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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 40 - 40
10 May 2024
Zhang J Miller R Chuang T
Full Access

Introduction

Distal femur fractures have traditionally been stabilized with either lateral locking plate or retrograde intramedullary nail. Dual-plates and nail-plate combination fixation have the theoretical biomechanical advantage, faster union and allows patients to weight bear immediately.

The aim of this study is to compare single vs combination fixation, and evaluate outcomes and complications.

Method

We retrospectively reviewed all patients over 60, admitted to Christchurch Hospital, between 1st Jan 2016 and 31st Dec 2022, with an AO 33A/33B/33C distal femur fracture. Patient demographics, fracture characteristics, operation details, and follow up data were recorded.

Primary outcomes are union rate, ambulatory status at discharge, and surgical complications. Secondary outcomes include quality of reduction, operation time and rate of blood transfusions.


Arthroscopic management of femoroacetabular impingement (FAI) has become the mainstay of treatment. However, chondral lesions are frequently encountered and have become a determinant of less favourable outcomes following arthroscopic intervention.

The aim of this systematic review and meta-analysis was to assess the outcomes of hip arthroscopy (HA) in patients with FAI and concomitant chondral lesions classified as per Outerbridge.

A systematic search was performed using the PRISMA guidelines on four databases including MEDLINE, EMBASE, Cochrane Library and Web of Science. Studies which included HA as the primary intervention for management of FAI and classified chondral lesions according to the Outerbridge classification were included. Patients treated with open procedures, for osteonecrosis, Legg-Calve-Perthes disease, and previous ipsilateral hip fractures were excluded. From a total of 863 articles, twenty-four were included for final analysis. Demographic data, PROMs, and radiological outcomes and rates of conversion to total hip arthroplasty (THA) were collected. Risk of bias was assessed using ROBINS-I.

Improved post-operative PROMs included mHHS (mean difference:-2.42; 95%CI:-2.99 to −1.85; p<0.001), NAHS (mean difference:-1.73; 95%CI: −2.23 to −1.23; p<0.001), VAS (mean difference: 2.03; 95%CI: 0.93-3.13; p<0.001). Pooled rate of revision surgery was 10% (95%CI: 7%-14%). Most of this included conversion to THA, with a 7% pooled rate (95%CI: 4%-11%).

Patients had worse PROMs if they underwent HA with labral debridement (p=0.015), had Outerbridge 3 and 4 lesions (p=0.012), concomitant lesions of the femoral head and acetabulum lesions (p=0.029). Reconstructive cartilage techniques were superior to microfracture (p=0.042). Even in concomitant lesions of the femoral head and acetabulum, employing either microfracture or cartilage repair/reconstruction provided a benefit in PROMs (p=0.027).

Acceptable post-operative outcomes following HA with labral repair/reconstruction and cartilage repair in patients with FAI and concomitant moderate-to-severe chondral lesions, can be achieved. Patients suffering from Outerbridge 3 and 4 lesions, concomitant acetabular rim and femoral head chondral lesions that underwent HA with labral debridement, had worse PROMs. Reconstructive cartilage techniques were superior to microfracture. Even in concomitant acetabular and femoral head chondral lesions, employing either microfracture or cartilage repair/reconstruction was deemed to provide a benefit in PROMs.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 98 - 98
4 Apr 2023
Lu V Tennyson M Zhang J Zhou A Thahir A Krkovic M
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Fragility ankles fractures in the geriatric population are challenging to manage, due to fracture instability, soft tissue compromise, patient co-morbidities. Traditional management options include open reduction internal fixation, or conservative treatment, both of which are fraught with high complication rates. We aimed to present functional outcomes of elderly patients with fragility ankle fractures treated with tibiotalocalcaneal nails.

171 patients received a tibiotalocalcaneal nail over a six-year period, but only twenty met the inclusion criteria of being over sixty and having poor bone stock, verified by radiological evidence of osteopenia or history of fragility fractures. Primary outcome was mortality risk from co-morbidities, according to the Charlson co-morbidity index (CCI), and patients’ post-operative mobility status compared to pre-operative mobility. Secondary outcomes include intra-operative and post-operative complications, six-month mortality rate, time to mobilisation and union.

The mean age was 77.82 years old, five of whom are type 2 diabetics. The average CCI was 5.05. Thirteen patients returned to their pre-operative mobility state. Patients with low CCI are more likely to return to pre-operative mobility status (p=0.16; OR=4.00).

Average time to bone union and mobilisation were 92.5 days and 7.63 days, respectively. Mean post-operative AOFAS ankle-hindfoot and Olerud-Molander scores were 53.0 (range 17-88) and 50.9 (range 20-85), respectively. There were four cases of broken distal locking screws, and four cases of superficial infection. Patients with high CCI were more likely to acquire superficial infections (p=0.264, OR=3.857). There were no deep infections, periprosthetic fractures, nail breakages, non-unions.

TTC nailing is an effective treatment methodology for low-demand geriatric patients with fragility ankle fractures. This technique leads to low complication rates and early mobilisation. It is not a life-changing procedure, with many able to return to their pre-operative mobility status, which is important for preventing the loss of socioeconomic independence.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 116 - 116
4 Apr 2023
Zhang J Zhu J Zhou A Thahir A Krkovic M
Full Access

Treatment of tibial osteomyelitis can be challenging and lengthy, with numerous complications possible during rehabilitation. We report on the usage of the Taylor Spatial Frame (TSF) for a large cohort of patients, and analyse factors that affect outcomes

Between 2015-2020, 51 patients were treated with TSF for osteomyelitis at a major trauma centre.

Demographic, infection and treatment factors of: age, smoking status, diabetes, and BMI, acute (<6 weeks post injury) or chronic (>6 weeks) osteomyelitis, bacteria isolated, time to debridement, therapy/surgery number of TSF, time TSF was in, antibiotic treatment period, time to partial weight bear (PWB) and full weight bear (FWB) prescriptions, were collected. Outcomes of complications and time to union were obtained.

Radiological union was achieved at mean 11.0 months. Mean follow up was 24.1 months. Six and three patients were further treated with fusion and amputation respectively. Mean treatment time with TSF was 12.1 months. 78% had some complications, with pin site infection, malunion, and non-union being most prevalent.

Univariate factor analysis, multicollinearity diagnostics, then multivariate model construction were performed.

Staphylococcus Epidermidis in bone debridement microbiology was significantly negatively associated with pin site infection (OR 0.093, 95% CI 0.011-0.828) and malunion (OR 0.698, 95% CI 0.573-0.849), and enterococcus with non-union (OR 0.775, 95% CI 0.656-0.916), during the treatment period. Time to union was significantly positively associated with time from admission to debridement (p=0.035), time TSF was in (p=0.021), presence of complications (p=0.045), bone loss complication(p=0.037), time to FWB prescription(p=0.001).

We have analysed the effectiveness of TSF in the treatment of tibial osteomyelitis, and elucidated important injury, treatment and rehabilitation factors that affect outcome. The negative bacterial-complication cross associations could be due to successful eradication as culture specific antibiotics were used postoperatively. Earlier patient full weight bearing could enhance callous formation leading to faster union.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 2 - 2
4 Apr 2023
Zhou A Jou E Bhatti F Modi N Lu V Zhang J Krkovic M
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Open talus fracture are notoriously difficult to manage and they are commonly associated with a high level of complications including non-union, avascular necrosis and infection. Currently, the management of such injuries is based upon BOAST 4 guidelines although there is no suggested definitive management, thus definitive management is based upon surgeon preference. The key principles of open talus fracture management which do not vary between surgeons, however, there is much debate over whether the talus should be preserved or removed after open talus fracture/dislocation and proceeded to tibiocalcaneal fusion.

A review of electronic hospital records for open talus fractures from 2014-2021 returned foureen patients with fifteen open talus fractures. Seven cases were initially managed with ORIF, five cases were definitively managed with FUSION, while the others were managed with alternative methods. We collected patient's age, gender, surgical complications, surgical risk factors and post-treatment functional ability and pain and compliance with BOAST guidelines. The average follow-up of the cohort was four years and one month. EQ-5D-5L and FAAM-ADL/Sports score was used as a patient reported outcome measure. Data was analysed using the software PRISM.

Comparison between FUSION and ORIF groups showed no statistically significant difference in EQ-5D-5L score (P = 0.13), FAAM-ADL (P = 0.20), FAAM-Sport (P = 0.34), infection rate (P = 0.55), surgical times (P = 0.91) and time to weight bearing (P = 0.39), despite a higher proportion of polytrauma and Hawkins III and IV fractures in the FUSION group.

FUSION is typically used as second line to ORIF or failed ORIF. However, there are a lack of studies that directly compared outcome in open talus fracture patients definitively managed with FUSION or ORIF. Our results demonstrate for the first time, that FUSION may not be inferior to ORIF in terms of patient functional outcome, infection rate, and quality-of-life, in the management of patients with open talus fracture patients. Of note, as open talus fractures have increased risks of complications such as osteonecrosis and non-union, FUSION should be considered as a viable option to mitigate these potential complications in these patients.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 100 - 100
4 Apr 2023
Lu V Zhang J Zhou A Thahir A Krkovic M
Full Access

Fracture related infections (FRI) are debilitating complications of musculoskeletal trauma surgery that can result in permanent functional loss or amputation. This study aims to determine risk factors associated with FRI treatment failure, allowing clinicians to optimise them prior to treatment and identify patients at higher risk.

A major trauma centre database was retrospectively reviewed over a six-year period. Of the 102 patients identified with a FRI (66 male, 36 female), 29.4% (n=30) had acute infections (onset <6 weeks post-injury), 34.3% (n=35) had an open fracture. Open fractures were classified using Gustilo-Anderson (GA) classification (type 2:n=6, type 3A:n=16, type 3B:n=10, type 3C:n=3). Patients with periprosthetic infections of the hip and knee joint, those without prior fracture fixation, soft tissue infections, diabetic foot ulcers, pressure sore infections, patients who died within one month of injury, <12 months follow-up were excluded.

FRI treatment failure was defined as either infection recurrence, non-union, or amputation. Lifestyle, clinical, and intra-operative data were documented via retrospective review of medical records. Factors with a P-value of p<0.05 in univariate analysis were included in a stepwise multivariate logistic regression model.

FRI treatment failure was encountered in 35.3% (n=36). The most common FRI site was the femoral shaft (16.7%; n=17), and 15.7% (n=16) presented with signs of systemic sepsis. 20.6% (n=21) had recurrent infection, 9.8% (n=10) had non-union, and 4.9% (n=5) required an amputation. The mean age at injury was 49.71 years old. Regarding cardiovascular risk factors, 37 patients were current smokers (36.3%), 31 patients were diabetics (30.4%), and 32 patients (31.4%) were obese (BMI≥30.0). Average follow-up time was 2.37 (range: 1.04-5.14) years. Risk factors for FRI treatment failure were BMI>30, GA type 3c, and implant retention.

Given that FRI treatment in 35.3% (36/102) ended up in failure, clinicians need to take into account the predictive variables analysed in this study, and implement a multidisciplinary team approach to optimise these factors. This study could aid clinicians to redirect efforts to improve high risk patient management, and prompt future studies to trial adjuvant technologies for patients at higher risk of failure.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 118 - 118
4 Apr 2023
Zhang J Lu V Zhou A Thahir A Krkovic M
Full Access

Open tibial fractures can be difficult to manage, with a range of factors that could affect treatment and outcome. We present a large cohort of patients, and analyse which factors have significant associations with infection outcome. Elucidation will allow clinicians to strive for treatment optimisation, and patients to be advised on likely complications

Open tibia fractures treated at a major trauma centre between 2015-2021 were included. Mean age at injury was 55.4 (range 13-102). Infection status was categorized into no infection, superficial infection, and osteomyelitis.

Age, mode of injury, polytrauma, fibula status, Gustilo-Anderson (GA) classification, wound contamination, time from injury to: first procedure/definitive plastics procedure/definitive fixation, type of definitive fixation, smoking and diabetic status, and BMI, were collected. Multicollinearity was calculated, with highly correlated factors removed. Multinomial logistic regression was performed. Chi Squared testing, with Post Hoc Bonferroni correction was performed for complex categorical factors.

Two hundred forty-four patients with open tibial fractures were included. Forty-five developed superficial infection (18.4%), and thirty-nine developed osteomyelitis (16.0%).

Polytrauma, fibula status, and type of definitive fixation were excluded from the multivariate model due to strong multicollinearity with other variables.

With reference to the non-infected outcome; superficial infection patients had higher BMI (p<0.01), higher GA grade (p<0.01), osteomyelitis patients had longer time to definitive fixation (p=0.049) and time to definitive plastics procedure (p=0.013), higher GA grade (p<0.01), and positive wound contamination(p=0.015).

Poc hoc analysis showed “no infection” was positively associated with GA-I (p=0.029) and GA-II (p<0.01), and negatively associated with GA-IIIC (p<0.01). Osteomyelitis was positively associated with GA-IIIc (p<0.01)

This study investigated the associations between the injury and presentation factors that may affect infection outcome. The variables highlighted are the factors clinicians should give extra consideration to when treating cases, and take preventative measures to optimize treatment and mitigate infection risk.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 59 - 59
10 Feb 2023
Hancock D Morley D Wyatt M Roberts P Zhang J van Dalen J
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When removing femoral cement in revision hip surgery, creating an anterior femoral cortical window is an attractive alternative to extended trochanteric osteotomy. We describe our experience and evolution of this technique, the clinical and radiological results, and functional outcomes.

Between 2006 and 2021 we used this technique in 22 consecutive cases at Whanganui Hospital, New Zealand. The average age at surgery was 74 years (Range 44 to 89 years). 16 cases were for aseptic loosening: six cases for infection.

The technique has evolved to be more precise and since 2019 the combination of CT imaging and 3-D printing technology has allowed patient-specific (PSI) jigs to be created (6 cases). This technique now facilitates cement removal by potentiating exposure through an optimally sized anterior femoral window.

Bone incorporation of the cortical window and functional outcomes were assessed in 22 cases, using computer tomography and Oxford scores respectively at six months post revision surgery. Of the septic cases, five went onto successful stage two procedures, the other to a Girdlestone procedure.

On average, 80% bony incorporation of the cortical window occurred (range 40 −100%). The average Oxford hip score was 37 (range 22 – 48). Functional outcome (Oxford Hip) scores were available in 11 cases (9 pre-PSI jig and 2 using PSI jig). There were two cases with femoral component subsidence (1 using the PSI jig).

This case series has shown the effectiveness of removing a distal femoral cement mantle using an anterior femoral cortical window, now optimized by using a patient specific jig with subsequent reliable bony integration, and functional outcomes comparable with the mean score for revision hip procedures reported in the New Zealand Joint Registry.


Bone & Joint Research
Vol. 11, Issue 6 | Pages 362 - 370
9 Jun 2022
Zhou J He Z Cui J Liao X Cao H Shibata Y Miyazaki T Zhang J

Aims

Osteoarthritis (OA) is a common degenerative joint disease. The osteocyte transcriptome is highly relevant to osteocyte biology. This study aimed to explore the osteocyte transcriptome in subchondral bone affected by OA.

Methods

Gene expression profiles of OA subchondral bone were used to identify disease-relevant genes and signalling pathways. RNA-sequencing data of a bone loading model were used to identify the loading-responsive gene set. Weighted gene co-expression network analysis (WGCNA) was employed to develop the osteocyte mechanics-responsive gene signature.


The Bone & Joint Journal
Vol. 104-B, Issue 5 | Pages 541 - 548
1 May 2022
Zhang J Ng N Scott CEH Blyth MJG Haddad FS Macpherson GJ Patton JT Clement ND

Aims

This systematic review aims to compare the precision of component positioning, patient-reported outcome measures (PROMs), complications, survivorship, cost-effectiveness, and learning curves of MAKO robotic arm-assisted unicompartmental knee arthroplasty (RAUKA) with manual medial unicompartmental knee arthroplasty (mUKA).

Methods

Searches of PubMed, MEDLINE, and Google Scholar were performed in November 2021 according to the Preferred Reporting Items for Systematic Review and Meta-­Analysis statement. Search terms included “robotic”, “unicompartmental”, “knee”, and “arthroplasty”. Published clinical research articles reporting the learning curves and cost-effectiveness of MAKO RAUKA, and those comparing the component precision, functional outcomes, survivorship, or complications with mUKA, were included for analysis.


Bone & Joint Research
Vol. 11, Issue 4 | Pages 214 - 225
20 Apr 2022
Hao X Zhang J Shang X Sun K Zhou J Liu J Chi R Xu T

Aims

Post-traumatic osteoarthritis (PTOA) is a subset of osteoarthritis (OA). The gut microbiome is shown to be involved in OA. However, the effect of exercise on gut microbiome in PTOA remains elusive.

Methods

A total of 18 eight-week Sprague-Dawley rats were assigned into three groups: Sham/sedentary (Sham/Sed), PTOA/sedentary (PTOA/Sed), and PTOA/treadmill-walking (PTOA/TW). PTOA model was induced by transection of the anterior cruciate ligament (ACLT) and the destabilization of the medial meniscus (DMM). Treadmill-walking (15 m/min, 30 min/d, five days/week for eight weeks) was employed in the PTOA/TW group. The response of cartilage, subchondral bone, serology, and gut microbiome and their correlations were assessed.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 45 - 45
1 Dec 2021
Lu V Tennyson M Zhang J Khan W
Full Access

Abstract

Objectives

Tendon and ligament injury poses an increasingly large burden to society. With surgical repair and grafting susceptible to high failure rates, tissue engineering provides novel avenues for treatment. This systematic review explores in vivo evidence whether mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) can facilitate tendon and ligament repair in animal models.

Methods

On May 26th 2021, a systematic search was performed on PubMed, Web of Science, Cochrane Library, Embase, using search terms ‘mesenchymal stem cell’ or ‘multipotent stem cell’ AND ‘extracellular vesicles’ or ‘exosomes’ AND ‘tendon’ or ‘ligament’ or ‘connective tissue’. Risk of bias was assessed using SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) tool. Studies administering EVs isolated from human or animal-derived MSCs into in vivo models of tendon/ligament injury were included. In vitro, ex vivo, in silico studies were excluded, and studies without a control group were excluded. Data on isolation and characterisation of MSCs and EVs, and in vivo findings in animal models were extracted.


Aims

Exosomes derived from bone marrow mesenchymal stem cells (BMSCs) have been reported to be a promising cellular therapeutic approach for various human diseases. The current study aimed to investigate the mechanism of BMSC-derived exosomes carrying microRNA (miR)-136-5p in fracture healing.

Methods

A mouse fracture model was initially established by surgical means. Exosomes were isolated from BMSCs from mice. The endocytosis of the mouse osteoblast MC3T3-E1 cell line was analyzed. CCK-8 and disodium phenyl phosphate microplate methods were employed to detect cell proliferation and alkaline phosphatase (ALP) activity, respectively. The binding of miR-136-5p to low-density lipoprotein receptor related protein 4 (LRP4) was analyzed by dual luciferase reporter gene assay. HE staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry were performed to evaluate the healing of the bone tissue ends, the positive number of osteoclasts, and the positive expression of β-catenin protein, respectively.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 31 - 31
1 Dec 2021
Lu V Zhang J Thahir A Krkovic M
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Abstract

Objectives

Current literature on pilon fracture includes a range of different management strategies, however there is no universal treatment algorithm. We aim to determine clinical outcomes in patients with open and closed pilon fractures, managed using a treatment algorithm applied consistently over the span of this study.

Methods

135 patients over a 6-year period were included. Primary outcome was AOFAS score at 3, 6, 12-months post-injury. Secondary outcomes include time to partial weight-bear (PWB), full weight-bear (FWB), bone union time, follow-up time. AO/OTA classification was used (43A: n=23, 43B: n=30, 43C: n=82). Treatment algorithm consisted of fine wire fixator (FWF) for severely comminuted closed fractures (AO/OTA type 43C3), or open fractures with severe soft tissue injury (GA type 3). Otherwise, open reduction internal fixation (ORIF) was performed. When required, minimally invasive osteosynthesis was performed in combination with FWF to improve joint congruency.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 6 - 6
1 Nov 2021
Lu V Zhang J Thahir A Lim JA Krkovic M
Full Access

Introduction and Objective

Despite the low incidence of pilon fractures among lower limb injuries, their high-impact nature presents difficulties in surgical management and recovery. Current literature includes a wide range of different management strategies, however there is no universal treatment algorithm. We aim to determine clinical outcomes in patients with open and closed pilon fractures, managed using a treatment algorithm that was applied consistently over the span of this study.

Materials and Methods

This retrospective study was conducted at a single institution, including 141 pilon fractures in 135 patients, from August 2014 to January 2021. AO/OTA classification was used to classify fractures. Among closed fractures, 12 had type 43A, 18 had type 43B, 61 had type 43C. Among open fractures, 11 had type 43A, 12 had type 43B, 27 had type 43C. Open fractures were further classified with Gustilo-Anderson (GA); type 1: n=8, type 2: n=10, type 3A: n=12, type 3B: n=20. Our treatment algorithm consisted of fine wire fixator (FWF) for severely comminuted closed fractures (AO/OTA type 43C3), or open fractures with severe soft tissue injury (GA type 3). Otherwise, open reduction internal fixation (ORIF) was performed. When required, minimally invasive osteosynthesis (MIO) was performed in combination with FWF to improve joint congruency. All open fractures, and closed fractures with severe soft tissue injury (skin contusion, fracture blister, severe oedema) were initially treated with temporary ankle-spanning external fixation. For all open fracture patients, surgical debridement, soft tissue cover with a free or pedicled flap were performed. For GA types 1 and 2, this was done with ORIF in the same operating session. Those with severe soft tissue injury (GA type 3) were treated with FWF four to six weeks after soft tissue management was completed. Primary outcome was AOFAS Ankle-Hindfoot score at 3, 6 and 12-months post-treatment. Secondary outcomes include time to partial weight-bear (PWB) and full weight-bear (FWB), bone union time. All complications were recorded.


Bone & Joint Open
Vol. 2, Issue 2 | Pages 111 - 118
8 Feb 2021
Pettit M Shukla S Zhang J Sunil Kumar KH Khanduja V

Aims

The ongoing COVID-19 pandemic has disrupted and delayed medical and surgical examinations where attendance is required in person. Our article aims to outline the validity of online assessment, the range of benefits to both candidate and assessor, and the challenges to its implementation. In addition, we propose pragmatic suggestions for its introduction into medical assessment.

Methods

We reviewed the literature concerning the present status of online medical and surgical assessment to establish the perceived benefits, limitations, and potential problems with this method of assessment.


Bone & Joint Research
Vol. 9, Issue 8 | Pages 501 - 514
1 Aug 2020
Li X Yang Y Sun G Dai W Jie X Du Y Huang R Zhang J

Aims

Rheumatoid arthritis (RA) is a systematic autoimmune disorder, characterized by synovial inflammation, bone and cartilage destruction, and disease involvement in multiple organs. Although numerous drugs are employed in RA treatment, some respond little and suffer from severe side effects. This study aimed to screen the candidate therapeutic targets and promising drugs in a novel method.

Methods

We developed a module-based and cumulatively scoring approach that is a deeper-layer application of weighted gene co-expression network (WGCNA) and connectivity map (CMap) based on the high-throughput datasets.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 30 - 30
1 Jul 2020
Faizan A Zhang J Scholl L
Full Access

Iliopsoas tendonitis after total hip arthroplasty (THA) can be a considerable cause of pain and patient dissatisfaction. The optimal cup position to avoid iliopsoas tendonitis has not been clearly established. Implant designs have also been developed with an anterior recess to avoid iliopsoas impingement. The purpose of this cadaveric study was to determine the effect of cup position and implant design on iliopsoas impingement.

Bilateral THA was performed on three fresh frozen cadavers using oversized (jumbo) offset head center revision acetabular cups with an anterior recess (60, 62 and 66 mm diameter) and tapered wedge primary stems through a posterior approach. A 2mm diameter flexible stainless steel cable was inserted into the psoas tendon sheath between the muscle and the surrounding membrane to identify the location of the psoas muscle radiographically. CT scans of each cadaver were imported in an imaging software. The acetabular shells, cables as well as pelvis were segmented to create separate solid models of each. The offset head center shell was virtually replaced with an equivalent diameter hemispherical shell by overlaying the outer shell surfaces of both designs and keeping the faces of shells parallel. The shortest distance between each shell and cable was measured. To determine the influence of cup inclination and anteversion on psoas impingement, we virtually varied the inclination (30°/40°/50°) and anteversion (10°/20°/30°) angles for both shell designs.

The CT analysis revealed that the original orientation (inclination/anteversion) of the shells implanted in 3 cadavers were as follows: Left1: 44.7°/23.3°, Right1: 41.7°/33.8°, Left2: 40/17, Right2: 31.7/23.5, Left3: 33/2908, Right3: 46.7/6.3. For the offset center shells, the shell to cable distance in all the above cases were positive indicating that there was clearance between the shells and psoas. For the hemispherical shells, in 3 out of 6 cases, the distance was negative indicating impingement of psoas. With the virtual implantation of both shell designs at orientations 40°/10°, 40°/20°, 40°/30° we found that greater anteversion helped decrease psoas impingement in both shell designs. When we analyzed the influence of inclination angle on psoas impingement by comparing wire distances for three orientations (30°/20°, 40°/20°, 50°/20°), we found that the effect was less pronounced. Further analysis comparing the offset head center shell to the conventional hemispherical shell revealed that the offset design was favored (greater clearance between the shell and the wire) in 17 out of 18 cases when the effect of anteversion was considered and in 15 out of 18 cases when the effect of inclinations was considered.

Our results indicate that psoas impingement is related to both cup position and implant geometry. For an oversized jumbo cup, psoas impingement is reduced by greater anteversion while cup inclination has little effect. An offset head center cup with an anterior recess was effective in reducing psoas impingement in comparison to a conventional hemispherical geometry. In conclusion, adequate anteversion is important to avoid psoas impingement with jumbo acetabular shells and an implant with an anterior recess may further mitigate the risk of psoas impingement.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 63 - 63
1 Jul 2020
Zhang J Zhao G Li F Wang JH
Full Access

Tendinopathy is one of the most common orthopaedic pathological conditions characterized by tendon degenerative changes. Excessive mechanical loading is considered as a major causative factor in the development of tendinopathy, but the mechanisms of pathogenesis remain unclear. High mobility group box-1 (HMGB1), a potent inflammatory mediator when released into the matrix, has been identified in the early stage tendinopathy patients. Since the release and contribution of HMGB1 in tendinopathy development due to mechanical overloading is unknown, we investigated the role of HMGB1 in tendinopathy using a mouse intensive treadmill running (ITR) model and injection of glycyrrhizin (GL), a specific inhibitor of HMGB1.

A total of 48 mice were divided into four groups, Cage Control group: The animals were allowed to move freely in their cage, GL group: The animals were received daily IP injection of GL (50 mg/kg body weight) for 24 weeks, ITR group: The animals ran on treadmill at 15 meters/min for three h/ day, five days a week for 12 or 24 weeks, GL+ITR group: The animals ran the same protocol as that of ITR group plus daily IP injection of GL for 12 or 24 weeks. Six mice/group were sacrificed at 12 or 24 weeks and the Achilles and patellar tendon tissues were harvested and used for histochemical staining and immunostaining.

Mechanical overloading induced HMGB1 released from the cell nuclei to the matrix (Fig. 1a, b) caused tendon inflammation (Fig. 1c, d) and led to tendon degenerative changes (Fig. 1e-j). After 12 weeks of ITR, the tendon tissue near the bone insertion site showed typical tendinopathic changes in cell shape, accumulation of glycosaminoglycans (GAG) (Fig. 1e, f), and increase in SOX-9 staining (Fig. 1g-j). After 24 weeks ITR, the distal site of Achilles tendon showed considerable changes in cell shape (Fig. 2A, g, arrows), which is round compared to more elongated in the control and GL groups (Fig. 2A, e, f). However, daily treatment with GL prior to ITR blocked the cell shape change (Fig. 2A, h) and, ITR induced extensive GAG accumulation in ITR group (Fig. 2B, bottom panel). Furthermore, GL inhibited ITR-induced expression of chondrogenic markers (SOX-9 and collagen II) in the tendons (Fig. 3).

Our results showed that mechanical overloading-induced HMGB1 plays a critical role in the development of tendinopathy by initiating tendon inflammation and eventual degeneration characterized by the presence of chondrocyte-like cells, accumulation of proteoglycans, high levels of collagen type II production, and chondrogenic marker SOX-9 expression. These results provide the first evidence for the role of HMGB1 as a therapeutic target to prevent tendinopathy before its onset and block further development at its early inflammation stages. The inhibition of tendinopathy development by GL administration in this study also suggests the putative therapeutic potential of this natural triterpene that is already in clinical use to treat other inflammation-related diseases.

For any figures or tables, please contact authors directly.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 59 - 59
1 Feb 2020
Zhang J Bhowmik-Stoker M Yanoso-Scholl L Condrey C Marchand K Marchand R
Full Access

Introduction

Valgus deformity in an end stage osteoarthritic knee can be difficult to correct with no clear consensus on case management. Dependent on if the joint can be reduced and the degree of medial laxity or distension, a surgeon must use their discretion on the correct method for adequate lateral releases. Robotic assisted (RA) technology has been shown to have three dimensional (3D) cut accuracy which could assist with addressing these complex cases. The purpose of this work was to determine the number of soft tissue releases and component orientation of valgus cases performed with RA total knee arthroplasty (TKA).

Methods

This study was a retrospective chart review of 72 RATKA cases with valgus deformity pre-operatively performed by a single surgeon from July 2016 to December 2017. Initial and final 3D component alignment, knee balancing gaps, component size, and full or partial releases were collected intraoperatively. Post-operatively, radiographs, adverse events, WOMAC total and KOOS Jr scores were collected at 6 months, 1 year and 2 year post-operatively.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 76 - 76
1 Feb 2020
Zhang J Sawires A Matzko C Sodhi N Ehiorobo J Mont M Hepinstall M
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Background

Manually instrumented knee arthroplasty is associated with variability in implant and limb alignment and ligament balance. When malalignment, patellar maltracking, soft tissue impingement or ligament instability result, this can lead to decreased patient satisfaction and early failure. Robotic technology was introduced to improve surgical planning and execution. Haptic robotic-arm assisted total knee arthroplasty (TKA) leverages three-dimensional planning, optical navigation, dynamic intraoperative assessment of soft tissue laxity, and guided bone preparation utilizing a power saw constrained within haptic boundaries by the robotic arm. This technology became clinically available for TKA in 2016. We report our early experience with adoption of this technique.

Methods

A retrospective chart review compared data from the first 120 robotic-arm assisted TKAs performed December 2016 through July 2018 to the last 120 manually instrumented TKAs performed May 2015 to January 2017, prior to introduction of the robotic technique. Level of articular constraint selected, surgical time, complications, hemoglobin drop, length of stay and discharge disposition were collected from the hospital record. Knee Society Scores (KSS) and range of motion (were derived from office records of visits preoperatively and at 2-weeks, 7-weeks and 3-month post-op. Manipulations under anesthesia and any reoperations were recorded.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 44 - 44
1 Feb 2020
Zhang J Bhowmik-Stoker M Yanoso-Scholl L Condrey C Marchand K Hitt K Marchand R
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Introduction

Studies have shown that dissatisfaction following TKA may stem from poor component placement and iatrogenic factors related to variability in surgical execution. A CT-based robotic assisted system (RA) allows surgeons to dynamically balance the joint prior to bone resection. This study aimed to determine if this system could improve TKA planning, reduce soft tissue releases, minimize bone resection, and accurately predict component size in varus knee.

Method

Four hundred and seventy four cases with varus deformity undergoing primary RATKA were enrolled in this prospective, single center and surgeon study. Patient demographics and intraoperative surgical details were collected. Initial and final 3-dimensional alignment, component position, bone resection depths, use of soft tissue releases, knee balancing gaps, and component size were collected intraoperatively. WOMAC and KOOS Jr. scores were collected 6 months, and 1 year postoperatively. Descriptive statistics were applied to determine the changes in these parameters between initial and final values.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 60 - 60
1 Feb 2020
Zhang J Persohn S Bhowmik-Stoker M Otto J Paramasivam M Wahdan A Choplin R Territo P
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Introduction

Component position and overall limb alignment following Total Knee Arthroplasty (TKA) have been shown to influence device survivorship and clinical outcomes. However current methods for measuring post-operative alignment through 2D radiographs and CTs may be prone to inaccuracies due to variations in patient positioning, and certain anatomical configurations such as rotation and flexion contractures. The purpose of this paper is to develop a new vector based method for overall limb alignment and component position measurements using CT. The technique utilizes a new mathematical model to calculate prosthesis alignment from the coordinates of anatomical landmarks. The hypothesis is that the proposed technique demonstrated good accuracy to surgical plan, as well as low intra and inter-observer variability.

Methods

This study received institutional review board approval. A total of 30 patients who underwent robotic assisted TKA (RATKA) at four different sites between March 2017 and January 2018 were enrolled in this prospective, multicenter, non-randomized clinical study. CT scans were performed prior to and 4–6 weeks post-operatively. Each subject was positioned headfirst supine with the legs in a neutral position and the knees at full extension. Three separate CT scans were performed at the anatomical location of the hip, knee, and ankle joint. Hip, knee, and ankle images were viewed in 3D software and the following vertices were generated using anatomical landmarks: Hip Center (HC), Medial Epicondyle Sulcus (MES), Lateral Epicondyle (LE), Femur Center (FC), Tibia Center (TC), Medial Malleolus (MM), Lateral Malleolus (LM), Femur Component Superior (FCS), Femur Component Inferior (FCI), Coronal Femoral Lateral (CFL), Coronal Femoral Medial (CFM), Coronal Tibia Lateral (CTL), and Coronal Tibia Medial (CTM). Limb alignment and component positions were calculated from these vertices using a new mathematical model.

The measurements were compared to the surgeons’ operative plan and component targeted positions for accuracy analysis. Two analysts performed the same measurements separately for inter-observer variability analysis. One of the two analysts repeated the measurements at least 30 days apart to assess intra-observer variability. Correlation analysis was performed on the intra-observer analysis, while Bland Altman analysis was performed on the inter-observer analysis.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 43 - 43
1 Feb 2020
Mont M Kinsey T Zhang J Bhowmik-Stoker M Chen A Orozco F Hozack W Mahoney O
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Introduction

Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes. Robotic-assisted (RA) total knee arthroplasty has demonstrated improved accuracy to plan in cadaver studies compared to conventionally instrumented (manual) TKA, but less clinical evidence has been reported.

The objective of this study was to compare the three-dimensional accuracy to plan of RATKA with manual TKA for overall limb alignment and component position.

Methods

A non-randomized, prospective multi-center clinical study was conducted to compare RATKA and manual TKA at 4 U.S. centers between July 2016 and August 2018. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons’ operative plan for overall limb, femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. We tested the differences of absolute deviation from plan between manual and RATKA groups using stratified Wilcoxon tests, which controlled for study center and accounted for skewed distributions of the absolute values. Alpha was 0.05 two-sided. At the time of this abstract, data collections were completed for two centers (52 manual and 58 RATKA).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 147 - 147
1 Feb 2020
Yang D Huang Y Zhou Y Zhang J Shao H Tang H
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Aims

The incidence of thigh pain with the short stem varies widely across different studies. We aimed to evaluate the incidence and characteristics of post-operative thigh pain after using a particular bladed short stem and its potential risk factors.

Patients and Methods

We respectively reviewed 199 consecutive patients who underwent unilateral total hip replacement using the Tri-lock stem from 2013–2016, of which 168 patients were successfully followed up with minimum two year clinical follow-up. All information about thigh pain and pre- and postoperative HHS score were gathered and all preoperative and immediate postoperative radiographs were available for review. Any complications were recorded.


Bone & Joint Research
Vol. 8, Issue 8 | Pages 405 - 413
1 Aug 2019
Huang J Bao X Xia W Zhu L Zhang J Ma J Jiang N Yang J Chen Q Jing T Liu J Ma D Xu G

Objectives

X-linked hypophosphataemic rickets (XLHR) is a disease of impaired bone mineralization characterized by hypophosphataemia caused by renal phosphate wasting. The main clinical manifestations of the disorder are O-shaped legs, X-shaped legs, delayed growth, and bone pain. XLHR is the most common inheritable form of rickets, with an incidence of 1/20 000 in humans. It accounts for approximately 80% of familial cases of hypophosphataemia and serves as the prototype of defective tubular phosphate (PO43+) transport, due to extra renal defects resulting in unregulated FGF23 activity. XLHR is caused by loss-of-function mutations in the PHEX gene. The aim of this research was to identify the genetic defect responsible for familial hypophosphataemic rickets in a four-generation Chinese Han pedigree and to analyze the function of this mutation.

Methods

The genome DNA samples of all members in the pedigree were extracted from whole blood. We sequenced all exons of the PHEX and FGF23 genes, as well as the adjacent splice site sequence with Sanger sequencing. Next, we analyzed the de novo mutation c.1692 del A of the PHEX gene with an online digital service and investigated the mutant PHEX with SWISS-MODEL, immunofluorescence, and protein stability detection.


Bone & Joint Research
Vol. 8, Issue 2 | Pages 73 - 80
1 Feb 2019
Zhang J Hao X Yin M Xu T Guo F

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides with limited coding potential, which have emerged as novel regulators in many biological and pathological processes, including growth, development, and oncogenesis. Accumulating evidence suggests that lncRNAs have a special role in the osteogenic differentiation of various types of cell, including stem cells from different sources such as embryo, bone marrow, adipose tissue and periodontal ligaments, and induced pluripotent stem cells. Involved in complex mechanisms, lncRNAs regulate osteogenic markers and key regulators and pathways in osteogenic differentiation. In this review, we provide insights into the functions and molecular mechanisms of lncRNAs in osteogenesis and highlight their emerging roles and clinical value in regenerative medicine and osteogenesis-related diseases.

Cite this article: J. Zhang, X. Hao, M. Yin, T. Xu, F. Guo. Long non-coding RNA in osteogenesis: A new world to be explored. Bone Joint Res 2019;8:73–80. DOI: 10.1302/2046-3758.82.BJR-2018-0074.R1.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_13 | Pages 40 - 40
1 Oct 2018
Faizan A Scholl L Zhang J Ries MD
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Introduction

Iliopsoas tendonitis after total hip arthroplasty (THA) can be a considerable cause of pain and patient dissatisfaction. The optimal cup position to avoid iliopsoas tendonitis has not been clearly established. Implant designs have also been developed with an anterior recess to avoid iliopsoas impingement. The purpose of this cadaveric study was to determine the effect of cup position and implant design on iliopsoas impingement.

Materials

Bilateral THA was performed on three fresh frozen cadavers using oversized (jumbo) offset head center revision acetabular cups with an anterior recess (60, 62 and 66 mm diameter) and tapered wedge primary stems through a posterior approach. The relatively large shell sizes were chosen to simulate THA revision cases. At least one fixation screw was used with each shell. A 2mm diameter flexible stainless steel cable was inserted into the psoas tendon sheath between the muscle and the surrounding membrane to identify the location of the psoas muscle radiographically. Following the procedure, CT scans were performed on each cadaver. The CT images were imported in an imaging software for further analysis. The acetabular shells, cables as well as pelvis were segmented to create separate solid models of each. To compare the offset head center shell to a conventional hemispherical shell in the same orientation, the offset head center shell was virtually replaced with an equivalent diameter hemispherical shell by overlaying the outer shell surfaces of both designs and keeping the faces of shells parallel. enabled us to assess the relationship between the conventional shells and the cable. The shortest distance between each shell and cable was measured. To determine the influence of cup inclination and anteversion on psoas impingement, we virtually varied the inclination (30°/40°/50°) and anteversion (10°/20°/30°) angles for both shell designs.


Bone & Joint Research
Vol. 7, Issue 2 | Pages 179 - 186
1 Feb 2018
Wu T Zhang J Wang B Sun Y Liu Y Li G

Objectives

As one of the heat-stable enterotoxins, Staphylococcal enterotoxin C2 (SEC2) is synthesized by Staphylococcus aureus, which has been proved to inhibit the growth of tumour cells, and is used as an antitumour agent in cancer immunotherapy. Although SEC2 has been reported to promote osteogenic differentiation of human mesenchymal stem cells (MSCs), the in vivo function of SCE2 in animal model remains elusive. The aim of this study was to further elucidate the in vivo effect of SCE2 on fracture healing.

Materials and Methods

Rat MSCs were used to test the effects of SEC2 on their proliferation and osteogenic differentiation potentials. A rat femoral fracture model was used to examine the effect of local administration of SEC2 on fracture healing using radiographic analyses, micro-CT analyses, biomechanical testing, and histological analyses.


Bone & Joint Research
Vol. 7, Issue 2 | Pages 173 - 178
1 Feb 2018
Peng X Wu X Zhang J Zhang G Li G Pan X

Osteoporosis is a systemic skeletal disorder characterized by reduced bone mass and deterioration of bone microarchitecture, which results in increased bone fragility and fracture risk. Casein kinase 2-interacting protein-1 (CKIP-1) is a protein that plays an important role in regulation of bone formation. The effect of CKIP-1 on bone formation is mainly mediated through negative regulation of the bone morphogenetic protein pathway. In addition, CKIP-1 has an important role in the progression of osteoporosis. This review provides a summary of the recent studies on the role of CKIP-1 in osteoporosis development and treatment.

Cite this article: X. Peng, X. Wu, J. Zhang, G. Zhang, G. Li, X. Pan. The role of CKIP-1 in osteoporosis development and treatment. Bone Joint Res 2018;7:173–178. DOI: 10.1302/2046-3758.72.BJR-2017-0172.R1.


The Bone & Joint Journal
Vol. 99-B, Issue 7 | Pages 944 - 950
1 Jul 2017
Fan G Fu Q Zhang J Zhang H Gu X Wang C Gu G Guan X Fan Y He S

Aims

Minimally invasive transforaminal lumbar interbody fusion (MITLIF) has been well validated in overweight and obese patients who are consequently subject to a higher radiation exposure. This prospective multicentre study aimed to investigate the efficacy of a novel lumbar localisation system for MITLIF in overweight patients.

Patients and Methods

The initial study group consisted of 175 patients. After excluding 49 patients for various reasons, 126 patients were divided into two groups. Those in Group A were treated using the localisation system while those in Group B were treated by conventional means. The primary outcomes were the effective radiation dosage to the surgeon and the exposure time.


Bone & Joint Research
Vol. 6, Issue 4 | Pages 231 - 244
1 Apr 2017
Zhang J Yuan T Zheng N Zhou Y Hogan MV Wang JH

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Methods

Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.


The Bone & Joint Journal
Vol. 98-B, Issue 2 | Pages 238 - 243
1 Feb 2016
Qian L Li P Wu W Fang Y Zhang J Ouyang J

Aims

This study aimed to determine the relationship between pedicle-lengthening distance and bulge-canal volume ratio in cases of lumbar spinal stenosis, to provide a theoretical basis for the extent of lengthening in pedicle-lengthening osteotomies.

Methods

Three-dimensional reconstructions of CT images were performed for 69 patients (33 men and 36 women) (mean age 49.96 years; 24 to 81). Simulated pedicle-lengthening osteotomies and disc bulge and spinal canal volume calculations were performed using Mimics software.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 8 | Pages 1077 - 1085
1 Aug 2012
Yin Z Zhang J Kan S Wang X

Follow-up radiographs are usually used as the reference standard for the diagnosis of suspected scaphoid fractures. However, these are prone to errors in interpretation. We performed a meta-analysis of 30 clinical studies on the diagnosis of suspected scaphoid fractures, in which agreement data between any of follow-up radiographs, bone scintigraphy, magnetic resonance (MR) imaging, or CT could be obtained, and combined this with latent class analysis to infer the accuracy of these tests on the diagnosis of suspected scaphoid fractures in the absence of an established standard. The estimated sensitivity and specificity were respectively 91.1% and 99.8% for follow-up radiographs, 97.8% and 93.5% for bone scintigraphy, 97.7% and 99.8% for MRI, and 85.2% and 99.5% for CT. The results were generally robust in multiple sensitivity analyses. There was large between-study heterogeneity for the sensitivity of follow-up radiographs and CT, and imprecision about their sensitivity estimates.

If we acknowledge the lack of a reference standard for diagnosing suspected scaphoid fractures, MRI is the most accurate test; follow-up radiographs and CT may be less sensitive, and bone scintigraphy less specific.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 141 - 141
1 Mar 2010
Tong P Qu H He B Ji W Zhang J Jin HT Xiao L Ma Z
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The purpose of this investigation was to prospective compare the results of artificial femoral head replacement with those of treatment with a DHS internal fixation for unstable intertrochanteric fractures in elderly patients.

Sixty-one cases of aged patients with intertrochanteric fractures were randomized into two treatment groups. All patients were followed for a minimum of four years from 9.1999 to 4.2003, 29 patients were treated with artificial femoral head replacement, the other were treated with DHS internal fixation. The clinical results of two ways for the treatment of aged patients with intertrochanteric fractures were observed.

There were no significant differences between the groups in terms of functional outcomes, blood loss, or units of blood transfused. Patients treated with artificial femoral head replacement had a shorter hospital stay and operative time, less time to weight-bearing, fewer general complications, and lower mortality rate compared with those treated with the DHS internal fixation.

We conclude that in elderly patients with an unstable intertrochanteric femoral fracture, a artificial femoral head replacement provides superior clinical outcomes but no advantage with regard to functional outcome when compared with a DHS internal fixation.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_I | Pages 63 - 64
1 Jan 2003
Lovering AM Zhang J Bannister GC Lankester BJA Garneti N MacGowan AP
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Twelve patients undergoing total hip replacements were given 600mg linezolid as a 20min intravenous infusion along with conventional prophylaxis of 1gm cefamandole immediately before surgery. Routine total hip arthroplasty was performed and at timed intervals during surgery, samples of bone, fat, muscle and blood were collected for assay by HPLC analysis. Samples of haematoma fluid that formed around the operation site and further blood samples were also collected at timed intervals following the operation for assay. The penetration of linezolid into bone was rapid with mean levels of 9.1mg/L (95% CI: 7.7–10.6mg/L) achieved at 10min after the infusion, decreasing to 6.3mg/L (95% CI: 3.9–8.6mg/L) at 30min. Correcting for the simultaneous blood concentrations gave values for bone penetration of 51% at 10min, 60% at 20min and 47% at 30min. although the penetration of linezolid into fat was also rapid, mean levels and degree of penetration were approximately 60% of those seen in bone at 10min: 4.5mg/L (95%CI:3–6.1mg/L; penetration 27%) 20min: 5.2mg/L (95% CI:4–6.4mg/L; penetration 37%) and 30min:4.1mg/L (95% CI:3.3–4.8mg/L; penetration 31%). For muscle, the corresponding values were 10min: 10.4mg/L (95%CI:8.1–12.7mg/L; penetration 58%), 20min 13.4mg/L (95%:10.2–16.5mg/L; penetration 94%) and 30min 12mg/L (95% CI:9.2–14.8mg/L; penetration 93%). Mean concentration of linezolid in the haematoma around the operation site were 8.2mg/L at 6–8h and 5.6mg/L at 8–10h after the infusion and 7mg/L at 2–4h following a second 600mg infusion given 12h postoperatively.

We conclude that linezolid exhibits rapid penetration in bone, fat and muscle of patients undergoing hip arthroplasty to achieve levels in excess of the MIC for sensitive organisms (MIC of < _ 4mg/L); with therapeutic levels maintained in the drainage which surrounds the operation site for more than 16h. This pharmaco-kinetic profile is similar to those of agents currently used for the treatment of bone and associated soft tissue infections and suggests a role for linezolid in the management of such patients


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 238 - 238
1 Nov 2002
Cheung K Zhang J Lu D Wong Y Luk K Leong J
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Introduction: Anterior convex epiphysiodesis and posterior concave distraction has not been previously described in the literature for the treatment of thoracolumbar hemivertebrae. We describe our experience with long-term follow-up.

Method: Six consecutive patients with a mean age of 3.4 years were operated on with this technique. Levels of fusion extended two levels above and below the hemi-vertebra, while the instrumentation span the full length of the curve. Further concave distraction was carried out when there was evidence of loosening of the hooks.

Results: The average follow-up was 10.8 years (range 8 to 14). The mean Cobb angle before surgery was 49°, and at the latest follow-up was 26°. There was a mean 41% improvement in the scoliosis. In 5 of these cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction.

Conclusion: The addition of concave distraction provided better correction than convex epiphysiodesis alone. It is technically easier and safer than hemivertebra excision in the correction of such deformities. This method of treatment is recommended for patients with single fully segmented hemivertebrae located at the thoracolumbar junction that has a significant deformity.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 273 - 273
1 Nov 2002
Cheung K Zhang J Lu D Luk K Leong J
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Introduction: Anterior convex epiphysiodesis and posterior concave distraction has not been previously described in the literature for the treatment of thoracolumbar hemivertebrae. We describe our experience with long-term follow-up.

Methods: Six consecutive patients with a mean age of 3.4 years were operated on using this technique. The levels of fusion extended two levels above and below the hemivertebra, while the instrumentation spanned the full length of the curve. Further concave distraction was carried out when there was evidence of loosening of the hooks.

Results: The average follow-up was 10.8 years (range: eight to 14 years). The mean Cobb angle before surgery was 49 degrees, and at the latest follow-up was 26 degrees. There mean improvement in the scoliosis was 41%. In five of these cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction.

Conclusions: The addition of concave distraction provided better correction than convex epiphysiodesis alone. This method of treatment is recommended for patients with single fully segmented hemivertebrae located at the thoracolumbar junction associated with a significant deformity. This method is technically easier and safer than excision of the hemivertebra in the correction of such deformities.