Table 1.

Patients’ features

	n (total)	Surgical treatment	Side	Sex	Mean duration of symptoms (months)	Surgical procedure	Mean age at surgery (years)	Mean follow-up (years) in patients with surgery	Recurrence rate	Status
Benign cases	75	64	36 right, 39 left	27 F, 48 M	11.4 (range 1–60)	62 curettages, 1 amputation, 1 asp/bm	72.5 (range 5–78).	4.8 (range 1 month–14 years)	0	64 NED, 7 AWD, 4 LOST
Malignant cases	17	13	12 right, 5 left	6 F, 11 M	17.2 (range 1–60)	7 curettages, 4 amputations below knee, 2 not documented	35.3 (range 8–68). For primary malignant cases: 27.1 (range 8–38)	4.4 (range 0 months–13.8 years). For primary malignant cases: 4.6 (range 0 months–13.9 years)	3	8 DOD, 5 NED, 3 AWD, 1 LOST

Sixty-nine patients had no evidence of disease and ten were alive with disease (AWD). Five patients were lost to follow-up and eight patients died of disease (four osteosarcomas, three metastases, one Ewing’s sarcoma). Patients with primary malignant disease had a 4.6-year mean follow-up (range 0–13.9). For all malignant conditions, the mean age at surgery was 35.3 years (range 8–68). All patients with benign tumours who underwent surgery remained free of recurrence. Sixty-two curettages were documented as well as one injection of bone marrow and one below knee amputation due to a desmoplastic fibroma. For benign lesions, the mean age at surgery was 72.5 years (range 5–78)

asp/bm aspiration/bone marrowNED no evidence of disease, AWD alive with disease, DOD dead of disease, LOST lost to follow-up