Associated correction of forefoot alignment with hindfoot fusion for pes planovalgus deformity

BackgroundThe present study aimed to investigate changes in hallux alignment after corrective surgery for adult-acquired flatfoot deformity (AAFD).Patients and methodsThe present study retrospectively investigated the changes of hallux alignment in 37 feet (33 patients) which were treated with double or triple arthrodesis of the hindfoot for AAFD between 2015 and 2021 and could be followed up to one year postoperatively.ResultsHallux valgus (HV) angle significantly decreased by a mean 4.1° among the whole 37 subjects and by a mean 6.6° among the 24 subjects who had a preoperative HV angle of 15° or more. Those who had HV correction (HV angle correction ≥ 5°) demonstrated more near-normal postoperative alignment of the medial longitudinal arch and hindfoot than those without HV correction.ConclusionsHindfoot fusion for AAFD could improve preoperative HV deformity to some degree. HV correction was associated with proper realignment of the midfoot and hindfoot.Level of evidenceLevel IV; retrospective case series     

Three-dimensional displacement after a medializing calcaneal osteotomy in relation to the osteotomy angle and hindfoot alignment

BackgroundA medializing calcaneal osteotomy is frequently performed to correct adult-acquired flatfoot deformities, but there is lack of data on the associated three-dimensional variables defining the final correction. The aim of this study was to assess the correlation between the pre-operative hindfoot valgus deformity and calcaneal osteotomy angles and the post-operative calcaneal displacement.MethodsWeight-bearing CT scans obtained pre- and post-operatively were retrospectively analyzed for sixteen patients. Corresponding three-dimensional bone models were used to measure valgus deformity pre- and post-operatively, inclination of the osteotomy and displacement of the calcaneus. Linear regression was conducted to assess the relationship between these measurements.ResultsOn average, the hindfoot valgus changed from 13.1° (±4.6) pre-operatively to 5.7° (±4.3) post-operatively. A mean inferior displacement of 3.2 mm (±1.3) was observed along the osteotomy with a mean inclination of 54.6° (±5.6), 80.5° (±10.7), −13.7° (±15.7) in the axial, sagittal and coronal planes, respectively. A statistically significant positive relationship (p < .05, R² = 0.6) was found between the pre-operative valgus, the axial osteotomy inclination, and the inferior displacement.ConclusionsThis study shows that the degree of pre-operative hindfoot valgus and the axial osteotomy angle are predictive factors for the amount of post-operative inferior displacement of the calcaneus. These findings demonstrate the added value of a computer-based pre-operative planning in clinical practice.Level of evidence II Prospective comparative study.     

副舟骨切除胫后肌腱止点重建跟骨内移截骨术治疗与副舟骨相关的平足症

 目的 探讨副舟骨切除胫后肌腱止点重建跟骨内移截骨术治疗与副舟骨相关的平足症的临床疗效。方法 2009年3月至2011年10月,采用副舟骨切除胫后肌腱止点重建跟骨内移截骨术治疗与副舟骨相关的平足症13例(16足),男4例,女9例;年龄18～64 岁,平均41.3岁。单足10例,双足3例;均有明显的跟骨外翻。术后以美国足踝外科协会(American Orthopaedic Foot and Ankle Society,AOFAS)踝与后足评分评估后足功能,于X线片上测量足弓高度、跟骨倾斜角(CI)、距跟角(TC)、距骨-第一跖骨角(TMT)。结果 13例均获得随访,随访时间12~31个月,平均16.8个月。术后6个月时11例(13足)无任何疼痛,2例(3足)有长距离行走后足部疼痛。术后随访时AOFAS评分从术前(52.4±6.4)分提高至(88.1±2.8)分;负重侧位X线片上足弓高度从(3.8±0.3) mm提高至(12.0±1.1) mm,CI从9.5°±1.1°提高至20.1°±1.5°,TC从47.3°±2.5°改善至32.3°±2.5°,TMT从17.6°±1.6°改善至6.8°±1.0°;负重正位X线片上TC从39.5°±2.3°改善至26.2°±2.0°,TMT从15.2°±1.7°改善至6.3°±1.0°;轴位X线片上跟骨外翻角从11.3°±1.4°改善至4.2°±2.0°。结论 对与副舟骨相关的平足症的治疗,当存在后足外翻畸形时,副舟骨切除胫后肌腱止点重建跟骨内移截骨术可以明显缓解疼痛,有效矫正畸形,近期疗效良好。     

Reconstruction of the pediatric flexible planovalgus foot by using an Evans calcaneal osteotomy and augmentative medial split tibialis anterior tendon transfer

Seventeen consecutive pediatric patients (34 feet) underwent reconstruction of flexible pes planovalgus deformity between 1994 and 1999. The average follow-up was 24.9 months (range, 8 to 48 months). All patients underwent a medial split tibialis anterior tendon transfer/tenodesis in combination with an Evans calcaneal-lengthening osteotomy, Kidner or modified Kidner procedure, and tendo-Achilles lengthening. Various angular parameters were measured both preoperatively and postoperatively, and improvement in each was noted. The calcaneal pitch improved by an average of 26 degrees (85.88%), the lateral talometatarsal angle improved by an average of 26.4 degrees (96.15%), the lateral talocalcaneal angle improved by an average of 14.8 degrees (34.26%), the anteroposterior talometatarsal angle improved by an average of 21.9 degrees (81.92%), the anteroposterior talocalcaneal angle improved by an average of 15.9 degrees (37.95%), the cuboid abduction angle improved by an average of 13.8 degrees (87.34%), and the talonavicular coverage angle improved by an average of 26.7 degrees (94.68%). Postoperative improvement of all angular measurements was statistically significant at the 95% confidence level (P =.05). In addition, American Orthopedic Foot and Ankle Society hindfoot/ankle scoring was performed preoperatively, 3 months after the second foot surgery, and at the time of maximal follow-up. A preoperative average score of 68.59 improved to 85.76 at 3 months after the second foot surgery, and improved to 96.55 at the time of the last follow-up. All 17 patients were satisfied with their surgical result because all returned for correction of the contralateral foot. All patients indicated a uniform willingness to have these procedures performed again.     

A novel technique of minimally invasive calcaneal osteotomy for intractable insertional Achilles tendinopathy associated with Haglund deformity

BackgroundTo date, minimally invasive surgery (MIS) involving calcaneal osteotomy for Haglund deformity associated with intractable insertional Achilles tendinopathy has not been reported. This study presents the radiographic and clinical outcomes of our novel MIS-dorsal closing wedge calcaneal osteotomy (DCWCO) technique compared to open Haglund resection. We hypothesized that earlier clinical improvement after MIS-DCWCO could be achieved by leaving the Achilles tendon insertion site untouched.MethodsWe retrospectively reviewed and compared the clinical and radiographic parameters of patients who underwent MIS-DCWCO (11 cases) or open Haglund resection (14 cases) between January 2012 and June 2019. The minimum duration of follow-up for inclusion was 18 months. We measured the calcaneal pitch, Meary’s, Fowler-Philip, and Böhler’s angles. Clinical outcomes were evaluated using the visual analogue scale (VAS) and Victorian Institute of Sports Assessment-Achilles (VISA-A) scores measured preoperatively and at 3, 6, 9, 12, and ≥18 months, postoperatively.ResultsIn both groups, the Meary’s and calcaneal pitch angles did not change significantly, whereas the Fowler-Philip and Böhler’s angles were significantly changed postoperatively. Significant improvements in VAS and VISA-A scores were observed in both groups (P < 0.001). The extent of correction of the four radiographic and two clinical parameters were not significantly different between the two groups. However, VAS and VISA-A scores at postoperative 6 months were significantly different, whereas these parameters were not significantly different at all other time points.ConclusionBoth techniques provided similar postoperative clinical and radiographic improvement. However, MIS-DCWCO achieved earlier clinical improvement than open Haglund resection.Level of evidenceLevel III, comparative series.     

The outcome of super-cutaneous locked plate fixation with percutaneous reduction of displaced intra-articular calcaneal fractures

IntroductionSupercutaneous (external) fixation with locking plate is utilized for fixation of long bone fractures. One retrospective study for open reduction and supercutaneous fixation of the calcaneus is reported. We prospectively evaluated the use of this method of fixation combined with percutaneous reduction.Materials and methodsBetween January 2014 and June 2015, 32 displaced calcaneus fractures in 30 patients were stabilized with percutaneous reduction and super-cutaneous fixation. They were 24 males and six females. The mean age was 37.9 ± 5.7 years (21–55). All cases were closed. The time to surgery, complications, radiographic alignment, and time to radiographic union were recorded. Clinical results at the final follow-up were assessed by evaluating Bohler’s angles for the radiographic alignment, and the system of the American Orthopedic Foot and Ankle Society (AOFAS) for the functional outcome.ResultsAccording to the Sanders’ classification, two cases were type II, 17 cases were type III and 13 cases were type IV. The preoperative average Bohler’s angle was 10.57° ± 4.8. The postoperative X-ray films demonstrated that the average Bohler’s angle improved to 29.07° ± 5.9 (p < 0.001). At the time of radiologic healing (about 3 months), the plates and screws were removed under general anesthesia. The average follow-up was 13.2 months (11–18). Four cases (type IV) showed mal-union and heel pain. According to (AOFAS) rating, the fine score was 87.1 ± 17.1 points.ConclusionSuper-cutaneous fixation with percutaneous reduction of calcaneal fracture is an effective method in type II and III and can be effective with type IV but with less favorable results.     

Evans跟骨外侧延长术治疗距跟联合合并后足外翻畸形

目的探讨Evans跟骨外侧延长术治疗距跟联合合并后足外翻畸形的疗效。方法2014年1月—2017年10月,采取Evans跟骨外侧延长术治疗10例(13足)距跟联合合并后足外翻畸形患者。男6例(8足),女4例(5足);年龄13~18岁,平均15.8岁。病程10~14个月,平均11.5个月。患侧跟骨外翻、前足外展、足弓低平。疼痛部位:跗骨窦4足、距跟联合5足、踝关节4足。Silverskiold试验腓肠肌腱膜紧张3例(4足),跟腱挛缩7例(9足)。术前美国矫形外科足踝协会(AOFAS)踝与后足评分为(46.54±9.08)分,行走1 km后疼痛视觉模拟评分(VAS)为(6.54±0.88)分。术后采用AOFAS踝与后足评分、VAS评分,以及X线片测量距骨-第1跖列角(talar-first metatarsal angle,T1MT)、距舟覆盖角(talonavicular coverage angle,TCA)、距骨倾斜角(talar-horizontal angle,TH)、跟骨倾斜角(calcaneal pitch angle,CP)、跟骨外翻角(heel valgus angle,HV),评价手术疗效。结果术后切口均Ⅰ期愈合。10例患者均获随访,随访时间12~30个月,平均18个月。末次随访时,AOFAS踝与后足评分为(90.70±6.75)分,VAS评分为(1.85±0.90)分,均较术前明显改善(t=-23.380,P=0.000;t=35.218,P=0.000)。X线片复查示截骨均达骨性愈合,愈合时间为2~4个月,平均3个月。末次随访时,T1MT、TCA、TH、HV均较术前明显降低,CP明显提高,差异有统计学意义(P<0.05)。随访期间1例(1足)疼痛缓解不明显,1例(1足)出现腓肠神经皮支损伤症状。结论对于距跟联合合并后足外翻畸形患者,Evans跟骨外侧延长术可以有效纠正畸形、缓解疼痛。     

循原骨折线截骨矫正跟骨骨折畸形愈合

目的 探讨循原骨折线截骨矫正跟骨骨折畸形愈合方法的可行性.方法 2004年8月至2007年5月,跟骨骨折畸形愈合患者25例28足,男23例26足,女2例2足;年龄22～56岁,平均31岁;受伤至手术时间1.5～12个月,平均4.6个月.采用循原骨折线截骨术进行治疗.按照Zwipp和Rammelt跟骨骨折畸形愈合的分类方法进行分类,其中Ⅲ型11例12足,Ⅳ型14例16足.术前均摄双足跟骨侧位、轴位X线片及行CT检查,12例患者(14足)行三维CT重建.根据Sander及Essex-Lopresti分类,参考原始X线片对不同骨折类型制定截骨线,重现原始骨折.根据CT轴位载距突及外侧骨块所带关节面的宽度和轴位骨折线的斜度从前外上到后内下斜行截骨,恢复跟骨的高度,将后关节骨折块向后上撬起,使塌陷的后关节面骨块复位.骨缺损处,用劈下的跟骨外侧壁填塞植骨,或取自体髂骨植骨,最后用钢板螺钉固定.结果 24例26足获得随访,随访时间10～16个月,平均12个月.骨折愈合时间10～14周,平均12周.2例发生伤口感染,经抗生素治疗后10周取出钢板伤口愈合.无一例发生钢板螺钉断裂和骨折再移位.按照Maryland足部评分标准,优10足,良12足,可4足,优良率84%.结论 循原骨折线截骨重现原始骨折,可恢复跟骨的骨性结构,能更好地矫正跟骨各方位畸形,同时保留距下关节,减少了手术对足踝功能的影响,近期疗效满意.     

Clinical outcomes and complications of the Zadek calcaneal osteotomy in Insertional Achilles Tendinopathy: A systematic review and meta-analysis

BackgroundThe Zadek osteotomy, a dorsal closing wedge osteotomy of the calcaneus, has been described as a treatment option in patients with Insertional Achilles Tendinopathy (IAT) that have failed conservative management. The aim of this study was to evaluate the clinical outcomes and the complications of the Zadek for the management of IAT.MethodsPubMed, EMBASE and Cochrane Central Register of Controlled Trails (CENTRAL) were searched for all studies to November 2022. PRISMA guidelines were followed. The overall estimates of effect were presented as Weighted Mean Difference (WMD) and 95 % confidence intervals (CIs). Meta-analysis was conducted using the Review Manager Software (RevMan, Version 5.4).ResultsTen studies with 232 patients were included. Functional scores and pain levels were significantly improved after the Zadek osteotomy (p < 0.00001). There were a total of 22 complications reported in the included studies and they were all considered minor. The most common complications were superficial wound infection and sural nerve paraesthesia.ConclusionsThe Zadek osteotomy is a safe and effective procedure for patients with IAT. There are no well-designed randomized controlled trials in the literature assessing the outcomes of a Zadek osteotomy against alternate surgical treatments and future research should focus on this.Level of evidenceII.     

Increased rates of delayed union after percutaneous Akin osteotomy

Background

Akin osteotomy is a well-known surgical procedure in forefoot surgery. When performing percutaneously, we have found a lot of delayed unions on follow up X-rays. The objective of this study was to assess the incidence of delayed union when performing a percutaneous Akin osteotomy.

The Zadek calcaneal osteotomy in Haglund's syndrome of the heel: Clinical results and a radiographic analysis to explain its efficacy

Local debridement or decompression of the posterior heel in Haglund's syndrome yields variable results. This condition is sometimes due to an excessively long calcaneus rather than simply a large posterosuperior bony prominence. Failure to address this abnormality may explain the poor results in some series. We recently published a new measurement (the X/Y ratio) which, combined with the calcaneal pitch angle, assesses the abnormality of the shape of the calcaneus. The Zadek osteotomy strongly modifies that shape. We retrospectively reviewed 50 patients treated by a Zadek osteotomy at a mean 7 years follow-up using the AOFAS ankle-hindfoot score, the VISA-A score and Tegner scale. We measured only the X/Y ratio and the calcaneal inclination angle, as the classically described radiographic measurements in Haglund's syndrome are unreliable. We then assessed the condition of the distal end of the Achilles tendon with an MRI. Our results demonstrate excellent outcomes(40/50, 80%) following Zadek osteotomy and correspond to the change in pre- and post-operative measurements, especially the X/Y ratio. An algorithm using those geometrical measurements of the calcaneus is proposed for decision making in Haglund's syndrome.Level of clinical evidence: Level 3.     

Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy

Purpose

The purpose of this study was to evaluate the results of distal femur extension osteotomy and medial hamstring lengthening in the treatment of fixed knee flexion deformity in patients with spastic diparetic cerebral palsy.

Methods

A retrospective study was done in a group of 12 diparetic cerebral palsy patients. A distal femur extension osteotomy was performed as part of multilevel surgery on lower limbs. The fixed knee flexion deformity was measured during physical examination, whereas hip and knee flexion in the stance phase and anterior pelvic tilt were both analyzed at kinematics. The pre- and post-surgery results were compared and analyzed statistically. A medical record review was done in order to identify the complications. The mean follow-up was 28 months.

Results

A significant reduction of fixed knee flexion deformity at physical examination and knee flexion in the stance phase at kinematics was observed, but with no decrease in hip flexion. As a non-desired effect, there was an increase in anterior pelvic tilt after surgical procedures. With regard to complications, a single patient had skin breakdown at a calcaneous area on one side and the recurrence of deformity was seen in 27% of cases.

Conclusions

In this study, in which fixed knee flexion deformity did not exceed 40° before surgery, the distal femur extension osteotomy was effective in increasing knee extension in the stance phase. However, an increase in anterior pelvic tilt, deformity recurrence and necessity for walking aids are possible complications of this procedure.     

A comparison of union rates and complications between single screw and double screw fixation of sliding calcaneal osteotomy

Background

The number of screws used for sliding calcaneal osteotomy fixation has not been examined in the literature. The purpose of this paper is to examine this topic.

Biomechanical comparison of stability of tibiotalocalcaneal arthrodesis with two different intramedullary retrograde nails

BackgroundThe aim of the study was to compare the initial construct stability of two retrograde intramedullary nail systems for tibiotalocalcaneal arthrodesis (TTCF) (A3, Small Bone Innovations; HAN, Synthes) in a biomechanical cadaver study.MethodsNine pairs of human cadaver bones were instrumented with two different retrograde nail systems. One tibia from each pair was randomized to either rod. The bone mineral density was determined via tomography to ensure the characteristics in each pair of tibiae were similar. All tests were performed in load-control. Displacements and forces were acquired by the sensors of the machine at a rate of 64 Hz. Specimens were tested in a stepwise progression starting with six times ±125N with a frequency of 1 Hz for 250 cycles each step was performed (1500 cycles). The maximum load was then increased to ±250N for another 14 steps or until specimen failure occurred (up to 3500 cycles).ResultsAverage bone mineral density was 67.4 mgHA/ccm and did not differ significantly between groups (t-test, p = .28). Under cyclic loading, the range of motion (dorsiflexion/plantarflexion) at 250N was significantly lower for the HAN-group with 7.2 ± 2.3 mm compared to the A3-group with 11.8 ± 2.9 mm (t-test, p < 0.01). Failure was registered for the HAN after 4571 ± 1134 cycles and after 2344 ± 1195 cycles for the A3 (t-test, p = .031). Bone mineral density significantly correlated with the number of cycles to failure in both groups (Spearman-Rho, r > .69, p < 0.01).ConclusionsThe high specimen age and low bone density simulates an osteoporotic bone situation. The HAN with only lateral distal bend but two calcaneal locking screws showed higher stability (higher number of cycles to failure and lower motion such as dorsiflexion/plantarflexion during cyclic loading) than the A3 with additional distal dorsal bend but only one calcaneal locking screw. Both constructs showed sufficient stability compared with earlier data from a similar test model.Clinical relevanceThe data suggest that both implants allow for sufficient primary stability for TTCF in osteoporotic and consequently also in non-osteoporotic bone.Level of evidenceNot applicable, experimental basic science study.     

跟骨插入式钢板的研制及其在跟骨关节内移位性骨折手术中的应用

目的 研制一种适合于经跗骨窦切口经皮插入式的跟骨微创钢板,探讨其在移位性跟骨关节内骨折治疗中的疗效. 方法 自2006年9月至2008年9月经跗骨窦切口入路,采用跟骨经皮插入式钢板治疗跟骨关节内骨折38例(40足),其中SandersⅡ型22足(Ⅱa型6足,Ⅱb型14足,Ⅱc型2足),Ⅲ型18足(Ⅲab型7足,Ⅲac型10足,Ⅲbc型1足).根据X线片对手术前后跟骨高度、宽度、长度及跟骨Bohlers角和Gissanes角进行比较分析,并观察术后切口愈合情况.采用Maryland足部评分系统评价临床功能疗效. 结果 所有患者术后获得3～24个月(平均12个月)随访,X线片示术后跟骨高度、宽度、长度及跟骨Bohlers角和Gissanes角均获得满意矫正,与术前比较,差异均有统计学意义(P<0.01).Maryland足部评分系统显示:优32足,良6足,可2足,优良率95.0%.术后未发现明显并发症. 结论 采用经跗骨窦切口跟骨插入式钢板治疗跟骨关节内移位性骨折不仅可以获得满意的疗效,而且能够有效避免术后并发症的发生.     

Medial malleolar osteotomy for the correction of tibiotalar varus deformity during total ankle arthroplasty: Results in 95 ankles

BackgroundThe importance of deformity correction before or during total ankle replacement (TAR) has been recognized for a long time. Our results of TAR, combined with medial malleolar lengthening osteotomy, for the reconstruction of osteoarthritic ankles with varus deformity are hereby reported.MethodsAll ankles in which a medial malleolar osteotomy was performed during implantation of an ankle prosthesis during the period 1998–2018 were filtered out of our database. Preoperative coronal talar alignment was evaluated by measuring the angle between the tibial shaft and talar dome on the weightbearing mortise ankle radiograph. Patient-reported outcomes were measured with the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM). A Kaplan-Meier survival curve was constructed and the number of revisions per 100 observed component years was calculated for interprosthetic comparison.ResultsA total of 95 TARs were included, consisting of the Alpha Ankle Arthroplasty (n = 22); Buechel-Pappas (n = 14) and the Ceramic Coated Implant Evolution (n = 59) prostheses. The preoperative average talar angle in these ankles was 12.4 degrees varus. In 33% (31/95) corrective procedures, in addition to the medial malleolar osteotomy, were performed. A reoperation rate of 44% (42/95) was found, including 28 revisions (revision rate 29% (4% septic; 25% aseptic) at an average follow-up of 5.9 years, resulting in a survival of 0.69 for the total cohort at 10 years of follow-up.At an average follow-up of 6.6 years the average FAOS scores were: FAOS_symptoms 66, FAOS_pain 73, FAOS_function 78, FAOS_sport 45 and FAOS_{quality of life} 56 respectively. The FAAM_adl score averaged 64.ConclusionThis is the largest cohort of TAR combined with medial malleolar osteotomy to date. A 29% revision rate at 5.9 years of average follow-up compares unfavorably with regular cohort studies and with most other results in varus-deformed ankles. Scores on the FAOS and FAAM are comparable to those obtained in regular cohorts with similar length of follow-up. TAR in varus-deformed ankles necessitating medial malleolar osteotomy has an even higher failure rate than regular TAR. Obtaining a stable prosthesis with a neutrally-aligned hindfoot at the end of the procedure is of paramount importance.Level of evidenceIV.     

Dorsal closing wedge calcaneal osteotomy for the treatment of Insertional Achilles Tendinopathy: A technical tip to optimize its results and reduce complications

Background

Dorsal closing wedge calcaneal osteotomy is a technique for the treatment of Haglund’s triad, which is considered a safe procedure with good results. However, one of the complications that could lead to revision operation is the nonunion of the osteotomy and failure of osteosynthesis. This is attributed to instability of the osteotomy site and proximal migration of the posterior calcaneal process due to breakage of plantar bone-bridge at the apex of the wedge osteotomy.

手术治疗移位的跟骨关节内骨折疗效及并发症分析

[目的]分析影响切开复位内固定或撬拨术治疗移位的跟骨关节内骨折的疗效及并发症的相关因素。[方法]回顾并随访了采用切开复位内固定或撬拨治疗的移位的跟骨关节内骨折27例共29个跟骨，随访7～60个月，用美国足与踝关节协会踝与后足评分标准评价术后功能。[结果]评分结果：53～100分，平均87．2分，结果优良。Sanders Ⅲ、Ⅳ型骨折功能结果较Ⅱ型骨折差。[结论]移位的跟骨关节内骨折应采取手术治疗。只要注意无创操作，延长的外侧L形切口并不增加感染风险。损伤的严重程度和手术的质量是影响预后的重要因素。     

下颌升支矢状劈开术联合术后快速正畸矫治下颌前突畸形

目的：探讨应用下颌升支矢状劈开术联合术后快速正畸建[牙合]矫治下颌前突畸形方法的可行性及优缺点。方法：2000年1月～2005年12月,应用下颌升支矢状劈开术联合术后快速正畸建[牙合]共矫治43例下颌前突畸形患者,所有患者术前均未接受过正畸治疗。结果：43例患者通过下颌升支矢状劈开术后退下颌骨,联合术后快速正畸3～7个月,基本建立良好咬合关系,恢复正常咬合功能。随访6个月～3年,效果稳定。结论：下颌前突畸形采用下颌升支矢状劈开术联合术后快速正畸,不但能够显著地改善颌骨畸形,而且可以快速建立正常咬合关系。     

Biomechanical investigation of tibial tubercle osteotomy fixed with various screw configurations

Introduction

To date, the effects of various screw configurations on the stability of tibial tubercle osteotomy (TTO) are not completely understood. Hence, the first aim of this study is to evaluate the stability of TTO under various screw configurations. The second aim is to evaluate the internal stresses in the bone and the contact forces on the bone fragment that are developed by the tibia and screws in response to the applied load after the equilibrant is revealed.