Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome. The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010. The majority of patients had several interim scores performed at varying intervals. The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 486 mm2 (range 64 to 2075 mm2). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites. 30% failed following this procedure at a mean time of 72 months. 52% patients stated a marked improvement in their functional outcomes within the first two years. 49% stated an excellent result following their procedure. High failure rate was noted in those with previous cartilage regenerative procedures, transplants occurring on the patella, particularly if involving multifacets. Multiple site cartilage transplantation was also associated with a high failure rate. Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure

Several bisphosphonates are now available for the treatment of osteoporosis. Porous hydroxyapatite/collagen (HA/Col) composite is an osteoconductive bone substitute which is resorbed by osteoclasts. The effects of the bisphosphonate alendronate on the formation of bone in porous HA/Col and its resorption by osteoclasts were evaluated using a rabbit model. Porous HA/Col cylinders measuring 6 mm in diameter and 8 mm in length, with a pore size of 100 μm to 500 μm and 95% porosity, were inserted into a defect produced in the lateral femoral condyles of 72 rabbits. The rabbits were divided into four groups based on the protocol of alendronate administration: the control group did not receive any alendronate, the pre group had alendronate treatment for three weeks prior to the implantation of the HA/Col, the post group had alendronate treatment following implantation until euthanasia, and the pre+post group had continuous alendronate treatment from three weeks prior to surgery until euthanasia. All rabbits were injected intravenously with either saline or alendronate (7.5 μg/kg) once a week. Each group had 18 rabbits, six in each group being killed at three, six and 12 weeks post-operatively. Alendronate administration suppressed the resorption of the implants. Additionally, the mineral densities of newly formed bone in the alendronate-treated groups were lower than those in the control group at 12 weeks post-operatively. Interestingly, the number of osteoclasts attached to the implant correlated with the extent of bone formation at three weeks. In conclusion, the systemic administration of alendronate in our rabbit model at a dose-for-weight equivalent to the clinical dose used in the treatment of osteoporosis in Japan affected the mineral density and remodelling of bone tissue in implanted porous HA/Col composites

Purpose. to evaluate the kinematics of a knee with a polyurethane meniscal scaffold for partial meniscus defect substitution during flexion under weightbearing conditions in an upright MRI. In addition, radial displacement and the surface of the scaffold was compared to the normal meniscus. Materials and Methods. One cadaver with a normal lateral meniscus and medial scaffold in the left knee and with a normal medial meniscus and lateral scaffold in the right knee. The scaffolds were implanted to substitute a 3 cm meniscus defect in the posterior horn. The cadaver was scanned in an 0,7T open MRI with a range of motion from 0-30-60-90 to hyperflexion. Kinematics were evaluated on sagittal images by the following two parameters: the position of the femoral condyle, identified by the centre of its posterior circular surface, which is named the flexion facet centre (FFC), and the point of closest approximation between the femoral and tibial subchondral plates, the contact point (CP). Both were identified in relation to the posterior tibial cortex. The displacement, measured on coronal images, is defined as the distance between the tibial plateau and the outer edge of the meniscus. The surface was also measured on coronal slices and contains the triangular surface of the meniscus. Results. Medially from 0 degrees to hyperflexion the FFC does not move anteroposteriorly. Laterally the FFC moves 12 mm backwards. The CP moves 15 mm backwards both lateral and medial. The lateral femoral condyle does roll-back with flexion but the medial does not, so the femur rotates externally around a medial centre. By contrast, both medial and lateral contact points move back, roughly in parallel, from 0 degrees to hyperflexion. The kinematics of the involved compartment is not influenced by the presence of the scaffold compared to the controlateral normal compartment. The radial displacement remains stable during full flexion: both the normal and scaffold meniscus have no different (p > 0,05) position. Both for the normal and the scaffold meniscus there is no difference (p > 0,05) in surface; there is no compression of the meniscus during flexion. Conclusion. The polyurethane implant, indicated for partial meniscus defect substitution, has no effect on the normal kinematics of the knee. Additionally, the degree of flexion has no effect on the external displacement, the surface and compressibility of both the implanted scaffold and the meniscus

Aims

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

Coronal plane fractures of the posterior femoral condyle, also known as Hoffa fractures, are rare. Lateral fractures are three times more common than medial fractures, although the reason for this is not clear. The exact mechanism of injury is likely to be a vertical shear force on the posterior femoral condyle with varying degrees of knee flexion. These fractures are commonly associated with high-energy trauma and are a diagnostic and surgical challenge. Hoffa fractures are often associated with inter- or supracondylar distal femoral fractures and CT scans are useful in delineating the coronal shear component, which can easily be missed. There are few recommendations in the literature regarding the surgical approach and methods of fixation that may be used for this injury. Non-operative treatment has been associated with poor outcomes. The goals of treatment are anatomical reduction of the articular surface with rigid, stable fixation to allow early mobilisation in order to restore function. A surgical approach that allows access to the posterior aspect of the femoral condyle is described and the use of postero-anterior lag screws with or without an additional buttress plate for fixation of these difficult fractures.

Cite this article: Bone Joint J 2013;95-B:1165–71.

Controversy continues to surround the management of patients with an open fracture of the lower limb and an associated vascular injury (Gustilo type IIIC). This study reports our 15-year experience with these fractures and their outcome in 18 patients (15 male and three female). Their mean age was 30.7 years (8 to 54) and mean Mangled Extremity Severity Score (MESS) at presentation was 6.9 (3 to 10). A total of 15 lower limbs were salvaged and three underwent amputation (two immediate and one delayed). Four patients underwent stabilisation of the fracture by external fixation and 12 with an internal device. A total of 11 patients had damage to multiple arteries and eight had a vein graft. Wound cover was achieved with a pedicled flap in three and a free flap in six. Seven patients developed a wound infection and four developed nonunion requiring further surgery. At a mean follow-up of five years (4.1 to 6.6) the mean visual analogue scale for pain was 64 (10 to 90). Depression and anxiety were common. Activities were limited mainly because of pain, and the MESS was a valid predictor of the functional outcome. Distal tibial fractures had an increased rate of nonunion when associated with posterior tibial artery damage, and seven patients (39%) were not able to return to their previous occupation.

Intramedullary tibial nailing was performed in ten paired cadavers and the insertion of a medial-to-lateral proximal oblique locking screw was simulated in each specimen. Anatomical dissection was undertaken to determine the relationship of the common peroneal nerve to the cross-screw.

The common peroneal nerve was contacted directly in four tibiae and the cross-screw was a mean of 2.6 mm (1.0 to 10.7) away from the nerve in the remaining 16. Iatrogenic injury to the common peroneal nerve by medial-to-lateral proximal oblique locking screws is therefore a significant risk during tibial nailing.