Aims

Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre.

Aims

Pigment epithelium-derived factor (PEDF) is known to induce several types of tissue regeneration by activating tissue-specific stem cells. Here, we investigated the therapeutic potential of PEDF 29-mer peptide in the damaged articular cartilage (AC) in rat osteoarthritis (OA).

Aims

In the repair of condylar cartilage injury, synovium-derived mesenchymal stem cells (SMSCs) migrate to an injured site and differentiate into cartilage. This study aimed to confirm that histone deacetylase (HDAC) inhibitors, which alleviate arthritis, can improve chondrogenesis inhibited by IL-1β, and to explore its mechanism.

Aims

We have previously reported cryoablation-assisted joint-sparing surgery for osteosarcoma with epiphyseal involvement. However, it is not clear whether this is a comparable alternative to conventional joint arthroplasty in terms of oncological and functional outcomes.

Aims

The material and design of knee components can have a considerable effect on the contact characteristics of the tibial post. This study aimed to analyze the stress distribution on the tibial post when using different grades of polyethylene for the tibial inserts. In addition, the contact properties of fixed-bearing and mobile-bearing inserts were evaluated.

Aims

The use of frozen tumour-bearing autograft combined with a vascularized fibular graft (VFG) represents a new technique for biological reconstruction of massive bone defect. We have compared the clinical outcomes between this technique and Capanna reconstruction.

Aims

The aim of this study was to compare the results of 16S/28S rRNA sequencing with the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and synovial fluid analysis in the diagnosis of prosthetic joint infection (PJI).

This study compares the outcomes of two methods of fixation of displaced fractures of the radial neck. The 58 patients with a mean age of 38.5 years (18 to 56), were treated in a non randomised study with screws (n = 29) or a plate and screws (n = 29) according to the surgeon’s preference.

The patients were reviewed at one year. Radiographs and functional evaluations were carried out up to one year post-operatively, using the Broberg and Morrey functional evaluation score, range of movement, and assessment of complications.

The mean functional scores did not differ significantly between groups (90 (55 to 100) vs 84; 50 to 100, p = 0.09), but the mean range of forearm rotation in screw group was significantly better than in the plate group (152°; 110° to 170° vs 134°; 80° to 170°, p = 0.001). Although not statistically significant, the screw group had a lower incidence of heterotopic ossification than the plate group (n = 1) than the plated group (n = 3) and the pathology was graded as less severe.

Cite this article: Bone Joint J 2015;97-B:830–5

Summary

At the clinical CT image resolution level, there is no influence of the image voxel size on the derived finite element human cancellous bone models

Dysphagia is a common complication of anterior surgery of the cervical spine. The incidence of post-operative dysphagia may be as high as 71% within the first two weeks after surgery, but gradually decreases during the following months. However, 12% to 14% of patients may have some persistent dysphagia one year after the procedure. It has been shown that female gender, advanced age, multilevel surgery, longer operating time and severe pre-operative neck pain may be risk factors. Although the aetiology remains unclear and is probably multifactorial, proposed causes include oesophageal retraction, prominence of the cervical plate and prevertebral swelling. Recently, pre-operative tracheal traction exercises and the use of retropharyngeal steroids have been proposed as methods of reducing post-operative dysphagia.

We performed a systematic review to assess the incidence, aetiology, risk factors, methods of assessment and management of dysphagia following anterior cervical spinal surgery.

Cite this article: Bone Joint J 2013;95-B:868–73.

Embryonic chick tenocytes cultured in fixed-length three-dimensional fibrin gels synthesise a taught collagen fibril-rich extracellular matrix that closely resembles embryonic tendon (Kapacee et al., Matrix Biology, 27: 371–375, 2008). Importantly, the cells replace fibrin with parallel arrays of collagen fibrils that are able to resist pulling forces. Regenerative medicine strategies for musculoskeletal applications require the development of tissue with mechanical strength comparable to that of native tissues. How the cells generate tension is not understood and the mechanical properties and the cellular behaviour of this culture system have not been described. This project aimed to describe the morphology of cells in the tendon-like constructs and to quantitate the mechanical properties of the constructs.

Multiphoton imaging (MPI) can image deep into objects with reduced phototoxicity, allowing live-cell applications. MPI of the tendon constructs revealed that cells under tension were aligned longitudinally with the matrix. However, when tension was released the cells became rounded. The results suggested that embryonic tendon cells align along lines of force. Mechanical testing of newly-formed tendon constructs (T0), then at weekly intervals to six weeks (T7 to T42) was performed using an INSTRON^® failure-testing machine. An initial increase in ultimate tensile strength (UTS) was seen from T0 to T7 (1.023±0.031N to 1.150±1.150N, p=0.006), followed by a gradual decline at T35 to 0.350±0.043N, after which there was no further decrease. The UTS of the constructs was comparable with embryonic day 14 chick tendon. The initial increase in strength between T0 and T7 was cell dependent; constructs immersed in Triton-X 100 to remove cells were weaker than cellular constructs (1.277±0.096 versus 0.508±0.099, p< 0.001). Stress-strain plots demonstrated toe, heel, linear and failure regions that are classically observed in tendon.

The results show that embryonic tendon cells synthesise an extracellular matrix of collagen fibrils that are tensioned by the cells, and that the tendon constructs have mechanical strength comparable to in vivo generated tissue.

The research is generously supported by grants from The Wellcome Trust.

Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene.

The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R² = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart.

This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.

One of the most controversial issues in total knee replacement is whether or not to resurface the patella. In order to determine the effects of different designs of femoral component on the conformity of the patellofemoral joint, five different knee prostheses were investigated. These were Low Contact Stress, the Miller-Galante II, the NexGen, the Porous-Coated Anatomic, and the Total Condylar prostheses. Three-dimensional models of the prostheses and a native patella were developed and assessed by computer. The conformity of the curvature of the five different prosthetic femoral components to their corresponding patellar implants and to the native patella at different angles of flexion was assessed by measuring the angles of intersection of tangential lines.

The Total Condylar prosthesis had the lowest conformity with the native patella (mean 8.58°; 0.14° to 29.9°) and with its own patellar component (mean 11.36°; 0.55° to 39.19°). In the other four prostheses, the conformity was better (mean 2.25°; 0.02° to 10.52°) when articulated with the corresponding patellar component. The Porous-Coated Anatomic femoral component showed better conformity (mean 6.51°; 0.07° to 9.89°) than the Miller-Galante II prosthesis (mean 11.20°; 5.80° to 16.72°) when tested with the native patella. Although the Nexgen prosthesis had less conformity with the native patella at a low angle of flexion, this improved at mid (mean 3.57°; 1.40° to 4.56°) or high angles of flexion (mean 4.54°; 0.91° to 9.39°), respectively. The Low Contact Stress femoral component had the best conformity with the native patella (mean 2.39°; 0.04° to 4.56°). There was no significant difference (p > 0.208) between the conformity when tested with the native patella or its own patellar component at any angle of flexion.

The geometry of the anterior flange of a femoral component affects the conformity of the patellofemoral joint when articulating with the native patella. A more anatomical design of femoral component is preferable if the surgeon decides not to resurface the patella at the time of operation.

Introduction and Aims: To determine differences in metal memory, at physiological temperatures, between 6mm stainless steel and titanium rods as a function of construct failure in scoliosis surgery.

Method: Different length Ti and SST rods were contoured at room temperature with a radius of curvature of 30cm and incubated at 37±2°C. Rods were photographed biweekly over graph paper with a digital camera. The images were processed using Jandel Sigma Scan. A best-fit regression polynomial was used to calculate the average curvature. After 36 weeks, the curvature of each rod was normalised against the initial curvature and plotted against time, with a linear regression performed to assess changes in curvature, expressed as percent of change per year.

Results: Changes in both SST rods and pre-bent Ti rod were within measurement error (0.52% increase for long SST, 0.26% decrease for short SST). In contrast, both manually bent Ti rods changed markedly (decreases of 6.76% and 5.2% for long and short Ti rods respectively).

Conclusion: Continuous physiologic heat conduction may contribute to a loss of curvature in Ti rods due to memory properties. The ideal implant should retain the intended contour. Ti rods, subjected to physiologic heat, lost correction. The use of custom contoured Ti rods for the surgical correction of spinal deformities should be questioned.