Statistical analysis of bone mineral density using voxel‐based morphometry—an application on proximal sesamoid bones in racehorses

Voxel‐based morphometry (VBM) is a computational technique that has been used to analyze statistical differences between groups of MR brain images. This study outlines a new VBM pipeline, designed for determining statistical variation in bone mineral density (BMD). CT images of proximal sesamoid bone (PSB) specimens from the right forelimb of six racehorses that had suffered PSB fractures were compared with six age‐matched control specimens. Following segmentation, masked gray‐scale images were co‐aligned to a statistical template generated with all 12 CT datasets iteratively. Student t‐tests were performed voxel‐by‐voxel on spatially aligned 3D images to reveal significant differences in the spatial variation of bone density between the fracture and control groups. Overall density and densities from the axial and abaxial areas of PSBs were compared between groups. The BMD in abaxial regions of the medial and lateral PSBs of the fracture group were 12.7% (p = 0.044) and 13.5% (p = 0.047) higher, respectively, than controls. The overall mean density of paired PSB and the medial and lateral PSBs separately were higher in the fracture group. The VBM pipeline facilitates detailed comparison of density variation between bone groups at the voxel level. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1230–1236, 2011     

Intramedullary pin fixation in clavicular fractures: A study comparing the use of small and large pins

The S-shaped clavicle poses a problem for intramedullary pin fixation. Stability of fracture fixation is closely related to the length of intramedullary pin engagement. This study was carried out to determine the engagement length of intramedullary pins into clavicular fractures using a small and a large pin. Seven pairs of fresh cadaveric clavicles were prepared and arranged into Group 1 and Group 2 for paired study. A mid-third clavicular fracture was created at the junction of the two curves of the clavicle. In Group 1, a 3.2 mm diameter threaded Steinman pin was introduced into the medullary canal of the clavicle by retrograde technique and the medial fragment of the fracture was drilled until the pin perforated the bone cortex. In Group 2, a 4 mm diameter threaded Steinman pin was used in the same manner. The results showed that Group 1 had an average engagement of pin into the clavicle of 9.11 cm with a ratio to total length of the clavicle of 0.59. In Group 2, the average engagement length into the clavicle was 7.17 cm with a ratio of 0.47. The difference was significant, with the smaller pin providing better fixation. The pins in both groups perforated the lateral fragment at the posterosuperior aspect and the medial fragment at the anterior aspect of the clavicle. The angle that the pin made with the long axis of the clavicle in Group 1 was 22.43 degrees and in Group 2, 26.57 degrees. Although the 3.2 mm diameter pin was more aligned to the long axis of the clavicle than the 4 mm diameter pin, the difference was not significant.     

Circular frame fixation for calcaneal fractures risks injury to the medial neurovascular structures: A cadaveric description

AimThere is a risk of iatrogenic injury to the soft tissues of the calcaneus and this study assesses the risk of injury to these structures in circular frame calcaneal fracture fixation.Materials and methodsAfter olive tip wires were inserted, an L-shaped incision on the lateral and medial aspects of 5 formalin fixed cadaveric feet was performed to expose the underlying soft tissues. The calcaneus was divided into zones corresponding to high, medium and low risk using a grading system.ResultsStructures at high risk included the posterior tibial artery, posterior tibial vein and posterior tibial nerve on the medial aspect. Soft tissue structures on the lateral side that were shown to be at lower risk of injury were the small saphenous vein and the sural nerve and the tendons of fibularis longus and fibularis brevis.ConclusionThe lateral surface of the calcaneus provides a lower risk area for external fixation. The risk of injury to significant soft tissues using a circular frame fixation approach has been shown to be greater on the medial aspect.Clinical relevanceThis study highlights the relevant anatomical relations in circular frame fixation for calcaneal fractures to minimise damage to these structures.     

Morphometry of the human clavicle and intramedullary canal: A 3D,geometry‐based quantification

Midshaft clavicle fractures are a very common occurrence. The current treatment of choice involves internal fixation with superior or anterior clavicle plating, however their clinical success and particularly patient satisfaction are decreasing. The implementation of intramedullary devices is on the rise, but data describing the intramedullary canal parameters are lacking. The aim of this study is to quantify the geometry of the clavicle and its intramedullary canal, and to evaluate the effect of gender and anatomical side. This study used three‐dimensional image‐based models with novel and automated methods of standardization, normalization, and bone cross‐section evaluation. The data obtained in this study present intramedullary canal, and clavicle diameter and center deviation parameterized as a function of clavicle length as well as its radius of curvature and true length. Results showed that both right‐sided and female clavicles were shorter and thicker, but only females showed a statistically significant difference in size compared to males (p < 0.0001). The smallest clavicle and intramedullary canal diameters were seen at different clavicle lengths (45% and 52%), suggesting that the narrowest region of intramedullary canal cannot be appreciated based on external visualization of the clavicle alone. The narrowing of the intramedullary canal is of special interest because this is a potential limiting region for surgical planning and intramedullary device design. Furthermore, the location and value of maximum lateral curvature displacement is different in the intramedullary canal, implying there exists an eccentricity of the intramedullary canal center with respect to the clavicle center. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2191–2202, 2017.

     

Fracture pattern and fixation type related to loss of reduction in bicondylar tibial plateau fractures

IntroductionBicondylar tibial plateau fractures can be treated with locked plating applied from the lateral side with or without additional application of a medial plate (dual plating). Recent studies demonstrate that these injuries can be sub-grouped based upon their morphology by computed tomography (CT). The purpose of this study is to evaluate the relationship between fracture pattern, method of fixation and loss of reduction in bicondylar tibial plateau fractures.Patients and methodsPreoperative CT scans and postoperative plain films were evaluated on a consecutive series of bicondylar tibial plateau fractures. Fracture patterns were classified by CT. Angular alignment was measured immediately postoperatively and again at clinical and radiographic union to assess loss of reduction.ResultsA total of 140 patients were studied. Sixty-six (47%) had a single large medial fragment with the articular surface intact, 19 (14%) had a medial articular fracture line with a mainly sagittal component and 55 (39%) had a coronal fracture through the medial articular surface. A total of 129 patients had been treated with lateral locked plating alone whilst 11 patients (all with a coronal fracture of the medial condyle) underwent dual plating.There was little loss of reduction (median subsidence 0.5°) when lateral locked plating was employed alone in patients with a single medial fracture fragment or with a sagittal medial fracture line. When lateral locked plating was used in the presence of a medial coronal fracture line, there was a significantly higher rate of subsidence (median 2.0°) compared to those with no medial fracture line (p = 0.002). Patients with coronal fracture lines treated with dual plating had significantly less loss of reduction that those treated with lateral locked plating (p = 0.01).ConclusionsMost patients with bicondylar tibial plateau fractures do well when treated with lateral locked plating. However, those with a medial coronal fracture line tend to have a higher rate of subsidence and loss of reduction when lateral locked plating is employed alone. These fractures may be better treated with dual plating if the soft tissues allow.Level of evidenceLevel III (retrospective comparative study).     

Early dynamization by reduced fixation stiffness does not improve fracture healing in a rat femoral osteotomy model

Dynamization of fracture fixation is used clinically to improve the bone healing process. However, the effect of early dynamization remains controversial. This study evaluated the effect of early dynamization, by reduced stiffness of fixation on callus stiffness and size after 5 weeks of healing in a rat diaphyseal femoral osteotomy. An external unilateral fixator allowed either a rigid (R‐group; n = 8) or a flexible (F‐group; n = 8) fixation. The dynamized group (D‐group: n = 8) had a rigid fixation for 1 week, and then a flexible fixation for the remaining 4 weeks. The pre‐ and postoperative activity of the rats was measured. After 5 weeks, the rats were sacrificed, and healing was evaluated by biomechanical and densitometric methods. The R‐group had a higher activity more closely approaching preoperative levels, compared to the D‐group throughout all time points measured. This difference was significant after 14 days and 21 days. The flexural rigidity of the R‐group was 82% (tested in the anterior‐posterior direction; p = 0.01) and 93% (tested in the medial‐lateral direction; p = 0.002) greater than the flexural rigidity of the D‐group. The rigid fixation led to a stiffer callus with a smaller callus volume, but better mineralized tissue in the whole callus and at the level of the osteotomy gap than the flexible or the dynamized fixation. Early dynamization did not improve healing compared to rigid or flexible fixation in a rat femoral osteotomy model. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:22–27, 2009     

股骨外侧壁形态对股骨转子区骨折内固定失效的预测研究

目的：探讨外侧壁形态与股骨转子区骨折早期内固定失效的关系。方法：选取2015年1月至2020年1月行内固定治疗的295例股骨转子区骨折患者,根据术后是否出现早期内固定失败将患者分为两组,即失败组19例和正常组276例。对两组患者性别、患侧、年龄、AO分型、身体质量指数（body mass index,BMI）、术前血红蛋白、X线测量下外侧壁厚度、术前合并内科疾病、术中失血量、术后尖顶距（tip apex distance,TAD）、术后颈干角、手术时间等资料进行比较。比较两组外侧壁形态,对外侧壁形态与股骨转子区骨折早期内固失效进行相关性分析。结果：两组患者术后随访1年以上。两组患者在术中失血量、手术时间、术后TAD、术后颈干角等方面比较,差异无统计学意义（P>0.05）。末次随访失败组视觉模拟评分（visual anague scale,VAS）高于正常组（P<0.01）,失败组Harris评分小于正常组（P<0.05）。绘制外侧壁形态与股骨转子区骨折早期内固定失败之间的受试者工作特征（receiver operator characteristic,ROC）曲线,中...     

Combined Medial and Lateral Approach Versus Paratricipital Approach in Open Reduction and Internal Fixation for Type C Distal Humerus Fracture: A Randomized Controlled Study

Objective

Olecranon osteotomy and paratricipital approaches were widely used in the treatment of type C distal humerus fracture but some disadvantages exist, so a combined medial and lateral approach was designed. The objective of this study was to investigate and compare the clinical outcomes of combined medial and lateral approach with the paratricipital approach in open reduction and internal fixation of type C distal humerus fractures.

Methods

From May 2018 to April 2020, 37 patients with type C distal humerus fracture who accepted open reduction and internal fixation in our hospital were enrolled in this study. All cases were randomly divided into two groups according to the surgical approach: combined medial and lateral approach group (19 cases), paratricipital approach group (18 cases). All of the patients received open reduction and double vertical plates fixation. The operation and follow-up indexes, including operation time, blood loss, incision length, triceps muscle strength, flexion-extension arc of elbow and forearm rotation arc, were recorded and compared. Caja score was used to assess the quality of fractures reduction. Mayo Elbow Performance Score (MEPS) was used to evaluate the elbow function in the follow-up. Complications such as incision infection, ulnar nerve injury, degenerative osteoarthritis, and heterotopic ossification were analyzed.

Results

The differences in age, gender, and AO classification of fractures between two groups were not statistically significant (p > 0.05). The sum of medial and lateral incision length of combined approach group was longer than the midline incision of paratricipital approach group (15.4 ± 0.8 vs. 14.6 ± 0.8, p < 0.05), but there was no significant difference in operation time (103.5 ± 10.2 vs. 106.0 ± 8.8, p > 0.05), blood loss (71.3 ± 24.5 vs. 72.8 ± 24.6, p > 0.05), and Caja score (16.05 ± 5.67 vs. 15.56 ± 5.66, p > 0.05). During the follow-up, the MEPS of combined approach group was higher than that of paratricipital approach group at 3 months postoperatively (80.5 ± 5.7 vs. 68.9 ± 8.1, p < 0.05), but there was no significant difference in MEPS at 6 months postoperatively (83.9 ± 6.6 vs. 79.7 ± 7.0, p > 0.05) and at the last follow-up (86.8 ± 7.1 vs. 86.9 ± 7.7, p > 0.05) between the two groups. There was no significant difference in triceps muscle strength (p > 0.05), flexion-extension arc (126.8 ± 5.3 vs. 128.9 ± 6.0, p > 0.05), and forearm rotation arc (163.2 ± 5.3 vs. 163.6 ± 4.8, p > 0.05) at the last follow-up. Although the incidence of complication of combined approach group (15.8%) was lower than that of paratricipital approach group (22.2%), the difference was not statistically significant (p > 0.05).

Conclusions

The combined medial and lateral approach was an effective and safe way of open reduction and internal fixation for type C distal humerus fractures. Compared with the paratricipital approach, the combined medial and lateral approach could restore the elbow function more quickly postoperatively, and the long-term results were comparable.     

Osteosynthese dislozierter intraartikulärer Kalkaneusfrakturen

Objective

Anatomic reduction of displaced intra-articular calcaneal fractures with restoration of height, length, and axial alignment and reconstruction of the subtalar and calcaneocuboid joints.

Indications

Displaced intra-articular calcaneal fractures with incongruity of the posterior facet of the subtalar joint, loss of height, and axial malalignment.

Contraindications

High perioperative risk, soft tissue infection, advanced peripheral arterial disease (stage III), neurogenic osteoarthropathy, poor patient compliance (e. g., substance abuse).

Surgical technique

Extended lateral approach with the patient placed on the uninjured side. Reduction of the anatomic shape and joint surfaces according to the preoperative CT-based planning. Reduction of the medial wall and step-wise reconstruction of the posterior facet from medial to lateral. Reduction of the tuberosity and anterior process fragments to the posterior joint block and temporary fixation with Kirschner wires. Internal fixation with an anatomic lateral plate in a locking or nonlocking mode. Alternatively less invasive internal fixation with a calcaneus nail over a sinus tarsi approach for less severe fracture types.

Postoperative management

The lower leg is immobilized in a brace until the wound is healed. Range of motion exercises of the ankle and subtalar joints are initiated on the second postoperative day. Patients are mobilized in their own shoe with partial weight bearing of 20 kg for 6–12 weeks depending on fracture severity and bone quality.

Results

Over a 4-year period, 163 patients with 184 displaced, intra-articular calcaneal fractures were treated with a lateral plate via an extended approach. In all, 102 patients with 116 fractures were followed for a mean of 8 years. A surgical revision was necessary in 4 cases (3.4?%) of postoperative hematoma, 2 (1.7?%) superficial and 5 (4.3?%) deep infections. Of the latter, 2 patients needed a free flap for definite wound coverage, no calcanectomy or amputation was needed. Secondary subtalar fusion for symptomatic posttraumatic arthritis was performed in 9 cases (7.8?%). At follow-up, the AOFAS Ankle/Hindfoot Score averaged 70.2, the Zwipp Score averaged 76.0, the German versions of the Foot Function Index and SF-36 physical component averaged 32.8 and 42.2, respectively. Scores were significantly lower with increasing fracture severity according to the Sanders and Zwipp classifications, bilateral fractures, open fractures, and with work-related injuries. With less invasive fixation using a calcaneal nail, superficial wound edge necrosis was seen in 2 of 75 cases (2.7%).     

Comparison of Medial Malleolar Fracture Healing at 8 Weeks After Open Reduction Internal Fixation Versus Percutaneous Fixation: A Retrospective Cohort Study

Unstable medial malleolar fractures are treated with either standard open reduction internal fixation (ORIF) or a percutaneous approach. The percutaneous approach avoids the potentially excessive soft tissue dissection associated with an open approach but can also result in inadequate anatomic reduction. No studies have compared the incidence of radiographic healing of medial malleolar fractures between an open approach and percutaneous fixation. A retrospective comparative study was performed at a single institution across multiple sites. Electronic medical records and digital radiographs were reviewed for 845 patients who had undergone either ORIF or percutaneous screw fixation (PSF) of a medial malleolar fracture. The interval to fracture healing was measured. Logistic regression analysis was used. Of the 490 included patients, 458 (93.44%) underwent standard ORIF and 32 (6.53%) underwent PSF. Patients who underwent ORIF were 5 times more likely to have a healed fracture at 8 weeks than were patients who had undergone PSF (p < .001). Compared with standard ORIF, PSF of medial malleolar fractures leads to an increased risk of an unhealed fracture at 8 weeks. This was likely due to a combination of soft tissue interposition within the fracture site and inadequate fluoroscopic reliability, leading to poor anatomic reduction and inaccurate fixation.     

Radiographic effects observed in the coronal view after medial malleolar osteotomy at total ankle arthroplasty in rheumatoid arthritis cases

BackgroundWhen soft tissue balance is not acceptable at total ankle arthroplasty (TAA) for rheumatoid varus deformity, medial malleolar osteotomy has been performed. At the same time, the shape of the ankle joint changes after soft tissue balancing with such an osteotomy, however there is few information for the radiographic findings after the osteotomy. Thus, radiographic changes in the coronal view of such cases were investigated.MethodsJSSF-RA foot and ankle scale and SAFE-Q scores were determined along with pre/postoperative radiographic parameters of the ankle joint in 70 ankles (65 patients) with rheumatoid arthritis followed for a mean of 7.9 years (range, 2–16 years) after TAA. Seven ankles were excluded because those underwent lateral or lateral/medial malleolar osteotomy. Twenty-seven ankles underwent medial malleolar osteotomy, and compared with 36 ankles without osteotomy.ResultsAll ankles achieved bone union after medial malleolar osteotomy, and the tibial medial malleolus (TMM) angle was significantly decreased [30.3°–19.1°] following significant valgus correction [TC angle: −2.7° to 0.5°]. The gap due to medial soft tissue tightness was significantly improved by medial malleolar osteotomy [4.95° to 0.7°]. Lateral malleolar fractures sometimes occurred (19%: 5/27 ankles) at valgus correction, but they healed completely without any internal fixation.ConclusionMedial malleolar osteotomy was useful in rheumatoid varus ankle for not only controlling the soft tissue balance, but also providing a stabilized shape of the ankle joint. Lateral malleolar fractures were caused by valgus correction following medial malleolar osteotomy in some cases, but all fractures were completely healed without any internal fixation.     

自制髓内钉固定锁骨骨折的基础研究

[目的] 测量、研究锁骨的解剖学特征,研制一种带锁髓内钉固定锁骨中段骨折,探讨其优缺点.[方法] 通过对60根成人锁骨及5具成人新鲜尸体标本的测量、实验,测量锁骨长度,外侧段与中段夹角、中段与内侧段夹角,锁骨最窄处直径,锁骨最窄处髓腔内径等数据.设计出带锁髓内钉,采用髓内穿钉、髓外锁定的方法固定锁骨中段骨折.[结果] 锁骨全长为(14.82±1.15)cm,外侧段与中段夹角、中段与内侧段夹角均为30.左右,锁骨最窄处直径为(1±0.16)cm,锁骨最窄处髓腔内径为(0.5±0.18)cm.由锁骨中段骨折端逆行穿导针并扩髓,根据锁骨的形状适度折弯髓内钉,由近端或远端插入髓腔,分别锁定远、近端,固定稳定可靠.[结论] 自制带锁髓内钉固定锁骨中段骨折,手术创伤小、直视下复位满意而且固定可靠.但相关生物力学数据还有待于进一步研究.     

Nonunion of a medial malleolar stress fracture in an adolescent athlete secondary to lateral ankle instability: A case report

IntroductionMedial malleolar stress fractures are relatively uncommon. This report describes the successful treatment of nonunion of a medial malleolar stress fracture due to chronic lateral ankle instability.Presentation of caseA 13-year-old middle school student who belonged to a football club presented to our clinic with chronic medial left ankle pain lasting over a year. He had sprained his left ankle several times 6 years earlier. A plain anteroposterior ankle radiograph showed a vertical fracture line in the medial malleolus involving the epiphyseal plate, and computed tomography demonstrated the vertical fracture seen on the plain radiographs and bone sclerosis at the fracture site. We performed internal fixation for nonunion of the medial malleolar stress fracture with arthroscopic modified Broström for lateral ankle instability. Two years after surgery, the Self-Administered Foot Evaluation Questionnaire improved in all parameters, and both the anterior drawer and varus stress tests were negative.DiscussionEarly diagnosis of medial malleolar stress fracture is important for a rapid return to sports. Magnetic resonance imaging is helpful for early diagnosis. Because lateral ankle instability can cause medial malleolar stress fracture, arthroscopic modified Broström procedure is meaningful for medial malleolar stress fracture with lateral ankle instability.ConclusionInternal fixation and the arthroscopic modified Broström procedure could achieve good clinical outcomes for medial malleolar stress fractures with lateral ankle instability.     

Osteosynthese einer bikondylären Tibiakopffraktur in Bauchlage

Objective

The aim of the surgical treatment of intra-articular bicondylar tibial plateau fractures is the anatomical reconstruction and direct biomechanical optimal fixation of the fractured articular surface and the leg axis, taking the frequently associated soft tissue damage into account.

Indications

This article presents a cadaver model of a simulated complex bicondylar tibial plateau fracture 41C3 according to the AO classification with fracture involvement of all 10 segments and indications for surgery due to a posteromedial shearing fracture and lateral articular destruction with posterolaterocentral impaction.

Contraindications

Pronounced soft tissue damage with acute or incompletely healed infections in the area of the surgical approach.

Surgical technique

In the presented video of the operation, which is available online, the direct treatment of an intra-articular complex tibial plateau fracture from dorsal in a prone position is shown in detail: posterolateral ca. 13?cm long skin incision immediately above the fibular head with subsequent gentle preparation of the peroneal nerve at the medial border of the biceps femoris muscle. Retraction of the lateral head of the gastrocnemius muscle medially. Proximal detachment of the soleus muscle from the fibular head and retraction of the popliteus muscle medially. Horizontal capsule incision for fracture visualization. Opening of the lateral window ventral to the lateral collateral ligament. If necessary, osteotomy of the lateral femoral epicondyle for improved posterolaterocentral fracture visualization. Angular stable osteosynthetic fixation. Posteromedial approach medial to the medial gastrocnemius head. Retraction of the medial head of the gastrocnemius muscle laterally, horizontal capsular incision with sparing of the semimembranosus muscle medially and posterior cruciate ligaments laterally, fracture reduction, fixation with posteromedial support plate, image converter control, wound closure.

Follow-up

Postoperative cooling and elevation of the operated limb. Depending on the fracture 6–10 weeks partial loading of maximum 20?kg. Prior to full load bearing clinical radiological follow-up checks to determine the bony consolidation and material positioning.

Results

This is an established and safe delivery strategy for complex fracture patterns with dorsally running fractures. The risk of intraoperative malreduction is low. Postoperative reduction losses depend on fracture, operation and especially patient-specific characteristics.

     

Active shape modeling of the hip in the prediction of incident hip fracture

The objective of this study was to evaluate right proximal femur shape as a risk factor for incident hip fracture using active shape modeling (ASM). A nested case‐control study of white women 65 years of age and older enrolled in the Study of Osteoporotic Fractures (SOF) was performed. Subjects (n = 168) were randomly selected from study participants who experienced hip fracture during the follow‐up period (mean 8.3 years). Controls (n = 231) had no fracture during follow‐up. Subjects with baseline radiographic hip osteoarthritis were excluded. ASM of digitized right hip radiographs generated 10 independent modes of variation in proximal femur shape that together accounted for 95% of the variance in proximal femur shape. The association of ASM modes with incident hip fracture was analyzed by logistic regression. Together, the 10 ASM modes demonstrated good discrimination of incident hip fracture. In models controlling for age and body mass index (BMI), the area under receiver operating characteristic (AUROC) curve for hip shape was 0.813, 95% confidence interval (CI) 0.771–0.854 compared with models containing femoral neck bone mineral density (AUROC = 0.675, 95% CI 0.620–0.730), intertrochanteric bone mineral density (AUROC = 0.645, 95% CI 0.589–0.701), femoral neck length (AUROC = 0.631, 95% CI 0.573–0.690), or femoral neck width (AUROC = 0.633, 95% CI 0.574–0.691). The accuracy of fracture discrimination was improved by combining ASM modes with femoral neck bone mineral density (AUROC = 0.835, 95% CI 0.795–0.875) or with intertrochanteric bone mineral density (AUROC = 0.834, 95% CI 0.794–0.875). Hips with positive standard deviations of ASM mode 4 had the highest risk of incident hip fracture (odds ratio = 2.48, 95% CI 1.68–3.31, p < .001). We conclude that variations in the relative size of the femoral head and neck are important determinants of incident hip fracture. The addition of hip shape to fracture‐prediction tools may improve the risk assessment for osteoporotic hip fractures. © 2011 American Society for Bone and Mineral Research.     

Opposite cortical fracture in high tibial osteotomy: lateral closing compared to the medial opening‐wedge technique

Background and purpose?The aim with high tibial valgus osteotomy (HTO) is to correct the mechanical axis in medial compartmental osteoarthritis of the knee. Loss of operative correction may threaten the long‐term outcome. In both a lateral closing‐wedge procedure and a medial opening‐wedge procedure, the opposite cortex of the tibia is usually not osteotomized, leaving 1 cm of bone intact as fulcrum. A fracture of this cortex may, however, lead to loss of correction; this was examined in the present study.

Patients and methods?We used a prospective cohort of 92 consecutive patients previously reported by Brouwer et al. (). The goal in that randomized controlled trial, was to achieve a correction of 4 degrees in excess of physiological valgus. In retrospect, we evaluated the 1‐year radiographic effect of opposite cortical fracture. Opposite cortical fracture was identified on the postero‐anterior radiographs in supine position on the first day after surgery.

Results?44 patients with a closing‐wedge HTO (staples and cast fixation) and 43 patients with an opening‐wedge HTO (non‐angular‐stable plate fixation) were used for analysis. 36 patients (four‐fifths) in the closing‐wedge group and 15 patients (one‐third) in the opening‐wedge group had an opposite cortical fracture (p < 0.001). At 1 year, the closing‐wedge group with opposite cortical fracture had a valgus position with a mean HKA angle of 3.2 (SD 3.5) degrees of valgus. However, the opening‐wedge group with disruption of the opposite cortex achieved varus malalignment with a mean HKA angle of 0.9 (SD 6.6) degrees of varus.

Interpretation?Fracture of the opposite cortex is more common for the lateral closing wedge technique. Medial cortex disruption has no major consequences, however, and does not generally lead to malalignment. Lateral cortex fracture in the medial opening‐wedge technique, with the use of a non‐angular stable plate, leads more often to varus malalignment.     

Pediatric obesity and walking duration increase medial tibiofemoral compartment contact forces

With the high prevalence of pediatric obesity there is a need for structured physical activity during childhood. However, altered tibiofemoral loading during physical activity in obese children likely contribute to their increased risk of orthopedic disorders of the knee. The goal of this study was to determine the effects of pediatric obesity and walking duration on medial and lateral tibiofemoral contact forces. We collected experimental biomechanics data during treadmill walking at 1 m?s^?1 for 20 min in 10 obese and 10 healthy‐weight 8–12 year‐olds. We created subject‐specific musculoskeletal models using radiographic measures of tibiofemoral alignment and centers‐of‐pressure, and predicted medial and lateral tibiofemoral contact forces at the beginning and end of each trial. Obesity and walking duration affected tibiofemoral loading. At the beginning of the trail, the average percent of the total load passing through the medial compartment during stance was 85% in the obese children and 63% in the healthy‐weight children; at the end of the trial, the medial distribution was 90% in the obese children and 72% in the healthy‐weight children. Medial compartment loading rates were 1.78 times greater in the obese participants. The medial compartment loading rate increased 17% in both groups at the end compared to the beginning of the trial (p = 0.001). We found a strong linear relationship between body‐fat percentage and the medial‐lateral load distribution (r² = 0.79). Altered tibiofemoral loading during walking in obese children may contribute to their increased risk of knee pain and pathology. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:97–105, 2016.

     

69例踝部骨折手术治疗

目的：总结应用内踝外踝纵行切口,内固定治疗踝关节骨折的经验。方法：对69例踝关节骨折用内踝外踝纵行切口手术路径内固定治疗。结果：62例随访6月～3年,根据苟三怀提出的标准,优39例,良16例,优良率88.7%。结果：踝关节骨折内外侧路径安全,易行,坚强内固定有利关节功能恢复。     

胫骨平台后髁骨折的治疗

目的:探讨胫骨平台后髁骨折的治疗方法。方法:9例胫骨平台后髁骨折患者,男6例,女3例;年龄24⁵8岁,平均36岁。左侧2例,右侧7例。骨折类型:后外侧髁骨折5例,后内侧髁骨折1例,双髁骨折3例,采用后内和（或）后外侧入路复位内固定治疗。结果:9例均获随访,随访时间6³2个月,平均18·4个月。患膝关节功能评定按Hohl评分标准:优7例,良2例。关节面未见明显塌陷情况。结论:膝关节的后内和（或）外侧入路较前侧入路能更充分暴露后关节间隙及胫骨平台后髁,为骨折的直视复位和植骨内固定提供了良好的操作空间。