Purpose. of this study is to analyze the results of a modular reconstructive tumor prosthesis for the lower limb (GMRS. (r). ) with a comparative statistical analysis of primary and secondary implants. Material and methods. From October 2003 to September 2007 at Rizzoli 161 GMRS. (r). prostheses were implanted, most after resection of osteosarcoma (94 cases, 58%). It is a modular system with a rotating hinge mechanism for the knee, cemented and uncemented stems, in titanium and chromium-cobalt-molybdenum, curved and straight-fluted, with or without hydroxyapatite coating. Moreover adaptors are available to revise HMRS. (r). implants. This series includes 88 males and 73 females ranging in age from 9 to 80 years. Sites of reconstruction were 109 distal femurs, 19 proximal femurs, 1 total femur and 32 proximal tibias. There were 149 oncologic and 12 non oncologic diagnoses, including 96 primary reconstructions and 65 revisions after failure of previous implant. A retrospective analysis of imaging and complications was performed and functional results assessed according to MSTS system. Statistical analysis with Kaplan-Meier curves was used to study implant survival. Results. At a mean follow up of 2 yrs. 106 patients are continuously NED, 31 are NED after treatment of one or more local recurrence or metastasis, 7 AWD, 5 DWD. There were 10 major complications: 8 infections (4,7%) (5 in primary and 3 in secondary implants, 2 previously infected) and 2 aseptic loosening (1,2%) (1 each). There were 9 minor complications (4 wound sloughs, 1 stiff joint, 3 disrupted extensor apparatus,1 patellar instability) requiring revision. Comparative statistical analysis of primary and secondary implants survival at major complications shows no statistically significant difference. Functional results were good or excellent in 95% of the evaluated patients, without any poor. Conclusions. Middle term results are promising: good function, very low incidence of major complications, no breakage of implant components. This prosthetic reconstruction is indicated in oncological cases as well as in selected in some non oncological settings, such as challenging revisions of prosthetic failures with massive bone loss or post-radiation non unions or allografts failures. Although a higher incidence of complications was expected in secondary implants, statistical analysis shows similar survival

Purpose of this study is to analyze the results of a modular reconstructive tumor prosthesis for the lower limb (GMRS. ®. ) with a comparative statistical analysis of primary and secondary implants. Material and methods: From October 2003 to September 2007 at Rizzoli 161 GMRS. ®. prostheses were implanted, most after resection of osteosarcoma (94 cases, 58%). It is a modular system with a rotating hinge mechanism for the knee, cemented and uncemented stems, in titanium and chromium-cobalt-molybdenum, curved and straight-fluted, with or without hydroxyapatite coating. Moreover adaptors are available to revise HMRS. ®. implants. This series includes 88 males and 73 females ranging in age from 9 to 80 years. Sites of reconstruction were 109 distal femurs, 19 proximal femurs, 1 total femur and 32 proximal tibias. There were 149 oncologic and 12 non oncologic diagnoses, including 96 primary reconstructions and 65 revisions after failure of previous implant. A retrospective analysis of imaging and complications was performed and functional results assessed according to MSTS system. Statistical analysis with Kaplan-Meier curves was used to study implant survival. Results: At a mean follow up of 2 yrs. 106 patients are continuously NED, 31 are NED after treatment of one or more local recurrence or metastasis, 7 AWD, 5 DWD. There were 10 major complications: 8 infections (4,7%) (5 in primary and 3 in secondary implants, 2 previously infected) and 2 aseptic loosening (1,2%) (1 each). There were 9 minor complications (4 wound sloughs, 1 stiff joint, 3 disrupted extensor apparatus,1 patellar instability) requiring revision. Comparative statistical analysis of primary and secondary implants survival at major complications shows no statistically significant difference. Functional results were good or excellent in 95% of the evaluated patients, without any poor. Conclusions: Middle term results are promising: good function, very low incidence of major complications, no breakage of implant components. This prosthetic reconstruction is indicated in oncological cases as well as in selected in some non oncological settings, such as challenging revisions of prosthetic failures with massive bone loss or post-radiation non unions or allografts failures. Although a higher incidence of complications was expected in secondary implants, statistical analysis shows similar survival

Aim: To review the study size and requirements of studies looking at factors affecting outcome following total hip arthroplasty.

Background: The orthopaedic literature is full of claims that new products out-perform older ones, cemented and un-cemented components are equal, cementing grades and mantles are all important and that component orientation is vital to longevity. We are also aware of patients who have performed well despite having numerous adverse features to their joint replacements.

We have searched the available literature for factors that have been implicated in the survival of hip replacements. We have used these to determine the likely study sizes required to provide meaningful data.

Method: We identified over 50 variables that have been implicated in the survival of hip replacements. Assuming all of them to be of equal relevance the study size required for multivariate analysis to be possible would be in excess of 50000. Some of these variables are less likely to be of great significance and this number could potentially be reduced to 25–30000.

Discussion: Because total hip replacement has a greater than 90% success rate at 10 years in nearly all series this makes the numbers required for multivariate analysis much larger. Individual factors affecting survival will be difficult to identify unless large series are considered.

Conclusion: The only way to reduce the numbers required for meaningful studies is to increase the matching of as many variables as possible to ensure that investigators conclusions are valid in the majority of small series orthopaedic studies.

The use of Joint Registers is likely to be the only way of obtaining the volume of data required to detect individual factors affecting survival. Care will still need to be taken interpreting this data as there are still numerous variables which are not accounted for in the Joint Register.

Statistics of the clinical activities of an academic training unit was compiled from 1 January 2005 until 31 December 2005. The statistical study had three purposes. Firstly to determine the pathological profile of the patient population and to determine the distribution of patients who needed acute management versus elective surgery. Secondly to determine the needed staff establishment especially with the future anticipated expanding role of the public health sector in the management of orthopaedic patients. The last aim was to create a model of the clinical activities of a junior orthopaedic surgeon during one year of orthopaedic trauma training.

Detailed statistics were compiled of all the clinical activities at the two hospitals. The one is a tertiary trauma centre, but also functions at a secondary trauma care level. The second hospital is a referral tertiary care orthopaedic hospital where elective surgery takes place. Furthermore the statistics were also compiled in such a way that detailed doctor activities could be processed from it.

There were 181 spinal admissions of which 77 were treated surgically. 106 were treated conservatively. Elective spinal surgery consisted of 20 cases who needed reconstructive surgery and we managed 56 spinal infections. 1263 cases were admitted for orthopaedic trauma management of which 259 had surgery for femur fractures. A total of 250 tibia fractures were treated surgically and a total of 216 radius and ulna fractures. 117 arthroscopic knee procedures were done. A total of 168 arthroplasty cases were treated of which 47 were problem cases.

Pathological profile was determined and gave guidance to clinical studies that should be undertaken. The numbers of some types of injuries that were managed are large. Staff establishment assessment can be done and the expansion of it can be motivated for. A model can be compiled for clinical activities of orthopaedic surgeons in training. Extracted from this statistical analysis an activity list was compiled for an orthopaedic surgeon in training. Amongst other minor cases and excluding Paediatric orthopaedic cases – Femur neck fractures 18, Femur fractures 29, Ankle fractures 53, Humerus fractures 12 and adult Supracondylar humerus fractures 9 and Radius Ulna fractures 34 were done.

Alumina ceramic has been used in total hip arthoplasty since the 70’s and, in the last 30 years, a considerable evolution has occurred in designing the microstructural features of this material, taking advantage of improved processing techniques, as the hot isostatic pressing. As a result, a high degree of densification (> 99.5) has been achieved in materials with a high degree of purity and, especially, with a fine grain size ( 2 microns). The surface stress field acting on a femoral head inoperation is not only due to working conditions, but also to unexpected factors, as local impacts on the surface as a result of partial dislocations, formation of debris, etc. These additional factors greatly contribute to activate degradation mechanisms which, unfortunately, may lead to failure of the implant.

In this study, five alumina femoral heads were investigated, which were retrieved from patients after different periods of time. Among those investigated femoral heads, two belonged to a first-generation type of alumina material with a relatively coarse grainsize (average value 8 microns) and were retrieved due to surface degradation after long periods of implantation (19 and 17 years, respectively); the remaining three implants analyzed were instead recently manufactured implants with a fine grain size; they were retrieved after relatively short periods because of different causes as, for example, cup or stem loosening.

Surface stress analysis using the luminescence of Cr3+impurity in alumina was performed on the retrieved femoral heads and a statistical comparison was attempted among implants with different microstructural characteristics. The investigation led to estimate average residual stress and statistical stress distributions as a function of the location on the femoral head.

The analysis was performed both on the very surface and in the sub-surface of the head, using the confocal and the through-focus configurations of the optical spectrometer, respectively. Different statistical distributions of residual stress were observed in alumina femoral heads with different grain sizes and models were created to understand their dependence on processing and surface loading.

There is conflicting information regarding the recommendations of bracing, physical therapy and cessation of sports for young athletes with symptomatic spondylolysis. The purpose of this study was to identify factors affecting the prognosis and to find the optimal method of non-operative treatment.

The patients in our study were athletes who visited our children's hospital for low back pain with lumbar spondylolysis and were treated non-operatively from 1990 to 2002. Clinical and radiological outcomes were reviewed retrospectively. The effects of bracing, physical therapy, cessation of sports, duration of symptoms before the first hospital visit, lateralisation of spondylolysis, age, gender, onset of low back pain after lumbar trauma during sports, bone scan uptake, vertebral level of the lesion, associated scoliosis or spina bifida and radiological bony healing were analysed using univariate and multivariate analysis with logistic regression. The mean age of patients was 13 years (range 7 to 18 years). The mean follow-up was 4.2 years (range 1.2 to 12 years).

Of 132 patients, 48 patients had excellent results with no pain during sports, 76 good, 6 fair, and 4 poor. Cessation of sports, early non-operative intervention, and a unilateral spondylolysis appeared to be factors associated with excellent outcomes. However, bracing, physical therapy, age, gender, level of lesion, history of trauma, increased uptake on bone scan, or associated scoliosis or spina bifida were not factors. Bony healing was not related to the clinical outcome. The non-operative treatment of spondylolysis in children can yield excellent clinical outcomes, and the absence of bony healing has no influence on clinical outcome. Factors in this study found to correlate with an excellent outcome include unilateral spondylolysis, acute spondylolysis, and treatment with cessation of sports for 12 weeks.

Aims. Traumatic central cord syndrome (CCS) typically follows a hyperextension injury and results in motor impairment affecting the upper limbs more than the lower, with occasional sensory impairment and urinary retention. Current evidence on mortality and long-term outcomes is limited. The primary aim of this study was to assess the five-year mortality of CCS, and to determine any difference in mortality between management groups or age. Methods. Patients aged ≥ 18 years with a traumatic CCS between January 2012 and December 2017 in Wales were identified. Patient demographics and data about injury, management, and outcome were collected. Statistical analysis was performed to assess mortality and between-group differences. Results. A total of 65 patients were identified (66.2% male (n = 43), mean age 63.9 years (SD 15.9)). At a minimum of five years’ follow-up, 32.3% of CCS patients (n = 21) had died, of whom six (9.2%) had died within 31 days of their injury. Overall, 69.2% of patients (n = 45) had been managed conservatively. There was no significant difference in age between conservatively and surgically managed patients (p = 0.062). Kaplan-Meier analysis revealed no significant difference in mortality between patients managed conservatively and those managed surgically (p = 0.819). However, there was a significant difference in mortality between the different age groups (< 50 years vs 50 to 70 years vs > 70 years; p = 0.001). At five years’ follow-up, 55.6% of the patient group aged > 70 years at time of injury had died (n = 15). Respiratory failure was the most common cause of death (n = 9; 42.9%). Conclusion. Almost one-third of patients with a traumatic CCS in Wales had died within five years of their injury. The type of management did not significantly affect mortality but their age at the time of injury did. Further work to assess the long-term functional outcomes of surviving patients is needed to generate more reliable prognostic information. Cite this article: Bone Joint J 2023;105-B(8):920–927

Aims. Hip fractures are some of the most common fractures encountered in orthopaedic practice. We aimed to identify whether perioperative hypotension is a predictor of 30-day mortality, and to stratify patient groups that would benefit from closer monitoring and early intervention. While there is literature on intraoperative blood pressure, there are limited studies examining pre- and postoperative blood pressure. Methods. We conducted a prospective observational cohort study over a one-year period from December 2021 to December 2022. Patient demographic details, biochemical results, and haemodynamic observations were taken from electronic medical records. Statistical analysis was conducted with the Cox proportional hazards model, and the effects of independent variables estimated with the Wald statistic. Kaplan-Meier survival curves were estimated with the log-rank test. Results. A total of 528 patients were identified as suitable for inclusion. On multivariate analysis, postoperative hypotension of a systolic blood pressure (SBP) < 90 mmHg two to 24 hours after surgery showed an increased hazard ratio (HR) for 30-day mortality (HR 4.6 (95% confidence interval (CI) 2.3 to 8.9); p < 0.001) and was an independent risk factor accounting for sex (HR 2.7 (95% CI 1.4 to 5.2); p = 0.003), age (HR 1.1 (95% CI 1.0 to 1.1); p = 0.016), American Society of Anesthesiologists grade (HR 2.7 (95% CI 1.5 to 4.6); p < 0.001), time to theatre > 24 hours (HR 2.1 (95% CI 1.1 to 4.2); p = 0.025), and preoperative anaemia (HR 2.3 (95% CI 1.0 to 5.2); p = 0.043). A preoperative SBP of < 120 mmHg was close to achieving significance (HR 1.9 (95% CI 0.99 to 3.6); p = 0.052). Conclusion. Our study is the first to demonstrate that postoperative hypotension within the first 24 hours is an independent risk factor for 30-day mortality after hip fracture surgery. Clinicians should recognize patients who have a SBP of < 90 mmHg in the early postoperative period, and be aware of the increased mortality risk in this specific cohort who may benefit from a closer level of monitoring and early intervention. Cite this article: Bone Joint J 2024;106-B(2):189–194

Introduction: To train the surgeon adds to the length of procedures and this is currently not accounted for, in the finance received to perform the operation by the hospital.

Objective: Our study focussed on these main questions:

What is the effect on the length of a procedure when a trainee is involved?

Method: Data was taken from two different sources, firstly, the ORMIS theatre system and patient operation notes. These were used to determine the length of six different types of orthopaedic procedures and the level of the main surgeon. This was collected in Stepping Hill hospital, Stockport, United Kingdom between June and July 2008. The second source used was a consultant’s logbook comprising 227 primary total knee replacements between 2004 and 2008.

Results: The data collected via the ORMIS system produced trends suggesting trainees took longer to perform procedures than consultants. The data from the consultant logbook statistically proved this. List times appeared unaffected by trainee presence. In Orthopaedic surgeries, 92% times trainees were present during the procedure and out of this 17% cases were performed by trainees. For total hip replacements done by trainees the procedure took significantly longer surgical time than consultant performed procedures (p = 0.0337).

Among these cases, 71% were performed by senior trainees. The consultant’s log book data also suggested the similar trends. In all comparisions, time taken by trainees to perform surgeries were statistically significant. Trainee performed with consultant scrubbed versus consultant performed (P = < 0.0001), trainee performed with consultant in theatre versus consultant performed(P = 0.0318) and trainee performed with consultant scrubbed versus trainee performed with consultant in theatre (P = 0.002)

Discussion and Conclusion: Hospitals are paid a fixed fees per operation due to introduction of payment by results system as they are paid a fixed tariff for a particular procedure. Training increases the length of a procedure and therefore in an efficient structured environment prevents as many cases being done on a list. Therefore, training future surgeons costs the hospital money. To counter this, training hospitals should be given financial incentives to train in surgery, or procedures performed by trainees should be priced differently to account for the time lost by training.

Purpose of the study: What is the effect on the length of a procedure and the number of procedures performed on the list when a trainee is involved? What percentage of cases had trainee involvement for orthopaedic surgery?

Methods: Data was taken from two different sources, firstly, the ORMIS theatre system and patient operation notes. These were used to determine the length of six different types of orthopaedic procedures and the level of the main surgeon. The second source used was a consultant’s logbook comprising 227 primary total knee replacements between 2004 and 2008.

Results: The data collected via the ORMIS system produced trends suggesting trainees took longer to perform procedures than consultants. The data from the consultant logbook statistically proved this. List times appeared unaffected by trainee presence. In Orthopaedic surgeries, 92% times trainees were present during the procedure and out of this 17% cases were performed by trainees. For total knee replacements done by trainees the procedure took significantly longer surgical time than consultant performed procedures (p = 0.0337).

Among these cases, 71% were performed by senior trainees. The consultant’s log book data also suggested the similar trends. Statistically, trainee performed with consultant scrubbed versus consultant performed (P = < 0.0001), trainee performed with consultant in theatre versus consultant performed(P = 0.0318) and trainee performed with consultant scrubbed versus trainee performed with consultant in theatre (P = 0.002)

Discussion & Conclusion: To train the surgeon adds to the length of procedures and this is currently not accounted for, in the finance received to perform the operation by the hospital.

To counter this, training hospitals should be given financial incentives to train in surgery, or procedures performed by trainees should be priced differently to account for the time lost by training.

From October 2003 to September 2007 at Rizzoli 161 GMRS^® prostheses were implanted after resections of the lower limb. This is a modular system with a knee rotating hinge mechanism, cemented and uncemented stems, in titanium and chromium-cobalt-molybdenum, curved and straight-fluted, with or without hydroxyapatite coating. Adaptors are available to revise HMRS^® prostheses with hybrid implants. This study includes 88 males and 73 females ranging in age from 9 to 80 years. Sites of reconstruction were 109 distal femurs, 19 proximal femurs, 1 total femur and 32 proximal tibias. There were 149 oncologic and 12 non oncologic diagnoses, including 96 primary reconstructions and 65 revisions for failures of previous reconstructions. Analysis of imaging and complications was performed and function assessed according to MSTS system. Kaplan-Meier curves were used to statistically evaluate implant survival.

At a mean follow up of 2.5 yrs. 106 patients are continuously NED, 31 NED after treatment of relapse, 7 AWD, 5 DWD. There were 10 major complications: 8 infections (4.7%) (5 in primary and 3 in secondary implants) and 2 aseptic loosenings (1.2%) (1 each). There were 9 minor complications requiring minor revisions. Comparative statistical analysis of implant survival showed no statistically significant difference between primary and secondary implants. Functional results were good or excellent in 95% of patients, without any poor.

Middle term results are promising with no breakages of implant components. Besides oncological cases, there are selected indications in non oncological settings, such as revisions of prosthetic or allografts failures. While a higher complication rate was expected in secondary implants, statistical analysis shows similar survival.

Purpose: Instability is a major cause of revision total hip arthroplasty (rTHA). It was the third leading cause (5%) after aseptic loosening (75.7%), and infection (7.2%) in the Swedish registry for 2000. The rate of dislocation is however variable depending on the reported series. We conducted a statistical analysis of nearly 3000 files of rTHA to study factors favouring failure.

Material and methods: AVIO, a watch association for orthopaedic implants, was created in 1994 to evaluate factors favouring failure of THA in France, and to furnish statistical data on prosthesis revision. About one hundred orthopaedic surgeons throughout France completed an information card for each revision for a five year period (September 1994 to September 1999). A total of 2926 card were analysed. Patient data (gender, side, number of revisions, age at implantation, age at removal, reason for THA, reason for revision, duration of THA) were cross analysed. The statistical analysis was conducted with chi-square tests and non-parametric tests. Significant results were compared with data in the literature. We present here the results concerning dislocation as the reason for revision.

Results: The rTHA for dislocation accounted for 9.2% of the revisions. Dislocation was the primary reason for revision in patients with repeated revisions and was also the main reason for revision in patients aged over 70 years (20.6%). In this group of older patients, 72.8% of the prostheses were implanted for degenerative disease.

Discussion: The original finding in this study, not clearly reported in the literature, is that dislocation is the primary cause of revision after 70 years, coming before aseptic acetabular loosening. Although mentioned by Charnley in 1979, very few studies (Newington in 1990, Edelund in 1992) have studied the relationship between dislocation and age.

Conclusion: Patient-related factors play an important role in the stability of THA. After 70 years, dislocation becomes the primary reason for revision and should be taken into consideration in our ageing population. This study has led us to modify our therapeutic strategy in patients aged over 70 years.

Introduction

Historically, amputation or rotationplasty were the treatment of choice in skeletally immature patients. The introduction of expandable endoprostheses in the late 1980s offered the advantages of limb-salvage and limb length equality at skeletal maturity and a promising alternative with improved cosmetic results and immediate weight bearing.

Non-linear methods in statistical shape analysis have become increasingly important in orthopedic research as they allow for more accurate and robust analysis of complex shape data such as articulated joints, bony defects and cartilage loss. These methods involve the use of non-linear transformations to describe shapes, rather than the traditional linear approaches, and have been shown to improve the precision and sensitivity of shape analysis in a variety of applications. In orthopedic research, non-linear methods have been used to study a range of topics, including the analysis of bone shape and structure in relation to osteoarthritis, the assessment of joint deformities and their impact on joint function, and the prediction of patient outcomes following surgical interventions. Overall, the use of non-linear methods in statistical shape analysis has the potential to advance our understanding of the relationship between shape and function in the musculoskeletal system and improve the diagnosis and treatment of orthopedic conditions.

Aims

The surgical helmet system (SHS) was developed to reduce the risk of periprosthetic joint infection (PJI), but the evidence is contradictory, with some studies suggesting an increased risk of PJI due to potential leakage through the glove-gown interface (GGI) caused by its positive pressure. We assumed that SHS and glove exchange had an impact on the leakage via GGI.

Aims

Global literature suggests that female surgical trainees have lower rates of independent operating (operative autonomy) than their male counterparts. The objective of this study was to identify any association between gender and lead/independent operating in speciality orthopaedic trainees within the UK national training programme.

Aims

The aim of the study was to determine if there was a direct correlation between the pain and disability experienced by patients and size of their disc prolapse, measured by the disc’s cross-sectional area on T2 axial MRI scans.

Aims

Osteofibrous dysplasia (OFD) is a rare benign lesion predominantly affecting the tibia in children. Its potential link to adamantinoma has influenced management. This international case series reviews the presentation of OFD and management approaches to improve our understanding of OFD.

This annotation briefly reviews the history of artificial intelligence and machine learning in health care and orthopaedics, and considers the role it will have in the future, particularly with reference to statistical analyses involving large datasets.

Cite this article: Bone Joint J 2019;101-B:1476–1478