The classic Hill-Sachs lesion is a compression or impression fracture of the humeral head in occurrence with anterior glenohumeral instability. The true incidence is unknown but clearly increases with recurrent instability episodes. Recent peer-reviewed literature has highlighted the importance of addressing “significant” humeral and glenoid bone defects in the management of glenohumeral instability. Quantification of the “significance” of a Hill-Sachs lesion with regard to location, size, and depth in relation to the glenoid has helped guide indications for surgical management.

Options for managing Hill-Sachs lesions include both humeral-sided techniques (soft tissue, bone, and/or prosthetic techniques) and also glenoid-sided techniques (bone transfers to increase glenoid width). The majority of significant acute or chronic Hill-Sachs lesions can be effectively managed without prosthetic replacement.

Is a prosthetic surface replacement ever indicated for the management of Hill-Sachs lesions? The peer-reviewed literature is sparse with the outcomes of this treatment, and significant consideration must be given to both the age of the patient and the need for such management when other effective non-prosthetic options exist. In a patient with more than half of the humeral head involved after instability episodes (perhaps seizure or polytrauma patients), metallic surface replacement arthroplasty may be an option that could require less involved post-operative care while restoring range of motion and stability.

The Hill-Sachs lesion is a bony defect of the humeral head that occurs in association with anterior instability of the glenohumeral joint. Hill-Sachs lesions are common, with an incidence approaching nearly 100% in the setting of recurrent anterior glenohumeral instability. However, the indications for surgical management are very limited, with less than 10% of anterior instability patients considered for treatment of the Hill-Sachs lesion. Of utmost importance is addressing bone loss on the anterior-inferior glenoid, which is highly successful at preventing recurrence of instability even with humeral bone loss. In the rare situation where the Hill-Sachs lesion may continue to engage the glenoid, surgical management is indicated. Surgical strategies are variable, including debridement, arthroscopic remplissage, allograft transplantation, surface replacement, and arthroplasty. Given that the population with these defects is typically comprised of young and athletic patients, biologic solutions are most likely to be associated with decades of sustainable joint preservation, function, and stability. The first priority is maximising the treatment of anterior instability on the glenoid side. Then, small lesions of less than 10% are ignored without consequence. Lesions involving 10–20% of the humeral head are treated with arthroscopic remplissage (defect filled with repair of capsule and infraspinatus). Lesions greater than 20% that extend beyond the glenoid tract are managed with fresh osteochondral allografts to biologically restore the humeral head. Lesions great than 40% are most commonly associated with advanced arthritis and deformity of the humeral articular surface and are therefore treated with a humeral head replacement. This treatment algorithm maximises our ability to stabilise and preserve the glenohumeral joint.

Retroversion, also referred to as posterior wear of the glenoid, can make resurfacing the glenoid challenging. However, careful pre-operative planning with three dimensional CT scanning can allow central placement of the glenoid component through removal of some of the anterior bone to allow contained placement and secure fixation within the glenoid vault.

Since the scapula is not a fixed skeletal structure and moves substantially on the chest wall, the actual degree of posterior wear (retroversion) frequently is the result of extraneous biomechanical forces and structures. For example, the degree of kyphosis and shape of the rib cage can have a substantial impact on the relative position of the glenoid surface as it articulates with the humerus. Attempts to totally equalise this through implant augmentation have not, to date, been shown to be effective, and in some cases can be destabilising. Restoration of enough alignment to place the implant centrally can be achieved without need for augmentation even in some very hypoplastic glenoids. The technique for this straight-forward approach will be presented, including pre-surgical planning, in some cases, patient specific instrumentation, with demonstration of functional outcomes.

Contracture of the anterior musculature causes posterior humeral head subluxation and results in a posterior load concentration on the glenoid. This reduced contact area causes glenoid wear, humeral medialisation and eventually posterior instability. After arthroplasty that does not correct for this, posterior wear stress increases in the implant, across the cement mantle and bone thus increasing the risk of aseptic loosening over time.

Correction of the posterior wear pattern at the time of arthroplasty of the shoulder is recommended. Asymmetric reaming of the glenoid has been recommended as a means to correct this deformity but leads to producing a smaller glenoid which is medialised. This shortening of the glenoid causes the stabilising muscle envelope to shorten and the glenoid vault to become much smaller in volume. These potential changes may have a destabilising effect on the implant leading to early loosening and secondary failure of the prosthetic implant.

Other options include using an implant to make the correction of the deformity such as augmented glenoid components. Early uses of these implants were not successful mainly due to the design flaws of the early implants. Newer implants have made design changes to overcome these early failures. CT scan evaluation is important to determine the degree of correction that is needed to balance the glenohumeral joint. Correcting the deformity and keeping the muscle envelope at the appropriate tension may lead to better long term outcomes. These implants are currently in use but long term outcome studies are not yet available to determine their ultimate values to the patients.

The current standard of care in the United States for the treatment of an infected arthroplasty, whether it be a TKA, THA or TSA remains two stage revision. We performed a systematic review of the English literature to answer the question of whether one-stage or two-stage revision of infected shoulder arthroplasty was better in terms of re-infection rate, patient satisfaction and patient function. There were no prospective, randomised studies comparing these two approaches. We found 19 studies with a minimum one year follow up which described 99 patients with two-stage revision, 38 with one-stage revision and 36 with spacers. There were no significant differences between the groups for recurrent infection rate or complication rate. The spacer only group had higher satisfaction than the one-stage group, but the satisfaction rate between the one- and two-stage groups was not statistically different.

Unfortunately, the numbers in our study were small and based upon level IV evidence. It is interesting that currently the data do not support two-stage over one-stage revision of an infected TSA. So why do we continue to use two-stage revision? I believe it is the fear of litigation to a certain degree but also historical bias toward two-stage revisions. The only time I would do a one-stage revision is if (1) it is a low virulence organism, (2) the prosthesis can be easily removed and (3) the patient was too sick to tolerate multiple operations.

The infected shoulder arthroplasty is a devastating complication that can be very difficult to diagnose and treat. This presentation will compare the data on two-stage and single-stage exchange arthroplasty as pertains to functional outcomes and efficacy of eradication of the infection. Traditionally, the two-stage exchange arthroplasty has been the gold standard in the United States for the treatment of infected total shoulder replacements. In Europe, the trend seems to be moving towards a single-stage exchange with results that are reportedly comparable for eradication of infection to those of two-stage exchange although with seemingly better results for shoulder function. The surgeon's clinical experience with both techniques will be highlighted. A lively debate of the virtues and pitfalls of both approaches is the goal.

Reverse shoulder arthroplasty (RSA) was released into the United States market in 2004 for the indication of Rotator Cuff Tear Arthropathy. Since that time the indications have widened and now include massive rotator cuff tears that are not deemed to be surgically repairable. This diagnosis includes patients that are considered young in terms of shoulder replacement surgery. These patients do not have the radiographic changes of arthropathy, but most have undergone multiple surgical procedures in the past to attempt to repair the rotator cuff deficiency. These younger patients have a different post-op expectation than the patient with advanced arthropathy over the age of 70.

The complication rate seen in this younger patient population is higher than seen in the older population undergoing RSA. The post-operative survey for satisfaction is also considerably lower in the younger population group.

RSA for massive rotator cuff tears in a younger population under the age of 65 years gives a lower patient satisfaction result and a higher complication rate than age-matched patients older than 65 years. Although this is still the best procedure available for this difficult diagnosis, patients younger than 65 years should be consulted as to what their expectations are post-operatively. Pain relief is still the main reason to undergo an RSA.

The incidence of total shoulder arthroplasty continues to increase. The most common reason for failure of a total shoulder arthroplasty is the glenoid component. Two styles of cemented all-polyethylene components are commonly implanted. These two styles are pegged glenoid and keel glenoid components. Data regarding the superiority of the styles has focused on radiolucent lines, complete loosening and need for revision procedures. Several retrospective and randomised controlled trials have been published to examine these endpoints. There is a trend in the literature to demonstrate decreased rates of radiolucent lines with pegged glenoid components, but a recent systematic review of available trials did not demonstrate a significant difference in the rate of radiolucent lines between the two styles. A slightly increased rate of revision was noted for the keel components. Overall pegged and keel glenoids both still represent good options in total shoulder arthroplasty.

Assessing glenoid version is important for a successful total shoulder arthroplasty. Glenoid version is defined as the orientation of the glenoid cavity in relation to a plane perpendicular to the scapula body. Glenoid revision averages between 1 to 2 degrees of retroversion and varies between race and sex. In general glenoid retroversion is overestimated by 6.5 degrees on plain radiographs. Furthermore standard axial 2D CT is aligned to the patient's body and not aligned to the scapula. Therefore 3D reconstructions generated from standard CT allows for analysis of the scapula as a free body and correct version measurements can be made unaffected by positioning. If you add a computer modeling coordinate system in which implants can be added, then computer simulation surgery can be performed. This is important because implanting a glenoid component in excessive retroversion leads to increased stress at the glenoid component and cement mantle and decreased contact with the humeral component. Also excessive reaming of the glenoid surface to neutral retroversion can lead to excessive bone loss and penetration of the glenoid vault by either the pegs or the keel of the glenoid component.

Rotator cuff tendon healing has proven to be a substantial clinical challenge. There is significant interest in finding biologic augmentation methods to improve this healing process. Two currently available products include platelet rich plasma/platelet rich fibrin matrix and several commercially available extra cellular matrix (ECM) patches. Platelet rich plasma is a sample of an autologous blood which has been centrifuged to a concentration of platelets three to four times that of normal. Platelets contain multiple growth factors, many of which have been shown to be involved in all phases in tendon healing. An alternative is platelet rich fibrin matrix. This forms a fibrin matrix with the platelets embedded within. Growth factors are subsequently released as the fibrin is reabsorbed. There are only a few studies which look at the effectiveness of platelet rich plasma and fibrin matrix. Overall, there is no strong evidence to support its routine use in the setting of rotator cuff repair. Extra cellular matrix patches are used to reinforce the strength of the repair and offload the tendon. They also provide the potential to form a scaffold for new growth and differentiation and may at some point be a delivery vehicle for cells and growth factors. There are currently two prospective randomised studies evaluating ECM patches – one showed that the patch studied was actually harmful to repair and the second suggested there was some benefit in larger tears. While there is not a lot of strong evidence to support routine use, further research and development is necessary to maximise this strategy.

Is there an optimal way to place a glenoid in reverse total shoulder arthroplasty (RTSA)? Four of the six parameters that a surgeon can control in a RTSA involve the glenoid. The parameters are: inferior tilt, increased lateral or inferior offset and increased glenosphere diameter. The theoretical challenges are further complicated by the normal variations that exist in the bony anatomy of the scapula and pathological abnormalities prevalent in as many as 40% of patients undergoing RTSA. Over the last 5 years there has been a growing body of data and study on the biomechanics, clinical outcomes and complications of this prosthesis. What have we learned? How does a surgeon incorporate this into their practice? The goal of this talk is to briefly review the current status of biomechanics on the impact of glenosphere positioning and offset on the outcome of reverse arthroplasty.

Anatomic and accurate placement of components is a primary goal in all arthroplasty procedures. Unique to total shoulder arthroplasty, challenging glenoid exposure and osteoarthritic glenoid deformity offer significant challenges and impediments to this goal. Despite thorough pre-operative planning strategies and contemporary cannulated pin-based shoulder systems, it is often times still difficult to accurately aim the guide pin to the medial border of the scapula when the deformity is substantial or exposure is difficult. Even small errors in guide pin position can result in problems with final component version, inclination and glenoid vault perforation. In addition, a malpositioned glenoid component has been shown to have a negative impact on implant longevity and clinical performance.

Image-based patient specific instrumentation has been available in the lower extremity for nearly a decade with reliable results. The application of similar technology in the shoulder has demonstrated reliable positioning of the guide pin to a pre-operative plan with subsequent accurate placement of the glenoid component. This surgical demonstration will feature one of the currently available CT-based patient specific glenoid guides using a standard deltopectoral approach.

Radiolucent lines in total shoulder arthroplasty around the glenoid component are not uncommon in post-operative x-rays and the incidence varies. A certain percentage progress and as the lines enlarge can lead to component loosening. One study reported a 9% incidence at 2 years and 27% incidence at 5 years. A recent long term study (15 to 20 years) reported a 73% incidence. Radiolucent lines can be caused by anatomy (posterior glenoid wear) or pathology (inflammatory arthritis) as well as technical factors such as glenoid implant design (metal back) and improper implantation techniques where the prosthesis is not fully seated or cement is used to fill a defect. Every attempt should be made to avoid lucent lines. Minimal bone should be removed from the glenoid vault and a pressure injection type of insertion is helpful in getting the cement into the cancellous bone. Furthermore a peg type of glenoid implant rather than a keel type is preferred as this has been associated with a lower incidence of radiolucent lines.

There is nothing going to ruin your day like a complication after shoulder arthroplasty, either hemiarthroplasty (HA) anatomical (TSA) or reverse arthroplasty (RTSA). While complications are fortunately uncommon with anatomical shoulder arthroplasty (approximately 8% but as high as 40%), the complication rate for RTSA has been reported as high as 70%. Most complications are multifactorial and cannot all be blamed on the patient. Basically you do not want to operate upon a young patient who is an insulin dependent diabetic, has an ASA of 3 or 4, who smokes, has HIV disease and has a BMI over 40.

The most common predictors of failure are determined by the indication for surgery, the type of implant used and the skill of the surgeon. The major risk factors for HA are eccentric glenoids, young age and rotator cuff failure. The biggest risk factors for TSA are metal backed glenoid components, younger age of the patient, rotator cuff pathology and insufficient glenoid bone. The major risk factors for RTSA are the type of component used (Grammont type versus lateral center of rotation designs) and the indication for surgery. Infection risks include previous infected arthroplasty, previous joint infection, immunosuppression (e.g. steroid use, insulin dependent diabetes, HIV disease), ASA 3 or 4 and higher BMI (i.e. over 40). Not all of these risk factors can be prevented in patients but informed consent is critical to the patient understanding the potential outcomes of their surgery.

Total shoulder arthroplasty has been shown to be a very effective means of restoring function in all forms of arthritic shoulders. However, much as with any form of arthroplasty, problems and complications can and do occur. These include infection, nerve injury, anesthetic complications, peri-prosthetic fracture, instability and dislocation, nerve and vascular injury, loosening, loss of mobility, and contracture or stiffness, and implant related failures.

Careful pre-operative planning, intra-operative technical execution, and post-operative rehabilitation all designed to meet the needs and demands of the specific patient can help identify potential sources of complications pre-operatively and avoid them post-operatively. Understanding the specific complexities of the type of arthritis being addressed, the strengths and weaknesses, limitations and need for adjustments to the local anatomy can help the surgeon execute the total shoulder arthroplasty with minimal likelihood for post-operative complications. Awareness of patient's own flora and application of appropriate antibiotic prophylaxis can help identify patients at risk for infection.

Although it is impossible to fully eliminate the occurrence of complications, a majority can be avoided through attention to detail.

Peri-prosthetic fractures around implants in the proximal humerus can present substantial challenges. Most individuals who undergo upper limb arthroplasty tend to be osteopenic to begin with, and the anatomy of the proximal humerus does not provide an excess of bone to work with. Therefore, peri-prosthetic fractures pose difficulties to rotator cuff function and implant stability. There are multiple classification systems, but series are small and the classification does not always lead to treatment algorithms. Risk factors for humeral fractures after shoulder arthroplasty include endosteal notching, cortical perforation, varus malalignment, stem perforation, ipsilateral shoulder and elbow arthroplasties, and loose stems. Many of these risk factors are directly related to technical errors at the time of surgery. Poor exposure can lead to aberrant starting point and errors in reaming. Oversized prostheses can lead to cortical perforation or even stem perforation. Proper positioning of the patient on the table and surgical releases help avoid these technical errors. Peri-prosthetic fractures should be carefully evaluated radiographically for stability. Two important considerations: 1. Is the implant stable? 2. Is the fracture stable? Generally, if the implant is unstable, the implant must be revised. In the setting of a stable implant, many humeral fractures can be treated nonoperatively. Many fractures at or below the level of the tip of the implant can be treated as typical humeral fractures. Options for fixation include plates with cables or long stem prostheses which bypass the fracture. Displaced tuberosity fractures are treated with suture or wire fixation. Risk factors for a poor outcome include increased time to union, skin breakdown, and stiff shoulder.

While the definition of “stiffness” after shoulder arthroplasty remains controversial, loss of range of motion in the post-arthroplasty setting can be a disabling functional complication. Fortunately, the incidence of post-operative loss of both active and passive range of motion is relatively less common following shoulder replacement procedures. Certain pre-operative diagnoses (proximal humeral fracture, capsulorraphy arthropathy, revision arthroplasty) are associated with post-operative soft tissue contractures. Certain medical comorbidities (diabetes, inflammatory arthropathy) are associated with periarticular capsular adhesions at the intracellular level.

Management of the “stiff” shoulder arthroplasty must account for several confounding variables:

Appropriateness of diagnosis leading to arthroplasty

Techniques for management include soft tissue contracture release (manipulation, arthroscopic, open) and component revision.

Shoulder arthroplasty is increasing and can lead to excellent results for the proper indicators. We will review cases of primary shoulder arthroplasty as well as complex cases. Furthermore we will present complications of shoulder arthroplasty and how they are successfully managed.

Indications for total shoulder arthroplasty (TSA) require that the patient have a functioning rotator cuff to stabilise the glenohumeral joint. Without rotator cuff integrity the prosthesis will be unstable and the functional result will be less than expected. Physical exam can be difficult in the arthritic shoulder as contractures will limit the range of motion needed to adequately exam the rotator cuff status. The diagnosis can help as osteoarthritis has a 5% incidence of rotator cuff tear while rheumatoid arthritis has an incidence of greater than 40%. MRI can be obtained to determine the rotator cuff status before arthroplasty is performed but may not be necessary. Most total shoulder implant companies have both reverse and anatomic implants available. More recently the uses of platform stems that can be used with either RSA or TSA have been available. With this development in prosthetic design it is no longer necessary to determine the status of the rotator cuff before surgery. The surgeon can make the decision at the time of surgery which implants RSA or TSA will be necessary based on the status of the rotator cuff. There have been recent reports of longer follow up of TSA patients that had fatty atrophy of the infraspinatus muscle that had rotator cuff tears at 10–15 years. MRI may still be warranted in the older individual that is being considered for TSA to determine the quality of the rotator cuff musculature.

Shoulder arthroplasty procedures continue to increase in prevalence, and controversy still remains about the optimal method to manage the subscapularis. Scalise et al. performed an analysis of 20 osteotomies and 15 tenotomy procedures, and found the tenotomy group had a higher rate of abnormal subscapularis tendons on ultrasound examination. There was one tendon rupture in the subscapularis tenotomy group and no ruptures in the osteotomy group. Jandhyala et al. retrospectively examined 26 lesser tuberosity osteotomies and 10 subscapularis tenotomies for arthroplasty, and their study demonstrated a significant improvement in the belly press test for the osteotomy group. Lapner et al. performed a randomised controlled trial assigning patient to either a lesser tuberosity osteotomy or a subscapularis peel procedure. They evaluated 36 osteotomies and 37 subscapularis peels. The outcomes evaluated were Dynamometer internal rotation strength, the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score and American Shoulder and Elbow Surgeons (ASES) score, and in a subsequent paper they evaluated the healing rates and Goutallier grade. Their studies illustrated no difference in the internal rotation strength between groups. Both groups significantly improved WOOS and ASES scores post-operatively, but the difference was not significant between groups. Goutallier grade increased significantly in both groups, but there was no significant difference between the groups. Overall, the different approaches have not demonstrated a meaningful clinical difference. Further studies are needed to help understand issues leading to subscapularis complications after arthroplasty.

The functional importance of the long head of biceps tendon remains controversial, but it is well accepted as an important source of anterior shoulder pain. Both biceps tenotomy and tenodesis have well-documented results in the native shoulder. Management of the long head of biceps tendon during shoulder arthroplasty remains controversial. The existing literature supports surgical treatment of the biceps during shoulder arthroplasty. Walch et al. reported the largest series in multicenter study of over eight hundred shoulder arthroplasty patients with or without biceps tenodesis. The authors found more reproducible pain relief with biceps tenodesis and no difference in range of motion. Similarly, Soliman et al. reported on a prospective review of 37 patients undergoing hemiarthroplasty for fracture randomly assigned to biceps tenodesis vs. no treatment. The authors found a statistically significant improvement in Constant score and shoulder pain with biceps tenodesis. If left untreated during shoulder arthroplasty, the intact biceps tendon may be a source of anterior shoulder pain requiring revision surgery. Tuckman et al. reported excellent pain relief after biceps tenotomy or tenodesis for biceps-related pain after previous shoulder arthroplasty. The decision to perform a biceps tenotomy versus a tenodesis during shoulder arthroplasty also remains controversial. Tenotomy may increase the risk of cosmetic pop-eye deformity and muscle cramping or fatigue over tenodesis. Therefore, routine long head of biceps soft tissue tenodesis is recommended during shoulder arthroplasty as it safe, reproducible, cost-effective, associated with improved outcome scores, and minimises the risk of cosmetic deformity and pain associated with biceps tenotomy.

There are unfortunately many reasons a TSA can be painful after implantation, but the most common reason is sepsis. Making the diagnosis can be a major challenge, but the biggest challenge is to think of that as a diagnosis! The most important steps are to first obtain plain radiographs one week after surgery so that you can compare subsequent radiographs to the immediate post-operative films. Progressive radiolucent lines in the glenoid or especially around the humerus are important hints. A loose humeral component is infected until proven otherwise. Next blood work to include CRP and ESR are critical. Other markers of infection have not been used on a widespread basis. If there is concern that there might be rotator cuff pathology and not sepsis, then we obtain an arthrogram CT scan at the time of aspiration. A cell count is helpful but often there is a dry tap. It is important to create a “p. acnes protocol” at your hospital to take cultures out 15 days. If still not sure and revision is necessary then we aspirate the joint at the time of surgery for cell count. The WBC cell count at the time of surgery keeps changing but over 3000 is considered diagnostic. Multiple specimens are sent for frozen section, culture and permanent section. The more WBC per high powered field the more likely there is an infection. Gram stains are worthless and we do not rely on them. We have no experience with implant sonification or use of IL-6.

Aseptic loosening of the glenoid after total shoulder replacement is a challenging problem to manage clinically. In the right circumstances, arthroscopic retrieval of loose polyethylene glenoids can be a valuable tool in the shoulder surgeon's repertoire for dealing with this uncommon problem. The purpose of this talk is to demonstrate the technique for arthroscopic removal of a loose glenoid and review the clinical circumstances where this procedure may play a valuable role.

Most presentations about total knee arthroplasty begin with a statement that the procedure has been one of the great successes of modern surgery. However, not all patients consider their total knee a success. Success requires that patients experience relief of arthritic pain, return of function, and satisfaction with the result. Patients need to be aware of the limitations of implants and accept reasonable expectations for the arthroplasty. If they don't, your next revision will likely be on a dissatisfied patient who had unrealistic expectations. The surgeon who operated on the patient for the primary intervention may feel obliged to try to make it better. Avoid your next revision by only intervening when there is a clear indication.

In a recent patient survey, 15–20% of patients were not completely satisfied with their arthroplasty in spite of having recent implant designs. It is a fact that some patients will not be satisfied with any intervention. Fibromyalgia, depression, high narcotic use for arthritic pain, secondary gain (e.g., Worker's Compensation claims pending) are some of the conditions that predict a difficult post-operative course and an unsatisfied patient who will push for revision. To avoid your next revision, choose patients wisely and make sure they understand that the total joint is a poor substitute for the normal knee.

Design surgeons and engineers have developed techniques for a specific implant system to minimise the problems of malrotation, malalignment, instability, anterior knee pain, stiffness, loosening and polyethylene wear. Surgeons should be careful to use the recommended implantation philosophy and technique to avoid these problems. Choose implant systems with a proven track record. Learn how and why to use the instruments correctly. Study a system well and know the nuances. If you don't know the system well enough, take a course from the designers and ask questions. Using a system as it was intended will help avoid your next revision.

Prosthetic joint infection remains a major reason for revision. Some patients have a greater chance of developing infection. Attention to detail from pre-operative preparation to rehabilitation will minimise, but cannot eliminate, the occurrence of infection. The recently published International Consensus on Prosthetic Joint Infection contains recommendations that should be followed to minimise the chance of infection and thus help avoid your next revision for infection.

The indication for revision is presentation of a problem that can be corrected with surgery. If a patient is satisfied with a result, revision surgery would only rarely be indicated regardless of the radiographic result. (Severe wear would be an exception to this.) Recognising that “the enemy of good is better” will help you avoid your next revision.

The major benefit of TKA with tourniquet is operating in a bloodless field. A possible secondary benefit is a better cement bone interface for fixation.

The disadvantages of tourniquet use for TKA include multiple risk factors both local and systemic.

Nerve damage

Our initial experience with TKA without tourniquet was in high risk patients with previous DVT or PE, multiple scarring, or compromised cardiovascular status. We have used this method on all patients for the last eight years. The protocol includes regional anesthesia, incision and approach made with 90-degree knee flexion, meticulous hemostasis, jet lavage and filtered carbon dioxide delivered to dry and prepare bone beds for cementation, application of topical tranexamic acid and routine closure. We have encountered no differences in blood loss or transfusion rates, less post-op pain, faster straight leg raise and knee flexion gains, and fewer wound healing disturbances. We recommend TKA sans tourniquet. Let it bleed!

There has been ongoing debate for many years on the relative merits of routine tourniquet use while performing a total knee replacement. Interestingly there have been many retrospective reviews and opinion articles on the topic, but little in the way of well powered prospective randomised clinical trials.

Those that dislike the premise of routine tourniquet use usually cite a list of either very rare complications, or theoretical concerns (nerve damage, muscle function, wound healing issues).

Like most debate topics, however, the issue is usually a shade of grey, rather than black and white, if the pro/con arguments are evaluated individually.

1. Blood Loss

There can be little debate that intra-operative blood loss is less with the use of a tourniquet. This has been demonstrated in multiple studies and is clearly intuitively obvious. Interestingly the overall blood loss (intra-op + post-op) may, however, be the same regardless of tourniquet use. Having a dry operative field, however, is important in achieving adequate cement fixation, and if tourniquet use is not employed, an alternative should be.

2. OR time

There is an overwhelming body of literature that supports the understanding that increased OR time directly correlates to increased infection rates in total joint arthroplasty. Proponents of not using a tourniquet will often have alternates to achieving a dry operative field that clearly add time to the procedure – meticulous hemostasis, air delivery systems, etc. This increased OR time may come at the cost of increased infection risk.

There is clearly a need for well-designed randomised clinical trials evaluating the practice of routine tourniquet use in TKA. Any trial done, however, must look critically at factors such as OR time, costs of alternatives, and potential long-term outcome effects.

Bilateral one-stage total knee replacement has a number of advantages. There is one operative procedure and anesthetic and overall recovery time is significantly reduced. It is a more cost effective procedure in that acute hospital stay is less and although rehabilitation time is greater in the short term overall it is less. Additionally if there is a bilateral flexion contracture present there is an inevitable loss of extension if a single knee is operated upon as this knee will assume the position of the unoperated knee. Patients greatly prefer having both knees corrected at one operative setting rather than having to have the inconvenience and pain associated with a second operative procedure at three to six months after the first one.

There are potential disadvantages to a one-stage procedure. One concern has been that there is more peri-operative morbidity associated with one-stage bilateral total knee replacement. In a review of 501 patients undergoing bilateral one-stage total knee replacement at the Hospital for Special Surgery there were no peri-operative deaths, myocardial infarctions or cerebrovascular accidents. There were arrhythmias present in 5% of patients. Fat emboli were present in 3% and 2 patients (0.4%) had pulmonary emboli. The average transfusion requirement was 2.6 units and allogeneic blood was required in 42%. There were 2 deep infections, 3 hematomas and 5 patients with delayed wound healing. Average hospital stay was 7.2 days but this had decreased in the more recent patients. There was an increased incidence of major complications in patients with ASA classification 3 and with increasing age over 70 years.

New data indicates peri-operative administration of hydrocortisone may mitigate lung injury as demonstrated by reduction in cytokine and desmosine levels in a randomised trial.

Patient selection is important and all patients are screened pre-operatively by an internist and anesthesiologist. All patients underwent the procedure with epidural anesthesia with post-operative epidural PCA for 48 hours. All patients are discharged on warfarin and spend the operative night in the recovery room. The procedure has acceptable morbidity and great advantage in properly selected patients.

Over the past 30 years, cemented, cementless, and hybrid fixation options have been utilised with various total knee arthroplasty (TKA) implant systems. While cemented components are widely used and considered the most reliable method of fixation, historical results may not be applicable to contemporary patients, who are increasingly younger than 65 years of age. Moreover, the literature is not definitive on which method of TKA fixation obtains the best clinical, functional, and radiographic results. A recent Cochrane meta-analysis on roentgen stereophotogrammetric analysis (RSA) included five randomised clinical trials (RCTs) in 297 participants. The authors observed that cemented fixation of tibial components demonstrated smaller displacement in relation to cementless fixation. However, the risk of future aseptic loosening with uncemented fixation was approximately half that of cemented fixation (risk ratio = 0.47, 95% CI 0.24 to 0.92) with a 16% absolute risk difference between groups. Almost all included studies recorded functional measures of Knee Society and Hospital for Special Surgery knee scores, but the authors of each study found no significant difference between the groups. Recently, highly porous metals have become an attractive fixation option in TKA due to their biomechanical properties. In a large RCT of 397 patients, Pulido et al. found that uncemented highly porous metal tibias provided comparably durable fixation and reliable pain relief and restoration of function when compared with traditional cemented modular tibias. While longer-term studies are needed, cementless TKAs may be a durable and reliable alternative with highly porous metals, particularly in younger patients.

Whether cemented or cementless fixation is superior in TKA is a controversial issue. There are few high quality papers assessing the merits and demerits of cementless and cemented fixation and these will be highlighted. Roentgen stereophotogrammetric analysis (RSA) is an important tool to determine early loosening of components after TKA. There is a high correlation between loosening and early migration of implants seen in the first 2 years after surgery. Hence it is a valuable tool to determine the likelihood of failure in studies with short follow up. Meta-analyses that include papers using RSA are therefore the most valuable and these will be summarised.

In view of the fact that the majority of patients undergoing TKA worldwide are low-demand and elderly persons, in view of the higher cost associated with cementless knees, and the equivalence or superiority of results of cemented TKAs with regards to clinical outcomes and survival in the intermediate term, cemented TKA remains the gold standard in the medium term.

Patient expectations have escalated over the past several decades with respect to demand for success with total knee arthroplasty (TKA). It is reported that 15 to 20% of TKA recipients are unsatisfied with their result. Dynamic fluoroscopic studies and gait analyses have demonstrated that patients with TKA do not exhibit normal kinematics. On the other hand, patients with partial knee arthroplasty demonstrate more normal kinematics, thought to be secondary to retention of the anterior cruciate ligament (ACL) along with the posterior cruciate ligament (PCL). While not a new concept, bi-cruciate retaining designs in TKA that preserve the natural ligament structure of the knee are drawing renewed interest as an option for patients with higher and more complex activity demand. These designs may result in a more natural kinematic feel as perceived by the patient. This surgical demonstration will outline patient selection criteria and illustrate the technique for performing ACL- and PCL-preserving, bi-cruciate retaining TKA.

The evidence to help the surgeon decide on the merits of which type of replacement to offer their patients is steadily mounting and comes from large datasets such as joint registries.

There are many advantages of UKR vs TKR such as satisfaction, function, recovery, morbidity, mortality and cost but there is one major disadvantage. All registries show a higher failure rate with UKRs.

Registries show that there are more excellent and fewer poor Patient Reported Outcome Measure Scores (PROMS) with UKR compared to TKR and the higher revision rate is in major part due to the threshold of revision. For instance, 60% of UKR are revised vs 10% of TKR with an Oxford score that is worse post-operation than pre-operation. Ease of revision with UKR is a major determinant of the higher revision rate.

The real issue with UKR relates to usage. Most surgeons perform very few UKR on young patients with early arthritis viewing the procedure as a pre-TKR. Low surgeon volume equates to high revision rate in the national registries. Surgeons should either abandon UKR or do an adequate number to ensure success.

Surgeons can improve their results by increasing their usage of UKR. The Unicompartmental Knee National Joint Registry (UKNJR) data shows that the optimal usage of the mobile UKR is between 20 and 50% of replacements. Fixed bearing usage is optimal at 20% but not higher.

The other major advantage concerns the lower mortality rate with UKR. At 90 days it is less than half that of TKR and even at 8 years it is 10% less. For every 10 UKRs performed rather than TKR then one life is saved at 8 years.

There is very little evidence suggesting that bi-UKR is necessary certainly with the mobile UKR. There is evidence, however that patellofemoral joint problems are a problem with fixed bearing UKR in the second decade.

Deformity can be associated with significant bone loss, ligament laxity, soft-tissue contractures, distortion of long bone morphology, and extra-articular deformity. Correction of varus, valgus, or flexion deformity requires soft tissue releases in conjunction with bone cuts perpendicular to the long axes of the femur and tibia. Cruciate-retaining or -substituting implants can be used based on surgeon preference if the ligaments are well balanced. However, in presence of severe deformity, additional measures may be warranted to achieve alignment and balance. TKA then becomes a more challenging proposition and may require the surgeon to perform extensive releases, adjunct osteotomies and deploy more constrained implants. Merely enhancing constraint in the implant, however, without attending to releases and extra-articular correction may not suffice.

Pre-operative planning, i.e., whether intra-articular correction alone will suffice or extra-articular correction is required, will be highlighted. Surgical principles and methods of performing large releases, reduction osteotomy, lateral epicondylar sliding osteotomy, sliding medial condylar osteotomy, and closed wedge diaphyseal/metaphyseal osteotomy concomitantly with TKA will be illustrated with examples. Results of a large series of TKA with extra-articular deformity resulting from coronal bowing of femoral or tibial diaphysis, malunited fractures, prior osteotomies, and stress fractures will be presented. The techniques reported can successfully restore alignment, pain-free motion, and stability without necessarily using more constrained implants.

Total Joint Arthroplasty (TJA) is associated with significant blood loss and allogeneic transfusion rates over 20% nationally. However, there are significant risks associated with allogeneic blood transfusion. Such risks include viral disease transmission, transfusion reactions, fluid overload, cost to the healthcare system, and prosthetic joint infection (PJI). As such, avoidance of transfusion is advised.

Minimising transfusion rates begins in the pre-operative phase and continues during the operative and post-operative phases. A lower pre-operative hemoglobin level is the strongest predictor for the potential need of allogeneic blood transfusion after TJA. Other risk factors include the use of general anesthesia, higher Charlson comorbidity index, female gender, and longer duration of surgery.

We present a comprehensive blood management strategy that encompasses all three phases. In the pre-operative phase, the most important intervention is screening for the presence of, and correcting, any preexisting anemia. During the operative phase, the use of hypotensive regional anesthesia is utilised when appropriate. In addition, tranexamic acid (TXA) is liberally utilised, either topically or intravenously. In the post-operative phase, transfusion triggers are carefully scrutinised. Only patients with symptomatic anemia despite fluid resuscitation are considered for blood transfusion. The threshold for transfusion is individualised for each patient, and is not merely based on a laboratory value.

Utilising this approach, we have decreased our transfusion rates from over 20% to just over 10%, even with a relatively unhealthy population at a tertiary referral center. The main driver of this reduction was the introduction of TXA as the standard of care for all TJA patients. TXA has been shown in multiple studies to be both safe and effective.

Perhaps the most significant developments in joint replacement surgery in the past decade have been in the area of multimodal pain management. This has reduced length of stay in the inpatient hospital environment opening the opportunity for cost savings and even outpatient joint replacement surgery for appropriately selected patients. The hallmark of this program is pre-emptive pain control with oral anti-inflammatory agents, gabapentin, regional anesthetic blocks that preserve quad function for TKA (adductor canal block) and pericapsular long acting time release local anesthetics with the addition of injectable ketorolac and IV acetaminophen. Over the past two years utilising this type of program over 60% of our partial knee replacement patients are now returning home the day of surgery.

We currently utilise a long acting local anesthetic delivery medication consisting of microscopic, spherical, lipid-based particles composed of a honeycomb-like structure of numerous nonconcentric internal aqueous chambers containing encapsulated bupivacaine separated from adjacent chambers by lipid membranes. Bupivacaine is released from the particles with diffusion of the drug over an extended period of time that more closely matches the time course of postsurgical pain following joint replacement surgery. Trials have demonstrated that a single dose administered via deep tissue infiltration is effective at reducing pain up to 72 hours. This has been trialed in TKA as well.

Venous thromboembolic events, either deep vein thromboses or pulmonary emboli, are important complications in patients undergoing knee or hip arthroplasty. The purpose of this study was to evaluate the effectiveness of a mobile compression device (ActiveCare+S.F.T.®; Medical Compression Systems, Inc., Or Akiva, Israel) with or without aspirin compared with current pharmacology protocols for venous thromboembolism prophylaxis in patients undergoing elective primary unilateral lower extremity joint arthroplasty.

A multicenter registry was established to capture the rate of symptomatic venous thromboemboli following primary lower extremity joint arthroplasty in 3,060 patients from ten sites including knee arthroplasty (1,551) or hip arthroplasty (1,509). All patients were eighteen years of age or older with no known history of venous thromboembolism, coagulation disorder, or solid tumor. Use of the compression device began peri-operatively and continued for a minimum of ten days. Patients with symptoms of deep venous thrombosis or pulmonary embolism underwent duplex ultrasonography and/or spiral computed tomography. All patients were evaluated at three months post-operatively to document any evidence of deep venous thrombosis or pulmonary embolism.

Of 3,060 patients, twenty-eight (0.92%) had venous thromboembolism (twenty distal deep venous thromboses, three proximal deep venous thromboses, and five pulmonary emboli). One death occurred with no autopsy performed. Symptomatic venous thromboembolic rates observed in lower extremity joint arthroplasty patients using the mobile compression device were non-inferior (not worse than) at a margin of 1.0% to rates reported for pharmacological prophylaxis, including warfarin, enoxaparin, rivaroxaban, and dabigatran except in the knee arthroplasty group where the mobile compression device fell short of rivaroxaban by 0.06%.

Use of the mobile compression device with or without aspirin for patients undergoing lower extremity joint arthroplasty provide a non-inferior risk for developing venous thromboembolism compared with current pharmacological protocols reported in the literature.

The concept under discussion is curious and central to our work: is patient dissatisfaction with modern TKA really a “growing problem”? Could it be, that as our technique and technology have improved function and durability, that surgical results have become worse????

A disappointing percentage of patients polled from a distance are less than fully satisfied with the results of their surgery. Why does this surprise us as surgeons?

This problem needs to be untangled. First, these studies ask patients blankly if they are satisfied with their surgery, generally and with respect to specific criteria (e.g. activities of daily living). Neither the patients nor their radiographs have been evaluated. Undoubtedly, some dissatisfied patients will have arthroplasties that would be assessed as less than perfect by a comprehensive evaluation that might include stability testing, range of motion and radiographs of patellar tracking, including CT examination for rotational positioning of components. Some will have suffered the recognised complications of surgery such as chronic regional pain syndrome and infections which, while treated, often yield poor results. Surgeons all too often abandon a systematic and comprehensive evaluation, almost dismissing patients who complain.

A second group will be disabled due to physical factors extrinsic to the arthroplasty: polyarthritis, deconditioning and medical comorbidities. Others suffer depression and are disappointed that life never improved after the arthroplasty.

Thirdly, another group will have knees that could not technically have been any better, but who are still dissatisfied with the result. Some had expectations that exceeded the capability of current technology to reproduce knee function. Their surgeons failed to convey the potential of arthroplasty to make things “normal” in a way that the patient could incorporate. Other patients may have submitted to surgery prematurely, before arthritis and knee dysfunction, had reached the point where arthroplasty represents an improvement.

The concept of a “growing problem”, has more to do with the disjunction between rapidly accelerating public expectations (fueled by modern medicine) and the more modest rate of progress in technology, technique and education. Happy patients tend to be satisfied and there are a great many factors that determine happiness.

Assessment depends on tools for measurement. Surgeons have struggled honestly to develop tools that could help assess which prostheses and techniques were superior, to make wise choices in developing techniques and implants. Many of the original clinical assessment tools have been challenged as invalid. Newer more comprehensive tools have been developed. The “evidence based” movement, and rejection of some clinical tools, represents a shift in power in clinical medicine that has “enabled payers, purchasers, and governmental authorities to use their financial clout to alter the practice of medicine.” (http://www.ahrq.gov/research/findings/evidence-based-reports/jhppl/rodwin.html)

This information is a call for practitioners to evaluate dissatisfied individuals compassionately and objectively and for investigators to evaluate the entire problem exhaustively. Skepticism is appropriate when this message is a glib pretext for commercialisation and/or for denigration of the role of arthroplasty in the lives of our patients. It is a call to improve, not abandon our craft.

“Expert opinion” is the lowest totem on the academic pole and yet, “evidence based” medicine does not always provide us answers for the particular, the unusual clinical problem. Well-controlled studies are precisely that: “well-controlled”. Life may be randomised, but falls short of being “well-controlled”.

The challenge and honor of moderating a panel of experienced and articulate colleagues is to bring out “how they think” and how they formulate a plan for complex cases. The panel members are not only experienced practitioners, but they are the authors of studies that shape our profession. What are the limits to the studies they have published? What insight can they provide us to help understand “level 1” data more astutely? What biases and assumptions support their methods? Nothing achieves that with greater clarity than presentation of complex cases to an accomplished panel.

Several ordinary clinical problems are presented to establish current practice, followed by the unexpected outcomes to illustrate how experts deal with adversity.

Fifteen-year survivorship studies demonstrate that total knee replacement has excellent survivorship, with reports of 85 to 97%. However, excellent survivorship does not equate to excellent patient reported outcomes. Noble et al. reported that 14% of their patients were dissatisfied with their outcome with more than half expressing problems with routine activities of daily living. There is also a difference in the patient's subjective assessment of outcome and the surgeon's objective assessment. Dickstein et al. reported that a third of total knee patients were dissatisfied, even though the surgeons felt that their results were excellent. Most of the patients who report lower outcome scores do so because their expectations are not being fulfilled by the total knee replacement surgery.

Perhaps this dissatisfaction is a result of subtle soft tissue imbalance that we have difficulty in assessing intra- and post-operatively. Soft tissue balancing techniques still rely on subjective feel for appropriate ligamentous tension by the surgeon. Surgical experience and case volume play a major role in each surgeon's relative skill in balancing the knee properly.

New technology of “smart trials” with embedded microelectronics, used in the knee with the medial retinaculum closed, can provide dynamic, intra-operative feedback regarding quantitative compartment pressures and component tracking. While visualising a graphical interface, the surgeon can assess the effect of sequential soft tissue releases performed to balance the knee. These smart trials also have embedded accelerometers used to confirm that one is balancing a properly aligned knee and to provide the option of doing small bony corrections rather than soft tissue releases to obtain balance.

A multi-center study using smart trials is demonstrating dramatically better outcomes.

Lavage and preparation of cancellous bone surface is essential to ensure adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA.

Computer navigation is an attractive tool for use in total knee arthroplasty (TKA), as it is well known that alignment is important for the proper function of a total knee replacement. Malalignment of the prosthetic joint can lead to abnormal kinematics, unbalanced soft tissues, and early loosening. Although there are no long term studies proving the clinical benefits of computer navigation in TKA, studies have shown that varus alignment of the tibial component is a risk factor for early loosening.

A handheld, accelerometer-based navigation unit for use in total knee replacement has recently become available to assist the surgeon in making the proximal tibial and distal femoral cuts. Studies have shown the accuracy to be comparable to large, console-based navigation units. Additionally, accuracy of cuts is superior to the use of traditional alignment guides, improving the percentage of cuts within 2 degrees of the desired alignment.

Because the registration is based on the mechanical axis of the knee, anatomic variables such as femoral neck-shaft angle, femoral length, and presence of a tibial bow do not affect the results. The handheld aspect of this navigation unit allows its use without additional incisions or array attachment. Furthermore, the learning curve and usage time is minimal, supporting its use in primary TKA.

Total knee arthroplasty causes unresolved pain and swelling in about 10% of patients despite good alignment, ligament balance, and fixation. Metal sensitivity becomes more common in total knee patients as time passes, wear continues to be a clinically relevant issue, loosening increases in frequency with time, and infection continues to plague implant surgery. Ceramic bearing surfaces address all of these issues. New technologies make possible stronger, more flexible ceramic materials, and one ceramic in particular (magnesia-stabilised zirconia) is especially interesting because of its ability to accept a commercially pure titanium porous coating. These materials do not release metal debris or ions, wear is reduced by a factor of three, and biofilm formation is reduced by a factor of three or more when compared with cobalt-chromium.

After clearing regulatory requirements, this new ceramic technology is likely to advance our solutions to many of the most important clinical problems in knee arthroplasty.

Obtaining adequate exposure is key to optimising outcomes in revision total knee arthroplasty. Goals of the exposure include protecting the extensor mechanism, safe removal of the components that are in place and implantation of the revision components. Challenges to these goals include prior skin incisions, arthrofibrosis, and patella baja.

Choosing a skin incision is the first important step. The blood supply to the skin is predominantly derived MEDIALLY and thus the most LATERAL skin incision that works for obtaining exposure is selected. If skin flaps are required, they MUST be full thickness as the blood supply to the skin runs deep just over the fascial layer and partial thickness flaps risk skin necrosis. Avoid acute angles between old skin incisions of <60 degrees and skin bridges, if necessary, must be at least 6cm in width.

The work-horse of revision TKA is the medial parapatellar approach. It includes a generous medial release that allows the surgeon to externally rotate and deliver the tibia by pivoting on the extensor mechanism. An anterior synovectomy is then performed to re-establish the medial and lateral gutters followed by re-establishment of the space behind the patellar tendon to free it from the proximal tibia and finally subluxation of the patella (preferable to formal eversion). A lateral release (or peel of the soft tissue off of the lateral side of the patella) is a final step to mobilise the extensor mechanism (if required). After the components are removed, a posterior capsulectomy is performed followed by re-establishment of the flexion space behind the femur further enhances tibial exposure for both bony preparation and revision component implantation.

If the above maneuvers are performed, and exposure is still inadequate, the easiest way to improve exposure is by performing a quadriceps snip. This is an oblique, apical extension of the arthrotomy ACROSS THE PATELLAR TENDON (NOT in the muscle; it is hard to repair if performed in the muscle). It is repaired side to side with no need to alter post-operative physical therapy and heals reliably.

The V-Y Quadricepsplasty is a proximal release of the extensor mechanism; essentially perform by connecting the apical extension of the medial parapatellar arthrotomy with a lateral release across the quadriceps tendon. It is classically indicated for patients with extensor mechanism contracture where the surgeon wishes to lengthen it. It usually results in increased flexion at the expense of an extensor lag and is used rarely in contemporary practice.

Tibial Tubercle Osteotomy is a distal release of the extensor mechanism that is most useful for accessing the canal to remove long-stemmed cemented tibial components. It is a coronal osteotomy made from the medial side of the tubercle that is usually made 5–8 cm in length, tapering from approximately 1cm thick proximally to 5mm distally.

In TKA, prosthetic femoral and tibial implants must be symmetrically placed and matched in the mechanical axis and the ligament gaps must be correctly balanced. The collateral ligaments are the key guide, as they arise from the epicondyles of the distal femur, are perpendicular to the AP axis of Whiteside, and are coincident with the transtibial axis of the proximal tibial surface. A perpendicular bisection of the transtibial axis creates the AP axis of the tibia which is coincident in space with the AP axis of Whiteside (Berger). Measured distal femoral resection targets including TEA, AP axis of Whiteside, and 3 degrees external to the posterior condylar axis works because the stout posterior cruciate ligament limits laxity in flexion, allowing for the anatomical variation of these landmarks to be accommodated. The Insall, Ranawat gap balancing methods work to balance the knee in flexion, often matching the results of a measured resection, but guaranteeing a symmetrically balanced flexion gap. Distal femoral internal rotation can result if the medial collateral is over-released, but experience has shown this not to be a problem if the gaps are well balanced. Tibial tray position must be placed coincident with the AP axis of the tibia, which also is coincident with Akagi's line (line from medial margin of patellar tendon to center of the posterior cruciate ligament). The surgeon can make a line from the AP axis of Whiteside to the anterior tibial which matches the AP tibial axis.

Achieving a primary outcome with revision UKR is possible but it depends on an understanding of the main failure modes and avoiding the obvious pitfalls. The most common failure mode in the long term is lateral compartment progression at 2.5% at 28 years. The most common failure overall is misdiagnosis of a painful radiolucency leading to unnecessary revision.

There are a number of potential pitfalls:

Do not revise for unexplained pain. 75% of patients will go on to fail because of continuing pain. A distinction must be made to differentiate between a physiological radiolucency (with a narrow lucency accompanied by a sclerotic margin which is normal) and a pathological radiolucency (with a poorly defined lucency without surrounding sclerotic margin which is indicative of loosening and/or infection)

Femoral loosening can present with subtle findings. Flexion/extension views are helpful to diagnose this problem.

Wear can be a problem with fixed bearing in the second decade and can present with subtle findings. Infection can present with contralateral compartment joint space narrowing.

The approach and exposure is usually straightforward and component removal is generally easy. Tibial resection is undertaken referenced from the normal lateral condyle removing 10mm of bone. Femoral preparation is generally straightforward but care must be taken to dial in correct rotation in the absence of the posterior medial condyle which was resected in the first operation. Generally a CR or PS primary implant is used with 2–4mm extra polyethylene thickness than is used in primary case.

Revision for infection and stress fracture led to difficult revisions where revision components are usually required.

The results for Revision UKR approach those of a primary procedure in all cases except revision for unexplained pain, infection and a stress fracture.

Complications involving the knee extensor mechanism occur in 1% to 12% of patients following total knee arthroplasty (TKA), and have negative effects on patient outcomes. While multiple reconstruction options have been described, the results in patients with a prior TKA are inferior to those in patients without a TKA. However, optimistic results have been reported by Browne and Hanssen with the use of a synthetic mesh (knitted monofilament polypropylene). In this technique, a synthetic graft is created by folding a 10 × 14 inch sheet of mesh and securing it with nonabsorbable sutures. A burr is then used to create a trough in the anterior aspect of the tibia to accept the mesh graft. The graft is inserted into the trough and secured with cement. After the cement cures, a transfixion screw with a washer is placed. A portal is subsequently created in the lateral soft tissues to allow delivery of the graft from deep to superficial. The patella and quadriceps tendon are mobilised, and the graft is secured with sutures to the lateral retinaculum, vastus lateralis, and quadriceps tendon. The vastus medialis is then mobilised in a pants-over-vest manner over the mesh graft, and secured with sutures. Finally, the distal arthrotomy is closed tightly to completely cover the mesh graft with host tissue. In their series, Browne and Hanssen noted that 9 of 13 patients achieved an extensor lag of <10 degrees with preserved knee flexion and significant improvements in the mean Knee Society scores for pain and function.

Restoration of bone loss is a major challenge of revision TKA surgery. It is critical to achieve of a stable construct to support implants and achieve successful results. Major bone defects of the femoral and/or tibia (AORI type IIB/III) have been reconstructed using impaction grafting, structural allografts or tumor prostheses. The major concerns with structural allograft are graft resorption, mechanical failure, tissue availability, disease transmission, considerable surgical skill required and prolonged operative time. Porous tantalum metaphyseal cones, are becoming the established method of choice to correct large bone defects with several recent studies demonstrating promising results. The high coefficient of friction of these implants provides structural support for femoral and tibial components. The high degree of porosity has excellent potential for bone ingrowth and long-term biologic fixation. Several published series, although with relatively small cohorts of patients, have reported good short-term results with trabecular metal cones for major femoral and tibial bony defects in revision TKA. In a recent study, 16 femoral and 17 tibial cones were reviewed at an average follow up of 33 months (range, 13 to 73 months) the mean Knee Society Score improved from 42 pre-operatively to 83 at last follow up with an improvement of the functional score from an average of 34 to 66 (p<0.0001). Radiological follow up revealed no evidence of loosening or migration of the constructs. No evidence of complications were noted in correlation with the use of trabecular metal cones.

The following checklist is derived from the “Proceedings of the International Consensus Meeting on Peri-prosthetic Joint Infection”, under the auspices of the Musculoskeletal Infection Society, August 1, 2013. It is available online at http://www.msis-na.org/wp-content/themes/msis-temp/pdf/ism-peri-prosthetic-joint-information.pdf.

Pre-Operative: Patient Factors, AODM, Obesity, Smoking, Immunodeficiency, ASA score > 2, Prior open surgery?, MRSA history, EtOH abuse, Malnutrition, Anemia, Recurrent infections

Peri-Operative: Avoid pre-op hospitalization, Chlorhexidine scrub < 6 h pre-op, Hair removal: depilatory or clipper, Appropriate Antibiotic Prophylaxis, Cephalosporin 30–60 min pre-incision, or Vancomycin 1 hour pre-incision, Alcohol based hand emollient after antiseptic soap hand scrub, Limit OR Traffic and Talking!, Double glove, change gloves q2h, ABC bone cement: revisions, high risk patients (immunocompromised), Dilute Betadiner lavage?

Post-Operative: Careful wound closure (Sealed, dry), Sterile, impervious dressing x 24 h, Drain optional, < 48 h, Antibiotic prophylaxis x 24 h, Aggressive drainage hematomas

Infection is still a major problem in implant surgery. Most infections are caused by bacteria that enter the wound at the time of the operation. Although prophylactic antibiotics given intravenously have been shown to be effective if given during the correct time frame, the concentration of local antibiotics in the knee in response to intravenous antibiotics is about 1/3 that achieved in the serum, and the level is transient. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery.

Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and costs analysis shows a remarkable monetary benefit to this effect.

Local antibiotic irrigation during implant surgery is inexpensive, easy, and effective.

The infected joint arthroplasty continues to be a very challenging problem. Its management remains expensive, and places an increasing burden on health care systems. It also leads to a long and difficult course for the patient, and frequently a suboptimal functional outcome. The choice of a particular treatment program will be influenced by a number of factors. These include the acuteness or chronicity of the infection; the infecting organism(s), its antibiotic sensitivity profile and its ability to manufacture glycocalyx; the health of the patient; the fixation of the prosthesis; the available bone stock; and the particular philosophy and training of the surgeon.

For most patients, antibiotics alone are not an acceptable method of treatment, and surgery is necessary. The standard of care for established infection is two-stage revision with antibiotic-loaded cement during the interval period and parental antibiotic therapy for six weeks. Single-stage revision may have economic and functional advantages however. We have devised a protocol that dictates the type of revision to be undertaken based on host, organism and local factors.

Our protocol has included single-stage revision using antibiotic-loaded cement in both THA and TKA. This was only undertaken when sensitive organisms were identified pre-operatively by aspiration and appropriate antibiotics were available to use in cement. Patients with immunocompromise, multiple infecting organisms or recurrent infection were excluded. Patients with extensive bone loss that required allograft reconstruction or where a cementless femoral component was necessary were also excluded.

Our algorithm was validated first in the hip and extended to infected TKA in 2004. This protocol has now been applied in over 100 TKA revisions for infection between 2004 and 2009. Our single-stage revision rate is now over 25%. We continue to see a lower reinfection rate in these carefully selected patients, with high rates of infection control and satisfaction and better functional and quality of life scores than our two-stage revision cases.

Whilst our indications are arbitrary and not based on specific biomarkers, we present excellent results for selective single-stage exchange. A minimum three-year follow up suggests that these patients have shorter hospital stays, higher satisfaction rates and better knee scores. An ongoing evaluation is in place. One-stage revision arthroplasty for infection offers potential clinical and economic advantages in selected patients.

Infection after total knee arthroplasty poses formidable challenges to the surgeon. Once an infection is diagnosed, the identification of the organism and its sensitivity to antibiotics is essential. The host's healing capacity is vital. Optimisation of modifiable comorbidities, supplemental nutrition and cessation of smoking can improve wound healing. Surgical goals include debridement of necrotic tissue and elimination of the dead space. Intravenous antibiotics and a two-stage protocol are the standard of care. At our institution, the first stage is performed with an implant and antibiotic-cement composite. This articulating spacer maintains limb length and tissue compliance. The patient can maintain a functional status between stages. Definitive reconstruction is more readily accomplished with this method in contrast to the static spacer approach. The clinical efficacy of this protocol has been well documented in the literature.

Wound complications are much more common following knee arthroplasty as compared to hip arthroplasty, due in part to the precarious blood supply to the knee, as well as the subcutaneous position of the joint. Many, if not most, infections are related to wound problems, and thus avoiding wound problems is a critical issue in knee replacement surgery.

Many wound problems are avoidable and can be minimised by care to detail by the surgeon. The important steps are to first identify patients at risk and optimally addressing these risk factors. Patient risk factors include: chronic corticosteroid use, diabetes, rheumatoid arthritis, malnutrition, obesity, and smoking.

Soft tissue handling is a second major issue. Minimal incision surgery should be used with great caution for knee replacements since the skin is much less forgiving than in hip replacements. A midline skin incision should be utilised when possible. When multiple incisions are present it is usually advisable to use the lateral most incision through which it is feasible to perform a knee replacement. In rare cases, a soft tissue expander may be used pre-operatively for thin, adherent skin.

Peri-operative steps that can be taken include delaying CPM in high risk wounds, and using a wound vac system in obese or other high risk wounds to minimise persistent drainage. Furthermore, anticoagulation should be used judiciously to avoid prolonged drainage. The final step in salvaging the problem wound is early recognition and aggressive management of wound healing problems. Prolonged, serous drainage is the most common clinical scenario. Drainage that is increasing beyond 5–7 days frequently requires evacuation, irrigation, debridement, and liner exchange. Early aspiration can decompress a hematoma and also rule out infection.

Total knee arthroplasty has been shown to provide relief of pain and improved function; however studies have shown that younger active patients still note limitations in performing higher level activities such as dancing, golfing, skiing and gardening. Journey II BCS is designed to have physiological matching which more accurately reproduces the normal knee anatomy and kinematics. By providing more anatomic restoration of the articular geometry and substituting for both cruciate ligaments, Physiological Matching TKA has been shown, with in-vivo kinematic studies, to better reproduce the normal bending, rollback and rotational motions of knees.

Patient matched instruments are patient specific custom designed cutting blocks. These instruments utilise pre-operative MRI and full leg x-rays to design guides that will position the knee in the desired mechanical alignment. The purpose of these instruments is to increase efficiency and accuracy, and possibly reduce cost.

Efficiency occurs through the elimination of multiple steps compared to the standard operative technique. A single patient matched femoral guide is easily placed and can align the valgus angle with the mechanical axis, and determine the level of resection, rotation, size, and AP position of the implant. A single tibial instrument can determine tibial alignment, depth of resection, slope and rotation. Efficiency also results by eliminating the need for many standard instruments and trays. Implant size is determination pre-operatively so fewer implant trials are necessary.

In summary, this Physiological Matching TKA surgery combines Journey II BCS with patient specific instruments to optimise kinematics, fit and efficiency in order to improve outcomes and patient satisfaction.

Peri-prosthetic distal femoral fractures around total knee replacement is a highly complex reconstructive challenge, particularly in the presence of bone comminution and poor bone quality in elderly patients. With the incidence of peri-prosthetic fractures ranging from 0.3% to 2.5%, this is becoming a common problem. Older patients with concomitant medical issues have a very limited tolerance for prolonged immobilisation.

It is the author's practice to revise, rather that attempt to fix, peri-prosthetic fractures of the knee which are very close to the femoral or tibial implants, particularly when associated with osteoporosis and comminution. When compared to fracture fixation, distal femoral replacement has significantly shorter operative time, less blood loss, and shorter hospital stay. Patients have been shown to recover faster, have fewer complications, and left hospital sooner. The general assumption has been that the use of a distal femoral replacement prosthesis is cost prohibitive in revision total knee settings, however, initial differences in the price of the prosthesis are more than offset by a shortened hospital stay and a more rapid return to pre-fracture level of function.

Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well-fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Often, distal femoral mega prostheses are required to deal with metaphyseal bone loss. Good results have been reported in small series, however, complications, including infection remain concerning, and these implants are incredibly expensive. Although performing a mega prosthesis in the setting of a well-fixed TKA is not unreasonable due to immediate full weight bearing, in my opinion, prosthetic replacement should be limited to cases of failed ORIF (rare), or in cases where fixation is likely to fail (i.e., severe osteolysis distally). For the majority of fractures above well-fixed components, internal fixation is preferred for the main reason that the overwhelming majority of these fractures will heal. Fixation options include retrograde nailing or lateral locked plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension.

Total knee replacement is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKA have changed, with ever younger, more active and heavier patients receiving TKA. Currently, wear debris related osteolysis and associated prosthetic loosening are major modes of failure for TKA implants of all designs.

Initially, tibial components were cemented all-polyethylene monoblock constructs. Subsequent long-term follow up studies of these implants have demonstrated excellent durability in survivorship studies out to twenty years. Aseptic loosening of the tibial component was one of the main causes of failure in these implants. Polyethylene wear with osteolysis around well fixed implants was rarely (if ever) observed.

Cemented metal-backed nonmodular tibial components were subsequently introduced to allow for improved tibial load distribution and to protect osteoporotic bone. Long-term studies have established that many one-piece nonmodular tibial components have maintained excellent durability.

Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intra-operative versatility by allowing interchange of various polyethylene thicknesses, and to also aid the addition of stems and wedges. Other advantages included the reduction of inventory, and the potential for isolated tibial polyethylene exchanges as a simpler revision procedure. However, since the late 1980's, the phenomena of polyethylene wear and osteolysis have been observed much more frequently when compared with earlier eras. The reasons for this increased prevalence of synovitis, progressive osteolysis, and severe polyethylene wear remain unclear, but it is likely associated with the widespread use of both cementless and cemented modular tibial designs. Backside wear between the metal tray and polyethylene has been implicated.

Recent RSA studies comparing fixation of all-polyethylene to modular components has shown that their RSA migration patterns are superior and fixation is in fact better with the all-polyethylene construct. Further, in a recent meta-analysis, all-polyethylene components were equivalent to metal-backed components regarding revision rates and clinical scores.

The promise of modular tibial components affording a simple liner exchange to revise a knee has not borne out in the literature. Several studies have revealed that the effectiveness of isolated tibial insert exchange in revision TKR is of limited value. Isolated tibial insert exchange led to a surprisingly high rate of early failure. Tibial insert exchange as an isolated method of total knee revision should therefore be undertaken with caution even in circumstances for which the modular insert was designed and believed to be of greatest value.

Because of the modularity, extra materials, and extra processing, modular tibial components are significantly more expensive than all-polyethylene components.

Metal-backed tibial components in total knee arthroplasty (TKA) currently dominate the orthopaedic market due to intra-operative flexibility afforded by modularity. Metal-backing was first used in TKA as a method to potentially improve loading distributions over the tibial plateau at the interface between the prosthesis and the supporting cancellous bone. Many studies have compared metal-backed and all-polyethylene tibial components with variable survivorship. We have found decreased clinical survivorship with all-polyethylene Anatomic Graduated Component (AGC) TKA's (Biomet, Inc, Warsaw, Indiana) compared to the non-modular metal-backed design at 10-year follow up, 68% vs 98%, respectively. Loosening or bony collapse beneath the medial plateau accounted for 74% of failures in our AGC all-polyethylene cohort. We hypothesised that all-polyethylene tibial components may lead to increased strains in the proximal tibia with the AGC-TKA design, possibly correlating to osseous overload in the medial compartment and accounting for the increased observed rates of clinical failures in the all-polyethylene group. Finite element studies and our lab studies have shown that metal-backing reduces system stresses in the PMMA bone cement, as well as in the underlying cancellous bone. Overall, in every measurement region with a statistically significant difference in shear strain, higher strain was measured in the all-polyethylene implanted tibiae compared to metal-backed components. Statistically significant increases in strain from 126 μɛ (p=0.0131) to 745 μɛ (p=0.0011) and from 40% (p=0.0010) to 587% (p=0.0054) were seen in the all-polyethylene experimental group. We believe this may correlate with the higher failure rates we have observed in the AGC all-polyethylene cohort compared to the metal-backed cohort from our institution. Other all-poly TKA designs with varied articular congruities may afford improved or equal survivorship to metal backed implants at a reduced cost.

The ultracongruent insert has been used since 1991 beginning with the Natural-Knee, then manufactured by Sulzermedica. It has posterior stabilising ability with the 12.5mm anterior build up with a significantly more congruent articulation. This translates to higher contact areas and theoretically lower wear. The higher central eminence provides some medial lateral stability. This style insert is now available from at least seven different manufacturers.

The first study was reported in the 2000 Journal of Arthroplasty with Hofmann et al., comparing 100 ultracongruent inserts with 100 PCL sparing inserts with an average five-year follow up. Knee scores and range of motion were similar or no dislocations or subluxations were noted. We found this bone sparing since there is no box cut and requires less time for surgery. This insert provided excellent stability in all ranges of motion.

Indications for this surgery are deficiency or compromise of the PCL.

Contraindications are attenuation or absence of either one or both collateral ligaments where a more constrained device is suggested.

Whether to preserve the posterior cruciate ligament in total knee arthroplasty remains a topic of debate. Long term studies out to 20 or more years have shown both posterior-stabilised (PS) as well as cruciate-retaining (CR) total knees to perform well. Studies supporting both sides are abundant, and there are even studies supporting one being superior to the other, and vice versa.

In closer examination of this issue through a recent meta-analysis, the following conclusions can be drawn:

Flexion: mean difference of 2.24, favoring PS designs (p = 0.009)

Patellar crepitance with PS designs can be minimised with design alternations and techniques for patella preparation

Any issues with post impingement can be minimised using PS rotating platform designs

The debate of PS vs CR total knees remains unresolved. There is not a 100% clear advantage. Surgeons should make their choice based on their own clinical outcomes, objectively monitored over the long term. For me personally, the choice is PS.

The selection of venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA) has been controversial. Although the aspirin controversy is presumably resolved, there is no medical evidence for the “optimal” VTE prophylaxis regime for individual patients.

A risk-stratified multi-modal VTE prophylaxis protocol was developed and adopted by consensus. VTE risk factors and bleeding risk factors were categorised into six VTE/bleeding risk levels: (1) pre-operative vitamin K antagonists (VKA) use, (2) bleeding risk factors, (3) hypercoagulable state, (4) pre-operative anti-platelet therapy [clopidogrel use], (5) VTE risk factors, (6) no VTE or bleeding risk factors. The pharmacologic agents used for each risk level were: (1) resume VKA with low molecular weight heparin (LMWH) bridge, (2) pharmacologic agents contra-indicated and mechanical prophylaxis only, (3) VKA for 90 days with LMWH bridge, (4) resume anti-platelet therapy, (5) LMWH in hospital and discharge on aspirin for 90 days, (6) aspirin for 90 days (starting in hospital). In addition to pharmacologic treatment, all patients received multi-modal prophylaxis including early mobilisation, mechanical foot pumps, and neuraxial anesthesia when not contra-indicated. Prior to surgery, a VTE/bleeding risk factor checklist was completed determining the risk level. The intervention cohort included all TJA patients from January 1, 2010 to December 31, 2012. The comparison cohort included all TJA patients from the year prior to implementation of the protocol at the same community hospital. Thirty day all-cause non-elective re-admissions, 30 day same-site re-operations, 90 day VTE events, and protocol compliance were abstracted from the electronic medical record.

The intervention group consisted of 2679 patients (1075 hip arthroplasty patients and 1604 knee arthroplasty patients). The comparison group consisted of 1118 patients (323 hip arthroplasty patients and 795 knee arthroplasty patients). The 30 day all cause non-elective re-admission rate was 2.72% (73/2679) in the intervention group and 4.29% (48/1118) in the comparison group (p=0.0148). The 30 day same-site re-operation rate was 1.38% (37/2679) in the intervention group and 1.25% (14/1118) in the comparison group (p=0.8773). The 90 day VTE event rate was 1.57% (42/2679) in the intervention group and 3.40% (38/1118) in the comparison group (p=0.0007). The VTE rate was higher for knee arthroplasty patients 2.00% (32/1604) than for hip arthroplasty patients 0.93% (10/1075) (p=0.0379). The rate of VTE events was higher for patients that deviated from the VTE protocol 5.03% (10/199) than for all risk groups treated per the protocol 1.29% (32/2481) (p=0.0007).

The risk-stratified multi-modal VTE prophylaxis protocol simultaneously reduced 30 day all-cause non-elective re-admissions and 90 day VTE events. The possible causes for reducing 30 day re-admissions and reducing 90 day VTE events are: (1) reducing bleeding events by using aspirin for VTE prophylaxis in more than 80% of patients, (2) extending VTE prophylaxis to 90 days, and (3) using multi-modal prophylaxis. The risk-stratified multi-modal VTE prophylaxis protocol for total joint arthroplasty is consistent with 9 of the 10 recommendations in the AAOS Clinical Practice Guideline. The risk-stratification checklist provides a standardised tool to assess risks, discuss risks, and make shared decision with patients. Patient treatment that deviated from the protocol had a significantly higher VTE rate (5.03%). Protocol compliance increased each year from 91.1% in 2010 to 94.2% in 2012.

Why are total knees being revised? Aseptic loosening, poly wear, and instability account for up to 59% of revision TKA procedures. Younger and more active patients are placing greater demands on total knee arthroplasty (TKA) implants and international registries have documented a much higher rate of TKA failure in this population. Implant designs utilised in the active patient population should focus on optimisation of long term wear properties and minimising interface stress.

Instability after TKA, often related to technical concerns at the time of the index procedure, accounts for by far the greatest subset of failures, excluding infection, in the early revision TKA patients (<5 years). The inability to achieve a rectangular flexion gap with certain TKA techniques for certain deformities has been documented. The adverse clinical consequence of flexion gap asymmetry has also been published in peer reviewed manuscripts. Techniques should be considered that optimise flexion space balance and enhance mid-flexion stability in active, physically demanding patients.

This surgical demonstration will highlight gap balancing techniques and a new rotating platform TKA system as an option for the active patient population.

Pre-operative planning in revision total knee replacement is important to simplify the surgery for the implant representative, operating room personnel and the surgeon. In revision knee arthroplasty, many implant options can be considered. This includes cemented and cementless primary and revision tibial and femoral components, with posterior cruciate retention or resection, and either with no constraint, varus/valgus constraint, or with rotating hinge bearings. One may also need femoral and tibial spacers, metaphyseal augments, or bulk allograft. It is important to pre-operatively determine which of these implants you may need. If you schedule a revision total knee and ask the implant representative to “bring everything you've got, just in case,” they will have to bring a delivery van full of instruments and implants.

Ideally, the least constraint needed should be used. This requires determination of the status of the collateral ligaments pre-operatively. If there is instability present, use physical examination with confirmation from radiographs. Predict the constraint needed and have the next level as a back-up. Substitution for the posterior cruciate ligament is usually needed for most revisions.

Intra-operative determination of the joint line position is difficult due to lack of anatomic landmarks. Having intact collateral ligaments with an appropriate anatomic joint line position will usually negate the need for increased implant constraint. Radiographically, one can determine the appropriate joint line position relative to the existing femoral component to simplify the surgery.

Pre-operative review of radiographs should determine the amount and location of bone loss. This will help determine if having cementless and/or primary components available can be eliminated. Larger defects may warrant having metallic augments or bulk graft present. Determine if bony deficiencies will mandate use of stems. Most revision knee implants can be conservatively cemented with diaphyseal engaging press-fit stems.

Occasionally, one may not need to revise all components, so the surgeon needs to be familiar with the implants they are revising. Consider having some or all compatible components available.

Excellent pre-operative planning will minimise the need to bring in an excessive number of instruments and implants. It will help assure that the patient has a stable revision knee and simplify the surgery for all participants.

Flexion instability is a well-defined, though often difficult to diagnose, type of TKA instability. It may also complicate posterior stabilised arthroplasties. It is one of three modes of tibial-femoral instability along with: 1. Varus-valgus or coronal plane instability and 2. Instability in the plane of motion that results from either fixed flexion contracture and buckling or recurvatum and collapse. The issues for correction of coronal instability are generally alignment and either ligamentous balance or constraint. For plane of motion instability it is full extension without hyperextension and restoration of extensor mechanism power. The issues for flexion instability are basically balanced flexion and extension gaps.

The diagnosis of flexion instability is made by history and physical examination. These patients, with a more spacious or lax flexion gap, initially do extremely well following surgery, achieving flexion rapidly and comfortably. They progress within months however, to a condition of chronic swelling and tenderness of peri-articular soft tissue, recurrent effusion and a feeling of unease up and down the stairs, as well as getting up out of a chair: anything that stresses the knee in the flexed position.

The diagnosis is confirmed by clinical examination. In gross cases, the patient sitting on the edge of the exam table with the legs dangling and flexed at 90 degrees will first of all close the flexion gap, bringing the tibial component into contact with the posterior femoral condyles when they contract the quadriceps muscle. This vertical motion that precedes extension can be observed. Similarly, if the patient is supine, with the knee flexed to 90 degrees, the examiner may grasp the ankle and with a hand under the thigh, distract the flexion gap and then allow it to close. The travel and the clunk can be appreciated. The standard ‘posterior drawer’ test that is appropriate for the non-arthroplasty knee will only be useful for relatively non-constrained, cruciate dependent prostheses. It will not be useful for flexion instability in the posterior stabilised prosthesis. It is useful to perform this distraction maneuver in flexion, during the arthroplasty with trial components in place to confirm that the arthroplasty is stable in flexion. The common maneuver to assess the flexion gap, of internally and externally rotating the femur to detect medial lateral instability in flexion seems to be less accurate.

The patients at greatest risk for this complication are those presenting for arthroplasty with a fixed flexion contracture. If a measured resection technique is employed without consideration of correcting the tighter extension gap, when a (relatively thinner) poly insert is selected to achieve full extension, it will not be thick enough to stabilise the larger/normal flexion gap. Flexion instability should not be confused with so-called “mid-flexion” instability, which is a poorly defined and much more subtle, clinical entity that has been described in case reports of revision surgery and the cadaver laboratory. Although more conforming articular polyethylene inserts may resolve this problem, even if revision is performed to a more constrained component, the essence of the solution is revision arthroplasty to balance the flexion and extension gaps.

The process by which pathologic scar tissue forms after TKA and restricts functional range of motion is relatively poorly understood. Arthrofibrosis may develop in patients who have normal intra-operative range of motion (ROM). However, passive flexion, extension, or both can become restricted and painful, sometimes several weeks after surgery following an early post-operative period of normal motion. The response to both nonsurgical and surgical treatment is often unsatisfactory. Arthrofibrotic scar contains dense fibrous tissue with abundant fibroblasts. Heterotopic bone is frequently found in patients with arthrofibrosis.

Stiffness may result from inadequate postsurgical pain management or rehabilitation or from a biologic process that causes rapid proliferation of scar tissue. Genetic factors also may play a role, although it is difficult to predict which patients are at increased risk for arthrofibrosis after TKA. Surgical technique also can contribute; oversizing the femoral component, overstuffing the patella, or rotational malalignment can play a role.

Manipulation can be helpful, particularly during the first three months after surgery. However, maintaining motion long term also requires an effective pain management and physical therapy program after manipulation. Arthroscopy may also have a role to remove scar tissue in the suprapatellar pouch and medial and lateral gutters usually between six months and one year after TKA. After one year following TKA, open surgical release or revision surgery is the most effective method to increase motion. However, only modest gains are likely to be achieved and pain may not be improved.

General Principles

Repairs should be immobilised in full extension for 6–8 weeks. Gradual resumption of motion in a hinged brace over an additional 6–8 weeks almost always yields flexion to at least 90 degrees.

Acute tibial tuberosity avulsion

Open repair is best accomplished with a non-absorbable heavy Krackow suture, secured distally around a screw and washer followed by 6–8 weeks of immobilisation. Augmentation with a semitendinosus graft can provide additional structural support.

Acute Patella Tendon Rupture

End to end repair is standard, but re-rupture is not uncommon, so supplemental semitendinosus reconstruction is recommended. The tendon is harvested proximally, left attached distally and passed through a transverse hole in the inferior patella. The gracilis tendon can be harvested and sutured to semitendinosus for additional length, if needed.

Acute Quadriceps Tendon Rupture

These can be repaired end to end with a non-absorbable heavy Krackow suture. A superficial quadriceps fascial turn-down may be a useful adjunct.

Patella Fracture

Treatment depends on the status of the patellar component and the loss of active extension if the component remains well fixed and the patient has less than a 20 degree lag. A loose component and/or >20 degree extensor lag requires ORIF +/− component revision.

Chronic Disruptions

While standard repair techniques are possible, tissue retraction usually prevent a “tension-free” repair. In most chronic disruptions complete allograft extensor mechanism reconstruction is preferable. If the patella itself has not retracted proximally and remains intact, other allograft soft tissues are a viable alternative. All grafts should be repaired tightly with the knee in full extension.

Massive bone loss on both the femur and tibia during revision total knee arthroplasty (TKA) remains a challenging problem. Multiple solutions have been proposed for small osseous defects, including morselised cancellous bone grafting, small-fragment structural allograft, thicker polyethylene inserts, and the use of modular augments attached to revision prosthetic designs. Large osseous defects can be treated with structural allografts, impaction bone-grafting with or without mesh augmentation, custom prosthetic components, and specialised hinged knee components. The metaphyseal area of the distal femur and proximal tibia is a particularly attractive option during revision TKA given that it is usually undamaged and well-vascularised. While multiple reconstructive options have been recommended, porous tantalum metaphyseal cones have the advantage of improved biologic fixation because of their high porosity (75–80%), interconnected pore space, and low modulus of elasticity (3 MPa) similar to that of cancellous bone. Such features allow tantalum cones to fill bone defects while tolerating physiological loads. Indications for porous tantalum metaphyseal cones include patients with Anderson Orthopaedic Research Institute Type 2B or greater defects. The surgical technique is simpler than structural allograft reconstructions with decreased preparation time, resulting in a possible decrease in infection rates. The modularity of porous tantalum metaphyseal cones also allows the surgeon to choose a size and position that best fits the individual defect encountered. Moreover, tantalum cones can be used with several revision systems. Short-term clinical follow up indicates that porous tantalum metaphyseal cones effectively provide structural support with the potential for long-term biologic fixation and durable reconstructions.

Despite our best efforts, occasionally, certain patients will have multiply operated, failed reconstructions after TKA. There are situations where further attempts at arthroplasty are unwise, for example, chronic infections with multiple failed staged reconstructions. A careful pre-operative evaluation of the patient is critical to guide decision-making. An assessment of medical comorbidity, functional demands, and expectations is important. Regarding the extremity, the severity of bone loss, soft tissue defects, ligamentous competency, and neurovascular status is important. The next step is to determine whether the knee is infected. The details of such a workup are covered in other lectures, however, the author prefers to aspirate all such knees and obtain C reactive protein and sedimentation rates. For equivocal cases, PCR may be helpful. If no infection is present, complex reconstruction is considered. Segmental megaprosthesis and hinged prostheses may be helpful. Often, soft tissue reconstruction with an extensor mechanism allograft or muscle flap is required. Obviously, these are massive undertakings and should be done by experienced surgeons. If a prosthesis is not a good option, other options include definitive resection, knee arthrodesis, or above knee amputation. A careful discussion with the patient about the pros and cons is necessary to allow them to partner with the surgeon in the decision-making. Definitive resections are reserved for minimal to non-ambulators with significant comorbidity that do not desire an AKA. AKA is often the best option, however, it should be noted that the majority of these patients will never ambulate with a prosthesis due to the energy requirements necessary to do so. High complication rates and reoperation rates have been reported with AKA after TKA. Functional outcome studies have generally shown better function with arthrodesis than with AKA. Arthrodesis can be effective and can be accomplished with several methods. If active infection is present, an external fixator is typically chosen. If no infection is present then plating or long intramedullary nailing is considered. Plating requires healthy anterior soft tissues due to the bulk associated with double plating techniques. The highest union rates have been reported with long nails. The author therefore prefers to use long nails after eradicating infection with a staged procedure (interval spacer) rather than to use an external fixator. Union rates are higher with nails, but the risk of re-infection is slightly higher as well. Careful attention to detail is necessary to minimise complications.

Direct Anterior vs Mini-posterior THA with Advanced Pain & Rehab Protocols

Intra-articular Injection Within a Year of THA Predicts Early Revision

Specific Screening of MoM Hip Patients Significantly Increases Revision Surgery

Taper Analysis Supports Retention of Well-fixed Stem in Revision of MoM THA

Variables Influencing Corrosion of Modular Junctions in Metal-on-Poly THR

Lysis and Wear of Large and Standard Metal on Highly Crosslinked Poly

A Decade of Highly Crosslinked Poly in THA: A Review of 1,484 Cases

Wear of Highly Crosslinked Poly with 36mm Heads – 5 Yr Follow Up

Fixation and Wear of Contemporary Acetabulum and Crosslinked Poly at 10 Years

Prospective, Randomised Study of 2 Skin Preps in Reducing SSI after TJA

Diagnostic Threshold for Synovial Fluid Analysis in Late Peri-prosthetic Infection, Diabetes, Hyperglycemia, Hemoglobin A1c and the Risk of Joint Infections

Infection Risk Stratification in THA and TKA

Risk Factors for Infection After THA: Preventable vs Non-preventable

Do Space Suits Increase Contamination and Deep Infection in TJA

Improving Detection of PJI in THA Through Multiple Sonicate Fluid Cultures

Sonication for the Enhanced Diagnosis of Prosthetic Joint Infection

Aspiration During 2-Stage Knee Revision Inadequate for Infection Detection

Revision Rates and Outcomes Related to Duration of TKA Surgery

Does Operative Time Affect Infection Rate Following Primary TKA?

Liposomal Bupivacaine: The First 1,000 Cases in a New Era

Cement Depth and Stem Stability in Revision TKA with Hybrid Fixation

Patient History

This patient is a 59-year-old female who presents with right side hip pain which has gradually progressed over the last 2 years. She describes activity related pain in the right groin radiating down the anterior thigh to the knee. There is also a moderate amount of posterior pain in the ischial region. She is now having pain at night as well as occasional back pain. The patient works as a landscape designer and historically has been quite active participating in yoga, snow skiing, and hiking. These activities have become more limited over the last 12 months. She denies any significant right knee pain and has no radicular complaints.

Prior treatment has consisted of physical therapy on two separate occasions over the last year both for 6-week periods without relief. She uses anti-inflammatories daily but otherwise has not had any injections or surgery on the right hip. A cane is used for long distances and her maximum ambulatory capacity is 2 blocks. She is unable to negotiate stairs easily and has difficulty donning socks and shoes. Overall she describes her activity level as light labour.

She has no significant past medical or surgical history and takes no medications. The patient is allergic to sulfa drugs. She denies tobacco use.

By physical exam she stands 5 feet 4 inches and weighs 150 pounds. Lumbar spine exam shows no tenderness to palpation with negative straight leg raise bilaterally. Right hip exam is consistent with 95 degrees of flexion and 10 degrees extension. Abduction and adduction are 20 degrees and 10 degrees, respectively with 5 degrees of both internal and external rotation. Groin pain is reproduced with passive hip range of motion. Hip flexion and abduction strength are 5/5 with mild tenderness along the greater trochanteric region. Leg lengths are symmetrical. Right knee exam shoes full range of motion with neutral alignment and stability in both the coronal and sagittal planes. Right foot and ankle exam is consistent with normal sensory motor function and palpable dosalis pedis and posterior tibial pulses. X-ray examination demonstrates advanced degenerative changes in the right hip with complete joint space obliteration and early erosive changes in the femoral head. Bone quality shows mild osteoporosis.

Impression: Osteoarthritis Right Hip

Plan: Anterior Approach Right Total Hip Arthroplasty

In the Registry Era, in the Information Age, and with a competitive and expanding marketplace, the focus has been on the prosthetic joint devices. However, a distinction should be made between mechanical failure of a device, failure of an arthroplasty, and the limitations of technology. The patient and the surgeon play central roles in the majority of revisions (failure of an arthroplasty). Analysis of a large United States database indicates that the most common causes of revision are instability/dislocation (22.5%), mechanical loosening (19.7%), and infection (14.8%). Acetabular component position has been linked to higher wear and instability. Increased odds of component mal-position were found with lower-volume surgeons and patients with a higher body mass index. Medical co-morbidities significantly increase the risk for revision within 12 months of surgery. Patient demographics and pre-operative status have been shown to be more important than implant factors in predicting the presence of thigh pain, dissatisfaction, and a low hip score. The most predictive factors were ethnicity, educational level, poverty level, income, and a low pre-operative WOMAC score or pre-operative SF-12 mental component score.

Only a little over a decade ago the vast majority of primary total hip replacements performed in North America, and indeed globally, employed a conventional polyethylene insert, either in a modular version or in a cemented application. Beginning in the early 2000's there was an explosion in technology and options available for the bearing choice in total hip arthroplasty.

Highly crosslinked polyethylene was introduced in 1998, and within a few short years the vast majority of polyethylene inserts performed in North America were manufactured from this material. Globally there was a mixed picture with variable market penetration. Surgeons had seen historically poor results with attempts at “improving” polyethylene in the past and many were hesitant to use this new technology. Many randomised clinical trials have been performed and all have shown to a greater or lesser degree, that indeed the highly crosslinked polyethylene insert has undergone less linear and volumetric wear than its more conventional counterpart. The challenge, however, is as we approached mid-term results, orthopaedic manufacturers began altering the polyethylene to improve wear and improve mechanical strength. Therefore while ten-year and greater data will ultimately be published, the actual polyethylene in use at that time will be a different material. Additionally while wear rates are undoubtedly lower, we are still waiting for long-term results of actual osteolytic lesion development and the effect that highly crosslinked polyethylene will have on this clinical scenario. That being said, with over a decade of clinical experience, unquestionably highly crosslinked polyethylene has truly been a revolution in design, essentially eliminating polyethylene wear as an early failure mode.

During this same decade metal-on-metal implants had seen a significant resurgence in use. Metal-on-metal implants had in-vitro advantages with very low wear rates. They allowed the use of large metal heads and articulations, thereby improving range of motion and stability. Concerns always existed regarding the production of metal ions and the potential for metal hypersensitivity, as well as possible systemic effects. Metal hypersensitivity remains a diagnosis of exclusion with no definitive diagnostic tests to either screen for it, or diagnose it, if suspected. Over the past few years metal-on-metal implant use has dropped significantly, to the point now in 2013, where the only remaining application is resurfacing implants in the younger male patient.

Ceramic-on-ceramic bearings enjoy the lowest wear rates of all currently available hip articulations. Historically there has been concern regarding fracturing of both the inserts and the heads, although current generation ceramic-on-ceramic bearings have a much lower reported fracture rate. The phenomenon of a squeaking articulation remains a concern for both patient and surgeon. Conflicting reports exist on whether this is related to implant malposition or is a function of the bearing itself. As with other bearings, improvements in technology continue to evolve and newer ceramics have recently been introduced and are in clinical practice.

The future will continue to see the evolution of the articulation in total hip arthroplasty. Patients are undergoing total hip replacements at younger ages and clearly have higher demands than seen historically. That being said, two factors will have a major influence on future developments. The tremendous clinical success of highly crosslinked polyethylene should have us all question the need for significant changes in bearing material and the current environment following the multiple issues with metal-on-metal is one of evolutionary, rather than revolutionary, design and introduction.

The initial success of modern total hip arthroplasty can in large part be attributed to the reliable fixation of the femoral component with the use of acrylic bone cement. Early success with cement led to a common pathway of development in North America and the European countries. Much of the early to mid-term research concentrated on refinement of variables related to the methodology and technique of cement fixation. Scandinavian registries were subsequently able to report on improved survivorship with better cementing technique. The net effect has been standardisation towards a small number of cemented implants with good long-term outcomes representing the majority of stems implanted in Sweden, for example.

In North America, during the mid-term development of THA in the late 1980's, the term “cement disease” was coined and the cemented THA saw a precipitous decline in use, now to the point where many American orthopaedic residents are completing training never having seen a cemented THA. Modern uncemented femoral components can now claim good long-term survivorship, perhaps now comparable to cemented fixation. However, this has come at a cost with respect to the premium expense applied to the implant itself as well as lineage of failed uncemented constructs. The last several years have seen a proliferation of uncemented implants, usually at a premium cost, with no demonstrated improvement in survivorship. Osteolysis has not been solved with uncemented implants and cement disease has largely been recognised as a misnomer.

Long-term outcomes of cemented femoral fixation have consistently demonstrated excellent survivorship, even in the younger age group. Cemented stems allow for variable positioning of the stem to allow for better soft tissue balancing, without the need for proximal modularity. Cemented stems are more forgiving and fail less often secondary to a reduced incidence of intra-operative complications, such as peri-prosthetic fracture. Cemented stems tend to be less expensive and also have the advantage of adding antimicrobial agents into the cement. This is important in emerging markets. The next iteration of orthopaedic innovation driven by the emerging markets may indeed be back to the future.

Key Points: The initial success of total hip arthroplasty was based on cemented femoral fixation. Long-term outcomes in the United States demonstrate good results for cemented femoral fixation. Despite this, cemented fixation is not frequently used in the United States. Results from multiple national joint replacement registries demonstrate superior long-term performance of cemented femoral fixation. European countries, perhaps because of the excellent results in the national registries, use cemented femoral fixation more often than not. Cemented femoral fixation is cost neutral if not less expensive and allows for the addition of antimicrobials. Cemented femoral fixation is perhaps easier to perform as the component can be potted in a range of positions as opposed to the position being dictated by the femoral anatomy.

In recent years, cementless stems have dominated the North American market. There are several categories of cementless stems, but in the past 20 years, the two most popular designs in the United States have been the extensively coated cylindrical cobalt-chrome (CoCr) stem and the proximally coated tapered titanium stem, which in recent years has become the most common. The 10 year survival for both stem types has been over 95% with a distinction made on factors other than stem survival, including thigh pain, stress shielding, complications of insertion, and ease of revision. Conventional wisdom holds that proximally coated titanium stems have less stress shielding, less thigh pain, and a higher quality clinical result. Recent studies, however, including randomised clinical trials have found that the incidence of thigh pain and clinical result is essentially equivalent between the stem types, however, there is a modest advantage in terms of stress shielding for a tapered titanium stem over an extensively coated CoCr stem. One study utilising pain drawings did establish that if a CoCr cylindrical stem was utilised, superior clinical results in terms of pain score and pain drawings were obtained with a fully coated versus a proximally coated stem. In spite of the lack of a clinically proven advantage in randomised trials, tapered titanium stems have been favored because of the occasional occurrence of substantial stress shielding, the increased clinical observation of thigh pain severe enough to warrant surgical intervention, ease of use of shorter tapered stems that involves removal of less trochanteric bone and less risk of fracture both at the trochanter and the diaphysis due to the shorter, and greater ease of insertion through more limited approaches, especially anterior approaches. When tapered stems are utilised, there may be an advantage to a more rectangular stem-cross section in patients with type C bone. In spite of the numerous clinical advantages of tapered titanium stems, there still remains a role for more extensively coated cylindrical stems in patients that have had prior surgery of the proximal femur, particularly for a hip fracture, which makes proximal fixation, ingrowth, and immediate mechanical stability difficult to assure consistently. Cement fixation should also be considered in these cases. While the market place and the clinical evidence strongly support routine use of tapered titanium proximally coated relatively short stems with angled rather than straight proximal lateral geometry in the vast majority of cases, there still remains a role for more extensively coated cylindrical and for specific indications.

As an increasing number of young, active, large patients are becoming candidates for total hip replacements, there is an increasingly urgent need to identify arthroplasties that will be durable, highly functional and amenable to possible future successful revision. In an era when cemented femoral stems were the primary implant option, the concept of a surface replacement was attractive and, perhaps, appropriate. However, cementless femoral stems of many designs now provide dependable long-term fixation and excellent, near normal function in patients of all ages, sex and level of activity.

However, a number of issues related to cementless stem fixation could be further improved: Optimisation of load transfer to proximal femur to minimise fracture risk and maximise bone preservation; Elimination of proximal-distal mismatch concerns, including bowed femurs; Facilitation of femoral stem insertion, especially with MIS THA exposures; Facilitation of revision with implants capable of providing durable fixation for active patients

The potential benefits of short stem femoral THA implants include: Ease of insertion; Reproducibility of insertion; Avoidance of issues related to proximal-distal anatomic mismatch or variations in proximal femoral diaphyseal anatomy (e.g. femoral bowing); Facilitation of MIS surgical approaches, especially anterior exposures; Optimisation of proximal femoral load transfer with consequent maximisation of proximal bone preservation.

The purpose of this presentation is to describe the design rationale and characteristics of short (< 115mm) uncemented primary THA femoral stem, to evaluate the clinical and radiographic results of short stems and to discuss the possible drawbacks specific to the use of short stems.

While crosslinked polyethylene has reduced the rate of wear and osteolysis in THA, osteolysis still occurs and taper-corrosion induced wear has become recognised as an increasing problem especially when larger diameter metal bearings are used. Long-term follow up studies of newer polyethylene bearings continue to lag those of ceramic-on-ceramic bearings by several years.

Ceramic-on-ceramic (CoC) bearing surfaces have consistently demonstrated reliable clinical results with when coupled with appropriated designed femoral stems and acetabular shells and have been shown to exhibit virtually no risk of adverse biologic reaction. Further, CoC bearings have not been associated with corrosion-induced adverse tissue reactions that occur with metal taper junctions.

Revisions for squeaking have been associated with specific designs and materials, including the use of a titanium elevated metal rim on the acetabular side, and more flexible femoral components made of a beta-titanium alloy (TMZF) which had thin necks and relatively small tapers.

Multiple clinical studies document excellent long-term survival of CoC bearing couples in young patients with revision for any reason as the primary endpoint. Our own experience with 341 hips in patients under 50 with 2–15 years and average 9.1-year follow up demonstrates a 95% overall survivorship (revision for any reason) at 13 years.

CoC bearings continue to show excellent durability in young, high demand patients with an absence of osteolysis in any case. CoC bearings continue to represent an excellent alternative to bearing couples containing polyethylene.

There are many types and articulating surfaces in acetabular cups. Most of the designs currently available are modular, the liner snapping into a locking mechanism of some type. These modular inserts may be polyethylene, usually highly crosslinked polyethylene, or ceramic. Metal shells used in metal on metal devices are usually of a monoblock design.

The elliptical monoblock design has been available for 20 years and was originally made of Titanium with a compression molded polyethylene liner. Tantalum (trabecular metal) was used as the shell material in the more recent designs and the polyethylene is actually molded directly into the tantalum framework. Monoblock acetabular components have a number of advantages. They do not allow access to the ilium because there are no holes in the socket shell with the monoblock construct. They require no locking mechanism which may increase metallic debris. No back surface liner wear can occur because all motion is eliminated at the liner/shell interface. However, because of this absence of screw holes there is an inability to visualise the floor of the acetabulum and perfect coaptation between the shell and the acetabular floor may not occur. The presence of dome gaps of greater than 1.5mm have been noted in 5% of these components but these have not compromised implant stability and in a review of over 600 cups there has been no change in implant position. The elliptical shape of the cup makes the mouth of the acetabular component 2mm greater than the dome so that an exceptionally strong acetabular rim fit results.

Results with over 258 monoblock cups with a minimum of 10-year follow up (10–15 years) have been excellent (Poultsides, et al.). The incidence of pelvic osteolysis was not seen in any patient in this series. There were 3 revisions for instability but none for mechanical failure. There were three femoral revisions for loosening but the cup was intact and not revised in these patients. Utilising the Livermore measurement method polyethylene wear averages 0.08mm per year (0.06mm-0.13mm) and there have been no revisions for wear. Radiographic evaluation demonstrates stable bony interface in all patients. At minimum 10-year follow up the monoblock acetabular component with compression molded polyethylene confirms the theoretical advantages of this design and results have been excellent. Moen et al. have demonstrated no osteolysis in CT scans in tantalum monoblock cups at a follow up of 10.3 years.

This session will be practically oriented, focusing on important surgical decisions and on technical tips to avoid complications. The panel will be polled concerning individual preferences as regards the following issues in primary total hip arthroplasty: Peri-operative antibiotics/blood management/preferred anesthetic, Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior, less invasive exposures, Acetabular fixation, Tips for optimising acetabular component orientation, Femoral fixation: Indications for cemented and uncemented implants and Role of hip resurfacing, Preferred femoral head size, Choice of bearing surface, Tips for optimising intra-operative hip stability, Tips for optimising leg length, Post-operative venous thromboembolism prophylaxis, Heterotopic bone prophylaxis, Post-operative pain management, rehabilitation protocol, activity restrictions and antibiotic prophylaxis.

Surgical invention to preserve the native hip joint remains a preferred treatment option for hips in young patients with mechanically correctable pathologies prior to the development of significant secondary arthrosis. The two most common pathologies most amenable to joint preservation are hip dysplasia and femoroacetabular impingement. These pathologies sometimes overlap. Untreated acetabular dysplasia of modest severity, if left uncorrected, always leads to arthrosis. Acetabular dysplasia is best treated by periacetabular osteotomy, usually combined with arthrotomy for management of labral pathology and associated cam-impingement, if present. Correction of deformities on the femoral side is now less common and reserved for only the more severe combined femoral and acetabular dysplasias or the rare isolated femoral dysplasia. Pre-operative variables associated with the best long-term outcomes include less secondary arthrosis, younger age, and concentric articular surfaces.

Femoroacetabular impingement has become progressively recognised as perhaps the most common cause of secondary arthrosis. The etiology of impingement is multifactorial and includes both genetic factors and stresses experienced by the hip prior to cessation of growth. Cam impingement can be quantified by the alpha angle as measured on plain radiographs and radial MR sequences. Further, significant cam impingement is clearly associated with the development of osteoarthrosis. Treatment can be performed either by arthroscopic or open femoral head-neck osteochondroplasty. As with hip dysplasia, prognosis following treatment is correlated with the severity of pre-operative secondary arthrosis but unfortunately impinging hips more commonly have some degree of arthrosis pre-op whereas dysplastic hips can become symptomatic with the onset of instability in the absence of significant secondary arthrosis. The scientific basis for the treatment of pincer impingement is less strong. Unlike cam impingement and hip dysplasia, pincer impingement pathology in the absence of coxa profunda has not been correlated with arthrosis and so rim trimming with labral refixation is probably performed more often than is clinically indicated. Similarly, caution should be exercised when considering rim-trimming for protrusion since high central contact pressures due to an enlarged acetabular notch are not corrected by rim trimming.

Overall, joint preserving surgery remains the preferred treatment for hips with mechanically correctable problems prior to the development of significant secondary arthrosis.

The acetabular component is the most troublesome implant. There is more written about acetabular placement than any other anatomical site. The problems are: Maintenance of center of rotation (COR); Coverage of the cup with correct inclination and anteversion; Maintenance of inclination below 50 degrees; Anteversion must be mated to the femur (combined anteversion).

COR is critical for balance of the correct offset and leg length. The inferior-medial metal edge of the cup should lie over the TAL or just proximal to it. No cortical bone of teardrop is palpable.

Coverage: Inclination of the normal bony acetabulum has a mean of 55 degrees (range to 70 degrees) so the posterior-superior edge of the cup may be uncovered in many hips to keep inclination below 50 degrees. 45 degrees is critical for wear and anteinclination. Anteversion of the cup is not independent of the femur (Brown/Callaghan, Hip Society Award paper). Femur anteversion must be known to precisely position the cup. Cup coverage is important here too. The posterior and anterior edges cannot be proud (may need to ream more medial).

Acetabular protrusio is defined radiographically as migration of the femoral head medial to Kohler's line (a line from the lateral border of the obturator foramen to the medial border of the sciatic notch). Protrusio can develop in association with metabolic bone diseases such as osteogenesis imperfecta, Marfan's Syndrome, and Paget's disease, inflammatory arthritis or osteoarthritis, tumors, or result from prior trauma. Acetabular protrusio can cause limited hip motion due to impingement of the femoral neck against the acetabular rim. When protrusio develops in association with osteoarthritis, coxa vara is often also present.

Surgical treatment of acetabular protrusio during total hip arthroplasty should lateralise the center of the hip to its anatomic position. This typically can be achieved with use of a larger, slightly oversized, rim fit cementless acetabular component and medial morselised femoral head bone autograft. In cases with more severe deformity, a reconstruction cage may be required. Alternatively a medialised acetabular shell can be used with a lateralised liner. If coxa vara is also present, standard femoral component position (approximately 1cm above the lesser trochanter) can result in an increase in leg length. Careful pre-operative templating should be performed and may require more distal placement of the femoral component to avoid overlengthening the limb.

Peri-prosthetic fractures of the femur around a THA remain challenging injuries to treat. The Vancouver Classification helps to guide decision making, and is based on fracture location, implant fixation status, and remaining bone quality. It is critical to determine fixation status of the implant, even if surgical dislocation is necessary. Type A fractures involve the trochanters, and are usually due to osteolysis. Revision of the bearing surface and bone grafting of the lesions can be effective. Type B1 fractures occur around a well fixed stem, typically at the stem tip. Internal fixation with laterally based locked cable plates is effective. Optimising proximal fixation is important, typically with locked screws and cables. Allograft struts are probably unnecessary with modern angle stable plates. Type B2 and B3 fractures are treated with revision, either with a fully coated cylindrical or a modular fluted tapered titanium stem. Distal fixation should be optimised, while preserving vascularity to proximal bony fragments. The « internal scaffold » technique has been described with excellent results. Rarely, a proximal femoral replacement is necessary. Careful attention to detail and clear knowledge of stem fixation status is necessary for a good outcome.

Metal on metal bearing surfaces were used frequently until recently because of the potential for decreased wear and the ability to use large femoral heads which can reduce instability. However, data reported in the Australian registry over the past 5 years demonstrated an increase in failure rates compared to metal on polyethylene bearings. In addition, adverse local tissue reactions (ALTR) associated with pseudotumors and destruction of the soft tissue around the joint have led to revision of these implants.

Unfortunately, at the present time there is no optimal management strategy that has been delineated for metal on metal implants because of a lack of evidence. The biologic response to metal on metal implants is usually local but may be systemic. The management of these patients is complex because patients may have pseudotumors and/or elevated metal ion levels and be asymptomatic. In addition, there are a number of intrinsic causes (loosening, infection, iliopsoas tendinitis) and extrinsic causes (spinal disease, trochanteric bursitis) that can be a source of pain.

There is no evidence based approach to manage these patients and no single test should be used to determine treatment. A thorough clinical evaluation is essential and blood tests are necessary to rule out infection. Imaging studies including plain radiographs and a MARs MRI are needed to evaluate either the stability of the prosthesis and to assess for the presence of pseudotumors and soft tissue destruction around the implant. Patients with symptomatic hips and evidence of muscle involvement on MRI require revision. Finally, the clinician must always be aware of the potential for systemic effects which require early and aggressive intervention to limit the adverse response to the metal and the metal bearing.

Corrosion at metal/metal modular interfaces in total hip arthroplasty was first described in the early 1990's, and the susceptibility of modular tapers to mechanically assisted crevice corrosion (MACC), a combination of fretting and crevice corrosion, was subsequently introduced. Since that time, there have been numerous reports of corrosion at this taper interface, documented primarily in retrieval studies or in rare cases of catastrophic failure.

We have reported that fretting corrosion at the modular taper may produce soluble and particulate debris that can migrate locally or systemically, and more recently reported that this process can cause an adverse local tissue reaction. Based on the type of tissue reaction and the presence of elevated serum metal ion levels, this process appears quite similar to adverse local tissue reactions secondary to metal on metal bearing surfaces. While modularity in THR has demonstrable clinical benefits, modular junctions increase the risk of corrosion and the types of adverse soft tissue reactions seen in patients with accelerated metal release from metal-on-metal bearing THRs.

The proximal modular neck in total hip arthroplasty is not a new concept, but there has been a recent resurgence in interest with multiple companies offering proximal modularity. Proponents of neck modularity suggest that inherent advantages include improved soft tissue balancing and decreased risk of dislocation, particularly in cases with difficult anatomy. Favorable results have been reported in DDH and other cases with excessive femoral anteversion, for example. There are numerous theoretical and published negative aspects of proximal neck modularity that should be considered. Modular necks can be an additional source of corrosion and fretting, and specific systems have been recalled over such concerns. There are case reports of dissociation and fracture at the junction. Fracture appears to be a significant issue in some systems. Retroversion of the neck to reduce the chance of dislocation is not necessarily benign with respect to implant fixation and stability, with RSA data suggesting caution in the application of retroverted necks. Modular necks are difficult to dissociate when in-vivo, negating the long-term benefit of modular conversion. Finally, proximal neck modularity significantly increases the cost of the implant, without any documented improvement in long-term outcome.

Modular necks offer limited advantages with significant potential downside. On balance of the evidence, the routine use of modular necks in primary total hip arthroplasty is difficult to justify.

Modular necks arrived in North America in the late 1970s. The purpose was to allow ceramic balls to be attached to metal stems. The advantages of modularity were so obvious that it was universally adopted with almost no untoward consequences.

A double-taper neck was developed in Italy by the Cremascoli Company and was used extensively with few reports of problems.

Recently, problems have been reported not only with double-taper necks, but also with head-neck junction tapers. Something would appear to have changed recently.

Some of these changes were shortening of the taper, lengthening of the neck, version angles were increased, and head sizes bigger than 32mm were introduced. Surface finish on some of the tapers was changed and they were ridged. This produces a better fit for a ceramic ball, but facilitates crevice corrosion with a metal ball.

The author used the original OTI cemented stem with a double-taper neck between 2002 and 2005. It was a cobalt chrome construct. The Cremascoli was a titanium hip. The OTI used the classic Morse taper with cogs for increased rotational resistance.

One hundred forty five stems were inserted. The neck stem taper broke in two cases and dislocated in one. All of these cases had a long neck and long heads and thus produced maximum moment arm. The stem was withdrawn from the market, the taper lengthened and the strength doubled. It was reintroduced in 2007. From 2007 to 2011, the author has done 188 cases, all cemented stems. No taper problems have occurred.

The conclusion is that a properly designed double taper neck does not appear to have a downside. The upside is the ability to change neck length and especially version after head insertion. Leg length and hip centering can, therefore, be fine-tuned as never before. The author continues to use this stem enthusiastically for all cemented cases.

Consecutive patients undergoing primary THA were consented from the practices of 3 arthroplasty surgeons. One surgeon performed all DAA THA's, the other two surgeons performed all posterior THA's. All patients received a similar design of uncemented acetabular and femoral components and were managed with similar pain management and rehabilitation protocols

One hundred twenty patients (60 patients per group) with similar age, sex and BMI as well as similar pre-operative health and function scores were followed. Functional recovery was faster in patients with DAA on the basis of TUG and M-FIM assessed on post-operative days 1, 2, 3 but only TUG remained different at 2 weeks. No differences in TUG, M-FIM, UCLA & Harris Hip scores, SF-12 scores, were observed between the groups at 6 and 12 weeks. Comparison of visual analogue pain scores, LOS, time to return to activities of daily living and surgical complexity also revealed no significant differences. DAA offered a faster post-operative recovery after primary THA compared to the PA. Equivalence was achieved somewhere between 2- and 6-weeks post-operatively.

Gait analysis comparisons reveal similar kinematic gains in the frontal and sagittal planes, with increased motion in the transverse plane with DAA at 6 months. Individual muscle testing showed persistent ER weakness with posterior hips at 3 months.

There has been great enthusiasm over the last few years for the mini-anterior, or, the Direct Anterior (DA) approach. As the title of this session suggests there is a perception that there are features of this approach that result in an unusually rapid recovery with “early” return to a high level of function. There have also been claims of improved implant placement and limb length restoration. This is presumably a result of the use of intra-operative imaging. When originally described, it was stated that the DA permitted THA “without cutting any tendons.” The implication was that the alleged unique recovery was due to this particular feature.

Over the last decade I have used a trans-gluteal, direct posterior (DP) approach. Incision into the ITB is not required and quadratus femoris is preserved. The conjoined tendon, occasionally the piriformis, and rarely the obturator externus are released. Over the last 5 years I have used intra-operative digital radiography to guide the procedure.

A review of published DA results indicates at least clinical equivalence with the DP. Recent publications describing DA technique acknowledge that it is required, in most cases, to release conjoined tendon, and possibly piriformis. Personal communication with DA practitioners suggests even more “posterior release” is required. I will illustrate that the DP is a very close anatomic equivalent of the DA. It is therefore the handling of critical anatomic structures along with the use of image guidance that optimise outcome in THA and not mini-anterior or DA exclusively.

Dislocation remains among the most common complications of, and reasons for, revision of both primary and revision total hip arthroplasties in the United States. Hence, there is great interest in maximising stability to prevent this complication.

Highly crosslinked polyethylene has allowed us to increase femoral head size, without a clinically important increase in wear. As femoral head size increases, stability is augmented, secondary to a decrease in component-to-component impingement, which is theoretically eliminated at head sizes greater than 36mm in diameter (however osseous impingement can still occur). Larger heads sizes also greatly increase the “jump distance” required for the head to dislocate (in an appropriately positioned cup) and eliminate the need for skirts. Hence, large heads have become the mainstay for preventing and treating instability in contemporary practice. Large heads, however, have been shown to have poor performance in patients with abductor insufficiency.

Constrained liners are a tantalising solution to both prevent and treat instability, as they markedly increase the force needed for a dislocation to occur. They have, however, several important negatives that the surgeon must consider before entertaining their use including: –

Increased stresses at the implant bone interface which can increase the risk of loosening or cause catastrophic failure in the early post-operative period

Given the limitations of constrained liners, we have moved to dual mobility articulations in most situations where we would have used a constrained liner in the past, including patients with abductor deficiency. These articulations offer anatomic sized femoral heads that greatly increase the jump distance, without many of the negatives of a constrained liner. While dual mobility is associated with its own concerns and problems (including intraprosthetic dislocation and wear) our initial results suggest that they are a viable alternative to a constrained liner, even in the most challenging situations.

When a constrained liner is used in a non-cemented cup it is advisable to add screw fixation to the cup even if the cup has an excellent press-fit because there is more pull-out pressure on the liner with a constrained cup. It also is necessary for the cup to be in the correct anteversion/inclination. It is not advisable to use a constrained liner to “make up” for poor cup position. The patient can still dislocate and then that will require an open reduction.

Our most common use with constrained sockets is to cement a liner into a well fixed cemented cup. We also will cement the liner into two-stage infections to keep it stable between those operations. Failure with the cemented liner into a non-cemented cup only occurs with poor surgical technique. There is only one correct surgical technique and violation of this can cause disassociation of the liner from the cup or dislocation of the head from the liner. The correct technique is: 1.) Preferably there is no hood on the liner because that can increase impingement. 2.) The liner size must have a press-fit of the liner edge to the edge of the metal shell. This is absolutely critical. The liner size cannot sink into the shell or be proud of the shell. 3.) The liner cannot be tilted in the shell to change anteversion or inclination. 4.) The backside of the polyethylene liner must be roughened with a high speed bur preferably in a spider web design. 5.) The inside of the cup should be roughened with a carbide bit of a high speed drill. The screw holes should be cleared of fibrous tissue. 6.) The cement thickness is not a critical factor and 1–2mm is always sufficient. 7.) Maintain pressure on the liner with one size smaller pusher (28mm for 32 inner diameter liner) until the cement is hard.

This session will present a series of challenging and complex primary and revision cases to a panel of internationally respected hip arthroplasty experts. The primary cases will include challenges such as hip dysplasia, altered bony anatomy and fixation challenges. In the revision hip arthroplasty scenarios issues such as bone stock loss, leg length discrepancy, instability and infection will be discussed. This will be an interactive case based session that at its conclusion should leave the attendee with a more thorough approach to these challenging issues.

Revision of the failed femoral component of a total hip arthroplasty can be challenging. Multiple reconstructive options are available and the operation itself can be particularly difficult and thus meticulous pre-operative planning is required to pick the right “tool” for the case at hand. The Paprosky Femoral Classification is useful as it helps the surgeon determine what bone stock is available for fixation and hence, which type of femoral reconstruction is most appropriate.

Monoblock, fully porous coated diaphyseal engaging femoral components are the “work-horse” of femoral revision and are used in my practice for approximately 70% of reconstructions. These stems are associated with problems, in the following situations: The canal diameter is greater than 18mm; There is less than 4cm available for distal fixation in the isthmus; There is proximal femoral remodeling into retroversion.

When the limits of monoblock stems are exceeded, we use modular tapered femoral components. These stems in general allow for better fixation in short isthmic segments and the bi-body nature allows for independent positioning of the proximal body, which is particularly helpful when the femur has remodeled into retroversion.

Since 1982, we have used extensively porous-coated femoral components. Our oldest series of patients is a consecutive non-selected group of 211 hips that have been followed for a mean of 20 years. Combining the loose and the revised, there is a 3% femoral failure. Currently we are following 8,020 hips with a mean follow up of 7 years (0–29 years). Twenty-six percent of the patients have a follow up visit more than 10 years after surgery. The mean age of at the time of surgery was 62 years old (15–97 years). One percent of hips have been revised most commonly for failure of ingrowth-49, infection-19, and stem fracture-7. We have studied patients with disease processes not originally thought to work well with noncemented techniques, including rheumatoid arthritis, avascular necrosis and patients over 65.

In 422 hips with more than 20 year follow up, 96% remain satisfied, with less pain, and increased function. Ten years after surgery 57% can walk more than 60 min. or unlimited distances. Using survivorship analysis 96% of patients continue to live independently or with their family 10 years after surgery. For those patients not retired at the time of surgery, 58% continue to work 10 years after surgery.

Despite the good results, the main concern is that proximal bone loss secondary to the stress shielding caused by a stiff extensively porous-coated femoral component will lead to difficulty at the time of revision. At a mean 14 years, we have not seen any adverse clinical consequences that can be attributed to proximal stress shielding. Extensive proximal bone loss secondary to stress shielding occurs in 25% of cases. In the remaining 70–75% of cases, lesser degrees of proximal bone loss occur which confirm bone ingrowth.

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid- to long-term outcomes of this implant in femoral revision with bone loss. Seventy-one hips in 70 patients with a mean age of 68.5 years were followed for an average of 10 years. Pre-operative HHS averaged 50 and improved to an average of 87 post-operatively. Seventy-nine percent hips had Paprosky type 3A, 3B or 4 bone-loss and 44% had an associated proximal femoral osteotomy. All stems osseointegrated distally (100%). Two hips subsided >5mm (mean 8mm) but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress-shielding. One stem fractured at its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design.

With cementless porous-coated acetabular replacements, extensive bone loss can occur without affecting implant stability. As a result, the surgeon is frequently faced with re-operating on a well-fixed cementless acetabular component with osteolysis and must decide whether or not to remove a well-fixed porous coated socket. A classification system and treatment algorithm has been developed to aid in management decisions regarding re-operation for polyethylene wear and pelvic osteolysis.

Cases are classified into one of 3 possible categories depending on the radiographic stability of the porous coated shell and the ability to replace the polyethylene liner. Type I case; stable porous coated shell, liner replaceable; Type II case; socket stable, liner not replaceable; Type III case; socket loose, not osseointegrated

Relative Contra-indications for Liner Exchange – Type II Case - Malpositioned socket, Severely damaged shell or lock detail (consider cementing shell in place), Poor track record of the implant, Highly crosslinked polyethylene liner of adequate thickness not available, Ongrowth (as opposed to ingrowth) fixation surface

Treatment Algorithm

Type I Case: Retain well-fixed shell in Type I cases and replace the liner. Debride accessible lytic lesions and graft with allograft chips.

Type II Case: Remove the well-fixed shell in Type II case. Assess defect once the shell is removed. Reconstruction based on the bony defect present. The vast majority can be revised with a larger porous coated socket.

Type III Case: Remove loose socket. Assess defect and reconstruct based on the defect. There is a greater need for more extensive grafting and the use of reconstruction rings with Type III cases.

This treatment algorithm has helped the authors successfully evaluate and treat a large series of patients with polyethylene wear and pelvic osteolysis in association with porous coated acetabular components. The stability of the acetabular component and appropriate knowledge of the implant are important factors that impact surgical management.

Hemispheric, porous-ingrowth revision acetabular components (generally with multiple screw fixation) have demonstrated versatility and durability over 25 years. Jumbo cups (minimum diameter of 62mm in women, 66mm in men, or 10mm larger than the normal contra-lateral acetabulum) are utilised in the majority of revisions with acetabular bone loss, with or without bone grafting, or other augmentation. The popularity of jumbo cups is due to their relative ease of use and the reliability of the result. With up to 20 year follow-up, and failure defined as cup revision for aseptic loosening or radiographic evidence of loosening, implant survival was 97.3% (95% confidence interval [CI], 89.6% to 99.3%) at ten years and 82.8% (95% CI, 59% to 97.6%) at fifteen years. Instability is decreased in association with larger diameter bearings. Revisions associated with wear of non-crosslinked polyethylene increased in the second decade. Crosslinked polyethylene and ultra-porous materials will likely increase both the durability and the utility of jumbo cups.

Hip dislocation and recurrent instability continue to be a major cause of failure despite advances in materials to optimise offset and head size. The most common cause of revision after total hip arthroplasty (THA) remains recurrent dislocation (22.5%). Dislocation rates following revision THA are even higher than primary THA, and can be as high as 27%.

Dual mobility acetabular components were introduced in 1974 by Bousquet to reduce dislocation risk and maintain the low friction concept introduced by Charnley. Dual mobility THA has gained wide acceptance in Europe, but there are still concerns regarding its long-term outcomes in the United States. However, even with noncrosslinked polyethylene and poor implant design, survivorship at 22 years has been shown to be 75%.

Little has been published on modular dual mobility (MDM) THA in the revision setting. During revision THA, the benefits of enhanced stability may outweigh the risks of potential unforeseen complications. We present the early results of MDM revision THAs with a low complication rate. In our series, we had a 1.6% dislocation rate, which is significantly lower than what has been published in the literature. However, we urge caution with its use in off label cases, as one of the dislocations was intraprosthetic upon attempted reduction requiring revision to a constrained liner.

Segmental defects of the acetabulum are often encountered in revision surgery. Many times these can be handled with hemispherical cups. However when larger defects are encountered particularly involving the dome and/or posterior wall structural support for the cup is often needed. In the past structural allograft was used but for the last 12 years at our institution trabecular metal augments have been used in the place of structural allograft in all cases. This talk will focus on technique and mid-term results using augments in association with an uncemented revision shell.

The technique can be broken down into 6 steps outlined below: 1. Exposure, 2. Reaming, 3. Trialing, 4. Augment Inserted, 5. Cup Insertion/Stabilization, 6. Trial Reduction/Liner Cementation

A recent study was undertaken to assess the mid-term results of this technique. We prospectively followed the first 56 patients in whom these augments were utilised in combination with a trabecular metal acetabular component in our unit. Details of this study will be presented.

The median follow up of the surviving patients was 110 months (range 88–128 months). Survivorship of the augments at 10 years was 92.2% (95% CI: 97.0–80.5%). In one case the augment was revised for infection and in 3 for loosening. In 1 of the revised cases there was a pre-operative pelvic discontinuity, the other 2 discontinuities in the series were not revised and remain asymptomatic.

Stabilisation of a chronic pelvic discontinuity with a posterior column plate with or without an associated acetabular cage sometimes results in persistent micromotion across the discontinuity with late fatigue failure and component loosening. We believe that these chronic discontinuities are really chronic fracture non-unions incapable of healing. Acetabular distraction offers an alternative technique for reconstruction in cases of severe bone loss with an associated pelvic discontinuity.

We describe the technique of acetabular distraction with porous tantalum components and evaluate its survival, function and complication rate in patients undergoing revision surgery for chronic pelvic discontinuity.

Between 2002 and 2006, we treated 28 patients with a chronic pelvic discontinuity acetabular reconstruction using acetabular distraction. A porous tantalum elliptical acetabular component was used alone or with an associated modular porous tantalum augment in all patients. Three patients died and five patients were lost to follow up before two years. The remaining twenty patients were followed semiannually for a minimum of two years (average, 5.5 years; range, 2–9 years) with clinical pain and walking scores as well as radiographic evaluation for loosening, migration or failure.

In the remaining twenty patients available for follow up, one patient did require re-revision for aseptic loosening. Fifteen patients remained radiographically stable at last follow up. Four patients had early migration of their acetabular component but thereafter remained radiographically stable and clinically asymptomatic. The average improvement using the modified Merle d'Aubigne – Postel pain and ambulation score was 6.6 (range, 3.3–9.6). There were no post-operative dislocations; however, we did encounter one infection, one vascular injury and one bowel injury.

In this series, the use of acetabular distraction with porous tantalum components provides a biologic alternative to cage constructs with more predictable clinical results (average follow up 5.5 years) for reconstruction of severe acetabular defects with associated pelvic discontinuity.

MRSA/MRSE infections appear to be increasing in prevalence and virulence. Prevalence has increased from 2.4% of all infected TJAs in 1975 to 37% in 2006.

In addition work from several centers has shown that cure rates for these infections are far below that of nonresistant organisms. In a recent study from our institution 50 consecutive cases of MRSA/MRSE were treated with two-stage exchange with a Prostalac spacer as the interval operation. Final reinfection rate was 18% which was far worse than the 4% failure reported from our center in MS staph species. This high failure rate is supported by work from other centers.

Clearly with the increasing prevalence and virulence of MRSA/MRSE new strategies are needed. The rest of this talk will focus on 2 different strategies: prevention and treatment.

Prevention strategies can either target carriers or all patients. In a study by Kim et al. carriers were targeted and they reported a 50% reduction in surgical site infections. At our institution a recent program was implemented where all surgical patients were targeted. Results from this will be presented.

While prevention strategies seem quite hopeful new treatment options have to be looked at. Traditionally vancomycin has been the mainstay of local and systemic treatment. Other options currently being explored include such agents as fusidic acid, daptomycin and liniazid. Research is looking at the effectiveness of these agents both locally and systemically.

MRSA/MRSE infections are becoming increasingly difficult to treat. New strategies for combatting these will include both new prevention and treatment strategies as outlined in this talk.

Loss of the abductor portions of the gluteus medius and gluteus minimus muscles due to total hip arthroplasty (THA) causes severe limp and often instability. To minimise the risk of limp and instability the anterior half of the gluteus maximus was transferred to the greater trochanter and sutured under the vastus lateralis. A separate posterior flap was transferred under the primary flap to substitute for the gluteus minimus and capsule. To ensure tight repair, the flaps were attached and tensioned in abduction.

The technique was performed in 11 patients (11 hips) with complete loss of abductor attachment; the procedure was performed in 9 patients during THA and in 2 later as a secondary procedure. Pre-operatively, all patients had abductor lurch, positive Trendelenburg sign, and no abduction of the hip against gravity. The follow up ranged from 16 to 42 months.

Post-operatively, 9 patients had strong abduction of the hip against gravity, no abductor lurch, and negative Trendelenburg sign. One patient had weak abduction against gravity, negative Trendelenburg sign, and slight abductor lurch. One patient failed to achieve strong abduction, had severe limp after 6 months of protection and physical therapy, and was lost to follow up.

Gluteus maximus transfer can restore abductor function in THA, but it is technically demanding and requires careful, prolonged rehabilitation.

The goals of revision arthroplasty of the hip are to restore the anatomy and achieve stable fixation for new acetabular and femoral components. It is important to restore bone stock, thereby creating an environment for stable fixation for the new components.

The bone defects encountered in revision arthroplasty of the hip can be classified either as contained (cavitary) or uncontained (segmental). Contained defects on both the acetabular and femoral sides can be addressed by morselised bone graft that is compacted into the defect. Severe uncontained defects are more of a problem particularly on the acetabular side where bypass fixation such as distal fixation on the femoral side is not really an alternative. Most authors agree that the use of morselised allograft bone for contained defects is the treatment of choice as long as stable fixation of the acetabular component can be achieved and there is a reasonable amount of contact with bleeding host bone for eventual ingrowth and stabilisation of the cup. On the femoral side, contained defects can be addressed with impaction grafting for very young patients or bypass fixation in the diaphysis of the femur using more extensively coated femoral components or taper devices.

Segmental defects on the acetabular side have been addressed with structural allografts for the past 15 to 20 years. These are indicated in younger individuals with Type 3A defects. Structural grafts are unsuccessful in Type 3B defects. Alternatives to the structural allografts are now being utilised with shorter but encouraging results in most multiply operated hips with bone loss. New porous metals such as trabecular metal (tantalum), which has a high porosity similar to trabecular bone and also has a high coefficient of friction, provide excellent initial stability. The porosity provides a very favorable environment for bone ingrowth and bone graft remodeling. Porous metal acetabular components are now more commonly used when there is limited contact with bleeding host bone. Porous metal augments of all sizes are being used instead of structural allografts in most situations.

On the femoral side, metaphyseal bone loss, whether contained or uncontained, is most often addressed by diaphyseal fixation with long porous or tapered implants, modular if necessary. Distal fixation requires at least 4 centimeters of diaphyseal bone and in Type IV femurs, a choice must be made between a mega prosthesis or a proximal femoral allograft. The proximal femoral allograft can restore bone stock for future surgery in younger patients. The mega prosthesis which is more appropriate in the older population may require total femoral replacement if there is not enough diaphyseal bone for distal fixation with cement.

Cortical struts are used for circumferential diaphyseal bone defects to stabilise proximal femoral allografts, to bypass stress risers and to serve as a biological plate for stabilising peri-prosthetic fractures.

Revision hip approaches can be divided into posterior, anterior, transgluteal, and transtrochanteric. The approach chosen is dictated by what needs to be exposed and the approaches with which the surgeon is comfortable.

The posterior approach remains posterior to the gluteus medius and protects the hip abductors. The disadvantage of a posterior approach is post-operative dislocation.

The direct anterior approach is currently enjoying popularity as a primary technique. Surgeons experienced in the primary technique are applying it to revision surgery. The anterior approaches also protect the hip abductors. The disadvantage is poor access to the posterior acetabular column and mobilisation of the femur to gain access to the femoral diaphysis.

Transgluteal approaches split the gluteus medius typically keeping the anterior portion of the medius intact with the vastus lateralis. Proximal exposure is limited by the superior gluteal nerve, which is 4cm above the tip of the trochanter. The disadvantage of the transgluteal approach is difficult access to the posterior acetabular column and occasional abductor weakness.

The advantage of both the anterior and transgluteal approaches is a lower dislocation rate.

All three approaches are acceptable for revisions that only require acetabular rim and proximal femoral exposure. More extensive exposure requires modifications to these approaches or the use of a transtrochanteric approach.

Transtrochanteric approaches are defined by the length of the osteotomy (conventional or extended) and if the vastus lateralis remains attached to the trochanteric fragment (slide).

Distally extended osteotomies improve access to the femur.

Osteotomies without a distal attachment to the lateralis can be retracted proximally thus improving exposure of the ileum.

Surface replacement of the hip was established in the 1970's as a bone preserving alternative to total hip replacement. However, problems with femoral neck fracture, osteolysis, and component loosening led to early failures and an abandonment of the procedure.

The modern generation of hip resurfacing, however, has improved upon past results with new implant designs and materials. Better surgical guides and a short femoral stem allows for more accurate placement of the implants. A metal-on-metal articulation creates a larger diameter bearing and avoids polyethylene wear debris. Also paramount in the recent successes of surface replacement are refinements in surgical techniques, leading to more accurate component positioning, avoidance of neck notching, and an appreciation of the femoral head blood supply. The mid-term results of these newer hip resurfacing devices, coupled with appropriate patient selection and good surgical technique, have been encouraging.

Although more recently surface replacement has come under fire because of the metal-on-metal articulation, the Australian National Joint Registry finds that a certain group of patients has greater survivorship with resurfacing than with total hip replacement. Therefore, the presenter feels that surface replacement arthroplasty is still a viable option in this subgroup of patients. Additionally, the benefits of surface replacement include the preservation of bone, a lower dislocation rate, and potentially a higher activity level.

The recent introduction of digital radiography has enabled a paradigm shift in intra-operative imaging technology. Rather than deal with the cumbersome process of chemical image processing we can now acquire a high quality digital image in a matter of seconds. The functionality approaches that of fluoroscopy, or even a C-arm, however, a digital system can operate with lower radiation, higher resolution, and perhaps most importantly a larger field of view. These features and the greater ability for post-acquisition, digital image enhancement make it very suitable for use during surgery.

The purpose of this presentation is to illustrate the intra-operative technique and share the overwhelmingly positive experience gathered over the past few years.

The current paradigm in total hip arthroplasty (THA) employs use of post-operative radiography for “outcome assessment.” This unfortunately does not allow the surgeon to evaluate the relevant parameters and make necessary adjustments without returning to the operating room. The new paradigm, however, permits intra-operative guidance and “outcome control.” We now have an opportunity to add a “trial radiograph” to our practice of performing a trial reduction. This provides an immediate and complete preview of what the post-operative film will show. There is now an opportunity, during the course of any hip arthroplasty, to optimise component orientation, sizing, apposition, screw position, limb length, and offset, before leaving the operating room. This can be done with minimal intrusion on normal workflow, adding only a few minutes of operating time.

A cemented stem is certainly a good technique to choose for patients 75 years of age or older. In Europe, cemented stems remain prevalent for all ages. In my experience a patient with a cemented stem is comfortable sooner and the leg is also stronger sooner. Cement technique is the most important factor of a cemented stem and with good technique these stems have shown 30 years of longevity in published follow up studies.

Technical points: 1.) Broach only. No reaming. 2.) Maintain hard cancellous bone in the metaphysis. Do not keep weak, loose bone. Brush loose bone away. 3.) Irrigate the femur until the irrigant is clear. Pack it with absorbent gauze (we use Kerlix). 4.) Place a plug and insert cement with a gun and manually pressurise the cement until you feel strong back pressure. 5.) The stem should be press-fit into the cement to force interdigitation of cement into the bone. This means the cement cannot be liquid when the stem is inserted. It must be doughy. 6.) The cement mantle should be 2–3mm circumferentially so pick the correct stem size to permit that. A centraliser will help centralise the tip of the stem in the cement column and prevent the stem being against the edge of the bone which breaks the cement column.

Several disadvantages can be attributed to suture knots in wound closure: they are tedious to tie, may be a nidus for infection and can strangulate tissue. They may extrude through skin weeks after surgery. Additional needle manipulations during knot-tying may predispose to glove perforation. A self-anchoring barbed suture has been developed that requires no knots (or slack suture management) for wound closure. The elimination of knot tying has demonstrated some advantages over conventional wound closure methods. It has demonstrated comparable efficacy for the long term closure of C section wounds. The lack of bulk afforded by the knotless suture proves useful in mid face lift applications where knots are a drawback to traditional suture use and cosmesis is of primary importance.

This type of suture has demonstrated improved “water tightness” in knee arthrotomy closure compared to a standard interrupted suture technique in a cadaver model, has demonstrated reduced time for total surgery by 10% and time for closure by 33%. Use of this suture has been shown to be safe and effective in many other surgical specialties, while proving easier and faster than traditional suturing technique. Its use is highly recommended.

The incidence of clinically significant (Brooker stage 3–4) heterotopic ossification (HO) after THA is 3–7%. Risk factors include male gender, old age, a history of HO, Paget's disease, post-traumatic arthritis, osteonecrosis and rheumatoid arthritis. Prophylaxis for high-risk patients consists of 1) radiotherapy given as one dose of 7–8 Gy either pre-operatively (<4 hours) or post-operatively (within 72 hours) or 2) NSAIDS. Treatment of clinically significant HO includes intensive physiotherapy during the maturation phase of the disease and surgical excision in conjunction with a combination of radiotherapy and indomethacin once the HO has matured. Less invasive surgical approaches may be associated with a reduced incidence of HO.

The prevalence of pseudotumours in patients with large-head metal-on-metal (MOM) THA has been the subject of implant recalls and warnings from various regulatory agencies. To date, there is no consensus on whether ultrasound or MRI is superior for the detection of pseudotumours. Ultrasound is relatively cheap but can be operator dependent. MARS MRI has the advantage of excellent visibility of the soft tissue. However MRI comes at a marked increase cost and takes about twice as long to perform.

At our institution we prospectively compared ultrasound to MRI for pseudotumour detection in an asymptomatic cohort of patients with MOM THAs.

There are several clinical scenarios to consider cementing an acetabular liner into a secure cementless shell including cases of: 1) inadequate capturing mechanism, 2) damaged locking mechanisms, 3) unavailability of the mating polyethylene liner, 4) instability following debridement for wear, 5) instability at the time of femoral side revision, and 6) recurrent dislocation. The last two situations are common scenarios for cementing a constrained liner into a secure shell.

Technique includes: 1) scoring the shell in cases with no screw holes or polished inner shells, 2) scoring the acetabular liner in a “spider web” pattern, 3) pressurising cement into the shell, and 4) inserting a liner that allows 2mm of cement mantle.

Results of Cementing Constrained Liner Into Secure Cementless Shell: Callaghan et al. JBJS 2004 (31 hips, 2–10 year follow up, 2 of 31 failed, Technical considerations - Do not cement proud, Do not cement into a malpositioned shell); Haft et al. J Arthroplasty 2002 (17 hips, Minimum 1 year follow up, 1 of 17 failed, Technical considerations - Do not cement proud)

Results of Cementing Non-Constrained Liners Into Secure Cementless Shell: Beaule et al. JBJS 2004 (32 hips, Mean 5.1 year avg follow up, 4 components revised for loosening); Callaghan et al. CORR 2012 (31 hips, Mean 5.3 year follow up, No revisions)

Fracture of the Ti-Ti modular neck is associated with heavy weight, heavy activity, long modular necks and corrosion of the junction of the neck to the stem. Instruments have been designed that can remove the distal fragment of the fractured modular neck in most cases. These instruments will be demonstrated in this video.

After the neck is removed, the clinician is faced with the decision to remove the stem or to place another modular neck. At present MicroPort (formerly Wright Medical Technology) the company whose modular neck I used, suggests that the female part of the taper (that is the part at the top of the stem) should not be reused if a modular neck (fractured or intact) has been removed.

There is no question that the female taper is changed by having had the modular neck implanted. In most cases of fracture there is severe corrosion at the junction of the neck to stem. Thus, reuse of the taper could have problems and it is understandable that the company does not sanction its reuse. On the other hand, removal of a well-fixed ingrown stem is not without morbidity. In several cases, with patient informed consent, I have left the stem and implanted a new modular neck (either CoCr and Ti alloy) in the damaged taper. We are following these patients closely and it is too soon to make recommendations as to the wisdom of this practice. My strong recommendation is to remove the stem and place a new one.

Dall-Miles cables were introduced in 1985 by Stryker Orthopedics for reattachment after greater trochanteric osteotomy. Prior fixation for greater trochanteric osteotomies was obtained with stainless steel monofilament wire, routinely used by Sir John Charnley. The cables were clearly much stronger. This system consisted of a rectangular four clawed grip and two cables. Two cables were passed thru the claw and around the medial aspect of the upper femur, as well as around the neck or under the collar of a femoral component. A tensioner was devised which would distract opposite ends of one cable, and a powerful squeezing device is used to fix rigidly the cable so that it remained securely held in the claw. In addition, “sleeves” were developed—small rectangular solids made of cobalt-chrome with two parallel holes going from end to end. Two ends of cable are passed thru the holes, pulled tight and locked by using the squeezing tool, the “crimp”, which holds the cables very securely in the desired position.

All of this worked much better than the wiring technique. However, it needed some additional features. The vertical pull of the abductor musculature was not optimally opposed by the cerclage aspects going thru the cross pieces in a largely lateral to medial direction. The vertical pull could relatively easily displace the trochanteric fragment.

I solved this problem by incorporating a secure distal cerclage cable whose tails were taken to and passed thru the lower bar (cross piece) of the grip. The ends of this cable coming thru the lower cross piece are pulled, distracted away very tightly and the lower cross piece is crimped, holding the cable securely. That cable is then passed around the shaft of the femur and cerclaged tightly, using a simple sleeve, tightly crimped.

This technique was published in this citation. Krackow, KA. A Technique for Improved Dall Miles Trochanteric Re-attachment.

Over a four year period of time, 142 consecutive hip revisions were performed with the use of an extended proximal femoral osteotomy. Twenty patients had insufficient follow up or were followed elsewhere and were excluded from the review. The remaining 122 revisions included 83 women and 39 men. Average age at time of revision was 63.8 (26–84) years. Indications for revision were aseptic loosening (114), component failure (4), recurrent dislocation (2), femoral fracture (1) and second stage re-implantation for infection (1).

The extended proximal femoral osteotomy gave easy access to the distal bone-cement or bone prosthesis interface in all cases. It allowed neutral reaming of the femoral canal and implantation of the revision component in proper alignment. Varus remodeling of the proximal femur secondary to loosening was handled with relative ease implementing the osteotomy. Average time from the beginning of the osteotomy procedure to the complete removal of prosthesis and cement was thirty-five minutes. There were no non-unions of the osteotomised fragments at an average post-op follow up of 2.6 years with no cases of proximal migration of the greater trochanteric fragment greater than 2mm, there was evidence of radiographic union of the osteotomy site in all cases by 3 months. Stem fixation with bone ingrowth was noted in 112 (92%) of 122 hips, stable fibrous fixation was seen in 9 (7%) and 1 stem was unstable and was subsequently revised. However, there was an incidence of 7% perforation rate of the femoral canal distal to the osteotomy site during cement removal. This was most prevalent where there was greater than 2cm of cement plug present which was well bonded. When OSCAR was used instead of hand tools or power reamers, there were no perforations in 51 cases. There has been no failure of fixation with fully porous coated stems inserted in the canals where OSCAR had removed cement. Also, the use of OSCAR has allowed us to shorten the osteotomy, thus allowing a longer, intact isthmus to remain so that shorter stems can be used. We highly recommend the use of OSCAR in conjunction with the extended osteotomy for removal of well-fixed distal cement beyond the extended osteotomy site.