Thomas Heinz

Postoperative pain and subcutaneous oxygen tension

Surgical patients randomly assigned to standard pain control had postoperative subcutaneous oxygen partial pressures that were significantly less than patients given better pain treatment. Our data suggest that control of postoperative pain is a major determinant of surgical-wound infection and should be given the same consideration as maintaining adequate vascular volume and normothermia.

Implant failure of the gamma nail

The gamma nail is a temporary implant characterised by a limited life expectancy under continuous dynamic stress. We reviewed a series of 839 patients with gamma nail stabilisation and found two fatigue fractures (0.2%) at the aperture of the distal locking holes. This complication has not been described in the literature. Metallurgic and scanning electron microscopic examinations proved that the fatigue zones occurred at the clover-leaf grooves, which is where the diameter of the gamma nail is reduced. The clover-leaf diameter is of no biomechanical use in gamma nail stabilisation. We suggested product modification of the gamma nail to produce implants with a round diameter instead of a clover-leaf shape. A modified implant is already in use at our institution.

Femoral neck fracture after removal of the standard gamma interlocking nail: a cadaveric study to determine factors influencing the biomechanical properties of the proximal femur

We retrospectively analyzed 1334 patients who were implanted standard gamma interlocking nails (SGN) to stabilize trochanteric femoral fractures over the years 1992-1998. Reoperation to remove the nails was performed in 37 patients, in 9 of them purely because of pain. Three out of these 9 patients with removed SGN suffered femoral neck fractures in the early postoperative course after having been mobilized to full weight-bearing capacity. This complication was not observed with other implant systems and, considering the notoriously high complication rate of femoral neck fractures, severely reduces the value of the SGN concept per se. These findings in combination with other known shortcomings of SGNs prompted us to conduct an experimental study on the fracture force of excavated femurs addressing the hypothesis that the specific design of the SGN is responsible for the occurrence of fatigue fractures of the femoral neck. Eighteen matched pairs of fresh human cadaveric proximal femurs, which were treated by insertion and removal of (i) SGNs or (ii) dynamic hip screws (DHS) or (iii) by excavation in the absence of an implant, were subjected to incremental loading cycles and compared to the untreated contralateral femurs. Overall, the fracture force was found to be significantly lower among the treated than among the untreated bones. However, the fracture force required after removal of the DHS system was still significantly higher than for SGN or excavation alone. In this way, our findings demonstrate that removing relatively big implants such as SGN can cause serious complications such as femoral neck fractures. We therefore recommend to leave this type of device in place even after fracture healing except in cases of deep and chronic infection.

Surgical Treatment of Metastatic Fractures of the Femur : A Retrospective Analysis of 142 Patients

BACKGROUND Pathologic fractures of long bones are common complications of the metastatic disease; however, the influence of the primary tumor, the stage of metastatic disease, different surgical techniques, and the postoperative mobility on the postoperative survival has not been clearly defined. The aim of this retrospective study was to evaluate outcome after surgical treatment for pathologic femur fractures. PATIENTS AND METHODS A consecutive series of 142 patients with metastatic fractures of femur were retrospectively studied. The operative treatment was based on intramedullary fixation (n = 94), gliding screws (n = 15), other extramedullary fixation devices (n = 7), and arthroplasty (n = 23). RESULTS Seventeen percent and 6% of the patients survived 1 year and 2 years, respectively, postoperatively. Postoperative survival was higher in patients with pathologic femur fractures because of breast carcinoma than in patients with other primary tumors. The rate of complications for patients with intramedullary stabilization, gliding screw fixation, and endoprosthetic replacement was 3.2%, 20%, and 8.6%, respectively. CONCLUSION Although many studies describe the endoprosthetic replacement as the safer method to treat pathologic femur fractures, our data showed that intramedullary stabilization and endoprosthetic replacement to be safe, and equivalent alternatives to treat complete pathologic fractures of the femur in patients with advanced metastatic disease.

Predictive value of S-100B protein and neuron specific-enolase as markers of traumatic brain damage in clinical use

Objective: S-100B and NSE proteins are considered to be neurobiochemical markers for the brain damage. The aim of this study was to consider the diagnostic and prognostic validity of the initial serum levels of S-100B and NSE in clinical use. Methods: Forty-five patients with traumatic brain injury were included in this prospective study. Neurologic examination and CCT-scan were performed. S-100B and NSE were analysed. Patients were divided in two groups depending on the severity of injury. Results: The results showed a significant difference between the S-100B serum concentration and the two groups—minor head injuries and severe head injuries. A statistically significant correlation was observed between an increase of S-100B and NSE serum values and a cerebral pathological finding in CT scans. Conclusion: The clear correlation between S-100B and NSE serum concentrations and CCT findings does not validate both markers as an independent predictor of diagnosis and prognosis of brain injury.

Indications for implant removal in healed proximal femoral fractures

SummaryBackground: Reviewing patients operatively stabilized following proximal femoral fractures we found several factors that lead to significant complications. We conducted this survey of proximal femoral fractures stabilized with the implants which were used most frequently. Purpose was to work out causes and indications to remove implants which were solely employed to stabilize proximal femoral fractures. Methods: The indication for using a Dynamic Hip Screw® (DHS) were fractures AO-Class. 31-B or 31-Al. A Gamma Locking Nail® (GN) was applied in unstable or comminuted trochanteric fractures. We retrospectively analysed 2553 patients who received either a DHS or a GN within seven years. Results: Removal of the implants was indicated in 3.2 % mostly due to complications. Most frequent “modes of complication” that lead to the removal of one of the implants were avascular necrosis (AVN) of the femoral head (24 %), patients request (20 %) and ipsilateral shaft fractures (17 %). Conclusions: Referring to the results absolute indications to remove an implant are AVN, deep chronic infections, shaft fractures and when “cutting out” appears.ZusammenfassungGrundlagen: Aufgrund der steigenden Inzidenz proximaler Femurfrakturen gewinnen auch die spezifischen Komplikationen dieser meist operativ stabilisierten Verletzungen an Bedeutung. Daher haben wir die Ergebnisse der am häufigsten angewandten Implantate retrospektiv analysiert. Ziel der Studie war es, Ursachen und Indikationen für die operative Entfernung des Osteosynthesematerials zu evaluieren. Methodik: Indikationen waren proximale Femurfrakturen entsprechend der AO-Klassifikation 31-B oder 31-Al. Die dynamische Hüftschraube (Dynamic Hip Screw®) wurde bei stabilen, der Gammanagel (Gamma Locking Nail®) bei instabilen Frakturen angewandt. Wir analysierten die Ergebnisse von 2553 Patienten aus einem Zeitraum von 7 Jahren. Ergebnisse: Die komplikationsbedingte Materialentfernung war in 3,2 % der Fälle indiziert. Die häufigsten Ursachen waren die avaskuläre Femurkopfnekrose (24 %), der Patientenwunsch aufgrund subjektiver Beschwerden (20 %) und die ipsilaterale Schaftfraktur (17 %). Schlußfolgerungen: Bezogen auf die Resultate sehen wir die Operationsindikation zur Implantatentfernung bei avaskulärer Nekrose, tiefer Infektion, Femurschaftfrakturen und beim sogenannten kranialen Durchschneiden der Hüftschraube.

Der neue SCN zur behandlung distaler femurfrakturen

ZusammenfassungIn den letzten Jahren wurden verschiedene Implantate zur intramedullären Stabilisierung distaler Femurfrakturen entwickelt. In einer retrospektiven Analyse wurde der GSHN (Green-Seligson-Henry Nail) mit dem neuen SCN (Supra-Condylar Nail) verglichen. Verändert wurden an diesem Nagel die anatomische Krümmung, eine arretierbare distale Befestigung Bowie eine Kondylenschraube mit Mutter.Von Januar 1997 bis Juli 1998 wurden 16 Patienten mit 17 Frakturen (Alter von 17 bis 94 Jahren, im Mittel 55,1 Jahre) mit einem SCN versorgt. Zum Vergleich wurden Daten von 17 Patienten (Alter 16 bis 92 Jahre, im Durchschnitt 62,4 Jahre) herangezogen, deren Frakturen von Oktober 1994 bis Mai 1997 mit einem GSHN stabilisiert wurden. Nach der AO-Klassifikation waren 55,9% der Frakturen vom Typ A und 44,1 % vom Typ C.Der Nachuntersuchungszeitraum betrug 7,7 Monate (6,7 bis 10,1 Monate). Der Vergleich der Untersuchungsdaten zeigte bei Patienten, die mit dem SCN versorgt wurden, eine deutlich verminderte Schmerzsymptomatik (Leung-Score) Bowie einen höheren Anteil an anatomisch einwandfreien Ausheilungsergebnissen.Die beiden Kollektive sind zu klein, um statistisch signifikante Unterschiede zu erheben. Die Verwendung des neuen SCN erbrachte operativ technische Vorteile, die sich auch im besseren Ausheilungsergebnis widerspiegeln.AbstractDifferent implants have been developed in the past years for internal stabilization of distal femoral fractures. In a retrospective analysis the GSHN (Green-Seligson-Henry Nail) was compared with the new SCN-nail (Supra-Condylary Nail). New are the anatomical rounding, the new condylar screw with a nut and the distal interlocking screw.From January 1997 to July 1998 16 patients with 17 fractures (age 17 to 94 years, mean 55.1 years) were treated with a SCN. Results were compared with 17 patients (age 16 to 92 years, mean 62.4 years) who were stabilized with a GSHN from October 1994 to May 1997. Using the OTA classification there were 55.9% Type A and 44.1% Type C fractures.The follow-up period was 7.7 months (6.7 to 10.1 months). Comparing the results of the examination the group of patients treated with the SCN had less pain (Leung Score) and an increased proportion of anatomical correct healing results.Both groups are not big enough to find statistical significant differences. The use of the new nail showed technical advantages during surgery, reflecting also in better healing results.

Stabilisation distaler Femurfrakturen mittels retrograder intramedullärer Technik

ZusammenfassungGrundlagen: Die Entwicklung eines intramedullären Nagels zur Stabilisierung distaler Femurfrakturen in retrograder Technik war ein wesentlicher Beitrag in der Behandlung dieser sehr schwierig zu versorgenden Knochenbrüche. Der SCN (Supracondylar Nail) ist eine Modifizierung bisher bekannter retrograd anzuwendender Implantate, wie etwa des GSH-(Green-Seligson-Henry)-Nagels.Deutliche Vorteile zeigte das distale Verriegelungs- und Kompressionssystem des doppelt geknickten soliden Kraftträgers. Die kanülierte Kondylenschraube erlaubt eine transversale Kompression der kondylären Bruchfragmente auch bei osteoporotischem Knochen. Diese zusätzliche Stabilisierungsmöglichkeit erhöht die Chance auf eine geschlossene Kondylenrekonstruktion und verbessert die Möglichkeiten der Frühmobilisation. Methodik: In einer retrospektiven Analyse wurden 34 Patienten, die in einem Zeitraum von 3 Jahren mit einem retrograden Nagel operativ versorgt wurden nachuntersucht. Das Patientenkollektiv umfaßt 28 Frauen und 6 Männer mit einem Durchschnittsalter von 62,4 Jahren (15–97 Jahre).Sechzehn Patienten, die mit einem SCN Nagel versorgt wurden, und 17 Patienten, bei denen ein GSH Nagel Verwendung fand wurden nachuntersucht. Ergebnisse: Die Frakturen teilten sich nach der AO Klassifikation in 19 Frakturen vom Typ A und 15 vom Typ C. Fünf Patienten erlitten ein Polytrauma, einer dieser verstarb nach 19 Tagen.Neben 2 pathologischen und 4 offenen Frakturen fand sich bei einem Patienten eine Kettenverletzung. Bei alten Patienten waren häusliche Stürze die häufigste Unfallursache, während bei Patienten geringeren Alters Stürze aus großer Höhe, oft in suizidaler Absicht, sowie Verkehrsunfälle die Hauptursache darstellten. Es fanden sich 14 Patienten mit liegenden Implantaten im Bereich des proximalen Oberschenkels.Eine gedeckte Reposition und eine suffiziente Stabilisierung waren in allen Fällen möglich. Abhängig von der Frakturform und den zusätzlichen Erkrankungen erfolgte eine Mobilisierung mit Teilbelastung zum frühest möglichen Zeitpunkt. Die Ergebnisse werden in bezug auf knöcherne Konsolidierung, Achsenergebnis und der Auswertung nach Leung zur Darstellung gebracht. Eine einzige Fraktur konnte nicht zur Ausheilung gebracht werden. Diese septische Pseudarthrose mußte mit einer Prothese im Intervall behandelt werden. Schlußfolgerungen: Mit Ausnahme einer Fraktur konnten bei allen anderen eine knöcherne Konsolidierung unter geringerer Komplikationsrate als bei Alternativverfahren erreicht werden. Die Vorteile einer geschlossenen, intramedullären Technik waren evident.SummaryBackground: The development of the intramedullary nail in stabilisation of very distal femur fractures through retrograde technique has become an essential form of treatment of these difficult fractures. The Supracondylar Nail(SCN) is a modified form of the implants applied until now, such as the Green-Seligson-Henry Nail(GSH). The locking and compression system of the double angled device presented significant advantages. The cannulated condyle screws enable a transverse compression of condyl fragments even in osteoporotic bone. This additional possibility of stabilisation increases the chance of closed reconstruction and fixation, which is favorable for early ambulation. Methods: In a retrospective analysis, 34 patients, who had received a retrograde nail were followed up over a span of 3 years. This group consisted of 28 women and 6 men with an average of age of 62,4 years (15–97). 16 patients, treated with SCN and 17 patients, who had received a GSH nail in a similar study were followed up. Results: The fractures were classified according to AO parameters; with 19 fractures of the typ A and 15 of typ C. Five patients suffered from multiple trauma(or polytrauma) and one died 19 days after accident. Beside 2 pathiologic and four open fractures, one patient had a chain-injury. Among the older patients, most had fallen at home, whereas younger patients usually had fallen from great hights (often suicid attempts) or been injured in car accidents. 14 Patients had presented with implants in the proximal femur. A closed reduction and sufficient stabilisation were possible in all cases. Depending on the fracture typ and additional morbidity the patients were mobilised as soon as possible under partial weight-bearing. 6–10 month following injury the patients were classified according to the Leung-Score. There we saw a definitive improvement when using the SCN, as opposed to the GSH nail. The results were analysed furthermore according to bone consolidation and axis deviation. Only one fracture showed non-union. This septic pseudarthrosis had to have intermediary treatment with a prosthesis. Conclusions: All fractures but one showed good bone consolidation with lower rates of complications compared to alternative methods. Advantages of closed, intramedullary technique were evident.