Preoperative Templating Research Articles

Imaging in Hip Arthroplasty Management-Part 1: Templating: Past, Present and Future.

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient’s normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

Preoperative templating in orthopaedic fracture surgery: The past, present and future

Preoperative planning in orthopaedic fracture surgery corroborates with the goal of establishing the best possible surgical result and ensuring a functioning limb for the patient. From placing sketches on overhead projector paper and measuring lengths from anatomical landmarks, ways of preoperative planning have evolved rapidly over the last 100 years. Today, preoperative planning includes methods such as advanced 3-Dimensional (3D) printed models and software programs incorporating entire libraries of osteosynthesis materials that can be shaped and rotated to fit a patient's specific anatomy. Relevant literature was evaluated to review the development of preoperative templating from the past and present, in order to assess its impact on the future of osteosynthesis.We identified studies on 3D-imaging, computer-assisted systems, and 3D-printed fractured bones and drill guides. The use of some of these systems resulted in a reduction in operation time, blood loss, perioperative fluoroscopy and hospital stay, as well as better placement of osteosynthesis material. Only few studies have identified differences in patient morbidity and mortality. Future techniques of preoperative templating are on the rise and the potential is vast. The cost-effectiveness and usefulness of certain methods need to be evaluated further, but the benefit of preoperative templating has the potential of being revolutionary, with the possibility of radical advances within orthopaedic surgery.

Can the intra-operative measurement of the diameter of the femoral head help surgeons to choose the best size of the acetabular cup?

PurposeWe hypothesized that the intra-operative measurement of the femoral head may increase the accuracy of the acetabular cup size optimal selection in total hip arthroplasty (THA). The purpose of this clinical research was to analyze the correlation between the estimated cup size from intra-operative measurement of the femoral head and the pre-operative templated cup size.MethodsA prospective observational single-center study was conducted from June 2019 to January 2020 including primary THA (n = 100). All cases were pre-operatively templated. The measurement of the anterior–posterior diameter of the femoral head was routinely intra-operatively performed. Any definitive implanted cup was considered as “oversized” when the size was > 4 mm than the diameter of the native head.ResultsThe median (interquartile range) size of the implanted cup, pre-operative planned cup size, and diameter of the femoral head were measured 52 (50–54) mm, 50 (48–54) mm and 49 (45–51) mm, respectively. Pre-operative planned size cup accurately predicted the implanted cup or differed in only one size (2 mm) in 77 (78%) cases. Otherwise, intra-operative femoral head measurement method accurately predicted the implanted or differed in only one size (2 mm) in 51 (87%) cases (p = 0.097).ConclusionThe intra-operative femoral head measurement is a simple and reliable tool to help the surgeons choose the best size of the acetabular cup and is as reliable as the pre-operative templating in order to avoid cup oversizing in THA. Utmost caution is warranted whenever the cup reamer is > 4 mm than the anterior–posterior diameter of the native head.

Comparison of Exeter stem offset size for total hip arthroplasty between males and females: A retrospective series of 780 hips

BackgroundMany orthopaedic surgeons use a ‘standard’ stem offset length, typically 37.5 mm and 44 mm for females and males respectively, in total hip arthroplasty. With increasingly personalized surgery, ‘standard’ one-size-fits-all stem lengths may be outdated. This study aims to test whether pre-operative templating affects stem length choice and whether ‘standard’ stem sizes are therefore outdated. MethodsWe performed a retrospective chart review of all total hip arthroplasty patients using Stryker's Exeter cemented femoral hip system in our centre between 2016 and 2020. Demographic and surgical data were collected. Data from surgeons who templated pre-operatively were compared to data from those who did not. Results780 patients were included (309 male, 471 female), average age 71.4 years (range 23–96). We found a significant difference between male and female offset lengths; more males had an offset length of 44 mm and more females had an offset length of 37.5 mm (p = 0.004). Among surgeons who did not template pre-operatively, 20.6% of female patients and 10.3% of male patients had other ‘non-standard’ offset lengths. Among surgeons who did template pre-operatively, the proportion of both female and male patients who had other ‘non-standard’ offset lengths was significantly higher (43.1% and 23.4%, respectively p < 0.05) ConclusionsThe difference between templating and non-templating surgeons' stem choice revealed significant individual variability between males and females. ‘Standard’ offset lengths for males and females were still used in the majority of our cohort. However, with the emergence of mainstream robotic arthroplasty, we feel that pre-operative templating has become a minimum standard.

Effects of pelvic obliquity and limb position on radiographic leg length discrepancy measurement: a Sawbones model

PurposePotential sources of inaccuracy in leg length discrepancy (LLD) measurements commonly arise due to postural malalignment during radiograph acquisition. Preoperative planning techniques for total hip arthroplasty (THA) are particularly susceptible to this inaccuracy, as they often rely solely on radiographic assessments. Owing to the extensive variety of pathologies that are associated with LLD, an understanding of the influence of malpositioning on LLD measurement is crucial. In the present study, we sought to characterize the effects of varying degrees of lateral pelvic obliquity (PO) and mediolateral limb movement in the coronal plane on LLD measurement error (ME).MethodsA 3-D sawbones model of the pelvis with bilateral femurs of equal-length was assembled. Anteroposterior pelvic radiographs were captured at various levels of PO: 0°, 5°, 10°, and 15°. At each level of PO, femurs were individually rotated medio-laterally to produce 0°, 5°, 10°, and 15° of abduction/adduction. LLD was measured radiographically at each position combination. For all cases of PO, the right-side of the pelvis was designated as the higher-side, and the left as the lower-side.ResultsAt 0° PO, 71% of tested variations in femoral abduction/adduction resulted in LLD ME < 0.5-cm, while 29% were ≥ 0.5-cm, but < 1-cm. ME increased progressively as one limb was further abducted while the contralateral limb was simultaneously further adducted. The highest ME occurred with one femur abducted 15° and the other adducted 15°. Similar magnitudes of ME were seen in 98% of tested femoral positions at 5° of PO. The greatest ME (~ 1 cm) occurred at the extremes of right-femur abduction and left-femur adduction. At 10° of PO, a higher prevalence of cases exhibited LLD ME > 0.5-cm (39%) and ≥ 1-cm (8%). The greatest errors occurred at femoral positions similar to those seen at 5° of PO. At 15° of PO, half of tested variations in femoral position resulted in LLD ME > 1-cm, while 22% of cases produced errors > 1.5-cm. These clinically significant errors occurred at all tested variations of right-femur abduction, with the left-femur in either neutral position, abduction, or adduction.ConclusionThis study aids surgeons in understanding the magnitude of radiographic LLD ME produced by varying degrees of PO and femoral abduction/adduction. At a PO of ≤5°, variations in femoral abduction/adduction of up to 15° produce errors of marginal clinical significance. At PO of 10° or 15°, even small changes in mediolateral limb position led to clinically significant ME (> 1-cm). This study also highlights the importance of proper patient positioning during radiograph acquisition, demonstrating the need for surgeons to assess the quality of their radiographs before performing preoperative templating for THA, and accounting for PO (> 5°) when considering the validity of LLD measurements.

The impact of femoral bone quality on cementless total hip pre-operative templating.

Accurate templating is an integral part of pre-operative planning for total hip arthroplasty (THA). Templating of cementless implant accuracy has been average. The aim of this study was to assess the impact of Dorr femoral classification on the accuracy of pre-operative digital templating. This was a retrospective study of cementless THA pre-operative planning using one implant design. A total of 210 primary THA were reviewed. A total of 102 cementless THAs matched the exclusion and inclusion criteria, using one implant combination, were analyzed by an orthopaedic resident and a fellowship trained arthroplasty surgeon. Each x-ray was evaluated and assigned a femoral Dorr classification. Accuracy of templating was determined by comparing the templated size with the actual implant size both for the femoral and acetabular components. Out of the 102 cases, exact templating size was achieved in 35.3% for the acetabulum, 25.5% for the femur, and only in 9.8% for both components. Reasonable templating, ± one of the actual size, was achieved in 78.4% for the acetabulum, 74.5% for the femur, and 60.8% for both components. Use of Dorr femoral type classification did not result in better templating accuracy. Pre-operative hip cementless templating using digital x-rays with double marker method do not improve accuracy compared to other methods available for templating. Accounting for bone quality using the Dorr femoral classification did not improve accuracy.

A new understanding of radiographic landmarks of the greater trochanter that indicate correct femoral rotation for measurement of femoral offset

ObjectivesTo establish and validate a novel method for aligning femoral rotation to accurately measure femoral offset for preoperative templating and component sizing, and to identify the physical location of two radiographic lines utilized in the described method.Materials and methodsCadaveric proximal femurs were skeletonized and mounted to a biaxial load frame. Two radiographic lines along the greater trochanter were identified fluoroscopically. The femurs were rotated, and images were taken when the lines appeared superimposed, then in 2-degree increments to 10° of internal and external rotation, and at 30°. Radiographic femoral offset was calculated at each angle, and the maximum and aligned offsets were compared. Bone was removed until the radiographic lines disappeared, then a metal wire was inserted in place of the bone to confirm that the lines reappeared.ResultsThe physical locations of the radiographic landmarks were on the anterior and posterior aspects of the greater trochanter. The mean true femoral offset was 38.2 mm (range, 30.5–46.3 mm). The mean aligned femoral offset was 37.3 mm (range, 29.3–46.3 mm), a 2.4% underestimation. The mean angle between aligned and true offset was 3.6° of external rotation (range, 10°ER-8°IR). Intra-rater intraclass correlation coefficient was 0.991.ConclusionAlignment of the radiographic lines created by the anterior and posterior aspects of the greater trochanter is a reliable and accurate rotational positioning method for measuring true femoral offset when using plain films or fluoroscopy, which can aid surgeons with preoperative templating and intraoperative component placement for total hip arthroplasty.

The influence of computed tomography preoperative planning on clinical outcomes after anatomic total shoulder arthroplasty: a matched cohort analysis

BackgroundEvaluation, characterization, and correction of glenoid deformity are an important part of performing anatomic total shoulder arthroplasty (TSA). Three-dimensional computed tomography (3D CT) planning has been shown to improve implant position, but the impact on clinical outcomes is less clear. The purpose of the current study is to compare clinical outcomes of TSA performed with 3D CT preoperative planning with matched controls performed without CT-based planning. MethodsUtilizing a multicenter shoulder arthroplasty registry, patients who underwent a TSA with 2-year clinical follow-up were retrospectively identified. These patients were divided into two cohorts based on technique for glenoid guide pin placement based on surgeon preference: 1) those who utilized 3D preoperative templating with or without patient-specific instrumentation (PSI) and 2) a control group of TSAs performed without 3D CT preoperative planning. The two groups were matched 1:1 based on age, sex, and baseline American Shoulder and Elbow Surgeons (ASES) score. Patient-reported outcomes and active range of motion (ROM) obtained at 2 years postoperatively were assessed and compared between the two cohorts. A subgroup analysis was also performed comparing outcomes in patients with 3D CT preoperative planning with and without PSI. ResultsData collection was performed on 84 study patients with 3D CT preoperative planning (51 with PSI and 33 without) and 84 matched control patients without CT-based planning (168 patients in total). Baseline characteristics were similar between the groups. Improvement from baseline for the ASES score (study group: 45.4, controls: 39.0, P = .029) and external rotation at 90° of abduction (study group: 42° vs. 29°, P = .009) was significantly greater in the CT-based planning group than that in matched controls. There were no other significant differences in improvement in outcomes or ROM between the two groups. Within the 3D CT cohort, there were no significant differences in patient-reported outcomes or ROM between TSAs performed with or without PSI. A significantly greater percentage of patients with 3D CT planning achieved a patient acceptable symptomatic state than controls (89% vs. 75%, P = .016). ConclusionTSAs performed with 3D CT preoperative glenoid planning with or without utilization of PSI were associated with statistically significantly greater improvement from baseline in ASES scores and external rotation at 90° of abduction than TSA performed without 3D CT planning. The clinical significance of this finding is unclear, as the differences failed to meet a clinically significant threshold.

Accuracy of digital templating in uncemented primary total hip arthroplasty: which factors are associated with accuracy of preoperative planning?

Preoperative planning is a fundamental step for successful total hip arthroplasty (THA). Studies have highlighted the accuracy of preoperative digital templating for estimating acetabular cup and stem size. Stem design such as single-wedge metadiaphyseal (Type 1 stem) versus mid-short stem (microplasty) and surgical approach (anterior, direct lateral or posterior) have not been well investigated as predictors of THA templating accuracy. 204 patients (220 hips) who had undergone elective THA between November 2016 and December 2019 and presented a saved preoperative template were retrospectively reviewed. Templates from 5 different surgeons were involved in the analysis. 3 different approaches were used: direct lateral (DL), posterior (PA), direct anterior (DAA). 2 different stem designs were used: single-wedge metadiaphyseal and single-wedge mid-short (Biomet Taperloc Microplasty), while the acetabular component remained the same. Bivariate and multivariate regression analyses were performed to determine predictors of accuracy. Femoral component size templating accuracy was significantly improved when using the single-wedge mid-short stem (Taperloc Microplasty) design when performing bivariate analysis. Although accuracy of cup sizing was not affected by approach, precision was significantly better in the PA group (p < 0.05). Accuracy of templating was found to be independent of BMI and gender but dependent on presence of calibration marker and stem design (p < 0.05). When striving for improved templating accuracy, acetabular and femoral component accuracy were best achieved using a calibration marker and a metaphyseal short femoral stem design.

Determining the accuracy of preoperative total hip replacement 2D templating using the mediCAD\xae software

BackgroundTemplating is a preoperative planning procedure that improves the efficiency of the surgical process and reduces postoperative complications of total hip arthroplasty (THA) by improving the precision of prediction of prosthetic implant size. This study aimed to evaluate the accuracy of the preoperative cup and stem size digital 2D templating of THA with mediCAD® software and find the factors that influence the accuracy, such as indication for surgery, patients’ demographics, implant brand, and the assessors’ grade of education.MethodsWe retrospectively retrieved 420 patient template images of all patients who underwent THA between March 2018 and March 2021. Templating of all included images was processed using mediCAD® software a day before surgery by a newcomer physician to hip arthroplasty course (PGY-2 orthopedic resident or hip surgery fellow). Preoperative templating cup and stem sizes were compared with the actual inserted implant sizes.ResultAfter excluding ineligible patients, this study included 391 patients, 193 (49.4%) males and 198 (50.6%) females with a mean age of 43.3 ± 14.9. The average cup sizes predicted before and after surgery were 52.12 ± 14.28 and 52.21 ± 15.05 respectively, and the mean delta cup size (before and after surgery) was 2.79 ± 2.94. The delta stem size before and after surgery has a mean value of 1.53 ± 1.49. The acetabular cup components, measured within ± 0, ± 1, and ± 2 sizes, were 28.9%, 63.9%, 83.1% accurate, respectively. The femoral stem design component measured within ± 0, ± 1, and ± 2 sizes were 27.2%, 61.0%, 78.6% accurate, respectively. Wagner Cone® stem brand, DDH patients, and females showed significantly higher accuracy of stem size templating. Revision THA has the lowest accuracy in terms of cup size templating. The compression of accuracy rate between resident and fellow revealed no significant differences. Also, no significant difference was detected between the accuracy of templating performed in the first months with the second months of the arthroplasty course period.ConclusionOur study showed that under mentioned condition, templating using mediCAD® has acceptable accuracy in predicting the sizes of femoral and acetabular components in THA patients. Digital software like mediCAD® remains favorable because of the short learning curve, user-friendly features, and low-cost maintenance, leading to level-up patient care and THA efficacy. Further studies are necessary for clarifying the role of the assessor’s experience and expertise in THA preoperative templating.Level of evidenceLevel III (retrospective observational study).

Pre-operative templating in THA using a short stem system: precision and accuracy of 2D versus 3D planning method

BackgroundTotal hip arthroplasty (THA) is the most successful orthopaedic surgery of the past century. The current study aimed to compare the accuracy of digital planning using 2D versus 3D templating.Materials and methodsNinety-five THAs in 90 patients were included in the current study. Pre- and post-operative X-rays (in two planes) and low-dose rotation computed tomography scans from hip to foot were performed. Paired t-test and regression analyses were conducted to compare 2D and 3D templating accuracy of the definitive implant.ResultsCup size planned both with 2D (p < 0.0001) and 3D (p = 0.012) templating was significantly different from the definitively used cup size. The difference between the 2D-planned and implanted stem size (p < 0.0001) was statistically significant. In contrast, there were no significant differences in the 3D-planned and implanted stem size (p = 0.181). Three-dimensional templating showed significantly higher accuracy than 2D templating in terms of cup size (1.1 ± 1.4 versus 1.7 ± 1.8; p = 0.007) and stem size (0.3 ± 0.6 versus 0.7 ± 0.7; p < 0.0001).With increasing body mass index (BMI), 2D templating of the stem became more inaccurate (p = 0.041). Remarkably, 3D templating remained accurate for all components (stem, p = 0.533; cup, p = 0.479) despite increasing BMI.ConclusionDespite extended planning time and increased exposure to radiation, 3D-based planning showed higher accuracy than 2D templating, especially in obese patients. On the basis of our results, we believe that 3D-based pre-operative planning in THA is justifiable and beneficial in patients with increased BMI.Level of EvidenceIII.

More than a feeling?—Overruling the preoperatively templated offset option leads to a minor offset increase in short stem total hip arthroplasty

PurposeShort stems are increasingly used in total hip arthroplasty (THA) because of advantages in bone and soft tissue preservation and reconstruction of hip geometry. Digital templating is essential in determining the correct offset option and stem size in THA. However, the preoperative template sizes might be intraoperatively overruled.Patients and methodsWe evaluated the effect of intraoperative overruling of the preoperatively templated offset option of a short curved stem on hip offset, leg length, implant positioning, and femoral canal fill index. The overruling was performed in case of intraoperative instability, telescoping, or both. A series of 1052 consecutive THAs with a cementless short curved stem and press-fit cup was retrospectively screened. One hundred patients with unilateral THA and a contralateral native and morphologically healthy hip as a reference met the inclusion criteria. Measurements were carried out on preoperative and 3 months anterior–posterior postoperative radiographs. Patients were divided according to the overruling by offset option or stem size.ResultsHip offset was increased in all groups, but only with significant increase if an offset option + 1 was used intraoperatively (p = 0.025). LLD was restored without significance in all groups (p = 0.323; p = 0.157).ConclusionIntraoperative overruling of the preoperative digital template in cementless short stem total hip arthroplasty results in an increase of hip offset compared to a contralateral healthy hip. However, the increase is marginal and clearly under 5 mm compared to the contralateral healthy hip.

Comparison of hip offset and rotation center reconstruction between robot-assisted and manual total hip arthroplasty

Objective: To compare the differences of hip offset and rotation center reconstruction between robot-assisted and manual total hip arthroplasty (THA). Methods: Patients underwent robot-assisted and manual THA from May to September of 2020 in the First Affiliated Hospital of Chongqing Medical University were enrolled in this study. The patients included 27 patients (28 hips) in robot-assisted THA (rTHA) group and 29 patients (31 hips) in manual THA (mTHA) group. In rTHA group, there were 16 males and 11 females, with a mean age of (59±13) years. In mTHA group, there were 18 males and 11 females, with a mean age of (63±14) years. Basic information, including gender, age, body mass index (BMI), diagnosis and functional scoring etc, were recorded. In rTHA group, Mako robot system was used for preoperative planning, intraoperative real-time location and navigation. In mTHA group, traditional preoperative template design and surgical procedure were carried out. Operation time and functional scoring were compared postoperatively. Femoral offset, acetabular offset, global offset, rotation center changes in vertical and horizontal directions were measured on pelvis X-ray and analyzed. The correlation between intraoperative feedback of global offset change in robot system and postoperative measured global offset were analyzed. Results: Operation time in rTHA group was (80±10) min, which was statistically longer than that in mTHA group ((58±18) min, P<0.001). With 6 months' follow-up, the Harris scoring in rTHA group was 94.9±2.8, which was statistically higher than that in mTHA group (93.1±2.8, P=0.017), however there was no statistic difference in WOMAC scoring between rTHA and mTHA group (7.0±3.8 vs 7.1±2.4, P=0.840). Absolute global offset change within 5 mm, 5-10 mm and lager than 10 mm were 71.4%(20/28), 28.6%(8/28) and 0 in rTHA group, which were 45.2%(14/31), 29.0%(9/31) and 25.8%(8/31) in mTHA group (all P<0.05). A positive relation was found between intraoperative feedback of global offset change in robot system and postoperative measured global offset in rTHA group (r=0.77, P<0.001). It was found that rotation center changes concentrated in outer upper quadrant in both groups, and rotation center change in rTHA group concentrated mainly in the area less than 10 mm, however, rotation center change in mTHA group was more dispersive compared with rTHA group. Conclusion: rTHA may accurately reconstruct hip offset and rotation center, intraoperation feedback of global offset change may be an effective reference.

Anatomic Total Shoulder Arthroplasty: Component Size Prediction with 3-Dimensional Pre-Operative Digital Planning.

BackgroundThe rate, complexity, and cost of total shoulder arthroplasty (TSA) continues to grow. Technology has advanced pre-operative templating. Reducing cost of TSA has positive impact for the patient, manufacturer, and hospital. The aim of this study was to evaluate the accuracy of implant size selection based on 3-D templating. Our hypothesis was that pre-operative templating would enable accurate implant prediction within one size.MethodsMulticenter retrospective study of anatomic TSAs templated utilizing 3-D virtual planning technology. This program uses computed tomography (CT) scans allowing the surgeon to predict component sizes of the glenoid and humeral head and stem. Pre-operative templated implant size were compared to actual implant size at the time of surgery. Primary data analysis utilized unweighted Cohen's Kappa test.Results111 TSAs were analyzed from five surgeons. Pre-operative templated glenoid sizes were within one size of actual implant in 99% and exactly matched in 89%. For patients requiring a posterior glenoid augment (n = 14), 100% of implants were within one size of the template and 93% matched exactly. For stemless humeral components (n = 87) implanted, 98% matched the pre-operative template within one size with 79% exactly matched. For stemmed components (n = 24), 88% of cases were within one size of the preoperative plan and exactly matching in 83%. Humeral head diameter matched within one size of the pre-operative template in 84% of cases and exactly matched in 72%.ConclusionPre-operative 3-D templating for TSAs can accurately predict glenoid and humeral component size. This study sets the groundwork for utilization of pre-operative 3-D templating as a potential method to reduce overall TSA costs by managing cost of implants, reducing inventory needs, and improving surgical efficiency.

Effect of body mass index on the conventional method of templating in uncemented total hip arthroplasty: A prospective study

BACKGROUND: Preoperative templating is an important step in total hip arthroplasty (THA). Results of traditional as well as digital method of templating are well established in various studies. Very few studies have evaluated the effect of body mass index (BMI) and gender on templating. Our study was undertaken to evaluate the effect of BMI and gender in accurate size estimation in uncemented THA components by conventional method of templating. MATERIALS AND METHODS: Preoperative radiographs were templated for 60 patients who underwent primary uncemented THA. BMI and gender of patients were noted during preoperative evaluation. Patients were grouped as per gender and divided into three groups as per BMI (underweight <18.5, normal 18.5-24.9, overweight >25). The estimated preoperative template size was compared with the actual implant size used. P-value of <0.05 was considered to be significant. RESULTS: Acetabular component was exactly templated in 63.33% and femoral component in 76.6% cases. Gender and BMI had no statistical difference in component size prediction. Post-operative analysis of THA performed showed statistically significant association between high BMI and limb length discrepancy and restoration of femoral offset. CONCLUSION: In our study, we found that femoral component is more accurately predicted. No statistically significant effect of gender and BMI was seen in accuracy of conventional method of templating in implant size estimation. However, BMI is found to affect limb length assessment during surgery and restoration of femoral offset.

Incidental Pulmonary Nodules Found on Shoulder Arthroplasty Preoperative CT Scans.

With current emphasis on preoperative templating of anatomical and reverse shoulder arthroplasty (aTSA and rTSA, respectively), patients often receive thin slice (<1.0 mm) computerized tomography (CT) scans of the operative shoulder, which includes about two-thirds of the ipsilateral lung. The purpose of this study is to evaluate the prevalence and management of incidentally detected pulmonary nodules on preoperative CT scans for shoulder arthroplasty. In this single-center retrospective study, we queried records of aTSA and rTSA patients from 2015 to 2020 who received preoperative CT imaging of the shoulder. Compared to patients with negative CT findings, there were significantly more females (63.8% vs. 46.4%; P = .011), COPD (13.0% vs. 4.7%; P = .015), and asthma (18.8% vs. 6.9%; P = .003) among the patients with incidental nodules on CT. Binary logistic regression confirmed that female sex (odds ratio = 2.00; 95% CI = 1.04 to 3.88; P = .037), COPD history (OR = 3.02; 95% CI = 1.05 to 8.65; P = .040), and asthma history (OR = 3.17; 95% CI = 1.30 to 7.77; P = .011) were significantly associated with an incidental nodule finding. Incidental pulmonary nodules found on shoulder arthroplasty preoperative CT scans are often low risk in size with low risk of malignancy, and do not require further workup. This study may provide guidance to orthopedic surgeons on how to manage patients with incidental pulmonary nodules to increase chances of early cancer detection, avoid unnecessary referrals, reduce potentially harmful radiation exposure of serial CT scans, and improve cost efficiency.

A PROSPECTIVE STUDY ANALYSIS OF LIMB LENGTH DISCREPANCY FOLLOWING TOTAL HIP ARTHROPLASTY

Objective: The present study was designed and implemented to assess the incidence and occurrence of LLD in post-hip arthroplasty and also to evaluate the causes of limb length discrepancy both intra- and post-operative period to manage total hip arthroplasty effectively. Methods: It is a prospective study involving 52 patients underwent for THA and conducted in the Department of Orthopedics, Tertiary Care Hospital, Visakhapatnam, India from the period of January 2013 to December 2019. The study used Southern approach or “Moore” approach. All the patients are assessed for limb length discrepancy immediately after the surgery and followed at 6 weeks, 3 months, and after 6 years. Results: Three patients had significant limb length discrepancy among the 52 patients (5.77%) while the remaining had no significant discrepancies in all X-rays which assess the radiological discrepancies in length. The study yields a satisfactory result as very few patients reported LLD during follow-up period and outcomes such as pain alleviation, walking capacity, limping, and patient satisfaction were insignificantly influenced by leg lengthening (p≤0.05). Conclusion: A combination of pre-operative templating, intra-operative marking and usage of intra-operative image intensifier and an understanding of anatomy, biomechanics of hip, and implant design would reduce the error of limb length discrepancy.

KingMark's dual-marker versus a conventional single-marker templating system: is there a difference in accuracy of predicting final implant sizes and leg lengths?

Pre-operative templating for total hip replacement (THR) surgery leads to more accurate implant sizing and positioning. This study aimed to compare the KingMark™ dual-marker system for magnification calibration to the current gold standard single-marker system in accuracy of predicting implant size and restoration of leg length post-operatively. This is a retrospective analysis of patients who had primary THR surgery from 2013 to 2019 by a single surgeon. Patients were in two cohorts whose operations were completed at separate healthcare facilities. Patients in the first cohort had pre-operative templating using the KingMark system; patients in the second cohort had templating using a single-marker. For all patients, pre-operative radiographs were reviewed; predicted implants noted; and leg length discrepancies calculated. These were compared to post-operative data. We then tested the null hypothesis that there was no difference between the templating methods for prediction accuracy of implant size and achieving restoration of leg length. A total of 121 patients were included in the KingMark cohort, and 104 were included in the single-marker cohort. In the KingMark cohort, 83.5% of patients had implantation of a cup within one size of that predicted, compared to 71.2% of the single-marker cohort. This superiority was statistically significant. There was a greater proportion of exact cup size predictions in the KingMark cohort, but this was not statistically significant. We did not find any significant difference between the cohorts for stem size, or stem placement, or reduction of leg length discrepancy. We have demonstrated statistically significant superiority of the KingMark over a single-marker templating system for predicting cup size in primary THR surgery. For post-operative restoration of leg length, our study did not show any advantage of KingMark templating compared to single-marker templating.

Perioperative work in shoulder arthroplasty is undervalued by Relative Value Scale Update Committee methodology: quantifying shoulder arthroplasty workload in a single surgeon’s practice

BackgroundThe Center for Medicare and Medicaid Services (CMS) quantifies the total work associated with procedures based on recommendations from the Relative Value Scale Update Committee (RUC). To determine the amount of work for a procedure, the RUC relies on data gathered via surveys from practicing physicians. Investigation of the accuracy of the RUC’s estimates of physician work has shown that there are discrepancies between the RUC times used to calculate work and times determined objectively. The purpose of this study was to determine the accuracy of the RUC and CMS’s current times and work relative value units (wRVUs) for the perioperative work involved regarding shoulder arthroplasty. MethodsThe RUC was contacted to obtain a list of perioperative tasks for shoulder arthroplasty surgeries. The tasks that occurred outside of the operating room were timed as the event occurred, whereas times for tasks performed inside the operating room were determined from the electronic medical record. Each task’s time was then multiplied by its respective CMS-assigned intensity coefficient to calculate the wRVU. ResultsThe tasks timed in this study were allotted 105 minutes by the RUC and a total wRVU of 2.1. Our study found that these same tasks took 119.5 minutes and had a total wRVU of 2.4. The overall time it takes to perform perioperative tasks in shoulder arthroplasty surgeries is underestimated by 14.5 minutes, resulting in an undervaluation of the wRVU by 0.3. ConclusionThe perioperative work associated with shoulder arthroplasty surgeries is underestimated by the RUC and CMS’s. The RUC and CMS should consider using prospective, empiric times when calculating physician work as it is a more accurate measurement than the current method used. This discrepancy is expected to be amplified with increased preoperative templating and utilization of technological advancements in arthroplasty. Further study is needed on a broader national or international level to determine if this discrepancy exists systemically.

The accuracy of digital templating in cementless total hip arthroplasty in dysplastic hips

BackgroundTotal hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) is a complex procedure due to associated anatomical abnormalities. We studied the extent to which preoperative digital templating is reliable when performing cementless THA in patients with DDH.MethodsWe templated and compared the pre- and postoperative sizes of the acetabular and femoral components and the center of rotation (COR), and analysed the postoperative cup coverage, leg length discrepancy (LLD), and stem alignment in 50 patients (56 hips) with DDH treated with THA.ResultsThe implant size exactly matched the template size in 42.9% of cases for the acetabular component and in 38.2% of cases for the femoral component, whereas the templated ±1 size was used in 80.4 and 81.8% of cases for the acetabular and femoral components, respectively. There were no statistically significant differences between templated and used component sizes among different DDH severity levels (acetabular cup: p = 0.30 under the Crowe classification and p = 0.94 under the Hartofilakidis classification; femoral stem: p = 0.98 and p = 0.74, respectively). There were no statistically significant differences between the planned and postoperative COR (p = 0.14 horizontally and p = 0.52 vertically). The median postoperative LLD was 7 (range 0–37) mm.ConclusionDigital preoperative templating is reliable in the planning of cementless THA in patients with DDH.