We found the percutaneous pinning with cemented K-wire frame could prevent radioproximal redisplacment of the fragment and radioproximal wire shift in type B1 DRFs; and prevent fragment rotational redisplacement in the sagittal plane in types A2 and A3 DRFs. Moreover, the system effectively maintains the radius height. The minimally invasive technique is reliable with minimal complications, resulting in satisfied outcomes.
DRFs are often caused by falling and landing on an outstretched hand 21. The treatment strategies for DRFs are generally debated 22. Surgeons’ preferences, fracture types, combined injuries and morbidity, complications, and patient factors (lifestyle, age, mental attitude, social support, comorbid conditions, and compliance with treatment) influence the options 23. Usually, types A2, A3, B1, and B2 (AO/OTA classification) fractures can be treated with a splint, cast, plate and screw system, external fixator, or K-wires, or combined these 3, 24, 25. A splint or plaster cast is commonly used for up to 4 to 6 weeks to immobilize the fracture in place while healing occurs 26. For unstable fractures, open reduction and internal fixation may be indicated 27. The reported complication (loss of fixation, tendon irritation and rupture caused by implants, and wound infection) rates of plating are as high as 3–27% depending on the fixation techniques used 28.
DRFs can be treated with percutaneous screw fixation 29. Transverse fractures can be fixed with cross screws 30. However, for oblique fractures, the crews should be positioned perpendicular to the fracture line 31. Otherwise, screw compression generates a shifting force, resulting in redisplacment. For comminuted fractures, screw compression may shorten the radius.
Franceschi et al 32 performed a systematic review on plating versus pinning for the treatment of DRFs. They found plating is associated with higher rates of tendon irritation (wrist pain, carpal tunnel syndrome, endonitis, and tenosynovitis) caused by the plates. In comparasion, pinning is associated with higher rates of tendon and neurovascular injuries (temporary paraesthesia, nerve irritation, superficial infections, wire migration, and loss of reduction) due to improper wire placement. However, the comparison based on types A1 to C3 DRFs may not reflect the actual outcomes because plating is more likely used in complex fractures (types B3 to C3). Nevertheless, decreasing the complications of pinning is a laudable goal.
There are many percutaneous pinning techniques (e.g., two wires, three or more wires, and Kapandji-technique) for DRFs 4. Typically, one or two K-wires are introduced from the tip of the radial styloid (radial styloid window). More K-wires can be added through 1,2 tendon interseptum (between 1 and 2 compartments on the dorsal wrist), 2,3 interseptum, and 4,5 interseptum. However, identifying the tendon intersepta and achieving optimal wire position are difficult 6. Moreover, oblique and cross pinning can effectively stabilize transverse fractures because stability depends on the intact of the proximal fragment 32. However, the support is compromised in oblique and comminuted fractures 7. According to the early anatomical studies, there are no important structures in the radial aspect of distal 1/3 radius, where K-wires can be safely introduced 29. A cement block connects all K-wires to form a frame, preventing wire migration. Thus, a relatively rigid fixation can be achieved, which allows an early range of motion exercise in a splint.
In type B1 DRFs, the distal fragment tends to redisplaced radioproximally, and the distal K-wires tend to shift radioproximally due to a single cortical wall being engaged (Fig. 4A). In type A2 and A3 DRFs, the distal fragments tend to redisplaced due to oblique fracture lines or comminuted patterns. The two proximal K-wires not only prevent redisplacement of the fragment and wire shift, but also reinforce the fixation (Fig. 4B, C). Similar to an external fixator, the frame the loss of radius height.
Our technique is a minimally invasive procedure. The wire insertion is relatively safe. The procedures are easy to perform, and the fixation is relatively rigid. It can prevent bone shortening and allow early range of motion exercises of the wrist. The disadvantage is the risks of iatrogenic injuries to the tendons, nerves, and vessels, even though the incidence is very lower than the conventional pinning technique according to our experience.
Indications for our technique are AO/OTA classification types A2, A3, B1, and B2 DRFs. Contraindications are more complex fractures, combined tendon, nerve, artery, or ligament injuries, which need to be extensively exposed, and old fractures that require open reduction and grafting. However, the technique combined with other techniques may be a choice for complex DRFs.
The limitation of the study is the fixation kinematics that needs further studies. Surgeons’ preferences, experience, and ability may influence wire configuration and position. The operations and assessments were done at different times, and surgeons’ experience improved with time, which may affect ascertaining the effects of the techniques.