CHAPTER 17 Kapandji Pinning of Distal Radius Fractures
Distal radius fractures are among the most common upper extremity injuries. They account for one sixth of all fractures treated in the emergency department1 and this incidence is expected to increase as the population ages. Thompson and colleagues report that the incidence of distal radius fractures continues to rise with age in women older than 50 and in men older than 65.2
Many different treatment methods have been advocated depending on the fracture type and stability. Various authors have attempted to identify factors that predict instability in distal radius fractures. Mackenney and coworkers found that the most consistent predictors of instability were patient age, metaphyseal comminution, and ulnar variance.3
Many methods of percutaneous pinning have been described in the literature, including trans-styloid pinning, intrafocal pinning, and pinning into the distal fragments.4–10
This technique was originally described by Kapandji in 1976 as a method of treating unstable extra-articular distal radius fractures.11 His original report described a technique whereby two threaded K-wires were inserted into the fracture site and then used to directly manipulate and lever the distal fracture fragment into the desired position. Once reduction was achieved, the wires were advanced into the proximal fragment; the pins do not fix the distal fragment but rather buttress it in place. In the original description, patients were not immobilized postoperatively. Kapandji originally advocated this technique for younger patients, whose fractures were only minimally comminuted. It was contraindicated in patients with osteoporotic bone or severe comminution and in fractures with intra-articular extension. In the original publication, little information was available regarding the clinical results of this procedure.11
In 1987, Kapandji reported his experience with the original technique and recommended adding a third dorsal ulnar pin.12 He expanded the indications to include fractures with multiple fragments.12 Since then, many authors have described modifications to the original technique,11 and the clinical indications have expanded from those originally described.13–21
Literature Review
There are several published case series reporting a large percentage of overall good to excellent results using intrafocal pinning. Epinette and associates reported 83% good and excellent results in 70 cases, including elderly patients and fractures with undisplaced intra-articular extension.13 Docquier and colleagues also reported a high percentage of good and excellent clinical and radiographic results using this technique for articular and extra-articular fractures.14 Peyroux and coworkers reported the outcome of 159 cases (81% extra-articular) with 93% good and excellent clinical results.15
Dowdy and associates retrospectively reviewed the results of 17 patients treated with intrafocal pinning.16 All K-wires were cut below the skin, and the injured area was immobilized for 6 weeks. Sixteen of 17 patients were pleased with their outcomes. The average visual analog score on the pain scale was 0.44/10, and function was 8.6/10. There was a trend for older osteopenic patients to lose their postoperative reduction, but this was not statistically significant.16 Patients aged 65 and older also had significantly less restoration of volar tilt than those younger than 65 years of age (P = .04). Dowdy recommended that Kapandji pinning alone should be avoided in patients with severe osteopenia.
In the largest series published to date, Nonnenmacher and coworkers reported the results of 350 intra-articular and extra-articular distal radius fractures in patients aged 12 to 89 treated with this technique.17 They used three intrafocal pins, which were buried below the skin and removed at 6 weeks. Plaster immobilization was not used, and patients were allowed to begin range of motion postoperatively. The subjective results were good and excellent in 90% of patients, and functional outcomes were reported as good and excellent in 99%. No patients reported poor subjective or functional outcomes. The radiologic results were also evaluated as 93% good to very good, 6% average, and 1% poor.17
The experience with intrafocal pinning in older patients has grown in recent years. Greating and coworkers reported on the results of 24 fractures with minimal intra-articular involvement in patients aged 16 to 94.18 They utilized immobilization in patients for 6 weeks after the surgery. In 13 fractures, the clinical outcomes were excellent in 7, good in 4, and fair in 2 based on the Mayo wrist score. The two fair results were in patients younger than age 65. They also report good and excellent radiologic results (using Sarmiento and colleagues’ criteria22) in 79% of patients younger than 65 and in 60% of patients older than 65. They concluded that this technique provides acceptable clinical results in elderly patients despite some loss of reduction after pinning.
Trumble and coworkers published a review of their experience with intrafocal pinning supplemented with external fixation.19 They reviewed 61 patients with either intrafocal pinning alone or in combination with external fixation. They included fractures with undisplaced intra-articular extension and all age groups. There were 96% good to excellent results in young patients (<55 years) with displaced extra-articular distal radius fractures (minimal comminution) treated with intrafocal pin fixation alone. In patients older than 55 years of age, they reported 94% good to excellent results in patients who received supplemental external fixation and they also reported that range of motion, grip strength, and pain relief were significantly better when external fixation was used in this age group, even when only one cortex demonstrated comminution. Their final recommendation was that older patients, or younger patients with involvement of more than two surfaces of the radial metaphysis (or >50% of the metaphyseal diameter), require external fixation in addition to percutaneous pin fixation for optimal results.19
In a retrospective review by Board and associates comparing closed reduction and casting to intrafocal wiring in patients older than 55 years, it was found that functional results were good to excellent in 19 of 23 patients who received intrafocal pinning versus 12 of 23 who received plaster alone, supporting the use of this technique in older patients.20
Hollevoet recently published a study assessing anterior fracture displacement in Colles’ fractures after intrafocal pinning in women older than age 59 years (without supplemental external fixation).21 It was demonstrated that the intrafocal pins were not sufficient to prevent anterior fracture displacement in almost one third of patients. Five weeks after fracture, 36 of 89 (40.4%) patients had more than 20 degrees of palmar shift or tilt or more than 10 degrees of dorsal angulation; 37 patients (41.6%) had more than 2 mm of ulnar-positive variance; and 6 (6.7%) had more than 5 mm of ulnar-positive variance. The clinical implications of this displacement were not discussed. They concluded that intrafocal wiring of Colles’ fractures in elderly, osteoporotic patients may not be sufficient to prevent anterior fracture displacement.21
