The Hip-Spine Challenge.

➤: The proper diagnosis and treatment of patients with concurrent hip and spine pathological processes can be challenging because of the substantial overlap in symptomatology. ➤: There is no consensus on which pathological condition should be addressed first. ➤: Factors such as advanced spinal degeneration, deformity, and prior fusion alter the biomechanics of the spinopelvic unit. Attention should be paid to recognizing these issues during the work-up for a total hip arthroplasty as they can result in an increased risk of dislocation. ➤: In patients with concurrent spine and hip degeneration, the surgeon must pay close attention to appropriate implant positioning and have consideration for implants with enhanced stability to minimize the risk of dislocation. ➤: A proper understanding of sagittal balance and restoration of this balance is integral to improving patient outcomes following spinal surgery. ➤: The advent of new imaging modalities, increased awareness of spinopelvic mobility, as well as a better understanding of sagittal alignment will hopefully improve our treatment of patients with hip-spine syndrome.

The current state of navigation in robotic spine surgery.

The advent and widespread adoption of pedicle screw instrumentation prompted the need for image guidance in spine surgery to improve accuracy and safety. Although the conventional method, fluoroscopy, is readily available and inexpensive, concerns regarding radiation exposure and the drive to provide better visual guidance spurred the development of computer-assisted navigation. Contemporaneously, a non-navigated robotic guidance platform was also introduced as a competing modality for pedicle screw placement. Although the robot could provide high precision trajectory guidance by restricting four of the six degrees of freedom (DOF), the lack of real-time depth control and high capital acquisition cost diminished its popularity, while computer-assisted navigation platforms became increasingly sophisticated and accepted. The recent integration of real-time 3D navigation with robotic platforms has resulted in a resurgence of interest in robotics in spine surgery with the recent introduction of numerous navigated robotic platforms. The currently available navigated robotic spine surgery platforms include the ROSA Spine Robot (Zimmer Biomet Robotics formerly Medtech SA, Montpellier, France), ExcelsiusGPS® (Globus Medical, Inc., Audubon, PA, USA), Mazor X spine robot (Medtronic Navigation Louisville, CO; Medtronic Spine, Memphis, TN; formerly Mazor Robotics, Caesarea, Israel) and TiRobot (TINAVI Medical Technologies, Beijing, China). Here we provide an overview of these navigated spine robotic platforms, existing applications, and potential future avenues of implementation.

Preoperative planning for intraoperative navigation guidance.

Intraoperative navigation for spinal procedures has continued to gain popularity. Numerous platforms are currently on the market and offer a spectrum of features. Preoperative considerations when utilizing this technology begin with understanding the fundamental concepts and methods of navigation. Several key factors including patient positioning, reference array placement, and sequence of instrumentation can help improve intraoperative navigation workflow when planned appropriately. The authors review current literature to help guide surgeon decision making when utilizing navigation. Additionally, tips and techniques for use of navigation are detailed to help avoid common surgeon pitfalls. In general, navigation platforms are classified based on image acquisition and degree of surgeon motion restriction during instrumentation. Imageless platforms often require preoperative images to be uploaded into the navigation system. Image-based systems rely on intraoperative imaging to ensure accuracy of its referencing software. The system then creates a three-dimensional model that allows for visualization of the navigated instrument within the surgical field. Active and passive navigation describe the degree of surgeon free-motion restriction when utilizing navigated instruments. Active navigation platforms, such as most robotic systems, prevent the deviation of the surgeon's instrument from a predetermined trajectory. Passive navigation does not restrict surgeon motion and the projected trajectory of the instrumented can be displayed on a three-dimensional model.

Radiographic Evaluation of Cervical Disk Replacement: The Impact of Preoperative Arthrosis and Implant Positioning on Patient-report Outcomes.

STUDY DESIGN: This was a retrospective review. OBJECTIVE: Provide a validated method of radiographic evaluation of cervical disk replacement (CDR) patients linked to outcomes. SUMMARY OF BACKGROUND DATA: Preoperative radiographic criteria for CDRs and the impact of intraoperative positioning remain without formalized guidelines. The association between preexisting degenerative changes, optimal implant positioning, and patient-reported outcome measures (PROMs) are not well understood. Our study establishes a systematic radiographic evaluation of preoperative spondylosis, implant placement, and associated clinical outcomes. METHODS: Preoperative radiographs for CDR patients were evaluated for disk height, facet arthrosis, and uncovertebral joint degeneration. Postoperative radiographs were scored based on the position of the CDR implant on anterior-posterior (AP) and lateral radiographs. PROMs including Visual Analogue Scale (VAS) arm pain, VAS neck pain, Neck Disability Index (NDI), Short Form 12 physical health (SF12-PCS) and mental health (SF12-M) were collected preoperatively, at early follow, and at late follow-up. RESULTS: A total of 115 patients were included. Preoperative disk height had the highest reliability, intraclass correlation coefficient of 0.798). Facet arthrosis had the lowest intraclass correlation coefficient at 0.563. Preoperative disk height scores showed a significant correlation with AP radiographs and implant positioning score. Patients with more advanced uncovertebral degenerative changes showed less improvement 6 months postoperatively, based on SF-12 PCS scores (R=0.446, P=0.025). Postoperative implant position on lateral radiograph showed a significant correlation with SF-12 MCS scores at follow-up beyond 6 months (R=0.385, P=0.011). Overall postoperative implant position scores demonstrated significant correlation with SF-12 PCS (R=0.350, P=0.046) scores. CONCLUSION: This study provides a systematic method of evaluation of preoperative and intraoperative radiographs that can optimize outcomes. On the basis of our study, spine surgeons performing cervical disk replacement surgery should consider: (a) the presence of preexisting uncovertebral joint degeneration can negatively impact outcomes, (b) achieving optimal implant positioning can be increasingly difficult with more severe loss of disk height, and (c) overall implant position as judged on AP and lateral fluoroscopy can impact outcomes.

Outcomes of Revision Surgery for Pseudarthrosis After Anterior Cervical Fusion: Case Series and Systematic Review.

STUDY DESIGN: Case series/systematic review. OBJECTIVES: To report on patients undergoing posterior cervical fusion for symptomatic pseudarthrosis following anterior cervical discectomy and fusion (ACDF), and to assess outcomes reporting in the literature. METHODS: Patients undergoing posterior instrumented fusion for pseudarthrosis after primary ACDF from 2013 to 2018 by a single surgeon were reviewed consecutively. Neck Disability Index (NDI) and visual analogue scale (VAS) arm/neck were recorded at preoperative, 6-month, and 1-year time points. A systematic review of the literature was performed, and outcomes reporting was recorded. RESULTS: NDI scores were 54.4 (SD 19.1), 36.6 (SD 18.1), and 41.2 (SD 19.2) at preoperative, 6-month, and 1-year time points, respectively, with improvement from preoperatively to 6 months (P = .004). VAS neck scores were 8.1 (SD 1.3), 5.0 (SD 2.9), and 5.8 (SD 2.2) at preoperative, 6-month, and 1-year time points, respectively, with improvement from preoperatively to 6 months (P = .038). VAS arm scores were 5.1 (SD 4.1), 3.5 (SD 3.2), and 3.6 (SD 2.7) at preoperative, 6-month, and 1-year time points, respectively, with improvement although these did not reach statistical significance (P = .145). The most common subjective outcomes reported in the literature were general symptoms assessments (43%), ordinal scales (43%), and VAS neck (19%) scales, with the majority of studies (67%) documenting one measure. CONCLUSIONS: Patient-reported outcomes demonstrate clinically meaningful improvement within the first 6 months after posterior fusion for pseudarthrosis. Studies demonstrate substantial variability and no standardization in outcomes reporting, limiting the ability to compare results across interventions and pathologies. Standardized reporting will enable comparisons to inform patients and physicians on the optimal approach to treat this difficult problem.

Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?

STUDY DESIGN: Retrospective case series. OBJECTIVE: Compensatory changes above a proximal junctional kyphosis (PJK) have not been defined. Understanding these mechanisms may help determine optimal level selection when performing revision for PJK. This study investigates how varying PJK location changes proximal spinal alignment. METHODS: Patients were grouped by upper instrumented vertebrae (UIV): lower thoracic (LT; T8-L1) or upper thoracic (UT; T1-7). Alignment parameters were compared. Correlation analysis was performed between PJK magnitude and global/cervical alignment. RESULTS: A total of 369 patients were included; mean age of 63 years, body mass index 28, and 81% female, LT (n = 193) versus UT (n = 176). The rate of radiographic PJK was 49%, higher in the LT group (55% vs 42%, P = .01). The UT group displayed significant differences in all cervical radiographic parameters (P < .05) between PJK versus non-PJK patients, while the LT group displayed significant differences in T1S and C2-T3 sagittal vertical axis (SVA) (CTS). In comparing UT versus LT patients, UT had more posterior global alignment (smaller TPA [T1 pelvic angle], SVA, and larger PT [pelvic tilt]) and larger anterior cervical alignment (greater cSVA [cervical SVA], T1S-CL [T1 slope-cervical lordosis] mismatch, CTS) compared to LT. Correlation analysis of PJK magnitude and location demonstrated a correlation with increases in CL, T1S, and CTS in the UT group. In the LT group, PT increased with PJK angle (r = 0.17) and no significant correlations were noted to SVA, cSVA, or T1S-CL. CONCLUSIONS: PJK location influences compensation mechanisms of the cervical and thoracic spine. LT PJK results in increased PT and CL with decreased CTS. UT PJK increases CL to counter increases in T1S with continued T1S-CL mismatch and elevated cSVA.

Congenital Unilateral Hypertrophy of the Foot Intrinsics: A Rare Case and Review of Literature.

INTRODUCTION: Congenital hypertrophy of the intrinsic muscles of the foot is a rare disorder of unknown incidence characterized by unilateral muscular hypertrophy of one or more of the intrinsic muscles. Few cases have been reported in literature, many presenting with hypertrophy of a single muscle. CASE REPORT: A 12-year-oldCaucasian female with hypertrophy of all intrinsic muscles of the right foot present since birth presented with muscle imbalance resulting in hammer toe deformities of the second and third toes with the second toe crossing over the hallux. Our treatment consisted of the correction of the toe deformities without muscle debulking or excision. CONCLUSIONS: Isolated congenital hypertrophy of muscles poses a unique challenge, particularly involving musculature of the foot. Indications for intervention include pain or functional impairment. Specific treatments should aim to address patient complaints with the understanding that debulking procedures carry the risk of abundant scar formation, neurovascular injury, and functional deficits.

Sagittal Reconstruction and Clinical Outcome Using Traditional ACDF, Versus Stand-alone ACDF Versus TDR: A Systematic Review and Quantitative Analysis.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine the difference in postoperative sagittal alignment when single level cervical radiculopathy or myelopathy is treated with an anterior cervical discectomy and fusion (ACDF) using a structural graft and plate, a stand-alone ACDF, or a total disc arthroplasty (TDR). We also wanted to determine if postoperative sagittal alignment impacted clinical outcomes in this patient population. SUMMARY OF BACKGROUND DATA: Although there are several accepted techniques for interbody reconstruction during single level anterior cervical surgery, little is known on the impact of any of them on segmental and regional sagittal alignment. METHODS: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines of the PubMed, Embase, and Cochrane databases. Only studies which contained pre and postoperative C2-7 Cobb angles as well as Neck Disability Index (NDI) scores following single level traditional ACDF with plate and cage, stand-alone ACDF, or TDR with at least 1 year follow up were included. RESULTS: There were 12 publications that fulfilled the inclusion criteria with a total of 658 patients. Cluster regression analysis showed no difference between treatment arms at each respective time-point or in the overall change in NDI from preoperative to postoperative (P = 0.88). Cluster regression analysis showed no difference between treatment arms at each respective time point or in the overall change in lordosis from pre-op to post-op (P = 0.93). CONCLUSION: This review provides evidence that while NDI scores improved across all devices, there was no significant difference in NDI improvement or C2-7 Cobb angle change between single level traditional ACDF, stand-alone ACDF, or TDR. Although TDR has not been considered a lordosis producing operation, our investigation shows it does not differ significantly in sagittal profile from other cervical fusion techniques. Moreover, we show that the NDI score improved, regardless of device implanted. LEVEL OF EVIDENCE: 1.

Correction to: The relationship of pelvic incidence to post-operative total hip arthroplasty dislocation in patients with lumbar fusion.

The original publication of this paper contain an error. The author name "Alan S. McGee Jr" is incorrect for it should have been "Alan W. McGee Jr".

The relationship of pelvic incidence to post-operative total hip arthroplasty dislocation in patients with lumbar fusion.

PURPOSE: To determine if lumbar fusion increases the risk of dislocation following total hip arthroplasty (THA) via a posterior approach and to investigate anatomic variables associated with this increased risk. METHODS: Five-year retrospective review of THAs performed through a posterior approach identifying cases of post-operative dislocation. Patients were grouped into those with or without previous lumbar spine fusion. Lumbar fusion patients were then further analyzed in terms of cup position, pelvic incidence, sacral slope, and pelvic tilt to determine if there were specific variables associated with the increased risk of dislocation. RESULTS: Five hundred nine primary THAs in 460 patients (non-simultaneous bilateral THAs in 41 patients) met inclusion criteria with a dislocation rate of 5.5%. Thirty-one patients were identified as having prior lumbar fusions. The dislocation rate was significantly higher in fusion patients (29 vs 4%; p = 0.009) yielding a relative risk (RR) of dislocation of 4.77 (p = < 0.0001). Additionally, cup anteversion was significantly different between groups (26.8 vs 21.42; p = 0.009). Dislocators in the fusion group were also at greater risk of requiring subsequent revision (RR = 3.24; p = 0.003). Subgroup analysis of fusion patients revealed that dislocators had lower pelvic incidence and sacral slope compared to non-dislocators (45.2 vs 58.6 [p = 0.0029] and 26.3 vs 35.6 [p = 0.0384] respectively). CONCLUSIONS: Patients with lumbar fusion are at increased risk for post-operative dislocations requiring revision. Together, lower pelvic incidence and decreased sacral slope are associated with increased risk of dislocation in these patients.

Radiographic Evaluation of Acetabular Fractures: Review and Update on Methodology.

Despite increased availability of modern imaging techniques, plain radiographs remain the initial step in the classification of acetabular fractures. The ability to interpret the injury configuration allows the surgeon to develop a thorough preoperative plan and to evaluate the quality of reduction and fixation intraoperatively. Proficiency in the mental conversion of a two-dimensional radiograph into a three-dimensional conceptual image is imperative. The widely used radiographic classification scheme developed by Judet and Letournel in the 1960s is both practical and simple. However, understanding the subtleties of the fracture pattern can be a challenge even for experienced surgeons. Current evaluation methods include CT and three-dimensional reconstructions in addition to plain radiographs. Our diagnostic algorithm uses three plain radiographs to classify the fracture into one of the 10 fracture patterns described by Judet and Letournel.

Degenerative Scoliosis.

PURPOSE OF REVIEW: The purpose of this review is to provide an updated review of adult degenerative scoliosis (ADS). Epidemiology, classification, pathophysiology, and natural history are discussed along with a summary of commonly used outcome measures. Operative vs non-operative outcomes and new surgical techniques are discussed. RECENT FINDINGS: The SRS-Schwab classification (2012) combines clinical and radiographic evaluation including overall global alignment. Current evidence regarding risk factors and efficacy of non-surgical modalities are discussed. Recent studies have reported surgical management to provide superior outcomes to non-operative modalities. New surgical techniques provide promising early data in regard to decreasing perioperative morbidity. ADS is a potentially debilitating condition that occurs with asymmetric spinal degeneration. This can produce global sagittal malalignment and central and foraminal stenosis and can lead to significant impairment often necessitating surgery. The surgeon must be aware of the perioperative risks in this population and implement appropriate age-specific alignment goals to achieve the best outcome for patients.

Joint Preservation Techniques in Orthopaedic Surgery.

CONTEXT: With increasing life expectancy, there is growing demand for preservation of native articular cartilage to delay joint arthroplasties, especially in younger, active patients. Damage to the hyaline cartilage of a joint has a limited intrinsic capacity to heal. This can lead to accelerated degeneration of the joint and early-onset osteoarthritis. Treatment in the past was limited, however, and surgical treatment options continue to evolve that may allow restoration of the natural biology of the articular cartilage. This article reviews the most current literature with regard to indications, techniques, and outcomes of these restorative procedures. EVIDENCE ACQUISITION: MEDLINE and PubMed searches relevant to the topic were performed for articles published between 1995 and 2016. Older articles were used for historical reference. This paper places emphasis on evidence published within the past 5 years. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 4. RESULTS: Autologous chondrocyte implantation and osteochondral allografts (OCAs) for the treatment of articular cartilage injury allow restoration of hyaline cartilage to the joint surface, which is advantageous over options such as microfracture, which heal with less favorable fibrocartilage. Studies show that these techniques are useful for larger chondral defects where there is no alternative. Additionally, meniscal transplantation can be a valuable isolated or adjunctive procedure to prolong the health of the articular surface. CONCLUSION: Newer techniques such as autologous chondrocyte implantation and OCAs may safely produce encouraging outcomes in joint preservation.

Allografts: Osteochondral, Shell, and Paste.

There is an increasing need for articular cartilage restoration procedures. Hyaline cartilage lacks intrinsic healing capacity. Persistent osteochondral defects can lead to early and rapid degenerative changes. Microfracture and autologous chondrocyte implantation provide reasonable outcomes for smaller defects without bone loss. However, these techniques have limited effectiveness for lesions greater than 4 cm2 or with significant bony involvement. Ostochondral allografts provide an option for these lesions. This article reviews osteochondral allografts for articular defects. Emerging options provide different approaches to difficult cartilage defects. We discuss current screening, procurement, and storage methods, surgical techniques, outcomes, and bacterial/viral transmission.

Orthopaedic trauma surgeons and direct anterior total hip arthroplasty: evaluation of learning curve at a level I academic institution.

BACKGROUND: Interest in the direct anterior approach for total hip arthroplasty has increased over recent years; however, the potential for substantial complications exists, especially during the surgeon's learning curve. We evaluated the change in various metrics to help identify a single surgeon's learning curve. Additionally, we examined whether the learning curve was different for primarily arthroplasty versus trauma-trained surgeons. METHODS: We reported outcomes from the first 50 total hip arthroplasties performed through a direct anterior approach by a trauma fellowship-trained orthopaedic surgeon. Intraoperative and post-operative clinical outcomes were evaluated, including length of procedure, estimated blood loss, length of hospitalization, disposition to home versus care facility, need for blood transfusion, and complications. Previous reported learning curve outcomes were analysed with a comparison between those who are primarily arthroplasty specialists versus those who include hip arthroplasty as only a portion of their practice. RESULTS: A significant difference in surgical time from 135 to 113 min was observed between the first 25 cases and the last 25. Estimated blood loss (EBL) and lateral femoral cutaneous nerve injury rates decreased but not to a significant degree. Among reported learning curves, surgical time was significantly lower among fellowship-trained arthroplasty specialists when compared with other surgeons. CONCLUSION: Our data support that surgeons who perform primarily joint arthroplasty will likely have a decreased surgical time, but similar EBL compared to those who include arthroplasty as only a portion of their practice, however, a number of confounding variables do exist, and additional investigation is warranted.

Injuries to the great toe.

PURPOSE OF REVIEW: Injuries to the great toe are common in athletes. While most are managed nonoperatively and allow return to sports activity, some great toe injuries are highly problematic and can impact function. The purpose of this review is to highlight several specific injuries and disease processes involving the hallux and to detail current recommendations and management options in order to help raise suspicion for injuries that can result in long-term dysfunction. RECENT FINDINGS: Toe injuries have been found to represent nearly 10% of injuries presenting to fracture clinics. While most injuries can be treated nonsurgically, there are a number of specific injuries that require a high index of suspicion, careful management, and in some cases, surgical intervention. Injuries detailed in this review include turf toe, traumatic bunion, and hallux and sesamoid fractures. Additional pathologies that are covered include sesamoiditis and sesamoid avascular necrosis as well as hallux rigidus. Appropriate workup and current treatment recommendations are discussed. Injuries to the hallux can result in long-term pain and disability if not properly diagnosed and treated. A high index of suspicion is required.

Allografts for Ligament Reconstruction: Where Are We Now?

The use of musculoskeletal allografts by orthopedic surgeons continues to rise. The process of procuring and sterilizing allografts is evolving with much consideration to limiting the spread of infectious diseases and preserving tissue integrity. Research involving the application of allografts, particularly for ligament repair, is quite active, necessitating an update for the practicing orthopedist. Avoiding donor site morbidities is one of the most commonly cited advantages of allografts over autografts. There is controversy amongst studies for allografts in terms of their biological incorporation and clinical outcomes compared to autografts. This article focuses on reviewing the most current literature and usage of allograft tissue for ligamentous reconstruction amongst orthopedic surgeons today. It includes an in-depth analysis of the current processing, handling, and safety standards employed today, in addition to the advantages and disadvantages of allograft use.