Is antegrade K-wire pinning better than retrograde pinning for distal radius fracture? A comparative study

INTRODUCTION

Fractures of distal end radius are one of the most common injuries seen in emergency room accounting for one-sixth of all fractures.^1-3 As wrist plays an important role for the day-to-day function of human activities, injuries to it would be devastating for the individual. With better understanding of anatomy, bio-mechanics and injury mechanism trend has been shifted to restore anatomy and obtain early function. The treatment option of distal end radius fracture includes closed reduction and cast immobilisation, percutaneous K-wire fixation (retrograde or antegrade), volar or dorsal plates. Percutaneous pinning is a minimally invasive technique to maintain the reduction and prevent re-displacement of the fracture fragments.^4,5 Many complications have been reported after retrograde pinning for distal radial fractures, including skin and soft tissue irritation, radial sensory nerve injury and extensor tendons injury, pain, algodystrophy, pin tract infection especially when left outside the skin and loss of reduction.^6-8

Antegrade intramedullary fixation introduced by Sato et al, is a minimally invasive technique where distal radius fracture is reduced by manual traction and K-wire is passed intramedullary in the antegrade direction.⁹ This procedure is beneficial in maintaining the distal radial angulation with less soft tissue complications. A retrospective study was conducted to evaluate the functional and radiological outcome of management of unstable distal radial fractures by closed manipulation antegrade intra-medullary K-wire fixation vs retrograde K-wire.

METHODS

A retrospective study with record of patients treated for distal end radius fractures who had undergone retrograde cross K-wires and antegrade intramedullary K-wires at Topiwala National Medical College and BYL Nair Hospital-Mumbai in one year from December 2019 to December 2020. Thus, a sample size of 30 patients who had undergone the above procedures were collected.

Inclusion criteria of the study were: extra articular fractures, and Frykmann type 1 and type 2 fractures.

Exclusion criteria were: intra articular fractures, open fractures, fractures with neurovascular compromise, and communited fractures.

The functional and radiological outcome were assessed at the end of one year.

An unpaired T-test was used to compare the differences in the mean of the two different groups of patients and to determine if the difference is significant or not.

As the study was retrospective, ethics committee approval was not required.

The surgical procedure

Routine clinical examination, pre op radiological and blood investigations were done. Procedure was performed under regional block, general anaesthesia with arm tourniquet and the fracture was reduced under C-arm guidance and fixed using K-wires accordingly.

Retrograde K-wire

After sterile surgical painting and draping, a 1 cm incision was made over the tip pf the radial styloid. The radial styloid was exposed by blunt dissection and great care is taken not to injure the superficial branch of radial nerve or the tendons of the first and third extensor compartment. The drill guide was introduced between the tips of the soft tissue spreader.

After checking the reduction under image intensifier, the K-wire was introduced carefully with a power drill. The K-wire should just penetrate the opposite cortex of the radial shaft.

A second incision was made between the fourth and fifth extensor compartments. Blunt dissection to the bone is carried out. Under image intensifier, the K-wire was introduced from the dorsoulnar rim of the radius into to the anterior cortex of radial shaft.

The reduction and position of the wires were checked under image intensifier. The K-wires were bent and cut off outside the skin and these wires were cleaned and covered with antiseptic soaked sponge pieces. After surgery below elbow slab was applied.

Antegrade intramedullary K-wire

After sterile surgical painting and draping an incision of around 3 cm was made on the dorsoradial aspect of the mid radius 10-12 cm proximal to radial styloid. The extensor carpi radialis brevis and extensor digitorum communis muscles were separated and cortex of radius dorsal to pronator muscle insertion is exposed. A slanting hole was made in the dorsal radius, at first drill 3.5 mm drill bit is directed perpendicularly to the bone and then obliquely at an angle 45-60 degree with care to avoid penetration to far cortex. Pre bent blunt (tip cut) 2 K-wires (1.5 mm) were introduced through these holes. The pre bent blunt K-wire were inserted with T handled chuck. At first the K-wire was directed radially and once it reached the fracture site the distal fragment was manipulated with traction and counter traction. Once the reduction was acceptable under image intensifier the K-wire was passed through the fracture site until the K-wire rests against the radial styloid subchondral bone. Another K-wire was passed and directed towards the ulnar side of the distal fragment. The proximal end of the K-wire was bent cut off and buried in the subcutaneous tissue. After surgery below elbow slab was applied.

Post-operative protocol

In the post op period strict limb elevation was given for 3 days and limb was immobilised with below elbow slab. Active finger movements were encouraged as soon as the effect of anaesthesia wore out. Elbow and shoulder mobilisation was encouraged for the patient. Pin site were inspected and dressing was done at post-operative day 3. Patient was then discharged with below elbow slab if pin sites and mobilisation were satisfactory.

Study parameters

The parameters of the study are mentioned in Tables 1 and 2.

Grades: 0 excellent, 1-3 good, 4-6 fair, 7-12 poor.

Results: excellent 90-100, good 80-89, fair 65-79, poor <65

RESULTS

15 patients had undergone antegrade K-wire fixation and other 15 patients with retrograde K-wire fixation (Figure 1).

Majority of the patients were in 41-50-year group. Mean age at surgery was 46.5 years overall (Figure 2).

The patients were predominantly males (56.6%) with dominant limb being most common involvement (60%).

Most patients had Frykmann type 2 fracture (66.6%) with fall being the mode of trauma in most patients (53.4%) (Figure 3).

Association between radiological scores and type of surgery

The antegrade K-wire had excellent radiological score in 66.7%, whereas retrograde K-wire had 53.3% excellent score. But was no statistically significant association seen between radiological score and the groups (p=0.748), showing that the radiological outcome was not dependent on the type of surgery (Figure 5).

Association between functional scores and type of surgery

There was no statistically significant association seen between functional score and the groups (p=0.875) at the end of 6 months, showing that the functional outcome was not dependent on the type of surgery (Figure 6).

DISCUSSION

Distal end radius fractures are one of the commonest fractures encountered by an orthopaedist. The fracture pattern can vary from minimally displaced stable fractures to comminuted intraarticular fractures. Management of intra articular fractures requires articular reduction and stabilization. The extra articular stable distal end radius fractures are most commonly managed by closed reduction and plaster cast or by closed reduction and pinning.

The disadvantage of closed reduction and plaster is the loss of reduction and malunion. Closed reduction and pinning prevent loss of reduction and malunion. There are numerous techniques described for closed reduction and pinning of distal end radius fractures like cross K-wire, antegrade K-wire, and Kapandji technique.

In this study we compared the functional and radiological outcome of distal end radius fractures treated by two different methods of pinning, retrograde cross K-wire and antegrade K-wire.

Our study comprised of 30 patients with 17 being male and 13 females with male percentage being 56.4%. The higher incidence of male could be attributed to highly active work group, increased outdoor activity.

Majority of the patients in the study were in the age group 41-50 with mean age being 46.5 years, which is comparable to other studies published earlier where mean age group was 48 years.¹³

Dominant side was more involved compared to non-dominant side, with dominant being 60%.

Majority of the patients had fall as mode of trauma (53.4%). This could be due to an older mean age group of study where a low energy trauma (fall) is more frequent in causing Frykmann type 1 and type 2 fracture on the outset of osteoporotic bone.

Sezai et al conducted a study of 34 patients with distal end radius fracture treated with cross K-wire and concluded that this is a reliable method in treating simple distal end radius fracture.¹⁴

Mostafa et al conducted a study of 28 patients with distal end radius fractures treated with antegrade K-wire and concluded that it is an effective technique for stabilization and prevention of secondary displacement of distal radius fracture.¹⁵ In this study it was also concluded that soft tissue complications like pin tract infection, pin loosening, tendon injury were comparatively lower than of other studies using retrograde pinning.

In our study there was one case of pin loosening in antegrade K-wire and 4 cases of pin tract infection in retrograde K-wire. The pin loosing did not result in loss of reduction. The pin tract infection settled with antibiotics and fracture progressed to healing.

The complication rate was 6% in antegrade K-wire which is comparable to 4% in Mostafa et al compared to retrograde K-wire of 26%.¹⁵

The mean dorsal tilt in our study treated with antegrade K-wire group was 3.33 and in retrograde K-wire group was 5.67. The lesser dorsal tilt in antegrade K-wire group with respect to retrograde K-wire group is comparable with that of other studies and indicated that this technique could prevent dorsal tilt. But the dorsal tilt difference in both groups was found to be statistically not significant.

The ulnar variance and radial shortening in both groups when compared was found to be statistically not significant.

There was no statistically significant association seen between radiological score and the groups, showing that radiological outcome was not dependent on the type of surgery.

There was no statistically significant association seen between functional score and the groups.

The limitation of our study is small sample size.

CONCLUSION

Both antegrade K-wire and retrograde K-wire procedures are an effective treatment for extra articular distal end radius fractures without any statistically significant difference in radiological and functional outcome. Both the procedures have shorter duration of procedure with preservation of fracture hematoma. These procedures are only suitable for patients with extra articular fractures. Since most of the surgeons are familiar with retrograde K-wire technique, in this study we would like to conclude that antegrade K-wire technique is an useful and safe alternative to retrograde technique for distal radius fractures and is associated with less soft tissue complications compared to retrograde K-wire technique.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the institutional ethics committee

REFERENCES

1. 1. Owen RA, Melton LTIII, Johnson KA, Ilstrup DM, Riggs BL. Incidence of Colles’ fracture in a North America community. Am J Public Health. 1982;72:605-7.
2. 2. Jupiter JB. Current concepts review. Fractures of the distal end of the radius. J Bone Joint Surg [Am]. 1991;73:461-9.
3. 3. Simic PM, Weiland AJ. Fractures of the distal aspect of the radius: changes in treatment over the past two decades. Instr Course Lect. 2003;52:185-95.
4. 4. Clancey GJ. Percutaneous Kirschner-wire fixation of Colles’ fractures. J Bone Joint Surg [Am]. 1984;66:1088-114.
5. 5. Kurup HV, Mandalla V, Shaju A, Beaumont A. Bicortical K-wires for distal radius fractures: how many? Acta Orthop Belg. 2007;73:26-30.
6. 6. Hargreaves DG, Drew SJ, Eckersley R. Kirschner wire pin tract infection rates: a randomized controlled trial between percutaneous and buried wires. J Hand Surg. 2004;29:374-6.
7. 7. Singh S, Trikha P, Twyman R. Superficial radial nerve damage due to Kirschner wiring of the radius. Injury. 2005;36:330-2.
8. 8. Van Aaken J, Beaulieu JY, Della Santa D, Kibbel O, Fusetti C. High rate of complications associated with extrafocal Kirschner wire pinning for distal radial fractures. Chir Main. 2008;27(4):160-6.
9. 9. Sato O, Aoki M, Kawaguchi S, Ishii S, Kondo M. Antegrade intramedullary K-wire fixation for distal radial fractures. J Hand Surg [Am]. 2002;27(4):707-13.
10. 10. Stewart HD, Innes AR, Burke FD. Factors affecting the outcome of Colles’ fracture: an anatomical and functional study. Injury. 1985;16:289-95.
11. 11. Green DP, O’Brien ET. Open reduction of carpal dislocation. Indications and operative techniques. J Hand Surg. 1978;3:250-65.
12. 12. Cooney WP, Dobyns JH, Linscheid RL. Complications of Colles’ fractures. J Bone Joint Surg [Am]. 1980;62:613-9.
13. 13. Das AK, Sundaram N, Prasad TG. Percutaneous pinning for non-comminuted extra-articular fractures of distal radius. Indian J Orthop. 2011;45(5):422-6.
14. 14. Özkan S, Westenberg RF, Helliwell LA, Mudgal CS. Distal Radius Fractures: Evaluation of Closed Reduction and Percutaneous Kirschner Wire Pinning. J Hand Microsurg. 2018;10(3):134-8.
15. 15. Mostafa MF. Treatment of distal radial fractures with antegrade intra-medullary Kirschner wires. Strategies Trauma Limb Reconstr. 2013;8(2):89-95.