Trapeziometacarpal Joint Arthroplasty Research Articles

Dual Mobility Trapeziometacarpal Joint Arthroplasty: A Survey on Variations in Surgical Techniques and Patient Management.

Background: Dual mobility total joint arthroplasty is gaining popularity for trapeziometacarpal joint (TMCJ) arthritis, with evolving indications, surgical technique and rehabilitation. The aim of this study was to obtain detailed insight into the variations in indications, surgical technique and rehabilitation for TMCJ arthroplasty with dual mobility implants, across a large international cohort of surgeons. The secondary aim was to analyse if there were differences in TMCJ arthroplasty between highly and less experienced surgeons. Methods: An anonymised online survey was developed and distributed to the international hand surgery community of surgeons performing TMCJ arthroplasty. Responses were summarised, and a sub-analysis comparing indications, contra-indications, surgical technique, implant placement, rehabilitation and complications between highly and less experienced surgeons was performed. Results: Of the 203 included respondents, 59 were considered highly experienced. Most respondents perform TMCJ arthroplasty under regional anaesthesia (84%), via a dorsolateral approach (78%) and with image-guidance for cup placement (84%). However, there is considerable variation in handling of scaphotrapeziotrapezoidal (STT) arthritis, cup positioning landmarks, postoperative immobilisation, first extensor compartment release and revision techniques. Highly experienced surgeons performed TMCJ arthroplasty for a larger proportion of their patients undergoing surgery for TMCJ arthritis, and a trapezium smaller than 8 mm or STT-OA was less frequently considered a contra-indication. Highly experienced surgeons preferred freehand osteotomy of the metacarpal and allowed office workers to return to work earlier. Conclusions: This survey shows that there is considerable variation in (contra)indications, surgical technique and rehabilitation amongst surgeons performing TMCJ arthroplasty, but only a few differences between highly and less experienced surgeons were identified. This data provides a reference for surgeons who want to familiarise themselves with increasingly popular procedure and may help surgeons already performing TMCJ arthroplasty to identify potential topics for future research to optimise its outcome. Level of Evidence: Level V (Therapeutic).

MAÏA Trapeziometacarpal Joint Arthroplasty: Clinical and Radiological Outcomes of 76 Patients With More Than 10 Years of Follow-Up

Trapeziometacarpal (TMC) joint replacement has become a valid option in the therapeutic arsenal of TMC joint osteoarthritis in Europe. Good mid-term results of the MAÏA TMC joint prosthesis suggested that it is a reliable procedure. This study aimed to assess the long-term results of this modular uncemented ball-and-socket hydroxyapatite-coated implant. This single-center retrospective study evaluated 92 MAÏA TMC joint prostheses in 76 patients with a minimum of 10 years of follow-up. Indications for the procedure were painful TMC joint osteoarthritis both at rest and during activity, despite nonsurgical treatment for more than six months. Pre- and postoperative clinical and radiographic outcomes were compared. Mean follow-up was 134 months (range: 120-158 months). Mean age at the time of surgery was 67 years (range: 53-84 years). The cohort comprised 86.8% of women (n= 66). The mean Quick Disabilities of the Arm, Shoulder, and Hand score improved from 61.3 ± 17.1 to 19.6 ± 16. Range of motion was restored, and postoperative mobility was comparable with that of the contralateral side. Final Kapandji opposition score was almost normal (9.2 ± 0.7). Final key pinch and grip strength improved by 26% and 39%, respectively. Eight implants were surgically revised, six for trapezium cup loosening and two for instability because of polyethylene wear. Three cases of traumatic fracture of the trapezium in older patients were successfully treated with a cast for eight weeks. Five of 26 (20.8%) cases of preoperative-reducible z-deformity were not totally corrected after surgery. The Kaplan-Meier survival over 10 years was 88% (95% confidence interval: 84-93) versus 93% (95% confidence interval: 87-98) over 5 years. MAÏA TMC joint prosthesis is a reliable long-term surgical procedure for TMC joint osteoarthritis, improving overall function beyond 10 years. Therapeutic IV.

De Quervain tendinitis after total trapeziometacarpal joint arthroplasty: Biomechanical evaluation of tendon excursion in the first extensor tendon compartment

De Quervain’s tenosynovitis is the most common complication after total trapeziometacarpal joint replacement. Etiology is unclear. Implantation of a ball-in-socket implant changes the biomechanics of the normal trapeziometacarpal saddle joint and increases its range of motion. The present study demonstrates that this procedure also significantly increases excursion of the abductor pollicis longus and extensor pollicis brevis tendons during thumb flexion-extension, and not during thumb abduction-adduction. Increased tendon gliding under the retinaculum of the first extensor tendon compartment could predispose to the development frictional tenosynovitis and play a role in the development of de Quervain’s syndrome after total trapeziometacarpal joint replacement. Level of evidenceNot applicable (laboratory study).

Polyethylene liner fracture in dual mobility trapeziometacarpal total joint replacement: how to make a timely diagnosis?

We present a case of fracture of the polyethylene liner of a dual-mobility trapeziometacarpal total joint arthroplasty. Standard radiographic imaging was normal. This case highlights the importance of dynamic radiographic imaging to make a timely diagnosis.

Revisions after trapeziometacarpal joint resection arthroplasty: A systematic literature review.

The aim of this systematic literature review was to describe current indications and interventions for revisions after trapeziometacarpal joint (TMJ) resection arthroplasty. The literature search was conducted by an experienced librarian in the Medline, EMBASE, Cochrane Library, Web of Science and Scopus databases. We included all articles that investigated any TMJ arthroplasty procedure in which the trapezium was completely resected and if any subsequent revision procedure including joint-related and soft-tissue surgeries was mentioned. Two independent reviewers selected the articles and were involved in data extraction. Sixty-two articles reporting on 5,284 operated thumbs and 434 revision surgeries were included. We extracted 24 indications for revision and 31 revision techniques. Most revisions were performed because of subsidence/impingement of the first metacarpal bone (n=194 thumbs) followed by unspecified pain (n=53), metacarpophalangeal joint problems (n=28) and scaphotrapezoidal osteoarthritis (n=17). Eleven treatment strategies were found for subsidence/impingement of the first metacarpal, the most frequent being revision of the existing interposition using autologous tendon (n=46) and soft tissue interposition with distraction pinning (n=28). There are a wide variety of indications and even more surgical techniques described in the literature to treat persisting or recurrent pain after TMJ resection arthroplasty. Currently, there is no uniform treatment guideline available how to diagnose and treat such cases. Therefore, the results of this literature review will form the basis for a Delphi study aiming to develop recommendations for the diagnosis and treatment of persistent / recurrent pain after TMJ resection arthroplasty. IV.

Functional survival of cementless trapeziometacarpal total joint arthroplasty after upper extremity trauma

IntroductionOur purpose with this publication is to document the survival of uncemented and unconstrained total trapeziometacarpal arthroplasty after energy trauma to the upper extremity. Material and MethodsFrom 1999 to the present, ten patients carrying total TMC arthroplasty suffered major traumatic injuries on the hand. Eight patients had fractures of the distal radius, one patient had scapho-lunate dissociation and one patient had a dorsal pullout of the triquetrum. A clinical and radiological examination of the patients after the trauma was carried out and compared with the pre-traumatic prosthesis status. ResultsThree patients required surgical intervention for the associated traumatic injury. The postraumatic clinical and functional follow-up of the patients was good, and no differences were documented with respect to mobility, strength and pain at the level of the thumb with respect to the prior to the trauma. No signs of loosening, instability or alteration in the alignment of the components of the protheses were observed in the radiological examinations following the trauma. ConclusionsThere is a high survival rate of uncemented total trapeziometacarpal arthroplasty in the long term, even in the face of energy trauma. It is then a safe implant. Despite of being non-constrained, a good alignment of the prosthetic components is the key to avoid dislocation of the prosthesis.

Low complication rate and high implant survival at 2 years after Touch® trapeziometacarpal joint arthroplasty.

We analysed complications, revision surgeries, and patient-reported and clinical outcomes 2 years after trapeziometacarpal joint implant arthroplasty using the Touch® prosthesis. Of 130 operated patients with trapeziometacarpal joint osteoarthritis, four had to be revised owing to implant dislocation, loosening or impingement, leading to an estimated 2-year survival rate of 96% (95% confidence interval: 90 to 99). Of 101 patients available for the 2-year follow-up, complications occurred in 17, with the most frequent being de Quervain stenosing vaginosis (n = 6) and trigger thumb (n = 5). Pain at rest decreased significantly from a median value of 5 (interquartile range [IQR]: 4 to 7) before surgery to 0 (IQR: 0 to 1) at 2 years. Key pinch strength increased significantly from 4.5 kg (IQR: 3.0 to 6.5) to 7.0 kg (IQR: 6.0 to 8.0). We recommend surgery with the Touch® prosthesis as the standard procedure for patients with isolated trapeziometacarpal joint osteoarthritis because of the high survival rate and promising outcomes at 2 years.Level of evidence: IV.

Assessment of trapezial prosthetic cup migration: A biomechanical study

We performed a biomechanical study using 60 Sawbones® rigid foam blocks of two simulated densities (osteoporotic, n = 30 and non-osteoporotic, n = 30) and 10 cadaveric trapezium bones from fresh-frozen, unembalmed adult cadaver hands to assess the trapezial prosthetic cup migration with progressively greater compression loads (10–40 kg). Two cups from the Touch® prosthesis were compared: 9-mm conical cup and 9-mm spherical cup. Uniaxial compression tests were carried out using an MTS Criterion® Series 40 Electromechanical Testing System. Cup migration was measured in millimeters (mm) at 10, 20, and 40 kg of compression load. Median cup migration values were similar in the cadaveric trapezium bones and Sawbones® non-osteoporotic blocks, and higher in the Sawbones® osteoporotic blocks. In the cadaveric trapezium bones and the Sawbones® non-osteoporotic blocks, migration values were less than or equal to 0.1 mm for 10 and 20 kg loads; it was 0.2 mm for 40 kg load. In the Sawbones® osteoporotic blocks, migration values were less than or equal to 0.3 mm for 10 and 20 kg loads; it was 0.4–0.5 mm for 40 kg load. There was no significant difference between the two cup shapes in both cadaveric trapezium bones and Sawbones® non-osteoporotic blocks. In Sawbones® osteoporotic blocks, the largest difference between the two cup shapes was 0.1 mm for loads up to 40 kg, which corresponded to our measurement accuracy. Our findings indicate that the trapezial component of total trapeziometacarpal joint arthroplasty undergoes very weak migration for axial compression loads up to 40 kg, presumably below the threshold of clinical relevance. The cup shape did not have an obvious influence; however, low bone mineral density may result in greater cup migration.

Influence of Occupational Hand Force Requirements on Return to Work, Pain, and Disability After Trapeziometacarpal Total Joint Arthroplasty: A 12-Month Follow-Up Study

We aimed to determine the prognosis after trapeziometacarpal total joint arthroplasty for basal thumb osteoarthritis with respect to sustainable return to work (RTW), pain, and disability. Our main hypothesis was that high occupational hand force requirements are related to slower RTW. We conducted a 12-month follow-up study of patients who were treated with a trapeziometacarpal total joint arthroplasty in 2003 to 2015 and were active in the labor market at the time of surgery. We used registry information about RTW. Before surgery and at the 12-month follow-up, we obtained data on pain and disability. To obtain estimates of occupational hand force requirements for individual patients, we linked the patients' self-reported job title to a job exposure matrix based on experts' ratings. We used Cox regression models to analyze the time until sustainable RTW and logistic regression models to analyze pain and disability. A total of 133 patients were included. Most patients returned to work within 12 months after surgery (86%). For those who returned to work within 12 months (n= 114), mean time until sustainable RTW was 14 weeks (SD, 9 weeks). Higher hand force requirements were associated with slower RTW (for medium- and high-force requirements, adjusted hazard ratios were 0.48 [95% confidence interval, 0.30-0.78] and 0.41 [95% confidence interval, 0.25-0.69]). Occupational hand force requirements were not associated with pain and disability at follow-up. High occupational hand force requirements were associated with slower RTW, but not with pain and disability 12 months after surgery. Prognostic I.

Revision rates of trapeziometacarpal total joint arthroplasty in relation to occupational hand force requirements.

The purpose was to determine revision rates after trapeziometacarpal total joint arthroplasty in working age patients, hypothesizing that higher occupational hand force requirements lead to higher revision rates. We conducted a follow-up study of patients operated 2003-2015. Self-reported job titles at the time of primary surgery were linked with a job exposure matrix to estimate occupational hand force requirements. Time until revision was analysed using Cox regression. The study comprised 222 patients aged 39-65years (mean 55, SD 6), including 133 patients in the labour market. The median follow-up period was 5years (interquartile range 4-7) and the overall revision rate was 5/100 person-years. For high versus low occupational hand force requirements, the hazard ratio was 1.5 (95% confidence interval 0.5-4.4). For patients outside the labour market, the hazard ratio was 2.3 (0.9-5.6). Our results did not indicate large effects of high occupational hand force requirements on revision rates.Level of evidence: IV.

Early to Mid-Term Results in Trapezio-metacarpal Joint Replacement using the ARPE Implant

Background: Trapezio-Metacarpal Joint (TMJ) arthritis is a common cause of radial sided wrist pain. After conservative measures have been exhausted, the current mainstay of surgical treatment is trapeziectomy. Some surgeons combine this with additional ligament reconstruction and tendon or capsular interposition techniques to provide a more stable base for the thumb metacarpal. Purpose: In modern Orthopaedic practice, arthroplasty is the procedure of choice for many end-stage arthritic joints. However, due to the reliable and reproducible outcomes of trapeziectomy, this has yet to be widely adopted by hand surgeons in the management of TMJ arthritis. Recent series of arthroplasty implants have consistently shown good outcomes and trapezio-metacarpal joint replacement has been observed to provide excellent long-term function in the fit and active patient. Methods: We have performed a total of 52 TMJ arthroplasties in 46 patients in our institution for over 5 years (2011 to 2016). After excluding 3 cases, 43 available patients (49 implants) were subsequently asked to submit QuickDASH scores and a patient satisfaction survey. Results: Average QuickDASH score was 16.6, with high patient satisfaction postoperatively at 1 year. Complications included one intraoperative fracture, and five cases of post-operative instability/ dislocation. Dislocations were treated successfully with open reduction and revision. Conclusion: TMJ arthroplasty has shown good outcomes and patient satisfaction with a low revision rate and we recommend its use in active patients with well-preserved scapho-trapezio-trapezoid (STT) joints.

Total trapeziometacarpal joint arthroplasty using wide awake local anaesthetic no tourniquet

We conducted a descriptive study of 50 consecutive cases of total trapeziometacarpal joint arthroplasty by one surgeon using wide awake local anaesthetic no tourniquet to assess the usefulness and reliability of the anaesthesia, any adverse effects and patient acceptance. No difference was found when comparing the duration of surgery with 50 cases of total trapeziometacarpal joint arthroplasty inserted in a bloodless field under general or regional anaesthesia by the same surgeon. Wide awake local anaesthetic no tourniquet was found to be useful in providing adequate anaesthesia and haemostasis, and to be reliable and safe with no adverse effects. Patient satisfaction was high with 100% willing to repeat. Overall, wide awake local anaesthetic no tourniquet was a satisfactory method of anaesthesia for trapeziometacarpal joint arthroplasty with the potential for significant benefits to both patient and surgeon compared with traditional general anaesthesia and regional block.Level of evidence: II.

Two-year results of the Moovis trapeziometacarpal joint arthroplasty with focus on early complications.

In this prospective study, we aimed to analyse the early results of 200 consecutive total trapeziometacarpal joint arthroplasties using the Moovis cup, a new generation, dual-mobility, uncemented conical cup, with special focus on early complications. At the 24-month follow-up, we found clinically relevant improvement of function and comfort. Among intraoperative complications were nine intraoperative trapezial fractures, which were treated by screw osteosynthesis; prolonged immobilization; and conversion to cemented cup fixation or primary or secondary trapeziectomy. One was left untreated as the loose cup did not cause notable symptoms. There were three implants with polyethylene wear and two with liner dislocation. We conclude that early outcomes of this new-generation implant are favourable, but its surgery is challenging and associated with important intraoperative and early postoperative complications related to the learning curve. Attentive reaming of the trapezium and careful cup impaction are crucial steps to avoid trapezial fracture and early cup failure. Level of evidence: II.

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.

Risk factors for limited improvement after total trapeziometacarpal joint arthroplasty

BackgroundTrapeziometacarpal (TMC) osteoarthritis can be painful and cause disability for patients. Total joint replacement of the TMC joint provides a pseudo arthrosis with good restoration of the thumb motion and pain relief in most patients. But there is also a risk of no improvement following the operation. The purpose of this study was to identify patients at risk of no clinically important improvement following operative treatment of osteoarthritis of the TMC joint.MethodsWe included 287 consecutive patients (225 women, 62 men) treated with total joint replacement of the TMC joint due to osteoarthritis with a mean age of 58.9 years (range 41–80) in a prospective cohort study. We collected information preoperatively and 12 months postoperatively on disabilities of the arm, shoulder and hand score (DASH), grip strength and pain at rest and activity on a visual analogue scale (VAS).Results: We found a statistically significant improvement in DASH from 42.0 to 15.9 (p < 0.001), VAS at rest from 3.5 to 0.6 (p < 0.001), VAS at activity from 7.9 to 2.5 (p < 0.001) and grip strength from 21.6 kg to 27.6 kg (p < 0.001) 12 months after the operation, when analysed as a group. There was an increased risk of no clinically important improvement in hand function for patients with preoperative high preoperative grip strength. Also, we found an increased risk of no clinically important improvement in female patients when using VAS as outcome.ConclusionHowever, we were unable to detect one isolated preoperative predictor as indicator of successful result after operative treatment of TMC osteoarthritis, and as so it was not possible to establish a clinical valid tool for patient selection before surgery.Informed consent was obtained from all patients for being included in the study. The study needed no approval from The Regional Committee of Biomedical Research Ethics as the data was collected, as part of our normal pre- and postoperative clinical pathway, but the study is part of an outcome study of the results after total joint arthroplasty (TJA) of the TMC joint registered in Clinicaltrials.gov (NCT01554748).Trial registrationClinicaltrials.gov (NCT01554748). Registered 15 March 2012.

Complication inhabituelle à 20 ans d’une arthroplastie trapézo-métacarpienne

Trapeziometacarpal joint arthroplasty is a reliable method for treating TM osteoarthritis, with the major benefit of rapid pain relief and recovery after surgery. Despite recent advances in prosthetic design, with a 90% survival rate at 10 years, there remain complication risks that cannot be ignored. The most common complications are prosthetic dislocation and trapezial cup loosening. To our knowledge, flexor tendon rupture has not been reported after TM joint arthroplasty. We report a unique case of total asymptomatic trapeziometacarpal prosthesis dislocation, accidentally discovered after the occurrence of a rupture of the index flexor tendons more than 20 years after surgery in an 82-year-old woman. Formal testing was informative and confirmed the lack of normal function of the superficial and profundus flexor tendons of her left index finger. There was no sign of carpal tunnel compression. She showed satisfactory thumb mobility with a Kapandji score of 8/10 and a grip strength of 10 kg. She had near-comparable mobility to the contralateral healthy side. X-rays showed a total dislocation of the prosthesis stem, whose proximal end was located next to the carpal tunnel. We undertook surgical exploration via a carpal tunnel approach. The prosthesis stem was located at the radial base of the carpal tunnel. Both index flexor tendons were ruptured. The stem was removed and not replaced. The reconstruction of the index profundus flexor tendon was performed by transfer of the ring finger flexor superficialis tendon using the Pulvertaft technique in zone 3. Immobilization was considered unnecessary. Active and passive rehabilitation were performed daily and initiated on postoperative day 1. Follow-up at 6 months showed satisfactory motion of the thumb without any pain, a Kapandji score of 8/10, a grip strength of 12 kg, satisfactory flexion of the index and ring fingers, and a Quick-DASH score of 29.55/100. We noticed a clinical shortening of the thumb explained by significant shortening of M1 on radiographs. This case presents a rare case of complication of trapeziometacarpal joint arthroplasty, since dislocation went unnoticed for a considerable time. Our strategy was to avoid any loss of range of motion. Prosthesis removal was efficient and ring finger superficial flexor tendon transposition allowed immobilization to be avoided. This observation adds a new clinical complication of the trapeziometacarpal prosthesis, and shows an example of how it was promptly managed.

Trapeziometacarpal total joint arthroplasty for osteoarthritis: 199 patients with a minimum of 10 years follow-up.

We report outcomes of 228 consecutive patients with total joint arthroplasty using the Arpe® prosthesis, among which 216 trapeziometacarpal joints in 199 patients had a minimum of 10years follow-up. The cumulative survival rate of the 216 implants at 10years using the Kaplan-Meyer method was 93%. Two hundred joints were functional and painless. We found good integration and positioning of the components in 184 (93%) of the joints. Sixteen prostheses failed. We conclude that this implant has acceptable long-term survival rate and restores good hand function. We also report our methods to improve implant survival and to decrease the risk of component malpositioning, and failure rate. Level of evidence: II.

Trapeziometacarpal Joint Arthroplasty of the Thumb without Osseous Tunnels and Carpal Tunnel Release via a Radial Approach; Technique, and Results.

Background Numerous surgeries have been described for osteoarthritis of the trapeziometacarpal (TMC) joint. We describe the senior author's experience with his technique of concurrent arthroplasty of the TMC joint, and carpal tunnel release (CTR) via a radial approach. Methods The study is a case series of patients managed over a 3-year period. We included 86 patients over 40 years of age that had concurrent CTR. We used the paired t -test to compare the preoperative and postoperative grip strength and functional scoring (including the Levine-Katz questionnaire for carpal tunnel syndrome, disabilities of the arm shoulder and hand [DASH] score and QuickDASH9). Results Mean age at surgery was 62.8 years, and mean follow-up was 13.1 months. Functional outcomes were analyzed in 65 patients. Grip strength returned to the preoperative measurement by 3 months. Analysis of the nine patients followed up for more than 13 months postoperatively showed a significant increase in grip strength at last follow-up. The grip strength in both hands was also similar beyond 13 months. Significant decreases in the functional scores recorded indicated a reduction in disability, symptom severity, and functional impairment. Conclusions In conclusion, we present the favorable results of this technique of TMC arthroplasty and CTR involving no bone tunnels and short-term immobilization.

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

It has been suggested that the cup of a trapeziometacarpal total joint replacement should be positioned parallel with the proximal articular surface of the trapezium to align it with the centre of motion. This would diminish the chance of dislocation. The goal of this study was to test this idea biomechanically. A linked trapeziometacarpal prosthesis was implanted in seven cadaver hands and combined with three-dimensional printed trapezium cups in 17 different orientations. For every combination, stability of the prosthesis was assessed through its entire passive range of motion. Dorsal inclination of the cup relative to the proximal articular surface increased the risk of dislocation with thumb flexion and opposition. The risk of dislocation was also increased with lateral or medial inclination of the cup exceeding 20°. Our results demonstrate that cup orientation is an important factor in prosthetic joint stability. Cup placement parallel to the proximal articular surface is ideal.

Maïa® trapeziometacarpal joint arthroplasty: Survival and clinical outcomes at 5 years’ follow-up

We sought to report the clinical and radiological outcomes and the survival of Maïa® trapeziometacarpal joint arthroplasty retrospectively at a mean 5 years’ follow-up. We evaluated the implant survival and the clinical outcomes of 93 patients (113 prostheses). Patients were examined during a consultation and their mobility, key pinch strength and satisfaction were recorded. Patients also completed a QuickDASH evaluation. The 5-year survival rate was 92.2%. The mean QuickDASH Score was 26.7. The complication rate was 31% and the revision rate was 12.4%. The most common complication was dislocation and the most frequent cause of surgical revision was periprosthetic ossification. We identified two cases of aseptic loosening. This study shows the Maïa® prosthesis provides satisfactory medium-term results and has an excellent 5-year survival. However, the high complication and revision rates are still a major concern.