Wide excision of the lesion is the standard treatment in the treatment of malignant bone tumors. Various reconstruction methods after bone tumors excision have been developed, including megaprosthesis, allografting, and tumor-bearing bone grafts (irradiated bone, pasteurized bone, and frozen bone). With the collaboration of multidisciplinary team, the life expectancy has been increased significantly in the malignant tumor patients. Due to biological reconstructions can achieve acceptable long-term functional outcome, biological reconstructions have received increasing attention.
Tumor-bearing bone graft is one of biological reconstructions. In the past 20 years, tumor-bearing autografts frozen with liquid nitrogen have been reported as safe and effective for treating osteoblast tumors of various types and locations in basic experimental studies and clinical practices[8, 10-14]. The benefits include a shorter union period, restoration of bone stock, lower cost, osteoinduction, osteoconduction, perfect fit, ease of soft-tissue attachment, activation of antitumor immune response and decreased disease transmission[8, 11]. In fact, FAPC by pedicle method has the significant advantage in proximal femoral tumors. First, it is unnecessary to perform a femoral osteotomy and wait for the junction healing. Second, the ligaments and soft tissue around the proximal femur were easy to reattach original anatomic site and increased hip joint stability. Third, it can potentially preserve maximal bone matrix to avoid limiting retreatment options due to insufficient bone mass. This technique achieves early limb stability while recovery time and immediately promoting activity. In theory, all biological reconstructions have similar advantages and disadvantage. However, due to the loss of osteoinductive and osteogenic properties after thermal or radiation treatment, the allograft might have potential risk factors that lead to further surgery, such as nonunion with the host bone, graft fracture, bone resorption, hip abductor avulsion, and immunological reactions [5-7]. Takata et al. also reported that tumor-bearing frozen bones maintains their microstructure and osteoinductive ability compared to pasteurization, autoclaving and allograft [10].
Biomechanical stability is of great concern to biological reconstructions. Lee et al. reported that the pasteurization decreases the biologic and mechanical properties and reduces strength to less than that of an allograft[15]. Interestingly, Yamamoto et al. had reported that the frozen bone has sufficient biomechanical strength for limb reconstruction that is comparable to pasteurized autografts and allografts[12].
Previous studies reported that an APC 5-year survival and satisfactory MSTS score rates of 72–90% and 77–90%, respectively. APC is a better reconstruction option if easily available. Remarkably, graft–host junction union is a major problem, and the nonunion rate is reportedly 5%–19%[5, 6, 16-18]. On the other hand, Eid et al.[19] reported on using the pasteurized APC in 18 patients and had outcomes of MSTS functional score was 80%, 5- and 10-year graft survival rates of 86%, mean graft-host junction union time of 13 months, and 1 case of non-union. Chen et al.[20] also reported use of extracorporeal irradiated APC with an MSTS score of 72%, mean graft-host junction union time of 20 months, and 5-year graft survival rate of 85%. It seems that all biological reconstruction methods feature acceptable functional outcomes and implant survival rates. A few cases of nonunion or delayed union have been reported, although many studies reported that using the step-cut osteotomy, autogenous or allogenous bone graft into host bone, and non-cemented prostheses increased graft-host junction healing and stability in all biological reconstructions[5, 18, 21] (Table 2).
Greater trochanter stability in biological reconstruction is also a concern. Abductors reconstruction methods are controversial, including tendon to soft tissue, tendon to tendon, tendon to bone and bone to bone. However, complications include greater trochanter nonunion, trochanteric fracture, hip abductors avulsion, and resorption, which lead to poor function and a protracted postoperative rehabilitation period[18, 19].
Megaprosthesis has satisfactory short- to medium-term outcome, early mobilization and weight-bearing, and short operative time; however, abductor muscles reattachment is a problem of great concern; many reports have shown that using an artificial ligament to affix the megaprosthesis can promote soft-tissue reconstruction and achieve better joint stability and functional outcomes[22]. In fact, artificial ligament use is probably unable to reduce the occurrence of prosthetic complications such as aseptic loosening, prosthesis breakage, infection, and stress shielding[23]. In addition, long-term prosthetic failure rates are 6–33%, mean MSTS scores were 63–83%, and the major complications were infection (5–13%) and dislocation (0–20%) [4, 17, 23-25] (Table 2). Likewise, the studies reported that using silver– or iodine– coated implants can reduce overall infection rates[26, 27]. As mentioned above, many useful products or methods can prevent further complications; however, a higher cost burden, unavailability in some countries and the limited bone mass complicate revision surgeries.
In the current study, the functional outcome was similar to those of other methods of reconstruction. The mean MSTS functional score was 88%, and the 5- and 10-year graft survival rates were 100% and 50%, respectively. At the last follow-up, no prosthesis loosening or obvious lucent shadows around the autograft bone on radiological examination was seen, nor was hip abductors avulsion, abductor muscle weakness, or biomechanical changes caused by the freezing process. Only 1 patient had local recurrence around the residual soft tissue for which hip disarticulation was performed after 2 re-excisions. Wear of the acetabulum occurred in 2 patients despite the use of bipolar hemiarthroplasty, but this might be an inevitable long-term complication of joint replacement.
We prefer to use antibiotic-loaded cement and long-stem prostheses to reduce fracture and infection rates and provide immediate stability. More importantly than all of that, no femoral osteotomy accelerate rehabilitation by enabling full weight-bearing soon after the operation. This technique features desirable outcomes and provide biomechanical stability that is comparable to those of other methods of biological reconstruction or megaprosthesis.
The various reconstructive alternatives have acceptable oncological and functional outcomes. However, each method has its drawbacks, and choosing the method that maximizes the benefits for patients is a major concern. Surgeons must carefully consider the patient’s age, general condition, response to chemotherapy, and expectations when individualizing a treatment plan.
This study had several limitations. First, due to its retrospective design and single center, a relatively small number of patients were enrolled, a follow-up >10 years was available for only 4 of the 19 patients. Second, no control group was available for comparison of functional outcomes; thus, our results could be compared to only those of prior studies. Similarly, the accuracy of our results was lower than those of randomized study. Third, the patients had various diagnoses and were treated with various chemotherapy regimens, which might have affected survival rates and functional outcomes. Therefore, to assess the efficacy and safety of this procedure, a prospective study will compare the functional outcomes and survival rates of several reconstruction methods over a long-term follow-up period.