Ankle fractures are the fourth most common fracture requiring surgical management. The deltoid ligament is considered the primary stabilizer of the ankle against a valgus force. The management of the deltoid ligament in ankle fractures is currently a controversial topic no consensus exists regarding repair in the setting of ankle fractures. The purpose of this systematic review is to examine the role and indications for deltoid ligament repair in ankle fractures. A systematic database search was conducted with Medline, Pubmed and Embase for relevant studies discussing patients with ankle fractures involving deltoid ligament rupture and repair. The papers were screened independently and in duplicate by two reviewers. Study quality was evaluated using the MINORs criteria. Data extraction included post-operative outcomes, pain, range of motion (ROM), function, medial clear space (MCS), syndesmotic malreduction and complication rates. Following title, abstract and full text screening, 10 eligible studies published between 1987 and 2017 remained for data extraction (n = 528). The studies include 325 Weber B and 203 Weber C type fractures. Malreduction rate in studies with deltoid ligament repair was 7.4% in comparison to those without repair at 33.3% (p < 0.05). Eleven (4%) of deltoid ligament repair patients returned for re-operation to have implants removed in comparison to eighty three (42%) of those without repair (p < 0.05). There was no significant difference for pain, function, ROM, MCS and complication rates (p < 0.05). The mean operating time of deltoid ligament repair groups was 20 minutes longer than non-repair groups(p < 0.05). Deltoid ligament repair offers significantly lower syndesmotic malreduction rates and reduced re-operation rates for hardware removal when performed instead of transsyndesmotic screw fixation. When compared to non-repair groups, there are no significant differences in pain, function, ROM, MCS and complication rates. Deltoid ligament repair should be considered for ankle fracture patients with syndesmotic injury, especially those with Weber C. Other alternative syndesmotic fixation methods such as suture button fixation should be explored. A large multi-patient randomized control trial is required to further examine the outcomes of ankle fracture patients with deltoid ligament repair

Introduction. Recent literature has shown that RSAs successfully improve pain and functionality, however variability in range of motion and high complication rates persist. Biomechanical studies suggest that tensioning of the deltoid, resulting from deltoid lengthening, improves range of motion by increasing the moment arm. This study aims to provide clinical significance for deltoid tensioning by comparing postoperative range of motion measurements with deltoid length for 93 patients. Methods. Deltoid length measurements were performed radiographically for 93 patients. Measurements were performed on both preoperative and postoperative x-rays in order to assess deltoid lengthening. The deltoid length was measured as the distance from the infeolateral tip of the acromion to the deltoid tuberosity on the humerus for both pre- and post- x-rays. For preoperative center of rotation measurements, the distance extended from the center of humeral head (estimated as radius of best fit circle) to deltoid length line. For postoperative measurements, the distance was from the center of glenosphere implant to deltoid length line. Forward flexion and external rotation was measured for all patients. Results. The average preoperative deltoid length was 154.25 mm while the average postoperative deltoid measurements was 178.93 mm. The average preoperative center of rotation as 21.33 mm and the average postoperative center of rotation measurement was 46.75 mm. There was low correlation between deltoid length and center of rotation with either forward flexion or external rotation or outcome scores. Discussion. Our results suggest that deltoid lengthening does not significantly influence optimizing clinical outcomes for RSAs. Further research is required to determine design parameters and implants positioning to improve RSAs

Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the in vivo measured surgical placement to determine muscle activation and normalized operating region for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied from the RTSA subject's nominal surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction. Overall muscle activity varied over 1521 different implant configurations for the RTSA subject. For initial elevation the RTSA subject showed at least 25% deltoid activation sensitivity in each of the directions of joint configuration change(Figure 1). Posterior deltoid showed a maximal activation variation of 84% in the superior/inferior direction(Figure 1c). Deltoid activation variations lie primarily in the superior/inferior and anterior/posterior directions. An increasing trend was seen for the anterior, lateral and posterior deltoid outside of the discontinuity seen at 28°(Figure 1). Activation variations were compared to subject's experimental data. Reserve actuation for all samples remained below 4Nm(Figure 2). The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions(Figure 3). Current shoulder models utilize cadaver information in their assessment of generic muscle strength. In adding to this literature we performed a sensitivity study to assess the effects of RTSA joint configurations on deltoid muscle performance in a single patient-specific model. For this patient we were able to assess the best joint configuration to improve the patients muscle function and ideally their clinical outcome. With this information improvements can be made to the surgical placement and design of RTSA on a patient-specific basis to improve functional/clinical outcomes while minimizing complications. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Reverse total shoulder arthroplasty (RTSA) is an increasingly common treatment for osteoarthritic shoulders with irreparable rotator cuff tears. Although very successful in alleviating pain and restoring some function, there is little objective information relating geometric changes imposed by the reverse shoulder and arm function, particularly the moment generating capacity of the shoulder muscles. Recent modeling studies of reverse shoulders have shown significant variation in deltoid muscle moment arms over a typical range of humeral offset locations in shoulders with RTSA. The goal of this study was to investigate the sensitivity of muscle moment arms as a function of varying the joint center and humeral offset in three representative RTSA subjects that spanned the anatomical range from our previous study cohort. We hypothesized there may exist a more beneficial joint implant placement, measured by muscle moment arms, compared to the actual surgical implant configuration. A 12 degree of freedom, subject-specific model was used to represent the shoulders of three patients with RTSA for whom fluoroscopic measurements of scapular and humeral kinematics during abduction had been obtained. The computer model used subject-specific in vivo abduction kinematics and systematically varied humeral offset locations over 1521 different perturbations from the surgical placement to determine moment arms for the anterior, lateral and posterior aspects of the deltoid muscle. The humeral offset was varied from its surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction. The anterior deltoid moment arm varied up to 20 mm with humeral offset and center of rotation variations, primarily in the medial/lateral and superior/inferior directions. Similarly, the lateral deltoid moment arm demonstrated variations up to 20 mm, primarily with humeral offset changes in the medial/lateral and anterior/posterior directions. The posterior deltoid moment arm varied up to 15mm, primarily in early abduction, and was most sensitive to changes of the humeral offset in the superior/inferior direction. The goal of this study was to assess the sensitivity of the deltoid muscle moment arms as a function of joint configuration for existing RTSA subjects. High variations were found for all three deltoid components. Variation over the entire abduction arc was greatest in the anterior and lateral deltoid, while the posterior deltoid moment arm was mostly sensitive to humeral offset changes early in the abduction arc. Moment arm changes of 15–20 mm represent a significant amount of the total deltoid moment arm. This means there is an opportunity to dramatically change the deltoid moment arms through surgical placement of the joint center of rotation and humeral stem. Computational models of the shoulder may help surgeons optimize subject-specific placement of RTSA implants to provide the best possible muscle function, and assist implant designers to configure devices for the best overall performance

Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the in vivo measured surgical placement to determine muscle activation and normalized operating region for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied from the RTSA subject's nominal surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction. Overall muscle activity varied over 1521 different implant configurations for the RTSA subject. For initial elevation the RTSA subject showed at least 25% deltoid activation sensitivity in each of the directions of joint configuration change(Figure 1A–C). Posterior deltoid showed a maximal activation variation of 84% in the superior/inferior direction(Figure 1C). Deltoid activation variations lie primarily in the superior/inferior and anterior/posterior directions(Figure 1). An increasing trend was seen for the anterior, lateral and posterior deltoid outside of the discontinuity seen at 28°(Figur 1A–C). Activation variations were compared to subject's experimental data (Figure 1). Reserve actuation for all samples remained below 4Nm. The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions. Current shoulder models utilize cadaver information in their assessment of generic muscle strength. In adding to this literature we performed a sensitivity study to assess the effects of RTSA joint configurations on deltoid muscle performance. With this information improvements can be made to the surgical placement and design of RTSA to improve functional/clinical outcomes while minimizing complications

Reverse total shoulder arthroplasty (RTSA) is an increasingly common treatment for osteoarthritic shoulders with irreparable rotator cuff tears. Although very successful in alleviating pain and restoring some function there is little objective information relating geometric changes imposed by the reverse shoulder and the moment generating capacity of the shoulder muscles. Recent modeling studies of reverse shoulders have shown significant variation in deltoid muscle moment arms over varied joint centers for shoulders with RTSA. The goal of this study was to investigate the sensitivity of muscle moment arms as a function of varying the joint center in one representative RTSA subject. We hypothesized there may exist a more beneficial joint implant placement, measured by muscle moment arms, compared to the actual surgical implant placement. A 12 degree of freedom, subject-specific model was used to represent the shoulder of a patient with RTSA for whom fluoroscopic measurements of scapular and humeral kinematics during abduction had been obtained. The computer model used these abduction kinematics and systematically varied joint center locations over 1521 different perturbations from the surgical placement to determine moment arms for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied from its surgical position ±4 mm in the anterior/posterior direction, 0–24 mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction. The anterior deltoid moment arm varied up to 16mm with center of rotations variations, primarily in the medial/lateral and superior/inferior directions (Figure 2, Table 1(Figure 1)). Similarly, the lateral deltoid moment arm demonstrated variations up to 13 mm, primarily with joint center changes in the anterior/posterior and superior/inferior directions. The posterior deltoid moment arm varied up to 10mm, primarily in early abduction, and was most sensitive to changes of the joint center in demonstrated a sensitivity of 6 mm corresponding to variations in the superior/inferior directions (Figure 2). The goal of this study was to assess the sensitivity of the deltoid muscle moment arms as a function of joint configuration for an existing RTSA subject. High variations were found for all three deltoid components. Variation over the entire abduction arc was greatest in the anterior and lateral deltoid, while the posterior deltoid moment arm was mostly sensitive to joint center changes early in the abduction arc. Moment arm changes of 10–16mm represent a significant amount of the total deltoid moment arm. This means there is an opportunity to dramatically change the deltoid moments arms through surgical placement of the joint center of rotation. Computational models of the shoulder may help surgeons optimize subject-specific placement of RTSA implants to provide the best possible muscle function, and assist implant designers to configure devices for the best overall performance

Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the in vivo measured surgical placement to determine muscle normalized operating region for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied according to previous published work from the RTSA subject's nominal surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction (Walker 2015 et al. Table 2). Overall muscle normalized operating length varied over 1521 different implant configurations for the RTSA subject. Ideal muscle normalized operating length variations were found to be in all the fundamental directions that the joint was varied. The anterior deltoid normalized operating length was found to be most sensitive with joint configurations changes in the anterior/posterior medial/lateral direction. It lateral deltoid normalized operating length was found to be most sensitive with joint configurations changes in the medial/lateral direction. It posterior deltoid normalized operating length was found to be most sensitive with joint configurations changes in the medial/lateral direction. Reserve actuation for all samples remained below 1 Nm. The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions. Current shoulder models focus on predicting muscle moment arms. Although valuable it does not allow me for active understanding of how lengthening the muscle will affect its ability to generate force. Our study provides an understanding of how muscle lengthening will affect the force generating capacity of each of the heads of the deltoid. With this information improvements can be made to the surgical placement and design of RTSA to improve functional/clinical outcomes while minimizing complications. For any figures or tables, please contact the authors directly

Background:. An upper extremity model of the shoulder was developed from the Stanford upper extremity model (Holzbaur 2005) in this study to assess the muscle lengthening changes that occur as a function of kinematics for reverse total shoulder athroplasty (RTSA). This study assesses muscle moment arm changes as a function of scapulohumeral rhythm (SHR) during abduction for RTSA subjects. The purpose of the study was to calculate the effect of RTSA SHR on the deltoid moment arm over the abduction activity. Methods:. The model was parameterized as a six degree of freedom model in which the scapula and humeral rotational degrees of freedom were prescribed from fluoroscopy. The model had 15 muscle actuators representing the muscles that span the shoulder girdle. The model was then uniformly scaled according to reflective markers from motion capture studies. An average SHR was calculated for the normal and RTSA cohort set. The SHR averages were then used to drive the motion of the scapula and the humerus. Lastly 3-dimensional kinematics for the scapula and humerus from 3d-2d fluoroscopic image registration techniques were used to drive the motion of model. Deltoid muscle moment arm was calculated. Results:. Muscle moment arms were calculated for the anterior, lateral and posterior heads of the deltoid. Significant changes (>1 mm) were only found in comparing the anterior deltoid muscle moment arm predictions between the normal and RTSA group. The anterior deltoid for RTSA had a moment arm range from −12.5–20.6 mm over the max abduction arc. The anterior deltoid for normal group had a moment arm range from −14.5–22.6 mm over the max abduction arc. There is a difference of 2 mm between the normal and RTSA anterior deltoid moment arm that converges to 0 at 45° of elevation. The 2 mm difference is also seen again as the difference diverges again (Figure 1). There were no significant differences found between normal and RTSA groups for the lateral and posterior deltoid. The most significant difference between moment arm calculations for the RTSA and normal group was found in the Anterior deltoid. (Figure 1). Conclusion:. It was found that the muscle moment arms in the RTSA group were significantly different than in the normal group for the anterior deltoid. No other significant differences were found. In the initial 40° of elevation there is a 2 mm difference in anterior deltoid muscle moment arm between the normal and RTSA group. This difference is also found is seen from 60°–90° of elevation. From 35° −55° there is no difference between RTSA and normal groups. SHR for the RTSA (1.8: 1) is significantly lower than in the normal (2.5: 1) group. Differences found in muscle moment arms over the abduction arc between RTSA and normal groups point to the significant change of the anterior deltoid after RTSA. This study primary objective was to assess the differences in muscle moment arms as a function of SHR (Kinematic differences). Significant differences found may improve implant design, surgical technique, and rehabilitative strategies for reverse shoulder surgery

The Delto-pectoral approach is the workhorse of the shoulder surgeon, but surprisingly the common variants of the cephalic vein and deltoid artery have not been documented. The vascular anatomy encountered during one hundred primary elective delto-pectoral approaches was documented and common variants described. Two common variants are described. A type I (71%), whereby the deltoid artery crosses the interval and inserts directly in to the deltoid musculature. In this variant the surgeon is unlikely to encounter any vessels crossing the interval apart from the deltoid artery itself. In a type II pattern (21%) the deltoid artery runs parallel to the cephalic vein on the deltoid surface and is highly likely to give off medial branches (95%) that cross the interval, as well as medial tributaries to the cephalic vein (38%). Knowledge of the two common variants will aid the surgeon when dissecting the delto-pectoral approach and highlights that these vessels crossing the interval are likely to be arterial, rather than venous. This study allows the surgeon to recognize these variations and reproduce bloodless, safe and efficient surgery

Reverse total shoulder arthroplasty (RTSA) is increasingly used in the United States since approval by the FDA in 2003. RTSA relieves pain and restores mobility in arthritic rotator cuff deficient shoulders. Though many advantages of RTSA have been demonstrated, there still are a variety of complications (implant loosening, shoulder impingement, infection, frozen shoulder) making apparent much still is to be learned how RTSA modifies normal shoulder function. The goal of this study was to assess how RTSA affects deltoid muscle moment generating capacity post-surgery using a subject-specific computational model driven by in vivo kinematic data. A subject-specific 12 degree-of-freedom (DOF) musculoskeletal model was used to analyze the shoulders of 27 subjects (14-RTSA, 12-Normal). The model was modified from the work of Holzbaur et al. to directly input 6 DOF humerus and scapula kinematics obtained using fluoroscopy. Model geometry was scaled according to each subject's skeletal dimensions. In vivo abduction kinematics for each subject were input to their subject-specific model and muscle moment arms for the anterior, lateral and posterior aspects of the deltoid were measured over the arc of motion. Similar patterns of muscle moment arm changes were observed for normal and RTSA shoulders. The moment arm of the anterior deltoid was positive with the arm at the side and decreased monotonically, crossing zero (the point at which the muscle fibers pass across the joint center) between 50°–60° glenohumeral abduction (Figure 1a). The average moment arm of the lateral deltoid was constant and positive in normal shoulders, but showed a decreasing trend with abduction in RTSA shoulders (Figure 1b). The posterior deltoid moment arm was negative with the arm at the side, and increased monotonically to a positive value with increasing glenohumeral abduction (Figure 1c). Subject-specific moment arm values for RTSA shoulders were highly variable compared to normal shoulders. 2-way repeated measures ANOVA showed significant differences between RTSA and normal shoulders for all three aspects of the deltoid moment arm, where the moment arms in RTSA shoulders were smaller in magnitude. Shoulder functional capacity is a product of the moment generating ability of the shoulder muscles which, in turn, are a function of the muscle moment arms and muscle forces. Placement of implant components during RTSA can directly affect the geometric relationship between the humerus and scapula and, therefore, the muscle moment arms in the RTSA shoulder. Our results show RTSA shoulders maintain the same muscle moment arm patterns as healthy shoulders, but they show much greater inter-subject variation and smaller moment arm magnitudes. These observations show directly how RTSA configuration and implant placement affect deltoid moment arms, and provide an objective basis for determining optimal implant configuration and surgical placement to maximize RTSA function in a patient-specific manner

Treatment of proximal humerus fractures (PHF) is controversial in many respects, including the choice of surgical approach for fixation when using a locking plate. The classic deltopectoral (DP) approach is believed to increase the risk of avascular necrosis while making access to the greater tuberosity more difficult. The deltoid split (DS) approach was developed to respect minimally invasive surgery principles. The purpose of the present study (NCT-00612391) was to compare outcomes of PHF treated by DP and DS approaches in terms of function (Q-DASH, Constant score), quality of life (SF12), and complications in a prospective randomized multicenter study. From 2007 to 2016, all patients meeting the inclusion/exclusion criteria in two University Trauma Centers were invited to participate in the study. Inclusion criteria were: PHF Neer II/III, isolated injury, skeletal maturity, speaking French or English, available for follow-up (FU), and ability to fill questionnaires. Exclusion criteria: Pre-existing pathology to the limb, patient-refusing or too ill to undergo surgery, patient needing another type of treatment (nail, arthroplasty), axillary nerve impairment, open fracture. After consent, patients were randomized to one of the two treatments using the dark envelope method. Pre-injury status was documented by questionnaires (SF12, Q-DASH, Constant score). Range of motion was assessed. Patients were followed at two weeks, six weeks, 3-6-12-18-24 months. Power calculation was done with primary outcome: Q-DASH. A total of 92 patients were randomised in the study and 83 patients were followed for a minimum of 12 months. The mean age was 62 y.o. (+- 14 y.) and 77% were females. There was an equivalent number of Neer II and III, 53% and 47% respectively. Mean FU was of 26 months. Forty-four patients were randomized to the DS and 39 to the DP approach. Groups were equivalent in terms of age, gender, BMI, severity of fracture and pre-injury scores. All clinical outcome measures were in favor of the deltopectoral approach. Primary outcome measure, Q-DASH, was better statistically and clinically in the DP group (12 vs 26, p=0,003). Patients with DP had less pain and better quality of life scores than with DS (VAS 1/10 vs 2/10 p=0,019 and SF12M 56 vs 51, p=0,049, respectively). Constant-Murley score was higher in the DP group (73 vs 60, p=0,014). However, active external rotation was better with the DS approach (45° vs 35°). There were more complications in DS patients, with four screw cut-outs vs zero, four avascular necrosis vs one, and five reoperations vs two. Calcar screws were used for a majority of DP fixations (57%) vs a minority of DS (27%) (p=0,012). The primary hypothesis on the superiority of the deltoid split incision was rebutted. Functional outcome, quality of life, pain, and risk of complication favoured the classic deltopectoral approach. Active external rotation was the only outcome better with DS. We believe that the difficulty of adding calcar screws and intramuscular dissection in the DS approach were partly responsible for this difference. The DP approach should be used during Neer II and III PHF fixation

Our purpose was to study the functional outcome and electrophysiologically to assess the axially nerve function in patients who have undergone surgery using a deltoid-splitting approach to treat complex proximal humeral fractures. This was a prospective observational study and was carried out in the Shoulder injury clinic at a university teaching hospital. Over a one-year period we treated fourteen locally-resident patients (median age 59 years) who presented with a three- or four-part proximal humeral fracture. All patients were treated using the extended deltoid-splitting approach, with open reduction, bone grafting and plate osteosynthesis. All patients were prospectively reviewed and underwent functional testing using the DASH, Constant and SF-36 scores as well as spring balance testing of deltoid power, and dynamic muscle function testing. At one year after surgery, all patients underwent EMG and nerve latency studies to assess axillary nerve function. Thirteen of the fourteen patients united their fractures without complications, and had DASH and Constant score that were good, with comparatively minor residual deficits on assessment of muscle power. Of these thirteen patients, only one had evidence of slight neurogenic change in the anterior deltoid. This patient had no evidence of anterior deltoid paralysis and her functional scores, spring balance and dynamic muscle function test results were indistinguishable from the patients with normal electrophysiological findings. One of the fourteen patients developed osteonecrosis of the humeral head nine months after surgery and had poor functional scores, without evidence of nerve injury on electrophysiological testing. Reconstruction through an extended deltoid-splitting approach provides a useful alternative in the treatment of complex proximal humeral fractures. The approach provides good access for reduction and implant placement and does not appear to be associated with clinically-significant adverse effects

Ideberg-Goss type VI/AO F2(4) glenoid fossa fractures are a rare and complex injury. Although some advocate non-operative management, grossly displaced glenoid fossa fractures in the young patient may warrant fixation. Current approaches still describe difficulty with access of the entirety of the glenoid, particularly the postero-superior quadrant.

We present 2 cases of Ideberg-Goss type VI/AO F2(4) glenoid fossa fractures treated with fixation through a novel “Deltoid Takedown” approach, which allows safe access to the whole glenoid with satisfactory clinical results at 5 and 7 years respectively.

Abstract

Optimal surgical management of proximal humeral fractures remains controversial. We report our experience and the study on our surgical technique for proximal humeral fractures and fracture-dislocations using locking plates in conjunction with calcium sulphate augmentation and tuberosity repair using high strength sutures. We used the extended deltoid-splitting approach for fracture patterns involving displacement of both lesser and greater tuberosities and for fracture-dislocations.

We retrospectively analysed 22 proximal humeral fractures in 21 patients. 10 were male and 11 female with an average age of 64.6 years (Range 37 to 77). Average follow-up was 24 months. Fractures were classified according to Neer and Hertel systems. Pre-operative radiographs and CT scans in three and four-part fractures were done to assess the displacement and medial calcar length for predicting the humeral head vascularity. According to the Neer classification, there were 5 two-part, 6 three-part, 5 four-part fractures and 6 fracture-dislocations (2 anterior and 4 posterior). Results were assessed clinically with DASH scores, modified Constant & Murley scores and serial post-operative radiographs.

The mean DASH score was 16.18 and modified Constant & Murley score was 64.04 at the last follow-up. 18 out of 22 cases achieved good clinical outcome. All the fractures united with no evidence of infection, failure of fixation, malunion, tuberosity failure, avascular necrosis or adverse reaction to calcium sulphate bone substitute. There was no evidence of axillary nerve injury. The CaSO4 bone substitute was replaced by normal appearing trabecular bone texture at an average of 6 months in all patients.

Despite reverse total shoulder arthroplasty (RTSA) being primarily indicated for massive rotator cuff tears, it is often possible to repair portions of the infraspinatus and subscapularis of patients undergoing this procedure. However, there is disagreement regarding whether these tissues should be repaired, as their effects remain unclear. Therefore, we investigated the effects of rotator cuff repair and changes in humeral and glenosphere lateralisation (HLat & GLat) on deltoid and joint loading. Six shoulders were tested on an in-vitro muscle driven active motion simulator. Cuff tear arthropathy was simulated in each specimen, which was then implanted with a custom adjustable RTSA fitted with a six axis load sensor. We assessed the effects of 4 RTSA configurations (i.e. all combinations of 0&10mm of HLat & GLat) on deltoid force, joint load, and joint load angle during abduction with/out rotator cuff repair. Deltoid and joint loads recorded by the load cell are reported as a % of Body Weight (%BW). Repeated measures ANOVAs and pairwise comparisons were performed with p<0.05 indicating significance. Cuff repair interacted with HLat & GLat (p=0.005, Fig. 1) such that with no HLat, GLat increased deltoid force without cuff repair (8.1±2.1%BW, p=0.012) and this effect was significantly increased with cuff repair (12.8±3.2%BW, p=0.010). However, adding HLat mitigated this such that differences were not significant. HLat and GLat affected deltoid force regardless of cuff status (−2.5±0.7%BW, p=0.016 & +7.7±2.3%BW, p=0.016, respectively). Rotator cuff repair did significantly increase joint load (+11.9±2.1%BW, p=0.002), as did GLat (+13.3±1.5%BW, p<0.001). The increases in deltoid and joint load caused by rotator cuff repair confirm that it acts as an adductor following RTSA and increases deltoid work. Additionally, cuff repair's negative effects are exacerbated by GLat, which strengthens its adduction affect, while Hlat increases the deltoid's abduction effect thus mitigating the cuff's antagonistic effects. Cuff repair increases concavity compression within the joint; however, Hlat produces a similar effect by wrapping the deltoid around the greater tuberosity – which redirects its force – and does so without increasing the magnitude of muscle and joint loading. The long-term effects of increased joint loading due to rotator cuff repair are unknown, however, it can be postulated that it may increase implant wear, and the risk of deltoid fatigue. Therefore, RTSA implant designs which improve joint compression without increasing muscle and joint loading may be preferable to rotator cuff repair

Surgeries for reverse total shoulder arthroplasty (RTSA) significantly increased in the last ten years. Initially developed to treat patients with cuff tear arthropathy (CTA) and pseudoparalysis, wider indications for RTSA were described, especially complex proximal humerus fractures. We previously demonstrated in patients with CTA a different sequence of muscular activation than in normal shoulder, with a decrease in deltoid activation, a significant increase of upper trapezius activation and slight utility of the latissimus dorsi. There is no biomechanical study describing the muscular activity in patients with RTSA for fractures. The aim of this work is to describe the in vivo action of RTSA in patients with complex fractures of the proximal humerus. We conducted an observational prospective cohort study comparing 9 patients with RTSA for complex humerus fracture (surgery more than 6 months, healed tuberosities and rehabilitation process achieved) and 10 controls with normal shoulder function. Assessment consisted in a synchronized analysis of range of motion (ROM) and muscular activity on electromyography (EMG) with the use of 7 bipolar cutaneous electrodes, 38 reflective markers and 8 motion-recording cameras. Electromyographic results were standardized and presented in muscular activity (RMS) adjusted with maximal isometric contractions according to the direction tested. Five basic movements were evaluated (flexion, abduction, neutral external rotation, external rotation in 90° of abduction and internal rotation in 90° of abduction). Student t-test were used for comparative descriptive analysis (p < 0,05). The overall range of motion with RTSA is very good, but lower than the control group: flexion 155.6 ± 10 vs 172.2 ± 13.9, p<0.05, external rotation at 90° 55.6 ± 25 vs 85.6 ± 8.8, p<0,05, internal rotation at 90° 37.8 ± 15.6 vs 52.2 ± 12, p<0,05. The three heads of the deltoid are more stressed during flexion and abduction in the RTSA group (p. The increased use of the 3 deltoid chiefs does not support the hypothesis proposed by Grammont when the RTSA is performed for a complex proximal humerus fracture. This can be explained by the reduced dispalcement of the rotation center of the shoulder in these patients compared to those with CTA. These patients also didn't present shoulder stiffness before the fracture. The maximal muscle activity of the trapezius in flexion and of the latissimus dorsi in flexion and abduction had not been described to date. These new findings will help develop better targeted rehabilitation programs. In addition, the significant role of the latissimus dorsi must question the risks of its transfer (L'Episcopo procedure) to compensate for external rotation deficits

Introduction:. Reverse total shoulder arthroplasty (RTSA) has become instrumental in relieving pain and returning function to patients with end-stage rotator cuff disease. A distalized and medialized center of rotation in addition to a semi-constrained implant design allows the deltoid to substitute for the non-functioning rotator cuff. The purpose of this study was to examine the relationship between specific deltoid and rotator cuff muscle parameters and functional outcomes following RTSA. Methods:. Patients undergoing RTSA by a single surgeon were enrolled in a prospective, IRB approved RTSA outcomes registry. Inclusion criteria were diagnosis of cuff tear arthropathy or massive rotator cuff tear, a minimum 2-year follow-up, and a preoperative shoulder MRI. We excluded patients undergoing revision arthroplasty, fracture, and a history of previous open shoulder surgery. For the 28 patients meeting our criteria, the cross-sectional area (CSA) of the anterior, middle, and posterior deltoid were measured on an axial MRI (Figure 1). Fatty infiltration (FI) of the deltoid, supraspinatus (SS), infraspinatus (IS), teres minor, and subscapularis were assessed on sagittal T1-MRI quantitatively via image processing and qualitatively on the 5-point Fuchs scale by a fellowship-trained musculoskeletal radiologist. Outcome measures included active forward elevation (aFE), active external rotation (aER), active internal rotation (aIR), strength in abduction, Constant-Murley score (CMS), Subjective Shoulder Value (SSV), Visual Analogue Scale (VAS) pain, and American Shoulder and Elbow Surgeons (ASES) total and ASES activities of daily living (ADL) scores as assessed by a trained, clinical research nurse. Correlation of deltoid CSA and FI with outcomes measures was analyzed with a Spearman rank correlation coefficient (ρ) with significance at P < .05. Results:. The correlations between preoperative deltoid size and quantitative deltoid FI to postoperative function are shown in Table 1. The total deltoid CSA showed the most significant, positive correlations with outcome measures. The anterior deltoid CSA showed the strongest correlation to postoperative strength in abduction. Quantitative FI of the deltoid was negatively associated with several outcome measures (Table 1). Quantitative FI of the SS and IS demonstrated a significant negative correlation with aER (ρ = −.732, P = .039 and ρ = −.790, P = .004, respectively). The grade of FI, as assessed using the Fuchs scale, did not correlate to any clinical outcome data. Discussion and Conclusion:. Preoperative deltoid size and FI of the deltoid and the rotator cuff muscles correlate to 2-year functional outcomes following RTSA. The anterior, posterior, and total CSA of the deltoid had significant, positive associations with several outcome measures, whereas FI of the deltoid, SS, and IS had significant, negative associations, particularly with humeral rotation. In the future, optimization of deltoid and rotator cuff muscle function preoperatively may improve functional outcomes in RTSA

The standard approach is through the deltopectoral interval. Among patients with prior incisions, one makes every effort to either utilise the old incision or to incorporate it into a longer incision that will allow one to approach the deltopectoral interval and retract the deltoid laterally. The deltopectoral interval is most easily developed just distal to the clavicle, where there is a natural infraclavicular triangle of fat that separates the deltoid and pectoralis major muscles even in very scarred or stiff shoulders. Typically, the deltoid is retracted laterally leaving the cephalic vein on the medial aspect of the exposure. The anterior border of the deltoid is mobilised from the clavicle to its insertion on the humerus. The anterior portion of the deltoid insertion together with the more distal periosteum of the humerus may be elevated slightly. The next step is to identify the plane between the conjoined tendon group and the subscapularis muscle. Dissection in this area must be done very carefully due to the close proximity of the neurovascular group, the axillary nerve, and the musculocutaneous nerve. Scar is then released from around the base of the coracoid. The subacromial space is freed of scar and the shoulder is examined for range of motion. Particularly among patients with prior rotator cuff surgery, there may be severe scarring in the subacromial space. Internal rotation of the arm with dissection between the remaining rotator cuff and deltoid is critical to develop this plane. If external rotation is less than 30 degrees, one can consider incising the subscapularis off bone rather than through its tendinous substance. For every 1 cm that the subscapularis is advanced medially, one gains approximately 20 to 30 degrees of external rotation. The rotator interval between the subscapularis and supraspinatus is then incised. This release is then continued inferiorly to incise the inferior shoulder capsule from the neck of the humerus. This is performed by proceeding from anterior to posterior with progressive external rotation of the humerus staying directly on the bone with electrocautery and great care to protect the axillary nerve. The key for glenoid exposure as well as improvement in motion is deltoid mobilization, a large inferior capsular release, aggressive humeral head cut and osteophyte removal

Massive irreparable rotator cuff tears often lead to superior migration of the humeral head, which can markedly impair glenohumeral kinematics and function. Although treatments currently exist for treating such pathology, no clear choice exists for the middle-aged patient demographic. Therefore, a metallic subacromial implant was developed for the purpose of restoring normal glenohumeral kinematics and function. The objective of this study was to determine this implant's ability in restoring normal humeral head position. It was hypothesized that (1) the implant would restore near normal humeral head position and (2) the implant shape could be optimized to improve restoration of the normal humeral head position. A titanium implant was designed and 3D printed. It consisted of four design variables that varied in both implant thickness (5mm and 8mm) and curvature of the humeral articulating surface (high constraint and low constraint. To assess these different designs, these implants were sequentially assessed in a cadaver-based biomechanical testing protocol. Eight cadaver specimens (64 ± 13 years old) were loaded at 0, 30, and 60 degrees of glenohumeral abduction using a previously developed shoulder simulator. An 80N load was equally distributed across all three deltoid heads while a 10N load was applied to each rotator cuff muscle. Testing states included a fully intact rotator cuff state, a posterosuperior massive rotator cuff tear state (cuff deficient state), and the four implant designs. An optical tracking system (Northern Digital, Ontario, Canada) was used to record the translation of the humeral head relative to the glenoid in both superior-inferior and anterior-posterior directions. Superior-Inferior Translation. The creation of a posterosuperior massive rotator cuff tear resulted in significant superior translation of the humeral head relative to the intact cuff state (P=0.016). No significant differences were observed between each implant design and the intact cuff state as all implants decreased the superior migration of the humeral head that was observed in the cuff deficient state. On average, the 5mm low and high constraint implant models were most effective at restoring normal humeral head position to that of the intact cuff state (-1.3 ± 2.0mm, P=0.223; and −1.5 ± 2.3mm, P=0.928 respectively). Anterior-Posterior Translation. No significant differences were observed across all test states for anterior-posterior translation of the humeral head. The cuff deficient on average resulted in posterior translation of the humeral head, however, this was not statistically significant (P=0.128). Both low and high constraint implant designs were found to be most effective at restoring humeral head position to that of the intact cuff state, on average resulting in a small anterior offset (5mm high constraint: 2.0 ± 4.7mm, P=1.000; 8mm high constraint: 1.6 ± 4.9mm, P=1.000). The 5mm high constraint implant was most effective in restoring normal humeral head position in both the superior-inferior and anterior-posterior directions. The results from this study suggest the implant may be an effective treatment for restoring normal glenohumeral kinematics and function in patients with massive irreparable rotator cuff tears. Future studies are needed to address the mechanical efficiency related to arm abduction which is a significant issue related to patient outcomes