Johannes Oppermann

The femoral neck-shaft angle on plain radiographs: a systematic review

ObjectiveThe femoral neck-shaft angle (NSA) is an important measure for the assessment of the anatomy of the hip and planning of operations. Despite its common use, there remains disagreement concerning the method of measurement and the correction of hip rotation and femoral version of the projected NSA on conventional radiographs. We addressed the following questions: (1) What are the reported values for NSA in normal adult subjects and in osteoarthritis? (2) Is there a difference between non-corrected and rotation-corrected measurements? (3) Which methods are used for measuring the NSA on plain radiographs? (4) What could be learned from an analysis of the intra- and interobserver reliability?Material and methodsA systematic literature search was performed including 26 publications reporting the measurement of the NSA on conventional radiographs.ResultsThe mean NSA of healthy adults (5,089 hips) was 128.8° (98–180°) and 131.5° (115–155°) in patients with osteoarthritis (1230 hips). The mean NSA was 128.5° (127–130.5°) for the rotation-corrected and 129.5° (119.6–151°) for the non-corrected measurements.ConclusionOur data showed a high variance of the reported neck-shaft angles. Notably, we identified the inconsistency of the published methods of measurement as a central issue. The reported effect of rotation-correction cannot be reliably verified.

Dislocation Following Total Hip Replacement

BACKGROUND Hip replacement ranks among the more successful operations on the musculoskeletal system, but it can have serious complications. A common one is dislocation of the total hip endoprosthesis, an event that arises in about 2% of patients within 1 year of the operation. Physicians should be aware of how this problem can be prevented and, if necessary, treated, so that the degree of trauma due to hip dislocation after hip replacement surgery can be kept to a minimum. METHODS The authors searched Medline selectively for pertinent publications and analyzed the annual reports of international endoprosthesis registries. RESULTS The rate of dislocation of primary hip replacements ranges from 0.2% to 10% per year, while that of artificial hip joints that have already been surgically revised can be as high as 28%, depending on the patient population, the follow-up interval, and the type of prosthesis. Patient-specific risk factors for displacement of a hip endoprosthesis include advanced age, accompanying neurologic disease, and impaired compliance. Patients should scrupulously avoid hip movements such as bending far forward from a standing position, or internal rotation of the flexed hip. Operation-specific risk factors include suboptimal implant position, insufficient soft-tissue tension, and inadequate experience of the surgeon. Conservative treatment is justified the first time dislocation occurs without any identifiable cause. If a mechanical cause of instability is found, then operative revision should be performed as recommended in a standardized treatment algorithm, because, otherwise, dislocation is likely to recur. CONCLUSION The dislocation of a total hip endoprosthesis is an emotionally traumatizing event that should be prevented if possible. Preoperative risk assessment should be performed and the operation should be performed with optimal technique, including the best possible physical configuration of implant components, soft-tissue balance, and an adequately experienced orthopedic surgeon.

Calibration Markers for Digital Templating in Total Hip Arthroplasty

Digital templating with external calibration markers is the standard method for planning total hip arthroplasty. We determined the geometrical basis of the magnification effect, compared magnification with external and internal calibration markers, and examined the influence on magnification of the position of the calibration markers, patient weight, and body mass index (BMI). A formula was derived to calculate magnification with internal and external calibration markers, informed by 100 digital radiographs of the pelvis. Intraclass correlations between the measured and calculated values and the strength of relationships between magnification, position and distance of calibration markers and height, weight, and BMI were sought. There was a weak correlation between magnification of internal and external calibration markers (r = 0.297–0.361; p < 0.01). Intraclass correlations were 0.882–1.000 (p = 0.000) for all parameters. There were also weak correlations between magnification of internal and external calibration markers and weight and BMI (r = 0.420, p = 0.000; r = 0.428, p = 0.000, respectively). The correlation between external and internal calibration markers was poor, indicating the need for more accurate calibration methods. While weight and BMI weakly correlated with the magnification of markers, future studies should examine this phenomenon in more detail.

Spinal cord injury without radiologic abnormality in children: A systematic review and meta-analysis

BACKGROUND Spinal cord injury in children is associated with severe morbidity and immense socioeconomic burden. In spinal cord injury without radiologic abnormalities (SCIWORA), magnetic resonance imaging (MRI) can detect intramedullary or extramedullary pathologies or show absence of neuroimaging abnormalities. However, the prognostic and therapeutic consequences of specific MRI patterns are unclear. A comprehensive systematic literature search was performed to examine patient characteristics and imaging patterns of pediatric SCIWORA and to evaluate the prognostic value of a MRI-based classification system. METHODS MEDLINE, Cochrane Central Register of Controlled Trials, and Google Scholar were searched for studies on SCIWORA in children. Inclusion criteria were (1) traumatic spinal cord injury with acute neurologic deficit, (2) absence of fractures and/or dislocations of the spine, and (3) an immature skeleton or age of less than 18 years. MRI patterns and clinical course were correlated. RESULTS Forty articles reporting 114 patients were identified. At admission, neurologic deficit assessed by the American Spinal Injury Association impairment scale was A in 28%, B in 17%, C in 31%, and D in 25%. At final follow-up, these were 19%, 6%, 10%, and 16%, respectively. In 43%, no MRI abnormalities (Type I) were detected, and 57% exhibited abnormal scan results (Type II): 6% revealed extraneural (Type IIa), 38% intraneural (Type IIb), and 13% combined abnormalities (Type IIc). At admission and follow-up, American Spinal Injury Association impairment scale differed significantly between the imaging types. CONCLUSION This systematic review emphasizes the prognostic value of spinal MRI for children with SCIWORA. It highlights the role of the MRI classification system in improving the comparability and interpretability. LEVEL OF EVIDENCE Systematic review, level IV.

Einfluss der Transplantatausrichtung des vorderen Bündels des medialen ulnaren Kollateralbandes auf die Valgusstabilität des Ellenbogens

ZusammenfassungZielZiel der vorliegenden Arbeit war es zu überprüfen, ob die Primärstabilität der zweibündeligen Ersatzplastik des medialen ulnaren Kollateralbandes (MUCL) des Ellenbogens mit anatomischer ulnarer Bohrkanalplatzierung der Stabilität der extraanatomischen Platzierung sowie der einbündeligen Ersatzplastik überlegen ist.Material und MethodenEs wurden 10 frische humane Armpräparate mit einem Durchschnittsalter von 76 (58–89) Jahren verwendet. Zunächst wurde die Valgusstabilität am intakten Ellenbogen in 120, 90, 60, 30 und 0 ° Flexion mit einer kontinuierlich ansteigenden Belastung bis 7,5 Nm geprüft. Anschließend erfolgte über einen Muskelsplit der Flexor-Pronator-Gruppe die Durchtrennung des anterioren Bündels des MUCL und die erneute sequenzielle Testung. Danach wurden ulnare Bohrkanäle in anatomischer und nichtanatomischer Position angelegt. In die Bohrkanäle konnten Sehnentransplantate eingezogen werden, um entweder eine Doppelstrang- (Doppelstrang 1 = Bohrkanal im anatomischen Bereich, Doppelstrang 2 = Bohrkanal extraanatomisch) oder eine Einzelstrangrekonstruktion zu simulieren. Es erfolgte mit jeder Transplantatanordnung eine sequentielle Valgusbelastung. Die statistische Auswertung erfolgte mittels Varianzanalyse mit einem Post-hoc-Verfahren nach Scheffé.ErgebnisseBei einer Valgusbelastung von 7,5 Nm betrug die mittlere Valgusverformung bei intaktem MUCL bei 90 ° Ellenbogenbeugung 7,4 ± 2,4° und bei voller Extension 7,4 ± 2,6 °. Eine signifikante Zunahme der Valgusinstabilität konnte nach Durchtrennung des vorderen Bündels des MUCL festgestellt werden (p < 0,001). Sowohl die Doppelstrangrekonstruktionen als auch die Einzelstrangrekonstruktion zeigten im Vergleich zur durchtrennten MUCL-Situation eine signifikante Stabilisierung über den Bewegungsumfang. Es bestand kein signifikanter Unterschied zwischen den drei Rekonstruktionstechniken.DiskussionDie Einzelstrangrekonstruktion kann der Doppelstrangrekonstruktion aufgrund der biomechanischen Ergebnisse gleichgestellt werden. Beide Techniken weisen eine suffiziente Stabilisierung gegen Valgusmomente auf.AbstractBackgroundThe aim of the present study was to examine whether the primary stability of the medial ulnar collateral elbow ligament (UCL) of a double-bundle technique with anatomic drill hole position is superior to a non-anatomical position or a single-bundle technique.Materials and methodsTen fresh-frozen upper extremities (mean age 76 years (range 58–89)) were mounted in the testing apparatus. First, the valgus-stability with intact medial UCL was tested in 120, 90, 60, 30 and 0 ° of flexion with a continuously increasing load to 7.5 Nm. Afterwards the pronator was split and the anterior bundle of the medial UCL cut, followed by a new sequential testing. Ulnar drill holes were installed hereafter, both in an anatomical and non-anatomical position. Tendon grafts were placed to simulate two double bundle (double bundle 1 = drill hole anatomical position; double bundle 2 = drill hole extra-anatomical) and one single bundle reconstruction. Sequential testing was done of each reconstruction. Statistical analysis was performed by means of a variance analysis per Scheffe’s post hoc technique.ResultsIn a valgus stress of 7.5 Nm, mean valgus deformation in an intact MUCL at 90° elbow flexion was 7.4 ± 2.4 ° and at full extension 7.4 ± 2.6 °. A significant increase in valgus instability was observed (p < 0.001) after section of the anterior bundle. The double-bundle and single-bundle reconstructions showed significant stabilization over the range of motion compared to the dissected medial UCL. There was no significant difference between the three reconstruction techniques.ConclusionIn this biomechanical study, the single-bundle reconstruction proved equal to the double-bundle technique. Both techniques showed a sufficient stabilization against valgus stress.

Anatomical transosseous fixation of the deep and superficial fibers of the radioulnar ligaments

IntroductionThe triangular fibrocartilage complex is in conjunction with the interosseous membrane the most important stabilizer of the distal radioulnar joint. Lesions of the triangular fibrocartilage complex may cause instability of the distal radioulnar joint with serious consequences. Therefore, the goal is to reconstruct and provide stability to prevent further harm.Surgical techniqueBased on the anatomical configuration of the radioulnar ligaments, we present a technique which addresses both the deep and the superficial fibers of the radioulnar ligaments. This surgical procedure can be performed either openly or arthroscopically assisted. Two osseous 2-mm tunnels starting from the ulnar neck to the foveal surface are created. A nonabsorbable suture is passed through the tunnels and the triangular fibrocartilage using a 20-gauge venipuncture needle in order to attach the deep fibers. Then a third osseous tunnel starting from the lateral base of the styloid process to the medial aspect is created. The suture is passed through this tunnel and through the triangular fibrocartilage and around the styloid process palmarily using the same needle as before in order to anchor the superficial fibers anatomically. After reducing the ulna head the sutures are tightened.ConclusionThis technique is quite simple and addresses the anatomical configuration of the radioulnar ligaments.

Indications and contraindications: interspinous process decompression devices in lumbar spine surgery.

BACKGROUND Interspinous process decompression devices (IPD) allow a minimally invasive treatment of lumbar spinal stenosis (LSS), but their use is discussed highly controversial. Several level I studies suggest that IPD implantation is a viable alternative for both conservative treatment and decompression, but clear indications and contraindications are still missing. This study was designed to explore the perspectives and limitations of IPDs and to evaluate the role of these devices in general. MATERIAL AND METHODS The study is based on a questionnaire sent to all hospitals registered in the German Hospital Address Register 2010 with an orthopedic, neurosurgerical, or spine surgery department (n = 1,321). The questionnaire was reviewed by experienced spine surgeons and statisticians, and included both single-response, close-ended, and multiple-response open-ended questions. RESULTS We received 329 (24.9%) entirely analyzable questionnaires. A total of 164 respondents (49.8%) stated that IPDs are a treatment option for LSS, and 135 of the 164 respondents (82.3%) use them. Poor clinical experience (60%) and lack of evidence (53.9%) are the main reasons cited for not using IPDs. We detected a high negative correlation between the size of the hospital, the number of outpatients and inpatients treated for LSS and other spine pathologies, and the use of IPDs (p = 0.001). Most respondents prefer the combination of open decompression and IPD (64.4%; n = 87). A total of 9.6% (n = 13) of the users favor IPD implantation as a stand-alone procedure. Overall, 25.9%  n = 35  use both options. Most surgeons aim to relieve the facet joints (87.7%) and to stabilize a preexisting instability (75.4%). They recommend IPDs in the segments L2-L3 (77%), L3-L4 (98.5%), and L4-l5 (99.3%) and consider that IPD implanation also could be done at the L5-S1 segment (40.1%). Overall, 64.4% (n = 87) of the users recommend limiting IPD implantation to two segments. Infection (96.3%), fracture (94.8%), isthmic spondylolisthesis (77%), degenerative spondylolisthesis (higher than Meyerding I [57%]), lumbar spine scoliosis (48.1%), and osteoporosis (50.4%) are seen as contraindications for IPD. CONCLUSION No clear consensus exists among spine surgeons concerning the use of IPD for LSS treatment. The study showed that hospital-related parameters also influence decision making for or against the use of IPDs. However, despite the lack of evidence, the indications and contraindications which had been identified in the present study might contribute to improved outcomes after IPD implantation or at least prevent harm to patients.

Biomechanical comparison of transosseous re-fixation of the deep fibres of the distal radioulnar ligaments versus deep and superficial fibres: a cadaver study

PurposeWe hypothesized that the re-fixation of the deep and superficial fibres of the distal radioulnar ligaments provide improved stability compared to reconstruction of the deep fibres alone.MethodsFourteen fresh-frozen cadaver upper extremities were used for biomechanical testing. Transosseous re-fixation of the deep fibres of the distal radioulnar ligaments alone (single mattress suture group; n = 7) was compared to the transosseous re-attachment of the deep and superficial fibres (double mattress suture group; n = 7). Cyclic load application provoked palmar translation of the radius with respect to the rigidly affixed ulna. Creep, stiffness, and hysteresis were obtained from the load-deformation curves, respectively. Testing was done in neutral forearm rotation, 60° pronation, and 60° supination.ResultsThe re-fixation techniques did not differ significantly regarding the viscoelastic parameters creep, hysteresis, and stiffness. Several significant differences of one cycle to the consecutive one within each re-fixation group could be detected especially for creep and hysteresis. No significant differences between the different forearm positions could be detected for each viscoelastic parameter.ConclusionsThe re-fixation techniques did not differ significantly regarding creep, hysteresis, and stiffness. This means that the additional re-attachment of the superficial fibres may not provide greater stability to the DRUJ. Bearing in mind that the study was a cadaver examination with a limited number of specimens we may suppose that the re-attachment of the superficial fibres seem to be unnecessary. A gradual decline of creep and hysteresis from first to last loading-unloading cycle is to be expected and typical of ligaments which are viscoelastic.

Anterior Spinal Artery Syndrome: Reversible Paraplegia after Minimally Invasive Spine Surgery

Background Context. Percutaneous balloon kyphoplasty is an established minimally invasive technique to treat painful vertebral compression fractures, especially in the context of osteoporosis with a minor complication rate. Purpose. To describe the heparin anticoagulation treatment of paraplegia following balloon kyphoplasty. Study Design. We report the first case of an anterior spinal artery syndrome with a postoperative reversible paraplegia following a minimally invasive spine surgery (balloon kyphoplasty) without cement leakage. Methods. A 75-year-old female patient underwent balloon kyphoplasty for a fresh fracture of the first vertebra. Results. Postoperatively, the patient developed an acute anterior spinal artery syndrome with motor paraplegia of the lower extremities as well as loss of pain and temperature sensation with retained proprioception and vibratory sensation. Complete recovery occurred six hours after bolus therapy with 15.000 IU low-molecular heparin. Conclusion. Spine surgeons should consider vascular complications in patients with incomplete spinal cord syndromes after balloon kyphoplasty, not only after more invasive spine surgery. High-dose low-molecular heparin might help to reperfuse the Adamkiewicz artery.

Effect of prolonged-released oxycodone/naloxone in postoperative pain management after total knee replacement: a nonrandomized prospective trial

PURPOSE The purpose of this study was to examine the effect of postoperative prolonged release oxycodone/naloxone (OXN) in comparison to other opioids (control group) on the early postoperative rehabilitation outcome after total knee replacement. METHODS In a prospective, noninterventional, nonrandomized clinical trial, 80 patients were assigned to either the OXN group or a control group. Postoperative outcome and pain level at days 3, 6, 21, 35, and 6months were evaluated using the Bowel Function Index, Brief Pain Inventory Short Form questionnaire, the Hospital for Special Surgery score, modified Larson score, and the ability to attend physiotherapy. Medications were recorded and safety analysis was done. Both groups were compared using an analysis of covariance. RESULTS There were no significant differences between both groups regarding pain levels. OXN group patients reported better bowel function (median values of 0.0 for the OXN group and 20.0 for the control group). No effect of treatment group (P=.19) and no treatment-by-visit interaction on Hospital for Special Surgery final score (P=.67) could be detected, but Larson function score in the early postoperative phase was significantly better in the OXN group (P=.018). The proportion of OXN group patients who were able to attend without any restriction was 58.1%. The proportions of patients in the OXN group and control group who experienced mild or moderate adverse drug reactions were 23.3% and 37.8%, respectively. There were no serious adverse drug reactions. CONCLUSION In conclusion, OXN provides an effective analgesia and offers several benefits such as higher ability to participate in physiotherapy and better functional results. Incidence and severity of constipation can be reduced by using prolonged-released OXN as compared with other opioids.