Taking Advantage Of The Versatility Of Hook Plates

Fracture management can be a large part of any foot and ankle surgical practice. When necessary, open reduction and internal fixation of displaced fractures can produce good clinical results.
One option for fixation of these fractures can be the use of a hook plate. Surgeons commonly utilize hook plates for smaller fracture fragments that are not amenable to typical screw fixation. They can provide stability to comminuted fracture fragments, prevent rotation and apply compressive forces across fracture sites.¹ The plate serves to purchase a fracture fragment with its prongs and reduce the fragment to the diaphyseal portion of bone.²

One can use hook plates in various aspects of foot and ankle surgery. Some of the most common uses are for fractures involving the fifth metatarsal base, the navicular tuberosity, the medial malleolus and the distal fibula.

Multiple shapes and sizes of hook plates are currently available for use. However, when necessary, the surgeon can create a hook plate by removing one end of a 1/3 tubular plate and then bending the remaining aspect to create prongs. After one has anatomically reduced the fracture fragment and held it in place with provisional fixation, one may tamp the prongs into the fracture fragment and secure the plate with the use of screws.² The surgeon may also utilize the prongs of the plate to assist with the fracture reduction. In addition, many hook plates contain holes for screw placement, which provides dynamic compression across the fracture site.

How Hook Plates Can Be Beneficial For Fifth Metatarsal Fractures
Hook plate fixation is an effective surgical method for Lawrence classification zone I and II displaced fifth metatarsal base fractures or comminuted small fragment fractures.¹ Choi and colleagues reported positive results in treating zone I and II fractures in 17 patients.¹ It is well known that the fifth metatarsal has poor blood supply and many times, this can lead to delayed union and non-union, therefore necessitating open reduction with fixation.³ Intramedullary screw fixation has become a common method of fixation for these fractures. However, it can be technically demanding and difficult to achieve adequate reduction with osteopenic bone, comminuted or small fracture fragments.

Utilization of a hook plate is a simple technique, which provides compression across the fracture site and allows for early weightbearing. The hook plate achieves tension banding of a fifth metatarsal fracture in the same fashion as steel monofilament and K-wires.

In a study by Lee and colleagues, 19 patients, 12 with zone I and seven with zone II fifth metatarsal fractures, had treatment with locking compression distal ulna hook plates.⁴ Using clinical and radiographic assessment with the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scoring system, the study authors found the mean score improved from 26 preoperatively to 94 postoperatively at the final follow-up. Bony union occurred at an average of 7.4 weeks. Patients were partially weightbearing at 3.6 weeks, fully weightbearing on average at 6.6 weeks and returned to full activity at 11.2 weeks.
The results are comparable to those with other techniques surgeons use to treat these fractures. The authors of this study suggest that one should consider this locking compression hook plate as an alternative treatment of multifragmentary, osteoporotic and tuberosity avulsion (zone I) fifth metatarsal base fractures.

It is the senior author’s experience that partial weightbearing in a fracture walker or controlled ankle motion (CAM) walker can occur earlier than 3.6 weeks postoperatively when using a locking hook plate for fixation.

What You Should Know About Hook Plates And Ankle Fractures
Hook plates can also facilitate surgical correction of small fragment medial and lateral malleolus fractures not amenable to traditional screw fixation. Surgeons can use a hook plate to provide compression across a transverse or very distal lateral malleolus fracture as well as stability to a medial malleolus fracture. The prongs of the plate act like a blade plate, providing more rotational stability than that provided by screws alone.⁵

Panchbhavi and coworkers studied the use of hook plates with syndesmotic screw fixation for the treatment of osteoporotic ankle fractures.⁵ Sixteen patients with an average age of 71.4 years had a hook plate/syndesmotic screw combination and 15 patients with an average age of 71.9 years had fixation of their ankle fracture with standard AO/Association for the Study of Internal Fixation (ASIF) principles with no syndesmotic screws. At an average follow- up of 15.8 months, patients completed a mailed questionnaire with the Olerud-Molander ankle score and the AOFAS ankle-hindfoot scale. Both scoring scales showed improvement of functional outcome. The AOFAS post-op score in the group using standard fixation was 65 and the AOFAS post-op score for the group using hook plate fixation was 77. This technique provides stable fixation for osteoporotic ankle fractures in the elderly patient until achieving union with good clinical scores.⁵

Addressing Small Bone Fractures
Surgeons can also use hook plate fixation to treat small bone fractures such as navicular, cuneiform and phalangeal fractures. According to Tonogai and colleagues, toe fractures are among the most common lower extremity fractures and fracture-dislocation of a toe is a severe injury with an uncertain outcome.⁶ The study authors report on a 56-year-old female who sustained a displaced right third toe intra-articular fracture. Surgeons fixated the fracture with a hook plate gripping the dorsal lip of the fracture fragment. At the one-year follow up, the patient had active range of motion of the toe to 35 degrees and the patient was pain-free with no complaints.   

In Conclusion
Hook plates can be very useful for any foot and ankle surgeon. The plate can provide stability to small fracture fragments, including intra-articular fractures. Hook plates also are very effective in treating patients with osteopenic bone, comminuted fractures and fractures not amenable to traditional types of fixation. In certain circumstances, hook plates may also allow for early weightbearing. Do not overlook the versatility of hook plates in fixating fractures of any bone in the lower extremity. 

Dr. Cook is the Director of Podiatric Medical Education at University Hospital in Newark, N.J. He is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Stuto is is a first-year resident at University Hospital in Newark, N.J.

References

1. Choi JH, Lee KT, Lee YK, Lee JY, Kim HR. Surgical Results of zones 1 and 2 fifth metatarsal base fractures using hook plates. Healio Orthopedics. 2013; 36(1):e71-e74.
2. Carpenter B, Garrett A. Using a hook plate as alternative fixation for fifth metatarsal base fracture. J Foot Ankle Surg. 2003; 42(5):315-316.
3. Smith JW, Arnoczky SP, Hersh. The intraosseous blood supply of fifth metatarsal: implications for proximal fracture healing. Foot Ankle. 1992; 13(3):143-152.
4. Lee SK, Park JS, Choy WS. Locking compression plate distal ulna hook plate as alternative fixation for fifth metatarsal base fracture. Eur J Orthop Surg Traumatol. 2013; 23(6):705-713.
5. Panchbhavi V, Mody M, Mason W. Combination of hook plate and tibial pro-fibular screw fixation of osteoporotic fractures: a clinical evaluation of operative strategy. Foot Ankle Int. 2005; 26(7): 510-515.
6. Tonogai I, Hamada Y, Kashima M, Takahashi M, Kanematsu Y, Henmi T. Pins and rubber band traction system and osteosynthesis with a hook plate for the treatment of old fracture dislocation of a toe. Foot Ankle Spec. 2011; 4(1):42-44.

For further reading, see “A Closer Look At Fixation For Fifth Metatarsal Fractures” in the September 2012 issue of Podiatry Today.