Virtual Surgical Guidance Improves Quality of Life Following Scapular Free-Flap Reconstruction of Maxillary Defects.

BACKGROUND: The best approach to maxillary reconstruction with negative impact on the patient's quality of life (QOL) remains the subject of debate. PURPOSE: This study was designed to evaluate the QOL outcomes following maxillary reconstruction using a scapular-free flap, with and without the computer-aided design and computer-aided manufacturing (CAD/CAM) technique. STUDY DESIGN, SETTING, SAMPLE: A prospective randomized controlled clinical trial was performed following the CONSORT checklist. To be included, patients suffering from maxillary defects without previous surgery or lymph node involvement were selected. Patients with poor oncological prognosis, deficient performance status, preoperative chemotherapy, or radiotherapy, besides vascular contraindications, were excluded. PREDICTOR VARIABLE: The predictor variable was the reconstruction technique, grouped into two equal categories. Patients were randomly assigned to reconstruction with a scapular-free flap, with the control group not utilizing a guide and the study group utilizing a CAD/CAM-customized guide. MAIN OUTCOME VARIABLE: The primary outcome variable was the various domains of QOL, measured using the University of Washington Quality of Life score, 12 months after reconstruction. COVARIATES: Age; sex; scapular flap side; and maxillary defect tumour type, histopathology, side, length, class, sagittal, and axial differential areas were considered. ANALYSES: Shapiro-Wilk and Kolmogorov-Smirnov tests were performed for normality. For comparisons between the two groups, Student's t-test and Mann-Whitney test were used. The category variables were compared using the χ2 test. P ≤ .05 was considered statistically significant. RESULTS: The sample was composed of twenty-two eligible patients, eleven in each group. The mean age of the control group was (50.09 ± 17.14) years, and 45.45% were male, while in the study group, the mean age was (48.36 ± 14.14) years, with 36.36% male. All the patients were evaluated, showing statistically significant differences between control and study groups in terms of pain, appearance, chewing, swallowing, speech, and shoulder (P ≤ .05), indicating that the scapular-free flap with a CAD/CAM osteotomy guide had improved the patient's QOL. CONCLUSION AND RELEVANCE: The findings of this study indicate that virtual surgical planning with a CAD/CAM customized osteotomy guide using a scapular-free flap can improve QOL in maxillary reconstruction in terms of pain, appearance, chewing and swallowing food, pronouncing words, and shoulder QOL outcomes.

Arthroscopic reduction and hollow screw internal fixation for Eyres Type IIIA scapular coracoid fracture: a case report.

BACKGROUND: A coracoid process fracture combined with an acromioclavicular (AC) joint dislocation is an uncommon injury that typically causes significant pain and limits shoulder movement. Open reduction and internal fixation have been the traditional treatment approach. However, arthroscopic techniques are emerging as a promising alternative for managing these injuries. CASE REPRESENTATION: A 35-year-old woman presented with right shoulder pain following an accidental fall. Imaging studies revealed a coracoid process fracture along with an AC joint dislocation. The fracture was classified as an Eyres Type IIIA, which warranted surgical intervention. Our team performed arthroscopic coracoid fracture reduction and internal fixation surgery, as well as AC joint dislocation repair using Kirschner wires. Six months after surgery, the patient demonstrated a satisfactory functional outcome with complete bone healing. CONCLUSION: This case report highlights the potential of arthroscopic reduction and fixation as a novel treatment option for fractures of the coracoid base.

Editorial Commentary: Button Fixation for Glenoid Bone Grafting Results in Less Graft Resorption Compared to Screws.

Iliac crest bone grafting is conducted in cases of anteroinferior shoulder instability with substantial bone loss of the glenoid rim to reconstruct the glenoid concavity and its stabilizing function. The technique is more than 100 years old, and it evolved to include graft fixation with metal screws. The disadvantages of metal screw fixation include risk of screw migration, loosening, and breakage, as well as irritation and injury to the surrounding osseous and soft tissue structures (e.g., humeral cartilage and subscapularis muscle). With the implementation of arthroscopic techniques, new graft fixation techniques were introduced, including absorbable or biologic screws, buttons, interconnected suture anchors, and bone cerclage techniques. Recent research shows button fixation is a successful alternative to screw fixation. In addition, buttons show less graft resorption and related pain.

Posterior Glenoid Bone Block Reconstruction: Indications, Techniques, and Outcomes.

Posterior shoulder instability is of particular therapeutic interest, as it typically affects patients with high functional demands such as young athletes and active adults. Although posterior capsulolabral repair has high return-to-sport rates, it is associated with recurrent instability of up to 11%. Posterior glenoid bone loss and significant glenoid retroversion have been identified as risk factors for recurrent instability and failure after primary arthroscopic soft-tissue repair. Therefore, posterior glenoid bone block reconstruction may be indicated for glenoid bone loss 20% or greater (as measured by the perfect circle technique) or greater than 10% in the setting of pathologic glenoid, failed primary posterior labral repair, incompetent posterior capsular tissue, or significant risk factors for failure of soft-tissue repair. This procedure may be performed arthroscopically or with a posterior open approach using distal tibial allograft, iliac crest autograft, or scapular spine autograft. Although short-term to midterm outcomes have been promising, there remain concerns regarding long-term outcomes, with potentially high rates of late recurrence, revision, and secondary osteoarthritis.

Advances in Oncologic Shoulder Girdle Resection and Reconstruction.

The bony shoulder girdle consists of the clavicle, humerus, and scapula, which work synergistically to form a complex articulation that is essential for use of the upper extremity. The shoulder girdle is the most common location for primary and secondary bone tumors in the upper extremity, and following resection of these tumors, reconstruction of the upper extremity is challenging. Compared with those in the lower extremity, reconstructive techniques in the upper extremity have historically been unreliable and fraught with complications and poor functional outcomes. Newer reconstructive techniques using reverse total shoulder arthroplasty and functional muscle flaps have shown promise to improve outcomes while reducing complications for proximal humerus reconstructions. Despite these advancements, reconstruction following scapulectomy remains challenging and is still associated with more frequent complications and compromised function.

How to avoid baseplate failure: the effect of compression and reverse shoulder arthroplasty baseplate design on implant stability.

BACKGROUND: Failure to achieve fixation of the glenoid baseplate will lead to clinical failure. The fixation of the baseplate to the scapula must be able to withstand sufficient shear forces to allow bony ingrowth. The importance of compression to neutralize the forces at the baseplate-bone interface has been assumed to be critical in limiting excessive micromotion. The purpose of this study is to determine the effect of compression on implant stability with different baseplate designs. METHODS: Various baseplate designs (1-piece monolithic central screw [1P], 2-piece locking central screw [2PL], and 2-piece nonlocking center screw [2PNL]) were investigated at 3 different compressive forces (high [810 N], medium [640 N], and low [530 N]). Synthetic bone cylinders were instrumented, and peripheral screws were used in all models. The combination of 1 locking and 3 nonlocking peripheral screw fixation was selected as worst-case scenario. Dynamic testing protocol followed the ASTM F2028-17 standard. The baseplate micromotion at high compression was compared to low compression. Additionally, the baseplate micromotion for each design was compared at baseline (first 50 cycles) and at 10,000 cycles for the 3 different compressive forces where motion above 150 µm was defined as failure. RESULTS: Baseplate micromotion was found to negatively correlate with compression (rpb = -0.83, P < .0001). At baseline, all baseplate designs were considered stable, regardless of compression. With high compression, average micromotion at the glenoid baseplate-bone interface remained below the 150-µm threshold for all baseplate designs at 10,000 cycles (1P: 50 ± 10 µm; 2PL: 78 ± 32 µm; 2PNL: 79 ± 8 µm; P = .060). With medium compression, average micromotion at 10,000 cycles for all 3 designs remained below the 150-µm threshold (1P: 88 ± 22 µm; 2PL: 132 ± 26 µm; 2PNL: 107 ± 39 µm). The 2PL design had the highest amount of micromotion (P = .013). With low compression, both 2-piece designs had an average micromotion above the 150-µm threshold whereas the 1-piece design did not (1P: 133 ± 35 µm; 2PL: 183 ± 21 µm; 2PNL: 166 ± 39 µm). The 2PL design had significantly higher micromotion when compared to 1P design (P = .041). DISCUSSION: The stability of a central screw baseplate correlates with the amount of compression obtained and is affected by implant design. For the same amount of compression, more micromotion is observed in a 2-piece design than a 1-piece design.

Inlay structure can improve bone graft stability in the Bristow procedure.

BACKGROUND: Compared with the Latarjet procedure, the Bristow procedure has a lower screw-related complication rate but poor bone healing. A modified Inlay Bristow procedure has been reported to significantly improve the bone healing rate, but the biomechanical mechanism is unclear. The aim of this study was to evaluate the biomechanical stability of the bone graft between a modified Inlay Bristow procedure and the classic Bristow procedure. METHODS: Sixteen left scapula models (Sawbones, Composite Scapula, and fourth generation) were randomly divided into 2 groups (8:8). The bone graft in the first group was fixed with a 3.5 mm screw using the Inlay structure. The bone graft in the second group was fixed with a 3.5 mm screw via the traditional method. The maximum cyclic displacement, ultimate failure load and stiffness were evaluated biomechanically. The failure type was recorded for each model. RESULTS: Cyclic loading tests demonstrated that the maximum cyclic displacement of the Inlay procedure was significantly smaller (P = .001) than that of the classic procedure. The Inlay Bristow technique resulted in a significantly higher (P = .024) ultimate failure load than the classic Bristow technique. The stiffness of the classic group was 19.17 ± 4.01 N/mm and that of the inlay group was 22.34 ± 5.35 N/mm (P = .232). Failure was mainly due to bone graft fractures through the drill hole or glenoid bone fractures. CONCLUSION: Inlay Bristow fixation of the bone graft in a Sawbones model provides significantly stronger fixation and better time point zero stability than classic Bristow fixation, suggesting a higher likelihood of graft union.

Revision of failed reverse total shoulder arthroplasty with reverse: short-term clinical outcomes.

BACKGROUND: The prevalence of failed reverse total shoulder arthroplasty (rTSA) is increasing. This can often present a challenging clinical situation with substantial bone loss and limited reconstruction options. This study reports a single tertiary referral center's experience with revision of failed rTSA managed with revision rTSA of bone-interfacing components. METHODS: After institutional review board approval, all revision shoulder arthroplasty cases performed at a single institution between 2012 and 2020 were reviewed. Cases in which rTSA was revised to a new rTSA construct with revision of at least 1 bone-interfacing implant (humeral stem and/or baseplate) with a minimum 2-year follow-up were identified. Characteristics of revision cases-including indications, bony stock, revised components, and use of bone graft-were collected. All patients were contacted for patient-reported outcome measures at a minimum of 2 years after surgery. In addition, the incidence and indication for any reoperation after revision were determined. RESULTS: Thirty-three patients with an average age of 66 years (range: 46-82 years), with 19 (58%) being female, met the inclusion criteria and had a mean follow-up of 4.2 years (range: 2-8 years). The most common indication for revision rTSA included humeral component loosening (33%; 11/33), baseplate loosening (27%; 9/33), and instability (21%; 7/33). Prerevision infectious workup demonstrated no cases of periprosthetic shoulder infection. Thirteen cases had massive bone loss-5 treated with humeral allograft prosthetic composite, 5 with glenoid bone grafting, and 3 with custom glenoid implant. In total, 10 of 33 cases (30%) required reoperation at a mean of 13 months (range: 1-44 months) for instability (4), humeral loosening (2), infection (1), baseplate loosening (1), or periprosthetic fracture (1). The reoperation rate for patients with revised baseplates only, humerus only, or combined was 23% (3/13), 28% (5/18), and 27% (3/11), respectively. Overall, the visual analog scale pain score improved from 6.5 preoperatively to 2.0 (P < .001), and the American Shoulder and Elbow Surgeons score improved from 30.7 to 67.5 (P < .001). However, the postoperative Single Assessment Numeric Evaluation score averaged only 51.2% (range: 2-100%). CONCLUSION: This study demonstrates that failed rTSA can be salvaged with a revision rTSA. However, patient expectations for functional improvements should be tempered, and a high reoperation rate should be expected.

Stability of novel cow-hitch suture button coracoid bone graft fixation in Latarjet procedures: a biomechanical study.

BACKGROUND: The Latarjet procedure is widely used to address anterior shoulder instability, especially in case of glenoid bone loss. Recently, cortical suture button fixation for coracoid transfer has been used to mitigate complications seen with screw placement. The aim of this biomechanical study was to evaluate the stability of a novel and cost-effective cow-hitch suture button technique, designed to be performed through a standard open deltopectoral approach, and compare this to a well-established double suture button technique. MATERIALS AND METHODS: We randomly assigned 12 fresh frozen cadaveric shoulders to undergo the Latarjet procedure with either 4 suture button (S&N EndoButton) fixations (SB group; n = 6, age 72 ± 9.8 years) or cow-hitch suture button technique using a 1.7-mm FiberTape looped sequentially in 2 suture buttons (Arthrex Pectoralis Button) placed from anterior on the posterior glenoid (CH-SB group; n = 6, age 73 ± 9.3 years). After fixation, all shoulders underwent biomechanical testing with direct loading on the graft via a material testing system. Cyclic loading was performed for 100 cycles (10-100 N) to determine axial displacement with time; each graft was then monotonically loaded to failure. RESULTS: The maximum cyclic displacement was 4.3 ± 1.6 mm for the cow-hitch suture button technique and 5.0 ± 1.7 mm for the standard double suture button technique (P = .46). Ultimate load to failure and stiffness were, respectively, 190 ± 82 N and 221 ± 124 N/mm for the CH-SB technique and 172 ± 48 N and 173 ± 34 N/mm for the standard double SB technique (P = .66 and .43). The most common failure mode was suture cut-through at the anteroinferior aspect of the glenoid for both fixation groups. CONCLUSIONS: The cow-hitch suture button technique resulted in a similar elongation, stiffness, and failure load compared to an established double suture button technique. Therefore, this cost-effective fixation may be an alternative, eligible for open approaches, to the established double suture button techniques.

Primary bone graft stability after Latarjet surgery: biomechanical evaluation of a fixation technique with metal-free all-suture cerclage vs. cortical screws.

BACKGROUND: To reduce hardware-related complications in coracoid graft fixation to the anterior aspect of the glenoid, a metal-free Latarjet technique was recently introduced. The aim of this study was to compare the primary stability of a classic Latarjet procedure with 2 metal screws to a novel metal-free, all-suture cerclage method. It is hypothesized that fixation of the coracoid graft with 2 malleolar screws will provide higher primary stability compared with an all-suture cerclage technique. METHODS: This biomechanical in vitro study was conducted on 12 fresh-frozen cadaveric shoulders (6 matched pairs) with a mean donor age of 80 years (range, 67-89 years). Coracoid graft fixation was performed using a recently introduced all-suture cerclage technique (group A) or a classic Latarjet technique with two 4.5-mm malleolar screws (group B). The conjoint tendon was loaded with a static force of 10 N to simulate the sling effect. Graft loading with a probe head consisted of 6 ascending load levels (10-50 N, 10-100 N, 10-150 N, 10-200 N, 10-250 N, and 10-300 N) with 100 cycles each at 1 Hz. Relative motion of the bone graft to the glenoid was measured using an optic 3-dimensional system. RESULTS: While loading the conjoint tendon with 10 N, no difference in mean displacement of the bone-graft was found between both groups (P = .144). During cyclic loading, a significant difference in relative displacement for both groups was already detected in load level 1 (group A: 2398.8 µm vs. group B: 125.7 µm; P = .024), and this trend continued with the following load levels (P < .05). DISCUSSION AND CONCLUSION: The study demonstrated that the innovative metal-free, all-suture cerclage fixation technique results in higher micromotion than the classic coracoid graft fixation with 2 malleolar screws. According to the present biomechanical investigation, shoulders treated with a metal-free all-suture cerclage technique might need adapted rehabilitation protocols to protect the construct and allow for graft healing.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND: Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts. METHODS: A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup. RESULTS: The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023). DISCUSSION: Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Preoperative patient factors that predict achieving the minimal clinically important difference following arthroscopic treatment of snapping scapula syndrome.

BACKGROUND: The aim of this study was to define the minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) after arthroscopic treatment of snapping scapula syndrome (SSS) using a distribution-based method, and to identify demographic, clinical, and intraoperative factors significantly associated with the achievement of MCID. It was hypothesized that subjective satisfaction scores after the procedure would be strongly associated with the achievement of MCID thresholds for the PROs and that pain, preoperative response to injection, and a scapulectomy in addition to bursal resection would be predictive of clinically relevant improvement. METHODS: Patients who underwent arthroscopic treatment of SSS between October 2005 and September 2020 with a minimum of 2-year short-term postoperative follow-up were enrolled in this retrospective single-center study. The MCID was calculated using a distribution-based approach for the following PROs: 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain "today" and "at worst." The association between achievement of the MCID and postoperative subjective satisfaction was investigated, and factors associated with achievement of MCID were determined using bivariate analysis. RESULTS: Of a total of 190 patients assessed for eligibility, 77 patients (38.1 ± 14.3 years; 36 females) were included. Within the study population, statistically significant improvements in postoperative SF-12 physical component summary (PCS) (P < .001) and mental component summary (MCS) (P < 0.034), ASES (P < .001), QuickDASH (P < .001), SANE (P < .001), and VAS pain (P < .001) scores were observed at the minimum 2-year follow-up. The calculated MCID threshold values based on the study population were 5.0 for SF-12 PCS, 5.8 for SF-12 MCS, 11.3 for ASES, -10.5 for QuickDASH, 14.7 for SANE, 1.5 for VAS pain, and 1.7 for VAS pain at worst. Reaching the MCID was strongly associated with postoperative satisfaction (rated on a scale of 1-10). Across the PROs, younger age, favorable preoperative response to injection, partial scapuloplasty or scapulectomy, no prior surgery, and pain and function at baseline were significantly associated with attaining MCID. CONCLUSIONS: Patients who underwent arthroscopic treatment for SSS experienced clinically significant improvements in functional scores, pain, and quality of life. This study demonstrated predictive roles for certain patient-specific factors and diagnostic variables for achieving MCID in PROs, which may help surgeons preoperatively assess the probability of success and manage patient expectations.

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.

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.

Premorbid glenoid anatomy reconstruction from contralateral shoulder 3-dimensional measurements: a computed tomography scan analysis of 260 shoulders.

BACKGROUND: Total shoulder arthroplasty (TSA) aims to reconstruct the premorbid anatomy of a pathologic shoulder. A healthy contralateral shoulder could be useful as a template in planning TSA. The symmetry between the left and right shoulders in healthy patients remains to be proved. The purpose of this study was to compare the 3-dimensional anatomy of the glenoid between sides in a healthy population. METHODS: A multinational computed tomography scan database was retrospectively reviewed for all healthy bilateral shoulders in patients aged between 18 and 50 years. One hundred thirty pairs of healthy shoulder computed tomography scans were analyzed, and glenoid version, inclination, width, and height, as well as glenoid lateral offset and scapula lateral offset, were measured. All anatomic measures were computed with Blueprint, validated 3-dimensional planning software. The intraclass correlation coefficient was determined for each measure between left and right shoulders. The minimal detectable change (MDC) was calculated using the following formula: MDC=2×1.96×Standarderrorofmeasurement. RESULTS: The comparison between 130 pairs of healthy scapulae showed statistically significant differences in absolute values between right and left glenoid version (-5.3° vs. -4.6°, P < .01), inclination (8.4° vs. 9.3°, P < .01), and width (25.6 mm vs. 25.4 mm, P < .01), as well as scapula offset (105.8 mm vs. 106.2 mm, P < .01). Glenoid height was comparable between right and left shoulders (33.3 mm vs. 33.3 mm, P = .9). The differences between the means were always inferior to the MDC regarding glenoid version, inclination, height, and width, as well as scapula offset. Very strong intraclass correlation coefficients between the left and right shoulders were found for all evaluated paired measures. CONCLUSION: Healthy contralateral scapulae are highly reliable to predict inclination, height, width, and scapula offset and are reliable to predict version of a given scapula. Paired right and left scapulae were not statistically symmetrical regarding mean glenoid version, inclination, and width, as well as scapula offset. Nevertheless, the reported differences were not higher than the MDC for this cohort, confirming that healthy contralateral shoulders can be a useful template in TSA preoperative planning.

Acromion fractures after reverse shoulder arthroplasty occur in predictable clusters.

BACKGROUND: Acromion and scapular spine fractures (ASFs) following reverse total shoulder arthroplasty (RSA) have been reported at a rate of 3.9%. The location of the fracture has been shown to be an important factor in determining the outcomes of nonoperative treatment, with medial fractures having worse outcomes than lateral fractures. As the debate between operative and nonoperative treatment continues, a more precise understanding of the location of the fracture is necessary for effective management. The purpose of this study was to use 3-dimensional computed tomography (CT) reconstruction to characterize the exact location of ASFs after RSA. METHODS: A retrospective review of 2 separate institutional shoulder and elbow repositories was performed. Patients with post-RSA ASFs documented by post-fracture CT scans were included. The query identified 48 patients who sustained postoperative ASFs after RSA between July 2008 and September 2021. CT scans of patients with ASFs were segmented using Mimics software. Eight patients were excluded because of poor image quality. Each bone model was manipulated using 3-Matic Medical software to align the individual scapula with an idealized bone model to create a view of scapular fracture locations on a normalized bone model. This model was used to classify the fractures using the modified Levy classification. RESULTS: The study cohort consisted of 40 patients with a diagnosis of postoperative ASF after RSA. The median age at the time of surgery was 76 years (interquartile range, 73-79 years). The cohort comprised 32 women (80%) and 8 men (20%), with a median body mass index of 27.8. Only 10 patients (25%) had a previous diagnosis of osteoporosis and 6 (13%) had a diagnosis of inflammatory arthritis; 53% of patients underwent RSA owing to rotator cuff tear arthropathy. The distribution of fracture locations was similar within the cohort. However, lateral fractures were slightly more prevalent. The most common fracture location was the type I zone, with 12 fracture lines (29%). There were 11 fracture lines (26%) in the type IIa zone, 10 (23%) in the type IIb zone, 0 in the type IIc zone, and 9 (21%) in the type III zone. CONCLUSION: ASFs after RSA occur in 4 predictable clusters. No fractures appeared to distinctly cluster in the type IIc zone, which may not represent a true fracture zone. Understanding the distribution of these fractures will help to enable the future design of implants and devices to stabilize the fractures that require fixation.

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.

Intraoperative navigation system use increases accuracy of glenoid component inclination but not functional outcomes in reverse total shoulder arthroplasty: a prospective comparative study.

BACKGROUND: While the use of computer-assisted navigation systems in prosthetic implantation is steadily increasing, its utility in reverse shoulder arthroplasty (RSA) remains unclear. The purpose of this study was to evaluate the clinical utility of an intraoperative navigation system in patients undergoing RSA. MATERIALS AND METHODS: Patients undergoing navigated or standard RSA at a single institution between September 2020 and December 2021 were prospectively enrolled. Exclusion criteria included noncompliance with study procedures or humeral fracture. Outcome measures included postoperative version and inclination, range of motion (ROM), complications, and patient-reported outcome measurements (PROMs: American Shoulder and Elbow Surgeons score [ASES], Disabilities of the Arm, Shoulder, and Hand score [DASH], Simple Shoulder Test [SST], and Visual Analog Scale [VAS]) at final follow-up. RESULTS: The final cohort contained 16 patients with navigation and 17 with standard RSA at a mean follow-up of 16 months (range 12-18 months). Average age was 72 years (range 66-80 years), 8 male (24%) and 25 female (76%). There were no differences in demographics between groups (p > 0.05). At baseline, the navigated group had a greater proportion of Walch B1 and B2 glenoids (p = 0.04). There were no differences between groups regarding baseplate type and native/planned/postoperative glenoid version and inclination. In both groups, planned and postoperative versions were not significantly different (p = 0.76). Patients who did not have navigation demonstrated significant differences between planned and postoperative inclination (p = 0.04), while those with navigation did not (p = 0.09). PROM scores did not differ between groups at final follow-up for SST (p = 0.64), DASH (p = 0.38), ASES (p = 0.77), or VAS (p = 0.1). No difference in final ROM was found between groups (p > 0.05). Over 50% of all screws in both groups were positioned outside the second cortex (p = 0.37), albeit with no complications. CONCLUSIONS: There were no statistically significant differences in ROM, PROMs, and satisfaction between patients receiving computer-navigated and standard RSA at a short-term follow-up. Despite more severe preoperative glenoid erosion in the navigated group, all patients were able to achieve an appropriate neutral axis postoperatively. The cost effectiveness and appropriate use of computer-navigated RSA warrant specific investigation in future studies. LEVEL OF EVIDENCE: II, prospective cohort study. TRIAL REGISTRATION: 9/1/2020 to 12/31/2021.

Risk of suprascapular nerve injury in open Trillat procedure: an anatomical study.

PURPOSE: The open Trillat Procedure described to treat recurrent shoulder instability, has a renewed interest with the advent of arthroscopy. The suprascapular nerve (SSN) is theoretically at risk during the drilling of the scapula near the spinoglenoid notch. The purpose of this study was to assess the relationship between the screw securing the coracoid transfer and the SSN during open Trillat Procedure and define a safe zone for the SSN. METHODS: In this anatomical study, an open Trillat Procedure was performed on ten shoulders specimens. The coracoid was fixed by a screw after partial osteotomy and antero-posterior drilling of the scapular neck. The SSN was dissected with identification of the screw. We measured the distances SSN-screw (distance 1) and SSN-glenoid rim (distance 2). In axial plane, we measured the angles between the glenoid plane and the screw (α angle) and between the glenoid plane and the SSN (ß angle). RESULTS: The mean distance SSN-screw was 8.8 mm +/-5.4 (0-15). Mean α angle was 11°+/-2.4 (8-15). Mean ß angle was 22°+/-6.7 (12-30). No macroscopic lesion of the SSN was recorded but in 20% (2 cases), the screw was in contact with the nerve. In both cases, the ß angle was measured at 12°. CONCLUSION: During the open Trillat Procedure, the SSN can be injured due to its anatomical location. Placement of the screw should be within 10° of the glenoid plane to minimize the risk of SSN injury and could require the use of a specific guide or arthroscopic-assisted surgery.

Ipsilateral fractures of the acromion and coracoid processes of the scapula.

A fracture of the acromion and coracoid processes of scapula is rarely seen in the outpatient clinic, due to the acromion's anatomical position and shape, as well as the strong ligaments and muscles that are attached to it. These fractures are caused by either direct or indirect high-energy trauma injuries to the shoulder joint, leading to severe pain and a grossly restricted range of motion. Several acromial classifications were reported, but this type of longitudinal plane fracture of the acromion process in our case is yet to be described in the current literature. We present a rare combination of the coracoid process and unstable acromion bony projection fractures that have not previously been noted for this type of fracture. The closest to this is Kuhn's type III classification. A 51-year-old male presented to our emergency department complaining of the right shoulder pain and difficulty raising his arm following a 2-wheeler accident. The patient was managed by open reduction and internal fixation with 3 cannulated cancellous screws fixation and progressed well with no postoperative complications. He was asymptomatic postoperatively and regained full range of motion after 4 months.