Aging degenerative deformities are complex situations [35]. With them, postural problems are very common. A central or foraminal stenosis often coexists [36]. Traditional open surgery with long posterior stabilization is related with a major complication risk [37, 38].

Lateral interbody fusion through a transpsoas approach has been shown to be extremely effective in deformity correction by a less invasive technique [39, 40]. In the osteoporotic spine, however, the issues are related to cage subsidence and secondary loss of correction [40, 41]. Prophylactic cement reinforcement can help to overcome this limitation and provide sufficient support for the cages [40]. There is a need for aggressive cement filling. The vertebroplasty procedure can be performed in the same session prior to the lateral correction or as a staged procedure. The latter strategy is the one preferred by the author, especially when multiple vertebrae are to be treated. The intervention is performed under local anesthesia/sedation. In multiple-level cases, two sessions are required, as the amount of cement should not exceed 30 cc in one session due to the risk of fat embolism. The main procedure consists of the scoliosis correction using a mini-open lateral approach. The technique aims to be a stand-alone procedure as long as the rotational deformity remains moderate (Fig. 26.2). Otherwise additional posterior percutaneous screw fixation is performed in combination with cement-reinforced screws.

We studied 60 cases operated through a lateral approach for degenerative deformities (scoliosis/loss of lordosis) in patients with osteoporosis treated with vertebroplasty and segmental correction. Seven patients underwent an additional posterior percutaneous stabilization within the first 3 months after the lateral intervention due to secondary loss of correction. The clinical outcomes were encouraging. However, 60 % of patients did note approach-related discomfort and side effects in the early phase postoperatively which include pain and numbness in the groin and anterior thigh and weakness of the psoas on the side of approach. The use of iliac crest bone graft is of limited value, especially in the osteoporotic patient. Osteoconductive bone substitutes and allograft material also demonstrate unreliable fusion rates with frequent secondary loss of correction. We have found that BMPII works best in these cases for stand-alone interventions, although it must be clear that evidence for its efficacy in this application has not been shown and a myriad of complications are reported in connection with its use in this setting [42]. The distribution of levels and the 1-year clinical outcome are presented in Fig. 26.3.

Posterior deformity correction is associated with a significant potential for complications such as adjacent-level degeneration or vertebral fractures. There is no consensus on how the degree and extent of the instrumentation may affect the risk of junctional failure. Many factors are related to junctional failure. Sagittal balance is not the only critical parameter; sarcopenia plays an important role. Furthermore neurodegenerative disorders, such as Parkinson’s disease, have a significant impact [43]. Failure usually occurs during the early postoperative period. It typically involves the adjacent segments, as demonstrated by instability when comparing the standing postoperative X-ray with a CT or an MRI in the supine position. Extension of the construct is often needed, and in the presence of a junctional fracture, the use of cemented screw fixation and protective percutaneous cement augmentation may be required [4, 5]. The use of a “discoplasty procedure” can provide anterior column support and thereby avoid an additional anterior procedure (Fig. 26.4).

In cases of segmental instability with a collapsed disk space, the disk height restoration can occur just by positioning the patient on the operating table. The same is true for certain fractures with a kyphotic deformity. Interbody spacers (TLIF, PLIF cages) that work effectively in a healthy bone show a very limited supporting surface and are therefore associated with a significant risk of subsidence in the osteoporotic spine [44]. In addition, the surgical procedure must be expanded considerably for disk removal and cage placement. Therefore, the use of a transdiscal cement injection either in an open fashion through the spinal canal or percutaneously via the foramen through Kambin’s triangle can provide optimal anterior column support. Discoplasty provides a custom-made spacer with a maximal supporting surface. The technique is effective in cases in which the disk space is empty and collapsed but the segment remains mobile. The annulus must be intact and there exists no need to evacuate the disk space. A filling cannula for vertebroplasty is placed into the disk space and high viscous cement is injected into the disk – the annulus provides a containment that prevents the cement from leaking. The procedure is performed under fluoroscopic control. Additional stabilization and fusion of the motion segment(s) are mandatory (Fig. 26.5).

The increasing number of elderly people represents a huge socioeconomic burden in general and is specifically challenging for the medical field [45]. For the spine surgeon, the osteoporotic spine represents the most challenging problem [1, 2]. There are certainly well-established treatment modalities for many spine disorders (stenosis, deformity, instability) – but in combination with osteoporosis, common techniques may fail (i.e., a decompression may provoke a secondary vertebral fracture, a vertebral fracture can turn a silent spinal stenosis into an acute sciatica or paresis that need emergent surgery, a segmental stability may promote an adjacent vertebral fracture, and so on) [4, 5]. So far the most efficient means to overcome the mechanical limitations related with the osteoporotic spine is the use of bone cement [29, 46]. PMMA can enhance the anchoring of pedicle screws, and it can protect adjacent vertebrae from a fracture [34]. The use of PMMA is related with specific risks (cement leakage/embolism, fat embolism) that have to be weighed against the possible benefits [25]. Besides the mechanical problems related with the osteoporotic spine, one must consider the general health state of a patient and carefully balance the risks and benefits of a specific treatment individually for each patient [37].