Trucut biopsy needle

This video from YouTube illustrates the use of a Trucut biopsy needle. These needles can be used to obtain specimens of soft tissue tumours, often under ultrasound guidance.

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Guide to trainees for the orthopaedic oncology rotation

We have compiled the following unofficial guide to trainees coming to the North of England Bone and Soft Tissue Tumour Service. It contains key topics in the curriculum to which you may get exposure in this attachment, competence levels for surgical procedures and other useful information.

Orthopaedic Oncology Syllabus

Limb reconstruction in children

Limb reconstruction in children after the resection of bone tumours is associated with the following particular issues:

  • Growth – predicted final leg length discrepancies of more than 3cm are most often addressed using an extendible implant, eg the Stanmore Juvenile Tumour System. The paper by Cool et al suggests how to calculate the expected growth if bone age is known.
  • Longevity of reconstruction – endoprosthetic reconstructions in children are inevitably associated with the need for revision – biological reconstructions may be preferred
  • Adaptation – children may be more able to adapt to loss of function than adults
  • Amputation – amputation in a child can lead to disproportionate limb length discrepancy at skeletal maturity, and trans-osseous amputations can overgrow and require revision. For this reason, amputations through joints may be preferred.
  • Radiotherapy – adjuvant radiotherapy can affect growth plates
  • Acetabular deformity – hemiarthroplasty of the hip is associated with subluxation as growth occurs, particularly for children under 11 years of age (1). A Collona arthroplasty of the acetabulum in which the acetabulum is reamed to deepen the socket may help. Otherwise a shelf osteotomy may be needed in later life.

(1)  van Kampen M, Grimer RJ, Carter SR, Tillman RM, Abudu A. Replacement of the hip in children with a tumor in the proximal part of the femur. J Bone Joint Surg Am. 2008 Apr;90(4):785-95.

Aseptic loosening of massive tumour endoprostheses

Reconstruction of the limb with a massive endoprosthesis after tumour resection is associated with a risk of aseptic loosening. A number of factors influence this risk. These include:

  • anatomical site
  • length of resection
  • muscle resection
  • possibly the use of a fixed hinge knee rather than a rotating hinge knee
  • the use of a hydroxyapatite collar

The risk of aseptic loosening is likely highest in the distal femur (13.6%) compared with the proximal femur (11%) and pelvis (7%), but in this paper, implants were also revised for other reasons, including deep infection (1).

Reference
(1) Endoprosthetic Reconstruction for the Treatment of Musculoskeletal Tumours of the Appendicular Skeleton and Pelvis.Jeys LM, Kulkarni A, Grimer RJ, Carter SR, Tillman R, Abudu A.  J Bone Joint Surg Am. 2008; 90: 1265-1271.

Infection after major tumour resection and endoprosthetic reconstruction

Infection remains a major problem after major tumour resection and endoprosthetic reconstruction.  Placing a large metal implant into a wound which has typically been open for several hours, in an immunocompromised patient is associated with higher infection rates than for other procedures.

In the paper by Jeys et al. , the overall rate of infection was 11.0%, most frequently with a coagulase negative staphylococcus. The risk varies significantly with anatomical site. For example, because of the limited skin cover, resection of the proximal tibia has traditionally been associated with high infection rates. The routine use of a gastrocnemius pedicled flap to improve soft tissue cover has improved this risk. Reconstruction of the pelvis has also traditionally been associated with a high infection rate (23%) compared with other sites (proximal femur 6.7%, distal femur 10.3%). Other risk factors include the use of radiotherapy, secondary patellar resurfacing, and the use of an extendable implant. Deep infection may require a secondary amputation.

Interestingly, there is evidence that deep infection is associated with improved survival in patients with osteosarcoma, likely through stimulation of the immune system. Jeys et al showed a 10-year survival for patients with osteosarcoma who had a deep infection within the first year post-resection of 84.5% compared to 62.3% in the non-infected group. Improved survival has also been shown in osteosarcoma with the use of Mifamurtide (a synthetic immune stimulant). Read more about Mifamurtide.

Strategies for reducing the rate of infection include:

  • screening the patient for infection preoperatively (central lines have the potential to increase the rate of infection)
  • repeating the antibiotic dose during long procedures, especially where there has been significant blood loss
  • re-draping and re-gowning after tumour resection and before placing the implant
  • using silver coated implants
  • ensuring the implant  is well covered with muscle and fascia as well as skin, given the high risk of wound complications after tumour surgery.

Reference:

Periprosthetic infection in patients treated for an orthopaedic oncological condition. Jeys LM, Grimer RJ, Carter SR, Tillman RM. J Bone Joint Surg Am. 2005;87: (842-849).

Post operative infection and increased survival in osteosarcoma patients: are they associated? Jeys LM, Grimer RJ, Carter SR, Tillman RM, Abudu A. Ann Surg Oncol. 2007;14(10):2887-95.

 

Complications of endoprosthetic reconstruction

The major complications particular to endoprosthetic reconstruction of the limb following tumour resection include:

  • infection
  • aseptic loosening
  • dislocation
  • wear
  • implant fracture
These are in addition to other complications associated with major tumour resection, regardless of the kind of reconstruction, which include:
  • wound complications
  • thromboembolism
  • neurological injury
  • vascular injury
Local recurrence of tumour might be considered a failure of local therapy, rather than a complication.