Bone Scintigraphy: A Review of Technical Aspects and Applications in Orthopedic Surgery.

Due to its high sensitivity, low cost, accessibility, and ease of use, bone scintigraphy is used in orthopedic surgery for the diagnosis and management of varied pathology. It is commonly used for insufficiency fractures, metastatic neoplasia, staging and surveillance of sarcoma, and nonaccidental trauma. It augments diagnoses, including stress or occult fractures, musculoskeletal neoplasia or infection, and chronic regional pain syndrome, in patients presenting with normal results on radiographs. Bone scan images are resistant to metal-based implant artifact, allowing effective evaluation of failed total joint prostheses. Bone scintigraphy remains an underused tool in the evaluation and management of orthopedic patients. [Orthopedics. 2019; 42(1):e14-e24.].

Surgical management of metastatic disease of the proximal part of the femur.

➤ Pathologic fracture of the proximal part of the femur resulting from metastatic disease causes severe pain and an inability to walk. Surgical stabilization can be challenging because of bone loss resulting from the underlying metastatic lesions, the potential for major blood loss, and the poor health of the patient.➤ The goal of surgical treatment is the creation of a stable construct to allow early weight-bearing.➤ Pathologic femoral neck fractures secondary to metastases are best managed with arthroplasty.➤ The treatment of intertrochanteric or subtrochanteric fractures is more controversial. Surgical stabilization may be performed with cephalomedullary nailing or arthroplasty. The choice of implant and operative technique is dependent on careful consideration of multiple factors, including the patient's life span, the type of tumor, the perceived response to other therapies, the need for adjuvant radiation therapy and chemotherapy, the location and number of metastatic lesions, and the degree of bone involvement.➤ While the potential for complications is high, surgical stabilization of the proximal part of the femur decreases pain and improves function.

The axial transsacral approach to interbody fusion at L5-S1.

Lumbosacral interbody fusion may be indicated to treat degenerative disc disease at L5-S1, instability or spondylolisthesis at that level, and severe neural foraminal stenosis resulting from loss of disc space height. In addition, L5-S1 interbody fusion may provide anterior support to a long posterior fusion construct and help offset the stresses experienced by the distal-most screws. There are 3 well-established techniques for L5-S1 interbody fusion: anterior lumbar interbody fusion, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion. Each of these has advantages and pitfalls. A more recently described axial transsacral technique, utilizing the presacral corridor, may represent a minimally invasive approach to obtaining lumbosacral interbody arthrodesis. Biomechanical studies demonstrate that the stiffness of the axial rod is comparable to existing fixation devices, suggesting that, biomechanically, it may be a good implant for obtaining lumbosacral interbody fusion. Clinical studies have demonstrated good early results with the use of the axial transsacral approach in obtaining lumbosacral interbody fusion for degenerative disc disease, spondylolisthesis, and below long posterior fusion constructs. The technique is exacting and complications can be major, including rectal perforation and fistula, loss of correction, and pseudarthrosis.

Management of metastatic bone disease of the acetabulum.

Metastatic acetabular disease can be severely painful and may result in loss of mobility. Initial management may consist of diphosphonates, narcotic analgesics, radiation therapy, protected weight bearing, cementoplasty, and radiofrequency ablation. Patients with disease affecting large weight-bearing regions of the acetabulum and with impending failure of the hip joint are unlikely to gain much relief from nonsurgical treatment and interventional procedures. The profound osteopenia of the acetabulum, limited healing potential of the fracture, and projected patient life span and function necessitate surgical techniques that provide immediate stable fixation to reduce pain and restore ambulatory function. Current reconstructive procedures, including cemented total hip arthroplasty, the saddle or periacetabular endoprosthesis, and porous tantalum implants, are based on the quality of remaining acetabular bone as well as the patient's level of function and general health. Well-executed acetabular reconstructions can provide durable hip joints with good pain relief and function.

Influence of surgical experience on the efficiency of discectomy in TLIF: a cadaveric testing in 40 levels.

STUDY DESIGN: Cadaveric study. OBJECTIVE: The purpose of this study was to assess the influence of surgical experience on the efficiency of lumbar discectomy in open transforaminal lumbar interbody fusion. SUMMARY OF BACKGROUND DATA: There is limited knowledge about the efficiency of discectomy among surgeons. As a first study, we are evaluating the effect of surgical experience on it. METHODS: Manual and powered discectomies were randomized and performed by 3 attending spine surgeons and 2 clinical spine fellows. Each discectomy procedure was analyzed for the area of complete endplate preparation, total elapsed time, and number of instrument passes. The surface area of discectomy at each endplate was measured utilizing digital imaging and the appropriate software. For the purpose of the analysis, the superior and the inferior endplates were divided into ipsilateral and contralateral halves, and each half was further divided into ventral and dorsal quadrants. Each quadrant was analyzed in a blinded manner by 2 observers. RESULTS: A total of 40 discectomies were performed on 9 fresh-frozen cadaveric torsos between the levels T12 and S1. A powered discectomy device was used in levels 9 and 11 by the attendings. Manual discectomy was performed in 11 levels by the spine fellows and 9 by the spine attendings. No significant difference was observed between the spine fellows and spine attendings when the manual instruments were used (P = 0.924). However, the spine attending surgeon group had a significantly increased total area of discectomy compared with the fellows (P = 0.003). No significant difference was observed between the groups when instrument passes or the total elapsed time were compared either utilizing the manual or the powered technique. CONCLUSIONS: Our results demonstrate that a satisfactory discectomy may be performed by surgeons with relatively less surgical experience in the transforaminal approach using a powered discectomy device.

Intramedullary rod and cement static spacer construct in chronically infected total knee arthroplasty.

Two-stage reimplantation, with interval antibiotic-impregnated cement spacer, is the preferred treatment of prosthetic knee joint infections. In medically compromised hosts with prior failed surgeries, the outcomes are poor. Articulating spacers in such patients render the knee unstable; static spacers have risks of dislocation and extensor mechanism injury. We examined 58 infected total knee arthroplasties with extensive bone and soft tissue loss, treated with resection arthroplasty and intramedullary tibiofemoral rod and antibiotic-laden cement spacer. Thirty-seven patients underwent delayed reimplantation. Most patients (83.8%) were free from recurrent infection at mean follow-up of 29.4 months. Reinfection occurred in 16.2%, which required debridement. Twenty-one patients with poor operative risks remained with the spacer for 11.4 months. All patients, during spacer phase, had brace-free ambulation with simulated tibiofemoral fusion, without bone loss or loss of limb length.

Conventional manual discectomy versus powered discectomy for interbody fusion in the lumbar spine: cadaveric testing in forty levels.

STUDY DESIGN: A discectomy study on human cadaveric lumbar spine. OBJECTIVE: The purpose of this study was to assess the efficacy of manual versus powered discectomies using a transforaminal lumbar interbody fusion approach. SUMMARY OF BACKGROUND DATA: To achieve fusion, removal of nucleus tissue and endplate cartilage is essential for preparation of the interbody space. Quantitatively, it has been established that maximal structural graft or implant coverage of the endplates are of critical importance for fusion and subsidence prevention. METHODS: Twenty levels underwent conventional manual discectomy (group 1) and 20 underwent powered discectomy (group 2) by 3 attending spine surgeons and 2 spine fellows. Each discectomy procedure was analyzed for time and number of instrument passes. Postoperatively, each level was measured grossly and digitally for percentage of appropriate discectomy and endplate preparation. For analysis, the superior and inferior endplate surfaces were divided into ipsilateral and contralateral halves, and ventral and dorsal halves. Each quadrant was then analyzed separately. RESULTS: A total of 40 discectomies on 9 fresh-frozen cadaver torsos between T12-L1 and L5-S1 were performed in this study. Within each quadrant, the discectomized area was greater in group 2 than in group 1. The largest difference was observed on the contralateral ventral quadrant, group 1 (38.2%) and group 2 (52.4%), respectively (P = 0.012). Average procedure time was also significantly less in group 2 versus group 1 (P = 0.009). Group 2 had an overall increased discectomy and appropriately prepared endplates (46.8%) compared with group 1 (36.3%) (P = 0.025). Significantly fewer instrument passes were seen in group 2 versus group 1 (P < 0.001). Two iatrogenic endplate fractures were observed in group 1 and 1 in group 2. CONCLUSIONS: In addition to a significantly superior discectomy efficacy, the group 2 had significantly fewer instrument passes and shorter procedure times. In vivo studies are required to further evaluate the differences and cost benefit of this innovative tool.

A 17-year follow-up of modified "Harrington" reconstruction after acetabular resection.

Acetabular reconstruction after resection of advanced periacetabular metastatic lesion is a complex undertaking. Harrington (J Bone Joint Surg [Am]. 1981;63-653) described a reconstructive technique in class III- and IV-type resections using threaded Steinmann pins and acrylic cement. This technique, although effective for pain relief and restoration of function, is traditionally considered when patient's life expectancy is short because of its questionable durability. A 17-year follow-up of our patient with plasma cell cytoma of the ilium and acetabulum, treated with a modification of the above technique after intralesional curettage, showed no mechanical failure or loosening. This suggests that the construct can be durable where there is no recurrence of disease and can also be a valuable asset in selected nontumor cases in adjunct to contemporary techniques.