Aims

Custom triflange acetabular components (CTACs) play an important role in reconstructive orthopaedic surgery, particularly in revision total hip arthroplasty (rTHA) and pelvic tumour resection procedures. Accurate CTAC positioning is essential to successful surgical outcomes. While prior studies have explored CTAC positioning in rTHA, research focusing on tumour cases and implant flange positioning precision remains limited. Additionally, the impact of intraoperative navigation on positioning accuracy warrants further investigation. This study assesses CTAC positioning accuracy in tumour resection and rTHA cases, focusing on the differences between preoperative planning and postoperative implant positions.

Significant controversy exists with regard to the nomenclature, treatment and outcome of a group of well-differentiated lipomatous tumours sometimes labeled as atypical lipomas. The purpose of this paper is to attempt to clarify these controversies by reporting our experiences with this lesion.

The clinical features and follow-up of seventy patients with the diagnosis deep atypical lipoma (DAL) and a minimum two-year follow-up were examined.

Sixty- one patients were treated here with their primary lesion. Thirty-three were female and 28 were male. Ages ranged from 11 to 83 years (mean 57 years). They typically presented with a long history (four weeks to ten years, mean 91 weeks) and a large mass (4 to 30 centimetres, mean 18 centimetres). Most lesions were located in the thigh. Following treatment by marginal excision alone, five patients had a local recurrence (8.2%). Three recurred once and two recurred twice. No patient had a metastasis or died as a result of the tumour. No lesion dedifferentiated. Eight of the nine patients seen here with a presumed recurrence actually had a recurrent atypical lipoma. All recurrences were treated by further marginal resections and one went on to have a further recurrence. None of these patients had a metastasis and no lesion dedifferentiated. The final patient with a suspected recurrence most likely had a radiation-induced sarcoma nine years following radiotherapy after the marginal excision of a recurrent atypical lipoma.

We believe the term atypical lipoma is appropriate for these tumours, as they appear not to have any metastatic potential, merely a propensity to recur locally. The chance of dedifferentiation is small and the role of radiotherapy in the causation of dedifferentiation is uncertain. We suggest that a simple marginal resection (shelling-out) is adequate treatment for these lesions. Radiotherapy should not be used.

The purpose of this study is to investigate the causes and characteristics of the aggressive solitary bone lesion in patients over the age of forty.

Over a four year period, 318 patients over the age of forty were referred to our institution with what we would define as an aggressive solitary bone lesion. Further investigation and diagnostic biopsy as appropriate were performed in all patients. The lesions were then defined according to their radiological appearance, pathology and site. The nature of these lesions was then subdivided into several broad groups. A diagnosis of primary bone sarcoma was found in 30% of these lesions. Plasmacytoma, lymphoma and metastases accounted for 13% each. Benign bone tumours, infection and non-oncological diagnoses accounted for 9%, 6% and 16% of lesions respectively.

Aggressive solitary bone lesions are often due to primary bone sarcomas. Metastases from a previously unrecognised primary malignancy account for less than one sixth of lesions. This study emphasises the need for appropriate investigation and biopsy of the aggressive solitary bone lesion.

The purpose of this study is to emphasise the necessity for caution in assuming the diagnosis of a metastasis when a solitary bone lesion is identified following a prior malignancy.

Bone lesions occurring in patients who have previously had a malignancy are generally assumed to be a metastasis from that malignancy. We reviewed 60 patients with a previous history of malignancy, who presented with a bone lesion that was subsequently found to be a different primary sarcoma of bone. These second malignancies occurred in three distinct groups of patients.

Patients with original tumours well known to be associated with second malignancies (5%)

Inappropriate biopsy and treatment of primary bone sarcomas compromises limb salvage surgery and can affect patient mortality. We would advise referral of any aggressive solitary bone lesion to a regional bone tumour service for further assessment and biopsy rather than to assume the lesion is a metastasis.