Return to Sports and Clinical Results After All-Arthroscopic Biceps Tenodesis Using a 2.7-mm Knotless PEEK Suture Anchor

Background

The long head of the biceps tendon (LHBT) is a well-known source of pain in the shoulder, especially in active patients.

Purpose

To evaluate the outcomes and return-to-sports rate after all-arthroscopic suprapectoral tenodesis of the LHBT using a small knotless anchor.

Study Design

Case series; Level of evidence, 4.

Methods

In this retrospective study, 27 patients-who underwent all-arthroscopic tenodesis of the LHBT using a 2.7-mm knotless polyether ether ketone anchor-were evaluated. Sports activities, the return-to-sports rate, and other sports-related parameters (eg, pain during sports, level of sports) were examined. Sports-related data, the Constant score with isometric force (at 90° of abduction in the scapular plane), the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST) score, the visual analog scale (VAS) score for satisfaction, range of motion, and the presence of a Popeye deformity were assessed at a mean follow-up of 15.3 ± 8.7 months. The data were initially analyzed using descriptive statistics.

Results

The postoperative ASES, Constant, and SST scores were 81.61, 85.74 and 8.85, respectively. Of the 27 patients, 4 patients (14.8%) showed a Popeye deformity. Preoperatively, 25 patients (92.6%) participated regularly in some type of sports activity. All 25 patients (100.0%) were able to return to sports activities after surgery. 24 (96.0%) returned to the same level preoperatively, with 88.0% (22/25) within 6 months. Patient satisfaction with the outcome was high (VAS score: 2.15 ± 2.78). Neither bicipital groove pain nor cramping was reported. There were no signs of osteolytic bone around the anchor or a fracture of the humeral bone.

Conclusion

Our clinical results after using a 2.7-mm knotless anchor for LHBT tenodesis as well as the return-to-sports rate were satisfying. Using an anchor this size can lower the risk of cortical bone damage and therefore the risk of fractures of the humeral head while still enabling patients to perform at a high level.

The Value of Computed Tomography-Based Planning in Shoulder Arthroplasty Compared to Intra-/Interobserver Reliability of X-ray Planning

Background: Reversed total shoulder arthroplasty (RTSA) is an established surgery for many pathologies of the shoulder and the demand continues to rise with an aging population. Preoperative planning is mandatory to support the surgeon's understanding of the patient's individual anatomy and, therefore, is crucial for the patient's outcome. Methods: In this observational study, we identified 30 patients who underwent RTSA with two- and three-dimensional preoperative planning. Each patient underwent new two-dimensional planning from a medical student and an orthopedic resident as well as through a mid-volume and high-volume shoulder surgeon, which was repeated after a minimum of 4 weeks. The intra- and interobserver reliability was then analyzed and compared to the 3D planning and the implanted prosthesis. The evaluated parameters were the size of the pegged glenoid baseplate, glenosphere, and humeral short stem. Results: The inter-rater reliability showed higher deviations in all four raters compared to the 3D planning of the base plate, glenosphere, and shaft. The intra-rater reliability showed a better correlation in more experienced raters, especially in the planning of the shaft. Conclusions: Our study shows that 3D planning is more accurate than traditional planning on plain X-rays, despite experienced shoulder surgeons showing better results in 2D planning than inexperienced ones.

Recreational athletes during downhill-mountain biking (DMB) show high incidence of upper extremity fractures in combination with soft-tissue injuries

Downhill-mountain biking (DMB) is a high-risk sport and often leads to several injuries, especially in non-professional athletes. We retrospectively analyzed the most common injuries and profiled the injury mechanism. Until now, there is no such analysis of injuries by non-professional mountain bike athletes. We collected patient data from patients who suffered from an injury during DMB. The inclusion criteria were (1) injury during the summer season of 2020 and 2021, (2) injury during off-road and downhill mountain bike sports activity, and (3) treatment at the Department of Traumatology of the Klinik Diakonissen Schladming. Patient data was analyzed regarding the type of injury, location of the injury, patient age and gender of the patients. Most patients with injury are at the age of 26-35. Second most are between 36 and 71 years old. The type of injury differs between age and gender. Mostly upper-extremity injuries occur with a high probability of shoulder injuries. In the elderly patients, we found additional injuries of the thorax and chest. To conclude, most common types of injuries are soft-tissue injuries, often in combination with fractures. The risk for injuries is higher for recreational athletes with different injury characteristics than professional athletes.

Sciatic Nerve Compression after a Chronic Proximal Hamstring Tear: A Report of Two Cases and a Narrative Review of the Literature

Proximal hamstring tears are among the most common injuries afflicting athletes and middle-aged individuals. Sciatic nerve compression after a proximal hamstring injury, which can occur due to scar formation and subsequent irritation or compression of the nerve, is an infrequent but severe complication with few cases documented in the literature. No evidence is available about the optimal treatment for sciatic nerve symptoms after proximal hamstring injuries. In this case report, we present two cases involving patients primarily treated conservatively at another institution after suffering from a proximal hamstring injury and developing sciatic nerve symptoms over the course of a few months. Both were treated with open neurolysis at our institution without reattachment of the ruptured muscles to the ischial tuberosity due to the chronicity of the injuries. Both patients exhibited neurological symptoms over two years, which recovered after surgery. These two cases show that neurolysis of the sciatic nerve without reattachment of the proximal hamstring muscles is an applicable option for the treatment of chronic proximal hamstring tears with sciatic nerve compression. Further studies will be needed to validate this hypothesis.

Learning Curve for Short-Stem Total HIP Arthroplasty through an Anterolateral Approach

Background and Objectives: Short-stem total hip arthroplasty has become increasingly popular in recent years. While many studies have shown excellent clinical and radiological results, very little is known about the learning curve for short-stem total hip arthroplasty through an anterolateral approach. Therefore, the aim of this study was to determine the learning curve for short-stem total hip arthroplasty among five residents in training. Materials and Methods: We performed retrospective data analysis of the first 30 cases of five randomly selected residents (n = 150 cases) with no experience before the index surgery. All patients were comparable, and several surgical parameters and radiological outcomes were analyzed. Results: The only surgical parameter with a significant improvement was the surgical time (p = 0.025). The changes in other surgical parameters and radiological outcomes showed no significant changes; only trends can be derived. As a result, the correlation between surgical time, blood loss, length of stay, and incision/suture time can also be seen. Only two of the five residents showed significant improvements in all examined surgical parameters. Conclusions: There are individual differences among the first 30 cases of the five residents. Some improved their surgical skills faster than others. It could be assumed that they assimilated their surgical skills after more surgeries. A further study with more than 30 cases of the five surgeons could provide more information on that assumption.

Anti-OX40L alone or in combination with anti-CD40L and CTLA4Ig does not inhibit the humoral and cellular response to a major grass pollen allergen

BACKGROUND

IgE-mediated allergy is a common disease characterized by a harmful immune response towards otherwise harmless environmental antigens. Induction of specific immunological non-responsiveness towards allergens would be a desirable goal. Blockade of costimulatory pathways is a promising strategy to modulate the immune response in an antigen-specific manner. Recently, OX40 (CD134) was identified as a costimulatory receptor important in Th2-mediated immune responses. Moreover, synergy between OX40 blockade and 'conventional' costimulation blockade (anti-CD40L, CTLA4Ig) was observed in models of alloimmunity.

OBJECTIVE

We investigated the potential of interfering with OX40 alone or in combination with CD40/CD28 signals to influence the allergic immune response.

METHODS

The OX40 pathway was investigated in an established murine model of IgE-mediated allergy where BALB/c mice are repeatedly immunized with the clinically relevant grass pollen allergen Phl p 5. Groups were treated with combinations of anti-OX40L, CTLA4Ig and anti-CD40L. In selected mice, Tregs were depleted with anti-CD25.

RESULTS

Blockade of OX40L alone at the time of first or second immunization did not modulate the allergic response on the humoral or effector cell levels but slightly on T cell responses. Administration of a combination of anti-CD40L/CTLA4Ig delayed the allergic immune response, but antibody production could not be inhibited after repeated immunization even though the allergen-specific T cell response was suppressed in the long run. Notably, additional blockade of OX40L had no detectable supplementary effect. Immunomodulation partly involved regulatory T cells as depletion of CD25(+) cells led to restored T cell proliferation.

CONCLUSIONS AND CLINICAL RELEVANCE

Collectively, our data provide evidence that the allergic immune response towards Phl p 5 is independent of OX40L, although reduction on T cell responses and slightly on the asthmatic phenotype was detectable. Besides, no relevant synergistic effect of OX40L blockade in addition to CD40L/CD28 blockade could be detected. Thus, the therapeutic potential of OX40L blockade for IgE-mediated allergy appears to be ineffective in this setting.

Rapamycin and CTLA4Ig synergize to induce stable mixed chimerism without the need for CD40 blockade

The mixed chimerism approach achieves donor-specific tolerance in organ transplantation, but clinical use is inhibited by the toxicities of current bone marrow (BM) transplantation (BMT) protocols. Blocking the CD40:CD154 pathway with anti-CD154 monoclonal antibodies (mAbs) is exceptionally potent in inducing mixed chimerism, but these mAbs are clinically not available. Defining the roles of donor and recipient CD40 in a murine allogeneic BMT model, we show that CD4 or CD8 activation through an intact direct or CD4 T cell activation through the indirect pathway is sufficient to trigger BM rejection despite CTLA4Ig treatment. In the absence of CD4 T cells, CD8 T cell activation via the direct pathway, in contrast, leads to a state of split tolerance. Interruption of the CD40 signals in both the direct and indirect pathway of allorecognition or lack of recipient CD154 is required for the induction of chimerism and tolerance. We developed a novel BMT protocol that induces mixed chimerism and donor-specific tolerance to fully mismatched cardiac allografts relying on CD28 costimulation blockade and mTOR inhibition without targeting the CD40 pathway. Notably, MHC-mismatched/minor antigen-matched skin grafts survive indefinitely whereas fully mismatched grafts are rejected, suggesting that non-MHC antigens cause graft rejection and split tolerance.

Donor CD4 T cells trigger costimulation blockade-resistant donor bone marrow rejection through bystander activation requiring IL-6

Bone marrow (BM) transplantation under costimulation blockade induces chimerism and tolerance. Cotransplantation of donor T cells (contained in substantial numbers in mobilized peripheral blood stem cells and donor lymphocyte infusions) together with donor BM paradoxically triggers rejection of donor BM through undefined mechanisms. Here, nonmyeloablatively irradiated C57BL/6 recipients simultaneously received donor BM (BALB/c) and donor T cells under costimulation blockade (anti-CD154 and CTLA4Ig). Donor CD4, but not CD8 cells, triggered natural killer-independent donor BM rejection which was associated with increased production of IL-6, interferon gamma (IFN-γ) and IL-17A. BM rejection was prevented through neutralization of IL-6, but not of IFN-γ or IL-17A. IL-6 counteracted the antiproliferative effect of anti-CD154 in vitro. Rapamycin and anti-lymphocyte function-associated antigen 1 negated this effect of IL-6 in vitro and prevented BM rejection in vivo. Simultaneous cotransplantation of (BALB/cxB6)F1, recipient or irradiated donor CD4 cells, or late transfer of donor CD4 cells did not lead to BM rejection, whereas cotransplantation of third party CD4 cells did. Transferred donor CD4 cells became activated, rapidly underwent apoptosis and triggered activation and proliferation of recipient T cells. Collectively, these results provide evidence that donor T cells recognizing the recipient as allogeneic lead to the release of IL-6, which abolishes the effect of anti-CD154, triggering donor BM rejection through bystander activation.

Persistent molecular microchimerism induces long-term tolerance towards a clinically relevant respiratory allergen

BACKGROUND

Development of antigen-specific preventive strategies is a challenging goal in IgE-mediated allergy. We have recently shown in proof-of-concept experiments that allergy can be successfully prevented by induction of durable tolerance via molecular chimerism. Transplantation of syngeneic hematopoietic stem cells genetically modified to express the clinically relevant grass pollen allergen Phl p 5 into myeloablated recipients led to high levels of chimerism (i.e. macrochimerism) and completely abrogated Phl p 5-specific immunity despite repeated immunizations with Phl p 5.

OBJECTIVE

It was unclear, however, whether microchimerism (drastically lower levels of chimerism) would be sufficient as well which would allow development of minimally toxic tolerance protocols.

METHODS

Bone marrow cells were transduced with recombinant viruses integrating Phl p 5 to be expressed in a membrane-anchored fashion. The syngeneic modified cells were transplanted into non-myeloablated recipients that were subsequently immunized repeatedly with Phl p 5 and Bet v 1 (control). Molecular chimerism was monitored using flow cytometry and PCR. T cell, B-cell and effector-cell tolerance were assessed by allergen-specific proliferation assays, isotype levels in sera and RBL assays.

RESULTS

Here we demonstrate that transplantation of Phl p 5-expressing bone marrow cells into recipients having received non-myeloablative irradiation resulted in chimerism persisting for the length of follow-up. Chimerism levels, however, declined from transient macrochimerism levels to persistent levels of microchimerism (followed for 11 months). Notably, these chimerism levels were sufficient to induce B-cell tolerance as no Phl p 5-specific IgE and other high affinity isotypes were detectable in sera of chimeric mice. Furthermore, T-cell and effector-cell tolerance were achieved.

CONCLUSIONS AND CLINICAL RELEVANCE

Low levels of persistent molecular chimerism are sufficient to induce long-term tolerance in IgE-mediated allergy. These results suggest that it will be possible to develop minimally toxic conditioning regimens sufficient for low level engraftment of genetically modified bone marrow.