Phalangeal fractures : current treatments, complications and innovations

Abstract: Phalangeal fractures are common and most of them heal well without surgical intervention. However, the comminuted and displaced unstable fractures sometimes require surgery. There are many different surgical options available such as K-wires, screws of different kinds, plates and screws, and external fixations. The outcome varies widely in the literature when it comes to results and complications caused by the different osteosynthesis methods. The aims of this thesis are to: 1. Analyze the practice in our department regarding surgery of phalangeal finger fractures including choice of surgical method, complications and reoperations. 2. Investigate the properties of and participate in the development of a new method of fracture fixation- an adhesive suited for bone repair. 3. Examine thepotential benefit of adhesion barriers in fracture treatment. In Paper I patient files of all patients treated surgically for a closed intraarticular fracture of the base or middle phalanx of the fingers during the period from 2010- 2014 at the Department of Hand Surgery at Södersjukhuset were examined retrospectively. Fracture type, operation method and reoperations were analyzed. Results showed a higher incidence of reoperations due to adhesions and resulting finger stiffness in patients operated with a plate than when K-wires or screws only were used. When adjusting for fracture complexity, the results were no longer significant indicating that a more complex fracture in itself also causes more adhesions and finger stiffness and leads to more reoperations than the less complicated ones. In Paper II, a thiol-ene composite, which is a new material being investigated for bone repair, was tested biomechanically and biologically in a rat femur fracture model. The composite shows good stability both ex vivo in a fatigue model, and after five weeks in vivo. There were no signs of reduced bone healing in presence of the new material, no signs of inflammation, and it had maintained 60% of its adhesion strength to bone after 5 weeks in vivo. In Paper III, the effects of the adhesion barrier Dynavisc® was evaluated in a pilot study of 10 patients as a first step of a planned randomized controlled trial. The adhesion barrier was applied during surgery after fixation of fractures or osteotomies of extraarticular base phalanges with plates and screws. Finger total active motion (TAM) was evaluated after three months and one year and compared to the TAM of the contralateral finger. Only two patients reached the hypothesized result of a difference of less than 20 degrees of TAM to the contralateral finger. Paper IV is a study of a further development of the thiol-ene composite studied in Paper II, now used as an adhesion barrier called DendroPrime. 12 rabbits were operated on the second toe of the hind paws. A plate was attached to the plantar side of the base phalanx with two screws, after scratching the periosteum inducing a trauma to the bone. On one side the plate was coated with DendroPrime, on the other paw it was left bare. After seven weeks the mobility of the toe was examined in a biomechanical testing device by pulling the tendons with forces from 0 N to 5 N. There was significantly better mobility in toes treated with DendroPrime than in toes with a bare plate at forces of 1 N, 3 N, 4 N and 5 N. The results indicate a potential benefit of this material to reduce complications related to adhesions after fracture surgery.