Extensile approach to the anterolateral surface of the humerus and the radial nerve

Spatial Anatomy of the Radial Nerve in the Extended Deltopectoral Approach

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ²(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

Current advances and novel research on minimal invasive techniques for musculoskeletal disorders

The present review summarized the current advances and novel research on minimal invasive techniques for musculoskeletal disorders. Different invasive approaches were proposed in the physical therapy field for the management of musculoskeletal disorders, such as ultrasound-guided percutaneous needle electrolysis, dry needling, acupuncture and other invasive therapy techniques, discussing about their worldwide status, safety and interventional ultrasound imaging. Indeed, dry needling may be one of the most useful and studies invasive physical therapy applications in musculoskeletal disorders of different body regions, such as back, upper limb, shoulder, arm, hand, pelvis, lower limb, neck, head, or temporomandibular joint, and multiple soreness location disorders, such as fibromyalgia. In addition, the assessment and treatment by acupuncture or electro-acupuncture was considered and detailed for different conditions such as plantar fasciitis, osteoarthritis, spasticity, myofascial pain syndrome, osteoporosis and rheumatoid arthritis. As an increasing technique in physical therapy, the use of ultrasound-guided percutaneous needle electrolysis was discussed in injuries of the musculoskeletal system and entrapment neuropathies. Also, ultrasound-guided percutaneous neuromodulation was established as a rising technique combined with ultrasound evaluation of the peripheral nerve system with different clinical applications which need further studies to detail their effectiveness in different musculoskeletal conditions. Thus, invasive physical therapy may be considered as a promising approach with different novel applications in several musculoskeletal disorders and a rising use in the physiotherapy field.

Fixation of olecranon osteotomy only with 6'5 mm partially trheaded cancellous screw is a safe an effective method used in surgical management of distal humerus fractures

PURPOSE

The objective of this study is to demonstrate the safety and efficacy of the osteosynthesis with a 6.5 mm screw and washer of a Chevron shape olecranon osteotomy performed for the surgical approach of supraintercondylar fractures of the distal humerus, achieving union and complication rates better or similar to other published case series.

METHODS

From 2009 to 2019, 26 patients underwent fixation of an olecranon osteotomy for the treatment of a supraintercondylar fracture of the distal humerus with partially threaded cancellous cannulated screws of 6.5 mm diameter with a washer. The patients were followed for at least 1 year, taking radiographs the day after the surgery, at 3, 6 and 12 months. Complications have been collected: infection, loss of reduction, non-union, delay of union, discomfort of the osteosynthesis hardware. The diameter of the ulna medullary canal diaphysis was also measured in all patients.

RESULTS

Consolidation of the osteotomy was 100% at 12 months. The average time of radiological consolidation was 112 ± 12 days. The average size of the ulna medullary canal diaphysis was 6'06 ± 0'16 mm on anteroposterior radiographs and 5'65 ± 0'14 mm on lateral radiographs. The mean screw length was 102'31 mm ± 3'89. We found 1 acute infection, 2 osteotomies delays of union (one of these cases was the acute infection case), one early osteosynthesis failure and 1 wound dehiscence.

CONCLUSIONS

Olecranon ostetomy fixation with a 6'5 mm cancelous partial threaded screw and washer is safe and effective with a high consolidation rate and excellent results and with complication rates similar to or lower than other fixation methods published. Long enough screws must be used to get a good cortical grip with enough stability.

LEVEL OF EVIDENCE

Level IV, Case series, retrospective review.

A Preoperative Planning Tool: Aggregate Anterior Approach to the Humerus With Quantitative Comparisons

Extensile approaches to the humerus are often needed when treating complex proximal or distal fractures that have extension into the humeral shaft or in those fractures that occur around implants. The 2 most commonly used approaches for more complex fractures include the modified lateral paratricipital approach and the deltopectoral approach with distal anterior extension. Although the former is well described and quantified, the latter is often associated with variable nomenclature with technical descriptions that can be confusing. Furthermore, a method to expose the entire humerus through an anterior extensile approach has not been described. Here, we illustrate and quantify a technique for connecting anterior humeral approaches in a stepwise fashion to form an aggregate anterior approach (AAA). We also describe a method for further distal extension to expose 100% of the length of the humerus and compare this approach with both the AAA and the lateral paratricipital in terms of access to critical bony landmarks, as well as the length and area of bone exposed.

Supine Extensile Approach to the Anterolateral Humerus

The radial nerve is at risk of injury during surgical approaches to the humeral shaft. Previous authors have described an anterolateral approach to the humerus limited by the radial nerve, requiring that distal dissection be carried anterior into a neurovascularly crowded interval. A novel extensile approach is described using a neuromuscular bridge to protect the radial nerve, thus enabling safe distal extension of the anterolateral humerus approach. The authors present a case series of 7 patients who required an extensile humeral exposure. To date, there have been no complications, including loss of reduction, malunion, nonunion, or nerve palsy.

The tricipital aponeurosis--a reliable soft tissue landmark for humeral plating

This study aims to identify the relationship of the radial nerve as it descends across the humerus with reference to a reliable soft tissue landmark, the tricipital aponeurosis. Following cadaveric dissection of 10 adult humerii, the radial nerve was located as it crossed the lateral midsagittal point of the humeral diaphysis. A horizontal line was then subtended medially from this point to another line subtended vertically from the lateral border of the tricipital aponeurosis. The vertical distance from this intersection to the lateral apex of the aponeurosis was recorded in three positions (full flexion, 90° of flexion and full extension). The location of the radial nerve on the posterior aspect of the humeral diaphysis to the medial apex of the tricipital aponeurosis was also noted. In 90° of flexion the radial nerve at the lateral midsagittal point of the humerus was 0.9 mm proximal to the lateral apex of the tricipital aponeurosis. Flexion and extension of the elbow changed the interval to 16.3 mm (nerve proximal) in full flexion and 7.1 mm in full extension (nerve distal). On the posterior aspect of the humerus the radial nerve was 21.8 mm proximal to the medial aspect of the tricipital aponeurosis. The aponeurosis provides a reference point from which the nerve can be easily located on the lateral aspect of the humerus intraoperatively in a range of positions, whilst the medial apex provides a guide to the location of the nerve on the posterior aspect of the arm.

Determining the efficacy of screw and washer fixation as a method for securing olecranon osteotomies used in the surgical management of intraarticular distal humerus fractures

OBJECTIVES

The purpose of this study was to critically evaluate the efficacy of single screw and washer fixation in comparison with other methods for securing olecranon osteotomies. The hypothesis is that screw and washer fixation is a safe and effective means of olecranon osteotomy fixation with fusion and complication rates similar to other methods of fixation.

DESIGN

Retrospective review.

SETTING

Two Level I Urban Trauma Centers.

PATIENTS/PARTICIPANTS

Patients were treated within the last 20 years and received 1 of 4 types of fixation (screw and washer alone, screw and washer augmented with tension band, tension band alone, or plate and screws) after osteotomy.

INTERVENTION

Open reduction and internal fixation of OTA/AO 13B/C distal humerus fractures with an olecranon osteotomy.

MAIN OUTCOME MEASUREMENTS

The primary outcome measure was the presence of osteotomy union. Secondary outcome measures were olecranon nonunion, loss of articular reduction, and removal of hardware. Logistic regression was used to determine the associations between method of osteotomy fixation and removal of hardware or nonunion rates. Comorbidities were stratified using the Charlson comorbidity index.

RESULTS

One hundred sixty patients met the inclusion criteria. Thirty-nine patients underwent screw fixation alone, 47 had tension band fixation, 16 had plate fixation, and 58 had tension band and screw fixation. Screw fixation demonstrated equal or better rates of union, maintenance of reduction, absence of infection, and implant removal compared with alternative fixation techniques. Higher Charlson scores were associated with higher rates of nonunion.

CONCLUSIONS

Screw and washer fixation is a safe and effective means of securing an olecranon osteotomy. Charlson comorbidity score is one factor that may influence the development of nonunion after osteotomy.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Safe zone for superolateral entry pin into the distal humerus in children: an MRI analysis

BACKGROUND

The radial nerve is at risk for iatrogenic injury during placement of pins, screws, or wires around the distal humerus. Unlike adults, detailed anatomic information about the relationship of the nerve to the distal humerus is lacking in children.

QUESTION/PURPOSES

This study evaluates the relationship of the radial nerve to the distal humerus in a pediatric population on conventional MRI and proposes an anatomic safe zone using easily identifiable bony landmarks on an AP elbow radiograph.

METHODS

To determine the course of the radial nerve at the lateral distal humerus, we reviewed 23 elbow radiographs and MRIs of 22 children (mean age, 9 ± 4 years; range, 3-12 years) obtained as part of their workup for various elbow conditions. We described a technique using distance ratios calculated as a percentage of the patient's own transepicondylar distance, defined as the distance measured between the apices of the medial and lateral epicondyles, on the AP elbow radiograph and the midcoronal MR image. The cross-reference tool on a Picture Archiving and Communication System was then used to identify axial MR image at the level where the transepicondylar distance was measured. On this axial image, a line was drawn connecting the medial and lateral epicondyles (the transepicondylar axis) and its midpoint was determined. The radial nerve angle was measured by a line from the radial nerve to the midpoint of the transepicondylar axis and a line along the lateral half of the transepicondylar axis. On this axial slice, the closest distance from the nerve to the underlying cortex of the distal humerus was measured. To further localize the nerve along the distal humerus, predetermined percentages of the transepicondylar distance were projected proximally from the level of the transepicondylar axis along the longitudinal axis of the humerus on the midcoronal MR image. At these designated heights, the corresponding axial MR image was identified using the cross-reference tool and the nerve was mapped in a similar fashion. We then proposed a simpler method using a best-fit line drawn along the lateral supracondylar ridge on the AP radiograph to define the safe zone for lateral pin entry.

RESULTS

On axial MR images, the radial nerve was located in the anterolateral quadrant with a mean radial nerve angle of 54° (range, 35°-87) at 0% transepicondylar distance (23 MRIs), 41° (range, 24°-63°) at 50% transepicondylar distance (23 MRIs), and ≥ 10° at 75% transepicondylar distance (on the 13 MRIs that extended this far cephalad). The mean closest distance between the radial nerve and the underlying humeral cortex was 10 mm (range, 3-26 mm) at 0% transepicondylar distance and 7 mm (3-16 mm) at 50% transepicondylar distance. On the AP elbow radiograph, the height of the lateral supracondylar ridge, determined by a best-fit line drawn along the lateral cortex of the ridge, diverged from the most proximal extent of the ridge at a point located at 60% transepicondylar distance (range, 51%-76%). At the corresponding location on the axial MR image, the nerve was located anterolaterally with a mean radial nerve angle of 39° (range, 15°-61°) and a mean distance of 6 mm (range, 2-10 mm) from the underlying humerus.

CONCLUSIONS

Our data suggest that percutaneous direct lateral entry Kirschner wires and half-pins can be safely inserted in the distal humerus in children along the transepicondylar axis, either at or slightly posterior to the lateral supracondylar ridge, when placed caudal to the point located where the lateral supracondylar ridge line diverges from the proximal extent of the supracondylar ridge on AP elbow radiograph.

The anterolateral approach to the proximal humerus for nonunions and delayed unions

Nonunions of proximal humerus fractures can be disabling as a result of pain, deformity and instability, and are often found in geriatric patients with poor bone quality. There are relatively few studies examining the treatment of nonunions of the proximal third of the humerus and the ideal treatment and surgical approach remains unclear. This case series reports the successful use of the anterolateral acromial approach for treatment of the symptomatic proximal third humerus nonunions in a geriatric group of patients with clear challenges as a result of patient comorbidities and bone quality.

The extended deltoid-splitting approach to the proximal humerus: variations and extensions

Fractures and nonunions of the proximal humerus are increasingly treated by open reduction and internal fixation. The extended deltopectoral approach remains the most widely used for this purpose. However, it provides only limited exposure of the lateral and posterior aspects of the proximal humerus. We have previously described the alternative extended deltoid-splitting approach. In this paper we outline variations and extensions of this technique that we have developed in the management of further patients with these fractures.

A lateral approach to the distal humerus following identification of the cutaneous branches of the radial nerve

We describe a lateral approach to the distal humerus based on initial location of the superficial branches of the radial nerve, the inferior lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm. In 18 upper limbs the superficial branches of the radial nerve were located in the subcutaneous tissue between the triceps and brachioradialis muscles and dissected proximally to their origin from the radial nerve, exposing the shaft of the humerus. The inferior lateral cutaneous nerve of the arm arose from the radial nerve at the lower part of the spiral groove, at a mean of 14.2 cm proximal to the lateral epicondyle. The posterior cutaneous nerve of the forearm arose from the inferior lateral cutaneous nerve at a mean of 6.9 cm (6.0 to 8.1) proximal to the lateral epicondyle and descended vertically along the dorsal aspect of the forearm. The size and constant site of emergence between the triceps and brachioradialis muscles constitute a readily identifiable landmark to explore the radial nerve and expose the humeral shaft.

The distribution of the radial and musculocutaneous nerves in the brachialis muscle

Few have examined the distribution of the radial nerve branch to brachialis, generally believed to be motor, within the muscle. We examined the right brachialis muscles of six dissecting room cadavers and found that four received a supply from the radial nerve. The radial nerve branch(es) supplied the inferolateral region of the muscle and was overlapped proximodistally and mediolaterally by the intramuscular branches of the musculocutaneous nerve, which lay on a more superficial plane. The results have implications for the anterolateral approach to the humerus for orthopedic surgery. Anterior splitting of the muscle will almost certainly damage the most lateral branches of the musculocutaneous nerve.

The combined olecranon osteotomy, lateral paratricipital sparing, deltoid insertion splitting approach for concomitant distal intra-articular and humeral shaft fractures

Fractures of the distal humerus involving the articular surface can be challenging. The complexity of these fracture patterns increases when the distal fracture is associated with a concomitant humeral shaft fracture with significant proximal extension. The combined exposure technique described here allows for consistent and controlled posterior humeral exposure proximally from the traverse of the axillary nerve to the distal trochlear tip. It is especially useful for complex segmental fracture patterns where distal intra-articular involvement is present and a single approach is desired.

Surgical exposures of the humerus

The neurovascular and muscular anatomy about the humerus precludes the use of a truly "safe" fully extensile approach. Working around a spiraling radial nerve at the posterior midshaft requires either a transmuscular dissection or a triceps-avoiding paramuscular technique. To gain maximal exposure, the radial nerve must be mobilized at the spiral groove. For exposure of only the proximal humeral shaft, many surgeons prefer the anterolateral approach because it uses the internervous plane between the axillary and deltoid nerves proximally and the radial and musculocutaneous nerves distally. Proximally, the deltopectoral approach to the shoulder continues to be the most widely used. However, the lateral deltoid-splitting approach is a viable, less invasive approach for both rotator cuff repair and fixation of valgus-impacted proximal humeral fractures. Distally, intra-articular exposure is dependent on triceps mobilization, either by olecranon osteotomy or triceps release; this exposure can be coupled with either a triceps-splitting or a paratricipital approach for proximal extension.

A cadaveric study on the anatomy of the deltoid insertion and its relationship to the deltopectoral approach to the proximal humerus

Elevation of the deltoid insertion (DI) has been recommended, but little is known about its anatomy or importance for deltoid function. The purpose of this study is to determine the dimensions of the DI with specific reference to the deltopectoral approach. The deltoid was exposed and detached at its origin in 36 cadaveric shoulders. The morphology of the DI was documented, and its relationship with the pectoralis major insertion and the axillary and radial nerves was recorded. The anterior, middle, and posterior deltoid muscle fibers entered into the DI in a V-shaped tendinous confluence with a broad posterior band and a narrow separate anterior band, which accounted for the anterior one fifth of the DI (0.44 cm). The deltoid insertion was separated from the pectoralis major insertion by as little as 2 mm in 31 of 36 specimens. The distance between the axillary nerve and the DI averaged 5.6 cm anteriorly and 4.5 cm posteriorly. The distance between the radial nerve and posterior deltoid insertion averaged 2.4 cm proximally and 1.6 cm distally. Exposure during the deltopectoral approach is most limited by the close proximity of the deltoid and pectoralis major insertions. Our study would suggest that partial anterior DI release (greater than one fifth) could compromise the anterior deltoid. The axillary and radial nerves are not at significant risk when operating in the region of the anterior DI.

Combined olecranon osteotomy and posterior triceps splitting approach for complex fractures of the distal humerus

Complex fractures involving the intercondylar/supracondylar distal humerus with extension into the mid to proximal humeral shaft are difficult to manage through a single standard surgical approach. We present and review a technique that combines an olecranon osteotomy with a posterior triceps splitting approach to the humerus. This technique was used in two patients who presented with severe intercondylar fractures of the distal humerus and extension proximally to the midshaft of the humerus. The technique allowed extensive distal humerus exposure, including the supracondylar/intercondylar region, and excellent exposure of the humeral shaft proximally to the surgical neck.

One-third, two-thirds: Relationship of the radial nerve to the lateral intermuscular septum in the arm

The radial nerve penetrates the lateral intermuscular septum of the arm before dividing into deep and superficial branches. It may be encountered in both anterior and posterior approaches to the humerus. An ability to accurately predict the point at which the nerve pierces the septum would be valuable during surgery in the arm, and would facilitate planning an approach to exploring the radial nerve after fractures of the distal humeral shaft. It would, in particular, make minimally invasive surgical techniques less dangerous. We dissected 20 cadaver upper limbs to establish whether the radial nerve enters the anterior compartment of the arm at a predictable level. We found that in almost every case the radial nerve entered the anterior compartment at a point within 5 mm of the junction of the distal and middle thirds of a line joining the lateral epicondyle of the humerus to the most lateral point of the acromion process of the scapula. This has not previously been described, and we believe is a useful aide-de-memoir to predicting the level at which the radial nerve penetrates the lateral intermuscular septum.

Upper extremity peripheral nerve anatomy: current concepts and applications

The nerve anatomy of the upper extremity is studied constantly through surgical findings, electrodiagnostic studies, and cadaveric dissections. Although it is recognized that the anatomy is not changing rapidly, knowledge of the anatomic relationships and their significance is increasing. The purpose of the current study is to provide a comprehensive analysis of the nerve anatomy of the upper extremity to include innervation patterns, critical landmarks, and clinical applications, with particular focus on recent contributions in the literature.