Unicompartmental and bicompartmental arthroplasty of the knee with a finned metal tibial-plateau implant.

We followed a series of ten patients (ten knees) who had a unicompartmental and twenty patients (twenty-two knees) who had a bicompartmental arthroplasty of the knee, in which a finned metal tibial-plateau implant had been used, for two to fourteen years (average, five years) postoperatively. According to the modified criteria of MacIntosh and Hunter, thirty knees (94 per cent) had a good result and two (6 per cent), a fair result. There were two complications: one intraoperative and one postoperative fracture of the tibial plateau. One patient with rheumatoid arthritis required a revision to a total knee arthroplasty at six months because of rapid progression of disease in the contralateral, untreated compartment. Our results suggest that with the proper indications this arthroplasty has a place in reconstructive surgery of the arthritic knee joint.

Bipolar implant shoulder arthroplasty.

A bipolar implant was designed by the author in 1975 for reconstruction of the severely arthritic shoulder. It has the advantage of not requiring glenoidal component fixation, but still provides an artificial joint interface. The ball of the humeral intramedullary stemmed component articulates with a polyethylene bearing within the glenoid cup component. This bipolar prosthesis was implanted in 15 shoulders of patients who presented severe arthritic shoulder disabilities. The follow up period averaged 41 months. Nine patients had rheumatoid arthritis, and five had osteoarthritis; all presented with severe pain and joint crepitation with loss of motion. A "shoulder score" system, based on the rating of pain, activities of daily living and range of motion, was devised to categorize the results obtained. Patients obtained greatly improved range of motion with good to excellent pain relief and very good functional restoration. Radiographically, the implant was well tolerated and there was no stem loosening. This procedure appears to be safe and efficacious for use in the severely arthritic shoulder.

Ligament injuries of the hand and wrist.

Treatment of some complex disorders of the hand and wrist joints continues to challenge even the most experienced clinician. Dr. Maupin discusses both these injuries and the simpler ligament disorders that commonly result from everyday activities.

Long-term silicone implant arthroplasty. Implications of animal and human autopsy findings.

An examination of host tissue response to implanted material has been conducted as part of a comprehensive research program to study low-modulus of elasticity silicone implants for small-joint arthroplasty. This was performed on animals and in a long-term human clinical evaluation. Autopsy material on three dogs was obtained more than ten years after silicone implants were placed in their limbs, and in one human arthritic patient it was obtained 12 years after hand reconstruction with implants. The benign nature of the tissue reaction to the implant material is noted. It is compared with other implant materials and discussed in terms of host tissue reactions that may occur in joint replacement procedures.

Flexible implant arthroplasty in the proximal interphalangeal joint of the hand.

Between 1966 and 1981, 812 proximal interphalangeal joints were reconstructed by the senior author using the flexible silicone rubber implant resection arthroplasty method. Within this series, a group of 182 patients with 424 proximal interphalangeal joint implants were available for a detailed clinical and roentgenographic review. Increased motion in a more functional arc with good pain relief and a favorable bone response pattern were noted in most cases after surgery. Complications were rare and included implant dislocation or fracture, recurrence of deformity, and infection. The highest complication rate was noted in implant reconstructions performed to correct rheumatoid swan-neck deformities.

Flexible implant arthroplasty of the radiocarpal joint. Surgical technique and long-term study.

The wrist joint is frequently impaired in rheumatoid, post-traumatic, and degenerative arthritis. Stable radiocarpal motion, even limited, can improve functional hand adaptations, especially if the proximal or distal joints are disabled. A flexible silicone intramedullary stemmed hinged implant was developed in 1967 to be used as an adjunct to resection arthroplasty of the radiocarpal joint while at the same time maintaining the radiocarpal relation and allowing wrist motion in all planes. The surgical technique includes proper contracture release, bone preparation, extensor tendon repair and balancing, and dorsal and palmar capsuloligamentous repair to allow only 60 degrees of total passive flexion/extension and 10 degrees radial/ulnar deviation. This procedure can be combined with ulnar head capping. Metal bone liners (grommets) may be used to protect the radiocarpal implant from sharp bone edges. From January 1970 to April 1983, 181 wrist implant procedures had been performed in 139 patients, most of whom had rheumatoid arthritis. Stable, pain-free functional motion was obtained in the majority of cases. Roentgenograms showed the implants to be well tolerated by bone. Complications were infrequent. Because this procedure does not require cementing or significant bone resection, revision or arthrodesis procedures are facilitated.

Silicone implants in dogs. A ten-year histopathologic study.

The biocompatibility of implanted materials is important to the successful long-term results obtained in reconstructive surgery with these materials. Recently, interest has emerged regarding host response to the wear debris of implanted material. Since 1962 flexible implant materials have been studied in the Orthopaedic Research Department at Blodgett Memorial Medical Center. An important aspect of this study has been a concern for host tolerance and the evaluation of biologic responses to implanted silicone elastomer. Three dogs in which implants of silicone elastomer had been in place for more than ten years were carefully studied by complete autopsy. A benign foreign-body giant cell response to local silicone wear debris was observed. No silicone particles or macrophage giant cell reactions were found in any distant organs. The host response to silicone wear debris was benign, and no adverse systemic influences were noted.

Scaphoid implant resection arthroplasty. Long-term results.

A silicone scaphoid implant was developed in 1967 to help improve the results of simple resection arthroplasty in the treatment of arthritic changes associated with advanced scaphoid disease. Patients who had scaphoid implant surgery since 1967 were studied. Preoperative and postoperative roentgenograms, charts, surgical pathology, and clinical evaluations were reviewed. A total of 55 cases of scaphoid implant arthroplasty were evaluated. A classification system was developed based on progressive severity, and treatment recommendations were developed for each stage of disease progression. Cystic and degenerative changes in contiguous carpal bones were evaluated. No evidence of cystic change could be found in 37 wrists, minimal changes were found in 9, moderate changes in 5, and severe changes in 4. There were no implant infections or fractures. Implant rotation occurred in two cases. Functional use of the hand with decreased pain was observed. It is important to detect and treat carpal instability, which may be associated with scaphoid disease. Cystic formation can be minimized by avoiding oversized implants, treating the associated carpal instability, bone-grafting preexisting cysts, and avoiding Kirschner wire fixation. By following treatment protocols as established in the classification system, the scaphoid implant can be successfully used in the management of scaphoid pathology.

The use of a grommet bone liner for flexible hinge implant arthroplasty of the great toe.

Press-fit titanium grommets were developed to shield flexible hinged silicone implants used for arthroplasty of the radiocarpal, metacarpophalangeal, and metatarsophalangeal joints. Since 1985, 179 titanium circumferential grommets were used in 90 first metatarsophalangeal joints with excellent, pain-free, functional results and favorable bone response around the implant stems and at the bone-grommet interface. There were no complications due to particulate reactivity, implant fracture, or grommet fracture. The use of circumferential titanium grommets appears to be a safe and effective method to improve the long-term durability of flexible hinge implant arthroplasty of the first metatarsophalangeal joint.