Ivan Marintschev

Screw placement for acetabular fractures: which navigation modality (2-dimensional vs. 3-dimensional) should be used? An experimental study.

Objectives: Screw navigation techniques with different image guidance [2-dimensional (2D) vs. 3-dimensional (3D) fluoroscopy] were evaluated for acetabular fracture surgery. Methods: Two-dimensional and 3D navigation images were analyzed for visualization of different osseous corridors: supra-acetabular, anterior column, posterior column, and infra-acetabular. Forty guide wires per group were placed in synthetic pelvis with a prefabricated soft tissue envelope (10 per group) using a 2D or 3D fluoroscopic navigation procedure. Duration of the single steps for each procedure and of cumulative fluoroscopy time was measured. The accuracy of guide wire placement was evaluated visually and in 3D cone-beam scans. Results: The overall procedure time per pelvis was significantly reduced in the 3D group compared with the 2D group [mean ± standard error (SE) (minutes): 50.11 ± 1.38 vs. 63.42 ± 2.32; P < 0.0001]. A trend to reduction in image acquisition time [mean ± SE (minutes): 12.37 ± 1.34 vs. 15.43 ± 1.03; P = not significant] and significant increase in the cumulative fluoroscopy time [mean ± SE (seconds): 64 ± 9 vs. 13 ± 1.3; P < 0.0001) was measured in the 3D compared with the 2D group, caused by the 3D scan. Intra-articular misplacements were not observed in both the groups, but an increased accuracy could be achieved using the 3D image–based navigation procedure (perfect placement: 37 vs. 29; secure placement: 2 vs. 7; misplacement: 1 vs. 4). Conclusions: Both navigation procedures securely prevent an intra-articular penetration during drilling, but the 3D image–based navigation procedure increases the overall accuracy compared with the 2D image–based navigation technique (misplacement rates of 2.5% vs. 10%). Especially, in very narrow corridors (as the infra-acetabular screw path), the use of 3D navigation should be preferred.

Arthroscopic-Controlled Navigation for Retrograde Drilling of Osteochondral Lesions of the Talus

Background: Retrograde drilling of symptomatic osteochondral lesions (OCL) is usually controlled by fluoroscopy. Due to the limited visualization of the OCLs in the acquired images and the narrow access to the talar dome, this approach can be demanding. Several navigation procedures have been reported (2D- or 3D- fluoroscopy or intraoperative CT-based) to increase the accuracy and reduce the radiation exposure. We developed a new arthroscopic-controlled navigation procedure which is free of radiation exposure and free of a reference base rigidly fixed to the bone. 17 We hypothesized that this procedure (Fluoro-Free) is at least as precise as the standard 2D-Fluoro navigation (2D-Fluoro). Furthermore, our first clinical experiences are described and discussed. Material and Methods: Sixteen drillings per group (standard 2D-Fluoro vs. Fluoro-Free) were performed in artificial sawbones. Times for the different steps of each drilling procedure were recorded and the precision evaluated by measuring the deviation and depth of drilling. Results: The accuracy of the Fluoro-Free navigation was as precise as the standard 2D-Fluoro based navigation (axis deviation of drill tip to the target point: 1.07 ± 0.11 versus 1.14 ± 0.15 mm). Due to the simplified workflow without radiation exposure and fixation of a reference base, the Fluoro-Free procedure was significantly faster (mean procedure time per drilling: 23.7 ± 11.6 versus 165 ± 9 seconds) and easy to use. Its clinical usefulness was demonstrated during three retrograde drillings of a talar OCL in a 16-year-old patient. Conclusion: The Fluoro-Free navigation procedure is a simplified approach for retrograde drilling of OCL in the talus under arthroscopic control without radiation exposure and without the need for fixation of a dynamic reference base to the bone. Level of Evidence: V, Expert Opinion

Screw- versus plate-fixation strength of acetabular anterior column fractures: a biomechanical study.

BACKGROUND The standard for operative treatment of acetabular fractures is open reduction and plate fixation. Recently, screw fixation-only methods through less invasive approaches are reported, but biomechanical data are missing. Questions posed in this study are (1) is the static fixation strength of different screw types equivalent to the standard plate fixation for anterior column fractures of the acetabulum? and (2) does the placement of an additional screw in the infra-acetabular corridor increase the fixation strength independent of the used implant? METHODS Three groups of different screws (group II, titanium; group III, stainless steel; and group IV, biodegradable Poly-l-Lactid) were compared with the standard plate fixation (group I) in Synbone pelves with custom-made anterior column fractures. Six pelvises per group were axial loaded with six cycles of 800 N, twice with and without an additional placed infra-acetabular screw. RESULTS The fixation strength of titanium screws was equivalent to the standard plate fixation. The stainless steel and Poly-l-Lactid screw fixation strengths were equivalent to each other but inferior to the aforementioned. The additional placement of an infra-acetabular screw significantly increased the fracture fixation strength, independent of the used implant. CONCLUSION Screw fixation is a promising alternative approach for the stabilization of noncomminuted acetabular fractures of the anterior column with equivalent fixation strength to the standard plate fixation. The additional placement of an infra-acetabular screw significantly increases the fracture fixation independent of the used implant and should be considered for acetabular fractures with separation of both columns. LEVEL OF EVIDENCE Therapeutic study, level IV.

Differenzialtherapie der Radiusköpfchenfraktur in Abhängigkeit vom Frakturtyp

Hinsichtlich des Therapieregimes von Radiusköpfchenfrakturen, insbesondere bei dislozierten Bruchformen und Trümmerfrakturen, bestehen deutlich divergierende, teilweise kontroverse Auffassungen. In den letzten Jahren wurde insbesondere die Radiusköpfchenresektion einer kritischen Betrachtung unterzogen. Von 1984–1993 sowie 1996–1999 wurden in unserer Klinik 105 ¶Radiusköpfchenfrakturen stationär behandelt, von denen 74 klinisch und radiologisch nachuntersucht wurden. Zur Frakturtypbestimmung fand die Klassifikation nach Mason Anwendung. Nichtdislozierte Frakturen wurden konservativ, dislozierte 2-Fragment-Frakturen durch eine offene Reposition und Verschraubung, und Mehrfragmentfrakturen durch eine Radiusköpfchenresektion behandelt. Zur Beurteilung der Ergebnisse wurden der Functional-rating-Index nach Broberg u. Morrey und der radiologische Score nach Albrecht u. Ganz verwendet. Nach konservativer Therapie resultierten > 80% ausgezeichnete und gute sowie 12,5% befriedigende und 6,3% schlechte Ergebnisse. Nach Reposition und Osteosynthese waren wiederum 80% ausgezeichnete und gute Resultate zu verzeichnen. Nach Radiusköpfchenresektion wurden in 54,6% der Fälle ausgezeichnete und gute, in 24,2% befriedigende und in 21,2% schlechte Ergebnisse erzielt, wobei in dieser Gruppe der Anteil prognosebeeinflussender, schwerer Begleitverletzungen besonders groß war. Bei entsprechender Indikation und Technik ist die Radiusköpfchenresektion nach wie vor ein empfehlenswertes Behandlungsverfahren mit insgesamt guter Prognose. Das gilt insbesondere für die isolierten Speichenköpfchenbrüche mit etwa 70% ausgezeichneten und guten Ergebnissen.There are diverging, and in part controversial, views on the best therapy regimen for radial head fractures, especially of the displaced and comminuted types. Radial head resection has been critically reviewed in recent years. In the periods 1984–1993 and 1996–1999 patients with a total of 105 radial head fractures were treated in the hospital as in-patients, and clinical and radiological follow-up was possible for 74 of these fractures. The fracture types were classified according to Mason’s system. Undisplaced fractures were treated conservatively, displaced 2-fragment fractures by open reduction and screw fixation, and multifragment fractures by a radial head resection. The results have been studied with reference to function and radiological appearance using the „Functional Rating Index“ of Broberg and Morrey and the radiological score of Albrecht and Ganz. After conservative therapy the results were excellent or good in over 80% of cases, satisfactory in 12.5% and poor in 6.3%. After reduction and internal fixation, again 80% had excellent and good results. After radial head resection excellent and good results were achieved in 54.6% of the cases, satisfactory in 24.2%, and poor in 21.2%, but there was a particularly high proportion of patients with severe accompanying injuries affecting the prognosis in this group. With the correct indications and technique, radial head resection is a treatment procedure that can still be recommended and has good overall prospects of success. This is especially true in the case of isolated radial head fracture, in which it yields excellent or good results in approximately 70% of cases.

Radiation- and reference base-free navigation procedure for placement of instruments and implants: Application to retrograde drilling of osteochondral lesions of the knee joint

Objective: A novel, radiation- and reference base-free procedure for placement of navigated instruments and implants was developed and its practicability and precision in retrograde drillings evaluated in an experimental setting. Materials and Methods: Two different guidance techniques were used: One experimental group was operated on using the radiation- and reference base-free navigation technique (Fluoro Free), and the control group was operated on using standard fluoroscopy for guidance. For each group, 12 core decompressions were simulated by retrograde drillings in different artificial femurs following arthroscopic determination of the osteochondral lesions. The final guide-wire position was evaluated by postoperative CT analysis using vector calculation. Results: High precision was achieved in both groups, but operating time was significantly reduced in the navigated group as compared to the control group. This was due to a 100% first-pass accuracy of drilling in the navigated group; in the control group a mean of 2.5 correction maneuvers per drilling were necessary. Additionally, the procedure was free of radiation in the navigated group, whereas 17.2 seconds of radiation exposure time were measured in the fluoroscopy-guided group. Conclusion: The developed Fluoro Free procedure is a promising and simplified approach to navigating different instruments as well as implants in relation to visually or tactilely placed pointers or objects without the need for radiation exposure or invasive fixation of a dynamic reference base in the bone.

Pain sensation in human osteoarthritic knee joints is strongly enhanced by diabetes mellitus

Abstract The major burden of knee joint osteoarthritis (OA) is pain. Since in elder patients diabetes mellitus is an important comorbidity of OA, we explored whether the presence of diabetes mellitus has a significant influence on pain intensity at the end stage of knee OA, and we aimed to identify factors possibly related to changes of pain intensity in diabetic patients. In 23 diabetic and 47 nondiabetic patients with OA undergoing total knee arthroplasty, we assessed the pain intensity before the operation using the “Knee Injury and Osteoarthritis Outcome Score”. Furthermore, synovial tissue, synovial fluid (SF), cartilage, and blood were obtained. We determined the synovitis score, the concentrations of prostaglandin E2 and interleukin-6 (IL-6) in the SF and serum, and of C-reactive protein and HbA1c and other metabolic parameters in the serum. We performed multivariate regression analyses to study the association of pain with several parameters. Diabetic patients had on average a higher Knee Injury and Osteoarthritis Outcome Score pain score than nondiabetic patients (P < 0.001). Knee joints from diabetic patients exhibited on average higher synovitis scores (P = 0.024) and higher concentrations of IL-6 in the SF (P = 0.003) than knee joints from nondiabetic patients. Multivariate regression analysis showed that patients with higher synovitis scores had more intense pain independent of all investigated confounders, and that the positive association between pain intensities and IL-6 levels was dependent on diabetes mellitus and/or synovitis. These data suggest that diabetes mellitus significantly increases pain intensity of knee OA, and that in diabetic patients higher pain intensities were determined by stronger synovitis.

Achillessehnenrupturen und -durchtrennungen

ZusammenfassungDie Anzahl der Achillessehnenrupturen nimmt mit zunehmendem Freizeit- und Breitensport zu. Die häufigste Rissstelle liegt 2–6 cm oberhalb des Sehnenansatzes. Die Diagnose kann nach Anamnese, klinischem Befund und ergänzender Sonographie sicher gestellt werden. In den letzten 10 Jahren hat die Möglichkeit der sonographischen Darstellung und Kontrolle im Verlauf die Therapiewahl zunehmend beeinflusst. Bei adaptierbaren Sehnenenden in 20° Plantarflexion kann die Verletzung konservativ mit der operativen Therapie analogen Langzeitergebnissen zur Ausheilung gebracht werden. Die Standardtherapiemethode der frischen Achillessehnenruptur ist die offen-chirurgische Naht (Fragebogen in 8 BG-Kliniken: 90% der Fälle). Der Anteil konservativ-funktionell behandelter Patienten schwankte zwischen 0 und 20%. In einer BG-Klinik wurden 10% der Fälle durch offene Klebung versorgt. Die perkutane Tenodese wurde in einer Klinik in 5% der Fälle angewendet. Die Begutachtung von Achillessehnenrupturen und deren Folgen ist durch degenerative Veränderungen erschwert. Zur Beurteilung werden der genaue Unfallmechanismus und der histologische Befund vom Sehnenrissrand herangezogen.AbstractThe number of Achilles tendon ruptures has risen as people have engaged in increasingly more leisure and group sporting activities. It most frequently tears 2–6 cm above its insertion. The history, clinical findings and ultrasound examination allow a reliable diagnosis. The availability of ultrasonographic imaging and controls in the course of recovery have influenced decisions on therapy increasingly in the last 10 years. When tendon ends are coapted in 20° plantar flexion, a conservative-functional treatment can be applied with a long-term outcome comparable to that of operative treatment. The standard method of treatment for a fresh Achilles tendon rupture is open surgical suture (used in 90% of cases according to a questionnaire survey conducted in 8 BG-Hospitals). The proportion of patients who undergo conservative-functional treatment fluctuates between 0 and 20%. In one BG hospital the tendon is repaired by surgical glueing ¶in 10% of cases. In another, percutaneous tenodesis is applied in 5% of cases. Legally binding expert assessment of Achilles tendon tears and their sequelae is made more difficult by degenerative tissue changes. The exact mechanism of the accident and the histological findings at the torn end of the tendon are taken into account in the judgment.

Aktueller Stand der Therapie distaler Humerusfrakturen des Erwachsenen

Die Behandlungsstrategie bei distalen Humerusfrakturen ist allgemein akzeptiert und hat sich in den letzten 15 Jahren nicht wesentlich verändert. Das erklärte Ziel bleiben eine anatomische Reposition und stabile Osteosynthese mit frühfunktioneller Nachbehandlung. Bei kompletten intraartikulären Frakturen ist der Zugang über eine Olekranonosteotomie notwendig. Unsere eigenen Ergebnisse mit nur 63% guten und sehr guten Resultaten nach B- und C-Verletzungen (34 Patienten) sind nicht befriedigend. Trotz weltweit anerkannter standardisierter Operationstechnik stellt die Verbesserung der klinischen Resultate eine bleibende Herausforderung dar und ist bei zurzeit fehlenden Neuerungen in der operativen Technik u.u2002a. nur durch die Vermeidung individueller Fehler zu erreichen.There are not many fracture locations for which there is a greater degree of consensus on treatment regimens in the world than there are for the distal end of the humerus. The declared aim is anatomic reduction and stable internal fixation with early functional aftercare. Olecranon osteotomy is essential for access in the management of complete intra-articular fractures. Despite the standardized principles of surgical technique good clinical results are still elusive. Among 34 patients with an intra-articular fracture treated operatively good or excellent results were achieved in only 63%. The lack of new therapeutic strategies probably means that the surgeon’s skills are more important than in the treatment of fractures at other locations.

Tangential View and Intraoperative Three-Dimensional Fluoroscopy for the Detection of Screw-Misplacements in Volar Plating of Distal Radius Fractures

Background: Volar locking plate fixation has become the gold standard in the treatment of unstable distal radius fractures. Juxta-articular screws should be placed as close as possible to the subchondral zone, in an optimized length to buttress the articular surface and address the contralateral cortical bone. On the other hand, intra-articular screw misplacements will promote osteoarthritis, while the penetration of the contralateral bone surface may result in tendon irritations and ruptures. The intraoperative control of fracture reduction and implant positioning is limited in the common postero-anterior and true lateral two-dimensional (2D)-fluoroscopic views. Therefore, additional 2D-fluoroscopic views in different projections and intraoperative three-dimensional (3D) fluoroscopy were recently reported. Nevertheless, their utility has issued controversies. Objectives: The following questions should be answered in this study; 1) Are the additional tangential view and the intraoperative 3D fluoroscopy useful in the clinical routine to detect persistent fracture dislocations and screw misplacements, to prevent revision surgery? 2) Which is the most dangerous plate hole for screw misplacement? Patients and Methods: A total of 48 patients (36 females and 13 males) with 49 unstable distal radius fractures (22 x 23 A; 2 x 23 B, and 25 x 23 C) were treated with a 2.4 mm variable angle LCP Two-Column volar distal radius plate (Synthes GmbH, Oberdorf, Switzerland) during a 10-month period. After final fixation, according to the manufactures technique guide and control of implant placement in the two common perpendicular 2D-fluoroscopic images (postero-anterior and true lateral), an additional tangential view and intraoperative 3D fluoroscopic scan were performed to control the anatomic fracture reduction and screw placements. Intraoperative revision rates due to screw misplacements (intra-articular or overlength) were evaluated. Additionally, the number of surgeons, time and radiation-exposure, for each step of the operating procedure, were recorded. Results: In the standard 2D-fluoroscopic views (postero-anterior and true lateral projection), 22 screw misplacements of 232 inserted screws were not detected. Based on the additional tangential view, 12 screws were exchanged, followed by further 10 screws after performing the 3D fluoroscopic scan. The most lateral screw position had the highest risk for screw misplacement (accounting for 45.5% of all exchanged screws). The mean number of images for the tangential view was 3 ± 2.5 images. The mean surgical time was extended by 10.02 ± 3.82 minutes for the 3D fluoroscopic scan. An additional radiation exposure of 4.4 ± 4.5seconds, with a dose area product of 39.2 ± 14.5 cGy/cm2 were necessary for the tangential view and 54.4 ± 20.9 seconds with a dose area product of 2.1 ± 2.2 cGy/cm2, for the 3D fluoroscopic scan. Conclusions: We recommend the additional 2D-fluoroscopic tangential view for detection of screw misplacements caused by overlength, with penetration on the dorsal cortical surface of the distal radius, predominantly observed for the most lateral screw position. The use of intraoperative 3D fluoroscopy did not become accepted in our clinical routine, due to the technical demanding and time consuming procedure, with a limited image quality so far.

Komplexverletzungen des Fußes

ZusammenfassungKomplexverletzungen des Fußes werden v.xa0a. bei polytraumatisierten Patienten häufig übersehen und führen dann zu bleibenden schwerwiegenden Funktionsverlusten. Beim Vorliegen eines entsprechenden Unfallmechanismus sollte daher der Fuß in die Primärdiagnostik einbezogen und initial eine klinische, nach Stabilisierung auch röntgenologische Diagnostik erfolgen. Bei komplexen Fußverletzungen wird die Prognose von der Weichteilsituation bestimmt. Die diagnostischen Maßnahmen sollten der Priorität der Gesamtverletzungsschwere angepasst werden. Eine erfolgreiche Therapie beinhaltet stabile Osteosynthesetechniken der knöchernen und artikulären Läsionen unter Berücksichtigung initialer externer Stabilisierungsmöglichkeiten sowie differenzierte Methoden der temporären und definitiven Weichteilrekonstruktion. Das Behandlungsziel ist die bestmögliche Wiederherstellung des Fußes als tragfähige bewegliche Funktionseinheit mit einem intakten Weichteilmantel und natürlicher Form. Gute Ergebnisse können unter enger interdisziplinärer Zusammenarbeit zwischen Unfallchirurgen und Plastischen Chirurgen erreicht werden. Patienten mit derart schweren Verletzungen sollten primär einem entsprechenden Traumazentrum zugeführt werden.AbstractComplex injuries of the foot are often overlooked, especially in the multiple injured patient, and they then lead to major loss of function. When the mechanism of injury suggests involvement of the foot, a clinical examination of the lower extremities should be included in the primary diagnostic procedures implemented in the multiply injured patient, followed by radiological examination once the patients condition is stable. The condition of the soft tissues is of decisive importance in the prognosis of complex foot injuries, regardless of whether the damage to the foot is one component of a polytrauma or an isolated injury, which can also be life threatening. The diagnostic examinations selected should be adapted to the severity of the injuries in the particular multiply injured patient. Successful therapy involves stable internal fixation of injuries to bones and joints, though the external fixation options should be considered in the first instance, and carefully selected methods of temporary and definitive soft tissue reconstruction. The aim of treatment is the best possible reconstruction of the foot as a functional weight-bearing unit with intact soft tissue cover and a natural form. Good results can be achieved when there is close interdisciplinary cooperation between trauma (orthopedic) and plastic surgeons. Patient with severe injuries of this kind should be transferred to a trauma center as the first step toward this end.