How does long thoracolumbar realignment surgery of adult spinal kyphotic deformity affect lower extremity compensation? Using full body radiograph.

PURPOSE: By using full body radiograph, the aim of the current study was to elucidate the expected degree of lower extremity compensatory change after long thoracolumbar realignment surgery with adult spinal deformity patient who had normal or only mild osteoarthritis on lower extremities. METHODS: Two novel parameters were used for assessment of regional compensation of the lower extremity. The Pearson correlation test was used to assess the correlation of postoperative changes of lower extremity compensation with the other spinopelvic parameters. RESULTS: Overall, 113 spinal deformity patients (mean age was 54.5 years) were recruited and the average number of fused vertebrae was 13.3 ± 3.5. Except pelvic tilt (PT), postoperative sacrum-femur angle (SF) changes showed only moderate correlation with all angular spinopelvic parameters (r = 0.323-0.374; p < .001 to p = .001). Also C7 sagittal vertical axis showed no significant correlation with SF (p = .584-.621). However, postoperative changes of sagittal femur-tibia angle (SFT) reported strong correlation with all parameters evaluated (r = 0.455-0.586; p < .001 to p = .046). CONCLUSION: For adult spinal deformity patients who had normal or only mild osteoarthritis on the lower extremities underwent long thoracolumbar realignment surgery, the surgeon could expect improvement of compensatory change of the knee with correction of spinopelvic parameters. However, the degree of hip compensation improvement was relatively difficult to predict than that of the knee, except PT.

Novel radiographic parameters for the assessment of total body sagittal alignment in adult spinal deformity patients.

OBJECTIVE: In this study, the authors' goal was to develop and validate novel radiographic parameters that better describe total body sagittal alignment (TBSA). METHODS: One hundred sixty-six consecutive operative spinal deformity patients were evaluated using full-body stereoradiographic imaging. Seven TBSA parameters were measured and then correlated to 6 commonly used spinopelvic measurements. TBSA measures consisted of 4 distance measures relating the cranial center of mass (CCOM) to the sacrum, hips, knees, and ankles, and 3 angular measures relating the CCOM to the hips, knees, and ankles. Furthermore, each TBSA parameter was correlated to patient-reported outcome (PRO) scores using the Oswestry Disability Index (ODI) and Scoliosis Research Society-22 (SRS-22) instruments. Thirty patients were randomly selected for inter- and intraobserver reliability testing of the TBSA parameters using intraclass correlation coefficients (ICCs). RESULTS: All TBSA radiographic parameters demonstrated strong linear correlation with the currently accepted primary measure of sagittal balance, the C7 sagittal vertical axis (r = 0.55-0.96, p < 0.001). Moreover, 5 of 7 TBSA measures correlated strongly with ODI and SRS-22 total scores (r = 0.42-0.51, p < 0.001). Inter- and intraobserver reliability for all TBSA measures was good to excellent (interrater ICC = 0.70-0.98, intrarater ICC = 0.77-1.0). CONCLUSIONS: In spine deformity patients, novel TBSA radiographic parameters correlated well with PROs and with currently utilized spinal sagittal measurements. Inter- and intrarater reliability was high for these novel parameters. This is the first study to propose a reliable method for measuring head-to-toe global spinal alignment.

Relationship between facet joint tropism and degeneration of facet joints and intervertebral discs based on a histological study.

PURPOSE: Evaluate the correlation between lumbar facet joint tropism, lumbar facet joint degeneration, and intervertebral disc degeneration. METHODS: Forty-two of facet joints were evaluated histologically and radiologically. RESULTS: The correlation between facet joint tropism and histologic, CT, and MRI grading was -0.159 (P = 0.339), 0.025 (P = 0.226) and -0.270 (P = 0.102), respectively. The correlation between facet joint tropism and intervertebral disc MRI grading was 0.346 (P = 0.033), and that between facet joint and intervertebral disc MRI grading was 0.208 (P = 0.210). CONCLUSIONS: Facet joint tropism was correlated with intervertebral disc degeneration but not with facet joint degeneration.

Errata to "Coronal Alignment of the Lower Limb and the Incidence of Constitutional Varus Knee in Korean Females".

[This corrects the article on p. 49 in vol. 27, PMID: 25750894.].

Coronal alignment of the lower limb and the incidence of constitutional varus knee in korean females.

PURPOSE: In total knee arthroplasty (TKA), it is important to restore neutral mechanical alignment. The purpose of this study was to assess whether the lower limb alignment is neutral in healthy Korean females and investigate the incidence of constitutional varus knees among them. MATERIALS AND METHODS: Weight-bearing full-leg standing radiographs were obtained from 118 healthy females between the ages of 20 to 39 years. One radiologist and two orthopaedic surgeons measured the hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), and femoral anatomic mechanical angle (FAMA) on the radiographs and compared with the traditional gold standard HKAA of 0°, MPTA of 3° varus, and FAMA of 6°. RESULTS: The interobserver reliability of the three independent observers was high (p<0.001). The HKAA of the study subjects (1.35°±2.04°) was significantly different from the standard HKAA of 0° (p<0.001), but no statistically significant difference was observed in the MPTA (-3.18°±1.61°) and FAMA (5.99°±0.70°) from the standard values (p=0.083 and p=0.887, respectively). The incidence of constitutional varus alignment was 20.34%. CONCLUSIONS: In Korean females, the mechanical axis of the lower limb was not neutral and the incidence of constitutional varus alignment was slightly higher than that in Western females. We believe that these findings should be taken into consideration in planning reconstructive surgery of the knee, such as TKA, unicompartmental knee arthroplasty, and high tibial osteotomy.