Timo Schmid

Lateral External Fixation-A New Surgical Technique for Displaced Unreducible Supracondylar Humeral Fractures in Children

BACKGROUND Percutaneous Kirschner wire fixation represents the classic treatment for displaced supracondylar humeral fractures in childhood. This type of treatment first requires satisfactory reduction of the fracture. Failure to achieve a satisfactory reduction or inadequate stabilization can result in instability of the fracture fragments, which can result in either an unsatisfactory cosmetic or functional outcome. In our experience, these problems can be overcome with the use of a small lateral external fixator. METHODS Between 1999 and 2005, thirty-one of 170 Gartland type-III supracondylar humeral fractures were treated with a lateral external fixator. The outcome of treatment was analyzed with regard to limb alignment, elbow movement, cosmetic appearance, and patient satisfaction. RESULTS In twenty-eight of the thirty-one patients, a satisfactory reduction was achieved with closed methods. All children except one had a normal or good range of movement. The cosmetic result was excellent in all cases. All of the children and their parents stated that they would choose this treatment again. CONCLUSIONS The use of a small lateral external fixator seems to be a safe alternative for the treatment of displaced supracondylar fractures of the humerus when a closed reduction appears to be unattainable by means of manipulation alone or when sufficient stability is not achieved with standard methods of Kirschner wire fixation.

Ankle Arthrodesis versus Total Ankle Replacement: How Do I Decide?

Taking into account numerous individual criteria, the correct indication substantially influences the outcome of patients with end-stage ankle arthritis treated by ankle arthrodesis or total ankle replacement. The purpose of this report is to assist the foot and ankle surgeon or orthopedic surgeon involved in choosing ankle arthrodesis or total ankle replacement in decision-making. Balancing the criteria that are discussed in consideration of the recent relevant literature and evidence available, the surgeon is directed to the correct individual decision.

Ankle joint pressure changes in a pes cavovarus model: supramalleolar valgus osteotomy versus lateralizing calcaneal osteotomy

Background: A fixed cavovarus foot deformity can be associated with anteromedial ankle arthrosis due to elevated medial joint contact stresses. Supramalleolar valgus osteotomies (SMOT) and lateralizing calcaneal osteotomies (LCOT) are commonly used to treat symptoms by redistributing joint contact forces. In a cavovarus model, the effects of SMOT and LCOT on the lateralization of the center of force (COF) and reduction of the peak pressure in the ankle joint were compared. Methods: A previously published cavovarus model with fixed hindfoot varus was simulated in 10 cadaver specimens. Closing wedge supramalleolar valgus osteotomies 3 cm above the ankle joint level (6 and 11 degrees) and lateral sliding calcaneal osteotomies (5 and 10 mm displacement) were analyzed at 300 N axial static load (half body weight). The COF migration and peak pressure decrease in the ankle were recorded using high-resolution TekScan pressure sensors. Results: A significant lateral COF shift was observed for each osteotomy: 2.1 mm for the 6 degrees (P = .014) and 2.3 mm for the 11 degrees SMOT (P = .010). The 5 mm LCOT led to a lateral shift of 2.0 mm (P = .042) and the 10 mm LCOT to a shift of 3.0 mm (P = .006). Comparing the different osteotomies among themselves no significant differences were recorded. No significant anteroposterior COF shift was seen. A significant peak pressure reduction was recorded for each osteotomy: The SMOT led to a reduction of 29% (P = .033) for the 6 degrees and 47% (P = .003) for the 11 degrees osteotomy, and the LCOT to a reduction of 41% (P = .003) for the 5 mm and 49% (P = .002) for the 10 mm osteotomy. Similar to the COF lateralization no significant differences between the osteotomies were seen. Conclusion: LCOT and SMOT significantly reduced anteromedial ankle joint contact stresses in this cavovarus model. The unloading effects of both osteotomies were equivalent. More correction did not lead to significantly more lateralization of the COF or more reduction of peak pressure but a trend was seen. Clinical Relevance: In patients with fixed cavovarus feet, both SMOT and LCOT provided equally good redistribution of elevated ankle joint contact forces. Increasing the amount of displacement did not seem to equally improve the joint pressures. The site of osteotomy could therefore be chosen on the basis of surgeon’s preference, simplicity, or local factors in case of more complex reconstructions.

The modified Lapidus fusion.

Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a powerful technique to correct hallux valgus deformities. The disadvantages are a high complication rate and a long postoperative rehabilitation period. It is only performed in 5% to 10% of all hallux valgus deformity corrections but remains, however, an important procedure, especially in moderate to severe deformities with intermetatarsal angles more than 14°, hypermobility of the first ray, arthritis of the first tarsometatarsal joint, and recurrent deformities. This article provides an overview of the procedure with special focus on the surgical technique.

Supramalleolar Osteotomies for Posttraumatic Malalignment of the Distal Tibia

Supramalleolar osteotomies of the tibia (SMOT) for posttraumatic distal tibial malalignment has shown to reduce pain, improve function and radiographic signs of osteoarthritis, and delay ankle arthrodesis or total joint replacement. The procedure also protects the articular cartilage from further degenerative processes by shifting and redistributing loads in the ankle joint. It is technically demanding and requires extensive preoperative planning. The type of osteotomy (opening vs closing wedge) does not influence the final outcome. However, based on the limited evidence, a grade I treatment recommendation has been given for supramalleolar osteotomies of the tibia to treat mild to moderate ankle arthritis in the presence of distal tibial malalignment.

Operative Treatment of Acute Fractures of the Tarsal Navicular Body Midterm Results With a New Classification

Background: Treatment of displaced tarsal navicular body fractures usually consists of open reduction and internal fixation. However, there is little literature reporting results of this treatment and correlation to fracture severity. Methods: We report the results of 24 patients treated in our institution over a 12-year period. Primary outcome measurements were Visual-Analogue-Scale Foot and Ankle score (VAS-FA), AOFAS midfoot score, and talonavicular osteoarthritis at final follow-up. According to a new classification system reflecting talonavicular joint damage, 2-part fractures were classified as type I, multifragmentary fractures as type II, and fractures with talonavicular joint dislocation and/or concomitant talar head fractures as type III. Spearman’s coefficients tested this classification’s correlation with the primary outcome measurements. Mean patient age was 33 (range 16-61) years and mean follow-up duration 73 (range 24-159) months. Results: Average VAS-FA score was 74.7 (standard deviation [SD] 16.9), and average AOFAS midfoot score was 83.8 (SD = 12.8). Final radiographs showed no talonavicular arthritis in 5 patients, grade 1 in 7, grade 2 in 3, grade 3 in 6, and grade 4 in 1 patient. Two patients had secondary or spontaneous talonavicular fusion. Spearman coefficients showed strong correlation of the classification system with VAS-FA score (r = −0.663, P < .005) and talonavicular arthritis (r = 0.600, P = .003), and moderate correlation with AOFAS score (r = −.509, P = .011). Conclusion: At midterm follow-up, open reduction and internal fixation of navicular body fractures led to good clinical outcome but was closely related to fracture severity. A new classification based on the degree of talonavicular joint damage showed close correlation to clinical and radiologic outcome. Level of Evidence: Level IV, retrospective case series.

Ankle joint pressure changes in high tibial and distal femoral osteotomies: a cadaver study.

Aims To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint. Materials and Methods Varus and valgus malalignment of the knee was simulated in human cadaver full‐length legs. Testing included four measurements: baseline malalignment, 5° and 10° re‐aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra‐articular sensors captured ankle pressure. Results In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant. Conclusion The re‐alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus.

Current Swiss Techniques in Management of Lisfranc Injuries of the Foot

The outcome after Lisfranc injuries correlates with anatomic and stable reduction. The best surgical treatment, particularly for the ligamentous Lisfranc injuries, remains controversial. Recent publications suggest that the ligamentous injuries may benefit from primary partial Lisfranc arthrodesis. Most surgeons agree that an appropriate reduction is better and easier achieved by open reduction and stable temporary screw or dorsal plate fixation or by open primary partial arthrodesis than by closed reduction or Kirschner wire fixation. Despite correct surgical technique and postoperative management, symptom-free recovery is uncommon. This article outlines current techniques in the management of Lisfranc injuries and resultant postoperative outcomes in a level I trauma center.

Compression sonography for non-invasive measurement of lower leg compartment pressure in an animal model.

INTRODUCTION Compression ultrasound is a non-invasive technique allowing for qualitative visualization and quantitative measurements of mechanical tissue properties. In acute compartment syndrome (ACS), cadaver studies have proven that the intra-compartmental pressure (ICP) measured by compression sonography correlates with the ICP measured invasively. This study aimed to evaluate compression sonography for compartment pressure measurements in an animal model. MATERIAL AND METHODS The pressure in the anterior tibial compartment of 6 domestic pig legs was increased from baseline to 40mmHg in 5mmHg steps. Using compression sonography, the compartment diameter was measured without external pressure and during manual application of five levels of external pressure. The elasticity ratio (ER) was computed as the ratio of the compartment diameter with and without external pressure. At 40mmHg of external pressure the ERs at different ICP levels were compared using repeated ANOVA measurements. Post-hoc comparisons evaluated the lowest detectable ICP fulfilling the definition of ACS (ICP≥30mmHg) by starting from each pressure below 30mmHg (baseline, 20mmHg and 25mmHg, respectively). Receiver operator characteristic analyses defined ER limits with appropriate sensitivity and specificity to detect ACS. RESULTS The ER increased from 79.0% at baseline ICP to 89.3% at 40mmHg ICP. The ER at baseline and at 20mmHg ICP significantly differed from the ER at 30mmHg ICP (p=0.007 and 0.002, respectively); the ER at 25mmHg ICP significantly differed from the ER at 40mmHg ICP (p=0.001). An ER less than 87.1% had a sensitivity of 94.4% and a specificity of 88.9% to proper diagnosis of ACS. CONCLUSION Compression sonography might offer a non-invasive technique to guide treatment in cases of uncertain acute compartment syndrome. Further studies are needed to collect elasticity ratio data in humans and to clinically validate compression sonography for compartment pressure measurements.

The Pararectus approach provides secure access to the deep circumflex iliac vessel for harvest of a large sized and vascularized segment of the iliac crest

BACKGROUND The feasibility of harvesting a vascularized iliac crest utilizing the Pararectus approach was assessed in cadavers and then this new technique was implemented in a clinical case. METHODS Bilaterally in five cadavers the branches of both external iliac arteries were injected with colored silicone to assess their position to each other and to harvest a bone graft vascularized by the deep circumflex iliac artery (DCIA) through the Pararectus approach. This technique was implemented in a 68-years-old female patient, initially admitted to a level-I-trauma center after sustaining multiple injuries by falling from great height. For definitive treatment of a severely contaminated medially open (Gustilo-Anderson Type 3A) calcaneal luxation fracture (Sanders type IIIBC) in this patient a vascularized iliac crest autograft harvest by the Pararectus approach was used for reconstructive surgery. RESULTS The DCIA and the deep inferior epigastric vessels (DIEV: vascularizing the rectus abdominis muscle and main pedicle of the inferiorly based rectus abdominis myocutaneous flap) are very close on the lateral and medial border of the external iliac artery, respectively. As a consequence, the retrograde dissection of the DIEV towards the DCIA through the Pararectus approach made the dissection of the vascularized iliac crest more amenable, preserving both the lateral femoral cutaneous and the genitofemoral nerves. Four months after the surgery the patient was able to fully weight-bear in orthopedic shoes. Radiographs and CT scans showed correct hind foot alignment and bony integration of the vascularized iliac crest graft into the residual calcaneal body. CONCLUSION The Pararectus approach allowed for secure collection of large vascularized iliac grafts. The presented technique was successful as a salvage procedure in a clinical case with substantial bone loss after an open calcaneal fracture.