The versatility of the Lapidus arthrodesis

Effect of a compression staple on correction of varus deformity during arthroscopic ankle arthrodesis

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) has become popular because of its higher rate of bone union, lower invasiveness, and shorter hospital stays compared to those of open arthrodesis. However, postoperative malalignment is often observed for severe varus deformity, which can cause nonunion, pain, and adjacent joint arthrosis. A compression staple can provide a persistent, strong compressive force on the bone surface. This study aimed to clarify the difference in alignment correction in AAA by comparing a compression staple and screws fixation with screws-only fixation pre- and postoperatively.

METHODS

Seventy ankles in 67 patients undergoing AAA were retrospectively reviewed. AAA with three screws through the distal tibia was performed in 53 ankles, and 17 ankles underwent AAA with a compression staple and two screws. After the preparation of the joint surface arthroscopically, patients in the S group had three canulated cancellous screws inserted through the medial tibia. Patients in the CS group had a compression staple placed at the lateral aspect of the tibiotalar joint and two screws inserted through the medial side. Clinical scores and pre-and postoperative alignment on plain radiographs were compared between the two procedures.

RESULTS

There were no significant differences in the pre-and postoperative Japanese Society for Surgery of the Foot scale. One ankle in the S group exhibited nonunion. There were no significant differences in talar tilt and tibiotalar angles between the groups. The tibial plafond angle in the CS group was significantly lower than that in the S group (p < 0.05). Postoperatively, talar tilt and tibiotalar angles on the coronal image, and the lateral tibiotalar angle in the CS group were significantly lower than those in the S group (p < 0.05).

CONCLUSION

AAA with a compression staple and two-screw fixations could obtain more optimal alignments than AAA with screw-only fixation, even in cases with severe varus deformity.

The Application of Morton's Observations to Contemporary Treatment of Foot Dysfunction

Understanding the evolution of the human foot from a flexible grasping structure to one that is designed for upright posture and locomotion is paramount to treating patients with foot pain and dysfunction. Almost 100 years ago, Dudley Morton observed that certain retained atavistic traits are responsible for pathologic breakdown of the modern foot. Cadaveric research under the direction of Jeffrey Christensen provided evidence that lengthening the gastrocnemius and stabilizing the medial column helped correct the faulty biomechanics associated with Morton foot and corroborated Hansen's blueprint for reconstructive surgery of the foot and ankle.

Assessing the biomechanical properties of nitinol staples in normal, osteopenic and osteoporotic bone models: A finite element analysis

OBJECTIVE

Bone staples are internal fixation devices that are frequently used in the foot, ankle, and hand to provide stabilization. Fixation stability is vital after fusion or fracture surgeries to ensure proper bone healing. Patients undergoing surgeries that require fixation to keep bones aligned and stable may present with diminishing bone mechanical properties, and this may compromise the ability of the fixation hardware to maintain a stable construct. The purpose of this study was to investigate the mechanical performance of shape memory and superelastic nitinol bone staples with different bridge geometries in normal, osteopenic, and osteoporotic bone models. Contact forces and maximum principal stress and strain in the bone were recorded.

METHODS

Finite element simulations of a bone staple fixation procedure were performed to examine the initial and post-surgery contact force, as well as the maximum principal stress and strain of 15 mm bridge and 20 mm bridge staple-bone constructs.

RESULTS

Shape memory nitinol staples exhibited higher contact forces compared to superelastic nitinol staples. Nitinol bone staples with 20 mm bridge lengths displayed higher contact forces and lower stresses in all bone types, as well as lower strains in osteoporotic bone models compared to nitinol staples with a 15 mm bridge length.

CONCLUSION

Nitinol bone staple constructs with 20 mm bridge length staples provide higher contact forces and display lower stresses in the bone than 15 mm bridge staple-bone constructs, which may be beneficial in bone with diminishing mechanical properties. Both superelastic and shape memory effect nitinol staples provide adequate compression and stress relief. However, if osteopenia is present, shape memory effect nitinol staples with a 20 mm bridge length may provide more stress relief and compression, if the bone anatomy allows.

Recurrence of Hallux Valgus After Modified Lapidus Procedure With Successful Fusion of the Intermetatarsal and Intercuneiform Joints

Background

The Lapidus procedure has become a popular procedure in correcting hallux valgus deformities and has undergone several modifications in an effort to improve the efficacy of the procedure. The senior author modifies this procedure with the addition of an intermetatarsal and intercuneiform fusion. Our hypothesis is that this will improve the procedure outcomes and decrease deformity recurrence.

Methods

We reviewed patient charts who underwent the procedure between 2014 and 2017 performed by the senior author. This yielded 47 reviewable cases, with 34 meeting study criteria. The cases were analyzed for standard hallux valgus measurements (intermetatarsal angle [IMA], hallux valgus angle [HVA]) and fusion on X-ray.

Results

The results of the study showed partial intermetatarsal and intercuneiform fusion failure in seven (20%) cases, and one case where the great toe fell into varus. These cases were excluded. In the remaining cases, there was a statistically significant improvement in the HVA and IMA between the preoperative X-ray and first postoperative X-ray. Additionally, there was no significant difference between HVA and IMA between first and final postoperative radiographs. There was a significant increase in IMA for the fusion failure cases (p=0.001).

Conclusion

Clinically, our findings demonstrate that successful union is possible with low recurrence and complication rates when using this modification of the Lapidus procedure in patients with hallux valgus deformity.

Structures at Risk From an Intermetatarsal Screw for Lapidus Bunionectomy: A Cadaveric Study

The Lapidus bunionectomy is performed to treat hallux valgus. Recurrence of the deformity remains a concern. A transverse intermetatarsal screw spanning the base of the first metatarsal to the base of the second can increase stability. The neurovascular bundle is located within the proximity of this screw. In this study, we assessed the structures at risks with the use of this technique. In 10 specimens, a guide wire was placed, and a 4.0-mm cannulated screw was inserted. The neurovascular bundle was dissected and inspected for direct trauma to the neurovascular bundle, and the proximity of the screw was measured using a digital caliper. Ten cadaveric specimens were used. The dorsalis pedis artery and deep peroneal nerve were free from injury in 9 of 10 specimens. In those 9 specimens, the neurovascular bundle was located dorsal in relation to the screw. The mean distance of the screw to the neurovascular bundle was 7.1 ± 3.3 mm. The mean distance from the screw to the first tarsometatarsal joint (TMTJ) was 14.7 ± 4.3 mm. The mean distance from the screw as it entered the second metatarsal to the second TMTJ was 18.0 ± 7.2 mm. In 1 specimen, the screw was found to be traversing through the neurovascular bundle. The distance from the screw to the first TMTJ was 15.0 mm. The distance of the screw from where it entered the second metatarsal to the second TMTJ was 24.0 mm. Although the intermetatarsal screw avoided the neurovascular cases in most instances, there is some anatomic risk to the neurovascular bundle. Further study is warranted to evaluate clinical results using the intermetatarsal screw for the modified Lapidus procedure.

Revision Lapidus Arthrodesis by Bone Endoscopy

Revision arthrodesis is indicated in symptomatic nonunion of the first tarsometatarsal joint. Revision by first tarsometatarsal arthroscopy cannot deal with the dilated screw tract and associated bone cysts. Revision by bone endoscopy is indicated in symptomatic nonunion of the first tarsometatarsal joint, which is previously fixed by transarticular screw along with loosening of the screw and bone cyst formation. The screw tract makes up the portal tract, with the proximal and distal ends of the tract corresponding to the proximal and distal portals, respectively. In this technical note, we describe zonal debridement and bone grafting of the bone cysts, nonunion site, and the screw tract via the bone endoscopy. This can resolve all the co-pathologies of nonunion of the first tarsometatarsal fusion.

Isometric Scaling in Developing Long Bones Is Achieved by an Optimal Epiphyseal Growth Balance

One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Although organ scaling is fundamental for development and function, little is known about the mechanisms that regulate it. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation and, therefore, their position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations. Here, we document the process of longitudinal scaling in developing mouse long bones and uncover the mechanism that regulates it. To that end, we performed a computational analysis of hundreds of three-dimensional micro-CT images, using a newly developed method for recovering the morphogenetic sequence of developing bones. Strikingly, analysis revealed that the relative position of all superstructures along the bone is highly preserved during more than a 5-fold increase in length, indicating isometric scaling. It has been suggested that during development, bone superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. Surprisingly, our results showed that most superstructures did not drift at all. Instead, we identified a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between proximal and distal growth rates, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process. Our study reveals a general mechanism for the scaling of developing bones. More broadly, these findings suggest an evolutionary mechanism that facilitates variability in bone morphology by controlling the activity of individual epiphyseal plates.

A novel computational approach for studying bone morphogenesis reveals that the longitudinal proportions of developing long bones are accurately maintained throughout elongation by the balance between proximal and distal growth rates.

One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation. Therefore, superstructure position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations.

Here, by analyzing a massive database of micro-CT images of developing mouse long bones, we show that all superstructures maintain their relative positions throughout development. It has been suggested that during development, superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. However, our analysis reveals that most superstructures did not drift at all, implying the involvement of another mechanism. Indeed, we identify a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between the growth rates from its two ends, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process.

Modified lapidus arthrodesis with crossed screw fixation: early weightbearing in 136 patients

Modified Lapidus arthrodesis is a versatile and powerful procedure for correcting the hallux valgus deformity typically associated with significant metatarsus primus varus or increased first ray mobility. Traditionally, patients have remained non-weightbearing until the arthrodesis has consolidated. More recently, numerous studies have evaluated the outcomes of early postoperative weightbearing using a variety of fixation constructs. The present retrospective cohort study evaluated 136 consecutive patients who had undergone modified Lapidus arthrodesis for hallux valgus deformity with conventional, crossed, solid core, screw fixation, were enrolled in an early weightbearing protocol, and were followed for 12 months. All the patients were partial weightbearing in a protective boot a mean of 12.2 (SD ± 4.36) days after surgery, with full weightbearing at 34.4 (SD ± 11.89) days. Union was achieved in 133 patients (97.8%). Of the 3 (2.2%) patients with nonunion, 2 (1.5%) remained asymptomatic. The mean time to radiographic union was 65 (SD ± 37.24) days. Significant improvement was seen in the first intermetatarsal angle and hallux abductus angle after surgery (p < .0001). Deformity correction was not compromised by early weightbearing and was well maintained over time. These results support early weightbearing with traditional crossed screw fixation for modified Lapidus arthrodesis with outcomes and complication rates comparable to those previously published.

Contemporary approaches and advancements to the Lapidus procedure

The Lapidus procedure as evolved over the last 50 years. What originally was a difficult procedure with poor outcomes has changed to a procedure that allows for ideal realignment of the deformity at its source, improved foot alignment, and minimal to no need for further surgery. The authors now use a weight bearing plate which has improved overall patient care, with a minimized risk of nonunions, and more rapid return to early weight bearing and range of motion. This method has opened up the procedure to more patients, decreased the recovery time, and allowed for early physical therapy, resulting in outstanding patient outcomes.

End-stage osteoarthritis of the great toe/hallux rigidus: a review of the alternatives to arthrodesis: implant versus osteotomies and arthroplasty techniques

Hallux rigidus is defined as end-staged arthrosis of the first metatarsophalangeal joint. Although the literature supports arthrodesis as being the gold standard for the treatment of end-staged hallux rigidus, there are several other treatments available that can either prolong the life of the remaining joint or artificially mimic the original biomechanics by replacing a portion of or the entire joint with the added advantage of preserving joint mobility. There are several new and emerging joint preservative techniques that may delay or prevent the need for a joint-destructive procedure, such as arthrodesis or arthroplasty.

Symptomatic first metatarsocuneiform nonunion revised by arthroscopic lapidus arthrodesis

Lapidus arthrodesis is indicated for painful, advanced hallux valgus and symptomatic first ray hypermobility with or without arthrosis of the joint. Nonunion of the first metatarsocuneiform joint fusion is the most frequent complication of attempted lapidus arthrodesis. We present a case of painful first metatarsocuneiform nonunion that was successfully treated using arthroscopic revision lapidus arthrodesis to describe this unusual approach to a known postoperative complication.

Early weightbearing of the Lapidus bunionectomy: is it feasible?

The Lapidus procedure should no longer be considered a strict nonweightbearing bunionectomy. In the past few years, several studies have emerged demonstrating that early weightbearing after a Lapidus fusion is indeed possible with satisfactory fusion rates. This is mainly because of improved fixation techniques available today, which have allowed for better stabilization of the fusion site. Surgeons should still properly indicate patients for early weightbearing protocols.

The use of the Lapidus procedure for recurrent hallux valgus

BACKGROUND

The objective of this study was to evaluate the Lapidus procedure or it's modifications for treatment of recurrent hallux valgus (HV). Our hypothesis was that the Lapidus procedure would achieve good correction of recurrent HV and patients would be satisfied.

MATERIALS AND METHODS

A retrospective review of 32 feet (30 patients) treated with the Lapidus procedure for recurrent HV with at least 1-year followup was performed. Evaluation included radiographs, examination, and chart review. Outcomes were assessed with a pain visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) hallux score, SF-12, Revised Foot Function Index (RFFI), and a survey. Twenty-three of 30 patients (25 feet) met the criteria for inclusion in the study and were available for followup evaluation. The average followup was 31.6 months.

RESULTS

Arthrodesis was present in 24 out of 25 feet (96%). The time from initial HV correction to revision surgery was 91 months. The initial surgery performed was a distal osteotomy (15), proximal osteotomy (five), exostectomy (two), diaphyseal osteotomy (two), and proximal/distal osteotomy (one). Preoperative evaluation revealed 96% of patients had clinical hypermobility of the first TMT joint and 52% had radiographic findings of instability. The average postoperative AOFAS hallux score was 82.8, SF-12 score was 94.5, and RFFI was 101. The average preoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) were 36.2, 13.6, 18.6 degrees, respectively, which corrected to an average of 15.2, 7.5, 11.7 degrees postoperatively (p < 0.001). The average shortening of the first ray was 2.9 mm. Average pain VAS was 2.4. Eighty-seven percent reported good to excellent results. Using a multivariable linear regression analysis, postoperative HVA along with change in length of the first ray were significant predictors of quality of life based on SF-12 (p < 0.05).

CONCLUSION

The Lapidus procedure corrected recurrent HV with a low nonunion rate and excellent radiographic correction and patients were satisfied with their outcome.

LEVEL OF EVIDENCE

IV, Retrospective Case Series

The unreliability of the intermetatarsal angle in choosing a hallux abducto valgus surgical procedure

Conventional thinking holds that high intermetatarsal and hallux abductus angles (>15° and >25°, respectively) are associated with a hypermobile first ray and require a Lapidus procedure to achieve satisfactory correction for the treatment of hallux valgus. However, normal first ray motion may be misinterpreted as hypermobility, and it is possible to take advantage of this motion to correct some portion of a large hallux abductovalgus deformity with distal procedures, such as the Austin or first metatarsophalangeal joint fusion. We retrospectively examined radiographs of 61 patients with first intermetatarsal and hallux abductus angles greater than 15° and greater than 25°, respectively, who had undergone hallux abductovalgus correction via Lapidus, Austin, or first metatarsophalangeal joint fusion. Preoperative and postoperative radiographic measurements of the intermetatarsal and hallux abductus angles were made. The results revealed no statistically significant differences in the amount of correction achieved by any of the 3 procedures in comparison with the others. We concluded that, given appropriate patient selection, an Austin or first MTPJ fusion could reliably correct large intermetatarsal and hallux abductus angles that, in the hands of many surgeons, are often treated by means of Lapidus arthrodesis.

Fixation of first tarsometatarsal arthrodesis: a retrospective comparative cohort of two techniques

BACKGROUND

Presently, indications for the Lapidus procedure include patients with many pathologies of the first metatarsocuneiform joint. Currently the standard in many areas is that of two or three crossed screws through the first tarsometatarsal region. This type of fixation requires an extended period of nonweightbearing and may be difficult for patient compliance.

MATERIALS AND METHODS

The present study is a retrospective comparison of crossed screw fixation to locking plate fixation without a lag screw on union rates, time to weightbearing, and complications.

RESULTS

One hundred forty-three first TMT fusions met the inclusion criteria. There were 96 fused by crossed screw construct (CS) and 47 by the locked plate with or without compression screw (LP). There was a significant difference in time to full weightbearing and union rate. Time to full weightbearing was 8.8 (range, 3 to 16) weeks and 7.8 (range, 1.5 to 34) weeks in the CS and LP groups, respectively (p < 0.001). Union rate was 89.4% (88 of 96 joints) and 98.5% (46 of 47 joints) in the CS and LP groups, respectively (p < 0.001).

CONCLUSIONS

We found that when using a dorsal-medial locked plate with or without lag screw lead to a superior rate of union compared to standard crossed screw constructs even while allowing earlier return to full weightbearing.