The Evolution Of Herbert Screw In Radial Head Surgery

The Herbert screw is a variable pitch cannulated screw made from titanium that was invented by Timothy Herbert. It is a type of headless compression screw used to treat radial head fractures. The screw has a differential pitch that provides rigid fixation with compression and has no protruding head. Its small diameter means that more than one screw can be used. The Herbert screw is designed to be embedded in the bone without causing tissue irritation.

Herbert screw osteosynthesis

The Herbert screw osteosynthesis procedure can be performed using a freehand or percutaneous technique, without the need for a jig. This approach preserves the inter- and intracarpal ligaments, vascular supply, and articular surfaces of the scaphoid. Early functional movement can be initiated as early as the first postoperative day, as the osteosynthesis is sufficiently stable.

The Herbert screw was invented by Timothy Herbert and is one of the earliest designs of headless compression screws. It is a variable pitch cannulated screw, which means it has a differential thread pitch between the proximal and distal ends, allowing for compression and stability at the fracture site. The headless design ensures that the screw is completely embedded within the bone, reducing the risk of tissue irritation.

The osteosynthesis procedure using the Herbert screw has been applied in various types of trauma surgery, including scaphoid, radial head, and mandibular angle fractures. It has also been used in osteochondritis dissecans and small joint arthrodesis. The screw is available in different sizes, ranging from 2.5 mm to 6.5 mm in diameter, with corresponding lengths ranging from 8 mm to 120 mm.

The Herbert screw osteosynthesis technique offers several advantages over traditional methods. It provides rigid fixation with compression, has no protruding head, is easily introduced, and has a small diameter that allows for the use of multiple screws if needed. This procedure aims to restore the exact form, length, and normal position of the scaphoid in relation to the other carpal bones, preventing non-unions, arthrosis, and other late complications.

Radial head fractures

Symptoms

The most common symptoms of a radial head fracture include:

• Pain on the outside of the elbow
• Swelling in the elbow joint
• Difficulty bending or straightening the elbow, accompanied by pain
• Inability to turn or difficulty turning the forearm (from palm up to palm down or vice versa)

Types of Fractures

Doctors classify fractures according to the degree of displacement and the number of fragments. Treatment is determined by the type of fracture:

• Type I fractures are small cracks, and the bone pieces remain fitted together. They may not be visible on initial X-rays.
• Type II fractures are slightly displaced and involve a larger piece of bone. If displacement is minimal, treatment may involve wearing a sling or splint.
• Type III fractures have multiple broken pieces of bone that cannot be put back together. Surgery is always required to either fix or remove the broken pieces.

Treatment

The treatment options for radial head fractures include:

• Nonsurgical treatment: For most isolated fractures, a sling or splint may be used for a few days, followed by early and gradual exercises to restore movement.
• Surgical treatment: If fragments are large and out of place, surgeons may attempt to hold the bones together with screws or a plate and screws. If this is not possible, the broken pieces of the radial head may be removed.
• Herbert Screw: The Herbert screw is a type of headless compression screw used to treat radial head fractures. It provides rigid fixation with compression and is easily introduced due to its small diameter.

Post-Treatment Care

Even after treatment, some loss of movement in the elbow may occur. Patients will typically be prescribed exercises to restore movement and strength before resuming full activities. In some cases, a second surgery may be required to remove scar tissue.

Advantages and disadvantages

Advantages of the Herbert Screw

The Herbert screw is a variable pitch, cannulated screw typically made from titanium for its biocompatible properties. It is intended to remain in the patient indefinitely and is one of the earliest designs of headless compression screws. Its advantages include:

• The headless design means the screw is completely embedded in the bone, causing minimal tissue irritation and allowing for a more anatomical fit.
• Precise placement of the screw is ensured through cannulation.
• The Herbert screw can be used to repair broken bones and perform osteotomies in specific cases.
• It can be used to treat fractures of the scaphoid, capitellum, radial head, and osteochondral tissue.
• It provides rigid fixation and has an auto-compression effect.
• The headless design allows it to be countersunk beneath the surface of the articular cartilage.
• It can be used to treat mandibular fractures, with no intraoperative or postoperative complications reported in one study.

Disadvantages of the Herbert Screw

The disadvantages of the Herbert screw include:

• It may require an additional surgery for removal.
• If the fragment settles or breaks, the screw may become proud, leading to injury of the opposing articular surface.
• It can be difficult to find screws that are the right size and shape for different bone types and injury structures.
• Implanting headless Herbert screws demands surgical accuracy, and surgeons must be trained to implant and compress screws without injuring surrounding tissues or structures.
• Herbert screws may be more expensive than typical fixing processes.

Surgical procedure

The Herbert screw is a headless, cannulated screw invented by Timothy Herbert. It is made from titanium and was first introduced in 1978. The screw is biocompatible and intended to remain in the patient's body indefinitely.

The Herbert screw is used to treat fractures of the radial head, as well as fractures of the scaphoid, capitellum, and osteochondral tissue. It can also be used for osteotomies, osteochondritis dissecans, and facet arthrodesis. The screw provides rigid fixation with compression and has a small diameter, allowing for the use of multiple screws if needed.

The surgical procedure for implanting a Herbert screw can be outlined as follows:

• Preparation and Guide Wire Insertion: The surgeon selects the appropriate guide wire and drill guide for the chosen Herbert screw diameter. A small incision is made, and the guide wire is fed through the drill guide into the bone to the desired depth and position. Fluoroscopy is used to ensure the correct placement of the guide wire.
• Screw Length Determination: A direct measuring device is used to determine the depth of the guide wire in the bone, which helps select the appropriate screw length.
• Drilling and Tapping: The correct drill size is chosen for the Herbert screw diameter. The drill is fed over the guide wire and drilled to the desired depth. Fluoroscopy is used again to ensure correct alignment and depth. Then, a countersink is passed over the guide wire to create a space for the screw head.
• Screw Insertion: The Herbert screw is selected based on the previously measured depth. It is passed over the guide wire and advanced into position using a cannulated driver. Compression is applied by rotating the driver clockwise until all distal threads have engaged the bone. Fluoroscopy is used once more to ensure the correct positioning of the screw.
• Post-insertion Care: After the surgery, patients undergo a recovery period with close monitoring to ensure positive outcomes.

Clinical Results and Patient Outcomes:

The use of Herbert screws in orthopedic surgery has shown positive clinical results. The compression achieved by the screw results in better fracture reduction and increased stability, leading to improved patient recovery and healing. Patients often experience less pain, quicker recovery, and improved joint function compared to traditional fixing methods. The Herbert screw's ability to align and fix the body safely while minimising soft tissue irritation contributes to its success.

Alternative methods

The Herbert screw is a variable pitch cannulated screw that is often made from titanium. It is used to treat radial head fractures and is one of the earliest designs of headless compression screws.

An alternative to the Herbert screw is the Acutrak screw. While there have been several biomechanical studies comparing the two, there have been relatively few clinical trials. One clinical trial compared 22 patients treated with Herbert screws and 23 patients treated with Acutrak screws for scaphoid nonunions. It found no difference in union rate or time to union. However, the Herbert screw group had a lower rate of screw removal due to more complete visualisation and appropriate screw length.

Another alternative method is the use of K-wires for internal fixation. However, this does not produce rigid fixation and often leads to distraction, continued immobilisation, and the need for a second operation for hardware removal.

Standard screws can also be used for radial head fractures, but they are prone to backing out into the joint if there is any settling at the fracture site.

For unstable fracture patterns, plating can be used as an alternative to screws. This may be the case in unstable fracture patterns, following high-energy injury with associated carpal dislocations, or in cases of nonunion.

Frequently asked questions