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Friday, 18 May 2012 00:00

Surgical Procedure 3D Overview

The implantation of the OGAP-OPL is performed in either a single surgery or over two stages depending on the patients existing conditions and suitability.

As no two osseointegration patients are identical, the surgical process will vary slightly from patient to patient depending on their condition and needs.

The first stage will generally involve:

The soft tissue is managed and redundant skin and soft tissue fat are removed in order to minimise the bone to skin distance. This leads to a reduced chance of complications. The muscle groups are rearranged to serve a functional purpose in operating the leg and the soft tissue facial layer is reorganised around the stem.
The bone residuum is reshaped and any bone spurs are removed.
The bone canal is prepared using a specialised instrument. The internal component of the implant is press fitted into the bone canal securing early stability and future bone ingrowth.
If there is a neuroma causing nerve pain the nerves involved will be addressed surgically by excision of the painful neuroma and deep positioning of the residual nerve into the muscle group to minimise future nerve issues.
The stump is refashioned in a cosmetic manner and the wound is closed in layers.

A period of six to eight weeks takes place after the first stage to allow for osseointegration. This is then followed by the second stage.

Involved in the second stage surgery is:

The creation of a circular skin opening (the stoma) at the base of the stump. Through this opening the dual cone adaptor is connected to the internal stem, which is already integrated in the bone. The remaining components of the prosthesis can then be attached externally.

If the surgery is performed in a single stage, all of the above will take place during the one procedure.

Partial weight-bearing and the fitting of the lower prosthesis can take place as early as a few days after the second surgery. This is done under careful supervision of the team. It is now that the rehabilitation stage and gait training can begin.

For more information on the post-surgery recovery and rehab process please see Post Surgical Information.

Published in Information

Tuesday, 15 May 2012 00:00

Dislocated Ankle Information

A dislocated ankle is characterised by significant damage and tearing of the connective tissue surrounding the ankle joint with subsequent displacement of the bones forming the joint. When an ankle becomes dislocated the bones no longer fit nicely together and the joint becomes unstable.

The ankle joint is made up of three bones:

Tibia – the shinbone
Fibula – smaller bone of the lower leg
Talus – a small bone that sits between the calcaneus (the heel bone) and the tibia and fibula

The joint is surrounded by strong connective tissue known as the joint capsule as well as several ligaments, which provide additional stability to the joint.

When excessive forces beyond what the ankle can withstand are applied to the joint, tearing of the connective tissue can occur. If the forces are more excessive than what the connective tissue can handle the bones are forced out of their normal position and the ankle becomes dislocated.

Since the forces resulting in an ankle dislocation are excessive, a dislocated ankle is often accompanied by other injuries to the foot and ankle such as fractures.

Causes of Ankle Dislocation:

Twisting or rotating the ankle side to side

Tripping or falling which cause the ankle to roll inwards or outwards

Extreme flexing or extending of the joint

Rapid change in direction particularly seen in sports such as rugby, soccer, basketball, netball and football

Ankle Dislocation Signs and Symptoms

Common signs and symptoms of a dislocated ankle include:

Immediate severe pain at the site of the injury. Pain is usually so intense activity cannot be continued and weight bearing is unbearable

Sensation of ankle ‘moving out’ at time of injury

Swelling

Bruising

Tender to the touch

Unable to put weight through the injured foot

Obvious physical deformity

Loss of movement in ankle

Ankle Dislocation Treatment

An ankle dislocation is confirmed with x-ray. X-ray is also used to assess the severity of the injury and any associated injuries. Further investigative measures may be required such as a MRI or CT scan.

Treatment of ankle dislocations involve the bones being ‘relocated’. This means they are safely pushed back into place. This should only ever be preformed by an experienced medical professional. An ankle relocation should never be attempted alone as serious long term damage can occur to the structures around the ankle such as the nerves, blood vessels, bones, ligaments and cartilage if the ankle relocation is not performed correctly.

During the procedure the bones are first reduced (repositioned) into their normal alignment. The bones are then positioned and held together by a plate attached to the outer bone using pins and screws. In some cases a screw or rod inserted into the bone may be used to keep the bone fragments together while they heal.

Following surgery a physiotherapy rehabilitation program is prescribed to strengthen the joint and restore it to optimal movement and function. A patient’s recovery after surgery is largely determined by their commitment to their physiotherapy program.

Many patients who suffer a dislocated ankle are able to return to normal function post surgery. This may take weeks to months depending on the severity of the injury. However, due to the connective tissue damage associated with this injury there can be an increased likelihood of future dislocation or ankle sprain. In the case of recurrent ankle dislocation further surgery may be required to increase the ankle’s stability.

Published in Information

Tuesday, 15 May 2012 00:00

Hip Dysplasia

Bony Abnormality

Dysplastic hips share a common pattern of anatomic abnormalities. In hip dysplasia the deficiency is mainly on the acetabular side. Occasionally the whole pelvis is underdeveloped.

The acetabulum (socket of hip joint) is usually shallow; deficient anteriorly and superiorly with a decreased antero-posterior diameter and antiverted.

The Femoral side (thigh bone) shows persistent femoral anteversion, valgus neck, hypoplastic, narrow canal, small and posteriorly placed greater trochanter.

The combination of these abnormalities leads to a significant reduction in the contact area between the femoral head and acetabulum, the 'ball' doesn't fit snugly in the 'socket' of the hip joint. As a result, high forces are transmitted through a limited surface area and the increased and uneven loading of the joint results in articular degenerative changes and eventually osteoarthritis.

Soft-tissue Abnormalities

These are usually associated with proximal migration of the femur. These include hypoplastic, short muscles acting on the hip joint, thickened joint capsule, femoral nerve displacement proximally and laterally as well as sciatic nerve shortening.

Clinical Manifestation and Symptoms

Patients with dysplasia typically experience groin pain that increases with exercise. Other features such as catching, locking and giving way of the hip are symptoms that may indicate associated labral tear or articular cartilage pathology.

Diagnosis is made by plain radiograph (x-ray). Different classification systems are used to assess the severity of the condition and help to choose the best method of treatment.

Classification of Dysplasia

Hartofilikadis classification. This classification is reasonably simple:

Type 1: The hip is Dysplastic but the femoral head remains in the true acetabulum. The femoral head centre and the acetabular edge angle is less than 20 degrees.

Type 2: Described as low hip dislocate where the femoral head articulates in a false acetabulum and the inferior lip overlaps the true acetabulum.

Type 3: High dislocation where false acetabulum has no contact with the true acetabulum.

Crowe’s classification: Measures proximal migration as a proportion of the height of the femoral head compared to the distance from inter-tear-drop line.

Type 1: Proximal migration < 50% height of head (from the inter-tear-drop line).

Type 2: 50-75% proximal migration.

Type 3: 75-100% proximal migration

Type 4: >100%

Principles of Management

Hip arthritis is the end result of hip dysplasia for which total hip arthroplasty is the procedure of choice for most patients.

However, the anatomic abnormalities associated with the dysplastic hip increase the complexity of hip arthroplasty. In principle it is desirable to restore normal anatomy and use an uncemented implant. In order to restore normal anatomy the metal shell needs to be inserted near the normal anatomical position of the acetabular to restore hip centre of rotation. The uncemented acetabular components allow biologic fixation with potentially improved results compared with cemented cups, especially in young patients.

Due to soft tissue shortening, femoral shortening is required in some cases. This includes the sciatic nerve which it is at most risk if the leg is lengthened by more than four centimetres. Shortening can be achieved by subtrochanteric osteotomy.

The results of total hip arthroplasty for hip dysplasia demonstrates a high rate of pain relief and functional improvement for patients.

Acetabular reconstruction placement of hip centre:

High

Normal

In-between; centralised

Femoral reconstruction has two considerations:

Leg length. Can restore limb length via either restoring hip centre or lengthening the femoral component.

Abnormal femoral anatomy which needs a small implant using a specialised surgical technique.

Approach

Type 1 hips can be reached through a standard posterior approach. For more exposure a trochanteric slide, Chevron or flat osteotomy at the base of the greater trochanter can be used to retract and expose more of the ilium and then reattrached via wires. To assess how deep to ream the approach is to drill through the floor and measure its thickness and then ream to within 0.5-1.cm and insert trial if <70% is covered. Then use the femoral head to create a shelf.

Results

Acetabular component: Has better results with uncemented cups, more native bone coverage and positioning the component as near as to the anatomical hip centre.

Femoral component: Shows cemented femurs perform better than cemented cups. Uncemented femurs show promise in younger patients since uncemented are more biological implants. Subtrochanteric osteotomy has 80% satisfactory results and are better with uncemented implants.

Published in Information

Tuesday, 15 May 2012 00:00

ACL Rupture in Children

Due to the nature of the knee joint, active children are prone to knee injuries. A torn or ruptured anterior cruciate ligament (ACL) is one of the most common type of knee injuries.

Contact sports or sports that involve swift, abrupt movements such as pivoting, stopping suddenly or changing direction quickly are the most common cause of ACL injuries.

An ACL injury can also occur when a child jumps and lands on their feet with knees straight and locked instead of flexed as this puts excessive pressure on the knee joint and can cause the rope like ACL to tear and break apart.

ACL rupture is three times more common in teenage girls than in boys. This is due to:

Oestrogen hormones which lead to weaker collagen

Anatomical tight notch

A wider pelvis which leads to altered mechanics and increases valgus stress on landing from a jump

ACL injuries can be very painful and can cause the child to be unsteady on their feet and have difficulty walking. Depending on the age of the child and the severity of the injury, a torn ACL often requires surgery in addition to physiotherapy.

Symptoms

Pain when bearing weight on the affected leg or at rest
Swelling of the knee joint which can occur within 24 hours of the injury
Most likely there will be some instability when walking and the feeling of being unstable or ‘wobbly’ on the leg as well as the sensation of the knee feeling not as tight or compact as it was previously
Often children will report hearing a ‘pop’ sound which occurs when the ligament tears

If a child has suffered a knee injury they should stop activity immediately and seek medical attention to prevent any further injury to the knee.

In the interim, the knee should be iced regularly for 20 minute intervals. The knee should be elevated as much as possible to reduce swelling. It is advised not to bear weight on the affected leg.

Treatment

Treatment of an ACL rupture in children differs from the standard treatment for an ACP rupture in an adult. A child or adolescent knee varies anatomically and physiologically from an adult knee and thus the treatment needs to reflect these differences.

The main difference is the growth plates or epiphysis in a child’s knee. These are regions at the end of the femur and tibia of developing tissue and account for the majority of the growth of the leg. These sections are usually the weakest part of the knee. The same injury that would tear a ligament or cartilage in a mature knee is much more likely to fracture the bones through the growth plate in a child.

The complication in children undergoing ACL reconstruction, is the growth plates of the knee are directly in the path of where the holes would be surgically drilled in the bone to attach the new ligament. A standard ACL reconstruction in a growing child or adolescent without any consideration for this factor can cause a growth abnormality leading to leg length inequality or to angulatory deformity at the knee. The younger the child, the higher the risk of this occurring.

Thus, non-operative treatment is usually suggested initially. This involves strapping the leg, prescribing strengthening exercises as well as abstaining from activity.

When a child stops growing, the growth plate hardens (ossifies) along with the rest of the bone. Girls tend to stop growing earlier than boys; their growth plates usually close around ages 14 or 15. Boys' growth plates close later, at around 16 or 17.

If the adolescent is close to skeletal maturity, the risks are small and a standard ACL reconstruction is usually performed.

In a younger child alternative techniques have been developed to reduce the possibilities of growth complications. These techniques involve placing the ligament graft in a non-anatomic position or one that does not quite duplicate normal ligament function. This is done by either drilling holes that go around rather than through the growth plates or by avoiding holes altogether and wrapping the graft around the bone. Growth abnormalities can still occur, but the incidence is much less than with standard techniques.

These procedures are designed to be a temporary measure to control symptoms until skeletal maturity, when a traditional reconstruction can be performed. Such interventions have been quite successful, with many children returning to sports and not needing a second procedure later on.

Rehab and Recovery

Recovery from ACL surgery is a lengthy process and physiotherapy is required to restore full range of motion and function of the knee.

A full rehab program complete with daily strengthening exercises will be explained and the child will be on crutches for four to six weeks post surgery.

Published in Information

Monday, 07 May 2012 00:00

Total Hip Replacement (Anterior approach) - 26 hours post surgery

This video demonstrates a patient 26 hours post surgery following a Total Hip Replacement using the Direct Anterior Approach performed by Professor Munjed Al Muderis.

Published in Post Surgery

Monday, 07 May 2012 00:00

Total Knee Replacement - 8 months post surgery

This video demonstrates a patient 8 months post-op after having a Total Knee Replacement as performed by Professor Munjed Al Muderis.

Published in Post Surgery

Tuesday, 01 May 2012 00:00

Hip Arthroscopy Information

Hip arthroscopy is an excellent minimally invasive operation that allows thorough visualization of the hip joint needed for diagnosing and addressing various pathology, inside and outside the hip joint. So far there is no radiographic study that is entirely sensitive or specific enough for the diagnosis of cartilage lesions such as labial tears or chondral damage. Hip arthroscopy is a technically demanding procedure, requiring in depth knowledge and requires specialised training and education.

Indications for hip arthroscopy:

Diagnosis and treatment of labral pathology

Removal of loose and foreign bodies

Osteochondral fragments and cartilage flap lesion

Synovial biopsy or limited synovectomy

Synovial chondromatosis

Wash out of infected joint as in septic arthritis

Evaluation of cartilage quality in avasculara vascular necrosis (AVN) mainly in early stages

Debridement of ruptured or impinging ligamentum tears

Assessment of the joint following fixation of a fracture acetabulum or femoral head

Assessment of a painful hip resurfacing or arthroplasty

Excision of osteophytes such as Ganz bump and acetabular spurs

Excision of impinging synovitis such as in case of collagen disease

Assessment of cartilage condition in dysplastic hip and perthes disease in adolescents

Debridement, joint wash-out and chondral microfractures which may have a role in management of early arthritis especially in younger patients when it is advisable to delay joint replacement surgery as long as possible

Labral Tears

The acetabular labrum is a fibrous rim of cartilage around the hip socket which helps keep the head of the femur (thigh bone) inside the acetabulum (hip socket). It provides stability and seals the joint.

Acetabular labrum tears (labral tears) can cause pain, stiffness and other debilitating symptoms of the hip joint. The pain can occur if the labrum is torn, frayed or damaged. Labral tears are most often casued by trauma or developmental hip dysplasia.

Labral tears are extremely common in elderly people and less common in young adults.

Symptons:

Pain in the front of the hip (most often in the groin area) accompanied by clicking, locking or catching of the hip

Joint stiffness and a feeling of instability

Pain that radiates to the glute, along the side of the hip or down to the knee

Pain may be aggravated by long periods of standing, sitting, or walking, worse on flexion. May progress to become continuous

Contraindications:

Arthroscopic debridement treatment is not advised if you have any of the following conditions:

Advanced hip arthritis

Acetabular protrusion

Hip ankylosis

Skin lesions at portal sites

Surgical Procedure:

The patient will be admitted into hospital for a day or overnight. The procedure is performed either under general anaesthesia or spinal anaesthesia.

At the start of the procedure, the leg is put in traction. The hip is pulled away from the socket enough for the entire joint to be visible and for instruments to be inserted.

A small puncture (about the size of a button hole) is be made for the arthroscope through which the inside of the hip and its damage can be identified. X-ray control using an image intensifier is used to gain access to the joint.

Two or three small incisions (portals) are made just above the bony prominence of the hip and instruments are inserted; first to visualise and treat any spurs on the femoral neck or acetabulum and then traction is applied where the instruments gain access to the hip joint to treat any pathology intra-articulary on the hip. These instruments can also smooth off rough surfaces, remove loose pieces of cartilage and excise bony osteophytes that may be causing a problem.

Sufficient traction is applied to open the joint by 7-8mm.

Local anesthetic is injected into the hip and wound following the procedure.

Depending on the approach taken and the individual condition the above overview may vary.

Complications:

As with any operation complications are possible but unlikely. Such complications associated with hip arthroscopy can include:

Nerve injury – the pudendal nerve may be damaged by the traction post. This is usually temporary and rarely permanent.

Permanent damage to the lateral femoral cutaneous nerve may occur in around 2% of patients.

Inadvertent chondral damage.

Infection in the skin or deep in the hip in less than 1% of patients.

Vascular injury; resulting in excess bleeding.

Ongoing pain; especially if there is significant arthritis.

Published in Information

Tuesday, 01 May 2012 00:00

Total Hip Revision Arthroplasty Techniques - Exposure

JAAOS Monograph series (Paprowsky).

Exposure

Trochanteric techniques:

1. Trochanteric slide

This is a modification of the direct lateral approach (Hardinge).

The anterior portion of the GT is osteotomised with the insertion of gluteus medius, and origin of vastus lateralis attached to it. This is then reflected anteriorly to expose the femoral metaphysis and acetabulum.

It is reattached by circlage wires passed around the LT.

The opposing forces of the gluteus medius (pulling it superior), and vastus lateralis (pulling it distal), results in inherent stability.

Problems:

Re-attaching such a small flake of bone – non-union.
Any limb lengthening may make re-attachment quite difficult.

2. Vastus slide

Essentially this is a subperiosteal peel of the origin of the vastus lateralis, and anterior insertion of gluteus medius.

The incision is in the shape of a question mark.

3. Extended proximal femoral osteotomy

An osteotomy of the anterolateral 1/3 of the proximal femur, including the entire GT.

The abductors and VL remain attached to fragment.

It is carried as distal as necessary to facilitate removal of the implant.

Pre-op templating will show how far this is – the revision stem must be longer than the end of the osteotomy site by at least 4cm or 2 cortical diameters.

Technical tips:

Elevate the VL from the femur.
Use a bur to make the distal, transverse limb – round the edges to minimise stress riser.
Oscillating saw for the vertical limb.
Re-attach prior to preparation of the revision stem.
Prior to re-insertion of revision stem place a prophylactic circlage wire around the femur just distal to the distal extent of the osteotomy in order to prevent propagation.

Removal techniques

1. Poly exchange

Always be prepared with equipment for entire acetabular revision in-case the locking mechanism is damaged.
Techniques are;
Implant specific tools.
Drill into the polyethylene.
Split the polyethylene.

2. Cemented acetabular removal

In order to disrupt the bone-cement interface, you usually need to disrupt the implant-cement interface first.
Start superio-lateral edge of the cup.
Pass curved gouges and osteotomes to disrupt the implant-cement interface.
In removing cement be wary of possibility if intrapelvic content adhesion to cement fragments.

3. Cemented cup removal

The aim is to remove the cup with minimal bone loss.

Techniques are;

Good circumferential exposure. This is essential.
Passage of curved gouges and osteotomes.
Be very careful of levering on the cup.
Large lever arms can be generated. Cup removal with a large number of bone attached is dire. Titanium implants may be cut into quarters using midas-rex type device.

4. Cemented femoral stem removal

Obtain circumferential exposure of shoulder of prosthesis. This is crucial.
May require trimming of any over-hanging trochanter.
Disrupt the implant-cement interface first.
Attach an extraction device and extract the stem.
Piece-meal extraction of all cement.
Remove in a proximal to distal fashion.

Variety of tools:

Currettes, flexible osteotomes, gouges.
Use an osteotome to longitudinally split the proximal cement mantle.
Used curved or flexible osteotomes and gouges to remove cement further down the shaft.
Burs.
Drill and screw in tap. Particularly useful in removing the distal cement plug.
Sequential drilling and reverse hooks.

Supplementary techniques:

Osseous windows – distal to cement plug.

5. Cementing back into a cement mantle

It is essential in this situation where the cement mantle is not compromised. (For example, Revision for limb length, acetabular revision.)

6. Cementless femoral stem removal

Removal technique is dependent on the particular stem – need to know where the in growth surfaces are and disrupt these bone-prosthesis interfaces.
Proximal porous coating - proximal disruption.
Extensively porous coating - more extensive disruption (diaphyseal).
Usual principles.
Proximal exposure.
Take care and be patient – preserve bone stock.
Flexible osteotomes.
“Episiotomy” – useful in proximal porous coated.
Lift the VL anteriorly at its origin to expose the metaphyseal/diaphyseal junction.
Use an oscillating saw to make a 10cm longitudinal osteotomy in this region of posterolateral proximal femur.
Attach the extractor to the stem and make sequential impaction-extraction attempts.
Extended proximal femoral osteotomy.
Take down to just distal, to the distal extent of the porous coating.
Pass a Gigli saw around the proximal stem to disrupt the bond at the calcar.
Windows at sites of spot-welding.

Published in Surgical Notes

Tuesday, 01 May 2012 00:00

Knee Arthroscopy

Knee arthroscopy is an excellent minimally invasive operation that allows thorough visualisation of the knee joint in order to diagnose and address various pathology inside and outside the knee joint.

It is keyhole surgery that can be done alone or in association with other surgeries such as Anterior Cruciate Ligament Reconstruction or Medial Patellofemoral Reconstruction for recurrent patella dislocation.

Surgical Procedure

Knee Arthroscopy is generally only a day surgery procedure. The patient presents at the hospital the day of the surgery and then leaves within a few hours after the surgery has been completed.

Arthroscopy is usually performed under a general or regional anesthetic. The insertion point is through two or more cuts at the front of the knee less than 1cm long through which a camera or telescope camera and other instruments are inserted to diagnose and treat pathology inside the knee.

Knee Arthroscopy Indications

Meniscal tear, debridement or repair

Removal of loose bodies and/or foreign bodies

Treatment of cartilage damage

Diagnosis, assessment and treatment of intraarticular fracture

Assess anterior cruciate ligament and posterior cruciate ligament

Reconstruction of the Anterior Cruciate Ligament

Treatment of plica lesions

Assessment of arthritic changes in the knee

Patello-femoral (knee-cap) disorders

General diagnostic purposes

Knee Arthroscopy Contraindications

Advance arthritis

Patient unsuitable for surgery

Post Surgery Activities

To stablise muscles and ensure the surgery is a success, strengthening exercises will need to be undertaken six weeks post surgery. At this time the patient can also return to jogging, provided it is a in a straight line, as well as return to most other sports. At this stage any movement that involves twisting and turning of the knee should be avoided.

Skiing, snowboarding or any similar sport that involves twisting and turning of the knee can be commenced six months after the surgery.

Published in Information

Tuesday, 01 May 2012 00:00

ACL Reconstruction General Information

The Anterior Cruciate Ligament (ACL) is tough fibrous rope like structure in the centre of the knee that connects the lower end of the thigh bone (femur) to the upper end of the shin bone (tibia). It is approximately 25mm in length with the diameter of a pen. Its primary function is to prevent the femur from moving abnormally apart from the tibia especially during athletic activities.

The ACL is the main support structure of the knee that prevents:

The tibia from translating forward on the femur

Valgus, varus and hyperextension of the knee

Rotation of the thigh bone (femur) on the shin bone (tibia)

When this ligament suffers a tear it doesn’t heal on its own and will often lead to a feeling of instability in the knee.

An ACL rupture is one of the most common knee injuries and one of the most common sports injuries. It is recommend to reconstruct a torn ACL to prevent future osteoarthritis and further damage to the knee joint.

ACL rupture in females is three times more common than males. This is due to:

Oestrogen hormones which lead to weaker collagen

Anatomical tight notch

A wider pelvis which leads altered mechanics and increases valgus stress on landing from a jump

70% of pure ACL ruptures are from a non-contact injury since contact injuries are more likely to result in other ligament injuries such as torn posterior cruciate ligaments and collaterals (medial cruciate ligament, lateral cruciate ligament) as well as the rupture of the ACL.

Signs and Symptoms

Most injuries to the ACL are sports related and result from a twisting injury to the knee, a forceful jump with the knee in flexion, a sudden change of direction, a direct blow to the knee or landing awkwardly.

Pain when bearing weight on the affected leg or at rest
Swelling of the knee joint which can occur within 24 hours of the injury
Most likely there will be some instability when walking and the feeling of being unstable or ‘wobbly’ on the leg as well as the sensation of the knee feeling not as tight or compact as it was previously
30%-50% of patients report hearing and feeling a ‘pop’ which occurs when the ligament tears

Diagnosis

A physical examination can reveal instability of the knee but the best current method of identifying a torn or damaged ACL is by using an MRI scan which has a high sensitivity and specificity in diagnosing ACL injury and any associated meniscal injury. In extremely difficult cases, sometimes the final diagnoses can only be made during arthroscopy surgery.

For ACL surgical interventions and treatment options please see ACL Reconstruction Treatment Options.