Location and Size of the Reverse Hill-Sachs Lesion in Patients with Traumatic Posterior Shoulder Instability.

BACKGROUND: In patients with traumatic posterior shoulder instability, little is known about the precise location and size of the reverse Hill-Sachs lesion. METHODS: Forty-nine shoulders of 47 patients with traumatic posterior instability were included in this study based on the following inclusion criteria: 1) a primary or recurrent traumatic posterior shoulder dislocation, and 2) the initial event was caused by trauma. Patients were excluded if they had: 1) no history of trauma, 2) prior shoulder surgery, 3) no CT examination, or 4) seizure cases. Three-dimensional images of the humerus reconstructed from CT images were reviewed using an image analysis software. The location and size of the reverse Hill-Sachs lesion were measured and described on a clock face on the humeral head. RESULTS: The reverse Hill-Sachs lesion was observed in 25 of 49 shoulders (51%). The reverse Hill-Sachs lesions were located between 1:37 and 2:48. The depth of the reverse Hill-Sachs lesion (mean ± SD) was 5.8 ± 2.2 mm. The extent of the reverse Hill-Sachs lesion was 35° ± 12°. The average orientation of the reverse Hill-Sachs lesion, represented by an angle measured from the 12 o'clock position, was 64° ± 12° and pointing towards 2:09 on a clock face. Length and width of reverse Hill-Sachs lesions were 9.7 ± 4.7 mm, 11.1 ± 3.6 mm, respectively. CONCLUSION: The reverse Hill-Sachs lesion was a semicircular compression fracture located on the anteromedial aspect of the humeral head. Compared with shoulders with anterior shoulder instability, the humeral defect was smaller and located more inferiorly in shoulders with posterior instability.

Statistical shape models that predict native glenoid width based on glenoid height are inaccurate in their current form: a cross-sectional study.

BACKGROUND: The extent of measurement errors of statistical shape models that predict native glenoid width based on glenoid height to subsequently determine the amount of anterior glenoid bone loss is unclear. Therefore, the aim of this study was to (1) create a statistical shape model based on glenoid height and width measured on 3-dimensional computed tomography (3D-CT) and determine the accuracy through measurement errors and (2) determine measurement errors of existing 3D-CT statistical shape models. MATERIALS AND METHODS: A retrospective cross-sectional study included all consecutive patients who underwent CT imaging before undergoing primary surgical treatment of traumatic anterior shoulder dislocation between 2007 and 2022 at the Tohoku University Hospital and affiliated hospitals. Patients were included when instability was unilateral and CT scans of both the injured and contralateral uninjured shoulder were available. 3D segmentations were created and glenoid height and width of the injured and contralateral uninjured side (gold standard) were measured. Accuracy was determined through measurement errors, which were defined as a percentage error deviation from native glenoid width (contralateral uninjured glenoid), calculated as follows: measurement error = [(estimated glenoid width with a statistical shape model - native glenoid width) / native glenoid width] × 100%. A linear regression analysis was performed to create a statistical shape model based on glenoid height according to the formula: native glenoid width = a × glenoid height + b. RESULTS: The diagnosis and procedure codes identified 105 patients, of which 69 (66%) were eligible for inclusion. Glenoid height demonstrated a very strong correlation (r = 0.80) with native glenoid width. The linear regression formula based on this cohort was as follows: native glenoid width = 0.75 × glenoid height - 0.61, and it demonstrated an absolute average measurement error of 5% ± 4%. The formulas by Giles et al, Chen et al and Rayes et al demonstrated absolute average measurement errors of 10% ± 7%, 6% ± 5%, and 9% ± 6%, respectively. CONCLUSION: Statistical shape models that estimate native glenoid width based on glenoid height demonstrate unacceptable measurement errors, despite a high correlation. Therefore, great caution is advised when using these models to determine glenoid bone loss percentage. To minimize errors caused by morphologic differences, preference goes to methods that use the contralateral side as reference.

When and how much does the muscle strength recover after arthroscopic superior capsular reconstruction?

BACKGROUND: Recently, arthroscopic superior capsular reconstruction (SCR) has been performed for irreparable large to massive rotator cuff tears and excellent clinical results have been reported. Although the muscle strength is reported to recover, it has not yet been clarified when and how much it recovers. The purpose of this study was to determine the recovery pattern of muscle strength after SCR. METHODS: We retrospectively reviewed 35 patients (mean age, 65 years) who met the following inclusion criteria: (1) patients with large to massive irreparable tears of the rotator cuff including the supraspinatus and infraspinatus tendons; (2) those with severe muscle atrophy and fatty change; (3) those who underwent assessment of muscle quality and strength by magnetic resonance imaging and dynamometry at 6 months, 1 year, and 2 years; (4) those with a minimum follow-up period of 2 years; and (5) those without severe osteoarthritis. The isometric muscle strength of scaption (ie, scapular-plane elevation), internal rotation, and external rotation in adduction was measured twice for each motion by a dynamometer. RESULTS: Relative to the muscle strength on the uninvolved side, the involved side showed 61% ± 21% in scaption, 63% ± 20% in external rotation, and 103% ± 29% in internal rotation at 2 years after surgery. Whereas no significant differences were observed between the 1-year and 2-year follow-up assessments, a significant difference in muscle strength of scaption was found between 6 months and 1 year (P = .0174). Graft retear was seen in 5 cases (14%). There was a trend that the muscle strength of scaption and external rotation in the no-retear group was greater than that in the retear group despite no significant difference (P = .0717 and P = .0824, respectively). CONCLUSION: The recovery of the muscle strength after SCR was observed until 1 year after surgery, and the muscle strength of scaption and external rotation returned to 60% of that on the uninvolved side at 2 years.

A survey and biomechanical analysis of the feasibility of the thumb test for determining the cancellous bone quality for stemless shoulder prosthesis.

BACKGROUND: The effect of the thumb test for assessing the cancellous bone quality at the resection plane of the proximal humerus on determining the application of a stemless shoulder prosthesis remains unclear. This study was conducted to survey the current utilization of the thumb test among surgeons and to investigate biomechanical features of the thumb test. METHOD: A survey among shoulder surgeons who had experience with stemless prostheses was conducted to investigate the current utilization of preoperative assessments and intraoperative thumb test when applying stemless prosthesis. Biomechanical experiments for the thumb test using artificial bone models were performed to assess the compression force, contact pressure and area. According to the preliminary survey, three compression techniques were assessed: compression perpendicular to the surface with thumb pad (P-pad technique) or tip of the thumb (P-tip technique), or compression in the vertical direction simulating compression along the longitudinal axis of the humeral shaft with tip-pad of the thumb (H-axis technique). The contact area was separated into three subregions (proximal, middle and distal) to assess the distribution of contact pressure. RESULTS: Among 38 surgeons, 66% utilized the thumb test intraoperatively. The P-pad technique was more frequently applied than the P-tip or H-axis techniques (80%, 4% and 16%, respectively). Although with wide variation among the examiners, biomechanical assessments revealed the P-pad technique showed larger contact area and less compression force than the P-tip technique. The P-pad technique provided no significant localized differences in the mean contact pressure on the compressed plane, whereas the P-tip and H-axis techniques showed significant differences among subregions. CONCLUSION: This survey demonstrated relatively frequent application of the thumb test on applying the stemless shoulder prosthesis. Biomechanical assessment revealed the thumb test can hinder objective reproducibility among examiners; therefore, further investigations to identify feasible assessments of the bone quality is required.

A stabilizing role of the glenoid labrum: the suction cup effect.

BACKGROUND: The glenoid labrum acts as a bumper, deepening glenoid concavity and amplifying the concavity-compression mechanism, and serves as the scapular attachment for glenohumeral ligaments. The role of the posterosuperior labrum in anteroinferior glenohumeral stability, and the role of the anterior labrum in posterior stability has been debated. The purpose of this study was to quantify the contribution of anteroinferior and posterosuperior labral tears to loss of glenohumeral stability in multiple directions. METHODS: Fourteen fresh-frozen cadaveric shoulders were tested on a custom stability ratio measurement apparatus. The peak force that was required to translate the humeral head in anterior, anteroinferior, posterior, and posteroinferior directions was measured under 5 conditions: intact labrum (n = 14), anteroinferior labral tear (n = 7), posterosuperior labral tear (n = 7), combined labral tear (n = 14), and no labrum (n = 14). The stability ratio was defined as the peak translational force divided by the compressive force. Within force-translation curves, we defined the suction cup effect as the force required to release the negative pressure created by an intact labrum. RESULTS: The suction cup effect was usually present with the intact labrum and always disappeared after removal of the labrum for anterior (100% vs. 0%) and posterior (86% vs. 0%) translations (P < .001). After creation of an anteroinferior labral tear, the stability ratio for posterior direction decreased (P < .001) and the suction cup effect disappeared (P < .001). After creation of a posterosuperior labral tear, stability ratios in the anterior and anteroinferior directions decreased (P ≤ .006) and the suction cup effect disappeared (P ≤ .015). The stability ratio for anterior and anteroinferior testing was more diminished by posterosuperior labral tears than anteroinferior labral tears, and the stability ratio for posterior testing was more diminished by anteroinferior labral tears than posterosuperior labral tears. CONCLUSION: Anteroinferior labral tears decreased posterior stability and posterosuperior labral tears decreased anterior and anteroinferior stability, largely because of loss of the suction cup effect.

How much force is acting on the shoulder joint to create a Hill-Sachs Lesion or reverse Hill-Sachs Lesion?

BACKGROUND: It has not been clarified yet how much force is acting on the shoulder joint to create Hill-Sachs/reverse Hill-Sachs lesions which are commonly observed in patients with anterior or posterior shoulder instability. The purpose of this study was to determine the magnitude of force to create these bony lesions using cadaveric shoulders. METHODS: Fourteen fresh-frozen cadaveric shoulders were used. Compression tests were performed using the universal testing machine. The specimens were randomly divided into two groups. In group A, the posterior humeral head (the bare area and articular cartilage) was first compressed against the anterior glenoid rim to simulate a Hill-Sachs lesion, followed by the anterior humeral head being compressed against the posterior glenoid rim. In group B, the same procedure was repeated in the reverse order. X-ray microcomputed tomography (microCT) was also performed. RESULTS: The maximum compression force to create a Hill-Sachs lesion was 771 ± 214 N (mean ± SD) on the articular cartilage of the posterior humeral head, which was significantly greater than the force of 447 ± 215 N to create it on the bare area (P = 0.0086). Regarding the reverse Hill-Sachs lesions, the maximum compression force was 840 ± 198 N when it was created on the articular cartilage of the anterior humeral head, which was significantly greater than the force of 471 ± 100 N when it was created at the footprint of the subscapularis tendon (P = 0.0238). MicroCT showed multiple breakage of the trabecular bone. CONCLUSION: A force to create a Hill-Sachs lesion or a reverse Hill-Sachs lesion was significantly greater when it was created on the humeral articular cartilage than at the non-cartilage area. Also, the force to create a reverse Hill-Sachs lesion was significantly greater than the one to create a Hill-Sachs lesion.

Effect of Anterior Glenoid Chondrolabral Defects on Anterior Glenohumeral Stability: A Biomechanical Study.

Background: It is well known that glenoid osseous defects >13.5% of the glenoid width critically destabilize the shoulder, as do labral tears. Chondrolabral defects often occur with anterior dislocation of the shoulder. It is unclear whether glenoid chondrolabral defects contribute to shoulder stability and, if so, at what size they become critical. Purpose/Hypothesis: The purpose of this study was to determine the effect of incremental chondrolabral defect sizes on anterior shoulder stability in the setting of labral deficiency. The hypothesis was that chondrolabral defects ≥13.5% of the glenoid width will decrease anterior shoulder stability. Study Design: Controlled laboratory study. Methods: This controlled laboratory study tested 12 fresh-frozen shoulders. Specimens were attached to a custom testing device in abduction and neutral rotation with 50-N compression applied to the glenoid. The humeral head was translated 10 mm anterior, anteroinferior, and anterosuperior with the conditions of intact cartilage and labrum and anterior full-thickness chondrolabral defects of 3-, 6-, and 9-mm width. Translation force was measured continuously. Peak translation force divided by 50-N compressive force defined the stability ratio. Data were analyzed using analysis of variance. Results: The anterior stability ratio decreased between the intact state (36% ± 7%) and all defects ≥3 mm (≤32% ± 8%; P ≤ .023). The anteroinferior stability ratio decreased between the intact state (52% ± 7%) and all defects ≥3 mm (≤47% ± 7%; P ≤ .006). The anterosuperior stability ratio decreased between the intact state (36% ± 4%) and all defects ≥6 mm (≤33% ± 4%; P ≤ .006). A 3-mm defect equated to 10% of the glenoid width. There were moderate to strong negative correlations between chondrolabral defect size and stability ratio in the anterior, anteroinferior, and anterosuperior directions (r = -0.79, -0.63, and -0.58, respectively; P ≤ .001). There were moderate to strong negative correlations between the percentage of glenoid chondrolabral defect size to the glenoid width and the stability percentage in all directions (r = -0.81, -0.63, and -0.61; P ≤ .001). Conclusion: An anterior glenoid chondrolabral defect ≥3 mm (>10% of the glenoid width) significantly decreased anterior and anteroinferior stability. Chondrolabral defect size negatively correlated with stability. Clinical Relevance: To fully restore glenohumeral stability, in addition to labral repair, it may be necessary to reconstruct chondrolabral defects as small as 3 mm (10% of the glenoid width).

Morphology of Glenoid Cartilage Defects in Anteroinferior Glenohumeral Instability.

Background: Glenoid cartilage defects may contribute to anterior shoulder instability recurrence and progression to osteoarthritis, but their morphology remains unknown. Purpose/Hypothesis: The purpose was to determine the shape, size, and location of glenoid cartilage defects and the prevalence and risk factors for cartilage defects in the setting of anterior glenohumeral instability. It was hypothesized that glenoid cartilage defects would be common, would be associated with recurrence of dislocation, and would share similar morphology with glenoid osseous defects. Study Design: Cross-sectional study; Level of evidence, 3. Methods: In this retrospective study, all patients who underwent arthroscopic surgical treatment for anterior glenohumeral instability between January 2012 and May 2019 were included; excluded were patients with documented posterior or multidirectional instability or previous glenohumeral surgery. For each patient, the operative report, arthroscopic images, and preoperative magnetic resonance imaging (MRI) scans were reviewed to determine the prevalence of cartilage injury. For those patients with an Outerbridge grade 3 or 4 defect, the cartilage surfaces on the MRI scans were segmented to make 3-dimensional (3-D) segmentations. From these 3-D segmentations, we measured length, width, and surface area of the glenoid and defect, and the orientation of the defect relative to the superior and inferior poles of the glenoid. A multivariable analysis was conducted to determine correlates with cartilage damage. Results: In 322 patients treated operatively for anterior glenohumeral instability, 38% had a concomitant cartilage defect. The mean cartilage defect was located directly anteriorly at the 3:07 clockface position (range, 2:10-4:05) and encompassed 6.5% ± 3.5% of the glenoid surface area. However, defects ranged up to >56% of glenoid length and up to 27% of glenoid width, and the largest defect encompassed 19.5% of the glenoid cartilage surface area. Patients with a cartilage defect were more likely to be male (P = .031) and to have undergone a concomitant posterior labral repair (P = .018). Conclusion: Cartilage defects were common in patients with operatively treated anterior glenohumeral instability, occurring in 38% of patients. These defects were located directly anteriorly at 3:07, similar to osseous glenoid defects. Future prospective studies with cartilage-specific MRI sequences should be conducted.

Prognostic significance of extent of venous tumor thrombus in patients with non-metastatic renal cell carcinoma: Results from a Canadian multi-institutional collaborative.

PURPOSE: The prognostic significance of level of venous tumor thrombus (VTT) extension in patients with non-metastatic renal cell carcinoma (RCC) has been controversial. The aim of this study was to examine the prognostic significance of VTT extent in patients who underwent surgery for non-metastatic RCC. MATERIALS AND METHODS: The Canadian Kidney Cancer information system database was used to identify patients who underwent surgery for non-metastatic RCC and VTT from January 2011 to December 2019. Association between VTT level and recurrence-free survival (RFS), cancer-specific survival (CSS) and overall survival (OS) was examined. Univariable and multivariable analyses were performed to estimate predictors of survival. RESULTS: Out of 6,340 patients during the study period, 228 patients (3.6%) had VTT. VTT was level 0 in 84 (37%), level I to II in 112 (49%), and level III to IV in 33 (14%) patients as per the Mayo Clinic classification. Median age was 65.4 years (interquartile range [IQR] 57.6-72.2) and 169 (74.1%) were male. After a median follow-up of 21.2 months, VTT level did not significantly impact the RFS, CSS, or OS. For VTT level 0, I to II, and III to IV, there was no significant difference in estimated 5-year RFS (31%, 23%, and 30.5%; P > 0.05), CSS (70%, 69%, and 55%; P > 0.05) and OS (64%, 66%, and 50%; P > 0.05). Adjusting for known prognostic factors, thrombus level was not associated with risk of recurrence or death. CONCLUSION: In a large, multi-institutional cohort of patients undergoing surgery for non-metastatic RCC with tumor thrombus, thrombus extent was not independently associated with recurrence or death.

Acromial and glenoid morphology in glenohumeral osteoarthritis: a three-dimensional analysis.

BACKGROUND: The purpose of this study was to determine the association between glenohumeral osteoarthritis (GHOA) and three-dimensional acromial and glenoid morphology. METHODS: In this retrospective study, we compared computed tomographic studies of three groups of scapulae: normal healthy, mild GHOA (Samilson-Prieto grade 1), and severe GHOA (Samilson-Prieto grade 3). All scans were segmented to create three-dimensional reconstructions. From these models, critical shoulder angle and acromial offset were measured, as normalized to scapular height. The coronal plane inclination of the glenoid was measured using a glenoid sphere-fit method. Reliability was confirmed via intraclass correlation coefficients > 0.75. RESULTS: Eighty scapulae were included: 30 normal, 20 mild GHOA, and 30 severe GHOA. There were no differences in acromial offset between the normal group and either the mild-GHOA group or the severe-GHOA group. The severe-GHOA group had a smaller critical shoulder angle than either the normal (30 ± 5° vs. 34 ± 4°, P = .003) or mild-GHOA groups (34 ± 4°, P = .020), but the normal and mild-GHOA groups did not differ (P = .965). The severe-GHOA group had more inferiorly inclined glenoids than either the normal (7 ± 6° vs. 12 ± 5°, P = .002) or mild-GHOA groups (14 ± 5°, P ≤ .001), but the normal and mild-GHOA groups did not differ (P = .281). CONCLUSION: Normal and severe-GHOA shoulders differ in critical shoulder angle and glenoid inclination but not acromial offset. The lack of a difference in critical shoulder angle or inferior inclination between mild-GHOA and normal groups calls into question whether inclination and critical shoulder angle differences predate severe GHOA.

Footprint size matters: wider coronal greater tuberosity width is associated with increased rates of healing after rotator cuff repair.

BACKGROUND: The purpose of this study was to determine whether greater tuberosity morphology (1) could be measured reliably on magnetic resonance imaging (MRI), (2) differed between patients with rotator cuff tears (RCTs) compared with those without tears or glenohumeral osteoarthritis, or (3) differed between patients with rotator cuff repairs (RCR) who healed and those that did not. METHODS: This is a retrospective comparative study. (1) We measured greater tuberosity width (coronal and sagittal), lateral offset, and angle on MRI corrected into the plane of the humerus. To determine reliability, these measurements were made by two observers and intraclass correlation coefficients were calculated. (2) We compared these measurements between patients with a full-thickness RCT and patients aged >50 years without evidence of a RCT or glenohumeral osteoarthritis. (3) We then compared these measurements between those patients with healed RCRs and those with evidence of retear on MRI. In this portion, we only included patients with both a preoperative and postoperative MRI at least 1 year from RCR. Postoperative MRIs were obtained to assess healing rates, not because of concern for failure. Those without tendon defects were considered healed. RESULTS: (1) In a validation cohort of 50 patients with MRI, all inter-rater intraclass correlation coefficients were greater than 0.75. (2) There were no differences between our RCT group of 110 patients and our comparison group of 100 patients in tuberosity coronal width, sagittal width, or lateral offset. The RCT group had a significantly smaller greater tuberosity angle (63 ± 4° vs 65 ± 5°, P = .003). (3) In our group of 110 RCRs, postoperative MRI scans were obtained at a mean follow-up of 23.6 ± 15.7 months showing 84 (76%) patients had healed RCRs. Larger coronal tuberosity width was associated with healing (1.3 ± 0.2 vs 1.2 ± 0.2 cm, P = .032), as was smaller tear width (P < .001), and retraction (P < .001). When coronal width was dichotomized, there was a significantly higher healing rate with a width over 1.2 cm (85 vs 66%, P = .02). No other greater tuberosity morphological characteristics were associated with RCR or postoperative healing. CONCLUSION: RCTs do not appear to be associated with greater tuberosity morphology. Postoperative rotator cuff healing based on MRI is 76%. Higher rates of healing occur with a wider coronal tuberosity width (ie, rotator cuff tendon footprint). Consideration could be given to widening the footprint intraoperatively in an effort to improve healing rates although this remains to be validated.

Surgical Management of Superior Labral Tears in Athletes: Focus on Biceps Tenodesis.

Superior labrum anterior-posterior (SLAP) lesions are common in overhead athletes. Though some patients have asymptomatic lesions, many tears cause pain and diminished athletic performance. Accurate diagnosis of SLAP lesions can be challenging as the sensitivity and specificity of both the physical exam and advanced imaging is questionable. Management is also difficult, as treatment can be life-altering or career-ending for many athletes. If first-line nonoperative treatment fails, surgical options may be considered. The optimal surgical management of SLAP lesions in athletes is debated. Historically, return to play (RTP) rates among athletes who have undergone arthroscopic SLAP repair have been unsatisfactory, prompting clinicians to seek alternate surgical options. Biceps tenodesis (BT) has been postulated to eliminate biceps tendon-related pain in the shoulder and is increasingly used as a primary procedure for SLAP lesions. The purpose of this text is to review the current literature on the surgical management of SLAP lesions in athletes with an emphasis on the role of BT.

Lymph node dissection during radical nephrectomy: A Canadian multi-institutional analysis.

OBJECTIVES: To determine the association between lymph node dissection (LND) at the time of radical nephrectomy and survival in a large, multi-institutional cohort using a propensity score matching design. SUBJECTS AND METHODS: The Canadian Kidney Cancer information system was used to identify patients undergoing radical nephrectomy for nonmetastatic renal cell carcinoma. Associations between LND with overall survival , recurrence free survival and cancer specific survival were determined using various propensity score techniques in the overall cohort and in patients with varying probabilities of pN1. Cox models were used to determine association of lymph node removed with outcomes. RESULTS: Of the 2,699 eligible patients, 812 (30%) underwent LND. Of the LND patients, 88 (10.8%) had nodal metastases. There was no association between LND and improved overall survival, recurrence free survival or cancer specific survival using various propensity score techniques (stratification by propensity score quintile, matched pairs, inverse treatment probability weighting and adjusted for propensity score quintile). There was no association between LND and a therapeutic benefit in patients with increased threshold probabilities of nodal metastases. Increased number of lymph nodes removed was not associated with improved survival outcomes. CONCLUSIONS: LND at the time of radical nephrectomy for renal cell carcinoma is not associated with improved outcomes. There was no benefit in patients at high risk for nodal metastases, and the number of nodes removed did not correlate with survival. Further studies are needed to determine which high risk patients may benefit from LND.

Rheumatoid arthritis is associated with increased symptomatic acromial and scapular spine stress fracture after reverse total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to determine factors associated with early symptomatic acromial and scapular spine fractures in patients who underwent reverse total shoulder arthroplasty (RTSA). METHODS: We retrospectively evaluated all RTSAs performed by the senior author between 1/1/2013 and 6/1/2019. We evaluated patient demographics including gender, age, prevalence of comorbidities including osteoporosis, inflammatory arthritis, diabetes, and endocrine disorders such as hypothyroidism. We also evaluated preoperative and 2-week postoperative radiographs for center of rotation medialization (CORM) as distance between the center of the humeral head or glenosphere and the line of the deltoid, and distalization via the acromial-greater tuberosity distance (AGT). We evaluated inter- and intra-rater reliability via intraclass correlation coefficients. RESULTS: We included 335 RTSAs with a minimum of 3 months of follow-up in the analysis. Reliability was acceptable with all intraclass correlation coefficients> 0.75. Symptomatic acromial and scapular spine stress fractures were significantly more common in those with inflammatory arthritis than those without (18% vs. 5%, P = 0.016). The rate of fracture was highest in patients with rheumatoid arthritis (24% vs. 5.2%, P = 0.003). There was no statistically significant association between symptomatic fractures and preoperative CORM or AGT (P = 0.557, P = 0.528) or postoperative CORM or AGT (P = 0.56, P = 0.102). There also was no statistically significant correlation between symptomatic stress fracture and patient age, gender, BMI, smoking, osteoporosis, gout, medical comorbidity, or previous shoulder surgery. CONCLUSION: In this retrospective analysis of postoperative RTSA, symptomatic acromial and scapular stress fractures were significantly more common in patients with rheumatoid arthritis and thus precautions should be taken in these patients.

Glenoid retroversion associates with deltoid muscle asymmetry in Walch B-type glenohumeral osteoarthritis.

BACKGROUND: The etiologies of glenohumeral osteoarthritis (GHOA) and eccentric glenoid wear within GHOA are unknown, but muscular imbalance may play a role. The purpose of the present study was to determine the relationship between deltoid muscle area, GHOA, and eccentric glenoid wear. We hypothesized that patients with GHOA would have overall deltoid atrophy as compared with controls and that increasing posterior deltoid areas would associate with glenoid retroversion in the Walch B-type (eccentric) GHOA group. METHODS: The study was a retrospective review of computed tomography imaging studies. We included a control group of subjects without GHOA and a group of individuals with GHOA before undergoing total shoulder arthroplasty. We assigned Walch types via consensus. Cross-sectional area was measured for the anterior and posterior deltoid musculature demarcated via the scapular line, normalized to the total deltoid area. Absolute and normalized total, anterior, and posterior deltoid areas were compared between controls and the entire GHOA group. Normalized anterior and posterior deltoid areas were compared between Walch A-type and B-type GHOA patients within the GHOA group. Univariate linear regression was used to evaluate for an association between glenoid retroversion and normalized posterior deltoid areas in controls, Walch A-type, and Walch B-type patients. Multivariate linear regression analysis was used to evaluate the effects of normalized posterior deltoid area, age, sex, and height on glenoid retroversion within the Walch B-type subgroup. RESULTS: We included 99 patients with GHOA and 47 controls. The control and GHOA patients did not differ in absolute deltoid areas (21.8 ± 8.8cm2 vs. 20.6 ± 7.9cm2; P = .488). Patients with GHOA had a statistically significant increase in normalized posterior deltoid area (0.50 ± 0.10 vs. 0.46 ± 0.10; P = .032) and a reciprocal decrease in normalized anterior deltoid area (0.50 ± 0.10 vs. 0.54 ± 0.10; P = .040) compared with controls. Walch A-type and B-type patients did not differ in normalized posterior deltoid areas (0.50 ± 0.11 vs. 0.50 ± 0.10; P = .780). Normalized posterior deltoid area positively associated with glenohumeral retroversion in Walch B-type GHOA (R2 = 0.102; P = .020), a relationship maintained in multivariate linear regression, using gender, age, and height as covariates (standardized beta = 0.309, P = .027). CONCLUSION: GHOA is not associated with deltoid atrophy, calling into question the suggestion that periarticular muscular atrophy in GHOA is secondary to disuse. Increasing normalized posterior deltoid area associates with increased glenoid retroversion in patients with Walch B-type glenoid morphology. Muscular imbalance may play a role in the etiology or progression of the glenoid deformity observed in eccentric GHOA.

Outcomes after a Grammont-style reverse total shoulder arthroplasty?

BACKGROUND: The purpose of this study was to determine the factors associated with outcomes after reverse total shoulder arthroplasty (RTSA). METHODS: We retrospectively evaluated all RTSAs performed by the senior author between January 1, 2007, and November 1, 2017. We evaluated pain visual analog scale (VAS), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores and complication and reoperation rates at a minimum of 2-year follow-up. We evaluated preoperative and 2-week postoperative radiographs for glenoid inclination (GI), medialization as distance between the center of the humeral head or glenosphere and the line of the deltoid, and distalization via the acromial-greater tuberosity distance. We performed inter- and intrarater reliabilities via intraclass correlation coefficients (ICCs) and conducted a multivariable analysis. RESULTS: We included 230 RTSAs in the analysis, with 70% follow-up at a median of 3.4 years. Reliability was acceptable with all ICCs >.678. Increased postoperative GI was significantly associated with increased VAS pain postoperatively (P = .008). Increased distalization was associated with an increased rate of complications and reoperations (P = .032). Younger age (P = .008), female gender (P = .009), and lower body mass index (BMI) (P = .006) were associated with worse ASES scores. Female gender (P < .001) and lower BMI (P = .039) were associated with worse SST scores. Female gender (P = .013) and lower BMI (P = .005) were associated with worse VAS-pain scores. CONCLUSION: Age, gender, and BMI are associated with outcome after RTSA. In this retrospective analysis of a Grammont-style RTSA, superior inclination is associated with increased pain postoperatively, whereas excessive arm lengthening is associated with increased risk for complication or reoperation.

Prognostic impact of paraneoplastic syndromes on patients with non-metastatic renal cell carcinoma undergoing surgery: Results from Canadian Kidney Cancer information system.

INTRODUCTION: The impact of paraneoplastic syndromes (PNS) on survival in patients with renal cell carcinoma (RCC) is uncertain. This study was conducted to analyze the association of PNS with recurrence and survival of patients with non-metastatic RCC undergoing nephrectomy. METHODS: The Canadian Kidney Cancer information system is a multi-institutional cohort of patients started in January 2011. Patients with nephrectomy for non-metastatic RCC were identified. PNS included anemia, polycythemia, hypercalcemia, and weight loss. Associations between PNS and recurrence or death were assessed using Kaplan-Meier curves and multivariable analysis. RESULTS: Of 4337 patients, 1314 (30.3%) had evidence of one or more PNS. Patients with PNS were older, had higher comorbidity, and had more advanced clinical and pathological tumor characteristics as compared to patients without PNS (all p<0.05). Kaplan-Meier five-year estimated recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were significantly worse in patients with PNS (63.7%, 84.3%, and 79.6%, respectively, for patients with PNS vs. 73.9%, 90.8%, and 90.1%, respectively, for patients without PNS, all p<0.005). On univariable analysis, presence of PNS increased risk of recurrence (hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.48-1.90, p<0.0001) and cancer-related death (HR 1.85, 95% CI 1.34-2.54, p=0.0002). Adjusting for known prognostic factors, PNS was not associated with recurrence or survival. CONCLUSIONS: In non-metastatic RCC patients undergoing surgery, presence of PNS is associated with older age, higher Charlson comorbidity index score, advanced tumor stage, and aggressive tumor histology. Following surgery, baseline PNS is not strongly independently associated with recurrence or death.

Infraspinatus and deltoid length and patient height: implications for lateralization and distalization in reverse total shoulder arthroplasty.

BACKGROUND: Restoration of muscular strength is predicated on restoration of muscle length. The purpose of this study was to describe infraspinatus and deltoid length preoperative to reverse total shoulder arthroplasty (RTSA) to guide distalization and lateralization to restore preoperative muscle length. METHODS: This was a retrospective radiographic study. We measured the infraspinatus length on preoperative computed tomographic images and the deltoid length on preoperative radiographs. For all measurements, reliability was first established by comparing measurements between 2 observers, and intraclass correlation coefficients (ICCs) were calculated. We then calculated descriptive statistics for these muscle lengths and developed a formula to predict these muscle lengths from patient demographics. RESULTS: We measured infraspinatus length in 97 patients and deltoid length in 108 patients. Inter-rater reliability was excellent, with all ICCs >0.886. The mean infraspinatus length was 15.5 cm (standard deviation 1.3) and ranged from 12.6-18.9 cm, whereas the deltoid length was 16.2±1.7 cm and ranged from 12.5-20.2 cm. Both infraspinatus (r = 0.775, P < .001) and deltoid length (r = 0.717, P < .001) were highly correlated with patient height but did not differ between diagnoses. Formulae developed through linear regression allowed prediction of muscle length to within 1 cm in 78% and within 2 cm in 100% for the infraspinatus and 60% and 88% for the deltoid. CONCLUSION: Deltoid and infraspinatus length are variable but highly correlated with patient height. To maintain tension, 2 mm of lateralization and distalization should be added for every 6 inches (∼15 cm) of height above average for a Grammont-style RTSA.

Double-loaded suture anchors in the treatment of anteroinferior glenohumeral instability.

HYPOTHESIS: The purpose of this study was to determine the clinical outcomes of arthroscopic labral repair for anteroinferior glenohumeral instability with the use of double-loaded suture anchors. METHODS: This study evaluated a series of consecutive patients treated after the senior author changed from single- to double-loaded suture anchors for the treatment of anteroinferior glenohumeral instability with a minimum follow-up period of 2 years. We collected the following outcomes at final follow-up: visual analog scale pain score, Simple Shoulder Test score, American Shoulder and Elbow Surgeons score, and instability recurrence data. RESULTS: A total of 41 consecutive patients underwent arthroscopic labral repair with double-loaded anchors, of whom 30 (71%) were able to be contacted at a minimum of 2 years postoperatively. These patients included 4 contact or collision athletes (13%). The patients had an average of 12 ± 13 prior dislocations over an average period of 56 ± 57 months preoperatively. Mean glenoid bone loss measured 16% ± 10%, and 67% (18 of 27 patients) had glenoid bone loss ≥ 13.5%. Intraoperatively, 3.2 ± 0.4 anchors were used. No posterior repairs or remplissage procedures were performed. At an average of 6.7 ± 2.7 years' follow-up, the visual analog scale pain score was 0.8 ± 1.4; Simple Shoulder Test score, 11 ± 2; and American Shoulder and Elbow Surgeons score, 90 ± 14. Patients with bone loss < 13.5% had a 0% redislocation rate and 11% subluxation rate, whereas those with bone loss ≥ 13.5% had a 6% reoperation rate, 22% redislocation rate, and 22% subluxation rate. CONCLUSION: Arthroscopic labral repair with double-loaded anchors provides satisfactory clinical results at early to mid-term outcome assessment when glenoid bone loss is <13.5%.

Effect of complications on outcomes after revision reverse total shoulder arthroplasty.

BACKGROUND: Revision reverse total shoulder arthroplasty (RTSA) reliably improves shoulder pain and function in patients with failed shoulder arthroplasty, although it can lead to significant postoperative complications. The purpose of this study was to determine the effect of postoperative complications on shoulder pain and function after revision RTSA. METHODS: We evaluated 36 patients at an average of 4.3 years (range, 2-8.6 years) after revision of a shoulder arthroplasty to RTSA. Of these patients, 9 had a failed anatomic total shoulder arthroplasty, 23 had a failed hemiarthroplasty, and 4 had a failed RTSA. The American Shoulder and Elbow Surgeons (ASES) score and visual analog scale (VAS) pain score were evaluated postoperatively, and patients with and without postoperative complications were compared. RESULTS: The final ASES score and VAS pain score were 61 ± 23 and 2.4 ± 2.3, respectively. A major postoperative complication occurred in 7 patients (19%) (infection in 3, hematoma in 1, instability in 1, and acromial and/or scapular spine fracture in 2). Further surgical treatment was required in 5 patients (14%) (irrigation and débridement and component exchange for infection in 3, irrigation and débridement for hematoma in 1, and open reduction-internal fixation of scapular spine fracture in 1). On comparison of clinical outcomes between patients with and patients without complications, the ASES score and VAS pain score were significantly worse in patients with complications vs. those without them (ASES score, 43 ± 24 vs. 66 ± 21 [P = .04]; VAS pain score, 4.3 ± 2 vs. 2 ± 2.2 [P = .03]). CONCLUSION: Revision RTSA resulted in postoperative pain and shoulder function comparable to primary RTSA reported in the literature, although postoperative complications led to clinically significant declines in function and increases in pain.