Abstract: ABSTRACT: BACKGROUND: Effective fixation of fracture requires careful selection of a suitable implant to provide stability and durability. Implant with a feature of locking plate (LP) has been used widely for treating distal fractures in femur because of its favourable clinical outcome, but its potential in fixing proximal fractures in the subtrochancteric region has yet to be explored. Therefore, this comparative study was undertaken to demonstrate the merits of the LP implant in treating the subtrochancteric fractures by comparing its performance limits against those obtained with the more traditional implants; angle blade plate (ABP) and dynamic condylar screw plate (DCSP). Materials and Methods: Nine standard composite femurs were acquired, divided into three groups and fixed with LP (n=3), ABP (n=3)and DCSP (n=3). The fracture was modeled by a 20 mm gap created at the subtrochanteric region to experimentally study the biomechanical response of each implant under axial static and dynamic loading paradigms. To confirm the experimental findings and to understand the critical interactions at the boundaries, the synthetic femur/implant systems were numerically analyzed by constructing hierarchical finite element models with nonlinear hyperelastic properties. The predictions from the analyses were then compared against the experimental measurements to demonstrate the validity of the numeric model, and to characterize the internal load distribution in the femur and load bearing properties of each implant. RESULTS: The average measurements indicated that the constructs with ABP, DCPS and LP respectively had overall stiffness values of 70.9, 110.2 and 131.4 N/mm, and exhibited reversible deformations of 12.4, 4.9 and 4.1 mm when the applied dynamic load was 400 N and plastic deformations of 11.3, 2.4 and 1.4 mm when the load was 1000 N. The corresponding peak cyclic loads to failure were 1100, 1167 and 1600 N. The errors between the displacements measured experimentally or predicted by the nonlinear hierarchical hyperelastic model were less than 18 %. In the implanted femur heads, the principal stresses were spatially heterogeneous for ABP and DCSP but more homogenous for LP, meaning LP had lower stress concentration. CONCLUSION: When fixed with the LP implant, the synthetic femur model of the subtrochancteric fracture consistently exceeds in the key biomechanical measures of stability and durability. These capabilities suggest increased resistance to fatigue and failure, which are highly desirable features expected of implants make the LP implant potentially a viable alternative to the conventional ABP or DCSP in the treatment of the subtrochancteric femur fractures for the betterment of the clinical outcome.
Abstract: PagetâÂÂs disease is common in Western countries but is very rare in Chinese populations. Although bisphosphonate has been widely used to treat symptomatic PagetâÂÂs disease, prolonged use may be associated with insufficiency fracture. We highlight this rare case of PagetâÂÂs disease in a Chinese lady who presented with an insufficiency fracture following long-term use of bisphosphonate.
Abstract: Despite being a complex degenerative joint disease, studies on osteoarthritis (OA) suggest that its progression can be reduced by the use of hyaluronic acid (HA) or mesenchymal stem cells (MSC). The present study thus aims to examine the effects of MSC, HA and the combination of HA-MSC in treating OA in rat model. The histological observations using OâDriscoll score indicate that it is the use of HA and MSC independently and not their combination that delays the progression of OA. In conclusion, the preliminary study suggest that the use of either HA or MSCs effectively reduces OA progression better than their combined use.
Abstract: Residual deformity in resistant clubfoot is not uncommon. The "bean-shaped foot" exhibits forefoot adduction and midfoot supination and may interfere with function due to poor foot placement. For children less than 5 years of age we describe a corrective procedure combining a closing wedge cuboidal osteotomy and trans-midfoot rotation procedure without a medial opening wedge osteotomy. We retrospectively reviewed twelve patients (14 feet), mean age 4.7 years (range, 4-5 years), who had undergone the procedure to correct forefoot adduction and midfoot supination deformities. We obtained minimal access via a small lateral skin incision. Cuboid lateral wedge osteotomy was followed by transcuneiform osteotomy using a Kirschner wire as a guide under an image intensifier. The minimum followup was 2 years (mean, 2.6 years; range, 2-3.2 years). All patients had qualitative improvement in correction of adduction and supination deformities. Radiographically there was an improvement in adduction deformity, the mean anteroposterior talo-first metatarsal and calcaneo-fifth metatarsal angles improved by 28 degrees (from 40 degrees to 12 degrees ) and by 11 degrees (from 21 degrees to 10 degrees ). The supination improved by 11 degrees (from 19 degrees to 8 degrees ) and the cavus improved by 17 degrees (from 30 degrees to 13 degrees ). The short-term outcome was reliable and this combination is useful for children younger than 5 years old where the medial cuneiform ossification center remained poorly defined. LEVEL OF EVIDENCE: Level IV, therapeutic study (case series). See Guidelines for Authors for a complete description of levels of evidence.
Abstract: Regenerative medicine using stem cell therapy has sparked much interest in this 21st century not only because of the controversies that surround the ethics involving pluripotent stem cells but their potential for use in the clinic. The ability of stem cells to repair and regenerate new tissues and organs holds tremendous promise for the treatment of many serious diseases and injuries. This review provides a brief summary of the current status of research in stem cells with special emphasis on where we are in terms of the possible clinical application of stem cell therapy in orthopaedic surgery. We look at the available evidence and examine the ethical issues and considerations associated with the clinical use of stem cells.
Abstract: PURPOSE: This study was performed to assess the imaging findings in cases of parosteal osteosarcoma dedifferentiated into telangiectatic osteosarcoma. Parosteal osteosarcoma is a low-grade well-differentiated malignant tumor. Dedifferentiation into a more aggressive lesion is frequent and usually visible on imaging as a central lytic area in a sclerotic mass. Only one case of differentiation into a telangiectatic osteosarcoma has been reported. As it has practical consequences, with a need for aggressive chemotherapy, we looked for this rather typical imaging pattern. MATERIALS AND METHODS: Review of 199 cases of surface osteosarcomas (including 86 parosteal, of which 23 were dedifferentiated) revealed lesions suggesting a possible telangiectatic osteosarcoma on imaging examinations in five cases (cavities with fluid). Histology confirmed three cases (the two other only had hematoma inside a dedifferentiated tumor). There were three males, aged 24, 28, and 32. They had radiographs and CT, and two an MR examination. RESULTS: Lesions involved the distal femur, proximal tibia, and proximal humerus. The parosteal osteosarcoma was a sclerotic, regular mass, attached to the cortex. A purely lytic mass, partially composed of fluid cavities was easily detected on CT and MR. It involved the medullary cavity twice, and remained outside the bone once. Histology confirmed the two components in each case. Two patients died of pulmonary metastases and one is alive. CONCLUSION: Knowledge of this highly suggestive pattern should help guide the initial biopsy to diagnose the two components of the tumor, and guide aggressive treatment.
Abstract: Synovial chondrosarcoma is a rare soft tissue tumor that can arise from a previous synovial chondromatosis or as de novo tumor. The clinical and radiological findings of this malignancy are very similar to those of aggressive synovial chondromatosis. Confusion with other joint pathologies makes the diagnosis of synovial chondrosarcoma difficult in most of the cases. We present one recently diagnosed and treated case of synovial chondrosarcoma. The review of our hospital database revealed one more similar case. In both cases the malignancy arose from a pre-existing synovial chondromatosis. We also present a literature review emphasizing the clinical and histological findings of this rare entity.
Abstract: Although mesenchymal stem cells (MSCs) isolation from a number of tissue sources have been described, very few literatures have been reported successful isolation of adult MSCs from peripheral blood or its chondrogenic differentiation for clinical applications. The objective of this study is to isolate MSCs derived from both human bone marrow and peripheral blood and to compare their potential to undergo chondrogenesis.
Abstract: Fracture of thehumeral trochlea is usually associated with elbow dislocations or capitellar fracture.3âÂÂ5 Isolated trochlea fracture in adult is a surgical rarity as compared to its capitellar counterpart.5 This fracture is not mentioned in the standard orthopaedic textbook. It only appears sporadically in literature as a case report.2,6,8 The rarity of this fracture is probably a result of its anatomical location which is sited deep within the olecranon fossa. Therefore, there is still very little known regarding the mechanism of injury and the treatment results of this injury. Isolated fracture of the humeral trochlea was first described by Laugier in 1853 and later credited by Stimson. Thus, the trochlea fracture is also sometimes known as LaugierâÂÂs fracture.7 We would like to report two cases of isolated displaced trochlea fracture that were treated with open reduction and internal fixation using the standard (non-cannulated) Herbert screw (Zimmer, Warsaw, Indiana).
Abstract: A study to determine average knee laxity in the Malaysian population and how it affects daily living was conducted at the University Malaya Medical Centre between January and April 2004. Fifty two male and 76 female subjects were recruited for this study, all of whom were healthy volunteers with no ambulatory problems. Side to side knee laxity testing was performed using a KT-1000 arthrometer. Significant differences in knee laxity were noted among different races and between sexes. For instance, overall, Chinese and female study participants had higher kneelaxity: (left knee, 2.17 mm (SD=1.30) and right knee was 2.88 mm (SD= 1.51)). On average, the difference between knees was 0.70 ñ 1.26 mm (less than 1 mm) which is a smaller variation than reported in previous studies which suggested 3 mm. Despite finding knee laxity ranging from 0 to 8mm, no correlations were found between Lysholm, IKDC and Tegner knee outcome scores and the degree of knee laxity. No other predictors such as height, weight and age correlated with levels of knee laxity. We therefore conclude that knee laxity is a common occurrence in the normal population and is therefore not suitable as a sole predictor of knee function and should not be used as the only criteria for surgical intervention.
Abstract: Although not life-threatening, rupture of the anterior cruciate ligament (ACL) can severely impair activities of daily living and quality of life. ACL reconstruction is an accepted modality of treatment but failure rates as high as 25% have beeb reported. In view of this, we reviewed the clinicaloutcome of 33 patients who had undergone arthroscopic-assisted autogenous graft reconstruction using either patella-tendon or hamstring graft following anterior cruciate ligament (ACL) rupture in UMMC between 2000 to 2003. This study was also conducted to compare the outcome of the two different types of autogenous graft used for ACL reconstruction which are the bone-patella tendon-bone (BPB) and hamstring (HS) grafts. Patients between the ages of 17 to 48 years (mean age of 27.8 years) were evaluated at 1 to 3 years post-operatively using various clinical parameters which include functional index, subjective and objecyive scores and an objective measurement using KT 1000 arthrometer. On the overall, patients operated in our centre did well with 6% (n=2) failures reported. Both the BPB and HS groups had good to excellent results post operatively. Ninety seven percent (n=32) of the patients were able to kneel and squat with more than half of them achieving >90% single-legged hop test. Eighty eight percent of patients (n=29) achieved normal to nearly normal subjective IKDC score. The mean Lysholm score was 92.2, with 97% (n=32) scored excellent (80 points or more). More than 90% had equal or less than 2 Tegner activity-level drop. The mean KT 1000 side by side differences was 1.71mm, with 94% had less than 4mm difference. Even though the BPB group was observed to have a higher mean Lysholm score (92.6%) compared to the HS group (91.8%), they were statistically significant. The BPB group had a significantly less residual laxity with the KT 1000 side to side different of 1.1mm compared with the HS group of 1.9mm. However no correlation between laxity and any of the outcome scores were noted. In conclusion, ACL reconstruction procedures performed in UMMC have yield good to excellent short term results.
