K-Rod: An Innovative Method of Personalized Rib Splinting for Expeditious Management of Flail Chest in Acute Care Settings.

Flail chest is a severe type of multiple rib fracture that can cause ventilation problems and respiratory complications. Historically, flail chest has been mainly managed through pain control and ventilatory support as needed. Operative fixation has recently become popular for the condition, and some studies have revealed its potentially positive effects on the outcomes of patients with flail chest. However, for those for whom surgery is unsuitable, few treatment options, other than simply providing analgesia, are available. Herein, we introduce our innovative method of applying personalized rib splinting for quick management of flail chest, which is easy, tailor-made, and has significant effects on pain reduction.

The effect of posterior lumbar dynamic fixation and intervertebral fusion on paraspinal muscles.

BACKGROUND: The aim of this study was to analyze the effect of unilateral K-rod dynamic internal fixation on paraspinal muscles for lumbar degenerative diseases. METHODS: This study retrospectively collected 52 patients who underwent lumbar surgery with the K-rod group or PLIF. The operation time, intraoperative blood loss, postoperative drainage volume, postoperative exercise time were compared in the two groups. The visual analog scale (VAS) score and the oswestry dysfunction index (ODI) were employed to evaluate the clinical outcomes. The functional cross-sectional area (FCSA) of the paraspinal muscles and paraspinal muscles fat infiltration were measured to assess on the paraspinal muscles. RESULTS: As compared with the PLIF group, the operation time, the postoperative time in the field, and the average postoperative hospital stay in the K-rod internal fixation group were significantly shortened. At the last follow-up, both the groups showed significant improvement in the VAS score and ODI. The FCSA atrophy of the upper and lower adjacent segments (UAS and LAS) of the K-rod internal group was significantly less than that of the PLIF group. The extent of increase in the fatty infiltration of the paraspinal muscles in the K-rod group was significantly lesser than that in the PLIF group. The postoperative low back pain of the two groups of patients was significantly positively correlated with the FCSA atrophy. CONCLUSIONS: As compared to PLIF, the posterior lumbar unilateral K-rod dynamic internal fixation showed significantly lesser paraspinal muscle atrophy and fatty infiltration, which were significantly positively correlated with postoperative low back pain.

Clinical efficacy and radiographic K-rod stabilization for the treatment of multilevel degenerative lumbar spinal stenosis.

BACKGROUND: This study compares the use of radiographic K-Rod dynamic stabilization to the rigid system for the treatment of multisegmental degenerative lumbar spinal stenosis (MDLSS). METHODS: A total of 40 patients with MDLSS who underwent surgical treatment using the K-Rod (n = 25) and rigid systems (n = 15) from March 2013 to March 2017 were assessed. The mean follow-up period was 29.1 months. JOA, ODI, VAS and modified Macnab were assessed. Radiographic evaluations included lumbar lordosis angle, ISR value, operative and proximal adjacent ROM. Changes in intervertebral disc signal were classified according to Pfirrmann grade and UCLA system. RESULTS: JOA, ODI and VAS changed significantly after the operation to comparable levels between the groups. However, the lumbar lordosis significantly decreased at final follow-up between both groups. The ROM of the proximal adjacent segment increased at final follow-up, but the number of fixed segment ROMs in the K-Rod group were significantly lower at the final follow-up than observed prior to the operation. In both groups, the ISR of the proximal adjacent segment decreased, most notably in the rigid group. The ISR of the non-fusion fixed segments in the K-Rod group increased post-operation and during final follow-up. The levels of adjacent segment degeneration were higher in the rigid group vs. the K-Rod group according to modified Pfirrmann grading and the UCLA system. CONCLUSIONS: Compared with the rigid system for treatment of MDLSS, dynamic K-Rod stabilization achieves improved radiographic outcomes and improves the mobility of the stabilized segments, minimizing the influence on the proximal adjacent segment.

A comparison of long-term efficacy of K-rod-assisted non-fusion operation and posterior lumbar interbody fusion for single-segmental lumbar disc herniation.

K-rod-assisted non-fusion surgery for the treatment of lumbar disc herniation has been proven to have short-term clinical efficacy. Meanwhile, its long-term effects have not been examined. To observed the long-term clinical efficacy of K-rod-assisted non-fusion operation, this study retrospectively analyzed 22 patients with lumbar disc (L4/5) herniation who underwent K-rod-assisted non-fusion operation (n = 13) or PLIF (n = 9). They were followed-up for more than 5 years. The operation times and blood loss were significantly reduced in the K-rod group compared to the PLIF group. At the last follow-up, the clinical outcomes of the K-rod group were improved compared to those of the PLIF group as observed by the VAS score, JOABPEQ, and ODI. Imaging outcomes at the last follow-up indicated that the loss of height in the L3/4 and L5/S1 intervertebral space, the ROM of L3/4 and L5/S1, and the incidence of adjacent segment degeneration in the PLIF group were significantly higher than those in the K-rod group. According to Pfirrmann grading, Modic changes, and UCLA grading, the incidence of adjacent segment degeneration was 55.6% in the PLIF group and 15.4% in the K-rod group. Changes in spino-pelvic parameters between the two groups were as follows: pelvic index remained unchanged, pelvic tilt angle increased, and lumbar lordosis and sacral slope decreased. Therefore, compared to PLIF, single-segment lumbar disc herniation using K-rod-assisted non-fusion surgery resulted in better long-term clinical efficacy. Our results demonstrate that this procedure can delay adjacent segment degeneration after lumbar surgery.

Comparison of Clinical and Radiographic Results Between Posterior Pedicle-Based Dynamic Stabilization and Posterior Lumbar Intervertebral Fusion for Lumbar Degenerative Disease: A 2-Year Retrospective Study.

OBJECTIVE: To compare outcomes between K-rod dynamic stabilization system (KDSS) and posterior lumbar intervertebral fusion (PLIF) for lumbar degenerative disease. METHODS: This study retrospectively reviewed 98 patients who underwent lumbar surgery from March 2012 to June 2014, including 48 in the KDSS group and 50 in the PLIF group. All patients were followed up for at least 2 years. Duration of operation, blood loss, hospital stay, complications, and patient satisfaction were recorded and analyzed. Clinical outcomes were evaluated by visual analog scale and Oswestry Disability Index. Radiographic results including disk height index, foraminal height, and range of motion (ROM) were compared between groups. RESULTS: Compared with PLIF group, KDSS group had shorter duration of operation and less blood loss (P < 0.001). There were no differences in hospital stay, complications, and patient satisfaction. Both groups demonstrated significant improvement in visual analog scale back and leg pain and Oswestry Disability Index. No significant difference was found between groups at any time point (P > 0.05). Postoperative disk height index and foraminal height increased significantly compared with preoperatively (P < 0.05). Although disk height index and foraminal height in KDSS group were smaller than PLIF group values, there were no significant differences between groups. ROM of total lumbar and implanted segment was decreased compared with preoperative ROM in both groups (P < 0.05), but the 2 values were higher in KDSS group (P < 0.05). CONCLUSIONS: Both KDSS and PLIF can improve clinical and radiographic outcomes for early-stage lumbar degenerative disease. Compared with PLIF, KDSS has better operative time, less blood loss, and better preservation of ROM, but prospective, randomized, controlled trials with larger sample size and longer follow-up are required.

K-rod dynamic internal fixation versus microendoscopic discectomy for the treatment of single-segment lumbar disc herniation.

PURPOSE: This study compared the clinical outcome of K-rod dynamic internal fixation versus microendoscopic discectomy (MED) for the treatment of single-segment lumbar disc herniation. METHODS: This retrospective study included 34 patients with L4-L5 single-segment lumbar disc herniation who underwent K-rod dynamic internal fixation ( n = 18) or MED ( n = 16). The pain was evaluated by the Oswestry disability index (ODI) and visual analogue scale (VAS). The neurological function was assessed by the Japanese Orthopaedic Association (JOA) scores. The height of intervertebral space was calculated using X-ray images, and the disc degeneration was evaluated based on Pfirrmann scores. The mean follow-up time was 31 months (range, 18-46 months). RESULTS: In both groups, the ODI scores, VAS scores and JOA scores were significantly improved at the last follow-up compared with the preoperative values ( p < 0.05). There was no significant difference in the improvement of ODI, VAS and JOA scores between the two groups ( p > 0.05). The height of intervertebral space in the surgical segments, proximal segments and distal segments, was significantly greater in the K-rod group than in the MED group. The disc degeneration occurred more in the MED group than in the K-rod group ( p < 0.05). CONCLUSION: K-rod internal fixation and MED produce satisfactory outcomes in the treatment of single-segment lumbar disc herniation. K-rod internal fixation is superior to MED in preventing adjacent segment degeneration.

Biomechanical comparison of the K-ROD and Dynesys dynamic spinal fixator systems - a finite element analysis.

Dynamic spinal fixators, such as the Dynesys (DY) and K-ROD (KD) systems, are designed to restore spinal stability and to provide flexibility. The long-term complications of implant breakage and the biomechanics of the adjacent and the bridged levels using the KD system are still unknown. Therefore, this study aims to investigate and compare the biomechanical effects of the KD system and the DY system. Finite element (FE) models of the degenerated lumbar spine, the DY system, and the KD system were each reconstructed. Hybrid-controlled analysis was applied in the three FE models. The FE results indicated that the KD system supplies the most stiffness during extension and the least stiffness during flexion, in contrast to the DY system. In contrast to the DY system, the KD system increased the facet contact force of the adjacent level, but this system decreased the screw stress on the cranial adjacent disc and the pedicle during flexion.