Reliability of pre-resection ligament tension assessment in imageless robotic assisted total knee replacement.

BACKGROUND: Ligament tension balance is a major determinant for the success of total knee replacement (TKR). The present study aimed at determining the inter-rater and intra-rater reliability in performing ligament tension assessment using an imageless robotic-assisted TKR. METHODS: Twenty-four knees in 21 patients who received robotic-assisted TKR for end-stage varus osteoarthritis were examined. Three orthopedic specialists and six orthopedic trainees participated in the operations. Data from the ligament tension assessment were collected during the operations. RESULTS: For the inter-rater reliability, "extension medial" and "flexion medial" had excellent reliability whilst "extension lateral" and "flexion lateral" had good-to-excellent reliability. For the intra-rater reliability, "extension medial" showed excellent reliability, "extension lateral" and "flexion medial" showed good-to-excellent reliability, and "flexion lateral" showed moderate-to-excellent reliability. CONCLUSIONS: Robotic-assisted technology provides a reliable solution to improve ligament tension assessment. All ligament tension assessments with the use of the technology could demonstrate at least good-to-excellent reliability except for the intra-rater reliability of "flexion lateral".

Application of image recognition-based tracker-less augmented reality navigation system in a series of sawbone trials.

BACKGROUND: This study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage. METHODS: The AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia's feature detection algorithm. RESULTS: In trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min). CONCLUSIONS: The AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

Skilled reaching test for shoulder function assessment in a rat model of rotator cuff tear: a pilot study.

BACKGROUND: Functional assessments are crucial to evaluate treatment outcomes in clinical and animal studies on rotator cuff injuries. While gait analysis is commonly used to assess animal models of rotator cuff tears, it is less relevant for human patients as the human shoulder is typically assessed in a non-weight-bearing condition. The present study introduces the skilled reaching test as a shoulder functional assessment tool for rats, which allows for evaluation without weight bearing. METHODS: In the control group, 8 male Sprague-Dawley rats received rotator cuff tear surgery without repair. In the rotator cuff repair group, 20 rats received rotator cuff repair at 4 weeks post rotator cuff tear. For the skilled reaching test, rats were trained to extend their forelimbs to fetch food pellets, and the number of trials, number of attempts and the success rate were recorded. The gait analysis and skilled reaching test were performed at baseline, 4 weeks post-tear, 1, 2, 4, and 8 weeks post-repair. The repeated measures analysis of variance was used to evaluate the effects of time on the shoulder function. The significance level was set at 0.05. RESULTS: The skilled reaching test required 216 h to conduct, while the gait analysis took 44 h. In the rotator cuff repair group, gait performance significantly deteriorated at 1 week post-repair and restored to 4 weeks post-tear levels at 4 weeks post-repair. Regarding the skilled reaching test, the number of attempts, number of trials and the success rate decreased at 1 week post-repair. Subsequently, there was a brief rebound in performance observed at 2 weeks post-repair, followed by a continued decline in the number of attempts and trials. By 8 weeks post-repair, only the success rate had restored to levels similar to those observed at 4 weeks post-tear. CONCLUSION: The skilled reaching test can detect functional deficiencies following rotator cuff tear and repair, while it requires high time and labour costs.

Comparison of the in vivo kinematics between robotic-assisted Bi-cruciate retaining and Bi-cruciate stabilised total knee arthroplasty.

BACKGROUND: Up to 20% of patients remain unsatisfied after total knee arthroplasty (TKA), prompting the development of new implants. Bi-Cruciate Retaining (BCR) TKA preserves both the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), with the ACL beneficial for its proprioceptive qualities. The Bi-Cruciate Stabilised (BCS) TKA substitutes the ACL and PCL with a unique dual cam-post mechanism. Robotics improve accuracy and facilitate technically demanding TKA. METHODS: This was a retrospective case-control study recruited from two centres. Measured outcomes included kinematic analysis, proprioception, and functional outcomes. RESULTS: There was a significantly larger maximum flexion angle and range of flexion to extension in sit-to-stand and stairs in BCR when compared to BCS. Further analysis revealed more similarities between BCR and normal native knees. Proprioception and functional scores did not have any statistical difference. CONCLUSION: BCR TKA demonstrated better knee flexion in weight-bearing active range of motion and showed similarities with normal knee kinematics.

Vitamin D as an intervention for improving quadriceps muscle strength in patients after anterior cruciate ligament reconstruction: study protocol for a randomized double-blinded, placebo-controlled clinical trial.

BACKGROUND: The goal of anterior cruciate ligament reconstruction (ACLR) is to restore the preinjury level of knee function to return to play (RTP). However, even after completing the rehabilitation programme, some patients may have persistent quadriceps muscle weakness affecting knee function which ultimately leads to a failure in returning to play. Vitamin D has been long recognized for its musculoskeletal effects. Vitamin D deficiency may impair muscle strength recovery after ACLR. Correcting vitamin D levels may improve muscle strength. METHODS: This is a double-blinded, randomized controlled trial to investigate the effects of vitamin D supplementation during the post-operative period on quadriceps muscle strength in anterior cruciate ligament (ACL)-injured patients. Patients aged 18-50 with serum vitamin D < 20 ng/ml, unilateral ACL injury, > 90% deficit in total quadriceps muscle volume on the involved leg compared with uninvolved leg, Tegner score 7 + , and no previous knee injury/surgery will be recruited. To assess patient improvement, we will perform isokinetic and isometric muscle assessments, ultrasound imaging for quadriceps thickness, self-reported outcomes, KT-1000 for knee laxity, biomechanical analysis, and Xtreme CT for bone mineral density. To investigate the effect of vitamin D status on quadriceps strength, blood serum samples will be taken before and after intervention. DISCUSSION: Patients with low vitamin D levels had greater quadriceps fibre cross-sectional area loss and impaired muscle strength recovery after ACL. The proposed study will provide scientific support for using vitamin D supplementation to improve quadriceps strength recovery after ACLR. TRIAL REGISTRATION: ClinicalTrials.gov NCT05174611. Registered on 28 November 2021.

Reconsidering "Critical" Bone Loss in Shoulder Instability: 17-Year Follow-Up Study following Arthroscopic Bankart Repair.

Background: Glenoid bone loss is a risk factor leading to the failure of arthroscopic Bankart repair. While 20-25% glenoid bone loss has long been considered the level to necessitate bony augmentation, recent studies indicate that 13.5% has a "subcritical" glenoid bone loss level, which is associated with decreased short- and medium-term functional scores. Few researchers worked on the long-term effect of "subcritical" or even less severe degrees of glenoid bone loss on redislocation rates and functional outcomes after arthroscopic Bankart repair. This study aimed to evaluate the effect of subcritical or less severe glenoid bone loss on redislocation rates and function after arthroscopic Bankart repair. Methods: A patient cohort who had undergone computed tomography (CT) of glenoid bone loss and arthroscopic Bankart repair over 15 years ago was reviewed. Western Ontario Shoulder Instability (WOSI) score, Single Assessment Numeric Evaluation (SANE) score, redislocation after operation, mechanism of recurrence, and revision details were reviewed. Results: Seventy-five patients were reassessed 17.6 ± 1.9 years following initial surgery. The age at enrolment was 26.8 ± 8.3 years. Twenty-two (29%) patients of the 75 patients had a redislocation on long-term follow-up, though this was not related to glenoid bone loss severity. The impaired functional score was found in patients with initial glenoid bone loss of 7% or more on long-term follow-up: WOSI (physical symptoms): 0.98 ± 2.00 vs 2.25 ± 4.01, p=0.04 and WOSI (total): 0.79 ± 1.43 vs 1.88 ± 3.56, p=0.04. Conclusions: At a mean of 17.5 years following arthroscopic Bankart repair, redislocation occurs in over a quarter of 75 patients, and they are not related to initial glenoid bone loss severity. Impaired functional outcome is apparent in patients with initial glenoid bone loss of >7%, though this impairment does not seem sufficiently severe to warrant an alternative treatment approach.

Surgical accuracy of image-free versus image-based robotic-assisted total knee arthroplasty.

BACKGROUND: This study investigated the accuracy in achieving proper lower limb alignment and component positions after total knee replacement (TKR) with image-free and image-based robotic-assisted TKR. METHODS: A total of 129 patients (166 knees) suffering from end-stage knee arthritis who underwent TKA operated by robotic-assisted surgery between the years 2018 and mid-2021 were recruited. Radiological outcomes were compared between image-free and image-based robotic-assisted surgical systems. RESULTS: There were significant differences between the two robotic systems when comparing the mean planned component alignment and the mean measured alignment on radiographs, in which the image-free robotic-assisted system was more varus, whereas the image-based robotic-assisted system was more valgus for both the mean femoral and tibial component coronal alignment (p < 0.001). For tibial component sagittal alignment, the image-based group had a larger deviation from the planned posterior slope (p < 0.001). CONCLUSION: Image-free and image-based robotic assisted TKR had differing accuracy in femoral and tibial alignment.

Surgical accuracy and clinical outcomes of image-free robotic-assisted total knee arthroplasty.

BACKGROUND: The development of total knee arthroplasty (TKA) for knee osteoarthritis (OA) has a good reputation for its effectiveness in reducing joint pain and improving range of motion. We aimed to review our early results using the image-free robotic-assisted technology in knee arthroplasty. METHODS: A total of 71 patients suffering from end-stage OA knee receiving TKA operated by robotic-assisted surgery between the years 2018 and mid-2021 were recruited. Clinical and radiological outcomes were compared with age and sex-matched control group (conventional TKA). RESULTS: The radiological outcome showed significantly more postoperative lower limb alignment outliers in conventional side than robotic-assisted sides. Postoperative knee scores were similar among both groups. Robotic-assisted TKA required a longer implantation time but a shorter hospital stay. CONCLUSION: Robotic-assisted TKA achieved a lower rate of mechanical axis Outlier in the coronal and sagittal plane with a shorter hospital stay. Yet both methods achieve a similar functional outcome.

Bioactive Decellularized Tendon-Derived Stem Cell Sheet for Promoting Graft Healing After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Stem cell sheets provide a scaffold-free option for the promotion of graft healing after anterior cruciate ligament reconstruction (ACLR). However, cell viability, stability, and potential uncontrolled actions create challenges for clinical translation. The decellularization of cell sheets may overcome these problems as studies have shown that the natural extracellular matrix of stem cells is bioactive and can promote tissue repair. HYPOTHESIS: The decellularized tendon-derived stem cell (dTDSC) sheet can promote graft healing after ACLR. STUDY DESIGN: Controlled laboratory study. METHODS: An optimized decellularization protocol was developed to decellularize the TDSC sheets. A total of 64 Sprague-Dawley rats underwent ACLR with or without the dTDSC sheet wrapping the tendon graft (n = 32/group). At 2 and 6 weeks after surgery, graft healing was assessed by micro-computed tomography, histology, and biomechanical testing. The accumulation of iNOS+ and CD206+ cells and the expression of metalloproteinase 1 (MMP-1), MMP-13, and tissue inhibitor of metalloprotease 1 (TIMP-1) were assessed by immunohistochemistry. RESULTS: The decellularization was successful, with the removal of 98.4% nucleic acid while preserving the collagenous proteins and bioactive factors. The expression of bone morphogenetic protein 2 (BMP-2) and VEGF in the dTDSC sheet was comparable with the TDSC sheet (P > .05). Micro-computed tomography showed significantly more tunnel bone formation in the dTDSC sheet group. The dTDSC sheet group demonstrated better graft osteointegration and higher integrity of graft midsubstance with significantly higher ultimate failure load (16.58 ± 7.24 vs 8.93 ± 2.45 N; P = .002) and stiffness (11.97 ± 5.21 vs 6.73 ± 2.20 N/mm; P = .027). Significantly fewer iNOS+ cells but more CD206+ cells, as well as lower MMP-1 and MMP-13 but higher TIMP-1 expression, were detected at the tendon-bone interface and graft midsubstance in the dTDSC sheet group. CONCLUSION: An optimized decellularization protocol for producing bioactive dTDSC sheets was developed. Wrapping tendon graft with a dTDSC sheet promoted graft healing after ACLR, likely via enhancing bone formation and angiogenesis by BMP-2 and VEGF, modulating macrophage polarization and MMP/TIMP expression, and physically protecting the tendon graft. CLINICAL RELEVANCE: dTDSC sheets alleviate the quality control and safety concerns of cell transplantation and can be used as a cell-free alternative for the promotion of graft healing in ACLR.

Effect of pulsed electromagnetic field as an intervention for patients with quadriceps weakness after anterior cruciate ligament reconstruction: a double-blinded, randomized-controlled trial.

BACKGROUND: The ultimate goal of anterior cruciate ligament reconstructions (ACLR) is to fulfil the return-to-play (RTP) criteria. Quadriceps muscle strength is one of the key determinants for a patient's successful return-to-play after ACLR. Quadriceps muscle atrophy can persist beyond the completion of the rehabilitation program in almost half the patients and the reason behind this is still unknown. There are emerging evidences showing that pulsed electromagnetic field (PEMF) can modulate mitochondrial activities for muscle gain. PEMF exposure on top of regular exercise training may promote muscle regeneration and tissue healing. METHODS: This is a double-blinded, randomized controlled trial to investigate the effects of PEMF treatment during the postoperative period on quadriceps muscle strength in ACL injured patient. Adult patients (aged 18-30) with a unilateral ACL injury, total quadriceps muscle volume is equal or more than 7% deficit on involved leg compared with uninvolved leg, sporting injury with a Tegner score of 7+, and both knees without a history of injury/prior surgery will be recruited. To estimate the improvement of patients, isokinetic muscle assessment, ultrasound imaging and MRI for quadriceps muscle thickness, self-reported outcomes with questionnaires, KT-1000 for knee laxity and biomechanical analysis, and Xtreme CT for bone mineral density will be performed. To investigate the mechanism of PEMF therapy on increasing quadriceps strength, samples of blood serum will be drawn before and after intervention. DISCUSSION: This is the first trial evaluating the effects of PEMF on quadriceps muscle recovery after ACLR. The proposed study addresses a huge research gap by evaluating practical use of PEMF as part of rehabilitation. The proposed study will provide much needed scientific support in the use of this noninvasive treatment modality to facilitate recovery of quadriceps strength after PEMF. TRIAL REGISTRATION: ClinicalTrials.gov NCT05184023. Registered on 5 January 2022.

Large lateral tibial slope and lateral-to-medial slope difference are risk factors for poorer clinical outcomes after posterolateral meniscus root tear repair in anterior cruciate ligament reconstruction.

BACKGROUND: Meniscus root tear is an uncommon but detrimental injury of the knee. Hoop stress is lost during meniscus root tear, which can lead to excessive tibiofemoral contact pressure and early development of osteoarthritis. Posterolateral meniscus root tears (PLRT) are more commonly associated with anterior cruciate ligament (ACL) tears. As the lateral compartment is less congruent than the medial compartment, it is more susceptible to a shearing force, which is increased in the ACL-deficient knee. In accordance with the compressive axial load, the increase in the tibial slope would generate a greater shearing force. The additional lateral compartment mobility caused by ACL tear should be reduced after ACL reconstruction (ACLR). However, there is a lack of evidence to conclude that ACLR can sufficiently limit the effect of large tibial slope (LTS) on the healing after PLRT repair. This study aimed to evaluate whether a steep LTS would be a risk factor for poorer clinical outcomes after PLRT repair concomitant with ACLR. METHODS: In this retrospective study, a chart review was conducted to identify patients with concomitant unilateral primary ACLR and PLRT repair. Patients with a partial tear or healed tear were excluded. Postoperative MRI and clinical assessments were performed at a mean follow up of 35 months. MRI data was used to measure the LTS, medial tibial slope (MTS), coronal tibial slope (CTS), the lateral-to-medial slope difference (LTS-MTS) and meniscus healing and extrusion. Functional outcomes were evaluated by patient-reported outcomes (International Knee Documentation Committee [IKDC], Lysholm and Tegner scores) and KT-1000 arthrometer assessment. Interobserver reproducibility was assessed by two reviewers. RESULTS: Twenty-five patients were identified for the analysis. Patients with larger LTS and larger LTS-MTS differences were shown to be correlated with poorer IKDC scores after surgery (R = -0.472, p = 0.017 and R = -0.429, p = 0.032, respectively). Herein, patients with LTS ≥ 6° or LTS-MTS ≥ 3° demonstrated poorer IKDC scores. CONCLUSION: A large LTS (≥ 6°) and a large difference of LTS-MTS (≥ 3°) were shown to be risk factors for poorer functional and radiological outcomes for PLRT repair in patients after ACLR. Clinically, closer monitoring and a more stringent rehabilitation plan for patients with LTS ≥ 6° or LTS-MTS ≥ 3° would be recommended.

3D printing in orthopaedic surgery: a scoping review of randomized controlled trials.

AIMS: The use of 3D printing has become increasingly popular and has been widely used in orthopaedic surgery. There has been a trend towards an increasing number of publications in this field, but existing literature incorporates limited high-quality studies, and there is a lack of reports on outcomes. The aim of this study was to perform a scoping review with Level I evidence on the application and effectiveness of 3D printing. METHODS: A literature search was performed in PubMed, Embase, and Web of Science databases. The keywords used for the search criteria were ((3d print*) OR (rapid prototyp*) OR (additive manufactur*)) AND (orthopaedic). The inclusion criteria were: 1) use of 3D printing in orthopaedics, 2) randomized controlled trials, and 3) studies with participants/patients. Risk of bias was assessed with Cochrane Collaboration Tool and PEDro Score. Pooled analysis was performed. RESULTS: Overall, 21 studies were included in our study with a pooled total of 932 participants. Pooled analysis showed that operating time (p < 0.001), blood loss (p < 0.001), fluoroscopy times (p < 0.001), bone union time (p < 0.001), pain (p = 0.040), accuracy (p < 0.001), and functional scores (p < 0.001) were significantly improved with 3D printing compared to the control group. There were no significant differences in complications. CONCLUSION: 3D printing is a rapidly developing field in orthopaedics. Our findings show that 3D printing is advantageous in terms of operating time, blood loss, fluoroscopy times, bone union time, pain, accuracy, and function. The use of 3D printing did not increase the risk of complications. Cite this article: Bone Joint Res 2021;10(12):807-819.

Posterior Tibial Loading Results in Significant Increase of Peak Contact Pressure in the Patellofemoral Joint During Anterior Cruciate Ligament Reconstruction: A Cadaveric Study.

BACKGROUND: Inappropriate posterior tibial loading and initial graft tension during anterior cruciate ligament (ACL) reconstruction may cause altered patellofemoral joint (PFJ) contact mechanics, potentially resulting in pain and joint degeneration. HYPOTHESIS: PFJ contact pressure would increase with the increases in posterior tibial loading and graft tension during ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Nine fresh-frozen, nonpaired human cadaveric knees were tested in a customized jig from 0° to 120° of knee flexion. First, the knee was tested in the ACL-intact state. Second, reconstruction of the ACLs using different posterior tibial loadings and graft tensions were performed. The posterior tibial loading was evaluated at 2 levels: 33.5 and 67 N. Graft tension was assessed at 3 levels: low tension (20 N), medium tension (60 N), and high tension (80 N). Maximum values of peak contact pressure in the medial and lateral patellar facets were compared between ACL-intact and ACL-reconstructed knees. The PFJ kinematics between ACL-intact knees and ACL-reconstructed knees were compared during knee flexion at 30°, 60°, 90°, and 120°. RESULTS: Reconstruction of ACLs with both low and high posterior tibial loading resulted in significant increases of peak contact pressure in the medial (range of differences, 0.46-0.92 MPa; P < .05) and lateral (range of differences, 0.51-0.83 MPa; P < .05) PFJ compared with the ACL-intact condition. However, no significant differences in PFJ kinematics were identified between ACL-reconstructed knees and ACL-intact knees. In ACL-reconstructed knees, it was found that a high posterior tibial loading resulted in high peak contact pressure on the medial patellar side (range of differences, 0.37-0.46 MPa; P < .05). No significant difference in peak contact pressure was observed among the differing graft tensions. CONCLUSION: In this cadaveric model, ACL reconstruction resulted in significant increases of peak contact pressure in the PFJ facet when compared with the ACL-intact condition. A high posterior tibial loading can lead to high medial PFJ peak contact pressure. Graft tension was found to not significantly affect PFJ contact pressure during ACL reconstruction. CLINICAL RELEVANCE: An excessive posterior tibial loading during ACL reconstruction resulted in increased PFJ contact pressures at time of surgery. These data suggest that a low posterior tibial loading might be preferred during ACL reconstruction surgery to reduce the PFJ contact pressure close to that of the ACL-intact condition.

Tibial cutting guide (resector) holding pins position and subsequent risks of periprosthetic fracture in unicompartmental knee arthroplasty: a finite element analysis study.

BACKGROUND: Periprosthetic fracture of the tibia after unicompartmental knee arthroplasty has been reported to be associated with excessive pin holes created for stabilization of the cutting guide. However, fractures have also been reported in cases using two pins as in the method suggested by the manufacturer. It is currently unclear whether variations in pinhole positions make a difference in proximal tibial fracture risk. METHODS: Finite element models were constructed using Chinese female bone computed tomography images, with bone cuts made according to the surgical steps of implanting a fixed bearing unicompartmental arthroplasty. Four combinations of pinholes (pins placed more closely to the medial tibial cortex or centrally along the mechanical axis as allowed by the tibial cutting guide) created for tibial cutting guide placement were tested by finite element analyses. Testing loads were applied for simulating standing postures. The maximum von Mises stress on the tibial plateau was evaluated. RESULTS: Pinhole placed close to the medial edge of the proximal tibial plateau is associated with the highest stress (27.67 Mpa) and is more likely to result in medial tibial fracture. On the contrary, pinhole placed along the central axis near the tibial tuberosity has the lowest stress (1.71 Mpa) and reflects lower risk of fracture. CONCLUSION: The present study revealed that placing tibial cutting guide holding pins centrally would lower the risks of periprosthetic fracture of the medial tibial plateau by analyzing the associated stress in various pin hole positions using finite element analysis.

Patient-specific instrumentation (PSI) Referencing High Tibial Osteotomy Technological Transfer and Education: protocol for a double-blind, randomised controlled trial (PROTECTED HTO Trial).

INTRODUCTION: High tibial osteotomy (HTO) is a treatment of choice for active adult with knee osteoarthritis. With advancement in CT imaging with three-dimensional (3D) model reconstruction, virtual planning and 3D printing, patient-specific instrumentation (PSI) in form of cutting jigs is employed to improve surgical accuracy and outcome of HTO. The aim of this randomised controlled trial (RCT) is to explore the surgical outcomes of HTO for the treatment of medial compartment knee osteoarthritis with or without a 3D printed patient-specific jig. METHODS AND ANALYSIS: A double-blind RCT will be conducted with patients and outcome assessors blinded to treatment allocation. This meant that neither the patients nor the outcome assessors would know the actual treatment allocated during the trial. Thirty-six patients with symptomatic medial compartment knee osteoarthritis fulfilling our inclusion criteria will be invited to participate the study. Participants will be randomly allocated to one of two groups (1:1 ratio): operation with 3D printed patient-specific jig or operation without jig. Measurements will be taken before surgery (baseline) and at postoperatively (6, 12 and 24 months). The primary outcome includes radiological accuracy of osteotomy. Secondary outcomes include a change in knee function from baseline to postoperatively as measured by three questionnaires: Knee Society Scores (Knee Scores and Functional Scores), Oxford Knee Scores and pain visual analogue scale (VAS) score. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Joint Chinese University of Hong Kong - New Territories East Cluster Clinical Research Ethics Committee (CREC no. 2019.050), in accordance with the Declaration of Helsinki. The results will be presented at international scientific meetings and through publications in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04000672; Pre-results.

Multi-energy spectral photon-counting computed tomography (MARS) for detection of arthroplasty implant failure.

To determine whether state-of-the-art multi-energy spectral photon-counting computed tomography (MARS) can detect knee arthroplasty implant failure not detected by standard pre-operative imaging techniques. A total knee arthroplasty (TKA) removed from a patient was reviewed. The extracted prosthesis [NexGen Legacy Posterior Stabilized (LPS) TKA] was analyzed as were pre-operative imaging examination and compared with a MARS-CT examination obtained of the extracted TKA prosthesis. Radiographs, fluoroscopy, ultrasound and MRI preoperatively did not reveal the cause of the implant failure. MARS CT images of the extracted prosthesis clearly showed the presence of posteromedial polyethylene and tibial tray wear which is compatible with the clinical appearance of the extracted TKA. MARS can identify polyethylene insert and metallic tibial tray wear as a cause of TKA failure, that could not be identified with on standard pre-operative imaging. Although clinical MARS CT system is still under development, this case does illustrate its potential clinical usefulness. This is the first study to document how MARS CT imaging can detect orthopedic implant failure not detected by standard current imaging techniques. This system has a potential clinical application in orthopedic patients.

Randomised control trial on the optimal duration of non-weight-bearing walking after hallux valgus surgery.

INTRODUCTION: Hallux valgus surgery is one of the most commonly performed operations in Orthopaedics. Multiple surgical techniques have been described including arthrodesis, osteotomies and soft tissue procedures. The endoscopic-assisted distal soft tissue procedure is one of the minimally invasive surgical options with a good long-term outcome. The rehabilitation protocol for this soft tissue procedure consists of 6-weeks of non-weight bearing walking. This prolonged period of non-weight-bearing walking may ensure a good stabilization of the alignment but is difficult for the patient from a social-economical perspective. In addition, earlier mobilisation has other theoretical advantages including less atrophy and better range of motion. The objective of this trial is to investigate the effect of an earlier weight-bearing regime at 2-weeks post-surgery. METHODS: Randomised control trial of patients undergoing the endoscopic-assisted distal soft tissue procedure. Allocation and randomization of subjects were performed immediately after completion of surgery to avoid intra-operative biases. The control group underwent the usual protocol of 6-weeks of non-weight-bearing walking while the intervention group underwent 2-weeks of post-operative non-weight-bearing walking. Foot function was measured using the Foot and Ankle Outcome Score (FAOS) at the baseline, 12-week post-surgery and 26-weeks post-surgery. The hallux valgus angle, 1,2 inter-metatarsal angle and tibial sesamoid position were also measured during those time-points. RESULTS: A total of 51 participants completed the study, 29 in the control group and 22 in the early weight-bearing group. 1 patient form the early weight-bearing group was complicated with hallux varus requiring revision surgery. All the patients had significantly improved radiological angles and foot function in both the control and early weight-bearing group. At the 12-week time point, the radiological angles were the same for both groups but foot function was significantly better in the early weightbearing group. DISCUSSION: Early postoperative weight-bearing did not lead to pre-mature implant failures or increased recurrence rates. It actually resulted in fewer symptoms like stiffness, lessened pain, better performance in daily activities and a better quality of life. CONCLUSION: Early weight-bearing walking at 2-week after distal soft tissue reconstruction of hallux valgus is not only safe, it may help accelerate the rehabilitation process and allow patients to return their usual life faster.The translational potential of this article: Being a clinical trial, our results are directly translatable to hallux valgus patients. The results of this study show that a shortened non-weight bearing duration after hallux valgus surgery improves foot function at 12 weeks while not affecting recurrence risks.

The shift in macrophages polarisation after tendon injury: A systematic review.

BACKGROUND: The role of macrophages (Mφs) in tendon injury healing is controversy. The aims of this study were to determine whether there is a shift in Mφs polarisation after an acute and chronic tendon injury â€‹and to assess whether the Mφs polarisation between the partial and complete rupture is different. METHODS: This systematic review of the scientific literature was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane guidelines. PubMed database and Excerpta Medica Database (EMBASE) were used for specific search criteria. Only studies measuring Mφs using specific cell markers in Achilles tendon tissue and rotator cuff tendon tissue were included, respectively. RESULTS: Five Achilles tendon injury studies and four rotator cuff injury studies were included. Expression of the pan Mϕs marker Cluster of Differentiation (CD) 68 was significantly upregulated in acute Achilles tendon ruptures compared to intact tendons, while no significant changes were found in Mφs polarisation markers CD80 (M1 Mφs) and CD206 (M2 Mφs). High levels of CD86 (M1 Mφs) and CD206 were observed in acute partial rupture. Expression of CD68 and CD206 were significantly upregulated in chronic rotator cuff tendinopathy and downregulated as structural failure increases. A low level of CD206 was observed in complete tendon rupture regardless of acute or chronic injury. DISCUSSION AND CONCLUSION: In spite of the limited number of articles included, findings from this study suggested that the process of inflammation plays an important role in acute Achilles tendon injuries, indicated by the increased expression of CD68+ Mφs. Low levels of CD206+ Mφs were constantly observed in complete Achilles tendon rupture, while high levels of CD80+ Mφs and CD206+ Mφs were observed in partial Achilles tendon rupture, which suggested the potential correlation between M2 Mφs and tendon structure. For chronic rotator cuff injury, CD68+ Mφs and CD206+ Mφs were higher in tendinopathic tissues in comparison to the intact control tissues. Both CD68+ Mφs and CD206+ Mφs has an inverse relation to the structural failure in the torn rotator cuff tendon. After tendon rupture, the time point of biopsy specimen collection is an important factor, which could occur in the acute phase or chronic phase. Collectively, the understanding of the roles in Mφs after tendon injury is inadequate, and more research efforts should be devoted to this direction. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: This article provided a potential implication on how pan Mφs or M2 Mφs might be associated with ruptured or torn tendon structure. Managing Mφs numbers and phenotypes may lead to possible novel therapeutic approaches to the management of early tendinopathy, early acute tendon rupture, hence, promote healing after restoration surgery.

A systematic review of inflammatory cells and markers in human tendinopathy.

BACKGROUND: This article systematically reviews the current evidence regarding inflammation in Tendinopathy with the aim to increase understanding of a potential common pathophysiology. METHODS: Following the PRISMA statements, the terms: (tendinopathy OR (tendons AND rupture)) AND (inflammation OR (inflammation AND cells) OR immune system OR inflammation mediators OR bacteria) were used. One thousand four hundred thirty-one articles were identified which was screened down to 53. RESULTS: 39/53 studies mentioned inflammatory cells but had contradicting conclusions. Macrophages were the most common cell type and inflammatory markers were detectable in all the articles which measure them. CONCLUSIONS: The included studies show different conclusions, but this heterogeneity is not unexpected since the clinical criteria of 'tendinopathy' encompass a huge clinical spectrum. Different 'tendinopathy' conditions may have different pathophysiology, and even the same clinical condition may be at different disease stages during sampling, which can alter the histological and biochemical picture. Control specimen sampling was suboptimal since the healthy areas of the pathological-tendon may actually be sub-clinically diseased, as could the contralateral tendon in the same subject. Detection of inflammatory cells is most sensitive using immunohistochemistry targeting the cluster of differentiation markers, especially when compared to the conventional haematoxylin and eosin staining methods. The identified inflammatory cell types favour a chronic inflammatory process; which suggests a persistent stimulus. This means NSAID and glucocorticoids may be useful since they suppress inflammation, but it is noted that they may hinder tendon healing and cause long term problems. This systematic review demonstrates a diversity of data and conclusions in regard to inflammation as part of the pathogenesis of Tendinopathy, ranging from ongoing or chronic inflammation to non-inflammatory degeneration and chronic infection. Whilst various inflammatory markers are present in two thirds of the reviewed articles, the heterogenicity of data and lack of comparable studies means we cannot conclude a common pathophysiology from this systematic review.

Psychological processes of ACL-patients' post-surgery rehabilitation: A prospective test of an integrated theoretical model.

OBJECTIVES: The aim of this prospective study was to examine the utility of an integrated model comprising constructs from self-determination theory (SDT) and the theory of planned behavior (TPB) in predicting adherence to a post-surgery rehabilitation program in patients receiving anterior cruciate ligament (ACL) reconstruction. Constructs of the integrated model measured at baseline were expected to predict patients' rehabilitation adherence two months later. METHOD: Patients (N = 121, M age = 27.62, range = 18-53; 36.66% female) scheduled to have ACL reconstruction surgery within two months were recruited from a Hong Kong public hospital. At baseline and two-month follow-up, patients completed measures of perceived autonomy support from doctors and physiotherapists and treatment motivation from SDT, social cognition constructs from the TPB factors, and adherence to the postsurgery rehabilitation program recommended by their surgeon. RESULTS: Path analysis displayed good goodness-of-fit of the proposed model with the data (χ2 = 11.47 (df = 9), CFI = 0.98, TLI = 0.93, RMSEA = 0.06 [90% CI = 0.00; 0.10]) after controlling for age, gender, time of surgery, post-surgery rehabilitation, and injury severity. Consistent with hypotheses, perceived autonomy support from physiotherapist and autonomous treatment motivation directly and indirectly predicted the TPB constructs and treatment adherence. However, there was no association between perceived autonomy support from doctors and autonomous motivation. CONCLUSION: The integrated model was effective in explaining the psychological processes that relate to medical adherence. Findings also highlight the importance of the autonomy support from physiotherapists and provide evidence for potential intervention targets.