The history of viewing bones through telescopes

It is probable that primitive man’s curiosity markedly increased soon after he stood up and started walking on just his feet. He could both peek into caves and drop back onto all fours to peer down badger holes. Looking into his family’s mouths and ears soon followed. Many generations later, his progeny developed metal tubes and glimpsed human interiors through all of our natural orifices. Lighting, however, was always an issue, and the torch that satisfactorily illuminated the cave was poorly accepted by early patients in the proctology clinic.

This changed in 1879 with Edison’s invention of the incandescent light bulb. Just seven years later, two German doctors were lighting up bladders with a tiny bulb on the end of a steel tube through which they squinted. Heat from the bulb and risk of breakage, however, posed problems. Nonetheless, enterprising doctors began poking holes in the skin and exploring the bladder, abdomen, and chest with lighted tubes. In 1912, Severin Nordentoft, a Danish doctor, extended this concept to the knee and coined the word “arthroscopy” (joint-view). Multiple investigators from the world around then refined and continue to refine the technique.

Prior to antibiotics, tuberculosis, especially in the knee, occupied much of orthopedists’ time. This was particularly so in Japan, where squatting and kneeling have long been cultural imperatives. In 1918 Doctor Kenji Takagi began using a bladder scope to examine tuberculous knees. His idea was to develop early treatment that would preclude the awkward outcome of an entirely stiff knee. Over the next 20 years, he designed and tested 12 versions of arthroscopes that were progressively smaller in diameter and that incorporated better optical systems. None of them, however, were entirely practical.

After World War II, Takagi’s student, Masaki Watanabe, took up the banner and continued to make design improvements. In 1957, Watanabe presented a color movie describing his work, first to an international orthopedic meeting in Spain and then to major European and North American orthopedic groups on his way home to Japan. The response was tepid at best.

Undaunted, Watanabe pressed on. The twenty-first version finally provided an adequate view and good focus even though it necessitated grinding each lens by hand. By 1958 this version became the world’s first production arthroscope, but breakage of the incandescent bulb on the end of the tube continued to be problematic. Watanabe began to receive international visitors interested in learning his technique; but when they returned home, began using it, and reported their results, collegial criticism, even ridicule, prevailed.

In 1967 the twenty-second version, for the first time, incorporated a novel fiber optic cable. Now the hot, fragile light bulb could be 6 to 10 feet away from the operative field and transmit “cold light” into the knee joint via thousands of bundled glass threads.

Watanabe developed at least three more versions to further address the conflicting goals of better illumination and visualization vs. smaller diameter scopes that could probe the deepest recesses of small joints. His final version was less than 1/12th of an inch in diameter—about the diameter of a coat hanger wire. Later came miniaturized television cameras that could be attached to the arthroscope. A video monitor in the operating room displayed the images. Now residents, nurses, and students no longer had to stare at the back of the surgeon’s head as he squinted into an eyepiece attached to a narrow tube. Patients, when awake, could watch too, and a video recording of the event later allowed their families untold hours of viewing pleasure. Well, maybe minutes.

Along with further advances in arthroscopic instrument and in scope design, international interest began to grow. At first, every procedure was merely diagnostic and was followed immediately by a large incision and exploration of the joint under direct vision to treat whatever pathology the arthroscope had revealed.

Tiny nippers and shavers, first manual and then also powered, began to allow for arthroscopic treatment as well as diagnosis. Current techniques and instruments even allow the surgeon to place and tie sutures inside a joint. Such minimally invasive surgery allows for faster and more complete rehabilitation. Because the knee joint is large, the innovations started there, but now orthopedists also routinely apply these techniques to the shoulder, elbow, wrist, hip, and ankle joints. Undoubtedly our caveman ancestors, torches and clubs in hand, would be pleased to know where their curiosity for peering into holes has led.