Risk of New Fractures in Vertebroplasty for Multiple Myeloma. A Retrospective Study

Clinical efficacy and biomechanical analysis of a novel hollow pedicle screw combined with kyphoplasty for the treatment of Kümmell disease

Background

Vertebral augmentation is the preferred treatment for Kümmell disease (KD), but there exists a risk of cement displacement resulting in severe back pain and exacerbation of kyphosis. The study aimed to investigate the efficacy and safety of a novel hollow pedicle screw combined with kyphoplasty (HPS-KP) for treating KD, effectively preventing postoperative bone cement displacement.

Methods

The prospective study included 50 KD patients with no neurological deficit detected during clinical and radiological evaluation who underwent HPS-KP (n = 25) and PKP (n = 25) surgeries. The visual analogue scale (VAS) score, Oswestry dysfunction index (ODI), anterior vertebral height (AVH), wedge-shape affected vertebral Cobb angle (WCA), bisegmental Cobb angle (BCA), and complications were evaluated and compared in both groups. Besides, a finite element (FE) model of T11-L2 was constructed. The stress distributions, maximum von Mises stresses of vertebrae and bone cement, and maximum displacement of bone cement were compared and analyzed.

Results

The VAS and ODI scores at 3 days, 3 and 6 months, and 1 year after surgery significantly improved in both groups (p < 0.05). The AVH, BCA, and WCA significantly improved initially after the surgery in both groups (p < 0.05). The displacement of M2 was larger than other models, especially in flexion, right bending, and left and right rotation, while that of M6 was the lowest under all conditions.

Conclusion

HPS-KP was a safe and effective treatment for KD, effectively relieving pain, restoring vertebral height, and correcting local kyphosis, and it had better biomechanical stability and safety than ordinary single PKP and PKP combined with pediculoplasty in avoiding cement loosening and displacement.

Percutaneous vertebroplasty/kyphoplasty contributes to the improved outcome in patients with newly diagnosed multiple myeloma: A single center cohort study

Objective

To evaluate the efficacy and prognosis of percutaneous vertebroplasty/kyphoplasty (PVP/PKP) in patients with newly diagnosed multiple myeloma (NDMM).

Methods

Clinical data of NDMM patients who underwent PVP/PKP during front-line regimen at Peking Union Medical College Hospital from January 1, 2003, to June 30, 2023, were analyzed. Patients with comparable bone diseases not receiving orthopedic surgery were selected as controls. Visual analogue scale (VAS) score, progression-free survival (PFS), and overall survival (OS) were compared.

Results

Baseline characteristics were matched between the surgical group (n = 51 with 56 surgeries) and non-surgical group (n = 102), including demographics, tumor load, International Staging System (ISS), bone diseases, cytogenetic abnormalities, first-line treatment, and autologous stem-cell transplantation (ASCT). Bone lesions for PVP/PKP were located at thoracic vertebrae (53.6 %, 30/56) or lumbosacral vertebrae (46.4 %, 26/56). The postoperative VAS score was significantly improved (2.25 ± 0.81 vs 5.92 ± 1.05, P < 0.001). The median follow-up time was 51[38-70] months. Kaplan-Meier survival analysis suggested that both PFS (37[17-89] vs 23[12-61] months, HR 0.648, 95 %CI 0.431-0.973, P = 0.047) and OS (not reached vs 66[28-NR] months, HR 0.519, 95 %CI 0.296-0.910, P = 0.045) were significantly prolonged in the surgical group. COX multivariate analysis suggested that PVP/PKP was an independent prognostic factor for PFS (P = 0.021, HR 0.589, 95 %CI 0.376-0.922) and OS (P = 0.038, HR 0.496, 95 %CI 0.255-0.963). Subgroup analysis confirmed that patients with ISS II/III or non-ASCT achieved better PFS and OS in the surgical group (PFS: P = 0.033, P = 0.040; OS: P = 0.024, P = 0.018 respectively), while similar survival outcome was observed in patients with ISS I or ASCT between two groups.

Conclusion

For NDMM patients, not only does PVP/PKP alleviate bone pain, meanwhile, it improves the PFS and OS in advanced subpopulation or non-transplant myeloma patients, which suggests that shortening the gap from symptom onset to diagnosis by orthopedic surgery favors clinical prognosis.

Modified poly(methyl methacrylate) bone cement in the treatment of Kümmell disease

Kümmell disease (KD) causes serious vertebral body collapse in patients. However, only a few case reports have been conducted and the number of patients with KD investigated was limited. Additionally, the frequently used poly(methyl methacrylate) (PMMA) bone cement for KD is limited by excessive modulus and poor biocompatibility. Herein, we aimed to modify PMMA bone cement with mineralized collagen (MC), and compare the clinical effects, image performance and finite element analysis between the modified bone cement and PMMA bone cement for the treatment of phase I and II KD. Thirty-nine KD patients treated with PMMA bone cement and 40 KD patients treated with MC-modified PMMA bone cement from June 2015 to March 2017 were retrospectively analyzed. The surgical procedure, intraoperative blood loss, hospital stay and complications were compared between different groups. Visual analog scale, Oswestry disability index, anterior vertebral height, posterior vertebral height, computed tomography value, adjacent vertebral re-fracture, Cobb angle and wedge-shaped correction angle were evaluated. Additionally, the representative sample was selected for finite element analysis. We found that the MC-modified PMMA bone cement could achieve the same effect as that of PMMA bone cement and was associated with better vertebral height restoration in the long term.