Arthroscopic-Assisted Management of Acute Scaphoid Fractures

Fig. 5.1

The patient presented to the orthopedic clinic 1 week later with continued complaints of pain and swelling of the left wrist. There was less clinical deformity. He still had complaints of mild paresthesias over the median nerve which had significantly improved since the reduction .

Physical Assessment

Physical examination revealed moderate swelling of the wrist. He was point tender to palpation over the anatomic snuff box and the dorsal aspect of the scaphoid. He was also very point tender over the lunotriquetral (LT) interval. He had pain with a LT shuck maneuver. Sensation was grossly intact, including in the median nerve distribution. Digital range of motion was intact, but wrist range of motion was very limited due to pain .

Diagnostic Studies

Radiographs obtained in the clinic revealed the reduced trans-scaphoid perilunate dislocation. There was some widening of the LT interval, and the fracture line of the scaphoid was apparent on all views.

Diagnosis

Trans-scaphoid perilunate dislocation

Management Options

Traditional management would include open reduction and internal fixation of the scaphoid LT ligament repair and stabilization of the LT interval with Kirschner wires (K-wires) [1].The K-wires would be at risk for infection as they would be exiting the skin and would hamper rehabilitation. Other options besides open reduction were discussed including arthroscopic fixation of the fracture of the scaphoid and stabilization of the LT interval with a scapholunate intracarpal (SLIC) screw [2].

Management Chosen

Arthroscopic fixation of the scaphoid and percutaneous stabilization of the LT interval allows for earlier range of motion as compared to K-wire fixation and may also lead to decreased scarring for potentially increased range of motion. The SLIC screw (Acumed, Hillsboro, OR) is a screw that freely rotates at its midsection (Fig. 5.2). In addition, it has approximately 20° of toggle between the proximal and distal ends. When the screw is inserted, it allows a more normal rotation between the involved carpal bones. This allows the screw to be placed for a prolonged period of time, while the interosseous ligament heals allowing near-normal motion of the carpal bones with range of motion of the wrist. The screw can be taken out at approximately 6–9 months if the patient is symptomatic .

Fig. 5.2

Surgical Technique

After general anesthesia is obtained, the patient is placed in supine position with the left arm outstretched on a hand table. A sterile tourniquet is applied at the level of the upper arm just proximal to the elbow crease. By placing the tourniquet more distal than normal at the level of the elbow crease allows better support of the upper extremity in the traction tower. The Acumed traction tower (Acumed, Hillsboro, OR) is set up on the hand table with the forearm plate in the dorsal position for easier removal later (Fig. 5.3). Traditionally, the forearm plate is placed on the volar aspect of the forearm for stability of the wrist which is slightly flexed in the traction tower. However, by placing the forearm plate dorsally, this allows for easier removal when the arm is flexed during the operative procedure. All bony prominences are well padded about the arm and forearm, and the skin does not touch the traction tower itself. The joint of the tower arm is set at the same level of the wrist joint, and the wrist is flexed approximately 30°. Finger traps are placed along the index and long fingers, and the wrist is suspended with approximately 10–15 lb of traction . It is important that the bend of the tower is at the level of the wrist to allow wrist flexion in this procedure.

Fig. 5.3

Fluoroscopic view of placing the cannulated SLIC screw (Acumed, Hillsboro, OR) across the LT interval. (Published with kind permission of © William B. Geissler and Jared L. Burkett, 2015. All rights reserved)

An 18-gauge needle is then initially placed in the 6U portal for inflow, and approximately 5–10 ccs of sterile lactated Ringers is injected into the radial carpal joint. An 18-gauge needle is then inserted into the radial carpal joint at the 3–4 portal (between the third and the fourth dorsal compartments) 1 cm distal to Lister’s tubercle. It is important to place the needle at approximately 10° of angulation and volarly to match the volar tilt of the distal radius. The 3–4 portal is located down the radial border of the long metacarpal. Once the ideal location of the 3–4 portal is identified, the skin is incised by pulling the skin against the tip of a no. 11 blade and blunt dissection is carried down with a hemostat to the level of the joint capsule. The 2.7-mm arthroscope with a blunt trocar is then introduced into the 3–4 portal .

Evaluation of this patient’s radiocarpal space with the arthroscope in the 3–4 portal showed pristine articular cartilage to the scaphoid, lunate, and the distal radius. The scapholunate interosseous ligament was completely intact. Under direct visualization with the arthroscope in the 3–4 portal, an 18-gauge needle is placed to localize the 6R portal. This enters the joint just distal to the articular disk of the triangular fibrocartilage complex. The arthroscope with a blunt trocar is introduced into the 6R portal. Evaluation of the LT interval revealed a Geissler Grade IV tear of the LT interosseous ligament. Evaluation of the articular disk showed it to be intact with no tear.

The arthroscope was then introduced into the radial midcarpal space to evaluate the midcarpal joint. Evaluation of the radial midcarpal space revealed the fracture at the waist of the scaphoid. It was displaced. Evaluation of the scapholunate interval with the arthroscope in the midcarpal space showed it to be tight and congruent with no step-off. Continued evaluation of the ulnar side of the wrist again showed widening and separation of the LT interval consistent with a Geissler Grade IV injury of the LT interosseous ligament .

Carpal instability is best arthroscopically reduced by looking across the wrist to evaluate the rotation of the carpal bones. In this instance, the arthroscope was in the 3–4 portal. Joysticks were placed percutaneously into the lunate and triquetrum. Once the interval was anatomically reduced, a guide wire was placed in oscillation mode percutaneously through the triquetrum into the lunate. Using the oscillation mode helps protect the dorsal sensory branch of the ulnar nerve . The wrist tower is then flexed, confirming the ideal location of the guide wire in the LT interval with fluoroscopy. The guide wire is aimed toward the radial proximal corner of the lunate. Following confirmation of the ideal position of the guide wire, a 1-cm skin incision was made around it. A cannula with a blunt trocar is introduced to the level of the joint capsule to protect the dorsal sensory branch of the ulnar nerve. The SLIC cannulated drill was then placed over the guide wire and advanced between the triquetrum and the lunate, so the step of the drill is between the lunate and the triquetrum as confirmed under fluoroscopy. The length of the proximal portion of the screw was then measured directly by the drill under fluoroscopy. There are three optional lengths of the proximal portion of the screw. In this manner, the length of the portion is determined so that it will be flushed with the carpal bones to aid in its removal in the future. In this instance, a 25-mm SLIC screw was measured from the drill. This screw was inserted over the guide wire so that the interval of the screw would be exactly between the lunate and the triquetrum (Fig. 5.4). This will allow for near-normal carpal motion of the bones with range of motion of the wrist .