Nitin Goyal

Clinical, functional, and radiographic outcomes following total knee arthroplasty with patient-specific instrumentation, computer-assisted surgery, and manual instrumentation: a short-term follow-up study

Purposexa0xa0xa0The purpose of this study was to evaluate clinical, functional, and radiographic outcomes following total knee arthroplasty (TKA) performed with patient-specific instrumentation (PSI), computer-assisted surgery (CAS), and manual instruments at short-term follow-up.Methodsxa0xa0xa0122 TKAs were performed by a single surgeon: 42 with PSI, 38 with CAS, and 40 with manual instrumentation. Preoperative, 1-month, and 6-month clinical and functional outcomes were measured using the Knee Society scoring system (knee score, function score, range of motion, and pain score). Improvements in clinical and functional outcomes from the preoperative to postoperative period were analyzed. Preoperative and postoperative radiographs were measured to evaluate limb and component alignment.Resultsxa0xa0xa0Preoperative, 1-month postoperative, and 6-month postoperative knee scores, function scores, range of motion, and pain scores were highest in the PSI group compared to CAS and manual instrumentation. At 6-month follow-up, PSI TKA was associated with a statistically significant improvement in functional score when compared to manual TKA. Otherwise, there were no statistically significant differences in improvements among PSI, CAS, and manual TKA groups.Conclusionxa0xa0xa0The higher preoperative scores in the PSI group limits the ability to draw definitive conclusions from the raw postoperative scores, but analyzing the changes in scores revealed that PSI was associated with a statistically significant improvement in Knee Society Functional score at 6-month post-TKA as compared to CAS or manual TKA. This may be attributable to improvements in component rotation and positioning, improved component size accuracy, or other factors that are not discernible on plain radiograph.

Radiographic Study of the Fifth Metatarsal for Optimal Intramedullary Screw Fixation of Jones Fracture

Background: Jones fractures occur in the relatively avascular metadiaphyseal junction of the fifth metatarsal (MT), which predisposes these fractures to delayed union and nonunion. Operative treatment with intramedullary (IM) screw fixation is recommended in certain cases. Incorrect screw selection can lead to refractures, nonunion, and cortical blowout fractures. A better understanding of the anatomy of the fifth MT could aid in preoperative planning, guide screw size selection, and minimize complications. Methods: We retrospectively identified foot computed tomographic (CT) scans of 119 patients that met inclusion criteria. Using interactive 3-dimensional (3-D) models, the following measurements were calculated: MT length, “straight segment length” (distance from the base of the MT to the shaft curvature), and canal diameter. Results: The diaphysis had a lateroplantar curvature where the medullary canal began to taper. The average straight segment length was 52 mm, and corresponded to 68% of the overall length of the MT from its proximal end. The medullary canal cross-section was elliptical rather than circular, with widest width in the sagittal plane and narrowest in coronal plane. The average coronal canal diameter at the isthmus was 5.0 mm. A coronal diameter greater than 4.5 mm at the isthmus was present in 81% of males and 74% of females. Conclusion: To our knowledge, this is the first anatomic description of the fifth metatarsal based on 3-D imaging. Excessive screw length could be avoided by keeping screw length less than 68% of the length of the fifth metatarsal. A greater than 4.5 mm diameter screw might be needed to provide adequate fixation for most study patients since the isthmus of the medullary canal for most were greater than 4.5 mm. Clinical Relevance: Our results provide an improved understanding of the fifth metatarsal anatomy to guide screw diameter and length selection to maximize screw fixation and minimize complications.

Which Tibial Tray Design Achieves Maximum Coverage and Ideal Rotation: Anatomic, Symmetric, or Asymmetric? An MRI-based study

Two goals of tibial tray placement in TKA are to maximize coverage and establish proper rotation. Our purpose was to utilize MRI information obtained as part of PSI planning to determine the impact of tibial tray design on the relationship between coverage and rotation. MR images for 100 consecutive knees were uploaded into PSI software. Preoperative planning software was used to evaluate 3 different tray designs: anatomic, symmetric, and asymmetric. Approximately equally good coverage was achieved with all three trays. However, the anatomic compared to symmetric/asymmetric trays required less malrotation (0.3° vs 3.0/2.4°; P < 0.001), with a higher proportion of cases within 5° of neutral (97% vs 73/77%; P < 0.001). In this study, the anatomic tibia optimized the relationship between coverage and rotation.

Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in Total Knee Arthroplasty

PSI software adjusts preoperative planning to accommodate differences in implant design. Such adjustments may influence the accuracy of intraoperative jig placement, bone resection, or component placement. Our purpose was to determine whether implant design influences PSI accuracy. 96 and 123 PSI TKA were performed by a single surgeon using two different implant systems and identical PSI software. Femoral coronal alignment outliers were greater for Implant 1 (23.9% Implant 1 vs. 13.4% Implant 2; P=0.050). Tibial coronal alignment outliers were greater for Implant 2 (10.9% Implant 1 vs. 22.7% Implant 2; P=0.025). There was no difference in overall mechanical axes. Differences in implant design can influence bone resection and component alignment. PSI software rationale must align with surgeons intraoperative goals.

The use of an iPad to collect patient-reported functional outcome measures in hand surgery

BackgroundThe purpose of this study was to evaluate (1) patient preferences regarding iPad and paper-based questionnaires, (2) the efficacy of iPad and paper questionnaires in a hand surgery practice, (3) the influence of questionnaire length on patient preferences and data collection, and (4) patient characteristics associated with a preference for iPad-based questionnaires.MethodsTwo hundred total patients in a single hand surgery practice were randomly assigned to one of four groups. Each group completed either the Michigan Hand Questionnaire (MHQ) or QuickDASH (QD) using either an iPad or pen and paper. Patient preferences, questionnaire completion and timing, and demographic data were analyzed.ResultsThe use of an iPad was associated with a statistically stronger preference for the same delivery format in the future compared to paper for the MHQ (93.9 vs 52.1xa0%, pu2009<u20090.001) and QD (90.0 vs 41.7xa0%, pu2009<u20090.001). The MHQ iPad group found the survey “physically easy” more often compared to the MHQ paper group, while no difference was found among QD groups. Questionnaire timing between iPad and paper groups was similar for the MHQ but statistically longer with the iPad for QD. A significantly higher proportion of patients who preferred the iPad were under the age of 50 compared to those who preferred paper.ConclusionsThe addition of an iPad is an efficient and preferable questionnaire format for functional outcome assessment in a hand and upper extremity surgery practice setting. The iPad is particularly preferable for longer outcome questionnaires and for patients under the age of 50.

Computer-assisted versus manual TKA: no difference in clinical or functional outcomes at 5-year follow-up.

The purpose of this study was to determine whether differences in clinical, functional, or radiographic outcomes existed at 5-year follow-up between patients who underwent computer-assisted or manual total knee arthroplasty (TKA). Seventy-eight consecutive TKAs were performed by a single surgeon who had extensive experience performing computer-assisted and manual TKA. The manual group (n=40) and computer-assisted group (n=38) were similar with regard to age, sex, diagnosis, body mass index, surgical technique, implants, perioperative management, Knee Society scores, and anteroposterior mechanical axis. Sixty-three (manual group, n=34; computer-assisted group, n=29) patients were available for final follow-up. At 5-year follow-up, no statistically significant differences were found in Knee Society knee score (P=.289), function score (P=.272), range of motion (P=.284), pain score (P=.432), or UCLA activity score (P=.109) between the 2 groups. Postoperative radiographs showed a significant difference in the mechanical axis (P=.004) between the 2 groups; however, both groups achieved a neutral mechanical axis of ±3° (computer-assisted group mean, 2.0°; manual group mean, -0.24°).When TKA was performed by an experienced surgeon, no significant difference was identified at 5-year follow-up between patients who underwent computer-assisted vs manual TKA.

Evaluating the Precision of Preoperative Planning in Patient Specific Instrumentation: Can a Single MRI Yield Different Preoperative Plans?

If PSI preoperative planning were perfectly precise, a single MRI would give rise to one preoperative plan. Our purpose was to determine whether a single MRI inputted into two different PSI software yielded differences in preoperative alignment determination, component sizing, and bone resection within the preoperative plan. This prospective comparative study evaluated 40 preoperative plans generated by two PSI software given identical MRI. Femoral and tibial component sizes differed between software in 37.5% and 30.0% of cases, respectively. The maximum difference in bone resection between software ranged from 2.2mm to 5.1mm. Surgeons should be prepared to intraoperatively deviate from PSI selected size by 1 size. It may be necessary to fine tune soft tissue balancing when using a PSI system.