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Total Hip replacement- Cemented Exeter-Contemporary (Stryker) by a posterior approach

    Overview

    Learn the Total Hip replacement: Cemented Exeter/Contemporary (Stryker) by a posterior approach surgical technique with step by step instructions on OrthOracle. Our e-learning platform contains high resolution images and a certified CME of the Total Hip replacement: Cemented Exeter/Contemporary (Stryker) by a posterior approach surgical procedure.
    A cemented total hip replacement should be considered in the elderly population. It is forgiving to the ageing skeleton which is reflected in the fact that there is a lower risk of fracture of both the acetabular and femoral bone when compared to uncemented designs.
    The Exeter cemented stem has excellent survivorship, reported as 100% at 17 years (Carrington et al), and is a polished, double tapered cemented stem which has an ODEP* 13A star rating.
    The contemporary cup has excellent survival (Magges et al). Options for both a ceramic or metal head are available and where possible a 32mm head is favoured to reduce dislocation rates.


    Indications

    INDICATIONS
    Osteoarthritis, rheumatoid arthritis, osteonecrosis, metastatic cancer (lesions confined to the femoral head), Intracapsular fracture of the femoral neck.
    SYMPTOMS & EXAMINATION
    Osteoarthritis pain is characteristically felt in the groin and buttock, pain may radiate down to the knee, pain is made worse with exercise and relieved with rest, pain causes a decreased walking distance and speed and the patient often complains of pain at night. Symptoms of stiffness – manifest as difficulty getting down to feet. Examination findings include a stiff hip with decreased range of motion, pain throughout movements, the first movement to go is internal rotation. Leg length descrepancy may be apparent if their is significant collapse of the femoral head.
    IMAGING
    Plain antero-posterior pelvic and lateral radiograph of the effected hip.
    ALTERNATIVE OPERATIVE TREATMENT
    Consider (very rarely) Girdlestones procedure if patient non-ambulatory and high risk of surgical complications with pain from an arthritic hip joint.
    NON-OPERATIVE MANAGEMENT
    Conservative treatment strategies, weight loss, exercise, walking aids and analgesia.
    CONTRAINDICATIONS
    Active infection, leg ulceration.

    Setup

    General anaesthesia
    lateral position
    IV antibiotics half an hour prior to knife to skin
    tranexamic acid
    Contralateral limb TED stocking and mechanical calf pump.
    Prep skin with 2% Chlorhexidine
    Drapes

    Operation – 1

    Position the patient in the lateral position.
    A bolster applied over their sacral lumbar junction as seen in the picture. The lower limb has a TED stocking and a Flowtron around the calf. There is a prop placed anteriorly on the anterior superior iliac spine. The aim is to position the pelvis in a perpendicular position to the flat operating table. The uppermost anterior superior iliac spine should be positioned exactly above the lowermost anterior superior Iliac spine (ASIS). Note the leg to be operated upon is marked.

    Pre-operatively test of the stiffness of the hip.
    The hip here has been put in to internal rotation. Rotate the leg internally until it reaches its maximal rotation. If the angle of internal rotation is low the chances of dislocation are much less.

    Check the patient’s leg lengths once they are stably positioned on the table.Make sure to abduct the leg to get a true reflection of the leg length. It is important to check the patient’s leg lengths when they are supine prior to positioning as well to get a more accurate idea of their clinical picture. Compare the clinical leg lengths to the radiographs, a shortened limb might indicate femoral head collapse, or significant intrusion into the acetabulum.

    AP radiograph, showing pre-operative diagnosis of osteoarthritis.

    Pre-operative templating. In this case we know the sizes of the previously operated otherside which it is most likely to be again.
    Computerised templating. Use the radiograph in conjunction with your clinical findings to assess leg length and plan your mechanical reconstruction. Template for cup size and orientation, template for femoral stem size, offset and leg length.

    2% Chlorhexidine prep has been applied to the skin and an Ioban preparatory skin drape (Iodine impregnated) has been applied to the thigh.
    The incision has been marked on the patient and is centred over the tip of the greater trochanter, distally the incision is straight in line with the vastus lateralis fibres and proximally the incision curves towards the posterior iliosacral joint.

    The skin incision is centred over the tip of the greater trochanter, distally the incision is straight in line with the vastus lateralis fibres and proximally the incision curves towards the posterior iliosacral joint.Cut perpendicular to the skin, if the dermis is not cut perpendicular the skin edges are harder to close.

    The fascia lata is identified beneath the fat and a fasciotomy is made with the scalpel

    The fascia lata is then opened with the use of dissecting scissors both distally and proximally (as shown) in the line of the skin incision. Proximally the fibres of gluteus maximus are split in the direction of its fibres using blunt dissection.

    A Charnley Bow retractor is applied with an anterior curved leaf under the anterior fascia lata. Posteriorly a “squared” leaf of the retractor is applied under the posterior edge of the fascia lata.Take care not to catch and damage the sciatic nerve by delving deeply and blindly with the retractor.
    The sciatic nerve exits the pelvis through the lower part of the sciatic notch. It is particularly at risk during the posterior approach to the hip. Identify the nerve at this point to identify where it is before proceeding, if it looks small it may of divided into its tibial and common peroneal branches before piriformis. The nerve appears below the piriformis muscle and lies over superior gemellus, obturator internus, inferior gemellus and finally the ischial spine.

    The sciatic nerve (S) exits the pelvis through the lower part of the sciatic notch. It is particularly at risk during the posterior approach to the hip. Identify the nerve at this point to identify where it is before proceeding, if it looks small it may of divided into its tibial and common peroneal branches before piriformis. The nerve appears below the piriformis muscle and lies over superior gemellus, obturator internus, inferior gemellus and finally the ischial spine.
    (This image has been taken from another case)

    Remove the trochanteric bursa and fat off the back of the greater trochanter to expose the piriformis tendon and short external rotators.In this photograph we have a Langenbach (L) retractor holding the gluteal musculature. Internally rotate the femur to lengthen the tendon and aid identification. The sciatic nerve is not visible in this slide.

    The piriformis tendon is identified as shown. The piriformis tendon can be found by palpating the greater trochanter and when you feel a small “nipple” of bone the tendon is adjacent to this.
    Once the fat is swept/dissected off the tendon it is readily seen. An incision is made in line with the piriformis tendon over its superior border.

    Position a Hohmann retractor superior to piriformis and locate its tip into a small incision made next to the tendon.A blunt Hohmann is placed superior to the piriformis tendon placed in the incision made in step 11. To achieve this pass curved dissecting scissors into the incision you have made with them superior to the piriformis tendon next place the Hohmann retractor over the scissors into the same space, then remove the scissors.

    A distal Hohmann retractor is placed in the space between the joint capsule superiorly and the quadratus femoris muscle inferiorly.To insert the distal Hohmann (D) retractor use the curved dissecting scissors to enter the space between the joint capsule superiorly and the quadratus femoris muscle inferiorly. A blunt Hohmann is then placed in the same tract made by the scissors and the scissors are then removed in essence swapping the Hohmann retractor for the scissors. Always be careful not to damage the sciatic nerve. The superior Hokmann (S) retractor remains in place,

    Place a stay suture in the piriformis tendon.A 2 Vicryl stay suture is applied to the piriformis tendon using 2 “throws” of the suture into the tendon as close to its insertion on the greater trochanter as possible. Maintain as much length of the tendon as you can.
    The priformis tendon is now released from its distal insertion on the greater trochanter, control of the tendon is achieved by tension placed on the stay suture.
    Now an arthrotomy is made as an L-shaped limb starting proximally at the edge of the acetabulum heading towards the tip of the greater trochanter, the arthrotomy is then continued distally along the edge femoral neck until the quadratus femoris muscle is reached. Inferiorly and distally there is often a venous vessel which bleeds – this will require diathermy.

    A second stay suture is now applied to the joint capsule along its free edge after the arthrotomy has been performed.
    Using the two stay sutures that are now in place reflect the tissues posteriorly to protect the sciatic nerve throughout the rest of the operation. Second stay suture (S).

    Dislocate the hip by internally rotating it as it is adducted over the lower limb.The femoral head has been dislocated. The head is marked with annotation F.

    If a protrusio case it may be prudent to cut the femoral neck in-situ prior to dislocation.
    If there are excessive osteophytes posteriorly sometimes it is necessary to remove the osteophyte rim from the posterior acetabulum wall with an osteotome first.
    Both these manoeuvres are there to prevent fracture of the femur or posterior acetabular wall during the dislocation manoeuvre. In this case the femoral head was easy to dislocate.

    Remove the remnants of the piriformis tendon in the piriformis fossa on the greater trochanter and incise the anterior capsule along the femoral neck under quadratus femoris (Q).This aids femoral neck visualisation. This release aids femoral head exposure by allowing increased rotation of the femur.

    An osteotomy is made with the sagittal saw at the level of the neck cut as per pre-operative templating and the femoral head is removed.Measure up from the lesser trochanter to your planned resection level. Angle the saw blade so that its edge doesn’t cut into the greater trochanter.

    Remove the femoral head with a wide osteotome.

    Femoral neck post osteotomy. The piriformis fossa is annotated P.

    A retractor is now placed anteriorly on the acetabular margin to mobilise the femur anteriorly and out of the way of the acetabulum, following removal of the femoral head.Place the retractor at about 10 o’clock on left and 2 o’clock on a right sided hip replacement.
    The labrum and soft tissues are shown being excised around the acetabular margin to expose the acetabulum 360o. Sometimes you might need to release the reflected head of rectus femoris to allow the femur to mobilise forward to gain better exposure of the acetabulum. The reflected head is extra-articular on the superior and anterior margin of the acetabulum – release the fibres by sharp dissection onto the bone.
    The transverse acetabular ligament is identified. This is a valuable landmark for cup positioning (Archibold et al’s paper (J Bone Joint Surg Br. 2006 Jul;88(7):883-6.). Aligning your acetabular component with the transverse acetabular ligament seems to be the optimal cup position for specifically reducing dislocation rates (0.6%).

    The view of the acetabulum from anterior side of patient once the labrum has been excised.

    A Judd pin is inserted in to the ischium.To insert this Judd pin place the tip of the pin inside the acetabulum gradually walk it back until you go over the acetabulum margin posteriorly in the space before the short external rotators are and then aiming for the ischium hammer the pin insitu this acts as a retractor.

    Operation – 2

    A superior Judd is placed into the ilium proximal to the acetabulum. Use the tip of the pin to go superior to the acetabulum under the gluteal musculature aiming to retract the gluteal muscles with the pin once it has been hammered into the ilium.

    A retractor is placed under the transverse acetabular ligament inferiorly, which is located inferiorly in the acetabulum.This is a valuable landmark for cup positioning (reference 1). Aligning your acetabular component with the transverse acetabular ligament seems to be the optimal cup position for specifically reducing dislocation rates (0.6%).

    Ream the acetabulum with the reamer aligned with the transverse acetabular ligament and an abduction angle of 45 degrees.Reaming starts after the foveal ligament remnants have been excised. In the base of the acetabulum the first reamer is used to remove the sclerotic bone and remnants of cartilage in the foveal fossa. Subsequent reamers are used to widen the acetabulum until good cancellous bleeding bone is seen circumferentially in the remaining acetabular bone.

    View of reamed acetabulum from the anterior aspect of patient. Ream the acetabulum until you have exposed bleeding cancellous bone, typically the final sized reamer is 6mm wider than the patients femoral head.

    Ream the acetabulum in 2mm increments, ensuring that the posterior and anterior walls are not over reamed. Once cancellous bone is visible and the subchondral bone has been reamed away (except the medial floor) stop. Be careful not to ream through the medial floor in any acetabular preparation as you will enter the pelvis.

    Use the acetabular step drill to drill multiple keyholes into the circumference of the acetabulum – this allows for optimal cementation.Care being taken not to go through the medial wall. The medial floor is the thinnest area and it would be perforated by this drill. The acetabulum should look like a watering can head with the number of keyholes made.

    How to choose a cup size;
    Use a cup identical or 2mm samller than the last acetabular reamer used. The cups range from 44mm to 60mm in 2mm increments. Different inner diameters are available 22.2mm, 26mm, 28mm and 32mm.

    The flange has reference lines of 2mm, 3mm, 5mm, 10mm and 15mm. Cut the flange to fit the patients acetabulum.A trial flange exists and can be used to cut the shape of the desired flange. The trial flange once cut to the desired shape can be overlied onto the real cup and the flange of the cup cut to the trail flange shape. Most surgeons once experienced go straight to cutting the cup and omit this step.

    The contemporary cup has 4 cement spacers (s) attached to its undersurface. These prevent the cup from bottoming out and allow for a minimum cement mantle thickness.

    A trial reduction of the cup is made aiming for anteversion of 15 to 20 degrees and an inclination angle of 45 degrees.Trial reduction of the cup in to socket. Ensuring that the cup is aligned with the transverse acetabular ligament and the cup is not open.
    The anterversion of the cup should be about 15 to 20 degrees – this is typically the orientation of the transverse acetabular ligament (TAL). If a native acetabulum is retroverted do not use the TAL as a guide. Also aiming for an inclination angle of approximately 45o this is guided by the handle which should be parallel to the floor of the operating room. Check that the flange covers any defect superiorly and furthermore check that no further rim of the cup needs to be excised.

    The acetabulum has been lavaged with pulsatile chlorhexidine and is now being dried with a dry swab in the acetabulum and sucker in the base of the socket. Some surgeons use a suction catheter implanted in to the patient’s ilium to allow the cement to be sucked further in to the cancellous bone during cementation. This has not been used in this case.

    The acetabulum is washed and dried and high viscosity cement applied to the socket.Once the high viscosity cement(Palacos) has been vacuum mixed it is placed in to the acetabulum at 2 minutes 15 seconds. One mix of cement is typically enough to fill the socket. Any blood is now removed off the visible cement at this stage with a dry swab.

    The cement is pressurised using the rubberised pressuriser until approximately 3 minutes and 30 seconds after the cement mixing started and the definitive acetabulum is implanted.

    The image shows the acetabular component mounted prior to being compressed into the acetabular cement. Place the leading edge of the cup inferiorly into the cement mantle, once it is seated below the TAL close the acetabular component into the cement mantle – do this by using the pusher instrument to close the cup. Whilst this is occuring ensure correct alignment with the TAL by “steering” the introducer to the correct position. Once the cup is closed removed the introducing handle.

    Confirm you are happy with the cups position in relationship to the TAL and cup abduction angle.

    Any cement that escapes needs to be removed, do this whilst it is still soft.

    Until the cement has fully cured pressure is applied to the acetabular component using the appropriately sized head.The head diameter used is determined by the inner diameter of the cup and attached to the rod shown.
    The commonest diameter head sizes used are 28mm and 32mm. Each of these has variable offset sizes, -4mm,0mm,+4mm and +8mm.

    Remove the Judd pins and and place a protective swab into the acetabular component to protect it from scratches during the rest of the procedure.
    Rotate the femur into view, by internally rotating the femur. Place a Muller retractor under the femoral neck medially, at the level of the lesser trochanter, don’t drag soft tissues into the retractor, keep the prongs of the Muller retractor close to bone.

    A box chisel is utilised to start the femoral canal preparation.Resect any remaining soft tissue from the piriform fossa. Aiming from the starting in the piriformis fossa and dialling in the version of the stem you wish in the canal proximally. Use the box chisel to remove the metaphyseal bone remaining proximally.

    In this slide the box chisel osteotomy site is seen,note the forceps showing the crucial entry point in the pirifirmis fossa. This point is the reference point for entry into the femur. It allows for the stem to be placed centrally down the femoral canal in both the ap and lateral planes.

    Second stage of canal preparation is to use the pencil reamer.You will know you are in the correct place as the pencil reamer will easily follow a correct path of least resistance in most typical femoral canals.
    The previous entry point with the box osteotome ensures you will be correct in the lateral position and pencil reamer will pass easily. If the pencil reamer does not pass easily, you may have started in a poor position, the patient may have a tight femoral canal or there maybe an overhanging trochanter.

    Use serial broaching to prepare the femoral canal, starting with an Exeter 37.5 stem 0.Smaller patients can start with the 35.5 broach.
    Hammer the broach into the femoral canal, only a small amount of force is needed, excessive force risks fracture. Start small and then increase the broach size as needed.
    Ensure the serial broaches used are placed in the correct version for the patients femoral canal. Aiming for 15 to 20 degrees anteversion. Keep going with the increasing broach sizes until they fill the femoral canal. Use the broach size that corresponds to the broach size you have templated.

    Final position of Exeter stem broach in femoral canal.
    Ensure the centre of rotation of the femoral stem replicates the natural centre of rotation of the patients femoral head by inserting the stem to the correct length and using the correct offset stem.

    A 32mm plus 0 head trial head is applied to the Exeter stem and a trial reduction undertaken.

    The hip has now been reduced. Test the hip for stability.
    See the Exeter/Gap cage II technique on OrthOracle for description and pictures of stability testing:
    Exeter stem (Stryker) and Gap II restoration acetabular cage (Stryker) for acetabular metastases.

    Operation – 3

    Confirm the height of the broach to the femoral neck cut, the holes in the broach act as a marker.Each hole (3) on the broach correlates to a line on the definitive stem (3). These lines are 5mm apart.

    A Hardinge cement restrictor is now inserted down the femoral canal to 16cm depth (Exeter canal restrictors are an alternative)I am now happy with the hip in terms of its stability and leg length and therefore can finish the femoral preparation.
    I prefer the one sized Hardinge cement restrictor. You may trim the Hardinge restrictor, however I only ever consider trimming in the tightest of femoral canals.

    The femoral canal is lavaged with a pulsatile long nozzeled jet and suction applied to remove loose bone, debris, blood and fat.

    A suction catheter is the inserted down the femoral canal.

    The femoral canal is then packed with a rolled swab.This occurs while the cement is being mixed by the scrub team.

    Exeter stem mounted on its introducing handle.
    The markings (M) on the proximal stem correlate to the markings on the broach to allow for accurate placement of the stem in the cement mantle to same depth as the broach was inserted during trialling.
    Note the plastic protector on its trunnion and distal centraliser. Two centralisers exist and come in the stem’s packet, one has 3 flutes and one is unfluted (as shown)- this should be used in narrow femoral canals.
    The Exeter stems are 150mm long and have offsets of 37.5mm, 44mm, 50mm and 56mm. In each offset range their are differing sizes ranging from 0 through to 4 for the 37.5mm stem, 0 to 6 for the 44mm stem, 1 to 5 for the 50mm stem and 1-2 for the 56mm offset stem. (Smaller stem sizes are available 30,33 and 35.5mm). It is a modular stem with differing head size options available.
    Note the distal centraliser on the femoral stem.

    Cementation of the femoral canal.The cement is applied in a distal to proximal direction after 2 minutes and 15 seconds from the start of mixing. Place your nozzle of your cement gun down the femoral canal withdraw to approximately 1cm prior to instilling cement this allows blood pooling distally to be sucked up. Instil the cement and ride it almost like a surf wave allowing the canal to fill from distal to proximal, whilst leaving the suction catheter in situ.

    Cut the tube of your cement gun off and follow with pressurisation of the cement in the femoral canal.Pressurise the canal with one movement of the gun handle and then remove the venting tube whilst pressuring. Allow pressurisation up to 3 minutes and 15 seconds.

    The appearance of cement after pressurisation, filling the femoral canal.
    The forceps show the correct entry point of the femoral stem.
    If you go to the posterolateral corner as identified you will allow your stem to be perfectly positioned in the AP and lateral projections.

    The Exeter stem is inserted in to the cement at 3 minutes 15 seconds starting at posterolateral corner of the canal with the tip of the implant.This will allow you to have the stem in correct AP and lateral alignment. Insert the stem in the same version and depth as per trialling.
    Once the cement has cured remove the stem holder.

    Drill two holes into the greater trochanter for the posterior repair. Make the two drill holes, one at the level of the tip of the greater trochanter and the second at the level of the piriformis fossa. The stay sutures are pulled through two greater trochanteric drill holes. Place the superior limbs of the two stay sutures through the superior hole and then the same for the inferior sutures.

    Stay sutures are pulled through the trochanteric drill holes.The stay sutures from steps 15 and 16 are pulled through the two drill holes, such that the superior 2 stay suture ends are pulled through the superior drill hole. Inferior sutures are lulled through the inferior drill hole.

    Place a clip on the stay sutures to ensure they are not pulled back through the two drill holes when you reduce the hip.

    Place the same trial head (32+0mm) on the stem. Repeat your tests of stability to ensure the hip joint is as stable as when tested with the broach earlier.Confirm you are happy with the head size. At this point a 32 -4mm, 32+ 0mm, 32+4mm and a 32+8mm head can be trialled.
    Rarely should you need to change the head size that you were happier with earlier in the procedure, but if there has been any variation in the stem version, length, or medial/lateral position in the cement mantle a change maybe required to optimise the hips stability.

    Clean and dry the trunnion.

    Apply and carefully impact the definitive femoral head to the cleaned and dried trunnion and reduce the hip.Apply the head with a gentle twisting motion to obtain optimal engagement, ensuring no soft tissue gets interposed between the head and the trunnion. Use one hammer blow to fully seat the femoral head on the trunnion, once it has been applied by hand.

    Pull the stay sutures taught and ensure the posterior structures return to the greater trochanter in a natural position.Tie the two stay sutures together over the small boney bridge between the two drill holes. Hold the leg with the knee elevated whilst tying the sutures.

    The wound is carefully closed in layers.Heavy prolene suture have been used to close the fascia lata.

    The fat layer is now closed with continuous 0 vicyl.

    The skin is now closed using a 2/0 quill subcuticular suture running in the dermal layer and then returning back in the skin layer.

    Tissue glue applied to the wound edges.

    Steristrips applied to the wound.

    Dressing applied.

    Post-operative AP Radiograph.
    It is important to look for the following features.
    Cement mantle around acetabular component
    Cement mantle around femoral component
    Leg length compare heights of lesser trochanters
    Offest of construct

    Lateral post-operative radiograph.

    Operation – 4
    Post Operative

    Full weightbearing
    24 hours iv antibiotics
    Clexane 40mg s.c 12 hours postop continued for 28 days
    Bilateral foot pumps
    Abduction wedge first night postop
    Check AP and Lateral radiograph
    Full weightbear once radiograph reviewed
    Wound check 2 weeks

    Recommended Reading


    Archibold et al’s paper (J Bone Joint Surg Br. 2006 Jul;88(7):883-6.)
    Classic paper from Mr David Beverland, Belfast, UK. A 1000 cases had their acetabular components orientated to be aligned with the transverse acetabular ligament. A dislocation rate of 0.6% was seen. This seminal paper changed orthopaedic practice, allowing for cups to be less retroverted once the technique was adopted. The transverse acetabular ligament is readily identifiable in the vast majority of cases.

    Carrington et al. J Bone Joint Surg Br. 2009 Jun;91(6):730-7. doi: 10.1302/0301-620X.91B6.21627.
    The first 325 Exeter Universal stems (309 patients) implanted at the originating
    centre were inserted between March 1988 and February 1990. With an endpoint
    of revision for aseptic loosening, the survivorship at 17 years was 100% and
    90.4% for the femoral and acetabular component, respectively. Radiological review showed excellent preservation of bone stock in the proximal femur and no failures of the femoral component.

    Maggs et al. Bone Joint J. 2016 Mar;98-B(3):307-12.
    This study reviewed 203 hips in 194 patients. 129 hips in 122 patients are
    still in situ. There were no acetabular component revisions for aseptic loosening. Kaplan-Meier survivorship, with revision for aseptic loosening as the
    endpoint, was 100% at 12.5 years and for all causes was 97.8%.

    Reference

    • orthoracle.com

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