Determination of a Safe Zone for Ischial Screw Placement in Total Hip Arthroplasty.

BACKGROUND: Implantation of acetabular components with supplemental screw fixation is commonly performed to improve osteointegration and long-term stability in total hip arthroplasty (THA). Placement of ischial screws improves stability in biomechanical studies, but can be technically challenging. The study aimed to provide a safe zone for ischial screw placement with reference to easily identifiable intra-operative landmarks. METHODS: A retrospective review of patients was performed and 27 preoperative pelvis computed tomography scans were collected. After converting these images to 3-dimensional reconstructions of the pelvis, a safe zone for ischial screw placement was established with reference to the anterior superior iliac spine (ASIS) and the acetabular center and rim. RESULTS: The safe zone of an ischial screw in the en face sagittal plane was a median of 17 degrees (interquartile range [IQR]: 11,23) anterior to 13 degrees (IQR: 10,18) posterior to the reference line from the ASIS through the center of the acetabulum. The safe zone in the coronal plane was 34 degrees (IQR: 18,68) medial to 13 degrees (IQR: 8,19) lateral from a start point 1 centimeter medial to the inferior acetabular rim with a screw length of 25 millimeters. An ischial screw optimized for length directed down the center of the ischium was qualitatively demonstrated to have a start point unobtainable intraoperatively, originating within the cotyloid fossa. CONCLUSION: The ASIS, center of the acetabulum, and acetabular rim provide identifiable intraoperative landmarks for guiding ischial screw placement in hip arthroplasty.

Making the cut: a technical note and literature review of Bernese periacetabular osteotomy techniques with special attention to ischial osteotomy initiation and completion with an inside to anterior curved osteotomy.

Periacetabular osteotomy includes a fluoroscopy-guided ischial cut without direct visualization. Previously described techniques include a mediolateral ischial cortex cut, which is associated with the risk of injuring nearby nerves. Another drawback of that technique is the difficulty connecting an ischial cortex cut with a retroacetabular cut due to orthogonal nature of the osteotomy. In general, an additional cut from medial to lateral is required. The present study aimed to describe a technique that eliminates those problems due to use of only a central cut of the ischium and the curved nature of the osteotomy.

Endoscopic Ischial Tuberosity Osteophyte Resection for Treatment of Ischiofemoral Impingement: A Case Report.

ABSTRACT: Ischiofemoral impingement is a distinct pathologic finding with abnormal osseous contact between the ischium and the lesser trochanter of the femur. Lesser trochanter excision has been recommended for recalcitrant ischiofemoral impingement through an open or endoscopic approach; however, no study has included ischial tuberosity osteophyte resection and refixation of the hamstring tendon. We report an endoscopic procedure involving ischial tuberosity osteophyte resection with refixation of the partially detached hamstring insertion through a posterior approach in the prone position. Using this technique, it is easier to reach the lesion and less likely to injure the sciatic nerve. The postoperative pain score (visual analogy score) was significantly decreased, the modified Harris hip score increased from 39 preoperatively to 86 postoperatively, and there was no adverse effect on the hamstring tendon.

Defining the canal for ischial and pubic screws in cup revision surgery.

PURPOSE: When revising acetabular cups, it is often necessary to provide additional stabilisation with screws. In extensive defect situations, the placement of screws caudally in the ischium and/or pubis is biomechanically advantageous. Especially after multiple revision operations, the surgeon is confronted with a reduced bone stock and unclear or altered anatomy. In addition, screw placement caudally is associated with greater risk. Therefore, the present study aims to identify and define safe zones for the placement of caudal acetabular screws. METHODS: Forty-three complete CT datasets were used for the evaluation. Sixty-three distinctive 3D points representing bone landmark of interests were defined. The coordinates of these points were then used to calculate all the parameters. For simplified visualisation and intra-operative reproducibility, an analogue clock was used, with 12 o'clock indicating cranial and 6 o'clock caudal. RESULTS: A consistent accumulation was found at around 4.5 ± 0.3 hours for the ischium and 7.9 ± 0.3 hours for the pubic bone. CONCLUSIONS: The anatomy of the ischium and pubis is sufficiently constant to allow the positioning of screws in a standardised way. The interindividual variation is low - regardless of gender - so that the values determined can be used to position screws safely in the ischium and pubis. The values determined can provide the surgeon with additional orientation intra-operatively when placing caudal acetabular screws.

Delayed proximal hamstring tendon repair after ischial tuberosity apophyseal fracture in a professional volleyball athlete: a case report.

BACKGROUND: Ischial tuberosity apophyseal fractures are avulsion fractures of the anatomic footprint of the proximal hamstring tendons. Generally, these injuries are rare and frequently occur in skeletally immature, active patients due to incomplete ossification. Depending on the fragment displacement, non-operative or operative treatment approaches are used. CASE PRESENTATION: We report a case of a 29-year-old professional volleyball athlete who has suffered from a nonunion avulsion fracture for 14 years. Isolated suture anchor fixation was performed after open excision of a large bony fragment followed by excellent clinical and functional outcome at 1 year postoperatively. CONCLUSION: In conclusion, avulsion fractures of the ischial tuberosity with large fragments and restrictions to activities of daily living due to pain can, in individualized cases, be treated with an open excision of the fragment followed by repair of the proximal hamstring tendons using suture anchors.

The ischiofemoral space of the hip is influenced by the frontal knee alignment.

PURPOSE: The ischiofemoral distance (IFD), defined as the distance between the ischial tuberosity and the lesser trochanter of the femur, is gaining recognition as an extra-articular cause of hip pain. It is unknown whether the IFD is influenced by the frontal knee alignment. The aim of this study was to determine the influence of realignment surgery around the knee on the IFD. It was hypothesized that valgisation osteotomy around the knee is associated with reduction of the IFD. METHODS: A consecutive series of 154 patients undergoing frontal realignment procedures around the knee in 2017 were included in this study. Long-leg standing radiographs were obtained before surgery and postoperatively. The IFD was measured between the ischium and the lesser trochanter at three different levels (proximal, middle and distal margins of the lesser trochanter parallel to the horizontal orientation of the pelvis) on standardized long-leg radiographs with the patient in upright standing position. The knee alignment was determined by measuring the hip knee ankle angle, mechanical lateral distal femur angle and the medial mechanical proximal tibia angle. Linear regression was performed to determine the influence of the change of frontal knee alignment on the IFD. RESULTS: Linear regression showed a direct influence of the overall change in frontal knee alignment on the IFD of the hip, regardless of the site of the osteotomy (ß-0.4, confidence-interval - 0.5 to - 0.3, p < 0.001). Valgisation osteotomy around the knee induced a significant reduction of the ipsilateral IFD (p < 0.001), while varisation osteotomy induced a significant increase (p < 0.001). The amount of ISD change was 0.4 mm per corresponding degree of change in frontal knee alignment. CONCLUSION: These findings are relevant to both the hip and knee surgeons when planning an osteotomy or arthroplasty procedure. Correction of a malalignment of the knee may resolve an ischiofemoral conflict in the hip. The concept deserves inclusion in the diagnostic workup of both the hip and knee joints. LEVEL OF EVIDENCE: IV.

Surgical repair techniques, functional outcome, and return to sports after apophyseal avulsion fractures of the ischial tuberosity in adolescents.

PURPOSE: Among juvenile apophyseal avulsion injuries of the pelvis in adolescents, fractures of the ischial tuberosity are rare but sustainably debilitating. Also because informations on surgical repair options are very sparse and so far limited to general reviews, reports of individual cases or heterogeous small case series, practitioners, patients and their parental environment still feel a comprehensible hesitation regarding operative treatment. Therefore we intended to investigate patient related outcome measurements and return to sports rates after different types of surgical intervention in an own case series, so far unprecendented in its size. METHODS: Patient data of adolescents that underwent surgical intervention for a displaced apophyseal avulsion fracture of the ischial tuberosity between 01/2015 and 12/2019 in our institution were gathered. Patients were then evaluated using the hamstring injury specific Perth Hamstring Assessment Tool (PHAT). Furthermore the return to sports level in comparison to the particular pre-injury level was rated. RESULTS: Eleven adolescents with an acute or chronic mean fragment dislocation of 3.3 cm (SD ± 1.7) underwent surgical intervention in the assigned period. The mean post-operative PHAT score was 86.9 (0-100, SD ± 11.9) and thus good to excellent. The majority of adolescents (10/11) was able to return to their pre-injury sports, whereas 63.6% achieved full or nearly full level. CONCLUSIONS: Surgical refixation or restoration of aphoyseal avulsion fractures of the ischial tuberosity result in good to excellent outcomes and return to sport rates, irrespective of the type of intervention. Here prompt diagnosis with a timely intervention seems more promising than delayed interventions in chronic cases. Beyond 1.5 cm of fragment displacement affected patients should be counselled for surgical intervention.

Infra-acetabular screw exited between ischial tuberosity and ischial spine is more suitable for Asian population: a 3D morphometric study.

BACKGROUND: Recently, the infra-acetabular screw has been proposed for use in treatment of acetabular fractures as a part of a periacetabular fixation frame. Biomechanical studies have shown that an additional infra-acetabular screw placement can enhance the fixation strength of acetabular fracture internal fixation. Currently, the reported exit point of the infra-acetabular screw has been located at the ischial tuberosity (Screw I). However, our significant experience in placement of the infra-acetabular screw has suggested that when the exit point is located between the ischial tuberosity and the ischial spine (Screw II), the placement of a 3.5 mm infra-acetabular screw may be easier for some patients. We conducted this study in order to determine the anatomical differences between the two different IACs. METHODS: The raw datasets were reconstructed into 3D models using the software MIMICS. Then, the models, in the STL format model, were imported into the software Geomagic Studio to delete the inner triangular patches. Additionally, the STL format image processed by Geomagic Studio was imported again into MIMICS. Finally, we used an axial perspective based on 3D models in order to study the anatomical parameters of the two infra-acetabular screw corridors with different exit points. Hence, we placed the largest diameter virtual screw in the two different screw corridors. The data obtained from this study presents the maximum diameter, length, direction, and distances between the entry point and center of IPE. RESULTS: In 65.31% males and 40.54% females, we found a screw I corridor with a diameter of at least 5 mm, while a screw II corridor was present in 77.55% in males and 62.16% in females. Compared to screw I, the length of screw II is reduced, the angle with the coronal plane is significantly reduced, and the angle with the transverse plane is significantly increased. CONCLUSIONS: For East Asians, changing the exit point of the infra-acetabular screw can increase the scope of infra-acetabular screw use, especially for females.

Repair of Sacral and Ischial Region Defects With Lateral Sacral Artery Perforator Flaps.

BACKGROUND: Reconstructive choices for the defects of the sacral and ischial regions include various steps of the reconstructive ladder from primary closure to free flaps. This study aimed to present repair of sacral and ischial region defects with lateral sacral artery perforator (LSAP) flaps. METHODS: We enrolled a total of 18 patients with sacral and ischial region defects reconstructed with LSAP flaps in the study between September 2014 and October 2015. The patients were evaluated in terms of age, sex, neurological situation, etiology, defect size, defect region, flap size, perforator number, and postoperative complications. RESULTS: No patient had hematoma, seroma, and complications of the donor area. In the postoperative period, 2 patients were observed to have short-term complications (11.1%) including a partial flap loss (5.5%) due to distal venous failure (flap survival rate, 95%) and a wound site infection (5.5%). Duration of follow-up of the patients ranged between 26 and 38 months. Recurrence was observed from long-term complications of 4 patients' pressure sores (22%). CONCLUSIONS: The LSAP flap has not been frequently described in the literature. We believe that LSAP flap is a flap of choice that should be considered preferably for sacral and ischial defects, which can be reliably elevated over pedicles and has short surgery duration and low surgical morbidity.

Avulsion Fractures of the Ischial Tuberosity: Progress of Injury, Mechanism, Clinical Manifestations, Imaging Examination, Diagnosis and Differential Diagnosis and Treatment.

Avulsion fracture of the ischial tuberosity (AFIT) is a rare adolescent sports injury. At present, there is no consensus on its therapeutic paradigm, but conservative treatment appears to be the predominate choice. Furthermore, the degree of fracture displacement (DFD) remains as an important factor in determining whether AFIT needs internal fixation. The aim of the present study was to review and update the injury mechanism, clinical manifestations, imaging examination, diagnosis and differential diagnosis, and treatment of AFIT. A literature search was performed on a variety of databases using text words, and the results were limited to the English language. This review provides an important reference for the diagnosis and treatment of AFIT. AFIT can be easily misdiagnosed. Therefore, a detailed medical history and imaging examination are crucial for a correct diagnosis and differential diagnosis. For the choice of treatment of AFIT, it is necessary to consider not only the size of the fracture and DFD, but also the long-term functional needs of the patient.

A New Option for the Reconstruction of Primary or Recurrent Ischial Pressure Sores: Hamstring-Adductor Magnus Muscle Advancement Flap and Direct Closure.

BACKGROUND: Owing to the high recurrence rates of ischial pressure sores, surgeons should consider the possibility of future secondary flap surgery during flap selection. The purpose of this article is to present a new surgical option for the reconstruction of primary or recurrent ischial pressure sores using a simple hamstring-adductor magnus advancement flap and direct closure. METHODS: After horizontal fusiform skin excision, complete bursa excision and ischiectomy were performed. The tenomuscular origin of the adductor magnus and the conjoined tenomuscular origin of the biceps femoris long head and semitendinosus were isolated and completely detached from the inferior border of the ischial tuberosity. They were then advanced in a cephalad direction without detachment of the distal tendon or muscle and securely affixed to the sacrotuberous ligament. The wound was directly closed without further incision or dissection. RESULTS: Twelve ischial pressure sores (6 primary and 6 recurrent; 12 patients) were surgically corrected. The follow-up period was 12 to 65 months. All patients healed successfully without early postoperative complications, such as hematoma, seroma, infection, wound dehiscence, or partial necrosis. Late complications included wound disruption 5 weeks after surgery that spontaneously healed in 1 case and recurrence 3 years later in another case. CONCLUSIONS: The new surgical option presented herein, which involves hamstring-adductor magnus advancement flap and direct closure, is a simple and reliable method for providing sufficient muscle bulk to fill the dead space and proper padding to the bone stump while preserving the main vascular perforators and pedicles as well as future surgical options.

Operative treatment of pelvic apophyseal avulsions in adolescent and young adult athletes: a follow-up study.

INTRODUCTION: Pelvic apophyseal avulsion can limit young athletes' performance for months and may result in permanent disability. Nonoperative treatment is most commonly preferred, while surgical management with reduction and fixation is reserved for selected cases. Our aim was to evaluate outcomes of operative management of pelvic apophyseal avulsions in a series of adolescents and young adult athletes. MATERIALS AND METHODS: Operative room registries and medical records were reviewed to identify patients who received surgical treatment for pelvic apophyseal avulsions who were younger than 24 years and with a minimum of 12 month follow-up. RESULTS: Thirty-two patients (16.8 years ± 2.6) were identified. The most common avulsion sites were anterior inferior iliac spine (34.4%, N = 11) and ischial tuberosity (34.4%, N = 11). Other avulsions were five cases (15.6%) of the pubic apophysis, four cases (12.5%) of the anterior superior iliac spine apophysis and one case of the iliac crest apophysis. Seventeen cases (53.1%) underwent surgery early, i.e., during the first 3 months after the acute injury. Twenty-two cases (68.8%) involved reduction with internal fixation, and six cases (18.8%) involved resection of the fragment. Twenty-six athletes (81.3%, N = 26) reported good outcomes and were able to return to preinjury sports level. Six patients (18.8%) had moderate outcome and reported activity limitations during high-level sports. Large displacement (> 20 mm) or delayed (> 3 months) surgery was not associated with inferior outcomes (P = 0.690 and P = 0.392, respectively). Injury side (P = 0.61) or gender (P = 0.345) did not affect outcomes. CONCLUSIONS: Operative management of pelvic apophyseal avulsion results in return to the preinjury sports level in more than 80% of the cases. However, while both acute surgery for large displacement and delayed intervention for failed nonoperative treatment are generally successful in improving sports function in these cases, comparative studies are required to refine criteria for surgery. LEVEL OF EVIDENCE: Case series, IV.

The Assessment of Limb Length Discrepancy Before Total Hip Arthroplasty.

INTRODUCTION: The clinical relevance of limb length discrepancy (LLD) after total hip arthroplasty gains attention as the number of total hip arthroplasties increases. Although several techniques are commonly used to assess LLD using a pelvic radiograph, their accuracy is not well established. This study measures LLD using different techniques viewing the pelvis and compares the measurements with the true LLD. METHOD: Pelvic landmarks used included the femoral head, lesser trochanter, acetabular teardrop, ischial tuberosity, and tibial plafond. The true LLD was determined by finding the difference in distance between the lowest point of the ischial tuberosity and the tibial plafond as well as the top of the femoral head to the center of the tibial plafond for each lower limb. RESULTS: Using pelvic landmarks to assess LLD is significantly different (P < .001) from the true LLD. The difference in distance from the center of the tibial plafond to the ischial tuberosity was not significantly different from the measurement from the top of the femoral head to the center of the tibial plafond (P = .08). Also, using the acetabular teardrop as a landmark has less reliability when compared to the ischial tuberosity. DISCUSSION: Owing to the extensive variety of pathologies that are associated with LLD, preoperative planning should include an assessment of any preexisting LLD. Although it may be reasonable to compare pelvic measurements preoperatively and postoperatively to assess for changes, the data from this study do not support the estimation of the true LLD using a pelvic radiograph.

Triple pelvic osteotomy for the treatment of symptomatic acetabular dysplasia in adolescents and adults : A review of 42 hips.

We treated 42 hips with symptomatic acetabular dysplasia using triple pelvic osteotomy. The mean age of the patients was 20.7 years (12-47). The median follow-up was 50.3 months. The average Harris hip score improved from 74 to 92 points. Significant improvement from the preoperative to the latest follow-up evaluation was seen radiologically with reference to the center-edge angle, the anterior center-edge angle, the acetabular index and the femoral head extrusion index. Shenton's line was intact in 9 hips before the operation and it was intact in 40 hips at the latest follow-up. The cross-over sign was present in 15 hips before the operation and it was present in one hip after the operation. The results of this study demonstrated that triple pelvic osteotomy provides improved radiographic results and good symptomatic relief in acetabular dysplasia.

In utero and postnatal imaging findings of parasitic conjoined twins (ischiopagus parasiticus tetrapus).

Conjoined twins are a rare developmental anomaly with a reported prevalence of 1.47 per 100,000 births. We present an uncommon case of a parasitic ischiopagus tetrapus with a parasitic ischiopagus partial twin joined to the complete fetus at the level of the ischium diagnosed in utero by fetal MRI. The correct prenatal diagnosis led to birth by caesarean section. Prenatal MRI findings are presented and corroborated by postnatal imaging delineating the full extent and associated anomalies of this rare malformation. Differential diagnosis of duplicated lower extremities is discussed.

Surgical management of traumatic avulsion of the ischial tuberosity in young athletes.

OBJECTIVE: Complete traumatic avulsion of the ischial tuberosity in young athletes is rare, and the optimal treatment is unclear. The purpose of this article is to present our experience and the efficacy of surgical repair of avulsions of the ischial tuberosity with bony dislocation of more than 2 cm and to discuss the complex postoperative rehabilitation. METHODS: Three young athletes sustained complete avulsion of the ischial tuberosity with bony dislocation during different sport activities (long jump, soccer, sprinting). The age at the time of injury ranged from 13.8 to 15 years. All underwent surgical repair with reattachment of the hamstring muscle complex to the origin on the ischium. The time from injury to repair varied from 2 to 22 weeks. All patients underwent a specific postoperative rehabilitation program. Follow-up ranged from 12 to 24 months. RESULTS: All athletes had improved with surgery and had good subjective and objective functional results. One patient needed operative revision 1 day after primary repair because of suture loosening because of excessive muscle contractions during wake up after general anesthesia. Finally, all returned to their preinjury sport at the same level. CONCLUSIONS: Young athletes with traumatic avulsion of the ischial tuberosity and dislocation of more than 2 cm benefit from operative repair. Good results were achieved in all cases on the basis of functional recovery and patient satisfaction. Chronic complaints could be avoided, and also return to sport was possible. Surgery under spinal anesthesia is recommended.

Ischiectomy With Limb Preservation for a Dog With Ischial Chondrosarcoma: Case Report and Surgical Technique.

OBJECTIVE: To describe the surgical technique for ischiectomy in the dog and to report the procedure in a case. STUDY DESIGN: Case report. ANIMAL: An 11-year-old spayed female mixed breed dog with chondrosarcoma of the ischium. METHODS: The dog presented for hindlimb lameness and evaluation after a radiographic finding of a lytic lesion confined to the left ischium. Following staging and confirmation of stage 1 disease, an ischiectomy with preservation of the hindlimb was performed. RESULTS: The dog recovered from surgery and was initially moderately lame on the hindlimb. Over time, the dog regained satisfactory hindlimb use and was alive >500 days postoperative with no evidence of local recurrence or metastatic disease. CONCLUSIONS: Ischiectomy with hindlimb preservation is a technically straight-forward procedure and in this case, resulted in good hindlimb function postoperatively. The procedure should be considered for the treatment of dogs with bone tumors confined to the ischium.

Treatment for ischial tuberosity avulsion fractures in adolescent athletes.

PURPOSE: Avulsion fractures of the ischial tuberosity are rare sports injuries typically occurring in young athletes. Their misdiagnosis may lead to chronic pain or disability. The aim of this study is to report a retrospective series of patients sustaining a fracture of the ischial tuberosity and to propose decision guidelines. METHODS: The mechanism of accident, the diagnostic management, the mode of treatment and outcome after avulsion fractures of the ischial tuberosity in adolescents were analysed. RESULTS: Thirteen patients (1 female and 12 males) with a median age of 15 years (range 13-16 years) with an avulsion fracture of the ischial tuberosity were included. Twelve of these patients suffered from sports injuries leading to the avulsion fracture. Five of our patients with a displacement of >15 mm were treated operatively. The outcome was excellent in cases of acute presentation and osteosynthesis. Eight patients were treated conservatively: four of them showed a displacement of <15 mm and had an excellent outcome; and the other four patients had a displacement of >15 mm. Two of those patients had excellent outcome with regular bone healing, the remaining two patients developed pseudarthrosis associated with a good outcome. CONCLUSION: The present paper shows that in patients with displacement of <15 mm, conservative treatment yields excellent results and early operative intervention should be considered in physically active patients with displacement of >15 mm.

Ischio-pubic stress fracture after peri-acetabular osteotomy in patients with hip dysplasia.

PURPOSE: Ischio-pubic stress fracture is one of the potential complications after peri-acetabular osteotomy (PAO) in patients with hip dysplasia. The purpose of this study was to examine the prevalence of and risk factors for ischio-pubic fractures following PAO. METHODS: A total of 296 hips in 275 patients who underwent transposition osteotomy of the acetabulum between 2001 and 2012 were retrospectively reviewed. Patient characteristics and radiographic parameters were compared between patients with and without fracture. RESULTS: Fourteen ipsilateral hips (4.7%) in 14 female patients had fracture of the inferior pubic ramus (11 hips) or the ischial ramus (three hips) on the same side as the surgery at an average of 4.6 weeks after PAO. Multivariate analysis indicated that younger age at operation (odds ratio of 1.43 per five years, p = 0.0169) and greater degree of correction (odds ratio of 1.98 per five degrees, p = 0.0005) were significantly associated with ischio-pubic fracture as independent risk factors. All fractures healed conservatively with partial weight-bearing. CONCLUSIONS: Younger female patients and greater deformity corrections increased the risk of ischio-pubic stress fracture after PAO.

[Surgical treatment of ischial apophysis avulsion. Case report]. / Operacní lécba avulze apofýzy sedacího hrbolu - kazuistika.

The optimal management of ischial apophysis avulsion, especially indications for surgery, is not well defined. The authors present the case of a 16-year-old man who sustained an avulsion fracture of the ischial apophysis during his athlete training programme. The avulsion was diagnosed by X-ray. Because of displacement, surgery was indicated and open reduction with osteosynthesis was performed using a subgluteal approach on the eighth day after injury. Full weight bearing was allowed at nine weeks after injury, after the post-operative rehabilitation programme had been completed. Return to his sports activity was allowed at four months after injury. At one post-operative year the patient was free of any symptoms. The proper surgical treatment of a displaced ischial apophysis avulsion and subsequent rehabilitation allow for early full weight bearing, including sports activities. The subgluteal approach provides good access to the ischial tuberosity with a minimal risk of complications and a good cosmetic outcome. Key words:apophysis, ischial tuberosity, avulsion.