Symptomatic hypertrophic pubic ramus nonunion treated with a retrograde medullary screw

A screw view model of navigation guided minimal invasive percutaneous pelvic screws insertion for lateral compression pelvic ring injuries: A case report

RATIONALE

The objective of the present study was to evaluate the accuracy, effectiveness, and safety of screw view model of navigation (SVMN) guided minimal invasive percutaneous pelvic screws (PPSs) insertion for lateral compression pelvic ring injuries (PRI).

PATIENT CONCERNS

A female patient experienced a high falling injury, and presented with pain, swelling, deformity, and movement limitation of the left hip for 3 hours.

DIAGNOSES

She was diagnosed with pelvic fractures, left iliac fracture, left pubic branch fracture, left ischial branch fracture, and lumbar transverse process fracture.

INTERVENTIONS

We used a SVMN technique to guide PPSs insertion, including a percutaneous anterior inferior iliac spine screw, a percutaneous iliac screw (PIS), and a percutaneous sacroiliac screw (PSIS).

OUTCOMES

In total, 3 PPSs were inserted and all were presented with excellent position postoperatively. The designing time of all screws was 11.7 minutes, the time of all guide needles insertion was 18.1 minutes, the time of all screws insertion was 32.8 minutes, blood loss was 21 mL, and the time of radiation exposure lasted 7.2 minutes. Moreover, surgical complications, including neurovascular compromise, wound infection, fracture nonunion, and screw loosening, were not observed during the 12 months follow up visit.

LESSONS

SVMN technique guided PPSs insertion is an effective and safety approach for the treatment of PRI in selected patients. Besides, it is necessary for surgeons to master the rationale of computer navigation, to familiar with the anatomy of pelvis and to select suitable patients.

A screw-view model of navigation aid retrograde transpubic screw fixation for anterior pelvic ring fracture: A case report with 28 months follow-up and technical note

RATIONALE

The purpose of this study was to evaluate the accuracy of a retrograde transpubic screw fixation assisted by a screw-view model of navigation in treating a pelvic fracture.

PATIENT CONCERNS

A 30-year-old female patient injured in a motor vehicle accident, displayed symptoms characterized by swelling and pain of the pudendum.

DIAGNOSES

The patient was diagnosed with a fracture of the pubic ramus.

INTERVENTIONS

We used a screw-view model of navigation to assist our retrograde transpubic screw fixation in this patient.

OUTCOMES

In total, 2 screws were inserted into the bilateral pubic ramus and both were excellently positioned. It took 7.4 minutes to design the screws, 8.1 minutes to implant the guidewire, and 39.3 minutes to place the screws. Intraoperative blood loss amounted to 21 mL and the total fluoroscopic time was 3.8 minutes. No clinical complications, such as neurologic, vascular, or urologic injury, infection, screw loosening, or loss of reduction, were found after the operation. Follow-up lasted 28 months.

LESSONS

The outcome of our study suggests that the screw-view model of navigation maximizes the retrograde transpubic screw insertion accuracy in the treatment of a pubic ramus fracture, which is made efficient by pain relief and early out-of-bed mobilization. Our suggestion is, therefore, that the relative position between the pubic ramus and the patient tracker must be static to ensure the accuracy of the entire system throughout the operation.

Minimally Invasive Screw Fixation of Inferior Pubic Ramus Stress Fracture Nonunion in a Runner: A Case Report

CASE

A fifty-one-year-old female runner developed a stress fracture of the inferior pubic ramus. Nonoperative treatment was initiated, but the symptoms persisted and she was diagnosed with a nonunion. After eleven months of symptoms and ten months of nonoperative treatment, including four months of complete avoidance of running, percutaneous screw fixation was performed, with radiographic and clinical healing of the fracture.

CONCLUSION

While inferior pubic ramus stress fractures are usually successfully treated nonoperatively, instances of nonunion and delayed union have been described. In the present report, we describe the case of a patient in whom an inferior pubic ramus stress fracture nonunion was successfully treated with minimally invasive screw fixation.

Posttraumatic Perineal Pubic Rami Protrusion: A Simple Surgical Management

Although pubic ramus fractures are common, they usually heal without surgical intervention and result in little long-term disability. We herein present two cases of symptomatic malunion of pubic rami fracture, which was successfully treated with a simple and safe surgical technique. The patients' local symptoms resolved afterwards.

Preliminary results of cannulated screw fixation for isolated pubic ramus fractures

Isolated pubic ramus fractures are common fractures in the elderly, and treatment is typically non-operative. Up to 35 % of patients have a prolonged hospital stay due to pain. A small number of these patients do not respond to standard (non-operative) treatment. We retrospectively reviewed six patients with isolated pubic ramus fractures and persistent pain who were treated with percutaneous retrograde pubic ramus screw fixation. The study group consisted of six women with an average age of 81 years (72–86 years). Patients with symptomatic posterior pelvic ring injuries were excluded. All patients showed improvement after surgery, with three patients pain free and three patients with reduced pain. The mean time spent in the hospital was 9 days (range 3–18 days). There were complications post-operatively: two patients had pneumonia, two with confusional states, and one patient had a urinary tract infection. Despite these events, which are associated with surgery in patients with comorbidites from advanced age, retrograde pubic ramus screw fixation is an effective treatment option for patients with persistent pain from isolated pubic fractures.

Volumetric analysis of corticocancellous bones using CT data

OBJECTIVE

To present a method for an automated volumetric analysis of corticocancellous bones such as the superior pubic ramus using CT data and to assess the reliability of this method.

MATERIALS AND METHODS

Computed tomography scans of a consecutive series of 250 patients were analyzed. A Hounsfield unit (HU) thresholding-based reconstruction technique ("Vessel Tracking," GE Healthcare) was used. A contiguous space of cancellous bone with similar HU values between the starting and end points was automatically identified as the region of interest. The identification was based upon the density gradient to the adjacent cortical bone. The starting point was defined as the middle of the parasymphyseal corticocancellous transition zone on the axial slice showing the parasymphyseal superior pubic ramus in its maximum anteroposterior width. The end point was defined as the middle of the periarticular corticocancellous transition zone on the axial slice showing the quadrilateral plate as a thin cortical plate. The following parameters were automatically obtained on both sides: length of the center line, volume of the superior pubic ramus between the starting point and end point, minimum, maximum and mean diameter perpendicular to the center line, and mean cross-sectional area perpendicular to the center line.

RESULTS

An automated analysis without manual adjustments was successful in 207 patients (82.8%). The center line showed a significantly greater length in female patients (67.6 mm vs 65.0 mm). The volume was greater in male patients (21.8 cm(3) vs 19.4 cm(3)). The intersite reliability was high with a mean difference between the left and right sides of between 0.1% (cross-sectional area) and 2.3% (volume).

CONCLUSIONS

The method presented allows for an automated volumetric analysis of a corticocancellous bone using CT data. The method is intended to provide preoperative information for the use of intramedullary devices in fracture fixation and percutaneous cement augmentation techniques.

Treatment and outcomes of pelvic malunions and nonunions: a systematic review

Although acute management of pelvic fractures and their long-term functional outcome have been widely documented, important information regarding malunion and nonunion of these fractures is sparse. Despite their relative rarity, malunions and nonunions cause disabling symptoms and have major socioeconomic implications. We analyzed the factors predisposing a pelvic injury to develop malunion/nonunion, the clinical presentation of these complications, and the efficacy of the reported operative protocols in 437 malunions/nonunions of 25 clinical studies. Treatment of these demanding complications appeared effective in the majority of the cases: overall union rates averaged 86.1%, pain relief as much as 93%, patient satisfaction 79%, and return to a preinjury level of activities 50%. Nevertheless, the patient should be informed about the incidence of perioperative complications, including neurologic injury (5.3%), symptomatic vein thrombosis (5.0%), pulmonary embolism (1.9%), and deep wound infection (1.6%). For a successful outcome, a thorough preoperative plan and methodical operative intervention are essential. In establishing effective evidence-based future clinical practice, the introduction of multicenter networks of pelvic trauma management appears a necessity.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Anatomic study for pubic medullary screw insertion

PURPOSE

To study the anatomy of the pubic ramus and adjacent structures in 160 Japanese to establish a safer pubic screw fixation technique.

METHODS

80 male and 80 female Japanese aged 16 to 89 (mean, 50) years (10 persons in each decade of age) underwent 3-dimensional computed tomographic scanning of their pelvises. The angle at which the screw should be targeted, the appropriate length of the screw, the size of the canal for screw insertion, and the proximity to the bladder, iliac artery, and iliac vein were determined. Correlations between the canal diameters (of the acetabular, base, and parasymphyseal areas) and body features (age, height, and weight) were analysed.

RESULTS

In men and women respectively, the appropriate mean screw length was 124.6 and 123.8 mm; the guide wire should be targeted at a mean of 66 degrees and 67 degrees cephalad and 54.1 degrees and 55.9 degrees laterally for insertion of a retrograde pubic screw; the minimum distances from the pubis to the bladder/iliac artery/ iliac vein were 0 and 0 mm/4.9 and 4.6 mm/0.8 and 0.2 mm. In both men and women, the canal diameters at the base were positively correlated to weight. In women, the canal diameters at the parasymphyseal area were correlated to height and weight. Canal diameters at the acetabulum were not correlated to height and weight.

CONCLUSION

Pubic screw fixation may be potentially disastrous (owing to joint penetration and iliac vein injury) and should be performed with caution. When the canal diameter at the acetabulum is extremely narrow, plate fixation, computer-assisted surgery, or changing to a smaller-diameter screw is recommended.

[Pseudoarthrosis of anterior pelvic ring fracture]

It is rare for there to be healing problems after anterior pelvic fractures. An internet search produced only a small number of hits. This paper recounts the course in two patients who experienced symptomatic nonunion of anterior pelvic fractures after stable osteosynthesis with locking plates. Stable internal fixation with locking plates eventually led to successful healing after both nonunion of the ischial ramus and nonunion of the transitional zone between the inferior pubic ramus and the ischial ramus, and also of nonunion of the superior pubic ramus, in both patients. The study demonstrates that it is possible to stabilise nonunion of the superior pubic ramus by internal fixation of the ischial ramus and of the transitional zone between the inferior pubic ramus and the ischial ramus with locking plates.

Superior pubic ramus fractures fixed with percutaneous screws: what predicts fixation failure?

OBJECTIVE

The purpose of this study is to present the early complications of percutaneous screw fixation of superior pubic ramus fractures and to present a new classification scheme for superior pubic ramus fractures.

DESIGN

Retrospective.

SETTING

Level 1 trauma center.

PATIENTS

One hundred and twelve patients with pelvic fracture between the ages of 14 to 89 years underwent percutaneous screw fixation of 145 pubic ramus fractures. Eighty-one patients with 107 surgically repaired fractures were followed to fracture union. Follow-up averaged 9 months (range 2-52 months). One additional patient who sustained fixation failure 4 days after surgery was included to yield a study group of 82 patients with 108 surgically repaired ramus fractures.

INTERVENTION

Patients underwent percutaneous screw fixation of a superior pubic ramus fracture.

MAIN OUTCOME MEASUREMENTS

Superior pubic ramus fractures were classified according to a new scheme, the Nakatani system, which categorizes superior ramus fractures according to location with respect to the obturator foramen. Patient radiographs were examined for evidence of loss of reduction, defined as any motion at the ramus fracture site or hardware motion, after fracture surgery.

RESULTS

Of the 82 patients followed to union or fixation failure, 12 (15%) had loss of reduction on follow-up radiographs. The average age of patients who lost reduction was 55 years. The most common mechanism of reduction loss was a collapse of the pubic ramus over the screw, with recurrence of an internal rotation deformity of the injured hemipelvis. Ten patients who lost reduction were women, and 11 had undergone ramus screw placement in retrograde fashion. No loss of reduction was seen in Zone III ramus fractures (those that involve the bone lateral to the obturator foramen). No patient sustained recognized neurologic, vascular, or urologic injury as a result of percutaneous screw fixation of a superior pubic ramus fracture.

CONCLUSIONS

The prevalence of loss of reduction after percutaneous screw fixation of pubic ramus fractures is 15%. Loss of reduction is more common in elderly and female patients and in patients whose ramus screws are placed in a retrograde fashion. Also, loss of reduction appears to be more common in fractures medial to the lateral border of the obturator foramen.

Percutaneous augmentation of the superior pubic ramus with polymethyl methacrylate: treatment of acute traumatic and chronic insufficiency fractures

The injection of polymethylmethacrylate (PMMA) is a minimally invasive image-guided procedure that is typically used to treat vertebral body fractures due to osteoporosis or neoplastic involvement. The injection of PMMA into various other locations including the sacrum, acetabulum, pedicles, femur and tibia has been reported previously, and these procedures have, overall, been highly effective at alleviating pain and discomfort. Although the injection of PMMA into the vertebral body is a very common procedure that has been performed for over 2 decades for the percutaneous treatment of vertebral body fractures, the percutaneous injection of PMMA has not been reported in the English literature as treatment for superior pubic ramus fractures. We report the percutaneous treatment of an acute superior pubic ramus fracture and of a chronic insufficiency fracture of the superior pubic ramus using a parasymphyseal approach to access the region of injury.

Percutaneous retrograde screwing for stabilisation of acetabular fractures

OBJECTIVES

To evaluate the results of retrograde percutaneous screw fixation (PSF) in minimally or undisplaced acetabular fractures in a geriatric population.

PATIENTS AND METHODS

Between July 1998 and July 2001, 21 consecutive patients with an acetabular fracture underwent fluoroscopic guided percutaneous fixation. The mean age was 81 years (range 67--90 years). In all cases, the fracture was minimally or undisplaced (<2mm). Two cannulated cancellous 7.3mm screws were inserted in a retrograde fashion to stabilise the posterior and the anterior column. Bed to chair transfer began after 24h. Weight bearing as tolerated was allowed at 4 weeks.

RESULTS

Eighteen patients were reviewed at a mean of 3.5 years (range 2--5 years). Soft tissue dissection was minimal. There were no intraoperative or postoperative complications. At the latest follow-up there was no radiographical evidence of secondary displacement of fragments, degenerative changes, or screw failure. Fractures healed at a mean time of 12 weeks (range 8--15 weeks). Clinical results were satisfactory in 17 patients.

CONCLUSION

Our results show that percutaneous screw fixation under fluoroscopic control is a safe technique to treat some pattern of acetabular fracture.

A modification of the retrograde medullary screw for the treatment of bilateral pubic ramus nonunions: a case report

We describe a patient with bilateral pubic ramus nonunions who was treated successfully with a modification of the retrograde medullary screw technique, in which the screw orientation was altered so that it engaged the cancellous bone in the inferior part of the anterior column and the anterior-inferior cortex of the fossa acetabuli. The modification should be one option when the original technique is judged to be difficult to perform.