Tumours of the sacrum are difficult to manage. The sacrum provides the structural connection between the torso and lower half of the body and is subject to both axial and rotational forces. Thus, tumours or their treatment can compromise the stability of the spinopelvic junction. Additionally, nerves responsible for lower limb motor groups as well as bowel, bladder, and sexual function traverse or abut the sacrum. Preservation or sacrifice of these nerves in the treatment of sacral tumours has profound implications on the function and quality of life of the patient. This annotation will discuss current treatment protocols for sacral tumours. Cite this article: Bone Joint J 2022;104-B(12):1284–1291

The April 2023 Oncology Roundup. 360. looks at: Complete tumour necrosis after neoadjuvant chemotherapy defines good responders in patients with Ewing’s sarcoma; Monitoring vascularized fibular autograft: are radiographs enough?; Examining patient perspectives on sarcoma surveillance; The management of sacral tumours; Venous thromboembolism and major bleeding in the clinical course of osteosarcoma and Ewing’s sarcoma; Secondary malignancies after Ewing’s sarcoma: what is the disease burden?; Outcomes of distal radial endoprostheses for tumour reconstruction: a single centre experience over 15 years; Is anaerobic coverage during soft-tissue sarcoma resection needed?; Is anaerobic coverage during soft-tissue sarcoma resection needed?

Giant-cell tumours of the sacrum are difficult to treat. Surgery carries a high risk of morbidity, local recurrence and mortality. Radiation is effective in some patients, but has a risk of malignant change.

We evaluated the effectiveness of serial arterial embolisation as an alternative to surgery. Five patients with giant-cell tumours of the sacrum which had been primarily treated by serial embolisation were retrospectively reviewed for changes in the size of the tumour. In four the symptoms resolved with full return of function and arrest in the growth of the tumour. They remained free from growth, recurrence, or metastases at follow-up (4 to 17 years). One patient died from metastatic disease within 18 months of the initial diagnosis.

Aims. The aim of this study was to investigate the local recurrence rate at an extended follow-up in patients following navigated resection of primary pelvic and sacral tumours. Patients and Methods. This prospective cohort study comprised 23 consecutive patients (nine female, 14 male) who underwent resection of a primary pelvic or sacral tumour, using computer navigation, between 2010 and 2012. The mean age of the patients at the time of presentation was 51 years (10 to 77). The rates of local recurrence and mortality were calculated using the Kaplan–Meier method. Results. Bone resection margins were all clear and there were no bony recurrences. At a mean follow-up for all patients of 59 months (12 to 93), eight patients (34.8%) developed soft-tissue local recurrence, with a cumulative rate of local recurrence at six-years of 35.1% (95% confidence interval (CI) 19.3 to 58.1). The cumulative all-cause rate of mortality at six-years was 26.1% (95% CI 12.7 to 49.1). Conclusion. Despite the positive early experience with navigated-assisted resection, local recurrence rates remain high. With increasing knowledge of the size of soft-tissue margins required to reduce local recurrence and the close proximity of native structures in the pelvis, we advise against compromising resection to preserve function, and encourage surgeons to reduce local recurrence by prioritizing wide resection margins of the tumour. Cite this article: Bone Joint J 2019;101-B:484–490

It is frequently difficult to diagnose and treat of malignant sacral bone tumors. This tumor is diagnosed with lumbar disc hernia, instability coccygitis, hemorrhoids. We reviewed the surgical treatment of primary malignant (14) and secondary (metastatic) sacral tumors (11) in 25 patients from 1983 to 2000. Primary tumors consisted of chordoma in 11 patients, chordoma with spindle cell sarcoma, malignant peripheral nerve sheath tumor (MPNST), giant cell tumor of bone in 1 patient each. The secondary tumors consisted of invading carcinoma in 7 patients, metastatic carcinoma in 4 patients. Location of the sacral tumor was showed total sacrum in 2 patients, below S2 in 18, S3 in 2 and S4 in 3. Preserving nerves were L5 in 1 patient, S1 in 17, S2 in 2, S3 in 3, and 2 performed curettage. Posterior approach was used in 8 patients, and an anterior and posterior combined approach in 17. Sacrectomy only in 7 patients, and sacrectomy and colostomy in 8, including with rectum was performed in 8, and 2 patients had extensive curettage and bone graft or hydroxyapatite (HA) transplantation. Six tumor excisions were used modified T-saw which pass through the sacral canal preserving nerve roots. Surgical margin of chordoma in primary sacral tumors had wide in 10, wide excision with partial contamination in 2, except curettage in 1. MPNST had curettage and giant cell tumor of bone had marginal in 1 each. Secondary sacral tumors had wide in 9, marginal in 2. Adjuvant therapy was used radiation therapy in 3 patients and chemotherapy in 2 and ethanol in 1. Musculocutaneous flap was reconstracted tensor fascia lata flap and gluteal muscle flap in 2 patients. Interval between initial chief complaints and diagnosis of chordoma detected from 6 months to 10 years, avarage 5 years 3 months by rectal examination, radiogram, genital ultra echo and MRI; invading carcinoma from 2 months to 3 years, avarage 8 months, and metastatic carcinoma from 2 months to 4 months, average 3 months. Six of 12 patients of chordoma in primary sacral tumors are alive from 6 months to 18 years, average 4 years 6 months; remaining patients were died 6 month to 8 years, average 3 years 2 months, except 2 patient died with infection. The patient with a MPNST died after 2 years 6 months, and a giant cell tumor of bone had no recurrence or lung metastases in 10 years. One of 11 patients of secondary sacral tumor (initial surgery) is alive in 14 years 6 months, remaining 10 patients died 3 months to 4 years 6 months, average 1 year 10 months, except 2 patients died with infection. Complications were much bleeding, infection, skin slough, nerve injury. We recommend better surgical method that anterior and posterir approach use above S3, and posterior approach blow S4, A modified T-saw performed an osteotomy of the pars lateral of the sacrum, proved to be easier and faster than osteotomies performed using the old method

Aim: Sacral tumours are rare and can form a wide variety of differential diagnoses. We present a series of sacral tumour patients treated at a regional tumour centre; describing our experience of their management. Method: A retrospective study reviewing 76 sacral tumour patients, presenting to the Royal National Orthopaedic Hospital, Stanmore, from April 1976 to April 2002. The minimum follow-up period was 6 months. For each tumour type we looked at the incidence, diagnosis and outcome. Results: 69 of the lesions were primary bone tumours, 3 metastatic and 4 haematopoietic tumours. 33% of all tumours were chordomas. Osteosarcoma (10%), chondrosarcoma (8%) and giant cell tumour (8%) were the next most common. The commonest presenting symptom was lower back pain (64 cases). Good survival was demonstrated with chordomas and giant cell tumours. Osteosarcomas and chondrosarcomas had poor survival. Tissue diagnosis was accurately achieved with image-guided needle biopsy (61 cases). Magnetic resonance imaging (MRI) and computed tomography (CT) provided sufficient details for preoperative planning. Conclusion: The symptoms and signs of sacral tumours are non-specific and may lead to a misdiagnosis of degenerative disease of the spine. In our series chordomas account for only a third of all sacral tumours. Early diagnosis and staging are essential in order to determine definitive management and infl uence outcome. Surgery remains the most effective method for treating the malignant tumours

Aims. Orthopaedic and reconstructive surgeons are faced with large defects after the resection of malignant tumours of the sacrum. Spinopelvic reconstruction is advocated for resections above the level of the S1 neural foramina or involving the sacroiliac joint. Fixation may be augmented with either free vascularized fibular flaps (FVFs) or allograft fibular struts (AFSs) in a cathedral style. However, there are no studies comparing these reconstructive techniques. Methods. We reviewed 44 patients (23 female, 21 male) with a mean age of 40 years (SD 17), who underwent en bloc sacrectomy for a malignant tumour of the sacrum with a reconstruction using a total (n = 20), subtotal (n = 2), or hemicathedral (n = 25) technique. The reconstructions were supplemented with a FVF in 25 patients (57%) and an AFS in 19 patients (43%). The mean length of the strut graft was 13 cm (SD 4). The mean follow-up was seven years (SD 5). Results. There was no difference in the mean age, sex, length of graft, size of the tumour, or the proportion of patients with a history of treatment with radiotherapy in the two groups. Reconstruction using an AFS was associated with nonunion (odds ratio 7.464 (95% confidence interval (CI) 1.77 to 31.36); p = 0.007) and a significantly longer mean time to union (12 months (SD 3) vs eight (SD 3); p = 0.001) compared with a reconstruction using a FVF. Revision for a pseudoarthrosis was more likely to occur in the AFS group compared with the FVF group (hazard ratio 3.84 (95% CI 0.74 to 19.80); p = 0.109); however, this was not significant. Following the procedure, 32 patients (78%) were mobile with a mean Musculoskeletal Tumor Society Score 93 of 52% (SD 24%). There was a significantly higher mean score in patients reconstructed with a FVF compared with an AFS (62% vs 42%; p = 0.003). Conclusion. Supplementation of spinopelvic reconstruction with a FVF was associated with a shorter time to union and a trend towards a reduced risk of hardware failure secondary to nonunion compared with reconstruction using an AFS. Spinopelvic fixation supplemented with a FVF is our preferred technique for reconstruction following resection of a sacral tumour. Cite this article: Bone Joint J 2021;103-B(8):1414–1420

We hypothesised that the use of computer navigation-assisted surgery for pelvic and sacral tumours would reduce the risk of an intralesional margin. We reviewed 31 patients (18 men and 13 women) with a mean age of 52.9 years (13.5 to 77.2) in whom computer navigation-assisted surgery had been carried out for a bone tumour of the pelvis or sacrum. There were 23 primary malignant bone tumours, four metastatic tumours and four locally advanced primary tumours of the rectum. The registration error when using computer navigation was <  1 mm in each case. There were no complications related to the navigation, which allowed the preservation of sacral nerve roots (n = 13), resection of otherwise inoperable disease (n = 4) and the avoidance of hindquarter amputation (n = 3). The intralesional resection rate for primary tumours of the pelvis and sacrum was 8.7% (n = 2): clear bone resection margins were achieved in all cases. At a mean follow-up of 13.1 months (3 to 34) three patients (13%) had developed a local recurrence. The mean time alive from diagnosis was 16.8 months (4 to 48). . Computer navigation-assisted surgery is safe and has reduced our intralesional resection rate for primary tumours of the pelvis and sacrum. We recommend this technique as being worthy of further consideration for this group of patients. Cite this article: Bone Joint J 2013;95-B:1417–24

Objective. To evaluate functional and oncological outcomes following resection of sacral tumours and discuss the strategies for instrumentation. Introduction. Primary malignant tumours of the sacrum are rare, arising from bony or neural elements, or bone marrow in haematological malignancies. Management of such lesions is dictated by anatomy and the behaviour of tumours. Three key issues which arise are the adequacy of tumour resection, mechanical stabilisation and the need for colostomy. Stabilisation is often extensive and can be challenging. Methods. A retrospective review of the surgical management of primary malignant sacral tumours from 2004 - 2009. Results. The study included 46 patients (34 males, 12 females) with an average age of 49 (range 7 – 82). Median duration of symptoms before presentation was 26 months. 25 patients (54%) underwent surgical resection. 8 underwent instrumented stabilisations with fibula strut graft vs. 17 uninstrumented. Mechanical failure of stabilisation was noted in 75% over the follow up period but only one required revision surgery. Colostomy was performed in 10 patients (40%). Mean follow post-operatively was 19.0 months. Wound healing problems were present in 5/25 (20%). There was no difference in infection rates between definitive surgery with and without colostomy. There was one peri-operative death. Local recurrence occurred in 12%(3/25) of operated patients although follow-up period was noted to be short. Conclusions. Mechanical stabilisation for extensive lesions in the sacrum are particularly challenging in tumour surgery. Despite radiological failure in 7/8 instrumented stabilisations, patients were relatively asymptomatic and only 1/8 required revision stabilisation surgery. Ethics approval:. None: Audit. Interest Statement: None

Aim. was to analyze infections after bone tumour surgery. Method. 1463 patients treated from 1976 to 2007 were analized: 1036 with resection and prostheses in the lower limbs, 344 with resection and prostheses in the upper limbs, 83 with surgery for sacral tumours. Infections were analyzed for time of occurrence (“postoperative” in the first 4 weeks from surgery, “early” within 6 months, and “late” after 6 months), microbic agents, treatment, outcome. Results. In lower limbs, infections occurred in 80 cases (7.7%): generally monomicrobial, caused by gram positives, postoperative in 9, early in 12, late in 59 cases. Treatment was “two stage” in 73, “one stage” in 4, primary amputation in 3. Revisions for infection were successful in 63 patients (79%), while 17 patients were amputated (21%). In upper limbs, infections occurred in 20 cases (5.8%): generally monomicrobial, caused by gram positives (88.5%), postoperative in 2 cases, early in 7, late in 11. “Two stage” treatment was attempted in all cases, but only in 3 prosthesis was re-implanted, since the cement spacer yelded similar function. No infections were observed in 28 intralesional excisions of sacral giant cell tumours. Infection occurred in 23/52 resected sacral tumours (44%) (Three patients died postoperatively were excluded from this group): postoperative in 16 cases and early in 7, caused by gram negatives in 62% and multimicrobial in 74%. Surgical debridements associated with antibiotic therapy according to coltures cured infection in all cases. Conclusion. Infection is a severe complication in orthopedic oncology. Its incidence in the extremities (7.7% and 5.8%) is lower than after sacral surgery (44%). It is influenced by chemotherapy and by the presence of foreign bodies. Infections were mostly late, monomicrobial, gram positive in extremities, while early, multimicrobial and gram negative in sacral surgery

Introduction: Benign bone-forming tumours are common in children and adolescents. Careful radiographical and histological study is necessary to distinguish slow growing from more aggressive bone forming tumours. We reviewed 25 cases of primary benign bone forming tumours of the spine to investigate whether there were any obvious differences in their biological behaviour in adults compared to children. Materials and Methods: Twenty five cases of primary benign bone forming tumours of the spine were identified from the Scottish Bone Tumour Registry: this data is collected prospectively. A retrospective review of this data was performed. There were 9 osteoid osteomas, 15 osteoblastomas and 1 aggressive osteoblastoma. These cases were divided into group A (children) and group B (adults). Results: There were 16 patients in group A (6-osteoid osteoma, 9-osteoblastoma, 1-aggressive osteoblastoma), 10 boys and 6 girls. The mean age was 12.1 years (range, 6–16 years). There were 2 cervical, 4 thoracic, 8 lumbar and 2 sacral tumours. There were 9 patients in Group B (3-osteoid osteoma, 6-osteoblastoma), 7 boys and 2 girls. The mean age was 26.6 years (range, 18–53 years). There were 1 cervical, 6 thoracic, 2 lumbar and none sacral tumours. Twenty two tumours were excised and 3 had curettage performed (1 child and 2 adults). There were 2 recurrences (one osteoid osteoma, one osteoblastoma), one from the excision group and one who had curettage, both in adults. These were successfully treated with re-excision. Mean follow-up was 8 years and all were alive at the time of final follow-up. Conclusions: Benign bone forming tumours of the spine are extremely uncommon. In children they occur more commonly in lumbar spine, while thoracic involvement predominates in adult patients. Good outcomes are obtained with surgical treatment. Recurrence occurred only in the adult group: both of these patients had successful outcomes following further treatment

Introduction: Benign bone-forming tumours are common in children and adolescents. Careful radiographical and histological study is necessary to distinguish slow growing from more aggressive bone forming tumours. We reviewed 25 cases of primary benign bone forming tumours of the spine to investigate whether there were any obvious differences in the biological behaviour of such tumours in adults compared to children. Materials and Methods: Twenty five cases of primary benign bone forming tumours of the spine were identified from the Scottish Bone Tumour Registry: this data is collected prospectively. A retrospective review of this data was performed. There were 9 osteoid osteomas,15 osteoblastomas and 1 aggressive osteoblastoma. These cases were divided into group A (children) and group B (adults). Results: There were 16 patients in group A (6-osteoid osteoma, 9-osteoblastoma, 1-aggressive osteoblastoma), 10 boys and 6 girls. The mean age was 12.1 years (range, 6–16 years). There were 2 cervical, 4 thoracic, 8 lumbar and 2 sacral tumours. There were 9 patients in Group B (3-osteoid osteoma, 6-osteoblastoma), 7 boys and 2 girls. The mean age was 26.6 years (range, 18–53 years). There were 1 cervical, 6 thoracic, 2 lumbar and none sacral tumours. Twenty two tumours were excised and 3 had curettage performed (1 child and 2 adults). There were 2 recurrences (one osteoid osteoma, one osteoblastoma), one from the excision group and one who had curettage, both in adults. These were successfully treated with re-excision. Mean follow-up was 8 years and all were alive at the time of final follow-up. Conclusions: Benign bone forming tumours of the spine are extremely uncommon. In children they occur more commonly in lumbar spine, while thoracic involvement predominates in adult patients. Good outcomes are obtained with surgical treatment. Recurrence occurred only in the adult group: both of these patients had successful outcomes following further treatment

Sacral tumours are rare and can present difficult diagnostic and therapeutic challenges even at an early diagnosis. Surgical resection margins have a reported prognostic role in local recurrence and improved survival. Successful management is achieved within a specialist multidisciplinary service and involves combination chemotherapy, radiotherapy and surgery. We present our experience of patients with sacral tumours referred to our unit, who underwent total and subtotal sacrectomy procedures. Materials and Methods. Between 1995 and 2010, we identified twenty-six patients who underwent a total or subtotal sacrectomy operation. Patients were referred from around the United Kingdom to our services. We reviewed all case notes, operative records, radiological investigations and histopathology, resection margins, post operative complications, functional outcomes and we recorded long-term survival outcomes. Patients who were discharged to local services for continued follow up or further oncological treatment were identified and information was obtained from their general practitioner or oncologist. We reviewed the literature available on total sacrectomy case series, functional outcomes and soft tissue reconstruction. Results. We reviewed 26 patients, 16 male and 10 female, with a mean age at presentation of 53.4 years (range 11–80 years). Duration of symptoms ranged from 2 weeks to 6 years; lower back pain and sciatica were amongst the most common presenting features. Histological diagnoses included chordoma, Ewing's, malignant peripheral nerve sheath tumour, chondromyxoid fibroma, spindle cell sarcoma, synovial sarcoma, chondrosarcoma. A combined approach was used in two-thirds of patients and most of these patients had a soft tissue reconstruction with pedicled vertical rectus myocutaneous flap. Complications were categorised into major and minor and subdivided into wound, bladder and bowel symptoms. Wound complications and need for further intervention were more common amongst the patient group who did not have simultaneous soft tissue reconstruction at operation. All patients had a degree of bladder dysfunction in the early postoperative period. We present survivorship curves including recurrence and development of metastases. Conclusion. Total sacrectomy procedures carry a high risk of associated morbidity but can improve survival amongst specific groups of patients. They present challenges in diagnosis and management, but must be referred to a specialist service, that will instigate appropriate investigations and treatment regimes within a multidisciplinary setting. The expansion of services from other specialties required for the postoperative and ongoing rehabilitation plays an important role in overall management and appropriate pathways to coordinate these services are necessary

Purpose: Aim of this study was to analyse the incidence of infection in orthopaedic oncology after major surgical procedures for bone tumors. Materials and Methods: We included patients with primary sacral tumors treated by major surgical procedure and patients with bone tumors of the upper and lower limb treated by resection and prosthetic reconstruction. Demographic data, surgery, adjuvant treatments, type of reconstruction were analyzed. Special attention was given to the infection: incidence, classification, microbic agents, treatment and outcome. Infections in the first 4 weeks were considered “postoperative”, those in the first 6 months were judged “early”, while “late” those diagnosed after 6 months. Overall 1462 patients treated in one institution from 1076 to 2007. Were considered 1036 patients with tumors of the lower limb, 344 patients with tumors of the upper limb and 82 sacral tumors. Univariate analysis with Kaplan-Meier actuarial curves was used in evaluating risk factors and implant survival to infections. Results: In the lower limb, infection occurred in 80 cases (7.7%). Most frequent bacteria were gram positive. Infection was postoperative in 9 cases, early in 12, late in 59 cases and generally monomicrobial. Surgical treatment was “two stage” in 73 patients, “one stage” in 4 and primary amputation in 3 cases. Revisions for infection were successful in 63 pts (79%), while 17 pts were amputated (21%). In the upper limb, in 20 patients (5.8%) a revision for deep infection was required. Two infections were postoperative, 7 early and 11 late. S. Epidermidis and S. Aureo were the most frequent bacteria causing infection (45%). “Two stage” treatment of infection was performed, but a new prostheses was implanted in 3 cases. In 17 the spacer was never removed. In the sacrum, no deep infections were observed after intralesional excision for giant cell tumors. In 23/52 resections (44%) for chordoma (3 pts. died postoperatively and were excluded), infection occurred: in 16 patients postoperatively, in 7 within 6 months. Bacteria causing infection were mostly gram negative: in 74% of cases infection was multiagent. Surgical treatment consisted in one or more surgical debridements with antibiotics therapy according to coltures: infection healed in all cases. Conclusion: Infection is a severe complication in prosthetic reconstructions for tumors of the upper and lower limb. Its incidence in the extremities (7.7% and 5.8%) is lower than after sacral surgery (44%). Infections are mostly late, monomicrobial and caused by gram positive in extremities, while early, multimicrobial and caused by gram negative in the sacrum

Background: Sacral tumours are commonly diagnosed late and therefore are often large and at an advanced stage before treatment is instituted. The late presentation means that curative surgical excision is technically demanding. 1. Total en-bloc sacrectomy is fraught with potential complications: deep infection, substantial blood loss, large bone and soft tissue defects, bladder, bowel and sexual dysfunction, spinal-pelvic non-union, and gait disturbance. 2. The aim of the current study was two-fold: firstly to detail the technique used by the senior author and chronicle how this has evolved; and secondly to present the complications and outcome of nine total en bloc sacrectomies. Methods: We retrospectively analysed of total en-bloc sacrectomies between 1991 and 2004. Nine patients (2M, 7F, mean age at surgery 39 years, range 21 – 64yrs) with a diagnosis of primary sacral tumour underwent total en-bloc sacrectomy under the care of the senior author. The mean follow-up was 50.2 months (range: 3.5 – 161 mths). Patients’ functional outcome was evaluated using the Functional Independence Measure (FIM) instrument and the SF-36. Intra-operative and postoperative complications (including disease progression) were documented. Results: Surgical technique has evolved from single stage surgery without and with colostomy to two stage surgery with colostomy. Currently, the first stage includes an anterior lumbar interbody fusion at L4/L5 retaining the L5 nerve roots. In the second stage an L4 to pelvic fusion is performed posteriorally. The dura is tied and divided just below the L5 roots. The mean total operating time was 13.3 hrs (range: 8 – 20.1hrs); the mean total blood loss 14.1 ltrs (range: 4.2 – 33 ltrs). There were two revision L4 to pelvic fusions for pseudoarthroses. The mean length of hospital stay was 8.9mths (range: 2 – 36mths). One patient had a recurrence and died 2 years after her surgery. Of the surviving 8 patients the results from the functional outcome scores were variable. Three patients are able to walk independently; the remaining 5 are all mobile but require differing degrees of assistance to walk. Conclusion: Total en bloc sacrectomy is a major surgical undertaking but our series has shown that it is probably justified in view of the fact that 8 out of 9 patients have had no tumour recurrence and all are able to walk

1. Five cases of involvement of vertebrae by growths classified as giant-cell tumours, and two cases of involvement by tumours classified as aneurysmal bone cysts are described. 2. The periods of observation after operation in the benign cases were in three cases six years, in one ten years and in one twenty-one years. 3. In one case malignant transformation developed four and a half years after operation and one patient, in whom a sacral tumour was already malignant at the time of operation, died five months later. 4. Four patients showed significant involvement of vertebral bodies. 5. The problems related to the removal of a vertebral body and the measures taken to stabilise the spine are discussed

Introduction. Although various reports analyzed “en-bloc” excision of sacral tumors, there are still technical problems to improve protection of nerve roots, preserve surrounding structures and reduce intraoperative bleeding, maintaining the oncologic result. We present a new technique for sacral resection, with short term preliminary results, derived with modification from Osaka technique. Methods. Seven patients were resected for their sacrococcygeal chordoma with the followed described technique. Two patients had previous surgery elsewhere. The sacrum is exposed by a posterior midline incision and complete soft-tissue dissection. Lateral osteotomies were performed through the sacral foramina using a threadwire saw and Kerrison rongeurs, to avoid sacral roots damage. After proximal osteotomy, the sacrum is laterally elevated and mobilized to allow dissection of presacral structures. Mean surgical time was 5 hours (range: 3 to 8). Mean blood loss was 3640 ml. Results. Level of resection was S1 in 2 pts, S2 in 4 pts, S3 in 1. Margins were wide in 6 patients and marginal in one. At a mean follow-up of 2 years, six patients were disease-free, one had a local recurrence. No complications were showed. Conclusion. This technique allows wide margins with roots preservation and reduction of complications and operative time. Indications for posterior approach only can be extended to resection proximal to S3, when there is minimal pelvic invasion and none or partial involvement of sacroiliac joints. However, the long term benefits of this technique need to be evaluated

Objective. To evaluate functional and oncological outcomes following sacral resection. Methods. Retrospective review of 97 sacral tumours referred to spinal or oncology units between 2004 and 2009. Results. 61 males, 37 females (average age of 47 (range 3 – 82). Average duration of symptoms 13 months. 17 metastatic disease, excluded from further discussion. Of the remainder 36/81(44%) underwent surgery – 21 excision, 9 excision and instrumented stabilisation, and 6 curettage. 13(16%) patients were inoperable - 8 advanced disease, 3 unable to establish local control, 2 recurrence. Colostomy was performed in 11/21(52%) patients who underwent excision. Deep wound infections in 6/21(29%). No difference in infection rates between definitive surgery with or without colostomy – 3/11(27%) vs. 3/10(30%). In the instrumented group, no colostomies were performed due to concerns about deep infection and none resulted (0/9). Radiological failure of stabilisation was noted in 7/9(78%). However, functionally, 3/9(33%) were mobilising independently, 3/9(33%) crutches, 2/9(22%) able to transfer and 1/9(11%) undocumented. Mean follow-up 25 months (range 0-70). Local recurrence in 9/36(25%) of operated patients. Metastasis occurred in 4/36(11%) and mortality 8/36(22%) although follow-up period was noted to be short. Conclusions. Results are comparable with current literature. Mechanical stabilisation for extensive sacral lesions is challenging. Despite radiological failure in 7/9 instrumented stabilisations, patients were relatively asymptomatic and only 1/9 required revision stabilisation surgery. By design none had colostomies and there were no deep infections

To evaluate functional and oncological outcomes following resection of primary malignant bone tumours. Primary malignant tumours of the sacrum are rare, arising from bony or neural elements, or bone marrow in haematological malignancies. Management of these lesions is dictated by anatomical considerations and the behaviour of tumours. The three key issues which arise are the adequacy of tumour resection, mechanical stabilisation and the need for colostomy. A retrospective review of the surgical management of primary malignant sacral tumours from 2004 - 2009. The study included 46 patients (34 males, 12 females) with an average age of 49 (range 7 – 82). Median duration of symptoms before presentation was 26 months. 10 patients had inoperable tumours at presentation. 6 patients had chemotherapy. 2 patients opted for palliative radiotherapy. 1 patient was unfit for surgery. 25 patients (54%) underwent surgical resection. 8 underwent instrumented stabilisations with fibula strut graft vs. 17 uninstrumented. Colostomy was performed in 10 patients (40%). Mean follow post-operatively was 19.0 months. Wound healing problems were present in 5/25 (20%). There was no difference in infection rates between definitive surgery with and without colostomy. Mechanical failure of stabilisation was noted in 75%. There was one peri-operative death. Local recurrence occurred in 12%(3/25) of operated patients although follow-up period was noted to be short. Mechanical stabilisation for extensive lesions in the sacrum are particularly challenging in tumour surgery. Despite radiological failure in 7/8 instrumented stabilisations, patients were relatively asymptomatic and only 1/8 required revision stabilisation surgery. Ethics approval: None: Audit Interest Statement: None

Resecting bone tumours within the pelvis is highly challenging and requires good cutting accuracy to achieve sufficient margins. Computer-assisted technologies such as intraoperative navigation have been developed for pelvic bone tumour resection. Patient-specific instruments have been transposed to tumour surgery. The present study reports a series of 11 clinical cases of PSI-assisted bone tumour surgery within the pelvis, and assesses how accurately a preoperative resection strategy can be replicated intraoperatively with the PSI. The patient series consisted in 11 patients eligible for curative surgical resection of primary bone tumor of the pelvis. Eight patients had a bone sarcoma of iliac bone involving the acetabulum, two patients had a sacral tumor, and one patient had a chondrosarcoma of proximal femur with intra-articular hip extension. Resection planning was preoperatively defined including a safe margin defined by the surgeon from 3 up to 15 mm. PSI were designed using a computer-aided design software according to the desired resection strategy and produced by additive manufacturing technology. Intraoperatively, PSI were positioned freehand by the surgeon and fixed on the bone surface using K-wires. The standard surgical approach has been used for each patient. Dissection was in accordance with the routine technique. There was no additional bone exposure to position the PSI. Histopathological analysis of the resected tumor specimens was performed to evaluate the achieved resection margins. Postoperative CT were acquired and matched to the preoperative CT to assess the local control of the tumor. Two parameters were measured: achieved resection margin (minimum distance to the tumor) and location accuracy (maximum distance between achieved and planned cuttings; ISO1101 standard). PSI were quick and easy to use with a positioning onto the bone surface in less than 5 minutes for all cases. The positioning of the PSI was considered unambiguous for all patients. Histopathological analysis classified all achieved resection margins as R0 (tumor-free), except for two patients : R2 because of a morcelised tumour and R1 in soft tissues. The errors in safe margin averaged −0.8 mm (95% CI: −1.8 mm to 0.1 mm). The location accuracy of the achieved cut planes with respect to the desired cut planes averaged 2.5 mm (95% CI: 1.8 to 3.2 mm). Results in terms of safe margin or the location accuracy demonstrated how PSI enabled the surgeon to intraoperatively replicate the resection strategies with a very good cutting accuracy. These findings are consistent with the levels of bone-cutting accuracy published in the literature. PSI technology described in this study achieved clear bone margins for all patients. Longer follow-up period is required but it appears that PSI has the potential to provide clinically acceptable margins