Computer-assisted fluoroscopic navigation of percutaneous spinal interventions

Purpose

Percutaneous spine procedures may occasionally be difficult and subject to complications. Navigation using a dynamic reference base (DRB) may ease the procedure. Yet, besides other shortcomings, its fixation demands additional incisions and thereby defies the percutaneous character of the procedure.

Methods

A new concept of atraumatic referencing was invented including a special epiDRB. The accuracy of navigated needle placement in soft tissue and bone was experimentally scrutinised. Axial and pin-point deviations from the planned trajectory were investigated with a CT-based 3D computer system. Clinical evaluation in a series of ten patients was also done.

Results

The new epiDRB proved convenient and reliable. Its fixation to the skin with adhesive foil provided a stable reference for navigation that improves the workflow of percutaneous interventions, reduces radiation exposure and helps avoid complications.

Conclusions

Percutaneous spine interventions can be safely and accurately navigated using epiDRB with minimal trauma or radiation exposure and without additional skin incisions.     

Arthroscopic debridement and drilling of osteochondral lesions of the talus

Diagnosis of OLTs requires a high index of suspicion because these lesions are rare and the symptoms can be falsely attributed to acute or chronic ankle sprains. When no abnormality is present on plain radiographs, a bone scan or MRI can reliably identify the presence of an OLT. CT scanning can provide even better detail of the location and size of the fragment and help stage these lesions and guide treatment. Arthroscopic staging is believed to be the best method to determine treatment. In a patient without an obvious loose body, initial nonoperative treatment is warranted. When nonoperative therapy fails or when a high stage lesion is present, operative options should be explored. Arthroscopic techniques provide results that are equal to or better than management by arthrotomy and have the advantages of lower morbidity and quicker overall rehabilitation time. In most cases, arthroscopic treatment involves loose body removal and debridement and drilling of the underlying bone or drilling alone for intact lesions. Although it is unknown whether such treatment can reduce the incidence of late arthrosis in a patient who has an OLT, a recent study suggested that healing occurs and the MRI appearance of the talar dome normalizes in many patients postoperatively.     

Arthroscopic drilling for the treatment of osteochondral lesions of the talus.

BACKGROUND: An osteochondral lesion of the talus is a relatively rare disorder of the ankle. While a number of treatment options have been reported, it appears to be difficult to manage all lesions with a single approach. We evaluated the indications for and the results of arthroscopic drilling for the treatment of an osteochondral lesion of the talus. METHODS: Eighteen ankles (seventeen patients) with a symptomatic osteochondral lesion of the talus were examined. The ages of the patients ranged from ten to seventy-eight years (mean, 28.0 years) at the time of the operation, and the patients were followed postoperatively for two to 9.5 years (mean, 4.6 years). After the continuity of the cartilage overlying the lesion and the stability of the lesion had been confirmed, arthroscopic drilling was performed with use of a Kirschner wire that was 1.0 to 1.2 millimeters in diameter. A cast was not applied postoperatively, and full weight-bearing was allowed six weeks after the procedure. RESULTS: The clinical result was good for thirteen ankles and fair for five; all ankles had improvement. Twelve of the thirteen ankles that were in patients who were less than thirty years old had a good result. In contrast, only one of the five ankles in patients who were fifty years old or more had a good result. Thus, the clinical results tended to be better for younger patients. Improvement was seen radiographically in fifteen ankles. However, the three ankles in patients who were more than sixty years old were found to have no improvement on radiographic examination. Analysis of the group of patients who had a history of trauma revealed that the mean interval between the injury and the operation was 6.3 months for the three ankles that had a good radiographic result and 11.3 months for the six that had a fair result. Thus, the radiographic results tended to be better when the interval between the injury and the operation was shorter. CONCLUSIONS: Arthroscopic drilling for the treatment of medial osteochondral lesions of the talus does not require osteotomy of the medial malleolus or postoperative immobilization; thus, the procedure is less invasive than other types of operative treatment for the condition and it allows early resumption of daily activities and sports. On the basis of the results in this study, we believe that the procedure is effective and useful in young patients, especially those who have not yet had closure of the epiphyseal plate. A specific indication for the procedure is an early lesion with only mild osteosclerosis of the surrounding talar bone, continuity of the cartilaginous surface, and stability of the osteochondral fragment.     

Fluoroscopy-guided retrograde core drilling and cancellous bone grafting in osteochondral defects of the talus

Purpose

In undetached osteochondral lesions (OCL) of the talus both revitalisation of the subchondral necrosis and cartilage preservation are essential. For these cases, we assess the results of minimally invasive retrograde core drilling and cancellous bone grafting.

Methods

Forty-one osteochondral lesions of the talus (12x grade I, 22x grade II and 7x grade III according to the Pritsch classification, defect sizes 7–14 mm) in 38 patients (mean age 33.2 years) treated by fluoroscopy-guided retrograde core drilling and autologous cancellous bone grafting were evaluated by clinical scores and MRI. The mean follow-up was 29.0 (±13) months.

Results

The AOFAS score increased significantly from 47.3 (±15.3) to 80.8 (±18.6) points. Lesions with intact cartilage (grades I and II) had a tendency to superior results than grade III lesions (83.1 ± 17.3 vs. 69.4 ± 22.2 points, p = 0.07). First-line treatments and open distal tibial growth plates led to significantly better outcomes (each p < 0.05). Age, gender, BMI, time to follow-up, defect localisation or a traumatic origin did not influence the score results. On a visual analogue scale pain intensity reduced from 7.5 (±1.5) to 3.7 (±2.6) while subjective function increased from 4.6 (±2.0) to 8.2 (±2.3) (each p < 0.001). In MRI follow-ups, five of the 41 patients showed a complete bone remodelling. In two cases demarcation was detectable.

Conclusions

The technique reported is a highly effective therapeutic option in OCL of the talus with intact cartilage grades I and II. However, second-line treatments and grade III lesions with cracked cartilage surface can not be generally recommended for this procedure.     

影像导航引导椎体成形术在治疗胸腰段椎体爆裂骨折中的应用

目的 探讨影像导航系统引导椎体成形术辅助短节段椎弓钉内固定在治疗胸腰段椎体爆裂骨折中的有效性和效果.方法 对28例胸腰段椎体爆裂骨折采用导航引导下的短节段椎弓钉固定结合钙磷骨水泥灌注椎体成形术,内植完成后即行X线片正侧位摄片与导航路径进行吻合测量.结果 本组患者术后内植物位置理想,椎弓钉位置评级:理想106枚(94.5%),6枚突破椎弓根外侧皮质(5%),Ⅱ级2枚.术后1周离床负重行走.椎体高度丢失恢复40%,随访12个月后显示椎体高度平均改变0.2%,过伸过屈动力摄片显示固定段无异常活动,未发现有椎弓钉松动、断裂病例.结论 导航引导椎弓钉植入及钙磷骨水泥灌注椎体成形术,只需1次X线片成像就能做出虚拟的手术环境和路径;使内植物精确植入最佳位置,提高了椎弓钉植入及椎体成形手术的安全性,提高手术疗效.     

Computer-assisted fluoroscopic navigation system for removal of distal femoral bone cement in revision total hip arthroplasty

Removal of the femoral bone cement in revision total hip arthroplasty with a high-powered drill or burr potentially has a risk of damage to the bone, resulting in perforation and fracture of the femur. Recently, we have used a computer-assisted fluoroscopic navigation system for the revision of cemented total hip arthroplasty with a high-powered burr and completely removed the distal femoral bone cement with no complications in 6 cases. Thus, a computer-assisted fluoroscopic navigation system is a useful tool for the improvement of the surgical technique in revision total hip arthroplasty.     

Transtalar retrograde drilling of medial osteochondral lesions of the talar dome

Osteochondral lesions of the medial talar dome can cause prolonged ankle disability. Chronic symptomatic lesionshave traditionally been debrided with transarticular approaches using arthrotomy, malleolar osteotomy, or arthroscopy. All of these techniques require removal of cartilage to access the underlying bone. The use of arthroscopy combined with percutaneous retrograde transtalar drilling through the sinus tarsi allows healing of the bone lesion and sparing of intact articular cartilage. Short-term results have shown high patient satisfaction.     

Osteochondral lesions of the talus

Osteochondral lesions of the talus (OLT) are rare joint disorders. The talus is the third most common location of this disorder, following the knee and elbow joints. OLT represents 4% of all osteochondral lesions in the body. This article discusses the surgical treatment and postoperative rehabilitation of osteochondral lesions of the talus.     

Osteochondral lesions of the talus

Osteochondral lesions of the talus occur infrequently and usually represent late sequelae of ankle trauma. Because of the functional significance of the talus and its limited capacity for repair, correct early diagnosis is important. Osteochondral fractures should be suspected in patients with chronic ankle pain, especially those with a prior ankle injury. Historically, plain radiographs have been used to stage lesions; more recently, magnetic resonance imaging and arthroscopy have been used. Non-surgical management remains the mainstay of treatment of acute, nondisplaced osteochondral lesions. Surgical management is reserved for unstable fragments or failure of nonsurgical treatment. Recent advances in osteochondral grafting have allowed reconstruction of the talar dome, leading to more predictable relief of pain and improvement of function.     

Osteochondral lesions of the talus

Background and purpose — The frequency of progression of osteoarthritis and persistence of symptoms in untreated osteochondral lesion of the talus (OCL) is not well known. We report the outcome of a nonoperative treatment for symptomatic OCL.

Patients and methods — This study included 142 patients with OCLs from 2003 to 2013. The patients did not undergo immobilization and had no restrictions of physical activities. The mean follow-up time was 6 (3–10) years. Initial MRI and CT confirmed OCL and showed lesion size, location, and stage of the lesion. Progression of osteoarthritis was evaluated by standing radiographs. In 83 patients, CT was performed at the final follow-up for analyses of the lesion size. We surveyed patients for limitations of sports activity, and Visual Analogue Scales (VAS), AOFAS, and SF-36 were assessed.

Results — No patients had progression of osteoarthritis. The lesion size as determined by CT did not change in 69/83 patients, decreased in 5, and increased in 9. The mean VAS score of the 142 patients decreased from 3.8 to 0.9 (p < 0.001), the mean AOFAS ankle–hindfoot score increased from 86 to 93 (p < 0.001), and the mean SF-36 score increased from 52 to 72 (p < 0.001). Only 9 patients reported limitations of sports activity. The size and location of the lesion did not correlate with any of the outcome scores.

Interpretation — Nonoperative treatment can be considered a good option for patients with OCL.     

Osteochondral lesions of the talus

Osteochondral lesions occur either as osteochondral fractures (so called flake fractures) or osteochondritis dissecans. Both types of lesions are caused in the most of the cases by an adequate trauma. The injury is sustained during inversion of the ankle. If the foot is dorsiflexed, an anterolateral lesion will result from shearing forces by the fibula. If the inversed foot is plantar flexed and followed by rotation of the tibia on the talus, a postero-medial lesion will result from compression of the medial talar dome by the tibia, secondary to spiralling and shortening of the collateral ligaments. The diagnosis is suspected with the most common complaints of the patients to pain on weight bearing or during sports, swelling, crepitus, giving way or locking ankle after an inversion injury. In case of negative standard X-rays and doubtful clinical findings tomograms in the AP and lateral views or even a scintigraphy of both ankles ar indicated. 15 patients with osteochondral lesions were treated, 7 with an antero-lateral transchondral fracture and 8 with a poster-medial osteochondritis dissecans. The lesions were classified after Berndt and Harty and differentiated between type I-IV. 13 patients have been operated, 4 by arthroscopy. The mean follow-up time of the clinical and radiographic examination was 1 year. The results were evaluated by a point score system. 7 patients (46.6%) had good, 5 (33.3%) a fair and 3 (20%) a poor result.(ABSTRACT TRUNCATED AT 250 WORDS)     

关节镜下钻孔术与微骨折锥术治疗距骨骨软骨损伤的疗效比较

目的比较关节镜下克氏针钻孔术和微骨折锥术治疗小面积距骨骨软骨损伤的疗效。方法回顾性研究自中山大学孙逸仙纪念医院骨科2014年2月至2017年6月收治的57例小面积距骨骨软骨损伤患者资料,根据治疗方法不同分为两组:钻孔组(关节镜下克氏针钻孔术治疗)26例,男15例,女11例;年龄20~57岁;损伤面积0.6~1.4 cm^2;根据Berndt和Harty基于X线片的踝关节骨软骨损伤分期标准:Ⅰ期9例,Ⅱ期8例,Ⅲ期6例,Ⅳ期3例。微骨折组(关节镜下微骨折锥术治疗)31例,男17例,女14例;年龄24~55岁;损伤面积0.5~1.5 cm^2;Berndt和Harty的踝关节骨软骨损伤分期:Ⅰ期10例,Ⅱ期11例,Ⅲ期8例,Ⅳ期2例。通过比较末次随访时的视觉模拟评分(VAS)、美国足踝外科协会(AOFAS)的踝-后足评分、踝关节运动评分(AAS)和Berndt和Harty提出的距骨骨软骨损伤分期评价手术疗效。结果57例患者术后获13~27个月随访。所有患者末次随访时的VAS评分、AOFAS评分、AAS评分、Berndt和Harty提出的距骨骨软骨损伤分级均较术前改善,差异有统计学意义(P<0.05)。末次随访时两组患者的VAS评分[(2.2±1.6)、(2.1±1.4)分]、AOFAS评分[(89.1±6.3)、(90.4±5.8)分]、AAS评分(6、6分)比较差异均无统计学意义(P>0.05)。末次随访时两组患者AOFAS的踝-后足评分优良率分别为88.5%(23/26)和90.3%(28/31),差异无统计学意义(χ^2=0.052,P=0.820)。结论关节镜下克氏针钻孔术和微骨折锥术在治疗小面积距骨骨软骨损伤中均能取得满意的近期疗效,且疗效基本相似,远期疗效有待进一步研究。     

Imaging of osteochondral lesions of the talus

A review of the literature reveals that all studies have been performed retrospectively. These studies have included limited numbers of low-grade lesions and no prospective, randomized, comparison studies have been performed to suggest the superiority of CT scanning over MR imaging. The following conclusions, however, can be made. Plain radiographs are useful in the initial evaluation of patients with acute or chronic complaints of ankle pain and swelling. These initial studies, however, may not identify all osteochondral lesions of the talus, particularly lower grade lesions. CT scanning can accurately identify and localize a lesion while defining its extent. It has been suggested that CT scanning can be used to assess whether bony healing has occurred at follow-up. MR imaging can also precisely identify, localize, and define an OLT with the advantage of assessing the integrity of the overlying cartilage. It can detect lower grade lesions with improved sensitivity and may aid in the differentiation of Stage II and Stage III lesions. Using the preceding observations, the following approach is recommended in the evaluation and work-up of an osteochondral lesion of the talus (Fig. 7). The patient who presents with ankle pain and swelling should have weight-bearing radiographs of the ankle obtained. If these films demonstrate an osteochondral lesion of the talus, staging of the lesion should be performed. In lesions that appear nondisplaced on plain radiography (low grade; stable), MR imaging is recommended so the clinician can evaluate the integrity of the overlying cartilage and assess the true stability of the lesion. In lesions that appear displaced on plain radiography (high grade; unstable), the CT scan is the preferred modality in order to provide accurate assessment of lesion size and location. It should be noted, however, that no study has prospectively [figure: see text] compared the efficacy of these two modalities in the evaluation of osteochondral lesions. If a symptomatic patient presents with negative plain films, then an initial period of immobilization using a cast or boot brace is recommended. This is followed by joint mobilization and range of motion exercises. If the patient remains symptomatic at the 4 to 6 week followup period, then an MR image should be performed. This study provides information regarding soft-tissue impingement, proliferative synovitis, and other bony and soft-tissue pathology. The authors have found that despite the results of bone scintigraphy, an MR image is invariably obtained. Because of this the authors do not recommend bone scintigraphy in the evaluation and diagnosis of OLT.     

Osteochondral lesions of the talus in adolescents

Osteochondral lesions of the talus range from those confined to the hyaline cartilage covering the articular surface to those involving the subchondral bone. The lesion may not be apparent on the surface of the cartilage or it may be confined to the subchondral bone without cartilage involvement. These complex presentations often necessitates the use of computed tomography and magnetic resonance imaging to delineate the exact nature of the lesions. It has been shown that the frequency of osteochondral lesions increase following repetitive ankle sprains. Although the etiology is not well understood, both traumatic and atraumatic causes are thought to be effective. Nevertheless, early diagnosis and treatment of these lesions have improved considerably thanks to the developments in imaging techniques. It seems that arthroscopic chondral reconstruction methods using autologous chondrocyte and osteochondral transplantations will gain much interest in the near future.     

Computer-assisted FluoroGuide navigation of unicompartmental knee arthroplasty

Background

Most authorities recognize minimally invasive unicompartmental knee arthroplasty (UKA) as technically demanding with concerns regarding loss of implantation accuracy. We have previously reported on the potential inaccuracy of femoral intramedullary guides in UKA leading to poor component positioning. Our 3-dimensional analysis of alignment error showed that a short, narrow intramedullary rod inserted according to the manufacturer’s specifications did not accurately find the direction of the anatomic axis, with errors occurring in both the coronal and sagittal planes. We sought to evaluate whether a fluoroscopic computer-assisted minimally invasive UKA procedure would improve the accuracy and precision in the placement of the femoral component in the coronal and sagittal planes compared with conventional surgery.

Methods

We performed a prospective study involving cohorts of 45 conventional versus 53 navigated UKAs. A single surgeon performed all surgeries over a 4-year period.

Results

Pain and knee function significantly improved in both surgical groups at 1 and 2 years after surgery. At a minimum of 1-year follow-up, radiographic evaluation revealed significant improvements in coronal alignment precision of the tibial component (p = 0.026) and sagittal alignment precision of the femoral component for the navigated group (p = 0.037). The use of a fluoroscopic computer-assisted technique did not significantly improve the accuracy of any of the alignment angles.

Conclusion

We cannot justify the additional expense and complexity imposed by fluoroscopic navigation despite the observed improvements in alignment precision. Improved positioning precision may translate into a greater number of long-term functional results, but larger, longer-term studies are needed.