Increased accuracy in component positioning using an image-less robotic arm system in primary total knee arthroplasty: a retrospective study.

BACKGROUND: Robotic-assisted total knee arthroplasty (RTKA) and navigated total knee arthroplasty (NTKA) have shown improved knee alignment and reduced radiographic outliers. Recent studies have proven that conventional mechanical alignment may not be the optimal goal for every patient. The aim of this study was to compare the accuracy of the planned implant positioning of a novel image-less robotic technique with an established navigated technique (NTKA). METHOD: The study is a retrospective analysis of prospectively collected data that compared the implant positioning and lower-limb alignment of 86 image-less RTKA with 86 image-less NTKA. Radiographic analysis was performed to evaluate the lower-limb overall alignment, femoral and tibial components positioning in the coronal and sagittal planes. Outliers were evaluated with a cutoff of ± 3°. RESULTS: No difference was noted between the two groups for radiographic outliers within ± 3° from neutral (p = 0.098). The mean hip-knee-ankle angle deviation from target was 1.3° in the RTKA group compared to 1.9° in the NTKA (p < 0.001). Femoral sagittal deviation (femoral component flexion) was smaller in the RTKA group (0.9° vs 1.9°; p < 0.001). Similarly, tibial coronal deviation (0.8° vs 1.5°; p < 0.001) and tibial sagittal deviation (tibial slope) were smaller in the RTKA group compared to the NTKA group (0.9° vs 1.7°; p < 0.001). CONCLUSIONS: The RTKA group reported a substantial and significant reduced error from the planned target angles for both tibial and femoral components. No difference in terms of radiographic outliers was noted between navigation and robotic assistance.

High accuracy of a new robotically assisted technique for total knee arthroplasty: an in vivo study.

PURPOSE: Over the last decade, robotic TKA gained popularity for improving the accuracy of implant positioning and reducing outliers in limb alignment comparing to conventional jig-based TKA. Hypothesis of this study was that this newly designed robotically assisted system will achieve a high level of accuracy for bone resection. Purpose of the study was to evaluate the accuracy of the system. METHODS: For this study, 75 knees in 75 patients were operated using a new, robotic system (ROSA® Knee System; Zimmer Biomet, Warsaw, IN) with a Posterior Stabilized Total Knee Arthroplasty (Persona® Knee System). The planned, validated and measured angles and cuts for the distal and posterior femur, for the proximal tibia and for the final coronal alignment on long standing x-rays were compared. RESULTS: A statistically significant difference was found only between the average planned and the average validated angle for femoral flexion, tibial coronal axis, medial and lateral cuts; the average difference was in any case below 1 mm or under 1 degree with SD < 1. No statistical difference was found between planned validated and measured cuts. Average difference between planned HKA and measured was 1.2 ± 1.1. No statistically significant difference was found. CONCLUSIONS: The results of this study demonstrated that using this new surgical robot in total knee arthroplasty it is possible to perform accurate bone cuts and to achieve the planned angles and resections.

A well performing medial fixed bearing UKA with promising survivorship at 15 years.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) accounts for 10% of knee arthroplasty procedures in Europe. Fixed bearing UKA designs have shown favorable survivorship in registries when compared with mobile bearings. This study analyses long-term follow-up of patients with a medial fixed bearing metal backed tibial UKA and reports 15 years survivorship and clinical outcomes. METHODS: Data were collected prospectively for 148 medial unicompartmental fixed bearing metal backed UKAs implanted in 148 patients in two high volumes knee arthroplasty centers between January 2005 and December 2007. The indication was osteoarthritis in all but 2 patients. Patients' reported outcome scores were documented at last follow up. The mean patient age at time of surgery was 65 years. RESULTS: At final follow up, outcome and survivorship data were collected for 124 medial fixed bearing UKAs. Thirteen patients underwent revision; average time to revision was 77 months (SD 35.31). The Kaplan-Meier analysis demonstrated a survivorship of 97.65% at 69 months and of 89,52%. at 120 months and 173 months of follow-up. When revisions for infection were excluded, the survivorship of the implant was 90.3% at the last of follow up. The mean OKS was 43.02 (SD 5.1) at the last follow-up, and the mean FJS was 77.6 (SD 6.9). CONCLUSION: This Medial fixed bearing metal backed UKA demonstrates promising long-term survivorship and patient outcomes. It appears to be a suitable and reasonably lasting option for the treatment of medial compartment OA.

A new robotically assisted technique can improve outcomes of total knee arthroplasty comparing to an imageless navigation system.

BACKGROUND: Robotic assisted total knee arthroplasty (RTKA) has shown improved knee alignment and reduced radiographic outliers. However, there remains debate on functional outcomes and patient-reported outcomes (PROMs). This study compares the 1-year clinical outcomes of a new imageless robotically assisted technique (ROSA Knee System, Zimmer Biomet, Warsaw, IN) with an imageless navigated procedure (NTKA, iAssist Knee, Zimmer, Warsaw, IN). METHODS: The study is a retrospective analysis of prospectively collected data that compared the functional outcomes and PROMs of 50 imageless RTKA with 47 imageless NTKA at 1-year follow-up. Baseline characteristics, intraoperative and postoperative information were collected including complications, revisions, Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS) score, and Forgotten Joint Score (FJS-12). Radiographic analysis of preoperative and postoperative images evaluating hip-knee-ankle (HKA) angle was performed. RESULTS: There was no difference regarding baseline characteristics between the groups. Mean operative time was significantly longer in the RTKA group (122 min vs. 97 min; p < 0.0001). Significant differences were reported for the "Pain" (85 [RTKA] vs 79.1 [NTKA]; p = 0.0283) subsection of the KOOS score. In addition, RTKA was associated with higher maximum range of motion (119.4° vs. 107.1°; p < 0.0001) and better mean improvement of the arc of motion by 11.67° (23.02° vs. 11.36°; p < 0.0001). No significant differences were noted for other subsections of KOOS, KSS, FJS-12, complications, or limb alignment at 1-year follow-up. CONCLUSIONS: Imageless RTKA was associated with longer surgical time, better pain perception and improved ROM at 12-month follow-up compared with NTKA. No significant differences were reported on other PROMs, complication rates and radiographic outcomes. LEVEL OF EVIDENCE: III.

The Anterior Lateral Decubitus Intermuscolar and the Postero-Lateral approaches in total hip arthroplasty: a comparative study.

BACKGROUND AND AIM: Recently a modification of the DAA in lateral decubitus, called ALDI, has been proposed to obtain a better surgical exposure and to facilitate surgeons accustomed to the other hip approach. In this paper we report our early experience with the ALDI approach for total hip arthroplasty (THA) and to compare outcomes between ALDI and posterolateral approach (PLA) in a retrospective investigation. METHODS: We have identified THA performed from September 2017 to January 2020. We collected patients demographic, clinical and radiographic data by our electronic hospital database. The ALDI group included 60 hips and the PLA group included 219 hips. These patients underwent to strict follow-up in the first 3 post-operative months. RESULTS: Compared to the PLA, the ALDI approach showed clinical outcomes significantly higher in the first month of follow-up. The PLA group has a lower operative time and a greater mean hospital length of stay. No blood transfusions were administered in the ALDI group while the 1.4% of patients in the PLA group needed blood transfusion. Cup anteversion and inclination angles were significantly wider in the PLA group. THA dislocation occurred in seven patients of the PLA group. No femoral cutaneus nerve palsy was recorded in the ALDI group. CONCLUSIONS: The ALDI approach can represent a quickly and safe solution for surgeons who are accustomed to the PLA who want to perform THA in DAA. Our preliminary experience is encouraging in terms of clinical and radiographic parameters although the operative time needs to be improved.

Three-year National report from the Gruppo Italiano di Ortogeriatria (GIOG) in the management of hip-fractured patients.

BACKGROUND: Hip fractures (HF) are a major issue worldwide. We aimed at evaluating the practices in delivering care to patients with HF among several Italian Orthogeriatric centers. METHODS: The study took place from February 2016 to July 2018. Seven performance indicators (pre-surgical cognitive assessment, surgery performed ≤ 48 h from fracture, removal of urinary catheter/absence of delirium/start of physiotherapy on the first post-operative day, prescription of bone protection at discharge, and discharge toward rehabilitation) were collected. RESULTS: The 14 participating hospitals totally recruited 3.017 patients. Patients were old (median age 86 years; Inter Quartile Range [IQR] 80-90), mostly females (77%). Nearly 55% of them were already impaired in mobility and about 10% were nursing home residents. Median time-to-surgery was 41 h (IQR 23-62). Models of care greatly varied among centers, only 49.3% of patients being co-managed by geriatricians and orthopedics. There was high variability across centers in four indicators ("pre-surgical cognitive assessment", "bone protection prescription", "use of urinary catheter" and "start of physiotherapy"), moderate in two indicators ("surgery performed ≤ 48 h from fracture" and "discharge toward rehabilitation" and low in one ("absence of delirium on day following surgery"). Comparison with international studies suggests very different ways of providing care to HF Italian patients. CONCLUSIONS: The study results suggest high inter-center variability in the key-performance indicators, and different approaches in providing care to our HF patients in comparison to other countries. A National debate on the topic is required in Italy to harmonize practices of orthogeriatric care.

Association of postoperative delirium with markers of neurodegeneration and brain amyloidosis: a pilot study.

The aim of the study was to investigate the association between postoperative delirium (POD) and in vivo markers of Alzheimer's disease pathology in nondemented hip fracture surgery patients. POD was assessed with the Confusion Assessment Method. Amyloid load was quantified on 18F-Flutemetamol positron emission tomography images as standardized uptake value ratio. Secondary outcome measures were gray matter volumes, white matter integrity, and functional connectivity at rest. All the patients with POD (POD+, N = 5) were amyloid negative (standardized uptake value ratio <0.59), whereas 6 out of 11 patients without POD (POD-) showed brain amyloid positivity. POD+ compared to POD- displayed: lower gray matter volumes in the amygdala (p = 0.003), in the middle temporal gyrus and in the anterior cingulate cortex (p < 0.001), increased diffusivity in the genu of the corpus callosum and in the anterior corona radiata (p < 0.05), and higher functional connectivity within the default mode network (p < 0.001). POD patients showed altered gray and white matter integrity in the fronto-limbic regions in absence of brain amyloidosis. Based on this preliminary investigation, delirium pathophysiology might be independent of Alzheimer's disease. Future studies on larger samples are needed to confirm this hypothesis.