Postoperative Alignment Parameters Research Articles

Caliper-verified unrestricted kinematically aligned total knee arthroplasty in Asian patients showed efficacious mid- to long-term results regardless of postoperative alignment categories.

There have been insufficient data regarding the long-term results of unrestricted kinematically aligned total knee arthroplasty (unKATKA) in Asian patients. We investigated mid- to long-term clinical and radiological follow-up data of Korean patients after caliper-verified unKATKA of minimum 7.4-10 years includingcategorised data of postoperative tibial component, limb and knee alignment. Additionally, we analysed the preoperative distribution and postoperative restoration of coronal plane alignment of knee (CPAK) phenotypes. This study is a retrospective analysis of 63 patients:96 osteoarthritic underwent consecutive caliper-verified unKATKA between October 2013 and May 2016 by a single surgeon. Implant survivorship was investigated for revision for any reason. Each knee was categorised into an in-range or outlier group by three postoperative alignment parameters: tibial component, knee and limb alignment. Statistical analyses were done for any significant differences in clinical scores and implant survival rates between groups. Finally, all knees were classified into CPAK classification postoperatively and postoperatively. The CPAK restoration rate was calculated. Among 85 knees in the clinically confirmed group, implant survival was 98.8%. There was one case of revision due to periprosthetic fracture. The percentage postoperatively aligned in the varus (valgus) outlier range was 100% (0%) for tibial component, 16.7% (24.8%) for the knee alignmentand 51% (0%) for the limb alignment. All three categories did not affect implant survival or clinical scores. Eighty one out of 96 knees (84.4%) were restored to their CPAK phenotype postoperatively. With the limitation of a case series having a small number of patients and gender deviation, our study suggests that caliper-verified unKATKA could be a good option regardless of geographical variation of constitutional alignment in patients with osteoarthritis (OA). Level IV, therapeutic study.

An observational study on the functional outcomes of 100 robotic total knee replacements performed by an Indian surgeon: Early experiences

Abstract Background: We aim to share our preliminary encounter with robotic knee replacements in Indian patients, focusing on the initial 100 cases. This report will delve into our observations regarding the learning curve and provide insights from a short-term follow-up at 6 months. Materials and Methods: Following institutional ethical clearance, we conducted an observational study involving 100 robotic-assisted total knee replacement cases performed from March 2022 to November 2022. These patients underwent a 6-month follow-up to evaluate functional outcomes. Our primary objective was to investigate the learning curve associated with robotic-assisted total knee arthroplasty (RATKA), specifically emphasizing operative time. Furthermore, we examined preoperative and postoperative alignment parameters as part of our analysis. Results: In our investigation, participants had a mean age of 64.68 years, with a female-to-male ratio of 43:22 and an average body mass index of 30.71 ± 4.88. Intraoperative blood loss was recorded at an average of 91.81 ± 21.63 mL. The mean surgical duration for the initial 25 cases was 102.5 ± 11.08 min, which improved to 65.65 ± 13.07 min for the subsequent 75 cases. The average hospital stay length was 2.88 ± 0.88 days. Notably, there was a significant enhancement in the Knee Society Score (KSS), with a preoperative mean of 38.90 ± 12.72 improving to a postoperative mean of 84.89 ± 4.10 (P = 0.001), as well as in the Oxford Knee Score (OKS), which saw a rise from 16.62 ± 16.42 preoperatively to 45.58 ± 4.97 postoperatively (P = 0.001). The accuracy of preoperative determination for femoral component sizes was 100%, while for tibial component sizing, it was 97%. Conclusion: The key finding from this observational study suggests that around 25 procedures are required to reach a learning plateau. During this process, an average decrease of 36.1 min in surgical time was observed from the initial to proficient stages. Notably, no learning curve was observed for lower limb alignment and implant placement, and no significant complication rates were documented.

P109. Precontoured rods in achieving planned regional and global alignment: a lot of planning but does it matter in adult spinal deformity? A multicentered study

BACKGROUND CONTEXT The aim of complex spinal deformity correction is to restore both sagittal and coronal balance of the spine. Many studies have shown adverse clinical outcomes related to under and over corrected sagittal and coronal deformities. With proper surgical planning, such under and over correction can be mitigated and patient outcomes can be improved and other complications, such as PJK, can be minimized. PURPOSE Precontoured rod instrumentation for adult spinal deformity (ASD) can accurately achieve planned alignment parameters in the sagittal and coronal planes. STUDY DESIGN/SETTING Multicentered cohort. PATIENT SAMPLE Adult patients (age 18) undergoing instrumentation with pre-contoured rods from 2018-2021. OUTCOME MEASURES Sagittal parameters included C2 slope, cervical lordosis (CL), C2 pelvic angle (CPA), cervicothoracic pelvic angle (CTPA), lumbar lordosis (LL), pelvic incidence (PI), PI-LL, pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), T1 slope, T1 slope-CL (T1 slope-CL), thoracic kyphosis (TK), T1 pelvic angle (TPA), C2-C7 SVA (cSVA). Coronal parameters included major coronal curve (MCC) and coronal balance (CVA). METHODS A multicenter cohort of adult patients (age 18) undergoing instrumentation with pre-contoured rods was reviewed from 2018-2021. RESULTS A total of 289 patients were included in the study (mean age: 61.3±13.5yrs, 156 (54%) female, mean total instrumented levels: 8.2±5.0). At 6mo followup, the preoperative plan accurately predicted CL, MCC, and CVA with 71 (62.8%), 33 (68.6%) and 37 (69.8%) patients meeting acceptable criteria (ie, difference of ≤5° or ≤10mm), respectively. However, by 2yrs, accuracy in predicting regional parameters improved including LL (mean error: -3.9±10.2°; P=0.064), PI-LL (-2±9.1°; P=0.265), PT (0.05±5.7°; P=0.968), TK (-6.0±11.3°; 0.059). Similarly, mean errors for global parameters including T1SPI (-1.8±4.2°; 0.126), TPA (-1.8±5.7°, 0.233) and CVA (-1.4±16.8mm, 0.874) were low and statistically insignificant. Although mean differences between plan and 2yr postop for CPA, CTPA, SVA and cSVA were statistically significant, the mean error was 20mm, respectively proving a small clinical difference. CONCLUSIONS In the first and largest, multicenter study with 2-year followup evaluating use of pre-contoured rods, we found high accuracy for both coronal and sagittal correction (regionally and globally) in predicting postoperative alignment parameters. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. The aim of complex spinal deformity correction is to restore both sagittal and coronal balance of the spine. Many studies have shown adverse clinical outcomes related to under and over corrected sagittal and coronal deformities. With proper surgical planning, such under and over correction can be mitigated and patient outcomes can be improved and other complications, such as PJK, can be minimized. Precontoured rod instrumentation for adult spinal deformity (ASD) can accurately achieve planned alignment parameters in the sagittal and coronal planes. Multicentered cohort. Adult patients (age 18) undergoing instrumentation with pre-contoured rods from 2018-2021. Sagittal parameters included C2 slope, cervical lordosis (CL), C2 pelvic angle (CPA), cervicothoracic pelvic angle (CTPA), lumbar lordosis (LL), pelvic incidence (PI), PI-LL, pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), T1 slope, T1 slope-CL (T1 slope-CL), thoracic kyphosis (TK), T1 pelvic angle (TPA), C2-C7 SVA (cSVA). Coronal parameters included major coronal curve (MCC) and coronal balance (CVA). A multicenter cohort of adult patients (age 18) undergoing instrumentation with pre-contoured rods was reviewed from 2018-2021. A total of 289 patients were included in the study (mean age: 61.3±13.5yrs, 156 (54%) female, mean total instrumented levels: 8.2±5.0). At 6mo followup, the preoperative plan accurately predicted CL, MCC, and CVA with 71 (62.8%), 33 (68.6%) and 37 (69.8%) patients meeting acceptable criteria (ie, difference of ≤5° or ≤10mm), respectively. However, by 2yrs, accuracy in predicting regional parameters improved including LL (mean error: -3.9±10.2°; P=0.064), PI-LL (-2±9.1°; P=0.265), PT (0.05±5.7°; P=0.968), TK (-6.0±11.3°; 0.059). Similarly, mean errors for global parameters including T1SPI (-1.8±4.2°; 0.126), TPA (-1.8±5.7°, 0.233) and CVA (-1.4±16.8mm, 0.874) were low and statistically insignificant. Although mean differences between plan and 2yr postop for CPA, CTPA, SVA and cSVA were statistically significant, the mean error was 20mm, respectively proving a small clinical difference. In the first and largest, multicenter study with 2-year followup evaluating use of pre-contoured rods, we found high accuracy for both coronal and sagittal correction (regionally and globally) in predicting postoperative alignment parameters.

Bone Ninja application is reliable alternative to PACS in measuring preoperative and postoperative alignment parameters of total knee arthroplasty

BackgroundA picture archiving and communication system (PACS) is a means wherein the images are acquired, displayed, transmitted, and stored digitally. Bone Ninja is an application on iPad (Apple Inc.) on the IOS platform, developed as a teaching tool for deformity corrections around the knee. The principal objective of this study is to determine the reliability and consistency of Bone Ninja application in measuring the preoperative and postoperative alignment in patients undergoing a total knee arthroplasty and compare it with the PACS. MethodsThis retrospective cross-sectional study was done using preoperative and postoperative leg-length radiographs of 50 consecutive patients (50 knees) who underwent unilateral total knee arthroplasty. Using Bone Ninja application and PACS, preoperative Lateral Distal Femoral Angle (LDFA), Tibiofemoral Angle (TFA), Medial Proximal Tibial Angle (MPTA) and postoperative Tibial alignment angle (TAA), Tibiofemoral angle (TFA), Femoral alignment angle (FAA) were measured independently by three doctors (two orthopedists and one radiologist). The measurements were repeated after an interval to determine intra and interobserver reliability. ResultsBoth preoperative (TFA, LDFA, MPTA) and postoperative measurements (TFA, TAA, FAA) showed highly correlated intraobserver and interobserver correlation coefficients. Cohen kappa values for all the measurements were greater than 0.80 but the values were higher for PACS compared to Bone Ninja application. ConclusionsPACS remains the gold standard, but bone ninja application is a reliable alternative for preoperative and postoperative alignment measures in total knee arthroplasty where PACS is not available.

Association of findings on preoperative extension lateral cervical radiography with osteotomy type, approach, and postoperative cervical alignment after cervical deformity surgery.

The authors' objective was to determine whether preoperative lateral extension cervical spine radiography can be used to predict osteotomy type and postoperative alignment parameters after cervical spine deformity surgery. A total of 106 patients with cervical spine deformity were reviewed. Radiographic parameters on preoperative cervical neutral and extension lateral radiography were compared with 3-month postoperative radiographic alignment parameters. The parameters included T1 slope, C2 slope, C2-7 cervical lordosis, cervical sagittal vertical axis, and T1 slope minus cervical lordosis. Associations of radiographic parameters with osteotomy type and surgical approach were also assessed. On extension lateral radiography, patients who underwent lower grade osteotomy had significantly lower T1 slope, T1 slope minus cervical lordosis, cervical sagittal vertical axis, and C2 slope. Patients who achieved more normal parameters on extension lateral radiography were more likely to undergo surgery via an anterior approach. Although baseline parameters were significantly different between neutral lateral and extension lateral radiographs, 3-month postoperative lateral and preoperative extension lateral radiographs were statistically similar for T1 slope minus cervical lordosis and C2 slope. Radiographic parameters on preoperative extension lateral radiography were significantly associated with surgical approach and osteotomy grade and were similar to those on 3-month postoperative lateral radiography. These results demonstrated that extension lateral radiography is useful for preoperative planning and predicting postoperative alignment.

Evaluating the Impact of Social Deprivation on Mid-Term Outcomes Following Distal Radius Open Reduction Internal Fixation

PurposeAlthough baseline biopsychosocial factors are associated with short-term patient-reported outcomes following distal radius fracture open reduction internal fixation (ORIF), their effect on mid-term outcomes is unclear. We aimed to evaluate the effect of social deprivation, previously established as a surrogate for depression, pain interference, and anxiety, on quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores >1 year following distal radius ORIF.MethodsAdult patients (≥18 years) with an isolated distal radius fracture treated with ORIF by orthopedic trauma and hand surgeons at a single tertiary academic center over a 3-year period were included. Outcomes at ≥1 year postoperatively were evaluated using QuickDASH. Age, follow-up duration, area deprivation index (ADI; a measure of social deprivation), subspecialty (hand vs trauma), and postoperative alignment were assessed using linear regression with 95% confidence intervals after bootstrapping and a permutation test for P values to test for their association with the final QuickDASH score.ResultsFollow-up data were obtained for 98 of 220 (44.5%) patients at a mean of 3.1 ± 1.0 years after surgery. Mean age and ADI were 53.2 ± 15.4 years and 26.8 ± 18.7, respectively. Most fractures were intra-articular (67.3%), and 72.4% had acceptable postoperative alignment parameters, as defined by the American Academy of Orthopaedic Surgeons clinical practice guidelines. The mean QuickDASH score was 13.0 ± 16.5. There were no significant associations between the final QuickDASH score and any studied factor, including ADI, as determined using univariable analysis. Multivariable analysis showed no association between ADI and the final QuickDASH score, independent of age, sex, treating service, follow-up duration, and fracture alignment or pattern.ConclusionsAt mid-term follow up after distal radius ORIF, ADI did not correlate with QuickDASH scores, and the QuickDASH scores of the patients did not differ from those of the general population. However, our cohort mostly comprised patients with levels of deprivation below the national median. Although studies have shown that the short-term outcomes of distal radius ORIF are influenced by biopsychosocial factors, outcomes at the time of final recovery may not be associated with social deprivation.Type of study/level of evidencePrognostic IV.

The Impact of Global Spinal Alignment on Standing Spinopelvic Alignment Change After Total Hip Arthroplasty.

Retrospective cohort study. The interactions between hip osteoarthritis (OA) and spinal malalignment are poorly understood. The purpose of this study was to assess the influence of total hip arthroplasty (THA) on standing spinopelvic alignment. In this retrospective cohort study, patients undergoing THA for OA with pre-and postoperative full-body radiographs were included. Standing spinopelvic parameters were measured. Contralateral hip was graded on the Kellgren-Lawrence scale. Pre-and postoperative alignment parameters were compared by paired t-test. The severity of preoperative thoracolumbar deformity was measured using TPA. Linear regression was performed to assess the impact of preoperative TPA and changes in spinal alignment. Patients were separated into low and high TPA (<20 or >/=20 deg) and change in parameters were compared between groups by t-test. Similarly, the influence of K-L grade, age, and PI were also tested. 95 patients were included (mean age 58.6 yrs, BMI 28.7 kg/m2, 48.2% F). Follow-up radiographs were performed at mean 220 days. Overall, the following significant changes were found from pre-to postoperative: SPT (14.2 vs. 16.1, P = 0.021), CL (-8.9 vs. -5.3, P = .001), TS-CL (18.2 vs. 20.5, P = .037) and SVA (42.6 vs. 32.1, P = .004). Preoperative TPA was significantly associated with the change in PI-LL, SVA, and TPA. High TPA patients significantly decreased SVA more than low TPA patients. There was no significant impact of contralateral hip OA, PI, or age on change in alignment parameters. Spinopelvic alignment changes after THA, evident by a reduction in SVA. Preoperative spinal sagittal deformity impacts this change. Level of evidence: III.

Total knee arthroplasty according to the original knee phenotypes with kinematic alignment surgical technique\u2014early clinical and functional outcomes

BackgroundThe kinematic alignment (KA) technique in total knee arthroplasty (TKA) aims to restore the native alignment of pre-disease knee joint anatomy. Determining the individualized alignment targets is crucial for pre-operative planning, which can be set according to different original knee phenotypes. Five most common knee phenotypes have been categorized for KA-TKA alignment target setting in our previous study. The purpose of this study was to investigate the distribution of the five phenotypes in advanced OA knee patients and evaluate the clinical outcomes of this phenotype-oriented KA-TKA using the generic instrument, with particular emphasis on alignment strategy, surgical technique, survivorship, radiographic and functional outcomes.MethodsThe clinical data of 123 patients (88 women, 35 men) who had undergone 140 TKAs in our hospital were reviewed. All the TKAs were performed with alignment targets set according to the original phenotypes of the knee, with the KA method, using the generic total knee instrument. The patients’ demographics, preoperative and postoperative knee alignment angles, one-year postoperative range of motion (ROM), Oxford knee scores (OKS), Combined knee society score (CKSS) were collected and analyzed.ResultsThe 3 years survivorship was 99.3% for all cause of revision, and 100% with revision other than infection as the endpoint. The preoperative phenotypes of the knee were as follows: neutral alignment 20.1% (type 1: 3.6%, type 2: 16.5%), varus alignment 71.2% (type 3: 46.0%, type 4: 25.2%), and valgus alignment (type 5: 8.6%). Using our protocol, patients with different knee phenotypes could get similar great functional improvement though the postoperative alignment parameters were significantly different between the knee phenotypes (P < 0.05).ConclusionThe early outcomes of this phenotype-oriented KA-TKA using generic total knee instruments are promising. Setting individualized alignment target according to original knee phenotype is rational and practical. The residual varus alignment did not cause any aseptic loosening in the 3 years follow-up. Long-term survivorship and functional outcomes need to be evaluated in future studies.

Revision of a Medial UKA to a Kinematic Aligned TKA: Comparison of Operative Complexity, Postoperative Alignment, and Outcome Scores to a Primary TKA.

Revision of a medial unicompartmental knee arthroplasty (UKA) to a mechanically aligned total knee arthroplasty (MA TKA) is inferior to a primary TKA; however, revision with kinematic alignment (KA) has not been well studied. The present study determined whether patients revised with KA had a higher use of revision components, different postoperative alignment, and different clinical outcome scores from patients with a primary KA TKA. From 2006 to 2017, all patients suitable for a revision of a failed medial UKA to a TKA and a primary TKA were treated with KA. Reasons for the revision performed in ten females and six males at a mean age 67 ± 8 years included progression of osteoarthritis in the lateral hemi-joint (n = 6), aseptic loosening (n = 4), unremitting medial pain without loosening (n = 4), and insert wear (n = 2). Patients with a revision were matched 1:3 with a control cohort treated with a primary KA TKA. Revisions were performed with primary components without augments, stem extensions, or bone grafts. Seven postoperative alignment parameters of the limb and components were comparable to the control cohort (p > 0.05). At a mean follow-up of 5 years (1-10), implant survival was 100%, and the revision/primary group clinical outcome scores were 39/43 points for the Oxford Knee Score (OKS), 2.2/1.0 cm for the Visual Analog Pain Score, and 12/7 points for the Western Ontario and McMaster Universities Osteoarthritis Index score. When compared with primary KA TKA, surgeons that revise a failed medial UKA to a TKA with use of KA can expect similar operative complexity, comparable postoperative alignments, and a mean OKS of 39 points, which is higher than the mean 27 to 30 point range reported for revision of a failed UKA to a TKA with the use of MA.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

BACKGROUND CONTEXT Current preoperative planning for surgical adult spinal deformity (ASD) patients takes into account patient age when establishing postoperative alignment targets for sagittal vertical axis (SVA), pelvic tilt (PT) and spino-pelvic-mismatch (PI-LL). Patient height and pelvic incidence (PI), however, have yet to be evaluated for their individual effects on achieving age-adjusted alignment targets. PURPOSE This study assesses the individual effects of patient height and PI on age-adjusted alignment outcomes of surgical ASD patients. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE A total of 205 operative ASD patients. OUTCOME MEASURES Postoperative alignment parameters (PT, SVA, PI-LL, and SS); health-related quality of life (HRQL) scores. METHODS Surgical ASD patients >18 years with full-body stereographic x-ray imaging at baseline (BL) and early postoperative follow-up ( 75th) for both BL height and PI. Correction groups were generated at postoperative follow-up for actual alignment compared to age-adjusted ideal values for PT, PI-LL, and SVA, and PI-adjusted ideal alignment values for SS, as derived from clinically relevant formulas. Chi-squared tests assessed differences in rates of matching age-adjusted alignment ideal (±10years threshold for age-adjusted targets; −7° to 5° measured minus ideal for SS target) across height and PI groups. Subanalysis of patients matching age-adjusted alignment ideal used ANOVA to compare clinical outcomes across height and PI groups. RESULTS Included: 205 ASD patients (59±16 year, 64% F, 27±6 kg/m2). Following surgery, patients showed significant improvement in PT, PI-LL and SVA (all p .05). Height groups also did not differ in age or BMI (all p>.05), although female patients comprised a greater proportion of the low (96% F vs. 4% M) and normative (75% F vs. 25% M) height groups (p 0.05). Although there were no differences across PI groups in rates of achieving ideal alignment for PI-LL, SVA or SS (all p>.05), patients with high PI reached age-adjusted ideal alignment for PT at a significantly lower rate (15%) than patients with normative (36%) or low PI (33%, p=.031). Of the 58% of patients that matched any adjusted alignment target in early follow-up, there were no significant differences in postoperative HRQL outcomes across patient height or PI groups (all p>.05). CONCLUSIONS Patients with high pelvic incidence reached ideal postoperative age-adjusted PT alignment at a significantly lower rate than patients with normative and low pelvic incidence. In contrast, patient height had no impact on postoperative age-adjusted alignment outcomes. These results suggest that current postoperative ideal alignment targets may warrant adjustment to account for the morphological factor of pelvic incidence.

Adult Spinal Deformity Surgeons Are Unable to Accurately Predict Postoperative Spinal Alignment Using Clinical Judgment Alone

ObjectAdult spinal deformity (ASD) surgery seeks to reduce disability and improve quality of life through restoration of spinal alignment. In particular, correction of sagittal malalignment is correlated with patient outcome. Inadequate correction of sagittal deformity is not infrequent. The present study assessed surgeons' ability to accurately predict postoperative alignment. MethodsSeventeen cases were presented with preoperative radiographic measurements, and a summary of the operation as performed by the treating physician. Surgeon training, practice characteristics, and use of surgical planning software was assessed. Participants predicted if the surgical plan would lead to adequate deformity correction and attempted to predict postoperative radiographic parameters including sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence to lumbar lordosis mismatch (PI-LL), thoracic kyphosis (TK). ResultsSeventeen surgeons participated: 71% within 0 to 10 years of practice; 88% devote >25% of their practice to deformity surgery. Surgeons accurately judged adequacy of the surgical plan to achieve correction to specific thresholds of SVA 69% ± 8%, PT 68% ± 9%, and PI-LL 68% ± 11% of the time. However, surgeons correctly predicted the actual postoperative radiographic parameters only 42% ± 6% of the time. They were more successful at predicting PT (61% ± 10%) than SVA (45% ± 8%), PI-LL (26% ± 11%), or TK change (35% ± 21%; p < .05). Improved performance correlated with greater focus on deformity but not number of years in practice or number of three-column osteotomies performed per year. ConclusionSurgeons failed to correctly predict the adequacy of the proposed surgical plan in approximately one third of presented cases. They were better at determining whether a surgical plan would achieve adequate correction than predicting specific postoperative alignment parameters. Pelvic tilt and SVA were predicted with the greatest accuracy.