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Introduction: Noise in ceramic-on-ceramic (CoC) total hip arthroplasty (THA) is a potential symptom of abnormal bearing wear. Squeaking and other prosthetic hip noises are multi-factorial phenomena that can be analysed and may provide prognostic information., Methods: 46 patients with noisy CoC bearings were investigated using X-ray, computed tomography and joint fluid analysis, and classified into either high or low risk of ceramic liner fracture groups according to previously published guidelines. Noise events from the bearings of 16 high risk cases which were subsequently revised were compared with 30 patients in the low risk control group who did not undergo revision. Noise events were analysed for their physical characteristics using a standardised protocol and classified as either low frequency and short duration 'clicking' or long duration and high frequency 'squeaking'., Results: The peak frequency of squeaking during forward walking was significantly higher for patients in the case group who were revised, compared with the control group. The patient-reported onset of squeaking (46 months postoperatively) was earlier than short-noise emissions (82 months). In the standardised sequence of movements, short-noise always occurred more frequently than squeaking. Small heads (28 mm) were more likely to develop short-noise, while large heads (⩾32 mm) were more likely to develop squeaking., Discussion: Noise evaluation may provide additional value for predicting failure of CoC bearings, though some questions should be better investigated in a dedicated prospective trial.

Introduction: Ceramic-on-ceramic (CoC) couplings are alternative bearings surfaces that have been reported to reduce osteolysis, wear debris and aseptic loosening compared to the use of polyethylene. Early experiences with ceramics had poor results, but they have led to many improvements in the manufacture and design of subsequent implants., Methods: We analysed medical files of 300 CoC total hip arthroplasty (THA) with a modular neck performed during period 1995-2000 by a single surgeon for a minimum follow-up of 13 years, evaluating clinical and radiological outcome., Results: The mean clinical Merle d'Aubigne and Postel hip score at the final follow-up is 17.4, against a preoperative value of 11.4. Overall survivorship with an endpoint of revision is 93.2% (95% CI, 89.0%-97.3%) at 15 years, while considering only prosthesis failures related to aseptic loosening and ceramic breakage, survival rate at 15 years is 97.2% (95% CI, 94.8%-100%). We observed complications that led to revision surgery in 11 patients (4%) (periprosthetic fractures, liner ruptures, septic loosening of the implant, aseptic loosening of the cup, aseptic loosening of the stem). The occurrence of squeaking is low (1.6%, 4 cases) and we analysed the characteristics of these patients., Discussion: Our study shows an excellent long term survivorship of third generation alumina CoC THA. We reiterate the importance to have a stable implant to maximise the advantage of ceramic and to avoid complications.

Hip replacement with large metal-on-metal (MoM) coupling has recently been under attention for its metal ions release, inducing several disorders. Since the blood level toxicity threshold for cobalt is known, the aim of this work is to determine whether Co serum and blood levels correlate with the synovial fluid level. Beside this, the synovial fluid Co from patients without prosthesis has also been measured. Co has been determined in 54 samples (32 unilateral MoM and 22 controls) with inductively coupled plasma mass spectrometry in the three matrices. In the prosthesized group, cobalt was significantly higher compared with controls and in the synovial fluid it strongly correlated with whole blood Co (p = 0.847) and serum (p = 0.855). Moreover, the Co levels into whole blood and serum were significantly different. In conclusion, haematic Co concentration correctly reflects Co local level.

The first clinical sign of ceramic hip prosthesis failure is hip noise. We therefore investigated whether isolation, observation at scanning electron microscopy, and chemical identification with microanalysis of particles from synovial fluid of "noisy hip" could be predictive of ceramic damage. Firstly, the level of "physiological wear" of well functioning ceramic-on-ceramic hip prostheses was assessed with this method, then the test was validated as diagnostic method for liner fracture. Twelve asymptomatic patients were enrolled to demonstrate the first aim; 39 cases of noisy hip (GROUP 1), and 7 cases of pending failure not related to ceramic (GROUP 2) were enrolled for the second aim. The analysis of the synovial fluid of the 12 asymptomatic patients allowed to set the "physiological wear" threshold. The analysis of GROUP 1 hips demonstrated the presence of ceramic particles (2 physiological, 12 mild, and 25 strong). The analysis of GROUP 2 showed a physiological presence of ceramic particles in all cases. Revision surgery in GROUP 1 was performed in 16 hips out 25 with strong ceramic particle presence and 2 out of 12 with mild ceramic particle presence. Failure of the ceramic component was evident in all but one of these cases, while the integrity of components was demonstrated in all seven hips of GROUP 2. Synovial fluid microanalysis can be a useful surrogate in predicting ceramic failure particularly when a strong presence of ceramic particles is observed. On the contrary there is not enough evidence to predict ceramic failure in presence of mild positivity., (Copyright © 2012 Orthopaedic Research Society.)

Preoperative diagnosis of septic loosening hip prosthesis is often challenging. Culture test on joint samples obtained during revision surgery is the diagnostic gold standard while the role of preoperative hip aspiration is still controversial. The aims of this prospective randomized study were to compare the sensitivity, specificity and accuracy of preoperative ultrasound-guided and fluoroscopic-guided aspiration, and to identify associated laboratory parameters or scintigraphy that could help in predicting septic loosing hip prosthesis. Sixty patients affected by persistent pain after hip prosthesis randomly received fluoroscopic-guided or ultrasound-guided hip aspiration before revision surgery. The results of culture tests of joint fluid presurgically and at surgery were compared. In addition, associated blood inflammatory markers and scintigraphy were evaluated. Ultrasound-guided aspiration showed a better sensitivity (69% vs. 27%), specificity (94% vs. 75%) and accuracy (83% vs. 40%) than fluoroscopic-guided aspiration. The combination of ultrasound-guided aspiration and C-reactive protein represents the best model to predict septic loosening hip prosthesis preoperatively., (Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

Background: Total hip replacement in developmental dysplasia of the hip is a demanding procedure and usually requires dedicated devices and special surgical techniques. Nevertheless, the described techniques have shown variable outcomes. The aim of this study was to assess the 11-year outcomes of an off-the-shelf modular neck prosthesis in dysplastic patients and to evaluate the ability of the modular neck system to adequately restore femoral offset, abductor muscles lever arm and leg length., Methods: We retrospectively evaluated 61 modular neck prostheses implanted in 47 patients between June 1995 and March 2004. The preoperative diagnosis was developmental dysplasia of the hip in all cases. The clinical outcomes were assessed using the Harris hip score and the Western Ontario and McMaster Universities score. The femoral offset, abductor muscles lever arm, height and medialization of the hip center of rotation, and differences in leg length were evaluated on postoperative radiographs. Prosthesis survival was calculated according to the Kaplan-Meier method considering any reason for revision as failure. The average follow-up was 117.2 months (range 57-162 months)., Results: The cumulative survival at 11 years was 97.5%. One prosthesis failed 5 years after surgery because of a ceramic liner fracture due to an inappropriate obstetric maneuver during labour. At the latest follow-up the mean Harris hip score was 74.7 (range 23-91). Leg length discrepancy was avoided in the majority of cases; femoral offset was almost always restored., Conclusions: The results of this series support the use of modular neck prostheses as an effective alternative in the treatment of developmental dysplasia of the hip. The modularity was very efficient in restoring offset, leg length and maintaining stability with a good mid-long-term follow-up. Unlike other proposed surgical techniques, these good results are achievable by a standard surgical technique and with an off-the-shelf prosthesis.