Laminoplasty in Motion: Evolving Techniques and Complications.

Cervical laminoplasty is an increasingly popular surgical option for the treatment of cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Over the past few decades, there have been substantial developments in both surgical technique and hardware options. As the field of cervical surgery rapidly evolves, there is a timely need to reassess the evolving complications associated with newer techniques. This review aims to synthesize the available literature on cervical laminoplasty and associated mechanical complications pertaining to different laminoplasty hinge fixation options.

Does the Bone Mineral Density of the Lumbar Spine Correlate With Dual-Energy X-ray Absorptiometry T Score? A Cadaveric-Based Analysis of Computed Tomography Densitometry.

BACKGROUND: Pedicle screw loosening is a complication of spinal instrumentation in osteoporotic patients. Dual-energy x-ray absorptiometry scans are not able to detect variations in bone mineral density (BMD) within specific regions of vertebrae. The purpose of this study was to investigate whether spine T scores correlate with cortical and cancellous BMD of pedicles and other 6 anatomical regions of lumbar spine. METHODS: Eleven cadaveric spines with a mean age of 73 years were digitally isolated by applying filters for cortical and cancellous bone on computed tomography images. Eleven L5 vertebrae were separated into 7 anatomical regions of interest using 3-dimensional software modeling. Hounsfield units (HU) were determined for each region and converted to cortical and cancellous BMD with calibration phantoms of known BMD. Correlations between T scores and HU values were calculated using Pearson correlation coefficient. RESULTS: Mean vertebral T score was 0.15. Cortical BMD of pedicles was strongly correlated with T score (R 2 = 0.74). There was moderate correlation between T score and cortical BMD of lamina, inferior articular process (IAP), superior articular process (SAP), spinous process, and vertebral body. There was weak correlation between T score and cortical BMD of transverse process (R 2 = 0.16). Cancellous BMD of vertebral body was strongly correlated with T score (R 2 = 0.82). There was moderate correlation between T score and cancellous BMD of pedicles, spinous process, and transverse process. There was weak correlation between T scores and cancellous BMD of lamina, IAP, and SAP. CONCLUSIONS: There is a strong correlation between T scores and cortical BMD of lumbar pedicle. There is strong correlation between T scores and cancellous BMD of vertebral body. Cortical and cancellous BMD of transverse process and lamina were weakly correlated with T score and less affected by osteoporosis. CLINICAL RELEVANCE: Patients with osteoporosis may especially benefit from the development of extrapedicular fusion strategies due to the relatively higher bone density of these fixation sites.

Pyogenic spinal infections warrant a total spine MRI.

Study design: retrospective case series. Objective: the presenting clinical symptoms of spinal infections are often nonspecific and a delay in diagnosis can lead to adverse patient outcomes. The morbidity and mortality of patients with multifocal spinal infections is significantly higher compared to unifocal infections. The purpose of the current study was to analyse the risk factors for multifocal spinal infections. Methods: we conducted a retrospective review of all pyogenic non-tuberculous spinal infections treated surgically at a single tertiary care medical center from 2006-2020. The medical records, imaging studies, and laboratory data of 43 patients during this time period were reviewed and analysed after receiving Institutional Review Board approval. Univariate and multivariate analyses were performed to identify factors associated with a multifocal spinal infection. Results: 15 patients (35 %) had multifocal infections. In univariate analysis, there was a significant association with chronic kidney disease ( p = 0.040 ), gender ( p = 0.003 ), a white blood cell count ( p = 0.011 ), and cervical ( p < 0.001 ) or thoracic ( p < 0 .001) involvement. In multivariate analysis, both cervical and thoracic involvement remained statistically significant ( p = 0.001 and p < 0.001 , respectively). Conclusions: patients with infections in the thoracic or cervical region are more likely to have a multifocal infection. Multifocal pyogenic spinal infections remain a common entity and a total spine MRI should be performed to aid in prompt diagnosis.

C1-C2 Facet Joint Penetration by C2 Pedicle Screws: Influence of Local Anatomy, Bone Mineral Density, and Screw Length.

BACKGROUND: A challenge of C2 pedicle screw placement is to avoid penetration into the C1-C2 facet joint, as this may alter normal biomechanics and accelerate joint degeneration. Our objective was to clarify how local anatomy and surgical technique may relate to C2 pedicle screw penetration into the C1-C2 facet joint. METHODS: C2 pedicle screws were inserted using a fluoroscopically assisted freehand technique. Independent fellowship-trained spine surgeons blindly reviewed intraoperative fluoroscopic and postoperative computed tomography (CT) images for evidence of facet joint penetration (FJP). C2 pedicle morphometry, the sagittal angle of the facet joint, axial and sagittal pedicle screw angles, and screw length were measured on the relevant CT images. RESULTS: A total of 34 patients fulfilled the study criteria, and a total of 68 C2 pedicle screws were placed. Eight screws (16%) penetrated the C1-C2 facet joint. The mean sagittal angle of the C1-C2 facet joint was significantly lower in the FJP group compared with the non-FJP group. The mean sagittal angle of the screws was significantly higher in the FJP group compared with the non-FJP group. The mean screw length was significantly greater for screws causing FJP compared with the non-FJP group. The mean axial screw angle was significantly lower in the FJP group compared with the non-FJP group. Pedicle width, length, height, and transverse angle were not significantly associated with FJP. Independent reviewers were able to identify FJP on intraoperative fluoroscopic imaging in 2 out of 8 cases. CONCLUSION: Lower sagittal angle of the facet joint, higher sagittal angle of the pedicle screw, and screw length >24 mm are associated with higher risk of C1-C2 FJP. When placing C2 pedicle screws under these conditions, caution should be taken to avoid FJP. CLINICAL RELEVANCE: Several anatomical and technical factors may increase the risk of C1-C2 FJP during placement of C2 pedicle screws using a fluoroscopically assisted freehand technique, underscoring the importance of preoperative planning and limiting screw length.

Fusion Mass Screws in Revision Spinal Deformity Surgery: A Simple and Safe Alternative Fixation.

BACKGROUND: Revision spinal deformity surgery has a high rate of complications. Fixation may be challenging due to altered anatomy. Screws through a fusion mass are an alternative to pedicle screw fixation. OBJECTIVE: The purpose of this retrospective study was to further elucidate the safety and efficacy of fusion mass screws (FMSs) in revision spinal deformity surgery. DESIGN: Retrospective case series. METHODS: Fifteen freehand FMSs were placed in 6 patients with adult spinal deformity between 2016 and 2018 by the senior author. FMSs were combined with pedicle screws, at times at the same level. FMSs were used to save distal levels from fusion, assist in closing a 3-column osteotomy and provide additional fixation in cases of severe instability. Computed tomography (CT) was used to assess bone mineral density (BMD) and thickness of each fusion mass preoperatively along with accuracy of FMS placement postoperatively. RESULTS: The mean BMD of the fusion mass was 397 Hounsfield units (HU; range: 156-628 HU). The mean AP thickness of the fusion mass was 15.5 ± 4.8 mm (range: 8.6-24.4 mm). The mean FMS length was 35.3 ± 5.5 mm (range: 25-40 mm). There was no evidence of FMS loosening, breakage, or pseudarthrosis at latest follow-up (mean: 2.2 years, range: 1.4-3.1 years). No neurologic deficits were observed. 1/15 screws had a low-grade breach into the canal (<2 mm). No patients required revision surgery. CONCLUSION: FMSs may be used to augment fixation in revision spinal deformity cases when pedicle screw placement may be challenging. FMSs may also provide an additional anchor at levels with pedicular fixation.

Does Time to Surgery for Distal Radius Fractures Impact Clinical and Radiographic Outcomes? A Systematic Literature Review.

Distal radius fractures are one of the most common upper extremity fractures across all age groups. Although the American Academy of Orthopaedic Surgery (AAOS) Clinical Practice Guidelines have defined recommendations for the treatment of distal radius fractures, the optimal time to surgery was not included. There remains relatively little guidance or consensus regarding the optimal timing of surgical intervention for distal radius fractures and the impact of time to surgery on outcomes. As such, the purpose of this investigation is to systematically review clinical and radiographic outcomes associated with time to surgical management of distal radius fractures.

Alternatives to Traditional Pedicle Screws for Posterior Fixation of the Degenerative Lumbar Spine.

BACKGROUND: Traditional pedicle screws are currently the gold standard to achieve stable 3-column fixation of the degenerative lumbar spine. However, there are cases in which pedicle screw fixation may not be ideal. Due to their starting point lateral to the pars interarticularis, pedicle screws require a relatively wide dissection along with a medialized trajectory directed toward the centrally located neural elements and prevertebral vasculature. In addition, low bone mineral density remains a major risk factor for pedicle screw loosening, pullout, and pseudarthrosis. The purpose of this article is to review the indications, advantages, disadvantages, and complications associated with posterior fixation techniques of the degenerative lumbar spine beyond the traditional pedicle screws. METHODS: Comprehensive literature searches of the PubMed, Scopus, and Web of Science databases were performed for 5 methods of posterior spinal fixation, including (1) cortical bone trajectory (CBT) screws, (2) transfacet screws, (3) translaminar screws, (4) spinous process plates, and (5) fusion mass screws and hooks. Articles that had been published between January 1, 1990, and January 1, 2020, were considered. Non-English-language articles and studies involving fixation of the cervical or thoracic spine were excluded from our review. RESULTS: After reviewing over 1,700 articles pertaining to CBT and non-pedicular fixation techniques, a total of 284 articles met our inclusion criteria. CBT and transfacet screws require less-extensive exposure and paraspinal muscle dissection compared with traditional pedicle screws and may therefore reduce blood loss, postoperative pain, and length of hospital stay. In addition, several methods of non-pedicular fixation such as translaminar and fusion mass screws have trajectories that are directed away from or posterior to the spinal canal, potentially decreasing the risk of neurologic injury. CBT, transfacet, and fusion mass screws can also be used as salvage techniques when traditional pedicle screw constructs fail. CONCLUSIONS: CBT and non-pedicular fixation may be preferred in certain lumbar degenerative cases, particularly among patients with osteoporosis. Limitations of non-pedicular techniques include their reliance on intact posterior elements and the lack of 3-column fixation of the spine. As a result, transfacet and translaminar screws are infrequently used as the primary method of fixation. CBT, transfacet, and translaminar screws are effective in augmenting interbody fixation and have been shown to significantly improve fusion rates and clinical outcomes compared with stand-alone anterior lumbar interbody fusion. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Whole-Spine Magnetic Resonance Imaging: A Review of Suggested Indications.

¼: The spinal column has a propensity for lesions to manifest in a multifocal manner, and identification of the lesions can be difficult. ¼: When used to image the spine, magnetic resonance imaging (MRI) most accurately identifies the presence and location of lesions, guiding the treatment plan and preventing potentially devastating complications that are known to be associated with unidentified lesions. ¼: Certain conditions clearly warrant evaluation with whole-spine MRI, whereas the use of whole-spine MRI with other conditions is more controversial. ¼: We suggest whole-spine MRI when evaluating and treating any spinal infection, lumbar stenosis with upper motor neuron signs, ankylosing disorders of the spine with concern for fracture, congenital scoliosis undergoing surgical correction, and metastatic spinal tumors. ¼: Use of whole-spine MRI in patients with idiopathic scoliosis and acute spinal trauma remains controversial.

A partial articular-sided supraspinatus tear caused by the biceps tendon: A novel etiology of internal impingement.

Impingement of the LHB can directly lead to articular-sided supraspinatus tears. When pain persists despite arthroscopic debridement, we recommend taking the arm out of traction intraoperatively and placing it in the 90-90 position.

Pedicle Screws Challenged: Lumbar Cortical Density and Thickness Are Greater in the Posterior Elements Than in the Pedicles.

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: To measure the total bone mineral density (BMD), cortical volume, and cortical thickness in seven different anatomical regions of the lumbar spine. METHODS: Using computed tomography (CT) images, 3 cadaveric spines were digitally isolated by applying filters for cortical and cancellous bone. Each spine model was separated into 5 lumbar vertebrae, followed by segmentation of each vertebra into 7 anatomical regions of interest using 3-dimensional software modeling. The average Hounsfield units (HU) was determined for each region and converted to BMD with calibration phantoms of known BMD. These BMD measurements were further analyzed by the total volume, cortical volume, and cancellous volume. The cortical thickness was also measured. A similar analysis was performed by vertebral segment. St Mary's Medical Center's Institutional Review Board approved this study. No external funding was received for this work. RESULTS: The lamina and inferior articular process contained the highest total BMD, thickest cortical shell, and largest percent volumes of cortical bone. The vertebral body demonstrated the lowest BMD. The BMDs of the L4 and L5 segments were lower; however, there were no statistically significant differences in BMD between the L1-L5 vertebral segments. CONCLUSION: Extrapedicular regions of the lumbar vertebrae, including the lamina and inferior articular process, contain denser bone than the pedicles. Since screw pullout strength relies greatly on bone density, the lamina and inferior articular processes may offer stronger fixation of the lumbar spine.

Non-Pedicular Fixation Techniques for the Treatment of Spinal Deformity: A Systematic Review.

BACKGROUND: In recent years, the use of pedicle screws has become the gold standard for achieving stable, 3-column fixation of the spine. However, pedicle screw placement may not always be ideal, such as in adolescent idiopathic scoliosis, because of pedicle morphology. An understanding of the alternatives to pedicle screw fixation is therefore important in the treatment of patients with spinal deformity. The purpose of this article is to review the indications, advantages, disadvantages, and complications associated with non-pedicular fixation techniques of the thoracolumbar spine. METHODS: Comprehensive literature searches of PubMed, Scopus, and Web of Science databases were performed for 10 methods of non-pedicular fixation. Articles published between January 1, 1990, and June 1, 2019, were considered. Non-English-language articles and studies involving fixation of the cervical spine were excluded from our review. RESULTS: After reviewing >1,600 titles and abstracts pertaining to non-pedicular fixation, a total of 213 articles met our inclusion criteria. Non-pedicular fixation may be preferred in certain cases of spinal deformity and may provide stronger fixation in osteoporotic bone. The use of non-pedicular fixation techniques is often limited by the inability to place multilevel constructs on intact posterior elements. Additionally, some methods of non-pedicular fixation, such as spinous process tethering, primarily have utility for the end of constructs to minimize junctional problems. CONCLUSIONS: Pedicle screws remain the anchor of choice in spinal deformity surgery because of their ability to engage all 3 columns of the spine and provide safe correction in all 3 planes. Nevertheless, non-pedicular fixation may be useful in cases in which pedicle screw placement is extremely difficult. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Motion Preservation at All Costs? Multilevel Hinge Nonunion, Plate Breakage, and Intradural Plate Migration After Cervical Laminoplasty: A Case Report and Literature Review.

BACKGROUND: Cervical laminoplasty is a motion-preserving procedure that addresses spinal cord compression and avoids postlaminectomy kyphosis associated with cervical laminectomy. The most common complications include C5 nerve palsy, axial neck pain, hinge nonunion, and premature closure. Plating is a relatively newer method of laminoplasty fixation that may provide greater stabilization postoperatively and reduce the risk of laminoplasty closure compared with less rigid (e.g., suture) fixation techniques. Although prior studies have reported low rates of laminar/lateral mass screw back out, plate breakage and migration have not been previously described in the literature. The purpose of this paper is to present a case of multilevel hinge nonunion, plate breakage, and plate fragment migration. Although rare, plate failure may result in a dural tear and spinal cord injury/compression. CASE DESCRIPTION: In this case, a 61-year-old man with a history of cervical spondylotic myelopathy treated with C3-7 laminoplasty 7 years prior presented to our hospital with severe headaches and electrical-type pain through the left upper and lower extremities. Imaging studies revealed several broken laminoplasty plates and intradural migration of a fragment of the C7 plate. CONCLUSIONS: We provide recommendations for preventing hinge nonunion because resultant micromotion likely contributed to the plate breakages observed in this patient.

Anterior Lumbar Interbody Fusion May Provide Superior Decompression of the Foraminal Space Compared with Direct Foraminotomy: Biomechanical Cadaveric Study.

OBJECTIVE: The objective of this cadaveric biomechanical study was to compare the area of the foraminal space during motion in the intact condition, after direct decompression via foraminotomy, and after indirect decompression via anterior lumbar interbody spacer insertion. METHODS: Eight (8) L5-S1 cadaver specimens were used for testing. Each specimen was tested in the intact state, after posterior foraminotomy, and after standalone anterior lumbar interbody fusion (ALIF). Each specimen was 3-dimensional imaged under neutral loading, flexion, and extension. The 3-dimensional images were analyzed for changes in the foraminal area under each loading scenario. A repeat-measures design was used. Outcome measures from testing included the frequency in which an increase in cross-sectional area was observed, as well as the percent increase of the foraminal area for each surgical group and loading direction. RESULTS: Direct foraminotomy and ALIF maintained the foraminal space during initial distraction under no loading with areas 99.7% and 96.5% of the native foraminal area, respectively (P = 0.955 and P = 0.455). Direct foraminotomy increased the foraminal area significantly during flexion to 112.2% of the area before motion (P = 0.008) while ALIF did not. Direct foraminotomy significantly decreased the foraminal area during extension to 89.2% of the area before motion (P = 0.006). ALIF, however, maintained its initial distraction during extension with 98.2% of the area before motion (P = 0.808). CONCLUSIONS: ALIF maintains the foraminal area in extension while direct posterior foraminotomy does not.

A 360° Labral Repair Using Two Portals and a Percutaneous Cannula.

Pan-labral tears are relatively uncommon, but they present significant challenges to arthroscopists. The difficulty lies in the need to access the glenoid rim circumferentially for proper anchor placement. Traditionally, this requires that multiple portals and percutaneous access be established as needed. Additionally, proper preoperative planning is needed to accurately reduce the labrum. In this Technical Note, we demonstrate a technique that accomplishes circumferential access and a well-planned approach with 2 portals and a percutaneous cannula.

High Prevalence of Multifocal Spine Infections Involving the Cervical and Thoracic Regions: A Case for Imaging the Entire Spine.

OBJECTIVE: Pyogenic spinal infections account for 2%-4% of orthopaedic infections. They are often difficult to diagnose, resulting in a delay in diagnosis. Risk factors for orthopaedic and spinal infection are well-documented in the literature, yet there is a paucity of studies examining risk factors specifically for multifocal spinal infections. The objective of this study was to identify predictors of multifocal spinal infections in comparison to unifocal spinal infections. METHODS: The medical records, imaging studies, and bacteriology data of 20 patients treated surgically for pyogenic spinal infection over 6 years at a tertiary referral center were reviewed and analyzed after receiving Institutional Review Board approval. Univariate and multivariate analyses were performed to identify factors associated with a multifocal spinal infection. RESULTS: Seven patients (35%) had multifocal infections. Three were bifocal, and 4 were trifocal. Patients with surgically treated cervical or thoracic spinal infections had a high rate of concomitant multifocal spinal infections (71% and 83%, respectively). Other potential predictors (e.g., patient age, body mass index, magnetic resonance image findings, etc.) did not reach statistical significance. Each of the multifocal infections involved the lumbar spine. CONCLUSION: In this study, the spinal region was the only statistically significant risk factor for multifocal infection. Patients who are diagnosed with a spinal infection that requires operative treatment should have their entire spine evaluated with magnetic resonance imaging to detect multifocal involvement promptly.

Arthroscopic Double-Pulley Remplissage Using a 2-Portal Technique for Hill-Sachs Lesions in Recurrent Anterior Shoulder Instability.

Hill-Sachs lesions of the humeral head are associated with recurrent anterior shoulder instability. Arthroscopic double-pulley remplissage has emerged as the leading alternative to the open Latarjet procedure to address recurrent shoulder instability with comparable recurrence rates and favorable complication rates. This Technical Note describes our adaptation of the double-pulley remplissage technique by using 2 portals, with the anterior portal used as the viewing portal and suture passage through the posterior portal. This technique eliminates the need for a lateral percutaneous portal, consequently minimizing operative time and postoperative morbidity. Furthermore, using the anterior portal as the viewing portal allows for direct visualization of the reduction of the infraspinatus into the Hill-Sachs defect. The drawback of this technique is that there is no view of the subacromial space during knot tying.

Double-Bundle Medial Patellofemoral Ligament Reconstruction With Allograft.

Medial patellofemoral ligament (MPFL) reconstruction is the treatment of choice for recurrent patellofemoral instability. Although attention to MPFL reconstruction in the orthopaedic literature has increased dramatically in recent years, there is no clear consensus on surgical technique, graft option, or method of fixation. Nevertheless, most studies have shown improved pain scores and low rates of recurrent dislocation in patients after surgery. Despite the early success of MPFL reconstruction, complications may occur more frequently than previously appreciated and include patellar fracture, postoperative instability, and loss of flexion. This article describes our technique for double-bundle MPFL reconstruction with an allograft while highlighting certain aspects of the procedure that are critical for achieving favorable outcomes. The main advantages of the technique include strong patellar fixation with suture anchors and anatomic graft placement at the origin and insertion of the native MPFL. In our experience, this method of reconstruction has been safe, reproducible, and effective in the treatment of patients with patellar instability.

Arthroscopic-Assisted Osteochondral Allograft Transplantation for Posterolateral Lesions of the Talus Without Fibular Osteotomy.

Osteochondral lesions of the talus are chondral defects often caused by acute trauma to the ankle such as sprains and fractures. If operative treatment is necessary, microfracture, cartilage replacement, and autologous chondrocyte implantation can be used. We describe a single-step osteochondral allograft transfer to access the posterolateral talar dome that avoids the need for a fibular osteotomy and therefore eliminates morbidity while reducing operative time.

Osteochondral Allograft Transplantation of the Medial Femoral Condyle With Orthobiologic Augmentation and Graft-Recipient Microfracture Preparation.

Osteochondritis dissecans (OCD) has been recognized for over 100 years yet still poses treatment challenges owing to both the avascular nature of articular cartilage and the inability to generate hyaline cartilage. The knee is most commonly involved, and without repair, patients have chronic knee pain, loose bodies, and early-onset osteoarthritis. There are a number of surgical techniques for repairing OCD, some of which are still being refined. Currently, common procedures used to treat OCD lesions include microfracture, autologous chondrocyte implantation, osteochondral autograft transplantation, and osteochondral allograft transplantation. In this Technical Note, we describe osteochondral allograft transplantation with the addition of platelet-rich plasma and graft-recipient microfracture. We believe the micropores augment the osteoconductive and osteoinductive properties of the allograft and aid in the incorporation of the allograft plug by improving angiogenesis, enhancing clot formation in the allograft, and providing a homogeneous environment for remodeling.