This is the largest series of PJI by S. aureus managed with DAIR reported to date. The success rate was 55%. The use of rifampin may have contributed to homogenizing MSSA and MRSA prognoses, although the specific rifampin combinations may have had different efficacies.

The etiological diagnosis of prosthetic joint infection (PJI) requires the isolation of microorganisms from periprosthetic samples. Microbiological cultures often yield false-positive and false-negative results. 16S rRNA gene PCR combined with sequencing (16SPCR) has proven useful for diagnosing various infections. We performed a prospective study to compare the utility of this approach with that of culture to diagnose PJI using intraoperative periprosthetic samples. We analyzed 176 samples from 40 patients with PJI and 321 samples from 82 noninfected patients using conventional culture and 16SPCR. Three statistical studies were undertaken following a previously validated mathematical model: sample-to-sample analysis, calculation of the number of samples to be studied, and calculation of the number of positive samples necessary to diagnose PJI. When only the number of positive samples is taken into consideration, a 16SPCR-positive result in one sample has good specificity and positive predictive value for PJI (specificity, 96.3%; positive predictive value, 91.7%; and likelihood ratio [LR], 22), while 3 positive cultures with the same microorganism are necessary to achieve similar specificity. The best combination of results for 16SPCR was observed when 5 samples were studied and the same microorganism was detected in 2 of them (sensitivity, 94%; specificity, 100%; and LR, 69.62). The results for 5 samples with 2 positive cultures were 96% and 82%, respectively, and the likelihood ratio was 1.06. 16SPCR is more specific and has a better positive predictive value than culture for diagnosis of PJI. A positive 16SPCR result is largely suggestive of PJI, even when few samples are analyzed; however, culture is generally more sensitive.

Background:Dislocation following total knee arthroplasty (TKA) is the worst form of instability. The incidence is from 0.15 to 0.5%. We report six cases of TKA dislocation and analyze the patterns of dislocation and the factors related to each of them.Materials and Methods:Six patients with dislocation of knee following TKA are reported. The causes for the dislocations were an imbalance of the flexion gap (n=4), an inadequate selection of implants (n=1), malrotation of components (n=1) leading to incompetence of the extensor mechanism, or rupture of the medial collateral ligament (MCC). The patients presented complained of pain, giving way episodes, joint effusion and difficulty in climbing stairs. Five patients suffered posterior dislocation while one anterior dislocation. An urgent closed reduction of dislocation was performed under general anaesthesia in all patients. All patients were operated for residual instability by revision arthroplasty after a period of conservative treatment.Results:One patient had deep infection and knee was arthrodesed. Two patients have a minimal residual lag for active extension, including a patient with a previous patellectomy. Result was considered excellent or good in four cases and fair in one, without residual instability. Five out of six patients in our series had a cruciate retaining (CR) TKA designs: four were revised to a posterior stabilized (PS) TKA and one to a rotating hinge design because of the presence of a ruptured MCL.Conclusion:Further episodes of dislocation or instability will be prevented by identifying and treating major causes of instability. The increase in the level of constraint and correction of previous technical mistakes is mandatory.

BackgroundIsolated gastrocnemius contracture is thought to lead to numerous conditions. Although many techniques have been described for gastrocnemius recession, potential anesthetic, cosmetic, and wound-related complications can lead to patient dissatisfaction. Open and endoscopic recession techniques require epidural anesthesia, lower limb ischemia, and stitches and may lead to damage of the sural nerve, which is not under the complete control of the surgeon at all stages of the procedure.The purpose of this study was to evaluate the safety and efficacy of a new technique based on ultrasound-guided ultra–minimally invasive gastrocnemius recession.MethodsWe performed a pilot study with 22 cadavers to ensure that the technique was effective and safe. In the second phase, we prospectively performed gastrocnemius recession in 23 patients (25 cases) with chronic non-insertional Achilles tendinopathy, equinus foot, and other indications. In the clinical study, we evaluated the range of dorsiflexion before and after the procedure, clinical outcomes with VAS and AOFAS scores, and potential complications, including neurovascular injuries.ResultsWe achieved complete release of the gastrocnemius tendon in all cases in the cadaveric study, with no damage to the sural nerve or vessels and minimal damage to the underlying muscle fibers. Ankle dorsiflexion increased for every patient in the study (mean, 14°; standard deviation, 3°) and was maintained throughout follow-up. The mean preoperative VAS score was 7 (6–9), which improved to 0 (0–1). The AOFAS Ankle-Hindfoot Score improved from a mean of 30 (20–40) to 93 (85–100) at 6 months. No major complications were observed. All patients returned to their previous sports after 6 months.ConclusionsAfter cadaveric and clinical study, we considered the technique to be safe and effective to perform ultrasound-guided ultra–minimally invasive gastrocnemius recession using a 1-mm incision in vivo. This novel technique represents an alternative to open techniques, with encouraging results and with the advantages of reducing pain, obviating lower limb ischemia, deeper anaesthesia, thus decreasing complications and contraindications and accelerating recovery.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-016-1265-7) contains supplementary material, which is available to authorized users.

This study describes a new ultrasound-guided surgical technique for aponeurotomy and interphalangeal joint capsular release in patients with Dupuytren’s disease and analyses the clinical outcomes. We carried out a retrospective review of 70 digits in 35 patients who underwent ultrasound-guided aponeurotomy and interphalangeal joint capsular release, with a minimum follow-up of 2 years. The primary outcome was the correction of the deformity and the QuickDASH questionnaire score after surgery and at 1 and 2 years. The secondary outcome was the presence of residual contracture immediately after surgery. The mean QuickDASH score fell from 28 before surgery to 14 after surgery. A significant decrease of −63° was observed for the global contracture, −35° the metacarpophalangeal joint contracture and −28° for the proximal interphalangeal joint contracture. Ultrasound-guided aponeurotomy and interphalangeal joint capsular and palmar plate releases are highly accurate and safe. Level of evidence: IV