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

Reported Outcomes and Outcome Measures in Proximal Interphalangeal Joint Arthroplasty: A Systematic Review

Purpose: There is a lack of scientific consensus on the best arthroplasty implant option for proximal interphalangeal joint (PIPJ) arthritis, due to diversity in outcome reporting and measurement methods. The development of a standardized core outcome set (COS) and standard outcome measures could mitigate this issue. This study catalogs the reported outcomes and outcome measures found in PIPJ arthroplasty studies, which can be used in the first step of developing a COS. Methods: A database search of MEDLINE, EMBASE, and Web of Science (January 1, 2010, to March 10, 2021) was performed to retrieve studies that reported outcomes of the 3 most common primary PIPJ arthroplasty implants: silicone, pyrocarbon, and metal-polyethylene. The primary objectives of this study include reported outcomes and outcome measures. Secondary objectives include clinimetric properties of outcome measures, study design, and implant types. Results: Fifty articles met inclusion criteria. Of the included studies, 41 (82%) were case series, 8 (16%) were cohort studies, and 1 (2%) was a randomized control trial. Thirty-three unique outcomes were identified. Fifteen (46%) outcomes were clinician-reported and 26 (79%) were patient-reported. Eighteen unique outcome measures were identified. Of the outcome measures, 15 (83%) were patient-reported, 1 (6%) was clinician-reported, and 2 (11%) were reported by both patients and clinicians. Conclusions: Substantial heterogeneity was found in reported outcomes and outcome measures across studies evaluating PIPJ arthroplasty, impeding knowledge translation. The development of a COS for PIPJ arthroplasty is necessary to help compare and pool data across studies, and advance scientific knowledge.

Proximal interphalangeal joint prosthetic arthroplasty

Surgical treatment of the painful proximal interphalangeal (PIP) joint has evolved considerably over the past century. If arthrodesis has long been the gold standard and remains so for some, prosthesis would meet patient demand: mobility and indolence. Faced with a demanding patient, the surgeon must decide the indication, the type of prosthesis, the approach, the post-operative follow-up, etc. The history of the development of PIP prostheses demonstrates the complexity of the treatment of the destroyed PIP: appearance of prostheses, evolution and sometimes disappearance from the market for commercial reasons or related to complications. The main objective of this conference is to identify the main indications for prosthetic arthroplasties and to describe the various prostheses available on the market.

Arthroplasty for destroyed proximal interphalangeal joint in hand trauma surgery: Silicone hinged NeuFlex® or gliding Tactys®?

The treatment of proximal interphalangeal joints (PIP) after a traumatic injury has produced disappointing outcomes. The objective of this study was to evaluate the functional results of emergency hinged or gliding arthroplasty for destroyed PIP joints. A two-center retrospective study was carried out in 24 patients with open and closed trauma of the PIP joint of the fingers from 2007 to 2019. Fifteen hinged silicone implants (NeuFlex®) and nine gliding implants (Tactys®) were used. Pain on a visual analog scale (VAS), stability and total active motion (TAM), grip and pinch strength (Jamar®), QuickDASH and PRWE and satisfaction were assessed, and X-rays were performed. With a mean follow-up of 48 months, 24 patients aged 58 years on average were reviewed. Pain on VAS was 0.2/10, the TAM was 72% of the contralateral side, the QuickDASH was 15.6/100 and the PRWE was 24.5/100. PIP flexion was ≥50% of the contralateral side in 75% of patients. PIP and DIP extensor lag of 9° was significantly larger with the Tactys® than with the NeuFlex®, with no significant difference in the TAM. Three clinodactylies in fingers with the NeuFlex® and three reducible swanneck deformities in fingers with the Tactys® were noted. Three-quarters of patients were very satisfied or satisfied with the outcome. Emergency PIP arthroplasty with Tactys® seems to provide functional results that are as good as with NeuFlex®. Clinodactyly was found with NeuFlex® use. A significant PIP and IPD extensor lag of 9° and swan-neck deformities were found with Tactys® without significant functional impairment.

Is a Vascularized Interphalangeal Unicondylar Transfer Worth the Efforts? Surgical Technique and Clinical Application

Interphalangeal joints (IPJ) play a key role in hand function for performing activities of daily living and are frequently involved in complicated injuries resulting in significant functional limitations such as secondary arthritis and stiffness being the most challenging. In adult patients with more than 5 mm bone loss of the proximal articular surface who request a functional interphalangeal joint with minimal pain a vascularized joint transfer is a treatment choice. A unicondylar loss more than 5 mm wide in a 22-year-old carpenter is reported and illustrates our experience with a vascularized unicondylar transfer showing the advantages compared to the "classic" total joint transfer or distal interphalangeal (DIP) joint arthrodesis. By using this technique at the 12-month follow-up, we achieved no donor site complications, a good graft alignment, a good joint congruity, complete bone healing and a normal vascular patency with no signs of bone malunion or resorption of the graft.

Systematic review of the introduction, early phase study and evaluation of pyrocarbon proximal interphalangeal joint arthroplasty

BACKGROUND

In 2002 a pyrocarbon interphalangeal joint implant was granted Food and Drug Administration approval with limited evidence of effectiveness. It is important to understand device use and outcomes since this implant entered clinical practice in order to establish incremental evidence, appropriate study design and reporting. This systematic review summarised and appraised studies reporting pyrocarbon proximal interphalangeal joint arthroplasty.

METHODS

Systematic review of MEDLINE, EMBASE, SCOPUS, Web of Science, BIOSIS, CINAHL and CENTRAL from inception to November 2020. All study designs reporting pyrocarbon proximal interphalangeal joint arthroplasty in humans were included. Data extracted included information about study characteristics, patient selection, regulatory (gaining research ethics approval) and governance issues (reporting of conflicting interests), operator and centre experience, technique description and outcome reporting. Descriptive and narrative summaries were reported.

RESULTS

From 4316 abstracts, 210 full-text articles were screened. A total of 38 studies and 1434 (1-184) patients were included. These consisted of three case reports, 24 case series, 10 retrospective cohort studies and one randomised trial. Inclusion and exclusion criteria were stated in 25 (66%) studies. Most studies (n = 27, 71%) gained research ethics approval to be conducted. Six studies reported conflicting interests. Experience of operating surgeons was reported in nine (24%) and caseload volume in five studies. There was no consensus about the optimal surgical approach. Technical aspects of implant placement were reported frequently (n = 32) but the detail provided varied widely. Studies reported multiple, heterogenous outcomes. The most commonly reported outcome was range of motion (n = 37).

CONCLUSIONS

This systematic review identified inconsistencies in how studies describing the early use and update of an innovative procedure were reported. Incremental evidence was lacking, risking the implant being adopted without robust evaluation. This review adds to evidence highlighting the need for more rigorous evaluation of how implantable medical devices are used in practice following licencing.

Rehabilitation after proximal interphalangeal joint replacement: A structured review of the literature

Proximal interphalangeal (PIP) joint arthroplasty is an unsolved biomechanical challenge despite advances in materials and new implant designs. This leads to a high rate of complications. Moreover, there is heterogeneity in postoperative management according to the literature. The present structured review examined the therapeutic strategies utilized by physiotherapists to restore a functional finger chain and prevent postoperative complications following PIP joint replacement. Patients undergoing primary total PIP joint arthroplasty of the index, ring, middle or little finger were included. Articles published from 2008 onwards, in French or English, and reporting on PIP joint replacement and postoperative management, were included. Therapeutic strategies were organized according to the surgical approach. Details of splint strategies, mobilization and muscle strengthening and management of postoperative complications were collected. Forty-eight studies, 3 of which provided a description of surgical techniques, were included. In relation to hand function, most authors advocated joint mobilization (n = 45) and some recommended muscle strengthening (n = 4). Static (n = 43) and dynamic splints (n = 14) and buddy taping (n = 12) were frequently recommended to prevent and manage postoperative complications. Few studies (n = 13) reported wound assessment or control of postoperative edema. Precise recommendations concerning therapeutic strategies following PIP joint arthroplasty cannot be made based on available evidence. Specific protocols for rehabilitation following PIP joint replacement need to be clarified in future research.

Trends in Primary Proximal Interphalangeal Joint System and Revisions for Osteoarthritis of the Hand in the Medicare Database

Background: Proximal interphalangeal arthroplasty (PIPA) has been indicated for patients suffering from osteoarthritis (OA) or rheumatoid arthritis of the hand. Although there is extensive literature showing the outcomes of PIPA, there is paucity in the literature regarding trends of PIPA in patients with OA of the hand. The purpose of this study was to determine annual primary utilization and revision PIPA trends within the Medicare population with the use of an administrative database. Methods: A retrospective query was performed using the Medicare Standard Analytical Files from the PearlDiver database. Patients undergoing primary and revision PIPA with hand OA were queried using International Classification of Disease, Ninth Revision, and Current Procedural Terminology coding. Primary outcomes analyzed included annual and revision utilization of PIPA and demographic comparison of age, gender, and geographic location. Statistical analysis was primarily descriptive. An α value less than 0.05 was considered statistically significant. Results: The query returned 10 191 patients who underwent primary and revision PIPA between 2005 and 2013. Calculated annual growth rate for primary and revision PIPA was 2.40% and -0.03%, respectively (P < .001). Patients between the ages of 70 and 74 years represented most of the patients undergoing a primary PIPA, whereas patients between 65 and 69 years most commonly underwent a revision procedure. Regionally, primary and revision PIPA were most commonly performed in the South. Conclusion: The data demonstrate an increased use of primary PIPA utilization for patients with OA, whereas revision PIPA decreased. The increased use indicates the increasing demand for PIPA in the United States.

[Anatomy of the metacarpophalangeal and proximal interphalangeal finger joint with respect to arthroplasty]

BACKGROUND

Precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint is the basis for both indication and implantation of a finger joint prosthesis. Currently available finger joint prostheses inadequately take into account individual, ethnological, gender, age, and side differences. They can remain compromised despite the possible combination of their components.

OBJECTIVES

To elucidate which problems of finger joint arthroplasty exist due to the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joints.

METHODS

The anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint are described, and the problems and solutions of finger joint arthroplasty are presented.

RESULTS

Despite precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint, not all problems of finger joint arthroplasty have been solved. However, a modular surface replacement appears promising for the proximal interphalangeal joint.

CONCLUSIONS

Artificial joint replacement of the metacarpophalangeal and proximal interphalangeal joint is difficult with regard to morphology, small bone dimensions, complex biomechanics, and the strain of the hand. Further improvements, especially in design, should be achieved by exact anatomical imitation.

Complications, reoperations and revisions after proximal interphalangeal joint arthroplasty: a systematic review and meta-analysis

This systematic review and meta-analysis investigates the prevalence of complications, reoperations (surgeries without implant modifications) and revisions (surgeries with implant modifications) after proximal interphalangeal joint arthroplasty with pyrocarbon, metal-polyethylene and silicone implants. Thirty-four articles investigating 1868 proximal interphalangeal joints were included. Implant-related complications were associated with 14%, 10% and 11% of the pyrocarbon, metal-polyethylene and silicone implants, respectively, yet these rates were not significantly different from one another. Silicone implants showed more finger deviations (3%) and instabilities (2%) compared with the other implants. Reoperations were fewer for silicone arthroplasties (1%) compared with pyrocarbon (7%) and metal-polyethylene implants (10%). The revision rates of 4%, 3% and 2% were similar for pyrocarbon, metal-polyethylene and silicone implants. Our results indicate that silicone implants remain a valuable option for the treatment of stable proximal interphalangeal joints. Surface replacing implants might be better to correct unstable or deviated proximal interphalangeal joints, although they are associated with a higher risk of reoperations.

[Advances in small joint reconstruction and arthroplasty of the hand]

Since Swanson designed the silicone small joint prosthesis, the material and design of the small joint prosthesis have been constantly innovating. The number of small joint reconstruction and arthroplasty has gradually increased in the past decade. The numerous studies have focused on design and application of new material prosthesis and its long-term effectiveness analysis, in order to overcome prosthesis loosening, shift, dislocation, and poor function problem, at the same time to challenge the difficulty of the small joints revision procedures. Although the small joint prosthesis which has got the overall performance of the Swanson joints and been mature and stable like a knee joints prosthesis has not been obtained, but the small joint development has made revolutionary changes in the treatment of joint diseases, and the prosthesis selection criterion and surgical technique tendency solution have been established. In the future, digital three-dimensional printing, regenerative medicine, and translational medicine will contribute to the development of small joint reconstruction and replacement.

A Systematic Review of Different Implants and Approaches for Proximal Interphalangeal Joint Arthroplasty

BACKGROUND

Outcomes after implant arthroplasty for primary degenerative and posttraumatic osteoarthritis of the proximal interphalangeal joint were different according to the implant design and surgical approach. The purpose of this systematic review was to evaluate outcomes of various types of implant arthroplasty for proximal interphalangeal joint osteoarthritis, with an emphasis on different surgical approaches.

METHODS

The authors searched all available literature in the PubMed and EMBASE databases for articles reporting on outcomes of implant arthroplasty for proximal interphalangeal joint osteoarthritis. Data collection included active arc of motion, extension lag, and complications. The authors combined the data of various types of surface replacement arthroplasty into one group for comparison with silicone arthroplasty.

RESULTS

A total of 849 articles were screened, yielding 40 studies for final review. The mean postoperative arc of motion and the mean gain in arc of motion of silicone implant with the volar approach were 58 and 17 degrees, respectively, which was greater than surface replacement implant with the dorsal approach at 51 and 8 degrees, respectively. The mean postoperative extension lag of silicone implant with the volar approach and surface replacement with the dorsal approach was 5 and 14 degrees, respectively. The revision rate of silicone implant with the volar approach and surface replacement with the dorsal approach was 6 percent and 18 percent at a mean follow-up of 41.2 and 51 months, respectively.

CONCLUSION

Silicone implant with the volar approach showed the best arc of motion, with less extension lag and fewer complications after surgery among all the implant designs and surgical approaches.

Radiographic and surgical considerations in arthritis surgery of the hand

Indications for hand surgeries include unremitting joint pain, deformity and stiffness, often secondary to arthritis. Several surgical options are available, including arthrodesis (fusion) and joint arthroplasty. Classically arthrodesis is performed in situations with poor bone stock and supporting soft tissues. Arthroplasty is reserved for patients and joints in which preservation of function is important and bone stock and soft tissue support are adequate. In this article we will review various techniques for arthrodesis and arthroplasty, their post-surgical imaging appearance, including key findings important to surgeons, and the findings that indicate post-surgical complications. Radiographs are the mainstay for postoperative evaluation and will be the focus of the imaging portions of this review. Advanced imaging modalities will be reviewed when applicable.

Proximal interphalangeal (PIP) joint replacements with pyrolytic carbon implants in the hand

Until the late 1980s, proximal interphalangeal (PIP) joint reconstruction had been almost exclusively performed by the use of monobloc silicone spacers and associated with acceptable to good clinical outcomes.

More recently, new materials such as metal-on-polyethylene and pyrocarbon implants were proposed, associated with good short-term and mid-term results.

Pyrocarbon is a biologically inert and biocompatible material with a low tendency to wear. PIP pyrolytic implants are characterised by a graphite core, visible on radiographs and covered by a radiolucent outer layer of pyrocarbon.

New surgical techniques and better patient selection with tailored rehabilitative protocols, associated with the knowledge arising from the long-term experience with pyrocarbon implants, has demonstrated noteworthy clinical outcomes over the years, as demonstrated by recent studies.

Cite this article: EFORT Open Rev 2017;2:21–27. DOI: 10.1302/2058-5241.2.160041

Clinical outcomes of ceramicized ball heads in total hip replacement bearings: a literature review

BACKGROUND

Metallic ball heads for total hip replacement (THR) bearings with ceramicized surfaces were introduced in orthopedics during the second half of the 1980s, with the aim of decreasing the wear of polyethylene cups.

METHODS

An analysis was made of the literature regarding outcomes for metallic ball heads with ceramicized surfaces now in clinical use (TiN, TiNbN, ZrN, monoclinic ZrO2), as well as carbon coatings (pyrolytic carbon, diamond-like carbon) and silicon nitride as coatings in ball heads for THR bearings.

RESULTS

Notwithstanding the diffusion of ceramicized ball heads in THRs, there are few reports about their clinical outcomes in hip arthroplasty. In addition, several clinical studies and some registry data are putting under scrutiny the clinical advantages of ceramicized ball heads over cobalt chrome (CoCr) alloy and ceramic ball heads.

CONCLUSIONS

The wear of THR bearings with ceramicized ball heads looks like it depends more on the behavior of the polyethylene cups than on the treatment of the ball head surface. The risk of coating damage and of its consequences has to be taken into account in selecting this type of bearing.

[Operative therapy for rheumatoid arthritis of the hand]

The need for operative treatment of severe rheumatic deformities of the hand and wrist is decreasing due to the increased use of disease-modifying drugs; however, some patients do not tolerate or do not sufficiently respond to these drugs, which often results in the hands being affected and in advanced stages to severe deformity and loss of function. In these cases operative surgery can help to slow the progression of rheumatic destruction and restore the function of the patient's hand. This article describes the principles of surgery for rheumatoid arthritis of the hand. A meticulous synovectomy or tenosynovectomy is the first stage of treatment. With progression of rheumatic destruction various salvage procedures are necessary to preserve the best possible functional state.

Pyrocarbon proximal interphalangeal joint arthroplasty: a medium to long term follow-up of a single surgeon series

We retrospectively reviewed a consecutive single surgeon series of 57 Ascension pyrocarbon proximal interphalangeal joint arthroplasties, with a mean follow-up of 7.1 years (range 2 years to 11 years 6 months). We assessed the ranges of motion, deformity, stability and pain of the operated joints, grip strength of the hand and patient satisfaction. Of the cases, 44 were for osteoarthritis, five for rheumatoid arthritis and eight for post-traumatic arthritis. The median post-operative active arc of motion was from 0° to 60°. The median post-operative visual analogue pain score was 0.3 out of ten. Thirty six of the joints had no complications; 14 had minor complications (squeak, slight swan neck); three required early reoperation (joint release, flexor tenodesis); and five required implant removal. A total of 69% of our patients would have the same operation if they had to make the decision again. The Kaplan-Meier survival method estimates the mean implant survival to be 10.7 years (95% confidence intervals 9.96-11.37 years). All five failures occurred during the first 2 years.Level of evidence 4 (Case-series).

Pyrocarbon Proximal Interphalangeal Joint Arthroplasty: Minimum Five-Year Follow-Up

PURPOSE

To report the outcomes, complications, and survivorship of pyrocarbon proximal interphalangeal joint arthroplasty at a minimum of 5-year follow-up.

METHODS

A review of 97 implants in 72 consecutive patients from our joint arthroplasty database was undertaken. Patient demographics, complications, further surgery, and implant revision were recorded. Objective outcome was assessed by grip strength, range of motion, and radiological assessment of alignment, loosening, and subsidence. Subjective outcome was assessed by Patient Evaluation Measure; Quick Disabilities of the Arm, Shoulder, and Hand score; and visual analog scores (0, best; 10, worst) for appearance, satisfaction, and pain.

RESULTS

Diagnosis was osteoarthritis in 60 joints, rheumatoid arthritis in 12 joints, psoriatic arthritis in 11 joints, and trauma in 14 joints. The average follow-up was 118 months (range, 60-164 months). The mean arc of motion was 35° (range, 0° to 90°). There was no difference in grip strength between operated and nonoperated side. Of the 97 implants, 36 required additional surgery, of which 14 were revised and 22 required reconstruction around a retained implant. The average Patient Evaluation Measure and Quick Disabilities of the Arm, Shoulder and Hand scores were 33 (range, 10-69) and 35 (range, 0-93), respectively. Mean visual analog scores for pain, satisfaction, and appearance were 2 (range, 0-8), 7 (0-10), and 8 (0-10), respectively. All implants had a lucent line with nearly all classified as either Herren grade 2 or 3. Progressive loosening was seen in 48% of implants. Implant survival as assessed by Kaplan-Meier was 85% at both 5 and 10 years.

CONCLUSIONS

Good pain relief and maintenance of preoperative arc of motion was achieved with no major deterioration over time. Most implant revisions were performed within 24 months of the index procedure. Currently progressive loosening was not translated into revision surgery. Implant revision rate was higher than with other prostheses.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A modular surface gliding implant (CapFlex-PIP) for proximal interphalangeal joint osteoarthritis: a prospective case series

PURPOSE

To evaluate the one-year postoperative clinical and patient-rated outcomes in patients receiving proximal interphalangeal (PIP) joint arthroplasty with a modular surface gliding implant, CapFlex-PIP.

METHODS

10 patients each with primary osteoarthritis of a single PIP joint were assessed preoperatively (baseline), at 6 weeks, and 3, 6, and 12 months after CapFlex-PIP arthroplasty for lateral stability and range of motion of the affected digit. In addition, patients rated their pain using a numeric rating scale and function and overall assessment of their treatment and condition using the quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Patient Evaluation Measure (PEM) questionnaires, respectively.

RESULTS

The mean baseline active mobility of the affected PIP joint increased from 42° to 51° by one year, although this change was not significant. Patients reported reduced pain at one year, which was statistically significant. There was also a significant improvement between baseline and one-year QuickDASH (43 points vs 15 points, respectively) and PEM scores (51 vs 25 points, respectively). Absent or low lateral instability was observed in 9 joints at follow-up. All implants remained intact over the one-year postoperative period and there was no migration, osteolysis, or implant fracture. After study completion, 2 patients underwent tenolysis.

CONCLUSIONS

Patients experienced a significant reduction in pain and a trend towards increased mobility. All implants showed complete osteointegration without evidence of radiological migration. Lateral stability improved.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Insertion of the Ascension PyroCarbon PIP total joint in 152 human cadaver fingers: analysis of implant positions and malpositions

INTRODUCTION

The Ascension PyroCarbon proximal interphalangeal (PIP) total joint is used in osteoarthritis of the PIP finger joint. No systematic study of the positioning of this prosthesis and its relation to proximal and middle phalanx morphology has yet been reported.

MATERIALS AND METHODS

Positioning of the proximal and distal components of the Ascension PyroCarbon PIP total joint was radiographically analysed in 152 human cadaver fingers.

RESULTS

Ideal implant position in the axis of the phalanx and with contact of the implant head with bone in both the frontal and sagittal planes was seen in only 33 % of the phalanges. Implant malposition was observed in the remaining 67 % of phalanges.

CONCLUSION

The current design of the Ascension PyroCarbon PIP total joint can lead to malpositioning that we attribute to its incomplete accommodation of the morphology of the proximal and middle phalanx, the surgical challenges the design poses, or both acting together.

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.

Ten years' experience with a pyrocarbon prosthesis replacing the proximal interphalangeal joint. A prospective clinical and radiographic follow-up

We prospectively assessed the subjective, objective, and radiographic results at 1, 2, and 5 years in 65 patients who had pyrocarbon proximal interphalangeal prostheses inserted between 2001 and 2010. Further operations were done on 10 of the 89 joints (four for prosthetic extraction and arthrodesis, two for component changes, and four for soft tissue procedures). At 1 year, the visual analogue scale score for pain at rest had improved to 0 cm from a pre-operative 4 cm, pain at activity from 6 to 1.8 cm, and Disability of the Arm, Shoulder and Hand score from 40 to 25. Range of movement and grip strength were unchanged. At 5 years, 31 joints (21 patients) had a complete radiographic follow-up. Seven proximal and 12 distal components showing zones of osteolysis at 1 year had stabilized and were inert or integrated at 5 years. Three proximal and three distal components had osteolytic zones at 5 years. Forty-seven of 59 patients were pain-free at rest at 1 year, and 19 of 21 at 5 years. No late revisions or loosening occurred.

Morphology of the proximal and middle phalanx of fingers with regard to the Ascension PyroCarbon PIP total joint

The Ascension PyroCarbon prosthesis has been used in proximal interphalangeal joint osteoarthritis. The dimensions of the intramedullary distal metadiaphyseal canal (isthmus) of the proximal phalanx and the base of the middle phalanx of cadaver fingers were investigated radiographically (n = 304) and macroscopically (n = 152). In up to 30% of the phalanges, the isthmus was smaller than the stem of the smallest proximal component size. The distal component head was always smaller than the middle phalanx base. Insertion and success of the Ascension PyroCarbon prosthesis is strongly dependent on bone morphology. A critical examination of the isthmus in radiographs is recommended in planning. If the isthmus is clearly smaller than the smallest proximal component, insertion of the prosthesis could be inadvisable. A clear mismatch between the distal component and the middle phalanx base should be avoided due to the potential risk for late subsidence and failure of the prosthesis.