Unacceptable failure of the PI2® implant

Thumb Carpometacarpal Implant Arthroplasty

Thumb carpometacarpal implant arthroplasty aims to preserve thumb length and motion and to provide pain relief and functional recovery after a short postoperative time. For several decades, implant arthroplasty has been performed with total trapeziometacarpal joint prosthesis using the concept of "ball-and-socket" joint. More recently, pyrocarbon implants used as hemiarthroplasty or interposition arthroplasty have been proposed. Whatever the type of arthroplasty used, the surgical technique must be precise and may require a learning curve. Implant arthroplasty has proven that in the medium and long-term, it may be considered as a valid and reliable alternative to trapeziectomy.

Pyrocarbon Arthroplasty Implants in the Upper Extremity: A Systematic Review of Outcomes and Pooled Analysis of Complications

BACKGROUND

Growing use of pyrocarbon implants in upper extremity arthroplasty has culminated in a breadth of literature ascertaining outcomes and complications at long-term follow-up. However, at present, the literature remains devoid of studies synthesizing the available evidence for upper extremity surgeons to adequately assess the safety and utility of these implants relative to other available options.

METHODS

A systematic search of the National Library of Medicine, MEDLINE, and Embase databases was performed to determine clinical outcomes and complication and reoperation rates following pyrocarbon arthroplasties in the upper extremity. A breakdown of complication and reoperation rates for each independent joint (shoulder, elbow, wrist, and hand joints), and according to specific causes necessitating surgery, was also compiled.

RESULTS

A comprehensive summary of functional outcomes following upper extremity pyrocarbon arthroplasties is presented. Overall complication and reoperation rates in the hand and wrist were determined to be 28.2 percent and 17 percent, respectively. The proximal interphalangeal joint was associated with the highest complication rate (42.7 percent), followed by carpometacarpal joint (18.8 percent), metacarpophalangeal joint (17.6 percent), wrist (16 percent), elbow (15.7 percent), and shoulder (12.9 percent). In the hand and wrist, major complications included dislocations and subluxations (8.4 percent), stiffness and limited motion (4.4 percent), deformity (3.1 percent), hardware failure (1.9 percent), fractures (1.7 percent), persistent pain (1.7 percent), and infections (0.9 percent).

CONCLUSION

In the absence of large clinical trials, systematic reviews such as these can help inform clinical guidelines and provide practitioners with an evidence-based reference to improve informed consent.

Joint replacement for trapeziometacarpal osteoarthritis: implants and outcomes

For thumb carpometacarpal osteoarthritis, trapeziectomy provides generally good results with reduction of pain and restoration of thumb mobility, but shortening of the thumb may at least in theory lead to reduction in grip and pinch strength. Furthermore, instability of the base of the first metacarpal and contact with the scaphoid may occur regardless of the several described techniques with ligament reconstruction and tendon interposition. Thus, for years alternatives to trapeziectomy have been explored and reported with disputable success. Often the road from idea to implantation in patients seems to have been short, and high complication rates and failure of new implant designs have been fairly common. This has led to the general impression that the implants do not provide sufficient benefits compared with simple trapeziectomy. More recent uncemented total joint replacement designs have shown rapid rehabilitation, reduction of pain, restoration of grip strength and movement, and much improved long-term implant survival. These factors may make total joint replacement a realistic alternative to trapeziectomy. Still, patient selection has to be improved, as the benefits may be small in the low activity elderly patient.

Pyrocarbon implants for the basal thumb arthritis

Silicone implants for the treatment of basal thumb arthritis were first proposed in the 1970's by Swanson. They became extremely popular and despite good functional results, the high rate of complications such as instability, material breakage and foreign body reactions led to them being progressively abandoned by most surgeons. Pyrocarbon implants were introduced at the beginning of the 2000's. A large range of different implant models that can be used for either hemiarthroplasty or interposition arthroplasty. For some implants, a supplemental ligamentoplasty procedure is required to avoid instability. Miniaturization of some implants provides new options for minimally invasive surgery, which is relevant in low and medium grades of osteoarthritis, especially for young, active patients. Medium- and long-term follow-up have now been reached by some pyrocarbon interpositions. Their results confirm that these implants are a reliable alternative to other techniques. This paper focuses on the surgical techniques and outcomes of pyrocarbon implants for the treatment of basal thumb arthritis. It is based on published data and the author's experience.

Pyrocardan Trapeziometacarpal Joint Arthroplasty-Medium-Term Outcomes

Objective  Pyrocardan trapeziometacarpal interposition implant is a free intra-articular spacer composed of pyrocarbon. This biconcave resurfacing implant, both ligament and bone-stock sparing, is indicated for use in early-to-moderate stage trapeziometacarpal osteoarthritis. It was hypothesized that the postoperative outcome measures of the Pyrocardan implant would be comparable to those seen with ligament reconstruction and tendon interposition (LRTI) surgeries and those reported by the designer of the implant, Phillipe Bellemère, but that strength would be greater than for LRTI. Methods  In this prospective case series, 40 Pyrocardan implants were performed in 37 patients. Average age was 58 years (range: 46-71). Patients were assessed preoperatively, 3 months, 6 months, 1 year, 2 years, and beyond (long term) wherever possible. Results  There have been no major complications or revision surgeries for the series. Average follow-up was 29 months (range: 12 months-7 years). Twenty-eight joints were assessed at over 2 years post index surgery. Outcome measure scores improved from preoperative assessment to the most recent follow-up equal or greater than 2 years. Average grip strength at 2 years was 30 kg, as compared with 19.6 kg in an age-matched cohort who underwent trapeziectomy and 25 kg in Bellemère's original series of Pyrocardan implants. Conclusions  Pyrocardan interposition arthroplasty appears to be a safe, effective treatment for trapeziometacarpal arthritis. Patient-reported clinical outcomes were at least equivalent to LRTI and are comparable to Bellemère's original series. Grip and pinch strength appear to be better than LRTI. Level of Evidence  This is a Level III, prospective observational cohort study.

Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal osteoarthritis: minimum 8-year follow-up

We undertook a retrospective study to evaluate minimal 8-year outcomes of 46 trapeziometacarpal joints (46 patients) treated with pyrocarbon implant arthroplasty after partial trapeziectomy for trapeziometacarpal joint osteoarthritis in two different hand surgery units. The mean follow-up interval was 9.5 years (average 113 months with a range 97-144 months). The study showed that pyrocarbon interpositional arthroplasty provided pain relief and high patient satisfaction. All patients experienced a reduction in the DASH score, with an average change of 30 points. The visual analogue scale score, the Kapandji score, and key pinch also showed remarkable improvement. The PyroDisk implant exhibited good longevity, with good implant survival. A review of the literature revealed that the functional outcomes after implant surgery are not superior to more common techniques, such as trapeziectomy with or without ligamentoplasty. Therefore, this is a reliable surgery but may not have added benefits over simpler surgical treatments. This implant could have a role, perhaps in a select group of young patients, as a time-procuring procedure. Level of evidence: IV.

Failure Rates of Base of Thumb Arthritis Surgery: A Systematic Review

PURPOSE

The purpose of the current review was to estimate failure rates of trapeziometacarpal (TMC) implants and compare against failure rates of nonimplant techniques for surgical treatment of TMC joint (basal thumb joint) arthritis.

METHODS

A systematic review was conducted to identify articles reporting on thumb implant arthroplasty and on nonimplant arthroplasty techniques for treatment of base of thumb arthritis in the English literature. The collected data were combined to calculate failure rates per 100 procedure-years. Failure was defined by the requirement for a secondary salvage procedure. The failure rates between different implant and nonimplant arthroplasty groups were compared directly and implants with higher than anticipated failure rates were identified.

RESULTS

One hundred twenty-five articles on implant arthroplasty and 33 articles on the outcome of nonimplant surgical arthroplasty of the TMC joint were included. The implant arthroplasty failure rates per 100 procedure-years were total joint replacement (2.4), hemiarthroplasty (2.5), interposition with partial trapezial resection (4.5), interposition with complete trapezial resection (1.7), and interposition with no trapezial resection (4.5). The nonimplant arthroplasty failure rates per 100 procedure-years were: trapeziectomy (0.49), joint fusion (0.52), and trapeziectomy with ligament reconstruction ± tendon interposition (0.23).

CONCLUSIONS

Several implant designs (arthroplasties) had high rates of failure due to aseptic loosening, dislocation, and persisting pain. Furthermore, some implants had higher than anticipated failure rates than other implants within each class. Overall, the failure rates of nonimplant techniques were lower than those of implant arthroplasty.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.