Aims. The aticularis genu (AG) is the least substantial and deepest muscle of the anterior compartment of the thigh and of uncertain significance. The aim of the study was to describe the anatomy of AG in cadaveric specimens, to characterize the relevance of AG in pathological distal femur specimens, and to correlate the anatomy and pathology with preoperative magnetic resonance imaging (MRI) of AG. Methods. In 24 cadaveric specimens, AG was identified, photographed, measured, and dissected including neurovascular supply. In all, 35 resected distal femur specimens were examined. AG was photographed and measured and its utility as a surgical margin examined. Preoperative MRIs of these cases were retrospectively analyzed and assessed and its utility assessed as an anterior soft tissue margin in surgery. In all cadaveric specimens, AG was identified as a substantial structure, deep and separate to vastus itermedius (VI) and separated by a clear fascial plane with a discrete neurovascular supply. Mean length of AG was 16.1 cm ( ± 1.6 cm) origin anterior aspect distal third femur and insertion into suprapatellar bursa. In 32 of 35 pathological specimens, AG was identified (mean length 12.8 cm ( ± 0.6 cm)). Where AG was used as anterior cover in pathological specimens all surgical margins were clear of disease. Of these cases, preoperative MRI identified AG in 34 of 35 cases (mean length 8.8 cm ( ± 0.4 cm)). Results. AG was best visualized with T1-weighted axial images providing sufficient cover in 25 cases confirmed by pathological findings.These results demonstrate AG as a discrete and substantial muscle of the anterior compartment of the thigh, deep to VI and useful in providing anterior soft tissue margin in distal femoral resection in bone tumours. Conclusion. Preoperative assessment of cover by AG may be useful in predicting cases where AG can be dissected, sparing the remaining quadriceps muscle, and therefore function. Cite this article: Bone Joint Open 2020;1-9:585–593

Dermatofibrosarcoma protuberans (DFSP) is a rare, monoclonal dermal neoplasm. DFSP is known to be locally aggressive and infiltrative, but with a very low systemic recurrence risk. It is reported to be associated with high local recurrence rates following surgical excision. Positive or marginal resection margins can lead to a high risk of local recurrence. The objective was to determine the oncologic outcome for DFSP treated at our institution. We reviewed our prospectively collected database for all DFSP treated at our unit between 1990 and 2016. Patients were included whether or not they had excision prior to referral (“whoops” procedure). Those with fibrosarcomatous degeneration at presentation to our unit or less than 1 year of follow-up were excluded. The goal of surgery was a negative margin with a minimum margin of 2 cm where possible. Patients were followed up after surgery to monitor complications, recurrence, transformation and/or metastasis. 139 patients with a mean age of 42.7 (SD=14.1) were included. Mean follow-up was 56 months.101 patients had prior “whoops” surgery before referral. 14 patients were also treated with radiotherapy (13 preoperatively, 1 postoperatively). Following surgery, 6 patients had positive margins, 4 underwent radiation treatment while the other 2 had no further treatment. One patient who presented to our unit with a local recurrence developed a further local recurrence, which demonstrated fibrosarcomatous degeneration at the time of resection (1/139, 0.7%). 1 other patient developed a lesion at another site. The recurrence rate in our DFSP cohort is significantly lower than previous reports. Wide margin resection following oncologic principles can result in a very low recurrence rate. After the initial recovery phase, these patients do not require ongoing, frequent follow-up. Future studies should look at if closer margins can also produce similar treatment outcome

INTRODUCTION. Bone tumour resection and subsequent reconstruction remains challenging for the surgeon. Obtaining adequate margins is mandatory to decrease the risk of local recurrence. Improving surgical margins quality without excessive resection, reducing surgical time and increasing the quality of the reconstruction are the main goals of today's research in bone tumour surgical management. With the outstanding improvements in imaging and computerised planning, it is now a standard. However, surgical accuracy is essential in orthopaedic oncologic surgery (Grimmer 2005). Patient specific instruments (PSI) may greatly improve the surgeon's ability to achieve the targeted resection. Thanks to its physical support, PSI can physically guide the blade yielding to a better control over the cutting process (Wong, 2014). Surgical time might significantly be reduced as well when compared to conventional method or navigated procedure. Finally, reconstruction may gain in rapidity and quality especially when allograft is the preferred solution as PSI can be designed as well for allograft cutting (Bellanova, 2013). Since 2011, PSI have systematically been used in our institution for bone tumour resection and when applicable allograft reconstruction. This paper reports the mid- to long-term medical outcomes on a large series. MATERIALS AND METHODS. Between 2011 and 2016, we systematically used PSI to remove bone tumours in 30 patients. The pre-operative planning involved the tumour delineation drawn on MRI by the surgeon. The MRI and obtained tumour volume were transferred to the CT-scan by image fusion (co- registration). Cutting planes were positioned around the tumour including a safe margin. The PSI were designed to ensure a sufficient stability but kept thin enough to limit the bone exposure. The PSI was manufactured by 3D-printing in a biocompatible and sterilisable material. PSI has been intraoperatively to cut the bone with predetermined margins. Medical files were reviewed for large data collection: type, size and site of the tumour, pre-and post-operative metastatic status, bone and soft tissues resection margins, local recurrence, use of an allograft and a PSI for graft adjustment or not for the reconstruction, the fusion of the allograft when applicable, the follow-up time and early/late complications. RESULTS. Over a period of 5 years, 30 patients were operated on with PSI (10 osteosarcomas, 4 chondrosarcomas, 10 Ewing sarcomas and 6 other types of bone tumours). Mean follow-up was 27±20 months. 18 cases out of 30 have more than 2 years follow-up and 13 out of 30 have more than 3 years of follow-up. Mean operating time was 6h02±3h44. Mean size of the tumours was 8,4±4,7cm and location was the upper limb in 5 cases, inferior limb in 15 cases and the pelvis in 10 occurrences. Metastatic disease developed postoperatively in 5 patients. Surgical margins in the bone were R0 in all cases but one case where a R1 surgery was planned to preserve a nerve root. We did not observe any local recurrence in the bone. Within soft tissues, margins were classified as R0 in 28 patients and R1 in 2 patients. In 26 cases, an allograft was used to reconstruct the bone defect. In 23 of those patients, the allograft was selected by CT scan and cut using a PSI. In the 3 allografts cut free-handily, only one demonstrated a fusion. Of the 23 cut with a guide, 12 fused completely, 2 demonstrated a partial fusion and 9 were not fused at the last follow-up. At the last follow-up, 2 patients were dead of disease, 5 were alive with metastatic disease and 23 were alive without disease. DISCUSSION. Oncology is probably the field where PSI can bring the largest advantage when compared to the conventional procedure. Several papers have reported the use of PSI for bone tumour resection. All of them have shown very promising results on in-vitro experiments (Cartiaux 2014), cadaver experiment (Wong 2012) or small clinical series (Bellanova 2013, Gouin, 2014). None of these papers report a large patient series associated with a clinically relevant follow-up. This series is the first mid- to long-term follow-up series involving PSI tumour surgery. These results are showing strong evidences of clinical improvements. It comes into contradiction with PSI for total knee arthroplasty where controversial results on the patient's outcome has been reported (Thienpont 2014). R0 margin has been systematically obtained for all bone cuttings, and local recurrence has been strongly decreased (3%) when compared to the usual recurrence rates published in the literature (from 15% to 35% according to the location). Allograft fusion seems improved as well thanks to the shape-matching of the selected allograft and a close contact between host and allograft at bony junctions. With a longer follow-up, these evidences should be stronger to definitely make PSI the best option for bone tumour resection

Introduction. Malalignment of cup in total hip replacement (THR) increases rates of dislocation, impingement, acetabular migration, pelvic osteolysis, leg length discrepancy and polyethylene wear. Many surgeons orientate the cup in the same anteversion and inclination as the inherent anatomy of the acetabulum. The transverse acetabular ligament (TAL) and acetabular rim can be used as a reference. No study has yet defined the exact orientation of the TAL. The aim of this study was to describe the orientation of acetabular margin and compare it with TAL orientation. Materials and Methods. Sixty eight hips with osteoarthritis undergoing THR with computer navigation were investigated. Anterior pelvic plane was registered using anterior superior iliac spines and pubic symphysis. Orientation of the natural acetabulum as defined by the acetabular rim with any osteophytes excised was measured. Since TAL is a rectangular band like structure, three recordings were done for each corresponding to the outer middle and inner margin of the band. All the readings were given by software as radiological anteversion and inclination. Results. All patients were Caucasian, 30 males and 38 females with mean age 67.4 years (SD 9.6) and BMI 30 (SD 5). Inclination was 54.7(SD7.9), 53(SD6.9), 47.5(SD6.8), 42.1(6.7) and anteversion 5.7(SD8.7), 5.4(SD9.9), 9.7(SD9.6), 13.5(SD9.4) for acetabular rim, outer, middle and inner borders of the TAL respectively. For inclination TAL outer border was not significantly different to acetabular rim (mean difference 1.7°, 95%CIs −0.2° to 3.6°, p=0.082) but the middle (mean difference 7.3°, 95%CIs 5.6° to 8.9°) and inner (mean difference 12.6°, 95%CIs 11.0° to 14.2°) borders were (both p<0.001). For anteversion TAL outer border was not significantly different to acetabular rim (mean difference 0.2°, 95%CIs −1.3° to 1.8°, p=0.758) but the middle and inner borders were (mean difference −4.0° 95%CIs −5.5° to −2.5° and −7.9°, 95%CIs −9.6° to −6.1° respectively, both p<0.001). Anteversion for males was significantly lower than females with a mean difference of 4 for the rim and 5.7, 4.8 and 5.1 for the TAL outer, middle and inner margins respectively. Overall 57,53,40&26 of 68 patients had a combined inclination and anteversion of the native acetabulum that fell outside the “safe zone” of Lewinnek with acetabular rim, outer, middle and inner margins of TAL respectively. Compared to Lewinnek safe zones for inclination TAL inner margin performed best with 14.7% outliers and acetabular rim performed worst with 72% outliers. For anteversion TAL inner margin performed best with 25% outliers while outer margin of TAL performed worst with 39.7% outliers. Conclusion. Orientation of the acetabulum differs a lot between individuals. The TAL middle and inner margins differ in orientation as compared to acetabular rim and TAL outer border. TAL inner border provides the best bet for placing the cup in Lewinnek's safe zone. When using the natural acetabular orientation or TAL as a guide, it should not be assumed this will orientate the cup in Lewinnek safe zone although the validity of safe zones itself is questionable. Variation between patients must be taken into account and the difference between males and females, particularly in terms of anteversion, should be considered

Abstract

Traditional staging systems for high grade osteosarcoma (Enneking, MSTS) are based largely on gross surgical margins and were developed before the widespread use of neoadjuvant chemotherapy. It is now well known that both microscopic margins and chemotherapy are predictors of local recurrence. However, neither of these variables are used in the traditional surgical staging and the precise safe margin distance is debated. Recently, a novel staging system utilizing a 2mm margin cutoff and incorporating precent necrosis was proposed and demonstrated improved prognostic value for local recurrence free survival (LRFS) when compared to the MSTS staging system. This staging system has not been validated beyond the original patient cohort. We propose to analyze this staging system in a cohort of patients with high-grade osteosarcoma, as well as evaluate the ability of additional variables to predict the risk of local recurrence and overall survival. A retrospective review of a prospectively collected database of all sarcoma patients between 1985 and 2020 at a tertiary sarcoma care center was performed. All patients with high-grade osteosarcoma receiving neo-adjuvant chemotherapy and with no evidence of metastatic disease on presentation were isolated and analyzed. A minimum of two year follow up was used for surviving patients. A total of 225 patients were identified meeting these criteria. Univariate analysis was performed to evaluate variable that were associated with LRFS. Multivariate analysis is used to further analyze factors associated with LRFS on univariate analysis. There were 20 patients (8.9%) who had locally recurrent disease. Five-year LRFS was significantly different for patients with surgical margins 2mm or less (77.6% v. 93.3%; p=0.006) and those with a central tumor location (67.9 v. 94.4; <0.001). A four-tiered staging system using 2mm surgical margins and a percent necrosis of 90% of greater was also a significant predictor of 5-year LRFS (p=0.019) in this cohort. Notably, percent necrosis in isolation was not a predictor of LRFS in this cohort (p=0.875). Tumor size, gender, and type of surgery (amputation v. limb salvage) were also analyzed and not associated with LRFS. The MSTS surgical margin staging system did not significantly stratify groups (0.066). A 2mm surgical margin cutoff was predictive of 5-year LRFS in this cohort of patients with localized high-grade osteosarcoma and a combination of a 2mm margin and percent necrosis outperformed the prognostic value of the traditional MSTS staging system. Utilization of this system may improve the ability of surgeons to stage thier patients. Additional variables may increase the value of this system and further validation is required

Introduction. Derotation osteotomies are commonly performed in paediatric orthopaedic and limb reconstruction practice. The purpose of this study was to determine whether the use of a digital inclinometer significantly improves the accuracy in attaining the desired correction. Materials & Methods. We designed an electronic survey regarding derotation femoral osteotomy (DFO) including methods of intra-operative angular correction assessment and acceptable margins of error for correction. This was distributed to 28 paediatric orthopaedic surgeons in our region. A DFO model was created, using an anatomic sawbone with foam covering. 8 orthopaedic surgeons each performed two 30-degree DFOs, one using K-wires and visual estimation (VE), and the other using a Digital Inclinometer (DI). Two radiologists reported pre and post procedure rotational profile CT scans to assess the achieved rotational correction. Results. There was a 68% response rate to the survey. The most popular methods of estimating intra-operative correction were reported to be K-wires and rotation marks on bone. The majority of respondents reported that a 6–10 degree margin of error was acceptable for a 30-degree derotation. This was therefore set as the upper limit for acceptable error margin in the simulation study. The mean error in rotation in the VE group of simulated DFO was 19.7 degrees, with error>5 degrees and error>10 degrees in 7 (88%) and 6 (75%) cases respectively. Mean error in DI group was 3.1 degrees, with error>5 degrees in 1 case (13%). Conclusions. Our results show that the compared to conventional techniques, the use of an inclinometer significantly improves the accuracy of femoral de-rotation and significantly reduces the incidence of unacceptable errors in correction. We would suggest that digital inclinometers be used to assess intra-operative correction during derotation osteotomies

Abstract. Background. Conventional periacetabular pelvic resections are associated with poor functional outcomes. Resections through surgical corridors beyond the conventional margins may be helpful in retaining greater function without compromising the oncological margins. Methods. The study included a retrospective review of 82 cases of pelvic resections for pelvic tumors. Outcomes of acetabulum preservation (Group A) were compared with complete acetabular resection (Group B). Also, we compared outcomes of Type I+half resections (Group 1) with Type I+II resections (Group 2), and Type III+half resections (Group 3) with Type II+III resections (Group 4). Results. Group A (n=44) had significantly better functional outcome than Group B(n=38) with average MSTS93 score 22.3 vs 20.1 and average HHS 91.3 vs 82.5 (p<0.001). Group 1(n=14) and Group 2(n=12) had similar functional outcomes (mean MSTS93 score 22.07 vs 21.58 (p=0.597) and mean HHS 90.37 vs 86.51 (p=0.205)). Group 3(n=11) had significantly better functional outcome than Group 4(n=17), with mean MSTS93 score 22.8 vs 19.7 (p<0.001) and mean HHS 92.3 vs 80.1 (p<0.001). Oncological outcomes were similar among the groups. Conclusion. Trans-acetabular pelvic resections provide functional benefit over conventional resections without compromising oncological margins. There is a need to revisit and revise the pelvic resection planes

This study aimed to describe the morphology of the coracoid process and determine the frequency of commonly observed patterns. The second purpose was to determine the location of inferior tunnel exit with superior based tunnel drilling and the superior tunnel exit with inferior based tunnel drilling. A sample of 100 dry scapulae for the morphology aspect and 52 cadaveric embalmed shoulders for tunnel drilling were used. The coracoid process was described qualitatively and categorized into 6 different shapes. A transcoracoid tunnel was drilled at the centre of the base. Twenty-six shoulders were used for the superior-inferior tunnel drilling approach and 26 for the inferior-superior tunnel drilling approach. The distances to the margins of the coracoid process, from both the entry and exit points of the tunnel, were measured. Eight coracoid processes were of convex shape, 31 of hooked shape, 18 of irregular shape, 18 of narrow shape, 25 of straight shape, and 13 of wide shape. The mean difference for the distances between superior entry and inferior exit from the apex was Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation 3.65+3.51mm (p=0.002); 1.57+2.27mm for the lateral border (p=0.40) and 5.53+3.45mm for the medial border (p=0.001). The mean difference for the distances between inferior entry and superior exit from the apex was 16.95+3.11mm (p=0.0001); 6.51+3.2mm for the lateral border (p=0.40) and 1.03+2.32 mm for the medial border (p=0.045). The most common coracoid process shape observed was a hooked pattern. Both superior to inferior and inferior to superior tunnel drilling directed the tunnel from a more anterior and medial entry to a posterior-lateral exit. Superior to inferior drilling resulted in a more posteriorly angled tunnel. With inferior to superior tunnel drilling cortical breaks were observed at the inferior and medial margin of the tunnel

Myxoid or Myxoid Round Cell liposarcoma (MLS) is a mesenchymal malignancy with adipocyte differentiation accounting for 15–20% of liposarcomas and 5% of all adult soft tissue sarcomas (STS). Like other STS, treatment of MLS is generally by wide surgical resection in conjunction with radiotherapy and this approach is associated with low rates of local recurrence [1]. However, most MLS are located between muscles so wide local excision(WLE) can be quite morbid with adverse functional results. MLS are known to be extremely sensitive to radiotherapy which has led to development of treatment protocols utilizing neoadjuvant radiation. Given the radiosensitivity of MLS, we hypothesize that resection with marginal margins (1mm) does not result in higher rates of local recurrence or disease-free survival if performed following pre-operative radiotherapy. We identified all patients with localized MLS who underwent preoperative radiation and surgical resection between January 2000 and January 2018 from a prospectively collected sarcoma database. We calculated the ellipsoid tumour volume(ETV=h x w x d x ()) at diagnosis and after radiation, and documented the necrosis percentage of the tumour and margin status following resection based on histological analysis [2]. Marginal resection was identified by the operative report describing no or only very minimal resection of muscle surrounding the tumour, and a negative surgical margin 0.1cm/1mm as defined histologically. In comparison, WLE was defined if the operative note described an attempt to remove the tumour with a cuff of surrounding muscle, and the final histology reported a negative margin 0.1cm/1mm which included skeletal muscle. The third group for analysis included patients with positive resection margins. There were 91 patients with MLS of mean age 48 years (range 18–88) with 69% male and 31% female. The mean pre-radiotherapy ETV was 507cm. 3. (16.1cm. 3. to 6961cm. 3. ) and decreased to 361cm. 3. (8.7cm. 3. to 5695cm. 3. ) following radiation, with an average percentage reduction in ETV of −45%(+129%to-99%). Mean patient follow-up was 7.3 years (0.2–18) with no differences between margin groups(p=0.284). Only 10(11%) patients had positive margins, of which 43(47%) underwent marginal resection and 38(42%) WLE. Overall the mean necrosis as measured histologically following preoperative radiation was 69% (range 0–100%) with no differences between the 3 resection groups(p-0.151). Similarly, there was no significant difference in reduction in mean ETV between the three resection groups(p=0.311), there was no significant difference between the three treatment groups in 5-year LR-free survival (p=0.469), metastasis-free survival (p=0.841) or overall survival (p=0.873). Most patients with MLS experienced significant reduction in tumour size and necrosis following preoperative radiation. We found no differences in the risk of local recurrence or survival based on the type of surgical approach for patients with MLS. Based on these results, we conclude that MLS can be safely removed by marginal resection following preoperative radiotherapy with high rates of local tumour control. Even following a positive margin resection, local recurrence remains uncommon after preoperative radiation. A marginal surgical approach for patients with MLS reduces the need for major muscle resection and is associated with improved functional outcomes with less complications

Background and aim. In 2019, specific diagnostic and antibiotic treatment recommendations for diabetic foot infection (DFI) and osteomyelitis (DFO) were introduced in our institution. They include principles on numbers of biopsies to obtain for microbiological/histopathological examinations, labeling anatomic localization, and antibiotic treatment (ABT) duration based on the aforementioned findings. ABT should be stopped after complete resection of infected bone. In case of incomplete resection, treatment is continued for 4–6 weeks. Two years after the introduction of these recommendations, we investigated the degree of implementation for hospitalized patients. Method. Adult patients with DFI/DFO undergoing surgical intervention from 01/2019–12/2021 were reviewed retrospectively. Diagnostic procedures were assigned to each episode when performed ≤30 days before surgical invention. Chi-square and Mann-Whitney-U tests were performed where appropriate. Results. We included 80 patients with 117 hospital episodes and 163 surgical interventions (mean 1.5 episodes and 2 interventions per patient). The mean age was 69.6 (SD 11.5) years, 75% were male. Vascular examination and MRI were performed in 70.9% and 74.4% of episodes, respectively. Impaired perfusion and DFO were confirmed in 34.9% and 56.3%, respectively. Blood cultures were sampled in 34.2%, bacteremia detected in 7.7% with S. aureus being the most common microorganism. Biopsies were obtained in 71.8% of operations, in 90.5% of those 3–5 samples. These were sent for histological examination in 63.2% of the interventions. In 43.6% the anatomic location was labeled ‘proximal to the resection margin’. Preoperative antibiotics were administered in 41.9% of the episodes because of concomitant soft-tissue infections. The most commonly used compound was amoxicillin/clavulanate (74.4%). ABT duration varied significantly when there were signs of DFO in preoperative MRI (p=0.015). The mean duration of antibiotic therapy was 9 (IQR 5–15) days in surgically cured episodes and 40.5 (IQR 15–42) days in cases with resection margins in non-healthy bone (p<0.0001). The results were similar when analyzing treatment duration with respect to osteomyelitis in histology: 13 (IQR 8–42) versus 29 (IQR 13–42) days, respectively (p=0.026). Conclusions. The adherence to recommendations in terms of biopsy sampling was excellent, moderate for sending samples to histology and poor for labeling the anatomic location. The adherence to ABT duration was good but can be improved by shortening treatment duration for surgically cured cases. Results of preoperative MRI appear to be influential on the decision-making for treatment duration

The Australia and New Zealand Sarcoma Association established the Sarcoma Guidelines Working Party to develop national guidelines for the management of Sarcoma. We asked whether surgery at a specialised centre improves outcomes. A systematic review was performed of all available evidence pertaining to paediatric or adult patients treated for bone or soft tissue sarcoma at a specialised centre compared with non-specialised centres. Outcomes assessed included local control, limb salvage rate, 30-day and 90-day surgical mortality, and overall survival. Definitive surgical management at a specialised sarcoma centre improves local control as defined by margin negative surgery, local or locoregional recurrence, and local recurrence free survival. Limb conservation rates are higher at specialised centres, due in part to the depth of surgical experience and immediate availability of multidisciplinary and multimodal therapy. A statistically significant correlation did not exist for 30-day and 90-day mortality between specialised centres and non-specialised centres. The literature is consistent with improved survival when definitive surgical treatment is performed at a specialised sarcoma centre. Evidence-based recommendation: Patients with suspected sarcoma to be referred to a specialised sarcoma centre for surgical management to reduce the risk of local recurrence, surgical complication, and to improve limb conservation and survival. Practice point: Patients with suspected sarcoma should be referred to a specialised sarcoma centre early for management including planned biopsy

Objectives. We identified an unusual pattern of backside deformation on polyethylene (PE) inserts of contemporary total knee replacements (TKRs). The PE backside's margins were inferiorly deformed in TKRs with NexGen central-locking trays. This backside deformation was significantly associated with tray debonding. Furthermore, recent studies have shown high rate of tray debonding in PS NexGen TKRs. Subsequently, a field safety notice was issued regarding the performance of this particular device combination and the Option tray has been withdrawn from use. Therefore, we hypothesised that the backside deformation of PS inserts may be greater than that of CR inserts. Design and Methods. At our national implant retrieval centre, we used peer-reviewed techniques to analyse changes in the bearing wear rate and backside surface deformation of NexGen PE inserts using coordinate measuring machines [N=84 (CR-43 and PS-41) TKRs with non-augmented-trays]. Multiple regression was used to determine which variable had the greatest influence on backside deformation. The amount of cement cover on trays was quantified as a %of the total surface using Image-J software. Results. The median (IQR) bearing wear rate of the PS PEs [14(8-22) mm. 3. /year] was not significantly different(p=0.154) to that of the CR PEs [18(8-27)mm. 3. /year]. The median (IQR) backside deformation of the PS inserts [294(239-361) µm] was significantly greater (p<0.001) than that of the CR inserts [212(158-258)µm]. Multiple regression modelling showed that duration in-vivo (p=0.037), central-clearance between insert and tray (p<0.001) and constraint (p=0.003) were significantly associated with PE backside-deformation. 38(93%) PS and 31(72%) of CR trays exhibited ≤10% of cement cover. Non-contacting profilometry and microscopy revealed marked pitting and abrasive changes to the superior surface of the tray. Conclusion. This explant study showed the PE backside deformation was significantly higher in PS than in CR inserts and this may be one explanation for the unsatisfactory clinical performance reported with this device combination

Aim. The current recommendation in Norway is to use four doses of a first-generation cephalosporin (cefazolin or cephalotin) as systemic antibiotic prophylaxis (SAP) the day of surgery in primary joint arthroplasty. Due to shortage of supply, scientific development, changed courses of treatment and improved antibiotic stewardship, this recommendation has been disputed. We therefore wanted to assess if one dose of SAP was non-inferior to four doses in preventing periprosthetic joint infection (PJI) in primary joint arthroplasty. Method. We included patients with primary hip- and knee arthroplasties from the Norwegian Arthroplasty Register and the Norwegian Hip Fracture Register for the period 2005-2023. We included the most used SAPs (cephalotin, cefazolin, cefuroxime, cloxacillin and clindamycin), administered as the only SAP in 1-4 doses, starting preoperatively. Risk of revision (Hazard rate ratio; HRR) for PJI was estimated by Cox regression analyses with adjustment for sex, age, ASA class, duration of surgery, reason for- and type of arthroplasty, and year of primary arthroplasty. The outcome was 1-year reoperation or revision for PJI. Non-inferiority margins were calculated for 1, 2 and 3 doses versus reference of 4 doses of SAP at the day of surgery, against a predetermined limit of 15% increased risk of PJI. Results. In total 274,188 primary arthroplasties (total hip 133,985, hemi hip 51,442, and total knee 88,761) were included. Of these primary arthroplasties, 2,996 (1.1%) had subsequent revisions for PJI during the first postoperative year. One dose of SAP was given in 9,603 arthroplasties, two doses in 10,068, three doses in 18,351, and four doses in 236,166 arthroplasties. With the recommended four doses as reference, the HRR (95% CI) for 1-year revision for infection was 0.9 (0.7-1.1) for one dose, 1.0 (0.8-1.2) for two doses, and 0.9 (0.8-1.1) for three doses. The corresponding adjusted 1-year revision incidences for PJI was 0.9 (0.7-1.1), 1.0 (0.8-1.2), 0.9 (0. 8-1.1) and 1.0 (1.0-1.1) for one, two, three and four doses respectively, and less than four doses was found to be non-inferior. Conclusions. One preoperative dose of SAP in primary joint arthroplasty surgery seems to be non-inferior to the current recommendation of four doses of a first-generation cephalosporin as PJI-prophylaxis. This finding may simplify the course of treatment for arthroplasty patients, save costs, and improve antibiotic stewardship

Aim. This study seeks to outline the clinical, laboratory, and imaging features of patients with pyogenic spondylitis. It aims to define a novel imaging sign that could indicate the severity of suppurative spondylitis, aiding in its early diagnosis and treatment. Method. This retrospective study included 137 patients from 2013 to 2023. Through the analysis and summary of imaging characteristics among all patients, we identified a distinct MRI sign known as ‘the Disc Penetration sign’ (DP). This sign is defined as an image finding on sagittal MRI depicting the anterior and posterior penetration of an abscess through the intervertebral disc space, affecting both the anterior margin of the vertebrae and the structures within the spinal canal. Observational parameters included WBC, ESR, CRP, hemoglobin, and albumin levels. Documentation of the study included location and segment of the lesion, presence or absence of spinal cord compression, and paravertebral abscesses. Results. 56 patients presented with the Disc Penetration sign(DP) and 81 did not. In both groups, there were no significant differences in gender ratio or age (P > 0.05). However, significant differences were observed in the presence of comorbid diabetes and chronic kidney disease (p < 0.05). The DP group had a significantly greater ESR level (74.30±33.79 mm/h vs. 51.46±30.46 mm/h, P < 0.001) and CRP level (47.28 mg/L vs. 26.18 mg/L, P = 0.003). Additionally, the DP group had a significantly lower Hb (100.66±19.82 g/L vs. 116.99±19.99g/L,P < 0.001) and the serum albumin level (28.81±6.59 g/L vs. 34.09±6.17 g/L,P < 0.001). Imaging results showed no significant differences in affected spinal segments or parts (p>0.05). Patients in the DP group showed a higher likelihood of developing paravertebral abscesses compared to those in the non-DP group (n = 54 [96.4%] vs. n = 33 [40.7%], P < 0.001), and also exhibited a higher incidence of spinal cord compression(n = 32 [57.1%] vs. n = 17 [21.0%], P < 0.001). Conclusions. The study suggests that the Disc Penetration sign in pyogenic spondylitis patients correlates with more severe inflammation and higher incidence of paraspinal abscess, pointing to worse stability of the spine, longer bone restructuring time, and potentially poorer prognosis. These findings enable clinicians to rapidly assess the severity of the disease and prognosticate outcomes more effectively We emphasize the need for early, pathogen-specific diagnosis and treatment, particularly considering surgical intervention for patients demonstrating substantial paraspinal abscesses or spinal instability

Wide resection, with or without adjuvant therapy, is the mainstay of treatment for soft tissue sarcoma of the extremities. The surgical treatment of soft tissue sarcoma can portend a prolonged course of recovery from a functional perspective. However, data to inform the expected course of recovery following sarcoma surgery is lacking. The purpose of this study was to identify time to maximal functional improvement following sarcoma resection and to identify factors that delay the expected course of recovery. A retrospective chart review was performed of all patients undergoing surgical treatment of a soft tissue sarcoma of the extremities between January 1st, 1985 and November 15, 2020 with a minimum of 1 follow up. The primary outcome measure was time to maximal functional improvement, defined as failure to demonstrate improvement on two consecutive follow up appointments, as defined by the functional outcome measures of Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) Score or by achieving 90% of maximum outcome score. We identified 1188 patients who underwent surgical resection of a soft tissue sarcoma of the extremities. Patients typically achieved a return to their baseline level of function by 1 year and achieved “maximal” functional recovery by 2 year's time postoperatively. Patient and tumor factors that were associated with worse functional outcome scores and a delayed return to maximal functional improvement included older age (p=0.007), female sex (p-0.004), larger tumor size (p < 0 .001), deep tumor location (p < 0 .001), pelvic location (p < 0 .001), higher tumor grade (p < 0 .001). Treatment factors that were associated with worse functional outcome scores and a delayed return to maximal functional improvement included use of radiation therapy (p < 0 .001), perioperative complications (p < 0 .001), positive margin status (p < 0 .001) and return of disease, locally or systemically (p < 0 .001). Most patients will recover their baseline function by 1 year and achieve “maximal” recovery by 2 years’ time following surgical resection for soft tissue sarcoma of the extremities. Several patient, tumor and treatment factors should be used to counsel patients as to a delayed course of recovery

Aims. Sickle cell disease (SCD) is an autosomal recessive inherited condition that presents with a number of clinical manifestations that include musculoskeletal manifestations (MM). MM may present differently in different individuals and settings and the predictors are not well known. Herein, we aimed at determining the predictors of MM in patients with SCD at the University Teaching Hospital, Lusaka, Zambia. Methods. An unmatched case-control study was conducted between January and May 2019 in children below the age of 16 years. In all, 57 cases and 114 controls were obtained by systematic sampling method. A structured questionnaire was used to collect data. The different MM were identified, staged, and classified according to the Standard Orthopaedic Classification Systems using radiological and laboratory investigations. The data was entered in Epidata version 3.1 and exported to STATA 15 for analysis. Multiple logistic regression was used to determine predictors and predictive margins were used to determine the probability of MM. Results. The cases were older median age 9.5 (interquartile range (IQR) 7 to 12) years compared to controls 7 (IQR 4 to 11) years; p = 0.003. After multivariate logistic regression, increase in age (adjusted odds ratio (AOR) = 1.2, 95% confidence interval (CI) 1.04 to 1.45; p = 0.043), increase in the frequency of vaso-occlusive crisis (VOC) (AOR = 1.3, 95% CI 1.09 to 1.52; p = 0.009) and increase in percentage of haemoglobin S (HbS) (AOR = 1.18, 95% CI 1.09 to 1.29; p < 0.001) were significant predictors of MM. Predictive margins showed that for a 16-year-old the average probability of having MM would be 51 percentage points higher than that of a two-year-old. Conclusion. Increase in age, frequency of VOC, and an increase in the percentage of HbS were significant predictors of MM. These predictors maybe useful to clinicians in determining children who are at risk. Cite this article: Bone Joint Open 2020;1-6:175–181

Radiation induced sarcoma of bone is a rare but challenging disease process associated with a poor prognosis. To date, series are limited by small patient numbers; data to inform prognosis and the optimal management for these patients is needed. We hypothesized that patients with radiation-induced pelvic bone sarcomas would have worse surgical, oncologic, and functional outcomes than patients diagnosed with primary pelvic bone sarcomas. This was a multi-institution, comparative cohort analysis. A retrospective chart review was performed of all patients diagnosed with a radiation-induced pelvic and sacral bone sarcoma between January 1st, 1985 and January 1st, 2020 (defined as a histologically confirmed bone sarcoma of the pelvis in a previously irradiated field with a minimum 3-year interval between radiation and sarcoma diagnosis). We also identified a comparison group including all patients diagnosed with a primary pelvic osteosarcoma/spindle cell sarcoma of bone (i.e. eligible for osteosarcoma-type chemotherapy) during the same time interval. The primary outcome measure was disease-free and overall survival. We identified 85 patients with primary osteosarcoma of the pelvis (POP) and 39 patients with confirmed radiation induced sarcoma of the bony pelvis (RISB) undergoing surgical resection. Patients with RISB were older than patients with POP (50.5 years vs. 36.5 years, p67.7% of patients with POP underwent limb salvage as compared to 77% of patients with RISB; the type of surgery was not different between groups (p=.0.24). There was no difference in the rate of margin positive surgery for RISB vs. POP (21.1% vs. 14.1%, p=0.16). For patients undergoing surgical resection, the rate of surgical complications was high, with more RISB patients experiencing complications (79.5%) than POP patients (64.7%); this approached statistical significance (p=0.09). 15.4% of patients with RISB died perioperative period (within 90 days of surgery) as compared to 3.5% of patients with POP (p= 0.02). For patients undergoing surgical resection, 5-year OS was significantly worse for patients with RISB vs. POP (27.3% vs. 47.7%, p=0.02). When considering only patients without metastatic disease at presentation, a significant difference in 5-year survival remains for patients with RISB vs. POP (28.6% vs. 50%, p=0.03) was a trend towards poorer 5-year DFS for patients with RISB vs. POP (30% vs. 47.5%), though this did not achieve statistical significance (p=0.09). POP and RISB represent challenging disease processes and the oncologic outcomes are similarly poor between the two; however, the disease course for patients with RISB appears to be worse overall. While surgery can result in a favorable outcome for a small subset of patients, surgical treatment is fraught with complications

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor with an intermediate tendency to metastasize, which is found in many different locations including head and neck, abdomen, chest cavity and extremities. Also, meningeal hemangiopericytoma (HPC) is considered an SFT which arises in the meningeal membranes. SFT family shows an undetermined biologic behavior varying from a silent indolent tumor to an aggressive malignant form; however, benign and malignant variants of SFT may have similar cytopathologic characteristics. In this study, we defined the factors correlated with SFT's aggressive behavior and patient's survival. This is a retrospective study based on medical records of 85 patients who were suffering from SFT and had been treated at McGill University Health Centre (MUHC) between 1984 and 2017. We used multivariate logistic regression analysis to address any association between the variables including patient's demographics, tumor size, primary location of the tumor, pathological features, treatment methods and outcomes. The median of the follow-up period was 60 months. The patient's age or gender had no association with tumor aggressive behavior or patient's survival. Anatomical origin of primary tumor had no strong correlation with the patient's disease related death (DRD); however, tumors originated from CNS showed more aggressive behavior. There was an association between tumor size more than 7 cm and distant metastasis (MT) (p= 0.03) and DRD (p=0.03). The tumor size also correlated with the 5-year disease-free survival (p=0.017). We had three histologic groups: 1- Benign SFT (30 cases), 2- cellular SFT or HPC (29 cases), 3- malignant SFT or anaplastic HPC (26 cases). Although univariate analysis demonstrates that patients suffering from cellular SFT and malignant SFT showed increased aggressive behavior of the tumor, multivariate analysis didn't verify the mentioned association. Patients with positive margins had increased odds ratio to experience tumor local recurrence (LR) (p= 0.05) and LR was correlated with DRD in our patients (p=0.006). Radiotherapy had no statistical association with LR, MT or DRD. Frequency of LR and MT in the study were 25.7% and 29.8% respectively. 5-year disease-free survival in our patients was 76%. The size of SFT is the most correlative predictor of the tumor's aggressive behavior. The local recurrence of SFT is associated with disease related death; therefore, resection of the tumor with negative margins provides the highest chance of cure. In addition, a cellular SFT should be treated like a malignant variant of the tumor

Introduction. A significant burden of disease exists with respect to critical sized bone defects; outcomes are unpredictable and often poor. There is no absolute agreement on what constitutes a “critically-sized” bone defect however it is widely considered as one that would not heal spontaneously despite surgical stabilisation, thus requiring re-operation. The aetiology of such defects is varied. High-energy trauma with soft tissue loss and periosteal stripping, bone infection and tumour resection all require extensive debridement and the critical-sized defects generated require careful consideration and strategic management. Current management practice of these defects lacks consensus. Existing literature tells us that tibial defects 25mm or great have a poor natural history; however, there is no universally agreed management strategy and there remains a significant evidence gap. Drawing its origins from musculoskeletal oncology, the Capanna technique describes a hybrid mode of reconstruction. Mass allograft is combined with a vascularised fibula autograft, allowing the patient to benefit from the favourable characteristics of two popular reconstruction techniques. Allograft confers initial mechanical stability with autograft contributing osteogenic, inductive and conductive capacity to encourage union. Secondarily its inherent vascularity affords the construct the ability to withstand deleterious effects of stressors such as infection that may threaten union. The strengths of this hybrid construct we believe can be used within the context of critical-sized bone defects within tibial trauma to the same success as seen within tumour reconstruction. Methodology. Utilising the Capanna technique in trauma requires modification to the original procedure. In tumour surgery pre-operative cross-sectional imaging is a pre-requisite. This allows surgeons to assess margins, plan resections and order allograft to match the defect. In trauma this is not possible. We therefore propose a two-stage approach to address critical-sized tibial defects in open fractures. After initial debridement, external fixation and soft tissue management via a combined orthoplastics approach, CT imaging is performed to assess the defect geometry, with a polymethylmethacrylate (PMMA) spacer placed at index procedure to maintain soft tissue tension, alignment and deliver local antibiotics. Once comfortable that no further debridement is required and the risk of infection is appropriate then 3D printing technology can be used to mill custom jigs. Appropriate tibial allograft is ordered based on CT measurements. A pedicled fibula graft is raised through a lateral approach. The peroneal vessels are mobilised to the tibioperoneal trunk and passed medially into the bone void. The cadaveric bone is prepared using the custom jig on the back table and posterolateral troughs made to allow insertion of the fibula, permitting some hypertrophic expansion. A separate medial incision allows attachment of the custom jig to host tibia allowing for reciprocal cuts to match the allograft. The fibula is implanted into the allograft, ensuring nil tension on the pedicle and, after docking the graft, the hybrid construct is secured with multi-planar locking plates to provide rotational stability. The medial window allows plate placement safely away from the vascular pedicle. Results. We present a 50-year-old healthy male with a Gustilo & Anderson 3B proximal tibial fracture, open posteromedially with associated shear fragment, treated using the Capanna technique. Presenting following a fall climbing additional injuries included a closed ipsilateral calcaneal and medial malleolar fracture, both treated operatively. Our patient underwent reconstruction of his tibia with the above staged technique. Two debridements were carried out due to a 48-hour delay in presentation due to remote geographical location of recovery. Debridements were carried out in accordance with BOAST guidelines; a spanning knee external fixator applied and a small area of skin loss on the proximal medial calf reconstructed with a split thickness skin graft. A revision cement spacer was inserted into the metaphyseal defect measuring 84mm. At definitive surgery the external fixator was removed and graft fixation was extended to include the intra-articular fragments. No intra-operative complications were encountered during surgeries. The patient returned to theatre on day 13 with a medial sided haematoma. 20ml of haemoserous fluid was evacuated, a DAIR procedure performed and antibiotic-loaded bioceramics applied locally. Samples grew Staphylococcus aureus and antibiotic treatment was rationalised to Co-Trimoxazole 960mg BD and Rifampicin 450mg BD. The patient has completed a six-week course of Rifampicin and continues on suppressive Co-Trimoxazole monotherapy until planned metalwork removal. There is no evidence of ongoing active infection and radiological evidence of early union. The patient is independently walking four miles to the gym daily and we believe, thus far, despite accepted complications, we have demonstrated a relative early success. Conclusions. A variety of techniques exist for the management of critical-sized bone defects within the tibia. All of these come with a variety of drawbacks and limitations. Whilst acceptance of a limb length discrepancy is one option, intercalary defects of greater than 5 to 7cm typically require reconstruction. In patients in whom fine wire fixators and distraction osteogenesis are deemed inappropriate, or are unwilling to tolerate the frequent re-operations and potential donor site morbidity of the Masqualet technique, the Capanna technique offers a novel solution. Through using tibial allograft to address the size mismatch between vascularised fibula and tibia, the possible complication of fatigue fracture of an isolated fibula autograft is potentially avoidable in patients who have high functional demands. The Capanna technique has demonstrated satisfactory results within tumour reconstruction. Papers report that by combining the structural strength of allograft with the osteoconductive and osteoinductive properties of a vascularised autograft that limb salvage rates of greater than 80% and union rates of greater than 90% are achievable. If these results can indeed be replicated in the management of critical-sized bone defects in tibial trauma we potentially have a treatment strategy that can excel over the more widely practiced current techniques