Biomechanical Comparison of a Locking Plate with Intraplate Compression Screw Versus Locking Plate with Plantar Interfragmentary Screw for Lapidus Arthrodesis: A Cadaveric Study

Lapidus arthrodesis (first metatarsal cuneiform arthrodesis) has become an accepted procedure for hallux abducto valgus. Several variations of fixation have been described. Earlier weightbearing postoperatively has been one reported benefit of using locking plates for fixation. Additionally, studies have demonstrated that fixation placed on the plantar or tension side of the arthrodesis increases the biomechanical advantage. We performed a biomechanical cadaveric study of the Lapidus procedure, comparing a previously reported technique using a low profile locking plate with an intraplate compression screw versus the same locking plate with a plantar interfragmentary screw (PIFS) placed on the tension side of the arthrodesis in 10 fresh, paired, cadaver limbs. The mean ultimate load of the plate with a PIFS was 383.2 ± 211.5 N, and the mean ultimate load of the plate with an intraplate compression screw was 205.5 ± 97.2 N. The mean ultimate load of the LPS Lapidus plate with a PIFS was statistically greater (p = .027) than that with the plate intraplate compression screw. Our results indicated that changing the orientation of the compression screw to a PIFS significantly increased the stability of the Lapidus arthrodesis fixation construct. The modified construct with the PIFS might decrease the incidence of nonunion and, ultimately, allow patients to bear weight faster postoperatively.     

Medial Locking Plate Versus Screw Fixation for Fixation of the Ludloff Osteotomy

A prospective cohort study of the Ludloff osteotomy, stabilized with either lag screws or a locking plate, was undertaken from May 2001 to November 2010, involving patients treated for hallux valgus with a first intermetatarsal angle greater than 15°. All patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) and Roles and Maudsley scores before and after surgery. The cohort included 119 procedures in 112 patients, 91 (76.47%) of which were fixated with lag screws and 28 (23.53%) with locking plates. The participants were categorized as active (n = 69 procedures) or athletic (n = 50 procedures). The overall mean patient age was 45.5 ± 14.2 years. No statistically significant differences were found between the fixation groups relative to age, preoperative AOFAS and Roles and Maudsley scores, and postoperative AOFAS scores. Postoperatively, the mean Roles and Maudsley score for the lag screw group was 1.8 ± 0.6 and that for the locking plate group was 2.2 ± 0.7 (p < .009). In both groups, the AOFAS scores improved significantly (p < .0001) after surgery. The mean interval to return to activity in the athletes was 3.6 ± 1.1 months and was 3.9 ± 1.2 weeks in the active group (p = .16). Also, 4 of the active patients (5.8%) failed to return to their desired activity level. Overall, 6 (5%) recurrent hallux valgus deformities were observed, 5 (4.2%) in the lag screw group and 1 (.8%) in the locking plate group (p = .57). Of the 6 recurrences, 5 occurred (4.2%) in patients older than 50 years (p = .05).     

Immediate Weightbearing After First Metatarsophalangeal Joint Arthrodesis With Screw and Locking Plate Fixation: A Short-Term Review

Historically, the postoperative protocol for patients undergoing first metatarsophalangeal joint arthrodesis has included 6 weeks of non-weightbearing, followed by protected weightbearing in a below-the-knee cast boot or postoperative shoe. This prolonged period of non-weightbearing predisposes the patient to disuse atrophy, osteopenia, deep vein thrombosis risk, and, overall, a prolonged time to recovery. The present study reports a retrospective review of a patient cohort that underwent first metatarsophalangeal joint fusion with immediate full weightbearing postoperatively. Thirty consecutive first metatarsophalangeal joint arthrodeses were performed during the study period. Five patients were excluded secondary to insufficient postoperative follow-up data or a lack of adequate radiographic evaluation at regular postoperative intervals. Conical reamers were used for joint preparation. Internal fixation, consisting of a single cannulated interfragmentary compression screw and a dorsal locking plate, was used in all patients. The results showed that patients achieved clinical healing at an average of 5.92 weeks and showed radiographic fusion at an average of 6.83 weeks. The patients in the present study had an overall union rate of 96%. Complications included 1 nonunion, 1 superficial wound infection, 1 wound dehiscence, 1 case of symptomatic hardware, and 2 patients with symptomatic hallux interphalangeal joint arthralgia. The mean visual analog pain score preoperatively was 6.64 (range 4 to 8) and postoperatively was 0.6 (range 0 to 4). In conclusion, we found that immediate full weightbearing after first metatarsophalangeal joint fusion in the context of interfragmentary compression and locked plating techniques is a safe, predictable postoperative protocol that allows for a successful fusion interval and an early return to regular activity.     

Stability of Locking Plate and Compression Screws for Lapidus Arthrodesis: A Biomechanical Comparison of Plate Position

Lapidus (first tarsometatarsal joint) arthrodesis is an established and widely used procedure for the management of moderate to severe hallux valgus, especially in cases involving hypermobility of the first tarsometatarsal joint. Multiple fixation methods are available, and several previous investigations have studied the relative strengths of these methods, including dorsomedial and plantar plating comparisons. However, these studies compared plates of varying designs and mechanical properties and used varying modes of compression and interfragmentary screw techniques. The present study mechanically investigated the resulting motion, stiffness, and strength of identical locking plate constructs fixed at various anatomic positions around the first tarsometatarsal joint. In a bench-top study, fourth-generation composite bones were divided into 3 fixation groups, each having identical interfragmentary screw applications, and randomized to 1 of 3 plate positions: dorsal, medial, or plantar. The plates applied in each case were identical locking plates, precontoured to fit the anatomy. Each construct was experimentally tested using a cantilever bending approach. The outcomes obtained were stiffness, yield force, displacement at yield, ultimate force, and displacement at ultimate force. The plantar plate position showed superior initial stiffness and force to ultimate failure. The plantar and medial plate positions exhibited superior force to yield. The medial plate position was superior regarding displacement tolerated before the yield point and catastrophic failure. The dorsal plate position was not superior for any outcome measured. Plantar and medial plating each offered biomechanical benefits. Clinical studies using similarly matched constructs are required to show whether these findings translate into improved clinical outcomes.     

Early Results of Immediate Weightbearing Following First Tarsometatarsal Joint Arthrodesis With Plantar Locking Plate and Dorsal Compression Screw

Arthrodesis of the first tarsometatarsal joint (TMT1) reduces pathologic angles at the anatomic center of rotation of angulation and presents a substantial correction potential in 3 planes in the treatment of hallux abductovalgus. The optimal fixation method remains unclear since prevailing dorsomedial locking plates and/or compression screws depict elevated implant-associated complications. Medical records of 49 patients that underwent 53 TMT1 arthrodeses in hallux abductovalgus interventions were included. Median average visual analog scale scores decreased (p < .001) from 6.8 (range 4-10) to 2.7 (range 0-10), first intermetatarsal angles were reduced (p < .001) from 17.39° (range 12°-28°) to 7.16° (range 3°-12°), standing lateral first metatarsal angles improved (p < .001) from 21.66° (range 12°-29°) to 23.94° (range 14°-31°) and tibial sesamoid positions were plantarized (p < .001) from 6.02° (range 4°-7°) to 2.79° (range 1°-6°). Plantar plating allowed immediate weightbearing with transition to normal shoe gear at 6 weeks. Complications occurred in 6 (11.34%) feet including 1 (1.89%) nonunion, 1 (1.89%) delayed union, 1 (1.89%) hallux varus, 1 (1.89%) incomplete recurrence, 1 (1.89%) minor dehiscence, and 1 (1.89%) hardware irritation. Plantar locking plates combined with a dorsal compression screw presented a favorable tension-side implant location that closed the fusion site under load. This facilitated substantial reductions in complications, pathologic angles, and pain.     

Case Report: A Technique to Remove a Jammed Locking Screw from a Locking Plate

Background  

Locking titanium plates revolutionized the treatment of osteoporotic and metaphyseal fractures of long bones. However as with any innovation, with time new complications are identified. One of the problems with titanium locking plates is removal of screws, often attributable to cold welding of screw heads into the locking screw holes. Several techniques have been described to overcome this problem. We describe a new easy technique to remove a jammed locking screw in a locking plate that is easily reproducible and suggest an algorithm to determine the method to remove screws from locking plates.     

Effects of the Lapidus Arthrodesis and Chevron Bunionectomy on Plantar Forefoot Pressures

Hallux valgus with or without first ray insufficiency has been strongly implicated as a contributing factor in lesser metatarsal overload. The principle goals of a bunionectomy are to relieve the pain, correct the deformity, and restore first metatarsophalangeal joint congruity. Until now, little evidence has been available to assess the effects of bunionectomy procedures on forefoot pressure. The primary aim of the present prospective study was to evaluate the preoperative and postoperative plantar pressures after 2 specific bunionectomies: the chevron bunionectomy and Lapidus arthrodesis. A total of 68 subjects, 34 in each group, were included for radiographic and pedographic evaluation. Both procedures demonstrated radiographic improvements in the mean intermetatarsal and hallux abductus angles. The mean hallux plantar pressure decreased significantly in both procedure groups (p < .001). However, Lapidus group exhibited an increase in the mean fifth metatarsal head plantar pressure (p = .008) and pressure under the fifth metatarsal as a percentage of the total forefoot pressure (p = .01). Furthermore, the pressure under the second metatarsal as a percentage of the total forefoot pressure decreased significantly (p = .01). This study suggests that the Lapidus arthrodesis and chevron bunionectomy both provide correction for hallux valgus deformity, but when comparing forefoot load sharing pressures, the Lapidus arthrodesis appeared to have greater influence on the load sharing distribution of forefoot pressure than did the bunionectomy employing the chevron osteotomy.     

Addressing Transverse Plane Instability in the Modified Lapidus Arthrodesis: A Comparative Study of Screw Versus Suture and Button Fixation Device Technique

The Lapidus arthrodesis is a powerful procedure for the correction of hallux valgus with metatarsus primus varus. Yet, first ray instability may persist despite correction of the primary deformity with 2 crossed screw fixation. A third screw is often utilized as the additional point of fixation for noteworthy residual transverse plane motion, but it is not without potential complications. The suture and button fixation device may be an appropriate alternative to the third screw construct. This retrospective cohort study identified clinical / radiographic outcomes and complication rates following a third point of fixation with either a screw or suture and button fixation device in patients undergoing a modified Lapidus arthrodesis. One surgeon performed all of the Lapidus procedure with a third screw while the other surgeon performed all with a suture and button fixation device. Of 136 consecutive patients who underwent a modified Lapidus arthrodesis, 83 (61%) patients required a third point of fixation for satisfactory stabilization of the first ray. Surgical technique was similar between the 2 surgeons; however, one utilized the suture and button fixation device method (n = 36), while the other used a third screw for fixation (n = 47). Many of the clinical outcomes, radiographic results, and the union rate were similar between the 2 methods. Nineteen (40%) complications occurred in the third screw group compared to 6 (17%) in the suture and button fixation device group. However, the third screw group demonstrated 100% maintenance of deformity correction at 1 year versus 95% in the suture and button fixation device group. Although fixation with a suture and button fixation device was associated with fewer complications, a larger study is necessary to determine if these variations are statistically significant.     

Revision Lapidus Arthrodesis: Rate of Union in 17 Cases

This multicenter study retrospectively reviewed the medical records and radiographs of 15 consecutive patients (17 feet; mean patient age, 54.1 years), who underwent revision "bone-block" Lapidus arthrodesis for a symptomatic nonunion. In all cases but one, the procedure was performed with ipsilateral autogenous bone grafting. All cases used either screw fixation or a combination of screw and plate fixation. Patients were monitored for a minimum of 6 months postoperatively to assess clinical and radiographic union. Successful union was seen in 14 (82%) of the 17 feet that underwent revision. Nonunion was documented in 3 (18%) cases. These results support a favorable rate of union with the described surgical technique. Chi-square tests of association were used to determine whether gender, fixation, bone stimulation, and smoking were predictive of or associated with bone healing. Active smoking in the perioperative period was a predictor of nonunion (P = .05). Based on these findings, the authors recommend aggressive preoperative counseling, and smoking should be considered a relative contraindication to revision surgery.     

Functional Capabilities After First Metatarsal Phalangeal Joint Arthrodesis Using a Locking Plate and Compression Screw Construct

Arthrodesis of the first metatarsal phalangeal joint (MTPJ) is a widely utilized surgical procedure for a wide array of metatarsal pathologies. This study aims to explore the functional limitations following first MTPJ arthrodesis, overall satisfaction and patient's abilities to achieve activities of daily living (ADL). This prospective cohort study assessed functional limitations as well as footwear and lifestyle restrictions using several questionnaires. One hundred and three participants who had a first MTPJ arthrodesis under the care of a single surgeon were recruited. Pre- and postoperative patient-reported outcome measures were recorded. The American Orthopaedic Foot and Ankle Score (AOFAS) and the Manchester-Oxford Foot Questionnaire were also used to further examine functional status. Hallux valgus angle (HVA) and intermetatarsal angle (IMA) were compared using preoperative and postoperative weightbearing radiographs and successful fusion was recorded. Complications were documented and are discussed in detail. The duration of follow-up was more than 12 months. There was one nonunion in the cohort while 2 patients experienced delay to fusion. Approximately 97% of patients were very satisfied with the procedure and their ability to achieve ADLs post operatively. A further 82.5% of patients were able to return to wearing nonadaptive footwear. The mean reduction in HVA and IMA was 21.78° and 6.84°, respectively. This study demonstrates the safe and successful use of a compression screw/locking plate construct for arthrodesis of the first MTPJ. Furthermore, the study provides clear evidence of high levels of functionality after the procedure with statistically significant differences (p value <.05) in all 4 facets of the AOFAS questionnaire as well as several notable differences in activity levels and footwear restrictions pre and postoperatively.     

Midfoot Arthrodesis Using a Locking Anterior Cervical Plate as Adjunctive Fixation: Early Experience With a New Implant

A retrospective review was performed on 14 patients (20 arthrodeses) who had undergone midfoot arthrodesis with a semi-constrained, locking anterior cervical plate as a form of adjunctive fixation. Fusion sites where the plate was used for the purpose of arthrodesis included the talonavicular joint, medial naviculocuneiform joints, first metatarsal cuneiform joint, and the calcaneal cuboid joint. All arthrodesis sites used one other type of fixation for the purpose of axial compression. Twenty midfoot arthrodesis sites went on to radiographic union at a mean of 9.1+/-1.5 weeks. A single complication of hardware irritation occurred in one patient that resolved after plate removal. This semi-constrained, locking anterior cervical plate appears to be a viable adjunct to fixation constructs for the purpose of midfoot arthrodesis.     

Biomechanical Comparison of Locking Plate and Cancellous Screw Techniques in Medial Malleolar Fractures: A Finite Element Analysis

As the commonly used fixation strategy of medial malleolar fractures, cancellous screws (CS) have been challenged for instability, bone destruction, and metal prominence. It is still unclear whether a locking compression plate (LCP) is a better choice in such fractures. Our purpose is to compare the mechanical efficacy of LCP with traditional 4.0-mm CS for transverse, oblique, and vertical medial malleolar fractures by using finite element analysis. In this study, 3-dimensional models of the distal tibia were reconstructed from a computed tomography scan of a young healthy male adult. Conditions included 3 fracture lines at 30°, 60°, and 90°; 2 groups of fixation (LCP and CS); and 3 adduction loads of 300, 500, and 700 N applied to the medial malleolar joint surface. The proximal part of the tibia was fixed for all degrees of freedom. The fracture displacements of the LCP were smaller than those of CS (p < .05). The stiffness of the LCP constructs was much higher than that of the CS constructs, especially in the 90° fractures (490.3 versus 163.6 N/mm). The mean stress around the CS was higher than that in LCP for 60° and 90° fractures, but there was no difference for 30°. Maximal bone stress increased (19.84 to 50.86 MPa) and concentrated on cortical bone in LCP, whereas it concentrated on cancellous bone in CS. The results showed that LCP could improve stability, preventing bone destruction in oblique and vertical medial malleolar fractures. However, in transverse fractures, CS provides sufficient stability, with no need to use LCP.     

Mechanical Comparison of Cortical Screw Fixation Versus Locking Plate Fixation in First Metatarsal Base Osteotomy

The oblique closing base wedge osteotomy has been used for surgical treatment of moderate to severe hallux valgus deformities with an intermetatarsal angle typically greater than 15°. Several postoperative complications have been identified that relate to failure of the fixation construct used to fixate the osteotomy, especially when that construct has been subjected to a vertical load. We performed a mechanical analysis comparing 2 constructs used to fixate oblique osteotomies of the first metatarsal using composite first metatarsals. An oblique base osteotomy was uniformly performed on 40 composite first metatarsals. Of the 40 specimens, 20 were fixated with a locking plate construct and 18 with a cortical screw construct, consisting of an anchor and compression screw (2 specimens from the latter group were excluded because of hinge fracture). Each specimen was loaded in a materials testing machine to measure the maximum load at construct failure when a vertical force was applied to the plantar aspect of the metatarsal head. The mean load to failure for the locking plate construct was significantly greater than the cortical screw construct (190.0 ± 70 N versus 110.3 ± 20.3 N, p < .001). Our study results have demonstrated that the locking plate construct was able to withstand a significantly greater vertical load before failure than was the 2-cortical screw construct in oblique osteotomies performed at the base of composite first metatarsals.     

Screw Internal Fixation and Ilizarov External Fixation: A Comparison of Outcomes in Ankle Arthrodesis

The purpose of this study was to compare the mid-term clinical outcomes between screw internal fixation and Ilizarov external fixation in patients who underwent ankle arthrodesis and to elucidate the differences between the 2 fixation methods. This study investigated 43 ankles in 41 patients who underwent ankle arthrodesis at 1 of the 2 study institutions. There were 15 men and 26 women, and their mean age was 66.2 (range 49 to 87) years. The primary disease included osteoarthritis (OA) (79%), rheumatoid arthritis (RA) (16.3%), and Charcot joint (4.7%). Patients were divided into 2 groups depending on the surgical approach: the screw group (S) and the Ilizarov group (I). The following items were evaluated and compared between the 2 groups: patient characteristics, Tanaka-Takakura classification based on preoperative plain X-ray images, duration of surgery, blood loss, surgical complications, time to start weightbearing, and the Japanese Society of Surgery of the Foot (JSSF) standard rating system for the ankle-hindfoot. Duration of surgery was significantly shorter in the S group (162.3 versus 194.9 min), and the amount of blood loss was also significantly lower in the S group (29.2 versus 97.5 ml). Preoperative JSSF scale was significantly lower in the I group (44.8 versus 33), but postoperative JSSF scale was not significantly different between the 2 groups (82.1 versus 77.9). The S group had satisfactory clinical outcomes with a shorter duration of surgery and smaller amount of blood loss than the I group. However, severe patients in the I group achieved similar treatment outcomes.     

The Lapidus Arthrodesis: Examining the Effect of the Metatarsal Base Transfixion Screw

The modified Lapidus bunionectomy is a useful and highly powerful procedure for correcting hallux abducto valgus. Traditionally reserved for “severe” deformities, this procedure has seen a recent resurgence in the podiatric community for its unique ability to achieve tri-planar correction of this challenging deformity. Although this procedure has been extensively studied in both biomechanical labs and the clinical arenas, no clear consensus has been achieved regarding optimal fixation for this thought-provoking procedure. The current study examined the differences in strength between commercially available 5-hole locking plates with interfragmentary compression vs a crossed-screw with a third “transfixation” screw construct in a controlled setting. Ten fresh-frozen cadaveric match pair limbs (20 total limbs) were used to complete this study. Ten limbs were randomly assigned to a 3-screw construct. The other 10 contralateral limbs were assigned to a commercially available 5-hole locking plate (5 stainless steel and 5 titanium alloy) with an interfragmentary lag screw construct. The first rays were then isolated and potted into a 4-point bending device. The specimens were loaded to failure in a servohydraulic load frame at a controlled rate. Failure was defined as catastrophic or 3 mm of plantar gapping at the arthrodesis site. The mean maximal load to failure was 310.9 ± 109.4 N for the 3-screw construct. The mean maximal load to failure for the locking plate constructs was 264.1 ± 100.9 N. This difference was not statistically significant (p = .328). These results suggest that a 3-screw construct for Lapidus arthrodesis is as strong as commercially available locking plate constructs.     

经皮微创内侧锁定板固定治疗胫骨下段骨折

目的观察经皮微创钢板固定（minimally invasive percutaneous plate osteosynthesis,MIPPO）技术治疗胫骨下段骨折的临床疗效。方法对2009年1月至2011年2月收治的29例胫骨下段骨折病例采用MIPPO技术结合锁定加压接骨板（locking compression plate,LCP）治疗,其中男23例,女6例;年龄20~71岁,平均47.7岁。对临床疗效进行回顾性分析。结果其中26例获得随访,时间12~24个月,平均14个月。1例软组织感染,骨折均愈合,愈合时间3~6个月,平均4.2个月。按Johner-Wruhs评分标准评定疗效,其中优23例,良2例,可1例,优良率为96.2%。结论采用MIPPO技术结合LCP治疗胫骨下段骨折,具有创伤小、手术时间短、骨折愈合率高、功能好的优点,是治疗胫骨下段骨折的理想方法。但需重视小腿内侧软组织条件,严格掌握适应证,避免软组织并发症。