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Bone & Joint Open
Vol. 1, Issue 2 | Pages 8 - 12
18 Feb 2020
Bhimani SJ Bhimani R Smith A Eccles C Smith L Malkani A

Aims

Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology.

Methods

In all, 140 consecutive patients undergoing RA-TKA and 127 consecutive patients undergoing conventional TKA with minimum six-week follow-up were reviewed. Differences in visual analogue scores (VAS) for pain at rest and with activity, postoperative opiate usage, and length of stay (LOS) between the RA-TKA and conventional TKA groups were compared.


The Bone & Joint Journal
Vol. 101-B, Issue 6_Supple_B | Pages 91 - 96
1 Jun 2019
Smith A Denehy K Ong KL Lau E Hagan D Malkani A

Aims

Cephalomedullary nails (CMNs) are commonly used for the treatment of intertrochanteric hip fractures. Total hip arthroplasty (THA) may be used as a salvage procedure when fixation fails in these patients. The aim of this study was to analyze the complications of THA following failed intertrochanteric hip fracture fixation using a CMN.

Patients and Methods

Patients who underwent THA were identified from the 5% subset of Medicare Parts A/B between 2002 and 2015. A subgroup involving those with an intertrochanteric fracture that was treated using a CMN during the previous five years was identified and compared with the remaining patients who underwent THA. The length of stay (LOS) was compared using both univariate and multivariate analysis. The incidence of infection, dislocation, revision, and re-admission was compared between the two groups, using multivariate analysis adjusted for demographic, hospital, and clinical factors.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 12 - 12
1 Oct 2018
Malkani A Eccles C Swiergosz A Smith L
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Introduction

Postoperative pain is a concern for patients undergoing Total Knee Arthroplasty (TKA) and plays an important role in opioid consumption, length of stay, and postoperative function. The purpose of this study was to compare outcomes in patients who underwent primary TKA comparing femoral and sciatic (F+S) combination motor nerve block versus an adductor canal and the interspace between the popliteal artery and the capsule of the posterior knee (ACB+IPACK) combination sensory nerve block.

Methods

100 consecutive primary TKA cases performed by a single surgeon using the same surgical approach and implant design were reviewed. The first 50 patients received F+S nerve blocks and the second 50 received ACB+IPACK blocks preoperatively. Both groups also received total intravenous anesthesia (TIVA). Differences in opioid requirements, length of stay (LOS), distance walked, Western Ontario & McMasters University Osteoarthritis Index (WOMAC), Knee Society (KSS) function scores, Visual Analog Scores (VAS) for pain at rest and with activity, and postoperative complications were analyzed. There were no differences in the groups with respect to age, sex or BMI.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 133 - 133
1 Feb 2017
MacDonald D Caton T Higgs G Malkani A Chen A Mont M Kurtz S
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Background

Sequentially annealed, highly crosslinked polyethylene (HXLPE) has been used clinically in total knee arthroplasty (TKA) for over a decade[1]. However, little is known about the reasons for HXLPE revision, its surface damage mechanisms, or its in vivo oxidative stability relative to conventional polyethylene. We asked whether retrieved sequentially annealed HLXPE tibial inserts exhibited: (1) similar reasons for revision; (2) enhanced resistance to surface damage; and (3) enhanced oxidative stability, when compared with tibial inserts fabricated from conventional gamma inert sterilized polyethylene (control).

Methods

Four hundred and fifty-six revised tibial inserts in two cohorts (sequentially annealed and conventional UHMWPE control) were collected in a multicenter retrieval program between 2000 and 2016. We controlled for implantation time between the two cohorts by excluding tibial inserts with a greater implantation time than the longest term sequentially annealed retrieval (9.5 years). The mean implantation time (± standard deviation) for the sequentially annealed components was 1.9 ± 1.7 years, and for the control inserts, 3.4 ± 2.7 years (Figure 1). Reasons for HXLPE revision were assessed based on medical records, radiographs, and examinations of the retrieved components. Surface damage mechanisms were assessed using the Hood method[2]. Oxidation was measured at the bearing surface, the backside surface, the anterior and posterior faces, as well as the post (when available) using FTIR (ASTM F2102). Surface damage and oxidation analyses were available for 338 of the components. We used nonparametric statistical testing to analyze for differences in oxidation and surface damage when adjusting for polyethylene formulation as a function of implantation time.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 10 - 10
1 May 2016
MacDonald D Schachtner J Chen A Cates H Klein G Mont M Kraay M Malkani A Lee G Hamlin B Rimnac C Kurtz S
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Introduction

Highly crosslinked polyethylene (HXLPE) was clinically introduced approximately a decade and a half ago to reduce polyethylene wear rates and subsequent osteolysis. Clinical and radiographic studies have repeatedly shown increased wear resistance, however concerns of rim oxidation and fatigue fracture remain. Although short to intermediate term retrieval studies of these materials are available, the long-term behavior of these materials remains unclear.

Methods

Between 2000 and 2015, 115 1st generation HXLPE acetabular liners implanted for 5 or more years were collected and analyzed as part of an ongoing, multi-institutional orthopaedic implant retrieval program. There were two material cohorts based on thermal processing (annealed (n=45) and remelted (n=70)). Each cohort was stratified into two more cohorts based on implantation time (5 – 10 years and >10 years). For annealed components, the intermediate-term liners (n=30) were implanted on average (±SD) for 7.3 ± 1.7 years while the long-term liners (n=15) were implanted for 11.3 ± 1.8 years. For remelted components, the intermediate-term liners (n=59) were implanted on average (±SD) for 7.2 ± 1.3 years while the long-term liners (n=11) were implanted for 11.3 ± 1.2 years. For each cohort, the predominant revision reasons were loosening, instability, and infection (Figure 1). Short-term liners (in-vivo <5ys) from previous studies were analyzed using the same protocol for use as a reference.

For oxidation analysis, thin slices (∼200 μm) were taken from the superior/inferior axis and subsequently boiled in heptane for 6 hours to remove absorbed lipids that may interfere with the oxidation analysis. 3mm line profiles (in 100μm increments) were taken perpendicular to the surface at each region of interest. Oxidation indices were calculated according to ASTM 2102. Penetration was measured directly using a calibrated micrometer (accuracy=0.001mm).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 129 - 129
1 May 2016
Kurtz S Arnholt C MacDonald D Higgs G Underwood R Chen A Klein G Hamlin B Lee G Mont M Cates H Malkani A Kraay M Rimnac C
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Introduction

Previous studies of retrieved CoCr alloy femoral heads have identified imprinting of the stem taper surface features onto the interior head bore, leading researchers to hypothesize that stem taper microgrooves may influence taper corrosion. However, little is known about the role of stem taper surface morphology on the magnitude of in vivo corrosion damage. We designed a matched cohort retrieval study to examine this issue.

Methods

From a multi-institutional retrieval collection of over 3,000 THAs, 120 femoral head-stem pairs were analyzed for evidence of fretting and corrosion using a visual scoring technique based on the severity and extent of fretting and corrosion damage observed at the taper. A matched cohort design was used in which 60 CoCr head-stem pairs with a smooth stem taper were matched with 60 CoCr head-stem pairs having a micro-grooved surface, based on implantation time, flexural rigidity, apparent length of taper engagement, and head size. This study was adequately powered to detect a difference of 0.5 in corrosion scores between the two cohorts, with a power of 82% and 95% confidence. Both cohorts included CoCr and Ti-6-4 alloy femoral stems. A high precision roundness machine (Talyrond 585, Taylor Hobson, UK) was used to measure surface morphology and categorize the stem tapers into smooth vs. micro-grooved categories. Fretting and corrosion damage at the head/neck junction was characterized using a modified semi-quantitative adapted from the Goldberg method by three independent observers. This method separated corrosion damage into four visually determined categories: minimal, mild, moderate and severe damage.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 154 - 154
1 Jul 2014
Kurtz S Zielinska O MacDonald D Cates H Mont M Malkani A Parvizi J Kraay M Rimnac C Klein G
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Summary Statement

This study assesses oxidation, mechanical behavior and revision reasons of 2nd generation HXLPE used in total hip and knee arthroplasty. While oxidation was low for both X3 and E1 HXLPEs, oxidative regional variations were detected in the sequentially annealed cohort.

Introduction

First generation highly crosslinked polyethylenes (HXPLEs) have proven successful in lowering both penetration and osteolysis rates. However, 1st generation annealing and remelting thermal stabilization have been associated with in vivo oxidation or reduced mechanical properties. Thus, 2nd generation HXLPEs were developed to improve oxidative stability while still maintaining material properties. Little is known about the in vivo clinical failure modes of these 2nd generation HLXPEs. The purpose of this study was to assess the revision reasons, wear, oxidative stability, and mechanical behavior of retrieved sequentially annealed Vitamin E diffused HXLPE in THA and TKA.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IV | Pages 86 - 86
1 Mar 2012
Bhadra A Abraham R Malkani A
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Aim

To assess clinical outcome of massive rotator cuff tear repair using triceps myotendinous flap.

Method

This is a prospective cohort of 43 patients (24 male, 19 female) with average age of 62 years. The primary indication of surgery was pain. Patients with massive rotator cuff tear involving supraspinatus and infraspinatus, showing retraction and fatty infiltration in MRI were selected. Few (8/43) were with failed surgical treatment and rest had conservative treatment failed. They underwent rotator cuff repair during Feb 1999 to Jan 2004.

The long head of the triceps was detached from the olecranon, rotated 180 degrees from its pivot point with its major vascular pedicle under the deltoid and acromion through the posterior capsule and attached to the greater tuberosity and any remnant of remaining cuff.

All patients were assessed pre-operatively, at 3, 6 and 12 months post-operatively clinically and also using UCLA pain and functional score for shoulder. Shoulder range of motion was assessed before and after the surgery. 24 patients had minimum of 1 year and 19 had 2 year minimum follow-up.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 119 - 119
1 Mar 2010
Urabe K Mabuchi K Malkani A Naramura T Fujita M Aikawa J Itoman M
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Background: It is known that not only the size but also the shape was different between races. We previously compared the distal femur shapes between the American and the Japanese by lateral radiograph and demonstrated the morphological difference in detail. In this study we evaluated the morphologic feature of the lateral and medial condyles separately between the American and the Japanese using MRI in the sagittal plane.

Patients and methods: The subjects were 99 American and 41 Japanese adult women. MRI scan of sagittal section through the distal half of the femur was taken with the slice thickness about 4.0 mm. The envelope curve of each condyle was superimposed to be approximated to an ellipse. The length and inclination of two axes of the ellipse were estimated as the parameters of the statistical comparison.

Results: The ratio major axis/minor axis of the lateral condyles in American women was significantly larger than that in Japanese, while the ratio of the medial condyles in American was significantly smaller. The inclination of the major axis to the anatomical axis of the distal femur in the American lateral condyles were significantly more than that in Japanese lateral condyles, while both the American and Japanese medial condyles showed similar inclination.

Discussion: The morphological feature of both the lateral and medial condyles in American women was significantly different from that in Japanese. The ratio major axis/minor axis and inclination of lateral condyle in American women were different from those in Japanese, while only the ratio was different between the American and Japanese medial condyles. Understanding of these morphological differences between American and Japanese women is beneficial in elucidating discrepancies in normal knee kinematics and in tailoring the design and procedure for successful total knee arthroplasty.


The Journal of Bone & Joint Surgery British Volume
Vol. 77-B, Issue 3 | Pages 351 - 356
1 May 1995
Malkani A Settecerri J Sim F Chao E Wallrichs S

We reviewed retrospectively 50 consecutive total hip arthroplasties with proximal femoral replacement prostheses in 49 patients. All the patients had massive bone loss. There were 31 women and 18 men who had undergone a mean of 3.1 hip operations. At the last review, 15 patients had died and two had been lost to follow-up, so that 32 patients (33 hips) were available for assessment. The mean age of the patients at the time of the operation was 60.6 years. The mean length of clinical follow-up was 11.1 +/- 4 years, and mean radiographic follow-up was 7.6 +/- 3.2 years. The average preoperative Harris hip score was 46 +/- 13 points, which improved to 80 +/- 10 points after one year and to 76 +/- 16 points at the latest follow-up. The most frequent complication was dislocation, which occurred in 11 hips. Four femoral components and seven acetabular prostheses were revised because of aseptic loosening. With revision at the end point, survivorship after total hip arthroplasty with a proximal femoral replacement prosthesis was predicted to be 64% at 12 years. Although our preliminary results of hip salvage with a proximal femoral replacement prosthesis were encouraging, a longer follow-up has shown a higher rate of failure.