Introduction

Acetabular component positioning, offset, combined anteversion, leg length, and soft tissue envelope around the hip plays an important role in hip function and durability. In this paper we will focus on acetabular positioning of the cup.

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 to 150 microinches.

Introduction: Although volumetric wear reduction has been demonstrated in knee simulator studies, there is no long-term in-vivo evidence supporting wear reduction and durability with uni-directional rotating platform PS design. This design was introduced to reduced spin-out and provide greater range of motion. This is the first long-term report of this implant, a prospective study investigating clinical and radiographic survivorship with 10 years follow-up.

Material and Methods: Between January 2000 to March 2001, 118 consecutive patients (141 knees) received cemented RP TKRs. All patients were followed prospectively using clinical and radiographic criteria as defined by the Knee Society. At minimum nine years follow-up 20 patients were deceased, 11 were lost to follow-up and two refused to participate in the study, leaving 85 patients (100 knees) for final analysis.

Results: Good to excellent results were achieved in 95% of patients. There were no cases of malalignment, spinout, aseptic loosening or osteolysis. The mean ROM improved from 111.2 ± 15.2 degrees to 119 ± 3.8 degrees. The mean WOMAC score was 30 ± 14, KSS scores improved from an average of 48 to 96. Sporting activities such as golf, tennis and walking was 29%, 12% and 32%, respectively.

Anterior knee pain was present in 15% of cases. The incidence of asymptomatic crepitation and painful crepitation requiring scar excision was 10% and 4% respectively. During this period we had one case of infection and one revision for fracture. Kaplan-Meier survivorship at 10 years for mechanical failure and failure for all failures was 100% and 95.7%, respectively.

Discussion and Conclusion: Ten-year follow-up of RP-PS design demonstrates excellent clinical and radiographic results with no failures for mechanical reasons. There were no spin-out and average ROM was 119 ± 3.8 degrees.

Introduction: Acetabular component positioning, offset, combined anteversion, leg length, and soft tissue envelope around the hip plays an important role in hip function and durability. In this paper we will focus on acetabular positioning of the cup.

Technique: The axis of the pelvis is identified intra-operatively as a line drawn from the highest point of the iliac crest to the middle of the greater trochanter. Prior to reaming the acetabulum, an undersized trial acetabular component is placed parallel and inside the transverse ligament, inside the anterior column and projecting posterior to the axis of the pelvis. This direction is marked and the subsequent reaming and final component placement is performed in the same direction. The lateral opening is judged based on 45-degree angle from the tear drop to the lateral margin of the acetabulum on anteroposterior pelvic radiographs. The final anteversion of the cup is adjusted based on increase or decrease of lumbar lordosis and combined anteversion.

Methods: Anteroposterior pelvic radiographs of 100 consecutive patients undergoing posterior THR between September 2010 and March 2011 with this method were evaluated for cup inclination angle and anteversion using EBRA software.

Results: There were no malalignment or dislocation. The mean cup inclination angle and anteversion were 41 ± 5.1 degrees (range 37.1 – 48.4) and 22.1 ± 4.8 degrees (range 16.6 – 29.3), respectively.

Conclusion: This is a reproducible method of cup positioning and with proper femoral component position, restores leg length, offset, combined anteversion, and balances soft tissue around the hip. These factors affect the incidence of dislocation, infection, reduced wear, and durability.

Introduction: I always aim for neutral mechanical axis alignment. My principles of a successful TKA are proper alignment in all 3 planes, soft tissue balance in extension first, flexion gap balancing by parallel to tibial cut technique, maintenance of joint line, correct sizing of femoral component, and proper cement fixation.

Long-term Survivorship: There is long-term data that supports the efficacy and durability of the neutral position of the proximal tibial cut. Over a 20-year follow-up there was a 92.6% success rate in my study. Other authors have found similarly successful survivorship for mechanical failure.

Balance Technique in TKR: My technique to balance the knee is a balance extension gap first, which requires medial soft tissue balancing. Next, I balance the flexion gap parallel to the tibial cut.

Our Results: In one study, I examined the clinical and radiographic data of 68 varus knees. Average post-operative mechanical alignment was 0 ± 3 degrees. There were no outliers which displays the reproducibility of the technique. This is the method of choice in the hands of most surgeons.

Introduction

There has not been a comparison of patients and outcomes between two separate countries for any knee prosthesis. This study compares total knee replacement outcomes between an Indonesian and American cohort. We aim to compare the clinical results between two different hospitals in two different countries using post-operative range of motion as the primary clinical result.

Mastering the Art of Cemented Femoral Stem Fixation: Fixation of cemented femoral stems is reproducible and provides excellent early recovery of hip function in patients 60 to 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 to 150 microinches.

Cemented Primary Acetabulum: I am going to present a technique of cementing an all-poly socket. We have looked at our all-poly socket from 1992 to 1998 and the total number of hips are over 1,000, with a follow-up of 2 to 8 years. We have not revised a single socket for fixation failure.

The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximise range of motion, develop muscle strength, and provide emotional support. Over 85% of TKA patients will recover knee function regardless of which rehabilitation protocol is adopted but the process can be facilitated by proper pain control, physical therapy, and emotional support. The remaining 15% of patients will have difficulty obtaining proper knee function secondary to significant pain, limited preoperative motion, and/or the development of arthrofibrosis. This subset will require a special, individualised rehabilitation program, which may involve prolonged oral analgesia, continued physical therapy, more diagnostic studies and occasionally manipulation. Controlling pain is the mainstay of any treatment plan. The program described herein has been used at Ranawat Orthopaedics over the last 10 years in more than 2000 TKAs.

There exists a variety of options for a medial compartment knee with osteoarthritis, specifically a unicompartmental knee, high tibial osteotomy, and total knee arthroplasty. This surgeon prefers a rotating platform posterior stabilised total knee to the unicompartmental knee. Unicompartmental knee arthroplasty (UKA) in younger patients is being performed with increasing frequency. While UKA is a powerful marketing tool because of its minimally invasive nature and quality of knee function that is superior to the total knee arthroplasty (TKA), it has tremendous drawbacks. These include: the selection criteria is very specific and the number of patients that fit in that category is small, there is a steep learning curve for the surgeon to perfect the technique, higher failure due to wear and loss of fixation, and unexplained pain. Based on level 1 and 2 evidence available it is not justified to do more UKAs at present when the results of a TKA are so successful.

Introduction

Acetabular fixation is one of the major factors affecting long-term longevity and durability of total hip arthroplasty (THA). Limited data exist regarding mid-term performance of modern non-cemented rim-fit cups with HA coating. The aim of this study was to assess the minimum 5 year clinical and radiographic performance of PSL cups. Therefore we retrospectively analyzed results of this component in patients that had adequate followup from a prospective institutional database.

Background

Wear and osteolysis are major contributors, which limit the durability of total hip Arthroplasty (THA) and ultimately cause it to fail. Efforts were made to decrease wear by highly cross-linked polyethylene (HXLPE) and using ceramic bearings.

Background

Highly cross-linked polyethylene (HCLPE) was introduced to reduce wear and osteolysis in total hip arthroplasty (THA). There is no reported data regarding wear rates and clinical performance of Crossfire HCLPE (Stryker, Mahwah, New Jersey) in young and active patients. The purpose of this prospective study is to assess minimum 10-year wear rates and survivorship of Crossfire in young and active patients.

Introduction

Accurate and reproducible cup positioning is one the most important technical factors that affects outcomes of total hip arthroplasty (THA). Although Lewinnek's safe zone is the most accepted range for anteversion and abduction angles socket orientation, the effect of fixed lumbosacral spine on pelvic tilt and obliquity is not yet established.

Questions:

Introduction

Anterior knee pain (AKP) is a recognized cause of patient's dissatisfaction after total knee arthroplasty. Potential implant/technique related contributors to AKP are patellofemoral maltracking, trochlear geometry, femoral malrotation, patellar tilt and overstuffing. The primary aim of this prospective, matched pair study was to assess the safety, efficacy and performance of an anatomic patella and its effect on AKP in in a matched pair analysis.

A) Mastering the Art of Cemented Femoral Stem Fixation

The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximise range of motion, develop muscle strength, and provide emotional support. Over 85% of TKA patients will recover knee function regardless of which rehabilitation protocol is adopted but the process can be facilitated by proper pain control, physical therapy, and emotional support. The remaining 15% of patients will have difficulty obtaining proper knee function secondary to significant pain, limited preoperative motion, and/or the development of arthrofibrosis. This subset will require a special, individualised rehabilitation program, which may involve prolonged oral analgesia, continued physical therapy, more diagnostic studies and occasionally manipulation. Controlling pain is the mainstay of any treatment plan. The program described herein has been used at Ranawat Orthopaedics over the last 10 years in more than 2000 TKAs.

The bi-cruciate retaining (BCR) total knee arthroplasty (TKA) is based on sound biomechanics to produce kinematics close to normal, which is the goal of BCR TKA. This assumes that the joint line is maintained and both cruciates are functional with a range of motion greater than 125 degrees.

The technical difficulties of implanting such a knee in correct anatomical position with preservation of both cruciate ligaments with proper tension is challenging and may not be possible in the hands of most surgeons.

Patient selection for consideration of BCR TKA assumes that both ligaments are normal and ROM is greater than 125 degrees. If this assumption is correct, why does one need a knee replacement in such a patient? If we assume that the patient has normal cruciate ligaments, there is no scientific evidence to suggest that they will remain normal in the environment of a TKA with longer follow-up. Lastly, fixation with cement may be compromised because of the lack of a stem and less surface area. This can be argued both ways, but the long-term data on this matter favors stemmed designs. Moreover, insertion of cruciate ligaments (ACL) limits the robustness of the connecting bar for bicruciate knees. Lastly over 30 years, surgeons have tried BCR TKA without significant market share. Remember “all good things in life should ultimately prevail”.

Introduction

Cup positioning in total hip arthroplasty (THA) is an important variable for short and long term durability of any hip implant. This novel method utilises internal and external bony landmarks, and the transverse acetabular ligament for positioning the acetabular component.

Introduction

Proper balance and stability is essential to the longevity of total knee arthroplasty (TKA). The aim of this study was to evaluate long-term quality and performance of cemented total knee arthroplasty (TKA) in young and active patients using posterior stabilised designs.

Introduction

The common causes of failure leading to revision Total Knee Replacement (TKR) include instability, infection, improper alignment, implant wear and osteolysis and improper cementation. This presentation outlines the details of the art of cementation.

The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximise range-of-motion, develop muscle strength and provide emotional support.

Over 85% of TKR patients will recover knee function regardless of which rehabilitation protocol is adopted but the process can be facilitated by proper pain control, physical therapy and emotional support.

The remaining 15% of patients will have difficulty obtaining proper knee function secondary to significant pain, limited pre-operative motion and/or the development of arthrofibrosis. This subset will require a special, individualized rehabilitation program which may involve prolonged oral analgesia, continued physical therapy, more diagnostic studies and occasionally manipulation. Controlling pain is the mainstay of any treatment plan.

The program described herein has been used at Ranawat Orthopaedics over the last 10 years in more than 2000 TKRs.

Introduction

All current methods of cup placement use anterior pelvic plane (APP) as the reference. However, the majority of studies investigating the measurement of anteversion (AV) and abduction angles (AA) are inaccurate since the effect of pelvic tilt and obliquity are not considered. The aim of this study was to describe a reproducible, novel technique for functional cup positioning using internal and external bony landmarks and the transverse acetabular ligament (TAL).

Introduction

Ceramic femoral heads have proven to be more scratch resistant with better wettability and improved wear characteristics compared to metal heads in the laboratory setting. The objective of this study was to compare long-term survivorship and in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation in young patients.

Introduction

Studies have documented encouraging results with the use of fluted, tapered, modular, titanium stems in revision hip arthroplasty with bone loss. However, radiographic signs of osseointegration and patterns of reconstitution have not been previously categorized.

Introduction

It is not uncommon to encounter patients with atypical hip or lower extremity pain, ill-defined clinico-radiological features and concomitant hip and lumbar spine arthritis. It has been hypothesized that an anaesthetic hip arthrogram can help identify the source of pain in these cases. The purpose of this study is to analyze our experience with this technique in order to verify its accuracy.

Introduction: Computer-based wear analysis is currently the most accurate method for determining the in vivo wear rates of polyethylene liners during total hip arthroplasty. MRI of a total hip is emerging as the best method for determining the intra-articular volume of particulate debris. The purpose of this study is to determine if there is a correlation between polyethylene wear and the development of particle load in patients with highly crosslinked (HXLP) liners.

Materials and Methods: 20 well-functioning total hips (7 metal heads against HXLP liners and 13 ceramic heads against HXLP liners) in 18 young active individuals were analyzed using the following criteria: femoral head penetration of the liner was measured by Roman (ROntgen Monographic ANalysis) software and particulate load was calculated by MRI criteria as described by Potter et al. Clinical and radiographic analyses were performed using HSS, WOMAC, and criteria defined by DeLee, Charnley, and Engh. The average age of the patients was 57 (Range 45–67) and average follow-up was 1.6 y (range 1.0 – 3.0 y).

Results: All implants appeared well osteointegrated with no radiographic evidence of osteolysis. All patients had well-functioning total hips with a greater than one mile daily walking tolerance. A trend towards correlation was observed between increased polyethylene wear and increased particulate volumes. Average HXLP wear was 0.03 mm (range −0.19 to 0.27 mm) and average particle volume was 841 (range 6951 to 0). One patient in particular recorded 0.27 mm of polyethylene wear, mild particle disease and a particle disease volume of 3321 at 1.6 years follow-up. However, statistical significance could not be achieved with these data points.

Conclusions: There appears to be a relationship between polyethylene wear as measured by computer-based systems and particulate volume as measured by MRI. Limitations of the current methodology include the inability of computer-based systems to detect precise levels of minimal wear with HXLP liners, and the highly sensitive MRI images which may be detecting more than just wear debris.

The recent introduction of modern ceramic-on-ceramic total hip arthroplasties have demonstrated excellent clinical and radiographic results without catastrophic failure such as implant fracture associated with earlier designs. In laboratory wear testing, ceramicon-ceramic provides the least volumetric wear among all bearing surfaces. In recent years, with modern ceramic-on-ceramic bearing surfaces, clinical results with 5-to 7-year follow up have been good to excellent in 95–97% of cases. In spite of excellent results, certain limitations still exist including occasional fracture, stripe wear, squeaking, and neck-socket impingement producing metallic third body. Future improvement in ceramics (and other hard-bearing surfaces) and its coupling with other hard bearing surfaces appears to have significant advantages in reducing dislocation, impingement, stripe wear and squeaking.

The three distinct phases of design and development of total knee replacement (TKR) were:

1969–1985,

Hinge designs and early condylar designs highlight the first major period of TKR development from 1969 to 1985. These designs included but were not limited to the Waldius, Shiers, and GUEPAR hinges, Gunston’s Polycentric Knee in 1971, Freeman’s ICLH Knee in 1972, Coventry’s Geomedic Knee in 1972, St. George’s Sled Prosthesis in 1971, Marmor’s Modular Uni in 1971, Townley’s Condylar Design in 1972, Walker and Ranawat’s Duocondylar in 1971, Waugh’s UCI Knee in 1976, Eftekar’s Metal Backing in 1978, Murray and Shaw’s Metal Backed Variable Axis Knee in 1978, Insall and Burstein’s IB-1 Knee in 1978, the Kinematics in 1978, and finally Walker, Ranawat and Insall’s Total Condylar in 1978.

The Total Condylar Knee, developed by Walker, Ranawat, and Insall between 1974 and 1978, has been the benchmark for all designs through the 20th century. My personal experience of cemented TKR from 1974–2009 has shown a survivorship of 89%–98% at 15–20 years. Similar data has been presented in several 10+ year follow-up studies.

The next major phase of development gave birth to semi-constrained TKR, cruciate saving and substituting PS designs, improved instrumentation and improved cemented fixation. Other guiding principles involved improving alignment, managing soft-tissue balance for varus-valgus deformity, improving kinematics and producing superior polyethylene for reduced wear and oxidation. The advent of rotating platform mobile bearing knees with multiple sizes marked the most recent major advancement in TKR design.

With more total knee replacements being performed on younger, more active patients, improved design, better fixation (non-cemented), and more durable articulation are needed. The new standard for ROM will be 125 degrees. Non-cemented fixation, improved poly, such as E-poly, and the rotating platform design will play a major role in increasing the longevity of TKR to over 25 years.

The ability of optimised MRI to detect periarticular bony and soft tissue pathology in the post-arthroplasty hip is well documented; specifically it is able to detect early stages of particle disease well before osteolysis is apparent on radiographs. This is a prospective study designed to utilise MRI for the detection of early particle disease in asymptomatic patients after total hip arthroplasty.

Patients who underwent routine non-cemented THA were recruited from three different groups: metal-on-polyethylene, ceramic-on-ceramic, and ceramic-on-polyethylene bearing surfaces. All patients enrolled underwent optimised MRI one to three years (mean 1.7) after the index procedure. Images were analyzed for the presence of synovial proliferation, fibrous membrane formation or osteolysis. Particle disease was correlated with type of bearing surface, pain, activity level, patient satisfaction, and clinical outcome scales.

Thirty-two hips have been enrolled in the study to date. Early particle disease was seen in two of seven metal-on-polyethylene hips (29%), four of twelve ceramic-on-ceramic hips (33%), and six of thirteen ceramic-on-polyethylene hips (46%). Focal osteolysis was seen in one patient with a ceramic-on-polyethylene hip. These values were not statistically significant among the groups. The presence of early particle disease did not correlate with pain, activity level, patient satisfaction, or other clinical outcome scales.

This study allows patients with a well functioning total hip arthroplasty to be prospectively followed with MRI. It is the first to document the natural history of particle disease in vivo and considerably enhances our knowledge of periarticular pathology in the post-operative hip. These results demonstrate early particle disease is relatively common yet asymptomatic; they do not demonstrate advantages of any bearing couple over another for protection against particle disease at short-term follow-up.

We previously reported no clinical differences in short-term results in 26 patients that underwent fixed-bearing (FB) total knee arthroplasty in one knee followed by a rotating-platform (RP) version of the same implant in the contralateral knee at a later date. This study presents intermediate-term results in this unique cohort and uses optimised MRI for detection of particle disease in both knees.

Patients from the original series were asked to complete questionnaires regarding both knees. In addition, both knees were evaluated with optimised MRI, which has been shown to be useful in evaluating early particle disease and osteolysis before its appearance on radiographs.

Nine patients have been enrolled to date. At an average follow-up of 8.3 years for the FB side and 6.5 years for the RP side, no significant differences were found with respect to knee preference, pain, or overall satisfaction. Seven patients underwent MRI studies of both knees. Two FB knees demonstrated a massive intracapsular burden of particle disease (average 3066 mm3) with reactive synovitis, compared to no obvious particle disease in any RP knees. Osteolysis was seen around the femur in one FB knee and around the patella in two FB knees, compared to only around a single patella in the RP side.

RP knees continue to demonstrate excellent patient satisfaction that is comparable to clinical results of the FB design; however, FB knees demonstrate higher rates of particle disease and early osteolysis on MRI. This is the first study to demonstrate in vivo advantages of RP over FB designs. It is unclear whether this is due to the slightly longer follow-up period for the FB knees or a decreased wear rate in the RP design; these differences may become apparent with longitudinal follow-up.

Introduction: Although the problems of patello-femoral kinematics in contemporary total knee arthroplasty are multifactorial, meticulous surgical technique is pivotal in providing optimal and durable function. The goal of this study was to evaluate the incidence of lateral release comparing fixed and mobile bearing posterior stabilized modular press-fit condylar TKA’s with patellar resurfacing.

Materials and methods: Cohort 1 comprised 100 consecutive cemented Press-Fit Condylar Sigma, (Johnson & Johnson, Raynham, Massachusetts) modular total knee prostheses with a posterior cruciate substituting design and dome shaped single peg patellar component implanted prospectively by a single surgeon. Cohort 2 comprised 100 consecutive cemented Press-Fit Rotating Platform Sigma (Johnson & Johnson, Raynham, Massachusetts) modular total knee prostheses with the same posterior cruciate substituting design and patellar component.

The surgical technique comprised cutting the tibial surface perpendicular to the long axis, ligament balancing in extension followed by femoral component rotation referenced off the proximal tibial cut to produce a rectangular flexion gap. The patella was cut to the level of the lateral facet and tibial component rotation was referenced off the center of the ankle. Lateral release was performed if congruent patello-femoral contact was not attained in knee flexion. Clinical and radiographic review was performed as per Knee Society criteria. Additional radiographic evaluation included patellar displacement, tilt, residual bone thickness and coverage ratio. A patient-administered questionnaire was used to evaluate anterior knee pain and patello-femoral function 1 year after surgery.

Results: The incidence of lateral release in the fixed-bearing cohort was 10% 1 compared to 0% in the mobile bearing cohort (p< 0.05). There were no significant differences in terms of clinical or radiographic parameters at short term.

Discussion: This study demonstrates the benefit of self-correction of tibiofemoral rotational mismatch with mobile bearing TKA’s and improvement in patello-femoral tracking. Longer follow-up is necessary to confirm the effect on patello-femoral wear, fixation and durability.

Introduction: This prospective review provides an update on a cohort of 150 consecutive primary TKA’s with intermediate follow-up (mean 10 years) and provides insight into the benefits of the device and casts light on the effects of polyethylene wear in posterior stabilized modular designs.

Materials: Between February 1988 and February 1990, 150 consecutive cemented Press-Fit Condylar (PFC, Johnson & Johnson, Raynham, Massachusetts) modular total knee prostheses (118 patients) with a posterior cruciate substituting design were implanted prospectively by a single surgeon. Two independent observers employing a patient administered questionnaire and clinical and functional Knee Society scores assessed the clinical outcome. Radiographic review was performed per the Knee Society criteria. The cumulative survivorship analysis was performed in terms of best case and worst case.

Results: 20 patients (30 TKR) died and 14 patients (15 TKR −10%) were lost to follow-up. The mean duration of follow-up in this cohort of survivors was 10 years (range 8.5 – 12 years). The mean clinical and functional scores were 88 and 73 points respectively. Of the 105 TKR followed up, good to excellent results have been attained in 89.5%. 45 patients reported participation in recreational sports. The overall projected clinical and radiographic survival was 93.6% at 12 years (CI +5.9%). Revision TKA was performed in 5 knees – 2 infection, 1 instability and 2 polyethylene wear, synovitis and osteolysis. There were no cases of aseptic loosening in the absence of polyethylene wear.

Discussion: Although the 12-year survivorship results of the cemented, posterior cruciate substituting press-fit condylar modular total knee prosthesis have been successful in terms of quality of fixation, the phenomenon of ‘back-side’ polyethylene wear at the modular tibial base-plate and resultant osteolysis offset the benefits of the modularity with longer follow-up. Attention needs to be focused on the improvement of the locking mechanism or alternatives with improved newer wear-resistant polyethylene, one-piece tibial components or newer implant designs with mobile bearings such as rotating platforms with posterior substituting design.

Introduction: The objectives of this study were to evaluate acetabular bone deficiency in revision THA with a simple classification on the anteroposterior pelvis radiograph and correlate the results of cementless hemispherical porous coated cup and cancellous bone graft reconstruction.

Methods: 70 acetabular revisions reconstructed employing large ‘jumbo’ porous coated cups with cancellous allo-grafting were evaluated at a mean follow-up of 5 years (range 2 – 10 years). During this time period 7 additional acetabular reconstructions required impaction grafting, cage reinforcement and cemented cups. Pre- and postoperative measurements of acetabular bone loss and the position of the revision component were performed with respect to a previously described triangle defining the placement and size of an idealcup. Impaction bone allo-grafting techniques were employed to fill defects. A minimum of 40% implant contact to host bone, especially in the weight-bearing dome region was attained in all cases and a minimum of 2 screws supplemented fixation to the ilium. Clinical evaluation comprised the HSS score and a patient assessment questionnaire (PAQ). Radiographically, cups were examined for filling of defects, ingrowth, graft consolidation, and stability.

Results: The mean HSS score improved from 18 to 33 out of a maximum of 40. The mean superior bone defect was 18 mm (range 10 – 25mm) and the mean medial bone defect was 7 mm (range 0 – 22mm). All the cement-less acetabular components were bone ingrown with the exception of one stable fibrous union. Allograft incorporation occurred at a mean of 7 months after surgery. Neither the status of Kohler’s line nor the Paprosky class correlated with eventual radiographic or clinical results.

Discussion: We present a simple method of evaluation of acetabular bone deficiency on the A-P pelvis radiograph employing a triangle that locates the ideal center of rotation of the hip. Superior bone loss upto 25 mm and medial migration as much as 22 mm has been successfully reconstructed employing impacted, cancellous allograft, large porous coated hemispherical Cementless acetabular components and screw fixation with excellent outcomes at intermediate-follow-up. Larger defects necessitate complex reinforced cage reconstruction.

Bankston et. al. reported that the clinical wear rates of molded acetabular cups was 50% less than a group of machined UHMWPE cups. However, due to covariables between groups including different femoral stems, cement technique, polyethylene resins and surgeons, unequivocal attribution of the low wear rates to direct molding could not be made.

In order to more directly assess the benefits of directly molded acetabular cups vs. machined cups, we report the comparison of hip simulation wear rates of machined and directly molded cups. These simulator results will then compared to two recent clinical reports on molded and machined cups of the same hip stem and cup design. The molded cups were made from 1900 resin and gamma sterilized in an inert atmosphere. The machined cups were made from HSS reference UHMWPE (4150) and gamma sterilized in air. The molded 1900 cups had a 55% lower wear rate after 5 million cycles on the hip simulator (14 v. 31mg/million cycles). Ranawat reported the average linear head penetration rate for 235 direct-lymolded, all polyethylene, cemented cups at a mean follow-up time of 6 years was .075mm/year. This is 56% lower than the rate of .17 mm/year he reported previously for the machined, uncemented metal-backed cups of the same design. These results provide further evidence that directly molding acetabular cups can provide wear rates over 50% less than machined cups both in both clinical and hip simulator evaluations. It is interesting to note based on other reports, that there is no osteolysis at 10 years of follow-up when the wear rates are < 1mm. The clinical and simulation wear rates reported here for the directly molded cups are within this performance range.

Introduction: Polyethylene wear debris is the main contributing factor that leads to aseptic loosening and osteolysis. The main objective of this study was to evaluate the role of hydroxyapatite (HA) in third-body polyethylene wear in total hip arthroplasty.

Materials: 199 primary cementless THA’s (174 patients) performed by a single surgeon were enrolled in a prospective randomized study comprising Hydroxyapatite and non-hydroxyapatite coated femoral implants. The femoral component had metaphyseal-diaphyseal fit design with proximal plasma sprayed titanium circumferential porous coating. The hydroxyapatite coating was 50 – 75 micrometers over the porous surface with the components of identical design. The acetabular component was plasma sprayed titanium porous coated shell without hydroxyapatite

Introduction: This purpose of this prospective review is to evaluate the 12-year results of a previously unreported collarless, cemented, normalized, straight-backed Omnifit femoral stem with a surface roughness of 30–40 microinches.

Methods: Between January 1986 and June 1991, a single surgeon prospectively implanted 305 consecutive cemented THA’s (275 patients) utilizing second-generation cement technique and a posterolateral exposure. The acetabular component was cemented all-polyethylene (4150 resin), with calcium stearate and gamma sterilized in air. Two independent observers employing a patient administered questionnaire, HSS scores and established radiographic criteria performed clinical and radiographic evaluation. The cumulative survivorship analysis was analyzed in terms of best case and worst case.

Results: The demographics included a mean age of 70 years with 170 females and 105 males and a mean body weight of 154 lbs. The preoperative diagnosis was osteoarthrosis in 260 hips, rheumatoid arthritis in 20, fracture in 13, AVN in 8, Paget’s in 2 and hip dysplasia in 2. The mean HSS score was 37.5 out of 40 at last follow-up. The mean clinical follow-up was 12 years and mean radiographic follow-up was 10 years. The overall projected clinical survival was 95.1% at 15 years (CI +3.4%). The cement mantle was grades A or B in 90% and grade C1 in 10%. Femoral stem alignment was neutral in 53%, valgus in 31% and varus in 16%. Revision THA was performed in 9 hips. Both components were revised in 3 cases (2 infection, 1 recurrent dislocation). Socket revision was performed in 4 cases (1.31%) and femoral component revision in 2 cases (0.65%) due to aseptic loosening.

Discussion: This report demonstrates the excellent results of the collarless, cemented, normalized femoral stem with a surface roughness of 30–40 microinches. Although controversy exists on surface roughness and porosity reduction, meticulous technique in the attainment of a centralized femoral stem with a good cement mantle, provides a reproducible, high quality of function and durability of THA in patients 60 – 80 years of age at 12-year follow-up.

Introduction: Mid-term follow-up has demonstrated good implant longevity for titanium fiber mesh and sintered bead designs, but few reports exist demonstrating the results of titanium plasma spray coated acetabular components in primary THR.

Methods: Between 1992 and 1995, a single surgeon performed 305 non-cemented primary THA’s in 260 patients. The selection criteria for non-cemented fixation were age younger than 65 and/or good bone quality. The hemispherical titanium plasma sprayed acetabular components were implanted with under reaming of 2 mm. Solid shells were used if a snug fit was attained with the trial. Screws were used to supplement fixation based on the surgeon’s judgment. The polyethylene liners were machined molded from ram extruded Hi-fax 1900H polyethylene resin gamma-sterilized in air or argon (inert) gas with elevated walls and locked into the shell via a Ring-Loc mechanism. These were mated with a 28mm cobalt-chrome femoral head and modular femoral component of metaphyseal-diaphyseal fit design with proximal titanium plasma spray porous coating. 15 patients have died, and 35 patients were lost to follow-up, leaving 225 hips in 210 patients that constitute the study cohort. The mean age was 55 years (range 24 – 60 years), and average.

Results: From this cohorts of patients, seven hips have been revised, two for infection, one for instability and four for osteolysis. The remaining patients had an average HSS score of 38 out of 40 at recent follow-up. Radiographically, the average cup inclination was 38.8 degrees. Eight hips had one zone interface lucencies, while three had two zone lucencies. There were no cases of continuous interface radiolucency or failure to achieve bone ingrowth. Nine hips demonstrated osteolysis, mostly in zones 2. The acetabular components in the cases with osteolysis were shells with unfilled screw holes in 3 and shells fixed with screws in 6. No osteolysis was detected in cases with solid hemispherical acetabular shells.

Discussion: Hemispherical titanium plasma sprayed ace-tabular components have achieved excellent durability at medium term follow-up, with a low incidence of fixation failure or osteolysis, and a low re-operation rate, even in a young, active group of patients. However, shells with screw holes appear to predispose to osteolytic lesions.

Introduction: Polyethylene wear debris is the main contributing factor that leads to aseptic loosening and osteolysis. The main objective of this study was to evaluate the role of hydroxyapatite (HA) in third-body polyethylene wear in total hip arthroplasty.

Materials: 199 primary cementless THA’s (174 patients) performed by a single surgeon were enrolled in a prospective randomized study comprising hydroxyapatite and non-hydroxyapatite coated femoral implants. The femoral component had metaphyseal-diaphyseal fit design with proximal plasma sprayed titanium circumferential porous coating. The hydroxyapatite coating was 50 – 75 micrometers over the porous surface with the components of identical design. The acetabular component was plasma sprayed titanium porous coated shell without hydroxyapatite. T he polyethylene liners were machined molded from ram extruded Hi-fax 1900H polyethylene resin gamma-sterilized in argon (inert) gas. Clinical and Radiographic evaluation was performed employing HSS scores and Engh criteria.

Results: At a mean follow-up of 5 years, the radiographs of 83 HA and 73 Non-HA hips were evaluated by two independent observers utilizing computer-assisted wear analysis on digitized standardized radiographs described by Martell et al (1997). The radiographs were also evaluated for osteolysis or aseptic loosening.

The mean linear wear rate in HA group was 0.19mm/yr and in the non-HA group was 0.21mm/yr, which was not significant (p> 0.05). There was no case of osteolysis or aseptic loosening of any component. Both groups had comparable outcomes in terms of HSS scores, walking ability and sports participation.

Discussion: This study has attempted to demonstrate through an appropriately controlled in vivo study that hydroxyapatite does not play a significant role in third-body polyethylene wear in THA at a mean follow-up of five years. The concern of three-body wear with hydroxyapatite coating is no greater than porous coated cementless implants.

Cemented stem fixation is a proven technique in total hip arthroplasty (THA), however, aseptic loosening is a noted complication. Cementless fixation is also popular in THA, however thigh pain and osteolysis are known problems with short-term and long-term follow- up, respectively. In order to improve the initial development and durability of the osseointegration of porous coated cementless implants, hydroxyapatite (HA) has been claimed to provide a biological adjuvant for femoral stem fixation in THA.

There is no prospective, randomised long-term study comparing clinical radiographic findings between proximally HA-coated and non-HA coated surfaces of an identical stem design. We investigated 177 patients (199 hips) who received either HA-coated or non-HA coated stems. Clinical information from 163 patients (181 hips), including walking ability, thigh pain, sports activity, and overall patient satisfaction was collected. Evidence of radiolucencies, stem migration, and canal fill was measured on AP and lateral radiographs. In addition, tension trabeculae on the lateral aspect of the proximal stem and stress-induced remodelling of cancellous bone against porous surface (SIRCAP) were noted as signs of bone ingrowth.

Both groups of patients performed well on the basis of HSS scores, walking ability, sports activity, and overall patient satisfaction. However the non-HA group demonstrated a significant increase (p< 0.05) in activity- related thigh pain. There were no significant radiographic differences between patient cohorts with all stems demonstrating bone ingrowth. In our prospective, randomised study, we conclude that the use of HAcoated stems results in increased clinical satisfaction to the THA patient.

Leg length inequality, both actual and functional, is the most important cause of disappointment for the surgeon and his patient.

The reported incidence of leg length inequality of 1 cm has been reported to be between 23% and 50%, and half of these patients require a lift in their shoe. In the author’s opinion, there is a relationship between leg length and stability of the hip. Increase in leg length and offset improves soft tissue tension and reduces the dislocation rate.

The goal at surgery is:

To restore the center of rotation for the hip

The various tests for hip stability, soft tissue tension and contractures:

Assess component position

Leg length inequality is caused by:

Increase in anatomic leg length or offset or both

We used survival analysis to evaluate 113 consecutive semiconstrained total elbow arthroplasties (TEAs) in 95 patients at a maximum follow-up of 99 months. Our criteria for failure were mechanical malfunction, revision for any reason, and deep infection. The primary diagnosis was inflammatory arthritis in 86 elbows, post-traumatic arthritis in 6, supracondylar nonunion or fracture in 12, osteoarthritis in 2 and other causes in 3. Seven failures were due to deep infection, and five of these had a primary diagnosis of inflammatory arthritis. Eight failures were revised or had revision recommended for aseptic loosening, and six of these were in patients with post-traumatic arthritis or supracondylar nonunion. The cumulative survival for TEAs performed for post-traumatic arthritis, fractures or supracondylar nonunion was 73% at three years and 53% at five years, significantly worse than the cumulative three- and five-year survivals of 92% and 90%, respectively, for patients with inflammatory arthritis. TEA with a semiconstrained prosthesis appears to have a satisfactory survival in selected patients with arthritic disorders. The incidence of deep infection was reduced by improvements in surgical technique and postoperative management, and the routine use of antibiotic-impregnated cement. The incidence of aseptic loosening was low, except in patients with supracondylar nonunion or post-traumatic arthritis.

We reviewed 19 revision hip arthroplasties in which the new femoral component had been recemented into the old, intact cement mantle. The mean time from the first operation to revision was 64 months and the average follow-up was 59 months. There were 7 excellent, 11 good, and one fair result. No femoral component had been revised for loosening and all the stems appeared radiographically stable. Complications included intraoperative perforation of the femur on two occasions and one dislocation. The use of the cement-within-cement technique requires that the old cement surface be dry and roughened to increase the surface area and that the cement be injected in the liquid phase to prevent lamination. The indications for this technique include a broken stem with an intact distal cement mantle, the removal of a femoral component for revision of a loose cup to improve exposure and/or increase offset, recurrent dislocation secondary to component malposition, and debonding of the femoral component within an intact cement mantle.

We selected 20 matched pairs of patients who had had total hip arthroplasty by the same surgeon using the same cemented technique. Matching was by age, sex, height, weight and diagnosis. One of each pair had received hypotensive epidural anaesthesia, with less than 300 ml blood loss: the other had normotensive general anaesthesia with more than 500 ml of blood loss. Early postoperative radiographs were evaluated independently by three blinded observers, using a scoring criteria which assessed the quality of the cement-bone interface. The results showed that patients who had received epidural anaesthesia had significantly better radiographic scores (p less than 0.02). Our findings suggest that hypotensive anaesthesia facilitates penetration of cement into bone.