Proximal Interphalangeal Joint Silicone Arthroplasty for Osteoarthritis: Midterm Outcomes.

Background: Osteoarthritis of the proximal interphalangeal (PIP) joint affects a large percentage of the population and can lead to significant functional disability. The purpose of this study is to evaluate the midterm clinical effectiveness of PIP joint arthroplasty for nonrheumatic arthritis. Methods: A single-center retrospective cohort study evaluating preoperative and postoperative objective and subjective measures was conducted. Range of motion (ROM), Disabilities of the Arm, Shoulder and Hand scores, key pinch strength, grip strength, and satisfaction with respect to pain, deformity, function, and strength were measured. Results: Forty-five fingers in 25 patients were followed up for a mean period of 42 months. Preoperative and postoperative mean ROM was equivalent at 59.1° and 59.2°, respectively. Postoperative grip and key pinch strength showed significant improvement and near normalization compared with contralateral extremity. Complication rate was 37% with 20% requiring revision surgery. Patients with diabetes mellitus had higher odds of requiring revision surgery. Pain scores improved from 7.4 to 1.9 on a visual analog scale. Overall satisfaction was high at 84%, and 91% of patients would have the surgery performed again. Conclusions: Silicone arthroplasty for osteoarthritis of the PIP remains a good option for pain relief. Our study presents midterm follow-up data that support significant pain relief, increased grip and key pinch strength, and high satisfaction associated with this implant.

Flow-dependent expression of ectonucleotide tri(di)phosphohydrolase-1 and suppression of atherosclerosis.

The ability of cells to detect and respond to nucleotide signals in the local microenvironment is essential for vascular homeostasis. The enzyme ectonucleotide tri(di)phosphohydrolase-1 (ENTPD1, also known as CD39) on the surface of leukocytes and endothelial cells metabolizes locally released, intravascular ATP and ADP, thereby eliminating these prothrombotic and proinflammatory stimuli. Here, we evaluated the contribution of CD39 to atherogenesis in the apolipoprotein E-deficient (ApoE-deficient) mouse model of atherosclerosis. Compared with control ApoE-deficient animals, plaque burden was markedly increased along with circulating markers of platelet activation in Cd39+/-Apoe-/- mice fed a high-fat diet. Plaque analysis revealed stark regionalization of endothelial CD39 expression and function in Apoe-/- mice, with CD39 prominently expressed in atheroprotective, stable flow regions and diminished in atheroprone areas subject to disturbed flow. In mice, disturbed flow as the result of partial carotid artery ligation rapidly suppressed endothelial CD39 expression. Moreover, unidirectional laminar shear stress induced atheroprotective CD39 expression in human endothelial cells. CD39 induction was dependent upon the vascular transcription factor Krüppel-like factor 2 (KLF2) binding near the transcriptional start site of CD39. Together, these data establish CD39 as a regionalized regulator of atherogenesis that is driven by shear stress.

Silicone arthroplasty for nonrheumatic metacarpophalangeal joint arthritis.

PURPOSE: To evaluate the clinical effectiveness of metacarpophalangeal (MCP) arthroplasty for nonrheumatic arthritis. We hypothesized that MCP arthroplasty would produce significant improvement in objective measures of hand function, pain relief, and overall patient satisfaction. METHODS: This retrospective study evaluated 30 patients with 38 MCP arthroplasties for nonrheumatic arthritis over a 12-year period. Follow-up assessment was completed at an average of 56 months after surgery. Objective measures included range of motion; grip and pinch strength; Disabilities of the Arm, Shoulder, and Hand (DASH) score; and visual analog pain score. A subjective patient questionnaire was used to assess patient satisfaction. RESULTS: There was marked improvement between preoperative and follow-up range of motion, DASH, and pain. Linear regression showed strong correlations between preoperative measurements and improvement at follow-up. No difference was detected for grip or pinch strength. Results of the questionnaire showed that 73% were very satisfied, 87% would definitely do it again, and 70% experienced rare or no pain. Follow-up x-rays showed 5° mean angulation and 2-mm mean subsidence compared with immediate postoperative x-rays. Four arthroplasties (11%) required revision. CONCLUSIONS: This study showed improved range of motion and DASH score, excellent pain relief, and excellent patient satisfaction in patients undergoing MCP arthroplasty for nonrheumatic arthritis. Patients with more severe range of motion limitation, DASH score, and pain score experienced a greater improvement of these measures at follow-up. Strength improvement was limited although it remained comparable to the nonoperated hand. Angulation, subsidence, and complications in the study population were consistent with those reported in the literature. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.