The pre-operative differentiation between enchondroma, low-grade chondrosarcoma and high-grade chondrosarcoma remains a diagnostic challenge. We reviewed the accuracy and safety of the radiological grading of cartilaginous tumours through the assessment of, first, pre-operative radiological and post-operative histological agreement, and second the rate of recurrence in lesions confirmed as high-grade on histology. We performed a retrospective review of major long bone cartilaginous tumours managed by curettage as low grade between 2001 and 2012. A total of 53 patients with a mean age of 47.6 years (8 to 71) were included. There were 23 men and 30 women. The tumours involved the femur (n = 20), humerus (n = 18), tibia (n = 9), fibula (n = 3), radius (n = 2) and ulna (n = 1). Pre-operative diagnoses resulted from multidisciplinary consensus following radiological review alone for 35 tumours, or with the addition of pre-operative image guided needle biopsy for 18. The histologically confirmed diagnosis was enchondroma for two (3.7%), low-grade chondrosarcoma for 49 (92.6%) and high-grade chondrosarcoma for two (3.7%). Three patients with a low-grade tumour developed a local recurrence at a mean of 15 months (12 to 17) post-operatively. A single high-grade recurrence (grade II) was treated with tibial diaphyseal replacement. The overall recurrence rate was 7.5% at a mean follow-up of 4.7 years (1.2 to 12.3). Cartilaginous tumours identified as low-grade on pre-operative imaging with or without additional image-guided needle biopsy can safely be managed as low-grade without pre-operative histological diagnosis. A few tumours may demonstrate high-grade features histologically, but the rates of recurrence are not affected.

Cite this article: Bone Joint J 2014; 96-B:1098–105.

Local recurrence along the biopsy track is a known complication of percutaneous needle biopsy of malignant musculoskeletal tumours. In order to completely excise the track with the tumour its identification is essential, but this becomes increasingly difficult over time. In an initial prospective study, 22 of 45 patients (48.8%) identified over a three-month period, treated by resection of a musculoskeletal tumour, had an unidentifiable biopsy site at operation, with identification statistically more difficult after 50 days. We therefore introduced the practice of marking the biopsy site with India ink. In all 55 patients undergoing this procedure, the biopsy track was identified pre-operatively (100%); this difference was statistically significant. We recommend this technique as a safe, easy and accurate means of ensuring adequate excision of the biopsy track.

Cite this article: Bone Joint J 2013;95-B:250–3.

Elastofibroma dorsi is an uncommon, benign, slow-growing soft-tissue tumour of uncertain aetiology. It classically presents as an ill-defined mass at the inferior pole of the scapula with symptoms which include swelling, discomfort, snapping, stiffness and occasionally pain.

We report the symptoms, function and outcome after treatment of 21 elastofibromas in 15 patients. All were diagnosed by MRI and early in the series four also underwent CT-guided biopsy to confirm the diagnosis. In all, 18 tumours were excised and three were observed. After excision, the mean visual analogue score for pain decreased from 4.6 (0 to 10) pre-operatively to 2.4 (0 to 8) post-operatively (p = 0.04). The mean shoulder function, at a mean follow-up of 4.2 years (3 months to 16 years), was 78.1% (30 to 100) using the Stanmore percentage of normal shoulder assessment scoring system. The mean range of forward flexion improved from 135° (70° to 180°) to 166° (100° to 180°) after excision (p = 0.005). In four patients a post-operative haematoma formed; one required evacuation. Three patients developed a post-operative seroma requiring needle aspiration and one developed a superficial infection which was treated with antibiotics.

Our findings support previous reports suggesting that a pre-operative tissue diagnosis is not necessary in most cases since the lesion can be confidently diagnosed by MRI, when interpreted in the light of appropriate clinical findings. Surgical excision in symptomatic patients, is helpful.

It has been suggested that elastofibroma is caused by a local tissue reaction and is not a true neoplastic process. A strong association has been noted between elastofibroma and repetitive use of the shoulder, which is supported by our findings.

Dedifferentiated chordoma is a rare and aggressive variant of the conventional tumour in which an area undergoes transformation to a high-grade lesion, typically fibrous histiocytoma, fibrosarcoma, and rarely, osteosarcoma or rhabdomyosarcoma. The dedifferentiated component dictates overall survival, with smaller areas of dedifferentiation carrying a more favourable prognosis. Although it is more commonly diagnosed in recurrences and following radiotherapy, there have been a few reports of spontaneous development. We describe four such cases, which were diagnosed de novo following primary excision, and discuss the associated clinical and radiological features.

Ultrasound (US) was used to determine the congruity of the shoulder in 22 children with a deformity of the shoulder secondary to chronic obstetric brachial plexus palsy. There were 11 boys and 11 girls with a mean age of 4.75 years (0.83 to 13.92). The shoulder was scanned in the axial plane using a posterior approach with the arm internally rotated. The humeral head was classified as being either congruent or incongruent. The US appearance was compared with that on clinical examination and related to the intraoperative findings. All 17 shoulders diagnosed as incongruent on US were found to be incongruent at operation, whereas three diagnosed as congruent by US were found to be incongruent at operation. The diagnostic accuracy of US for the identification of shoulder incongruity was 82% when compared with the findings at surgery. US is a valuable, but not infallible tool, for the detection of incongruity of the shoulder.

Osteofibrous dysplasia is a rare condition usually affecting the tibiae and fibulae of males in the first two decades of life. Involvement at the ulna has also been reported in some cases. We describe an extensive, rapidly progressive lesion of the ulna in a three-year-old girl. The progression of the disease accelerated after a local marginal removal, and required extensive resection of the ulna with reconstruction using a fibular autograft.

The particular features of this case are the change in the aggressive nature of the condition, which has not been previously reported. We believe that this is only the second recorded case of histologically proven involvement of the ulna.

Needle biopsy is an established technique for the histological diagnosis of bone tumours, usually guided by fluoroscopy or CT. Surface lesions and aggressive tumours which have extended through the cortex are also amenable to imaging with ultrasound (US). We have assessed the diagnostic accuracy of US-guided Trucut needle biopsy in a consecutive series of patients referred to a Bone Tumour Unit with suspected primary bone tumours. Of 144 patients (83 men, 61 women; mean age 34.7 years) referred over a period of two years, 63 were considered suitable for US-guided biopsy. This was based on the presence of a relatively large extraosseous component, seen typically in osteosarcoma and malignant round-cell tumours. The results of needle biopsy were compared with those of surgical biopsy. The diagnostic accuracy was 98.4%, with only a single failed biopsy.

Thus, in a selected group of patients, US is a very reliable technique of guidance for percutaneous needle biopsy of bone tumours.

Lateral oblique radiographs are considered important for the identification of spondylolytic lesions, but these projections will give a clear view only when the radiological beam is in the plane of the defect. We studied the variation in orientation of spondylolytic lesions on CT scans of 34 patients with 69 defects.

There was a wide variation of angle: only 32% of defects were orientated within 15° of the 45° lateral oblique plane. Lateral oblique radiographs should not be considered as the definitive investigation for spondylolysis.

We suggest that CT scans with reverse gantry angle are now more appropriate than oblique radiography for the assessment of spondylolysis. Variation in the angle of the defect may also need consideration when direct repair is being planned.

We have reviewed 13 operations on 11 patients using curettage and polymethylmethacrylate cement for giant-cell tumour of bone (GCT) to assess the value of radiology in the early detection of recurrence. There were four recurrences, the most specific radiological sign on plain radiography was lysis of 5 mm or more at the cement-bone interface. This preceded clinical signs by a mean of four months and was identified at a mean of 3.75 months after operation. There was not always a complete sclerotic margin around the cement, but when it was present, there was never evidence of recurrence. MRI was helpful in assessing cases with evidence of recurrence.

Frequent surveillance with plain radiography should continue for one year after operation irrespective of clinical signs of recurrence. When the appearance of the plain radiographs suggests recurrence, MRI should be performed and followed by image-guided needle biopsy.