Does loop length change after anterior cruciate ligament reconstruction with adjustable loop cortical suspension device?: Observation of the hamstring graft completely filling the femoral tunnel.

PURPOSE: The adjustable loop cortical suspension device (ALD) is a useful femoral fixation device in anterior cruciate ligament (ACL) reconstructions, but the possibility of loosening has been suggested. The purpose of this study was to evaluate the elongation of an adjustable loop and the position of the hamstring graft inside the femoral socket. METHODS: The subjects were 33 patients who underwent ACL reconstruction with a hamstring tendon. The graft was fixed using ALD and completely filled the femoral socket. Magnetic resonance images were taken one week and one year after the operation. The loop length, femoral socket length, and graft length inside the socket were measured and statistically compared with the clinical outcomes. RESULTS: The loop length one week after surgery was 18.9 ± 4.4 mm, and 1 year after surgery was 19.9 ± 4.5 mm (P < 0.001). The gap between the top of the graft and femoral socket was 0.9 ± 1.8 mm one week after surgery and 1.3 ± 1.7 mm one year after surgery (P = 0.259). At one week post-operation, a gap was found in nine patients (27.3%). The loop length and gap did not strongly correlate with clinical findings. CONCLUSION: ACL reconstruction using ALD showed a gap between the graft and femoral socket at the one week post-operation mark in 27.3% of participants. One year after the surgery, there were cases where the gap increased and/or decreased, but the elongation of the loop was 1 mm on average. Our findings suggest that ALD is clinically safe to use; however, has the possibility of initial loop elongation and non-uniform changes. LEVEL OF EVIDENCE: IV.

Effects of bone marrow-derived mesenchymal stem cell transplantation in piglet Legg-Calve-Perthes disease models: a pilot study.

This preliminary study investigated the efficacy and safety of bone marrow-derived mesenchymal stem cell transplantation in a piglet Legg-Calve-Perthes disease (LCPD) model. The LCPD model was induced in two Landrace piglets (6- and 7-week-old, weighing 12 and 17 kg, respectively) by ligaturing the femoral neck. In the first piglet, the natural LCPD course was observed. In the second piglet, 4 weeks after ligaturing the femoral neck, simple medium and medium containing 2.44 × 107 bone marrow-derived mesenchymal stem cells were transplanted into the right and left femoral heads after core decompression, respectively. Plain radiographs were obtained every 4 weeks, and the epiphyseal quotient was calculated by dividing the maximum epiphysis height by the maximum epiphysis diameter. The piglets were sacrificed at 14 weeks postoperatively. The femoral heads were extracted and evaluated grossly, pathologically, and by using computed tomography. The transplanted cell characteristics were evaluated using flow cytometry. Flattening of the epiphysis was observed in both femoral heads of the first piglet and only in the right hip of the second piglet. The epiphyseal quotients immediately and at 14 weeks postoperatively in the right femoral head of the second piglet were 0.40 and 0.14, respectively, while those of the left femoral head were 0.30 and 0.42, respectively. Hematoxylin and eosin staining did not reveal physeal bar or tumor cell formation. The transplanted cells were 99.2%, 65.9%, 18.2%, and 0.16% positive for CD44, CD105, CD29, and CD31, respectively. Core decompression combined with bone marrow-derived mesenchymal stem cell transplantation prevented epiphyseal collapse.

A Retrospective Analysis of Clinical Outcome and Predictive Factors for Responders with Knee Osteoarthritis to a Single Injection of Leukocyte-Poor Platelet-Rich Plasma.

Although various platelet-rich plasma (PRP) kits are commercially available, the efficacy of these kits for knee osteoarthritis (KOA) has not been fully investigated. This study aimed to investigate the short-term results of leukocyte-poor PRP (LP-PRP) and the factors that contribute to its efficacy. We retrospectively reviewed 124 patients with KOA who were treated with LP-PRP. White blood cell (WBC) and platelet counts in the whole blood and the LP-PRP were measured. KOA severity was assessed using radiography. Clinical evaluation was performed both prior to injection and after an average of 3.3 weeks after the injection using the Japanese Knee Osteoarthritis Measure (JKOM). Responders were defined based on the JKOM. The contributing factors for responders were examined using a multivariate logistic analysis. The responder rate was 58.1% and the contributing factors for responders were a higher visual analog scale score before injection, WBC count in whole blood, and platelet concentration ratio of LP-PRP. The LP-PRP improved the clinical scores in the short term. Certain patient characteristics before injection and the concentration ratio of LP-PRP may be predictors of its efficacy; these may provide clues for elucidating which components of LP-PRP act on KOA pathologies.

How much platelet-rich plasma can be soak-loaded onto beta-tricalcium phosphate? A comparison with or without a unidirectional porous structure.

Objective: This study aimed to examine differences in platelet-rich plasma (PRP) soak-loaded volumes of ß-tricalcium phosphate (ß-TCP) with or without a unidirectional porous structure. Materials and Methods: Leukocyte-rich PRP was extracted from 15 healthy volunteers by centrifugation. Two types of artificial bones were soaked for either ten seconds or ten minutes. The volume ratios of PRP soak-loaded onto the artificial bone and soaked area ratios were evaluated. Statistical analyses were performed using the Tukey-Kramer HSD test and the Games-Howell method. A P-value of <0.05 was considered statistically significant. Results: Regardless of the soaking time, the PRP soak-loaded volume ratio and soaked area ratio were significantly higher in the unidirectional porous ß-TCP (UDPTCP) group than in the spherical porous ß-TCP (SPTCP) group. Conclusion: PRP can be soak-loaded faster and in larger amounts onto UDPTCP compared to SPTCP. Understanding the basic biology of ß-TCP soak-loaded with PRP can help develop more novel and effective ß-TCP treatments for orthopedic surgery.

Feasibility and efficacy of knee extension training using a single-joint hybrid assistive limb, versus conventional rehabilitation during the early postoperative period after total knee arthroplasty.

Objectives: To evaluate the feasibility and efficacy of treatment for the recovery of knee joint function after total knee arthroplasty (TKA) using a robotic suit. Patients and Methods: Knee joint extension exercise sessions were started with a robotic suit (single-joint hybrid assistive limb [HAL-SJ, Cyberdyne, Inc., Tsukuba, Japan]) in one group of patients after TKA. Patients who underwent standard rehabilitation were enrolled in the control group. To evaluate feasibility and safety, we assessed the adverse events, the number of training sessions, and training time. We compared the changes in knee joint pain and extension lag (°) between the groups. Results: The average age was 71.3 ± 6.2 years in the HAL-SJ group and 74.9 ± 8.7 years in the control group. There were no severe adverse events. In the HAL-SJ group, training was performed 2.9 times, on average, and lasted 18.8 min. In the HAL-SJ group, there was a reduction in the visual analog scale (VAS) for pain after training, which was not significant. In the control group, the VAS score worsened after the sessions. The extension lag significantly improved in the HAL-SJ group after the 2nd and 3rd sessions, and this was more due to improvements in their active extension range of motion than their passive extension range of motion. Conclusions: HAL-SJ-based training is safe and effective, and leads to instantaneous improvement of extension lag, without worsening knee joint pain. HAL-SJ-based knee extension training could represent a viable novel post-TKA rehabilitation modality.

A radiological study of bone remodeling with two different types of porous ß-tricalcium phosphate in humans.

In this study we compared the bone remodeling of unidirectional (UDPTCP) and spherical porous ß-tricalcium phosphate (SPTCP) radiologically in humans. We performed a retrospective analysis of the data of 14 patients (sex, nine men and five women; age, 37-70 years) who underwent medial opening-wedge high tibial osteotomy (MOWHTO) and were followed up for 12 months after surgery. Two wedge-shaped ß-TCPs (one UDPTCP and one SPTCP) were cut and placed parallel to each other in the gap. In Group A (eight knees), UDPTCP was implanted anteriorly and SPTCP posteriorly, while in Group B (six knees), SPTCP was implanted anteriorly and UDPTCP posteriorly. Computed tomography (CT) was performed at 1 week, 6 months, and 12 months after surgery, with the CT attenuation values calculated for UDPTCP and SPTCP. In Groups A and B, the CT attenuation values for UDPTCP were significantly lower at 6 and 12 months after surgery compared to those at 1 week (P < 0.05); nevertheless, no statistical difference in the comparison with SPTCP was observed. After a short-term follow-up of 12 months following MOWHTO, UDPTCP provided earlier bone remodeling than SPTCP. This outcome was achieved regardless of the position, anterior or posterior, in the MOWHTO gap.

Optimization of leukocyte-poor platelet-rich plasma preparation: a validation study of leukocyte-poor platelet-rich plasma obtained using different preparer, storage, and activation methods.

BACKGROUND: Alternative methods of platelet-rich plasma (PRP) preparation, storage, and activation that can be stably reproduced are needed to improve PRP production. The purpose of this study was to investigate the effect of the preparer's experience on the quality of prepared PRP, chronological changes occurring in PRP, and the effect of the activation procedures on the release of several growth factors from PRP, using PRP prepared with the PRGF-Endoret Kit. METHODS: Leukocyte-poor PRP samples from seventeen healthy volunteers were prepared using the PRGF-Endoret Kit and the PRGF IV System Centrifuge. The platelet and leukocyte concentrations were compared based on the preparer's experience. The concentrations of platelets, hepatocyte growth factor (HGF), platelet-derived growth factor-BB (PDGF-BB), and insulin-like growth factor-1 (IGF-1) were determined at 0 and 60 min after PRP preparation, and compared. Concentrations of the above growth factors from PRP activated by freeze-thaw cycling and by calcium chloride (CaCl2) were also compared. RESULTS: No significant difference was observed in the platelet concentrations and leukocyte contamination rates, based on the preparer's experience. At 60 min after PRP preparation, the platelet concentration decreased significantly, while the HGF, PDGF-BB, and IGF-1 concentrations remained unchanged. Activation with CaCl2 resulted in a significant increase in the PDGF-BB levels, although the HGF and IGF-1 concentrations remained unchanged. CONCLUSIONS: The results of this study show that leukocyte-poor PRP prepared using the PRGF-Endoret Kit did not result in any qualitative difference that depended on the experience of the preparer. However, PRP preparation required standardization in terms of the time of blood count measurement. Growth factor concentrations in PRP differed according to the platelet-activation method used.

Intraoperative Local Administration of Platelet-Rich Plasma (PRP) during Neurolysis Surgery for the Treatment of Digital Nerve Crush Injury.

The digital nerves are important for normal hand function. In addition to conventional therapies such as neurolysis, direct repair, and auto/allografts, new treatments administering growth factors and cells for promoting nerve regeneration exist. Platelet-rich plasma (PRP), an autologous product with proven therapeutic effects for musculoskeletal disorders, is a new treatment option for peripheral nerve injury. We hypothesized that PRP could stimulate healing of digital nerve injuries. In the current case report, intraoperative local administration of PRP was performed during neurolysis surgery for a healthy 28-year-old woman with digital nerve crush injury. Five weeks postinjury, surgery was performed due to severe uncontrollable neuropathic pain and no sensory nerve action potential derivation of the index finger. Therapeutic effects were assessed by physical examination, visual analog scale for pain, and nerve conduction study. Postoperatively, early neuropathic pain relief and good functional recovery were obtained with no PRP-related adverse events. This case report demonstrates the therapeutic potential of intraoperative PRP to enhance the healing process of nerve crush injury in the acute phase and to decrease the neuropathic pain, thus enhancing healing of peripheral nerve crush injury.