We present the indications and outcomes of a series of custom 3D printed titanium acetabular implants used over a 9 year period at our institution (Sydney, Australia), in the setting of revision total hip arthroplasty. Individualised image-based case planning with additive manufacturing of pelvic components was combined with screw fixation and off-the-shelf femoral components to treat patients presenting with failed hip arthroplasty involving acetabular bone loss. Retrospective chart review was performed on the practices of three contributing surgeons, with an initial search by item number of the Medicare Benefits Scheme linked to a case list maintained by the manufacturer. An analysis of indications, patient demographics and clinical outcome was performed. The cohort comprised 65.2% female with a median age of 70 years (interquartile range 61–77) and a median follow up of 32.9 months (IQR 13.1 - 49.7). The indications for surgery were infection (12.5%); aseptic loosening (78.1%) and fracture (9.4%), with 65.7% of cases undergoing previous revision hip arthroplasty. A tumour prosthesis was implanted into the proximal femur in 21.9% of cases. Complications were observed in 31.3% of cases, with four cases requiring revision procedures and no deaths reported in this series. Kaplan-Meier analysis of all-cause revision revealed an overall procedure survival of 88.7% at two years (95%confidence interval 69 - 96.2) and 83.8% (95%CI 62 - 93.7) at five years, with pelvic implant-specific survival of 98% (95%CI 86.6 - 99.7) at two and five year follow up. We conclude that an individualised planning approach for custom 3D printed titanium acetabular implants can provide high overall and implant-specific survival at up to five years follow up in complex cases of failed hip arthroplasty and acetabular bone loss.
PVNS or TGCT (Pigmented Villonodular Synovitis, or Tenosynovial Giant Cell tumour) is a benign tumour affecting the synovial lining of joints and tendon sheaths, historically treated with surgical excision or debridement. We have shown previously this management is fraught with high recurrence rates, especially in its diffuse form. We present the encouraging early results of medical management for this condition with use of a CSF1 inhibitor, in comparison to a cohort of 137 cases previously treated at our institution.
Extracorporeal irradiation of resected bone segments has been used for pelvic reconstruction for 12 years in our unit. The technique allows for a perfect fit, preservation of muscle attachments, and thus, facilitating reconstruction, more rapid osteotomy of autograft bone, low cost, and a low infection rate. Of particular interest is its use in children; revascularisation appears more complete with irradiated autograft, as compared to allograft. There is sparing of adjacent growth plates if the irradiation is given outside the body, whereas external beam radiation would destroy the proximal femoral growth plate—leading to significant leg length discrepancy. Avoiding external beam irradiation also removes any risk of late radiation induced sarcoma and removes the late effects of soft tissue fibrosis due to external beam irradiation. Twenty-seven pelvic reconstructions have been done over a 12-year period, with three failures due to infection and seven due to further disease. Four of these have been for de-differentiated chondrosarcoma of the pelvis, where local recurrence led to failure. In the presence of de-differentiated pelvic chondrosarcoma, we do not recommend this form of reconstruction. Long term functional outcome scores for the first 50 cases completed between August 1996 and June 2003 gave a TESS score of 82% and MSTS score of 78%. This is more than comparable to published series using other forms of reconstruction.
Prior to the 1970s, almost all bone sarcomas were treated by amputation. The first distal femoral resection and reconstruction was performed in 1973 by Dr Kenneth C Francis at the Memorial Sloan-Kettering Cancer Centre in New York. Since that time, limb-sparing surgery for primary sarcoma has become the mainstay of sarcoma surgery throughout the world. Initially, the use of mega-prostheses of increasing complexity, involving all the major long bones and both pelvic and shoulder girdles, was popularised. In the early 1980s, wide use of massive allograft reconstructions became widespread in both Europe and in multiple centres in the USA and UK. Since that time, increasing complexity in the design of prostheses has allowed for increasing functional reconstructions to occur, but the use of allograft has become less popular due to the development of late graft failures of patients survive past ten years. Fracture rates approaching 50% at 10 years are reported, and thus, other forms of reconstruction are being sought. Techniques of leg lengthening, and bone docking procedures to replace segmental bone loss to tumour are now employed, but the use of biological vascularised reconstructions are becoming more common as patient survivorship increases with children surviving their disease. The use of vascularised fibular graft, composite grafts and re-implantation of extra-corporeally irradiated bone segments are becoming more popular. The improvement in survivorship brought about the use of chemotherapy is producing a population of patients with at least a 65% ten year survivorship, and as many of these patients are children, limb salvage procedures have to survive for many decades. The use of growing prostheses for children have been available for some 25 years, first commencing in Stanmore, UK, with mechanical lengthening prostheses. Non-invasive electro-magnetic induction coil mechanisms are now available to produce leg lengthening, with out the need for open surgery. Whilst many of these techniques have great success, the area of soft tissue attachment to metallic prostheses has not been solved, and reattachment of muscles is of great importance, of course, for return of function. There are great problems in the shoulder joints where sacrifice of rotator cuff muscles is necessary in obtaining adequate disease clearance at the time of primary resection, and a stable shoulder construct, with good movement, has yet to emerge. Similar areas of great difficultly remain the peri-acetabular and sacro-iliac resections in the pelvis. Perhaps the real future of the art of limb salvage will be in the reconstruction of failed major joint replacements where there is great loss of bone stock, and already massive tumour prostheses are providing a salvage pathway for failed standard joint replacement. The final future for limb salvage, however, may not rest with increasing surgical complexity and innovation, but with the development of molecular biology and specific targeted treatments, according to the cytogenetics of a particular tumour. We are on the threshold of yet another quantum change in the approach to cancer management; just as chemotherapy brought a tremendous change in the 1970s, molecular biology is the frontier to make much of the current limb salvage surgery that is performed redundant.
To review the first 50 cases, looking at survivorship of the irradiated autograft, complications and functional outcomes in a wide range of bony malignancies and anatomical locations. 50 patients underwent en-bloc resection, extracorporeal irradiation with 50 Gy, and re-implantation for limb salvage between August 1996 and June 2003. Case notes and patients were reviewed.Aim
Methods
This study reviews the implantation of extracorporally irradiated autografts as a treatment modality and alternative for pelvic Ewing’s Sarcoma. We identified 13 cases between 1994 and 2004 (7 male, 6 female), with mean age 14 years (6.5–34.5). The disease free survival was 69% overall, (75% excluding one case initially treated elsewhere) with a mean follow-up of 6.1 years (3.1 – 8.2). Four patients died with distant metastases at a mean time of 17 months (13–23). Functional results showed a median MST-Score of 86% (IQR 68.5 to 91.5), a median TES-Score 85% (IQR78.5 to 93.5) and a median Harris Hip-Score 89% (IQR 82.5 to 96.5). Solid bony union was observed at all osteotomy sites. Consolidation was achieved after median 6 months (IQR 5 to 7). There were three complications (23%) which required operative intervention, one (8%) due to infection, which required removal of the autograft. Advantages with this technique include ideal fit in the defect and thus promotes healing through greater contact at osteotomy junctions. It avoids early and late loosening and/or breakage of a prosthesis. It acts as a biological bridge for creeping substitution and bony incorporation in the defect. It allows re-attachment of tendons and ligaments, and thus preserves anatomic relationships. There is no risk of disease transmission or immunological reactions. It is cost effective and convenient in any institution with radiotherapeutic equipment. We conclude this is an appropriate treatment option for localised and resectable pelvic Ewing Sarcoma.
We have treated 50 patients with bony malignancy by en bloc resection, extracorporeal irradiation (ECI) with 50Gy and re-implantation of the bone segment as a method of limb salvage. Mean survivor follow-up is 38 months (12–92). 42 patients remain alive without disease. 4 recurrences occurred. Functional results were generally good: Mankin grades 17 excellent, 13 good, 9 fair, 3 failures; MSTS mean 77 (20–100); TESS mean 81 (40–100). Solid bony union was the norm, however bone resorption was seen in some cases. The dose of radiation is theoretically lethal to all cells and produces a dead autogenous bone graft of perfect fit. ECI is a useful technique of limb salvage where there is a reasonable residual bone stock. It allows effective re-attachment of muscle tendons, and produces a lasting biological reconstruction. The risk from the re-implanted bone of both local recurrence and of late radiotherapy induced malignancy should be nil.
We have used extracorporeal irradiation as part of the treatment of primary bone tumours since 1996. It is a technique that preserves bone stock, with no allograft cost, is tailor made for the individual and can protect the epiphyseal plates in the immature skeleton. All cases are biopsied, staged and if appropriate undergo pre-operative chemotherapy. The resected specimen is wrapped in sterile drapes, sealed and then irradiated in either the linear accelerator or a blood product irradiator. The mid-plane dose delivered to the specimens was 50 Gy. The specimen is then reimplanted using varied methods. Post-operative chemotherapy is given if indicated, and the patients have 6 weeks of antibiotics. Regular review is undertaken in the outpatients. We individually reviewed all the patients, examined them and scored their functional results according to the Mankin and Enneking Systems. The pelvic/proximal femur patients also had a Harris Hip Score recorded. There were 31 cases all over 6 months from surgery with an average follow up of 24 months. Mean age at diagnosis was 24.9 years (range 3 to 66), in 15 males and 16 females. Pathology included 10 osteosarcomas, 13 Ewing’s and 8 chondrosarcomas. Affected bones were 4 proximal humeri, 14 hemipelvises, 12 femurs and 1 tibia. Reconstruction varied from autograft alone, to autograft with a prosthesis, intramedullary nail or blade plate. 10 patients had supplementary vascularized fibula grafts and 2 pedicle flaps. There have been 4 deaths of disease, 2 alive with disease and 25 currently disease free. The Enneking scores averaged 70%, the Harris Hip Scores averaged 74 in the pelvic reconstructions and 92 in the proximal femurs.
Chordoma is low grade, locally aggressive and mainly in the sacrococcygeal region. Treatment is a combination of surgery and radiotherapy. We reviewed, to determine our outcome and functional deficits, the cases treated over 15 years by the senior author. Out of 26 chordoma’s referred 14 were in the sacrococcygeal region. We reviewed them retrospectively looking at presentation, diagnosis, surgical approach, neurological result, complications and survival. The mean age was 55 years (range 26–80 years), 9 males and 5 females. 13 were primary and 1 was recurrent. Patients reported 18 months of symptoms prior to diagnosis. The tumour sites were S1-5, S2-2, S3-2, S4-3, S5-1 and coccyx −1. Surgery was performed via an anterior/posterior-combined approach in 10, a posterior approach in 2, anterior in 1 and posterior/perineal combined in 1. Complete excision was possible in 11 cases. Surgical resection with radiotherapy was used for inadequate surgical margins, in 3 cases. Neurologically we found that we needed an intact unilateral S3 nerve root for continence in our series. All patients had minor wound complications, 2 wounds required further surgical intervention, and there were 2 cardiac arrhythmias, 1 pulmonary embolus. There were 5 recurrences, 3 were local and 2 metastatic. The survival data for 5 and 7 years is 88% and 71% respectively. Our disease free survival at 5 and 7-years was 44% and 57% respectively. We achieved an excellent 5 and 7-year survival in our series. The results following complete excision were best, but those treated with adjuvant radiotherapy also responded well. We saw that a solitary S3 nerve root is needed for continence. Treating by a combined anterior/ posterior approach suggests improved survival.