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Peroneal sheath reconstruction (for peroneal tendon subluxation)

    Overview

    Learn the Peroneal sheath reconstruction (for peroneal tendon subluxation) surgical technique with step by step instructions on OrthOracle. Our e-learning platform contains high resolution images and a certified CME of the Peroneal sheath reconstruction (for peroneal tendon subluxation) surgical procedure.
    The mechanism of injury that results in peroneal tendon subluxation is as for an ankle sprain. However with a subluxing peroneal tendon the chance of the resultant instability and secondary pain settling with conservative management is far less than with an ankle sprain. In other words once the tendons have subluxed this tends to continue, irrespective of conservative management.
    Most patients will demonstrate their subluxation without being asked but on occasion it can be subtle and require careful dynamic ultrasound assessment of the peroneal tendons during ankle circumduction.
    With appropriate surgery and rehabilitation post-operative recurrence is rare.

    Indications

    INDICATION:
    Symptomatic peroneal tendon subluxation.
    SYMPTOMS & EXAMINATION:
    The patients will always have had a history of trauma , usually a weight-bearing and inversion injury. Their primary complaint will be one of ankle instability but laterally based pain following episodes of giving way of the joint is common. If patients have ankle pain outside of episodes of instability they may have developed co-existing peroneal tendon pathology or have also suffered inter-current injury to the ankle joint during the weight-bearing and inversion injury.
    As the injury occurs during weight bearing and inversion and consideration needs to be given to whether inter-current ankle pathology may co-exist, though this is not common.
    The diagnosis is not always clear cut. Some patients have more subtle degrees of tendon subluxation rather than a full “dislocation” of the tendons over the front of the Fibula. In most cases though the patient will be able to demonstrate the abnormal movement of the tendons with their own manoeuvre. In some though it needs to be encouraged during examination. This can be achieved by getting the patient to rotate the ankle clockwise & counter-clockwise whilst applying anteriorly directed pressure behind the tendons.
    If the tendons have sustained a tear or inflammatory change then they will be locally tender and may also be swollen. The more chronic (and frequent ) the episodes of subluxation , the more likely tears are to be produced in the tendons which will also require treatment.
    The ankle should also be examined comprehensively as per any weight-bearing and inversion injury.
    If intra-articular ankle joint pathology is suspected then an ankle arthroscopy may also be required at the time of surgery.
    INVESTIGATION:
    An MRI scan is required to rule out co-existing intra-articular ankle pathology and assess the state of the tendons in terms of intercurrent tears in particular.
    If the diagnosis of subluxation is in doubt then a dynamic ultrasound assessment can be diagnostic.
    NON-OPERATIVE ALTERNATIVES:
    This is one of those injuries which when it occurs is highly unlikely to settle without operative treatment.
    A standard ankle brace for lateral instability will often help but does not directly stabilise the Peroneal tendons.
    CONTRA-INDICATIONS:
    No specific ones. Patient compliance with 3 months of rehabilitation is required as are adequate vascular inflow and soft tissue cover.

    Setup

    GA or regional anaesthetic
    Popliteal block & local infiltration adequate for post-op pain relief
    Patient supine or slight lateral tilt
    (consider set up initially for ankle arthroscopy )
    Rolled-up sterile towels behind the operated calf to ease access to postero-lateral aspect of ankle
    Thigh tourniquet & Flowtron applied to non-operated calf.
    Peri-operative antibiotics and LMW Heparin , to continue 2-4 weeks whilst in cast.

    Operation

    A “lazy-J” shaped incision is placed behind the fibula to access to the peroneal sheath extending distally in the line of the peroneal tendons a few cm beneath the fibula tip.

    The sural nerve lies just posterior to the tendons in the fat layer and needs to be avoided.
    It is worth spending a little time carefully blunt-dissecting here to identify the nerve. In the distal part of the wound it on occasion may change its direction to become relatively more anterior to the tendons

    Fine tenotomy scissors are used to carefully dissect behind the fibula in the fat layer to identify the sural nerve, and avoid it.Fine tenotomy scissors are then used to dissect down onto the deep fascial layer over the fibula.
    The fat layer can be blunt dissected off the posterior aspect of the fibula using a swab once it is know where the sural nerve is. The fibula tip (1) and behind it the peroneal tendons(2) both sitting beneath the deep fascia.

    Incise the deep fascia of the peroneal retinaculum longitudinally and in the line of the tendons, fairly far anteriorly on the fibula (1). This soft tissue is needed to refashion the sheath and so a generous cuff of it is taken.It will be evident how far forward over the anterior aspect of the fibula that the peroneal retinaculum has been stripped. This of course varies.
    The incision through the peroneal retinaculum should extend just distal to the tip of the fibula and extend 3-4cm superiorly.

    A true sub-periosteal dissection is required to ensure this is of as substantial thickness as possible.

    Tears in the tendons should be excised and repaired. Synovitis and low lying muscle bellies (that probably predispose to tendon subluxation) should also be excised.Splits in the peroneal tendons (here in Peroneus Brevis,1) are not uncommon and should be repaired.
    The technique is to excise poor quality torn tissue, place a few longitudinal cuts in-between the tendon fibres (to encourage bleeding and healing) then “re-tubularise” the tendon (ensuring the internal fibres of the tendon are not exposed) using a running 2.0 Vicryl suture . Suture knots should not be left prominent and an absorbable suture should be used.

    Once the deep retinacular layer has been freed the peroneal tendons can be seen and should be carefully inspected.The sheath opened (4) to reveal the peroneus brevis (2) and longus (3) tendons.
    Note how far anteriorly over the fibula the extent of the peroneal tendons subluxation has been (1). The attachment of the deep fascia has been stripped forward by the recurrent subluxation.
    The tendons should be thoroughly inspected. If tears are present they should have their edges excised and then be repaired with a running 2.0 Vicryl suture.
    The proximal tendons and musculo-tendinous junction should also be inspected. It is not uncommon for the muscle belly of one or both Peroneals to extend down to behind the distal fibula. This will add extra and unneeded bulk into the Peroneal sheath ( which may predispose to subluxation) and such low muscle tissue should be excised off the tendons.
    (see the results section for a paper which discusses this point)

    The free edge of the peroneal retinaculum (2) is trialled behind the fibula to gauge points of attachment into the periosteum here.Note the small redundant cuff of deep fascia (1) left after the retinaculum has been mobilised. The attachment point of this would normally be to the posterior margin of the Fibula, seen here overlying the tips of the forceps.
    The fascial tissue is better quality proximal to the tip of the fibula and tends to become more friable distally. Proximal to the fibula tip is where the key stabilisation occurs.

    The Calcaneo-Fibular ligament(1) can be identified in the bed of the peroneal tendons(4) and at the tip of the fibula(3).
    A tear in the peroneus brevis has already been repaired, 2.
    This deep periosteal tissue (4) is the point that the deep fascia will be sutured back into. It is variable in its quality and should be preserved carefully throughout the approach.

    A good illustration of how far anteriorly the anterior attachment of the peroneal sheath /deep fascia (3) can become stripped over the fibula (2) by recurrent subluxation.
    This is a different case to that illustrated in the other images.

    The bony peroneal groove behind the fibula (1) may be relatively shallow for the tendons and on occasion is usefully deepened using a 5mm high speed burr(2), prior to retinacular reattachment.An alternative is to impact the posterior cortical bone carefully using a fine osteotome
    If deepening the bony groove is going to be done then care must be taken to leave adequate periosteum attached to the posterior aspect of the Fibula to re-attach the sheaths edge to, which is the key part of the stabilisation
    The anatomy of the area should be recalled and in particular that deep and anterior to the inferior aspect of the Fibula is the ankle joint itself which should not be breached.
    Alternate “groove” deepening procedures are described also including osteotomising the distal Fibula.

    If the peroneal groove is being deepened (1) it is important to limit the extent of periosteal stripping .Vital to anchoring the sheath(2) into this area is intact deep periosteum behind the fibula and this must be preserved.
    Here the sutures have been placed initially into the free edge of the retinaculum.

    A good bite of the periosteum and soft tissue(3) behind the fibula(1) is required for each suture to anchor the peroneal sheath.
    Here an Arthrex Fibrewire suture is being used, though a heavy gauge vicryl suture will also suffice.

    Anchor the sutures initially to the periosteal layer behind the fibula. A good bite of periosteum is required and the suture should be locked into place. Test its “pull-out” and under-sew again if it is pulling out.Whether to lock each suture into the edge of the sheath before anchoring into the periosteum or alternatively to place all the deep sutures before engaging the more superficial sheath depends on preference.
    Whichever is chosen all sutures should first of all be placed before tying off under appropriate tension, with the tendons sitting in a reduced position.
    Care needs to be taken to ensure that the tendons are not ensnared nor directly abraded by the deep sutures by tying these too tightly.
    The peroneals and the free edge of the retinaculum will need to be held by an assistant in an appropriate reduced position as the sutures are tightened into place.

    The peroneals and the free edge of the retinaculum will need to be held by an assistant in an appropriate reduced position as the sutures are tightened into place.Multiple anchoring sutures(1) are required posterior to the fibula ,extending down towards the region of the CF ligament, and if the tissue quality permits distally too.
    The deep fascia is marked by the yellow line (3) and this will be tied into the back of the fibula with the sutures marked 1.
    A tear has been repaired in the peroneal tendons(2).

    The reconstructed peroneal sheath sutured into the posterior aspect of the Fibula(2). The fibula(1) and redundant cuff of deep fascia (3) sit anteriorly.
    The objective is getting close apposition of the deep fascia onto the back of the fibula, and has visibly been achieved.
    The ankle should be circumducted to demonstrate that the repair is sound and additional sutures placed if it is not.
    The fat is closed carefully, specifically avoiding the sural nerve which has been located during the exposure.
    Skin closure is using a subcuticular stitch.

    Post Operative

    4 weeks in short post-operative cast , non-weight bearing
    The first 2 weeks of this in back-slab
    Dressing change at 2 weeks
    By 4 weeks into a medio-lateral stabilised ankle brace and commence full weight bear as soon as able
    Physio to commence , working on in-line ankle range and strength , progressing to balance and proprioceptive rehabilitation, including peroneal strengthening.
    My own recommendation is that no specific mobilisations ( active or passive) are used on the subtalar joint. Circumducting the ankle does risk over-stressing the repair at an early stage. Normal movement will be regained during functional rehabilitation phase.
    A static bike from 5 weeks , Cross-training from 7-8weeks and light -jogging likely to commence sometime after 10 weeks.
    Initial return to sport is likely to require an appropriate brace for the first month

    Recommended Reading

    Return to sports and clinical outcomes in patients treated for peroneal tendon dislocation: a systematic review.
    Knee Surg Sports Traumatol Arthrosc 2016 ; 24 ; 1155-1164
    P Van Dijk , A Gianakos ,G Kerkhoffs J Kennedy.
    Systematic review of 14 papers with either simply peroneal retinacular reconstruction or this and additionally deepening of the bony groove.Return to sport in 100% of those with groove deepening and retinacular reconstruction versus 83% with just peroneal retinacular reconstruction.1.5% recurrence rates in both groups and 90% satisfaction rates in both groups .
    Comparison of Outcome After Retinaculum Repair With and Without Fibular Groove Deepening for Recurrent Dislocation of the Peroneal Tendons.
    Foot Ankle Int. 2014;35(7);683-9
    Cho J , Kim JY, Song DG, Lee WC
    13 patients were treated with both techniques and 16 with just retinacular repair. No significant differences in outcome but operative time significantly quicker in the retinacular group with no bony procedure.
    Prevalence and role of a low lying peroneus brevis muscle belly in patients with peroneal tendon pathologic features: A potential source of tendon subluxation.
    J Foot Ankle Surg .2015 Sept-Oct;54(5):872-5
    Mirmiram R, Squire C, Wassell D.
    Retrospective review of 50 patients undergoing peroneal tendon surgery , comparing their MRI results with respect to a low lying muscle belly of Peroneus Brevis to Peroneal pathology. Far more patients with a low lying muscle belly than tendon subluxation but of those with peroneal subluxation as a starting point 9 had a low lying muscle belly. This did not achieve statistical significance.

    Reference

    • orthoracle.com

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