Prospective study of ulnar nerve injury while treating supracondylar fracture humerus of children by crossed per cutaneous pinning

 

Ganesh P Subbaiah¹, Shiva Naik^2*

 

Abstract              Background: supracondylar fracture are frequent fractures in children1. Extension type being more common representing around 97% of cases. Closed reduction and per cutaneous pinning is the gold standard treatment for Gartland’s type 2B, 3 and type 4 fractures. Lateral entry pins provide stable fixation without medial pins avoiding iatrogenic ulnar nerve injury. However proper techniques helps to reduce the ulnar nerve injury in using crossed pins which provides better stability. Objective: To study the clinical outcome of displaced supracondylar humerus fracture fixation by crossed pins Materials and Methods: A prospective study was carried out between January 2015 to March 2019 in Wayanad institute of medical sciences where 106 children with displaced supracondylar fracture humerus who were treated surgically by per cutaneous crossed pinning. They were followed up for a minimum period of 9 months and evaluated for clinical outcome using Results: Out of 106 cases 98 cases had excellent results and 7 patients had good results with ulnar nerve palsy in 6 children. One child had poor outcome due to post op infection which necessitated early implant removal. All six cases with ulnar nerve palsy recovered over 8 weeks follow up. Medial K wire was removed post operative in two case with ulnar nerve palsy. Conclusion: In our study of displaced supracondylar fracture humerus in paediatric age group, which were effectively treated surgically with per cutaneous medial and lateral pinning gave excellent results and better stability instead of lateral pinning alone.

Key Words: supracondylar; closed reduction; humerus; children; elbow; K Wires fixation; ulnar nerve palsy; cubitus varus; percutaneous pinning; posterior displacement.

 

INTRODUCTION

In children, supracondylar fractures are the most common fractures affecting elbow. The distal humerus is predisposed to injury because its configuration in two columns connected by thin bone which represents a zone of weakness. During fall on the outstretched hand, the olecranon engages on the olecranon fossa and if elbow extension progresses, the olecranon finally acts as a fulcrum on the fossa. So, the bone begins to break at first anteriorly and progresses posteriorly. The fracture severity depends on the force of injury. If the energy is high, the posterior cortex gets fractured and finally complete posterior displacement of the distal fragment occurs. The posterior periosteum acting as a hinge. This is the mechanism of extension-type fractures, which represent 97% to 99% of the total.⁴ In posteromedial displacement, radial nerve is at risk of primary injury or during a reduction manoeuvre. Posterolateral displacement has risk of brachial artery and median/AIN nerves. Flexion-type fractures frequently involves neurovascular structures than extension-type fractures particularly ulnar nerve. Proper systematic management of these fractures are of paramount importance to avoid unwanted complications. Controversy remains with regard to fixation methods when closed pinning is considered. Traditionally, Gartland’s type 1 and type 2A fractures are treated conservatively and type 2B; type 3 and 4 are treated surgically more commonly by closed method and by open technique when closed reduction fails. Controversy remains regarding the usage of medial K wires considering the chances of ulnar nerve injury. We usually use a 1.8-mm K-wire for percutaneous pinning. Once the fracture has been fixated, we extend the elbow and check for stability. In our study, lateral K Wire is used first followed by medial pinning. After checking for stability, it is decided weather to use further lateral K Wires.

Objectives

To study the clinical outcome of paediatric displaced supracondylar fractures managed surgically by both medial and lateral percutaneous K Wires

 

MATERIALS AND METHODS

With a level IV evidence, a prospective study was carried out from January 2015 to March 2019 in Wayanad institute of medical sciences. A total of 106 patients with displaced supracondylar fractures were treated surgically by percutaneous medial and lateral K Wires who were followed up for a minimum period of 9 months periodically and evaluated for clinic-functional outcome. The patients with age less than 14 years, patients with displaced supracondylar fracture humerus (Gartland’s type 2B, 3 and type 4), patients with displaced supracondylar fracture humerus less than two weeks were included in the study. Children who required open reduction, fractures with intercondylar extension and children who had neurovascular complications were excluded from the study. After getting ethical clearance from the institute and informed written consent of the patients enrolled in our study, all were subjected for thorough examination. The baseline investigations and radiographic analysis of the affected elbow were analysed. According to Gartland’s classification, all cases belonging to type 2B, 3 and type 4 were posted for surgical management with percutaneous combined medial and lateral K Wire fixation and follow up according to our study protocol. Other associated injuries were addressed off with appropriate management. Postoperatively, the patients were given a above elbow slab for 4 weeks followed by active range of motion exercise without slab for next 2 weeks. K Wires were removed after 8 weeks. Radiographs were taken after 2,4 and after 6 weeks for the clinical assessment. Assessment included standardized clinical evaluation Most of patients were in the age group between 4 to 12 years. The youngest was 1 year and oldest was 14 years. There were 76 males and 30 female children. 70 of the fractures were sustained following self fall while playing and 20 cases following fall from bicycle and 16 cases following fall from height. Right side humerus was fractured in 66 children and left in 40 children. On an average the timing of surgery was 1 day post injury. The main aims of surgical fixation are restoration of the Baumann angle, having intact medial and lateral columns as per the oblique radiographs and the anterior humeral line passing through the anterior third of the capitellum on the radiograph. Patient was put in supine position. Under short general anaesthesia parts painted and draped. The fracture is reduced by traction in extension at elbow followed by correction of deformity in the coronal plane correcting the medial/lateral displacement along with correction of valgus and varus deformity. This is followed by flexion of elbow pushing the olecranon anteriorly to correct the extension of distal fragment. The adequacy of reduction in the coronal plane can be assessed with Jones views of the distal humerus with the hyperflexed elbow in slight internal and external rotation. Lateral pinning was done first followed by medial pinning. Stability tested after fixation of 2 pins. Additional lateral pins were used to improve the fracture stability. Limb immobilised in above elbow slab. Total of 14 cases had associated injuries namely 8 children with ipsilateral epiphyseal injury distal end of radius, 6 with ipsilateral both bones fracture forearm. Cases were admitted in hospital for an average of 3 days. All the cases were operated with crossed percutaneous medial and lateral pinning. 1.5 to 2 mm K Wires were used depending on the age of child. 56 cases were treated with 2 K wires (one medial and 1 lateral) 40 cases were treated with 3 K Wires (1 medial and 2 lateral) and 10 cases were treated with 4 kires (1 medial and 3 lateral). Not more than one medial K Wire was used in any of the cases.

The mean operative time was 26 min (range, 15 to 50 min). The bony union was achieved in all cases after surgery at an average of 8 weeks (range, 4 to 10 weeks). These children returned to their daily routine activities from the time of injury on an average Neurological examination can be challenging. In the acute setting, the pain and anxiety of the child and his/her parents can make the examination difficult. Neurological examination can be challenging. In the acute setting, the pain and anxiety of the child and his/her parents can make the examination difficult. 

of 8 weeks (range, 4 to 14 weeks). Postoperative complications were noted in follow up. Complications included ulnar nerve palsy in 6 children One child had poor outcome due to post op infection which necessitated early implant removal. All six cases with ulnar nerve palsy recovered over 8 weeks follow up. Medial K wire was removed post operative in two case with ulnar nerve palsy.

 

 

 

 

DISCUSSION

In supracondylar fracture of children, Most commonly used is Gartland’s ^2. classification¹⁶.

• Type I. Non-displaced fractures (< 2 mm). The AHL still crosses through the centre of the capitellum. These fractures are stable because of the integrity of the periosteum.
• Type II. Moderately displaced (> 2 mm). The AHL passes anterior to the centre of the capitellum; the posterior periosteum is intact but acts as a hinge.
• Type III. Completely displaced. This type of fracture is more unstable, with extensive soft-tissue and periosteal damage and increased incidence of neurovascular injuries.

Gartland’s classification was modified by Wilkins in 1984^3. subdividing type II fractures into IIA or IIB according to the absence (IIA) or presence (IIB) of malrotation. In 2006, Leitch et al. ^4. introduced a new type IV fracture, in which the periosteum is completely torn, which leads to a high instability of the fracture both in flexion and extension. Multidirectional instability of type IV fractures can be caused by the injury itself or by repeated failed attempts of reduction. Type IV fractures can only be diagnosed intra-operatively. It is important that the entire limb is evaluated in children sustaining supracondylar fractures. Ipsilateral forearm fractures can occur and increase the risk of compartment syndrome. Assessment of the soft tissue swelling and presence of any skin puckering is critical information to be sought. This results from the proximal fragment piercing the overlying brachialis muscle and resting on the dermis of the overlying skin. The vascular status needs to be interrogated and the radial pulse, temperature and colour of the hand needs to be recorded and compared to the contralateral side, as does the capillary refill. Vascular examination findings must be clear as this will influence the rapidity of management. A white, cold, pulseless hand will ultimately have a different approach to a pink warm hand with a bounding pulse. The preoperative neurological status is imperative due to the high prevalence of neurological injury and the possibility of an iatrogenic nerve injury. Signs such as extensive ecchymosis, skin puckering and soft-tissue swelling indicate severe trauma. attention should be taken when skin puckering is present. This sign appears when the proximal fragment transects the brachialis muscle, ‘puckering’ the deep dermis. For this reason, when skin puckering is present, severe displacement and soft-tissue damage, including brachial artery and median nerve entrapment, should be expected,¹⁰ although no differences are found in long-term outcomes with correct management. Posteromedial displacement of the fracture is associated with median and anterior interosseous nerve dysfunction; posterolateral displacement is associated with brachial artery injury. Usually type 1 and type 2A fractures are treated by closed reduction and casting. Above elbow cast with flexion of 80 to 90 degree at elbow is needed to maintain reduction. Type III and type IV fractures should be managed surgically^5,6. Initial Immobilisation with above elbow splint with limited flexion of 40 to 50 degree and assessment of vascular and neurological status of limb is most important. Definitive management should be done as early as possible. Fracture can be reduced by open or closed technique. Angular and rotational malalignment should be assessed along with medial /lateral displacement. The fracture is reduced by traction in extension at elbow followed by correction of deformity in the coronal plane correcting the medial/lateral displacement along with correction of valgus and varus deformity. This is followed by flexion of elbow pushing the olecranon anteriorly to correct the extension of distal fragment. In posteromedial displacement, the posterolateral periosteum is torn and the posteromedial periosteum is usually intact. Hence, forearm pronation will put the medial periosteum in tension, helping closure of the fracture and avoiding varus collapse. On the other hand, in posterolateral displacement, forearm supination at the time of reduction will bring the lateral intact periosteum in tension, helping reduction. K-wire from medial to lateral can be passed through the distal fragment and used as a joystick which assists in fracture reduction while pinning. Open reduction is indicated when there is failure of closed technique or if the brachial artery has been compromised and requires exploration. By operative reduction and pinning, preoperative arterial insufficiency may be improved, Kinked brachial artery may become patent after manipulative reduction of the fracture. Ischemia of limb following vascular injury will lead to Volkmann”s ischaemic contracture. There are studies supporting the principle that crossing pins provides more stability rather than lateral pins alone.^7. There are Several techniques to avoid ulnar nerve injury with medial pinning.^8,9, The elbow in semi-extension allows posterior displacement of the ulnar nerve. Anterior displacement of the ulnar nerve occurs when the elbow is flexed beyond 90 degree and the risk of injury of ulnar nerve increases. The thumb is used to press over the epitrochlea to decrease the oedema and facilitate palpation of bony references. Later, the thumb is displaced posteriorly to protect the nerve and a T-handle is used to insert the pin anteriorly to the thumb.⁸ Complications includes cubitus varus deformity due to mal reduction, vascular injury, nerve injury (can appear either before surgery or after reduction and fixation of the fracture) affecting radial/median/ulnar nerves. The majority of these injuries are neurapraxias and heal spontaneously. Cubitus varus deformity following paediatric supracondylar fracture of the humerus consists of varus, hyperextension, and internal rotation deformities of the distal fragment of humerus. Compartment syndrome due to oedema and soft tissue contusion especially in multiple attempts of closed reduction can happen.

 

CONCLUSION

Though there is increased chance of ulnar nerve injury in crossed pinning in supracondylar fracture fixation of humerus in children, the incidence can be decreased by following proper techniques to protect the ulnar nerve.

 

REFERENCES

• Beaty JHKJ . Supracondylar fractures of the distal humerus. In: Beaty JH, Kasser JR, ed. Rockwood and Wilkins’ fractures in children. 6th ed. Philadelphia: Lippincott Williams and Wilkins; 2006:543-589.
• Gartland JJ . Management of supracondylar fractures of the humerus in children. Surg Gynecol Obstet 1959;109(2):145-154.
• Wilkins KE . Fractures and dislocations of the elbow region. In: Flynn JM, Skaggs DL, Waters PM, eds. Fractures in children. Philadelphia: Wolters Kluwer, 1984:363-575. G
• Leitch KK , Kay RM , Femino JDet al.. . Treatment of multidirectionally unstable supracondylar humeral fractures in children. A modified Gartland type-IV fracture. J Bone Joint Surg [Am] 2006;88-A(5):980-985.
• Omid R , Choi PD , Skaggs DL . Supracondylar humeral fractures in children. J Bone Joint Surg [Am] 2008;90-A(5):1121-1132.
• de las Heras J , Durán D , de la Cerda Jet al.. . Supracondylar fractures of the humerus in children.
• Zionts LE , McKellop HA , Hathaway R . Torsional strength of pin configurations used to fix supracondylar fractures of the humerus in children. J Bone Joint Surg [Am] 1994;76-A(2):253-256
• de las Heras J , Durán D , de la Cerda Jet al.. . Supracondylar fractures of the humerus in children. Clin Orthop Relat Res 2005;(432):57-64.
• Onwuanyi ON , Nwobi DG . Evaluation of the stability of pin configuration in K-wire fixation of displaced supracondylar fractures in children. Int Surg 1998;83(3):271-274.

 

 

 

 

 

 

 

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