Association with Systemic and Ophthalmic Disease in Korean Pseudoexfoliation Syndrome Patients

Purpose@#To analyze the association of systemic and ophthalmic disease in patients with pseudoexfoliation syndrome. @*Methods@#We retrospectively reviewed the records of 207 patients with pseudoexfoliation syndrome and 201 age-matched controls without pseudoexfoliation syndrome seen from January 2016 to January 2021. Age, sex, systemic diseases such as diabetes mellitus, hypertension, cardiovascular and cerebrovascular disease, and ocular disease including retinal vascular occlusion, age-related macular degeneration (AMD), glaucoma, cataract surgery rate, complications related to cataract surgery, and ocular characteristics were compared. Factors associated with pseudoexfoliation syndrome were analyzed using logistic regression. @*Results@#The frequencies of diabetes mellitus, hypertension, AMD, glaucoma, a history of cataract surgery, and complications related to cataract surgery were significantly higher in patients with pseudoexfoliation syndrome (all Ps ≤ 0.049). The pseudoexfoliation syndrome group had a significantly thinner global retinal nerve fiber layer, worse mean deviation and pattern standard deviation, and smaller dilated pupil size than the controls (all Ps < 0.001). In univariate and multivariate logistic regressions, the presence of diabetes mellitus (odds ratio [OR] = 1.613, p = 0.041), AMD (OR = 3.071, p = 0.001), and glaucoma (OR = 17.800, p < 0.001) were associated with pseudoexfoliation syndrome. @*Conclusions@#Diabetes mellitus, hypertension, AMD, and glaucoma were more frequent in pseudoexfoliation syndrome patients. Since pseudoexfoliation syndrome is closely related to AMD and glaucoma, this requires clinical consideration.

Hip Fracture Surgery without Transfusion in Patients with Hemoglobin Less Than 10 g/dL

Background@#Hip fracture surgery is associated with blood loss, which may lead to adverse patient outcomes. The hemoglobin level declines gradually in most hip fracture cases involving femoral neck fractures and intertrochanteric fractures. It decreases further after hip fracture surgery due to perioperative bleeding. We developed a protocol, which avoids transfusion in hip fracture surgery, and reviewed the hemodynamic outcomes of patients with hemoglobin less than 10 g/dL without transfusion. @*Methods@#From 2014 to 2019, we retrospectively recruited 34 patients with hip fractures and a hemoglobin level less than 10 g/dL, who refused to undergo transfusion. There were 19 patients with femoral neck fractures and 15 patients with intertrochanteric fractures. Our patient blood management (PBM) protocol involving 4,000 U erythropoietin (3 times a week) and 100 mg iron supplement (every day) was applied to all included patients. Intraoperatively, a cell saver and tranexamic acid were used. Postoperatively, the protocol was maintained until the patients’ hemoglobin level reached 10 g/dL. We evaluated the feasibility of our protocol, perioperative complications, and hemodynamic changes. @*Results@#Nineteen patients with femoral neck fractures underwent bipolar hemiarthroplasty and 15 patients with intertrochanteric frac tures underwent internal fixation with a cephalomedullary nail. The mean hemoglobin level was 8.9 g/dL (range, 7.3–9.9 g/dL) pre operatively, 7.9 g/dL (range, 6.5–9.3 g/dL) immediately postoperatively, 7.7 g/dL (range, 4.3–9.5 g/dL) on postoperative day 1, 7.4 g/dL (range, 4.2–9.4 g/dL) on postoperative day 3, 8.1 g/dL (range, 4.4–9.7 g/dL) on postoperative day 5, 8.5 g/dL (range, 4.5–9.9 g/dL) on post­operative day 7, and 9.9 g/dL (range, 5.7–11.1 g/dL) on postoperative day 14. The average intraoperative bleeding was 206.2 ± 78.7 mL. There was no case associated with complications of anemia. @*Conclusions@#Hip fracture surgery in patients with hemoglobin less than 10 g/dL was feasible without the need for transfusion using our PBM protocol in 34 patients. Using this protocol, the operation was conducted safely despite the anemic condition of patients with fractures whose hemoglobin was less than 10 g/dL.

Ocular Pain According to Needle Diameter during Intravitreal Injection

Purpose@#To compare the ocular pain scores and injection times of patients during 30 and 40-gauge intravitreal injection procedures. @*Methods@#This study was performed prospectively in patients who had not previously received intravitreal injection. Patients were randomly divided into two groups and intravitreal injections of bevacizumab, ranibizumab, and aflibercept were performed using a 30-gauge needle (30G Group) or a 40-gauge needle (40G group). The injection time defined as the time between conjunctival touching of the needle and finishing the hemostasis after needle removal was measured in each patient. Immediately after the injection, patients were asked to rate their pain level during the injection using a visual analogue scale (0, no pain; 10, unbearable pain). @*Results@#Sixty eyes of 60 patients were included in this study and 30 patients were assigned to each group. The mean injection times of the 30G and 40G groups were 42.00 ± 37.18 and 32.73 ± 14.58 seconds, respectively, with no significant difference (p = 0.212). The visual analogue scale, pain scores in the 30G and 40G groups were 3.50 ± 1.25 and 2.87 ± 1.01, respectively, with a significant difference (p = 0.035). @*Conclusions@#Intravitreal injection with a 40-gauge needle was less painful than that with a 30-gauge needle.

Deletion Timing of Cic Alleles during Hematopoiesis Determines the Degree of Peripheral CD4+ T Cell Activation and Proliferation

Capicua (CIC) is a transcriptional repressor that regulates several developmental processes. CIC deficiency results in lymphoproliferative autoimmunity accompanied by expansion of CD44hiCD62Llo effector/memory and follicular Th cell populations. Deletion of Cic alleles in hematopoietic stem cells (Vav1-Cre-mediated knockout of Cic) causes more severe autoimmunity than that caused by the knockout of Cic in CD4+CD8+ double positive thymocytes (Cd4-Cre-mediated knockout of Cic). In this study, we compared splenic CD4+ T cell activation and proliferation between whole immune cell-specific Cic-null (Cicf/f;Vav1-Cre) and T cell-specific Cic-null (Cicf/f;Cd4-Cre) mice. Hyperactivation and hyperproliferation of CD4+ T cells were more apparent in Cicf/f;Vav1-Cre mice than in Cicf/f;Cd4-Cre mice. Cicf/f;Vav1-Cre CD4+ T cells more rapidly proliferated and secreted larger amounts of IL-2 upon TCR stimulation than did Cicf/f;Cd4-Cre CD4+ T cells, while the TCR stimulation-induced activation of the TCR signaling cascade and calcium flux were comparable between them. Mixed wild-type and Cicf/f;Vav1-Cre bone marrow chimeras also exhibited more apparent hyperactivation and hyperproliferation of Cic-deficient CD4+ T cells than did mixed wild-type and Cicf/f;Cd4-Cre bone marrow chimeras. Taken together, our data demonstrate that CIC deficiency at the beginning of T cell development endows peripheral CD4+ T cells with enhanced T cell activation and proliferative capability.

Deletion Timing of Cic Alleles during Hematopoiesis Determines the Degree of Peripheral CD4+ T Cell Activation and Proliferation

Capicua (CIC) is a transcriptional repressor that regulates several developmental processes. CIC deficiency results in lymphoproliferative autoimmunity accompanied by expansion of CD44hiCD62Llo effector/memory and follicular Th cell populations. Deletion of Cic alleles in hematopoietic stem cells (Vav1-Cre-mediated knockout of Cic) causes more severe autoimmunity than that caused by the knockout of Cic in CD4+CD8+ double positive thymocytes (Cd4-Cre-mediated knockout of Cic). In this study, we compared splenic CD4+ T cell activation and proliferation between whole immune cell-specific Cic-null (Cicf/f;Vav1-Cre) and T cell-specific Cic-null (Cicf/f;Cd4-Cre) mice. Hyperactivation and hyperproliferation of CD4+ T cells were more apparent in Cicf/f;Vav1-Cre mice than in Cicf/f;Cd4-Cre mice. Cicf/f;Vav1-Cre CD4+ T cells more rapidly proliferated and secreted larger amounts of IL-2 upon TCR stimulation than did Cicf/f;Cd4-Cre CD4+ T cells, while the TCR stimulation-induced activation of the TCR signaling cascade and calcium flux were comparable between them. Mixed wild-type and Cicf/f;Vav1-Cre bone marrow chimeras also exhibited more apparent hyperactivation and hyperproliferation of Cic-deficient CD4+ T cells than did mixed wild-type and Cicf/f;Cd4-Cre bone marrow chimeras. Taken together, our data demonstrate that CIC deficiency at the beginning of T cell development endows peripheral CD4+ T cells with enhanced T cell activation and proliferative capability.

Clinical Analysis of Newly Diagnosed Diabetes Mellitus Patients by Abnormal Fundus Examination

PURPOSE: To investigate the clinical analysis of newly diagnosed diabetes mellitus (NDM) patients with abnormal fundus examination at the first visit. METHODS: This retrospective study utilized the first visit medical records of 15 patients (30 eyes) who were diagnosed with NDM from February 2011 to October 2016. RESULTS: Patients were divided into 3 groups: 1) diabetic retinopathy group including proliferative diabetic retinopathy (PDR) (3) and severe non-proliferative diabetic retinopathy (NPDR) (1); 2) retinal vascular disease group including central retinal vein occlusion (CRVO) (1), branch retinal vein occlusion (1), vitreous hemorrhage with CRVO (1) and macular edema (1); and 3) other retinal disease group including vitreous hemorrhage due to choroidal neovascular rupture (1), exudative age-related macular degeneration (3), central serous chorioretinopathy (2), and macular hole (1). All 3 PDR patients had latent autoimmune diabetes in adults (type 1.5 diabetes). The remaining 12 patients had type 2 diabetes. Three patients showed mild NPDR in the opposite eye and the other 9 patients did not have diabetic retinopathy in the opposite eye. Onset age, HbA1C and proteinuria were significantly different between the diabetic retinopathy group and the other retinal disease group (p = 0.006, p = 0.012 and p = 0.006, Mann-Whitney test). CONCLUSIONS: In patients with various retinal diseases, early detection of NDM could be achieved by performing fundoscopic imaging and systemic examination as well as basic ophthalmologic examination. In addition, patients with diabetic retinopathy should be treated promptly through ophthalmology and internal medicine consultation. For the retinal vascular disease and other retinal disease groups, not only treatment for ophthalmic diseases, but also education about diabetes treatment are important.

External Snapping Hip Treated by Effective Designed N-plasty of the Iliotibial Band / 대한고관절학회지

PURPOSE: The purpose of this study is to present the effective design of N-plasty of the iliotibial band and surgical results of its use as a treatment for refractory external snapping hip. MATERIALS AND METHODS: We evaluated 17 patients (24 cases) with external snapping hip who underwent N-plasty between October 2013 and May 2016 and who were followed up for at least 12 months. All patients were male and the mean age was 20.8 years. The mean duration of symptoms prior to surgical intervention was 28.5 months with an average follow up of 24.5 months. Surgery was defined as being successful when patients could carry out their daily activities and exercise without a clicking sensation or pain 6 months after surgery until their last follow-up. Failure was defined when either a clicking sensation or pain was present. The visual analog scale (VAS) and modified Harris hip score (mHHS) were measured and compared preoperatively and at last follow-up. RESULTS: All patients had complete resolution of pain and snapping. The VAS decreased from 6.77 preoperatively to 0.09 postoperatively and mHHS improved from 69.5 to 97.8 after surgery. CONCLUSION: Modified designed N-plasty is considered to be an excellent treatment method facilitating operation reproducibility with maximum elongation effect of the iliotibial band.

External Snapping Hip Treated by Effective Designed N-plasty of the Iliotibial Band / 대한고관절학회지

PURPOSE: The purpose of this study is to present the effective design of N-plasty of the iliotibial band and surgical results of its use as a treatment for refractory external snapping hip. MATERIALS AND METHODS: We evaluated 17 patients (24 cases) with external snapping hip who underwent N-plasty between October 2013 and May 2016 and who were followed up for at least 12 months. All patients were male and the mean age was 20.8 years. The mean duration of symptoms prior to surgical intervention was 28.5 months with an average follow up of 24.5 months. Surgery was defined as being successful when patients could carry out their daily activities and exercise without a clicking sensation or pain 6 months after surgery until their last follow-up. Failure was defined when either a clicking sensation or pain was present. The visual analog scale (VAS) and modified Harris hip score (mHHS) were measured and compared preoperatively and at last follow-up. RESULTS: All patients had complete resolution of pain and snapping. The VAS decreased from 6.77 preoperatively to 0.09 postoperatively and mHHS improved from 69.5 to 97.8 after surgery. CONCLUSION: Modified designed N-plasty is considered to be an excellent treatment method facilitating operation reproducibility with maximum elongation effect of the iliotibial band.

A Case of SmartPlug Partial Extrusion through Canalicular Mucosa

PURPOSE: To report a case of a SmartPlug that partially extruded through the canalicular mucosa. CASE SUMMARY: A 62-year-old female patient visited our Department of Ophthalmology for redness and discharge in her right eye that began worsening a week prior. The patient was diagnosed with severe dry eye syndrome via Sjogren's syndrome. The SmartPlug was inserted into her left lower punctum 12 years prior, and another plug was inserted in the right 9 years prior. Nothing notable was found in her history. The best corrected visual acuity and intraocular pressure at the initial visit was 1.0 and 14 mmHg, respectively, in both eyes. Swelling, erythema, and tenderness at the right lower punctum were identified. As we irrigated the lower lacrimal system, partial obstruction was suspected and a large amount of mucopurulent discharge in the conjunctival fornix with conjunctival injection was seen. Under the right lower punctum, a 1 × 1 mm yellowish foreign body was partially extruding from the canalicular mucosa. The foreign body was removed, and a round defect was left. The patient's symptom completely resolved after 4 weeks of topical antibiotics and ointment treatment. CONCLUSIONS: In patients who have a SmartPlug inserted prior to visits for redness and discharge, a SmartPlug plug extrusion should be considered.

Revision Arthroplasty Using a MUTARS® Prosthesis in Comminuted Periprosthetic Fracture of the Distal Femur

Periprosthetic fractures after total knee arthroplasty (TKA) are gradually increasing, reflecting extended lifespan, osteoporosis, and the increasing proportion of the elderly during the past decade. Supracondylar periprosthetic femoral fracture is a potential complication after TKA. Generally, open reduction and internal fixation are the conventional option for periprosthetic fracture after TKA. However, the presence of severe comminution with component loosening can cause failure of internal fixation. Although the current concept for periprosthetic fracture is open reduction and internal fixation, we introduce an unusual case of revision arthroplasty using a MUTARS® prosthesis for a comminuted periprosthetic fracture in the distal femur after TKA, with technical tips.

Revision Arthroplasty Using a MUTARS® Prosthesis in Comminuted Periprosthetic Fracture of the Distal Femur

Periprosthetic fractures after total knee arthroplasty (TKA) are gradually increasing, reflecting extended lifespan, osteoporosis, and the increasing proportion of the elderly during the past decade. Supracondylar periprosthetic femoral fracture is a potential complication after TKA. Generally, open reduction and internal fixation are the conventional option for periprosthetic fracture after TKA. However, the presence of severe comminution with component loosening can cause failure of internal fixation. Although the current concept for periprosthetic fracture is open reduction and internal fixation, we introduce an unusual case of revision arthroplasty using a MUTARS® prosthesis for a comminuted periprosthetic fracture in the distal femur after TKA, with technical tips.

Clinical Results after Phacoemulsification in Mature Cataract

PURPOSE: To evaluate the clinical results after phacoemulsification in mature and immature cataracts. METHODS: Mature cataract was defined as a classification of C5 by Lens Opacities Classification System III compared with other types of cataracts as controls. The present study included 37 (37 eyes) patients diagnosed with mature cataracts that received phacoemulsification and were followed up for at least 1 year. Thirty-seven (37 eyes) patients with other types of cataracts were selected randomly as controls. Intraoperative factors and rate of complications during and after surgery were evaluated. Best corrected visual acuity (BCVA), corneal endothelial cell density and central macular thickness (CMT) were measured during the 1 year of follow-up and compared with the controls. RESULTS: Twenty-seven eyes (mature cataracts) and 36 eyes (controls) received a complete continuous curvilinear capsulorhexis (CCC). The success rate of complete CCC was significantly high in the control eyes (p = 0.025). However, in mature cataract patients, 3 cases of posterior capsule rupture occurred among the 6 cases of radial tear of the anterior capsule, resulting in implantation of the lens in the sulcus. Posterior capsular ruptures were observed in 4 patients with mature cataracts and in 1 control with no statistically significant difference in the occurrence rate. Total phacoemulsification time and effective phacoemulsification time were significantly longer in the mature cataract patients (p = 0.038 and p = 0.041, respectively). BCVA, the amount of corneal endothelial cell density reduction and CMT at postoperative 1 year was not different between the two groups. CONCLUSIONS: The success of complete CCC was a significant factor for the occurrence of intraoperative complications in mature cataract surgery. Based on the clinical results, the mature cataract patients and controls had a similar visual prognosis.

Long-Term Follow-Up of Adverse Consequences after Nd:YAG Laser Treatment for Posterior Capsular Opacification

PURPOSE: To evaluate the long-term follow-up of adverse effects after neodymium: yttrium-aluminum-garne (Nd:YAG) laser treatment for posterior capsular opacification (PCO). METHODS: In this study, 152 patients (184 eyes) diagnosed with PCO and who received Nd:YAG laser posterior capsulotomy with at least 5 years of follow-up were retrospectively analyzed to evaluate the clinical adverse consequences after Nd:YAG laser posterior capsulotomy. RESULTS: The mean age in the study group was 63.2 +/- 4.2 years and the mean follow-up period was 6.2 +/- 0.6 years. Vitreous floaters (8.1%) were the most common complication followed by reactive anterior uveitis (5.9%) and transient increase in intraocular pressure of more than 30 mm Hg (5.4%). Other complications included primary Nd:YAG laser failure (2.7%), recurrent lens epithelial remnant proliferation (1.6%), cystoid macular edema (1.1%), corneal edema (0.5%), retinal tear (0.5%), and rhegmatogenous retinal detachment (0.5%). CONCLUSIONS: Although Nd:YAG laser treatment is the most effective and safe method, surgeons should be aware of the occasional complications such as recurrent lens epithelial remnant proliferation, retinal tear, and rhegmatogenous retinal detachment through long-term follow-up.

Sciatic Nerve Palsy Caused by Ruptured and Contracted Short External Rotator Muscles after Primary Total Hip Arthroplasty / 대한고관절학회지

Although the incidence of sciatic nerve palsy following total hip arthroplasty is low, this complication can cause devastating permanent nerve palsy. The authors experienced a case of sciatic nerve palsy caused by ruptured and contracted external rotator muscles following total hip arthroplasty in a patient suffering from osteonecrosis of the femoral head. We report this unusual case of sciatic nerve palsy with a review of the literature.

Clinical and Radiologic Outcomes among Bipolar Hemiarthroplasty, Compression Hip Screw and Proximal Femur Nail Antirotation in Treating Comminuted Intertrochanteric Fractures / 대한고관절학회지

PURPOSE: In comminuted intertrochanteric fractures, various operative options have been introduced. The purpose of this study was to determine whether there were differences in clinical and radiologic outcomes among bipolar hemiarthroplasty (BH), compression hip screw (CHS) and proximal femur nail antirotation (PFNA) in treating comminuted intertrochanteric fractures (AO/OTA classification, A2 [22, 23]) MATERIALS AND METHODS: We retrospectively evaluated total 150 patients (BH, 50; CHS, 50; PFNA, 50) who were operated due to intertrochanteric fractures from March 2010 to December 2012 and were older than 65 years at the time of surgery. We compared these three groups for radiologic and clinical outcomes at 12 months postoperatively, including Harris Hip Score, mobility (Koval stage), visual analogue scale and radiologic limb length discrepancy (shortening). RESULTS: There was no statistical significance among three groups in clinical outcomes including Harris Hip Score, mobility (Koval stage), visual analogue scale. However, there was significant differences in radiologic limb discrepancy in plain radiographs at 12 months postoperatively (radiologic shortening: BH, 2.3 mm; CHS, 5.1 mm; PFNA, 3.0 mm; P=0.000). CONCLUSION: There were no clinical differences among BH, PFNA, and CHS in this study. However, notable limb length shortening could be originated during fracture healing in osteosynthesis, compared to arthroplasty (BH

Coccygectomy for Treatment of Coccygodynia / 대한정형외과학회잡지

PURPOSE: Coccygodynia is a painful condition localized in the region of the coccyx. Most cases of coccygodynia are treated conservatively. However, we conducted an analysis of patients who underwent coccygectomy, with chronic intractable coccygodynia and assessed the results of their treatment. MATERIALS AND METHODS: From March 2003 to August 2013, this study was conducted in order to investigate the benefit of coccygectomy in cases where conservative treatment has failed. We compared preoperative and postoperative visual analog scales (VAS) scores and confirmed duration of symptom free, complications. RESULTS: The average duration of symptom free was 3.4 months, and VAS score improved from 7.3 to 1.6. There was one wound infection. CONCLUSION: We can obtain satisfactory results through coccygectomy for chronic intractable coccygodynia.

Granular Cell Tumor in the Sartorius Muscle / 대한정형외과학회잡지

Granular cell tumor, a soft tissue neoplasm that originates in the nervous system, is a very unusual tumor. Granular cell tumor appears as a solitary painless lesion, which can arise at virtually any body site, but is mainly found on the skin, oral cavity, respiratory tract or digestive tract. However, an intramuscular granular cell tumor is very rare. We report on a case of a granular cell tumor in the sartorius muscle in a 71-year-old male patient along with a review of the literature.

Outcomes of Vitrectomy for Severe Vitreous Hemorrhage of Unknown Etiology

PURPOSE: To analyze the clinical course and outcomes of vitrectomy for severe vitreous hemorrhage of unknown etiology and to determine the primary cause of hemorrhage during the surgical process. METHODS: The medical records of patients who showed vitreous hemorrhage of Grade IV at their initial visit with no remarkable ophthalmologic or trauma history were reviewed retrospectively. All included patients underwent vitrectomy for severe vitreous hemorrhage for which a primary cause was not revealed before the surgery. The authors investigated the postoperative visual outcome, complications, and etiology of vitreous hemorrhage that was determined during the surgical process. We also analyzed the detailed intraoperative and postoperative funduscopic findings of patients with poor postoperative visual outcomes (BCVA < 20/200). RESULTS: Among the 50 eyes of 50 patients, the causes of vitreous hemorrhage included: branch retinal vein occlusion (48%), central retinal vein occlusion (16%), age-related macular degeneration (12%), retinal tear (8%), diabetic retinopathy (4%), rhegmatogenous retinal detachment (4%), Terson's syndrome (2%), Eales' disease (2%) and unknown causes (4%). The mean best-corrected visual acuity (BCVA) before surgery was 2.17 +/- 0.53 (log MAR) and it was recovered to 0.64 +/- 0.58 (log MAR) 6 months after the surgery (p < 0.001). The branch retinal vein occlusion showed better visual outcome than other disease entities. On funduscopic examination of the patients with poor visual outcome whose postoperative BCVA was poorer than 20/200, macular ischemia, macular degeneration, macular edema, submacular hemorrhage, tractional retinal detachment (including macular), or optic nerve atrophy were verified. CONCLUSIONS: After the vitrectomy for severe vitreous hemorrhage of unknown origin, pathologic findings of macular or irreversible optic nerve atrophy showed poor postoperative BCVA. Of all the causes of vitreous hemorrhage that were revealed after the surgery, branch retinal vein occlusion was the most common etiology of this condition and showed the most favorable visual outcome, comparatively.

Laparoscopic Treatment for Psoas Abscess / 대한정형외과학회잡지

Psoas abscess is a rare and high mortality disease if there is no appropriate treatment. The surgical approach of psoas abscess is very difficult because psoas muscle is anatomically located within retroperitoneum. Recently, computed tomography guided percutaneous catheter drainage with proper antibiotic therapy has shown good results. If this therapy fails to resolve the psoas abscess, surgical treatment may be necessary. We experienced two cases of psoas abscess resolved by surgical drainage using laparoscopy. We report two successful results with relevant literatures.

Ceramic Head Fracture in Ceramic-on-Polyethylene Total Hip Arthroplasty

Revision rates of total hip arthroplasty have decreased after introducing total hip arthroplasty (THA) using ceramic component, since ceramic components could reduce components wear and osteolysis. The fracture of a ceramic component is a rare but potentially serious event. Thus, ceramic on polyethylene articulation is gradually spotlighted to reduce ceramic component fracture. There are a few recent reports of ceramic head fracture with polyethylene liner. Herein, we describe a case of a ceramic head component fracture with polyethylene liner. The fractured ceramic head was 28 mm short neck with conventional polyethylene liner. We treated the patient by total revision arthroplasty using 4th generation ceramic on ceramic components.