“Needlescope” Small Diameter Arthroscope (Dyonics)

Accession Number: 2020.JAC.11

Alternative Name:

Primary Materials: Stainless Steel, Glass

Printed on the body of the instrument, near the eyepiece: “DYONICS// Needlescope®// MADE IN U.S.A”
Printed along the bottom edge of the eyepiece: “1544”

Dimensions (cm): Height = 5, Width = 3, Length = 29.2

An arthroscope is an optical instrument for viewing the interior of a joint during a surgical operation. Its development made possible minimally invasive surgery for many knee operations.

The Needlescope is a specialized narrow gauge arthroscope that uses a Japanese-made GRIN (Graded Refractory INdex) lens. It was developed for use in narrow joints and in diagnosis in the early 1970s.

There are light abrasions along the body of the instrument. There are also patches of deposit, or possible light oxidation, on the same surface. The printed markings are lightly damaged but still readable.

Associated Instruments:

Manufacturer: Dyonics corp., Andover, Mass, USA.

Date of Manufacture: c. 1970s

The Robert W. Jackson Arthroscopy Collection was acquired by the University of Toronto from Dr. Jackson’s family on November 12th, 2020.

Masaki Watanabe, ed. (1985). Arthroscopy of Small Joints. 1st ed. Igaku-Shoin.

Lanny L. Johnson (1986). Arthroscopic Surgery : Principles & Practice. 3rd. ed. Mosby.

Ken Johnson (1995) “Smith & Nephew merges Dyonics and Acufex to form new instrument company.” Lawrence Eagle-Tribune, North Andover, Mass.

The technology behind the Needlescope is the Selfoc beam transmitting glass lens. This was developed jointly by the Nippon Sheet Glass Company of Osaka and the Nippon Electric Company in Tokyo. Selfoc is a brand name derived from “self-focusing”. It became available in 1968 and was designed as a material for transmitting laser beams (Watanabe 1985, 5). A glass Selfoc rod is a GRIN (Graded Refractory INdex) lens that is able to transmit light along its length due to a refractory index that decreases from centre to periphery (Johnson 1986, 180).

Selfoc technology was adopted by the orthopaedic researchers at Tokyo Teishin Hospital working under Dr. Masaki Watanabe (1911-1995). This group had pioneered the Watanabe Type No. 21 arthroscope, first developed in 1959, which made possible the widespread adoption of arthroscopy within orthopaedics. (There are several examples in this collection.) Following this success, the group turned their attention to the development of a narrow gauge arthroscope that could be used in small joints.

The Selfoc lens proved well suited to this application. It provided a much clearer image than a fibre optic bundle, while being less fragile. It also (as its name implies) was self focusing and therefore usable at greater focal lengths than conventional lenses. The Watanabe group used the technology as the basis for the Type No. 24 arthroscope set, which first became available in January of 1970 before going through a series of revisions.

The original Type No. 24 arthroscope consisted of a 1mm Selfoc rod surrounded by a .25mm thick layer of optical fibres for transmitting light. The tip had a total diameter of 1.7mm with its stainless steel casing. The group worked with the Olympus Optical Company to improve the system and develop two production models, a 1.7 mm and a 2.2 mm diameter example, which differed in the thickness of the layer of light-transmitting optical fibres and hence the brightness of the image. (See Watanabe 1985, 7-11 for details.) Years of work with this instrument resulted in the publication of Arthroscopy of Small Joints in 1985, which featured many photos taken through its lens.

Development of the Needlescope

The emergence of the Dyonics Needlescope and its relationship to the earlier Watanabe Type No. 24 is not entirely clear. The Needlescope was introduced in 1973, and used the same Japanese-made Selfoc lenses in the same outside diameters. Writing in the third edition of his arthroscopy textbook in 1986, Dr. Lanny L. Johnson, a promoter of the Needlescope, described the No. 24 as “… the precursor of the Dyonics Needlescope…” (Johnson 1986, 180).

The Needlescope enjoyed a period of popularity between its introduction in 1973 and Johnson’s 1986 textbook. This had more to do with its value as a less-invasive diagnostic instrument for conventional knee arthroscopy than its utility in small joint arthroscopy. However, the widespread adoption of CCD cameras in arthroscopy required brighter images than the Needlescope could produce and its use became limited to small joint work.

In 1986, Dyonics was acquired by Smith+Nephew, based in London, UK.

In 1995, Smith+Nephew merged Dyonics with had recently acquired Acufex to form Smith & Nephew Endoscopy, based in Andover.