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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 25 - 25
10 May 2024
Riyat H Morris H Cheadle C Leatherbarrow A Rae DS Johnson N
Full Access

Introduction

Flexor sheath infections require prompt diagnosis, and management with intravenous antibiotics and/or surgical washout followed by physiotherapy. Complication rates as high as 38% have been reported.

Methods

A retrospective review was carried out of all patients between January 2014 and May 2021 attending with a suspected or confirmed diagnosis of flexor sheath infection. Age, gender, co-morbidities, cause of infection, management, and subsequent complications recorded.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 47 - 47
23 Jun 2023
Garbuz DS
Full Access

The purpose of this study was to determine long-term survival free from all-cause revision and stem-related failure, as well as radiographic and functional outcomes of the ZMR stem in revision THA.

We retrospectively identified all patients in our institutional database who underwent revision THA using the ZMR Revision Hip system from the year 2000 to 2007 (minimum two-year follow-up). Of the 112 ZMR hips (110 patients) identified, a total of 106 hips (104 patients) met inclusion criteria. The mean study follow-up 13.9 years (range 2–22). Indications for index ZMR revision included aseptic loosening (72.1%), periprosthetic joint infection (17.3%), periprosthetic fracture (9.6%), and stem fracture (1.0%). Kaplan-Meier analysis was used to determine the all-cause and stem-related failure revision-free survival. Validated patient reported outcomes were collected and available radiographs were reviewed to determine implant stability.

A total of 17 hips (16.0%) underwent a re-revision of any component. The indications for re-revision were stem failure (35.3%), infection (29.4%), instability (29.4%), and aseptic loosening of the acetabular component (5.9%). The five- and 15-year all-cause survivorship was 89.5% (95% CI 86.5–92.5) and 83.0% (95% CI 79.2–86.8), respectively. There were six re-revisions for stem failure (5.7%); five for stem fracture and one for aseptic loosening. The average time to stem failure was 4.6 years (range 1.3–8.2). The five- and 15-year survivorship free from stem-related failure was 97.2% (95% CI 95.6–98.8) and 93.9% (95% CI 91.5–96.3), respectively. At final follow-up the mean Oxford hip score was 36.9 and all surviving ZMR stems were well fixed on radiographs.

Femoral revision with the ZMR stem offers satisfactory long-term survivorship and promising clinical outcomes. Although uncommon, stem fracture was the most common reason for stem-related failure.


Bone & Joint Open
Vol. 4, Issue 5 | Pages 378 - 384
23 May 2023
Jones CS Eardley WGP Johansen A Inman DS Evans JT

Aims

The aim of this study was to describe services available to patients with periprosthetic femoral fracture (PPFF) in England and Wales, with focus on variation between centres and areas for care improvement.

Methods

This work used data freely available from the National Hip Fracture Database (NHFD) facilities survey in 2021, which asked 21 questions about the care of patients with PPFFs, and nine relating to clinical decision-making around a hypothetical case.


Bone & Joint Open
Vol. 4, Issue 3 | Pages 182 - 187
14 Mar 2023
Sheridan GA Hanlon M Welch-Phillips A Spratt K Hagan R O'Byrne JM Kenny PJ Kurmis AP Masri BA Garbuz DS Hurson CJ

Aims

Hip resurfacing remains a potentially valuable surgical procedure for appropriately-selected patients with optimised implant choices. However, concern regarding high early failure rates continues to undermine confidence in use. A large contributor to failure is adverse local tissue reactions around metal-on-metal (MoM) bearing surfaces. Such phenomena have been well-explored around MoM total hip arthroplasties, but comparable data in equivalent hip resurfacing procedures is lacking. In order to define genetic predisposition, we performed a case-control study investigating the role of human leucocyte antigen (HLA) genotype in the development of pseudotumours around MoM hip resurfacings.

Methods

A matched case-control study was performed using the prospectively-collected database at the host institution. In all, 16 MoM hip resurfacing 'cases' were identified as having symptomatic periprosthetic pseudotumours on preoperative metal artefact reduction sequence (MARS) MRI, and were subsequently histologically confirmed as high-grade aseptic lymphocyte-dominated vasculitis-associated lesions (ALVALs) at revision surgery. ‘Controls’ were matched by implant type in the absence of evidence of pseudotumour. Blood samples from all cases and controls were collected prospectively for high resolution genetic a nalysis targeting 11 separate HLA loci. Statistical significance was set at 0.10 a priori to determine the association between HLA genotype and pseudotumour formation, given the small sample size.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_4 | Pages 17 - 17
3 Mar 2023
Warder H Semple A Johnson DS
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A hip fracture represents the extreme end of osteoporosis, placing a significant burden on secondary care, society, and the individual patient. The National Hip Fracture Database (NHFD) reports each hospital's attainment of the BPT with other measures, along with reporting outcomes. There is clearly wide variability in provision of orthogerriatrician (OG) services across the dataset. Unfortunately, despite overwhelming evidence that provision of an OG service is of benefit, it is presently challenging to recruit to this important specialty within the UK.

Publicly available reports from the NHFD were obtained for each of the 177 participating hospitals for 2017. This was matched with information held within the annual NHFD Facilities Audit for the same period, which include hours of OG support for each hospital. This information was combined with a Freedom of Information request made by email to each hospital for further details concerning OG support. The outcome measures used were Length of Stay (LoS), mortality, and return to usual residence. Comparison was made with provision of OG services by use of Pearson's correlation coefficient. In addition, differences in services were compared between the 25% (44) hospitals delivering outcomes at the extremes for each measure.

Attainment of BPT correlated fairly with LoS (−0.48) and to less of a degree with mortality (−0.1) and return home (0.05). Perioperative medical assessment contributed very strongly with BPT attainment (0.75). In turn perioperative medical assessment correlated fairly with LoS (−0.40) and mortality (−0.23) but not return home (0.02). Provision of perioperative medical assessment attainment was correlated fairly with total OG minutes available per new patient (0.22), total OG minutes available per patient per day (0.29) and number of days per week of OG cover (0.34); with no link for number of patients per orthogeriatrician (0.01). Mortality for the best units were associated with 30% more consultant OG time available per patient per day, and 51% more OG time available per patient. Units returning the most patients to their usual residence had little association with OG time, although had 59% fewer patients per OG, the best units had a 19% longer LoS. For all three measures results for the best had on average 0.5 days per week better routine OG access.

There is no doubt that good quality care gives better results for this challenging group of patients. However, the interaction of BPT, other care metrics, level of OG support and patient factors with outcomes is complex. We have found OG time available per patient per day appears to influence particularly LoS and mortality. Options to increase OG time per patient include reducing patient numbers (ensuring community osteoporosis/falls prevention in place, including reducing in-patient falls); increasing OG time across the week (employing greater numbers/spreading availability over 7 days per week); and reducing LoS. A reduction in LoS has the largest effect of increasing OG time, and although it is dependent on OG support, it is only fairly correlated with this and many other factors play a part, which could be addressed in units under pressure.


Bone & Joint Open
Vol. 4, Issue 3 | Pages 120 - 128
1 Mar 2023
Franco H Saxby N Corlew DS Perry DC Pigeolet M

Aims

Within healthcare, several measures are used to quantify and compare the severity of health conditions. Two common measures are disability weight (DW), a context-independent value representing severity of a health state, and utility weight (UW), a context-dependent measure of health-related quality of life. Neither of these measures have previously been determined for developmental dysplasia of the hip (DDH). The aim of this study is to determine the DW and country-specific UWs for DDH.

Methods

A survey was created using three different methods to estimate the DW: a preference ranking exercise, time trade-off exercise, and visual analogue scale (VAS). Participants were fully licensed orthopaedic surgeons who were contacted through national and international orthopaedic organizations. A global DW was calculated using a random effects model through an inverse-variance approach. A UW was calculated for each country as one minus the country-specific DW composed of the time trade-off exercise and VAS.


Bone & Joint Open
Vol. 3, Issue 9 | Pages 710 - 715
5 Sep 2022
Khan SK Tyas B Shenfine A Jameson SS Inman DS Muller SD Reed MR

Aims

Despite multiple trials and case series on hip hemiarthroplasty designs, guidance is still lacking on which implant to use. One particularly deficient area is long-term outcomes. We present over 1,000 consecutive cemented Thompson’s hemiarthroplasties over a ten-year period, recording all accessible patient and implant outcomes.

Methods

Patient identifiers for a consecutive cohort treated between 1 January 2003 and 31 December 2011 were linked to radiographs, surgical notes, clinic letters, and mortality data from a national dataset. This allowed charting of their postoperative course, complications, readmissions, returns to theatre, revisions, and deaths. We also identified all postoperative attendances at the Emergency and Outpatient Departments, and recorded any subsequent skeletal injuries.


Bone & Joint Open
Vol. 2, Issue 10 | Pages 850 - 857
19 Oct 2021
Blankstein AR Houston BL Fergusson DA Houston DS Rimmer E Bohm E Aziz M Garland A Doucette S Balshaw R Turgeon A Zarychanski R

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Methods

We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma.


Bone & Joint Open
Vol. 2, Issue 6 | Pages 405 - 410
18 Jun 2021
Yedulla NR Montgomery ZA Koolmees DS Battista EB Day CS

Aims

The purpose of our study was to determine which groups of orthopaedic providers favour virtual care, and analyze overall orthopaedic provider perceptions of virtual care. We hypothesize that providers with less clinical experience will favour virtual care, and that orthopaedic providers overall will show increased preference for virtual care during the COVID-19 pandemic and decreased preference during non-pandemic circumstances.

Methods

An orthopaedic research consortium at an academic medical system developed a survey examining provider perspectives regarding orthopaedic virtual care. Survey items were scored on a 1 to 5 Likert scale (1 = “strongly disagree”, 5 = “strongly agree”) and compared using nonparametric Mann-Whitney U test.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 83 - 83
1 Dec 2020
Shah DS Taylan O Labey L Scheys L
Full Access

Understanding the long-term effects of total knee arthroplasty (TKA) on joint kinematics is vital to assess the success of the implant design and surgical procedure. However, while in vitro cadaveric studies quantifying post-operative biomechanics primarily reflect joint behaviour immediately after surgery,1in vivo studies comprising of follow-up TKA patients often reflect joint behaviour a few months after surgery.2 Therefore, the aim of this cadaveric study was to explore the long-term effects of TKA on tibiofemoral kinematics of a donor specimen, who had already undergone bilateral TKA, and compare them to post-operative kinematics reported in the literature.

Two fresh-frozen lower limbs from a single donor (male, age: 83yr, ht: 1.83m, wt: 86kg), who had undergone bilateral TKA (Genesis II, Smith&Nephew, Memphis, USA) 19 years prior to his demise, were obtained following ethical approval from the KU Leuven institutional board. The specimens were imaged using computed tomography (CT) and tested in a validated knee simulator3 replicating active squatting and varus-valgus laxity tests. Tibiofemoral kinematics were recorded using an optical motion capture system and compared to various studies in the literature using the same implant – experimental studies based on cadaveric specimens (CAD)1,4 and an artificial specimen (ART)5, and a computational study (COM)6.

Maximum tibial abduction during laxity tests for the left leg (3.54°) was comparable to CAD (3.30°), while the right leg exhibited much larger joint laxity (8.52°). Both specimens exhibited valgus throughout squatting (left=2.03±0.57°, right=5.81±0.19°), with the change in tibial abduction over the range of flexion (left=1.89°, right=0.64°) comparable to literature (CAD=1.28°, COM=2.43°). The left leg was externally rotated (8.00±0.69°), while the right leg internally rotated (−15.35±1.50°), throughout squatting, with the change in tibial rotation over the range of flexion (left=2.61°, right=4.79°) comparable to literature (CAD=5.52°, COM=4.15°). Change in the femoral anteroposterior translation over the range of flexion during squatting for both specimens (left=14.88mm, right=6.76mm) was also comparable to literature (ART=13.40mm, COM=20.20mm).

Although TKA was reportedly performed at the same time on both legs of the donor by the same surgeon, there was a stark difference in their post-operative joint kinematics. A larger extent of intraoperative collateral ligament release could be one of the potential reasons for higher post-operative joint laxity in the right leg. Relative changes in post-operative tibiofemoral kinematics over the range of squatting were similar to those reported in the literature. However, differences between absolute magnitudes of joint kinematics obtained in this study and findings from the literature could be attributed to different surgeons performing TKA, with presumable variations in alignment techniques and/or patient specific instrumentation, and the slightly dissimilar ranges of knee flexion during squatting.

In conclusion, long-term kinematic effects of TKA quantified using in vitro testing were largely similar to the immediate post-operative kinematics reported in the literature; however, variation in the behaviour of two legs from the same donor suggested that intraoperative surgical alterations might have a greater effect on joint kinematics over time.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 31 - 31
1 Dec 2020
Shah DS Taylan O Berger P Labey L Vandenneucker H Scheys L
Full Access

Orthopaedic training sessions, vital for surgeons to understand post-operative joint function, are primarily based on passive and subjective joint assessment. However, cadaveric knee simulators, commonly used in orthopaedic research,1 could potentially benefit surgical training by providing quantitative joint assessment for active functional motions. The integration of cadaveric simulators in orthopaedic training was explored with recipients of the European Knee Society Arthroplasty Travelling Fellowship visiting our institution in 2018 and 2019. The aim of the study was to introduce the fellows to the knee joint simulator to quantify the surgeon-specific impact of total knee arthroplasty (TKA) on the dynamic joint behaviour, thereby identifying potential correlations between surgical competence and post-operative biomechanical parameters.

Eight fellows were assigned a fresh-frozen lower limb each to plan and perform posterior-stabilised TKA using MRI-based patient-specific instrumentation. Surgical competence was adjudged using the Objective Structured Assessment of Technical Skills (OSATS) adapted for TKA.2 All fellows participated in the in vitro specimen testing on a validated knee simulator,3 which included motor tasks – passive flexion (0°-120°) and active squatting (35°-100°) – and varus-valgus laxity tests, in both the native and post-operative conditions. Tibiofemoral kinematics were recorded with an optical motion capture system and compared between native and post-operative conditions using a linear mixed model (p<0.05). The Pearson correlation test was used to assess the relationship between the OSATS scores for each surgeon and post-operative joint kinematics of the corresponding specimen (p<0.05).

OSATS scores ranged from 79.6% to 100% (mean=93.1, SD=7.7). A negative correlation was observed between surgical competence and change in post-operative tibial kinematics over the entire range of motion during passive flexion – OSATS score vs. change in tibial abduction (r=−0.87; p=0.003), OSATS score vs. change in tibial rotation (r=−0.76; p=0.02). When compared to the native condition, post-operative tibial internal rotation was higher during passive flexion (p<0.05), but lower during squatting (p<0.033). Post-operative joint stiffness was greater in extension than in flexion, without any correlation with surgical competence.

Although trained at different institutions, all fellows followed certain standard intraoperative guidelines during TKA, such as achieving neutral tibial abduction and avoiding internal tibial rotation,4 albeit at a static knee flexion angle. However, post-operative joint kinematics for dynamic motions revealed a strong correlation with surgical competence, i.e. kinematic variability over the range of passive flexion post-TKA was lower for more skilful surgeons. Moreover, actively loaded motions exhibited stark differences in post-operative kinematics as compared to those observed in passive motions. In vitro testing on the knee simulator also introduced the fellows to new quantitative parameters for post-operative joint assessment.

In conclusion, the inclusion of cadaveric simulators replicating functional joint motions could help quantify training paradigms, thereby enhancing traditional orthopaedic training, as was also the unanimous opinion of all participating fellows in their positive feedback.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 19 - 19
1 Oct 2020
Roedel GG Sveom DS Garvin KL
Full Access

Introduction

THA for patient's 50 years and younger is a procedure at high risk for complications and failure because of the high level of activity of this population. Highly cross linked polyethylene (HXLPE) has greatly improved the durability of the implant because of the improved wear characteristics. Few studies have followed this population into the second decade and therefore the purpose of this investigation was to evaluate the clinical outcome for the patients 5o years of age and younger at a minimum of 15 years. The second purpose was to evaluate the radiographic findings secondary to wear or mechanical failure of the implant.

Methods

Between October 1999 and December 2005, 105 THAs were performed in 95 patients (53 female, 42 male) age 50 years and younger (mean 42 years; range 20–50). Ten patients (10 hips) were lost to follow-up or deceased. The remaining 95 hips and 85 patients were followed for a minimum of 15 years (mean of 16.8, range 15–20.5) for analysis. HXLPE (Longevity, Zimmer Biomet) was the acetabular bearing for all hips. Radiographs were evaluated for radiolucent lines and osteolysis.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 5 - 5
1 Oct 2020
Zamora T Garbuz DS Greidanus NV Masri BA
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Introduction

Our objective is to describe early and midterm results with the use of a new knee prosthesis as an articulating spacer in planned two-stage management for infected total knee arthroplasty. As a second objective, we compared outcomes between the group with a retained first stage and those with a completed 2-stage revision.

Methods

Forty-seven patients (48 knees) from January 2012 and November 2017 underwent a 2-stage exchange with an articulating spacer with new implants was used for a chronic knee periprosthetic joint infection with a mean follow-up of 3.7 years (2–6.5 years).

The most frequently identified infecting organism was MSSA (31%), MRSA (21%) or MRSE (20%). At the first stage, a new PS femoral component and a new all-polyethylene posterior stabilized (PS) tibial component or a standard PS tibial liner were cemented with antibiotic-cement, typically 3.6 gm tobramycin and vancomycin 1.5 gm. IV antibiotics for six weeks were administered. The planned reimplantation was at 3 months, but ninetteen spacers (14 all poly tibias and 5 tibial liner) were retained for over 12 months.

Postoperative assessment included knee range of motion (ROM), quality of life (QOL) scores (SF-12, WOMAC, KOOS, Oxford, and UCLA scores), and a satisfaction scale from 0–100%.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 12 - 12
1 Oct 2020
Lamontagne M Catelli DS Cotter B Mazuchi FAS Grammatopoulos G
Full Access

Introduction

Spinopelvic mobility has been associated with THA outcome. To-date spine assessments have been made quasi-statically, using radiographs, in standing and seated positions but dynamic spinopelvic mobility has not been well explored. This study aims to determine the association between dynamic (motion analysis) and quasi-static (radiographic) sagittal assessments and examine the association between axial and sagittal spinal kinematics in hip OA patients and controls.

Methods

This is a prospective, IRB approved, cohort study of 12 patients with hip OA pre-THA (6F/6M, 67±10 years) and six healthy controls (3F/3M, 46±18 years). All underwent lateral spinopelvic radiographs in standing and seated bend-and-reach (SBR) positions. Pelvic tilt (PT), pelvic-femoral-angle (PFA) and lumbar lordosis (LL) angles were measured in both positions and the differences (Δ) in angles between SBR and standing were computed. All participants performed two dynamic tasks at the motion laboratory: seated maximal trunk rotation (STR) and seated bend and reach (SBR). Three-dimensional joint motion data were collected and processed by a 10-camera infrared motion analysis system (Vicon, Nexus 2.10, UK). Total axial and sagittal spine (mid-thoracic to lumbar) range of motion (ROM) were calculated for STR and SBR, respectively.


Bone & Joint Research
Vol. 9, Issue 9 | Pages 601 - 612
1 Sep 2020
Rajagopal K Ramesh S Walter NM Arora A Katti DS Madhuri V

Aims

Extracellular matrix (ECM) and its architecture have a vital role in articular cartilage (AC) structure and function. We hypothesized that a multi-layered chitosan-gelatin (CG) scaffold that resembles ECM, as well as native collagen architecture of AC, will achieve superior chondrogenesis and AC regeneration. We also compared its in vitro and in vivo outcomes with randomly aligned CG scaffold.

Methods

Rabbit bone marrow mesenchymal stem cells (MSCs) were differentiated into the chondrogenic lineage on scaffolds. Quality of in vitro regenerated cartilage was assessed by cell viability, growth, matrix synthesis, and differentiation. Bilateral osteochondral defects were created in 15 four-month-old male New Zealand white rabbits and segregated into three treatment groups with five in each. The groups were: 1) untreated and allogeneic chondrocytes; 2) multi-layered scaffold with and without cells; and 3) randomly aligned scaffold with and without cells. After four months of follow-up, the outcome was assessed using histology and immunostaining.


Bone & Joint Open
Vol. 1, Issue 8 | Pages 500 - 507
18 Aug 2020
Cheruvu MS Bhachu DS Mulrain J Resool S Cool P Ford DJ Singh RA

Aims

Our rural orthopaedic service has undergone service restructure during the COVID-19 pandemic in order to sustain hip fracture care. All adult trauma care has been centralised to the Royal Shrewsbury Hospital for assessment and medical input, before transferring those requiring operative intervention to the Robert Jones and Agnes Hunt Orthopaedic Hospital. We aim to review the impact of COVID-19 on hip fracture workload and service changes upon management of hip fractures.

Methods

We reviewed our prospectively maintained trust database and National Hip Fracture Database records for the months of March and April between the years 2016 and 2020. Our assessment included fracture pattern (intrascapular vs extracapsular hip fracture), treatment intervention, length of stay and mortality.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_13 | Pages 12 - 12
1 Nov 2019
Palo N Chandel SS Borgohain B Patel MK Das DS Srivastav T
Full Access

Acromioclavicular joint is an integral component of Shoulder Complex and common site of injury particularly for athletes involved in sports such as Football, Cricket, Rugby and Shotput. Acromioclavicular Injuries are often neglected and goes untreated especially in low demand patients. Classic surgical techniques are associated with high complication rates.

This is a prospective study from 2015–2017 wherein 32 patients with Acute grade 3, 4, 5, 6 Acromioclavicular joint dislocations, were operated with Minimally Invasive Double Tunnel Anatomical Coraco-clavicular Ligament Reconstruction (DT-ACCLR) with Tightrope Suspensory fixation. Clinical Outcomes were evaluated with Visual Analog Scale, Constant functional scale, Start of Movement, Return to Work, Satisfaction index and Coraco-clavicular distance over 12 months.

Mean follow-up was 14 ± 3.8 months. Visual analog scale and Constant scores revealed significant advancements 0 ± 0.5 (range, 0–2) and 95 ± 3 (range, 92–98) scores at 12 months respectively. The coraco-clavicular distance significantly reduced from 23 ± 2.4 mm to 8 ± 0.5 mm. Mean return to work by 7 days. 98.6% patients were satisfied with surgical results.

We conclude that DT-ACCLR is simple and creative surgical technique which provides stable, reliable and painless AC joint. The patients can move the shoulder same day and return to Work by 5–7days and Sports 3–4 weeks.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 54 - 54
1 Oct 2019
Lamontagne M Catelli DS Beaulé PE
Full Access

Osteochondroplasty procedure for cam deformity provides excellent outcomes on alleviating pain, improving quality of life and clinical function in femoroacetabular impingement syndrome (FAIS) patients. Although medium-term outcomes on gait biomechanics have been reported, it is unclear how it would translate to better hip muscle forces and joint loading in high range of motion tasks. The purpose of this study was to compare the muscle forces and hip joint contact forces (HCF) during a squat task in individuals before and after cam-FAIS surgical correction. Ten cam-FAIS patients prior and 2-years after osteochondroplasty, and 10 BMI- age- and sex-matched healthy control participants (CTRL) underwent 3D motion and ground reaction forces capture while performing a deep squatting task. Muscle and HCF were estimated using musculoskeletal modeling and comparisons were done using statistical parametric mapping (SPM).

Postoperatives squatted down with a higher anterior pelvic tilt and higher hip flexion compared with the preoperatives. Preoperative semimembranosus generated lower forces than the two other groups on the squat ascending, with no differences detected between post-ops and CTRLs. Preoperatives also showed reduced forces for the distal, ischial and medial portions of the adductor magnus relative to the CTRLs, which although reduced, still presented differences postoperatively. Preoperative anterior and medial contact forces were significantly lower than the CTRL group during both phases of the squat. Postoperative vertical and medial forces were also lower compared to the CTRLs. However, with higher vertical forces during the ascent phase of the squat compared to the preoperative, the postoperative group, significantly increased its HCF magnitude. A higher anterior pelvic tilt was associated with an innate restoration of the pelvis position, once the cam deformity no longer existed. The increased force of the semimembranosus muscle while ascending the squat generated higher vertical HCF, which also influenced the increased HCF total magnitude.

For any tables or figures, please contact the authors directly.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 6 - 6
1 Oct 2019
Masri BA Zamora T Garbuz DS Greidanus NV
Full Access

Introduction

The number of medial unicompartmental knee replacements (UKR) performed for arthritis has increased and as such, revisions to total knee replacement (TKR) is increasing. Previous studies have investigated survivorship of UKR to TKR revision and functional outcomes compared to TKR to TKR revision, but have failed to detail the surgical considerations involved in these revisions. Our objectives are to investigate the detailed surgical considerations involved in UKR to TKR revisions.

Methods

This study is a retrospective comparative analysis of a prospectively collected database. From 2005 to 2017, 61 revisions of UKR to TKR were completed at a single center. Our inclusion criteria included: revision of UKR to TKR or TKR to TKR with minimum 1 year follow-up. Our exclusion criteria include: single component and liner revisions and revision for infection. The 61 UKR to TKR revisions were matched 2:1 with respect to age, ASA and BMI to a group of 122 TKR to TKR revisions. The following data was collected: indication for and time to revision, operative skin to skin surgical time, the use of specialized equipment (augment size/location, stem use), intraoperative and postoperative complications, re-operations and outcome scores (WOMAC, Oxford 12, SF 12, satisfaction score).


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 20 - 20
1 Oct 2019
Masri BA Waly F Duncan CP Greidanus NV Garbuz DS
Full Access

Introduction

The practice of overlapping surgery has been increasing in the delivery of orthopaedic care, aiming to provide efficient, high-quality care. However, there have been concerns about the safety of this practice. The purpose of this study is to examine safety and efficacy of a model of partially overlapping surgery that we termed “the swing room” in practice in primary hip and knee arthroplasty.

Methods

A retrospective review of prospectively collected data using an administrative database was carried out on patients who underwent primary unilateral total hip and total knee arthroplasty from 2006 to 2017 at two sites of one academic center staffed by four arthroplasty surgeons. All revisions and bilateral primary procedures were excluded. Cases were stratified as overlapping or non-overlapping. Overlapping was defined when a surgeon had access to two operating rooms with two teams, and non-overlapping was defined as when a surgeon only had access to a single operating room on a particular day. Patient demographic characteristics, operating room time, procedure time, length of stay, Postoperative complications within 30 days of the procedure, unplanned hospital readmissions, unplanned reoperations, and emergency department visits were collected. The Fisher's exact Wilcoxon rank-sum test and logistic regression analysis were used for statistical analysis.