Biomechanical study of 3D-printed titanium alloy pad for repairing glenoid bone defect.

Background: The purpose of this study was to investigate the effect of 3D-printed technology to repair glenoid bone defect on shoulder joint stability. Methods: The shoulder joints of 25 male cadavers were tested. The 3D-printed glenoid pad was designed and fabricated. The specimens were divided into 5 groups. Group A: no bone defect and the structure of the glenoid labrum and joint capsule was intact; Group B: Anterior inferior bone defect of the shoulder glenoid; Group C: a pad with a width of 2 mm was installed; Group D: a pad with a width of 4 mm was installed; Group E: a pad with a width of 6 mm was installed. This study measured the distance the humeral head moved forward at the time of glenohumeral dislocation and the maximum load required to dislocate the shoulder. Results: The shoulder joint stability and humerus displacement was significantly lower in groups B and C compared with group A (p < .05). Compared with group A, the stability of the shoulder joint of group D was significantly improved (p < .05). However, there was no significant difference in humerus displacement between groups D and A (p > .05). In addition, compared with group A, shoulder joint stability was significantly increased and humerus displacement was significantly decreased in group E (p < .05). Conclusion: The 3D-printed technology can be used to make the shoulder glenoid pad to perfectly restore the geometric shape of the shoulder glenoid articular surface. Moreover, the 3D-printed pad is 2 mm larger than the normal glenoid width to restore the initial stability of the shoulder joint.

Double-pulley, V-shaped fixation technique for arthroscopic repair of ideberg type IA glenoid fracture.

Different techniques have been described for glenoid fractures, there is still a need for safe and effective agents to promote outcomes. From January 2016 to April 2021, the clinical data of 17 patients with pulley type IA fractures treated by the V-shaped fixation technique under shoulder arthroscopy were retrospectively analyzed. Preoperative X-ray, CT, and MRI examinations were completed. The functional score of the shoulder joint, such as the visual analog scale (VAS), Constant score, and Modified Rowe score, was used to evaluate the preoperative and final follow-up clinical outcomes. The active shoulder range of motion (ROM) was also collected preoperatively and at the final postoperative follow-up. Accordingly, intraoperative and postoperative complications were also observed. The mean follow-up was 49.52 months (16-79 months). The patients' follow-up exams showed that shoulder joint flexion, abduction, external rotation, internal rotation, and pain were not significantly different from those of the contralateral side (p > .05). The mean Constant score was 83.52 (58-98), and the average Modified Rowe score was 94.29 (70-100). X-ray and CT films of all cases showed good healing without articular depression or steps. Three patients had traumatic arthritis, with VAS <3 pain. No postoperative complications, such as infections, nerve or vessel damage, or suture anchor problems occurred during the follow-up period. Using the Double-pull, V-shaped fixation technique can stabilize the reduction of glenoid fractures while reducing the possibility of bone destruction. It is a good solution and provides an opportunity to treat rotator cuff tears associated with the procedure.

Morpho-functional analysis of the temporomandibular joint following mandible-first bimaxillary surgery with mandible-only patient-specific implants.

The aim of this study was to evaluate condylar and glenoid fossa remodeling after bimaxillary orthognathic surgery guided by patient-specific mandibular implants. In total, 18 patients suffering from dentofacial dysmorphism underwent a virtually planned bimaxillary mandibular PSI-guided orthognathic procedure. One month prior to surgery, patients underwent a CBCT scan and optical scans of the dental arches; these datasets were re-acquired 1 month and at least 9 months postsurgery. Three-dimensional models of the condyles, glenoid fossae, and interarticular surface space (IASS) were obtained and compared to evaluate the roto-translational positional discrepancy and surface variation of each condyle and glenoid fossa, and the IASS variation. The condylar position varied by an average of 4.31° and 2.18 mm, mainly due to surgically unavoidable ramus position correction. Condylar resorption remodeling was minimal (average ≤ 0.1 mm), and affected skeletal class III patients the most. Later condylar remodeling was positively correlated with patient age. No significant glenoid fossa remodeling was observed. No postoperative orofacial pain was recorded at clinical follow-up. The procedure was accurate in minimizing the shift in relationship between the bony components of the TMJ and their remodeling, and was effective in avoiding postoperative onset of orofacial pain. An increase in sample size, however, would be useful to confirm our findings.

Posterior deltoid-sparing approach for displaced inferior or posterior glenoid fossa fractures: technical note and case series.

Scapular surgery has usually been performed through the posterior Judet approach. This approach allows access to the entire posterior scapular body, but causes significant soft tissue damage and detaches the deltoid muscle. To date, there has been no clinical study of a deltoid-preserving approach to access the joint for displaced postero-inferior glenoid fractures (Ideberg type II or Ib). We describe an easy and less invasive approach to the postero-inferior glenoid fossa.

Both angled bony-increased offset and metal-augmented baseplates provide satisfactory bone incorporation to the glenoid in reverse total shoulder arthroplasty: a radiographic evaluation using tomosynthesis.

BACKGROUND: Angled bony-increased offset and metal-augmented baseplate have recently been used to achieve neutral to inferior inclination of the glenoid implant. Nonetheless, bone incorporation is difficult to evaluate using computed tomography or other conventional methods owing to the presence of metal artifacts; therefore, whether bone incorporation between the grafted bone and glenoid or between the graft and baseplate implant can be achieved remains unclear. Several studies have reported the effectiveness of tomosynthesis in reducing metal artifacts for the evaluation of implant loosening, bone resorption, and spot welds. We aimed to evaluate and compare the bone incorporation rates between angled bony-increased offset and metal-augmented implants using tomosynthesis with metal artifact reduction technology. We hypothesized that a high bone incorporation rate would be obtained with angled bony-increased offset and a metal-augmented baseplate. METHODS: A total of 52 patients who underwent reverse total shoulder arthroplasty (TSA) with angled bony-increased offset and 42 patients who underwent reverse total shoulder arthroplasty with metal-augmented baseplate were assessed and followed up for a minimum of 2 years. The bone incorporation and implant loosening rates were compared between the 2 groups, and the sites of spot welds and trabeculation were recorded according to zones. Bone incorporation between the bone and prosthesis was defined as a confirmation of spot welds connecting the porous area and bone in more than three zones. Bone incorporation between the native bone and grafted bone was defined as an observation of trabeculation. Glenoid loosening was defined as the presence of at least 1 mm radiolucency around the prosthesis in more than 2 zones. RESULTS: Both the angled bony-increased offset and metal-augmented baseplate groups achieved sufficient bone incorporation rates (98% [51/52 cases] vs. 100% [42/42 cases], P = 1.0) and low implant loosening rates (2% [1/52 cases] vs. 0% [0/42 cases], P = 1.0). Spot welds and trabeculation were likely to be confirmed in the lower parts of the glenoid. CONCLUSION: The two groups did not show any significant differences regarding bone incorporation rates. Considering the complexity of performing the procedure with angled bony-increased offset, the use of a metal-augmented baseplate can serve as an alternative treatment to avoid superior inclination in reverse total shoulder arthroplasty.

Femoral head allograft for glenoid bone loss in primary reverse shoulder arthroplasty: functional and radiologic outcomes.

BACKGROUND: Several techniques have been adopted during primary reverse shoulder arthroplasty (RSA) to manage glenoid bone defect. Among bone grafts, humeral head autograft is currently the mainstream option. However, autologous humeral heads may be unavailable or inadequate, and allografts may be a viable alternative. The aim of the present study was to evaluate the functional and radiologic outcomes of femoral head allografts for glenoid bone defects in primary RSA. METHODS: We conducted a retrospective study with prospective data collection enrolling 20 consecutive patients who underwent RSA with femoral head allografts for glenoid bone defects. Indications for surgery were eccentric cuff tear arthropathy in 10 cases (50%), concentric osteoarthritis in 9 cases (45%), and fracture sequelae in 1 case (5%). Each patient was evaluated preoperatively and at follow-up by radiologic and computed tomography (CT) and by assessing the range of motion (ROM) and the Constant-Murley score (CMS). A CT-based software, a patient-specific 3D model of the scapula, and patient-specific instrumentation were used to shape the graft and to assess the position of K-wire for the central peg. Postoperatively, CT scans were used to identify graft incorporation and resorption. RESULTS: After a median follow-up of 26.5 months (24-38), ROM and CMS showed a statistically significant improvement (all P = .001). The median measures of the graft were as follows: 28 mm (28-29) for diameter, 22° (10°-31°) for angle, 4 mm (2-8 mm) for minimum thickness, and 15 mm (11-21 mm) for maximum thickness. Before the surgery, the median glenoid version was 21.8° (16.5°-33.5°) for the retroverted glenoids and -13.5° (-23° to -12°) for the anteverted glenoids. At the follow-up, the median postoperative baseplate retroversion was 5.7° (2.2°-1.5°) (P = .001), and this value was close to the 4° retroversion planned on the preoperative CT-based software. Postoperative major complications were noted in 4 patients: 2 dislocations, 1 baseplate failure following a high-energy trauma, and 1 septic baseplate failure. Partial graft resorption without glenoid component failure was observed in 3 cases that did not require revision surgery. CONCLUSION: The femoral head allograft for glenoid bone loss in primary RSA restores shoulder function, with CMS values comparable to those of sex- and age-matched healthy individuals. A high rate of incorporation of the graft and satisfactory correction of the glenoid version can be expected after surgery. The management of glenoid bone defects remains a challenging procedure, and a 15% risk of major complication must be considered.

Yoke procedure as a salvage treatment option for failed reverse total shoulder arthroplasty with irreconstructible glenoid.

BACKGROUND: Glenoid bone loss is a known challenge in primary and revision reverse total shoulder arthroplasty. In severe deficiency, even placing the baseplate in alternative centerline or using an augmented baseplate may be insufficient. This study reports on the use of a soft tissue resurfacing technique using Achilles tendon allograft, coined Yoke procedure, for salvage treatment of glenoid deficient shoulder requiring reconstruction. MATERIALS AND METHODS: All patients who underwent the Yoke procedure between 2014 and 2020 by a single surgeon at a single academic center were identified and had their charts retrospectively reviewed. Demographics and surgical information were recorded. Preoperative X-rays and 3D-computed tomography scans were reviewed to classify patient glenoid types, evaluate glenoid medialization, and measure shoulder angles. Preoperative and postoperative range of motions and patient-reported outcome scores were evaluated, including anterior elevation, external rotation, internal rotation, visual analog scale, subjective shoulder value score, Simple Shoulder Test, and American Shoulder and Elbow Surgeons (ASES) scores. Postoperative radiographs and follow-up notes were reviewed to evaluate postoperative complication profiles at 1 year. RESULTS: Seven patients with a median age of 69 years (range, 54-77 years) underwent Yoke procedure and had a median 12-month follow-up (range, 9-56 months). All patients were female and had a median of 2 prior shoulder surgeries (range, 0-13). Of all the patients, the most common comorbidity was osteoporosis (6) followed by rheumatoid arthritis (3). Of the 5 patients who had previous arthroplasty, the most common indications were baseplate failure (4), followed by instability (3) and infection (3). The median visual analog scale score improved from 8 (range, 3-9) to 2 (range, 1-4). The median Simple Shoulder Test improved from 8% (range, 0%-42%) to 33% (range, 17%-83%). The median ASES score improved from 15 (range, 5-38) to 52 (range, 40-78). The median anterior elevation and external rotation improved from 20° (range, 0°-75°) to 100° (range, 40°-145°) and 10° (range, 0°-20°) to 20° (range, 0°-55°), respectively. There was no change in median internal rotation. As of the last follow-up, one patient reported postoperative complications of anterior-superior implant escape, heterotopic ossification, and scapular notching. CONCLUSION: The Yoke procedure is a promising salvage treatment that can offer patients consistent pain reduction and moderate functional improvements at short-term follow-up. In the setting of poor bone quality and severe glenoid deficiency, glenoid baseplate implantation may not be absolutely necessary for a pain-relieving, functionally acceptable outcome.

3-dimensionally printed patient-specific glenoid drill guides vs. standard nonspecific instrumentation: a randomized controlled trial comparing the accuracy of glenoid component placement in anatomic total shoulder arthroplasty.

BACKGROUND: Traditional, commercially sourced patient-specific instrumentation (PSI) systems for shoulder arthroplasty improve glenoid component placement but can involve considerable cost and outsourcing delays. The purpose of this randomized controlled trial was to compare the accuracy of glenoid component positioning in anatomic total shoulder arthroplasty (aTSA) using an in-house, point-of-care, 3-dimensionally (3D) printed patient-specific glenoid drill guide vs. standard nonspecific instrumentation. METHODS: This single-center randomized controlled trial included 36 adult patients undergoing primary aTSA. Patients were blinded and randomized 1:1 to either the PSI or the standard aTSA guide groups. The primary endpoint was the accuracy of glenoid component placement (version and inclination), which was determined using a metal-suppression computed tomography scan taken between 6 weeks and 1 year postoperatively. Deviation from the preoperative 3D templating plan was calculated for each patient. Blinded postoperative computed tomography measurements were performed by a fellowship-trained shoulder surgeon and a musculoskeletal radiologist. RESULTS: Nineteen patients were randomized to the patient-specific glenoid drill guide group, and 17 patients were allocated to the standard instrumentation control group. There were no significant differences between the 2 groups for native version (P = .527) or inclination (P = .415). The version correction was similar between the 2 groups (P = .551), and the PSI group was significantly more accurate when correcting version than the control group (P = .042). The PSI group required a significantly greater inclination correction than the control group (P = .002); however, the 2 groups still had similar accuracy when correcting inclination (P = .851). For the PSI group, there was no correlation between the accuracy of component placement and native version, native inclination, or the Walch classification of glenoid wear (P > .05). For the control group, accuracy when correcting version was inversely correlated with native version (P = .033), but accuracy was not correlated with native inclination or the Walch classification of glenoid wear (P > .05). The intraclass correlation coefficient was 0.703 and 0.848 when measuring version and inclination accuracy, respectively. CONCLUSION: When compared with standard instrumentation, the use of in-house, 3D printed, patient-specific glenoid drill guides during aTSA led to more accurate glenoid component version correction and similarly accurate inclination correction. Additional research should examine the influence of proper component position and use of PSI on clinical outcomes.

Reliability assessment of new radiographic scales to evaluate radiolucency and bony in-between fin growth of partially cemented all-polyethylene glenoid components.

BACKGROUND: Current methods available for assessment of radiolucency and in-between fin (IBF) growth of a glenoid component have not undergone interobserver reliability testing for an all-polyethylene fluted central peg (FCP) glenoid. The purpose of this study was to evaluate anteroposterior radiographs of an FCP glenoid component at ≥48 months comparing commonly used scales to a new method adapted to the FCP. Our hypothesis was that the new method would result in acceptable intra- and interobserver agreement and a more accurate description of radiographic findings. METHODS: We reviewed ≥48-month follow-up radiographs of patients treated with a primary aTSA using an FCP glenoid. Eighty-three patients were included in the review. Radiographs were evaluated by 5 reviewers using novel IBF radiodensity and radiolucency assessments and the Wirth and Lazarus methods. To assess intraobserver reliability, a subset of 40 images was reviewed. Kappa statistics were calculated to determine intra- and interobserver reliability; correlations were assessed using Pearson correlation. RESULTS: Interobserver agreement (κ score) was as follows: IBF 0.71, radiolucency 0.68, Wirth 0.48, and Lazarus 0.22. Intraobserver agreement ranges were as follows: IBF radiodensity 0.36-0.67, radiolucency 0.55-0.62, Wirth 0.11-0.73, and Lazarus 0.04-0.46. Correlation analysis revealed the following: IBF to Wirth r = 0.93, radiolucency to Lazarus r = 0.92 (P value <.001 for all). CONCLUSION: This study introduces a radiographic assessment method developed specifically for an FCP glenoid component. Results show high interobserver and acceptable intraobserver reliability for the method presented in this study. The new scales provide a more accurate description of radiographic findings, helping to identify glenoid components that may be at risk for loosening.

Validation of mixed-reality surgical navigation for glenoid axis pin placement in shoulder arthroplasty using a cadaveric model.

BACKGROUND: Mixed reality may offer an alternative for computer-assisted navigation in shoulder arthroplasty. The purpose of this study was to determine the accuracy and precision of mixed-reality guidance for the placement of the glenoid axis pin in cadaver specimens. This step is essential for accurate glenoid placement in total shoulder arthroplasty. METHODS: Fourteen cadaveric shoulders underwent simulated shoulder replacement surgery by 7 experienced shoulder surgeons. The surgeons exposed the cadavers through a deltopectoral approach and then used mixed-reality surgical navigation to insert a guide pin in a preplanned position and trajectory in the glenoid. The mixed-reality system used the Microsoft Hololens 2 headset, navigation software, dedicated instruments with fiducial marker cubes, and a securing pin. Computed tomography scans obtained before and after the procedure were used to plan the surgeries and determine the difference between the planned and executed values for the entry point, version, and inclination. One specimen had to be discarded from the analysis because the guide pin was removed accidentally before obtaining the postprocedure computed tomography scan. RESULTS: Regarding the navigated entry point on the glenoid, the mean difference between planned and executed values was 1.7 ± 0.8 mm; this difference was 1.2 ± 0.6 mm in the superior-inferior direction and 0.9 ± 0.8 mm in the anterior-posterior direction. The maximum deviation from the entry point for all 13 specimens analyzed was 3.1 mm. Regarding version, the mean difference between planned and executed version values was 1.6° ± 1.2°, with a maximum deviation in version for all 13 specimens of 4.1°. Regarding inclination, the mean angular difference was 1.7° ± 1.5°, with a maximum deviation in inclination of 5°. CONCLUSIONS: The mixed-reality navigation system used in this study allowed surgeons to insert the glenoid guide pin on average within 2 mm from the planned entry point and within 2° of version and inclination. The navigated values did not exceed 3 mm or 5°, respectively, for any of the specimens analyzed. This approach may help surgeons more accurately place the definitive glenoid component.

Covariations between scapular shape and bone density in B-glenoids: A statistical shape and density modeling-approach.

B-type glenoids are characterized by posterior humeral head migration and/or bony-erosion-induced glenoid retroversion. Patients with this type of osteoarthritic glenoids are known to be at increased risk of glenoid component loosening after anatomic total shoulder arthroplasty (aTSA). One of the main challenges in B glenoid surgical planning is to find a balance between correcting the bony shape and maintaining the quality of the bone support. This study aims to systematically quantify variabilities in terms of scapular morphology and bone mineral density in patients with B glenoids and to identify patterns of covariation between these two features. Using computed tomography scan images of 62 patients, three-dimensional scapular surface models were constructed. Rigid and nonrigid surface registration of the scapular surfaces, followed by volumetric registration and material mapping, enabled us to develop statistical shape model (SSM) and statistical density model (SDM). Partial least square correlation (PLSC) was used to identify patterns of covariation. The developed SSM and SDM represented 85.9% and 56.6% of variabilities in terms of scapular morphology and bone density, respectively. PLSC identified four modes of covariation, explaining 66.0% of the correlation between these two variations. Covariation of posterior-inferior glenoid erosion with posterior sclerotic bone formation in association with reduction of bone density in the anterior and central part of the glenoid was detected as the primary mode of covariation. Identification of these asymmetrical distribution of bone density can inform us about possible reasons behind glenoid component loosening in B glenoids and surgical guidelines in terms of the compromise between bony shape correction and bone support quality.

Mini-augmented glenoid baseplate and mini-humeral tray reverse total shoulder arthroplasty implant comparisons: two-year clinical outcomes.

BACKGROUND: Augmented glenoid baseplate and offset humeral tray reverse total shoulder arthroplasty (RTSA) implants may decrease the mechanical impingement that creates scapular notching and improve shoulder function. This study evaluated the clinical efficacy of three different RTSA glenoid baseplate and offset humeral tray combinations for patient-reported shoulder function, pain and instability, radiographic imaging evidence of glenoid baseplate or humeral stem subsidence and migration, bony changes associated with implant loosening, and scapular notching over the initial 2 years post-RTSA. Primary outcomes included active shoulder mobility, perceived function, pain, instability, scapular notching, and implant survival. METHODS: Sixty-seven patients from 6 research sites received one of three different glenoid baseplate and humeral tray combinations. Group 1 (n = 21) received a mini-augmented glenoid baseplate with a standard humeral tray; Group 2 (n = 23) received a standard glenoid baseplate and a mini-humeral tray with 3 trunnion offset options; Group 3 (n = 23) received both a mini-augmented glenoid baseplate and a mini-humeral tray with 3 trunnion offset options. Subjects underwent radiologic evaluation, completed the ASES scale, the EQ-5D-5L quality of life scale, VAS shoulder pain and instability questions, and active shoulder mobility measurements pre-operatively, and 6-weeks, 6-months, 1-2 years post-RTSA. RESULTS: Improved active shoulder mobility, quality of life, perceived function, decreased shoulder pain and instability, excellent implant survival and minimal scapular notching were observed for all groups. Group 3 had better overall active shoulder mobility than the other groups and better perceived function than Group 1. CONCLUSION: The group that received the mini-augmented glenoid baseplate and mini-humeral tray combination had better overall active shoulder flexion, external rotation at 90° abduction, and internal rotation. This group also had better perceived shoulder function compared to the group that received a mini-augmented glenoid baseplate with a standard humeral tray.

Pyrocarbon hemiprostheses show little glenoid erosion and good clinical function at 5.5 years of follow-up.

BACKGROUND: The success of traditional shoulder hemiarthroplasty (HA) with cobalt-chromium heads is limited by painful glenoid erosion with problematic bone loss. Hemiprostheses with pyrolytic carbon (PyC) heads have shown reduced glenoid erosion in experimental laboratory studies. Few in vivo data are available. METHODS: We performed a single-center consecutive cohort study of 31 of 34 patients (91%) who underwent PyC HA between September 2013 and June 2018. In 11 of these patients, concentric glenoid reaming was additionally performed. The mean follow-up period was 5.5 years (range, 3.5-7 years). Standardized radiographs were taken, and clinical function (Constant score) and pain (visual analog scale score) were recorded. Anteroposterior radiographs were analyzed according to an established method by 2 independent observers: A line parallel to the superior and inferior glenoid rim was translated to the most medial point of the glenoid surface. A further parallel line was placed on the spinoglenoid notch. The distance between these 2 lines was measured. Measurements were scaled using the known diameter of the implanted humeral head component. To assess eccentric erosion, anteroposterior and axial images were classified according to Favard and Walch, respectively. RESULTS: Mean medial glenoid erosion measured 1.4 mm at an average of 5.5 years of follow-up. In the first year, 0.8 mm of erosion was observed, significantly more than the average erosion per year of 0.3 mm (P < .001). Mean erosion per year was 0.4 mm in patients with glenoid reaming vs. 0.2 mm in those without reaming (P = .09). An evolution of glenoid morphology was observed in 6 patients, of whom 4 had a progression of the erosion grade. The prosthesis survival rate was 100%. The Constant score improved from 45.0 preoperatively to 78.0 at 2-3 years postoperatively and 78.8 at latest follow-up (5.5 years postoperatively) (P < .001). The pain score on a visual analog scale decreased from 6.7 (range, 3-9) preoperatively to 2.2 (range, 0-8) at latest follow-up (P < .001). There was a weak correlation (r = 0.37) between erosion and pain improvement (P = .039) and no correlation between erosion and change in Constant score (r = 0.06). CONCLUSION: PyC HA caused little glenoid erosion and a sustained improvement in clinical function in our cohort at mid-term follow-up. PyC demonstrates a biphasic development of glenoid erosion, with a reduced rate after the first year. PyC HA should therefore be considered as an alternative to cobalt-chromium HA and to anatomical total shoulder arthroplasty for patients with a high risk of glenoid component complications.

Treatment of Glenoid Wear with the Use of Augmented Glenoid Components in Total Shoulder Arthroplasty: A Scoping Review.

¼ Treatment of glenoid bone loss continues to be a challenge in total shoulder arthroplasty (TSA). Although correcting glenoid wear to patient's native anatomy is desirable in TSA, there is lack of consensus regarding how much glenoid wear correction is acceptable and necessary in both anatomic and reverse TSA.¼ Use of augmented glenoid components is a relatively new treatment strategy for addressing moderate-to-severe glenoid wear in TSA. Augmented glenoid components allow for predictable and easy correction of glenoid wear in the coronal and/or axial planes while at the same time maximizing implant seating, improving rotator cuff biomechanics, and preserving glenoid bone stock because of off-axis glenoid reaming.¼ Augmented glenoid components have distinct advantages over glenoid bone grafting. Glenoid bone grafting is technically demanding, adds to the surgical time, and carries a risk of nonunion and graft resorption with subsequent failure of the glenoid component.¼ The use of augmented glenoid components in TSA is steadily increasing with easy availability of computed tomography-based preoperative planning software and guidance technology (patient-specific instrumentation and computer navigation).¼ Although different augment designs (full wedge, half wedge, and step cut) are available and a particular design may provide advantages in specific glenoid wear patterns to minimize bone removal (i.e. a half wedge in B2 glenoids), there is no evidence to demonstrate the superiority of 1 design over others.

Bilateral Posterior Bone Graft Augmentation for Severe Glenoid Hypoplasia Without Instability: A Case Report.

CASE: A 40-year-old man with shoulder pain secondary to severe bilateral glenoid hypoplasia without posterior instability was treated successfully with bilateral posterior glenoid bone graft augmentation. CONCLUSION: While glenoid hypoplasia is associated with a variety of patient presentations, treatment of the stable and nonarthritic shoulder is rarely described. A posterior glenoid bone graft can be used to augment deficient posterior glenoids, increasing the articulating surface area, restoring function, and potentially facilitating future shoulder arthroplasty.

A prospective radiostereometric analysis of the stability of a metal-backed glenoid component/autograft composite in reverse shoulder arthroplasty.

Aims: Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA). Methods: A total of 14 patients who underwent a rTSA with an autograft consented to participate. Of these, 11 had a primary rTSA using humeral head autograft and three had a revision rTSA with autograft harvested from the iliac crest. The mean age of the patients was 66 years (39 to 81). Tantalum beads were implanted in the scapula around the glenoid. RSA imaging (stereographic radiographs) was undertaken immediately postoperatively and at three, six, 12, and 24 months. Analysis was completed using model-based RSA software. Outcomes were collected preoperatively and at two years postoperatively, including the Oxford Shoulder Score, the American Shoulder and Elbow Score, and a visual analogue score for pain. A Constant score was also obtained for the assessment of strength and range of motion. Results: RSA analysis showed a small increase in all translation and rotational values up to six months postoperatively, consistent with settling of the implant. The mean values plateaued by 12 months, with no evidence of further migration. In four patients, there was significant variation outside the mean, which corresponded to postoperative complications. There was a significant improvement in the clinical and patient-reported outcomes from the preoperative values to those at two years postoperatively (p < 0.001). Conclusion: These findings show, using RSA, that a glenoid baseplate composite of a trabecular titanium peg with autograft stabilizes within the glenoid about 12 months after surgery, and reinforce findings from a previous study of this implant/graft with CT scans at two years postoperatively, indicating that this type of structural composite results in sound early fixation.

Glenoid component placement in reverse shoulder arthroplasty assisted with augmented reality through a head-mounted display leads to low deviation between planned and postoperative parameters.

BACKGROUND: Navigated augmented reality (AR) through a head-mounted display (HMD) may lead to accurate glenoid component placement in reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the deviation between planned, intra- and postoperative inclination, retroversion, entry point, depth, and rotation of the glenoid component placement assisted by a navigated AR through HMD during RSA. METHODS: Both shoulders of 6 fresh frozen human cadavers, free from fractures or other bony pathologies, were used. Preoperative computed tomography (CT) scans were used for the 3-dimensional (3D) planning. The glenoid component placement was assisted using a navigated AR system through an HMD in all specimens. Intraoperative inclination, retroversion, depth, and rotation were measured by the system. A postoperative CT scan was performed. The pre- and postoperative 3D CT scan reconstructions were superimposed to calculate the deviation between planned and postoperative inclination, retroversion, entry point, depth, and rotation of the glenoid component placement. Additionally, a comparison between intra- and postoperative values was calculated. Outliers were defined as >10° inclination, >10° retroversion, >3 mm entry point. RESULTS: The registration algorithm of the scapulae prior to the procedure was correctly completed for all cases. The deviations between planned and postoperative values were 1.0° ± 0.7° for inclination, 1.8° ± 1.3° for retroversion, 1.1 ± 0.4 mm for entry point, 0.7 ± 0.6 mm for depth, and 1.7° ± 1.6° for rotation. The deviation between intra- and postoperative values were 0.9° ± 0.8° for inclination, 1.2° ± 1.1° for retroversion, 0.6 ± 0.5 mm for depth, and 0.3° ± 0.2° for rotation. There were no outliers between planned and postoperative parameters. CONCLUSION: In this study, the use of a navigated AR system through an HMD for RSA led to low deviation between planned and postoperative values and between intra- and postoperative parameters.

Comparison of long-term clinical and radiological outcomes for cemented keel, cemented peg, and hybrid cage glenoids with anatomical total shoulder arthroplasty using the same humeral component.

Aims: The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system. Methods: We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217). Results: Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%). Conclusion: These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids.

Clinical and radiologic outcomes of Lima ProMade custom 3D-printed glenoid components in primary and revision reverse total shoulder arthroplasty with severe glenoid bone loss: a minimum 2-year follow-up.

BACKGROUND: The purpose of this study is to report the clinical and radiologic outcomes of patients undergoing primary or revision reverse total shoulder arthroplasty using custom 3D-printed components to manage severe glenoid bone loss with a minimum of 2-year follow-up. METHODS: Following ethical approval, patients were identified and invited to participate. Inclusion criteria were (1) severe glenoid bone loss necessitating the need for custom implants and (2) patients with definitive glenoid and humeral components implanted more than 2 years prior. Included patients underwent clinical assessment using the Oxford Shoulder Score (OSS), Constant-Murley score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and the quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH). Radiographic assessment included anteroposterior and axial projections. Patients were invited to attend a computed tomography (CT) scan to confirm osseointegration. Statistical analysis used descriptive statistics (mean and standard deviation [SD]) and paired t test for parametric data. RESULTS: Eleven patients declined to participate. Five patients were deceased prior to study commencement, leaving 42 remaining patients in this analysis. Three patients had revision surgery before the 2-year follow-up; of these, 2 retained their custom glenoid components. Mean follow-up was 31.6 months from surgery (range 24-52 months). All 4 scores improved: OSS from a mean 15 (SD 8.4) to 36 (SD 12) (P < .001), Constant-Murley score from a mean 15 (SD 11.2) to 52 (SD 20.1) (P < .001), QuickDASH from a mean 70 (SD 21) to 31 (SD 24.8) (P = .004), and the ASES score from a mean 22 (SD 17.8) to 71 (SD 23.3) (P = .007). Radiologic evaluation demonstrated good osseointegration in all but 1 included patient. CONCLUSION: The utility of custom 3D-printed components for managing severe glenoid bone loss in primary and revision reverse total shoulder arthroplasty yields significant clinical improvements in this complex cohort. Large complex glenoid bone defects can be managed successfully with custom 3D-printed glenoid components.