Tendon transfers and realignment osteotomies for treatment of stage II posterior tibial tendon dysfunction

Calcaneal Osteotomies in the Treatment of Progressive Collapsing Foot Deformity. What are the Restrictions for the Holy Grail?

The progressive collapsing foot deformity is a complex three-dimensional deformity, including valgus malalignment of the heel. The medial displacement calcaneal osteotomy is an established surgical procedure reliably resulting in an efficient correction of the inframalleolar alignment. However, complications are common, including undercorrection of underlying deformity, progression of hindfoot osteoarthritis and/or deformity, and/or symptomatic hardware.

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Anatomical study of toe flexion by flexor hallucis longus

Because connections exist between the flexor hallucis longus (FHL) and flexor digitorum longus (FDL), the FHL is surmised to exert a flexion action on the lesser toes, but this has not been studied quantitatively. The objectives of this study have thus been to clarify the types of FHL and FDL connections and branching, and to deduce the toe flexion actions of the FHL. One hundred legs from 55 cadavers were used for the study, with FHLs and FDLs harvested from the plantar aspect of the foot, and connections and branches classified. Image-analysis software was then used to analyze cross-sectional areas (CSAs) of each tendon, and the proportion of FHL was calculated in relation to flexor tendons of each toe. Type I (single slip from FHL to FDL tendon) was seen in 86 legs (86%), Type II (crossed connection) in 3 legs (3%), and Type III (single slip from FDL to FHL tendon) or Type IV (no connection between muscles) in 0 legs (0%). In addition, Type V (double slip from FHL to FDL tendon) was seen in 11 legs (11%), representing a new type not recorded in previous classifications. In terms of the various flexor tendons, the proportion of FHL showing tendons to toes 2 and 3 was high, at approximately 50-70%. Consequently, considering the branching type and proportion of CSA, the FHL was conjectured to not only act to flex the hallux, but also play a significant role in the flexion of toes 2 and 3. These results offer useful information for future clarification of the functional roles of tendinous slips from the FHL.

Anatomical study for flexor hallucis longus tendon transfer in treatment of Achilles tendinopathy

PURPOSE

The purpose of the study was to describe the anatomical variations of the connection between the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendons in the knot of Henry in Asians, and quantify the length of FHL tendon graft with different incisions.

METHODS

Sixty-four embalmed feet of 32 cadavers were analyzed anatomically with respect to the individual cross-links in the planta pedis. Single incision technique graft length was measured from the musculotendinous junction of FHL and the point at sustentaculum tali. Double incision technique was measured from musculotendinous junction of FHL and the level of the master knot of Henry. Additionally, minimally invasive incision technique was measured from musculotendinous junction of FHL to the first interphalangeal joint. These three techniques were then combined to determine the total potential tendon graft length obtainable using different approach.

RESULTS

Only two different configurations were found. Type 1, a tendinous slip branched from the FHL to the FDL (62 of 64 feet). Type 2, a slip branched from the FHL to the FDL and another slip from the FDL to FHL (2 of 64). The average length of the FHL graft available from a single incision measured 5.08 cm (range 3.32-10.35, SD = 1.09), double incision technique measured 6.72 cm (range 4.69-12.09, SD = 1.03), and minimally invasive incision measured 17.49 cm (range 13.51-20.52, SD = 1.80). The difference between the lengths obtained from these three techniques was statistically significant (p < 0.001).

CONCLUSION

The absence of no attachment and FDL tendon to the FHL between the two tendons in the foot may be more frequent than previously reported. Only two configurations of the anatomical relationship were found in this study. In over 96 % of the feet, a proximal to distal connection from the FHL to the FDL was found, which might contribute to the residual function of the lesser toes after FDL transfer.

Anatomical variations of the flexor hallucis longus and flexor digitorum longus in the chiasma plantare

BACKGROUND

The flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon are routinely used in reconstructive foot and ankle surgery. The tendons cross in the chiasma plantare and show variable interconnections. This can complicate harvesting of the tendons. Previous anatomical studies were inconclusive and did not reference the connections to surgically relevant landmarks. The purpose of this study was to integrate these conflicting results, introduce a thorough classification system, and analyze the position of the interconnections relative to the surgically relevant bone landmarks.

METHODS

Sixty embalmed feet of 30 cadavers were analyzed anatomically with respect to the individual cross-links in the planta pedis. All feet were photo documented. The interconnections were classified in a modified classification system and distances to surgically relevant anatomic landmarks measured.

RESULTS

A proximal to distal connection from the FHL to the FDL was found in 95% of the feet (types I and III), in 3% there was a proximal to distal connection from the FDL to the FHL (type II) tendon only, and in 30% a crossed connection (type III) was found. The average point of branching of the FHL and FDL tendon was 5.3 and 4.6 cm distal to the medial malleolus, respectively.

CONCLUSION

Our modified classification system accommodated all found variations. In over 90% of the feet, a proximal to distal connection from the FHL to the FDL was found, which might contribute to the residual function of the lesser toes after FDL transfer.

CLINICAL RELEVANCE

The exact knowledge of the anatomy of the crossing of FDL and FHL in the plantar foot is essential to facilitate tendon harvesting, reduce morbidity and explain possible postoperative functional loss.

Flexor digitorum longus transfer and medial displacement calcaneal osteotomy for the treatment of stage II posterior tibial tendon dysfunction: kinematic and functional results of fifty one feet

PURPOSE

Stage II posterior tibial tendon dysfunction (PTTD) can be treated by flexor digitorum longus (FDL) tendon transfer and medial displacement calcaneal osteotomy (MDCO). Numerous authors have studied the clinical and radiographic results of this procedure. However, little is known about the kinematic changes. Therefore, the purpose of this study was to assess plantar-pressure distribution in these patients.

METHODS

Seventy-three patients with PTTD stage II underwent FDL tendon transfer and MDCO. Plantar pressure distribution and American Orthopaedic Foot and Ankle Society (AOFAS) score were assessed 48 months after surgery. Pedobarographic parameters included lateral and medial force index of the gait line, peak pressure (PP), maximum force (MF), contact area (CA), contact time (CT) and force-time integral (FTI).

RESULTS

In the lesser-toe region, PP, MF, CT, FTI and CA were reduced and MF in the forefoot region was increased. These changes were statistically significant. We found statistically significant correlations between AOFAS score and loading parameters of the medial midfoot.

CONCLUSIONS

Study results reveal that FDL tendon transfer and MDCO leads to impaired function of the lesser toes during the stance phase. However, there seems to be a compensating increased load in the forefoot region.

Young's procedure for the treatment of valgus flatfoot deformity caused by a posterior tibial tendon dysfunction, stage II

Young’s procedure contains an action mechanism that works better than other techniques on the pathophysiology of FFD. It respects the anatomy and biomechanics of the foot to reach the necessary muscular balance. The benefits of this technique include that the ATT is not detached, so its function mechanism is still active; the new trajectory of the ATT provides a powerful sling function at the level of the navicular; and the horizontal trajectory of the ATT and the osteoperiosteal flaps constitute a powerful inner capsular–tendinous–ligamentous support. What is more, an insufficiency of the ATT is created, which results in a predominance of the peroneus lateral longus, that descends and prones the forefoot. Additional procedures, such as medial displacement calcaneal osteotomy, should be considered to correct the entire deformity. The combination of these techniques do not sacrifice the joint mobility.

[Injuries and dysfunction of the posterior tibial tendon]

The function of the posterior tibial (PT) tendon is to stabilize the hindfoot against valgus and eversion forces. It functions as the primary invertor of the foot and assists the Achilles tendon in plantar flexion. The PT tendon is a stance phase muscle, firing from heel strike to shortly after heel lift-off. It decelerates subtalar joint pronation after heel contact. It functions as a powerful subtalar joint supinator and as a support of the medial longitudinal arch. The action of the tendon travels to the transverse tarsal joints, locking them and allowing the gastrocnemius to support heel rise. Acute injuries of the PT tendon are rare and mostly affect the active middle-aged patient or they are the result of complex injuries to the ankle joint complex. Dysfunction of the PT tendon following degeneration and rupture, in contrast, has shown an increasing incidence in recent years. To which extent changed lifestyle, advancing age, comorbidities, and obesity play a role has not yet been clarified in detail. Dysfunction of the PT tendon results in progressive destabilization of the hind- and midfoot. Clinically, the ongoing deformation of the foot can be classified into four stages: in stage 1, the deformity is distinct and fully correctable; in stage II, the deformity is obvious, but still correctable; in stage III, the deformity has become stiff; and in stage IV, the ankle joint is also involved in the deformity. Treatment modalities depend on stage: while conservative measures may work in stage I, surgical treatment is mandatory for the later stages. Reconstructive surgery is advised in stage II, whereas in stage III and IV correcting and stabilizing arthrodeses are advised. A promising treatment option for stage IV may be adding an ankle prosthesis to a triple arthrodesis, as long as the remaining competence of the deltoid ligament is sufficient. An appropriate treatment is mandatory to avoid further destabilization and deformation of the foot. Failures of treatment result mostly from underestimation of the problem or insufficient treatment of existing instability and deformity.

Treatment of posterior tibial tendon dysfunction without flexor digitorum tendon transfer: a retrospective study of 34 patients

A retrospective study of patients who underwent gastrocnemius recession, double calcaneal osteotomy (Evans osteotomy and percutaneous calcaneal displacement osteotomy), and medial column fusion for the treatment of posterior tibial tendon dysfunction was conducted. The senior author performed the procedures between November 2002 and January 2009 on 34 patients who displayed at least Johnson and Strom stage II deformity and had undergone 12 months of failed conservative treatment. The coauthors evaluated the patients' radiographs before and after the operation. At a mean of 14 (range 3 to 44) months after surgery, radiographic measurements demonstrated statistically significant changes in the structural alignment of the feet. Based on our experience with these patients, we believe that a double calcaneal osteotomy combined with a gastrocnemius recession and stabilization of the medial column for the treatment of posterior tibial tendon dysfunction provides satisfactory correction, stability, and realignment of the foot. Furthermore, we feel that the use of flexor digitorum longus transfer, as well as triple arthrodesis, can be avoided without compromising the outcome when surgically treating posterior tibial tendon dysfunction.