Randomized Trial Comparing Suture Button with Single Syndesmotic Screw for Syndesmosis Injury

SLR - March 2018 - Rona W. Law

Reference: Andersen MR, Frihagen F, Hellund JC, Madsen JE, Figved W. Randomized Trial Comparing Suture Button with Single Syndesmotic Screw for Syndesmosis Injury. J Bone Joint Surg Am. 2018 Jan 3;100(1):2–12

Scientific Literature Review

Podiatric Relevance: Ankle fractures with injury to the syndesmosis require operative treatment to stabilize load transmission through the talocural joint. Traditionally, the syndesmotic screw has been the treatment of choice for stabilizing syndesmotic injuries. More recently, the dynamic suture button (SB)  has been used as an alternative treatment method. This technology allows greater tibiofibular rotational motion while resisting diastasis. This study compared clinical and radiographic results after stabilization of an acute injured syndesmosis with SB with the results after use of one 4.5 mm quadricortical syndesmotic screw (SS). 

Methods: This is a Level I prospective, randomized controlled trial of 97 patients with an acute traumatic OTA/AO Type 44C ankle fracture. Patients were randomized and operatively treated with either SB (48 patients) or SS (49 patients) from January 2011 to March 2013 at two hospitals. Primary outcome measure was the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale. Secondary outcome measures included the Olerud-Molander Ankle (OMA) score, visual analog scale (VAS) and EuroQol-5D (EQ-5D index and VAS). Postoperative computed tomography (CT) scans of both ankles were obtained at two weeks and one and two years.

Results: The SB group had higher median AOFAS scores than the SS group at all follow-up intervals. The median OMA score was higher in the SB group from six months onward. The EQ-5D Index and EQ-5D VAS scores showed a better health state in the SB group at six months and two years, and six weeks and six months, respectively. At two years, talar osteophytes were 3.4 times more frequent in the SS group than in the SB group. CT scans revealed the development of tibiofibular synostosis and ankle osteoarthritis with similar rates in both SB group and SS group. At one year, the tibiofibular distances were found to be greater in the SS group, anteriorly, centrally and posteriorly with statistical significance (P<0.05). The SS group had more frequent occurrences of increased tibiofibular distance of ≥ 2 mm between the injured and uninjured ankles at two years. Both SS and SB group had similar reoperation rates.

Conclusions: This study is the only randomized controlled trial comparing SB and SS with CT scans used to assess syndesmotic reduction. The use of an SB for the treatment of syndesmotic injuries resulted in higher AOFAS and OMA scores and better radiographic outcomes than the use of one quadricortical SS. Literature has generally reported higher rates of reoperation for SS, which typically involves screw removal with possible revision secondary to local discomfort or screw breakage and subsequent increased syndesmotic diastasis. SB may allow for more motion and better self-centering of the syndesmosis, and therefore, anatomic reduction may be achieved more easily. Limitations included that SS had more patients with a concomitant posterior malleolar fracture and that osteoporosis in both groups on treatment results was not addressed. Future studies to identify the functional and radiographic outcomes associated with the use of two screws as well as the strategy of leaving screw implants in place should be investigated.