Anatomic Image-Based Classification of Lumbar Intervertebral Disc Pathologies.

Introduction Several minimally invasive spine approaches and techniques have been developed in recent years. While the disease processes affecting the spinal motion segment have remained largely the same, the emerging technologies have changed treatment options radically and not necessarily in an organized fashion. The current diagnostic techniques, also evolving, have helped us appreciate the disease's pathoanatomy in minute details. A comprehensive classification method accounting for all anatomical variations in the disc disease, tailored to treatment options, is necessary. Such a classification will allow the surgeon to choose an appropriate surgical option in a consistent fashion. We feel that our classification system will help the spine surgeon make that important decision consistently, with minimal risk of leaving behind a significant lesion or disrupting an otherwise normal structure of the spinal motion segment. Furthermore, we feel such a comprehensive classification will help surgeons and other caregivers to standardize treatment approaches to the various presentations of disc disease, and apply the evolving technology in an organized fashion. Purpose To develop a comprehensive, treatment-orientated classification of the lumbar disc disease. Materials and Methods The literature was reviewed for the classification of disc disease. The morphology of the disc disease, the topography of the disc lesion, and the symptom-complex produced by the disc lesion are identified and graded. The features so identified and graded are placed in a matrix. The combinations of the anatomical features and symptoms are then computed as shown in the matrix. The MRI database held in the office was studied to determine the most frequent combinations of the disc disease and symptom complex. Results A total of 494 combinations were identified, but most have no clinical relevance. The retrospective study of the clinical data and MRI studies of 93 patients (50 male and 43 female) revealed the most affected motion-segment was L5-S1 (male = 19.3%, and female = 23.8%). The most common patho-anatomy is a globally bulging disc (T3L1), representing 37.6% of the total. The second most common combination is a degenerated disc with central, intra-annular tear T4L1), representing 20.4% of the total. At 11.8%, globally bulging with severe axial pain and moderate radicular pain represented the most common patho-anatomic/clinical classification (T3L1B4R2). The most frequent top 10 patho-anatomic/clinical classifications represented 15.5% of the total. Conclusion In light of the multiple surgical options for excision of the herniated lumbar disc, including the conventional and minimally invasive, and the fact that the imaging technology allows spine surgeons to see in great detail, the disease status of each of the components of the spinal motion segment, it is imperative to develop comprehensive classification systems which take account of the unique characteristics of the disease entity and guide treatment strategies. The classification system presented here is fairly complex, but the software technology will be utilized for the classification system along with the most appropriate treatment approach.

High therapeutic efficacy of artemether-lumefantrine and dihydroartemisinin-piperaquine for the treatment of uncomplicated falciparum malaria in Somalia.

BACKGROUND: Artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DHA/PPQ) are the recommended first- and second-line treatments, respectively, for uncomplicated falciparum malaria in Somalia. The studies reported here were conducted to assess the efficacy of these artemisinin-based combinations and the mutations in Plasmodium falciparum K13-propeller (Pfk13) domain and amplification in Pfplasmepsin 2 (Pfpm2) gene in Somalia. METHODS: One-arm prospective studies were conducted to assess the clinical and parasitological responses to DHA/PPQ and AL at two sites in 2016 and 2017, respectively, using the standard WHO protocol. The patterns of molecular markers associated with artemisinin and PPQ resistance were investigated for the first time in Somalia. RESULTS: A total of 339 patients were enrolled with 139 for AL and 200 for DHA/PPQ. With AL, no parasite recurrence was observed among patients treated at either site, corresponding to 100% clinical and parasitological responses. For DHA-PPQ, an adequate clinical and parasitological response rate > 97% was observed. All study patients on both treatments at both sites were parasite-free on day 3. Of the 138 samples with interpretable results for the polymorphism in Pfk13, only one (0.7%), from Bosaso, contained a non-synonymous mutation (R622I), which is not one of the known markers of artemisinin resistance. No Pfpm2 amplification was observed among the 135 samples with interpretable results. CONCLUSIONS: AL and DHA/PPQ were highly effective in the treatment of uncomplicated falciparum malaria, and there was no evidence of resistance to artemisinin or PPQ. These two combinations are thus relevant in the chemotherapeutic strategy for malaria control in Somalia. Trial registration ACTRN12616001005448 (Jowhar DP study), ACTRN12616000553471 (Bosaso DP study), ACTRN12617001055392 (AL study in Bosaso and Jowhar).

Incremental learning for ν-Support Vector Regression.

The ν-Support Vector Regression (ν-SVR) is an effective regression learning algorithm, which has the advantage of using a parameter ν on controlling the number of support vectors and adjusting the width of the tube automatically. However, compared to ν-Support Vector Classification (ν-SVC) (Schölkopf et al., 2000), ν-SVR introduces an additional linear term into its objective function. Thus, directly applying the accurate on-line ν-SVC algorithm (AONSVM) to ν-SVR will not generate an effective initial solution. It is the main challenge to design an incremental ν-SVR learning algorithm. To overcome this challenge, we propose a special procedure called initial adjustments in this paper. This procedure adjusts the weights of ν-SVC based on the Karush-Kuhn-Tucker (KKT) conditions to prepare an initial solution for the incremental learning. Combining the initial adjustments with the two steps of AONSVM produces an exact and effective incremental ν-SVR learning algorithm (INSVR). Theoretical analysis has proven the existence of the three key inverse matrices, which are the cornerstones of the three steps of INSVR (including the initial adjustments), respectively. The experiments on benchmark datasets demonstrate that INSVR can avoid the infeasible updating paths as far as possible, and successfully converges to the optimal solution. The results also show that INSVR is faster than batch ν-SVR algorithms with both cold and warm starts.

Multi-Modality Vertebra Recognition in Arbitrary Views Using 3D Deformable Hierarchical Model.

Computer-aided diagnosis of spine problems relies on the automatic identification of spine structures in images. The task of automatic vertebra recognition is to identify the global spine and local vertebra structural information such as spine shape, vertebra location and pose. Vertebra recognition is challenging due to the large appearance variations in different image modalities/views and the high geometric distortions in spine shape. Existing vertebra recognitions are usually simplified as vertebrae detections, which mainly focuses on the identification of vertebra locations and labels but cannot support further spine quantitative assessment. In this paper, we propose a vertebra recognition method using 3D deformable hierarchical model (DHM) to achieve cross-modality local vertebra location+pose identification with accurate vertebra labeling, and global 3D spine shape recovery. We recast vertebra recognition as deformable model matching, fitting the input spine images with the 3D DHM via deformations. The 3D model-matching mechanism provides a more comprehensive vertebra location+pose+label simultaneous identification than traditional vertebra location+label detection, and also provides an articulated 3D mesh model for the input spine section. Moreover, DHM can conduct versatile recognition on volume and multi-slice data, even on single slice. Experiments show our method can successfully extract vertebra locations, labels, and poses from multi-slice T1/T2 MR and volume CT, and can reconstruct 3D spine model on different image views such as lumbar, cervical, even whole spine. The resulting vertebra information and the recovered shape can be used for quantitative diagnosis of spine problems and can be easily digitalized and integrated in modern medical PACS systems.

Regression Segmentation for M³ Spinal Images.

Clinical routine often requires to analyze spinal images of multiple anatomic structures in multiple anatomic planes from multiple imaging modalities (M(3)). Unfortunately, existing methods for segmenting spinal images are still limited to one specific structure, in one specific plane or from one specific modality (S(3)). In this paper, we propose a novel approach, Regression Segmentation, that is for the first time able to segment M(3) spinal images in one single unified framework. This approach formulates the segmentation task innovatively as a boundary regression problem: modeling a highly nonlinear mapping function from substantially diverse M(3) images directly to desired object boundaries. Leveraging the advancement of sparse kernel machines, regression segmentation is fulfilled by a multi-dimensional support vector regressor (MSVR) which operates in an implicit, high dimensional feature space where M(3) diversity and specificity can be systematically categorized, extracted, and handled. The proposed regression segmentation approach was thoroughly tested on images from 113 clinical subjects including both disc and vertebral structures, in both sagittal and axial planes, and from both MRI and CT modalities. The overall result reaches a high dice similarity index (DSI) 0.912 and a low boundary distance (BD) 0.928 mm. With our unified and expendable framework, an efficient clinical tool for M(3) spinal image segmentation can be easily achieved, and will substantially benefit the diagnosis and treatment of spinal diseases.

Endoscopic trans-iliac approach to L5-S1 disc and foramen - a report on clinical experience.

BACKGROUND: The lumbosacral junction is a difficult area for spine surgery because of the complex anatomy. In the era of minimally invasive spine surgery, the presence of the iliac wing has, at the level of lumbosacral junction, created a major obstacle in the paths of two of the major approaches, namely, the direct lateral and percutaneous posterolateral endoscopic approaches. A trans-iliac cadaver study published by the senior author and co-workers in 1997, suggested the possibility of an alternative approach to the lumbosacral junction. PURPOSE: To determine the feasibility of percutaneous, endoscopic trans-iliac approach to the L5-S1 disc and foramen. STUDY DESIGN: Prospective case series study. MATERIALS AND METHODS: 15 consecutive patients undergoing the transiliac approach to L5-S1 disc and foramen were included in the study. Pre- and postoperative visual analogue scale (VAS); Oswestry Disability Index (ODI); and intra-operative blood loss and operative time, were obtained for the study. Preoperative MRI or CT scan was used to determine the need for trans-iliac access. The procedure was performed with the patient in prone position and under monitored sedation for decompression. Endotracheal anesthesia was used for fusion cases. The transiliac access was established with a cannulated drill or core drill through the iliac wing. Once the trans-iliac window had been created, the rest of the procedure proceeded as for percutaneous endoscopic transforaminal decompression and fusion. RESULTS: 15 patients (9 male and 6 female) participated in the study. The VAS for back and leg pain significantly improved in all patients. The ODI dropped by more than 50%. There was minimal blood loss, and transient post-operative dysesthesia in 2 cases which resolved after 3 weeks. CONCLUSION: Endoscopic trans-iliac approach to the L5-S1 disc and foramen is feasible and safe. Decompression can be performed safely via trans-iliac access with minimal blood loss, and in a short operative time.

A quantitative definition of scaphoid union: determining the inter-rater reliability of two techniques.

BACKGROUND: Despite extensive literature supporting the use of computerized tomography (CT) scans in evaluating scaphoid fractures, there has not been a consensus on the methodology for defining and quantifying union. The purpose of this study was to test the inter-observer reliability of two methods of quantifying scaphoid union. METHODS: The CT scans of 50 non-operatively treated scaphoid fractures were reviewed by four blinded observers. Each was asked to classify union into one of three categories, united, partially united, or tenuously united, based on their general impression. Each reviewer then carefully analyzed each CT slice and quantified union based on two methods, the mean percentage union and the weighted mean percentage union. The estimated percentage of scaphoid union for each scan was recorded, and inter-observer reliability for both methods was assessed using a Bland-Altman plot to calculate the 95% limits of agreement. Kappa statistic was used to measure the degree of agreement for the categorical assessment of union. RESULTS: There was very little difference in the percentage of union calculated between the two methods (mean difference between the two methods was 1.2 ± 4.1%), with each reviewer demonstrating excellent agreement between the two methods based on the Bland-Altman plot. The kappa score indicated very good agreement (Κ = 0.80) between the consultant hand surgeon and the musculoskeletal radiologist, and good agreement (Κ = 0.62) between the consultant hand surgeon and the hand fellow for the categorical assessment of union. CONCLUSIONS: This study describes two methods of quantifying and defining scaphoid union, both with a high inter-rater reliability. This indicates that either method can be reliably used, making it an important tool for both for clinical use and research purposes in future studies of scaphoid fractures, particularly those which are using union or time to union as their endpoint. LEVEL OF EVIDENCE: Diagnostic, level III.

Arthroscopic discectomy and interbody fusion of the thoracic spine: A report of ipsilateral 2-portal approach.

BACKGROUND: The standard approach to the thoracic disc is through thoracotomy. The video-assisted thoracoscopic approach has been used as an alternative to the open approach for nearly 20 years, and more recently, extracavitary, posterolateral approaches have been introduced. Both the transthoracic procedures involve deflating the lung for access to the spine, and postoperative thoracic drainage is necessary; postoperative morbidity can be significant. The retropleural procedures are in their infancy, but the published results are promising. The purpose of this study is to introduce the posterolateral arthroscopic thoracic decompression and fusion procedure, which is extrapleural, less disruptive to normal anatomy, and cost-effective. METHODS: Fifteen consecutive patients who underwent arthroscopic decompression and interbody fusion of the thoracic spine were prospectively studied according to the hospital's institutional review board protocol. The Short Form 36 and visual analog scale questionnaires were completed preoperatively and postoperatively. Paired t tests were used for statistical analysis. The patient was placed in the prone position on a radiolucent table, and instrumentation was performed under fluoroscopic control. Two portals were developed ipsilaterally (one for the arthroscope and the other for instruments) on the side of disc herniation, and a single portal was used on the contralateral side. Various instruments were used for disc excision and exploration of the spinal canal. Fusion was accomplished with bilateral corticocancellous dowels obtained from the iliac crests. Infiltration of the access channel and facet injections of the contiguous joints were performed with bupivacaine, for immediate postoperative pain control. RESULTS: Fifteen patients with a mean age of 54 years were followed up for 28 months postoperatively. The overall back pain score decreased from 7.2 (SD, 1.5) to 3 (SD, 2) after the procedure (P < .005). Eleven patients were satisfied with their current lifestyle postoperatively as opposed to one preoperatively. Two patients had reoccurrences. Hospital stay averaged 18.5 hours. The operating room cost and the cost of hospital stay was 51.9% of the cost of anterior open discectomy. CONCLUSIONS: The extrapleural, biportal, ipsilateral arthroscopic approach for the decompression and interbody fusion of the thoracic spine is feasible, cost-effective, less traumatic, and associated with minimal complications. The best results were obtained in patients with single-level thoracic disc herniation. The technique is applicable for most thoracic disc herniations.

Endoscopic transforaminal decompression, interbody fusion, and percutaneous pedicle screw implantation of the lumbar spine: A case series report.

BACKGROUND: On the basis of the experiences gained from conventional open spinal procedures, a long list of desirable objectives have emerged with the evolution of the lesser invasive spinal procedures. At the top of that list is the desire to minimize the trauma of surgery. The rest of the objectives, which include reductions of operating time, surgical blood loss, hospital stay, postoperative narcotic medication, convalescence, complication rates, and escalating health care costs, as well as the desire of elderly patients to continue rigorous physical activities, largely depend on the ability to minimize the trauma of surgery. The purpose of this study was to investigate the feasibility of the least invasive lumbar decompression, interbody fusion and percutaneous pedicle screw implantation, to minimize surgical trauma without compromising the quality of the treatment outcome, as well as to minimize risk of complications. METHODS: In this case series, 60 patients with diagnoses of degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis, in whom nonoperative treatments failed, were treated with endoscopic transforaminal decompression and interbody fusion by 1 surgeon in 2 centers. The outcome measures were as follows: operating time, intraoperative blood loss, hospital stay, Visual Analogue Scale (VAS) scores for back and leg pain, scores on the Roland-Morris Disability Questionnaire, and postoperative imaging studies. A consecutive series of patients who met the treatment criteria completed VAS forms and Roland-Morris questionnaires preoperatively. Surgical procedures included arthroscopic decompression of the foramina and the discs; endplate preparation and implantation of allograft bone chips and bone morphogenetic protein 2 on absorbable collagen sponge into the disc space; and percutaneous implantation of pedicle screws. Postoperatively, the patients again completed the VAS forms and Roland-Morris questionnaires. Their charts were reviewed for office notes, operative notes, hospital stay, medications, and imaging studies. The latest X-ray and computed tomography scan films were reviewed and analyzed. Patients were followed up for a minimum of 6 months. The literature was reviewed for comparison of outcomes. RESULTS: Sixty patients met the inclusion criteria. The mean age was 52.8 years. The duration of illness averaged 5 years. Follow-up ranged from 6 to 25 months, with a mean of 12 months. Preoperative diagnoses included degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis. The mean time in the operating room was 2 hours 54 minutes. Estimated blood loss averaged 57.6 mL. The duration of the hospital stay averaged 2.6 days. Preoperative back pain and leg pain were significantly reduced (P < .005). Forty-seven imaging studies obtained at the last visit, including X-ray and computed tomography scans, showed solid fusion in 28 patients (59.6%), stable fixation in 17 (36.2%), and osteolysis around the pedicle screws in 2 (4.2%). All patients had improvement of motor function, whereas 2 patients complained of residual numbness. In addition, 8 patients (13%) complained of residual discomfort on extension of the lumbar spine. Two patients had pedicle screw-related complications requiring surgery. A review of the literature showed that endoscopic transforaminal decompression and interbody fusion performed better than open transforaminal lumbar interbody fusion/posterior lumbar interbody fusion, minimally invasive transforaminal lumbar interbody fusion, and extreme lateral lumbar interbody fusion, with regard to most parameters studied. CONCLUSIONS: The endoscopic transforaminal lumbar decompression, interbody fusion, and percutaneous pedicle screw instrumentation consistently produced satisfactory results in all demographics. It performed better than the alternative procedures for most parameters studied.

Prevalence of triangular fibrocartilage complex abnormalities on MRI scans of asymptomatic wrists.

PURPOSE: Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ulnar-sided wrist pain; however, its efficacy in this setting still needs clarification. The purposes of this study were to investigate the prevalence of abnormal MRI findings in the triangular fibrocartilage complex (TFCC) in asymptomatic volunteers and to provide the clinician with comparative data when interpreting MRI results. METHODS: A total of 103 asymptomatic volunteers underwent imaging of the wrist using a 1.9-T MR scanner and a send-receive birdcage quadrature coil. The images were evaluated by 3 independent interpreters, 2 musculoskeletal radiologists, and 1 orthopedic hand surgeon. We noted details regarding the TFCC morphology and the presence, characteristics, and location of any TFCC abnormality. RESULTS: The TFCC was considered abnormal in 39 wrists. The scans were abnormal in 31 subjects younger than 50 years of age, in 5 subjects 50 to 59 years of age, and in all subjects older than 60 years of age (3 subjects). We diagnosed a complete tear of the TFCC in 23 wrists. An increase in age was correlated with an abnormal TFCC (r(pb) = 0.23; P = .016). CONCLUSIONS: The prevalence of incidental TFCC findings in MRI scans of asymptomatic subjects is high. The presence of an abnormal TFCC on MRI may be of questionable clinical meaning, because there is a high incidence of TFCC abnormalities in asymptomatic subjects, particularly those over the age of 50. Imaging results must be viewed in the context of the clinical history and physical examination. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.