The Interaction between Joint Inflammation and Cartilage Repair

BACKGROUND: Articular cartilage lesions occur frequently but unfortunately damaged cartilage has a very limited intrinsic repair capacity. Therefore, there is a high need to develop technology that makes cartilage repair possible. Since joint damage will lead to (sterile) inflammation, development of this technology has to take into account the effects of inflammation on cartilage repair. METHODS: A literature search has been performed including combinations of the following keywords; cartilage repair, fracture repair, chondrogenesis, (sterile) inflammation, inflammatory factors, macrophage, innate immunity, and a number of individual cytokines. Papers were selected that described how inflammation or inflammatory factors affect chondrogenesis and tissue repair. A narrative review is written based on these papers focusing on the role of inflammation in cartilage repair and what we can learn from findings in other organs, especially fracture repair. RESULTS: The relationship between inflammation and tissue repair is not straightforward. Acute, local inflammation stimulates fracture repair but appears to be deleterious for chondrogenesis and cartilage repair. Systemic inflammation has a negative effect on all sorts of tissue repair. CONCLUSION: Findings on the role of inflammation in fracture repair and cartilage repair are not in line. The currently widely used models of chondrogenesis, using high differentiation factor concentrations and corticosteroid levels, are not optimal. To make it possible to draw more valid conclusions about the role of inflammation and inflammatory factors on cartilage repair, model systems must be developed that better mimic the real conditions in a joint with damaged cartilage.

Orbital Wall Fracture Repair: The Results of Early and Delayed Surgery

PURPOSE: To investigate the surgical results of early and delayed repair of orbital wall fracture after multiple subgrouping of patients by time between the operation and injury. METHODS: Eighty-eight eyes of 88 patients who underwent orbital wall fracture repair from January 2002 to December 2014 and who were followed up for more than 3 months postoperatively were included in this study. We divided the 88 patients into three groups: Early surgery group (surgery within 2 weeks after the injury), slightly delayed surgery group (surgery between 3 weeks and 2 months after the injury), delayed surgery group (surgery after 2 months of the injury). Preoperative and postoperative ocular motility, diplopia, and the degree of enophthalmos were analyzed retrospectively. RESULTS: The early surgery group consisted of 30 eyes; slightly delayed surgery group, 42 eyes; and delayed surgery group, 16 eyes. The mean duration between injury and surgery was 8.6 +/- 22.5 weeks in all patients, 1.5 +/- 0.5 weeks in the early surgery group, 3.5 +/- 1.3 weeks in the slightly delayed surgery group, and 35.3 +/- 44.7 weeks in the delayed surgery group. All patients were followed up for a mean of 12.9 +/- 10.8 weeks. Gaze limitation in all directions showed improvement in all groups, with the most shown in up gaze limitation. There were no significant differences in the degree of improvement between preoperative and postoperative gaze limitation among the three groups. Enophthalmos improved as well, without any significant differences among the three groups. CONCLUSIONS: Improvement in ocular motility limitation and enophthalmos after orbital wall fracture repair did not vary significantly according to the duration between the surgery and injury. Therefore, surgical repairment even for old orbital fractures may successfully treat enophthalmos or diplopia and relieve symptoms.

Mechanical stimulation enhances osteogenesis and bone generation / 医用生物力学

Mechanical environment and intervention do have effects on both structure and function of musculoskeletal system, prevention and treatment of related disorders as well as its rehabilitation. With rapid advancement in cellular and molecular biology, biomechanics in musculoskeletal research has extended from organ and tissue level to cellular, molecular and gene level. The development of medical biomechanics promotes research and development of mechanical stimulation-based medical devices and accordingly, how mechanical stimulation can enhance osteogenesis and bone regeneration has become a hot basic and applied research area in orthopaedics. The Journal of Medical Biomechanics has published a series of basic and applied research work on potentials of biomedical stimulations for musculoskeletal systems. In this issue, the Journal specifically selected a few original efficacy and mechanistic research on mechanical stimulation for enhancing osteogenesis and bone regeneration in challenging osteoporotic fracture repair. Such efforts would help to facilitate more clinical orientated scientific research.

A Case of Orbital Mucocele Lined With Two Types of Epithelial Cells After Orbital Wall Fracture Repair

PURPOSE: The authors report a case of orbital mucocele lined with two types of histological epithelial cells developed after repair of the orbital wall fractures. CASE SUMMARY: A 53-year-old man presented with proptosis of the left eye for two years. The patient had a history of left orbital inferomedial wall fracture repair ten years earlier at a different hospital. Examination revealed 4 mm proptosis and superior globe displacement of the left eye. Restriction of left ocular movements on elevation, depression and adduction were observed. A computed tomography scan demonstrated a large, non-enhancing, cystic tumor in the left inferior orbit with the inferior and medial wall displaced toward the paranasal sinus. An orbital cystic tumor was excised with the removal of previously-inserted orbital implant via a transconjunctival and transcaruncular approach. The inferior, and medial orbital walls were reconstructed using a MEDPOR(R) TITAN(TM) implant. The initial pathologic diagnosis was epidermal cyst. Histopathologic re-review revealed an orbital cyst lined with both stratified squamous epithelium and pseudostratified ciliated columnar epithelium, thus diagnosis was changed to orbital mucocele. Proptosis and restriction in ocular motility improved postoperatively. CONCLUSIONS: Mucocele formation should be considered in patients in whom a cyst developed after orbital fracture repair.

Two Cases of Mucocele After Orbital Fracture Repair

PURPOSE: We report two cases of mucocele formation after medial orbital wall fracture repair with an alloplastic implant. CASE SUMMARY: A 61-year-old man with a history of a medial orbital wall fracture repaired with an alloplastic implant five years earlier presented with a several-month history of left proptosis without diplopia, pain, or lid edema. A 55-year-old man with a history of a medial orbital wall fracture repaired with an alloplastic implant seven years prior, presented with a five.year history of left proptosis with diplopia. Computed tomography (CT) scans revealed a large cyst on the orbital medial wall, which surrounded the alloplastic implant and had no definite enhancement. The patients underwent orbital surgery to remove both the cyst and implant. Histologic examination of the cyst revealed a capsule lined with ciliated pseudostratified columnar epithelium. Both patients had an uncomplicated postoperative course with resolution of the proptosis. CONCLUSIONS: For cases that present with late proptosis after orbital fracture repair, mucocele formation should be included in the differential diagnosis.

Alloxan-induced diabetes delays repair in a rat model of closed tibial fracture

A closed fracture was performed on the left tibia of 3-month-old Wistar rats weighing 250 to 350 g that were either healthy (N = 24) or made diabetic with alloxan (N = 24) to investigate the effect of alloxan-induced diabetes on the course of bone fracture healing. Histomorphometric analysis of the fracture site was performed at 7, 14, 25, and 35 days. After 7 days, diabetic rats had significantly less cartilage (P = 0.045) and greater fibrous connective (P = 0.006) tissue formation at the fracture site compared to controls. In contrast, marked callus formation was seen in diabetic rats with significant osteogenesis (P = 0.011, P = 0.010, P = 0.010, respectively, for 14, 25, and 35 days) and chondrogenesis (P = 0.028, P = 0.033, P = 0.019) compared to controls. Radiographic analysis revealed a displaced fracture with poor bone fragment alignment and delayed consolidation at these times in the diabetic group. The levels of alkaline phosphatase were significantly higher in diabetic rats at 25 days (P = 0.009). These results suggest that the initial excessive formation of fibrous connective tissue associated with delay in chondrogenesis and osteogenesis may not provide suitable stability of the fractured site, contributing to the inappropriate alignment of fragments and an increase in the volume of callus in later stages of repair. The resulting displaced fracture in diabetic rats requires long periods for remodeling and complete bone consolidation.

Achievements and Prospects for Nonunion (review) / 中国康复理论与实践

@#Nonunion of longbones is a significant consequence in treating fractures, which is not easy to treat. Thes reviewed the basic knowledge and main progress regarding the cause, pathogenesis, pathophysiology of nonunion, and the methods that may be applied to the treatment of nonunion especially those non-operative one.