RESUMEN
Background: Corrective osteotomy is an effective surgery for correcting posture in patients with ankylosing spondylitis (AS). Despite satisfactory correction, some patients experience re-stooping during follow-up. However, there have been no studies on re-stooping in AS. We aimed to analyze the factors that affect re-stooping. Methods: Fifty patients (50 cases) who underwent thoracolumbar corrective osteotomy for AS from March 2006 to April 2018 were analyzed. We defined re-stooping as global kyphosis that recurs after corrective osteotomy. The patients were divided into two groups based on the ratio of correction loss: non-re-stooping group (N group) and re-stooping group (R group). We analyzed the demographic data and radiological parameters, such as modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), sagittal vertical axis, and various angles. We also investigated the factors affecting re-stooping by analyzing the correlation between the ratio of correction loss and various factors. Results: A significant difference was seen in the change in the mSASSS from before surgery to the last follow-up between the N group (2.87 ± 3.08) and the R group (9.20 ± 5.44). In multivariate analysis, only the change in the mSASSS from before surgery to the last follow-up was significantly correlated with the ratio of correction loss. Conclusions: Thoracolumbar corrective osteotomy seems to provide high satisfaction among patients with AS but can lead to re-stooping during follow-up. The change in mSASSS was related with re-stooping in the current study. We recommend active rehabilitative exercises and appropriate medication depending on the patient's condition, which may help delay the postoperative progression of AS.
Asunto(s)
Cifosis , Espondilitis Anquilosante , Humanos , Espondilitis Anquilosante/diagnóstico por imagen , Espondilitis Anquilosante/cirugía , Resultado del Tratamiento , Columna Vertebral/cirugía , Cifosis/diagnóstico por imagen , Cifosis/cirugía , Osteotomía , Fenolftaleína , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/cirugía , Estudios RetrospectivosRESUMEN
STUDY DESIGN: A retrospective comparative cohort study. OBJECTIVE: To investigate the causes of jack-knife posture (JKP) without proximal junctional kyphosis (PJK) and to compare the causes of PJK and JKP without PJK. SUMMARY OF BACKGROUND DATA: PJK causing stooping posture could be inevitable after long instrumented lumbar fusion for degenerative sagittal imbalance. However, few studies have addressed JKP without PJK, which is a different type of sagittal malalignment. METHODS: Ninety-four adult patients who underwent long instrumented lumbar fusion for degenerative sagittal imbalance were divided into three groups depending on the presence of a postoperative sagittal deformity: JKP, PJK, or none. JKP was defined as a sagittal vertical axis of at least 8 cm anterior to the posterosuperior corner of S1 upper endplate without PJK. PJK was defined as a proximal kyphotic angle ≥10° and at least 10° greater than the preoperative measurement. RESULTS: Seventeen patients (18.1%) showed JKP, and 39 patients (41.5%) showed PJK. The mean age at the surgery of JKP and PJK patients was 70.0 and 65.5 years, respectively (p = .05). JKP developed more frequently if the preoperative pelvic tilt was <25° or the sagittal vertical axis was >8 cm (p = .048, 0.004, respectively). PJK developed more frequently if the preoperative pelvic tilt was >25°, surgically corrected lumbar lordosis was >30°, or the lumbar lordosis to thoracic kyphosis angle was <0° (p = .002, .010, .031, respectively). JKP was more likely to develop in patients without sacropelvic fixation (p = .042), although they had a more degenerative L5-S1 segment (p = .010). CONCLUSIONS: Postoperative sagittal deformity can be classified into two types: JKP and PJK. JKP is caused mainly by hip and back extensor muscle weakness even though the cause of postoperative sagittal decompensation could be multifactorial. However, PJK developed mainly due to spinopelvic malalignment. Therefore, hip and back extensor weakness, which is age-dependent, may explain why older patients experienced more postoperative sagittal deformity. LEVEL OF EVIDENCE: Level IV.
Asunto(s)
Vértebras Lumbares/cirugía , Complicaciones Posoperatorias/etiología , Postura , Fusión Vertebral , Anciano , Femenino , Humanos , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Huesos Pélvicos/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Estudios RetrospectivosRESUMEN
While epidemiologic data suggests that one in four older adults have difficulty performing stooping and crouching (SC) tasks, little is known about how aging affects SC performance. This study investigated differences between young and older adults in lower limb kinematics and underfoot center of pressure (COP) measures when performing a series of SC tasks. Twelve healthy younger and twelve healthy older participants performed object-retrieval tasks varying in: (1) initial lift height, (2) precision demand, and (3) duration. Whole-body center of mass (COM), underfoot COP, and hip and knee angular kinematics (maximum angles and velocities) were analyzed. Compared to younger, older participants moved slower when transitioning into and out of pick-up postures that were characterized by less hip and knee flexion. Older participants also showed a diminished ability to adapt to the changing postural demands of each set of tasks. This was especially evident during longer tasks, whereby older individuals avoided high knee flexion crouching postures that were commonly used by younger participants. Older adults also tended to exhibit faster and more frequent COP trajectory adjustments in the anterior-posterior direction. It is likely that limitations in physical characteristics such as lower limb strength and range of motion contributed to these differences.