56: Percutaneous Pinning of Bennett Fracture and Open Reduction and Internal Fixation of Rolando Fracture

Procedure 56 Percutaneous Pinning of Bennett Fracture and Open Reduction and Internal Fixation of Rolando Fracture



Douglas Sammer




Indications


Figures 56-9 through 56-11 provided courtesy of Kevin C. Chung, MD; Figures 56-14 through 56-17 provided courtesy of Sandeep J. Sebastin, MD.



image If the fracture is nondisplaced at initial presentation (uncommon), it can be treated with splint or cast immobilization for 6 weeks, followed by protected motion.


image Surgery is indicated for failure to maintain acceptable reduction with splint or cast (articular step-off of <1 mm).


image Most Bennett and Rolando fractures are unstable and require surgical intervention.


image In most cases, closed reduction and percutaneous pinning is indicated for Bennett fractures.


image Open reduction is indicated when reduction cannot be achieved by closed means (more common with Rolando fracture).


image If open reduction is required, large fragments can be fixated by a variety of methods (plate, lag screw, percutaneous K-wires), whereas small fragments are best treated with K-wire fixation.



Examination/Imaging



Clinical Examination




image Standard sensory, motor, and vascular examination of the thumb


image Examination for lacerations that may indicate open fracture



Imaging




image Three view radiographs of the thumb: anteroposterior (Robert’s view), lateral, and oblique


image Computed tomography rarely indicated



Surgical Anatomy




image A Bennett fracture is a two-fragment intra-articular thumb metacarpal base fracture.


image A Rolando fracture is a three-fragment intra-articular thumb metacarpal base fracture.


image The thumb carpometacarpal (CMC) joint geometry is similar to two interlocking saddles, with their surfaces at 90 degrees to each other.


image The volar beak ligament is deep to the superficial anterior oblique ligament (SAOL) and is an important stabilizer of the thumb CMC joint.


image In a Bennett fracture, the volar beak ligament stabilizes the Bennett fragment, which is located volarly and ulnarly.


image The larger fragment, consisting of the remainder of the metacarpal, must be reduced to the Bennett fragment.


image The abductor pollicis longus (APL) tendon inserts on the dorsal base of the thumb metacarpal and causes dorsal subluxation and proximal displacement of the metacarpal (Fig. 56-1).


image The adductor pollicis inserts on the metacarpal shaft and causes CMC flexion and adduction (see Fig. 56-1).


image In a Bennett fracture, the metacarpal is supinated, adducted, and flexed, with proximal displacement and dorsal subluxation of the base.


image

FIGURE 56-1



Positioning




image The patient is supine.


image A pneumatic tourniquet is placed on the arm in case closed reduction is not possible and open reduction is required.


image The extremity is placed on a hand table, with the thumb pointing upward.


image The surgeon or assistant placing the K-wires sits at the patient’s axilla, facing the palm.


image The surgeon or assistant performing the reduction sits at the patient’s shoulder, facing the dorsum of the hand.



Exposures




image If open reduction is required, the exposure is through a modified Wagner incision (Fig. 56-2).


image The longitudinal limb of the incision is along the glabrous/nonglabrous skin border.


image At the thumb base, the incision turns ulnarly and extends to the flexor carpi radialis (FCR) tendon.


image Dissection is carried down to the border of the thenar musculature, protecting sensory nerve branches in the subcutaneous tissue (Fig. 56-3).


image A no. 15 blade is used to elevate the thenar muscles off of the metacarpal base and trapezium (Fig. 56-4).


image The APL tendon is reflected ulnarly.


image The joint is then exposed with a transverse capsulotomy, in the interval between the APL and the reflected thenar musculature (Fig. 56-5).


image

FIGURE 56-2


image

FIGURE 56-3


image

FIGURE 56-4


image

FIGURE 56-5



Pearls




It is important not to extend the Wagner incision ulnar to the FCR tendon, to avoid injury to the palmar cutaneous branch of the median nerve.


It is important to protect sensory nerves, such as the superficial sensory branches of the radial nerve, and smaller branches of the lateral antebrachial cutaneous nerve (LABC).


Fluoroscopy can be used to confirm joint location before capsulotomy.



Pitfalls




Injury to the palmar cutaneous branch of the median nerve by extending the incision ulnar to the FCR.


Injury to the LABC or superficial sensory branch of the radial nerve.


Excessive soft tissue elevation at the metacarpal base resulting in disinsertion of the APL—care should be taken to preserve the APL insertion.

Related posts:

34: Reconstruction of the Central Slip with the Transverse Retinacular Ligament for Boutonnière Deformity 32: Crossed Intrinsic Tendon Transfer 26: Reconstruction of Key Pinch in Tetraplegia Patients 33: Correction of Swan-Neck Deformity in the Rheumatoid Hand 50: Open Reduction and Internal Fixation of Phalangeal Shaft Comminuted Fractures 30: Synovectomy

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Mar 5, 2016 | Posted by in Hand surgery | Comments Off on 56: Percutaneous Pinning of Bennett Fracture and Open Reduction and Internal Fixation of Rolando Fracture

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