Open Reduction And Internal Fixation Of The Distal Radius Fractures

Distal radius fracture is very common in clinical works, which accounts for about 20% of all fractures. And dorsal intra-articular fracture is the most common type. The distal radius fracture is mainly occurred in the 6 to 10-year-old and 60 to 75-year-old phases as previous research statistics, but in recent years, the incidence of this type of fracture in young people increases gradually. Pouteau first described the fracture in 1783, and then scholars at home and abroad started to research the fracture. However, the long-term effect of this type of fracture is still uncertain because it has different injury forms and treatment methods.The distal radius, the main connected structure of the forearm and wrist, locates superficially and has two physiological angles, which are the ulnar inclination varying from 13°to 30°with the mean 23°and the volar tilt with the angle of 10°to 12°on average. The activity scope of the radiocarpal joint is the biggest, amounting to 140°, and ulnar and radial drift is up to 60°. The distal radial ulnar joint can be rotated by 150°. As for the biomechanics, studies have shown that the radiocarpal joint bears 80% of the axial load.Most of the distal radius fractures are due to falling with the hand over-stretched or the traffic accidents. Although Extra-articular fracture is the main injured type, comminuted fractures of distal radius are increasing in recent years due to the high-energy trauma. The distal radius is mainly composed by cancellous bone. During fracture the cancellous bone will collapse and then makes radius shortened and the ulnar inclination and volar tilt smaller, so it will produce a serious influence to the radiocarpal joint and distal radial ulnar joint in coordination and rotation. When choosing method for treatment of the distal radius fracture the classification of fracture and the extent of damage should be considered. For simple, we can choose closed reduction and fixation method to treat stable extra-articular fracture and some intra-articular fracture. If the functional reduction can not be achieved or the location of the reset fracture can not be maintained, surgery is considered.For the comminuted intra-articular fracture and invalid manipulative reduction cases, open reduction and internal fixation is a very effective means of treatment. It can maximize the restoration of the integrity of joints and provide anatomical basis of functional recovery. It is believed that surgery should be performed when the reduction can not be maintained after manipulative reduction and gypsum fixation. Specific indications include: (1) notable comminuted fractures; (2) a wide range dorsal smash up to 50% or more than diameter metaphysic; (3) displaced intra-articular comminuted fracture; (4) the articular surface shift >2 mm; (5) shortening>10mm; (6) major fracture block's angle>20°; (7) osteoporosis; (8) age> 60 years old. The progress of open reduction and internal fixation currently is mainly reflected in two aspects which include internal fixation devices and improving of the choice of the operative approach.At present the internal fixation materials include small "T" plate, screws, pinning, AO"π"-shaped plate, tube-shaped plate, as well as the locking compression plate (locking compression plate, LCP). Choosing suitable fixation material to treat different fractures will make the fractures'fixation and the restoration of joint function satisfying. It is reported that the LCP was used extensively and the results were always very good. There are three operative approaches which are metacarpal approach, dorsal approach and union approach. We will illustrate the first two approaches in detail as follow. (1) Metacarpal approach: In this approach, the incision will be made at the radialis of the flexor carpi radialis muscle, and the pronator quadratus musle is revealed between the flexor carpi radialis muscle and radial artery. At last the operators will cut the periosteum and the insertion of the pronator quadratus musle at the lateral edge of the radial bone and then expose the fractures. (2)Dorsal approach: During dorsal approach, the incision is usually made between different extensor spacing according to different purposes. Making incision in the interval between the first and second extensor spacing is used to treat the fracture of the radial styloid, while incision in the dorsal of the Lister nodules crossing the 3rd dorsal interval should be made in revealing dorsal radial metaphysis and articular surface fracture. In recent years, it is observed that dorsal plate which is used to treat the distal radial fracture can make extensor tendon abrasion or rupture. Furthermore, dorsal incision often hurts superficial radial nerve and the branch of the radial artery. The branchs of dorsal ulnar nerve are also vulnerable when extending the incision to the dorsoulnar of the wrist. However, the metacarpal approach has small damage to cortical bone and the reset mark is very clear. Contrarily, palm side of the distal radius is very flat. So the setting of plate is easily achieved and the internal fixation is stable. In front of the plate there are pronator quadratus muscle and other soft tissues, so it can reduce the adhesion of soft tissue ,tendon inflammation ,wound infection and the exposure of the plate. Therefore, it tends to choose operative incision in the palm side. If there is bone defect autoallergic ilium graft can be chosen, which can induce bone growth and promote bone healing by providing support for intra-articular fracture. Penning thought that bone graft should be considered under the following circumstances: (1) shortening> 10 mm; (2) ulnaris bone shortening> 5 mm; (3) in patients with osteoporosis.The merit of operation is that it can make the fracture anatomical reduction, and make normal volar tilt and ulnar inclination recovered. In this way patient may do functional training early, and restore the wrist function as far as possible.However, the operation still has some inevitable complications. For example, injury of the nerve and tendon, tendon adhesion and ankylosis are the very common complications. And the incidence of traumatic wrist arthritis and carpal instability is also high.From August 2005 to October 2007, 22 cases of distal radius fractures were treated with open reduction and internal fixation and all achieved good results. The classification of the fractures is according to the AO classification method. Of 22 cases, 8 cases were classified as type A (A2, 2 cases; A3, 6 cases), while 6 cases were defined as type B (B2,4 cases; B3,2 cases) and 8 cases as type C (C1,4 cases; C2,1 case; C3,3 cases).Insicion was firstly made at the radial of the flexor carpi radialis muscle on palmar (classical Henry incision), and the pronator quadratus muscle between the flexor carpi radialis muscle and radial artery was then revealed. The periosteum and the insertion of the pronator quadratus muscle at the lateral edge of the radial bone were cut, and then the fractures exposed. Attention should be paid not to damage too much periosteum and pronator quadratus muscle while revealing the fracture. Fracture could be reset after removing the soft tissue in it. The flatness of the artidular surface of the distal radius and the height of the radial styloid should be observed to restore the volar tilt of the distal radius' articular.We used autoallergic bone graft to fill the fracture if the patients have bone defect and collapse, while AO "T" plate is applied to fix the fracture in the condition of the maintenance of good reduction. Attention was paid to suture of the pronator quadratus muscle to cover the plate and that will reduce the incidence of postoperative complications.On the whole patients enrolled felt satisfied after the operation, and the mean functional recovery time was 4.84 months. The mean follow-up period was 13.55 months. The curative effect of the surgery was evaluated by the functional rating scale of Gartland and Werley, 11 cases were graded as excellent (accounting for 50%), 4 cases (18%) as good, 6 cases (27%) as fair and 1 case (5%) as poor.We paid attention not to damage too much periosteum and pronator quadratus muscle and suture of the pronator quadratus muscle to cover the plate and that reduced the incidence of soft tissue adhesion, tendinitis and tendon rupture and other complications.We believe that open reduction and internal fixation in the treatment of the distal radius fracture can make the fracture anatomical reduction, recover normal volar tilt and ulnar inclination. Also it can facilitate the early functional training of patients, so early restoration of wrist function can be achieved.