[Rare Compression Syndrome of the Median Nerve due to a Supracondylar Humeral Process and a Ligament of Struthers]. / Seltenes Kompressionssyndrom des N. medianus durch den Processus supracondylaris und das Struthers-Ligament.

INTRODUCTION: A supracondylar process is a bony spur on the distal anteromedial surface of the humerus, and it is considered an anatomical variant with a prevalence of 0.4-2.7% according to anatomical studies. In almost all cases, it is associated with a fibrous, sometimes ossified ligament, which extends from the supracondylar process to the medial epicondyle. This ligament is known in the literature as the ligament of Struthers, named after the Scottish anatomist who first described it in detail in 1854. In rare cases, the supracondylar process can be a clinically relevant finding as a cause of nerve compression syndrome. The median and ulnar nerve can be trapped by the ring-shaped structure formed by the ligament of Struthers and the supracondylar process. CASE REPORT: A 59-year-old patient with symptoms of a cubital tunnel syndrome and additional ipsilateral sensory deficits in his thumb was referred to our clinic. Electroneurography showed no signs of an additional carpal tunnel syndrome. Preoperative x-ray and CT scans of the upper arm revealed a supracondylar process, which led us to suspect an associated entrapment of the median nerve. An MRI scan of the upper arm showed a ligament of Struthers and signs of a related median nerve compression as we initially assumed. We performed a surgical decompression of the median nerve in the distal upper arm and of the ulnar nerve in the cubital tunnel. Intraoperatively, there was evidence of compression of the median nerve due to the supracondylar process and the ligament of Struthers. The latter was cleaved and then resected along with the supracondylar process. Three months after surgery, the patient had no motor or sensory deficits. SUMMARY: The ring-shaped structure formed by the supracondylar process and ligament of Struthers represents a rare cause of compression syndrome of the median and ulnar nerve. Its incidence remains unknown so far. This anatomical variant should be considered a differential diagnosis in case of possibly related nerve entrapment symptoms after ruling out other, more frequent nerve compression causes. Moreover, the supracondylar process should be completely resected including the periosteum during surgery to minimise the risk of recurrence.

Surgical anatomy of the radial nerve in the anterior compartment of the arm: relationship with the triceps aponeurosis.

PURPOSE: Injury to the radial nerve is not an uncommon phenomenon in fracture displacement of distal humerus and its operative management as the nerve is immobile and superficial at its point of entry into the anterior compartment and in close proximity to humerus. Such injuries can be reduced by defining a 'safe area' for the radial nerve in relation to the triceps aponeurosis in the distal humerus. METHODS: Radial nerve was dissected in 40 arms and distance of the nerve from triceps aponeurosis was measured at five sites; first one at the level of proximal or medial apex of aponeurosis, followed by four sites along its lateral border. These distances were analyzed to identify its location and to define a 'safe area' in relation to the triceps aponeurosis in the distal humerus. RESULTS: In majority of cases (67.50%), the point of entry of radial nerve into anterior compartment was at the level of proximal or medial apex at a mean distance of 2.11 ± 0.31 cm. The mean distance of radial nerve from the lateral border of triceps aponeurosis was 1.98 ± 0.60 cm with a range of 1.00-2.50 cm. The closest distance between the nerve and the aponeurosis was found to be 1.00 cm at the level of distal or lateral apex. CONCLUSION: The relationship between radial nerve and triceps aponeurosis is constant and easily reproducible. It is suggested that the rectangular zone immediately adjoining the lateral border of aponeurosis (< 1.00 cm) can be considered "safe" for soft tissue dissection while surgically approaching distal humeral fractures.

Establishing Safe Zones to Avoid Nerve Injury in the Approach to the Humerus in Pediatric Patients: A Magnetic Resonance Imaging Study.

BACKGROUND: The surgical anatomy of upper-extremity peripheral nerves in adults has been well described as "safe zones" or specific distances from osseous landmarks. In pediatrics, relationships between nerves and osseous landmarks remain ambiguous. The goal of our study was to develop a model to accurately predict the location of the radial and axillary nerves in children to avoid iatrogenic injury when approaching the humerus in this population. METHODS: We conducted a retrospective review of 116 magnetic resonance imaging (MRI) scans of entire humeri of skeletally immature patients; 53 of these studies met our inclusion criteria. Two independent observers reviewed all scans. Arm length was measured as the distance between the lateral aspect of the acromion and the lateral epicondyle. We then calculated the distances (defined as the percentage of arm length) between the radial nerve and distal osseous landmarks (the medial epicondyle, transepicondylar line, and lateral epicondyle) as well between the axillary nerve and the most lateral aspect of the acromion. RESULTS: The axillary nerve was identified at a distance equaling 18.6% (95% confidence interval [CI], ±0.62%) of arm length inferior to the lateral edge of the acromion. The radial nerve crossed (1) the medial cortex of the posterior part of the humerus at a distance equaling 63.19% (95% CI: ±0.942%) of arm length proximal to the medial epicondyle, (2) the middle of the posterior part of the humerus at a distance equaling 53.9% (95% CI: ±1.08%) of arm length proximal to the transepicondylar line, (3) the lateral cortex of the posterior part of the humerus at a distance equaling 45% (95% CI: ±0.99%) of arm length proximal to the lateral epicondyle, and (4) from the posterior to the anterior compartment at a distance equaling 35.3% (95% CI: ±0.92%) of arm length proximal to the lateral epicondyle. A strong linear relationship between these distances and arm length was observed, with an intraclass correlation coefficient of >0.9 across all measurements. CONCLUSIONS: The positions of the radial and axillary nerves maintain linear relationships with arm lengths in growing children. The locations of these nerves in relation to palpable osseous landmarks are predictable. CLINICAL RELEVANCE: Knowing the locations of upper-extremity peripheral nerves as a proportion of arm length in skeletally immature patients may help to avoid iatrogenic injuries during surgical approaches to the humerus.

The safety and feasibility of minimal invasive plate osteosynthesis (MIPO) of the posterior aspect of the humerus: A cadaveric study.

The aim of this study was to determine the feasibility of applying MIPO of the humerus via the posterior approach and to observe the tension of the radial nerve in different elbow positions. Two separate incisions were made on the posterior aspect of the humerus in ten fresh cadavers (20 humeri). The radial nerve was identified at the proximal incision and the distances through which the nerve could be elevated from the bone with the elbow in flexion and extension were measured. A 10-hole extra-articular distal humeral locking compression plate was inserted and fixed through the submuscular tunnel. The tunnel was then explored to identify any entrapment of the radial nerve and to observe the anatomical relationship of the radial nerve to the plate and bone. There was no entrapment of the radial nerve or its branches. The distances through which the radial nerve could be elevated were greater with the elbow in extension than in flexion (P < 0.01). The radial nerve crossed the medial and lateral borders of the posterior surface of the humerus at 80.1-132 mm (average 104.7 mm) and 116.6-175.5 mm (average 142.7 mm) of its total length, respectively. The axillary nerve was located at 38.7-61.7 mm (average 47.9 mm) of total humeral length. MIPO of the humerus using the posterior approach is an alternative option for treating distal humeral shaft fracture. The risk of radial nerve injury can be minimized by careful dissection in the proximal incision. Clin. Anat. 32:176-182, 2019. © 2018 Wiley Periodicals, Inc.

Radial nerve palsy in humeral shaft fractures with internal fixation: analysis of management and outcome.

INTRODUCTION: The incidence of radial nerve injury after humeral shaft fractures is on average 11.8% (Shao et al., J Bone Jt Surg Br 87(12):1647-1652, 2005) representing the most common peripheral nerve injury associated with long bone fractures (Korompilias et al., Injury, 2013). The purpose of this study was to analyze our current policy and long-term outcome, regarding surgically treated humeral shaft fractures in combination with radial nerve palsy. MATERIALS AND METHODS: We retrospectively analyzed the data of patients with surgically treated humeral shaft fractures from 01/01/2003 to 28/02/2013. The analysis included fracture type, soft tissue injury regarding closed and open fractures, type of fixation, management, and outcome of radial nerve palsy. RESULTS: A total of 151 humeral shaft fractures were fixed in our hospital. In 20 (13%) cases, primary radial palsy was observed. Primary nerve exploration was performed in nine cases. Out of the 13 patients with follow-up, 10 showed a complete, 2 a partial, and 1 a minimal nerve recovery. Two of them underwent a revision procedure. Secondary radial nerve palsy occurred in 9 (6%) patients postoperatively. In five patients, the radial nerve was not exposed during the initial surgery and, therefore, underwent revision with nerve exploration. In all 5, a potential cause for the palsy was found and corrected as far as possible with full recovery in 3 and minimal recovery in one patient. In four patients with exposure of the nerve during the initial surgery, no revision was performed. All of these 4 showed a full recovery. CONCLUSION: Our study showed an overall rate of 19% radial nerve palsy in surgically treated humeral shaft fractures. Most of the primary palsies (13%) recovered spontaneously, and therefore, nerve exploration was only exceptionally needed. The incidence of secondary palsy after surgery (6%) was high and mainly seen after plate fixation. In these cases, we recommend early nerve exploration, to detect and treat potential curable neural lesions.

Radial nerve location at the posterior aspect of the humerus: an anatomic study of 100 specimens.

PURPOSE: Radial neuropathy represents a devastating complication in a posterior approach to the distal humerus. This study aimed to propose "safe zones" regarding the radial nerve (RN) location at the posterior aspect of the humerus to minimize the risk of iatrogenic injury. METHODS: In 100 embalmed specimens, the distances of the proximal edge of the olecranon fossa (OF) to the radial nerve at the medial edge (R1), at the center (R2) and at the lateral edge (R3) of the posterior aspect of humeral shaft were measured. Humeral length (HL) and transcondylar width (TW) were evaluated and correlated to R1, R2 and R3. RESULTS: R1 was 15.0 (±2.1; 10.6-19.5) cm, R2 averaged 12.7 (±1.6; 8.9-15.7) cm, R3 was 10.6 (±1.3; 7.6-13.7) cm. HL was 30.8 (±1.9) cm. TW averaged 6.3 (±0.6) cm. TW and HL correlate with R1, R2, R3 (r = 0.451-0.565 [95% CI 0.279-0.685]). The mean ratio was 2.3 (±0.18) for HL/R1, 2.6 (±0.23) for HL/R2 and 3.1 (±0.31) for HL/R3. The ratio averaged 2.2 (±0.20) for R1/TW, 1.9 (±0.18) for R2/TW and 1.6 (±0.15) for R3/TW. CONCLUSIONS: We present the OF as an osseous landmark to reduce the risk of iatrogenic radial neuropathy. HL and TW can be reliably used to estimate the RN location. The consistent "safe zones" of the RN in relation to the OF are 10.5 cm at the medial edge, 9 cm at the center and 7.5 cm at the lateral edge of the posterior aspect of the humeral shaft.

[Medial transposition of the radial nerve in steel plate internal fixation of lower segment fracture of humerus].

OBJECTIVE: To investigate the method of medial transposition of the radial nerve in plate fixation of lower segment fracture of humerus. METHODS: From January 2010 to December 2013,31 patients with medial transposition of the radial nerve in plate fixation of lower segment fracture of humerus, including 18 males and 13 females ranging in age from 26 to 58 years old with a mean of 37 years old. The time between injury and operation was 1 to 8 days with an average of 4.5 days. According to AO classification, 7 fractures were type A1, 3 fractures were type A2, 6 fractures were type A3, 2 fractures were type B1, 4 fractures were type B2, 2 fractures were type B3, 4 fractures were type C, 3 fractures were type C2. No patients had any signs of radial nerve injury. The results were evaluated with DASH (disability of arm-shoulder-hand) Questionnaire by the American Academy of Orthopedic Surgeons (AAOS) which 0 indicated normal upper extremity function, and 1 to 100 indicated varying degrees of damage to the function of the upper extremties. RESULTS: There was no neurologic complication or postoperative wound infection in this series. The followed-up period ranged form 8 to 15 months (means 11 months) postoperatively. The clinical outcomes were evaluated with DASH Questionnaire, the score before operation was 76.2±11.8, the final follow-up score was 8.2±7.4, the final follow-up score was significant higher than before operation (P<0.01). The function of the upper extremities recovered satisfactorily. CONSLUSION: The method of medial transposition of the radial nerve in plate fixation of lower segment fracture of humerus can avoid iatrogenic radial nerve injury effectively.

Supracondylar process syndrome: case report and literature review.

The supracondylar process is a congenital bone projection on the distal anteromedial humerus often associated with a ligament of Struthers, a fibrous connection between the process and medial epicondyle. It is largely asymptomatic and only on rare occasions presents with neurovascular compression resulting in a supracondylar process syndrome. This case report describes a 28-year-old woman with supracondylar process syndrome, and our management. The topic is further explored with a literature review of 43 reported cases. Analysis of the case reports indicates that isolated median nerve injuries are the most common. Other presentations such as fractures, vascular compromise, and ulnar nerve involvement are less frequent.

Avoiding iatrogenic radial nerve injury during humeral fracture surgery: a modified approach to the distal humerus.

OBJECTIVE: Our aim was to assess the results of posterior retraction technique to prevent iatrogenic radial nerve injury during humeral fracture surgery. METHODS: Seventy-two patients who underwent surgery for a distal humerus fracture between 1996 and 2002 were reviewed. These 72 patients comprised Group 1. Following a cadaveric study on the vascularization of the radial nerve, a modified surgical approach was undertaken starting in 2002. Sixty-one patients who underwent this new surgical approach were included in Group 2. The rates of radial nerve deficit of the groups were compared using the Pearson chi-square test. RESULTS: In Group 1, 19 iatrogenic nerve deficits occurred. After defining the blood circulation of the nerve, the lateral approach was modified. The anterolateral side of the nerve was released and the nerve was left attached to the triceps muscle. In Group 2, one patient developed postoperative transient nerve deficit. CONCLUSION: The radial nerve is supplied by the branches of the deep brachial artery in close relation with the triceps muscle. Anterior dissection and posterior retraction of the radial nerve during lateral approach may preserve its blood supply and reduces the risk of iatrogenic injury.

Incidence of humeral head of biceps brachii muscle: anatomical insight / Incidencia de la cabeza humeral del músculo bíceps braquial - visión anatómica

Biceps brachii is stated as one of the muscles that shows most frequent anatomical variations. Its most commonly reported anomaly is the presence of an accessory fascicle arising from the humerus which is termed as the humeral head of biceps brachii. Evidence shows a clear racial trend in the incidence of the humeral head of biceps brachii. Therefore, detailed knowledge of this variation in different populations is important for surgical interventions of the arm, nerve compression syndromes and in unexplained pain syndromes in the arm or shoulder region. The goal of this study was to elucidate the incidence and morphological features of this muscle in an adult Sri Lankan population. Upper extremities of the total of one hundred thirty five cadavers were dissected and studied for the presence of accessory heads of the biceps brachii muscle. The proximal and distal attachments of the humeral heads as well as their cranio-caudal, antero-posterior and medio-lateral dimensions were recorded. The incidence of humeral head of biceps brachii was found to be 3.7 percent. In all cases, it was found unilaterally and only in male subjects. The humeral head originated from the antero-medial aspect of the humeral shaft and descended and merged with the other two heads to form a common tendon. The results of the present study further highlight the racial variations in the incidence of humeral head of biceps brachii among Sri Lankans. Knowledge of the occurrence of humeral head of biceps brachii may facilitate preoperative diagnosis as well as the surgical procedures of the upper limb thus avoiding iatrogenic injuries.

El músculo bíceps braquial se conoce como uno de los músculos que muestra las variaciones anatómicas más frecuentes. Su anomalía más común es la presencia de un fascículo accesorio proveniente del húmero, que se denomina cabeza humeral del músculo bíceps braquial. La evidencia muestra una clara tendencia racial en la incidencia de la cabeza humeral del músculo bíceps braquial. El conocimiento acabado de esta variación, en las diferentes poblaciones, es importante para las intervenciones quirúrgicas del brazo, en los síndromes de compresión nerviosa y en los síndromes de dolor inexplicable en la región del brazo o del hombro. El objetivo de este estudio fue determinar la incidencia y las características morfológicas de este músculo en una población adulta de Sri Lanka. Fueron estudiados los miembros superiores en 135 cadáveres, disecados para evaluar la presencia de las cabezas del músculo bíceps braquial accesorio. Fueron registrados el origen e inserción de la cabeza humeral del músculo bíceps braquial, así como su dimensión cráneo-caudal, anteroposterior y mediolateral. La incidencia de la cabeza humeral del músculo bíceps braquial se encontró en el 3,7 por ciento de los miembros estudiados. En todos los casos, su presencia era unilateral y sólo presente en hombres. La cabeza humeral se originó en la región antero-medial de la diáfisis del húmero, descendió y se fusionó con las otras dos cabezas para formar un tendón común. Los resultados de este estudio resaltan aún más las variaciones raciales en la incidencia de la cabeza humeral del músculo bíceps braquial, entre los habitantes de Sri Lanka. El conocimiento de la presencia de la cabeza humeral del músculo bíceps braquial puede facilitar el diagnóstico preoperatorio, así como los procedimientos quirúrgicos del miembro superior, evitando las lesiones iatrogénicas.

Perioperative analgesia for forequarter amputation in a child: a dual paravertebral approach.

We describe the management of postoperative pain for a 10-year-old girl who underwent forequarter amputation for osteosarcoma of the left humerus. Because the brachial plexus itself was divided and resected during surgery, and the main body part innervated by the nerves from this plexus (the entire upper limb including the scapula and clavicle) was removed, providing analgesia via a brachial plexus block alone would probably not have provided adequate coverage. Because the tissue not resected with this surgery was innervated via the cervical and brachial plexuses and some upper thoracic nerve roots, we elected to combine a perioperative high continuous cervical paravertebral block at the C5 level with a continuous thoracic paravertebral block at the T2 level for postoperative analgesia. Our patient experienced excellent postoperative analgesia and required no narcotics during the immediate postoperative period.

Surgical anatomy of the radial nerve at the elbow.

An anatomical study of the brachial portion of the radial nerve with surgical implications is proposed. Thirty specimens of arm from 20 fresh cadavers (11 male, 9 female) were used to examine the topographical relations of the radial nerve with reference to the following anatomical landmarks: acromion angle, medial and lateral epicondyles, point of division between the lateral and long heads of the triceps brachii, lateral intermuscular septum, site of division of the radial nerve into its superficial and posterior interosseous branches and entry and exit point of the posterior interosseous branch into the supinator muscle. The mean distances between the acromion angle and the medial and lateral levels of crossing the posterior aspect of the humerus were 109 (+/-11) and 157 (+/-11) mm, respectively. The mean length and calibre of the nerve in the groove were 59 (+/-4) and 6 (+/-1) mm, respectively. The division of the lateral and long heads of the triceps was found at a mean distance of 126 (+/-13) mm from the acromion angle. The mean distances between the lateral point of crossing the posterior aspect of the humerus and the medial and lateral epicondyles were 125 (+/-13) and 121 (+/-13) mm, respectively. The mean distance between the lateral point of crossing the posterior aspect of the humerus and the entry point in the lateral intermuscular septum (LIS) was 29 (+/-6) mm. The mean distances between the entry point of the nerve in the LIS and the medial and lateral epicondyles were 133 (+/-14) and 110 (+/-23) mm, respectively. Our study provides reliable and objective data of surgical anatomy of the radial nerve which should be always kept in mind by surgeons approaching to the surgery of the arm, in order to avoid iatrogenic injuries.

Courses of the radial nerve differ between chinese and Caucasians : clinical applications.

We analyzed anatomic distribution of the radial nerve in the upper arms in Chinese-adult embalmed cadavers (120 nerves in 60 cadavers) and compared it with findings reported for Caucasian adults. The acromion, the medial epicondyle, and the lateral epicondyle were used as bony landmarks. We used previously described techniques to quantitatively describe the location of the radial nerve in relation to the surrounding skeleton. Courses of the radial nerve relative to the humeral shaft in Chinese subjects differed from those previously reported for Caucasian subjects. The parameters that differed from Caucasians were: the distances from the acromion to the upper margin (147 +/- 21 mm versus 124 +/- 12 mm), the acromion to the lower margin (195 +/- 36 mm versus 176 +/- 17 mm), and the medial epicondyle to the lower margin (111 +/- 21 mm versus 131 +/- 10 mm). Our study provides information to help identify the radial nerve during surgery and elucidates racial differences in the distribution of the radial nerve between Chinese and Caucasian populations.

Minimally invasive application of the non-contact-bridging (NCB) plate to the proximal humerus: an anatomical study.

OBJECTIVES: To describe a minimal anterolateral acromial approach for minimally invasive (MI) treatment of fractures of the proximal humerus (PH) with the Non-Contact-Bridging (NCB) plate. DESIGN: 1) Cadaver study and 2) clinical case series. SETTING: 1) University Institute of Anatomy and the 2) University Level I trauma center. SPECIMENS/PATIENTS: 1) Ten fresh frozen human humeri and 2) 22 patients with 22 isolated proximal humeral fractures. INTERVENTION: 1) Minimal anterolateral acromial approach with MI application of the NCB-PH plate followed by dissection of the axillary nerve and 2) MI fracture fixation using this approach and technique of plate insertion. MAIN OUTCOME MEASURES: 1) Integrity of the axillary nerve and evaluation of its relationship to the implant, and 2) early postoperative functional results. RESULTS: In the cadaver study, the nerve directly crossed over the percutaneously inserted plate in all the arms. The nerve then divided into two branches anterior to the plate in eight arms and divided into two branches directly over the plate in two arms. One branch of the axillary nerve in one arm was injured. In the clinical case series, no intraoperative complications relating to the approach or the implant occurred. No symptoms of axillary nerve lesion have been detected so far in the early follow-up. CONCLUSIONS: The minimal anterolateral acromial approach is suitable for MI technique to apply the NCB-PH. The relationship of the axillary nerve to the plate is anatomically close. We recommend that strict bone contact be maintained during plate insertion and that screw insertion complies with the guidelines provided for this technique. In a small clinical cases series, the plate and screws were inserted in accordance with these guidelines and no axillary nerve lesions have yet been detected.

An anatomical study of the subcoracoid space

PURPOSE: To evaluate the amplitude of the subcoracoid space under maximum internal and external rotations of the humeral head and measure the distance between the apex of the coracoid process and the following anatomical structures: (a) point of entry of the musculocutaneous nerve and its branches into the coracobrachial muscles and into the short head of the biceps brachii muscle; (b) acromial artery; (c) lesser tubercle of the humerus. METHOD: Thirty shoulders of fresh cadavers, without any kind of shoulder pathology, (9 males and 6 females) were dissected, and the distances (in mm) were measured between the anatomical structures defined above and the apex of the coracoid process. RESULTS: The mean distance between the apex of the coracoid process and the musculocutaneous nerve was 49.2 mm (in all specimens a proximal branch of the nerve was identified 34.2 mm away from the apex of the coracoid process), which was not significantly different between the sexes or body sides; the mean distance between the apex of the coracoid process and the acromial artery was 12.4 mm, which was not significantly different between the sexes or body sides; the mean distance between the apex of the coracoid process and the lesser tubercle of the humerus, with the humeral head under internal rotation, was 10.6 mm in men and 8.6 mm in women, values that were significantly different between the sexes. DISCUSSION: In women, the smaller distance between the apex of the coracoid process and the lesser tubercle of the humerus in the arm internal rotation suggests a higher chance of impingement between those bone structures among the female sex.

OBJETIVO: Avaliar a amplitude do espaço subcoracóide em rotação máxima interna e externa da cabeça do úmero e medir a distância entre o ápice do processo coracóide e as seguintes estruturas anatômicas: (a) ponto de entrada do nervo musculocutâneo e suas ramificações nos músculos coracobraquiais e na cabeça curta do músculo bíceps do braço; (b) artéria acromial; (c) tubérculo menor do úmero. MÉTODO: Foram dissecados trinta ombros de cadáveres novos (nove do sexo masculino e seis do sexo feminino) sem nenhum tipo de patologia de ombro, tendo sido feita a medida (em mm) entre as estruturas anatômicas mencionadas acima e o ápice do processo coracóide. RESULTADOS: A distância média entre o ápice do processo coracóide e o nervo musculocutâneo foi 49,2 mm (em todas as amostras foi identificado um ramo proximal do nervo a 34,2 mm de distância do ápice do processo coracóide) sem significado estatístico em termos de sexo e lado do corpo; a distância média entre o ápice do processo coracóide e a artéria acromial foi 12,4 mm, sem significado estatístico em termos de sexo e lado do corpo; a distância média entre o ápice do processo coracóide e o tubérculo menor do úmero com a cabeça do úmero em rotação interna foi 10,6 mm nos homens e 8,6 mm nas mulheres, valores esses significativos em termos de sexo. DISCUSSÃO: Nas mulheres, a distância menor entre o ápice do processo coracóide e o tubérculo menor do úmero em rotação interna do braço sugere uma probabilidade maior de invasão entre aquelas estruturas ósseas no sexo feminino.

Course of the innervation supply of medial head of triceps muscle and anconeus muscle at the posterior aspect of humerus (anatomical study).

INTRODUCTION: In elbow surgery; posterior side of joint has been described as the front door for accessing the elbow pathologies. Triceps splitting, triceps reflection, posterolateral Kocher, posteromedial Bryan-Morrey, modified MacAusland transolecranon approaches are the well known posterior surgical approaches. In the English literature, release and transposition of ulnar nerve on the medial side was fully described in posterior approaches. We believe that there was a need to identify the structures at the lateral aspect of the elbow while an iatrogenic injury may inversely effect an excellent radiological result. Therefore, we exposed the detailed innervation supply to the anconeus muscle and medial head of triceps muscle and tried to show possible denervation sites of these two structures during posterior approaches. MATERIALS AND METHODS: This study was performed on 14 elbows in formalin-preserved 7 cadavers. We exposed the course of the innervation supply to the medial head of triceps muscle and anconeus muscle and tried to show possible denervation sites of these two structures during posterior approaches. The branching pattern of radial nerve innervating anconeus muscle and its deriving level from radial nerve was identified. Distance from a vertical line which is passing through lateral epicondyle to branching point was measured. RESULTS: The mean distance of the branching point of the nerve to medial head of triceps muscle and anconeus was 168.3 mm (range 130.36-185.4). The nerve to anconeus muscle ran along the posterior aspect of the humerus from the horizontal line passing through lateral epicondyle at a distance of 142.20 mm (range 153.72-136.41) medial to olecranon and at a distance of 47.45 mm (range 77.13-30.14) lateral to olecranon. CONCLUSION: Although splitting the fibers of triceps proximaly increases the exposure of the posterior humerus, innervation of the lateral portion of the medial head of triceps muscle and anconeus muscle may be jeoparadized. Therefore, surgeons who have interest in elbow surgery; (1) should revise the course of the nerve to medial head of triceps and anconeus muscle, (2) be aware of possible iatrogenic injury of the extensor muscles of the elbow via transtricipital approaches, (3) try to choose a more conservative posterior surgical approach.

Superficial surgical landmarks for identifying the posterior interosseous nerve.

OBJECT: There is a paucity of information in the neurosurgical literature regarding the surgical anatomy surrounding the posterior interosseous nerve (PIN). The goal of the current study was to provide easily recognizable superficial bone landmarks for identification of the PIN. METHODS: Thirty-four cadaveric upper extremities obtained from adults were subjected to dissection of the PINs, and measurements were made between this nerve and surrounding superficial bone landmarks. In all specimens the main radial trunk was found to branch into its superficial branch and PIN at the level of the lateral epicondyle of the humerus. Proximally, the PIN was best identified following dissection between the brachioradialis and extensor carpi radialis longus and brevis muscles. At its exit site from the supinator muscle, the PIN was best identified after retraction between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. This site was a mean distance of 6 cm distal to the lateral epicondyle of the humerus. No compression of the PIN by the tendon of origin of the extensor carpi radialis brevis muscle was seen. One specimen was found to have a proximally split PIN that provided a previously undefined articular branch to the elbow joint. The mean diameter of the PIN proximal to the supinator muscle was 4.5 mm. The leash of Henry crossed the PIN in all but one specimen and was found at a mean distance of 5 cm inferior to the lateral epicondyle. The PIN exited the distal edge of the supinator muscle at a mean distance of 12 cm distal to the lateral epicondyle of the humerus. Here the mean diameter of the PIN was 4 mm. The exit site from the distal edge of the supinator was found to be at a mean distance of 18 cm proximal to the styloid process of the ulna. This exit site for the PIN was best identified following dissection between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. The distal articular branch of the PIN was found to have a mean length of 13 cm and the proximal portion of this terminal segment was located at a mean distance of 7.5 cm proximal to the Lister tubercle. CONCLUSIONS: The addition of more anatomical landmarks can help the neurosurgeon to be more precise in identifying the PIN and in avoiding complications during surgery in this region.

The innervation of the medial humeral epicondyle: implications for medial epicondylar pain.

The purpose of this study was identification of the innervation of the medial humeral epicondyle which has not been described before. In 20 patients, the medial intermuscular septum was evaluated histopathologically: the nerve was identified in 15 specimens without S-100 staining, and in the remaining 5 with S-100 staining. In six fresh cadavers, bilateral dissections identified the source of this nerve as the radial nerve in the axilla, coursing adjacent to the ulnar nerve in the upper arm, then moving laterally to be superficial to, or within, the medial intermuscular septum, until the nerve terminated in the periosteum of the medial humeral epicondyle, at the origin of the flexor-pronator muscle mass. In one specimen, a branch from the ulnar nerve in the axilla contributed to this nerve to the medial humeral epicondyle.

Helical plating of the proximal humerus.

The ideal treatment for fractures of the proximal humerus has not been definitively agreed upon. Several recent reports have described a technique of helical plating for proximal humeral fractures, in which the proximal plate is placed laterally on the greater tuberosity, and spirals 90 degrees distally to lie on the anterior surface of the humeral shaft. The purpose of this study was to evaluate the feasibility of helical plating using a less invasive surgical approach and placing screws percutaneously in the distal plate. Dissection of 10 cadaveric upper extremity specimens was performed, using an extended anterolateral acromial approach followed by percutaneous helical plating. With the plate secured, the neurovascular structures which crossed the anterior humerus superficial to the plate were exposed and identified. Only the musculocutaneous nerve crossed anterior to the plate and was at risk for percutaneous screw placement. The nerve location was found in a consistent location among the specimens. The danger zone for the nerve location was found to be at an average of 13.5 cm from the greater tuberosity (99% CI: 12.2-14.8 cm). Though clinical experience is necessary to validate this plating technique, it appears that avoiding this danger zone in which the musculocutaneous nerve crosses will allow safe percutaneous screw placement and permit minimally invasive plating of these fractures.