Heiko Koller

Background Early-term complications may not predict long-term success after adult cervical deformity (ACD) correction. Objective Evaluate whether optimal realignment results in similar rates of perioperative complications but achieves longer-term cost-utility. Study Design Retrospective cohort study. Methods ACD patients with 2-year data include...

Study Design Clinical Research. Objectives Study participants were twenty- eigth healty volunteers. Background Soft tissue complications after posterior cervicothoracic fusion surgery occur frequently. Postoperative myofascial dehiscence (PMD) can cause disability and pain. So far, it is unknown whether patients can affect PMD development through...

Background Lateral mass screw fixation is the standard for posterior cervical fusion between C3 and C6. Traditional trajectories stabilize but carry risks, including nerve root and vertebral artery injuries. Minimally invasive spine surgery (MISS) is gaining popularity, but trajectories present anatomical challenges. Research Question. This study p...

Background The association of Hounsfield units (HU) and junctional pathologies in adult cervical deformity (ACD) surgery has not been elucidated. Objective Assess if the bone mineral density of the LIV, as assessed by HUs, is prognostic for the risk of complications after ACD surgery. Study Design/Setting Retrospective cohort study. Methods HUs...

OBJECTIVE A tether pedicle screw (TPS) enables individual stepless pretensioning and is placed at one or two levels above the upper instrumented vertebra (UIV+1 and UIV+2, respectively). This study aimed to evaluate a novel customized TPS for the prevention of proximal junctional kyphosis (PJK) and to investigate the potential to generate a smoothe...

Background The Global Alignment and Proportion(GAP) Score is widely used in adult spinal deformity surgery. However, it is not specific to the parameters used in adult cervical deformity(ACD). Purpose Create a cervicothoracic alignment and proportion(CAP) score in operative ACD patients. Study Design/Setting Retrospective single-center study. Me...

OBJECTIVE The objective of this study was to identify the effect of baseline cervical deformity (CD) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adult spinal deformity (ASD). METHODS This study was a retrospective analysis of a prospectively collected, multicenter database comprising ASD patients en...

Zusammenfassung Dieser Artikel beschreibt die Biomechanik der Halswirbelsäule. Das Verständnis von physiologischer Anatomie sowie den funktionellen Zusammenhängen ist Grundlage der Behandlung zervikaler Pathologien. Abweichungen von der physiologischen Biomechanik können zufällig und zunächst ohne Krankheitswert sein, krankheitsbedingt oder iatroge...

Study design: Retrospective cohort study. Objective: Construct an individualized cervical realignment strategy based on patient parameters at the presentation that results in superior 2-year health-related quality of life metrics and decreased rates of junctional failure and reoperation following adult cervical deformity surgery. Summary of bac...

Introduction: Anterior-only multilevel cervical decompression and fusion surgery (AMCS) on 3-5-levels is challenging due to potential complications. Also, outcome predictors after AMCS are poorly understood. Research question: We hypothesize that in patients with at most mild/moderate cervical kyphosis (CK) of the cervical spine, restoration of...

Purpose Measurement of neck rotation is currently reliant on radiologic imaging. Given the radiation exposure for CT imaging and the additional inconvenience for the patients, an alternative assessment is needed. Goniometers are comfortably to use and easy to access, also for private consulting. The aim of this study was the assessment of whether a...

BACKGROUND CONTEXT Current radiographic thresholds have shown inconsistent correlation with clinical outcomes. However, it has not been determined at what point in presenting deformity does sagittal correction tremendously improve clinical outcomes following cervical deformity surgery. PURPOSE Define baseline thresholds in cervical parameters that...

BACKGROUND CONTEXT Research has been concentrated on cervical deformity realignment thresholds for achieving desired clinical outcomes while decreasing worrisome complications, like distal junctional failure (DJF) and reoperation. The present study aims to establish a hierarchical order for realignment of spinopelvic parameters during ACD surgery....

BACKGROUND CONTEXT Patients with less severe adult spinal deformity undergo surgical correction and often achieve good clinical outcomes. However, it is not well understood how much clinical improvement is due to sagittal correction. PURPOSE Derive baseline thresholds in radiographic parameters that, when exceeded, result in dramatic clinical impr...

BACKGROUND CONTEXT A previous study by Pellisé et al identified strong preoperative and surgical predictors of major complications. It is unknown which of these risk factors has the most significant impact on cost-effectiveness. PURPOSE To assess the impact of previously established risk factors on the cost effectiveness of ASD surgery. STUDY DES...

Study design: Retrospective, single-center case study. Objective: Postoperative cervical imbalance with cervical sagittal vertical axis (cSVA) >4 cm can be predicted in 3-level to 5-level anterior-only cervical multilevel fusion surgery (ACMS). Summary of background data: Previous studies established correlations between cervical kyphosis (CK)...

INTRODUCTION The regions of the spine are often referred to a chain of correlation, where malalignment in one aspect may cause compensatory changes in another area of the spine or lower extremities. METHODS Included: operative ASD patients (Coronal Cobb = 20°, SVA = 50 mm, PT = 25°, or TK > 60°) >18 yrs with concurrent cervical deformity (C2-C7 ky...

OBJECTIVE Three-column osteotomy (3CO) is used for severe spinal deformities. Associated complications include sagittal translation (ST), which can lead to neurological symptoms. Mismatch between the surgical center of rotation (COR) and the concept of the ideal COR is a potential cause of ST. Matching surgical with conceptual COR is difficult with...

Objective: In double and triple major adolescent idiopathic scoliosis curves it is still controversial whether the lowest instrumented vertebra (LIV) should be L3 or L4. Too short a fusion can impede postoperative distal curve compensation and promote adding on (AON). Longer fusions lower the chance of compensation by alignment changes of the lumb...

OBJECTIVE The ideal strategy for high-grade L5–S1 isthmic spondylolisthesis (HGS) remains controversial. Critical questions include the impact of reduction on clinical outcomes, rate of pseudarthrosis, and postoperative foot drop. The scope of this study was to delineate predictors of radiographic and clinical outcome factors after surgery for HGS...

Purpose Stabilization of C1-2 using a Harms–Goel construct with 3.5 mm titanium (Ti) rods has been established as a standard of reference (SOR). A reduction in craniocervical deformities can indicate increased construct stiffness at C1-2. A reduction in C1-2 can result in C1-2 joint gapping. Therefore, the authors sought to study the biomechanical...

IntroductionCorrection of severe idiopathic scoliosis poses surgical challenges. Treatment options entail anterior and/or posterior release, Halo-gravity traction (HGT) and three-column osteotomies (3CO). The authors report results with a novel technique of temporary short-term magnetically controlled growing rod (MCGR) as part of a posterior-only...

Objective Anterior-only reconstructions for cervical multilevel corpectomies are prone to fail under continuous mechanical loading. This study sought to define the mechanical characteristics of different constructs in reducing a range of motion (ROM) of the 3-column destabilized cervical spine, including posterior cobalt-chromium (CoCr)-rods, outri...

This article gives a brief overview of the importance, planning and correction of coronal spinal imbalance in patients with adult and pediatric spinal deformity.

Study design: Cross-sectional population-based study. Purpose: The study objective was to evaluate the coexistence of neck- and shoulder-disability, to establish normative scores for Neck Disability Index (NDI), Visual Analog Scale (VAS)-neck, VAS-arm, Quick Disability of Shoulder and Hand (Quick-DASH), and modified Constant score (mConstant sco...

Purpose Proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery patients is a severe complication with potential need for revision surgery. While thoracic kyphosis (TK) is known to influence PJK, the role of TK flexibility is still unknown. We analyzed the influence of TK flexibility to predict postoperative sagittal alignment....

Objective: Computed tomography (CT) scans are accepted as the imaging standard of reference to define union after anterior cervical discectomy and fusion (ACDF). However, ideal CT criteria to diagnose union have not been identified or validated. The objective of this study was to analyze the diagnostic value of 9 CT-based criteria and identify the...

Introduction Accurate prediction of spontaneous lumbar curve correction (SLCC) after selective thoracic fusion (STF) remains difficult. This study sought to improve prediction accuracy of SLCC. The hypothesis was preoperative and intraoperative variables could predict SLCC < 20°. Methods A multicenter observational prospective analysis was conduct...

This comprehensive, up-to-date textbook of modern cervical spine surgery describes the standard and advanced techniques recommended by the Cervical Spine Research Society – European Section (CSRS-E) with a view to enabling both young and experienced surgeons to further develop their skills and improve their surgical outcomes. Success in cervical sp...

This chapter introduces the concepts of assessment of cervical deformity as well as planning of cervical deformity (CD) surgery. It highlights the unique characteristics of preoperative analysis indicated in CD surgery to prevent complications. Advances in surgical instrumentation of the cervical spine and anesthesia have facilitated even lengthy s...

In the treatment of atlantoaxial instability, C1 translaminar screws are an alternative to lateral mass screws for rigid fixation of the atlantoaxial joint. In addition, a C1 laminar screw can be used as adjunct to common C1 lateral mass screws to increase atlantoaxial construct stability in the treatment of advanced deformities of C0–C2. In this c...

Introduction and purpose Little information exists on surgical characteristics, complications and outcomes with corrective surgery for rigid cervical kyphosis (CK). To collate the experience of international experts, the CSRS-Europe initiated an international multi-centre retrospective study. Methods Included were patients at all ages with rigid C...

Zusammenfassung Die Korrektur von Wirbelsäulendeformitäten beim M. Bechterew erfordert eine große operative Erfahrung. Ist die OP-Indikation bei Absenkung der Blickachse und damit verbundener Einschränkung der Lebensqualität recht klar zu stellen, so erfordert die OP-Planung eine sorgfältige Beurteilung der individuellen Anatomie und des sagittalen...

Background: Surgical correction of severe and rigid cervical kyphosis with chin-on-chest deformity poses significant challenges to both the patient and surgeon once surgery is considered as the treatment of choice. Objectives: This article presents the current concepts of corrective surgery for patients with severe and rigid cervical kyphosis....

Background: Surgical correction of ASD can be challenging. The indication for surgery is individual and after specification of the therapeutic goals, detailed planning of the surgery is essential to achieve a good postoperative result. Complications and indication: The reasons for the comparatively high complication rate are well investigated an...

Introduction: This article presents the current concepts of correction of spinal deformity in ankylosing spondylitis (AS) patients. Untreated AS can be a debilitating disease. In a few patients, disease progression results in severe spinal deformity affecting not only the thoracolumbar, but also the cervical spine. Surgery for correction in AS pat...

Purpose: Controversy persists as to whether to end multilevel thoracolumbar fusions caudally at L5 or S1. Some argue that stopping at L5 may preserve greater function, but there are few data comparing functional limitations due to lumbar stiffness in patients with fusion to L5 versus S1. The aim of this study was to evaluate whether patients under...

Introduction and purposeIsolated thoracoplasty (iTP) on the convex side is performed long time after scoliosis surgery has been performed. ITP is thought to cause a further decline in pulmonary function (PF); however, the amount of decline is ill defined. The objectives of this study were to examine the influence of iTP on the postoperative evoluti...

Objective . Long-term radiological and clinical outcome retrospective study of surgical treatment for T12 and L1 burst fractures in perspective of sagittal balance measures. Methods . Patients with age of 16–60 years, complete radiographs, early surgical treatment surgery, and follow-up (F/U) > 18 months were included and strict exclusion criteria...

Study design: Biomechanical Laboratory Study. Objective: Analysis of the biomechanical characteristics of a novel sacral constrained dual-screw fixation device (S1-PALA), combining a S1-pedicle screw and a S1-ala screw, compared to a standard bicortical S1-pedicle screw (S1-PS) fixation. Summary of background data: Instrumented fusions to the...

Introduction/purpose In adult scoliosis surgery (AS) delineation of risk factors contributing to failure is important to improve patient care. Treatment goals include deformity correction resulting in a balanced spine and horizontal lowest instrumented vertebra (LIV) in fusions not ending at S1. Therefore, the study objectives were to determine pr...

Object: Sagittal malalignment of the cervical spine has been associated with worsened postsurgical outcomes. For better operative planning of fusion and alignment restoration, improved knowledge of ideal fusion angles and interdependences between upper and lower cervical spine alignment is needed. Because spinal and spinopelvic parameters might pl...

Study design: Retrospective radiographic benchmark study. Objective: To evaluate the amount of instrumented correction obtained from a combined anterior/posterior (A/P) versus posterior-only (post-only) approach for Scheuermann's kyphosis. Summary of background data: An A/P approach was thought to optimize correction; however, instrumentation...

In Lenke 2 curves, there are conflicting data when to include the PTC into the fusion. Studies focusing on Lenke 2 curves are scant. The number of patients with significant postoperative shoulder height difference (SHD) or trunk shift (TS) is as high as 30 % indicating further research. Therefore, the purpose of the current study was to improve und...

This was a prospective randomized comparative study. The aim of this study was to objectify donor site-related pain following anterior iliac crest graft harvesting, in patients who have undergone multilevel anterior cervical discectomy and fusion with plating (ACDFP); and to assess the effect of an intraoperative local single injection of ropivacai...

A high rate of complications in multilevel cervical surgery with corpectomies and anterior-only screw-and-plate stabilization is reported. A 360°-instrumentation improves construct stiffness and fusion rates, but adds the morbidity of a second approach. A novel ATS-technique (technique that used anterior transpedicular screw placement) was recently...

Study design: This study examines the correlations between pulmonary function tests (PFTs) and radiographical measures of spinal deformities in patients with scoliosis. Objective: To define the parameters that enable more accurate predictions of restricted pulmonary function (PF) in patients with scoliosis. Summary of background data: The earl...

Introduction Failure to select the appropriate lowest instrumented vertebra (LIV) in selective lumbar fusion (SLF) for thoracolumbar/lumbar curves (LC) can result in adding-on in the lumbar curve (LC) or the need for fusion extension due to a decompensating thoracic curve (TC). The selection criteria that predict optimal outcomes still need to be...

The decision of when to use selective thoracic fusion (STF) and the prediction of spontaneous lumbar curve correction (SLCC) remain difficult. Using a novel methodological approach, the authors yielded for a better prediction of SLCC and analyzed the efficacy of anterior scoliosis correction and fusion (ASF). A retrospective analysis of 273 patient...

Study design: Biomechanical in vitro laboratory study. Objective: To compare the biomechanical performance of 3 fixation concepts used for anterior instrumented scoliosis correction and fusion (AISF). Summary of background data: AISF is an ideal estimate for selective fusion in adolescent idiopathic scoliosis. Correction is mediated using rods...

There is sparse literature on how best to correct Scheuermann's kyphosis (SK). The efficacy of a combined strategy with anterior release and posterior fusion (AR/PSF) with regard to correction rate and outcome is yet to be determined. A review of a consecutive series of SK patients treated with AR/PSF using pedicle screw-rod systems was performed....

Recurrence after first-time traumatic anterior shoulder dislocation is frequent. The prevalence of glenoid bone loss ranges from 41% after a first-time dislocation to 86% with recurrent dislocation. Postoperative recurrence can occur in up to 10% of cases. Thus, misdiagnosis of bony glenoid rim lesions has been assumed a major cause for failure. We...

Purpose Recent literature shows that occult discoligamentous injuries still remain difficult to diagnose in the first instance. Thresholds as indicators for discoligamentous segmental instability were previously defined. But, since supine radiodiagnostic is prone to spontaneous reduction of a displaced injury, and even some highly unstable injuries...

Study design: Histological and ultrastructural evaluation of cell morphologies at the concave and convex side of apical intervertebral discs (IVD) of adolescent idiopathic scoliosis (AIS). Objective: To determine changes in cell morphology, viability, and cell death after asymmetric disc loading in AIS and to compare the findings with the tilt a...

Introduction Cervical laminectomy is a reliable tool for posterior decompression in various cervical spine pathologies. Although there is increasing evidence of superior clinical, neurological and radiological outcomes when using anterior cervical decompression, laminectomy can be a valuable tool when combined with instrumented lateral mass fusion...

Background context: In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study. Purpose: To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC treatment algorithm outcome improved agreement...

Objective: Increasing construct stability of lumbosacral instrumentations using S2-ala screws as an alternate to iliac screws. Indications: Revision surgery after failed lumbosacral fusion; long instrumentations to the sacrum; L5-S1 fusion without anterior support. Contraindications: Lack of sacral bone stock. Surgical technique: Midline app...

Background context: Spinal deformity surgery in elderly patients is associated with an increased risk of implant loosening due to failure at the screw-bone interface. Several techniques can be used to increase the screw anchorage characteristics. Cement-augmented screw fixation was shown to be the most efficient method; however, this technique is...

Introduction With progression of cervicothoracic kyphosis (CTK), ankylosing spondylitis (AS) patients suffer functional disability. Surgical correction still poses neurologic risks, while evidence of an ideal technique preventing its complications is weak. Materials and methods We report our results with non-instrumented correction in perspective o...

Introduction To better understand cervical kinematics following cervical disc replacement (CDR), the in vivo behavior of a minimally constrained CDR was assessed. Methods Radiographic analysis of 19 patients undergoing a 1-level CDR from C4–5 to C6–7 (DISCOVER, Depuy-Spine, USA) was performed. Neutral–lateral and flexion–extension radiographs obtai...

In posttraumatic shoulder dislocation, the size of a glenoid rim defect can determine the probability of recurrent dislocations. Most attempts to assess the size of such defects are based on the width of a defect in relation to glenoid length or diameter. So far, no method exactly calculating the area of articular surface missing has been reported....

Study purpose With increasing usage within challenging biomechanical constructs, failures of C2 posterior cervical pedicle screws (C2-pCPSs) will occur. The purpose of the study was therefore to investigate the biomechanical characteristics of two revision techniques after the failure of C2-pCPSs. Materials and methods Twelve human C2 vertebrae wer...

In thoracolumbar deformity surgery, anterior-only approaches are used for reconstruction of anterior column failures. It is generally advised that vertebral body replacements (VBRs) should be preloaded by compression. However, little is known regarding the impact of different techniques for generation of preloads and which surgical principle is bes...

STUDY DESIGN.: Retrospective study of a consecutive series of operatively managed patients with cervical fractures with diffuse idiopathic skeletal hyperostosis (DISH) presenting to 3 institutions over an 8 year period. OBJECTIVE.: Assess demographics, fracture characteristics, outcome and complications in patients managed surgically. SUMMARY OF BA...

Study design: Retrospective review of a case series. Objective: To present the radiologic and surgical characteristics of scoliosis treatment in patients with Marfan syndrome (MFS). Summary of background data: The treatment of scoliosis in MFS has been reported to pose unique challenges. However, the information on surgical outcomes is sparse....

The treatment of rigid and severe scoliosis and kyphoscoliosis is a surgical challenge. Presurgical halo-gravity traction (HGT) achieves an increase in curve flexibility, a reduction in neurologic risks through gradual traction on a chronically tethered cord and an improvement in preoperative pulmonary function. However, little is known with respec...

As the population continues to age, relatively older geriatric patients will present more frequently with complex spinal deformities that may require surgical intervention. To the authors' knowledge, no study has analyzed factors predictive of complications after major spinal deformity surgery in the very elderly (75 years and older). The authors'...

Background Latissimus dorsi tendon transfer represents a well-established method for the treatment of massive irreparable posterosuperior rotator cuff defects. Subsequent rupture of the transferred tendon may contribute to the failure rate of the index procedure. We assumed that by modifying our tendon harvesting technique, higher fixation stabilit...

Die posttraumatische Kyphose (PTK) kann die Folge einer übersehenen Fraktur, einer falsch indizierten konservativen Behandlung oder einer falsch durchgeführten operativen Therapie sein. Ebenso tritt sie als schicksalhafter Verlauf einer adäquat durchgeführten Behandlung auf. Der Vermeidung der PTK kommt eine große Bedeutung zu, da die nachfolgenden...

Posttraumatic kyphosis (PTK) is a possible consequence of a missed fracture, a wrong indication for conservative therapy or an inadequate surgical technique but PTK can also be a complication after adequate surgery. Avoidance of PTK is of importance because subsequent surgical therapy can be extensive. A thorough planning as well as surgical experi...

The suture-bridge technique using anchors as established transosseous-equivalent technique in arthroscopic rotator cuff repair was compared to a modified transosseous technique suitable for arthroscopic cuff repair. In 10 fresh-frozen matched pairs of human cadaveric shoulders (mean age 67.1, SD 8.5 years), two different surgical techniques of cuff...

In the elderly population, reported union rates with anterior odontoid screw fixation (AOSF) for odontoid fracture (OF) treatment vary between 23 and 93% when using plain radiographs. However, recent research revealed poor interobserver reliability for fusion assessment using plain radiographs compared to CT scans. Therefore, union rates in patient...

Clinical studies reported frequent failure with anterior instrumented multilevel cervical corpectomies. Hence, posterior augmentation was recommended but necessitates a second approach. Thus, an author group evaluated the feasibility, pull-out characteristics, and accuracy of anterior transpedicular screw (ATPS) fixation. Although first success wit...

Clinical studies reported frequent failure with anterior instrumented multilevel cervical corpectomies. Hence, posterior augmentation was recommended but necessitates a second approach. Thus, an author group evaluated the feasibility, pull-out characteristics, and accuracy of anterior transpedicular screw (ATPS) fixation. Although first success wit...

Retrospective study. To analyze the patient satisfaction and the patients' perceived approach-related morbidity (ArM) after open thoracotomy (OTC) for instrumented anterior scoliosis surgery. There is no mid- to long-term data on the patients' perceived ArM concerning chest wall dissection for open anterior scoliosis correction. A specific question...

Only a few reports exist concerning biomechanical challenges spine surgeons face when treating Parkinson's disease (PD) patients with spinal deformity. We recognized patients suffering from spinal deformity aggravated by the burden of PD to stress the principles of sagittal balance in surgical treatment. Treatment of sagittal imbalance in PD is dif...

A total of 12 human cervical spines were tested in vitro in a biomechanical nondestructive set-up to compare the primary stability of different posterior cervical instrumentations after a bilevel corpectomy. To evaluate the primary 3-dimensional stability with special focus on the impact of cervical pedicle screws. Cervical pedicle screw fixation g...

The complication rate of periprosthetic femoral fractures above well-fixed total knee arthroplasties is high. The Less Invasive Stabilization System (LISS) was introduced to reduce surgical dissections at the fracture site. The purpose of this retrospective study was to evaluate the midterm functional outcome of a group of patients with periprosthe...

High tibial osteotomy has been recognized as a beneficial treatment for osteoarthritis of the medial compartment of the knee. The purpose of this prospective study was to assess the short-term results of opening-wedge high tibial osteotomies with locked plate fixation. From September 2002 to November 2005, fifty-one consecutive medial opening-wedge...

Latissimus dorsi tendon transfer is a well-established method for the treatment of massive irreparable posterosuperior defects of the rotator cuff. Subsequent rupture of the transferred tendon may contribute to the rate of failure of the index procedure. We hypothesized that modification of our technique of tendon harvesting would lead to greater f...

Object The purpose of this retrospective study was to quantify the anatomical relationship between the vertebral artery (VA), the cervical pedicle, and its surrounding structures, including the incidence of irregularities. Additionally, data delineating a “safe zone,” and these data's application during instrumentation with transpedicular cervical...

Biplane radiologic evaluation is indispensable for the correct diagnosis of acute acromioclavicular (AC) joint injuries. Thus far, no functional radiographic techniques have been quantified to evaluate horizontal instability in acute AC joint dislocations. Supine dynamic axillary lateral shoulder views detect horizontal instability of the distal cl...

Nonsurgical treatment of Jefferson burst fractures (JBF) confers increased rates of C1-2 malunion with potential for cranial settling and neurologic sequels. Hence, fusion C1-2 was recognized as the superior treatment for displaced JBF, but sacrifies C1-2 motion. Ruf et al. introduced the C1-ring osteosynthesis (C1-RO). First results were favorable...