Humeral shaft fractures: a review Matt Walker, MD a , Brian Palumbo, MD b , Brian Badman, MD c , Jordan Brooks, BS d , Jeffrey Van Gelderen, MD e , Mark Mighell, MD a, * a Florida Orthopaedic Institute, Tampa, FL, USA b University of South Florida, Tampa, FL, USA c UAP Bone and Joint Union Hospital, Terre Haute, IN, USA d Foundation for Orthopaedic Research and Education, Tampa, FL, USA e New York University School of Medicine, New York, NY, USA Fractures of the humeral shaft are common, account for approximately 3% of all orthopaedic injuries, and result in a significant burden to society from lost productivity and wages. 19,47,64 Treatment modalities have greatly evolved since their first description in ancient Egypt (circa 1600 BC); however, fundamental management principles have remained consistent throughout time. 10 Nonoperative management continues as the mainstay for treatment of the majority of these injuries, with acceptable healing in more than 90% of patients. Surgical treatment is generally reserved for open fractures, polytrauma patients, ipsilateral humeral shaft and forearm fractures, and cases in which there is a failure to tolerate or maintain alignment in a functional brace. 11,19,56 Advances in internal fixation modalities have improved surgical outcomes. 6,14,38,62 Operative treatment can be performed via external fixa- tion, intramedullary nails, or plate-and-screw constructs, with each method resulting in predictably high union rates. 21,56 Despite the numerous surgical techniques, plate fixation remains the gold standard for fixation of humeral shaft fractures. Relevant anatomy and biomechanical considerations The humeral shaft is defined as the expanse between the proximal insertion of the pectoralis major and the distal metaphyseal flare of the humerus. Cylindrical in shape, the shaft inherently provides strength and resistance to both torsional and bending forces. Distally the bone transitions into a triangular geometry with the base posterior; the supracondylar region maintains a narrow anterior-posterior dimension. Important osseous landmarks of the humeral shaft include the deltoid tuberosity at the mid-anterolateral aspect, which serves as the insertion for the deltoid muscle, and the spiral groove posteriorly, which houses the pro- funda brachii artery and radial nerve as they traverse proximally to distally in a posterolateral direction. The humeral shaft serves as the insertion and origin site for several major muscles of the upper extremity. These play an important role in the biomechanical consequences of different fracture patterns. Muscles inserting on the shaft include the deltoid, pectoralis major, teres major, latissimus dorsi, and coracobrachialis; those originating on the shaft include the brachialis, brachioradialis, and the medial and lateral heads of the triceps brachii. In fractures occurring between the more proximal pectoralis insertion and the more distal deltoid insertion, the proximal fragment is adducted by the pull of the pectoralis and the force of the deltoid pulls the distal fragment upward and laterally. In comparison, fractures occurring distal to both insertions This is a review article where institutional review board approval was not required. *Reprint requests: Mark Mighell, MD, Florida Orthopaedic Institute, 13020 Telecom Pkwy N, Tampa, FL 33637. E-mail address: mmighell@floridaortho.com (M. Mighell). J Shoulder Elbow Surg (2011) -, 1-12 www.elsevier.com/locate/ymse 1058-2746/$ - see front matter Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2010.11.030
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This is a review
required.
*Reprint req
13020 Telecom
E-mail addre
J Shoulder Elbow Surg (2011) -, 1-12
1058-2746/$ - s
doi:10.1016/j.jse
www.elsevier.com/locate/ymse
Humeral shaft fractures: a review
Matt Walker, MDa, Brian Palumbo, MDb, Brian Badman, MDc, Jordan Brooks, BSd,Jeffrey Van Gelderen, MDe, Mark Mighell, MDa,*
aFlorida Orthopaedic Institute, Tampa, FL, USAbUniversity of South Florida, Tampa, FL, USAcUAP Bone and Joint Union Hospital, Terre Haute, IN, USAdFoundation for Orthopaedic Research and Education, Tampa, FL, USAeNew York University School of Medicine, New York, NY, USA
Fractures of the humeral shaft are common, account forapproximately 3% of all orthopaedic injuries, and result ina significant burden to society from lost productivityand wages.19,47,64 Treatment modalities have greatlyevolved since their first description in ancient Egypt (circa1600 BC); however, fundamental management principleshave remained consistent throughout time.10 Nonoperativemanagement continues as the mainstay for treatment of themajority of these injuries, with acceptable healing in morethan 90% of patients. Surgical treatment is generallyreserved for open fractures, polytrauma patients, ipsilateralhumeral shaft and forearm fractures, and cases in whichthere is a failure to tolerate or maintain alignment ina functional brace.11,19,56 Advances in internal fixationmodalities have improved surgical outcomes.6,14,38,62
Operative treatment can be performed via external fixa-tion, intramedullary nails, or plate-and-screw constructs,with each method resulting in predictably high unionrates.21,56 Despite the numerous surgical techniques, platefixation remains the gold standard for fixation of humeralshaft fractures.
article where institutional review board approval was not
uests: Mark Mighell, MD, Florida Orthopaedic Institute,
ee front matter � 2011 Journal of Shoulder and Elbow Surgery
.2010.11.030
Relevant anatomy and biomechanicalconsiderations
The humeral shaft is defined as the expanse between theproximal insertion of the pectoralis major and the distalmetaphyseal flare of the humerus. Cylindrical in shape, theshaft inherently provides strength and resistance to bothtorsional and bending forces. Distally the bone transitionsinto a triangular geometry with the base posterior; thesupracondylar region maintains a narrow anterior-posteriordimension. Important osseous landmarks of the humeralshaft include the deltoid tuberosity at the mid-anterolateralaspect, which serves as the insertion for the deltoid muscle,and the spiral groove posteriorly, which houses the pro-funda brachii artery and radial nerve as they traverseproximally to distally in a posterolateral direction.
The humeral shaft serves as the insertion and origin sitefor several major muscles of the upper extremity. Theseplay an important role in the biomechanical consequencesof different fracture patterns. Muscles inserting on the shaftinclude the deltoid, pectoralis major, teres major, latissimusdorsi, and coracobrachialis; those originating on the shaftinclude the brachialis, brachioradialis, and the medial andlateral heads of the triceps brachii. In fractures occurringbetween the more proximal pectoralis insertion and themore distal deltoid insertion, the proximal fragment isadducted by the pull of the pectoralis and the force of thedeltoid pulls the distal fragment upward and laterally. Incomparison, fractures occurring distal to both insertions
cause abduction of the proximal fragment due to thedeltoid, whereas the distal fragment is drawn proximallydue to the pull of the biceps brachii, coracobrachialis, andtriceps muscles.11,30
The blood supply to the humeral shaft is providedpredominantly by the nutrient artery, a branch off of thebrachial artery that penetrates at the proximal third of thehumerus on the medial side of the bone. The periosteumand the surrounding muscle bed also provide vascularity, toa lesser degree. Given the major role the nutrient arteryplays in nourishing the humeral shaft, its disruption eitherthrough traumatic or iatrogenic means can be detrimental tofracture healing. It should be protected and preservedduring surgical dissection.11,13,19,41
Regarding important neurologic structures, the median,ulnar, and radial nerves all lie in close proximity to thehumeral shaft. The median nerve travels adjacent tothe coracobrachialis muscle belly, directly medial to thehumerus and brachial artery, and provides no innervation tothe muscles proximal to the elbow.11,19,30 It is easily local-ized in the distal arm, where it lies on the anterior aspect ofthe brachialis muscle. In the proximal arm, the ulnar nerveruns in a similar fashion to the median nerve but liesposterior to the brachial artery. As the ulnar nerve travelsdistally, it pierces the medial intermuscular septum two-thirds the distance down, thus moving from the anterior tothe posterior compartment of the arm. It continues in theposterior compartment on its way toward the medial elbow.Like the median nerve, the ulnar nerve provides no inner-vation to muscles proximal to the elbow.11,30 Finally, theradial nerve, with its intimate and circuitous relationship tothe humerus, is of special interest when treating humeralshaft fractures. The nerve begins its descent down the arm asa terminal branch off of the posterior cord of the brachialplexus and then enters the spiral groove just posterior to thedeltoid tuberosity. It then courses posterolaterally adjacentto the bone, providing motor innervation to the tricepsmusculature. It finally exits the spiral groove on the lateralaspect of the humerus approximately 10 to 15 cm distal tothe lateral acromion; it is there that the nerve is tightly boundby the lateral intermuscular septum and, therefore, highlysusceptible to traction injury.11,19,24,29
History of humeral shaft treatment
Methods and materials used for immobilization of humeralshaft fractures have remained relatively unchanged over thepast several millennia. In the Edwin Smith Papyrus, circa1600 BC, Egyptians first described treatment of 3 humeralshaft fractures with splints made of cloth, alum, and honey.Thirteen hundred years later, the Greeks, in De Fracturis(415 BC), described the use of weights for traction duringclosed reductions and elaborated on specific methods ofsplinting with bandages soaked in cerate (an ointmentcomposed of lard mixed with wax) after reduction was
performed. The Roman author Celsus (25 BC to AD 50) thenpenned the medical text De Medicina, in which hedescribed different humeral shaft fracture patterns, as wellas benefits of fracture reduction including length restorationand reduction of pain. He also expanded on the Hippocraticmethods of splinting and described how tight bandagingcould cause gangrene of the extremity.10
Since the first narrative description, other varioussplinting techniques have come into vogue, includinghanging-arm casts, Thomas arm splints, modified Velpeaudressings, coaptation splints, shoulder spica casts, andabduction-type splints. Despite the various modifications intheme, the basic principle of fracture stabilization hasremained unchanged throughout time. The main limitationof many of these earlier splinting techniques was theimpairment imparted to the patient with regard to activitiesof daily living. These apparatuses extended from theshoulder to past the elbow, and the prolonged use requiredfor healing of humeral shaft fractures often resulted instiffness in both the shoulder and elbow. It was not until1977, when Sarmiento et al55 first described functionalbracing, that a major advancement was made and themodern era of splinting was introduced.
Since its first inception, functional bracing has becomethe gold standard for definitive management of the majorityof midshaft humeral fractures. A functional brace is anorthosis with an anterior and posterior prefabricated shellthat is contoured to accommodate the arm musculature(Fig. 1). Fracture stabilization is accomplished via thehydrostatic compressive forces of the surrounding softtissues and is not dependent on the rigidity of the splintingmaterial.72 As demonstrated by Sarmiento et al55 throughlaboratory analysis, the fracture callous created throughfunctional activity during the reparative process is morerobust and is mechanically stronger than that gainedthrough rigid immobilization. The advantage of this type ofbracing is that it avoids unnecessary immobilization ofother joints and allows for earlier restoration of motion andfunction to the injured extremity.
Current nonoperative management
It is important to stress that most transverse to short obliquehumeral shaft fractures are amenable to nonoperativemanagement and recommendations by some authors forimmediate surgical intervention are not supported by levelII studies.54,55,57 In a level III comparative study of extra-articular distal-third diaphyseal humeral fractures, theauthors concluded that although operative treatment resul-ted in more predictable alignment and a potentially quickerfunctional return, the operative risks were not insignificantand included loss of fixation (1), infection (1), and post-operative radial nerve palsy (3). Among the 19 patientstreated surgically, a 26% complication rate was reported.Comparatively, in the group that underwent brace treatment
Figure 1 A Sarmiento (functional) brace. The material isa thermoplast moldable splint with Velcro straps that can betightened as swelling subsides to allow continued compression onthe fracture. The brace is applied in a manner that allows shoulderand elbow motion.
Humeral shaft fractures 3
the end result in each case was a healed fracture withexcellent functional outcome, with only minor skincomplications due to local brace irritation noted. Advocatesfor surgical treatment should acknowledge that even incases in which brace treatment is a challenge, the literaturedoes not support the superiority of operative treatment.33
The current strategy for nonoperative managementinvolves the immediate immobilization of the injuredextremity via a coaptation splint, sling, and/or swath toprovide initial fracture stability, pain control, and resolutionof the edema. Once the majority of the soft-tissue swellingsubsides, typically after 10 to 14 days, the initial splint isexchanged for a functional brace that provides circumfer-ential soft-tissue compression.5,11,19,37,55,57 This type ofbracing is suitable for the majority of humeral shaft frac-tures and has the benefit of avoiding immobilization of theshoulder and elbow, which can lead to further morbidityincluding shoulder capsulitis and elbow stiffness.
When fitted properly, the brace should extend mediallyfrom 2.5 cm beneath the axilla to 1 cm proximal to themedial epicondyle. On the lateral aspect of the arm, the braceshould be placed so that it spans from just below the lateralacromion to a point just above the lateral epicondyle.55
Velcro straps that are fashioned around the brace are tight-ened periodically as the swelling subsides to maintain theconstant compressive environment during the reparativeprocess. Adequate placement of the orthosis will provideunhindered range of motion of the shoulder and elbow.Active motion of these joints should begin as soon astolerated. Use of the brace is typically continued for a periodof approximately 8 weeks, at which time it is discontinuedwith the assumption that, based on clinical and radiographic
examination, adequate fracture healing is confirmed.Bracing may be continued for a longer or shorter durationbased on each individual circumstance and the amount ofhealing evident both clinically and radiographically.
Nonoperative management of humeral shaft fracturesresults in predictably good outcomes, with acceptablealignment and healing occurring in more than 90% ofcases. In the largest clinical analysis to date, Sarmientoet al57 reported on 922 patients treated with a functionalbrace for both closed and open humeral shaft fractures. Intotal, 67% of patients were available for follow-up, andamong these patients, 98% of all closed injuries and 94% ofall open fractures healed. Malunion, described as angulardeformity greater than 16� in any plane, occurred in a varusposition and apex-anterior angulation 13% and 19% of thetime, respectively. Only 2% of patients reported loss ofshoulder motion exceeding 25� as compared with theuninjured side. Subsequent studies by Zagorski et al,72
Sharma et al,61 and most recently, Rutgers and Ring54
have corroborated these findings, with good clinicaloutcomes reported through functional bracing.
Frequently debated concerns regarding closed manage-ment of humeral shaft fractures pertain to the amount ofangulation that is acceptable for a good outcome and theproper management of an associated radial nerve injury.With regard to angular deformities, given the mobilityafforded by the shoulder and elbow, malunions of thehumeral shaft are well tolerated with minimal functionalimpairment.4,5,22,37,40,55,57,61,65 Parameters deemed accept-able for fracture reduction have included up to 30� of varusangulation, 20� of anterior bowing, and up to 15� of internalrotation; beyond these limits, cosmetic deformity andfunctional impairment may be shown clinically.35 In termsof neurologic sequelae, injury to the radial nerve withneurapraxia is the most frequently encountered nervedeficit associated with humeral fractures and is found in upto 18% of all patients.46 Spontaneous recovery overa period of 4 months occurs in 70% to 92% of patientsmanaged with observation; therefore, its presence is not anindication for open management and nerve exploration.51,60
Conversely, nerve loss after application of a brace orclosed reduction of the fracture is sometimes considereda relative indication for nerve exploration; however, nostudies document improvement with such management, andmost authors continue to recommend against operativeintervention.2,8
Limitations to functional bracing do exist and need to betaken into consideration when determining the appropriatetreatment strategy for each patient. Open fractures, specifi-cally Gustilo type III injuries with extensive soft-tissuestripping, are not amenable to bracing because of the woundcontamination, soft-tissue deficits, and inherent difficultieswith dressing care. These fractures are best managed withimmediate stabilization through internal or external fixationmeans.56 The decision to choose an external fixator is basedon the severity of the soft-tissue injury and the overall
4 M. Walker et al.
medical status of the patient.58 In the setting of grosscontamination with severe soft-tissue loss, external fixationcan provide an effective means to stabilize the fracture toprevent further soft-tissue injury and provide a stable envi-ronment conducive to soft-tissue healing. Conversely, insituations where the patient is not hemodynamically stablebecause of severe head or chest trauma, external fixation ofthe humeral fracture can aid in nursing care when access tothe chest or positioning of the arm is vital to proper venti-lation and oxygenation of the patient.
Fracture patterns with a high propensity for nonunionare also believed to be best managed by immediate fixationto potentially improve the healing rate. Fractures atparticular risk include humeral fractures associated withipsilateral brachial plexopathies and long oblique fractureswith proximal extension. Brien et al,9 in an analysis of21 patients with humeral shaft fractures and ipsilateralbrachial plexus injuries, found that nonunion developed in45% of patients treated nonoperatively. They hypothesizedthat muscle contractility is an essential component ofsuccessful brace treatment and believed that severe neuro-logic injury is a relative contraindication to conservativemanagement. A high risk of nonunion has also beenobserved in patients with long oblique fractures withproximal extension. Soft-tissue interposition between thefracture fragments occurs due to buttonholing of the sharpdistal fragment through the deltoid muscle belly. Toivanenet al63 and Rutgers and Ring54 reported 54% and 29%incidences of nonunion, respectively, for this type of injuryand supported close observation and possible early inter-vention if healing is not observed by 2 months.
Relative indications for surgery also include the cases of‘‘floating elbow’’ with concomitant fractures of thehumerus and both forearm bones, morbidly obese patientswhose bracing is uncomfortable or not feasible because ofthe impediments of the surrounding soft tissues, and casesin which closed management has failed.51,56
Surgical treatment of humeral shaft fractures
Operative management is a viable treatment method in theappropriate setting with the indications previously dis-cussed. The 2 primary methods of definitive operativefixation are intramedullary nailing (IMN) and compressionplating. External fixation, as previously noted, does playa role and is increasingly used in the polytrauma patient orcombat setting for temporary stabilization; however, its usefor definitive management of humeral shaft fractures islimited and not generally advised because of the concernfor deep injection.17
Intramedullary nailing
Implants used for intramedullary fixation of the humerusrange from both flexible nails and Kirschner wires to the
current trend of more rigid locking humeral nails. Smaller-diameter implants (Rush pins or Ender nails) are limited inefficacy because of an inability to obtain rotational or axialcontrol leading to numerous complications and the need foradditional supplementary fixation.12,59,68 Locking nailswere then introduced in hopes of better addressing thepitfalls associated with the preliminary devices and remainthe standard intramedullary implant used today. IMN istheoretically advantageous to plating from both a biome-chanical and surgical perspective. From a biomechanicalstandpoint, the intramedullary positioning of these devicesplaces them in line with the mechanical axis of the humeraldiaphysis, thereby subjecting the implant to lower bendingloads. In turn, by being centrally positioned, the nailfunctions in a ‘‘load-sharing’’ capacity and mitigates thepotential effects that stress shielding may play as comparedwith compression plating.18,31 With regard to surgicalbenefits, the nail is able to be introduced through a smallerincision, which allows a smaller surgical approach and lesssoft-tissue stripping as compared with plating techniques.Conditions better suited for intramedullary fixation includepathologic and impending pathologic fractures, segmentalinjuries, and fractures in osteopenic bone. Contraindica-tions to IMN include concomitant neurologic deficit, aswell as Gustilo and Anderson grade III open injuriesbecause of the concern for intramedullary contamination.
Modern intramedullary devices can be implanted ineither an antegrade or retrograde fashion with the decisionbased on the location of the fracture and the surgeon’s bias.Antegrade IMN is best suited for proximal- and middle-third fractures; however, its use for distal-third injurieshas also been reported. When one is performing an ante-grade technique, the anterolateral approach is the mostcommonly used. An incision is made longitudinally justinferior to the anterolateral corner of the acromion. Thedeltoid is split with care in line with its fibers to avoidinjury to the axillary nerve, which lies 4 to 5 cm distal tothe anterolateral acromion. The subdeltoid bursa is excisedto visualize the supraspinatus tendon, which is then splitatraumatically at its central portion. The nail is thenintroduced through the medial sulcus of the greater tuber-osity to gain intramedullary access (Fig. 2). In contrast,a retrograde technique is useful for management of frac-tures involving the middle portion of the diaphysis or distal-third of the humeral shaft. This approach is made via a 4- to5-cm incision overlying the posterior aspect of the distalhumerus in line with the olecranon tip. The triceps tendonis split and elevated in a subperiosteal fashion just proximalto the olecranon. The entry portal into the canal is thenlocated 1.5 to 2 cm proximal to the olecranon fossa.
The literature regarding management of humeral shaftfractures with locked humeral nailing has been inconsistentat best and has raised concerns based on the variouscomplications noted. One of the chief issues after bothantegrade and retrograde techniques has been the insertion-site morbidity created at the nail entry site. In the previous
Figure 2 Intramedullary nail of a humeral shaft fracture. Thestarting point for antegrade IMNs is the medial aspect of thegreater tuberosity.
Humeral shaft fractures 5
literature, the incidence of shoulder dysfunction has beenreported to range from 6% to as high as a 100%.32,49,50
Much of the problem is believed to be due to either sub-acromial impingement caused by a prominent nail or scartissue and/or damage to the rotator cuff in its critical zoneof hypovascularity creating chronic tendon tearing. Severalauthors have described different approaches with improvedoutcomes with the main lesson learned from these tech-niques being that avoidance of the avascular zone of therotator cuff and careful repair of the tendon after nailinsertion may attribute better outcomes and lessmorbidity.16,45 In fact, in a recent study by Rommens et al52
reported on 92 patients who underwent rigid unreamedhumeral nailing, only 2 patients (2.2%) reported shoulderdysfunction. Proponents of the retrograde technique wouldsafely counter that shoulder dysfunction is avoidedwith this approach but it is not without its own share ofcomplications, including iatrogenic supracondylar fracture,extension loss of the elbow, and heterotopicossification.20,53
Another commonly reported concern pertains to the rateof nonunion after intramedullary humeral fixation. Nonunionrates have ranged between 0% and 29% in the literature, withmany of the higher incidences having been noted in severalolder studies using first-generation implants such as theSeidel nail. In its early form, the Seidel nail had poor rota-tional stability,70 which likely allowed for fracture motion
and contributed to the relatively high incidence of nonunion,as noted in the study by Reimer, where a 25% nonunion ratewas reported.49 A recent level II prospective study by Putti etal,48 however, comparing modern locked humeral nails withdirect compression plating, found no significant difference inunion rates or functional outcomes but did note a statisticallysignificantly higher complication rate in the nail group.Interestingly, a meta-analysis originally done in 2006 andupdated in April 2010 found no statistical difference betweenplates and nails in the treatment of humeral shaft fractures;however, with the inclusion of the data of Putti et al, theauthors of the meta-analysis offered a reupdate thatconfirmed a higher risk of complicationwith nailing based onthe current body of literature.27,28 The ideal surgical treat-ment for these fractures continues to be a topic for debate.Although, historically, compression plating has beenconsidered the gold standard for surgical management,further large prospective studies must be performed beforea definitive conclusion can be drawn.6,27,28,42 Several recentprospective randomized studies have shown that althoughspecific complications may differ, both union rates andfunctional results are comparable between nailing andplating of humeral shaft fractures (Table I).
Open reduction/internal fixation
Open reductioneinternal fixation continues to be themainstay of operative management for humeral shaft frac-tures and is the treatment of choice of the senior authors(B.B. and M.M.). Fixation techniques described includestandard direct compression plating with or without lagscrew fixation (Figs 3 and 4), bridge plating strategies forspanning of comminuted segments, and locking and hybridlocking techniques, which have been increasingly used inthe setting of comminution or osteopenic bone. Basic AO/Orthopaedic Trauma Association principles are recom-mended when pursuing any of these techniques and areparamount to successful fracture healing.
Open reductioneinternal fixation of humeral shaftfractures can be performed through a variety of approaches.The selection of a surgical approach by the operatingphysician is dictated by the his or her experience, thelocation of the fracture, and the presence of a concomitantradial nerve injury. A detailed description of each approachto the humerus is beyond the scope of this review; however,one may refer to the recent publication by Zlotolow et al74
for a better understanding of the relevant anatomy.31 Eachexposure possesses its own pearls and pitfalls, and a thor-ough appreciation of these and a general knowledge of theanatomy can aid the surgeon in efficiently achievingoptimal fracture management. The anterolateral approach isuseful for exposure of fractures involving the proximal andmiddle thirds of the humeral shaft. The benefits of thisapproach include its extensile nature and its avoidance ofthe radial nerve. A posterior approach may be better suited
Table
IProspective
comparativestudiesofIM
Nversusplate
fixationofhumeral
shaftfractures
Author
Study
design
No.of
cases
Fixation
method
Union
(%)
Meantime
tounion(w
k)Goodto
excellent
results
Reoperation
(%)
Complications
(%)
Notes
Chapman
etal14
(2000)
Prospective
38
IMN
95
9.8
NR
313
6patients
had
shoulder
painand
stiffness
46
Plate
93
10.4
NR
715
6patients
had
elbowpainandstiffness
McCorm
ack
etal39(2000)
Prospective
13
IMN
85
NR
NR
46
77
22
Plate
95
NR
NR
513
Putti
etal48(2009)
Prospective
16
IMN,unream
ed,
rigid
100
NR
NR
650
3devicerelated3capsulitis2
radialnerve
palsy
18
Dynam
iccompressionplate
94
NR
NR
617
Implantfailureinfectioncapsulitis
Singisettiand
Ambedkar62(2010)
Prospective
25
IMN
95
50%
ofcases
before
16wk
65
88
1infectiontrxwithIþ
D,
1nonuniontreatedexchangenailing
20
Plate
93.75
75%
ofcases
before
16wk
94
10
15
1radialnerve
palsy,1infectiontreated
withIþ
D,1nonuniontreatedwith
bonegraftingandplating
IMN,antegradeintram
edullarynailing;NR,notreported.
6 M. Walker et al.
for fractures extending between the olecranon fossa anddistal middle-third of the humerus. This approach alsoaccommodates very distal plating of the humerus along theposterolateral column, where additional fixation into theposterior capitellum is critical for stability of the distalsegment (Figs. 5 and 6). The triceps tendon can be eithersplit midline (triceps splitting) or released medially andlaterally and mobilized (triceps sparing) to allow visuali-zation of the bone. In both techniques, the radial nerve mustbe dissected and identified to avoid iatrogenic injury fromeither cutting it during exposure or plating over it duringfracture fixation. Finally, should a vascular injury bepresent, the anteromedial approach may be of benefitbecause of the direct access it affords to the neurovascularbundle.
We believe that a triceps-sparing technique providessuperior exposure to the posterior humerus, and it is ourstandard approach for most distal-third shaft fractures(Figs. 6 and 7). The benefits of this approach include itsextensile nature should proximal exposure be necessary andits direct access to the radial nerve should a laceration existat the time of fracture necessitating concomitant nerverepair. The skin incision is made midline. The posteriorantebrachial cutaneous nerve is then visualized traversinginto the lateral skin flap. It is then traced back proximally toassist in identification of the radial nerve. Once the nervehas been identified, a Penrose drain is placed around it toassist in subsequent mobilization. The triceps musculatureis then reflected medially to expose the humeral shaft. Incases that require more cephalad exposure, the triceps issplit between the long and lateral heads. It is here that theradial nerve is identified and protected.
Basic AO/Orthopaedic Trauma Association principlesshould be applied when performing plate fixation ofhumeral shaft fractures including restoration of anatomicalignment, avoidance of soft-tissue stripping to preservevascularity to the fracture fragments, and provision ofstable rigid fixation to allow for early range of motion andoptimal functional recovery. In situations of comminutionor in the presence of oblique or spiral patterned fractures,lag screw fixation should be used to both simplify thefracture and maximize inter-fragmentary compression.Plates applied in this setting function as a neutralizationdevice protecting the lag screw from torsional or axialforces. When possible, lag fixation through the plate canprovide further added construct stability. We currently usea bone tenaculum for fracture reduction and then performlag screw fixation, and we have found this to be moreeffective than provisional K-wire fixation. To minimizedamage and splintering of smaller fragments, use of small-fragment or mini-fragment screws may be of additionalbenefit. In the setting of high-energy trauma and severelycomminuted fracture patterns, anatomic reduction may notbe feasible, and bridge plating techniques to maintainalignment and provide fracture stability may be moreappropriate in these circumstances. Using a longer plate to
Figure 4 Lag screws and compression plating of comminutedhumeral shaft fracture.
Figure 3 Humeral shaft fracture treated with 2 lag screws andcompression plate.
Humeral shaft fractures 7
obtain a greater working length is recommended whenbridging a comminuted segment. Excision of comminutedfracture fragments and subsequent shortening of thehumerus through direct compression plating of the prox-imal and distal segments also comprise a potential treat-ment option in the face of severe comminution. Concernsregarding the effects of humeral shortening on the biome-chanical forces of arm musculature have been studied andshould be considered when one uses this technique,understanding that shortening greater than 2 cm may resultin significant muscular weakness.31
The role of locking or hybrid locking plating techniquesfor humeral shaft fractures remains a topic of debate. In thesetting of normal-quality bone and simple fracture patterns,standard compression plating remains an effective techniquefor humeral shaft fracture fixation from both a biomechan-ical and cost perspective. In a recent study comparinglocking plates with non-locking plates for a comminutedmidshaft fracture model, no biomechanical advantage wasnoted with regard to torsion, bending, or axial stiffnessbetween the 2 constructs.44 Locking screws are also costly,averaging 5 times greater than their non-locking 3.5-mmcounterpart ($134 vs $27; 2010 Synthes, Inc. [West Chester,PA, USA] pricing). In the face of rising health care costs andwith the lack of biomechanical superiority, their use should
be minimized or avoided in the setting of good bone stock. Incomparison, when faced with poor bone quality, the use oflocking plates may be advantageous. In a biomechanicalstudy by Gardner et al23 in an osteoporotic fracture model,the unlocked screw constructs had significantly loweredstability compared with the locked constructs, as shown bya loss of stiffness under cyclic loading. In the setting ofosteoporosis, therefore, locking plates may provide betterstability and avoid the inherent risks of fixation failure andnonunion that could occur with standard plates. Interest-ingly, Gardner et al also found no difference in hybridconstructs (combining locking screws and non-lockingscrews in the same plate) as compared with all-lockedconstructs. This finding may help mitigate costs becausestandard screws that may be used for initial compression ofthe plate to the bone may be left in place without unduebiomechanical consequences and do not have to be replacedby more expensive locking screws in circumstances wherelocking fixation is deemed necessary.
For most transverse fractures, compression with a broad4.5-mm dynamic compression plate is recommended toachieve primary bone healing. The broad 4.5-mm plateincorporates staggered screw holes in its design, a featurethat helps to prevent splintering of the humerus and prop-agation of existing fracture lines. The 4.5-mm plate can beused for most humeri of adequate size. However, forsmaller patients, a narrow 4.5-mm dynamic compressionplate is recommended. Pre-bending of the plate prevents
Figure 5 Posterior ‘‘triceps-slide approach.’’ This posteriorapproach keeps the triceps intact and slides the muscle belly fromlateral to medial for plate application. The radial nerve, posteriorbrachial cutaneous nerve, and axillary nerve are well illustrated.
Figure 6 Posterior ‘‘triceps-split approach.’’ This approachsplits the triceps muscle belly between the medial and lateralheads, moving the radial nerve laterally and allowing for plateapplication beneath the nerve.
8 M. Walker et al.
gapping of the fracture at the opposite cortex. Ideal plateosteosynthesis should include a minimum of 6 cortices’fixation above and below the fracture, although 8 corticesare preferable. An articulated tensioner or a Verbruggeclamp with a push-pull screw can be used to maximizecompression at the fracture site (Fig. 8).
Minimally invasive techniques have been described andused effectively. Zhiquan et al73 prospectively evaluated 13patients treated with a minimally invasive anterior platingtechnique with a 4.5-mm dynamic compression plate.Union occurred in all patients, with a mean healing time of16.2 weeks (range 12-32 weeks), with no incidences ofnonunion, implant failure, or radial nerve palsies andexcellent results regarding elbow function. Apivatthakakulet al3 anatomically evaluated the feasibility of minimallyinvasive anterior plating and confirmed that it was clinicallysafe as long as plating occurred with the arm maximallysupinated to avoid injury to the radial nerve. Advantages ofthis technique include less soft-tissue dissection ascompared with open plating and the possibility of earlierreturn of shoulder and elbow range of motion.36
Open fractures of the humeral shaft should be treated inaccordance with general principles of open fracturemanagement including adequate debridement, appropriatepreoperative and perioperative antibiotic prophylaxis, andtetanus toxoid and antibody as indicated. Rigid fracture
fixation should be performed as soon as the wound isadequately debrided and the patient is medically stable.7,34
Use of temporary external fixation as discussed previouslymay be advantageous in the setting of severe woundcontamination to aid with subsequent surgical debride-ments and immediate stabilization of the extremity.
Outcomes of plate fixation of humeral shaft fractures aregenerally very good, with union rates in the 92% to 96%range, time to union averaging around 12 weeks, andcomplication rates ranging from 5% to 25%.15,25,26,42,43,67,69
Complications of the surgical treatment of these fracturesare similar to those related to the surgical management ofother fractures including infection, nonunion, malunion,neurovascular injury, and the need for additional surgery.Iatrogenic injury to the radial nerve is possible with mostapproaches to the humeral shaft, so its location should berecognized with all open dissections.
Complications
Nonunion
Even with adequate operative or nonoperative techniques,nonunion develops in a significant percentage of humeralshaft fractures. Nonoperative management can be associated
Figure 8 Push-pull screw compression. One technique toincrease compression across a fracture is to place a push-pullscrew a short distance from the end of the plate; a Verbruggeclamp can be used to pull the plate toward the screw after fixationof the plate to the distal fragment.
Figure 7 The posterior approach can be extended proximallyand distally for long plate application.
Humeral shaft fractures 9
with nonunion rates as high as 10% of cases,54 whereasoperative techniques can result in even higher rates ofnonunion, up to 30%.66 Thus, it is important to understand thebiology and treatment options for humeral shaft nonunions.Nonunions can be problematic, but excellent results can beachieved by appropriate identification of the type ofnonunion and adhering to sound treatment principles at thetime of operation.
In general, nonunions of fractures fall into 3 distinctcategories, and their treatment can be generalized accord-ing to the type of nonunion. The most common type ofnonunion is the atrophic nonunion, which is essentiallya failure of biology at the fracture site. Treatment for thistype of nonunion is aimed at enhancing the biologic milieuof the fracture site to make it more hospitable for fracturehealing. Strategies include bone grafting and the use ofbone morphogenic protein compounds to enhance healing.In contrast, a hypertrophic nonunion is a problem ofmechanical stability, where the bone is trying to heal butthe mechanical instability at the fracture site preventscomplete osseous union. Treatment goals, therefore,involve enhancing the stability of the fixation construct.The final type of nonunion is the infected nonunion.Treatment of this problem requires debridement of necrotictissue, treatment of the infection, and establishment ofa stable mechanical construct to aid in fracture healing.
For atrophic nonunions, we prefer a technique that wasoriginally described by Wright et al.71 This procedure usesan intramedullary allograft fibular strut and a compressionplate and allows for restoration of medullary blood flow and
reconstruction of the humeral shaft. By use of this tech-nique, Wright et al achieved a 89% union rate at 3.5 monthspostoperatively. We have used this technique in a consecu-tive series of 20 patients presenting with an atrophicnonunion of the humeral diaphysis; each patient was treatedby compression plating and an intramedullary allograftstrut. A union rate of 95% was observed in our series. Thistreatment failed in 1 patient who had a gunshot wound andmultiple previous surgical attempts at fixation and, ulti-mately, refused further surgical intervention.
Radial nerve injury
Radial nerve injury is a common complication of humeralshaft fractures, occurring in up to 18% of closed injuries.46
Most commonly, radial nerve injuries are associated withmiddle one-third spiral humeral shaft fractures.60 Fortu-nately, recovery can be expected with observation alone in90% at 4 months after injury.46 In the scenario of closedhumeral shaft fractures with concomitant radial nervepalsies, surgical exploration is not required. Indications forsurgical exploration of the radial nerve include neurologiccompromise after closed reduction of a humeral shaftfracture, open fractures with associated radial nerve palsies,radial nerve palsy after a penetrating injury, and spiral or
Figure 9 Holstein-Lewis fracture. This fracture is known fora high incidence of radial nerve palsies.
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oblique fracture patterns in the middle to distal one-third ofthe humeral shaft (ie, Holstein-Lewis fracture) (Fig. 9) withassociated radial nerve palsy.46 Radial nerve dysfunctionafter attempts at closed reduction of the associated fracturemay represent nerve laceration due to reduction maneuveror nerve interposition between fracture fragments.46
Without objective clinical signs of radial nerve recovery6 weeks after the injury (ie, return of brachioradialis,extensor carpi radialis longus, and brevis muscle function),electromyography (EMG) and nerve conduction studiesshould be performed to evaluate nerve function. In thepresence of muscle action potentials on EMG testing,observation of the radial nerve for recovery should becontinued. However, in the presence of denervation wherefibrillation potentials will be observed, EMG and nerveconduction studies should be repeated at 12 weeks afterthe injury. In the absence of recovery at 12 weeks, asindicated by clinical examination and neurophysiologictesting, surgical exploration of the radial nerve is recom-mended. Should the radial nerve not recover, tendontransfer procedures have shown success for the treatment ofradial nerve palsy.1
Summary
Humeral shaft fractures are common orthopaedicinjuries that can often be managed nonoperatively with
high union rates and excellent results as the generaloutcome. Specific indications exist for operativemanagement and include polytrauma patients, openfractures, certain fracture patterns, and failure to main-tain an acceptable closed reduction. Plate fixation ofhumeral shaft fractures has historically been consideredthe gold standard of operative management based ona lower complication rate; however, newer intra-medullary devices may prove as effective in fracturemanagement pending future prospective analysis.Although radial nerve palsy remains a vexing andcommon comorbidity of humeral shaft fracturemanagement, recovery can be expected in mostcircumstances.
Disclaimer
The authors, their immediate families, and any researchfoundations with which they are affiliated have notreceived any financial payments or other benefits fromany commercial entity related to the subject of thisarticle.