The combination of 3D printing and navigation promises improvements in surgical procedures and outcomes for complex bone tumor resection of the trunk, but its features have rarely been described in the literature. Five patients with trunk tumors were surgically treated in our institution using a combination of 3D printing and navigation. The main process includes segmentation, virtual modeling and build preparation, as well as quality assessment. Tumor resection was performed with navigated instruments. Preoperative planning supported clear margin multiplanar resections with intraoperatively adaptable real-time visualization of navigated instruments. The follow-up ranged from 2–15 months with a good functional result. The present results and the review of the current literature reflect the trend and the diverse applications of 3D printing in the medical field. 3D printing at hospital sites is often not standardized, but regulatory aspects may serve as disincentives. However, 3D printing has an increasing impact on precision medicine, and we are convinced that our process represents a valuable contribution in the context of patient-centered individual care.

Proximal junctional kyphosis (PJK), as one of the most discussed problems after corrective surgery in adolescent idiopathic scoliosis (AIS), is still not fully clarified and seems to be multifactorial. Biomechanical and a few clinical studies have shown the influence of destruction of posterior ligaments by resection of spinous processes and some parameters concerning rod contouring as risk factors for PJK. To verify these results, 192 patients with AIS and corrective surgery via a posterior approach between 2009 and 2017 were included. Radiographic parameters were analyzed preoperatively (preOP), postoperatively (postOP), and with a mean follow up (FU) of 27 months. The participants were divided into two groups (PJK group and non-PJK group). The incidence of PJK was 15.6%. Contrary to the results of biomechanical studies, we could not find any significant influence of the spinous process resection. However, the PJK group had significantly larger preOP T4–T12 kyphosis (31.1° ± 13.93° vs. 23.3° ± 14.93°, p = 0.016). Furthermore, the PJK group showed a significantly larger rod contour angle (RCA) (8.0° ± 4.44° vs. 5.9° ± 3.28°, p = 0.003) and mismatch of postOP proximal junctional angle (PJA) and RCA (3.5° ± 5.72° vs. 0.9° ± 4.86°, p = 0.010) compared to the non-PJK group. An increase in the mismatch of postOP PJA and RCA (OR = 1.14, p = 0.008) and a high RCA are risk factors for PJK and need to be focused on by surgeons.

The aim of this study was to investigate the effect of radial extracorporeal shockwave therapy (rESWT) primarily on acute lumbar back pain (aLBP), and secondarily on physical function and quality of life. This randomized, placebo-controlled, single-blinded trial with 12-week follow-up (FU) randomized 63 patients with aLBP 1:1 into two groups receiving either rESWT (intervention) or sham rESWT (placebo) with a manipulated shockwave head not delivering any shockwaves. Both, rESWT and sham procedure were carried out eight times for four weeks. Both groups received additional analgesics and physiotherapy twice a week. Primary patient-reported outcome measure (PROM) was the visual analogue scale for aLBP (VAS-LBP). Secondary PROMs included the Oswestry disability index (ODI), Roland and Morris Disability Questionnaire (RDQ), EuroQol EQ-5D-3L, and the Beck Depression Index (BDI-II). Primary endpoint was a between-arm comparison of mean changes in VAS-LBP from baseline to final FU. At randomization, there were no differences between the two groups in relation to age and PROMs. Both groups showed significant improvement in all PROMs at final FU. VAS-LBP declined by 60.7% (p < 0.001) in the intervention and by 86.4% (p < 0.001) in the sham group. The intervention group showed significantly less pain relief after 4 and 12 weeks. The EQ-5D submodality pain showed significantly inferior results for the intervention (1.5 (0.58)) compared to the sham group (1.1 (0.33)) (p < 0.014) after eight weeks. No significant intergroup differences were observed for RDQ, ODI or BDI-II. Additional rESWT alongside conventional guideline therapy in aLBP does not have any significant effects on pain intensity, physical function, or quality of life. To the best of our knowledge, this is the first study with a high level of evidence reporting the efficacy of rESWT in aLBP treatment and will be a future basis for decision-making.

Background: Rotating-hinge knee (RHK) implants are an option for knee arthroplasty in cases of instability or severe bone loss. However, the revision rate can be increased compared to unconstrained implants which mandate improvements in implant design. This study investigates a novel RHK design for total knee arthroplasty (TKA). Methods: Retrospective analysis of a single design RHK TKA (GenuX MK, Implantcast) implanted between 2015 and 2019 including 133 patients (21 primary TKA, 112 revisions). The main indication for revision TKA was second-stage reimplantation following infection. The median follow-up amounted to 30 months (IQR 22–47). Results: In total, 13% (18/133) of patients underwent revision surgery after a mean time of 1 month (IQR 0–6). The main reason for the revision was (re-) infection in 8% of patients. All revisions were performed following revision TKA and none following primary TKA. There were no revision surgeries for loosening or instability. The revision-free implant survival of 83% was (95% CI 75–91%) after five years. A higher number of previous surgeries was associated with a greater revision risk (p = 0.05). Conclusion: Revision and complex primary TKA using a single-design RHK implant results in good implant survival at mid-term follow-up although infection remains a major concern.

Proximal Junctional Kyphosis (PJK) as one of the most discussed problems after corrective surgery in adolescent idiopathic scoliosis (AIS), is still not fully clarified and seems to be multifactorial. Biome-chanical and few clinical studies have shown the influence of destruction of posterior ligaments by re-section of spinous processes and some parameters concerning rod contouring as risk factors for PJK. To verify these results 192 patients with AIS and corrective surgery via posterior approach between 2009 and 2017 were included. Radiographic parameters were analyzed preoperatively (preOP), postoperatively (postOP), and with a mean follow up (FU) of 27 months. The participants were divided into two groups (PJK group and non-PJK group). The incidence of PJK was 15.6%. Contrary to the results of biomechanical studies, we could not find any significant influence of the spinous process resection. However, the PJK group had significantly larger preOP T4-T12 kyphosis (31.1°±13.93° vs. 23.3°±14.93°, p=.016). Furthermore, the PJK group showed a significantly larger rod contour angle (RCA) (8.0°±4.44° vs. 5.9°±3.28°, p=.003) and mismatch of postOP proximal junctional angle (PJA) and RCA (3.5°±5.72° vs. 0.9°±4.86°, p=.010) compared to the non-PJK group. An increase of the mismatch of postOP PJA and RCA (OR=1.14, p=.008) and a high RCA are risk factors for PJK and need to be focused on by surgeons.

Increasing antibiotic resistance has been reported as an issue in the treatment of periprosthetic joint infection (PJI). A repeat two-stage revision for recurrent PJI is at high risk of reinfection. However, it is unclear if the microorganism profile plays a role with potentially more resistant or polymicrobial infections. This is a retrospective, single-center analysis of two-stage revisions performed between 2011 and 2017. We identified 46 patients who underwent a repeat resection arthroplasty for recurrent PJI of the same joint after a previous two-stage revision of the same joint at the same department. All microbiological findings were analyzed focusing on microbiological spectrum and resistance testing as well as the potential impact on reinfection-free survival. The most common organism found at the time of recurrent PJI were coagulase-negative Staphylococci (39%) followed by Gram-negative organisms (28%). The risk of polymicrobial infections, difficult-to-treat resistant organisms, and Gram-negative infections increased significantly. Among staphylococcal infections, there was a high percentage of methicillin-resistant species and resistance to oral antibiotics. Patients with Gram-negative organisms had a reduced infection-free survivorship, while resistant organisms were not associated with decreased survival. Patients who undergo a repeat two-stage revision for recurrent PJI have more polymicrobial and resistant organisms, although the impact on survivorship is unclear.