Heiko Koller
Salk Institute for Biological Studies
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Heiko Koller.
American Journal of Sports Medicine | 2009
Mark Tauber; Katharina Gordon; Heiko Koller; Michael Fox; Herbert Resch
Background Biomechanical studies comparing various surgical techniques for acromioclavicular joint reconstruction have reported that semitendinosus tendon graft for coracoclavicular ligament reconstruction provides a substantial improvement in initial stability and a load-to-failure equivalent to the intact coracoclavicular ligaments. Although it represents a biomechanical improvement compared with coracoacromial ligament transfer, there is still a lack of prospective comparative studies confirming the clinical relevance of these biomechanical findings. Hypothesis Semitendinosus tendon graft for coracoclavicular ligament reconstruction is associated with superior clinical results compared with a modified Weaver-Dunn procedure in chronic complete acromioclavicular joint dislocation. Study Design Cohort study; Level of evidence, 2. Methods Twenty-four patients (mean age, 42 years) with painful, chronic Rockwood type III through V acromioclavicular joint dislocations were subjected to surgical reconstruction. In 12 patients, a modified Weaver-Dunn procedure was performed; in the other 12 patients, autogenous semitendinosus tendon graft was used. Clinical evaluation was performed using the American Shoulder and Elbow Surgeons shoulder score and the Constant score after a mean follow-up time of 37 months. Preoperative and postoperative radiographs were compared. Results The mean American Shoulder and Elbow Surgeons shoulder score improved from 74 ± 7 points preoperatively to 86 ± 8 points postoperatively in the Weaver-Dunn group, and from 74 ± 4 points to 96 ± 5 points in the semitendinosus tendon group (P < .001 for both techniques). The mean Constant score improved from 70 ± 8 points to 81 ± 8 points in the Weaver-Dunn group, and from 71 ± 5 points to 93 ± 7 points in the semitendinosus tendon group (P < .001). The results in the semitendinosus tendon group were significantly better than in the Weaver-Dunn group (P < .001). The radiologic measurements showed a mean coracoclavicular distance of 12.3 ± 4 mm in the Weaver-Dunn group increasing to 14.9 ± 6 mm under stress loading, compared with 11.4 ± 3 mm increasing to 11.8 ± 3 mm under stress in the semitendinosus tendon group. The difference during stress loading was statistically significant (P = .027). In the semitendinosus tendon group, horizontal displacement of the lateral clavicle end could be reduced in all cases with type IV dislocation. Conclusion Semitendinosus tendon graft for coracoclavicular ligament reconstruction resulted in significantly superior clinical and radiologic outcomes compared to the modified Weaver-Dunn procedure.
American Journal of Sports Medicine | 2010
Mark Tauber; Heiko Koller; Wolfgang Hitzl; Herbert Resch
Background: 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. Hypothesis: Supine dynamic axillary lateral shoulder views detect horizontal instability of the distal clavicle in patients with acute AC joint dislocations. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: Twenty-five consecutive patients with a mean age of 39 ± 14 years with acute AC joint injury underwent biplane radiologic evaluation, including a conventional Zanca view and an axillary lateral view in a sitting position. In addition, supine axillary lateral views with the arm in 90° of abduction and 60° of flexion and extension were taken to evaluate the horizontal dynamics of the distal clavicle. The gleno-acromio-clavicular angle (GACA) was introduced and used to quantify the horizontal clavicular dynamics in terms of angle differences. The unaffected shoulders served as the control group. Results: Superior dislocation of the lateral clavicle in the Zanca view was classified as Rockwood type II in 7 patients, type III in 15, and type V in 3. The axillary lateral view in a sitting position showed posterior dislocation of the distal clavicle in 8 patients (Rockwood type IV injury). Dynamic radiologic evaluation revealed an average GACA difference between the neutral and anterior position of the arm of 7.1° ± 5.5° for the unaffected shoulder. In the injured AC joints, 11 patients showed no radiologic evidence of horizontal instability (group A) with a GACA difference of 7.1° ± 4.8°. Increased anteroposterior translation was evident in 14 patients (group B) with a GACA difference of 30.3° ± 14.3° (P < .001). Conclusion: Functional axillary radiologic evaluation seems to represent a simple imaging tool to reveal dynamic horizontal instability. Clinical Relevance: Horizontal instability of the distal clavicle in acute AC joint injuries represents an indication for surgical treatment. Dynamic axillary radiologic evaluation may detect previously missed unstable injuries. This evaluation might be relevant when deciding on surgical AC joint stabilization.
Journal of Bone and Joint Surgery, American Volume | 2009
Mohamed Moursy; Rosemarie Forstner; Heiko Koller; Herbert Resch; Mark Tauber
BACKGROUND 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 fixation stability and a reduced failure rate. METHODS Forty-two patients (mean age, fifty-eight years) with a massive irreparable posterosuperior tear of the rotator cuff were managed with a latissimus dorsi tendon transfer. Sharp separation of the latissimus tendon from the humerus was performed in twenty-two patients (Group A), whereas the tendon harvest was carried out with a modified technique that involved removal of some bone along with the tendon at the humeral insertion in a subsequent group of twenty patients (Group B). The mean duration of follow-up was forty-seven months. Outcome measures included the Constant and American Shoulder and Elbow Surgeons (ASES) scores and a patient subjective satisfaction scale. Standard radiographs were made to determine the stage of osteoarthritis and proximal migration of the humeral head, and magnetic resonance imaging was performed to assess the integrity of the transferred muscle. RESULTS In Group A, the mean Constant score improved from 43.4 preoperatively to 64.8 points at the time of follow-up and the mean ASES score improved from 49.3 to 69.6 points (p < 0.05). In Group B, the mean Constant score increased from 40.2 to 74.2 points and the mean ASES score, from 47.2 to 77.1 points (p < 0.05). The Constant pain score improved from 5.6 to 11.9 points in Group A and from 5.2 to 13.8 points in Group B. The results in Group B were significantly superior to those in Group A (p < 0.05). Magnetic resonance imaging revealed complete rupture at the tendon insertion with tendon retraction in four patients in Group A and none in Group B. The final outcome was rated as poor in 27% of the patients in Group A and in 10% in Group B. CONCLUSIONS Latissimus dorsi tendon transfer achieves satisfactory clinical results in most patients who have a massive irreparable posterosuperior tear of the rotator cuff. Harvesting the tendon along with a small piece of bone enables direct bone-to-bone transosseous fixation, resulting in better tendon integrity and clinical results.
Journal of Trauma-injury Infection and Critical Care | 2008
Werner Kolb; Hanno Guhlmann; Christoph Windisch; Frank Marx; Klaus Kolb; Heiko Koller
BACKGROUND The Less Invasive Stabilization System (LISS) is an internal fixator, which combines closed reduction of the diaphysis or metaphysis of distal femur fractures with locked unicortical screw fixation. METHODS In a retrospective consecutive study, 50 patients with Association for the Study of the Problems of Internal Fixation/Orthopaedic Trauma Association (AO/OTA) type 33-A1 to 33-C3 fractures were treated with the LISS between January 1999 and December 2003. Final results were assessed using the functional score of Neer after a median follow-up of 29 months (15-48 months). RESULTS Fifteen male and 16 female patients were followed up. The mean age was 49 years (17-90 years). Deep wound infection was seen in one patient (3%) and malpositioning with cutting-out of the proximal screws was in two patients (6%). All other fractures healed uneventfully without bone graft requirements after a mean of 12 weeks (7-20 weeks). A revised osteosynthesis was performed for correction of a valgus deformity of 20 degrees after 4 months. There was no difference in leg length exceeding 2 cm. One patient had a valgus deformity of 10 degrees combined with a rotational deformity of 10 degrees. Range of motion of the knee joint was >120 degrees in 15 patients (48%); 12 (39%) had a range of motion between 90 degrees and 120 degrees and 4 (13%) between 70 degrees and 90 degrees. The function according to the Neer score was excellent in 15 (48%), good in 10 patients (32%), and fair in 6 patients (20%). The mean Neer score was 80 (60-100). CONCLUSIONS The LISS promotes early mobilization and rapid rates of bony and clinical healing without bone grafting with low rates of infection.
Journal of Bone and Joint Surgery, American Volume | 2009
Werner Kolb; Hanno Guhlmann; Christoph Windisch; Klaus Kolb; Heiko Koller; Paul Alfred Grützner
BACKGROUND 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. METHODS From September 2002 to November 2005, fifty-one consecutive medial opening-wedge high tibial osteotomies were performed. The mean age of the patients at the time of the index operation was forty-nine years. The preoperative and postoperative factors analyzed included the grade of arthritis of the tibiofemoral compartment (the Ahlbäck radiographic grade), the anatomic tibiofemoral angle, patellar height, the Hospital for Special Surgery rating system score, and the Lysholm and Gillquist knee score. RESULTS Postoperatively, one superficial wound infection occurred. Fifty of the fifty-one osteotomies healed after an average period of 12.9 weeks (range, eight to sixteen weeks) without bone grafts. A nonunion developed in a sixty-two-year-old patient who was a cigarette smoker. The average postoperative tibiofemoral angle was 9 degrees of valgus. Forty-nine patients were followed for a mean of fifty-two months. The average score on the Hospital for Special Surgery rating system was 86 points at the time of the most recent follow-up. The rating was excellent in twenty-eight patients (57%), good in twelve (24%), fair in four (8%), and poor in five (10%). The average score on the Lysholm and Gillquist knee-scoring scale was 83 points. According to these scores, the outcome was excellent in nine patients (18%), good in thirty-one (63%), fair in three (6%), and poor in six (12%). Four knees failed after an average of thirty-six months. CONCLUSIONS Our results suggest that an opening-wedge high tibial osteotomy with locked plate fixation allows a correct valgus angle to be achieved with good short-term results.
Journal of Trauma-injury Infection and Critical Care | 2009
Mark Tauber; Heiko Koller; Philipp Moroder; Wolfgang Hitzl; Herbert Resch
BACKGROUND Low-dose acetylsalicylate acid (LDA) therapy is accepted as a major risk factor for intracranial hemorrhages (ICH) in head injuries. Coincidentally, patient admissions that might be indicated for in hospital observation of neurologic function causes increased health care costs. In the literature, there is no evidence concerning the incidence of secondary intracranial hemorrhagic events (SIHE) in patients with LDA prophylaxis that had negative primary computed tomography (CT)-scan of the head. METHODS In this prospective study, we enrolled 100 consecutive trauma patients older than 65 years presenting in a Level I urban trauma center after a mild head injury (Glasgow Coma Scale score of 15) who had LDA prophylaxis. Patients included had a negative primary head CT-scan concerning ICH. For analysis of the incidence of SIHEs patients had routine repeat head CT (RRHCT) after 12 hours to 24 hours. RESULTS Sixty-one patients were women and 39 men. Mean age was 81 years +/- 10 years. Injury mechanism was a level fall in 84 cases and others in 16. In four patients (4%) an SIHE was detected in the RRHCT (p < 0.00001). In two patients (2%) major secondary ICH had occurred without neurologic deterioration at the time of RRHCT with fatal outcome in one patient and neurosurgical intervention in another. The remaining two patients (2%) had minor SIHE with an uneventful clinical course. CONCLUSION The incidence of SIHE has been neglected until now. The current study revealed that patients with LDA prophylaxis after mild head injury with negative primary head CT should be subjected to RRHCT within 12 hours to 24 hours to accurately identify SIHE. Alternatively to RRHCT, patients should be subjected to a prolonged in-hospital observation for at least 48 hours.
Knee Surgery, Sports Traumatology, Arthroscopy | 2008
Mark Tauber; Heiko Koller; Herbert Resch
Partial articular-surface tendon avulsion (PASTA) lesions of the supraspinatus muscle represent a common cause for shoulder impairment and a preceding pathology for full-thickness tendon tears. Arthroscopic tendon repair is a possible surgical method of treatment. The purposes of cuff repair are anatomical tendon healing, prevention of tear size progression to completion and reduction of shoulder pain. In this report, we describe a transtendon arthroscopic technique of transosseous refixation of articular-side partial tears leaving the bursal layer of the supraspinatus tendon intact. A curved hollow needle is used to perform an all arthroscopic transosseous mattress suture. Thus, anatomical tendon-to-bone contact of the rotator cuff to the footprint is restored. Preliminary clinical results of 16 patients are convincing with significant pain relief and functional improvement.
European Spine Journal | 2008
Heiko Koller; Frank L. Acosta; Axel Hempfing; David Rohrmüller; Mark Tauber; Stefan Lederer; Herbert Resch; Juliane Zenner; Helmut Klampfer; Robert Schwaiger; Robert Bogner; Wolfgang Hitzl
The nonsurgical treatment of thoracolumbar (TLB) and lumbar burst (LB) fractures remains to be of interest, though it is not costly and avoids surgical risks. However, a subset of distinct burst fracture patterns tend to go with a suboptimal radiographic and clinical long-term outcome. Detailed fracture pattern and treatment-related results in terms of validated outcome measures are still lacking. In addition, there are controversial data on the impact of local posttraumatic kyphosis that is associated, in particular, with nonsurgical treatment. The assessment of global spinal balance following burst fractures has not been assesed, yet. Therefore, the current study intended to investigate the radiographical and clinical long-term outcome in neurologically intact patients with special focus on the impact of regional posttraumatic kyphosis, adjacent-level compensatoric mechanisms, and global spine balance on the clinical outcome. For the purpose of a homogenous sample, strong in- and exclusion criteria were applied that resulted in a final study sample of 21 patients with a mean follow-up of 9.5 years. Overall, clinical outcome evaluated by validated measures was diminished, with 62% showing a good or excellent outcome and 38% a moderate or poor outcome in terms of the Greenough Low Back Outcome Scale. Notably, vertebral comminution in terms of the load-sharing classification, posttraumatic kyphosis, and an overall decreased lumbopelvic lordosis showed a significant effect on clinical outcome. A global and segmental curve analysis of the spine T9 to S1 revealed significant alterations as compared to normals. But, the interdependence of spinopelvic parameters was not disrupted. The patients’ spinal adaptability to compensate for the posttraumatic kyphotic deformity varied in the ranges dictated by pelvic geometry, in particular the pelvic incidence. The study substantiates the concept that surgical reconstruction and maintenance of a physiologically shaped spinal curve might be the appropriate treatment in the more severely crushed TLB and LB fractures.
European Spine Journal | 2006
Heiko Koller; Volker Kammermeier; Dietmar Ulbricht; Allan Assuncao; Stefan Karolus; Boris van den Berg; Ulrich Holz
Posterior transarticular screw fixation C1-2 with the Magerl technique is a challenging procedure for stabilization of atlantoaxial instabilities. Although its high primary stability favoured it to sublaminar wire-based techniques, the close merging of the vertebral artery (VA) and its violation during screw passage inside the axis emphasizes its potential risk. Also, posterior approach to the upper cervical spine produces extensive, as well as traumatic soft-tissue stripping. In comparison, anterior transarticular screw fixation C1-2 is an atraumatic technique, but has been neglected in the literature, even though promising results are published and lectured to date. In 2004, anterior screw fixation C1-2 was introduced in our department for the treatment of atlantoaxial instabilities. As it showed convincing results, its general anatomic feasibility was worked up. The distance between mid-sagittal line of C2 and medial border of the VA groove resembles the most important anatomic landmark in anterior transarticular screw fixation C1-2. Therefore, CT based measurements on 42 healthy specimens without pathology of the cervical spine were performed. Our data are compiled in an extended collection of anatomic landmarks relevant for anterior transarticular screw fixation C1-2. Based on anatomic findings, the technique and its feasibility in daily clinical work is depicted and discussed on our preliminary results in seven patients.
European Spine Journal | 2009
Heiko Koller; Wolfgang Hitzl; Frank L. Acosta; Mark Tauber; Juliane Zenner; Herbert Resch; Yasutsugu Yukawa; Oliver Meier; René Schmidt; Michael Mayer
Reconstruction of the highly unstable, anteriorly decompressed cervical spine poses biomechanical challenges to current stabilization strategies, including circumferential instrumented fusion, to prevent failure. To avoid secondary posterior surgery, particularly in the elderly population, while increasing primary construct rigidity of anterior-only reconstructions, the authors introduced the concept of anterior transpedicular screw (ATPS) fixation and plating. We demonstrated its morphological feasibility, its superior biomechanical pull-out characteristics compared with vertebral body screws and the accuracy of inserting ATPS using a manual fluoroscopically assisted technique. Although accuracy was high, showing non-critical breaches in the axial and sagittal plane in 78 and 96%, further research was indicated refining technique and increasing accuracy. In light of first clinical case series, the authors analyzed the impact of using an electronic conductivity device (ECD, PediGuard) on the accuracy of ATPS insertion. As there exist only experiences in thoracolumbar surgery the versatility of the ECD was also assessed for posterior cervical pedicle screw fixation (pCPS). 30 ATPS and 30 pCPS were inserted alternately into the C3–T1 vertebra of five fresh-frozen specimen. Fluoroscopic assistance was only used for the entry point selection, pedicle tract preparation was done using the ECD. Preoperative CT scans were assessed for sclerosis at the pedicle entrance or core, and vertebrae with dense pedicles were excluded. Pre- and postoperative reconstructed CT scans were analyzed for pedicle screw positions according to a previously established grading system. Statistical analysis revealed an astonishingly high accuracy for the ATPS group with no critical screw position (0%) in axial or sagittal plane. In the pCPS group, 88.9% of screws inserted showed non-critical screw position, while 11.1% showed critical pedicle perforations. The usage of an ECD for posterior and anterior pedicle screw tract preparation with the exclusion of dense cortical pedicles was shown to be a successful and clinically sound concept with high-accuracy rates for ATPS and pCPS. In concert with fluoroscopic guidance and pedicle axis views, application of an ECD and exclusion of dense cortical pedicles might increase comfort and safety with the clinical use of pCPS. In addition, we presented a reasonable laboratory setting for the clinical introduction of an ATPS-plate system.