An Overview Of Surgical Treatments For Stage II Tibialis Posterior Tendon Dysfunction

Regardless of the etiology of the deformity, the three principles for flexible flatfoot deformity surgical correction include:

• removal of any deforming force of the leg onto the foot;
• perpendicular alignment of the hindfoot to the ground; and
• a parallel relationship of the forefoot to the rearfoot. This applies to pediatric flexible flatfoot, adult flexible flatfoot and stage II tibialis posterior tendon dysfunction

The treatment of stage II tibialis posterior tendon dysfunction has evolved over the years to a well-documented group of procedures.

Posterior muscle group lengthening (gastrocnemius recession or tendo-Achilles lengthening) removes the deforming force from the leg onto the foot. The procedure is based on the type of equinus present. If the surgeon ignores equinus, the tight gastroc-soleus complex produces a plantarflexory force at the naviculocuneiform joint pronating the foot. This deforming force will eventually devastate any correction that one obtains surgically.

Various authors have described the hindfoot correction, which consists of either a medial calcaneal displacement osteotomy or a double calcaneal osteotomy with the additional lateral column lengthening. A more distal calcaneal osteotomy results in more hindfoot correction. When performing the osteotomy, one should not enter the subtalar joint, using an angled osteotomy parallel to the peroneal tendon course. Medial translation of the calcaneus perpendicular to the weightbearing surface and plantar translation of the posterior fragment will result in an increase in the calcaneal inclination angle and arch restoration.

When one performs a tendo-Achilles lengthening as opposed to a gastrocnemius recession, the plantar translation of the posterior fragment is much easier. One should take this factor into consideration in equinus reduction planning. When it comes to severe deformities, the double osteotomy approach may be required with the addition of an Evans lateral calcaneal osteotomy.

The flexor digitorum longus tendon transfer to the posterior tibial tendon is the final commonly described procedure in the surgical reduction of stage II tibialis posterior tendon dysfunction. This procedure provides active supinatory force to the foot and possible medial column stability. I typically weave the flexor digitorum longus tendon into the posterior tibial tendon and then either pass the flexor digitorum longus through a drill hole in the navicular tuberosity, or suture the distal end into the advanced posterior tibial tendon insertion. Then I will repair the flexor retinaculum and tendon sheath to prevent subluxation of the tendon complex at the medial malleolus.

Emphasizing The Value Of The First Metatarsocuneiform Arthrodesis

The fourth procedure and the procedure frequently not mentioned in the literature for Stage II tibialis posterior tendon dysfunction surgical reconstruction is the first metatarsocuneiform arthrodesis. This procedure is vital for consistent results but often goes ignored in the literature on this deformity.

This procedure allows podiatric surgeons to put the forefoot into a parallel position to the rearfoot, correcting the forefoot varus deformity. This procedure can be technically demanding to correct the forefoot varus deformity adequately but it is of the utmost importance. If the patient has a remaining rigid forefoot varus deformity, the lack of available subtalar joint eversion can cause overloading of the lateral column and subsequent pain.

In Conclusion

The surgical correction of Stage II tibialis posterior tendon dysfunction includes several well-researched techniques but little has been written about the role of the first metatarsocuneiform arthrodesis. The principles of flexible flatfoot reconstruction mandate that one correct the deforming force of the leg, place the hindfoot perpendicular to the weightbearing surface and have the forefoot parallel to the rearfoot. One can most fully accomplish this last principle with the first metatarsocuneiform arthrodesis.

References
1. Chan JY, Williams BR, Nair P, Young E, Sofka C, Deland JT, Ellis SJ. The contribution of medializing calcaneal osteotomy on hindfoot alignment in the reconstruction of the stage II adult acquired flatfoot deformity. Foot Ankle Int. 2013;34(2):159-66.
2. Niki H, Hirano T, Okada H, Beppu M. Outcome of medial displacement calcaneal osteotomy for correction of adult-acquired flatfoot. Foot Ankle Int. 2012;33(11):940-6.
3. Brilhault J, Noël V. PTT functional recovery in early stage II PTTD after tendon balancing and calcaneal lengthening osteotomy. Foot Ankle Int. 2012;33(10):813-8.
4. Kou JX, Balasubramaniam M, Kippe M, Fortin PT. Functional results of posterior tibial tendon reconstruction, calcaneal osteotomy, and gastrocnemius recession. Foot Ankle Int. 2012;33(7):602-11.
5. Myerson MS, Badekas A, Schon LC. Treatment of stage II posterior tibial tendon deficiency with flexor digitorum longus tendon transfer and calcaneal osteotomy. Foot Ankle Int. 2004;25(7):445-50.
6. Haeseker GA, Mureau MA, Faber FW. Lateral column lengthening for acquired adult flatfoot deformity caused by posterior tibial tendon dysfunction stage II: a retrospective comparison of calcaneus osteotomy with calcaneocuboid distraction arthrodesis. J Foot Ankle Surg. 2010;49(4):380-4.
7. Sizensky JA, Marks RM. Medial-sided bony procedures: why, what, and how? Foot Ankle Clin. 2003;8(3):539-62.