The Transmembrane Bax Inhibitor-1 motif (TMBIM)-containing protein family is evolutionarily conserved and has been implicated in cell death susceptibility. The only member with a mitochondrial localization is TMBIM5 (also known as GHITM or MICS1), which affects cristae organization and associates with the Parkinson’s disease-associated protein CHCHD2 in the inner mitochondrial membrane. We here used CRISPR-Cas9-mediated knockout HAP1 cells to shed further light on the function of TMBIM5 in physiology and cell death susceptibility. We found that compared to wild type, TMBIM5-knockout cells were smaller and had a slower proliferation rate. In these cells, mitochondria were more fragmented with a vacuolar cristae structure. In addition, the mitochondrial membrane potential was reduced and respiration was attenuated, leading to a reduced mitochondrial ATP generation. TMBIM5 did not associate with Mic10 and Mic60, which are proteins of the mitochondrial contact site and cristae organizing system (MICOS), nor did TMBIM5 knockout affect their expression levels. TMBIM5-knockout cells were more sensitive to apoptosis elicited by staurosporine and BH3 mimetic inhibitors of Bcl-2 and Bcl-XL. An unbiased proteomic comparison identified a dramatic downregulation of proteins involved in the mitochondrial protein synthesis machinery in TMBIM5-knockout cells. We conclude that TMBIM5 is important to maintain the mitochondrial structure and function possibly through the control of mitochondrial biogenesis.

Lateralization and distalization in reverse shoulder arthroplasty (RSA) can be measured on anteroposterior (AP) radiographs using 2 previously described angles: lateralization shoulder angle (LSA) and distalization shoulder angle (DSA). However, these 2 angles measure global lateralization and distalization but do not allow to differentiate how much lateralization or distalization are attributable to the glenoid and the humerus. We hypothesized that new angles could allow us to separately measure glenoid vs. humeral lateralization and distalization. A more precise understanding of independent glenoid and humeral contributions to lateralization and distalization may be beneficial in subsequent clinical research. Retrospective analysis of postoperative AP radiographs of 100 patients who underwent primary RSA for cuff-tear arthropathy, massive cuff tear, or glenohumeral osteoarthritis were analyzed. The new angles that we proposed use well-known bony landmarks (the acromion, glenoid, and humerus) and the most lateral point of the glenosphere, which we termed the "glenoid pivot point" (GPP). For lateralization, we used the GPP to split LSA into 2 new angles: glenoid lateralization angle (GLA) and humeral lateralization angle (HLA). For distalization, we introduced the modified distalization shoulder angle (mDSA) that can also be split into 2 new angles: glenoid distalization angle (GDA) and humeral distalization angle (HDA). Three orthopedic surgeons measured the new angles, using the online tool Tyche. Mean values with overall and individual standard deviations as well as intraclass correlation coefficients (ICCs) were calculated. Because the angles form a triangle, the following equations can be made: LSA = GLA + HLA, and mDSA = GDA + HDA. All angles showed excellent inter- and intraobserver reliability (ICC = 0.92-0.97) with low means of individual standard deviations that indicate a precision of 2° for each angle. Use of the most lateral part of the glenosphere (termed glenoid pivot point) allows us to separately measure glenoid vs. humeral lateralization and distalization. The 4 new angles (HLA, GLA, GDA, HDA) described in the present study can be used on true AP radiographs, routinely obtained after shoulder replacement, and the measured angles may be used with all types of reverse prostheses available.

Aims: Optimal glenoid positioning in reverse shoulder arthroplasty (RSA) is crucial to provide impingement-free range of motion (ROM). Lateralization and inclination correction are not yet systematically used. Using planning software, we simulated the most used glenoid implant positions. The primary goal was to determine the configuration that delivers the best theoretical impingement-free ROM.Methods: With the use of a 3D planning software (Blueprint) for RSA, 41 shoulders in 41 consecutive patients (17 males and 24 females; means age 73 years (SD 7)) undergoing RSA were planned. For the same anteroposterior positioning and retroversion of the glenoid implant, four different glenoid baseplate configurations were used on each shoulder to compare ROM: 1) no correction of the RSA angle and no lateralization (C-L-); 2) correction of the RSA angle with medialization by inferior reaming (C+M+); 3) correction of the RSA angle without lateralization by superior compensation (C+L-); and 4) correction of the RSA angle and additional lateralization (C+L+). The same humeral inlay implant and positioning were used on the humeral side for the four different glenoid configurations with a 3 mm symmetric 135° inclined polyethylene liner.Results: The configuration with lateralization and correction of the RSA angle (C+L+) led to better ROM in flexion, extension, adduction, and external rotation (p ≤ 0.001). Only internal rotation was not significantly different between groups (p = 0.388). The configuration where correction of the inclination was done by medialization (C+M+) led to the worst ROM in adduction, extension, abduction, flexion, and external rotation of the shoulder.Conclusion: Our software study shows that, when using a 135° inlay reversed humeral implant, correcting glenoid inclination (RSA angle 0°) and lateralizing the glenoid component by using an angled bony or metallic augment of 8 to 10 mm provides optimal impingement-free ROM.Cite this article: Bone Jt Open 2024;5(10):851–857.

Glenoid erosion is the major cause for revision in shoulder hemiarthroplasty (HA). Our purpose was to assess survival and outcomes of HA with pyrocarbon head (HA-PYC) in a large series of young and high-demand patients, and to identify risk factors for postoperative revision surgery. 96 consecutive patients (103 shoulders) who underwent HA-PYC for primary (n = 44) or secondary osteoarthritis (OA; n = 59) were prospectively followed and reviewed clinically with 2-year minimum follow-up. The mean age at surgery was 56 ± 8 years; 79 patients were still working and 59 still involved in sports. The Tornier pyrocarbon humeral head was used with a convertible press-fit stem (Ascend Flex, Tornier-Stryker). In biconcave (B2 and B3) glenoid erosion, double reaming (corrective and concentric) was performed. The quality of humeral reconstruction was assessed on postoperative computed tomography scans according to the circle method. The increase of glenoid erosion was assessed by comparing immediate and last follow-up radiographs according to the Sperling classification. The mean follow-up was 5.6 years (2-10 years). The revision-free rate was 94% at 5 years and 89% at 10 years. Seven shoulders required revision surgery with conversion to reverse total shoulder arthroplasty (n = 6) or anatomic total shoulder arthroplasty (n = 1); mean time to revision was 31 months (range 10-85 months). There was no difference in outcomes and prosthesis survival between primary and secondary OA, and between shoulders with and without glenoid reaming. Increase of glenoid erosion over time was associated with significant increased pain, decreased shoulder function and subjective results, and a higher risk of revision (72% vs. 97%, P = .002). Nonanatomic humeral reconstruction with oversizing of the pyrocarbon head occurred in 24% and was associated with significantly higher rates of increased glenoid erosion (odds ratio 3.46, 95% confidence interval 1.13-10.55, P = .0295) and revision surgery (25% vs. 1.3%, P < . 001). Overall, 88% (91 of 103) of the patients were satisfied with the procedure; 92% (73 of 79) could return to work and 93% (55 of 59) to sport practice. The use of HA-PYC for the treatment of shoulder OA in young and active patients improves shoulder function and provides low risks of glenoid erosion and revision surgery at 2- to 10-year follow-up. Pyrocarbon arthroplasty does not protect from glenoid erosion in case of nonanatomic humeral reconstruction because of oversizing of the humeral head. "Double reaming" (corrective and concentric) of the glenoid can be performed safely in case of biconcave erosion (type B2 or B3) as it does not show any adverse effect on prosthesis survival and functional results.

Background: Bucket-handle meniscal tears are mostly treated arthroscopically. However, there is no clear evidence as to whether the time to surgery impacts the outcome and whether or not lesions should be treated urgently. Methods: Sixty patients were interviewed about the current status of their knee with a mean follow-up of 6.1 years (SD = 3.5). Forty-one patients underwent meniscus repair, and fifteen patients received partial resections. The primary outcome was the rate of reoperation after meniscus repair. Secondary outcomes were pain at rest and during exercise, return to sports, and Tegner and Lysholm scores. Results: The average time to surgery was 14.4 days, with no significant impact of surgical timing on the rate of reoperation. Furthermore, no significant differences were found in pain levels, return to sports, or Tegner and Lysholm scores based on the timing of surgery. Conclusions: In our cohort, the time to surgery was not a prognostic factor for the reoperation rate or postoperative outcome in repairing bucket-handle meniscal tears. Therefore, arthroscopic repair should not be performed in an emergency setting but conducted after careful planning by experienced arthroscopy surgeons. Regarding the return to sports, postoperative factors such as rehabilitation protocols or surgical techniques could be more important than the time to surgery.

Zusammenfassung: Hintergrund: Proximale Femurfrakturen stellen mit mehr als 20 % die häufigste Frakturentität in Deutschland dar. Gleichzeitig müssen proximale Femurfrakturen aufgrund eines Beschlusses des Gemeinsamen Bundesausschusses (G-BA) von 2019 innerhalb von 24 h operiert werden. Um einen subjektiv wahrgenommen Anstieg des Arbeitspensums in der Unfallchirurgie an einem überregionalen Traumazentrum (ÜTZ) zu quantifizieren, wurde die Anzahl der proximalen Femurfrakturen von 2016 bis 2022 analysiert. Proximale Femurfrakturen wurden hierfür aufgrund ihrer Häufigkeit und der Homogenität in der Behandlung ausgewählt. Methode: Anhand der ICD-10-Diagnosen wurden alle operierten proximalen Femurfrakturen der Jahre 2016–2022 mitsamt der Postleitzahl an einem ÜTZ ausgewertet. Ergebnis: Die Anzahl der operativ versorgten proximalen Femurfrakturen ist von 2016 bis 2022 um 100 % gestiegen. Der größte Anstieg wurde mit 60 % von 2020 bis 2022 verzeichnet. Gleichzeitig kam es zu einer deutlichen Vergrößerung des Einzugsradius der versorgten Patienten. Schlussfolgerung: Am untersuchten ÜTZ kam es im (inter-)nationalen Vergleich zu einem überproportionalen Anstieg der versorgten proximalen Femurfrakturen. Der Anstieg des Einzugsradius und die Zunahme der versorgten Patienten im Stadtgebiet zeigen, dass immer weniger Krankenhäuser an der Notfallversorgung teilnehmen. Mögliche Erklärungen sind ein Ressourcenmangel, verstärkt durch die COVID-19-Pandemie und den Fachkräftemangel, Schnittstellenproblematiken an Bundesländergrenzen oder strenge Vorgaben des G‑BA in der Versorgung der proximalen Femurfrakturen. Es ist bei gleich gebliebener Infrastruktur im untersuchten ÜTZ von einem deutlich erhöhten Arbeitsaufkommen für alle beteiligten Professionen auszugehen. Graphic