Arthroscopic controlled reduction of femoral condyle fractures using a retrograde navigated approach

Isolated depression fractures of the femoral condyle are rare, but severe injuries due the destroyed congruency of the articular surface in the weight-bearing region of the joint. In most cases, an arthrotomy with fragment reduction and internal fixation by screws buttress or plates is performed. Disadvantages of this procedure are the approach-related complications. Furthermore, an implant removal is necessary, if a secondary osteoarthrosis develops. We present a female patient with a hyperflexion trauma of her right knee, resulting in an isolated depression fracture of the medial femoral condyle. To avoid arthrotomy-related morbidity, the impressed fragment was retrograde addressed using navigated guidance and reduced indirectly under arthroscopic control. Via the retrograde intraosseous tunnel a biodegradable screw was used as a buttress against the fragment to prevent a re-dislocation. The fracture healed without any complications and the patient re-administered her sports activities at 10 weeks follow-up. This procedure enables an accurate reduction and stable fixation of joint depression fragments via a minimal invasive approach.     

Survival trends and predictors of mortality in severe pelvic trauma: estimates from the German Pelvic Trauma Registry Initiative

Study objective

To determine longitudinal trends in mortality, and the contribution of specific injury characteristics and treatment modalities to the risk of a fatal outcome after severe and complex pelvic trauma.

Methods

We studied 5048 patients with pelvic ring fractures enrolled in the German Pelvic Trauma Registry Initiative between 1991 and 1993, 1998 and 2000, and 2004 and 2006. Complete datasets were available for 5014 cases, including 508 complex injuries, defined as unstable fractures with severe peri-pelvic soft tissue and organ laceration. Multivariable mixed-effects logistic regression analysis was employed to evaluate the impact of demographic, injury- and treatment-associated variables on all-cause in-hospital mortality.

Results

All-cause in-hospital mortality declined from 8% (39/466) in 1991 to 5% (33/638) in 2006. Controlling for age, Injury Severity Score, pelvic vessel injury, the need for emergency laparotomy, and application of a pelvic clamp, the odds ratio (OR) per annum was 0.94 (95% confidence interval [CI] 0.91–0.96). However, the risk of death did not decrease significantly in patients with complex injuries (OR 0.98, 95% CI 0.93–1.03). Raw mortality associated with this type of injury was 18% (95% CI 9–32%) in 2006.

Conclusion

In contrast to an overall decline in trauma mortality, complex pelvic ring injuries remain associated with a significant risk of death. Awareness of this potentially life-threatening condition should be increased amongst trauma care professionals, and early management protocols need to be implemented to improve the survival prognosis.     

How do visual,spectroscopic and biomechanical changes of cartilage correlate in osteoarthritic knee joints?

Background

Characteristic changes in cartilage of human knee joints with different degrees of osteoarthritis (OA) have been investigated by visual, biophotonical and biomechanical examination. Knowledge about the cartilage composition and changes during the development of OA is important for diagnostic decisions and understanding the pathogenesis of OA.

Methods

Thirty two patients with severe knee OA received endoprosthetic replacement. During surgical intervention cartilage specimen were harvested from defined surface areas of the joints. The degree of cartilage defects was classified visually (ICRS Grade: International Cartilage Repair Society), biophotonically (NIRS: near infrared spectroscopy) and biomechanically (Young’s Modulus). To characterise links between the investigated parameters the Spearman’s rank correlation coefficient was used.

Findings

Significant negative correlations were found between visual macroscopic degree of degeneration (ICRS Grade) and biophotonic characteristics (NIRS) (ρ = −0.467) or cartilage stiffness (Young’s Modulus) (ρ = −0.501). Between NIRS and Young’s Modulus significant positive correlation of ρ = 0.535 was detected.

Interpretation

Visual, biophotonic and biomechanical properties of cartilage reveal strong correlations in all degrees of cartilage defects in patients with severe OA. According to these results, we indicate that an objective, non-invasive and non-destructive measurement of cartilage properties during open and arthroscopic knee surgery is possible by NIRS and provide a novel tool to evaluate disease intervention and treatment.     

Beckenring- und Azetabulumverletzungen

The definitive treatment of injuries to the pelvic ring and of acetabular fractures usually requires extensive surgical access. This means wide exposure of the fractured bones and marked additional soft tissue trauma caused by the surgery. Alternatives to these approaches with the extreme exposure they entail would be beneficial. The use of computer-controlled navigated operation techniques for closed introduction of screws has a number of advantages. Our own experience has shown that besides the more restricted damage to the soft tissue mantle and the lower morbidity associated with the surgical approach, the increased precision with which the implants are placed also has a distinctly positive influence. It has also been possible to reduce the radiation burden substantially because of the shorter exposure times, which is good not only for the patients but also for the surgical team. At present, because little experience is available with them, the use of surgical techniques involving computer navigation should be restricted to carefully selected cases. The high costs of acquisition and maintenance have to be seen as drawbacks to the method. As these are highly specialized interventions they should not be performed except in appropriate special centres.     

Navigated Percutaneous Screw Fixation of a Periprosthetic Acetabular Fracture

Periprosthetic fractures are severe complications of total hip arthroplasty with increasing incidence. Most fractures are localized around the femoral component of prosthesis, whereas periacetabular fractures are rare and their management is difficult. In most cases, an operative procedure with revision and exchange of the acetabular cup is necessary. The approaches are demanding and an increased risk of complications is reported. We present the case of a female patient with a cementless total hip arthroplasty due to severe arthritis, suffering of an infratectal transverse periprosthetic fracture. After an initial conservative treatment attempt, we performed a minimally invasive screw fixation using navigated 2-dimensional fluoroscopic guidance. In this report, the literature for treatment recommendations is reviewed and the chosen navigation technique discussed.     

Compression nailing for posttraumatic rotational femoral deformities: open versus minimally invasive technique

Between January 1996 and December 1999, we performed 30 derotational osteotomies with compression nailing in 29 patients. In 18 cases (group 1), we used an intramedullary saw (minimally invasive technique), and in 12 cases (group 2), we used a conventional open technique. Follow-up included clinical, conventional radiological, and computer tomographical assessment. The mean angle of derotation was 28.6±12.3° in group 1 and 27.6±10.7° in group 2. The postoperative mean rotational deviation between left and right side was 7.9±6.7° in group 1 and 6.6±4.4° in group 2. There were five postoperative complications: two delayed unions, two insufficient corrections, and one infection. There was no significant difference between the groups. When using the minimally invasive technique, we recommend the derotation angle to be marked with Schanz screws instead of Kirschner wires, as soft-tissue resistance may lead to bending of these.

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Résumé Entre janvier 1996 et décembre 1999, nous avons exécuté 30 ostéotomies fémorales de dérotation avec enclouage en compression chez 29 malades. Dans 18 cas (groupe 1), nous avons utilisé un scie intramédullaire (technique mini invasive) et dans 12 cas (groupe 2), nous avons utilisé une technique ouverte conventionnelle. Le suivi à était fait par estimation clinique, radiologie conventionnelle, et tomodensitométrie. Langle moyen de dérotation était 28,6°±12,3 dans le groupe 1 et 27,6°±10.7 dans le groupe 2. La déviation rotationnelle moyenne postopératoire entre le côté gauche et le côté droit était 7,9°±6.7 dans le groupe 1 et 6,6°±4.4 dans le groupe 2. Il y avait cinq complications postopératoires: deux retards de consolidation, deux corrections insuffisantes et une infection. Il ny avait aucune différence significative entre les groupes. Quand on utilise la technique mini invasive nous recommandons de marquer les angles de dérotations avec des vis de Schanz plutôt que des broches de Kirschner car la résistance des parties molles peut les courber.