Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) can produce articular noise during the normal activities, generating discomfort to the patient. THA noise has to be investigated also as a potential predictor and a clinical sign of prosthetic failure. An observational study has been carried out to characterize the noise in CoC cementless THA, and to analyze the related factors. A total of 46 patients with noisy hip have been enrolled in 38 months, within the follow-up protocol normally applied for the early diagnosis of ceramic liner fracture [1]. Noise recording was based on a high-quality audible recorder (mod. LS 3, Olympus, Japan) and a portable ultrasonic transducer (mod USB AE 1ch, PAC, USA). The sensors for noise recording were applied to the hip of the patient during a sequence of repeatable motorial activities (forward and backward walking, squat, sit in a chair, flexion and extension of the leg). Sessions were also video-recorded to associate the noise emission to the specific movements. Each noise event was initially identified by the operator and therefore classified by comparison to the spectral characteristics (duration, intensity and frequency) of the main noise types. Number and spectral characteristics of noise events were obtained and correlated to the factors describing the clinical status of the patient, the surgical approach, the prosthetic device implanted. The study investigated also the noise as a sign of implant failure, by comparison with the total number of implants failed in the cohort during the study. We observed three types of noise with the main spectral characteristics in agreement to the literature: clicking, squeaking and popping. Among the identified types of noise, squeaking showed the longest duration and the highest amplitude. The 63% of hip presented the emission of just one type of noise, while the remaining a mix of types. The movement with the highest presence of noise was walking, followed by squat. Correlation was found between the noise type and the dimension of the ceramic head (p<0.001), with the sizes of 32 mm more affected by squeaking that the smaller one. Squeaking appeared before during the follow-up than the other types of noise. The 35% (16/46) of the noisy hips were revised during the study. Among the revised hips, the 81% (13/16) were affected by impingement and/or severe damage of the prosthetic components. The antiversion of the cup (p=0.008), the presence of debris in the synovial fluid (p=0.021) and the average frequency of squeaking (p=0.006) were significant predictors for the revision, but it has to be mentioned that the squeaking data was obtained on a small subset of revised patients. Ultrasonic analysis did not show significant correlations. The study presented and validated an experimental procedure to analyze noisy hips in clinical trials. Noise is confirmed to be a significant parameter in the follow-up evaluation of ceramic THA

Summary Statement. Discovery system produced effective functional improvement in both primary and revision total elbow replacement. The incidence of major complications was in an acceptable range. Introduction. The search for the ideal elbow prosthesis continues as instability and loosening remain the prime reasons for total elbow replacement (TER) failure. The Discovery Elbow System (Biomet) is one of the latest generations of linked prosthesis and has been used in UK since 2003. We report outcome of TER using this system. Methods. A total of 100 TERs (75 primary, 25 revisions) were performed between 2003 and 2010. The main primary underlying pathologies for TER were advanced rheumatoid arthritis (N=58), osteoarthritis (N=35), acute fractures (N=7). There were 60 female and 40 male patients with an average age of 62 years. The outcome assessment included pain, patient satisfaction, Liverpool Elbow Score (LES), range of movement, and imaging during a mean follow-up period of 48.5 months. Major complications are also reported. Results. For the whole patient group (primary + revision), the LES was significantly (p<0.001) improved from 3.79+/−1.71 to 6.36+/−1.85There were significant improvements in elbow flexion from 100°+/−24 to 118°+17, supination from 38°+/−26 to 50°+/−25 and pronation from 48°+/−22 to 61°+/−21. Mean improvement in flexion-extension and pronation-supination arc was 20° and 25°, respectively. 64% of cases were completely pain-free and at the final follow-up (compared to 7% preoperatively). Only 6% of patients scored “Not Satisfied” at the final follow-up. LES improvement was significantly higher in the primary TER compared to revision TER (p<0.05). Imaging reviewed for 60 cases showed loosening in 4% of patients. Other main complications included deep infection (N=2), ulnar neuropathy (N=3), pre-prosthetic fracture (N=2), and prosthetic failure (N=1). Discussion. TER using the Discovery Elbow System is an effective arthroplasty in terms of functional improvement, pain relief and range of motion in both primary and revision patients. TER resulted in no/mild pain in 78% of cases. Patients undergoing Acclaim, Souter-Strathclyde, GSB III, and Coonrad-Morrey TER have been reported to have no/mild pain in 64%, 67%, 50–92% and 60–100% of cases, respectively. A 20° improvement in flexion-extension arc is comparable to that of Acclaim (23°), Souter-Strathclyde (15°), GSBIII (19–33°), and Coonrad-Morrey (17–26°) TER. An improvement of 25° in pronation-supination arc in our series is also comparable to that of 21–28° reported the Coonrad-Morrey and 27–33° for Discovery prostheses. An infection rate of 2% is lower than several other reports for GSB III TER (7–11%) and Coonrad-Morrey (6–8%). The incidence of persistent ulnar neuropathy (3%) was lower compared to GSBIII TER (11–14%), Coonrad-Morrey (12–26%), and Acclaim (8%)

Objectives

The objective of this study was to develop a test for the rapid (within 25 minutes) intraoperative detection of bacteria from synovial fluid to diagnose periprosthetic joint infection (PJI).