Midshaft humerus fractures Abel David, MS-III University of Virginia School of Medicine August 4, 2016

Epidemiology Accounts for approximately: 3% of all fractures 20% of humeral fractures Primary mechanisms of humerus fractures include: Motor vehicle crashes Violent injury Accidental falls In 3-year epidemiological study, with n=249 consecutive humeral shaft fractures, demonstrated a bimodal distribution: A peak in the 3rd decade, majority males, high energy A larger peak in the 7th decade, majority females, low energy

Relevant Anatomy Muscles: Nerves: Artery: Insertion of: pectoralis major, deltoid, and coracobrachialis Origin of: brachialis, triceps, and brachioradialis Nerves: Radial nerve Courses along spinal groove 14 cm proximal to lateral epicondyle 20 cm proximal to medial epicondyle Artery: Brachial artery

Deforming forces Major deforming forces include the deltoid m. and pectoralis major m. Different displacement of the fracture segments based on the location of the fracture relative to the insertion of deltoid and pectoralis major http://clinicalgate.com/humerus-and-elbow/

Case Report: M.B. 19 y/o F M.B. is a 19-year-old female who presented to the UVA ED as a trauma alert, she was the restrained occupant of a high-speed, rollover MVC. Her orthopedic injuries included: right radial shaft fracture, left humeral shaft fracture, and right forearm laceration with exposed FDS muscle/tendon. No PMHx or PSHx

Case Report: M.B. 19 y/o F Right Forearm Left Arm Right forearm tender to palpation, mild deformity, 6cm laceration with exposed muscle belly Intact motor to AIN/PIN/U nerves SILT M/R/U nerve distributions Compartments soft and compressible 2+ radial pulse Left Arm No deformities noted, no open wounds Motor intact to wrist flexion/extension, finger flexion/extension/intrinsics Intact motor to AIN/PIN/U nerve SILT M/R/U distributions

Injury Imaging AP Lateral

Case Report: M.B. 19 y/o F Then, an anterolateral approach to the humerus was made and interval between the biceps and brachialis was carefully dissected. Biceps was retracted medially and brachialis was split along the lateral 2/3 of the muscle down to bone. We immediately encountered fracture hematoma. Dissection was carried more proximally and part of the deltoid insertion was reflected for plate placement. We palpated and visualized the fracture fragments and the radial nerve, which was not in the fracture site. We then irrigated and delineated the fracture edges and reduced the fracture using reduction forceps. We then reduced the proximal shaft fragment to distal shaft fragment using reduction forceps. We then placed a synthes narrow 4.5mm 7-hole LCP plate and secured it provisionally with a k wire. We confirmed location and position with fluoro. We then placed two proximal cortical screws, then 3 distal cortical screws, then 2 more proximal cortical screws. Fluoro was then taken again and we confirmed satisfactory reduction of fracture fragments and adequate plate positioning.

Post-ORIF Imaging

Follow-up 2 weeks later Remained NWB in bilateral UE with a splint on her right forearm and a sling on her left arm Pain was well controlled, no signs or symptoms concerning for site infection, no constitutional symptoms, ROM, strength, neurovascular status continue to remain stable Imaging confirmed no hardware issues or fracture displacement

Clinic Follow Up Imaging AP Lateral

Classification No classification scheme of humeral shaft fractures Traditionally described by: Location: proximal, middle, or distal Type of fracture line: transverse, oblique, spiral, comminuted, or segmental Open vs. closed AO/OTA fracture descriptions

Classification Bone 1, Fracture Location 2 Simple transverse humeral shaft fracture, OTA Classification: 12-A3

Holstein-Lewis Fracture Named fracture of the humerus Spiral fracture of the distal 1/3 of the humeral shaft, associated with neuropraxia of the radial nerve http://spiralhumerusfracture.blogspot.com/ http://orthopodshsnz.blogspot.com/2013/01/houstein-lewis-fracture.html

Management Non-operative management Operative management Coaptation splint followed by functional brace Operative management Closed reduction, intramedullary nailing Open reduction internal fixation

Non-operative Management Indicated in majority of humeral shaft fractures Criteria for acceptable alignment: < 20˚ of anterior angulation < 30˚ of varus/valgus angulation < 3 cm of shortening Absolutely contraindicated in brachial plexus injury, vascular injury requiring repair, and severe tissue/bone loss

Operative management, ORIF Indications: Open fracture Vascular injury requiring repair Brachial plexus injury Compartment syndrome Ipsilateral forearm fracture (floating elbow) Relative: polytrauma

Operative management, IMN Relative indications Pathologic fractures Segmental fractures Severe osteoporotic bone

Non-operative v. operative Plate fixation vs. functional bracing in 51 consecutive patients (19 with plate and 21 with functional bracing) – Jawa et al. Demonstrated that operative treatment achieved more predictable alignment and quicker return of function There was a higher risk of iatrogenic radial nerve injury, infection, and increased reoperation rates Functional bracing was associated with skin problems, and angular deformity but function and ROM were usually acceptable

ORIF v. IMN Similar numbers of patients had nonunion, infection, and iatrogenic nerve injury Mean hospital stay, blood loss, and operation time were not significantly different In two RCTs, the reoperation risk for IMN was three times that for plates (Changulani et al. Chapman et al.) In one RCT, patients who received IMN had more shoulder pain and decreased shoulder ROM (Changulani et al.)

Complications Malunion Non-union Radial nerve palsy Brachial artery injury

Prognosis of Humeral Fractures Non-union is associated with: Long oblique fracture pattern Alcohol abuse Obesity Comminuted fractures Open fractures Fractures in the middle third of the humeral shaft Transverse fractures

Summary Relatively common fracture seen in 3rd decade males with high energy mechanisms and in 7th decade females with low energy mechanisms Neurovascular assessment is important, especially the evaluation of radial nerve function and for brachial artery injury Majority are managed non-operatively with good outcomes with a coaptation splint and functional brace Operative management has a more predictable alignment and quicker return of function, but higher rates of iatrogenic nerve injury/infection Additional RCTs are still needed to further validate

References Tytherleigh-Strong G, Walls N, McQueen MM (1998) The epidemiology of humeral shaft fractures. J Bone Joint Surg Br; 80:249-53. Houwelingen AV, McKee MD (2004) Management and Complications of Humeral Shaft Fractures. University of Toronto Medical Journal; 81:96102. Jawa A, McCarty P, Doornberg J, et al (2006) Extraarticular distal third diaphysealfractures of the humerus. A comparison of functional bracing and plate fixation. J Bone Joint Surg Am; 88:23437. Changulani M, Jain UK, Keswani T (2006) Comparison of the use of the humerusintramedullary nail and dynamic compression plate for the management of diaphysealfractures of the humerus. A randomised controlled study. Int Orthop. McCormack RG, Brien D, Buckley RE, et al (2000) Fixation of fractures of the shaft of the humerus by dynamic compression plate or intramedullary nail. A prospective, randomised trial. J Bone Joint Surg Br; 82:3369. Chapman JR, Henley MB, Agel J, et al (2000) Randomized prospective study of humeralshaft fracture fixation: intramedullary nails versus plates. J Orthop Trauma; 14:1626. https://www2.aofoundation.org/wps/portal/surgery http://www.orthobullets.com/