GPS guided reverse shoulder arthroplasty.

BACKGROUND AND AIM OF THE WORK: The reverse shoulder arthroplasty (RSA) has risen exponentially, this has entailed an increasing number of complications and reoperations. In RSA, loads are transferred directly to the glenoid component. As a result, failure of the glenoid component is one of the most common complications. CT 3D preoperative planning, patient-specific and the possibility of performing a more precise and controlled surgical gesture in the operating room are increasingly important. The use of the GPS navigation on CT 3D planning has proved to be useful above all in terms of accuracy, reliability and the possibility of reproducing the planned gesture preoperatively. METHODS: This study analyzes the precision, safety, and reproducibility of the GPS system for the reverse shoulder prosthesis tested on 6 scapulohumeral cadaver specimens, subsequently subjected to anatomical dissection to verify the correct positioning of the glenoidcomponents and the percentage of appropriateness in the field of planning previously virtually assumed. RESULTS: Postoperative macroscopic dissection revealed no central peg perforated or screws malpositioned, no leaking from the bone or injury to the adjacent neurovascular structures. The average length of the screws was 42 mm (range 36 mm to 46 mm) for the lower screw and 40 mm for the upper one (range 36 mm to 42 mm). CONCLUSIONS: This cadaver study has shown that GPS navigation offers greater efficiency in baseplate and screws placement and can avoid intra- and postoperative complications.

Posterior Tibial Tendon Rupture Associated With Anterolateral Distal Tibial and Medial Malleolar Fracture and a Novel Pattern of Tibiofibular Syndesmotic Injury: A Case Report and Review of the Literature.

A posterior tibial tendon (PTT) rupture associated with ankle fractures is a very rare condition. Ankle pronation and external rotation (PER) movement are the typical traumatic mechanism. This injury is frequently overlooked preoperatively. Early diagnosis and treatment are very important to prevent the serious consequences related to functional PTT insufficiency on biomechanics of the foot. Few cases have been described in the literature that highlight the relationship between PTT rupture and PER type ankle fracture with a medial malleolar fracture. We present a case of a complete PTT rupture in a closed atypical ankle fracture in which a medial malleolar fracture was associated with a very large fragment from the anterolateral distal tibia (Tillaux-Chaput fragment) and a concomitant avulsion fracture from the anteromedial portion of the fibula (Lefort-Wagstaffe fragment), with a novel pattern never described before.

Pre-Operative CT-Based Planning Integrated With Intra-Operative Navigation in Reverse Shoulder Arthroplasty: Data Acquisition and Analysis Protocol, and Preliminary Results of Navigated Versus Conventional Surgery.

Reverse total shoulder arthroplasty (RSA) successfully restores shoulder function in different conditions. Glenoid baseplate fixation and positioning seem to be the most important factors influencing RSA survival. When scapular anatomy is distorted (eccentric osteoarthrirtis, rotator cuff arthropathy), optimal baseplate positioning and secure screw purchase can be challenging. The aim of this study was to evaluate whether CT-based pre-operative planning, integrated with intra-operative navigation could improve glenoid baseplate fixation and positioning by increasing screw length, reducing number of screws required to obtain fixation and increasing the use of augmented baseplate to gain the desired positioning. Twenty patients who underwent navigated RSA were compared retrospectively with 20 patients operated on with a conventional technique. All the procedures were performed by the same surgeon, using the same implant. Mean screw length was significantly longer in the navigation group (35.5 ± 4.4 mm vs 29.9 ± 3.6 mm; p = .001). Significant higher rate of optimal fixation using 2 screws only (17 vs 3 cases, p = .019) and higher rate of augmented baseplate usage (13 vs 4 cases, p = .009) was also present in the navigation group. Pre-operative CT-based planning integrated with intra-operative navigation can improve glenoid component positioning and fixation, possibly leading to an improvement of RSA survival.