First metatarsophalangeal joint arthrodesis: a new technique of internal fixation by using memory compression staples

Augmented Fixation in Transverse Midshaft Humerus Fractures Using a Nitinol Staple: Surgical Technique and Case Series

Maintaining the reduction of a transverse humeral shaft fracture can be particularly challenging while applying a compression plate for definitive fixation. Nitinol compression staples are being increasingly utilized in orthopedic surgery due to their unique ability to apply continuous compression between staple legs at body temperature. We have found them to be particularly useful in the maintenance of the reduction of transverse humeral shaft fractures before compression plate application. This simple technique allows for the removal of reduction clamps and precise plate placement. We describe our technique for using nitinol compression staples to augment fracture fixation in transverse humeral shaft fractures as well as our experience using this technique in a case series of 4 patients.

Capitate Fracture Subsequent to Capitolunate Staple Fusion: A Case Report

We report a case of a 71-year-old man who underwent capitolunate fusion for scapholunate advanced collapse. At the patient's 4-month follow-up, there was evidence of a fracture at the distal staple tine. He subsequently underwent removal of staple hardware with revision open reduction internal fixation using headless compression screw fixation and bone grafting. The literature review aimed to identify possible mechanisms and analyze similar cases of this complication. We presume that the fracture resulted from increased stress on the bone from both drill holes and the orientation of the staples. Placing the tines in different planes may decrease the risk of this complication.

Immediate Weightbearing Following First Metatarsal Phalangeal Joint Arthrodesis With 2 Nickel Titanium Alloy Staples

The use of staples has been shown to be a reasonable fixation technique to achieve stability of a first MTPJ arthrodesis. Although it has been shown to be a weaker construct than crossed screws or plate and screw combinations, their ease of insertion, low profile, and stability make them a desirable choice for first MTPJ arthrodesis fixation. However, because of this relative weakness, the question remains whether immediate weightbearing when using staples is advisable. The aim of this study is to determine whether the use of 2 nickel-titanium alloy (NITINOL) staples, placed at 90 degrees to one another is a stable enough construct to support full, immediate weightbearing following first MTPJ arthrodesis. We performed a retrospective chart review of patients undergoing first MTPJ arthrodesis by a single surgeon utilizing 2 NITINOL staples placed at 90 degrees to one another. Patients were allowed to be fully weightbearing immediately postoperatively. Forty-seven of 50 (94%) patients achieved complete radiologic consolidation of fusion at 12 weeks, with only 3 requiring revision surgery for nonunion. All of the patients requiring revision surgery for nonunion, had preoperative diagnosis of hallux abducto valgus. We concluded that the use of 2 NITINOL staples placed at 90 degrees to one another is a viable option for first MTPJ arthrodesis, and immediate weightbearing does not increase rate of nonunion or incidence of revision surgery when compared to other fixation techniques.

Staple Technology for Fracture Fixation and Joint Arthrodesis

The use of staple technology in the upper extremity has continued to evolve with the development of shape-memory alloys (SMAs) such as Nitinol that display superelastic properties that can be exploited for persistent compression. Clinical and biomechanical studies support the use of SMA staples for upper extremity fracture fixation and joint arthrodesis. To optimize biomechanical strength and clinical outcomes, it is recommended to place two staples, if possible, at the site of interest as well as to trough the staples to prevent hardware prominence.

First Tarsometatarsal Joint Fusion in Foot-A Biomechanical Human Anatomical Specimen Analysis with Use of Low-Profile Nitinol Staples Acting as Continuous Compression Implants

Background and Objectives: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit of simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations in comparison to crossed screws and locked plating in a human anatomical model. Materials and Methods: Thirty-two paired human anatomical lower legs were randomized to four groups for TMT-1 treatment via: (1) crossed-screws fixation with two 4.0 mm fully threaded lag screws; (2) plate-and-screw fixation with a 4.0 mm standard fully threaded cortex screw, inserted axially in lag fashion, and a 6-hole TMT-1 Variable-Angle (VA) Fusion Plate 2.4/2.7; (3) CCI fixation with two two-leg staples placed orthogonally to each other; (4) CCI fixation with one two-leg staple and one four-leg staple placed orthogonally to each other. Each specimen was biomechanically tested simulating forefoot weightbearing on the toes and metatarsals. The testing was performed at 35-37 °C under progressively increasing cyclic axial loading until construct failure, accompanied by motion tracking capturing movements in the joints. Results: Combined adduction and dorsiflexion movement of the TMT-1 joint in unloaded foot condition was associated with no significant differences among all pairs of groups (p ≥ 0.128). In contrast, the amplitude of this movement between unloaded and loaded foot conditions within each cycle was significantly bigger for the two CCI fixation techniques compared to both crossed-screws and plate-and-screw techniques (p ≤ 0.041). No significant differences were detected between the two CCI fixation techniques, as well as between the crossed-screws and plate-and-screw techniques (p ≥ 0.493) for this parameter of interest. Furthermore, displacements at the dorsal and plantar aspects of the TMT-1 joint in unloaded foot condition, together with their amplitudes, did not differ significantly among all pairs of groups (p ≥ 0.224). Conclusions: The low-profile superelastic nitinol staples demonstrate comparable biomechanical performance to established crossed-screws and plate-and-screw techniques applied for fusion of the first tarsometatarsal joint.

Retrospective Comparison of Capitolunate Arthrodesis Using Headless Compression Screws Versus Nitinol Memory Staples for SLAC and SNAC Wrist: Radiographic, Functional, and Patient-Reported Outcomes

BACKGROUND

Nitinol memory compression staples have been proposed as an effective alternative to compression screws for capitolunate arthrodesis (CLA) for scaphoid nonunion advanced collapse (SNAC) and scapholunate advanced collapse (SLAC) wrist. The purpose of this study was to compare the clinical outcomes of CLA for SNAC or SLAC wrist treatment using either compression screws or nitinol staples.

METHODS

In all, 47 patients with CLA for SLAC or SNAC wrist with screws or nitinol staples were retrospectively identified. Primary outcome was fusion on radiographs and/or computed tomography. Secondary outcomes were hardware-related complications (HWCs) and other complications, range of motion, grip strength, and patient-reported outcome measures (PROMs), including Visual Analogue Pain scale; Disabilities of the Arm, Shoulder, and Hand score; and patient-rated wrist evaluation.

RESULTS

Of the 47 eligible patients, 40 (85%) were included: 31 patients in the staple group and 9 patients in the screw group. The average age was 49 (17-80) years. There was an 89% union rate for the screw group and a 97% union rate for the staple group. Two patients had screw backout: one who went onto union after screw removal and the other who went onto nonunion after hardware removal. There were 2 (6.5%) HWCs in the staple group. One patient had staple loosening requiring revision and the other dorsal impingement requiring staple removal after radiographic union. In all subsequent cases, the staples were countersunk with no impingement. No significant differences existed between any additional outcomes.

CONCLUSIONS

We found no differences between nitinol staples and screws for CLA regarding HWCs or PROMs. Nitinol staples may offer additional benefits as a safe and effective alternative to compression screws for wrist fusions.

Two Orthogonal Nitinol Staples and Combined Nitinol Staple-Screw Constructs for a First Metatarsophalangeal Joint Arthrodesis: A Biomechanical Cadaver Study

BACKGROUND

End-stage hallux metatarsophalangeal (MTP) joint arthritis is commonly treated with arthrodesis using stainless steel or titanium implants. These implants provide static compression that is maximal at the time of implant insertion. Alternatively, nitinol staples are capable of dynamic compression. They have most frequently been used for midfoot arthrodesis procedures. However, their biomechanical performance during hallux MTP arthrodesis has not been described.

METHODS

8 matched pairs of cadaveric feet (4 female, 4 male) were prepared for hallux MTP arthrodesis using cup and cone reamers. Cadaveric pairs were then instrumented with either (1) a transarticular lag screw and dorsal nitinol staple or (2) orthogonal nitinol staples placed dorsally and medially. Walking in a short leg cast for 6 weeks was simulated by applying 90-N forces at 3 Hz to the plantar proximal phalanx for up to 250 000 cycles. Failure was defined as catastrophic implant failure or plantar gapping beyond 7 mm.

RESULTS

15 of 16 specimens failed cyclic loading. All 8 specimens fixed with orthogonal staples failed at an average of 37 ± 81 cycles. 7 of 8 specimens fixed with a dorsal staple and crossed screw failed at 14 900 ± 39 000 cycles. Collectively, 5 specimens failed because of bone fracture (1 in orthogonal staples, 4 in staple-screw group) and 10 failed because of excessive gap formation (7 in orthogonal staples, 3 in staple-screw group). The number of cycles to failure was significantly lower (P = .0469) in the orthogonal staple constructs compared with the dorsal staple and crossed screw constructs.

CONCLUSION

The tested constructs permit significant motion at the first MTP fusion surface during simulated protected weightbearing. Although multiple in vivo factors should be considered when extrapolating results from this cadaveric study, this motion may result in clinical failure with early postoperative weightbearing protocols.

CLINICAL RELEVANCE

We report the first biomechanical evaluation of hallux MTP arthrodesis using modern nitinol staples in 2 separate constructs.

Application of an arched, Ni-Ti shape-memory connector in repairing distal tibiofibular syndesmosis ligament injury

Objective

To investigate the clinical effect of internal fixation of a Ni–Ti arched shape-memory connector in the treatment of distal tibiofibular syndesmosis ligament injury.

Methods

From January 2013 to January 2016, 108 cases of ankle fracture with distal tibiofibular syndesmosis ligament injury in our hospital were selected, and all of them were fixed with ASCs or screw fixation. The functional evaluation and efficacy evaluation were performed according to the Olerud Molander Ankle Score (Omas) and SF-36. At the same time, follow-ups recorded the incidence of postoperative complications: osteoarthritis, superficial infection, symptomatic hard and soft tissue irritation, early removal and poor reduction of internal fixation, and later loss of reduction.

Results

In the ASC(Ni–Ti Arched shape-memory Connector) group, the incidence of symptomatic hardware, soft tissue or superficial infection decreased to 2.77%(from 13.8% or 11.1% in SCREW group). The early removal rate(2.77%) of internal fixation was also lower than that of the screw group. While the incidence of osteoarthritis is 13.8% in SCREW group, the incidence of osteoarthritis in the later follow-up was also as low as 1.38% in ASC group. Loss of fracture reduction due to removal of the fixation device for the distal tibiofibular syndesmosis ligament was not observed in the ASC group. With two postoperative scoring systems (OMAS and SF-36), patients in the ASC group significantly get higher score than that in SCREW group.

Conclusion

The design of the Ni–Ti arched shape-memory connector can be adapted to the irregular anatomical structure of the malleolus and the ability to continue to contract by body temperature. The use of ASCs in fixation of articular ligaments can preserve a slight range of motion, and the results suggest that ASCs can effectively reduce the incidence of fixation looseness, fracture, infection and other complications.

High Utility of the 1st Metatarsal Phalangeal Joint Fusion

Fusion of the first metatarsophalangeal joint has been used by foot and ankle surgeons as a reproducible and useful means of treating end-stage arthritis of the great toe. However, the overall utility and successful outcomes of this procedure have led to its incorporation into the treatment of more significant bunion deformities, reconstruction forefoot, and salvage procedures. The authors review surgical fixation methods, offer insightful technical pearls for challenging cases and share examples of complex reconstructive and salvage procedures.

Risk Factors for Nonunion After First Metatarsophalangeal Joint Arthrodesis With a Dorsal Locking Plate and Compression Screw Construct: Correction of Hallux Valgus Is Key

First metatarsophalangeal joint (MTPJ) arthrodesis is currently the gold standard technique for advanced hallux rigidus. This retrospective study aimed to identify the risk factors for nonunion after first MTPJ arthrodesis with a dorsal locking plate and compression screw construct. Between April 2014 and April 2019, 165 consecutive patients (28 men and 137 women; mean age, 60 (range, 28-84) years) who underwent 178 primary first MTPJ arthrodeses were retrospectively reviewed. All arthrodeses were performed using either a dorsal locking plate with an integrated compression screw (Anchorage CP plate, Stryker, n = 97) or a dorsal locking plate (Anchorage V2 plate, Stryker, n = 81) with a separate compression screw (4 mm cannulated ACE screw). Union was defined as bone bridging across the fusion site on at least 2 of the 3 standard foot radiographs (anteroposterior, lateral, oblique) and no MTPJ movement or pain during clinical examination. Potential risk factors for nonunion were analyzed with the use of univariate and multivariate analyses. The overall nonunion rate was 6.2% (11 of 178 cases). The risk factors identified in the univariate analysis included preoperative hallux valgus deformity, postoperative residual hallux valgus deformity, and diabetes (p < .05). Multivariate analysis confirmed that postoperative residual hallux valgus deformity (odds ratio 6.5; p= .015) and diabetes (odds ratio 7.4; p = .019) are independent risk factors for nonunion after first MTPJ arthrodesis. Diabetes is the most important independent risk factor for nonunion after first MTPJ arthrodesis with a dorsal locking plate and compression screw construct. A residual postoperative hallux valgus deformity is associated with a significantly increased risk for nonunion. It is therefore crucial to correct the hallux valgus deformity to a hallux valgus angle of less than 20°.

First Metatarsophalangeal Joint Arthrodesis Using Memory Staples: Clinical and Functional Results

Background. We present clinical and functional results of first metatarsophalangeal joint (MTPJ) arthrodesis using Memory staples. Methods. This retrospective observational study reviewed MTPJ arthrodesis with Memory staples from 2012 to 2016. Results. The mean age of 50 patients (55 feet) was 63 years (range 41-77 years). Forty-one feet were in women. Indication was hallux rigidus (n = 49) and hallux valgus (n = 6). The overall union rate was 98.2% (n = 54 of 55), including delayed healing in 3 (5.5%). The average time to union was 12 weeks. At a mean follow-up of 38 months (range 12-73 months), the mean Foot and Ankle Ability Measure score (47 out of 55, 86% response rate) was 87% (interquartile range 78%-100%). Complications included partial laceration of extensor hallucis longus (n = 1), wound infection (n = 4), wound-related (n = 2), lesser metatarsalgia (n = 3), cock up deformity (n = 1), and pain (n = 3). Conclusions. The high union rate, good patient satisfaction scores, and low rate of complications support our use of Memory staples.Levels of Evidence: Therapeutic, Level IV.

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.

Arthrodesis of the first metatarsophalangeal joint: The “when and how”

Arthrodesis of the first metatarsophalangeal (MTP) joint has been established as the “gold standard” for the treatment of several first ray disorders, due to its perceived efficacy and the consistently reported good results in the literature. Arthrodesis is a commonly performed procedure for the treatment of end stage arthritis, rheumatoid arthritis with severe deformity, selected cases of severe hallux valgus (with or without signs of degenerative joint disease), as well as a salvage procedure after failed previous operation of the first ray. The goals of a successful 1^st MTP arthrodesis are pain alleviation and deformity correction in order to restore a comfortable gait pattern and to improve shoe wear. Several techniques have been reported with several proposals regarding the preparation of the articular surfaces and the method of definitive fixation. As with any given surgical procedure, various complications may occur after arthrodesis of the 1^st MTP joint, namely delayed union, nonunion, malunion, irritating hardware, etc.

First Metatarsophalangeal Joint Arthrodesis: A Narrative Review of Fixation Constructs and Their Evolution

First metatarsophalangeal (MTP) joint arthrodesis is a surgical procedure in which the first metatarsal head is fused to the proximal phalanx of the great toe in order to permanently stiffen the first MTP joint. It was originally proposed as a treatment for severe cases of hallux valgus deformity, but the procedure's indications and utilization have expanded since its initial development. Despite a wide variety of indications, first MTP arthrodesis has been shown to have reliable, satisfactory outcomes. As a result, the development of a wide array of surgical approaches, joint preparation techniques, and fixation devices used in the procedure has occurred. In this narrative review, we highlight the evolution of fixation constructs used in first MTP arthrodesis in order to provide a frame of reference for the various types of fixation constructs available.

Does the IOFix implant improve union rates?

BACKGROUND

First metatarso-phalangeal joint fusion is the current gold standard for severe hallux rigidus. Data regarding the union rate and the re-operation rate when IOFix (an Intra-osseous fixation device, Extremity medical, New Jersey, USA) is used for hallux rigidus fusion is limited but promising. The aim of this study was to review our outcomes with the IOFix implant.

METHODS

We have conducted a retrospective chart review, following the approval of the hospital IRB committee. Exclusion criteria included bilateral operations on the same patient, multiple surgeries, charcot foot or other structural foot abnormalities (except hallux valgus), rheumatoid arthritis and a recent foot trauma. We collected demographic data, physical examination documentation, functional score evaluations (AOFAS), and Plain radiographic studies.

RESULTS

Thirty patients were included in the study. The mean age was 60.36 ± 9.12 (range 36 to 77) years, 18 (60%) female patients and 12 (40%) male. Fourteen (53.33%) were left side pathologies. The average follow up period was 36.2 ± 12.31 (range 12 to 54) months. Union was obtained in 28 (93.33%) patients, of whom none had requested a hardware removal due to a prominent hardware during a minimum of 2 year follow up period. The mean postoperative AOFAS score was 80.5 ± 10.87 (range 35 to 90). A more stringent inclusion criteria and fusion definitions would have led to an exclusion of two more patients and a dropout of two patients from the "fused" group, which would have led to a fusion rate of 85.71%.

CONCLUSIONS

This is the largest series of hallux rigidus patients that were operated with an IOFix device. The rates of fusion and hardware removal in MTPJ1 arthrodesis performed with an IOFix implant were found to be similar at most when compared to previously described rates that were obtained with other cheaper and more simple fixation devices.

LEVEL OF EVIDENCE

4.

Minimally invasive arthrodesis of the first metatarsophalangeal joint: A systematic literature review

AIM

Currently, cohort studies reported the use of minimally invasive arthrodesis of the first metatarsophalangeal joint (MTP I). The aim of this systematic literature review was to analyse clinical, radiological outcome and complications with this technique.

METHODS

A systemic literature search of the databases Google Scholar, PubMed, Scopus, EMBASE and Cochrane to identify studies reporting on clinical, radiological outcome or complications of minimally invasive MTP I arthrodesis was conducted.

RESULTS

A total of 6 studies (1 Level V, 5 Level IV) reporting on 109 minimally invasive MTP arthrodesis in 105 patients were included. Validated scores were reported in 103 cases. Clinical outcome improved in 57 cases from a mean of 36.9 to 82.6 points American Orthopedic Foot and Ankle Score (AOFAS) and in 46 cases from 38.7 to 18.4 points Manchester Oxford Foot Questionnaire (MOXFQ). Radiological fusion rate was 87% (n = 94 out of 109) achieved after 6-12 weeks. Overall complication rate was 11.9% (13 cases) leading to revision surgeries in 5.5% (6 cases). Most common complications Most common complications were symptomatic non-union (n = 6, 5.5%), asymptomatic non-union (n = 2, 1.8%) and subsequent interphalangeal joint arthritis (n = 2, 1.8%).

CONCLUSION

Minimally invasive MTP I arthrodesis is a promising technique with comparable clinical, radiological outcome and complication rates to open surgery in hallux rigidus and rigido-valgus. Future studies are needed providing higher level of evidence to prove the potential benefit of minimally invasive compared to open MTP I arthrodesis.

Outcomes of Nitinol Compression Staples in Tarsometatarsal Fusion

BACKGROUND

Tarsometatarsal (TMT) arthrodesis is commonly performed in the management of midfoot arthritis, trauma, or deformity. The purpose of this study was to collect aggregate data (demographic, surgical, and perioperative outcomes) on patients who previously had a TMT fusion with BME compression staples.

METHODS

Sixty-six patients underwent TMT fusion with BME compression staples. Outcomes included demographics, surgical information, the Veterans Rand VR-12 Health Survey, Foot and Ankle Ability Measure (FAAM), visual analog scale (VAS), Revised-Foot Function Index (FFI-R), Ankle Osteoarthritis Scale (AOS), patient satisfaction survey scores, radiographic fusion rate, level of pain reduction, and complications. Sixty-six patients (68 feet) were analyzed (59 females) with an average age of 64 years (range, 18-83). The mean latest follow-up was 35.9 (range, 6-56.6 months).

RESULTS

The average surgical time was 38.1±14.3 minutes (range, 11-75). All outcomes improved significantly (P < .001) from preoperative to latest follow-up except for the VR-12 Mental and Physical score. The average time to fusion determined by radiographs was 8.4 weeks (range, 6.1-46.1 weeks). Wound complications were not seen. Indications for subsequent surgeries (26.5%, 18/68 feet) in this current study included pain (n = 14), broken staples, and nonunion (n = 3).

CONCLUSIONS

The fusion rate in this study, 89.7%, was similar to values reported in the literature. The patient satisfaction score of 81.9 at latest follow-up is consistent with patient satisfaction for other methods of fusion.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Correlations between blood lipid, serum cystatin C, and homocysteine levels in patients with Parkinson's disease

AIM

The aim was too study the correlations between blood lipid, serum cystatin C (Cys C) and homocysteine (Hcy) levels in patients with Parkinson's disease (PD).

METHODS

A total of 322 PD patients and 214 healthy subjects were selected as case and control groups, respectively. The risk factors were explored by logistic regression analysis. The case group was subtyped according to main motor symptoms and age of onset. The correlations of significantly different indices with age, duration of disease, and equivalent dose of levodopa were studied by Spearman's correlation analysis. Receiver operating characteristic curves were plotted to analyze diagnostic values.

RESULTS

Compared to the control group, the PD group had lower serum total cholesterol, triglyceride, and apolipoprotein B (Apo B) levels and higher high-density lipoprotein cholesterol (HDL-C), Hcy, and Cys C levels (P < 0.05). Decreased Apo B level and increased HDL-C and Hcy levels were independent risk factors (P < 0.05). The Cys C level of early-onset patients was lower than of late-onset patients (P < 0.05). Hcy (r = 0.198, P < 0.05) and Cys C (r = 0.281, P < 0.05) levels were positively correlated with age. Triglyceride level was negatively correlated with age (r = -0.202, P < 0.05) and disease duration (r = -0.198, P < 0.05). Unified Parkinson's Disease Rating Scale III score was positively correlated with disease duration (r = 0.435, P < 0.05) and equivalent dose of levodopa (r = 0.423, P < 0.05). The areas under the curve for Apo B, HDL-C, and Hcy levels were 0.341, 0.588, and 0.643, respectively (P < 0.05). The combination of Apo B, HDL-C, and Hcy levels showed high diagnostic value, with a sensitivity of 76.4% and specificity of 69.5%.

CONCLUSIONS

Low serum levels of total cholesterol, triglyceride, and Apo B, and high levels of HDL-C, Hcy, and Cys C may be correlated with PD onset and progression. Decreased Apo B level and elevated HDL-C and Hcy levels are independent risk factors. Early-onset and late-onset PD may have different progression mechanisms.

Nitinol Compression Staples in Foot and Ankle Surgery

Nitinol compression implants are fast and simple to insert and have a high radiographic union rate for midfoot and hindfoot arthrodeses. Applications of nitinol technology in orthopedic surgery are rapidly expanding with the improved and broadened portfolio of implants available.

Biomechanical Properties of Nitinol Staples: Effects of Troughing, Effective Leg Length, and 2-Staple Constructs

PURPOSE

Nitinol memory compression staples are a recent addition to carpal bone fixation. Compared with traditional staples, they have been shown to have superior compression at the far cortex relative to standard and traditional compression staples. The purpose of this study was to (1) determine the effective leg length of different nitinol staples, (2) confirm the effect of 1 versus 2 staples on biomechanical compression, and (3) determine the effect of troughing (countersinking the staple into bone) the bone on staple biomechanical properties.

METHODS

Three commonly used nitinol staples of various bridge and leg lengths were used in a bicortical sawbones block construct. There were 3 separate constructs tested, which included single staple, double staple, and troughed. We measured compression force, stiffness, and bending strength for each construct before and after cyclical 4-point bending. Compression mapping was used to determine the effective leg length of each staple, which included the distance that compression extended beyond the tips of the staple legs.

RESULTS

Effective leg length for each staple construct extended 2 mm distal to the tip of the shortest staple leg. Two staple constructs more than doubled compressive force and increased bending strength by greater than 90% in all staple types. There was no loss of compressive force before or after loading for single, double, or troughed constructs with any staple type.

CONCLUSIONS

This study supports that nitinol staples do not have to be placed bicortically to achieve adequate compression; placing staples 2 mm short of the far cortex has the same compression as bicortical placement; and troughing of the bone will not significantly diminish the biomechanical properties of the construct.

CLINICAL RELEVANCE

Better understanding of the effective leg length of nitinol staples provides support that bicortical placement is not necessary for adequate compression. This study supports troughing bone to minimize implant prominence.

Application of a Ni-Ti arched shape-memory connector in unstable lateral malleolus fractures: A retrospective study

PURPOSE

To compare the outcomes of the arched shape-memory connector (ASC) only fixation and the lateral one-third tubular plate fixation in managing unstable Type A or B lateral malleolus fractures according to the Weber (AO) classification, and to evaluate the feasibility and reliability of ASC only fixation in treating these fractures.

METHODS

From January 2010 to January 2015, 148 patients with Type A or B (Weber (AO) classification) lateral malleolus fractures treated with the arched shape-memory connector (ASC) only fixation or lateral plate fixation were included. There were 66 patients in the ASC only fixation group and 82 patients in the lateral plate group. Intergroup differences were absent regarding patient and fracture characteristics. The incision length, complete-union time, major complications and complaints, incidence of hardware removal, and final radiographic and functional evaluations were compared.

RESULTS

The follow-up time averaged 18.2 months in the ASC fixation group and 17.2 months in the lateral plate group. The ASC only fixation group had significantly decreased wound infection (4.55% versus 14.63%) and skin necrosis (none versus 7.32%). Of patients who underwent ASC only fixation 3.03% reported lateral ankle pain, 7.58% received palpable hardware, and 3.03% reported hardware irritation, while the corresponding observations in the lateral plate group were 19.51%, 54.88%, and 14.63%, respectively, representing a statistical difference. Furthermore, compared with the lateral plate group, the incidence of hardware removal was markedly lower in the ASC fixation group (12.12% versus 30.49%). In terms of reduction accuracy, complete-union time, and AOFAS scores, no appreciable differences were observed.

CONCLUSIONS

ASC only fixation is a reliable alternative for managing Type A or B lateral malleolus fractures, leading to fewer soft tissue complications, fewer hardware complaints, and a reduced need for hardware removal, and a reduced need for hardware removal. In addition, ASC can be used for augmented plate fixation in certain comminuted fracture patterns.

Early Weight-Bearing After Arthrodesis of the First Metatarsal-Phalangeal Joint: A Systematic Review of the Incidence of Non-Union

Arthrodesis of the first metatarsal-phalangeal joint is a reliable procedure for correction of both hallux limitus/rigidus and severe hallux abducto valgus deformities. However, 1 potential contraindication to the procedure is the extended period of non-weight-bearing immobilization that is typically associated with the postoperative course. The objective of this investigation was to perform a systematic review of the incidence of non-union after early weight bearing in patients who underwent arthrodesis of the first metatarsal-phalangeal joint. We performed a review of electronic databases with the inclusion criteria of retrospective case series, retrospective clinical cohort analyses, and prospective clinical trials with n ≥ 15 feet, a mean follow-up of ≥12 months, a defined postoperative early weight-bearing protocol (defined as ≤2 weeks), a clear description of the fixation construct, a reported incidence rate of non-union, and patients who underwent primary surgery for hallux abducto valgus or hallux limitus/rigidus deformities. Seventeen studies met our inclusion criteria, with a total of 898 feet analyzed. Of these, 57 (6.35%) were described as developing a non-union. This would likely be considered an acceptable crude, heterogeneous incidence of non-union when considering this procedure. It might also indicate that arthrodesis of the first metatarsal-phalangeal joint does not always require an extended period of non-weight-bearing postoperative immobilization.

First Metatarsophalangeal Joint Arthrodesis: Does the Addition of a Lag Screw to a Dorsal Locking Plate Influence Union Rate and/or Final Alignment after Fusion

First metatarsophalangeal (MTP-1) joint fusion is a reliable method for the correction of various deformities, including hallux valgus and hallux rigidus. Ideal constructs provide high rates of fusion in the desired alignment. The present study examined the union rates and the change in dorsiflexion angle during the follow-up period in patients who had undergone MTP-1 fusion with a dorsal locking plate and a lag screw compared with patients who had undergone fusion with a dorsal locking plate alone. We performed a retrospective review of 99 feet undergoing MTP-1 fusion. The joints were fused using either a dorsal locking plate alone or a lag screw plus a dorsal locking plate. Union was determined radiographically during the follow-up period. Suspected nonunions were confirmed by computed tomography. The dorsiflexion angles were radiographically measured at the first postoperative visit and at the final follow-up visit. Of the 99 feet, 36 (36.4%) were in the lag screw plus dorsal plate group and 63 (63.6%) in the dorsal plate group. The mean follow-up period was 12.9 (range 12 to 33.5) months. The dorsal plate plus lag screw group had a significantly lower change in the mean dorsiflexion angle (0.57° ± 5.01°) during the postoperative period compared with the dorsal plate group (6.73° ± 7.07°). The addition of a lag screw to a dorsal locking plate for MTP-1 arthrodesis might offer improved stability of the joint in the sagittal plane over time compared with a dorsal plate alone.

First Metatarsophalangeal Joint Fusion With Use of Crossed Kirschner Wires and Intramedullary Steinmann Pin

Primary arthrodesis is a thoroughly studied treatment option for end-stage pathologic entities of the first metatarsophalangeal joint. It is a commonly accepted treatment of many pathologic conditions, including hallux rigidus, severe hallux valgus, hallux varus, and other conditions pertaining to the first ray. Numerous fixation techniques are available for this procedure. Fixation constructs range from simple crossing Kirschner wires to plate and screw fixation or, even, external fixation. We propose a simple and cost-effective fixation technique using an intramedullary Steinmann pin with crossing Kirschner wires. Similar fixation techniques have been described; however, minimal data are available regarding this type of fixation. We present a series of 64 first metatarsophalangeal joint fusion procedures performed on 60 patients using our technique. A retrospective review with attention to several clinical and radiographic parameters was performed. The mean follow-up time was 27 (range 6 to 56) months. This technique resulted in a fusion rate of 90.6% (58 of 64 procedures). Despite the use of a large intramedullary Steinmann pin across the interphalangeal joint (IPJ), only 6 of the 64 procedures (9%) resulted in hallux IPJ degeneration. Of these, only 3 (4.6%) were symptomatic and required therapeutic measures. This suggests that violation of the IPJ with this form of fixation contributes minimally to postoperative pathologic features and is a viable alternative to traditional Association for Osteosynthesis/Association for the Study of Internal Fixation techniques.

Evaluation of different shape-memory staple configurations against crossed screws for first metatarsophalangeal joint arthrodesis: A biomechanical study

BACKGROUND

The first metatarsophalangeal joint may be fused in order to treat arthritis or instability. The use of shape-memory staples for fixation is well recognised, but little work has been done into the optimal configuration of staples.

METHODS

The structural behaviour of first metatarsophalangeal joint (MTPJ) arthrodeses using shape-memory staples or crossed screws was studied using cadaveric porcine joints. Five fixation configurations were tested: single vertical or horizontal staple, paired staples in dorsal-medial configuration (0-90° to the sagittal plane), paired staples in oblique orthogonal configuration (45-135°); or two crossed screws. Specimens were loaded in cyclical dorsiflexion for 1000 cycles. Plantar gapping and shearing were measured. Specimens were then loaded to failure.

RESULTS

Cyclic testing caused more shear in the 45-135° staples than the crossed screws (1.0mm±0.5mm compared to 0.14mm±0.4mm, p<0.01). No significant difference was found in plantar gap formation. Single vertical and horizontal single staples failed at 15N and 19.

CONCLUSIONS

N, respectively. Paired 0-90° staples failed at 43N±9N, significantly lower than the 45-135° staples (141N±25N; p<0.001) and crossed screws (180N±67N; p<0.001). There was no significant difference between the 45-135° staples and crossed screws. Screws failed by sudden cortical fracture; staples displayed gradual pull-out and shearing. First MTPJ arthrodeses fixed with single staples are not recommended. Arthrodeses fixed with staples at 0-90° to the sagittal plane were significantly less strong than two crossed screws. However, positioning oblique staples at 45-135° significantly improved stability, creating a construct as strong as, crossed screws. None of the constructs was strong enough for immediate weight bearing.

Radiographic evaluation of first MTP joint arthrodesis for severe hallux valgus: Does the introduction of a lag screw improve union rates and correction of the intermetatarsal angle?

BACKGROUND

First metatarsophalangeal (MTP-1) joint fusion is a reliable method for the correction of various deformities including hallux valgus and hallux rigidus. Ideal constructs provide high rates of fusion in desired alignment. The present study examines the union rates, as well as the change in dorsiflexion angle during the follow up period in patients who underwent MTP-1 fusion with a dorsal locking plate and a lag screw, versus patients fused with a dorsal locking plate alone.

METHODS

This is a retrospective review of 99 feet undergoing MTP-1 fusion. Joints were fused using either a dorsal locking plate alone or a lag screw plus a dorsal locking plate. Union was determined radiographically during the follow up period. Suspected nonunions were confirmed with CT. Dorsiflexion angles were radiographically measured at first post-operative visit and at final follow up.

RESULTS

There were 36 patients in the lag screw plus dorsal plate group, and 63 in the dorsal plate group. Mean follow up was 12.9 months (Range: 12-33.5 months). The dorsal plate plus lag screw group had a significantly lower change in mean dorsiflexion angle (0.57°±5.01°) during the post-operative period compared to the dorsal plate group at final follow up versus the dorsal plate group (6.73°±7.07°).

CONCLUSION

The addition of a lag screw to a dorsal locking plate for MTP-1 arthrodesis may offer improved stability of the joint in the sagittal plane over time compared to a dorsal plate alone.

LEVEL OF EVIDENCE

Retrospective level III evidence.

Effect of joint pathology, surface preparation and fixation methods on union frequency after first metatarsophalangeal joint arthrodesis: A systematic review of the English literature

BACKGROUND

The aim of this systematic review was to perform a qualitative synthesis of the current literature to determine the union frequencies for first metatarsophalangeal joint arthrodesis as well as the influence of pathology, joint preparation and fixation methods on union.

METHODS

MEDLINE and EMBASE were searched to identify relevant studies reporting on first metatarsophalangeal joint union frequencies.

RESULTS

26 studies with 2059 feet met our inclusion criteria. The mean age was 60 years (range 18-84) and the mean follow-up was 32.6 months (range 1.5-156). The union frequency was 93.5% (1923/2059). The union frequencies were significantly higher when low velocity joint preparation methods were used (P<0.0001, Chi Square 22.5) and the pathology was hallux rigidus (P=0.002, Chi square 9.3). There were similarly high union frequencies with crossed screws, locking plate and non-locking plates.

CONCLUSIONS

High union frequency can be expected following first metatarsophalangeal arthrodesis, especially when low velocity joint preparation methods are used in patients with hallux rigidus.

Biomechanical comparison of pin and nitinol bone staple fixation to pin and tension band wire fixation for the stabilization of canine olecranon osteotomies

OBJECTIVE

To compare the initial biomechanical properties of olecranon osteotomies stabilized with intramedullary pins and a Nitinol bone staple to osteotomies stabilized with pin and tension band wire fixation.

STUDY DESIGN

Ex vivo mechanical evaluation on cadaveric bones.

MATERIAL AND METHODS

Ten pairs of cadaveric forelimbs from skeletally mature Greyhounds with an olecranon osteotomy stabilized with either a pin and Nitinol bone staple or a pin and tension band wire. A single load to failure was applied to each specimen through the triceps tendon. Biomechanical properties were compared based on stiffness, yield load, and maximum load to failure and load at 2 mm of axial displacement.

RESULTS

Specimens stabilized with the bone staple were biomechanically superior in all the variables tested. There was significantly greater stiffness (118.0 ± 25.9 N/mm versus 70.1 ± 40.4 N/mm; p = 0.005), yield load (319.0 ± 99.8 N versus 238.0 ± 42.5 N; p = 0.03), maximum load sustained (385.0 ± 99.2 N versus 287.0 ± 37.4 N; p = 0.009), and load at 2 mm of axial displacement (218.0 ± 51.5 N versus 138.0 ± 48.7 N; p = 0.002) in specimens stabilized with pins and a Nitinol bone staple than specimens stabilized with pin and tension band wire fixation.

CLINICAL SIGNIFICANCE

The pin and Nitinol bone staple construct provides a biomechanically superior alternative to pin and tension band wire fixation for stabilization of olecranon osteotomies, and its use warrants further clinical investigation.

Fusion of the First Metatarsophalangeal Joint and Second to Fifth Metatarsal Head Resection for Rheumatoid Forefoot Deformity

The goals of the present study were to evaluate the mid-term results of first metatarsophalangeal joint fusion combined with second to fifth metatarsal head resection in rheumatoid forefoot deformity and identify the prognostic factors. The inclusion criteria were 2010 American College of Rheumatology and/or European League Against Rheumatism criteria for rheumatoid arthritis; symptomatic forefoot deformity; first metatarsophalangeal joint fusion and second to fifth metatarsal head resection; and a minimum of 4 years of follow-up data available. The patients were evaluated using the Disease Activity Score 28 for rheumatoid arthritis, Health Assessment Questionnaire for Rheumatoid Arthritis, Foot Function Index, forefoot American Orthopaedic Foot and Ankle Society scale, and weightbearing radiographs. Different pre-, intra-, and postoperative variables were investigated to identify the prognostic factors. Sixty-two patients (89 feet) with a mean age of 60.8°± 9.4 years and 85.5°± 22.4 months of follow-up data were included. The preoperative American Orthopaedic Foot and Ankle Society scale score was 33.4 ± 16 points and improved significantly (p < .001) after surgery (mean 82.9 ± 11.7 points). The mean Foot Function Index improved significantly (p < .001) from 131.6 ± 37.4 to 77.4 ± 46.3 points at the last follow-up visit. Only the revision surgery variable was significantly (p = .02) related to poor outcomes. Revision was necessary in 8 feet (9%). This procedure produced satisfactory results. Poor outcomes were significantly related to the necessity for revision surgery for nonunion, malunion, inadequate metatarsal resection, and painful hardware.

Biomechanical evaluation of shape-memory alloy staples for internal fixation-an in vitro study

Background

The field of orthopaedics is a constantly evolving discipline. Despite the historical success of plates, pins and screws in fracture reduction and stabilisation, there is a continuing search for more efficient and improved methods of fracture fixation. The aim of this study was to evaluate shape-memory staples and to compare them to a currently used implant for internal fracture fixation. Multi-plane bending stability and interfragmentary compression were assessed across a simulated osteotomy using single and double-staple fixation and compared to a bridging plate.

Methods

Transverse osteotomies were made in polyurethane blocks (20 × 20 × 120 mm) and repairs were performed with one (n = 6), or two (n = 6) 20 mm nitinol staples, or an eight-hole 2.7 mm quarter-tubular plate (n = 6). A pressure film was placed between fragments to determine contact area and compressive forces before and after loading. Loading consisted of multi-planar four-point bending with an actuator displacement of 3 mm. Gapping between segments was recorded to determine loads corresponding to a 2 mm gap and residual post-load gap.

Results

Staple fixations showed statistically significant higher mean compressive loads and contact areas across the osteotomy compared to plate fixations. Double-staple constructs were superior to single-staple constructs for both parameters (p < 0.001). Double-staple constructs were significantly stiffer and endured significantly larger loads before 2 mm gap formation compared to other constructs in the dorsoventral plane (p < 0.001). However, both staple constructs were significantly less stiff and tolerated considerably lower loads before 2 mm gap formation when compared to plate constructs in the ventrodorsal and right-to-left lateral loading planes. Loading of staple constructs showed significantly reduced permanent gap formation in all planes except ventrodorsally when compared to plate constructs.

Conclusions

Although staple fixations were not as stable as plate fixations in particular loading planes, double-staple constructs demonstrated the most consistent bending stiffness in all planes. Placing two perpendicular staples is suggested instead of single-staples whenever possible, with at least one staple applied on the compression side of the anticipated loading to improve construct stability.

The Impact of Nitinol Staples on the Compressive Forces, Contact Area, and Mechanical Properties in Comparison to a Claw Plate and Crossed Screws for the First Tarsometatarsal Arthrodesis

Background The optimal fixation method for the first tarsometatarsal arthrodesis remains controversial. This study aimed to develop a reproducible first tarsometatarsal testing model to evaluate the biomechanical performance of different reconstruction techniques. Methods Crossed screws or a claw plate were compared with a single or double shape memory alloy staple configuration in 20 Sawbones models. Constructs were mechanically tested in 4-point bending to 1, 2, and 3 mm of plantar displacement. The joint contact force and area were measured at time zero, and following 1 and 2 mm of bending. Peak load, stiffness, and plantar gapping were determined. Results Both staple configurations induced a significantly greater contact force and area across the arthrodesis than the crossed screw and claw plate constructs at all measurements. The staple constructs completely recovered their plantar gapping following each test. The claw plate generated the least contact force and area at the joint interface and had significantly greater plantar gapping than all other constructs. The crossed screw constructs were significantly stiffer and had significantly less plantar gapping than the other constructs, but this gapping was not recoverable. Conclusions Crossed screw fixation provides a rigid arthrodesis with limited compression and contact footprint across the joint. Shape memory alloy staples afford dynamic fixation with sustained compression across the arthrodesis. A rigid polyurethane foam model provides an anatomically relevant comparison for evaluating the interface between different fixation techniques. Clinical Relevance The dynamic nature of shape memory alloy staples offers the potential to permit early weight bearing and could be a useful adjunctive device to impart compression across an arthrodesis of the first tarsometatarsal joint.

LEVELS OF EVIDENCE

Therapeutic, Level V: Bench testing.

Evaluation of Nitinol Staples for the Lapidus Arthrodesis in a Reproducible Biomechanical Model

While the Lapidus procedure is a widely accepted technique for treatment of hallux valgus, the optimal fixation method to maintain joint stability remains controversial. The purpose of this study is to evaluate the biomechanical properties of new shape memory alloy (SMA) staples arranged in different configurations in a repeatable first tarsometatarsal arthrodesis model. Ten sawbones models of the whole foot (n = 5 per group) were reconstructed using a single dorsal staple or two staples in a delta configuration. Each construct was mechanically tested non-destructively in dorsal four-point bending, medial four-point bending, dorsal three-point bending, and plantar cantilever bending with the staples activated at 37°C. The peak load (newton), stiffness (newton per millimeter), and plantar gapping (millimeter) were determined for each test. Pressure sensors were used to measure the contact force and area of the joint footprint in each group. There was a statistically significant increase in peak load in the two staple constructs compared to the single staple constructs for all testing modalities with P values range from 0.016 to 0.000. Stiffness also increased significantly in all tests except dorsal four-point bending. Pressure sensor readings showed a significantly higher contact force at time zero (P = 0.037) and contact area following loading in the two staple constructs (P = 0.045). Both groups completely recovered any plantar gapping following unloading and restored their initial contact footprint. The biomechanical integrity and repeatability of the models was demonstrated with no construct failures due to hardware or model breakdown. SMA staples provide fixation with the ability to dynamically apply and maintain compression across a simulated arthrodesis following a range of loading conditions.

A Short-Term Retrospective of First Metatarsophalangeal Joint Arthrodesis Using a Plate With PocketLock Fixation

BACKGROUND

Various techniques have been described for arthrodesis of the first metatarsophalangeal (MTP) joint. The purpose of this study was to retrospectively review the results of fixation for the first MTP arthrodesis of patients treated using dome-shaped reamers to prepare the joint surfaces and a novel MTP Plate with PocketLock fixation.

METHODS

Between July 2012 and November 2013, 16 feet in 16 patients were treated with a first MTP arthrodesis with a MTP Plate with PocketLock fixation. The mean patient age was 58.8 years (range, 46-82 years). Physical and radiographic examinations were performed at follow-up visits. The average follow-up period was 17.3 months. The radiographs were examined for union (3 bridging cortices), time to union, hardware failure, or other radiographic complications. The charts were reviewed to assess AOFAS-MTP-IP (American Orthopaedic Foot & Ankle Society metatarsophalangeal-interphalangeal) scores and postoperative complications.

RESULTS

Fusion was seen in 11 of 16 feet (68.8%) and partial union in 1 patient (6.3%). Five nonunions (31.2%) were noted in the sample group: All were symptomatic and required revision surgery. No malunions were identified in our sample. One hardware failure was documented in a nonunion patient. The mean time to osseous union was 81.7 ± 15.9 days. The preoperative AOFAS MTP-IP score was 55.6 and the postoperative score was 64.7.

CONCLUSION

The high nonunion and revision surgery rates demonstrate that this particular plate should be used with caution for a first MTP joint arthrodesis.

LEVEL OF EVIDENCE

Therapeutic, Level IV: Case series.

1st metatarsophalangeal joint fusion: A comparison of non-union and gender differences between locking and non-locking plating systems

BACKGROUND

Fusion of the first metatarsophalangeal joint (1st MTPJ) is a common surgical procedure used to treat a variety of diseases and deformities of the forefoot. Fixation methods vary and typically fusion rates are good.

OBJECTIVES

The objectives of the study are to demonstrate whether there is any advantage to using locking as opposed to non-locking plates for 1st MTPJ fusion. Additionally the study aims to determine whether there is any difference in non-union rates according to gender.

METHODS

One hundred and seventy two consecutive 1st MTPJ fusions were performed for 153 patients. 40 patients (23%) were male and 132 (77%) female. Twenty patients received Hallu-fix™ plates, 76 Charlotte™ plates and 76 Anchorage™ plates. Postoperative radiographs were reviewed for non-union. Failure rates were compared using Fisher's exact tests (p=0.05).

RESULTS

Twelve (6.9%) non-unions were identified. The difference in failure rates between all systems was not statistically significant. However, the difference in fusion rates between males (17.5%) and females (3.8%) was significant.

CONCLUSION

This study finds that 1st MTPJ fusion is an effective method to treat diseases of the 1st MTPJ. Locking plates may offer better fusion rates than their non-locking counterparts. This is especially evident in male patients.

Complication rates in diabetics with first metatarsophalangeal joint arthrodesis

BACKGROUND

First metatarsophalangeal joint (MTPJ) arthrodesis has been an effective surgical entity when indicated, but a range of severe to mild complications can occur from this procedure. Patients with diabetes mellitus have an increased risk in surgical complications, most commonly associated with soft tissue and bone healing, when compared to non-diabetic patients. The purpose of this study was to evaluate the complication rates of first MTPJ arthrodesis in diabetic patients and compare them to the existing complication rates for the procedure.

METHODS

A retrospective chart review was done on 76 diabetic patients, from June 2002 to August 2012. Thirty-two males and 44 females were included in the study. The authors evaluated many variables that could impact postoperative complications, including age, gender, bone graft incorporation, hemoglobin A1c, tobacco use, body mass index, peripheral neuropathy, hallux extensus, hallux interphalangeal arthritis, and rheumatoid arthritis, and compared them with the complication findings. Patient follow-up was no less than 24 months.

RESULTS

Overall, approximately two-thirds of the patients had no complications and 35.5% of patients had at least one mild or moderate complication. Of the non-union and mal-union complications, 80 and 70% had peripheral neuropathy, respectively. One hundred percent of the patients that had mal-positions or hardware failure also had peripheral neuropathy. No severe complications were seen during follow-up. Only two of the moderate complications needed revisions, and the rest of those with moderate complications were asymptomatic.

CONCLUSION

In conclusion, first MTPJ arthrodesis is overall an effective and beneficial procedure in patients with diabetes mellitus. Diabetic patients with peripheral neuropathy have an increased risk for mild and moderate complications.

First metatarsophalangeal arthrodesis for hallux valgus

Arthrodesis of the first metatarsophalangeal joint is a reliable operation in the treatment of selected cases of hallux valgus. It corrects deformity of hallux valgus and metatarsus primus varus, leading to good functional results with a low complication rate. It is a technique well suited to patients with hallux valgus associated with degenerative changes or severe deformity, and those for whom primary hallux valgus surgery has failed.

Fixation updates for hallux valgus correction

Fixation options for hallux valgus correction vary. Although some methods are newer and more advanced, even the older techniques are successful in appropriate situations. Kirschner wires and cerclage wiring have their place in proximal phalanx and first metatarsal osteotomies. They are useful for fusion procedures, depending on patient bone quality. Advancements with staple fixation allow the surgeon to apply compression with this device. One of the most stable forms of fixation is the bone screw. By providing a stable construct with good interfragmentary compression, primary bone healing is facilitated. The more recent use of rigid locking plates has allowed for earlier weight bearing following fusion procedures.

Retrospective analysis of the rate and interval to union for joint arthrodesis of the foot and ankle

Arthrodesis is a common procedure indicated for surgical treatment of end-stage degenerative joint disease of the foot and ankle. Many published studies have reviewed the union rate, focusing on specific technique or fixation. However, studies reporting on the average period required to achieve fusion, irrespective of the type of fixation or surgical method used, have been lacking. We report on the union rate and interval to fusion in patients who had undergone primary arthrodesis of various joints of the foot and ankle. A retrospective review of the medical records of 135 patients was performed. The specific joints studied were ankle, and the subtalar, triple, first tarsometatarsal, first metatarsophalangeal, and hallux interphalangeal joints. Our results showed that the average interval for complete fusion was significantly less for the joints in the forefoot, with the subtalar joint, ankle, and triple arthrodesis requiring a longer period to achieve complete fusion. The nonunion rate was also greater when the fusion involved the joints of the rearfoot. Our results have refuted the idea that 6 weeks is the minimum period required to achieve fusion in the foot and ankle. The results of our study support the need for additional education of the patients and surgeons that the interval required for recovery after foot and ankle fusion depends on the location and surface area that has been fused.

Implants for the first metatarsophalangeal joint and prospective considerations

This article reviews the anatomy, pathology and biomechanics of the key joint of the foot, the first metatarsophalangeal joint, before focusing on the various designs of prosthesis that have been proposed for this joint. Metal hemiarthroplasties, single-piece, double-stem silicone implants and multicomponent implants are all considered in detail, as is an assessment of the available clinical results. In addition, preimplantation testing of the implants and the value of explant studies are discussed.

First metatarsophalangeal joint arthrodesis; what is the best fixation option? A critical review of the literature

First metatarsophalangeal joint arthrodesis can be accomplished using many forms of fixation. Distinguishing the best fixation construct requires evaluation of many variables. A review of the literature provides a starting point for what needs to be assessed and what questions need to be asked. In vivo and in vitro studies attempt to provide answers but frequently reveal shortcomings in the evidence to date. In the end, there is always 1 best fixation technique.

Arthrodesis of the first metatarsophalangeal joint: comparison of three techniques

BACKGROUND

There are cadaveric and biomechanical studies comparing different methods of fixation for achieving arthrodesis in hallux rigidus. However, there are no comparative clinical studies. We compared the clinical and radiologic outcomes of first metatarsophalangeal joint fusion using three different techniques: lag screw, lag screw and circlage wire, and Memory staples.

METHODS

This was a retrospective study of 46 patients who underwent first metatarsophalangeal joint fusion. All of the operations were performed by experienced surgeons. Each patient had clinical and radiologic assessments postoperatively.

RESULTS

The three groups were matching in terms of demographic features and comorbidity. Intraobserver and interobserver reliability for radiographic metatarsophalangeal joint fusion was excellent. The mean time to clinical and radiologic union in the Memory staples group was earlier (7.6 weeks) than that of the other two techniques (8.0 and 8.1 weeks). The Memory staples group also had the lowest incidence of nonunion (1 of 15 compared with 4 of 15 in the single lag screw fixation group and 3 of 16 in the lag screw and circlage wire fixation group) and no hardware-related problems.

CONCLUSIONS

Our experience corroborates the advantages of Memory staples as described in the literature, including good approximation of bone fragments, technically easy application with fewer steps than an AO-applied screw, and an adequate source of internal fixation to achieve metatarsophalangeal joint fusion. There is also a suggestion that the time to achieve fusion is shorter.

Incidence of nonunion of first metatarsophalangeal joint arthrodesis for severe hallux valgus using crossed, flexible titanium intramedullary nails and a dorsal static staple with immediate weightbearing in female patients

Myriad forms of fixation have been proposed for arthrodesis of the first metatarsophalangeal joint (MTPJ). Regardless of fixation type, nonunion of the arthrodesis site has been purported as a common complication. The authors performed a retrospective analysis of all patients undergoing arthrodesis of the first MTPJ for severe hallux valgus with 2 crossed, flexible titanium intramedullary nails and a dorsal static 10-mm titanium staple followed by immediate protected weightbearing. Patients were included if they had: surgery for severe hallux valgus of the first MTPJ; undergone the exact internal fixation technique described; not undergone bilateral surgery in the same setting; weightbearing preoperative radiographs; at least 6-week postoperative weightbearing radiographs; initiated weightbearing on the operative foot immediately postoperative in a protective shoe; been followed up clinically for at least 6 months' time postoperatively; and documentation of any complications. One hundred fifty-six female patients (195 feet) with a mean age of 67 ± 9.3 years met the inclusion criteria. Complications due to technical error during insertion of the crossed, flexibe titanium intramedullary nails occurred in 22 (11.3%) feet, but none led to revision surgery. There were 5 (2.6%) asymptomatic nonunions and 1 (0.5%) delayed union, but this ultimately united. The incidence of nonunion after arthrodesis of the first MTPJ using the specific internal fixation construct presented here for severe hallux valgus is lower than the historic mean for most other fixation techniques. However, there is still a need for methodologically sound prospective cohort studies that compare the technique presented here with other modern osteosynthesis techniques.

Nonunion rate of first metatarsal-phalangeal joint arthrodesis for end-stage hallux rigidus with crossed titanium flexible intramedullary nails and dorsal static staple with immediate weight-bearing

Myriad forms of fixation have been proposed for arthrodesis of the first metatarsal-phalangeal joint (MTPJ). Regardless of the fixation type, nonunion of the arthrodesis site has been purported to be a common complication. We performed a retrospective review of all patients undergoing arthrodesis of the first MTPJ for end-stage hallux rigidus with 2 crossed flexible titanium intramedullary nails and a dorsal static 10-mm titanium staple followed by immediate protected weight-bearing. The inclusion criteria were as follows: the exact internal fixation technique described was employed for end-stage hallux rigidus of the first MTPJ only; preoperative and at least 6 weeks of postoperative weight-bearing radiographs were available; weight-bearing was initiated on the operative foot immediately in a protective shoe; the patient was followed for at least 6 months postoperatively; any complication was documented; and bilateral surgery was not done in the same setting. A total of 42 female patients (51 feet) with a mean age ± SD of 69.4 ± 9.2 years met the inclusion criteria. Complications resulting from technical error during insertion of the crossed titanium flexible intramedullary nails occurred in 3 feet (5.9%), but none led to nonunion or revision surgery. One delayed union (2%) occurred but it ultimately united. The incidence of nonunion after arthrodesis of the first MTPJ consisting of 2 crossed flexible titanium intramedullary nails and a dorsal static 10-mm titanium staple for end-stage hallux rigidus in an exclusively female population was lower than the historic mean for most other fixation techniques. However, methodologically sound prospective cohort studies that focus on the use of isolated arthrodesis of the first MTPJ for end-stage hallux rigidus in both male and female patients are still needed, as are comparisons of the presented technique with other modern osteosynthesis techniques.

Arthrodesis of the first metatarsophalangeal joint: a retrospective analysis of plate versus screw fixation

Arthrodesis of the first metatarsophalangeal joint is a commonly accepted technique to treat various afflictions of the hallux. Many techniques have been described to fixate the arthrodesis. However, no superior fixation technique has been identified in regard to nonunion. We performed a retrospective analysis of first metatarsophalangeal joint arthrodeses in our clinic from January 2000 to April 2010, focusing on plate and screw fixation. Our aim was to identify the best fixation construct in regard to fusion rates and radiologic nonunion. We identified 72 arthrodeses performed using 1 oblique (n = 24) or 2 crossed (n = 21) lag screws or a plate (n = 13) or a plate augmented with plantar lag screw fixation (n = 14). Our analysis showed that plate fixation alone results in significantly fewer nonunions than single screw fixation. A comparison of the other fixation types showed no significant differences with regard to nonunion. Although our analysis showed that plate fixation alone is superior to single screw fixation, no definitive conclusion can be drawn owing to methodologic shortcomings. We believe a randomized controlled trial with larger sample sizes is necessary to find the clinically superior fixation technique.

Nonunion after arthrodesis of the first metatarsal-phalangeal joint: a systematic review

Arthrodesis of the first metatarsal-phalangeal joint (MTPJ) has been proposed for treatment of first MTPJ pathology because of the perceived safety and efficacy. Nonunion of the arthrodesis site has been purported as a common complication. The author undertook a systematic review of the electronic databases and other relevant sources to identify material relating to the incidence of nonunion and other complications after arthrodesis of the first MTPJ. In an effort to procure the highest quality studies available, the studies were eligible for inclusion only if they involved patients undergoing arthrodesis of the first MTPJ using modern osteosynthesis techniques (1980 onward time restriction), included a minimum of 30 feet in the publication, and evaluated patients at a mean follow-up of ≥12 months' duration. The studies were also required to include details of any complications requiring surgical intervention, had not primarily involved only rheumatoid arthritis as an indication, and had not involved the use of a structural bone graft. A total of 37 studies involving a total of 2,818 first MTPJ arthrodesis procedures were identified that met the inclusion criteria. The weighted mean age of the patients was 59.3 years, the follow-up was 34.3 months, and the union time was 64.3 days. For those studies that specifically mentioned the indications for first MTPJ arthrodesis, 2,656 joints were included as follows: severe hallux valgus (47.2%), hallux rigidus (32%), rheumatoid arthritis (11.5%), and revision of failed surgery (9.3%). Osteosynthesis involved 3 main configurations: compression screws, dorsal plate and screws, or staples. The overall nonunion incidence was 5.4% (153 of 2,818), with symptomatic nonunion occurring in 32.7% (50 of 153) of all nonunions (1.8% total incidence; 50 of 2,818). The overall incidence of malunion was 6.1% (39 of 640), with dorsal malunion accounting for 87.1% (34 of 39). The overall incidence of hardware removal was 8.5% (69 of 817). The historical comment that nonunion occurs in approximately 10% of attempted first MTPJ arthrodesis procedures is inaccurate. The incidence of malunion and hardware removal is inappropriately high, and efforts to determine effective methods of decreasing their incidence should be undertaken. Additionally, there is still a need for methodologically sound prospective cohort studies focusing on the use of arthrodesis of the first MTPJ for purely severe hallux valgus and specific grades of hallux rigidus, as well as specific forms of osteosynthesis, because this has only been infrequently reported in small series.

First metatarsophalangeal joint arthrodesis: current fixation options

This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available.

First metatarsophalangeal arthrodesis for hallux rigidus

Hallux rigidus leads to a restricted and painful motion at the first metatarsophalangeal (MTP 1) joint. Decision making of the appropriate surgical procedure mainly refers to the stage of hallux rigidus. If conservative measures fail, operative procedures can be taken into consideration. Arthrodesis of the MTP 1 joint is widely accepted as the gold standard for end-stage hallux rigidus. Despite the fusion of a key joint, there is little adverse effect on gait, and weight bearing of the first ray can be restored.