Background. Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures. Aim. To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability. Methods. Four matched pairs (8 specimens) were tested using a standardised protocol. Specimens were sequentially tested for stability when axially loaded with a custom rig with up to 750N. Specimens were tested with: ankle intact; lateral injury (AITFL and Weber B); additional posterior injury (PITFL); additional anterior deep deltoid; additional posterior deep deltoid; lateral side ORIF. Clinical photographs and radiographs were recorded. In addition, dynamic stress radiographs were performed after sectioning the deep deltoid and then after fracture fixation to assess tilt of the talus in eversion. Results. All specimens with an intact posterior deep deltoid ligament were stable when loaded and showed no talar tilt on dynamic assessment. Once the posterior deep deltoid ligament was sectioned there was instability in all specimens. Surgical stabilisation of the lateral side prevented talar shift but not talar tilt. Conclusion. If the posterior deep deltoid ligament is intact SER fractures may be managed without surgery in a plantigrade cast. Without immobilisation the talus may tilt, risking deltoid incompetence

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

Physiological studies have revealed that the central nervous system controls groups of muscle fibers in a very efficient manner. Within a single skeletal muscle, the central nervous system independently controls individual muscle segments to produce a particular motor outcome. Mechanomyographic studies on the deltoid muscle have revealed that the deltoid muscle, commonly described as having three anatomical segments, is composed of at least seven functional muscle segments, which all have the potential to be at an important level independently coordinated by the central nervous system.[. 1. ] In this study we tried to anatomically describe and quantify these different functional segments within the deltoid muscle, based on the branching out pattern of the axillary nerve. Forty-four deltoids of 22 embalmed adult cadavers, were analyzed. The axillary nerve was carefully dissected together with his anterior and posterior branch upon invasion into the muscle. According to the pattern of fiber distribution and their fascial embalmment, we then carefully splitted the deltoid muscle into different portions each being innervated by a major branch of the axillary nerve. The position and volume of each segment in relation to the whole muscle was derived. In 3 cases the axillary nerve branched out in 8 major divisions. In 22 out of 44 cases (50%), the axillary nerve branched out in 7 principal parts. A branching out pattern of 6 major divisions occurred in 14 out of 44 cases. Finally we found a division in 5 major branches in 5 of the specimens. In general, both posterior and anterior peripheral segments seemed to have the largest volume. In nearly all (93%) cases, the central segments were smaller in weight and volume compared to the more peripheral segments. Based on the innervation pattern of the deltoid muscle a segmentation in 5 up to 8 major segments seem to be found. This confirms from anatomical point of view earlier reports of functional differentiation within the deltoid muscle

The surgical technique for treatment of massive rotator cuff tears, more than 5 cm, with loss of substance and tendon retraction, is still not well defined by the international orthopaedic community. A specific rehabilitation regimen or arthroscopic débridement may be insufficient in active patients who continue to suffer from pain and muscular fatigue in active forward elevation. We treated 20 patients, 14 men and 6 women, with an average age of 52 years (range 40–69) with the surgical technique consisting in acromion decompression, stabilisation of the cuff lesion with anchors, application of a prolene membrane and using a deltoid muscular flap as reinforcement. Deltoid flap is created by splitting the deltoid muscular fibres in front of the anterior border of the acromion. The inferior part of deltoid is sutured to the tendon above the synthetic membrane. The mean patient follow-up was 24 months. The pain was completely relieved in 85% of subjects, The joint mobility increased significantly in flexion, abduction and external rotation; however, the internal rotation did not improve. We propose this surgical technique as the procedure of choice for treating retracted ruptures of the supraspinatus associated with lesions of the supra- and the infra-spinatus

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

Introduction: Massive irreparable degenerative rotator cuff tears are amongst the most difficult conditions for treatment in shoulder surgery. These involve usually elderly patients, which present with severely painful and restricted active shoulder movement. These patients have low demand from their shoulders, mainly for pain relief and performing their simple activities of daily living. Major surgery for major tendon transfer will not be advisable in these cases in view of the morbidity involved and the questionable outcome. We suggest a simple non-surgical rehabilitation treatment consisting on anterior deltoid strengthening exercises in the supine position for re-education of the anterior deltoid to compensate for the absent rotator cuff. Methods: 17 patients with degenerative (non traumatic) Massive irreparable rotator cuff tears were recruited. They were all greater than 70 years of age and of mixed gender. Patients were English speaking, had full mental faculties and gave informed consent. They suffered no other shoulder pathology and were not participants in any other upper limb rehabilitation. All patients complained on severe shoulder pain and severely limited active range of motion with inability to actively elevate the arm to the horizontal. They all had full passive range of motion. The diagnosis of a Massive irreparable rotator cuff tear was confirmed by diagnostic ultrasound scan. The shoulder function was evaluated using the Constant Score. Patients’ active shoulder ranges of motion were recorded and video-recorded as well. Each participant was taught the initial 6-week of self Deltoid muscle exercise, executed in supine, at least three times a day. They were instructed that when they felt better control on their active shoulder movements to gradually recline up the head of the bed and continue with the same simple exercise. They were reviewed at 6 weeks re-assessed and re-taught the same exercise, with a 2kg weight in their hand. At the 12th week they were reassessed using the constant score, and their active range of motion was video recorded again. Results: 90% of the participants expressed a significant improvement in their upper limb function already after 6 weeks of treatment. All components of the Constant score (beside the strength) have improved. 90% reported less pain and found general activities of daily living easier to execute and a diminished level of muscle fatigue. 10% of the patients were able to establish a recording of > 1.26kg on the myometer in 90 degrees of abduction. 10% failed to report any benefit. Discussion and Conclusion: Anterior deltoid strengthening exercises in the supine position for re-education of the anterior deltoid seem to have a significant beneficial effect for restoration of shoulder function and pain relief in the majority of patients with Massive irreparable degenerative rotator cuff tears. Using this simple non-invasive rehabilitation technique helps to re-educate the anterior deltoid to compensate for the absent rotator cuff and restore shoulder function

Proximal humeral fractures are common fractures that may lead to severe functional disability. In open reduction and internal fixation of these fractures deltopectoral approach is pereferred by many surgeons being an internervous plane and because of familiarity. However when this aprroach is used extensive soft tissue dissection is inevitable and control of the commonly displaced tuberculum majus fragment which is displaced posterolateraly is difficult. In this prospective study we compared deltopectoral and lateral deltoid splitting approach by using the same fixation material. Between October 2005 and March 2007 42 patients were included in the study group. In Group A a lateral deltoid split approch and in Group B deltopectoral approach was used. Group A consisted of 22 cases; mean age 60.95 (26–90 years old); 12 female and 10 male, Group B 20 cases; mean age 56.9 (24–86 years old); 13 female, 7 male. Philos locking plate fixation (Synthes) was used in every case. When deltoid split approach was used axillary nerve was explored and protected, a C-arm was used in every case. Functional results and compications were compared at the follow up visits. When radiological results were compared the reduction of head and tubercular fragments were better in deltoid splitting approach. The Constant score was better in Group A at an earlier time period 68.9 vs 58.4 (p< 0.01). At the 6th month follow up the difference between Constant scores was not significant, 85.9 vs 85.2 (p> 0.05). Axillary nerve lesion due to lateral deltoid split exposure was not observed in any of the cases. Lateral deltoid split exposure with identification and protection of the axillary nerve facilitates 270 degrees control of the head and tubercular fragments in AO/ASIF type B and C fractures. Additional fixation of tubercular fragments by sutures passed through cuff tendons and fixed to the plate helps to maintain the reduction. Compared to double incision minimal invasive approach a shother plate is used without any inadvertant risk to the axillary nerve. Better Constant scores are achieved at an earlier time. We recommend this technique in AO/ASIF type B and C fractures

Tear pattern and tendon involvement are risk factors for the development of a pseudoparalytic shoulder. However, some patients have similar tendon involvement but significantly different active forward flexion. In these cases, it remains unclear why some patients suffer from pseudoparalysis and others with the same tear pattern show good active range of motion. Moment arms (MA) and force vectors of the RC and the deltoid muscle play an important role in the muscular equilibrium to stabilize the glenohumeral joint. Biomechanical and clinical analyses were conducted calculating different MA-ratios of the RC and the deltoid muscle using computer rigid body simulation and a retrospective radiographic investigation of two cohorts with and without pseudoparalysis and massive RC tears. Idealized MAs were represented by two spheres concentric to the joints centre of rotation either spanning to the humeral head or deltoid origin of the acromion. Individual ratios of the RC /deltoid MAs on antero-posterior radiographs using the newly introduced Shoulder Abduction Moment (SAM) Index was compared between the pseudoparalytic and non-pseudoparalytic patients. Decrease of RC activity and improved glenohumeral stability (+14%) was found in simulations for MA ratios with larger diameters of the humeral head which also were consequently beneficial for the (remaining) RC. Clinical investigation of the MA-ratio showed significant risk of having pseudoparalysis in patients with massive tears and a SAM Index <0.77 (OR=11). The SAM index, representing individual biomechanical characteristics of shoulder morphology has an impact on the presence or absence of pseudoparalysis in shoulders with massive RC tears

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

Objective: The deltoid ligament is an important stabilising structure in the ankle joint. We hypothesised that ultrasound can be used to allow early clinical assessment of ankle fracture stability accurately and quickly in Weber B and C ankle fractures thereby negating the need to perform arthrograms intra-operatively. Method: A total of 20 patients were recruited prospectively. Consent was obtained prior to surgery. Patients with Weber B or C fractures requiring surgery were recruited prospectively. Following induction of anaesthesia, ultrasound examination was performed, followed by an arthrogram under fluoroscopic screening. Operating surgeons were blinded to results. Radiographs, ultrasound and arthrographic findings were compared by a panel of orthopaedic surgeons of varying grades (2 Consultants, 2 Specialist Registrars). Results: There was 95% correlation between ultrasound and arthrogram findings. Ultrasound accurately diagnosed rupture with a sensitivity of 92% and specificity of 100%. Kappa scores for ultrasound identification of deltoid rupture was 0.8. Conclusion: We feel ultrasound exam to be a powerful adjunct tool in the management and operative planning of ankle fractures. Its versatility means it can be used in Emergency Departments and Trauma Clinics to assess ankle stability without causing the patient excessive pain and requiring an anaesthetic

The aim of this study was to evaluate and compare the results of acromioplasty in two groups of patients operated upon for impingement syndrome using two different techniques, In one group the insertion of the devoid was partially divided (deltoid off strategy) while in the other the insertion of the deltoid was preserved (deltoid on strategy). Twenty-one patients, suffering from impingement syndrome of the shoulder, were operated during the period 1996–2001. Preoperatively all patients presented with positive impingement test and they were complaining of night pain as well as pain during activity. Two different techniques were used. In 2 group of 10 patients. the “deltoid off’”strategy was applied and the acromioplasty was performed with the use of an osteotome. In a second group of 11 patients the “deltoid on” strategy was applied and the acrormioplasty was performed by using a high speed burr. Eight out of 10 patients of the first group were satisfied with the results of the operation, whereas all the 11 patients of the second group were satisfied. The return to full activity in patients with the “deltoid off” strategy was 10 weeks in average, while in the “deltoid on” group it was 8 weeks. Night pain subsided in ail patients in both groups. Two patients of the first group complained of mild pain with daily living activities, while 10 out of the 11 patients of the second group had no pain at all. Finally 2 patients of the first group and none of the second group presented residual painful arc. We conclude that the “deltoid on” technique for treatment of the impingement syndrome of the shoulder appears more simple and reliable, has less morbidity and gives better clinical results, compared to the “deltoid off” technique