Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty, particularly for low volume surgeons. The recent introduction of robotic-arm assisted systems has allowed for increased accuracy, however new systems typically have learning curves. The objective of this study was to determine the learning curve of a robotic-arm assisted system for UKA.

Methods A total of 152 consecutive robotic-arm assisted primary medial UKA were performed by five surgeons between 2017 and 2021. Operative times, implant positioning, reoperations and patient-reported outcome measures (PROMS; Oxford Knee Score, EuroQol-5D, and Forgotten Joint Score) were recorded.

There was a learning curve of 11 cases with the system that was associated with increased operative time (13 minutes, p<0.01) and improved insert sizing over time (p=0.03). There was no difference in implant survival (98.2%) between learning and proficiency phases (p = 0.15), and no difference in survivorship between ‘high’ and ‘low’ usage surgeons (p = 0.23) at 36 months. There were no differences in PROMS related to the learning curve. This suggested that the learning curve did not lead to early adverse effects in this patient cohort.

The introduction of a robotic-arm assisted UKA system led to learning curves for operative time and implant sizing, but there was no effect on patient outcomes at early follow- up. The short learning curve was independent of UKA usage and indicated that robotic-arm assisted UKA may be particularly useful for low-usage surgeons.

Background. Intraoperative blood loss is a known potential complication of total knee arthroplasty (TKA). Tranexamic acid (TXA) has been shown to reduce intraoperative blood loss and postoperative transfusion in patients undergoing TKA. While there are numerous studies demonstrating the efficacy of intravenous and topical TXA in patients undergoing TKA, there are comparatively few demonstrating the effectiveness and appropriate dosing recommendations of oral formulations. Methods. A retrospective cohort study of 2230 TKA procedures at a single institution identified 3 treatment cohorts: patients undergoing TKA without the use of TXA (no-OTA, n=968), patients undergoing TKA with administration of a single-dose of oral TXA (single-dose OTA, n=164), and patients undergoing TKR with administration of preoperative and postoperative oral TXA (two-dose OTA, n=1098). The primary outcome was transfusion rate. Secondary outcomes included maximum postoperative decline in hemoglobin, number of blood units transfused, length of hospital stay, total drain output, cell salvage volume, and operating room time. Results. Transfusion rates decreased from 24.1% in the no-OTA group to 13.6% in the single-dose OTA group (p<0.001) and 11.1% in the two-dose OTA group (p<0.001), with no significant difference in transfusion rates between single- and two-dose OTA groups (p=0.357). Operating room time was reduced from 154 minutes in the no-OTA group to 144 minutes in the one-dose OTA group and 144 minutes in the two-dose OTA group (p<0.01). Additionally, maximum postoperative decline in hemoglobin was reduced from 4.3 g/dL in the no-OTA group to 3.5 g/dL in the single-dose OTA group (p<0.01) and 3.4 g/dL in the two-dose OTA group (p<0.01), without a significant difference between the single- and two-dose regimens (p=0.233). Conclusions. OTA reduces transfusions and operating room time, with the potential advantages of greater ease of administration and improved cost effectiveness relative to other routes of administration. Further study such as a randomized clinical trial is needed to verify the effectiveness of OTA and further optimize dosing regimens in the TKA setting. Level of Evidence. Therapeutic Level III

Aims

No predictive model has been published to forecast operating time for total knee arthroplasty (TKA). The aims of this study were to design and validate a predictive model to estimate operating time for robotic-assisted TKA based on demographic data, and evaluate the added predictive power of CT scan-based predictors and their impact on the accuracy of the predictive model.

Aims. Traditionally, acetabular component insertion during total hip arthroplasty (THA) is visually assisted in the posterior approach and fluoroscopically assisted in the anterior approach. The present study examined the accuracy of a new surgeon during anterior (NSA) and posterior (NSP) THA using robotic arm-assisted technology compared to two experienced surgeons using traditional methods. Methods. Prospectively collected data was reviewed for 120 patients at two institutions. Data were collected on the first 30 anterior approach and the first 30 posterior approach surgeries performed by a newly graduated arthroplasty surgeon (all using robotic arm-assisted technology) and was compared to standard THA by an experienced anterior (SSA) and posterior surgeon (SSP). Acetabular component inclination, version, and leg length were calculated postoperatively and differences calculated based on postoperative film measurement. Results. Demographic data were similar between groups with the exception of BMI being lower in the NSA group (27.98 vs 25.2; p = 0.005). Operating time and total time in operating room (TTOR) was lower in the SSA (p < 0.001) and TTOR was higher in the NSP group (p = 0.014). Planned versus postoperative leg length discrepancy were similar among both anterior and posterior surgeries (p > 0.104). Planned versus postoperative abduction and anteversion were similar among the NSA and SSA (p > 0.425), whereas planned versus postoperative abduction and anteversion were lower in the NSP (p < 0.001). Outliers > 10 mm from planned leg length were present in one case of the SSP and NSP, with none in the anterior groups. There were no outliers > 10° in anterior or posterior for abduction in all surgeons. The SSP had six outliers > 10° in anteversion while the NSP had none (p = 0.004); the SSA had no outliers for anteversion while the NSA had one (p = 0.500). Conclusion. Robotic arm-assisted technology allowed a newly trained surgeon to produce similarly accurate results and outcomes as experienced surgeons in anterior and posterior hip arthroplasty. Cite this article: Bone Jt Open 2021;2(6):365–370

INTRODUCTION. The efficacy and safety of the tourniquet are discussed, in particular with regard to the blood saving and tissue damage induced by ischemia. The quality of exsanguination and tissue necrosis in the compression zone are significant prognostic factors. The objective of this study was to evaluate the efficacy and safety of a new tourniquet system combining efficient and controlled exsanguination (figure 1) and ischemia maintained by pressure on a minimal surface (figure 2). The hypothesis tested was that the new system allowed tourniquet to reduce blood loss compared to conventional withers without increasing the risk of complications. MATERIAL. Two groups of 30 patients undergoing total knee arthroplasty (TKA) were compared. There were 39 women and 21 men with a mean age of 67 years and a mean BMI of 34. The study group was operated with the innovative tourniquet and followed prospectively. The control group was operated with the traditional tourniquet and analyzed retrospectively. METHODS. Operating time was measured between skin incision and dressing application. Blood loss was calculated with the Gross formula. Blood transfusion requirements were collected. Rehabilitation course was appreciated by the time to discharge. Complications, whether related or not to the tourniquet used, were recorded. Data were compared in both groups with the appropriate statistical tests at a 0.05 level of significance. The sample size was calculated to allow detecting a 300 ml decrease in mean blood loss with a power of 0.80. RESULTS. Both groups were comparable for all pre-operative data (age, gender, BMI, severity of the pre-operative deformation, pre-operative hematocrit level). Calculated blood loss was not significant different in the two groups (968 ml in the study group versus 1,022 ml in the control group, p<0.05). Operating time was not significantly decreased in the study group. Blood transfusion requirements were not significant different in the two groups (4 units versus 6 units). The complication rate was significantly decreased in the study group (no case versus 4 cases), especially for skin complications (3 cases of persistent bleeding or skin ischemia in the study group). The mean discharge time was significantly shorter in the study group (3rd post-operative day versus 5th post-operative day, p<0.05). DISCUSSION. The tested hypothesis was not confirmed. This preliminary study did not show any advantage of the new technology of tourniquet when analyzing blood loss. However, the decreased rate of local skin complications may be in relationship with a decreased intra-operative skin ischemia. This might lead to an earlier discharge. CONCLUSION. A prospective, randomized study is necessary to confirm these preliminary results

The common practice for insertion of distal locking screws of intramedullary (IM) nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure to patient and surgical personnel. A new technique is introduced which guides the surgeon by landmarks on the X-ray projection. 18 fresh frozen human below-knee specimens (incl. soft tissue) were used. Each specimen was instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland) and was mounted on an OR-table. Two distal interlocking techniques were performed in random order using a Siemens ARCADIS C-arm system (Siemens AG, Munich, Germany). The newly developed guided technique, guides the surgeon by visible landmarks projected onto the fluoroscopy image. A computer program plans the drilling trajectory by 2D-3D conversion and provides said guiding landmarks for drilling in real-time. No additional tracking or navigation equipment is needed. All four distal screws (2 mediolateral, 2 anteroposterior) were placed in each procedure. Operating time, number of taken X-rays and radiation time were recorded per procedure and for each single screw. 8 procedures were performed with the freehand technique and 10 with the guided technique. A 58% reduction in number of fluoroscopy shots per screw was found for the guided technique (7.4±3.4 vs. 17.6±10.3; p < 0.001). Total radiation time was 55% lower for the guided technique (17.1 ± 3.7s vs. 37.9 ± 9.1s) (p = 0.001). Operating time was shorter by 22% in the guided technique (3.2±1.2 min vs. 4.1±2.1 min p = 0.018). In an experimental setting, the newly developed guided freehand technique has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method enhances established clinical workflows and does not require cost intensive add-on devices or extensive training. A newly developed simple navigated technique has proven to markedly reduce radiation exposure and time for distal locking of intramedullary nails

Aims

In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component.

Aims

Robotic-assisted unicompartmental knee arthroplasty (R-UKA) has been proposed as an approach to improve the results of the conventional manual UKA (C-UKA). The aim of this meta-analysis was to analyze the studies comparing R-UKA and C-UKA in terms of clinical outcomes, radiological results, operating time, complications, and revisions.

Total knee arthroplasty (TKA) is a common procedure with good success rates. The literature shows resection accuracy plays a crucial role in device longevity. 1. Computer guidance is used by some surgeons to enhance accuracy. This study reports on a continuous series of Optetrak knee prostheses (Exactech Inc., FL, USA) implanted by three senior surgeons between October 2010 and December 2013. 324 TKA were implanted at the Joseph Ducuing Hospital, Toulouse, France (Site 1), the Cleveland Clinic, Cleveland, OH, USA (Site 2) and the Riverview Hospital, Noblesville, IN, USA (Site 3) using Exactech GPS (Blue-Ortho, Grenoble, FR), a new computer-assisted guidance system. Each centre in this study used different surgical profiles defined specifically for their surgeical preferences. Planned tibial and femoral cuts were compared to actual cuts digitised using GPS. Operating time was analyzed and post-operative leg alignment was compared to pre-operative. The mean error between planned and digitised proximal tibial cuts was 0.06°±0.89 of valgus and 0.53°±0.90 of anterior slope for Site 1, 0.18°±0.85 of varus and 0.25°±1.18 of posterior slope for Site 2, and 0.02°±0.51 of valgus and 0.60°±1.15 of anterior slope for Site 3. The mean error between planned and digitised femoral distal cuts was 0.14°±0.85 of valgus and 0.49°±0.93 of flexion for Site 1, 0.15°±0.96 of varus and 0.04°±1.54 of extension for Site 2, and 0.09°±0.54 of varus and 0.48°±1.21 of extension for Site 3. Average operating time was 29 minutes for Site 1, 39 minutes for Site 2, and 33 minutes for Site 3. Post-operative Hip-Knee-Ankle angle (HKA) varied between 172° and 184° with an average of 179° for Site 1, 177° to 183° with an average of 179° for Site 2, and 177° to 185° with an average of 180° for Site 3. Pre-operative HKA ranged from 162 to 189°. Site 1 was already reporting in the series presented at ISTA 2013. 2. Sites 2 and 3 were added later and could therefore benefit from the early feedback the analysis of site 1 cases provided. The use of the computer guidance at the new sites was associated with promising results and it did not take long to the surgeons to reach a reproducibility equivalent to the one of site 1. Average surgical time was similar in all three sites. GPS guidance added an average of 10 minutes to standard surgical times. All surgeons agreed the increased accuracy justified the additional time. Average post-operative HKA was 179°. HKA scores were within 3° of perfect alignment in 96% of the cases of Site 1, 99% of Site 2 and 97% of Site 3. According to the literature. 1. , HKA between 177° and 183° is linked with high implant survival. Participating surgeons still associated Exactech GPS with satisfactory immediate post-operative results

The Fixion expandable nailing system provides an intramedullary fracture fixation solution without the need for locking screws. Proponents of this system have demonstrated shorter surgery times with rapid fracture healing, but several centres have reported suboptimal results with loss of fixation. This is the largest comparative series to be reported to date. We compared outcomes between 50 consecutive diaphyseal tibial fractures treated with a Fixion device at our institution to an age, sex and fracture configuration matched series of 57 fractures at a neighbouring hospital treated with a conventional interlocked intramedullary nail. Minimum follow up time was 2 years. Operating time was significantly reduced in the Fixion group (mean 61 minutes, range 20–99) compared to the interlocked group (88 minutes, 52–93), p< 0.00001. The union rate was no different between the Fixion group (93.9%) and the interlocked group (96.5%), p=0.527. Time to clinical and radiological union was significantly faster in the Fixion group (median 85 days, range 42–243) compared to the interlocked group (119, 70–362), p< 0.0001. The overall reoperation rate was lower in the Fixion series (24.5% vs 38.6%, p=0.121), although the majority of reoperations in the interlocked group were more minor, for screw removal. 3 Fixion nails were revised for fixation failure and 2 manipulations were required for rotational deformities after falls; all of these patients were non-compliant with post-operative instructions. There were no fixation failures in the interlocked group. 3 fractures were noted to propagate during inflation of Fixion nails. The Fixion nail is faster to implant and allows more physiological loading of the fracture, with a faster union time. However, these advantages are offset by a reduction in construct stability. Our results have demonstrated a learning curve with a reduction in complications as our indications were narrowed, avoiding osteoporotic, multifragmentary, unstable fractures and non-compliant patients

We reported the first single surgeon series comparing outcome of microscopic and open primary single level unilateral lumbar decompression or discectomy. We aimed to determine any difference in outcomes between the two techniques. Forty-six decompressions were performed with use of an operating microscope (microscopic), and forty without (open) at two different hospitals. All procedures were performed by the senior author. Information was obtained by analysis of the patients' notes. The average age of the patients in both groups was comparable. Operating time was shorter in the microscopic group (68min, range 30-130) compared to the open group (83 mins, range 30-180). Dural tear rate was 4.3% with use of a microscope (0% symptomatic dural tear rate) and 7.5% without (2.5% symptomatic dural tear rate). Nerve damage incidence was 0% with use of a microscope and 5% (two patients) without. One of these was a neurapraxia and the patient made a full recovery. Wound infection rates, diagnosed on grounds of clinical suspicion, were 4.3% and 2.5% for microscopic and open respectively. There were no incidences of deep infection or post-operative discitis. Average inpatient stay was under 48 hours in both groups. Using the modified Macnab criteria, results using the microscope were 0% poor, 14% fair, 32% good, and 55% excellent. The results for the open group were 0% poor, 10% fair, 37% good and 53% excellent. Average follow-up was six months (1-19) for the microscope group, and seven months (2-16) for the open group. We conclude that primary single level unilateral lumbar decompressive surgery, performed without the use of a microscope, has a higher dural tear rate than the same surgery performed with the benefit of an operating microscope. Surgical time and incidence of nerve damage are also reduced by use of the microscope

The last decade has seen a rise in the use of the gamma nail for managing inter-trochanteric and subtrochanteric hip fractures. Patients with multiple co-morbidities are under high anaesthetic risk of mortality and are usually not suitable for general or regional anaesthesia. However, there can be a strong case for fixing these fractures despite these risks. Apart from aiming to return patients to their pre-morbid mobility, other advantages include pain relief and reducing the complications of being bed bound (e.g. pressure ulcers, psychosocial factors). While operative use of local anaesthesia and sedation has been documented for insertion of extra-medullary femoral implants such as the sliding hip screw, currently no literature is present for the insertion of the gamma nail. We studied intra-operative and post-operative outcomes of three patients aged between 64 and 83 with right inter-trochanteric hip fractures and American Society of Anesthesiologists (ASA) scores of 4 or more. Consent for each case was obtained after discussion with the patient and family, or conducted with the patient's best interests in mind. All patients received a short unlocked gamma nail, and were operated on within 24 hours of admission. Each patient underwent local injections of Bupivacaine or Lignocaine or both, with Epinephrine, and with one patient receiving nerve block of the fascia iliaca. Each patient received a combination of sedatives under the discretion of the anaesthetist including Midazolam, Ketamine, Propofol, Fentanyl, and/or Haloperidol. Operating time ranged from 30–90 minutes. Patients were managed post-operatively with analgesia based on the WHO pain ladder and physiotherapy. Our results showed no intra-operative complications in any of the cases. All patients noted improvement in their pain and comfort post-operatively without complications of the operation site. Two patients achieved their pre-morbid level of mobility after undergoing physiotherapy and were subsequently discharged from the orthopaedic team. One patient with ongoing pre-operative medical complications died 5 days after the operation. This study provides a glimpse into the use of local anaesthetic and sedation on high operative risk patients, and this may be a viable alternative to extra-medullary implants or non-operation. Further research is needed to quantify the risks and benefits of operating within this patient group

The primary objective of this study was to evaluate the performance of the Acrobot. ®. Sculptor system in achieving a surgical plan for implantation of unicompartmental knee prostheses, compared with conventional surgery. The Acrobot. ®. Sculptor is a novel hands-on medical device, consisting of a high speed cutter mounted on a robotic device which the surgeon holds and directs. A prospective, randomised, double-blind (patient and evaluator), controlled versus conventional surgery study was undertaken and has been fully reported in Journal of Bone and Joint Surgery (British), 88-B. All (13 out of 13) of the Acrobot. ®. cases were implanted with tibio-femoral alignment in the coronal plane within ±2° of the planned position, while only 40% (six out of 15) of the conventionally performed cases achieved this level of accuracy. There was also a significant enhancement in the extent of post-operative improvement, as measured by American Knee Society (AKS) Scores at six weeks, in the cases implanted with the Acrobot. ®. The difference between type of surgery is statistically significant (p=0.004, Mann-Whitney U test). Operating time (skin to skin) is higher in Acrobot treated subjects, but the difference between the two types of surgery fails to reach significance. The Acrobot. ®. System was found to significantly improve both accuracy and short term outcome in this investigation. By permitting the creation of bone surfaces that can be machined by means other than an oscillating saw, the Acrobot. ®. System paves the way for novel implant designs to be developed, facilitating bone conserving arthroplasty in the knee, hip and spine with a new generation of even less invasive but more reliable procedures

Background: Dysplasia of the hip is associated with hip pain and development of secondary osteoarthrosis. An early intervention by a PAO is both a pain relieving treatment and it prolongs or eliminates the development of osteoarthrosis. Different surgical approaches have been used to perform the PAO. We have compared a modified iliofemoral (MI) approach and the ilioinguinal (II) approach on acetabular reorientation, perioperative variables and clinical outcome. Patients and Method: We included 90 PAO’s performed on 75 patients with symptomatic hip dysplasia operated between February 2003 and July 2006 at Odense University Hospital. The variables in this study are center edge (CE) and acetabular roof angle (AA), Harris Hip score (HHS), WOMAC, pain (VAS), satisfaction with surgery, level of activity, quality of life (EQ5D), peri-operative blood loss, operating time and neurovascular complications. Results: The MI approach was used in 71 PAO’s and the II in 19 PAO’s. Overall, patients had a significantly better result after the PAO compared to before with regard to HHS, pain and WOMAC, EQ5D. Reorientation measured on pre- and post-operative CE- and AA-angles showed no significant difference between the two groups. Operating time proved the MI approach significantly faster then the II-approach (p< 0.05). The intraoperative blood loss and pre-operative Hb-conc. was equal in the two groups. However, there was a significant lower postoperative Hb-conc. using the II-approach. The II group had one case of arterial thrombosis and none in the MI group. In both groups, half the patients had dysaesthesia related to the lateral cutaneous femoral nerve. There were no significant differences between the two approaches with regard to pre- and post-operative HHS, WOMAC, patient satisfaction, level of activity and EQ5D. Conclusion: Although the II approach offers better access to the pubic bone, we did not find any difference in reorientation of the acetabular fragment. Both groups improved significantly in clinical outcome and quality of life. We find the MI approach safer than the II, as no arterial thrombosis was seen in that group

We report the result of 46 patients (30 female, 16 male) with periprosthetic femoral fractures who underwent insertion of the Kent Hip Prosthesis. Average age was 73 years (range 43–96years) and follow-up ranged from one to seven years (average, 4 years). The primary implants involved were as follows: Charnley (26), Austin Moore (6), Howse (5), Custom (4), Exeter (1), DHS (1), Thompson (1) and Richards (1). Average time to fracture from insertion of the primary implant ranged from 3 weeks to 20 years (average, 8 years). Forty cases were post-primary implant fractures (38 traumatic, 2 atraumatic) and 6 occurred intraoperatively. Using the Johanssen classification there were 12 type I, 30 type II and two type III fractures. Of the 46 cases, prior to fracture, 42 were living in their own home, 24 were mobile unaided and 20 had thigh and/or groin pain. Thirty-two had a loose stem and/or cup assessed at the time of surgery. Operating time was on average 143 mins (65–235mins). At latest follow-up, 43 were living in their own home, 5 were walking unaided and 10 had ongoing pain. In 34 cases complete union was achieved. There were no cases on non-union. Three patients required revision surgery for broken stems. Three patients sustained wound infections and there were six posterior dislocations. All of the complications were treated satisfactorily. We conclude that the Kent Hip Prosthesis is a useful option in the management of periprosthetic femoral fractures

Aims

The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours.

Arthrodesis of the ankle joint gives satisfactory short and medium-term results; however, in the longer term, it frequently leads to sub-talar and mid-tarsal osteoarthritis which is difficult to treat. Use of mobile bearings have significantly improved the results of ankle replacement. This a mid term follow up (1 to 5 years)of Buechel-Pappas ankle replacements performed by the senior author.34 total ankle replacements performed by one surgeon from October 1999 to May 2004 were reviewed retrospectively. Pre and post operative VAS scores, AOFAS scores were evaluated to find patient satisfaction and outcome. Tourniquet time as recorded in operation notes showed the learning curve for the procedure. Males : Females- 1:1.4. Mean age was 65 years (range : 33 to 83). Indication for surgery was primary osteoarthritis in 13, post traumatic arthritis in 14 and rheumatoid arthritis in 8. Average VAS score was 8.2 pre operative and improved to 2.0 at follow-up. AOFAS score improved from 39.1 to 72. Operating time averaged 113 minutes in 1999 and 85 in 2004. Significant complications were medial impingement (8) out of which 3 patients needed further surgery, intra-operative malleolar fractures (medial 4, lateral 1 and posterior 1, all healed successfully) and injury to cutaneous nerves (4) 3 patients had superficial infection which settled with antibiotics, but there were no cases of deep infection. 58 % were very happy, 32.5 % were happy, 9.5 % were not happy with the result. 2 patients had ankle fusion on the opposite side earlier, both were happier with the replaced side. Ankle replacements appear to offer a good alternative to fusion in selected patients. There is a significant risk of minor complications. Medial impingement may need further debridement at a later stage

Aims

Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre.

Aims

To identify variables independently associated with same-day discharge (SDD) of patients following revision total knee arthroplasty (rTKA) and to develop machine learning algorithms to predict suitable candidates for outpatient rTKA.

Introduction: Recently frameless stereotaxy has been introduced to assist with the spinal instrumentation. The mobility of individual vertebra however limits its accuracy and ease of use. The authors have developed a novel method of spinal stereotaxy using exact plastic copies of the spine manufactured using biomodelling technology. Methods: Fifteen patients with complex spinal disorders requiring instrumentation were recruited. A 3D CT scan of their spine was performed and the data were transferred via DICOM network to a computer workstation. ANATOMICS BIOBUILD software was used to generate the code required to manufacture exact acrylate biomodels of each spine using rapid prototyping. The biomodels were used to obtain informed consent from patients and simulate surgery. Simulation was performed using a standard power drill to place trajectory pins in the appropriate pedicles. Acrylate drill guides were manufactured using the biomodels as templates. The biomodels and templates were sterilised and used intra-operatively to assist with the placement of the instrumentation. Results: The biomodels were found to be highly accurate and of great assistance in the planning and execution of the surgery. The ability to drill optimum screw trajectories in the biomodel and then accurately replicate the trajectory was judged especially helpful. Accurate screw placement was confirmed with post-operative CT scanning. The design of the first two templates was suboptimal as the contact surface area was too great and complex. Approximately 20 minutes was spent pre-operatively preparing each biomodel and template. Operating time was reduced, as less reliance on intra-operative X-ray was necessary. Minimal invasive surgery was greatly facilitated in planning and execution. Patients stated that the biomodels improved informed consent. Conclusion: Biomodel spinal stereotaxy is a simple and accurate technique which may have advantages over frameless stereotaxy