Foraminal Restenosis After Posterior Cervical Foraminotomy for the Treatment of Cervical Radiculopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To elucidate incidence, risk factor, and clinical effect of bone regrowth after posterior cervical foraminotomy (PCF). METHODS: Ninety-eight patients who underwent PCF for the treatment of cervical radiculopathy and were followed up for >2 years were retrospectively reviewed. Foraminal dimension, sagittal gap at resected area, facet thickness, lamina length, and cervical range of motion (ROM) were measured. Neck pain visual analogue scale (VAS), arm pain VAS, and neck disability index (NDI) were recorded. Radiographic measures were compared between segments with foraminal narrowing of ≥20% at the 2-years follow-up (restenosis segments) and foraminal narrowing of <20% (patent segments). RESULTS: Sixty-nine patients with 109 segments were included. 73.4% (80/109) of foramens demonstrated foraminal narrowing and decrease of foraminal dimension of ≥20% occurred in 30.3% (30/109). Foraminal dimension at postoperative 2-days was significantly higher in the restenosis segments (P = .047). Furthermore, increase of foraminal dimension was significantly associated with foraminal restenosis of ≥20% (P = .018). Facet thickness was significantly higher in the restenosis segments compared to patent segments at postoperative 2-years follow-up (P = .038). Neck pain VAS was significantly aggravated only in the restenosis group at postoperative 2-years follow-up (P < .001). CONCLUSIONS: Foraminal narrowing commonly occurs after PCF due to bone healing. Bone growth occurs in all directions while medial facet growth contributes more to foraminal restenosis. Greater widening of foramen during PCF is a risk factor for postoperative foramen restenosis. Therefore, amount of bone resection should be kept optimal and excessive resection should be avoided to prevent foramen restenosis.

Interleukin-4 enzyme-linked immunospot assay may be useful for diagnosing sensitization to house dust mite.

BACKGROUND: The skin prick test (SPT) is considered a standard test for identification of allergens, but it has some limitations in clinical practice. The multiple allergen simultaneous test (MAST), which measures allergen-specific immunoglobulin E in patients' serum, is a widely used alternative test, but is limited by its relatively low sensitivity and specificity. As a novel diagnostic test to identify allergens, we investigated the sensitivity and specificity of an interleukin-4 (IL-4) enzyme-linked immunospot (ELISpot) assay for Dermatophagoides farinae (Der f) and Dermatophagoides pteronyssinus (Der p). METHODS: Based on the symptoms and SPT results, 43 house dust mite (HDM) allergic rhinitis (AR) patients and 41 control subjects were included. Peripheral blood was drawn from each subject for IL-4 ELISpot assay and MAST. The receiver operating characteristic (ROC) curve analysis was conducted to determine the cutoff values. Sensitivity, specificity, and positive and neg predictive values were compared between the 2 tests. RESULTS: The sensitivity, specificity, and areas under the ROC curve (AUCs) of the IL-4 ELISpot assay were 88.4%, 97.6%, and 0.939 for Der f, and 95.3%, 97.5%, and 0.971 for Der p, respectively. However, the sensitivity, specificity, and AUC of MAST were 76.7%, 73.2%, and 0.777 for Der f, and 69.8%, 75.6%, and 0.788 for Der p, respectively. CONCLUSION: The IL-4 ELISpot assay showed higher sensitivity, specificity, and AUC than MAST, which indicates its clinical feasibility for diagnosing allergy for HDM. A further study is needed to determine the accuracy of the IL-4 ELISpot assay for other common allergens.

Factors affecting the osteolysis around the components after posterior-stabilized total knee replacement arthroplasty.

PURPOSE: The purpose of the present study was to evaluate factors that affect the occurrence of osteolysis through clinical and radiological comparison between a patient group in which osteolysis occurred after total knee arthroplasty (TKA) and a patient group in which osteolysis did not occur after TKA. METHODS: The present study was conducted with 486 knees that had been followed up for at least 2 years after undergoing a posterior-stabilized TKA. The subjects were divided into a group in which osteolysis occurred and a group in which osteolysis did not occur and retrospectively compared and analyzed. Knee Society Knee Score and Function Score, preoperative and postoperative range of motion (ROM), femoral and tibial implant positions, preoperative and postoperative femerotibial angles, posterior femoral condylar offset (PCO), level of joint line (JL), and posterior tibial slopes were measured and clinically and radiologically compared. RESULTS: Osteolysis occurred in 28 knee joints (5.7%). No significant difference was observed between the patient group without osteolysis, and the patient group with osteolysis was observed in preoperative and postoperative ROM, femoral and tibial implant positions, or preoperative and postoperative femerotibial angles. The means of preoperative and postoperative differences in PCO and level of JL were significantly larger in the patient group with osteolysis than in the patient group without osteolysis (p = 0.01, p = 0.007), and regression analyses showed that the means of preoperative and postoperative differences in these two variables were related with the occurrence of osteolysis (p = 0.021, p = 0.018). CONCLUSION: The present study shows that biomechanical changes occurring after TKA are related with the occurrence of osteolysis. For clinical relevance, surgeons should pay great attention to restore normal anatomical structure as much as possible with careful preoperative plans, accurate surgical techniques, and selection of appropriate implants. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.