Postoperative decrease in Hounsfield unit values at adjacent vertebrae after thoraco-pelvic fusion as a risk factor of proximal junctional kyphosis.

Proximal junctional kyphosis and failure is a common complication of adult spinal deformity surgery, with osteoporosis as a risk factor. This retrospective study investigated the influence of long thoracolumbar fusion with pelvic fixation on regional bone density of adjacent vertebrae (Hounsfield units on computed tomography) and evaluated the association between bone loss and the incidence of proximal junctional kyphosis and failure. Patients who underwent long thoracolumbar fusion (pelvis to T10 or above) or single-level posterior lumbar interbody fusion (control group) between 2016 and 2022 were recruited. Routine computed tomography preoperatively and within 1-2 weeks postoperatively was performed. Postoperative changes in Hounsfield unit values in the vertebrae at one and two levels above the uppermost instrumented vertebrae (UIV + 1 and UIV + 2) were evaluated. Overall, 127 patients were recruited: 45 long fusion (age, 73.9 ± 5.6 years) and 82 proximal junctional kyphosis and failure (age, 72.5 ± 9.3 years). Postoperative computed tomography was performed at a median [interquartile range] of 3.0 [1.0-7.0] and 4.0 [1.0-7.0] days, respectively. In both groups, Hounsfield unit values at UIV + 2 were significantly decreased postoperatively. In the long-fusion group, Hounsfield unit values at UIV + 1 and UIV + 2 were significantly lower in patients with proximal junctional kyphosis and failure (within 18 months postoperatively) than in those without proximal junctional kyphosis and failure. Proximal junctional kyphosis and failure and long thoraco-pelvic fusion negatively affect regional Hounsfield unit values at adjacent levels immediately after surgery. Patients with subsequent proximal junctional kyphosis and failure show greater postoperative bone loss at adjacent levels than those without.

Successful treatment of atypical femoral fracture with autogenous bone grafting in a patient on denosumab for bone metastasis from breast cancer: A case report.

Atypical femoral fractures (AFFs) occur with minor trauma and are believed to be a potential complication of the prolonged use of antiresorptive agents, such as bisphosphonate and denosumab, for the treatment of bone metastasis. In comparison with typical femoral fractures, AFFs have a higher incidence of complications, including implant failure and delayed union or nonunion. This report describes the case of a 42-year-old woman who developed denosumab-associated AFF after denosumab therapy for bone metastasis from breast cancer. Surgical treatment with IMN was performed after open anatomical reduction. To reduce the risk of delayed union and nonunion, the autogenous bone graft obtained from the iliac crest was conducted. The radiograph taken 5 weeks after surgery showed callus formation. Full weight bearing was allowed 3 months after surgery. Six months postoperatively, radiographs and computed tomography images demonstrated bone union. Twelve months after surgery, the patient was able to walk easily without pain. For cancer patients with bone metastasis whose life expectancy may be limited, a decline in physical activity can be fatal. Consequently, it is crucial to avoid a decrease in activities of daily living brought about by delayed union or nonunion. In this regard, autogenous bone grafting is a viable and effective technique for the treatment of AFFs in patients with bone metastases.

Dynamization-Posterior Lumbar Interbody Fusion for Hemodialysis-Related Spondyloarthropathy: Evaluation of the Radiographic Outcomes and Reoperation Rate within 2 Years Postoperatively.

STUDY DESIGN: Clinical case series. PURPOSE: This study aimed to report dynamization-posterior lumbar interbody fusion (PLIF), our surgical treatment for hemodialysisrelated spondyloarthropathy (HSA), and investigate patients' postoperative course within 2 years. OVERVIEW OF LITERATURE: HSA often requires lumbar fusion surgery. Conventional PLIF for HSA may cause progressive destructive changes in the vertebral endplate, leading to progressive cage subsidence, pedicle screw loosening, and pseudoarthrosis. A dynamic stabilization system might be effective in patients with a poor bone quality. Thus, we performed "dynamization-PLIF" in hemodialysis patients with destructive vertebral endplate changes. METHODS: We retrospectively examined patients with HSA who underwent dynamization-PLIF at our hospital between April 2010 and March 2018. The radiographic measurements included lumbar lordosis and local lordosis in the fused segment. The evaluation points were before surgery, immediately after surgery, 1 year after surgery, and 2 years after surgery. The preoperative and postoperative radiographic findings were compared using a paired t-test. A p-value of less than 0.05 was considered significant. RESULTS: We included 50 patients (28 males, 22 females). Lumbar lordosis and local lordosis were significantly improved through dynamization- PLIF (lumbar lordosis, 28.4°-35.5°; local lordosis, 2.7°-12.8°; p<0.01). The mean local lordosis was maintained throughout the postoperative course at 1- and 2-year follow-up (12.9°-12.8°, p=0.89 and 12.9°-11.8°, p=0.07, respectively). Solid fusion was achieved in 59 (89%) of 66 fused segments. Solid fusion of all fixed segments was achieved in 42 cases (84%). Within 2 years postoperatively, only six cases (12%) were reoperated (two, surgical debridement for surgical site infection; two, reoperation for pedicle screw loosening; one, laminectomy for epidural hematoma; one, additional fusion for adjacent segment disease). CONCLUSIONS: Dynamization-PLIF showed local lordosis improvement, a high solid fusion rate, and a low reoperation rate within 2 years of follow-up.

Association Between Paravertebral Muscle Mass and Improvement in Sagittal Imbalance After Decompression Surgery of Lumbar Spinal Stenosis.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: This study examined associated factors for the improvement in spinal imbalance following decompression surgery without fusion. SUMMARY OF BACKGROUND DATA: Several reports have suggested that decompression surgery without fusion may have a beneficial effect on sagittal balance in patients with lumbar spinal stenosis (LSS) through their postoperative course. However, few reports have examined the association between an improvement in sagittal imbalance and spinal sarcopenia. METHODS: We retrospectively reviewed 92 patients with LSS and a preoperative sagittal vertical axis (SVA) more than or equal to 40 mm who underwent decompression surgery without fusion at a single institution between April 2017 and October 2018. Patients' background and radiograph parameters and the status of spinal sarcopenia, defined using the relative cross-sectional area (rCSA) of the paravertebral muscle (PVM) and psoas muscle at the L4 caudal endplate level, were assessed. We divided the patients into two groups: those with a postoperative SVA less than 40 mm (balanced group) and those with a postoperative SVA more than or equal to 40 mm (imbalanced group). We then compared the variables between the two groups. RESULTS: A total of 29 (31.5%) patients obtained an improved sagittal imbalance after decompression surgery. The rCSA-PVM in the balanced group was significantly higher than that in the imbalanced group (P = 0.042). The preoperative pelvic incidence (PI)-lumbar lordosis (LL) mismatch (P = 0.048) and the proportion with compression vertebral fracture (P = 0.028) in the balanced group were significantly lower than those in the imbalanced group. A multivariate logistic regression analysis identified PI-LL less than or equal to 10° and rCSA-PVM more than or equal to 2.5 as significant associated factor for the improvement in spinal imbalance following decompression surgery. CONCLUSION: A larger volume of paravertebral muscles and a lower PI-LL were associated with an improvement in sagittal balance in patients with LSS who underwent decompression surgery.Level of Evidence: 3.

Surgical treatment for cervical spine injury in nonagenarians: A report of three cases.

Among the elderly, even minor injuries can cause cervical spine fractures. With the increasing number of nonagenarians, the opportunities for treatment of cervical spine injuries in nonagenarians are getting to be more common. Conservative therapy is often chosen in nonagenarians with cervical spine injuries because of high risk associated with surgical treatment; however, we present herein the cases of three patients in nonagenarians who underwent surgical treatment for cervical spine injury. After a fall, three cases of nonagenarians who lived alone and independent were diagnosed with a Jefferson fracture and minor dislocated type II odontoid fracture, a C4 fracture with diffuse idiopathic skeletal hyperostosis, and a fracture-dislocation of C2, respectively. Their past medical history included several diseases, but we decided that spine surgery under general anesthesia was acceptable based on their pre-injury condition. We performed posterior fixation for all cases. As a result, while two patients developed postoperative minor complications, all cases showed favorable postoperative courses. They acquired independent or partially assisted walking and were transferred to the hospital for rehabilitation. If fundamental activity of daily living and general condition permit, posterior fixation seems to be a good choice even in nonagenarians.

Radiological features of cervical spine in dropped head syndrome: a matched case-control study.

PURPOSE: Dropped head syndrome (DHS) is presumably caused by focal myopathy in the cervical posterior muscles; however, distinguishable radiological features of the cervical spine in DHS remain unidentified. This study investigated the radiological features of the cervical spine in dropped head syndrome. METHODS: The records of DHS patients and age- and sex-matched cervical spondylotic myelopathy (CSM) patients were reviewed. Cervical spinal parameters (C2-7, C2-4, and C5-7 angles) were assessed on lateral cervical spine radiographs. Quantitative radiographic evaluation of cervical spine degeneration was performed using the cervical degenerative index (CDI), which consists of four elements: disk space narrowing (DSN), endplate sclerosis, osteophyte formation, and listhesis. RESULTS: Forty-one DHS patients were included. Statistically significant differences were noted between the upper and lower cervical spine in the sagittal angle parameters on the neutral, flexion, and extension radiographs in DHS group, whereas no significant differences were observed in CSM group. CDI comparison showed significantly higher scores of DSN in C3/4, C4/5, C5/6, and C6/7; sclerosis in C5/6 and C6/7; and osteophyte formation in C4/5, C5/6, and C6/7 in DHS group than in CSM group. Comparison of listhesis scores revealed significant differences in the upper levels of the cervical spine (C2/3, C3/4, and C4/5) between two groups. CONCLUSION: Our results demonstrated that the characteristic radiological features in the cervical spine of DHS include lower-level dominant severe degenerative change and upper-level dominant spondylolisthesis. These findings suggest that degenerative changes in the cervical spine may also play a role in the onset and progression of DHS.