Serial Changes of Fatty Degeneration and Clinical Outcomes after Repair of Medium-Sized Rotator Cuff Tears.

Background: This study was designed to longitudinally analyze quantitative intramuscular and perimuscular fat and evaluate clinical outcomes according to healing degree after rotator cuff repair. Methods: From June 2013 through October 2018, patients who had undergone repair due to medium-sized rotator cuff tears and serial chest computed tomography (CT) preoperatively and at early (6-12 months) and late (at least 3 years) postoperative follow-ups were included. Supraspinatus (SST) intramuscular fat fraction ratio (IFFR) and perimuscular fat fraction ratio (PFFR) were calculated using chest CT. The rotator cuff integrity was categorized as healed, smaller retear (SRT), and larger retear (LRT) by comparing the preoperative tear size and retear size in shoulder CT arthrography at postoperative follow-ups. Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder rating scale, and the Constant score preoperatively and at early and late postoperative follow-ups. Results: In the LRT group, compared with the preoperative values, there were increases in the SST IFFR and PFFR at the early (p = 0.002 and p = 0.006, respectively) and late (p < 0.001 and p < 0.001, respectively) postoperative time points. Late postoperative clinical scores (UCLA and Constant scores) were not improved compared to preoperative scores (p = 0.156 and p = 0.094, respectively). In the SRT group, there was no difference in the mean SST IFFR and PFFR between preoperative and early postoperative time points (p = 0.766 and p = 0.180, respectively), but the late postoperative values were higher than preoperative values (p = 0.009 and p = 0.049, respectively). Late postoperative clinical scores (ASES, UCLA, and Constant scores) in the SRT group improved compared to preoperative time (p < 0.001, p < 0.001, and p = 0.016, respectively). In the healed group, compared with the preoperative values, there was no difference in the mean SST IFFR and PFFR at postoperative time points; however, the late postoperative clinical scores (ASES, UCLA, and Constant scores) were improved (all p < 0.001). Conclusions: In the SRT group, IFFR and PFFR progressed in the late postoperative period and clinical scores improved over time. However, in the LRT group, IFFR and PFFR progressed in the early and late postoperative periods and clinical scores did not improve at the late postoperative follow-up.

Influence of joint volume on range of motion after arthroscopic rotator cuff repair.

BACKGROUND: Capsular contracture is a well-known etiology in the primary stiff shoulder; thus capsular contracture and resultant decreased joint volume could lead to postoperative stiffness, which is a commonly reported morbidity after arthroscopic rotator cuff repair (ARCR). The purpose of this study was (1) to quantify the joint volume (total joint volume and each quadrant compartmental volume) using computed tomography arthrography (CTA) and (2) to demonstrate the relationship between joint volume and postoperative range of motion (ROM) after ARCR. MATERIALS AND METHODS: Eighty-three patients (60 ± 5.11 years, men = 26, women = 57) who had undergone ARCR between January 2015 to December 2020 due to small to medium full-thickness tear and followed by CTA 6 months postoperatively were retrospectively reviewed. An image reconstruction program (3D Slicer, version 4.11.2 software) was used to calculate the joint volume (total joint volume and quadrant compartment joint volumes; anteroinferior, anterosuperior, posterosuperior and posteroinferior). For shoulder ROM, data including scaption (Sc), external rotation on side (ERs), external rotation at 90° (ER90), and internal rotation on back (IRb) were collected 6 months postoperatively. An evaluation of the correlation between joint volume and each shoulder motion was performed. RESULTS: There were moderate correlations between the total joint volume and each motion (Sc: Pearson coefficient, 0.32, p = 0.0047; ERs: Pearson coefficient, 0.24, p = 0.0296; ER90: Pearson coefficient, 0.33, p = 0.0023; IRb: Pearson coefficient, 0.23, p = 0.0336). Among the quadrant compartments, the anteroinferior (Sc: Pearson coefficient, 0.26, p = 0.0199; ERs: Pearson coefficient, 0.23, p = 0.0336; ER90: Pearson coefficient, 0.25, p = 0.0246; IRb: Pearson coefficient, 0.26, p = 0.0168) and posterosuperior (Sc: Pearson coefficient, 0.24, p = 0.029; ER90: Pearson coefficient, 0.29, p = 0.008; IRb: Pearson coefficient, 0.22, p = 0.0491) and posteroinferior (Sc: Pearson coefficient, 0.30, p = 0.0064; ER90: Pearson coefficient, 0.29, p = 0.0072) showed moderate correlations with each shoulder motion. CONCLUSION: Total joint volume, anteroinferior compartment joint volume, posterosuperior compartment joint volume and posteroinferior compartment joint volume were related to postoperative ROM after ARCR. Perioperative methods to increase the joint volume, especially the anteroinferior, posterosuperior and posteroinferior parts of the capsule may prevent postoperative stiffness after ARCR. LEVEL OF EVIDENCE: Level III; Retrospective Case-Control Study.

Evaluation of Scapula and Humerus Bone Change after Repair of Small- to Medium-Sized Rotator Cuff Tears: Comparison between Healing and Retear Groups Using Three-Dimensional Computed Tomography.

Background: Rotator cuff tendon retears after rotator cuff repair cause glenohumeral joint instability, which results in changes in the glenoid and humerus head. However, limited data are available on the bone change after repair of small- to medium-sized rotator cuff tears. The aim of this study was to evaluate the difference of glenoid and humerus bone changes between healing and retear groups after repair of small- to medium-sized rotator cuff tears. Methods: Among patients who had arthroscopic repair due to small- to medium-sized rotator cuff tears from January 2009 to January 2017, 49 patients who underwent both preoperative and postoperative (at least 3 years after surgery) shoulder computed tomography were enrolled. Using three-dimensional reconstruction program (3D Slicer) and shape analysis program (SlicerSALT), we compared the occurrence and degree of glenoid bone change, glenoid inclination change, retroversion change, and glenoid center, as well as the degree of humerus head change, between the healing and retear groups. Results: The occurrence of glenoid bone change was significantly more common in the retear group than in the healing group (p = 0.026). The degree of bone change in the 11-1 o'clock axial plane and 10-8 o'clock, 11-7 o'clock, and 12-6 o'clock coronal plane and the degree of glenoid inclination change were significantly larger in the retear group than the healing group (p = 0.026, p = 0.026, p = 0.026, p = 0.026, and p = 0.014, respectively), but the average value of glenoid bone change in the retear group was within the range of 0.14 to 1.01 mm for each plane. The mean humeral head change was 5.69 ± 3.67 mm increase in the retear group and 1.27 ± 2.02 mm increase in the healing group. Compared with the healing group, the retear group showed statistically significantly increased humeral head change (p < 0.001). Conclusions: There was difference in glenoid and humerus bone change between the healing and retear groups at midterm follow-up after repair of small- to medium-sized tears. However, considering the measurement bias, the difference between the two groups was within the measurement error range.

Postoperative clinical outcomes and radiological healing according to deep and superficial layer detachment in first facet involving subscapularis tendon tear.

BACKGROUND: Subscapularis tendon insertion at the first facet has separate layers (deep and superficial). The purpose of this study is to evaluate postoperative clinical outcomes and radiological healing according to each layer of detachment in the first facet involving subscapularis tendon tear. METHODS: Eighty-three patients who underwent arthroscopic repair due to First facet involving the scapularis tendon tear accompanying small to medium sized posterosuperior cuff tear were classified into three groups (group A: deep layer partial detachment, group B: deep layer complete detachment, but no superficial layer detachment, and group C: deep layer and superficial layer complete detachment). Subscapularis tendon healing was evaluated using computed tomography arthrogram and clinical result was evaluated using American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score and University of California Los Angeles (UCLA) shoulder score. RESULTS: Retear rate of the subscapularis tendon was 2.2%, 18.2%, and 33.3% in group A, group B, and group C, respectively. These rates showed statistically significant difference among the three groups, which were classified by deep and superficial layer detachment in the first facet (p=0.003). Group A showed significant difference in subscapularis tendon healing compared with group B and group C (p=0.018 and p<0.001, respectively), but there was no statistical difference between group B and group C (p=0.292). Regarding clinical outcomes, there was no significant difference among three groups in ASES and UCLA score at final follow-up (p=0.070 and p=0.106, respectively). CONCLUSIONS: Complete detachment of deep layer may be related with retear occurrence regardless with detachment of superficial layer, but clinical outcome may not be related with each layer detachment in the first facet involving subscapularis tendon tear.

Comparison of Dynamic In Vivo Shoulder Kinematics Before and After Superior Capsular Reconstruction for Irreparable Rotator Cuff Tears.

BACKGROUND: Superior capsular reconstruction (SCR) is an alternative surgical option for young active patients with irreparable rotator cuff tears without arthritis. Although cadaveric studies have shown superior stability of the humerus, it remains unclear whether the humerus migrates superiorly after SCR in vivo. PURPOSE: To analyze the change in glenohumeral translation in patients before and after SCR. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 22 patients who underwent SCR by a single surgeon for irreparable rotator cuff tears were included. Among them, 14 patients had intact grafts, and 8 patients were diagnosed with retears on 1-year postoperative magnetic resonance imaging (MRI) scans. Fluoroscopy was performed in all patients preoperatively and at 3-month, 6-month, and 1-year follow-up. Moreover, 3-dimensional bone models from computed tomography, MRI, and fluoroscopic scans during scapular plane abduction of the shoulder joints were analyzed. RESULTS: In the intact graft group, 3-dimensional dynamic shoulder kinematics at 6 months (P = .026) and 1 year (P = .032) postoperatively showed statistically significant decreases in humeral head superior translation compared with preoperatively. The ≥6-mm acromiohumeral distance (AHD) subgroup had a larger decrease in humeral head superior translation from preoperatively than did the <6-mm AHD subgroup (6 months: P = .026; 1 year: P = .032). The retear group had significantly greater humeral head superior translation at 1 year postoperatively than did the ≥6-mm and <6-mm AHD subgroups (post hoc test: P < .001; ≥6-mm AHD vs retear group: P = .001; <6-mm AHD vs retear group: P = .012). CONCLUSION: SCR with intact grafts resulted in decreased humeral head superior translation after 6 months. Patients with retears showed no improvement in humeral head superior translation. Patients with a preoperative AHD <6 mm had less improvement in humeral head superior translation than did those with a preoperative AHD ≥6 mm. Early surgical treatment before an excessive decrease in preoperative AHD could be helpful for postoperative humeral head translation recovery.

Rotator cuff tear incidence association with critical shoulder angle and subacromial osteophytes.

BACKGROUND: The concomitant presence of a heel-type osteophyte may affect the critical shoulder angle (CSA) correlation with rotator cuff tears (RCT). METHODS: We retrospectively reviewed patients with and without a full-thickness RCT who underwent magnetic resonance imaging (MRI) and radiographic imaging of the shoulder. The patients were divided into 3 groups according to the CSA as high CSA group, >38°; middle CSA group, 33°-38°; and low CSA group, <33°. We confirmed the presence of heel-type osteophytes, quadrangular osteophytes protruding inferiorly from the undersurface of the anterolateral acromion like the heel of a shoe, and excluded other types of osteophytes. RESULTS: Among the patients, 84.6% in the high CSA group, 60.3% in the middle CSA group, and 68.3% in the low CSA group had a RCT (P = .041). In patients without an osteophyte, 76.9% in the high CSA group, 38.5% in the middle CSA group, and 52.6% in the low CSA group had a RCT (P = .024). In patients with an osteophyte, 92.3% in the high CSA group, 80.3% in the middle CSA group, and 92.2% in the low CSA group had a RCT (P = .106). CONCLUSIONS: RCT was affected more by osteophytes than CSA when CSA and osteophytes were evaluated together as a related factor for RCT. This perhaps suggests no correlation of CSA alone with RCT. Therefore, the presence of an osteophyte must be considered when evaluating the relation of CSA to RCT.

Can inadequate acromiohumeral distance improvement and poor posterior remnant tissue be the predictive factors of re-tear? Preliminary outcomes of arthroscopic superior capsular reconstruction.

PURPOSE: The factors affecting the anatomical and functional outcomes of arthroscopic superior capsular reconstruction (ASCR) were investigated in this study. Continuity between the posterior remnant tissue and graft, as well as medial-to-lateral anatomical graft continuity, might play a vital role in shoulder stability and functional recovery, which could be correlated with postoperative factors such as the acromiohumeral distance (AHD). METHODS: Thirty-two patients (36 shoulders) who underwent ASCR were included. The follow-up period was 24.8 ± 6.9 months. The relationship between graft continuity and preoperative, intraoperative, and postoperative factors that could affect the clinical and radiological outcomes of ASCR were investigated. RESULTS: The American Shoulder and Elbow Surgeons score increased from 50.3 ± 9.1 points preoperatively to 84.0 ± 5.0 points postoperatively (p < 0.01), and the Constant score increased from 56.3 ± 9.0 to 82.8 ± 5.6 points (p = 0.02). Re-tearing occurred in 13 patients during the postoperative follow-up period. The re-tear rate was relatively high (36.1%). The gap between the immediate postoperative and preoperative AHDs was 1.6 ± 2.2 mm in the re-tear (+) group and 3.8 ± 2.8 mm in the re-tear (-) group (p = 0.02). The integrity of the posterior remnant tissue had a statistically significant and different re-tear rate (p < 0.01). CONCLUSION: Care should be taken in patients with inadequate AHD improvement and poor posterior remnant tissue immediately postoperatively, because the possibility of re-tearing is high. Therefore, better results can be predicted when considering these factors at the time of surgery. LEVEL OF EVIDENCE: IV.

Relationship of Intraoperative Anatomical Landmarks, the Scapular Plane and the Perpendicular Plane with Glenoid for Central Guide Insertion during Shoulder Arthroplasty.

BACKGROUND: This study was undertaken to evaluate the positional relationship between planes of the glenoid component (the scapular plane and the perpendicular plane to the glenoid) and its surrounding structures. METHODS: Computed tomography (CT) images of both shoulders of 100 patients were evaluated using the 3-dimensional CT reconstruction program (Aquarius®; TeraRecon). We determined the most lateral scapular bony structure of the scapular plane and measured the shortest distance between the anterolateral corner of the acromion and the scapular plane. The distance between the scapular plane and the midpoint of the line connecting the posterolateral corner of acromion and the anterior tip of the coracoid process (fulcrum axis) was also evaluated. The perpendicular plane was then adjusted to the glenoid and the same values were re-assessed. RESULTS: The acromion was the most lateral scapular structure of scapular plane and perpendicular plane to the glenoid. The average distance from the anterolateral corner of the acromion to the scapular plane was 10.44 ± 5.11 mm, and to the plane perpendicular to the glenoid was 9.55 ± 5.13 mm. The midpoint of fulcrum axis was positioned towards the acromion and was measured at 3.90 ± 3.21 mm from the scapular plane and at 3.84 ± 3.17 mm from the perpendicular plane to the glenoid. CONCLUSIONS: Our data indicates that the relationship between the perpendicular plane to the glenoid plane and its surrounding structures is reliable and can be used as guidelines during glenoid component insertion (level of evidence: Level IV, case series, treatment study).

Normal Range of Humeral Head Positioning on the Glenoid on Magnetic Resonance Imaging: Validation through Comparison of Computed Tomography and Magnetic Resonance Imaging.

BACKGROUND: To determine the normal range of humeral head positioning on magnetic resonance imaging (MRI). METHODS: We selected normal subjects (64 patients; group A) to study the normal range of humeral head positioning on the glenoid by MRI measurements. To compare the MRI measurement method with the computed tomography (CT), we selected group B (70 patients) who underwent both MRI and CT. We measured the humeral-scapular alignment (HSA) and the humeral-glenoid alignment (HGA). RESULTS: The HSA in the control group was 1.47 ± 1.05 mm, and the HGA with and without reconstruction were 1.15 ± 0.65 mm and 1.03 ± 0.59 mm, respectively, on MRI. In the test group, HSA was 2.67 ± 1.47 mm and HGA with and without reconstruction was 1.58 ± 1.16 mm and 1.49 ± 1.08 mm, on MRI. On CT, the HSA was 1.72 ± 1.01 mm, and HGA with and without reconstruction were 1.54 ± 0.96 mm and 1.59 ± 0.93 mm, respectively. HSA was significantly different according to image modality (p=0.0006), but HGA was not significantly different regardless of reconstruction (p=0.8836 and 0.9234). CONCLUSIONS: Although additional CT scans can be taken to measure decentering in patients with rotator cuff tears, reliable measurements can be obtained with MRI alone. When using MRI, it is better to use HGA, which is a more reliable measurement value based on the comparison with CT measurement (study design: Study of Diagnostic Test; Level of evidence II).

Does final component alignment correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty?

PURPOSE: To examine, with a navigation, whether the final component alignments correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty (TKA), and to evaluate the factors affecting alignment deviation. METHODS: A total of 222 patients (276 knees) who underwent navigation-assisted TKA between September 2012 and January 2014 due to osteoarthritis were retrospectively reviewed. The deviation between the alignment of bone resection surfaces and the final alignment of femoral and tibial components was measured. Factors associated with alignment deviation of greater than 2° (outliers) were evaluated. These included age, sex, body mass index, bone mineral density (T score), preoperative and postoperative mechanical femorotibial angle, preoperative and postoperative flexion contractures, and the difference between medial and lateral gaps in knee extension or flexion. RESULTS: Outliers consisted of 24 cases (8.6%) on the femoral coronal plane, 4 cases (1.4%) on the tibial coronal plane, and 48 cases (17.4%) on the tibial sagittal plane. In the coronal plane (femur and tibia), the outliers were associated with preoperative [p < 0.001; odds ratio (OR) 0.774; 95% confidence interval (CI) 0.672-0.891] and postoperative (p < 0.001; OR 0.240; 95% CI 0.123-0.468) flexion contractures; a difference of 3 mm or more between the medial and lateral gaps in knee extension (p < 0.041; OR 5.805; 95% CI 1.075-31.343); and a T score of less than -2.5(p < 0.024; OR 5.899; 95% CI 1.258-27.664). In the sagittal plane of the tibia, the outliers were associated with preoperative (p < 0.001; OR 0.886; 95% CI 0.829-0.946) and postoperative (p < 0.031; OR 0.803; 95% CI 0.659-0.980) flexion contractures. CONCLUSION: There was a deviation between the alignments of the bone resection surfaces and the final alignments of components. With larger preoperative and postoperative flexion contractures in the coronal and sagittal planes, there were more outlier risks. The outliers in the coronal plane were associated with a difference of 3 mm or more between the medial and lateral gaps in knee extension and poor bone quality. Awareness of such alignment deviation and related factors can help diminish the outliers after TKA. LEVEL OF EVIDENCE: IV.

Clinical results associated with changes of posterior tibial slope in total knee arthroplasty.

PURPOSE: The purpose of this retrospective study is to investigate the effect of posterior tibial slope (PTS) on clinical results in total knee replacement arthroplasty (TKA). MATERIALS AND METHODS: We analyzed 801 knees in 768 patients who underwent TKA using a cruciate-retaining prosthesis for osteoarthritis from July 2003 to July 2009. PTS was measured on simple X-ray films and patients were divided into 5 groups, according to the change in PTS that was calculated by subtracting the preoperative from the postoperative PTS: group 1, >3°; group 2, 3° to 1°; group 3, 1° to -1°; group 4, -1° to -3°; and group 5, <-3°. We analyzed the correlations between the change in PTS and clinical results, such as Knee Society knee score, Knee Society functional score, Feller patella score, Kujala score, visual analog scale score, range of motion, and complications. RESULTS: There was no statistically significant intergroup difference; however, Feller patella score and Kujala score were significantly different in groups 2 and 3. There were no complications, such as progressive loosening of implants, fractures of polyethylene inserts and wears. CONCLUSIONS: Clinically meaningful improvement was observed in all patients after TKA. Groups 2 and 3 (3° to -1°) showed significant improvement compared to the other groups.