Patient History and Physical Findings
History:
Physical Findings:
Aspiration and intra-articular block can be used to allow for the assessment of potential mechanical block to flexion-extension, or rotation (as well as diagnostic of a fracture with aspiration of hemarthrosis)
Imaging and Diagnostic Studies
Radiography:
- AP/Lat elbow, wrist, shoulder
- radiocapitallar view: patient is positioned as for a lateral view of the elbow, but the tube is angled 45 degrees toward the shoulder.
- Fat pad sign can be helpful if no fracture seen, but fat pad sign is present in some normal individuals
MRI:
- Itamura et al quatified associated injuries in 24 elbows with Mason type II or III fractures:
- MCL 54%
- LCL 80%
- osteochondral injury 29%
- capitellar bone bruise 94%
- loose bodies 92%
Classification
Mason Classification
Differential Diagnosis
Essex-Lopresti Fracture - radial head fracture, DRUJ disruption, and intraosseous membrane injury
Treatment
- Surgical Indications:
- Radial head excision can be considered if it is an isolated injury(i.e. there is not an Essex-Lopresti fracture).
- In the setting of an Essex-Lopresti fracture (radial head fracture, DRUJ disruption, and intraosseous membrane injury) proximal migration of the radius and a reduction in grip strength, valgus instability, posterolateral rotatory instability, heterotopic ossification, and post-traumatic arthritis of the ulnohumeral articulation may occur. Therefore it is recommended to either repair or replace the radial head.
- optimal scenarios include elderly, low energy injuries, no concomitant ligamentous injuries
- isolated, displaced two-part fractures are preferrably treated with ORIF
- Simple excision of fragments less than 1/3 of radial head may be considered if unrepairable.
- The radial head should be repaired or replaced when:
- There are associated soft tissue injuries at the elbow, including:
- Disruption of the anterior band of the MCL (secondary valgus instability)
- Essex-Lopresti Fracture (secondary longitudinal instability)
- Lateral collateral ligament (posterolateral rotatory instability; presence of radial head allows for proper tensioning of the LCL)
- Elbow dislocation (posterolateral rotatory instability, recurrent posterior dislocation)
- If there is a block to flexion/extension, or rotation
- Angulation more than 30o
- Depression of articular surface of more than 3 mm
- Greater than 1/3 of radial head involved
- Open reduction internal fixation is indicated for:
- Partial articular fractures with a single fragment
- Mason type 3 (complete articular) fractures with three or fewer fragments
. - ORIF is carried out in 70% of patients for whom it is intended due to the fact that there is often more comminution found intraoperatively than was apparent on preoperative radiographs. One must be prepared for a "plan B" replacement.
- Radial head replacement is recommended for:
- Tenuous fixation
- Mason type 3 fractures with more than three articular fragments.
- Advanced age, sedentary, smokers, patients on medications that impair healing (eg prednisone), significant medical comorbidities
- Irreparable cartilage injury
- patients with osteoporotic bone
General guidelines:
- Mason Type I: Splint or sling for a few days followed by early active range of motion
- Mason Type II:
- Without Essex- Lopresti
- Without mechanical block : as for type 1
- With mechanical block : excise fragment or ORIF
- With Essex- Lopresti
- ORIF or arthroplasty
- May need to pin radius and ulna
- Mason Type III:
- Without Essex- Lopresti or dislocation : excise
- With Essex- Lopresti : aim to retain the head if possible at all
- Mason Type IV
Treatment of Essex-Lopresti Injuries
- Closed reduction and possible pinning of the DRUJ
- ORIF vs. replacement of the radial head
Techniques:
- Arthroplasty:
- Over- or understuffing the radiohumeral joint by 2.5 mm or more significantly alters elbow kinematics and radiocaptiallar pressure . Overstuffing may lead to pain and early EJD, while undersuffing increases the risk of valgus instability.
- The plane of the articular surface of the radial head is located 0.9mm proximal to the plane of the lateral articular surface of the coronoid
- A visual lateral ulnohumeral joint gap seen intraoperatively is a reliable indicator of over-lengthening greater than 2mm. Radiographic asymmetry of the medial ulnohumeral joint is insensitive for detecting over-lengthening, as incongruity of ulnohumeral joint only occurs after over-lengthening of the radius by 6mm or more.
Figure: Overstuffed radial head replacement.
- voids caused by impacted fragments should be filled with cancellous autograft from the lateral epicondyle
Treatment of Pediatric Radial Head Fractures
- Acceptable angulation of 30o in young children (15o in older children more than 10 y/o)
- Corrects with remodelling with growth
- Can expect 10o correction
- If angulation is more than 30o, either :
- Manipulation under G/A
- Open reduction if more than 45o and irreducible
- Never perform radial head excision in the young as it leads to ulnar overgrowth
Pearls and Pitfalls
Tips and problems to avoid
Postoperative Care
Include immediate postoperative care and rehabilitation
Outcome
- In a 2 year followup of patients with comminuted radial head fractures treated with replacement (Grewal et al 2006)
- slight to moderate deficits in strength and range of motion persisted
- little clinical improvement is seen after 6 months
- mild arthritis developed in 19%
- The results of initial conservative management of Mason II and III fractures are no different to early excision
- Also the results of delayed excision of the radial head are satisfactory giving some justification for the initial closed treatment of these fractures with delayed excision of the radial head to be considered at a later date if needed as symptoms develop
Complications
- Heterotopic ossification
- risk factors:
- extensive muscle damage
- neurotrauma
- revisions
- Prophylaxis modalities
- radioulnar synostosis
- nonunion
- collapse
- DJD
- decreased range of motion
- loss of full extension most common
- Radial head overgrowth
- Premature physeal closure
- Avascular necrosis of the radial head
- Alteration in the carrying angle
- Neuromuscular problems (ulnar nerve problems with valgus)
References
