Aims. The modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing. Methods. A cohort of 146 distal femur fractures were retrospectively identified at our institution. After excluding AO/OTA type B fractures, nonunions, follow-up less than 12 weeks, and patients aged less than 16 years, 104 sets of radiographs were included for analysis. Anteroposterior and lateral femur radiographs at six weeks, 12 weeks, 24 weeks, and final follow-up were separately scored by three surgeons using the mRUST score. The sensitivity and specificity of mean mRUST score were calculated using clinical and further radiological findings as a gold standard for ultimate fracture healing. A receiver operating characteristic curve was also performed to determine the cut-off points at each time point. Results. The mean mRUST score of ten at 24 weeks revealed a 91.9% sensitivity, 100% specificity, and 92.6% accuracy of predicting ultimate fracture healing. A cut-off point of 13 points revealed 41.9% sensitivity, 100% specificity, and 46.9% accuracy at the same time point. Conclusion. The mRUST score of ten points at 24 weeks can be used as a viable screening method with the highest sensitivity, specificity, and accuracy for healing of metadiaphyseal femur fractures. However, the cut-off point of 13 increases the specificity to 100%, but decreases sensitivity. Furthermore, the mRUST score should not be used at six weeks, as results show an inability to accurately predict eventual fracture healing at this time point. Cite this article: Bone Jt Open 2021;2(10):796–805

Background. Despite arthroscopy being the gold standard for long head of biceps pathology, the literature is seemingly lacking in any critical appraisal or validation to support its use. The aim of this study was to evaluate its appropriateness as a benchmark for diagnosis. The objectives were to evaluate whether the length of the tendon examined at arthroscopy allows visualisation of areas of predilection of pathology and also to determine the rates of missed diagnoses when compared to an open approach. Methods. A systematic review of cadaveric and clinical studies was performed. The search strategy was applied to Medline, PubMed and Google Scholar databases. All relevant articles were included. Critical appraisal of clinical studies was performed using a validated quality assessment scale. Results. Six articles were identified for inclusion in the review. This included both clinical and cadaveric studies. The overall population comprised 25 cadaveric specimens and 575 patients. Cadaveric studies showed that the use of a hook probe allowed arthroscopic visualisation of between 28% and 48% of the overall length of the LHB. In the clinical series the rate of missed diagnoses at arthroscopy when compared to open exploration ranged between 33% and 49%. Conclusions. The standard technique of pulling the LHB tendon into the joint at glenohumeral arthroscopy provides only limited excursion and does not allow visualisation of areas of predilection of pathology. This is confirmed by an extremely high rate of missed diagnoses when comparing arthroscopy to open exploration. It is important that clinicians recognise that a “normal” arthroscopic examination of the LHB tendon does not exclude pathology and that published literature reporting sensitivities and specificities for physical examination and imaging tests based on arthroscopy as a gold standard are invalid. Level of evidence. IIa – systematic review of cohort studies. Conflict of Interests. The authors confirm that they have no relevant financial disclosures or conflicts of interest. Ethical approval was not sought as this was a systematic review

Aim. Implant-associated osteomyelitis is a devastating complication with poor outcomes following treatment, especially when caused by antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). A large animal model of a two-stage revision to treat MRSA implant-associated osteomyelitis has been developed to assess novel treatments. A bioresorbable, thermo-responsive hyaluronan hydrogel (THH) loaded with antibiotics has been developed and our aim was to investigate it´s in vivo efficacy as a local antibiotic carrier compared to the current standard of care i.e. antibiotic-loaded polymethylmethacrylate (PMMA) bone cement. Method. 12 female, 2 to 4 year old, Swiss Alpine Sheep were inoculated with MRSA at the time of intramedullary nail insertion in the tibia to develop chronic osteomyelitis. After 8 weeks sheep received a 2-stage revision protocol, with local and systemic antibiotics. Group 1 received the gold standard clinical treatment: systemic vancomycin (2 weeks) followed by rifampicin plus trimethoprim/sulfamethoxazole (4 weeks), and local gentamicin/vancomycin via PMMA. Group 2 received local gentamicin/vancomycin delivered via THH at both revision surgeries and identical systemic therapy to group 1. Sheep were euthanized 2 weeks following completion of antibiotic therapy. At euthanasia, soft tissue, bone, and sonicate fluid from the hardware was collected for quantitative bacteriology. Results. Sheep tolerated the surgeries and both local and systemic antibiotics well. Gold standard of care successfully treated 3/6 sheep with a total of 10/30 culture-positive samples. All 6 sheep receiving antibiotic-loaded THH were successfully treated with 0/30 culture-positive samples, p=0.0008 gold-standard vs. hydrogel (Fisher's Exact). Conclusions. The clinical gold standard treatment was successful in 50% of sheep, consistent with outcomes reported in the literature treating MRSA infection. The antibiotic-loaded THH clearly outperformed the gold standard in this model. Superior efficacy of the THH is likely due to 1) the ability to administer local antibiotics at the both revision surgies due to the bioresorbable nature of the hydrogel, and 2) complete antibiotic release compared to bone cement, which is known to retain antibiotics. Our results highlight the potential of local delivered, biodegradable systems for antibiotics for eradicating implant-related infection caused by antibiotic-resistant pathogens. Acknowledgement. Funding provided by AO Trauma

The majority of studies reporting sensitivity and specificity data for imaging modalities and physical examination tests for long head of biceps (LHB) tendon pathology use arthroscopy as the gold standard. However, there is little published data to validate this as an appropriate benchmark. The aim of this study was to determine the maximum length of the LHB tendon that can be seen at glenohumeral arthroscopy and whether it allows adequate visualisation of common sites of pathology. Seven female cadaveric specimens were studied. Mean age was 74 years (range 44–96 years). Each specimen underwent arthroscopy in lateral decubitus (LD) and beach chair (BC) positions. The LBH-tendon was tagged with a suture placed with a spinal needle marking the intra-articular length and the maximum excursions achieved using a hook and a grasper in both LD and BC positions. T-tests were used to compare data. The mean intra-articular and extra-articular lengths of the tendon were 23.9 mm and 82.3 mm respectively. The mean length of tendon that could be visualised by pulling it into the joint with a hook was significantly less than with a grasper (LD: hook 29.9 mm, grasper 33.9 mm, mean difference 4 mm, p=0.0032. BC: hook 32.7 mm, grasper 37.6 mm, mean difference 4.9 mm, p=0.0001). Using the BC position allowed visualisation of a significantly greater length than the LD position when using either a hook (mean difference 2.86 mm, p=0.0327) or a grasper (mean difference 3.7 mm, p=0.0077). The mean length of the extra-articular part of the tendon visualised using a hook was 6 mm in LD and 8.9 mm in BC. The maximum length of the extra-articular portion visualised using this technique was 14 mm (17%). Pulling the tendon into the joint with a hook does not allow adequate visualisation of common distal sites of pathology in either LD or BC. Although the BC position allows a significantly greater proportion of the tendon to be visualised this represents a numerically small value and is not likely to be clinically significant. The use of a grasper also allowed greater excursion but results in iatrogenic tendon injury which precludes its use. The reported incidence of pathology in Denard zone C (distal to subscapularis) is 80% and in our study it was not possible to evaluate this zone even by using a grasper or maximum manual force to increase excursion. This is consistent with the extremely high rate of missed diagnoses reported in the literature. Surgeons should be aware that the technique of pulling the LHB-tendon into the joint is inadequate for visualising distal pathology and results in a high rate of missed diagnoses. Furthermore, efforts to achieve greater excursion by “optimum” limb positioning intra-operatively do not confer an important clinical advantage and are probably unnecessary

From February 1992 to December 1997, 379 total hip arthroplasties in 342 patients were performed. 13 patients were lost to follow up, with 33 unrelated deaths. All arthroplasties were performed via the posterior approach in the lateral position. All patients were enrolled in an arthroplasty register at the time of surgery by the operating surgeon. Patients underwent clinical and radiological follow up. Kaplan-Meier survivorship analysis was used to determine the failure rate of the prosthesis, with revision surgery or decision to revise as the end-point. The overall survivorship from all causes of failure at 5–10 years was 99.4%. There were two stem revisions. One stem was revised for aseptic loosening at 4 years and one revised for recurrent dislocation. The stem aseptic loosening rate was 0.26%. The cup aseptic loosening rate was 0%. The dislocation rate was 0.53% (2 from 379). The superficial infection rate was 0.53% (2 from 379). There were no deep infections in this series. At 12 months 71.2% had no pain (270 from 379), and 53.8% (204 from 379) had normal function. 94.5% said the procedure was worthwhile or very good. At 12 months radiological follow-up revealed progressive radioluceny in 7.65% (29 from 379) acetabuli, and progressive radiolucency in 2.90% (11 from 379) femora (one progressing to revision for aseptic loosening). No acetabular cups required revision. In patients aged 65 years or younger at the time of surgery the survivorship was 100% for both components. Attention to meticulous and consistent operative technique in acetabular and femoral preparation, in particular a complete cement mantle with good zone 7 cement and osseointegrated cement bone interfaces, enables these results to be achieved. In 2004 the Charnely Hip replacement remains the Gold Standard hip replacement

Background

The advent of EOS imaging has offered clinicians the opportunity to image the whole skeleton in the anatomical standing position with a smaller radiation dose than standard spine roentgenograms. It is known as the fifth modality of imaging. Current NICE guidelines do not recommend EOS scans over x-rays citing: “The evidence indicated insufficient patient benefit in terms of radiation dose reduction and increased throughput to justify its cost”.

Recent NICE guidelines have suggested abandoning the Thompson hemiarthroplasty (TH) in favour of a ‘proven prosthesis’ such as the Exeter Trauma Stem (ETS). This is controversial because of significant cost implications and limited research assessing outcomes of the ETS. The aim of this study was to assess the treatment of intracapsular neck of femur fractures with the TH. Between 2002 and 2006 (minimum 5 year follow-up), 431 cemented TH's were performed. Death rate at 1 year and 5 years were 26.0% and 67.7% respectively. Dislocation (1.4%) and infection (0.2%) rates were low and revision rate was 1.2%. Comparison was made to Bipolar hemiarthroplasties over the same period (total 194). These had lower rates of dislocation (0.5%) and infection (0.5%) with a significantly higher (3.6%) revision rate. We feel that the TH remains the current gold standard treatment for intracapsular fractures, in appropriate patients, due to low complication and revision rates. Modern implants may provide better function or longevity, but there is no evidence in the literature to support abandoning the TH. Surgeons should assess patients and decide on its use, despite NICE guidelines, as it remains a cost effective treatment method, particularly for older, less mobile and cognitively impaired patients

A majority of patients present with varus alignment and predominantly medial compartment disease. The secret of success in osteoarthritis (OA) treatment is patient selection and patient specific treatment. Different wear patterns have been described and that knowledge should be utilised in modern knee surgery. In case of isolated anteromedial OA, unicompartmental knee arthroplasty (UKA) should be one of the therapeutic options available to the knee surgeon.

The discussion not to offer a UKA to patients is based on the fear of the surgeon not being able to identify the right patient and not being able to perform the surgery accurately. The common modes of failure for UKA, which are dislocation or overcorrection leading to disease progression, can be avoided with a fixed bearing implant. Wear can probably be avoided with newer polyethylenes and avoidance of overstuffing in flexion of the knee. Revision for unexplained pain and unknown causes should disappear once surgeons understand persistent pain after surgery much better than they do today.

The choice in favor of UKA is a choice of function over survivorship, a choice for reduced comorbidity and lower mortality. Many of the common problems in TKA are not an issue in UKA. Component overhang, decreased posterior offset, changed joint line height, gap mismatch, flexion gap instability, lift off and paradoxical motion hardly exist in UKA if the replacement is performed according to resurfacing principles with respect for the native knee anatomy.

New technologies like navigation, PSI and robotics will help with alignment and component positioning. Surgeon education and training should allow over time UKA to be performed by all of us.

There exists a variety of options for a medial compartment knee with osteoarthritis, specifically a unicompartmental knee, high tibial osteotomy, and total knee arthroplasty. This surgeon prefers a rotating platform posterior stabilised total knee to the unicompartmental knee. Unicompartmental knee arthroplasty (UKA) in younger patients is being performed with increasing frequency. While UKA is a powerful marketing tool because of its minimally invasive nature and quality of knee function that is superior to the total knee arthroplasty (TKA), it has tremendous drawbacks. These include: the selection criteria is very specific and the number of patients that fit in that category is small, there is a steep learning curve for the surgeon to perfect the technique, higher failure due to wear and loss of fixation, and unexplained pain. Based on level 1 and 2 evidence available it is not justified to do more UKAs at present when the results of a TKA are so successful.

Frozen section is a recognised technique to assist in the diagnosis of infection and there are standards for reporting. Our aim of this review was to assess the value of frozen section in the diagnosis of infection, as well as other variables.

We performed a retrospective review of all frozen sections for suspected infection in 2016. Patient demographics, histological and microbiological investigations, laboratory and bedside tests were recorded and analysed using statistical software.

46 patients had 55 frozen sections; the majority were for lower limb arthroplasty. No sections were reported as polymorphonuclear neutrophils per high-power field. Three sections showed signs of infection and one without evidence had positive cultures. One uncertain section did not grow organisms. 10 patients had two-stage procedures, four of these were intended to be determined by frozen section but only two had evidence of infection on analysis.

Evidence of infection on frozen section does correlate with microbiological growth but does not relate to intention to stage procedures in half of patients. The effect of new tests such as Synovasure is highlighted by this review.

Frozen section analysis is reported subjectively but is a good predictor of infection. Clinical assessment is accurate in diagnosing infection. Histological, microbiological and additional investigations should be considered in relation to their cost-effectiveness.

Radiographs historically have not been standardized according to magnification. Depending upon the size of a patient, a film will either magnify a bone and joint (of large patients with more soft tissue) or minify (in the case of thin patients). An orthopedic surgeon must guess at the degree of over or under magnification to select an implant that is neither too large nor too small. The surgeon may be aided by the incorporation of a marker of known size. By calculating the difference between the size of the marker displayed on the film and the actual size of the marker, the orthopedic surgeon can identify the degree of magnification/minimization and compensate accordingly when selecting a prosthetic template.

This activity takes time and also is subject to mathematical error. Digital pre-op planning allows for an image to be displayed electronically, and with the use of a known sized marker, automatically calculate the magnification and recalibrate the image so that it is sized at 100% from the perspective of the user.

Digital pre-op planning incorporates a library of electronic templates of prostheses, which can be standardized to exactly match the size of diagnostic image being displayed. Traditionally, an orthopedic surgeon places an acetate template enlarged to be 110% to 120% over an X-ray film magnified to be110% to 130%. When there is a significant variation in magnification between the template and the procedure, this can contribute to surgical error. This type of error will be virtually eliminated with digital templating that has the capability to identically scale electronic templates to the X-ray image being displayed. Digital pre-op planning enables surgeons to select from a library of templates and electronically overlay them on an image as well as perform the necessary measurements critical to the templating procedure which not only speeds up this process but, as will be shown, has the potential of delivering unprecedented accuracy.

This prospective randomized multicenter study compares two methods of bone defect treatment in tibial plateau fractures: a bioresorbable calcium phosphate paste (Alpha-BSM) that hardens at body temperature to give structural support versus Autogenous iliac bone graft (AIBG). One hundred and eighteen patients were enrolled with a 2:1 randomization, Alpha-BSM to AIBG. There was a significant increased rate of non-graft related adverse affects and a higher rate of late articular subsidence (three to nine month period) in the AIBG group. A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures. This prospective randomized multicenter study was undertaken to compare two methods of bone defect treatment: a bioresorbable calcium phosphate paste (Alpha-BSM –DePuy, Warsaw, IN) that hardens at body temperature to give structural support and is gradually resorbed by a cell-mediated bone regenerating mechanism versus Autogenous iliac bone graft (AIBG). One hundred and eighteen adult acute closed tibial plateau fractures, Schatzker grade two to six were enrolled prospectively from thirteen study sites in North America from 1999 to 2002. Randomization occurred at surgery with a FDA recommendation of a 2–1 ratio, Alpha BSM (seventy-eight fractures) to AIBG (forty fractures). Only internal fixation with standard plate and screw constructs was permitted. Follow-up included standard radiographs and functional studies at one year, with a radiologist providing independent radiographic review. The two groups exhibited no significant differences in randomization as to age, sex, race, fracture patterns or fracture healing. There was however, a significant increased rate of non-graft related adverse affects in the AIBG group. There was an unexpected significant finding of a higher rate of late articular subsidence in the three to nine month period in the AIBG group. Recommendations for the use of AIBG for bone defects in tibial plateau fractures should be discouraged in favor of bioresorbable calcium phosphate material with the properties of Alpha BSM. We believe further randomized studies using AIBG as a control group for bone defect support of articular fractures are unjustified. A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures. Funding: DePuy, Warsaw, IN

Adolescent idiopathic scoliosis is known to aggregate within families; however, the pattern of inherited susceptibility is unclear. A genomic screen and statistical linkage analysis of a genetic isolate including individuals with idiopathic scoliosis is being performed to identify variants responsible for this disease.

Scoliosis does not demonstrate a characteristic pattern of classical genetic (inherited) disorders. The severity of the disease within families can change and sometimes generations are skipped. However, the role of hereditary or genetic factors in the development of this condition is widely accepted. Numerous investigators are currently attempting to locate these genes. Studies based on a wide variety of populations have suggested an autosomal dominant mode of inheritance or sex-linked inheritance pattern. Other authors state that the “genetics link” may be complex, with an interaction of several genes rather than just one.

To identify chromosomal loci encoding genes involved in susceptibility to idiopathic scoliosis and the trasmission way of scoliosis we are studing a genetic isolate. We have generated a 10,600 individual pedigree of the village of Campora, in the Cilento area, starting from the beginning of the 17th century connecting all the 1200 living inhabitants. The actual population of Campora derives from a few founders; therefore, the living inhabitants are all related to each other. The population will undergo clinical and radiographic evaluation for the presence and degree of scoliosis. A genomic screen and statistical linkage analysis of the families with individuals having idiopathic scoliosis will be performed. With this approach we can identify variants responsible for this complex disease and genetic links of scoliosis.

The aim of this study is to assess the accuracy of clinical examination of the knee compared to MRI and Arthroscopy in diagnosing significant internal derangement.

We performed a retrospective analysis on 245 patients who underwent an MRI of the knee over a two-year period. The MRI diagnoses were compared with both clinical and arthroscopic findings. There were 169 male and 76 female patients with an average age of 33 years. A history of significant trauma was seen in 98 (40%) patients. The commonest clinical diagnosis was isolated medial meniscal tear (25%). Anterior cruciate ligament (ACL) tear was diagnosed in 8% and lateral meniscal tear in 7% of cases. No definite clinical diagnosis could be reached in 32% of patients. MRI showed no significant abnormality in 103 (42%) patients. Medial meniscal tear was noted in 47 (19%), ACL tear in 20 (8%) and lateral meniscal tear in 10 (4%) of the MRI scans. 96 patients (39%) proceeded to arthroscopy after their MRI scans. The mean time from MRI scan to arthroscopy was 181 days. The MRI and arthroscopy findings were in complete agreement in 90 (94%) patients. Of the 6 patients whose MRI findings did not correlate with arthroscopy, 4 showed meniscal tears not seen at surgery and two diagnosed ACL ruptures subsequently shown to be normal at arthroscopy. Three of the 4 meniscal tears were of the inferior surface of the posterior horn of the medial meniscus and one of the inferior surface of the lateral meniscus. The films were reviewed independently by three experienced MR radiologists all of whom confidently diagnosed a tear in each case.

Clinical examination alone is not satisfactory in the diagnosis of knee injuries. MRI is a highly sensitive tool for diagnosis. Injuries that are commonly missed at arthroscopy can be diagnosed easily with MRI.

Aim:

An analysis of significant neuromonitoring changes (NMCs) and evaluation of the efficacy of multimodality neuromonitoring in spinal deformity surgery.

Purpose: To determine if multidetector-row CT (MDCT) can replace conventional radiographs and be performed alone in severe trauma patients for the depiction of thoracolumbar spine fractures. Materials and Methods: One hundred consecutive severe trauma patients who underwent conventional radiographs of the thoracolumbar spine as well as thoraco-abdominal MDCT were prospectively identiþed. Conventional radiographs were reviewed independently by 3 radiologists and 2 orthopedic surgeons, and MDCT by 3 radiologists. Reviewers were blinded both to each other and to the results of the initial evaluation of these examinations. Presence, location and stability of fractures, as well as quality of reviewed imaging methods were assessed. Statistical analysis was performed to determine sensitivity and inter-observer agreement of each procedure, with clinical and radiological follow-up chosen as the reference standard. Time to perform each examination as well as involved radiation doses were also evaluated. Finally, a resource cost analysis was performed. Results: Sixty-seven fractured vertebrae in 26 of the patients were diagnosed. Twelve patients showed unstable spine fractures. Sensitivity and inter-observer agreement for unstable fractures amounted to 97.2% and 95.1% with MDCT, and 33.3% and 36.8% with conventional radiology. Average times in the performance of conventional radiographs and MDCT examinations amounted to 33 minutes and 40 minutes, respectively. Effective radiation doses involved in conventional radiographs of the spine and thoraco-abdominal MDCT amounted to 6.36 mSv and 19.42 mSv, respectively. MDCT afforded identiþcation of 145 associated traumatic lesions. Finally, costs of conventional radiographs and of MDCT amounted to 145 US$ and 880 US$ per patient, respectively. Conclusion: MDCT is a better test for depicting spine fractures than conventional radiographs. It can replace conventional radiographs and be performed alone in severe trauma patients.

Bone age is a radiographical assessment used in pediatric medicine due to its relative objectivity in determining biological maturity compared to chronological age and size.1 Currently, Greulich and Pyle (GP) is one of the most common methods used to determine bone age from hand radiographs.2–4 In recent years, new methods were developed to increase the efficiency in bone age analysis like the shorthand bone age (SBA) and the automated artificial intelligence algorithms. The purpose of this study is to evaluate the accuracy and reliability of these two methods and examine if the reduction in analysis time compromises their accuracy. Two hundred thirteen males and 213 females were selected. Each participant had their bone age determined by two separate raters using the GP (M1) and SBA methods (M2). Three weeks later, the two raters repeated the analysis of the radiographs. The raters timed themselves using an online stopwatch while analyzing the radiograph on a computer screen. De-identified radiographs were securely uploaded to an automated algorithm developed by a group of radiologists in Toronto. The gold standard was determined to be the radiology report attached to each radiograph, written by experienced radiologists using GP (M1). For intra-rater variability, intraclass correlation analysis between trial 1 (T1) and trial 2 (T2) for each rater and method was performed. For inter-rater variability, intraclass correlation was performed between rater 1 (R1) and rater 2 (R2) for each method and trial. Intraclass correlation between each method and the gold standard fell within the 0.8–0.9 range, highlighting significant agreement. Most of the comparisons showed a statistically significant difference between the two new methods and the gold standard; however it may not be clinically significant as it ranges between 0.25–0.5 years. A bone age is considered clinically abnormal if it falls outside 2 standard deviations of the chronological age; standard deviations are calculated and provided in GP atlas.6–8 For a 10-year old female, 2 standard deviations constitute 21.6 months which far outweighs the difference reported here between SBA, automated algorithm and the gold standard. The median time for completion using the GP method was 21.83 seconds for rater 1 and 9.30 seconds for rater 2. In comparison, SBA required a median time of 7 seconds for rater 1 and 5 seconds for rater 2. The automated method had no time restraint as bone age was determined immediately upon radiograph upload. The correlation between the two trials in each method and rater (i.e. R1M1T1 vs R1M1T2) was excellent (κ= 0.9–1) confirming the reliability of the two new methods. Similarly, the correlation between the two raters in each method and trial (i.e. R1M1T1 vs R2M1T1) fell within the 0.9–1 range. This indicates a limited variability between raters who may use these two methods. The shorthand bone age method and an artificial intelligence automated algorithm produced values that are in agreement with the gold standard Greulich and Pyle, while reducing analysis time and maintaining a high inter-rater and intra-rater reliability

Polyetheretherketone (PEEK) interbody fusion cages combined with autologous bone graft is the current clinical gold standard treatment for spinal fusion, however, bone graft harvest increases surgical time, risk of infection and chronic pain. We describe novel low-stiffness 3D Printed titanium interbody cages without autologous bone graft and assessed their biological performance in a pre-clinical in vivo interbody fusion model in comparison to the gold standard, PEEK with graft. Titanium interbody spacers were 3D Printed with a microporous (Ti1: <1000μm) and macroporous (Ti2: >1000μm) design. Both Ti1 and Ti2 had an identical elastic modulus (stiffness), and were similar to the elastic modulus of PEEK. Interbody fusion was performed on L2-L3 and L4-L5 vertebral levels in 24 skeletally mature sheep using Ti1 or Ti2 spacers, or a PEEK spacer filled with iliac crest autograft, and assessed at 8 and 16 weeks. We quantitatively assessed bone fusion, bone area, mineral apposition rate and bone formation rate. Functional spinal units were biomechanically tested to analyse range of motion, neutral zone, and stiffness. Results: Bone formation in macroporous Ti2 was significantly greater than microporous Ti1 treatments (p=.006). Fusion scores for Ti2 and PEEK demonstrated greater rates of bone formation from 8 to 16 weeks, with bridging rates of 100% for Ti2 at 16 weeks compared to just 88% for PEEK and 50% for Ti1. Biomechanical outcomes significantly improved at 16 versus 8 weeks, with no significant differences between Ti and PEEK with graft. This study demonstrated that macroporous 3D Printed Ti spacers are able to achieve fixation and arthrodesis with complete bone fusion by 16 weeks without the need for bone graft. These significant data indicate that low-modulus 3D Printed titanium interbody cages have similar performance to autograft-filled PEEK, and could be reliably used in spinal fusion avoiding the complications of bone graft harvesting

Validation of a new meniscal root repair technique that will be biomechanically superior to current gold standard procedures and, at the same time, will allow controlled adjustable fixation. Medial and lateral meniscus from 10 porcine knees were collected. An iatrogenic posterior root tear was created and a single transosseous tibial tunnel technique that closely replicates the repair procedure with a 2-mm-wide-knottable braided tape was performed. Randomly, in one group (A) two simple cinch stitch were applied to suture the posterior root of the meniscus and, in the other group (B), a simple stich that holds the meniscus in two points in a crosse match configuration was used. For final fixation, alternating surgeon's knots (A group) and a doubled suture knot that allows an adjustable fixation were used (B group). All repairs were standardized for location and the repair stiches were placed in the body of the meniscus. The new suture configuration (B group) showed a better biomechanical performance in terms of load for both the medial [151,0-560,3] 306,9±173,8N and the lateral posterior root fixation [268,2-463,1] 347,4±74,3N in comparison to the cinch stitch (A group) [219,0-365,2] 268,9±58,7N and [219,0-413,6] 318,0±72N. The maximum stiffness was also higher for the new tested suture configuration (B group) for both the medial meniscus [10,6-34,5] 18,9±9,2N/mm vs [7,1-12,7] 10,9±2,2N/mm and the lateral meniscus [16,0-27,9] 21,6±5,5N/mm vs [7,6-15,6] 12,6±3,5N/mm. The presented new meniscal root repair is biomechanically superior to current gold standard techniques, as the cinch stich made with tape, keeping the simplicity and reproducibility of the procedure and, at the same time, is economically advantageous since a single tape in needed and allows adjustable fixation of the repair over a button

Evaluation of patient specific spinopelvic mobility requires the detection of bony landmarks in lateral functional radiographs. Current manual landmarking methods are inefficient, and subjective. This study proposes a deep learning model to automate landmark detection and derivation of spinopelvic measurements (SPM). A deep learning model was developed using an international multicenter imaging database of 26,109 landmarked preoperative, and postoperative, lateral functional radiographs (HREC: Bellberry: 2020-08-764-A-2). Three functional positions were analysed: 1) standing, 2) contralateral step-up and 3) flexed seated. Landmarks were manually captured and independently verified by qualified engineers during pre-operative planning with additional assistance of 3D computed tomography derived landmarks. Pelvic tilt (PT), sacral slope (SS), and lumbar lordotic angle (LLA) were derived from the predicted landmark coordinates. Interobserver variability was explored in a pilot study, consisting of 9 qualified engineers, annotating three functional images, while blinded to additional 3D information. The dataset was subdivided into 70:20:10 for training, validation, and testing. The model produced a mean absolute error (MAE), for PT, SS, and LLA of 1.7°±3.1°, 3.4°±3.8°, 4.9°±4.5°, respectively. PT MAE values were dependent on functional position: standing 1.2°±1.3°, step 1.7°±4.0°, and seated 2.4°±3.3°, p< 0.001. The mean model prediction time was 0.7 seconds per image. The interobserver 95% confidence interval (CI) for engineer measured PT, SS and LLA (1.9°, 1.9°, 3.1°, respectively) was comparable to the MAE values generated by the model. The model MAE reported comparable performance to the gold standard when blinded to additional 3D information. LLA prediction produced the lowest SPM accuracy potentially due to error propagation from the SS and L1 landmarks. Reduced PT accuracy in step and seated functional positions may be attributed to an increased occlusion of the pubic-symphysis landmark. Our model shows excellent performance when compared against the current gold standard manual annotation process