Tissue response following implantation with the posterior dynamic distraction device (PDDD) in adolescent idiopathic scoliosis (AIS)

PURPOSE

The PDDD is a ratchet-based, unidirectional expandable rod to treat adolescent idiopathic scoliosis (AIS), primarily by correcting scoliotic deformity without full spinal fusion. We hypothesized that the device will be fully tolerated by the host and, if aseptic screw loosening occurs, it will be unrelated to wear particle formation.

METHODS

This study comprised tissue samples from seven patients from a prospective study (NCT04296903) to assess the PDDD's safety and benefits, reoperated due to complications. Host response was assessed from histological slides (four levels/implant) in accordance with GLP and ISO10993-6:2016. The elementary chemical composition of wear particles present in tissue sections was quantified by energy dispersive X-ray spectroscopy (EDX).

RESULTS

Host reaction was minor, characterized by low levels of diverse inflammatory cells, mild fibrosis, occasional small necrotic foci, neovascularization, hemorrhage, and, rarely, small bone fragments. Twenty-four of 28 tissue sections displayed varying degrees of wear particles (black discoloration), and most sections (17) were scored as 1 (< 25% of the sample). The discoloration observed corresponded to black-appearing, fine granular pigment. EDX analysis confirmed particles were composed of titanium, aluminum, and vanadium. Twenty-six of 28 samples were scored zero for necrosis and 2/28 were scored 1. Eleven samples were scored zero for fibrosis, 12 as 1, and five as 2. No aseptic screw loosening occurred.

CONCLUSION

The PDDD induced minimal host reaction with little or no degeneration, inflammation or fibrosis. No changes present could be expected to promote device failure. The PDDD implant for treating AIS is well-tolerated and locally safe.

Factors associated with non-fusion after direct pars repair of lumbar spondylolysis with pedicle screw and lamina hook: a clinical and CT-assessed study

BACKGROUND

Pedicle screw and lamina hook (PSLH) technique is an effective and popular method for direct pars repair of lumbar spondylolysis. There is a lack of studies to explore factors that may influence the healing of spondylolysis after direct pars repair surgery. The present study aimed to investigate the factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PSLH technique.

METHODS

A total of 55 subjects (average age 21.1 ± 6.3 years, a total of 120 pars defects) diagnosed with symptomatic spondylolysis and underwent pars repair surgery with PSLH were followed up and their clinical data were analyzed. Subjects were divided into a non-fusion group and fusion group according to whether the pars defect had bony fusion at last follow-up assessed by CT. Radiographic data, data related to spondylolysis and clinical outcomes were collected and compared between groups.

RESULTS

The mean follow-up time of the 55 patients was 24.8 ± 12.0 (12-64) months. Among the 120 pars defects, 101 defects were successfully fused and 19 were not fused according to CT. The fusion rate was 84.2%. Multivariable logistic regression analysis showed the factors correlated with non-fusion after pars repair surgery: whether the spondylolysis segment was associated with spina bifida occulta (SBO) (P = 0.001), stage of the defect (P = 0.047), width of the defect (P = 0.002), and disc degeneration (P = 0.014).

CONCLUSION

Direct pars repair by PSHL is a reliable treatment for lumbar spondylolysis with a fusion rate of 84.2%. Association with SBO of the spondylolysis segment, a terminal stage of the defect, a wider defect gap, and grade III disc degeneration may be factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PLSH. Non-fusion patients after pars repair appear to have worse clinical results compared to fusion patients.

Bilateral vertebral body tethering: identifying key factors associated with successful outcomes

PURPOSE

The treatment of operative double major pediatric spinal deformities (e.g., Lenke 3 or 6) with bilateral vertebral body tethering (VBT) can be significantly more challenging when compared to other deformity patterns (e.g., Lenke 1) or treatment with a posterior spinal fusion. We aimed to identify preoperative and perioperative characteristics that were associated with successful postoperative outcomes in patients treated with both a thoracic and thoracolumbar (e.g., bilateral) tether.

METHODS

We retrospectively assessed radiographic and clinical data from patients enrolled in a large multi-center study who had a minimum postoperative follow-up of two years. Standard radiographic parameters were extracted from standing spine and left hand-wrist radiographs at various timepoints. We classified patients based on their preoperative deformity pattern (Primary Thoracic [TP] vs. Primary Thoracolumbar [TLP]) and assessed: (1) deformity balance, (2) tilt of the transitional vertebra, and (3) postoperative success.

RESULTS

We analyzed data from thirty-six patients (TP: 19 and TLP: 17). We observed no relationship between deformity balance at first erect and postoperative success (p = 0.354). Patients with a horizontal transitional vertebra at first erect were significantly (p = 0.001) more likely to exhibit a successful outcome when compared to those who exhibited a tilted transitional vertebra (83% vs. 62%). Patients who had TLP were also more likely to exhibit a successful outcome when compared to patients who exhibited TP (76% vs. 50%).

CONCLUSION

These data indicate that double major deformities can be successfully treated with VBT, particularly for those who exhibit TLP.

[Research progress of Wallis dynamic stabilization system for lumbar degenerative diseases]

Wallis dynamic stabilization system is a surgical approach in the non-fusion technique of lumbar spine, consisting of interspinous blockers and dacron artificial ligaments that provide stability to the spine while maintaining a degree of motion in the affected segment. Recent studies have demonstrated the significant benefits of Wallis dynamic stabilization system in treating lumbar degenerative diseases. It not only improves clinical symptoms, but also effectively delays complications such as adjacent segmental degeneration. This paper aims to review the literature related to the Wallis dynamic stabilization system and degenerative diseases of the lumbar spine to describe the long-term prognostic effect of this system in the treatment of such diseases. This review provides a theoretical basis and reference for selecting surgical methods to treat degenerative diseases of the lumbar spine.

Three-dimensional correction of scoliosis by a double spring reduction system as a dynamic internal brace: a pre-clinical study in Göttingen minipigs

BACKGROUND CONTEXT

Adolescent idiopathic scoliosis (AIS) is a major skeletal deformity that is characterized by a combination of apical rotation, lateral bending and apical lordosis. To provide full 3D correction, all these deformations should be addressed. We developed the Double Spring Reduction (DSR) system, a (growth-friendly) concept that continuously corrects the deformity through two different elements: A posterior convex Torsional Spring Implant (TSI) that provides a derotational torque at the apex, and a concave Spring Distraction System (SDS), which provides posterior, concave distraction to restore thoracic kyphosis.

PURPOSE

To determine whether the DSR components are able to correct an induced idiopathic-like scoliosis and to compare correction realized by the TSI alone to correction enforced by the complete DSR implant.

STUDY DESIGN/SETTING

Preclinical randomized animal cohort study.

PATIENT SAMPLE

Twelve growing Göttingen minipigs.

OUTCOME MEASURES

Coronal Cobb angle, T10-L3 lordosis/kyphosis, apical axial rotation, relative anterior lengthening.

METHODS

All mini-pigs received the TSI with a contralateral tether to induce an idiopathic-like scoliosis with apical rotation (mean Cobb: 20.4°; mean axial apical rotation: 13.1°, mean lordosis: 4.9°). After induction, the animals were divided into two groups: One group (N=6) was corrected by TSI only (TSI only-group), another group (N=6) was corrected by a combination of TSI and SDS (DSR-group). 3D spinal morphology on CT was compared between groups over time. After 2 months of correction, animals were euthanized.

RESULTS

Both intervention groups showed excellent apical derotation (TSI only-group: 15.0° to 5.4°; DSR-group: 11.2° to 3.5°). The TSI only-group showed coronal Cobb improvement from 22.5° to 6.0°, while the DSR-group overcorrected the 18.3° Cobb to -9.2°. Lordosis was converted to kyphosis in both groups (TSI only-group: -4.6° to 4.3°; DSR-group: -5.2° to 25.0°) which was significantly larger in the DSR-group (p<.001).

CONCLUSIONS

The TSI alone realized strong apical derotation and moderate correction in the coronal and sagittal plane. The addition of distraction on the posterior concavity resulted in more coronal correction and reversal of induced lordosis into physiological kyphosis.

CLINICAL SIGNIFICANCE

This study shows that dynamic spring forces could be a viable method to guide the spine towards healthy alignment, without fusing it or inhibiting its growth.

Operative differences for posterior spinal fusion after vertebral body tethering: Are we fusing more levels in the end?

PURPOSE

Little is known about the perioperative characteristics associated with a posterior spinal fusion (PSF) in adolescent idiopathic scoliosis patients previously treated with vertebral body tethering (VBT). We aimed to determine if operative time, estimated blood loss, postoperative length of stay, instrumentation type, and implant density differed in patients that received a PSF (i.e., PSF-Only) or a PSF following a failed VBT (i.e., PSF-VBT).

METHODS

We retrospectively assessed matched cohort data (PSF-VBT = 22; PSF-Only = 22) from two multi-center registries. We obtained: (1) operative time, (2) estimated blood loss, (3) postoperative length of stay, (4) instrumentation type, and (5) implant density. Theoretical fusion levels prior to the index procedure were obtained for PSF-VBT and compared to the actual levels fused.

RESULTS

We observed no difference in operative time, estimated blood loss, or postoperative length of stay. Instrumentation type was all-screw in PSF-Only and varied in PSF-VBT with nearly 25% of patients exhibiting a hybrid construct. There was no added benefit to removing anterior instrumentation prior to fusion; however, implant density was higher in PSF-Only (1.9 ± 0.2) than when compared to PSF-VBT (1.7 ± 0.3). An additional two levels were fused in 50% of PSF-VBT patients, most of which were added to the distal end of the construct.

CONCLUSIONS

We found that operative time, estimated blood loss, and postoperative length of stay were similar in both cohorts; however, the length of the fusion construct in PSF-VBT is likely to be two levels longer when a failed VBT is converted to a PSF.

The preliminary outcomes of vertebral body tethering in treating adolescent idiopathic scoliosis: a systematic review

PURPOSE

VBT is a novel alternative to spinal fusion surgery to treat skeletally immature AIS and was approved to correct idiopathic scoliosis in August 2019 by US Federal Drug Administration (FDA). To systemically review the preliminary outcomes of vertebral body tethering (VBT) in treating adolescent idiopathic scoliosis.

METHODS

The electronic databases PubMed, EMBASE, and Web of Science were queried up to January 2022 for articles regarding VBT. Basic characteristics of patients, changes of radiographic parameters in coronal and sagittal planes, and clinical outcomes of surgical treatment of VBT including complication and revision rates were summarized.

RESULTS

Twenty five studies met the inclusion criteria. Most studies (23/25) included patients with only skeletal immaturity. The average % correction of the main/tethered curve at final follow-up, and % correction of thoracic kyphosis at final follow-up were reported to be 15.6-106.5% and - 31.8 to 20.0%, respectively. The most common complications for VBT were tether breakage (n = 145;21.3%), pulmonary complications (n = 49; 6.9%), and overcorrection (n = 30; 4.2%). The revision rate was 13.1%.

CONCLUSION

VBT could effectively and safely correct spinal deformity in skeletally immature patients with AIS and preserve the motion and growth of the spine. However, VBT has a relatively high complication and revision rates. Therefore, surgeons should cautiously consider VBT for treating AIS. Future research efforts are needed to lower the complication and revision rates. Whatever, VBT is still in its infancy and may have a promising future as a non-fusion solution for AIS.

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.

The effect of non-fusion dynamic stabilization on biomechanical responses of the implanted lumbar spine during whole-body vibration

BACKGROUND AND OBJECTIVE

Non-fusion dynamic stabilization surgery is increasingly popular for treating degenerative lumbar disc disease. However, changes in spine biomechanics after application of posterior dynamic fixation devices during whole-body vibration (WBV) remain unclear. The study aimed to examine the effects of non-fusion dynamic stabilization on biomechanical responses of the implanted lumbar spine to vertical WBV.

METHODS

By modifying L4-L5 segment of the healthy human L1-sacrum finite element model, single-level disc degeneration, dynamic fixation using the BioFlex system and anterior lumbar interbody fusion (ALIF) with rigid fixation were simulated, respectively. Dynamic responses of stress and strain in the spinal levels for the healthy, degenerated, BioFlex and ALIF models under an axial cyclic loading were investigated and compared.

RESULTS

The results showed that endplate stress at implant level was lower in the BioFlex model than in the degenerated and ALIF models, but stress of the connecting rod in the BioFlex system was greater than that in the rigid fixation system used in the ALIF. Compared with the healthy model, stress and strain responses in terms of disc bulge, annulus stress and nucleus pressure at adjacent levels were decreased in the degenerated, BioFlex and ALIF models, but no obvious difference was observed in these responses among the three models.

CONCLUSIONS

This study may be helpful to understand variations in vibration characteristics of the lumbar spine after application of non-fusion dynamic stabilization system.

Design and preliminary biomechanical analysis of a novel motion preservation device for lumbar spinal disease after vertebral corpectomy

OBJECTIVE

To design a novel prosthesis, a movable artificial lumbar complex (MALC), for non-fusion reconstruction after lumbar subtotal corpectomy and to evaluate the stability, range of motion and load-bearing strength in the human cadaveric lumbar spine.

METHODS

Biomechanical tests were performed on lumbar spine specimens from 15 healthy cadavers which were divided in three groups: non-fusion, fusion and intact group. The range of motion (ROM), stability and load-bearing strength were measured.

RESULTS

The prosthesis was composed of three parts: the upper and lower artificial lumbar discs and the middle artificial vertebra. Both the MALC and titanium mesh cage re-established vertebral height, and no spinal cord compression or prosthesis dislocation was observed at the operative level. Regarding stability, there was no significant difference in all directions between the intact group and non-fusion group (P > 0.05). Segment movements of the specimens in the non-fusion group revealed significantly decreased T12-L1 ROM and significantly increased L1-2 and L2-3 ROM in flexion/extension and lateral bending compared with those in the fusion group (P < 0.05). Regarding load-bearing strength, when the lumbar vertebra was ruptured, there was no damage to the MALC and titanium mesh cage, but the maximum load in the non-fusion group was larger (P > 0.05).

CONCLUSIONS

Compared with titanium cages, the MALC prosthesis not only restored the vertebral height and effectively preserved segment movements without any abnormal gain of mobility in adjacent inter-vertebral spaces but also bore the lumbar load and reduced the local stress load of adjacent vertebral endplates.

Preclinical evaluation of a novel anterior non-fusion fixation device for atlantoaxial instability: an in vivo comparison study in a canine model

PURPOSE

The Anterior Atlantoaxial Non-Fusion Fixation System (AANFS) was a novel motion preservation device for atlantoaxial instability to replace traditional fusion techniques. The purpose of this in vivo study was to evaluate the clinical features and biomechanical properties of this new device in a canine model by comparing it with a conventional method.

METHODS

Eighteen adult male canines were randomly divided into group 1, which received the AANFS replacement, group 2 which received the Harms rigid fixation procedures, and group 3, which served as the control group. Routine follow-up evaluations were performed postoperatively. Specimens were harvested 12 weeks after the operation. Biomechanical tests were conducted to obtain the range of motion (ROM) and neutral zone (NZ) at C1-C2 segment in different groups.

RESULTS

The canines successfully tolerated the entire experimental procedure. No significant differences were found in surgery time, blood loss and recovery time between the AANFS group and the Harms rigid fixation group. Radiological examinations revealed that the position of the implant was good. Biomechanical results showed that, compared with the intact group, the mean ROM and NZ in flexion, extension, lateral bending and rotation were significantly reduced after rigid fixation. However, after the AANFS implantation, ROM and NZ in all directions were similar to those of the intact state.

CONCLUSIONS

This study for the first time provides an animal model for studying non-fusion strategies of upper cervical spine. The AANFS was able to maintain movement function of the atlantoaxial joint and may be an alternative to traditional fusion techniques. These slides can be retrieved under Electronic Supplementary Material.

Dynamic Fusion Process in the Anterior Cervical Discectomy and Fusion with Self-Locking Stand-Alone Cages

BACKGROUND

Self-locking stand-alone cages can achieve satisfactory clinical results and fusion rate. However, there have been no reports on the causes and relationship of different fusion state. This study is to classify the different fusion states of the index level and to explore the potential contributing factors and links of them.

METHODS

From June 2008 to October 2011, 42 patients underwent anterior cervical discectomy and fusion with MC+ cages. More than 5 years' follow-up was reviewed. The fusion state and the relevant clinical and radiologic records were reviewed retrospectively.

RESULTS

At the last follow-up, the fusion proportion of type I, II, III, and IV was 11.7%, 16.9%, 26.9%, and 42.9%, respectively. The overall fusion rate was 97.4%. For all the fused types, significant improvement for the visual analog scale, Japanese Orthopaedic Association, and Neck Disability Index scores was found at the last follow-up (P < 0.05). However, there were no significant differences between the 4 types (P > 0.05). For sagittal vertical axis, type IV was significantly larger than that of type I, II, and III (P < 0.05), and for range of motion, type III was significantly larger than that of type II and IV (P < 0.05).

CONCLUSIONS

For anterior cervical discectomy and fusion with self-locking stand-alone cages, the fusion of the index level seems to be a progressive dynamic process during the mid-term follow-up, which may be influenced by the location of the cage, the aagittal vertical axis of the index level, and the global range of motion of the cervical spine. Satisfactory clinical results could be achieved by all the fused types.

The surgical outcome of Lisfranc injuries accompanied by multiple metatarsal fractures: A multicenter retrospective study

BACKGROUND

This study assessed the surgical outcomes of Lisfranc injuries accompanied by multiple metatarsal fractures. Metatarsal fractures here refers to metatarsal head, neck, and shaft (including shaft fractures accompanied by fractures of the base) fractures, as well as mixed (i.e., segmental fracture) fractures, as seen on imaging studies.

METHODS

Between 2002 and 2015, one hundred and seventy-six patients were followed-up for a mean of 92 months, including eight patients who underwent secondary arthrodesis due to severe arthritis after ORIF. All the patients underwent surgical fusion (primary partial arthrodesis, PPA; n = 78) or non-fusion (percutaneous or open reduction and internal fixation, ORIF; n = 98) procedures and the outcomes were evaluated by clinical examinations, radiography, visual analogue scale (VAS) pain score, the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score, the Foot and Ankle Outcome Score (FAOS), and the Short Form (SF)-36 physical and SF-36 mental questionnaires. The parameters between the fusion and non-fusion groups were analyzed by repeated-measures ANOVA. Statistically significant differences between the two groups were then further analyzed using a two-independent-samples t-test.

RESULTS

Anatomical reduction was achieved in 161 patients. At the last follow-up, the mean AOFAS score was 74.67 (range: 39-91) in the non-fusion group and 82.79 (range: 67-97) in the fusion group (P = 0.003). The PPA and ORIF groups differed significantly with respect to the VAS pain score (1.93 vs. 1.21), the SF-36 physical (75.87 vs. 80.90) and mental (75.76 vs. 81.33) components, and the FAOS pain (72.74 vs. 84.06), symptoms (71.87 vs. 82.49), activities of daily life (ADLs: 73.12 vs. 81.54), sport/recreation (sport/rec: 57.99 vs. 73.23), and quality of life (QoL: 79.95 vs. 86.67) components. In the ORIF group, 23 patients had mild/moderate post-traumatic osteoarthritis.

CONCLUSIONS

With longer and more conservative postoperative management, fusion results in a better outcome than non-fusion in the treatment of Lisfranc injuries accompanied by multiple metatarsal fractures.

Comparison of Arthrodesis and Non-fusion to Treat Lisfranc Injuries

OBJECTIVE

"Lisfranc joint injury" is comprised of a tarsometatarsal joint-complex injury. The Lisfranc complex injury is always a challenge for orthopedists, and the optimum treatment is still up for debate. Anatomic reduction and stable internal fixation prove to have no satisfactory outcomes. This research aims to compare the clinical curative effects, complications and radiographic features of arthrodesis and non-fusion of the Lisfranc joint in the follow-up of the patients who suffered Lisfranc injuries.

METHODS

A comparative retrospective study of 25 patients with acute or subacute Lisfranc complex injuries was conducted between September 2013 and March 2015 in the First Affiliated Hospital of Soochow University. All patients were classified by Myerson classification. Eight patients were treated with arthrodesis, while 17 patients received non-fusion operations. The clinical curative effects, complications and image differences were compared between the two groups. American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, Short Form-36 (SF-36) and Visual Analogue Scale (VAS) score were evaluated for each patient during the follow-up. All statistics were analyzed using the SPSS software system.

RESULTS

All fractures healed for both the arthrodesis group and the non-fusion group. Patients in the arthrodesis group had a higher AOFAS score compared with patients in the non-fusion group (94.00 vs. 88.58, P = 0.034). Complications occurred in eight patients (8/17, 47%) in the non-arthrodesis group, including the second and third phalanx abduction (1), talipes cavus (2), eversion deformity of front foot (3), eversion deformity of calcaneus (1), as well as postoperative infection (1). Only two patients (2/8, 25%) in the arthrodesis group suffered complications. One was a limitation of motion of the front foot and pain during walking; the other was an eversion deformity of front foot.

CONCLUSION

Primary arthrodesis has advantages compared to primary open reduction and internal fixation (ORIF): reduced foot deformity rates, sustained biomechanical morphology of the feet, reduced complications, higher level of function recovery, shorter time of surgical procedures, fewer complications, higher AOFAS score and fewer frequency of complications. According to our research, primary arthrodesis may be a better choice for treating Lisfranc injury.

Clinical Experiences of Non-fusion Dynamic Stabilization Surgery for Adjacent Segmental Pathology after Lumbar Fusion

BACKGROUND

As an alternative to spinal fusion, non-fusion dynamic stabilization surgery has been developed, showing good clinical outcomes. In the present study, we introduce our surgical series, which involves non-fusion dynamic stabilization surgery for adjacent segment pathology (ASP) after lumbar fusion surgery.

METHODS

Fifteen patients (13 female and 2 male, mean age of 62.1 years) who underwent dynamic stabilization surgery for symptomatic ASP were included and medical records, magnetic resonance images (MRI), and plain radiographs were retrospectively evaluated.

RESULTS

Twelve of the 15 patients had the fusion segment at L4-5, and the most common segment affected by ASP was L3-4. The time interval between prior fusion and later non-fusion surgery was mean 67.0 months. The Visual Analog Scale and Oswestry Disability Index showed values of 7.4 and 58.5% before the non-fusion surgery and these values respectively declined to 4.2 and 41.3% postoperatively at 36 months (p=0.027 and p=0.018, respectively). During the mean 44.8 months of follow-up, medication of analgesics was also significantly reduced. The MRI grade for disc and central stenosis identified significant degeneration at L3-4, and similar disc degeneration from lateral radiographs was determined at L3-4 between before the prior fusion surgery and the later non-fusion surgery. After the non-fusion surgery, the L3-4 segment and the proximal segment of L2-3 were preserved in the disc, stenosis and facet joint whereas L1-2 showed disc degeneration on the last MRI (p=0.032). Five instances of radiologic ASP were identified, showing characteristic disc-space narrowing at the proximal segments of L1-2 and L2-3. However, no patient underwent additional surgery for ASP after non-fusion dynamic stabilization surgery.

CONCLUSION

The proposed non-fusion dynamic stabilization system could be an effective surgical treatment for elderly patients with symptomatic ASP after lumbar fusion.

Short-term effects of a dynamic neutralization system (Dynesys) for multi-segmental lumbar disc herniation

PURPOSE

To determine the safety and short-term curative effects of internal fixation using a dynamic neutralization system (Dynesys) for multi-segmental lumbar disc herniation (ms-LDH) with the control group treated by posterior lumbar interbody fusion (PLIF).

METHODS

Forty-five patients with ms-LDH were selected as study group treated with Dynesys and 40 patients as control group with PLIF. The surgical efficacy was evaluated by comparing the visual analogue scale (VAS) scores, the Oswestry Disability Index (ODI) scores and the ROMs of the adjacent segment before and after surgery. The postoperative complications related to the implants were identified.

RESULTS

All patients were followed up for an average duration of over 30 months. Dynesys stabilization resulted in significantly higher preservation of motion at the index level (p < 0.001), and significantly less (p < 0.05) hypermobility at the adjacent segments. VAS for back and leg pain and ODI improved significantly (p < 0.05) with both the methods, but there was no significant difference between the groups.

CONCLUSIONS

The non-fusion fixation system Dynesys is safe and effective regarding short-term curative effects for the treatment of ms-LDH.

Hybrid Surgery Combined with Dynamic Stabilization System and Fusion for the Multilevel Degenerative Disease of the Lumbosacral Spine

BACKGROUND

As motion-preserving technique has been developed, the concept of hybrid surgery involves simultaneous application of two different kinds of devices, dynamic stabilization system and fusion technique. In the present study, the application of hybrid surgery for lumbosacral degenerative disease involving two-segments and its long-term outcome were investigated.

METHODS

Fifteen patients with hybrid surgery (Hybrid group) and 10 patients with two-segment fusion (Fusion group) were retrospectively compared.

RESULTS

Preoperative grade for disc degeneration was not different between the two groups, and the most common operated segment had the most degenerated disc grade in both groups; L4-5 and L5-S1 in the Hybrid group, and L3-4 and L4-5 in Fusion group. Over 48 months of follow-up, lumbar lordosis and range of motion (ROM) at the T12-S1 global segment were preserved in the Hybrid group, and the segmental ROM at the dynamic stabilized segment maintained at final follow-up. The Fusion group had a significantly decreased global ROM and a decreased segmental ROM with larger angles compared to the Hybrid group. Defining a 2-mm decrease in posterior disc height (PDH) as radiologic adjacent segment pathology (ASP), these changes were observed in 6 and 7 patients in the Hybrid and Fusion group, respectively. However, the last PDH at the above adjacent segment had statistically higher value in Hybrid group. Pain score for back and legs was much reduced in both groups. Functional outcome measured by Oswestry disability index (ODI), however, had better improvement in Hybrid group.

CONCLUSION

Hybrid surgery, combined dynamic stabilization system and fusion, can be effective surgical treatment for multilevel degenerative lumbosacral spinal disease, maintaining lumbar motion and delaying disc degeneration.

Minimum 5 year follow-up of multi-segmental lumbar degenerative disease treated with discectomy and the Wallis interspinous device. J Clin Neurosci. 2015;22:1144-1149. [PMID: 25890774 DOI: 10.1016/j.jocn.2014.12.016]

We evaluate the clinical effects and radiological findings of the Wallis interspinous device (Zimmer, Warsaw, IN, USA) for the treatment of multi-segmental lumbar degenerative disease after a minimum 5 year follow-up period. A total of 26 adult patients underwent a primary discectomy followed by fixation of the segment with the Wallis interspinous device between December 2007 and August 2008. Twelve men and 14 women with an age range of 43 to 56 years (average: 47.6) were included. The visual analogue scale (VAS) for low back and leg pain, Oswestry Disability Index (ODI), foraminal height (FH), anterior disc height (aDH) and posterior disc height (pDH), range of motion (ROM) and Pfirrmann grades were obtained and compared before and after surgery. The VAS and ODI significantly decreased postoperatively (p < 0.05). The postoperative FH and pDH values increased significantly compared with the preoperative levels (p < 0.01) and the increase in the FH and pDH values remained statistically significant during the follow-up period. There were no statistically significant changes in the aDH values before and after surgery (p > 0.05). Also, there were no statistically significant changes in the ROM and Pfirrmann grade at the instrumented level and at the cephalad-adjacent segment (p>0.05). In our study, no patient underwent further surgery because of a re-prolapse or progression of index level degeneration or adjacent segment disease. The Wallis interspinous device was a useful alternative for treating multi-segmental lumbar degenerative disease and it offered a significant minimum 5 year symptom control.

Complete testicular epididymal dissociation in the abdominal cryptorchid testis

AIM

To document the incidence of complete testicular epididymal dissociation (CTED) in the cryptorchid testis and evaluate its operative outcome.

METHODS

The presence of CTED was noted prospectively in cases of undescended testis and the operative findings were studied.

RESULTS

CTED was encountered in 11 testes in 10 boys out of 29 intra-abdominal testes among the 142 undescended testes (8%) operated. Ages of patients varied from 18 months-14 years (median 4.5 years). All 11 testes were intra-abdominal. In 5 out of 11 testes, the dissociation was associated with a wide separation of the epididymis and testis. The dissociated epididymis was in the scrotum attached to the gubernaculum while the testis was intra-abdominal. One case had bilateral CTED. Successful subdartos orchidopexy was done for 8 testes, 6 after Prentiss maneuver. Two gonads were fixed just below the pubic tubercle. Orchiectomy was done in one case with a small sized testis with a short gonadal vessel.

CONCLUSION

CTED was encountered in 8% of cases of cryptorchidism. A palpable nubbin-like tissue in the scrotal sac in the presence of CTED may suggest a descended dissociated epididymis with an intra-abdominal testis. Successful subdartos orchidopexy was possible in 73% of testes with CTED.

Open Reduction without Fusion of Bilateral Jumped Lumbosacral Facet Dislocation Associated with Symphysis Pubis Separation and Cauda Equina Syndrome: Case Report

This paper reports a rare case of a lumbosacral dislocation associated with symphysis pubis separation and cauda equina syndrome. A 39-year-old male who diagnosed traumatic lumbosacral dislocation underwent an open reduction without fusion. After an open reduction and internal fixation of a symphysis pubis separation, a missed lumbosacral dislocation was diagnosed and an open reduction was performed without fusion. Due to the symphysis pubis separation, the patient was not allowed weight bearing for 3 months, which then began from wheel chair ambulation. At the 6-month follow up evaluation, there was no back pain but the patient reported mild S1 nerve root sensory symptoms. Lumbosacral dislocation is common in high energy polytrauma patients and can be misdiagnosed. However, prompt reduction without fusion is a good alternative treatment.