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Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 62 - 62
1 Oct 2019
White PB Satalich J Ranawat AS Ranawat CS
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Background

The purpose of this study was to evaluate the clinical and radiographic outcomes of the rotating-platform, posterior-stabilized PFC Sigma at fifteen-year follow-up.

Methods

Between January 2000 and November 2001, two hundred consecutive patients underwent TKA with a rotating-platform, posterior stabilized total knee arthroplasty with cement. All patients have been followed prospectively and all patients with minimum 12 year follow up were included in this analysis. Forty-nine TKAs were available for our final analysis with a mean follow up of 16.0 years.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 37 - 37
1 Oct 2018
James EW Blevins J Gausden E Turcan S Satalich J Denova T Ranawat AS Ranawat AS Ranawat CS Warren RF
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Introduction

Anterior cruciate ligament (ACL) and multiligament knee (MLK) injuries increase the risk of development of knee osteoarthritis and eventual need for total knee arthroplasty (TKA). There is limited data regarding implant use and outcomes in these patients. The aim of this study was to compare the use of constrained implants and outcomes among patients undergoing TKA with a history of prior knee ligament reconstruction (PKLR) to a matched cohort of patients undergoing TKA with no history of PKLR.

Methods

All patients with history of ACL or MLK reconstruction who underwent TKA between 2007–2018 were identified in a single institution registry. A matched cohort was identified based on patient age, body mass index (BMI), sex, and year of surgery. The primary outcome measure was utilization of constrained implants. Secondary outcomes included rates of deep vein thrombosis (DVT), pulmonary embolism (PE), infection, postoperative transfusion, postoperative knee range of motion (ROM), revision surgery, and patient reported outcomes (Knee Injury and Osteoarthritis Outcome Score for joint replacement (KOOS, JR).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 116 - 116
1 Jan 2016
Park C Meftah M Ranawat CS
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Introduction

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 the wear by highly cross-linked polyethylene (HXLPE) and using ceramic bearings. The purpose of this study is to analyze the five year performance of large sized (32mm and 36mm) ceramic and metal heads on X3 HXLPE (Stryker, Mahwah, NJ).

Materials and Method

From Jan 2006 to June 2008, 81 consecutive patients with minimum 5 year radiographic and clinical followup were identified from out institutional prospective database. 51 non-cemented THA (45 patients) had ceramic on HXLPE (CoX3) group and 30 hips (29 patients) had metal on HXLPE (MoX3) group. Mean age was 36 ± 8 years (36–76) and 50 ± 9 years (51–86) in ceramic and metal group, respectively. Wear rates were measured on an anteroposterior weight-bearing pelvis radiographs using the computer-assisted Roman software.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 130 - 130
1 Jan 2016
Park C Ranawat CS Ranawat AS
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Introduction

Potential implant and technique related factors to improve patellofemoral (PF) kinematics in total knee arthroplasty (TKA) are design of trochlear geometry and patella, restoration of posterior offset, patellar tilt and avoid overstuffing. The primary aim of this prospective, matched pair study was to assess the radiographic features of PF kinematics with an anatomic patella.

Material and Methods

Between July 2012 and May 2013, 49 consecutive posterior stabilized cemented Attune TKAs (Depuy Synthes Warsaw Indiana) were matched to the 49 PFC Sigma (Depuy) based on age, gender, and body mass index (BMI). All surgeries were performed via medial parapatellar approach with patellar resurfacing. Radiographic analysis was performed prospectively with minimum 1-year follow-up and included overall limb alignment, anterior offset, posterior offset, joint line, patellar thickness, patellar tilt and patellar displacement by two independent observers.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 129 - 129
1 Jan 2016
Park C John T Ghosh G Ranawat AS Ranawat CS
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Introduction

Total hip arthroplasty (THR) with non-cemented or hybrid fixation remains one of the most successful procedures performed today. The aim of this study was to assess the safety and efficacy of a hydroxyapatite (HA) coated, hemispherical cup.

Material and Methods

Between 2003 and 2007, 223 THAs (210 patients) with peripheral self-locking (PSL) cup and highly cross-linked polyethylene (Crossfire, Stryker, Mahwah, NJ) with minimum 5 years clinical and radiographic follow-up (5–9 years) were analyzed. The mean age was 62.5 years ± 10.8 (range, 32.7 – 86.3) at the time of surgery and the predominant preoperative diagnoses was osteoarthritis (97.8%). 72% were solid cups without screw augmentation and 28% were multi-hole with screw. Clinical analysis included Hospital for Special Surgery (HSS) hip scores at latest follow-up. Detail radiographic analysis was carried out on anteroposterior and false profile views for evidence of osseointegration in all Charnley's zones. Osseointegration was assessed based on presence of Stress Induced Reactive Cancellous Bone (SIRCaB) with trabecular bone hypertrophy 5–15mm extending from the cup, and absence of radiolucency or demarcation. EBRA software was used to assess cup positioning.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 492 - 492
1 Dec 2013
Meftah M Ranawat A Ranawat CS
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Introduction:

Non-cemented, porous-coated metaphyseal sleeves have been designed to improve biologic fixation and stability in revision total knee arthroplasty (TKA) with major bone defects. The aim of this study was to evaluate the clinical results and osteointegration of these sleeves in major bone loss.

Materials and Methods:

Between 2008 and 2011, 24 revision TKAs with major bone loss were reconstructed with non-cemented, porous-coated proximal sleeve (DePuy, Warsaw, IN). All patients were prospectively followed for a minimum of 2 years. Indications for use of sleeves were major metaphyseal tibial and femoral bone loss, younger age, and higher activity level. Osteointegration around the sleeves were classified as:

Grade 1: Complete osteointegration in all views without any demarcation.

Grade 2: Sleeves that are not completely osteointegrated but they are stable.

Grade 2A: Demarcation less than 2 mm on any view

Grade 2B: Demarcation more than 2 mm on any view

Grade 3: Sleeves that are not osteointegrated and unstable with evidence of subsidence.

Grade 3A: Subsidence less than 2 mm on any view

Grade 3B: Subsidence more than 2 mm on any view


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 125 - 125
1 Dec 2013
Meftah M Potter H Ranawat A Ranawat CS
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Introduction:

The earliest evidence of particle-induced response is found in the synovium, leading to osteolytic defect. The degree of synovitis can be quantified by magnetic resonance imaging (MRI). This is the first long-term, prospective, matched-pair study using MRI to analyze wear-induced synovitis and osteolysis between rotating-platform posterior-stabilized (RP-PS), fixed-bearing metal-back (FB-MB), and all-polyethylene tibial (APT) designs in active patients with identical femoral components and polyethylene.

Methods:

From September 1999 to October 2001, a matched-pair analysis of 24 TKAs (18 patients, 3 groups: 8 RP-PS, 8 FB-MB, and 8 APT) was performed. TKAs were matched for age, sex, body mass index (BMI), and University of California Los Angeles (UCLA) activity scores. All patients underwent MRI using MAVRIC (multi-acquisition variable-resonance image combination) knee protocol designed to reduce metal susceptibility artifact. Images were evaluated for volumetric measure of synovitis and/or osteolysis and presence of fibrous membrane formation at the cement-bone interface.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 285 - 285
1 Dec 2013
Deshmukh A Rodriguez J Cornell C Rasquinha V Ranawat A Ranawat CS
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Introduction:

Severe bone loss creates a challenge for fixation in femoral revision. The goal of the study was to assess reproducibility of fixation and clinical outcomes of femoral revision with bone loss using a modular, fluted, tapered distally fixing stem.

Methods:

92 consecutive patients (96 hips) underwent hip revision surgery using the same design of a modular, fluted, tapered titanium stem between 1998 and 2005. Fourteen patients with 16 hips died before a 2-year follow-up. Eighty hips were followed for an average of 11.3 years (range of 8 to 13.5 years). Bone loss was classified as per Paprosky's classification, osseointegration assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Serial radiographs were reviewed by an independent observer to assess subsidence, osseointegration and bony reconstitution.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 493 - 493
1 Dec 2013
Meftah M Ranawat A Ranawat CS
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Introduction:

Hard-on-hard bearings and surface replacement (SR) have been used in young and active patients due to the reduced wear and lower rates of osteolysis. However, neither of these options resulted in survivorship higher than 90%–95% in this group of patients. The purpose of this prospective study was to compare minimum 10-year survivorship of non-cemented total hip arthroplasty (THA) using 28 mm metal head against highly-cross linked polyethylene (HXLPE) in our cohort as compared to published reports of other bearings, including surface replacements, in young-active patients.

Matierial and Methods:

From 1999 to 2003, 91 consecutive patients (112 hips; 57 males and 34 females) with average UCLA score of 8 and mean age 53 years (range 24–65 years), who received metal on HXLP (Crossfire), were included. At minimum 10-years follow-up, patients' clinical data was assessed. All level I, II studies, registry data, and prospective cohorts published in the literature with minimum 10 years of surface replacement (SR) and ceramic on ceramic (CoC) in young patients were included.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 126 - 126
1 Dec 2013
Meftah M Ranawat A Ranawat CS
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Introduction:

Proper component orientation and soft tissue balancing are essential for longevity of total knee arthroplasty (TKA), especially in young and active patients. The aim of this study was to evaluate long-term results and quality of TKA in young and active patients with extension first gap balancing technique, in 2 Posterior-Stabilized (PS) total knee designs with identical femoral component.

Material and Methods:

43 consecutive Rotating-Platform (RP-PS, 33 patients) and 38 Fixed-Bearing (FB-PS, 29 patients) with University of California Los Angeles (UCLA) activity score of 5 or above and mean age was 53 ± 1.5 years were followed prospectively for a minimum of 10 years. 18 random TKAs were analyzed for component rotation using MRI.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 357 - 357
1 Dec 2013
John T Shah G Lendhey M Ranawat A Ranawat CS
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Introduction

Total hip arthroplasty (THR) is one of the most successful procedures performed today. Uncemented acetabular components have by and large replaced cemented cups. As such, optimal fixation, bony ingrowth with longevity, and safety is highly demanded. In this study, we look at the safety and efficacy of the Stryker® Trident PSL™ acetabular component based on radiographic and clinical analysis.

Materials and Methods

We looked at 860 consecutive patients between 2003 and 2007. Of these, 231 consecutive patients had a minimum 5 year follow up. All cases were for degenerative joint disease (DJD), except 2 for dysplasia, 1 for avascular necrosis (AVN), 1 femoral neck nonunion. Average Hospital for Special Surgery (HSS) hip scores at final follow up were recorded. Radiographic analysis included classification based on Delee and Charnley's zones 1–3. Osseointegration was assessed based on presence of SIRCAB (stress induced reactive cortical hypertrophy of bone), demarcation around the implant, stress shielding, presence of radial trabeculae, absence of radiolucency, type of bearing, presence of preoperative protrusion, violation of Kohler's line. EBRA software was used to assess acetabular inclination and version.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 527 - 527
1 Dec 2013
Sculco P Lipman J Klinger C Lazaro LE Mclawhorn A Mayman DJ Ranawat CS
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Introduction:

Successful total joint arthroplasty requires accruate and reproducible acetabular component position. Acetabular component malposition has been associated with complications inlcuding dislocation, implant loosening, and increased wear. Recent literature had demonstrated that high-volume fellowship trained arthroplasty surgeons are in the “safe zone” for cup inclination and anteversion only 47% of the time. (1) Computer navigation has improved accuracy and reproducibility but remains expensive and cumbersome to many hospital and physicians. Patient specific instrumentation (PSI) has been shown to be effective and efficient in total knee replacements. The purpose of this study was to determine in a cadaveric model the anteversion and inclination accuracy of acetabular guides compared to a pre-operitive plan.

Methods:

8 fresh-frozen cadaveric pelvis specimens underwent Computer Tomography (CT) in order to create a 3D reconstruction of the acetabulum. Based on these 3D reconstruction, a pre-operative plan was made positioning the patient specific acetabulum guides at 40 degrees of inclination and 20 degrees of anteversion in the pelvis.(Figure 1) The guides were created based on the specific bony morphology of the acetabular notch and rim. The guides were created using a 3D printer which allowed for precise recreation of the virtual model. 7 cadaveric specimens underwent creation and implantation of a acetabular guide specific to each specimens bony morphology. Ligamentum, pulvinar, and labum were removed for each cadaver prior to implantation to prevent soft tissue obstruction. The guides were inserted into the acetabular notch with the final position based on the fit of the guide in the notch. (Figure 2) Post-implantation CT was then performed and inclination and anteversion of the implanted guide measured and compared to the preoperative plan.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 491 - 491
1 Dec 2013
Meftah M Ranawat A Ranawat CS
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Introduction:

Jumbo cups (58 mm or larger diameter in females and 62 mm or larger diameter in males), theoretically have lowered the percentage of bleeding bone that is required for osseointegration in severe acetabular defects. The purpose of this study was to analyze the safety and efficacy of Tritanium jumbo cups in patients with major acetabular defects (Paprosky type IIIa and IIIb) and assess the extent of osseointegration.

Material and Methods:

From February 2007 and August 2010, 28 consecutive hips (26 patients, mean age of 69 years) underwent acetabular revision arthroplasty for treatment of Paprosky type IIIa and IIIb defects using Tritanium jumbo cups (Stryker, Mahwah, New Jersey).


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 307 - 307
1 Mar 2013
Ranawat A Meftah M Thomas A Lendhey M Ranawat CS
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Introduction

The goal of revision total hip arthroplasty (THA) for acetabular defects is to achieve the best stability and fixation with available host bone. Tritanium is a highly porous metal construct with a titanium matrix coating. We are reporting our experience of utilizing this material in patients with major acetabular defects.

Methods

Between February 2007 and August 2010, 24 consecutive hips (23 patients) underwent acetabular reconstruction using the Tritanium cups. The acetabular defects were assessed using the Paprosky classification. Anteroposterior and lateral radiographs were analyzed at follow-up based for the presence of radiolucent lines more than 2 mm in any of the 3 zones.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 306 - 306
1 Mar 2013
Ranawat A Meftah M Klingenstein G Yun RJ Ranawat CS
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Introduction

Ceramic femoral heads have superior 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 in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation with cementless stems in young, active patients.

Materials and Methods

Thirty-one matched pair of alumina and metal (Cr-Co) femoral heads against conventional polyethylene in young patients (between 45 and 65 years old) were analyzed for wear and failures for mechanical reasons. The match was based on gender and age at the time of surgery. All procedures were performed between June 1989 and May 1992 by a single surgeon via posterolateral approach, using cementless RB (Ranawat-Bernstein) stems, HG II (Harris-Galante) cups, 4150 conventional polyethylene and 28 mm femoral heads. Hospital for Special Surgery (HSS) hip score was used for clinical analysis. Wear measurements were performed between the initial anteroposterior standing pelvis radiographs, at a minimum of one year after the index procedure to eliminate the effect of bedding-in period, and the latest follow-up. Two independent observers analyzed polyethylene wear rates using the computer-assisted Roman 1.70 software. In revision cases, the wear rates were calculated from radiographs prior to revision surgery. A pair student t test was performed to analyze the statistical difference. Two-tailed ρ values less than 0.05 were considered statistically significant.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 460 - 460
1 Nov 2011
Blum YC Ranawat AS Ranawat CS
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Introduction: In 1979, our senior author described his technique for correcting a flexion contracture during total knee arthroplasty (TKA) by additional resection of the distal femur and posterior capsular release; he also described his method of correction of a varus deformity by raising a subperiosteal sleeve from the proximal tibia. Due to concerns related to elevation of the joint line as well as flexion/extension gap asymmetry and instability, our technique has evolved into a methodical soft tissue release at the level of the joint line. Our hypothesis is that this technique effectively corrects both deformities, while reducing the complications related to the more traditional techniques.

The purpose of this study is to describe this technique and assess its effectiveness in a series of 31 consecutive patients.

Technique: Highlights of this technique are as follows:

This method involves osseous resections of 10mm from the level of the uninvolved surfaces of the femur and tibia in order to restore the mechanical axis.

A transverse release of the contracted posterior capsule is performed with electrocautery at the level of the tibial resection from the posterior margin of the superficial medial collateral ligament (MCL) to the posterolateral corner of the tibia.

A controlled lengthening of the superficial MCL is achieved by pie-crusting.

Results: Over a 12 month span, we have corrected these biplanar deformities in 31 knees without residual instability. There were no residual flexion contractures greater than 5 degrees. The maximum varus corrected was 30 degrees, and the maximum flexion contracture corrected was 20 degrees. The mean coronal plane correction was to 5.5 degrees of valgus (range: 1 to 9 degrees).

Discussion: In a series of 31 consecutive patients, this technique was effective in correcting both deformities. We achieved a mean range of motion of 115 degrees, while avoiding elevation of the joint line or instability. Theoretically, this method should result in more optimal knee mechanics than traditional methods. While we are reporting good early results, a prospective, randomized controlled study is needed to better evaluate this technique.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 182 - 182
1 Mar 2008
Ranawat AS Ranawat CS Jose
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Intro: There are few modern reports which document the results of all-polyethylene tibial components in younger, more active patients. The potential benefits of this design are the elimination of backside wear and lower implant cost than modular, metal-backed components.

From January 1992 to the present, 56 TKRs were implanted in 41 patients less than 60 years of age at the time of index surgery using a cemented all-poly tibial component with a PS design. Indications included all patients with osteoarthritis or post-traumatic arthritis without significant tibial bone loss. All patientswere followed prospectively with clinical and radiographic criteria asdefined by the Knee Society. Patient Assessment Questionnaires were used to quantify patient satisfaction, pain, and activity levels.

From January 1992 to the present, 56 TKRs were implanted in 41 patients less than 60 years of age at the time of index surgery using a cemented all-poly tibial component with a PS design. Indications included all patients with osteoarthritis or post-traumatic arthritis without significant tibial bone loss. All patientswere followed prospectively with clinical and radiographic criteria asdefined by the Knee Society. Patient Assessment Questionnaires were used to quantify patient satisfaction, pain, and activity levels.

Discussion: Since the mid 1980s, modular, metal-backed tibial trays have dominated the TKR market based on finite-element analysis studies which demonstrated superior force distribution compared to conventional all-poly components. As a result, backside wear has become an emerging problem and refocused design efforts on unitized components. Our clinical experience indicates an all-poly tibial component fixed with cement provides excellent performance and survivorship even in younger, more active patients.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 184 -
1 Mar 2008
Sharma A Komistek RD Ranawat CS Mahfouz MR Dennis DA
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At present, contact stress analyses of TKA involve in vitro experimental testing. The objective of this project was to develop a parametric mathematical model that determines in vivo contact stresses for subjects implanted with a TKA, under in vivo, dynamic conditions. It is hypothesized that the results from this model will be more representative of in vivo conditions, thus leading to more accurate prediction of TKA bearing surface stresses.

In vivo kinematics were determined for ten subjects implanted with a posterior stabilized TKA during gait and a deep knee bend under fluoroscopic surveillance. Three-dimensional contact positions, determined between the femoral component and the polyethylene insert, were entered into a complicated mathematical model to determine bearing surface forces. In vivo kinematics and kinetics were entered into a deformation model to predict in vivo contact areas between the medial and lateral condyles and tibial insert. The orientation of the femoral and tibial components, the predicted in vivo contact areas, and vectoral information of soft-tissue derived from MRI images were then entered into a mathematical model that predicted in vivo contact stresses between the femoral component and the tibial insert.

This is the first computational model that utilizes fluoroscopy, MRI, deformation characteristics and Kane’s theory of Dynamics to predict in vivo contact stresses. Although previous models have not been validated, this model was validated by comparing the predicted foot/ ground force with the experimentally derived force. This study demonstrates that patellar motion influences forces throughout the lower extremity. The in vivo contact stress values predicted in this initial study were less than the yield strength of polyethylene.