The effect of cup orientation on stability of trapeziometacarpal total joint arthroplasty: a biomechanical cadaver study

Computer-simulated TOUCH prosthesis cup malposition and solutions

INTRODUCTION

Total joint replacement has become significantly more common as a treatment for advanced trapeziometacarpal joint osteoarthritis in recent years. The latest generation of prostheses with dual-mobility designs leads to very good functional results and low rates of loosening and dislocation in the short and medium term. Biomechanical studies showed that central placement and parallel alignment of the cup with respect to the proximal articular surface of the trapezium are crucial for both cup stability and prevention of dislocation. Despite correct positioning of the guidewire, incorrect placement or tilting of the inserted cup may occur, requiring immediate intraoperative revision.

METHODS

The existing spherical and conical cup models in sizes 9 mm and 10 mm were transferred to a computer-aided design dataset. Depending on the intraoperative complication (tilting or incorrect placement), the revision options resulting from the various combinations of cup type and size were simulated and analyzed according to the resulting defect area and bony contact area.

RESULTS

In well centered cups, a size 9 conical cup could be replaced by a size 9 spherical cup and still be fixed by press-fit. Conversely, a size 9 spherical cup could not be replaced by a size 9 conical cup, but only by a size 10 cup, of whatever shape. When a size 9 conical cup was tilted up to 20°, the best revision option was to resect the sclerotic margin and insert a size 10 conical cup deeper into the cancellous bone, to achieve the largest contact area with the surrounding bone. When a size 9 cup of whatever shape was poorly centered (misplaced with respect to the dorsopalmar or radioulnar line of the trapezium), placement should be corrected using a size 10 cup, combined with autologous bone grafting of the defect. Again, the size 10 conical cup showed the largest bony contact area.

CONCLUSION

Our computer-based measurements suggested options for intraoperative cup revision depending on cup shape and size and on type of misalignment with resulting bone defects. These suggestions, however, need to be confirmed in anatomic specimens before introducing them into clinical practice.

[Cup Placement in Thumb Carpometacarpal Joint Prostheses: The Role of the Guidewire]

BACKGROUND

The increasing use of thumb carpometacarpal joint prostheses for advanced CMC 1 (carpometacarpal) joint arthritis reflects the success of the latest prosthesis generations, which has been achieved through their improved functional outcomes and lower complication rates. Precise alignment of the prosthesis cup parallel to the proximal joint surface of the trapezium is essential for stability and the prevention of dislocation. This is a challenging surgical step, particularly for surgeons new to this technique. Despite adequate positioning of the guidewire, misplacements of the cup may occur, necessitating intraoperative revision.

MATERIAL AND METHODS

This study examined the deviations in cup and guidewire positioning in thumb carpometacarpal joint prosthesis implantations by inexperienced and experienced surgeons through radiological analysis of 65 prostheses.

RESULTS

Both inexperienced and experienced surgeons achieved precise guidewire positioning with mean deviations of<2.2°. Inexperienced surgeons showed significantly larger cup deviations in the dorsopalmar and lateral view (7.6±6.1° and 7.3±5.9°) compared with experienced surgeons (3.6±2.7° and 3.6±2.5°; p=0.012, p=0.017). The deviation of the cup position exhibited by inexperienced surgeons tends to be in the direction opposite to the initial guidewire position (p<0.0038).

CONCLUSION

The results highlight the current challenges in cup positioning depending on a surgeon's level of experience, questioning the reliability of the current guidewire placement.

[Current Trends in the Implantation of the Touch Prosthesis at the Thumb Carpometacarpal Joint: Results of the 1st German-Speaking User Meeting]

The introduction of the new generation of thumb carpometacarpal (CMC I) joint implants for the treatment of CMC I osteoarthritis has significantly broadened the scope of hand surgery in recent years. However, the technical demands of the procedure and the many details that need to be considered require appropriate training and a learning curve. To share experiences with the Touch CMC I prosthesis, we held the first German-speaking CMC I joint prosthetics user meeting in Zurich. After some basic introductory lectures on biomechanics and the principles of prosthetic fitting of the CMC I joint, the various challenges associated with CMC I joint prosthetics were discussed in interactive expert panels. Subsequently, cases were discussed in small groups under expert guidance and the respective conclusions were discussed in plenary. The main results of this symposium are summarised in this manuscript.

[Translated article] Experience in major complications with total trapezometacarpal prostheses

INTRODUCTION

The treatment of rhizarthrosis using trapeziometacarpal prostheses (TMP) is increasing. Complications may lead to loss of the implant and result in salvage surgery. Our aim was to assess major complications with the use of some TMP models and their rescue.

MATERIAL AND METHOD

Retrospective study on TMP implanted between 2006 and 2021. Models studied: Arpe®, Elektra®, Ivory®, Maïa®, Isis® and Touch®. Demographic data were assessed, implant placement by radiographic study, technical data, complications, salvage surgeries and final survival.

RESULTS

Review of 224 TMP, 45 Arpe® (95.5% survival, rate follow-up [R] 6-16 years), 5 Elektra® (80% survival, R 13-14), 14 Ivory® (92.8% survival, R 9-11), 7 Maïa® (100% survival, R 8-9), 115 Isis® (99.1% survival, R 1-8), 38 Touch® (100% survival, R 1-4). The medial angle of the dome with the proximal articular surface of the trapezium in the lateral plane, was: Arpe®: 8.85°, Elektra®: not assessable, Ivory®: 6.6°, Maïa®: 14.4°, Isis®: 3.8°, and Touch®: 5.95°. The Isis® was placed 100% with scopic guidance presenting a significantly lower angle respect to the medial angle of the dome with the proximal articular surface of the trapezium. As main complications, we observed 3.5% of dislocations and 4% of mobilisations, with the Elektra® being responsible for 47% of these. Nineteen salvage surgeries were performed, with 3% of the implants being lost.

CONCLUSIONS

Dislocation and mobilisation are the most observed complications, the Elektra® responsible for almost half of them. Correct placement and implant design appear to be crucial to avoid them in the short and long term.

Experience in major complications with total trapezometacarpal prostheses

INTRODUCTION

The treatment of rhizarthrosis using trapeziometacarpal prostheses (TMP) is increasing. Complications may lead to loss of the implant and result in salvage surgery. Our aim was to assess major complications with the use of some TMP models and their rescue.

MATERIAL AND METHOD

Retrospective study on TMP implanted between 2006 and 2021. Models studied: Arpe®, Elektra®, Ivory®, Maïa®, Isis® and Touch®. Demographic data were assessed, implant placement by radiographic study, technical data, complications, salvage surgeries and final survival.

RESULTS

Review of 224 TMP, 45 Arpe® (95.5% survival, rate follow-up [R] 6-16 years), 5 Elektra® (80% survival, R 13-14), 14 Ivory® (92.8% survival, R 9-11), 7 Maïa® (100% survival, R 8-9), 115 Isis® (99.1% survival, R 1-8), 38 Touch® (100% survival, R 1-4). The medial angle of the dome with the proximal articular surface of the trapezium in the lateral plane, was: Arpe®: 8.85°, Elektra®: not assessable, Ivory®: 6.6°, Maïa®: 14.4°, Isis®: 3.8°, and Touch®: 5.95°. The Isis® was placed 100% with scopic guidance presenting a significantly lower angle respect to the medial angle of the dome with the proximal articular surface of the trapezium. As main complications, we observed 3.5% of dislocations and 4% of mobilisations, with the Elektra® being responsible for 47% of these. Nineteen salvage surgeries were performed, with 3% of the implants being lost.

CONCLUSIONS

Dislocation and mobilisation are the most observed complications, the Elektra® responsible for almost half of them. Correct placement and implant design appear to be crucial to avoid them in the short and long term.

Failure Rate and Early Complications of Thumb Carpometacarpal Joint Replacement-A Multicenter Retrospective Study of Two Modern Implant Designs

Joint replacement arthroplasty for the treatment of thumb osteoarthritis is gaining popularity as recent studies have demonstrated better pinch and grip strength and faster rehabilitation. Our aim was to identify early complications in modern implant designs using a multicenter study. A total of 381 patients who underwent thumb carpometacarpal replacement surgery in six participating hospitals were enrolled. The complications included were fractures, dislocations, infections, tendon and nerve injuries, and complex regional pain syndrome. Major complications were defined as a failure to implant the prosthesis, revision surgery to remove the implant, and any other need for further surgical intervention. The secondary outcomes were any other complications treated non-surgically and the timing of the complications. Eleven procedures failed, and these patients were treated with trapeziectomies. Twelve other patients required repeat surgical interventions. Minor adverse events occurred in 25.4% of the cases, and transient irritation of the superficial radial nerve and De Quervain tendinopathy were the most prevalent complications. Although this cohort depicted the learning curves of multiple surgeons, our study demonstrated low short-term failure rates. An inability to achieve primary stability of the cup in the trapezium was the leading cause of failure. Dislocations and other major complications with modern implants were very few.

Total joint arthroplasty versus trapeziectomy in the treatment of trapeziometacarpal joint arthritis: a randomized controlled trial

The aim of this double anonymized, randomized controlled trial was to determine whether total joint arthroplasty has superior outcomes than trapeziectomy 1 year after surgery for trapeziometacarpal osteoarthritis. A total of 62 women aged 40 years and older, scheduled for surgery for stage II or III osteoarthritis of the trapeziometacarpal joint, were included and randomized to trapeziectomy or total joint arthroplasty. The primary outcome was the total score of the Michigan Hand Outcomes Questionnaire. Secondary outcomes were the Michigan Hand Outcomes Questionnaire subscale scores, Disability of the Arm, Shoulder and Hand Questionnaire, active range of motion, strength, return to work, patient satisfaction and complications. Data were collected at baseline and at 3 and 12 months. At 1 year, we found no superiority of total joint arthroplasty over trapeziectomy regarding the total score of the Michigan Hand Outcomes Questionnaire. The total joint arthroplasty did show a significant advantage in strength and range of motion.Level of evidence: I.

Time to return to work after total trapeziometacarpal prosthesis

OBJECTIVES

This study assessed return to work and prosthesis survival after trapeziometacarpal prosthesis surgery.

MATERIAL AND METHODS

A multicenter retrospective study was carried out on patients operated on between 2002 and 2020. All working patients who had undergone trapeziometacarpal prosthesis surgery were included. Return to work was defined as resuming the same full-time position. Postoperative events and their specific treatment and failure to return to work were reported.

RESULTS

240 prostheses in 211 patients were included. The complications rate was 7.5%, with 97% prosthesis survival. 94.3% of patients returned to work, at a mean 48 days (range, 29-210 days; SD, 22.7 days), with no significant difference according to age. Twelve patients did not return to work, half of whom because of prosthetic complications.

CONCLUSION

Trapeziometacarpal arthroplasty enables most patients to return to work within 6 weeks. In this series, the prosthetic survival rate was 97%.

Dual mobility prosthesis for trapeziometacarpal osteoarthritis: results from a prospective study of 55 prostheses

This prospective study evaluated outcomes after trapeziometacarpal joint replacement with a dual mobility prosthesis (Touch®) in 55 thumbs (52 patients) with a mean follow-up of 25 months (range 12-36). Pre- and postoperative assessments included pain, range of motion, the Kapandji index, pinch- and grip strength, as well as functional scores and radiological parameters. Mean preoperative metacarpophalangeal joint hyperextension of 19° (range 15°-28°) showed a significant correction after 1 year with a mean value of 2° (range 0°-5°). Mean Quick Disabilities of the Hand, Shoulder and Arm score was 14 (range 6-28), and Michigan Hand Questionnaire 82 (range 67-92). No revisions due to infection, loosening, dislocation or material failure occurred during follow-up. The dual mobility trapeziometacarpal joint prosthesis was a reliable treatment option to decrease pain, improve motion, strength and pre-existing metacarpophalangeal joint hyperextension at short-term follow-up.Level of evidence: IV.

New radiographic monitoring indices for total trapeziometacarpal prostheses

OBJECTIVE

The objective of this study is to propose and evaluate a method of monitoring implants via the calculation of a trapezial and metacarpal index from radiological measurements and to describe an initial patient analysis.

METHODS

This retrospective study describes the trapezial index which reflects the trapezial bone stock not occupied by the trapezial cup, while the metacarpal index reflects the rate of metacarpal occupation by the prosthetic stem. Those indexes were used on a series of 20 patients with a Maïa™ prosthesis with a minimum follow-up of seven years. The indexes were measured immediately postoperatively and at the various annual check-ups. Four observers measured each index on two occasions, to obtain an inter- and intra-observer correlation coefficient.

RESULTS

The average intra-observer correlation coefficient for the trapezium index was 0.94, for the metacarpal index 0.98. The inter-observer correlation coefficient was 0.93 for the trapezium index, 0.94 for the metacarpal index on average. The post-hoc calculated power was 0.98 as the number of subjects required was not usable. The mean immediate postoperative trapezial index was 45.74%, compared with a value at longest follow-up of 41.74%, reflecting a highly significant loss of height of 8,74%. The mean immediate postoperative metacarpal index was 77.69% compared with a mean value at longest follow-up of 78.99% indicating a non-significant increase in the index of 1,67%.

CONCLUSION

Proposed indexes had excellent inter- and intra-observer correlation, the metacarpal one is stable over time whereas the trapezial one reveals changes in some patients, requiring further investigations. These simple and reproducible indexes allow precise monitoring of trapeziometacarpal prostheses and identify radiographic changes that should lead to additional examinations to improve survival of implants.

LEVEL OF EVIDENCE

III, retrospective single cohort study.

Optimal Center of Rotation for Ball-And-Socket Thumb Carpometacarpal Arthroplasty Identified Using Three-Dimensional Kinematic Analysis: A Pilot Study

Total joint arthroplasty is one of the surgical option for thumb carpometacarpal (CMC) joint arthritis, however the optimal position the center of rotation (COR) has not been quantified. The purpose of this study is to identify ideal ball-and-socket thumb carpometacarpal joint implants and the optimal position of the COR. We obtained eight right thumb computed tomography images each from ten healthy men, comprising four images each of thumbs at various angles of flexion-extension and abduction-adduction. We reconstructed 3D bone models on 3D CAD, created virtual ball-and-socket implants with three variables (neck offset, implant height, neck rotation), and found the optimal COR where the position change in the COR was smallest across various thumb positions. When the offset was 4.5 mm, neck rotation angle was 130.6° from the radial side to the palmar side of the first metacarpal, and implant height from the distal end of the metacarpal was 43.6 mm, we could restore almost normal kinematics. This study could serve as a reference for implant development and surgical technique guidelines.

Total joint replacement for osteoarthritis of the carpometacarpal joint of the thumb: why and how?

Total joint replacement has certain advantages over other surgical treatment methods for osteoarthritis of the thumb carpometacarpal joint, including restoration of thumb length and alignment, good cosmetical result, fast recovery of hand function and prevention of iatrogenic complications at neighbouring joints. Disadvantages include the technical difficulty to perform this surgery and a possible higher complication rate. A meticulous surgical technique is mandatory. Combined with a cementless and modular ball-in-socket implant with a metal-on-polyethylene friction couple, a 10-year survival rate higher than 90% can be expected. Revision surgery is possible with implant exchange or conversion to trapeziectomy.

[Experiences with arthroplasty of the basal joint of the thumb : The"mini-hip" gains ground]

The complex kinematics of the saddle joint has been a challenge in the development of trapeziometacarpal prostheses. The introduction of the dual-mobility design increases the range of motion and limits strains on the cup fixation. Therefore, rates of loosening and dislocation have been markedly reduced. Furthermore, several studies showed a similar relief of pain, range of movement and grip strength compared to the results of resection arthroplasty. The preservation of the length of the first ray as well as the more stable and functional joint can be favourable in younger and active patients. Further investigation is needed to determine whether or not those higher demands affect long-term survivorship. The high grade of patient satisfaction, the shorter recovery time and the safe surgical technique motivates considering the implantation of a total endoprosthesis with a dual-mobility cup as an attractive alternative to resection arthroplasty in the operative treatment for trapeziometacarpal osteoarthritis.

Dual mobility trapeziometacarpal prosthesis: a prospective study of 107 cases with a follow-up of more than 3 years

We report the results of a prospective study using a dual mobility trapeziometacarpal prosthesis (Touch®) in 107 patients with a minimum follow-up of 3 years. One-hundred and two patients (95%) were very satisfied or satisfied with the functional outcomes and the mean pain intensity in visual analogue scale decreased from 7.4 to 0.8 (p < 0.001). Thumb opposition (Kapandji score) index increased from an average of 8.0 to 9.4, while the mean QuickDASH score improved from 38 preoperatively to 20 at follow-up (p < 0.01). Key-pinch strength improved from 3.5 kg (range 0.5-9.5) to 5.5 kg (range 3.0-11.5). There was a 4.6% rate of complications, including cup loosening and wear of polyethylene, which required revision, but no cases of prosthetic dislocation were seen. Applying the dual mobility principle to trapeziometacarpal arthroplasty may significatively improve the stability of these prostheses. Radiolucent zones around the components of the prostheses are not systematic predictors of future loosening.Level of evidence: IV.

Initial survival of the Isis® total trapeziometacarpal prosthesis with conical trunk threaded cups

INTRODUCTION

The treatment of trapeziometacarpal osteoarthritis through the implantation of total trapeziometacarpal prostheses is in continuous expansion. The Isis® prosthesis is a trunk-conical threaded anchorage prosthesis. Our objective was to assess the functional results and survival of this implant for at least one year of follow-up.

MATERIAL AND METHOD

Prospective study on 53 Isis® prosthesis, implanted from april 2014 to january 2019. The Van Cappelle functional test, pain, strength, mobility, return to previous activity, radiological variables and placement of the trapezial component were evaluated. The surgical technique was performed with a guide wirefocused on the trapezius and control of the scopia. Observed complications were recorded and statistical analysis was performed.

RESULTS

Fifty-one implants (49 patients) were reviewed. Mean follow-up was 2.1 years (1-5.7). Van Cappelle's test, pain, mobility, and grip and clamp strength improved significantly, as did the distance between the metacarpal head and the trapezius base; 96% of the patients returned in less than 6 months to their activities. Minor complications, 3 De Quervain's tendinopathy and 2 intra-operative metacarpal and 2 trapezium fractures were recorded, and one carpal tunnel syndrome. There was no dislocation, mobilization, or implant infection.

CONCLUSIONS

The functional results of the Isis® prosthesis are excellent in the short term, far exceeding the first year of 100% of survival. The complications that arose were minor and few. The anchorage and placement of the trapezial component guided by scopia seem to be crucial for the good result.

Primary endoprosthetic replacement of the arthritic CMC-1 joint

OBJECTIVE

Osteoarthritis of the carpometacarpal (CMC)-1 joint is a common condition that can cause significant pain and functional problems. When nonoperative management fails, surgery may be indicated. Resection of the trapezium, often combined with soft tissue stabilization, is still considered the gold standard. But recovery time is often prolonged and a significant number of patients remain unsatisfied in the long term. Knowing that total endoprosthetic joint replacement is one of the most successful achievements of orthopedic surgery, many attempts have been made to produce a replacement for the CMC‑1 joint that provides a better outcome than trapeziectomy.

INDICATIONS

Eaton-Glickel stage 2-3 CMC‑1 osteoarthritis.

CONTRAINDICATIONS

Symptomatic pan-trapezial osteoarthritis (Eaton-Glickel stage 4), infection, young manual worker, poor bone quality or insufficient trapezium size.

SURGICAL TECHNIQUE

A dorsoradial approach to the CMC‑1 joint is used. Minimal resection of the trapezial and metacarpal articular surfaces, including osteophytes and loose bodies. Reaming of the trapezium and broaching of the metacarpal stem with dedicated instruments. Implantation of the endoprosthetic components. Selection of the correct neck length to ensure a stable joint. Closure of the capsule and skin.

POSTOPERATIVE MANAGEMENT

Immobilization of thumb for 2 weeks in a splint. Followed by a removable thumb CMC brace for 4 weeks, starting with gentle mobilization exercises. No forceful gripping or pinching the first 6 weeks.

RESULTS

A specific design-the uncemented, ball in socket, metal on polyethylene total joint replacement-has stood the test of time and successful long-term clinical and radiographic outcome results have been published. Recent comparative trials have shown better pinch strength, better pain relief and faster functional recovery, when compared to trapeziectomy with ligament reconstruction and tendon interposition. The incidence of complications such as dislocation, polyethylene wear and cup loosening is acceptable.

The mechanical fixation of a cementless conical cup in cortical versus cancellous trapezial bone: an experimental study

In a pig bone model mimicking the human trapezium, we assessed the cementless fixation of trapezial cups in cancellous and cortical bone. Thirty-two saddle-shaped pig forefoot bones were prepared for cup fixation. Conical Konos cups (Beznoska, Kladno, Czech Republic) size 9 mm or 10 mm diameter were impacted. Cup migration was evaluated with repeated radiostereometry after intervals of cyclic-load tests. Migration increased for every load-interval up to 750 N and was higher with cancellous bone fixation than with cortical bone fixation. In cancellous bone, 9 mm cups migrated more than 10 mm cups. At the highest load (1050 N), the cumulative implant survival was 88% for 10 mm cups with cortical bone fixation and 13% for 9 mm cups with cancellous bone fixation. We conclude that mechanical fixation of conical Konos cups was better in cortical than in cancellous bone. Our results further suggest that the largest possible cup diameter should be used.

Revision procedures after trapeziometacarpal surgery

Surgical treatment of thumb basal joint arthritis generally yields good and excellent results. In case of failure, the surgeon will propose an appropriate solution to the patient, one that can be performed easily. Each technique has its own complications: shortening with trapeziometacarpal pain following trapeziectomy, loosening and instability following total arthroplasty, instability for some implants. There are also intolerances such as allergies to nickel, foreign body reactions to silicone and inflammatory reactions to some synthetic ligament implants. It is important to bear these complications in mind when determining the best possible surgical technique initially. The different surgical solutions are exposed here. Prosthetic replacement is preferred in case of loosening when it is technically possible in order to preserve the thumb's length. A conversion to trapeziectomy with or without interposition (implant or ligament reconstruction) will be carried out in the other cases. In case of trapeziectomy failure, solutions are more difficult to find. In the current state of things, it seems that implant or biological tissue interposition is the best solution.

Trapeziometacarpal total joint arthroplasty: The effect of capsular release on range of motion

It has been suggested that trapeziometacarpal total joint arthroplasty be combined with complete release of the joint capsule to prevent ligament tethering and implant dislocation. Our goal was to evaluate the consequences of capsular release on range of motion. Trapeziometacarpal joint motion was measured with a 3D motion tracking system in seven fresh frozen human cadaver hands before and after capsular release and total joint arthroplasty with subsequently longer neck lengths. Relative to the native trapeziometacarpal joint with intact joint capsule, mean flexion-extension was significantly increased after the arthroplasty with released capsule and lengthening up to 6 mm. Mean abduction-adduction did not increase significantly. Total joint replacement combined with capsular release increases the trapeziometacarpal joint's range of motion, but not beyond the limits of most trapeziometacarpal implant designs. Lengthening of the implant neck progressively decreases the excess motion.