Kalani, Maziyar A.

OBJECTIVE Surgical site infection (SSI) is a leading cause of morbidity following posterior spine surgery. The optimal choice of skin closure technique depending on patient- and procedure-specific characteristics remains to be elucidated. METHODS The Neurosurgery Enterprise Registry (NER) at Mayo Clinic was queried for patients who underwent posterior spine surgery from 2017 to 2023. Propensity matching was performed to match patients on the basis of the development of SSI and baseline characteristics, including age, sex, race, and comorbidities. Perioperative outcomes were analyzed using data from the NER and medical records. RESULTS A total of 18,842 cases of posterior spine surgery were identified in the NER, and SSI was observed in 154 cases (0.8%). Of these patients, 308 patients were included in the 1:1 propensity score–matched cohort analysis, with 154 patients included in each group. Sutures were used in 224 patients (72.7%) and staples in 84 patients (27.3%) (p < 0.01). Female patients comprised 45.1% of the sutures group and 46.4% of the staples group (p = 0.8). The mean ± SD age was 59.8 ± 15.4 years in the sutures group and 60.8 ± 11.9 years in the staples group (p = 0.6). Fusion was performed in 27.2% of patients in the sutures group and 44% in the staples group (p < 0.01). Multilevel fusion comprised 68.9% of fusion cases in the sutures group and 67.6% in the staples group (p = 0.8). Comorbidities, such as diabetes (p = 0.6), hypertension (p = 0.1), and the use of disease-modifying antirheumatic drugs (DMARDs) (p = 0.5) and immunosuppressants (p = 0.2), did not differ between groups. Univariate analysis performed in the propensity score–matched cohort showed that SSI was observed in 53.6% of patients in the sutures group and 40.5% in the staples group (p = 0.04). No significant differences were noted regarding 30-day (p = 0.3), 90-day (p = 0.2), and 1-year (p = 0.3) readmissions and 30-day (p = 0.7), 90-day (p = 0.8), and 1-year (p = 0.8) reoperations. On multivariable logistic regression, SSI was not significantly associated with the choice of skin closure technique (p = 0.3). CONCLUSIONS After adjustment for spinal fusion, number of fused levels, the use of immunosuppressants, and other risk factors, SSI development was not significantly associated with the use of sutures versus staples following posterior spine surgery in our institution. Additionally, no significant differences were observed regarding baseline characteristics and other perioperative outcomes. The authors’ analysis shows that skin closure technique did not significantly affect SSI rates and other outcomes in these patients.

Study design: Cohort study. Objective: This study aimed to evaluate influence of facet cysts on outcomes in patients undergoing lumbar decompression, and the influence of spinal fusion in patients undergoing decompression for facet cysts. Summary of Background Data: The impact of facet cysts on outcomes following lumbar spine surgery for degenerative spine disease remains unclear. Methods: Our multicenter institutional Neurosurgery Enterprise Registry was queried for patients who underwent lumbar decompression for degenerative spine conditions. Patients were divided into 2 cohorts: those with lumbar spine facet cysts and those without. Retrospective propensity-score matching was performed using 13 baseline variables to adjust for potential confounding factors, including age, sex, race, body mass index, and comorbidities. Secondary analysis comparing outcomes in patients with facet cysts cases undergoing decompression only versus those undergoing decompression and fusion was conducted. Results: A total of 6768 patients were reviewed, of which 188 (2.8%) had facet cysts, which underwent lumbar decompression during 2019–2023. After 3:1 matching, patients with facet cysts were compared with 564 patients without it. We found no significant differences in LOS, nonroutine discharge, postoperative complications, readmissions, and reoperations. In addition, in cases with facet cysts, decompression reported no increased risk for discharge opioids, readmissions, and reoperations, whereas fusion (in a separate cohort of 127 patients with facet cysts) was associated with an increased risk for nonroutine discharge (3.7% vs. 10.2%, P=0.021), complications (2.1% vs. 7.1%, P=0.042), and longer LOS (0.89±1.69 vs. 3.74±2.03 d, P<0.001) and operative time (138.78±62.99 vs. 273.07±111.51 min, P <0.001). Conclusions: The presence of facet cysts does not significantly affect outcomes of lumbar decompression for degenerative spine disease. Decompression alone for facet cysts can have better outcomes than decompression and fusion. The need for fusion should be weighted with its higher risks of complications, longer hospital stays, and nonroutine discharges.

Background: Vertebral body defects pose a significant challenge in spinal reconstructive surgery. Compression fractures of the vertebral corpus are typically treated with vertebral augmentation procedures. There are significant risks associated with the introduction of foreign material in the spine, including infection and pseudarthrosis. Vascularized bone grafts (VBGs) have become a popular alternative for spinal reconstruction in the last decade thanks to their robust blood supply and autologous nature. VBGs have been described predominantly for the reconstruction of posterior vertebral defects. The objective of this study is to describe a novel procedure for the reconstruction of vertebral corpus defects in the lumbar and distal thoracic spine. Methods: This is a cadaveric anatomy study. The authors performed the novel surgical technique on an anonymized cadaveric donor in the prone position and recorded the procedure through clinical photography. Consent for the procedure and photography was obtained from the Center for Procedural Innovation. Results: A 5-cm-long posterior iliac crest VBG (IC-VBG) was successfully harvested on a pedicle of the quadratus lumborum muscle. The VBG was rotated and mobilized anteromedially to the vertebral corpus. In this donor, the IC-VBG could be inset with minimal tension anywhere along the vertebral bodies of the spine from the L5 to the T9 level. Conclusions: A rotated, anteromedially mobilized IC-VBG represents a novel technique for reconstruction of the anterior vertebral corpus of the lumbar and distal thoracic spine with a lower risk of infection and pseudarthrosis than reconstruction with foreign materials.

Background/Objectives: Spino-plastic surgery describes a specialized, multidisciplinary approach to addressing various spinal pathologies. The field is the innovative product of a multidisciplinary collaboration between plastic and reconstructive, orthopedic, and neurosurgery. Over the last few decades, this collaboration has borne promising surgical techniques and treatment plans geared toward restoring form, function, and aesthetics in patients with a variety of spinal conditions, including failed fusions, pseudoarthrosis, and the need for oncologic reconstruction. This paper explores the application of spino-plastic surgery in the context of post-sarcoma resection reconstructions, focusing on the efficacy in addressing the unique challenges posed by extensive tissue loss and structural deformities. Methods: Our study reviews a series of cases wherein spino-plastic techniques were utilized in patients with sarcomas of the spine and adjacent structures. We also discuss the technical considerations, including preoperative planning, intraoperative challenges, and overall patient care, that are crucial for the success of spino-plastic procedures. Results: The outcomes demonstrate significant improvements in patient mobility, pain reduction, and overall quality of life. Most notably, spino-plastic surgical techniques help facilitate the restoration of functional anatomy by leveraging vascularized bone grafts and muscle flaps, thereby enhancing long-term stability and reducing the risk of complications such as nonunion or infection. Conclusions: Spino-plastic collaboration represents a pivotal advancement in oncologic treatment, spinal care, and reconstructive surgery, offering new hope for patients undergoing post-sarcoma reconstruction. Further research and refinement of the techniques will only expand their application and improve outcomes for a broader range of patients in the future.

Summary: Sacral reconstruction post tumor resection has historically been executed with the placement of hardware or free tissue transfer. Reconstruction using a vascularized bone graft is an alternative that avoids the complications associated with hardware placement or free tissue transfer. This article describes the first documented case of spinoplastic reconstruction using an iliac crest vascularized bone graft (IC-VBG) after the resection of a sacral ependymoma. This is a case of a 17-year-old boy with a history of a sacral myxopapillary ependymoma. He presented to a local emergency department complaining of 6 months of urinary incontinence and progressive paresthesias affecting the left lower extremity. Magnetic resonance imaging was significant for a lesion located in the extradural spinal canal. Biopsy confirmed a myxopapillary ependymoma, World Health Organization grade II. The initial intervention involved tumor resection with titanium hardware placement. He subsequently required replacement of the titanium hardware with carbon fiber, secondary to the need for surveillance imaging. He underwent harvesting and inset of the IC-VBG at the time of hardware replacement. IC-VBG is a safe and effective modality for spinoplastic reconstruction. It enhances the potential for solid bony union and offers a practical alternative to free bone transfer. This approach provides an asset to add to a reconstructive surgeon’s armamentarium, making it an essential tool for reconstructive surgeons working in conjunction with spinal surgery colleagues.

OBJECTIVE Chordomas are rare tumors of the skull base and spine believed to arise from the vestiges of the embryonic notochord. These tumors are locally aggressive and frequently recur following resection and adjuvant radiotherapy. Proton therapy has been introduced as a tissue-sparing option because of the higher level of precision that proton-beam techniques offer compared with traditional photon radiotherapy. This study aimed to compare recurrence in patients with chordomas receiving proton versus photon radiotherapy following resection by applying tree-based machine learning models. METHODS The clinical records of all patients treated with resection followed by adjuvant proton or photon radiotherapy for chordoma at Mayo Clinic were reviewed. Patient demographics, type of surgery and radiotherapy, tumor recurrence, and other variables were extracted. Decision tree classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS Fifty-three patients with a mean ± SD age of 55.2 ± 13.4 years receiving surgery and adjuvant proton or photon therapy to treat chordoma were identified; most patients were male. Gross-total resection was achieved in 54.7% of cases. Proton therapy was the most common adjuvant radiotherapy (84.9%), followed by conventional or external-beam radiation therapy (9.4%) and stereotactic radiosurgery (5.7%). Patients receiving proton therapy exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. This was confirmed on logistic regression analysis adjusted for extent of tumor resection and tumor location, which revealed that proton adjuvant radiotherapy was associated with a decreased risk of recurrence (OR 0.1, 95% CI 0.01–0.71; p = 0.047) compared with photon therapy. The decision tree algorithm predicted recurrence with an accuracy of 90% (95% CI 55.5%–99.8%), with the lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%). CONCLUSIONS Following resection, adjuvant proton therapy was associated with a lower risk of chordoma recurrence compared with photon therapy. The described machine learning models were able to predict tumor progression based on the extent of tumor resection and adjuvant radiotherapy modality used.

Summary: Pseudoarthrosis is a severe complication of spinal fusion surgery with occurrence rates as high as 35%–40%. Current options of revision surgery to correct pseudoarthrosis frequently carry high failure rates and risk of developing junctional kyphosis. Pedicled vascularized bone grafts (VBGs) are an innovative approach to boost spinal fusion rates via improving structural integrity and increasing the delivery of blood to the donor site. This versatile technique can be performed at different spinal levels without additional skin incisions and with minimal added operative time. Here we present the first bilateral rib and iliac crest VBG spinoplastic surgery performed to augment spinal fusion in a 68-year-old woman with distal junctional kyphosis and severe positive sagittal balance with low back and neck pain and significant difficulty standing upright. The patient had history of multiple spinal operations with preoperative CT imaging demonstrating loosening and pull out of L3 and fracture of L2 screws. She underwent two-stage surgical treatment involving anterior lumbar interbody fusion L3-S1 followed by removal of hardware, T4 to pelvis fusion with L2-3 prone lateral interbody fusion, and T11-S1 posterior column osteotomies. The surgery was augmented by bilateral rib and iliac crest VBGs performed by plastic surgery. At three-month follow-up the patient demonstrated functional improvement, being able to maintain upright posture and walk; was satisfied with the result of the surgery; and demonstrated no graft-related complications. In conclusion, utilization of pedicled VBGs is a novel, promising approach to augment spinal surgery in high risk patients.

ABSTRACT The role of plastic surgeons in the world of spine surgery is quickly evolving. The plastic surgeon now serves both a therapeutic and prophylactic role in addressing complications of complex and revision spine surgery. The field of Spino-plastic Surgery is characterized by the use of vascularized bone grafts (VBGs). VBGs are bone segments transferred on their corresponding muscular attachments without the inclusion of a named vessel. The bone graft is adequately vascularized through the connection of the tendon by Sharpey's fibers and their associated microvasculature. VBGs provide an autologous, pedicled tissue rearrangement option with osteoinductive properties and adequate structural support for complex spine reconstruction. VBGs are associated with a lower risk of adverse events and shorter times to fusion than allografts, and bypass the need for lengthy microsurgical anastomosis. Five types of VBGs for spine reconstruction are described in this article, including iliac crest, rib, occiput, scapula, and spinous process VBG. Virtually any vertebral level can be reached for arthrodesis using one or more of these VBGs. Highlights Vascularized bone grafts are bone segments transferred on muscular attachments without the inclusion of a named vessel.Vascularized bone grafts provide an autologous, pedicled tissue rearrangement option for complex spine reconstruction with a lower risk of adverse events and shorter times to fusion than allografts.Five types of vascularized bone grafts for spine reconstruction have been described: iliac crest, rib, occiput, scapula, and spinous process.Virtually any vertebral level can be reached for arthrodesis using one or more vascularized bone grafts.

OBJECTIVE Chordomas are slow-growing tumors derived from notochord remnants. Despite margin-negative excision and postoperative radiation therapy, spinal chordomas (SCs) often progress. The potential of immunohistochemical (IHC) markers, such as epithelial membrane antigen (EMA), combined with machine learning algorithms to predict long-term (≥ 12 months) postoperative tumor progression, has been understudied. The authors aimed to identify IHC markers using trained tree-based algorithms to predict long-term (≥ 12 months) postoperative tumor progression. METHODS The authors reviewed the records of patients who underwent resection of SCs between January 2017 and June 2021 across the Mayo Clinic enterprise. Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient’s record. Low tumor progression was defined as more than a 94.3-mm3 decrease in the tumor size at the latest radiographic follow-up. Decision trees and random forest classifiers were trained and tested to predict the long-term volumetric progression after an 80/20 data split. RESULTS Sixty-two patients diagnosed with and surgically treated for SC were identified, of whom 31 were found to have a more advanced tumor progression based on the tumor volume change cutoff of 94.3 mm3. The mean age was 54.3 ± 13.8 years, and most patients were male (62.9%) and White (98.4%). The most common treatment modality was subtotal resection with radiation therapy (35.5%), with proton beam therapy being the most common (71%). Most SCs were sacrococcygeal (41.9%), followed by cervical (32.3%). EMA-positive SCs had a postoperative progression risk of 67%. Pancytokeratin-positive SCs had a progression rate of 67%; however, patients with S100 protein–positive SCs had a 54% risk of progression. The accuracy of this model in predicting the progression of unseen test data was 66%. Pancytokeratin (mean minimal depth = 1.57), EMA (mean minimal depth = 1.58), cytokeratin A1/A3 (mean minimal depth = 1.59), and S100 protein (mean minimal depth = 1.6) predicted the long-term volumetric progression. Multiway variable importance plots show the relative importance of the top 10 variables based on three measures of varying significance and their predictive role. CONCLUSIONS These IHC variables with tree-based machine learning tools successfully demonstrate a high capacity to identify a patient’s tumor progression pattern with an accuracy of 66%. Pancytokeratin, EMA, cytokeratin A1/A3, and S100 protein were the IHC drivers of a low tumor progression. This shows the power of machine learning algorithms in analyzing and predicting outcomes of rare conditions in a small sample size.