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Ulnar nerve palsy: a complication following percutaneous fixation of supracondylar fractures of the humerus in children
Copyright
c
1996
f+rry Vol. 27, No. 5, pp. 303-305. 1996 Elsevier Science Ltd. All rights reserved Printed in Great Britain 002C-1383/96 $15.00 + 0.00
ELSEVIER
PII: s0020-1383(96)00013-7
Ulnar nerve percutaneous the humerus
palsy: a complication following fixation of supracondylar fractures in children
of
M. A. Ikram Division of Orthopaedics, King Khalid University Hospital, Riyadh, Saudi Arabia
Fourchildren,who developed ulnar nerve palsy followingpercutaneous fixation of supracondylar fracture of the humerus by Kirschner wires (K-wires) are reported. In one the K-wire was removed within 48 hand the neuropraxia recovered immediafely. In the other three patients recovery took an average of 6 weeks after removal of the wires and only after exploration of the ulnar nerve. The nerve was found to be trapped behind the medial epicondyle of the humerus. Release and subsequent transposition of the nerve resulted in recovery. Certain measures are suggested to prevent this avoidable complication in the treatment of supracondylar fractures of the humerus in children. Copyright 0 19% Elsevier Science Ltd.
Injury,
Vol.
27, No.
5, 303-305,
1996
Introduction Supracondylar fractures of the humerus are common in children. Closed reduction and percutaneous pin fixation has gained in popularity in its treatment. The original technique involves medial and lateral pinsl. Numerous variations in technique have been described to minimize the risk of ulnar nerve injury and to achieve sufficient stability2-4. These fractures are frequently associatedwith neurovascular complications, but the incidence of nerve injuries after treatment of supracondylar fractures of the humerus described in the literature is 10w~,~.
Table I. Data
Patient no. 1
2 3 4
of four patients
Patients
and results
Supracondylar fractures of the humerus in children are commonly treated at King Khalid University Hospital by closed reduction and percutaneous K-wire fixation. Between January 1993 and April 1995, 72 children were admitted with a supracondylar fracture of the humerus. Four patients were diagnosed as having ulnar nerve palsy following percutaneous fixation. Table I shows the details of four patients reported here. The pre- and postoperative radiographs are shown in Figures 1 and 2. All the patients had type III fractures (Pirone classification)5. There was difficulty locating the medial epicondyle due to swelling. More than one attempt was made to insert the K-wire accurately using a power drill. In Patient 1, there was severe pain as well as inability to move the little finger after surgery, so the medially placed wire was removed on the third day and replaced by another wire inserted through the lateral condyle - the nerve palsy recovered fully immediately. The other three patients presented with ulnar nerve palsy when they returned 3 weeks after the operation for removal of the wires. They were seenin the clinic weekly but they continued to have clawing of the ulnar two digits and an area of diminished sensationover little finger and hypothenar eminence.They all underwent exploration of the ulnar nerve. The nerve was found to be trapped by fibrous tissue behind the medial epidcondyle. It was apparent that the wires was passedthrough the sheath of the nerve which appeared to be normal proximal and distal to the area of tethering. The
with ulnar nerve palsy following percutaneouspinning
Age
(years)
Sex
5 4 4 3;
F M F M
Time of in&al surgery after injury (h)
8 i 10
Time of procedure done after removal wires (weeks)
Procedure
Removal of medially Exploration of nerve Exploration of nerve Exploration of nerve
placed
wire
4 4 8
of
Recovery (weeks)
Immediate 4 4 8
Injury:
International
Journal
of the Care of the Injured
Vol. 2 7, No. 5, 1996
Figure 2. Case 2. Anteroposterior radiographshowing supra-
condylar humeral fracture reduced and fixed with crossed percutaneousK-wires.
Figure 1. Case2. Lateral (B) radiograph of displacedsupra-
condylar humeralfracture. nerves were freed and placed anteriorly in the substanceof pronator teres. CasesNO. 2 and 3 showed early recovery following release of the nerve while the fourth patient recovered fully 8 weeks later.
Discussion Displaced supracondylar fractures of the humerus in children are best treated by closed reduction and percutaneous fixation by K-wire?. There is debate as to whether to use two crossed wires or two laterally placed wires. Kallio et al.3 describes two lateral divergent pins while Arino et al.’ recommends two lateral pins that may be either crossed or parallel. Zionts et al7 describes in cadavers that two crossedpins placed from the medial and lateral condyles provided the greatest resistanceto gross rotational displacement.Although there is always a risk of ulnar nerve darnage most authors have reported a low incidence of this complications’~‘. They describe a nerve injury as a transient neurapraxia due to forceful reduction of the fracture. The operative findings in this study are contrary to this explanation, since the wires were in fact
penetrating the sheathof the nerve and causingadhesions. The timing of initial surgery in all four caseswas 6 h after injury which is sufficient to causemarked swelling of the elbow. Under thesecircumstancesit isdifficult to locate the medial epicondyle. The use of a power drill to introduce K-wires increasesthe chancesof the sheath of the nerve becoming entangled. Multiple entry points also increase the chancesof nerve damage. Since these factors are responsible for neurological damagein these four patients we advise following Zionts’ and Kallio’s3 recommendation to use two lateral wires in situations where marked swelling of the elbow makessafe placement of a medial pin different. It is also wise either to use a hand drill for placing the medial wire or to make a smallopening to locate the medial epicondyle and to usea soft-tissue drill guide to introduce the wire safely. The incidence of ulnar nerve injury in this study is 5.5 per cent which is higher than previously recorded. Aronson et al9 and Flynn et a1.5described two patients with transient ulnar nerve palsy who recovered fully within 6 weeks. Royce et a1.4mentioned three patients with ulnar nerve injury with an incidence of 2 per cent after treatment with crossed wires. These patients with nerve injury were treated non-operatively by observation and all resolved completely within 6 months. In this series, Patients 2,~ and 4 did not show any improvement of ulnar palsy within an average of 6 weeks. This suggests that there was direct injury to the nerve or to its sheath. The operative findings confirmed this clinical impressionas the nerve was found tethered behind the medial epicondyle. These results suggestthat return of function takes longer if surgery on the nerve is delayed; it appears directly proportional to the timing of surgery. In conclusion, if there is no improvement of ulnar nerve functional after removal of K-wires in supracondylar fractures treated by crossedwires, exploration of the nerve should be considered early to achieve rapid recovery.
Ikram:
Ulnar nerve palsy
References Swenson AL. The treatment of supracondylar fractures of the humerus by Kirschner wire transfixation. ] Bone ]oitit Surg [Am] 1948;30A:993. Arino VL, Lluch EE, Ramirez AM, Ferrer J, Rodriguez L and Baixauli F. Percutaneous fixation of supracondylar fractures of the humerus in children. ] Bone Joint Surg [Am] 1977; 59A: 914. Kallio PE, Foster BK and Paterson D. Difficult supracondylar elbow fractures in children: analysis of percutaneous pinning technique. J Pediatr Orthop 1992; 12: II. Royce RO, Joseph DO, Dutkowsky JP, Kasser JR and Rand FR. Neurologic complications after K-wire fixation of supracondylar humerus fractures in children. J Pediatr Orfhop 1994; 11: 191. Flynn JC, Matthews JG and Benoit RL. Blind pinning of displaced supracondylar fractures of humerus in children. JBaneJoint Surg[Am] 1974; 56A: 263. Pirone AM, Graham HK and Krajbich JI. Management of displaced extension type supracondylar fractures of the
305 humerus in children. ] Bone joint Surg [Am] 1988; 7OA: 641. Zionts LE, McKellop HA and Hathaway R. Torsional strength of pin configuration used to fix supracondylar fractures of the humerus in children. ] Bone joint Surg [Am] 1994; 76A: 253. Nacht JL, Ecker ML, Chung SMK, Lotke PA and Das M. Supracondylar fracture of the humerus in children treated by closed reduction and percutaneous pinning. Clin Orfhop 1983; 177: 203. Aronson DC, Vollenhoven E and Meeuuwis JD. K-wire fixation of supracondylar humeral fractures in children: results of open reduction via a central approach in comparison with closed treatment. Injttry 1993; 24: 179. Paper accepted
18 January 19%.
Requeskfor reprints should be addressed to: Dr Mohammad Arshad Ikram FRCS, Senior Registrar, Division of Orthopaedics (49), King Khalid University Hospital, PO Box 7805, Riyadh 11472, Saudi Arabia.
c
1996
f+rry Vol. 27, No. 5, pp. 303-305. 1996 Elsevier Science Ltd. All rights reserved Printed in Great Britain 002C-1383/96 $15.00 + 0.00
ELSEVIER
PII: s0020-1383(96)00013-7
Ulnar nerve percutaneous the humerus
palsy: a complication following fixation of supracondylar fractures in children
of
M. A. Ikram Division of Orthopaedics, King Khalid University Hospital, Riyadh, Saudi Arabia
Fourchildren,who developed ulnar nerve palsy followingpercutaneous fixation of supracondylar fracture of the humerus by Kirschner wires (K-wires) are reported. In one the K-wire was removed within 48 hand the neuropraxia recovered immediafely. In the other three patients recovery took an average of 6 weeks after removal of the wires and only after exploration of the ulnar nerve. The nerve was found to be trapped behind the medial epicondyle of the humerus. Release and subsequent transposition of the nerve resulted in recovery. Certain measures are suggested to prevent this avoidable complication in the treatment of supracondylar fractures of the humerus in children. Copyright 0 19% Elsevier Science Ltd.
Injury,
Vol.
27, No.
5, 303-305,
1996
Introduction Supracondylar fractures of the humerus are common in children. Closed reduction and percutaneous pin fixation has gained in popularity in its treatment. The original technique involves medial and lateral pinsl. Numerous variations in technique have been described to minimize the risk of ulnar nerve injury and to achieve sufficient stability2-4. These fractures are frequently associatedwith neurovascular complications, but the incidence of nerve injuries after treatment of supracondylar fractures of the humerus described in the literature is 10w~,~.
Table I. Data
Patient no. 1
2 3 4
of four patients
Patients
and results
Supracondylar fractures of the humerus in children are commonly treated at King Khalid University Hospital by closed reduction and percutaneous K-wire fixation. Between January 1993 and April 1995, 72 children were admitted with a supracondylar fracture of the humerus. Four patients were diagnosed as having ulnar nerve palsy following percutaneous fixation. Table I shows the details of four patients reported here. The pre- and postoperative radiographs are shown in Figures 1 and 2. All the patients had type III fractures (Pirone classification)5. There was difficulty locating the medial epicondyle due to swelling. More than one attempt was made to insert the K-wire accurately using a power drill. In Patient 1, there was severe pain as well as inability to move the little finger after surgery, so the medially placed wire was removed on the third day and replaced by another wire inserted through the lateral condyle - the nerve palsy recovered fully immediately. The other three patients presented with ulnar nerve palsy when they returned 3 weeks after the operation for removal of the wires. They were seenin the clinic weekly but they continued to have clawing of the ulnar two digits and an area of diminished sensationover little finger and hypothenar eminence.They all underwent exploration of the ulnar nerve. The nerve was found to be trapped by fibrous tissue behind the medial epidcondyle. It was apparent that the wires was passedthrough the sheath of the nerve which appeared to be normal proximal and distal to the area of tethering. The
with ulnar nerve palsy following percutaneouspinning
Age
(years)
Sex
5 4 4 3;
F M F M
Time of in&al surgery after injury (h)
8 i 10
Time of procedure done after removal wires (weeks)
Procedure
Removal of medially Exploration of nerve Exploration of nerve Exploration of nerve
placed
wire
4 4 8
of
Recovery (weeks)
Immediate 4 4 8
Injury:
International
Journal
of the Care of the Injured
Vol. 2 7, No. 5, 1996
Figure 2. Case 2. Anteroposterior radiographshowing supra-
condylar humeral fracture reduced and fixed with crossed percutaneousK-wires.
Figure 1. Case2. Lateral (B) radiograph of displacedsupra-
condylar humeralfracture. nerves were freed and placed anteriorly in the substanceof pronator teres. CasesNO. 2 and 3 showed early recovery following release of the nerve while the fourth patient recovered fully 8 weeks later.
Discussion Displaced supracondylar fractures of the humerus in children are best treated by closed reduction and percutaneous fixation by K-wire?. There is debate as to whether to use two crossed wires or two laterally placed wires. Kallio et al.3 describes two lateral divergent pins while Arino et al.’ recommends two lateral pins that may be either crossed or parallel. Zionts et al7 describes in cadavers that two crossedpins placed from the medial and lateral condyles provided the greatest resistanceto gross rotational displacement.Although there is always a risk of ulnar nerve darnage most authors have reported a low incidence of this complications’~‘. They describe a nerve injury as a transient neurapraxia due to forceful reduction of the fracture. The operative findings in this study are contrary to this explanation, since the wires were in fact
penetrating the sheathof the nerve and causingadhesions. The timing of initial surgery in all four caseswas 6 h after injury which is sufficient to causemarked swelling of the elbow. Under thesecircumstancesit isdifficult to locate the medial epicondyle. The use of a power drill to introduce K-wires increasesthe chancesof the sheath of the nerve becoming entangled. Multiple entry points also increase the chancesof nerve damage. Since these factors are responsible for neurological damagein these four patients we advise following Zionts’ and Kallio’s3 recommendation to use two lateral wires in situations where marked swelling of the elbow makessafe placement of a medial pin different. It is also wise either to use a hand drill for placing the medial wire or to make a smallopening to locate the medial epicondyle and to usea soft-tissue drill guide to introduce the wire safely. The incidence of ulnar nerve injury in this study is 5.5 per cent which is higher than previously recorded. Aronson et al9 and Flynn et a1.5described two patients with transient ulnar nerve palsy who recovered fully within 6 weeks. Royce et a1.4mentioned three patients with ulnar nerve injury with an incidence of 2 per cent after treatment with crossed wires. These patients with nerve injury were treated non-operatively by observation and all resolved completely within 6 months. In this series, Patients 2,~ and 4 did not show any improvement of ulnar palsy within an average of 6 weeks. This suggests that there was direct injury to the nerve or to its sheath. The operative findings confirmed this clinical impressionas the nerve was found tethered behind the medial epicondyle. These results suggestthat return of function takes longer if surgery on the nerve is delayed; it appears directly proportional to the timing of surgery. In conclusion, if there is no improvement of ulnar nerve functional after removal of K-wires in supracondylar fractures treated by crossedwires, exploration of the nerve should be considered early to achieve rapid recovery.
Ikram:
Ulnar nerve palsy
References Swenson AL. The treatment of supracondylar fractures of the humerus by Kirschner wire transfixation. ] Bone ]oitit Surg [Am] 1948;30A:993. Arino VL, Lluch EE, Ramirez AM, Ferrer J, Rodriguez L and Baixauli F. Percutaneous fixation of supracondylar fractures of the humerus in children. ] Bone Joint Surg [Am] 1977; 59A: 914. Kallio PE, Foster BK and Paterson D. Difficult supracondylar elbow fractures in children: analysis of percutaneous pinning technique. J Pediatr Orthop 1992; 12: II. Royce RO, Joseph DO, Dutkowsky JP, Kasser JR and Rand FR. Neurologic complications after K-wire fixation of supracondylar humerus fractures in children. J Pediatr Orfhop 1994; 11: 191. Flynn JC, Matthews JG and Benoit RL. Blind pinning of displaced supracondylar fractures of humerus in children. JBaneJoint Surg[Am] 1974; 56A: 263. Pirone AM, Graham HK and Krajbich JI. Management of displaced extension type supracondylar fractures of the
305 humerus in children. ] Bone joint Surg [Am] 1988; 7OA: 641. Zionts LE, McKellop HA and Hathaway R. Torsional strength of pin configuration used to fix supracondylar fractures of the humerus in children. ] Bone joint Surg [Am] 1994; 76A: 253. Nacht JL, Ecker ML, Chung SMK, Lotke PA and Das M. Supracondylar fracture of the humerus in children treated by closed reduction and percutaneous pinning. Clin Orfhop 1983; 177: 203. Aronson DC, Vollenhoven E and Meeuuwis JD. K-wire fixation of supracondylar humeral fractures in children: results of open reduction via a central approach in comparison with closed treatment. Injttry 1993; 24: 179. Paper accepted
18 January 19%.
Requeskfor reprints should be addressed to: Dr Mohammad Arshad Ikram FRCS, Senior Registrar, Division of Orthopaedics (49), King Khalid University Hospital, PO Box 7805, Riyadh 11472, Saudi Arabia.