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The distal semitendinosus tendon is commonly harvested for anterior cruciate ligament reconstruction, inducing substantial morbidity at the knee. The aim of this study was to probe how morphological changes of the semitendinosus muscle after harvest of its distal tendon for anterior cruciate ligament reconstruction affects knee flexion strength and whether the knee flexor synergists can compensate for the knee flexion weakness. Ten participants 8–18 months after anterior cruciate ligament reconstruction with an ipsilateral distal semitendinosus tendon autograft performed isometric knee flexion strength testing (15°, 45°, 60°, and 90°; 0° = knee extension) positioned prone on an isokinetic dynamometer. Morphological parameters extracted from magnetic resonance images were used to inform a musculoskeletal model. Knee flexion moments estimated by the model were then compared with those measured experimentally at each knee angle position. A statistically significant between-leg difference in experimentally-measured maximal isometric strength was found at 60° and 90°, but not 15° or 45°, of knee flexion. The musculoskeletal model matched the between-leg differences observed in experimental knee flexion moments at 15° and 45° but did not well estimate between-leg differences with a more flexed knee, particularly at 90°. Further, the knee flexor synergists could not physiologically compensate for weakness in deep knee flexion. These results suggest additional factors other than knee flexor muscle morphology play a role in knee flexion weakness following anterior cruciate ligament reconstruction with a distal semitendinosus tendon graft and thus more work at neural and microscopic levels is required for informing treatment and rehabilitation in this demographic. [ABSTRACT FROM AUTHOR]

Purpose: Decades of innovations in total knee arthroplasty (TKA) design have led to large number of possible prosthesis combinations in regards fixation, posterior stability, bearing mobility, bearing surface, and patella resurfacing, each of which can alter the revision risk. The accumulative effect when the lowest risk combination in each design category, or "Optimum Prosthesis Combination" (OPC) is utilized remains unknown. The purpose of this analysis was to first, identify the OPC and second, to compare the revision risk of a cohort who received the OPC to a cohort who received an Alternative Prosthesis Combination (APC).Methods: National registry revision risk data for primary TKA for osteoarthritis were obtained from September 1999 to December 2015 for two patient cohorts, those receiving an OPC and those receiving an APC. OPC was defined as TKA with the lowest revision risk option for five primary TKA design categories; fixation, posterior stability, bearing mobility, bearing surface, and patella resurfacing, while APC had one or more higher risk options.Results: Of the 482,373 included TKA, 42,008 (8.7%) were in the OPC cohort, who received a minimally stabilized, fixed bearing TKA with cross-linked polyethylene with patella resurfacing. Both cohorts had similar demographics. At 10 years, the OPC cohort had a Cumulative Percent Revision of 2.4% (95% CI 2.1, 2.8) compared to 5.5% (95% CI 5.4, 5.6) for the APC cohort. For all patients, revision risk of the APC cohort was higher at all times [151% greater at ≥ 3 years (p < 0.001)]. Loosening/lysis was the most common cause of revision in the ACP cohort (1.1%), while it was the second most common cause in the OPC cohort (0.3%). The increased risk was apparent in all age and gender subgroups, with the highest risk increase seen in males ≥ 65 years.Conclusions: Patients receiving the lowest risk prosthesis design combination or Optimum Prosthesis Combination TKA had a 60% lower revision risk, with similar demographics to the Alternative Prosthesis Combination TKA.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: External loading of osteoarthritic and healthy knees correlates with current and future osteochondral tissue state. These relationships have not been examined following anterior cruciate ligament reconstruction. We hypothesised greater magnitude tibiofemoral contact forces were related to increased prevalence of osteochondral pathologies, and these relationships were exacerbated by concomitant meniscal injury.Methods: This was a cross-sectional study of 100 individuals (29.7 ± 6.5 years, 78.1 ± 14.4 kg) examined 2-3 years following hamstring tendon anterior cruciate ligament reconstruction. Thirty-eight participants had concurrent meniscal pathology (30.6 ± 6.6 years, 83.3 ± 14.3 kg), which included treated and untreated meniscal injury, and 62 participants (29.8 ± 6.4 years, 74.9 ± 13.3 kg) were free of meniscal pathology. Magnetic resonance imaging of reconstructed knees was used to assess prevalence of tibiofemoral osteochondral pathologies (i.e., cartilage defects and bone marrow lesions). A calibrated electromyogram-driven neuromusculoskeletal model was used to predict medial and lateral tibiofemoral compartment contact forces from gait analysis data. Relationships between contact forces and osteochondral pathology prevalence were assessed using logistic regression models.Results: In patients with reconstructed knees free from meniscal pathology, greater medial contact forces were related to reduced prevalence of medial cartilage defects (odds ratio (OR) = 0.7, Wald χ2(2) = 7.9, 95% confidence interval (CI) = 0.50-95, p = 0.02) and medial bone marrow lesions (OR = 0.8, Wald χ2(2) = 4.2, 95% CI = 0.7-0.99, p = 0.04). No significant relationships were found in lateral compartments. In reconstructed knees with concurrent meniscal pathology, no relationships were found between contact forces and osteochondral pathologies.Conclusions: In patients with reconstructed knees free from meniscal pathology, increased contact forces were associated with fewer cartilage defects and bone marrow lesions in medial, but not, lateral tibiofemoral compartments. No significant relationships were found between contact forces and osteochondral pathologies in reconstructed knees with meniscal pathology for any tibiofemoral compartment. Future studies should focus on determining longitudinal effects of contact forces and changes in osteochondral pathologies.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Background: In anterior cruciate ligament reconstruction, quadrupled semitendinosus (Quad ST) grafts have potential advantages over doubled semitendinosus-gracilis (ST/G) including larger diameter and gracilis preservation, however the ideal tibial fixation method of the resultant shorter Quad ST graft remains elusive if a fixed-loop suspensory fixation device is used on the femur. We investigated whether the tibial fixation biomechanical properties of a Quad ST fixed indirectly with polyethylene terephthalate tape tied over a screw in a full outside-in created tunnel was superior to a ST/G graft fixed with an interference screw.Materials and Methods: In a controlled laboratory study, six cadaveric matched pairs of each construct were subjected to cyclic loading to mimic physiologic loading during rehabilitation. This included preconditioning cycling, cyclic loading to 220 N for 500 cycles, then cyclic loading to 500 N for 500 cycles.Results: High standard deviations across the measured parameters occurred with no significant difference between measured parameters of elongation for the different constructs. Elongation of the Quad-ST construct was greater at 10 and 100 cycles, but not statistically different. Four of the six Quad-ST constructs failed below 100 cycles, compared with two failures below 100 cycles in the ST/G construct. There was a strong correlation between cycles to failure and bone mineral density for the Quad ST-tape constructs.Conclusions: Tibial fixation of Quad ST with a tied tape-screw construct in a full-length tunnel was not biomechanically superior to ST/G graft fixed with an interference screw, exhibited greater nonsignificant construct elongation with earlier failure, and was more reliant on bone mineral density.Level Of Evidence: In vitro laboratory study. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the pre-soaking of hamstring grafts in topical vancomycin, in addition to IV prophylaxis, during anterior cruciate ligament (ACL) reconstruction to reduce the incidence of post-operative infection, and to describe an evidence-based diagnostic and treatment algorithm to facilitate early diagnosis and appropriate management of possible knee sepsis post-operatively after ACL reconstruction.Methods: This study is a controlled observational series comprising of 1585 individuals who underwent ACL reconstruction over a 13-year period. All surgeries were performed by a single surgeon at the same hospital. Group 1 consisted of 285 patients who received pre-operative IV antibiotics without topical graft pre-soaking. Group 2 consisted of 1300 individuals who received IV antibiotics and graft pre-soaking in a vancomycin solution of 5 mg/mL.Results: In group 1, a total of four patients suffered a post-operative joint infection (1.4 %). Three out of the four were culture positive for Staphylococcus species. The fourth was culture negative but was managed as an acute infection. Group 2 suffered no post-operative infections (0 %). Statistical analysis of the vancomycin pre-soak with IV antibiotics group, compared with IV antibiotics-alone group, revealed a significantly reduced post-operative infection rate using a Fisher's exact test (P = 0.0011) and Chi-square test with Yates' correction (P = 0.0003).Conclusions: Pre-soaking of hamstrings grafts with topical vancomycin reduced the rate of post-operative infection when compared to IV antibiotics alone. This technique should be utilised by surgeons to reduce the overall incidence of knee sepsis post-ACL reconstruction.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: To examine differences in cartilage morphology between young adults 2-3 years post-anterior cruciate ligament reconstruction (ACLR), with or without meniscal pathology, and control participants.Methods: Knee MRI was performed on 130 participants aged 18-40 years (62 with isolated ACLR, 38 with combined ACLR and meniscal pathology, and 30 healthy controls). Cartilage defects, cartilage volume and bone marrow lesions (BMLs) were assessed from MRI using validated methods.Results: Cartilage defects were more prevalent in the isolated ACLR (69 %) and combined group (84 %) than in controls (10 %, P < 0.001). Furthermore, the combined group showed higher prevalence of cartilage defects on medial femoral condyle (OR 4.7, 95 % CI 1.3-16.6) and patella (OR 7.8, 95 % CI 1.5-40.7) than the isolated ACLR group. Cartilage volume was lower in both ACLR groups compared with controls (medial tibia, lateral tibia and patella, P < 0.05), whilst prevalence of BMLs was higher on lateral tibia (P < 0.001), with no significant differences between the two ACLR groups for either measure.Conclusions: Cartilage morphology was worse in ACLR patients compared with healthy controls. ACLR patients with associated meniscal pathology have a higher prevalence of cartilage defects than ACLR patients without meniscal pathology. The findings suggest that concomitant meniscal pathology may lead to a greater risk of future OA than isolated ACLR.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Background: A major limitation of total knee replacement (TKR), as with other joint replacements, is the risk of revision. Revision TKR is associated with high risk and economic burden to patients, healthcare providers, and societies. It will be worthwhile to assess the economic burden of revision TKR across countries or different study settings. This study aims to review the literature on the cost of revision TKR to assess costs across countries and studies, estimate a pooled cost estimate for homogenous data, and identify major cost components that contribute to the cost burden.We will conduct a search of the MEDLINE (OvidSp), EMBASE, Web of Science, Cochrane Library, EconLit, and Google Scholar databases to identify relevant studies, and will use an optimally designed search approach to search for relevant studies. EndNote library will be used to manage the searched studies. Selection will be undertaken in two phases—screening and eligibility. Study selection, data extraction, and assessment of the risk of bias will be performed in duplicate, after which the data will be analysed narratively and a meta-analysis performed for homogenous studies, if possible.This protocol provides a proposed stepwise plan for conducting a systematic review and meta-analysis of the cost of revision TKR. Findings from this systematic review will provide information about the cost across settings and identify the major cost drivers of revision TKR, which will, in turn, stimulate efforts to minimize the cost.PROSPERO CRD42020171988.Methods: A major limitation of total knee replacement (TKR), as with other joint replacements, is the risk of revision. Revision TKR is associated with high risk and economic burden to patients, healthcare providers, and societies. It will be worthwhile to assess the economic burden of revision TKR across countries or different study settings. This study aims to review the literature on the cost of revision TKR to assess costs across countries and studies, estimate a pooled cost estimate for homogenous data, and identify major cost components that contribute to the cost burden.We will conduct a search of the MEDLINE (OvidSp), EMBASE, Web of Science, Cochrane Library, EconLit, and Google Scholar databases to identify relevant studies, and will use an optimally designed search approach to search for relevant studies. EndNote library will be used to manage the searched studies. Selection will be undertaken in two phases—screening and eligibility. Study selection, data extraction, and assessment of the risk of bias will be performed in duplicate, after which the data will be analysed narratively and a meta-analysis performed for homogenous studies, if possible.This protocol provides a proposed stepwise plan for conducting a systematic review and meta-analysis of the cost of revision TKR. Findings from this systematic review will provide information about the cost across settings and identify the major cost drivers of revision TKR, which will, in turn, stimulate efforts to minimize the cost.PROSPERO CRD42020171988.Discussion: A major limitation of total knee replacement (TKR), as with other joint replacements, is the risk of revision. Revision TKR is associated with high risk and economic burden to patients, healthcare providers, and societies. It will be worthwhile to assess the economic burden of revision TKR across countries or different study settings. This study aims to review the literature on the cost of revision TKR to assess costs across countries and studies, estimate a pooled cost estimate for homogenous data, and identify major cost components that contribute to the cost burden.We will conduct a search of the MEDLINE (OvidSp), EMBASE, Web of Science, Cochrane Library, EconLit, and Google Scholar databases to identify relevant studies, and will use an optimally designed search approach to search for relevant studies. EndNote library will be used to manage the searched studies. Selection will be undertaken in two phases—screening and eligibility. Study selection, data extraction, and assessment of the risk of bias will be performed in duplicate, after which the data will be analysed narratively and a meta-analysis performed for homogenous studies, if possible.This protocol provides a proposed stepwise plan for conducting a systematic review and meta-analysis of the cost of revision TKR. Findings from this systematic review will provide information about the cost across settings and identify the major cost drivers of revision TKR, which will, in turn, stimulate efforts to minimize the cost.PROSPERO CRD42020171988.Systematic Review Registration: A major limitation of total knee replacement (TKR), as with other joint replacements, is the risk of revision. Revision TKR is associated with high risk and economic burden to patients, healthcare providers, and societies. It will be worthwhile to assess the economic burden of revision TKR across countries or different study settings. This study aims to review the literature on the cost of revision TKR to assess costs across countries and studies, estimate a pooled cost estimate for homogenous data, and identify major cost components that contribute to the cost burden.We will conduct a search of the MEDLINE (OvidSp), EMBASE, Web of Science, Cochrane Library, EconLit, and Google Scholar databases to identify relevant studies, and will use an optimally designed search approach to search for relevant studies. EndNote library will be used to manage the searched studies. Selection will be undertaken in two phases—screening and eligibility. Study selection, data extraction, and assessment of the risk of bias will be performed in duplicate, after which the data will be analysed narratively and a meta-analysis performed for homogenous studies, if possible.This protocol provides a proposed stepwise plan for conducting a systematic review and meta-analysis of the cost of revision TKR. Findings from this systematic review will provide information about the cost across settings and identify the major cost drivers of revision TKR, which will, in turn, stimulate efforts to minimize the cost.PROSPERO CRD42020171988. [ABSTRACT FROM AUTHOR]