Articular cartilage has poor repair potential and the tissue formed is mechanically incompetent. Mesenchymal stromal cells (MSCs) show chondrogenic properties and the ability to re-grow cartilage, however a viable human model for testing cartilage regeneration and repair is lacking. Here, we describe an ex vivo pre-clinical femoral head model for studying human cartilage repair using MSCs.

Human femoral heads (FHs) were obtained following femoral neck fracture with ethical permission/patient consent and full-depth cartilage wells made using a 3mm biopsy punch. Pancreas-derived mesenchymal stromal cells (P-MSC) were prepared in culture media at ~5000 cells/20µl and added to each well and leakage prevented with fibrin sealant. After 24hrs, the sealant was removed and medium replaced with StemPro^TM chondrogenesis differentiation medium. The FHs were incubated (37^oC;5% CO₂) for 3wks, followed by a further 3wks in standard medium with 10% human serum with regular medium changes throughout. Compared to wells with medium only, A-MSCs produced a thin film across the wells which was excised en-block, fixed with 4% paraformaldehyde and frozen for cryo-sectioning.

The cell/tissue films varied in thickness ranging over 20-440µm (82±21µm; mean±SEM; N=3 FHs). The thickness of MSC films abutting the cartilage wells was variable but generally greater (15-1880µm) than across the wells, suggesting an attachment to native articular cartilage. Staining of the films using safranin O (for glycosaminoglycans; quantified using ImageJ) was variable (3±8%; mean±SEM; N=3) but in one experiment reached 20% of the adjacent cartilage. A preliminary assessment of the repair tissue gave an O'Driscoll score of 10/24 (24 is best).

These preliminary results suggest the ex vivo femoral head model has promise for studying the capacity of MSCs to repair cartilage directly in human tissue, although optimising MSCs to produce hyaline-like tissue is essential.

Supported by the CSO (TCS/17/32).

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone.

Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging.

Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9-71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%).

The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration.

Valgus unloader knee braces are a conservative treatment option for medial compartment knee osteoarthritis (OA). These braces are designed to reduce painful, and potentially injurious compressive loading on the damaged medial side of the joint through application of a frontal-plane abduction moment. While some patients experience improvements in pain, function, and joint loading, others see little to no benefit from bracing [1]. Previous biomechanical studies investigating the mechanical effectiveness of bracing have been limited in either their musculoskeletal detail [2] or incorporation of altered external joint moments and forces [3]. The first objective was to model the relative contributions of gait dynamics, muscle forces, and the external brace abduction moment to reducing medial compartment knee loads. The second objective was to determine what factors predict the effectiveness of the valgus unloading brace.

Seventeen people with knee OA (8 Female age 54.4 +/− 4.2, BMI 30.00 +/− 4.0 kg/m², Kellgren-Lawrence range of 1–4 with med. = 3) and 20 healthy age-matched controls participated in this study which was approved by the institutional ethics review board. Subjects walked across a 20m walkway with and without a Donjoy OA Assist knee brace while marker trajectories, ground reaction forces, and lower limb electromyography were recorded. The external moment applied by the brace was estimated by multiplying the brace deformation by is pre-determined brace-stiffness. For each subject, a representative stride was selected for each brace condition. A generic musculokeletal model with two legs, a torso, and 96 muscles was modified to include subject-specific frontal plane alignment and medial and lateral contact locations [4]. Muscle forces, and tibiofemoral contact forces were estimated using static optimization [4]. We defined brace effectiveness as the difference in the peak medial contact force between the braced and the unbraced conditions. A stepwise regression analysis was performed to predict brace effectiveness based on: X-ray frontal plane alignment, medial joint space, KL grade, mass, WOMAC scores, unbraced walking speed, trunk, hip and knee joint angles and moments.

The OA Assist brace reduced medial joint loading by approximately 0.1 to 0.2 BW or roughly 10%, during stance. This decrease was primarily due to the external brace abduction moment, and not changes in gait dynamics, or muscle forces. The brace effectiveness could be predicted (R²=0.77) by the KL grade, and the magnitude of the hip adduction moment in early stance (unbraced). The brace was more effective for those that had larger hip adduction moments and for those with more severe OA.

The valgus knee brace was found to reduce the medial joint contact force by approximately 10% as estimated using a musculoskeletal model. Bracing resulted in a greater reduction in joint contact force for those who had more severe OA while still maintaining a hip adduction moment similar to that of healthy controls.

This protocol describes a pragmatic multicentre randomised controlled trial (RCT) to assess the clinical and cost effectiveness of arthroscopic and open surgery in the management of rotator cuff tears. This trial began in 2007 and was modified in 2010, with the removal of a non-operative arm due to high rates of early crossover to surgery.

Cite this article: Bone Joint Res 2014;3:155–60.

Adequate range of knee motion is critical for successful total knee arthroplasty. While aggressive physical therapy is an important component, manipulation may be a necessary supplement. There seems to be a lack of consensus with variable practices existing in managing stiff postoperative knees following arthroplasty. Hence we did a postal questionnaire survey to determine the current practice and trend among knee surgeons throughout the United Kingdom.

A postal questionnaire was sent out to 100 knee surgeons registered with British Association of Knee Surgeons ensuring that the whole of United Kingdom was well represented. The questions among others included whether the surgeon used Manipulation Under Anaesthaesia (MUA) as an option for stiff postoperative knees; timing of MUA; use of Continuous Passive Motion (CPM) post-manipulation.

We received 82 responses. 46.3% of the respondents performed MUA routinely, 42.6% sometimes, and 10.9% never. Majority (71.2%) performed MUA within 3 months of the index procedure. 67.5% routinely used CPM post-manipulation while 7.3% of the respondents applied splints or serial cast post MUA. 41.5% of the surgeons routinely used Patient Controlled Analgaesia +/− Regional blocks. Majority (54.8%) never performed open/arthroscopic debridement of fibrous tissue for adhesiolysis.

Knee manipulation requires an additional anaesthetic and may result in complications such as: supracondylar femur fractures, wound dehiscence, patellar tendon avulsions, haemarthrosis, and heterotopic ossification. Moreover studies have shown that manipulation while being an important therapeutic adjunct does not increase the ultimate flexion that can be achieved which is determined by more dominant factors such as preoperative flexion and diagnosis. Manipulation should be reserved for the patient who has difficult and painful flexion in the early postoperative period.

Background

A wide array of measures has been developed to assess the role of psychological factors in the development and persistence of pain. Yet there is likely to be considerable conceptual overlap between such measures, and consequently a lack of clarity about the importance of psychological factors.

Background

People with back pain often experience long-term pain with recurrences and fluctuations. However, few studies have considered which factors predict long-term outcomes.

The aim of this study was to examine the effects of cement in total knee arthroplasty on markers of inflammation and endothelial dysfunction, as surrogate markers for enhanced risk of vascular disease or precipitation of acute vascular events post-operatively.

A total of 36 patients were recruited, with 18 in each of the cemented and uncemented groups. Both groups were matched for age, sex and body mass index.

Venous blood samples were taken pre-operatively, day 1 and day 7 post-operatively. Serum levels of interleukin 6 (IL6), tumour necrosis factor (TNF□?, e-selectin, Von willebrand factor (vWF), tissue plasminogen activator (tPA) and soluble CD40 ligand were analysed. Also, real time analysis of the expression of CD40 and CD14/CD42a aggregates on monocytes was carried out using flow cytometry. Patients were excluded from the study if there were signs of either superficial or deep infection.

The only variable to demonstrate a significant difference between the two groups was the CD1442a count. There was a significant difference in the first 24 hours (p=0.00) and from day 1 to day 7 (p=0.02)

Our study suggests that the use of bone cement causes a significant rise in CD1442a count which has been linked to atherothrombosis and acute coronary syndromes. These changes may explain the increased incidence of venous thrombosis and thromboembolism post-operatively. However more research required in this field to delineate the exact pathways involved.

Infection of human cartilage with HIV in vivo has not previously been reported. Specimens of articular cartilage taken at postmortem from ten patients who were HIV-positive were examined. Two had AIDS and eight were believed to have stage-2 disease.

The standard polymerase chain reaction (PCR) protocol was modified to allow semiquantitative analysis of the samples. Oligonucleotide primers labelled with ³²P gamma-ATP were used to detect a segment of HIV DNA and a control DNA gene segment (HLA genome) to estimate the ratio of infected cells. The ³²P-labelled PCR products were separated on acrylamide gels and visualised directly by autoradiography and computer densitometry.

Infection of human cartilage in vivo was demonstrated in nine of the ten samples in which the PCR analysis was positive. The other did not react sufficiently to produce detectable radiolabelled PCR product despite repeated DNA digestion and extraction. Cartilage infected with HIV could be a potential source of HIV when used in operations.