The Pivot-shift phenomenon (PS) is known to be one of the essential signs of functional insufficiency of the anterior cruciate ligament (ACL). To evaluate the dynamic knee laxity is very important to accurately diagnose ACL injury, to assess surgical reconstructive techniques, and to evaluate treatment approaches. However, the pivot-shift test remains a subjective clinical examination difficult to quantify. The aim of the present study is to validate the use of an innovative non-invasive device based on the use of an inertial sensor to quantify PS test. The validation was based on comparison with data acquired by a surgical navigation system. The surgeon intraoperatively performed the PS tests on 15 patients just before fixing the graft required for the ACL reconstruction. A single accelerometer and a navigation system simultaneously acquired the joint kinematics. An additional optical tracker set to the accelerometer has allowed to quantify the movement of the sensor. The tibial anteroposterior acceleration obtained with the navigation system was compared with the acceleration acquired by the accelerometer. It is therefore estimated the presence of any artifacts due to the soft tissue as the test-retest repositioning error in the positioning of the sensor. It was also examined, the repeatability of the acceleration parameters necessary for the diagnosis of a possible ACL lesion and the waveform of the output signal obtained during the test. Finally it has been evaluated the correlation between the two acceleration measurements obtained by the two sensors. The RMS (root mean square) of the error of test-retest positioning has reported a good value of 5.5 ± 2.9 mm. While the amounts related to the presence of soft tissue artifacts was equal to 4.9 ± 2.6 mm. It was also given a good intra-tester repeatability (Cronbach's alpha = 0.86). The inter-patient similarity analysis showed a high correlation in the acceleration waveform of 0.88 ± 0.14. Finally the measurements obtained between the two systems showed a good correlation (rs = 0.72, p<0.05). This study showed good reliability of the proposed scheme and a good correlation with the results of the navigation system. The proposed device is therefore to be considered a valid method for evaluating dynamic joint laxity.
A key of success in the treatment of prosthetic joint infection (PJI) is the proper diagnosis. There is a lack of diagnostic tools able to diagnose a PJI with high accuracy. Alpha-defensin has been proposed as possible solution but the available literature is still limited. This prospective study was carried out in order to determine (1) what is the sensitivity, the specificity, the positive and the negative predictive value of the Alpha-defensin immunoassay test in diagnosing PJI; (2) which clinical features may be responsible for false positive and false negative results? Preoperative aspiration was performed in patients presenting with a painful hip/knee arthroplasty. Metallosis, other inflammatory comorbidities and previous/concomitant antibiotic therapy were not considered as exclusion criteria. Patients with inadequate amount of synovial fluid for culture were excluded. At time of revision synovial fluid samples were taken in the OR in order to perform Alpha-defensin assay. During surgical debridement tissue samples for cultures were obtained. Prospectively, 156 patients (65 knees and 91 hips) were included. A diagnosis of PJI was confirmed in 29 patients.Aim
Method
This study aimed to intra-operatively quantify the improvements in knee stability given both by anatomic double-bundle (ADB) and single-bundle with additional lateral plasty (SBLP) ACL reconstruction using a navigation system. We prospectively included 35 consecutive patients, with an isolated anterior cruciate ligament injury, that underwent both ADB and SBLP ACL reconstruction (15 ADB, 20 SBLP). The testing protocol included anterior/posterior displacement at 30° and 90° of flexion (AP30–AP90), internal/external rotation at 30° and 90° of flexion (IE 30–IE90) and varus/valgus test at 0° and 30° of flexion (VV0–VV30); pivot-shift (PS) test was used to determine dynamic laxity. The tests were manually performed before and after the ACL reconstruction and the data were acquired by means a surgical navigation system (BLU-IGS, Orthokey, USA). Comparisons of pre- and post-reconstruction laxities were made using paired Student t-test (P=0.05) within the same group; comparison between ADB and SBLP groups was indeed performed using independent Student t-test (P=0.05), analysing both starting pre-operative condition and post-operative one.INTRODUCTION
MATERIALS AND METHODS
We hypothesized that patients receiving a medial collagen meniscus implant (MCMI) would show better clinical, radiograpich and Magnetic Resonanace Imaging (MRI) outcomes than patients treated with partial medial meniscectomy (PMM) at minimum 10 year FU. Thirty-three non-randomized patients (males, mean age 40 years) were enrolled in the study to receive a MCMI (17 patients) or as control treated with a PMM (16 patients). All of them were clinically evaluated at time zero, 5 and minimum 10 years after surgery (mean FU 133 months, range 120–145) by Lysholm, VAS for pain, objective IKDC knee form and Tegner activity level. SF-36 score was performed pre-operatively and at final FU. Bilateral weight-bearing XRays were executed at time zero and at final FU. Minimum 10 years FU MRI images were compared with collected pre-operative MRI images by means of Yulish score. Genovese score was also used to evalute MCMI MRI survivorship.Purpouse
Material and Methods
We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome. Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups. Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (
