Distal radius fracture is a cancellous bone fracture from 2 to 75px from the articular surface of the distal radius, and it is usually found in elderly patients. In the past, certain views held that distal radius fracture is not seriously affected by function through conservative treatment even if the deformity is obvious, but with the deepening of the understanding of distal radius fracture and the improvement of the requirements for quality of life, clinicians are increasingly required to reposition and reconstruct the distal radius fracture. In our department, from March 2008 to March 2011, 18 cases of distal radius fractures were treated with π-type plates, and the results were satisfactory at 12 months of postoperative follow-up, which are reported below.
1. Data and methods
1.1 General information
There were 18 patients in this group, 5 males and 13 females; 11 cases on the left side and 7 cases on the right side; the oldest was 73 years old, the youngest was 44 years old, and the average was 58.4 years old; there were 3 cases of car accident injury and 15 cases of fall injury; according to Fernandez typing, there were 2 cases of type II fracture (dorsal Barton fracture), 13 cases of type III fracture and 3 cases of type IV fracture; the shortest time from injury to surgery was 3 hours (1 case of emergency surgery) The longest time between injury and surgery was 24 days, with an average of 6.3 days; 11 cases had intraoperative bone grafting.
1.2 Surgical method
Brachial plexus nerve block anesthesia, tourniquet compression, and dorsal incision of the distal radius were taken. The fracture was reset by first restoring the articular surface of the distal radius, then restoring the length of the radius and the palmar inclination angle and ulnar deviation angle, with temporary fixation by Kirschner pins, and after satisfactory reset by X-ray examination, the bone was placed on the dorsal side of the radius with π-type splints and fixed by screws in sequence. If there is a bone defect, iliac bone or allograft bone can be implanted before or after fixation of the bone plate. A fascial flap was placed over the surface of the splint when the incision was closed, and a rubber drainage strip was left in the wound (see below for preoperative and postoperative radiographs).
Figure 1 Pre-operative Figure 2 Post-operative
1.3 Postoperative management
After surgery, the wrist was immobilized in a short-arm plaster splint or brace, during which passive wrist activities were performed, and functional exercises of the interphalangeal and metacarpophalangeal joints were performed as early as possible. The drainage strip was removed at 24-48 hours, and after 4 weeks, the external immobilization was removed and active and passive wrist functional exercises were performed.
2. Results
All 18 patients in this group were followed up after surgery for 12 months. The fractures healed within 3-5 months, and there was no shortening in the radial axis and no loosening or re-displacement of the π-type joint plate. The postoperative palmar inclination angle ranged from 8° to 17°, with a mean of 13.2°, and the ulnar inclination angle ranged from 16 to 26°, with a mean of 22.7°. The functional assessment of the wrist was performed according to the Gartland and Werley wrist scores. 11 cases were excellent, 6 cases were good, and 1 case was acceptable, with an excellent rate of 94.4%.
3. Discussion
Distal radius fractures are the most common type of fracture, and their incidence accounts for approximately 17% of patients with emergency fractures. Intra-articular fractures of the distal radius account for approximately 5% of fractures of the entire forearm and 25% of distal radius fractures. Because of the commonness of distal radius fractures and the diversity of fracture patterns, there are numerous ways to classify them, often resulting in confusion in diagnosis, treatment, and prognostic evaluation.
We agree with Fernandez that distal radius fractures should be classified into five types according to the mechanism of injury: type I fractures are extra-articular epiphyseal bending fractures, such as Colles fractures or Smith fractures; type II fractures are intra-articular fractures, caused by shear stress, and these fractures include Barton fractures and radial stem fractures; type III fractures are intra-articular caused by compressive loss fractures and epiphyseal bone insertion, including complex articular fractures and radial Pilon fractures; type IV is an avulsion fracture of the ligamentous attachment that occurs during radial carpal fracture-dislocation; type V fractures arise from high-velocity injuries, and the fractures often result in extensive comminution of the articular surface and involvement of the diaphysis, even spreading to the distal ulna and wrist bone.
Most type I distal radius fractures can mostly be treated successfully with nonoperative methods; type II distal radius shear fractures usually require incision and internal fixation, especially Barton fractures; type III compression injuries require surgical treatment if there is severe intra-articular injury or radial shortening; type IV avulsion fractures are often associated with radial carpal dislocation and can sometimes only be fixed with kerf pins and sutures; type V fractures require combined application of percutaneous sutures because of fracture fragmentation Type V often requires combined application of percutaneous needle penetration and external fixation because of severe fracture and is difficult to cure. In our group of 18 patients, there were 2 type II fractures (dorsal Barton fracture), 13 type III fractures (severe dorsal bone collapse and fragmentation), and 3 type IV fractures (dorsal dislocation of the radial carpal joint and fracture of the dorsal edge of the distal radius).
For the internal fixation of distal radius comminuted fracture with incisional repositioning plate, operators mostly advocate placing the plate on the palmar side of the radius because the anatomical morphology of the palmar side of the radius is flatter than that of the dorsal side, which is easy to place the internal fixation; secondly, the palmar approach does not affect the bony and tendon sheath structure, does not enter the joint cavity, the bone graft does not penetrate into the dorsal soft tissue, is easy to operate, has few postoperative complications, allows early functional exercise and fast functional recovery, etc. advantages. Of course, the palmar approach requires cutting off the anterior rotator muscle, and there is also a risk of median nerve strain.
When the distal radius fracture is predominantly dorsal, the dorsal approach has to be used. Compared with the palmar approach, the dorsal radial approach involves more tendon sheaths, and the plate is placed just below the tendon, and the thumb extensor tendon often has to straddle the plate. The dorsal radius has more bony protrusions, which is not conducive to the placement of the plate.
Lister’s node is often removed during surgery, which destroys the structure of the fibrous canal and is not conducive to tendon gliding, resulting in impaired postoperative functional recovery. In recent years, the AO has recommended a thinner π-type dorsal plate, which is designed according to the dorsal anatomy of the distal radius and can better adhere to the fracture block of the distal radius (including the radial styloid process); the fascial flap is used to cover the plate when closing the incision intraoperatively, thus avoiding frictional stimulation of the tendon, which completely eliminates the unfavorable factors of dorsal internal fixation. Its characteristics are summarized as follows.
(1) The π-type titanium plate conforms to the dorsal anatomical pattern of the distal radius, and generally adheres well to the bone surface without shaping, especially at the Lister’s node, which does not require trimming.
②The splinters are delicate in shape and flexible in texture, and can be easily shaped when needed.
③The transverse arm has 4 nail holes, which can be fixed either by screws or by kerf pins. The distal end can be placed flush with the dorsal lip of the articular surface of the radius, which can better fix the fracture block on the dorsal edge of the articular surface of the distal radius without affecting the joint movement.
Each of the two longitudinal arms has 5 nail holes, and each longitudinal arm can fix the fracture block separately, especially the radial tuberosity can be fixed firmly. The nail holes of the entire plate are dense, and the angle of inclination of the screws in each direction is large, which makes it easy to adjust the position of the screws, and the whole device forms a frame-like structure after the fixation is completed, which is firmly fixed and the stress is distributed, so that screw loosening is not easy to occur.
⑤ The diameter of the screws is thin (2.5 mm), which is convenient for fixing small bone blocks near the joint surface.
⑥Less obscuring to the fracture, and still convenient for bone grafting after fixation.
(7) The small contact area with bone protects the blood flow of bone and facilitates early fracture healing.