clavicle fractures account for up to 10% of all fractures and are typically sustained by young , active males.[13 ] most nondisplaced , minimally comminuted shaft fractures are treated nonoperatively and heal without complication . most stable lateral clavicle fractures heal without event as well , although unstable distal clavicle fractures have a higher nonunion rate of up to 30% . overall , the nonunion rate after nonoperative treatment of clavicle fractures is rare , reportedly ranging from less than 1 to 4.5% . however , female gender , age , fracture displacement , fracture stability , and comminution have been shown to increase this nonunion risk in some studies to between 33 and 47% . patients may present with mechanical symptoms , intractable pain , motion restriction , and even thoracic outlet syndrome . open reduction and internal fixation ( orif ) with autologous iliac crest bone graft ( icbg ) has been the gold standard to address clavicular shaft nonunions . a review of the literature demonstrates healing rates ranging from 89 to 100%.[1481011 ] although icbg is very effective for fracture healing , complications from graft harvest can potentially cause significant morbidity . major complications such as pelvic fracture , infection , prolonged pain , and minor complications such as persistent drainage , sensory disturbances , and temporary pain range from 0.7 to 25% and 9.4 to 24% , respectively.[1219 ] hip pain has been shown to persist as long as six months postoperatively in 37.9% of patients . even with meticulous technique , the potential for graft - site complications and their associated morbidity remains and continues to be a substantial concern for the treating surgeon . in an effort to minimize graft - site complications , alternative methods to augment healing have emerged . orif with demineralized bone matrix ( dbm ) rather than icbg has shown equal efficacy in treating nonunions of the humerus and tibia , and variable enhancement of fusion rates in the spine without the associated morbidity of graft harvest . performed a retrospective analysis of superior plate fixation in the treatment of clavicular nonunions citing a 93% healing rate . however , only 29.8% of these patients were treated with dbm and the other 63.8% were treated with local autogenous graft  thus , the study was not just evaluating the use of allograft alternatives . in addition , they did not differentiate healing rates in those with dbm vs those with autogenous graft . thus , no series exists demonstrating the efficacy of orif with allograft bone substitute alone when treating clavicular nonunion . the purpose of this investigation was to evaluate the clinical outcomes , radiographic healing , and complication rate of clavicle nonunions treated with orif and allograft bone substitute . the records of two shoulder surgeons at a tertiary referral center over the previous five years ( 2004 - 2009 ) were retrospectively reviewed to identify all clavicle nonunions requiring operative intervention . inclusion criteria consisted of any patient between the ages of 18 to 89 years with a symptomatic clavicular nonunion . a nonunion diagnosis was based on radiographic [ figures 1 and 2 ] as well as clinical exam findings consistent with a symptomatic nonunion ( continued pain , mechanical symptoms , tenderness , and/or crepitus on exam ) . these patients presented for operative fixation due to their persistent symptoms and failure of conservative management . based on these criteria , five patients were excluded , two due to segmental defects requiring iliac crest corticocancellous graft , one due to incarceration , one due to suture fixation of a distal clavicle fracture , and one due to death unrelated to the surgery , two months postoperatively , preventing postoperative evaluation . union demonstrated after fixation ( b ) ; patient had radiographic and clinical evidence of union after fixation clavicle nonunion ( a ) . no radiographic evidence of complete union ( b ) despite full strength , range of motion and no pain on clinical exam . fracture line still visible eight months postoperatively ( arrow ) we recorded information about the subject 's age , clavicular nonunion location , type , duration , range of motion , strength , tobacco use , length of postoperative follow - up , clinical and radiographic evidence of healing , and any complications . the nonunion site was identified , debrided of fibrous tissue and/or attempted callus to expose bleeding bone edges . the debrided nonunion site was then reduced and fixed on the superior surface of the clavicle with a precontoured locking clavicle plate . all plate fixation constructs achieved a minimum of three screws medial and lateral to the nonunion site . one of the following healing adjuncts was placed at the nonunion site : 12 received platelet - rich plasma ( prp ) with dbm and the other seven received allograft corticocancellous chips . in one case , the allograft chip was supplemented with rhbmp-2 , and in a second case , another with calcium phosphate cement . patients were discharged home the same day of surgery with a sling for the first six weeks . patients then progressed to active shoulder range of motion over the next six weeks as their symptoms allowed . at each postoperative visit , the investigators examined patients for tenderness to palpation over the nonunion site , active and passive range of motion , and strength at the shoulder . radiographs were taken at the six - week and three- , six- , and 12-month visits and evaluated for bridging callus in two views . patients were allowed to return to full activity when they had radiographic evidence of healing , no clinical tenderness , and return of full pain - free strength , comparable with the contralateral side . the nonunion site was identified , debrided of fibrous tissue and/or attempted callus to expose bleeding bone edges . the debrided nonunion site was then reduced and fixed on the superior surface of the clavicle with a precontoured locking clavicle plate . all plate fixation constructs achieved a minimum of three screws medial and lateral to the nonunion site . one of the following healing adjuncts was placed at the nonunion site : 12 received platelet - rich plasma ( prp ) with dbm and the other seven received allograft corticocancellous chips . in one case , the allograft chip was supplemented with rhbmp-2 , and in a second case , another with calcium phosphate cement . patients were discharged home the same day of surgery with a sling for the first six weeks . patients then progressed to active shoulder range of motion over the next six weeks as their symptoms allowed . at each postoperative visit , the investigators examined patients for tenderness to palpation over the nonunion site , active and passive range of motion , and strength at the shoulder . radiographs were taken at the six - week and three- , six- , and 12-month visits and evaluated for bridging callus in two views . patients were allowed to return to full activity when they had radiographic evidence of healing , no clinical tenderness , and return of full pain - free strength , comparable with the contralateral side . the 19 patients included in this study were treated with orif and allograft bone substitute . a mean of 19 months elapsed between initial injury and presentation ( range , 2.5 - 120 months ) . average follow - up was 15 months ( range , 2.5 - 48 months ) . patient 11 was only followed up for 2.5 months after their surgery due to clinical and radiographic evidence of healing and demonstration of full function at that time . overall , initial radiographic evidence of healing was obtained in 13/19 ( 68% ) patients[figure 1b ] . one patient could not afford final radiographs but had eight months of clinical follow - up and is clinically healed . two patients without radiographic evidence of healing exhibited clinical signs of union by examination[figure 2b ] . they did not have any hardware complications , had no further interventions , and returned to full function . these patients had no pain , achieved full strength in resisted forward elevation and external rotation , and achieved range of motion equal to the contralateral side and were satisfied with their result . one of these occurred in a patient with hypertrophic nonunions , while the other two were in patients with atrophic nonunions . three patients had failures requiring revision fixation , and two of these were catastrophic failures . patient 10 had four total surgeries , including revision orif after the initial plate fixation pulled out . he then underwent two subsequent irrigation and debridement procedures for persistent hematoma and then removal of hardware after a stress fracture developed medial to his plate . this patient 's nonunion persisted , and he did not wish any further attempts at fixation . overall , 2 of the 3 persistent nonunions did go on to eventual union , bringing the final radiographic union rate up to 80% and final clinical healing rate up to 95% . each of the three patients with a persistent nonunion were smokers ( average 0.8  pks / day ) and continued to smoke during treatment despite advice to the contrary . this rate of persistent nonunion in smokers approached statistical significance ( p=0.08 ) compared with those who went on to clinical union . the two patients with clinical evidence of healing , but not radiographic evidence of healing , were not smokers . there was no difference in complication rate in those with allograft corticocancellous chips vs those with prp and dbm . one of these occurred in a patient with hypertrophic nonunions , while the other two were in patients with atrophic nonunions . three patients had failures requiring revision fixation , and two of these were catastrophic failures . patient 10 had four total surgeries , including revision orif after the initial plate fixation pulled out . he then underwent two subsequent irrigation and debridement procedures for persistent hematoma and then removal of hardware after a stress fracture developed medial to his plate . this patient 's nonunion persisted , and he did not wish any further attempts at fixation . overall , 2 of the 3 persistent nonunions did go on to eventual union , bringing the final radiographic union rate up to 80% and final clinical healing rate up to 95% . each of the three patients with a persistent nonunion were smokers ( average 0.8  pks / day ) and continued to smoke during treatment despite advice to the contrary . this rate of persistent nonunion in smokers approached statistical significance ( p=0.08 ) compared with those who went on to clinical union . the two patients with clinical evidence of healing , but not radiographic evidence of healing , were not smokers . there was no difference in complication rate in those with allograft corticocancellous chips vs those with prp and dbm . despite the success of orif with icbg in treating clavicular nonunions , extensive literature exist exploring alternative fixation constructs and biologic adjuncts in an attempt to minimize potential graft - site morbidity . in their study evaluating external fixation of clavicle fractures and nonunions , schiund et al . healed all five nonunions treated with a hoffmann external fixator with no re - fractures . achieved 95% healing rates with hagie pin fixation , corticoperiosteal first rib , and icbg . they cited incisional cosmesis with langer 's lines , load sharing with intramedullary fixation , and ease of hardware removal as benefits to intramedullary fixation . however , unlike a plate and screw construct , the pin does not provide rotational control . this led the authors to restrict forward elevation above 90 degrees in the early stages of rehabilitation . there was a significant rate of hardware irritation as pin removal occurred in 17 patients ( 81% ) due to a painful bursa forming at the lateral end of the clavicle ; two pins broke during removal . despite this , they reported no graft - site complications , although most surgeons do not have a comfort level with obtaining corticoperiosteal first rib grafts . however , the complication rate with the use of the hagie pin has ranged 25.8 to 50% and to some degree , has limited their overall use . fifty - three to 66% of these complications are from skin irritation or persistent pain ; yet , the nonunion rate when using this construct in the acute setting is only 8.6% . in examining graft choices , icbg remains the gold standard , and the morbidity associated with obtaining it has been well studied . complication rates for harvesting icbg vary significantly in the literature , based on procedure , graft site , and designation of major and minor complications . reported major complications ( hernia , pain > 6 months ) to be 8% and 2% for anterior and posterior icbg , respectively . the minor complication rate ( superficial hematomas , temporary pain / sensory disturbances ) was 15% and 0% for anterior and posterior grafting , respectively . similarly , younger and chapman reported major and minor complication rates of 5.3 and 25% , respectively , for anterior icbg sites and 11.3 and 18.4% , respectively , for posterior grafting sites . however , when positioning a patient for fixation of a clavicle nonunion , this step would add significant time and complexity to the operation . because of this complication rate , alternative graft sources are becoming more frequently studied to determine if healing rates are acceptable given the decreased morbidity . tashjian and horwitz infused tricalcium phosphate with iliac crest aspirate during open reduction and plate fixation in ten clavicle nonunions and reported a 90% healing rate with no graft - site complications . vascularized corticoperiosteal bone grafts from the medial femoral condyle and vascularized fibula strut grafts demonstrate excellent healing capabilities , with 100% healing rates . the authors caution that these vascularized grafts should be used for refractory nonunions or in adverse healing environments such as an irradiated tissue bed . therefore , they are an unlikely source of graft for the first - time treatment of a clavicle nonunion . like the vascularized bone grafts , dbm has shown success with bone healing in other clinical trials . dbm is created from allograft bone demineralized with acid extraction , leaving collagen and non - collagenous proteins , including growth factors . the osteoinductive potential of the graft is influenced by a number of factors : the sterilization process , the carrier , the total amount and ratios of bone morphogenetic protein ( bmp ) present.[3032 ] hierholzer et al . compared dbm with icbg in their series of humeral nonunions treated with plate fixation . augmentation with dbm yielded a 97% healing rate with no donor site morbidity , while 44% of patients augmented with autologous icbg had donor - site morbidity . similarly , gardner et al . healed 30/31 ( 97% ) distal femoral nonunions in which 30% were treated with dbm . in a multicenter randomized controlled trial of tibial nonunions treated with intramedullary ( i m ) nailing and either autologous icbg or op-1 ( bmp-7 ) implanted in a bovine collagen carrier ( dbm ) , dbm demonstrated statistically equivalent clinical and radiographic healing rates at nine months and two years ( 81% vs 85% ) . when treating 47 clavicular nonunions , endrizzi et al . utilized dbm alone in 29.8% of patients , drill reamings in 63.8% , and icbg in 6.4% to yield a 93% rate of union . despite their usage of dbm in nearly a third of their patients , their reoperation rate only approximated 7% . however , they did not differentiate between healing rates for those with dbm vs local grafting . variation in each company 's bone supply and mode of preparation yields varying qualities of dbm . for instance , peterson et al . found that grafton putty yielded the most fusion material at eight weeks in athymic rats when comparing three brands of dbm . morone and boden demonstrated that decreased autograft volume could be supplemented with dbm gel to yield fusion rates similar to those following use of autograft alone . overall , as many different allograft sources are available , at this point , the best source is yet to be determined . multiple factors influence the surgeons choice and can not be explored in depth in this paper . our study demonstrated an 84% clinical healing rate with an overall complication rate of 26% . although the authors recognize that the clinical success rate was 84% , the three individuals without radiographic evidence of healing can not be considered truly  healed  as the goal of using biologic enhancement is to obtain bony healing . thus , our radiographic healing rate of 68% is certainly not equivalent to the reported healing rates in the literature for autograft , which range from 89 to 100% . although the complication rate is slightly higher than those in the studies using orif with icbg , those reported rates mostly focused on graft - site morbidity  not the complications regarding the surgical procedure itself . two of our complications were minor and involved painful hardware that was removed . however , three of the complications were persistent nonunions , two of which failed catastrophically . thirty - seven percent of the patients in this study were smokers and in particular , the three patients with persistent nonunions each smoked at least one pack of cigarettes daily . although it did not reach statistical significance ( p=0.08 ) , the numbers do suggest that a trend may be present and perhaps a smoking history should be the reason for pause when using allograft bone substitute . this trend is supported by ziran et al . who noted healing rates of 67.9% and 87.5% in smokers and nonsmokers receiving allograft for fractures and nonunions , respectively . likewise , endrizzi et al . noted that their only reoperations were on smoking patients ( n=3 ) . we did exclude these patients from our study and did not review their charts further ( the incorporation of an autogenous graft with structural integrity in this instance theoretically appears superior and is supported in the literature ) . ballmer et al . had 100% union rate at six months in patients receiving tricortical icbg for segmental clavicular defects greater than or equal to 15  mm . additionally , endrizzi et al . also refrained from dbm in segmental defects , however , they did not specify what size of defect would lead them to icbg . two issues arose when examining the graft sources chosen to augment plate fixation in this study . although dbm was the primary graft source ( 68% ) , allograft corticocancellous bone chips ( 37% ) supplemented with rh - bmp ( 5% ) and calcium phosphate ( 5% ) were also included . this study 's intention was not to isolate a particular substance to prove similar efficacy to icbg . rather , it was to present a series of patients supplemented with a nonautogenous graft source rather than icbg and demonstrate its efficacy at healing clavicle nonunions . admittedly , this is a limitation of the study . however , this is not a commonly seen operative problem , and the graft sources of the treating surgeons did change throughout the years of retrospective data collection . in addition to the heterogeneity in graft choice , we incorporated prp at the nonunion site in 12 ( 63% ) of patients to augment healing . sanchez et al . reported healing of all femoral nonunions ( n=15 ) with injection of prp in conjunction with allograft , despite two requiring repeated percutaneous injections . likewise , han et al . found significant increases in dbm osteoinductivity with prp when not activated by thrombin . however , another study by mariconda et al . demonstrated no improvements in union rates or time to union when prp was injected into atrophic tibial , humeral , or forearm nonunions . showed no difference in bone formation for periodontal bone defects treated with either prp or prp and allograft . however , our results demonstrate that allograft bone substitute , in a variety of forms , has the potential to facilitate healing in a clavicular nonunion , in particular , in a non - smoker . although this study is the first to look only at clavicular nonunions treated with orif and bone graft substitute , it does have several limitations . it is a retrospective case series without randomization to a treatment group , and as stated above , has a lack of standardization to treatment when utilizing allograft source choices . eighteen of the fractures were fixed with a locking clavicle plate ; however , one was treated with a pelvic recon plate . one fracture was more medial and is susceptible to different forces across the fracture site and thus perhaps a different union potential , but it was rigidly fixed with a locking plate . however , our goal was to look at all clavicle nonunions to evaluate the efficacy of allograft as an alternative and successful treatment option when compared with icbg . however , we do recognize that our healing rates are inferior to the reported healing rates for the use of allograft . lastly , follow - up was not optimally standardized with functional assessments or complete radiographic profiles to ensure healing as several patients ceased to follow - up once they had obtained clinical evidence of healing . despite these limitations , this is the only series found in the literature evaluating clavicle nonunion healing rates grafted exclusively with allograft bone substitute sources . based on our current results , orif with a bone graft substitute source is a viable alternative to icbg when treating clavicle nonunions . our healing rates with allograft are lower than reported rates utilizing icbg , but our method does eliminate graft - site morbidity . however , smokers may have a higher risk for failure with allograft , although this was not found to be statistically significant . when clavicle nonunions persist after surgical treatment , the failures can be catastrophic and difficult to revise . thus , given this trend , orif and icbg may better serve patients with a smoking history . we are currently enrolling patients in a prospective case series to re - examine the efficacy of orif with dbm in clavicular nonunions to standardize treatment and to formally evaluate patient 's clinical progress with standardized outcomes measurements and complete radiographic analysis .
background : biologic augmentation with allograft has shown equivalent healing rates to autograft in several nonunion models . no literature exists clearly demonstrating this in the clavicle . 
 the purpose of this study was to evaluate the healing and complication rates of clavicle nonunions treated solely with open reduction and internal fixation ( orif ) and allograft.materials and methods : nineteen clavicle nonunions treated with orif and allograft were evaluated retrospectively to assess healing rates and complications based on clinical symptoms and radiographic findings.results:for the 19 patients included and treated with orif and allograft , clinical follow - up averaged 15 months . 
 seven patients were smokers . although complete radiographic healing was achieved in only 68% of patients , clinical success occurred in 16 ( 84% ) patients who demonstrated full range of motion and strength without pain . 
 the three patients who did not demonstrate full radiographic healing were completely pain free . 
 five patients experienced complications ( 26% ) . two underwent hardware removal due to persistent irritation after union . 
 three had a persistent painful nonunion . 
 each of these three patients was a smoker ( p=0.08 ) . 
 two proceeded to union after revision fixation . 
 the other had hardware failure , which was removed , with a persistent nonunion and did not wish any further treatment.conclusion:orif with allograft bone substitute is an acceptable treatment alternative to iliac crest bone graft for clavicle nonunions . 
 however , we did not demonstrate equivalent healing rates to published results utilizing autograft . 
 smokers were identified to have a trend toward higher failure rates with orif augmented with allograft and therefore these patients may be better served by augmenting fixation with autograft.level of evidence : iv ; retrospective comparative study .