Humeral cup fixation in rheumatoid shoulders. Roentgen stereophotogrammetry of 12 cases

Cementless Metal-Free Ceramic-Coated Shoulder Resurfacing

Shoulder resurfacing is a versatile, bone-conserving procedure to treat arthritis, avascular necrosis, and rotator cuff arthropathy. Shoulder resurfacing is of interest to young patients who are concerned about implant survivorship and those in need of a high level of physical activity. Using a ceramic surface reduces wear and metal sensitivity to clinically unimportant levels. Between 1989 and 2018, 586 patients received cementless, ceramic-coated shoulder resurfacing implants for arthritis, avascular necrosis, or rotator cuff arthropathy. They were followed for a mean of 11 years and were assessed using the Simple Shoulder Test (SST) and Patient Acceptable Symptom State (PASS). CT scans were used in 51 hemiarthroplasty patients to assess the glenoid cartilage wear. Seventy-five patients had a stemmed or stemless implant in the contralateral extremity. A total of 94% of patients had excellent or good clinical results and 92% achieved PASS. 6% of patients required a revision. A total of 86% of patients preferred their shoulder resurfacing prosthesis over a stemmed or stemless shoulder replacement. The glenoid cartilage wear at a mean of 10 years was 0.6 mm by a CT scan. There were no instances of implant sensitivity. Only one implant was removed due to a deep infection. Shoulder resurfacing is an exacting procedure. It is clinically successful, with excellent long-term survivorship in young and active patients. The ceramic surface has no metal sensitivity, very low wear, and, therefore, it is successful as a hemiarthroplasty.

The accuracy and precision of radiostereometric analysis in upper limb arthroplasty

Background and purpose - Radiostereometric analysis (RSA) is an accurate method for measurement of early migration of implants. Since a relation has been shown between early migration and future loosening of total knee and hip prostheses, RSA plays an important role in the development and evaluation of prostheses. However, there have been few RSA studies of the upper limb, and the value of RSA of the upper limb is not yet clear. We therefore performed a systematic review to investigate the accuracy and precision of RSA of the upper limb. Patients and methods - PRISMA guidelines were followed and the protocol for this review was published online at PROSPERO under registration number CRD42016042014. A systematic search of the literature was performed in the databases Embase, Medline, Cochrane, Web of Science, Scopus, Cinahl, and Google Scholar on April 25, 2015 based on the keywords radiostereometric analysis, shoulder prosthesis, elbow prosthesis, wrist prosthesis, trapeziometacarpal joint prosthesis, humerus, ulna, radius, carpus. Articles concerning RSA for the analysis of early migration of prostheses of the upper limb were included. Quality assessment was performed using the MINORS score, Downs and Black checklist, and the ISO RSA Results - 23 studies were included. Precision values were in the 0.06-0.88 mm and 0.05-10.7° range for the shoulder, the 0.05-0.34 mm and 0.16-0.76° range for the elbow, and the 0.16-1.83 mm and 11-124° range for the TMC joint. Accuracy data from marker- and model-based RSA were not reported in the studies included. Interpretation - RSA is a highly precise method for measurement of early migration of orthopedic implants in the upper limb. However, the precision of rotation measurement is poor in some components. Challenges with RSA in the upper limb include the symmetrical shape of prostheses and the limited size of surrounding bone, leading to over-projection of the markers by the prosthesis. We recommend higher adherence to RSA guidelines and encourage investigators to publish long-term follow-up RSA studies.

Long-term results and patient satisfaction after shoulder resurfacing

BACKGROUND

Shoulder resurfacing has regained popularity in recent years. This report presents the long-term (>20 years) results of this procedure with regard to patient satisfaction and implant survival.

MATERIALS AND METHODS

We followed up 61 patients who underwent shoulder resurfacing procedures (74 shoulders) for a minimum of 20 years or until death (7 additional patients were lost to follow-up). The mean patient age at the time of surgery was 58 years. There were 41 total resurfacing procedures and 33 hemi-resurfacing procedures. The humeral component consisted of a cup with a short central peg that was placed either with or without cement. The glenoid was resurfaced with a cemented polyethylene or polyurethane component.

RESULTS

Patient satisfaction was 95%, and the survivorship of the humeral prostheses was 96%. There were no periprosthetic fractures, dislocations, or infections. Two humeral components were revised to stemmed prostheses (one for loosening and one for unexplained pain), and one was revised from a cementless to a cemented resurfacing prosthesis. Twelve cemented polyethylene glenoid prostheses had radiolucencies, but only three produced symptoms requiring revision surgery; three polyurethane glenoid prostheses showed severe wear radiographically, but none was loose or required revision surgery. There were 7 revision procedures, 6 with good results.

CONCLUSIONS

Shoulder resurfacing is a successful procedure for the majority of patients, with high rates of patient satisfaction, long-term survivorship of the humeral prosthesis, and few complications.