ArtiFacts: Austin Moore’s Hip

In 1939, J. Austin Talley Moore (1899-1963), an orthopaedic surgeon at the Moore Orthopaedic Clinic at Colombia University in New York City, replaced the proximal end of the femur with a metal appliance that matched the form of the hip. Upon recovery, the patient had regained 75% normal hip function and was able to walk with a cane. When the patient died two years later from an acute cardiac arrest, the prosthesis was extracted and found to be in excellent condition [3].

Moore resumed designing his artificial hip in 1950. The original design (Fig. 1) was modified to move the femoral neck into a more anatomically accurate position. In the first five years of performing his procedure, he reported success with his first 153 patients, most of whom were 60 to 70 years old. Of the 55 patients Moore followed up with after two years, 45 had good to excellent outcomes, defined as being able to walk unaided or assisted with a crutch or a cane and having a slight or moderate limp with a 100% range of motion. The rehabilitation process described by Moore indicated partial weightbearing for the first six months. He recommended that patients use a cane, minimize weight gain, and “avoid excessive stress in the same way that one who uses a dental prosthesis avoids excessive chewing of hard or tough food” [3].

Fig. 1.

This is an Austin Moore hip hemiarthroplasty prosthesis manufactured by Howmedica Inc. in the 1970s. It was evaluated by Dr. John Insall and Dr. Albert Burstein at the Hospital for Special Surgery in New York City, but never implanted. [M- 129.11109] (Disclosure: This image has been cropped to emphasize the subject.) (National Museum of Health and Medicine photo by Ian Herbst.)

What is astonishing is how biologically unremarkable the Austin Moore prosthesis turned out to be. At a time when surgeons were uncertain about whether the human body could tolerate the implantation of a large metal prosthesis, it was not rejected, it generally didn’t loosen, and fractures related to implantation were uncommon. On the contrary, compression resulting from weightbearing of the prosthesis caused thickening of the bone around the implant [3], providing a practical application of Wolff’s law (that bone will remodel itself according to the load placed upon it [5]). Austin Moore’s rehabilitation protocol, which involved partial weightbearing with a crutch, provided the necessary compression through weightbearing to facilitate healing.

Perhaps more importantly, Moore created a prosthesis that was robust enough to sustain the patient during routine activities of daily life almost a half century before the forces sustained by the human hip were understood or quantified. One study [4] from 1975 of 451 patients, most of whom were women older than 50, found that the primary mechanical complication from the procedure was dislocation of the hip, which occurred in only 2.2% of patients. None experienced loosening, periprosthetic fractures, or implant breakage.

The Austin Moore artificial hip is still being manufactured and used in many parts of the world, where it is considered a good choice in resource-constrained environments, particularly for older, less-active patients with femoral neck fractures. The Austin Moore hip remains widely available in India since it is less expensive and can be implanted more quickly than many contemporary alternatives, while still delivering adequate results. According to one follow-up study published from India in 2019 [2], more than three-quarters of the 95 patients studied had either good or excellent results four to eight years after surgery with this device, based on their Harris Hip Scores. The study did note one shortcoming, which the author “considered as an essential requirement as per the Indian scenario”—most patients had difficulty squatting. Moore was unlikely to have considered that in the design of his prosthesis.