Bilateral Endoprosthetic Replacements of the Proximal Femur

Patient. We report the case of a 20-year-old caucasian male with an Ewing's sarcoma in the left upper femur. After induction chemotherapy, he underwent resection of the left upper femur and insertion of a cemented proximal femoral replacement. Four years later, he presented with a solitary bone metastasis in the right upper femur. He underwent further chemotherapy followed by resection and endoprosthetic replacement of the other proximal femur. He remains disease free with excellent function almost a year after the second operation. Discussion. We believe this is the first reported case of bilateral proximal femoral endoprostheses.


Introduction
Lim b-salva ge surgery is now possible in 85% of patients with prim ary sarcom as of bone. Re® nem ents in surgical techniques and chemotherapy regim es also m ean that patients are living longer and hence the effectiveness of the limb-salvage surgery and its durability is also becom ing increasingly im portant. 1± 5 As patients survive longer, unusual patterns of m etastatic disease are appearing and these present their own problem s in treatm entÐ both surgically and oncologically. W e report a case of Ewing' s sarcom a in w hich a solitary bone m etastasis developed in the contra-lateral proximal fem ur 4 1 2 years after endoprosthetic replacement and chem otherapy for Ewing' s sarcom a of the left proxim al fem ur. It was treated with a second proximal fem oral endoprosthesis. W e believe this is the ® rst reported case of bilateral proxim al femoral endoprosthetic replacem ents for prim ary bone tum our.

C ase history
A 20-year-o ld white C aucasian m ale was referred to us in July 1991 with a 25-w eek history of pain in the left upper fem ur. Radiograph ic im aging and biopsy con® rm ed Ewing' s sarcom a with extensive soft tissue disease (Figs 1 and 2). H e received induction chem otherapy with IVAD (ifosfam ide, vincristine, adriam ycin, actinomycin D) and after four cycles he underwent resection of the proxim al fem ur and insertion of a cemented proxim al fem oral replacem ent replacing 61% of the fem ur. Pathological evaluation show ed greater than 95% necrosis of the tum our with wide m argins of resection.

D iscussion
T he outcom e of Ewings sarcom a treatment has improved dram atically with chem otherapy and surgery for patients w ho present free of m etastatic disease. D isease-free survival of 65% at 5 years is reported. 2,6 M ost relapses occur within the ® rst 2 years. 1± 3,5± 7 Relapse at 4 1 2 years with a solitary bone m etastasis is unusual but not unique. A late relapse at the sam e site as the initial tum our is exceedingly unusual.
The prognosis for patients who relapse is poor with 20% survival at 3 years in the C ESS 86 Study. 6 H owever, it has been show n in the sam e series that if the time to relapse is greater than 24 m onths from original diagnosis, then the prognosis im proves considerably, and in the CESS 86 series 3 4 patients with bone m etastasis appearing later than 24 m onths from diagnosis were still disease free at 4 years following relapse. Aggressive treatment with further chem otherapy and wide excisional surgery is clearly justi® ed in these cases.
Endoprosthetic replacement of the proximal fem ur is a well established surgical technique for replacing tum ours of the upper fem ur. 8±  He did very well, regaining near norm al function and achieving an Enneking functional score of 29 out of 30 (96%) at follow-up 4 years later. In F ebruary 1996, he started to get right thigh pain and w as found to have a solitary bone m etastasis in the right upper fem ur. H e was started on induction chem otherapy w ith EVAIA (etoposide, vincristine, adriam ycin ifosfam ide, actinomycin D ) and was kept non-weight-bearing on crutches. After the ® rst cycle of chem otherapy, he fell and sustained a pathological fracture through the right proxim al fem ur (Fig. 3). He was adm itted to hospital for traction and further chemotherapy. After tw o further cycles of chem otherapy, he underwent resection of the upper fem ur and insertion of a second endoprosthetic replacem ent, this time replacing 45% of the bone. T en days post-operatively, he was up w alking on crutches and was discharged after 14 days. H istology showed 50% necrosis of the tum our with clear m argins of resection. By 8 m onths following the second surgery the patient w as w alking without any sticks. Trendelenburgh is negative on the left but delayed positive on the right side. T he functional score is 76% on the right and 90% on the left side (Fig. 4). After 18 m onths he relapsed with further widespread bony m etastases. young and well m otivated and we would anticipate good functional recovery. The prognosis is clearly uncertain. W e ® rm ly believe that aggressive surgical reconstruction com bined with chem otherapy is justi® ed for these unusual cases.

A cknowledgem ent
Special thanks to M ichaela Fischler (Student of M edicine in U niversity of T ubingen in G erm any) for the translation of the Germ an articles into English. lever arm from its insertion of the greater trochanter. In all our patients the abductors are reattached to the fasc ia lata and while this can achieve a good functional abductor arm particularly in younger patients, m ost people will have a slight T rendelenberg dip and older patients frequently need to use a walking stick.
Another approach w ould be to treat with chemotherapy and local radiotherapy. D am ron et al. reported a 79% rate of pathological fracture following treatment of Ewings sarcom a of the proximal fem ur with radiotherapy. Increasing evidence suggests that the surgical m anagement of prim ary Ew ing' s sarcom a does give im proved rate of both survival and local control. 11,12 W e know of no case where bilateral endoprosthetic replacements of the upper fem ur for prim ary bone tum ours have been carried out. T he patient is