Case study: 5th metatarsal base fracture - Asnis JFX

A review by Kirk McCullough, MD

Patient history:

The patient is an 18 year old high school senior and multi-sport athlete with acute onset lateral forefoot pain while playing football. Upon questioning, he described a history of intermittent dull, aching pain over the lateral forefoot preceding the aforementioned incident without known history of prior injury, which he initially ignored.

Unfortunately, he reported acute worsening of his symptoms during a running play in the third game of the season, and an inability to walk without pain following that.

Assessment:

On presentation to clinic, he was noted to have an antalgic gait with significant pain on attempted weightbearing with his right foot. Weightbearing stance demonstrated no obvious malalignment. He was unable to perform a single limb stance secondary to pain. Seated examination noted asymmetric soft tissue swelling with minimal ecchymosis over the lateral forefoot, with focal tenderness to palpation at the 5th metatarsal base. Weight bearing radiographs demonstrated a metadiaphyseal fracture of the 5th metatarsal base with plantar lateral cortical thickening consistent with an acute on chronic stress fracture (Jones fracture).

After outlining risks and benefits of non-operative and operative treatment, the patient and his parents wished to proceed with surgery with the hopes of being able to return to football play for his senior season.

Figure 1: Pre-operation anteroposterior

Figure 2: Pre-operation oblique

Figure 3: Pre-operation lateral

Procedure/treatment:

Under anesthesia, the right lateral foot and ankle were prepped and draped in the usual manner. After appropriate positioning, c-arm fluoroscopy was utilized along with a guide wire placed on the skin to determine appropriate trajectory and incision placement along the lateral midfoot/hindfoot proximal to the 5th metatarsal base. Subsequently, a small ~1.5 cm incision was then made through skin only, and then blunt dissection with care for the local branches of the sural nerve was utilized to place the angled soft tissue protector onto the 5th metatarsal base to facilitate guidewire placement. Confirming appropriate positioning on multiple orthogonal radiographs, the guidewire was then advanced into the 5th metatarsal base and across the fracture. Once again, fluoroscopy was utilized and confirmed appropriate trajectory and placement on multiple views.

Next, the cannulated drill bit was utilized to enter the 5th metatarsal, and upon confirmation of entry into the metaphyseal region, was advanced across the fracture while on both reverse and oscillation to ream the fracture site and help maintain central location within the cancellous bone of the diaphysis. Sequential cannulated taps were then utilized to size the canal, noting appropriate capture of distal bone with the 6.0 mm tap. Length of the screw was then determined both with the cannulated tap and fluoroscopic sizing of the screw placed on the adjacent skin.

Next, utilizing a percutaneous bone marrow aspirate (BMA) system, iliac crest BMA was harvested from the ipsilateral crest, combined with a demineralized bone matrix (DBM) carrier, and then injected percutaneously at the fracture site both from an interosseous and subperiosteal location utilizing fluoroscopy.

Following this, a 6.0 × 44mm screw was then advanced across the fracture holding in-line axial compression along the 5th metatarsal. Noted compression of the fracture and capture of the head with the 5th metatarsal base was then confirmed both clinically and fluoroscopically. Final radiographs were then obtained. The screw entry site was then throughly irrigated and layered closure then performed, followed by placement of a sterile, soft tissue compression splint.

Discussion:

This case presents the unique challenge of an in-season athlete with an acute on chronic stress fracture and the desire to return to play on an accelerated timeline. These cases require a thorough discussion with the patient and their support structure including but not limited to, family members, coaches and trainers, on the risks and benefits of both operative and non-operative treatment, particularly when aggressive timelines for return to play are desired. Specific to hardware utilized in cases of Jones fracture fixation with an accelerated rehabilitation, the hardware must be strong enough to resist the stress and strain forces associated with early weightbearing while fracture healing is incomplete, yet not be too rigid so as to prevent natural fracture healing from taking place.

Figure 4: Intraoperative Figure 5: Intraoperative anteroposterior

Figure 6: Intraoperative lateral Figure 7: Intraoperative oblique

Figure 8: Postoperative anteroposterior five weeks later

Five weeks post operative

Figure 9: Postoperative oblique five weeks later

Post-operative clinical outcome:

In this case, the athlete was able to return to football game competition at seven weeks post-operative. No recurrence of lateral forefoot pain was reported.

Follow-up:

Immediately following the procedure, the athlete was made non-weight bearing with strict edema control precautions. He was placed in a boot one week post-operative to begin range of motion exercises and initiated progressive weightbearing within his boot at two weeks post-operative. Transition to accommodative shoewear with custom orthotics and progressive impact training with both aquatic and anti-gravity treadmill use was started at four weeks. Ultimately, the patient returned to football competition at seven weeks post-operative. No recurrence of lateral forefoot pain was reported and the patient was able to complete his senior football season playing both running back and defensive back for the team. Subsequently, he went on to play basketball immediately following the season and continued to note no recurrence of lateral forefoot symptoms.

Conclusion:

The Asnis JFX system provided an excellent option for fixation of 5th metatarsal base fractures in an athlete desiring an accelerated return to play. In this particular case, it provided not only sufficient compression of the fracture upon initial fixation, but also demonstrated ability to withstand the forces necessary to complete an accelerated rehabilitation schedule while bone fracture healing continues to mature.

Figure 10: Postoperative seven weeks later

Figure 11: Postoperative ten weeks later

Figure 13: Postoperative ten weeks later

Figure 12: Postoperative ten weeks later

Seven weeks post operative

Ten weeks post operative

A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery. The information presented is intended to demonstrate the breadth of Stryker product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any Stryker product. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area. Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Asnis, Stryker. All other trademarks are trademarks of their respective owners or holders.

Content ID: AS-CS-1, 03-2017Copyright © 2017 Stryker

Foot & Ankle