Pyrocarbon Implants Research Articles

Intraoperative Periprosthetic Fractures in Proximal Interphalangeal Joint Arthroplasty

To examine the frequency, risk factors, and postoperative outcomes associated with intraoperative periprosthetic fractures during proximal interphalangeal (PIP) joint arthroplasty. We examined 382 consecutive PIP joint arthroplasties in 205 patients. Procedures were performed from 1998 to 2012. The patients were identified and outcomes were collected through a single institution's total joints registry, collecting additional information not contained in the prospectively collected registry through medical record examination. Multiple outcomes were analyzed relating to the fractures, the hard surgical outcomes, finger function, and radiographic findings. Statistical analysis was performed utilizing Kaplan-Meier survival models, log-rank tests, univariate analysis, Student t test and Fisher exact test. Intraoperative periprosthetic fracture occurred in 5% (n= 20) of 383 PIP joint arthroplasties. All of the patients who had an intraoperative fracture were women. Lower body mass index and a diagnosis of rheumatoid arthritis were associated with a significantly higher risk of intraoperative fracture. The use of pyrocarbon implants also significantly increased fracture risk. At a median follow-up of 5.3 years, there were no refractures in the patients who sustained an intraoperative fracture. Six patients underwent revision surgery, with a 2- and 5-year survival rate free of revision surgery of 76% and 64%, respectively. These rates were not significantly different from those without intraoperative fractures. There was no significant difference in the incidence ofpostoperative complications between patients with or without an intraoperative fracture. Intraoperative fractures occur in about 5% of PIP joint arthroplasties. These periprosthetic fractures do not appear to influence outcomes, including revision surgery, refracture rate, or other early complications. Female sex, lower body mass index, rheumatoid arthritis, and the use of pyrocarbon implants were associated with increased risk for intraoperative fractures. This information may help decrease fracture risk and help surgeons identify andtreat the fractures when they do occur. Prognostic II.

Revision Proximal Interphalangeal Arthroplasty: An Outcome Analysis of 75 Consecutive Cases

To examine the outcomes and complications associated with revision proximal interphalangeal (PIP) joint arthroplasty. An analysis of 75 consecutive revision PIP joint arthroplasties in 49 patients, performed between 1998 to 2012, was performed. The mean age at the time of surgery was 58 years. Thirty-two patients had a history of prior PIP joint trauma, and 18 patients had rheumatoid arthritis. There were 12 constrained (silicone) implants and 63 nonconstrained implants (34 pyrocarbon and 29 metal-plastic). Over the 14-year period, 19 (25%) fingers underwent a second revision surgery. Second revision surgeries were performed for infection, instability, flexion contracture, and heterotopic ossification. The 2-, 5-, and 10-year survival rates were 80%, 70%, and 70%, respectively, for patients requiring a second revision for PIP joint arthroplasty. Worse outcomes were seen with postoperative dislocations, pyrocarbon implants, and when bone grafting was required. Two operations were complicated by intraoperative fractures, but neither required stabilization. Sixteen patients undergoing revision surgery experienced a postoperative complication, including 2 infections, 1 postoperative fracture, 3 cases of heterotopic ossification, and 10 PIP joint dislocations. The volar approach and the use of a pyrocarbon implant was associated with increased rates of heterotopic ossification, whereas preoperative instability increased the rates of PIP joint dislocation following revision. At a mean of 5.3 years (range, 2-10 years) follow-up, 98% of patients had good pain relief but decreased PIP joint total arc of motion. Proximal interphalangeal joint arthroplasty in the revision setting represents a challenge for surgeons. Revision arthroplasty was associated with a 70% 5-year survival but with a high incidence of complications. Instability was associated with worse outcomes. In this series, silicone and metal-polyethylene implants had lower rates of implant failure and postoperative complications than ones made from pyrocarbon.

Intraoperative Periprosthetic Fractures Associated With Metacarpophalangeal Joint Arthroplasty

To assess the incidence of and identify risk factors for intraoperative periprosthetic fractures during primary and revision metacarpophalangeal (MCP) joint arthroplasty. Through our institutional Joint Registry Database, we identified 818 MCP joint arthroplasties performed in 285 patients from 1998 to 2012, including 690 primary arthroplasties and 128 revision arthroplasties. Primary diagnoses included inflammatory arthritis (667), osteoarthritis (75), and posttraumatic arthritis (76). Periprosthetic fractures were identified through review of medical records. Intraoperative periprosthetic fractures occurred in 23 (3%) fingers (21 patients), including 19 primary and 4 revision arthroplasties. Twelve fractures required stabilization, 4 required only bone grafting, and 1 required both. The fractures occurred during broaching (12), implantation (10), or prior implant removal (1). Diabetes mellitus (DM), younger age, pyrocarbon implant insertion, and cementless fixation increased risk for intraoperative fracture. In particular, DM and the use of pyrocarbon implants significantly increased fracture risk. At 4 years (range, 1.3-10.2 y) average follow-up, no patient with intraoperative fracture had developed a subsequent fracture compared with 3 postoperative fractures in patients without intraoperative fractures. All fractures had healed by the time of the last follow-up. The 2- and 5-year implant survival rates were 96% and 80% in those with intraoperative fractures, respectively, which was not significantly different from those without an intraoperative fracture. When comparing patients with an intraoperative fracture with those without, there was an increased risk of postoperative MCP joint instability defined as implant dislocation. Patients with intraoperative fractures still had noteworthy improvements in their postoperative pain levels and pinch strengths. Intraoperative fractures occurred in 3% of MCP joint arthroplasties, including 3% of primary and 3% of revision arthroplasties. Increased risk for fracture was associated with the use of pyrocarbon implants, cementless fixation, and DM. Although these fractures did not appear to adversely affect implant survival, they were associated with increased risk of postoperative instability. Prognostic III.

Ten year follow-up of pyrocarbon implants for proximal interphalangeal joint replacement

Results of anatomical resurfacing of the proximal interphalangeal joint using pyrocarbon implants showed reasonable clinical results with a high radiographic migration rate. The aim was to investigate the subjective, clinical, and radiographic results 10 years following surgery, and to compare them with our 2-year follow-up data. We re-evaluated 12 patients with 15 proximal interphalangeal implants on average 9.7 years after surgery. Pain significantly improved from 7.6 on a visual analogue scale pre-operatively to 1.4 at 2 years, and to 0.7 at the final follow-up. The mean total range of motion in all replaced joints was 36° pre-operatively and 39° at the 2-year follow-up, but had decreased significantly to 29° at 10 years. We saw one implant migration in addition to the eight migrated implants we already found 2 years after surgery. The moderate clinical results, combined with the high migration rate, mean that we no longer use this kind of implant.

An Alternative Treatment Option for Scaphoid Nonunion Advanced Collapse (SNAC) and Radioscaphoid Osteoarthritis: Early Results of a Prospective Study on the Pyrocarbon Adaptive Proximal Scaphoid Implant (APSI)

Scaphoid nonunion advanced collapse (SNAC) and radioscaphoid osteoarthritis are difficult to treat. Options include proximal row carpectomy (PRC), four corner fusion (4CF) and wrist arthroplasty or arthrodesis. However, with inevitable disease progression, a significant proportion of patients undergo total wrist fusion. This reduces function by abolishing wrist movement. We review the preliminary results of a pyrocarbon interpositional radiocarpal implant in a small cohort of patients from our prospective study and challenge the assumption that there are no surgical alternatives. This study prospectively studied 12 consecutive pyrocarbon Interpositional arthroplasty day cases over 3 years. Patients were assessed using level of pain, ranges of motion, grip strength, key pinch, type of and time to return to work and the disabilities of the arm, shoulder and hand (DASH) score, both preoperatively and postoperatively. Radiographs were also taken and patient satisfaction recorded. All 12 patients could be contacted and were satisfied with their surgery. There were no immediate, early or late postoperative complications associated with the procedure. Promising results were noted in terms of pain, ranges of motion, grip strength, key pinch, type of and time to return to work, DASH scores, photographs and radiographs. The mean follow-up was 18 months, range between 11 months and 3 years. Our early results are encouraging, warrant further and longer studies and support the use of pyrocarbon implants as a primary procedure in what is a generally young and active subgroup of patients.

Pyrocarbon versus Silicone Proximal Interphalangeal Joint Arthroplasty

Arthritis at the proximal interphalangeal joint can be a disabling chronic condition. Silicone arthroplasty is a common surgical treatment option to provide pain relief and maintain joint mobility. Pyrocarbon implants are gaining popularity as an alternative to silicone prostheses. The purpose of this systematic review is to compare the outcomes of silicone and pyrocarbon arthroplasties for patients with proximal interphalangeal joint arthritis. A computerized search was conducted to identify studies evaluating outcomes of silicone and pyrocarbon arthroplasties. The data extracted were patient demographics, pain relief, range of motion, grip and pinch strength, costs, quality of life, and complications. Thirty-five relevant citations were identified. Available data showed that both arthroplasties offered satisfactory pain relief. The implants also provided similar postoperative weighted mean arcs of motion, with a value of 37.4 ± 13.6 degrees for silicone and 44.8 ± 16.8 degrees for pyrocarbon. There were comparable results in grip and pinch strengths as well. No studies were identified that performed an economic analysis of arthroplasty. Six studies assessed quality-of-life outcomes after pyrocarbon surgery, and results were mixed. The rates of revision and salvage procedures performed secondary to complications were higher after pyrocarbon arthroplasty. Based on the available low level of evidence, pyrocarbon arthroplasty does not demonstrate clear superiority over silicone implants. In fact, there is concern about the complication rates of these implants. Future studies should focus on more rigorous study designs using validated quality-of-life scales and economic evaluations before widespread adoption of this new implant. Therapeutic, IV.

Proximal interphalangeal joint replacement with an unconstrained pyrocarbon prosthesis (Ascension®): a long-term follow-up

There have been limited publications that report long-term outcomes of pyrocarbon implants. This report describes both clinical and radiographic long-term results for patients who have been treated with pyrocarbon proximal interphalangeal implants. Thirteen implants in ten patients are reported for an average follow-up of 8.3 years (range 6.2-9.3). All patients were suffering from degenerative joint disease. Five of the 13 digits were free of pain, the remaining eight digits had mild to moderate pain (visual analogue scale 2-5). The average active range of motion was 58° (SD 19°) at latest examination. X-ray results were unremarkable in six digits with an acceptable position of the prosthesis. However, in seven patients significant radiolucent lines (≥ 1 mm) were observed. Three prostheses demonstrated a migration of the proximal component, and one a subsidence of the distal component. Our study does not support the use of this implant for treatment of osteoarthritis of the finger joint owing to high complication rates and limited range of motion.

A Prospective, Randomized Comparison of 3 Types of Proximal Interphalangeal Joint Arthroplasty

For surface replacement arthroplasty in proximal interphalangeal joint osteoarthritis, titanium-polyethylene (TI) and pyrocarbon (PY) implants are frequently used. However, their superiority in comparison to the silicone (SI) spacer has not been established. The purpose of this study was to compare these 3 types of implants with regard to outcome. A prospective, randomized, multicenter trial was performed. A total of 43 patients (62 proximal interphalangeal joints) had surgery in the 3 participating centers, and each patient was randomly allocated to one of the 3 groups (TI, PY, SI). Range of motion (ROM) and strength were measured before surgery; pain and disability self-assessment and radiographic analysis were also completed. The same examination protocol was planned for 3 months, 6 months, and 1, 2, and 3 years after surgery, but some follow-up visits did not take place due to patient death or poor compliance. The mean follow-up time at the final follow-up was 35 ± 3 months (range, 30-41 mo). All implant types led to significant pain reduction at rest and at load. Tip pinch strength was slightly improved by all 3 devices at the 3-year follow-up. No significant improvement in ROM for silicone or resurfacing implants was found. However, when comparing the highest ROM values reached after surgery, the resurfacing devices tended to show superior joint motility compared to silicone spacers, albeit only temporarily and not significantly. Sixteen explantations were necessary: 2 of 18 SI (11%), 7 of 26 TI (27%) and 7 of 18 PY (39%) implants had to be removed. An additional 4 secondary surgical procedures were performed in group TI. Surface replacement arthroplasty devices showed a tendency for a temporarily superior maximum postoperative ROM, but markedly higher postoperative complication and explantation rates were observed compared to the silicone spacer implantation.

Wrist & Hand

The June 2012 Wrist & Hand Roundup360 looks at; radial osteotomy and advanced Kienböck's disease; fixing the Bennett fracture; PEEK plates and four-corner arthrodesis,;carpal tunnel release and haemodialysis; degloved digits and the reverse radial forearm flap; occupational hand injuries; trapeziometacarpal osteoarthritis; fixing the fractured metacarpal neck and pyrocarbon implants for the destroyed PIPJ.

Outcomes of Pyrolytic Carbon Arthroplasty for the Proximal Interphalangeal Joint

Arthritis of the proximal interphalangeal joint is a debilitating condition commonly treated with arthroplasty. The pyrolytic carbon (pyrocarbon) implant has been developed for proximal interphalangeal joint arthroplasty in these patients. This prospective outcomes study evaluated the outcomes and complications of the pyrocarbon implant for the proximal interphalangeal joint. Consecutive candidates for proximal interphalangeal joint arthroplasty with pyrocarbon implants were evaluated prospectively. Functional measurements and the Michigan Hand Outcomes Questionnaire were administered preoperatively and at 3, 6, and 12 months postoperatively. Preoperative means and 12-month postoperative means for all functional measures were compared using paired t tests and nonparametric Wilcoxon signed rank sum test, and effect size was reported for the Michigan Hand Outcomes Questionnaire. Fourteen patients treated with 21 implants were enrolled in the study. At the 12-month follow-up period, mean active arc of motion was 38 degrees, decreasing slightly from the preoperative value. Mean grip strength improved from 11.3 kg to 15.1 kg, although the difference was not statistically significant. Mean key pinch values improved significantly from 6.6 kg preoperatively to 9.2 kg at the 12-month follow-up (p = 0.03). Jebsen-Taylor test scores showed improvement, although not significantly. Changes in all Michigan Hand Outcomes Questionnaire domains showed a large effect size. Three patients experienced squeaking of the implant and three patients experienced dislocation of the pyrocarbon joint. The pyrocarbon implant for proximal interphalangeal joint arthroplasty shows encouraging results, primarily in patient satisfaction and pain relief, but is associated with complications related to implant dislocations, which required prolonged treatment with external fixators.