A novel quantitative grading system for implant fixation in revision total knee arthroplasty.

Aims: Obtaining solid implant fixation is crucial in revision total knee arthroplasty (rTKA) to avoid aseptic loosening, a major reason for re-revision. This study aims to validate a novel grading system that quantifies implant fixation across three anatomical zones (epiphysis, metaphysis, diaphysis). Methods: Based on pre-, intra-, and postoperative assessments, the novel grading system allocates a quantitative score (0, 0.5, or 1 point) for the quality of fixation achieved in each anatomical zone. The criteria used by the algorithm to assign the score include the bone quality, the size of the bone defect, and the type of fixation used. A consecutive cohort of 245 patients undergoing rTKA from 2012 to 2018 were evaluated using the current novel scoring system and followed prospectively. In addition, 100 first-time revision cases were assessed radiologically from the original cohort and graded by three observers to evaluate the intra- and inter-rater reliability of the novel radiological grading system. Results: At a mean follow-up of 90 months (64 to 130), only two out of 245 cases failed due to aseptic loosening. Intraoperative grading yielded mean scores of 1.87 (95% confidence interval (CI) 1.82 to 1.92) for the femur and 1.96 (95% CI 1.92 to 2.0) for the tibia. Only 3.7% of femoral and 1.7% of tibial reconstructions fell below the 1.5-point threshold, which included the two cases of aseptic loosening. Interobserver reliability for postoperative radiological grading was 0.97 for the femur and 0.85 for the tibia. Conclusion: A minimum score of 1.5 points for each skeletal segment appears to be a reasonable cut-off to define sufficient fixation in rTKA. There were no revisions for aseptic loosening at mid-term follow-up when this fixation threshold was achieved or exceeded. When assessing first-time revisions, this novel grading system has shown excellent intra- and interobserver reliability.

Restoration of pre-operative joint line orientation and alignment does not affect KSS and KOOS 1 year after total knee arthroplasty.

PURPOSE: The objectives of this study were to examine the relation between clinical outcomes 1 year postoperatively, in a cohort of mechanically aligned total knee arthroplasties (TKA), and (1) the degrees of alignment change of the tibial, femoral and the hip-knee-ankle (HKA) angle; (2) the change of phenotype; (3) the postoperative knee joint line orientation to the floor. METHODS: Pre-operative and postoperative long-leg X-rays of 90 patients were used to determine the coronal alignment. The absolute difference between the pre-operative and postoperative measurements was determined and the outcomes were categorized in whether or not a change in phenotype had occurred. Finally, the orientation of the knee joint line relative to the floor (tibial joint line angle-TJLA) was measured. Clinical outcomes were determined with the KOOS and KSS at 1-year follow-up. RESULTS: The clinical outcomes (1) did not correlate with the absolute difference of the alignment measured; (2) did not show a difference between patients with or without a change in phenotype; and (3) were higher (KOOS ADL, Sport and QoL) in patients with a medial open TJLA. CONCLUSION: This study showed no correlation between clinical outcomes and joint line restoration of the femur, tibia or HKA in patients after TKA. Leaving the prosthesis with some degrees of under correction on the coronal plane maintaining the phenotype, was not associated to better clinical results compared to TKA overcorrection. Nevertheless, the results showed that patients with a medial open TJLA had better clinical outcomes than patients with a lateral open TJLA. LEVEL OF EVIDENCE: III.

Does navigated patellar resurfacing in total knee arthroplasty result in proper bone cut, motion and clinical outcomes?

BACKGROUND: In total knee arthroplasty with patellar resurfacing, patellar bone preparation, component positioning and motion assessments are still not navigated. Only femoral/tibial component positioning is supported by computer-assistance. The aim of this study was to verify, in-vivo, whether knee surgical navigation extended to patellar resurfacing, by original instrumentation and procedures for patellar-based tracking, could achieve accurate patella preparation in terms of original thickness restoration, bone cut orientation, and normal knee motion. METHODS: An additional navigation system for patellar data acquisition was used together with a standard navigation system for total knee arthroplasty in 20 patients. This supported the surgeon for patellar resurfacing via measurement of removed bone thickness, three-dimensional patellar cut orientations, and patello-femoral motion. Radiological and clinical examinations at 6 and 24-month follow-up were also performed. FINDINGS: The medio-lateral patellar-bone cut orientation was respectively 0.5° (standard deviation: 3.0°) and 1.4° (1.7°) lateral tilt, as measured via navigation and post-operatively on the Merchant x-ray view. The cranio-caudal orientation was 3.8° (7.2°) of flexion. The thickness variation between patellar pre- and post-implantation was 0.2 (1.3) mm. Immediately after implantation, patello-femoral as well as tibio-femoral kinematics was within the normality. Good radiological and clinical examinations at 6 and 24-month follow-up were also observed. INTERPRETATION: For the first time, the effect of patellar navigation for its resurfacing was assessed in-vivo during surgery, with very good results for thickness restoration, proper cut orientation, and normal knee motion. These results support the introduction of patella-related navigation-based surgical procedures for computer-assisted total knee arthroplasty.

Conventional versus computer-assisted surgery in total knee arthroplasty: comparison at ten years follow-up.

PURPOSE: Computer-assisted systems (CAS) for total knee arthroplasty (TKA) were expected to result in more accurate prosthesis implantation, better patient outcomes, and longer implant survival when compared to conventional instrumentation (CI). The aim of this study was to compare two groups of patients operated using CAS or CI at ten years follow-up. METHODS: One hundred twenty TKA patients, 60 using CAS and 60 using CI, were contacted after a decade for follow-up. Eligible patients received radiological examination to assess the lower-limb mechanical axis. They were also clinically assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Knee Society Score for Knee (KSS-K) and Function (KSS-F) Scoring. Kaplan-Meier survival analysis was performed to assess revisions, not for post-traumatic reasons. RESULTS: In CAS and CI groups, the lower-limb mechanical axis was 1.7° ± 2.4° and 1.5° ± 2.8°, respectively; corresponding KOOS values were 82.3 ± 14.3 and 78.6 ± 14.4; KSS-K values were 85.9 ± 11.1 and 85.0 ± 9.7; KSS-F values were 82.2 ± 19.3 and 83.8 ± 18. For these assessments, the differences between the two groups were not statistically significant (p > 0.05). Two CAS (3.8%) and three CI patients (5.7%) were revised. The Kaplan-Meier analysis showed no significant differences between the two groups. CONCLUSIONS: No significant differences were found at long-term follow-up in terms of radiographical-clinical outcomes and of implant survival between TKA operated using CAS or CI.

High performance of α-defensin lateral flow assay (Synovasure) in the diagnosis of chronic knee prosthetic infections.

PURPOSE: This prospective study was undertaken to evaluate the diagnostic accuracy of the Synovasure™ α-defensin lateral flow assay to detect or exclude infection and to compare it to the sensitivity and specificity of other diagnostic criteria according to the International Consensus Group on Periprosthetic Joint Infection (PJI). METHODS: All patients who have undergone revision total knee arthroplasty (TKA) from September 2015 to July 2016 were included: 16 chronic (more than 3 months after performing arthroplasty) infections and 35 aseptic joints were identified. The diagnostic performance of single test was assessed by receiver operating characteristic (ROC) curve analyses. The sensitivity and specificity were calculated for each of the cut-off values and the area under the curve (AUC) was also calculated. RESULTS: The median synovial fluid (SF) leukocyte count, as well as the neutrophil percentage, was significantly higher in patients with PJI than in those with aseptic failure (p < 0.001). The sensitivity of α-defensin was 87.5% (95%; CI 74.6-94.7), the specificity was 97.1% (95% CI 86.9-99.7), the positive predictive value 93.3% (95% CI 81.8-98.1), and negative predictive value was 94.4% (95% CI 83.2-98.6). The results in terms of sensitivity and negative predictive value were greater than those of the other tests (cultures, synovial cell count, erythrocyte sedimentation rate, and C-reactive protein). The diagnostic accuracy of α-defensin, with an area under the curve of 0.92, was found to be higher than all the minor criteria for PJI. CONCLUSIONS: In this study, the α-defensin lateral flow test was found to have the highest performance of all tests studied to identify PJI. Synovasure™ holds the potential to be included in the daily clinical practice. LEVEL OF EVIDENCE: Level I diagnostic study.

Laparoscopic treatment of adrenal masses in children: Report of two cases and review of literature.

Laparoscopic adrenalectomy has become a common alternative to open surgery for the resection of adrenal lesions in adults: The advantages are to provide better exposure of the adrenal gland, diminish soft tissue dissection, decrease morbidity and postoperative pain; however, reporting on the laparoscopic adrenalectomy in paediatric patients has been limited. We present two cases of laparoscopic adrenalectomy performed at our institution in two children, for left adrenal neuroblastoma in a first patient with opsomyoclonus syndrome, and for a right incidentaloma in the second case. According to recent literature, our experience has demonstrated that the laparoscopic adrenalectomy is a feasible procedure in children with small, well-circumscribed adrenal masses: It can be used a safety to treat suspected benign and malignant adrenal masses in children, with minimal morbidity and short hospital stay. The lateral trans-peritoneal approach offers optimal visualisation and good outcomes in terms of minimal discomfort, rapid recovery and excellent cosmesis. However, in the paediatric field, the number of patients is limited, making the learning curve longer.

Congenital hip dysplasia treated by total hip arthroplasty using cementless tapered stem in patients younger than 50 years old: results after 12-years follow-up.

BACKGROUND: Congenital hip dysplasia may lead to severe acetabular and femoral abnormalities that can make total hip arthroplasty a challenging procedure. We assessed a series of patients affected by developmental hip dysplasia treated with total hip arthroplasty using cementless tapered stem and here we report the outcomes at long-term follow-up. MATERIALS AND METHODS: Twenty-eight patients (24 women and 4 men) aged between 44 and 50 years (mean 47 years) were observed. Clinical evaluation was rated with the Harris Hip Score. Radiographic evaluation consisted in standard anteroposterior and axial view radiographs of the hip. According to Crowe's classification, 16 hips presented dysplasia grade 1, 14 grade 2, and 4 grade 3. All patients were treated with total hip arthroplasty using a cementless tapered stem (Wagner Cone Prosthesis). Six patients were operated bilaterally, with a totally of 34 hips operated. After surgery, the patients were clinically and radiographically checked at 3, 6, and 12 months and yearly thereafter until an average follow-up of 12 years (range 10-14 years). RESULTS: Average Harris Hip Score was 56 ± 9 (range 45-69) preoperatively, 90 ± 9 (range 81-100) 12 months after surgery, and 91 ± 8 (range 83-100) at last follow-up. Radiographic evaluation demonstrated excellent osteointegration of the implants. Signs of bone resorption were present in 6 hips, nevertheless no evidence of loosening was observed and none of the implants has been revised. CONCLUSIONS: Even in dysplasic femur, the tapered stem allowed adequate stability and orientation of the implant. We consider tapered stem a suitable option for total hip arthroplasty in developmental hip dysplasia, also in case of young patients, thanks to the favourable long-term results.

[Foreign body ingestion in children: our experience and review of the literature]. / La ingestione di corpi estranei in eta' pediatrica: nostra esperienza e revisione della letteratura.

Foreign body ingestion is a frequent event in paediatric population, especially in the first six years of life. Even if the event is normally cause of anxiety for the parents witness of the situation, fortunately most ingested foreign bodies ingestion, about 80-90%, pass spontaneously, 10-20% of cases needs an endoscopic intervention and only in less than 1% of cases surgery is necessary. Many authors suggest different guide-lines for diagnosis and therapy of foreign body ingestion in children. These purposes are discordant not only on potential danger of foreign body, but also on timing and last of waiting period before endoscopic extraction. Here we report our own experience: a retrospective review of three hundred consecutive paediatric cases of foreign body ingestion between June 2001 and February 2008. This study don't take in account patients with pathology either organic either functional, that can cause stop of food progression. We describe and discuss about medical diagnostic and therapeutic procedures that have been done during the time of hospitalization and performed according to classic and new international literature, with the objective to propose recommendations helpful for a correct management of children presenting with a history of suspected ingestion of a foreign body.