Extensive Soft Tissue Dissection Research Articles

Nasofrontal Heterotopic Ossification Following Lymphangioma Resection

Heterotopic ossification (HO) is the formation of mature lamellar bone in soft tissues. Heterotopic ossification can occur locally following surgical trauma, most commonly after total hip arthroplasty. Periosteal stripping, organizing hematoma, and extensive soft tissue dissection have been associated with subsequent HO. Craniomaxillofacial HO is rare and almost always associated with injury to the muscles of mastication. We present a report of biopsy-established HO of the cranium. An 18-month-old boy presented with a soft, compressible mass in the forehead midline, which did not extend intracranially on computed tomography scan. Surgical exploration revealed a poorly marginated lymphangioma infiltrating the periosteum of the nasofrontal region. This was debulked to restore nasofrontal contour. Two months postoperatively, after minor accidental trauma, the patient developed a subperiosteal hematoma that was evacuated in the clinic. Eight months postoperatively, the patient returned with a visible nasofrontal prominence overlying a firm immobile mass. Computed tomography scan revealed a 3-cm horn-like osseous structure extending inferiorly from the frontal bone across the nasofrontal junction. The bony mass was resected via a coronal approach and confirmed as HO with hematopoietically active marrow.

Compartment Syndrome Following Lower Limb Arthroplasty: A Review

Compartment syndrome is an urgent clinical entity characterised by an increase in the interstitial pressure within a closed osseofascial compartment. Although well recognised as a potential complication after orthopaedic trauma, it is very rarely presented after elective orthopaedic surgery and especially joint arthroplasty. In these rare cases a number of variables are associated with it (positioning, coagulopathy, extensive soft tissue dissection, previous scarring, and epidural analgesia). In this study we present the current evidence with regard to incidence and causation of compartment syndrome after lower limb joint arthroplasty and make recommendations on how to avoid the development of this devastating complication.

Navigated placement of iliac bolts: description of a new technique

Background contextImage navigation has improved the safety and ability to perform complex spinal procedures where visibility is not optimal or anatomic deformity is present. Numerous published studies are available demonstrating its effectiveness in improved pedicle screw placement in complex multiplanar deformities. Studies have also demonstrated image navigation technology versatility; however, stabilization of the lumbopelvic junction with navigated iliac bolt fixation has not been reported. PurposeTo describe an innovative versatile application of image navigation technology in spine surgery. We examine the safety, accuracy, and effectiveness of navigated iliac bolt placement while minimizing challenges associated with current techniques. Study designCase series. Patient sampleFive patients requiring lumbopelvic fixation for multiple indications, including lumbosacral pseudoarthrosis, complex sacral fracture patterns, compromised revision sacral fixation, and as an adjunct to degenerative deformity with multilevel fusion, underwent navigated iliac bolt placement. Outcome measuresAccurate placement was verified using intraoperative computed tomography (CT) imaging using O-ARM (Medtronic, Inc.) after placement. MethodsFive patients requiring lumbopelvic fixation have undergone navigated iliac bolt placement using Medtronic Stealth Station Treon in conjunction with the O-ARM (Medtronic, Inc.). A right percutaneous posterior superior iliac spine (PSIS) reference frame was placed at the superior lateral margin of the PSIS, and bilateral iliac bolts were placed via navigation using both the anatomic and traditional surgical techniques. Both techniques were performed without direct notch palpation and minimal soft-tissue exposure. Postplacement intraoperative CT imaging was obtained to confirm position and trajectory of the bolts using O-ARM (Medtronic, Inc.). ResultsTen iliac bolts were successfully placed in five patients. Intraoperative CT demonstrated ideal iliac screw bone placement projecting within 2 cm over sciatic notch, between pelvic tables. With image navigation, both anatomic and traditional iliac bolt placement techniques were performed with less surgical exposure, no radiation exposure, and complete accuracy using image navigation techniques with a percutaneous reference frame. The percutaneous reference frame placed in the superior lateral PSIS did not cause any interference with our navigated trajectory or bolt. ConclusionsImage-navigated iliac fixation allows for safe and accurate placement of bilateral iliac bolts without PSIS percutaneous reference frame interference. Image guidance eliminates fluoroscopic radiation exposure and extensive soft-tissue dissection and facilitates both traditional and anatomic iliac bolt placement techniques.

Anatomic reconstruction or temporary screw stabilization of chronic symptomatic anterolateral proximal tibiofibular joint instability

Dear Editors, We read with great interest the recent article of Horst and Laprade “Anatomic reconstruction of chronic symptomatic anterolateral proximal tibiofibular joint instability” [2]. The authors are to be complemented on a well-written and well-illustrated report of an operative technique with good results in two cases. The authors conclude that an anatomic reconstruction of the proximal posterior tibiofibular joint may be considered for patients with chronic, symptomatic proximal tibiofibular joint anterolateral subluxation. We would like to place some remarks that we feel should be discussed before accepting the above-mentioned conclusion. We will emphasize as already mentioned by the authors that there are 4 different types of instability, and the most frequent type (67%) is the anterolateral dislocation [4]. This type is mostly caused by a hyperflexion trauma of the knee with plantar flexion and inversion of the foot. In this type of injury, there is a rupture of the posterior and anterior capsular ligament and there could also be an injury of the lateral collateral ligament. These are the main stabilizers of the tibiofibular joint. Ogden identified two variants of the proximal tibiofibular joint, horizontal (coronal plane) and oblique configurations [4, 5]. The horizontal proximal tibiofibular joint lies in the coronal plane and, with a larger articular surface and greater mobility, is more flexible and theoretically more resistant to rotational forces tending to cause fibular dislocation [4, 5]. Peroneal nerve and ankle injuries can occur concomitantly with anterolateral proximal tibiofibular dislocation [10]. Evaluation of the distal syndesmotic ligaments and the interosseous membrane is advisable because the mechanism of trauma can cause a disruption of the distal tibiofibular syndesmosis [3, 10]. In cases of syndesmotic instability, prompt stabilization of the distal tibiofibular joint is advocated [10]. An associated transient peroneal palsy is commonly seen in types II, III, and IV [7, 10]. In more rare cases, disorders at the proximal tibiofibular joint can be a possible cause of referred pain proximally [9]. In the two cases described, 3 months of physical therapy with an emphasis on knee strengthening was ineffective. We would suggest that 6 months is a more appropriate duration of non-operative treatment. We also think there are more non-operative options for patients with chronic instability which can be considered like modifications of a patient’s activity level and training programs, utilization of a supportive strap, lower leg strengthening, and modifications in the lower kinetic chain biomechanics [6]. A supportive strap placed 1 cm below the fibular head can offer relief in many cases. Care should be taken not to apply the strap too tightly or for too long, as this could cause peroneal nerve palsy. The strap should be worn during activities that cause the symptoms [6–8]. Strengthening exercises should consist of: Strengthening of lateral and rotational stability and coordination on a balancing disk or a trampoline. Stretching exercises for m. biceps femoris, m. soleus, and m. gastrocnemius. Strengthening exercises of the peroneal muscles with a dynaband. The affected foot is moved in eversion against the resistance of the band. It is important to avoid activities involving hyperflexion of the knee [1, 6]. We agree with the authors that the ideal treatment for patients requiring surgical intervention has not been well defined. As this is a rare problem, there is a lack of data and no large series are available concerning the outcome of the different treatment possibilities [5]. The reader should also be aware of the technique described in our previous article using screw fixation [8]. The advantage of this technique is that it is much less invasive and less extensive and requires only a minimal incision compared to the technique of the Horst and LaPrade [2] and other ligament reconstructions. For all techniques described, the preliminary results are good, but the surgery is technically demanding, with large incisions and extensive soft tissue dissection and the risk of damaging the common peroneal nerve [10]. We performed a temporary screw fixation (3–6 months) of the proximal tibiofibular joint and a release of the peroneal nerve. In general, the results in our series (>10 athletes) performing this “more simple” technique are good. The disadvantage of this technique is the need for screw removal as it is known that arthrodesis of the proximal tibiofibular joint causes increased rotational forces in the ankle and often leads to pain and instability of the ankle joint [4, 5]. In summary, we agree with Horst and Laprade that an anatomic reconstruction of the proximal posterior tibiofibular joint may be considered for patients with chronic, symptomatic proximal tibiofibular joint anterolateral subluxation, but we think there are other less extensive alternative surgical options. A comparative study should answer this last question. We would be interested to further discuss this with the authors.

Modified hybrid fixator for high-energy Schatzker V and VI tibial plateau fractures

High-energy tibial plateau fractures associated with severe soft tissue injury are difficult to manage. The risk of wound complications following open reduction and internal fixation is notably high owing to extensive soft tissue dissection. Alternatively, application of hybrid external fixator minimizes soft tissue dissection and provides adequate fracture stabilization to allow early range of motion and correction of any mal-alignment. With this technique, soft tissue complications particularly surgical site infections are expected to be significantly reduced. This prospective study aims to determine the effectiveness of a modified hybrid external fixator in the management of high-energy tibial plateau fractures. Thirty-three patients with high-energy Schatzker V and VI tibial plateau fracture with severe soft tissue injury precluding formal open reduction were enrolled into the study. The fixator was a construct combining the Ilizarov ring with a monolateral external fixator. The results—bony union, range of motion, and associated complications of the treatment—were assessed. All fractures united within an average time of 14 weeks. Neither loss of reduction nor surgical site wound breakdown/osteomyelitis was noted. Eight patients developed superficial pin track infection and one septic arthritis of the knee joint. Hybrid external fixation is a safe option for complex high-energy tibial plateau fractures by simultaneously providing adequate fracture stabilization and protection of soft tissue healing to achieve bony union. The complication is mainly related to pin tract infection.

Validità e indicazioni dell’artrodesi di caviglia: artroscopia o a cielo aperto?

Ankle arthrodesis is a technique for the treatment of degenerative joint disorders and diseases. More than 30 open surgical techniques have been employed but in the mid-80s the arthroscopic technique was introduced, being much less invasive than previous procedures and reducing recovery time. We have detailed the arthroscopic technique by comparing results within Authors and, particularly, versus the open technique. From 1995 to 2006 we performed 41 arthroscopic arthrodesis interventions, evaluated by the AOFAS score; medium pre-operative values increased from 21 up to 80 after 6 months’ examination. The arthroscopic technique is undoubtedly useful in performing an invasive intervention such as arthrodesis, allowing a significant reduction of the risks associated to extensive soft tissue dissection and infection

Hasfali sérvek laparoscopos műtéti technikája

Repair of abdominal wall defects is a challenge for all general surgeons and a variety of methods have been described in the past. Traditionally, primary suture repair was shown to have a high recurrence rate in long-term follow-up studies. Herniorrhaphies that apply a large prosthetic mesh are appear to have a lower failure rate, but extensive dissection of soft tissue contributes to an increased incidence of wound infections and wound-related complications. The method of laparoscopic incisional hernia repair was developed in the early 1990s. This technique is based on the same physical and surgical principles as the open underlay procedure. The laparoscopic intraperitoneal onlay mesh (IPOM) technique and mesh materials were developed further in subsequent years, and there have been numerous reports on successful use of the IPOM technique even for extremely large hernia openings in obese and elderly patients. Reduced surgical trauma and lower infection and recurrence rates are key advantages of the minimally invasive repair. Therefore, this operation has increased in popularity promising shorter hospital stay, improved outcome, and fewer complications than traditional open procedures.

Functional and Radiological Evaluations of Unstable Displaced Proximal Humeral Fractures Treated with Closed Reduction and Percutaneous Pinning Fixation

Objective: The purpose of this study is to evaluate the functional and radiological outcomes of patients with unstable displaced proximal humeral fractures treated with closed reduction and percutaneous pinning (CRPP) fixation. Methods: We retrospectively reviewed 87 cases of displaced (2-, 3- or 4-part fractures according to Neer classification) proximal humeral fractures treated with CRPP fixation in our center from September 2003 to September 2008. Sixty-four patients were followed up for a period ranging from 12 to 48 months (averaging 16.2 months) and evaluated for the functional and radiological outcomes by a series of standard questionnaire and measurement. Results: The fractures in all 64 patients were healed with an average time of 15.4 weeks (ranging from 12 to 43 weeks), and the mean interval between the operation and full functional exercise was 17.3 weeks (ranging from 14 to 38 weeks). At the final follow-up visit, no patients showed shoulder instability; the mean range of abduction motion was 157.1° (ranging from 70 to 180°). For all patients, no statistically significant difference in the functional outcomes was observed between their 6-month and final follow-up visits, nor in the radiological findings between their immediately postoperative and fi- nal follow-up examinations. Conclusion: CRPP fixation is a feasible treatment option for unstable displaced proximal humeral fractures, especially for 2- and 3-part fractures in elderly patients. Although technically demanding, it offers reliable stability without extensive soft tissue dissection, allowing the early painless range of motion. This technique could also promote bone healing, prevent ischemic osteonecrosis of the head of humerus and lead to few complications.

Scaphoid AARIF Arthroscopically Assisted Reduction and Internal Fixation of Scaphoid Fractures

The unstable scaphoid fracture can be treated by a variety of different methods including open reduction and internal fixation (ORIF), percutaneous fixation with either K-wires or cannulated screws, and arthroscopic-assisted reduction and internal fixation (AARIF) with various cannulated screw systems. The drawbacks of ORIF include extensive soft-tissue dissection, disruption of the nondominant volar blood supply, division of the radioscaphocapitate and / or radiolunate ligaments and volar capsule, and prolonged rehabilitation. Percutaneous fixation avoids the aforementioned drawbacks yet relies on fluoroscopic guidance alone to ensure accurate reduction of the scaphoid fracture fragments and optimal positioning of the implant in the central third axis of the scaphoid. The frank technical limitations of plain radiography as well as fluoroscopy in detailed visualization of the oddly oriented scaphoid finitely limit the accuracy of the percutaneous technique. AARIF avoids all the limitations of ORIF yet allows direct visualization of the scaphoid fracture site and ensures accurate reduction of the fragments before and during definitive arthroscopically assisted internal fixation. AARIF also assists in accurate targeting of the proximal pole apex or “sweet spot” assuring central third scaphoid axis placement in addition to allowing detection of concurrent pathology in the radiocarpal or midcarpal joints. Scaphoid AARIF is a convenient therapeutic alternative that avoids many of the inherent pitfalls of ORIF and percutaneous fixation.

Reduction and fixation of coronoid fractures by arthroscopic surgery

Objective To investigate the feasibility and methods of arthroscopic reduction and fixation of coronoid fractures. Methods During 2008 and 2009, 6 patients (4 male and 2 female) with coronoid fractures of Regan and Morrey Types Ⅰ and Ⅱ underwent arthroscopic treatment in our department. Their ages ranged from 19 to 34 years, averaging 26. 6 years. Two fractures involved the left side and 4 the right side. By Regan-Morrey classification, 2 were of type Ⅰ and 4 of type Ⅱ. Standard elbow approaches and the exchange rod technique were applied. Compression screws were used to directly fixate the fracture via the anterior median approach. Results One patient was lost to the follow-up. A mean follow-up of 11 months (7 to 24 months) showed that the other 5 patients achieved a functional range of motion with an average flexion/extension of -2°( - 10° to 140°) and full pronation and supination. No patient had elbow instability and neurovascular complications. All the 5 patients had excellent Mayo elbow performance scores. Conclusion Arthroscopic management of coronoid fractures can provide excellent visual fields for anatomic repair without extensive soft tissue dissection and may thus facilitate early rehabilitation. Key words: Arthroscopy; Ulna fractures; Fracture fixation, internal; Bone nails

Complications of definitive open reduction and internal fixation of pilon fractures of the distal tibia

A series of 49 pilon fractures in a tertiary referral centre treated definitively by open reduction and internal fixation have been assessed and the complications of such injuries examined. A retrospective analysis of case notes, radiographs and computerised tomographs over a seven-year period from 1999-2006 was performed. Infection was the most common postoperative problem. There were seven cases of superficial infection. There was a single case of deep infection requiring intravenous antibiotics and removal of metalwork. Other notable complications were those of secondary osteoarthritis (three cases) and malunion (one case). The key finding of this paper is the 2% incidence of deep infection following the direct operative approach to these fractures. The traditional operative approach to such injuries (initially advocated by Rüedi and Allgöwer in Injury 2:92-99, 1969) consisted of extensive soft tissue dissection to gain access to the distal tibia. Our preferred method is to access the tibia via the "direct approach" which involves direct access to the fracture site with minimal disturbance of the soft tissue envelope. We therefore believe that open reduction and internal fixation of pilon fractures via the direct approach to be a safe technique in the treatment of such devastating injuries.

A minimally invasive anterior approach to reduction and screw fixation of coronoid fractures

We investigated a minimally invasive anterior approach to reduce and fix coronoid fractures with a screw in eight consecutive patients and evaluated seven patients at a minimum of 1 year (mean, 78 weeks; range, 61-89 weeks). It was only possible to repair seven of eight coronoid fractures. The average time to radiographic healing was 12 weeks and all healed without the screw loosening, migration or breakage. Endoscopy permitted an excellent view of coronoid fractures, allowing anatomic fixation, and as it avoided extensive soft tissue dissection, this method preserved soft tissue attachments of small coronoid fragments. This method was safe and minimally invasive.

Cleft deformities in adults and children aged over six years in Nigeria: Reasons for late presentation and management challenges

Cleft deformities in adults and children aged over six years in Nigeria: Reasons for late presentation and management challenges Wasiu L Adeyemo1, Mobolanle O Ogunlewe1, Ibironke Desalu2, Akinola L Ladeinde1, Bolaji O Mofikoya3, Michael O Adeyemi4, Adegbenga A Adepoju4, Olufemi O Hassan41Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, 2Department of Anaesthesia, 3Department of Surgery, Faculty of Clinical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria; 4Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Lagos, NigeriaAbstract: In developing countries, untreated cleft lips and palates are found with increasing frequency and patients often present to the surgeon far past the optimal time for closure of the cleft deformities. A prospective study was conducted between March 2007 and September 2009, to identify the reasons and treatment challenges of delayed presentation of cleft lip and palate deformities at the Lagos University Teaching Hospital, Nigeria. Out of a total of 150 patients with cleft defects during the period, 43 (28.7%) were adults and children aged over six years. The mean age of these patients at the time of presentation was 17.3 years. The most common reasons for late presentation were lack of money (56.7%), lack of health care services nearby (18.4%), and lack of awareness of treatment availability (13.3%). Common challenges in these patients included surgical, orthodontic, speech, anesthetic, and psychological. Although adult clefts were significantly enlarged in three dimensions the anatomic landmarks were easier to discern than in an infant. However, extensive soft tissue dissection in adult cleft lip repair resulted in significant postoperative edema. Closure of wide palatal cleft often required the use of adjunct intraoral flaps. Despite late presentation, surgical outcome of these patients was satisfactory and comparable to cleft repair in infants.Keywords: cleft deformities, adults, adolescents, late presentation, management, challenges

Cleft deformities in adults and children aged over six years in Nigeria: Reasons for late presentation and management challenges

In developing countries, untreated cleft lips and palates are found with increasing frequency and patients often present to the surgeon far past the optimal time for closure of the cleft deformities. A prospective study was conducted between March 2007 and September 2009, to identify the reasons and treatment challenges of delayed presentation of cleft lip and palate deformities at the Lagos University Teaching Hospital, Nigeria. Out of a total of 150 patients with cleft defects during the period, 43 (28.7%) were adults and children aged over six years. The mean age of these patients at the time of presentation was 17.3 years. The most common reasons for late presentation were lack of money (56.7%), lack of health care services nearby (18.4%), and lack of awareness of treatment availability (13.3%). Common challenges in these patients included surgical, orthodontic, speech, anesthetic, and psychological. Although adult clefts were significantly enlarged in three dimensions the anatomic landmarks were easier to discern than in an infant. However, extensive soft tissue dissection in adult cleft lip repair resulted in significant postoperative edema. Closure of wide palatal cleft often required the use of adjunct intraoral flaps. Despite late presentation, surgical outcome of these patients was satisfactory and comparable to cleft repair in infants.

Anterior plating as a surgical alternative in the treatment of humeral shaft non-union

This study included 15 patients with humeral shaft fractures who had no clinical, radiological or bone scan signs of healing after eight months. The patients were followed for a mean of 35.8 months. No patient was lost to follow-up. Anterior plating of humeral shaft nonunion via an anterior approach was performed using a straight plate and compression for well-vascularised non-unions and wave plating with a tricortical graft for poorly vascularised non-unions. All non-unions healed within 6-18 weeks (mean, nine weeks) without local complication. One patient had a mild decrease in elbow and shoulder range of motion. No neurovascular injury was observed. Anterior plating is a simple, safe and effective treatment for humeral shaft non-union. As this approach avoids the need for radial nerve visualisation and extensive soft-tissue dissection, and the healing time is similar to that of other methods, we suggest this treatment as an alternative option.

Functional and radiological evaluations of high-energy tibial plateau fractures treated with doublebuttress plate fixation

ObjectiveThis study was designed to evaluate the functional and radiological outcomes of patients with complex tibial plateau fractures treated with double-buttress plate fixation.MethodsSixty five cases of complex (Schatzker type V and VI) tibial plateau fractures were treated with double-buttress plate fixation in our centre from September 2001 to September 2006 through two separate plate incisions. Fifty four patients were followed up for a period ranging from 12 to 48 months and evaluated for the functional and radiological outcomes by a series of standard questionnaire and measurement.ResultsDue to the good exposure without any extensive soft-tissue dissection of the double-buttress plate fixation, the fractures in all 54 patients were healed and the treatment achieved greater than 90% of satisfactory-to-excellent rates of reduction. The mean time of bone union was 15.4 weeks (range, 12-30 weeks), and the mean time of full weight-bearing was 18.7 weeks (range, 14-26 weeks). At the final follow-up visit, no patients showed knee instability; the mean range of motion was 107.6° (range, 85°-130°). For all patients, no statistically significant difference in the functional outcomes was observed between their 6-months and final follow-up visits; or in the radiological findings between their immediate postoperative and final follow-up examinations.ConclusionDouble-buttress plate fixation is a feasible treatment option for bilcondylar and complex tibial plateau fractures. Although technically demanding, it offers reliable stability without additional postoperative adjuvant external fixation, and at the same time avoids extensive soft tissue dissection, allowing the early painless range of motion.

Arthroscopically Assisted Coronoid Fracture Fixation: A Preliminary Report

We investigated the feasibility of arthroscopically assisted reduction and fixation of small coronoid fractures and the anterior capsule for treatment of patients with Regan and Morrey Types I and II (O'Driscoll Types I and II) coronoid fractures with instability of the ulnohumeral joint. Four consecutive patients with this fracture type underwent arthroscopically assisted treatment and were evaluated at a minimum of 1 year (mean, 76 weeks; range, 58-92 weeks). All patients achieved a functional range of motion with an average flexion/extension arc of 2.5 degrees to 140 degrees and full pronation and supination. No patient had recurrent elbow instability. One patient had removal of a prominent suture over the subcutaneous border of the ulna. Arthroscopically assisted management of coronoid fractures can provide excellent observation, enabling anatomic repair without extensive soft tissue dissection. Preservation of the soft tissue attachments of small coronoid fragments and repair of the capsule are possible with this technique. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

A Modified Technique of Arthroscopically Assisted AC Joint Reconstruction and Preliminary Results

Surgical treatment of high-grade acromioclavicular (AC) joint separations has become analogous to ligament reconstructions elsewhere in the body with the goal being restoration of the native anatomy. Circumferential access to the base of the coracoid is essential to reconstruct the coracoclavicular ligament complex. Using some of the traditional open approaches, this access requires detaching the deltoid insertion and performing extensive soft tissue dissection. Also, poor visualization risks injury to nearby neurovascular structures. An arthroscopically assisted reconstruction offers the advantage of less soft tissue dissection and superior visualization to the base of the coracoid. We have developed a unique arthroscopically assisted technique that uses a subacromial approach to pass suture material and a tendon graft around the coracoid to reconstruct the coracoclavicular ligament complex. We describe our technique and preliminary results in 10 patients who have undergone coracoclavicular ligament reconstruction for high-grade AC separation. All patients improved subjectively with regard to pain and function at a minimum followup of 3 months (mean, 5 months; range, 3-18 months). This arthroscopically assisted technique has the potential to allow for safe and at least in the short term reliable restoration of the coracoclavicular ligament complex and provides an alternative technique to treat AC joint separations.

Accuracy of navigated surgery of the pelvis after surface matching with an a‐mode ultrasound probe

Computer-aided surgery (CAS) allows for real-time intraoperative feedback resulting in increased accuracy, while reducing intraoperative radiation. CAS is especially useful for the treatment of certain pelvic ring fractures, which necessitate the precise placement of screws. Flouroscopy-based CAS modules have been developed for many orthopedic applications. The integration of the isocentric flouroscope even enables navigation using intraoperatively acquired three-dimensional (3D) data, though the scan volume and imaging quality are limited. Complicated and comprehensive pathologies in regions like the pelvis can necessitate a CT-based navigation system because of its larger field of view. To be accurate, the patient's anatomy must be registered and matched with the virtual object (CT data). The actual precision within the region of interest depends on the area of the bone where surface matching is performed. Conventional surface matching with a solid pointer requires extensive soft tissue dissection. This contradicts the primary purpose of CAS as a minimally invasive alternative to conventional surgical techniques. We therefore integrated an a-mode ultrasound pointer into the process of surface matching for pelvic surgery and compared it to the conventional method. Accuracy measurements were made in two pelvic models: a foam model submerged in water and one with attached porcine muscle tissue. Three different tissue depths were selected based on CT scans of 30 human pelves. The ultrasound pointer allowed for registration of virtually any point on the pelvis. This method of surface matching could be successfully integrated into CAS of the pelvis.

Endoscopic bone grafting for management of nonunion of the tuberosity avulsion fracture of the fifth metatarsal

The most common fracture of the proximal fifth metatarsal is the tuberosity avulsion fracture. Most of the time, the fracture is relatively undisplaced and it can be treated conservatively with a hard-soled shoe or walking cast. For painful intra-articular nonunion, internal fixation with or without bone graft is the treatment of choice. We describe an endoscopic approach to treat nonunions of the tuberosity avulsion fracture. Under endoscopic guidance, the nonunion site can be debrided thoroughly and bone grafted without the need of extensive soft tissue dissection. Moreover, the condition of the fifth metatarsal cuboid articulation can be assessed and intra-articular pathology can be dealed with arthroscopically. Finally, the desired position of the screw can be guided by the arthroscopic aiming device.