Epileptic patients with shoulder anterior instability.

Chronic epilepsy may cause important bipolar bony lesions. We aim to compare the specific pathoanatomic metrics of the bony lesions in chronic shoulder anterior instability that occur in the epileptic population vs non-epileptic population. METHODS: From 2006 to 2020, we included epileptic and non-epileptic patients with anterior recurrent shoulder instability. We randomly adjusted the patients of the two groups according to the sex, age and type of management. We included 50 patients. For each included patient, we performed an in-depth CT-scan analysis and comparison of the glenoid bone loss: PICO method using the best-fit circle; and the Hill-Sachs lesion: the depth and width were given as a percentage of the humeral head diameter on an axial view. We also evaluated the engaging character of the involved lesion using the On-track/Off-track analysis. Those characteristics were compared between the two groups. RESULTS: We found a glenoid bone loss in 32 patients. Glenoid bone loss was not significantly greater in patients with epilepsy (p=0.052). A Hill-Sachs lesion was found in 42 patients (22 in epileptic group and 20 in non-epileptic group). Hill-Sachs lesions were significantly deeper and larger in the epileptic group. (depth: 22% vs 9%, p<0.001; width: 43% vs 28%, p=0.003). In the epileptic group 90% of the bone lesions were OFF-track versus 30% in the non-epileptic group. Thus, the epileptic patients presented more engaging bony lesions than non-epileptic patients (p=0.001) (OR=23). CONCLUSIONS: In a population of epileptic patients, Hill-Sachs lesions are larger and deeper than in patients with non- epileptic shoulder instability. By contrast, there is no significant difference regarding the characteristics of the glenoid bone loss if present. This implies that bone lesions in instable shoulders of epileptic patients need at least a bony stabilization procedure on the humeral side in the majority of cases.

Long term (Minimum 10 Years) Survival and Outcomes of Pyrocarbon Interposition Shoulder Arthroplasty.

BACKGROUND: There is major controversies surrounding the use and longevity of Pyrocarbon Interposition Shoulder Arthroplasty (PISA). The objective of this study was to investigate the long-term survival and outcomes (minimum 10-year) following PISA for osteoarthritis (OA) in young /active patients. METHODS: This was a retrospective review of prospectively collected data of patients who underwent PISA (InSpyre, Tornier-Stryker, USA) for OA between 2009 and 2012. Arthroplasty survival was known for 71 patients followed longitudinally for a minimum of 10 years. The clinical and radiological outcomes were assessed in 62 patients (62 shoulders) reviewed with radiographs. The mean age at surgery was 60 years (range, 23-72 years) and 31 shoulders (50%) underwent prior surgery before PISA. The diagnosis was primary osteoarthritis (POA=29), post-traumatic osteoarthritis (PTOA=23), post-instability osterarthritis (PIOA=10). Clinical failure was defined as repeat surgical intervention involving prosthesis revision. Clinical outcomes were assessed with Constant score (CS) and Subjective shoulder Value (SSV). The mean duration of follow-up was 11 ± 0.6 years (range, 10 to 14 years). RESULTS: Overall, the survival rate was 90% (95% CI: 82.8-96.8) at 5 years and 87% (95% CI: 79-94.8) at 10 years follow-up. Survival was 100% in PTOA (type 1 fracture sequelae) and in PIOA as well as 95% in primary OA with type-A glenoid. Revision surgery was significantly higher in biconcave (type-B2) glenoid (44%) compared to concentric (type-A) glenoid (2%), respectively (p=0.002). Among the 7 patients who were revised to RSA, 5 had painful glenoid erosion and 2 had bipolar (glenoid and humeral) erosion with thinning and finally fracture of the greater tuberosity (GT). Two shoulders with glenohumeral erosion were associated with secondary rotator cuff tears (one supraspinatus and one subscapularis tear). The mean time to revision and revision was 4 ± 1.7 years. Glenoid wear was more often superior (81%) than central (19%), p<0.001. For those shoulders not revised, the mean CS and SSV significantly increased from 39 ±14 to 70 ±14 points and 34% ±15 to 75% ±17, respectively (p<0.001). CONCLUSION: PISA is an efficient and durable surgical procedure for the treatment of young/active patients with post-traumatic OA, post-instability OA, and primary OA with concentric (type A) glenoid erosion, but not for those with biconcave (type B2) glenoid. Biconcave (type B2) glenoid and subscapularis tear or insufficiency are risk factors for failure and revision.

Restoration of internal rotation after reverse shoulder arthroplasty may vary depending on etiology in patients younger than 60 ​years of age: a multicenter retrospective study.

BACKGROUND: Reverse shoulder arthroplasty (RSA) offers promising functional outcomes for young patients, yet challenges persist in restoring internal rotation (IR). This study aimed to assess the restoration of IR after RSA in patients younger than 60 years of age and analyze the factors affecting IR recovery. METHODS: A retrospective multicenter study was conducted, examining the functional outcome of patients who underwent RSA, with a minimum follow-up period of 2 years. Two subgroups of patients who underwent primary RSA were analyzed separately with respect to active internal rotation with the elbow at the side (AIR1): "difficult AIR1" and "easy AIR1." RESULTS: The study included 136 patients (overall series) with a mean age of 51.6 years. The overall series showed statistically significant improvement in active range of motion (RoM), pain, and Constant scores, especially with active IR (p â€‹< â€‹0.01). According to etiology, statistically significant improvement (p â€‹< â€‹0.05) in active IR was observed for fracture sequelae, primary osteoarthritis, and rheumatoid arthritis, whereas no statistically significant improvement in IR was observed for tumor, revision, and cuff-tear arthropathy (p â€‹> â€‹0.05). In subgroup analysis, patients with easy AIR1 displayed a statistically significant lower body mass index and better Constant score mobility, as well as improved motion in forward elevation and active IR (p â€‹< â€‹0.05). No statistically significant associations were found between improved IR and prosthetic design or subscapularis repair. Scapular notch, lysis of the graft, and teres minor atrophy were significantly associated with better active IR (p â€‹< â€‹0.05). CONCLUSION: RSA improves active RoM, pain, and functional outcomes in patients aged under 60. However, the degree of improvement in IR may vary depending on several factors and the underlying etiologies. These insights are crucial for patient selection and counseling, guiding RSA optimization efforts. LEVEL OF EVIDENCE: IV.

The glenoid track concept is insufficient to predict Bankart failures: a computed tomography scan study.

Background: The glenoid track concept identifies patients with "off-track" (engaging) Hill-Sachs lesions (HSLs) as poor candidates for arthroscopic Bankart repair (ABR) due to the high risk of shoulder instability recurrence. Purpose: To retrospectively calculate the glenoid track index, using preoperative computed tomography (CT) scans, in a cohort of patients with failed ABR. We hypothesized that all patients with a failed ABR would have engaging ("off-track") HSLs on preoperative CT scan. Type of Study: CT scan study. Methods: Preoperative CT scan of 45 patients, seen in our facility for failed ABR, was used to retrospectively calculate the glenoid track index. The risk of recurrence was also calculated for each patient using Instability Severity Index Score (ISI-Score) and Glenoid Track Instability Management Score (GTIMS). There were 37 failed isolated ABRs and 8 associated HS remplissage. The mean t age at surgery was 24 years (range, 15-52) and instability recurred at a mean of 29 months postoperative (range, 3-167). Results: Preoperative CT scan imaging identified "off-track" bony lesions in 85% of patients (38/45) and "on-track" lesions in 15% (7/45). No significant differences were noted between the 2 groups (off-track vs. on-track) regarding patient age, hyperlaxity, sports participation, size of HS lesion, or ISI-Score. The mean glenoid bone loss was 15.7% (range, 4-36%) with mean HS width was greater than 20 mm in 66% of CT scans. The preoperative ISI-Score was predictive of failures (>3 points in all patients) with no difference between on-track and off-track patients (6.3 ± 1.7 vs. 6.6 ± 1.7, P = .453). By contrast, the GTIMS did not predict failures as there was a significant difference between GTIMS for on-track and off-track patients (2.1 ± 1.3 vs. 6.6 ± 1.7). Conclusions: The glenoid track concept alone is insufficient to predict Bankart failures: in the present series of failed ABR, 15% of shoulders had "on-track" (non-engaging) lesions on preoperative CT scan. In patients, with "on-track" bony lesions, the ISI-Score is a useful predictive tool to detect patients at risk of failure, while the GTIMS is not.

Hallucination Rates and Reference Accuracy of ChatGPT and Bard for Systematic Reviews: Comparative Analysis.

BACKGROUND: Large language models (LLMs) have raised both interest and concern in the academic community. They offer the potential for automating literature search and synthesis for systematic reviews but raise concerns regarding their reliability, as the tendency to generate unsupported (hallucinated) content persist. OBJECTIVE: The aim of the study is to assess the performance of LLMs such as ChatGPT and Bard (subsequently rebranded Gemini) to produce references in the context of scientific writing. METHODS: The performance of ChatGPT and Bard in replicating the results of human-conducted systematic reviews was assessed. Using systematic reviews pertaining to shoulder rotator cuff pathology, these LLMs were tested by providing the same inclusion criteria and comparing the results with original systematic review references, serving as gold standards. The study used 3 key performance metrics: recall, precision, and F1-score, alongside the hallucination rate. Papers were considered "hallucinated" if any 2 of the following information were wrong: title, first author, or year of publication. RESULTS: In total, 11 systematic reviews across 4 fields yielded 33 prompts to LLMs (3 LLMs×11 reviews), with 471 references analyzed. Precision rates for GPT-3.5, GPT-4, and Bard were 9.4% (13/139), 13.4% (16/119), and 0% (0/104) respectively (P<.001). Recall rates were 11.9% (13/109) for GPT-3.5 and 13.7% (15/109) for GPT-4, with Bard failing to retrieve any relevant papers (P<.001). Hallucination rates stood at 39.6% (55/139) for GPT-3.5, 28.6% (34/119) for GPT-4, and 91.4% (95/104) for Bard (P<.001). Further analysis of nonhallucinated papers retrieved by GPT models revealed significant differences in identifying various criteria, such as randomized studies, participant criteria, and intervention criteria. The study also noted the geographical and open-access biases in the papers retrieved by the LLMs. CONCLUSIONS: Given their current performance, it is not recommended for LLMs to be deployed as the primary or exclusive tool for conducting systematic reviews. Any references generated by such models warrant thorough validation by researchers. The high occurrence of hallucinations in LLMs highlights the necessity for refining their training and functionality before confidently using them for rigorous academic purposes.

Comparison of Return to Sports and Competition After the Arthroscopic Bristow-Latarjet Procedure Versus Arthroscopic Bankart Repair in Adolescents With Recurrent Anterior Shoulder Instability.

BACKGROUND: The use of isolated soft tissue repair versus bone block stabilization for the treatment of recurrent anterior shoulder instability in adolescents has no scientific evidence. PURPOSE: To compare the clinical outcomes of adolescent patients who underwent isolated arthroscopic Bankart (iB) repair with those who underwent the arthroscopic Bristow-Latarjet procedure in addition to Bankart (BLB) repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 60 shoulders in adolescents (aged 13-18 years) were reviewed with a minimum 2 years' follow-up: iB repair (n = 36) and arthroscopic Bankart repair with an additional Bristow-Latarjet procedure (BLB; n = 24). The characteristics of the patients in each group in terms of age at the first instability episode, age at surgery, hyperlaxity, participation in at-risk sports, and Instability Severity Index Score were comparable. The mean follow-up was longer in the iB group (7.7 vs 4.1 years, respectively), whereas the rates of patients engaged in competition and those with glenoid lesions were higher in the BLB group. The primary outcome measures were failure, defined as the recurrence of instability (clinical dislocation or subluxation), and return to sports. The mean follow-up was 6.2 years (range, 2-16 years). RESULTS: At the last follow-up, the rate of recurrence was significantly higher in the iB group, with 22% (8/36) failures, than in the BLB group, with 8% (2/24) instability recurrences (P < .05). The rate of return to sports at the same level was significantly higher after the BLB repair than after iB repair (79% vs 47%, respectively; P < .001). No statistical difference was found in patient-reported outcome scores between treatment groups (P > .05). Although failures occurred early after the BLB repair, 88% of failures after iB repair occurred after 2 years. On multivariate analysis, adolescents in the iB group with >3 episodes of preoperative dislocation and shoulder hyperlaxity (external rotation >90°) had a 60% recurrence rate (P < .005). CONCLUSION: Adolescent patients undergoing the BLB repair had a lower rate of recurrent instability and higher rates of return to sports and competition than those undergoing iB repair. Patients with shoulder hyperlaxity (external rotation >90°) and >3 dislocations had an unacceptable failure rate of 60% after iB repair.

Intramedullary nailing of humeral shaft fractures: percutaneous nailing in the lateral position through the Neviaser approach is a reliable technique.

BACKGROUND: Displaced humeral shaft fractures are frequently treated by osteosynthesis in the active patient. We aimed to evaluate the results of intramedullary nailing (IMN) in the lateral position with the Neviaser approach and to compare them with those from IMN nailing in the standard position and conventional approach. METHODS: In the retrospectively evaluated, single-center study, we compared 20 cases of long IMN for fractures of the proximal or middle third of the humerus shaft (Multilock; Synthes Laboratory) in the lateral position with the percutaneous Neviaser approach with 52 cases of IMN in the standard position. The mean age of patients was 62 ± 21 years. Clinical outcomes were analyzed: Constant score, subjective shoulder evaluation score and range of motion. Radiographically, entry point at the proximal part of the humerus, the healing rate and the possible association between the critical shoulder angle (CSA) and the correct positioning of the nail were assessed. RESULTS: With a mean follow-up of 26 ± 2 months, the healing rate was 89% (64/72) in the overall series, (eight patients in non-union), with no difference between the two groups. The overall mean active anterior elevation (AAE) was 125 ± 22°, mean external rotation (ER1) was 35 ± 17°, and mean internal rotation (IR) was at L3. The mean Constant score was 58 ± 23 and subjective shoulder evaluation score 73 ± 12%. ranges of motion were better in the lateral than standard position group (AAE 133 ± 17 vs. 122 ± 23, P = .03; ER1 47 ± 13 vs. 30 ± 16, P < .001; IR T12 vs. L5, P = .02). The nail was less often protruding in the lateral than standard position group (1/20 [5%] vs. 20/52 [38.5%], P = .002). The nail was better positioned from the anteroposterior view (nail centered: 16/20 [75%] vs. 26/52 [50%], P = .047) and lateral view (nail centered: 18/20 [90%] vs. 34/52 [65.4%], P = .02) in the lateral than standard position group. We found no association between nail position, type of approach and CSA. CONCLUSIONS: In the short-term follow-up, osteosynthesis of humeral shaft fractures by using long IMN in the lateral position with the Neviaser approach is a reliable technique. The positioning of the nail, in particular its entry point, and the clinical results were better with the lateral position and Neviaser approach than with the standard position and conventional approach. Further studies with a larger number of patients, assessment of the learning curve, and analysis of the impact of this technique on comorbidities (unchanged cerebral perfusion) are needed to fully validate this technique.

Postoperative Shoulder Function Assessment: Proposing the Concept of "Forgotten Shoulder" Over "Normal Shoulder" as the New Standard in Single Assessment Numerical Evaluation.

A major limitation of Patient-Reported Outcomes Measures (PROMs) postoperatively is the ceiling effect, where patients report the maximum score, making it difficult to differentiate between different conditions. Our findings regarding the SSV-Sport reveal a significant ceiling effect post-surgery, indicating the need for improvements in PROMs, including the Single Assessment Numerical Evaluation (SANE). One of the problems with SANE is scoring a 'normal' joint as the maximum. Patients might tolerate some subtle imperfections in their recovery and still consider their joint 'normal'. Proposing the concept of a 'forgotten' joint into the SANE could be a more accurate assessment tool and c which could diminish the ceiling effect. We suggest a shift from 'normal joint' to 'forgotten joint' as a standard for evaluating postoperative recovery and function in SANE.

Can Pyrocarbon be used as a functional spacer for the treatment of recalcitrant shoulder infections?

Background: The most common treatment approach in periprosthetic joint infection (PJI) and chronic shoulder joint infection (SJI) is a two-stage revision involving interval placement of an antibiotic cement spacer or a resection arthroplasty. Knowing that Pyrocarbon has a smooth surface that prevents pathogen adhesion, the question arises whether it could be used as a temporary or permanent functional spacer? Purpose: The primary objective of the present study was to assess the rate of infection eradication after temporary or definitive implantation of Pyrocarbon Interposition Shoulder Arthroplasty (PISA) in patients with recalcitrant PJI or SJI. Our secondary objective was to assess mid-term clinical and radiographic outcomes. Methods: Fifteen patients (mean age: 52 ± 19 years) with chronic shoulder infection underwent, after joint débridement, implantation of PISA (InSpyre; Tornier-Stryker, Kalamazoo, MI, USA) with tailored perioperative antibiotics. In 7 cases, PJI occurred after hemiarthroplasty (n = 2), reverse shoulder arthroplasty (n = 2), hemireverse (n = 2), and resurfacing arthroplasty (n = 1). In 8 cases, SJI occurred in the context of failed surgery after fracture sequelae (n = 4), instability (n = 2), and cuff arthropathy (n = 2). Preoperatively, patients had a mean of 3 previous failed surgeries before PISA implantation. Patients were evaluated with clinical, laboratory, and radiographic assessment at a minimum of 2 years after surgery. Results: At a mean follow-up of 55 ± 18 months, no patient experienced reinfection after temporary (3 cases) or definitive (12 cases) PISA implantation. The adjusted Constant score increased from 33% ± 20 preoperatively to 65% ± 28 at last follow-up and SSV from 22% ± 19 to 63% ± 23 (P < .001). Active forward elevation increased from 27° ± 19 to 113° ± 30, external rotation from 7° ± 21 to 25° ± 25, and internal rotation level 3 ± 2 to level 5 ± 2 points (P < . 001). On final radiographs of definitive PISA, complete humeral densification, or a neocortex, formed around the implant in 64% (7/11). Conclusion: Our data suggest that, after washout, débridement and tailored antibiotics, PISA can be used as a temporary or definitive functional spacer for the treatment of recalcitrant shoulder infections and presents the following advantages: (1) PISA does not seem to be a risk for recurrent infection thanks to the antibacterial property of Pyrocarbon; (2) PISA can be used as a temporary or a definitive spacer without causing bone erosion, thanks to the low modulus of elasticity of Pyrocarbon; (3) PISA can be used as a salvage procedure in case of complete glenoid or humeral destruction, thanks to the sphericity of the implant needing no implant anchorage.

Total shoulder arthroplasty for primary glenohumeral osteoarthritis: does posterior humeral subluxation persist after correction of the glenoid version at 5 years minimum?

BACKGROUND: Primary glenohumeral osteoarthritis is associated with both excessive posterior humeral subluxation (PHS) and excessive glenoid retroversion in 40% of cases. These morphometric abnormalities are a particular issue because they may be responsible for a deterioration in long-term clinical and radiologic outcomes. The aim of this study was to perform a computed tomographic (CT) analysis of patients who underwent total shoulder arthroplasty (TSA) for primary osteoarthritis (OA) with B2-, B3-, or C-type glenoids in whom an attempt was made to correct for excessive glenoid retroversion and excessive posterior humeral subluxation intraoperatively. MATERIAL: We performed a retrospective, single-center study including 62 TSA patients with a preoperative PHS of the glenohumeral joint (31 men, 31 women, 70 ± 9 years) between January 2000 and January 2014. Glenoids were classified as B2 (32 cases), B3 (13 cases), or C (17 cases). Glenoid retroversion was corrected by anterior asymmetric reaming. Patients were reviewed for clinical and CT scan assessment with a mean follow-up of 8.3 years (minimum 5 years). At final follow-up, the CT images were reconstructed in the scapular plane. A PHS index >65% defined persistence. RESULTS: The revision-free rate was estimated at 93%. Correlation between PHS and retroversion was moderate preoperatively (ρ = 0.58) and strong at final follow-up (ρ = 0.73). Postoperative CT scans on average showed a surgical correction of PHS compared to preoperatively (79% vs. 65% respectively, P < .05) and retroversion (20° vs. 10° respectively, P < .05). At final follow-up, 25 of 62 patients had a persistence in the 2-dimensional (2D) model and 41 of 62 in the corrected 2D model. Persistence of PHS had no influence on clinical outcomes but did demonstrate a significantly higher glenoid loosening rate (20% vs. 59%, P < .05). CONCLUSION: Correlation between PHS and retroversion was moderate preoperatively and strengthened at long-term follow-up. Anterior asymmetric reaming allowed for a surgical improvement of both PHS and retroversion, but it was not sufficient to maintain a correction over time. Glenoid loosening was more frequent in case of PHS persistence but seemingly without clinical relevance.

Is preoperative 3D planning reliable for predicting postoperative clinical differences in range of motion between two stem designs in reverse shoulder arthroplasty.

BACKGROUND: We aim to predict a clinical difference in the postoperative range of motion (RoM) between 2 reverse shoulder arthroplasty (RSA) stem designs (Inlay-155° and Onlay-145°) using preoperative planning software. We hypothesized that preoperative 3D planning could anticipate the differences in postoperative clinical RoM between 2 humeral stem designs and by keeping the same glenoid implant. METHODS: Thirty-seven patients (14 men and 23 women, 76 ± 7 years) underwent a BIO-RSA (bony increased offset-RSA) with the use of preoperative planning and an intraoperative 3-dimensional-printed patient-specific guide for glenoid component implantation between January 2014 and September 2019 with a minimum follow-up of 2 years. Two types of humeral implants were used: Inlay with a 155° inclination (Inlay-155°) and Onlay with a 145°inclination (Onlay-145°). Glenoid implants remained unchanged. The postoperative RSA angle (inclination of the area in which the glenoid component of the RSA is implanted) and the lateralization shoulder angle were measured to confirm the good positioning of the glenoid implant and the global lateralization on postoperative X-rays. A correlation between simulated and clinical RoM was studied. Simulated and last follow-up active forward flexion (AFE), abduction, and external rotation (ER) were compared between the 2 types of implants. RESULTS: No significant difference in RSA and lateralization shoulder angle was found between planned and postoperative radiological implants' position. Clinical RoM at the last follow-up was always significantly different from simulated preoperative RoM. A low-to-moderate but significant correlation existed for AFE, abduction, and ER (r = 0.45, r = 0.47, and r = 0.57, respectively; P < .01). AFE and abduction were systematically underestimated (126° ± 16° and 95° ± 13° simulated vs. 150° ± 24° and 114° ± 13° postoperatively; P < .001), whereas ER was systematically overestimated (50° ± 19° simulated vs. 36° ± 19° postoperatively; P < .001). Simulated abduction and ER highlighted a significant difference between Inlay-155° and Onlay-145° (12° ± 2°, P = .01, and 23° ± 3°, P < .001), and this was also retrieved clinically at the last follow-up (23° ± 2°, P = .02, and 22° ± 2°, P < .001). CONCLUSIONS: This study is the first to evaluate the clinical relevance of predicted RoM for RSA preoperative planning. Motion that involves the scapulothoracic joint (AFE and abduction) is underestimated, while ER is overestimated. However, preoperative planning provides clinically relevant RoM prediction with a significant correlation between both and brings reliable data when comparing 2 different types of humeral implants (Inlay-155° and Onlay-145°) for abduction and ER. Thus, RoM simulation is a valuable tool to optimize implant selection and choose RSA implants to reach the optimal RoM.

Can we separately measure glenoid vs. humeral lateralization and distalization in reverse shoulder arthroplasty?

BACKGROUND: Lateralization and distalization in reverse shoulder arthroplasty (RSA) can be measured on anteroposterior (AP) radiographs using 2 previously described angles: lateralization shoulder angle (LSA) and distalization shoulder angle (DSA). However, these 2 angles measure global lateralization and distalization but do not allow to differentiate how much lateralization or distalization are attributable to the glenoid and the humerus. We hypothesized that new angles could allow us to separately measure glenoid vs. humeral lateralization and distalization. A more precise understanding of independent glenoid and humeral contributions to lateralization and distalization may be beneficial in subsequent clinical research. METHOD: Retrospective analysis of postoperative AP radiographs of 100 patients who underwent primary RSA for cuff-tear arthropathy, massive cuff tear, or glenohumeral osteoarthritis were analyzed. The new angles that we proposed use well-known bony landmarks (the acromion, glenoid, and humerus) and the most lateral point of the glenosphere, which we termed the "glenoid pivot point" (GPP). For lateralization, we used the GPP to split LSA into 2 new angles: glenoid lateralization angle (GLA) and humeral lateralization angle (HLA). For distalization, we introduced the modified distalization shoulder angle (mDSA) that can also be split into 2 new angles: glenoid distalization angle (GDA) and humeral distalization angle (HDA). Three orthopedic surgeons measured the new angles, using the online tool Tyche. Mean values with overall and individual standard deviations as well as intraclass correlation coefficients (ICCs) were calculated. RESULTS: Because the angles form a triangle, the following equations can be made: LSA = GLA + HLA, and mDSA = GDA + HDA. All angles showed excellent inter- and intraobserver reliability (ICC = 0.92-0.97) with low means of individual standard deviations that indicate a precision of 2° for each angle. CONCLUSION: Use of the most lateral part of the glenosphere (termed glenoid pivot point) allows us to separately measure glenoid vs. humeral lateralization and distalization. The 4 new angles (HLA, GLA, GDA, HDA) described in the present study can be used on true AP radiographs, routinely obtained after shoulder replacement, and the measured angles may be used with all types of reverse prostheses available.

Early morbidity and mortality after one-stage bilateral shoulder arthroplasty.

PURPOSE: One-stage bilateral shoulder arthroplasty has the advantage of requiring a single hospital stay and a single anaesthesia. The topic has been little reported, unlike one stage bilateral hip and knee arthroplasty, which have demonstrated their interest. The aim of the present study was to determine peri- and early post-operative morbidity and mortality after this procedure. The study hypothesis was that peri- and early post-operative morbidity and mortality in one stage bilateral shoulder arthroplasty is low in selected patients and that satisfaction is high. METHODS: A single-centre retrospective study assessed peri- and early post-operative morbidity and mortality in one stage bilateral shoulder arthroplasty. Twenty-one patients, aged < 80 years, with ASA score ≤ 3, were consecutively operated on between 1999 and 2020. Indications comprised primary osteoarthritis, aseptic osteonecrosis, inflammatory arthritis, massive rotator cuff tear, and dislocation fracture, involving both shoulders. RESULTS: There were no early deaths. The complication rate was 10% (4/21 cases). No prosthesis dislocation or sepsis was reported. Mean blood loss was 145 ± 40 cc, mean surgery time 164 ± 63 min, and mean hospital stay five ± four days. Only one patient required postoperative transfusion. Functional results at six months showed significantly improved range of motion and good patient satisfaction. CONCLUSIONS: One-stage bilateral shoulder arthroplasty was feasible in selected patients. Mortality was zero, and morbidity was low. Surgery time was reasonable and required no repositioning. Postoperative home help is indispensable for patient satisfaction during rehabilitation.

Neuromuscular Electrical Stimulation-Enhanced Physical Therapist Intervention for Functional Posterior Shoulder Instability (Type B1): A Multicenter Randomized Controlled Trial.

OBJECTIVE: Functional posterior shoulder instability (FPSI) (type B1) is a severe type of instability, mainly in teenagers and young adults, that leads to loss of function, pain, and stigmatization among peers. An experimental nonsurgical treatment protocol based on neuromuscular electrical stimulation (NMES) showed very promising early results in the treatment of FPSI. The hypothesis of this study was that NMES-enhanced physical therapy leads to better outcomes than physical therapy alone as the current gold standard of treatment in patients with FPSI. METHODS: In this multicenter randomized controlled trial, patients with FPSI were randomly allocated in a 1:1 ratio to either 6 weeks of physical therapy or 6 weeks of physical therapy with simultaneous motion-triggered NMES. Baseline scores as well as outcome scores at 6 weeks, 3 months, 6 months, and 12 months after the intervention were obtained. The predefined primary outcome of this trial was the Western Ontario Shoulder Instability Index (WOSI) at the 3-month time point. RESULTS: Forty-nine patients were randomized and eligible for the trial. The group that received physical therapy with simultaneous motion-triggered NMES showed a significantly better main outcome measurement in terms of the 3-month WOSI score (64% [SD = 16%] vs 51% [SD = 24%]). Two-thirds of the patients from the physical therapist group crossed over to the group that received physical therapy with simultaneous motion-triggered NMES due to dissatisfaction after the 3-month follow-up and showed a significant increase in their WOSI score from 49% [SD = 8%] to 67% [SD = 24%]. The frequency of instability episodes showed a significant improvement in the group that received physical therapy with simultaneous motion-triggered NMES at the 3-month follow-up and beyond, while in the physical therapist group, no significant difference was observed. CONCLUSION: The current study shows that NMES-enhanced physical therapy led to statistically significant and clinically relevant improvement in outcomes in the treatment of FPSI compared to conventional physical therapy alone-from which even patients with prior unsatisfactory results after conventional physical therapy can benefit. IMPACT: Based on the results of this study, NMES-enhanced physical therapy is an effective new treatment option for FPSI, a severe type of shoulder instability. NMES-enhanced physical therapy should be preferred over conventional physical therapy for the treatment of patients with FPSI.

Long-term results of revision rotator cuff repair for failed cuff repair: a minimum 10-year follow-up study.

HYPOTHESIS: Rotator cuff repair remains associated with high retear rates, which range from 13% to 79%. The objective of this study was to evaluate the long-term clinical and structural results after revision rotator cuff repair at a minimum 10-year follow-up. METHODS: We retrospectively studied the records of all patients who underwent revision rotator cuff repair in 3 different institutions between July 2001 and December 2007 with a minimum 10-year follow-up. A total of 54 patients (61% males, mean age 52 ± 6 years old) met the inclusion criteria. Outcome measures included pain (visual analog scale [VAS]), range of motion (ROM), Subjective Shoulder Value (SSV), and the Constant score. Superior migration, osteoarthritis, and acromiohumeral interval (AHI) were assessed on standard radiographs. Fatty infiltration and structural integrity of the repaired tendon were evaluated on magnetic resonance imaging or computed tomographic arthrogram. RESULTS: At a mean 14.1 years (10.4-20.5), range of motion did not progress significantly in elevation and internal rotation between pre- and postoperation (158° [range, 100°-180°] to 164° [range, 60°-180°], P = .33, and L3 [range, sacrum-T12] to T12 [range, buttocks-T7], P = .34, respectively) and decreased in active external rotation from 45° (range, 10°-80°) to 39° (range, 10°-80°) (P = .02). However, VAS, SSV, and Constant score were all significantly improved at last follow-up (P < .001). AHI decreased significantly (P = .002) from 10 mm (7-14 mm) to 8 mm (0-12 mm). Two percent of the supraspinatus/infraspinatus tendons were Sugaya 1, 24% were Sugaya 2, 35% were Sugaya 3, 12% were Sugaya 4, and 27% were Sugaya 5. Goutallier score progressed for all muscles, but this did not reach significance and mean Goutallier remained <2 for all 4 muscles at last follow-up. Hamada score progressed from 0% >grade 2 preoperatively to 6% >grade 2 at last follow-up. CONCLUSION: Revision rotator cuff repair provides significant pain relief and improvement in functional scores at long-term follow-up. The mild progression of fatty infiltration, AHI, and Hamada score suggests that despite high retear rates (39% of stage 4 and 5 in the Sugaya classification), revision repair could possibly have a protective role on the evolution toward cuff tear arthropathy.

Glenoid lateralization and subscapularis repair are independent predictive factors of improved internal rotation after reverse shoulder arthroplasty.

PURPOSE: Reverse shoulder arthroplasty (RSA) has shown improvement in clinical outcomes for various conditions, although some authors expressed concern about the restoration of active internal rotation (AIR). The current study assesses preoperative and intraoperative predictive factors of AIR in patients having a Grammont-style RSA with a minimum five year follow-up. METHODS: We conducted a retrospective multicentric study, including patients operated on with a 155° Grammont-style RSA for cuff-related pathology or primary osteoarthritis with posterior subluxation or an associated cuff tear. Patients were clinically evaluated at a minimum of five year follow-up. Patients with previous surgery or those who had a tendon transfer with the RSA were excluded. Demographic parameters, BMI, preoperative notes, and operative reports were obtained from medical records. AIR was graded according to the constant score system from 0 to 10. RESULTS: A total of 280 shoulders in 269 patients (mean age at surgery, 74.9 ± 5.9 years) met the inclusion criteria and were analyzed. The average follow-up was 8.1 years (range, 5-16 years). Overall, AIR increased from 4.2 (SD 2.5, range 0 to 10) preoperatively to 5.9 (SD 2.6, range 0 to 10) at final follow-up. At the last follow-up, AIR increased in 56% of cases, was unchanged in 26% and decreased in 18%. In 188 shoulders (67%), internal rotation was functional and allowed patients to reach the level of L3 or higher. Multivariable linear regression found the following preoperative clinical factors predictive of worse AIR after RSA: male gender (ß = -1.25 [-2.10; -0.40]; p = 0.0042) and higher values of BMI (ß = -0.085 [-0.17; -0.0065]; p = 0.048). Two surgical factors were associated with better AIR after RSA: glenoid lateralization with BIO-RSA technique (ß = 0.80 [0.043; 1.56]; p = 0.039) and subscapularis repair (ß = 1.16 [0.29; 2.02]; p = 0.0092). CONCLUSIONS: With a mean of eight year follow-up (5 to 16 years), internal rotation was functional (≥ L3 level) in 67% of operated shoulders after Grammont-style RSA; however, two patients out of ten had decreased AIR after surgery. Male patients and those with higher BMIs had worse AIR, with glenoid lateralization (using the BIO-RSA technique) and subscapularis repair, as they are predictive of increased AIR after RSA. LEVEL OF EVIDENCE: Case series, Level IV.

Subjective Shoulder Value for Sport Is a Simple, Reliable, and Valid Score to Assess Shoulder Function in Athletes.

PURPOSE: To validate the subjective shoulder value for sport (SSV-Sport) by measuring its correlation with existing patient-reported outcome measures (PROMs) and defining its psychometric properties. METHODS: Between May 2021 and May 2022, we established 2 patient groups. Group 1 included those (1) aged 18 years or older, who were (2) consulting for the first time for any shoulder condition, (3) regularly participated in sports, and were capable of accessing a questionnaire independently. There were asked to rate their SSV and SSV-Sport at admission and 2 weeks later; they also were asked to answer a questionnaire including other PROMS. Group 2 comprised patients who had (1) undergone shoulder stabilization surgery and had (2) a minimum follow-up period of 6 months. RESULTS: For the shoulder disability patients (group 1, n = 62), there was a strong and significant correlation between SSV-Sport and other PROMs: Quick Disabilities of the Arm, Shoulder and Hand Sport (r = 0.84), Walch-Duplay (r = 0.65), Rowe (r = 0.74), Western Ontario Shoulder Instability (r = 0.78), and SSV (r = 0.75) (P = .0001). The SSV-Sport was reliable at baseline and 2 weeks after (0.91, 95% confidence interval 0.85-0.94), and was responsive to change (P < .001). For the anterior instability patients (group 2, n = 83), SSV was on average 50 points greater than SSV-Sport (29.2 vs 79.4, P < .001) for preoperative values. In both groups, the values of SSV were constantly and significantly higher than the values of SSV-Sport (81.9 ± 21.3 vs 54.8 ± 30.9; P < .001). CONCLUSIONS: The SSV-Sport is an easily administered, reliable, responsive, and valid measure of shoulder function in athletes that is highly correlated with other PROMs. SSV-Sport is better adapted than SSV to quantify pre- and postoperative shoulder deficiency in athletes. LEVEL OF EVIDENCE: Level III, cohort study (diagnosis).

The N-brace trial: Does arm position during immobilisation of proximal humerus fractures influence outcome - A preliminary study.

Background: Traditional initial management of proximal humerus fractures (PHF) involves arm immobilisation in a simple sling (SS) in an internally rotated position. We believe this risks fracture displacement and imbalance of soft tissues, encouraging malunion and stiffness. A neutral-rotation brace (NRB) maintains an arm position which may prevent this, leading to quicker and superior recovery. Methods: We randomised patients with two- to four-part PHF into 4 weeks of immobilisation with either a SS or NRB, independent of surgery. Range of motion (ROM), subjective shoulder value (SSV), DASH, Constant-Murley (CMS) and Oxford Shoulder (OSS) scores were assessed at 6-weeks, 3-months and 1-year post-injury. Results: The SS group included 11 patients vs 9 in the NRB group. At final follow-up, the SS and NRB groups had mean DASH scores of 42 vs 35, OSS 42 vs 46, CMS 71 vs 86, SSV 84% vs 92%, respectively. ROM was superior with the NRB (elevation 159°, ER 47° and IR score 8 vs 140°, 37° and 7 with SS). Conclusions: Despite being a small series, our results demonstrate a trend towards NRB providing better outcomes. This feasibility study supports the need for a larger multi-centre randomised controlled trial comparing these immobilisation methods for PHF.

Developing a machine learning algorithm to predict the probability of aseptic loosening of the glenoid component after anatomical total shoulder arthroplasty: protocol for a retrospective, multicentre study.

INTRODUCTION: Despite technological advancements in recent years, glenoid component loosening remains a common complication after anatomical total shoulder arthroplasty (ATSA) and is one of the main causes of revision surgery. Increasing emphasis is placed on the prevention of glenoid component failure. Previous studies have successfully predicted range of motion, patient-reported outcomes and short-term complications after ATSA using machine learning methods, but an accurate predictive model for (glenoid component) revision is currently lacking. This study aims to use a large international database to accurately predict aseptic loosening of the glenoid component after ATSA using machine learning algorithms. METHODS AND ANALYSIS: For this multicentre, retrospective study, individual patient data will be compiled from previously published studies reporting revision of ATSA. A systematic literature search will be performed in Medline (PubMed) identifying all studies reporting outcomes of ATSA. Authors will be contacted and invited to participate in the Machine Learning Consortium by sharing their anonymised databases. All databases reporting revisions after ATSA will be included, and individual patients with a follow-up less than 2 years or a fracture as the indication for ATSA will be excluded. First, features (predictive variables) will be identified using a random forest feature selection. The resulting features from the compiled database will be used to train various machine learning algorithms (stochastic gradient boosting, random forest, support vector machine, neural network and elastic-net penalised logistic regression). The developed and validated algorithms will be evaluated across discrimination (c-statistic), calibration, the Brier score and the decision curve analysis. The best-performing algorithm will be used to create an open-access online prediction tool. ETHICS AND DISSEMINATION: Data will be collected adhering to the WHO regulation on data sharing. An Institutional Review Board review is not applicable. The study results will be published in a peer-reviewed journal.