Buck technique supplemented by temporary intersegmental pedicle screw fixation to repair lumbar spondylolysis in youth.

BACKGROUND: Lumbar spondylolysis is a bone defect in the pars interarticularis of the lumbar vertebral, which is a common cause of low back pain in youth. Although non-surgical treatment is a mainstream option, surgery is necessary for patients with persistent symptoms. Buck technique is widely used as a classical direct repair technique, but it cannot achieve reduction of low-grade spondylolisthesis and reconstruction of lumbosacral sagittal balance. We have described a novel surgical procedure based on Buck technique with temporary intersegmental pedicle screw fixation, and report a series of clinical outcomes in 5 patients to provide a reference for the clinical treatment of young lumbar spondylolysis. METHODS: Five young patients with symptomatic lumbar spondylolysis with a mean age of 19.20 ± 5.41 years underwent surgical treatment after an average of 7.60 ± 1.52 months of failure to respond to conservative treatment, using a new surgical procedure based on Buck technique combined with temporary intersegmental pedicle screw fixation. RESULTS: Five patients were successfully operated without serious complications such as nerve and vascular injury. The average operation time was 109.00 ± 7.42 min, the interpretative average blood loss was 148.00 ± 31.14 ml, and the average fusion time was 11.20 ± 1.64 months. All patients were followed up for 2 years after surgery, and the visual analogue score (VAS) of low back pain and Oswestry disability index (ODI) scores were significantly improved compared with those before surgery, and the Henderson's evaluation were rated excellent or good. After the removal of the internal fixation, it was observed that temporary intersegmental fixation could repair the isthmus, reduce lumbar spondylolisthesis, and reconstruct the sagittal balance of the lumbosacral vertebrae while preserving lumbar motion and preventing intervertebral disc degeneration. Postoperative MRI indicated the Pfirrmann classification of the affected discs: 1 case from grade III to grade II, 3 cases from grade II to grade I, and 1 case remained grade II. CONCLUSIONS: Buck technique supplemented by temporary intersegmental pedicle screw fixation is a highly applicable and effective method for the treatment of adolescent lumbar spondylolysis. The isthmic fusion is accurate, and temporary intersegmental fixation can effectively prevent disc degeneration and reconstruct the sagittal balance of lumbosacral vertebra.

Development and biomechanical analysis of an axially controlled compression spinal rod for lumbar spondylolysis.

BACKGROUND: To elucidate the differences in mechanical performance between a novel axially controlled compression spinal rod (ACCSR) for lumbar spondylolysis (LS) and the common spinal rod (CSR). METHODS: A total of 36 ACCSRs and 36 CSRs from the same batch were used in this study, each with a diameter of 6.0 mm. Biomechanical tests were carried out on spinal rods for the ACCSR group and on pedicle screw-rod internal fixation systems for the CSR group. The spinal rod tests were conducted following the guidelines outlined in the American Society for Testing and Materials (ASTM) F 2193, while the pedicle screw-rod internal fixation system tests adhered to ASTM F 1798-97 standards. RESULTS: The stiffness of ACCSR and CSR was 1559.15 ±â€…50.15 and 3788.86 ±â€…156.45 N/mm (P < .001). ACCSR's yield load was 1345.73 (1297.90-1359.97) N, whereas CSR's was 4046.83 (3805.8-4072.53) N (P = .002). ACCSR's load in the 2.5 millionth cycle of the fatigue four-point bending test was 320 N. The axial gripping capacity of ACCSR and CSR was 1632.53 ±â€…165.64 and 1273.62 ±â€…205.63 N (P = .004). ACCSR's torsional gripping capacity was 3.45 (3.23-3.47) Nm, while CSR's was 3.27 (3.07-3.59) Nm (P = .654). The stiffness of the pedicle screws of the ACCSR and CSR group was 783.83 (775.67-798.94) and 773.14 (758.70-783.62) N/mm (P = .085). The yield loads on the pedicle screws of the ACCSR and CSR group was 1345.73 (1297.90-1359.97) and 4046.83 (3805.8-4072.53) N (P = .099). CONCLUSION: Although ACCSR exhibited lower yield load, stiffness, and fatigue resistance compared to CSR, it demonstrated significantly higher axial gripping capacity and met the stress requirement of the human isthmus. Consequently, ACCSR presents a promising alternative to CSR for LS remediation.

Are trunk muscle sizes different between acute lumbar spondylolysis and nonspecific low back pain?

INTRODUCTION: Morphological differences in the trunk muscles between adolescent athletes with lumbar spondylolysis (LS) and nonspecific low back pain (NSLBP) have not been fully elucidated. This study aimed to investigate the differences in physiological cross-sectional areas (CSA) of the trunk muscles between athletes with acute LS and those with acute NSLBP. METHODS: Magnetic resonance images of 48 patients aged 13-14 years diagnosed with acute LS or NSLBP were retrospectively evaluated. The CSA of the paraspinal, psoas major, and rectus abdominis muscles at the L4-5 intervertebral disc level were measured. RESULTS: CSA of the left and right paraspinal muscles in the acute LS group were significantly larger than those in the acute NSLBP group (left: mean difference, 276.0 mm2; 95% confidence interval [CI], 68.5-483.6 mm2; P = 0.01; right: mean difference, 228.8 mm2; 95% CI, 7.6-450.1 mm2; P = 0.04). The ratio between the left paraspinal muscles and left psoas major in the acute LS group was significantly larger than that in the acute NSLBP group (mean difference, 0.2; 95% CI, 0.0-0.4; P = 0.03). CONCLUSIONS: Trunk muscle size may differ between adolescent athletes with acute LS and those with NSLBP. Future research involving healthy controls is required to better understand the morphological characteristics of these injuries.

Successful Treatment of Cervical Spondylolysis with Grade-II Spondylolisthesis using Single-Level ACDF: A Case Report.

BACKGROUND Cervical spondylolysis with spondylolisthesis is a rare disorder. According to previous reports, the spondylolisthesis is usually Meyerding Grade I, with only a limited number of cases receiving surgical treatment. We hereby report a special case of cervical spondylolysis with Grade-II spondylolisthesis, treated with single-level anterior cervical discectomy and fusion (ACDF), and present a literature review related to this problem. CASE REPORT Here, we report the case of a 52-year-old man who complained of posterior neck pain and numbness of the bilateral upper limbs. Radiological examination showed bilateral spondylolysis of the C6 and Meyerding Grade-II spondylolisthesis of C6 on C7 with instability. The patient underwent a single-level C6/C7 ACDF surgery. The symptoms of neck pain and bilateral upper-limb numbness were relieved immediately after surgery. The immediate postoperative radiological examination showed successful restoration of sagittal alignment. At 3-month follow-up, the patient had returned to normal life without any symptoms. At 2-year follow-up, computed tomography showed that C6-C7 fusion had been achieved and alignment was maintained. CONCLUSIONS Cervical spondylolysis, as an uncommon spinal disorder, has been regarded as a congenital abnormity, and has unique radiological characteristics. For most of the cases with cervical spondylolysis, even with Grade-II spondylolisthesis, single-level ACDF can achieve good clinical and radiological outcomes.

[Slipped vertebrae (Spondylolysis): the underestimated weak point of the (pre)professional football player-an algorithm]. / Der Gleitwirbel: unterschätzte Schwachstelle des (prä)professionellen Fußballspielers ­ ein Algorithmus.

BACKGROUND: Isthmic spondylolysis represents the most common cause of spinal pain in adolescent athletes. This article provides an overview of the classification, diagnosis, and treatment options for these conditions, including conservative and operative measures. It also provides a treatment pathway to how young athletes with spondylolysis should be treated. DIAGNOSTICS: Diagnostic imaging techniques are essential for an accurate diagnosis, with CT scans providing additional information for surgical planning. TREATMENT: Conservative treatment focuses on activity modification and physiotherapy, with a phased approach tailored to individual patient needs. Operative intervention may be considered if conservative measures fail, with minimally invasive techniques such as Buck's screw fixation showing promising results. The decision between conservative and operative management should consider factors of the patients' individual profile. In this paper, we present the first treatment algorithm for the treatment of isthmic spondylolysis. Long-term prognosis varies, with most athletes able to return to sport following treatment.

Biportal endoscopic bone graft repair and percutaneous screw fixation for lumbar spondylolysis-technical note and clinical outcomes.

BACKGROUND: Lumbar spondylolysis involves a bony defect in the vertebral pars interarticularis, predominantly affecting the lower lumbar spine. This condition is a significant etiological factor in lumbar instability and recurrent lower back pain, particularly in young individuals. While conservative treatments are the primary intervention, they often fail to provide relief, necessitating surgical approaches. Notwithstanding, executing bone grafting and fixation in the pars interarticularis defect simultaneously through minimally invasive surgery remains challenging. METHOD: This study elucidates the biportal endoscopic spinal surgery (BESS) technique, innovatively applied for bone graft repair and percutaneous cannulated screw fixation in a patient with lumbar spondylolysis. We offer a detailed walkthrough of the technical procedures supplemented with follow-up radiographic evidence. RESULTS: The BESS technique facilitated meticulous clearance of the defect site, coupled with bone grafting and cannulated screw fixation, effectively addressing lumbar spondylolysis through a minimally invasive approach. This method holds promise for achieving substantial osseous fusion at the vertebral pars interarticularis defect site. CONCLUSION: The BESS procedure for lumbar spondylolysis ensures a clean and prepared defect site for grafting and encourages successful osseous fusion, spotlighting its potential as a viable surgical strategy in managing this condition.

Factors associated with non-fusion after direct pars repair of lumbar spondylolysis with pedicle screw and lamina hook: a clinical and CT-assessed study.

BACKGROUND: Pedicle screw and lamina hook (PSLH) technique is an effective and popular method for direct pars repair of lumbar spondylolysis. There is a lack of studies to explore factors that may influence the healing of spondylolysis after direct pars repair surgery. The present study aimed to investigate the factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PSLH technique. METHODS: A total of 55 subjects (average age 21.1 ± 6.3 years, a total of 120 pars defects) diagnosed with symptomatic spondylolysis and underwent pars repair surgery with PSLH were followed up and their clinical data were analyzed. Subjects were divided into a non-fusion group and fusion group according to whether the pars defect had bony fusion at last follow-up assessed by CT. Radiographic data, data related to spondylolysis and clinical outcomes were collected and compared between groups. RESULTS: The mean follow-up time of the 55 patients was 24.8 ± 12.0 (12-64) months. Among the 120 pars defects, 101 defects were successfully fused and 19 were not fused according to CT. The fusion rate was 84.2%. Multivariable logistic regression analysis showed the factors correlated with non-fusion after pars repair surgery: whether the spondylolysis segment was associated with spina bifida occulta (SBO) (P = 0.001), stage of the defect (P = 0.047), width of the defect (P = 0.002), and disc degeneration (P = 0.014). CONCLUSION: Direct pars repair by PSHL is a reliable treatment for lumbar spondylolysis with a fusion rate of 84.2%. Association with SBO of the spondylolysis segment, a terminal stage of the defect, a wider defect gap, and grade III disc degeneration may be factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PLSH. Non-fusion patients after pars repair appear to have worse clinical results compared to fusion patients.

Characteristics of lumbar spondylolysis: L5 versus non-L5.

BACKGROUND: Fifth lumbar vertebra (L5) spondylolysis has a lower bone union rate than non-L5 spondylolysis, but the reason for this is unknown. This study aimed to evaluate the differences in patient and lesion characteristics between L5 and non-L5 spondylolysis. METHODS: A total of 410 patients with lumbar spondylolysis aged 18 years or younger who were treated conservatively were enrolled. Patients and lesions were divided into L5 and non-L5 (L2-L4) spondylolysis. Factors, including sex, age, presence of spina bifida occulta, stage of the main side lesion, whether the lesion was unilateral or bilateral, presence and stage of the contralateral side lesion and treatment duration, were evaluated at the first visit and compared between the two groups. RESULTS: A total of 250 patients with 349 lesions were included. The bone union rate of L5 lesions was lower than that of non-L5 lesions (75% vs. 86%, p = 0.015). Patients with L5 spondylolysis were more likely to be male (86% vs. 66%) and younger (14.0 vs. 14.6 years) than patients with non-L5 spondylolysis. Lesions of L5 spondylolysis were more likely to be in a progressive stage (28% vs. 15%), less likely to be in a pre-lysis stage (28% vs. 43%) and more likely to be in a contralateral terminal stage (14% vs. 5.3%, p = 0.013) compared with lesions of non-L5 spondylolysis. CONCLUSIONS: L5 spondylolysis was characterised by a lower bone union rate, more males, younger age, more progressive stage and more contralateral pseudarthrosis than non-L5 spondylolysis.

L4/5 Disc Herniation: Not Unusually Accompanied with L5/S1 Low-Grade Spondylolytic Spondylolisthesis.

OBJECTIVE: Isthmic spondylolisthesis (IS) is distinguished by a congenital defect or acquired fracture of the pars interarticularis. Numerous studies on L5 low-grade IS have been carried out; however, there is a paucity of data regarding the condition of L5 IS concomitant with L4/5 disc herniation. This study aimed to identify the incidence rate and to illustrate the possible risk factors for L4/5 disc herniation in L5 low-grade IS patients. METHODS: A total of 268 consecutive patients diagnosed as L5/S1 low-grade IS between May 2017 and May 2022 were retrospectively enrolled in this study. Depending on the presence of L4/5 disc herniation or not, patients were divided into an L4/5 disc herniation group (L4/5 DH) and an L4/5 non-disc herniation group (L4/5 non-DH). Radiographic parameters were measured, and the ratios of L4-S1 segmental lordosis (SL) to lumbar lordosis (LDI), L4 inferior endplate (IEP) to L5 superior endplate (SEP) (L4 IEP/L5 SEP), and L5 IEP to S1 SEP (L5 IEP/S1 SEP) were compared between groups. The Pfirrmann grade of the L4/5 disc and the L5/S1 disc, and Roussouly classifications of each patient were also recorded. Univariate analysis (including independent-samples t-test and χ2 -test) and multiple logistic regression analysis were performed to analyze the data. RESULTS: There were 40 patients (14.9%) in the L4/5 DH group. The Roussouly classification differed significantly between groups. As demonstrated by the Pfirrmann grade, the L4/5 DH group showed more advanced disc degeneration at L4/5 than the L4/5 non-DH group. In contrast to the L4/5 non-DH group, the L4/5 DH group had a significantly larger L4 IEP, L4 IEP/L5 SEP, S1 SEP, and LDI while smaller L4/5 disc angle, L4/5 disc height, slip percentage, lumbar lordosis, and sacral slope. Multivariate logistic regression analysis revealed that higher L4/5 disc Pfirrmann grade (p = 0.004), decreased L4/5 disc height (p < 0.001), and lower L5 slip percentage (p = 0.022) were significantly associated with the occurrence of L4/5 DH. CONCLUSIONS: L4/5 disc herniation is not unusually accompanied by L5/S1 low-grade IS. Advanced L4/5 disc degeneration, decreased L4/5 disc height, and lower L5 slip percentage might be significantly associated with L4/5 disc herniation.

Direct Repair of Symptomatic Lumbar Spondylolysis Using Rod-Screw-Cable System.

OBJECTIVE: To assess the efficacy of a new direct lysis repair technique using internal fixation with rod, screws, and Songer cable in symptomatic lumbar spondylolysis. METHODS: Between December 2015 and January 2020, patients who were diagnosed with symptomatic lumbar spondylolysis and surgically treated with a rod-screw-cable system were recruited. Pedicle screwing by the Magerl technique was performed in all included patients, followed by direct lysis repair with bone allograft and demineralized bone matrix by stabilizing the posterior lamina and spinous process using a rod-screw-cable system. Clinical outcome was measured using the visual analog scale and Oswestry disability index preoperatively and 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. RESULTS: Sixteen patients were included in this study-11 men and 5 women (mean age: 47 years; range, 26-67 years). The lytic defects were at L4 and L5 in 6 and 10 patients, respectively. The mean follow-up period was 41 months (24-62 months). The visual analog scale values were 7.3, 6.1, 4.3, 3.3, 2.1, and 1.9 preoperatively and 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively, respectively. The Oswestry disability index values were 59.8%, 55.4%, 41.7%, 32.4%, 21.1%, and 16.9% for the same periods, respectively. No patient had an increase in the slip after surgery. There were no significant complications such as implant failure. CONCLUSIONS: Our technique provides rigid intra-segmental repair of spondylolysis without intersegmental motion interference, even if the patient is older or has disc degeneration.

L5 spondylolysis: Anatomical study comparing healed and unhealed lesions.

The anatomy and pathogenesis of spondylolysis has been widely studied; however, the microanatomy of spondylolysis of the lumbar vertebra has not been well described. Therefore, we aim to better elucidate this anatomy. Twenty dry bone specimens of healed and unhealed spondylolysis of the L5 vertebra were collected from human skeletal remains. Twelve L5 vertebrae were examples of unhealed spondylolysis and eight specimens exhibited a healed (i.e., bony fusion of the lesion) spondylolysis lesion. The specimens underwent macro and microanatomical analysis followed by CT and microCT imaging. Finally, selected healed and unhealed lesions were submitted for histological analysis using Mason Trichrome staining. The pars interarticularis of two L5 vertebrae without signs of healed/unhealed spondylolysis were evaluated histologically as controls. Of the 12 unhealed L5 pars defects, three were unilateral on left side. Of the eight healed pars defects, all were unilateral and seven of these were on left sides. One unilateral pars defect also had spina bifida occulta. Both on imaging and histological analysis, healed pars defects were only so superficially and not at deeper levels. Histologically, unhealed edges were made up of dense cortical bone while healed edges were made up primarily of trabecular bone. Based on our anatomical findings, the so-called healed spondylolysis lesions, although externally fused, are not thoroughly fused internally. Moreover, the anterior and posterior edges of the unhealed spondylosysis lesions are irregular and show signs of long-term disarticulation. Taken together, these data suggest that such 'healed' lesions might not be as stable as the normal L5 pars interarticularis.

T1-VIBE and STIR MRI of lumbar pars interarticularis injuries in elite athletes: fracture characterisation and potential prognostic indicators.

OBJECTIVES: To assess how pars interarticularis fracture characteristics on T1-VIBE and STIR MRI relate to healing and identify anatomical parameters that may impact healing. MATERIALS AND METHODS: A retrospective review of an MRI series of lumbar pars interarticularis injuries in elite athletes over a 3-year period. Fracture configurations, signal intensities and anatomical parameters were recorded by two radiologists. Statistical analysis employed multilevel mixed-effects linear regressions, adjusted for repeated measures and baseline covariates. RESULTS: Forty-seven lumbar pars interarticularis injuries among 31 athletes were assessed. On final scans for each athlete, 15% (7/47) injuries had worsened, 23% (11/47) remained stable, 43% (20/47) partially healed and 19% (9/47) healed completely. Healing times varied, quickest was 49 days for a chronic fracture in a footballer. Bone marrow oedema signal was highest in worsened fractures, followed by improved, and lowest in stable fractures. As healing progressed, T1-VIBE signal at the fracture line decreased. Bone marrow oedema and fracture line signal peaked at 90-120 days before decreasing until 210-240 days. Fractures with smaller dimensions, more vertical orientation and a longer superior articular facet beneath were significantly associated with better healing (p < 0.05). CONCLUSION: Most diagnosed athletic pars interarticularis injuries improve. Normalising T1-VIBE signal at the fracture line is a novel measurable indicator of bony healing. Contrastingly, bone marrow oedema signal is higher in active fractures irrespective of healing or deterioration. Injuries initially perceived as worsening may be exhibiting the normal osteoclastic phase of healing. Better outcomes favour smaller, vertical fractures with a longer superior articular facet beneath.

Comparing the Wiltse approach and classical approach of pedicle screw and hook internal fixation system for direct repair of lumbar spondylolysis in young patients: A case-control study.

The aim of this study was to investigate the clinical effect of direct isthmus repair via Wiltse approach and classical approach in the treatment of simple lumbar spondylolysis in young patients. Thirty-three patients with simple lumbar spondylolysis underwent direct isthmic repair via the Wiltse approach (n = 17) or the classical approach (n = 16). The operation time, intraoperative blood loss, postoperative drainage volume, hospital stay, fusion rate, visual analogue scale (VAS), and the Oswestry disability index were evaluated and compared between the 2 groups. The amount of intraoperative blood loss, postoperative drainage volume, and the duration of hospital stay in the Wiltse group were lower than those in the classical group (P < .05). There was no significant difference in Oswestry disability index score between the Wiltse group and the classical group at 3 months, 6 months, and 1 year after operation, but the visual analogue scale score in the Wiltse group was lower than that in the classical group at 6 months after surgery (P < .05). The Wiltse approach was comparable to the classical approach in terms of bone graft fusion time and fusion rate. The Wiltse approach for isthmus repair can achieve the same or even better clinical effect than the classical approach, and the Wiltse approach is more minimally invasive. Pedicle screw-hook internal fixation system combined with autogenous iliac bone graft via Wiltse approach is a feasible, safe, and effective minimally invasive surgical method for the repair of isthmic spondylolysis in young patients.

Optimal cutoff point of vertebral body cross-sectional area as a morphological parameter for predicting lumbar spondylolysis.

The relationship between vertebral body cross-sectional area (VBCSA) and spinal conditions associated with increased lumbar lordosis, such as lumbar spondylolysis (LSL), is not known. We investigated the morphological parameter, VBCSA, to predict LSL. The VBCSA on MRI has not been studied for its association with LSL. We hypothesized that VBCSA is an important morphological parameter for LSL prediction. We collected VBCSA data from 90 patients (43 males and 47 females) with LSL and 91 control subjects (44 males and 47 females) who underwent lumbar spine magnetic resonance imaging (LS-MRI). Axial T2-weighted LS-MRI images were obtained from all participants. Using our picture archiving and communications system, we analyzed the VBCSA at the level of the L5 vertebral body by utilizing MRI. The average VBCSA was 2263.51 ±â€…306.02 mm2 in the male control group and 1820.92 ±â€…224.89 mm2 in the male LSL group. LSL patients had significantly lower VBCSAs (P < .001) than did the male controls. The average VBCSA was 1985.21 ±â€…258.05 mm2 in the female control group and 1553.73 ±â€…250.02 mm2 in the female LSL group, and the LSL patients also had significantly lower VBCSAs (P < .001) than did the female controls. The optimal VBCSA cutoff value in the male group was 2014.69 mm2 with 76.7% sensitivity, 75.0% specificity, and an area under the receiver operating curve (AUC) of 0.89 (95% CI: 0.82-0.95). In the female group, the optimal cutoff score was 1814.11 mm2 with 76.6% sensitivity, 76.6% specificity, and an AUC of 0.88 (95% CI: 0.82-0.95). VBCSA is a sensitive objective morphological parameter for assessing LSL, and a lower VBCSA is associated with a higher possibility of LSL. We believe that these results will be useful in diagnostic radiology for evaluating patients with LSL.

Incidence of lumbar spondylolysis in athletes with low back pain: A systematic evaluation and single-arm meta-analysis.

BACKGROUND: Low back pain (LBP) is a common chief complaint from athletes. Lumbar spondylolysis (LS) is a common sport injury. Severe LS is likely to cause spinal instability, resulting in lumbar spondylolisthesis or lumbar disc herniation, and even damage to the spinal nerve roots. The incidence of LS is approximately 5% in the adult population, and nearly half of young athletes with LBP are diagnosed with LS. This meta-analysis analyzed the incidence of LS in athletes with LBP. METHODS: PubMed, Embase, Cochrane (Cochrane Central Register of Controlled Trials), and Web of Science databases were systematically searched for published case report and retrospective analyses related to the topic from the date of database creation to January 1,2023. Relevant literature was screened and information extracted, and risk of bias was assessed for included studies using the methodological index for non-randomized-studies scale. Single-arm Meta-analysis was performed using R4.04 software. Heterogeneity was quantified by Cochran Q test and Higgins I2. Funnel plots were used to visualize publication bias, and Egger test and Begg test were used to statistical tests. RESULTS: A total of 9 studies (835 patients) were included in this study. Meta-analysis revealed that the prevalence of LS in athletes with LBP was estimated at 41.7%, [95% CI = (0.28-0.55)], but this prevalence varied considerably with the gender and age of the athletes. CONCLUSION: The estimated prevalence of LS in athletes with LBP is 41.7%, and future correlations between the prevalence of LS in adolescent athletes worldwide need to be assessed from different perspectives, including biomechanical, hormonal, anatomical, behavioral, and gender differences.

Deep-Learning-Aided Evaluation of Spondylolysis Imaged with Ultrashort Echo Time Magnetic Resonance Imaging.

Isthmic spondylolysis results in fracture of pars interarticularis of the lumbar spine, found in as many as half of adolescent athletes with persistent low back pain. While computed tomography (CT) is the gold standard for the diagnosis of spondylolysis, the use of ionizing radiation near reproductive organs in young subjects is undesirable. While magnetic resonance imaging (MRI) is preferable, it has lowered sensitivity for detecting the condition. Recently, it has been shown that ultrashort echo time (UTE) MRI can provide markedly improved bone contrast compared to conventional MRI. To take UTE MRI further, we developed supervised deep learning tools to generate (1) CT-like images and (2) saliency maps of fracture probability from UTE MRI, using ex vivo preparation of cadaveric spines. We further compared quantitative metrics of the contrast-to-noise ratio (CNR), mean squared error (MSE), peak signal-to-noise ratio (PSNR), and structural similarity index (SSIM) between UTE MRI (inverted to make the appearance similar to CT) and CT and between CT-like images and CT. Qualitative results demonstrated the feasibility of successfully generating CT-like images from UTE MRI to provide easier interpretability for bone fractures thanks to improved image contrast and CNR. Quantitatively, the mean CNR of bone against defect-filled tissue was 35, 97, and 146 for UTE MRI, CT-like, and CT images, respectively, being significantly higher for CT-like than UTE MRI images. For the image similarity metrics using the CT image as the reference, CT-like images provided a significantly lower mean MSE (0.038 vs. 0.0528), higher mean PSNR (28.6 vs. 16.5), and higher SSIM (0.73 vs. 0.68) compared to UTE MRI images. Additionally, the saliency maps enabled quick detection of the location with probable pars fracture by providing visual cues to the reader. This proof-of-concept study is limited to the data from ex vivo samples, and additional work in human subjects with spondylolysis would be necessary to refine the models for clinical use. Nonetheless, this study shows that the utilization of UTE MRI and deep learning tools could be highly useful for the evaluation of isthmic spondylolysis.

Staphylococcal enterotoxin C as a novel strategy for treating lumbar spondylolysis in adolescents: Description of technique.

Lumbar spondylolysis is one of the most common causes of low back pain and primarily affects children and adolescents. Traditional posterior lumbar fixation and interbody fusion surgery has always been the most effective method to treat spondylolysis. However, traditional surgical management has limitations of large trauma, complex operation, high cost, postoperative biomechanical deterioration, and resulting complications. In order to avoid the trauma and complications of surgical treatment, and reduce the cost of treatment. Based on the successful clinical experience of using staphylococcal enterotoxin C (SEC) to treat nonunion after a limb fracture, we identified a minimally invasive method to effectively treat lumbar spondylolysis. A novel minimally invasive therapeutic approach is presented herein of an SEC injection guided by C-arm fluoroscopy to treat lumbar spondylolysis. We describe a novel technique applied in a patient with lumbar spondylolysis, who showed significantly improved low back pain symptoms and a computed tomography scan, including osseous fusion of the bilateral isthmus at L4 after SEC therapy. This is the first reported case description of using an SEC injection to treat lumbar spondylolysis with a successful clinical outcome.

Endoscopic-assisted fusion for lumbar pars fracture repair in an adolescent patient.

Minimally invasive repair of pars defects can be achieved via means of cannulation followed by tubular decortication. Given these injuries typically occur in pediatric and adolescent patients, minimal disruption to surrounding tissue during the repair is ideal. The use of an endoscopic approach to assist with repair and fusion across the pars defect is a novel consideration in the pediatric demographic, and in this case report we highlight our experience and rationale for this in treating a 14-year-old male athlete with lumbar 5 pars fracture. Radiographic evidence of bony fusion was seen by the third postoperative month. In this case report we demonstrate the invasive nature of this repair can be minimized further than current convention with successful radiographic and clinical outcomes.