Introduction. Decreasing tissue damage and recovery time, while improving quality of life have been the focus of many approaches to total hip arthroplasty (THA). In this study, we compared two approaches, a tissue-sparing superior capsulotomy percutaneously assisted approach (SP) and the traditional posterior approach (TR), to address the question of whether the novel technique reduces tissue damage. The secondary aim of this study focused on the measurement technologies utilized to quantify the damage resulting from either SP or TR. Image J, BioQuant, and cellSens were the image analysis programs employed. Statistical validation and comparisons of results between all platforms were performed. Methods. Both hips of freshly frozen cadaveric specimens (n = 8) were surgically prepared for THA with random procedure performed on left or right hip. All selected specimens had no prior implantation of devices to ensure all observed muscle damage occurred from the surgical technique. Surgeons resected tissue and performed necessary procedural steps up to device implantation. No devices were implanted during the study, as the aim was to quantify the damage caused by the incision and resection. After completion of the surgery, an independent surgeon (IS), who was blinded as to which method was performed on the specimen, excised the muscles and inspected areas of interest Assessment of the tissue damage was executed using a midsubstance cross-sectional area technique, validated by prior studies. High-resolution images of demarcated muscles were used for quantitative analysis. Three blinded independent reviewers quantified damaged tissue. The results were used to detect if statistically significant differences were present between the two methods. Furthermore, an independent reviewer using SPSS statistical software also assessed inter-program and inter-rater reliability. Results. The SP procedure significantly reduced percent of damaged GM tissue. GS tissue damage reduction with SP procedure was observed but the difference was not statistically significant. Between raters, the intraclass correlation coefficient (ICC) for the tissue damage measures was 0.870 (95% CI: 0.824 – 0.907). Within the individual applications, BioQuant and Image J had ICCs of 0.972 and 0.987, respectively. CellSens, however had an ICC value of 0.671. Discussion. For the three image analysis programs chosen, the damaged tissue was quantified within the software application and each user defined areas of interest slightly different, which reduced the interrater reliability. However, variation in the software may affect the degree of difference detected and/or the p-value. There was a statistically significant reduction in percent of damaged tissue, SP vs. TR, in the GM obtained from all programs. A statistically significant reduction in GS damage, SP vs. TR, was not detected in either program, which may be a result of the limited sample size. Significance. New surgical techniques require evaluation to determine if there are objective advantages over other techniques. Preclinical evaluation of these techniques has been limited. Providing quantitative evidentiary support has clinical and scientific relevance to patients, physicians, and healthcare providers.. Independent analysis of these results may depend on the user interface of image analysis programs and should be evaluated by multiple raters to ensure accuracy

INTRODUCTION. Interest in tissue-preserving or minimally invasive total hip arthroplasty (THA) is increasing with focus toward decreased hospital stay, enhanced rehabilitation, and quicker recovery for patients. Two tissue-preserving techniques, the anterior and superior approaches to THA, have excellent clinical results, but little is known about their relative impact on soft tissue. The purpose of this study was to evaluate the type and extent of tissue damage after THA with each approach, focusing on abductors, short external rotators, and the hip capsule. METHODS. Total hip arthroplasty was performed on bilateral hips of eleven fresh-frozen cadavers (22 hips). They were randomized to anterior THA performed on one side and superior THA performed on the other, in the senior authors' standard technique. Two independent examiners graded the location and extent of tissue injury by performing postsurgical dissections. Muscle bellies, tendons, and capsular attachments were graded as intact, split, damaged (insignificant, minimal, moderate, or extensive damage), or detached based on direct visual inspection of each structure. Tissue injury was analyzed with either a chi-squared (≥5 qualifying structures) or Fisher's exact test (<5 qualifying structures). P values <0.05 were significant. RESULTS. The abductor muscles or tendons were intact or insignificantly damaged in 63.6% of anterior approach specimens compared with 84.1% of the superior specimens (p= 0.03). Specifically, the gluteus minimus tendon had moderate or extensive damage in 63.6% of anterior specimens compared with none of the superior specimens (p <0.01). Short external rotators (SERs) group, defined as both the muscle and tendon of the piriformis, conjoint, obturator externus, and quadratus, were intact or insignificantly damaged in 63.6% of anterior approach specimens compared with 80.5% of the SER group of superior specimens (p = 0.02). The femoral attachments of the anterior, posterior, and superior capsules were extensively damaged or detached in 90.9%, 81.8%, and 100% of anterior approach specimens respectively compared with 0%, 9.1% and 9.1% of superior approach specimens respectively (all p <0.01). CONCLUSION. In a cadaveric study examining superior and anterior approaches to THA, the superior approach demonstrated significantly less soft-tissue destruction than the anterior approach, specifically to the gluteus minimus tendon, short external rotators, and the hip capsule

Background. Although tourniquets are widely used in total knee arthroplasty (TKA), their influence on the postoperative course is still unclear. In addition, tourniquet-related soft tissue damage is a major concern in daily practice. We performed a prospective, randomized controlled trial to clarify the role of tourniquets in TKA. Methods. Seventy-two patients undergoing TKA were randomly allocated to a tourniquet or non-tourniquet group. Changes in C-reactive protein, creatine phosphokinase, and other indicators of soft tissue damage were monitored preoperatively and postoperatively on days 1, 2, and 4. Rehabilitation progress was also recorded for comparison. Results. Patients in the tourniquet group showed smaller increases in C-reactive protein (peak values: 175 ± 55 versus 139 ± 75 mg/dl) and creatine phosphokinase (peak values: 214 ± 89 versus 162 ± 104 U/l) compared those in the non-tourniquet group. There was slightly less postoperative pain in the non-tourniquet group, and no significant differences in swelling, or rehabilitation progress. Conclusions. Using tourniquets in TKA was effective for reducing blood loss and avoiding excessive postoperative inflammation and muscle damage. Tourniquets caused slightly more postoperative pain but did not affect postoperative recovery

Introduction

The low-cost, no-harm conditions associated with vibroarthography, the study of listening to the vibrations and sound patterns of interaction at the human joints, has made this method a promising tool for diagnosing joint pathologies. This current study focuses on the knee joint and aims to synchronize computational models with vibroarthographic signals via a comprehensive graphical user interface (GUI) to find correlations between kinematics, vibration signals, and joint pathologies. This GUI is the first of its kind to synchronize computational models with vibroarthographic signals and gives researchers a new advantage of analyzing kinematics, vibration signals, and pathologies simultaneously in an easy-to-use software environment.

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation. Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure. Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue. The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing. Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots. The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot. The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05. The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue. The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation. Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure. Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue. The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing. Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots. The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot. The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05. The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue. The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing

With the success of the medial parapatellar approach (MPA) to total knee arthroplasty (TKA), current research is aimed at reducing iatrogenic microneurovascular and soft tissues damage to the knee. In an effort to avoid disruption to the medial structures of the knee, we propose a novel quadriceps-sparing, subvastus lateralis approach (SLA) to TKA. The aim of the present study is to compare if a SLA can provide adequate exposure of the internal compartment of the knee while reducing soft tissue damage, compared to the MPA. Less disruption of these tissues could translate to better patient outcomes, such as reduced post-operative pain, increased range of motion, reduced instances of patellar maltracking or necrosis, and a shorter recovery time. To determine if adequate exposure could be achieved, the length of the skin incision and perimeter of surgical exposure was compared amongst 22 paired fresh-frozen cadaveric lower limbs (five females/six males) which underwent TKA using the SLA or MPA approach. Additionally, subjective observations which included the percent of visibility of the femoral condyles and tibial plateau, as well as the patellar tracking, were noted in order to qualify adequate exposure. All procedures were conducted by the same surgeon. Subsequently, to determine the extent of soft tissue damage associated with the approaches, an observational assessment of the dynamic and static structures of the knee was performed, in addition to an examination of the microneurovascular structures involved. Dynamic and static structures were assessed by measuring the extent of muscular and ligamentus damage during gross dissection of the internal compartment of the knee. Microneurovascular involvement was evaluated through a microscopic histological examination of the tissue harvested adjacent to the capsular incision. Comparison of the mean exposure perimeter and length of incision was not significantly different between the SLA and the MPA (p>0.05). In fact, on average, the SLA facilitated a 5 mm larger exposure perimeter to the internal compartment, with an 8 mm smaller incision, compared to the MPA, additional investigation is required to assert the clinical implications of these findings. Preliminary analysis of the total visibility of the femoral condyles were comparable between the SLA and MPA, though the tibial plateau visibility appears slightly reduced in the SLA. Analyses of differences in soft tissue damage are in progress. Adequate exposure to the internal compartment of the knee can be achieved using an incision of similar length when the SLA to TKA is performed, compared to the standard MPA. Future studies should evaluate the versatility of the SLA through an examination of specimens with a known degree of knee deformity (valgus or varus)

Introduction. Robot systems have been successfully introduced to improve the accuracy and reduce severe iatrogenic soft tissue damage in knee arthroplasty. Unfortunately to perform complete a complete bone cut, the cutting tool has to slightly pass the edge of the bone. In the posterior zones were retractor protection is impossible this will lead to contact between the cutting tool and the soft tissue envelope. Therefore, complete soft tissue preservation cannot be guaranteed with the current commercial systems. Methods. This study presents an alternative robotic controlled cutting technique to perform the bone resections during TKA by milling a slot with a long slender high-speed milling tool. The system is composed by a long milling tool driven by a high-speed motor and a protector covering the end of the cutter. The protector is rigidly connected to the motor by the support structure next to the mill, which moves behind the mill in the slot created by the cutter. The protector at the end of the cutter has four functions: providing mechanical support for the mill, preventing soft tissue to come into contact with the cutter, sensing the edge of the bone to accurately follow the shape of the bone and releasing the attached soft tissue. The edge of the bone is sensed by force feedback and with the help of a probing motion the adaptive algorithm enables the protector to follow the edge of the bone closely by compensating for small segmentation and registration errors. A pilot test to evaluate the concept was performed on three fresh frozen knees. The flatness of the resection, the iatrogenic soft tissue damage, the cutting time and the efficiency of the bone contour following algorithm was measured. Results. An Rq flatness of 0.10±0.03 mm and the Rt flatness of 0.52±0.08 was obtained. The MASTI score for soft tissue damage was 34.11±1.0 resulting in two A scores and one B score. The active contour following algorithm was capable of predicting the physical location of the bone three times more accurate compared to the initial surface based registration (1.51±0.31 mm to 0.44±0.29 mm). The cutting time was 106±7 s. Discussion. The mean flatness was about three times better compared to the oscillating saw and in line with other active robots using a mill. In contrast to other orthopaedic robotic systems with a rotating cutter, this technique enables performing each resection in TKA in one movement. Therefore the new approach was significantly faster compared to other active robotic systems using a mill. Because of the active shielding of the cutter, only very little superficial soft tissue was observed. Furthermore, the adaptive bone contour approach opens the possibility for imageless active robotic knee arthroplasty. Conclusion. The promising results of this pilot study demonstrate the potential of the novel soft tissue protecting cutter by combining the accuracy of a cylindrical mill with an active soft tissue protection while reducing the cutting time

Repetitive manual handling caused 31% of all work related musculoskeletal disorders in 2015, with the back being the site of injury 38% of the time. Despite its high resilience, studies have shown that intervertebral discs can be damaged during repetitive loading at physiological motions, causing cumulative damage and disc herniation. To understand the mechanism of disc injury resulting from repetitive lifting, it is important to measure disc deformations/strains accompanied by MRI imaging to identify disc tissue damage. Therefore, the aim of this study was to examine associations between the magnitude of 3D internal strains, tissue damage and macroscopic evidence of disc injury after simulated repetitive lifting on normal human lumbar discs. Sixteen cadaver lumbar functional spinal units (FSUs) were subjected to pre-test MRI. Eight FSUs (control) underwent 20,000 cycles or until failure (5 mm displacement) of loading under compression (1.7 MPa – to simulate lifting a 20 kg weight) + flexion (13°) + right axial rotation (2°) using a novel Hexapod Robot. The remaining eight FSUs (experimental) had a grid of tantalum wires inserted, and stereoradiographs were taken to track internal disc displacements at increasing cyclic intervals. Maximum shear strains (MSS) were calculated from the displacements using radiostereometric analysis at cycle 1 and 20,000 cycles (or failure). Post-test MRI was conducted to determine the extent of tissue damage and associated with regions of highest MSS. A repeated measures ANOVA was performed on MSS with a within–subjects factor of cycle number (cycle 1 and failure cycle) and a between subjects-factor of disc region and failure type (p < 0 .05). Pfirrmann grading revealed mostly normal discs [I (N=2), II (N=13), and III (N=1)]. No significant difference in MSS between control and experimental groups was found for number of cycles to failure (p=0.279). Pre and post-test MRI analysis revealed that 13 specimens were injured after repetitive lifting with either an endplate failure (N=9) or disc bulge (N=4), and two specimens did not fail. Failure strain was significantly greater than cycle 1 in all regions except posterior, left/right posterolateral (p>0.109). Largest MSS at failure was seen in the anterior (60%), and left/right posterolateral regions (64% and 70%, respectively). MSS at failure for the endplate failure group was significantly larger than the no injury group in all regions except right lateral and nucleus (p>0.707). Disc bulge group MSS was significantly larger than the no injury group in the anterior, right anterolateral, and left/right posterolateral regions (p < 0 .027). Simulated repetitive lifting led to largest shear strains in the anterior, left and right posterolateral regions that corresponded to annular tears or annular protrusion. The no injury group shear strain was less than 50% in all regions, indicating there may be a threshold that could be associated with tissue damage linked with injuries such as disc bulge and endplate failure. There was no evidence of disc herniation in normal discs, agreeing with current clinical knowledge. These results may be indicative of the effects of repetitive manual handling on normal discs of younger patients

Prosthetic joint infection (PJI) is a complex disease that causes significant damage to the peri-implant tissue. Developing an animal model that is clinically relevant in depicting this disease process is an important step towards developing novel successful therapies. In this study, we have performed a thorough histologic analysis of peri-implant tissue harvested post Staphylococcus aureus (S. aureus) infection of a cemented 3D-printed titanium hip implant in rats. Sprague-Dawley rats underwent left hip cemented 3D-printed titanium hemiarthroplasty via posterior approach under general anesthesia. Four surgeries were performed for the control group and another four for the infected group. The hip joint was inoculated with 5×10. 9. CFU/mL of S. aureus Xen36 prior to capsule closure. The animals were scarified 3 weeks after infection. The femur was harvested and underwent micro-CT and histologic analysis. Hematoxylin and eosin (H&E), as well as Masson's trichrome (MT) stains were performed. Immunohistochemistry (IHC) using rabbit antibody for S. aureus was also used to localize bacterial presence within femur and acetabulum tissue . The histologic analysis revealed strong resemblance to tissue changes in the clinical setting of chronic PJI. IHC demonstrated the extent of bacterial spread within the peri-implant tissue away from the site of infection. The H&E and MT stains showed 5 main features in infected bone: 1) increased PMNs, 2) fibrovascular inflammation, 3) bone necrosis, and 4) increased osteoclasts 5) fibrosis of muscular tissue and cartilage. Micro CT data showed significantly more osteolysis present around the infected prosthesis compared to control (surgery with no infection). This is the first clinically relevant PJI animal model with detailed histologic analysis that strongly resembles the clinical tissue pathology of chronic PJI. This model can provide a better understanding of how various PJI therapies can halt or reverse peri-implant tissue damage caused by infection

Background. Use of a robotic tool to perform surgery introduces a risk of unexpected soft tissue damage due to the uncommon tactile feedback for the surgeon. Early experience with robotics in total hip and knee replacement surgery reported having to abort the procedure in 18–34 percent of cases due to inability to complete preoperative planning, hardware and soft tissue issues, registration issues, as well as concerns over actual and potential soft tissue damage. These can result in significant morbidity to the patient, negating all the desired advantages of precision and reproducibility with robotic assisted surgery. The risk of soft tissue damage can be mitigated by haptic software prohibiting the cutting tip from striking vital soft tissues and by the surgeon making sure there is a clear workspace path for the cutting tool. This robotic total knee system with a semi-active haptic guided technique was approved by the FDA on 8/5/2015 and commercialized in August of 2016. Two year clinical results have not been reported to date. Objective. To review an initial and consecutive series of robotic total knee arthroplasties for safety in regard to avoidance of known or delayed soft tissue injuries and the necessity to abort the using the robot to complete the procedure. Report the clinical outcomes with robotic total knee replacement at or beyond two years to demonstrate no delayed effect on expected outcome. Methods. The initial consecutive series of 65 Triathlon. TM. total knee replacements using a semi-active haptic guided system that were performed after commercialization that would be eligible for two year follow-up were reviewed. Pre-operative planning utilizing CT determined the implant placement and boundaries and thus the limit of excursion from any part of the end effector saw tip. Self-retaining retractors were also utilized. Operative reports, 2, 6, and 12 week, and yearly follow-up visit reports were reviewed for any evidence of inadvertent injury to the medial collateral ligament, patellar tendon, or a neurovascular structure from the cutting tool. Operative notes were also reviewed to determine if the robotic procedure was partially or completely aborted due to any issue. Knee Society Knee Scores (KS-KS) and Functional Scores (KS-FS) were recorded from pre-operative and yearly. Any complications were recorded. Results. 40 cases had two year follow-up. The average follow-up for this series was 1.51 years. No cases were unable to be completed robotically. No case had evidence for acute or delayed injury to the medial collateral ligament, patellar tendon, or neurovascular structure. The only complication was a revision total knee for tibial component loosening after a fall induced periprosthetic tibial fracture. Average pre-operative KS-KS and KS-FS improved from 46.9 and 52.1 to 99.2 and 88.6 at one year follow-up, 100.5 and 86.9 at two year follow-up. Conclusions. A semi-active haptic guided robotic system is a safe and reliable method to perform total knee replacement surgery. This series of initial robotic arm assisted surgery had no intraoperative or delayed soft tissue injuries. Preliminary short-term outcomes at up to two years show excellent outcomes

Background. Use of a robotic tool to perform surgery introduces a risk of unexpected soft tissue damage due to the lack of tactile feedback for the surgeon. Early experience with robotics in total hip and knee replacement surgery reported having to abort the procedure in 18–34 percent of cases due to inability to complete preoperative planning, hardware and soft tissue issues, registration issues, as well as concerns over actual and potential soft tissue damage. These damages to the soft tissues resulted in significant morbidity to the patient, negating all the desired advantages of precision and reproducibility with robotic assisted surgery. The risk of soft tissue damage can be mitigated by haptic software prohibiting the cutting tip from striking vital soft tissues and by the surgeon making sure there is a clear workspace path for the cutting tool. This robotic total knee system with a semi-active haptic guided technique was approved by the FDA on 8/5/2015 and commercialized in August of 2016. One year clinical results have not been reported to date. Objective. To review an initial and consecutive series of robotic total knee arthroplasties for safety in regard to avoidance of known or delayed soft tissue injuries and the necessity to abort the robotic assisted procedure and resort to the use of conventional implantation. Report the clinical outcomes with robotic total knee replacement at or beyond one year to demonstrate satisfactory to excellent performance. Methods. The initial consecutive series of 100 robotic total knee replacements using a semi-active haptic guided system including 34 from the initial IDE series in 2014 and those performed after commercial approval beginning in 2016 were reviewed. Pre- operative planning utilizing CT determined the implant placement and boundaries and thus the limit of excursion from any part of the end effector saw tip. Self-retaining retractors were also utilized. Operative reports, 2, 6, and 12 week, and yearly follow-up visit reports were reviewed for any evidence of inadvertent injury to the medial collateral ligament, patellar tendon, or a neurovascular structure from the cutting tool. Operative notes were also reviewed to determine if the robotic procedure was partially or completely aborted due to any issue. Knee Society and Functional scores were recorded from pre-operative and yearly. Results. No cases were unable to be completed robotically. No case had evidence for acute or delayed injury to the medial collateral ligament, patellar tendon, or neurovascular structure. The average follow-up for this series was 1.54 years. Average pre- operative Knee Society and Functional Scores improved from 44.7 and 50 to 98.1 and 87.8 at one year follow-up, 93.8 and 83.1 at two year follow-up, 98.5 and 87.7 at three year follow-up, and 99 and 85 at four year follow-up. Conclusions. A semi-active haptic guided robotic system is a safe and reliable method to perform total knee replacement surgery. Preliminary short-term outcomes data shows excellent clinical and functional results

Femoroacetabular impingement (FAI) is a condition of the hip where there is a mismatch of the femoral head and hip acetabulum. This mismatch creates abnormal contact between the bones and causes hip pain which can lead to damage, and eventually osteoarthritis of the hip. The diagnosis and treatment of FAI has become one of the most popular clinical scenarios in orthopaedic surgery, with hip arthroscopy procedures increasing exponentially over the past five years. Surgical intervention usually involves correcting the existing deformities by reshaping the ball and socket (“osteoplasty” or “rim trimming”) so that they fit together more easily while repairing any other existing soft tissue damage in the hip joint (e.g. labral repair). Although correction of the misshaped bony anatomy and associated intra-articular soft tissue damage of the hip is thought to appease impingement and improve pain and function, the current evidence is based on small, observational, and low quality studies. A lack of definitive evidence regarding the efficacy of osteochondroplasty in treating FAI fueled the design and execution of the FIRST randomized controlled trial (RCT). FIRST evaluated the impact of surgical correction of the hip impingement morphology with arthroscopic osteochondroplasty versus arthroscopic lavage on pain, function, and quality of life in adults aged 18–50 years diagnosed with non-arthritic FAI at one year. FIRST was a large definitive RCT (NCT01623843) enrolling patients with FAI requiring surgical intervention across 11 international clinical sites. Participants were randomized to either arthroscopic osteochondroplasty (shaving of bone) or lavage (washing the joint of painful inflammation debris). The primary outcome was patient-reported pain within one year of the initial surgery measured using the Visual Analogue Scale (VAS). Secondary outcomes included function, health utility, and health-related quality of life using several general and hip-centric health questionnaires. An independent, blinded adjudication committee evaluated the quality of surgery, re-operations, and other patient complications. Patients and data analysts were blinded to the treatment groups. Two-hundred and twenty participants were enrolled into the FIRST trial over a six-year period (pilot phase: N=50, from 2012–2013 and definitive phase: N=170, from 2015–2018) at 11 clinical sites in Canada, Finland, and Denmark. The FIRST results will be released at the ISAKOS annual meeting as follows. The absolute difference in rate of pain reduction between groups was XX (95% CI: YY-YY, p=X). The mean differences of the Short-Form 12 (SF-12, MCS and PCS), Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and EuroQol 5-Dimensions (EQ-5D) between groups are XX (95% CI: YY-YY, p=X)…, respectively. Reoperations occurred in XX of 220 (X%) patients over the one-year follow up period (OR:XX, 95% CI: YY-YY, p=X) and the patients treated with arthroscopic osteochondroplasty conferred the following risk of reoperation within one-year compared to arthroscopic lavage (RR:XX, 95% CI: YY-YY, p=X). This RCT represents major international efforts to definitively identify the optimal treatment strategy for FAI. The results of this trial will change practice, being used to prevent chronic hip pain and loss of function caused by hip osteoarthritis

Introduction. Pilon fractures are complex, high-energy, intra-articular fractures of the distal tibia. Achieving good outcomes is challenging due to fracture complexity and extensive soft tissue damage. The purpose of this study was to determine the long-term functional and clinical outcomes of definitive management with fine wire Ilizarov fixation for closed pilon fractures. Materials and Methods. 185 patients treated over a 14-year period (2004–2018) were included. All patients had Ilizarov frames applied to restore mechanical axis and fine wires to control periarticular fragments. CT scans were performed post operatively to confirm satisfactory restoration of the articular surface. All frames were dynamized prior to removal. Patients' functional outcome was assessed using the validated Chertsey Outcome Score for Trauma (“COST”). Review of clinical notes and imaging was used to determine complications and time to union. Results. The mean functional outcome in the studied cohort was determined to be “average” on the “COST” score. Poorer functional outcomes were associated with younger age at time of injury and multi-fragment fracture patterns. Mean time in frame was 170 days. Complication rates were low. There were no deep infections, no amputations and only 8 patients went on to have ankle fusions. Conclusions. Good functional results and low complication rates can be achieved by managing pilon fractures with fine wire Ilizarov fixation. Nonetheless, at time of injury patients should be counselled as to the severity of the injury and impact on their functional status

Background. Conventional instrumented total knee arthroplasty uses fixed angles for bony cuts followed by soft tissue releases to achieve balance. Robotic-assisted surgery allows for soft tissue balancing first then bony resection. The changes to the implant position from conventional instrumented surgery were measured and recorded. Methods. A single center, retrospective study reviewed consecutive total knee replacement surgeries over a 12 month period utilizing robotic pre-planning and balancing techniques. Changes to femoral and tibial varus/valgus and femoral rotation from traditional instrumented surgery positions were analyzed. Results. There were 145 knees which were grouped by preoperative deformity and the changes were frequent (94%), variable for any given deformity, and often unpredictable. Staged bilateral total knee arthroplasty patients also showed variability between knees. Conclusion. Robotic-assisted knee replacement technology not only has the advantage of navigation with regard to accurate implant positioning but also provides real-time, actionable data to better position the implant prior to bone resection and minimize soft tissue damage

Since its approval by the FDA two decades ago, Negative Pressure Wound Therapy (NPWT) has become a valuable asset in the management of open fractures with significant soft tissue damage as those seen in high velocity gunshot injuries. These lesions are often associated with grossly contaminated wounds and require a prompt and effective approach. Wound dehiscence and surgical site infection are two of the most common post-operative complications, with poor results when treated with standard gauze dresses. NPTW comes as a legitimate resource promoting secondary intention healing through increased granulation and improved tissue perfusion, as well as continuous local wound drainage preventing bacterial growth and further infection. Recent evidence-based guidelines are still limited for use of NPWT in the treatment of Gustilo-Anderson type IIIB open fractures and there are few cases in literature reporting the management of upper extremity injuries. We present and discuss a successful case of a type IIIB open humeral fracture wound treated with NPWT. A 38-years-old male was admitted to the Emergency Room with a type IIIB open humeral fracture as a result of a gunshot with extensive soft tissue damage. IV antibiotic therapy was promptly started followed by surgical stabilization by intramedullary nailing with primary wound closure. The patient presented an early surgical site infection with wound dehiscence requiring secondary debridement with poor subsequent healing and deficient soft tissue coverage. After ineffective 28 days of standard gauze dresses we started NPWT. NPTW was applied using foam coverage over the dehiscence area with visible results after 13 days and complete granulation of the skin defect by the 28th day. The wound healed completely after 14 weeks of NPWT. The fracture evolved into a painless pseudarthrosis revealing an excellent functional recovery and an acceptable aesthetic result. NPTW is a valuable, effective, and well tolerated resource in the treatment of open fractures with extensive soft tissue damage such as Gustilo-Anderson type IIIB fractures. It should be considered not just as a salvage procedure but as well as a primary option especially in grossly contaminated wounds. No benefits in any form have been received from a commercial party

Aim. The reconstruction of bone critical size defects of the tibia is one of the most complex therapeutic challenges in the orthopedic field. This study aims to describe and evaluate our three-staged surgical protocol of reconstruction of infected defects of the tibia emphasizing in limb salvage rate, resolution of infection, functional outcome and patient satisfaction. Method. A retrospective review was performed in all cases of complex infected tibia fracture with combined soft and bone tissue loss treated in a specialized limb reconstruction center between 2010 and 2018. In all cases, a three-stage protocol was performed: 1) Infected-limb damage control with radical debridement, 2) Soft tissue coverage with vascularized or local flap 3) Bone reconstruction procedure. The minimum follow-up required was 12 months after external fixator removal. Results. Twenty-eight patients with a mean age of 42 years were included. The mean soft tissue defect was 91.7 cm2 and the mean bone defect was 5.8 cm. 67.85% of the cases were classified as a type IV B-local osteomyelitis. The median global treatment time was 456 days. The External Fixator Time (EFT) was 419, 284, 235 for bone transport, shortening-lengthening and acute shortening groups respectively. The median Bone Healing Index (BHI) was 1.82 months/cm in bone transport group and 2.15 months/cm in shortening-lengthening group. The limb salvage rate was 92.85%. Infection resolution rate was 96,42%. We achieved bone union in 92,85% of the cases. Regarding ASAMI bone score, 92.8% of the cases were “good-or-excellent”. Two patients underwent a delayed amputation. Eight cases of non-progressive Docking Site (DS) healing were observed. Nineteen non-expected reinterventions were performed. Functional data: the mean VAS score was 1.0. The mean LEFS score was 55.88 (55.88/80). Regarding ASAMI functional score, 78,6% of the cases were “good-or-excellent”. More than 80% of the patients could return to work. 100% of the patients were “very satisfied” or “moderately satisfied” (75% and 25% respectively). Conclusions. Our results demonstrate that our three-stage surgical approach in infected tibial bone defects with soft tissue damage can result in high infection resolution, good functional outcome, good patient satisfaction and an acceptable limb salvage rate despite the large time of treatment and unexpected reinterventions

Introduction. Total knee arthroplasty (TKA) is associated with significant blood loss, for which blood transfusion might be necessary. The role of the tourniquet is controversial, though it is widely used by orthopedic surgeons. Its use was believed to be effective in decreasing intraoperative blood loss and creating a bloodless surgical field, which theoretically would facilitate the cementing technique and other surgical procedures. However, reactive blood flow reached its peak within five minutes after the tourniquet had been released. The tourniquet controls intraoperative blood loss, but cannot stop postoperative blood loss. Patients who were managed with a tourniquet during the operation often complained of thigh pain. This was possibly caused by the direct pressure of an inflated tourniquet on the nerves and local soft tissues. Limb swelling and increased soft tissue tension caused by reactive hyperperfusion after tourniquet deflation may also contribute to the wound pain. The aim of our study is to investigate the effect of tourniquet on blood loss and soft tissue damage in TKA. Materials & Methods. In this prospective, randomized study, 72 patients with primary cemented knee arthroplasty were randomly allocated to two groups (with and without tourniquet). The operation time, blood loss, post-operative hemoglobin, hematocrit, markers of soft tissue damage (myoglobin, Cretine Posphokinase(CK), LDH, GOT, Creatinine), status of rehabilitation, knee pain and thigh pain were monitored until discharge. Results. The intra-operative and total blood loss is more in non-tourniquet. The post-operative levels of hemoglobin and hematocrit were significant higher in tourniquet group until postoperative day 4. Using tourniquet also shortened the operation time. Patients managed without tourniquet showed higher CK level in postoperative day 2. The severity of knee pain was similar in both group. Mild thigh pain was noted in tourniquet group. Conclusions. Our randomized controlled trial revealed that the usage od tourniquet in TKA may save blood and save time with minor adverse effect. Without using tourniquet, the prolonged surgical time and excessive hemostasis may cause more soft tissue damage

Introduction. Adverse reaction to metal debris (ARMD) is an increasingly recognised complication of metal-on-metal hip arthroplasty. A previous study described poor results following revision and recommended early intervention. 1. We determined the outcome of revision for ARMD and present the largest case series to date. Methods. Between 2005 and 2010, 98 patients (101 hips) underwent revision for ARMD. The diagnosis of ARMD was based on clinical history, examination, appearance at revision and histology. Patients were reviewed at 3, 6 and 12 months and annually thereafter. Patient satisfaction, Harris hip scores (HHS) and metal ions were analysed. Results. 54 patients (55 hips) with an average age of 58 years (29 to 81 years) completed minimum one year follow-up (range 1 to 5 years). The mean HHS improved from 49.7 (10 to 79) to 86.3 (40 to 100). Forty-five (81%) patients were satisfied and nine (16%) patients were not satisfied with the outcome. The mean serum cobalt 24.5 (1.65 to 96.6) improved to 1.17 (0.31 to 6.99). Two patients died from unrelated diseases. There were 8 (14%) dislocations and one (1.8%) sciatic nerve palsy that has not recovered. Eight (14%) patients needed re-revision (dislocation: 5 and pain: 3). 26 % had severe soft tissue damage. Six patients have persistent pain and four had recurrent effusions. There were no dislocations in the most recent 50 cases. Discussion. Treatment of ARMD is technically demanding because extensive soft tissue damage can compromise stability. Early results in the current study were promising. Early intervention reduced the dislocation rate and appeared to have a positive impact on outcome. A small group of patients may have persistent pain and recurrent effusions that may require re-revision

Introduction. While manual total knee arthroplasty (MTKA) procedures have demonstrated excellent clinical success, occasionally intraoperative damage to soft tissues can occur. Robotic-arm assisted technology is designed to constrain a sawblade in a haptic zone to help ensure that only the desired bone cuts are made. The objective of this cadaver study was to quantify the extent of soft tissue damage sustained during TKA through a robotic-arm assisted (RATKA) haptically guided approach and conventional MTKA approach. Methods. Four surgeons each prepared six cadaveric legs for CR TKA: 3 MTKA and 3 RATKA, for a total of 12 RATKA and 12 MTKA knees. With the assistance of an arthroscope, two independent surgeons graded the damage of 14 knee structures: dMCL, sMCL, posterior oblique ligament (POL), semi-membranosus muscle tendon (SMT), gastrocnemius muscle medial head (GMM), PCL, ITB, lateral retinacular (LR), LCL, popliteus tendon, gastrocnemius muscle lateral head (GML), patellar ligament, quadriceps tendon (QT), and extensor mechanism (EM). Damage was defined as tissue fibers that were visibly torn, cut, frayed, or macerated. Percent damage was averaged between evaluators, and grades were assigned: Grade 1) complete soft tissue preservation to ≤5% damage; Grade 2) 6 to 25% damage; Grade 3) 26 to 75% damage; and Grade 4) 76 to 100% damage. A Wilcoxon Signed Rank Test was used for statistical comparisons. A p-value <0.05 was considered statistically significant. Results. Significantly less damage occurred to the PCL in the RATKA than the MTKA specimens (p=0.004). RATKA specimens had less damage to the dMCL (p=0.186), ITB (p=0.5), popliteus (p=0.137), and patellar ligament (p=0.5). The sMCL, POL, SMT, GMM, GML, LR, LCL, QT, and EM were grade 1 in all MTKA and RATKA specimens. No intentional soft tissue releases were performed in either group to balance the knee. Discussion/Conclusion. The results of this study indicate that RATKA may result in less soft-tissue damage than MTKA, especially to the posterior cruciate ligament. This finding can potentially be attributed to RATKA using a haptic boundary to constrain the sawblade, which can help prevent unwanted soft-tissue damage. However, since any damage was post-operatively assessed and in a cadaveric model, further investigations on soft-tissue damage from patients with clinical outcomes should be performed