Vascular implications of minimally invasive plating of proximal humerus fractures

OBJECTIVES: Open reduction and internal fixation of proximal humerus fractures through the anterolateral acromial approach, which uses the anterior deltoid raphe and axillary nerve protection, has recently been advocated as a minimally invasive technique. Several recent reports have indicated variable and unpredictable vascular injuries to the humeral-head blood supply after a proximal humerus fracture, and thus a direct approach that minimizes further vascular compromise may be preferable. The purpose of this study was to define the relationship of this surgical interval to the lateral plating zone of the proximal humerus and to the penetrating vascular supply of the humeral head. DESIGN: Cadaveric vascular injection study. SETTING: Cadaveric dissection laboratory. PATIENTS: Six cadaveric specimens. INTERVENTION: The anterolateral acromial approach was performed on six cadaveric upper-extremity specimens. A locking proximal humerus plate was applied to the lateral proximal humerus, and the axillary artery was cannulated proximal to the circumflex humeral arteries. Dyed latex polymer was injected and allowed to harden, and dissection was performed to visualize the vasculature of the proximal humerus. Plates were then removed and the specimens were further inspected to examine the blood supply. MAIN OUTCOME MEASUREMENTS: The relationship of the anterolateral acromial approach to the lateral plating zone of the proximal humerus and the vascular supply of the humeral head. RESULTS: In all specimens, the filling of the anterior and posterior vessels that supplied the humeral head were undisturbed after use of the anterolateral acromial approach and locked plating. The blood vessels to the head-penetrating vascular branches were not in the surgical field. A bare spot on the lateral proximal humerus existed in the region of the greater tuberosity, which was 30 mm wide and between two penetrating humeral-head epiphyseal vessels. The nearest penetrating vessels were close to the plate, 4 mm anterior and 7 mm posterior. The anterior humeral circumflex vessel and its ascending branch, which provides critical blood supply to the humeral head, coursed directly in the region of the deltopectoral approach. CONCLUSIONS: Minimally invasive techniques have many potential benefits for fracture healing, but new surgical approaches often must be used to take full advantage of these newer methods. Splitting the anterior deltoid raphe from the acromion distally allowed direct access to the lateral plating zone of the proximal humerus. The bare spot in this region may be a safe area for plate application, if the plate is placed appropriately with thorough knowledge of the vascular anatomy. These findings may be of particular importance if the vascular supply to the humeral head has already been partially compromised by preceding trauma. This direct approach to the lateral bare spot on the proximal humerus may minimize iatrogenic vascular injury when treating these fractures.     

The importance of medial support in locked plating of proximal humerus fractures

OBJECTIVES: The purpose of this study was to determine what factors influence the maintenance of fracture reduction after locked plating of proximal humerus fractures, and particularly the role of medial column support. SETTING: University medical center. INTERVENTION: Thirty-five patients who underwent locked plating for a proximal humerus fracture were followed up until healing. For the initial and final radiographs, 2 lines were drawn perpendicular to the shaft of the plate, one at the top of the plate and one at the top of the humeral head, and the distance between them was measured as an indicator of loss of reduction. Medial support was considered to be present if the medial cortex was anatomically reduced, if the proximal fragment was impacted laterally in the distal shaft fragment, or if an oblique locking screw was positioned inferomedially in the proximal humeral head fragment. MAIN OUTCOME MEASUREMENTS: Multivariate linear regressions were performed to determine the effects that age, sex, fracture type, cement augmentation, and medial support had on loss of reduction. RESULTS: The presence of medial support had a significant effect on the magnitude of subsequent reduction loss (P < 0.001). Age, sex, fracture type, or cement augmentation had no effect on maintenance of reduction. Eighteen patients were determined to have adequate mechanical medial support (+MS group), and the remaining 17 patients did not have medial support (-MS group). In the +MS group, the average loss of humeral head height was 1.2 mm, and 1 case of articular screw penetration occurred that required removal. In the -MS group (without an appropriately placed inferomedial oblique screw and either nonanatomic humeral head malreduction with lateral displacement of the shaft or medial comminution), loss of humeral height averaged 5.8 mm (P < 0.001). There were 5 cases in this group in which screw penetration of the articular surface occurred (P = 0.02), 2 of which required reoperation for removal. All fractures in both groups healed without delay, and none required revision to arthroplasty. CONCLUSIONS: Achieving mechanical support of the inferomedial region of the proximal humerus seems to be important for maintaining fracture reduction. Locked plates in general do not appear to be a panacea for these fractures and are unable to support the humeral head alone from a lateral tension-band position. However, there are several factors that are in the surgeon's control that may improve the mechanical environment. Achieving an anatomic or slightly impacted stable reduction, as well as meticulously placing a superiorly directed oblique locked screw in the inferomedial region of the proximal fragment, may achieve more stable medial column support and allow for better maintenance of reduction.     

Vaskularisation des Humerus

The proximal third of the humerus is fed by the anterior and posterior circumflex arteries of the axillary artery. They construct a fine anastomoses network at the humeral head as well as longitudinal anastomoses to the diaphysis. The middle third of the humerus is maintained by the rami musculoperiostales originating in both the brachial artery and the deep brachial artery. These periosteal vessels are formed both horizontally and vertically. The distal third of the humerus is mainly supplied by the horizontal anastomoses of the collateral arteries. The inner part of the bone is normally penetrated by just one nutrient artery entering the nutrient canal below the middle of the humerus.     

Multifocal humeral fractures

Introduction

Multifocal humeral fractures are extremely rare. These may affect the neck and the shaft, the shaft alone, or the diaphysis and the distal humerus. There is no classification of these fractures in the literature.

Materials and methods

From 2004 to 2010, 717 patients with humeral fracture were treated surgically at our department. Thirty-five patients presented with an associated fracture of the proximal and diaphyseal humerus: synthesis was performed with plate and screws in 34 patients, and the remaining patient had an open fracture that was treated with an external fixator.

Results

Mean follow-up was 3 years and 3 months. A classification is proposed in which type A fractures are those affecting the proximal and the humeral shaft, type B the diaphysis alone, and type C the diaphysis in association with the distal humerus. Type A fractures are then divided into three subgroups: A-I, undisplaced fracture of the proximal humerus and displaced shaft fracture; A-II: displaced fracture of the proximal and humeral shaft; and A-III: multifragmentary fracture affecting the proximal humerus and extending to the diaphysis.

Discussion

Multifocal humeral fractures are very rare and little described in the literature, both for classification and treatment. The AO classification describes bifocal fracture of the humeral diaphysis, type B and C. The classification suggested in this article mainly concerns fractures involving the proximal and humeral shaft.

Conclusions

A simple classification of multifocal fractures is suggested to help the surgeon choose the most suitable type of synthesis for surgical treatment.     

肱骨近端关节囊内骨折的预后判断标准

目的 分析肱骨近端关节囊内骨折原始X线片表现与预后的关系，为选择治疗方案提供依据。方法 1999年4月至2004年2月保守治疗肱骨近端关节囊内骨折459例，其中资料完整、随访时间大于9个月者211例，男82例，女129例；年龄17～81岁，平均54．2岁。Neer一部分骨折68例，二部分骨折39例，三部分骨折59例，四部分骨折45例。将原始X线片与随访9个月以上的X线片进行比较，按照自行设计的评估标准：Neer分型、骨折近端内侧干骺端长度、肱骨头相对肱骨干的位移、大转子相对肱骨干的位移、骨折内侧皮质的位移、肱骨头是否脱位、肱骨头是否劈裂，分析其与预后的关系，以及各个标准对预后判断的准确程度。结果 79％的骨折近端内侧干骺端长度小于8mm的骨折、84％的内侧皮质位移大于2mm的骨折及68％的Neer四部分骨折预后不良。对于预后不良预测准确度最高的指标依次为骨折内侧皮质的位移大于2mm（准确度0．85）、骨折近端内侧干骺端长度小于8mm（准确度0．83）、Neer四部分骨折（准确度0．76），而头脱位（准确度0．64）、头劈裂（准确度0．64）、肱骨头相对肱骨干的位移大于10mm（准确度0．54）的预测准确度较差。结论 新的评估标准可为肱骨近端关节囊内骨折提供精确的预后判断，从而为治疗方案的选择提供依据。     

Predicting failure after surgical fixation of proximal humerus fractures

Background

Several studies reported high failures rates after internal fixation of proximal humerus fractures. Loss of reduction and screw cut-out are the most common reasons for revision surgery. Several risk factors for failure have been described in the literature. The aim of the present study was to assess risk factors for failure after surgical fixation of unstable proximal humerus fractures in a multivariate setup.

Methods

Two different surgical techniques (PHILOS locking plate and Humerusblock) were used. In the PHILOS group, every kind of postoperative relative movement between the implant and the humeral head or shaft was defined as failure. In the Humerusblock group, postoperative movement between the humeral head and the shaft in terms of angulation or translational displacement was defined as failure. The following parameters were assessed: age, gender, cancellous bone mineral density (BMD) of the humeral head, fracture type, medial metaphyseal comminution, medial metaphyseal head extension, initial angulation of the humeral head in the frontal plane, initial anteversion of the humeral head, medial hinge displacement, maximum displacement of the tuberosities with respect to the head, surgical technique, anatomic reconstruction and restoration of the medial cortical support.

Results

The following parameters were found to have a significant influence on the failure rate: age, local BMD, anatomic reduction, and restoration of the medial cortical support. The failure rate significantly increased with the number of risk factors.

Conclusion

Preoperative assessment of the local BMD and the patients’ biological age as well as intraoperative anatomic reduction and restoration of the medial cortical support are the essentials for successful surgical fixation of proximal humerus fractures. Multifragmentary fracture patterns in old patients with low local BMD are prone for fixation failure. If the surgeon is not able to achieve anatomic reduction and restoration of the medial cortical support intraoperatively in this situation, adjustments such as augmentation or primary arthroplasty should be considered.     

微创三切口技术治疗累及远端的肱骨中下段骨折

目的 探讨微创三切口双钢板固定技术治疗累及肱骨远端特别是肱骨远端、关节面的肱骨干中下段骨折的疗效.方法 2004年9月至2007年11月共收治6例累及肱骨远端的肱骨干中下段骨折患者,经肘关节内侧切口复位关节内骨折,空心螺钉固定.肱骨远端与骨干复位后,内侧柱用1/3管型钢板固定.肱骨干骨折采用闭合复位,于上臂前侧三角肌和肱二头肌之间另做小切口,制备此小切口与肘关节外侧切口之间的肌下隧道.将塑形的4.5 mm动力加压钢板经上臂小切口肌下插入,至肘关节外侧切口.钢板近端置于肱骨于前缘,远端置于外侧柱前外侧面,各至少3枚螺钉固定.术后采用Mayo肘关节功能评分系统评价结果.结果 6例患者术后获13～36个月(平均22.2个月)随访.骨折均获愈合,愈合时间为12～24周(平均19周).无医源性桡神经麻痹及内固定失败病例发生.肘关节活动度为110°～140°,平均130.8°.根据Mayo肘关节评分标准评定疗效:全部为优.结论 采用微创三切口双钢板技术治疗累及肱骨远端关节面的肱骨中下段骨折操作简单,可获得满意效果.     

肱骨近端"头帽型"骨折的解剖学特点及诊疗方案研究

目的探索适合肱骨近端特殊类型的"头帽型"骨折的诊疗方案，降低术后并发症的发生率。 方法根据骨折的影像学分型、解剖学特点及术后并发症的发生率，结合北京大学人民医院创伤骨科2016年1月至2017年12月诊治的肱骨近端"头帽型"骨折患者18例诊疗结果，研究肱骨近端"头帽型"骨折的诊疗特殊性。 结果符合肱骨近端"头帽型"骨折分型的18例中9例采取切开复位钢板内固定手术治疗，有2例（22%）出现了不同程度的肱骨头吸收、肱骨头骨块厚度变薄和预后肩关节活动功能差；而采取人工关节置换术的9例未出现预后肩关节活动受限等并发症。 结论"头帽型"骨折术后发生肱骨头坏死、畸形愈合等风险高，应高度重视该骨折类型固定的特殊性。     

Nonunion of the humeral shaft: long lateral butterfly fracture--a nonunion predictive pattern?

Retrospective review of 30 patients with nonunion of the humeral shaft treated from 1984-1999 revealed nine patients with an initial fracture pattern which to our knowledge was not described previously. Humeral fractures originated at the junction of the proximal and middle thirds of the diaphysis as an hemitransverse medial fracture that extended with a great lateral butterfly third fragment with its distal portion long and sharp. The patients were women approximately 60 years old. Eight fractures progressed to nonunion after initial conservative treatment. All fractures followed the same pattern: the proximal humeral fragment healed with the proximal portion of the third fragment, but an atrophic nonunion between the proximal humeral fragment, the distal humeral fragment, and the distal portion of the third fragment developed. The treatment required a technique adapted to this type of nonunion consisting of retrograde flexible intramedullary nailing, cerclage wires, and bone grafts.     

Therapie der Humerusschaftfraktur

Fractures of the humeral shaft are less frequent than those of the proximal humerus. The formerly recommended treatment of humeral shaft fractures was conservative according to B?hler. This still remains an adequate concept of treatment but according to a change in the technical possibilities and the demands of patients and physicians on fast restoration of function and low pain, there is a trend towards surgical stabilization of humeral shaft fractures. The implant of choice is discussed controversially and consists of various types of nails versus plating. The technique of nailing is antegrade or retrograde and depends on the localization of the fracture. In our opinion good indications for plating are combined fractures of the proximal humerus and the shaft as well as very distal humeral shaft fractures. A primary lesion of the radial nerve is no imperative indication for exploration and different studies have shown the same results for exploration after 2 or 3 months if there is no spontaneous remission.     

Die winkelstabile Plattenosteosynthese bei Frakturen am proximalen Humerus mit der LPHP (Locking Proximal Humerus Plate)

OBJECTIVE: Stable fixation of unstable proximal humerus fractures until bony consolidation. Early mobilization of the shoulder and early active rehabilitation program to ensure a good functional outcome and a good restoration of the activities of daily living. INDICATIONS: Unstable two-, three- and four-part fractures of the proximal humerus (classified according to the AO classification as: 11-A2, A3, B1, B2, B3, C1, C2, C3). Nonunions of the proximal humerus, especially at the neck. Pathologic fractures of the proximal humerus. CONTRAINDICATIONS: Comminuted humeral head fractures in old patients, which cannot be reconstructed adequately. Proximal humerus fractures in the immature patient. Local infection after previous surgery. SURGICAL TECHNIQUE: Deltopectoral approach. Blunt mobilization of the deltoid muscle. Suture loops through the supraspinatus tendon, the infraspinatus tendon, and the subscapularis tendon close to their bony insertion. Careful indirect reduction of the fracture fragments without further damage to their blood supply. Correct positioning of the LPHP (Locking Proximal Humerus Plate) on the lateral side of the humerus, approximately 5 mm below the tip of the greater tuberosity. Indirect approximation of the subcapital fracture component to the plate, by tightening a standard 3.5-mm cortical bone screw inserted into the first hole distal to the metaphyseal fracture line. Temporary fixation of the plate with 1.8-mm Kirschner wires. Fixed-angle fixation of the plate to the bone, using locking screws. Additional stabilization of the tuberosities to the plate with suture loops. RESULTS: Between January 1, 1997 and April 30, 2002, 64 patients with acute fractures of the proximal humerus were treated with fixed-angle plating at the UKH Graz. 36 patients meeting the inclusion criteria (that is primary operative stabilization within 14 days after trauma in a standardized way and minimal follow-up period of 12 months) were assessed 31 months after surgery on average, using the Constant Score and the DASH Score. The mean age of the 22 women and 14 men was 57.5 years (21-78 years). According to the AO classification eight fractures were classified as 11-A3, one fracture as B1, five fractures as B2, three fractures as B3, one fracture as C1, 16 fractures as C2, and two fractures as C3. A mean Constant Score of 62.6 points and an age-related Constant Score of 80.7% on average, as well as a DASH Score of 18.0 points were obtained, constituting a satisfactory result in three quarters of all patients. Complications observed were two humeral head necroses, one partial necrosis after a head-splitting fracture with nevertheless good clinical result, and a deep infection in two cases. Breakage of the plate was seen in one patient with an A3.3 fracture without medial buttress; no further surgery was necessary; the fracture healed after a short period of immobilization.     

吻合血管同种异体骨移植的解剖学研究

目的 为选用吻合血管同种异体骨移植的供区提供解剖学依据。方法 选用经动脉灌注红色乳胶的成人上、下肢标本各４０侧,着重对肱骨、桡骨、股骨和胫骨的滋养血管、进行观测;另选上述供骨区成人干燥骨各５０根,作滋养孔（或称管）观察。结果 肱骨上端有４～１２个滋养也,旋肱前、后动脉是其滋养血管主要来源;肱骨干滋养孔多位于肱骨中段前内侧面,滋养动脉多发自肱动脉;桡骨下端滋养血管主要由骨间前动脉及桡动脉供应;股骨干滋养１～３个,滋养动脉来自股深动脉的穿支;胫骨干滋养孔恒定位于胫骨中、上１／３段后面,滋养血管来自胫后动脉分支。结论 根据长骨大段骨缺损,选用在外形上与受区相匹配的供骨,上述血管长度、口径均适合显微外科的吻接要求。     

The significance of nerve damage in upper arm fractures

Lesions of the nerves are a relatively frequent complication after humeral shaft fractures, the nerve most commonly affected being the radial nerve. In the case of proximal fractures of the humerus, particularly dislocation fractures and luxated fractures, lesion of the axillary nerve and irritation of the plexus, are most frequent. In distal humeral fractures the ulnar nerve is most frequently first place and shows a serious complication. The therapy of the fracture must differ in most of these cases from conventional procedure. We believe that primary paresis of the radial nerve is a relative indication for surgery and secondary paresis of the radial nerve, an absolute indication for operation. When we find a subcapital humeral shaft fracture with rare paresis of the nervus axillaris we wait with an operation, but if remission does not occur within approximately 8 weeks a revision should be done. Fracture luxations with irritation of the plexus are an acute indication for operation, because repositioning or displacement of the head fragment can afford relief.     

The spiral compression plate for proximal humeral shaft nonunion: a case report and description of a new technique

We present a case of humeral nonunion managed with a dynamic compression plate (DCP) contoured in a spiral fashion to preserve the deltoid muscle insertion. A forty-one-year-old woman sustained a closed proximal third humeral shaft fracture with an associated supraclavicular brachial plexus injury. She presented five months later with an atrophic nonunion of the proximal humeral shaft, inferior subluxation of the humeral head, and a resolving brachial plexopathy. Autogenous cancellous bone grafting and open reduction and internal fixation with a narrow DCP was performed. The deltoid muscle insertion was preserved by contouring the plate to fix the proximal humerus laterally over the greater tuberosity and anteriorly over the mid-humeral shaft. During the postoperative period, the humeral head reduced spontaneously. Five months after surgery, the fracture healed, and an excellent clinical result was achieved. We recommend the use of the spiral DCP for proximal shaft fractures and nonunions when preservation of the deltoid insertion is desirable.     

Morphological Analysis of Fractures of the Proximal Humerus by the Fracture Mapping Technique

Objective

Fractures of different parts of the proximal humerus may lead to different postoperative functional deficits, but there are few studies on the morphology and related functions of the proximal humerus. The purpose of this study was to analyze the fracture pattern of the proximal humerus by the three-dimensional (3-D) fracture mapping technique and to further evaluate its clinical utility.

Methods

Patients with proximal humeral fractures admitted to Pudong Hospital, Fudan University, from January 2018 to December 2020, were analyzed. Three surgeons divided the fractures into groups according to the 3-D CT imaging technique and mapped the fractures on a 3-D template according to the fracture line of each fracture. Finally, the humeral head inversion angle and the functional score were recorded in different fracture types.

Results

A total of 312 cases of humeral fractures were included. Among them, there were 90 patients (28.8%) in the simple greater tuberosity + lesser tuberosity + medial cortex group, with typical fracture features of surgical neck fractures of the humerus + greater tuberosity fractures. Eighty-seven patients (27.9%) in the greater tuberosity + isolated fragment lesser tuberosity + medial cortex group had typical “four-part fractures.” There were 45 patients (14.4%) in the greater tuberosity + lesser tuberosity + medial isolated fragment group. Moreover, more patients in this group had medial comminution due to varus displacement of the femoral head. There were 66 patients (21.1%) in the isolated greater tuberosity group, 21 patients (6.7%) in the greater tuberosity + lesser tuberosity group, and three patients (1.0%) in the greater tuberosity + medial cortex group. In addition, the humeral head inversion angle and other statistical differences were observed in the greater tuberosity + lesser tuberosity + medial isolated fragment group.

Conclusions

This morphological study helps to further identify the characteristics of proximal humerus fracture patterns, which may be closely related to different clinical outcomes. Further relevant studies are needed to verify the reliability of their clinical application and the potential value in surgical planning and postoperative functional rehabilitation.     

Two-incision technique for treatment of complex proximal humerus fractures

The treatment of complex proximal humerus fractures that involve displacement of the greater tuberosity remains challenging. Good functional outcomes and decreased pain are possible with open reduction and internal fixation. Keys to a successful outcome include preservation of blood supply through decreased soft-tissue stripping, restoration of normal anatomic relationships (particularly the greater tuberosity), and stable internal fixation that allows early range of motion. To attain these goals, we advocate fixation with a fixed-angle locking proximal humerus plate using a 2-incision approach. A deltopectoral incision is used to expose the humeral shaft and head while the greater tuberosity is visualized by using a lateral incision. The fracture fragments are reduced and the plate is secured by working through these 2 incisions.     

Locking plate fixation for proximal humerus fractures

Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.     

Innovations in the management of displaced proximal humerus fractures

The management of displaced proximal humerus fractures has evolved toward humeral head preservation, with treatment decisions based on careful assessment of vascular status, bone quality, fracture pattern, degree of displacement, and patient age and activity level. The AO/ASIF fracture classification is helpful in guiding treatment and in stratifying the risk for associated disruption of the humeral head blood supply. Nonsurgical treatment consists of sling immobilization. For patients requiring surgery, options include closed reduction and percutaneous fixation; transosseous suture fixation; open reduction and internal fixation, with either conventional or locking plate fixation; bone graft; and hemiarthroplasty. Proximal humerus fractures must be evaluated on an individual basis, with treatment tailored according to patient and fracture characteristics.     

Posterior fracture-dislocation of the shoulder. A superior subacromial approach for open reduction.

We describe 11 cases of posterior fracture-dislocation of the shoulder that required open reduction and fixation. Difficulties with access through anterior approaches led us to use the superior subacromial approach. This is an extension of the approach often used to expose the rotator cuff; the joint is opened by splitting the supraspinatus tendon 5 mm behind the cuff interval. The glenoid, proximal humerus and any fracture fragments can be seen from above, allowing reduction of the dislocation and osteosynthesis to be performed with minimal risk of damage to the humeral head and its blood supply. The proximity of the axillary nerve limits the exposure of the proximal humeral shaft. The superior subacromial approach is ideal for posterior dislocation with fracture of the articular segment, but is not suitable when there is a fracture of the proximal humeral shaft.     

Extraosseous blood supply of the tibia and the effects of different plating techniques: a human cadaveric study

OBJECTIVE: To describe the extraosseous blood supply of the tibia and how the blood supply of the distal tibia is influenced by different plating techniques. DESIGN: Microdissection of cadaveric adult hip disarticulation specimens following sequential arterial injections of india ink and Ward's Blue Latex was performed. Readily identifiable arterioles measured approximately 0.5 mm in diameter. Their artery of origin was identified, and their position along the medial, lateral, and posterior aspects of the tibia was documented relative to the tibial plafond. Additionally, six matched pairs of limbs were used to assess the effects of different plating techniques on the extraosseous blood supply along the medial aspect of the distal tibia. SETTING: University anatomy laboratory. PATIENTS/PARTICIPANTS: Nine matched pairs ( = 18) of randomly obtained, adult cadaveric hip disarticulation specimens. INTERVENTION: India ink followed by Ward's Blue Latex was injected into the superficial femoral artery at the level of the inguinal crease after cleansing of the arterial system. The skin, subcutaneous tissue, and muscles were dissected from the leg, exposing the arterial system and the extraosseous vessels of the tibia. MEAN OUTCOME MEASUREMENTS: The extraosseous blood supply of each aspect of the tibial diaphysis was determined. Each extraosseous arteriole was identified, and the locations of each documented relative to the tibial plafond. Changes in the filling of these vessels along the medial aspect of the distal tibia were documented in a separate group of specimens ( = 12), which had undergone two different plating techniques. RESULTS: The proximal metaphysis of the tibia was found to have a rich extraosseous blood supply provided primarily from vessels from the popliteal artery, the anterior tibial artery (ATA) laterally, and the posterior tibial artery (PTA) medially. In comparison, the tibial diaphysis was found to have relatively few extraosseous vessels and a considerably hypovascular region, posteriorly. Branches of the ATA were found to supply the posterior aspect of the diaphysis with these branches passing through the interosseous membrane. The diaphysis also received a variable contribution from the PTA. The lateral aspect of the diaphysis was supplied by branches of the ATA. An anastomotic network of arteries from the ATA and PTA formed the rich extraosseous blood supply of the medial distal aspect of the tibia. Open plating of the medial aspect of the distal tibia caused a statistically significant ( < 0.05) greater disruption of the extraosseous blood supply of the metaphyseal region than did percutaneously applied plates. In each specimen, open plating prevented filling of each periosteal vessel in the region as opposed to percutaneous plates, which permitted filling of the extraosseous vessels up to the edge of the plate. CONCLUSIONS: The proximal and distal metaphyseal areas of the tibia have a rich extraosseous blood supply provided primarily by branches of the ATA and the PTA. Open plating of the medial aspect of the distal tibia caused a greater disruption of this extraosseous blood supply than did percutaneously applied plates. Disruption of these extraosseous vessels following fracture and subsequent operative stabilization may slow healing and increase the risk of delayed union and nonunion. These findings support current efforts to develop less invasive methods and implants for operative stabilization of distal tibia fractures.