The Fate of the Shoulder Post Rotator Cuff Repair: Biomechanical Properties of the Supraspinatus Tendon and Surrounding Structures

The study aimed to describe the changes in biomechanical properties of the supraspinatus tendon, deltoid muscle, and humeral head post arthroscopic rotator cuff repair using shear wave elastography. Shear wave velocity of the tendon, deltoid, and humeral head of 48 patients was measured at predetermined sites at 1 week, 6 weeks, 12 weeks, 6 months, and 12 months post repair. One-way ANOVA with Tukey's correction and Spearman's correlation were performed. Mean±SEM healing tendon stiffness, adjacent to tendon footprint, increased from 1 week (6.2±0.2 m/s) to 6 months (7.5±0.3 m/s) and 12 months (7.8±0.3 m/s) (P<0.001). Mean±SEM deltoid muscle stiffness was higher at 12 months (4.1±0.2 m/s) compared to 1 week (3.4±0.1 m/s) and 12 weeks (3.5±0.1 m/s) (P<0.05). Humeral head stiffness did not change. Following arthroscopic rotator cuff repair, supraspinatus tendon stiffness increased in a curvilinear fashion over 6 months. From 6 months, deltoid muscle stiffness increased, corresponding to when patients were instructed to return to normal activities.

Minimally invasive lateral plating for diaphyseal fractures with extension into the proximal humerus and its implications for the deltoid muscle and its distal insertion: functional analysis and MR-imaging

BACKGROUND

In minimally invasive lateral plate osteosynthesis of the humerus (MILPOH) the plate is introduced through a deltoid split proximally and advanced through the central portion of the deltoid insertion and between bone and brachial muscle to the distal aspect of the humerus. The fracture is then indirectly reduced and bridged by the plate. Whereas it has been shown that the strong anterior and posterior parts of the distal deltoid insertion remain intact with this maneuver, its impact on deltoid muscle strength and muscular morphology remains unclear. It was the aim of this study to evaluate deltoid muscle function and MR-morphology of the deltoid muscle and its distal insertion after MILPOH.

METHODS

Six patients (median age 63 years, range 52-69 years, f/m 5/1) who had undergone MILPOH for diaphyseal humeral fractures extending into the proximal metaphysis and head (AO 12B/C(i)) between 08/2017 and 08/2020 were included. Functional testing was performed for the injured and uninjured extremity including strength measurements for 30/60/90° shoulder abduction and flexion at least one year postoperatively. Constant-Murley-Score (CMS) including an age-and gender-adjusted version, were obtained and compared to the uninjured side. Oxford Shoulder Score (OSS) and the Disability of the Arm, Shoulder and Hand (DASH) questionnaire were acquired for the affected extremity. Quality of life was measured using the EQ visual analogue scale (EQ-5D-5 L VAS). MR imaging was performed for both shoulders accordingly at the time of follow-up to assess the integrity of the distal insertion, muscle mass and fatty degeneration of the deltoid muscle. Muscle mass was determined by measuring the area of the deltoid muscle on the axial MR image at the height of the center of the humeral head.

RESULTS

Median follow-up was 29 months (range 12-48 months). Median difference of abduction strength after MILPOH was + 13% for 30°, 0% for 60° and - 22% for 90°. For flexion, the difference to the uninjured side was measured 5% for 30°, -7% for 60° and - 12% for 90°. Median CMS was 75 (66-82) for the operated extremity compared to 82 (77-90) for the uninjured side. Age- and gender-adapted CMS was calculated 88 (79-99) vs. 96 (89-107). Median OSS was 47 (40-48). DASH was 26 (15-36). EQ-5D-5 L VAS ranged from 81 to 95 with a median of 90. The median difference of the deltoid muscle area on MRI was 2% (-21% to + 53%) compared to the uninjured side. No fatty degeneration of the deltoid muscle was observed. The weaker central part of the distal deltoid insertion was exclusively perforated by the plate, leaving the strong anterior and posterior parts of the insertion intact in all patients.

CONCLUSIONS

MILPOH was associated with good functional and subjective outcome. Minor impairment of abduction strength was observed with increasing abduction angles. The reason for this impairment is unclear since MILPOH did not affect the structural quality of the deltoid muscle and the integrity of the strong anterior and posterior parts of its insertion remained intact.

TRIAL REGISTRATION

26/05/2023: ISRCTN51786146.

Contribution of shear wave elastography in evaluation of the deltoid in reverse shoulder arthroplasty: reproducibility study and preliminary results

AIMS

The current difficulty of reverse shoulder arthroplasty (RSA) is soft tissue management, and adequate deltoid tension and at present there is no consensus and available tools (X-ray, MRI, EMG) remain difficult to apply in clinical follow-up. The objective of this study was (1) to determine reliability and feasibility of deltoid elasticity assessment using ultrasound elastographyand (2) to assess the change of deltoid stiffness after RSA by comparing shear wave speed (SWS) between healthy and RSA shoulders.

MATERIAL AND METHODS

Twenty-six healthy (native shoulder, painless and complete range of motion) subjects and twelve patients with RSA were included. Two independent investigators performed 3 measurements on each segment. Measurements were bilateral. Anterior segment was also evaluated at 45° and 60° of passive abduction. Reliability and feasibility have been assessed (ISO5725-standard).

RESULTS

Coefficient of measurements variation was less than 6.1% and 0.13 m/s. In the healthy group, SWS was not significantly different between anterior and middle segments; however, the SWS of the posterior segment was significantly lower than others (p<0.0001). In abduction position, compared to the rest position, SWS of the anterior segment decreased at 45° abduction (p=0.0003) and increased at 60° abduction (p<0.0001). Variability of measurement was higher in the RSA group. No significant difference was found between the SWS measurement of the operated and non-operated side. SWS measurements of the operated side of the anterior and middle segment were significantly higher compared to the healthy group. In abduction position, compared to rest position, no difference in SWS of the anterior segment was found at 45° abduction (p=0.71) and nor at 60° abduction (p=0.75).

CONCLUSION

This study demonstrated feasibility and reliability of shoulder assessment with shear wave elastography. Reference values for asymptomatic patients can already be used in future studies on shoulder pathology and surgery.

Anterior deltoid muscle tension quantified with shear wave ultrasound elastography correlates with pain level after reverse shoulder arthroplasty

INTRODUCTION

Reverse shoulder arthroplasty (RSA) leads to medialization and distalization of the centre of rotation of the shoulder joint resulting in lengthening of the deltoid muscle. Shear wave ultrasound elastography (SWE) is a reliable method for quantifying tissue stiffness. The purpose of this study was to analyse if deltoid muscle tension after RSA correlates with the patients' pain level. We hypothesized that higher deltoid muscle tension would be associated with increased pain.

MATERIAL AND METHODS

Eighteen patients treated with RSA were included. Constant score (CS) and pain level on the visual analogue scale (VAS) were analysed and SWE was performed on both shoulders. All three regions of the deltoid muscle were examined in resting position and under standardized isometric loading.

RESULTS

Average patient age was 76 (range 64-84) years and average follow-up was 15 months (range 4-48). The average CS was 66 points (range 35-89) and the average pain level on the VAS was 1.8 (range 0.5-4.7). SWE revealed statistically significant higher muscle tension in the anterior and middle deltoid muscle region in patients after RSA compared to the contralateral non-operated side. There was a statistically significant correlation between pain level and anterior deltoid muscle tension.

CONCLUSION

SWE revealed increased tension in the anterior and middle portion of the deltoid muscle after RSA in a clinical setting. Increased tension of the anterior deltoid muscle portion significantly correlated with an increased pain level. SWE is a powerful, cost-effective, quick, dynamic, non-invasive, and radiation-free imaging technique to evaluate tissue elasticity in the shoulder with a wide range of applications.

LEVEL OF EVIDENCE

Diagnostic study, Level III.

Isolated Traumatic Tear of the Middle Head of the Deltoid Muscle: A Case Report

CASE

A 27-year-old male pedestrian struck presented with left shoulder pain and weakness 4 months postinjury, with an isolated middle head of the deltoid tear. The patient's pain persisted despite extensive nonoperative management. The deltoid was primarily repaired to the lateral acromion using a transosseous suture repair technique.

CONCLUSION

Suture repair of the deltoid to the acromion using transosseous tunnel fixation is a successful treatment for traumatic, isolated tears of the middle head of the deltoid muscle that fail conservative treatment. After surgical repair and physical therapy, our patient recovered full, pain-free range of motion and strength at 6 months.

Ipsilateral Deltoid and Hand Compartment Syndrome: A Case Report and Review of the Literature

CASE

We present the unique case of deltoid and hand compartment syndrome in a young man after prolonged syncope because of polysubstance use. The patient was subsequently treated with urgent deltoid and hand compartment fasciotomies which resulted in full recovery of his shoulder function.

CONCLUSIONS

Patients suspected of deltoid compartment syndrome should have a thorough physical examination, followed by repeat examinations. Invasive compartment monitoring should be used in equivocal cases, in patients with decreased level of consciousness, and in patients with distracting injury. Once diagnosed, deltoid compartment syndrome (± other compartments) should be taken for emergent fasciotomy, ensuring adequate decompression of all 3 deltoid compartments.

Medial Malleolar Fractures and Associated Deltoid Ligament Disruptions: Current Management Controversies

Operative fixation of medial malleolar fractures, whether isolated or in the setting of bi- or trimalleolar fractures, remains controversial. Increasingly, anatomic reduction and internal fixation is used to treat medial malleolar fractures to avoid long-term sequelae of symptomatic nonunion and posttraumatic osteoarthritis. However, outcomes have not been significantly different between operative and nonoperative cohorts. Repair of associated deltoid ligament disruption is not common because of reportedly poor outcomes. This review provides an overview of the literature on medial malleolar fracture fixation and current treatment options. [Orthopedics. 2017; 40(2):e216-e222.].

Early Outcomes Following Metal-on-Metal Reverse Total Shoulder Arthroplasty in Patients Younger Than 50 Years

Reverse total shoulder arthroplasty (TSA) is a useful intervention for older patients with glenohumeral arthritis and a deficient rotator cuff. However, as a semiconstrained prosthesis, conventional reverse TSA implanted in a young patient could fail over time secondary to polyethylene wear and subsequent osteolysis. A metal-on-metal prosthesis may avoid this type of failure. The purpose of this study is to assess the outcomes in an initial cohort of young patients who underwent reverse TSA using a metal-on-metal prosthesis. Surgical indications included age younger than 50 years with a functioning deltoid and significant impairment of shoulder function with irreparable rotator cuff due to tumor resection, arthritis, or revision surgery. Nine patients with an average age of 37 years underwent implantation of a custom metal-on-metal reverse TSA prosthesis. All patients had a minimum 12-month follow-up or a failure of their procedure requiring revision surgery prior to 1 year. American Shoulder and Elbow Surgeons (ASES) scores, Constant scores, and range of motion were recorded and analyzed pre- and postoperatively to assess improvement, and all complications were noted. Average ASES score improved from 47 points preoperatively to 73.4 points postoperatively (P=.013). Average Constant and adjusted Constant scores improved from 20.8 points and 16% preoperatively to 61.8 points and 67.3% postoperatively, respectively (P=.019 and P=.068). Mean postoperative active forward flexion and active external rotation were 119.4° and 10°, respectively. Complications included the following: 3 patients sustained a postoperative dislocation, 1 patient had a glenoid fracture and complete loss of fixation of the baseplate, and 1 patient experienced dissociation of the glenosphere from the base-plate. Although metal-on-metal reverse TSA may appear to be an attractive choice in the treatment of young patients with limited reconstructive options, postoperative outcomes are disappointing, and the complication rate is high. [Orthopedics.2016; 39(5):e957-e961.].

The effect of deltoid lengthening on functional outcome for reverse shoulder arthroplasty

PURPOSE

Reverse shoulder arthroplasty (RSA) is based on the biomechanical advantages of lengthening the deltoid while medializing its center of rotation (COR). Little evidence exists describing the clinical benefits of these biomechanical advantages. The purpose of this study is to assess the relationship between deltoid lengthening and medialization of the COR with functional outcomes for RSA patients.

METHODS

We retrospectively reviewed patients treated with primary RSA. Radiographic measurements of deltoid length and COR, assessment of forward elevation (FE) and external rotation (ER), and functional outcome scores were obtained pre- and postoperatively. Linear regression analyses were performed to assess the relationship between these radiographic measurements and changes in shoulder functionality.

RESULTS

On average, patients improved significantly in function and functional outcome scores. Postoperative COR correlated weakly with postoperative FE. There were weakly negative correlations between increase in acromion to greater tuberosity distance and postoperative FE, and between deltoid lengthening and FE improvement.

CONCLUSIONS

Our results suggest that deltoid lengthening does not correlate with improvements in active FE or ER. These findings could indicate that change in deltoid length is less important than previously thought. Furthermore, the negative correlations seen could indicate that there is over-tensioning of the deltoid in specific cases. Further studies are needed to better assess the role of deltoid length and other factors that may impact RSA outcomes.

Optimizing Deltoid Efficiency with Reverse Shoulder Arthroplasty Using a Novel Inset Center of Rotation Glenosphere Design

INTRODUCTION

Paul Grammont's hemispherical gleno sphere concept medializes the center of rotation (CoR) to the glenoid face to increase deltoid abductor moment arms and improve muscle efficiency. Reducing glenosphere thickness to less than half its spherical radius further medializes the CoR and offers the potential for even greater improvements in efficiency. To that end, this study quantifies deltoid abducttor moment arms for six different rTSA prostheses during scapular abduction from 0° to 140°.

METHODS

A 3D computer model was developed in Uni graphics to quantify deltoid moment arms during scapular abduction for the normal anatomic shoulder, the 36 mm Grammont Delta III (Depuy, Inc.), 36 mm BIO-RSA ® (Tornier, Inc.), the 32 mm RSP® (DJO, Inc.), and the Equinoxe® rTSA (Exactech, Inc.) with three different glenosphere geometries: 38 mm x 21 mm, 46 mm x 25 mm, and the novel 46 mm x 21 mm. Each muscle was simulated as three lines from origin to insertion as the arm was elevated; positional data was exported to Matlab where the abductor moment arms were calculated for the anterior, middle, and posterior deltoid from 0° to 140° humeral abduction in the scapular plane using a 1.8:1 scapular rhythm.

RESULTS

The 46 mm x 21 mm glenosphere had the larg est average abductor moment arms and also the largest efficiency for all three heads of the deltoid, having a 4.8% to 40.7% increase in the average deltoid efficiency relative to all other designs tested. The glenosphere design with the next most efficient deltoid was the 36 mm Delta III, which had the next most medialized CoR. The two least efficient designs were the BIO-RSA ® and the DJO RSP® , which had the most lateral CoR.

DISCUSSION

These results provide new biomechanical insights on the impact of glenosphere geometry on deltoid abductor moment arms and demonstrate that subtle changes in rTSA prosthesis design can result in dramatic improvements. Increasing glenosphere diameter while also decreasing thickness to be less than half its spherical radius may minimize the muscle forces required to perform activities of daily living. Clinical follow-up is necessary to demonstrate a reduction in complications related to joint over-loading and also demonstrate greater increases in range of motion for patients with weak musculature.

Subdeltoid lipoma arborescens combined with rotator cuff tears

Lipoma arborescens, a rare benign intra-articular lesion, is characterized by lipomatous proliferation of the synovium in which the subsynovial tissue is replaced by mature adipocytes. Subdeltoid bursa is a rare location for lipoma arborescens, and only a few cases have been reported in the literature. This article reports 2 cases of subdeltoid lipoma arborescens combined with rotator cuff tears, and the possible relationships between subdeltoid lipoma arborescens and rotator cuff tears are discussed. The intra-articular villous proliferations on fat-suppressed T2-weighted magnetic resonance imaging appeared as yellowish-white lipomatous villous proliferations on arthroscopy, and finger-like lipomatous proliferation of the synovium, where the subsynovial connective tissue is replaced by mature adipocytes, on histology. Although further evidence would be necessary, the bony proliferations, in addition to bone-to-bone abrasion and inflammatory processes, may contribute to the relationship between subdeltoid lipoma arborescens and rotator cuff tears. Because this is a rare disease in a rare location, no established treatment guidelines are available for lipoma arborescens in subdeltoid bursa. For the current patients, arthroscopic excision of the lipoma arborescens and concomitant rotator cuff repair were prescribed after more than 6 months of conservative management. All patients had symptom relief and were satisfied with their results. Paying special attention to the radiologic and arthroscopic characteristics of the lipoma arborescens will help physicians and surgeons to achieve a more accurate diagnosis and effective treatment strategy, especially in patients with concomitant rotator cuff tears.

The role of subscapularis repair in reverse total shoulder arthroplasty

BACKGROUND

Controversy surrounds the role of the sub- scapularis (SSC) in reverse shoulder arthroplasty (rTSA) and the need for repair, if possible, at the conclusion of the procedure. QUESTIONS AND PURPOSE: Some investigators have concluded that an intact SSC is critical for stability; others have found no such correlation. What factors should be part of the decision-making matrix on SSC management for surgeons considering rTSA?

FINDINGS

The data on management of the SSC in rTSA support a design-based approach. Researchers have shown that the SSC is critical to stability when the surgeon uses an implant with a medialized humeral component and medialized glenoid component. However, lateralized designs allow for more stability from horizontal deltoid compression and may not require repair of the SSC. In addition, SSC repair has been shown to increase the workload of the residual posterior rotator cuff and the deltoid in rTSA, both of which may have negative consequences on overall function. Lateralization from the glenoid component increases deltoid work, whereas lateralization from the humeral component maintains deltoid efficiency while improving stability.

CONCLUSIONS

The need for SSC repair in rTSA can vary based on the implant selected. Humeral and glenoid offset influence the stability and kinematics of rTSA.

Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty

PURPOSE

This study quantifies the ability of humeral retroversion, glenoid tilt, bone graft, and varying prosthesis design parameters to restore anatomic muscle length and deltoid wrapping with reverse shoulder arthroplasty.

METHODS

A computer model simulated abduction and internal and external rotation for a normal shoulder, the RSP reverse shoulder, the Equinoxe reverse shoulder, and the Grammont reverse shoulder when implanted using various implantation methods. The length of eight different muscles and the deltoid wrapping angle were quantified to evaluate the ability of each implantation method and design to restore anatomic muscle tensioning.

RESULTS

Each reverse shoulder shifted the center of rotation medially and inferiorly relative to the normal shoulder and caused a corresponding shift in the position of the humerus. Each reverse shoulder elongated each head of the deltoid and shortened the internal and external rotators relative to the normal shoulder. The surgical techniques and prosthesis designs, which resulted in a more lateral humeral position, were associated with more deltoid wrapping and better tensioning of the anterior and posterior shoulder muscles.

CONCLUSIONS

Muscle tensioning and deltoid wrapping can be substantially altered by surgical implantation meth- ods using the Grammont reverse shoulder. However, the results of this study demonstrate that more anatomic muscle tensioning and improved deltoid wrapping are achieved using alternative prosthesis designs that better restore the lateral position of the humerus.

Trapezius tendon transfer according to Saha after neglected complete axillary nerve injury

Traumatic axillary nerve injury represents less than 1% of all nerve injuries.It is often subclinical because it is masked by the pain due to a shoulder fracture or dislocation, so that treatment is neglected for a long period. When nerve repair and physiotherapy are unsuccessful, trapezius tendon transfer may be considered. Between March 2008 and May 2009, 10 patients with neglected deltoid paralysis were treated by trapezius tendon transfer at Mansoura University hospital and in a private hospital. All patients were males. Their mean age was 27.8 years (range: 17-35). The mean follow-up period was 30 months (range: 24 to 36 months). The operations were performed according to the method described by Saha in 1967, involving transfer of the lateral extremity of the clavicle, the acromioclavicular joint and the acromion, with the insertion of the trapezius, to the proximal humerus. The authors retrospectively assessed the results according to the 5 items (a-e) of the Rowe and Zarins score: all 10 patients had (a) improved shoulder function with (e) a more stable shoulder. The mean active abduction (b) was 76 degrees (range: 50-100 degrees) and the mean active flexion (c) 78 degrees (range: 45-110 degrees). However, most authors report lower values: from 34 to 76 degrees of abduction, and from 30 to 78 degrees of flexion. Arthrodesis results in 59 to 71.43 degrees of abduction. The abduction power (d) was improved: it reached grade 3 in 7 cases and grade 4 in 3 cases. In this study, trapezius tendon transfer provided satisfactory functional improvement for paralysis of shoulder abduction after neglected complete axillary nerve injury, with improvement in shoulder stability, power and range of motion.

Surgical technique: posterior deltoid-to-triceps transfer in tetraplegic patients

Several surgical techniques exist for restoring triceps function in tetraplegic patients. The goal is to establish a more synchronized, better controlled arm that allows increased self-sufficiency and further reconstructive surgery on the hand. To obtain the most secure fixation, adjust the tension, and allow early mobilization, the technique we prefer uses the central tendon of the triceps muscle and bony block fixation reinforced by the palmaris longus.

Arthroscopic release of the deltoid contracture

BACKGROUND

The deltoid contracture is an uncommon disorder. Long-standing contracture produces winged scapula, abduction and extension contracture of the shoulder. Surgical release has been considered the treatment of choice. However, the method of approach has not been well defined. The purpose of this study was to evaluate the results of arthroscopic release of the deltoid contracture.

METHODS

A retrospective study was undertaken to evaluate the results of arthroscopic release in six patients (seven shoulders) who had a contracture of the deltoid muscle. All patients had arthroscopic release. The abduction-contracture and horizontal-adduction angle was measured after operation. The average duration of follow-up was 16 months (range, from 4 to 41 months).

RESULTS

The preoperative abduction contracture resolved completely in three shoulders. Two had a residual abduction contracture of 5° to 7° and two had a poor result with 15° abduction-contracture angle. The average postoperative abduction-contracture angle was 6° (range, 0° to 15°). The preoperative horizontal-adduction contracture was corrected, permitting at least 130° of adduction, in five shoulders. The remaining two shoulders had a postoperative horizontal-adduction angle of 120° and 110°. Overall, the average postoperative horizontal-adduction angle was 130° (range, 110° to 140°).

CONCLUSION

Arthroscopic release is an effective surgical technique to treat the deltoid contracture.

Heterotopic ossification of the deltoid muscle after arthroscopic rotator cuff repair

Heterotopic ossification (HO), a well-known sequela of trauma, burns, head injury, and certain congenital or acquired metabolic conditions, has a predilection for the hip and the elbow. This disease has uncommonly been found after elective open shoulder surgery but extremely seldom after minimally invasive surgery. In our search of the peer-reviewed literature, we found no reports of HO after arthroscopic rotator cuff repair. The clinical importance of heterotopic bone after shoulder surgery remains unclear because of inconsistent definitions, varying correlations of symptom severity and radiographic findings, and lack of treatment efficacy data. Here we report a case of severely symptomatic HO after arthroscopic rotator cuff repair - successfully treated with excision of the heterotopic bone, interval release, and manipulation.