Results of treatment of stage II posterior tibial tendon rupture with flexor digitorum longus tendon transfer and calcaneal osteotomy

In a retrospective study, we reviewed our results of treatment of stage II posterior tibial tendon rupture in 129 patients for whom surgery was performed between 1990 and 1997. During this period of time, 148 patients were treated with surgery following failure of nonsurgical methods of treatment. The 129 patients (117 females, 12 males) with an average age of 53 years (range, 34–75 years) had been symptomatic for an average of 2.8 years (range, 0.5–7 years). The indication for surgery was the presence of foot pain, which was refractory to shoe modifications, orthoses, and brace support. All patients had a painful flexible flatfoot without a fixed forefoot supination deformity. The surgery performed included a medial translational osteotomy of the calcaneus and transfer of the flexor digitorum longus tendon into the navicular. There were additional surgeries performed in 49 patients including repair of a tear of the spring ligament, talonavicular capsule or deltoid ligament (45), lengthening of the Achilles tendon (26), correction of hallux valgus deformity (5), and arthrodesis of the first tarsometatarsal joint (4). All patients were examined, radiographs obtained, and isokinetic evaluation of both feet and lower limbs performed with the KinCom apparatus at a mean of 4.6 years following surgery (range, 3–8 years). The AOFAS hindfoot scale was used to evaluate each patient, although, due to the time elapsed from the initiation of treatment, preoperative AOFAS scores were not retrospectively determined. The mean AOFAS score at the time of the follow-up examination was 79 points (range, 54–93). There were 7 significant complications in 6 patients including: significant progressive hindfoot valgus deformity in 1 patient treated with a triple arthrodesis; overcorrection of the hindfoot in 2 patients necessitating revision with a lateral closing wedge calcaneus osteotomy; 3 patients with symptomatic sural neuritis, and 1 patient with weakness of the gastrocnemius resulting from overlengthening of the Achilles tendon. Isokinetic inversion and plantarflexion power and strength were compared with the contralateral limb for 121 patients, and were noted to be symmetric in 95, mildly weak in 18, and moderately weak in 8. Motion of the subtalar joint was normal in 44%, slightly decreased in 51%, and moderately decreased in 5% of patients. Anteroposterior and lateral radiographs were evaluated for the talonavicular coverage angle, talus-first metatarsal angle, talocalcaneal angle, and the height of the medial cuneiform to the floor. For 4 of these 5 parameters evaluated, the correction obtained was statistically significant (p < 0.05). Of the patients examined, 123 were entirely satisfied, 4 partially satisfied, and 2 were dissatisfied with the outcome of the procedure. Most patients experienced pain relief (97%), an improvement of function (94%), noted an improvement in the arch of the foot (87%), and were able to wear shoes comfortably without resorting to shoe modifications or orthotic arch support (84%). In conclusion, the surgical correction of stage II posterior tibial tendon rupture with medial translational calcaneus osteotomy and flexor digitorum longus tendon transfer to the navicular yielded excellent results with minimal complications, and a high patient satisfaction rate.