Damage analysis of retrieved BioloxⓇdelta components used in hard and soft bearings.

This retrieval study included 43 Biolox delta explants (18 CoC, 25 CoP). Implants were examined macroscopically, whereby damage was evaluated using a semi quantitative scoring system. Confocal microscopy was used to examine wear related damage patterns of the articulating surfaces. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) was used to analyze wear marks on the implant surface and wear debris in periprosthetic tissue samples. Raman spectroscopy and X-ray diffraction (XRD) were used to quantify monoclinic zirconia fractions. On all components, in vivo wear resulted predominantly in different damage patterns caused by metal transfer. In CoC bearings stripe wear was additionally detected, and some implants underwent severe damage due to component breakage. The wear scores were higher for CoC components, with no differences between the scores for CoC heads and liners. Wear features caused comparable roughening on implants from CoC and CoP bearings. SEM studies demonstrated that most wear marks were caused by metal debris released from implant components. Grain pull-out was observed in stripe wear regions. Monoclinic phase shift was observed in a similar quantity on components from CoP and CoC bearings. The increase of monoclinic zirconia content around metal deposits was minimal and was more pronounced in areas of stripe wear. The results of this study indicate, that ZTA components in general undergo minimal wear in both, CoC and CoP bearings, however, it is more pronounced in the former. Metal deposits, as the most common wear feature, have no significant effect on monoclinic phase transition. STATEMENT OF SIGNIFICANCE: In this paper, we classify all damage patterns macroscopically according to an established scoring system and assess them regarding surface roughness (confocal microscopy) and monoclinic phase content (Raman spectroscopy) in order to derive the severity for patients. We compare hard-hard and hard-soft bearings and relate damage patterns with metal transfer based on SEM/EDS examinations. Furthermore, we work out correlations between patient-specific data, cause of revision and the physical condition of each individual sample Our cohort consists of 43 Biolox delta retrievals, a comparatively large quantity. In addition, we address current topics such as metal transfer and, based on the classification of damage patterns, provide incentives and/or meaningful focal points for further research.

Preoperative Risk Factors of Persistent Pain following Total Knee Arthroplasty.

Background: Despite good results of total knee arthroplasty (TKA) as a treatment of idiopathic osteoarthritis (OA) of the knee, significant number of patients (16-33%) complain of persistent pain of unknown origin. This phenomenon is the major cause of patient's dissatisfaction. It has been theorized that certain preoperative factors may increase the risk of persistent pain; hence, their identification should enable proper preoperative education and development of realistic expectations regarding results of TKA. This study is aimed at identifying the preoperative chronic pain predictors in patients undergoing TKA. Methods: In this prospective cohort study, patients scheduled for TKA were examined one day prior to surgery. Demographics, comorbidities, pressure pain thresholds, pain intensity and duration, radiographic OA grade, and range of motion were recorded. Questionnaires such as Beck Depression Inventory (BDI) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were collected. Study cohort was evaluated approximately 6 months following surgery. Patients were assigned to group A if they had no pain and to group B if they complained of any pain. Collected data was analyzed by biostatistician. Results: 64 patients were included in final analysis, 49 (76,6%) females and 15 (23,4%) males. Mean age was 67,6 yrs (48-84, ±7,42). Group A consisted of 21 patients (33%) while group B consisted of 43 patients (67%). There were no statistically significant differences regarding preoperative factors except for duration of preoperative pain, which was shorter in group A (36 (12-180) vs. 72 (24-180), p = 0,011). Every 12 months of preoperative pain were found to increase risk of persistent pain by 1,27 (p = 0,009). Conclusions: Preoperative duration of pain is a risk factor for chronic pain following TKA. Therefore, patients should be operated on as soon as indications arise. Should the surgical treatment of knee arthritis be postponed, intensive and individualized pain management is highly recommended.

Resection of Infrapatellar Fat Pad during Total Knee Arthroplasty Has No Impact on Postoperative Function, Pain and Sonographic Appearance of Patellar Tendon.

Routine resection of the infrapatellar fat pad (IFP) during total knee arthroplasty (TKA) is controversial, as it may result in shortening of the patellar tendon (PT) and anterior knee pain. This prospective study examined whether IFP excision during TKA affects joint function, anterior knee pain, PT dimensions and sonographic structure. A total of 65 consecutive patients undergoing TKA for osteoarthritis were randomized into two groups: IFP was resected in one and retained in the other. Patients were examined preoperatively, at 6 weeks and 6 months postoperatively: pain (Numerical Rating Scale-NRS), range of motion (ROM) and knee function (Knee Injury and Osteoarthritis Outcome Score-KOOS score) were evaluated; sonographic examination determined the length, structure and vascularity of the PTs. In both groups there were postoperative improvements in NRS and KOOS scores, although IFP resection did not influence clinical outcomes or sonographic parameters. At 6 weeks and 6 months postoperatively for both groups there were no differences between NRS scores (Mann-Whitney test, p = 0.511 and p = 0.579), ROM scores (Mann-Whitney test, p = 0.331, p = 0.180) or all KOOS subscores. IFP excision had no effect on sonographic parameters. This study suggests that IFP resection during TKA does not influence postoperative functional outcomes, pain scores, patellar tendon length and thickness, or sonographic structure.

Predicting Persistent Unclear Pain Following Primary Total Knee Arthroplasty.

Chronic post-surgical pain can be a considerable issue for patients undergoing primary total knee arthroplasty. According to the literature, persistent knee pain is experienced by up to 44% of patients. Most studies on total knee arthroplasty (TKA) outcomes have mainly investigated the biomechanics or function of the operated knee, but chronic pain has never been a primary issue. In recent years several possible predictors of chronic postsurgical pain have been investigated and eventually identified. A younger age, female gender, psychological distress, preoperative pain duration and intensity were all reported to influence chronic postoperative pain rates after total knee arthroplasty. Recently, it has also been hypothesized that preoperative signs of centrally driven hyperalgesia and distorted pain modulation may predict persistent knee pain in some patients. Despite the considerable number of patients suffering from chronic postsurgical pain after TKA, available data is scarce, and well controlled prospective studies are lacking. Predictors of chronic postsurgical pain after total knee arthroplasty have yet to be identified. Thus, this article is aimed at reviewing current knowledge on persistent pain after knee arthroplasty.

Evaluation of factors affecting persistence of atrial fibrillation in patients with concomitant atrial flutter treated with percutaneous radiofrequency current ablation of the right atrial cavotricuspid isthmus.

BACKGROUND: Atrial fibrillation (AF) and atrial flutter (AFL) often coexist. In some patients, AF remission is seen after successful percutaneous radiofrequency current ablation of the cavotricuspid isthmus (CTI). AIM: To evaluate factors affecting AF remission in patients with typical AFL and concomitant AF who underwent CTI ablation. METHODS: The study included consecutive 69 patients with typical AFL and concomitant clinically documented AF who underwent successful CTI ablation in 2003-2010. Based on the follow-up data from medical records and telephone interviews, the patients were divided into two groups: with persistent AF (group A) and with remission of AF (group B). This distinction was based on arrhythmia symptoms reported by the patient, such as palpitation or irregular heartbeat, and confirmed electrocardiographically (12-lead ECG or Holter monitoring). RESULTS: Group A included 47 patients, and group B included 22 patients. The two groups did not differ significantly in regard to the New York Heart Association (NYHA) functional class and concomitant diseases including diabetes, ischaemic heart disease, previous myocardial infarction and arterial hypertension. The two groups also did not differ by echocardiographically determined mean left ventricular ejection fraction (LVEF) and left atrial dimension (43.5 ± 9.27 vs. 39.27 ± 5.76, p = 0.075). Multivariate logistic regression did not identify any independent risk factors of AF persistence after CTI ablation. Univariate logistic regression also did not show arterial hypertension, type 2 diabetes, previous myocardial infarction, LVEF, left ventricular dimension or age to affect AF persistence after successful ablation. CONCLUSIONS: Based on the results of our study, we were unable to identify factors determining remission of AF coexisting with AFL in patients after percutaneous CTI ablation. These findings may indicate the need for complex ablation procedure (involving both CTI and pulmonary venous ostia ablation) in patients in whom these two arrhythmias coexist.