Cutting edge Orthopedics

Supracondylar Humerus Fractures • 7  meta-analysis performed by Babal and colleagues (2010), transient neuropraxia occurred in 11.3% of all displaced supracondylar humerus fractures [31]. Extension-type injuries are most com- monly associated with injuries to the anterior interosseous nerve (AIN) (Fig. 7) [31–34]. Injury to the AIN is followed by radial nerve, median nerve, ulnar nerve, and posterior interosseous nerve (PIN) injuries, in decreasing order of frequency [31, 35]. Posterolateral displacement increases the risk of injury to the AIN and median nerve, while posteromedial displacement increases the risk of injury to the radial nerve and PIN [19, 26]. Additionally, iatrogenic nerve injuries associated with surgical management of extension-type nerve injuries have been reported to occur in 3% of cases [35]. Conversely, ulnar nerve injuries are most common in flexion-type supracondylar humerus fractures [13, 31]. Median nerve injuries have also been associated with flexion-type supracondy- lar fractures but occur less often than ulnar nerve injuries [31]. Combined neurologic and vascular injuries have also been reported with concomitant inju- ries to the median nerve and brachial artery [26, 30, 36]. Mangat and colleagues (2009) suggested that when both the median nerve and brachial artery are injured, entrapment in the fracture site should be suspected [30]. In their cohort, tethering or entrapment of the nerve requiring release was identified in all patients with preoperative AIN or median nerve deficits and a pink pulseless hand. Therefore, early exploration of patients with concomitant AIN/median nerve and brachial artery injuries was recommended [30]. Luria and colleagues (2007) also suggested combined neu- rologic and ischemic symptoms as an indication for nerve exploration [37]. Compartment syndrome may also occur with supracondylar humerus fractures following injury or fixation. In isolated supracondylar fractures, compartment syndrome occurs at a rate Fig. 7: Clinical photograph depicting an anterior interosseous nerve (AIN) palsy following an extension-type supracondylar fracture. Note the lack of thumb and index finger flexion at the interphalangeal (IP) and distal interphalangeal (DIP) joints, respectively (Courtesy of Joshua M. Abzug, MD). 41 pe supra- itant dis- occurs in ctures [ 5 , ue to the over the rly if the he supra- [ 19 , 25 ]. contused, jury that ed occlu- or fully le for the e fracture ry or dur- Brachial with pos- fragment displace- o occur in humerus es (1995) ately 42% humerus rmed by uropraxia acondylar juries are the ante- [ 31 – 34 ]. e, median ous nerve ency [ 31 , the risk of e postero- injury to nally, iat- ical man- have been ost com- erus frac- have also been associated with flexion-type supracondylar fractures bu occur less ofte than ulnar nerve injuries [ 31 ]. Combined neurologic and vascular injuries have also bee reported with concomitant injuries to the median nerve and brachial artery [ 26 , 30 , 36 ]. Mangat and colleagues (2009) suggested that when both the median nerve and brachial artery are injured, entrapment in the fracture site should be sus- pected [ 30 ]. In their cohort, tethering or entrapment of the nerve requiring release was identified in all patients with preoperative AIN or median nerve deficits and a pink pulseless hand. Therefore, early exploration of patients with concomitant AIN/ median nerv and brachial artery injuries was rec- ommende [ 30 ]. Luria and colle gues (2007) also suggested combined neurol gic and ischemi symp- toms as an indication for nerve exploration [ 37 ]. Compartment syndrome may also occur with supracondylar humerus fractures following Fig. 4.7 Clinical photograph depicting an anterior inter- osseous nerve (AIN) palsy following an extension-type supracondylar fracture. Note the lack of thumb and index finger flexion at the interphalangeal (IP) and distal inter- phalangeal (DIP) joints, respectively (Courtesy of Joshua M. Abzug, MD)