Preoperative Templating Research Articles

Clinical characteristics and risk factors of periprosthetic femoral fractures associated with hip arthroplasty

Periprosthetic femoral fracture (PFF) is a complicated complication of both primary and revision hip arthroplasty with an increasing incidence. The present study aimed to summarize the clinical characteristics and identify the risk factors for PFF which would be potentially helpful in the prevention and treatment of PFF.We retrospectively analyzed the clinical data of 89 cases of PFF, and a case–control study was designed to identify the potential risk for intraoperative and postoperative PFF in both primary and revision hip arthroplasty.The overall incidence of PFF was 2.08% (intraoperative: 1.77%, postoperative: 0.30%, revision: 13.60%, and primary: 0.97%). The most commonly used treatment strategy was fixation with cerclage wire or band for intraoperative PFF, whereas long stem revision with plate or cortical allograft strut fixation was the main treatment strategy for postoperative PFF. The risk factors for intraoperative PFF in primary total hip arthroplasty (THA) included the diagnosis of development dysplasia of the hip (DDH) (odds ratio [OR] = 5.01, 95%CI, 1.218–20.563, P=0.03) and CBR ≥ 0.49 (OR = 3.34, 95%CI, 1.138–9.784, P = 0.03). The increased age was associated with increased incidence of postoperative PFF in primary THA (OR = 1.09, 95%CI, 1.001–1.194, P = 0.04). As for the intraoperative PFF in revision THA, we found that receiving multiple operations before revision (OR = 2.45, 95%CI, 1.06–5.66, P = 0.04), revisions due to prosthetic joint infection (OR = 6.72, 95%CI, 1.007–44.832, P = 0.04), the presence of cementless implant before revision (OR = 13.54, 95%CI, 3.103–59.08, P = 0.001), and femoral deformity (OR = 8.03, 95%CI, 1.656–38.966, P = 0.01) were all risk factors.Screening for high-risk patients, preoperative templating, and detailed discharge instructions may be the potential strategies to reduce the incidence of PFF. The treatment of PFFs should take into account Vancouver classification system, patient's characteristics as well as the experience of the operating surgeon.

Radiographic templating of total hip arthroplasty for femoral neck fractures.

The purpose of this study was to evaluate the use of pre-operative digital templating to minimize complications including limb length discrepancy (LLD), intraoperative fractures and early dislocations in patients with intracapsular femoral neck fractures. We retrospectively compared 23 patients undergoing total hip arthroplasty (THA) for intracapsular femoral fractures with pre-operative digital templating and 48 patients without templating. The mean post-operative LLD was significantly lower in patients who had pre-operative templating than in the control group (6.7 vs. 11.5mm, p = 0.023). Only three patients (13%) with templating had LLD greater than 1.5cm, compared to the 15 patients (31%) without templating (p = 0.17). In eight cases the final femoral stem size matched the templated size, while 19 patients were within two size increments. Complications included one dislocation and one intra-operative fracture in the control group. The present study demonstrated that careful pre-operative planning may reduce LLD in patients undergoing THA due to intracapsular hip fractures.

Trabecular TitaniumTM cups and augments in revision total hip arthroplasty: clinical results, radiology and survival outcomes.

Large acetabular defects remain a challenge in hip revision arthroplasty. Experience with Trabecular Titanium™ (TT) cups (Limacorporate S.p.a.) has not been widely reported. Therefore, we assessed the survivorship and clinical and radiological outcomes of patients receiving TT cups, with or without supplementary trabecular titanium hemispherical modules for acetabular reconstruction, in primary and revision total hip arthroplasty (THA). Between January 2009 and July 2014, we performed 67 revisions and 5 primary THAs using TT cups in 69 patients. To achieve stability and/or restore the hip's centre of rotation, hemispherical modules were used in 17 cases based on preoperative templating and/or intraoperative findings. Mean follow-up was 30.5 months. Acetabular bone defects were classified according to the Paprosky classification. Survivorship, functional outcomes (Merle d'Aubigné) and radiological outcomes were analysed. 8 patients underwent cup revision: 2 for loosening, 3 for infection, and 3 for hip dislocation. The remaining cases did not present radiological signs of loosening. None of the cases with Paprosky type I classifications needed revision, while 4 with type II and 4 with type III needed revision (p = 0.028). The respective mean values for pain, walking, and range of motion (Merle d'Aubigné scores ± standard deviation) were 3.6 ± 1.4, 3.7 ± 0.7, and 3.8 ± 0.6 preoperatively, and 5.7 ± 0.7, 5.3 ± 0.7, and 5.6 ± 0.7 at the latest follow-up (p<0.001). In the short term, results with TT cups appear to be encouraging, with satisfactory survival rates for both simple and complex cases.

Quality Improvement

Quality Improvement

Pre-operative templating in total elbow arthroplasty: not useful.

Total elbow arthroplasty (TEA) is a definitive surgical procedure for treating rheumatoid arthritis and (posttraumatic) osteoarthritis of the elbow and is also useful in comminuted elbow fractures. Pre-operative digital templating may theoretically improve the surgical implantation of TEA, but reliability and predictive values of templating are unknown. The aim of this study was to determine the intra- and inter-observer reliability and the validity of pre-operative digital templating for TEA. All pre-operative plain anterior-posterior and lateral calibrated elbow radiographs from patients who underwent TEA in our center from 2008 to June 2014 were reviewed. Two independent assessors templated implant sizes using digital overlays twice. Intra- and inter-observer reliability were evaluated with Cohen's kappa. Two experienced elbow surgeons reviewed post-operative radiographs for evaluation. The predictive value of templating was the percentage of the correctly templated sizes, with the optimal implant size as the reference standard. Twenty-one cases were included. Intra-observer reliability was substantial to almost perfect (κ=0.61 and κ=0.90) for humeral implants, moderate to substantial (κ=0.54 and κ=0.73) for ulnar implants. Inter-observer reliability was substantial (κ=0.67) for humeral implants and moderate (κ=0.60) for ulnar implants. The predictive value was 53% for both implants. Pre-operative digital templating for TEA is a reliable method to plan implant sizes. However, the predictive value is low.

Surgical tips of intramedullary nailing in severely bowed femurs in atypical femur fractures: Simulation with 3D printed model

IntroductionThe surgical management of atypical femoral fractures (AFFs) is complex in cases with severe bowing of the femur, being associated with a high rate of failure. Our first aim was to use preoperative templating and 3D printed model characterise the technical difficulties associated with use of current commercially available intramedullary nail (IMN) systems for the management of AFFs with severe bowing. Our second aim was to use outcomes of our 3D printing analysis to define technical criteria to overcome these problems. Material and MethodsThe modelled femur with 3D printing had an anterior bowing curvature radius of 772mm and an angle of lateral bowing of 15.4°. Nine commercially available IMN systems were evaluated in terms of position of the nail within the medullary canal, occurrence of perforation of femoral cortex by the distal tip of the nail, and location of the site of perforation relative to the knee joint. The following IMN systems were evaluated: unreamed femoral nail (UFN), cannulated femoral nail (CFN), Sirus nail, right and left expert Asian femoral nail (A2FN), right and left Zimmer Natural Nail (ZNN), proximal femoral nail anti-rotation (PFNA), and Zimmer Cephalomedullary Nail (CMN). ResultsAlong the sagittal plane, the UFN, CFN and Sirus systems were acceptably contained within the medullary canal, as well as the “opposite side” A2FN and ZNN. Only the Sirus IMN system was contained along the coronal plane. The distal part of the all other IMN systems perforated the anterior cortex of the femur, at distances ranging between 2.8 and 11.7cm above the distal end of the femoral condyles. Using simulated fracture reduction in the 3D printed model, none of the 9 IMN systems provided acceptable anatomical reduction of the fracture. A residual gap in fragment position and translation was provided by the “opposite side” ZNN, followed by the UFN and Sirus systems. ConclusionCommercially available IMN systems showed mismatch with severely bowed femurs. Our simulation supports that fit of these systems can be improved using an IMN system with a small radius of curvature and diameter, and by applying specific operative procedures.

2D versus 3D templating in total knee arthroplasty

BackgroundPreoperative digital templating in total knee arthroplasty (TKA) helps to determine the need of non-standard implants, prophesies the bony resections and helps to anticipate the intraoperative plan. Templating within the process of patient specific instrumentation (PSI) is fairly new and 2D planning has not been compared to PSI templating. Methods94 patients underwent unilateral primary TKA with magnetic resonance imaging (MRI) based preoperative templating and PSI cutting blocks. Parallel to this, three observers templated all cases using digital planning on standard preoperative x-rays. The examiners templated all cases independently and were blinded to the component sizes used intraoperatively. ResultsThree-dimensional (3D) templating was accurate in predicting the correct implant size in 100% of the cases. The femoral and tibial two-dimensional (2D) digital templating varied from 43.6% to 59.5% and 52.1% to 68% of the cases. When allowing ±1 difference, femoral 2D digital templating varied from 93.6% to 97.8% of the cases and ranged from 94.6% to 98.9% on the tibial side. All observers show “very good” correlation. The coefficient indicates a very good agreement in between the three observers. Conclusion3D templating has very high accuracy for the actual implant size prediction. Compared to this, 2D digital templating is an accurate method to approximately (±1 size) determine the size of TKA components. However, we judge this technique accurate enough, that 2D templating allows launching Template-directed instrumentation (TDI), while the examiner does not need a high level of clinical experience. Clinical relevanceWithin the process of digital planning, the surgeonmight focus evenmore on the upcoming operation.

Accuracy of a Simple Digital Templating in Primary Uncemented Total Hip Arthroplasty.

To introduce a simple preoperative digital templating in uncemented total hip arthroplasty (THA) and to determine its accuracy for preoperative size selection of the prostheses. A prospective study of digital planned THAs was performed on 90 hips with different types of prostheses from August 2013 to Angust 2014. The plastic templates of different types of prostheses were scanned for desired digital templating and the scanned images were then processed to the transparent, digital templates using Photoshop software. We calibrated the scales of the digital templates with the preoperative radiographs, and then selected the right size of the component. The preoperatively digital planned component sizes were compared to the actual sizes used in the operation, as well as the preoperatively traditional planned sizes. In either cup or stem templating, no difference was found among the groups with different types of prostheses, and the accuracy of digital templating was statistically higher than traditional templating. In cup templating, digital planned and implanted cup sizes were identical in 43.33% of the cases, 78.89% of the cup sizes were predicted within 1 size (± 2mm) and 95.56% were predicted within 2 sizes (± 4 mm), all significantly higher than the results of traditional planned sizes (30.00%, P=0.044; 61.11%, P=0.007; 82.22%, P=0.004). The exact femoral stem size was predicted in 40.00% of cases using the digital templating, 84.44% of stem sizes were predicted within 1 size, and 93.33% within 2 sizes, better than using traditional templating (25.56%, P=0.028; 53.33%, P<0.001; 77.77%, P=0.003). This simple digital preoperative templating is an accurate and reproducible process to preoperatively predict the implant size of uncemented THA.

Modular tapered fluted stems: An accommodating option in the setting of femoral bone deficiency

Tapered, fluted, modular, titanium stems are being used more frequently for revision total hip arthroplasty to address femoral bone deficiencies. Mid- and long-term survivorship studies demonstrate that these stems are a durable implant design, while outcome studies show that they provide favorable patient satisfaction and function. Subsidence, implant fracture, and stress shielding are frequently encountered complications, which can be minimized through the use of meticulous preoperative templating, direct visualization of the femoral stem using mini C-arm fluoroscopy, and through the use of a kinked femoral implant. By using these techniques, a canal-filling implantation technique can be achieved.

Short-Stem Hip Arthroplasty as a Solution for limited Proximal Femoral Bone Stock

We describe an uncommon scenario where the femoral diaphysis was subjugated by previous long stemmed revision knee replacements limiting options for primary hip arthroplasty. A short stemmed pressfit femoral componet was implanted bilaterally. At 11 years the implants remain stable with improved clinical function. This case emphasizes the importance of preoperative templating and the utility of considering the use of unconventional stems in the management of unusual situations.

Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup.

Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant. We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions. Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence. The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed. The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients. Level IV, therapeutic study.

Outcomes of reverse shoulder arthroplasty using a mini 25-mm glenoid baseplate.

As worldwide use of reverse shoulder arthroplasty (RSA) increases, a range of implant sizes may be required to match regional and ethnic variation in patients' height and bone size. The purpose of this study was to report the outcomes of RSA using a mini 25-mm-diameter glenoid baseplate in smaller patients with rotator cuff arthropathy. Between 2009 and 2012, 28 patients underwent RSA for cuff-tear arthropathy using a 25-mm circular glenoid baseplate (Aequlais Reversed, Tornier, Bloomington, MN, USA). Twenty-four patients were able to return for comprehensive follow-up. The mean height of the entire cohort was 158 ± 10 cm (5 ft. 2 in.). The indication to use a smaller baseplate was a combination of preoperative templating using computed tomography (CT) and intraoperative measurements of glenoid width. At a mean of 36 ± 8 months' follow-up, there were no revisions or glenoid-sided failures. The mean American Shoulder and Elbow Surgeons (ASES) score was 70 ± 10, the Simple Shoulder Test (SST) was 10 ± 2, the Constant was 60 ± 10 and the Disabilities of the Arm, Shoulder and Hand (DASH) was 18 ± 15. Mean active forward elevation was 140 ± 15°, active external rotation was 21 ± 15° and active internal rotation was to the sacroiliac joint. Mean shoulder strength in flexion was 5.2 ± 1.7 kg, in external rotation was 2.9 ± 1.4 kg and in internal rotation was 4.3 ± 1.2 kg. Radiographs demonstrated no evidence of glenoid loosening. There was, however, a 62 % rate of scapular notching. Short-term outcomes of mini 25-mm baseplate RSA in proportionally smaller patients are good and demonstrate implant safety and effectiveness. Scapular notching rates are worrisome, and additional follow-up is necessary to determine if notching is progressive and becomes symptomatic.

Pre-operative templating for trauma hemiarthroplasty (Thompson's)

IntroductionSurgical complications may be avoided by preoperative templating in trauma hemiarthroplasty. Materials and methodsDigital templates for the Stryker™ range of Thompson's prostheses were created and fifty trauma patients that had undergone cemented hemiarthroplasty were retrospectively templated by 2 blinded surgeons. ResultsTemplating for prosthesis size was highly accurate with excellent Inter and intra-observer reproducibility. Sensitivity for identifying femoral canals too narrow for a Thompsons was 100%. ConclusionsTemplating is a valuable tool and should be standard practice in trauma. We have demonstrated that it is possible to generate custom templates to allow accurate templating.

Template-Directed Instrumentation Reduces Cost and Improves Efficiency for Total Knee Arthroplasty: An Economic Decision Analysis and Pilot Study

Template-directed instrumentation (TDI) for total knee arthroplasty (TKA) may streamline operating room (OR) workflow and reduce costs by preselecting implants and minimizing instrument tray burden. A decision model simulated the economics of TDI. Sensitivity analyses determined thresholds for model variables to ensure TDI success. A clinical pilot was reviewed. The accuracy of preoperative templates was validated, and 20 consecutive primary TKAs were performed using TDI. The model determined that preoperative component size estimation should be accurate to ±1 implant size for 50% of TKAs to implement TDI. The pilot showed that preoperative template accuracy exceeded 97%. There were statistically significant improvements in OR turnover time and in-room time for TDI compared to an historical cohort of TKAs. TDI reduces costs and improves OR efficiency.

Arthroplasty in patients with extensive femoral head avascular necrosis: Cementless arthroplasty in extensive femoral head necrosis.

The purpose of this study was to investigate the outcomes of using cementless femoral stem for extensive osteonecrosis of the femoral head involving the proximal femur. A total of 21 patients (27 hips) in the study group defined as extensive ONFH involving proximal femur and 42 patients (52 hips) with the diagnosis of regular osteonecrosis of the femoral head in the control group were enrolled in the study. Clinical and radiographic follow-ups were documented at three, six, 12 and 24 months postoperatively. Results improved for Harris hip score in both groups. In the study group undersized stem implantation and lateralized mal-position were identified. Subsequent subsidence was also found. Pre-operative templating and intra-operative X-ray confirmation are necessary to avoid complications.

下顎骨再建術における術前プレートの屈曲・テンプレート作成による手術効率化への工夫

下顎骨再建術における術前プレートの屈曲・テンプレート作成による手術効率化への工夫

Lateral Opening-wedge Distal Femoral Osteotomy: Pain Relief, Functional Improvement, and Survivorship at 5Years.

Distal femoral varus osteotomy may be used to treat valgus knee malalignment or to protect a knee compartment in which cartilage restoration surgery (such as osteochondral or meniscus allografting) has been performed. Medial closing-wedge osteotomy has demonstrated good success in treatment of osteoarthritis in published series, but few studies have evaluated distal femoral lateral opening-wedge osteotomy in terms of correction of deformity, pain and function, and survivorship. (1) Does lateral opening-wedge osteotomy lead to accurate correction? (2) What pain and function levels do patients experience after lateral opening-wedge osteotomy? (3) What are the nonunion, complication, and reoperation rates after lateral opening-wedge osteotomy? Between 2000 and 2010, we performed 40 distal femoral osteotomies. Two knees (two patients) underwent a medial closing-wedge osteotomy and were excluded from the present study. Thirty-eight knees (97%) in 36 patients were lateral opening-wedge varus-producing osteotomies; of those, 31 knees (82%) in 30 patients had followup at a minimum of 2years (mean, 5years; SD, 2; range, 2-12years) and comprised the study population. The indications for osteotomy included symptomatic lateral compartment arthritis with clinical valgus deformity or a cartilage or meniscal defect in the lateral compartment with clinical valgus alignment. The study population was stratified into two groups based on reason for osteotomy: patients with isolated symptomatic lateral compartment arthritis (arthritis group; 19 knees [61%]) and patients who underwent joint preservation procedures including osteochondral allograft transplantation or meniscal allograft transplantation (joint preservation group; 12 knees [39%]). Data collection from our institution's osteotomy database included patient demographics, lower extremity coronal alignment, and operative details. Pain and function were measured preoperatively and postoperatively using the International Knee Documentation Committee (IKDC) score. Time to radiographic union, complications, and reoperations were recorded. Twenty-one of 31 knees had postoperative radiographic data available for review. Of these, seven of 15 knees in the arthritis group and three of six knees in the joint preservation group were within the correction goal of±3° from neutral mechanical alignment. In the arthritis group, the mean IKDC total score improved from 47 (SD, 15) preoperatively to 67 (SD, 10) postoperatively. In the joint preservation group, the mean IKDC total score improved from 36 (SD, 12) preoperatively to 62 (SD, 18) postoperatively. One nonunion occurred in the arthritis group. No postoperative complications were experienced. Ten knees in the arthritis group and six knees in the joint preservation group had additional surgery after the osteotomy, consisting primarily of hardware removal, arthroscopy for cartilage-related conditions, or conversion to arthroplasty. Survivorship at 5years, with conversion to arthroplasty as the endpoint, was 74% in the arthritis group and 92% in the joint preservation group. Lateral opening-wedge distal femoral osteotomy was less accurate in correction of valgus deformity than expected, but the procedure was associated with improved knee pain and function scores. Our clinical and radiographic results are comparable to published series evaluating medial closing-wedge distal femoral osteotomy. Achieving our desired correction of±3° from neutral alignment was clinically difficult. An improved method of preoperative templating and refinement of the intraoperative technique may improve this. Future studies with more patients and longer followup will provide clarity on this topic. Level IV, therapeutic study.

A Patient-Specific Predictive Model Increases Preoperative Templating Accuracy in Hip Arthroplasty

Application of digital radiography during preoperative templating has shown potential to reduce complications in total hip arthroplasty. In this study, we aimed to further improve digital templating by using a predictive model built on patients' specific data. The model was significant in improving the accuracy of templating within ±1 size of acetabular component (χ2(1, N=468)=19.314, P<0.0001, Φ=0.604, and odds-ratio: 7.750 (95% CI 2.740–30.220)). We successfully achieved a 99% accuracy within ±2 of templated size. Additionally, patient demographics, such as height and weight, have shown significant effects on the predictive model. The outcome of this study may help reducing the costs of health care in the long term by minimizing implant inventory costs.

Influence of contralateral radiographs on accuracy of anatomic reduction in surgically treated calcaneus fractures.

The purpose of this study was to determine whether obtaining a radiograph of the uninjured contralateral calcaneus (template) before surgery allowed for more precise restoration of Bohler's angle and calcaneal length when performing open reduction internal fixation (ORIF) of intra-articular calcaneus fractures. Patients who sustained an intra-articular calcaneus fracture requiring surgery who met inclusion criteria were prospectively randomized into those who had a preoperative template obtained for review at the time of ORIF (group 1) versus those who had the contralateral radiograph obtained after surgery (group 2). There was no benefit of the preoperative template in allowing for more anatomic restoration of Bohler's angle or calcaneal length. Operative time was decreased with the use of a preoperative template when using the extensile lateral or percutaneous approaches. Preoperative templating of the uninjured contralateral calcaneus did not allow for more anatomic reduction or restoration of pre-injury morphology of the calcaneus undergoing operative fixation as based on Bohler's angle and calcaneal length. Templating may be of benefit by reducing operative time. Level II, prospective comparative series.

No Rationale for Gender Specific Femoral Stems for Total Hip Arthroplasty

The purpose of this study was to compare the applicability of two femoral stem systems in male and female populations via preoperative templating. The radiographs of 47 consecutive patients (94 hips) were templated using one of two stem systems by first fixing the acetabular center of rotation. Based upon templating, the result categories were: no obvious advantage of either system, System 1 preferred, System 2 preferred, neither system adequate. Preference was determined based upon having a best-fit stem choice and at least one additional length or offset option, and avoiding the extremes of the system as the best-fit choice. Significantly, there were gender differences in applicability of femoral stems. Specifically, more neck length and offset options seem to be required for females. The potential limitations of the implant systems in applicability could be overcome by adjusting the level of neck resection. Therefore, it would appear that there is a limited role for gender specific implants for total hip arthroplasty.Keywords: hip arthroplasty modular stem gender