Vascularity Of Head Research Articles

Surgical hip dislocation: techniques for success.

Surgical hip dislocation (SHD) is a versatile approach used to address both intra-articular and extra-articular pathology around the hip joint in both pediatric and adult patients. It allows anterior dislocation of the femoral head for direct visualization of the hip joint while preserving femoral head vascularity and minimizing trauma to the abductor musculature. Previously described indications for SHD include femoroacetabular impingement, deformity resulting from Legg-Calve-Perthes disease, slipped capital femoral epiphysis, periarticular trauma, benign lesions of the hip joint, and osteochondral lesions. In this review, we will describe current surgical techniques, indications, and clinical outcomes for SHD.

PET/CT study of temporal variations in blood flow to the femoral head following low-energy fracture of the femoral neck.

Earlier studies on femoral neck fractures have assessed the blood flow in either the pre- or postoperative period and information is lacking regarding changes in vascular flow to the femoral head after injury. Sixty-two adults with low-energy intracapsular femoral neck fractures were studied prospectively. Mean patient age was 57.2 years (range, 45-82 years). All patients underwent positron emission tomography/computed tomography (PET/CT) prior to surgical intervention and 6 weeks after internal fixation. Internal fixation was done using cannulated cancellous titanium screws and serial follow-up radiographs were obtained (at monthly intervals for the first 3 months followed by 3 monthly intervals between radiographs up to 2 years). On the preoperative PET/CT, 13 patients showed intact vascularity, 31 showed total loss of vascularity, and 18 showed partial loss of vascularity of the femoral head. The 6-week postoperative PET/CT scan showed recovery of blood supply in 23 of the 31 patients with total loss of vascularity and 15 of the 18 patients with partial loss of vascularity of the femoral head. Eleven of 62 patients had total or partial avascularity at the 6-week postoperative PET/CT scan and all 11 patients showed evidence of avascular necrosis on plain radiographs at the end of 2 years. The association between the vascular status of the femoral head at 6 weeks and avascular necrosis at the end of 2 years was statistically significant (P<.001). This study shows that the femoral head undergoes temporal variations in blood flow following femoral neck fracture. Decreased or absent vascularity is seen in approximately 75% of the fractures and 80% of the femoral heads with initial vascular compromise seem to regain blood flow within 6 weeks. Thus, prognostication about vascularity based on single-point preoperative imaging is difficult. The 6-week postoperative PET/CT scan seems to be reliable in predicting the future status of the femoral head. However, decision making regarding hemiarthroplasty or internal fixation at the time of injury may have to depend on factors other than the preoperative vascular status of the femoral head.

Survivorship of standard versus modified posterior surgical approaches in metal-on-metal hip resurfacing.

ObjectivesMetal-on-metal hip resurfacing (MOMHR) is available as an alternative option for younger, more active patients. There are failure modes that are unique to MOMHR, which include loosening of the femoral head and fractures of the femoral neck. Previous studies have speculated that changes in the vascularity of the femoral head may contribute to these failure modes. This study compares the survivorship between the standard posterior approach (SPA) and modified posterior approach (MPA) in MOMHR. MethodsA retrospective clinical outcomes study was performed examining 351 hips (279 male, 72 female) replaced with Birmingham Hip Resurfacing (BHR, Smith and Nephew, Memphis, Tennessee) in 313 patients with a pre-operative diagnosis of osteoarthritis. The mean follow-up period for the SPA group was 2.8 years (0.1 to 6.1) and for the MPA, 2.2 years (0.03 to 5.2); this difference in follow-up period was statistically significant (p < 0.01). Survival analysis was completed using the Kaplan–Meier method. ResultsAt four years, the Kaplan–Meier survival curve for the SPA was 97.2% and 99.4% for the MPA; this was statistically significant (log-rank; p = 0.036). There were eight failures in the SPA and two in the MPA. There was a 3.5% incidence of femoral head collapse or loosening in the SPA and 0.4% in the MPA, which represented a significant difference (p = 0.041). There was a 1.7% incidence of fractures of the femoral neck in the SPA and none in the MPA (p = 0.108). ConclusionThis study found a significant difference in survivorship at four years between the SPA and the MPA (p = 0.036). The clinical outcomes of this study suggest that preserving the vascularity of the femoral neck by using the MPA results in fewer vascular-related failures in MOMHRs.Cite this article: Bone Joint Res 2014;3:150–4

English

BACKGROUND: Posterior shoulder dislocations and fracture-dislocations are uncommon injuries that most often occur during seizures or as a result of high-energy trauma. Despite advances in imaging, they are frequently diagnosed late. Detection is facilitated by heightened clinical suspicion of the injury in high-risk individuals together with appropriate radiographic investigation. A wide variety of operative techniques, ranging from simple closed reduction to soft-tissue and bone stabilization procedures to prosthetic arthroplasty, are available to treat these injuries. Selection of the most appropriate treatment option is complex and multifactorial. Good functional outcomes are associated with early detection and treatment of isolated posterior dislocations that are associated with a small osseous defect and are stable following closed reduction. Poor prognostic factors include late diagnosis, a large anterior defect in the humeral head, four part fracture or arthrosis of the humeral head. CASE DESCRIPTION: A 24 year old male worker presented with persisting pain and stiffness in his right shoulder following high energy trauma 8 months back. Physical examination and radiological evidence showed posterior dislocation with humeral head fracture. Patient was treated by open reduction and reconstruction of the proximal humerus. Post operative follow up for 18 months showed good range of movements. Early diagnosis and treatment of this rare type can prevent deformities. INTRODUCTION: Posterior locked shoulder dislocation is an uncommon injury (2–4% of all shoulder dislocations) which may be misdiagnosed and overlooked in up to 60% of cases.1 The spectrum of associated injuries varies from the isolated impaction fracture of the anteromedial aspect of the humeral head (reverse Hill-Sachs lesion) to more complex fracture types of the proximal humerus (less than 1%) and shoulder girdle 1, 2. The unrecognized dislocation-fracture pattern can jeopardize the joint mobility and the vascularity of the humeral head predisposing to chronic instability, osteonecrosis and osteoarthritis .1 The management of posterior fracture dislocation after delayed diagnosis is complicated.3 CASE PRESENTATION: A 24-year-old right-hand dominant male worker, presented at the Vydehi Hospital complaining of persisting pain and stiffness in his right shoulder. The symptoms began 8 months earlier following a high energy trauma. The patient reported that he had taken native treatment with an osteopath where serial massages were done to relieve the pain, as there was no improvement in pain and shoulder mobility; he finally was referred to our hospital for a second opinion and further evaluation.

Treatment of developmental dislocation of hip

Avascular necrosis (AVN) of the femoral head is a serious complication in the management of developmental dislocation of the hip. Increasing the abduction angle increases its stability but compromises the vascularity of the femoral head. From our database of 240 children treated for developmental dislocation of hip by the two senior authors between 1998 and 2008, we defined two groups of children who underwent closed or medial open reduction of the hip after a failed Pavlik treatment or if patients presented late. In group 1, the reduced hip was immobilized in around 90° flexion, 60° abduction, and 0-10° internal rotation. In group 2 the hip was immobilized in around 45° of hip abduction with flexion and internal rotation as before. The first and second authors independently analysed these two groups blinded to the hip abduction angle. Our hypothesis was that a reduction in the hip abduction angle would reduce the incidence of AVN in the second group without compromising the stability. All eligible children were included, and there were 42 children in group 1 and 44 children in group 2. An almost equal number of children underwent closed and medial open reduction in both the groups. The age at reduction was a mode of 6 months (range 6-13 months) and 7 months (range 7-12 months), respectively. The abduction angle in the first group had a mode of 60° (range 52-70°) and the second group had a mode of 45° (range 38-50°). Radiographic evidence of AVN as described by Salter and colleagues was seen in eight children (19%) in the first group and seven children (16%) in the second group (P=0.78). Redislocation occurred in one child in the second group and none in the first group. In summary, the results show a nonsignificant reduction in the incidence of AVN when the hip abduction angle was reduced with no significant increased risk of redislocation.

Proximal humeral fractures: The role of calcium sulphate augmentation and extended deltoid splitting approach in internal fixation using locking plates

The aim of our study is to analyse the results of our surgical technique for the treatment of proximal humeral fractures and fracture dislocations using locking plates in conjunction with calcium sulphate bone-substitute augmentation and tuberosity repair using high-strength sutures. We used the extended deltoid-splitting approach for fracture patterns involving displacement of both lesser and greater tuberosities and for fracture-dislocations. Optimal surgical management of proximal humeral fractures remains controversial. Locking plates have become a popular method of fixation. However, failure of fixation may occur if they are used as the sole method of fixation in comminuted fractures, especially in osteopenic bone. MethodsWe retrospectively analysed 22 proximal humeral fractures in 21 patients; 10 were male and 11 female with an average age of 64.6 years (range 37–77). Average follow-up was 24 months. Eleven of these fractures were exposed by the extended deltoid-splitting approach. Fractures were classified according to Neer and Hertel systems. Preoperative radiographs and computed tomography (CT) scans in three- and four-part fractures were done to assess the displacement and medial calcar length for predicting the humeral head vascularity. According to the Neer classification, there were five two-part, six three-part, five four-part fractures and six fracture-dislocations (two anterior and four posterior). Results were assessed clinically with disabilities of the arm, shoulder and hand (DASH) scores, modified Constant and Murley scores and serial postoperative radiographs. ResultsThe mean DASH score was 16.18 and the modified Constant and Murley score was 64.04 at the last follow-up. Eighteen out of twenty-two cases achieved good clinical outcome. All the fractures united with no evidence of infection, failure of fixation, malunion, tuberosity failure, avascular necrosis or adverse reaction to calcium sulphate bone substitute. There was no evidence of axillary nerve injury. Four patients had a longer recovery period due to stiffness, associated wrist fracture and elbow dislocation. The CaSO4 bone substitute was replaced by normal appearing trabecular bone texture at an average of 6 months in all patients. ConclusionIn our experience, we have found the use of locking plates, calcium sulphate bone substitute and tuberosity repair with high-strength sutures to be a safe and reliable method of internal fixation for complex proximal humeral fractures and fracture-dislocations. Furthermore, we have also found the use of the extended deltoid-splitting approach to be safe and to provide excellent exposure facilitating accurate reduction for fixation of the fracture patterns involving displacement of both lesser and greater tuberosities and for fracture-dislocations.

Anatomic Variations in Femoral Head Circulation

The purpose of this cadaveric study was to clearly define the blood supply to the femoral head to help further reduce the incidence of iatrogenic avascular necrosis (AVN). Thirty-five hips of twenty-eight fresh cadavers were injected with colored silicone. Anterior and posterior dissection was performed to assess the vessels contributing to femoral head vascularity. The medial femoral circumflex artery (MFCA) was found to be the main blood supply to the hip in twenty-nine specimens; the inferior gluteal artery (IGA) was found to be the main blood supply in six. The MFCA consistently provided at least one smaller-calibre inferomedial retinacular artery. The foveal artery provided no significant vascular contribution in any specimen. The quantity and calibre of superior retinacular vessels demonstrated their dominance in head vascularity, although inferior retinacular arteries were consistently present. To reduce the risk of iatrogenic AVN, branches of both the IGA and MFCA traversing the interval between the quadratus femoris and piriformis muscles must be protected during surgery. Since all intracapsular vessels penetrated the capsule near its distal attachment, distal capsulotomy carries a significantly higher risk of AVN than proximal capsulotomy, particularly posterolaterally and inferomedially.

Authors’ reply

Authors’ reply

Intraoperative femoral head vascularity assessment: An innovative and simple technique (Letter 1)

Intraoperative femoral head vascularity assessment: An innovative and simple technique (Letter 1)

Comment on Sen et al.: Osteosynthesis of femoral-neck nonunion with angle blade plate and autogenous fibular graft

1. Femoral neck nonunion is associated, in the vast majority of cases, with varus malalignment; valgus intertrochanteric osteotomy is the recommended treatment of this problem in young patients. The osteotomy improves compression at the fracture site and improves the mechanical environment for healing. Only in those rare cases where femoral neck non-union is associated with no or minimal varus alignment, revision internal fixation with bone graft may be done [2]. 2. Intraoperative static compression of the fracture fragments and dynamic compression during the postoperative period are achieved with parallel screws; excellent compression can be produced atraumatically by the lag effect of the screws. Compression of the fragments cannot be achieved by a blade plate. 3. As emphasised by the authors in the manuscript, the femoral head in non-union of the femoral neck is compromised by osteoporosis, secondary to disuse, and bone deficiency in the femoral head due to previous hardware. In osteoporotic bone, medial anchoring of multiple pins is better than a single unit implant because of multiple site of purchase. A rigid single member such as a blade plate is in contact with one set of trabeculae. Once these trabeculae fail to hold the plate, motion occurs between the two fragments, which leads to failure of osteosynthesis. In a multiple pin assemblage, failure of one group of trabeculae with the pin or screw inside does not predispose to failure of another set of trabeculae with its pins. These trabeculae are widely separated and are resistant to motion [3]. 4. Fixed nails (blade plate) are notorious for penetrating into the hip joint or may cut out of the head and neck as opposed to cancellous cannulated screws (CCS), which do not penetrate into the hip joint or come out of the femoral head. 5. There is not enough space to apply blade plate due to the previous fixation tracts and the tract for the fibular graft. Moreover, inserting both blade plate and fibula in a limited space is technically demanding and cannot be done by an average orthopaedic surgeon. 6. Hammering the blade plate into femoral head causes distraction of the fracture fragments. Microfractures occur which may further damage the vascularity of head.

Anatomy of the medial femoral circumflex artery with respect to the vascularity of the femoral head

We performed a series of 16 anatomical dissections on Caucasian cadaver material to determine the surgical anatomy of the medial femoral circumflex artery (MFCA) and its anastomoses. These confirmed that the femoral head receives its blood supply primarily from the MFCA via a group of posterior superior nutrient arteries and the posterior inferior nutrient artery. In terms of anastomoses that may also contribute to the blood supply, the anastomosis with the inferior gluteal artery, via the piriformis branch, is the most important. These dissections provide a base of knowledge for further radiological studies on the vascularity of the normal femoral head and its vascularity after dislocation of the hip.

Intra-operative femoral head vascularity assessment: An innovative and simple technique

Background:Documentation of femoral head blood flow before, during and after head preserving surgery is important for safeguarding vascularity to the femoral head and for documentation in patients in whom the blood flow is compromised. Laser Doppler flowmetry and microsensor intracranial pressure (ICP) transducers have been used to satisfactorily depict such changes. However, these devices are expensive and not universally available in orthopedic operating rooms. We describe a new technique for the assessment of intra-operative blood flow to the femoral head. This is a technical description of a simple system utilized in eight patients to assess the femoral head vascularity using equipment available with the anesthetist.Materials and Methods:A standard epidural catheter attached to an arterial pressure transducer is introduced into the femoral head from the margin of the articular surface via a small hole drilled with a K wire. The pressure wave within the epiphysis is detected on the anesthesia monitor. Pressure within the femoral head is used as a surrogate for blood flow. The pressure and the wave form are correlated with the electrocardiogram (ECG) wave on the anesthetic machine. The technique was used in eight children with hip pathology requiring hip dislocation for documenting the hip vascularity status.Result:There was good correlation between the pressure wave and the ECG for a patient with presumed normal femoral head vascularity, whereas the pressure measurements were greatly reduced and the wave form was absent in a femoral head wih radiographic or bone scan evidence of avascular necrosis.Conclusion:This new technique is a cheap and readily accessible alternative to Laser Doppler flowmetery and ICPs monitoring probes for the assessment of blood flow to the femoral head.

Predictive factors for functional outcome and failure in angular stable osteosynthesis of the proximal humerus

Introduction Angular stable osteosynthesis has become the gold standard in the operative treatment of proximal humeral fractures. The aim of this article is to determine the indications for osteosynthesis versus primary arthroplasty based on clinical and radiological parameters. Methods A total of 368 surgically treated proximal humeral fractures were reviewed. Preoperative X-rays were used to evaluate the displacement and vascularity of the humeral head (according to the Hertel criteria) and the AO (Arbeitsgemeinschaft für Osteosynthesefragen) fracture type. Postoperative X-rays were analysed to assess the quality of the reduction, the reconstruction of the medial hinge and the displacement of the tuberosities. Follow-up X-rays were used to evaluate healing progress, the occurrence of avascular necrosis, loss of reduction and implant related failures. The American Shoulder and Elbow Surgeons score (ASES score) was used to evaluate the functional outcome. Correlations between a set of variables, type of treatment and eventual outcome were verified in both univariate and multivariate settings, with the significance rate set at p < 0.05. Results In total, 307 shoulders were evaluated. Mean follow-up was 4.3 years and showed a 15.3% failure rate, a 23.8% re-operation rate and a mean ASES score of 75.3. Better results were noted in patients who were younger at the time of surgery. More displaced fractures, AO type C fractures, varus fracture configuration and reduced head vascularity all led to a worse outcome. Anatomical reduction correlated with better results. Articular fractures had better results when treated with a plate. Conclusion Surgical treatment of proximal humeral fractures remains difficult, with a failure rate of 15.3% and a re-operation rate of 23.8% at 4.3 years. A significantly displaced varus articular fracture in the older patient results in the worst outcome.

Vascularization of the mandibular condylar head with respect to intracapsular fractures of mandible

Background Causes of mandibular condylar (condylar) head necrosis as a consequence of intracapsular mandibular fractures are still a subject of controversy. Objectives To investigate why in some cases of intracapsular fractures condylar head necrosis occurs. Material 58 human heads from the collection of Head and Neck Clinical Anatomy Laboratory, from the Institute of Physiology and Pathology of Hearing, Warsaw, Poland, constituted the material. Study Head arterial tree injections, anatomical preparation with the use of standard set of microsurgical equipment and an operating microscope. Results The main source of condylar head vascularization is the inferior alveolar artery, supplying bone marrow of the whole mandible as well as its cortical layer. Additional arterial blood supplying comes from a various number (2–7) of branches supplying the temporomandibular joint capsule. They originate directly from the maxillary artery or from its primary branches: masseteric artery, external pterygoid artery or superficial temporal artery. Two rare variants of accessory mandibular head vascularization were encountered. The first (2 cases) was an arterial branch from the maxillary artery and the second (1 case) was a branch from the external pterygoid artery. In these cases the arterial supply of lateral part of temporomandibular joint capsule from other sources was reduced. Conclusion Fractures resulting in the lateral part of the condylar head in isolation could be potentially threatened by necrosis because of poor vascularization.

Can injection CT scan assess the residual femoral head vascularity after acute neck fracture?

Femoral neck fracture jeopardizes the vital prognosis of the elderly subject and the functional prognosis of the young subject. The vascular consequence is important, with the risk of osteonecrosis of the femoral head. In young patients, predicting the risk of necrosis at the acute stage seems warranted so as to optimize the choice of therapy. CT with injection could be useful to study the residual bone vascularity after an acute fracture of the femoral neck. The CT scan with injection can diagnose ischemia of the femoral head after neck fracture by demonstrating hypoperfusion and thus estimating the risk for osteonecrosis. A CT scan with injection was performed prospectively in 20 adult patients who had given informed consent after verification of the inclusion and exclusion criteria. Ten presented femoral neck fracture and 10 a pertrochanteric fracture, the latter making up the control group. The second control group was the healthy side of patients presenting a femoral neck fracture. The images were analyzed after delineating a region of interest as a volume at the center of the femoral head. The results were analyzed after modeling based on the physical principle of diffusion. No differences were found between the "healthy hip," "fractured hip," "femoral neck fracture," and "trochanteric region fracture" groups. The only statistically significant correlation was found between the "fractured hip" and "healthy hip" of the same patient independently of the type of fracture. The results do not confirm the working hypothesis. This study was mainly limited by the small number of patients included, but this did not substantially effect the study's conclusions. According to the results, it seems that this study provided a CT evaluation of bone mineral density. At the end of the study, it seems that CT with injection is not well adapted in assessing residual femoral head vascularity or estimating the risk of progression towards avascular necrosis. According to the literature, only dynamic MRI with injection seems to be effective in this assessment and estimation. Level III prospective comparative diagnostic.

Percutaneous Pinning of Proximal Humerus Fractures: A Technique

Proximal humerus fractures are commonly seen, yet the treatment of many displaced fractures presents significant challenges. Complications related to humeral head vascularity have caused a recent interest in minimally invasive techniques for fracture fixation. The technique of closed reduction and percutaneous fixation of proximal humerus fractures is difficult and demanding, and careful attention must be paid to appropriate indications and technical considerations. This article discusses the indications and techniques for percutaneous fixation of proximal humerus fractures.

Magnetic Resonance Imaging in Traumatic Posterior Hip Dislocation

The objective was to report the ability of a magnetic resonance image to document the integrity of the obturator externus tendon after posterior hip dislocation as a potential predictor for preserved femoral head vascularity. Retrospective radiographic and clinical pilot study. Level I trauma center. Nineteen consecutive patients with traumatic posterior hip dislocation. OUTCOME EVALUATION: Intraoperative correlation of soft tissue damage and radiographic assessment of avascular necrosis of the femoral head 3 years postinjury. Magnetic resonance imaging performed in the acute phase of posterior hip dislocation. Correlation with intraoperative findings during surgical hip dislocation and with avascular necrosis 3 years postinjury. The obturator externus tendon was intact in all cases with preserved femoral head vascularity. After a 3-year follow up, there were no cases of avascular necrosis. In this small series of patients, posterior hip dislocation did not imply a tear of the obturator externus muscle. An intact obturator externus tendon suggests preservation of the deep branch of the medial femoral circumflex artery to the femoral head.

The influence of the size of the component on the outcome of resurfacing arthroplasty of the hip

The survivorship of contemporary resurfacing arthroplasty of the hip using metal-on-metal bearings is better than that of first generation designs, but short-term failures still occur. The most common reasons for failure are fracture of the femoral neck, loosening of the component, osteonecrosis of the femoral head, reaction to metal debris and malpositioning of the component. In 2008 the Australian National Joint Registry reported an inverse relationship between the size of the head component and the risk of revision in resurfacing hip arthroplasty. Hips with a femoral component size of </= 44 mm have a fivefold increased risk of revision than those with femoral components of >/= 55 mm irrespective of gender. We have reviewed the literature to explore this observation and to identify possible reasons including the design of the implant, loading of the femoral neck, the orientation of the component, the production of wear debris and the effects of metal ions, penetration of cement and vascularity of the femoral head. Our conclusion is that although multifactorial, the most important contributors to failure in resurfacing arthroplasty of the hip are likely to be the design and geometry of the component and the orientation of the acetabular component.

Femoral Head Vascularity. Impact and Implications for Hip Resurfacing Arthroplasty

Summary:The blood supply to the resurfaced femoral head has been implicated in the early failure of implants. The extraosseous supply to the femoral head is threatened both during the approach and the preparation of the femoral head to receive an implant. The presence or degree of intraosseous suppl

Locking plate fixation of three- and four-part proximal humeral fractures

We evaluated the functional results of open reduction and internal fixation with a locking plate in patients with three- or four-part fractures of the proximal humerus. We reviewed 32 consecutive patients (22 women, 10 men; mean age 63 years; range 29 to 82 years) who were treated with open reduction and internal fixation using the PHILOS locking plate for comminuted proximal humeral fractures. According to the Neer classification, 12 patients (mean age 56 years) had three-part fractures, 19 patients (mean age 67 years) had four-part fractures, and one patient had a four-part fracture dislocation. Ten patients were in the age group of <60 years, 22 patients were in the age group of 60=or>years. All the patients were evaluated with plain radiographs preoperatively; in addition, computed tomography was used in 14 patients in whom articular surface and tuberculum displacement could not be assessed adequately. The operation was performed through a standard deltopectoral approach, and minimal soft tissue dissection was used aiming not to impair vascularization of the fracture fragments. A cerclage wire was used to help reduction in 12 patients. An oblique screw was inserted to stabilize the medial colon in cases in which medial cortical contact was insufficient. Bone grafting was not used in any of the patients. Active-assisted and passive exercises of the shoulder were initiated on the second postoperative day. Active abduction to 90 degrees was allowed two weeks after surgery. During follow-up, implant failure, loss of reduction, malunion, and bone healing were assessed on plain radiographs. Bone scintigraphy was performed after 12 postoperative months for the detection of avascular necrosis. The results were assessed using the Constant shoulder score. The mean follow-up period was 25 months (range 18 to 36 months). An anatomic or near-anatomic reduction was obtained in 29 patients (90.6%). In two patients, the fractures were fixed in a varus position, and in one patient, the greater tubercle was displaced proximally. All fractures united in a mean of three months (range 2 to 5 months). The mean Constant score of the patients was 79.5 (range 50 to 100). The results were excellent in 13 patients (40.6%), good in nine patients (28.1%), fair in eight patients (25%), and poor in two patients (6.3%). The mean Constant scores were 88.3 (range 69 to 100) and 74.2 (range 50 to 100) in three-part and four-part fractures, and 88.3 (range 71 to 100) and 75.5 (range 50 to 100) in the age groups of <60 years and =or>60 years, respectively. Constant scores showed significant differences with respect to the number of comminution and age groups (p=0.03). Avascular necrosis was observed in two patients. None of the patients had reduction loss, implant failure, deep infection, or neurovascular injury, and none required implant removal. Preservation of humeral head vascularity through minimal soft tissue dissection, fixation with a locking plate, and early postoperative motion were effective in decreasing potential complications following surgical treatment of three- and four-part proximal humeral fractures. The degree of fracture comminution and age of the patients affect functional results significantly.