The Accuracy and Absolute Reliability of a Knee Surgery Assistance System Based on ArUco-Type Sensors

Recent advances allow the use of Augmented Reality (AR) for many medical procedures. AR via optical navigators to aid various knee surgery techniques (e.g., femoral and tibial osteotomies, ligament reconstructions or menisci transplants) is becoming increasingly frequent. Accuracy in these procedures is essential, but evaluations of this technology still need to be made. Our study aimed to evaluate the system's accuracy using an in vitro protocol. We hypothesised that the system's accuracy was equal to or less than 1 mm and 1° for distance and angular measurements, respectively. Our research was an in vitro laboratory with a 316 L steel model. Absolute reliability was assessed according to the Hopkins criteria by seven independent evaluators. Each observer measured the thirty palpation points and the trademarks to acquire direct angular measurements on three occasions separated by at least two weeks. The system's accuracy in assessing distances had a mean error of 1.203 mm and an uncertainty of 2.062, and for the angular values, a mean error of 0.778° and an uncertainty of 1.438. The intraclass correlation coefficient was for all intra-observer and inter-observers, almost perfect or perfect. The mean error for the distance's determination was statistically larger than 1 mm (1.203 mm) but with a trivial effect size. The mean error assessing angular values was statistically less than 1°. Our results are similar to those published by other authors in accuracy analyses of AR systems.

Percutaneus intermetatarsal ligament release and minimally invasive distal metatarsal osteotomy for treatment second intermetatarsal space syndrome

BACKGROUND AND OBJECTIVE

Since the description of the syndrome of the second intermetatarsal space, this is a common diagnosis among foot and ankle surgeons. However, no series have been published that consider this syndrome as its own entity. The objective of this study is to evaluate the clinical and radiological results of the release of the intermetatarsal ligament and minimally invasive distal metatarsal osteotomy in patients diagnosed with second space syndrome.

MATERIALS AND METHODS

An observational, longitudinal, retrospective study was carried out in patients with a clinical diagnosis of second space syndrome operated on using a minimally invasive technique. For the clinical results, the visual analog scale (VAS) for subjective pain, the Manchester-Oxford Foot Questionnaire (MOXFQ) and the scale for minor metatarsals and interphalangeals of the American Orthopedic Foot and Ankle Society (AOFAS-LMTS) were used for clinical-functional assessment. Consolidation or not of osteotomies was recorded and complications were recorded.

RESULTS

Twenty-nine feet in 29 patients were included in the study. After a mean follow-up of 39 months (25-50), clinically and statistically significant improvement was obtained in the scores: pain VAS, scales and subscales of the MOXFQ and the AOFAS-LMTS (p < 0.0001). All osteotomies healed at the end of follow-up and no major complications were recorded.

CONCLUSIONS

Percutaneous or minimally invasive surgery, in patients with second intermetatarsal space syndrome, obtains good clinical, functional and subjective results, with few complications. Therefore, we consider it an effective, safe and recommended technique in the hands of experienced surgeons.