Minimally Invasive Closed Reduction and Internal Fixation With Fully Threaded Headless Cannulated Compression Screws for Repair of Distal Radius Fracture: Study Protocol for a Randomized Controlled Trial

Distal radius fracture is defined as a fracture within 3 cm of the distal articular surface. When radius fracture and ulnar styloid process fracture occur together, internal fixation is generally not pursued; however, adverse events may occur after reduction with external fixation, including unstable fracture fragments, malalignment, and loss of radial inclination and ulnar deviation, leading to wrist function impairment.

The commonly used treatment methods for distal radius fracture include internal fixation with steel plate, internal fixation with Kirschner wire, and external fixation. Open reduction and internal fixation (ORIF) has disadvantages. For example, the pronator teres is incised in palmar ORIF and in situ suturing of the muscle is not possible in most patients after implantation of the titanium plate. Even when suturing is possible, the strength of the pronator teres will decrease after surgery, and a second surgery is needed to remove the titanium plate. Dorsal ORIF is also disadvantageous because more tendons and thin soft tissue may be encountered during surgery. In addition, tendon sheath injury is inevitable, leading to myotenositis, tendon adhesion, and even tendon rupture. Thus, internal fixators should be taken out as early as possible. Satisfactory wrist function outcomes have been achieved with external fixators, in particular with dynamic external fixators. However, although external fixation has good fixing effects, it provides poor lateral stability, resulting in injury to the superficial branch of the radial nerve, screw channel infection, screw channel fracture, screw loosening, and even Sudeck's atrophy. Internal fixation with Kirschner wire generates minimal surgical trauma, but this technique does not provide sufficient strength for fixation and is therefore rarely used at present. There is an urgent need to develop a more stable fixation method for distal radius fracture. Minimally invasive surgery avoids the tissue damage and impairment of physiological function caused by open surgery because of its precise location techniques. Brachial plexus anesthesia allows surgeons to avoid large incisions and excessive bleeding. There are no palmar or dorsal incisions in minimally invasive surgery for distal radius fractures, so the structures surrounding the wrist joint are not iatrogenically damaged, which theoretically improves wrist function recovery.

During C-arm fluoroscopy-assisted minimally invasive closed reduction, either no surgical incision or an incision only 0.5 cm in length is made at the wrist joint; the fracture fragments are reduced with fully threaded headless cannulated compression screws. Repair stability is assessed with the C-arm fluoroscopic X-ray system. This method is theoretically feasible for distal radius fractures. The fracture fragments are fixed with fully threaded, cannulated, variable-pitch, headless compression screws, which can increase fragment stability. Therefore, the investigators hypothesize that C-arm fluoroscopy-assisted minimally invasive closed reduction will fix distal radius fractures and allow patients to perform wrist function exercises as early as possible.

Our previous studies have confirmed that minimally invasive closed reduction and internal fixation with fully threaded headless cannulated compression screws has precise therapeutic effects for distal radius fractures. This method can improve wrist function, and has therapeutic effects similar to those of conventional open reduction and internal fixation with titanium plates. The results of these previous studies are shown in Table 1. However, it is not clear whether minimally invasive closed reduction and internal fixation with fully threaded headless cannulated compression screws has advantages over conventional open reduction and internal fixation with titanium plates for distal radius fracture repair.

In this study, the investigators hypothesized that minimally invasive closed reduction and internal fixation with fully threaded headless cannulated compression screws provides better stability than conventional methods, and can effectively promote the early recovery of wrist function. Under conditions of no cutting of fracture fragments, no blood supply compromise in the fracture fragments, and no destruction of the local microenvironment, and with C-arm fluoroscopy assistance, the investigators will perform minimally invasive closed reduction, pressurizing the fracture fragments with fully threaded headless cannulated compression screws, and will investigate whether this method of distal radius fracture repair provides satisfactory stability and allows early wrist function recovery.