Pereira Duarte Matias, Camino Willhuber Gaston O.
Hospital Italiano de Buenos Aires
Injury of the pars interarticularis is among the most common causes of low back pain, especially in adolescent athletes. Sometimes these lesions develop in an asymptomatic manner, and they are detected in adulthood when the injury becomes chronic and symptomatic. The spectrum of pathologies in the pars interarticularis ranges from bone stress and pars fracture (spondylolysis) to isthmic spondylolisthesis, representing an anterior vertebral slippage. Bone stress is considered the earliest sign of disease. Repetitive bone stress causes bone remodeling and may result in spondylolysis, a non-displaced fracture of the pars interarticularis. Also, radiographically visualized spondylolysis is associated with spondylolisthesis in about 25% of cases. Spondylolisthesis, a related condition to spondylolysis, is defined by the forward displacement of the upper vertebra relative to the caudal vertebra. In 1976 Wiltse et al. classified spondylolisthesis into five types: : Type I or dysplastic: is attributed to congenital dysplasia of the superior articular process of the sacrum. Type II or isthmic: is due to a lesion in the pars interarticularis; these subclassify as: (a) Lytic, when a fatigue pars fracture is present. (b) Pars elongation due to multiple healed stress fractures. (c) Acute pars fracture. Type III or degenerative: originates from facet instability without a pars fracture. . Type IV or traumatic: the displacement is due to an acute posterior arch fracture other than pars. . Type V or pathological: is due to posterior vertebral arch bone disease. Type VI or iatrogenic: it is a potential sequel to spinal surgery. For this activity, the focus will be on type II or isthmic spondylolisthesis. Spondylolisthesis was classified by Meyerding et al. into five subtypes according to the magnitude of slippage on plain lateral lumbar radiographs measured by the movement of the upper vertebra relative to the inferior vertebra. Grade I, less than 25% of displacement, . Grade II, between 25 and 50%, . Grade III, between 50 and 75%, . Grade IV, between 75 and 100% and . Grade V or spondyloptosis, when there is no contact between the vertebrae endplates. The commonly used Grade V, representing more than 100% slip or spondyloptosis, is not part of the original grading system. Most pars lesions or spondylolysis occur at L5 (85 to 95%), with L4 being the second most commonly affected vertebra (5 to 15%). The other lumbar levels are less often affected. The defect is unilateral in 22% of the cases.
关节突间部损伤是下腰痛最常见的原因之一，尤其是在青少年运动员中。有时这些损伤以无症状的方式发展，在成年期当损伤变为慢性且有症状时才被发现。关节突间部的病理范围从骨应力和关节突骨折（椎弓根峡部裂）到峡部裂性腰椎滑脱，即椎体向前滑移。骨应力被认为是疾病的最早迹象。反复的骨应力会导致骨重塑，并可能导致椎弓根峡部裂，即关节突间部的无移位骨折。此外，在约25%的病例中，影像学上可见的椎弓根峡部裂与腰椎滑脱有关。腰椎滑脱是与椎弓根峡部裂相关的一种情况，定义为上位椎体相对于下位椎体向前移位。1976年，威尔茨等人将腰椎滑脱分为五种类型：I型或发育异常型：归因于骶骨上关节突的先天性发育异常。II型或峡部裂型：由于关节突间部的病变；这些又可细分为：（a）溶骨性，当存在疲劳性关节突骨折时。（b）由于多次愈合的应力性骨折导致的关节突延长。（c）急性关节突骨折。III型或退变性：起源于小关节不稳且无关节突骨折。IV型或创伤性：移位是由于除关节突外的急性后弓骨折。V型或病理性：由于椎体后弓骨病。VI型或医源性：是脊柱手术的潜在后遗症。对于本活动，重点将放在II型或峡部裂性腰椎滑脱上。迈耶丁等人根据腰椎侧位平片上上位椎体相对于下位椎体的移位程度将腰椎滑脱分为五个亚型。I级，移位小于25%。II级，移位在25%至50%之间。III级，移位在50%至75%之间。IV级，移位在75%至100%之间，以及V级或椎体滑脱，即椎体终板之间无接触。常用的V级表示滑移超过100%或椎体滑脱，它不是原始分级系统的一部分。大多数关节突病变或椎弓根峡部裂发生在L5（85%至95%），L4是第二常见受累椎体（5%至15%）。其他腰椎节段较少受累。22%的病例中缺损为单侧。
