Tissue anchor use in arthroscopic glenohumeral surgery.

Arthroscopic surgery has become the mainstay of treatment of several common glenohumeral pathologies such as tears of the rotator cuff and labrum. Arthroscopic rotator cuff and labral repair provide outcomes comparable to those achieved with traditional open techniques, with the benefits of smaller incisions and less soft-tissue disruption. Development and improvement of tissue anchors and arthroscopic instrumentation has been integral to the increased popularity of arthroscopic glenohumeral repairs. Current anchors can be categorized by design and material composition. Awareness of the advantages and limitations of these implants may influence anchor selection.

Primary total knee arthroplasty with condylar allograft and MCL reconstruction for a comminuted medial condyle fracture in an arthritic knee--a case report.

Fractures of the distal femur in the elderly are usually due to low energy ground level fall onto a flexed knee. Pre-existing osteoarthritis and juxta-articular osteopenia in this age group result in high levels of comminution and articular damage at the time of injury, which challenges the management and treatment outcome. Preservation of knee function and early weight bearing should be the objectives of management in the geriatric population. We present in this case report of an elderly patient with comminuted medial condyle fracture with arthritic changes who had primary total knee arthroplasty utilizing condylar allograft and MCL reconstruction as an alternative to internal fixation.

Bone replacement of fast-absorbing biocomposite anchors in arthroscopic shoulder labral repairs.

BACKGROUND: Newer generation biocomposite anchors are hypothesized to resorb more reliably and faster, while allowing for bone ingrowth and replacement. PURPOSE: The purposes of this study were to (1) assess anchor resorption and bone ingrowth over time, (2) identify tunnel widening or potential reactions to the implants, (3) compare imaging findings for different sites of labral repair, and (4) determine patient subjective outcomes with the use of biocomposite anchors in glenoid labral repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We enrolled 22 patients to participate in a 24-month outcomes study that included subjective and objective outcome assessments after glenoid labrum repair surgery. Magnetic resonance imaging (MRI) was performed at 6 and 12 months to identify any potential reactions to implants. Computed tomography (CT) scans were performed at 12 and 24 months to determine anchor resorption and bone ingrowth. Sixteen patients and 47 anchors were available for follow-up at 24 months. An independent, fellowship-trained musculoskeletal radiologist read the scans. Subjective outcome scores measured at 24 months postoperatively included Simple Shoulder Test, Tegner activity scale, American Shoulder and Elbow Surgeons (ASES), and University of California, Los Angeles (UCLA) shoulder scores. RESULTS: No adverse events were reported with the use of biocomposite anchors at the end of the study period. At 12 and 24 months, respectively, CT scans demonstrated that an estimated 68% and 98% of combined anchor material had been absorbed, 56% and 78% of the anchor material had been replaced by soft tissue of variable density, and 9% and 20% of total anchor volume was replaced by bone. No obvious mechanical failure of the labral repairs was detected on nonarthrogram MRI. Three of the 47 anchors showed bone cyst formation. Tunnel widening (expansion beyond tunnel diameter of 3 mm; 2.9-mm drill hole utilized) was seen in 55% of the anchors but decreased between 12 and 24 months, consistent with bone replacement. Tunnel widening was seen more in anteroinferior and posterior glenoid anchor locations (84% and 57%, respectively) than in superior labral anchors (13%). Subjective outcome scores at 24 months for ASES and UCLA shoulder scores averaged 88 and 30, respectively. All but one patient were satisfied with their outcome at 24 months. CONCLUSION: Our imaging evaluation indicates resorption of newer generation biocomposite anchors with progressive bone replacement at 12 and 24 months while maintaining acceptable subjective outcomes.

The reaction of bone to tumor growth from human breast cancer cells in a rat spine single metastasis model.

STUDY DESIGN: In vivo experiments to develop a rat spine single metastasis model by using human breast cancer cells. OBJECTIVE: To study the survival and tumorigenesis of the human breast cancer cells after transplantation to vertebral body (VB) by intraosseous injection as a model for therapeutic studies of spine metastatic tumor. SUMMARY OF BACKGROUND DATA: VBs are the most common bones involved in the metastases of breast cancer. To develop experimental therapeutics requires an appropriate animal model. Moreover, it is also important to establish accurate and sensitive detection methods for the evaluation. METHODS: MDA-MB-231 human breast cancer cells were injected into 3-week-old female athymic rats. The tumorigenesis was assayed with quantitative in vivo bioluminescence (IVIS), microcomputed tomography (micro-CT), quantitative CT (qCT), micro position emission tomography (micro-PET), and histologic studies. RESULTS: A spine single metastasis model of human breast cancer was successfully developed in rats. The IVIS signal intensity from the cancer cells increased after 2 weeks. Signal from the tumor in spine can be detected by micro-PET at day 1. The signal intensity decreased after 1 week and then recovered and continually increased afterwards. Bone destruction was demonstrated in the qCT and micro-CT images. However, both qCT and micro-CT found that the bone density in the cancer cell-injected VB increased before the appearance of osteolysis. The growth of tumor and the reaction of bone in the VB were observed simultaneously by histology. CONCLUSION: A spine single metastasis model was developed by injection of human breast cancer cells into the VB of athymic rats. This is the first report of quantitative evaluation with micro-PET in a spine metastasis model. In addition, the detection of osteogenesis after the introduction of MDA-MB-231 cells in vivo is a novel observation.

Therapeutic effects of adenovirus-mediated growth and differentiation factor-5 in a mice disc degeneration model induced by annulus needle puncture.

BACKGROUND CONTEXT: The therapeutic strategies that have thus far been used for the treatment of intervertebral disc degeneration (IDD) have focused on relieving the symptoms, although reversal of the degeneration remains an important challenge for the effective treatment of IDD. Growth and differentiation factor-5 (GDF5), of which deficiency leads to early disc degeneration changes, has the potential to increase proliferation of disc cells and expression of extracellular matrix proteins. PURPOSE: The purpose of the study was to develop a lumbar disc degeneration model in mice and determine the effect of adenoviral GDF5 gene therapy. STUDY DESIGN: The study design was to compare the degeneration changes of discs punctured by different-size needles to develop a mice lumbar disc degeneration model and to evaluate the effects of in vivo gene therapy for the mice disc degeneration model by an adenoviral vector carrying GDF5 gene. METHODS: A lumbar disc degeneration model was developed by needle punctures to the discs in Balb/c mice. Afterward, a gene therapy treatment to disc degeneration was evaluated. Two of the mice lumbar discs were randomly chosen to be punctured by a 30-gauge needle and then injected with adenovirus that had been engineered to express either the luciferase gene (Ad-Luc) or the GDF5 gene (Ad-GDF5). Animals were analyzed by bioluminescent imaging, radiographic, and magnetic resonance imaging (MRI) scanning, then sacrificed at 1, 2, 4, or 8 weeks after operation, and subjected to histological and biochemical assays. RESULTS: By the detection of T2-weighted MRI scanning and histological study, the degeneration was found in all of the discs punctured by different-size needles. But the development of the degeneration in the discs injured by the 30-gauge needle was more reliable and moderate compared with that in other groups. The detection of luciferase activity by bioluminescent imaging revealed that adenovirus survived and the introduced genes were expressed over 6 weeks after injection. There were no T2-weighted MRI signals in the mice injected with either Ad-Luc or Ad-GDF5 up to 4 weeks after operation. At 6 and 8 weeks, T2-weighted signals were detected in the Ad-GDF5 group but none in the Ad-Luc control group. The percent disc height index (%DHI) was significantly decreased (approximately 20%) by 1 week after injury in both groups, indicating the development of disc degeneration. At 2 weeks, the %DHI in the mice injected with Ad-GDF5 increased significantly compared with that of the mice injected with Ad-Luc; the increase was sustained for the rest of the experiment period. The disc histology treated with Ad-GDF5 was improved compared with that in the control group. Glycosaminoglycan (GAG) levels were significantly decreased in the Ad-Luc injection group since 2 weeks after injury, and the DNA content had diminished by 4 weeks after the operation. In contrast, in the discs injected with Ad-GDF5, there was no decrease in the GAG and DNA levels after injury throughout the 8-week treatment period. CONCLUSIONS: Disc degeneration animal model can be developed by using needle puncture to the discs in mice. The adenovirus is an effective vehicle for gene delivery with rapid and prolonged expression of target protein and resulting improvement in markers of disc degeneration. Ad-GDF5 gene therapy could restore the functions of injured discs and has the potential to be an effective treatment.