Reduction Of Head Research Articles

Uniform infection screening allowed safe head and neck surgery during the coronavirus disease 2019 pandemic in Japan.

BackgroundThe purpose of this study was to determine whether a uniform infection screening protocol could be used to safely perform head and neck cancer surgery during the coronavirus disease 2019 pandemic and clarify how surgical treatment changed compared with the pre-pandemic period.Materials and methodsDuring the unprecedented coronavirus disease 2019 pandemic in Tokyo, we continued providing head and neck cancer care, guided by our own uniform screening protocol. In this study, medical records of 208 patients with head and neck malignancy, who underwent surgical treatment at our hospital during the first and second wave of pandemic for each 2-month period (first wave: 30 March 2020–30 May 2020, second wave: 14 July 2020–14 September 2020) and the 2-month pre-pandemic period (30 October 2019–30 December 2020), were analysed.ResultsA total of 133 patients were admitted for surgical treatment and all, except six patients with emergency tracheostomy, were screened according to the protocol. As a result, all 127 patients received surgical treatment as planned, and all 1247 medical staff members involved in the surgeries were uninfected by severe acute respiratory syndrome coronavirus 2. During the first wave of pandemic, 20% reduction of head and neck surgery was requited; however, restrictions of surgery were not necessary during the second wave. Surgical procedure, length of hospitalization, postoperative complications and number of medical staff were unchanged compared with pre-pandemic period.ConclusionOur data indicate that continuation of head and neck anticancer surgical treatment in an epidemic area during the coronavirus disease 2019 pandemic were safe and feasible, if adequate and strict preventive measures are vigorously and successfully carried out.

Dimeglio's derotation of calcaneo pedal block and Pirani's talar head reduction: a quantitative matching.

We aimed to determine the quantitative value of derotation of calcaneo pedal block (DCPB) of Dimeglio system equivalent to talar head reduction of Pirani system. We also compared the ankle dorsiflexion obtained post tenotomy for different measures of DCPB. The study involved 53 idiopathic clubfoot children (86 feet) treated with Ponseti technique. Percutaneous Achilles tenotomy to correct ankle equinus was performed when forefoot adduction, heel varus were corrected and ankle dorsiflexion was <10°. Pirani's coverage of lateral head of talus was taken as a determinant of adequate DCPB and to perform tenotomy. Mean patient age at enrollment was 60.9 ± 71.1 days. The median pre and posttreatment Dimeglio scores were 13 (range 4-20) and 0 (range 0-3), respectively. DCPB at the time of talar head reduction was 53.8 ± 9.8°. In 85% feet, talar head reduction was obtained by DCPB 60° and all were reduced by 70°. The average ankle dorsiflexion improved significantly with DCPB ≥ 50°. The measure at which DCPB matched with talar head reduction of Pirani system was variable (40-70°). In all feet, talar head was reduced by 70° DCPB. Post tenotomy, ankle dorsiflexion was better with DCPB ≥ 50°.

Bilateral Monteggia Fracture: A Rare Case Presentation.

Introduction:Giovanni Monteggia was the first to describe two cases of fractures of the proximal third of ulna with dislocation of the radial head. Monteggia fractures much more commonly are seen in children than in adults, but the bilateral entity is rare in both age groups. The following case is about the course of treatment for bilateral Monteggia fractures in a young male.Case Report:A 35-year-old male came to the emergency with alleged history of roadside accident. Radiography showed bilateral Monteggia fracture type III (by the Bados classification). Surgical intervention was required with locking compression plates put on the both sides. Closed reduction of the radial head was done on both sides. The patient was given pop slabs for bilateral forearms for 21 days. After removing the splints, the function of the elbow was determined by the Broberg Morrey score which was on the right side 45 and on the left side 47 and 100 on both sides after 5 months of follow-up.Conclusion:Surgical intervention and early rehabilitation are the most important and ideal line of treatment for the return of the good function of both elbows. Diagnosis, surgical technique, rehabilitation program, and clinical results are reported. The bilateral nature of the presentation does not affect the outcome of the fractures.

Evaluation of the association between olecranon fracture and radial head subluxation or annular ligament displacement in children.

Olecranon fractures are seen substantially more often in children than in adult and are potentially occult in nature. We noticed this fracture pattern in two cases of delayed Monteggia fracture. Our study purpose was to confirm whether olecranon fracture is associated with radial head subluxation or annular ligamentous displacement in children. In addition, we have developed an effective and simple approach to avoid serious treatment-related complications as much as possible. Forty-eight pediatric patients with olecranon fracture and normal radiocapitellar alignment on radiography were enrolled. All patients' fingers, forearms and elbows were examined carefully, and treated with a modified radial head reduction approach and then cast immobilization. MRI of the affected elbow was performed in 16 symptomatic patients. Overall, 70.83% of patients had a positive clinical finding of radial head subluxation. These symptomatic patients presented with similar clinical findings that typically included painful finger movement actively or passively and movement limitation of forearm and elbow. MRI showed that annular ligaments were interposed and trapped in the radiohumeral joint. In 34 symptomatic patients, 91.18% of them achieved fair radial head reduction during the first reduction attempt. Herein, 95.85 and 100% of patients reported excellent and satisfactory outcomes, respectively. Radial head subluxation occurred in most children with an olecranon fracture. We highly suggest performing a careful physical examination to identify this fracture pattern. Early reduction of the radial head with the modified approach may be a simple and primary option for emergency room doctors.

Association of radial head dislocation with fracture and acute plastic deformation of the ulna: unreported subtype of Monteggia fracture-dislocation in children.

Treatment of a Monteggia fracture-dislocation primarily includes anatomical reduction and fixation of the ulna. However, in rare cases, reduction of the radial head remains impossible even after performing this standard procedure. We have encountered patients with Monteggia fracture-dislocation whose radial head could be reduced by 'overcorrecting' the ulna. In this retrospective study, we aimed to propose an unreported subtype of Monteggia fracture-dislocation. Data of three patients (age 6, 14, and 16 years) with Monteggia fracture-dislocations whose radial head could not be reduced by anatomical fixation of the ulna were retrospectively reviewed. In all three patients, the radial head could not be reduced by anatomical reduction and internal fixation of the ulna even after confirmation of the absence of interposed tissue such as annular ligament in the radiocapitellar joint. However, the radial head could be reduced by fixation of the ulna in a posterior convex shape at the fracture site. At the final follow-up, stable reduction of the radial head was maintained in all patients. We hypothesized that these patients had simultaneous existence of a fracture and acute plastic deformity of the ulna. To the best of our knowledge, this pathological state has not been reported previously but it may not be extremely rare and may only be unrecognized. We believe that a new subtype, that is, type A + C, should be established based on Letts' classification.

Complex Monteggia Fractures in the Adult Cohort: Injury and Management.

Monteggia fractures involve proximal ulna fracture associated with a radiocapitellar joint dislocation. The Bado classification is primarily based on the direction of the radial head dislocation. The Jupiter subtype classification of Bado II fractures further characterizes the severity of proximal ulna comminution and the involvement of the coronoid fragment. This latter classification can better prognosticate the challenges of surgical reconstruction and clinical outcomes. Surgery for all adult Monteggia fractures is required to restore the anatomic alignment of the ulna, which indirectly reduces the radiocapitellar joint. The complexity of the injury is considerably increased by comminution of the proximal ulna, the degree of radial head fragmentation, the reduction of the radial head, and ulnohumeral instability. Anatomic reduction is considered critical to achieving a favorable outcome.

Study on the effects of runner geometries on the performance of inline cross-flow turbine used in water pipelines

To supply continuous and reliable power to the water monitoring systems and motorized control valves in urban water supply networks, the inline cross-flow turbine has been developed. This study aims to investigate the effects of different runner geometries on the performance of inline cross-flow turbines and to determine the optimal runner geometrical parameters. In this paper, a theoretical analysis of the working mechanism of a cross-flow runner is first performed to study the impacts of the runner geometry on turbine performance. Thereafter, several turbine models with different runner geometries are built and simulated to analyse the output power, water head reduction and torque generation at each runner stage. The results indicate that a good match between the flow inlet angle and blade outer angle notably enhances the turbine performance. Based on the results, the recommended optimal blade outer angle in this research is 30°. In addition, the results also show that the runner diameter ratio has a major impact on torque generation at the runner first stage. A lower runner diameter ratio leads to a higher output power, but the water head reduction is also higher. Based on the results, the suggested runner diameter ratio is 0.68. A numerical study on the number of blades indicates that when the number of blades increases from 20 to 24, the turbine output power considerably rises, and the maximum output power reaches 2285 W. However, if the blade number is further increased, the variation in output power is very slight. Thus, the proposed optimal blade number is 24. Based on the research results, the maximum turbine efficiency can reach 50.9% after runner optimization.

An atypical type of monteggia equivalent: A case report

Monteggia fracture dislocations comprise about 5-10 % of all forearm fractures in adults and was first described in 1814. Since then there has been many descriptions of Monteggia equivalents. We present a case of 33 year old female with fracture of diaphysis of ulna with fracture shaft of radius proximal 1/3rd with posterior radial head dislocation managed by open reduction and internal fixation of both radius and ulna by LCDCP and screws with reduction of radial head and its functional outcome.

Efeitos do exercício físico na alteração postural e funcionalidade de idosos: cuidados ao longeviver saudável

Estudo de abordagem intervencionista, objetivou avaliar os efeitos do exercício físico na alteração postural e condição funcional de seis idosas participantes de um núcleo interdisciplinar de pesquisa e extensão, incluídas por apresentar alterações posturais, problemas reumatológicos, Hipertensão Arterial Sistêmica (HAS) e/ou Diabetes Mellitus tipo 2 (DM2). Adotou-se o Instrumento de avaliação Postural (IAP); Simetográfo; Escala de Avaliação Analógica (EVA), entrevista semiestruturada e um protocolo cinesioterapêutico, adaptado à investigação, implementado em três sessões semanais, de sessenta minutos cada em dias alternados, em um total de 25 sessões. Dos resultados: IAP à vista anterior, houve redução de 66% para 33% na rotação de cabeça a E; melhora em alinhamento das cristas ilíacas de 50% para 66%; redução de rotação externa de quadril de 84% para 66%; melhora em geno valgo de joelhos de 33% para 16%. À vista lateral: redução da projeção da cabeça para frente de 66% para 33%; redução de ombros protusos de 66% para 33%. A redução da dor à EVA foi significativa para cinco das seis participantes e, HAS e DM2 com redução expressiva em 100%. Conclui-se que a abordagem cuidativa proximal contribuiu à melhoria da saúde das participantes, potencializou a adesão às atividades físicas regulares no núcleo e se reverteu em mais aquisição de benefícios ao processo de viver humano saudável ao longeviver.

Regulation of epithelial integrity and organ growth by Tctp and Coracle in Drosophila.

Regulation of cell junctions is crucial for the integrity of epithelial tissues and organs. Cell junctions also play roles in controlling cell proliferation for organ growth. Translationally controlled tumor protein (TCTP) is a conserved protein involved in growth control, but its role in cell junctions is unknown. Here we show that Drosophila Tctp directly interacts with the septate junction protein Coracle (Cora) to regulate epithelial integrity and organ growth. Tctp localizes together with Cora in the epidermis of the embryo. Loss of Cora reduces the level of Tctp in the epidermis but not vice versa. cora/+ or Tctp/+ single heterozygotes develop normally to adulthood. However, double heterozygotes for cora and Tctp mutations show severe disruption of epithelia causing synthetic lethality in the embryo. Double knockdown of Cora and Tctp in eye imaginal disc synergistically leads to disruption of the eye disc, resulting in a severe reduction or loss of eye and head. Conversely, double knockdown of Cora and Tctp in wing disc causes overgrowth as well as cell death. Inhibition of cell death under this condition causes hyperplastic growth of the wing disc. Tctp also shows direct and functional interaction with Cora-associated factors like Yurt and Na+/K+-ATPase. This study suggests that proper levels of Tctp and Cora are essential for the maintenance of the Cora complex and the integrity of epithelia. Our data also provide evidence that both Cora and Tctp are required to suppress overgrowth in developing wing.

Effects of COVID-19 Pandemic on Otolaryngology Surgery in Italy: The Experience of Our University Hospital.

Otolaryngology and head and neck surgery underwent drastic changes during the COVID-19 pandemic. Since March 10, the first day of the lockdown in Italy, diagnostic and therapeutic procedures were limited to emergency and oncology cases, while outpatient procedures and clinical examinations were temporarily suspended to limit virus diffusion and to reallocate personnel into wards dedicated to COVID-19. In our otolaryngology unit, between March 10 and April 28, 2020, we performed 96 surgical procedures; they mainly consisted in diagnosis and treatment of malignant tumors of the head and neck (77%), management of acute upper airway obstruction in adults and children (14.7%), drainage of abscesses of the head and neck (6.2%), and treatment of nasal bone fractures (2.1%). When comparing these data with those of the same period in 2019 for emergency and oncology procedures, we noticed a drastic reduction of head and neck abscesses and nasal bone fractures, while oncology surgery remained stable.

Are full-face helmets the most effective in preventing head and neck injury in motorcycle accidents? A meta-analysis.

Motorcycles are the most common type of vehicle involved in traffic deaths in developing countries. Although helmets can provide protection against injury, there is limited evidence available regarding which type of helmet best protects against head and neck injuries in this setting. This review was conducted based on articles in the PubMed, Scopus, and Web of Science databases. We compared full-face helmets with other types of helmet with regard to head and neck injury prevention in road accidents involving motorcyclists. Of 702 studies, six were eligible with a total of 6,529 participants. When compared with partial and open helmets, the odds ratio of full-face helmets was 0.356 (95% CI of 0.280, 0.453) and 0.636 (95% CI of 0.453, 0.894), respectively, for reduction of head and neck injuries. In conclusion, full-face helmets reduced head and neck injuries in motorcycle accidents to a greater extent than other types of helmet. Policy makers should recommend that motorcyclists use full-face helmets.

Step-cut osteotomy in neglected Monteggia fracture dislocation in pediatric and adolescent patients: A retrospective study.

Neglected Monteggia fracture dislocation in children leads to significant restriction of daily activities by causing decreased range of motion at elbow, stiffness, deformity, and neurological compromise. Various treatment strategies have been described in the literature and one of them is ulnar osteotomy combined with reduction of radial head and annular ligament reconstruction. The aim of this study was to evaluate the results of step-cut osteotomy without the use of bone grafting with reconstruction of annular ligament in the management of neglected Monteggia fracture dislocation in children. A retrospective study was conducted in six patients with neglected Monteggia fracture dislocation with a mean age of 8.83 years. The median interval between the original injury and the corrective surgery for 6 patients was 4.4 months (range 1-12 months). All children underwent step-cut osteotomy of ulna, open reduction of radial head, and annular ligament reconstruction. Mayo Elbow Performance Index (MEPI) score was used for evaluation. The ulnar osteotomies healed uneventfully without the need for a bone graft. Elbow range of motion improved post-op along with improved elbow functioning as indicated by raised MEPI score. The MEPI score was excellent in 5 cases and fair in 1 case. Step-cut osteotomy alone without the use of bone grafting and reinforcement with annular ligament repair is a simple yet effective technique for treating neglected Monteggia fracture dislocation.

Four different management strategies in missed Monteggia lesions in children

ObjectivesManagement of missed Monteggia lesions presents a challenging clinical scenario for pediatric orthopaedic surgeons as the patient may be exposed to possible morbidities and increased complications. There are several evidenced surgical strategies described. We aimed to present 18 patients diagnosed within 4 months of injury who were treated using 4 of the identified many surgical strategies. MethodsEighteen consecutive cases of missed Monteggia lesions were treated in our institution between 2011 and 2014. The mean delay from injury to surgery was 8.3 weeks (range 4–16). Bilateral preoperative and postoperative radiographs, Oxford Elbow Score, the direction of radial head dislocation, Bado classification, ulnar pathology (plastic deformation or fracture), carrying angle, head–neck ratio, any abnormal bony architecture, and any related condition. ResultsThere were no major complications to surgery. All patients had regained painless range of motion of the forearm and elbow, and reduced radiocapitellar joint. Ligament reconstruction or transcapitellar k-wire fixation did not influence the radiographic or clinical outcome. ConclusionsBecause conservative treatment of this injury may cause high morbidity, surgical management should be preferred in the foreground. The ulnar deformity is a key point in the reduction of the radiocapitellar joint. The preferred treatment strategy has no significant effect on the results as long as it provides radial head reduction.

Derotational Subtrochanteric Osteotomy and External Fixation for the Treatment of Neurogenic Hip Dislocation in Children with Cerebral Palsy: Could This Be a Viable Method of Treatment?

PurposeThe treatment of painful and chronic dislocated hip in children with severe cerebral palsy (CP) is particularly demanding and controversial. Numerous surgical techniques have been described, and their outcomes vary a lot. The purpose of the present study is to evaluate a new method, which combines varus derotational subtrochanteric osteotomy (VDSO) and external osteosynthesis: (VDSOEO).MethodsSix non-ambulatory children with spastic quadriplegia and chronic dislocated painful hips were treated. The technique involved a small incision on the subtrochanteric site of the osteotomy, followed by retention with a single-sided external osteosynthesis with rotational correction capability [swiveling clamp (SC)] for the reduction of the femur head in the acetabulum, and finally by the osteotomy. Hardware was removed without a second intervention four-six months postoperatively and after the osteotomy was healed. Evaluation of the method was based on clinical, functional, and radiological criteria.Results Four patients achieved improved radiological scores. Two patients demonstrated resubluxation during the period of the osteotomy's healing process. However, no patients experienced pain, and all were able to sit post-surgery, while caregivers reported improved capacity for nursing care.ConclusionsIt is our strong belief that this approach can improve the quality of life in children with severe CP and painful and chronic dislocated hips. It is a viable and definitely less invasive procedure than classic pelvic or femur osteotomies.

Femoral Head Fracture without Dislocation of Hip in a Young Adult: A Case Report.

Introduction:Femoral head fractures are a rare pathology most often arising with high-energy traumas and associated with hip dislocations, which gravely compromise the ultimate functional outcome of the hip. Femoral head fractures without dislocation or subluxation are extremely rare injuries.Case Report:A 23-year-old male who sustained a high-energy trauma due to road traffic accident. He presented to ER with fracture of shaft femur, multi-ligament injury at the ipsilateral knee, fracture lower pole patella, ipsilateral fracture talus, and calcaneus along with comminuted fracture femoral head. He was managed by open reduction and internal fixation of the femoral head by safe surgical dislocation of the hip joint. Such injuries have been described rarely in the literature until now. The purpose of this report is to highlight the extreme rarity, possible mechanism involved, surgical management, and functional outcomes of such injuries.Conclusion:Femoral head fracture without dislocation is a very rare entity, early diagnosis, especially in high-energy trauma scenarios to prevent the neglect and delay in the treatment which is the paramount importance of an excellent result in young patients.

Radial head anterior dislocation and ulna bowing in a children

A 11 year old boy is examined three days after going to the emergency room, in consultation with orthopaedic surgery for right elbow pain after a fall on the hand. The clinical examination revealed oedema of the external part of the elbow with a deficit in flexion and supination. X-rays revealed anterior dislocation of the head radial associated with plastic deformation of the ulna (A). It´s about an equivalent type 1 Monteggia lesion according to the Bado classification. The line of Mubarak highlights the deformation plastic of the ulna on x-rays of profile. The treatment consisted of a closed orthopaedic reduction under sedation by external maneuvers directed in the opposite direction of the plastic deformation of the ulna and dislocation of the radial head under scopic control which was satisfactory. Patient was immobilized in a long arm cast in 90 degrees of flexion and supination and followed closely radiographically for 2 weeks to ensure maintenance of radial head reduction (B). After four weeks the patient begins functional rehabilitation. The two-month check showed a painless stable elbow with symmetrical supination and flexion. Evolution is pejorative in the absence of a early reduction. A Radial neuropathy can also occur in the longer term by compression, hence the importance of early diagnosis.

Functional Outcome of Bell Tawse Procedure for the Management of Chronic Unreduced Monteggia Fracture-Dislocation in Children

Aim of Study:Unreduced or missed Monteggia fracture-dislocation after 4 weeks is a common presentation in a tertiary care center. The aim of this study is to study the functional outcome of Bell Tawse procedure for the management of chronic unreduced Monteggia fracture-dislocation in children.Materials and Methods:In this retrospective study with prospective data collection, 17 children were treated with open reduction of the radial head and annular ligament reconstruction (Bell Tawse) combined with ulnar osteotomy. The cases were classified based on Bado's classification. The minimum period of followup was 14 months and maximum followup was 18 months with the mean period of followup of 16.2 months. Preoperative and postoperative Mayo Elbow Performance Index (MEPI) scores were calculated. We also compared the preoperative and postoperative Kim's elbow functional scores.Results:At the final followup, the radial head was maintained in a completely reduced position in 16 children. Mean preoperative MEPI score was 76.76 and mean postoperative score was 91.11, which was statistically significant (P < 0.001). Mean preoperative Kim's score was 76.94 and mean postoperative score was 91.35, which was also statistically significant (P < 0.001). One girl had a mild subluxation of the radial head at 1-year followup. The ulnar osteotomy was united in all 17 children, and none of them required secondary procedures. We have not identified any complications such as compartment syndrome, infection, posterior interosseous nerve palsy, avascular necrosis of the radial head, or loss of range of motion.Conclusion:We recommend ulnar osteotomy, open reduction of the radial head, and annular ligament reconstruction in children with unreduced Monteggia fracture-dislocation before long term complications sets in.

Efficacy of open reduction and locking plate fixation via subacromial anterolateral approach for proximal humerus fracture

Objective To investigate the clinical efficacy of subacromial anterolateral small incision approach with open reduction and internal fixation with proximal humeral locking system (PHILOS) for proximal humeral fractures. Methods A retrospective case-control study was conducted to analyze the complete medical records of 76 patients with proximal humeral fractures admitted to the Department of Traumatic Surgery, Fujian Provincial Hospital from April, 2013 to December, 2017. There were 22 males and 54 females, aged from 25 to 89 years [(60.4±16.4)years]. All patients had closed fractures. According to Neer classification, there were 12 patients of type II, 46 patients of type Ⅲ, and 18 patients of type IV. The duration from injury to operation ranged from 1 to 10 days [(4.4±1.9)days]. All patients received treatment of open reduction fixation with PHILOS. Forty patients received subacromial anterolateral small incision approach with percutaneous interactive reduction and internal fixation of humerus head and humerus shaft, including four patients of Neer type II, 26 patients of type III, and 10 patients of type IV (minimally invasive group). Thirty-six patients received the deltopectoral approach with reduction and internal fixation, including eight patients of type II, 20 patients of type III, and 8 patients of type IV (conventional group). The total length of incision, the operation time, intraoperative blood loss, hospitalization time, review of the neck angle with X-ray 1 week after surgery, and the fracture healing after 6 months, the ipsilateral Neer shoulder joint function score at 6 months after surgery and complications were compared. Results All patients were followed up for 3-12 months [(9.2±1.7)months], and there were six patients lost to the follow-up including four of the minimally invasive group and two of the conventional group. In the minimally invasive group and the conventional group, the total length of incision was 6.0(6.0, 6.8)cm and 11.5(10.0, 15.0)cm ( P 0.05), the intraoperative blood loss was 100(80, 150)ml and 175(100, 200)ml (P 0.05), the neck-shaft angle was (134.7±2.5)° and (134.6±2.6)°(P>0.05). A total of 70 patients obtained good bone healing. At 6 months after operation, the Neer shoulder function score of the affected side in the minimally invasive group was excellent in 30 patients, good in four patients, and fair in two patients, with the excellent and good rate of 96%, and for conventional group the score was excellent in 20 patients, good in eight patients, and fair in six patients, with the excellent and good rate of 84%(P<0.05). There was no complication in the minimally invasive group, but axillary nerve injury was found in one patient in the conventional group. Conclusion For the proximal humerus fracture, compared with the traditional deltopectoral approach, the subacromial anterior lateral small incision approach with percutaneous humeral head and humeral shaft reduction and interal fixation has the advantages of smaller incision, less bleeding and better functional recovery, which is a minimally invasive and effective treatment. Key words: Humeral fractures; Acromion; locking plate

Modification of Classical Horseshoe Spillways: Experimental Study and Design Optimization

Investigation of the hydraulic aspects of spillways is one of the important issues regarding hydraulic structures. This study presents a modified horseshoe spillway (MHS) constructed by adding a flow passage and an internal weir in the bed of a classical horseshoe spillway (CHS). This modification increased the discharge efficiency and eliminated the rooster-tail hydraulic jump in CHSs. Eighteen laboratory-scale MHSs in various geometric sizes, six various CHSs, and a rectangular weir of the same width were constructed and tested under the same flow conditions. Results showed that in terms of discharge efficiency and water head reduction, CHSs and MHSs were superior to the rectangular weir. Compared to CHSs, the increased discharge flowrate in MHSs due to the internal weirs could further reduce the water head and thus increased their overall efficiencies. Design parameters effecting spillways’ discharge efficiencies were investigated based on dimensional analysis. The internal to external weir length ratio in MHSs was found to be a key design factor. To determine the optimal geometric design of CHS and MHS models, cubic polynomial models considering dimensionless parameters and their interactions were fitted to the experimental results. The cubic models revealed that higher discharge efficiencies in MHSs tended to occur at relatively low water heads and high internal to external weir lengths ratios.