OPLL: Ossification Of The Posterior Longitudinal Ligament

Preface ix

01 Introduction 1
Historical Background 1
Japanese Era in OPLL Research 2
OPLL as a Subset of Enthesopathy 4
OPLL beyond the Japanese Disease 5

02 Epidemiology of Ossification of the
Posterior Longitudinal Ligament in Korea 9
Introduction 9
Epidemiologic Studies of OPLL in Korean 10
OPLL in Korean Patients with AS 14
Prevalence and Association Factors of OPLL in Patients with SpA 16

03 Epidemiology of Ossification of the
Posterior Longitudinal Ligament in Japan 19
Introduction 19
Incidence & Clinical Features 20
Imaging 21

04 Epidemiology of Ossification of the Posterior Longitudinal
Ligament in the Chinese Population 23
Introduction 23
Discussion 27

05 The Genetics and Molecular Research in Ossification
of the Posterior Longitudinal Ligament 31
Introduction 31
Familial Surveys and Genetic Pattern Studies 32
NPPS 33
COL11A2 and COL6A1 34
BMP-2 and TGF-b 35
Exogenous Factors May Contribute to OPLL 36
Miscellaneous 37

06 Pathogenesis and Pathophysiology of Ossification
of the Posterior Longitudinal Ligament 41
Introduction 41
Pathology of Ossified PLL 42
Contributing Factors in the Pathogenesis of OPLL 44

07 Natural History of Ossification of the Posterior
Longitudinal Ligament of Cervical Spine 53
Introduction 53
Natural History 54
Natural History of Cervical OPLL at Seoul National University Hospital (SNUH) 62

08 Clinical Manifestations and Differential Diagnosis of
Cervical Ossification of the Posterior Longitudinal Ligament 71
Introduction 71
Clinical Manifestation 72
Differential Diagnosis 73

09 Radiologic Diagnosis and Novel MR Imaging Technologies for
Ossification of the Posterior Longitudinal Ligament 77
Plain Radiograph 77
Computed Tomography 80
Magnetic Resonance Imaging 82

10 Conservative Management of Ossification of the
Posterior Longitudinal Ligament in the Cervical Spine 89
Introduction 89
Natural Course of OPLL 90
Dynamic Factors in Myelopathy Due to OPLL 90
Extent of Compression of the Spinal Cord and Prognosis 91
Indication of Conservative Treatment 91
Conservative Treatment Methods 92

11 Surgical Indication and Strategy for the Cervical Ossification
of the Posterior Longitudinal Ligament: Evolution and Outcome 97
Introduction 97
Indication 98
Anterior Surgery with Strut Fixation 98
Posterior Approach ? Myoarchitectonic Spino-Laminoplasty (MSLP) Technique 102
Myoarchitectonic Spino-Laminoplasty (MSLP) ? Biomechanical Efficacy 102
Myoarchitectonic Spino-Laminoplasty (MSLP) ?
Postoperative and Preoperative Neck Pain 105
Selection Criteria for Approaches ? Principles and Strategy 106
Combined Approach 108
Salience in the Axial and Sagittal Planes:
Configuration of OPLL Likely to Result in Postoperative Deteriorations 108
Complications Statistics ? Posterior Surgery 113

12 Anterior Surgical Approach for Ossification of the
Posterior Longitudinal ligament in the Cervical Spine 117
Introduction 117
Surgical Indication of Anterior Surgical Approach 118
Radiographic Criteria for Selection of Surgical Approach 118
Perioperative Preparations 119
Surgical Techniques 120
Complications 125

13 Posterior Surgical Approach for Ossification of the
Posterior Longitudinal Ligament in the Cervical Spine 129
Introduction 129
Indication for Surgical Treatment 130
Choice of Surgical Procedures 130
Posterior Decompression Procedures 131
Simultaneous Posterior Decompression and Fixation 132

14 An Alternative Surgical Approach for Cervical Ossification
of the Posterior Longitudinal Ligament:
Multilevel Oblique Corpectomy Without Fusion 137
Introduction 137
Indications & Planning 138
Expected Complications 141
Discussion and Practical Points 142

15 Complications and Avoidance in the Surgical Treatments
for Ossification of the Posterior Longitudinal Ligament
in the Cervical Spine 149
Introduction 149
Complications During the Anterior Approach to OPLL Lesions 151
Complications of the Posterior Approach to OPLL Lesions 160

16 Surgical Outcome and Prognostic Factors for Ossification of the
Posterior Longitudinal Ligament in the Cervical Spine 177
Introduction 177
Surgical Outcome 178
Prognostic Factors 181

17 Ossification of the Posterior Longitudinal Ligament
in the Thoracic Spine and its Surgical Management 189
Introduction 189
Etiology, Pathomechanism, and Classification of T-OPLL 190
Surgical Methods 190
Surgical Outcomes 195
Factors Related to Outcomes 196
Complications 197

18 Relationship Between Diffuse Idiopathic
Skeletal Hyperostosis and OPLL 201
Introduction 201
Diffuse Idiopathic Skeletal Hyperostosis 202
Associations of DISH and OPLL 204

19 Relationship Between Ossification of the Posterior
Longitudinal Ligament and Ossification of the Ligamentum Flavum 209
Introduction 209
Paravertebral Ligamentous Ossification: OPLL, OLF and DISH 210

Index 217