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Objective:To analyze the factors affecting the relative height change of the patella after primary robotic-assisted total knee arthroplasty (R-TKA).Methods:The data of 97 patients with osteoarthritis of the knee treated with R-TKA admitted from June 2021 to March 2022 were retrospectively analyzed, including 15 males and 82 females, aged 70.0±5.4 years (range, 58-80 years). The bone resection parameters of the robotic system were recorded intraoperatively, including the bone resection amount of the medial and lateral distal femur, medial and lateral posterior femoral condyle and medial and lateral tibial plateau. The Blackburne-Peel index (BPI) and Caton-Deschamps index (CDI) were used to measure the preoperative and postoperative relative patellar height on lateral radiographs, as well as the posterior tibial slope (PTS) and the change in patellar ligament length before and after surgery. The relationship between the change in relative patellar height and the variables of interest was analyzed using partial correlation and multiple linear regression.Results:The mean postoperative CDI was lower than preoperatively (0.79±0.15 vs. 0.91±0.13, t=9.69, P<0.001), and the percentage of patients with postoperative CDI<0.6 was higher than preoperatively (9.3% vs. 0; χ 2=12.92, P<0.001); the differences in mean postoperative BPI and percentage of patients with postoperative BPI<0.45 were not statistically significant compared to preoperatively (0.69±0.13 vs. 0.71±0.17, t=1.35, P=0.182; 11.3% vs. 17.5%, χ 2=1.50, P=0.220). The mean patellar ligament length on the first postoperative day was 2.29 mm shorter than preoperatively, there was a statistically significant difference ( t=5.90, P<0.001). Partial correlation analysis showed that the amount of patellar ligament length change was positively correlated with the amount of BPI and CDI change ( r=0.84, P<0.001; r=0.70, P<0.001), and the amount of PTS change and the mean distal femoral bone resection were negatively correlated with the amount of BPI ( r= -0.41, P<0.001; r=-0.32, P=0.002) and CDI ( r=-0.23, P=0.029; r=-0.25, P=0.017) change. In contrast, the amount of posterior femoral condyle bone resection and tibial plateau bone resection did not correlate with the change of BPI and CDI. Multiple linear regression analysis showed that the amount of patellar ligament length change, PTS change and the distal femoral bone resection were factors influencing the change of BPI ( β=0.03, P<0.001; β=-0.01, P<0.001; β=-0.02, P=0.021) and CDI ( β=0.02, P<0.001; β=-0.01, P=0.001; β=-0.02, P=0.008). Conclusion:Amount of patellar ligament length change, PTS change and the distal femoral bone resection are factors affecting the BPI. In order to obtain a better relative patellar height in the primary R-TKA, attention should be paid to the adjustment of the distal femoral bone resection and PTS, while taking the necessary measures to reduce the postoperative patellar ligament length changes.
ABSTRACT
As one of the major causes of disability in the elderly population,knee osteoarthritis is a common degenerative joint disease.The general treatment approaches for knee osteoarthritis include physical therapy,nonsteroidal anti-inflammatory drugs (NSAIDs),intra-articular injection of steroid hormones,viscosupplementation and surgery,etc.Hyaluronic acid (HA) is a kind of macromolecule which plays pivotal roles in the articular physiology as a key component of synovial fluid and cartilage.Intra -articular injection of hyaluronic acid (IA-HA) is established as a local therapy to restore the viscoelasticity of synovial fluid and achieve physiological stability.Numerous clinical trials have demonstrated that IA-HA is effective in relieving pain and reducing structural damage in patients with knee osteoarthritis.Generally,the pain-relieving activity of IA-HA is comparable to or higher than that of NSAIDs,intra-articular corticosteroids,and physical therapy.In addition,IA-HA treatment is tolerated and is associated with less adverse events in comparison with NSAIDs,which elicits gastrointestinal bleedings and is associated with increased mortality.Studies in the mechanisms of action also revealed that HA could specifically bind to the membrane receptor (such as CD44) and adhesion molecules (ICAM-1) in cells.The connection may stimulate functional activities,including cell migration and proliferation.However,debates on whether hyaluronic acid produces significant clinical benefits still exist in the literature and different clinical practice guidelines.The variability in pharmaceutical property of different HA products,the severity of knee osteoarthritis,treatment protocol and injection technique can potentially have impacts on the outcomes of treatment of knee osteoarthritis with IA-HA.
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Objective To explore the clinical effects of optimized articulating medullary-sparing spacer in the treatment of infectious hip arthritis.Methods From June 2010 to June 2016,the clinical data of 15 patients with infectious hip arthritis who were treated by modified articulating medullary-sparing spacer were analyzed retrospectively.There were 6 males and 9 females with the average age of 49.6±9.6 years old (range,32-61 years).8 cases were primary hip infections and 7 cases were secondary hip joint infections.After complete debridement in the first phase of surgery,the modified articulating medullary-sparing spacers were fabricated and installed using the larger diameter and angled Steinmann pins as the endoskeleton and the femoral head spacers made by hubbing.Two-stage THA revision for each patient was conducted after infection controlled.To evaluate the clinical results,the infection and treatment condition of every patient were collected at preoperative,interim period and latest fellow-up.The spacer status in interim period and prosthesis status after two-stage THA revision were observed.And Harris hip score system was used to evaluate the hip joint function in different stages.Results All patients were cured with mean follow-up time of 40.9± 10.8 months (range,28-62 months).During the interim period,spacer dislocation was observed in a case,which was successfully treated by manual reduction under general anesthesia.In other cases,the affected limbs maintained good function and partial weight bearing.After the second-stage THA,no prosthesis loose,dislocation,fracture,deep vein thrombosis and injury of major vessels or nerves were observed.The clinical symptoms and hip joint function of all cases were significantly improved.The Harris hip score was improved from 33.7±6.9 preoperatively to 59.5±8.5 in interim period and 90.8±4.4 at the latest fellow-up,and the difference was statistically significant among three stages.Conclusion The larger diameter and angled Steinmann pins as the endoskeleton,combined with the femoral head spacers made by hubbing,effectively enhanced the mechanical strength of the articulating medullary-sparing spacers.The optimized spacers provided effective treatment of infectious hip arthritis,while allowing good function and partial weight-bearing during the interim period.
ABSTRACT
<p><b>BACKGROUND</b>Diversity of orthopedic infections with various local environments affects the pattern and prevalence of pathogens. It is not well-characterized whether different pathogens have different propensity to cause different types of orthopedic infections. We aimed to investigate the frequency of different pathogens derived from orthopedic infections, and determine the relationship between the prevalence of clinical isolates and the type of orthopedic implants, especially focusing on staphylococci.</p><p><b>METHODS</b>From January 2006 to December 2011, orthopedic infections were identified retrospectively from clinical microbiology laboratory and orthopedic medical records. The sources of orthopedic infections were divided into two main groups: those associated with implants and those not associated with implants. Implants-associated infections were further subdivided into five subgroups: arthroplasty, internal fixation, external fixation, internal and external fixation, and others. We analyzed microbiological spectrum in different groups and subgroups. Antibiotic susceptibility of staphylococci was analyzed.</p><p><b>RESULTS</b>Only coagulase-negative staphylococci (CoNS) was significantly more likely to be associated with implants-associated infections (P = 0.029). The overall pathogens prevalence of arthroplasty was significantly different from other subgroups (P < 0.05). 65% isolates from external fixation was Gram-negative bacteria. Some percentage (55%) of S. aureus and (83%) CoNS were resistant to methicillin. No resistance to glycopeptide was seen in all of staphylococci.</p><p><b>CONCLUSIONS</b>Staphylococcus aureus was the most frequent isolates in orthopedic infections but was not associated with the presence or absence of implants. Only CoNS was implants-associated, especially for arthroplasty infection. Cefazolin alone is not enough for orthopedic surgery prophylaxis in settings with a high prevalence of methicillin-resistant staphylococci.</p>
