DEFINITION

The Roto-Glide (Implants International, Cleveland, United Kingdom; distributed by Intercus, Bad Blankenburg, Germany) is a noncemented TiCaP surfaced three-component device for total replacement of the first metatarsophalangeal (MTP-1) joint (FIG 1). It allows for normal mobility in the joint.

The metatarsal implant has a rather long intramedullary stem. The upper part of the metatarsal head has an anatomic flange. In the middle, it has a crest which corresponds to the natural crest in the lower part of the head. The phalangeal implant also has a stem. This stem is hollow and has a flat surface toward the metatarsal head. Between the metal pieces, a polymeniscus is inserted. This meniscus has a peg corresponding to the hollow phalangeal implant. The cranial surface of the meniscus is congruent with the metatarsal's surface. It should correspond to the crest for sideboard stability.

Thus, extension/flexion takes place between the meniscus and the metatarsal implant, whereas rotation takes place between the meniscus and the phalangeal implant.

The prosthesis comes with different interchangeable sizes and a set of instruments for precise cutting and drilling.

 

ANATOMY

 

The MTP-1 joint is a true synovial joint. It has a capsule and stabilizing elements such as collateral ligaments and tendon. Involved in the articulation are also the two sesamoids.

 

Functions are dorsiflexion/plantiflexion, abduction/adduction, and rotation.

 

Mobility is foremost dorsiflexion/plantiflexion (80/30) in combination with slight abduction/adduction and rotation that secures an adaption of the great toe to the ground no matter the position of the foot.

 

 

 

FIG 1 • The Roto-Glide is a three-component noncemented device with a mobile bearing.

 

PATHOGENESIS

 

Forces during motion are increasing the more dorsiflexion the joint is loaded in and the forces are applied to the upper half of the metatarsal head and the phalangeal counterpart. These forces lead to degeneration of the cartilage over time that effect primarily the upper aspect of the metatarsal head.

 

The lower part of the metatarsal head, the base of the phalanx, and the sesamoids are less likely affected.

 

NATURAL HISTORY

 

Total replacement of the MTP-1 joint has been in use for about 30 years. It has never reached a standard where it could compete with other treatments such as osteotomy, cheilectomy, arthroplasty, or arthrodesis.3

 

This chapter describes the evolution and suggests a new concept. Before going into the different prosthetic designs that have been tried, one should consider the facts about the anatomy, function, mobility, and forces applied to the MTP-1 joint during loading.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Symptoms of arthrosis of the MTP-1 joint include pain in the joint, especially at the dorsal aspect. This gives pressure problems in shoe wear.

 

 

The other trouble is diminished mobility, especially in dorsiflexion.

 

The contour of the metatarsal head is square. On physical examination, osteophytes can be palpated from lateral, over the dorsal aspect, and to the medial side of the metatarsal head.

 

 

 

There is a painful collision phenomenon in dorsiflexion. The toe is in an anatomic position and the joint is stable.

 

There may also be distinct pain when moving the sesamoids, especially the tibial one.

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

 

Radiographically, arthrosis in MTP-1 joint is graded into four stages, as shown in FIG 2. Pedography

 

Unloading under the MTP-1 joint with decreased contact area and decreased force percentage

 

Lateral shift of the course of the center of gravity, especially during the second half of the gait stance phase

DIFFERENTIAL DIAGNOSIS

Fracture or pseudarthrosis of the sesamoids Gout

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FIG 2 • Grades of arthrosis in the MTP-1 joint. Grade 1, dorsal osteophyte; grade 2, dorsal arthrosis; grade

3, obliterated joint; grade 4, ankylosis.

 

 

 

NONOPERATIVE MANAGEMENT

 

Nonoperative treatment includes stiffening of insole and/or shoe under the MTP-1 joint to decrease the motion of the joint.

 

Pain medication, nonsteroidal anti-inflammatory drugs (NSAIDs), rest, and complete unloading are other options for nonoperative treatment.

 

Physiotherapy has no proven effect.

 

Injections (with corticosteroids) are not recommended due to limited effect and risk of infection.

 

SURGICAL MANAGEMENT

 

Please note that insulin-dependent diabetes mellitus (IDDM) and missing flexor hallucis longus tendon/function are considered as absolute contraindications by the author. Deformities such as hallux valgus are considered as relative contraindications.

 

 

 

FIG 3 • Preoperative radiographs. Dorsoplantar (A) and lateral (B) views with weight bearing showing a hallux rigidus grade 3.

 

Preoperative Planning

 

 

Dorsoplantar and lateral radiographs with weight bearing (FIG 3) Pedography

 

Instruments (FIG 4A) with trial implants (FIG 4B)

 

Positioning

 

 

Supine position with leg elevated (FIG 5) Tourniquet at the thigh

Approach

 

Medial approach with straight incision

 

 

 

 

FIG 4 • Instruments (A) and trial implants (B) used during the procedure.

 

 

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FIG 5 • The patient is positioned supine with the leg elevated.

 

TECHNIQUES

• Exposure and Joint Preparation

The medial joint capsule is incised (TECH FIG 1A).

The entire joint, including the sesamoids, is exposed (TECH FIG 1B).

The flexor hallucis tendon is released but not cut. Synovectomy follows if needed.

 

TECH FIG 1 • A. A straight medial incision is used. B. MTP-1 exposed. C. 1st metatarsal after resection of the medial pseudoexostosis.

Osteophytes at the metatarsal head are removed dorsally, medially, and laterally.

 

 

 

The osteophytes at the base phalanx do not need to be removed because they are cut away (TECH FIG 1C).

 

Osteophytes at the sesamoids should be removed if present.

• Metatarsal and Phalangeal Cuts

   

  The metatarsal jig is applied, taking care it is the normal rotation (TECH FIG 2A).

   

  The angulated cut removes the dorsal osteophyte, and the upper half of the metatarsal head is sliced off at 60 degrees similar to a cheilectomy (TECH FIG 2B).

   

   

   

  TECH FIG 2 • A. Application of the metatarsal jig. B. 1st metatarsal after dorsal and distal osteotomies.

  (continued)

   

   

  Another jig is applied for the cutting of the phalangeal joint surface (TECH FIG 2C). Care must be taken to secure the plantar structures (capsule and the short flexor tendon).

   

  About 2 or 3 mm of the upper phalanx is resected perpendicular to the phalanx axis (TECH FIG 2D).

   

   

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  TECH FIG 2 • (continued) C. Application of the jig for the cutting of the phalangeal joint surface. D. Phalanx and metatarsal after osteotomies.

• Preparation of Intramedullary Canals

   

  Instruments for drill guides to the medullary canals are used (TECH FIG 3).

   

  Care must be taken to ensure the holes are centralized and that the hole in the metatarsal head corresponds to the crest.

   

   

   

  TECH FIG 3 • A. Preparation of metatarsal canal. B. Preparation of phalangeal canal.

• Prosthesis Insertion

   

  Trial prostheses are inserted, and the best fitting meniscus is inserted and checked fluoroscopically (TECH FIG 4A,B).

   

  The joint should be a little slack but not sideboard unstable (TECH FIG 4C,D).

   

   

   

  TECH FIG 4 • A,B. The trial prosthesis is inserted and tested. (continued)

   

   

  The definite prosthesis is coated and the stems are minimally thicker than the trial prosthesis. This allows for press-fit fixation but might hinder the insertion.

   

  If the joint cannot move to 80-degree dorsiflexion, fasciotomy of the flexor muscles is performed.

   

   

  96

   

   

   

  TECH FIG 4 • (continued) C,D. The final prosthesis is inserted.

• Closure

   

   

  The wound is closed in anatomic layers (joint capsule, subcutaneous, skin) following the local standard. A drainage and pain control catheter is inserted (TECH FIG 5).

   

  A dressing is applied. No orthosis or cast is needed.

   

   

   

  TECH FIG 5 • Drain and pain control center inserted.

• Intraoperative Fluoroscopic Imaging

   

  Intraoperative imaging included dorsoplantar (TECH FIG 6A) and lateral (TECH FIG 6B) views and lateral view with dorsiflexion to confirm adequate range of motion and missing dorsal (sub) luxation during dorsiflexion (TECH FIG 6C).

   

  TECH FIG 6 • Intraoperative imaging includes dorsoplantar (A) and lateral (B) views and lateral view with dorsiflexion to confirm adequate range of motion and missing dorsal (sub)luxation during dorsiflexion (C). (Same patient as in FIGS 1, 2, 3, 4, 5.)

   

   

   

   

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  PEARLS AND PITFALLS

   

  Insufficient flexor hallucis longus (tendon) function

  • Leads to weak or missing push-off and might lead to dorsal (sub)luxation. Inspection and reconstruction if necessary could avoid malfunction/(sub)luxation.

 

POSTOPERATIVE CARE

 

Full weight bearing is allowed in cases with normal bone situations, that is, normal or moderately decreased bone density. Partial weight bearing is safer in cases with significantly decreased bone density.

 

 

The same strategy is recommended for postoperative physiotherapy. In stable situations, the postoperative care includes direct toe standing exercises. In less stable situations, motion could be limited until osseous integration at 6 weeks.

 

Radiographs are taken at 6 weeks to confirm osseous integration (FIG 6).

 

The patient is also taught to load on the medial side of the foot over the hallux (the former habit of walking on the lateral side of the foot should be abandoned from day 1).

 

Skin sutures or staples are removed 20 days postoperatively, and the instructions on how to walk correctly are reinstructed.

 

Pedography at 3 months is recommended to confirm adequate loading of the first ray.

 

OUTCOMES

 

Although stemmed silicone prostheses have been rather successful in hand surgery, it led to a significant number of failures in the great toe replacement. The reasons were the greater forces in the MTP-1 joint and the inability for the device to rotate the joint. This gave rise to breakage of the implant at the joint space level, followed by severe synovitis and eventually removal of the implant, leaving severe bone losses.

 

Metal implants have been and are still used either as hemiprosthesis or total prosthesis. The total joints are all two-piece devices. Although uncemented hemiprosthesis may be useful in grades 1 and 2 arthrosis, they have no place in grades 3 and 4 arthrosis. Originally, the two-piece metal devices were cemented. Those with short pegs in the medullary canal loosened. The same has been reported about

the uncemented device.1,4,9 Modern two-piece devices have used metal on polyethylene.

 

 

 

FIG 6 • Postoperative radiograph.

 

 

At 3 years of follow-up, Fuhrmann et al5 found radiographic loosening in 33% of their cases. In a recent study, Bartak et al1 found 16% failures after 24 months, which confirms the results of Kundert and Zollinger-Kies.8

 

Ceramics have no real long-term results, but the results that have been published are not encouraging

 

with shortterm loosening between 12.5% and 18% after 26 months and 3 years, respectively.2,4

In the only attempt of a randomized prospective study, arthrodesis versus total replacement of the MTP-1

joint unfortunately had serious flaws.6 There was change of the procedure in the replacement group from uncemented to cemented implantation because of loosening of the uncemented devices. The authors used the implant for arthrosis stages 1 to 3, and there were bilateral cases and cases that got both arthrodesis on one side and replacement on the other side. Furthermore, the authors claimed that the arthrodesis group got normal loading of the great toe.

This is contradictory to what all others have found, and at the same time, the replacement group did not get any loading on the great toe. Using the knowledge of the biomechanics of the different devices, there would be room for a new device which takes into consideration the failure modes of the current devices. The inventor of the Roto-Glide reported favorable results including improved pedobarographic

patterns.7,10

The author has used this prosthesis for 4 years. At present, about 38 cases have been treated. A prospective review of the series is currently being undertaken. Currently, there has been no aseptic loosening of the prosthesis that it gives excellent pain relief and sufficient mobility for normal daily activities. The author does not recommend running and jumping (for any prosthesis for that matter), but all daily life activities can otherwise be performed.

 

COMPLICATIONS

Stiffness: Revision with arthrolysis and aggressive aftertreatment is recommended.

Insufficient flexor hallucis longus (tendon) function: leads to weak or missing push-off and might lead to dorsal (sub) luxation. Revision, inspection, and reconstruction if necessary could avoid malfunction/(sub)luxation. If reconstruction is not possible, prosthesis removal and fusion are recommended (FIG 7).

Polyethylene component wear/disintegration: Revision with exchange of polyethylene component is recommended.

Loosening: Prosthesis removal and fusion are recommended.

Infection: Prosthesis removal, repetitive débridement, and staged fusion are recommended.

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FIG 7 • Insufficient flexor hallucis longus (tendon) function leads to weak or missing push-off and might lead to dorsal (sub)luxation. Revision, inspection, and reconstruction if necessary could avoid malfunction/(sub)luxation. If reconstruction is not possible, prosthesis removal and fusion are recommended.

A. Intraoperative fluoroscopic image with correct position. B. Postoperative radiograph with dorsal subluxation. C. Intraoperative fluoroscopic image after prosthesis removal and fusion due to nonreconstructible flexor hallucis tendon rupture. The patient desired typical heel elevation of 2 cm, which is simulated intraoperatively to allow for correct positioning of the base phalanx (axis is desired to be parallel to simulated floor with simulated heel elevation).

 

 

 

REFERENCES

1. Bartak V, Popelka S, Hromadka R, et al. Toe-Fit-Plus system for replacement of the first metatarsophalangeal joint. Acta Chir Orthop Traumatol Cech 2010;77(3):222-227.

    

    

2. Barwick TW, Talkhani IS. The Moje total joint arthroplasty for 1st metatarso-phalangeal osteoarthritis: a short-term retrospective study. Foot (Edinb) 2008;18(3):150-155.

    

    

3. Brewster M. Does total joint replacement or arthrodesis of the first metatarsophalangeal joint yield better functional results? A systematic review of the literature. J Foot Ankle Surg 2010;49(6):546-552.

    

    

4. Brewster M, McArthur J, Mauffrey C, et al. Moje first metatarsophalangeal replacement—a case series with functional outcomes using the AOFAS-HMI score. J Foot Ankle Surg 2010;49(1):37-42.

    

    

5. Fuhrmann RA, Wagner A, Anders JO. First metatarsophalangeal joint replacement: the method of choice for end-stage hallux rigidus? Foot Ankle Clin 2003;8(4):711-721.

    

    

6. Gibson JN, Thomson CE. Arthrodesis or total replacement arthroplasty for hallux rigidus: a randomized controlled trial. Foot Ankle Int 2005;26(9):680-690.

    

    

7. Kofoed H. Is total replacement of the first MTP-joint for arthrosis an option? An overview. Fuss Sprungg 2011;9:39-45.

    

    

8. Kundert HP, Zollinger-Kies H. Endoprosthetic replacement of hallux rigidus. Orthopade 2005;34:748-757.

    

    

9. Sinka S, McNamara P, Bhatia M, et al. Survivorship of the bio-action metatarsophalangeal joint arthroplasty for hallux rigidus: 5-year follow-up. Foot Ankle Surg 2010;16(1):25-27.

    

    

10. Wetke E, Zerahn B, Kofoed H. Prospective analysis of a first MTP total joint replacement. Evaluation by bone mineral densitometry, pedobarography, and visual analogue score for pain. Foot Ankle Surg 2012;18(2):1