Fractures of the Pelvis and Scapula

Fractures of the Pelvis and Scapula

Overview of Fractures of the Pelvis

• Usual causes:

  • 16% of all fractures in dogs.

  • 25% of all fractures in cats.

  • Often associated with multi-system trauma, commonly seen in hit-by-car (HBC) incidents.

• Associated Injuries:

  • Urinary tract injuries occur in 39% of cases.

  • Nerve entrapment, particularly of the sciatic or lumbosacral nerves.

  • Bilateral injuries are more common compared to unilateral injuries.

• Anatomical Consideration:

  • The pelvis is regarded as a rigid box, often exhibiting multiple fractures in complex cases.

Conservative vs. Surgical Management

• Conservative Management:

  • Applicable for less severe injuries, including:

  • Ischium fractures.

  • Pubic fractures.

  • Mild unilateral sacroiliac (SI) luxations.

  • Requirements for Success:

  • High-quality nursing care.

  • Activity restriction for the patient.

  • Incorporation of physical therapy as needed.

• Surgical Management:

  • Indicated for more severe injuries including:

  • Articular fractures.

  • Iliac fractures.

  • Most cases of SI luxations.

  • Instances of severe pain.

  • Significant pelvic canal narrowing.

  • Cases involving nerve entrapment.

Sacroiliac Luxation

• Prevalence:

  • About 75% of sacroiliac luxations are unilateral, with many cases presenting with contralateral fractures.

  • Affected animals often demonstrate non-weight bearing (NWB) on the injured side.

• Indications for Surgical Repair:

  • Severe displacement of the injury.

  • Severe pain experienced by the animal.

  • Damage or entrapment of nerves adjacent to the injury site.

  • Requirement for stability to facilitate other repairs.

  • Narrowing of the pelvic canal.

Fractures/Luxation of Sacroiliac Joint

• Displacement Characteristics:

  • Displacement observed with a visible step at the joint, without accompanying fractures of the sacrum.

• Surgical Approaches:

  • Dorsal Approach:

  • Considered the best option, allowing direct visualization of the sacral wing, a critical anatomical landmark.

  • Ventral Approach:

  • Utilized when there is an ipsilateral ilial fracture, although uncommon.

  • This approach does not allow visualization of the sacral wing.

Surgical Anatomy Overview

• Lag Screw Fixation Technique:

  • A drill hole must be made 2mm cranial and 2mm dorsal to the lesser curvature of the sacrum, ensuring perfect parallel alignment.

  • A second screw is designated as a position screw.

Importance of Proper Surgical Technique

• Goals of the Procedure:

  • Utilize lag screws to engage at least 60% of the sacral body.

  • Aim for a surgical reduction of at least 90%.

• Importance of Good Reduction:

  • Without proper reduction or bone purchase, 38% of screws may loosen or break.

  • With good reduction and adequate bone purchase, only 7% may experience issues.

• Considerations in Anatomy:

  • Sacral body thickness is generally about 1 cm in most mature canines.

Bilateral Sacroiliac Luxation Treatments

• Treatment options include:

  • Use of 2 lag screws.

  • A single screw that lags one side while serving a positional function on the other side.

  • Implementation of a transiliac pin for stabilization.

Fractures of the Ilium

• Functional Anatomy:

  • Plays a crucial role in transmitting major forces from the pelvic limb to the axial skeleton.

  • Commonly presents as oblique fractures of the mid-body region.

• Potential Complications:

  • Can cause damage to the lumbosacral nerve trunk.

  • Often displaced medially and cranially, compromising the pelvic canal.

• Surgical Approaches:

  • Lateral approach involving the ilial wing and greater trochanter, performing a gluteal roll-up.

  • Possible extension to a dorsal approach if there is an acetabular fracture.

Reduction and Repair Techniques

• Reduction Methodology:

  • Lever bone segments into reduction.

  • Utilize the trochanter for mechanical advantage.

  • Apply dynamic compression plates (DCP) on the lateral surface, typically 1/3 from the dorsum.

Lag Screw Fixation Details

• Applicable in large dogs only.

• It is common to use 2-3 lag screws for oblique fractures.

• Placement is recommended from the ventral aspect.

• Research indicates that lag screw fixation is generally more rigid compared to plate fixation.

Fractures of the Acetabulum

• Prevalence:

  • Account for 12% of all pelvic fractures.

  • Primary cause is hit-by-car (HBC) accidents.

  • 50% of cases often have concurrent injuries.

• Classification of Fractures:

  • Categories include:

  • Cranial.

  • Central.

  • Caudal (area most weighted during standing).

Management Strategies for Acetabular Fractures

• Surgical vs. Conservative:

  • Most acetabular fractures require surgical management due to their articular nature.

  • Conservative management may be suitable for young patients with stable fractures involved in the non-weight bearing (NWB) aspect of the acetabulum (caudal). This includes:

  • Placement in Ehmer's sling for a duration of 10-14 days.

  • Note: Such conservative approaches are still considered controversial.

Surgical Approach to Acetabular Fractures

• Procedure Considerations:

  • Osteotomy of the greater trochanter is necessary to expose the joint via a longitudinal incision.

  • Aiming for visualization of anatomical reduction to maintain blood supply to the neck of the femur, particularly in juvenile canines.

  • Enables improved closure of the joint to mitigate the risk of luxation.

• Note on the Round Ligament of the Femur:

  • Important for rotation; however, it does not prevent luxation.

Achieving and Confirming Reduction

• Employ Kern bone forceps on the ischium to provide caudal traction.

• Placing a Steinman pin in the ischium assists in stabilization during the procedure.

Surgical Repair of Acetabular Injuries

• Utilized Equipment:

  • An acetabular plate for dorsal surface application.

  • Offers the most accessibility and visibility for surgical intervention.

  • Supports anatomical reduction and induces compression at the site of injury.

• Procedure for Repair:

  • An associated tension band may be applied to secure an osteotomy.

Combined Acetabular and Ilial Fractures

• Implementation Strategies:

  • Utilization of a pre-contoured reconstruction plate.

  • Combinations of an acetabular plate with a dynamic compression plate (DCP).

  • Severely comminuted acetabular fractures may necessitate:

  • Femoral head/neck ostectomy.

  • Total hip replacement as a last resort.

Fractures of the Ischium and Pubis

• Prevalence:

  • These fractures typically occur in conjunction with ilial or acetabular fractures.

• Repair Indications:

  • Rarely is repair needed unless:

  • Fractures of the ischial tuberosity are present.

  • Cranial fractures impinge on the sciatic nerve.

  • Acetabular fractures combined with cranial fractures are identified.

Specific Strategies for Ischial Injuries

• Fractures of the Ischial Body:

  • Repair techniques may involve:

  • 2 or more Steinman pins.

  • Reconstruction plates for stabilization.

Ischial Tuberosity Avulsion Treatment

• Functional Importance:

  • This avulsion should be repaired to maintain proper function of the hamstrings.

• Techniques:

  • Use of diverging K-wires in fixation.

  • Lag screws are recommended for larger patients to ensure stability.

Managing Fractures of the Pubis

• Repair Considerations:

  • Surgical intervention is required if there is soft tissue herniation.

  • Repair at the pubic symphysis may be necessary using orthopedic wire for stability.

Overview of Scapula Fractures

• Prevalence:

  • Fractures of the scapula account for approximately 2.4% of all canine fractures.

• Etiology:

  • In canines, HBC is a primary cause.

  • In felines, penetrating wounds are more common.

• Concurrent Injuries:

  • About 50% of scapula fractures are accompanied by thoracic trauma, which may include:

  • Pulmonary contusions.

  • Pneumothorax.

  • Hemothorax.

  • Traumatic myocarditis.

Healing and Management of Scapula Fractures

• Healing Potential:

  • Healing is generally excellent due to:

  • An abundance of cancellous bone structure.

  • Intrinsic support from surrounding musculature enhancing stability.

  • Excellent extraosseous blood supply aiding recovery.

• Management Approach:

  • Conservative management is traditionally advocated for many fractures, which includes:

  • Closed reduction techniques and coaptation (splinting).

Classification of Scapular Fractures

• Anatomical Locations:

  • Spine and acromion.

  • Body of the scapula.

  • Neck of the scapula.

  • Supraglenoid tubercle.

  • Glenoid cavity.

• Types of Fractures:

  • SEA: Stable extra-articular fracture.

  • USEA: Unstable extra-articular fracture.

  • IA: Intra-articular fracture.

• Surgical Indications:

  • Surgical intervention is critical in cases involving:

  • Articular fractures.

  • Acromion fractures.

  • Neck and supraglenoid tubercle fractures.

Surgical Approaches to Scapular Fractures

• Approach to the Neck:

  • Requires an osteotomy of the acromion for access.

• Approach to the Supraglenoid Tubercle:

  • Involves an osteotomy of the greater tubercle.

• Approach to the Body:

  • A lateral approach is preferred over the spine, allowing for elevation of the supra- and infraspinatus muscles off the body while preserving the supraspinatus nerve.

Managing Acromion Fractures or Osteotomies

• Techniques for Stabilization:

  • Distractive forces from the deltoideus muscle necessitate stabilization.

  • Installation of 1-2 pin tension bands is advised for stability during healing.

Glenoid Tubercle Fracture Management

• Common Characteristics:

  • Distractive forces from the biceps brachii often lead to this type of fracture, which is frequent in young animals due to centers of ossification.

• Surgical Considerations:

  • An osteotomy of the greater tubercle may be indicated, along with options for lag screws or tension bands for stabilization.

Fracture of Scapular Neck Treatment

• Potential Complications:

  • This fracture can cause misalignment of the glenoid cavity.

• Repair Strategies:

  • Involve osteotomy of the acromion process with proper alignment of the glenoid cavity utilizing VCP, L or T plates.

  • Placement of screws targeting the neck and utilizing multiple screws for the body is essential, alongside cross pins in small breed dogs.

Glenoid and Scapular Neck Fracture Management

• Surgical Techniques:

  • Involve osteotomy of the greater tubercle and acromion with a well-placed lag screw applied from the cranial aspect.

  • Plate application is necessary for correction in the neck region to maintain alignment.

Management of Fractures of the Scapular Body

• Healing Expectations:

  • Scapular body fractures usually have the potential for self-healing without surgical intervention.

  • The use of a Velpeau sling may be applied for supportive management.

  • In cases that are comminuted or deemed severe, utilizing VCP placed at an angle to the spine may be necessary for surgical management.