Professional Guidelines Included
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Endoprosthetic replacements of the proximal femur are one of the most common limb-salvage procedures undertaken to reconstruct massive bone defects secondary to tumour, trauma or infection.
The increasing burden of metastatic bone disease means more cases present to orthopaedic surgeons. Breast cancer is the most common cancer in women and because of advances in systemic therapy, is now considered a chronic disease in many cases. Two thirds of breast cancer patients will develop skeletal metastases which cause skeletal related events (SREs: pathological or impending fracture, hypercalcaemia, spinal cord compression, severe pain) which may require surgery and/or radiotherapy to palliate pain and to preserve mobility and quality of life.
For patients with subtrochanteric bone tumour involvement, fracture and patients with a good prognosis may best be managed with endoprosthetic replacement. Resection of a tumour from the proximal femur requires reconstruction of the large bone and soft-tissue defect and the complications of such surgery from a systematic review include dislocation (5.8%), infection (5.2%), local recurrence (4.7%) and peri-prosthetic fracture (0.6%). These are both reliable and durable implants that offer immediate mobility and return to function; however in the long-term complications and failure mean that ten year implant survival is approximately 75%.
Author :Mr Jonathan Stevenson FRCS (Tr & Orth)
Institution :The Royal Orthopaedic Hospital Birmingham ,UK.
Clinicians should seek clarification on whether any implant demonstrated is licensed for use in their own country.
In the USA contact: fda.gov
In the UK contact: gov.uk
In the EU contact: ema.europa.e
INDICATIONS:
The indications for proximal femoral endoprosthetic replacement are to reconstruct massive bone defects following malignancy, infection, trauma or failed arthroplasty. In oncology, tumours may either be primary or metastatic (secondary) bone tumours, or soft tissue sarcomas which have invaded the bone. Within this group pathological fractures may develop, where by the bone is weakened to the point of failure by the presence of the tumour.
The incidence of deep prosthetic joint infection following total hip replacement is approximately 1%. The treatment for infected hip replacements may involve explanting the infected prosthesis and insertion of a new prosthesis. Recurrent infections may be difficult to treat particularly when dealing with bone loss from previous surgeries which may necessitate endoprosthetic reconstruction.
Failed internal fixation of proximal femoral bone loss, particularly in osteoporotic bone, may lead to sever bone loss: endoprostheses replace this lost bone expeditiously which may be essential in comorbid patients with osteoporosis.
SYMPTOMS & ASSESSMENT:
Biopsy tract, range of motion of hip and knee, limb length, deformity, neurovascular status, skin quality including previous scars and sinuses, abductor function, availability of local soft tissue flaps as required.
INVESTIGATION:
Measured radiographs of the whole femur, pelvic AP radiograph
MRI whole femur including hip joint
Staging dependent upon histological diagnosis (in this case CT chest-abdomen-pelvis to exclude visceral metastasis, whole-body bone scintigraphy to identify other skeletal metastases)
OPERATIVE ALTERNATIVES:
Primary malignant bone tumours: Allograft or allograft prosthetic composite
Subtrochanteric metastases in the presence of fracture and/or multiple osseous or visceral metastases with limited life expectancy: medullary nail or plate with cement augmentation
NON-OPERATIVE ALTERNATIVES:
Radiotherapy
Systemic therapy (which for breast cancer includes hormone therapy, chemotherapy, denosomab and bisphosphonates)
CONTRAINDICATIONS:
Active osteomyelitis
Poor soft tissue coverage (if plastics surgical flap not available)
Insufficient distal bone stock to accept medullary stem necessitating total femoral endoprosthesis
Paediatric patient too young and small to receive custom growing prosthesis
GA + spinal
Prophylactic antibiotics, ultra clean theatre
Lateral decubitus position with hip props, pillow between calves, exclusion drape
Double alcoholic skin prep, hip and thigh exposed, calf and foot excluded by drapes, ioban incise drapes
VTE prophylaxis: early mobilisation protected weight bearing with crutches, LMWH chemoprophylaxis dose at least 6 hours post-operatively for 4 weeks, thigh lengths TED stockings for 6 weeks and foot pumps or flowtrons (calf compression devices) until mobile
VTE prophylaxis: early mobilisation protected weight bearing with crutches, LMWH chemoprophylaxis dose at least 6 hours post-operatively for 4 weeks, thigh length TED stockings for 6 weeks and foot pumps or flowtrons (calf compression devices) until mobile (Lex et al. Venous thromboembolism in orthopaedic oncology: risk factors, incidence, and prophylaxis. Bone Joint J 2020;102-B(12)1743:–1751 doi.org/10.1302/0301-620X.102B12.BJJ-2019-1136.R3)
Crutches 6 weeks, then wean to one crutch 6-12 weeks
Readmission for inpatient hydrotherapy after 6 to 8 weeks to facilitate weaning off crutches
3 post-operative doses of antibiotics
X-rays when safe, AP right proximal femur and hip
wound check 14 days, routine outpatients at 6 weeks, 6 months and then annually (unless the disease burden prevents regular clinic attendance)
Radiotherapy via oncologists after histology report and MDT discussion
British Orthopaedic Oncology Society – Metastatic Bone Disease: A guide to good practice. 2015
There are two aims in metastatic bone disease: the first is to prolong survival with oligometastatic disease; the second is to control pain and preserve function and avoid fracture. Any operation should outlive the patient i.e. no revision surgery due to mechanical failure should be required. In this patient the initial operation (long stem cemented total hip replacement) failed to address the primary aim. All patients with metastatic bone disease can be discussed with specialist orthopaedic oncologists at tertiary centres around the country, if only for advice remotely. Other guidelines described by the British Orthopaedic Oncology Society include never assuming that a bone lesion is solitary and if it is solitary after staging with CT chest/abdo/pelvis and whole body bone scanning, it should be referred to a specialist centre for biopsy.
Stevenson et al. Journal of Bone Joint Surgery 2018;100: 101-8.
Proximal femoral endoprostheses are durable and reliable reconstructions even in patients with comorbid conditions (Khajuria et al. Hip Int 2017) and recently were shown to have eliminated the risk of dislocation when used with hemiarthroplasty heads in the short term. Implant survival after five years is between 87% and 95%.
Henderson et al. Failure mode classification for tumour endoprostheses: retrospective review of five institutions and a literature review. Journal of Bone Joint Surgery Am 2011;93(5):418-29.
Causes of implant failure and revision include infection, aseptic loosening, dislocation, local tumour recurrence and structural failure. For the purposes of standardising the reporting of endoprosthetic related complications the Henderson classification is now used to subdivide the modes of failure into: soft-tissue failures (Type 1), aseptic loosening (Type 2), structural failures (Type 3), infection (Type 4), and tumor progression (Type 5)
Reference
- orthoracle.com
