Efficacy and safety of ultrasound-guided caudal epidural steroid injection in patients with low back pain and sciatica.

BACKGROUND: Fluoroscopy-guided caudal epidural steroid injection (EDSI) is an option for conservative treatment of low back pain and sciatica; however, repeated exposure to radiation is a concern. With the blind technique, the needle misplacement rate is 30%; hence, ultrasound-guided caudal EDSI is a favored option. OBJECTIVE: To determine the efficacy of ultrasound-guided EDSI for low back pain and sciatica. METHODS: One hundred and ten patients with low back pain and sciatica who were unresponsive to conservative treatment, were prospectively recruited. Ultrasound-guided caudal EDSI was administered at 0, 3, and 6 weeks. Visual Analog Scale (VAS) score was recorded at 0, 2, 4, 12, and 24 weeks. Patients completed the Roland-Morris Disability Questionnaire (RMDQ) at pre-injection and 24 weeks post-injection. RESULTS: VAS was significantly reduced at 2, 4, 12, and 24 weeks (p< 0.01). At 2, 4, 12, and 24 weeks after injection, 20%, 26%, 74%, and 83% of patients displayed > 50% VAS reduction, respectively. The mean pre-injection RMDQ score was 15 and that post-injection at 24 weeks was 7 (p< 0.01). The majority of patients had > 50% reduction in the RMDQ score. CONCLUSIONS: Ultrasound-guided EDSI was safe and efficacious for low back pain and sciatica treatment at the intermediate follow-up.

Prevalence of asymptomatic radiographic vertebral fracture in postmenopausal Thai women.

We aim to investigate the nationwide prevalence of asymptomatic radiographic vertebral fracture in Thailand. We found 29% of postmenopausal women had at least one radiographic vertebral fracture. The prevalence was significantly higher among women with osteoporosis at the total hip (TH) region which implies that TH bone mineral density is a determinant of vertebral fracture risk. INTRODUCTION: Radiographic vertebral fracture is associated with an increased risk of osteoporotic fracture and mortality in postmenopausal women. We designed a study to determine the prevalence of asymptomatic vertebral fractures in postmenopausal Thai women. METHODS: The study was designed as a cross-sectional investigation at five university hospitals so as to achieve representation of the four main regions of Thailand. Radiographs were taken from 1062 postmenopausal women averaging 60 years of age. The presence of vertebral fracture was assessed by the Genant's semiquantitative method with three independent radiologists. Respective bone mineral density was measured by dual-energy X-ray absorptiometry (DEXA) at the lumbar spine (LS), femoral neck (FN), and total hip (TH). RESULTS: Among the 1062 women, 311 were found to have at least one radiographic vertebral fracture-yielding a prevalence of 29% (95% CI 23.6-32.0%)-and 90 (8.5%, 95% CI 6.8-10.2%) had at least two fractures. The prevalence of vertebral fracture increased with advancing age. Most fractures occurred at one vertebra (71%) and only 29% at multiple vertebrae. The prevalence of vertebral fracture was significantly higher among women with osteoporosis compared with non-osteoporosis at the TH region. There was no significant difference in the prevalence among women with or without osteoporosis at the LS or FN. CONCLUSIONS: Radiographic vertebral fractures were common among Thai postmenopausal women (~ 29%). These findings suggest that approximately one in three postmenopausal women has undiagnosed vertebral fracture. Radiographic diagnosis should therefore be an essential investigation for identifying and confirming the presence of vertebral fractures.

Natural History and Prognostic Factors of Cholangiocarcinoma With Spinal Metastasis: A 10-Year Single Center Study.

STUDY DESIGN: This is a retrospective analysis. OBJECTIVE: The aim of this study was to determine the epidemiology, survival, and prognostic factors for cholangiocarcinoma (CCA) with spinal metastasis. SUMMARY OF BACKGROUND DATA: CCA is an epithelial cell malignancy of the bile duct, and a frequent site for its metastasis is the spine. Many areas of Asia are endemic for CCAs. To date, there is limited data on the epidemiology, natural history, and prognostic factors of CCA with spinal metastasis, which is crucial for better management and treatment of the disease. MATERIALS AND METHODS: Patients diagnosed with CCA were recruited to our study, in order to identify cases with spinal metastasis. The survival rate was estimated by the Kaplan-Meier method. The univariate and multivariate analyses of tumor-specific and spinal metastatic factors were performed to identify the independent factors that affect survival. RESULTS: From 2006 to 2015, 4585 CCA patients were identified and 182 of these patients had spinal metastasis. The overall median survival of patients with spinal metastasis was 88 days. Serum carcinoembryonic antigen <5 ng/mL, carbohydrate antigen 19-9 <39 U/mL, albumin ≥3.5 g/L, and Frankel score D-E were found to be independent factors that resulted in better survival in a multivariate Cox regression analysis. CCA resection or spinal surgery did not prolong the survival of patients with spinal metastasis. CONCLUSION: Spinal surgery should be considered for CCA patients with spinal metastasis, who have a favorable prognosis, and are likely to live long enough to benefit from surgery. The aim is to palliate the symptoms and not as much to improve the survival.

Survival rate and prognostic factors of conventional osteosarcoma in Northern Thailand: A series from Chiang Mai University Hospital.

BACKGROUND: Osteosarcoma is a common and aggressive primary malignant bone tumor occurring in children and adolescents. It is one of the most aggressive human cancers and the most common cause of cancer-associated limb loss. As treatment in Thailand has produced a lower survival rate than in developed countries; therefore, this study identified survival rate and the poor prognostic factors of osteosarcoma in Northern Thailand. METHODS: The retrospective cases of osteosarcoma, diagnosis between 1 January 1996 and 31 December 2013, were evaluated. Five and ten year overall survival rates were analyzed using time-to-event analysis. Potential prognostic factors were identified by multivariate regression analysis. RESULTS: There were 208 newly diagnosed osteosarcomas during that period, and 144 cases met the criteria for analysis. The majority of the osteosarcoma cases (78.5%) were aged 0-24 years. The overall 5- and 10-year survival rates were 37.9% and 33.6%, respectively. Presence of metastasis at initial examination, delayed and against treatment co-operation, and axial skeletal location were identified as independent prognostic factors for survival, with hazard ratios of 4.3, 2.5 and 3.8, and 3.1, respectively. CONCLUSIONS: This osteosarcoma cohort had a relatively poor overall survival rate. The prognostic factors identified would play a critical role in modifying survival rates of osteosarcoma patients; as rapid disease recognition, a better treatment counselling, as well as improving of chemotherapeutic regimens were found to be important in improving the overall survival rate in Thailand.

Second hip fractures at Chiang Mai University Hospital.

BACKGROUND: Hip fractures are a major public health problem. Patients who have suffered a hip fracture have an increased risk of a subsequent hip fracture. This study examines the incidence ofsecondhip fractures and attempts to identify underlying risk factors. OBJECTIVE: To examine the incidence ofsecond hip fractures in osteoporotic patients at Chiang Mai University Hospital and to identify risk factors related to second hip fractures. MATERIAL AND METHOD: A retrospective review was conducted of all low-energy mechanism hip fracture patients admitted during 2008 and 2009. Analysis of second hip fractures was conducted using survival analysis and logistic regression analysis. RESULTS: A total of 191 patients were observed for 391.68 person-years (mean 2.05 person-years per patient). Among that group, nine second hip fractures were identified, an overall incidence rate of 0.023 second fractures per person-year. Second hip fractures tended to occur within the first year following an initial hip fracture. There were no significant differences related to either gender or comorbid medical conditions. Logistic regression analysis revealed that increased risk of a second hip fracture was associated with age (highest between 80 to 89 years) and patients who were not treated for osteoporosis following their initial fracture. CONCLUSION: The incidence of second hip fractures at Chiang Mai University Hospital was 0.023 per person-year Careful follow-up of older patients, especially those over 80, and treatment ofosteoporosis with bisphosphonate plus vitamin D and calcium supplements was correlated with a reduction in the incidence of second hip fractures.

Factors related to mortality after osteoporotic hip fracture treatment at Chiang Mai University Hospital, Thailand, during 2006 and 2007.

OBJECTIVE: To investigate the one-year mortality rate after osteoporotic hip fracture and to identify factors associated with that mortality rate. MATERIAL AND METHOD: A retrospective review of 275 osteoporotic patients who sustained a low-trauma hip fracture and were admitted in Chiang Mai University Hospital during January 1, 2006 to December 31, 2007 was accomplished. Eligibility criteria were defined as age over 50 years, fracture caused by a simple fall and not apathologicalfracture caused by cancer or infection. Results of this one-year mortality rate study were compared to studies of hip fracture patient mortality in 1997 and the period 1998-2003. RESULTS: The average one-year mortality rate in 2006-2007 was 21.1%. Factors correlated with higher mortality were non-operative treatment, delayed surgical treatment, and absence of medical treatment for osteoporosis. The 2006-2007 mortality rate was slightly higher than for the 1997 and 1998-2003 periods. CONCLUSION: The one-year mortality rate after osteoporotic hip fracture of 21.1% was approximately 9.3 times the mortality rate for the same age group in the general population, indicating that treatment of osteoporosis as a means of helping prevent hip fracture is very important for the individual, the family, and society as a whole.

Extraskeletal chondroma on the sole of the foot.

UNLABELLED: A 47-year-old female presented with a solitary mass located in the plantar region of her left foot. The mass, which she noticed 2 years ago, grew gradually and caused increasing pain when bearing weight. Physical examination showed a 3.5-cm diameter tender nonmobile mass with firm consistency in the midplantar region. Radiographs showed a ring-like calcification compatible with cartilage tissue. Magnetic resonance imaging revealed a lobulated mass with a hypointense signal on T1-weighted images and a hyperintense signal on T2-weighted images in the mid-substance of the plantar fascia. After a skin incision was performed, the mass was dissected from the skin and subcutaneous tissue. Then, a marginal excision was performed. The histological assessment reported chondrocytes within lacunae embedded in a chondroid matrix with focal calcification. The definitive diagnosis was extraskeletal chondroma. Plantar pain resolved within 3 months and no recurrence was found at the 1-year follow-up. LEVEL OF EVIDENCE: Therapeutic Level IV, Case Report.

Femoral mechanical-anatomical angle of osteoarthritic knees.

BACKGROUND: To perform total knee arthroplasty, some surgeons prefer to use a fixed valgus angle, for example 5° or 6°, for the distal femoral cut with every patient. This angle may be appropriate for some patients, but may not be for all. OBJECTIVE: To determine the proper angle of the distal femoral cut during total knee arthroplasty (TKA) in Thai patients with osteoarthritis of the knee. MATERIAL AND METHOD: A cross-sectional study was conducted of 80 osteoarthritic knees of 50 Thai patients with a mean age of 69 years (range 52-82, SD 7.64) who had received total knee arthroplasty at Chiang Mai University Hospital between January 2011 and March 2013. The femoral mechanical-anatomical (FMA) angle, femorotibial (FT) angle, mechanical femorotibial (MFT) angle, femoral bowing angle, femoral length, hip offset, gender, and age of the patients were analysed using multivariate regression analysis. RESULTS: Average FMA angle was 6.46° (range 4°-10°, SD 1.26°). The FMA angle was 6.85° and 5.28° in patients with varus and valgus deformity, respectively. Fifteen percent of all patients showed a FMA angle either less than 5° or greater than 7°. CONCLUSION: The average FMA angle of patients with gonarthrosis was 6.46°. If it is not possible to measure the FMA angle in Thai patients, 7° valgus cut angle is recommended for patients with varus deformity. Variation in this angle was high. Pre-operative measurement of FMA angle is beneficial for precise TKA.

Changes in the serum cartilage biomarker levels of healthy adults in response to an uphill walk.

INTRODUCTION: To prevent long-term unfavourable consequences to the articular cartilage of weight-bearing joints, serum biomarkers can be used to identify optimum loading of activities. This study aimed to investigate the circulation pattern of serum cartilage biomarkers in healthy adults in response to an uphill walk. METHODS: This study recruited 58 healthy participants for the experimental group and 24 matched participants for the control group. Participants in the experimental group walked continuously for 14 km on a pathway with a 5.97° incline, while participants from the control group walked on a horizontal pathway. Serum was collected from both groups preactivity (i.e. T1), immediately after activity (i.e. T2) and 24 hours after T1 (i.e. T3). The serum cartilage oligomeric matrix protein (COMP), chondroitin sulfate-WF6 (WF6) and hyaluronic acid (HA) levels at each time point were quantified using enzyme-linked immunosorbent assays, and the results analysed. RESULTS: Both groups shared similar demographic characteristics and activity duration. At T2, the serum COMP level of the experimental group was significantly higher than that of the control group, but the serum HA level of the experimental group was significantly lower than that of the control group. No significant difference between the serum WF6 levels of the experimental and control groups was observed at T2. CONCLUSION: Increasing levels of serum COMP demonstrate articular cartilage susceptibility to the increasing load. An unsustainable, high serum COMP level and an undetectable change in WF6 level were considered to be a reversible physiological change of the cartilage. A change in ser um HA level could be related to intensive physical activity and dynamic clearance rather than a change in cartilage structure.

Extraosseous osteosarcoma: a case report and review of the literature.

Extraosseous osteosarcoma (EOO) is a rare soft tissue sarcoma that produces osteoid and bone. It is sometimes accompanied by cartilage. It is located in soft tissue without skeletal attachment. A previous study revealed that extraosseous osteosarcoma is a chemoresistant tumor with a poor prognosis and should be distinct from osseous osteosarcoma. Out of more than a hundred of osteosarcoma recorded during 1992 to 2012 in Chiang Mai Hospital, only one was EOO. This is a case report of a 44-year-old Asian man who first noticed a small right thigh soft tissue mass associated with pain. MRI reveals a heterogeneous mass in the quadriceps muscle without continuity with the bone. Wide resection of the tumor was performed. Microscopically, the tumors composed of large size spindle shape and bizarre malignant cell with osteoid production. After the resection, adjuvant radiation by brachytherapy technique, and chemotherapy was performed. At postoperative 24-months follow-up, the patient was free from local recurrence and distant metastasis, compared to seven months of median survival time for patients treated with resection alone in previous case reports.

Increasing incidence of hip fracture in Chiang Mai, Thailand.

Hip fracture is a major health problem in Thailand. This study attempted to examine the incidence, related factors, and trends of hip fracture in Chiang Mai, Thailand. All hip fracture data among patients aged 50 yr or older were collected from hospitals in Chiang Mai, Thailand from August 1, 2006 to July 3, 2007. Data from the 1997 Chiang Mai hip fracture study were used for comparison. In the study period, 690 hip fractures were reported: 203 males and 487 females (male to female ratio was 1 to 2.4), with a mean age of 76.7 yr. The estimated cumulative incidence was 181.0 per 100,000, and the adjusted incidence was 253.3 (males: 135.9; females: 367.9). A simple fall was the most common mechanism (79%) of fracture, and 80% of the hip fractures occurred in patients aged 70 yr or older. The highest incidence of hip fracture was observed in patients older than 85 yr (1239). At 6 mo postfracture, most patients (61%) used a walking aid. Compared with the 1997 data, hip fracture incidence had increased by an average of 2% per yr, and the incidence of hip fracture had increased significantly from August 1, 2006 to July 31, 2007, especially in patients older than 75 yr. In patients older than 84 yr, the incidence increased by a factor of 2. Urgent strategies for the prevention and treatment of osteoporosis, and hence hip fracture, are needed.

Result of extracorporeal irradiation and re-implantation for malignant bone tumors: a review of 30 patients.

AIMS: Extracorporeal irradiation and re-implantation (ECI) has been used as limb salvage surgery for musculoskeletal oncology patients. Biological reconstruction, no risk of disease transmission and immunological reaction, ready availability and preservation of bone stock are the major advantage of this surgical technique. This case series details the outcomes of ECI. METHODS: In total, 30 patients (31 sites) were treated with ECI between 1996 and 2007. The mean survivor follow-up period was 47 months (at least 24 and up to 108). The results of ECI were judged in terms of recurrence and limb function. Surgical failure was defined as local recurrence and the need for amputation, and reoperation for any reasons. Functional status was assessed by three functional assessment systems: Mankin score, the Musculoskeletal Tumor Society score (MTSS) and the Toronto Extremity Salvage score (TESS). RESULTS: In all, 24 patients (80%) were alive and free from disease at last follow up. Operative failure occurred in two cases (7%) and the main complication was infection in three cases (10%). The mean values of the MTSS and the TESS were 82% (57-98%) and 81% (57-99.), respectively. Excellent or good results were achieved in 27 patients (90%) according to the Mankin score. Patients classified as stage IA and IIA, upper extremity and ECI-prosthesis composite, mostly demonstrated excellent results without any complications. CONCLUSION: Our results are encouraging in terms of the orthopedic and oncological outcomes. This indicates that ECI offers a good alternative method for reconstruction in limb salvage surgery.

Hyaluronan production and chondrogenic properties of primary human chondrocyte on gelatin based hematostatic spongostan scaffold.

BACKGROUND: Autologous chondrocyte transplantation is a promising technique for treatment of cartilage defects. Three dimensional chondrocyte cultures on a scaffold are widely used to retain the chondrogenic phenotype. Using a biodegradable gelatin scaffold is one option for the cell delivery system, but molecular and histological studies of the method have not yet been done. METHODS: We evaluated the chondrogenic property of the primary human chondrocyte on a gelatin scaffold as compared to a collagen scaffold over a period of 21 days. We examined the production of glycosaminoglycan by quantitative and histological analysis. Gene expression of cartilage-associated molecules was assessed by quantitative RT-PCR. RESULTS: The gelatin scaffold showed the ability to promote chondrocyte expansion, chondrogenic phenotype retention at molecular and mRNA levels. CONCLUSIONS: This scaffold is thus suitable for use as an in vitro model for chondrocyte 3D culture.

Value and validation of RCOST and TOPF clinical practice guideline for osteoporosis treatment.

OBJECTIVE: To determine the percentage of postmenopausal women who need treatment using the various criteria as set out in clinical practice guideline published by the Royal College of Orthopaedic Surgeons of Thailand (RCOST) and the Thai Osteoporosis Foundation (TOPF). MATERIAL AND METHOD: A cross-sectional investigation conducted at five university hospitals around Thailand, evaluated three categories of criteria according to the RCOST and the TOPF guideline for treatment in postmenopausal women, (1) bone mineral density (BMID) measured by DXA, (2) combined quantitative ultrasonography (QUS) measurement and clinical risk indices (CRI), and (3) FRAX or CRI plus spine radiography. RESULTS: One thousand sixty two woman averaging 60 years of age were recruited for this study. Of those, women with osteoporosis according to DXA, osteopenia plus FRAX, or one major or two minor risk factors comprised between 1 and 22% (category I). Using the QUS T-score in combination with CRI (OSTA or KKOS score < or = -1) or nomogram criteria, between 11 and 14.4% needed treatment (category II). Using the BMI-based FRAX calculation or CRI (OSTA score of < -4 or KKOS probability of > or =80%) plus osteopenia by spine radiograph, between 2.6 and 15.7% needed treatment (category III). CONCLUSION: Using the RCOST and TOPF clinical practice guideline, only one-fifth of postmenopausal Thai women would be eligible to receive treatment.

Relationships between serum biomarker levels and clinical presentation of human osteosarcomas.

BACKGROUND: Currently, serum biomarkers play an important role as sensitive tools for monitoring the cancer development and progression. Each biomarker represents a specific pathogenesis and has different predictive capability. In order to identify their characteristics in human osteosarcoma, multiple potential biomarkers were analyzed simultaneously with clinical presentations. MATERIALS AND METHODS: Blood samples were collected from 28 osteosarcoma patients and 30 healthy matched controls. Specific clinical presentations were recorded, including: tumor volume, estimated based on three-dimensional MRI volumetric measurement; metastasis status; and histological cell types. Serum biomarkers analyzed by ELISA-based assays were bone-specific alkaline phosphatase (BALP), vascular endothelial growth factor (VEGF), hyaluronic acid (HA) and chondroitin sulfate WF6 (WF6). Serum lactate dehydrogenase (LDH) was analyzed by a photometric-based system. RESULTS: Serum BALP, LDH and WF6 levels of osteosarcoma patients were significantly higher than those of healthy controls, whereas HA and VEGF levels were not significantly different between the two groups. Serum BALP and LDH were positively correlated with tumor volume, (correlation coefficients 0.5 and 0.4, respectively). Serum BALP from metastasis and osteoblastic subtype group had a significantly higher level than that found in non-metastasis and non-osteoblastic subtypes group, respectively. Upon multivariate analysis, tumor volume was the only factor which correlated with BALP levels. CONCLUSION: Of the biomarkers analyzed in this study, serum BALP was the most reliable and sensitive for estimating tumor volume. A high level of serum WF6 reflects alteration of the extracellular matrix component of tumors. Both serum biomarkers can be expected to be further explored for use in specific clinical monitoring.

Recurrent tibial intra-cortical osteosarcoma: a case report and review of the literature.

INTRODUCTION: Intra-cortical osteosarcoma is the rarest subtype of osseous-producing tumor. Most reported cases present a low-grade histology with slow progression and good oncological control after adequate treatment. In this report, we describe a case and review the literature to propose adequate treatment. CASE PRESENTATION: We present the case of a 21-year-old Thai woman who was thought to have an intra-cortical osteosarcoma of the right tibia. We performed a wide resection and reconstruction with bone transportation using an Ilizarov external fixator. The tumor recurred five years later at the same site with a similar histology. We performed a new resection and reconstruction by ankle arthrodesis with adjuvant chemotherapy. At the last follow-up, she had remained active and free from disease for seven years. CONCLUSION: This case report of recurrent intra-cortical osteosarcoma describes an atypical presentation. The low-grade histology, adequate surgical margin and adjuvant chemotherapy of the recurrent lesion were favorable factors, and our patient has remained free of any tumor recurrence.

A survey of osteoporosis in Thailand.

This survey of osteoporotic opinion was conducted to 150 Thai physicians in every part of the country with 10 questionnaires. The details of the questions concentrated on the osteoporosis in the aspects of diagnosis, management, methods of assessment, common medicine for treatment. The most responder specialty was Orthopedist (79%), others were Gynecologist (3%), Rheumatologist (5%), Internist (5%), the others (7%) respectively. The diagnosis of osteoporosis used Dual-energy X-ray absorptiometry (DXA), (81%) in the case of this equipment as well as other methods (16%) are available. The per cent of other methods are X-ray, clinical symptoms, microdensitometry, QUS, biochemical bone markers and others: 30, 23, 13, 5, 3 and 6 respectively. About twenty-five percent of physicians took responses to 21-100 cases per month while two per cent of responders had more than 100 cases per month. The most common three ranking kinds of criteria were used for initiating medication for the treatment of osteoporosis that had low bone mineral density, signs of vertebral fracture, and menopause which they considered as the importance of prophylactic medication for patients. The continuation of medication depends on the following factors: experience of serious side effect (62%), affordable expense (53%) and stable bone mass (52%). The desirable features of anti-osteoporosis agents are stopped fracture, increasing BMD, cost effectiveness, side effect, stopped bone resorption, pain relieve and drug compliance respectively. Calcium is most commonly prescribed on condition that premenopausal and postmenopausal women have without fracture or with fracture: patients are elderly and treated with the prolonged steroid application. Bisphosphonates are widely used in case of fracture in every group. Alfacalcidol, vitamin D analog is the third prescription in the above conditions. Bisphosphonate, Calcium and Alfacacidol are the common kinds of combination under the above conditions. In addition, these kinds of drugs are commonly used for continuation after the remission therapy.

Effectiveness of intravenous bisphosphonate in treatment of giant cell tumor: a case report and review of the literature.

Giant cell tumor is a benign locally aggressive tumor. The standard treatment is en bloc resection followed by major reconstructive surgery, or extended curettage conjunction with bone grafting or the use of bone cement implantations. Surgical treatment of giant cell tumor at the sacrum is associated with high morbidity, and local recurrence. The authors present a case of giant cell tumor at the sacrum treated with intravenous 4 mg zoledronate every 4 weeks for seven courses followed with curettage and cement implantation. At two years follow-up, the patient had no pain, no neurological deficit, and no local recurrence. The patient's gait was normal. From the present study, the authors demonstrate the effectiveness of zoledronate for treatment of giant cell tumor at the sacrum. It can reduce the morbidity from major surgery.

Does the second-generation intercalary humeral spacer improve on the first?

UNLABELLED: Since publication of the results of a first-generation intercalary humeral spacer, a newer design has been available that addressed the weaknesses of the first. This study evaluated the hypothesis that the second-generation lap joint junction intercalary humeral spacer reduced complications compared with the original male-female taper design. We retrospectively reviewed the charts of 32 consecutive patients who had undergone placement of an intercalary humeral spacer. Twenty-one with the male-female taper (minimum followup 0 months, mean 19.2 months) were compared with 11 with the lap joint configuration (minimum followup 0 months, mean 20.3 months). Demographic, tumor, treatment, and radiographic variables were similar between groups. We observed a lower complication rate in the lap joint group (three of 11 versus 11 of 21). The most common complications in the male-female group, neuropraxia, periprosthetic fracture, and disengagement, were not seen in the lap joint group. Aseptic loosening was more frequent in the lap joint group. There were no differences in blood loss, operative time, or Musculoskeletal Tumor Society scores between groups. We noted improvement in Musculoskeletal Tumor Society scores from preoperatively to postoperatively in both groups. Use of these implants should be reserved for patients with limited life expectancy. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Successful canine patellar tendon reattachment to porous tantalum.

The ability to achieve reattachment of soft tissues, such as tendon, directly onto a prosthetic surface would be of great benefit in case of periarticular bone loss or resection. Bone and potential soft tissue ingrowth using porous tantalum has been observed in prior animal studies. We hypothesized porous tantalum washers used to reattach canine patellar tendon to bone would provide sufficient strength to withstand physiologic loading. We reattached the released patellar tendon to the tibia using two porous tantalum washers in 33 skeletally mature dogs. Force plate analysis of gait, tensile testing of the tendon reconstruction, and histologic analysis of tissue ingrowth into the implants were performed after 3, 6, and 12 weeks' survival. Physiologic weightbearing on the operated leg had normalized 6 weeks after tendon reconstruction surgery. The mechanical strength of the tendon reattachment was 76% of the strength of the native tendon insertion by 6 weeks but did not increase further with time. Fibrous tissue occupied approximately 1/2 of the available space in the porous tantalum washers at all times. Our data suggest tendon healing into a prosthetic material can be achieved using porous tantalum washers with sufficient mechanical strength to withstand physiologic loading.