Preoperative differences in glenoid deformity,patient-determined outcomes,and range of motion as per disease type in shoulders undergoing total shoulder arthroplasty

BackgroundDiseases commonly treated with shoulder arthroplasty include the following: osteoarthritis, rotator cuff tear arthropathy (RCTA), and irreparable rotator cuff tears (IRCTs). Currently, there are few data available that identify if preoperative differences exist between these disorders in (1) computed tomography findings, (2) patient-determined outcome scores, and (3) range of motion. Understanding these disease-specific differences may allow for the development of disease-specific strategies in total shoulder arthroplasty to attempt to improve patient outcomes and implant longevity.MethodsA database of shoulders undergoing anatomic and reverse total shoulder arthroplasty was reviewed. The cohort was divided into three groups as per the disease treated with total shoulder arthroplasty: osteoarthritis, RCTA, and IRCT. The outcomes included preoperative range of motion, 3-dimensional computed tomography determination of glenoid morphology, and patient-determined outcomes including the Western Ontario Osteoarthritis Scale, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and the Single Assessment Numeric Evaluation. Differences between the groups were examined with analysis of variance with post hoc Tukey’s HSD test. The level of significance was P = .05.ResultsTwo hundred seventy-nine shoulders met inclusion and exclusion criteria. One hundred fifty-four shoulders had osteoarthritis, 94 shoulders had RCTA, and 21 shoulders had an IRCT. Patients with osteoarthritis had significantly greater mean glenoid retroversion (12.9°) than patients with an IRCT (7°; P = .03) and RCTA (8.6°; P = .004). Patients with osteoarthritis had significantly less mean superior glenoid inclination (5.9°) than patients with an IRCT (10.2°; P = .03) and RCTA (9.5°; P = .001). Patients with osteoarthritis had greater mean posterior humeral subluxation (68.9%) than patients with an IRCT (58.3%; P = .002) and RCTA (60.2%; P = .001).There was no difference in preoperative Western Ontario Osteoarthritis Scale (P = .86), American Shoulder and Elbow Surgeons score (P = .81), Simple Shoulder Test (P = .13), and Single Assessment Numeric Evaluation (P = .57). Patients with osteoarthritis had greater mean flexion (101°) than the IRCT (86°; P = .17) and RCTA groups (84°; P = .001). Patients with osteoarthritis had greater mean external rotation in the abducted position (54°) than the RCTA group (38°; P = .001) but similar to the IRCT group (48°; P = .68). The osteoarthritis group had inferior mean internal rotation in the abducted position (0.2°) compared with the RCTA (20.6°; P = .001). There were no differences in extension (P = .08), external rotation (P = .58), and abduction (P = .15).ConclusionShoulders with osteoarthritis have greater glenoid retroversion and posterior humeral subluxation, whereas shoulders with RCTA or IRCT have greater superior glenoid inclination. Patient-determined outcome scores do not differ between these diseases. Shoulders with osteoarthritis have greater baseline (1) flexion and (2) abducted external rotation but inferior abducted internal rotation.     

Clinical and radiographic results of eccentric glenoid reaming in anatomical total shoulder arthroplasty using 3D planning and PSI

BackgroundTreatment of deformed type B glenoids with anatomical total shoulder arthroplasty (TSA) can be challenging when using standard imaging and instrumentation. 3D planning and PSI-guided (patient-specific instrumentation) eccentric reaming may substantially aid in both the glenoid correction and implantation of anatomical components in difficult cases. We hypothesized that the implementation of preoperative planning and a PSI-guided anatomical component protocol would result in accurate correction of the glenoid deformity and precise glenoid implant positioning.MethodsTwenty-two consecutive patients with primary glenohumeral osteoarthritis, intact rotator cuff and modified-Walch type B glenoids were treated with anatomical total shoulder arthroplasty. Preoperative 3D planning and PSI were used to guide eccentric reaming and correct glenoid deformity. Postoperative clinical and radiographic outcomes were assessed in all patients with a minimum follow-up of 2 years (mean of 26 months). Postoperative corrections of glenoid version and inclination were measured and the variation between preoperative planning and postoperative implant position was evaluated on CT 3D reconstructions. Similarly, both humeral subluxation in the axial scapular plane and glenoid joint line medialization were compared between preoperative and postoperative computed tomographic imaging.ResultsThe mean age was 57 years (range, 54-68). Significant improvements in pain and functional outcome measurements were seen in all 22 subjects. Mean native glenoid version and inclination were −15° ± 5° and 3° ± 5°, respectively. Postoperatively, version was corrected to −7° ± 6° and inclination to 1° ± 2°. Cortical central peg perforation was noted in 1 case and cement perforation in 3 cases. The mean deviation from the preoperative plan was 3° ± 3° for version and 2° ± 2° for inclination. Humeral head subluxation improved from 68% ± 6% to 37% ± 6% and re-centering on the glenoid implant was achieved in all cases. The mean executed medialization of the glenoid joint line was 6 ± 3 mm and proved accurate to within 1 ± 1 mm of the planned medialization. A strong linear correlation was found between the degree of correction of retroversion and the amount of medialization (R = 0.82; P< .001).Conclusion3D preoperative planning and PSI guided correction of deformed modified-type B glenoids resulted in accurate postoperative correction of the glenoid deformity, correct glenoid component implantation with low deviation from the planned position and excellent short-term functional and radiographic results.Level of Evidence: Level IV; Case Series; Treatment Study.     

Comparison of two-dimensional manual and three-dimensional SurgiCase and BLUEPRINT planning software measurements of glenoid version,inclination, and humeral subluxation

IntroductionVirtual planning for shoulder arthroplasty using preoperative computed tomography (CT) has been gaining popularity, and it is imperative for surgeons to recognize any differences in measurements that may exist amongst software platforms. The purpose of this study is to compare measurements of glenoid version, inclination, and humeral head subluxation between a manual approach and two varying automated software platforms using either a best-fit sphere technique (Wright-Medical BLUEPRINT) or an anatomic landmarks technique (Materalise SurgiCase).MethodsA case control study of 289 CT images from patients preoperatively planned for a total shoulder arthroplasty or reverse shoulder arthroplasty using SurgiCase (v3.0.110.5) were also successfully analyzed by BLUEPRINT (v2.1.6). Glenoid version, inclination, and subluxation were measured manually in a blind fashion by two separate investigators using axial and coronal images oriented to the scapular plane; interobserver and intraobserver reliabilities were measured using intraclass correlation coefficients (ICCs). Concordance correlation coefficients (CCCs), mean differences, and clinically relevant agreement in measurements between the software platforms and with the manual technique were compared. The impact of greater glenoid retroversion on the differences in measurements between the software platforms was further studied by correlation analysis.ResultsThe mean differences between SurgiCase and BLUEPRINT were + 0.5° for glenoid inclination (P = .064; CCC = 0.84), -0.9° for glenoid version (P < .001; CCC = 0.92), and -1.4% for humeral subluxation (P = .002; CCC = 0.88). Agreement within 5 units was 78.9% for inclination, 89.3% for version, and 64.1% for subluxation. Glenoid retroversion had no relation with the degree of variation in measured inclination (P = .59) or version (P = .56). There were significant differences between manual and 3D software measurements for glenoid inclination, version, and subluxation (P < .001). Both software measurements were more inferiorly inclined (average difference, SurgiCase -3.2° and BLUEPRINT -3.9°), more retroverted (average difference, SurgiCase -4.0° and BLUEPRINT -3.2°), and more posteriorly subluxated (average difference, SurgiCase + 3.4% and BLUEPRINT + 4.8%).ConclusionThe SurgiCase and BLUEPRINT preoperative planning software yield clinically similar measurements for glenoid version, inclination, and subluxation. The degree of glenoid retroversion does not impact the variability of inclination or version between the landmark and best-fit sphere software techniques. Compared to the 2D manual technique, both 3D software programs reported greater inferior inclination, retroversion, and posterior subluxation.Level of evidenceLevel III; Retrospective Diagnostic Study     

Computed tomography revealed the correlation between radiolucency and alignment of all-polyethylene pegged glenoid component more than 10 years after total shoulder arthroplasty in the Japanese population

BackgroundAnatomical total shoulder arthroplasty (TSA) provides successful long-term outcomes but complications can occur after 10 years that require revision. Computed tomography (CT) is a useful tool for assessing radiolucent lines around the glenoid component of TSA; however, the merits of long-term post-TSA follow up with CT are unclear. The purpose of this study was to evaluate the long-term outcomes after TSA of Japanese population and to identify factors related to radiolucency around the glenoid component using CT.MethodsA retrospective review was conducted of TSA patients who had completed at least 10 years of clinical follow up. Radiographs and CT images of the affected shoulder obtained at the last follow up were evaluated for radiolucent lines around the stem and each peg, superior inclination and retroversion of the glenoid component, subluxation index, and critical shoulder angle (CSA). Shoulder ROM, Constant–Murley score and UCLA score were compared between the preoperative and last follow up period.ResultsEighteen shoulders in 16 patients met the inclusion criteria. Mean patient age was 61 years, mean follow up period was 137 months, and mean Yian CT score was 19%. CT score was significantly highest in pegs located inferiorly (p < 0.05). Mean glenoid superior inclination was 12.6°, retroversion was ?0.3°, subluxation index was 46%, and CSA was 33.7°. Glenoid superior inclination was significantly lower (p = 0.007) in shoulders with possible loosening than in cases with no loosening (5.0° vs 15.6°). Mean Constant score and UCLA score improved significantly after TSA, from 25.8 to 10.7 points preoperatively to 70.1 and 28.9 points postoperatively, respectively. Mean shoulder flexion, internal rotation, and external rotation also showed improvement postoperatively.ConclusionTSA provides good long-term outcomes. Radiolucency was present most frequently around the inferior pegs of the glenoid component. Glenoid superior inclination may affect the formation of radiolucent lines around glenoid pegs.Level of evidenceLevel IV; Case Series; Treatment study.     

Clinical application of intraoperative O-arm navigation in reverse shoulder arthroplasty

BackgroundInaccurate fixation and positioning of the glenoid component using conventional techniques are problematic in reversed shoulder arthroplasty (RSA). Our objective was to investigate the accuracy of O-arm navigation of the glenoid component in RSA.MethodsThis retrospective case–control study comprised 2 groups of 25 patients who underwent reversed shoulder arthroplasty with or without intraoperative O-arm navigation. The intraoperative goal was to place the component neutrally in the glenoid in the axial plane and 10° inferiorly tilted in the scapular plane. Glenoid version angle and inclination were measured by computed tomography obtained preoperatively and a year postoperatively. Operative time, intraoperative bleeding, and the presence of postoperative complications were recorded.ResultsCompared with the ideal, the range of error for version was 7.3° (SD 3.6°) in the control group and 5.6° (SD 3.6°) in the navigated group (P = 0.278), and the range of error for inclination was 18.3° (SD 11.7°) in the control group and 4.9° (SD 3.8°) in the navigated group (P = 0.0004). The mean operative time was 164.6 (SD 21.2) min in the control group and 192.0 (SD 16.2) min in the navigated group (P = 0.001). The mean intraoperative bleeding was 201.0 (SD 37.0) mL in the control group and 185.3 (SD 35.6) mL in the navigated group (P = 0.300). There were no complications reported related to the intraoperative O-arm navigation.ConclusionO-arm navigation may be a useful tool for the placement with inferior tilt of the glenoid procedure in reversed shoulder arthroplasty.     

Mixed-reality holographic-assisted placement of glenoid guidewire in shoulder arthroplasty: preliminary comparison to patient-specific instrumentation in B2 glenoid model

BackgroundThree-dimensionally (3D) printed patient-specific instrumentation (PSI) guides and computer navigation are 2 forms of commercially available options for improved accuracy of glenoid guide pin placement during shoulder arthroplasty. Mixed reality (MR) and virtual reality devices have been used in medical education thus far, but there has been limited assessment of their intraoperative viability in specific settings such as shoulder arthroplasty. The purpose of this study was to compare the accuracy of MR holographic model–assisted glenoid guidewire placement to freehand (FH) and PSI options.MethodsSixty 3D printed glenoid polyurethane sawbones models with a B2 glenoid defect were created. The 3D model of the B2 glenoid with a guide pin in place was programmed into a Unity-based application installed on the Microsoft HoloLens2 MR device. In randomized fashion, 5 surgeons placed a guide pin into the “sawbones” models using FH, PSI, or MR with the attempt to replicate the desired preoperative plan. Using fine-cut computed tomography, average version, average inclination, and starting point were analyzed among all models and surgeons.ResultsThe average starting point from the plan for the FH group was 2.21 ± 0.95 mm, 2.27 ± 0.80 mm for the PSI group, and 1.745 ± 0.84 mm for the MR group, P = .12. The average inclination was 10.56 ± 7.37 degrees, 3.02 ± 3.36 degrees, and 8.16 ± 5.69 degrees for the FH, PSI, and MRI groups, respectively, P = .0004. The average version was 13.52 ± 9.21 degrees, 7.26 ± 4.64 degrees, and 12.36 ± 9.19 degrees for the FH, PSI, and MRI groups, respectively, P = .04. Subgroup analysis of FH to PSI and PSI to MR demonstrated significantly less inclination from plan in the PSI group, P = .0003 and P = .02, respectively. There were no differences in version in the subgroup analysis between the FH and MR and PSI and MR groups. Degrees of deviation of inclination from plan were significantly less when comparing all models among more experienced surgeons, P = .026, whereas no statistical differences in deviation of start point or version were noted across all models in the more experienced group. When further analyzing the inclination among the FH, PSI, and MR groups among higher level surgeons, the PSI model demonstrated less deviation from plan compared to the FH model, P = .02, but there were no differences in inclination when comparing the PSI to MR and MR to FH models.ConclusionMR permits accurate glenoid guide pin placement comparable to FH placement in a polyurethane B2 glenoid bone substitute model.     

Humeral osteophyte size and clinical outcomes after anatomic total shoulder arthroplasty

BackgroundThe severity of primary glenohumeral osteoarthritis (PGOA) has been associated with advanced radiographic findings including inferior humeral head osteophytes. The primary objective of this study is to analyze for any correlation between the size of the inferior humeral head osteophyte and functional outcomes in patients undergoing anatomic total shoulder arthroplasty (TSA) for PGOA.MethodsA retrospective review of a multi-surgeon database was performed to identify all patients with PGOA from 2015 to 2019 with a minimum of two-year clinical follow-up. Preoperative anteroposterior and Grashey views were used for all included patients to obtain measurements of the inferior humeral osteophyte. Two groups at the extremes of osteophyte width were identified: 1) patients with absent or minimal osteophytes (lowest quartile of width, < 4.9 mm) and those with large osteophytes (highest quartile of width, > 10.1 mm). Change in active range of motion (ROM) from baseline, patient-reported outcomes (PROs), strength and complications were assessed at a minimum of 2 years postoperatively and compared between the two groups.ResultsDemographics were similar for the large osteophyte group (n = 57) and small osteophyte group (n = 56). There was a higher percentage of patients with more significant glenoid deformity in the large osteophyte group compared to the small osteophyte group (P = .009 for A1 deltoid). The large osteophyte group had significantly more restricted preoperative ROM for all measures (P < .05 for all). There were no significant differences in final ROM achieved between the two groups. Patients in the large osteophyte group had greater improvement from baseline for external rotation at the side (31° vs 21°, P = .015), external rotation at 90° abduction (38° vs 20°, P = .004), and internal rotation at 90° abduction (30° vs 12°, P < .001) compared to the small osteophyte group. Overall, there were very few differences between the small and large osteophyte groups in final PROs, with the exception of a higher American Shoulder and Elbow Surgeons score in the large osteophyte group (90.8 vs 85.9, P = .048).ConclusionPatients with large humeral osteophytes have significantly greater restrictions in preoperative ROM compared to patients with small osteophytes. Patients with large osteophytes experience greater improvements in rotational motion after anatomic TSA compared to patients with small osteophytes, although the final ROM achieved was similar between groups. Overall, PROs after anatomic TSA were similar between patients with small and large osteophytes preoperatively.     

Baseplate augmentation strategies: optimizing range of motion with reverse shoulder arthroplasty based upon variable glenoid deformity

IntroductionVarious operative strategies exist to address glenoid deformity in patients undergoing reverse shoulder arthroplasty (RSA). There is lack of guidance in pairing operative strategies with type and severity of deformity especially with regard to glenoid lateralization, humeral lateralization, and global lateralization. The purpose of this study is to compare different glenoid baseplates on their ability to provide optimal glenoid lateralization and improve range-of-motion based upon pattern and severity of deformity in glenohumeral osteoarthritis.MethodsCT scans were chosen from a large database of osteoarthritic shoulders until ten from each of the following three cohorts were identified: 1) no deformity: retroversion <10° and inclination deformity <5°, 2) Uniplanar deformity: retroversion >15° and inclination <10° or, 3) biplanar deformity: retroversion >15° and inclination >15°. Imascap SAS (Wright Medical) was used to quantify deformities and plan RSA placement. Each case was planned with the following baseplates: standard implant, three mm lateralized, wedge augment, and patient-specific implant. Each baseplate was placed in 5° of retroversion and neutral inclination and medialized to 70% seating. Percent seating, amount of reaming, global lateralization, and simulated range of motion (ROM) was recorded for each scenario.ResultsThe average patient age was 65.4 (49-78) and 14 (47%) were women. Ten of thirty (33%) were classified as Walch A1 or A2, 19/30 (63%) were B1, B2, or B3, and 1/30 (5%) was a C. The normal, uniplanar, and biplanar groups had mean retroversion deformities of 2.1° (-3- 8°), 28.4° (22-36°), and 29.3° (19-39°) respectively. Across the three cohorts, increased global lateralization through glenoid-sided lateralization provided improved ROM most significantly in adduction (R = 0.82; P <.001), flexion (R = 0.78; P <.001), and external rotation (R = 0.76; P <.001). In the nodeformity cohort, less global lateralization was needed for improved range of motion compared to uniplanar and biplanar cohorts. In uniplanar deformities, the wedge augment provided similar amounts of added global lateralization as the patient-specific augment (7.2 mm vs 8.5mm; P = .06) and was equally able to improve range of motion. In the biplanar group, the patient-specific provided greater global lateralization than wedge augment when compared to standard implants (10.1mm vs 7.1mm; P = .002) and improved ROM.ConclusionWhen RSA is used in the treatment for glenohumeral arthritis, the degree of deformity should be considered when choosing baseplate implants. Increased global lateralization is needed to optimize ROM in the setting of severe deformities and in select cases an augment wedge or patient-specific implant construct should be considered.Level of EvidenceLevel III, retrospective comparative study.     

Clinical and radiographic results of eccentric glenoid reaming in reverse total shoulder arthroplasty

BackgroundOne option for treating glenoid bone loss in reverse shoulder arthroplasty (RSA) is eccentric reaming of the glenoid, but the effect on clinical results is unclear. The aim of this study was to investigate the association between medialization of the bone-baseplate interface (herein, ‘medialization’) caused by eccentric reaming of the glenoid and scapular notching, baseplate loosening, and clinical outcomes after RSA.MethodsWe retrospectively reviewed data for 91 patients who underwent primary RSA between January 2014 and December 2016 with a lateralized implant and a minimum 2-year follow-up. The amount of medialization was estimated using a 3-dimensional computed tomography scan-based computer planning software. The average amount of medialization estimated by the 3-dimensional planning software was 3.4 mm (range, 0.5-10 mm). Outcomes included range of motion (ROM), American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST) score, visual analog scale (VAS) for pain, and the rates of scapular notching and baseplate loosening. The association between the estimated medialization and the outcomes of interest was evaluated using multivariate models.ResultsAfter controlling for age, sex, diagnosis, subscapularis repair, glenosphere size, and baseline ROM, medialization was not associated with the postoperative abduction (P = .35), external rotation (ER) at 90° (P = .16), internal rotation at 90° (P = .08), and internal rotation at the back (P = .06). However, we found a significant association between medialization and postoperative ER at the side (P = .02). According to the multivariate model, for a 1-mm increase in medialization during surgery, a decrease of 1.6° in postoperative ER would be expected. We found no association between medialization and the postoperative ASES score (P = .48), SST score (P = .59), or VAS score (P = .27). At a minimum of 2 years of follow-up, we found no baseplate loosening or radiographic signs of baseplate loosening in any patient. Scapular notching of grades 1 to 2 was observed in 22 patients (24%). We were not able to detect a difference in scapular notching when medialization was > 1 mm ver when medialization ≤ 1 mm (odds ratio, 2.5; 95% confidence interval: 0.28-23).ConclusionsIncreasing medialization due to eccentric reaming after RSA with a lateralized implant was associated with a decrease in postoperative ER at the side. However, increasing medialization was not associated with worse patient-reported outcome scores or increased baseplate loosening at short-term follow-up.     

Does critical shoulder angle predict abduction motion and acromion-tuberosity impingement in reverse shoulder arthroplasty?

BackgroundVirtual planning software for reverse shoulder arthroplasty (RSA) has introduced the ability to optimize implant position in an effort to maximize bony impingement–free motion. Abduction impingement typically occurs between the glenoid and polyethylene or between the tuberosities and the acromion or coracoid. Acromion-tuberosity impingement has been considered less desirable, as it may create additional stress on the acromion. Patients with a large acromion overhang may have higher rates of acromion-tuberosity impingement. As the critical shoulder angle (CSA) represents a larger distance from the glenoid face to the acromion, the purpose of this study was to evaluate the impact of implant selection and position on abduction motion and acromion-tuberosity impingement, with a focus on the association to CSA. We hypothesize that a larger CSA will be associated with less abduction motion and an increase in acromion-tuberosity impingement.MethodsThis is a retrospective cohort case series of 85 consecutive patients who underwent RSA from June 2020 to January 2021. Humeral and glenoid components were implanted virtually (SurgiCase) using a standard protocol for a single implant system (DJO AltiVate Short Stem Reverse) with an inset humeral component. Implant variables analyzed included baseplate location (central vs. inferior glenoid), glenosphere lateralization (10 mm vs. 6 mm), and humeral shell (standard vs. semiconstrained). The maximal degree of abduction and location of impingement were recorded at external rotation of 0°, 45°, and 90°. Implant combinations that resulted in no impingement and no motion were recorded.ResultsIncrease in CSA was associated with acromion-tuberosity impingement for nearly every combination at 0° and 45° external rotation; however, there were no significant associations between CSA and maximum abduction motion. Acromion-tuberosity impingement was associated with central glenosphere placement in all degrees of external rotation (P < .001), use of a 10 mm lateralized glenosphere for 0° (P < .001) and 45° (P = .076), and using a standard polyethylene shell for 0° (P = .032) and 45° external rotation (P = .007). Maximal abduction motion was associated with inferior placement (P < .001), and use of a 10 mm lateralized glenosphere (P < .001) in all positions of external rotation but was not influenced by the polyethylene type.ConclusionIncreased CSA is associated with acromion-tuberosity impingement and can be used to screen for patients at risk for bony impingement in abduction. Placement of the glenosphere centrally and use of a 10 mm lateralized glenosphere were associated with higher rates of acromion-tuberosity impingement. Maximal abduction can be achieved using a 10 mm lateralized glenosphere and inferior placement.     

The Glenoid Vault Outer Cortex (GVOC) radiological reference for shoulder arthroplasty evaluated in aging scapulae

BackgroundAccurate glenoid component positioning is an important determinant of outcome in a shoulder arthroplasty surgery. Optimal glenoid placement is determined using bony landmarks of the scapula. The Glenoid Vault Outer Cortex (GVOC) has been recently described as a new, more accurate radiological reference. This has, however, only been evaluated against current standard references in young patients. Further investigation of the GVOC in older patients is therefore warranted. We, therefore, evaluated the effect of aging on the accuracy and stability of the GVOC, in determining glenoid anatomy as compared to the commonly used Scapular Border (SB) plane.MethodsComputed tomography imaging of 129 individual scapulae was obtained retrospectively from a cohort of patients who had undergone either total body or region-specific computed tomography imaging which included the shoulder region. This comprised of 35 males and 33 females (64 and 65 scapulae respectively) who were aged from 30 to 92 years. Imaging of 54 scapulae was from patients aged ≥60 years. The accuracy of the GVOC plane was then assessed against the SB plane.ResultsIn all patients, the mean difference between estimates using the GVOC plane and the GR (actual) was 2.2° (standard deviation [SD], 4.2) for version, and 1.8° (SD, 4.9) for inclination (P < .001). This contrasted with values of 7.6° (SD, 7.6) for version, and 22.9° (SD, 10.8) for inclination when using the SB reference plane (P < .001). Within the group aged ≥60 years, the mean difference between estimates using the GVOC plane and the glenoid rim (actual) was 3.2° (SD, 4.7) for version and 1.9° (SD, 3.1) for inclination, (P < .001). This contrasted to 10.0° (SD, 7.2) for version, and 23.4° (SD, 10.7) for inclination when using the SB plane (P < .001).Separately it was noted that the GVOC’s relationship to the glenoid rim remained constant throughout aging as opposed to the SB which changed significantly over time effecting estimates of glenoid retroversion.ConclusionsThe GVOC is a new plane of reference developed specifically for the use in shoulder arthroplasty. It is shown to be more accurate and stable in the aging scapulae than the currently used SB plane. The future development of guides and planning softwares that utilize the GVOC may provide an important opportunity for improved accuracy and outcome in shoulder arthroplasty.     

Arthroscopic glenoid removal for aseptic loosening in total shoulder arthroplasty

BackgroundGlenoid loosening is the most common long-term complication of total shoulder arthroplasty (TSA) and frequently necessitates revision. Though arthroscopic glenoid removal is an accepted treatment option for glenoid loosening, there is a paucity of outcomes literature available. The purpose of this study was to report the long-term clinical and radiographic outcomes of arthroscopic glenoid removal for failed or loosened glenoid component in TSA. We hypothesized that arthroscopic glenoid removal would produce acceptable clinical and patient-reported outcomes while limiting the need for further revisions.MethodsThis was a retrospective analysis of 11 consecutive patients undergoing 12 arthroscopic glenoid removals for symptomatic glenoid loosening by a single orthopedic surgeon between March 2005 and March 2018. Indication for arthroscopic glenoid removal included symptomatic glenoid loosening with radiographic evidence of a 1-2 mm radiolucent line around the glenoid. Shoulder range of motion, functionality (American Shoulder and Elbow Surgeons, Simple Shoulder Test), and pain (visual analog scale [VAS]) were evaluated. Radiographs were assessed for glenohumeral subluxation, humeral superior migration, and glenohumeral offset following glenoid removal.ResultsThe mean follow-up period since arthroscopic glenoid removal was 55 months (range, 20-172 months). Glenoid component removal significantly reduced forward elevation, with a mean decrease from 147 ± 13° preoperatively to 127 ± 29° postoperatively (P= .031). However, there was no significant change in external rotation (44 ± 9° vs. 43 ± 19°; P= .941) or internal rotation (L4 vs. L4; P= .768). Importantly, glenoid removal significantly decreased VAS pain scores from 7 ± 3 preoperatively to 5 ± 3 postoperatively (P= .037). Additionally, improvement in ASES approached statistical significance, increasing from 33 ± 25 preoperatively to 53 ± 28 postoperatively (P= .055). With regard to radiographic outcomes, there was no evidence of glenohumeral subluxation and humeral superior migration developed in 1 patient. However, there was significant medialization of the greater tuberosity relative to the acromion, with a mean lateral offset of 6 ± 7 mm preoperatively and −2 ± 4 mm postoperatively (P= .002). Two patients required conversion to reverse TSA for persistent pain. There were no complications.DiscussionThese findings suggest that arthroscopic glenoid removal for symptomatic glenoid loosening is a viable option to improve pain while limiting the need for additional reoperations and decreasing the risks associated with revision arthroplasty. However, continual follow-up to monitor medialization is recommended.Level of EvidenceLevel IV; Case Series; Treatment Study     

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.     

Arthroscopic glenoid removal for symptomatic component loosening in anatomic total shoulder arthroplasty: can it work?

BackgroundGlenoid loosening is a common cause of failure in anatomic total shoulder arthroplasty (aTSA). Arthroscopic evaluation and removal of the loose glenoid component is a treatment option, but data on this technique is limited. The purpose of this study was to evaluate the outcomes following arthroscopic glenoid removal for aTSA patients with symptomatic glenoid loosening.MethodsA retrospective case series was performed to identify aTSA patients with symptomatic glenoid component loosening, who underwent arthroscopic evaluation and glenoid removal from 2005-2019. Date of index shoulder arthroplasty, culture results, and any subsequent revision shoulder procedures were documented. All patients were contacted via telephone to obtain American Shoulder and Elbow Surgeons, Simple Assessment Numeric Evaluation, satisfaction scores (0-100), reoperation performed at an outside facility, and whether they would undergo the operation again.ResultsTwenty-three patients were identified who underwent arthroscopic glenoid removal, of which 20 (87%) were available for a follow-up. Patients had a mean age of 65.6 ± 11.9 years, body mass index of 29.4 ± 6.2 kg/m², and 12/20 were females (60%). The average time from index aTSA to arthroscopic glenoid removal was 7.0 ± 3.6 years (range, 1.9-11.9 years). All patients had loose glenoids at the time of arthroscopic evaluation and 5 patients (25%) had concurrent rotator cuff tears. All patients had cultures obtained at the time of arthroscopy and none were positive. Five patients (25%) underwent revision to reverse total shoulder arthroplasty at a mean 7.4 ± 4.2 months, for a survival of 75% at final follow-up. Comparing patients who underwent revision to those who did not, there was no difference in age (61.0 ± 9.2 vs. 67.1 ± 12.6 years, P = .34), body mass index (29.8 ± 9.5 vs. 29.2 ± 5.1 kg/m², P = .86), sex (100% vs. 47% female, P = .06), time from index aTSA to glenoid removal (63.0 ± 38.4 vs. 91.4 ± 43.9 months, P = .34), or presence of rotator cuff tear (20% vs. 27%, P = 1.0). Of the 15 patients (75%) who did not undergo reoperation, the average American Shoulder and Elbow Surgeons, Simple Assessment Numeric Evaluation, and Satisfaction scores were 54.3 ± 29.2, 53.5 ± 27.6, and 65.9 ± 37.9 respectively, at an average follow-up of 36.0 ± 19.5 months (range, 12-67 months). No patient (0%) who underwent reoperation would undergo the arthroscopic glenoid removal again, whereas 12 patients (60%) who did not undergo reoperation would choose to have an arthroscopic glenoid removal again.ConclusionsGlenoid loosening is an unfortunate complication of aTSA. Survival was 75% for patients who underwent arthroscopic glenoid removal with modest patient reported outcomes. In appropriately selected patients, arthroscopic glenoid removal is a reasonable treatment option to consider for symptomatic glenoid component loosening.     

Comparison of mid-term outcomes of total shoulder arthroplasty for B2 and A glenoids treated with trabecular metal glenoid components

BackgroundTreatment of B2 glenoids in total shoulder arthroplasty (TSA) has been associated with worse clinical outcomes and increased rates of glenoid loosening. The purpose of this study was to describe and compare the mid-term outcomes of TSA using a trabecular metal-backed glenoid in patients with B2 and A glenoids.MethodsPatients who underwent anatomic TSA with a trabecular metal-backed glenoid component (second generation trabecular metal glenoid) for primary osteoarthritis and had minimum 5-year follow-up were reviewed. All patients underwent eccentric glenoid reaming to treat biconcavity, if present. Preoperative imaging was reviewed and patients were divided into 2 groups: Type A and Type B2. Mid-term outcome measures including patient-rated outcome scores (Patient Reported Outcome Measurement Information System and American Shoulder and Elbow Surgeons [ASES]) and shoulder range of motion were determined. ASES score was compared between groups. Radiographs were graded for radiolucent lines and posterior humeral head migration and evaluated for glenoid loosening.ResultsTwenty-two patients had Type A glenoids and 22 patients had B2 glenoids. Sixteen patients in the A group and 18 patients in the B2 group had full radiographic and physical exam follow-up. Both groups had similar follow-up (6.7 ± 1.1 years A, 6.6 ± 0.9 years B2, P = .88). Groups were similar in terms of age at surgery, gender distribution, body mass index, severity of medical comorbidities, and hand dominance distribution. The B2 patients had a mean preoperative glenoid retroversion of 17.5° ± 6.7° and posterior subluxation of 8.5% ± 5.3%. No patients in either group had evidence of glenoid loosening at follow-up. No patients required revision surgery. Nine of 16 in the A group had evidence of mild radiolucent lines (8 grade 1, 1 grade 2). Eight of 18 patients in the B2 group had mild radiolucencies (all grade 1). Two of 16 Type A and 6 of 18 B2 patients had evidence of posterior humeral migration, but all cases were graded as mild. Both groups had similar follow-up mean ASES scores (95.5 A, 89.0 B2, P = .25).ConclusionAt minimum 5-year follow-up, patients who underwent TSA with a trabecular metal-backed glenoid component demonstrated excellent clinical and patient-reported outcomes regardless of preoperative glenoid morphology (A or B2). No patients in either group had evidence of glenoid loosening or required revision surgery. These favorable mid-term outcomes of trabecular metal-backed glenoids in B2 deformities need to be followed longitudinally to determine long-term durability.Level of EvidenceLevel III; Retrospective Comparative Study     

Evaluating Alternate Registration Planes for Imageless,Computer-Assisted Navigation During Total Hip Arthroplasty

BackgroundImageless computer navigation improves component placement accuracy in total hip arthroplasty (THA), but variations in the registration process are known to impact final accuracy measurements. We sought to evaluate the registration accuracy of an imageless navigation device during THA performed in the lateral decubitus position.MethodsA prospective, observational study of 94 patients undergoing a primary THA with imageless navigation assistance was conducted. Patient position was registered using 4 planes of reference: the patient’s coronal plane (standard method), the long axis of the surgical table (longitudinal plane), the lumbosacral spine (lumbosacral plane), and the plane intersecting the greater trochanter and glenoid fossa (hip-shoulder plane). Navigation measurements of cup position for each plane were compared to measurements from postoperative radiographs.ResultsMean inclination from radiographs (41.5° ± 5.6°) did not differ significantly from inclination using the coronal plane (40.9° ± 3.9°, P = .39), the hip-shoulder plane (42.4° ± 4.7°, P = .26), or the longitudinal plane (41.2° ± 4.3°, P = .66). Inclination measured using the lumbosacral plane (45.8° ± 4.3°) differed significantly from radiographic measurements (P < .0001). Anteversion measured from radiographs (mean: 26.1° ± 5.4°) did not differ significantly from the hip-shoulder plane (26.6° ± 5.2°, P = .50). All other planes differed significantly from radiographs: coronal (22.6° ± 6.8°, P = .001), lumbosacral (32.5° ± 6.4°, P < .0001), and longitudinal (23.7° ± 5.2°, P < .0001).ConclusionPatient registration using any plane approximating the long axis of the body provided a frame of reference that accurately measured intraoperative cup position. Registration using a plane approximating the hip-shoulder axis, however, provided the most accurate and consistent measurement of acetabular component position.     

Prognostic factors and clinical features in metacarpophalangeal joint hyperextension after ligament reconstruction with trapeziectomy: A retrospective cohort study

BackgroundManagement of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes.MethodsWe investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°–20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR).ResultsOverall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821).ConclusionsPostoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.     

Implantation accuracy of custom-made glenoid implants for treating severe glenoid bone deficiencies with reverse shoulder arthroplasty

BackgroundCustom-made three dimensional–printed glenoid implants for reverse shoulder arthroplasty are a modern treatment option for severe glenoid bone deficiencies. The potential advantages of not only achieving primary stability but also being able to realize the preoperative plan in terms of implantation accuracy at the same time have not yet been sufficiently investigated. The purpose of this study was to quantify the implantation precision of custom-made glenoid implants.MethodsTwelve consecutive patients with severe glenoid bone defects were treated between May 2019 and August 2020 using a custom-made glenoid implant (ProMade) (LimaCorporate, San Daniele, Italy) with reverse shoulder arthroplasty at a single hospital. All patients were eligible for inclusion and could be enrolled in this institutional review board–approved study. The immediate postoperative computer tomography–evaluated position of the glenoid implant was compared with the preoperative computer-based plan, on which the manufacturing process was based. As a result of this comparison, deviation measurements in six degrees of freedom (inclination, version, mediolateral offset, anteroposterior offset, superoinferior offset, and roll rotation) emerged.ResultsThe absolute average (mean value ± standard deviation) implantation deviation related to the plan was 1.6° ± 5.4° for version, 1.9° ± 4.1° for inclination, 0.3 mm ± 3.3 mm for mediolateral offset, 0.1 mm ± 1.9 mm for anteroposterior offset, 0.0 mm ± 2.4 mm for superoinferior offset, and 1.0° ± 6.3° for roll rotation. The augment volume averaged 9.0 cm³ ± 2.6 cm³. All custom-made glenoid implants were implanted with a subjectively sufficient primary stability.ConclusionThis study gives an indication that custom-made three dimensional–printed glenoid implants can be implanted with statistically high accuracy. To evaluate the clinical benefit and radiographic stability, a longer follow-up investigation is needed.     

Correcting retroversion during reverse shoulder arthroplasty for B2 glenoids leads to medialization and worsens impingement on the scapular neck

BackgroundReverse shoulder arthroplasty (RSA) is a viable option for posteriorly-eroded B2 glenoids. But little is known in this setting about the effect of baseplate version on impingement on the scapular neck, which affects the risk of notching, the risk of impingement-related instability, and the passive range of motion (ROM). Correcting retroversion with eccentric reaming leads to medialization to achieve full support of the baseplate, bringing the humerus closer to the scapula and potentially increasing impingement on the scapular neck. We hypothesized that correcting retroversion in B2 glenoids would result in increased medialization and worse impingement on the scapular neck.MethodsTen patients with Walch B2 glenoids underwent a simulated RSA. For each patient, a 25 mm baseplate was digitally implanted along the inferior margin of the glenoid, centered anterior-to-posterior, in 0˚ of inclination, with 100% backside contact, with a 36 mm glenosphere and 145˚ neck-shaft angle. Impingement-free ROM was then simulated with 17 different implant arrangements: baseplate version of P (the pathologic version), −15˚, -10˚, −5˚, 0˚, and baseplate lateralization +0, +3mm, +6mm. Two additional simulations consisted of half-wedge baseplates seated at the best fit (matching the paleoglenoid) and 0˚ version. The primary endpoint was external rotation at the side (ERS), based on in-vivo analyses that reveal this as the primary mode of notching and impingement-related instability. Data was analyzed using paired t-test, analysis of variance (ANOVA), and a multivariable regression analysis.ResultsIn every simulation in every patient, correcting retroversion worsened scapular neck impingement with ERS, the primary mode of notching and impingement-related instability. Overall, implantation in retroversion led to 33% more ERS (P = .02). The magnitude of this effect was much greater with medialized glenoids: 100% more ERS for +0 baseplates and 23% more ERS for +6 (P = .008). Half-wedge baseplates resulted in more ERS than +0 baseplates: 2.3x more at 0˚ version (P = .02). Any correction of version resulted in increased medialization (all P < .01), which led to worse scapular neck impingement. Multiple linear regression analysis showed that baseplate lateralization has the most impact on scapular neck impingement (β = 0.640; P < .001).ConclusionIn B2 glenoids undergoing RSA, correcting the glenoid retroversion with eccentric reaming results in significantly more medialization, worsening scapular neck impingement with ERS. This can increase the risk of notching, may lead to impingement-related instability, and decreases passive ERS.Level of evidenceClinical science study