The effects of ankle joint replacement on gait

Abstract

Patients with ankle arthritis experience significant disability. In patient-centered surveys, the mental and physical disability is equivalent to that associated with end-stage hip arthritis (Glazebrook et al. Bone Joint Surg Am 90(3):499-505, 2008). End-stage ankle arthritis has a number of features differentiating it from hip and knee arthritis. Unlike the primary osteoarthritis of the hip and knee, 70% of ankle arthritis is post-traumatic in nature (Saltzman et al. Iowa Orthop J 25:44-46, 2005). Given the high degree of success seen with total hip arthroplasty (THA) and total knee arthroplasty (TKA), the first generation of total ankle arthroplasty (TAA) was introduced in the 1970s. Unfortunately, early TAA did not have the same success as other arthroplasty procedures, and the procedure was largely abandoned in favor of return to ankle arthrodesis (Bolton- Maggs et al. J Bone Joint Surg Br 67:785-790, 1985, Dini and Bassett Clin Orthop 146:228-230, 1980, Kitaoka and Patzer J Bone Joint Surg Am 76:974-979, 1994, Stauffer and Seagal Clin Orthop 160:217-221, 1981, Kofoed and Sorensen J Bone Joint Surg 80-B:328-332, 1998, Demottaz et al. J Bone Joint Surg Am 61 (7):976-988, 1979). While arthrodesis was more reliable with fewer complications than arthroplasty, arthrodesis has the limitation of loss of ankle motion, especially in cases in which there is severe arthritis but moderate residual joint motion. Complications of arthrodesis include nonunion and malunion, and there are reports of arthritis at adjacent joints and residual abnormalities of gait (Beischer et al. Foot Ankle Int 20:545-553, 1999, Buchner and Sabo Clin Orthop Relat Res 406:155-164, 2003, Buck et al. J Bone Joint Surg 69-A:1052-1062, 1987, Coester et al. J Bone Joint Surg 83-A:219-228, 2001, Fuchs et al. J Bone Joint Surg 85-B:994-998, 2003). The complications associated with ankle arthrodesis, coupled with the desire to more normally replicate ankle biomechanics, have led to renewed interest in TAA in recent years, with encouraging reports of early- and mid-term results and improved survivorship compared to first-generation series. Even though TAA does not yet have the longevity of THA and TKA, there are many early and intermediate-term reports of high levels of patient satisfaction, pain relief and patient function, and variable survivorship at 80-95%, depending on the length of follow-up (Haddad et al. J Bone Joint Surg Am 89:1899-1905, 2007a, Gougoulias et al. Clin Orthop 468:199-208, 2010). One of the postulated benefits of TAA is preservation of tibiotalar motion. A number of studies have demonstrated improvements in gait following TAA. While TAA does not restore normal gait, patients have improvements in nearly all parameters of gait with many approaching normal controls (Valderrabano et al. Clin Biomech 22:894-904, 2007, Doets et al. Foot Ankle Int 28(3):313-322, 2007, Singer et al. J Bone Joint Surg Am 95(e191):1-10, 2013, Flavin et al. Foot Ankle Int 34(1):1340-1348, 2013). More importantly, when gait studies have compared TAAwith preoperative function, TAA offers a significant improvement (Singer et al. J Bone Joint Surg Am 95(e191):1-10, 2013, Flavin et al. Foot Ankle Int 34(1):1340-1348, 2013, Queen et al. J Bone Joint Surg Am 96:987-993, 2014a, Piriou et al. Foot Ankle Int 29(1):3-9, Brodsky et al. J Bone Joint Surg Am 93:1890-1896, 2011, Queen et al. Foot Ankle Int 33(7):535-542, 2012, Queen et al. Clin Biomech 29:418-422, 2014b).