Cannulated Screw Prominence in Tension Band Wiring of Patella Fractures Increases Fracture Gapping: A Cadaver Study.

BACKGROUND: Transverse patella fractures are often treated with cannulated screws and a figure-of-eight anterior tension band. A common teaching regarding this construct is to recess the screws so that their distal ends do not protrude beyond the patella because doing so may improve biomechanical performance. However, there is a lack of biomechanical or clinical data to support this recommendation. QUESTION: In the treatment of transverse patella fractures, is there a difference between prominent and recessed cannulated screw constructs, supplemented by tension banding, in terms of gap formation from cyclic loading and ultimate load to failure? METHODS: Ten pairs of fresh-frozen cadaver legs (mean donor age, 72 years; range, 64-89 years) were randomized in a pairwise fashion to prominent or standard-length screws. In the prominent screw group, screw length was 15% longer than the measured trajectory, resulting in 4 to 6 mm of additional length. Each patella was transversely osteotomized at its midportion and fixed with screws and an anterior tension band. Gap formation was measured over 40 loaded flexion-extension cycles (90° to 5°). Ultimate load to failure was assessed with a final monotonic test after cyclic loading. Areal bone mineral density (BMD) of each patella was measured with dual energy x-ray absorptiometry (DEXA). There was no difference in BMD between the recessed (1.06 ± 0.262 g/cm) and prominent (1.03 ± 0.197 g/cm) screw groups (p = 0.846). Difference in gap formation was assessed with a Wilcoxon Rank Sum Test. Ultimate load to failure and BMD were assessed with a paired t-test. RESULTS: Patella fractures fixed with prominent cannulated screws demonstrated larger gap formation during cyclic loading. Median gap size at the end of cyclic loading was 0.13 mm (range, 0.00-2.92 mm) for the recessed screw group and 0.77 mm (range, 0.00-7.50 mm) for the prominent screw group (p = 0.039; 95% confidence interval [CI] difference of geometric means, 0.05-2.12 mm). There was no difference in ultimate failure load between the recessed screw (891 ± 258 N) and prominent screw (928 ± 268 N) groups (p = 0.751; 95% CI difference of means, -226 to 301 N). Ultimate failure load was correlated with areal BMD (r = 0.468; p = 0.046). CONCLUSIONS: In this cadaver study, when using cannulated screws and a figure-of-eight tension band to fix transverse patella fractures, prominent screws reduced the construct's ability to resist gap formation during cyclic loading testing. CLINICAL RELEVANCE: This biomechanical cadaver study found that the use of prominent cannulated screws for the fixation of transverse patella fractures increases the likelihood of interfragmentary gap formation, which may potentially increase the risk of fracture nonunion and implant failure. These findings suggest that proximally and distally recessed screws may increase construct stability, which may increase the potential for bony healing. The findings support further laboratory and clinical investigations comparing recessed screws supplemented by anterior tension banding with other repair methods that are in common use, such as transosseous suture repair.

Open Reduction and Internal Fixation of the Femoral Head via the Smith-Petersen Approach.

Pipkin described femoral head fractures in the 1950s, but controversy still exists regarding indications for surgery and approaches for operative treatment of femoral head fractures. Clear indications for operative intervention include inability to reduce the hip with closed methods, a nonconcentric reduction, fracture fragments within the articulating surface of the hip, and associated injuries (acetabulum and femoral neck fractures) with their own indications for surgery. The anterior approach described by Smith-Petersen has been modified (using only the distal portion) and used to visualize, clean, reduce, and fix these fractures with and without anterior dislocation of the hip.

ORIF Pilon via Posteromedial and Anterolateral Approaches.

Tibial pilon fractures are complex injuries of soft tissue and bone that challenge patients and surgeons. Outcomes following this injury are guarded, and complications are frequently reported. Soft-tissue compromise at the time of injury is potentially amplified with surgical trauma, necessitating thorough evaluation, preoperative planning, and expertise to minimize complications and maximize outcomes. Understanding angiosome anatomy and typical fracture patterns (and their variations) allows for design of surgical tactics that accomplish these goals.

Distal Tibial Intramedullary Nailing Using an Extraarticular, Lateral Parapatellar Approach in the Semiextended Position.

Semiextended positioning can improve the surgeon's ability to obtain, maintain, and fluoroscopically evaluate a fracture reduction when performing fixation with an intramedullary nail, especially in fractures at the proximal and distal ends. Furthermore, this position allows for evaluation of instrument placement, including the start point, without moving the fluoroscopic unit into extremes of angulation or compromising the quality of the beam orientation. The intraarticular suprapatellar approach has been described as a soft tissue approach to maintain the leg in a position that would not complicate management of these fractures, especially those in the proximal third of the tibia. A semiextended extraarticular soft tissue approach to the start point was described by Kubiak et al, and the lateral parapatellar version has become commonly used on the Orthopaedic Trauma Service at Washington University in Saint Louis. This video demonstrates advantages of semiextended positioning while performing reduction and intramedullary nail fixation for distal tibia fractures. This lateral parapatellar approach can be performed without specialized instrumentation, results in precise establishment of the start point and completion of the fixation without injury to the knee.

Ankle Spanning External Fixator Application.

A 2-stage approach to treatment of tibia pilon fractures was reported in the 1990s and popularized over the ensuing decade to help avoid catastrophic soft-tissue complications experienced with one-stage open reduction and internal fixation. This approach can be expanded to the treatment of other high-energy injuries of the hind foot, with variation in external fixator application as needed. Key factors to maximize the utility and decrease complications of the external fixation stage include the following: (1) anatomic reduction of the talus under the long axis of the tibia in the coronal and sagittal planes, (2) strategic application of Schantz pins to resist deforming forces resulting from the injury, and (3) external fixation outside the zone of injury and definitive surgical treatment. This video demonstrates concepts and tactics to obtain and maintain fracture reduction with an external fixator with examples of a complex combined plafond and talus injury, as well as a more typical Orthopaedic Trauma Association/Arbeitsgemeinschaft fur Osteosynthesefragen C-type pilon fracture.

Intraoperative Video Production With a Head-Mounted Consumer Video Camera.

The use of high-definition video in surgical education is becoming increasingly popular. Because of the availability of relatively inexpensive, consumer-grade video cameras, surgeons with minimal video production experience can produce high-quality surgical videos. A number of video capture methods are available, with varying degrees of production quality, economic constraint, and level of attention required from the operating surgeon. The accompanying video provides an overview of the advantages and disadvantages of several options and describes a technique for capturing intraoperative video with the use of a head-mounted, consumer video camera.

Retrograde Femoral Nailing Using Percutaneous Reduction Techniques.

Femoral shaft fractures are commonly treated with closed reduction and reamed intramedullary nailing. However, some reductions are difficult to obtain or maintain, especially in muscular or large patients. When closed methods fail to achieve reduction, percutaneous techniques are extremely useful. In addition, the use of either permanent or temporarily placed blocking implants offer a minimally invasive option for improving sagittal and coronal plane alignment. In the accompanying video, we describe our method of percutaneous reduction techniques in the setting of a comminuted femoral shaft fracture treated with a retrograde femoral intramedullary nail.

Open Reduction Internal Fixation of a Bimalleolar Ankle Fracture With Syndesmotic Injury.

Rotational ankle fractures are incredibly common, resulting in a wide spectrum of bony and ligamentous injury patterns. After open reduction of an ankle fracture, the treating surgeon must always evaluate syndesmotic stability. If the syndesmosis is determined to be unstable, a reduction of the distal tibiofibular joint should be performed. Failure to adequately identify and treat injuries to the syndesmosis may result in continued ankle instability and poor patient outcomes. Lateral fluoroscopic images are necessary to assess a closed reduction of the syndesmosis before stabilization, although the accuracy of this tool has been questioned in several studies. Significant controversy surrounds many aspects of this injury and its treatment, including methods of diagnosis, ideal reduction clamp positioning, diameter and number of syndesmotic screws, and number of tibial cortices to be engaged. In the accompanying video, we describe our approach for the treatment of a bimalleolar ankle fracture with syndesmotic injury, using a posterior fibular plate and single tricortical syndesmotic screw.