Perioperative Complications Following Spine Surgery in Adult Patients with Achondroplasia.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To describe the common types of complications and their risk factors during spine surgery in patients with achondroplasia. METHODS: A retrospective review was performed of medical records of adult achondroplasia patients who underwent spine surgery at our institution between 2007 and 2021. Inclusion criteria were achondroplasia and age >16 years. Surgical encounters were evaluated for durotomy, postoperative neurologic deficit, wound compromise, medical complications, and return to the operating room. Statistical analysis included evaluation of relationships across complications and fisher exact test applied to bivariate/categorical variables and t-test/ANOVA for continuous variables. Multivariable analysis using logistic regression was performed to account for patient characteristics. RESULTS: Fifty-five patients with achondroplasia underwent 95 surgeries. Forty-nine percent of the surgeries involved a complication. These included durotomy (33.7%), neurologic deficit (11.6%), wound compromise (6.3%), and other medical complications (6.3%). Thirteen percent of surgeries required return to the operating room. The greatest number of complications occurred in thoracolumbar region (60.0%) compared to cervicothoracic (18.2%) and craniocervical junction (33.3%). Chronologically later surgical encounters had decreased complications and durotomies only occurred in thoracolumbar surgeries (45.7%). CONCLUSIONS: Adult patients with achondroplasia undergoing surgery chronologically later in this set of consecutive patients were at a decreased risk for complications. Thoracolumbar surgeries were at the greatest risk for durotomies. Male sex was a risk factor for durotomy, while age was a risk factor for neurologic deficit. The potential for adverse surgical events should be considered when evaluating patients with achondroplasia for spine surgery. .

NF-κB inhibitor, NEMO-binding domain peptide attenuates intervertebral disc degeneration.

BACKGROUND CONTEXT: Nonphysiological mechanical loading and inflammation are both critically involved in intervertebral disc (IVD) degeneration, which is characterized by an increase in cytokines and matrix metalloproteases (MMPs) in the nucleus pulposus (NP). This process is known to be mediated by the NF-κB pathway. CLINICAL SIGNIFICANCE: Current clinical treatments for IVD degeneration focus on the alleviation of symptoms rather than targeting the underlying mechanism. Injection of an NF-κB inhibitor may attenuate the progression of IVD degeneration. PURPOSE: To investigate the ability of the NF-κB inhibitor, NEMO binding domain peptide (NBD), to alter IVD degeneration processes by reducing IL-1ß- and mechanically-induced cytokine and MMP levels in human nucleus pulposus cells in vitro, and by attenuating IVD degeneration in an in vivo rat model for disc degeneration. STUDY DESIGN: Experimental in vitro and animal model. PATIENT SAMPLE: Discarded specimens of lumbar disc from 21 patients, and 12 Sprague Dawley rats. OUTCOME MEASURES: Gene and protein expression, cell viability, µMRI and histology. METHODS: IL-1ß-prestimulated human nucleus pulposus cells embedded into fibrin constructs were loaded in the Flexcell FX-5000 compression system at 5 kPa and 1 Hz for 48 hours in the presence and absence of NBD. Unloaded hNPC/fibrin constructs served as controls. Cell viability in loaded and unloaded constructs was quantified, and gene and protein expression levels determined. For in vivo testing, a rat needle disc puncture model was employed. Experimental groups included injured discs with and without NBD injection and uninjured controls. Levels of disc degeneration were determined via µMRI, qPCR and histology. Funding sources include $48,874 NASS Young Investigator Research Grant and $119,174 NIH 5K01AR071512-02. There were no applicable financial relationships or conflicts of interest. RESULTS: Mechanical compression of hNPC/fibrin constructs resulted in upregulation of MMP-3 and IL-8. Supplementation of media with 10 µM NBD during loading increased cell viability, and decreased MMP-3 gene and protein levels. IVD injury in rat resulted in an increase in MMP-3, IL-1ß and IL-6 gene expression. Injections of 250 µg of NBD during disc injury resulted in decreased IL-6 gene expression. µMRI analysis demonstrated a reduction of disc hydration in response to disc needle injury, which was attenuated in NBD-treated IVDs. Histological evaluation showed NP and AF lesion in injured discs, which was attenuated by NBD injection. CONCLUSIONS: The results of this study show NBD peptide's capacity to reduce IL-1ß- and loading-induced MMP-3 levels in hNPC/fibrin constructs while increasing the cells' viability, and to attenuate IVD degeneration in rat, involving downregulation of IL-6. Therefore, NBD may be a potential therapeutic agent to treat IVD degeneration.

Access strategies for revision in anterior lumbar surgery.

STUDY DESIGN: Sixty-two consecutive patients undergoing anterior lumbar revision surgery from February 2000 to September 2007 were evaluated for approach strategies and complications. OBJECTIVE: To determine the incidence of complications in these patients and to make recommendations on future revisions based on the results obtained. SUMMARY OF BACKGROUND DATA: Only 2 articles exist in the literature that address this situation and they have widely varying results in a small number of patients. This larger series may help give more certainty to the expectations for complications in patients undergoing revision anterior lumbar surgery. METHODS: A concurrent database was maintained on these 62 consecutive patients. Preoperative strategies were evaluated and complications were tabulated as they occurred and later analyzed to arrive at recommendations for future similar cases. RESULTS: Twenty-three patients had the same level revised and 39 patients had adjacent levels operated on. There were 3 venous injuries (4.8%), 3 arterial injuries (4.8%), and 1 ureteral injury (1.6%). All 3 arterial injuries occurred while approaching L3-L4 after L4 to S1 prior fusion or disc replacement. All 3 venous injuries and the ureteral injury occurred while approaching a previously operated level or levels. Six of these patients had the injuries repaired and the procedures completed with full recovery. One L5-S1 revision had the procedure aborted after a venous injury. There were no deaths. CONCLUSION: Although the incidence of complications in revisions is much greater than for index cases, the actual percentage of venous, arterial, and ureteral complications is certainly acceptable for patients who must have this type of surgery. Only very experienced access surgeons should attempt revision surgery.

Kyphoplasty reduction of osteoporotic vertebral compression fractures: correction of local kyphosis versus overall sagittal alignment.

STUDY DESIGN: A retrospective study of patients who underwent 1-3-level kyphoplasty procedures at a single institute. OBJECTIVE: To examine and compare the effects of single and multilevel kyphoplasty procedures on local versus overall sagittal alignment of the spine. SUMMARY OF BACKGROUND DATA: Cement augmentation has been a safe and effective method in the treatment of symptomatic vertebral compression fractures (VCFs). In addition to providing rapid pain relief, balloon tamp kyphoplasty has reduced acute fractures, allowed controlled cement placement under lower pressure, and resulted in improvement of deformity. The restoration of normal overall spinal sagittal alignment in the elderly patient with a VCF and kyphotic deformity has obvious benefits. Although significant correction of local kyphosis (fractured vertebra) has been reported in the literature, to our knowledge, there have been no reports on whether this leads to an improved overall sagittal alignment. METHODS: A total of 65 consecutive patients with symptomatic VCFs who underwent 1-3-level kyphoplasty procedures were included in the study. Preoperative and postoperative radiographs were analyzed to quantify local and overall spinal sagittal alignment correction. Preoperative and postoperative vertebral heights at the fractured levels were also measured and categorized into anterior, middle, or posterior vertebral heights. RESULTS: Measurements revealed that kyphoplasty reduced local kyphotic deformity at the fractured vertebra by an average of 7.3 degrees (63% of preoperative kyphosis). This result did not translate to similar correction in overall sagittal alignment. In fact, angular correction decreased to 2.4 degrees (20% of preoperative kyphosis at fractured level) when measured 1 level above and below. The angular correction further decreased to 1.5 degrees and 1.0 degrees (13% and 8% of preoperative kyphosis at fractured level), respectively, at spans of 2 and 3 levels above and below. Average height gain was highest in the middle of the vertebral body (39% increase) compared to the anterior or posterior edges (19% and 3% increases, respectively). With multilevel kyphoplasty procedures, higher angular gains were seen over more vertebrae compared to the 7.3 degrees for a single-level kyphoplasty: 7.8 degrees over 2 levels and 7.7 degrees over 3 levels for 2 and 3-level kyphoplasty procedures, respectively. Kyphoplasty was able to achieve higher angular reduction in thoracic versus lumbar fractures (8.5 vs. 6.4 degrees, P < 0.01). The angular correction was also better maintained over adjacent segments in the thoracic spine. CONCLUSION: The majority of kyphosis correction by kyphoplasty is limited to the vertebral body treated. The majority of height gained after kyphoplasty occurs in the midbody. Higher correction over longer spans of the spine can be achieved with multilevel kyphoplasty procedures, in proportion to the number of levels addressed. Notwithstanding its well-published clinical efficacy, it is unrealistic to expect a 1 or 2-level kyphoplasty to improve significantly the overall sagittal alignment after VCFs.