Does forearm referencing using a retroversion guide achieve the targeted retroversion of the humeral component in reverse shoulder arthroplasty?

BACKGROUND: Component positioning affects clinical outcomes of reverse shoulder arthroplasty, which necessitates an implantation technique that is reproducible, consistent, and reliable. This study aims to assess the accuracy and precision of positioning the humeral component in planned retroversion using a forearm referencing guide. METHODS: Computed tomography scans of 54 patients (27 males and 27 females) who underwent primary reverse shoulder arthroplasty for osteoarthritis or cuff tear arthropathy were evaluated. A standardized surgical technique was used to place the humeral stem in 15° of retroversion. Version was assessed intraoperatively visualizing the retroversion guide from above and referencing the forearm axis. Metal subtraction techniques from postoperative computed tomography images allowed for the generation of 3D models of the humerus and for evaluation of the humeral component position. Anatomical humeral plane and implant planes were defined and the retroversion 3D angle between identified planes was recorded for each patient. Accuracy and precision were assessed. A subgroup analysis evaluated differences between male and female patients. RESULTS: The humeral retroversion angle ranged from 0.9° to 22.8°. The majority (81%) of the measurements were less than 15°. Mean retroversion angle (±SD) was 9.9° ± 5.8° (95% CI 8.4°-11.5°) with a mean percent error with respect to 15° of -34% ± 38 (95% CI -23 to -44). In the male subgroup (n = 27, range 3.8°-22.5°), the mean retroversion angle was 11.9° ± 5.4° (95% CI 9.8°-14.1°) with a mean percent error with respect to 15° of -21% ± 36 (95% CI -6 to -35). In the female subgroup (n = 27, range 0.9°-22.8°), mean retroversion angle was 8.0° ± 5.5° (95% CI 5.8°-10.1°) and the mean percent error with respect to 15° was -47% ± 36 (95% CI -32 to -61). The differences between the 2 gender groups were statistically significant (P = .006). CONCLUSION: Referencing the forearm using an extramedullary forearm referencing system to position the humeral stem in a desired retroversion is neither accurate nor precise. There is a nonnegligible tendency to achieve a lower retroversion than planned, and the error is more marked in females.

The acetabularization index: a novel measure of acromial bone loss prior to reverse shoulder arthroplasty.

BACKGROUND: Acromial stress fractures following reverse shoulder arthroplasty (RSA) have gained attention among specialized surgeons over the past decades craving answers regarding predisposing factors and technical aspects as how to avoid the complication. This study introduces the acetabularization index (AI) for the preoperative estimation of acromial bone loss attributed to acetabularization in cases of cuff tear arthropathy (CTA). METHODS: The acromiohumeral interval (AHI), extent of acromial acetabularization (AA), acromial height (AH), and width of acetabularization (r) were measured on preoperative radiographs and two-dimensional computed tomography scans (2D CT) of patients who underwent RSA within the timeline 2019-2023 for CTA. The AI calculated AI % = AA mm ÷ AH mm . The CTA grade was determined according to the Hamada classification. The AI values on radiographs and 2D CT were compared by a Student's t-test. Possible correlation between the AI and AHI was investigated via Pearson's coefficient. The intraclass correlation coefficient (ICC) was employed to test the interobserver reliability among two independent testers. RESULTS: The radiographs and 2D CT scans of thirty-three patients who underwent RSA were analyzed. The mean AHI, AH, AA, r, and AI values on radiographs were 5.5 ± 2 mm, 10 ± 2 mm, 2 ± 2 mm, 30 ± 4 mm, 16 ± 16%, respectively. On 2D CT, the corresponding mean values were 4.7 ± 2.5 mm, 10.8 ± 2.65 mm, 2.45 ± 2.35 mm, and 30 ± 4.5, and 22.3 ± 22%, respectively. There was a statistically significant difference between the AI values on radiographs and 2D CT (P = .000). The Pearson's correlation coefficient demonstrated a negative correlation between AI and AHI (r = - 0.33). Excellent reliability was observed by the ICC values for all parameters in both groups among two testers. CONCLUSION: The AI is a reliably measurable tool on radiographs and 2D CT scans; however, the measurements derived from radiographs vary significantly from CT based measurements due to projection restrictions. Grade IVB of the Hamada/Fukuda classification is associated with the highest AI values. Further research is warranted to assess the clinical utility of this index as a predictive tool for postoperative acromial stress fractures.

Density distribution of the type E2 glenoid in cuff tear arthropathy.

BACKGROUND: Little is known about the cortical-like and cancellous bone density variations in superiorly eroded glenoids due to cuff tear arthropathy. The purpose of this study was to analyze regional bone density in type E2 glenoids. METHODS: Clinical shoulder computed tomography scans were obtained from 32 patients with a type E2 superior erosion (10 men and 22 women; mean age, 73 years). Measurement regions were organized into quadrants (superior, inferior, anterior, and posterior) and depth regions. The depth regions were incremented by 2 mm from 0 to 10 mm. A repeated-measures multiple analysis of variance was performed to assess differences and interactions between mean densities (cortical-like and cancellous bone) in each depth, in each quadrant, and between sexes. RESULTS: The lowest cancellous bone density was found in the inferior glenoid quadrant compared with all other quadrants (307 ± 50 Hounsfield units [HU], P < .001). At the glenoid surface, the superior quadrant contained the highest mean density for cortical-like bone (895 ± 97 HU); this differed significantly from the posterior, anterior, and inferior quadrants (P ≤ .033). As for depth of measurement, cortical-like bone was most dense at the glenoid surface (0-2 mm, 892 ± 91 HU), and density decreased significantly at depths greater than 2 mm (P ≤ .019). CONCLUSION: In patients with type E2 glenoids due to cuff tear arthropathy, the densest bone was found in the superior quadrant in the area of erosion. The inferior quadrant, which tends to be unloaded as the humeral head migrates superiorly, had the lowest density bone. In addition, the best-quality bone was located at the glenoid surface as compared with deeper in the vault.

Neurologic deficit after reverse total shoulder arthroplasty: correlation with distalization.

BACKGROUND: Neurologic problems after reverse total shoulder arthroplasty (RTSA) have been reported, but there are a lack of studies regarding which nerve(s) are damaged and the outcomes for the patients who had neurologic complications after RTSA. The purpose of this study was to assess the prevalence and outcomes of neurologic deficit after RTSA and to evaluate the correlation between nonanatomic rearrangement of the shoulder joint and neurologic complications after RTSA. We hypothesized that the neurologic deficit was associated with excessive distalization or lateralization of the humerus after RTSA. METHODS: RTSA was performed on 182 consecutive shoulders with cuff tear arthropathy. Comparative analysis was performed on 34 shoulders with (group 1) and 148 shoulders without (group 2) neurologic deficit. RESULTS: The mean follow-up period in the study was 58.5 months (range: 24-124). The mean age was 71.5 ± 7.7 years in group 1 and 73.1 ± 7.2 years in group 2. Neurologic deficit after RTSA was found in 34 shoulders (19%). The mean postoperative acromiohumeral distance was 34.1 ± 11.0 mm in group 1 and 29.4 ± 7.6 mm in group 2 (P = .015). Significant differences in terms of postoperative distalization of the humerus were seen between group 1 (24.5 ± 9.4 mm) and group 2 (20.5 ± 8.3 mm) (P = .009). The most common forms of neurologic deficit after RTSA were axillary nerve (41.2%) and radial nerve (15%) injuries. Thirty shoulders (88%) had neuropraxia, and 4 shoulders (12%) had axonotmesis. By conservative treatment, all patients with neurologic complications achieved complete recovery without any additional surgery; the mean recovery period was 7.4 months (range: 2-38 months). CONCLUSION: Neurologic deficit occurred in 19% of patients who underwent RTSA, and it was significantly correlated with humeral distalization after surgery. Axillary nerve was mostly involved, and all patients with neurologic deficit achieved complete recovery without any additional surgery.

Clinical and structural outcome twenty years after repair of isolated supraspinatus tendon tears.

BACKGROUND: This study evaluated the clinical and structural outcome 20 years after repair of isolated supraspinatus tendon tears. We hypothesized that the results would deteriorate over time. MATERIALS AND METHODS: For this retrospective multicenter study, 137 patients were recalled for a clinical and imaging assessment. Six patients (4.3%) had died from unrelated causes, 52 (38.0%) were lost to follow-up, and 13 (9.5%) had undergone reoperations. This left 66 patients for clinical evaluation. Radiographs and magnetic resonance imaging were additionally performed for 45 patients, allowing assessment of osteoarthritis, tendon healing, fatty infiltration (FI), and muscle atrophy. RESULTS: The Constant Score (CS) improved from 51.5 ± 14.1 points preoperatively to 71 points (P < .05) with a mean Subjective Shoulder Value (SSV) of 77.2% ± 22%. Tendon discontinuity (Sugaya IV-V) was present in 19 of 45 patients (42 %), and there was advanced FI (Goutallier III-IV) of the supraspinatus in 12 (27%) and of the infraspinatus muscle in 16 (35%). Supraspinatus atrophy was present in 12 patients (28%), advanced arthritis in 6, and cuff tear arthropathy in 12 (30%). The CS and SSV were significantly inferior for shoulders with FI of stages III to IV (P < .05). The CS was lower in cuff tear arthropathy and correlated with infraspinatus FI. CONCLUSIONS: At 20 years after surgical repair of isolated supraspinatus tears, the clinical outcome remains significantly above the preoperative state. FI of the infraspinatus is the most influential factor on long-term clinical outcome.

Reverse total shoulder arthroplasty for an active older adult.

An active 72-year-old woman presented with pain, weakness, and decreased range of motion in her right shoulder. After a reverse total shoulder arthroplasty and 6 months of physical therapy, she was able to return to full activity level without pain.

Long-term clinical and radiographic outcome of rotator cuff repair with a synthetic interposition graft: a consecutive case series with 17 to 20 years of follow-up.

BACKGROUND: Treatment options for irreparable cuff tears include synthetic interposition grafts, but whether such grafts can maintain acceptable shoulder function and prevent cuff tear arthropathy in the long-term is unknown. METHOD: This was a retrospective case series of 13 consecutive patients treated with a synthetic interposition graft made of Dacron (DuPont, Wilmington, DE, USA). Patients were examined with bilateral ultrasonography, bilateral x-ray imaging, Constant-Murley score, and Western Ontario Rotator Cuff score. RESULTS: After a mean of 18 years (range, 17-20 years), 1 patient had died, and 12 were available for x-ray imaging and 10 also for ultrasonography and clinical scores. Cuff tear arthropathy (Hamada grade ≥2) had developed in 9 of 12 (75%; 95% confidence interval, 43%-95%), including 3 patients operated on with arthroplasty in the follow-up period. The mean absolute Constant-Murley score was 46 (standard deviation, 26), and the mean Western Ontario Rotator Cuff score was 59 (standard deviation, 20). In 7 of 10 patients (70%) with available ultrasonography, the graft was interpreted as not intact. All patients had a contralateral full-thickness tear, and 7 of 12 patients (58 %; 95% confidence interval, 28%-85%) had contralateral cuff tear arthropathy. The number of patients with cuff tear arthropathy was not significantly different between the shoulder repaired with a Dacron graft and the contralateral shoulder (P = .667). CONCLUSION: These results indicate that a synthetic interposition graft with screw fixation could not prevent cuff tear arthropathy and preserve cuff integrity in a long-term perspective.

Cuff tear arthropathy shoulder hemiarthroplasty: a radiographic outcome study.

OBJECTIVE: Cuff tear arthropathy (CTA) head prosthesis has recently become an alternative to standard shoulder hemiarthroplasty in patients with severe cuff disease by offering an increased surface area and decreased impingement. The purpose of this study is to evaluate the radiographic outcomes of CTA prosthesis and to correlate them with clinical outcomes. MATERIALS AND METHODS: In this retrospective study of CTA hemiarthroplasties over an 11-year period, two radiologists reviewed pre-/postoperative radiographs and clinical data. Radiographic complications were correlated with subsequent surgery using Cox regression models. Rates of surgical revision and radiographic complications over time were estimated using Kaplan-Meier curves. RESULTS: Ninety-seven CTA hemiarthroplasties were identified in 92 patients (5 bilateral) with a mean patient age of 68.7 years. Mean radiographic follow-up was 12 months with a mean of 3.3 radiographs per prosthesis. Twenty-six arthroplasties (26.8%) experienced at least one radiographic complication, including acromion remodeling (19.5%), anterior-posterior subluxation (5.2%), periprosthetic fracture (4.1%), glenoid remodeling (3.1%), hardware loosening (2.1%), superior subluxation (2.1%), and subsidence (1.0%). Eight cases underwent revision surgery (8.2%). The occurrence of a postoperative radiographic complication was associated with increased risk of surgical revision (hazard ratio 11.5, 95% CI: 2.4-55.7, p = 0.002); 73.5% of radiographic complications occurred by 3 months after the initial surgery (complication rate of 23.3%) based on Kaplan-Meier curve analysis. CONCLUSION: Radiographic complications after CTA head hemiarthroplasty are common with most occurring by 3 months after surgery and are highly associated with surgical revision.

Clinical and structural outcome 22 years after acromioplasty without tendon repair in patients with subacromial pain and cuff tears.

BACKGROUND: Long-term results regarding tear progression, arthropathy, and clinical scores of unrepaired rotator cuff tears are largely unknown. This study investigated whether the condition of the glenohumeral joint and rotator cuff had deteriorated at a minimum of 20 years after an acromioplasty without cuff repair and assessed the clinical results. METHODS: A retrospective analysis was conducted of a consecutive series of patients treated between 1989 and 1993 with acromioplasty without cuff repair due to subacromial pain and cuff tear. At follow-up results of x-ray, ultrasonography, and clinical scores were recorded. RESULTS: At a mean of 22 years (range, 21-25 years), 69 patients were available for follow-up with Western Ontario Rotator Cuff Index, Constant-Murley (CM) score, x-ray, and ultrasonography. Mean age at operation was 49 years (range, 19-69 years). There were 45 partial-thickness tears (PTT) and 24 full-thickness tears (FTT). Of 23 patients with FTT, 17 (74% with x-ray) had developed cuff tear arthropathy (Hamada ≥2) and 20 (87% with ultrasonography) had progressed in tear size. Mean relative CM in patients with FTT and cuff tear arthropathy was 62 (standard deviation [SD], 27), and the mean WORC was 58% (SD, 26%). In the 43 PTT patients, 3 (7% with x-ray) had developed cuff tear arthropathy and 16 (42% with ultrasonography) had tear progression. With PTT at follow-up, the mean relative CM was 101 (SD, 22), and the mean WORC was 81% (SD, 20%). CONCLUSIONS: After an acromioplasty, most unrepaired full-thickness tears will, in long-term, increase in size and be accompanied by cuff tear arthropathy changes. Most partial thickness tears remain unchanged; cuff tear arthropathy is rare, and clinical scores generally good.

[Pyoderma gangraenosum after implantation of a shoulder endoprothesis]. / Pyoderma gangraenosum nach Implantation einer Schulterendoprothese.

Pyoderma gangrenosum is an inflammatory, ulcerative, neutrophilic dermatosis that is clinically characterized by rapidly evolving, painful, necrotic skin lesions. It is typically associated with chronic systemic inflammatory or neoplastic diseases, but may also occur secondary to cutaneous injury or surgery (pathergy). Post-surgical pyoderma gangrenosum typically develops around surgical sites within the immediate postoperative period, mimicking early wound infection. However, common treatment strategies including antibiotics and debridement fail to improve or even worsen symptoms. Postoperative pyoderma gangrenosum has been most commonly reported from breast and visceral surgery. We present a case of postoperative pyoderma gangrenosum following total shoulder arthroplasty.

Milwaukee Shoulder Syndrome.

Milwaukee shoulder syndrome (MSS) is a rare, rapidly destructive arthropathy associated with calcium hydroxyapatite crystal deposition. This condition is a combination of rotator cuff tear, osteoarthritic changes, noninflammatory joint effusion containing crystals, synovial hyperplasia, cartilage and subchondral bone destruction, and multiple osteochondral loose bodies. This article discusses pathophysiology, clinical presentation, differential considerations, and magnetic resonance imaging findings of MSS.

Arthroscopic Resection of Acromioclavicular Joint Cysts and Distal Clavicle: A Report of 3 Cases.

CASE: This case report describes 3 patients who developed acromioclavicular joint cysts secondary to rotator cuff arthropathy. The patients underwent arthroscopic cyst decompression and distal clavicle resection, resulting in successful excision of the cyst and minimal cyst recurrence. CONCLUSION: Based on these cases, arthroscopic cyst decompression with concomitant distal clavicle resection should be considered as an effective alternative to serial aspirations or open cyst excision and distal clavicle resection.

Rotator Cuff Degeneration: The Role of Genetics.

BACKGROUND: The literature is certain regarding the multifactorial etiology of rotator cuff degeneration. However, it remains unclear if rotator cuff degeneration exclusively depends on intrinsic and extrinsic factors or if it is also genetically determined. We compared the health status of cuff tendons, evaluated with a magnetic resonance imaging (MRI) study, between elderly monozygotic and dizygotic twins with the aim of separating the contributions of genetics from shared and unique environments. METHODS: The rotator cuff tendon status was assessed using the Sugaya classification by MRI. Heritability, defined as the proportion of total variance of a specific characteristic in a particular population due to a genetic cause, was calculated as twice the difference between the intraclass correlation coefficients for monozygotic and dizygotic pairs. The influence of shared environment, which contributes to twin and sibling similarity, was calculated as the difference between the monozygotic correlation coefficient and the heritability index. RESULTS: We identified 33 pairs of elderly twins: 17 monozygotic pairs and 16 dizygotic pairs, with a mean age (and standard deviation) of 64.62 ± 3.32 years. The polychoric correlation was 0.62 in monozygotic twins and 0.53 in dizygotic twins. The calculated heritability index was 0.18 (18%), and the contribution was 0.44 (44%) for the shared environment and 0.38 (38%) for the unique environment. CONCLUSIONS: The role of genetics in rotator cuff degeneration is quantified by our study on elderly monozygotic and dizygotic twins; however, it is only partial with respect to the contribution of shared and unique environments.

Evaluation of the Subscapularis Tendon Tears on 3T Magnetic Resonance Arthrography: Comparison of Diagnostic Performance of T1-Weighted Spectral Presaturation with Inversion-Recovery and T2-Weighted Turbo Spin-Echo Sequences.

Objective: To compare the T1-weighted spectral presaturation with inversion-recovery sequences (T1 SPIR) with T2-weighted turbo spin-echo sequences (T2 TSE) on 3T magnetic resonance arthrography (MRA) in the evaluation of the subscapularis (SSC) tendon tear with arthroscopic findings as the reference standard. Materials and Methods: This retrospective study included 120 consecutive patients who had undergone MRA within 3 months between April and December 2015. Two musculoskeletal radiologists blinded to the arthroscopic results evaluated T1 SPIR and T2 TSE images in separate sessions for the integrity of the SSC tendon, examining normal/articular-surface partial-thickness tear (PTTa)/full-thickness tear (FTT). Diagnostic performance of T1 SPIR and T2 TSE was calculated with arthroscopic results as the reference standard, and sensitivity, specificity, and accuracy were compared using the McNemar test. Interobserver agreement was measured with kappa (κ) statistics. Results: There were 74 SSC tendon tears (36 PTTa and 38 FTT) confirmed by arthroscopy. Significant differences were found in the sensitivity and accuracy between T1 SPIR and T2 TSE using the McNemar test, with respective rates of 95.9-94.6% vs. 71.6-75.7% and 90.8-91.7% vs. 79.2-83.3% for detecting tear; 55.3% vs. 31.6-34.2% and 85.8% vs. 78.3-79.2%, respectively, for FTT; and 91.7-97.2% vs. 58.3-61.1% and 89% vs. 78-79.3%, respectively, for PTTa. Interobserver agreement for T1 SPIR was almost perfect for T1 SPIR (κ = 0.839) and substantial for T2 TSE (κ = 0.769). Conclusion: T1-weighted spectral presaturation with inversion-recovery sequences is more sensitive and accurate compared to T2 TSE in detecting SSC tendon tear on 3T MRA.

Deltoid muscle volume affects clinical outcome of reverse total shoulder arthroplasty in patients with cuff tear arthropathy or irreparable cuff tears.

We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA.

Retroverted glenoid reconstruction using glenoid plate in reverse shoulder arthroplasty.

PURPOSE: The objective of this study is to evaluate the clinical and radiological results of reverse shoulder arthroplasty (RSA) with glenoid plating in a consecutive series of patients affected by cuff tear glenohumeral arthropathy with glenoid retroversion >15°. We hypothesized that autologous humeral head graft may be better stabilized between the baseplate and the native glenoid surface with the use of a glenoid plate. METHODS: Twenty consecutive patients affected by cuff tear arthropathy with glenoid retroversion >15° (B2 or C according to Walch classification) were enrolled in this study. To reconstruct the glenoid, a dedicated plate was used in addition to the standard reverse shoulder baseplate and the glenosphere. Clinical and radiological assessment was performed using constant score (CS), subjective shoulder value (SSV), X-rays and CT scan at 6, 12 and 24 months of follow-up. Healing and resorption of the graft and detection of the glenoid version were assessed. RESULTS: Sixteen patients were available for final follow-up. The mean preoperative retroversion of the glenoid was 24°, while the post-op was 2° (p = 0.002). At 24 months of follow-up, mean CS and SSV were 61 and 70. Respect to preoperative scores, the results were statistically significant (p < 0.001). The last CT scan revealed: a complete healing of the graft in 100% of cases; graft resorption less than 25% in two patients (12.5%); glenoid retroversion of 4°. A negative statistically significant correlation was found between final CS and preoperative glenoid retroversion (0.039). CONCLUSIONS: The present study reports the favorable outcomes of retroverted glenoid reconstruction with glenoid plates in RSA, an alternative method to address severe glenoid deficiency. LEVEL OF EVIDENCE: Level IV, case series with no comparison group.

Proton Density Fat-Fraction of Rotator Cuff Muscles Is Associated With Isometric Strength 10 Years After Rotator Cuff Repair: A Quantitative Magnetic Resonance Imaging Study of the Shoulder.

BACKGROUND: Quantitative muscle fat-fraction magnetic resonance (MR) imaging techniques correlate with semiquantitative Goutallier scores with failure after rotator cuff (RC) repair. PURPOSE: To investigate the relationship of proton density fat fraction (PDFF) of the RC muscles with semiquantitative MR scores, cartilage T2 relaxation times, and clinical isometric strength measurements in patients 10 years after unilateral RC repair. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Bilateral shoulder MR imaging was performed in 13 patients (11 male, 2 female; age, 72 ± 8 years) 10.9 ± 0.4 years after unilateral autologous periosteal flap augmented RC repair (total shoulders assessed, N = 26). Goutallier classification, muscle atrophy, RC tendon integrity, and cartilage defects were determined based on morphological MR sequences. A paracoronal 2D multi-slice multi-echo sequence was used for quantitative cartilage T2 mapping. A chemical shift-encoding-based water-fat separation technique (based on a 6-echo 3D spoiled gradient echo sequence) was used for quantification of the PDFF of RC muscles. Isometric shoulder abduction strength was measured clinically. Mean and SD, Pearson correlation, and partial Spearman correlation were calculated. RESULTS: There were 6 RC full-thickness retears in ipsilateral shoulders and 6 RC full-thickness tears in contralateral shoulders. Isometric shoulder abduction strength was not significantly different between ipsilateral and contralateral shoulders (50 ± 24 N vs 54 ± 24 N; P = .159). The mean PDFF of RC muscles was 11.7% ± 10.4% (ipsilateral, 14.2% ± 8.5%; contralateral, 9.2% ± 7.8%; P = .002). High supraspinatus PDFF correlated significantly with higher Goutallier scores ( R = 0.75, P < .001) and with lower isometric muscle strength ( R = -0.49, P = .011). This correlation remained significant after adjustment for muscle area measurements and tendon rupture ( R = -0.41, P = .048). More severe cartilage defects at the humerus were significantly associated with higher supraspinatus PDFF ( R = 0.44; P = .023). Cartilage T2 values did not correlate with muscle PDFF ( P > .05). CONCLUSION: MR imaging-derived RC muscle PDFF is associated with isometric strength independent of muscle atrophy and tendon rupture in shoulders with early and advanced degenerative changes. It therefore provides complementary, clinically relevant information in tracking RC muscle composition on a quantitative level.

Optimizing baseplate position in reverse total shoulder arthroplasty in small-sized Japanese females: technical notes and literature review.

The management of cuff tear arthropathy (CTA) has always been a challenge for shoulder surgeons. Introduction of reverse total shoulder arthroplasty (RTSA) helped in providing pain relief and improved shoulder function in patients with CTA. In this study, we aimed to evaluate the short-term clinical results and some clinical details regarding the types of available prosthesis, positioning, and size of the components for RTSA in a population of short-stature female Japanese. In our seven cases, the average glenoid size was 23.9 mm in width and 34.2 mm in height. The average width was smaller than the size of all available baseplates. We implanted reverse shoulder prostheses with baseplate that measured 28 mm in diameter and two locking screws. The center of the baseplate was shifted to allow slight anterior overhang relative to the anatomical center to avoid breakage of the posterior cortex and to achieve firm fixation. One case of humeral shaft fracture occurred while inserting the humeral stem and required encircling wiring. In our experience, the short term clinical results of RTSA were excellent, but a new prosthesis that is designed to fit the short stature of Asians with smaller glenoid and humerus should be considered.

Problems With Large Joints: Shoulder Conditions.

The shoulder is the most mobile joint in the body. It requires an extensive support system to create mobility while providing stability. Although there are many etiologies of shoulder pain, weakness, and instability, most injuries in the shoulder are due to overuse. Rotator cuff tears, labral tears, calcific tendinopathy, and impingement often result from chronic overuse injuries. Acute injuries include dislocations that can cause labral tears or other complications. Frozen shoulder refers to a typically benign condition of restricted range of motion that may spontaneously resolve but can cause prolonged pain and discomfort. The history combined with specific shoulder examination techniques can help family physicians successfully diagnose shoulder conditions. X-ray imaging typically is sufficient to rule out more serious etiologies when evaluating patients with shoulder conditions. However, imaging with magnetic resonance imaging (MRI) study or ultrasonography for rotator cuff tears, and MRI study with intra-articular contrast for labral tears, is needed to confirm these diagnoses. Corticosteroid injections and physical therapy are first-line treatments for most shoulder conditions. Surgical options typically are reserved for patients for whom conservative treatments are ineffective, and typically are performed arthroscopically.