Emerging Concepts With Post-Lapidus Bunionectomy Weightbearing

Given the increasing literature support for early weightbearing after the Lapidus procedure, this author discusses the evolution of plate fixation to facilitate early weightbearing and reviews key factors in appropriate patient selection.

Some surgeons may consider weightbearing Lapidus itself to be a relatively new concept.1-3 In a 2004 article in Podiatry Today, “Early Weightbearing After Lapidus: Is It Possible?,” I highlighted some basic patient guidelines and pearls on surgical technique from proper joint preparation to screw fixation pearls.2

   A number of studies have emerged, demonstrating that early weightbearing protocols can achieve fusion rates equivalent to or better than strict non-weightbearing protocols.1,4-12 The Lapidus bunionectomy is now considered a weightbearing procedure and it is time to forget the stigma that weightbearing Lapidus always results in non-union.

   What is new, or emerging, are the fixation methods to securely stabilize the fusion to resist the forces of weightbearing during the bone healing phase. Surgeons can achieve successful fusion with a variety of methods but we have yet to determine the best fixation construct for early weightbearing protocols. Specialty plating systems are now commercialized specifically for the Lapidus procedure. Plating has evolved to third-generation systems with specialized design features to match the anatomy and provide a stable construct.

   As a surgeon who has long advocated early weightbearing for the Lapidus procedure, I will share my experiences and how my practice has moved away from screw fixation and progressive weightbearing to specialty plate fixation and more immediate weightbearing (with less extrinsic support from a walking boot or post-op shoe).1-3,13 Prior to plating, I often used three screws (two across the first tarsometatarsal joint and one into the lesser tarsus) to increase the stability to allow for early weightbearing at two weeks. This is the technique we published in our multicenter review of 80 cases.1

   However, the additional screw in the lesser tarsus often becomes an irritant to the intercuneiform area if one did not perform a concomitant fusion to the base of the second metatarsal or the first intercuneiform joint. This additional screw often required removal at a later date. With specialty plating, in my experience, additional fixation is not necessary to achieve a stable fixation construct. Specialty plating has also allowed me to initiate early weightbearing more immediately postoperatively.

   Accordingly, let us take a closer look at third-generation plating for the Lapidus procedure and review the keys to supporting a stable fixation construct.

Should You Plate The Lapidus Bunionectomy?

Successful clinical fusion can occur via isolated screws and/or plates, but the “best” fixation method for early weightbearing has yet to be determined.14,15 Screw fixation was the best option 10 years ago because the plating options simply did not exist.16-25 First, there were “plates” and now there are “plating systems.” Plates have evolved from simple tubular plates to complex engineered plates and screws specifically dedicated for the Lapidus procedure.

   Are there theoretical advantages to plating for the Lapidus? Do these advantages translate into clinical benefits for both surgeon and patient? Do plating systems provide surgeons with confidence in their construct to support postoperative weightbearing and achieve successful clinical fusion?

   The initial experience of surgeons with plates involved simple linear tubular plates that they seemed to use as a bailout when screw fixation failed intraoperatively. These linear plates were not anatomic and required significant bending to make the plates fit better. Often, these plates invaded the naviculocuneiform joint. The advantage of the linear plates was that the surgeon could achieve a long lever arm on the metatarsal component of the fusion but without the cuneiform stability, the cantilever effect did not appear to be effective. Some surgeons recognized this and used concomitant screws to provide this “extra” stability in a belt and suspenders approach.

   Larger T-shaped plates were briefly popular but these plates were developed for distal radius fractures. Accordingly, there is a huge shape mismatch on the medial cuneiform and the plates were prominent and intrusive to the tibialis anterior and the extensor hallucis longus tendon. Additionally, the screw orientation into the medial cuneiform was not ideal.

   The first generation of dedicated Lapidus plating systems offered a four-hole design with two periarticular screws and some with various step-offs within the plate considered that final position of the metatarsal on the cuneiform to achieve a better fit. Locking systems offered more stability. Two theoretical disadvantages of periarticular plating systems are that the cantilever forces are not specifically addressed intrinsically within the plate and compression does not occur.

   The second-generation systems involved more anatomically minded locking plating systems that had a smaller T-shape to increase the fixation options available in the medial cuneiform. The stem of the T provides a longer metatarsal component for a compression hole. Again, some surgeons still utilized a screw that was not incorporated into the plate, mainly because of previous plate generation habits. Another variation is systems that provide a recessed transfixation screw incorporated into the plate. This recessed screw requires one to bore out the undersurface of bone to allow the flat plate to lay against the bone. Flat plates may require bending to match the shape of the fusion site.

A Closer Look At The Third Generation Of Plating Systems

Third-generation Lapidus plating systems include features of previous generations but are designed (contoured) for the special anatomy of the first tarsometatarsal fusion site. In particular, I would like to discuss the Contours Lapidus Plating System (Orthofix).

   There are a few important design features with regard to the shape. First, the plate matches the geographic landscape of the underlying bones. The plate is not flat and is essentially pre-bent. The contour of the plate intrinsically incorporates the final position of the fusion site with the specific consideration that the joint is resected and the metatarsal component either translates inferiorly on the cuneiform or plantarflexes.

   Second, this plate was designed to fit within the safe zone on the medial surface of the fusion site, avoiding the extensor hallucis longus tendon course (superiorly) and the tibialis anterior tendon insertion (inferiorly). Accordingly, there is less chance for soft tissue irritation because the plate does not interfere with mobile structures.

   The design allows for three locking screws on each side of the fusion. The screw angles are oriented to maximize bone purchase. The periarticular screws form a trapezoidal configuration, which resists significant loads. The medial cuneiform surface is maximized for screw options and creates a strong anchor in the proximal fixation block while the long metatarsal component aims to resist the cantilever forces. Compression can also occur with a dedicated tear-shaped compression hole.

   This plate was specifically designed to be a load bearing plate. It was not intended to be a buttress plate. Therefore, there is no need to place an isolated screw (not incorporated into the plate) across the fusion. Since this “extra” screw is not necessary, there is more bone available centrally at the fusion surface. There is a clinical benefit to having the fusion interface devoid of fixation. The fusion site is clearly visible on a medial oblique X-ray view and surgeons can easily assess radiographic healing without obstructing traversing fixation.

Key Considerations For Early Weightbearing

Early Lapidus weightbearing is best defined as “allowing patients to place weight through the operative extremity prior to bony consolidation.” We all know that radiographic fusion typically takes six to eight weeks. What is not clearly defined is: 1) how much weight can one place, 2) the timeframe from surgery to initiating weightbearing or 3) what kind of extrinsic support is needed.

   A proper patient selection and fixation method are probably the most critical factors when determining the viability of a postoperative weightbearing program after Lapidus bunionectomy.1,2 Having a stable fixation construct to resist the weightbearing forces is the first consideration because fixation failure can lead to malunion and/or nonunion.

   Time to start early weightbearing protocol. Some may begin early weightbearing immediately after surgery while others may wait until the soft tissue is healed and sutures are out.1,6 I have tried both approaches. In my early experience with the protocol, I waited two weeks to be sure the soft tissue closed in order to avoid a swelling dehiscence. This is a fine and safe approach. Now, in my practice, most patients are allowed to ambulate immediately and this depends on a variety of patient factors such as skin turgor, general health status and the ability to communicate a possible problem. However, the most important consideration is having a stable construct that can resist the weightbearing loads.

   Type of extrinsic protection. Some form of extrinsic support (i.e., cast, removable walking boot or post-op shoe) is still necessary during the postoperative healing process. A cast provides the most extrinsic support and is the most restrictive. The least support comes from the post-op shoe but allows for significant freedom for the patient. The removable walking boot provides a good balance of support and reassurance for the surgeon that the loads are lighter in comparison to a post-op shoe.

   In all situations, surgeons should be confident that their fixation construct is stable to counteract any early weightbearing for a particular patient. With screw fixation, I tend to use a controlled ankle motion (CAM) walker. With specialty plate fixation, I transition patients to a post-op shoe in most cases.

   Amount of weight allowance. When considering the amount of weightbearing, surgeons initially need to answer two key questions: How stable is the fixation? Will this construct support both the weight and activity demands of the patient?

   The amount of pressure that a patient passes through the foot postoperatively is a gray area. Some advise graduated increases in weightbearing pressure over the course of six weeks. Others allow immediate weightbearing after the patient leaves the operating room. It is reasonable to provide a cane or crutches for assistance, and this is what I do in my practice. Another variation is to have the patients use a cane/crutch assist until the early postoperative discomfort has resolved. In general, most patients seem to avoid much walking for the first two weeks due to the acute nature of the surgery and early post-inflammatory response of healing.

What The Literature Reveals About Early Weightbearing For The Lapidus Procedure

Early weightbearing is not a new concept. Paul Lapidus, MD, allowed weightbearing in a postoperative shoe with a medial plate.25-28 Since fixation options in the 1930s consisted of suturing, the results led to nonunion/malunion. This was mainly because the fusion site did not remain stable. Since the introduction of rigid internal fixation in the late 1980s for Lapidus arthrodesis, there have been numerous studies demonstrating that early weightbearing is an appropriate postoperative protocol.1,4-12 In the four years between 1987 and 1992, there were only four studies regarding early weightbearing.

   It was not until 17 years later when the early weightbearing publications emerged that surgeons became comfortable with the procedure and postoperative protocol, and improved their techniques. Since 1992, seven publications demonstrate a variety of postoperative early weightbearing protocols after the Lapidus procedure with satisfactory results.1,2,6,8,13 While there is literature support for the early weightbearing protocol, proper patient selection is essential.

Emphasizing Proper Patient Selection

There are no exact guidelines that tell you which patients you should allow to bear weight early but there are some well known patient factors that can lead to fixation failure and nonunion. Surgeons should evaluate each patient on a case-by-case basis with regard to the following: age/activity level; overall health status; medical comorbidities; medications; body mass index (BMI); and smoking use.

   Age. This is not a contraindication for early weightbearing. However, you should consider that older or elderly patients may have osteoporosis, which could lead to problems obtaining a strong fixation construct.

   Activity level. Patients should be mindful that the Lapidus procedure is a reconstructive procedure to realign the bones and fusion is required. While solid fixation will keep the bone steady during healing and postoperative weightbearing, it is not a pass to trample or abuse the foot.

   Smoking and non-steroidal anti-inflammatory drugs (NSAIDs). Nicotine is a well known deterrent to fusion. Researchers have also linked anti-inflammatories to delayed bone healing. In these patients, early weightbearing may not increase the risk of failure but it is another variable to contend with and you should be cautious in this subset of patients. Be sure to counsel patients and have them quit nicotine and/or stop NSAIDs.

   Obesity. The heavier the patient, the more weight on the foot and fusion site. Morbid obesity is an absolute contraindication. In heavier patients, it is important to have a strong fixation construct.

   Neuropathy. Without the ability to “feel” the foot, patients with neuropathy cannot gauge just how much weight feels right or identify any emerging internal complications. Accordingly, it is best to avoid this group altogether when considering weightbearing after the Lapidus procedure.

In Summary

With early weightbearing, it is important to have a strong fixation construct. In the community where I practice, patients are highly non-adherent. I have seen patients push early weightbearing protocols and have come to fully appreciate a strong fixation construct. Due to that, my protocols have further advanced to less extrinsic protection and more of a reliance on internal stability. Plating systems have advanced significantly with some being designed specifically for the Lapidus procedure.

   Dr. Blitz is the Chief of Foot Surgery and Associate Chairman of Orthopaedics in the Department of Orthopaedics at the Bronx-Lebanon Hospital Center in Bronx, N.Y.

   The author has disclosed that he is a consultant to Orthofix, Inc., and receives royalties for the Orthofix Contours Lapidus Plating System.

References
1. Blitz NM, Lee T, Williams K, Barkan H, DiDimenico LA. Early weight bearing after modified Lapidus arthodesis: a multicenter review of 80 cases. J Foot Ankle Surg. 2010; 49(4):357-62.
2. Blitz NM. Early weightbearing of the Lapidus: is it possible? Podiatry Today. 2004; 17(8):46-50.
3. Blitz NM. The versatility of the Lapidus arthrodesis. Clin Podiatr Med Surg. 2009; 26(3):427-441.
4. Menke CR, McGlamry MC, Camasta CA. Lapidus arthrodesis with a single lag screw and a locking H-plate. J Foot Ankle Surg. 2011; 50(4):377-82.
5. DeVries JG, Granata JD, Hyer CF. Fixation of first tarsometatarsal arthrodesis: a retrospective comparative cohort of two techniques. Foot Ankle Int. 2011; 32(2):158-62.
6. Basile P, Cook EA, Cook JJ. Immediate weight bearing following modified lapidus arthrodesis. J Foot Ankle Surg. 2010; 49(5):459-64.
7. Kazzaz S, Singh D. Postoperative cast necessity after a Lapidus arthrodesis. Foot Ankle Int. 2009; 30(8):746-51.
8. Sorensen MD, Hyer CF, Berlet GC. Results of Lapidus arthrodesis and locked plating with early weightbearing. Foot Ankle Spec. 2009; 2(5):227-33.
9. Saxena A, Nguyen A, Nelsen E. Lapidus bunionectomy: Early evaluation of crossed lag screws versus locking plate with plantar lag screw. J Foot Ankle Surg. 2009; 48(2):170-9.
10. Sangeorzan B, Hansen S. Modified Lapidus procedure for hallux valgus. Foot Ankle. 1989; 9(6):262-266.
11. Clark HR, Veith RG, Hansen ST Jr. Adolescent bunions treated by the modified Lapidus procedure. Bull Hosp Jt Dis Orthop Inst. 1987; 47(2):109-122.
12. Myerson M, Allon S, McGarvey W. Metatarsocuneiform arthrodesis for management of hallux valgus and metatarsus primus varus. Foot Ankle. 1992; 13(3):107-115.
13. Blitz NM. Early weightbearing of the Lapidus bunionectomy: is it feasible? Clin Podiatr Med Surg. 2012; 29(3):367-381.
14. Klos K, Gueorguiev B, Muckley T, Frober R, Hofmann GO, Schwieger K, Windolf M. Stability of medial locking plate and compression screw versus two crossed screws for Lapidus arthrodesis. Foot Ankle Int. 2010; 31(2):158-63.
15. Klos K, Simons P, Hajduk AS, et al. Plantar versus dorsomedial plate for Lapidus arthrodesis: a biomechanical analysis. Foot Ankle Int. 2011; 32(11):1081-1085.
16. Hansen ST. Functional Reconstruction of the Foot and Ankle. Lippincott Williams & Wilkins, Philadelphia, 2000.
17. Catanzariti AR, Mendicino RW, Lee MS, et al. The modified Lapidus arthrodesis: a retrospective analysis. J Foot Ankle Surg. 1999; 38(5):322-332.
18. Kopp FJ, Patel MM, Levine DS, Deland JT. The modified Lapidus procedure for hallux valgus: a clinical and radiographic analysis. Foot Ankle Int. 2005; 26(11):913-917.
19. Rink-Brüne O. Lapidus arthrodesis for management of hallux valgus--a retrospective review of 106 cases. J Foot Ankle Surg. 2004; 43(5):290-295.
20. Coetzee JC, Wickum D. The Lapidus procedure: a prospective cohort outcome study. Foot Ankle Int. 2004; 25(8):526-531.
21. Popelka S, Vavrík P, Hromádka R, et al. Our results of the Lapidus procedure in patients with hallux valgus deformity. Acta Chir Orthop Traumatol Cech. 2008; 75(4):271-276.
22. Hofbauer MH, Grossman JP. The Lapidus procedure. Clin Podiatr Med Surg. 1996; 13(3):485-496.
23. McInnes BD, Couche RT. Critical evaluation of the modified Lapidus procedure. J Foot Ankle Surg. 2001; 40(2):71-90.
24. Patel S, Ford LA, Hamilton GA, et al. Modified Lapidus arthrodesis: rate of nonunion in 227 cases. J Foot Ankle Surg. 2004; 43(1):37-42.
25. Bednarz PA, Manoli A. Modified Lapidus procedure for the treatment of hypermobile hallux valgus. Foot Ankle Int. 2000; 21(10):816-821.
26. Lapidus PW. Operative correction of the metatarsus varus primus in hallux valgus. Surg, Gynec & Obst. 1934; 58:183-191.
27. Lapidus PW. A quarter century of experience with the operative correction of the metatarsus varus in hallux valgus. Bull Hosp Joint Dis Orthop Inst. 1956; 17(2):404-421.
28. Lapidus PW. The author’s bunion operation from 1931 to 1959. Clin Orthop. 1960; 16:119-135.

   For further reading, see “Why The Lapidus Bunionectomy Is The Best Procedure For Severe Bunions” in the December 2011 issue of Podiatry Today, “Early Weightbearing Of The Lapidus: Is It Possible?” in the August 2004 issue, “Why The Lapidus Procedure Is Ideal For Bunions” in the May 2006 issue or “Current Concepts With The Lapidus Bunionectomy” in the December 2008 issue.