Ultrasonographic evaluation of ulnar nerve morphology in patients with ulnar nerve instability.

INTRODUCTION/AIMS: Ulnar nerve instability (UNI) in the retroepicondylar groove is described as nerve subluxation or dislocation. In this study, considering that instability may cause chronic ulnar nerve damage by increasing the friction risk, we aimed to examine the effects of UNI on nerve morphology ultrasonographically. METHODS: Asymptomatic patients with clinical suspicion of UNI were referred for further clinical and ultrasonographic examination. Based on ulnar nerve mobility on ultrasound, the patients were first divided into two groups: stable and unstable. The unstable group was further divided into two subgroups: subluxation and dislocation. The cross-sectional area (CSA) of the nerve was measured in three regions relative to the medial epicondyle (ME). RESULTS: In the ultrasonographic evaluation, UNI was identified in 59.1% (52) of the 88 elbows. UNI was bilateral in 50% (22) of the 44 patients. Mean CSA was not significantly different between groups. A statistically significant difference in ulnar nerve mobility was found between the group with CSA of <10 versus ≥10 mm2 (p = .027). Nerve instability was found in 85.7% of elbows with an ulnar nerve CSA value of ≥10 mm2 at the ME level. DISCUSSION: The probability of developing neuropathy in patients with UNI may be higher than in those with normal nerve mobility. Further prospective studies are required to elucidate whether asymptomatic individuals with UNI and increased CSA may be at risk for developing symptomatic ulnar neuropathy at the elbow.

Comparison of the diagnostic performance of the Swischuk line method and the anterior atlantodental interval method in atlantodental subluxation.

BACKGROUND: Atlantodental subluxation (ADS) is a serious condition that can result in sudden death. Measuring the anterior atlantodental interval (AADI method) is the gold standard for diagnosis but the complex anatomy of this region can make diagnosis difficult, especially for beginners. Therefore, we would like to use a simpler method, the Swischuk line method, to diagnose ADS. The purpose of our study was to evaluate the diagnostic performance of the Swischuk line method for ADS on lateral cervical spine radiographs compared to the AADI method. METHODS: A retrospective study was conducted with patients who presented with ADS (ADS group, n = 32, mean age 57.78 years, age range 34-82 years, 10 men, 21 women) and an age- and sex-matched control group (n = 32). The diagnostic performance of the AADI method and the Swischuk line method for ADS was assessed using lateral cervical radiographs in both flexion and neutral postures by an experienced musculoskeletal radiologist (reader 1), a senior resident (reader 2), and a junior resident (reader 3) in the radiologic department. RESULTS: In the flexion posture, the AADI method and the Swischuk line method showed excellent diagnostic performance with AUCs > 0.9 for readers 1 2 and reader 3. In a neutral posture, the diagnostic performance of the AADI and Swischuk line methods was decreased. With a 1 mm cut-off value using the Swischuk line method in flexion posture, the sensitivity was 75% or more, the specificity was 100%, and the accuracy was 87.50% or more 90.63% for all readers. With a 2 mm cut-off value, the sensitivity was low (37.50-46.88%) but the specificity was 100% for all three readers. In a neutral posture, the sensitivity for both methods decreased, though specificity remained high (> 80%). CONCLUSIONS: The Swischuk line method was found to be reliable and showed high sensitivity and specificity with a cut-off value of 1 mm for the diagnosis of ADS in cervical lateral radiographs in flexion posture. It can be used as a complement to the AADI method.

Lens subluxation combined with parry-romberg syndrome: case report.

BACKGROUND: Parry-Romberg syndrome (PRS) is a rare progressive degenerative disorder of unknown etiology. Here we report a rare case of PRS combined with lens subluxation in Eye and ENT hospital of Fudan University, Shanghai. To our knowledge, it is the first reported case of PRS combined with lens subluxation that has been managed surgically with phacoemulsification and CTR placement and IOL implantation in Shanghai. CASE PRESENTATION: A 60-year-old woman was referred for "right visual blur for 2 years" and had persistent right facial paralysis of unknown etiology since the age 12. She had right facial muscle atrophy and paralysis. Eye examination also showed the right eyelid pseudoptosis, enophthalmos, age-related cataract combined with lens subluxation existed in the right eye. The patient was diagnosed as age-related cataract and lens subluxation in the right eye and progressive hemifacial atrophy (Parry-Romberg syndrome). We conducted a combined phacoemulsification, IOL and CTR implantation and pupilloplasty surgery for the patient under general anesthesia and the postoperative UCVA was 20/30 and remained for 1 year's follow up. CONCLUSIONS: Here we reported a rare case of PHA combined with lens subluxation in China. After appropriate eye surgery, the patient achieved satisfying vision result in the right eye.

Myelopathy resulting from degenerative atlantoaxial subluxation.

PURPOSE: To present the clinical features and treatment strategy of degenerative atlantoaxial subluxation (DAAS). METHODS: Patients with DAAS treated in our institution from 2003 to 2020 were retrospectively reviewed. We utilized the Japanese Orthopedic Association (JOA) scale to evaluate the neurologic status and distance of Ranawat et al. (DOR) to measure vertical migration. RESULTS: We recruited 40 patients with > 2 years of follow-up and an average age of 62.3 ± 7.7 years. All the patients had myelopathy; only one patient had moderate trauma before exacerbation of symptoms, and the duration of symptoms was 34 ± 36 months. The most frequent radiological features were vertical migration of C1 (100%), sclerosis (100%), and narrowing of the atlantoaxial lateral mass articulations (100%). Two patients underwent transoral release combined with posterior reduction and fusion, and 38 patients underwent posterior reduction and fusion with C1 lateral mass screws-C2 pedicle screws and plate systems only. Forty cases (100%) achieved a solid atlantoaxial fusion, and 38 cases (95%) achieved anatomic atlantoaxial reduction. The JOA score increased from 9.3 ± 2.6 to 14.8 ± 2.1 (P < 0.01). DOR increased from 14.5 ± 2.5 to 17.8 ± 2.2 mm at the final follow-up (P < 0.01). Loosening of the locking caps was detected in one case, bony fusion was achieved, and harvest-site pain was reported in five patients. CONCLUSION: DAAS differs from other types of AAS and presents with anterior subluxation combined with vertical subluxation arising from degenerative changes in the atlantoaxial joints. We recommend anatomic reduction as an optimal strategy for DAAS.

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.

Are glenoid retroversion, humeral subluxation, and Walch classification associated with a muscle imbalance?

BACKGROUND: The etiology of humeral posterior subluxation remains unknown, and it has been hypothesized that horizontal muscle imbalance could cause this condition. The objective of this study was to compare the ratio of anterior-to-posterior rotator cuff and deltoid muscle volume as a function of humeral subluxation and glenoid morphology when analyzed as a continuous variable in arthritic shoulders. METHODS: In total, 333 computed tomography scans of shoulders (273 arthritic shoulders and 60 healthy controls) were included in this study and were segmented automatically. For each muscle, the volume of muscle fibers without intramuscular fat was measured. The ratio between the volume of the subscapularis and the volume of the infraspinatus plus teres minor (AP ratio) and the ratio between the anterior and posterior deltoids (APdeltoid) were calculated. Statistical analyses were performed to determine whether a correlation could be found between these ratios and glenoid version, humeral subluxation, and/or glenoid type per the Walch classification. RESULTS: Within the arthritic cohort, no statistically significant difference in the AP ratio was found between type A glenoids (1.09 ± 0.22) and type B glenoids (1.03 ± 0.16, P = .09), type D glenoids (1.12 ± 0.27, P = .77), or type C glenoids (1.10 ± 0.19, P > .999). No correlation was found between the AP ratio and glenoid version (ρ = -0.0360, P = .55) or humeral subluxation (ρ = 0.076, P = .21). The APdeltoid ratio of type A glenoids (0.48 ± 0.15) was significantly greater than that of type B glenoids (0.35 ± 0.16, P < .01) and type C glenoids (0.21 ± 0.10, P < .01) but was not significantly different from that of type D glenoids (0.64 ± 0.34, P > .999). When evaluating both healthy control and arthritic shoulders, moderate correlations were found between the APdeltoid ratio and both glenoid version (ρ = 0.55, P < .01) and humeral subluxation (ρ = -0.61, P < .01). CONCLUSION: This in vitro study supports the use of software for fully automated 3-dimensional reconstruction of the 4 rotator cuff muscles and the deltoid. Compared with previous 2-dimensional computed tomography scan studies, our study did not find any correlation between the anteroposterior muscle volume ratio and glenoid parameters in arthritic shoulders. However, once deformity occurred, the observed APdeltoid ratio was lower with type B and C glenoids. These findings suggest that rotator cuff muscle imbalance may not be the precipitating etiology for the posterior humeral subluxation and secondary posterior glenoid erosion characteristic of Walch type B glenoids.

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at minimum 5-year follow-up.

BACKGROUND: In patients with glenohumeral osteoarthritis and posteriorly eccentric wear patterns, the early to mid-term results of TSA using conservative glenoid reaming with no attempt at version correction have been favorable at early follow-up. The purpose of this study is to compare the clinical and radiographic outcomes of TSA using this technique for patients with and without eccentric wear patterns at a minimum 5-year follow-up. METHODS: Patients who underwent TSA with minimum 5-year follow-up were identified from an institutional registry. Preoperative and postoperative radiographs were used to determine humeroglenoid alignment (HGA-AP), humeroscapular alignment (HSA-AP), version, Walch classification and glenoid component seating. The outcome measures were the Simple Shoulder Test, glenoid component radiolucencies, and the occurrence of complications or revisions. RESULTS: Two hundred and ten patients were included in the study, of which 98 (47%) had posteriorly decentered humeral heads and 108 (51%) had centered humeral heads. There were 77 shoulders with Walch type A glenoids and 122 with Walch type B glenoids. At a mean 8-year follow-up, the final SST, change in SST and percentage of maximal improvement was not correlated with pre- and postoperative humeral head centering, Walch classification or glenoid version. There were no preoperative predictors of a low final SST. Two patients (1%) underwent open re-operations during the study period. In patients with Walch B1 and B2 glenoids (n=110), there were no differences in outcome measures between patients with postoperative retroversion of more and less than 15o. While 15 of 51 patients (29%) with minimum 5-year radiographs had glenoid radioluciences, these radiographic findings were not associated with inferior clinical outcomes. On multivariable analysis glenoid component radiolucencies were most strongly associated with incomplete component seating (OR 3.3, p = 0.082). CONCLUSION: The results of TSA with conservative glenoid reaming without attempt at version correction are favorable at minimum 5 year, mean 8-year follow-up. There were no differences in clinical and radiographic outcomes between patients with eccentric and concentric wear patterns. Incomplete glenoid component seating was the greatest predictor of glenoid component radiolucency, but these radiolucencies were not associated with inferior clinical outcomes.

Arthroscopic Bankart Repair with Remplissage Yields Similar Outcomes to Open Latarjet for Primary and Revision Stabilization in The Setting of Subcritical Glenoid Bone Loss.

BACKGROUND: Management of patients with recurrent anterior glenohumeral instability in the setting of subcritical glenoid bone loss (GBL), defined in this study as 20% GBL or less, remains controversial. This study aimed to compare arthroscopic Bankart with remplissage (ABR+R) to open Latarjet for subcritical GBL in primary or revision procedures. We hypothesized that ABR+R would yield higher rates of recurrent instability and reoperation compared to Latarjet in both primary and revision settings. METHODS: A retrospective study was conducted on patients undergoing either arthroscopic ABR+R or an open Latarjet procedure. Patients with connective tissue disorders, critical GBL (>20%), < 2 year follow-up, or insufficient data were excluded. Recurrent instability and revision were the primary outcomes of interest. Additional outcomes of interest included subjective shoulder value (SSV), strength and range of motion (ROM) RESULTS: 108 patients (70 ABR+R, 38 Latarjet) were included with an average follow-up of 4.3 ±2.1 years. In the primary and revision settings, similar rates of recurrent instability (Primary: p=0.60; Revision: p=0.28) and reoperation (Primary: p=0.06; Revision: p=1.00) were observed between Latarjet and ABR+R. Primary ABR+R exhibited better SSV, active ROM, and internal rotation strength compared to primary open Latarjet. However, no differences were observed in the revision setting. CONCLUSION: Similar rates of recurrent instability and reoperation in addition to comparable outcomes with no differences in ROM were found for ABR+R and Latarjet in patients with subcritical GBL in both the primary and revision settings. ABR+R can be a safe and effective procedure in appropriately selected patients with less than 20% GBL for both primary and revision stabilization.

A novel classification of intraoperative ulnar nerve instability to aid transposition surgery.

HYPOTHESIS: The purpose of this study was to compare inter- and intraobserver agreement of a novel intraoperative subluxation classification for patients undergoing ulnar nerve surgery at the elbow. We hypothesize there will be strong inter- and intraobserver agreement of the 4-category classification system, and reviewers will have substantial confidence while reviewing the classification system. METHODS: Four blinded fellowship-trained orthopedic hand surgeons reviewed 25 videos in total on 2 separate viewings, 21 days apart. Variables collected were ulnar subluxation classification (A, B, C, or D) and a confidence metric. Subsequent to primary data collection, classification grading was stratified into A/B or C/D subgroups for further analysis. Cohen κ scores were used to evaluate all variables collected in this study. The interpretation of κ scores included ≤0.0 as no agreement, 0.01-0.20 as none to slight, 0.21-0.40 as fair, 0.41-0.60 as moderate, 0.61-0.80 as substantial, and 0.81-1.0 as almost perfect agreement. RESULTS: Interobserver agreement of subluxation classification as a 4-category scale demonstrated a moderate agreement on first viewing, second viewing, and when both viewings were combined (κ = 0.51, 0.51, and 0.51 respectively). Seventy-five percent (3 of 4) of reviewers had moderate intraobserver agreement for ulnar nerve subluxation classification, whereas 1 reviewer had substantial intraobserver classification (κ = 0.72). Overall, there was high confidence in 65% of classification scores in the second round of viewing, which improved from 58% in the first viewing round. When ulnar subluxation classification selections were regrouped into classes A/B or C/D, 100% of reviewers had substantial interobserver (κ = 0.74-0.75) and substantial to almost perfect intraobserver (κ = 0.71-0.91) agreement. CONCLUSIONS: The 4-category classification was reproducible within and between reviewers. Agreement appeared to increase when simplifying the classification to 2 categories, which may provide guidance to surgical decision making. The validation of a reproducible classification scheme for intraoperative ulnar subluxation may aid with decision making and further postoperative outcomes research.

Pyrocarbon humeral heads for hemishoulder arthroplasty grant satisfactory clinical scores with minimal glenoid erosion at 5-9 years of follow-up.

BACKGROUND: Hemishoulder arthroplasty (HSA) is a more conservative alternative to total shoulder arthroplasty for young and active patients with minimal glenoid erosion or deformity. Pyrocarbon humeral heads were introduced as an alternative to metallic humeral heads, which were associated with glenoid erosion in 28%-43%. The purpose of this study was to evaluate the progression of glenoid erosion and clinical scores of HSA using pyrocarbon humeral heads from short- (2-4 years) to midterm (5-9 years). METHODS: We retrieved the records of 45 consecutive patients who underwent HSA with pyrocarbon humeral heads from 2013 to 2017. Patients were evaluated radiographically and clinically at a first follow-up (2-4 years) and a second follow-up (5-9 years). Preoperative glenoid morphology was assessed using computed tomography scans, and glenoid erosion was assessed using plain radiographs according to Sperling et al. The Constant score (CS), American Shoulder and Elbow Surgeons (ASES) score, and Subjective Shoulder Value (SSV) score were assessed by an independent observer. RESULTS: From the initial cohort of 45 patients, 2 underwent revision surgery (4.4%) due to persistent pain (without signs of rotator cuff pathology or glenoid erosion) and 6 were lost to follow-up (13%), leaving 37 for outcome assessment (82%). At the first follow-up of 2.2 ± 0.4 years, all clinical scores improved substantially (CS from 29.3 ± 13.5 to 76.7 ± 14.4, ASES from 23.7 ± 15.6 to 87.0 ± 16.0, and SSV from 25.3 ± 12.2 to 84.1 ± 15.2), and at the second follow-up of 6.2 ± 1.2 years, good clinical scores were maintained (CS from 76.7 ± 14.4 to 80.8 ± 16.0, ASES from 87.0 ± 16.0 to 92.3 ± 15.0, and SSV from 84.1 ± 15.2 to 82.8 ± 18.3). At the second follow-up, glenoid erosion was moderate in 9 (24%) and severe in 3 (8.1%). When comparing with immediate postoperative radiographs, 10 shoulders exhibited progression of glenoid erosion by 1 grade (n = 9) or 2 grades (n = 1). CONCLUSION: Pyrocarbon humeral heads for HSA grant satisfactory clinical scores with minimal glenoid erosion.

Functional and radiographic results of anatomic total shoulder arthroplasty in the setting of subscapularis dysfunction: 5-year outcomes analysis.

BACKGROUND: Subscapularis management is a critical component to the success of anatomic total shoulder arthroplasty (TSA). Failure to heal the subscapularis can result in pain, weakness, loss of function, and revision. However, not all patients have poor outcomes. The purpose of this study is to compare patients with normal and dysfunctional subscapularis function following TSA in regard to (1) patient-reported outcome measures (PROMs); (2) range of motion (ROM) and strength; (3) achievement of minimal clinically important differences (MCIDs); and (4) specific functional internal rotation tasks. METHODS: A retrospective review of patients treated with TSA for osteoarthritis with a minimum 2-year follow-up was performed to identify patients with subscapularis dysfunction. Subscapularis dysfunction was diagnosed when any degree of weakness in internal rotation was detected on physical examination (positive belly press sign). These patients were case controlled matched on a 1:3 ratio to patients with normal subscapularis function based on age and sex. PROMs, measured active motion, revision rates, patient satisfaction, and postoperative radiographic findings were compared. Population-specific institutional anchor-based MCID values were used to compare the improvement in PROM. RESULTS: Of the 668 patients included, 34 patients (5.1%) demonstrated evidence of subscapularis dysfunction. Mean follow-up for the normal subscapularis function cohort was 63.4 ± 29.7 and 58.7 ± 26.8 for the dysfunctional subscapularis cohort. Patients with subscapularis dysfunction demonstrated significantly worse postoperative Simple Shoulder Test, Single Assessment Numerical Evaluation, visual analog scale (VAS) function, VAS pain, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores with higher rates of unsatisfactory results when compared to patients with normal subscapularis function. Abduction, elevation, internal rotation ROM, along with supraspinatus and external rotation strength were also significantly worse in the dysfunctional group. Similarly, these patients were more likely to have decreased ability to perform functional internal rotation tasks, with only 47% of the patients being able to reach the small of their back compared to 85% with normal subscapularis function. Radiographically, the dysfunctional cohort demonstrated higher rates of anterior subluxation (56% vs. 7%; P < .001) and glenoid loosening (24% vs. 5%; P = .004). Similarly, revision rates were significantly higher for patients with subscapularis dysfunction (8 patients, 23.5%). Nonetheless, the dysfunctional subscapularis cohort demonstrated improvements in VAS pain (4.0 ± 3.7) and ASES (46.4 ± 35.9) scores that exceeded MCID thresholds. CONCLUSION: Patients who develop subscapularis dysfunction after TSA have significantly worse PROMs, ROM, functional tasks of internal rotation, and radiographic outcomes, as well as increased rates of revision. Although patients show worse outcomes and high revision rates compared with their normal-functioning counterparts, these patients maintained improvement above MCID thresholds for pain and function at a mean 5-year follow-up.

Three-dimensional evaluation of the transverse rotator cuff muscle's resultant force angle in relation to scapulohumeral subluxation and glenoid vault morphology in nonpathological shoulders.

BACKGROUND: Static posterior subluxation of the humeral head (SPSH) results in glenohumeral osteoarthritis. Treatment strategies for SPSH with or without resulting osteoarthritis remain challenging. There is growing interest in evaluating the rotator cuff muscle volume, fatty infiltration, or forces in osteoarthritic shoulders with SPSH, mainly due to a possible transverse force imbalance. In nonpathological shoulders, the transverse angle of the rotator cuff muscle's resultant force may be associated with scapulohumeral alignment and glenoid vault morphology, despite an assumed transverse force balance. The purpose of this study was to assess the transverse rotator cuff muscle's resultant force angle (TRFA) and its relationship with the scapulohumeral subluxation index (SHSI) and selected glenoid vault parameters using computer modeling. METHODS: Computed tomography scans of 55 trauma patients (age 31 ± 13 years, 36 males) with nonpathological shoulders were analyzed and all measurements performed in 3-dimension. We placed landmarks manually to determine the humeral head center and the rotator cuff tendon footprints. The contours of the rotator cuff muscle cross-sectional areas were automatically predicted in a plane perpendicular to the scapula. Each rotator cuff muscle was divided into virtual vector fibers with homogeneous density. The resultant force vector direction for each muscle, corresponding to the rotator cuff action line, was calculated by vectorially summing the normalized fiber vectors for each muscle, weighted by the muscle trophic ratio. The resultant force vector was projected on the axial plane, and its angle with the mediolateral scapular axis was used to determine TRFA. The SHSI according to Walch, glenoid version angle (GVA), glenoid anteroposterior offset angle (GOA), glenoid depth, glenoid width, and glenoid radius were also evaluated. RESULTS: The mean values for TRFA, SHSI, GVA, GOA, glenoid depth, glenoid width, and glenoid radius were 7.4 ± 4.5°, 54.3 ± 4.8%, -4.1 ± 4.4°, 5.1 ± 10.8°, 3.3 ± 0.6 mm, 20 ± 2 mm, and 33.6 ± 4.6 mm, respectively. The TRFA correlated strongly with SHSI (R = 0.731, P < .001) and GVA (R = 0.716, P < .001) and moderately with GOA (R = 0.663, P < .001). The SHSI was strongly negatively correlated with GVA (R = -0.813, P < .001) and moderately with GOA (R = -0.552, P < .001). The GVA correlated strongly with GOA (R = 0.768, P < .001). In contrast, TRFA, SHSI, GVA, and GOA did not correlate with glenoid depth, width, or radius. CONCLUSION: Despite an assumed balance in the transverse volume of the rotator cuff muscles in nonpathological shoulders, variations exist regarding the transverse resultant force depending on the SHSI, GVA, and GOA. In healthy/nonosteoarthritic shoulders, an increased glenoid retroversion is associated with a decreased anterior glenoid offset.

Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers.

BACKGROUND: Radiographic and physical examination findings of ulnar nerve instability have been recognized in overhead throwing athletes, despite the fact that some of these abnormalities may be asymptomatic and represent adaptive changes. While recommendations for screening and early detection have been made that can adversely impact an athletes' career, the presence of bilateral ulnar nerve subluxation and its relationship with medial elbow symptoms has not been characterized in professional overhead throwing athletes. PURPOSE: To characterize the prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers. METHODS: A cross-sectional observational analysis was conducted utilizing standardized ultrasonographic examinations of bilateral elbows in 91 consecutive professional baseball pitchers (median age, 22 years; range, 17-30 years). The relationship between ulnar nerve subluxation and ulnar nerve signs, symptoms, and provocative physical examination maneuvers was also investigated. RESULTS: The prevalence of bilateral ulnar nerve subluxation was 26.4% (95% CI, 17.7%-36.7%; 24 of the 91 athletes). Thirty-five athletes (38.5%; 95% CI, 28.4%-49.2%) had subluxation in at least 1 elbow. No athletes with subluxation had positive ulnar nerve signs, symptoms, or provocative tests. CONCLUSION: Ulnar nerve subluxation is common among professional pitchers, and is more often than not bilateral. In this population of athletes, ulnar nerve subluxation does not appear to be associated with pathological findings.

Anatomic total shoulder arthroplasty for B2 glenoids treated with asymmetric reaming has equivalent survivorship and patient outcomes compared with type A glenoids at a mean 9-year follow-up.

BACKGROUND: Walch B2 glenoids can present a challenge to shoulder arthroplasty surgeons. Short-term studies have demonstrated that corrective reaming to 10° of retroversion in anatomic total shoulder arthroplasty (aTSA) can result in good outcomes; however, there is little data reporting the long-term outcomes in this cohort. B2 glenoids treated with high-side reaming present a theoretical risk of early glenoid component failure as one may ream into the subchondral bone. This study aimed to demonstrate that (1) B2 glenoids treated with corrective reaming have durable results and (2) offer similar results to Walch A1/2 in long-term follow-up. METHODS: Patients who underwent aTSA by a single surgeon (E.L.F.) were identified from a shoulder arthroplasty registry. Inclusion criteria included Walch A1, A2, or B2 glenoid; a diagnosis of primary shoulder osteoarthritis; and a minimum radiographic and clinical follow-up of 5 years. Forty-three patients with B2 glenoids were compared to a cohort of 42 patients with A1 or A2 glenoids. Preoperative computed tomography (CT) and radiographs were used to assess deformity, glenoid version, and posterior subluxation of the humeral head. Postoperatively, patients were assessed with radiographs and patient-reported outcome measures including American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Simple Shoulder Test (SST) score, and visual analog scale (VAS). RESULTS: Eighty-five shoulders (82 patients, 42 B2 and 43 A1/A2 glenoids) with an average follow-up of 9.4 years were included. In the B2 cohort, the average retroversion was 21.1° and posterior subluxation was 69.4% compared with 10.6° (P < .001) and 57.5% (P < .001), respectively, in the A1 or A2 cohort. The cohort demographics were similar except for male sex (B2 69.8% vs. A1 or A2 37.2%, P = .008). There was no difference between the cohorts in their improvement in ASES (P = .807), SST (P = .586), and VAS (P = .930) scores. There was no difference in lateral humeral offset (P = .889) or acromial humeral interval (P = .468) between initial postoperative and final follow-up visits. Survivorship for B2 glenoids was 97.6%, 94.1%, and 73.3% at 5, 10, and 15 years, respectively, compared with 97.6%, 91.9%, and 83.5% in type A glenoids. The revision rate was similar between the 2 groups (P = .432). Lazarus score (P = .682) and rates of humeral radiolucency (P = .366) and humeral osteolysis (P = .194) were similar between the 2 cohorts at final follow-up. CONCLUSION: Asymmetric reaming of patients with B2 glenoids is a reliable method of glenoid preparation with excellent mid- to long-term clinical results, patient-reported outcomes, and low revision rates similar to their A1 and A2 counterparts.

Latarjet procedure restores range of motion at six months postoperatively: a prospective cohort study utilizing motion capture analysis.

BACKGROUND: There is a common concern that range of motion (ROM) is negatively affected by the Latarjet procedure. We hypothesize that the Latarjet procedure results in full recuperation of ROM postoperatively and significantly improved patient reported outcome measures. METHODS: Patient data were prospectively collected from a randomized controlled trial to analyze outcomes after open Latarjet procedure. Inclusion criteria involved a minimum follow-up of six months and unilateral shoulder instability. Study outcome was assessed by postoperative ROM at six months postoperatively and compared to the preoperative ROM of the ipsilateral shoulder as well as the ROM of the unaffected contralateral shoulder. All ROM measurements were performed utilizing a motion capture system to ensure consistent and reliable measurements. RESULTS: The study included a total of 84 patients. ROM was measured in external rotation with the shoulder adducted (ER1), external rotation with the shoulder abducted 90 degrees (ER2), internal rotation with the arm abducted 90 degrees (IR2), and active forward elevation (AE). The average difference in ROM between the operated arm vs. the contralateral healthy arm at six months postoperatively was 3.4 degrees in ER1 (p=0.19), 4.2 degrees in ER2 (p=0.086), 2.2 degrees in IR2 (p=0.36), and 2.4 degrees in AE (p=0.045). Sub-analysis of patients with and without sling use revealed no significant difference in ROM between the operated shoulder and contralateral shoulder at six months in either group, with the exception of ER2 in the sling group. In this latter group, ROM was 71 degrees in the operated arm and 79 degrees in the contralateral arm (p=0.0094). Average preoperative pain score was 25.7 (21.4-30.1, 95%CI) vs. 13.0 postoperatively at six months (9.50-16.5, 95%CI) (p <0.00001). Average preoperative SANE instability was 42.9 (38.4-47.3, 95%CI) vs. 86.2 postoperatively at six months (83.6-88.7, 95%CI) (p <0.00001). Average preoperative Rowe score was 38.5 (34.3-42.7, 95%CI) vs. 84.3 at six postoperative months (81.1-87.4, 95%CI) (p<0.00001). CONCLUSIONS: Latarjet procedure performed for anterior instability utilizing a capsular repair result in complete ROM recovery in ER1, ER2, and IR2 at six months postoperatively, with only a slight discrepancy in active elevation. Sling use after the Latarjet procedure results in no benefit over postoperative recovery without the use of a sling. Sling use negatively affects the ROM in ER2, taking as reference the contralateral arm of the same patient, when compared to patients that did not use a sling postoperatively.

Retrospective analysis of atlantoaxial rotatory fixation describing age distribution and gender ratio in children and adolescents: A preliminary report.

INTRODUCTION: Atlantoaxial rotatory fixation (AARF) in children presents with an acute onset of neck pain. Almost all cases heal within a few days of onset and are treated conservatively. Because few cases of AARF have been reported, the age distribution or gender ratio of AARF in the child population have not been described enough. In Japan, the social insurance system covers all citizens. Thus, we used insurance claims data to investigate the features of AARF. The aim of this study is to examine the age distribution, compare gender ratio and determine the recurrence proportion of AARF. METHODS: We used the JMDC database to search for claims data submitted between January 2005 and June 2017 for cases of AARF in patients aged <20 years. RESULTS: We identified 1949 patients with AARF, of which 1102 (56.5%) were male. The mean age was 98.3 ± 42.2 months and 91.6 ± 38.4 months in males and females, respectively, and males with AARF were significantly older at onset than females with AARF (p < 0.001). In both sexes, the highest frequency of AARF occurred when the patient was 6 years old. There were 121 (6.2%) cases of recurrent AARF (male: 61, 5.5%; female: 60, 7.1%), but the age differences between the sexes in these cases were not statistically significant. CONCLUSIONS: This is the first report to describe the characteristics of the study population of AARF. Males were more likely to suffer from AARF than females. Furthermore, age (in months) at AARF onset was significantly higher in males than in females. Recurrence rate was not significant in both sexes.

Anterior radial head subluxation in primary elbow osteoarthritis.

PURPOSE: To investigate elbows with primary osteoarthritis (OA) for the presence of anterior radial head subluxation. METHODS: A total of 71 patients with elbow osteoarthritis and 45 with lateral epicondylitis were initially identified. The baseline characteristics and preoperative elbow X-rays of consecutive patients that had been clinically confirmed with elbow OA or lateral epicondylitis between March 2011 and January 2020 were then retrospectively reviewed. The radiocapitellar ratio (RCR; the ratio of the displacement of the radial head about the diameter of the capitulum) was calculated using lateral views. These RCR values were compared between the OA and lateral epicondylitis cases. RESULT: A significant increase was detected in RCR values between patients in elbow OA and the control group (13.2% (± 10.6) vs -1.2% (± 6.8), P<0.001). Based on receiver operating characteristic curves, RCR values had an excellent area under the curve (0.89) for the detection of elbow OA (Youden index, 0.69; sensitivity, 89%; specificity, 80%). Based on the ROC curve, the cutoff value of RCR was 0.04. Patients with RCR ≥ 0.04 had a significantly higher proportion of cases with elbow OA (risk ratio, 31.50 [95% CI, 11.17-88.82]) than those with RCR ˂ 0.04 (P ˂ 0.001). CONCLUSION: Radial head subluxation is a radiographic finding associated with elbow OA and RCR ≥ 0.04 could be used as an aetiological factor for elbow OA diagnosis.

A new etiology of nontraumatic C0-C1-C2-Complex instability - abnormality of musculus rectus capitis posterior minor: a case report.

PURPOSE: This study presents an abnormality of the musculus rectus capitis posterior minor (RCPmi) as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex, with a focus on identifying the absence or atrophy of RCPmi on both sides. METHODS: A 36-year-old male patient presented with recurring neck pain (VAS 8/10) and tingling paresthesia in the entire left hand over a six-month period, without significant neurological deficits. Radiated arm pain was not reported. Imaging examinations revealed sagittal plane instability in the C0-C1-C2-complex, spinal canal stenosis (SCS), and myelopathy at the C1 level. Subsequently, a dorsal C0-1 reposition and fusion with laminectomy were performed. RESULTS: The congenital absence or atrophy of RCPmi, leading to the lack of cephalad-rearward traction on the C1-tuberculum-posterius, induced a developmental failure of the C1 posterior arch. Consequently, the oblate-shaped C1 posterior arch lost support from the underlying C2 posterior arch and the necessary cephalad-rearward traction throughout the patient's 36-year life. This gradual loss of support and traction caused the C1 posterior arch to shift gradually to the anterior side of the C2 posterior arch, resulting in a rotational subluxation centered on the C0/1 joints in the sagittal plane. Ultimately, this led to SCS and myelopathy. Traumatic factors were ruled out from birth to the present, and typical degenerative changes were not found in the upper cervical spine, neck muscles, and ligaments. CONCLUSION: In this case, we not only report the atrophy or absence of RCPmi as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex but also discovered a new function of RCPmi. The cephalad-rearward traction exerted by RCPmi on the C1 posterior arch is essential for the development of a normal C1 anterior-posterior diameter.

Reliability and head-loading effects in imaging diagnosis of vertical subluxation in patients with rheumatoid arthritis.

OBJECTIVES: The purpose of this study was to examine the reproducibility of vertical subluxation (VS) parameters using X-ray, computed tomography (CT), and tomosynthesis (TS) while comparing the head-loading effects. METHODS: The VS parameters of 26 patients (retrospective review) were evaluated. Using the intra-class correlation coefficient, we statistically examined the intra-rater and inter-rater reliabilities of the parameters. Head-loaded and -unloaded imagings were compared using a Wilcoxon signed-rank test. RESULTS: The intra-rater reliability of TS and CT showed intra-class correlation coefficients of ≥0.8 (X-ray range: 0.6-0.8), with similar results for the inter-rater reliabilities. Furthermore, in head-loading imaging, the TS had significantly higher VS scores than that of CT (P < .05). CONCLUSIONS: In comparison with the X-ray, TS and CT were more accurate and reproducible. In terms of head loading, the VS values for TS were worse than those for CT, indicating that TS was more effective than CT in diagnosing VS.

Zonular fibre Insertion-to-Limbus Distance (ZLD): normative data to assess lens position and diagnose ectopia lentis.

PURPOSE: Subluxation of the crystalline lens (Ectopia Lentis, EL) can lead to significant visual impairment and serves as a diagnostic criterion for genetic disorders such as the Marfan syndrome. There is no established criterion to diagnose and quantify EL. We prospectively investigated the distance between the zonular fibre insertion and the limbus (ZLD) in healthy subjects as a parameter to assess the position of the lens, quantify EL and provide normative data. METHODS: This prospective, observational, cross-sectional study includes one-hundred-fifty eyes of 150 healthy participants (mean age 28 years, range 4-68). Pupils were dilated with tropicamide 0.5% and phenylephrine 2.5% eyedrops. ZLD was measured in mydriasis at the slit lamp as the distance between the most central visible insertions of the zonular fibres on the lens surface and the corneoscleral limbus. Vertical pupil diameter (PD) and refractive error were recorded. If zonular fibre insertions were not visible, the distance between limbus and the pupillary margin was recorded as ZLD. RESULTS: 145 right and 5 left eyes were examined. 93% of study subjects were Caucasian, 7% were Asian. In eyes with visible zonular fibre insertions (n = 76 eyes), ZLD was 1.30 ± 0.28 mm (mean ± SD, range 0.7-2.1) and PD was 8.79 ± 0.57 mm (7.5-9.8). In the remaining 74 eyes, ZLD was 1.38 ± 0.28 mm (0.7-2.1), and PD was 8.13 ± 0.58 mm (6.7-9.4). For all eyes, ZLD was 1.34 ± 0.29 mm (0.7-2.1), and PD was 8.47 ± 0.66 mm (6.7-9.8). Refractive error and sex did not significantly affect ZLD. Smaller PD and older age were associated with larger ZLD (P < 0.001 and P = 0.036, respectively). CONCLUSION: Average ZLD was 1.34 mm in eyes of healthy subjects. Older age correlated with larger ZLD. These normative data will aid in diagnosing and quantifying EL.