Amputation was once widely practised for primary bone tumours of the limbs. Yet this situation has changed with limb salvage surgery becoming increasingly popular in the last 30 years. Many different techniques are now available. These include allografts, autografts, endoprostheses and allograft-prosthesis composites. This article reviews these methods, concentrating on the functional outcomes and complications that have been reported.
Since1986 we have monitored the actual diagnosis of all cases referred to our Unit with the diagnosis of ‘possible primary malignant bone tumour’. We have excluded all patients referred with a known diagnosis of either a benign condition or known to have bone metastases. In most cases the suspected diagnosis was based on X-rays alone, sometimes supported by further imaging. Retrospective review of a prospective database that was started in 1986 identifying the actual diagnosis. There were 5922 patients with a confirmed diagnosis over the 23 year time period of this study. 2205 (37%) were found to have a primary malignant bone sarcoma and 1309 (22%) had a benign bone tumour. 992 patients had a general orthopaedic condition (e.g. geode or a vascular necrosis) whilst 303 (5%) had a haematological malignancy and 289 (4.9%) infection. 533 patients (9%) had metastases. There was a similar pattern of frequency of all diagnoses except for metastatic disease and haematologic malignancy at different ages. The incidence of metastases increased from the age of 35 onwardsMethod
Results
Of 3000 patients diagnosed with primary malignant bone tumours and treated at our unit over the past 25 years, 234 (7.8%) were considered to be spindle cell sarcomas of bone (ie not osteosarcoma, chondrosarcoma, Ewing’s, chordoma or adamantinoma). We have analyzed their management and outcomes. The diagnosis of these cases varied with fluctuations in the popularity of conditions such as MFH, fibrosarcoma and leiomyosarcoma with the passage of time. Treatment was with chemotherapy and surgery whenever possible. 36 patients had metastases at diagnosis and 17 had palliative treatment only because of age or infirmity. The most common site was the femur followed by the tibia, pelvis and humerus. The mean age was 45 and the mean tumour size 10.2cm at diagnosis. 25% of patients presented with a pathological fracture. Chemotherapy was used in 70% of patients the most common regime being cisplatin and doxorubicin. 35% of patients having neoadjuvant chemotherapy had a good (>
90% necrosis) response. The amputation rate was 22% and was higher in patients presenting with a fracture and in older patients not having chemotherapy. With a mean follow up of 8 years the overall survival was 64% at 5 yrs and 58% at 10 yrs. Adverse prognostic factors included the need for amputation, older age and poor response to chemotherapy as well as a pathological fracture at presentation. The few patients with angiosarcoma fared badly but there was no difference in outcomes between patients with other diagnoses. We conclude that patients with spindle cell sarcomas should be treated similarly to patients with osteosarcoma and can expect comparable outcomes. The histological diagnosis does not appear to predict behaviour.
The two week wait has been established as a potential means of diagnosing malignant tumors earlier and thus hopefully leading to improvements in outcome. There remains controversy as to whether these clinic achieve this end or whether they just speed up treatment of patients already diagnosed (eg by imaging)
Endoprosthetic replacement of the pelvis is one of the most challenging types of limb salvage surgery with a high rate of complications. In order to try and decrease the high risk of complications and to allow greater versatility in the reconstruction options, a new concept of pelvic endoprosthesis was developed in 2003. Since then 20 of these ice cream cone pelvic prostheses have been inserted at our centre incorporating antibiotic laden cement around the prosthesis to minimize infection risk.
Low grade central osteosarcoma is a rare intramedullary bone producing tumour. It accounts for only 1–2% of all osteosarcomas. Due to the indolent nature of low grade central osteosarcoma, achieving a correct and prompt diagnosis is the real challenge both from imaging and histology, particularly as it may resemble a benign condition, i.e. Fibrous Dysplasia. We have reviewed 15 cases of low grade central osteosarcoma with long term follow-up (2 to 22 years) to identify problems in diagnosis and treatment and to assess outcome. There were 7 females and 8 males with a mean age of 37 yrs (range 11 to 72 years); 13 cases arose in the lower limb (8 femur, 4 tibia, 1 os calcis), 1 in the pelvis and 1 in the upper limb. The average duration of symptoms prior to presentation was over 2yrs. A primary diagnosis of low grade central osteosarcoma was achieved for only 6 cases (4 open and 2 needle biopsies), in the other 9 the primary diagnoses were GCT, cystic lesion or fibrous lesion (both benign and malignant) and all of them had undergone treatment (usually curettage with or without bone grafting for this). Definitive treatment was with surgery attempting to obtain wide margins. Marginal excision was associated with local recurrence in three cases but there were no local recurrences in patients who had a wide excision, even in those with prior treatment. Only one patient has died following the development of multiple metastases after 9 years. The survival rate is 90% at 15 years. We present this study to show the difficulties in diagnosing this rare type of osteosarcoma and to highlight the importance of wide surgical margins to obtain local control.
LR arose in 11 patients (17.5%) at a mean of 38 months and was related to surgical margins. There were no LR in the 26 wide resections, but the risk of LR was 20% in those with a marginal and 46% in those with an intralesional excision. LR appeared as a higher grade than the primary tumor in 3 patients (27%). 9 (14.3%) patients developed metastases at a median of 22 months (6 – 123). Five patients developed both LR and metastases. Seven patients died from the tumor, 2 patients are alive with metastatic disease. None of the patients with a low grade tumor and wide or marginal margins died of tumor, but 2 patients (18%) operated intralesional died of tumor.
Ewing’s sarcoma principally arises in bone but can also present as a soft tissue tumour. Very few studies have assessed the outcomes of extra-skeletal Ewing’s sarcomas. This study compares the oncological outcomes of the two forms of Ewing’s sarcomas to see if there is any difference in prognostic factors. 198 patients with primary, non metastatic Ewing’s sarcoma diagnosed between 1980 and 2005 were identified from our database. There were 118 males and 80 females with a median age of 15 years. The three most common sites of diagnosis were the femur (24%), pelvis (15%) and tibia (13%). There were 169(85%) bony Ewing’s and 29 (15%) extra-skeletal Ewing’s sarcomas. All patients received chemotherapy. 86% of the patients had surgery for local control but 28(14%) patients had radiotherapy. The overall survival at five years was 89% and was related to the age of patient (92% <
16years p=0.005), size (p=0.03) and site of tumour (p=0.004) as well as the response to chemotherapy. There was no difference in the overall survival of patients with bony Ewing’s (90%) and extra-skeletal Ewing’s (85%) (p=0.85). There was a 10% risk of local recurrence at 5 years with site of tumour (p=0.01) and surgical excision (p=0.05) being significant prognostic factors. The risk of local recurrence was also not related to the type of Ewing’s sarcoma. This large series has shown that the oncological outcomes of Ewing’s sarcoma is related to tumour characteristics, patient age and treatment factors and not determined by the tissue component.
Of the 7242 patients with soft tissue lumps, 476 had a past history of malignancy. Of these patients, only 12% actually had a soft tissue metastasis while 28% had a benign diagnosis, 55% a soft tissue sarcoma and 5% other malignancy.
Our centre has used a specially designed custom-made endoprostheses with curved stems to reconstruct femoral defects in patients with residual short proximal femur after excision of primary bone sarcoma over the last 18 years. Two designs of endoprostheses with curved intramedullary stems were used: the rhinohorn stem type and the bifid stem type. We report the safety, survival and functional outcome of this form of reconstruction. Twenty six patients who had these special endoprosthesis reconstruction were studied. The median age was 16 years (range 7 to 60 years). Prostheses with rhino horn stems were used in 15 patients and bifid-stem in 1 1 patients. Twenty patients had the prostheses inserted as a primary procedure after excision of primary bone sarcoma, and in six patients the prostheses were inserted after revision surgery of failed distal femur endoprostheses. Seventeen patients (65%) were alive and free of disease at a median follow-up of 98 months (12 to 203 months) and nine patients had died of metastatic disease. Local recurrence developed in two patients (1 0%) out of the 20 patients. Surgical complications occurred in five patients (191/o). Deep infections occurred in two patients (8%) requiring revision surgery in one patient. Prosthetic failure, occurred in nine patients (35%). The cumulative survival of prostheses was 69% at five years and 43% at 10 years. Musculoskeletal Tumour Society mean functional score was 83% (53% to 97%). In conclusion, preservation of a short segment of the proximal femur and the use of endoprostheses with curved stems for reconstruction of the femur is technically possible. There is an increased risk of fracture of the prostheses decreasing the survival rate. Functional outcome of patients with this form of reconstruction is not significantly different from the functional outcome of patients who have proximal femur or total femur endoprosthetic reconstruction. This operation is particularly desirable in skeletally immature patients and allows normal development of the acetabulum.
Deep prosthetic infections are a significant cause of failure after arthroplastic surgery. Superficial wound infections are a risk factor for deep infections. We aimed to quantify the risk of deep infection after superficial wound infections, and analyse the microbiology of organisms grown. We defused Superficial Infection according to the definition used by the Centre for Disease Control, and Deep Infection according to the Swedish Hip Register. We retrospectively analysed the results of 6782 THR and TKRs performed consecutively from 1988–1998. We analysed patient records, radiology and microbiological data. The latter collected prospectively by our infection control team. We identified 81 (1. 2%) superficial wound infections, however we had to exclude 3 due to poor follow-up. Of the 78 patients studied, mean age was 71 (23–89), 50 were female, 28 male, 41 THR, 37 TKR and follow-up was a mean 49 months (12–130). The majority (81%) of organisms grown in the superficial wound infections were gram positive Staphylococci. These organisms were most frequently sensitive to Erythromycin or Flucloxacillin. All the superficial infections were treated with antibiotics, 66% settled with less than 6 weeks therapy. Deep prosthetic infections occurred in 10% of superficial infections in both THR and TKR. In 80% of cases the organism in the superficial infection caused the deep infection. Wound dehiscence, haematoma, post-op pyrexia and patient risk factors had no affect on onset of deep infection. However patients who had a wound discharge with positive microbiology and those patients in whom there was clinical doubt about the diagnosis of deep infection and thus had antibiotic therapy for more than six weeks had increased risk of deep sepsis.
Inadvertent excision of lumps which turn out to be soft tissue sarcomas is still unfortunately quite common. It is known as the “whoops” procedure. Determining whether there is residual disease is key to deciding subsequent management. The value of MRI has been assessed. All new patients referred to our unit with a potential diagnosis of a “whoops” lesion were routinely reassessed with MR1 6 weeks after the initial operation. Notwithstanding the result of the scan all patients underwent a further wide excision of the involved area shortly after the MRI. The scans of these patients have been reviewed and classified into positive, equivocal or negative. These results have been compared with the histological assessment of the re- excision specimen to determine the accuracy of MR1 in predicting the presence of residual tumour. Of 887 patients with newly diagnosed soft tissue sarcomas seen in an 8 year period, 140 (11 %) had previously had a ‘whoops” procedure. Of these 111 had re-evaluation MR1 scans and had also undergone a further re-excision. There was residual tumour in 63 (57%) patients, whilst 48 (43%) had no residual tumour. The sensitivity of MRI in predicting tumour was 64% but specificity 93%. Positive predictive value was 93% and negative predictive value 67%. Overall accuracy was 77%. MRI is useful in identifying residual tumour after a whoops procedure but a negative result by no means excludes it. Re-excision remains essential despite the MRI results in most cases to ensure tumour clearance. Preventing the “whoops” procedure is clearly the best option of all!
Endoprosthetic Replacements are one of the most commonly used types of limb salvage following surgical excision of bone tumours. The advantages of Endoprosthetic Replacements are their initial reliability and the rapid restoration of function along with their ready availability. The problems with Endoprosthetic Replacements are the long term problems of wear, loosening, infection and mechanical failure. Increasing and insolvable problems may lead to the necessity for amputation. This paper assesses the risk of amputation following Endoprosthetic Replacement. A total of 1262 patients have undergone Endoprosthetic Replacement surgery at our centre in the past 34 years. They have a total of 6507 patient years of follow up. A total of 112 patients have had subsequent amputation (8. 9%). The reasons for amputation were local recurrence in 71(64. 4%), infection in 38(33. 9%), mechanical failure in 2(1. 8%) and continued pain in 1 case (0. 8%). The risk of amputation was greatest in the proximal tibia 15. 5% (n=38/246), followed by pelvis 10. 2%(5/49), and femur 7. 4% (n=58/784), whilst the risk of amputation was least in the humerus at 6. 4% (n= 1l/182). The time to amputation varied from 2 days to 16. 3 7 years, with a mean of 31 months. The risk of amputation decreased with time although 10% of the amputations took place more than 5 years after implantation. The greatest risk of amputation is in the first 5 years and is due to local recurrence, whilst infection poses the next greatest threat. The risk decreases with time. Attempts to control both local recurrence and infection will decrease the need for amputation. Late failure of the endoprosthetic replacements, even in young patients does not seen to be a major cause of amputation thus far.