Bone marrow stromal cells in Modic type 1 changes promote neurite outgrowth

The pain in patients with Modic type 1 changes (MC1) is often due to vertebral body endplate pain, which is linked to abnormal neurite outgrowth in the vertebral body and adjacent endplate. The aim of this study was to understand the role of MC1 bone marrow stromal cells (BMSCs) in neurite outgrowth. BMSCs can produce neurotrophic factors, which have been shown to be pro-fibrotic in MC1, and expand in the perivascular space where sensory vertebral nerves are located. The study involved the exploration of the BMSC transcriptome in MC1, co-culture of MC1 BMSCs with the neuroblastoma cell line SH-SY5Y, analysis of supernatant cytokines, and analysis of gene expression changes in co-cultured SH-SY5Y. Transcriptomic analysis revealed upregulated brain-derived neurotrophic factor (BDNF) signaling-related pathways. Co-cultures of MC1 BMSCs with SH-SY5Y cells resulted in increased neurite sprouting compared to co-cultures with control BMSCs. The concentration of BDNF and other cytokines supporting neuron growth was increased in MC1 vs. control BMSC co-culture supernatants. Taken together, these findings show that MC1 BMSCs provide strong pro-neurotrophic cues to nearby neurons and could be a relevant disease-modifying treatment target.

Development and evaluation of robot-assisted ultrasound navigation system for pedicle screw placement: An ex-vivo animal validation

PURPOSE

Spinal instrumentation with pedicle screw placement (PSP) is an important surgical technique for spinal diseases. Accurate screw trajectory is a prerequisite for PSP. Ultrasound (US) imaging with robot-assisted system forms a non-radiative alternative to provide precise screw trajectory. This study reports on the development and assessment of US navigation for this application.

METHODS

A robot-assisted US reconstruction was proposed and an automatic CT-to-US registration algorithm was investigated, allowing the registration of screw trajectories. Experiments were conducted on ex-vivo lamb spines to evaluate system performance.

RESULTS

In total, 72 screw trajectories are measured, displaying an average position accuracy of 2.80 ± 1.14 mm and orientation accuracy of 1.38 ± 0.61°.

CONCLUSION

The experimental results demonstrate the feasibility of proposed US system. This work, although restricted to laboratory settings, encourages further exploration of the potential of this technology in clinical practice.

Automatic breach detection during spine pedicle drilling based on vibroacoustic sensing

Pedicle drilling is a complex and critical spinal surgery task. Detecting breach or penetration of the surgical tool to the cortical wall during pilot-hole drilling is essential to avoid damage to vital anatomical structures adjacent to the pedicle, such as the spinal cord, blood vessels, and nerves. Currently, the guidance of pedicle drilling is done using image-guided methods that are radiation intensive and limited to the preoperative information. This work proposes a new radiation-free breach detection algorithm leveraging a non-visual sensor setup in combination with deep learning approach. Multiple vibroacoustic sensors, such as a contact microphone, a free-field microphone, a tri-axial accelerometer, a uni-axial accelerometer, and an optical tracking system were integrated into the setup. Data were collected on four cadaveric human spines, ranging from L5 to T10. An experienced spine surgeon drilled the pedicles relying on optical navigation. A new automatic labeling method based on the tracking data was introduced. Labeled data was subsequently fed to the network in mel-spectrograms, classifying the data into breach and non-breach. Different sensor types, sensor positioning, and their combinations were evaluated. The best results in breach recall for individual sensors could be achieved using contact microphones attached to the dorsal skin (85.8%) and uni-axial accelerometers clamped to the spinous process of the drilled vertebra (81.0%). The best-performing data fusion model combined the latter two sensors with a breach recall of 98%. The proposed method shows the great potential of non-visual sensor fusion for avoiding screw misplacement and accidental bone breaches during pedicle drilling and could be extended to further surgical applications.

Prognostic value of clinical and MRI features in the screening of lipomatous lesions

BACKGROUND AND OBJECTIVES

Differentiation of lipomatous tumors mostly requires diagnostic biopsy but is essential to decide for the most adequate therapy. This study aims to investigate the prognostic value of available clinical and radiological features with regard to malignancy of the lesion, recurrence and survival.

METHODS

In this retrospective cohort study, 104 patients with a biopsy-proven lipomatous tumor between 2010 and 2015 and a minimum clinical follow-up of two years were enrolled. Next to clinical features (age, gender, location of the lesion, histopathologic diagnosis, stage of disease, time to recurrence and death), MRI parameters were recorded retrospectively and blinded to the histological diagnosis.

RESULTS

Malignant lipomatous tumors were associated with location in the lower extremities and MRI features like thick septation (>2 mm), presence of a non-adipose mass, foci of high T2/STIR signal and contrast agent enhancement. A non-adipose mass was a predictor for recurrence and inferior overall survival, while lesions with high T2/STIR signal showed higher risk of recurrence only. In combination, clinical and radiological features (lower extremities, septation > 2 mm, existence of non-adipose mass, contrast enhancement, and foci of high T2/STIR signal) predicted a malignant lipomatous tumor with an accuracy of 0.941 (95% CI of 0.899-0.983; 87% sensitivity, 86% specificity).

CONCLUSION

Localization and characteristic MR features predict malignancy in most lipomatous lesions. Non-adipose masses are a poor prognostic factor, being associated with tumor recurrence and disease-related death.

Robot-assisted ultrasound reconstruction for spine surgery: from bench-top to pre-clinical study

PURPOSE

Robot-assisted ultrasound (rUS) systems have already been used to provide non-radiative three-dimensional (3D) reconstructions that form the basis for guiding spine surgical procedures. Despite promising studies on this technology, there are few studies that offer insight into the robustness and generality of the approach by verifying performance in various testing scenarios. Therefore, this study aims at providing an assessment of a rUS system, with technical details from experiments starting at the bench-top to the pre-clinical study.

METHODS

A semi-automatic control strategy was proposed to ensure continuous and smooth robotic scanning. Next, a U-Net-based segmentation approach was developed to automatically process the anatomic features and derive a high-quality 3D US reconstruction. Experiments were conducted on synthetic phantoms and human cadavers to validate the proposed approach.

RESULTS

Average deviations of scanning force were found to be 2.84±0.45 N on synthetic phantoms and to be 5.64±1.10 N on human cadavers. The anatomic features could be reliably reconstructed at mean accuracy of 1.28±0.87 mm for the synthetic phantoms and of 1.74±0.89 mm for the human cadavers.

CONCLUSION

The results and experiments demonstrate the feasibility of the proposed system in a pre-clinical setting. This work is complementary to previous work, encouraging further exploration of the potential of this technology in in vivo studies.

Role of C-reactive protein in the bone marrow of Modic type 1 changes

Modic type 1 changes (MC1) are vertebral bone marrow lesions and associate with low back pain. Increased serum C-reactive protein (CRP) has inconsistently been associated with MC1. We aimed to provide evidence for the role of CRP in the tissue pathophysiology of MC1 bone marrow. From 13 MC1 patients undergoing spinal fusion at MC1 levels, vertebral bone marrow aspirates from MC1 and intrapatient control bone marrow were taken. Bone marrow CRP, interleukin (IL)-1, and IL-6 were measured with enzyme-linked immunosorbent assays; lactate dehydrogenase (LDH) was measured with a colorimetric assay. CRP, IL-1, and IL-6 were compared between MC1 and control bone marrow. Bone marrow CRP was correlated with blood CRP and with bone marrow IL-1, IL-6, and LDH. CRP expression by marrow cells was measured with a polymerase chain reaction. Increased CRP in MC1 bone marrow (mean difference: +0.22 mg CRP/g, 95% confidence interval [CI] [-0.04, 0.47], p = 0.088) correlated with blood CRP (r = 0.69, p = 0.018), with bone marrow IL-1β (ρ = 0.52, p = 0.029) and IL-6 (ρ = 0.51, p = 0.031). Marrow cells did not express CRP. Increased LDH in MC1 bone marrow (143.1%, 95% CI [110.7%, 175.4%], p = 0.014) indicated necrosis. A blood CRP threshold of 3.2 mg/L detected with 100% accuracy increased CRP in MC1 bone marrow. In conclusion, the association of CRP with inflammatory and necrotic changes in MC1 bone marrow provides evidence for a pathophysiological role of CRP in MC1 bone marrow.

Modic type 2 changes are fibroinflammatory changes with complement system involvement adjacent to degenerated vertebral endplates

Background

Vertebral endplate signal intensity changes visualized by magnetic resonance imaging termed Modic changes (MC) are highly prevalent in low back pain patients. Interconvertibility between the three MC subtypes (MC1, MC2, MC3) suggests different pathological stages. Histologically, granulation tissue, fibrosis, and bone marrow edema are signs of inflammation in MC1 and MC2. However, different inflammatory infiltrates and amount of fatty marrow suggest distinct inflammatory processes in MC2.

Aims

The aims of this study were to investigate (i) the degree of bony (BEP) and cartilage endplate (CEP) degeneration in MC2, (ii) to identify inflammatory MC2 pathomechanisms, and (iii) to show that these marrow changes correlate with severity of endplate degeneration.

Methods

Pairs of axial biopsies (n = 58) spanning the entire vertebral body including both CEPs were collected from human cadaveric vertebrae with MC2. From one biopsy, the bone marrow directly adjacent to the CEP was analyzed with mass spectrometry. Differentially expressed proteins (DEPs) between MC2 and control were identified and bioinformatic enrichment analysis was performed. The other biopsy was processed for paraffin histology and BEP/CEP degenerations were scored. Endplate scores were correlated with DEPs.

Results

Endplates from MC2 were significantly more degenerated. Proteomic analysis revealed an activated complement system, increased expression of extracellular matrix proteins, angiogenic, and neurogenic factors in MC2 marrow. Endplate scores correlated with upregulated complement and neurogenic proteins.

Discussion

The inflammatory pathomechanisms in MC2 comprises activation of the complement system. Concurrent inflammation, fibrosis, angiogenesis, and neurogenesis indicate that MC2 is a chronic inflammation. Correlation of endplate damage with complement and neurogenic proteins suggest that complement system activation and neoinnervation may be linked to endplate damage. The endplate-near marrow is the pathomechanistic site, because MC2 occur at locations with more endplate degeneration.

Conclusion

MC2 are fibroinflammatory changes with complement system involvement which occur adjacent to damaged endplates.

Intraoperative tissue classification methods in orthopedic and neurological surgeries: A systematic review

Accurate tissue differentiation during orthopedic and neurological surgeries is critical, given that such surgeries involve operations on or in the vicinity of vital neurovascular structures and erroneous surgical maneuvers can lead to surgical complications. By now, the number of emerging technologies tackling the problem of intraoperative tissue classification methods is increasing. Therefore, this systematic review paper intends to give a general overview of existing technologies. The review was done based on the PRISMA principle and two databases: PubMed and IEEE Xplore. The screening process resulted in 60 full-text papers. The general characteristics of the methodology from extracted papers included data processing pipeline, machine learning methods if applicable, types of tissues that can be identified with them, phantom used to conduct the experiment, and evaluation results. This paper can be useful in identifying the problems in the current status of the state-of-the-art intraoperative tissue classification methods and designing new enhanced techniques.

Acromioclavicular joint stabilization with a double cow-hitch technique compared to a double tight-rope: a biomechanical study

INTRODUCTION

The aim of the present biomechanical study was to evaluate the stability of a novel simple and cost-effective mini-open double cow-hitch suture button technique of acromioclavicular (AC) joint stabilization in comparison to a well-established double tight-rope technique.

MATERIALS AND METHODS

A total of 12 fresh-frozen cadaveric shoulders were randomized into two treatment groups. In either a coracoclavicular stabilization with a standard double tight-rope technique (Group 1; n = 6, age 78 years ± 10) or a double cow-hitch with two No. 5 FiberWire strains looped in a bicortical button placed at the bottom of the coracoid process (Group 2; n = 6, age 80 years ± 13). Both techniques were equally augmented with an AC joint cerclage using a FiberTape. All shoulders were tested in a servo-hydraulic material testing machine for elongation/cyclic displacement (in mm) after cyclic loading (70 N cyclical load, 1500 cycles), stiffness (N/mm) and ultimate load to failure (N). The mechanism of failure was recorded. All tests were performed in a previously published testing setup.

RESULTS

After 1500 cycles, group 2 showed a cyclic displacement of 1.67 mm (SD 0.85), compared to 1.04 mm (SD 0.23) cyclic displacement in group 1 (p = 0.11). The cyclic displacement after AC reconstruction in group 1 was 0.36 mm lower than in the native state with intact ligaments (p = 0.19), whereas the cyclic elongation in group 2 was 0.05 mm higher compared to the native situation (p = 0.87). Stiffness after reconstruction was significantly higher in group 1 compared to the native specimen (p = 0.001), in group 2 it was similar as before the reconstruction (p = 0.64). Ultimate load to failure and stiffness were higher in group 1 with 424 N (SD 237) and 68.6 N/mm (SD 8.2), compared to 377 N (SD 152) and 68 N/mm (SD 13.3) in group 2, without reaching statistical significance (p = 0.69 and 0.89). The most common failure modes were clavicular fractures at the tight rope drill holes (n = 2) and clavicular fractures medially at the fixation site (n = 2) in group 1, and coracoid button break-through (n = 3) and clavicular fractures medially at the fixation site (n = 2) in group 2.

CONCLUSIONS

Stabilization of the AC joint with a novel mini-open double cow-hitch suture button technique resulted in a similar low elongation, high stiffness and ultimate load to failure compared to a double tight-rope technique. This cost-effective technique for AC joint stabilization could demonstrate a sufficient biomechanical stability with especially high stiffness and load-to-failure.

LEVEL OF EVIDENCE

Biomechanical study.

A systematic analysis of preprints in Trauma & Orthopaedic surgery

Aims

Preprint servers allow authors to publish full-text manuscripts or interim findings prior to undergoing peer review. Several preprint servers have extended their services to biological sciences, clinical research, and medicine. The purpose of this study was to systematically identify and analyze all articles related to Trauma & Orthopaedic (T&O) surgery published in five medical preprint servers, and to investigate the factors that influence the subsequent rate of publication in a peer-reviewed journal.

Methods

All preprints covering T&O surgery were systematically searched in five medical preprint servers (medRxiv, OSF Preprints, Preprints.org, PeerJ, and Research Square) and subsequently identified after a minimum of 12 months by searching for the title, keywords, and corresponding author in Google Scholar, PubMed, Scopus, Embase, Cochrane, and the Web of Science. Subsequent publication of a work was defined as publication in a peer-reviewed indexed journal. The rate of publication and time to peer-reviewed publication were assessed. Differences in definitive publication rates of preprints according to geographical origin and level of evidence were analyzed.

Results

The number of preprints increased from 2014 to 2020 (p < 0.001). A total of 38.6% of the identified preprints (n = 331) were published in a peer-reviewed indexed journal after a mean time of 8.7 months (SD 5.4 (1 to 27)). The highest proportion of missing subsequent publications was in the preprints originating from Africa, Asia/Middle East, and South America, or in those that covered clinical research with a lower level of evidence (p < 0.001).

Conclusion

Preprints are being published in increasing numbers in T&O surgery. Depending on the geographical origin and level of evidence, almost two-thirds of preprints are not subsequently published in a peer-reviewed indexed journal after one year. This raises major concerns regarding the dissemination and persistence of potentially wrong scientific work that bypasses peer review, and the orthopaedic community should discuss appropriate preventive measures.

Cite this article: Bone Jt Open 2022;3(7):582–588.

Surgical Process Modeling for Open Spinal Surgeries

Modern operating rooms are becoming increasingly advanced thanks to the emerging medical technologies and cutting-edge surgical techniques. Current surgeries are transitioning into complex processes that involve information and actions from multiple resources. When designing context-aware medical technologies for a given intervention, it is of utmost importance to have a deep understanding of the underlying surgical process. This is essential to develop technologies that can correctly address the clinical needs and can adapt to the existing workflow. Surgical Process Modeling (SPM) is a relatively recent discipline that focuses on achieving a profound understanding of the surgical workflow and providing a model that explains the elements of a given surgery as well as their sequence and hierarchy, both in quantitative and qualitative manner. To date, a significant body of work has been dedicated to the development of comprehensive SPMs for minimally invasive baroscopic and endoscopic surgeries, while such models are missing for open spinal surgeries. In this paper, we provide SPMs common open spinal interventions in orthopedics. Direct video observations of surgeries conducted in our institution were used to derive temporal and transitional information about the surgical activities. This information was later used to develop detailed SPMs that modeled different primary surgical steps and highlighted the frequency of transitions between the surgical activities made within each step. Given the recent emersion of advanced techniques that are tailored to open spinal surgeries (e.g., artificial intelligence methods for intraoperative guidance and navigation), we believe that the SPMs provided in this study can serve as the basis for further advancement of next-generation algorithms dedicated to open spinal interventions that require a profound understanding of the surgical workflow (e.g., automatic surgical activity recognition and surgical skill evaluation). Furthermore, the models provided in this study can potentially benefit the clinical community through standardization of the surgery, which is essential for surgical training.

Long-term outcome of patients with adolescent idiopathic scoliosis seeking nonoperative treatment after a mean follow-up of 42 years

PURPOSE

Adolescent idiopathic scoliosis (AIS) affects up to 3% of otherwise healthy adolescents. The extreme long-term outcomes of nonoperative treatment are underreported. This study aimed to investigate the long-term outcome of nonoperative-treated AIS patients. Comparison between a bracing and an observation approach were performed.

METHODS

In a retrospective cohort study, 20 nonoperatively treated AIS patients were observed concerning patient-related outcome measures (PROM) (visual analog scale (VAS), Short Form Health Survey 36 item (SF 36), Scoliosis Research Society (SRS 24), Oswestry Low Back Pain Disability Index (ODI), Psychological General Well-Being Index (PGWBI)), radiological curve progression and health-related quality of life (HRQoL). Baseline characteristics and radiological imaging were collected. At follow-up, anteroposterior and lateral X-rays as well as questionnaires were analyzed.

RESULTS

Twenty patients (16 females, mean age: 14.6 ± 3.2 years) with a follow-up time of 42 ± 9 years were included. Nine patients (initial Cobb 35° ± 19°) were treated with bracing for a mean time of 26 ± 9 months, while the other 11 patients (initial Cobb 29° ± 11°) were observed. The primary curve progressed from 32° ± 15° to 52° ± 25° in average with no significant difference between the cohorts (p = 0.371). At final follow-up, a mean ODI score of 7 ± 7.9 points with no difference depending on the treatment (p = 0.668) was seen. No significant differences were observed for PROMs. Curve magnitude correlated neither at diagnosis (p = 0.617) nor at follow-up (p = 0.535) with the ODI score at final follow-up.

CONCLUSION

After a mean of 42 years, patients with nonoperative treatment of moderate AIS demonstrated a good clinical outcome despite progression of the deformity.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Risk factor analysis for above-knee amputation in patients with periprosthetic joint infection of the knee: a case-control study

Background

Periprosthetic joint infection (PJI) is a severe complication following knee arthroplasty. Therapeutic strategies comprise a combination of surgical and antibiotic treatment modalities and aim to eradicate the infection. Sometimes control of the disease can only be attained by above-knee amputation (AKA). While a vast amount of literature exists illuminating predisposing factors for PJI, risk factors favoring the endpoint AKA in this context are sparsely known.

Methods

The purpose of this investigation was to delineate whether patients with PJI of the knee present specific risk factors for AKA. In a retrospective case-control study 11 cases of PJI treated with AKA were compared to 57 cases treated with limb salvage (LS). The minimum follow-up was 2 years. Comorbidities, signs and symptoms of the current infection, factors related to previous surgeries and the implant, microbiology, as well as therapy related factors were recorded. Comparative analysis was performed using student’s t-test, chi-square test or Fisher’s exact test. Binary differences were calculated using odds ratio (OR). Reoperation frequency was compared using Mann-Whitney U test. In-depth descriptive analysis of 11 amputees was carried out.

Results

A total of 68 cases aged 71 ± 11.2 years were examined, 11 of which underwent AKA and 57 had LS. Severe comorbidities (p = 0.009), alcohol abuse (p = 0.015), and preoperative anemia (p = 0.022) were more frequently associated with AKA. Preoperative anemia was found in all 11 amputees (100%) and in 33 of 57 LS patients (58%) with an average preoperative hemoglobin of 99.9 ± 15.1 g/dl compared to 118.2 ± 19.9 g/dl (p = 0.011). No other parameters differed significantly. AKA patients underwent a median of eight (range 2–24) reoperations, LS patients a median of five (range 2–15).

Conclusion

Factors potentially influencing the outcome of knee PJI are diverse. The indication of AKA in this context remains a rarity and a case-by-case decision. Patient-intrinsic systemic factors such as alcohol abuse, severe comorbidities and preoperative anemia may elevate the individual risk for AKA in the setting of PJI. We recommend that anemia, being a condition well amenable to therapeutic measures, should be given special consideration in management of PJI patients.

Trial registration

This study was registered with Kantonale Ethikkommission Zürich, (BASEC-No. 2016–01048).

Disproportionate Case Reduction After Ban of Elective Surgeries During the SARS-CoV-2 Pandemic

STUDY DESIGN

This is a retrospective case analysis.

OBJECTIVE

The objective of this study was to illustrate the numerical effects of regulatory restrictions of elective surgery at an orthopaedic university hospital.

SUMMARY OF BACKGROUND DATA

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic all over the world places extraordinary demands on health care systems which are forced to ensure structural and personnel capacities. Consequently, hospitals may only perform urgent interventions. Spine patients, however, often need urgent surgery and, moreover, bear an above-average perioperative risk frequently requiring postoperative surveillance on intensive care units (ICUs). Facing this dilemma, we want to share our practice and its unexpected numerical effects.

METHODS

We compare case statistics during normal operation, directly before and after implementation of regulatory measures. We also analyzed the differences in ICU utilization, complexity and duration of interventions and the patient population.

RESULTS

Spine surgical interventions have been reduced by 42.7%. Regulatory restriction of "elective surgeries" in pandemic situations results in reduced ICU utilization, however in a disproportionate manner. Although other specialized surgeries can be reduced by 59%, surgical spine cases are only diminishable by 24%. The spine surgery-related ICU occupancy has been reduced by 35%.

CONCLUSION

The disproportionate effect of case reduction needs to be considered while calculating resources released by regulatory limitation of "elective surgeries" on a (inter-)national level.

Long-term Prognosis After Successful Nonoperative Treatment of Osteochondral Lesions of the Talus: An Observational 14-Year Follow-up Study

Background:

Little is known about the long-term prognosis of osteochondral lesions of the talus (OLTs) after nonoperative treatment.

Purpose:

To evaluate the clinical and radiological long-term results of initially successfully treated OLTs after a minimum follow-up of 10 years.

Study Design:

Case series; Level of evidence, 4.

Methods:

Between 1998 and 2006, 48 patients (50 ankles) with OLTs were successfully treated nonoperatively. These patients were enrolled in a retrospective long-term follow-up, for which 24 patients could not be reached or were available only by telephone. A further 2 OLTs (6%) that had been treated surgically were excluded from the analysis and documented as failures of nonoperative treatment. The final study group of 22 patients (mean age at injury, 42 years; range, 10-69 years) with 24 OLTs (mean size, 1.4 cm²; range, 0.2-3.8 cm²) underwent clinical and radiological evaluation after a mean follow-up of 14 years (range, 11-20 years). Ankle pain was evaluated with a visual analog scale (VAS), ankle function with the American Orthopaedic Foot and Ankle Society (AOFAS) score, and sports activity with the Tegner score. Progression of ankle osteoarthritis was analyzed based on plain ankle radiographs at the initial presentation and the final follow-up according to the Van Dijk classification.

Results:

At final follow-up, the 24 cases (ie, ankles) showed a median VAS score of 0 (IQR, 0.0-2.25) and a median AOFAS score of 94.0 (IQR, 85.0-100). Pain had improved in 18 cases (75%), was unchanged in 3 cases (13%), and had increased in 3 cases (13%). The median Tegner score was 4.0 (IQR, 3.0-5.0). Persistent ankle pain had led to a decrease in sports activity in 38% of cases. At the final follow-up, 11 cases (73%) showed no progression of ankle osteoarthritis and 4 cases (27%) showed progression by 1 grade.

Conclusion:

Osteochondral lesions of the talus that successfully undergo an initial nonoperative treatment period have minimal symptoms in the long term, a low failure rate, and no relevant ankle osteoarthritis progression. However, a decrease in sports activity due to sports-related ankle pain was observed in more than one-third of patients.

Cervical spine clearance after blunt trauma: current state of the art

No definite consensus exists for the clearance of the cervical spine (C-spine) after blunt trauma, despite many validated algorithms, recommendations and guidelines. We intend to answer the most relevant questions with which physicians are confronted when clearing C-spines after blunt trauma in emergency departments (EDs). To exclude significant C-spine injuries we designed an algorithm to be compatible with clinical practice, to simplify patient management and avoid unrewarding evaluation.

We conducted an exploratory PubMed search including articles published from January 2000 to October 2018. Keywords used were “cervical spine”, “injury”, “clearance”, “Canadian C-spine Rule”, “CCR” and “national emergency x-radiography utilization study”. Clinical and experimental studies were included in a detailed review.

We based our literature review on 33 articles. While answering fundamental triage questions from daily clinical practice, the current literature is discussed in detail. We designed an algorithm for the C-spine clearance suitable for any trauma centre with a high-quality multiplanar reconstruction computerized tomography (CT) scan continuously available.

The high sensitivity of the Canadian C-spine Rule (CCR) prevents missing C-spine injuries while limiting the amount of unnecessary radiologic examinations. Plain radiographs were fully abandoned for C-spine clearance. A negative CT scan is sufficient to clear the majority of C-spine injuries and allows for collar removal. In case of motor symptoms or radio-clinical discrepancy, the advice of a specialized spine surgeon must be requested. Magnetic resonance imaging must not be routinely used. Neck pain despite negative imaging is not a reason to delay removal of stiff cervical collars.

Cite this article: EFORT Open Rev 2020;5:253-259. DOI: 10.1302/2058-5241.5.190047

Feasibility of iliosacral screw placement in patients with upper sacral dysplasia

Background

Exact knowledge of the sacral anatomy is crucial for the percutaneous insertion of iliosacral screws. However, dysplastic anatomical patterns are common. In addition to a preoperative computed tomography (CT) analysis, conventional radiographic measures may help to identify upper sacral dysplasia and to avoid damage to surrounding structures. Aiming to further increase safety in percutaneous iliosacral screw placement in the presence of sacral dysmorphism, this study examined the prevalence of previously established radiographic signs and, in addition, defined the “critical SI angle” as a new radiographic criterion.

Methods

Pelvic CT scans of 98 consecutive trauma patients were analysed. Next to assessment of established signs indicating upper sacral dysplasia, the critical sacroiliac (SI) angle was defined in standardized pelvic outlet views.

Results

The critical SI angle significantly correlates with the presence of mammillary bodies and an intraarticular vacuum phenomenon. With a cut-off value of − 14.2°, the critical SI angle detects the feasibility of a safe iliosacral screw insertion in pelvic outlet views with a sensitivity of 85.9% and a specificity of 85.7%.

Conclusions

The critical SI angle can support the decision-making when planning iliosacral screw fixation. The clinical value of the established signs of upper sacral dysplasia remains uncertain.

Carbon fibre/polyether ether ketone (CF/PEEK) implants in orthopaedic oncology

Background

Radiation therapy is an important therapeutic element in musculoskeletal tumours, especially when encountering multiple or painful lesions. In osteolytic lesions, a surgical stabilization with implants is often required. However, metallic implants not only complicate the CT-based planning of a subsequent radiation therapy, but also have an uncontrollable dose-modulating effect in adjuvant radiotherapy. In addition, follow-up imaging and the diagnosis of local recurrences are often obscured by metallic artefacts. Radiolucent implants consisting of carbon/polyether ether ketone (CF/PEEK) therefore facilitate adjuvant radiation therapy and follow-up imaging of bone lesions. We hereby present clinical cases with application of CF/PEEK implants in orthopaedic tumour surgery.

Methods

We report a single-centre experience of three selected patients with surgical stabilization of osteolytic bone lesions using CF/PEEK implants. Detailed information about the clinical presentation, preoperative considerations, surgical procedures and postoperative results is provided for each case.

Results

One spinal lesion (T12 vertebral body), one lesion of the upper extremity (humerus) and one of the lower extremities (tibia) were surgically stabilized with use of CF/PEEK implants. With a mean follow-up of 12 months (range 6–25 months), no adverse events were observed. Two patients received adjuvant radiotherapy. Follow-up imaging was obtained in all patients.

Conclusion

The applicability of CF/PEEK implants in orthopaedic tumour surgery is good with respect to postoperative follow-up imaging, application of adjuvant radiotherapy and intraoperative handling. As a result of the unique material properties, oncological patients might particularly benefit from CF/PEEK implants.

Impact of graft and tunnel orientation on patient-reported outcome in anterior cruciate ligament reconstruction using bone-patellar tendon-bone autografts

Background

The optimal positioning of anterior cruciate ligament graft is still controversially discussed. We therefore wanted to determine the tunnel-to-joint (TJA), tunnel-to-shaft (TSA), and graft-tunnel divergence angles which would provide the best outcome, determined by the KOOS (Knee Injury and Osteoarthritis Outcome Score). This study evaluated the clinical influence of graft orientation as measured with the KOOS questionnaire in patients with anterior cruciate ligament reconstruction with bone-patellar tendon-bone autografts.

Methods

We designed a prospective cohort study, with a 1 ¼ year recruitment phase from March 2011 to July 2012 and a minimal follow-up period of 1 year. Inclusion criteria were patients ≥ 18 years of age receiving an ACL reconstruction with bone-patellar tendon-bone autografts at our institution after having suffered an acute ACL rupture. The primary outcome was the KOOS. Independent variables were patient age, gender, laterality of rupture, mechanism of trauma, and type of femoral and tibial fixation, as well as sagittal graft-tunnel divergence, TJA, and TSA, the latter two being assessed on coronal slices of magnetic resonance imaging. Equations modeling the relationship between TJA, TSA, and graft-tunnel divergence with the KOOS overall score were fitted, and the optimum angles were mathematically determined.

Results

In total, 31 patients were included in our study. Our cohort with a median age of 28 years was predominantly male. The mathematically determined optimal placement of the implant in the coronal plane was a TJA of 74.8°, a TSA of 80.1°, and a graft-tunnel divergence angle of 8.5°.

Conclusion

With regard to patient-reported outcome, the optimal graft orientation is provided by a coronal tunnel-to-shaft angle of 80° and tunnel-to-joint angle of 75°, respectively. Interestingly, in our series, patients reported best clinical outcomes with a sagittal graft-tunnel divergence. These results should be validated in larger studies.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-0954-3) contains supplementary material, which is available to authorized users.

Current concepts in locking plate fixation of proximal humerus fractures

Despite numerous available treatment strategies, the management of complex proximal humeral fractures remains demanding. Impaired bone quality and considerable comorbidities pose special challenges in the growing aging population. Complications after operative treatment are frequent, in particular loss of reduction with varus malalignment and subsequent screw cutout. Locking plate fixation has become a standard in stabilizing these fractures, but surgical revision rates of up to 25% stagnate at high levels. Therefore, it seems of utmost importance to select the right treatment for the right patient. This article provides an overview of available classification systems, indications for operative treatment, important pathoanatomic principles, and latest surgical strategies in locking plate fixation. The importance of correct reduction of the medial cortices, the use of calcar screws, augmentation with bone cement, double-plate fixation, and auxiliary intramedullary bone graft stabilization are discussed in detail.

[Sacroiliac joint pain - diagnostic algorithm and therapeutic approaches]

The sacroiliac joints are causative for 13-30% of cases with low back pain and are still disregarded in the differential diagnosis. This is mainly due to its complex anatomy and the variety of pain patterns originating from the SI joints. The broad etiology of low back pain often misleads the physician into inadequate treatments. This article reviews the clinical presentation of patients suffering from a sacroiliac arthropathy and points out therapeutic strategies. It also provides a helpful diagnostic tool in daily routine. Eventually, any patient needs to experience a significant pain reduction resulting from an intrarticular injection before the diagnosis of non-inflammatory SI arthropathy is confirmed. In most cases, nonoperative treatment measures are sufficient. Operative strategies are available in selected cases with unsuccessful conservative therapy.