An investigation into the cellular-level adverse effects of tourniquet use on the infrapatellar fat pad in primary total knee arthroplasty: A prospective randomized study.

OBJECTIVE: This study aimed to examine the cellular-level adverse effects of tourniquet use on the infrapatellar fat pad (IPFP) in patients undergoing primary total knee arthroplasty (TKA). METHODS: Infrapatellar fat pad samples were collected in a prospective, randomized design to compare 2 groups of primary TKA patients with a tourniquet (T) and without a tourniquet (NT). The study included 80 knees of 58 patients with a mean age of 65.91 ± 9.04 years. The authors collected 3 samples from the T group (after exposure to the fat pad "t1," just before deflating the tourniquet "t2," just before fascia closure "t3") and 2 samples from the NT group (t1 and t3) for each patient. BAX, Bcl-2, and HIF-1α staining showed the extent of cellular hypoxia and apoptosis in IPFP cells, whereas the oxidative stress index (OSI) was determined using a biochemical method. The Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS), and Kujala score were used as clinical outcome measures. RESULTS: The mean HIF-1α, BAX/Bcl-2, and OSI scores across all time points were significantly higher in the T group than in the NT group (p<0.001) (d=1.16, 2.9, and 0.9, respectively). The mean BAX/Bcl-2 (P=.030) and HIF-1α (P < .001) scores significantly peaked at t2 in the T group (d=-1.2 and -3.9, respectively). The OSI had higher levels at t1 (P=.011) and t3 (P=.073) (d=0.2 and 0.1, respectively) than at t2 in the T group. The third-month postoperative follow-up revealed that the mean KOOS, KSS, and Kujala score improved significantly compared to the baseline preoperative values (P < .001); however, there was no difference between the T and NT groups regarding the maximum and total knee range of motion or clinical outcome scores. CONCLUSION: Evidence from this study has shown that tourniquet use during primary TKA may be associated with significantly increased cellular hypoxia, oxidative stress, and apoptosis in the IPFP. LEVEL OF EVIDENCE: Level I, Therapeutic study.

Comparison of different fixation techniques for periprosthetic fractures: a biomechanical study of a new implant.

INTRODUCTION: The ideal treatment method for periprosthetic fractures is controversial due to the risks of current methods. Single-cortex screw fixation in prosthesis may lead to implant failure. Therefore, we aimed to develop an implant that lowers the risk for complications. For this study, we designed and tested two new implant models. The first model was a plate with a combination of U nails and cerclage holes. The second model was a U nail plate with a screw, which combines a plate screw with U nail (staples). Our study aimed to compare the stability of two newly designed implants with classical treatment modalities. We used 27 (in 3 groups) artificial bone models and 9 different test models. METHODS: The ISO 7206-4:2010 (E) standards were used for 27 bones in nine groups tested under laboratory conditions. In our study, we examined nine different groups. In group 1, hip the prosthesis was extracted, and a revision femoral stem was embedded. In group 2, periprosthetic fractures were repaired with a plate and cable. In group 3, periprosthetic fractures were repaired with a plate and stapler. In group 4, periprosthetic fractures were repaired with a plate and stapler cable. In group 5, periprosthetic fractures were repaired with a plate stapler and screw. Groups 6 and 7 were the control groups. Group 6 was the only artificial bone group, and group 7 was the prosthesis embedded bone group. Group 8 was periprosthetic fractures treated with unicortical screw fixation with cerclage, and group 9 was periprosthetic fractures treated with unicortical screw fixation. Axial loading was applied to the bones. The yield strength of the system was determined by loading the synthetic bone models with a constant compression speed of 5 mm/min through the centre of motion using the Geratech SH 2000 testing system. During the tests, load and displacement values were recorded, and the stiffness of the models was calculated based on those values. RESULTS: According to our results, the greatest durability was found in the revision hip prosthesis group (1511 N), and the weakest performance was found in the plate with the stapler implant group (163N). When comparing the data of groups according to compression, significant differences were found in group 2 with groups 1, 4, 5, and 7; group 3 with group 1; group 8 with groups 1 and 5; and group 9 with 1, 5, 7, and according to breakage, significant differences were found in group2 with groups 1, 3, 5, and 7; group 3 with group 1; group 8 with groups 1 and 5; and group 9 with groups 1, 5, and 7 (p<0.001). DISCUSSION: The revision hip prosthesis treatment for periprosthetic fractures showed the best performance, followed by the plate with stapler screw. In older patients, U nail-augmented implants may be a good alternative for periprosthetic fractures. Unicortical screw and cerclage wire combination fixation results were unsatisfactory results in this study. CONCLUSION: This is an experimental study, so further studies, especially patient-specific studies, should be made to expand the findings of this study.

Triple nonunion after steel-like triple pelvic osteotomy.

Triple pelvic osteotomy (TPO) is a widely known and accepted procedure carried out to treat acetabular dysplasia in adults. According to this technique, osteotomies are performed through the ischium, ilium and pubis in order to mobilize the whole acetabulum. In this article, we report a 30-year-old female patient who was admitted to our outpatient clinic with a complaint of intense pain after standing or walking. Patient had undergone Steel-like TPO for acetabular dysplasia approximately nine months before. After physical and radiological evaluation, patient was diagnosed with triple nonunion. Patient was successfully treated with debridement and grafting at iliac nonunion site followed by refixation with reconstruction plate and screws. A review of the literature did not detect any published studies or case reports regarding symptomatic triple nonunion after TPO using Steel-like method.