Previous work has demonstrated increased implant failure in patients with DDH compared to osteoarthritis with historic methods and implants. This study examines outcomes of modern total hip arthroplasty (THA) techniques using uncemented fixation and cross-linked PE (XLPE) bearings for DDH.

A consecutive series of 879 patients with DDH who underwent primary THA with uncemented components and a XLPE bearing at a single institution between 1999 and 2016 were identified. Mean age at index arthroplasty was 51 years, with 78% females. Mean follow-up was 8 years.

5- and 10-year survivorships free of revision were 98.4% and 98%, respectively. 5- and 10-year survivorships free of reoperation for any reason were 97% and 96%, respectively. Survivorship free of acetabular revision for aseptic loosening was 99.8% at 5 and 10 years, while survivorships free of femoral revision for aseptic loosening were 99.7% at 5 years and 99.5% at 10 years. Survivorship free of reoperation for PE damage (2 liner fractures, 2 rim damage from impingement) was 99.3% at 10 years. There were no revisions for bearing surface wear or osteolysis. 13% of patients experienced complications (4% dislocation, 3.3% wound complication rate). Ten-year survivorship free of reoperation for instability was 99.2%. 8 patients developed infection requiring operation (<1%). 100 patients had a prior pelvic osteotomy (11%), which did not increase rate of complications (p=0.22) or reoperations (p=0.51).

Fixation with modern uncemented implants has dramatically reduced implant loosening in patients with DDH, and the use of XLPE bearings has markedly reduced revision for PE wear/osteolysis in this young patient population, leading to dramatically improved mid/long-term survivorship compared to historic series.

Patients who are actively smoking at the time of primary total joint arthroplasty (TJA) are at considerably increased risk of perioperative complications. Therefore, strategies to assist patients with smoking cessation before surgery have become routine practice. A secondary benefit is the theoretical catalyst for long-term smoking cessation. However, questions remain as to whether patients actually cease smoking prior to the procedure, and if so, how long this lasts postoperatively.

Our high-volume, academic institution documents self-reported smoking status at each clinic visit (at 6-month intervals), as well as at the time of surgery through a total joint registry. As such, all patients who underwent TJA from 2007 to 2018 were identified and grouped as: non-smokers, smokers (regularly smoking cigarettes within 1 year from surgery), and former smokers (those who quit smoking within a year before surgery). Thereafter, smoking status in the postoperative period was assessed, with special attention to the former smokers in order to see who remained smoke-free.

From the 28,758 primary TJAs identified, 91.3% (26,244) were non-smokers, 7.3% (2,109) were smokers, and 1.4% (405) had quit smoking before surgery. Among patients who quit smoking before surgery, only 38% were still abstinent at 9 years from surgery. Conversely, 24% of smokers at the time of surgery eventually quit and 3.1% of non-smokers started smoking over the same time period.

Despite a concerted effort to help patients stop smoking before TJA, an important proportion (7.3%) are unsuccessful. Among those patients who do manage to stop smoking, only a minority (38%) remain smoke-free after surgery. Compared to current smokers, patients who managed to quit before surgery are more likely to remain smoke-free after surgery. These findings highlight that smoking remains a tremendous challenge in contemporary TJA practices. Additional strategies targeting smoking cessation before after surgery are needed.

Tapered fluted grit-blasted modular stems have now become established as a successful method of femoral revision. The success of these stems is predicated on obtaining axial stability by milling the femur to a cone and then inserting the tapered prosthesis into that cone. Torsional stability is gained by flutes that cut into the diaphysis. By having modular proximal segments of different lengths, the leg length, offset, and anteversion can be adjusted after the distal stem is fixed. This maximises the chance for the stem to be driven into the canal to whatever level provides maximum stem stability.

Modular fluted tapered stems have the potential benefits of being made of titanium and hence being both bone friendly and also having a modulus of elasticity closer to that of bone. They have a well-established high rate of fixation. Drawbacks include the risk of fracture of modular junctions and tapers, and difficulty of extraction.

The indications for the use of these implants vary among surgeons, but the implants are suitable for use in a wide variety of bone loss categories. Non-modular fluted tapered stems also can gain excellent fixation, but are less versatile and in most practices are used for selected simpler revisions.

Results from a number of institutions in North America and Europe demonstrate high rates of implant fixation. In a recently published paper from Mayo Clinic, the 10-year survivorship, free of femoral aseptic loosening revision, of a modular fluted tapered stem was 98% and the stem performed well across a wide range of bone deficiencies.

The technique of implantation will be described in a video during the presentation

The main challenges in hip arthrodesis takedown include the decision to perform fusion takedown and the technical difficulties of doing so. In addition to the functional disadvantages of hip fusion, the long-term effects of hip arthrodesis include low back pain and in some cases ipsilateral knee pain. Indications for fusion conversion to THA include arthrodesis malposition, pseudoarthrosis, and ipsilateral knee, low back, contralateral hip problems, and functional disadvantages of ipsilateral hip fusion. When deciding whether or not to take down fusion, consider the severity of the current problem, risks of takedown and likely benefits of takedown. Best results of fusion takedown occur if abductor function is likely to be present. If the abductors are not likely to function well, dearthrodesis may still help, but the patient will have a profound Trendelenburg or Duchenne gait and risk of hip instability will be higher. Abductor assessment can be performed by determining if the abductors contract on physical exam and determining if the previous form of fusion spared the abductors and greater trochanter. EMG and MRI also can be performed to assess the abductors, but value in this setting is unproven. Before dearthrodesis establish realistic expectations: most patients will gain hip motion—but not normal motion, most will see improvement in back/knee pain, but many will become cane-dependent for life.

The main technical issues to overcome involve exposure, femoral neck osteotomy, acetabular preparation, and femoral fixation. Exposure can be conventional posterior, anterolateral or direct anterior with an in-situ femoral neck cut. In complex cases, a transtrochanteric approach is often helpful. The in-situ neck cut is facilitated by fluoroscopy or intraoperative radiograph to make sure the cut is at the correct level and at the correct angle. Be careful not to angle into the pelvis with the cut. Acetabular preparation is more complex because anatomic landmarks often are absent or distorted. Try to find landmarks including ischium, ilium, teardrop, and fovea. Confirm location with fluoroscopy as reaming commences and during reaming. Depth of reaming can be improved by using the fovea (if present) and teardrop on fluoroscopy. Cup fixation is usually an uncemented cup, fixed with multiple screws because bone quality typically is compromised. Femoral fixation is at the surgeon's discretion, recognizing the proximal bone may be distorted in some cases. Postoperative management includes protected weight bearing as needed and heterotopic bone prophylaxis in selected patients.

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: 1. Perioperative antibiotics; 2. Blood management and tranexamic acid protocols; 3. Surgical indications: high BMI patients; 4. Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; 5. Acetabular fixation; 6. Tips for optimizing acetabular component orientation; 7. Femoral fixation: (a) Indications for cemented and uncemented implants. Case examples will be used.; (b) Is there still a role for hip resurfacing?; 8. Femoral material and size: (a) Preferred head sizes and materials in different situations.; (b) Is there a role for dual mobility implants in primary THA?; 9. Bearing surface: present role of different bearings. Case examples will be used. 10. Tips for optimizing intraoperative hip stability; 11. Tips for optimizing leg length; 12. Postoperative venous thromboembolism prophylaxis; 13. Heterotopic bone prophylaxis; 14. Postoperative pain management; 15. Hospital discharge: is there a role for outpatient surgery?; 16. Postoperative rehabilitation protocol: weight bearing, role of physical therapy; 17. Postoperative activity restrictions; hip dislocation precautions; 18. Is there value to physical therapy as outpatient after THA?; 19. Long-term antibiotic prophylaxis for procedures.

Assess union rate, complications, and outcomes of large series of contemporary extended trochanteric osteotomies (ETOs) performed during revision THAs.

From 2003 to 2013, 612 ETOs were performed during revision THAs using 2 techniques. 367 were Paprosky type and 245 were Wagner type. Indications were aseptic loosening (65%), periprosthetic joint infection (18%), periprosthetic fracture (6%), femoral implant fracture (5%), and other (6%). Mean age 69 years, 58% male. Median follow-up 5 years (range, 2.1 to 13 years).

Mean Harris Hip Scores increased from 57 preoperatively to 77 at latest follow-up (p=0.0001). Radiographic union of the extended osteotomy occurred in 98%. There were 9 ETO nonunions. Mean time to union of the distal transverse osteotomy was 5.9 months (range, 1 month − 2 years). Mean trochanteric osteotomy fragment migration prior to union was 3 mm (range, 0–29 mm). Over 1 cm of migration occurred in 7.4%. Intraoperative fracture of the ETO diaphyseal fragment occurred in 4%, and postoperative greater trochanter fractures in 8.8%. Other complications: dislocation in 5.7% and infection in 3.4%. Dislocation occurred in 19 of 462 with ETO migration < 1 cm and 4 of 39 with ETO migration ≥1 cm (p=0.08). Ten year survivorship free of revision for aseptic femoral loosening, free of any component removal or revision, and free of reoperation were 97%, 91%, and 82%, respectively.

The union rate after ETO was high and notable trochanteric migration was infrequent. The most common complication was fracture intraoperatively or postoperatively of the osteotomy fragment.

The moderator will lead a structured panel discussion that explores how to manage challenges commonly found in the multiply revised knee. Topics covered will include: (1) Exposure in the multiply operated knee (when to use quad snip, tibial tubercle osteotomy, other techniques); (2) Implant removal: Tips for removing stemmed implants; (3) Management of bone loss in multiply operated knees (metal cones/sleeves vs. structural allograft vs. particulate graft); (4) Level of constraint (when to use posterior stabilised, constrained condylar, and hinge) and management of instability in multiply operated knees; (5) Preferred management of infection in the multiply operated knee; (6) The extensor mechanism: Preferred deficient patellar bone management; Preferred extensor mechanism deficiency management; (7) When is it time to convert to a salvage procedure (i.e. fusion, resection arthroplasty, amputation)?; (8) Post-operative management: wound management; knee range of motion.

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: 1.) Peri-operative antibiotics; 2.) Blood management and tranexamic acid protocols; 3.) Surgical indications: High BMI patients; 4.) Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; 5.) Acetabular fixation; 6.) Tips for optimizing acetabular component orientation; 7.) Femoral fixation: Indications for cemented and uncemented implants. Is there still a role for hip resurfacing?; 8.) Femoral material and size: Preferred head sizes and materials in different situations. Is there a role for dual mobility implants in primary THA?; 9.) Bearing surface: Present role of different bearings; 10.) Tips for optimizing intra-operative hip stability; 11.) Tips for optimizing leg length; 12.) Post-operative venous thromboembolism prophylaxis; 13.) Heterotopic bone prophylaxis; 14.) Post-operative pain management; 15.) Hospital discharge: Is there a role for outpatient surgery?; 16.) Post-operative rehabilitation protocol: weight bearing, role of physical therapy; 17.) Post-operative activity restrictions; hip dislocation precautions; 18.) Is there value to physical therapy as outpatient after THA?; 19.) Long-term antibiotic prophylaxis for procedures.

The Failed Femoral Neck Fracture

For the young patient: Attempt to preserve patient's own femoral head. Clinical results reasonably good even if there are patches of avascular necrosis. Preferred methods of salvage: valgus-producing intertrochanteric femoral osteotomy: puts the nonunion under compression. Other treatment option: Meyer's vascularised pedicle graft.

For the older patient: Most reliable treatment is prosthetic replacement. Decision to use hemiarthroplasty (such as bipolar) or THA based on quality of articular cartilage, perceived risk of instability problem. In most patients THA provides higher likelihood of excellent pain relief. Specific technical issues: (1) hardware removal: usually remove after hip has first been dislocated (to reduce risk of femur fracture); (2) Hip stability: consider methods to reduce dislocation risk: larger diameter heads/dual mobility/anteriorly-based approaches; (3) Acetabular bone quality: poor because it is not sclerotic from previous arthritis; caution when impacting a pressfit cup; low threshold to augment fixation with screws; don't overdo reaming; just expose the bleeding subchondral bone. A reasonable alternative is a cemented cup.

Serum and blood cobalt (Co) and chromium (Cr) ion levels are used to monitor patients at risk for adverse reaction to metal debris (ARMD) following metal-on-metal (MoM) total hip arthroplasty (THA). However, these levels often do not correlate with the degree of local soft-tissue reaction and damage observed at the time of revision. The purpose of this study was to analyze synovial fluid metal ion concentrations in patients with a failed THA in the setting of an ARMD and determine if these levels can be more predictive of soft-tissue destruction than serum or whole blood levels.

Synovial, blood and serum samples were prospectively collected from patients undergoing revision THA with ARMD (n=29) and those undergoing aseptic revision without ARMD (n=29). There was no difference in mean age (P=0.50), BMI (P=0.18), sex distribution (P=0.18), serum creatinine (P=0.74), or time to revision THA (P=0.13) between the cohorts.

In the AMRD cohort, the components included MoM THA (n=18), hip resurfacing (n=5), dual-modular taper THA (n=4) and MoM and dual-modular taper THA (n=2). At the time of revision THA, 26 (90%) patients in the metal reaction cohort had gross evidence of metallosis in the soft-tissues, the remaining 3 (10%) had evidence of corrosion of the dual taper neck or MoM bearing. In the non ARMD cohort the bearing surfaces included metal-on-polyethylene (n=19) and ceramic-on-polyethylene (n=10). The indications for revision included isolated acetabular loosening (n=11), isolated femoral component loosening (n=11), polyethylene wear (n=5), recurrent dislocation (n=1) and combined femoral and acetabular component loosening (n=1). None had a clinical diagnosis or gross evidence of taper corrosion. Pre-revision, 21 (72%) patients in the metal reaction group had periarticular fluid collections or a mass on MRI. Mean cyst size was 202.9±71.6 cm3 and masses were grouped into Type I (cyst wall <3 mm, n=10), Type II (cyst wall ≥3 mm, n=8) and Type III (mainly solid, n=3).

At the time of revision THA, the mean Co levels were elevated in patients with ARMD compared to those without in synovial fluid (1,833 ppb vs. 12.3 ppb, P=0.008), whole blood (22.6 ppb vs 0.5 ppb, P=0.005)) and serum (19.6 vs. 0.6, P=0.001). Likewise, mean Cr levels were significantly elevated in patients with an ARMD compared to those undergoing revision without in synovial fluid (3,128 ppb vs. 10.3 ppb, P=0.01), whole blood (8.9 ppb vs. 0.5 ppb, P=0.009) and serum (14.1 ppb vs. 0.5 ppb, P=0.005). The synovial fluid Co levels were the most accurate test for detecting pseudotumor (AUC 0.951) and adverse local tissue reaction (AUC 0.826). At a synovial fluid Cr level of 110 ppb, the synovial fluid metal ion analysis was 94% sensitive and 86% specific for pseudotumor formation.

In this prospective study, synovial fluid analysis of metal ion levels was more accurate in predicting the presence and extent of pseudo-tumor or ALTR compared to blood or serum analysis. The addition of synovial aspiration with metal ion analysis may provide another helpful data point when risk stratifying these patients for need for revision THA.

Uncemented component retention with polyethylene (PE) liner and femoral head exchange is commonly used to treat periprosthetic osteolysis. The purpose was to determine long-term implant survivorship, risk factors for aseptic failures, clinical outcomes, and complications following PE liner and head exchange.

We identified 116 hips in 110 patients treated with PE liner and head exchange for osteolysis from 1993 to 2004. The mean age was 58, 64 were women, and mean follow-up was 11 years.

Implant survivorship free from all-cause revisions was 91% at 5-years, 81% at 10-years, and 69% at 15-years. Reasons for re-revision included subsequent conventional PE wear and osteolysis in 7 (6%), aseptic acetabular loosening in 5 (4%), and instability in 5 hips (4%). Mean time to revision for aseptic acetabular loosening was 4 years (range 1 – 7 years). Risk factors for aseptic acetabular loosening included acetabular zones of pre-revision osteolysis, percentage of cup involvement, and size of osteolytic defects. Absolute risk of acetabular loosening was 23% for three zones of osteolysis (Relative Risk (RR) 12, p<0.01), 40% if osteolysis involved more than half the cup circumference (RR 14, p<0.01), and 21% for defects greater than 600 mm² (RR 11, p<0.01). Harris hip scores improved from 77 to 87 (p<0.01). The most common complication was dislocation (16%).

These data quantify risk of subsequent component loosening when well fixed, uncemented implants are retained during operations for osteolysis, and may inform operative decisions regarding shell retention versus revision.

Introduction

The use of stems in TKA revision surgery is well established. Stems off-load stress over a broad surface area of the diaphysis and help protect the metaphyseal interface areas from failure. Stems can provide an area of extra fixation.

The main challenges in hip arthrodesis takedown include the decision to perform fusion takedown and the technical difficulties of doing so. In addition to the functional disadvantages of hip fusion, the long-term effects of hip arthrodesis include low back pain and in some cases ipsilateral knee pain. Indications for fusion conversion to THA include arthrodesis malposition, pseudoarthrosis, and ipsilateral knee, low back, contralateral hip problems, and functional disadvantages of ipsilateral hip fusion. When deciding whether or not to take down a fusion, consider the severity of the current problem, risks of takedown and likely benefits of takedown. Best results of fusion takedown occur if abductor function is likely to be present. If the abductors are not likely to function well, dearthrodesis may still help, but the patient will have a profound Trendelenburg or Duchenne gait and risk of hip instability will be higher. Abductor assessment can be performed by determining if the abductors contract on physical exam and determining if the previous form of fusion spared the abductors and greater trochanter. EMG and MRI also can be performed to assess the abductors, but value in this setting is unproven. Before dearthrodesis establish realistic expectations: most patients will gain hip motion—but not normal motion, most will see improvement in back/knee pain, but many will become cane-dependent for life.

The main technical issues to overcome involve exposure, femoral neck osteotomy, acetabular preparation, and femoral fixation. Exposure can be conventional posterior, anterolateral or direct anterior with an in situ femoral neck cut. In complex cases, a transtrochanteric approach is often helpful. The in situ neck cut is facilitated by fluoroscopy or intra-operative radiograph to make sure the cut is at the correct level and at the correct angle. Be careful not to angle into the pelvis with the cut. Acetabular preparation is more complex because anatomic landmarks often are absent or distorted. Try to find landmarks including ischium, ilium, teardrop, and fovea. Confirm location with fluoroscopy as reaming commences and during reaming. Depth of reaming can be improved by using the fovea (if present) and teardrop on fluoroscopy. Cup fixation is usually an uncemented cup, fixed with multiple screws because bone quality typically is compromised. Femoral fixation is at the surgeon's discretion, recognizing the proximal bone may be distorted in some cases. Post-operative management includes protected weight bearing as needed and heterotopic bone prophylaxis in selected patients.

The moderator will lead a structured panel discussion that explores how to manage challenges commonly found in the multiply revised hip. Topics covered will include: (1) Preferred exposure in multiply operated hip (when to use ETO, when not to use ETO, which type of ETO to use); (2) Implant removal: technical tips for cup removal; (3) Bone loss: favored acetabular reconstruction in severe bone loss (when to use cancellous graft, bulk graft, metal augments); favored acetabular reconstruction methods for different categories of bone loss; favored femoral reconstruction methods for the multiply operated hip; (4) Favored methods of preventing/managing hip instability (large head, dual mobility, constrained implants) in multiply operated hip; (5) When to accept resection arthroplasty as definitive procedure.

The moderator will lead a structured panel discussion that explores how to manage challenges commonly found in the multiply revised knee. Topics covered will include: (1) Exposure in the multiply operated knee (when to use quad snip, tibial tubercle osteotomy, other techniques); (2) Implant removal: Tips for removing stemmed implants; (3) Management of bone loss in multiply operated knees (metal cones/sleeves vs. structural allograft vs. particulate graft); (4) Level of constraint (when to use posterior stabilised, constrained condylar, and hinge) and management of instability in multiply operated knees; (3) Management of bone loss in multiply operated knees (metal cones/sleeves vs. structural allograft vs. particulate graft); (5) Preferred management of infection in the multiply operated knee; (6) The extensor mechanism: Preferred deficient patellar bone management; Preferred extensor mechanism deficiency management; (7) When is it time to convert to a salvage procedure (i.e. fusion, resection arthroplasty, amputation)?; (8) Post-operative management: wound management; knee range of motion.

Two-stage treatment of chronically infected TKA is the most common form of management in North America and most parts of the world. One-stage management has pros and cons which will not be discussed in this lecture.

There is great variation of techniques and timing and little data to definitively support one technique or timing approach vs. another. Most methods are based on empirical success and logic. At the time of surgery, the first step is removal of infected implants. All metallic implants and cement should be removed. The most common places to leave cement behind inadvertently include patellar lug holes, femoral lug holes, and the anterior proximal tibia behind the tibial tubercle. Formal synovectomy should be performed. The next step is typically antibiotic-impregnated spacer placement. There are pros and cons of dynamic and static spacers with no clear evidence of superiority of one vs. another. Dynamic spacers work satisfactorily with mild to moderate bone loss, but more severe bone loss is usually better treated with static spacers and a cast. Most antibiotic spacers are made of methyl methacrylate cement with addition of high-dose antibiotics. In most cases, doses of 4–8 gm of antibiotics per pack of cement are preferred. The type of dosing depends on the specific antibiotic and the type of cement used. The most common antibiotics used are vancomycin and gentamycin. When the femoral canals have been instrumented, antibiotic-impregnated cement wands are usually placed in the medullary canal, as the medullary canals have been shown to have high risk of residual bacteria being present.

The resection interval may vary and there is no clear evidence of a “best” resection interval. Practically speaking, most surgeons use a resection period of 8–16 weeks depending on the type of spacer utilised. During the resection interval, serum markers (ESR and CRP) are followed periodically. One anticipates a decline or normalization of these parameters prior to second stage reimplantation procedure. There has not been a demonstrated advantage to reaspiration of the knee before reimplantation in most circumstances.

At the time of reimplantation, the spacers are removed and the knee is redebrided. The key at the time of reimplantation is to obtain good implant fixation but to also balance this with the potential for manageable extraction of the implants at some later date. Good implant fixation is important because failure rates due to mechanical failure are approximately equal to those of failure due to reinfection by 10 years. It is important to remember that reinfection risk is at least 10% by ten years, and therefore extractability of implants is also important. Post-operative management typically includes IV antibiotics, followed by oral antibiotics until final intra-operative cultures are available.

The results of two-stage reimplantation are reported in many series. Most show approximately 85–95% rate of successful eradication of infection in the first five years. Reinfections, often with different organisms, may occur even late after reimplantation. By ten years after surgery survival free of mechanical failure and infection in most series drops to 80% or less due to recurrent infections and mechanical failures.

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: 1.) Peri-operative antibiotics; 2.) Blood management and tranexamic acid protocols; 3.) Surgical indications: High BMI patients; 4.) Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; 5.) Acetabular fixation; 6.) Tips for optimizing acetabular component orientation; 7.) Femoral fixation: (a) Indications for cemented and uncemented implants. (b) Is there still a role for hip resurfacing?; 8.) Femoral material and size: (a) Preferred head sizes and materials in different situations. (b) Is there a role for dual mobility implants in primary THA?; 9.) Bearing surface: Present role of different bearings. 10.) Tips for optimizing intra-operative hip stability; 11.) Tips for optimizing leg length; 12.) Post-operative venous thromboembolism prophylaxis; 13.) Heterotopic bone prophylaxis; 14.) Post-operative pain management; 15.) Hospital discharge: Is there a role for outpatient surgery?; 16.) Post-operative rehabilitation protocol: weight bearing, role of physical therapy; 17.) Post-operative activity restrictions; hip dislocation precautions; 18.) Is there value to physical therapy as outpatient after THA?; and 19.) Long-term antibiotic prophylaxis for procedures.

Introduction

The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998 and femoral heads larger than 32mm in diameter introduced 2004.

The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against large diameter femoral heads at a minimum of 10 years follow-up.

Introduction

The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998. Numerous publications have reported reduced wear rates and a reduction in particle induced peri-prosthetic osteolysis at short to mid-term follow-up.

The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against 32mm femoral heads or less at a minimum of 13 years follow-up.

The value of joint registries is to (1) provide large scale longitudinal follow-up of classes of implants and individual implants—thereby providing potential for improved performance—and (2) serve as a tripwire for unexpected problem implants which is well appreciated. The purpose of this talk is not to reiterate the value of joint arthroplasty registries, but rather to look at several key findings from joint registries around the world and discuss what these mean for orthopaedic surgery today.

Observation #1: Registries can tell us where the biggest problems are so we can act on them: Example: Early failures—those occurring in the first two years—account for about half of all failures by ten years. Early failures consist of mainly technically related problems and infections. If we can reduce these problems, we can reduce the number of patients having a second surgery after joint replacement by almost half. For one type of early failure (infection), the registry data show rate of infection after THA and TKA has not declined substantially in the last 20 years. We need major innovation in this area to solve this problem. On the other hand, registry data show early failures in older patients after THA are often due to periprosthetic femur fracture: we can solve this problem now with choice of stem fixation or prophylactic wires in high risk patients.

Observation #2: Innovation can and does work! It is not correct to suggest that no new implants have led to improved results. Example: Registry data demonstrate that cross-linked polyethylene bearings have reduced the risk of revision after THA dramatically, especially in younger patients.

Observation #3: Gathering more detailed information, such as patient reported outcomes, at least on limited samples of patients, can provide further insights. Example: Registry data demonstrate much greater variability in clinical outcomes of TKA in younger patients compared to older patients.

Observation #4: Having national registries from different countries provides synergistic information. Example: Combining data from several national registries provides information on performance of femoral heads of different diameter and material that are not available from just one source.

Observation #5: Registries may provide unexpected information that opens unexpected avenues for study. Example: Several registries demonstrate men have a 1.5–2 times higher risk of infection after TKA. We did not know this before. Why is this? Can we reduce it?