immunosuppression to induce tolerance of themselves and of cardiac allografts across a full‐MHC barrier in miniature swine. However, the renal element(s) responsible for kidney‐induced cardiac allograft tolerance (KICAT) are unknown. Here we investigated whether MHC disparities between parenchyma versus hematopoietic‐derived “passenger” cells of the heart and kidney allografts affected KICAT. Heart and kidney allografts were co‐transplanted into MHC‐mismatched recipients treated with high‐dose tacrolimus for 12 days. Group 1 animals (n = 3) received kidney and heart allografts fully MHC‐mismatched to each other and to the recipient. Group 2 animals (n = 3) received kidney and heart allografts MHC‐matched to each other but MHC‐mismatched to the recipient. Group 3 animals (n = 3) received chimeric kidney allografts whose parenchyma was MHC‐mismatched to the donor heart. Group 4 animals (n = 3) received chimeric kidney allografts whose passenger leukocytes were MHC‐mismatched to the donor heart. Five of six heart allografts in Groups 1 and 3 rejected <40 days. In contrast, heart allografts in Groups 2 and 4 survived >150 days without rejection (p < 0.05). These data demonstrate that KICAT requires MHC‐matching between kidney allograft parenchyma and heart allografts, suggesting that cells intrinsic to the kidney enable cardiac allograft tolerance.     

Does Cyclic Stress Play a Role in Highly Crosslinked Polyethylene Oxidation?

Background

Minimizing the impact of oxidation on ultrahigh-molecular-weight polyethylene components is important for preserving their mechanical integrity while in vivo. Among the strategies to reduce oxidation in modern first-generation highly crosslinked polyethylenes (HXLPEs), postirradiation remelting was considered to afford the greatest stability. However, recent studies have documented measurable oxidation in remelted HXLPE retrievals. Biologic prooxidants and physiologic loading have been proposed as potential mechanisms.

Questions/purposes

In our pilot study, we asked: (1) Does cyclic stress induced by wear or (2) by cyclic compression loading increase oxidation and crystallinity of remelted HXLPE? (3) Does oxidative aging reduce the wear resistance of remelted HXLPE?

Methods

Remelted and annealed HXLPE prisms (n = 1 per test condition) were tested in a wear simulator for 500,000 cycles. After wear testing, some samples were subjected to accelerated aging and then wear-tested again. Wear track volumes were characterized by confocal microscopy. Thin films (200-μm thick) were microtomed from wear prisms and then used for Fourier transform infrared spectroscopy oxidation and crystallinity assessments. Remelted HXLPE compression cylinders (n = 1 per test condition) were subjected to fatigue experiments and similar oxidation characterization.

Results

Remelted HXLPE qualitatively showed low oxidation indices (≤ 1) when subjected either to cyclic loading or aging alone. However, oxidation levels almost doubled in near-surface regions when remelted HXLPE samples underwent consecutive cyclic loading, artificial aging, and cyclic loading steps. The type of loading (wear versus compression fatigue) appeared to not affect the oxidation behavior in the studied conditions. Annealed HXLPE showed higher oxidation (oxidation index > 3) than remelted HXLPE and delamination wear. No delamination wear was observed in remelted HXLPE in agreement with its comparatively low oxidation levels (oxidation index < 3).

Conclusions

With the numbers available in our pilot study, the findings suggest that cyclic stress arising from a wear process or from cyclic compression may trigger the loss of oxidative stability of remelted HXLPE and contribute to synergistically accelerate its progression. Further studies of the effect of cyclic stress on oxidation of remelted HXLPE are needed.

Clinical Relevance

Retrieval studies are warranted to determine the natural history of the in vivo oxidation and wear behavior of first-generation, remelted HXLPE.     

Rare complications of osteolysis and periprosthetic tissue reactions after hybrid and non-hybrid total disc replacement

Purpose

Few complications have been reported for lumbar total disc replacement (TDR) and hybrid TDR fixations. This study evaluated retrieved implants and periprosthetic tissue reactions for two cases of osteolysis following disc arthroplasty with ProDisc-L prostheses.

Methods

Implants were examined for wear and surface damage, and tissues for inflammation, polyethylene wear debris (polarized light microscopy) and metal debris (energy-dispersive X-ray spectroscopy).

Results

Despite initial good surgical outcomes, osteolytic cysts were noted in both patients at vertebrae adjacent to the implants. For the hybrid TDR case, heterotopic ossification and tissue necrosis due to wear-induced inflammation were observed. In contrast, the non-hybrid implant showed signs of abrasion and impingement, and inflammation was observed in tissue regions with metal and polyethylene wear debris.

Conclusions

In both cases, wear debris and inflammation may have contributed to osteolysis. Surgeons using ProDisc prostheses should be aware of these rare complications.

     

UHMWPE Wear Debris and Tissue Reactions Are Reduced for Contemporary Designs of Lumbar Total Disc Replacements

Background

Lumbar total disc replacement (L-TDR) is a procedure used to relieve back pain and maintain mobility. Contemporary metal-on-polyethylene (MoP) L-TDRs were developed to address wear performance concerns about historical designs, but wear debris generation and periprosthetic tissue reactions for these newer implants have not been determined.

Questions/purposes

The purpose of this study was to determine (1) whether periprosthetic ultrahigh-molecular-weight polyethylene (UHMWPE) wear debris and biological responses were present in tissues from revised contemporary MoP L-TDRs that contain conventional cores fabricated from γ-inert-sterilized UHMWPE; (2) how fixed- versus mobile-bearing design affected UHMWPE wear particle number, shape, and size; and (3) how these wear particle characteristics compare with historical MoP L-TDRs that contain cores fabricated from γ-air-sterilized UHMWPE.

Methods

We evaluated periprosthetic tissues from 11 patients who received eight fixed-bearing ProDisc-L and four mobile-bearing CHARITÉ contemporary L-TDRs with a mean implantation time of 4.1 and 2.7 years, respectively. Histologic analysis of tissues was performed to assess biological responses and polarized light microscopy was used to quantify number and size/shape characteristics of UHMWPE wear particles from the fixed- and mobile-bearing devices. Comparisons were made to previously reported particle data for historical L-TDRs.

Results

Five of seven (71%) fixed-bearing and one of four mobile-bearing L-TDR patient tissues contained at least 4 particles/mm² wear with associated macrophage infiltration. Tissues with wear debris were highly vascularized, whereas those without debris were more necrotic. Given the samples available, the tissue around mobile-bearing L-TDR was observed to contain 87% more, 11% rounder, and 11% less-elongated wear debris compared with tissues around fixed-bearing devices; however, there were no significant differences. Compared with historical L-TDRs, UHMWPE particle number and circularity for contemporary L-TDRs were 99% less (p = 0.003) and 50% rounder (p = 0.003).

Conclusions

In this preliminary study, short-term results suggest there was no significant influence of fixed- or mobile-bearing designs on wear particle characteristics of contemporary L-TDRs, but conventional UHMWPE has notably improved the wear resistance of these devices compared with historical UHMWPE.     

Multi-unit fixed partial denture for a bilateral cleft palate patient: a clinical report

Patients with cleft palates eventually require definitive fixed or removable dental prostheses after the maintenance of arch alignment and occlusal relationship during adolescence. This case report presents application of a resin composite veneered fixed partial denture utilized as a definitive prosthesis for a bilateral cleft palate patient after stable occlusion had been established orthodontically. The composite veneered long span fixed partial denture provides adequate aesthetics and function.     

Evaluation of transitional implant stabilized overdentures: a case series report

Transitional implants (TI) can immediately improve the stability and retention of existing unstable mandibular complete dentures. This study evaluated the improvement of mandibular complete denture stability and retention with the use of TI. Three TIs were placed in the intraforaminal region of the edentulous mandible of seven patients (three men, four women; mean age 69.7 years). The patients' existing mandibular complete dentures were immediately modified to TI-stabilized overdentures. Their masticatory movements (mandibular movements during mastication) were measured using a commercially available tracking device (BioPACK, Bioresearch, Japan), both before TI placement and about 1 month after delivery of the TI-stabilized overdentures. The mean time of each chewing phase (opening, closing, and occluding) and coefficients of variation were calculated. The patients also completed a questionnaire about the foods they could chew and indicated on a 100 mm Visual Analog Scale (VAS) their personal levels of comfort, ease of chewing, speech, and stability. For masticatory movements, there were no significant differences (P > 0.05) between the TI-stabilized overdentures and existing complete dentures. However, the number of foods that could be chewed increased, and the stability and comfort were reported as improved with the TI-stabilized overdentures. Using TIs, the stability and comfort of the existing mandibular complete dentures studied in this report could be immediately improved.