Augmented-reality-assisted K-wire placement for glenoid component positioning in reversed shoulder arthroplasty: a proof-of-concept study

The accuracy of the implant’s post-operative position and orientation in reverse shoulder arthroplasty is known to play a significant role in both clinical and functional outcomes. Whilst technologies such as navigation and robotics have demonstrated superior radiological outcomes in many fields of surgery, the impact of augmented reality (AR) assistance in the operating room is still unknown. Malposition of the glenoid component in shoulder arthroplasty is known to result in implant failure and early revision surgery. The use of AR has many promising advantages, including allowing the detailed study of patient-specific anatomy without the need for invasive procedures such as arthroscopy to interrogate the joint’s articular surface. In addition, this technology has the potential to assist surgeons intraoperatively in aiding the guidance of surgical tools. It offers the prospect of increased component placement accuracy, reduced surgical procedure time, and improved radiological and functional outcomes, without recourse to the use of large navigation or robotic instruments, with their associated high overhead costs. This feasibility study describes the surgical workflow from a standardised CT protocol, via 3D reconstruction, 3D planning, and use of a commercial AR headset, to AR-assisted k-wire placement. Post-operative outcome was measured using a high-resolution laser scanner on the patient-specific 3D printed bone. In this proof-of-concept study, the discrepancy between the planned and the achieved glenoid entry point and guide-wire orientation was approximately 3 mm with a mean angulation error of 5°

Gorham-Stout syndrome (GSS) with fulminant aseptic osteonecrosis of the shoulder

We report here a case of the rare Gorham-Stout syndrome (GSS) of the humerus. GSS is a disease in the course of which spontaneous idiopathic osteolysis occurs. We describe a case of a 46-year-old business economist who suffered an inadequate trauma and within 3 weeks developed self-limited idiopathic osteolysis of the left humerus head, also affecting the rotator cuff This could be diagnosed especially on the basis of histopathological findings. Hereupon we indicated operative repair by means of inverted shoulder joint endoprosthesis

Influence of hip replacement on sagittal alignment of the lumbar spine: An EOS study

INTRODUCTION: Changes in pelvic position can influence the sagittal alignment of the lumbar spine. The restoration of hip kinematics by hip replacement thus appears to offer the possibility of correcting sagittal alignment. This preliminary retrospective study used EOS imaging to investigate the influence of total hip arthroplasty on pelvic parameters in patients with normal preoperative pelvic parameters. METHODS: Twenty patients with hip osteoarthritis undergoing total hip arthroplasty (THA) between 2011 and 2012 received unilateral THA. To evaluate the preoperative and postoperative changes of the pelvic parameters, we analyzed EOS imaging of the patients to determine pelvic incidence, sacral slope, sacral tilt, pelvic tilt, anterior pelvic plane inclination and pelvic axial rotation. Additionally, anteversion and inclination of the acetabular cup position were determined. RESULTS: No statistically significant difference was found between the preoperative and postoperative measurements of pelvic parameters, although the change in pelvic tilt approached significance. Postoperatively, respective average values of 42.6. and 22.7. were measured for inclination and anteversion of the acetabular cup position. CONCLUSION: THA did not influence pelvic position and sagittal alignment in patients with normal preoperative pelvic parameters. A subsequent study will investigate whether corrections of pelvic parameters outside the norm in patients with OA are possible with THA

Cementless fixation in medial unicompartmental knee arthroplasty: a systematic review

Purpose The aim of this study was to evaluate clinical outcome, failures, implant survival and complications encountered with cementless fixation in unicompartmental knee arthroplasty (UKA). Methods A systematic review of the literature on cementless fixation in UKA was performed according to the PRISMA guidelines. The following database were comprehensively searched: PubMed, Cochrane, MEDLINE, CINAHL, Embase, and Google Scholar. The keywords “unicompartmental”, “unicondylar”, “partial knee arthroplasty”, and “UKA” were combined with each of the keyword “uncemented”, “cementless” and “survival”, “complications”, “outcome”. The following data were extracted: demographics, clinical outcome, details of failures and revisions, cumulative survival and complications encountered. The risk of bias of each study was estimated with the MINORS score and a further scoring system based on the presence of the primary outcomes. Results From a cohort of 63 studies identified using the above methodology, ten papers (1199 knees) were included in the final review. The mean follow-up ranged from 2 to 11 years (median 5 years). The 5-year survival ranged from 90% to 99%, and the 10-year survival from 92 to 97%. There were 48 revisions with an overall revision rate of 0.8 per 100 observed component years. The most common cause of failure was progression of osteoarthritis in the retained compartment (0.9%). The cumulative incidence of complications and revisions was comparable to that reported in similar studies on cemented UKAs. The advantages of cementless fixation include faster surgical time, avoidance of cementation errors and lower incidence of radiolucent lines. Conclusions Cementless fixation is a safe and effective alternative to cementation in medial UKA. Clinical outcome, failures, reoperation rate and survival are similar to those reported for cemented implants with lower incidence of radiolucent lines.</p