Superior Sulcus Tumors Invading the Spine: Multimodal Treatment Outcomes From the Preimmunotherapy Era.

Introduction: Curative-intent treatment of superior sulcus tumors (SSTs) of the lung invading the spine presents considerable challenges. We retrospectively studied outcomes in a single center, uniformly staged patient cohort treated with induction concurrent chemoradiotherapy followed by surgical resection (trimodality therapy). Methods: An institutional surgical database from the period between 2002 and 2021 was accessed to identify SSTs in which the resection included removal of at least part of the vertebral body. All patients were staged using fluorodeoxyglucose positron emission tomography (/computed tomography), computed tomography scan of the chest/upper abdomen, and brain imaging. Surgical morbidity was assessed using the Clavien-Dindo classification. Overall and disease-free survival were calculated using the Kaplan-Meier method. Results: A total of 18 patients were included: 8 complete and 10 partial vertebrectomies were performed, with six of the eight complete vertebrectomies involving two vertebral levels, resulting in Complete surgical resection (R0) in 94%. Nine patients had a 1-day procedure, and nine were staged over 2 days. The median follow-up was 30 months (interquartile range 11-57). The 90-day postoperative morbidity was 44% (grade III/IV), with no 90-day surgery-related mortality. There were 83% who had a major pathologic response, associated with improved survival (p = 0.044). The 5-year overall and disease-free survival were 55% and 40%, respectively. Disease progression occurred in 10 patients, comprising locoregional recurrences in two and distant metastases in eight patients. Conclusions: Multimodality treatment in selected patients with a superior sulcus tumor invading the spine is safe and results in good survival. Such patients should be referred to expert centers. Future research should focus on improving distant control (e.g. [neo]adjuvant immunotherapy).

Torsion biomechanics of the spine following lumbar laminectomy: a human cadaver study.

PURPOSE: Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD). METHODS: Ten human cadaveric lumbar spines were obtained (age 75.5, range 59-88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (

Which factors prognosticate spinal instability following lumbar laminectomy?

PURPOSE: Reduced strength and shear stiffness (SS) of lumbar motion segments following laminectomy may lead to instability. The purpose of the present study was to assess a broad range of parameters as potential predictors of shear biomechanical properties of the lumbar spine. METHODS: Radiographs and MRI of all lumbar spines were obtained to classify geometry and degeneration of the motion segments. Additionally, dual X-ray absorptiometry (DXA) scans were performed to measure bone mineral content and density (BMC and BMD). Facet sparing lumbar laminectomy was performed either on L2 or L4, in 10 human cadaveric lumbar spines (mean age 72.1 years, range 53-89 years). Spinal motion segments were dissected (L2-L3 and L4-L5) and tested in shear, under simultaneously loading with 1600 N axial compression. Shear stiffness, shear yield force (SYF) and shear force to failure (SFF) were determined and statistical correlations with all parameters were established. RESULTS: Following laminectomy, SS, SYF, and SFF declined (by respectively 24, 41, and 44%). For segments with laminectomy, SS was significantly correlated with intervertebral disc degeneration and facet joint degeneration (Pfirrmann: r = 0.64; Griffith: r = 0.70; Lane: r = 0.73 and Pathria: r = 0.64), SYF was correlated with intervertebral disc geometry (r = 0.66 for length; r = 0.66 for surface and r = 0.68 for volume), BMC (r = 0.65) and frontal area (r = 0.75), and SFF was correlated with disc length (r = 0.73) and BMC (r = 0.81). For untreated segments, SS was significantly correlated with facet joint tropism (r = 0.71), SYF was correlated with pedicle geometry (r = 0.83), and SFF was correlated with BMC (r = 0.85), BMD (r = 0.75) and frontal area (r = 0.75). SS, SYF and SFF could be predicted for segments with laminectomy (r (2) values respectively: 0.53, 0.81 and 0.77) and without laminectomy (r (2) value respectively: 0.50, 0.83 and 0.83). CONCLUSIONS: Significant loss of strength and SS are predicted by BMC, BMD, intervertebral disc geometry and degenerative parameters, suggesting that low BMC or BMD, small intervertebral discs and absence of osteophytes could predict the possible development of post-operative instability following lumbar laminectomy.

Pelvic reconstruction with a free vascularized distal femur for revision total hip arthroplasty.

The reconstruction of massive structural acetabular defects after revision arthroplasty presents a unique challenge to the orthopedic surgeon. This report describes such a salvage procedure where an autologous vascularized distal femur was used to reconstruct acetabular bone stock with subsequent implantation of a total femoral endoprosthetic replacement that uses a constrained cup and a hinged total knee system. At 2 years of follow-up, there is a good functional result with full incorporation of the graft.

The impact of bone mineral density and disc degeneration on shear strength and stiffness of the lumbar spine following laminectomy.

PURPOSE: Laminectomy is a standard surgical procedure for elderly patients with symptomatic degenerative lumbar stenosis. The procedure aims at decompression of the affected nerves, but it also causes a reduction of spinal shear strength and shear stiffness. The magnitude of this reduction and the influence of bone mineral density (BMD) and disc degeneration are unknown. We studied the influence of laminectomy, BMD, and disc degeneration on shear force to failure (SFF) and shear stiffness (SS). METHODS: Ten human cadaveric lumbar spines were obtained (mean age 72.1 years, range 53-89 years). Laminectomy was performed either on L2 or L4, equally divided within the group of ten spines. BMD was assessed by dual X-ray absorptiometry (DXA). Low BMD was defined as a BMD value below the median. Intervertebral discs were assessed for degeneration by MRI (Pfirrmann) and scaled in mild and severe degeneration groups. Motion segments L2-L3 and L4-L5 were isolated from each spine. SFF and SS were measured, while loading simultaneously with 1,600 N axial compression. RESULTS: Low BMD had a significant negative effect on SFF. In addition, a significant interaction between low BMD and laminectomy was found. In the high BMD group, SFF was 2,482 N (range 1,678-3,284) and decreased to 1,371 N (range 940-1,886) after laminectomy. In the low BMD group, SFF was 1,339 N (range 909-1,628) and decreased to 761 N (range 561-1,221). Disc degeneration did not affect SFF, nor did it interact with laminectomy. Neither low BMD nor the interaction of low BMD and laminectomy did affect SS. Degeneration and its interaction with laminectomy did not significantly affect SS. CONCLUSIONS: In conclusion, low BMD significantly decreased SFF before and after lumbar laminectomy. Therefore, DXA assessment may be an important asset to preoperative screening. Lumbar disc degeneration did not affect shear properties of lumbar segments before or after laminectomy.

Design and management of an orthopaedic bone bank in The Netherlands.

The design and management of an orthopaedic bone bank is a complex process in which medical organisation and legislation intertwine. Neither in the Netherlands, nor in any other European country, there are official guidelines for the organisation and management of an orthopaedic bone bank. In the Netherlands, the recently modified 'law of security and quality for using human materials' (WVKL) dictates requirements for technical and organisational aspects for the use of human tissue and cells. The bone bank procedures include a thorough questionnaire for donor selection, extensive serological, bacteriological and histopathological examination, as well as standard procedures for registration, processing, preservation, storage and distribution of bone allografts. This article describes the organisation of an accredited bone bank and can be used as a proposition for an official guideline or can be useful as an example for other orthopaedic bone banks in Europe.

Abiotrophia defectiva infection of a total hip arthroplasty diagnosed by 16S rRNA gene sequencing.

We describe a case of a total hip arthroplasty infection caused by Abiotrophia defectiva, identified by 16S rRNA gene sequencing. Removal of the prosthesis followed by antibiotic treatment resulted in a good clinical outcome. 16S rRNA gene sequencing can be a useful tool in diagnosing infection with this fastidious microorganism that can easily be misidentified using phenotypic identification methods.

Posterior lumbar interbody fusion using non resorbable poly-ether-ether-ketone versus resorbable poly-L-lactide-co-D,L-lactide fusion devices. Clinical outcome at a minimum of 2-year follow-up.

Previous papers on resorbable poly-L-lactide-co-D,L-lactide (PLDLLA) cages in spinal fusion have failed to report adequately on patient-centred clinical outcome measures. Also comparison of PLDLLA cage with a traditionally applicable counterpart has not been previously reported. This is the first randomized prospective study that assesses clinical outcome of PLDLLA cage compared with a poly-ether-ether-ketone (PEEK) implant. Twenty-six patients were randomly assigned to undergo instrumented posterior lumbar interbody fusion (PLIF) whereby either a PEEK cage or a PLDLLA cage was implanted. Clinical outcome based on visual analogue scale scores for leg pain and back pain, as well as Oswestry Disability Index (ODI) and SF-36 questionnaires were documented and analysed. When compared with preoperative values, all clinical parameters have significantly improved in the PEEK group at 2 years after surgery with the exception of SF-36 general health, SF-36 mental health and SF-36 role emotional scores. No clinical parameter showed significant improvement at 2 years after surgery compared with preoperative values in the PLDLLA patient group. Only six patients (50%) in the PLDLLA group showed improvement in the VAS scores for leg and back pain as well as the ODI, as opposed to 10 patients (71%) in the PEEK group. One-third of the patients in the PLDLLA group actually reported worsening of their pain scores and ODI. Three cases of mild to moderate osteolysis were seen in the PLDLLA group. Following up on our preliminary report, these 2-year results confirm the superiority of the PEEK implant to the resorbable PLDLLA implant in aiding spinal fusion and alleviating symptoms following PLIF in patients with degenerative spondylolisthesis associated with either canal stenosis or foramen stenosis or both and emanating from a single lumbar segment.

Scaffold stiffness influences cell behavior: opportunities for skeletal tissue engineering.

Skeletal defects resulting from trauma, tumors, or abnormal development frequently require surgical treatment to restore normal tissue function. To overcome the limitations associated with conventional surgical treatments, several tissue engineering approaches have been developed. In particular, the use of scaffolds enriched with stem cells appears to be a very promising strategy. A crucial issue in this approach is how to control stem cell behavior. In this respect, the effects of growth factors, scaffold surface characteristics, and external 'active' loading conditions on stem cell behavior have been investigated. Recently, it has become clear that the stiffness of a scaffold is a highly potent regulator of stem cell differentiation. In addition, the stiffness of a scaffold affects cell migration, which is important for the infiltration of host tissue cells. This review summarizes current knowledge on the role of the scaffold stiffness in the regulation of cell behavior. Furthermore, we discuss how this knowledge can be incorporated in scaffold design which may provide new opportunities in the context of orthopedic tissue engineering.

Long-term follow-up of 15 patients with non-metastatic Ewing's sarcoma and a skip lesion.

UNLABELLED: BACKGROUND Skip lesions in Ewing's sarcoma of the bone seem to be rare; to our knowledge only 7 cases have been published in the English medical literature. METHODS: We retrospectively reviewed imaging and histological data relating to 235 patients with non-metastatic Ewing's sarcoma of the bone who participated in the cooperative Ewing's sarcoma study (CESS 86 and CESS 91), and we identified 15 patients with a skip lesion at diagnosis. RESULTS: The skip lesion was located in the same bone as the primary tumor in 13 patients, and in an adjacent juxtaarticular bone in 2 cases. The average follow-up was 11 years. Despite aggressive treatment including surgery in all cases, tumor relapse occurred in 9 patients, and 7 of these patients died due to metastatic disease. INTERPRETATION: Skip lesions in patients with otherwise non-metastatic skeletal Ewing's sarcoma may be of the same consequence as the molecular detection of marrow metastases and possibly confer a worse prognosis. Newer imaging modalities (for example PET) and careful staging work-up may indicate that skip metastases in Ewing's sarcoma are more common than previously suspected.