Clinical and functional outcomes of patients with a pathologic fracture in high-grade osteosarcoma

BACKGROUND AND OBJECTIVES

There have been variable reports of outcomes of patients with osteosarcoma and pathologic fractures. The purpose of this study was to document outcomes after management of this clinical entity at a single large oncology center.

METHODS

A retrospective review was undertaken of our database between 1989 and 2006. We compared oncologic and functional outcomes of 201 patients with high-grade osteosarcoma without pathologic fractures to 31 patients with pathologic fractures.

RESULTS

The rate of amputation in the group with pathologic fracture was significantly higher than the group without fracture (39% vs. 14%, P = 0.001). There was no difference in the rate of local recurrence between groups. The 5-year survival was superior in the group without pathologic fracture (60% vs. 41%, P = 0.0015). For patients with localized disease, 5-year survival was higher in patients without fracture (68% vs. 52%, P = 0.006). Disability as measured by the Toronto Extremity Salvage Score was no different between the groups. Impairment as measured by the Musculoskeletal Tumor Society scores was lower in the group without fracture.

CONCLUSIONS

Presentation with a pathologic fracture in osteosarcoma did not preclude limb salvage surgery in a majority of patients, did not increase the risk of local recurrence, but was associated with poorer overall survival.

Radiosensitivity translates into excellent local control in extremity myxoid liposarcoma: a comparison with other soft tissue sarcomas

BACKGROUND

Myxoid liposarcoma has been reported to be more radiosensitive compared with other soft tissue sarcomas (STS). The authors report the results of multidisciplinary treatment of extremity myxoid liposarcoma compared with a contemporary cohort of other STS subtypes with an emphasis on the role of radiotherapy (RT) in improving local control.

METHODS

Between 1989 and 2004, 691 patients were identified from a prospective STS database who underwent combined management for localized extremity STS and were followed for a minimum of 12 months or until death. All patients underwent surgery together with pre or postoperative RT, depending on their presenting characteristics and resection margins. Demographics and outcomes were compared between patients with myxoid liposarcoma and other STS subtypes (other-STS).

RESULTS

Of 691 patients, 88 patients had myxoid liposarcoma and 603 had other STS subtypes (other-STS). Median age was 48 and 60 years for the myxoid liposarcoma and other-STS groups, respectively. Median follow-up was 86 and 61 months, respectively. For myxoid liposarcoma and other-STS groups, preoperative RT was used in 57% versus 61% of patients and postoperative RT in 43% versus 39%, respectively. The 5-year local recurrence-free survival was 97.7% for patients with myxoid liposarcoma compared with 89.6% for patients with other-STS tumors (P = .008). High-grade tumors were present in 7% and 59% of myxoid liposarcoma and other-STS patients, respectively (P = .0003). Two myxoid liposarcoma patients with local recurrence had positive resection margins, whereas only 33% of patients in the other-STS group who developed a local recurrence had positive resection margins. No patients with myxoid liposarcoma required amputation as primary management, whereas 8 (1.3%) required amputation as primary management in the other-STS group. Systemic disease control was superior in myxoid liposarcoma compared with other-STS patients, with 5-year overall and metastasis-free survival rates of 93.9% versus 76.4% (P = .0008) and 89.1% versus 66.0% (P = .0001) respectively. Of 12 myxoid liposarcoma patients with distant metastases, 7 appeared in nonpulmonary sites. In comparison, 205 (34%) patients with other-STS tumors developed systemic disease but 78% had pulmonary metastases.

CONCLUSIONS

Multidisciplinary management of extremity STS achieves high rates of local control. Myxoid liposarcoma is associated with higher rates of local control compared with other STS subtypes, after combined surgery and radiation, suggesting a particular radiosensitivity that can be exploited to improve oncologic outcome in appropriate cases.

Bone fractures following external beam radiotherapy and limb-preservation surgery for lower extremity soft tissue sarcoma: relationship to irradiated bone length, volume, tumor location and dose

PURPOSE

To examine the relationship between tumor location, bone dose, and irradiated bone length on the development of radiation-induced fractures for lower extremity soft tissue sarcoma (LE-STS) patients treated with limb-sparing surgery and radiotherapy (RT).

METHODS AND MATERIALS

Of 691 LE-STS patients treated from 1989 to 2005, 31 patients developed radiation-induced fractures. Analysis was limited to 21 fracture patients (24 fractures) who were matched based on tumor size and location, age, beam arrangement, and mean total cumulative RT dose to a random sample of 53 nonfracture patients and compared for fracture risk factors. Mean dose to bone, RT field size (FS), maximum dose to a 2-cc volume of bone, and volume of bone irradiated to >or=40 Gy (V40) were compared. Fracture site dose was determined by comparing radiographic images and surgical reports to fracture location on the dose distribution.

RESULTS

For fracture patients, mean dose to bone was 45 +/- 8 Gy (mean dose at fracture site 59 +/- 7 Gy), mean FS was 37 +/- 8 cm, maximum dose was 64 +/- 7 Gy, and V40 was 76 +/- 17%, compared with 37 +/- 11 Gy, 32 +/- 9 cm, 59 +/- 8 Gy, and 64 +/- 22% for nonfracture patients. Differences in mean, maximum dose, and V40 were statistically significant (p = 0.01, p = 0.02, p = 0.01). Leg fractures were more common above the knee joint.

CONCLUSIONS

The risk of radiation-induced fracture appears to be reduced if V40 <64%. Fracture incidence was lower when the mean dose to bone was <37 Gy or maximum dose anywhere along the length of bone was <59 Gy. There was a trend toward lower mean FS for nonfracture patients.

Oncologic and functional outcome of scapular chondrosarcoma

BACKGROUND

The scapula is a common site for chondrosarcoma to occur. There has been disagreement between recent studies documenting the oncologic outcomes in patients with chondrosarcoma of the scapula. The purpose of this study was to investigate both the oncologic and functional outcomes of patients presenting to a large oncology center with primary chondrosarcoma of the scapula.

METHODS

A review of our prospectively collected database was carried out. All patients in the years 1989 to 2004 undergoing surgical resection of primary chondrosarcoma of the scapula were included. We documented patient demographics, whether the patient underwent partial or total scapulectomy, oncologic outcomes including local and systemic recurrence, and functional outcome using the Musculoskeletal Tumor Society (MSTS) 87, MSTS 93, and Toronto Extremity Salvage Score (TESS) rating systems.

RESULTS

Twenty-four patients (16 males, 8 females), with a mean age of 44 years (range 18-74 years), met the inclusion criteria. There were no local recurrences. Two patients died of metastatic disease at 23 and 103 months postoperatively. No other patients have developed systemic disease. Sixteen patients underwent partial scapulectomy while eight underwent total scapulectomy. Functional outcome was better in the group undergoing partial scapulectomy with significantly higher MSTS 87 (30.8 versus 16.6), MSTS 93 (89.6 versus 68.3), and TESS (92.6 versus 74.9) scores than the total scapulectomy group.

CONCLUSION

Patients with primary chondrosarcoma of the scapula have an excellent oncologic prognosis with a very low local recurrence and metastatic rate. Functional outcomes are better for patients undergoing partial rather than total scapulectomy.

Two-stage revision of infected uncemented lower extremity tumor endoprostheses

We reviewed our experience with 2-stage revision of uncemented Kotz Modular Femoral and Tibial Replacement System prostheses from 1989 to 2004. A total of 180 lower extremity tumor prostheses were inserted, 15 of which underwent removal of the prosthesis for infection. Eleven patients underwent subsequent second-stage revision, and 4 underwent amputation. Of the 11 patients who underwent revision, 8 continue to be free of infection an average of 33 months postoperatively. Of these 8 patients, 6 were revised without removal of the diaphyseal anchorage piece, which were all well ingrown. Most successful revisions were in the group that developed infection within 6 months of their original procedure. Two-stage revision of uncemented tumor endoprostheses with retention of a well-ingrown stem can be associated with successful eradication of infection.

Studies of the in vivo radiosensitivity of human skin fibroblasts

BACKGROUND AND PURPOSE

To examine the radiosensitivity of skin cells obtained directly from the irradiated skin of patients undergoing fractionated radiation treatment prior to surgery for treatment of soft tissue sarcoma (STS) and to determine if there was a relationship with the development of wound healing complications associated with the surgery post-radiotherapy.

METHODS

Micronucleus (MN) formation was measured in cells (primarily dermal fibroblasts) obtained from human skin at their first division after being removed from STS patients during post-radiotherapy surgery (2-9 weeks after the end of the radiotherapy). At the time of radiotherapy (planned tumor dose - 50Gy in 25 daily fractions) measurements were made of surface skin dose at predetermined marked sites. Skin from these sites was obtained at surgery and cell suspensions were prepared directly for the cytokinesis-blocked MN assay. Cultured strains of the fibroblasts were also established from skin nominally outside the edge of the radiation beam and DNA damage (MN formation) was examined following irradiation in vitro for comparison with the results from the in situ irradiations.

RESULTS

Extensive DNA damage (MN) was detectable in fibroblasts from human skin at extended periods after irradiation (2-9 weeks after the end of the 5-week fractionated radiotherapy). Analysis of skin receiving a range of doses demonstrated that the level of damage observed was dose dependent. There was no clear correlation between the level of damage observed after irradiation in situ and irradiation of cell strains in culture. Similarly, there was no correlation between the extent of MN formation following in situ irradiation and the propensity for the patient to develop wound healing complications post-surgery.

CONCLUSIONS

Despite the presence of DNA damage in dermal fibroblasts weeks after the end of the radiation treatment, there was no relationship between this damage and wound healing complications following surgery post-irradiation. These results suggest that factors other than the radiosensitivity of the skin fibroblasts likely also play a role in wound healing in deep wound sites associated with surgery for STS following radiation therapy.

Joint salvage for pathologic fracture of giant cell tumor of the lower extremity

Pathologic fracture through giant cell tumor is thought to be associated with higher rates of recurrence and poor functional outcome. We compared patients with and without pathologic fracture through giant cell tumor of weightbearing long bones. We retrospectively reviewed 139 patients with giant cell tumor of weightbearing long bones with (n = 43) and without (n = 96) pathologic fracture at presentation; the two groups had similar demographics. Joint salvage was successful in 84% of the fracture group and 96% of the nonfracture group. Five-year recurrence-free survival rates were comparable between the two groups (82.6% [95% confidence interval, 69.1-95.9%] in the fracture group and 77.9% [95% confidence interval, 67.7-88.1%] in the non-fracture group). There was a trend toward lower 5-year metastatic-free survival in the fracture group (94.7% [95% confidence interval, 87.3-100%]) than in the nonfracture group (97.3% [95% confidence interval, 93.5-100%]). Functional outcome was good and similar in the two groups. Arthrofibrosis was more common in the group with pathologic fracture. Joint salvage for patients with pathologic fractures through giant cell tumor of weightbearing bones is a reasonable option with functional outcomes and recurrence rates comparable to those of patients without fracture.

Does the method of treatment affect the outcome in soft-tissue sarcomas of the adductor compartment?

We have investigated the significance of the method of treatment on the oncological and functional outcomes and on the complications in 184 patients with soft-tissue sarcomas of the adductor compartment managed at three international centres. The overall survival at five years was 65% and was related to the grade at diagnosis and the size of the tumour. There was no difference in overall survival between the three centres. There was, however, a significant difference in local control with a rate of 28% in Centre 1 compared with 10% in Centre 2 and 5% in Centre 3. The overall mean functional score using the Toronto Extremity Salvage Score in 70 patients was 77% but was significantly worse in patients with wound complications or high-grade tumours. The scores were not affected by the timing of radiotherapy or the use of muscle flaps. This large series of soft-tissue sarcomas of the adductor compartment has shown that factors influencing survival do not vary across the international boundaries studied, but that methods of treatment affect complications, local recurrence and function.

Radiation planning comparison for superficial tissue avoidance in radiotherapy for soft tissue sarcoma of the lower extremity

PURPOSE

Three types of preoperative radiotherapy (RT) plans for extremity soft tissue sarcoma were compared to determine the amount of dose reduction possible to the planned surgical skin flaps required for tumor resection and wound closure, without compromising target coverage.

METHODS AND MATERIALS

Twenty-four untreated patients with large, deep, lower extremity STS treated with preoperative RT and limb salvage surgery had their original conventional treatment plans re-created. The same clinical target volume was used for all three plans. The future surgical skin flaps were created virtually through contouring by the treating surgeon and regarded as an organ at risk. The original, conformal, and intensity-modulated RT (IMRT) plans were created to deliver 50 Gy in 25 fractions to the clinical target volume. Clinical target volume and organ-at-risk dose-volume histograms were calculated and the plans compared for conformality, target coverage, and dose sparing.

RESULTS

The mean dose to the planned skin flaps was 42.62 Gy (range, 30.24-48.65 Gy) for the original plans compared with 40.12 Gy (range, 24.24-47.26 Gy) for the conformal plans and 26.71 Gy (range, 22.31-31.91 Gy) for the IMRT plans (p = 0.0008). An average of 86.4% (range, 53.2-97.4%) of the planned skin flaps received >or=30 Gy in the original plans compared with 83.4% (range, 36.2-96.2%) in the conformal plans and only 34.0% (range, 22.5-53.3%) in the IMRT plans (p = 0.0001). IMRT improved target conformality compared with the original and conformal plans (1.27, 2.34, and 1.76, respectively, p = 0.0001).

CONCLUSION

In a retrospective review, preoperative IMRT substantially lowered the dose to the future surgical skin flaps, sparing a greater percentage of this structure's volume without compromising target (tumor) coverage.

Aseptic loosening is uncommon with uncemented proximal tibia tumor prostheses

Aseptic loosening is a frequent cause of failure of cemented proximal tibia tumor endoprostheses. Uncemented prostheses may lessen this risk. We identified complications including aseptic loosening that affected prosthetic survival, limb survival and functional outcome for 44 consecutive patients after sarcoma resection from the proximal tibia and uncemented endoprosthetic reconstruction. At a mean final followup of 60 months (range, 9-152 months), there were no cases of aseptic loosening. Twelve (27%) patients suffered 14 complications leading to prosthetic failure due to infection (n = 7), stem fracture (n = 2), rotational instability (n = 1), vascular compromise (n = 2) and local tumor relapse (n = 2). However, limb salvage was successful in 37 of 44 (84%) patients. Functional assessment for 35 patients revealed a mean Toronto Extremity Salvage Score of 77/100 (range, 33-98) and Musculoskeletal Tumor Society 1987 and 1993 scores of 25/35 (range, 13-31) and 75/100 (range, 33-97), respectively. Mean knee joint flexion was 91 degrees (range, 0-110 degrees ) and knee extension lag was 6 degrees (range, 0-30 degrees ). Three patients with knee extensor complications had inferior functional outcomes. Aseptic loosening is uncommon with uncemented proximal tibia reconstruction, but decreasing other complications at this location remains challenging.

LEVEL OF EVIDENCE

Therapeutic study, level IV-1 (case series).

Multifocality and multifocal postradiation sarcomas

Hypothetically, any site in a radiation portal has potential for late malignant transformation. Secondary malignant neoplasms may occur after almost any index cancer has been treated with radiation and/or chemotherapy. The incidence of secondary malignant neoplasms, histopathology, time delay, radiation dose, cytotoxic agents, age and type of initial malignancy, and outcome all negatively impact cancer survivors. We highlight the new concept of multifocality, defined as greater than two noncontiguous second malignant neoplasms that develop in a prior radiation port. We identified 48 patients with postradiation sarcomas from three prospectively collected databases. Fifteen of these patients (31%) had evidence of multifocal postradiation sarcomas. Five of 10 women had multifocal postradiation sarcomas after breast-conserving surgery for carcinoma. The longer the time interval between the index cancer and post-radiation sarcoma, the greater the likelihood of multifocal malignant transformation occurring.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Bone invasion in extremity soft-tissue sarcoma

BACKGROUND

The purpose of the current study was to evaluate histologic bone invasion as a predictor of oncologic outcome in extremity soft-tissue sarcoma (STS) patients presenting to a specialty sarcoma center between 1986 and 2001.

METHODS

All patients who underwent surgery for extremity STS were identified from the prospective database at the study institution. Patient demographic features were compared using chi-square analyses or independent-sample Student t-tests. The disease outcomes were compared for those with and without bone invasion using Kaplan-Meier survival analysis and Cox modeling.

RESULTS

In a review of 874 patients with STS of the extremity, 48 patients (5.5%) had evidence of bone invasion. Patients with bone invasion presented with larger tumors that were more frequently deep in the extremity and more often had metastases at presentation. Patients with bone invasion had lower metastasis-free survival but bone invasion was not found to be an independent prognostic factor (P = .274) on Cox modeling. Bone invasion was found to be prognostic of overall survival on multivariate analysis (P < .0001).

CONCLUSIONS

In a small percentage of patients with STS, bone resection may be required to obtain an adequate surgical margin, thereby limiting the risk of local tumor recurrence. Histologic bone invasion portends a poorer prognosis in terms of overall survival.

Wound healing morbidity in STS patients treated with preoperative radiotherapy in relation to in vitro skin fibroblast radiosensitivity, proliferative capacity and TGF-β activity

BACKGROUND AND PURPOSE

In a recent study, we demonstrated that the ability of dermal fibroblasts, obtained from soft tissue sarcoma (STS) patients, to undergo initial division in vitro following radiation exposure correlated with the development of wound healing morbidity in the patients following their treatment with preoperative radiotherapy. Transforming growth factor beta (TGF-beta) is thought to play an important role in fibroblast proliferation and radiosensitivity both of which may impact on wound healing. Thus, in this study we examined the interrelationship between TGF-beta activity, radiosensitivity and proliferation of cultured fibroblasts and the wound healing response of STS patients after preoperative radiotherapy to provide a validation cohort for our previous study and to investigate mechanisms.

PATIENTS AND METHODS

Skin fibroblasts were established from skin biopsies of 46 STS patients. The treatment group consisted of 28 patients who received preoperative radiotherapy. Eighteen patients constituted a control group who were either irradiated postoperatively or did not receive radiation treatment. Fibroblast cultures were subjected to the colony forming and cytokinesis-blocked binucleation assays (low dose rate: approximately 0.02 Gy/min) and TGF-beta assays (high dose-rate: approximately 1.06 Gy/min) following gamma-irradiation. Fibroblast radiosensitivity and initial proliferative ability were represented by the surviving fraction at 2.4 Gy (SF(2.4)) and binucleation index (BNI), respectively. Active and total TGF-beta levels in fibroblast cultures were determined using a biological assay. Wound healing complication (WHC), defined as the requirement for further surgery or prolonged deep wound packing, was the clinical endpoint examined.

RESULTS

Of the 28 patients treated with preoperative radiotherapy, 8 (29%) had wound healing difficulties. Fibroblasts from patients who developed WHC showed a trend to retain a significantly higher initial proliferative ability after irradiation compared with those from individuals in the treatment group with normal wound healing, consistent with the results of our previous study. No link was observed between fibroblast radiosensitivity and WHC. Neither active nor total TGF-beta levels in cultures were significantly affected by irradiation. Fibroblast proliferation in unirradiated and irradiated cultures, as well as radiosensitivity, was not influenced by TGF-beta content. TGF-beta expression in fibroblast cultures did not reflect wound healing morbidity.

CONCLUSIONS

These data are consistent with our previous study and combined the results suggest that in vitro fibroblast proliferation after irradiation may be a useful predictor of wound healing morbidity in STS patients treated with preoperative radiotherapy. TGF-beta levels in culture do not predict WHC, suggesting that the role of TGF-beta in wound healing is likely controlled by other in vivo factors.

The surgical and functional outcome of limb-salvage surgery with vascular reconstruction for soft tissue sarcoma of the extremity

BACKGROUND

This study compared the surgical, oncological, and functional outcomes of patients undergoing limb-salvage surgery for extremity soft tissue sarcoma with vascular resection and reconstruction with the outcomes of those undergoing limb-salvage without vascular reconstruction.

METHODS

Nineteen patients were identified from a prospective soft-tissue sarcoma database who underwent vascular resection and reconstruction as part of their limb-salvage surgery and who were followed up for at least 1 year or until death. Each of these 19 patients was case-matched to 2 additional patients on the basis of tumor location, size, and depth; patient age; and timing of radiation. To compare functional outcome, a subset of patients was case-matched with additional criteria including wound-complication status, motor nerve sacrifice, similar preoperative function as determined by the Toronto Extremity Salvage Score, and no metastases at diagnosis or the 1-year follow-up.

RESULTS

Patients in the vascular reconstruction group were more likely to require a muscle transfer (53% vs. 18%; P = .008), experience a wound complication (68% vs. 32%; P = .03), experience deep venous thrombosis (26% vs. 0; P = .003), experience significant limb edema (87% vs. 20%; P = .001), and ultimately require an amputation (16% vs. 3%; P = .07). Patients who underwent vascular reconstruction had only slightly lower Toronto Extremity Salvage Score scores 1 year after surgery (78.5 vs. 84.2; P = .35). There were no significant differences in local or systemic tumor relapse between the two groups.

CONCLUSIONS

Vascular reconstruction is a feasible option in limb-salvage surgery for soft tissue sarcoma but is associated with an increased risk for postoperative complications, including amputation. Although function is not significantly worse after vascular reconstruction, the results are less predictable.

Outcome in two groups of patients with allograft-prosthetic reconstruction of pelvic tumor defects

To predict the outcomes obtained with allograft-implant composite reconstruction of pelvic defects after bone tumor resection better, a retrospective review of a prospectively collected database was done and two groups of patients were identified. These groups were compared with respect to oncologic and functional outcomes in this investigation. Group 1 included 21 patients with allograft total hip replacement reconstruction for pelvic bone tumors that required Type I and II or Type I, II, and III pelvic resections. Group 2 included five patients who required an acetabular allograft in combination with proximal femoral replacement for reconstruction of Type II pelvic resections done to treat proximal femoral bone sarcomas that invaded or surrounded the hip joint. Functional assessment was measured with three instruments (Toronto Extremity Salvage Score, Musculoskeletal Tumor Society 1987, and the Musculoskeletal Tumor Society 1993 scores). In Group 1, nine of 19 evaluable patients (two patients died in the immediate postoperative period) either retained the allograft until their death or were still alive at last followup with their allograft in place. An additional patient had revision surgery to an allograft-saddle composite that remains intact. The functional results in Group 1 were influenced heavily by the occurrence of deep infection. Nine of 19 evaluable patients developed infection, with seven patients requiring either removal of the graft (three patients) or hindquarter amputation (four patients). Two patients retained their infected allografts with long-term antibiotic suppression. In 10 Group 1 patients who did not develop infection, reasonable functional results were obtained. Group 2 patients had no infections and better functional results.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Epineural dissection is a safe technique that facilitates limb salvage surgery

Epineural dissection has been used in our center for the past 19 years as a means of preserving the sciatic nerve when it is closely applied to a soft tissue sarcoma. Our aim in doing this study was to establish if this technique resulted in increased local or systemic recurrence of the tumor. In addition, we assessed functional outcomes. Forty-three patients had an epineural dissection done during primary resection of a malignant thigh tumor. These patients were compared with 44 patients with tumors that were of similar size and grade but distant from the nerve. We also analyzed seven patients who required nerve resection. There was no difference in local or systemic recurrence rates or functional outcomes when epineural dissection was done. Those with nerve resection had worse Musculoskeletal Tumor Society scores but equivalent Toronto Extremity Salvage Scores to those with an epineural dissection. We conclude that epineural dissection (when combined with radiotherapy in a planned multidisciplinary approach to limb salvage) is both a safe and effective procedure to preserve the sciatic nerve and that nerve resection should be limited to situations where the nerve is completely encased in tumor.

LEVEL OF EVIDENCE

Prognostic study, Level II-2 (retrospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.

Iliosacral resection for primary bone tumors: is pelvic reconstruction necessary?

Iliosacral resection for primary bone tumors creates a large unstable pelvic ring defect, the treatment of which remains controversial. We did this study to determine if skeletal reconstruction of such defects is necessary. Sixteen patients whose data were collected prospectively had iliosacral resection with a minimum followup of 12 months. The surgical and functional results of patients who had skeletal reconstruction (n = 4) were compared with the results of patients who did not have iliosacral repair (n = 12) using a case-control design. Function was evaluated by assessing impairment using the Musculoskeletal Tumor Society 1987 and 1993 rating scales, and disability was measured using the Toronto Extremity Salvage Score. Although all four iliosacral arthrodeses initially healed, one allograft used for reconstruction fractured and another was removed because of progressive lumbosacral spinal instability. Patients treated without pelvic reconstruction had fewer operative complications. Although the Toronto Extremity Salvage Score and the Musculoskeletal Tumor Society 1987 and 1993 scores were similar for both patient groups, those patients who were treated without reconstruction were less likely to require the use of an ambulatory assistive device, less likely to require narcotics or have chronic pain, and more likely to return to work. These results suggest that reconstruction of the skeletal defect to restore pelvic stability after iliosacral resection is not mandatory.

LEVEL OF EVIDENCE

Therapeutic study, Level III-1 (case-control study). See the Guidelines for Authors for a complete description of levels of evidence.

Outcome after pelvic sarcoma resection reconstructed with saddle prosthesis

We retrospectively reviewed 27 patients who had saddle prosthetic reconstruction for pelvic sarcoma from 1991 to 2001 with a mean followup of 45 months. Functional outcome was assessed with Musculoskeletal Tumor Society Scores of 1987 and 1993 and the Toronto Extremity Salvage score. Survival, recurrences, and complications were recorded. Seven (26%) patients had Type II (periacetabular) pelvic resection and 20 had Types II and III (periacetabular and pubis) pelvic resection. Eleven patients had chemotherapy treatment. None received radiation therapy. At final followup 14 patients were free of disease, 11 patients died, and two patients were alive with disease. The survival rate was 60%. Twenty-two percent had local recurrence, and 22% had metastasis. The mean Musculoskeletal Tumor Society Score 93 score in 17 patients was 50.8% +/- 21.7%, the mean Musculoskeletal Tumor Society Score 87 score was 15.3 +/- 6.1, and the mean Toronto Extremity Salvage score was 64.4% +/- 17.2%. Infection occurred in 10 patients; six were deep infections. There were five nerve palsies. Heterotopic ossification occurred in 10 patients, fracture occurred in six patients, and dislocation occurred in six patients. Limb shortening was progressive until it stabilized at 12 months, and ultimately ranged between 1 and 6 cm. Five patients were retired, five had full-time employment, and six were disabled. Reconstruction with the saddle prosthesis after resection for pelvic sarcoma is associated with substantial morbidity. However, the functional results seem to confer an advantage when compared with the considerable disability incurred after hemipelvectomy.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series without control group). See the Guidelines for Authors for a complete description of levels of evidence.

Uncemented tumor endoprostheses at the knee: root causes of failure

Although cemented tumor endoprostheses are the most commonly used method for reconstruction of the distal femur or proximal tibia after resection of primary bone tumors, aseptic loosening remains a common complication. Uncemented tumor prostheses may minimize this problem. We investigated the root causes of prosthetic failure for 99 patients with a fixed-hinge, bone-ingrowth Kotz Modular Femur and Tibia Resection System endoprosthesis and compared complications that led to implant failure with results in the literature. Of the 74 distal femoral implants and 25 proximal tibial implants, 25 patients had complications that resulted in prosthetic failure (removal of the prosthesis) at a median of 24.1 (range, 0.8-72.6) months. Failure was caused by prosthesis (n = 18) or oncologic-related (n = 7) complications. However, limb-salvage was possible for 87 of 99 patients. Smaller stem size in the distal femur and longer bone resection length in the proximal tibia were significantly associated with increased risk of prosthetic failure by multivariate analysis. The risk of stem fracture (6 of 99 patients) and infection (10 of 99 patients) was higher than other reports, but aseptic loosening (2 of 99 patients) was uncommon. These results suggest that although the bone-ingrowth surface of this prosthesis leads to a very low aseptic loosening rate, the higher risk of stem fracture and infection must be addressed in future implant designs.

LEVEL OF EVIDENCE

Therapeutic study, level IV-1 (case series).

Periprosthetic bone remodeling around a prosthesis for distal femoral tumors: longitudinal follow-up

Serial measurements using dual-energy x-ray absorptiometry (DEXA) were undertaken to evaluate progressive periprosthetic bone loss in patients treated for primary bone tumors of the distal femur using an uncemented tumor prosthesis. Twelve patients underwent sequential DEXA analysis on average 26.5 and 90.9 months postsurgery. Changes in bone mineral density were measured in regions of interest (ROIs) around the prosthesis stem. The test-retest reliability coefficient (r) ranged from 0.92 to 0.99 for all ROI. In the most distal ROI (ROI1), 10 of 11 patients with 2 measurements showed no change or a small increase in absolute bone mineral density. The results in other ROIs were similar. This longitudinal DEXA data suggest that progressive bone resorption is not problematic with an uncemented distal femur endoprosthesis at intermediate follow-up. Key words: DEXA, stress shielding, uncemented endoprothesis, tumor, bone loss.

Fractures following radiotherapy and limb-salvage surgery for lower extremity soft-tissue sarcomas. A comparison of high-dose and low-dose radiotherapy

BACKGROUND

The purpose of the present retrospective study was to determine the correlation between radiation therapy and the risk of postradiation fracture following combined therapy for the treatment of soft-tissue sarcomas of the lower extremity.

METHODS

Three hundred and sixty-four patients with lower extremity sarcomas that had been treated with combined external beam radiation therapy and limb-salvage surgery were evaluated on the basis of a combined chart and data-base review. For the purposes of analysis, high-dose radiation was defined as 60 or 66 Gy and low-dose radiation was defined as 50 Gy. The timing of irradiation was defined as preoperative, postoperative, or preoperative followed by a postoperative boost. Univariate and multivariate analyses were used to determine which factors were associated with fracture risk.

RESULTS

Twenty-seven fractures occurred in twenty-three patients. Twenty-four fractures occurred in twenty patients who had been managed with high-dose radiation. Seventeen of these patients had received postoperative radiation (with fifteen patients receiving 66 Gy and two receiving 60 Gy), and three had received preoperative radiation with a postoperative boost (total dose, 66 Gy). Three fractures occurred in three patients who had received preoperative, low-dose radiation (50 Gy). Of the twenty-three patients who sustained a pathologic fracture, eighteen were female and five were male. The crude median time to fracture was forty-three months. Most fractures occurred in the femoral shaft (thirteen) or the femoral neck (eight). High-dose radiation was associated with a greater risk of fracture when compared with low-dose radiation (p = 0.007).

CONCLUSIONS

Women more than fifty-five years of age who are managed with removal of a thigh sarcoma combined with radiation therapy have a higher risk of pathologic fracture. The frequency of pathologic fractures associated with higher doses (60 or 66 Gy) of radiation is significantly higher than that associated with lower doses (50 Gy).