Shalimar Abdullah

Giant Cell Tumor of the Tendon Sheath in the Knee of an 11-year-old Girl

Giant cell tumors are commonly found over the flexor tendon sheath of the hand and wrist. However, giant cell tumors in the knee joint are rare, especially in children. We report an interesting case of an 11-year-old girl who presented with a painful lump on her right knee that enlarged over time. Clinically, she had fullness over the anterolateral part of her knee. Magnetic resonance imaging revealed an encapsulated mass inferior to the patella. The tumor measured 3 x 3.5 x 1.5 cm. Histopathological findings confirmed that it was a tenosynovial giant cell tumor. Because of initial mild symptoms, there was a delay of 2 years from the initial symptoms until tumor excision. Her follow-up period was 35 months, and her health to date is excellent with no recurrence. We believe that reporting this rare case will help clinicians update their knowledge on possible causes of lumps in the knee, and avoid diagnostic delay. It could also prove to be beneficial in arriving at a diagnosis in future cases.

Neural‐differentiated mesenchymal stem cells incorporated into muscle stuffed vein scaffold forms a stable living nerve conduit

Autologous nerve grafts to bridge nerve gaps have donor site morbidity and possible neuroma formation resulting in development of various methods of bridging nerve gaps without using autologous nerve grafts. We have fabricated an acellular muscle stuffed vein seeded with differentiated mesenchymal stem cells (MSCs) as a substitute for nerve autografts. Human vein and muscle were both decellularized by liquid nitrogen immersion with subsequent hydrolysis in hydrochloric acid. Human MSCs were subjected to a series of treatments with a reducing agent, retinoic acid, and a combination of trophic factors. The differentiated MSCs were seeded on the surface of acellular muscle tissue and then stuffed into the vein. Our study showed that 35–75% of the cells expressed neural markers such as S100b, glial fibrillary acidic protein (GFAP), p75 NGF receptor, and Nestin after differentiation. Histological and ultra structural analyses of muscle stuffed veins showed attachment of cells onto the surface of the acellular muscle and penetration of the cells into the hydrolyzed fraction of muscle fibers. We implanted these muscle stuffed veins into athymic mice and at 8 weeks post‐implantation, the acellular muscle tissue had fully degraded and replaced with new matrix produced by the seeded cells. The vein was still intact and no inflammatory reactions were observed proving the biocompatibility and biodegradability of the conduit. In conclusion, we have successfully formed a stable living nerve conduit which may serve as a substitute for autologous nerves.

Glomus Tumor in the Second Toe: A Clinical Insight

UNLABELLED Glomus tumors are rare benign tumors commonly occurring in the digits of the hand. Surprisingly, considering the fingertips are of a similar make-up to the toes, there have been few reports of glomus tumor in the toes. The present case highlights a glomus tumor observed in the right second toe of a 56-year-old Indian female who presented with the classical triad of spontaneous pain, cold hypersensitivity, and pressure tenderness. There was a delay in diagnosis for approximately 18 years by various general practitioners who were not aware of the rare presentation of the glomus tumor. The tumor, which measured 5 x 3 mm, was excised from the nail bed of the toe. Histopathological inspection confirmed the diagnosis of glomus tumor. We believe that reporting this rare case may make clinicians more aware of this unusual diagnosis. LEVEL OF CLINICAL EVIDENCE 4.

An elbow dislocation in a child with missed medial epicondyle fracture and late ulnar nerve palsy.

Elbow dislocations associated with a medial epicondyle fracture and ulnar nerve palsy are uncommon injuries. We present the case of an 11-year-old girl with an elbow dislocation treated by closed manual reduction. The medial epicondyle fracture was missed initially until she developed an ulnar nerve palsy 2 months later. Intraoperatively we discovered the bony epicondyle piercing the joint capsule and compressing the ulnar nerve. Removal of the bony fragment relieved her symptoms and she returned to normal activities at 1 year follow-up. We would like to highlight this rare occurrence and present the detailed history and management of this case.

Olfactory ensheathing cells seeded muscle-stuffed vein as nerve conduit for peripheral nerve repair: a nerve conduction study.

We evaluated bridging of 15 mm nerve gap in rat sciatic nerve injury model with muscle-stuffed vein seeded with olfactory ensheathing cells as a substitute for nerve autograft. Neurophysiological recovery, as assessed by electrophysiological analysis was faster in the constructed biological nerve conduit compared to that of autograft.

A CASE OF DISPROPORTIONATE MACRODACTYLY OR A MILD FORM OF PROTEUS SYNDROME? AN INTERESTING CASE

We present a 20-year-old Malay male whom we believe has Proteus syndrome, a rare congenital disorder of asymmetrical overgrowth of body tissues. There are fewer than 100 confirmed cases reported worldwide thus the clinical presentation and histopathological findings are of significance. Our patient presented with an overgrown right small finger and subcutaneous purplish pigmentation over his left upper arm and chest since birth. His small finger gradually increased in size. He had no abnormalities in sensation or power. Radiographs revealed a delta shaped middle phalanx of the small finger. His activities of daily living were uninterrupted but he requested debulking surgery for cosmetic reasons. Histopathological examination reported hypertrophic fatty tissue composed of well formed lobules of mature adipocytes interspersed with fibrous elements.

Human Bone Marrow-Derived MSCs Spontaneously Express Specific Schwann Cell Markers: Spontaneous Schwann Cell Marker Expression

In peripheral nerve injuries, Schwann cells (SC) play pivotal roles in regenerating damaged nerve. However, the use of SC in clinical cell‐based therapy is hampered due to its limited availability. In this study, we aim to evaluate the effectiveness of using an established induction protocol for human bone marrow derived‐MSC (hBM‐MSCs) transdifferentiation into a SC lineage. A relatively homogenous culture of hBM‐MSCs was first established after serial passaging (P3), with profiles conforming to the minimal criteria set by International Society for Cellular Therapy (ISCT). The cultures (n = 3) were then subjected to a series of induction media containing β‐mercaptoethanol, retinoic acid, and growth factors. Quantitative RT‐PCR, flow cytometry, and immunocytochemistry analyses were performed to quantify the expression of specific SC markers, that is, S100, GFAP, MPZ and p75 NGFR, in both undifferentiated and transdifferentiated hBM‐MSCs. Based on these analyses, all markers were expressed in undifferentiated hBM‐MSCs and MPZ expression (mRNA transcripts) was consistently detected before and after transdifferentiation across all samples. There was upregulation at the transcript level of more than twofolds for NGF, MPB, GDNF, p75 NGFR post‐transdifferentiation. This study highlights the existence of spontaneous expression of specific SC markers in cultured hBM‐MSCs, inter‐donor variability and that MSC transdifferentiation is a heterogenous process. These findings strongly oppose the use of a single marker to indicate SC fate. The heterogenous nature of MSC may influence the efficiency of SC transdifferentiation protocols. Therefore, there is an urgent need to re‐define the MSC subpopulations and revise the minimal criteria for MSC identification.

In Vitro Evaluation of Human Hand Tendon Ingrowth into A Synthetic Scaffold

BACKGROUND Synthetic scaffold has been used for tissue approximation and reconstructing damaged and torn ligaments. This study explores the ability of tendon ingrowth into a synthetic scaffold in vitro, evaluate growth characteristics, morphology and deposition of collagen matrix into a synthetic scaffold. METHODS Upper limb tendons were harvested with consent from patients with crush injuries and non-replantable amputations. These tendons (both extensor and flexor) measuring 1 cm are sutured to either side of a 0.5 cm synthetic tendon strip and cultured in growth medium. At 2, 4, 6 and 8 weeks, samples were fixed into paraffin blocks, cut and stained with haematoxylin-eosin (H&E) and Massons trichrome. RESULTS Minimal tendon ingrowth were seen in the first 2 weeks of incubation. However at 4 weeks, the cell ingrowth were seen migrating towards the junction between the tendon and the synthetic scaffold. This ingrowth continued to expand at 6 weeks and up to 8 weeks. At this point, the demarcation between human tendon and synthetic scaffold was indistinct. CONCLUSIONS We conclude that tendon ingrowth composed of collagen matrix were able to proliferate into a synthetic scaffold in vitro.

Usage of synthetic tendons in tendon reconstruction

Damaged tendons or loss of tendon poses a major surgical reconstructive problem. The conventional method is harvest donor tendons from palmaris longus, plantaris or tensor fasciae lata. Synthetic tendons has been used in Achilles tendon repair with studies on equine subjects. We present successful use in three patients with extensive tendon loss secondary to polytrauma. Additionally we have conducted an in-vitro study to analyse the ingrowth of tenocytes into the synthetic tendon. The synthetic tendon utilized in our study is Ortho-tape, a polyethylene terephthalate (polyester) (Neoligaments, Leeds, UK). Its construct is non-absorbable, woven with longitudinal and transverse fibres crossing at right angles. It has an “open structure” acting as a scaffold allowing bone and tissue ingrowth. It is not to be confused with the “permanent type” implant such as Gore-tex which is designed to last a lifetime with no contribution from the host tissue or new tissue growth. Artificial ligaments clinically available has been carbon (Johnson and Johnson), carbon and polyester (Surgicraft), Leeds-Keio polyester (Neoligaments), Dacron (Stryker-Meadox), bovine glutaraldehyde-fixed xenograft (Xenotech) and Gore-Tex polytetrafluoroethylene (WL Gore). Synthetic textile implants do not require donor harvesting shortening surgical procedural time and allows retention of initial strength whilst autografts undergo a necrotic stage before eventually recovering over a long period of time. Additionally, donor tendon grafts have varying properties and dimensions with limited availability. Textile implants has been utilized in ACL reconstruction and patellar ligament reconstruction [1-3] however there has been a decline in usage do to some concerns of synovitis after a prolonged duration 4. Hence some authors recommended usage only in low-activity patients or if donor harvesting was an issue.