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Summary Background Using the subpectoral approach, animation deformity or breast distortion due to pectoralis muscle contraction is common. Although the anatomy of the pectoral nerves has been extensively studied, only few studies have related the location of these nerves to bony landmarks. Objective Our aim is to clarify the anatomy and possible variations of the innervation of the pectoralis major in relation to bony landmarks useful for surgery and to identify the preferred level for (selective) denervation by 1) transecting the nerves and 2) splitting the muscle in subpectoral breast implant surgery in cadavers. Methods Fourteen pectoral regions (both left and right side) were dissected on 7 formaldehyde-fixed cadavers. The origin, locations, and course were mapped and (distances to) landmarks were reported. Results The lateral pectoral nerve, medial pectoral nerve, and ansa pectoralis were identified in all cadavers. Nerve branches pierce the pectoralis minor or run along its upper or lower border. The piercing nerves vary from one to three branches and were consistently located lateral to the midclavicular line. The horizontal and vertical distances to bony landmarks varied greatly and depended on the size and location of the pectoralis minor, except for the nerve running along the upper border of the PMin, which was located consistently around 30% of the clavicular line from the acromioclavicular joint to the sternoclavicular joint. Conclusion We were unable to define a fixed landmark to mark pre- or peroperatively. However, we could define guidelines that help to identify and excise or preserve nerves of interest.

The shoulder is structurally and functionally complex. Shoulder pain may be refractory to conventional treatments, such as physical therapy, pharmacotherapy, and corticosteroid injections. In such cases, radiofrequency ablation may serve as an alternative treatment plan. Current literature has demonstrated 4 target nerves for ablative therapy: the suprascapular nerve, axillary nerve, lateral pectoral nerve, and subscapular nerve. Special caution is needed when targeting these nerves in order to avoid motor denervation. This article summarizes the current evidence for radiofrequency ablation as a useful treatment option for chronic shoulder pain as well as the described techniques for performing this promising procedure.

Background and objectives Muscular variations of the ventral thoracic wall are generally common and of great clinical interest. Materials and methods An unusual muscular variation of the ventral thoracic wall was observed and dissected in a West-European female body donor. Results An interclavicularis anticus digastricus muscle was observed and studied. It originated from the manubrium sterni and inserted bilaterally to the clavicles. Both muscle bellies were interconnected by a tendon on the ventral surface of the manubrium sterni. The muscle was innervated by branches of the lateral pectoral nerve. Conclusions The interclavicularis anticus digastricus muscle is a muscular variation of the ventral thoracic wall of unknown prevalence. This variation might be of clinical interest in orthopaedics and thoracic surgery. It is also a vulnerable structure during infraclavicular insertion of a subclavian vein catheter or fractures of the clavicle.

Shoulder pain is prevalent, burdensome, and functionally limiting, with diverse pathology and associated treatments. This narrative review provides a summary of relevant neuroanatomy, proposed ablation targets, safety and efficacy concerns for ablation targets, and current research gaps. Radiofrequency ablation (RFA) of peripheral sensory nerves is a well-established treatment for chronic joint and spine pain, but it is relatively nascent for shoulder pain. Cadaveric studies demonstrate the shoulder joint is innervated by articular branches of the suprascapular nerve, axillary nerve, lateral pectoral nerve, and upper and lower subscapular nerves. Shoulder articular branch RFA appears to be a safe and effective treatment for chronic shoulder pain, but there are currently no widely accepted protocols for ablation targets. There are also no randomized controlled trials (RCT) assessing safety and efficacy of proposed targets or the prognostic value of articular blocks. Future research studies should prioritize categorical data, use appropriate functional measures as primary endpoints, and would ideally include a large-scale RCT.

OBJECTIVENerve transfers are commonly used in treating complete injuries of the brachial plexus, but donor nerves are limited and preferentially directed toward the recovery of elbow flexion and shoulder abduction. The aims of this study were to characterize the anatomical parameters for identifying the nerve to the levator scapulae muscle (LSN) in brachial plexus surgery, to evaluate the feasibility of transferring this branch to the suprascapular nerve (SSN) or lateral pectoral nerve (LPN), and to present the results from a surgical series.METHODSSupra- and infraclavicular exposure of the brachial plexus was performed on 20 fresh human cadavers in order to measure different anatomical parameters for identification of the LSN. Next, an anatomical and histomorphometric evaluation of the feasibility of transferring this branch to the SSN and LPN was made. Lastly, the effectiveness of the LSN-LPN transfer was evaluated among 10 patients by quantifying their arm adduction strength.RESULTSThe LSN was identified in 95% of the cadaveric specimens. A direct coaptation of the LSN and SSN was possible in 45% of the specimens (n = 9) but not between the LSN and LPN in any of the specimens. Comparison of axonal counts among the three nerves did not show any significant difference. Good results from reinnervation of the major pectoral muscle (Medical Research Council grade ≥ 3) were observed in 70% (n = 7) of the patients who had undergone LSN to LPN transfer.CONCLUSIONSThe LSN is consistently identified through a supraclavicular approach to the brachial plexus, and its transfer to supply the functions of the SSN and LPN is anatomically viable. Good results from an LSN-LPN transfer are observed in most patients, even if long nerve grafts need to be used.

BackgroundThis cadaveric study investigated the innervations of the clavicle and clavicular joints (ie, sternoclavicular and acromioclavicular joints).MethodsTwenty cadavers (40 clavicles) were dissected. A skin incision was made to permit exposure of the posterior cervical triangle and infraclavicular fossa. The platysma, sternocleidomastoid, and trapezius muscles were cleaned in order to identify the supraclavicular nerves. Subsequently, the suprascapular and subclavian nerves were localized after removal of the prevertebral layer of the deep cervical fascia. In the infraclavicular region, the pectoralis major and minor muscles were retracted laterally in order to visualize the lateral pectoral nerve. The contribution of all these nerves to the clavicular bone and joints were recorded.ResultsAlong their entire length, all clavicular specimens received contributions from the supraclavicular nerves. The latter innervated the cephalad and ventral aspects of the clavicular bone. The caudal and dorsal aspects of the clavicle were innervated by the subclavian nerve (middle and medial thirds). The lateral pectoral nerve supplied the caudad aspect of the clavicle (middle and lateral thirds). The sternoclavicular joint derived its innervation solely from the supraclavicular nerves whereas the acromioclavicular joint was supplied by the supraclavicular and lateral pectoral nerves.ConclusionThe clavicle and clavicular joints are innervated by the subclavian, lateral pectoral, and supraclavicular nerves. Clinical trials are required to determine the relative importance and functional contribution of each nerve.

The main objective was to examine practice patterns of phenol neurolysis for post-stroke spasticity management in the early stage. We performed a chart review of patients who were admitted for inpatient rehabilitation within 6 months after first-ever stroke and received phenol neurolysis within 15 months post-stroke. Out of 2,367 stroke admissions from January 2014 and December 2018, 68 patients met the criteria. 52.9% of these patients received phenol neurolysis within 12 weeks, i.e., early stage. The earliest phenol neurolysis procedure was at 19 days after stroke. On average, patients received first phenol injections at 16.3 weeks after stroke with an average dose of 7.3 ml. Most commonly injected nerves were tibial nerve motor branches (41/68), sciatic nerve motor branches (37/68), lateral pectoral nerve (16/68), medial pectoral nerve (15/68), obturator nerve (15/68) and musculocutaneous nerve (15/68). Among 68 patients, 24 received phenol only; 17 received phenol neurolysis first followed by botulinum toxin (BoNT) injections; 19 received BoNT injections first followed by phenol neurolysis; 8 received both phenol and BoNT injections at the same time. The interval from stroke to first procedure was similar between the Phenol-First group (13.3 weeks) and the BoNT-First group (12.6 weeks). The total amount of BoNT was significantly lower in the Phenol-First group (361.3 units) than in the BoNT-First group (515.8 units) (p = 0.005). The total amount of phenol was not statistically different between the Phenol-First group (5.9 ml) and the BoNT-First group (8.3 ml). The interval between the first procedure and its subsequent procedure was not statistically different between the Phenol-First group (18.3 weeks) and the BoNT-First group (10.7 weeks). These long intervals suggest that the subsequent injection (type and dose) was not planned during the first procedure. The general patterns of target areas were similar between BoNT injections and phenol neurolysis, except that phenol neurolysis rarely targeted the upper extremity distal muscles. No side effects after phenol or BoNT injections in the early stage after stroke were observed in the chart review. In summary, phenol neurolysis was started as early as 19 days after stroke. On average, patients received first phenol about 4 months after stroke with an average of 7.3 ml of phenol. Early use of phenol neurolysis likely decreases the total amount of BoNT for management of post-stroke spasticity without increased side effects.

Spasticity is common and difficult to manage complication of cerebral palsy that significantly affects the function and quality of life of patients. This case study reports a 15-year-old male with quadriplegic cerebral palsy, Gross Motor Function Classification System 5 (GMFCS 5), who presented with significant bilateral adducted and internally rotated shoulders as a component of generalized spasticity. Spasticity in the lower limb of the patient had been treated with botulinum toxin A (BoNT-A) injections; however, the shoulder region was spared due to concerns of toxin spread and aspiration risk. Following diagnostic nerve blocks, the patient underwent bilateral cryoneurotomies of the right and left lateral pectoral nerves (LPNs) lasting 3.5 min for each lesion. One month after the cryoneurotomies, the range of motion (ROM) had improved from 86° to 133° on the right and 90° to 139° on the left. Improvements in ROM were retained at 9 months post-procedure. At 8.5 months following the cryoneurotomies, the caregiver reported improvements in upper body dressing, upper body washing, transferring, and the ability of the patient to remain sitting in his wheelchair for extended periods. Cryoneurotomy may be an effective procedure for improving shoulder ROM and specific functional outcomes for caregivers of patients with spasticity arising from cerebral palsy.

Purpose: This randomized noninferiority trial aimed to evaluate whether combined suprascapular, axillary nerve, and the articular branch of lateral pectoral nerve block (3NB) is noninferior to interscalene nerve block (ISB) for pain control after arthroscopic rotator cuff repair (ASRCR). Materials and Methods: Eighty-five patients undergoing ASRCR were randomized to either 3NB (n = 43) or ISB (n = 42) group. We used 5 and 15 ml of 0.2% ropivacaine for each nerve in the 3NB and ISB groups, respectively. The primary outcome was the visual analog scale (VAS) pain score at 4 h postoperatively measured assessed on an 11-point scale (ranging from 0 = no pain to 10 = worst pain) that was analyzed using noninferiority testing. The secondary outcome was VAS pain scores in the recovery room and at 8, 12, 24, 36, 48, and 72 h postoperatively. Rebound pain, IV-PCA usage during 48 h, dyspnea, muscle weakness, and satisfaction were evaluated. Results: Regarding the primary outcome, the mean difference in VAS pain scores between the 3NB (2.5 ± 1.6) and ISB (2.2 ± 2.3) groups at 4 h postoperatively was 0.3, with a 95% confidence interval (CI) of −0.56 to 1.11. The upper limit of 95% CI is lower than the noninferiority margin of 1.3 ( p < 0.001). At all other time points, except in the recovery room, 3NB showed noninferior to ISB. Rebound pain, IV-PCA usage during the second 24 h, and muscle weakness were lower in the 3NB group (all p < 0.005). The satisfaction was similar in both groups ( p = 0.815). Conclusion: Combined 3NB is noninferior to ISB in terms of pain control after ASRCR; and is associated with low levels of rebound pain, IV-PCA usage, and muscle weakness. Level of evidence: Randomized controlled trial, Level I.

Summary: Background/Objective: The aim of this study was to evaluate with electromyography (EMG) the effect of lateral pectoral nerve sparing technique (LPNST) and radiotherapy (RT) on the lateral pectoral nerve (LPN) in patients applied with modified radical mastectomy (MRM). Methods: The study included 66 patients who underwent MRM surgery. The patients were separated into 2 groups as those applied with LPNST and those who underwent standard surgery (Control group). Within these 2 groups, patients were again separated as those who received or did not receive RT. The EMG evaluations were made by a neurology specialist blinded to the patient groups. Results: The mean age of the patients was 53.3 ± 10.6 years. Standard surgery was applied to 33 (50%) patients and LPNST to 33 (50%) patients, RT was applied to 32 (48.5%) patients and not to 34 (51.5%) patients. In the EMG evaluation, latency was 2.1 ms (1.4–3.2) in the LPNST and 3.7 ms (1.9–12.4) in the control (p < 0.001) and amplitude values were 9650 mV (3120–36900) in the LPNST and 4780 mV (510–12.4) in the control (p < 0.001). The latency values in the Control receiving and not receiving RT were 4.0 ms (1.9–12.4) and 2.6 ms (1.9–6.2) respectively (p < 0.05). The latency values of the patients receiving and not receiving RT in the LPNST were 2.2 ms (1.8–3.2) and 2.0 ms (1.4–2.4) respectively (p < 0.05). In the Control and LPNST Group, no significant difference was determined between receiving and not receiving RT groups in respect of amplitude values (p > 0.05). Conclusion: The results of this study demonstrated that electromyographically the latency and amplitude values were better protected in the LPNST group. It was also seen that RT increased the formation of nerve damage in both groups. Keywords: Modified radical mastectomy, Radiotherapy, Electromyography, Lateral pectoral nerve, Pectoralis major muscle

Purpose: To assess the feasibility of total shoulder denervation through two proposed incisions. Methods: Total shoulder denervation was performed through an extended delta-pectoral approach and a transverse dorsal approach at the spine of the scapula. The study involved six cadavers. Course and number of articular branches from the lateral pectoral, axillary and supra-scapular nerve were documented. Results: All shoulder joint articular branches were accessible through the proposed anterior and posterior approaches. The articular branch of the lateral pectoral nerve and supra scapular nerve were present in all the specimen. Axillary nerve articular branches were variable in number but when present anteriorly were proximal to the deltoid muscular branches and posteriorly proximal to the muscular branches to the teres minor. Conclusion: Total glenohumeral denervation was feasible through our proposed anterior and posterior approaches. Enhanced knowledge of articular nerve branches could provide interventional targets for joint and ligament pain, with low risk of muscle weakness., SCOPUS: ar.j, info:eu-repo/semantics/published

Introduction: Pectoralis minor (PMi) is used as a vascularized and innervated free-muscle graft in the reconstructive surgical procedure. The present review aims to provide insights to the surgeons regarding the variants of PMi in terms of costal attachment, insertion, nerve supply and arterial supply. Methodology: Three major databases (PubMed, EMBASE, and Google Scholar) were thoroughly searched along with the full text of journals. Results: Seven studies (n = 1787) were analysed for the evaluation of costal attachment. PMi arise from 3rd to 5th rib in 33% (95% confidence interval [CI], 30–37%), but the most common variants II-5 ribs was observed in 36%, which was higher than normal. Eighteen studies (n = 2424) reported details of insertion. The variant insertion of PMi was observed in 21% (15–28; 95% CI). Seven studies reported nerve supply. Both medial pectoral nerve (MPN) and lateral pectoral nerve (LPN) innervates PMi in 93% and MPN absent in 7%. Only two studies reported arterial supply. The PMi was vascularized by single dominant artery in 77% (68–85; 95% CI) or two arteries in 19% (13–29; 95% CI) or three arteries 2% (2–8; 95% CI) or even four arteries in 1% (0–7; 95% CI). Conclusion: PMi has a constant costal attachment to the 3rd and 4th ribs. Origin of PMi from 5th rib is reported with a pooled prevalence of 73.3% and from 2nd rib is reported in 61.5%. PMi inserts to the superomedial boundary of the coracoid process in 79% only.

The pectoralis major (PM) flap is a Mathes–Nahai type V flap (one major pedicle, multiple minor pedicles). While it is very useful in the reconstruction of the head and neck, as well as sternal reconstruction, these indications are beyond the scope of this book and will not be discussed. When it comes to extremity reconstruction, the uses of the pectoralis major flap are limited, since there are other options in the armamentarium of the plastic surgeon. We prefer to use this flap mainly for pedicled functional muscle transfer to restore the deltoid function whenever other options are not available. The PM flap has also been utilized as a functional muscle flap to restore FDP function following Volkmann’s ischemic contracture of the forearm; however, we feel that an innervated gracilis muscle flap is technically easier and results in a negligible donor deficit, making the gracilis muscle the flap of choice in our practice for FDP function restoration. Anatomically, the pectoralis major muscle can be divided into three anatomically distinct portions: the clavicular portion, the sternal portion, and the costal portion (Fig. 16.1). The PM flap can be harvested as a split muscle flap, thus maintaining some of the function and minimizing the donor deficit, or as a whole muscle, most commonly when used for head and neck reconstruction. We prefer to harvest the clavicular and sternal portion of the flap, leaving the costal portion attached to the humerus to allow adequate functionality. The pectoralis major muscle allows for (1) flexion of the humerus, (2) adduction of the humerus, (3) medial rotation, and (4) stabilization of the humerus. The PM flap is usually based off of the thoracoacromial pedicle and if preservation of functionality is desired, the lateral pectoral nerve is preserved. Main disadvantages of the flap include the short pedicle (only 3 cm) and the aesthetically non-pleasing donor side defect, especially in females.

Background and objectivesAcromial branches of the lateral pectoral and suprascapular nerves have been proposed as targets for diagnostic block and radiofrequency ablation to treat superior shoulder pain; however, the nerve capture rates of these procedures have not been investigated. The objectives of this study were to use dissection and 3D modeling technology to determine the course of these acromial branches, relative to anatomical landmarks, and to evaluate nerve capture rates using ultrasound-guided dye injection and lesion simulation.MethodsUltrasound-guided dye injections, targeting the superior surface of coracoid process and floor of supraspinous fossa, were performed (n=5). Furthermore, needles targeting the superior and posterior surfaces of the coracoid process were placed under ultrasound guidance to simulate needle electrode position (n=5). Specimens were dissected, digitized, and modeled to determine capture rates of acromial branches of lateral pectoral and suprascapular nerves.ResultsThe course of acromial branches of lateral pectoral and suprascapular nerves were documented. Dye spread capture rates: acromial branches of lateral pectoral and suprascapular nerves were captured in all specimens. Lesion simulation capture rates: (1) when targeting superior surface of coracoid process, the entire acromial branch of lateral pectoral nerve was captured in all specimens and (2) when targeting posterior surface of coracoid process, the acromioclavicular and bursal branches of acromial branch of suprascapular nerve were captured in all specimens; coracoclavicular branch was captured in 3/5 specimens.ConclusionsThis study supports the anatomical feasibility of ultrasound-guided targeting of the acromial branches of lateral pectoral and suprascapular nerves. Further clinical investigation is required.

Background Pectoralis I and II (Pecs I/Pecs II) blocks are modern regional anesthetic techniques performed in combination to anesthetize the nerves involved in breast surgery and axillary node dissection. Pecs II spread and clinical efficacy is thought to be independent of whether injection occurs between pectoralis minor and serratus anterior or deep to serratus anterior. Injecting deep to serratus anterior onto the rib may be technically easier; however, our clinical experience suggests that this approach may be less effective for axillary dissection. We undertook a cadaveric study to evaluate a subserratus plane approach for use in breast and axillary surgery. Methods Ultrasound-guided blocks using methylene blue dye were performed on 4 Genelyn-embalmed cadavers to assess and compare dye spread after a conventional Pecs II and a subserratus plane block at the third rib. Results Conventional Pecs II injection demonstrated staining of the intercostobrachial nerve, third intercostal nerve, thoracodorsal nerve, long thoracic nerve, medial pectoral, and lateral pectoral nerve. The subserratus plane produced significantly less axillary spread, incomplete staining of the medial pectoral, and very minimal staining of the lateral pectoral nerve. Dye spread was limited to the lateral cutaneous branches of the intercostal nerves in both injections. Conclusions In our cadaveric study, injecting deep to serratus plane produced significantly less axillary spread. For breast surgery excluding the axilla, both techniques may be effective; however, for axillary dissection, the conventional Pecs II is likely to produce superior analgesia and additionally may help achieve complete coverage of the deeper pectoral nerve branches.

Purpose To assess the proximity of neurovascular structures in a layered approach during medial portal placement and determine standardized measurements for establishing a portal medial to the coracoid used in arthroscopic Latarjet-type procedures. Methods Twelve shoulders (6 right and 6 left) in 6 fresh frozen cadaveric torsos were mounted in the modified beach-chair position. A standard posterior portal and 3 anterior portals—central, lateral, and medial—were used. A long spinal needle was placed along the path of the medial portal to the lateral tip of the coracoid, superficial to the conjoined tendon and pectoralis minor. A second long spinal needle was directed toward the medial base of the coracoid, penetrating the pectoralis minor. Superficial and deep plane dissections were performed, and distances to surrounding neurovascular structures were recorded. Results In the superficial plane, the cephalic vein and lateral pectoral nerve were located a mean distance (± standard deviation) of 4.6 ± 1.9 mm and 9.4 ± 2.6 mm from the spinal needle, respectively. In the deep plane, the axillary nerve was 24.9 ± 7.4 mm from the needle; the lateral cord of the brachial plexus, 25.5 ± 8.1 mm; the axillary artery, 34.1 ± 6.0 mm; and the musculocutaneous nerve, 42.2 ± 9.2 mm. The portal was consistently established 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the coracoid, which was a minimum distance of 10 mm to the lateral pectoral nerve. Conclusions In a cadaveric model, the creation of a medial trans–pectoralis major portal used in the arthroscopic Bankart-Bristow-Latarjet procedure can avoid compromise of vital neurovascular structures, alleviating concerns of creating a portal medial to the coracoid. Portal placement 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the palpable tip of the coracoid process may be a safe approach to perform the arthroscopic Bankart-Bristow-Latarjet procedure. Clinical Relevance Creation of a portal medial to the level of the coracoid may pose a risk to neurovascular structures. This cadaveric study establishes a working zone for medial trans-pectoralis portal placement, which avoids vital neurovascular structures, and provides standardized measurements for establishing this portal for use in the arthroscopic Bankart-Bristow-Latarjet procedure.

INTRODUCTION: The innervation pattern of the clavicular head of the deltoid muscle and its corresponding topography were investigated via cadaveric dissection in the present study, focusing on the lateral pectoral nerve. MATERIALS AND METHODS: Fifty-eight upper extremities were dissected and the nerve supplies to the deltoid muscle and the variability of the lateral pectoral and axillary nerves, including their topographical patterns, were noted. RESULTS: The clavicular portion of the deltoid muscle received a deltoid branch from the lateral pectoral nerve in 86.2% of cases. Two topographical patterns of the lateral pectoral nerve were observed, depending on the branching level from the brachial plexus: a proximal variant, where the nerve entered the pectoral region undern the clavicle, and a distal variant, where the nerve entered the pectoral region from the axillary fossa around the caudal border of the pectoralis minor. These dissection findings were supported by histological confirmation of peripheral nerve tissue entering the clavicular part of the deltoid muscle. CONCLUSION: The topographical variations of the lateral pectoral nerve are relevant for orthopedic and trauma surgeons and neurologists. These new data could revise the interpretation of deltoid muscle atrophy and of thoracic outlet and pectoralis minor compression syndromes. They could also explain the residual anteversion function of the arm after axillary nerve injury and deficiency, which is often thought to be related to biceps brachii muscle function.

Clavicle fractures correspond to 35% of traumatic fractures of the shoulder girdle. Regional anaesthesia has shown better analgesic results than systemic treatment for perioperative management. Innervation of the clavicle is complex, at present its knowledge raises controversy. The lateral pectoral nerve through the innervating musculature predominantly participates in the lateral and anterior part of the clavicle. The following report of 7 cases describes the effective postoperative analgesia of modified PEC II block in patients with middle third clavicle fracture or acromioclavicular dislocation who underwent a modified PEC II block for postoperative pain management, in the context of a multimodal analgesia. The potential advantage of this management over other analgesic procedures should be evaluated in specific clinical trials.

Clavicle fractures correspond to 35% of traumatic fractures of the shoulder girdle. Regional anaesthesia has shown better analgesic results than systemic treatment for perioperative management. Innervation of the clavicle is complex, at present its knowledge raises controversy. The lateral pectoral nerve through the innervating musculature predominantly participates in the lateral and anterior part of the clavicle. The following report of 7 cases describes the effective postoperative analgesia of modified PEC II block in patients with middle third clavicle fracture or acromioclavicular dislocation who underwent a modified PEC II block for postoperative pain management, in the context of a multimodal analgesia. The potential advantage of this management over other analgesic procedures should be evaluated in specific clinical trials.

Brachial plexus is complex network of nerves, formed by joining and splitting of ventral rami of spinal nerves C5, C6, C7, C8, and T1 forming trunks, divisions, and cords. The nerves emerging from trunks and cords innervate the upper limb and to some extent pectoral region. Scanty literature describes the variations in the formation of cords and nerves emanating from them. Moreover, the variations of cords of brachial plexus and nerves emanating from them have iatrogenic implications in the upper limb and pectoral region. Hence study has been carried out. Twenty-eight upper limbs and posterior triangles from 14 cadavers fixed in formalin were dissected and rare and new variations of cords were observed. Most common variation consisted of formation of posterior cord by fusion of posterior division of upper and middle trunk and lower trunk continued as medial cord followed by originating of 2 pectoral nerves from anterior divisions of upper and middle trunk. Other variations include anterior division of upper trunk continued as lateral cord and pierced the coracobrachialis, upper and middle trunk fused to form common cord which divided into lateral and posterior cords, upper trunk gave suprascapular nerve and abnormal lateral pectoral nerve and formation of median nerve by 3 roots. These variations were analyzed for diagnostic and clinical significance making the study relevant for surgeons, radiologists in arresting failure patients and anatomists academically in medical education.

The lateral pectoral nerve (LPN) innervates anterior shoulder structures. We report a novel technique for radiofrequency ablation (RFA) of the articular branch of the LPN (abLPN) to treat persistent anterior shoulder pain. Ultrasound and fluoroscopy were used to identify bony and vascular landmarks to target the midlateral and superior-lateral coracoid process (CP). Multiple thermal RFA lesions were delivered along this location without complication using a 20-gauge cannula. As a result, the patient has continued substantial relief of resting and dynamic deep anterior shoulder pain beyond 3 months. Ablation of the abLPN may provide anterior shoulder analgesia without causing motor weakness.

The Pecs I, Pecs II and Serratus Plane blocks are superficial thoracic wall blocks which through blockade of the pectoral, intercostal, thoracodorsal and long thoracic nerves can be used to provide analgesia for breast surgery and other procedures/surgery involving the anterior chest wall. The innervation of the breast is supplied mainly by the anterior branches of the 4th, 5th and 6th intercostal nerves which arise from the thoracic spinal nerves (T4-6). the apex of the axilla is supplied by the intercostobrachialis nerve; this is a cutaneous branch of the second intercostal nerve (T2). the pectoral major and minor muscles are innervated by the lateral pectoral nerve (C5-7) and medial pectoral nerve (C8-T1). Terminal branches of the supraclavicular nerves (C3-4) innervate the upper part of the breast and this should be taken into account when the surgical procedure involves this area, because Pecs blocks will not block the supraclavicular nerve. Breast surgery however, is rarely performed at this level. The long thoracic nerve (C5-7) supplies the serratus anterior muscle. the thoracodorsal nerve (C6-8) supplies latissimus dorsi and this is relevant for more extensive procedures. The lateral cutaneous branches of the thoracic intercostal nerves (T2 – T9) together with the long thoracic and the thoracodorsal nerves can be found in a compartment space between serratus anterior and latissimus dorsi between the posterior and mid axillary lines. Local anaesthetic is placed between the muscles of the thoracic wall, using ultrasound guidance.

Variations in the distribution of the lateral cord and its branches in the infraclavicular part of the brachial plexus are common and significant to the neurologists, surgeons, anaesthetists and the anatomists [1]. The present case describes a rare variation of the lateral pectoral nerve giving an additional branch to supply biceps brachii muscle and ends by joining inferior collateral branch of brachial artery. Also it was observed that the musculo cutaneous nerve received communicating branches from the median nerve before and after piercing the coracobrachialismuscle. The above observations were observed during routine dissection of a 55 year old Indian male cadaver. The musculocutaneous nerve, lateral pectoral nerve and its branches were identified and protected. The clinical importance of the variation is discussed.

Background and objectivesIn 2011, chronic shoulder joint pain was reported by 18.7 million Americans. Image-guided radiofrequency ablation has emerged as an alternative intervention to manage chronic shoulder joint pain. To optimize the effectiveness of shoulder denervation, it requires a detailed understanding of the nerve supply to the glenohumeral and acromioclavicular joints relative to landmarks visible with image guidance. The purpose of this cadaveric study was to determine the origin, course, relationships to bony landmarks, and frequency of articular branches innervating the glenohumeral and acromioclavicular joints.MethodsFifteen cadaveric specimens were meticulously dissected. The origin, course, and termination of articular branches supplying the glenohumeral and acromioclavicular joints were documented. The frequency of each branch was determined and used to generate a frequency map that included their relationships to bony and soft tissue landmarks.ResultsIn all specimens, the posterosuperior quadrant of the glenohumeral joint was supplied by suprascapular nerve; posteroinferior by posterior division of axillary nerve; anterosuperior by superior nerve to subscapularis; and anteroinferior by main trunk of axillary nerve. Less frequent innervation was found from lateral pectoral nerve and posterior cord. The acromioclavicular joint was found to be innervated by the lateral pectoral and acromial branch of suprascapular nerves in all specimens. Bony and soft tissue landmarks were identified to localize each nerve.ConclusionsThe frequency map of the articular branches supplying the glenohumeral and acromioclavicular joints, as well as their relationship to bony and soft tissue landmarks, provide an anatomical foundation to develop novel shoulder denervation and perioperative pain management protocols.

Background and Objectives The popularization of ultrasound-guided nerve blocks in cosmetic and reconstructive breast surgery calls for better anatomical understanding of chest wall innervation. When inserting subpectoral implants, pain from pocket dissection, stretching of muscle, and release of costal attachments may be relieved by blocking the pectoral nerves in the interpectoral (IP) space. We describe the variable anatomy of the pectoral nerves in the IP space in order to define the area to be covered for sufficient blockade, based on cadaver dissections. Methods Twenty-six fresh cadavers were dissected bilaterally. The number, location, and course of the pectoral nerves were recorded. Distances to surface landmarks (sternum, clavicle, and costae) and ultrasound landmarks (thoracoacromial artery [TAA] and pectoralis minor muscle [Pm]) were recorded. Results The lateral pectoral nerve and the TAA entered together into the IP space 8.9 cm (range, 8.0–12.0 cm) lateral to the midsternal line. The medial pectoral nerve (MPN) had between 1 and 4 branches that pierced the Pm, and 69% had additional branches lateral to the Pm. The muscle-piercing MPN branches were located 3.8 cm (range, 0.4–8.1 cm) and the lateral MPN branches 5.4 cm (range, 3.0–8.4 cm) from the lateral pectoral nerve. The IP course was 2.6 cm (range, 0.7–6.5 cm). All specimens were asymmetrical in location or number of MPN branches. Conclusions The MPN branches that innervate the lower part of the pectoralis major muscle are asymmetrical and variable in location and length; all located in a triangular area easily defined by sonographic landmarks, lateral to the TAA.

The abdominal head of the pectoralis major (AHPM) is important in cosmetic and flap surgeries. Few studies have reported on its neurovascular entry points and distribution patterns. We aimed to determine the entry points and distribution patterns of the neurovascular structures within the AHPM. Thirty-two hemithoraxes were dissected, and the distribution patterns of the neurovascular structures were classified into several categories. The neurovascular entry points were measured at the horizontal line passing through the jugular notch (x-axis) and the midclavicular line (y-axis). The AHPM was innervated by the communication branches of the medial pectoral nerve (MPN) and the lateral pectoral nerve (LPN) in 78.1% of the specimens and of the MPN without the communication branches in 21.9%. All the LPNs had communication branches, which could be classified as independent in 46.9% of the samples, with the MPN in 21.9%, and with the LPN in 9.3%. The blood supply of the AHPM was composed of branches from the lateral thoracic artery (LTA) in 62.5% of the specimens, the thoracoacromial artery (TA) in 15.6%, and the LTA with the TA in 21.9%. The mean distance of the entry point was 6.3 cm ± 1.3 cm lateral to the y-axis, 8.1 cm ± 3.3 cm below the x-axis in the nerves, 6.5 cm ± 1.2 cm lateral to the y-axis, and 8.6 cm ± 3.0 cm below the x-axis in the arteries. This study defined the average neurovascular entry point and distribution pattern in detail using standard lines to enable the AHPM to be better understood. Clin. Anat. 28:520–526, 2015. © 2015 Wiley Periodicals, Inc.

The knowledge of innervation of pectoral muscles is important to surgeons performing breast surgeries, axillary lymph node dissection, harvesting pectoralis major/minor for flaps, and during neurotization procedures where the pectoral nerves are particularly at risk. The present case describes the innervation of the pectoral muscles solely by a nerve trunk arising from the ansa pectoralis (AP) - the loop of medial and lateral pectoral nerves. Interestingly, there was also a communication between the AP and roots forming the median nerve. It is imperative for the operating surgeons to be aware of these rare variations in order to prevent denervation and subsequent atrophy of the pectoral musculature.

Background: Lipomas are common benign tumors. When they develop in proximity to peripheral nerves, they can cause neurologic symptoms secondary to mass effect. Previous reports have shown symptom resolution after removal of lipomas compressing various upper extremity peripheral nerves. However, brachial plexus lipomas are relatively rare. Our multidisciplinary experience with brachial plexus lipoma resection is reviewed in the largest case series to date. Methods: A retrospective chart review of all patients undergoing resection of brachial plexus lipomatous tumors between 2006 and 2016 was performed. Patient demographic data, diagnostic imaging, clinical presentation, operative details, surgical pathology, and clinical outcomes were reviewed. Results: Twelve brachial plexus lipomatous tumors were resected in 11 patients: 10 lipomas, 1 hibernoma, and 1 atypical lipomatous tumor. The most common tumor location was supraclavicular (50%), followed by axillary (42%), and proximal medial arm (8%). The most common brachial plexus segment involved was the upper trunk (50%), followed by posterior cord (25%), lateral pectoral nerve (8%), lower trunk (8%), and proximal median nerve (8%). Most patients presented with an enlarging painless mass (58%). Of the patients who presented with neurologic symptoms, symptoms resolved in the majority (80%). Conclusions: Brachial plexus lipomas are rare causes of compression neuropathy in the upper extremity. Careful resection and knowledge of brachial plexus anatomy, which may be distorted by the tumor, are critical to achieving a successful surgical outcome with predictable symptom resolution. Finally, surveillance magnetic resonance imaging may be warranted for atypical lesions.

We present two cases of progressive isolated damage to the lateral branch of the pectoral nerve with marked atrophy of the clavicular portion of the major pectoral muscle. In our patients, the mechanism of isolated lesions of lateral pectoral nerves have been attributed to repetitive external microtraumas and pressure on the nerve trajectory between the chest and shoulder during sports or occupational activities.

Background Brachial Plexus innervates the upper limb. As it is the point of formation of many nerves, variations are common. Knowledge of these is important to anatomists, radiologists, anesthesiologists and surgeons. The presence of anatomical variations of the peripheral nervous system is often used to explain unexpected clinical signs and symptoms. Case Presentation On routine dissection of an embalmed 57 year old male cadaver, variations were found in the formation of divisions and cords of the Brachial Plexus of the right side. Some previously unreported findings observed were; direct branches to the muscles Pectoralis Minor and Latissimus dorsi from C6, innervation of deltoid by C6 and C7 roots and the origin of lateral pectoral nerve from the posterior division of upper trunk. The median nerve was present lateral to axillary artery. The left side brachial plexus was also inspected and found to have normal anatomy. Conclusion The probable cause for such variations and their embryological basis is discussed in the paper. It is also concluded that although these variations may not have affected the functioning of upper limb in this individual, knowledge of such variations is essential in evaluation of unexplained sensory and motor loss after trauma and surgical interventions to the upper limb.

Background The goal of this study was to clarify the anatomical origins of the suprascapular and lateral pectoral nerves from the brachial plexus as an aid to surgical exploration. Methods Both nerves were studied in 100 adult cadaver specimens. Topographic points of origin were described as distance from the bifurcation of the upper trunk or distance from the formation point of the lateral cord, using visual anatomical models. Results The suprascapular nerve originated from (1) the posterior division of the upper trunk distal to the bifurcation of the upper trunk (61 specimens); (2) the point of upper trunk bifurcation (29 cases); (3) the upper trunk proximal to the bifurcation point (six cases); and (4) directly from the C5 root (four cases). The lateral pectoral nerve originated from (1) the anterior division of the upper trunk proximal to the point of lateral cord formation (88 cases); (2) the point of lateral cord formation (five cases); (3) the lateral cord distal to the lateral cord formation point (four cases); and (4) the anterior division of the middle trunk (three cases). Eighty-two cases had origins from both the anterior upper trunk and the anterior middle trunk. Conclusions The suprascapular nerve most frequently originates from the posterior division of the upper trunk, and the lateral pectoral nerve from the anterior divisions of the upper and middle trunks. This information can be used to guide the surgeon in identifying the key landmarks of the supraclavicular brachial plexus at surgical exploration.