THUMB INJURIES BASE FRACTURES

– Written by Gustavo Vinagre, Flávio Cruz and Jonny K Andersson, Qatar

INTRODUCTION ANATOMY Clinical diagnosis is often difficult Acute traumatic fractures of the base of the The thumb metacarpal serves as the site of because of the rapid onset of edema which thumb are frequent and their consequences attachment for several tendons, including masks anatomical landmarks, hence the can affect the well-functioning of the thumb. the abductor pollicis longus (APL) at the importance of pain and sometimes a Handball players and football goalkeepers proximal base, the adductor pollicis (AP) discrete functional impairment. Inspection are prone to get these injuries. distally, and the thenar muscles volarly. may reveal shortening and adduction The first carpometacarpal (CMC) Joint stability is maintained by five primary of the thumb, and a ‘dinner fork’ type is vital to the function of the , and ligaments: the anterior-volar (beak), the deformity. Palpation may reveal a piano key trauma to the thumb CMC joint could led to posterior oblique, the dorsal radial, the (Tillaux’s) sign and the tension-compression two special entities: Bennett and Rolando anterior intermetacarpal ligaments and the manoeuvre in the axis of the thumb may fractures. They generally occur after trauma posterior intermetacarpal ligaments. reveal pistoning2. by compression along the axis of the thumb It is important to do a complete in flexion, such as falling on an outstretched HISTORY AND PHYSICAL ASSESSMENT neurovascular examination and to search hand or by direct trauma, for example when Fractures of the thumb CMC joint are the for associated conditions such as wrist saving a hard shot as goalkeeper. most common of all thumb fractures. ligamentous injuries. Neurovascular Bennett fractures are intra-articular Most of these fractures occur with direct injuries are uncommon but compartment fractures in which the metacarpal shaft is trauma to the thumb tip, often from a fall syndrome in the thenar region should be proximally and radially displaced by the or sports-related injury. These injuries are ruled out in higher-energy injuries. pull of the abductor pollicis longus (APL) more common in young males, and often Tendon function should be examined, tendon, leaving an intact ulnar fragment affect the dominant hand. It is important specifically the extensor pollicis longus (EPL), at the base of the thumb metacarpal, that to determine if the patient had pre-existing flexor pollicis longus (FPL), and extensor is held reduced by the strong volar beak basal joint arthritis, which will affect pollicis brevis (EPB). ligament (Figure 1A). treatment option and expected results1. Rolando fractures are complex intra- Common physical examination findings IMAGING articular fractures involving the base of include tenderness and ecchymosis Radiographs are the first-line imaging the thumb metacarpal that often have a surrounding the thumb CMC joint and the modality and should include AP, lateral, T- or Y-type pattern. These fractures are thenar, crepitus with attempted motion, and oblique views. Radiographs of the classically described as being three-part; instability, and a "shelf" deformity resulting contralateral, uninjured basal joint can be however, the name also applies to more from displacement of the metacarpal shaft helpful in certain cases as a template for the comminuted fracture variants (Figure 1B). dorsally. surgery.

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Figure 1: Schematic drawing of a typical Bennett fracture (A): unicondylar fracture of the base of the first metacarpal; and a Rolando fracture (B): multifragmentary fracture with the entire base of the base of the metacarpal being involved. Figure 2: Closed reduction of Bennett fractures is obtained by applying axial traction, palmar abduction, and pronation to the thumb metacarpal while providing pressure over the dorsal-radial metacarpal base. Figure 3: Schematic drawing of a Rolando fracture fixed with a plate.

Computed tomography (CT scan) may comminuted fractures. Particularly in In ORIF for Bennett fractures, the volar be indicated if a significant amount of Bennett fractures, closed reduction (Figure 2) thenar Wagner incision and the use of two articular comminution is present or when can be achieved and may be indicated if the 1.3 or 1.5 mm AO compact hand lag-screws is plain radiography is not fully clear for the ulnar fragment is small and if there is a recommended. That approach enables and understanding of the fracture pattern. A minimal displacement between the volar simplifies the exact anatomical reduction traction view may be helpful in Rolando-type ulnar fragment and the metacarpal shaft. and fixation. fractures in which nonoperative treatment However, there is a very low likelihood The main goals of surgery are to restore is being considered and tomography is not of maintaining reduction using closed the articular congruity of the thumb CMC available. reduction only in displaced fractures, joint and to align the first metacarpal base especially if there is a step-off of more than articular surface with the trapezium. If the DIFFERENTIAL DIAGNOSIS 2 mm. thumb CMC joint fracture is associated • De Quervain tenosynovitis or FPL Residual subluxation of the metacarpal with trapezial body fractures, the trapezial synovitis, after overuse among athletes, shaft leads to basal joint incongruity and articular surface should first be reduced such as goalkeepers. the potential for developing post-traumatic anatomically, before proceeding with the • Intraarticular radial plica. arthrosis. In addition, residual intra-articular thumb metacarpal fracture. • Thumb CMC joint ligamentous injury step-off greater than 1 mm predispose to the and instability development of arthrosis. POST-OPERATIVE CARE AND REHAB- • Basal joint degenerative joint disease. ILITATION • STT joint degenerative arthritis. SURGICAL TREATMENT A thumb splint is applied after the surgery • Trapezial body fracture. The majority of displaced Bennett in the operating room. It could be replaced • or non-union or fractures and almost all Rolando fractures with a removable custom-made brace (with scapholunate ligament injury. require surgery, with closed reduction the IP-joint free for range of motion training) and percutaneous Kirschner wire fixation after approximately 2 weeks, and should be CONSERVATIVE TREATMENT (under fluoroscopic guidance) or open maintained for 4 to 6 weeks, until fracture Due to the deforming forces that act on the reduction and internal fixation (ORIF) with union. Hand therapy should begin early (1 to fracture fragments, both injury patterns are plate (Figure 3) or screws (Figure 4). Bennett 2 weeks postoperatively) for thumb IP and usually unstable and difficult to reduce and fractures with small ulnar fragments MP joint mobilization and active range-of- stabilize by closed means only. Therefore, can be treated by closed reduction and motion exercises. nonoperative treatment with closed percutaneous pinning, but fractures with It has been shown that the dorsal radial reduction and thumb brace is generally > 50% articular involvement require open ligament (DRL) in the thumb base joint reserved for nondisplaced, minimally reduction and internal fixation with screws. contains most mechanoreceptors3 and

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Figure 4: Anatomical reduction of an 4a 4b intra-articular thumb base fracture (a) is mandatory, to reduce the risk of secondary degenerative arthritis and allow a faster return-to-play (RTP). In Bennett fractures with > 50% articular involvement (b), open reduction and internal fixation with screws is preferred.

is the most important ligament in terms the thumb metacarpal to the trapezium 3. Ludwig CA, Mobargha N, Okagbaa J, of dynamic stability in the thumb base. (younger patients, athletes; although Hagert E, Ladd AL. Altered innervation Proprioception training after fracture difficulty with placing their hand on a patterns healing should therefore include specific flat surface after surgery) or basal joint 4. Kadow TR, Fowler JR. Thumb Injuries in training of the opponens pollicis muscle arthroplasty (older, lower-demand patients) Athletes. Hand Clinics. 2017;33(1):161-173. (making a “C” with the thumb and index may be indicated. finger) and the first dorsal interosseus muscle (abduction of the index finger), with the resistance of tension bands. Adding COMPLICATIONS this specific training after fracture healing, • Malunion and subsequent degenerative and in between seasons, especially for arthritis resulting from inadequate goalkeepers, could perhaps be beneficial. articular reduction. Return-to-play (RTP) should be • Pin tract infection (better to shorten the individualized, depending on sports, side of K wires and leave them under the skin). Gustavo Vinagre M.D., Ph.D. injury and position of the athlete. It should • Neuroma of superficial cutaneous Orthopaedic Surgeon and Sports Medicine start in a protective splint or cast not less nerves. Specialist than 2 weeks (once the wound has healed) However, 90% of the treated patients and it can go up to 10 weeks depending – including athletes - can expect a good Flávio Cruz M.D. on the recovery and the type of sport4. The recovery after surgical treatment, with treating physician must balance pressure correct reduction and fixation of the fracture Orthopaedic Surgeon from athletes, parents, coaches, and and after completing the physiotherapy executives to expedite RTP with the long- rehabilitation. Jonny K Andersson M.D., Ph.D. term well-being of the athlete. However, Senior Consultant Hand Surgery one must carefully weigh the added risks involved with surgical intervention and respect biologic and healing time. Aspetar Orthopaedic and Sports Medicine Hospital OUTCOMES References Doha, Qatar The majority of the patients can expect 1. John T. Capo, C. H. Operative Treatment of a good recovery after surgical treatment Thumb Carpometacarpal Joint Fractures. Contact: [email protected] of Bennett or Rolando fractures. Superior Em S. H. Thomas R. Hunt III, Operative results are seen in surgically treated Techniques in Hand, Wrist, and fractures in which there is no residual Surgery. 2011;pp. 228-238. Philadelphia: subluxation of the thumb metacarpal Lippincott Williams & Wilkins. shaft and less than 1 mm of intra-articular 2. Liverneaux PA, Ichihara S, Hendriks S, displacement. It is generally agreed that if Facca S, Bodin F. Fractures and dislocation pain and articular incongruity persist after of the base of the thumb metacarpal. 6 months of observation and physiotherapy Journal of Hand Surgery: European after closed or open surgery, fusion of Volume. 2015;40(1):42-50.

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