Heinz Gerngross

FUNCTIONAL EVALUATION OF THE 10-YEAR OUTCOME AFTER MODIFIED EVANS REPAIR FOR CHRONIC ANKLE INSTABILITY

The Evans tenodesis is an operative treatment for chronic ankle instability with good short-term results. 18,24,25 The disadvantage of impaired hind foot kinematics and restricted motion has been described, 6,16 and only few reports of long-term results can be found. 14 No techniques have been used to assess the outcome objectively. We wanted to determine whether a modified Evans procedure 33 led to a satisfactory clinical and functional outcome. Nineteen patients were available at a 10-year follow-up. The clinical examination included a detailed questionnaire and stress radiographs. Foot function was evaluated with plantar pressure distribution measurements during walking and peroneal reaction time measurements elicited on a rapidly tilting platform (recorded with surface electromyography). High subjective patient satisfaction was contrasted with a high rate of residual instability, pain, and swelling. The radiographs showed an increased number of exostoses. The gait analysis revealed reduced peak pressures under the lateral heel and increased values under the longitudinal arch. The reaction times of the peroneal muscles were shorter on the operated side (significant: peroneus longus). The persistent clinical problems as well as the functional changes indicate that the disturbed ankle joint kinematics permanently alter foot function and may subsequently support the development of arthrosis. Therefore, the Evans procedure should only be applied if anatomical reconstruction of the lateral ankle ligaments is not feasible.

Measurement of intracompartmental pressure with use of a new electronic transducer-tipped catheter system

Laboratory and clinical tests were carried out to determine the clinical usefulness, validity, and safety of a new self-calibrating, battery-powered monitoring system for the measurement of intramuscular pressure with use of an electronic transducer-tipped catheter. The eight probes accurately recorded applied pressures ranging from zero to 160 millimeters of mercury (zero to 21.33 kilopascals). The system registered little temperature-induced drift (maximum, 1.25 millimeters of mercury [0.17 kilopascal]) between dry room temperature and 40 degrees Celsius. There were also minimum variations (range, -0.14 to 0.81 millimeter of mercury [0.02 to 0.11 kilopascal]) in the pressures recorded during a twenty-four-hour period. The resting pressure in the tibialis anterior muscle of twenty volunteers who had normal limbs was a mean (and standard deviation) of 13.1+/-8.3 millimeters of mercury (1.75+/-1.11 kilopascals). There was a good correlation between externally applied pressures (zero, twenty, forty, sixty, eighty, and 100 millimeters of mercury [zero, 2.67, 5.33, 8.00, 10.66, and 13.33 kilopascals] applied with use of antishock trousers) and the pressures measured in the tibialis anterior muscle of four volunteers (r = 0.997 to 0.999). The injection of sterile saline solution into the tibialis anterior muscle of a volunteer and the use of high-frequency recording during muscular activity showed a high degree of responsiveness and sensitivity to changes in intramuscular pressure. We also prospectively evaluated the clinical usefulness of the system and found it to be easy to assemble, calibrate, and use. Thus, this reusable, electronic transducer-tipped catheter system, which is based on a noninfusion technique, is simple, minimally traumatic, and highly precise. It is free of hydrostatic pressure artifacts and provides dynamic responses to changes in intramuscular pressure.

Tenodesis versus carbon fiber repair of ankle ligaments : A clinical comparison

To compare the clinical and functional outcomes after using different reconstruction methods for chronic ankle instability, the authors followed 2 groups of patients after 69 and 72 months, respectively. Thirty patients (mean age, 28; range, 23-39 years) were treated with modified Evans tenodesis. Twenty-three patients (mean age, 32.2; range, 22-39 years) underwent total replacement of the lateral ankle ligaments by carbon fibers. The protocol of the retrospective study included a questionnaire, clinical examination, radiographic stress diagnostics, and gait analysis with use of the EMED-SF system. Dorsiflexion and inversion were significantly restricted after tenodesis in contrast to the carbon fiber replacement. Although radiographic stability was improved after surgery for both groups, progress of the arthrosis could not be stopped. After tenodesis, the measurement of plantar pressure distribution revealed a 20% increase of midfoot loading as compared with the opposite foot, whereas symmetrical loading of both feet was found after carbon fiber replacement. Additionally, the tenodesis feet had a significantly increased loading of the medial side of the foot. It was concluded that tenodesis and anatomic reconstruction of ankle ligaments lead to subjectively similar results. Foot function and range of motion, however, were less influenced after anatomic repair.

Intrakompartimentelle Druckmessung beim akuten Kompartmentsyndrom Ergebnisse einer Umfrage zu Indikation, Messtechnik und kritischem Druckwert

ZusammenfassungDer Stellenwert der intrakompartimentellen Gewebedruckmessung bei Verdacht auf ein akutes Kompartmentsyndrom und der kritische Grenzwert, ab dem die Fasziotomie indiziert ist, wird kontrovers diskutiert. Daher sollte das diagnostische Management beim akuten Kompartmentsyndrom im deutschsprachigen Raum untersucht werden. Hierfür wurde eine Umfrage im Rahmen der Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie im November 1997 durchgeführt. 420 Fragebögen konnten ausgewertet werden.Bei klinischem Verdacht auf ein akutes Kompartmentsyndrom führten 50,9% der Befragten (n=214) Kompartmentdruckmessungen durch. Dabei lag der Anteil derer, die zwar bei klinischem Verdacht Gewebedruckmessungen durchführten, den Ergebnissen jedoch nur einen geringen bis mäßigen Stellenwert zuordneten mit 43,7% (n=90) erstaunlich hoch. Im Gesamtkollektiv ordneten 61,8% (n=215) der Gewebedruckmessung einen geringen bis mäßigen Stellenwert zu.Bei den Messystemen kamen in der Mehrheit die Geräte Stryker® (63,1%, n=135) und Coach® (12,1%, n=26) zum Einsatz. Über die klinische Untersuchung und ggf. die Gewebedruckmessung hinaus setzten 175 (41,7%) der Befragten zusätzliche apparative Diagnostika ein. Die Indikation zur Fasziotomie wird von 110 (51.4%) der Messenden anhand eines fixen Druckwertes gestellt. Demgegenüber fließen bei 104 Chirurgen (48,6%) hämodynamische Parameter in die Entscheidung zur Fasziotomie mit ein.In der Gesamtsicht zeigte sich bei den Befragten im Hinblick auf das diagnostische Management beim akuten Kompartmentsyndrom eine extrem uneinheitliche Vorgehensweise. Die eingesetzten Messmethoden und der angegebene kritische Logendruck stimmte nur selten mit den gängigen Literaturempfehlungen überein.AbstractThe early diagnosis of acute compartment syndrome is very important, compartment monitoring is advocated. There is however still some controversy regarding the use of compartment pressure measurement devices in the diagnosis of acute compartment syndrome. We present the results of a survey that was designed to explore this issue in Germany.In the case of suspected acute compartment syndrome 50.9% (n=214) of the surgeons perform intracompartmental pressure measurement. Pressure measurement is of lower significance for 61.8% (n=215) surgeons questioned. Additional apparative diagnostics is performed by 41.7% of the surgeons. A large majority apply the Stryker® device (63.1%, n=135), followed by the Coach® device (12.1%, n=26). The pressure threshold for intervention is recommended by 51.4% (n=110) of the traumatologists as an absolute compartment pressure value. The remaining 48.6% (n=104) include haemodynamic parameters in their decision.The surgeons employ widely differing methods of approach in the diagnosis of acute compartment syndrome. Some of these are extremely different from the methods recommended in the literature.

Gait pattern analysis after ankle ligament reconstruction (modified Evans procedure).

We followed 38 patients with chronic ankle instability treated by a modified Evans procedure. Evaluation at an average of 68 months follow-up included a standard clinical questionnaire and examination, radiological procedures, and gait analysis. Plantar pressure distribution measurements were recorded during walking and were compared with data from a group of normal subjects (N = 100). The subjective patient questionnaire revealed 87% good or excellent results, but residual pain was reported by 40% of the patients. The gait analysis indicated a significant increase in midfoot loading (22%) consistent with an observed restriction of inversion after surgery. However, the plantar pressure changes were not associated with poor clinical outcome. We cannot say whether these increased pressures will be associated with long-term outcome.

Das akute Kompartmentsyndrom Ergebnisse einer klinisch-experimentellen Studie zu Druck- und Zeitgrenzwerten für die Notfallfasziotomie

ZusammenfassungProblemstellung: Das akute Kompartmentsyndrom der Extremitäten ist eine unfallchirurgische Notfallsituation. Einigkeit besteht darüber, dass nur eine frühzeitige operative Dekompression der betroffenen Muskelloge schwerwiegende Folgeschäden verhindern kann. Kontrovers wird jedoch der kritische Muskelgewebedruck diskutiert, ab dem ein derartiger Eingriff erfolgen soll. Humanstudien, die gleichzeitig den Gewebedruck und die Muskeloxygenation untersuchten, liegen bisher nicht vor. Daher sollte in einer Kompartmentsyndrom-Modellsituation der Gewebe-O2-Partialdruck und das Summenaktionspotential des N. peronaeus profundus analysiert werden. Methodik: Bei 22 normotensiven gesunden Freiwilligen wurden mit dem Beinsegment einer Antischockhose im M. tibialis anterior Druckwerte zwischen 0 und 100 mmHg erzeugt. Über einen Zeitraum von bis zu 6 h erfolgte die Messung des Gewebedrucks, der O2-Spannung (pO2) im M. tibialis anterior und elektromyographisch die Ableitung des Muskelsummenaktionspotenzials des N. peronaeus profundus. Ergebnisse:Übertragung des pneumatischen Drucks zu 97,7% (Q25%/Q75%: 89,2/99,8) auf den Extremitätenmuskel. Bereits bei niedrigen intramuskulären Druckwerten (30–40 mmHg) traten eine Hypoxie und Einschränkung des Muskelsummenaktionspotentials (MASP) auf. Eine Reduktion des MSAP auf Null und ein pO2 <1 mmHg war ab einem Druck von 50 mmHg zu beobachten. Gewebedruckwerte von über 75 mmHg resultierten nahezu ausnahmslos in einer Anoxie des Muskels. Schlussfolgerung: Selbst unter optimalen Perfusionsbedingungen führen bereits geringe Druckerhöhungen auf über 30 mmHg zur verminderten Gewebeoxygenation und Einschränkung der neuralen Funktion. Berücksichtigt werden muss, dass bei zusätzlich traumatisiertem Muskel die Ischämietoleranz des Gewebes erheblich vermindert und infolge zahlreicher, unbestimmbarer Einflussfaktoren (lokale Gefäßreaktivität, Autoregulation, Zentralisation) die lokale nutritive Perfusionssituation nicht sicher beurteilbar ist. Beim Patienten mit schwerem Weichteiltrauma sollte daher der aus Sicherheitsgründen niedrig gewählte absolute Druckwert von 30 mmHg als Grenze gelten.AbstractBackground: Acute compartment syndrome of the leg is to be regarded as a traumatological emergency. Most specialists already agree that only a timely operative decompression of the afflicted compartment can prevent serious tissue damage. What still remains subject to discussion, however, is the precise tissue pressure above which the operation becomes imperative. Experimental human studies focusingon tissue pressure and muscle oxygenation have not yet been carried out. It was thus the aim of the present study to analyze oxygen partial pressure of the anterior tibial muscle and peroneal action potential in a model compartment syndrome in man. Methods: In 22 healthy, normotensive volunteers, constant pressure values from 0 to 100 mmHg were induced in the anterior tibial muscle with antishock trousers. Over a period of up to 6 h measurements were made of (1) tissue pressure, (2) intramuscular oxygen partial pressure (pO2), and (3) muscle response potential (MRP) of the n. peroneus profundus by electroneurography. Results: We achieved a 97.7% (Q25%/Q75%: 89.2/99.8) transfer of the pneumatic pressure to the lower leg. Already at intramuscular tissue pressures of 30–40 mmHg, hypoxia and reduction of MRP appeared. A reduction of the MRP to zero and pO2 <1 mmHg was observed from a pressure of 50 mmHg. Tissue pressure values of over 75 mmHg resulted almost without exception in anoxia of the muscle. Conclusions: Even under normal perfusion conditions, already slight increases in pressure of above 30 mmHg lead to reduced tissue oxygenation and neural function. We have to consider that with additionally traumatized muscle the ischemic tolerance is markedly reduced and due to unknown influences such as local vasoreactivity and capacity of autoregulation the nutritive perfusion cannot be determined. In the case of a severely injured muscle, to be on the safe side decompressive fasciotomy should therefore be carried out if pressure values remain above 30 mmHg.

LONG-TERM RESULTS OF THE MODIFIED EVANS REPAIR FOR CHRONIC ANKLE INSTABILITY

We treated 19 patients for chronic ankle instability with a modified Evans procedure. All patients were evaluated after an average follow up of 128 months with detailed questionnaire, clinical examination, and stress radiographs. Although the subjective results were reported as 8 excellent, 7 good, and 4 fair, residual pain was reported by 11 patients. There was a significantly increased number of osteophytes in the treated ankle joint. Stress radiographs demonstrated significantly improved stability in the operated ankle joint. Range of motion was significantly reduced in hindfoot inversion. The results showed that the modified Evans procedure achieved sufficient joint stability at the expense of inversion range of motion. This reconstruction method apparently did not prevent the development of arthrosis.

The Challenge of Military Surgical Education

Now that field hospitals and rescue stations have been provided with state-of-the-art equipment, it is important to tailor the medical qualifications of military surgeons to the specific requirements of missions outside Germany. The objective of this article is to provide guidelines for a new training model. Einsatzchirurgie is defined as surgical treatment provided under restricted conditions in an unfamiliar environment. Its purpose is, first and foremost, to provide emergency treatment. The spectrum of Einsatzchirurgie, however, also encompasses maximum medical treatment on a case-by-case basis and emergency surgical treatment in a mass casualty situation. Training, for example, may consist of a 6-year basic training course in surgery followed by specialist training in abdominal surgery, traumatology, and courses in further disciplines — e.g., urology, gynecology, or neurosurgery. In addition to the qualifications required by the Landesärztekammem (professional organizations of German physicians at the federal countries level), military surgeons who are to become senior medical officers should also be qualified to provide immediate non-surgical emergency care. In these times, the education of military surgeons remains a great challenge. Motivation to work as a surgeon in the armed forces with multiple deployments during the career requires enthusiasm and professionalism. The attractivness of the training institution and the home hospital is key for successful work as a military surgeon.

Die peroneale Reaktionszeit: Untersuchung in einem Normalkollektiv

ZusammenfassungDie chronische Instabilität des Sprunggelenkkomplexes stellt einen ernstzunehmenden Residualzustand nach akutem Supinationstrauma dar. Sie ist einerseits durch mangelhaften ligamentären Zusammenhalt, andererseits durch Defizite im neuromuskulären System begründet. Ein anerkannter Parameter zur Beurteilung des propriozeptiven Defizits ist die peroneale Reaktionszeit (PRT).In einer experimentellen Studie mit 120 Probanden wurde der Einfluss anthropometrischer Größen auf die PRT untersucht. Die Studienteilnehmer wurden einer raschen Winkeländerung auf einer Kippplattform ausgesetzt und anschließend die muskuläre Reaktion der Peronealmuskeln elektromyographisch analysiert.Die Ergebnisse zeigen, dass der objektive Parameter PRT gegen extrinsische und intrinsische Einflussgrößen weitgehend stabil ist. Jedoch zeigt die vorliegende Studie eine mit zunehmendem Alter signifikante Verlängerung der PRT. Daraus ergibt sich zwingend für zukünftige Studien und für die klinische Anwendung eine altersdifferenzierte Betrachtung der PRT.AbstractChronic functional instability is a residual problem after acute ankle sprain. Reasons may be weak ligaments and/or a deficit in the proprioceptive system. Studies have shown that peroneal reaction time (PRT) canbe used to quantify proprioceptive performance.To test the influence of anthropometric data on PRT, an experimental study with 120 healthy volunteers was performed. Surface electrodes recorded the activity of the peroneal muscles after a sudden inversion on a tilting platform.It was found that PRT is not influenced by extrinsic or anthropometric data. Furthermore, the results prove a significant slackening in PRT with increasing age. Therefore, the patients age must to be considered in judging the PRT.

The influence of a controlled active motion splint on proprioception after anterior cruciate ligament plasty. A prospective randomized study

ZusammenfassungHintergrundNach einer VKB-Ruptur besteht neben der mechanischen eine durch das propriozeptive Defizit bedingte funktionelle Instabilität. Es sollte überprüft werden, ob durch Einsatz von CAM-Schienen unmittelbar postoperativ das propriozeptive Defizit gesenkt werden kann.Patienten und MethodenIn dieser prospektiv randomisierten Studie wurden 50 Patienten nach VKB-Plastik in eine PT-Gruppe (Physiotherapie) und eine CAM-Gruppe (Physiotherapie + aktive Bewegungsschiene) eingeteilt. Die propriozeptive Leistung wurde mit einem passiven Winkelreproduktionstest gemessen. ErgebnisseBei Entlassung wurde bei 80% der CAM-Patienten und 25% der PT-Patienten eine Reduktion des propriozeptiven Defizits gemessen. Die CAM-Gruppe zeigte in der Hauptzielgröße eine Verbesserung um 83,7%. Die PT-Gruppe verschlechterte sich um 39,3%. Es bestand kein signifikanter Unterschied zwischen der CAM-Gruppe und einer gesunden Kontrollgruppe. SchlussfolgerungDurch den postoperativen Einsatz der CAM-Schiene kann das propriozeptive Defizit gegenüber einer alleinigen Physiotherapie signifikant reduziert werden.AbstractBackgroundA ruptured anterior cruciate ligament (ACL) leads to both mechanical and functional instability. Functional instability is caused by proprioceptive deficit. The aim of this study was to determine whether the proprioceptive deficit can be reduced by using a controlled active motion (CAM) splint postoperatively. Patients and methodsA total of 50 patients with ACL rupture were randomized into two groups. After ACL plasty the PT group received postoperative physiotherapy, while the CAM group were managed with a CAM splint and physiotherapy. Proprioceptive ability was measured with a passive angle-reproduction test. ResultsOn the day of discharge 80% of the patients in the CAM group and 25% in the PT group had a reduced proprioceptive deficit. Overall the main measured value in the CAM group improved by 83.7%, but deteriorated by 39.3% in the PT group. There was no significant difference between the CAM group and a healthy control group.ConclusionUsing a CAM splint in addition to physiotherapy after ACL plasty in comparison to physiotherapy alone decreases the proprioceptive deficit significantly. We recommend the use of a CAM splint in the postoperative management following ACL plasty.