Bone graft substitutes: past, present, future.

Bone grafts are necessary to provide support, fill voids, and enhance biologic repair of skeletal defects. They are used by orthopaedic surgeons, neurosurgeons, craniofacial surgeons, and periodontists. Bone harvested from donor sites is the gold standard for this procedure. It is well documented that there are limitations and complications from the use of autograft, including the limited quantity and associated chronic donor site pain. Despite the increase in the number of procedures that require bone grafts, there has not been a single ideal bone graft substitute Scientists, surgeons, and medical companies, thus, have a tremendous responsibility to develop biologic alternatives that will enhance the functional capabilities of the bone graft substitute, and potentially reduce or eliminate the need for autograft. This article is an attempt to review the past and existing bone graft substitutes, and future directions of research. The historical data was extracted after thorough review of the literature. The data for the current concepts and future directions was compiled from the Internet, and from direct correspondence with medical companies. Since many products are undergoing clinical trials, and are yet not commercially available, their data cannot be found in literature. The main purpose of this article is to give the reader an idea about the existing market products and products likely to be available in near future.

Prevalence of short segments of specialized columnar epithelium in distal esophagus: association with gastroesophageal reflux.

BACKGROUND AND AIMS: Recent studies have reported high prevalence rates of short segments of specialized columnar epithelium (SCE) in the distal esophagus. The association of SCE with gastroesophageal reflux disease is not well established. We studied the prevalence and associations of short segments of SCE in the distal esophagus amongst Indians. METHODS: 271 patients (mean age 36 [14] y; 160 men) undergoing diagnostic upper gastrointestinal endoscopy were interviewed regarding symptoms of gastroesophageal reflux, and history of medications, smoking or chewing tobacco and alcohol ingestion. At endoscopy, presence and grade of esophagitis and hiatus hernia were recorded. One biopsy each was taken from the squamocolumnar junction and 2 cm proximal to it. Biopsies were stained with hematoxylin/eosin and alcian blue/periodic acid-Schiff. The pathologist was blinded to the clinical and endoscopic data. RESULTS: Short segments of SCE in the distal esophagus were present in 16/271 (6%; CI 5.03-6.97) patients. Increasing age (p<0.01), and endoscopic (p<0.01) and histologic (p<0.001) esophagitis were associated with its presence, whereas symptoms of gastroesophageal reflux, smoking, tobacco chewing, use of alcohol or non-steroidal anti-inflammatory drugs, and hiatus hernia were not. One patient with SCE had dysplasia. CONCLUSION: Prevalence of short segments of SCE in the distal esophagus amongst Indians is low and is usually associated with inflammation in the esophagus.

Micrococcal endophthalmitis following extracapsular cataract extraction with foldable silicone intraocular lens implantation.

A case of postoperative endophthalmitis caused by micrococci, after phacoemulsification and foldable silicone intraocular lens (IOL) implantation is reported.

Intraocular cilia associated with perforating injury.

PURPOSE: To report a case series of penetrating injury complicated by occurrence of intraocular cilia. METHODS: Retrospective analysis of charts of 11 eyes of 11 patients with penetrating injury and intraocular cilia, presenting between September 1978 and November 1998. Ten eyes underwent surgery for trauma-related problems such as cataract, vitritis, retinal detachment etc., at which time intraocular cilia were removed. One eye did not have surgery and continues to harbour cilia at the posterior perforation site. RESULTS: Metallic wire was responsible for injury in 6 of 11 eyes with intraocular cilia. Five eyes had significant intraocular inflammation. The cilia were located in the anterior segment in 4 eyes; in the posterior segment in 6 eyes and in both in one eye. At the last follow up, 72.7% had 6/18 or better vision. Poor vision in the rest was due to recurrent retinal detachment (2 eyes) and macular scarring (1 eye). CONCLUSION: Intraocular cilia are more commonly associated with injury by a metallic wire. The presentation and management of an injured eye does not seem to be influenced by the presence of cilia in the eye.

pH-adjusted periocular anaesthesia for primary vitreoretinal surgery.

PURPOSE: To evaluate the efficacy of pH-adjusted bupivacaine in conjunction with medial orbital periconal block (periocular anaesthesia). METHODS: Sixty consecutive patients undergoing primary vitreoretinal surgery were enrolled prospectively. RESULTS: Adequate anaesthesia and akinesia with no intraoperative supplementation was achieved in 53 eyes (88.3%). Factors influencing intraoperative supplementation were combined vitrectomy with scleral buckling (p = 0.005) and duration of surgery of more than 2 hours (p = 0.001). No ocular or systemic complication resulted. CONCLUSION: pH-adjusted periocular anaesthesia is safe and effective in patients undergoing primary vitreoretinal surgery.

Bisected macula following retrobulbar steroid injection.

A case of bilateral accidental globe penetration during administration of retrobulbar steroid for bilateral optic neuritis is discussed. One eye with bisected macula was managed successfully by vitrectomy, internal gas tamponade, and postoperative laser to the edges of the retinal tear. The fellow eye was blind due to central retinal artery occlusion.

High frequency of bacteremia with endoscopic treatment of esophageal varices in advanced cirrhosis.

OBJECTIVES: The fregency of bacteremia after endoscopic variceal band ligation (EVL) is reported to be lower when compared to that after endoscopic variceal sclerotherapy (EVS). However, there are conflicting reports on the infectious sequelae after EVL. AIM: To compare the frequency on bacteremia and infectious sequelae after EVL and EVS in patients with cirrhosis of liver. METHODS: Bacteremia and infectious sequelae were studied in 32 sessions of EVL in 18 cirrhotic patients (Child-Pugh class A-6, B-5, C-7), 30 sessions of EVS in 22 cirrhotic patients (Child-Pugh class A-2, B-5, C-15) and 14 diagnostic upper gastrointestinal endoscopies. Blood cultures were collected before, during and 30 minutes after the procedure. Patients were observed for infectious sequelae during subsequent hospitalization. RESULTS: Before the procedure, bacteremia was present in 7/62 (11%) sessions. Significant bacteremia during and 30 min post-procedure developed in 8/32 (25%) and 12/30 (40%) of EVL and EVS sessions, respectively (p = ns), and in 1/14 (7%) upper gastrointestinal endoscopy sessions. There was more frequent bacteremia with severe liver disease (Child-Pugh class A-0/6, B-1/5. C-7/21; p = 0.09) in the EVL but not in the EVS group (Child-Pugh class A-1/3, B-2/5, C-9/22; p = ns). The incidence was higher with emergency sclerotherapy compared to elective sclerotherapy (6/8 [75%] vs 6/22 [27%]; p <0.01). One patient in the EVS group developed spontaneous bacterial peritonitis. CONCLUSIONS: Bacteremia occurs frequently following EVL and EVS in patients with advanced liver diseases. In the EVS group it is more common after emergency sclerotherapy. This bacteremia is rarely associated with significant infectious sequelae.

Subconjunctival cysts following silicone oil injection: a clinicopathological study of five cases.

PURPOSE: To study the occurrence, risk factors and management of subconjunctival cysts formed following the use of intraocular silicone oil as a tamponade. METHODS: We analyzed 5 cases of single and multioculated subconjunctival oil cysts between 1986 and 1996. RESULTS: Cysts were observed 15 days to 4 months following silicone oil injection. Clinically they showed minimal inflammatory signs but histopathology of removed cysts showed emulsified silicone oil globules with chronic inflammatory cellular infiltration. CONCLUSION: Though silicone oil is considered to be nontoxic, it can cause chronic inflammation when spilled into the subconjunctival space.

Transthyretin (prealbumin) in eye structures and variation of vitreous-transthyretin in diseases.

PURPOSE: To evaluate the presence of transthyretin (TTR, prealbumin) a protein which binds retinol to retinol-binding protein in various ocular tissues and to study its quantitative changes in the vitreous humor in various diseases. METHOD: Estimation of TTR was done by electrophoresis of 10 mg protein in each sample of tears, aqueous humor, vitreous, retina, and lens by an Imaging Densitometer using prealbumin as the standard. RESULTS: TTR was present in all the eye structures except the lens and tear. The retina and the vitreous had relatively higher amounts of TTR compared with aqueous. The identity of TTR was confirmed by immuno-electrophoresis using anti-human TTR. Two bands in SDS electrophoresis revealed that this protein is a heterodimer. There was a significant decrease in vitreous TTR in diabetes with hypertension and increase in one case each of diabetes with hypertension associated with leukaemia or carcinoma with hepato-splenomegaly. CONCLUSION: Vitreous TTR is probably from retina and retinal pigment epithelium. The level of vitreous TTR is likely to have diagnostic significance in some retinal diseases.

Ultrasound Biomiscroscopy in the diagnosis and management of cyclodialysis clefts.

PURPOSE: To report the role of Ultrasound Biomicroscopy (UBM) as a tool in the diagnosis and management of cyclodialysis clefts. METHODS: Six eyes of 6 patients with hypotony and suspected or diagnosed cyclodialysis clefts underwent UBM evaluation. Post-treatment UBM was performed in four eyes to assess the effect of the treatment. RESULTS: Cyclodialysis clefts were accurately diagnosed and delineated in 6 eyes by UBM. Complete closure was documented after treatment in 3 eyes, and a residual cleft in one eye. These findings were compared to gonioscopic findings. CONCLUSIONS: UBM is a safe, accurate and noninvasive diagnostic tool in the diagnosis of cyclodialysis clefts and is of particular use when other conventional methods of diagnosis are inconclusive.

Bilioma secondary to choledocholithiasis.

Bilioma secondary to choledocholithiasis is rare. We report a patient in whom a large common bile duct stone was responsible for leak from the infraduodenal segment of the bile duct. Choledochotomy with extraction of stone followed by T-tube drainage of the bile duct and evacuation of the bilioma resulted in complete recovery.

Long-term anti-inflammatory drug use and Helicobacter pylori infection: a clinical, endoscopic and histological study.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori are independent risk factors for gastroduodenal damage and peptic ulcer. OBJECTIVE: To study the frequency and effect of H pylori infection on gastroduodenal mucosa in patients on long-term NSAID use. METHODS: A total of 125 subjects were studied: 65 patients (Group 1) on NSAID therapy (> 6 months), 30 patients (Group 2) with arthritic disorders prior to starting NSAID therapy, and 30 healthy volunteers (Group 3). Dyspeptic symptoms were evaluated using a questionnaire. All patients underwent endoscopy and antral and duodenal biopsies were obtained to assess the extent of gastroduodenal damage and H pylori status. RESULTS: H pylori infection was less frequent in Group 1 (37%) compared to Group 2 (57%, p = ns) and 3 (60%, p < 0.05). Among Group 1 patients, H pylori infection did not increase the risk of gastroduodenal damage (52% vs 45%) or ulceration (32% vs 27%). Group 1 patients with H pylori infection were more likely to be symptomatic (48% vs 27%) and have chronic active gastritis (76% vs 12%) and chronic active duodenitis (68% vs 5%). Gastric metaplasia was seen only in patients with H pylori infection, chronic active gastritis and duodenitis. Chemical gastritis was observed more commonly in Group 1 (34% vs 3%) compared to Group 2; its was not seen in Group 3. H pylori infection was less commonly observed in patients with chemical gastritis (8% vs 50%). CONCLUSION: Patients on long-term NSAIDs are not at increased risk of H pylori infection. Presence H pylori infection is not associated with increased risk of gastroduodenal damage in these patients. H pylori infection correlated with presence of chronic active gastritis, and NSAID with presence of chemical gastritis.

Endophthalmitis caused by anaerobic bacteria.

A retrospective analysis of 22 patients who underwent pars plana vitrectomy for endophthalmitis and had culture-proven anaerobic bacteria, was done. Elimination of infection with attached retina and recovery of ambulatory vision > or = 2/60 were considered as anatomic success and functional success, respectively. Mean follow-up period was 12.7 months (range, 2 to 48 months). Anatomic success was attained in 14 (63.6%) eyes and functional success in 12 (54.6%) eyes. A poor preoperative visual acuity was found to be associated with poor functional outcome (p < 0.046). In endophthalmitis, a routine anaerobic culture of intraocular specimen is recommended.

Retinal detachment secondary to ocular perforation during retrobulbar anaesthesia.

The clinical characteristics and the retinal breaks associated with rhegmatogenous retinal detachments secondary to accidental globe perforation during local infiltration anaesthesia in five highly myopic eyes are presented. Retinal detachment was total with variable proliferative vitreoretinopathy. The pattern of retinal breaks was rather typical and predictable. Management involved vitreous surgery with internal tamponade by silicone oil in four eyes and perfluoropropane gas in one eye. At the last follow-up, all eyes had attached retina. One eye did not recover useful vision due to possible concurrent optic nerve damage.