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

Management of Pediatric Proximal Humerus Fractures

Proximal humerus fractures have an outstanding potential to remodel due to their proximity to the proximal humeral physis. Fractures in young children can be treated nonoperatively with excellent outcomes. The incidence peaks in adolescent patients and these injuries most commonly occur after a fall or direct trauma. The muscle attachments of the proximal humerus act as deforming forces and anatomic structures such as the periosteum and biceps tendon may act as blocks to reduction. Operative management is uniformly indicated for patients with open fractures, ipsilateral elbow or forearm injury, associated neurovascular injury, or poly-trauma patients. Operative treatment may be further considered in older children with minimal growth remaining and with fractures that are considered significantly displaced by available classification systems. Unfortunately, there are significant challenges in recommending treatment based on displacement and age alone. The purpose of this paper is to review what is known about these injuries and how they can be treated in light of current deficiencies in the literature; this may stimulate further work to refine indications for treatment based upon age and displacement. Key Concepts•The proximal humerus physis is responsible for 80% of the growth of the entire bone, and proximal humerus fractures have tremendous potential to remodel.•Proximal humerus fractures occur most commonly due to a fall or direct trauma but other causes include overuse injury and pathologic lesions.•Treatment indications for pediatric proximal fractures are guided by age of the patient, fracture displacement, and associated injuries; the majority of these injuries may be treated nonoperatively.•Outcomes after operative and nonoperative management of proximal humerus fractures are generally good.

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.].

Transdeltoid Approach to Axillary Nerve Repair: Anatomical Study and Case Series

PURPOSE

In cases of isolated paralysis of the axillary nerve, dissection of the distal stump at the posterior deltoid border can be difficult because of scarring from an injury or previous surgery. To overcome this, we propose dissecting the anterior division of the axillary nerve (ADAN) using a deltoid-splitting approach. We investigated the anatomy of the ADAN as it pertains to the transdeltoid approach and report the clinical application of this approach in 9 patients with isolated axillary nerve injury.

METHODS

The axillary nerve and its branches were dissected in 9 fresh cadaver specimens. In the clinical series, 1 patient with a lesion confined to the ADAN underwent nerve grafting. In the remaining 8 patients, the ADAN was repaired by transferring the triceps lower medial head and anconeus (TLMA) motor branch via a single-incision or double-incision posterior arm approach.

RESULTS

The posterior division of the axillary nerve does not travel around the humerus. It innervated the posterior deltoid and teres minor muscles. At the posterior margin of the humerus, the ADAN ran adjacent to the teres minor tendon. The ADAN's trajectory on the lateral side of the humerus was 65 mm (SD ± 8 mm) from the midpoint of the acromion. One centimeter from the origin, the ADAN offered a prominent branch to the middle deltoid and wound around the humerus anteriorly at the surgical neck just distal to the infraspinatus tendon. A transdeltoid approach was feasible in all our patients. The TLMA was reached without any tension in the ADAN. Middle deltoid strength in 1 patient who had received a graft scored M3, while anterior and middle deltoid strength in the remaining patients who underwent nerve transfers scored M4.

CONCLUSIONS

With axillary nerve lesions, reinnervation of the ADAN is a priority. The transdeltoid approach between the posterior and middle deltoid offers a direct and feasible approach to the ADAN.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Incidence of avascular necrosis following biceps tenodesis during proximal humerus open reduction and internal fixation

Avascular necrosis (AVN) may occur in up to 77% of proximal humeral fractures and can cause fixation failure. Risk factors include fracture position, calcar length and medial hinge integrity. We routinely perform intra-articular biceps tenotomy with tenodesis at the level of pectoralis major to facilitate fragment identification and potentially ameliorate post-operative pain relief. Concern exists that tenotomising the biceps damages the adjacent arcuate artery, potentially increasing the rate of AVN. The purpose of this study was to evaluate whether biceps tenodesis is associated with an increased risk of radiographically evident humeral head AVN. 61 fractures surgically treated over a 52-month period were retrospectively reviewed and radiographically assessed in accordance with Neer’s classification, calcar-length and medial hinge integrity. 40, 20 and 1 were four-, three- and two-part fractures respectively. 37 had a calcar-length less than 8mm and 26 suffered loss of the medial hinge. The median radiographic follow-up was 23 months. There was radiographic evidence of humeral head AVN in only one case, comparing favourably to rates quoted in current literature. In our experience, intra-articular biceps tenotomy with the deltopectoral approach was thus not associated with a significantly increased risk of humeral head AVN, even in complex four-part fractures.

Open Reduction and Long Locking Plate Fixation of Complex Proximal Humeral Metadiaphyseal Fractures

BACKGROUND

A minority of proximal humeral fractures extend into the diaphysis and their optimal treatment remains controversial. We evaluated the outcomes and risk of complications in patients with these injuries, treated by a protocol of open reduction and long locking plate fixation (LPF).

METHODS

Between 2007 and 2014, all locally resident patients with a proximal humeral fracture extending into the diaphysis were referred to a specialist shoulder clinic. Operative treatment using a protocol of open reduction and LPF was offered to medically fit patients. Those with 2-year radiographic follow-up were included in the study, and standardized assessments of clinical and radiographic outcomes were performed during the first 2 years postoperatively. At a mean of 8.8 years (range, 5 to 12 years) after LPF, the functional outcomes and satisfaction of surviving, cognitively intact patients were assessed with a questionnaire study.

RESULTS

One hundred and two patients met the inclusion criteria; the majority were older women who had incurred the injury during a simple fall. Fractures were divided into 2 types depending on the pattern of diaphyseal extension. The pain levels, functional scores, and satisfaction with treatment were satisfactory both at the 2-year follow-up and at the longer-term follow-up at a mean of 8.8 years postsurgery. Complications were predominantly due to postsurgical stiffness (in 7 patients, with 3 undergoing additional surgery) and nonunion or fixation failure (in 7 patients, with 6 undergoing additional surgery).

CONCLUSIONS

Proximal humeral fractures with diaphyseal extension are rare. The results of our study support the use of LPF in medically stable patients in centers with the expertise to perform these procedures.

LEVEL OF EVIDENCE

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

Locking Plates versus Locking Intramedullary Nails Fixation of Proximal Humeral Fractures Involving the Humeral Shaft: A Retrospective Cohort Study

Background

For proximal humeral fractures (PHFs), locking intramedullary nails and locking plates have been widely used. However, few reports have been published on the therapy of complex PHFs accompanying humeral shaft fractures. Therefore, we performed this research to analyze the effectiveness of locking intramedullary nails and locking plates in the management of proximal humeral fractures involving the humeral shaft.

Material/Methods

We retrospectively reviewed 40 cases diagnosed with proximal humeral fractures involving the humeral shaft fixed with either locking intramedullary nails or locking plates with at least of 2 years’ follow-up. Clinical data were obtained from the medical records. Follow-up data included the Constant-Murley score, American Shoulder and Elbow Surgeons score (ASES), visual analog scale score (VAS), and the relative strength of the supraspinatus and deltoid muscles.

Results

In total, 19 locking plate patients and 21 locking intramedullary nail patients were analyzed. The average follow-up period was 35 months in the locking plate group and 34 months in the locking intramedullary nail group. There were obvious differences in the intraoperative blood loss, time of operation, and the length of operative incision between the 2 groups (p<0.05). There were no significant differences between the groups in Constant-Murley score, ASES, VAS, or the relative strength of supraspinatus and deltoid muscles.

Conclusions

For PHFs involving the humeral shaft, both locking plates and locking intramedullary nails can achieve satisfactory functional results in the long-term follow-up assessment. The locking intramedullary nail group was superior with regards to intraoperative blood loss, time of operation, and length of incision.

Complications and Long-Term Outcomes of Open Reduction and Plate Fixation of Proximal Humeral Fractures

BACKGROUND

The optimal treatment of complex proximal humeral fractures in adults remains controversial. We evaluated the risk of complications and the long-term outcomes in patients with a severely displaced fracture or a fracture-dislocation of the proximal part of the humerus treated with open reduction and plate fixation (ORIF).

METHODS

Between 1995 and 2012, 5,897 consecutive patients with a proximal humeral fracture were referred to a specialist shoulder clinic for surgical assessment. Indications for surgery included anterior or posterior fracture-dislocation, substantial tuberosity involvement with >1 cm of displacement in a Neer 3 or 4-part fracture configuration, disengagement of the head from the shaft, or severe varus or valgus deformity of the head. All patients who met the surgical criteria and had been followed for 2 years were included, and standardized clinical and radiographic assessments of outcomes were performed. At a median of 10.8 years (range, 5 to 22 years) after ORIF, all surviving cognitively intact patients completed a patient-reported questionnaire assessing functional outcomes and satisfaction.

RESULTS

Three hundred and sixty-eight patients (6.2%) met the inclusion criteria and had the appropriate follow-up. The study population had a high rate of complex fracture configurations; 77.2% had tuberosity involvement, 54.1% had complete head-shaft disengagement, and 44.0% had a dislocated head. Eighty-seven patients (23.6%) had postoperative stiffness, 25 (6.8%) had fixation failure/nonunion, and 16 (4.3%) had late osteonecrosis/posttraumatic osteoarthritis; these complications were the reason for the majority of the reoperations in the cohort. The survivorship until any reoperation was 74% at 10 years, but when reoperations for stiffness were excluded, the survivorship was 90% during the same time period. The patients' mean levels of pain, function, and satisfaction with treatment were good to excellent.

CONCLUSIONS

Our results support the use of primary ORIF in medically fit patients with a severely displaced fracture or a fracture-dislocation of the proximal part of the humerus in centers where the expertise to carry out such treatment exists.

LEVEL OF EVIDENCE

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

Surgical Approaches to the Proximal Humerus: A Quantitative Comparison of the Deltopectoral Approach and the Anterolateral Acromial Approach

Background:

Debate exists over the optimal approach for addressing fractures of the proximal humerus. The purpose of this study was to objectively quantify the surface area of the humerus exposed using the deltopectoral (DP) and anterolateral acromial (ALA) approaches and to compare visualized and palpable anatomic landmarks.

Methods:

Ten arms on five fresh-frozen torsos underwent the DP and ALA approaches. The arms were positioned to simulate a supine patient and held in a fixed position. Visual and/or palpable access to relevant surgical landmarks and the myotendinous junctions were recorded. The myotendinous junctions were used as a rough approximation of consistent proximal exposure of a clinically retracted tuberosity. Landmarks were grouped into quadrants based on the location. Calibrated digital photographs of each approach were analyzed to calculate the surface area and the length of the exposed bone.

Results:

The DP and ALA approaches exposed 22.9 ± 6.3 cm² and 16.3 ± 6.4 cm², respectively (P = 0.03). The DP and ALA approaches provided equivalent visual and palpable access to all landmarks in the superior and inferior quadrants. The ALA allowed improved visual (80% versus 70%) and palpable (100% versus 70%) access to the myotendinous junction of the infraspinatus in the posterior quadrant. The DP approach allowed better access to anterior quadrant structures, including improved ability to visualize the myotendinous junction of the subscapularis (100% versus zero), the subscapularis insertion (100% versus 80%), and the medial anatomic neck (100% versus 20%). Palpable access to the myotendinous junction of the subscapularis (100% versus 70%) and medial anatomic neck (100% versus 60%) was also improved with the DP.

Conclusions:

In a cadaver model with fixed arm position, the DP provides increased exposure to the proximal humerus and more reliable access to anterior surgical landmarks, whereas the ALA allows improved access to the most posterior aspect of the shoulder.

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.

MIPO of proximal humerus fractures through an anterolateral acromial approach. Is the axillary nerve at risk?

PURPOSE

It is known that shoulder surgery may cause iatrogenic injury to the axillary nerve as a serious complication, but there is little evidence to indicate whether the axillary nerve is at risk of injury during an anterolateral acromial approach for minimally-invasive plate osteosynthesis (MIPO) of proximal humerus fractures. We hypothesised that this surgical method is safe for the axillary nerve and would preserve it from iatrogenic injury.

MATERIALS AND METHODS

We conducted a prospective follow-up cohort study on 49 consecutive patients with proximal humerus fractures who were managed with MIPO through an anterolateral approach. All patients underwent standardised electroneurographic testing, with assessment of amplitudes of evoked compound muscle action potentials (CMAP) and distal motor latencies (DML) of the axillary nerves, pre- and post-operatively. Six weeks after injury, all patients underwent needle electromyographic (EMG) testing of anterior, middle, posterior deltoid, teres minor and paraspinal muscles for detecting abnormal muscle activity as a sign of acute denervation. After six months of physical rehabilitation, patients with axillary nerve injury underwent control electroneurographic testing to check the recovery of neurographic features (CMAP, DML). All nerve measurements were compared to reference values, and between right and left side.

RESULTS

Five patients had a mild-to-moderate traumatic axillary nerve injury before surgery. There were no significant differences between amplitudes of CMAP (p = 0.575) and DML (p = 0.857) pre- and post-surgical procedure.

CONCLUSIONS

These results confirmed safety of this surgical method in the preservation of axillary nerve from iatrogenic injury, but the course of the axillary nerve must be kept in mind.

Axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures through an extended lateral deltoid-split approach: electrophysiological findings

BACKGROUND

Axillary nerve injuries after shoulder surgery are rare. In most studies, the frequency of injury is usually determined using clinical examinations, but results from intraoperative neuromonitoring studies have revealed higher than expected rates. Few studies have investigated this topic. Our aim was to determine the frequency of axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures by using electrophysiological assessments and to provide a review of the relevant literature.

METHODS

This was a retrospective cohort study of 76 consecutive patients who received open reduction and internal fixation of a proximal humeral fracture using a locking plate through a deltoid-splitting approach. We performed a clinical and electrophysiological examination at a minimum follow-up time of 12 months. Functional results were assessed according to the Constant-Murley and Disabilities of the Arm, Shoulder and Hand scores. Electrophysiological examinations comprised electromyography, electroneurography, and motor and somatosensory evoked potentials. The main outcome was the frequency of axillary nerve lesions.

RESULTS

Forty patients were monitored for an average of 28 months. The mean raw Constant-Murley score was 61 points, the age- and gender-adjusted score was 71%, and the mean Disabilities of the Arm, Shoulder and Hand score was 33 points. Neurapraxia occurred in 1 patient, axonotmesis with incomplete reinnervation occurred in 3, and complete reinnervation occurred in 3. The latter group was classified as having a temporary axillary nerve lesion.

CONCLUSIONS

The 10% rate of permanent axillary nerve lesions in our cohort is higher than expected based on the clinical examination. Electrophysiological assessment is therefore more appropriate to detect axillary nerve injuries.

Is the Axillary Nerve at Risk During a Deltoid-Splitting Approach for Proximal Humerus Fractures?

OBJECTIVES

The strain placed across the axillary nerve during the deltoid-splitting approach could correlate with microtrauma and place the patient at risk of a neuropraxia or more permanent injury. The purposes of this study were to evaluate the change in length and strain exhibited by the axillary nerve during the deltoid-splitting approach and to determine the presence of any microscopic structural damage.

METHODS

The axillary nerve was identified through a lateral deltoid-splitting approach in 10 fresh-frozen cadaver specimens. Two suture tags were placed near the lateral margins of the incision. The initial distance between the 2 tags was measured and the distance at each retractor click of a Kölbel retractor until full expansion (6 clicks). The retractor was then released for a 1-minute break at 30, 60, 90, and 120 minutes. The strain at each interval was calculated as change in length divided by the initial distance. The section of nerve in the field of exposure was excised for histologic analysis.

RESULTS

The location of the axillary nerve was 6.32 cm (range, 5.20-7.6 cm) from the anterolateral aspect of the acromion. The mean final increase in length was 8.42 mm (range, 6.43-12.26 mm). The strain increased to a final mean of 51% (range, 28%-99%). Histologic analysis confirmed disruption of the myelin sheaths and axonal retraction.

CONCLUSIONS

This study demonstrated a progressive, irreversible increase in axillary nerve length and strain, resulting in microscopic damage to the neuronal structure during a deltoid-splitting approach. Prolonged soft tissue retraction can place the axillary nerve at substantial risk for injury.

Surgical Exposures of the Shoulder

Surgical repair, reduction, fixation, and reconstruction for glenohumeral trauma, instability, and degenerative joint disease often require an open surgical exposure. Open shoulder surgery is challenging because the deltoid and rotator cuff musculature envelop the joint, and in most approaches, exposure is limited by the proximity and importance of the axillary nerve. An understanding of the importance of the deltoid and the rotator cuff for glenohumeral function has led to a progression of innovative, advanced, and less invasive approaches to the shoulder. Various advantages, disadvantages, and risks are encountered when performing deltopectoral, deltoid-splitting, and posterior approaches to the glenohumeral joint, with variations of each approach and techniques to extend them and maximize exposure. The ability to perform each of these exposures provides the surgeon with the flexibility to best address the widest variety of pathology.

Advantage of minimally invasive lateral approach relative to conventional deltopectoral approach for treatment of proximal humerus fractures

Background

Despite the wide application of open reduction and internal fixation with locking plates for the treatment of proximal humeral fractures, the surgical invasive approach remains controversial. This study aimed to evaluate the pros and cons of the minimally invasive lateral approach for the treatment of proximal humeral fracture (PHF) in comparison with the deltopectoral approach.

Material/Methods

All patients who sustained a PHF and received open reduction and internal fixation (ORIF) surgery with locking plate through either minimally invasive subacromial approach or conventional deltopectoral approach between January 2008 and February 2012 were retrospectively analyzed. Patients were divided into the conventional group and min-group according to the surgical incision. Surgery-related information, postoperative radiography, complications, and shoulder functional measurement scores in a 2-year follow-up were collected and evaluated.

Results

Ninety-one patients meeting the inclusion criteria were included in this study. We observed a significant difference in both surgery time (81.8±18.3 vs. 91.0±18.4) (p=0.021) and blood loss (172±54.2 vs. 205±73.6) (p=0.016) between the min-group and conventional group. Compared to the conventional group, the min-group had significantly better Constant-Murley score and DASH score at early follow-up (p<0.05) and higher patients satisfaction rate (8.1±1.1 vs. 7.6±1.2) (p= 0.019). The multiple linear regression analysis indicated that age, PHF types, surgical groups, surgery time, and blood loss have significant effect on the activity of affected shoulder in both abduction and forward flexion (p<0.05) except for gender factor. While larger range of movement of the affected shoulder, mainly in the 2-part and 3-part fractures, was observed in the min-group, the conventional group obtained better movement in the 4-part fractures.

Conclusions

The minimally invasive lateral approach is the optimal alternative for the treatment of Neer’s type 2 and 3 proximal humerus fractures.

Management of proximal humerus fractures in adults

The majority of proximal humerus fractures are low-energy osteoporotic injuries in the elderly and their incidence is increasing in the light of an ageing population. The diversity of fracture patterns encountered renders objective classification of prognostic value challenging. Non-operative management has been associated with good functional outcomes in stable, minimally displaced and certain types of displaced fractures. Absolute indications for surgery are infrequent and comprise compound, pathological, multi-fragmentary head-splitting fractures and fracture dislocations, as well as those associated with neurovascular injury. A constantly expanding range of reconstructive and replacement options however has been extending the indications for surgical management of complex proximal humerus fractures. As a result, management decisions are becoming increasingly complicated, in an attempt to provide the best possible treatment for each individual patient, that will successfully address their specific fracture configuration, comorbidities and functional expectations. Our aim was to review the management options available for the full range of proximal humerus fractures in adults, along with their specific advantages, disadvantages and outcomes.

Open reduction internal fixation of proximal humerus fractures

The treatment of proximal humerus fractures continues to evolve. While the many of these injuries can be managed nonoperatively, a certain percentage require operative treatment. Open reduction internal fixation can offer excellent outcomes when performed in the appropriate patient and utilizing proper techniques. This article reviews the most up-to-date literature regarding all phases of proximal humerus fracture osteosynthesis, including diagnosis, imaging, anatomic considerations, surgical indications, fixation, and surgical outcomes.

Instability of the shoulder following seizures

Dislocation of the shoulder may occur during seizures in epileptics and other patients who have convulsions. Following the initial injury, recurrent instability is common owing to a tendency to develop large bony abnormalities of the humeral head and glenoid and a susceptibility to further seizures. Assessment is difficult and diagnosis may be missed, resulting in chronic locked dislocations with protracted morbidity. Many patients have medical comorbidities, and successful treatment requires a multidisciplinary approach addressing the underlying seizure disorder in addition to the shoulder pathology. The use of bony augmentation procedures may have improved the outcomes after surgical intervention, but currently there is no evidence-based consensus to guide treatment. This review outlines the epidemiology and pathoanatomy of seizure-related instability, summarising the currently-favoured options for treatment, and their results.