17 Radial Styloidectomy David M

17 Radial Styloidectomy David M. Kalainov, Mark S. Cohen, and Stephanie Sweet xcision of the radial styloid gained recognition osteotomy removed 92% of the radioscaphocapitate in 1948 when Barnard and Stubbins1 reported on and 21% of the long radiolunate ligament origins. The Eten scaphoid fracture nonunions treated with transverse osteotomy was the most invasive, detach- bone grafting and radial styloidectomy. The procedure ing 95% of the radioscaphocapitate and 46% of the has since been advocated to address radioscaphoid long radiolunate ligament origins. arthritis developing from a variety of injuries, includ- In another cadaveric model, Nakamura et al19 ex- ing previous fractures of the radial styloid and scaphoid, amined the effects of increasingly larger oblique sty- and arthritis related to posttraumatic scapholunate loidectomies on carpal stability. They concluded that instability.2–8 the procedure should be limited to a 3- to 4-mm bony Resection of the radial styloid has also been a use- resection. With axial loading, significantly increased ful adjunct to other procedures where there is poten- radial, ulnar, and palmar displacements of the carpus tial for impingement between the styloid process and were detected after removing 6-mm and 10-mm sty- distal scaphoid or trapezium.9–15 Authors have in- loid segments. The 6-mm cut violated the radio- cluded discussion of successful radial styloidectomy scaphocapitate ligament origin, whereas the 10-mm in descriptions of proximal row carpectomy, mid- cut removed the radioscaphocapitate and a portion of carpal arthrodesis, and triscaphe fusion procedures. the long radiolunate ligament origins. Only an in- On occasion, an individual may be too physically un- significant change in carpal translation was detected fit or unwilling to undergo an extensive operation to after a 3-mm osteotomy. address a symptomatic scaphoid nonunion or scapho- Other ligament attachments to the radial styloid lunate dissociation. A limited radial styloidectomy include the radial collateral ligament, the dorsal ra- may be a reasonable alternative in these cases. diocarpal ligament, and the radioscapholunate ligament.16 The radial collateral ligament originates radi- ally from to the tip of the styloid process and inserts ANATOMY into the waist and distal pole of the scaphoid. This structure represents the lateralmost margin of the ra- The radial styloid is positioned slightly volar to the dioscaphocapitate ligament and is removed in all sty- midcoronal plane of the radius. The bony excrescence loidectomy procedures. No adverse effects have been is the origin for the palmar extrinsic ligaments inte- reported in the literature. The dorsal radiocarpal liga- gral to carpal stability.16–18 The radioscaphocapitate ment has a broad origin from the distal radius, begin- ligament averages 7 mm in width and originates only ning radial to the level of Lister’s tubercle and cours- 4 mm from the tip of the styloid process. The long ra- ing distally to its insertion into the triquetrum. diolunate ligament is approximately 10 mm wide and Violation of a portion of the dorsal radiocarpal liga- starts 10 mm proximal to the tip of the styloid (Fig- ment following styloidectomy may potentially affect ure 17.1). carpal stability, but this has not been described. The Three basic types of styloid osteotomies have been radioscapholunate ligament is a vascular structure described: short oblique, vertical oblique, and trans- with limited mechanical function. The ligament orig- verse (Figure 17.2). The potential for symptomatic inates from the palmar aspect of the distal radius, in carpal instability has been associated with the size and between the long and short radiolunate ligaments, and shape of the excised bone fragment. Siegel and Gel- merges with the scapholunate interosseous ligament berman18 performed a cadaveric study to assess the ef- distally. fect of these three styloidectomy configurations on extrinsic carpal ligament integrity. The short oblique osteotomy was the least damaging, with removal of OPEN TECHNIQUE only 9% of the radioscaphocapitate origin; this styloidectomy was found to leave the long radiolunate The radial styloid may be excised as an adjunct to an- ligament attachment site intact. The vertical oblique other carpal procedure; the styloid is approached 134 CHAPTER 17: RAD IAL STYLOID ECTOMY 135 FIGURE 17.3. Exposure for an open radial styloidectomy. FIGURE 17.1. The radioscaphocapitate and long radiolunate ligament origins. teotome is used to remove 3 mm to 4 mm of the tip at an oblique angle (Figure 17.4). The cut should be through the same incision or a separate incision in parallel to the projected course of the radioscapho- these cases. With an isolated styloidectomy, a straight capitate ligament and perpendicular to the distal ra- incision is made between the first and second exten- dius articular surface (Figure 17.5). sor tendon compartments (Figure 17.3). The incision Periosteum is reapproximated over the debrided is centered over the tip of the styloid process, with styloid using absorbable sutures. The skin edges are care taken to protect the dorsal branch of the radial repaired with subcuticular sutures in an effort to min- artery and small branches of the radial sensory and imize scar formation. A bulky gauze dressing is ap- 13 lateral antebrachial cutaneous nerves. plied, and the wrist is supported in neutral alignment The extensor retinaculum and periosteum are in- with a volar plaster splint. cised longitudinally over the palpable styloid. The tip is exposed by subperiosteal dissection, preserving the palmar attachments of the radioscaphocapitate and ARTHROSCOPIC TECHNIQUE long radiolunate ligaments. A small, straight os- Finger traps are placed over the index and long find- ers, and the hand is suspended in an overhead traction FIGURE 17.2. Three radial styloidectomy configurations: short FIGURE 17.4. Excision of 3-mm bone fragment from the tip of the oblique, vertical oblique, and transverse. radial styloid. 136 D AVID M . KALAINOV, MARK S. COHEN, AND STEPHANIE SWEET FIGURE 17.5. Fluoroscopic image of the wrist following an oblique radial styloidectomy. FIGURE 17.7. Resection tool in the 1-2 portal and arthroscopic camera in the 3-4 portal. device. The arm is secured to the extremity table with a well-padded strap for countertraction. The major ex- subchondral bone. Use of a laser device may also be ternal landmarks and the positions of the portals that considered.20 The radioscaphocapitate and long ra- may be used in examining the wrist and performing diolunate ligaments are visualized directly with the the styloidectomy are shown in Figure 17.6.14,15 camera and adequate bone resection is confirmed with Eight to 10 pounds of traction are applied to the a mini-fluoroscopy unit (Figure 17.8). The procedure fingers to distract the wrist joint. The 3-4 portal is es- may be converted to an open technique if visualiza- tablished to accommodate the arthroscopic camera. tion is compromised. Outflow is achieved by placing an 18-gauge needle or The portal sites are either left open or closed with small plastic cannula through the 6-U portal. A com- sutures. A bulky gauze dressing and volar plaster plete examination of the wrist is performed. splint are applied with the wrist in neutral alignment. The 1-2 portal is then established for access to the radial styloid (Figure 17.7). A limited resection of 3 mm to 4 mm of the styloid tip is performed using a REHABILITATION covered bur (2.9 mm to 3.5 mm) and/or full-radius shaver (2 mm to 2.9 mm). A small osteotome or Following an isolated radial styloidectomy, the dress- pituitary rongeur may be helpful in removing hard ing, splint, and sutures are removed after 1 week. A FIGURE 17.6. Anatomic landmarks and portal sites for an arthro- FIGURE 17.8. Fluoroscopic image of the wrist during an arthroscopic wrist examination and radial styloidectomy. scopic radial styloidectomy. CHAPTER 17: RAD IAL STYLOID ECTOMY 137 gradual return to work and sport activities is permit- both patients presented with scaphoid nonunions. ted. Assistance from a hand therapist may be helpful Temporary wrist immobilization was implemented for instruction on wrist motion and grip strengthen- postoperatively in all cases. ing exercises. The period of wrist immobilization will The mean follow-up period for these 7 patients was be necessarily extended if a concurrent procedure pre- 29 months (range 3 to 57 months). The Mayo modi- cludes early joint motion. fied wrist scores21 increased from an average of 62 points preoperatively to 75 points postoperatively. Two patients reported no residual pain, and 5 patients COMPLICATIONS described only mild, occasional pain. Six patients re- turned to regular employment activities, whereas one Complications inherent to any orthopedic procedure patient was able to work but was unemployed. None apply to both open and arthroscopic radial styloidec- of the patients described difficulty performing activi- tomies (e.g., infection, joint stiffness, keloid forma- ties of daily living. tion). Specific problems that may result from a radial styloidectomy include injury to the dorsal branch of the radial artery and neuropraxia or neurotmesis of lo- CONCLUSION cal sensory nerves (i.e., dorsal branches of the radial sensory and lateral antebrachial cutaneous nerves). A Arthroscopic radial styloidectomy is a useful treatment complex regional pain syndrome may develop follow- for symptomatic arthritis localized to the distal ra- ing any nerve injury, necessitating intensive therapy dioscaphoid articulation, either as an isolated technique and pain management intervention. An incomplete ra- or as an adjunct to another carpal procedure. The pro- dial styloidectomy may also be problematic, with per- cedure is minimally invasive with the potential for tem- sistent complaints of radial-sided wrist pain. Exces- porary pain relief and improved hand function. The de- sive bony resection is potentially disastrous, resulting tails of the technique are important to review in order in ulnar translation of the carpus and symptoms of to avoid injury to cutaneous nerves, the dorsal branch wrist joint instability.

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