Clemens Dumont

Impact of the Method of Initial Stabilization for Femoral Shaft Fractures in Patients With Multiple Injuries at Risk for Complications (Borderline Patients)

Objectives:The timing of definitive fixation for major fractures in patients with multiple injuries is controversial. To address this gap, we randomized patients with blunt multiple injuries to either initial definitive stabilization of the femur shaft with an intramedullary nail or an external fixateur with later conversion to an intermedullary nail and documented the postoperative clinical condition. Methods:Multiply injured patients with femoral shaft fractures were randomized to either initial (<24 hours) intramedullary femoral nailing or external fixation and later conversion to an intramedullary nail. Inclusion: New Injury Severity Score >16 points, or 3 fractures and Abbreviated Injury Scale score ≥2 points and another injury (Abbreviated Injury Scale score ≥2 points), and age 18 to 65 years. Exclusion: patients in unstable or critical condition. Patients were graded as stable or borderline (increased risk of systemic complications). Outcomes:Incidence of acute lung injuries. Results:Ten European Centers, 165 patients, mean age 32.7 ± 11.7 years. Group intramedullary nailing, n = 94; group external fixation, n = 71. Preoperatively, 121 patients were stable and 44 patients were in borderline condition. After adjusting for differences in initial injury severity between the 2 treatment groups, the odds of developing acute lung injury were 6.69 times greater in borderline patients who underwent intramedullary nailing in comparison with those who underwent external fixation, P < 0.05. Conclusion:Intramedullary stabilization of the femur fracture can affect the outcome in patients with multiple injuries. In stable patients, primary femoral nailing is associated with shorter ventilation time. In borderline patients, it is associated with a higher incidence of lung dysfunctions when compared with those who underwent external fixation and later conversion to intermedullary nail. Therefore, the preoperative condition should be when deciding on the type of initial fixation to perform in patients with multiple blunt injuries.

Prognostic reliability of the Hawkins sign in fractures of the talus.

Objective: To determine the prognostic reliability, sensitivity, and specificity of the Hawkins sign. The Hawkins sign is a subchondral radiolucent band in the talar dome that is indicative of viability at 6 to 8 weeks after a talus fracture. It is visible in the anterior-posterior view, but seldom appears on lateral radiographs. Design: Retrospective study. Setting: University hospital. Patients and Methods: Between January 1995 and December 2000, a total of 41 patients (13 female, 28 male) with displaced talar fractures were operated on in our hospital. Thirty-four patients with a mean age of 35 years (range 12-60) were followed for more than 36 months (range 36-52). The prognostic reliability of the Hawkins sign was studied in 31 of these patients using a two-by-two table. The Ankle-Hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS) was used as an outcome measure. Results: No Hawkins sign was found in the five patients who developed avascular necrosis (AVN) of the talus. In the remaining 26 patients who did not develop AVN, a positive (full) Hawkins sign was observed 11 times, a partially positive Hawkins sign 4 times, and a negative Hawkins sign 11 times. The Hawkins sign thus showed a sensitivity of 100% and a specificity of 57.7%. The Hawkins sign (if present) appeared between the 6th and the 9th week after trauma. Mean [range] AOFAS scores were: Pain, 31 [10-40] out of 40; Function, 39 [14-50] out of 50; and Alignment, 7 [0-10] out of 10. The clinical results were satisfactory. Conclusion: The Hawkins sign is a good indicator of talus vascularity following fracture. If a full or partial positive Hawkins sign is detected, it is unlikely that AVN will develop at a later stage after injury.

Morphology of the Interphalangeal Joint Surface and Its Functional Relevance

PURPOSE To study and to clarify the curvature morphology of the articular surfaces of the proximal interphalangeal (PIP) joint and to relate joint morphology and joint kinematics. METHODS The radii and centers of curvature of 40 PIP joints were determined by sagittal and transverse intersections of highly precise replicas that were prepared by dental methods. RESULTS The PIP joint is proved to be a nonconforming joint: the articular surface of the proximal end of the middle phalanx has lesser curvatures than the condyles of the proximal phalanx. In intersections through the apex of the radial and ulnar condyles, the measured differences of the radii between the articular surfaces of the PIP joint were sagittally about 30% and transversely about 49% of the respective radii of the condyles. Incongruity of the joint results in 2 morphologically given axes for extension respective to flexion: (1) an axis given by the articular surfaces of both condyles of the proximal phalanx; and (2) a second axis given by the articular surface of the proximal end of the middle phalanx. Both articulating surfaces have 2 contact points in the transverse plane, one each, central to the apex of radial and ulnar condyles, respectively. In the middle of the joint, in the intercondylar groove, a small joint cavity was present in 37 of 40 joints. CONCLUSIONS The physiological incongruity of the 2 articular surfaces of the PIP joint was defined quantitatively. This allows the derivation of a theoretical model for PIP joint function that explains the kinematics and mechanical stability of the joint as well as the lubrication and nutrition of the cartilaginous structures.

How do spinal segments move

PURPOSE To study and clarify the kinematics of spinal segments following cyclic torques causing axial rotation (T(z) (t)), lateral-flexion (T(x) (t)), flexion/extension (T(y) (t)). METHODS A 6D--Measurement of location, alignment, and migration of the instantaneous helical axis (IHA) as a function of rotational angle in cervical, thoracic, and lumbar segments subjected to axially directed preloads. RESULTS IHA retained an almost constant alignment, but migrated along distinct centrodes. THORACIC SEGMENTS: IHA was almost parallel to T(z) (t), T(x) (t), or T(y) (t), stationary for T(x) (t) or T(y) (t), and migrating for T(z) (t) along dorsally opened bows. IHA locations hardly depended on the position or size of axial preload. LUMBAR SEGMENTS: IHA was also almost parallel to T(z) (t), T(x) (t), or T(y) (t). In axial rotation IHA-migration along wide, ventrally or dorsally bent bows depending on segmental flexional/extensional status. Distances covered: 20-60mm. In lateral-flexion: IHA-migration to the left/right joint and vice versa. In flexion/extension IHA-migration from the facets to the centre of the disc. CERVICAL SEGMENTS: In flexion/flexion IHA was almost stationary for and parallel to T(y) (t). In axial rotation or lateral-flexion IHA intersected T(z) (t)/T(x) (t) under approximately -30 degrees /+30 degrees. CONCLUSIONS Generally joints alternate in guidance. Lumbar segments: in axial rotation and lateral-flexion parametrical control of IHA-position and IHA-migration by axial preload position. Cervical segments: kinematical coupling between axial rotation and lateral-flexion. The IHA-migration guided by the joints should be taken into account in the design of non-fusion implants. FE-calculations of spinal mechanics and kinematics should be based on detailed data of curvature morphology of the articulating surfaces of the joint facets.

Refixation osteochondraler Fragmente mit resorbierbaren Implantaten

AbstractAn osteochondral lesion in a weight bearing joint causes therapeutic problems. Surgical therapy focuses on the restoration of the articular surface, unlimited motion of the joint and prevention of cartilaginous degeneration. A causal therapy to prevent posttraumatic osteoarthritis is the fixation of osteochondral fragments. Various absorbable implants for the purpose of refixation are available, but only a few have proved to be biocompatible. This retrospective study presents the preliminary results after refixation of osteochondral fragments of the ankle and knee joints. We used self-reinforced absorbable pins, nails and screws made of polylactide acid. The results for 15 patients with 17 fractures of 16 joints were evaluated. All patients were scored by the Tegner-activity-level, the McDermott-score and the DGKKT-score, and 13 of them were monitored by postoperative magnetic resonance imaging (MRI). The follow-up extended for an average of 14.3 months (range: 4-43 months). The clinical results for all patients were good (McDermott-score: Ø 89 points, DGKKT-score: Ø 78.8 points, Tegner: pre-op vs post-op=Ø 4.6 vs Ø 5.1) and the surgical therapy proved to be successful. The MRI showed the complete incorporation and vitality of the fragment as well as a congruence of the joint surface. The clinical course and the MRI gave little reference to an inflammatory reaction due to the implants that complicated the course of two patients. These results indicate that absorbable implants made of polylactide acid are biocompatible and effective in the fixation of osteochondral fragments. ZusammenfassungEin osteochondraler Schaden in der Belastungszone eines Gelenkes ist weiterhin ein therapeutisches Problem. Das Ziel der Therapie ist die Wiederherstellung der Knorpeloberfläche mit normaler Gelenkfunktion, freier schmerzloser Beweglichkeit und Verhinderung einer weiteren Knorpeldegeneration. Dies lässt sich vielfach dadurch erreichen, dass osteochondrale Fragmente refixiert werden. Hierfür stehen resorbierbare Implantate aus verschiedenen Materialien zur Verfügung, die jedoch nicht alle gut biokompatibel sind. In der vorliegenden Arbeit werden die kurz- und mittelfristigen Ergebnisse einer retrospektiven Studie nach Fixation osteochondraler Frakturen traumatischer Genese an Knie- und Sprunggelenk dargestellt. Verwendet wurden Stifte, Nägel und Minischrauben aus “selbstverstärktem” Polylaktid. Fünfzehn Patienten mit 17 Frakturen an 16 Gelenken konnten wir nachuntersuchen und einer Scorebeurteilung unterziehen. Bei 13 Patienten erfolgte ergänzend eine Magnetresonnanztomographie. Die klinischen Ergebnisse im McDermott-Score (Ø 89 Pkt.), DGKKT-Score (Ø 78,8) und Tegner-Aktivitätsscore (Ø 4,6 vs. 5,1) waren bei einem durchschnittlichen Follow-up von 14,3 Monaten (4–43) gut, bestätigt durch eine vollständige Integration des vitalen Fragmentes mit Wiederherstellung der Oberflächenkongruenz in der MRT. Weder klinisch noch kernspintomographisch fanden sich ossär, extraartikulär und intraartikulär/synovial Hinweise auf lokale Fremdkörperreaktionen. Lediglich bei 2 Kniegelenken zeigte sich ein gering bis mäßig ausgeprägter Gelenkerguss bei den spät resorbierbaren Implantaten. Unseren Ergebnissen zufolge sind die verwendeten Implantate aus Polylaktid biokompatibel und effektiv für die Refixation osteochondraler Fragmente.

Refixation of osteochondral fragments using absorbable implants. First results of a retrospective study

AbstractAn osteochondral lesion in a weight bearing joint causes therapeutic problems. Surgical therapy focuses on the restoration of the articular surface, unlimited motion of the joint and prevention of cartilaginous degeneration. A causal therapy to prevent posttraumatic osteoarthritis is the fixation of osteochondral fragments. Various absorbable implants for the purpose of refixation are available, but only a few have proved to be biocompatible. This retrospective study presents the preliminary results after refixation of osteochondral fragments of the ankle and knee joints. We used self-reinforced absorbable pins, nails and screws made of polylactide acid. The results for 15 patients with 17 fractures of 16 joints were evaluated. All patients were scored by the Tegner-activity-level, the McDermott-score and the DGKKT-score, and 13 of them were monitored by postoperative magnetic resonance imaging (MRI). The follow-up extended for an average of 14.3 months (range: 4-43 months). The clinical results for all patients were good (McDermott-score: Ø 89 points, DGKKT-score: Ø 78.8 points, Tegner: pre-op vs post-op=Ø 4.6 vs Ø 5.1) and the surgical therapy proved to be successful. The MRI showed the complete incorporation and vitality of the fragment as well as a congruence of the joint surface. The clinical course and the MRI gave little reference to an inflammatory reaction due to the implants that complicated the course of two patients. These results indicate that absorbable implants made of polylactide acid are biocompatible and effective in the fixation of osteochondral fragments. ZusammenfassungEin osteochondraler Schaden in der Belastungszone eines Gelenkes ist weiterhin ein therapeutisches Problem. Das Ziel der Therapie ist die Wiederherstellung der Knorpeloberfläche mit normaler Gelenkfunktion, freier schmerzloser Beweglichkeit und Verhinderung einer weiteren Knorpeldegeneration. Dies lässt sich vielfach dadurch erreichen, dass osteochondrale Fragmente refixiert werden. Hierfür stehen resorbierbare Implantate aus verschiedenen Materialien zur Verfügung, die jedoch nicht alle gut biokompatibel sind. In der vorliegenden Arbeit werden die kurz- und mittelfristigen Ergebnisse einer retrospektiven Studie nach Fixation osteochondraler Frakturen traumatischer Genese an Knie- und Sprunggelenk dargestellt. Verwendet wurden Stifte, Nägel und Minischrauben aus “selbstverstärktem” Polylaktid. Fünfzehn Patienten mit 17 Frakturen an 16 Gelenken konnten wir nachuntersuchen und einer Scorebeurteilung unterziehen. Bei 13 Patienten erfolgte ergänzend eine Magnetresonnanztomographie. Die klinischen Ergebnisse im McDermott-Score (Ø 89 Pkt.), DGKKT-Score (Ø 78,8) und Tegner-Aktivitätsscore (Ø 4,6 vs. 5,1) waren bei einem durchschnittlichen Follow-up von 14,3 Monaten (4–43) gut, bestätigt durch eine vollständige Integration des vitalen Fragmentes mit Wiederherstellung der Oberflächenkongruenz in der MRT. Weder klinisch noch kernspintomographisch fanden sich ossär, extraartikulär und intraartikulär/synovial Hinweise auf lokale Fremdkörperreaktionen. Lediglich bei 2 Kniegelenken zeigte sich ein gering bis mäßig ausgeprägter Gelenkerguss bei den spät resorbierbaren Implantaten. Unseren Ergebnissen zufolge sind die verwendeten Implantate aus Polylaktid biokompatibel und effektiv für die Refixation osteochondraler Fragmente.

Long‐term effects of saw osteotomy versus random fracturing on bone healing and remodeling in a sheep tibia model

This article is about the evaluation of possible differences in biomechanical or histomorphological properties of bone healing between saw osteotomy and random fracturing after 6 months. A standardized, 30° oblique monocortical saw osteotomy of sheep tibia was carried out, followed by manual fracture completion of the opposed cortical bone. Fixation was performed by bridge plating (4.5 mm, LCDCP, broad). X‐rays were taken immediately after surgery and at the end of the study. Polychrome fluorescent staining was performed according to a standardized protocol in the 2nd, 4th 6th, 10th, 14th, 18th, 22th and 26th week. Ten sheep were comprehensively evaluated. Data for stiffness and histomorphology are reported. The average bending stiffness of the operated bone was higher (1.7 (SD 0.3) with plate (MP) vs. 1.5 without plate) than for the intact bone (1.4 (SD 0.2), though no significant differences in bending stiffness were observed (P>0.05). Fluorescence staining revealed small numbers of blood vessels and less fragment resorption and remodeling in the osteotomy gap. Bone healing after saw osteotomy shows a very close resemblance to ‘normal’ fracture healing. However, vascular density, fragment resorption, fragment remodeling, and callus remodeling are reduced at the osteotomy.

Cost analysis of Topical Negative Pressure (TNP) Therapy for traumatic acquired wounds.

Extended traumatic wounds require extended reconstructive operations and are accompanied by long hospitalizations and risks of infection, thrombosis and flap loss. In particular, the frequently used Topical Negative Pressure (TNP) Therapy is regarded as cost-intensive. The costs of TNP in the context of traumatic wounds is analyzed using the method of health economic evaluation. All patients (n=67: 45 male, 22 female; average age 54 y) with traumatically acquired wounds being treated with TNP at the university hospital of Goettingen in the period 01/01/2005–31/12/2007 comprise the basis for this analysis. The concept of activity-based costing based on clinical pathways according to InEK (National Institute for the Hospital Remuneration System) systematic calculations was chosen for cost accounting. In addition, a special module system adaptable for individual courses of disease was developed. The treated wounds were located on a lower extremity in 83.7% of cases (n=56) and on an upper extremity in 16.3% of cases (n=11). The average time of hospitalization of the patients was 54 days. Twenty-five patients (37.31%) exceeded the „maximum length of stay“ of their associated DRG (Diagnosis Related Groups). The total PCCL (patient clinical complexity level = patient severity score) of 2.99 reflects the seriousness of disease. For the treatment of the 67 patients, total costs were

Quantified Contours of Curvature in Female Index, Middle, Ring, and Small Metacarpophalangeal Joints

1,729,922.32 (1,249,176.91 €). The cost calculation showed a financial deficit of

The morphology of the articular surfaces of biological knee joints provides essential guidance for the construction of functional knee endoprostheses

–210,932.50 (–152,314.36 €). Within the entire treatment costs of