Tibialis Posterior Rupture: FDL Transfer


- PreOp Planning:  
    - tendon transfer is chiefly indicated for stage II tenosynovitis;
    - subtalar joint must demonstrate nearly a full range of inversion;
    - early synovectomy of the tendon sheath not only relieves discomfort but will possibly delay or prevent 
           attenuation or rupture;
    - in presence of correctable hyperpronation, transfer of FDL  tendon to distal posterior tibial tendon stump 
           is considered;
    - if subtalar joint cannot be brought into nearly full inversion because of long-standing deformity, then tendon transfer is contra-indicated;
           - in this case consider subtalar arthrodesis;
    - sping ligament:
           - as pointed out by Gazdag and Cracchiolo (1997), 18 out of 22 posterior tib ruptures had injury to the sping ligament;
           - this ligament courses from the sustentaculum tali to the plantar surface of the navicular, and helps support the head of the talus;
            - ref: Rupture of PTT. Evaluation of injury of spring ligament and clinical assessment of tendon transfer and ligament repair.

- Surgical Technique:
    - position bump under contralateral hip;
    - begin incision 10 cm proximal to meidal malleolus, continue distally to about 1 cm posterior to medial border of tibia, & end incision 
           just distal to the medial aspect of navicular tuberosity;
    - deep fascia is incised, with care to preserve a portion of flexor retinaculum, and the TP is exposed, lying close to posterior margin 
           of the tibia;
    - exposure, inspection, and debridement of tibialis posterior:
           - "white sign"
                  - posterior tib will be visible beneath the flexor retinaculum;
                  - abnormally whitened appearance indicates more distal tear;
           - the tendon sheath should be opened in its entirity;
           - if tendon is of normal length, the tendon debridement, tenosynovectomy and sheath resection are performed;
           - if tendon is elongated or appears pathologic, then FDL transfer is required;
                  - most tendons will not have complete rupture, but rather, will have thickening and scarring and often a longitudinal tear 
                         will be present;
                  - complete ruptures tend to occur just distal to medial malleolus;
           - PT tendon is transected leaving a 3 cm stump of tendon attach to the navicular;
                  - this tendon stump may be necessary to repair the spring ligament;  
           - case example: this patient had a degenerative longitudinal rent in the posterior tibialias tendon;
    - spring ligament inspection:
            - at this point in the case, the sping ligament is inspected;
            - the superomedial portion of the spring ligament extends from the sustentaculum tali to the navicular;
            - look for ligament laxity, longitudinal tears, or complete rupture;
            - if the ligament cannot be repaired then use the stump of the PT tendon to augment the reconstruction;
            - also consider spliting distal posterior tibial segment and achoring half to medial malleolus & other to sustentaculum;
            - references:
                   - Spring Ligament Reconstruction Using the Autogenous Flexor Hallucis Longus Tendon
                   - Anatomic study of medial side of ankle base on joint capsule: alternative description of the deltoid and spring ligament.
                   - Spring Ligament Instability.
                   - Rupture of PTT. Evaluation of Injury of Spring Lig and Clinical Assessment of Tendon Trasfer and Ligament Repair.
                   - Adult acquired flatfoot deformity at the talonavicular joint: reconstruction of the spring ligament in an in vitro model.
                   - Combined Spring and Deltoid Ligament Repair in Adult-Acquired Flatfoot
                   - What to Do with the Spring Ligament.
                   - Anatomical reconstruction of the spring ligament complex: "internal brace" augmentation.



    - FDL tendon harvest
            - the FDL sheath is opened distally and is cut distally and is opposed to undersurface of the navicular;
            - the FDL tendon sheath is found directly behind the PT tendon sheath;
            - it is transected as distally as possible (usually as it crosses the FHL tendon);
                    - usually the biggest pitfall of the case is not obtaining enough FDL length;
            - it is not necessary to tenodese the distal FDL tendon stump to the FHL since there are distal interconnections;
            - ref: Risk of Neurovascular Injuries in Flexor Hallucis Longus Tendon Transfers: An Anatomic Cadaver Study 

    - if the PT's sheath is scarred then it is important to leave intact the FDL tendon sheath behind the medial malleolus;
    - alternatively, if the posterior tib sheath is clean, the FDL tendon can be retracted and passed into the PT sheath;
    - drill hole is passed thru navicular tuberosity from dorsal to plantar direction;
    - FDL is brought thru the drill hole from inferior to superior;
    - medial calcaneal sliding osteotomy:
           - ref: The role of osteotomies in the treatment of posterior tibial tendon disorders.
                        Manoli A II, Beals TC, Pomeroy GC. Foot and Ankle Clin.1997;2:309-317.

             
    - optimizing tension of the graft:
           - place anke into slight varus & eqinus, and forefoot adduction;
           - the ankle should not be over tightened;
           - if the navicular is laterally subluxed on the talus, consider shortening the medial capsule prior to tendon suturing;
           - then put tension on FDL tendon and anchor down the suture;
           - if possible, suture the FDL tendon back onto itself, otherwise anchor the FDL to the stump of the PT tendon;

             

    - misc: consider achilles tendon lengthening if necessary;
    - wound closure:
           - if the tibialis posterior muscle belly appears healthy w/ normal 1 cm excursion, then the tendon can be sutured to the FDL 
                  at the level of the meidal malleolus;
           - close the tibialis posterior tendon sheath with care to avoid the N/V bundle;








- Outcomes:
    - in the report by Sammarco et al, 19 consecutive patients underwent FHL (FHL) tendon transfer and medial displacement
           calcaneal osteotomy for the treatment of Stage 2 posterior tibial tendon dysfunction;
           - FHL tendon was utilized for transfer because it approximates the strength of the posterior tibialis muscle and is stronger than 
                   the peroneus brevis muscle;
           - AOFAS hindfoot score improved from 62.4/100 to 83.6/100;
           - wtbearing preoperative and postoperative radiographs revealed no statistically significant improvement for the medial 
                  longitudinal arch in measurements of lateral talo-first metatarsal angle, calcaneal pitch, vertical distance from the floor to
                  medial cuneiform, or talonavicular coverage angle;
           - three feet had a normal medial longitudinal arch and six feet had a longitudinal arch similar to the opposite side following the procedure;
           - patient satisfaction was high: 10 patients satisfied without reservations, 6 patients satisfied with minor reservations, and 1 dissatisfied;
           - no patient complained of donor deficit from the harvested FHL tendon.
    - in the report by Moseir-LaClair, et al, the authors reviewed 26 patients with 28 pes planovalgus feet secondary to Johnson stage 2
           posterior tibial tendon insufficiency;
           - all were treated with flexor digitorum longus tendon transfer, lateral column lengthening, medial displacementn calcaneal osteotomy, 
                  and heel cord lengthening; mean patient age at surgery was 48.5 years;
           - mean follow-up to date is 5 years;
           - medial cuneiform to fifth metatarsal distance improved from -0.2 mm preoperatively to 7.6 mm postoperatively;
           - similarly, the talonavicular distance improved from 19.4 mm preoperatively to 10.9 postoperatively;
           - there were no nonunions;
           - four feet (14%) displayed radiographic signs of calcaneocuboid arthritis at follow-up;
           - only one was symptomatic requiring calcaneocuboid joint fusion;
           - the double osteotomy technique provides symptomatic relief and lasting correction of the pes planovalgus deformity associated 
                   with stage 2 posterior tibial tendon insufficiency at intermediate follow-up;
    - in the report by Guyton et al, the authors reviewed the results of 26 patients who had undergone the procedure at an average of 32 
           months prior to follow-up (range 12 to 70 months) with particular attention to objective functional parameters;
           - between 1993 and 1998, 26 patients underwent FDL transfer and medial displacement calcaneal osteotomy
           - all patients except three could perform a single-leg toe rise at follow-up, a maneuver none could perform preoperatively;
           - of these three, two cases were technical failures with loss of fixation of the FDL transfer early in the postoperative course,
                    ultimately requiring revision procedures including one subtalar fusion;
           - clinically assessed subtalar motion remained 81 +/- 15% of the contralateral side in those patients with unilateral disease;
           - pain relief was rated excellent by 75% and good by 16%;
           - function was felt to be markedly improved by all patients except the three who were unable to perform a single-leg toe rise;
           - median length of time to self-rated maximal medical improvement was 10 months;

    - references:
           - Treatment of stage II PTT dysfunction with flexor hallucis longus transfer and medial displacement calcaneal osteotomy.
           - Intermediate follow-up on double osteotomy and tendon transfer procedure for stage II posterior tibial tendon insufficiency.
           - FDL transfer and medial displacement calcaneal osteotomy for PTT dysfunction: a middle-term clinical follow-up.
           - Long-term follow-up of flexor digitorum longus transfer and calcaneal osteotomy for stage II PTT dysfunction.
           - Outcome of medial displacement calcaneal osteotomy for correction of adult-acquired flatfoot.
           - Functional results of posterior tibial tendon reconstruction, calcaneal osteotomy, and gastrocnemius recession.










Medial arch strain after medial displacement calcaneal osteotomy: an in vitro study.

Treatment of ruptured posterior tibial tendon with direct repair and FDL tenodesis.
      Shereff MJ. Foot Ankle Clin. 1997;2:281-296.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Clifford R. Wheeless, III, MD on Sunday, November 3, 2019 9:23 pm