this is the first report of successful allograft mosaicplasty treatment of a large osteochondral lesion of the knee caused by a blast fragment sustained during combat operations .
an active - duty infantryman sustained an osteochondral lesion of the medial femoral condyle caused by a metallic fragment of an explosively formed projectile .
the patient continued to experience pain , mechanical symptoms , and repeated effusions after initial nonoperative treatment .
allograft mosaicplasty of the lesion utilizing two 18-mm - diameter fresh allograft osteochondral plugs was performed at 6 months post - injury .
at 2-year follow - up , the patient remains on active duty with marked improvement in symptoms .
two years postoperatively , his outcome scores are 72 of 100 on the western ontario and mcmaster university osteoarthritis scoring index ( womac ) and 60 of 100 on the knee injury and osteoarthritis outcome score ( koos ) .
his follow - up x - rays and mri demonstrate intact articular cartilage and subchondral bone incorporation .
while numerous cartilage restoration techniques have been used with success for the treatment of osteochondral injuries to the femoral condyles , no published reports describe the use of allograft mosaicplasty in this location for open , penetrating injuries with focal cartilage loss .
this is the first documented use of allograft mosaicplasty for a traumatic osteochondral defect of the medial femoral condyle caused by a metallic projectile .
we demonstrate a high level of functioning is possible following allograft mosaicplasty of a large osteochondral lesion caused by penetrating ballistic trauma .
penetrating injuries to the knee are encountered both in civilian trauma and during military combat operations . in the military , these injuries most frequently result from explosive blasts or bullets . aside from the soft tissue involvement
in addition to irrigation , debridement , and soft tissue repair , multiple other modalities may be required for successful treatment of these injuries .
mosaicplasty procedures have been employed to treat large , full - thickness loss of cartilage in multiple joints of the extremities . both autograft and allograft procedures have been described . while the majority of reports on osteochondral lesions of the knee describe trauma as the pathoetiology , none specifically describe the use of mosaicplasty for injuries caused by projectiles .
permission was obtained from the patient to allow publication of his treatment history and radiological images . on the evening of 30 october 2006 , a 34-year - old male u.s .
army infantry officer sustained multiple injuries after his armored troop transporter was struck by an explosively formed projectile ( efp ) while on patrol with his unit just outside of baghdad , iraq .
efps are a particularly lethal form of armor - penetrating improvised explosive device ( ied ) that have been employed by insurgent forces in iraq .
following the attack , the patient was unable to ambulate because of pain in his right leg and knee .
the patient was evacuated to the 28th combat support hospital in baghdad , where a full trauma work - up was performed .
were noted to include penetrating wounds to his lower extremities , scrotum , and perineum .
the largest of the penetrating wounds was a 2-cm laceration just medial to the inferior pole of his left patella .
radiographs revealed an irregular radiodense piece of fragmentation in the anterior soft tissues of the knee ( fig .
1 ) . because it was unclear from the imaging whether the fragment had breached the joint capsule , a 50-ml sterile saline challenge to the knee joint was performed .
an open knee injury was diagnosed after injected saline was noted to be draining through the inferomedial knee wound .
the patient consented for irrigation and debridement of the left knee as well as surgical treatment of his genital injuries .
initial anteroposterior ( a ) and lateral ( b ) fluoroscopic images of the knee with retained metallic fragment . in the operating room , a limited medial parapatellar arthrotomy was performed by extending the traumatic wound . upon exploring the wound ,
this defect was extended to reveal a 3  2-cm area of full - thickness cartilage loss from the lateral portion of the medial condyle .
in addition to the cartilage loss , a portion of the corresponding subchondral bone was noted to be denuded .
the joint was further explored through the wound and irrigated with 9 l of sterile saline .
no loose bone , cartilage , or additional foreign material resembling the area of osteochondral loss was found in the joint or soft tissues .
the remainder of his lower extremity wounds were irrigated and debrided followed by open management .
he underwent left orchiectomy for irreparable testicular damage , and his remaining perineal wounds were debrided and treated with open management . the patient was subsequently evacuated back to the authors medical facility within 10 days .
initially , following healing of the soft tissues , the patient was treated with active range of motion of his injured knee and protected , partial weightbearing for 8 weeks . during this initial rehabilitation period ,
the patient complained of significant pain , repeated effusions , and mechanical symptoms , making weightbearing very difficult without the aid of crutches .
he received additional imaging , including a computed tomography ( ct ) scan ( fig .
3 ) , which revealed a 3.2  1.9-cm lesion on the medial condyle . a discussion of possible treatment options was undertaken , and the patient opted to undergo allograft mosaicplasty of the lesion . once an allograft condyle became available , the patient was taken to the operating room for arthroscopy followed by allograft mosaicplasty of the lesion at 6 months postinjury .
sagittal computed tomography ( ct ) image showing the medial femoral condylar traumatic defect 4 months after injury .
intraoperatively , the patient s knee was ligamentously stable , and arthroscopic evaluation confirmed the dimensions of the lesion . a small horizontal cleavage tear of the medial meniscus was discovered and debrided .
following arthroscopy , a 10-cm medial parapatellar arthrotomy was performed , allowing access to the condylar lesion ( fig .
4 ) . a decision to utilize two 18-mm - diameter allograft osteochondral plugs was made .
the donor plugs were obtained from a size - matched , fresh allograft femoral condyle ( allosource , centennial , co ) using a commercially available harvesting system .
these plugs were implanted into the area of the lesion after the diseased tissue had been removed using complementary sized drill bits ( fig .
after surgery , the patient remained nonweightbearing on the operative leg for 3 months but was allowed unrestricted range of motion .
although released to full activity , he remains limited in running and marching with full combat gear ( approximately 80 lb of protective gear and equipment ) .
two years postoperatively , his outcome scores are the following : western ontario and mcmaster university osteoarthritis scoring index ( womac ) , 72 of 100 ; and knee injury and osteoarthritis outcome score ( koos ) , 60 of 100 .
his follow - up x - rays and mri demonstrate intact articular cartilage and subchondral bone incorporation ( fig .
sagittal fat - suppressed magnetic resonance image of the knee 2 years following allograft mosaicplasty .
penetrating injuries to joints , particularly knees , are commonplace in the battlefield environment . in one series , knee trauma accounted for 50% of joint injuries .
although less common than those caused by blunt trauma , penetrating articular injuries occur in noncombat - related incidents . in the noncombat environment , these frequently arise from gunshot wounds .
unfortunately , many of these injuries have large amounts of comminution , affecting limb stability and greatly complicating reconstructive efforts .
although substantially less common , we do not know the incidence of focal , nondestabilizing osteochondral lesions resulting from blast injury in the global war on terror . several case series report generally 
good  outcomes in patients treated for penetrating ballistic injuries without defined follow - up periods or objective outcome measurements .
these patients were treated with arthroscopic debridement of foreign and loose bodies without further procedures . regarding focal cartilage lesions , only
 drilling  of these defects has been described outside of a single report of allograft reconstruction for extensive bone loss of the medial femoral condyle following a gunshot wound to the knee .
while numerous cartilage restoration techniques have been used with success for the treatment of osteochondral injuries to the femoral condyles , no published reports describe the use of allograft mosaicplasty in this location for open , penetrating injuries with focal cartilage loss . to the best of our knowledge ,
this is the first documentation of allograft mosaicplasty used for reconstruction of a traumatic osteochondral defect of the medial femoral condyle caused by a metallic projectile .
although the use of allograft mosaicplasty was successful in our patient , it is not appropriate for all patients with focal osteochondral lesions of the femoral condyles caused by penetrating trauma .
some patients may sustain osteochondral injuries that are large and amenable to reduction and fixation , while small articular lesions ( less than 0.5 - 1.0 cm , depending on location ) may be treated with debridement , microfracture , or abrasion chondroplasty . for small articular cartilage lesions , it is prudent to first attempt less invasive methods such as arthroscopically assisted marrow stimulation techniques .
larger lesions ( measuring greater than 2.0 - 3.0 cm in area ) , such as the one encountered in our patient , have been treated successfully with a variety of methods including autologous chondrocyte implantation ( aci ) as well as both autograft and allograft mosaicplasty .
given the size of this patient s lesion and the involvement of the subchondral bone , we felt the best treatment was allograft mosaicplasty .
treatment of articular cartilage lesions is clearly dependent on several variables including patient factors , available resources , and surgeon capabilities .
all factors must be taken into consideration when planning treatment . with the high percentage of penetrating knee injuries resulting in articular cartilage injury ,
it is important to both accurately diagnose the lesions and choose a proper method of articular resurfacing .
this case report describes successful management of a large osteochondral injury to the medial femoral condyle using allograft mosaicplasty in an active - duty serviceman .
we demonstrate the utility of this technique for military as well as civilian orthopedic surgeons faced with similar scenarios .
 objective : this is the first report of successful allograft mosaicplasty treatment of a large osteochondral lesion of the knee caused by a blast fragment sustained during combat operations . the patient was able to return to active duty following rehabilitation.methods:an active - duty infantryman sustained an osteochondral lesion of the medial femoral condyle caused by a metallic fragment of an explosively formed projectile . 
 initial treatment consisted of removal of the foreign body and primary closure . 
 the patient continued to experience pain , mechanical symptoms , and repeated effusions after initial nonoperative treatment . 
 allograft mosaicplasty of the lesion utilizing two 18-mm - diameter fresh allograft osteochondral plugs was performed at 6 months post-injury.results:at 2-year follow - up , the patient remains on active duty with marked improvement in symptoms . 
 two years postoperatively , his outcome scores are 72 of 100 on the western ontario and mcmaster university osteoarthritis scoring index ( womac ) and 60 of 100 on the knee injury and osteoarthritis outcome score ( koos ) . 
 his follow - up x - rays and mri demonstrate intact articular cartilage and subchondral bone incorporation.conclusion:penetrating injuries to joints are commonplace in the battlefield environment . 
 combat injuries to the knee are frequently associated with articular cartilage injury . 
 while numerous cartilage restoration techniques have been used with success for the treatment of osteochondral injuries to the femoral condyles , no published reports describe the use of allograft mosaicplasty in this location for open , penetrating injuries with focal cartilage loss . 
 this is the first documented use of allograft mosaicplasty for a traumatic osteochondral defect of the medial femoral condyle caused by a metallic projectile . 
 the patient was able to return to active duty following rehabilitation . 
 we demonstrate a high level of functioning is possible following allograft mosaicplasty of a large osteochondral lesion caused by penetrating ballistic trauma . 
Objective:
Methods:
Results:
Conclusion:
Introduction
Case Report
Discussion