Aims. The ulna is an extremely rare location for primary bone tumours of the elbow in paediatrics. Although several reconstruction options are available, the optimal reconstruction method is still unknown due to the rarity of proximal ulna tumours. In this study, we report the outcomes of osteoarticular ulna allograft for the reconstruction of proximal ulna tumours. Methods. Medical profiles of 13 patients, who between March 2004 and November 2021 underwent osteoarticular ulna allograft reconstruction after the resection of the proximal ulna tumour, were retrospectively reviewed. The outcomes were measured clinically by the assessment of elbow range of motion (ROM), stability, and function, and radiologically by the assessment of allograft-host junction union, recurrence, and joint degeneration. The elbow function was assessed objectively by the Musculoskeletal Tumor Society (MSTS) score and subjectively by the Toronto Extremity Salvage Score (TESS) and Mayo Elbow Performance Score (MEPS) questionnaire. Results. The mean follow-up of patients was 60.3 months (SD 28.5). The mean elbow flexion-extension ROM was 95.8° (SD 21). The mean MSTS of the patients was 84.4 (SD 8.2), the mean TESS was 83.8 (SD 6.7), and the mean MEPS was 79.2 (SD 11.5). All the patients had radiological union at the osteotomy site. Symptomatic osteoarthritic change was observed in three patients (23%), one of whom ended up with elbow joint fusion. Two patients (15.4%) had recurrence during the follow-up period. Surgical complications included two allograft fractures, two plate fractures, three medial instabilities, and two infections. Conclusion. Osteoarticular ulna allograft reconstruction provides acceptable functional outcomes. Despite a high rate of complications, it is still a valuable reconstruction method, particularly in skeletally immature patients who need their distal humerus physis for the rest of hand growth. Cite this article: Bone Jt Open 2024;5(9):749–757

Aims. Osteoarticular reconstruction of the distal femur in childhood has the advantage of preserving the tibial physis. However, due to the small size of the distal femur, matching the host bone with an osteoarticular allograft is challenging. In this study, we compared the outcomes and complications of a resurfaced allograft-prosthesis composite (rAPC) with those of an osteoarticular allograft to reconstruct the distal femur in children. Methods. A retrospective analysis of 33 skeletally immature children with a malignant tumour of the distal femur, who underwent resection and reconstruction with a rAPC (n = 15) or osteoarticular allograft (n = 18), was conducted. The median age of the patients was ten years (interquartile range (IQR) 9 to 11) in the osteoarticular allograft group and nine years (IQR 8 to 10) in the rAPC group (p = 0.781). The median follow-up of the patients was seven years (IQR 4 to 8) in the osteoarticular allograft group and six years (IQR 3 to 7) in the rAPC group (p = 0.483). Limb function was evaluated using the Musculoskeletal Tumor Society (MSTS) score. Results. At final follow-up, the knee was unstable in 9/18 patients (50%) in the osteoarticular allograft group and 2/15 patients (13%) in the rAPC group (p = 0.026). The median range of motion (ROM) of the knee was 117° (IQR 115° to 120°) in the osteoarticular allograft group and 100° (IQR 95° to 105°) in the rAPC group (p < 0.001). The median MSTS score was 25 (IQR 23 to 26) in the osteoarticular allograft group and 28 (IQR 26 to 29) in the rAPC group (p = 0.007). Osteoarthritic change was detected in 11/18 patients (61%) in the osteoarticular allograft group and in 4/15 (26%) patients in the rAPC group (p = 0.048). Conclusion. In our series, a resurfaced allograft-prosthesis composite provided better knee stability and function, with a lower rate of osteoarthritis; an osteoarticular allograft was associated with better knee ROM. Cite this article: Bone Joint J 2022;104-B(10):1174–1179

Aims. Ilium is the most common site of pelvic Ewing’s sarcoma (ES). Resection of the ilium and iliosacral joint causes pelvic disruption. However, the outcomes of resection and reconstruction are not well described. In this study, we report patients’ outcomes after resection of the ilium and iliosacral ES and reconstruction with a tibial strut allograft. Methods. Medical files of 43 patients with ilium and iliosacral ES who underwent surgical resection and reconstruction with a tibial strut allograft between January 2010 and October 2021 were reviewed. The lesions were classified into four resection zones: I. 1. , I. 2. , I. 3. , and I. 4. , based on the extent of resection. Functional outcomes, oncological outcomes, and surgical complications for each resection zone were of interest. Functional outcomes were assessed using a Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS). Results. The mean age of the patients was 17 years (SD 9.1). At a mean follow-up of 70.8 months (SD 50), the mean functional outcomes were 24.2 points (SD 6.3) for MSTS and 81 points (SD 11) for TESS. The mean MSTS and TESS scores were associated with the iliac resection zone (< 0.001). Nine patients (20.9%) had local recurrence. The recurrence was not associated with the zone of iliac resection (p = 0.324). The two-year disease-free survival of the patients was 69.4%. The mean time to graft union was longer in patients with the I. 4. resection zone (p < 0.001). The complication rate was 34.9%, and nerve palsy (11.6%) was the most common. The rate of surgical complications was not associated with the resection zone. Conclusion. Reconstruction using tibial strut allograft is an efficient procedure after the resection of the ilium and iliosacral ES. Functional outcomes and complications of iliac ES depend on the resection zone, and inferior outcomes could be generally expected when more segments of the pelvic ring are resected, even if it is reconstructed. Cite this article: Bone Jt Open 2024;5(5):385–393

In this study, we aimed to investigate tibiofemoral and allograft loading parameters after OCA transplantation using tibial plateau shell grafts to characterize the clinically relevant biomechanics that may influence joint kinematics and OCA osseointegration after transplantation. The study was designed to test the hypothesis that there are significant changes in joint loading after tibial plateau OCA transplantation that may require unique post-operative rehabilitation regimens in patients to restore balance in the knee joint. Fresh-frozen cadaveric knees (n=6) were thawed and mounted onto a 6 DOF KUKA robot. Specimens were size matched to +2 mm for the medial-to-lateral width of the medial tibial hemiplateaus. Three specimens served as allograft recipient knees and three served as donor knees. Recipient knees were first tested in their native state and then tested with size-matched medial tibial hemiplateau shell grafts (n=3) prepared from the donor knees using custom-cut tab-in-slot and subchondral drilling techniques. Tekscan sensors were placed in the joint spaces to evaluate the loading conditions under 90N biaxial loading at full extension of the knee before and after graft placement. The I-Scan system used in conjunction analyzed the total force, pressure distribution, peak pressure, and center of force within the joint space. Data demonstrated significant difference (p<0.05) in joint space loading after graft implantation compared to controls in both lateral and medial tibial plateaus. The I-Scan pressure mapping system displayed changes in femoral condylar contact points as well. The results demonstrated that joint space loading was significantly different (p<0.05) between all preoperative and postoperative cadaveric specimens. Despite the best efforts to size match grafts, slight differences in the host's joint geometry resulted in shifts of contact areas between the tibial plateau and femoral condyle therefore causing either an increase or decrease in pressure measured by the sensor. This concludes that accuracy in graft size matching is extremely important to restoring close to normal loading across the joint and this can be further ensured through postoperative care customized to the patient after OCA surgery

Aims. To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability. Methods. This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included “allograft”, “shoulder”, “humerus”, and “glenoid”. The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results. Results. A meta-analysis of primary outcomes across 17 studies revealed a dislocation rate of 5.1% and an increase in reoperation rates from 9.3% to 13.7% post-publication bias adjustment. There was also a noted rise in conversion to total shoulder arthroplasty and incidence of osteoarthritis/osteonecrosis over longer follow-up periods. Patient-reported outcomes and functional tests generally showed improvement, albeit with notable variability across studies. A concerning observation was the consistent presence of allograft resorption, with rates ranging from 33% to 80%. Comparative studies highlighted similar efficacy between distal tibial allografts and Latarjet procedures in most respects, with some differences in specific tests. Conclusion. OCA transplantation presents a promising treatment option for shoulder instability, effectively addressing both glenoid and humeral head defects with favourable patient-reported outcomes. These findings advocate for the inclusion of OCA transplantation in treatment protocols for shoulder instability, while also emphasizing the need for further high-quality, long-term research to better understand the procedure’s efficacy profile. Cite this article: Bone Jt Open 2024;5(7):570–580

Aims. To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia. Methods. We reviewed patients with severe hip dysplasia, defined as Severin IVb or V (lateral centre-edge angle (LCEA) < 0°), who underwent TOA with a structural bone allograft between 1998 and 2019. A medical chart review was conducted to extract demographic data, complications related to the osteotomy, and modified Harris Hip Score (mHHS). Radiological parameters of hip dysplasia were measured on pre- and postoperative radiographs. The cumulative probability of TOA failure (progression to Tönnis grade 3 or conversion to total hip arthroplasty) was estimated using the Kaplan–Meier product-limited method, and a multivariate Cox proportional hazard model was used to identify predictors for failure. Results. A total of 64 patients (76 hips) were included in this study. The median follow-up period was ten years (interquartile range (IQR) five to 14). The median mHHS improved from 67 (IQR 56 to 80) preoperatively to 96 (IQR 85 to 97) at the latest follow-up (p < 0.001). The radiological parameters improved postoperatively (p < 0.001), with the resulting parameters falling within the normal range in 42% to 95% of hips. The survival rate was 95% at ten years and 80% at 15 years. Preoperative Tönnis grade 2 was an independent risk factor for TOA failure. Conclusion. Our findings suggest that TOA with structural bone allografting is a viable surgical option for correcting severely dysplastic acetabulum in adolescents and young adults without advanced osteoarthritis, with favourable mid-term outcomes. Cite this article: Bone Joint J 2023;105-B(7):743–750

Aims. Tibial tubercle osteotomy (TTO) facilitates surgical exposure and protects the extensor mechanism during revision total knee arthroplasty (rTKA). The purpose of this study was to determine the rates of bony union, complications, and reoperations following TTO during rTKA, to assess the functional outcomes of rTKA with TTO at two years’ minimum follow-up, and to identify the risk factors of failure. Methods. Between January 2010 and September 2020, 695 rTKAs were performed and data were entered into a prospective database. Inclusion criteria were rTKAs with concomitant TTO, without extensor mechanism allograft, and a minimum of two years’ follow-up. A total of 135 rTKAs were included, with a mean age of 65 years (SD 9.0) and a mean BMI of 29.8 kg/m. 2. (SD 5.7). The most frequent indications for revision were infection (50%; 68/135), aseptic loosening (25%; 34/135), and stiffness (13%; 18/135). Patients had standardized follow-up at six weeks, three months, six months, and annually thereafter. Complications and revisions were evaluated at the last follow-up. Functional outcomes were assessed using the Knee Society Score (KSS) and range of motion. Results. The mean follow-up was 51 months (SD 26; 24 to 121). Bony union was confirmed in 95% of patients (128/135) at a mean of 3.4 months (SD 2.7). The complication rate was 15% (20/135), consisting of nine tibial tubercle fracture displacements (6.7%), seven nonunions (5%), two delayed unions, one tibial fracture, and one wound dehiscence. Seven patients (5%) required eight revision procedures (6%): three bone grafts, three osteosyntheses, one extensor mechanism allograft, and one wound revision. The functional scores and flexion were significantly improved after surgery: mean KSS knee, 48.8 (SD 17) vs 79.6 (SD 20; p < 0.001); mean KSS function, 37.6 (SD 21) vs 70.2 (SD 30; p < 0.001); mean flexion, 81.5° (SD 33°) vs 93° (SD 29°; p = 0.004). Overall, 98% of patients (n = 132) had no extension deficit. The use of hinge implants was a significant risk factor for tibial tubercle fracture (p = 0.011). Conclusion. TTO during rTKA was an efficient procedure to improve knee exposure with a high union rate, but had significant specific complications. Functional outcomes were improved at mid term. Cite this article: Bone Joint J 2023;105-B(10):1078–1085

Aims. Long-term outcomes following the use of human dermal allografts in the treatment of symptomatic irreparable rotator cuff tears are not known. The aim of this study was to evaluate these outcomes, and to investigate whether this would be a good form of treatment in young patients in whom a reverse shoulder arthroplasty should ideally be avoided. Methods. This prospective study included 47 shoulders in 45 patients who underwent an open reconstruction of the rotator cuff using an interposition GraftJacket allograft to bridge irreparable cuff tears, between January 2007 and November 2011. The Oxford Shoulder Score (OSS), pain score, and range of motion (ROM) were recorded preoperatively and at one year and a mean of 9.1 years (7.0 to 12.5) postoperatively. Results. There was significant improvement in the mean OSS from 24.7 (SD 5.4) preoperatively to 42.0 (SD 6.3) at one year, and this improvement was maintained at 9.1 years (p < 0.001), with a score of 42.8 (SD 6.8). Similar significant improvements in the pain score were seen and maintained at the final follow-up from 6.1 (SD 1.6) to 2.1 (SD 2.3) (p < 0.001). There were also significant improvements in the ROM of the shoulder, and patient satisfaction was high. Conclusion. The use of an interposition human dermal allograft in patients with an irreparable rotator cuff tear leads to good outcomes that are maintained at a mean of nine years postoperatively. Cite this article: Bone Joint J 2022;104-B(1):91–96

Impaction allografting is increasingly used for the treatment of failed total hip replacements. In six human cadaveric femurs the impaction allografting procedure was performed to comprehensively describe the postoperative morphology of impaction allografting. After the procedure, the specimens were sectioned and prepared for histomorphometric analysis. The graft porosity was lowest in Gruen zone four (52%) and highest in Gruen zone one (76%). At the level of Gruen zone six and two, virtually the entire cross-section was filled with bone cement. The presented data will serve as a baseline for future investigations of the impaction allografting. Impaction allografting is an attractive procedure for the treatment of failed total hip replacements. The purpose of this study was to comprehensively describe the morphology of impaction allografting post operatively to form a baseline for further investigations. Three experienced surgeons performed the impaction allografting procedure on six cadaveric femurs. After the procedure, the femurs were cut in 6mm thick transverse sections and processed for histomorphometric analysis. The porosity of the impacted graft was highest proximally in Gruen zone one (76%) and lowest in Gruen zone four (52%). Below the tip of the stem (Gruen zone four), the mean cement penetration was significantly lower compared to the proximal part of the femur. The averaged residual impacted graft layer in Gruen zone six and two was (0.5mm SD 0.4mm) significantly thinner compared with Gruen zone’s one, 7/1, and four. In the region of Gruen zone six and two the entire cross-section was penetrated with bone cement with almost no residual graft layer (Figure). Even the simulated lytic defects in this region were filled with the graft cement composite which may not be remodelled by the host bone. The graft porosity was found to be highest proximally and lowest distally. In the region of Gruen zone six and two the entire cross-section was penetrated with bone cement with almost no residual graft layer. This investigation will serve as a baseline for future studies of the mechanical and biological processes that make the impaction allografting a successful procedure. Funding: Stryker Howmedica and DePuy for provided implants and instruments. Please contact author for figures and/or diagrams

Aims. Giant cell tumours (GCTs) of the proximal femur are rare, and there is no consensus about the best method of filling the defect left by curettage. In this study, we compared the outcome of using a fibular strut allograft and bone cement to reconstruct the bone defect after extended curettage of a GCT of the proximal femur. Methods. In a retrospective study, we reviewed 26 patients with a GCT of the proximal femur in whom the bone defect had been filled with either a fibular strut allograft (n = 12) or bone cement (n = 14). Their demographic details and oncological and nononcological complications were retrieved from their medical records. Limb function was assessed using the Musculoskeletal Tumor Society (MSTS) score. Results. Mean follow-up was 116 months (SD 59.2; 48 to 240) for the fibular strut allograft group and 113 months (SD 43.7; 60 to 192) for the bone cement group (p = 0.391). The rate of recurrence was not significantly different between the two groups (25% vs 21.4%). The rate of nononcological complications was 16.7% in the strut allograft group and 42.8% in the bone cement group. Degenerative joint disease was the most frequent nononcological complication in the cement group. The mean MSTS score of the patients was 92.4% (SD 11.5%; 73.3% to 100.0%) in the fibular strut allograft group and 74.2% (SD 10.5%; 66.7% to 96.7%) in the bone cement group (p < 0.001). Conclusion. Given the similar rate of recurrence and a lower rate of nononcological complications, fibular strut grafting could be recommended as a method of reconstructing the bone defect left by curettage of a GCT of the proximal femur. Cite this article: Bone Joint J 2022;104-B(2):297–301

Screw fixation is an established method for anterior cruciate ligament (ACL) reconstruction, although with a high rate of implant-related complications. An allograft system for implant fixation in ACL reconstruction, the Shark Screw ACL (surgebright GmbH) could overcome some of the shortcomings of bioabsorbable screws, such as foreign body reaction, need for implant removal and imaging artefacts. However, it needs to provide sufficient mechanical stability. Therefore, the aim of this study was to investigate the biomechanical stability, especially graft slippage, of the novel allograft system versus a conventional bioabsorbable interference screw (BioComposite Interference Screw; Arthrex Inc.) for tibial implant fixation in ACL reconstruction. Twenty-four paired human proximal tibiae (3 female, 9 male, 72.7 ± 5.6 years) underwent ACL reconstruction. The quadrupled semitendinosus and gracilis tendon graft were fixed in one specimen of each pair using the allograft fixation system Shak Screw ACL and the contralateral one using an interference screw. All specimens were cyclically loaded at 1 Hz with peak load levels monotonically increased from 50 N at a rate of 0.1 N/cycle until catastrophic failure. Relative movements of the graft versus the tibia were captured with a stereographic optical motion tracking system (Aramis SRX; GOM GmbH). The two fixation methods did not demonstrate any statistical difference in ultimate load at graft slippage (p = 0.24) or estimated survival at slippage (p = 0.06). Both, the ultimate load and estimated survival until failure were higher in the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 mm (interference screw) and 11.3 mm (Shark Screw ACL). The allograft screw for implant fixation in ACL reconstruction showed similar behavior in terms of graft slippage compared to the conventional metal interference screw but underperformed in terms of ultimate load. However, the ultimate load may not be considered a direct indicator of clinical failure

Many factors have been reported to affect the functional survival of OCA transplants, including chondrocyte viability at time of transplantation, rate and extent of allograft bone integration, transplantation techniques, and postoperative rehabilitation protocols and adherence. The objective of this study was to determine the optimal subchondral bone drilling technique by evaluating the effects of hole diameter on the material properties of OCAs while also considering total surface area for potential biologic benefits for cell and vascular ingrowth. Using allograft tissues that would be otherwise discarded in combination with deidentified diagnostic imaging (MRI and CT), a model of a large shell osteochondral allograft was recreated using LS-PrePost and FEBio based on clinically relevant elastic material properties for cortical bone, trabecular bone, cartilage, and hole ingrowth tissue. The 0.8 mesh size model consisted of 4 mm trabecular bone, 4 mm cortical bone, and 3 mm cartilage sections that summed to a cross-sectional area of 1600 mm2 (40 mm x 40 mm). Holes were modeled to be 4mm deep in relation to clinical practice where holes are drilled from the deep margin of subchondral trabecular bone to the cortical subchondral bone plate. To test the biomechanic variations between drill hole sizes, models with hole sizes pertinent to standard-of-care commercially available orthopaedic drill sizes of 1.1mm, 2.4 mm, or 4.0 mm holes were loaded across the top surface over a one second duration and evaluated for effective stress, effective strain, 1st principal strain, and 3rd principal strain in compressive conditions. Results measured effective stress and strain and 1st and 3rd principal strain increased with hole depth. The results of the present FEA modeling study indicate that the larger 4.0 mm diameter holes were associated with greater stresses and strains within OCA shell graft, which may render the allograft at higher risk for mechanical failure. Based on these initial results, the smaller diameter 2.4 mm and 1.1 mm holes will be further investigated to determine optimal number, configuration, and depth of subchondral drilling for OCA preparation for transplantation

The August 2024 Oncology Roundup. 360. looks at: What factors are associated with osteoarthritis after cementation for benign aggressive bone tumour of the knee joint: a systematic review and meta-analysis; Recycled bone grafts treated with extracorporeal irradiation or liquid nitrogen freezing after malignant tumour resection; Intercalary resection of the tibia for primary bone tumours: are vascularized fibula autografts with or without allografts a durable reconstruction?; 3D-printed modular prostheses for the reconstruction of intercalary bone defects after joint-sparing limb salvage surgery for femoral diaphyseal tumours; Factors influencing the outcome of patients with primary Ewing’s sarcoma of the sacrum; The significance of surveillance imaging in children with Ewing’s sarcoma and osteosarcoma; Resection margin and soft-tissue sarcomas of the extremities treated with limb-sparing surgery and postoperative radiotherapy

Aims. The proximal tibia (PT) is the anatomical site most frequently affected by primary bone tumours after the distal femur. Reconstruction of the PT remains challenging because of the poor soft-tissue cover and the need to reconstruct the extensor mechanism. Reconstructive techniques include implantation of massive endoprosthesis (megaprosthesis), osteoarticular allografts (OAs), or allograft-prosthesis composites (APCs). Methods. This was a retrospective analysis of clinical data relating to patients who underwent proximal tibial arthroplasty in our regional bone tumour centre from 2010 to 2018. Results. A total of 76 patients fulfilled the inclusion criteria and were included in the study. Mean age at surgery was 43.2 years (12 to 86 (SD 21)). The mean follow-up period was 60.1 months (5.4 to 353). In total 21 failures were identified, giving an overall failure rate of 27.6%. Prosthesis survival at five years was 75.5%, and at ten years was 59%. At last follow-up, mean knee flexion was 89.8° (SD 36°) with a mean extensor lag of 18.1° (SD 24°). In univariate analysis, factors associated with better survival of the prosthesis were a malignant or metastatic cancer diagnosis (versus benign), with a five- and ten-year survival of 78.9% and 65.7% versus 37.5% (p = 0.045), while in-hospital length of stay longer than nine days was also associated with better prognosis with five- and ten-year survival rates at 84% and 84% versus 60% and 16% (p < 0.001). In multivariate analysis, only in-hospital length of stay was associated with longer survival (hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.08 to 0.66). Conclusion. We have shown that proximal tibial arthroplasty with endoprosthesis is a safe and reliable method for reconstruction in patients treated for orthopaedic oncological conditions. Either modular or custom implants in this series performed well. Cite this article: Bone Jt Open 2022;3(9):733–740

The purpose of this study is to enhance massive bone allografts osseointegration used to reconstruct large bone defects. These allografts show >50% complication rate requiring surgical revision in 20% cases. A new protocol for total bone decellularisation exploiting the vasculature can offer a reduction of postoperative complication by annihilating immune response and improving cellular colonization/ osseointegration. The nutrient artery of 18 porcine bones - humerus/femur/radius/ulna - was cannulated. The decellularization process involved immersion and sequential perfusion with specific solvents over a course of one week. Perfusion was realized by a peristaltic pump (mean flow rate: 6ml/min). The benefit of arterial perfusion was compared to a control group kept in immersion baths without perfusion. Bone samples were processed for histology (HE, Masson's trichrome and DAPI for cell detection), immunohistochemistry (IHC : Collagen IV/elastin for intraosseous vascular system evaluation, Swine Leukocyte Antigen – SLA for immunogenicity in addition to cellular clearance) and DNA quantification. Sterility and solvent residues in the graft were also evaluated with thioglycolate test and pH test respectively. Compared to native bones, no cells could be detected and residual DNA was <50ng/mg dry weight. Intramedullary spaces were completely cleaned. IHC showed the preservation of intracortical vasculature with channels bounded by Collagen IV and elastin within Haversian systems. IHC also showed a significant decrease in SLA signaling. All grafts were sterile at the last decellularization step and showed no solvent residue. The control group kept in immersion baths, paired with 6 perfused radii/ulnae, showed that the perfusion is mandatory to ensure complete decellularisation. Our results prove the effectiveness of a new concept of total bone decellularisation by perfusion. These promising results could lead to a new technique of Vascularized Composite Allograft transposable to pre-clinical and clinical models

Bone infections due to fractures or implants are a big medical problem. In experimental medicine, many experimental models have been created on different animal species to simulate the disease condition and to do experience treatments. The aim of this paper was to present an antibacterial efficacy of using a bone allograft developed according to the Marburg system of bone bank on a model of chronic osteomyelitis induced in rabbits. In research was used 54 rabbits. Osteomyelitis was induced in rabbits by a human strain of St. aureus ATCC 43300, in the rabbit femur. There have been created 3 groups of animals. In 1. st. group used antibiotic impregnated biodegradable material “PerOssal”. In 2. nd. group used antibiotic impregnated whole bone allograft. In 3. rd. group used antibiotic impregnated perforated bone allograft. Evaluation of installation and evolution of the disease was done by microbiological. A separate study of microbiological data is presented here. This study showed, in the 1. st. and 3. rd. groups there is a persistent decrease in CFU by 14 knocks to 120.4 in the 1. st. group and to 3.5 in the 3. rd. group, and in the 2. nd. group, on the contrary, there is an increase in CFU to 237.33. This shows the lack of effectiveness of using a whole bone allograft. The results showed, after 7 days there was no statistically significant difference between the groups. After 14 days the perforated bone allograft impregnated with antibiotic was better than the biodegradable material “PerOssal”

Introduction. Cancellous and cortical bone used as a delivery vehicle for antibiotics. Recent studies with cancellous bone as an antibiotic carrier in vitro and in vivo showed high initial peak concentrations of antibiotics in the surrounding medium. However, high concentrations of antibiotics can substantially reduce osteoblast replication and even cause cell death. Objectives. To determine whether impregnation with gentamycine impair the incorporation of bone allografts, as compared to allografts without antibiotic. Materials and method. Seventy two healthy rabbits (24 rabbits in each group) were used for this study. Bone defects (3-mm diameter, 10-mm depth) were created in the femur. Human femoral head prepared according to the Marburg bone bank system was used as bone allograft. In the experimental groups, in 1 group - the defects were filled with bone allografts, in 2 group – Perforated Gentamycin-impregnated bone allografts. The control group did not receive any filling. The animals were killed after 14, 30 and 60 days. Evaluations consisted of X-ray plain radiography, histology at 14-, 30- and 60-days post-surgery. Results. Active osteoblast activity and active formation of new bones were detected around the defect area in all groups, but the amount of new bone formation was greater in the experimental groups than the control group. We found no statistically significant differences in the rate of bone formation between 1 and 2 groups at 14, 30 and 60 days in any of the parameters studied. X-ray results showed no significant difference in bony callus formation around allografts in 1 and 2 groups. In contrast, no significant callus formation was observed in the control group. Conclusion. The use of gentamycin-impregnated bone allografts may be of value in procedures performed at the site of osteomyelitis which require a second stage reconstruction with impacted bone grafting techniques

Introduction. Chronic ruptures of the quadriceps tendon after total knee arthroplasty (TKA) are rare but are a devastating complication. The objective of this study was to validate the use of fresh frozen total fresh quadriceps tendon allografts for quadriceps tendon reconstruction. The hypothesis of this work was that the graft was functional in more than 67% of cases, a higher percentage than the results of conventional treatments. Material – methods. We designed a continuous monocentric retrospective study of all patients operated on between 2009 and 2017 for a chronic rupture of the quadriceps tendon after TKA by quadriceps allograft reconstruction. The usual demographic and perioperative data and the rehabilitation protocols followed were collected. Initial and final radiographs were analyzed to measure patellar height variation. The main criterion was the possibility of achieving an active extension of the knee with a quadriceps contraction force greater than or equal to 3/5 or the possibility of lifting the heel off the ground in a sitting position. Results. 29 patients with 33 allografts were included; 3 iterative allografts were performed on ruptures of the initial transplant and 1 patient was grafted on both sides in one step. There were 21 women and 8 men with a mean age of 73 years, and a mean body mass index of 33 kg/m. 2. Ruptures occurred in 22 cases after chronic periprosthetic infection. Walking was allowed immediately in 29 cases, but free mobilization was delayed in 29 cases. Complications affected 22 cases, but the majority of complications were not related to allograft use (including infectious failures and periprosthetic fractures). After a mean follow-up of 52 months, 28 allografts were still in place, and 22 allografts were considered functional. The active quadriceps extension force was rated on average at 3.5/5. The average pre/post-operative patellar height differential was +2 mm. Discussion. This continuous series of 33 allografts is in line with recent publications on the subject. It confirms their negative impact on the functional outcome of the TKA. The complication rate is high but the specific complication rate is not prohibitive. Two thirds of transplants are functional in the long term. Early rehabilitation procedures can be used in these difficult patients with encouraging results. The management of chronic ruptures of the quadriceps tendon after TKA by quadriceps allograft must be part of the current therapeutic options

Large cartilage lesions in younger patients can be treated by fresh osteochondral allograft transplantation, a surgical technique that relies on stable initial fixation and a minimum chondrocyte viability of 70% in the donor tissue to be successful. The Missouri Osteochondral Allograft Preservation System (MOPS) may extend the time when stored osteochondral tissues remain viable. This study aimed to provide an independent evaluation of MOPS storage by evaluating chondrocyte viability, chondrocyte metabolism, and the cartilage extracellular matrix using an ovine model. Femoral condyles from twelve female Arcott sheep (6 years, 70 ± 15 kg) were assigned to storage times of 0 (control), 14, 28, or 56 days. Sheep were assigned to standard of care [SOC, Lactated Ringer's solution, cefazolin (1 g/L), bacitracin (50,000 U/L), 4°C storage] or MOPS [proprietary media, 22-25°C storage]. Samples underwent weekly media changes. Chondrocyte viability was assessed using Calcein AM/Ethidium Homodimer and reported as percent live cells and viable cell density (VCD). Metabolism was evaluated with the Alamar blue assay and reported as Relative Fluorescent Units (RFU)/mg. Electromechanical properties were measured with the Arthro-BST, a device used to non-destructively compress cartilage and calculate a quantitative parameter (QP) that is inversely proportional to stiffness. Proteoglycan content was quantified using the dimethylmethylene blue assay of digested cartilage and distribution visualized by Safranin-O/Fast Green staining of histological sections. A two-way ANOVA and Tukey's post hoc were performed. Compared to controls, MOPS samples had fewer live cells (p=0.0002) and lower VCD (p=0.0004) after 56 days of storage, while SOC samples had fewer live cells (p=0.0004, 28 days; p=0.0002, 56 days) and lower VCD (p=0.0002, 28 days; p=0.0001, 56 days) after both 28 and 56 days (Table 1). At 14 days, the percentage of viable cells in SOC samples were statistically the same as controls but VCD was lower (p=0.0197). Cell metabolism in MOPS samples remained the same over the study duration but SOC had lower RFU/mg after 28 (p=0.0005) and 56 (p=0.0001) days in storage compared to controls. These data show that MOPS maintained viability up to 28 days yet metabolism was sustained for 56 days, suggesting that the conditions provided by MOPS storage allowed fewer cells to achieve the same metabolic levels as fresh cartilage. Electromechanical QP measurements revealed no differences between storage methods at any individual time point. QP data could not be used to interpret changes over time because a mix of medial and lateral condyles were used and they have intrinsically different properties. Proteoglycan content in MOPS samples remained the same over time but SOC was significantly lower after 56 days (p=0.0086) compared to controls. Safranin-O/Fast Green showed proteoglycan diminished gradually beginning at the articular surface and progressing towards bone in SOC samples, while MOPS maintained proteoglycan over the study duration (Figure 1). MOPS exhibited superior viability, metabolic activity and proteoglycan retention compared to SOC, but did not maintain viability for 56 days. Elucidating the effects of prolonged MOPS storage on cartilage properties supports efforts to increase the supply of fresh osteochondral allografts for clinical use. For any figures or tables, please contact the authors directly

Aims. The aim of this study was to evaluate the clinical and radiological outcomes of locking plate fixation, with and without an associated fibular strut allograft, for the treatment of displaced proximal humeral fractures in elderly osteoporotic patients. Patients and Methods. We undertook a retrospective comparison of two methods of fixation, using a locking plate without an associated fibular strut allograft (LP group) and with a fibular allograft (FA group) for the treatment of these fractures. The outcome was assessed for 52 patients in the LP group and 45 in the FA group, with a mean age of 74.3 years (52 to 89), at a mean follow-up of 14.2 months (12 to 19). The clinical results were evaluated using a visual analogue scale (VAS) score for pain, the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, and the range of movement. Radiological results were evaluated using the neck-shaft angle (NSA) and humeral head height (HHH). Results. The mean forward elevation in the LP and FA groups was 125.3° (. sd. 21.4) and 148.9° (. sd. 19.8), respectively (p = 0.042), while other clinical factors showed no statistically significant differences between the groups. The changes in NSA and HHH immediately after the operation and at final follow-up were significantly better in the FA group than in the LP group (p = 0.015 and p = 0.021, respectively). Conclusion. For comminuted proximal humeral fractures in osteoporotic patients, locking plate fixation with a fibular strut allograft shows satisfactory short-term results with respect to humeral head support and maintenance of reduction, and may reduce the incidence of complications associated with fixation using a locking plate alone. Cite this article: Bone Joint J 2019;101-B:260–265

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients. Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16

Abstract. Background. Osteochondral allograft (OCA) transplantation is a clinically and cost-effective option for symptomatic cartilage defects. In 2017 we initiated a program for OCA transplantation for complex chondral and osteochondral defects as a UK tertiary referral centre. Aim. To characterise the complications, re-operation rate, graft survivorship and clinical outcomes of knee OCA transplantation. Methodology. Analysis of a prospectively maintained database of patients treated with primary OCA transplantation from 2017 to 2021 with a minimum of one-year follow-up. Patient reported outcome measures (PROMs), complications, re-operations and failures were evaluated. Results. 37 patients with 37 knee OCA procedures were included (mean age 31.6 years [16–49 years]). Mean BMI 26.6 kg/m2 (19.1–35.9 kg/m2). The mean chondral defect size was 3cm2 (1.2–7.3 cm2). Mean duration of follow-up was 3.1 years (1–5.3 years). 16 patients underwent meniscal allograft transplantation (MAT), 6 underwent osteotomy and 4 underwent ligament reconstruction as concurrent procedures. Significant improvements in mean PROMs were noted at 12 months. 16 patients had reoperations of which 5 had more than one surgery. Of these patients 6 were related to OCA (mainly debridement and revision OCA in one patient), and the remainder were related to additional procedures including removal of plate in 2 patients. The overall failure rate was 1 in 37 patients (3%). Conclusions. Early experience of OCA as a treatment option for complex chondral and osteochondral lesions in the knee shows satisfactory results. The reoperation rate is high but at mean follow-up of 3.1 years the survival rate was 97%

Introduction and Objective. In recent years, along with the extending longevity of patients and the increase in their functional demands, the number of annually performed RSA and the incidence of complications are also increasing. When a complication occurs, the patient often needs multiple surgeries to restore the function of the upper limb. Revision implants are directly responsible for the critical reduction of the bone stock, especially in the shoulder. The purpose of this paper is to report the use of allograft bone to restore the bone stock of the glenoid in the treatment of an aseptic glenoid component loosening after a reverse shoulder arthroplasty (RSA). Materials and Methods. An 86-years-old man came to our attention for aseptic glenoid component loosening after RSA. Plain radiographs showed a complete dislocation of the glenoid component with 2 broken screws in the neck of glenoid. CT scans confirmed the severe reduction of the glenoid bone stock and critical bone resorption and were used for the preoperative planning. To our opinion, given the critical bone defect, the only viable option was revision surgery with restoration of bone stock. We planned to use a bone graft harvested from distal bone bank femur as component augmentation. During the revision procedure the baseplate with a long central peg was implanted “on table” on the allograft and an appropriate osteotomy was made to customize the allograft on the glenoid defect according to the CT-based preoperative planning. The Bio-component was implanted with stable screws fixation on residual scapula. We decided not to replace the humeral component since it was stable and showed no signs of mobilization. Results. The new bio-implant was stable, and the patient gained a complete functional recovery of the shoulder. The scheduled radiological assessments up to 12 months showed no signs of bone resorption or mobilization of the glenoid component. Conclusions. The use of bone allograft in revision surgery after a RSA is a versatile and effective technique to treat severe glenoid bone loss and to improve the global stability of the implant. Furthermore, it represents a viable alternative to autologous graft since it requires shorter operative times and reduces graft site complications. There are very few data available regarding the use of allografts and, although the first studies are encouraging, further investigation is needed to determine the biological capabilities of the transplant and its validity in complex revisions after RSA

Aim. There is insufficient evidence to support bony reconstruction of the pubis after a type III internal hemipelvectomy (resection of all or part of the pubis). In this study, we compared surgical complications, postoperative pain, and functional outcome in a series of patients who had undergone a type III internal hemipelvectomy with or without bony reconstruction. Methods. In a retrospective cohort study, 32 patients who had undergone a type III hemipelvectomy with or without allograft reconstruction (n = 15 and n = 17, respectively) were reviewed. The mean follow-up was 6.7 years (SD 3.8) for patients in the reconstruction group and 6.1 years (SD 4.0) for patients in the non-reconstruction group. Functional outcome was evaluated using the Musculoskeletal Tumor Society (MSTS) scoring system and the level of postoperative pain with a visual analogue scale (VAS). Results. The mean MSTS score of the patients was significantly better in patients after reconstruction (26 (SD 1.7) vs 22.7 (SD 2.0); p < 0.001). The mean visual analogue scale score for pain was significantly less in the reconstruction group (2.1 (SD 2) vs 4.2 (SD 2.2); p = 0.016). One infection occurred in each group. Bladder herniation occurred in three patients (17.6%) in the non-reconstruction group but none in the reconstruction group. Five patients (29.4%) in the non-reconstruction group and one (7%) in the reconstruction group had a limp. Graft displacement occurred in two patients in the reconstruction group. Conclusion. We recommend reconstruction of the bony defect after a type III hemipelvectomy: it gives a better functional result, less postoperative pain, and fewer late surgical complications. Cite this article: Bone Joint J 2021;103-B(6):1155–1159

Aims. The management of acetabular defects at the time of revision hip arthroplasty surgery is a challenge. This study presents the results of a long-term follow-up study of the use of irradiated allograft bone in acetabular reconstruction. Patients and Methods. Between 1990 and 2000, 123 hips in 110 patients underwent acetabular reconstruction for aseptic loosening, using impaction bone grafting with frozen, irradiated, and morsellized femoral heads and a cemented acetabular component. A total of 55 men and 55 women with a mean age of 64.3 years (26 to 97) at the time of revision surgery are included in this study. Results. At a mean follow-up of 16.9 years, there had been 23 revisions (18.7%), including ten for infection, eight for aseptic loosening, and three for dislocation. Of the 66 surviving hips (58 patients) that could be reassessed, 50 hips (42 patients; 75.6%) were still functioning satisfactorily. Union of the graft had occurred in all hips with a surviving implant. Survival analysis for all indications was 80.6% at 15 years (55 patients at risk, 95% confidence interval (CI) 71.1 to 87.2) and 73.7% at 20 years (eight patients at risk, 95% CI 61.6 to 82.5). Conclusion. Acetabular reconstruction using frozen, irradiated, and morsellized allograft bone and a cemented acetabular component is an effective method of treatment. It gives satisfactory long-term results and is comparable to other types of reconstruction. Cite this article: Bone Joint J 2018;100-B:1449–54

Bone allografts can be used in any kind of surgery involving bone from minor defects to major bone loss after tumour resection. This review describes the various types of bone grafts and the current knowledge on bone allografts, from procurement and preparation to implantation. The surgical conditions for optimising the incorporation of bone are outlined, and surgeon expectations from a bone allograft discussed

Bone allograft use in trauma and orthopaedic surgery is limited by the potential for cross infection due to inadequate acceptable decontamination methods. Current methods for allograft decontamination either put the recipient at risk of potentially pathogenic organisms or markedly reduce the mechanical strength and biological properties of bone. This study developed a technique of sterilization of donor bone which also maintains its mechanical properties. Whole mature rat femurs were studied, as analogous to strut allograft. Bones were inoculated by vortexing in a solution of pathogens likely to cause cross infection in the human bone graft situation. Inoculated bones were subjected to supercritical carbon dioxide at 250 bar pressure at 35 degrees celsius for different experimental time periods until a set of conditions for sterilization was achieved. Decontamination was assessed by vortexing the treated bone in culture broth and plating this on suitable culture medium for 24 hours. The broth was also subcultured. Controls were untreated-, gamma irradiated- and dehydrated bone. Mechanical testing of the bones by precision three-point bending to failure was performed and the dimensions and cross-section digitally assessed so values could be expressed in terms of stress. Mechanical testing revealed bone treated with supercritical carbon dioxide was consistently significantly stronger than that subjected to gamma irradiation and bones having no treatment (due to the minor dehydrating effect of the carbon dioxide). Terminal sterilization of bone is achieved using supercritical carbon dioxide and this method maintains the mechanical properties. The new technique greatly enhances potential for bone allograft in orthopaedic surgery

Allograft bone is widely used in orthopaedic surgery, but peri-operative infection of the graft remains a common and disastrous complication. The efficacy of systemic prophylactic antibiotics is unproven, and since the graft is avascular it is likely that levels of antibiotic in the graft are low. Using an electrical potential to accelerate diffusion of antibiotics into allograft bone, high levels were achieved in specimens of both sheep and human allograft. In human bone these ranged from 187.1 mg/kg in endosteal (. sd. 15.7) to 124.6 (. sd. 46.2) in periosteal bone for gentamicin and 31.9 (. sd. 8.9) in endosteal and 2.9 (. sd. 1.1) in periosteal bone for flucloxacillin. The antibiotics remained active against bacteria in vitro after iontophoresis and continued to elute from the allograft for up to two weeks. Structural allograft can be supplemented directly with antibiotics using iontophoresis. The technique is simple and inexpensive and offers a potential means of reducing the rate of peri-operative infection in allograft surgery. Iontophoresis into allograft bone may also be applicable to other therapeutic compounds

Aims. Intercalary allografts following resection of a primary diaphyseal tumour have high rates of complications and failures. At our institution intercalary allografts are augmented with intramedullary cement and fixed using compression plating. Our aim was to evaluate their long-term outcomes. Patients and Methods. A total of 46 patients underwent reconstruction with an intercalary allograft between 1989 and 2014. The patients had a mean age of 32.8 years (14 to 77). The most common diagnoses were osteosarcoma (n = 16) and chondrosarcoma (n = 9). The location of the tumours was in the femur in 21, the tibia in 16 and the humerus in nine. Function was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system and the Toronto Extremity Salvage Score (TESS). The survival of the graft and the overall survival were assessed using the Kaplan-Meier method. Results. The median follow-up was 92 months (4 to 288). The mean MSTS 87 score was 29.1 (19 to 35), the mean MSTS 93 score was 82.2 (50 to 100) and the mean TESS score was 81.2 (43 to 100). Overall survival of the allograft was 84.8%. A total of 15 patients (33%) had a complication. Five allografts were revised for complications and one for local recurrence. Conclusion. Intercalary allografts augmented with intramedullary cement and compression plate fixation provide a reliable and durable method of reconstruction after the excision of a primary diaphyseal bone tumour, with high levels of function and satisfaction. . Cite this article: Bone Joint J 2017;99-B:973–8

Structural allografts may be used to manage uncontained bone defects in revision total knee replacement (TKR). However, the availability of cadaver grafts is limited in some areas of Asia. The aim of this study was to evaluate the mid-term outcome of the use of femoral head allografts for the reconstruction of uncontained defects in revision TKR, focusing on complications related to the graft. We retrospectively reviewed 28 patients (30 TKRs) with Anderson Orthopaedic Research Institute (AORI) type 3 bone defects, who underwent revision using femoral head allografts and stemmed components. The mean number of femoral heads used was 1.7 (1 to 3). The allograft–host junctions were packed with cancellous autograft. At a mean follow-up of 76 months (38 to 136) the mean American Knee Society knee score improved from 37.2 (17 to 60) pre-operatively to 90 (83 to 100) (p < 0.001). The mean function score improved from 26.5 (0 to 50) pre-operatively to 81 (60 to 100) (p < 0.001). All the grafts healed to the host bone. The mean time to healing of the graft was 6.6 months (4 to 16). There have been no complications of collapse of the graft, nonunion, infection or implant loosening. No revision surgery was required. The use of femoral head allografts in conjunction with a stemmed component and autogenous bone graft in revision TKR in patients with uncontained bone defects resulted in a high rate of healing of the graft with minimal complications and a satisfactory outcome. Longer follow-up is needed to observe the evolution of the graft. Cite this article: Bone Joint J 2013;95-B:643–8

Aims. The aim of this study was to report the outcome of femoral condylar fresh osteochondral allografts (FOCA) with concomitant realignment osteotomy with a focus on graft survivorship, complications, reoperation, and function. Patients and Methods. We identified 60 patients (16 women, 44 men) who underwent unipolar femoral condylar FOCA with concomitant realignment between 1972 and 2012. The mean age of the patients was 28.9 years (10 to 62) and the mean follow-up was 11.4 years (2 to 35). Failure was defined as conversion to total knee arthroplasty, revision allograft, or graft removal. Clinical outcome was evaluated using the modified Hospital for Special Surgery (mHSS) score. Results. A total of 14 grafts (23.3%) failed at a mean of 8.6 years (1.4 to 20.1). Graft survivorship was 87.3% (95% confidence interval (CI) 79.0 to 96.6), 85.0% (95% CI 75.8 to 95.3), 74.8% (95% CI 62.2 to 90.0), 65.2% (95% CI 49.9 to 85.2), and 59.8% (95% CI 43.5 to 82.1) at five, ten, 15, 20, and 25 years, respectively. A total of 23 patients (38.3%) developed complications, and 26 (43.3%) had a further operation. Persistent postoperative malalignment occurred more frequently in failed grafts (28.6% vs 4.3%; p = 0.023), and was a risk factor for graft failure (hazard ratio 6.55; 95% CI 1.61 27.71; p = 0.009). The mean mHSS score improved from 74.1 (40 to 91) preoperatively to 89.0 (66 to 100) at final follow-up (p < 0.001). Conclusion. Femoral condylar FOCA with concomitant realignment osteotomy provides excellent long-term graft survival and reliable functional improvement. Persistent malalignment may increase the risk for graft failure

Aims. The aim of this study was to report the medium-term outcomes of impaction bone allograft and fibular grafting for osteonecrosis of the femoral head (ONFH) and to define the optimal indications. Methods. A total of 67 patients (77 hips) with ONFH were enrolled in a single centre retrospective review. Success of the procedure was assessed using the Harris Hip Score (HHS) and rate of revision to total hip arthroplasty (THA). Risk factors were studied, including age, aetiology, duration of hip pain, as well as two classification systems (Association Research Circulation Osseous (ARCO) and Japanese Investigation Committee (JIC) systems). Results. After a mean follow-up period of 8.61 years (SD 1.45), 81.3% (52/64) of enrolled cases had a good or excellent HHS at latest follow-up (declining to 76.0% (38/50) for those with more than eight years of follow-up). Overall survival was 92.1% at eight years’ follow-up (95% CI 83.2% to 96.4%). A total of 12 hips (19.0%) failed (reoperation or HHS < 70 points) at final follow-up. Rate of success was adversely affected by increasing age, duration of pain, and more severe disease as measured using the ARCO and JIC classifications, but not by aetiology of the ONFH. Conclusion. We report favourable medium-term results of this procedure. Best outcomes can be expected in patients matching the following indications: younger than 40 years; less 12-month hip pain before surgery; femoral head collapse being less than 2 mm; and integrated lateral wall of femoral head. Cite this article: Bone Joint J 2020;102-B(7):838–844

Revision arthroplasty after infection can often be complicated by both extensive bone loss and a relatively high rate of re-infection. Using allograft to address the bone loss in such patients is controversial because of the perceived risk of bacterial infection from the use of avascular graft material. We describe 12 two-stage revisions for infection in which segmental allografts were loaded with antibiotics using iontophoresis, a technique using an electrical potential to drive ionised antibiotics into cortical bone. Iontophoresis produced high levels of antibiotic in the allograft, which eluted into the surrounding tissues. We postulate that this offers protection from infection in the high-risk peri-operative period. None of the 12 patients who had two-stage revision with iontophoresed allografts had further infection after a mean period of 47 months (14 to 78)

The outcome of tibial allograft reconstruction after resection of a tumour is inconsistent and has a high rate of failure. There are few reports on the use of tibial allografts in children with open growth plates. We performed 21 allograft reconstructions (16 osteoarticular, five intercalary) in 19 consecutive patients between seven and 17 years of age. Two had Ewing’s sarcoma, one an adamantinoma and 16 osteosarcoma, one with multifocal disease. Five patients have died; the other 14 were free from disease at the time of follow-up. Six surviving patients (eight allograft reconstructions) continue to have good or excellent function at a mean of 59 months (14 to 132). One patient has poor function at 31 months. The other seven patients have a good or excellent function after additional procedures including exchange of the allograft and resurfacing or revision to an endoprosthesis at a mean of 101 months (43 to 198). The additional operations were performed at a mean of 47 months (20 to 84) after the first reconstruction. With the use of allograft reconstruction in growing children, joints and growth plates may be preserved, at least partially. Although our results remain inconsistent, tibial allograft reconstruction in selected patients may restore complete and durable function of the limb

Background. Structural bone allografts are an established treatment method for long-bone structural defects arising from such conditions as trauma, sarcoma, and osteolysis following total joint replacement. However, the quality of structural bone allografts is difficult to non-destructively assess prior to use. The functional lifetime of structural allografts depend on their ability to resist cyclic loading, which can lead to fracture even at stress levels well below the yield strength. Because allograft bone has limited capacity for remodeling, optimizing allograft selection for bone quality could decrease long-term fracture risk. Raman spectroscopy biomarkers can non-destructively assess the three primary components of bone (collagen, mineral, and water), and may predict the resistance of donor bone allografts to fracture from cyclic loads. The purpose of this study was to prospectively assess the ability of Raman biomarkers to predict number of cycles to fracture (“cyclic fatigue life”) of human allograft cortical bone. Methods. Twenty-one cortical bone specimens were from the mid-diaphysis of human donor bone tissue (bilateral femurs from 4 donors: 63M, 61M, 51F, 48F) obtained from the Musculoskeletal Transplant Foundation. Six Raman biomarkers were analyzed: collagen disorganization, type B carbonate substitution (a surrogate for mineral maturation), matrix mineralization, and 3 water compartments. Specimens underwent cyclic fatigue testing under fully reversed conditions at 35 and 45MPa (physiologically relevant stress levels for structural allografts). Specimens were tested to fracture or to 30 million cycles (“run-out”), simulating 15 years of moderate activity (i.e., 6000 steps per day). Multivariate regression analysis was performed using a tobit model (censored linear regression) for prediction of cyclic fatigue life. Specimens were right-censored at 30 million cycles. Results. All of the 6 biomarkers that were evaluated were independently associated with cyclic fatigue life (p < 0.05). The multivariate model explained 70% of the variance in cyclic fatigue life (R2=0.695, p<0.001,). Increasing disordered collagen (p<0.001) and loosely collagen-bound water compartments (p<0.001) were associated with decreased cyclic fatigue life. Increasing type B carbonate substitution (p<0.001), matrix mineralization (p<0.001), tightly collagen-bound water (p<0.001), and mineral-bound water (p=0.002) were associated with increased cyclic fatigue life. In the predictive model, 42% of variance in cyclic fatigue life was attributable to degree of collagen disorder, all bound water compartments accounted for 6%, and age and sex accounted for 17%. Conclusions. Raman biomarkers of three bone components (collagen, mineral, and water) predict cyclic fatigue life of human cortical bone. Increased baseline collagen disorder was associated with decreased cyclic fatigue life, and was the strongest determinant of cyclic fatigue life. Increased matrix mineralization and mineral maturation were associated with increased cyclic fatigue life. Bound-water compartments of bone contributed minimally to cyclic fatigue life. These results are complementary with prior Raman studies of monotonic testing of bone that reported decreased toughness and strength with increased collagen disorder and increased stiffness with increased bone mineralization and mineral maturation. This model should be prospectively validated. Raman analysis is a promising tool for the non-destructive evaluation of structural bone allograft quality and may be useful as a screening tool for selection of allograft bone. Acknowledgements. Supported by a grant from the Musculoskeletal Transplant Foundation. The Dudley P. Allen Fellowship (JYD), Wilbert J. Austin Professor of Engineering Chair (CMR) and the Leonard Case Jr. Professor of Engineering Chair (OA) are gratefully acknowledged

The use of allografts for the treatment of bone tumours in children is limited by nonunion and the difficulty of finding a suitable graft. Furthermore, appositional growth can’t be expected of an allograft. We used an overlapping allograft in 11 children, with a mean age of ten years (4 to 15), with a mean follow-up of 24.1 months (20 to 33). There were five intercalary and six intra-articular resections, and the tumours were in the femur in six cases and the humerus in five. Rates of union, times to union, remodelling patterns and allograft-associated complications were evaluated. No allograft was removed due to a complication. Of the 16 junctional sites, 15 (94%) showed union at a mean of 3.1 months (2 to 5). Remodelling between host and allograft was seen at 14 junctions at a mean of five months (4 to 7). The mean Musculoskeletal Tumor Society score was 26.5 of 30 (88.3%). One case of nonunion and another with screw protrusion required re-operation. Overlapping allografts have the potential to shorten time to union, decrease rates of nonunion and have positive appositional growth effect

The goal of this study was to identify the effect of mismatches in the subchondral bone surface at the native:graft interface on cartilage tissue deformation in human patellar osteochondral allografts (OCA). Hypothesis: large mismatches in the subchondral bone surface will result in higher stresses in the overlying and surrounding cartilage, potentially increasing the risk of graft failure. Nano-CT scans of ten 16mm diameter cadaveric patellar OCA transplants were used to develop simplified and 3D finite element (FE) models to quantify the effect of mismatches in the subchondral bone surface. The simplified model consisted of a cylindrical plug with a 16 mm diameter (graft) and a washer with a 16 mm inner diameter and 36 mm outer diameter (surrounding native cartilage). The thickness of the graft cartilage was varied from 0.33x the thickness of native cartilage (proud graft subchondral bone) to 3x the thickness of native cartilage (sunken graft subchondral bone; Fig. 1). The thickness of the native cartilage was set to 2 mm. The surface of the cartilage in the graft was matched to the surrounding native cartilage. A 1 MPa pressure was applied to the fixed patellar cartilage surface. Scans were segmented using Dragonfly and meshed using HyperMesh. FE simulations were conducted in Abaqus 2019. The simplified model demonstrated that a high stress region occurred in the cartilage at the sharp bony edge between the graft and native subchondral bone, localized to the region with thinner cartilage. A 20% increase in applied pressure occurs up to 50μm away from the graft edge (primarily in the graft cartilage) for grafts with proud subchondral bone but varies little based on the graft cartilage thickness. For grafts with sunken subchondral bone, the size of the high stress region decreases as the difference between graft cartilage and native cartilage thickness decreases (Fig. 2-4), with a 200 μm high stress region occurring when graft cartilage was 3x thicker than native cartilage (i.e., greater graft cartilage thickness produces larger areas of stress in the surrounding native cartilage). The 3D models reproduced the key features demonstrated in the simplified model. Larger differences between native and graft cartilage thickness cause larger high stress regions. Differences between the 3D and simplified models are caused by heterogeneous cartilage surface curvature and thickness. Simplified and 3D FE analysis confirmed our hypothesis that greater cartilage thickness mismatches resulted in higher cartilage stresses for sunken subchondral bone. Unexpectedly, cartilage stresses were independent of the cartilage thickness mismatch for proud subchondral bone. These FE findings did not account for tissue remodeling, patient variability in tissue mechanical properties, or complex tissue loading. In vivo experiments with full-thickness strain measurements should be conducted to confirm these findings. Mismatches in the subchondral bone can therefore produce stress increases large enough to cause local chondrocyte death near the subchondral surface. These stress increases can be reduced by (a) reducing the difference in thickness between graft and native cartilage or (b) using a graft with cartilage that is thinner than the native cartilage. For any figures or tables, please contact the authors directly

Bone allograft is the most widely accepted approach in treating patients suffering from large segmental bone defect regardless of the advancement of synthetic bone substitutes. However, the long-term complications of allograft application in term of delayed union and nonunion were reported due to the stringent sterilization process. Our previous studies demonstrated that the incorporation of magnesium ions (Mg2+) into biomaterials could significantly promote the gene up-regulation of osteoblasts and new bone formation in animal model. Hence, our group has proposed to establish an Mg2+ enriched tissue microenvironment onto bone allograft so as to enhance the bone healing. The decellularization and gamma irradiation process were performed on bovine bone allograft and followed by magnesium plasma treatment. To evaluate the biocompatibility and bioactivity, materials characterizations, in vitro and in vivo studies were conducted, respectively. Mg composite layer on bone surface ranged from 500nm to ∼800nm thick. The cell viability on magnesium enriched allograft was significantly higher than that of the control. The ALP gene expression of hTMSCs in the group of PIII&D treated samples was highly up-regulated. The bone regeneration ability of Mg modified bone allograft implanted in animal model was significantly superior than the control after 2-month post-operation

We retrospectively reviewed 40 hips in 36 patients who had undergone acetabular reconstruction using a titanium Kerboull-type acetabular reinforcement device with bone allografts between May 2001 and April 2006. Impacted bone allografts were used for the management of American Academy of Orthopaedic Surgeons Type II defects in 17 hips, and bulk bone allografts together with impacted allografts were used for the management of Type III defects in 23 hips. A total of five hips showed radiological failure at a mean follow-up of 6.7 years (4.5 to 9.3), two of which were infected. The mean pre-operative Merle d’Aubigné score was 10 (5 to 15) vs 13.6 (9 to 18) at the latest follow-up. The Kaplan-Meier survival rate at ten years, calculated using radiological failure or revision of the acetabular component for any reason as the endpoint, was 87% (95% confidence interval 76.3 to 97.7). A separate experimental analysis of the mechanical properties of the device and the load-displacement properties of bone grafts showed that a structurally hard allograft resected from femoral heads of patients with osteoarthritis should be preferentially used in any type of defect. If impacted bone allografts were used, a bone graft thickness of < 25 mm was acceptable in Type II defects. This clinical study indicates that revision total hip replacement using the Kerboull-type acetabular reinforcement device with bone allografts yielded satisfactory mid-term results

The surgeon’s dilemma when faced with bone loss during hip replacement surgery is to try and leave more bone than he finds and risk the complications of bone grafting or use more cement or a bigger prosthesis and postpone and complicate later reconstructions. It is however a fact that good cement or prosthesis build up is better than a bad allograft. Types of allograft include bulk allograft, small fragment allograft and demineralized bone matrix. The author had in recent years done more and more mixed allografts in combination with bone graft substitutes and the present favourite is calcium sulphate pellets. Slooff believes that fresh frozen small fragments are the best, but in South Africa allografts are gamma radiated and although fears existed that gamma radiation could be detrimental to the biological response 2.5MRad dose seems to eliminate risk of infection and keep its biological properties. One of the arguments against bulk allograft is the slow and superficial incorporation and the risk of late collapse. More recently immunological response as a factor in a late failure has come to the fore. Clinical experience of up to 22 year follow up with these various types of bone grafts is discussed and representative cases shown. Where morsellized bone is used in combination with a supporting ring of cages or pressfit cups it is important that 50% of host bone contact with the metal is achieved and allograft filling up the rest as the prosthesis or cage resting on an allograft can easily fail when compression of the allograft occurring during weight bearing. Femoral struct grafts are used, where the concave side is filled with the mixed allograft and makes excellent biological plates when femoral shaft defects or peri-prosthetic fractures are treated, and full incorporation takes place. In conclusion allografts are very useful in hip revision surgery provided certain principles are adhered to

Iontophoresis is a novel technique which may be used to facilitate the movement of antibiotics into the substance of bone using an electrical potential applied externally. We have examined the rate of early infection in allografts following application of this technique in clinical practice. A total of 31 patients undergoing revision arthroplasty or surgery for limb salvage received 34 iontophoresed sequential allografts, of which 26 survived for a minimum of two years. The mean serum antibiotic levels after operation were low (gentamicin 0.37 mg/l (0.2 to 0.5); flucloxacillin 1 mg/l (0 to 1) and the levels in the drains were high (gentamicin 40 mg/l (2.5 to 131); flucloxacillin 17 mg/l (1 to 43). There were no early deep infections. Two late infections were presumed to be haemotogenous; 28 of the 34 allografts were retained. In 12 patients with pre-existing proven infection further infection has not occurred at a mean follow-up of 51 months (24 to 82)

Purpose. Cementless cup with structural allograft is one of option for acetabular revision in the cases which has severe bone loss. This study was performed to verify that the structural allograft with cementless cup could be one of good options for revision of acetabular cup with severe bone defect and to verify that the allograft resorption affect the stability of cementless acetabular cup. Materials and Methods. We reviewed 25 cases of 25 patients who underwent acetabular cup rvision using cementless porous coated hemispherical cup with structural allograft from May 1992 to July 2011 July 2011. There were nine males and sixteen females with an average age of 50.0 years. The average follow-up period was 76.7(28∼212) months. The clinical evaluation was performed using Harris Hip Score(HHS) and UCLA activity score. Radiologically, the degree of resorption of grafted bone, incorporation of allograft bone with normal bone, osteolysis and cup loosening were evaluated. Results. Clinically, the average Harris hip score was improved from 54 preoperatively to 93.4 at the last follow-up. The average UCLA activity score was also improved from 4.3 preoperatively to 6.4 at the last follow-up. Radiologically, the incorporation of allograft was accomplished in 11.4 months and the resorption of grafted bone was noted in 3 cases(12%), but the allograft resorption had not progressed to moderate degree even in long term follow-up. There was no cup loosening and average survivor rate was 100% in 6 years. There was no infection, allograft nonunion, osteolysis. Conclusion. Cementless cup with structural allograft in acetabular cup reconstruction can provide excellent mi-term results in both clinical and radiological aspects. Structural allograft can provide strong mechanical support for the bone ingrowth of cementless cup. The clinical result of this study auggest that cementless cup with structural allograft can be a good option for acetabular cup revision with severe bone defect. Resorption of structural allograft rarely occurred, and the resorption of structural allograft does not affect stablility of cup even in long term follow-up

Allografts of bone from the femoral head are often used in orthopaedic procedures. Although the donated heads are thoroughly tested microscopically before release by the bone bank, some surgeons take additional cultures in the operating theatre before implantation. There is no consensus about the need to take these cultures. We retrospectively assessed the clinical significance of the implantation of positive-cultured bone allografts. The contamination rate at retrieval of the allografts was 6.4% in our bone bank. Intra-operative cultures were taken from 426 femoral head allografts before implantation; 48 (11.3%) had a positive culture. The most frequently encountered micro-organism was coagulase-negative staphylococcus. Deep infection occurred in two of the 48 patients (4.2%). In only one was it likely that the same micro-organism caused the contamination and the subsequent infection. In our study, the rate of infection in patients receiving positive-cultured allografts at implantation was not higher than the overall rate of infection in allograft surgery suggesting that the positive cultures at implantation probably represent contamination and that the taking of additional cultures is not useful

Introduction. Reinforcement ring with allograft bone is commonly used for acetabular reconstruction of bone defects because it can achieve stable initial fixation of the prosthesis. It is not clear whether the allograft bone can function as a viable host bone and provide long-standing structural support. The purpose of this study was to assess to long-term survival of the reinforcement rings and allograft bone incorporation after acetabular revisions. Methods. We retrospectively reviewed 39 hips (37 patients) who underwent reconstruction of the acetabulum with a Ganz reinforcement ring and allograft bone in revision total hip arthroplasty. There were 18 females and 19 males with a mean age of 55.9 years (35–74 years). The minimum postoperative follow-up period was 10 years (10∼17 years). We assessed the acetabular bone defect using the Paprosky's classification. We determined the rates of loosening of the acetabular reconstructions, time to aseptic loosening, integration of the allograft bone, resorption of the allograft bone, and survival rate. Aseptic loosening of the acetabular component was defined as a change in the cup migration of more than 5 mm or a change in the inclination angle of more than 5° or breakage of the acetabular component at the time of the follow-up. Graft integration was defined as trabecular remodelling crossing the graft-host interface. Resorption of the allograft bone was classified as minor (<1/3), moderate (1/3–1/2) or severe (>1/2). Kaplan-Meier survivorship analysis was performed for aseptic loosening of the acetabular component. The results. The acetabular bone defects were classified as follows: 8 type II hips (4 type IIB, 4 type IIC), and 31 type III hips (17 type IIIA, 14 type IIIB). Fourteen (35.9%) of 39 hips was defined as aseptic loosening of an acetabular component. Loosening was more frequent in type IIIB (57.1%) than in type IIIA hips (29.4%). Mean time to aseptic loosening of the acetabular reconstructions was 6.3 years in type IIIA and from 5 years in type IIIB defects, respectively. Allograft bone incorporation was satisfactory in 66.7% of hips. There was minor bone resorption in 14.3% and moderate bone resorption in 10.2%. In 9 hips (23.1%), severe resorption of the allograft bone was observed and early component loosening was observed in these cases. The survival rate of acetabular component at 10 years of follow-up was 63.6% (95% confidence interval, 49–77%) with aseptic loosening as endpoints. Conclusions. The long-term survival rate of acetabular revision using the reinforcement ring and allograft bone in the reconstruction of severe acetabular bone defects was unsatisfactorily low due to loosening of acetabular components. Because of unfavorable graft incorporation into a host bone, an alternative component and structural support may be employed in the reconstruction of severe acetabular bone defects

Vancomycin-supplemented allografts provide biological restoration of bone stock and sound fixation with a low incidence of re-infection. Experimental incorporation of these grafts is similar to allografts without vancomycin. However, the underlying biology remains unknown. We report the first histological observations of vancomycin-supplemented impacted bone allografts in two reconstructions performed 14 and 20 months after revision surgery because of a periprosthetic fracture. Areas of active bone remodelling (creeping substitution), as well as calcified bone trabeculae and graft particles embedded in dense fibrous tissue, were observed with osteoid and fibroconnective tissue surrounding polymethylmethacrylate particles. These pathological findings are similar to those reported in allografts without vancomycin and support the hypothesis that high levels of vancomycin do not affect the incorporation of bone graft

We carried out a prospective study to determine whether the addition of a recombinant human bone morphogenetic protein (rhBMP-2) to a machined allograft spacer would improve the rate of intervertebral body fusion in the spine. We studied 77 patients who were to undergo an interbody fusion with allograft and instrumentation. The first 36 patients received allograft with adjuvant rhBMP-2 (allograft/rhBMP-2 group), and the next 41, allograft and demineralised bone matrix (allograft/demineralised bone matrix group). Each patient was assessed clinically and radiologically both pre-operatively and at each follow-up visit using standard methods. Follow-up continued for two years. Every patient in the allograft/rhBMP-2 group had fused by six months. However, early graft lucency and significant (> 10%) subsidence were seen radiologically in 27 of 55 levels in this group. The mean graft height subsidence was 27% (13% to 42%) for anterior lumbar interbody fusion, 24% (13% to 40%) for transforaminal lumbar interbody fusion, and 53% (40% to 58%) for anterior cervical discectomy and fusion. Those who had undergone fusion using allograft and demineralised bone matrix lost only a mean of 4.6% (0% to 15%) of their graft height. Although a high rate of fusion (100%) was achieved with rhBMP-2, significant subsidence occurred in more than half of the levels (23 of 37) in the lumbar spine and 33% (6 of 18) in the cervical spine. A 98% fusion rate (62 of 63 levels) was achieved without rhBMP-2 and without the associated graft subsidence. Consequently, we no longer use rhBMP-2 with allograft in our practice if the allograft has to provide significant structural support

Objectives. The most concerning infection of allografts and operative procedures is methicillin resistant Staphylococcus aureus (MRSA) and no current iontophoresed antibiotics effectively combat this microbe. It was initially hypothesised that iontophoresis of vancomycin through bone would not be effective due to its large molecular size and lack of charge. The aim of this study was to determine whether this was a viable procedure and to find the optimum conditions for its use. . Methods. An iontophoresis cell was set up with varying concentrations of Vancomycin within the medulla of a section of sheep tibia, sealed from an external saline solution. The cell was run for varying times, Vancomycin concentrations and voltages, to gain information on optimisation of conditions for impregnating the graft. Each graft was then sectioned and dust ground from the exposed surface. The dust was serially washed to extract the Vancomycin and concentrations measured and plotted for all variables tested. Results. Vancomycin was successfully delivered and impregnated to the graft using the iontophoresis technique. The first order fit to the whole data set gave a significant result (p = 0.0233), with a significant concentration (p = 0.02774) component. The time component was the next most significant (p = 0.0597), but did not exceed the 95% confidence level. Conclusions. Iontophoresis is an effective method for delivering Vancomycin to allograft bone. The concentrations of the vancomycin solution affected the bone concentration, but results were highly variable. Further study should be done on the effectiveness of delivering different antibiotics using this method. Cite this article: Bone Joint Res 2014;3:101–7

Bone allografts can store and release high levels of vancomycin. We present our results of a two-stage treatment for infected hip arthroplasty with acetabular and femoral impaction grafting using vancomycin-loaded allografts. We treated 29 patients (30 hips) by removal of the implants, meticulous debridement, parenteral antibiotic therapy and second-stage reconstruction using vancomycin-supplemented impacted bone allografts and a standard cemented Charnley femoral component. The mean follow-up was 32.4 months (24 to 60). Infection control was obtained in 29 cases (re-infection rate of 3.3%; 95% confidence interval 0.08 to 17) without evidence of progressive radiolucent lines, demarcation or graft resorption. One patient had a further infection ten months after revision caused by a different pathogen. Associated post-operative complications were one traumatic periprosthetic fracture at 14 months, a single dislocation in two hips and four displacements of the greater trochanter. Vancomycin-supplemented allografts restored bone stock and provided sound fixation with a low incidence of further infection

Aims. After intercalary resection of a bone tumour from the femur, reconstruction with a vascularized fibular graft (VFG) and massive allograft is considered a reliable method of treatment. However, little is known about the long-term outcome of this procedure. The aims of this study were to determine whether the morbidity of this procedure was comparable to that of other reconstructive techniques, if it was possible to achieve a satisfactory functional result, and whether biological reconstruction with a VFG and massive allograft could achieve a durable, long-lasting reconstruction. Patients and Methods. A total of 23 patients with a mean age of 16 years (five to 40) who had undergone resection of an intercalary bone tumour of the femur and reconstruction with a VFG and allograft were reviewed clinically and radiologically. The mean follow-up was 141 months (24 to 313). The mean length of the fibular graft was 18 cm (12 to 29). Full weight-bearing without a brace was allowed after a mean of 13 months (seven to 26). Results. At final follow-up, the mean Musculoskeletal Tumor Society Score of 22 evaluable patients was 94% (73 to 100). Eight major complications, five fractures (21.7%), and three nonunions (13%) were seen in seven patients (30.4%). Revision-free survival was 72.3% at five, ten, and 15 years, with fracture and nonunion needing surgery as failure endpoints. Overall survival, with removal of allograft or amputation as failure endpoints, was 94.4% at five, ten, and 15 years. Discussion. There were no complications needing surgical revision after five years had elapsed from surgery, suggesting that the mechanical strength of the implant improves with time, thereby decreasing the risk of complications. In young patients with an intercalary bone tumour of the femur, combining a VFG and massive allograft may result in a reconstruction that lasts a lifetime. Cite this article: Bone Joint J 2018;100-B:378–86