High Tibial Osteotomy Versus Unicompartmental Knee Arthroplasty for Unicompartmental Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

Purpose: High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are commonly performed procedures for the treatment of compartmental knee osteoarthritis; however, the optimal procedure remains controversial. We conducted this systematic review and meta-analysis to compare the functional outcomes and assess complications and revision rates between the two techniques. Methods: We searched electronic databases for relevant studies comparing HTO versus UKA for unicompartmental knee osteoarthritis. Continuous data as visual analogue scale (VAS), range of motion, and free walking speed were pooled as mean differences (MDs). Dichotomous data as functional knee outcomes, complications, and revision were pooled as odds ratios (ORs), with 95% confidence interval (CI), using R software for windows. Results: Twenty-five studies involving 8185 patients were included. Meta-analysis showed that HTO was associated with higher risk of complications (OR = 2.47, 95% CI [1.52, 4.04]), poorer functional results (excellent/good) (OR = 0.32, 95% CI [0.21, 0.49]), and greater range of motion (MD = 7.05, 95% CI [2.41, 11.68]) compared to UKA. No significant differences were found between the compared groups in terms of VAS (MD = 0.14, 95% CI [- 0.08, 0.36]), revision rates (OR = 1.30, 95% CI [0.65, 2.60]), and free walking speed (MD = - 0.05, 95% CI [- 0.11, 0.00]). Conclusion: This study showed that UKA achieved fewer complications, better functional outcomes, and less range of motion compared to HTO. No significant differences were detected between HTO and UKA in terms of VAS and revision rate. Treatment options should be personalized to each patient considering factors such as their age, activities of daily living, their body mass index, and severity of osteoarthritis. Level of evidence: II. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-022-00620-9.

The effect of varus stem placement on joint offset during total hip arthroplasty: a virtual study.

INTRODUCTION AND AIMS: With total hip replacement (THR), varus alignment of an uncemented stem will increase offset which can have significant detrimental effects on muscular balance, leg length and overall satisfaction. Thus, we used 3D planning software to determine the change in joint offset with increasing varus stem placement. METHODS: Eight patients undergoing THR had routine computed tomography (CT) scans to allow for 3D hip planning. Each set of CTs was templated with a straight stem and an uncemented acetabular cup. Initial templating was performed to reproduce native leg length and offset. The templated stem was then rotated into varus at 1° intervals, up to 6° varus while offset changes for all varus positions were noted. This was repeated for each of 3 neck angles, 125°, 135° and 135° lateral and for each stem sizes 1, 3, 5 and 7. RESULTS: Overall, there was a mean 1.5 mm increase in offset for every 1° of varus. The stems with a 125° neck angle had the greatest increase in mean offset at 1.6 mm for every 1° of varus. The stem neck angles of 135° lateral offset and 135° standard offset, had a mean increase in offset of 1.5 mm and 1.4 mm respectively for every 1° of varus. A greater mean increase in offset for every 1° of varus was observed with increasing stem size. CONCLUSIONS: We have quantified the relationship between alignment and offset with every 1° of varus placement increasing hip offset for straight stems by 1.5 mm. This can be used as a guide for surgeons during THR so that they have a better quantitative understanding of how varus placement of the stem affects the hip offset.

Thrombosis rates using aspirin and a compression device as multimodal prophylaxis for lower limb arthroplasty in a screened population.

BACKGROUND: Venous thromboembolism (VTE) (Deep vein thrombosis (DVT), and pulmonary embolism (PE)), is a common complication in patients undergoing total joint arthroplasty (TJA). Recently, aspirin was recommended by the American Academy of Orthopaedic Surgeons (AAOS) as VTE prophylaxis following TJA. This study investigates VTE rates in TJA patients using as thromboprophylaxis. METHODS: DVT was screened for in 396 consecutive total hip or knee arthroplasty procedures. Patients were treated with early mobilisation, calf compression device and 300 mg aspirin for 5 days and then 100 mg aspirin for 5 weeks. All patients received lower-limb duplex ultrasonography prior to discharge. Patients were clinically evaluated at 6 weeks post-op documenting any VTE. RESULTS: 51 TJA's (12.87%) were complicated by VTE: one proximal, 47 distal DVT and 3 PE. No fatal PE occurred. Only four DVT were symptomatic. Of 159 THA, 2 (1.25%) had VTE: one distal DVT and one PE. Of 237 TKA, 49 (20.67%) had VTE: 1 proximal, 46 distal DVT and 2 PE. Patients with a history of diabetes and those receiving TKA were at higher risk of DVT. CONCLUSION: Multimodal VTE prophylaxis demonstrated a low rate of proximal DVT, PE and bleeding complications. The rate of asymptomatic DVT was high, but most were distal and unlikely to be clinically significant. Patients with diabetes and those receiving TKA could be at higher risk of asymptomatic DVT, and may benefit from closer clinical assessment. These findings suggest aspirin is safe and efficacious when used in combination with mechanical compressors and early mobilisation. However, our findings require further validation, particularly with larger, prospective comparative studies.

A comparison of aspirin against rivaroxaban for venous thromboembolism prophylaxis after hip or knee arthroplasty: A meta-analysis.

PURPOSE: Total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients are at an elevated risk of post-operative venous thromboembolism (VTE). Newer thromboprophylactic agents such as rivaroxaban are increasingly used and effective in preventing thromboembolic events but may worsen bleeding risk. Recent studies have suggested that the more cost-effective aspirin may also be effective in preventing VTE. This systematic review and meta-analysis aimed to compare the efficacy of aspirin against rivaroxaban for the prevention of VTE following TKA and THA. METHODS: Electronic searches were performed using five databases from their date of inception to August 2018. Relevant studies were identified, with data extracted and meta-analyzed from the studies. RESULTS: Five studies were included, which consisted of 2257 in the aspirin group and 2337 in the rivaroxaban group. There were no differences between aspirin and rivaroxaban for either VTE (p = 0.48) or its components deep vein thrombosis (p = 0.44) and pulmonary embolism (p = 0.98). Also, there were no differences between groups for either major bleeding (p = 0.17), any bleeding (p = 0.62), readmissions (p = 0.37) or wound complications (p = 0.17). CONCLUSION: Aspirin was not significantly different to rivaroxaban for prevention of VTE or adverse events after TKA or THA. However, this study was limited by the significant heterogeneity of the included studies. More large randomized studies are needed to add to this body of evidence.

Accuracy of leg length and femoral offset restoration after total hip arthroplasty with the utilisation of an intraoperative calibration gauge.

BACKGROUND: Offset and leg length (LL) restoration are critical for the achievement of a stable, well-functioning hip following total hip arthroplasty (THA). Several techniques are described in the literature, including a hip calibration gauge. We question whether meticulous preoperative planning of a specific surgical technique in combination with the utilisation of a calibration gauge can provide an accurate offset and LL restoration. METHODS: Retrospective review of 101 unilateral THAs via a posterior approach by a single surgeon. Preoperative radiographic LL and offset were radiographically calculated. Intraoperatively prior to hip dislocation a calibration gauge was used to measure LL and offset with a pin inserted into the iliac crest acting as a static referencing point. All had pelvis x-ray performed 6 weeks postoperatively. A literature review was conducted to establish average postoperative LL/offset values for statistical comparison. RESULTS: The average absolute postoperative leg-length discrepancy (LLD) was 2.51 mm compared to preoperatively 3.54 mm (p = 0.018). A total of 93.1% and 100% had LLD of ⩽5 mm and ⩽10 mm, respectively. The mean postoperative offset difference was 2.39 mm. The investigated LLD and offset results were comparable with literature data of studies utilising an intraoperative measuring device. LLD was significantly decreased when compared to a free-hand technique (LLD 4.42 mm, p < 0.001). CONCLUSION: The technique utilising preoperative templating, intraoperative offset verification together with the use of hip calibration gauge yielded accurate LLD and offset restoration as in the literature. Precise offset restoration, which often is a neglected issue, can lead to better abductor vector restoration, hip function and less pain.

Ambient theatre temperature and cement setting time in total knee arthroplasty.

BACKGROUND: Polymethylmethacrylate cement is used in total knee arthroplasty and plays a significant role in the success of the procedure. Temperature variation is known to influence cement setting time in vitro. Our aim is to evaluate the relationship between ambient theatre temperature and cement setting time in vivo. METHODS: Theatre temperature and cement setting time were prospectively recorded during 683 total knee arthroplasties over 8 years using a single cement and vacuum mixing system (Simplex with tobramycin). Setting time was defined as the time until a scalpel blade could not indent the cement surface. RESULTS: Mean temperature was 18.92°C (SD 1.16) and setting time 13.08 min (SD 1.92). A moderate inverse relationship exists between ambient temperature and setting time (Pearson's R = -0.423); however, potential setting times within a given temperature range varied considerably (<19°C: 8-19.1 min, 19-20°C: 7-18 min and >20°C: 7.5-16 min), suggesting that temperature alone cannot reliably predict setting time. CONCLUSION: Our data support the current understanding of bone cement properties in vivo and suggest that surgeons should be mindful in regards to unpredictable cement setting time and optimal theatre environment.

Prior Lumbar Spinal Fusion is Associated With an Increased Risk of Dislocation and Revision in Total Hip Arthroplasty: A Meta-Analysis.

BACKGROUND: The biomechanical relationship between the lumbar spine and the hip is well-documented. It follows that fusing the lumbar spine would have implications on the outcomes of total hip arthroplasty (THA). This study aimed to determine the effect of preexisting lumbar spinal fusion surgery on the outcomes of THA by synthesizing the available evidence via systematic review and meta-analysis. METHODS: A systematic review with meta-analysis was performed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic searches were performed in 6 different databases for studies comparing outcomes in patients after THA with or without a history of lumbar fusion. Studies were required to report at least one outcome out of dislocation, revision due to hip instability or patient-reported outcomes. RESULTS: Patients with a history of lumbar spinal fusion are at a significantly increased risk of dislocation (relative risk 2.03, P < .00001) and revision (relative risk 3.36, P = .006) after THA. Patient-reported outcomes were also poorer in patients with prior lumbar fusion compared with those without, although meta-analysis could not be performed due to heterogeneity in the outcome measure used between studies. CONCLUSION: Previous lumbar spinal fusion increases risk of dislocation and revision, and may negatively impacts patient-reported outcomes after THA. Orthopaedic surgeons should pay particular attention to these patients and could use patient-specific planning, instrumentation, and targeted counselling to optimize clinical and subjective outcomes. Future studies could clarify the impact of prior fusion on patient-reported outcomes after THA.

Total Knee Arthroplasty Using Bicruciate-Stabilized or Posterior-Stabilized Knee Implants Provided Comparable Outcomes at 2 Years: A Prospective, Multicenter, Randomized, Controlled, Clinical Trial of Patient Outcomes.

BACKGROUND: The bicruciate-stabilized (BCS) knee arthroplasty was developed to replicate normal knee kinematics. We examined the hypothesis that patients with osteoarthritis requiring total knee arthroplasty (TKA) will have better functional outcome and satisfaction with the BCS implant compared with an established posterior cruciate-stabilized implant. METHODS: This multicenter, randomized, controlled trial compared the clinical outcomes of a BCS implant against an established posterior cruciate-stabilized implant with 2-year follow-up. Of the patients awaiting primary knee arthroplasty for osteoarthritis, 228 were randomized to receive either a posterior-stabilized or BCS implant. Primary outcomes were knee flexion and Oxford Knee Score. Secondary outcomes were rate of complications and adverse events (AEs). Tertiary outcomes included Knee Society Score, University of California, Los Angeles, activity score, Patella scores, EQ-5D, 6-minute walk time, and patient satisfaction. RESULTS: Complete data were recorded for 98 posterior-stabilized implants and 97 BCS implants. Twelve patients had bilateral knee implants. There was no difference between the groups for any of the measures at either 1 or 2 years. At 2 years, knee flexion was 119 ± 0.16 and 120 ± 1.21 degrees for the posterior-stabilized and BCS implants, respectively, (mean, standard error, P = .538) and Oxford Knee Scores were 40.4 ± 0.69 and 40.0 ± 0.67 (P = .828), respectively. There were similar device-related AEs and revisions in each group (AEs 18 vs 22; P = .732; revisions 3 vs 4; P = .618). CONCLUSION: There was no evidence of clinical superiority of one implant over the other at 2 years.

The accuracy of bony resection from patient-specific guides during total knee arthroplasty.

PURPOSE: In patient-specifically instrumented (PSI) total knee arthroplasty, the correlation between the pre-operative surgical plan, accuracy of the cutting block, and intra-operative resection size is unclear. The aim of this study was to evaluate the ability to accurately execute the PSI surgical plan and to add to the merging information with respect to this technology with the hypothesis that the PSI blocks would demonstrate good accuracy with regard to the bony thickness of the resections. METHODS: One hundred and thirty TKAs using PSI (MRI/long-leg radiographs) were retrospectively analysed. All surgeries were conducted via similar surgical approach and technique, with resection performed after guide placement and alignment assessment. The bony cut thicknesses of the medial (MTP) and lateral tibial plateau (LTP), distal medial (DM), distal lateral (DL), posterior medial (PM) and posterior lateral (PL) femur were measured with a vernier calliper. The measured resection thickness was subtracted from the planned resection. Errors were defined as ≤1.5 mm (acceptable), 1.5-2.5 mm (borderline), and >2.5 mm (outliers). RESULTS: Overall, 81 (62.3 %) of the knees were free of outliers. The distal femur cut had the highest proportion of acceptable cut error with 209 of 260 total cuts acceptable (80.4 %). The tibial cuts had the lowest proportion of "acceptable" cuts (68.9 %). Tibial cuts had more outliers (33 of 260 cuts, 12.7 %) than the femur (39 of 520 cuts, 7.5 %) (p = 0.01). Pre-operative varus (n = 97) and valgus (n = 33) deformities demonstrated 7.7 % (45/482) and 13.6 % (27/198) of cuts which were outliers, respectively (p = 0.01). CONCLUSION: PSI showed only fair to moderate accuracy with 62.3 % of the knees presenting no outliers. The tibia cutting guide was less accurate than the femur. Specific attention is needed when cutting the tibia and in correction of valgus deformity. Moreover, intra-operative verifying measurements can provide feedback to the accuracy of the surgical plan. LEVEL OF EVIDENCE: IV, case series with no comparison group.

Accuracy of MRI-based vs. CT-based patient-specific instrumentation in total knee arthroplasty: A meta-analysis.

INTRODUCTION: The technical objective of total knee arthroplasty (TKA) is to restore normal mechanical parameters to the knee. Patient-specific instrumentation (PSI) was developed to streamline the operative process and improve accuracy. PSI produces individualized cutting guides based on three-dimensional models of the patient's anatomy acquired from computed-tomography (CT) or magnetic-resonance imaging (MRI). However, the superiority of one modality over the other remains unclear. Therefore, we aimed to compare the accuracy of patient-specific cutting guides produced from MRI or CT imaging methods in TKA. METHODS: Electronic databases were systematically searched using relevant keywords and MeSH terms for original-data English-language publications comparing the accuracy of CT and MRI-based PSI cutting guides in TKA. Data was extracted from the text, tables and figures of studies and meta-analysed. RESULTS: MRI-based PSI cutting guides produced a lower proportion of coronal plane outliers (>3°) with regard to overall limb mechanical axis (OR 2.75, p = 0.01). There were no significant differences between the two in terms of sagittal femoral and tibial component placement, or coronal femoral and tibial placement, or femoral component axial rotation. Tibial rotation was not analysed in the literature. CONCLUSIONS: MRI-based patient-specific cutting guides produced a lower proportion of outliers in the overall coronal alignment of the limb compared to CT, with no significant difference between the two in terms of femoral or tibial component placement. Future studies should investigate the differences in resource usage and operative time between the two to inform surgeons' decision making when choosing an ideal imaging modality for PSI TKA. STUDY DESIGN: Meta-analysis. LEVEL OF EVIDENCE: III, systematic review of cohort and comparative studies.

Aspirin as Thromboprophylaxis in Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Venous thromboembolism (VTE) comprises pulmonary embolism and deep vein thrombosis and is a complication of particular concern in lower limb arthroplasty. In recent years, aspirin has emerged as a potential alternative thromboprophylactic agent, particularly after its acceptance as a recommended agent by the American College of Chest Physicians. Aspirin is favorable due to its relative cost-effectiveness and convenience compared to novel oral anticoagulants and warfarin. However, its efficacy since its inclusion in the American College of Chest Physicians guidelines remains unclear. The present systematic review aimed to establish the efficacy of aspirin in preventing VTE in total hip and knee arthroplasty. METHODS: Electronic searches were performed using 6 databases from up to June 2015, identifying all relevant studies. Data were extracted and meta-analyzed. RESULTS: Eleven relevant studies were identified for inclusion in the present meta-analysis. The overall rate of deep vein thrombosis and pulmonary embolism in both hip and knee arthroplasty was 1.2% and 0.6%, respectively. The rate of major bleeding was 0.3%. Pooled mortality rate was 0.2%. All findings demonstrated a high and significant degree of heterogeneity. CONCLUSION: Aspirin, both alone and in multimodal approaches to thromboprophylaxis, confers a low rate of VTE, with a low risk of major bleeding complications. However, the evidence for its use is limited by the low quality of studies and variation in dose in dosing regimes. Future randomized controlled trials should investigate the efficacy of aspirin, as well as the ideal dosing protocol for its use in thromboprophylaxis in arthroplasty.

A short-term follow-up study of a surgeon-customised fully-coated hydroxyapatite femoral stem using a nation-wide joint registry.

OBJECTIVE: To compare revision rates between otherwise-identical fully-coated and proximally-coated hydroxyapatite (HA) femoral stems using a nation-wide registry. METHODS: 249 proximally-coated stems (50 µm HA) and 225 fully-coated stems (100 µm HA and 50 µm titanium) were followed over a mean of 34.9 and 23.2 months respectively. RESULTS: Four proximally-coated (rate: 1.61%) and five fully-coated stem revisions (rate: 2.20%) were reported, with no statistical difference between groups (p = 1.0, OR 0.90, 95% CI 0.20-3.97). Registry data showed no difference in performance between fully-coated and proximally-coated stems nationwide (rate: 2.22%, p = 0.82). CONCLUSION: There is no statistical difference in survival between fully-coated and proximally-coated HA prostheses in the short-term.

Early clinical and radiological results of total knee arthroplasty using patient-specific guides in obese patients.

PURPOSE: Total knee arthroplasty (TKA) is a challenging procedure in patients with a high body mass index (BMI). The aim of our study was to assess the outcome and accuracy of restoration of mechanical alignment in TKA using patient-specific guides (PSG) involving patients with high BMI. MATERIALS AND METHODS: Patients with BMI of 30 or above were enrolled in the study. The mean age of the patients was 65.15 years. The study comprised of 46 males and 54 females. Total knee arthroplasty was planned after a pre-operative MRI and long leg x-ray films using customized PSG. RESULTS: Of the 105 knees (100 patients) in the study, average BMI was 35.42 kg/m(2) (30-56). Twenty patients (20 %) had class III obesity (≥40 kg/m(2)). The average blood loss and operative time were 236.1 ml (range 50-700 ml) and 92.2 min (65-130 min), respectively. The average post-operative mechanical axis was noted to be 1.85° varus (range 4° valgus to 6° varus). Eighty-eight patients (86.27 %) had mechanical alignment within 3° of neutral. There were no adverse intraoperative events. One patient had deep infection that required a two-stage revision. The average post-operative range of motion at 1-year follow-up was 105.8° (range 80°-130°). CONCLUSION: Patient-specific guides technology restores the coronal mechanical axis reliably in obese patients without adversely affecting outcomes. Our short-term follow-up has shown favorable outcomes. Surgeons should use these customized jigs as a guide and adjust the size of components, alignment and rotation according to normal surgical principles.

Practical implications of the lumbar spine and its function on total hip arthroplasty.

Correct component placement is of significant importance to ensure optimal outcomes in total hip arthroplasty (THA). Traditionally, the Lewinnek plane has been referenced as an adequate "safe zone", formed between the anterior superior iliac spines and public tubercles to optimize acetabular orientation. However, recent evidence shows that the positioning of this plane may vary due to the biomechanical relationship between the lumbar spine and hip. Therefore, the plane acquired intraoperatively may not accurately recreate the actual functional plane and acetabular orientation encountered outside of the intraoperative environment. This review summarizes the hip-spine relationship and its implications on THA.

Bilateral symptomatic discoid medial meniscus of the knee: a case report and review of literature.

INTRODUCTION: A discoid medial meniscus is a rare pathology of the knee joint, and is even rarer when it presents bilaterally with clinical symptoms. CASE PRESENTATION: We present the case of a 38-year-old female with symptomatic bilateral discoid medial meniscus. Magnetic Resonance Imaging (MRI) showed complete discoid meniscus in one knee and incomplete, on the other side. The MRI findings were confirmed on arthroscopy, with horizontal cleavage tear in both knees. Arthroscopic partial meniscectomies of both menisci were performed. CONCLUSIONS: The patient had an excellent functional outcome at the most recent follow-up, with no recurrence of symptoms and full range of movements.

Posttraumatic incarceration of medial collateral ligament into knee joint with anterior cruciate ligament injury.

Medial collateral ligament of the knee is an important coronal stabiliser and often injured in isolation or as combination of injuries. The article reports a case of incarcerated medial collateral ligament (MCL) injury in combination with anterior cruciate ligament (ACL) injury in 20 year old male who presented to us 4 weeks after injury. Clinical examination and MRI was correlated to complete ACL tear with torn distal MCL and incarceration into the joint. Patient was taken up for ACL hamstring graft reconstruction with mini-arthrotomy and repair of the torn MCL. Patient was followed up with dedicated rehabilitation protocol with good functional results. At one year follow-up, patient exhibited full range of motion with negative Lachman, Pivot shift and valgus stress tests. This article highlights the rare pattern of MCL tear and also reviews the literature on this pattern of injury.

Verification of the Australian Orthopaedic Association National Joint Replacement Registry using a surgeon's database.

PURPOSE: To assess the completeness of registration and any discrepancies between the senior author's database and the Australian Orthopaedic Association National Joint Replacement Registry (AOA NJRR). METHODS: From 2002 to 2005, the senior author performed 231 primary total hip arthroplasty (THA) on 217 patients using the Corail femoral stem and one of the 3 types of the acetabular component: Pinnacle, ASR, or Duraloc/Option. The name of each patient was forwarded to the AOA NJRR for matching and verification. RESULTS: The AOA NJRR recorded 230 of the 231 primary THAs; all but one was matched with the senior author's database. Nine (3.9%) of them were revised by the same (n=7) or another (n=2) surgeon. Three (43%) of the 7 revision surgeries were not recorded on the AOA NJRR. One patient revised for a ceramic liner fracture was incorrectly recorded as 'wear acetabulum' in the AOA NJRR. CONCLUSION: Although the AOA NJRR achieved high registration completeness for primary THA, accuracy for revision THA was much lower.

Whip stitch versus grasping suture for tendon autograft.

PURPOSE: During tendon autograft harvest, either a grasping suture or traditional whip stitch can be used to grasp tendon prior to definitive bone fixation. Their grip strength has not, to our knowledge, been compared. This article compares a needle-free suture technique to a standard whip stitch by testing grip strength in vitro. METHODS: Twelve uniform ovine flexor tendons were prepared; six tendons with a standard, non-locking whip stitch and six tendons with a grasping suture. All the samples were tested to failure in uniaxial tension in a materials testing machine. Load/displacement curves were generated, and qualitatively assessed and peak loads were compared. RESULTS: There were no significant differences between the groups in tendon length or diameter. Modes of failure between the groups, as characterised by the load/displacement curves, were quite distinct. Peak load to failure was lower in the utility suture group (mean peak load at failure 121.28 N) than the whip stitch group (mean peak load to failure 188.82 N). All failures in the utility suture group occurred when the suture snapped. CONCLUSIONS: The grasping suture described here is weaker than a standard whip stitch but may be sufficiently strong to harvest and handle tendon autograft. A standard whip stitch remains the choice for definitive graft fixation.

The effect of sterilization on the mechanical properties of intact rabbit humeri in three-point bending, four-point bending and torsion.

Load bearing bone allografts are used to replace the mechanical function of bone that has been removed or to augment bone that has been damaged in trauma. In order to minimize the risk of infection and immune response, the bone is delipidated and terminally sterilized prior to implantation. The optimal method for bone graft sterilization has been the topic of considerable research. Recently, supercritical carbon dioxide (SCCO(2)) treatments have been shown to terminally sterilize bone against a range of bacteria and viruses. This study aimed to evaluate the effect of SCCO(2) treatment compared with two doses of gamma irradiation, on the mechanical properties of whole bone. Paired rabbit humeri were dissected and randomly assigned into either SCCO(2) control, SCCO(2) additive or gamma irradiation at 10 or 25 kGy treatment groups. The bones were mechanically tested in three-point and four-point bending and torsion, with the lefts acting as controls for the treated rights. Maximum load, energy to failure and stiffness were evaluated. This study found that SCCO(2) treatment with or without additive did not alter maximum load, energy to failure or stiffness significantly under any loading modality. Gamma irradiation had a deleterious dose dependant effect, with statistically significant decreases in all mechanical tests at 25 kGy; while at 10 kGy there were reductions in all loading profiles, though only reaching statistical significance in torsion. This study highlights the expediency of SCCO(2) treatment for bone allograft processing as terminal sterilization can be achieved while maintaining the intrinsic mechanical properties of the graft.

Practical recommendations for patient blood management and the reduction of perioperative transfusion in joint replacement surgery.

Data from the Australian Better Safer Transfusion programme show that about one-third of patients undergoing hip or knee arthroplasty receive perioperative blood transfusions, placing them at increased risk for adverse clinical outcomes. Other concerns associated with allogeneic blood transfusion include the quality of stored red cell concentrates, the cost of provision of blood and the predicted local demographics, which mean that fewer donors will need to support a greater number of recipients. In view of the multiple challenges associated with allogeneic blood transfusion and its provision, we developed practical management recommendations for perioperative bleeding in joint replacement surgery, based on available evidence and expert consensus opinion, that aim to promote a new, responsible approach to transfusion management. Key recommendations are as follows. Patients' medical health, including haemoglobin and iron levels, needs to be evaluated and optimized preoperatively. Anticoagulant and antiplatelet therapy should be stopped if possible, unless indicated for secondary cardiovascular prevention or coronary stent patency, in which case careful consideration is required. If substantial blood loss is anticipated, intraoperative management with antifibrinolytic agents is recommended for bleeding prophylaxis. Normothermia should be maintained. Pharmacological and non-pharmacological measures are recommended for post-operative thromboprophylaxis. A blood management programme should be instituted for haemodynamically stable patients.