Complications of prosthesis versus trapeziectomy in trapeziometacarpal joint arthritis: A systematic review.

OBJECTIVE: Thumb osteoarthritis is a frequent pathology, mainly affecting the elderly. The surgical treatment initially described and having proved its worth is total trapeziectomy. Since the advent of trapeziometacarpal prostheses, several studies showed the non-inferiority of this technique on clinical criteria, with superiority in bone sparing, although neither technique demonstrated overall superiority. We therefore examined the specific complications of each surgical technique by analyzing their nature and prevalence through a review of the literature to compare them on these new parameters. METHODS: Seventy-four of the 320 articles reviewed were included, 38 of which concerned trapeziectomy, and 36 concerned prostheses, for a total of 4,865 patients. They were original studies, involving adults undergoing trapeziometacarpal arthroplasty or trapeziectomy, published after 2015, reporting at least one well-described complication. RESULTS: 6.13% of trapeziectomies presented severe complications (in particular thumb collapse and metacarpophalangeal hyperextension), 3.31% moderate complications and 1.90% minor complications, leading to a 2.0% revision rate. 23.88% of prostheses had severe complications (loosening, dislocation and wear), 5.06% moderate complications and 1.36% minor complications, leading to a 12.8% revision rate. In addition, we analyzed more recent prosthesis designs separately, and found lower prevalence of severe complications (16.56%) and revision surgery (4.3%). CONCLUSION: Revision surgery for trapeziometacarpal prostheses is usually only a standard trapeziectomy with the same follow-up as first-line trapeziectomy, whereas revision surgery for trapeziectomies is much more complex and the results are uncertain. For this reason, we would reserve total trapeziectomy for revision surgeries and patients with low functional demand for whom a second surgery is not desirable. Further studies could confirm this attitude, especially focusing on the latest generation of dual mobility implants.

Study of mechanical effects of lumbar disc arthroplasty on facet joints at the index level/adjacent levels by using a validated finite element analysis.

Introduction: Lumbar disc arthroplasty is a surgical procedure designed to treat degenerative disc disease by replacing the affected disc with a mobile prosthesis. Several types of implants fall under the term total disc replacement, such as ball-and-socket, mobile core or elastic prostheses. Some studies have shown that facet arthritis can develop after arthroplasty, without much precision on the mechanical impact of the different implant technologies on the facet joints. This study aims to create validated patient-specific finite element models of the intact and post-arthroplasty lumbar spine in order to compare the mechanical response of ball-and-socket and elastic prostheses. Methods: Intact models were developed from CT-scans of human lumbar spine specimens (L4-S1), and arthroplasty models were obtained by replacing the L4-L5 disc with total disc replacement implants. Pure moments were applied to reproduce physiological loadings of flexion/extension, lateral bending and axial rotation. Results: Models with ball-and-socket prosthesis showed increased values in both range of motion and pressure at the index level and lower values at the adjacent level. The mechanical behaviour of the elastic prosthesis and intact models were comparable. The dissipated friction energy in the facet joints followed a similar trend. Conclusion: Although both implants responded to the total disc replacement designation, the mechanical effects in terms of range of motion and facet joint loads varied significantly not only between prostheses but also between specimens. This confirms the interest that patient-specific surgical planning using finite element analysis could have in helping surgeons to choose the appropriate implant for each patient.