Introduction and Aims: The authors present their results following treatment of 15 patients with
Failed total hip arthroplasty (THA) can require novel designs of revision implants that present unique risks as well as benefits. One of our patients endured a series of hip and knee revisions. In her twenties, she experienced a failed THA, became infected and all implants removed. In her early fifties (2008), she had a proximal femoral replacement incorporating a FreedomTM cup (Biomet, Warsaw, IN). She lacked hip musculature, was a dislocation risk, and cup constraint was necessary. Our choice of Freedom cup provided a 36mm head for enhanced stability and range-of-motion, plus the polyethylene liner was not as encompassing as other constrained designs, and the external clamping ring came pre-installed. This unique design allows for ease of head insertion during surgery. Our patient also had a CompressTM fixator combined knee-arthroplasty (Biomet). This knee fixation failed in 2013 and we installed a total femur combined hinge-knee arthroplasty. The Freedom cup was kept and post-op results were satisfactory. Follow-up appeared satisfactory in 2014. Some liner eccentricity was apparent but the patient had no complaints. Radiographs in February 2016 indicated cup's locking-mechanism was possibly failing but patient had no complaints. By December follow-up of 2016, the patient claimed she had 3 falls, and her x-rays indicated a displaced head and dislodged liner. At revision, the liner appeared well-seated inside the acetabular shell. However, about 50% of the polyethylene rim was missing and the large detached circumferential fragment represented the other 50%. A new Freedom liner was installed and her follow-up appears satisfactory to date. The fractured liner was sectioned through the thinnest wall (under detached rim fragment). The most critical design section was at site of the external locking ring, this wall thickness appearing < 3mm, whereas eccentric cup dome was 7.5–8mm thick. Under the detached rim fragment, wall thickness had been reduced (in vivo) to < 1mm. Given the robust rim profile, it seemed unlikely that the liner could have been spinning. The more likely scenario was that with repeated impingement, attempted subluxations by the femoral head stressed the contra- polyethylene rim, resulting in cold flow, thinning, and rim fragmentation. Two exemplar liners were compared, one similar to our patient's and one in a thicker design. Comparison of the sectioned retrieval to the new liners confirmed major loss of circumferential polyethylene. Our learning experience was threefold; (i) if we had been aware of the thin wall limitation, possibly we could have inserted the thicker liner (larger shell), (ii) we could have been more alert to the impending liner failure (x- ray imaging), and (iii) positioning the cup in a more horizontal orientation may have been an alternate solution, i.e. more coverage (but perhaps more impingement). Use of a 32mm head would have facilitated a thicker liner but this option was unavailable. In conclusion, it was notable that this constrained liner functioned very well for 7 years in our complex case and was easily revised at 8 years to another Freedom liner.
Introduction. Surgical simulation and ‘virtual’ surgical tools are becoming recognised as essential aids for speciality training in Trauma & Orthopaedics, as evidenced by the BOA T&O Simulation Curriculum 2013. 1,2. The current generation of hip arthroplasty simulators, including cadaveric workshops, offers the trainee limited exposure to reproducible real life bony pathology. We developed and implemented a novel training course using pathological dry bone models generated from real patient cases to support senior orthopaedic trainees and new consultants in developing knowledge and hands on skills in complex total hip arthroplasty. Patient/Materials & Methods. A two-day programme for 20 delegates was held at a specialist centre for hip arthroplasty. Three complex femoral and three complex acetabular cases were identified from patients seen at our centre. 3D models were printed from CT scans and dry bone models produced (using a mold-casting process), enabling each delegate to have a copy of each case at a cost of around £30 per case per delegate (Figure 1). The faculty was led by 4 senior Consultant revision hip surgeons. A computerised digitising arm was used to measure cup positioning and femoral stem version giving candidates immediate objective feedback (Figure 2). Candidate experience and satisfaction with the course and models was evaluated with a standardised post-course questionnaire. Results. 91% of respondents rated overall course satisfaction good or very good with 100% stating learning objectives were met or exceeded. 100% of delegates rated the bone model workshop cases as good or very good for the acetabular course, and 88% for the femoral course. Discussion. This course has been shown to enhance learning of surgical techniques and skills in
Restoring native hip biomechanics is crucial to the success of THA. This is reflected both in terms of complications after surgery such as instability, leg length inequality, pain and limp; and in terms of patient satisfaction. The challenge that remains is that of achieving optimal implant sizing and positioning so as to restore, as closely as possible, the native hip biomechanics specific to the hip joint being replaced. This would optimise function and reduce complications, particularly, instability. (Mirza et al., 2010). Ideally, this skill should also be reproducible irrespective of the surgeon's experience, volume of surgery and learning curve. The general consensus is that the most substantial limiting factor in a THA is the surgeon's performance and as a result, human errors and unintended complications are not completely avoidable (Tarwala and Dorr, 2011). The more challenging aspects include acetabular component version, sizing and femoral component sizing, offset and position in the femoral canal. This variability has led to interest in technologies for planning THA, and technologies that help in the execution of the procedure. Advances in surgical technology have led to the development of computer navigation and robotic systems, which assist in pre-operative planning and optimise intra-operative implant positioning. The evolution of surgical technology in lower limb arthroplasty has led to the development of computer navigation and robotics, which are designed to minimise human error and improve implant positioning compared to pre-operative templating using plain radiographs. It is now possible to use pre-operative computerised tomography (image-based navigation) and/or anatomical landmarks (non-imaged-based navigation) to create three-dimensional images of each patient's unique anatomy. These reconstructions are then used to guide bone resection, implant positioning and lower limb alignment. The second-generation RIO Robotic Arm Interactive Orthopaedic system (MAKO Surgical) uses pre-operative computerised tomography to build a computer-aided design (CAD) model of the patient's hip. The surgeon can then plan and execute optimal sizing and positioning of the prostheses to achieve the required bone coverage, minimise bone resection, restore joint anatomy and restore lower limb biomechanics. The MAKO robotic software processes this information to calculate the volume of bone requiring resection and creates a three-dimensional haptic window for the RIO-robotic arm to resect. The RIO-robotic arm has tactile and audio feedback to resect bone to a high degree of accuracy and preserve as much bone stock as possible. We have used this technology in the hip to accurately reproduce the anteversion, closure and center of rotation that was planned for each hip. Whilst the precise safe target varies from patient to patient, the ability to reproduce native biomechanics, to gain fixation as planned and to get almost perfect length and offset are a great advantage. Complications such as instability and leg length inequality are thus dramatically reduced.
Longevity of total hip arthroplasty (THA) is dependent upon avoiding both short- and long-term problems. One of the most common short-term / early complications of THA is instability while longer term issues of wear remain a concern. Both of these concerns appear to be related to implant position: either static or functional. While achieving “ideal” implant position in primary THA for osteoarthritis is only successful in 50% of cases (Callanan et al.), it is even more difficult in complex primary disorders such as dysplasia and post-traumatic arthritis. Many theories exist as to why implant position and short-term complications appear to be higher in this “complex primary” cohort but certainly the ability to achieve desired implant position appears to be more challenging. The loss of usual anatomic landmarks, the presence of soft tissue contractures, and the recognition of both pelvic and femoral deformities play a role. Enabling technologies have emerged to help in achieving improved implant position. These technologies include both navigation (both imageless and image guided) as well as the newly adopted technology of robotic assistance. Robot-assisted THA is based upon a CT scan protocol. Three-dimensional pre-operative planning on both the femoral and acetabular side can be performed. Precision guided bone preparation and exacting implant delivery is achievable using robotic technology. Examples of use of this technology in complex primary THA will be demonstrated including planning, preparation and implantation.
Background. Dynamic Hip Screw (DHS) is the most frequently used implant in management of intertrochanteric femoral fractures. There is a known statistical relationship between a tip-apex distance (TAD) >25mm and higher rate of implant failure. Our aim was to analyse all DHS procedures performed in our trust from seventeen months and compare their TAD values to the acceptable standard of ≤25mm. Methods. All patients undergoing DHS between April 2020-August 2021 were identified from our theatre system. Additionally, those presenting to hospital with implant failures were included. Patient demographics, date of surgery, fracture classification (AO) and date/mode of failure were recorded. Intraoperative fluoroscopy images were reviewed to calculate TAD, screw location and neck shaft angles by two independent observers. Results. 215 patients were identified, five of which were excluded due to inadequate fluoroscopy. Failure was seen in 3.3% of the cohort (n=7), of which 71.4% had an unacceptable TAD. In total, 21 patients (10%) had TAD >25mm, of whom 12 had superiorly and 15 had posteriorly placed screws. There were no failures in patients with a TAD of <20mm whereas a TAD >30mm had 50% failure rate. Conclusion. This audit reinforces the importance of aiming for a low TAD (preferably <20mm) intraoperatively. It is also desirable to avoid superiorly and significantly posteriorly placed screws. Implications.
Executing an extended retinacular flap containing the blood supply for the femoral head, reduction osteotomy (FHO) can be performed, increasing the potential of correction of
Among the advanced technology developed and tested for orthopaedic surgery, the Rizzoli (IOR) has a long experience on custom-made design and implant of devices for joint and bone replacements. This follows the recent advancements in additive manufacturing, which now allows to obtain products also in metal alloy by deposition of material layer-by-layer according to a digital model. The process starts from medical image, goes through anatomical modelling, prosthesis design, prototyping, and final production in 3D printers and in case post-production. These devices have demonstrated already to be accurate enough to address properly the specific needs and conditions of the patient and of his/her physician. These guarantee also minimum removal of the tissues, partial replacements, no size related issues, minimal invasiveness, limited instrumentation. The thorough preparation of the treatment results also in a considerable shortening of the surgical and of recovery time. The necessary additional efforts and costs of custom-made implants seem to be well balanced by these advantages and savings, which shall include the lower failures and revision surgery rates. This also allows thoughtful optimization of the component-to-bone interfaces, by advanced lattice structures, with topologies mimicking the trabecular bone, possibly to promote osteointegration and to prevent infection. IOR's experience comprises all sub-disciplines and anatomical areas, here mentioned in historical order. Originally, several systems of Patient-Specific instrumentation have been exploited in total knee and total ankle replacements. A few massive osteoarticular reconstructions in the shank and foot for severe bone fractures were performed, starting from mirroring the contralateral area. Something very similar was performed also for pelvic surgery in the Oncology department, where massive skeletal reconstructions for bone tumours are necessary. To this aim, in addition to the standard anatomical modelling, prosthesis design, technical/technological refinements, and manufacturing, surgical guides for the correct execution of the osteotomies are also designed and 3D printed. Another original experience is about en-block replacement of vertebral bodies for severe bone loss, in particular for tumours. In this project, technological and biological aspects have also been addressed, to enhance osteointegration and to diminish the risk of infection. In our series there is also a case of successful custom reconstruction of the anterior chest wall. Initial experiences are in progress also for shoulder and elbow surgery, in particular for pre-op planning and surgical guide design in complex re-alignment osteotomies for severe bone deformities. Also in complex flat-foot deformities, in preparation of surgical corrections, 3D digital reconstruction and 3D printing in cheap ABS filaments have been valuable, for indication, planning of surgery and patient communication; with special materials mimicking bone strength, these 3D physical models are precious also for training and preparation of the surgery. In Paediatric surgery severe multi planar & multifocal deformities in children are addressed with personalized pre-op planning and custom cutting-guides for the necessary osteotomies, most of which require custom allografts. A number of
The Revision Hip Complexity Classification (RHCC) was developed by modified Delphi system in 2022 to provide a comprehensive, reproducible framework for the multidisciplinary discussion of
Aims. Complex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips. Methods. In all, 27 THAs in 25 patients requiring THA with femoral shortening between 2012 and 2019 were assessed. Bilateral shortening was required in two patients. Subtrochanteric shortening was required in 14 out of 27 hips (51.9%) with aetiology other than DDH or septic arthritis. Vertical centre of rotation (VCOR), horizontal centre of rotation, offset, and functional outcome was calculated. The mean followup was 24.4 months (5 to 92 months). Results. The mean VCOR was 17.43 mm (9.5 to 27 mm) and horizontal centre of rotation (HCOR) was 24.79 mm (17.2 to 37.6 mm). Dislocation at three months following acetabulum reconstruction required femoral shortening for offset correction and hip centre restoration in one hip. Mean horizontal offset was 39.72 (32.7 to 48.2 mm) compared to 42.89 (26.7 to 50.6 mm) on the normal side. Mean Harris Hip Score (HHS) of 22.64 (14 to 35) improved to 79.43 (68 to 92). Mean pre-operative shortening was 3.95 cm (2 to 8 cm). Residual limb length discrepancy was 1.5 cm (0 to 2 cm). Sciatic neuropraxia in two patients recovered by six months, and femoral neuropraxia in one hip recovered by 12 months. Mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 13.92 (9 to 19). Mean 12-item short form survey (SF-12) physical scores of 50.6 and mental of 60.12 were obtained. Conclusion. THA with subtrochanteric shortening is valuable in
The burden of revision total hip arthroplasty (rTHA) continues to grow. The surgery is complex and associated with significant costs. Regional rTHA networks have been proposed to improve outcomes and to reduce re-revisions, and therefore costs. The aim of this study was to accurately quantify the cost and reimbursement for a rTHA service, and to assess the financial impact of case complexity at a tertiary referral centre within the NHS. A retrospective analysis of all revision hip procedures was performed at this centre over two consecutive financial years (2018 to 2020). Cases were classified according to the Revision Hip Complexity Classification (RHCC) and whether they were infected or non-infected. Patients with an American Society of Anesthesiologists (ASA) grade ≥ III or BMI ≥ 40 kg/m2 are considered “high risk” by the RHCC. Costs were calculated using the Patient Level Information and Costing System (PLICS), and remuneration based on Healthcare Resource Groups (HRG) data. The primary outcome was the financial difference between tariff and cost per patient episode.Aims
Methods
Although the introduction of ultraporous metals in the forms of acetabular components and augments has substantially improved the orthopaedic surgeon's ability to reconstruct severely compromised acetabuli, there remain some revision THAs that are beyond the scope of cups, augments, and cages. In situations involving catastrophic bone loss, allograft-prosthetic composites or custom acetabular components may be considered. Custom components offer the potential advantages of immediate, rigid fixation with a superior fit individualised to each patient. These custom triflange components require a preoperative CT scan with three-dimensional (3-D) reconstruction using rapid prototyping technology, which has evolved substantially during the past decade. The surgeon can fine-tune exact component positioning, determine location and length of screws, modify the fixation surface with, for example, the addition of hydroxyapatite, and dictate which screws will be locked to enhance fixation. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. We previously reported on our center's experience with 23 patients (24 hips) treated with custom triflange components with minimum 2-year follow-up. This method of reconstruction was used in a cohort of patients with Paprosky Type 3B acetabular defects, which represented 3% (30 of 955) of the acetabular revisions we performed during the study period of 2003 to 2012. At a mean follow-up of 4.8 years (range, 2.3 – 9 years) there were four subsequent surgical interventions: two failures secondary to sepsis, and one stem revision and one open reduction internal fixation for periprosthetic femoral fracture. There were two minor complications managed nonoperatively, but all of the components were noted to be well-fixed with no obvious migration or loosening observed on the most recent radiographs. Harris hip scores improved from a mean of 42 (SD ±16) before surgery to 65 (SD ±18) at latest follow-up (p < 0.001). More recently, we participated in a multi-center study of 95 patients treated with reconstruction using custom triflange components who had a mean follow-up of 3.5 years. Pelvic defects included Paprosky Type 2C, 3A, 3B and pelvic discontinuity. Concomitant femoral revision was performed in 21 hips. Implants used a mean of 12 screws with 3 locking screws. Twenty of 95 patients (21%) experienced at least one complication, including 6% dislocation, 6% infection, and 2% femoral-related issues. Implants were ultimately removed in 11% of hips. One hip was revised for possible component loosening. Survivorship with aseptic loosening as the endpoint was 99%. Custom acetabular triflange components represent yet another tool in the reconstructive surgeon's armamentarium. These devices can be helpful in situations of catastrophic bone loss, achieving reliable fixation. Clinical results are inferior to both primary THA and more routine revision THA. Patients and surgeons should be aware of the increased complications associated with these
Aim: To report our experience and early results with the Ilizarov pelvic support realignment lengthening osteotomy for
With increasing burden of revision hip arthroplasty, one of the major challenge is the management of bone loss associated with previous multiple surgeries. Proximal femoral replacement (PFR) has already been popularised for tumour surgeries. The inherent advantages of PFR over allograft –prosthesis system, which is the other option for addressing severe bone loss include, early weight bearing and avoidance of non-union and disease transmission. Our study explores PFR as a possible solution for the management of
Although the introduction of ultraporous metals in the forms of acetabular components and augments has substantially improved the orthopaedic surgeon's ability to reconstruct severely compromised acetabuli, there remain some revision THAs that are beyond the scope of cups, augments, and cages. In situations involving catastrophic bone loss, allograft-prosthetic composites or custom acetabular components may be considered. Custom components offer the potential advantages of immediate, rigid fixation with a superior fit individualised to each patient. These custom triflange components require a pre-operative CT scan with 3-D reconstruction using rapid prototyping technology. The surgeon can fine-tune exact component positioning, determine location and length of screws, modify the fixation surface with, for example, the addition of hydroxyapatite, and dictate which screws will be locked to enhance fixation. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. We previously reported on our center's experience with 23 patients (24 hips) treated with custom triflange components with minimum 2-year follow-up. This method of reconstruction was used in a cohort of patients with Paprosky Type 3B acetabular defects, which represented 3% (30 of 955) of the acetabular revisions we performed during the study period of 2003 to 2012. At a mean follow-up of 4.8 years (range, 2.3–9 years) there were 4 subsequent surgical interventions: 2 failures secondary to sepsis, and 1 stem revision and 1 open reduction internal fixation for periprosthetic femoral fracture. There were two minor complications managed non-operatively, but all of the components were noted to be well-fixed with no obvious migration or loosening observed on the most recent radiographs. Harris Hip Scores improved from a mean of 42 (SD ±16) before surgery to 65 (SD ±18) at latest follow-up (p<0.001). More recently, we participated in a multi-center study of 95 patients treated with reconstruction using custom triflange components w a mean follow-up of 3.5 years. Pelvic defects included Paprosky Type 2C, 3A, 3B and pelvic discontinuity. Concomitant femoral revision was performed in 21 hips. Implants used a mean of 12 screws with 3 locking screws. Twenty of 95 patients (21%) experienced at least one complication, including 6% dislocation, 6% infection, and 2% femoral-related issues. Implants were ultimately removed in 11% of hips. One hip was revised for possible component loosening. Survivorship with aseptic loosening as the endpoint was 99%. Custom acetabular triflange components represent yet another tool in the reconstructive surgeon's armamentarium. These devices can be helpful in situations of catastrophic bone loss, achieving reliable fixation. Clinical results are inferior to both primary THA and more routine revision THA. Patients and surgeons should be aware of the increased complications associated with these
Background: The implications of clinical governance, changing epidemiology, financial restraints alongside the increasing demands of the informed consumer-patient mean we must continually adapt our practice to efficiently meet expectations. As a busy regional Trauma and Orthopaedics Unit of a District General Hospital we are increasingly affected by economic agendas and have noted an increase in the presenting frailty of our fracture hip patients. Our practice has already changed by the use of an Orthogeriatrics Team (OGT): optimising patient status pre-operatively and ensuring maximum post-operatively continuity. The OGT has significantly reduced time to theatre. With appropriate investigation and lower complication rates it will offset the cost of the team. We wanted to see if the care of fractured hip patients could be further focused. On this basis, a four-part clinical stratification system was devised for patients undergoing fractured
With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS).Aims
Methods
In patients with developmental dysplasia of the hip (DDH) chronic joint dislocation induces remodeling of the soft tissue with contractures, muscle atrophy, especially of the hip abductors muscles, leading to severe motor dysfunction, pain and disability (1). The aim pf the present work is to explore if a correct positioning of the prosthetic implants through 3D skeletal modeling surgical planning technologies and an adequate customized rehabilitation can be beneficial for patients with DDH in improving functional performance. The project included two branches: a methodology branch of software development for the muscular efficiency calculation, which was inserted in the Hip-Op surgical planning system (2), developed at IOR to allow surgical planning for patients with
Introduction. Range of motion (ROM) simulation of the hip is useful to understand the maximum impingement free ROM in total hip arthroplasty (THA). In spite of a complex multi-directional movement of the hip in daily life, most of the previous reports have evaluated the ROM only in specific directions such as flexion-extension, abduction-adduction, and internal - external rotation at 0° or 90° of hip flexion. Therefore, we developed ROM simulation software (THA analyzer) to measure impingement free ROM in any positions of the hip. Recent designs of the hip implants give a wider ROM by increasing the head diameter and then, bone to bone impingement can be a ROM limit factor particularly in a combination of deep flexion, adduction and internal rotation of the hip. Therefore, the purpose of this study were to observe an individual variation in the pattern of the bone impingement ROM in normal hip bone models using this software, to classify the bone impingement ROM mapping types and to clarify the factors affecting the bone impingement type. Methods. The subjects were 15 normal hips of 15 patients. Three dimensional surface models of the pelvis and femur were reconstructed from Computer tomography (CT) images. We performed virtual hip implantation with the same center of rotation, femoral offset, and leg length as the original hips. Subsequently, we created the ROM mapping until bone impingement using THA analyzer. We measured the following factors influenced on the bone impingement map patterns; the neck shaft angle, the femoral offset, femoral anteversion, pelvic tilt, acetabular anteversion, sharp angle, and CE angle. These factors were compared between the two groups. Statistical analysis was performed with Mann-Whitney U test, and statistical significance was set at P<0.05. Results. According to the borderline of ROM at the flexion-internal rotation corner on the bone impingement map, the hips were classified into two groups; group-A showed more than 45° of the borderline slope at the flexion-internal rotation corner and the remaining hips were group-B. (Fig.1). There were 7 hips in group-A and 8 hips in group-B. Femoral offset was 36.8±2.2 mm in group-A and 30±2.7 mm in group-B. Femoral anteversion was 32±6.4° in-group A and 43 ±4.8° in group-B. There were statistically significant differences in the femoral offset and femoral anteversion between the groups. There were no significant differences in the other factors. Discussion. The results of this study showed various ROM map patterns even in normal hips and we classified them into two groups. An increased femoral offset or a decreased femoral anteversion revealed an early impinge in internal rotation. ROM until bone impingement is affected by the individual bone morphology. However, it is not easy to evaluate bony ROM in