Massive and irreparable rotator cuff tear treatment by arthroscopic partial repair with long head of the biceps tendon augmentation provides better healing and functional results than partial repair only.

BACKGROUND: The aim of this study was to compare the clinical and radiologic outcomes of 2 treatment methods for massive and irreparable rotator cuff tears (RCTs): partial repair (PR) and PR with long head of the biceps tendon (LHBT) augmentation. Biceps tendon augmentation is believed to promote better healing at the bone-tendon junction, leading to improved clinical and radiologic outcomes. METHODS: This retrospective comparative study included patients with chronic, massive and irreparable RCTs involving both the supraspinatus (SSP) and infraspinatus muscles. Only patients with failure of nonoperative treatment and at least 1 year of follow-up between 2013 and 2018 were analyzed. The patients were divided into 2 groups based on the chosen treatment method. Irreparability was defined intraoperatively as the inability to achieve sustainable repair of the SSP after complete release, typically corresponding to a Goutallier classification of stage ≥ 3 and Patte classification of stage 3. The clinical assessment protocol involved measurements of range of motion and shoulder strength, as well as the Constant-Murley score (CMS) and Simple Shoulder Test score. Radiologic assessment comprised measurements of the acromiohumeral distance, Hamada classification, Sugaya classification, and Goutallier classification of both the SSP and infraspinatus. RESULTS: The study included data from 60 patients (30 in each group) with a mean age of 62.5 years and a mean follow-up period of 34.5 months. The retear rate was 43.3% for PR with LHBT augmentation and 73.3% for PR alone (P = .036). During the final examination, statistically significant differences in favor of PR with LHBT augmentation were observed for the CMS (76.2 ± 10.9 vs. 70.9 ± 11.5, P = .034), Sugaya classification (3.5 ± 1.1 vs. 4.1 ± 0.9, P = .035), and acromiohumeral distance (5.8 ± 2 mm vs. 4.7 ± 1.3 mm, P = .021). There were no significant differences between the groups in range of motion, shoulder strength, Hamada classification, Simple Shoulder Test score, and postoperative Goutallier stage. CONCLUSION: PR with LHBT augmentation for patients with irreparable, massive RCTs provides a lower retear rate and better humeral head centralization, as well as improved results measured by the CMS, compared with PR alone.

Handball players have superior shoulder proprioception: a prospective controlled study.

BACKGROUND: Proper proprioceptive and neuromuscular control is crucial for the overhead athlete's performance. The aim of the present study was to evaluate the shoulder joint position sense (JPS) levels in overhead throwing athletes. The secondary aim was to confront the proprioceptive abilities with glenohumeral adaptive changes and pathologies among athletes. METHODS: Ninety professional handball players and 32 healthy volunteers were recruited. JPS levels were measured by an electronic goniometer and expressed as values of an active reproduction of the joint position (ARJP) and as error of ARJP (EARJP) in 3 different reference positions for each movement (abduction and flexion at 60°, 90°, and 120°; internal [IR] and external rotation [ER] at 30°, 45°, and 60°). RESULTS: Side-to-side differences revealed significantly better values of EARJP for the throwing shoulders in abduction at 90° and 120°, flexion at 90° and 120°, IR at 60°, and ER at 30° and 60° compared with the nonthrowing shoulders. Handball players showed significantly better proprioceptive levels in their throwing shoulder compared to the dominant shoulder of the control group in abduction at 90° (P = .037) and 120° (P = .001), flexion at 120° (P = .035), IR at 60° (P = .045), and in ER at 60° (P = .012). DISCUSSION: Handball players present superior shoulder JPS in their dominant throwing shoulder at high range of motion angles when compared to a nonathlete population and to their own nondominant shoulder.

Validity and Reliability of Inertial Measurement Units in Active Range of Motion Assessment in the Hip Joint.

Measuring joint range of motion has traditionally occurred with a universal goniometer, inclinometer, or expensive laboratory systems. The popularity of the inertial measurement unit (IMU) is growing, enabling the small and even single portable device to measure the range of motion. Until now, they were not used to assess hip joint range of motion. Our study aimed to check the validity of IMUs in assessing hip range of motion and compare them to other measurement devices-universal goniometer and inclinometer. Twenty participants completed three hip movements (flexion in standing and prone internal and external rotation) on both hips. Two testers independently assessed each movement with a goniometer, digital inclinometer, and IMU at different time points. To assess the agreement of active hip ROM between devices, Intraclass Correlation Coefficient (ICC) and Bland-Altman analysis were used. Furthermore, inter-rater and intra-rater reliability were also assessed by using ICC and Bland-Altman analysis. Limits of agreement (LOA) were calculated using Bland-Altman plots. The IMU demonstrated good to excellent validity (ICC: 0.87-0.99) compared to the goniometer and digital inclinometer, with LOAs < 9°, across all tested movements. Intra-rater reliability was excellent for all devices (ICC: 0.87-0.99) with LOAs < 7°. However, inter-rater reliability was moderate for flexion (ICC: 0.58-0.59, LOAs < 22.4) and poor for rotations (ICC: -0.33-0.04, LOAs < 7.8°). The present study shows that a single inertial measurement unit (RSQ Motion, RSQ Technologies, Poznan, Poland) could be successfully used to assess the active hip range of motion in healthy subjects, comparable to other methods accuracy.

Isometric Shoulder Testing Using a Forcemeter Is a Reliable Method of Strength Evaluation.

Isometric strength testing using a digital dynamometer is reliable for muscle function evaluation. It allows us to objectify manual strength assessment measurement. We tested intra- and inter-observer reliability of a user-friendly efficient digital dynamometer-the Forcemeter-equipped with a computer program to monitor the measurements and to store the data. Abduction, forward flexion, and external and internal rotation of both shoulders were tested three times in 20 healthy volunteers with no record of shoulder trauma. Isometric contracture was recorded in newtons. The first and the third test were carried out by Examiner A (intra-rater reliability); the second test, by Examiner B (inter-rater reliability). Good reliability was shown for intra-class correlation coefficient (ICC) values which mean moderate to high correlations (r = 0.66-0.93) for both examiners. Moderate to high correlations (r = 0.72-0.91) were found for comparisons between the results obtained by Examiner A.

Shoulder Range of Motion Measurement Using Inertial Measurement Unit-Concurrent Validity and Reliability.

This study aimed to evaluate the reliability of the RSQ Motion sensor and its validity against the Propriometer and electronic goniometer in measuring the active range of motion (ROM) of the shoulder. The study included 15 volunteers (mean age 24.73 ± 3.31) without any clinical symptoms with no history of trauma, disease, or surgery to the upper limb. Four movements were tested: flexion, abduction, external and internal rotation. Validation was assessed in the full range of active shoulder motion. Reliability was revised in full active ROM, a fixed angle of 90 degrees for flexion and abduction, and 45 degrees for internal and external rotation. Each participant was assessed three times: on the first day by both testers and on the second day only by one of the testers. Goniometer and RSQ Motion sensors showed moderate to excellent correlation for all tested movements (ICC 0.61-0.97, LOA < 23 degrees). Analysis of inter-rater reliability showed good to excellent agreement between both testers (ICC 0.74-0.97, LOA 13-35 degrees). Analysis of intra-rater reliability showed moderate to a good agreement (ICC 0.7-0.88, LOA 22-37 degrees). The shoulder internal and external rotation measurement with RSQ Motion sensors is valid and reliable. There is a high level of inter-rater and intra-rater reliability for the RSQ Motion sensors and Propriometer.

Shoulder Range of Motion Measurement Using Inertial Measurement Unit-Validation with a Robot Arm.

The invention of inertial measurement units allowed the construction of sensors suitable for human motion tracking that are more affordable than expensive optical motion capture systems, but there are a few factors influencing their accuracy, such as the calibration methods and the fusion algorithms used to translate sensor readings into angles. The main purpose of this study was to test the accuracy of a single RSQ Motion sensor in comparison to a highly precise industrial robot. The secondary objectives were to test how the type of sensor calibration affects its accuracy and whether the time and magnitude of the tested angle have an impact on the sensor's accuracy. We performed sensor tests for nine repetitions of nine static angles made by the robot arm in eleven series. The chosen robot movements mimicked shoulder movements in a range of motion test (flexion, abduction, and rotation). The RSQ Motion sensor appeared to be very accurate, with a root-mean-square error below 0.15°. Furthermore, we found a moderate-to-strong correlation between the sensor error and the magnitude of the measured angle but only for the sensor calibrated with the gyroscope and accelerometer readings. Although the high accuracy of the RSQ Motion sensors was demonstrated in this paper, they require further study on human subjects and comparisons to the other devices known as the gold standards in orthopedics.

Shoulder arthropathy secondary to syringomyelia: systematic review.

Purpose: The purpose of this study was to collect and evaluate clinical and radiological evidence on shoulder neuroarthropathy (NA) in syringomyelia (SM) that may support the management and treatment of patients with this condition. Materials and methods: This systematic review is based on the analysis of reports available in PubMed, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials using the following keywords: syringomyelia, neuroarthropathy, Charcot joint and shoulder degeneration. Thirty-nine publications were found presenting case reports or case series meeting our criteria. Pooled data included a group of 65 patients and 71 shoulders with NA secondary to SM. Results: The most commonly reported symptoms were range of motion (ROM) limitation, weakness, swelling, pain and dissociated sensory loss. NA is usually monolateral and concerns only the shoulder. The average active shoulder ROM was flexion -59.2° (s.d. 37.9), internal rotation -29.8° (s.d. 22.6) and external rotation -21.1° (s.d. 23.6). Most of the patients (75%) presented with complete or nearly complete proximal humerus degeneration, while the degree of glenoid preservation varied. Fifty-two neuroarthropathic shoulders were treated conservatively with physiotherapy, anti-inflammatory medication and splinting. Eighteen patients were treated by surgical intervention. Conclusion: Shoulder NA due to SM is a devastating and progressive condition, and its course is often unpredictable. Patients with unexplained shoulder degeneration should be evaluated for SM, especially if there are additional neurological symptoms. Conservative treatment usually reduces shoulder pain without improving ROM. For select patients, shoulder arthroplasty may be a better option for restoring function.

Shoulder arthropathy secondary to syringomyelia: case series of 10 patients.

PURPOSE: Neuroarthropathy is a progressive joint degeneration secondary to neurological diseases. In the upper extremity, the shoulder is the most exposed, and it is mainly caused by syringomyelia. This condition is rare; therefore, the literature has documented only a few case reports or case series of small groups of patients. METHODS: We collected data about patients with shoulder arthropathy due to syringomyelia who were treated in our two institutes and collected among members of the Polish Shoulder and Elbow Society. Our analysis was based on epidemiological data, symptoms, and clinical examinations. We also examined the results of diagnostic tests, including-spinal cord MRI and shoulder X-ray, and treatment methods and their effectiveness. RESULTS: The examined group included 10 women with an average age of 63 years. Of these, nine patients reported pain, seven reported-swelling, and nine reported-weakness. In every patient, diagnosis was confirmed by X-ray of the shoulder with joint degeneration and MRI of the spinal cord with syrinx. Two patients were operated with reverse shoulder arthroplasty; the first one had excellent result-significant active range of motion improvement and reduction of symptoms, and the second one had a good result-pain relief and moderate range of motion improvement. Other patients were conservatively treated, resulting in total or partial symptoms relief but without significant range of motion improvement. CONCLUSION: Charcot shoulder secondary to syringomyelia was mainly manifested by range of motion limitation, swelling, and pain. Both conservative and surgical treatments could be a good solution. However, if reverse arthroplasty is technically possible, it seems to be the most promising treatment for recovering function.

Isokinetic and functional shoulder outcomes after arthroscopic capsulolabral stabilization.

INTRODUCTION: Shoulder stability is secured by dynamic and static stabilizers. Rotator cuff is responsible for dynamic stabilization. In cases of shoulder instability their activity is disturbed. Capsulolabral repair restores mainly static stabilization. This surgery treatment technique of shoulder instability was first described by Bankart in 1923. His idea, with further modifications, is commonly used up to this day. Evaluation of muscle shoulder recovery after stabilization should be one of the important criteria to allow patient to return to sport and work. However, not much isokinetic assessment after capsulolabral repair was described. The aim of this study were the following: the comparative assessment of the shoulder rotatory strength in patients following arthroscopic capsulolabral repair of unilateral anterior traumatic instability and clinical assessment with comparison of pre and post-operative results. MATERIAL AND METHODS: Forty-five patients, 14 women and 31 men, with an average follow-up of 4.4 years were tested bilaterally for internal and external rotation strength at four angular velocities. ASES and UCLA tests were collected before and after surgery. RESULTS: The values of peak moment and muscle power parameters were slightly lower for an operated shoulder in comparison to a healthy shoulder for the external rotation. Total work parameter in external rotation was significantly lower for the operated shoulder in comparison to the non-operated side. The internal/external muscle group balance was lower for the operated shoulder in comparison to reference values in the women group. Furthermore, both ASES and UCLA scores were significantly higher after operation. CONCLUSIONS: After arthroscopic capsulolabral shoulder stabilization, slight differences in isokinetic evaluation, especially in external shoulder rotation, occur. It affects rotators muscle balance. In functional evaluation significant improvement in shoulder function occurs.

Clinical and radiological examination of bony-mediated shoulder instability.

The coexistence of glenoid and humeral head bone defects may increase the risk of recurrence of instability after soft tissue repair.Revealed factors in medical history such as male gender, younger age of dislocation, an increasing number of dislocations, contact sports, and manual work or epilepsy may increase the recurrence rate of instability.In physical examination, positive bony apprehension test, catching and crepitations in shoulder movement may suggest osseous deficiency.Anteroposterior and axial views allow for the detection of particular bony lesions in patients with recurrent anterior shoulder instability.Computed Tomography (CT) with multiplanar reconstruction (MPR) and various types of 3D rendering in 2D (quasi-3D-CT) and 3D (true-3D-CT) space allows not only detection of glenoid and humeral bone defects but most of all their quantification and relations (engaging/not-engaging and on-track/off-track) in the context of bipolar lesion.Magnetic resonance imaging (MRI) is increasingly developing and can provide an equally accurate measurement tool for bone assessment, avoiding radiation exposure for the patient. Cite this article: EFORT Open Rev 2020;5:815-827. DOI: 10.1302/2058-5241.5.200049.

Synovial plica of the elbow and its clinical relevance.

A synovial plica (fold) is normal anatomic finding, and occurs in 86-100% of cases; however, symptomatic plica is much less common (7.2-8.7% of all elbow arthroscopies).Synovial plica syndrome is a painful elbow condition related to symptomatic synovial plica.Synovial plica syndrome is diagnosed by clinical examination (lateral elbow pain) commonly accompanied by local tenderness, pain at terminal extension and/or painful snapping.Synovial plica syndrome may be mimicked by other elbow conditions, commonly tennis elbow, loose bodies, and degenerative arthritis.Magnetic resonance imaging or ultrasound scan may support diagnosis in correlation with clinical findings, but symptomatic plica may also be diagnosed as unexpected during elbow arthroscopy.The arthroscopic resection is effective and safe if conservative treatment fails. Cite this article: EFORT Open Rev 2020;5:549-557. DOI: 10.1302/2058-5241.5.200027.

Shoulder proprioception following reverse total shoulder arthroplasty.

Joint replacement affects the proprioception, as shown in knees, elbows, and shoulder studies. AIM: The aim was to evaluate shoulder joint position sense (JPS) following reverse total shoulder arthroplasty (rTSA) for patients with cuff arthropathy. METHODS: Twenty-nine patients that underwent unilateral rTSA (19 females, 10 males) and 31 healthy volunteers evaluated for JPS of shoulder using a dedicated high accuracy electronic goniometer. Error of active reproduction of joint position (EARJP) was assessed at the following reference positions: 30°, 60°, 90°, and 120° for forward flexion and abduction and 15°, 30°, and 45° for internal and external rotation in rTSA, contralateral non-operated, and control shoulders. RESULTS: Results of EPRJP for rTSA, contralateral, and control (respectively) are as follows:Forward flexion: 30° = (8.0 ± 5.7, 9.8 ± 6.1, and 4.9 ± 3.0), 60° = (5.0 ± 2.8, 5.9 ± 2.7, and 5.1 ± 3.2), 90° = (3.1 ± 1.6, 5.5 ± 2.6, and 3.2 ± 1.4), and 120° = (3.4 ± 2.1, 5.6 ± 4.0, and 3.5 ± 1.7)Abduction: 30° = (5.2 ± 2.5, 9.1 ± 6.1, and 4.6 ± 2.3), 60° = (5.2 ± 3.6, 6.6 ± 4.1, and 5.3 ± 3.1), 90° = (3.8 ± 2.0; 7.4 ± 5.5, and 4.1 ± 1.9), and 120° = (5.3 ± 2.9, 7.7 ± 5.3, and 4.2 ± 1.9)Internal rotation: 15° = (4.3 ± 3.1, 6.2 ± 4.4, and 2.8 ± 1.2), 30° = (3.2 ± 1.9, 4.5 ± 2.3, and 3.3 ± 1.4), and 45° = (3.5 ± 2.0, 4.1 ± 1.8, and 2.8 ± 1.0)External rotation: 15° = (3.0 ± 1.7, 4.2 ± 2.2, and 3.6 ± 1.4) and 30° = (3.1 ± 1.5, 3.8 ± 2.6, and 3.4 ± 1.6)The results showed significantly better JPS (lower EPRJP) in shoulders following rTSA and normal control shoulders comparing with the patient's contralateral shoulder. The explanation can be that rTSA improves joint kinematics and stability, which allows better muscular performance and proprioception feedback. CONCLUSION: Shoulders following rTSA show JPS superior to non-operated contralateral shoulders and comparable with healthy population shoulders. It seems that rTSA restores shoulder proprioception.

Bilateral shoulder proprioception deficit in unilateral anterior shoulder instability.

HYPOTHESIS AND BACKGROUND: Proprioception is an important element of shoulder dynamic stability. It has been shown to be affected in cases of capsular or labral injuries of the glenohumeral joint. Therefore, this study was conducted to investigate bilateral shoulder proprioception by active reproduction of joint position both in patients with post-traumatic recurrent unilateral shoulder instability and in normal healthy volunteers. METHODS: We compared 41 patients, comprising 11 female and 30 male patients with an average age of 25.6 years (range, 18-39 years), with post-traumatic unilateral anterior shoulder instability with a control group of 27 healthy volunteers with no history of shoulder problems and with normal shoulder function during examination. All patients were examined using a high-accuracy computer-controlled electronic goniometer (Propriometer). The error of active reproduction of joint position (EARJP) was measured in abduction, flexion, external rotation, and internal rotation in both shoulders. RESULTS: We observed a significant deficit in the EARJP in the unstable shoulders within the instability group. Surprisingly, similar results were recorded for the contralateral, unaffected shoulders within this group of patients compared with the control group. Joint acuity increased with higher elevation of the arm position. CONCLUSION: Unilateral shoulder injuries, resulting in instability, affect proprioception in both shoulders, as demonstrated by an increased EARJP. This is the first report of unilateral shoulder instability coexisting with inferior proprioception in both shoulders.

Prospective outcome assessment of arthroscopic arthrolysis for traumatic and degenerative elbow contracture.

BACKGROUND: The purpose of this study was to evaluate the efficacy of arthroscopic elbow release for both traumatic and degenerative contractures from intraoperative recording through the recovery time until final follow-up. METHODS: The study is based on 54 consecutive patients with extrinsic elbow contracture (traumatic in 31 and degenerative in 23) treated with arthroscopic arthrolysis by a single surgeon in 2011-2015. Range of motion (ROM) and the Mayo Elbow Performance Score (MEPS) were recorded preoperatively; intraoperatively; following release; and in the 1st, 3rd, 8th, 12th, and 26th weeks and at 2 years postoperatively. RESULTS: Significant improvements were noted in extension, flexion, and range of motion, measured both intraoperatively and at all follow-up visits. The greatest improvement in the range of motion was achieved at the time of surgery (from 89° ± 28° to 131° ± 14°, P < .001); it then decreased at 1 week to 103° ± 22° (P < .001) and slowly recovered to reach 124° ± 22° after 2 years. This was better than the preoperative value (P < .001) but worse than the intraoperative value (P = .002). A similar pattern was observed in both traumatic and degenerative contractures. The MEPS improved from 73 ± 12 preoperatively to 93 ± 14 at the final evaluation (P < .001). The ROM and MEPS results at every follow-up were comparable for both traumatic and degenerative contractures. ROM improved regardless of the severity of contracture. CONCLUSIONS: Arthroscopic elbow arthrolysis was similarly efficient in ROM restoration in both traumatic and degenerative contractures and regardless of the severity of contracture. After early deterioration, the achieved gain slowly recovers over a period of 6 months but may not recover to the ranges achieved during arthroscopy.

Rotational glenohumeral adaptations are associated with shoulder pathology in professional male handball players.

PURPOSE: Glenohumeral range of motion adaptations may affect throwing athletes and contribute to shoulder injury. The purpose of this study was to evaluate shoulder rotation deficits among elite professional handball players and its correlation to the presence of shoulder pain and morphological changes. METHODS: Eighty-seven elite professional handball players and 41 healthy non-athlete volunteers participated in the study. Evaluations included measurement of range of internal and external rotation, total arch of motion, identification of shoulder pain and ultrasound scan for diagnosis of rotator cuff tears and internal impingement. RESULTS: Glenohumeral rotational deficits (>20-25°) were found among 11 players group (13%). The throwing shoulders in the players group showed a decrease in internal rotation and an increase in external rotation with significantly larger ranges among players compared to the non-athlete group. Internal rotation deficit >20° was associated with higher incidence of shoulder pain among players. Both internal rotation deficits (>25°) and total arch of motion deficit (>20°) co-existed with higher incidence of internal impingement. Shoulder pain was common (36/97-41%) and was associated with decreased external rotation and total arch of motion. Internal impingement (found in 13/87-15%) correlated with decreased rotation ranges and a greater deficit in total arch of motion, whereas higher gain in external rotation correlated with a partial rotator cuff tear (found in 12/87-14%). CONCLUSIONS: Shoulder pathologies and problems commonly affected the group of handball players. Greater glenohumeral rotational deficits in throwing shoulders of handball players correlate with shoulder pain and internal impingement, while increased external rotation with partial rotator cuff tears. Such deficits affect 13% of the athlete population. Major clinical relevance of the study is to monitor handball players' shoulders both clinically and by proper imaging. Evaluation of range of rotation seems to identify shoulders at risk of the pathology. LEVEL OF EVIDENCE: Cross-Sectional study with control group, Level II.

Effect of arthroscopic techniques on joint volume in shoulder instability: Bankart repair versus capsular shift.

PURPOSE: The evaluation of glenohumeral joint volume in both unstable (with/without laxity) and stable shoulders (subacromial impingement) and volume reduction potential of arthroscopic techniques: (labral anchor repair vs. capsular shift). METHODS: Material was based on 133 patients: anterior shoulder instability without laxity (group I, n = 49), with laxity (group II, n = 22) and subacromial impingement (control group, n = 62) operated in 2010-2011. Group I received arthroscopic Bankart repair, group; II - arthroscopic anterior capsular plication, control group - subacromial decompression. Joint volume was measured by fluid aspiration into the syringe via arthroscope, before and after procedure. Then volume reduction potential was calculated. RESULTS: The following average values of initial joint volume were recorded: group I - 26.8 ml group II - 43.7 ml and the control group - 25.6 ml with significant differences: impingement vs. instability + laxity (p < 0.00001), impingement vs. instability without laxity (p = 0.0001). There was no significant difference between groups I and II. Joint volume was significantly reduced after labral repair (by average of 37 %, 13.8 ml, p < 0.0001). Capsular shift led to an even greater and more significant volume decrease (61 %, 26.7 ml, p < 0.001). Joint volume in the control group was reduced only by 11 %, 3.8 ml (p = 0.046). CONCLUSIONS: Patients with unstable shoulders have enlarged joint volume as compared to patients with subacromial impingement. Arthroscopic techniques lead to a significant joint volume reduction, with the most powerful effect for capsular shift. Level of Evidence - Level 2.

Reliability of measurements performed on two dimensional and three dimensional computed tomography in glenoid assessment for instability.

PURPOSE: The main purpose of this study is to establish which of two methods is more reliable in glenoid assessment for instability in pre-operative planning. Accordingly, we have studied the intra- and inter-observer reliability of glenoid parameters with the use of two-dimensional (2D) and three-dimensional (3D) reconstructed computed tomography (CT) images. METHODS: One hundred glenoids were measured with the use of 2D-CT and 3D-CT (in 3D orientation) by two independent observers (one experienced and one inexperienced). Measurements were repeated after one week for 30 randomly selected glenoids. RESULTS: The intra-class correlation coefficient (ICC) for inter-observer reliability was significantly greater for 3D-CT (0.811 to 0.915) than for 2D-CT (0.523 to 0.925). All intra-observer reliability values for 3D-CT were near perfect (0.835 to 0.997), while those for 2D-CT were less reliable (0.704 to 0.960). A dependent t-test showed that, for both observers, almost all glenoid parameters (except R and d) differed significantly (p < 0.05) between 2D and 3D measurement methods. CONCLUSIONS: Therefore, it can be concluded that 3D glenoid reconstructions are more reliable for glenoid bone loss assessment than 2D-CT. The results suggest that quantifying a glenoid defect with the use of 2D image only-even if performed by an experienced orthopaedic surgeon-is prone to errors. Differences in measurements between and within observers can be explained by plane setting and identifying glenoid rim in 2D-CT. Accordingly, we recommend that glenoid measurements should be performed in 3D orientation using 3D reconstruction obtained from CT images for pre-operative assessments, which are crucial for surgical planning.

Directional asymmetry of upper limbs in a medieval population from Poland: A combination of linear and geometric morphometrics.

OBJECTIVES: Degrees of upper-limb bilateral asymmetry reflect habitual behavior and activity levels throughout life in human populations. The shoulder joint facilitates a wide range of combined motions due to the simultaneous motion of all three bones: clavicle, scapula, and humerus. Accordingly, we used three-dimensional geometric morphometrics to analyze shape differences in the glenoid cavity and linear morphometrics to obtain the degree of directional asymmetry in a medieval population. METHODS: To calculate directional asymmetry, clavicles, humeri, and scapulae from 100 individuals (50 females, 50 males) were measured. Landmarks and semilandmarks were placed within a three-dimensional reconstruction of the glenoid cavity for analysis of shape differences between sides of the body within sexes. RESULTS: Linear morphometrics showed significant directional asymmetry in both sexes in all bones. Geometric morphometrics revealed significant shape differences of the glenoid cavity between sides of the body in females but not in males. Both indicators of directional asymmetry (%DA and %AA) did not show significant differences between sexes. PLS analysis revealed a significant correlation between glenoid shape and two humeral head diameters only in females on the left side of the body. CONCLUSIONS: The studied population, perhaps due to a high level of activity, exhibited slightly greater upper-limb bone bilateral asymmetry than other agricultural populations. Results suggest that the upper limbs were involved in similar activity patterns in both sexes but were characterized by different habitual behaviors. To obtain comprehensive results, studies should be based on sophisticated methods such as geometric morphometrics as well as standard measurements. Am. J. Hum. Biol. 28:817-824, 2016. © 2016Wiley Periodicals, Inc.

Shoulder problems in overhead sports. Part I - biomechanics of throwing.

The article discusses the biomechanical processes that occur during an overhead throw. This activity is highly specialized and requires full and proper function from the shoulder joint. It consists of active and passive stabilization and synchronous work of the accelerating and decelerating muscles. The process of the overhead throw can be divided into several phases that differ from each other in biomechanical parameters and involvement of specific muscles.