Biological fixation of subtrochanteric fractures by external fixation

Fifty-one subtrochanteric fractures have been stabilized by external fixation over the last 9 years. Union occurred in all types of fractures, usually within 6 months. Soft tissue interposition led to non-union in three patients. Refracture in one patient and significant limb-length discrepancy in two patients was seen. The technique is versatile, easily reproducible and ‘biological’. Protected weight-bearing is not necessary after removal.     

Method of fracture fixation using external fixation devices

An improvement of the results of treatment can be reached, beside respecting the indication of external fixateurs, with correct tactics of the treatment. Because of the disadvantages of the fixateur externe, we strive to restrict their use, to the time by all means necessary, and if possible to use other methods of fixation. This is motivated especially by the effect on fracture healing and the hindering of the movements and activity of the patient.     

Prediction of fixation failure after sliding hip screw fixation

Cut-out of the lag screw is the commonest cause of fixation failure after sliding hip screw fixation of extracapsular hip fracture. A number of technical aspects of surgery have been used to asses the risk of cut-out. This study was to determine which of these indicators was the most reliable predictor of cut-out. The anterior-posterior and lateral post-operative radiographs of 23 cases of cut-out were compared with those of 77 cases of uneventful fracture healing. The tip-apex distance with correction for magnification was found to show the most significant difference between patients with cut-out against those without (P = 0.001), followed by the lag screw position on the lateral radiographs (P = 0.0095 and 0.014), reduction of the fracture on the anterior-posterior radiograph (P = 0.011 and 0.016) and the uncorrected tip-apex distance (P = 0.019). We recommend that for audit and research purposes the corrected tip-apex distance, fracture reduction and implant positioning methods should be used. For routine clinical practice, the uncorrected tip to apex distance, which is sum of the distance from the tip of the lag screw to the apex of the femoral head on anterior-posterior and lateral radiograph, and fracture reduction angle on the anterior-posterior radiograph are recommended.     

Trans-sacral fixation for failed posterior fixation of the pelvic ring

Introduction: In the treatment of certain pelvic ring pathologies (non-unions and failure of ilio-sacral screw fixation) trans-sacral fixation (i.e. fixation from iliac wing to the other traversing the body of S1) may be necessary. The purpose of our study was to describe our early experience and describe the surgical technique. Materials and methods: Seven cases of trans-sacral fixation were identified with a mean patient age of 49-years-old with four females and three males. The diagnosis at the time of trans-sacral fixation was failure of posterior ring fixation in four (three of which had vertical sacral fractures), mal-position of iliosacral (IS) screw in one, failure of fusion of sacroiliac (SI) joint in two. All these cases were augmented with a 4.5 mm reconstruction plate placed in tension posteriorly. Results: At average follow up of 39 months (range 24–75), all patients achieved union. There were no neurological or vascular complications. Two patients required reoperations prior to union. Our current use for this technique is with a 8.0 mm screw (16 mm thread). Conclusions: Initial experience with trans-sacral fixation has proven to be very effective technique to solve the most difficult problems in posterior pelvic ring fixation. We reserve its use to the following indications: nonunion/malunion of the pelvic ring, and sacral fractures.     

External fixation

Summary The conclusion from the above clinical and experimental presentation is that stabilization by using external fixation in problematic cases is the method of choice because the risk of infection is better than by using the standard methods of plating and nailing.Using external fixation based on the tubular system of ASIF we can achieve rigid stability. Correct application allows early mobilization ensuring alignment even in bone defects. This method of treatment also facilitates the care of wounds.Our experimental and clinical information provides us with the opportunity to offer a systematic classification of each individual type of external fixation and its merits, as described above in types I, II, and III and its application in different situations.Our clinical experience also shows that external fixation has greatly reduced the risk of amputation in these problematic cases, but it has not solved all the problems associated with the primary injury.The advantage of the three-dimensional external fixation type III can also be seen in the case of arthrodesis of the knee joint. Here there is a better neutralization of the bending moment, than by using type II.Finally we would like to emphasize that the external fixation is not the panacea for every problematic case and each surgeon should be well aware of its methodical and correct application, as abuse of external fixation may lead to secondary complications.

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Zusammenfassung Die Osteosynthese mit dem Fixateur exteren bietet ein Behandlungsverfahren für klinische Problemfälle, bei denen sich aus der lokalen Schädigung oder einer sekundär aufgetretenen Komplikation ein erhöhtes Risiko für die Nagel- oder Plattenosteosynthese ableiten läßt.Mit dem Rohrfixateur externe der AO kann in den meisten Fällen Übungsstabilität erzielt werden, bei offenen und bei infizierten Frakturen ist die Weichteilbehandlung erleichtert.Auf Grund klinisch-experimenteller Untersuchungen schlagen wir eine Klassifizierung der Anwendungsformen der Fixateur-externe-Osteosynthese vor, unterscheiden in Typ I, II, III und zeigen die entsprechenden Indikationen auf.Die Fixateur-externe-Osteosynthese hat bei klinischen Problemfällen die Amputationsgefahr verringert.Auch für die Kniearthrodese empfehlen wir die Anwendungsform Typ III, mit der gegenüber Typ II das ventral auftretende Biegemoment durch Neutralisiexung der Zugkräfte nicht zur Auswirkung kommt.Die Fixateur-externe-Osteosynthese erfordert eine korrekte Technik und wie jede andere Osteosynthese die Beachtung der Regeln der Asepsis.

     

Biologic fixation

One of the major problems of implant surgery is the failure of the bone-cement interface. Because of such failures, observed with increasing frequency with the passage of time, biologic fixation of total joint implants by means of bone ingrowth has become the focus of considerable interest among orthopedic surgeons. Actual bone ingrowth has been demonstrated into porous metals, resulting in a strong interface between metal and bone. Many clinical trials of biologic fixation, including endoprostheses and total hip, shoulder, and knee prostheses, are being conducted. The brief experience of such fixation in humans supports the hypothesis that bone ingrowth will provide stable fixation for load-bearing prostheses. Many questions remain to be answered about biologic fixation and the burden that falls upon the clinical scientist to identify the proper niche for this process in the care of the musculoskeletal patient.