Are enlarged peroneal tubercle and accessory anterolateral talar facet associated with calcaneal spur?

BACKGROUND

As the anatomical variations of the foot, enlarged peroneal tubercle (EPT) and accessory anterolateral talar facet (AALTF) have attracted the attention of foot surgeons in recent years. However, EPT and AALTF have not been examined for a relationship with calcaneus spur (CS) as a common osteophyte.

METHODS

The subjects were 369 individuals who died in northeastern Thailand and were preserved as skeletal specimens. The authors examined for the presence of left and right EPT, AALTF, and calcaneus spur (CS). We divided the EPT (+) group with EPT and the EPT (-) group without it and also divided the AALTF (+) group with AALTF and the AALTF (-) group without it. The age at death and the presence of CS were compared statistically between the EPT (+) and EPT (-) groups and between the AATLF (+) and AALTF (-) groups.

RESULTS

Out of the total 369 cases, EPT was found in 117 cases (31.7%), AALTF was positive in 91 cases (24.7%), and CS was found in 194 cases (52.3%). In comparison between EPT (+) and EPT (-) groups, CS was significantly higher (p < 0.0001) in the EPT (+) group, but there was no significant difference in age at death. In comparison between AALTF (+) and AALTF (-) groups, there was no significant difference in age at death or CS.

CONCLUSION

This study showed a strong relationship between EPT and CS, and the prevalence of EPT and AALTF by age in Thailand was first reported. We believe it helps to know the pathogenesis and biomechanism of EPT and AALTF.

TRIAL REGISTRATION

Not applicable.

Clinical and oncologic outcomes of posterior only total en bloc spondylectomy for spinal metastasis involving third lumbar vertebra: A case series

INTRODUCTION

A posterior-only total en bloc spondylectomy (TES) of the L3 level was deemed a highly intricate surgical procedure, necessitating the preservation of the L3 nerve root to prevent neurological deterioration. Despite bilateral preservation efforts of the L3 nerve roots, neurological deterioration proved unavoidable. This study aims to present the clinical, neurologic, and oncologic outcomes of spinal metastasis patients who underwent a posterior-only approach TES, encompassing the L3 vertebra.

MATERIALS AND METHODS

All patients with L3-involved spinal metastasis undergoing posterior TES between January 2018 and January 2022 were investigated. The primary outcomes considered were the local recurrence rate and manual muscle testing of the lumbar myotome. Secondary outcomes included Frankel neurological status, operative time, blood loss, perioperative and postoperative complications, and Eastern Cooperative Oncology Group score.

RESULTS

Five patients with TES involving L3 (three females) met the inclusion criteria. All patients had solitary metastases (three in the lungs, 2 in the breasts). Postoperatively, all patients experienced weakness of the hip flexors, but they were able to ambulate independently 12 months after surgery. One patient exhibited adjacent segment (L2) disease progression and underwent corpectomy 18 months after TES. No local recurrences at the surgical site were detected on magnetic resonance imaging at the 1-year follow-up.

CONCLUSION

Posterior-only TES for L3-involved vertebrae yielded excellent results in the local control of metastatic disease. Despite hip flexor weakness, all patients were able to regain independent ambulation after 12 months. TES can offer favorable clinical and oncological outcomes in patients with solitary spinal metastases.

Experimental Study of Failures of the Rigid Spinal Posterior Fixation System Under Compressive Load Conditions: A Cadaver Study

Background Many studies have been conducted on the biomechanics of the spine to elucidate the fixation properties of spinal fusion surgery and the causes of instrumentation failure. Among these studies, there are some studies on load sharing in the spine and measurement using strain gauges and pressure gauges, but there is a lack of research on axial compressive loads. Methods Axial compressive load tests were performed on human cadaveric injured lumbar vertebrae fixed with pedicle screws (PS). Both the strain generated in the PS rod and the intradiscal pressure were measured. Subsequently, the stress generated in the PS rod and the load sharing of the spine and instrumentation were calculated. Results Even when only compressive load is applied, bending stress of more than 10 times the compression stress was generated in the rod, and the stress tended to concentrate on one rod. Rod deformation becomes kyphotic, in contrast to the lordotic deformation behavior of the lumbar spine. The stress shielding rate was approximately 40%, less than half. Conclusions This study obtained basic data useful for constructing and verifying numerical simulations that are effective for predicting and elucidating the causes of dislodgement and failure of spinal implants.

Validation of a Diagnostic Model to Differentiate Multiple Myeloma from Bone Metastasis

Purpose

A diagnostic model to differentiate multiple myeloma (MM) from bone metastasis (BM) in patients with destructive bone lesions (MM-BM DDx) was developed to promote timely and appropriate referral of patients with MM to hematologists. External validation has never been conducted. This study aims to externally validate the performance of the MM-BM DDx model.

Patients and Methods

This multi-center external validation study was conducted using retrospective data of patients over 45 years old diagnosed with MM or BM at six university-affiliated hospitals in Thailand from 2016 to 2022. The MM-BM DDx development dataset, including patients from 2012 to 2015, was utilized during external validation. Diagnostic indicators for MM included in the MM-BM DDx model are serum creatinine, serum globulin, and serum alkaline phosphatase (ALP). MM and BM diagnosis was based on the documented International Classification of Diseases 10th Revision codes. Model performance was evaluated in terms of discrimination, calibration, and accuracy.

Results

A total of 3018 patients were included in the validation dataset (586 with MM and 2432 with BM). Clinical characteristics were similar between the validation and development datasets. The MM-BM DDx model's predictions showed an AUC of 0.89 (95% CI, 0.87, 0.90). The predicted probabilities of MM from the model increased concordantly with the observed proportion of MM within the validation dataset. The estimated sensitivity, specificity, and LR for each odds class in the validation dataset were similar to those of the development dataset.

Conclusion

The discriminative ability and calibration of the MM-BM DDx model were found to be preserved during external validation. These findings provide support for the practical use of the MM-BM DDx model to assist clinicians in identifying patients with destructive bone lesions who are likely to have MM and enable them to arrange timely referrals for further evaluation by hematologists.

Effect of bone cement augmentation with different configurations of the dual locking plate for femoral allograft fixation: finite element analysis and biomechanical study

AIMS

Implant failure in allograft reconstruction is one of the most common problems after treating a large bone defect for a primary bone tumor. The study aimed to investigate the effect of bone cement augmentation with different configurations of dual locking plates used for femoral allograft fixation.

METHODS

Four finite element (FE) models of the femur with a 1-mm bone gap were developed at the midshaft with different configurations of the 10-hole fixation dual locking plate (LP) with and without intramedullary bone cement augmentation. Model 1 was the dual LP at the lateral and medial aspect of the femur. Model 2 was Model 1 with bone cement augmentation. Model 3 was the dual LP at the anterior and lateral aspect of the femur. Finally, Model 4 was Model 3 with bone cement augmentation. All models were tested for stiffness under axial compression as well as torsional, lateral-medial, and anterior-posterior bending. In addition, the FE analyses were validated using biomechanical testing on a cadaveric femur.

RESULTS

Model 2 had the greatest axial compression stiffness, followed by Models 1, 4, and 3. Bone cement augmentation in Models 2 and 4 had 3.5% and 2.4% greater axial stiffness than the non-augmentation Models 1 and 3, respectively. In the bone cement augmentation models, Model 2 had 11.9% greater axial compression stiffness than Model 4.

CONCLUSION

The effect of bone cement augmentation increases construct stiffness less than the effect of the dual LP configuration. A dual lateral-medial LP with bone cement augmentation provides the strongest fixation of the femur in terms of axial compression and lateral bending stiffness.

Clinical results of total en bloc spondylectomy using a single posterior approach in spinal metastasis patients: Experiences from Thailand

AIM

To demonstrate a single posterior approach, total en bloc spondylectomy (TES) could be performed safely without preoperative embolization in spinal metastasis patients.

MATERIALS AND METHODS

Thirteen solitary spinal metastasis patients (five males) underwent single posterior approach TES at the thoracolumbar spine without preoperative embolization from January 2018 to January 2020. The primary sites were the breast (n = 4), hepatocellular carcinoma (n = 2), colon (n = 2), and others (n = 5). All patients underwent single posterior TES. The Eastern Cooperative Oncology Group, Frankel neurological status, operative time and blood loss, and any complications were all recorded. The patients were regularly followed-up with radiography, computed tomography, and magnetic resonance imaging to detect any local recurrences.

RESULTS

The mean operative time was 354.6 min, and the mean operative blood loss was 2134.62 ml. None of the patients experienced any perioperative complications. Within the follow-up period (3-24 months), no local recurrences were detected. Two patients (15.38%) were found to have distant metastasis to adjacent and remote vertebrae. Three patients were lost to follow-up, and three patients died of disease. Six patients showed an improved ECOG functional status by at least one grade. Four of Frankel A patients improved their neurological status by at least one grade.

CONCLUSION

Even without embolization, single posterior TES at the thoracolumbar spine is safe and effective for short-term local control in solitary spinal metastasis. However, TES cannot prevent distant metastasis. Longer-term follow-up studies will be able to further identify the benefits of TES for the long-term local control of diseases.

Biomechanics comparison between endobutton fixation and syndesmotic screw fixation for syndesmotic injury ankle fracture; a finite element analysis and cadaveric validation study

Introduction

Various syndesmotic fixation methods in ankle injury are recommended; however, a lack of biomechanical information persists regarding the stiffness of the fixation methods. The current study thus aimed to assess biomechanical cadaveric validation and perform a finite element analysis of syndesmotic fixation comparing endobutton vs. screw after syndesmotic injury with an ankle fracture.

Method

Five pairs of ankles of fresh cadavers were used for the validity test for Anterior Inferior Tibiofibular Ligament (AITFL), Posterior Inferior Tibiofibular Ligament (PITFL), and Interosseous ligament biomechanics properties. Four finite element models (FEM) were created: an intact model, a fracture model with/without syndesmotic injury, an endobutton fixation model, and a syndesmotic screw fixation model. Each FEM was tested vis-à-vis external rotation force, anteroposterior translation force, and compression force until model failure. The primary outcomes were stiffness and force until failure.

Result

The respective anteroposterior translation force for the stiffness of the intact model, the screw fixation model, and the endobutton fixation was 8.14, 9.15, and 8.17 N/mm. The respective external rotation force for the stiffness of intact, screw fixation, and endobutton model was 0.927,0.949, and 0.940 Nm/degree. The respective stress under compression force in the intact, screw fixation, and endobutton model was 39.94,25.59, and 37.30 MPa.

Conclusion

Both screw and endobutton fixation models provided more translation, compression, and rotation stability than normal syndesmosis, but the screw model provided greater translation and compression force stability than the endobutton model. There was no difference in rotational stability between the two models. We thus recommend the same rehabilitation protocol for both fixation methods; however, vigorous translation and compression should be avoided when using endobutton fixation.

Allograft versus autograft for reconstruction after resection of primary bone tumors: a comparative study of long-term clinical outcomes and risk factors for failure of reconstruction

There have been no studies comparing the outcomes of nonvascularized autograft (NA) and allograft after resection of primary bone tumors. This study compares the clinical, functional outcomes of NA and allograft reconstruction and analyzes the risk factors for failure after these procedures. A retrospective study of patients with primary bone tumors of the extremities who underwent NA (n = 50) and allograft reconstruction (n = 47). The minimum follow up time was 24 months. The mean time to union for the NA and allograft group was 9.8 ± 2.9 months and 11.5 ± 2.8 months, respectively (p = 0.002). Reconstruction failure in the NA and allograft group was 19 (38%) and 26 (55.3%), respectively. Nonunion (30%) was the most common complication found in the NA group, while structural failure (29.8%) was the most common in the allograft group. There was no significant difference in functional outcome in terms of the mean Musculoskeletal Tumor Society score between the NA and allograft groups (23.5 ± 2.8 and 23.9 ± 2.1, respectively, p = 0.42). Age, sex, tumor location, graft length, method of reconstruction did not significantly influence failure of reconstruction. Chemotherapy was the only significant risk factor affecting outcomes (HR = 3.49, 95% CI = 1.59–7.63, p = 0.002). In the subgroup analysis, the use of chemotherapy affected graft-host nonunion (p < 0.001) and structural failure in both the NA and allograft groups (p = 0.02). Both NA and allograft reconstruction methods provide acceptable clinical and functional outcomes. Chemotherapy is a risk factor for failure of both reconstructions, particularly graft-host nonunion and structural failure.

Descriptive epidemiology of soft tissue sarcomas and gastrointestinal stromal tumors in Thailand

This study aimed to analyze burden of STS and GIST in population and survival rate which represented the current situation of treatment in Thailand. The data was collected from five population-based cancer registries around the country for the period 2001 through 2015. The Segi world standard population was used to calculated age-standardized incidence rates (ASR). Standardized rate ratios (SRR) were used to compare populations. Joinpoint Trend Analysis was used to assess changes in incidence. STATA was used to examine patient survival rates. During the study period, 4080 cases of STS and 457 cases of GIST were reported. The ASR of STS and GIST was 2.14/100,000 person-years and 0.22/100,000 person-years, respectively. The most common histological types of STS were unspecified sarcoma (24.8%), leiomyosarcoma (19.0%) and liposarcoma (11.4%). The overall ASR of STS in Thailand was relatively low compared to Western countries. The five-year survival rate was 62.6% for STS and 63.4% for GIST, which was comparable to the rates reported in other countries. This is the first report of STS and GIST from PBCRs in Thailand. Based on current healthcare service, an overall survival rates of STS and GIST are comparable to those reported from others.

Current status and problems of orthopaedic residents in Thailand and Myanmar

Background: There is no research about current experiences of orthopaedic residents in Thailand and Myanmar.

Methods: A questionnaire survey was distributed among Thai and Myanmar orthopaedic residents to assess their current experiences. This study included a total of 168 participants, comprising 92 orthopaedic residents in Thailand, and 76 in Myanmar who answered the questionnaire. The survey comprised nine questions about issues such as the contents of residency training programs, current training satisfaction, and future careers. The survey was administered anonymously between October 2020 and January 2021.

Results: Regarding training content, 24 residents (14.3%) reported being "very satisfied", 103  (61.3%) were "satisfied", 37 (22.0%) were "moderately satisfied", and four (2.4%) were "dissatisfied", and respondents spent a mean of 3.1 h/day reading textbooks and research papers. As for salary, five (3.0%) residents answered "satisfied", 46 (27.4%) responded "moderately satisfied", and 117 (69.6%) were "dissatisfied".

Conclusions: Many orthopedic residents in Thailand and Myanmar were enthusiastic about and satisfied with their training. Their only problem was that the salary was low.

Incidence and Skeletal Features of Developmental Cervical and Lumbar Spinal Stenosis

STUDY DESIGN

Cross-sectional study.

PURPOSE

To report the prevalence and relationship of developmental cervical and lumbar spinal stenosis (DCSS and DLSS) with the bone parameters of the skull and extremities.

OVERVIEW OF LITERATURE

DCSS and DLSS are found occasionally in daily practice. DCSS and DLSS can cause compressive myelopathy, radiculopathy, and cauda equina syndrome; however, data on their prevalence and correlation with skull and skeletal extremity profiles is scarce.

METHODS

A cross-sectional measurement study of 293 whole-body dried-bone samples was conducted. We measured the anteroposterior (AP) and transverse diameter of the fourth to sixth cervical vertebrae (C4-C6) and third to fifth lumbar vertebrae (L3-L5). Stenosis of the cervical spine and lumbar spine was defined as an AP diameter of <12 mm and <13 mm, respectively. We also measured the skull circumference, the AP and transverse diameters of the foramen magnum, the inner and outer inter distances between the left and right orbital bones, the humerus length, and the femoral length. Kruskal-Wallis and post hoc analyses were used in the statistical analyses.

RESULTS

The age was 22-93 years. DCSS was found in 59 (20.1%) and DLSS in 28 (9.6%). Twelve samples had both DCSS and DLSS (development spinal stenosis, DSS). When compared to the "no spinal stenosis sample," DSS (-), DCSS and DSS had a significantly smaller skull circumference, the transverse diameter of the foramen magnum, and inner and outer distance between the orbital bone (p<0.05). There was no significant difference in humeral length, femoral length, or AP diameter of the foramen magnum.

CONCLUSIONS

DCSS was correlated with a small skull, a small transverse diameter of the foramen magnum, and a small orbital bone. A small skull was strongly associated with a small cervical canal. DLSS, on the other hand, was unrelated to either a small cervical canal or a small skull.

Current status and problems of orthopaedic residents in Thailand and Myanmar

Background: There is no research about current experiences of orthopaedic residents in Thailand and Myanmar. Methods: A questionnaire survey was distributed among Thai and Myanmar orthopaedic residents to assess their current experiences. This study included a total of 168 participants, comprising 92 (94.8%) of 97 orthopaedic residents in Thailand, and 76 (97.4%) of 78 in Myanmar who answered the questionnaire. The survey comprised nine questions about issues such as the contents of residency training programs, current training satisfaction, and future careers. The survey was administered anonymously between October 2020 and January 2021. Results: Regarding training content, 24 residents reported being "very satisfied", 103 were "satisfied", 37 were "moderately satisfied", and four were "dissatisfied", and respondents spent a mean of 3.1 h/day reading textbooks and research papers. As for salary, five residents answered "satisfied", 46 responded "moderately satisfied", and 117 were "dissatisfied". Conclusions: Many orthopedic residents in Thailand and Myanmar were enthusiastic about and satisfied with their training. Their only problem was that the salary was low.

Safety and Neurologic Recovery of L2 Nerve Root Sacrificed in Total En Bloc Spondylectomy Involving the L2 Vertebra

BACKGROUND

The L2 nerve root is considered part of the lumbar plexus that innervates the iliopsoas (IP) and quadricep muscles (Qd). Total en bloc spondylectomy (TES) at the L2 vertebra requires bilateral nerve root transection to facilitate surgical dissection and vertebral body removal. Information regarding neurological function recovery of the IP and Qd in patients with muscle weakness before TES is lacking. We aimed to report the neurological recovery of IP and Qd after TES involving the L2 vertebra in preoperative lower extremity weakness in spinal tumor patients.

METHODS

We prospectively recorded all L2-involved spinal tumor patients undergoing TES between January 2018 and November 2020. As a primary outcome, we recorded the Manual Muscle Testing (MMT) grade of the IP and Qd preoperatively, immediately postoperatively, and at follow-up. Secondary outcomes included the Frankel neurological status, sensation impairment, and the Eastern Cooperative Oncology Group score.

RESULTS

From 8 TES-involving L2 patients, 6 (4 males) met the inclusion criteria. One patient had first-grade deterioration of the Qd MMT immediately postoperatively. All patients could ambulate independently 6 months after surgery. Five patients required follow-up for more than 1 year and could walk without any gait aids. All patients had persistent anterior groin and bilateral thigh numbness until the final follow-up.

CONCLUSION

Neurological recovery of the IP and Qd muscles as measured by MMT can occur within 6 months of bilateral L2 nerve root transection. Bilateral L2 nerve root sacrifice can have acceptable neurological outcomes and recovery, even in patients with preoperative IP and Qd weakness.

LEVEL OF EVIDENCE

4.

An analysis of the incidence and survival rates of bone sarcoma patients in thailand: reports from population-based cancer registries 2001-2015

BACKGROUND

Epidemiology data from population-based cancer registries (PBCR) can be very valuable in the development of health policy and for improving the quality of cancer control strategies.

METHODS

This study analyzed the incidence of bone sarcomas in Thailand during 2001 - 2015 by analyzing data obtained from 5 PBCRs across country. Incidence rates per million person-years by sex, histological subtype, primary site and 5-year age group were calculated. Age-standardized incidence rates (ASR) were adjusted using the WHO's World Standard Population and comparisons between populations were done using standardized rate ratios (SRR). Incidence trends were evaluated using Joinpoint Trend Analysis. Survival rates were analyzed using STATA.

RESULTS

The ASR of bone sarcomas in Thailand was 5.1/10⁶ person-years, with an estimated 328 newly diagnosed bone sarcomas per year for the country overall. Osteosarcoma (52.5%), chondrosarcoma (18%), Ewing's sarcoma (11.6%), giant cell tumor (4.8%) and chordoma (4.7%) were the most common malignant bone tumors, representing 91.5% of all bone sarcomas. Bone sarcoma has a predilection for males (1.29:1) and an age-specific bimodal rate pattern closely related to the major histological subtypes, osteosarcoma. One- and five-year survival rates of Thai patients with bone sarcoma were 74% and 52%, respectively. Survival rates of bone sarcomas, particularly osteosarcoma, were lower than the rates reported from the United States, Europe and Japan.

CONCLUSION

The lower overall survival rate of bone sarcoma represented the gap of bone sarcoma control program in Thailand. That indicates the need for improvement in health promotion, treatment process and chemotherapy for bone sarcoma patients in the future.

Total en bloc spondylectomy is worth doing in complete paralysis spinal giant cell tumor, a minimum 1-year follow-up

OBJECTIVE

To investigate the neurological recovery of Frankel A spinal giant cell tumor (GCT) patients after they had received a Total En Bloc Spondylectomy (TES).

MATERIALS AND METHODS

We retrospectively recorded data of three patients (two females) with mobile spine GCT (T6, T10, and L2) Enneking stage III with complete paralysis before surgery, who had undergone TES in our institute from January 2018 to September 2020. The duration of neurologic recovery to Frankel E was the primary outcome. The intra-operative blood loss, operative time, operative-related complications, and the local recurrence were the secondary outcomes.

RESULTS

The duration of suffering from Frankel A to TES surgery was 2 months for the T6 patient, 3 weeks for the T10 patient, and 1 month for the L2 patient. Three patients had achieved full neurological recovery to Frankel E within 6 months after TES (T6 for 5 months, T10 for 3 months, and L2 for 3 months). The average blood loss was 2833.33 ml and the mean operative time was 400 min. Up until the last follow-up (13-25 months), no evidence of local recurrences had been found in any of the three patients.

CONCLUSION

Frankel A spinal GCT patients can achieve full neurological recovery after TES, if the procedure is performed within 3 months after complete paraplegia. TES can effectively control any local recurrences.

Resection arthrodesis and osteoarticular allografts reconstruction after resection of primary bone tumors around the knee: Long-term clinical outcomes and prognostic factors for failure of biological reconstruction

AIM

The biological reconstruction of the knee with osteoarticular allografts and resection arthrodesis have been reported but there has not yet been a direct comparison between both these procedures. This study aimed to identify the prognostic factors that influence failure of biological reconstruction and compared the results between both procedures.

METHODS

Between 1994 and 2017, we performed 92 limb-sparing procedures using resection arthrodesis (n = 53) and osteoarticular allograft reconstruction (n = 39) for the management of primary bone tumors around the knee. The minimum follow-up time was 2 years in both groups.

RESULTS

The failure rate of reconstruction in the osteoarticular allograft and resection arthrodesis group was 48.7% and 39.6%, respectively (p = 0.75). The mean MSTS score in the osteoarticular allograft and resection arthrodesis group was 23.7 and 21.8, respectively (p = 0.01). The significant risk factor for failure after biological reconstruction was the administration of chemotherapy (p = 0.001; HR = 3.39; 95% CI, 1.60-7.17).

CONCLUSION

Patients who underwent osteoarticular allograft had a better functional outcome than those who underwent resection arthrodesis reconstruction, but clinical outcomes between the groups were comparable. Chemotherapy is a significant adverse prognostic factor for failure of biological reconstruction.

The most appropriate titanium mesh cage size for anterior spinal reconstruction after single-level lumbar total en bloc spondylectomy: a finite element analysis and cadaveric validation study

Purpose

There is little information available regarding the cage diameter that can provide the most rigid construct reconstruction after total en bloc spondylectomy (TES). The aim of this study was thus to determine the most appropriate titanium mesh cage diameter for reconstruction after spondylectomy.

Methods

A finite element model of the single level lumbar TES was created. Six models of titanium mesh cage with diameters of 1/3, 1/2, 2/3, 3/4, 4/5 of the caudad adjacent vertebra, and 1/1 of the cephalad vertebra were tested for construct stiffness. The peak von Mises stress (MPa) at the failure point and the site of failure were measured as outcomes. A cadaveric validation study also conducted to validate the finite element model.

Results

For axial loading, the maximum stress points were at the titanium mesh cage, with maximum stress of 44,598 MPa, 23,505 MPa, 23,778 MPa, and 16,598 MPa, 10,172 MPa, 10,805 MPa in the 1/3, 1/2, 2/3, 3/4, 4/5, and 1/1 diameter model, respectively. For torsional load, the maximum stress point in each of the cages was identified at the rod area of the spondylectomy site, with maximum stress of 390.9 MPa (failed at 4459 cycles), 141.35 MPa, 70.098 MPa, and 88.972 MPa, 42.249 MPa, 15.827 MPa, respectively. A cadaveric validation study results were coincided with the finite element model results.

Conclusion

The most appropriate mesh cage diameter for reconstruction is 1/1 the diameter of the lower endplate of the adjacent cephalad vertebra, due to its ability to withstand both axial and torsional stress. According to the difficulty of large size cage insertion, a cage diameter of more than half of the upper endplate of the caudad vertebrae is acceptable in term of withstand stress. A cage diameter of 1/3 is unacceptable for reconstruction after total en bloc spondylectomy.

Optimal configuration of a dual locking plate for femoral allograft or recycled autograft bone fixation: A finite element and biomechanical analysis

BACKGROUND

Allografts and recycled bone autograft are commonly used for biological reconstruction. The dual locking plates fixation method has been advocated for increasing allograft stability and preventing fixation failure; however, the biomechanical properties of the various configurations of dual locking plates have not been extensively studied.

METHODS

In a finite element (FE) analysis, we developed 6 patterns of different dual locking plate configurations for fixation of the mid shaft of the femur. The maximum strains were recorded for each of the 6 models then axial, bending and torsion stiffness were calculated. The FE analysis was validated the results with mechanical testing (axial compression, bending, and torsional stiffness) on a cadaveric femur.

FINDINGS

The highest axial compression (715.41 N/mm) and lateral bending (2981.24 N/mm) was found in Model 4 (with two 10-hole locking plates placed at the medial and lateral side), while the highest torsional stiffness (193.59 N·mm /mm) was found in Model 3 (with 8- and 10-hole locking plates placed at the posterior and lateral side). Excellent agreement was found between the finite element analysis and biomechanical testing (r² = 0.98).

INTERPRETATION

The dual locking plate configuration with medial and lateral, 10-hole locking plates provided the most rigid and strongest fixation of the femur; both in terms of axial compression and lateral bending stiffness.

Pedicle Screw System May Not Control Severe Spinal Rotational Instability

STUDY DESIGN

An in vitro biomechanical study.

OBJECTIVE

The purpose of this study is to discuss whether pedicle screw systems can control spinal rotational instability in a functional spinal unit of lumbar spine on human cadaver.

SUMMARY OF BACKGROUND DATA

Rotational experiments using deer lumbar cadaveric models showed that rotational range of motion (ROM) of the model fixed by a pedicle screw system with crosslinking after total facetectomy for both the sides was larger than that in the intact model, and stated that spinal rotational instability could not be controlled using a pedicle screw system.

METHODS

A rotation experiment using 10 functional spinal units (L3-4) of lumbar spine on human cadavers was performed by preparing the four models (intact model, damaged model, pedicle screw model, and crosslink (CL) model) in stages, then calculating and comparing rotational ROM among the four models.

RESULTS

Rotational ROM in the CL model was still larger than that of the intact model in all the samples. And, rotational ROM decreased in the order of damaged model >> pedicle screw model > CL model > intact model. Statistical analysis revealed significant differences between all models (P < 0.001).

CONCLUSIONS

Pedicle screw systems may not control severe spinal rotational instability in human lumbar cadaveric models with total facetectomy on both the sides. This may represent a major biomechanical drawback to the pedicle screw system.

LEVEL OF EVIDENCE

N/A.

Cholangiocarcinoma with spinal metastasis: Single center survival analysis

The aim of this study was to perform a survival analysis of Cholangiocarcinoma (CCA) with spinal metastases. 55 cases of CCA with spinal metastases were retrospectively reviewed. We recorded age, sex, Kanofsky performance score, Frankel scale, number and region of affected vertebrae, presence of appendicular bone metastases, treatment received, and survival time; then performed a survival analysis. Overall median survival was 4months (95%CI, 2.89-5.11). Frankel A had the poorest survival (2months-95%CI, 1.15-2.85) compared to Frankel C and D (P=0.004 and <0.001, respectively). One-level spinal metastasis had the longest survival (8months-95%CI, 5.98-10.02) compared to two-level and more than two-level involvement (P=0.036 and 0.001, respectively). The higher Kanofsky score had the longer survival (11months-95%CI, 9.61-12.39) compared with the low and moderate score groups (P<0.001 and 0.012, respectively). Radiation therapy had a survival of 6months (95%CI, 3.41-8.59), significantly longer than the 3months for palliative spine surgery and 2months for palliative treatment alone. CCA resection and palliative spine surgery-when performed together and/or combined with other adjuvant treatment(s)-had a survival time of longer than 9months. In conclusion, CCA with spinal metastases had a poor median survival. A single level of affected spine, a Frankel scale of C or better, a moderate to high Kanofsky score, and radiation therapy were associated with significantly longer median survival. CCA resection and spinal surgery may play an important role in prolonging survival when used in conjunction with other adjuvant treatment modalities.

The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ): A validation of the reliability of the Thai version

BACKGROUND

The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was developed by the Japanese Orthopedic Association (JOA) for assessment of lower back pain and lumbar spinal disease. We aimed to translate the JOABPEQ into Thai and test its reliability and validity in the Thai context.

METHODS

The original JOABPEQ was translated into Thai in accordance with international recommendations. Then 180 lumbar spinal disease patients (mean age 58.58 ± 11.97, 68.3% female) were asked to complete the Thai version of the JOABPEQ twice at 2-week intervals. Test-retest reliability was analyzed using the intra-class correlation coefficient (ICC). Internal consistencies were analyzed using Cronbach's alpha, while the construct validity was compared with the Thai version of the modified SF-36, and tested using the Spearman's rank correlation coefficient.

RESULTS

The Thai JOABPEQ showed satisfactory test-retest reliability in all parameters (Intra-class Correlation Coefficient 0.761-0.862). The variables low back pain, walking ability, social life function, and mental health had satisfactory internal consistency (the respective Cronbach's α was 0.798, 0.721, 0.707, and 0.795). Only the lumbar function parameter showed moderate reliability (Cronbach's α = 0.654). All of the variables in the Thai JOABPEQ had a statistically positive correlation with the correspondent Thai SF-36 subscales (Spearman's rank correlation p value < 0.05).

CONCLUSION

The Thai version of JOABPEQ had satisfactory internal consistency, test-retest reliability, and construct validity; it can be used as a reliable tool for assessing quality of life for lumbar spinal disease patients in Thailand.

Validation of the reliability of the Thai version of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ)

BACKGROUND

The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) was developed to resolve problems associated with the original evaluation of cervical myelopathic patients. The aim of this study was to translate the JOACMEQ into Thai as per international recommendations, and to test its reliability and validity in the Thai context

METHODS

The JOACMEQ was translated into Thai, using international guidelines. Cervical myelopathy patients (n = 70; 31 males) were asked to complete the Thai version JOACMEQ twice (4 weeks apart). Test-retest reliability was analyzed using the intra-class correlation coefficient (ICC). Internal consistencies were analyzed using Cronbach's alpha, while the construct validity was compared with the Thai version modified SF-36; using the Spearman's rank correlation coefficient.

RESULTS

The Thai JOACMEQ produced good reliability (i.e., the ICC was >0.9 in 2 parameters and >0.8 in one). Overall the Cronbach's α for the 24 questions showed very high internal consistency (Cronbach's α > 0.8) and almost all Cronbach's α showed satisfactory internal consistency except for bladder function. The Spearman's rank correlation for all the JOACMEQ parameters had a positive correlation with all Thai SF 36 subscales, especially the quality of life parameter, which showed a strong correlation with all SF-36 subscales.

CONCLUSION

The Thai version of the JOACMEQ had satisfactory internal consistency and test-retest reliability: it also had good construct validity. It can therefore be used as a reliable tool for assessing quality of life for cervical myelopathy patients in Thailand.

Fatal peripheral T-cell lymphoma following intramuscular tuberculosis of the forearm

Intramuscular tuberculosis (TB) is a rare disease, and lymphoma may occur following a bout of TB. We report on an unusual presentation of peripheral T-cell lymphoma that occurred after an infiltrative lesion of intramuscular TB of the forearm in an immunocompetent host. To our knowledge, this is the first case where TB of a muscle presenting as an infiltrative lesion instead of an abscess developed into peripheral T-cell lymphoma.

Morphological study of subaxial cervical pedicles by using three-dimensional computed tomography reconstruction image

Malpositioning of cervical screws risks neurovascular injury. A cervical screw fixation system can provide proper rigidity, alignment correction, and high rates of fusion afforded by high pullout biomechanical strength. The objective is to assess the dimensions and axis of the C3–C7 cervical pedicles. A 1-mm slice thickness computed tomography (CT) scan of the cervical spine of 30 patients (15 males, 15 females) were analyzed and reconstructed in three-dimensions using Mimics^® 10.01 software. We measured pedicle axis length (PAL), pedicle and lateral mass length (PL-LM), pedicle length (PL), outer pedicle width (OPW), and pedicle transverse angle (PTA) from the axial image and outer pedicle height (OPH) and pedicle sagittal angle (PSA) from the sagittal image. The OPH and OPW at all subaxial cervical spines were suitable for insertion of 3.5 mm cervical pedicle screws. PSA was directed cranially at C3 to C5 (13.84, 7.09, and 2.71) and directed caudally at C6 and C7 (–4.55, –6.94). PTA was greatest at C5 and smallest at C7. The respective difference between the left and right side for nearly all parameters was not statistically significant (except for C6 PL and C7 OPH). Females had a significantly smaller OPH and OPW than males at nearly all levels. The PTA was not significantly different between the sexes. Cervical pedicle screw fixation in the Thai population can be safely performed and guidelines for insertion at each vertebra documented. Appropriate preoperative planning is necessary to achieve safe and accurate placement of the screws.

Clinical results of primary malignant musculoskeletal tumor treated by wide resection and recycling autograft reconstruction using liquid nitrogen

AIM

To evaluate the clinical results of primary malignant musculoskeletal tumors treated with wide resection and recycling autograft reconstruction using liquid nitrogen.

METHODS

We reviewed 12 patients who had a primary malignant bone and soft tissue tumor treated by wide resection and recycling autograft reconstruction using liquid nitrogen between March 2006 and March 2013. The results were judged by recurrence, functional status and complications. Functional status was assessed according to the Musculoskeletal Tumor Society Score (MSTSS). Clinical failure was defined as need for reoperation in order to change the type of reconstruction or to amputate, and the presence of local recurrence.

RESULTS

The most common tumor was osteosarcoma (eight cases) followed by Ewing's sarcoma (two cases). The tibia was the most frequently involved skeletal site (six cases) followed by the femur (three cases). The median follow-up period was 32 months. In 12 patients, 7 were still alive without recurrence. There were 3 clinical failures: 1 local recurrence and 2 graft complications at 28, 51 and 20 months after reconstruction, respectively. The main complication was infection (three cases). All osteotomy sites were radiographic unions, and the union time was 8.2 ± 2.7 months. The mean ± SD MSTSS score was 79% ± 11%; excellent functional results were achieved in seven patients.

CONCLUSIONS

Recycling autograft reconstruction using liquid nitrogen had favorable clinical outcomes in terms of functional status and local recurrence. This reconstruction method, therefore, represents a reasonable alternative for limb salvage surgery.

Prevalence of known and unknown primary tumor sites in spinal metastasis patients

Study Design:

A retrospective study.

Objectives:

Three objectives have been designated for this study: (1) to determine the prevalence of identifiable and non-identifiable primary tumor sites in patients with spinal metastasis, (2) to identify the most common site of the known primary tumor sites, and (3) to identify the factors associated with survival time.

Summary of Background Data:

The spine is the third most common metastatic site for several primary visceral carcinomas. The primary tumor site could not be identified in 15% to 20% of patients who had been diagnosed of with a skeletal metastasis. Most of the previous studies on skeletal metastasis have not been limited to spinal metastasis alone.

Methods:

Between January 2007 and July 2011 reviews were done for 82 patients with spinal metastasis who had not received a previous diagnosis of carcinoma. The assessment parameters included the following: general demographic data, Karnofsky score, Frankel score, number of spinal vertebra affected, region of the spine affected by metastasis, other skeletal metastasis site, visceral metastasis, known or unknown primary sites of metastasis, histological cell type of metastasis, and the survival period. The log-rank test and Cox proportional hazard model were used to study the survival analysis.

Results:

Of the 82 patients included in the study, 56 were male. The mean age was 57 years. 86.6% had a known primary carcinoma site while the remaining 13.4% had none. The two most common known carcinoma sites were the lung and biliary systems. Among the 11 unknown primary sites, the most common histological finding was adenocarcinoma. The mean survival period was 8.7 ± 11.7 months. The survival analysis revealed two statistically significant factors: the primary tumor site’s aggressiveness (P<0.005) and the presence of visceral metastasis (P<0.05).

Conclusion:

The prevalence of identifiable primary site was 86.6% and the most common site was the lungs followed by the biliary system. The primary carcinoma site’s aggressiveness and the presence of visceral metastasis were the factors associated with patient survival.

Prognostic factors and clinical outcomes in synovial sarcoma of the extremities

AIMS

To evaluate the clinical outcomes and identify which prognostic factors influence the clinical outcomes of synovial sarcoma patients at a tertiary university hospital in Thailand.

METHODS

Patients with synovial sarcoma of the extremities between 1997 and 2007 were reviewed from the database of the Musculoskeletal Oncology Unit, Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand.

RESULTS

Of 41 patients, 23 males (56%) and 18 females (44%) with a median age of 39 (range, 1-78 years), 18 (44%) had metastasis at the first diagnosis and 23 (56%) had only a localized tumor. The 5-year overall survival of all the patients was 36%; 64% in patients with localized disease and 0% in patients with metastasis at first diagnosis. In all 23 patients (56%) died of the disease at a median duration of 11 months (range 3-47 months). All patients with metastases died at a median 9 months (range 1-41 months). Metastasis at first diagnosis influenced overall survival for patients with synovial sarcoma (P < 0.001). According to a univariate analysis, the significant adverse factors were biphasic histological subtype and an inadequate surgical margin of the definitive surgery (P < 0.05).

CONCLUSION

Synovial sarcoma is still a disease with a poor prognosis. Distant metastasis at initial diagnosis is a significant adverse prognostic factor for overall survival. A biphasic histological subtype and an inadequate surgical margin are significant adverse prognostic factors in localized synovial sarcoma.

Tissue imprint for intra-operative evaluation of musculoskeletal tumors

OBJECTIVE

To evaluate the usefulness of an intra-operative tissue imprint as a role to provide a provisional diagnosis in patients with musculoskeletal tumors.

MATERIAL AND METHOD

118 patients underwent surgical treatment for musculoskeletal tumors. Tissue imprints from suspected tissues were conducted in all of the patients and the results were compared with the final permanent section.

RESULTS

The usefulness of the imprint slides (i.e., the diagnostic yield) was 88.14%. The respective, overall sensitivity, specificity, accuracy, positive and negative predictive value was 93.75%, 100%, 96.15%, 100% and 90.90%.

CONCLUSION

Tissue imprinting is a useful method for intra-operative evaluation of adequacy and provides a provisional diagnosis of the musculoskeletal tumors lesions.