Tendon Balancing in Pedal Amputations

Preserving Functional Capacity as Opposed to Tissue Preservation in the Diabetic Patient

“…Because of loss of the insertions of some of the extrinsic pedal musculature and the loss of the metatarsal head weight-bearing surface, TMA is known to be associated with imbalance of the residual foot, and this can lead to complications related to cutaneous compromise, as well as difficulties with bracing and shoe fit. [40][41][42][43] The concept of balancing TMAs through various soft-tissue tendon transfers or osseous realignment such that the ankle has full dorsiflexion (ie, no equinus) and the forefoot contacts the weight-bearing surface as a collective unit (ie, no varus) has recently become popularized. [41][42][43][44][45][46] It stands to reason that after addressing reversible causes of failure to heal mentioned above, if the residual foot following TMA is balanced, then function should be improved and the likelihood of recurrent ulceration should be reduced.…”

“…[40][41][42][43] The concept of balancing TMAs through various soft-tissue tendon transfers or osseous realignment such that the ankle has full dorsiflexion (ie, no equinus) and the forefoot contacts the weight-bearing surface as a collective unit (ie, no varus) has recently become popularized. [41][42][43][44][45][46] It stands to reason that after addressing reversible causes of failure to heal mentioned above, if the residual foot following TMA is balanced, then function should be improved and the likelihood of recurrent ulceration should be reduced. The authors believe this is demonstrated by our results since none of the patients who underwent balancing have ulcerated or required revision surgery, whereas 3 patients with varus forefoot deformity who could not undergo balancing due to limited regional perfusion readily ulcerated at the plantar-lateral residual forefoot and required higherlevel amputation.…”

Soft Tissue Balancing After Partial Foot Amputations

“…It can be anchored by a trephine bone plug, a biotenodesis screw, the buttonhole technique, or tunnels. 25 Potential complications are similar but this often involves the introduction of a foreign material, because the most common type of fixation today is the biotenodesis screw. Often in the complex patient population, difficulty is found with the patient's bone stock and obtaining appropriate fixation of the tendon.…”

“…This has been described as a loss of a rigid beam effect, causing increased plantar stump pressure, exaggerated varus, and subtalar joint imbalance. 24,25 To address the deformities that are present after a TMA, several tendon balancing procedures have been described. The gastrocnemius-soleus complex is the most important structure to address and also the most frequently addressed consistently by foot and ankle surgeons by lengthening the tendon.…”

“…44 The tendon is then fixated using a biotenodesis screw, buttonhole technique, or tendon anchors. 25 Appropriate tension must be achieved prior to final fixation. This technique is challenging because patients with partial foot amputations often have poor soft tissue envelopes, poor bone quality, poor vascular supply, and already weakened tendons.…”