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Bone & Joint Research
Vol. 13, Issue 11 | Pages 647 - 658
12 Nov 2024
Li K Zhang Q

Aims

The incidence of limb fractures in patients living with HIV (PLWH) is increasing. However, due to their immunodeficiency status, the operation and rehabilitation of these patients present unique challenges. Currently, it is urgent to establish a standardized perioperative rehabilitation plan based on the concept of enhanced recovery after surgery (ERAS). This study aimed to validate the effectiveness of ERAS in the perioperative period of PLWH with limb fractures.

Methods

A total of 120 PLWH with limb fractures, between January 2015 and December 2023, were included in this study. We established a multidisciplinary team to design and implement a standardized ERAS protocol. The demographic, surgical, clinical, and follow-up information of the patients were collected and analyzed retrospectively.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 228 - 228
1 Mar 2010
Kamat A Govender M
Full Access

We assessed the rates of fracture healing in a number of patients in Southern Africa where the Human Immunodeficiency Virus (HIV) is highly prevalent. Our aim was to deduce whether rates of union were affected by HIV and its subsequent clinical stages, including the Acquired Immune Deficiency Syndrome (AIDS). We evaluated 2376 patients with Weber B ankle fractures without talar shift. All the patients included in the study were tested for HIV using the Western Blot system and classified according to the WHO classification (Stages I–IV). From the sample group, 829 patients were HIV negative. 729 were HIV positive belonging to Stages I–III, whilst 755 were HIV positive in stage IV of the disease. Patients were all treated conservatively in below knee casts for a minimum of six weeks. All the patients were aged between 20 and 30. All patients were all part of similar socioeconomic circumstances and were non-smokers who used no dietary supplements. From the sample of patients we reviewed, the results were as follows. In the HIV negative category, 56% of patients had fracture union at 4 weeks, 32% had fracture union at 6 weeks, 10.5% had fracture union at eight weeks and 1.5% of patients suffered non-union of the fractures. In the HIV positive group (WHO Stages I–III), 54.7% of patients had fracture union at 4 weeks, 33.7% had fracture union at 6 weeks, 10.2% had fracture union at 8 weeks and 1.26% of patients suffered non-union. From the HIV positive category (WHO Stage IV), 18.28% of patients had fracture union at four weeks, 32.72% had fracture union at 6 weeks, 36.56% had fracture union at 8 weeks and 12.45% of patients suffered non-union of the fractures. Healing and union were described as sufficient callous formation, no further displacement, and no malleolar tenderness at the time of cast removal. In addition to this, the patients must have been able to fully weight bear. There was no significant statistical difference in fracture union between patients who were HIV negative and the patients with HIV stages one to three. There were significant differences between the above mentioned groups and patients with Stage IV HIV/AIDS. In essence, the more progressive the disease, the higher the rates of non-union


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 6 - 6
1 May 2012
S G
Full Access

Introduction. The resurgence of TB worldwide has several underlying causes, but HIV infection has undoubtedly been a key factor in the current TB epidemic. Since TB is endemic in the developing world the influence of HIV is of concern, particularly with the emergence of multi-drug-resistant strains. The remarkable susceptibility of patients with AIDS to develop TB has shown the critical role of CD4 lymphocytes in protective immunity. In the absence of immunological surveillance by CD4 cells, 5-10% of persons with latent foci of TB reactivate each year. Aim. This paper highlights the presentation and outcome following treatment in HIV patients with spinal TB. Methods. 81 HIV+ve patients with spinal tuberculosis were prospectively evaluated between 2006 and 2007. The mean age was 31 years and 63% were females. The thoracic spine was affected in 45, lumbar (33) and cervical (3). Non-contiguous lesions were noted in six patients. Sixty-six (81%) patients had neurological deficit. The mean Hb was (10.1gm/dl), mean WCC 4.9, mean lymphocyte count was 1.8, mean ESR 79mm/h and the mean CD4 count was 268 cell/cumm. Co-morbidities were seen in 68% of patients. All patients were optimised prior to treatment. Posterolateral decompression was performed in 29 cases, anterior decompression (25), needle biopsy (13), incision and drainage 5 and 9 were treated non-operatively. Medication included ARV (72 patients) and anti-TB in all patients. Results. The mean follow-up was 21 months. Eleven (13.5%) patients developed wound infection and one child died. Complete recovery occurred in 23 patients (35%). The mean CD4 count was 341 cell/cumm. Conclusion. The short term results are encouraging. These patients are best managed by a multidisciplinary team to monitor potential complications from dual therapy, to ensure compliance and adequate nutrition


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 115 - 115
1 Jun 2012
Konan S Hossain FS Haddad FS
Full Access

Introduction. There have been concerns regarding the quality of training received by Orthopaedic trainees. There has been a reduction in working hours according to the European working times directive. National targets to reduce surgical waiting lists has increased the workload of consultants, further reducing the trainees' surgical experience. Navigation assisted procedures are successfully used in orthopaedics and provides useful feedback to the surgeon regarding precision of implant placement. We investigated the use of navigation aids as an alternative source of training surgical trainees. Methods. We choose a navigation assisted knee replacement (TKR) model for this study. A first year Orthopaedic registrar level trainee was taught the TKR procedure by a scrubbed consultant in 5 cases. He was then trained in use of non-CT based navigation surgery. The Trainee then performed navigation assisted non-complex primary TKR surgery. A consultant Orthopaedic surgeon was available throughout for advice and support. Data collected included pre and post procedure valgus and varus alignment of the knee, total operative time and WOMAC scores pre and post operatively. Results. A total of 42 TKRs were performed. Intra-operative review by the consultant surgeon was necessary on 3 occasions in the first 10 cases and two occasions in the remaining cases. The average operative time reduced from 184.25 minutes in the first 10 cases to 163.11 minutes in the next 20 cases and 150.33 minutes in the next 12 cases. The varus/valgus alignment was corrected to within 8 degrees in all cases. A significant improvement in WOMAC scores was recorded for all patients (p< 0.05). Conclusion. We believe that this model can be used as a training aid in various orthopaedic surgical procedures


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 9 | Pages 1178 - 1181
1 Sep 2005
Harrison WJ


The Journal of Bone & Joint Surgery British Volume
Vol. 73-B, Issue 5 | Pages 707 - 708
1 Sep 1991
Newton G


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 15 - 15
1 Mar 2006
Günther K
Full Access

With the advent of new hip implants (resurfacing and short stem prosthese) current treatment recommendations have to be reevaluated. The indication for surgical treatment in hip osteoarthritis as well as the choice of implants is mainly based on personal experience of the surgeoun (internal evidence) and clinical data (external evidence). Experimental studies can support the information from clinical trials and are necessary to evaluate the mechanical properties of an implant. They do not replace the clinical evaluation, however.

The level of evidence depends on type, quality and quantity of available data from published investigations. Recent innovations like surface replacement and short stem prostheses have mainly been investigated in single center observational studies with a relatively short followup.

Wider introduction of new implants, however, needs continuous evaluation of clinical and radiographic performance. Examples are given, how this monitoring should be performed in a clinical setting.


The Journal of Bone & Joint Surgery British Volume
Vol. 69-B, Issue 4 | Pages 672 - 673
1 Aug 1987
Crawfurd E Baird P


The Journal of Bone & Joint Surgery British Volume
Vol. 69-B, Issue 1 | Pages 36 - 37
1 Jan 1987
Crawfurd E Baird P Clark A

Five patients known to be HIV (human immunodeficiency virus)-positive--that is, susceptible to AIDS--presented with symptoms initially thought to be indicative of lumbar disc lesions. Signs of nerve root or cauda equina compression were found in all five patients. Lumbar radiculography and, in one patient, computerised tomography produced no evidence of compressive pathology. We recommend that orthopaedic surgeons exercise caution in diagnosing nerve root compression in patients who may be HIV-positive.


The Journal of Bone & Joint Surgery British Volume
Vol. 76-B, Issue 3 | Pages 498 - 499
1 May 1994
McLaughlin Tierney M Harris W


The Bone & Joint Journal
Vol. 105-B, Issue 5 | Pages 534 - 542
1 May 2023
Makaram NS Khan LAK Jenkins PJ Robinson CM

Aims. The outcomes following nonoperative management of minimally displaced greater tuberosity (GT) fractures, and the factors which influence patient experience, remain poorly defined. We assessed the early patient-derived outcomes following these injuries and examined the effect of a range of demographic- and injury-related variables on these outcomes. Methods. In total, 101 patients (53 female, 48 male) with a mean age of 50.9 years (19 to 76) with minimally displaced GT fractures were recruited to a prospective observational cohort study. During the first year after injury, patients underwent experiential assessment using the Disabilities of the Arm, Shoulder and Hand (DASH) score and assessment of associated injuries using MRI performed within two weeks of injury. The primary outcome was the one-year DASH score. Multivariate analysis was used to assess the effect of patient demographic factors, complications, and associated injuries, on outcome. Results. The mean DASH score improved from 42.3 (SD 9.6) at six weeks post-injury, to 19.5 (SD 14.3) at one-year follow-up (p < 0.001), but outcomes were mixed, with 30 patients having a DASH score > 30 at one year. MRI revealed a range of associated injuries, with a full-thickness rotator cuff tear present in 19 patients (19%). Overall, 11 patients (11%) developed complications requiring further operative intervention; 20 patients (21%) developed post-traumatic secondary shoulder stiffness. Multivariate analysis revealed a high-energy mechanism (p = 0.009), tobacco consumption (p = 0.033), use of mobility aids (p = 0.047), a full-thickness rotator cuff tear (p = 0.002), and the development of post-traumatic secondary shoulder stiffness (p = 0.035) were independent predictors of poorer outcome. Conclusion. The results of nonoperative management of minimally displaced GT fractures are heterogeneous. While many patients have satisfactory early outcomes, a substantial subgroup fare much worse. There is a high prevalence of rotator cuff injuries and post-traumatic shoulder stiffness, and their presence is associated with poorer patient experience. Furthermore, patients who have a high-energy injury, smoke, or use walking aids, have worse outcomes. Cite this article: Bone Joint J 2023;105-B(5):534–542


Bone & Joint Open
Vol. 5, Issue 4 | Pages 304 - 311
15 Apr 2024
Galloway R Monnington K Moss R Donaldson J Skinner J McCulloch R

Aims. Young adults undergoing total hip arthroplasty (THA) largely have different indications for surgery, preoperative function, and postoperative goals compared to a standard patient group. The aim of our study was to describe young adult THA preoperative function and quality of life, and to assess postoperative satisfaction and compare this with functional outcome measures. Methods. A retrospective cohort analysis of young adults (aged < 50 years) undergoing THA between May 2018 and May 2023 in a single tertiary centre was undertaken. Median follow-up was 31 months (12 to 61). Oxford Hip Score (OHS) and focus group-designed questionnaires were distributed. Searches identified 244 cases in 225 patients. Those aged aged under 30 years represented 22.7% of the cohort. Developmental dysplasia of the hip (50; 45.5%) and Perthes’ disease (15; 13.6%) were the commonest indications for THA. Results. Preoperatively, of 110 patients, 19 (17.2%) were unable to work before THA, 57 (52%) required opioid analgesia, 51 (46.4%) were reliant upon walking aids, and 70 (63.6%) had sexual activity limited by their pathology. One patient required revision due to instability. Mean OHS was 39 (9 to 48). There was a significant difference between the OHS of cases where THA met expectation, compared with the OHS when it did not (satisfied: 86 (78.2%), OHS: 41.2 (36.1%) vs non-satisfied: 24 (21%), OHS: 31.6; p ≤ 0.001). Only one of the 83 patients (75.5%) who returned to premorbid levels of activity did so after 12 months. Conclusion. Satisfaction rates of THA in young adults is high, albeit lower than commonly quoted figures. Young adults awaiting THA have poor function with high requirements for mobility aids, analgesia, and difficulties in working and undertaking leisure activities. The OHS provided a useful insight into patient function and was predictive of satisfaction rates, although it did not address the specific demands of young adults undertaking THA. Function at one year postoperatively is a good indication of overall outcomes. Cite this article: Bone Jt Open 2024;5(4):304–311


Bone & Joint Open
Vol. 4, Issue 1 | Pages 13 - 18
5 Jan 2023
Walgrave S Oussedik S

Abstract. Robotic-assisted total knee arthroplasty (TKA) has proven higher accuracy, fewer alignment outliers, and improved short-term clinical outcomes when compared to conventional TKA. However, evidence of cost-effectiveness and individual superiority of one system over another is the subject of further research. Despite its growing adoption rate, published results are still limited and comparative studies are scarce. This review compares characteristics and performance of five currently available systems, focusing on the information and feedback each system provides to the surgeon, what the systems allow the surgeon to modify during the operation, and how each system then aids execution of the surgical plan. Cite this article: Bone Jt Open 2023;4(1):13–18


Bone & Joint Open
Vol. 5, Issue 11 | Pages 962 - 970
4 Nov 2024
Suter C Mattila H Ibounig T Sumrein BO Launonen A Järvinen TLN Lähdeoja T Rämö L

Aims. Though most humeral shaft fractures heal nonoperatively, up to one-third may lead to nonunion with inferior outcomes. The Radiographic Union Score for HUmeral Fractures (RUSHU) was created to identify high-risk patients for nonunion. Our study evaluated the RUSHU’s prognostic performance at six and 12 weeks in discriminating nonunion within a significantly larger cohort than before. Methods. Our study included 226 nonoperatively treated humeral shaft fractures. We evaluated the interobserver reliability and intraobserver reproducibility of RUSHU scoring using intraclass correlation coefficients (ICCs). Additionally, we determined the optimal cut-off thresholds for predicting nonunion using the receiver operating characteristic (ROC) method. Results. The RUSHU demonstrated good interobserver reliability with an ICC of 0.78 (95% CI 0.72 to 0.83) at six weeks and 0.77 (95% CI 0.71 to 0.82) at 12 weeks. Intraobserver reproducibility was good or excellent for all analyses. Area under the curve in the ROC analysis was 0.83 (95% CI 0.77 to 0.88) at six weeks and 0.89 (95% CI 0.84 to 0.93) at 12 weeks, indicating excellent discrimination. The optimal cut-off values for predicting nonunion were ≤ eight points at six weeks and ≤ nine points at 12 weeks, providing the best specificity-sensitivity trade-off. Conclusion. The RUSHU proves to be a reliable and reproducible radiological scoring system that aids in identifying patients at risk of nonunion at both six and 12 weeks post-injury during non-surgical treatment of humeral shaft fractures. The statistically optimal cut-off values for predicting nonunion are ≤ eight at six weeks and ≤ nine points at 12 weeks post-injury


Bone & Joint Open
Vol. 4, Issue 2 | Pages 104 - 109
20 Feb 2023
Aslam AM Kennedy J Seghol H Khisty N Nicols TA Adie S

Aims. Patient decision aids have previously demonstrated an improvement in the quality of the informed consent process. This study assessed the effectiveness of detailed written patient information, compared to standard verbal consent, in improving postoperative recall in adult orthopaedic trauma patients. Methods. This randomized controlled feasibility trial was conducted at two teaching hospitals within the South Eastern Sydney Local Health District. Adult patients (age ≥ 18 years) pending orthopaedic trauma surgery between March 2021 and September 2021 were recruited and randomized to detailed or standard methods of informed consent using a random sequence concealed in sealed, opaque envelopes. The detailed group received procedure-specific written information in addition to the standard verbal consent. The primary outcome was total recall, using a seven-point interview-administered recall questionnaire at 72 hours postoperatively. Points were awarded if the participant correctly recalled details of potential complications (maximum three points), implants used (maximum three points), and postoperative instructions (maximum one point). Secondary outcomes included the anxiety subscale of the Hospital and Anxiety Depression Scale (HADS-A) and visual analogue scale (VAS) for pain collected at 24 hours preoperatively and 72 hours postoperatively. Additionally, the Patient Satisfaction Questionnaire Short Form (PSQ-18) measured satisfaction at 72 hours postoperatively. Results. A total of 60 patients were randomized, 32 to the standard group and 28 to the detailed group. Patients in the detailed group had significantly higher total recall score compared to the standard group (mean difference 1.29 points (95% confidence interval (CI) 0.51 to 2.08); p = 0.002). There were no differences in HADS-A (mean difference 0.39 (95% CI -2.11 to 2.88); p = 0.757), VAS pain (mean difference 5.71 (95% CI -22.25 to 11.11); p = 0.499), or PSQ-18 (mean difference 0.499; 95% CI -1.6 to 3.42; p = 0.392). Conclusion. Detailed written tools are useful in improving postoperative recall in adult orthopaedic trauma patients. Cite this article: Bone Jt Open 2023;4(2):104–109


The Bone & Joint Journal
Vol. 104-B, Issue 8 | Pages 987 - 996
1 Aug 2022

Aims. The aim of this study was to describe the demographic details of patients who sustain a femoral periprosthetic fracture (PPF), the epidemiology of PPFs, PPF characteristics, and the predictors of PPF types in the UK population. Methods. This is a multicentre retrospective cohort study including adult patients presenting to hospital with a new PPF between 1 January 2018 and 31 December 2018. Data collected included: patient characteristics, comorbidities, anticoagulant use, social circumstances, level of mobility, fracture characteristics, Unified Classification System (UCS) type, and details of the original implant. Descriptive analysis by fracture location was performed, and predictors of PPF type were assessed using mixed-effects logistic regression models. Results. In total, 720 femoral PPFs from 27 NHS sites were included. PPF patients were typically elderly (mean 79.9 years (SD 10.6)), female (n = 455; 63.2%), had at least one comorbidity (n = 670; 93.1%), and were reliant on walking aids or bed-/chair-bound prior to admission (n = 419; 61.7%). The study population included 539 (74.9%) hip PPFs, 151 (21.0%) knee PPFs, and 30 (4.2%) dividing type PPFs. For hip (n = 407; 75.5%) and knee (n = 88; 58.3%) arthroplasty UCS B type fractures were most common. Overall, 556 (86.2%) were treated in the presenting hospital and 89 (13.8%) required transfer for treatment. Female sex was the only significant predictor of fracture type (A/B1/C type versus B2/B3) for femoral hip PPFs (odds ratio 0.61 (95% confidence interval 0.41 to 0.91); p = 0.014). Sex, residence type, primary versus revision implant PPF, implant fixation, and time between arthroplasty and PPF were not found to predict fracture type for hip PPFs. Conclusion. This multicentre analysis describes patient and injury factors for patients presenting with femoral PPFs to centres across the UK. These patients are generally elderly and frail, comparable to those sustaining a hip fracture. These data can be useful in planning future services and clinical trials. Cite this article: Bone Joint J 2022;104-B(8):987–996


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 32 - 32
10 Feb 2023
Jadav B
Full Access

3D printing techniques have attracted a lot of curiosity in various surgical specialties and the applications of the 3D technology have been explored in many ways including fracture models for education, customized jigs, custom implants, prosthetics etc. Often the 3D printing technology remains underutilized in potential areas due to costs and technological expertise being the perceived barriers. We have applied 3D printing technology for acetabular fracture surgeries with in-house, surgeon made models of mirrored contralateral unaffected acetabulum based on the patients’ trauma CT Scans in 9 patients. The CT Scans are processed to the print with all free-ware modeling software and relatively inexpensive printer by the surgeon and the resulting model is used as a ‘reduced fracture template’ for pre-contouring the standard pelvic reconstruction plates. This allows use of the standard surgical implants, saves time on intra-operative plate contouring, and also aids in reduction to an extent. We share through this presentation the workflow of the freeware softwares to use in order to use this surgical planning and implant preparation that may remove the perceived barriers of cost and technology from surgeons that wish to explore using 3D printing technology for acetabular fracture management and may extend applications to other regions


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 79 - 79
2 Jan 2024
Rasouligandomani M Chemorion F Bisotti M Noailly J Ballester MG
Full Access

Adult Spine Deformity (ASD) is a degenerative condition of the adult spine leading to altered spine curvatures and mechanical balance. Computational approaches, like Finite Element (FE) Models have been proposed to explore the etiology or the treatment of ASD, through biomechanical simulations. However, while the personalization of the models is a cornerstone, personalized FE models are cumbersome to generate. To cover this need, we share a virtual cohort of 16807 thoracolumbar spine FE models with different spine morphologies, presented in an online user-interface platform (SpineView). To generate these models, EOS images are used, and 3D surface spine models are reconstructed. Then, a Statistical Shape Model (SSM), is built, to further adapt a FE structured mesh template for both the bone and the soft tissues of the spine, through mesh morphing. Eventually, the SSM deformation fields allow the personalization of the mean structured FE model, leading to generate FE meshes of thoracolumbar spines with different morphologies. Models can be selectively viewed and downloaded through SpineView, according to personalized user requests of specific morphologies characterized by the geometrical parameters: Pelvic Incidence; Pelvic Tilt; Sacral Slope; Lumbar Lordosis; Global Tilt; Cobb Angle; and GAP score. Data quality is assessed using visual aids, correlation analyses, heatmaps, network graphs, Anova and t-tests, and kernel density plots to compare spinopelvic parameter distributions and identify similarities and differences. Mesh quality and ranges of motion have been assessed to evaluate the quality of the FE models. This functional repository is unique to generate virtual patient cohorts in ASD. Acknowledgements: European Commission (MSCA-TN-ETN-2020-Disc4All-955735, ERC-2021-CoG-O-Health-101044828)


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_15 | Pages 18 - 18
7 Nov 2023
Rankin M Majola S
Full Access

The Disability of Arm Shoulder and Hand (DASH) score questionnaire is a common self-administered tool to assess symptom severity and function in patients with injuries or pathology of the upper limb. However, having such a pertinent tool only in English is limiting in multi-cultural and multilingual populations where English is not always the first language, such as our South African context. IsiZulu is the most widely spoken language in South Africa (approximately 25% of the population). There are certain instances in research, particularly in international studies, where non-English speaking individuals need to be excluded based on translator reliability. This puts our institutions at a disadvantage by not being able to contribute to research. As per the international Institute of Work and Health (IWH), we followed the 5 stage guidelines to achieve the most appropriate linguistic and cultural adapted translation for our setting. (1) Two independent translations from English to isiZulu. (2) A synthesis of the 2 initial translations. (3) Two independent back-translations from the synthesized isiZulu version into English. (4) Expert panel (consisting of university lecturers and official translators) to review all versions and re-create an optimized synthesized version. (5) Pre-testing of the final optimized synthesized version in a pilot study. This rigorous process allowed for a concise and more culturally relevant translation for use in our population. The fourth stage in the process was integral in synthesizing the tool while considering the colloquial and semantic differences and resolving them with appropriate equivalents. The IWH guidelines aids in the cross-cultural adaptation of the DASH score while remaining valid and comparable to the original English version. This is beneficial in multi-national research projects and allows for the standardization of health outcome measures


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_11 | Pages 43 - 43
1 Nov 2022
Nebhani N Kumar G
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Abstract. Extended Trochanteric Osteotomy (ETO) improves surgical exposure and aids femoral stem and bone cement removal in Revision Total Hip Replacement (RTHR) surgery. The aim of this study was to identify healing rates and complications of ETO in RTHR. Methods. From 2012 to 2019 we identified patients who underwent ETO for RTHR. Data collected demographics, BMI, diabetes, anticoagulants, indication for ETO, surgical approach, length of ETO and complications. Descriptive analysis of patient demographics, multiple linear regression analysis was performed to assess ETO complications. Results. There were 63 patients with an average age of 69 years. Indications for ETO were aseptic loosening (30), infection (15), periprosthetic fracture (9), recurrent dislocation (5), broken implant (4). There were 44 cemented and 19 uncemented femoral stem that underwent ETO. Average time from index surgery was 12 years (less than a year to 38 years). All procedures were through posterolateral approach and all ETO were stabilised with cables. Average length of ETO was 12.5cm. BMI varied from 18 to 37. There were 5 diabetics and 16 on anticoagulants. All but one ETO went on to unite. Other complications included infection, dislocations, lateral thigh pain and significant limp. Discussion. Fixation of ETO can be with either wires or cables or plate with cables/screws. Advantages of cables are no irritation over greater trochanter, no disruption of gluteus medius/vastus lateralis continuity, reproducible tension in cables and use of torque limiter minimises loss of tension in cables