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Ulnar head hemiresection with interposition and extensor reconstruction

    Overview

    Learn the Ulnar head hemiresection with interposition and extensor reconstruction surgical technique with step by step instructions on OrthOracle. Our e-learning platform contains high resolution images and a certified CME of the Ulnar head hemiresection with interposition and extensor reconstruction surgical procedure.
    Patients with distal radio-ulnar joint (DRUJ) arthritis, particularly but not exclusively due to systemic inflammatory arthritis, may develop painful dysfunction of their DRUJ, with well localised pain, restriction of forearm rotation and, potentially, extensor tendon dysfunction. The extensor tendons pass from the forearm into the dorsum of the hand in 6 different compartments, each containing different tendons.
    On the radial side of the wrist, the 1st and 3rd dorsal compartments carry tendons to the thumb, and the 2nd dorsal compartment the tendons of the two radial wrist extensors. The finger extensors to all four fingers (extensor digitorum communis- EDC) pass in the 4th dorsal compartment on the dorsal aspect of the radius (along with the independent extensor to the index finger, extensor indicis proprius (EIP)). The independent extensor to the little finger, extensor digiti minimi (EDM) passes in the 5th dorsal compartment, which is found immediately overlying the longitudinal joint line of the DRUJ, and the extensor carpi ulnaris (ECU) tendon is found in its own compartment (the 6th dorsal compartment), usually found in a groove on the dorso-ulnar aspect of the ulnar head.
    Due to its position over the DRUJ joint line, the extensor digiti minimi (EDM) tendon is vulnerable to synovitis and tenosynovitis due to attrition from ulnar head osteophytes, on occasion proceeding to rupture. Tenosynovitis due to the DRUJ arthrosis may cause attenuation and sequential rupture of the tendons of EDC, a condition eponymously called Vaughan-Jackson syndrome. Classically tendon loss usually progresses sequentially from ulnar to radial (little-ring-middle-index). The earliest potential clinical sign, an inability to independently extend the little finger, may be masked by continuity of the EDC tendon to the little finger still enabling the little finger to be extended actively with the adjacent digits. Even after this EDC tendon has ruptured, the little finger may appear to actively extend due to connections between the EDC tendons in the hand, called junctura tendinae. Patients with DRUJ arthritis who are not ready to accept surgery should therefore be instructed to ensure that they can independently extend their little finger every month, seeking review if this becomes increasingly painful or difficult.
    Depending on how many tendons have ruptured, different reconstructive options exist through a combination of “buddying” tendon stumps together into functional units with an appropriate relative tension (little combined with ring or the middle combined with index) and transferring motor units (tendons from other muscles) onto the combined distal stumps in order to restore extension of the digits. This will improve function, but the surgery should be combined with steps to debride the DRUJ and “smooth-off” the ulnar head even if the joint function is good to minimise the risk of further tendon ruptures.
    One key point with this technique is to be sparing with the resection of the ulnar head in order to minimise radio-ulnar convergence, but be sure to remove enough distally to eliminate ulno-carpal abutment; this technique produces good clinical results.


    Indications

    INDICATIONS
    Reasons to consider ulnar head and DRUJ debridement include arthritis with local symptoms and pain not responding to conservative measures, stiffness with functional restrictions (NB remember to check the proximal radio-ulnar joint as another potential source for pathology that may restrict forearm rotation- the presence of isolated wrist pain and the absence of clinical irritability at the level of the elbow may be enough in patients with OA, but for those whose underlying problem is Rheumatoid, pre-operative imaging of the elbow should be obtained) and, in particular, associated extensor tendon dysfunction.
    SYMPTOMS & EXAMINATION
    There are certain key features to look for on examination, as follows:
    Pain in the DRUJ with localised (longitudinal) joint line tenderness. Pain worsened by external radio-ulnar compression (rotation of the forearm causing pain that is worsened by the examiner gripping to compress the radius and ulna towards one another at the level of the junction of the central and middle thirds of the forearm). Tenosynovitic pain (a longitudinal forearm pain that is worse with resisted extensor activation, particularly of the little finger).
    Stiffness of forearm rotation, remembering to check the proximal radio-ulnar joint as an alternate source of pathology (as noted above).
    Confirm extensor tendon continuity or note any inability to extend the fingers. The fingers may be held flexed for one of several reasons:
    the MCP joints may be diseased and subluxed (in which case the history will usually be of slow progression); depending upon the extent of MCP joint disease, passive correction may be possible.
    the palmar capsule of the MCP joint may become impaled onto an osteophyte of the metacarpal neck; this usually happens as an acute event, and is associated with a painful loss of active and passive extension of the MCP joint, often with the digit slightly deviated towards the side where the capsule is caught.
    the extensor tendons may not be held centrally over the metacarpal heads, and may sublux (usually to the ulnar side), and so not be able to extend the finger at the MCP joint. If the MCP joint can be passively corrected and so the extensor tendons return to their normal position, the patient may be able to hold the finger extended, but not actively extend from a position of MCP joint flexion.
    the extensor tendons may have ruptured at the level of the wrist- this is usually due to DRUJ arthritis with secondary tenosynovitis and/or attrition over an ulnar head osteophyte. In rheumatoid patients, this is often referred to eponymously as Vaughan-Jackson syndrome.
    the extensor muscles may have been denervated by posterior interosseous nerve (PIN) or radial nerve lesions. Synovial cysts from the elbow can track into the radial tunnel (between the two heads of supinator) and compress the PIN.
    Remember to perform the tenodesis test as this will give you a good indication as to whether or not the tendons are in-continuity. This clinical test uses the effect of wrist motion on the relative tensions in the extrinsic flexor and extensor tendons to the fingers to provide an indication of the integrity of the tendons. When the muscles are relaxed, palmar flexion of the wrist will reduce tension in the finger flexors and increase tension in the finger extensors, so causing the digits to extend; the opposite happens when the wrist is dorsiflexed. If a tendon has ruptured, the balance between the flexors and extensors will be lost, and so the normal cascade of the digits (the normal pattern of increasing flexion of digits from the index to the small finger) will be lost. (You can try this on your own hand to see the effect in action.)
    In practice, I look at the resting posture of the hand, trying to passively correct the MCP joints and, if correction is possible, see if the digits can be held straightened by the patient. If fingers fall down, I then undertake the tenodesis test with passive wrist motion into palmar and dorsi-flexion causing motion of the fingers with digits whose extensor tendons have ruptured remaining more flexed than would be expected; however, this can only be performed if condition of the wrist allows which, in patients with inflammatory arthritis, may not be the case. If the none of the fingers can be actively extended or held in active extension after passive correction, it is important to use the tenodesis test to rule out neuromuscular cause as if the tendons are in-continuity, there should be passive digit motion seen with wrist palmar and dorsiflexion. (Clinically, you should also check whether other muscles innervated by the PIN units are working, such as extensor pollicis longus).
    If the digits cannot be actively extended, but can be passively corrected and held in an extended position actively, look for extensor mechanism subluxation (the tendons “dropping off” the heads of the metacarpals, usually in an ulnar direction) when the digits are flexed as this may explain inability to actively extend the digits; if the fingers are significantly ulnar-deviated, the patient may not be able to actively hold a passively extended digit straight due to the joint deformity in combination with tendon subluxation.
    If the digits cannot be passively extended, examine and image the hand rule out MCP joint-level problems such as MCP joint subluxation.
    IMAGING
    Plain film imaging to confirm presence of arthritis, remembering to image the elbow as well if forearm rotation is limited actively and passively.
    Ultrasound scan to assess synovitis, tenosynovitis and tendon integrity.
    MRI of the elbow may have a role if it is suspected that a patient with inflammatory arthritis may have a synovial cyst arising from the elbow and compressing the PIN in the radial tunnel through supinator.
    ALTERNATIVE OPERATIVE TREATMENT
    Ulnar head excision (Darrach’s procedure): excision arthroplasty of the DRUJ by removing the ulnar head known as Darrach’s procedure. This is a relatively straight-forward procedure to perform, but can be complicated by mechanical problems, in which case salvage is difficult.
    Removal of the ulnar head causes radio-ulnar convergence (the radius and ulna moving closer together than normal, as the ulnar head is no longer present to hold the bones apart, particularly when gripping firmly).
    There may be instability of the radius at the new ulnar stump (the radius clicking to the palmar and dorsal aspect of the ulnar stump- remember that while people (and learning resources) commonly refer to ulnar head instability with considering the DRUJ, the ulna is in fact the fixed axis about which the radius rotates, so theunstable bone is, in fact, the radius).
    There is concern that removing the ulnar head may contribute to ulnar translation of the carpus.
    Sauve-Kapandji (DRUJ fusion with distal ulnar segmental excision): this procedure uses fusion of the ulnar head to the radius to maintain bony support of the ulnar side of the wrist), enabling forearm rotation by excising a segment from the ulnar neck. However, this will not address any ligamentous contribution to ulnar carpal drift. Additionally, as the ulnar neck is resected to allow rotation, this will mean that the stump of the ulna will necessarily be relatively proximal on the radius which, given the risk of instability between the radius and the ulnar stump increases with more proximal ulnar neck cuts, increases the risk of convergence and instability.
    Hemiresection interposition: Bowers (1985) described a hemi-resection of the ulnar head primarily to address problems arising following radial fracture malunion. He interposed an ulnar-based retinaculo-capsular flap into the resected joint line. The procedure is said to require an intact / competent / reconstructable triangular fibrocartilaginous complex (TFCC) to be successful. The ulnar-based flap of the composite DRUJ capsule and extensor retinaculum that is interposed into the joint after resection is thought to potentially draw the ECU tendon further dorsal and so to help with stability of the resected distal ulna. Bowers also described sometimes using tendon interposition as an anchovy into the resected joint line (as some have used following trapeziectomy).
    Ulnar head replacement: (hemiarthroplasty or total constrained). Implants exist, but clinical experience is relatively limited. The ulnar head articulates with the radius, and provides structural stability, although soft-tissue reconstruction is unreliable and so instability is a potential concern. Nonetheless, implantation of an ulnar head replacement into the unstable stump of the ulna to address instability following a Darrach or Sauve-Kapandji procedure.
    A constrained implant is available to address an unstable DRUJ, particularly after failed ulnar head resection (the Scheker prosthesis), but I am concerned about the long-term implications of inserting a constrained implant into a joint that normally has multiplanar motion.
    NON-OPERATIVE MANAGEMENT
    Unless there are compelling reasons not to operate, in my opinion non-surgical management is inappropriate in the presence of tendon rupturing, if only to protect the remaining tendons.
    CONTRAINDICATIONS
    As with many musculoskeletal procedures, inserting foreign material is inappropriate in the presence of active infection, and carries an increased risk if there has been a previous infection in the DRUJ.
    DRUJ instability without the potential for TFCC reconstruction is at least a relative contra-indication to ulnar head resection, given the potential for instability in any event. However, for low-demand patients, the limited resection involved with an ulnar head debridement usually means that surgery can be safely undertaken.

    Setup

    Usually, dorsal DRUJ and extensor tendon surgeries will be undertaken with the patient supine with their arm on a hand table. However, this patient had a simultaneous elbow replacement, hence the patient is in a lateral position; this made access for some of the images more difficult.
    Surgery can be undertaken using general or regional anaesthesia, when a tourniquet can be used. However, as this patient was undergoing a simultaneous total elbow replacement, which was expected to exhaust the available safe tourniquet time, the forearm surgery was undertaken using the same infiltration as would be used for Wide Awake Local Anaesthetic No Tourniquet surgery (WALANT); this approach makes use of field infiltration of relatively large volumes of local anaesthetic pre-mixed with adrenaline, so that a bloodless field can be achieved despite not using a tourniquet. There is no reason why the procedure could not be undertaken using solely WALANT techniques, which would be safer for the patient and afford a quicker post-surgical discharge.
    If a tourniquet is to be used, this could be applied either above or below the elbow; below elbow tourniquets are usually applied to a lower cuff pressure, and cause less ischaemic muscle pain.
    If patients are going to remain awake, remember that many patients will have a systemic inflammatory arthropathy, and so may need particular care when positioning them to ensure their other joints do not become painful during the course of surgery, particularly their shoulder and elbow on the side that is being operated upon.
    As with any tendon surgery, be sure that the limb is prepared to allow for any potential extension of the surgical field to locate the tendons proximally.

    Operation – 1

    This patient has a systemic inflammatory arthritis. The radiograph shows the ulnar head appears to be long in relation to the radius on a PA film, obtained with the arm in neutral rotation.
    It is called positive ulnar variance when the ulna is longer than the radius. The distal-most point if the ulnar head (not including the styloid process) lies distal to the mid-point of the sigmoid notch on the radius.
    The gold dots mark the palmar and dorsal lips of the sigmoid notch. The red line marks where the midpoint lies in relation to the ulnar head.
    While there is variation between individuals, in most the ulnar head lies up to 2mm proximal to the midpoint of the sigmoid notch , called negative ulnar variance. A relatively long ulna, particularly when acquired, for exmple following a distal radial fracture that heals with shortening, can cause ulno-carpal abutment.
    There is little evidence of osteophyte formation at the DRUJ, a fact worth remembering when seeing the intra-operative findings.

    Position the hand to overcome any tendency for it to supinate during the procedure so that you do not drift in an ulnar direction during the surgical approachThe arm tends to externally rotate when the shoulder is abducted. While it may not initially be obvious how this pertains to wrist surgery, try lying down and positioning your hand flat with your arm abducted to 90 at the shoulder, and with your arm closer to your side; note how much tighter the shoulder feels with the arm in an abducted position.
    Particularly with an awake patient (blocked, or Wide Awake Local Anaesthetic No Tourniquet- WALANT), positioning the hand table to allow the arm to be held at approximately 45 degrees abduction will enable the tendency for the hand to supinate to be minimised.
    To enable your assistant to concentrate on retraction and active assistance, the forearm and hand can be supported by padding more under the ulnar side, which will make the hand rotate into a more pronated position; in the picture, this is achieved by the more distal of the two padding rolls (under the hand- P- which us under the hypothenar eminence). However, Distal Radio-Ulnar joint (DRUJ) pathology may limit the amount of rotation possible (and may the Proximal Radio-Ulnar joint, which may not be so immediately obvious when focusing on the wrist!), so you will need to be aware of the position of the hand and adapt your position by the patient, and particularly the line of your approach to accommodate any fixed pronation.
    When treating patients with systemic inflammatory arthropathies, such as Rheumatoid, be careful to assess the shoulder, elbow and forearm prior to deciding on the type of anaesthetic to be used. While the surgery itself can be undertaken using regional or WALANT techniques, an awake patient with multiple upper limb joint pathologies may not be able to tolerate maintaining the required position.
    General anaesthetic or sedation in addition to peripheral anaesthesia may be required in these patients.

    Define the surface anatomy, marking key surface landmarks of the radius and ulnaMark out the bony anatomy of the distal radius (R) and ulna (U), defining the distal radio-ulnar joint (DRUJ- marked D at it’s distal limit). By feeling for the groove that the Extensor Carpi Ulnaris tendon (ECU- marked E proximally) runs in, the path of the EUC can be defined; this is important as the tendon in its groove / sub-sheath is an important dynamic stabiliser of the DRUJ, and the tendon will need to be replaced and stabilised if it has subluxed in a palmar direction.
    Defining Lister’s Tuberosity (L), while not important in this procedure, is always helpful with dorsal wrist surgery as a general landmark.

    This cross-section drawing of a right forearm at the level of the DRUJ shows the relative position of the 6 dorsal extensor compartments (numbered) in relation to the radius (R) and the ulnar head (U).
    Note that the 5th compartment, containing the EDM tendon, overlies the DUJ, and so is vulnerable to attrition from an ulnar head osteophyte. The ECU tendon may lie outside the groove of the 6th compartment, to the palmar side, and may need to be reduced and stabilised to improve ulnar head stability.

    This drawing shows the dorsal wrist compartments topographically.
    1.Extensor pollicis brevis & abductor pollicis longus
    2.Extensor carpi radialis longus & brevis
    3.Extensor pollicis longus
    4.Extensor indicis & Extensor digitorum
    5. Extensor digiti minimi
    6.Extensor carpi ulnaris

    Exposure of the DRUJ over a 5cm length is needed to undertake the joint and tendon surgeryWhilst concerns about scar contracture are not an issue on the dorsum of the wrist in the same way that incisions directly cross flexion creases are to be avoided on the palmar surface, the Z-design affords excellent exposure of the DRUJ, the ECU (at the base of the ulnar flap) and the Extensor Digiti Minimi tendon (EDM, which runs in its own retinacular compartment along the line of the radio-ulnar joint at the base of the radial flap). Flaps are raised to optimise exposure and minimise the risk of damage to the dorsal branch of the ulnar nerve. As an alternative, if there is a high likelihood of future wrist surgery being required, a more midline longitudinal incision can be used.
    The 4th dorsal compartment, containing the Extensor Digitorum Communis (EDC) and Extensor Indicis Proprius (EIP) tendons, can be accessed to look for tenosynovitis and tendon attrition by opening the retinaculum at the base of the radial flap and, if needed, the flap can be extended radially to open the 4th dorsal compartment more fully in order to address any issues with the tendons that are identified. (This was not required in this patient’s case.)

    Raise full-thickness skin flaps being careful to protect the sub-cutaneous nervesThe relatively radial position of the incisions means that dorsal cutaneous nerves, in particular dorsal branches of the ulnar nerve, will usually be outside the surgical field as long as full-thickness flaps (down to the level of the retinaculam) are raised.
    Some blunt dissection once you have entered the subcutaneous fat, particularly on the ulnar side, will reassure you that no important branches are in danger. Remember that the nerves run deep to the veins.

    Raise the flaps to give good exposure from the 4th to the 6th dorsal compartment, including of the dorsum of the DRUJ.

    Take care with haemostasis as you proceed to minimise the risk of bleeding once the tourniquet is releasedThis case was undertaken without a tourniquet, so careful haemostasis was important, as was ensuring that the draping did not create a constriction band (which acts as a venous tourniquet). However, even when a tourniquet has been used, careful haemostasis as you proceed will reduce bleeding after the tourniquet has been released and so the potential for haematoma formation and post-operative problems, including pain.

    Feel for the joint line of the DRUJ to show you where to incise to enter the 5th dorsal compartmentThe EMD tendon runs in the 5th dorsal compartment directly over the joint line between the ulnar head and the sigmoid notch of the radius.
    In the picture, my thumb is over the joint line, with the ulnar head marked U.

    Feel for the groove for the ECU tendon at the dorso-ulnar aspect of the ulnar headThe ECU tendon needs to be in its subsheath in the groove that can be felt on the dorso-ulnar aspect of the ulnar head in order to stabilise the DRUJ.
    Defining the groove is therefore important to ensure that the tendon is confirmed to be in place, or it needs to be re-sited and stabilised during the procedure. The bony groove can usually be felt relatively easily, and ironically is easier to feel if the tendon is subluxed. If the ECU cannot be found, look proximally for the tendon, which received muscle fibres very distally in the forearm.
    The ECU subsheath also marks the ulnar / palmar limit of the dorsal capsular flap that will be raised to access the DRUJ. Take time to carefully define where the groove lies before starting to raise deeper tissue flaps; in the picture, my thumb overlies the groove that ECU runs in on the dorso-ulnar aspect of the ulnar head.

    Identify the EDM tendon away from the 5th dorsal compartment over the dorsum of the DRUJ to minimise the risk of damage to the capsuleParticularly when tendon rupture has occurred, there is a danger that you may damage any remaining dorsal DRUJ capsular attachment to the radius if you enter the 5th dorsal compartment directly expecting to find a tendon; you can end up dissecting through the capsule, which may be adherent to the retinaculum after tendon rupture, and so damage a flap that you may need to interpose into the joint later in the procedure. By looking for the EDM tendon (or its stump) distally, you will be less likely to damage the capsule when entering the 5th compartment.
    In the picture, I am looking distal and slightly ulnar to the DRUJ joint line (J) in order to find the EDM tendon stump; note that the forceps are mobilising the retinaculum, and not the tendon itself at this stage. The tendon stump will usually be swollen and adherent to the retinaculum and the floor of the 5th dorsal compartment, distal to the DRUJ; you will usually be able to feel (and often see) the swelling, so finding the end is not usually too hard.
    I try to work directly onto the stump at this stage, rather than opening the retinaculum over the DRUJ to keep my options open for how and where I divide the retinaculum over the DRUJ until I have confirmed that the EDM tendon has ruptured.

    The tendon stump can be seen distally by the tenotomy scissor blade, ulnar to the forceps (T); the retinaculum has not been divided proximally yet (R).

    Mobilise the tendon stump from surrounding scar tissues being careful to minimise damage to its bed to reduce the potential for adhesionsThe EMD distal stump (T) will need to be mobilised to allow for its reconstruction, be that side-to-side to the ECD to ring (or little, if still intact) or to the transferred EIP tendon (after relative tensioning and joining to the EDC tendon to the ring finger, if this has also ruptured).
    This can be undertaken later, but I prefer to mobilise the tendon at this point as oozing from the ulnar head may obscure the field once the bony surgery has been completed, whether or not a tourniquet is used.
    Note how the tendon is attenuated proximally, with the ragged ends still adherent to the 5th compartment tunnel (passing over the scissors); these will be divided to leave an healthier tendon stump for the reconstruction phase of the operation (later).

    Inspect the dorsal DRUJ capsule to see if there is a perforation through the capsule that needs to be incorporated into the capsular flapHaving mobilised the EDM distal stump (T), the retinaculum of the 5th compartment over the DRUJ can be entered. When approaching the DRUJ without tendon rupture, I open the retinaculum over the EDM tendon longitudinally to then mobilise the tendon and expose the DRUJ dorsal capsule.
    When the tendon has ruptured, the dorsal capsule will probably have a hole worn through it by the rough osteophyte on the dorsum of the ulnar head, and so not be as robust. When the dorsal capsule is attenuated, I often use the retinaculum to reconstruct the dorsal capsule; the tissues attached to the radial margin may be friable and so not readily accept a stitch under these circumstances, but the retinacular attachments are usually secure. I therefore raise a radially-based retinacular flap (here held by the forceps- R).
    You can see the perforation in the capsule (P), revealed now the retinaculum has been raised (R).

    Use the position of any perforation to determine whether to raise the DRUJ capsular flap with a radial or an ulnar baseHaving completed the ulnar head resection, you will want to use the dorsal tissues to stabilise the DRUJ, and potentially interpose tissue into the resected joint line.
    The EDM tendon, if intact, can be left superficial to the retinaculum on closure, and will be if reconstructed. Therefore, depending upon the state and quality of the tissues, the dorsal capsule and the retinaculum to the ulnar side of the radius can both be used for stabilisation on closure; however, until you have released the retinaculum to expose the dorsum of the DRUJ, you will not know what condition the capsule is in.
    Therefore, when there a perforated capsule, I prefer to release the retinaculum from its ulnar side (towards the dorsal margin of the 6th dorsal compartment, where the ECU tendon runs) and raise a retinacular flap that is radially-based to expose the dorsum of the DRUJ, so that when I close there will be a tissue layer that can be more securely reattached to reconstruct the dorsal capsule.


    The retractor (L) is holding the retinacular flap that has been raised. (To better demonstrate the deformed ulnar head, the retractor is also pulling the remaining capsule proximally and radially.) I have made a horizontal split in the line of the retinacular fibres proximally to elevate the flap.
    The ulnar head osteophyte (O) has caused the EDM tendon to rupture, the distal stump lying distally (T).
    There is little DRUJ capsule remaining on the ulnar side (the hole being held open by the forceps). The remaining retinaculum has been left intact proximally (R).

    Start to raise a DRUJ capsular flap by making a transverse incision at the distal margin of the ulnar head, just proximal to the radio-ulnar ligaments of the triangular fibrocartilaginous complex (TFCC)If the EDM tendon is intact, it will need to be retracted; this was not the case here- the retractor (L) is holding the skin and the previously-raised retinacular flap out of the way.
    I start to raise the flap by making a transverse incision at the distal margin of the ulnar head, just proximal to the radio-ulnar ligaments of the triangular fibrocartilaginous complex (TFCC), and elevate the capsule close to its ulnar insertion (leaving a small cuff for reattachment of the capsule or the retinaculum when closing). If the dorsal capsule is intact, I start at the radial attachment just proximal to the distal edge of the radius to preserve the radial attachment of the radio-ulnar ligaments, and work in an ulnar direction being careful not to damage the TFCC; if, however, I can see into the DRUJ through a perforation, I will raise the flap in the way that makes best use of the pre-existing hole to preserve tissue for interposition, so the raising of the flap is a la carte, dictated by the surgical findings. Here, I started on the ulnar side, incorporating the hole into the flap.
    The forceps are maintaining tension in the capsule (which is surprisingly thick away from the perforation) and lifting the capsule up so I can be sure not to injury the TFCC itself.
    There will usually be a hole / perforation in the triangular fibrocartilage (TFC) itself- this is only seen distally through the capsular hole (cannot be seen in this picture). The TFC perforation is not of importance in and of itself, as the ulnar head resection will address any potential abutment, but loose flaps and synovitis can be removed when the DRUJ cavity is debrided.

    Complete mobilisation of the capsular flap by releasing the proximal end, so exposing the junction of the head and shaft of the ulna.Having extended the distal incision to the dorsal aspect of the ECU groove, the capsule is freed longitudinally from the ulnar head to the junction of the head and neck, then the flap is raised back towards the radius, as seen here. The forceps are holding and elevating the capsule (C), and the marginal osteophyte of the ulnar head (O) can be seen in the joint.

    The EDM tendon has been attenuated by the osteophyte around the ulnar head marginsHere, the distal stump of the EDM tendon has been lifted by the forceps to demonstrate it; the tendon stump (T) is distal to the ulnar head (U) with the hand resting in this position.

    The remaining dorsal capsule flap is thick and robust, despite the perforation by the ulnar head osteophyte
    This can be used either to stabilise the DRUJ after excision, or to interpose into the joint line.

    Confirm the integrity of the tendons of extensor digitorum communis and extensor indicis proprius by entering and inspecting the 4th dorsal compartmentThe tendons of extensor digitorum communis (EDC) and extensor indicis proprius (EIP) lie in the 4th dorsal compartment, dorsal to the radius and ulnar to the 3rd dorsal compartment (which is immediately ulnar to Lister’s tuberosity, containing the tendon of extensor pollicis longus).
    The route selected to enter the 4th dorsal compartment will depend upon the way that you have exposed the DRUJ. If the retinaculum over the 5th dorsal compartment (over the DRUJ joint line, containing EDM) has been released from its ulnar side, as was the case here, I will partially release the retinaculum from the radius.
    In this way I enter the 4th compartment from the ulnar side, leaving as much attached to the radius as possible so that I can still use the retinaculum to reconstruct the DRUJ capsule on closure.
    Where possible I will leave the dorsal DRUJ capsule attached to the dorsum of the sigmoid notch of the radius to be able to use it to reconstruct the DRUJ or to interpose into the resected joint line at the end.

    Identify the EDC and EIP tendons one by one to confirm all are intactHaving entered the 4th dorsal compartment, there may be tenosynovitis to remove; fortunately that was not required in this case. The retinaculum is being retracted (R) to expose one of the tendons (T), which can be seen radial to the capsular remnant. From the position of the ulnar head (U), you can see that any attenuation of the EDC tendons will be through tenosynovitis rather than direct attrition from the ulnar head osteophyte. It is important to inspect all the tendons of EDC to confirm their integrity. EIP is the tendon that lies deepest in the 4th dorsal compartment.

    Inspect and confirm the integrity of the EDC tendon to all of the fingersThe tendons can be individually identified and delivered into the field through the retinacular window, removing any tenosynovitis to ensure no tendon attenuation (which may influence your tendon reconstruction) and confirming the tendons pull through to extend the relevant finger.
    Tendons already checked can be held in a tendon hook so that you can systematically work your way through all the tendons.

    Confirm which is the EDC tendon to the ring finger so you can join the distal stump of EDM to itIn this patient, the only deficit was the extensor to the little finger; I therefore planned to reconstruct the extensor by buddying the distal stump of EDM onto the ECD tendon to the ring finger, as this would restore extension with minimal morbidity; restoring independent extension of the little finger by transferring EIP would not be justified!
    I am using a Watson Cheyne dissector to lift the EDC tendon (T) out of the wound to confirm that the ring finger (R) is extending; the tendon itself is healthy.

    Operation – 2

    Decide when you will perform the tendon reconstructionUsually I will establish the extent of tendon damage to the EDC tendons and the integrity of EIP, in order to confirm the extensor reconstruction that I will undertake.
    In most cases, I will leave the reconstruction until after I have completed the DRUJ surgery, if only to minimise the risk of damaging any reconstruction by catching the digits inadvertently whilst manipulating the hand and wrist during exposure of the ulnar head. However, if the only tendon(s) damaged are EDM and EDC to the little finger and to reconstruct I will simply buddy the distal stump onto the intact tendon of EDC to the ring finger, the reconstruction can more easily be undertaken at this stage as the tendons have already been identified, and the reconstruction will not interfere with the DRUJ surgery. (In the event of the little finger being caught and so the tendon reconstruction being damaged, revising it would be straightforward, so I am less concerned about any risk to the tendons from potential damage when exposing the ulnar head.)
    In the picture, the tendon hook is holding the EDC tendon to the ring finger (T), identified in the previous slide. I am confirming adequate mobility of the distal stump of the EDM tendon (S).

    I pass the stump of EDM through a small longitudinal split in the EDC to ring finger.The EDC to ring can be split with a single pass of a #15 scalpel blade, or using a pointed tendon braiding instrument; unfortunately the pictures of this step were not clear.
    Having performed the tendon pass (weave), I secure the EDM tendon stump where it passes through the EDC tendon with a non-absorbable suture. I use 4/0 Ethibond or Ticron, but the precise suture used is not important; I do however think it is important to use a braided suture to minimise the likelihood of the knot slipping, and to use 4 or 5 throws to secure your knot.
    Try to be sure to pass the needle through one side of the EDC tendon, exiting in the split made through which the EDM stump is passing, then through the EDM tendon, and then through the other side of the split EDC tendon.
    I then pass the needle back to make a horizontal mattress suture and so hold the tendon weave securely. (In the picture, the needle is on the 1st pass through the EDM stump, having secured the ulnar side of the split in the EDCC tendon already.)

    Confirm the tension in the reconstructed extensor tendon before passing the remaining sutures to secure the tendon reconstructionPerform a tenodesis test before stitching the tendons anymore; by confirming the tension in the tendon reconstruction with only one suture passed, if you need to adjust the tension there will be fewer stitches to remove, and less damage done to the tendons.
    The tenodesis test uses changes in the relative resting tension of the flexor and extensor tendons with wrist palmar and dorsiflexion to demonstrate tendon integrity and tension. When the wrist is in palmar flexion, the flexors to the fingers are relatively lax, and the extensors are relatively tight; the relative tendon tensions are reversed when the wrist is dorsiflexed.
    By allowing the wrist to fall into palmarflexion, the fingers can be seen to extend through tenodesis due to relative tensioning of the finger extensors.

    When the wrist is held into dorsiflexion, relative tensioning of the flexors will cause the digits to flex.
    You can see that the little finger sits more extended than the other fingers; this is termed “out of cascade” (cascade referring to the normal progressively slight increase in finger flexion seen as you move across the hand from the index-middle-ring-little finger).
    This is intentional to allow for the inevitable slight creep that will arise at the tendon junction site while healing occurs. I like the reconstructed tendon to sit approximately as far out of cascade in the “wrong” direction (extension) as it would normally sit in increased flexion.

    Having confirmed satisfactory relative tension, complete the tendon reconstructionI wrap the remaining length of the EDM tendon stump around the EDC to ring finger, securing each rotation of the tendon (i.e., stitching the two tendons together each time the stump passes across the dorsum of the ring finger tendon).
    In this way there will be a broad surface area for tendon-to-tendon healing.
    You may be familiar with techniques that weave the tendons to-and-fro (such as the Pulvertaft weave). I find the wrap technique quicker and easier to perform, but like to make one weaving pass at the outset as it enables me to test the transferred tendon’s position/tension more reliably.

    The arthritic ulnar head is already exposed and can now be addressed by removing the rim osteophyte and bone distally to level the heights of the ulna and radius, if neededNote the eburnated surface of the ulnar head, with relatively sharp marginal osteophytes (O); the sharp edge is what has eroded through the DRUJ capsule and the EDM tendon, causing tenosynovitis which in turn is thought to drive rupturing of the EDC tendons, usually in an ulnar-to-radial direction.

    Decide how much of the ulnar head bone to remove to achieve appropriate relative heights of the ulna and radiusWhile resection of the ulnar head at the level of the neck can be performed (the Darrach procedure), this increases the risk of instability between the distal ulna and radius. Replacing the ulnar head is an option, but excision arthroplasty avoids the need for implant use, and so the potential for a revision operation in the event of wear or loosening.
    The bony resection should look to achieve appropriate relative lengths of the radius and ulna in order to address any ulno-carpal abutment that may be occurring if the ulna is relatively long, and to leave the debrided ulnar head “matching” the shape of the sigmoid notch of the radius.
    In this picture I am using a sharp osteotome (O) to remove a wafer of bone (W) from the distal end of the ulnar head, to leave the ulna at least 2mm shorter than the radius articular surface (judged at the distal end of the sigmoid notch of the radius with the forearm in neutral rotation); the bone is often, but in OA not always, be soft so you may be able to use bone nibblers instead. I find using an osteotome for this step gives a cleaner cut; by removing the subchondral bone distally, you also expose the junction of the cancellous and subchondral bone on the longitudinal aspect of the head, which allows for more easy use of a bone nibbler to contour the head.

    Contour the ulnar head to match the shape of the sigmoid notch of the radiusI find using a bone nibbler (B) the easiest way to remove the ulnar head bone as the curved shape of the jaws of the instrument create a good contour in both the distal-to-proximal and the palmar-to-dorsal planes.
    I work down along the joint line (J- visible between the jaws of the nibbler) from distal to proximal initially, then work around onto the palmar surface, having achieved the shape that I want on the visible dorsal side; this lets be use the instrument to carry the contour round onto the hidden palmar side of the ulnar head.
    Using an instrument (L) to lever the ulnar head (U) dorsally makes the ulnar head contouring easier.
    Having already removed the distal end of the ulna, bone nibblers can be used in most cases even in patients with sclerotic bone from OA.

    To pass sutures through the palmar tissues while interposing the capsular flap into the DRUJ, the needle may need customisingThe radius of curvature of most stronger sutures (3/0 or bigger) tends to be too large to allow you to pass sutures through the palmar capsule; you can see the relative size of the needle in relation to the arthrotomy size. Bending the needle carefully to make a J-shape will make it a lot easier to pass the suture through the palmar tissues.

    Hold the pointed end of the needle with the forceps at least 3-4mm from the tips and bend at the suture end.Don’t old the needle near its tip as this may weaken the tip, making it more likely to break off.
    Don’t press on the tip end or you may well give yourself a needlestick injury!
    Apply gentle but firm pressure to reduce the radius of curvature, moving the point where your needle-holder is grasping the needle to create a continuous J-shaped curve.

    The shape of the needle is now much better suited to pass sutures through tissues at the bottom of the joint cavityThis will enable you to select a suture with better strength to hold the capsular flap into the jointline.

    Pass the suture through the palmar capsule of the DRUJ.The forceps are pushing the resected ulnar head away from the radius to reveal and tension the palmar capsule, so bringing it up towards you; this makes it easier to pass the needle to take a bite as far radial as possible.

    The suture can then be passed through the dorsal flap of DRUJ capsule.

    Tying off the suture will parachute the capsular flap into the joint cavity to interpose tissue into the joint lineThis provides an initial interposition while scar tissues form in the cavity and over the resected ulnar head.

    Suture the retinaculum to reconstruct the dorsal capsule of the DRUJI have passed the suture through the retinacular flap close to the margin, making it ready to reattach to the ulnar head and so to reconstruct the dorsal capsuls of the DRUJ.
    If the retinacular attachment to the radius is insecure, repairing the radial attachment may be necessary in order to recreate a joint capsule, although if you have been careful when windowing the ulnar side of the 4th dorsal compartment to inspect the tendons, the attachment should still be secure.
    If needs be, pass a suture anchor into the radius at the margin of the sigmoid notch to reattach the retinaculum.

    Select the point of attachment of the retinaculum to the ulnar head in order to achieve adequate tension in the dorsal DRUJ neo-capsule (retinaculum)By passing the retinaculum to the sheath of ECU, the tension will be increased; remember that the tension will reduce with supination and increase with pronation (as is the case normally for the DRUJ capsule), so check the range of forearm rotation motion while inspecting the re-attached retinaculum after siting the first suture to check the tension is as you want it.

    The joint and tendons should now be supported and stabilised by the retinacular repair

    Close the woundI use a 2-layer technique, first anchoring the apices (points) of the flaps with buried stitches (I use Vicryl Rapide, but any absorbable suture would be reasonable), then using as few buried sutures as are needed to oppose the skin edges. I then close the skin with a continuous intra-dermal suture using an absorbable monofilament without any knots, looking to remove it at 2-3 weeks once the wound is healed, but with the option of trimming the free ends if the suture does not pull easily through; I find if absorbable suture ends are routinely cut flush with the skin, there is a tendency for cutaneous reactions to arise at the point where the suture passes through the skin.

    Having applied Steristrips to support the wound, I use a waterproof dressing

    Immobilise the forearm with a sugar tong splintBy passing a slab of plaster up the palmar aspect of the hand and forearm, looping it around the back of the elbow, and then down the dorsal aspect of the forearm and hand, the plaster will limit forearm rotation; passing the palmar plaster to beyond the tips of the fingers will also support the tendon reconstruction until hand therapy input can be arranged to fashion a thermoplastic splint and instruct the patient upon appropriate controlled active mobilisation exercises.
    I vary the duration of restriction of forearm rotation depending upon the quality of the tissues, and the reliability of the patient for compliance with post-operative instructions.
    Remember that this patient had a simultaneous elbow replacement, hence the patient is in a lateral position; usually the procedure will be undertaken supine with the arm on a hand table.

    Post Operative

    I modify the precise protocol according to the patient’s functional demands, skin condition and general tissue quality; while stronger tissues seem to be more likely to withstand earlier mobilisation, paradoxically the low functional demands and intolerance of patients with more sever inflammatory diseases often makes me happier to allow early conversion to a removable splint in these patients.
    After surgery, I instruct patients to elevate the hand (using a sling is often harder than you might imagine if they have a sugar-tong splint, as the plaster will restrict elbow flexion) and mobilise the elbow (as far as possible within the confines of the splint) and shoulder to minimise stiffness. The extensor reconstruction will determine mobilisation of the digits; the tendon anastomosis will usually tolerate a controlled active mobilisation protocol (as for extensor tendon repairs), but if the reconstruction is for an isolated loss of EDM, I will allow earlier weaning if the patient understands and accepts the risks to the EDM reconstruction (i.e., if loaded, it may come adrift, although this may well not affect composite extension if their pre-operative function was good). I am more cautious if a tendon transfer was needed.
    I arrange for conversion of the cast to a removable splint (again, a sugar-tong splint or removable equivalent cast) at or around 2 weeks, with wound check, and start weaning at between 2 and 6 weeks (depending upon the extensor reconstruction, as outlined above), with splint removal for skin care in all patients but motion resumption based upon the hand therapists’ assessment of the patient’s understanding of instructions (to be slow and progressive in regaining motion, being limited by pain) and the tissue quality.
    From 6 weeks I allow all patients to discard the splint as they feel confident, converting those who the therapists are concerned about to a forearm-based extension splint for the tendon reconstruction.

    Recommended Reading

    Most patients are pleased with both the restoration of ability to extend their digits (loss of which can cause a surprising degree of functional impairment) and improvement in pain and restriction of DRUJ / forearm motion (although not all patients will have had intrusive prodromal symptoms from the DRUJ). The improvements are usually sustained, and it is unusual to see further problems with the tendons, or problems with symptomatic radio-ulnar convergence or DRUJ instability.
    The papers below will give you further insights into the condition and the technique:
    Bowers, WH (1985) J Hand Surg Am 10:169-178 “Distal radioulnar joint arthroplasty: the hemiresection-interposition technique”.
    This describes the results of the Bowers hemiresection-interposition arthroplasty technique in 38 patients followed for an average of 2.5 years, with painless forearm rotation over a stable arc from 84degrees pronation to 77 degrees supination restored in 85%, with mild pain and an arc of 70 degrees pronation, 75 degrees supination in the remaining 15%.
    Bain, GI et al (1995) J Hand Surg Am 20944-950 “Matched hemiresection interposition arthroplasty of the distal radioulnar joint”
    This independent series followed 49 patients for an average of 3 years, noting pain improvement in 35 and satisfaction in 41 (84%), with improvements in both supination and pronation ranges (to an average of 72 degrees in each direction), but with reported difficulties when turning large objects. The authors felt the need for pain relief to be the main indication for surgery as pain relief was the primary determinant of patient satisfaction.
    Carr, AJ & Burge, PD (1992) J Hand Surg Br 17:694-696 “Rupture of extensor tendons due to osteoarthritis of the distal radio-ulnar joint”.
    This reports extensor tendon ruptures in 12 patients with osteoarthritis, rather than inflammatory arthritis, 10 of whom did not have prodromal symptoms, and identifies the capsular perforation and contribution of attrition from the ulnar head osteophyte.

    Reference

    • orthoracle.com

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