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?

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: Perioperative antibiotics/blood management/preferred anesthetics, Surgical approach for primary total hip arthroplasty, Acetabular fixation, Tips for optimizing acetabular component orientation, Femoral fixation, Femoral head size, Bearing surface, Tips for optimizing intraoperative hip stability, Tips for optimizing leg length, Postoperative venous thromboembolism prophylaxis, Heterotopic bone prophylaxis, Postoperative pain management, Postoperative rehabilitation protocol, Postoperative activity restrictions, and Postoperative antibiotic prophylaxis for procedures.

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) 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); (4) Preferred management of infection in the multiply operated knee; (5) When is it time to convert to a salvage procedure (i.e. fusion, resection arthroplasty, amputation)?

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: Perioperative antibiotics/blood management/preferred anesthetics; Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; Acetabular fixation; Tips for optimizing acetabular component orientation; Femoral fixation: Indications for cemented and uncemented implants. Case examples will be used. Is there still a role for hip resurfacing?; Femoral head size: Preferred head sizes and materials in different situations. Is there a role for dual mobility implants in primary THA?; Bearing surface: Present role of different bearings. Case examples will be used.; Tips for optimizing intra-operative hip stability; Tips for optimizing leg length; Post-operative venous thromboembolism prophylaxis; Heterotopic bone prophylaxis; Post-operative pain management; Post-operative rehabilitation protocol: weight bearing, role of physical therapy; Post-operative activity restrictions; Post-operative antibiotic prophylaxis for procedures.

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 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.

Introduction: Over the last 37 years I have performed more than 8000 primary and revision THRs. These include cemented, hybrid, and noncemented types of fixation. There are many preventable complications which include: infection, delayed wound healing, perforation or varus position of the implant, and suboptimal cement technique. Quality of function depends on restoring center of rotation, restoring offset, equal limb length, balancing soft tissue, and adequate pain control. Long-term success depends on durable fixation and reduced wear. Cement fixation into cortico-cancellous bone provides durable fixation.

Discussion: We have a cohort at my practice of 370 total hip replacements. Fifty-three percent were cemented, 25% were hybrid, and 22% were noncemented. In another cohort of 253 cemented THR followed for a 10-year period, only two failures were found. One revision was for dislocation and the other was for loosening. I have found the Interlock system to have a very successful survivorship rate. I believe the reason for superior results is better polyethylene, better patient selection, and better surgical technique. I indicate cemented fixation for patients 60 years and older. I avoid if there is excessive bleeding and in a heavy, active patient.

Introduction: The goal is to avoid letting femoral deformity force suboptimal implant position/fixation. Suboptimal implant position has an adverse effect on hip biomechanics and often on hip function and durability.

Classification: Practical approach to femoral deformities: categorise into 3 main groups: Very proximal, Subtrochanteric, Distal.

Management: Management of distal deformities: Most can be ignored if there is sufficient room to place conventional femoral implant. Management of proximal deformities: Option 1: Use implants that allow satisfactory positioning despite deformity…or… Option 2: Remove the deformity.

Management of subtrochanteric level deformities: These are the most difficult. Problems: Too proximal to ignore, Too distal to bypass.

Main treatment options: Resurfacing THA, Short stem THA, Corrective osteotomy with THA.

Corrective osteotomy with THA: Perform osteotomy at level of deformity, In most cases a corrective osteotomy that creates a transverse osteotomy junction is simplest, Use an implant that provides reliable fixation in the femur (usually uncemented), Use implant that provides fixation of the proximal and distal fragments

Conclusions: Majority of proximal femoral deformities managed with one-stage procedure: Excise deformity and replace with metal, Implants that allow ignoring deformity, Corrective osteotomy.

A) Mastering the Art of Cemented Femoral Stem Fixation

Introduction: Fixation of cemented femoral stems is reproducible and provides excellent early recovery of hip function in patients 60–80 years old. The durability of fixation has been evaluated up to 20 years with 90% survivorship. The mode of failure of fixation of cemented total hip arthroplasty is multifactorial; however, good cementing techniques and reduction of polyethylene wear have been shown to reduce its incidence. The importance of surface roughness for durability of fixation is controversial. This presentation will describe my personal experience with the cemented femoral stem over 30 years with 3 designs and surface roughness (RA) ranging from 30–150 microinches.

Results: Since 1978, three series of cemented THA have been prospectively followed using periodic clinical and radiographic evaluations. All procedures were performed by the author using the posterior approach. Excellent results were noted and Kaplan-Meier survivorship ranged from 90% to 99.5% in the best case scenario at 10–20 year follow-up.

Conclusion: With a properly-designed femoral stem, good cement technique, proper cement mantle, and surface roughness of 30–40 microinches, the cemented femoral stem provides a durable hip replacement in patients 60 to 80 years of age with up to 95% survivorship at 10 to 20 years.

B) Cemented Primary Acetabulum

Introduction: I am going to present a technique of cementing an all-polyethylene socket, a brief review of our clinical experience, and all-polyethylene socket design features. Since 1991, we have been using direct compression molded polyethylene sockets. The minimum thickness of polyethylene is 8 mm. We keep the socket orientation at 45 degrees of lateral opening and 15 degrees of anteversion. The preparation of the socket involves multiple fixation holes with Midas Rex. The bone is cleaned with water lavage and heated cement.

Radiographic Features: The cement/bone interface has been classified into three types on radiographs. Type 1 has a perfect merge of the cement into the cancellous bone in all three zones. Type III interface shows radiolucency in one or more zones.

A commonly asked question is, “is this technique reproducible?” The answer is yes.

Our Data: We have looked at our all-polyethylene socket from 1992 to 1998 and the total number of hips are over 1,000, with a follow-up of 2–8 years. We have not revised a single socket for fixation failure.

Summary: A cemented socket is indicated in patients 60 years and older with a diagnosis of osteoarthritis. Relative contraindications are excessive bleeding, extensive cyst formation, weak cancellous bone such as in rheumatoid, JRA, DDH, and protrusion patients. Cemented THA in patients 60 years and older with DJD and molded all-polyethylene cup have provided the best results in terms of a high degree of reproducibility, high quality of function, and durability.

The goal is to avoid letting femoral deformity force suboptimal implant position/fixation. Suboptimal implant position has an adverse effect on hip biomechanics and often on hip function and durability.

Classification - Practical approach to femoral deformities: categorise into 3 main groups: 1.) Very proximal, 2.) Subtrochanteric, 3.) Distal.

Management of distal deformities: Most can be ignored if there is sufficient room to place conventional femoral implant.

Management of proximal deformities: Option 1: Use implants that allow satisfactory positioning despite deformity…or… Option 2: Remove the deformity.

Management of subtrochanteric level deformities: These are the most difficult. Problems: 1.) Too proximal to ignore, 2.) Too distal to bypass. Main treatment options: 1.) Resurfacing THA, 2.) Short stem THA, 3.) Corrective osteotomy with THA.

Corrective osteotomy with THA: 1.) Perform osteotomy at level of deformity, 2.) In most cases a corrective osteotomy that creates a transverse osteotomy junction is simplest, 3.) Use an implant that provides reliable fixation in the femur (usually uncemented), 4.) Use implant that provides fixation of the proximal and distal fragments.

Majority of proximal femoral deformities managed with one-stage procedure: 1.) Excise deformity and replace with metal, 2.) Implants that allow ignoring deformity, 3.) Corrective osteotomy.

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/blood management/preferred anesthetics; 2. Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; 3. Acetabular fixation; 4. Tips for optimizing acetabular component orientation; 5. Femoral fixation: (a) Indications for cemented and uncemented implants. (b) Role of hip resurfacing; 6. Femoral head size: Preferred head sizes in different situations; 7. Bearing surface: Present role of different bearings; 8. Tips for optimizing intra-operative hip stability; 9. Tips for optimizing leg length; 10. Post-operative venous thromboembolism prophylaxis; 11. Heterotopic bone prophylaxis; 12. Post-operative pain management; 13. Post-operative rehabilitation protocol: weight bearing, role of physical therapy; 14. Post-operative activity restrictions; and 15. Post-operative antibiotic prophylaxis for procedures.

Fixation of cemented femoral stems is reproducible and provides excellent early recovery of hip function in patients 60–80 years old. The durability of fixation has been evaluated up to 20 years with 90% survivorship. The mode of failure of fixation of cemented total hip arthroplasty is multi-factorial; however, good cementing techniques and reduction of polyethylene wear have been shown to reduce its incidence. The importance of surface roughness for durability of fixation is controversial. This presentation will describe my personal experience with the cemented femoral stem over 30 years with 3 designs and surface roughness (RA) ranging from 30–150 microinches.

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.

Perioperative antibiotics/blood management/preferred anesthetics; Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; Acetabular fixation; Tips for optimising acetabular component orientation; Femoral fixation: indications for cemented and uncemented implants, role of hip resurfacing; Femoral head size: preferred head sizes in different situations; Bearing surface: present role of different bearings; Tips for optimising intraoperative hip stability; Tips for optimising leg length; Postoperative venous thromboembolism prophylaxis; Heterotopic bone prophylaxis; Postoperative pain management; Postoperative rehabilitation protocol: weight bearing, role of physical therapy; Postoperative activity restrictions; Postoperative antibiotic prophylaxis for procedures

Prevention: Many periprosthetic femur fractures may be prevented by: good patient follow-up; timely reoperation of lytic lesions if radiographs suggest fracture risk; prophylactic use of longer stemmed implants or strut grafts to bypass cortical defects at revision surgery.

Treatment: Periprosthetic fractures can be treated using an algorithmic approach based on the Vancouver classification system.

Fractures of greater or lesser trochanter (Type A): nonoperative treatment if displacement acceptable and if not associated with lysis; operative treatment if displacement unacceptable or associated with progressive lysis.

Fractures of distal femur well distal to implant (Type C): treat as any other femur fracture, usually operatively; fixation options: plate/retrograde nails.

Fractures around the implant or at its tip (Type B): these fractures almost always require surgery. Nonoperative treatment is associated with high rate of malunion, nonunion, poor results. Treatment is according to fixation status of implant and bone quality.

Well-fixed stem (Type B1): ORIF with cable plate and/or strut grafts; or with locking plate and minimally invasive biologic technique.

Loose stem (Type B2 and Type B3): revise implant to long stem; usually use uncemented distally-fixed implant; occasionally long cemented stem (avoid cement extrusion). In most cases we favor use of a modular fluted tapered stem which provides axial and rotational stability by fixation distal to the fracture.

Principles: obtain fracture stability, implant stability, and optimise conditions for bone healing (use bone grafts, don't strip periosteum)

Highly porous metal surfaces have transformed acetabular revision surgery by providing (1) enhanced friction which potentially provides greater primary fixation, (2) enhanced bone ingrowth potential, (3) enhanced screw fixation options. These characteristics have led many surgeons to use these devices routinely in acetabular revision and have led to an expansion of the indications for porous uncemented hemispherical cups in acetabular revision. Mid-term results suggest that the historical indications for hemispherical cups in revision surgery can be moderately expanded with some implants with these characteristics. In a recent study of 3448 revision total hip arthroplasties, we found porous tantalum cups had a statistically lower revision rate than other materials/designs. Highly porous metals also have provided the options of metal augments to fill selected bone defects—which can both enhance cup fixation and manage bone loss simultaneously. A number of different highly porous metals are now available, and how each will perform is not yet known.

Highly porous metal shells may be used in combination with highly porous metal augments to make up for segmental bone deficiency. Examples will be shown. Finally, highly porous metal shells may be used as a “cup-cage” combination to provide extra initial cup mechanical stability in extreme cases. Examples will be shown.

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

Uncemented Stems: Advantages – Expeditious; Compatible with intramedullary based revision instrumentation; Easy to remove if necessary; By filling diaphysis they help guarantee axial alignment.

Disadvantages - They help off load stress, but how much fixation do they really provide?; They don't fit all canal deformities, and under some circumstances can actually force implants into malalignment; ? potential for end of stem pain.

Cemented Stems: Advantages - Cemented stem adds fixation in fresh metaphyseal and diaphyseal bone; Proven 10-year track record; Allow the surgeon to adjust for canal geometry abnormalities.

Disadvantages - More difficult to remove if required; They don't fill the canal so they don't guarantee alignment as well under most circumstances.

What are the data on obesity and THA risk? Which complications are elevated? If you decide on surgery, how can you minimise complications? These are timely questions because the rates of obesity are rising in the US and in many other parts of the world.

Does obesity increase risk of THA complications? Answer: yes: at least for some complications.

Complications which are increased: infection, wound healing, nerve injury; possibly: dislocation, periprosthetic fractures. The data are mixed on whether aseptic loosening and/or bearing surface wear problems are increased in the obese. Higher BMI may be offset by lower activity levels, particularly in a congruent joint such as the hip.

Outcomes of THA in obese: Lower function scores and activity scores compared to nonobese. But good pain relief and the preoperative to postoperative change in functional scores is similar to non-obese.

Is there a critical BMI threshold above which complications become unacceptable? Several studies show BMI ≥40 associated with strong risk of complications. One study from Mayo Clinic on patients with BMI ≥50 showed a 39% surgical complication rate, a 12% medical complication rate, and a high mortality rate in the several years after THA. Individualise operative decisions based on risk/benefit analysis for each patient.

If you decide to operate, how can you minimise risk? Lose weight before surgery by diet: often ineffective, but worth trying. Lose weight before THA with bariatric surgery: effective in producing weight loss, but beware of the “malnourished” obese patient

In surgery: care with patient positioning, sufficient incision length, greater exposure, avoid sciatic nerve injury, fractures, care with acetabular component positioning, extra drains in subcutaneous tissue and wound compression.

Engage patient in discussion of risks/benefits before surgery: shared decision making.

THA after acetabular fracture presents unique technical challenges. These challenges include bone deformity, bone deficiency, sclerotic or dysvascular bone, non-united bony fragments, pelvic discontinuity, retained hardware, heterotopic ossification, previous incisions, and concerns regarding the sciatic nerve. Despite these challenges, with current treatment methods, a high degree of success can be achieved with modern technology.

Preoperative evaluation for infection - In previously operated acetabular fractures, infection is always a concern. Screening C-reactive protein and sedimentation rate may be performed. If a concern regarding infection is present, the hip may be aspirated; Incisions - In most cases, a previous incision may be utilised. If necessary, an incision may be extended or a new limb can be created and attention should be paid to maintaining optimal skin bridges.

In cases with a high degree of concern about infection, a staged procedure may be considered. However, in most cases, hardware removal can be done selectively at the time of THA surgery. Hardware that does not compromise placement of the THA may be left in place. Sometimes hardware can be cut off within the acetabulum to minimise exposure needs.

The reconstructive goal is to place the hip center as close as possible to normal hip center but also to gain good support of the socket on host bone. In most cases, both goals can be met. When necessary, some compromise in hip center of rotation may be considered to optimise implant stability on host bone. The principles of revision surgery are followed using uncemented acetabular components fixed with augmentation screws.

Most bone deficiencies may be managed with methods similar to revision hip surgery. However, in the acetabular fracture patient, usually the host femoral head is available and this can be used as bone graft, either in particulate or bulk form. Most cavitary deficiencies can be dealt with particulate bone graft. Some superolateral bone deficiencies from posterior wall fractures may be considered for bone grafting or augmentation techniques.

Nonunited fractures are not uncommon in these circumstances. Small wall nonunions may be managed as noted above for bone deficiency. If pelvic discontinuity is present, it is usually best treated by following the rules established for treatment of pelvic discontinuity with pelvic plating. Pelvic plating provides a reasonable likelihood of bone healing in these circumstances when combined with bone grafting techniques.

Heterotopic ossification is common in previously operated acetabular fractures. Removal of heterotopic bone at the time of surgery to gain hip motion is routine. Postoperative measures to reduce the likelihood of bone formation (that is either shielded radiation or use of a nonsteroid anti-inflammatory agent) may be strongly considered.

The sciatic nerve is at risk during these procedures. In many cases, avoiding the nerve and the region of the nerve is a reasonable approach. When a lot of work must be done on the posterior column, the surgeon needs to know exactly where the nerve is and in such cases the nerve may be exposed distally beneath the gluteus maximus tendon and followed proximally with careful and judicious dissection.

Results of total hip arthroplasty after acetabular fracture have varied in the past. More recent series have shown a high rate of acetabular fixation associated with uncemented hemispherical implants. Acetabular fracture patients are disproportionately young and active with unilateral hip disease and, therefore, bearing surfaces should be chosen accordingly.

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/blood management/preferred anesthetics, 2.) Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior, 3.) Acetabular fixation, 4.) Tips for optimising acetabular component orientation, 5.) Femoral fixation: (a) Indications for cemented and uncemented implants. (b) Role of hip resurfacing, 6.) Femoral head size, 7.) Bearing surface, 8.) Tips for optimising intraoperative hip stability, 9.) Tips for optimising leg length, 10.) Postoperative venous thromboembolism prophylaxis, 11.) Heterotopic bone prophylaxis, 12.) Postoperative pain management, 13.) Postoperative rehabilitation protocol: weight bearing, role of physical therapy, 14.) Postoperative activity restrictions, and 15.) Postoperative antibiotic prophylaxis for procedures.

Highly porous metal surfaces have transformed acetabular revision surgery by providing (1) enhanced friction which potentially provides greater primary fixation, (2) enhanced bone ingrowth potential, (3) enhanced screw fixation options. These characteristics have led many surgeons to use these devices routinely in acetabular revision and have led to an expansion of the indications for porous uncemented hemispherical cups in acetabular revision. Mid-term results suggest that the historical indications for hemispherical cups in revision surgery can be moderately expanded with some implants with these characteristics. In a recent study of 3448 revision total hip arthroplasties, we found porous tantalum cups had a statistically lower revision rate than other materials/designs. Highly porous metals also have provided the options of metal augments to fill selected bone defects—which can both enhance cup fixation and manage bone loss simultaneously. A number of different highly porous metals are now available, and how each will perform is not yet known.

Most early failures of THA are related to patient factors and technical “surgeon” factors. Most late failures of THA are related to patient factors and device factors. Occasionally unexpected device-specific failure modes cause specific early failure patterns. The most common reasons for early THA failure are infection and instability. Infection risk is strongly influenced by patient factors. Instability early after THA is usually a technical problem, but at times also is patient related. Important late failure modes of THA include loosening, wear and osteolysis, and periprosthetic fracture. Loosening and wear are at least in part device related. Late periprosthetic fracture is almost mainly patient related.

Taken together these data suggest the following:

Most strongly related to patient factors: Early and late infection, periprosthetic fracture and wear and osteolysis.

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/blood management/preferred anesthetics

Introduction

Total hip replacements using highly cross-linked polyethylene show excellent clinical outcomes, low wear, and minimal lysis at 5 years follow-up. A recent RSA study reports a significant increase in femoral head penetration between 5 and 7 years. This study is a multi-center radiographic analysis to determine whether the RSA observation is present in a large patient cohort.

Sir John Charnley unquestionably was the pioneer of modern joint arthroplasty. He was also an innovator in many other areas of orthopedics, including fracture care and arthrodesis, but this tribute will focus on his contributions to arthroplasty.

Charnley pioneered the use of methyl methacrylate cement and in so doing provided the first reliable means of fixing implants to bone. For the first time, this provided arthritis patients with reproducible long-term, reliable pain relief from advanced joint arthritis. Charnley also pioneered the use of a novel bearing surface, high molecular weight polyethylene. In so doing, he pioneered resurfacing of both sides of a joint with a low-friction, low-wear bearing. This provided the potential for excellent pain relief and also durable function of a hip arthroplasty.

Charnley understood the importance of reproducing joint mechanics and kinematics, and the arthroplasties he designed fully reproduced leg length and hip offset, and therefore the mechanics of the hip.

Finally, Charnley understood that technology is only a great value when it can be transferred effectively to many surgeons around the world. He created a carefully constructed educational structure to teaching the methodology in a way that would allow surgeons to practice this procedure successfully in other centers. Charnley understood the importance of minimizing complications for a procedure to be widely adopted and successful.

It is no exaggeration to state that Charnley’s contributions have helped tens of millions of patients worldwide who otherwise would have been permanently crippled by arthritis. Today’s further advances in joint arthroplasty are all dependent on the foundations of joint arthroplasty pioneered by Sir John Charnley.

Purpose of the study: Few data are available concerning the proper management of patients with a periprosthetic fracture of the hip who presents biological signs of inflammation (increased WBC, sedimentation rate, or C-reactive protein). The purpose of this work was to determine the prevalence of elevated biological markers in this type of patient and to determine the reliability of such markers for the diagnosis of periprosthetic infection.

Material and methods: A periprosthetic hip fracture was diagnosed in 204 patients from 2000 to 2006. The WBC count, the sedimentation rate and the serum CRP level were noted at admission to the emergency ward. The diagnosis of infection was confirmed by at least two positive bacteriological samples of tissue biopsy and/or joint fluid collected at surgery. A statistical analysis was conducted to determine the prevalence of elevated biological markers of inflammation, the sensitivity, their specificity and their positive predictive value for deep infection.

Results: Twenty-one patients (11.6%) developed a periprosthetic infection. Among the 204 patients, the WBC count increased in 16.2%, sedimentation rate in 33.3% and CRP in 50.5%. The sensitivity was 24% (WBC), 50% (sedimentation rate) and 83% (CRP). The specificity was 85% (WBC), 69% (sedimentation rate) and 56% (CRP). The positive predictive value was low (18, 21 and 29% respectively).

Discussion: Markers of inflammation are frequently ordered before surgery to search for infection but can be elevated for various reasons. Most often, these markers are elevated because of the patient’s general status and are thus related to other co-morbid conditions and/or reaction to the new fracture. In this population, the WBC count did not contribute to the diagnosis of infection as only 24% of the infected patients had a high count. CRP and sedimentation rate and the WBC count had low positive predictive values.

Conclusion: This study shows that an isolated elevation of biological markers of inflammation in a patient with a periprosthetic fracture is not a good indicator of infection.

Introduction: The International Knee Documentation Committee (IKDC) recommends use of the IKDC score to document subjective, objective and functional ACL outcome. To further improve knowledge concerning patient QOL after ACL reconstruction, an additional specific QOL questionnaire was developed. Using a combination of univariate and multivariate analysis the patient factors and surgical factors that influenced QOL 5- years after ACL reconstruction were determined.

Materials: 500 patients operated on for arthroscopic ACL reconstruction at our institution between 1997 and 2001 were prospectively enrolled. Patient psychosocial profile, sport expectations, knee exam, type of graft, associated lesion, type of anesthesia, complications, IKDC, KT 2000 at 6 moths, 1 year and 2 years were recorded. At five years, patients were asked to complete a 5-subscale validated QOL questionnaire for ACL deficiency. A multivariate analysis was performed to identify the factors influencing 5-year QOL.

Results: 203 patients completed the 5-years QOL questionnaire. Responders did not statistically differ from non responders. Patient subjective factors such as: patient expectations, pre-operative symptoms, work-school concerns, recreations concerns, social and psycho-social concerns were significantly (p< 0.05) and independently associated with the five-year QOL results. Objective factors such as meniscus tears and results of the KT 2000 (p< 0.05) were the two surgical factors correlated with 5-year QOL.

Discussion: In this large prospective study, most of the factors influencing the 5-year QOL results after ACL reconstruction were related to patient expectations, psycho-social, symptoms and work-sport concerns. The presence of a meniscus tear and greater KT 2000 laxity also contributed to poorer 5-year QOL results.

Studies of patients having primary THR using highly cross-linked polyethylene show excellent clinical outcomes and very low radiographic wear results at a minimum of 5 years follow-up. Recently, a radiostereometric analysis (RSA) study of a small group of patients reported that after no detectable wear during years 1–5, they found a significant increase in femoral head penetration between 5 and 7 years follow-up. However, this increase in head penetration after 5 years has not been confirmed in a larger patient cohort.

The purpose of this study was to organize a multicenter radiographic study involving leading medical centers in the U.S. having the longest-term follow-up available on this type of highly cross-linked polyethylene in order to determine if the RSA observation can be confirmed in a larger study.

Six academic centers agreed to contribute radiographic data to this study. All patients received primary total hip replacements with Longevity polyethylene liners (Zimmer, Warsaw, IN) coupled with 26, 28, and 32mm cobalt chrome femoral heads. The radiographic inclusion criteria required a minimum of four radiographs per patient: one at 1 year; at least one from 2 to 4.5 years; one 4.5 to 5.5 years; and at least one from 5.5 to 9 years follow-up. The Martell Hip Analysis Suit-eTM software was used for the wear analysis. All wear values were determined by calculating head penetration between the follow-up radiograph and the 1-year radiograph to remove creep, the majority of which has been shown to occur during the first year. Separate linear regressions, representing the wear rates, were computed for the early period from 1 year to 5.5 years and the late period from 5.5 years to 9 years follow-up. The Zar test was used to determine the significance of the difference between these two linear regressions.

We present the completed analysis of 165 hips. When the early and late data points were combined into one data set, the second-order regression indicated an inflection point at 6.3 years with a slightly positive inflection. There were 402 film comparisons in the early time period, and the slope and confidence interval of the regression line was 4.9μm/yr (95% CI of −28μm/yr to 38μm/yr). There were 188 film comparisons in the late period, and slope of the regression line for the late period was 10.8 μm/yr (95% CI of −58μm/yr to 80μm/yr). The Zar test showed no significant difference between the two slopes (Figure 1, p=0.886).

No significant increase in femoral head penetration was found for the late period after 5 years compared to the early period before 5 years follow-up in either analysis. Additionally, no significant late increase in wear was seen within individuals. While we continue to enroll patients, at this time we do not observe the increase in wear seen in the RSA study after 5 years.

Introduction and Aims: Hip arthroplasty alters stress patterns in the proximal femur, thereby influencing femoral bone remodelling. The purpose of our study was to determine long-term skeletal response to wellfixed total hip arthroplasty.

Method: Seventy-two hips in 66 patients (mean age 57, range 25–72; 29 male, 37 female) were evaluated with standardised measurement protocol after arthroplasty with cemented Charnley (32 hips) or uncemented 5/8 coated AML stem (40 hips). Inclusion criteria: stable implants and complete radiographic record with minimum follow-up 15–20 years. 3159 measurements were made with power calipers and normalised for magnification.

Results: There was time dependent loss of proximal cortical thickness around both stems (AML greater than Charnley; proximal medial greater than proximal lateral cortex, (p< 0.05, all parameters). At 15–20 years, median proximal medial cortical thickness decreased by 12% for Charnley and 70% for AML stems. Median proximal lateral cortical thickness decreased by 9% for Charnley and 21% for AML stems. Median cortical thickness changes around the mid and distal prosthesis for both stems was mild, with a non-statistically significant trend (p> 0.05) towards more cortical loss (2–9%) around Charnley than AML stems (0–8%). The median intramedullary width increased by 1–10%, depending on level (no difference by prosthesis type, p> 0.05). Changes continued progressively over the entire observation period.

Conclusion: This paper provides the first detailed long-term information on the effect of well-functioning hip arthroplasty on femoral morphology in a large patient group. Morphologic changes are most pronounced in the proximal medial femur and vary by implant type. Also, the medullary canal widens around a replaced hip as the patient ages.

The fixation concept of a fluted, conical, tapered grit-blasted titanium stem has been employed successfully in Europe, but the experience in North America with implants of this design is more limited. The most commonly studied stem of this design, the Wagner stem has been reported to provide good pain relief function and implant stability in several aeries, although large series with long-term follow-up are lacking.

Implants with a similar distal geometry but modular proximal features were introduced in an attempt to solve one of the practical difficulties of using a stem of this design: determining where the implant would seat was difficult, trialing options were limited, and accurate leg length and soft tissue balancing were difficult. Modular implants are more user-friendly but have the theoretical disadvantage of introducing the potential for modular junction failure (failure due to fatigue or fretting). To date, there are only limited (but favourable) short-term reported results on the efficacy of this form of revision.

Implants of this design can be used when rotational stability, axial stability, and long-term implant fixation must be gained primarily from the distal diaphysis of the femur. Examples include patients with periprosthetic femur fractures and patients with marked proximal bone thinning but good diaphyseal bone.

From the practical viewpoint, the fluted section of these implants must be straight (to allow milling of a cone-shaped diaphysis) and thus anterior cortical perforation is a potential complication. Anterior extended osteotomy as described by Wagner accomplishes the goal of femoral exposure and helps prevent distal anterior femoral perforation.

Uncemented hemispherical sockets are the implant of choice for most acetabular revisions. Several studies at mid-term document good clinical results, and furthermore, the implants are both versatile and technically straightforward to insert. When bone loss is present, the indications for uncemented sockets are expanded by using jumbo uncemented cups or uncemented cups placed at a high hip center. The main limitation of uncemented hemispherical cups is the need to place them on sufficient host bone to provide initial mechanical stability with a high, long-term likelihood of biologic fixation. The amount of host bone needed to meet these criteria has been debated. One rule of thumb that has been used is 50% surface area contact of the shell with host bone. However, for large sockets with a large surface area, a smaller percentage of the surface in contact with host bone may prove acceptable, provided the shell has host bone support in key areas including a peripheral rim fit and support in the dome of the socket.

When these criteria cannot be fulfilled, an alternative method of acetabular reconstruction must be considered. These alternatives include structural bone grafts, impaction grafting, and anti-protrusio cages. Anti-protrusio cages have the advantage of distributing forces over a large surface area of native bone, resisting migration, and being compatible with either bulk or particulate graft in massive acetabular deficiencies. These implants do not provide for biologic fixation and thus their use probably is best restricted to situations in which porous coated implants are not likely to work.

Pelvic discontinuity is a specific form of acetabular bone deficiency in which there is a transverse fracture of the acetabulum. Usually this occurs in association with marked acetabular bone loss and represents a stress fracture through deficient bone. Preoperative findings suggestive of pelvic discontinuity include: medial/lateral offset of the superior pelvis relative to the inferior hemipelvis, malrotation of the inferior hemipelvis relative to superior hemipelvis, or visible fracture line demonstrating the pelvic discontinuity. Judet films and true lateral radiographs of the hip can be helpful to delineate the presence of pelvic discontinuity.

The treatment principles for pelvic discontinuity include the following: 1.) gain stable fixation of the new acetabular implant. When the bone deficiency is relatively modest this may be possible with a hemispherical uncemented socket. Frequently, however, bone deficiency is massive and an anti-protrusio cage is necessary; 2.) restore pelvic continuity and stability. Usually this is possible with just a posterior column plate; 3.) bone graft large defects using particulate versus structural bone graft. In massive deficiencies structural bone grafts have the advantage of bridging the discontinuity and allowing healing of the native pelvis to the structural graft inferiorly and superiorly which may promote healing of the discontinuity.

The results of treatment of pelvic discontinuity are dependent on the severity of bone loss and whether or not the pelvis had previous therapeutic radiation; milder bone loss is associated with better results; and more severe bone loss and previous therapeutic pelvic radiation with worse results.

Surgery for pelvic discontinuity is complex and the most common complications include recurrent instability, infection, and sciatic neuropathy.

Prevention: Many periprosthetic femur fractures may be prevented by: (1) good patient follow-up, (2) timely reoperation of lytic lesions if radiographs suggest fracture risk, and (3) prophylactic use of longer stemmed implants or strut grafts to bypass cortical defects at revision surgery.

Treatment: Periprosthetic fractures can be treated using an algorithmic approach based on the Vancouver classification system. Fractures of greater or lesser trochanter (Type A)

Nonoperative treatment if displacement acceptable and if not associated with lysis

These fractures almost always require surgery. Nonoperative treatment is associated with high rate of malunion, nonunion, poor results. Treatment is according to fixation status of implant and bone quality.

Well-fixed stem (Type B1): ORIF with cable plate and/or strut grafts

* Principles: obtain fracture stability, implant stability, and optimise conditions for bone healing (use bone grafts, don’t strip periosteum)

Loose stem, unreconstructable proximal bone damage (Type B3): revise substituting for proximal femur with allograft prosthetic composite or tumour prosthesis

Ten cases are described of catastrophic failure of the polyethylene liner of three different designs of uncemented acetabular component. Failure occurred as a result of either 'wearthrough' to the metal backing, liner fracture or a combination of both, at a mean of 4.6 years after implantation (2 to 7.6). At revision there was metallosis in all hips and osteolysis of the femur or the pelvis in six. Catastrophic failure was seen only in cups with a minimum polyethylene thickness of less than 5 mm.

Revision hip arthroplasty in patients with massive acetabular bone deficiency has generally given poor long-term results. We report the use of an 'anti-protrusio cage', secured to the ischium and ilium, which bridges areas of acetabular bone loss, provides support for the acetabular socket, and allows pelvic bone grafting in an environment protected from excessive stress. Forty-two failed hip arthroplasties with massive acetabular bone loss were revised with the Burch-Schneider anti-protrusio cage and evaluated after two to 11 years (mean five years). There was failure due to sepsis in five hips (12%) and aseptic loosening in five (12%); the remaining 32 hips (76%) showed no evidence of acetabular component failure or loosening.