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BMC Surgery May 2024Whether polyetheretherketone (PEEK) rods have potential as an alternative to titanium alloy (Ti) rods in transforaminal lumbar interbody fusion (TLIF) remains unclear,... (Comparative Study)
Comparative Study
BACKGROUND
Whether polyetheretherketone (PEEK) rods have potential as an alternative to titanium alloy (Ti) rods in transforaminal lumbar interbody fusion (TLIF) remains unclear, especially in cases with insufficient anterior support due to the absence of a cage. The purpose of this study was to investigate biomechanical differences between PEEK rods and Ti rods in TLIF with and without a cage.
METHODS
An intact L1-L5 lumbar finite element model was constructed and validated. Accordingly, four TLIF models were developed: (1) Ti rods with a cage; (2) PEEK rods with a cage; (3) Ti rods without a cage; and (4) PEEK rods without a cage. The biomechanical properties were then compared among the four TLIF constructs.
RESULTS
With or without a cage, no obvious differences were found in the effect of PEEK rods and Ti rods on the range of motion, adjacent disc stress, and adjacent facet joint force. Compared to Ti rods, PEEK rods increase the average bone graft strain (270.8-6055.2 µE vs. 319.0-8751.6 µE). Moreover, PEEK rods reduced the stresses on the screw-rod system (23.1-96.0 MPa vs. 7.2-48.4 MPa) but increased the stresses on the cage (4.6-35.2 MPa vs. 5.6-40.9 MPa) and endplates (5.7-32.5 MPa vs. 6.6-37.6 MPa).
CONCLUSIONS
Regardless of whether a cage was used for TLIF, PEEK rods theoretically have the potential to serve as an alternative to Ti rods because they may provide certain stability, increase the bone graft strain, and reduce the posterior instrumentation stress, which might promote bony fusion and decrease instrumentation failure.
Topics: Benzophenones; Titanium; Ketones; Polymers; Finite Element Analysis; Polyethylene Glycols; Humans; Spinal Fusion; Biomechanical Phenomena; Lumbar Vertebrae; Alloys; Range of Motion, Articular; Biocompatible Materials
PubMed: 38811965
DOI: 10.1186/s12893-024-02462-8 -
BMC Musculoskeletal Disorders May 2024The emerging of the C2 isthmus screw fixation technique is gaining popularity in the setting of atlantoaxial dislocation or other conditions requiring fixation of C2....
BACKGROUND
The emerging of the C2 isthmus screw fixation technique is gaining popularity in the setting of atlantoaxial dislocation or other conditions requiring fixation of C2. However, the biomechanical stability of this fixation is poorly understood.
PURPOSE
To compare and elucidate the biomechanical stability of C2 pedicle screw (C2PS), C2 isthmus screw (C2IS) and C2 short isthmus screw (C2SIS) fixation techniques in atlantoaxial dislocation (AAD).
METHOD
A three-dimensional finite element model (FEM) from occiput to C3 was established and validated from a healthy male volunteer. Three FEMs, C1 pedicle screw (PS)-C2PS, C1PS-C2IS, C1PS-C2SIS were also constructed. The range of motion (ROM) and the maximum von Mises stress under flexion, extension, lateral bending and axial rotation loading were analyzed and compared. The pullout strength of the three fixations for C2 was also evaluated.
RESULT
C1PS-C2IS model showed the greatest decrease in ROM with flexion, extension, lateral bending and axial rotation. C1PS-C2PS model showed the least ROM reduction under all loading conditions than both C2IS and C2SIS. The C1PS-C2PS model had the largest von Mises stress on the screw under all directions followed by C1PS-C2SIS, and lastly the C1PS-C2IS. Under axial rotation and lateral bending loading, the three models showed the maximum and minimum von Mises stress on the screw respectively. The stress of the three models was mainly located in the connection of the screw and rod. Overall, the maximum screw pullout strength for C2PS, C2IS and C2SIS were 729.41N, 816.62N, 640.54N respectively.
CONCLUSION
In patients with atlantoaxial dislocations, the C2IS fixation provided comparable stability, with no significant stress concentration. Furthermore, the C2IS had sufficient pullout strength when compared with C2PS and C2SIS. C2 isthmus screw fixation may be a biomechanically favourable option in cases with AAD. However, future clinical trials are necessary for the evaluation of the clinical outcomes of this technique.
Topics: Humans; Finite Element Analysis; Atlanto-Axial Joint; Male; Biomechanical Phenomena; Joint Dislocations; Range of Motion, Articular; Adult; Pedicle Screws; Bone Screws; Spinal Fusion
PubMed: 38811940
DOI: 10.1186/s12891-024-07470-6 -
Journal of Orthopaedic Surgery and... May 2024Nonfusion technologies, such as motion-preservation devices, have begun a new era of treatment options in spine surgery. Motion-preservation approaches mainly include...
BACKGROUND
Nonfusion technologies, such as motion-preservation devices, have begun a new era of treatment options in spine surgery. Motion-preservation approaches mainly include total disc replacement for anterior cervical discectomy and fusion. However, for multisegment fusion, such as anterior cervical corpectomy and fusion, the options are more limited. Therefore, we designed a novel 3D-printed motion-preservation artificial cervical corpectomy construct (ACCC) for multisegment fusion. The aim of this study was to explore the feasibility of ACCC in a goat model.
METHODS
Goats were treated with anterior C3 corpectomy and ACCC implantation and randomly divided into two groups evaluated at 3 or 6 months. Radiography, 3D CT reconstruction and MRI evaluations were performed. Biocompatibility was evaluated using micro-CT and histology.
RESULTS
Postoperatively, all goats were in good condition, with free neck movement. Implant positioning was optimal. The relationship between facet joints was stable. The range of motion of the C2-C4 segments during flexion-extension at 3 and 6 months postoperatively was 7.8° and 7.3°, respectively. The implants were wrapped by new bone tissue, which had grown into the porous structure. Cartilage tissue, ossification centres, new blood vessels, and bone mineralization were observed at the porous metal vertebrae-bone interface and in the metal pores.
CONCLUSIONS
The ACCC provided stabilization while preserving the motion of the functional spinal unit and promoting bone regeneration and vascularization. In this study, the ACCC was used for anterior cervical corpectomy and fusion (ACCF) in a goat model. We hope that this study will propel further research of motion-preservation devices.
Topics: Animals; Goats; Cervical Vertebrae; Printing, Three-Dimensional; Spinal Fusion; Range of Motion, Articular; Models, Animal; Biocompatible Materials; Materials Testing; Time Factors; Diskectomy
PubMed: 38807224
DOI: 10.1186/s13018-024-04786-w -
BMC Musculoskeletal Disorders May 2024It was reported the paraspinal muscle played an important role in spinal stability. The preoperative paraspinal muscle was related to S1 screw loosening. But the...
BACKGROUND
It was reported the paraspinal muscle played an important role in spinal stability. The preoperative paraspinal muscle was related to S1 screw loosening. But the relationship between preoperative and postoperative change of psoas major muscle (PS) and S1 pedicle screw loosening in degenerative lumbar spinal stenosis (DLSS) patients has not been reported. This study investigated the effects of preoperative and follow-up variations in the psoas major muscle (PS) on the first sacral vertebra (S1) screw loosening in patients with DLSS.
METHODS
212 patients with DLSS who underwent lumbar surgery were included. The patients were divided into the S1 screw loosening group and the S1 screw non-loosening group. Muscle parameters were measured preoperatively and at last follow-up magnetic resonance imaging. A logistic regression analysis was performed to investigate the risk factors for S1 screw loosening.
RESULTS
The S1 screw loosening rate was 36.32% (77/212). The relative total cross-sectional areas and relative functional cross-sectional areas (rfCSAs) of the PS at L2-S1 were significantly higher after surgery. The increased rfCSA values of the PS at L3-S1 in the S1 screw non-loosening group were significantly higher than those in the S1 screw loosening group. The regression analysis showed male, lower CT value of L1 and longer segment fusion were independent risk factors for S1 screw loosening, and postoperative hypertrophy of the PS was a protective factor for S1 screw loosening.
CONCLUSIONS
Compared to the preoperative muscle, the PS size increased and fatty infiltration decreased after surgery from L2-3 to L5-S1 in patients with DLSS after short-segment lumbar fusion surgery. Postoperative hypertrophy of the PS might be considered as a protective factor for S1 screw loosening. MRI morphometric parameters and postoperative selected exercise of PS for DLSS patients after posterior lumbar fusion surgery might contribute to improvement of surgical outcome.
Topics: Humans; Male; Spinal Stenosis; Female; Lumbar Vertebrae; Aged; Psoas Muscles; Middle Aged; Follow-Up Studies; Spinal Fusion; Pedicle Screws; Magnetic Resonance Imaging; Sacrum; Retrospective Studies; Risk Factors; Aged, 80 and over; Preoperative Period
PubMed: 38807200
DOI: 10.1186/s12891-024-07298-0 -
Journal of Orthopaedic Surgery and... May 2024The optimal treatment modality for upper lumbar disc herniation remains unclear. Herein, we compared the clinical efficacy and application value of minimally invasive... (Comparative Study)
Comparative Study
BACKGROUND
The optimal treatment modality for upper lumbar disc herniation remains unclear. Herein, we compared the clinical efficacy and application value of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and transforaminal lumbar interbody fusion (TLIF) for upper lumbar disc herniation. We aimed to provide new evidence to guide surgical decisions for treating this condition.
METHODS
We retrospectively analyzed the clinical data of 81 patients with upper lumbar disc herniation admitted between January 2017 and July 2018, including 41 and 40 patients who underwent MIS-TLIF and TLIF, respectively. Demographic characteristics, preoperative functional scores, perioperative indicators, and postoperative complications were compared. We performed consecutive comparisons of visual analog scale (VAS) scores of the lumbar and leg regions, Oswestry disability index (ODI), Japanese Orthopaedic Association scores (JOA), and MacNab scores at the final follow-up, to assess clinical outcomes 5 years postoperatively.
RESULTS
VAS scores of the back and legs were significantly lower in the MIS-TLIF than the TLIF group at 3 months and 1 year postoperatively (P < 0.05). Intraoperative bleeding and postoperative hospitalization time were significantly lower, and the time to return to work/normal life was shorter in the MIS-TLIF than in the TLIF group (P < 0.05). The differences in JOA scores and ODI scores between the two groups at 3 months, 1 year, and 3 years postoperatively were statistically significant (P < 0.05).
CONCLUSION
The early clinical efficacy of MIS-TLIF was superior to that of TLIF, but no differences were found in mid-term clinical efficacy. Further, MIS-TLIF has the advantages of fewer medical injuries, shorter hospitalization times, and faster postoperative functional recovery.
Topics: Humans; Intervertebral Disc Displacement; Spinal Fusion; Male; Female; Lumbar Vertebrae; Middle Aged; Retrospective Studies; Treatment Outcome; Adult; Minimally Invasive Surgical Procedures; Postoperative Complications; Follow-Up Studies
PubMed: 38807137
DOI: 10.1186/s13018-024-04806-9 -
PeerJ 2024Surgical intervention is a common option for the treatment of wrist joint arthritis and traumatic wrist injury. Whether this surgery is arthrodesis or a motion...
Surgical intervention is a common option for the treatment of wrist joint arthritis and traumatic wrist injury. Whether this surgery is arthrodesis or a motion preserving procedure such as arthroplasty, wrist joint biomechanics are inevitably altered. To evaluate effects of surgery on parameters such as range of motion, efficiency and carpal kinematics, repeatable and controlled motion of cadaveric specimens is required. This study describes the development of a device that enables cadaveric wrist motion to be simulated before and after motion preserving surgery in a highly controlled manner. The simulator achieves joint motion through the application of predetermined displacements to the five major tendons of the wrist, and records tendon forces. A pilot experiment using six wrists aimed to evaluate its accuracy and reproducibility. Biplanar X-ray videoradiography (BPVR) and X-Ray Reconstruction of Moving Morphology (XROMM) were used to measure overall wrist angles before and after total wrist arthroplasty. The simulator was able to produce flexion, extension, radioulnar deviation, dart thrower's motion and circumduction within previously reported functional ranges of motion. Pre- and post-surgical wrist angles did not significantly differ. Intra-specimen motion trials were repeatable; root mean square errors between individual trials and average wrist angle and tendon force profiles were below 1° and 2 N respectively. Inter-specimen variation was higher, likely due to anatomical variation and lack of wrist position feedback. In conclusion, combining repeatable intra-specimen cadaveric motion simulation with BPVR and XROMM can be used to determine potential effects of motion preserving surgeries on wrist range of motion and biomechanics.
Topics: Humans; Wrist Joint; Cadaver; Range of Motion, Articular; Biomechanical Phenomena; Radiography; Male; Aged; Reproducibility of Results; Tendons; Female
PubMed: 38803578
DOI: 10.7717/peerj.17179 -
Archives of Orthopaedic and Trauma... Jun 2024Open book injuries are challenging injuries that oftentimes require surgical treatment. Currently, treatment is performed with symphyseal plating requiring extensive...
INTRODUCTION
Open book injuries are challenging injuries that oftentimes require surgical treatment. Currently, treatment is performed with symphyseal plating requiring extensive surgery and entirely limiting physiological movement of the symphyseal joint, frequently resulting in implant failure. Therefore, we investigated the biomechanical properties of a minimally invasive tape suture construct (modified SpeedBridge™) as an alternative stabilization technique for the treatment of open book injuries in human cadaver pelvic rings.
MATERIALS AND METHODS
The symphysis of 9 human cadaver pelvises was dissected and dilated to 3 cm creating an open book injury. Next, the two osteosynthesis methods (plating, modified SpeedBridge™) were applied. All specimens then underwent cyclic horizontal and vertical loading, simulating biomechanical forces while sitting, standing and walking. For statistical analysis, 3D dislocation (mm) was calculated.
RESULTS
Total displacement (mm) of the pubic symphysis displayed the following means and standard deviations: native group 1.34 ± 0.62 mm, open book group 3.01 ± 1.26 mm, tape group 1.94 ± 0.59 mm and plate group 1.37 ± 0.41 mm. Comparison between native and open book (p = 0.029), open book and plate (p = 0.004), open book and tape (p = 0.031), as well as tape and plate group (p = 0.002) showed significant differences. No significant differences were found when comparing the native and tape (p = 0.059), as well as the native and plate (p = 0.999) group.
CONCLUSION
While both osteosynthesis techniques sufficiently stabilized the injury, symphyseal plating displayed the highest rigidity. The modified SpeedBridge™ as a tape suture construct provided statistically sufficient biomechanical stability while maintaining symphyseal micro mobility, consequently allowing ligamental healing of the injured joint without iatrogenic arthrodesis.
Topics: Humans; Pubic Symphysis; Cadaver; Biomechanical Phenomena; Fracture Fixation, Internal; Male; Bone Plates; Female; Fractures, Bone
PubMed: 38801533
DOI: 10.1007/s00402-024-05390-7 -
Cureus Apr 2024Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) represent clinical entities identified by a pattern of predictable degenerative... (Review)
Review
Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) represent clinical entities identified by a pattern of predictable degenerative changes. They are the most common causes of wrist arthritis. Both entities can remain asymptomatic for many years and may go undiagnosed. Diagnosis is usually confirmed through clinical examination, which reveals progressive wrist pain and instability. Radiographically, degenerative changes in the radiocarpal and midcarpal joints are present, as well as nonunion of the scaphoid fracture in SNAC. The management differs according to the stage. Particularly in this review article, we reviewed the treatment options for stage II SLAC and SNAC wrist. In addition to the well-described surgical techniques such as proximal row carpectomy and four-corner fusion, alternatives such as capitolunate arthrodesis, three-corner fusion, and soft tissue procedures like capsulodesis and tenodesis are available. Proximal row carpectomy and partial arthrodeses yield comparable results. Soft tissue procedures are viable alternatives and are preferred in younger patients to avoid early salvage operations.
PubMed: 38800268
DOI: 10.7759/cureus.59014 -
Plastic and Reconstructive Surgery.... May 2024Soft tissue reconstruction using flaps in managing mangled injuries is occasionally insufficient due to large defects and low flap viability. Conversely, delaying the...
Soft tissue reconstruction using flaps in managing mangled injuries is occasionally insufficient due to large defects and low flap viability. Conversely, delaying the closure of the defect can elevate the risk of infection. Adjuvant therapy becomes essential in the management of mangled injuries. We aim to present the use of low-cost vacuum-assisted closure (VAC) as an adjuvant therapy for mangled injuries. We reported the case of a 20-year-old man who sustained a mangled injury to his left forearm in a traffic accident 4 hours before admission. The mangled extremity severity score was 9; however, the patient declined amputation. Although the initial reconstruction was done, the flap could only cover vital structures. VAC was utilized to address the uncovered portion of the defect, to promote optimal granulation and prevent infection. The reconstruction proceeded with a skin graft and wrist arthrodesis. At 1-year follow-up, viable tissue was obtained but contracture occurred at the metacarpophalangeal and proximal interphalangeal joints. We intend to perform functional reconstruction at a later stage. Although the benefits of VAC in wound management are well established, reports regarding its advantages in mangled injury management remain relatively scarce. The high cost of VAC is a limiting factor, particularly in developing countries. This prompts the need for an affordable VAC innovation with comparable efficiency to the commercial model. Reverse Aqua Pump VAC, our innovative low-cost VAC, shows satisfactory outcomes in managing patients with mangled injuries with mangled extremity severity score indicating amputation.
PubMed: 38798936
DOI: 10.1097/GOX.0000000000005826 -
Medicina (Kaunas, Lithuania) May 2024Klippel-Feil syndrome (KFS) is characterized by the congenital fusion of the cervical vertebrae and is sometimes accompanied by anomalies in the craniocervical junction....
Klippel-Feil syndrome (KFS) is characterized by the congenital fusion of the cervical vertebrae and is sometimes accompanied by anomalies in the craniocervical junction. In basilar invagination (BI), which is a dislocation of the dens in an upper direction, compression of the brainstem and cervical cord results in neurological defects and surgery is required. A 16-year-old boy diagnosed with KFS and severe BI presented with spastic tetraplegia, opisthotonus and dyspnea. CT scans showed basilar impression, occipitalization of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Posterior occipitocervical reduction and fusion along with decompression were performed. Paralysis gradually improved postoperatively over 3 weeks. However, severe spasticity and opisthotonus persisted and intrathecal baclofen (ITB) therapy was initiated. Following this, opisthotonus disappeared and spasticity of the extremities improved. Rehabilitation therapy continued by controlling the dose of ITB. Five years after the surgery, self-propelled wheelchair driving was achieved and activities of daily life improved. The treatment strategy for patients with BI and congenital anomalies remains controversial. Posterior reduction and internal fixation using instrumentation were effective techniques in this case. Spasticity control achieved through a combination of surgery and ITB treatment enabled the amelioration of therapeutic efficacy of rehabilitation and the improvement of ADL.
Topics: Humans; Baclofen; Male; Klippel-Feil Syndrome; Adolescent; Cervical Vertebrae; Spinal Fusion; Injections, Spinal; Muscle Relaxants, Central; Occipital Bone; Treatment Outcome; Decompression, Surgical
PubMed: 38792938
DOI: 10.3390/medicina60050755