the advent of effective chemotherapy has made limb salvage an oncologically safe option for a large majority of bone tumors without compromising long term survival .
the femur is the commonest site for primary bone tumors , and rarely , the extent of tumor may necessitate resection of the complete femur to achieve adequate oncologic clearance .
options include total femoral prostheses ( tfp ) , allografts , and rotationplasty.16 few reports in literature address the use of tfp exclusively for bone sarcomas .
most of these describe the functional results with expensive internationally available prostheses.25 in a resource challenged population , the cost of prostheses can occasionally be a limiting factor to limb salvage , especially in cases of malignant tumors where the prognosis is guarded.7 we present our experience with indigenously manufactured low cost total femoral prosthesis ( tfp ) for oncologic outcomes and implant survival after resection and replacement of the total femur .
nine patients were operated between december 2003 and june 2009 for resection and tfp implantation .
endoprosthetic reconstruction after resection was achieved with a modular total femur prosthesis using an indigenously manufactured fixed hinge tfp ( tmh - nice / restor , sushrut - adler mediequip pvt . ltd . ,
devrukh , india  www.sushrut.com/restor.htm ) in eight cases and an expandable howmedica modular resection system ( hmrs ) prosthesis in one case .
the eight cases in which the indigenously manufactured tfp was implanted were analyzed in this case series .
there were four males and four females with a mean age of 32 years ( range 1372 years ) .
all except one were done as a limb salvage procedure for a primary or recurrent malignant bone tumor .
case 7 was for revision of a broken proximal femur replacement , originally done for a malignant bone tumor [ table 1 ] .
the diagnosis included osteogenic sarcoma ( n=5 ) , ewing 's sarcoma ( n=1 ) , and chondrosarcoma ( n=2 ) .
the primary goal of surgery was limb preservation with complete excision of the tumor while retaining adequate muscle for satisfactory residual function .
surgery involved disarticulation of the hip and knee with enbloc excision of the entire femur and surrounding muscles involved with the tumor while preserving the neurovascular bundle .
the indigenously manufactured modular total femur system comprises a trochanteric component , a central resection segment , and a distal femoral component , designed to lock into each other with a customized self - locking taper .
the central resection segments are available in various sizes to match the length of the patient 's femur .
restoration of length was based on preoperative radiological assessment and reconfirmed intraoperatively by measurement of the resected specimen [ figure 1 ] .
( a ) preoperative t1-weighted mri showing involvement of the entire femur in a case of ewing 's sarcoma .
( c ) radiograph demonstrating restoration of limb length after total femur prosthesis to further reinforce hip stability and prevent dislocation , the residual hip capsule was sutured around the neck of the prosthesis . in cases where the capsule was deficient ,
it was reinforced with a polypropylene mesh ( prolene  johnson and johnson , ethicon division , aurangabad , india ) that was anchored to the acetabulum and extended to form a sleeve around the proximal part of the prosthesis.8 only glutei were either sutured directly to the prosthesis and/or sutured to the polypropylene mesh .
progressive mobilization using a walker or crutches was started within the first few postoperative days and patients gradually progressed to ambulation without the use of supports .
patients were instructed to restrict hip flexion to 60 for the first 6 weeks while encouraging active quadriceps exercises to regain knee extension .
patients were asked to followup every 3 months for the first 2 years and six monthly subsequently .
functional status was assessed at the time of last followup using the musculoskeletal tumor society ( msts ) scoring system.9 this was based on the analysis of six factors ( pain , use of supports for ambulation , walking ability , functional activities , gait , and emotional acceptance ) .
for each of the six factors , values of 05 were assigned based on established criteria .
the result was expressed as a sum total with a maximum score of 30 and as a percentage of the expected normal function for the patient .
survival of the implant was analyzed with the starting point defined as the date of implantation of the endoprosthesis and the endpoint being removal ( whatever the cause ) .
patients were censored for statistical analysis ( observation stopped before the event occurred ) if removal had not occurred at the time the patient was last assessed .
the mean followup was 33 months ( 972 months ) for all patients ( n=8 ) and 40 months ( 2472 months ) in survivors ( n= 5 ) .
8 patients analysed , 1 lost to follow up , 2 dead , 5 alive and were available for followup .
there was one case of infection which developed after 7 months in a patient who had the tfp implanted after excision of a recurrence around an earlier distal femoral prosthesis .
repeated wound lavage failed to control the infection and a hip disarticulation was finally performed ( case 1 ) .
it occurred in a 72-year - old male who had a large open biopsy elsewhere .
his biopsy diagnosis was chondrosarcoma which was revised to chondroblastic osteosarcoma after evaluation of the excised femur .
another patient ( case 1 ) who had the tfp implanted after excision of a recurrence around an earlier distal femoral prosthesis eventually succumbed to distant metastasis .
thus , five of the seven patients available for follow up are currently alive . the msts score for patients evaluated at their last followup ranged from 21 to 25 with a mean of 24 ( 80% ) .
all the patients were independent ambulators and none of them required a support for walking .
there was one case of infection which developed after 7 months in a patient who had the tfp implanted after excision of a recurrence around an earlier distal femoral prosthesis .
repeated wound lavage failed to control the infection and a hip disarticulation was finally performed ( case 1 ) .
it occurred in a 72-year - old male who had a large open biopsy elsewhere .
his biopsy diagnosis was chondrosarcoma which was revised to chondroblastic osteosarcoma after evaluation of the excised femur .
another patient ( case 1 ) who had the tfp implanted after excision of a recurrence around an earlier distal femoral prosthesis eventually succumbed to distant metastasis .
the msts score for patients evaluated at their last followup ranged from 21 to 25 with a mean of 24 ( 80% ) .
all the patients were independent ambulators and none of them required a support for walking .
reconstructing large defects after resection of a tumor has always been challenging . in the past , most patients with extended sarcomas of the femur had an amputation with poor function.3 the advent of better imaging modalities , effective chemotherapy , better understanding of anatomy with continuous refinement in surgical techniques , and advances in prosthesis design and materials have all played a part in increasing the incidence of limb salvage surgery .
limb salvage should not compromise patient survival while ensuring that patients are able to resume near - normal function as soon as possible.5 the prostheses used must also demonstrate good long term survival . when evaluating a reconstruction technique ,
various factors need to be considered including its complications , functional outcome , and durability . in resource - challenged populations ,
cost too often plays a role in the decision making.10 in most cases of tumors involving the femur , adequate resection may be possible with retention of enough bone either proximally or distally to seat an intramedullary stem for a distal femoral or proximal femoral prosthesis . occasionally , for oncologic reasons , entire femoral resection may be necessary or the residual bone stump after proximal / distal femoral resection may be too short to adequately seat a stable intramedullary stem .
hip dislocation is a common complication reported after total femur replacement.24611 a combination of various factors can contribute to this .
these include lack of functional abductor musculature , resection of the joint capsule , acetabular resurfacing , and use of a rotating hinge design at the knee since rotation at the knee can lead to hip dislocation.25 in our series , we did not have any dislocation .
this can be attributed to the use of a fixed hinge prosthesis , using a bipolar head in all cases , and reinforcing the residual hip capsule with a polypropylene mesh in cases where the capsule was deficient .
the incidence of local recurrence is a reflection of adequate oncologic clearance and the effectiveness of chemotherapy.12 we had one local recurrence occurring in a case of osteosarcoma , who had an open biopsy at a non oncology center and received no chemotherapy . having identified definite adverse contributing factors in this case ,
we believe that limb salvage with a tfp is an oncologically sound procedure in appropriately selected cases .
local control rates are similar to those described for limb salvage procedures at other sites.7 the survival of the implant was 88% , with removal as the endpoint .
the average functional score ( 80% ) in our study as evaluated by the msts scoring system is encouraging when compared with other series describing the use of tfp [ table 2].246 one case ( case 8) currently has 3 cm shortening and is managing with a shoe raise .
patients reported very good psychological acceptance after limb salvage with the tfp despite having a poor gait which is primarily due to the lack of good abductor muscle attachment .
this is significant as the prostheses used for limb salvage were low - cost , locally manufactured devices costing approximately us $ 2000 ( international prosthesis costs approximately us $ 18,000 ) .
thus , due to cost constraints , we are unable to offer conventional limb salvage to some young children requiring total femur excision and do a rotationplasty instead.13 our study is limited by its small numbers , but the uncommon use of tfp for bone sarcomas would necessitate results from various centers being pooled to reach meaningful conclusions.4 though late local recurrence is uncommon , the incidence of implant related complications can be expected to increase with a longer followup.12 in spite of these shortcomings , we believe that this study does add to the existing literature on use of massive implants in limb salvage , especially the use of tfp in appropriately indicated patients with malignant bone tumors .
the successful use of locally manufactured megaprostheses demonstrates that cost constraints need no longer be an insurmountable barrier for the use of limb salvage implants in resource - challenged populations .
 background : the extent of tumor may necessitate resection of the complete femur rarely to achieve adequate oncologic clearance in bone sarcomas . 
 we present our experience with reconstruction in such cases using an indigenously manufactured , low - cost , total femoral prosthesis ( tfp ) . 
 we assessed the complications of the procedure , the oncologic and functional outcomes , and implant survival.materials and methods : eight patients ( four males and four females ) with a mean age of 32 years , operated between december 2003 and june 2009 , had a tfp implanted . 
 the diagnosis included osteogenic sarcoma ( 5 ) , ewing 's sarcoma ( 1 ) , and chondrosarcoma ( 2 ) . 
 mean followup was 33 months ( 972 months ) for all and 40 months ( 2472 months ) in survivors . 
 they were evaluated by musculoskeletal tumor society score , implant survival as well as patient survival.results:there was one local recurrence and five of seven patients are currently alive at the time of last followup . the musculoskeletal tumor society score for patients ranged from 21 to 25 with a mean of 24 ( 80% ) . 
 the implant survival was 88% at 5 years with only one tfp needing removal because of infection.conclusions:a tfp in appropriately indicated patients with malignant bone tumors is oncologically safe . 
 a locally manufactured , cost - effective implant provided consistent and predictable results after excision of the total femur with good functional outcomes . 
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