The reliable production of _in vitro_ chondrocytes that faithfully recapitulate _in vivo_ development would be of great benefit for orthopaedic disease modelling and regenerative therapy(1,2). Current efforts are limited by off-target differentiation, resulting in a heterogeneous product, and by the lack of comparison to human tissue, which precludes detailed evaluation of _in vitro_ cells(3,4).

We performed single-cell RNA-sequencing of long bones dissected from first-trimester fetal limbs to form a detailed ‘atlas’ of endochondral ossification. Through 100-gene in-situ sequencing, we placed each sequenced cell type into its anatomical context to spatially resolve the process of endochondral ossification. We then used this atlas to perform deconvolution on a series of previously published bulk transcriptomes generated from _in vitro_ chondrogenesis protocols to evaluate their ability to accurately produce chondrocytes.

We then applied single-nuclear RNA-sequencing to cells from the best performing protocol collected at multiple time points to allow direct comparison between the differentiation of _in vitro_ and _in vivo_ cells.

We captured 275,000 single fetal cells, profiling the development of chondrocytes from multipotent mesenchymal progenitors to hypertrophic cells at full transcriptomic breadth. Using this atlas as the ground truth for evaluating _in vitro_ cells, we found substantial variability in cell states produced by each protocol, with many showing little similarity to _in vivo_ cells, and all exhibiting off-target differentiation.

Trajectory alignment between _in vivo_ and _in vitro_ single-cell data revealed key differences in gene expression dynamics between _in vitro_ and _in vivo cells,_ with several osteoblastic transcription factors erroneously unregulated _in vitro,_ including _FOXO1._

Using this information, we inhibited _FOXO1_ in culture to successfully increase chondrocyte yield _in vitro._

This study presents a new framework for evaluating tissue engineering protocols, using single-cell data to drive improvement and bring the prospect of true engineered cartilage closer to reality.

Although day surgery has a good patient satisfaction and safety profile, accurate episode-of-care costs (EOCC) calculation for of this procedure compared to standard same-day admission (SDA), while considering functional outcomes, is not well known. This study assesses the EOCC for patients with a THA while comparing DS and Same Day Admission (SDA) (with a 1-day hospitalization) pathways.

The episode-of-care cost (EOCC) of 50 consecutive day surgery and SDA patients who underwent a THA was evaluated. The episode-of-care cost was determined using a bottom-up Time Driven- Activity Based Funding method. Functional outcomes were measured using preoperative and postoperative Harris Hip Score (HHS).

Overall, the SDA THA cost 11% more than a DS THA. The mean total EOCC of DS THA was 9 672 CAD compared to 10 911 CAD in the SDA THA group. Both groups showed an improvement in HHS score following the procedure but patients in the DS group had a significantly higher postoperative HHS score and a significantly greater improvement in their HHS score postoperatively.

Day surgery THA is cost-effective, safe and associated with high patient satisfaction due to functional improvement. Providing policymakers the information to develop optimal financing methods is paramount for clinicians wishing to develop modern protocols, increase productivity while providing the optimal care for patients.

Introduction

Despite the established guidelines on lower extremity free flap reconstruction by the British Orthopaedic Association Standard for Trauma (BOAST-4) the post-operative care has yet to be standardised. There is currently no coherent evidence in the literature regarding clinical monitoring, warming, dangling and compression; the optimal regimes and their respective physiological benefits. The aim of this study is to survey all UK Major Trauma Centres (MTCs) with regards to the post-operative care of lower extremity free flaps and elucidate the current protocols for clinical monitoring, warming, dangling and compression.

This study aimed to identify factors associated with increased rates of blood transfusion in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF).

A retrospective case-control study was performed for AIS patients treated at a large children's hospital between August 2018 and December 2020. All patients with a diagnosis of AIS were evaluated. Data on patient demographics, AIS, and transfusion parameters were collected. Univariate regression and multivariate logistic modeling were utilized to assess risk factors associated with requiring transfusion. Odds ratios (OR) and 95% confidence interval (CI) were calculated. Surgeries were done by three surgeons and thirty anesthesiologists. To quantify the influence of anesthesia practice preferences a categorical variable was defined as “higher-transfusion practice preference”, for the provider with the highest rate of transfusion.

A total of 157 AIS patients were included, of whom 56 were transfused RBC units (cases), and 101 did not receive any RBC transfusion (controls). On univariate analysis, the following variables were significantly correlated with receiving RBC transfusion: “higher-transfusion practice preference,” “administration of crystalloids,” “receiving fresh frozen plasma (FFP),” “receiving platelets,” “pre-operative hemoglobin,” “cell saver volume,” and “surgical time.” On multiple regression modeling, “pre-operative hemoglobin less than 120 g/L” (OR 14.05, 95% CI: 1.951 to 135.7) and “higher-transfusion practice preference” (OR 11.84, 95% CI: 2.505 to 63.65) were found to be meaningfully and significantly predictive of RBC transfusion.

In this cohort, we identified pre-operative hemoglobin of 120 g/L as a critical threshold for requiring transfusion. In addition, we identified significant contribution from anesthesia transfusion practice preferences. Our multivariate model indicated that these two factors are the major significant contributors to allogenic blood transfusion. Although further studies are required to better understand factors contributing to transfusion in AIS patients, we suggest standardized, peri-operative evidence-based strategies to potentially help reduce variations due to individual provider preferences.

For evaluation of orthopaedic biomaterials the closest hostile-like in vitro environments are desirable with relevant control of chemical, biological, mechanical etc. parameters. For faster screening and reduction of time and costs, combination of different critical key parameters in minimal tests is needed. New trends also favour minimisation of in vivo (2010/63/EC, towards replacement technology) and clinical tests (2001/20/EC, 2005/28/EC) for new products yet not compromising risks. Biomaterials manufacturers also are interested in shortening of the time-to-market keeping conformity to essential requirements and withstanding the simulated “worst case” conditions (2003/94/EC). Here we show the new approach of the creation of conditions closest to real life and applications, based on scientifically designed and optimised models, aiming on predictive outputs. With new device and designed protocols, several biomaterials for orthopaedic applications were analysed: titanium, biodegradable fibrous scaffolds and hydrogels. Creation of several favourable conditions for different tissues type formation took place on the surface of the porous titanium specimen. Such conditions could be designed for measurement of the cells proliferation and e.g. simultaneous bacterial adhesion with rather high precision. The method has been compared in independent laboratories for hydrogels with other measuring techniques and shown the benefits of the method especially in more precise control of biomechanical cues. It was observed that significant amount of data are containing in the recorded signals which underlines the importance of correct and holistic data post-processing. The protocols can be furthermore tailored to simulate different conditions, such as for specific positions in tibia, or humeral etc., and combined with patient-specific biomechanics (soft tissues) for customised implant design. The financial support from the Finnish Agency of Innovation (Tekes) is gratefully acknowledged.

Author has no competing financial or conflicting interests.

Aims

To investigate a treatment algorithm of various Ilizarov methods in managing infected tibial non-union.

Introduction

The Ilizarov method for non-union comprises a range of treatment protocols designed to generate tissue, correct deformity, eradicate infection and secure union. The choice of specific reconstruction method is difficult, but should depend on the biological and mechanical needs of the non-union. We present a prospective series of patients with non-union of the tibia managed using a treatment algorithm based on the Ilizarov method and the viability of the non-union.

Chronic back pain is the leading cause of disability worldwide, affecting millions of people. The source of pain is usually the intervertebral disc (IVD), thus there has been a growing interest in developing new improved implants such as disc replacements to treat the condition. However, to ensure the artificial devices being designed replicate the intact disc, the biomechanical behaviour of the IVD must be well understood (Adams and Dolan, 2005). The two most widely used testing procedures in the spinal industry to characterise the behaviour of the disc are the flexibility and the stiffness protocols (Stokes et al, 2002 and Panjabi et al, 1976).

For elastic specimens, the results produced by the flexibility and the stiffness protocols should in theory be identical. However, this does not hold true for inelastic specimens, such as the IVD. For this reason, the custom developed Spine Simulator (Holsgrove et al, 2014) at the University of Bath has been used to compare, in six degrees of freedom, the extent of the difference produced by these two testing protocols.

A biomechanical model of the IVD was tested, which consisted of two cylindrical nylon blocks attached together with a layer of nitrile rubber, representing respectively the vertebral bodies (VB) and the IVD. Two steel pins were inserted into the VB, spanning the thickness of the disc, to ensure the stiffness raise either side of the neutral zone was replicated by the model. Tests were performed at a frequency of 0.1 Hz using triangular wave cycles. The specimen was firstly subjected to the stiffness protocol, characterised by displacements of ±0.5 mm in anterior-posterior and lateral shear, ±0.35 mm in axial compression and ±1.5 deg in all rotational axes. The resulting loads were applied to the specimen when subjected to the flexibility protocol. In addition, the effect of a preload was studied by testing specimens with an axial compressive load of 250 N.

The stiffness matrix was calculated for each test and the main diagonal terms produced for the two protocols were compared using the Mann-Whitney test. Overall, results showed that there was a significant difference in the stiffness terms produced by the two protocols when tests were performed with (p ≤ 0.016) and without (p = 0.004) a preload. The only exception was found in the flexion-extension axis when the test was performed with a preload (p = 0.337). Additionally, differences were also recorded when comparing the shape and linearity of the load-displacement hysteresis curve (Figure 1) and the area enclosed by the curve.

This preliminary study has provided important information regarding the differences in the data produced by the flexibility and the stiffness protocols, it is therefore impractical to compare results produced using these two methods. To ensure that in the future results can be compared across laboratories, there is a need for a standardised testing procedure in the spinal industry.

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The National Institute for Clinical Excellence, UK published guidelines in 2007 encouraging the use of low molecular weight heparin (LMWH) joint replacement surgery. Subsequently, our hospital adopted these guidelines in the treatment of total hip replacements. This study is based on our prospective database of total hip replacements between 2005 and 2009 and compares the complication and mortality rates pre- and post institution of the NICE guidelines.

We analysed prospectively collected data on 686 patients who underwent a primary total hip replacement done by a single surgeon between January 2005 and April 2009. We compared the incidence of mortality, pulmonary embolism, myocardial infarction and intracranial bleeding between the two groups. Prior to the guidelines, all patients were treated for the duration of their admission with 75mg aspirin followed by 4 weeks after discharge. Subsequent to the guidelines, the treatment changed to 40mg of LMWH (Clexane) while an inpatient with aspirin being prescribed for 4 weeks on discharge. Patients unable to tolerate aspirin were treated with low molecular weight heparin. High risk patients (previous pulmonary embolism, previous deep vein thrombosis, family history) were treated with 6 weeks of warfarin. Each patients was reviewed at 8 weeks and 6 months following surgery, and adverse incidents were documented at each review or incident.

Results: 686 patients were identified from the study – 328 pre and 358 post implementation of the NICE guidelines. In the pre-guideline group the mortality was 0.6%, with the incidence of pulmonary embolism being 0.3%, myocardial infarction 0.9% and intracranial bleed 0.3%. Both complications of myocardial infarction occurred early in the post-operative stage and were fatal. The post-guideline group had a mortality rate of 0.2%, with the incidence of pulmonary embolism being 0.2% and intracranial bleeding 0.2%. No myocardial infarctions were noted in this group. The single death was as a result of an intracranial bleed. The was no significant statistical difference in the incidence of mortality, pulmonary embolism, myocardial infarction or intracranial bleeding between the two groups (p value > 0.05, 95% confidence interval). There were no complications in the warfarinised patients of which there were equal numbers in both groups (16).

Conclusion: This study has shown that the change in thromboprophylaxis has not had a significant effect on complication rates in primary total hip replacements and that our mortality rate (0.4%) compares favourably with recent literature. The lack of complications in the war-farinised group probably reflects that high risk patients were identified in the screening process and commenced on warfarin early in the post operative period. Note must be made of the single death due to an intracranial bleed while on low molecular weight heparin.

Introduction Surgeons request cross-match based on habit not evidence. The spinal unit requested 686 units of blood during 2002–2003 and transfused only 42 for elective lumbar spine surgery. This wastes money, time and blood.

Aim Optimise the transfusion requests in elective lumbar spinal surgery by creating evidence based guidelines.

Methods The data on elective operations performed on the lumbar spine during the period June 2002 to June 2003 was collected from the spinal unit database and cross-referenced with the records of blood transfusion. Cross-match: Transfusion ratios (C:T Ratio) and Transfusion Index (TI) for common procedures were calculated. Based on these results, a Maximum Surgical Blood Ordering Schedule (MSBOS) was created and prospectively audited for six months.

Conclusion Eighty units were cross-matched during the prospective audit. Therefore, in one year one hundred and sixty units would be requested. This represents a reduction of over five hundred units.

Introduction

Pelvic and acetabular injuries are relatively rare and surgical reconstruction usually occurs only in specialist centres. As part of their work up there is a local protocol for radiological investigations including Judet oblique views for acetabular fractures, pelvic inlet and outlet for pelvic ring fractures and urethrograms for sustaining anterior pelvic injury. The aim of this service evaluation was to assess whether patients had these radiological investigations prior to transfer.

Background: Control of acute postoperative pain remains a serious problem. Postoperative pain is associated with an increase in thrombotic or respiratory complications. In the other hand the association between surgery, acute postoperative pain and ongoing chronic pain is well defined.

Target: To evaluate the incidence of severe pain after surgery for degenerative lumbar pain, with two analgesic techniques; intravenous analgesia (i.v.) (group 1) and patient controlled analgesia (PCA) (group 2).

Study design: Retrospective study with dates obtains prospectively.

Patient sample: We studied 206 patients operated between january 04 and june 05. Group 1 (intravenous) 80 patients and 126 in group 2 (PCA).

Outcomes mesasures: Percentage of patients with severe pain, number of rescues and complications.

Materials and methods: The type of postoperative analgesia administrated was decided by the anaesthesiologist. To measure pain intensity the VAS was assessed every 6 hours and worst score was used, excluding recovery room. Type of rescue analgesia was the same in all patients and these was recommended in VAS > 3. We evaluate sex, age and comorbidity by ASA. We have defining analgesic ‘failure’ by the overall incidence of pain intensity in two categories: the percentage of patients who experienced moderate-severe pain (VAS > 3) and severe pain (VAS> or = 7). As the pain scores were not normally distributed we not used mean and SD of VAS. The number of rescues and complications were also evaluated.

Results: There was not differences in median age (group 1 50’85 sd 15’4; group 2 52’44 sd 15’4 p=0’47), ASA (group 1 1’89 sd 0’75; group 2 1’90 sd 0’57 p=0’88) or diagnosis between two groups. There were differences in percentages of sexes, group 1 with 40% of women and 62’69% in group 2 (p=0’013). There were not differences in incidence of patients with moderate-severe pain (group 1 15/80; group 2 30/126. p=0’392) neither in incidence of patients with severe pain (group 1 33/80; group 2 51/126. p=0’912). There were not differences in number of rescues (p=0’912) neither in number of complications between groups. Global incidence of VAS > 3 were 40’8 but the incidence of rescues were 25’2%

Conclusions: Our findings suggest that both techniques have similar effectiveness, although the global incidence of severe pain was not optimal (21’8%). It is important to remark the different between incidence of patients with VAS > 3 and number of rescues administrated.

Purpose: The identification of anatomical landmarks is an important aspect of joint surgery, to ensure proper placement and alignment for implants and other reconstructive procedures. At the elbow, the center of the capitellum (derived via a digitization of the surface and subsequent sphere fitting) has been well established as a key landmark to identify the axis of rotation of the joint. For some cases, and in particular minimally invasive surgery, only small regions of the capitellum may be exposed which may lead to errors in determining the centre. The purpose of this study was to identify the optimal location of digitizations of the capitellum.

Method: Twenty-five fresh frozen cadaveric distal humeri (19 left, 6 right) were studied. Using an x-ray computed tomography scanner, volumetric images of each specimen were acquired and used to reconstruct a 3-dimensional digital model of the specimen using the Visualization Toolkit (VTK). A sphere-fit algorithm was used to determine the centre of the spherical capitellum based on manually chosen (digitized) points across the 3D capitellar surface. The true geometric centre was located by digitizing points across the entire capitellar surface. Three sub-regions of the capitellum, commensurate with typical surgical approaches with minimal dissection, were then digitized. These were superior anterior lateral (SAL), inferior anterior lateral (IAL) and a combination of these two regions. These regions were compared to the true center using a 1-way Repeated Measures ANOVA with significance set to p = 0.05.

Results: Digitizations of only SAL and IAL sub-regions resulted in the largest differences relative to the true centre: SAL = 3.9±3.4 mm, IAL = 4.2±3.4 mm, (p < 0.0005). There was no difference between SAL and IAL (p = 1.0). Digitization of the combined SAL + IAL regions, while significantly different from the entire capitellum, resulted in the smallest mean difference of 0.87±0.84 mm.

Conclusion: These data show that the region of digitization affects the accuracy of predicting the capitellum centre. In a previous study by our group, we showed that an accurate determination of the centre of a sphere can be achieved with a small surface area of digitization. In the current study, the large errors that occurred when a small surface was digitized (i.e. SAL and IAL alone), are in all likelihood, due the non-spherical nature of the capitellum. In summary, while the most precise method in locating the true centre is to digitize the entire capitellar surface where possible, an alternative approach is to digitize both the superior and inferior anterior lateral regions.

The purpose of the study was to establish if there is a consensus amongst knee surgeons in U.K. related to rehabilitation protocols following microfracture/drilling procedure performed for treatment of full thickness chondral lesions of the knee. Successful rehabilitation is accepted to be essential for achievement of best results.

A questionnaire was produced including questions about use of a CPM machine, use of a brace, weight-bearing status, use of an exercise bike, time allowed for patient to resume running, time allowed for patient to return to contact sports and surgeon’s expectancy of when symptoms will plateau. A simple scenario was put at the beginning of the questionnaire: “ A 23 year-old rugby player sustained a full thickness 1.5 x 1.5 cm chondral fracture on

the medial femoral condyle and

The lesion is treated using microfracture or a standard debridement method – post-operatively how is the patient managed?”. Questions were asked with regard to each site. The questionnaire was sent to BASK members. One hundred and twenty surgeons replied.

Analysis of responses showed an unexpected variability regarding the rehabilitation for patients having treatment for a full thickness chondral lesion, with no common agreement (less than 50%) even about such aspects as the use of CPM, allowed range of motion, weight bearing status or return to sport.

There is a marked disparity amongst knee surgeons in UK regarding the protocol of rehabilitation after treatment for full thickness chondral lesions of the knee. The majority of patients suitable for microfracture are young and active and a successful rehabilitation program is crucial to optimize the results of surgery. There is a need for development of accepted practice guidelines, to standardise the outcome for these patients.

Purpose: The purpose of this study was to determine how patients with soft tissue sarcoma are followed up in the United Kingdom to inform the development of a prospective clinical trial.

Methods: A list of clinicians (surgeons and oncologists) treating patients with soft tissue sarcomas in the United Kingdom was compiled and a postal survey performed. Reminders were sent to non-responders. The survey included questions about the specialty of the clinician, the grade, membership of specialist societies, perceptions about risk factors for recurrence and the value of follow up and asked specifically about three clinical scenarios.

Results: Of 192 clinicians who were sent the questionnaire, responses were obtained from 155 (81%). 128 of these met the criteria for analysis. In the given clinical scenarios, length of follow up varied from 1 year to lifelong. The total number of clinic visits in 5 years varied from 5 to 30, of chest radiographs from 0 to 24, of chest CT scans from 0 to 10, and of local site imaging from 0 to 13. 88 (84%) agreed that follow up is of benefit. 57 (59%) agreed that it would be reasonable to follow up selected patients in the community. 96 (93%) agreed that a study of follow up protocols would be of value.

Discussion: There is significant variation in follow-up protocols amongst clinicians in the United Kingdom. A prospective study of follow-up protocols is likely to be supported.

Aims: To compare two protocols of early mobilisation for minimally displaced radial head fractures through a single-blinded, prospective randomised trial. Methods: Sixty patients were randomly allocated to either immediate active mobilisation or 5-day delay before active mobilisation was commenced. Patients were reviewed at 7 days, 4 weeks and 3 months after injuries. A blinded observer assessed each patient. Results: All fractures united by the third month. At the end of 7days, the mobilisation group had less pain (VAS 6 vs 7.6, p=0.002); greater ßexion (mean 112û vs 98û, p=0.0004); greater strength in supination (p< 0.001) and better elbow function (Morrey Score 54 vs 43, p=0.005). By the fourth week, both groups were comparable in all parameters and improvement continued into the third month. Mean limit of extension at the third month were 2.3û in the immediate mobilisation group and 1.8û in the delayed group (NS). All had excellent function on the basis of the Morrey Score. Conclusions: Immediate mobilisation did not adversely affect the outcome; the patients had less pain and better elbow function at one week post-injury. Pain, ranges of movement and function were similar by the fourth week post-injury.

Purpose: The aim of this study was to follow a prospective cohort of young subjects with total hip arthroplasties (THA) in order to determine 1) how they complied with instructions concerning the surveillance of their implant, and 2) determine factors affecting non-compliance and the potential consequences in terms of wear.

Material and methods: We implanted fifty Harris I cups with the ABG I stem in 15 young men and 24 young women (11 bilateral implantations) between 1991 and 1995. These patients were a non-consecutive prospective series of patients under 60 years of age (mean age at implantation was 38 ± 11 years, range 15–58 years). The ABG I stem was implanted when the femoral canal was cylindrical, other implants were chosen for other morphologies. 28-mm femoral heads were used in 38 cases (30 zircone, 8 chromium-cobalt, polyethylene thickness 8.6 mm, range 8.3–12.4). The patients were informed of the need for regular surveillance with controls at two months, and one year and then every two years. We re-evaluated all the patients again in 2000. Radiographic wear was assessed according to Livermore using a numeric table (OrthoGraphics).

Results: At mean follow-up of 72 ± 14 months (5–9 years), 20 of the 39 patients (25/50 implants) had not attended the intermediary consultations, but all were seen again for the systematic review made in 2000. There was no particular factor related to non-attendance other than male gender (p = 0.04). Wear was rather severe. Mean values were: linear wear 1.32 mm, 0.23 mm/an. Thirty-seven percent of the patients who had severe annual linear wear (> 0.2 mm) had not attended consultations, all were asymptomatic. The 28 mm head produced more volumetric wear than the 22 mm heads (p = 0.008). There was no other factor correlated with severity of wear (age, sex, activity, polyethylene thickness). This systematic revision led to: three replacements due to excessive wear > 2 mm and replacements planned for three others with > 2 mm wear. These six patients were asymptomatic and three of the six had never attended the planned visits.

Conclusion: Despite our recommendations, half of the patients did not comply with the planned surveillance protocol. Non-compliance being inevitable, we recommend regular systematic recalls to detect severe wear early, even in asymptomatic patients. In addition, our study demonstrated that zircone heads contribute little and confirmed the interest of 22 mm heads to limit wear phenomena.

Over the past 30 years there have been many improvements in implant fixation, correction of deformity, improved polyethylene wear, and survival after knee replacement. The work over the last decade has focused on less invasive surgical techniques, multimodal pain management protocols, more rapid functional recovery and reduced length of stay, aiming to minimise the side effects of treatment while maintaining function and implant durability. When combined and standardised these pre-, intra- and post-operative factors have now facilitated outpatient knee replacement procedures for unicompartmental replacement, patella femoral arthroplasty and total knee replacement (TKR).

We have found liposomal bupivacaine, with potential for longer therapeutic action, to be a helpful adjunct and describe our current pain management program. The next step in our multimodal program is to improve the duration of patient satisfaction and reduce cost and length of stay after TKR.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):7–9.

The development of local recurrence after multimodal treatment of osteosarcoma is associated with a very poor prognosis. The importance of clear surgical margins has been demonstrated in multiple studies, however up to date there are no studies defining which margin width is safe from an oncological perspective. The purpose of this retrospective analysis was to evaluate whether margin width or other surgical and tumour-related factors influence the development of local recurrence in osteosarcoma patients.

The files of 1867 consecutive patients with high-grade central osteosarcoma of the extremities, the pelvic bones and the shoulder girdle, who had achieved a complete surgical remission during combined-modality therapy on neoadjuvant Cooperative Osteosarcoma Study Group (COSS) protocols between 1986 and 2005, were reviewed. Of those, the data required were available for 1369 patients, who were the subject of this analysis. Eighty of these patients developed a local recurrence during the course of their illness.

The median surgical margin width amounted to 45 mm (range, 0 to 140 mm) in the local recurrence (LR) group and 50 mm (range, 0 to 350 mm) in the non-local recurrence (NLR) group (p=0.106). No statistically significant difference between the two groups was found regarding tumour size (mean, 10.38 cm and 9.53 cm respectively, p=0.169), T-status (p=0.225) and presence of pathological fracture (p=0.231). However infiltration of the soft tissue beyond the periosteum was documented in 58.8% of the patients with local recurrence and only in 36.9% of the rest (p=0.003). Furthermore, in 50% of the LR group the biopsy had been performed in a centre other than the one performing the definitive tumour resection, compared to 30.2% of the NRL group (p=0.001).

In conclusion, the absolute metric width of surgical margins does not define oncological safety. Local recurrence is more likely to develop in patients with soft tissue infiltration beyond the periosteum or those biopsied in a centre other than the one performing the tumour resection.