Background: Hereditary Multiple Osteochondromas (HMO), previously known as Multiple Hereditary Exostoses (MHE), is a genetic disorder characterized by the formation of multiple, benign, exostoses (osteochondromas) growing from the metaphyseal region of long bones as well as from the axial skeleton. Lesions originating from the lumbar spine region are rare, and are most common growing from the posterior element of the vertebrae. HMO associated osteochondromas are difficult to treat due to continuous and incontrollable growth of these lesions and a lifetime risk for malignant transformation.
Case report: We describe a case of a 16-year old patient with known HMO who developed a giant ilio-lumbo-sacral osteochondroma. The tumor protruded into the L4-S1 intraspinal foramina with exophytic expansion to the right psoas muscle and lumbar plexus with compression of the right common iliac vein. To plan and execute the resection and minimize the risk of complications, we used a 3D printed model of the lesion with intraabdominal vessels. The patient was operated during a two-stage procedure - first by mini-open, transabdominal, navigated resection of the lesion, followed by delayed posterior, mini-invasive, navigated resection. The outcome was uneventful and there were no signs of regrowth or malignant transformation during 4 years of follow-up.
Conclusion: We describe a 360-degree surgical resection with application of a 3D printed model, navigation, and mini-invasive techniques. Our report may be useful and inspire spine surgeons to apply similar techniques to treat complex spine lesions.
Published online: 30 December 2024.
BACKGROUND: Hirayama's disease (HD) is most common in young males, and previous studies are predominantly from Asian countries. The cause of HD is unknown but the most common theory about the pathology speculates on forward bending that causes a compression of the dura mater and the anterior horn of the spinal cord against the vertebra during an overstretch flexion that may result in myelopathy. Both anterior and posterior cervical surgical approaches have been shown to be effective in stopping the disease and improving function; however, HD is also reported to be a self-limited disease, and treatment with a cervical collar may be an alternative for these patients.
CASE REPORT: We report HD in a 17-year-old male from Sweden who underwent surgical treatment with a 2 level anterior cervical discectomy and fusion (ACDF) due to neurological progression from HD after conservative treatment.
CONCLUSION: HD is rare and is easily overlooked. Surgical intervention shows promising results for neurological progression, but HD is also reported to be a self-limited disease.
BACKGROUND: The Swedish Fracture Register (SFR) is a national quality register for all types of fractures in Sweden. Spine fractures have been included since 2015 and are classified using a modified AOSpine classification. The aim of this study was to determine the accuracy of the classification of thoracolumbar burst fractures in the SFR.
METHODS: Assessments of medical images were conducted in 277 consecutive patients with a thoracolumbar burst fracture (T10-L3) identified in the SFR. Two independent reviewers classified the fractures according to the AOSpine classification, with a third reviewer resolving disagreement. The combined results of the reviewers were considered the gold standard. The intra- and inter-rater reliability of the reviewers was determined with Cohen's kappa and percent agreement. The SFR classification was compared with the gold standard using positive predictive values (PPV), Cohen's kappa and percent agreement.
RESULTS: The reliability between reviewers was high (Cohen's kappa 0.70-0.97). The PPV for correctly classifying burst fractures in the SFR was high irrespective of physician experience (76-89%), treatment (82% non-operative, 95% operative) and hospital type (83% county, 95% university). The inter-rater reliability of B-type injuries and the overall SFR classification compared with the gold standard was low (Cohen's kappa 0.16 and 0.17 respectively).
CONCLUSIONS: The SFR demonstrates a high PPV for accurately classifying burst fractures, regardless of physician experience, treatment and hospital type. However, the reliability of B-type injuries and overall classification in the SFR was found to be low. Future studies on burst fractures using SFR data where classification is important should include a review of medical images to verify the diagnosis.
Purpose: Instrumentation of the C1 vertebra requires either mobilization or transection of the C2 nerve root. This study investigates clinical and radiological outcomes and incidences of C2 neuropathic pain after posterior instrumented fusion in the cranio-cervical junction with or without division of the C2 nerve roots.
Methods: This retrospective study compared two cohorts of patients who underwent instrumented fusion in the cranio-cervical junction. Fifty patients (22 males and 28 females) were operated with complete resection of C2 nerve root ganglion (Ex group), and fifty-one patients (30 men, 21 women) with C2 nerve roots preservation (No group).
Results: The incidence of postoperative C2 neuropathy was eight times lower in the Ex group compared to the No group that was statistical significant, p = 0.039. Surgical time was significantly shorter in the No group (p = 0.001). The fusion rates were very high for both groups, without difference between groups (p = 1.0). Autografting from the iliac crest (p = 0.001) as well as postoperative immobilisation with a hard collar (p < 0.001) were required in fewer patients in the Ex group. Also, patients in the Ex group were mobilised faster after surgery (p = 0.49). Overall, complication rates were similar between groups, but the Ex group demonstrated fewer major medical complications (16% vs 31%). Male sex and iliac bone harvesting demonstrated significantly higher OR for development of postoperative complications (p = 0.023 and p = 0.034 respectively) and postoperative mobilization demonstrated significant higher OR for development of postoperative major complications (p = 0.042).
Conclusions: Resection of the C2 nerve root ganglion during posterior instrumented fusion of the cranio-cervical junction is safe and rarely leads to C2 neuropathy. The technique tends to mitigate the odds of developing postoperative complications.
Background: Bone metastases can compromise the integrity of the spinal canal and cause epidural spinal cord compression (ESCC). The Spinal Instability Neoplastic Score (SINS) was developed in order to evaluate spinal instability due to a neoplastic process. The SINS has reached wide acceptance among clinicans but its prognostic value is still controversial. The aim was to investigate the correlation between the SINS and ESCC and the association between SINS and ambulation before and survival after surgery.
Methods: Correlations were assessed between SINS and grades of ESCC in patients who underwent spine surgery for spinal metastases. CT and MRI were used to calculate SINS and the grades of ESCC respectively. Correlations were analyzed with the Spearman’s correlation test. Postoperative survival was estimated with Kaplan-Meier analysis and survival curves were compared with the log-rank test. The Cox proportional hazard model was used to assess the effect of prognostic variables including age, ambulation before surgery, SINS, and the Karnofsky Performance Status (KPS) as covariates.
Results: The study included 256 patients (196 men and 60 women) with a median age of 70 (24–88) years. The mean SINS was 10. One hundred fifty-two patients (59%) had lost ambulation before surgery. One hundred and one patients had grades 0–2 and 155 patients had grade 3 according to the ESCC-scale. SINS correlated with the grades of ESCC (p = 0.001). The SINS score was not associated with ambulation before surgery (p = 0.63). The median postoperative survival was 10 months, and there was no difference in postoperative survival between the SINS categories (p = 0.25). The ability to walk before surgery and a high KPS were associated with longer postoperative survival.
Conclusion: SINS correlated with grades of ESCC, which implies that higher SINS may be considered as an indicator of risk for developing ESCC. The SINS was not associated with ambulation before or survival after surgery.
Background: Intraoperative (IO) image guidance surgery using 3-dimensional fluoroscopic navigation methods, such as the O-arm system, has improved the accuracy of pedicle screw placement in instrumented spine surgery. IO and postoperative (PO) validation of the implant’s correct position from radiological images is a decisive step to ensure patient safety and avoidance of complications related to implant misplacement. In this prospective single-center study, the authors investigated the accuracy and agreement of assessment of pedicle screws from IO O-arm images in comparison to PO computed tomography images. This study aimed to determine whether a final evaluation of pedicle screws can safely be conducted from IO images that supersede the PO computed tomography control.
Methods: A prospective single-center study was carried out at the Spine Unit in the Department of Orthopedics at Umeå University Hospital between 2019 and 2021. All patients enrolled in the study underwent instrumented thoracolumbar spine surgery using navigation. Imaging data were obtained from IO and PO examinations. Four reviewers—2 attending senior spine surgeons, 1 final year resident in orthopedics, and 1 attending neuroradiologist—classified pedicle screws using the Gertzbein and Robbins classification system. Agreement and accuracy of the reviewers were studied to evaluate the assessment of pedicle screws from IO and PO images.
Results: A total of 70 patients (422 screws) were included in the study. There was high accuracy among surgeons both on IO and PO images (0.96–0.97, 95% CI [0.94–0.99] and 0.97, 95% CI [0.94–0.99], respectively), and the overall agreement between all raters was 92% to 98% (95% CI [0.90, 1.00]). The discrepancy in assessment between optimal (Group 1) and suboptimal (Group 2) screws between IO and PO images was as low as 1% to 1.7%, which indicates that very few suboptimal screws are missed in the assessment of IO images.
Conclusions: The assessment of navigated pedicle screws using IO images is safe and reliable and may replace the need for further assessment using PO imaging.
BACKGROUND: Patients with ankylosing spondylitis (AS) are prone to spinal fractures even after low-energy trauma. Posterior fusion through open surgery has been the standard procedure for spinal fractures in patients with AS. Minimally invasive surgery (MIS) has been proposed as an alternative treatment option. There are few literature reports regarding patients with AS being treated for spinal fractures with MIS. This study aims to present the clinical outcome of a series of patients with AS treated with MIS for spinal fractures.
METHODS: We included a consecutive series of patients with AS who underwent MIS for thoracolumbar fractures between 2014 and 2021. The median follow-up was 38 (12-75) months. Medical records and radiographs were reviewed, and data on surgery, reoperations, complications, fracture healing, and mortality were recorded.
RESULTS: Forty-three patients (39 [91%] men) were included with a median (range) age of 73 (38-89) years. All patients underwent image-guided MIS with screws and rods. Three patients underwent reoperations, all due to wound infections. One patient (2%) died within 30 days and 7 (16%) died within the first year after surgery. Most patients with a radiographic follow-up of 12 months or more (29/30) healed with a bony fusion on computed tomography (97%).
CONCLUSION: Patients with AS and a spinal fracture are at risk of reoperation and have significant mortality during the first year. MIS provides adequate surgical stability for fracture healing with an acceptable number of complications and is an adequate choice in treating AS-related spinal fractures.
STUDY DESIGN: We retrospectively analyzed Spinal Instability Neoplastic Score (SINS) in 110 patients with prostate cancer operated for metastatic spinal cord compression (MSCC).
OBJECTIVE: We aimed to investigate the association between SINS and clinical outcomes after surgery for MSCC in patients with prostate cancer.
SUMMARY OF BACKGROUND DATA: The SINS is a useful tool for assessing tumor-related spinal instability, but its prognostic value regarding survival and neurological outcome is still controversial.
METHODS: We analyzed 110 consecutive patients with prostate cancer who underwent surgery for MSCC. The patients were categorized according to their SINS. Patients with castration-resistant prostate cancer (CRPC, n = 84) and those with hormone-naïve disease (n = 26) were analyzed separately.
RESULTS: In total, 106 of 110 patients met the SINS criteria for potential instability or instability (scores 7-18). The median SINS was 10 (range 6-15) for patients with CRPC and 9 (7-16) for hormone-naïve patients. In the CRPC group, the SINS was classified as stable (score 0-6) in 4 patients, as potentially unstable (score 7-12) in 70 patients, and as unstable (score 13-18) in 10 patients. In the hormone-naïve group, 22 patients met the SINS criteria for potential instability and 4 patients for instability. There was no statistically significant difference in the overall risk for death between the SINS potentially unstable and unstable categories (adjusted hazard ratio 1.3, P = 0.4), or in the risk of loss of ambulation 1 month after surgery (adjusted odds ratio 1.4, P = 0.6).
CONCLUSION: The SINS is helpful in assessing spinal instability when selecting patients for surgery, but it does not predict survival or neurological outcomes. Patients with a potential spinal instability benefit equally from surgery for MSCC as do patients with spinal instability.
Level of Evidence: 3.
STUDY DESIGN: Researchers created a proper type II dens fracture (DF) and quantified a novel current posterior fixation technique with spacers at C1-C2. A clinical case study supplements this biomechanical analysis.
PURPOSE: Researchers explored their hypothesis that spacers combined with posterior instrumentation (PI) reduce range of motion significantly, possibly leading to better fusion outcomes.
OVERVIEW OF LITERATURE: Literature shows that the atlantoaxial joint is unique in allowing segmental rotary motion, enabling head turning. With no intervertebral discs at these joints, multiple ligaments bind the axis to the skull base and to the atlas; an intact odontoid (dens) enhances stability. The most common traumatic injury at these strong ligaments is a type II odontoid fracture.
METHODS: Each of seven specimens (C0-C3) was tested on a custom-built six-degrees-of-freedom spine simulator with constructs of intact state, type II DF, C1-C2 PI, PI with joint capsulotomy (PIJC), PI with spacers (PIS) at C1-C2, and spacers alone (SA). A bending moment of 2.0 Nm (1.5°/sec) was applied in flexion-extension (FE), lateral bending (LB), and axial rotation (AR). One-way analysis of variance with repeated measures was performed.
RESULTS: DF increased motion to 320%, 429%, and 120% versus intact (FE, LB, and AR, respectively). PI significantly reduced motion to 41%, 21%, and 8%. PIJC showed negligible changes from PI. PIS reduced motion to 16%, 14%, and 3%. SA decreased motion to 64%, 24%, and 54%. Reduced motion facilitated solid fusion in an 89-year-old female patient within 1 year.
CONCLUSIONS: Type II odontoid fractures can lead to acute or chronic instability. Current fixation techniques use C1-C2 PI or an anterior dens screw. Addition of spacers alongside PI led to increased biomechanical rigidity over intact motion and may offer an alternative to established surgical fixation techniques.