Preservation of the meniscal volume is crucial in meniscus repair. The goal of this study was to evaluate the clinical outcome of repeated intra-articular platelet-rich plasma (PRP) injections after arthroscopic repair of a traumatic meniscal tear. We retrospectively reviewed 61 primary meniscal repairs in 61 patients (PRP group: 30; non-PRP: 31) from 2017 to 2018. Patients in the PRP group received repeated intra-articular PRP injections in week 2,4,6 after the primary meniscus repair. Subsequent meniscal repair treatment or meniscectomy, knee arthroplasty, and IKDC changes of less than 11.5 points were defined as healing failures. After following up for at least 24 months, the IKDC score was 75.1 ± 13.6, and the Lysholm score was 80.6 ± 14.9 in the PRP group and 72.6 ± 15.8 (IKDC) and 77.7 ± 17.2 (Lysholm) in the non-PRP group. Healing rates of the PRP and the non-PRP groups were 93.3% (Kaplan-Meier 91.6%) and 87.1% (Kaplan-Meier 84.7%), respectively (log rank test p = 0.874). Our study is the first to use multiple intra-articular PRP injections to facilitate meniscal healing after meniscal repair. Though selection bias may be present in this study, the PRP group had similar functional outcome and healing rate compared to non-PRP group.

The purpose of this study was to investigate whether modeling within separate body mass index (BMI) stratifications improves the accuracy of maximal oxygen uptake (VO 2max ) prediction compared to a model developed regardless of adults' BMIs. A total of 250 Taiwanese adults (total group, TOG) aged 22-64 years participated in this study, and were stratified into a normal group (NOG: 135), an overweight group (OVG: 69), and an obesity group (OBG: 46), according to the BMI classification recommended by the Taiwan Ministry of Health and Welfare. VO 2max was directly measured on an electromagnetic bicycle ergometer. Using the participant's heart rate in the 3-min incremental step-in-place test and demographic parameters, VO 2max prediction models established for four groups were TOG model, NOG model, OVG model, and OBG model, respectively. Compared with the TOG model, the OVG and OBG models had higher coefficients of determination and lower standard error of estimates (SEEs), or %SEEs. The validities of the NOG (r = 0.780), OVG (r = 0.776), and OBG (r = 0.791) models for BMI subgroups increased by 1.79%, 4.64%, and 8.22% respectively, and the reliabilities (NOG model: ICC = 0.755; OVG model: ICC = 0.765; OBG model: ICC = 0.779) increased by 3.18%, 3.27%, and 9.63%, respectively. These results suggested using separate models established in BMI stratifications can effectively improve the prediction of VO 2max .

Background: Few studies have compared the outcomes of anterior cruciate ligament (ACL) reconstruction between older patients and younger patients. Purpose: To evaluate the clinical and functional outcomes of ACL reconstruction with autologous hamstring tendon in patients >50 years and <30 years. It was hypothesized that the outcomes would be comparable between these age groups. Study Design: Cohort study; Level of evidence, 3. Methods: Patients >50 years (older group) or <30 years (younger group) who underwent ACL reconstruction surgery with autologous hamstring tendon between 2012 and 2015 at the authors’ hospital were retrospectively enrolled in this study. All patients had a minimum of 2 years of follow-up. Intraoperative findings, including cartilage and meniscal injury, were recorded, and clinical and functional outcomes were evaluated using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner activity scores. We used the paired-samples t test for statistical analysis between the 2 age groups. Results: A total of 67 patients and 459 patients were included in the older and younger groups, respectively. Both groups achieved significant preoperative to postoperative improvement in IKDC (older group, from 41.4 to 88.9; younger group, from 49 to 91.2), Lysholm (older group, from 49.8 to 86.1; younger group, from 50.2 to 91.8), and Tegner (older group, from 2.7 to 4.4; younger group, from 4.6 to 6.9) ( P < .05 for all) scores. The change in Tegner score from preinjury to postoperatively was not statistically significant in the older group (from 4.5 to 4.4; P = .471), although it was significant in the younger group (from 7.5 to 6.9; P < .05). No between-group differences were noted in preoperative or postoperative IKDC or Lysholm scores. Both age groups reached a high rate of return to sports activity, and no major complications or ACL retears were noted in either group. Conclusion: Comparable results after ACL reconstruction were achieved in patients >50 years compared with patients <30 years, with a high rate of return to sports activity and a low rate of complications at the 2-year follow-up. The younger group returned to a higher Tegner score, while the older group did not.