Evaluation of Serum Albumin-Coated Bone Allograft for Bone Regeneration: A Seven-Year Follow-Up Study of 26 Cases.

We have previously reported that serum albumin-coated bone allograft (BoneAlbumin, BA) is an effective bone substitute. It improves bone regeneration at the patellar and tibial donor sites six months after harvesting bone-patellar tendon-bone (BPTB) autografts for primary anterior cruciate ligament reconstruction (ACLR). In the present study, we examined these donor sites seven years after implantation. The study group (N = 10) received BA-enhanced autologous cancellous bone at the tibial and BA alone at the patellar site. The control group (N = 16) received autologous cancellous bone at the tibial and blood clot at the patellar site. We evaluated subcortical density, cortical thickness, and bone defect volume via CT scans. At the patellar site, subcortical density was significantly higher in the BA group at both time points. There was no significant difference in cortical thickness between the two groups at either donor site. The control group's bone defect significantly improved and reached the BA group's values at both sites by year seven. Meanwhile, the bone defects in the BA group did not change significantly and were comparable to the six-month measurements. No complications were observed. There are two limitations in this study: The number of patients recruited is small, and the randomization of the patients could have improved the quality of the study as the control group patients were older compared to the study group patients. Our 7-year results seem to demonstrate that BA is a safe and effective bone substitute that supports faster regeneration of donor sites and results in good-quality bone tissue at the time of ACLR with BPTB autografts. However, studies with a larger number of patients are required to definitively confirm the preliminary results of our study.

Tenodesis yields better functional results than tenotomy in long head of the biceps tendon operations-a systematic review and meta-analysis.

BACKGROUND: Pathology of the long head of the biceps tendon (LHBT) is a common disorder affecting muscle function and causing considerable pain for the patient. The literature on the two surgical treatment methods (tenotomy and tenodesis) is controversial; therefore, our aim was to compare the results of these interventions. METHODS: We performed a meta-analysis using the following strategy: (P) patients with LHBT pathology, (I) tenodesis, (C) tenotomy, (O) elbow flexion and forearm supination strength, pain assessed on the ten-point Visual Analog Scale (VAS), bicipital cramping pain, Constant, ASES, and SST score, Popeye deformity, and operative time. We included only randomized clinical trials. We searched five databases. During statistical analysis, odds ratios (OR) and weighted mean differences (WMD) were calculated for dichotomous and continuous outcomes, respectively, using the Bayesian method with random effect model. RESULTS: We included 11 studies in the systematic review, nine of these were eligible for the meta-analysis, containing data about 572 patients (279 in the tenodesis, 293 in the tenotomy group). Our analysis concluded that tenodesis is more beneficial considering 12-month elbow flexion strength (WMD: 3.67 kg; p = 0.006), 12-month forearm supination strength (WMD: 0.36 kg; p = 0.012), and 24-month Popeye deformity (OR: 0.19; p < 0.001), whereas tenotomy was associated with decreased 3-month pain scores on VAS (WMD: 0.99; p < 0.001). We did not find significant difference among the other outcomes. CONCLUSION: Tenodesis yields better results in terms of biceps function and is non-inferior regarding long-term pain, while tenotomy is associated with earlier pain relief.

Serum albumin-coated bone allograft (BoneAlbumin) results in faster bone formation and mechanically stronger bone in aging rats.

Serum albumin-coated bone allografts (BoneAlbumin) have successfully supported bone regeneration in various experimental models by activating endogenous progenitors. However, the effect of tissue aging, linked to declining stem cell function, has yet to be explicitly examined within the context of BoneAlbumin's regenerative capacity. Stem cell function was tested with an in vitro attachment assay, which showed that albumin coating increases stem cell attachment on demineralized bone surfaces in an aging cell population. Bone regeneration was investigated in vivo by creating critical size bone defects on the parietal bones of aging female rats. Demineralized bone matrices with and without serum albumin coating were used to fill the defects. Bone regeneration was determined by measuring the density and the size of the remaining bone defect with computed tomography (CT). Microcomputed tomography (MicroCT) and mechanical testing were performed on the parietal bone explants. In vivo CT and ex vivo microCT measurements showed better regeneration with albumin-coated grafts. Additionally, the albumin-coated group showed a twofold increase in peak fracture force compared with uncoated allografts. In the present study, serum albumin-coated demineralized bone matrices successfully supported faster and functionally superior bone regeneration in aging rats. Because stem cell function, a key contributor of bone remodelling, decreases with age and serum albumin is an effective activator of endogenous progenitor cells, this method could be an effective and safe adjuvant in bone regeneration of aging adult and osteo-compromised populations.

Bone-Albumin filling decreases donor site morbidity and enhances bone formation after anterior cruciate ligament reconstruction with bone-patellar tendon-bone autografts.

PURPOSE: Donor site pain affects 32-43 % of patients after anterior cruciate ligament surgery when the autograft is freshly harvested bone-patellar tendon-bone tissue. Our aim was to compare functional and morphological differences between donor sites with and without serum albumin-coated bone allograft filling. METHODS: After harvesting and implanting the graft, the tibia site was filled with either fresh autologous cancellous bone enhanced with albumin-coated allograft or autologous bone alone. The patella site was filled either with albumin-coated allograft or with blood clot. Knee function was evaluated by the VISA, Lysholm and IKDC scores and a visual analog scale of pain during standing, kneeling and crouching after six weeks and six months. Computed tomography was performed at six months for morphological evaluation. RESULTS: At six weeks, both groups were still recovering from surgery and the overall knee function was still impaired but the functional scores were significantly higher in the Bone-Albumin group. The pain with crouching and kneeling was also lower as compared to controls. At six months, the knee function scores were close to normal, with a slight decrease in the controls. Pain at kneeling was still prominent in the controls, but significantly lower in the Bone-Albumin group. Computed tomography showed significantly smaller bone defects and higher bone density in the Bone-Albumin group. CONCLUSIONS: Results from the present study indicate that donor site pain, a disturbing long-term side effect of bone-patellar tendon-bone surgery, is significantly reduced if bone buildup in the patella and the tibia is augmented by serum albumin-coated bone allografts.

Serum albumin enhances bone healing in a nonunion femoral defect model in rats: a computer tomography micromorphometry study.

PURPOSE: Blood-derived proliferative factors such as platelet rich plasma or activated plasma are promising adjuvants for bone grafts. Our earlier studies showed that serum albumin itself can markedly enhance the proliferation of stem cells on bone allograft and postulated that albumin coating alone may improve bone graft integration in vivo. METHODS: Two femoral defect models were performed in adult male Wistar rats. In the critical size model a six millimetre gap was created in the midshaft of the femur and fixed with plate and screws, while a nonunion model was established by the interposition of a spacer in the osteotomy for four weeks which resulted in compromised healing and nonunion. Albumin coated and uncoated grafts were placed into the defects. Bone healing and morphometry were evaluated by µCT and histology four weeks after implantation of the grafts. RESULTS: In the critical size model none of the bone grafts were able to bridge the defect, and graft resorption was the typical outcome. In the nonunion model regular uncoated grafts had a low union rate (two out of six), which increased markedly when albumin coating was applied (six out of eight). Trabecular thickness and pattern factor improved significantly in the albumin coated group versus uncoated or empty controls. CONCLUSIONS: Our results showed that serum albumin coating of bone grafts can enhance the remodelling and efficacy of treatment in a nonunion model.

Freeze-dried human serum albumin improves the adherence and proliferation of mesenchymal stem cells on mineralized human bone allografts.

Mineralized scaffolds are widely used as bone grafts with the assumption that bone marrow derived cells colonize and remodel them. This process is slow and often unreliable so we aimed to improve the biocompatibility of bone grafts by pre-seeding them with human mesenchymal stem cells from either bone marrow or dental pulp. Under standard cell culture conditions very low number of seeded cells remained on the surface of freeze-dried human or bovine bone graft or hydroxyapatite. Coating the scaffolds with fibronectin or collagen improved seeding efficiency but the cells failed to grow on the surface until the 18th day. In contrast, human albumin was a very potent facilitator of both seeding and proliferation on allografts which was further improved by culturing in a rotating bioreactor. Electron microscopy revealed that cells do not form a monolayer but span the pores, emphasizing the importance of pore size and microstructure. Albumin coated bone chips were able to unite a rat femoral segmental defect, while uncoated ones did not. Micro-hardness measurements confirmed that albumin coating does not influence the physical characteristics of the scaffold, so it is possible to introduce albumin coating into the manufacturing process of lyophilized bone allografts.