Middle Phalangeal Distal Condylar Fracture Remodelling in Children: A Case Report

INTRODUCTION

Finger phalangeal fractures are the second most commonly encountered injuries, especially among elementary school children (14.4%), after distal radius fractures (40.3%) (9). This fracture is characterized by apex volar angulation at the fracture site due to flexor digitorum superficialis tendon pull, especially if the injury is at the midphalangeal level. The diagnosis is made by obtaining lateral radiographs and evaluating the displacement of the fragments. Occasionally this fracture is inadequately reduced in the emergency room and referred late to the hand surgeons. With a fracture at this level, there is always the risk of avascular necrosis of the small distal fragment, with open reduction and fixation techniques; therefore the treatment options should be thoroughly analyzed in terms of morbidity (12, 3). Recently we encountered an alternative procedure in which we utilized the remodelled bone and shaped it with osteotomies and plaster splinting in the appropriate position. Remodelling has been reported in 3 displaced neck fractures of the middle phalanx and in 2 of the proximal phalanx (4, 6, 7) . Our case is unique in that although the fracture is closer to the distal end of middle phalanx , in the sagittal plane, considerable remodelling was noted with no epiphysiolysis on radiography. The result was sufficient distal interphalangeal (DIP) joint motion and function and symmetrical growth of the hands.

CASE REPORT

A 9-year-old girl sustained an injury to her left middle finger with a piece of metal 2 months before she presented to our clinic. In the acute trauma phase she only applied ice to her hand and did not consult a medical practitioner about the pain and swelling on her finger. Two months after the injury she was referred to our clinic with a palpable mass on the volar side of middle phalanx (Fig. 1). On lateral radiographic view, an apex volar angulation measuring approximately 45 degrees of vertically splitting midphalangeal fracture was noted (Fig. 2). Bone remodelling was also seen dorsally extending from the midphalanx to the level of the DIP joint. The DIP joint showed no active or passive movements, but the dorsal surface of the middle finger midphalanx showed unity upon palpation. During the operation the middle phalanx was reached through a radial midlateral incision. The newly formed, remodelled bone seemed to be in unity with the DIP joint. Maintaining the phalangeal stability, the apex volarly angulated distal fragment of the middle phalanx was osteotomized. Immediately after removing the volar segment, passive range of motion of the phalanx was improved, and the DIP joint was stabilized. The improvement in flexion at the DIP joint was approximately 40-50 degrees in the middle phalanx. In order to achieve full restoration of active and passive motion, a plantar splint was applied for 3 weeks, followed by active motion exercises. In the postoperative 18 months a control radiologic view was obtained. Normal phalangeal alignment with minimal (5 degrees) dorsal angulation was noted, which was quite acceptable. Symmetrical growth of both hands was also seen on radiography. To date, 2 years later, the patient has undergone regular follow-up examinations, and recent radiographic views are shown with anatomic alignment of the phalanges and joints (Fig. 3 and 4).

DISCUSSION

Children are exposed to trauma more frequently than adults, due to lack of defense mechanisms or the failure of their parents to supervise them adequately. Phalangeal fractures usually heal without sequelae with early detection and appropriate reduction (5). In our case, which was a late presentation with significant bone remodelling, the volar fragment of the fracture was resected because the remodelled bone seemed to form a uniform callus that extended to the DIP joint, which helped significantly with the stability of the finger. After the planned osteotomies no K-wire or plate-screw fixation was utilized, so as not to injure the epiphysis of the middle phalanx. We believe that in selected cases, especially in injured children during the rapid growth ages, our treatment protocol will be sufficient without disturbing the overall hand growth.

Fractures in children show epidemiological characteristics which are different from adults (2, 11). In fractures among children, a strong male predominance is noted. Phalangeal distal condylar fractures are commonly encountered in children. While achieving anatomic alignment in acute phalangeal fractures remains the main goal in treatment, treating late presenting pediatric phalangeal malunions non-operatively is advocated based on findings (8), thus avoiding stressful complications of difficult procedures such as avascular necrosis or epiphyseal plate injury. In cases like the one outlined here we are convinced that nonsurgical treatment might be acceptable when malrotation is not present. Remodelling is slow, and some children - and their families - are not prepared for the restriction of motion or deformity that comes with waiting 1 to 2 years for remodelling. In addition, not all fractures remodel, so a late osteotomy may be required. Phalangeal neck or distal condylar fractures are classified into three types according to Al-Qattan (1). Type 1 fractures are nondisplaced, and treatment with splinting alone results in an excellent outcome in almost all cases. A minimally displaced fracture should be considered as a Type 2. Type 2 and 3 fractures are displaced, with bone-to-bone contact between the proximal and distal fragments in Type 2, but not in Type 3 fractures. It is often assumed that these fractures, like most fractures in children, will sort themselves out with remodelling. However, the phalanges only have an epiphysis at their proximal end, and thus there is little potential for remodelling after this fracture. Persistent dorsal displacement of the distal fragment usually leads to malunion with new bone formation on the palmar side of the proximal fragment. This new bone obliterates the subcondylar fossa and limits flexion of the interphalangeal joint. When this occurs at the PIP or DIP joint, the disability is usually significant, and removal of the bony block is the necessary (10). There has been a single case report of complete remodelling of a displaced phalangeal neck fracture in a 7-year-old boy (7).

Our case is unique in that although little remodelling potential exists at the distal ends of the phalanges, remote from the physis, a strongly formed remodelled bone in alignment with DIP joint was noted on exploration. As reviewed by Ogden et al previously, the possible mechanism behind this remodelling distant from a physis may be because of deposition of bone under an intact periosteum (8). In our case the dorsal fragment or local forces in the plane of joint motion stimulated bone growth. As a result, significant reconstruction can still be offered, because it enables the child to function sooner, but with considerable risks mentioned earlier. However, in selected cases (like ours), sparing the remodelled bone and plaster splinting may also succeed since it eliminates malalignments, achieves full joint motion, and initiates the growth potential of the hand – if the family and the child are willing to be patient. It should be noted that this technique should be reserved for patients with incompletely healed fractures.

Address for correspondence:

Kamuran Zeynep Sevim, M.D., Plastic and Reconstructive Surgeon Acibadem Koftuncuoglu caddesi

IsBankasi bloklari A6 BlokD33

Acibadem Kadikoy Istanbul 34718

Turkey

E-mail: kzeynep.sevim@gmail.com