A Novel, Minimally-Invasive Approach to Repair Degenerative Disk Disease in an Ovine Model Using Injectable Polymethyl-Methacrylate and Bovine Collagen (PMMA/BC)

Novel Biomarkers of Health and Degeneration in Human Intervertebral Discs: In-depth Proteomic Analysis of Collagen Framework of Fetal, Healthy, Scoliotic, Degenerate, and Herniated Discs

STUDY DESIGN

Profiling proteins expressed in the nucleus pulposus (NP) of intervertebral discs (IVDs) in five different biological states.

PURPOSE

To evaluate the molecular complexity of the collagen (COL) framework and its role in the health and disease of human IVDs.

OVERVIEW OF LITERATURE

Changes in COL composition have been linked to degenerative disk disease (DDD). Despite the fact that humans have 28 different types of COLs, most of the literature focuses solely on COL-1 and COL-2. This study used high-end proteomic technology to examine the entire COL composition of the human IVD across fetal (developmental-FD), normal (healthy-ND), scoliotic (early degeneration-SD), herniated (degenerate-DH), and degenerated (DD) disk phenotypes.

METHODS

Forty NP tissues were snap-frozen in liquid nitrogen (-196°C) immediately before being subjected to proteomic and bioinformatic analyses from five different disk phenotypes (eight each).

RESULTS

Tandem mass spectrometric analysis revealed a total of 1,050 proteins in FDs, 1,809 in ND, 1,487 in SD, 1,859 in DH, and 1,538 in the DD group. Of 28 major collagens reported in the human body, this study identified 24 different collagens with 34 subtypes in NP. Fibril-forming collagens (COL-1, 2, and 11A1) and fibril-associated collagens with interrupted triple helices (COL-9A1, 12A1, and 14A1) were abundantly expressed in FDs, representing their role in the development of NP. Multiplexin (COL-15), a hybrid proteoglycan-collagen molecule, was discovered only in FDs. Degeneration was associated with COL2A1 downregulation and COL-10A1 upregulation.

CONCLUSIONS

COL10 was discovered to be a new biomarker for disk degeneration. Besides COL-1 and 2, other important COLs (6, 9, 11, 12, 14, 15) with anabolic potential and abundant expression in the fetal phenotype could be investigated for tissue engineering and novel DDD therapy.

An update on animal models of intervertebral disc degeneration and low back pain: Exploring the potential of artificial intelligence to improve research analysis and development of prospective therapeutics

Animal models have been invaluable in the identification of molecular events occurring in and contributing to intervertebral disc (IVD) degeneration and important therapeutic targets have been identified. Some outstanding animal models (murine, ovine, chondrodystrophoid canine) have been identified with their own strengths and weaknesses. The llama/alpaca, horse and kangaroo have emerged as new large species for IVD studies, and only time will tell if they will surpass the utility of existing models. The complexity of IVD degeneration poses difficulties in the selection of the most appropriate molecular target of many potential candidates, to focus on in the formulation of strategies to effect disc repair and regeneration. It may well be that many therapeutic objectives should be targeted simultaneously to effect a favorable outcome in human IVD degeneration. Use of animal models in isolation will not allow resolution of this complex issue and a paradigm shift and adoption of new methodologies is required to provide the next step forward in the determination of an effective repairative strategy for the IVD. AI has improved the accuracy and assessment of spinal imaging supporting clinical diagnostics and research efforts to better understand IVD degeneration and its treatment. Implementation of AI in the evaluation of histology data has improved the usefulness of a popular murine IVD model and could also be used in an ovine histopathological grading scheme that has been used to quantify degenerative IVD changes and stem cell mediated regeneration. These models are also attractive candidates for the evaluation of novel anti-oxidant compounds that counter inflammatory conditions in degenerate IVDs and promote IVD regeneration. Some of these compounds also have pain-relieving properties. AI has facilitated development of facial recognition pain assessment in animal IVD models offering the possibility of correlating the potential pain alleviating properties of some of these compounds with IVD regeneration.

Cement discoplasty for managing lumbar spine pseudarthrosis in elderly patients: a less invasive alternative approach for failed posterior lumbar spine interbody fusion

PURPOSE

A retrospective cohort study was performed to evaluate pseudoarthrosis treatment results by injection of cement in disc space of failed fusion in posterior lumbar interbody fusion in patients above 65 years.

METHODS

Forty-five patients above 65 years with symptomatic pseudarthrosis after lumbar spine fusion were treated by cement injection in the affected disc space.

RESULTS

There were 30 females and 15 males. The mean age at the operation was 74 ± 6.5 years (range 65-89). Discoplasty was performed after the primary fusion operations after a mean of 14 ± 1.3 months (range 12-24). The mean preoperative VAS was 7.5 (range 6-9), and ODI was 36 (range 30-45). Cement injection was done at one level in most of the cases (35 patients). In seven cases, two injection levels were done, and in three cases, three levels. Twenty-three patients had discoplasty only, while 22 had discoplasty and screws change, including 14 cases of extension of the instrumentation. The mean postoperative follow-up was 32 ± 6.5 months. The VAS improved to 3.5 (range 2-5) (p = 0.02) and ODI to 12.3 (range 5-35) (p = 0.001). Reoperation was indicated in two (4%) patients by screws loosening. Asymptomatic cement leakage occurred in the paravertebral space in seven cases (15.5%).

CONCLUSION

Cement discoplasty offers a less invasive reliable surgical solution in elderly patients with symptomatic lumbar pseudarthrosis in the elderly patients. In cases with screw loosening, discoplasty should be combined with screw revision.

Transabdominal Motor Action Potential Monitoring of Pedicle Screw Placement During Minimally Invasive Spinal Procedures: A Case Study

Precise pedicle screw placement is a critical skill during minimally invasive spinal surgeries but can pose various challenges. Techniques such as electromyography (EMG) have been traditionally utilized for this purpose but have several shortcomings. Transabdominal motor action potential (TaMAP) has been examined as a possible effective neuromonitoring alternative and is hypothesized to provide important data on symptomatic malpositioned pedicle screws. The current study seeks to determine whether TaMAP may be an advantageous technique in the neuromonitoring of percutaneous pedicle screw placement during minimally invasive spinal procedures. The methodology involved recording TaMAP signals at the outset and the conclusion of spinal surgical procedures in human participants, for which comparisons were made of pre- and post-operative data. Results revealed that TaMAP signals remained stable during accurate pedicle screw placement and degraded during a case of inaccurate placement, for which initial misplaced hardware altered the depolarization threshold and resulted in substantial signal alteration. These results suggest that TaMAP, which is stable, repeatable, and reflects real-time information, can potentially be used as a reliable and more precise indication of accuracy in pedicle screw placement during spinal surgeries. This is the first TaMAP study conducted in human participants.