Adult flatfoot deformity is a progressive condition that causes flattening or collapse of the arch of the foot and is characterized by pain and difficulty managing daily activities. Although damage to the posterior tibial tendon is the most common cause, other contributing factors include arthritis, injury, and Charcot foot. Among patients who have a flexible—as compared to rigid—arch collapse, surgery can often help improve pain and walking ability.

Two commonly performed adult flatfoot procedures include subtalar arthroereisis (SA) and lateral column lengthening (LCL). During the SA procedure, an implant is placed below the talus to stabilize the subtalar joint by limiting excessive pronation and preserving varus range of motion. LCL allows surgeons to create a higher arch by realigning the calcaneus.

To evaluate whether one procedure might offer better repair than the other, Lee Bing Howe, MD, Yong Loo Lin School of Medicine, Singapore, described outcomes from a study that compared clinical and radiographic outcomes of the two surgeries. Eighteen consecutive patients (11 men, 7 women) with adult stage II flexible flatfoot deformity were randomized to surgical treatment with either LCL (n = 9) or SA (n = 9) performed by a senior surgeon. All patients also underwent a concomitant endoscopic gastrocnemius recession procedure, a medializing calcaneal osteotomy, and a modified Kidner procedure. LCL procedures were performed using an 8-mm wedge plate; SA was performed using a size 10-mm implant. The average age at the time of surgery was comparable in the LCL (30.8 years) and SA (31.7 years) groups.

Clinical outcomes were measured using pre- and postoperative American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale and the SF-36 Health Survey Update (SF-36) scores at 3, 6, 12, and 18 months. Radiographic measurements were assessed using 10 parameters on the anteroposterior (AP) and lateral weight-bearing radiographs at 6 and 18 months. The minimum length of follow-up was 18 months.

At the time of the final follow-up, only patients in the SA group showed significant improvement in SF-36 scores (P < .05). Postoperative AOFAS scores showed significant improvements in both groups (LCL group, P = .038; SA group, P = .008).

At 18 months, both groups showed significant improvements (P < .05) in 5 of the 10 radiologic parameters measured: (1) talus–first metatarsal angle (AP), (2) talus–first metatarsal angle (lateral), (3) calcaneal pitch angle (lateral), (4) talonavicular uncoverage angle (AP), and (5) and medial column height (lateral).

According to Prof Howe, these data suggest that in adults with flexible flatfoot deformity, the SA procedure is similarly effective for the LCL as measured clinically and radiographically. However, he cautioned that it will be important to monitor how long the correction ultimately persists before the overall effectiveness of the procedure can be determined.