External fixation indications and patient selection

Nonunion of the femoral shaft associated with limb shortening treated with a combined technique of external fixation over an intramedullary nail versus the Ilizarov method

INTRODUCTION

Post-traumatic nonunion of the femur remains a challenging problem even for experienced orthopedic surgeons. The main question is the choice of the optimal surgical tool.

MATERIALS AND METHODS

Management of 20 patients with nonunion of the femoral diaphysis associated with anatomical shortening was retrospectively analyzed. Group A (n = 14) was treated with a hybrid technique that combined the Ilizarov external fixation and intramedullary nailing. The Ilizarov bone transport was used in group B (n = 6). Patients of both groups had aseptic post-traumatic nonunion. Mean shortening was 4.5 ± 0.4 cm in group A and 4.8 ± 1.0 cm in group B (p = 0.459959).

RESULTS

Union was achieved in 85.7% of group A and 100% of group B patients. External fixation was repeated in two cases of group A and achieved consolidation. Deep infection developed in one case of group A after 15 months post-frame with the nail in. It was resolved by nail removal, surgical debridement and external fixation. Limb shortening was fully eliminated in eleven cases of group A and four patients of group B. The average duration of distraction was 35.3 ± 1.7 days in group A and 47.8 ± 9.3 days in group B. The total duration of external fixation was 49.1 ± 3.5 and 177.2 ± 21.9 days with an external fixation index of 13.1 ± 1.2 and 52.4 ± 6.4 days/cm, respectively. Distraction regenerate consolidated in all the cases.

CONCLUSION

Hybrid technique provides bone union with compensation of limb shortening and reduces the treatment period as compared with the Ilizarov method used alone. However, deep infection may happen.

The results of bone deformity correction using a spider frame with web-based software for lower extremity long bone deformities

Aim: To present the functional and radiological results and evaluate the effectiveness of a computer-assisted external fixator (spider frame) in patients with lower extremity shortness and deformity.

Materials and methods: The study comprised 17 patients (14 male, 3 female) who were treated for lower extremity long bone deformity and shortness between 2012 and 2015 using a spider frame. The procedure’s level of difficulty was determined preoperatively using the Paley Scale. Postoperatively, the results for the patients who underwent tibial operations were evaluated using the Paley criteria modified by ASAMI, and the results for the patients who underwent femoral operations were evaluated according to the Paley scoring system. The evaluations were made by calculating the External Fixator and Distraction indexes.

Results: The mean age of the patients was 24.58 years (range, 5–51 years). The spider frame was applied to the femur in 10 patients and to the tibia in seven. The mean follow-up period was 15 months (range, 6–31 months) from the operation day, and the mean amount of lengthening was 3.0 cm (range, 1–6 cm). The mean duration of fixator application was 202.7 days (range, 104–300 days). The mean External Fixator Index was 98 days/cm (range, 42–265 days/cm). The mean Distraction Index was 10.49 days/cm (range, 10–14 days/cm).

Conclusion: The computer-assisted external fixator system (spider frame) achieves single-stage correction in cases of both deformity and shortness. The system can be applied easily, and because of its high-tech software, it offers the possibility of postoperative treatment of the deformity.

Standards of external fixation in prolonged applications to allow safe conversion to definitive extremity surgery: the Aachen algorithm for acute ex fix conversion

External fixation has become an important tool in orthopedic surgery. Technology has improved the design and material as well as the construct of the fixator. As most patients are converted from external fixation to definite stabilization during later clinical course, prevention of complications such as infection is of high importance. Based on the current literature, principles of temporary external fixation were summarized. We focused on minimizing the risk of infection and introduce a standardized algorithm how to proceed when converting from external to internal fixation, which also was examined for effectiveness.

An alternative technique for transosseous calcaneal pinning in external fixation

The authors describe a technique in which two 5.5-mm pins are inserted from the posterior aspect of the calcaneus and advanced anteriorly on a slightly convergent vector. The 2 points of fixation, with a 5/8 ring, provide a "steering wheel" effect allowing for leverage and control of the hindfoot and ankle. The construct also allows for offloading of the posterior calcaneus.

Bone transport and compression-distraction in the treatment of bone loss of the lower limbs

A clinical series of 17 adult patients operated due to significant by bone loss of the long bones of the lower extremity (3 femurs and 11 tibias), is presented. Their management consisted of 6 bone transports (6 tibias) and 11 compression distraction procedures (3 femurs and 8 tibiae) using monolateral external fixators. Bone loss ranged from 3.9 cm to 14.7 cm. Mean healing time was 301 days with a mean healing index of 45.6 days for cm of lengthening achieved. The clinical and radiological results were excellent in 9, good in 6 and fair in 2 patients according to the utilised criteria of assessment. Consolidation was achieved in all but one patient who developed an aseptic stiff non-union. Two patients developed residual limb-length discrepancy less than 1.5 cm, three tibias ended up with less than 5° of valgus deviation. In two cases the half-pins were re-inserted due to early loosening. In two cases reoperation was needed for late bending of the callus after fixator removal. Three cases of bone transport and 1 case of compression distraction needed bone grafting at the docking site. Bone transport and compression-distraction are effective methods for treating bone loss in the lower extremity. It is suggested that the compression-distraction technique is preferable, since this is associated with a lower incidence of complications than bone transport procedures. The deciding factor, however, is the actual extent of the bone loss.

A rare variant of tibial hemimelia and its treatment

Tibial hemimelia is a rare condition. We present a variant of tibial hemimelia not reported in literature before. In this variant, we were able to successfully salvage the limb with excellent function to carry on with life.

Use of chlorhexidine-impregnated patch at pin site to reduce local morbidity: the ChIPPS Pilot Trial

Pin tract infection is one of the most common complications associated with the use of external fixation. While some studies have identified the potential benefit of chlorhexidine gluconate-impregnated polyurethane dressings to reduce the incidence of catheter-related bloodstream infections, we are unaware of any published studies that evaluate the effectiveness of similar technologies in reducing the risk for external-fixation-related pin tract infections. Therefore, the purpose of this study was to evaluate the effectiveness of chlorhexidine gluconate-impregnated polyurethane dressing in reducing percutaneous-device-related skin colonisation and local infections. In this initial retrospective cohort, data were abstracted for two groups of consecutive patients undergoing surgery involving external fixation at an interdisciplinary foot and ankle surgical unit. All patients received surgical treatment of their foot/ankle pathology along with application of a hybrid external fixator. Twenty patients (45% male, age 54.5 +/- 3.69 years) received chlorhexidine gluconate-impregnated polyurethane dressing and twenty (55% male, age 55.8 +/- 3.22 years) received standard pin care. There was a significantly higher rate of pin tract infection in patients who received standard pin care compared with those who received chlorhexidine gluconate-impregnated polyurethane dressings (25% versus 0%, P = 0.047). There was no significant difference in any of the descriptive study characteristics (age, gender, diabetes and presence of neuropathy). The results of this initial study suggest that chlorhexidine gluconate-impregnated polyurethane dressing may be effective to reduce the incidence of pin tract infections and help decrease morbidity associated with external fixation.

A technique to protect external fixation devices

The indications for external fixation in foot and ankle surgery are expanding and now include the use on patients with significant comorbidities. Protecting the contralateral limb from inadvertant injury is important especially in patients with diabetes where the contralateral limb is already "at risk". The authors describe a simple and inexpensive technique to protect the external fixator and the contralateral limb from potential injury.

Mechanical testing of seven fixation methods for generation of compression across a midtarsal osteotomy: a comparison of internal and external fixation devices

The purpose of this study was to assess 7 methods of fixation for a midtarsal osteotomy. Polyurethane foam models (N = 6) and cadaver specimens (N = 4-7) were used to examine the force generated by the different constructs of fixation. A midtarsal osteotomy was performed on each specimen in the test groups. The osteotomies were fixated either with 2 parallel 0.062-in Kirschner wires and 40-mm-long, 4-mm partially threaded, cancellous, cannulated titanium screws, an external ring fixator (frame), a frame with wires tensioned (tension), a frame with wires tensioned and compressed toward the osteotomy (tension and compression), a frame with tension, compression, and parallel Kirschner wires, or a frame with tension, compression, and two 4.0 cannulated parallel screws, respectively. Each model was fixated, and the force generated by the construct across the osteotomy was recorded via the use of pressure-sensitive film. Statistical analysis of the data in the polyurethane foam group determined that the use of frame with tension, compression, and two 4.0 parallel cannulated screws was statistically superior to 1) frame, 2) frame with tension, 3) 2 parallel Kirschner wires, 4) two 4.0 cannulated parallel screws, and 5) frame with tension and compression. A cadaver study determined that the frame with tension, compression, and 2 parallel Kirschner wires was statistically superior to 1) frame and 2) two parallel Kirschner wires. These findings suggest that there is a difference in the force generated by the type of fixation construct across a midtarsal osteotomy.

Management of complex open fracture injuries of the midfoot with external fixation

Ten patients (11 feet) with severe, high-velocity, open injuries to the midfoot were treated with uniplanar external fixation. The mean patient age was 38 years. Five wounds measured >10 cm, and 3 had extensive degloving of the foot extending into the lower leg. All had grossly comminuted fractures of the tarsal and metatarsal bones: 9 patients had a fractured cuboid; 6 had a fractured navicular; 7 had a fractured cuneiform; and all had metatarsal fractures. Lisfranc joint dislocations were present in 7 feet, and intertarsal dislocations were seen in 3 cases. Six patients underwent split-thickness skin grafting, and 1 required a myocutaneous flap. The average duration of fixator use was 9 weeks (range, 6-15 weeks). Clinically, patients were evaluated 1 year after fixator removal for any residual pain in the foot, ability to stand on tiptoe, presence of a limp, deformity of an arch, and range of motion at the ankle, subtalar, and metatarsophalangeal joints. Each parameter was graded as good, fair, or poor. All patients had sensate plantigrade feet, with 2 patients who experienced pain on weight bearing, 5 who had difficulty standing comfortably on tiptoe, and 2 who limped because of pain. Three patients exhibited flatfoot deformity, whereas 4 had cavus deformity. All demonstrated stiffness at the midfoot and restriction of subtalar and forefoot motion, with 5 also having restricted ankle motion. Radiographically, all fractures were healed at the time of follow-up; 4 were malunited, with 1 demonstrating ankylosis across the tarsometatarsal joint. These results suggest that crush injuries to the midfoot often result in persistent morbidity despite early comprehensive management with external fixation.