Chapter 7 - Preoperative planning and imaging

Chapter 18 - Preoperative planning and imaging

Commentary Iannotti et al. present a very interesting and useful investigation into the use of three-dimensional preoperative imaging and templating to assist in planning the positioning of the glenoid component during anatomic shoulder arthroplasty. Additionally, any possible benefit of patient-specific instrumentation was evaluated. To my knowledge, this is the first investigation into the clinical efficacy of this particular emerging technology. All too often, new technological innovations are rapidly adopted without any proven efficacy. This study provides evidence of the role of three-dimensional imaging and templating in the surgical treatment of patients with primary osteoarthritis. This article provides a glimpse into the near future of anatomic shoulder arthroplasty. The Materials and Methods portion of this article was appropriate to achieve the goals of the study. The study consisted of a prospective, randomized controlled trial involving a comparison of patients undergoing three-dimensional imaging and templating with patients undergoing the same imaging and templating technique with the addition of patient-specific instrumentation to assist in glenoid component positioning; a third cohort of patients who had undergone conventional two-dimensional templating was used to serve as a historical control. The retrospective latter part of this study slightly weakens its experimental design. However, given that all of the surgical procedures were performed by experienced surgeons well into their learning curve, I doubt that prospectively collecting the data on the two-dimensional group would have appreciably impacted the results. It is unclear why the authors included twenty-five patients in one group, twenty-one patients in another group, and seventeen patients in the third group. Because no patient was lost to follow-up or withdrew from the study, a better explanation of the choice of the number of the subjects to be included in each group seems warranted. This investigation was limited to a computed tomographic evaluation of glenoid component positioning at a short-term follow-up (less than three weeks). No clinical data are provided, nor would they have been useful that early in the postoperative period. The Results portion of this article yields two very important points. First, three-dimensional imaging and templating are superior to conventional two-dimensional planning in achieving the desired placement of the glenoid component in anatomic shoulder arthroplasty for primary osteoarthritis. Second, the addition of patient-specific instrumentation did not appreciably improve the surgeon’s ability to place the glenoid component in the desired location. Unfortunately, because the follow-up was too short for any meaningful clinical data to be provided, the ultimate clinical implications of this improvement in glenoid component positioning with use of three-dimensional imaging and templating compared with two-dimensional imaging and templating remains unknown. Glenoid component loosening remains a pervasive factor in the failure of anatomic shoulder arthroplasty1. Although many factors undoubtedly contribute to glenoid component failure, proper positioning of the glenoid component would seem to be critical in avoiding this complication. Iannotti et al. have shown a reproducible and accurate method to place the glenoid component in the desired position with use of three-dimensional imaging and templating and have further demonstrated the superiority of this technique over conventional two-dimensional preoperative planning. The methods of glenoid positioning used in this study would seemingly prove useful in nearly all cases of anatomic total shoulder arthroplasty. The value of this method would likely prove more beneficial in difficult cases involving substantial glenoid wear. Another potential area of applicability for the three-dimensional preoperative planning shown in this study that was not discussed by the authors is the use of this technique to preserve existing glenoid bone. Walch et al. recently demonstrated the importance of preservation of subchondral bone in preventing glenoid component failure2. Using information gained from three-dimensional imaging and templating described by Iannotti et al., the radius of curvature of the native glenoid could be established to allow the use of instrumentation and implants that do not require removal of subchondral bone to permit component placement. Importantly, this investigation did not show the benefit in using patient-specific instrumentation. In the increasingly cost-conscious environment of health care, higher cost must yield substantial benefit. The main limitation of this study was the lack of clinical correlation with the radiographic results. Although the three-dimensional preoperative planning proved to be better than two-dimensional preoperative planning at achieving the desired glenoid component positioning, the clinical relevance of this is unclear. I would encourage the authors to continue to follow these patients and to correlate clinical outcomes, complications, and revision rates with glenoid component positioning. If a relationship is subsequently demonstrated, more value will be added to this technique. Congratulations to Dr. Iannotti and his associates for their work on this study. This article shows that the future is now in using novel technology to improve our radiographic results. Time will tell if these radiographic improvements will translate into better clinical results, lower complication rates, and improved prosthetic longevity for our patients.

Implant Removal in Revision Arthroplasty: A Tour de Force

Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique. Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection. We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy. The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively. Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.

Assessing glenoid arthroplasty component positioning for surgeons utilizing surgical planning software

The arthroscopic Latarjet procedure has provided reliable results in the treatment of anterior shoulder instability. However, this procedure remains technically challenging and is related to several complications. The morphology of the coracoid and the glenoid are inconsistent. Inadequate coracoid and glenoid preparing may lead to mismatching between their surfaces. Inadequate screws lengthening and orientation are a major concern. Too long screws can lead to suprascapular nerve injuries or hardware irritation, whereas too short screws can lead to nonunions, fibrous unions or migration of the bone block. The purpose of the study was to investigate the application of virtual surgical planning and digital technology in preoperative assessment and planning of the Latarjet procedure. Twelve patients planned for an arthroscopic Latarjet had a CT scan evaluation with multi-two-dimensional reconstruction performed before surgery. Interobserver and intraobserver reliability were evaluated. The shape of the anterior rim of the glenoid and the undersurface of the coracoid were classified. Coracoid height was measured, respectively, at 5mm (C1) and 10mm (C2) from the tip of the coracoid process, corresponding to the drilling zone. Measurements of the glenoid width were then taken in the axial view at 25% (G1) and 50% (G2) of the glenoid height with various α angles (5°, 10°, 15°, 20°, 25°, 30°) 7mm from the anterior glenoid rim. Shapes of the undersurface of the coracoid and the anterior rim of the glenoid were noted during the surgical procedure. Post-operative measurements included the α angle. Concerning coracoid height measurements, there was an almost perfect to substantial intra- and inter-reliability, with values ranging from ICC=0.75-0.97. For the shape of the coracoid, concordances were, respectively, perfect (ICC=1) and almost perfect (0.87 [0.33; 1]) for the intra- and interobserver reliabilities. Concerning the glenoid, concordance was always almost perfect for 50% height. Concordance was almost perfect for 25% height 15° and 30° for inter- and intraobserver, for intraobserver at 0° and 25°. All the other values were still showing moderate concordance. Shape of the coracoid analysis reproducibility was perfect for both intra- and interobserver ICC=1. There was a total agreement (ICC=1) between the preoperative evaluation of the shape of the glenoid and the coracoid and the intraoperative assessment. The ideal and accurate preoperative planning of screwing of the coracoid graft in the arthroscopic Latarjet can be achieved in the real surgery assisted by the virtual planning. The clinical importance of this study lies in the observation that this new preoperative planning could offer a simple, effective and reproducible tool for surgeons helping them to prepare in the best possible way a technically challenging procedure usually associated with a high rate of complications.

Influence of glenoid wear pattern on glenoid component placement accuracy in shoulder arthroplasty.

Automated muscle elongation measurement during reverse shoulder arthroplasty planning

Chapter 32 - Results and complications

Preoperative Planning and Plan Execution in Shoulder Arthroplasty

Preoperative renal tumor evaluation by three-dimensional magnetic resonance imaging: Staging and detection of multifocality

Three-Dimensional Technology to Diagnose Unilateral Cervical Atresia in Obstructive Hemivagina with Ipsilateral Renal Anomaly: A Case Report and Review of the Literature

Nine patients with symptomatic glenoid loosening were identified and ultimately underwent surgical revision. Preoperative assessment demonstrated that pain, decreased range of motion, and functional disability were common features. A painful clunking sensation with forward elevation of the arm was noted in four of the nine patients. At surgical revision, a grossly loose glenoid component was found in all cases and removed. Seven of the nine patients underwent revision using another cemented glenoid component, and two patients were left with a hemiarthroplasty due to glenoid bone deficiency. Results following revision surgery demonstrated increased range of motion, decreased pain, and increased functional ability with good overall patient satisfaction in seven of nine patients. Two patients in whom revision glenoid components were implanted were considered failures due to recurrent loosening. Although revision of the glenoid component is often technically feasible, recurrent loosening may occur. Revision to a hemiarthroplasty may be an acceptable alternative to glenoid replacement.

Outcomes of Osteochondral Lesions of the Knee Repaired With a Bioabsorbable Device

Breast augmentation is the most common aesthetic surgical procedure performed in the United States (http://www.plasticsurgery.org/news/plastic-surgery-statistics/2014-statistics/top-five-cosmetic-surgery-procedures-2014.html). Because of this, adequate preoperative surgical planning, mastery of the intraoperative surgical technique, thorough postoperative care, and ability to recognize potential postoperative complications are vital. In order to address patient goals and expectations, a discussion with your patient regarding the type of implant (silicone vs. saline, smooth vs. textured, anatomic vs. round), location of incision (inframammary, periareolar, transaxillary, transumbilical), and location of implant pocket (subfascial, subglandular, submuscular, subpectoral with dual plane I, II, or III) should take place. Thorough preoperative planning and patient education are essential for an ideal aesthetic result and patient satisfaction (Adams, Plast Reconstr Surg 122:1892–1900, 2008).