Artificial Intelligence Machine Learning Algorithms Versus Standard Linear Demographic Analysis in Predicting Implant Size of Anatomic and Reverse Total Shoulder Arthroplasty.

BACKGROUND: Accurate and precise templating is paramount for anatomic total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RSA) to enhance preoperative planning, streamline surgery, and improve implant positioning. We aimed to evaluate the predictive potential of readily available patient demographic data in TSA and RSA implant sizing, independent of implant design. METHODS: A total of 578 consecutive, primary, noncemented shoulder arthroplasty cases were retrospectively reviewed. Demographic variables and implant characteristics were recorded. Multivariate linear regressions were conducted to predict implant sizes using patient demographic variables. RESULTS: Linear models accurately predict TSA implant sizes within 2 millimeters of humerus stem sizes 75.3% of the time, head diameter 82.1%, head height 82.1%, and RSA glenosphere diameter 77.6% of the time. Linear models predict glenoid implant sizes accurately 68.2% and polyethylene thickness 76.6% of the time and within one size 100% and 95.7% of the time, respectively. CONCLUSION: Linear models accurately predict shoulder arthroplasty implant sizes from demographic data. No significant statistical differences were observed between linear models and machine learning algorithms, although the analysis was underpowered. Future sufficiently powered studies are required for more robust assessment of machine learning models in predicting primary shoulder arthroplasty implant sizes based on patient demographics.

Bony encasement of the ulnar nerve secondary to heterotopic ossification of the elbow: an evaluation of long-term outcomes.

BACKGROUND: Ulnar neuropathy at the elbow caused by heterotopic ossification (HO) is a rare condition. This retrospective study aims to report on 32 consecutive cases of ulnar nerve encasement caused by elbow HO and evaluate long-term outcomes of operative management and a standardized postoperative rehabilitation regimen. METHODS: A retrospective case series was conducted on 32 elbows (27 patients) that underwent operative management of bony ulnar nerve encasement. All procedures were performed in the inpatient setting at an Academic Level 1 Trauma Center from September 1999 to July 2021 by one of 3 fellowship-trained shoulder and elbow. Postoperatively, all patients received formal physical therapy, HO prophylaxis (30 received indomethacin, 2 received radiation), and a structured continuous passive motion machine regimen. Patient demographics, age, gender, type of injury, history of tobacco use, and medical comorbidities were obtained to include in the analysis. Long-term follow-up examinations were performed to evaluate elbow flexion-extension arc of motion, Mayo Elbow Performance Score, and visual analog scale pain scores. RESULTS: Thirty-two elbows with complete bony ulnar nerve encasement secondary to HO were identified (14 from burns, 15 from trauma, 3 closed head injuries). Following surgery, the mean flexion-extension arc of motion improved significantly, increasing from 21° to 100° at long-term follow-up (average 8.7 years, range 2-17 years), with statistically significant improvements in preoperative vs. long-term postoperative elbow extension (P < .001), flexion (P < .001), and total arc of motion (P < .001). There was a statistically significant improvement in pre- vs. postprocedure ulnar nerve function, as demonstrated by a decrease in average McGowan grade (1.2-0.7; P = .002). Additionally, 63% of patients with preoperative ulnar neuropathy symptoms (20/32) had either complete resolution or subjective improvement after surgery. The mean time from injury to surgery was 518 days (range 65-943 days). Age, gender, time to surgery, and medical comorbidities were not associated with outcomes. The complication rate was 9% (3/32). Patients had an average flexion-extension arc of motion of 97° and average Mayo Elbow Performance Score of 80 ("good") at long-term follow-up. CONCLUSIONS: The combination of operative management, postoperative HO prophylaxis, and a regimented rehabilitation program has proven to be a durable solution for treating and ensuring good long-term functional outcomes for patients with elbow HO and bony ulnar nerve encasement. This treatment approach leads to superior range of motion, improved or resolved ulnar neuropathy, and good to excellent long-term functional outcomes.

The impact of modern airport security protocols on patients with total shoulder replacements.

BACKGROUND: Advancements in airport screening measures in response to 9/11 have resulted in increased false alarm rates for patients with orthopedic and metal implants. With the implementation of millimeter-wave scanning technology, it is important to assess the changes in airport screening experiences of patients who underwent total shoulder arthroplasty (TSA). METHODS: Here, 197 patients with prior anatomic and reverse TSA completed between 2013 and 2020 responded to a questionnaire regarding their experiences with airport travel screening after their operation. Of these patients, 86 (44%) stated that they had traveled by plane, while 111 (56%) had not. The questionnaire addressed several measures including the number of domestic and international flights following the operation, number of false alarm screenings by the millimeter-wave scanner, patient body habitus, and presence of additional metal implants. RESULTS: A total of 53 patients (62%) responded "yes" to false screening alarms due to shoulder arthroplasty. The odds of a false screening alarm for patients with other metal implants was 5.87 times that of a false screening alarm for patients with no other metal implants (P<0.1). Of a reported 662 flights, 303 (45.8%) resulted in false screening alarms. Greater body mass index was not significantly lower in patients who experienced false screening alarms (P=0.30). CONCLUSIONS: Patients with anatomic and reverse TSA trigger false alarms with millimeter-wave scanners during airport screening at rates consistent with prior reports following 9/11. Patient education on the possibility of false alarms during airport screening is important until improvements in implant identification are made. Level of evidence: IV.

An objective assessment of the impact of tendon retraction on sleep efficiency in patients with full-thickness rotator cuff tears: a prospective cohort study.

BACKGROUND: Sleep quality, quantity, and efficiency have all been demonstrated to be adversely affected by rotator cuff pathology. Previous measures of assessing the impact of rotator cuff pathology on sleep have been largely subjective in nature. This study was undertaken to objectively analyze this relationship through the use of activity monitors. METHODS: Patients with full-thickness rotator cuff tears at a single institution were prospectively enrolled between 2018 and 2020. Waistworn accelerometers were provided for the patients to use each night for 14 days. Sleep efficiency was calculated using the ratio of the time spent sleeping to the total amount of time that was spent in bed. Retraction of the rotator cuff tear was classified using the Patte staging system. RESULTS: This study included 36 patients: 18 with Patte stage 1 disease, 14 with Patte stage 2 disease, and 4 patients with Patte stage 3 disease. During the study, 25 participants wore the monitor on multiple nights, and ultimately their data was used for the analysis. No difference in the median sleep efficiency was appreciated amongst these groups (P>0.1), with each cohort of patients demonstrating a generally high sleep efficiency. CONCLUSIONS: The severity of retraction of the rotator cuff tear did not appear to correlate with changes in sleep efficiency for patients (P>0.1). These findings can better inform providers on how to counsel their patients who present with complaints of poor sleep in the setting of full-thickness rotator cuff tears. Level of evidence: Level II.

Delayed Repair of a Lesser Tuberosity Avulsion Fracture in an Adolescent 3 Years After Initial Injury.

This case study examines an adolescent athlete who had an avulsion fracture of the lesser tuberosity of the humerus. This is a relatively rare injury, although a collection of case studies have identified an increase in this type of injury in the past 15 years. Uniquely, the patient experienced a delay in appropriate diagnosis for approximately 3 years from the time of his initial injury. This is one of the most significant delays in diagnosis and treatment in the current body of literature regarding lesser tuberosity fractures. The authors include a detailed series of imaging studies, including preoperative plain radiographs, preoperative computed tomography, intraoperative arthroscopic images, and postoperative plain radiographs. In addition, a thorough description of the patient's surgery is presented. The degree of scarring to the axillary nerve present in this patient required conversion to a full open reduction. The authors' aim is that this case can be used as a reference for future surgical decision making, particularly in pediatric patients whose injuries are highly chronic or who are actively involved in athletic physical training programs. [Orthopedics. 2023;46(3):e189-e192.].

Core decompression for early-stage avascular necrosis of the humeral head: current concepts and techniques.

Avascular necrosis (AVN) of the humeral head is a rare, yet detrimental complication. Left untreated, humeral head AVN frequently progresses to subchondral fracturing and articular collapse. Cases of late-stage humeral head AVN commonly require invasive procedures including humeral head resurfacing, hemiarthroplasty, and total shoulder arthroplasty (TSA) to improve clinical outcomes. However, in cases of early-stage AVN, core decompression of the humeral head is a viable and efficacious short-term treatment option for patients with pre-collapse AVN of the humeral head to improve clinical outcomes and prevent disease progression. Several techniques have been described, however, a percutaneous, arthroscopic-assisted technique may allow for accurate staging and concomitant treatment of intraarticular pathology during surgery, although further long-term clinical studies are necessary to assess its overall outcomes compared with standard techniques. Biologic adjunctive treatments, including synthetic bone grafting, autologous mesenchymal stem cell/bone marrow grafts, and bone allografts are viable options for reducing the progression of AVN to further collapse in the short term, although long-term follow-up with sufficient study power is lacking in current clinical studies. Further long-term outcome studies are required to determine the longevity of core decompression as a conservative measure for early-stage AVN of the humeral head.

Health care disparities in surgical treatment of rotator cuff disease.

Background: Health care disparities have been well-documented in literature to affect care and recovery after surgery. Insurance type is regularly cited by orthopedic surgeons to play a role in the incongruences faced by patients in the perioperative period. Recent trends highlight an increased reluctance by some insurance companies to approve indicated surgery. Our primary objective was to assess insurance type and how it affects approval rates for rotator cuff débridement and rotator cuff repair. Methods: A retrospective review of 999 patients who underwent arthroscopic rotator cuff débridement or repair was conducted. Data abstraction included demographics, prior surgical or nonsurgical interventions, radiologic imaging, insurance type, and denial of insurance coverage. Patients were grouped by insurance type-Medicaid, Medicare, workers' compensation, and private insurance. Univariable and multivariable logistic regression models were developed to estimate odds ratios (ORs) for insurance type associated with the denial of insurance coverage. Results: Nine hundred ninety-seven patients were included in our final analysis. Those with private insurance were more likely to be non-Hispanic white (71%), whereas the proportion of Hispanics was highest among those with workers' compensation (27%) and Medicaid (20%). There were no significant differences by insurance type for prior nonsurgical interventions and radiologic imaging. For previous surgical interventions (13%), however, rates were higher for Medicaid (18%) and workers' compensation (17%) than those for Medicare (12%) and private insurance (9%) (P = .003). Compared with private insurance, the odds of insurance denial were significantly higher for those with Medicaid at 54% (OR: 7.91, 95% confidence interval: 5.27-11.88, P < .001) and workers' compensation at 19% (OR: 1.71, 95% confidence interval: 1.04-2.81, P = .04). Discussion: One in 2 patients with Medicaid coverage faces insurance denial compared with any other insurance type. Workers' compensation follows with the second highest rates. Almost half the Hispanic population are insured by either Medicaid or workers' compensation and may face barriers to care that can negatively impact outcomes and complication rates.

Surgically Treated Pectoralis Major Tears Impact the Play and Performance of National Football League Athletes.

Purpose: To evaluate the return-to-play rate and performance level changes in National Football League (NFL) athletes after a surgically treated pectoralis major muscle (PMM) tear. Methods: A descriptive epidemiologic study was conducted. All NFL players from 1933 to 2013 were reviewed for surgically treated PMM tears. Age at injury, height, weight, body mass index, date of injury, position played, draft selection, and total seasons played were recorded. Return to play was assessed for the entire cohort, as well as by position. Performance analysis before and after injury was also conducted for the entire cohort, as well as by position and draft selection. Data analysis was performed with the paired-samples t test, with P < .05 considered statistically significant. Results: Our review of 80 NFL seasons from 1933 to 2013 provided a total of 55 instances of PMM tears. All instances occurred between the time frame of 2004 and 2012. After exclusions, 24 instances unique to 24 NFL athletes were confirmed by 2 separate investigators and these athletes were included as our final study cohort. Of the 24 players identified to have a surgically repaired PMM tear, 20 (83%) returned to play. The mean return-to-play period was 302 ± 128 days. The mean difference in performance scores before versus after PMM injury was 171.33 and was statistically significant, with P = .0330. Conclusions: In this study, there was an 83% return-to-play rate after surgical repair of PMM tears. Although we found a statistically significant decrease in player performance after surgery, this difference was no longer seen after players were stratified by position type and draft selection. Level of Evidence: Level IV, therapeutic case series.

The Long Head of the Biceps Myotendinous Junction Is Located 1.14 Centimeters Distal to the Proximal Border of the Pectoralis Major Tendon: An Anatomic Study.

Purpose: To describe the proportional anatomic relationship of the long head of the biceps tendon (LHBT) myotendinous junction (MTJ) to pectoralis major tendon (PMT) and to provide an up-to-date review of the current literature. Methods: Ten fresh frozen cadaveric specimens were used. A deltopectoral approach was used for exposure and anatomical location of the MTJ as well as the proximal and distal borders of the PMT were identified by 2 fellowship-trained shoulder and elbow surgeons. The longitudinal length of the PMT, the distance from the long head of the biceps (LHB) MTJ to the proximal border of the PMT (pMTJ), and the distance from the LHB MTJ to the distal border of the PMT (dMTJ) were recorded. The relationship between the pMTJ and the PMT length was then reported as a ratio. Results: The PMT was found to have a length of 5.16 ± 0.64 cm (4.1-6.1 cm). The pMTJ was 1.14 ± 0.52 cm (0.5-1.9 cm), and the dMTJ was 4.02 ± 0.91 cm (2.5-5.3 cm). The pMTJ/PMT ratio was 0.23 ± 0.11 (0.10-0.39). Conclusions: We found the average length of the PMT footprint to be 5.16 cm with the LHB MTJ beginning 1.14 cm distal to its proximal border. Clinical Relevance: It is important to understand the LHBT and its relationship to surgically relevant surrounding anatomy to allow for appropriate tensioning and improved patient outcomes in the treatment of LHBT shoulder pathology.

Bubble Sign: An Arthroscopic Technical Trick to Differentiate Between Partial- and Full-Thickness Rotator Cuff Tears.

Distinguishing between partial-thickness and small focal full-thickness tears of rotator cuff may be important for determining the appropriate surgical treatment options and repair constructs in the care of patients with rotator cuff pathology. This article presents a simple intraoperative technical trick to aid in identification of small full-thickness tears of the superior rotator cuff. The relatively higher-pressured subacromial space and the low-pressured glenohumeral joint are separated by the supraspinatus tendon. When this barrier is compromised due to a full-thickness tear, free fluid flows from high to low pressure down the native pressure gradient. This is seen as the movement of air bubbles into the glenohumeral joint from the subacromial space and can be used to identify the presence of a full-thickness rotator cuff tear on diagnostic arthroscopy.

Delayed surgical repair of the deltoid following acromioplasty: a case report.

Currently, the literature contains few studies that describe any potential complications following arthroscopic acromioplasty. Because part of the anterior deltoid originates from the anterior acromion, there is a risk for violation and subsequent iatrogenic rupture or avulsion during this procedure. This type of injury can be a devastating problem for patients that may lead to poor function and debilitating pain. We present a patient with deltoid insufficiency following arthroscopic acromioplasty who elected to proceed with operative management with a planned arthroscopic evaluation of the shoulder followed by an open deltoid repair. At the final follow-up visit 2.5 years postoperatively, the patient reported improved pain from baseline and no residual disability and was able to perform most activities of daily living without difficulty. This case serves as an example of a surgical repair for a deltoid avulsion following arthroscopic acromioplasty. As there is still a lack of standard guidelines, our suture repair technique can be considered one method of treatment for this type of injury.

Acromiohumeral cerclage in reverse total shoulder arthroplasty for recurrent instability.

BACKGROUND: Recurrent shoulder instability after reverse total shoulder arthroplasty (rTSA) presents a challenging clinical problem. A handful of cases have been reported describing stability achieved only after revision rTSA with cerclage augmentation. We describe an acromiohumeral cerclage technique, where the humeral component is fixed with a nonabsorbable, high-tensile suture tape looped through transosseous acromial drill tunnels as an augment to salvage shoulder stability. METHODS: All patients treated with acromiohumeral cerclage in rTSA for instability between November 1, 2015, and February 1, 2020, with minimum 1-year follow-up were included. Demographic information, baseline preoperative and postoperative range of motion at most recent follow-up, American Shoulder and Elbow Surgeons (ASES) shoulder scores, and visual analog scale (VAS) scores were recorded and compared. RESULTS: Ten patients, 4 female and 6 male, aged 64.3 ± 7.4 years (range, 53-77 years) with the mean postoperative follow-up of 23 months were included; 90% underwent surgery on the dominant side. Patients underwent an average of 2.1 ± 1.9 prior revisions (range, 0-7), over an average of 10.4 months (range, 0-72 months), before revision with suture cerclage augmentation was performed. All patients either had significant past shoulder history at other institutions and/or comorbidities that added significant complexity to their cases, with an average of 0.6 ± 0.9 (range, 0-3) prior other shoulder operations performed before their initial rTSA. The average decrease in VAS score among the 10 patients was 4.3 ± 2.7 (P < .05), ranging from 0 to 8 points. The average increase in ASES score was 51.3 ± 21 (P < .05), ranging from 13.3 to 69.9 points. The average increase in active forward elevation for 8 patients was 79° ± 39° (P = .0008), ranging from 40° to 160°. All patients have remained stable with well-positioned prostheses since their final operations with no recurrent dislocations or acromial complications. Two patients unable to travel for an office visit were contacted via phone and answered questions to obtain postoperative ASES and VAS scores. CONCLUSION: Acromiohumeral cerclage suture augmentation in revision rTSA may be a useful, simple surgical strategy to employ with other revision and augmentation techniques to treat cases of recurrent, chronic instability, particularly in the setting of multiple revisions.

Effect of Insurance Status on Clinical Outcomes After Shoulder Arthroplasty.

Shoulder arthroplasty is an effective treatment option for patients with symptomatic shoulder arthritis and rotator cuff arthropathy. Although there have been reports of variations in complication rates according to insurance type, few studies have examined the effect of payer status on functional outcomes. Patients who underwent elective shoulder arthroplasty performed by a single fellowship-trained surgeon and had a minimum of 1 year of follow-up were queried. Patient characteristics were compared across insurance types. Each patient completed the American Shoulder and Elbow Surgeons (ASES) questionnaire preoperatively and postoperatively. A generalized linear mixed model was specified to predict ASES score at 1 year and included preoperative ASES score as an adjustment variable. A total of 84 patients underwent 91 procedures. Before surgery, ASES score differed by insurance type (P=.014), with lower scores in the Medicaid cohort compared with the private insurance cohort (20.4 vs 38.8, P=.009). After controlling for baseline ASES score, postoperative ASES score at 1-year follow-up differed by insurance type (P<.001). Patients with private insurance had better ASES scores (85.6) than patients with Medicaid (55.2) (P<.001) and workers' compensation (57.1) (P=.028). Patients with Medicare (80.6) had better ASES scores at follow-up compared with those with Medicaid (P<.001). Patients with Medicaid are at risk for significantly lower postoperative functional outcome scores after shoulder arthroplasty compared with patients with private insurance and Medicare. In this study, patients with Medicaid had lower preoperative ASES scores compared with other groups. These observed differences are likely multifactorial and should be acknowledged when counseling patients. [Orthopedics. 2020;43(6):e523-e528.].

Repairing PASTA Lesions Without Violation of the Rotator Cuff.

Partial-thickness articular-sided rotator cuff tears are a common cause of shoulder pain in adults. Although partial rotator cuff tears have a high prevalence, there is still controversy over their proper surgical treatment. Different surgical procedures have been suggested when partial tears involve the articular side of the rotator cuff, such as arthroscopic debridement of the tear with or without acromioplasty, tear completion and repair, and transtendinous in situ repair. Although multiple repair techniques have been described, significant clinical data to definitively support one technique over the others are currently lacking. We describe an arthroscopic technique for repair of a partial articular supraspinatus tendon avulsion that avoids the transtendinous insertion of suture anchors to preserve the tendon integrity.

Improving the safety of shoulder arthroscopy in the beach chair position: a prospective randomized trial investigating the effect of compression stockings on cerebral desaturation events in obese patients.

BACKGROUND: Devastating transient and permanent postoperative neurocognitive complications in previously healthy, low-risk patients have been observed after elective shoulder arthroscopy in the beach chair position (BCP). Continuous monitoring of cerebral oxygen saturation has been recommended to identify cerebral desaturation events (CDEs) and improve patient safety. However, the relatively high cost and limited availability of monitoring may not be cost-effective. More cost-effective and available measures, including the use of thigh-high compression stockings (CS), have been investigated. However, efficacy data of CS usage is limited, especially for obese patients, who have been shown to be at increased risk for CDEs. The purpose of this was study was to determine if the intraoperative addition of thigh-high compression stockings decreases the incidence, frequency, and magnitude of CDEs in obese patients undergoing shoulder arthroscopy in the BCP. METHODS: Thirty-three patients in the treatment group wore both thigh-high compression stockings (CS) and sequential compression devices (SCDs), and the remaining 33 patients in the control group wore SCDs alone. Cerebral oximetry was monitored during surgery using near-infrared spectroscopy. RESULTS: The incidence of CDEs was equal between groups, with 9 patients (27%) in each experiencing desaturation events. The median number of CDEs per patient was 3 for the control group and 1 for patients wearing CS (P = .29). There was no difference between groups in terms of median time from induction of anesthesia to onset of CDE (P = .79), median time from upright positioning to onset of CDE (P = .60), mean CDE duration per patient (P = .22), and median cumulative CDE duration (P = .19). The median maximal desaturation from baseline was also not different between groups: 27.6% in the control group and 24.3% in the treatment group (P = .35). CONCLUSION: The combination of thigh-high CS and SCDs did not decrease the incidence, frequency, or magnitude of CDEs in patients undergoing shoulder arthroscopy in the BCP. Twenty-seven percent of patients undergoing shoulder arthroscopy in the BCP demonstrated CDEs with or without the use of CS. Therefore, further research is required to identify cost-effective, minimally invasive, and universally available methods of decreasing the incidence of CDEs during this common surgical procedure.

The effect of pulsed lavage irrigation on suture knot security.

PURPOSE: The purpose of this study was to determine the effect of low-pressure and pulsed lavage irrigation on suture knot security. METHODS: Ninety-tied suture loops were measured for baseline circumference and then subjected to no irrigation, bulb syringe irrigation, or pulsed lavage irrigation. The sutures were placed under a load and then measured for final circumference. A larger circumference difference indicated poorer knot security. RESULTS: There was a statistically significant difference in the knot security between all three groups (p < 0.001). Pulsed lavage resulted in the greatest circumference increase (0.52 ± 0.19 mm), followed by bulb syringe (0.24 ± 0.18 mm), and lastly no irrigation (0.08 ± 0.00 mm). None of the groups had any catastrophic failures. No knots met the predetermined criteria for knot failure. CONCLUSION: Pulsed lavage irrigation resulted in a statistically significant decrease in suture knot security as compared to bulb syringe irrigation and no irrigation. None of the groups met the currently accepted criteria for clinical suture failure, which has a relatively arbitrary value. While the available literature does not discuss increases in loop circumference for specific orthopedic applications, this small difference suggests that pulse lavage is unlikely to have a clinically significant impact on the suture integrity for most orthopedic procedures.

Synovial Non-langerhans Cell Histiocytosis of the Shoulder: A Case Report and Review of the Literature.

INTRODUCTION: Histiocytoses are rare disorders and most orthopedic surgeons are unfamiliar with this diagnosis. We report a case of synovial non-Langerhans cell histiocytosis (LCH) located in the shoulder, which has not been reported in the literature previously. CASE REPORT: A 24-year-old female patient presented to our clinic with shoulder pain and decreased range of motion. MRI results suggested pigmented villonodular synovitis. Arthroscopic synovial debridement and biopsy were performed. Histologic examination came back as non-LCH of the shoulder. Hematology/oncology evaluation indicated localized disease and no further treatment was necessary. At the 6th month follow-up, the patient gained full shoulder motion and is symptom free. CONCLUSION: This case represents a rare diagnosis of synovial non-LCH which should be considered in the differential diagnosis of synovial diseases. A misdiagnosis could result in inadequate treatment, and coordination with the hematology/oncology department is of utmost importance in the treatment of this neoplastic disease.