Treatment of spinal metastatic disease has evolved with the advent of advanced interventional, surgical and radiation techniques. Spinal Oligometastatic disease is a low volume disease state where en bloc resection of the tumour, based on oncological principles, can achieve maximum local control (MLC). Hybrid therapy incorporating Separation surgery (>2mm clearance of the thecal sac) and Stereotactic Ablative Radiotherapy (SABR) offer an alternative approach to achieving MLC. Hybrid therapy is also a viable option in patients eligible for SBRT who have failed conventional radiation therapy. En-bloc surgery may be a suitable option for those patients who are ineligible for or have failed SBRT. A multidisciplinary approach is particularly important in the decision-making process for these patients. Metal free instrumentation is aiding the optimization of these surgeries. The authors present a supra-regional centre's experience in managing spinal oligometastases. Retrospective review of oligometastatic spinal disease at a supra-regional centre between 2017 and 2021. Demographics, operative course, complications and Instrument type are examined.Introduction
Methods
Tomita En-bloc spondylectomy (TES) of L5 is one of the most challenging spinal surgical techniques. A 42-year-old female was referred with low back pain and L5 radiculopathy with background of right shoulder excision of liposarcoma. CT-PET confirmed a solitary L5 oligometastasis. MRI showed thecal sac indentation and therefore was not suitable for stereotactic ablative radiotherapy (SABR) alone. First Stage: Carbon fibre pedicle screws were planned from L2 to S2AI-Pelvis, aligned to her patient-specific rods. Custom 3D-printed navigation guides were used to overcome challenging limitations of carbon instruments. Radiofrequency ablation (RFA) of L5 pedicles prior to osteotomy was performed to prevent sarcoma cell seeding. Microscope-assisted thecal sac-tumour separation and L5 nerve root dissection was performed. Novel surgical navigation of the ultrasonic bone cutter assisted inferior L4 and superior S1 endplate osteotomies. Second stage: We performed a vascular-assisted retroperitoneal approach to L4-S1 with protection of the great vessels. Completion of osteotomies at L4 and S1 to en-bloc L5: (L4 inferior endplate, L4/5 disc, L5 body, L5/S1 disc and S1 superior endplate). Anterior reconstruction used an expandable PEEK cage obviating the need for a third posterior stage. Reinforced with a patient-specific carbon plate L4-S1 promontory. Sacrifice of left L5 nerve root undertaken.Introduction
Planning Methodology
Carbon fibre (CF) instrumentation is known to be radiolucent and has a tensile strength similar to metal. A specific use could be primary or oligometastatic cancer where regular surveillance imaging and Stereotactic Radiotherapy are required. CT images are inherently more prone to artefacts which affect Hounsfield unit (HU) measurements. Titanium (Ti) screws scatter more artefacts. Until now it has been difficult to quantify how advantageous the radiolucency of carbon fibre pedicle screws compared to titanium or metallic screws actually is. In this retrospective study, conducted on patients from 2018 to 2020 in SGH, we measured the HU to compare the artifact produced by CF versus Ti pedicle screws and rods implanted in age and sex matched group of patients with oligometastatic spinal disease.Background
Methodology
Treatment of periprosthetic joint infection (PJI) can include local delivery of antibiotics. A frequently used medium is absorbable calcium sulphate beads. The aims of this study were to:
identify how often organisms in infected THRs are sensitive to the added antibiotics establish the incidence of persistent wound discharge and hypercalcaemia All patients who received an antibiotic loaded calcium sulphate carrier (Stimulan, Biocomposites, Keele, UK) for either confirmed infection, presumed infection or for prophylaxis between July 2015 and July 2020 were included. Stimulan use was at the discretion of the surgeon, and between 10 and 40cc was used. In the absence of a known organism we routinely used 1g vancomycin and 240mg gentamicin per 10 cc of calcium sulphate. Post-operative sensitivities for all organisms cultured were compared to the antibiotics delivered locally. Persistent wound drainage was defined as discharge beyond the third postoperative day. Patients had serum calcium measured if they developed symptoms consistent with hypercalcaemia (Ca >2.6 mmol/L) or the clinical team felt they were at high risk. 189 patients (mean age 66.9 years, mean BMI 28.9, 85 male, 104 female) were included. 11 patients had a native joint septic arthritis, 42 presented with acute PJI and 136 presented with chronic PJI. 133 patients grew an organism, of which 126 were sensitive to the added antibiotics. Of the seven patients with resistant growth five had vancomycin-resistent Enterococcus, one Pseudomonas and one multi-organism growth including coagulase negative Staphylococcus. 40 patients experienced persistent wound discharge, with eight requiring re-operation. All other cases settled with dressing management. 12 patients developed hypercalcaemia (3/64 10cc, 7/117 20cc, 0/2 30cc and 2/6 40cc). The peak calcium reading ranged between the second and twelfth post-operative day. The addition of vancomycin and gentamicin to absorbable calcium sulphate covers the majority of organisms found in culture positive infection in our cohort. It also appears safe, with an acceptable incidence of hypercalcaemia or wound discharge. Further work is required to identify patients at greatest risk of culturing resistant organisms or delayed wound healing.
Antibiotic loaded absorbable calcium sulphate beads (ALCSB) are an increasingly popular adjunct in the treatment of musculoskeletal infections including osteomyelitis and peri-prosthetic joint infections (PJI). Limited data exist regarding the clinical indications and biochemical outcomes of ALCSB in PJI cases. To determine the proportion of organisms that were sensitive to the gentamicin and vancomycin that we add to the ALCSB as a part of our treatment protocol and to determine the prevalence of postoperative hypercalcaemia when used for treatment of hip and knee DAIR (debridement and implant retention) and revision arthroplasty for PJI.Introduction
Aims
The Medicines and Healthcare Products Regulatory Agency (MHRA) of the UK have published guidelines for annual follow up of patients with metal on metal hip replacements following widespread concern regarding metallosis We followed up 718 total hip replacements (594 stemmed hips and 124 resurfacing) with metal on metal bearing, implanted between April 1999 and August 2010 in dedicated clinics with clinical and radiological assessment along with assessment of serum metal ions. Survival was calculated using Kaplan Meier analysis.Introduction
Methods
Evidence-based practice advocates utilising best current research evidence, while reflecting patient preference and clinical expertise in decision making. Successfully incorporating this evidence into practice is a complex process. Based on recommendations of existing guidelines and systematic evidence reviews conducted using the GRADE approach, treatment pathways for common spinal pain disorders were developed. The aim of this study was to identify important potential facilitators to the integration of these pathways into routine clinical practice.Background
Aims
Large studies have reported high dislocation rates (7 to 24%) following revision total hip arthroplasty (THA), particularly when the revision is undertaken in the presence of pre-existing instability. We retrospectively reviewed the clinical and radiographic outcome of 155 consecutive revision THA's that had been performed using an unconstrained dual-mobility acetabular implant. It features a mobile polyethylene liner articulating with both the prosthesis head and a metal acetabular cup, such that the liner acts as the femoral head in extreme positions. It can be implanted in either a press fit or cemented manner. Mean follow-up was 40 months (18–66) and average age 77 (42–89). Uncemented (n=122) and cemented (n=33) implants with a reinforcing cage, were used. Indications were aseptic loosening (n=113), recurrent instability (n=29), periprosthetic fracture (n=11) and sepsis (n=2). Three of the 155 cases (1.9%) dislocated within 6 weeks of surgery and were successfully managed with closed reduction. The 3 dislocations occurred in the groups revised for recurrent dislocation and periprosthetic fracture. There were no cases of recurrent dislocation and no revisions for implant failure. Despite a pantheon of options available, post-operative dislocation remains a challenge especially in patients with risk factors for instability. The use of large diameter heads is proven to improve stability but there are concerns regarding wear rates, metal toxicity and recurrent dislocation in the presence of abductor dysfunction. With constrained liners there are concerns regarding device failure and aseptic loosening due to implant overload. Our dislocation rates of 1.9% and survivorship to date compare favourably with alternative techniques and are also in line with studies from France using implants of a similar design. In our hands, where there are risk factors for dislocation, the use of a dual-mobility implant has been very effective at both restoring and maintaining stability in patients undergoing revision THA.
Total hip arthroplasty is well established as a successful treatment modality for end stage arthritis, with a variety of components currently available. However, utilising traditional stemmed implants in patients with distorted proximal femoral geometry can be technically challenging with increased risk of complications. We present seven patients with distorted proximal femoral anatomy or failed hip arthroplasty in whom a technically challenging primary or revision operation was simplified by use of a Proxima stem. This is a short, stemless, metaphyseal loading implant with a pronounced lateral flare. At twelve months follow up there have been no complications with average improvement in Oxford and Harris scores of forty and forty-nine respectively. Radiological analysis shows all stems to be stable and well fixed. Designed primarily as a bone conserving implant for primary hip arthroplasty we propose that the Proxima prosthesis also be considered in cases where a conventional stemmed implant may not be suitable due to challenging proximal femoral anatomy. The use of the stemless Proxima implant provided a simple solution in seven difficult and potentially lengthy complex primary and revision hip arthroplasties with gratifying clinical and radiological outcomes.
