Meniscus Allograft Transplantation With Bone Plugs Using Knotless All-Suture Anchors and Cortical Button Suspensory Fixation

Meniscus allograft transplantation can be successful for treatment of meniscal deficiency using a number of transplant techniques. In this Technical Note, we describe a double bone plug medial meniscus allograft transplantation technique that uses knotless all-suture anchors with cortical-button suspensory fixation. This technique maintains the reported advantages for bone-plug fixation while mitigating the risk for meniscal root damage, facilitating easier bone plug insertion and seating, expanding tensioning capabilities, and preventing soft-tissue irritation from suture knot stacks.

Fractures and Dislocations on the Playing Field: Which Are Emergent and What to Do?

High-energy injuries, including fractures and dislocations, are occurring with increasing frequency in athletic competitions with the increasing size and speed of players. Common fractures and dislocations will be discussed in this article. We will evaluate emergent versus routine injuries and discuss appropriate treatment at the athletic venue. Fractures that can be seen with athletic activities include cervical spine; knee osteochondral fractures; tibia, ankle, and clavicle. Dislocations that will be considered include knee, patella, hip, shoulder, sternoclavicular joint, and proximal interphalangeal joint of the finger. These injuries vary significantly both in severity and in the emergent nature of the injury.

Effects of Caffeine on Intervertebral Disc Cell Viability in a Whole Organ Culture Model

STUDY DESIGN

Controlled laboratory study.

OBJECTIVE

To investigate the impact of exposure to physiologically relevant caffeine concentrations on intervertebral disc (IVD) cell viability and extracellular matrix composition (ECM) in a whole organ culture model as potential contributing mechanisms in development and progression of IVD disorders in humans. Primary outcome measures were IVD viable cell density (VCD) and ECM composition.

METHODS

A total of 190 IVD whole organ explants from tails of 16 skeletally mature rats-consisting of cranial body half, endplate, IVD, endplate, and caudal body half-were harvested. IVD explants were randomly assigned to 1 of 2 groups: uninjured (n = 90) or injured (20G needle disc puncture/aspiration method, n = 100). Explants from each group were randomly assigned to 1 of 3 treatment groups: low caffeine (LCAF: 5 mg/L), moderate caffeine (MCAF: 10 mg/L), and high caffeine (HCAF: 15 mg/L) concentrations.

RESULTS

Cell viability was significantly higher in the low-caffeine group compared with the high-caffeine group at day 7 (P = .037) and in the low-caffeine group compared with the medium- and high-caffeine groups at day 21 (P ≤ .004). Analysis of ECM showed that all uninjured and control groups had significantly higher (P < .05) glycosaminoglycan concentrations compared with all injured groups. Furthermore, we observed a temporal, downward trend in proteoglycan to collagen ratio for the caffeine groups.

CONCLUSIONS

Caffeine intake may be a risk factor for IVD degeneration, especially in conjunction with disc injury. Mechanisms for caffeine associated disc degeneration may involve cell and ECM, and further studies should elucidate mechanistic pathways and potential benefits for caffeine restriction.

Double-Bundle Posterior Cruciate Ligament Reconstruction

The optimal surgical technique for posterior cruciate ligament (PCL) reconstruction is a topic of debate among knee surgeons. There are many variables to consider including graft selection, graft fixation method, and single- versus double-bundle reconstruction. While there is a need for ongoing research to elucidate which technique yields the best results, this article discusses recent literature on the topic of single- versus double-bundle PCL reconstruction as well as the senior author's preferred reconstruction method.

Fresh Osteochondral Allograft Transplants in the Knee: Bipolar and Beyond

Knee patients who have sustained chondral and osteochondral lesions suffer from debilitating pain, which can ultimately lead to posttraumatic osteoarthritis and whole-joint disease. Older, nonactive patients are traditionally steered toward total knee arthroplasty (TKA), but younger, active patients are not good candidates for TKA based on implant longevity, complications, morbidity, and risk for revision, such that treatment strategies at restoring missing hyaline cartilage and bone are highly desired for this patient population. Over the past four decades, fresh osteochondral allograft (OCA) transplantation has been developed as a treatment method for large (> 2.5 cm²) focal full-thickness articular cartilage lesions. This article documents our own institutional OCA journey since 2016 through enhanced graft preservation techniques (the Missouri Osteochondral Preservation System, or MOPS), technical improvements in surgical techniques, use of bone marrow aspirate concentrate, bioabsorbable pins and nails, and prescribed and monitored patient-specific rehabilitation protocols. Further follow-up with documentation of long-term outcomes will provide insight for continued optimization for future applications for OCA transplantation, potentially including a broader spectrum of patients appropriate for this treatment. Ongoing translational research is necessary to blaze the trail in further optimizing this treatment option for patients.

Canine models of spine disorders

Neck and low back pain are common among the adult human population and impose large social and economic burdens on health care and quality of life. Spine-related disorders are also significant health concerns for canine companions with etiopathogeneses, clinical presentations, and diagnostic and therapeutic options that are very similar to their human counterparts. Historically, induced and spontaneous pathology in laboratory rodents, dogs, sheep, goats, pigs, and nonhuman primates have been used for study of human spine disorders. While each of these can serve as useful preclinical models, they all have inherent limitations. Spontaneously occurring spine disorders in dogs provide highly translatable data that overcome many of the limitations of other models and have the added benefit of contributing to veterinary healthcare as well. For this scoping review, peer-reviewed manuscripts were selected from PubMed and Google Scholar searches using keywords: "intervertebral disc," "intervertebral disc degeneration," "biomarkers," "histopathology," "canine," and "mechanism." Additional keywords such as "injury," "induced model," and "nucleus degeneration" were used to further narrow inclusion. The objectives of this review were to (a) outline similarities in key features of spine disorders between dogs and humans; (b) describe relevant canine models; and (c) highlight the applicability of these models for advancing translational research and clinical application for mechanisms of disease, diagnosis, prognosis, prevention, and treatment, with a focus on intervertebral disc degeneration. Best current evidence suggests that dogs share important anatomical, physiological, histological, and molecular components of spinal disorders in humans, such that induced and spontaneous canine models can be very effective for translational research. Taken together, the peer-reviewed literature supports numerous advantages for use of canine models for study of disorders of the spine when the potential limitations and challenges are addressed.

Sterility of 3D-Printed Orthopedic Implants Using Fused Deposition Modeling

The use of 3-dimensional (3D) printing in orthopedics is developing rapidly and impacting the areas of preoperative planning, surgical guides, and simulation. As this technology continues to improve, the greatest impact of 3D printing may be in low- and middle-income countries where surgical items are in short supply. This study investigated sterility of 3D-printed ankle fracture fixation plates and cortical screws. The hypothesis was that the process of heated extrusion in fused deposition modeling printing would create sterile prints in a timely fashion that would not require postproduction sterilization. A free computer-assisted design program was used to design the implant models. One control group and 8 study groups were printed. Print construct, orientation, size, and postproduction sterilization differed among the groups. Sterility was assessed using thioglycollate broth cultures at 24 hours, 48 hours, and 7 days. Positive growth was speciated for aerobic and anaerobic bacteria. Print time and failed prints were recorded. Control samples were 100% positive for bacterial growth. All test samples remained sterile at all time points (100%). Speciation of control samples was obtained, and Staphylococcus was the most common species. Print times varied; however, no print time exceeded 6.75 minutes. Eighteen prints (17%) failed in the printing process. These findings demonstrate an intrinsic sterilization process associated with fused deposition modeling 3D printing and indicate the feasibility of 3D-printed surgical implants and equipment for orthopedic applications. With future research, 3D-printed implants may be a treatment modality to assist orthopedic surgeons in low- and middle-income countries. [Orthopedics. 2020; 43(1): 46-51.].

Direct Visualization of Suspensory Fixation Deployment in Knee Ligament Reconstructions Without Fluoroscopic Imaging

The authors describe a technique for visualizing the deployment of femoral suspensory fixation during ligament reconstructions that avoids the need for intraoperative fluoroscopic radiographs. Many surgeons currently use intraoperative fluoroscopic radiographs to confirm satisfactory deployment of the suspensory button on the femur; however, this technique involves prolonged surgical time, additional costs, and radiation exposure to the surgical team and patient. The authors' technique uses novel leg and camera positioning to allow for direct visualization of the button deployment. This technique can greatly improve operating room efficiency, save money, and decrease radiation exposure during surgery. [Orthopedics. 2018; 41(4):e587-e590.].

High Tibial Osteotomy following Biologic Replacement of the Knee

Biologic unicondylar replacement with fresh osteoarticular allografts of the femoral condyle and tibial plateau plus a meniscus transplant provides an option for young or active patients with severe articular cartilage loss. The timing of osteotomy procedures to correct malalignment either before, concurrent, or after allograft implantation has become an area of research interest. Concurrent osteotomies and allograft transplantation have become increasingly popular due to the decreased patient morbidity from multiple surgeries that require a period of toe-touch weight bearing (TTWB) postoperatively. We discuss here our techniques for correcting malalignment, which concurrently repair major bipolar knee lesions while transplanting the meniscus. We prefer to perform a simultaneous biologic unicondylar replacement with an osteotomy, if needed. Weight bearing alignment radiographs should be obtained 6 weeks following surgery to confirm the intraoperative findings that were obtained using fluoroscopy and the alignment rod. If malalignment persists and the biologic grafts are overloaded, a staged osteotomy should be performed as soon as possible.

Repair or Reconstruction in Acute Posterolateral Instability of the Knee: Decision Making and Surgical Technique Introduction

Complex knee injury surgeons must frequently decide whether to repair or reconstruct an acute posterolateral corner (PLC) injury. If repair is not feasible or fails, reconstruction is often necessary. Several studies have found that reconstruction has better outcomes and lower failure rates. Careful studies of the anatomy of the corner have led to the development of "two-tailed" reconstruction techniques which are becoming widely used in the field. Repair should not be completely disregarded as there are times when it is necessary, especially when no donor allograft tissue is readily available or when aggressive postoperative rehabilitation will not be performed. Optimally, if the patient has high quality tissue available for repair, it is best to combine reconstruction with repair. The authors have developed a new PLC reconstruction technique which applies the functional anatomy that has been increasingly defined. We detail these methods here, which include the use of cortical button suspensory fixation and interference screw fixation of allografts in sockets. This allows for individual and sequential intraoperative tensioning of the grafts to obtain optimal knee stability and motion.

Development of a whole organ culture model for intervertebral disc disease

Background/Objective

Whole organ in vitro intervertebral disc models have been associated with poor maintenance of cell viability. No previous studies have used a rotating wall vessel bioreactor for intervertebral disc explants culture. The purpose of this study was to develop and validate an in vitro model for the assessment of biological and biomechanical measures of intervertebral disc health and disease.

Methods

To this end, endplate-intervertebral disc-endplate whole organ explants were harvested from the tails of rats. For the injured group, the annulus fibrosus was penetrated with a 20G needle to the nucleus pulposus and aspirated. Explants were cultured in a rotating wall vessel bioreactor for 14 days.

Results

Cell viability and histologic assessments were performed at Day 0, Day 1, Day 7, and Day 14. Compressive mechanical properties of the intervertebral disc were assessed at Day 0 and Day 14. In the annulus fibrosus and nucleus pulposus cells, the uninjured group maintained high viability through 14 days of culture, whereas cell viability in annulus fibrosus and nucleus pulposus of the injured intervertebral discs was markedly lower at Day 7 and Day 14. Histologically, the uninjured intervertebral discs maintained cell viability and tissue morphology and architecture through 14 days, whereas the injured intervertebral discs showed areas of cell death, loss of extracellular matrix integrity, and architecture by Day 14. Stiffness values for uninjured intervertebral discs were similar at Day 0 and Day 14, whereas the stiffness for the injured intervertebral discs was approximately 2.5 times greater at Day 14.

Conclusion

These results suggest that whole organ intervertebral discs explants can be successfully cultured in a rotating wall vessel bioreactor to maintain cell viability and tissue architecture in both annulus fibrosus and nucleus pulposus for at least 14 days. In addition, the injury used produced pathologic changes consistent with those seen in degenerative intervertebral disc disease in humans. This model will permit further study into potential future treatments and other mechanisms of addressing intervertebral disc disease.