Revision Lapidus Arthrodesis

Sean T. Grambart

Introduction

The Lapidus procedure has been utilized for hallux valgus surgery for over a century. This procedure was initially described by Albricht in 1911 but received its name after Paul Lapidus authored his classic article on his experience with it in 1934.¹^,² However, this procedure did not receive popularity until Dr. Sigvard T. Hansen in Seattle started publishing his experiences with the Lapidus procedure.³ ^–⁵ Dr. Hansen also aided in the popularity of the Lapidus procedure by differentiating the types of joints in the foot: (1) essential, (2) nonessential, and (3) unnecessary. The first tarsometatarsal joint is one of the unnecessary joints in the foot, and surgeons have become more comfortable and willing to perform an arthrodesis of the first tarsometatarsal joint knowing it will not alter the functioning of the foot. The literature was scarce in the 1980s and 1990s, whereas starting in the 2000s, there has been exponential growth in publications. Over time this procedure has become a reliable surgical option for patients with hallux valgus, but evolution continues as the understanding of the deformity and technology continue to expand. To this day there continues to be an advancement and understanding of the indications and techniques for this procedure.

One of the recent paradigm shifts is the concept of frontal plane rotation of the first metatarsal. This is not a new concept as this was first discussed by Mizuno et al in 1956 but has gained momentum in the last decade as studies have demonstrated the significance of pronation of the first metatarsal in relation to hallux valgus.⁶ ^–⁹ Studies have shown that there can be a frontal plane rotation of the first metatarsal with pronation. Although this can be difficult to see clinically on the patient, the frontal plane rotation can be visualized with weight-bearing sesamoid views with standard preoperative radiographs (Figure 7.1). Lack of identification and correction of this eversion of the first metatarsal has been postulated as a reason for incidences of recurrence.

Figure 7.1 Weight-bearing sesamoid axial radiograph showing the pronation rotation of the first metatarsal.

The other evolving paradigm over the last 30 years has come from within the postoperative course from a Lapidus arthrodesis. Traditional postoperative recovery has been non-weight-bearing on the operative lower extremity for a period of 4 to 6 weeks; however, the pendulum appears to be swinging to start weight-bearing by the third week postoperatively. Earlier weight-bearing is progressing owing to advancement with fixation as well as our understanding of the procedure throughout the perioperative period. Extensive review and breakdown of the literature from 1989 to 2019 shows that there were 97 articles written regarding the Lapidus procedure.⁴^,⁵^,¹⁰ ^–¹⁰⁴ Of those 97 articles, 29 discussed postoperative weight-bearing protocol with a total of 2150 Lapidus procedures performed. From 1989 to 1999, studies were published for a total of 138 Lapidus procedures with the overall nonunion rate of 5.7%.⁵^,¹¹^,¹⁸^,¹⁹ Within those studies, 29% of the patients could weight-bear prior to 3 weeks postoperatively. There was a 10% nonunion rate for Lapidus procedures weight bearing prior to 3 weeks postoperatively versus a 4.1% nonunion rate with a more traditional postoperative course.

In the decade of the 2000s, there were 423 Lapidus procedures with an overall nonunion rate of 4.4%.²⁰ ^–²²^,²⁹^,³³^,³⁴^,³⁸^,⁴⁴^,⁴⁸^,⁵¹^,⁵² Seventeen percent of the Lapidus procedures could weight-bear prior to the 3 weeks postoperative point. The early weight-bearing group showed a nonunion rate of 6.9% compared with the 4.8% in the traditional weight-bearing group. Significant change occurred in the decade of the 2010s. There were 20 studies published with a total of 1589 Lapidus procedures that described the weight-bearing protocol.⁵³^,⁵⁴^,⁵⁶ ^–⁵⁸^,⁶⁰^,⁶⁸ ^–⁷⁰^,⁷⁴^,⁷⁶ ^–⁷⁸^,⁸²^,⁸⁴^,⁹²^,¹⁰³ The overall nonunion rate decreased to 4.0%; 40% of the procedures could weight-bear prior to 3 weeks postoperative period. The early weight-bearing postoperative groups nonunion rate dropped to 4.1%, whereas the traditional postoperative weight-bearing group held consistent at 4.0%. These results show that there is a definitive trend heading toward early weight-bearing after Lapidus procedure and maintaining consistent nonunion rates.

Even with these advancements and our continued understanding of the pathology and procedure, complications still occur that require revision surgery. These complications include nonunion with and without deformity, malunion with elevation of the first metatarsal, overshortening of the first metatarsal, recurrent hallux valgus, and overcorrection resulting in a hallux varus deformity.

Indications

The traditional indication for the Lapidus procedure has been a hallux valgus deformity with a large intermetatarsal angle or a hypermobile first ray. However, the primary indication for the procedure is for insufficiency of the first ray. Insufficiency of the first ray is not a clear definition. The author believes that the insufficiency can manifest itself in different ways. The insufficiency can present as instability of the first tarsometatarsal joint with plantar gapping along the joint thus resulting in a forefoot varus (Figure 7.2). This is most common in a pronated foot pediatric or adult flatfoot deformity. The second indication of this procedure is a hypermobile first ray with which there is significantly more motion along the first tarsometatarsal joint but there is no plantar gapping. This can be seen with hallux valgus deformities and a rectus foot (Figure 7.3). Finally, a short first metatarsal or elongated second metatarsal that disrupts the normal tripod of the stable foot is another indication for performing the Lapidus procedure (Figure 7.4). The last 2 indications may manifest the clinical signs as a hallux valgus deformity or second metatarsophalangeal joint pathology since this insufficiency will lead to transfer of weight to the plantar aspect of the second metatarsal head. Clinically this can be seen as a callus formation along the plantar second metatarsal head as well as pain in that area (Figure 7.5).

Figure 7.2 Insufficient first ray with plantar gapping along the first tarsometatarsal joint.

Figure 7.3 A, Clinical hypermobility of the first ray in a hallux valgus deformity. B, Anterior-posterior radiograph of a hypermobile first ray with mild subluxation of the first tarsometatarsal joint. C, Lateral radiograph of the hypermobile first ray without plantar gapping.

Figure 7.4 Anterior-posterior radiograph with elongated second metatarsal with medial deviation of the second toe.

Figure 7.5 Plantar callus sub–second metatarsal head due to insufficiency of the first ray.

Indications to revise a Lapidus arthrodesis include nonunion, overshortening, or elevation of the first metatarsal leading to transfer metatarsalgia and malunion with either recurrence of the hallux valgus deformity or hallux varus (Figure 7.6). Excessive plantarflexion can occur, but this is not nearly as common as the aforementioned other indications. Although these deformities come from the same original arthrodesis site, they need to be evaluated and treated very differently from one another.

Figure 7.6 Clinical view of a recurrent hallux valgus with redness and swelling along the Lapidus arthrodesis site.

Contraindications

Contraindications for an initial Lapidus procedure are very few. Age may play a role when considering a Lapidus procedure. Open growth plates in a pediatric patient with hallux valgus along the proximal first metatarsal is an absolute contraindication. Geriatric patients with hallux valgus may not be able to tolerate any period of non-weight-bearing, and the surgeon may elect to perform different procedures. Degenerative joint disease of the first metatarsophalangeal joint with concurrent hallux valgus deformity would be better suited for correction with a first metatarsophalangeal joint arthrodesis to eliminate both the arthritis as well as the hallux valgus deformity (Figure 7.7). Relative contraindications include nicotine use and vitamin D deficiency, but this appears to be surgeon specific rather than a steadfast rule.

Figure 7.7 Hallux valgus deformity with degenerative changes at the first MTPJ.

Preoperative Considerations

Any revision surgery requires an extensive clinical, radiographic, and laboratory workup to attempt to optimize the best surgical outcome for the patient. Communication between the surgeon, patient, and patient’s family is key, and the surgeon needs to take time to discuss the preoperative workup, surgical procedure, recovery process, and potential complications even more so with the revision surgery compared with the primary surgery.

A careful patient medical and surgical history needs to be performed. Obtaining the medical records and most importantly the surgical records for any previous surgeries is required. The patient should be asked about limitations with activities, shoe wear and pain, and what the goals were for them at the initial surgery and what they are now with the revision. Nicotine use needs to be discussed including the use of any nicotine supplements used for smoking cessation as this can still inhibit healing of the bone. Postoperative course from the previous surgery also needs to be discussed including the amount of time non-weight-bearing as well as patient compliance during the postoperative course. These factors need to be addressed before moving forward with any surgical planning.

In a patient with a nonunion, the surgeon must have a high index of suspicion for a septic nonunion. Clinically, the arthrodesis site needs to be inspected for a possible infective process. Careful clinical evaluation of the arthrodesis site and area around the site should be performed to assess any redness, swelling, and increased warmth (Figure 7.8). Palpation to assess pain at the arthrodesis site as well as any fluctuance should be documented. Weight-bearing examination to visualize the position of the foot and the appearance of the hallux should be carefully assessed.

Figure 7.8 Clinical appearance of a Lapidus with redness and swelling with possible infective process.

Adjacent sites and deforming forces should be extensively examined. Equinus and overpronation of the foot lead to increased stress across the medial column and should be discussed about addressing these deforming forces. Tracking or limited range of motion of the first metatarsophalangeal joint needs to be thoroughly evaluated and addressed at the time of the revision. Scar tissue cannot be overlooked around the arthrodesis site and the first metatarsophalangeal joint since this can make dissection more difficult.

Weight-bearing radiographs of the foot should be obtained to evaluate the arthrodesis site and the positioning of the first metatarsal to evaluate if there is any elevation, plantarflexion, recurrence, or varus deformity. The talar-first metatarsal angle to determine the foot type and apex of the deformity needs to be assessed. In instances of an elevated first ray, the apex of the deformity may be distal to the arthrodesis site and an osteotomy can be considered rather than a takedown arthrodesis.

Radiographically, the arthrodesis site should be evaluated for positioning, fracturing, or loosening of the hardware and the amount of bony callus. If there is minimal bony callus, atrophic nonunion needs to be considered, which may require larger resection of bone versus significant callus formation indicating more of a hypertrophic nonunion showing adequate blood flow to the area. Frontal plane sesamoid axial views can be obtained as well to evaluate for any type of rotational deformity to help with surgical planning.

Computed tomography (CT) scans are often not required for diagnosis of a nonunion but may be more helpful to evaluate malunion deformities as well as degeneration of the first metatarsophalangeal joint. In the case of a nonunion, laboratory studies should be performed including vitamin D levels; complete metabolic panel, including albumin levels; and parathyroid hormone to assess the body’s ability to heal the bone. Complete blood count with differential, erythrocyte sedimentation rate, and C-reactive protein should also be completed to evaluate for possible infective process. Advanced imaging to evaluate for infection with a white blood cell–labeled bone scan or a single-photon emission computerized tomography scan can be performed, but with revision cases with possible infection, bone biopsy and bone and deep wound cultures are recommended for definitive diagnosis. In the presence of an infective process, the nonunion revision will likely need to be staged to resolve the infection first and then proceed with the revision procedure once there is confirmation that the infection has been eradicated.

Preoperative discussion of the “diamond concept” of bone healing in patients with nonunion has been a valuable tool.¹⁰⁵^,¹⁰⁶ The diamond concept was initially described by Giannoudis in 2007.¹⁰⁵ Although this concept was initially described for fracture healing, this can also be extrapolated for primary and revision arthrodesis. The diamond concept is a framework for successful bone repair process (Figure 7.9). The concept incorporates both mechanical stability and the biological environment. Osteogenic mediators include growth factors that stimulate various processes such as vascular endothelial growth factor to promote angiogenesis. Osteogenic cells that contain both osteoprogenitor cells and mesenchymal cells promote proper osseous delineation of cell lines. The extracellular osteoconductive matrix allows for migration of the host and graft cells along the nonunion site. Mechanical stability has been shown to affect cells through electrochemical signals generated by fluid shifts within the canaliculi. Appropriate mechanical stability and osseous apposition will decrease strain across the arthrodesis site and promote osseous incorporation.

Figure 7.9 The diamond concept for bone healing.

Vascularity and host factors were then added to the diamond concept to emphasize how these need to be maximized prior to nonunion revision surgery.¹⁰⁷ Vitamin D levels should ideally be increased if needed and parathyroid hormone checked and adjusted as needed. Bone healing centers are advantageous if they are available. Nicotine use should be stopped and can be checked prior to the surgery with obtaining nicotine levels preoperatively. The use of a Bone Healing Clinic has been valuable preoperatively as well as postoperatively to normalize deficient laboratory levels. In case of surgeons who do not have access to Bone Healing Centers, checking vitamin D levels before the revision can be performed. If the vitamin D levels are low, the author’s typical regimen is 5000 Units of vitamin D and calcium supplementation for 6 weeks followed by repeated laboratory testing. It is important to continue this regimen until the arthrodesis site is healed and then the patient can follow up with the primary care physician for long-term management if indicated. Parathyroid hormone issues are often referred to an endocrinologist. Surgery should be held off if possible until these underlying factors have been resolved.

Preoperatively, the surgeon needs to plan to resect the avascular bone along the nonunion site. Determination of an atrophic versus hypertrophic nonunion will help in surgical planning (Figures 7.10 and 7.11). At times, a significant amount of bone needs to be resected to have vascular bone both proximal and distal to the nonunion site. All these factors need to be considered and planned for prior to the surgery.

Figure 7.11 Hypertrophic Lapidus nonunion.

A relatively defined surgical plan preoperatively is needed to have everything available at the time of surgery. This includes instrumentation to remove the current hardware as well as potentially fractured hardware, orthobiologics or instrumentation for harvesting of autograft, and the instrumentation for the surgeon’s preference on fixation. In the presence of a malunion, the author prefers to use C-arm fluoroscopy in the operating room so that the foot can be properly loaded to make sure the first metatarsal is in proper position both on the anterior-posterior and the lateral radiographs.

Detailed Surgical Description

Nonunion

Nonunion is a frustrating complication for both the surgeon and the patient in that the surgery and the recovery may have been properly performed but the nonunion still occurs. Iatrogenic factors often result in a failure to follow the Glissane principles of arthrodesis: (1) complete resection of the cartilage, (2) accurate and optimal bone contact, (3) optimal position of the arthrodesis site, and (4) maintenance of the bony apposition with stable fixation. The revision surgery must adhere to these principles to maximize a chance at a successful outcome.

Nonunion With No Deformity

Correction of a Lapidus nonunion with good alignment is technically easier compared with a nonunion with deformity (Figures 7.12 –7.14). A linear incision is made along the dorsal medial aspect of the first tarsometatarsal joint through the previous incision. This typically does not have to extend as far distally as the initial procedure. There is often a significant amount of scar tissue along this area, and often the medial dorsal cutaneous nerve is entrapped along this scar tissue. Preoperative discussion about permanent numbness or nerve irritation is needed. Attempt is made to try to preserve the nerve if at all possible but not at the sacrifice of the vascularity of the tissue and bone. Overdissection can often occur, which could lead to stripping of the periosteum, and this can affect the blood flow to the area and needs to be avoided.

Figure 7.12 Preoperative anterior-posterior radiograph with hallux valgus.

Figure 7.13 Anterior-posterior radiograph with nonunion and minimal deformity.

Figure 7.14 Lateral radiograph with nonunion.

The nonunion site will typically contain fibrotic tissue. C-arm intraoperative fluoroscopy can be utilized to help identify the nonunion site. Once the nonunion site is identified, a rongeur is used to remove the fibrotic tissue (Figure 7.15). If a tourniquet is used, the tourniquet is deflated to evaluate vascular supply along the proximal and distal aspects of the nonunion site. Typically, a sagittal saw is needed to resect bone adjacent to the nonunion site. Straight bone cuts need to be made to maintain good alignment of the first ray (Figure 7.16). Bone resection needs to be performed until viable bone is seen both proximal and distal to the nonunion site.