Postoperative full leg radiographs exhibit less residual coronal varus deformity compared to intraoperative measurements in robotic arm-assisted total knee arthroplasty with the MAKO™ system.

PURPOSE: Robotic arm-assisted total knee arthroplasty (raTKA), currently a major trend in knee arthroplasty, aims to improve the accuracy of implant positioning and limb alignment. However, it is unclear whether and to what extent manual radiographic and navigation measurements with the MAKO™ system correlate. Nonetheless, a high agreement would be crucial to reliably achieve the desired limb alignment. METHODS: Thirty-six consecutive patients with osteoarthritis and a slight-to-moderate varus deformity undergoing raTKA were prospectively included in this study. Prior to surgery and at follow-up, a full leg radiograph (FLR) under weight-bearing conditions was performed. In addition, a computed tomography (CT) scan was conducted for preoperative planning. The hip-knee-ankle angle (HKA), mechanical lateral distal femur angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and joint line convergence angle (JLCA) were measured in the preoperative and follow-up FLR as well as in the CT scout (without weight-bearing) by three independent raters. Furthermore, the HKA was intraoperatively assessed with the MAKO™ system before and after raTKA. RESULTS: Significantly higher HKA values were identified for intraoperative deformity assessment using the MAKO system compared to the preoperative FLR and CT scouts (p = 0.006; p = 0.05). Intraoperative assessment of the HKA with final implants showed a mean residual varus deformity of 3.2° ± 1.9°, whereas a significantly lower residual varus deformity of 1.4° ± 1.9° was identified in the postoperative FLR (p < 0.001). The mMPTA was significantly higher in the preoperative FLR than in the CT scouts (p < 0.001). Intraoperatively, the mMPTA was adjusted to a mean of 87.5° ± 0.9° with final implants, while significantly higher values were measured in postoperative FLRs (p < 0.001). Concerning the mLDFA, no significant differences could be identified. CONCLUSION: The clinical importance of this study lies in the finding that there is a difference between residual varus deformity measured intraoperatively with the MAKO™ system and those measured in postoperative FLRs. This has implications for preoperative planning as well as intraoperative fine-tuning of the implant position during raTKA to avoid overcorrection of knees with slight-to-moderate varus osteoarthritis. LEVEL OF EVIDENCE: Level IV.

Arthroscopic lateral retinacular release improves patello-femoral and femoro-tibial kinematics in patients with isolated lateral retinacular tightness.

PURPOSE: Arthroscopic lateral retinacular release (LRR) has long been considered the gold standard for the treatment for anterior knee pain caused by lateral retinacular tightness (LRT). However, one-third of patients experience continuous pain postoperatively, which is thought to be related to persistent maltracking of the patella and altered femoro-tibial kinematics. Therefore, the aim of the present study was to simultaneously assess femoro-tibial and patello-femoral kinematics and identify the influence of arthroscopic LRR. METHODS: Sixteen healthy volunteers and 12 patients with unilateral, isolated LRT were prospectively included. Open MRI scans with and without isometric quadriceps contraction were performed in 0°, 30° and 90° of knee flexion preoperatively and at 12 months after surgery. Patellar shift, tilt angle, patello-femoral contact area and magnitude of femoro-tibial rotation were calculated by digital image processing. RESULTS: Postoperatively, patellar shift was significantly reduced at 90° of knee flexion compared to preoperative values. The postoperative patellar tilt angle was found to be significantly smaller at 30° of knee flexion compared to that preoperatively. Isometric muscle contractions did not considerably influence patellar shift or tilt in either group. The patello-femoral contact area increased after LRR over the full range of motion (ROM), with significant changes at 0° and 90°. Regarding femoro-tibial kinematics, significantly increased femoral internal rotation at 0° was observed in the patient group preoperatively, whereas the magnitude of rotation at 90° of knee flexion was comparable to that of healthy individuals. The pathologically increased femoral internal rotation at 30° without muscular activity could be significantly decreased by LRR. With isometric quadriceps contraction no considerable improvement of femoral internal rotation could be achieved by LRR at 30° of knee flexion. CONCLUSIONS: Patello-femoral and femoro-tibial joint kinematics could be improved, making LRR a viable surgical option in carefully selected patients with isolated LRT. However, pathologically increased femoral internal rotation during early knee flexion remained unaffected by LRR and thus potentially accounts for persistent pain. LEVEL OF EVIDENCE: II.

Intramedullary Fixation of Double-Barrel Vascularised Fibula Grafts With Subsequent Lengthening for Reconstruction of the Distal Femur in Patients With Osteosarcoma.

BACKGROUND: The use of vascularised fibula grafts is an accepted method for reconstructing the distal femur following resection of malignant childhood tumors. Limitations relate to the mismatch of the cross-sectional area of the transplanted fibula graft and the local bone, instability of the construct and union difficulties. We present midterm results of a unique staged technique-an immediate defect reconstruction using a double-barrel vascularised fibula graft set in in A-frame configuration and a subsequent intramedullary femoral lengthening. METHODS: We retrospectively included 10 patients (mean age 10 y) with an osteosarcoma of the distal femur, who were treated according to the above-mentioned surgical technique. All patients were evaluated with regards to consolidation of the transplanted grafts, hypertrophy at the graft-host junctions, leg length discrepancies, lengthening indices, complications as well as functional outcome. RESULTS: The mean defect size after tumor resection was 14.5 cm, the mean length of the harvested fibula graft 22 cm, resulting in a mean (acute) shortening of 4.7 cm (in 8 patients). Consolidation was achieved in all cases, 4 patients required supplementary bone grafting. Hypertrophy at the graft-host junctions was observed in 78% of the evaluable junctions. In total 11 intramedullary lengthening procedures in 9 patients had been performed at the last follow up. The mean Muskuloskeletal Society Rating Scale (MSTS) score of the evaluable 9 patients was 85% (57% to 100%) with good or excellent results in 7 patients. CONCLUSIONS: A-frame vascularised fibula reconstructions showed encouraging results with respect to defect reconstruction, length as well as function and should therefore be considered a valuable option for reconstruction of the distal femur after osteosarcoma resection. The surgical implementation is demanding though, which is emphasized by the considerable high number of complications requiring surgical intervention, even though most were not serious. LEVEL OF EVIDENCE: Level IV-case series.

Soft tissue masses: distribution of entities and rate of malignancy in small lesions.

BACKGROUND: Small soft tissue masses are often falsely assumed to be benign and resected with failure to achieve tumor-free margins. Therefore, this study retrospectively investigated the distribution of histopathologic diagnosis to be encountered in small soft tissue tumors (≤ 5 cm) in a large series of a tertiary referral center. METHODS: Patients with a soft tissue mass (STM) with a maximum diameter of 5 cm presenting at our institution over a period of 10 years, who had undergone preoperative Magnetic resonance imaging and consequent biopsy or/and surgical resection, were included in this study. A final histopathological diagnosis was available in all cases. The maximum tumor diameter was determined on MR images by one radiologist. Moreover, tumor localization (head/neck, trunk, upper extremity, lower extremity, hand, foot) and depth (superficial / deep to fascia) were assessed. RESULTS: In total, histopathologic results and MR images of 1753 patients were reviewed. Eight hundred seventy patients (49.63%) showed a STM ≤ 5 cm and were therefore included in this study (46.79 +/- 18.08 years, 464 women). Mean maximum diameter of the assessed STMs was 2.88 cm. Of 870 analyzed lesions ≤ 5 cm, 170 (19.54%) were classified as superficial and 700 (80.46%) as deep. The malignancy rate of all lesions ≤ 5 cm was at 22.41% (superficial: 23.53% / deep: 22.14%). The malignancy rate dropped to 16.49% (20.79% / 15.32%) when assessing lesions ≤ 3 cm (p = 0.007) and to 15.0% (18.18% / 13.79%) when assessing lesions ≤ 2 cm (p = 0.006). Overall, lipoma was the most common benign lesion of superficial STMs (29.41%) and tenosynovial giant cell tumor was the most common benign lesion of deep STMs (23.29%). Undifferentiated pleomorphic sarcoma was the most common malignant diagnosis among both, superficial (5.29%) and deep (3.57%) STMs. CONCLUSIONS: The rate of malignancy decreased significantly with tumor size in both, superficial and deep STMs. The distribution of entities was different between superficial and deep STMs, yet there was no significant difference found in the malignancy rate.

COVID-19-related cancellation of elective orthopaedic surgery caused increased pain and psychosocial distress levels.

PURPOSE: Health care systems in most European countries were temporarily restructured to provide as much capacity as possible for the treatment of coronavirus disease 2019 (COVID-19) patients. Subsequently, all elective surgeries had to be cancelled and postponed for months. The aim of the present study was to assess the pretreatment health status before and after COVID-19-related cancellation and the psychosocial distress caused by the cancellation. METHODS: For this study, a questionnaire was developed collecting sociodemographic data and information on health status before and after the cancellation. To assess psychosocial distress, the validated depression module of the Patient Health Questionnaire (PHQ-9), was implemented. PHQ-9-Scores of 10 and above were considered to indicate moderate or severe depressive symptoms. In total, 119 patients whose elective orthopaedic surgery was postponed due to the COVID-19 pandemic were surveyed once at least 8 weeks after the cancellation. RESULTS: Seventy-seven patients (65%; 34 female, 43 male) completed the questionnaire and were included. The predominant procedures were total knee arthroplasty (TKA), hip arthroscopy and foot and ankle surgery. The mean pain level significantly increased from 5.5 ± 2.2 at the time of the initially scheduled surgery to 6.2 ± 2.5 at the time of the survey (p < 0.0001). The pain level before cancellation of the surgery was significantly higher in female patients (p = 0.029). An increased analgetic consumption was identified in 46% of all patients. A mean PHQ-9 score of 6.1 ± 4.9 was found after cancellation. PHQ-9 scores of 10 or above were found in 14% of patients, and 8% exhibited scores of 15 points or above. Significantly higher PHQ-9 scores were seen in female patients (p = 0.046). No significant differences in PHQ-9 scores were found among age groups, procedures or reasons for cancellation. CONCLUSION: Cancellation of elective orthopaedic surgery resulted in pain levels that were significantly higher than when the surgery was scheduled, leading to increased analgesic use. Additionally, significant psychosocial distress due to the cancellation was identified in some patients, particularly middle-aged women. Despite these results, confidence in the national health care system and in the treating orthopaedic surgeons was not affected. LEVEL OF EVIDENCE: Level III.

Syme Amputation: Function, Satisfaction, and Prostheses.

BACKGROUND: Syme amputation (SA) is a term used to describe an amputation at the level of the ankle joint in which the heel pad is preserved. It is performed for a number of indications in a pediatric population. SA is purported to hold the advantage of allowing weight bearing without a prosthesis. A limb length discrepancy (LLD) is useful for ambulation without a prosthesis but can be restrictive with regards to the fitting of modern prostheses. METHODS: A voluntary survey was distributed to persons living with SA. Recruitment occurred through hospital electronic database and electronic advertising. Data collected included baseline demographic information, data pertaining to weight bearing in different environments, as well as 2 validated outcome measures: the Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R activity restriction scale) and the Locomotor Capabilities Index-5 (LCI-5). An illustration was designed to allow participants to classify their LLD by zone in relation to their nonamputated limb. RESULTS: At total of 47 persons living with SA participated. The average age at amputation was 3.7 years (range, 0.5 to 14.1 y), and at survey completion 15.8 years (1.7 to 60.3). Five of the described "zones" of LLD were represented. Average LCI-5 score was 52.6. Mean TAPES-R activity restriction scale was 0.59, the lowest mean being achieved by zone E participants, indicating the least restriction. Ability to walk without a prosthesis was lower in those participants over 11 years, when compared with those under, as well as being dependent on the walking environment. CONCLUSIONS: Our study found no trend indicating that a very low LLD was functionally optimal, and indeed found participants with a moderate LLD (zone E) to have the least mean restriction with regard to their prosthesis. Our study demonstrates that ambulation without a prosthesis depends on the environment (ie, flooring), and rates decrease significantly into adulthood. Optimal care should not focus simply "preserving length," but rather functional optimization and length modulation in parallel with a nuanced understanding of actual daily activities and prosthetic options. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

[Amputations around the knee]. / Kniegelenknahe Amputationen.

An amputation around, through or below the knee joint constitutes a "huge" change in a patient's life. In Orthopaedics, amputations are most frequently performed in cases with musculoskeletal tumours or failed total knee arthroplasty. A multidisciplinary team approach (surgeon, anaesthetist, pain specialists, orthotist, psychologist etc.) and patient-specific treatment regime from the outset as well as a meticulous surgical technique are of the outmost importance. Nowadays, prosthetic legs can be fitted for nearly any amputation level. The functional outcome of amputations below the knee is usually superior to amputations above or through the knee joint. Postoperative stump conditioning is paramount and the final prosthetic leg should not be fitted earlier than 4-6 months postoperatively. Problems with wound healing, muscle contractures and phantom limb pain represent common complications which might adversely affect patient outcomes.

Differentiating atypical lipomatous tumors from lipomas with magnetic resonance imaging: a comparison with MDM2 gene amplification status.

BACKGROUND: To evaluate the diagnostic value of MR imaging for the differentiation of lipomas and atypical lipomatous tumors (ALT) in comparison with histology and MDM2 amplification status. METHODS: Patients with well-differentiated lipomatous tumors (n = 113), of which 66 were diagnosed as lipoma (mean age 53 years (range, 13-82); 47% women) and 47 as atypical lipomatous tumor (ALT; mean age 60 years (range, 28-88); 64% women), were included into this study using histology and MDM2 amplification status by fluorescence in situ hybridization (FISH) as standard of reference. Preoperative MR images were retrospectively assessed by two radiologists for the following imaging features: maximum tumor diameter (mm) as well as the affected compartment (intramuscular, intermuscular or subcutaneous), septa (absent, thin (< 2 mm) or thick septa (> 2 mm) with nodular components); contrast enhancing areas within the lipomatous tumor (< 1/3 of the tumor volume, > 1/3 of the tumor volume); RESULTS: Of the 47 patients with ALT, 40 (85.1%) presented thick septa (> 2 mm) and this finding significantly increased the likelihood of ALT (OR 6.24, 95% CI 3.36-11.59; P < 0.001). The likelihood of ALT was increased if the tumor exceeded a maximum diameter of 130.0 mm (OR 2.74, 95% CI 1.82-4.11, P < 0.001). The presence of contrast enhancement in lipomatous tumors significantly increased the likelihood of ALT (Odds ratio (OR) 2.95, 95% confidence interval (CI) 2.01-4.31; P < 0.001). Of the lipomas, 21.1% were located subcutaneously, 63.6% intramuscularly and 15.2% intermuscularly. On the other hand, none of the ALTs were located subcutaneously, the majority was located intermuscularly (87.3%) and a small number of ALTs was located intramuscularly (12.7%). CONCLUSIONS: Our results suggest that using specific morphological MR imaging characteristics (maximum tumor diameter, thick septa and contrast enhancement) and the information on the localization of the lipomatous tumor, a high sensitivity and substantial specificity can be achieved for the diagnosis of lipomas and ALTs.

Distribution patterns of foot and ankle tumors: a university tumor institute experience.

BACKGROUND: Bone and soft tissue masses of the foot and ankle are not particularly rare but true neoplasia has to be strictly differentiated from pseudotumorous lesions. Diagnosis is often delayed as diagnostic errors are more common than in other regions. Awareness for this localization of musculoskeletal tumors is not very high and neoplasia is often not considered. The purpose of this study is to provide detailed information on the incidence and distribution patterns of foot and ankle tumors of a university tumor institute and propose a simple definition to facilitate comparison of future investigations. METHODS: As part of a retrospective, single-centre study, the data of patients that were treated for foot and ankle tumors between June 1997 and December 2015 in a musculoskeletal tumor centre were analyzed regarding epidemiologic information, entity and localization. Included were all cases with a true tumor of the foot and ankle. Exclusion criteria were incomplete information on the patient or entity (e.g. histopathological diagnosis) and all pseudotumoral lesions. RESULTS: Out of 7487 musculoskeletal tumors, 413 cases (5,52%) of tumors of the foot and ankle in 409 patients were included (215 male and 198 female patients). The average age of the affected patients was 36 ± 18y (min.3y, max.92y). Two hundred sixty-six tumors involved the bone (64%), among them 231 (87%) benign and 35 (13%) malignant. There were 147 soft tissue tumors (36%), 104 (71%) were benign, 43 (29%) malignant. The most common benign osseous tumor lesions included simple bone cysts, enchondroma and osteochondroma. By far the most common malignant bone tumor was chondrosarcoma. Common benign soft tissue tumors included pigmented villo-nodular synovitis, superifcial fibromatosis and schwannoma whereas the most common malignant members were synovial sarcoma and myxofibrosarcoma. Regarding anatomical localization, the hindfoot was affected most often. CONCLUSIONS: Knowledge of incidence and distribution patterns of foot and ankle tumors will help to correctly assess unclear masses and initiate the right steps in further diagnostics and treatment. Unawareness can lead to delayed diagnosis and inadequate treatment with serious consequences for the affected patient.

Prognostic factors and outcome of Liposarcoma patients: a retrospective evaluation over 15 years.

BACKGROUND: Soft tissue sarcomas are rare entities with over 50 histological subtypes. Liposarcoma (LS) is the most common neoplasm in this group; it is a complex neoplasm that is divided into different histological subtypes. Different therapy options, such as surgical resection, radiation, and chemotherapy, are available. Depending on the subtype, location, status of the resection margins and metastatic status, different therapy options are used. Therefore, the aim of this study was to determine the prognostic factors influencing the survival of patients affected by LS with consideration for the grading, histological subtype, state of the resection margin, size, location, metastases and local recurrence in a retrospective, single-centre analysis over 15 years. METHODS: We included 133 patients (male/female = 67/66) in this study. We recorded the histologic subtype, grade, TNM classification, localization, biopsy technique, tumour margins, number of operations, complications, radiation and dose, chemotherapy, survival, recrudescence, metastases and follow-up. Survivorship analysis was performed. RESULTS: We detected 56 (43%; 95%-CI 34.6-51.6%) atypical LS cases, 21 (16.2%; 95%-CI 9.8-22.5) dedifferentiated LS cases, 40 (30.8%; 95%-CI 22.8-38.7) myxoid LS cases and 12 (9.2%; 95%-CI 4.3-14.2) pleomorphic LS cases. G1 was the most common grade, which was followed by G3. Negative margins (R0) were detected in 67 cases (53.6%; 95%-CI 44.9-62.3) after surgical resection. Local recurrence was detected in 23.6% of cases. The presence of metastases and dedifferentiated LS subtype as well as negative margins, grade and tumour size are significant prognostic factors of the survival rates (p < 0.015). CONCLUSION: Grading, LS subtype, negative margins after surgery, metastases and tumour size are independently associated with disease-specific survival, and patients with local recurrence had lower survival rates. We hope our investigation may facilitate a further prospective study and clinical decision-making in LS.

Non-vascularised fibula grafts for reconstruction of segmental and hemicortical bone defects following meta- /diaphyseal tumour resection at the extremities.

BACKGROUND: The reconstruction of meta-/diaphyseal bone defects following bone tumour resection is challenging, and biological treatment options should be applied whenever possible, especially in benign lesions and early stage sarcomas. We aimed to evaluate the results of segmental (SR) and hemicortical reconstructions (HR) at the extremities using non-vascularised fibula grafts. METHODS: We retrospectively enrolled 36 patients who were treated with non-vascularised fibula reconstructions (15 SR, 21 HR) after bone tumour resection (15 malignant, 21 benign). All cases were evaluated regarding consolidation, hypertrophy at the graft-host junctions, and complications; moreover, the functional and oncological results were assessed. The mean follow-up was 8.3 years (2.1-26.6 years). RESULTS: Primary union was achieved in 94% (SR 87%, HR 100%) of patients, and 85% (SR 81%, HR 88%) showed hypertrophy at the graft-host junction. The overall complication rate was 36% with 4 patients (11%) developing local recurrence. There was a significant correlation between the development of mechanical complications (fracture, delayed-/non-union) and a defect size of ≥12 cm (p = 0.013), segmental defects (p = 0.013) and additional required treatment (p = 0.008). The functional outcome was highly satisfactory (mean MSTS score 86%). CONCLUSIONS: Due to encouraging results and advantages (such as their remodelling capacity at the donor site), non-vascularised fibula reconstructions should be considered a valuable alternative treatment option for patients with hemicortical defects or segmental reconstructions of less than 12 cm in which no additional neo-/adjuvant treatment is necessary.

Distal femoral replacement with the MML system: a single center experience with an average follow-up of 86 months.

BACKGROUND: The aim of this study was to compare the functional outcomes and complication rates after distal femoral replacement (DFR) performed with the modular Munich-Luebeck (MML) modular prosthesis (ESKA/Orthodynamics, Luebeck, Germany) in patients being treated for malignant disease or failed total knee arthroplasty. METHODS: A retrospective review of patient charts and a functional investigation (involving Musculoskeletal Tumor Society Score [MSTS], American Knee Society Score [AKSS], Oxford Knee Score [OKS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Toronto Extremity Salvage Score [TESS], the 12-Item Short-Form [SF-12] Health Survey, and a failure classification system developed by Henderson et al.) of DFR cases from 2002 to 2015 were conducted. The indications for DFR were malignant tumor resection in the femur (n = 20, group A) or failure of revision total knee arthroplasty without a history of malignant disease (n = 16, group B). RESULTS: One-hundred and twenty-nine patients were treated during the study period. Of these, 82 were analyzed for complications and implant-survival. Further, 36 patients were available for functional assessment after a mean follow-up of 86 months (range: 24-154). There were 75 complications in total. The overall failure rate for DFR was 64.6% (53/82 patients). The most common failure mechanisms were type III (mechanical failure), followed by type I (soft tissue) and type II (aseptic loosening). The mean MSTS score (out of 30) was 17 for group A and 12 for group B. All the clinical outcome scores revealed an age-dependent deterioration of function. CONCLUSION: DFR is an established procedure to restore distal femoral integrity. However, complication rates are high. Post-procedure functionality depends mainly on the patient's age at initial reconstruction.

Short- to long-term follow-up of total femoral replacement in non-oncologic patients.

BACKGROUND: Compromised bone stock and heavily impaired structural integrity after multiple endoprosthetic revision surgeries can lead to a comparable condition as encountered in musculoskeletal tumor surgery. Total femoral replacement (TFR) can restore femoral integrity and allow patients to resume ambulation. Even though several authors reported their results of TFR, so far many questions are still on debate: Which patients are at risk to experience low functional outcome? Do complications and clinical outcome after TFR depend on the indication for the surgery (e.g. periprosthetic fractures or aseptic loosening) or the age of the patients? The purpose of the present study was to compare complication rates after TFR performed with modular total femur prosthesis MML (Fa. ESKA/Orthodynamics) in patients without malignant disease. METHODS: We conducted a retrospective chart review and functional investigation of patients treated with a TFR for non-oncologic conditions from 1995 to 2015 and a minimum follow-up of 2 years. Complications were recorded according to the Henderson-Classification; outcome was evaluated with established clinical scores. The indication for TFR was periprosthetic fracture (Group A, n = 11) or aseptic loosening (Group B, n = 7) with massive bone defect of the femur deemed unsuitable for conventional arthroplastic or biologic reconstruction. RESULTS: Eighteen patients matched the inclusion criteria and could be investigated clinically after a mean follow-up of 80 months (range: 28-132). Before TFA, all patients had previously undergone multiple operations (range: 1-8). The overall failure rate for any reason was 72% (n = 13/18), leading to a total of 37 surgical revisions with total exchange of TFR in 22% (n = 4/18). Most common failure mechanism was Type I (soft tissue), followed by Type IV (infection) and Type III (mechanical failure). According to Enneking's functional evaluation method (MSTS-Score), the function ranged from 1 to 15 with a mean of 10 ± 4 out of 30. CONCLUSION: TFR is a salvage procedure to restore mechanical integrity and regain functional ability after extensive femoral bone loss. Outcome of the patients in the present study did mainly depend on the age at reconstruction and not on the indication for TFR.

Glucosamine sulfate suppresses the expression of matrix metalloproteinase-3 in osteosarcoma cells in vitro.

BACKGROUND: Glucosamine, a common dietary supplement, has a possible anti-sarcoma effect. However, an understanding of the underlying mechanism of such an effect is limited. For this study we hypothesized that glucosamine suppresses the basal level of matrix metalloproteinase expression in human osteosarcoma cell lines. METHODS: We examined the osteosarcoma cell lines, MG-63 and SaOS-2. Cells were exposed to 0, 10, 50 and 100 µg/ml glucosamine sulfate for 48 h and treatment toxicity was determined through measurement of cell viability and proliferation. Relative gene expression of matrix metalloproteinase (MMP)-2, -3 and -9 was quantified by real-time polymerase chain reaction. Protein levels of MMP-2 and -9 were assessed by ELISA. RESULTS: Administration of 10, 50 or 100 µg/ml glucosamine sulfate had no effect on the cell viability of MG-63 and SaOS-2 cells. A significant reduction of MMP expression in both cell lines was observed only for MMP-3, while a decrease in MMP-9 was seen in SaOS-2 cells. The expression of MMP-2 was not significantly affected in either cell line. Protein level of MMP-3 was reduced in both cell lines upon stimulation with 10 µg/ml glucosamine sulfate whereas for MMP-9 a decrease could only be observed in SaOS-2 cells. CONCLUSION: In this study, we found a pronounced suppressive effect of glucosamine sulfate particularly on MMP-3 and also MMP-9 mRNA and protein levels in osteosarcoma cell lines in vitro. The data warrants further investigations into the potential anti-tumor efficacy of glucosamine sulfate in osteosarcoma.

Clinical improvement and satisfaction after total joint replacement: a prospective 12-month evaluation on the patients' perspective.

PURPOSE: To determine short-term improvements, satisfaction rates and the patient acceptable symptom state (PASS) after total joint replacement (TJR) for different patient-reported outcome measures (PROMs). METHODS: This prospective cohort study included 426 consecutive patients undergoing total hip (n = 193) or knee arthroplasty (n = 233). The following PROMs were completed before TJR, and at 3, 6 and 12 months after surgery, respectively: WOMAC, Oxford Hip or Knee Score, Lower Extremity Functional Scale, University of California at Los Angeles (UCLA) activity scale and EuroQol-5 dimension (EQ-5D). Satisfaction rates and the PASS thresholds were also assessed. RESULTS: THA patients improved quicker and achieved higher outcome scores than TKA patients. Comorbidities according to the Sangha score were moderately correlated with all PROM values in an inverse direction at all time points (r = -0.27 to -0.47, p < 0.01) in both groups. Satisfaction with the result of surgery improved over time. At 12 months, more than 90 % of the patients were satisfied or very satisfied with the achieved result. The THA group showed a higher proportion of very satisfied patients than the TKA group at all time points. PASS thresholds increased over time for all PROMs except for the UCLA and the EQ-5D in TKA patients. CONCLUSIONS: More than 90 % of the patients will be satisfied 1 year after TJR. THA patients recover faster than TKA patients, i.e., they achieve higher PROM values at earlier follow-up time points. Cutoff values defining a successful result in terms of the PASS could be defined for all PROMs at different time points and can serve as reference for future studies and patient-oriented follow-ups.

Bilateral diaphyseal bone cysts of the tibia mimicking shin splints in a young professional athlete--a case report and depiction of a less-invasive surgical technique.

BACKGROUND: Medial tibial stress syndrome is one of the most common causes of exertional leg pain in runners whereas musculoskeletal tumors and tumor-like lesions are rare encounters in orthopedic sports medicine practice. Unicameral (simple) bone cyst is a well-known tumor-like lesions of the bone typically affecting children and adolescents. Bilateral occurrence is very rare though and has never been reported before in both tibiae. Failing to accurately diagnose a tumorous lesion can entail far-reaching consequences for both patients and physicians. CASE PRESENTATION: We report the case of large bilateral unicameral bone cysts of the diaphyseal tibiae mimicking medial tibial stress syndrome in a 17-year old professional athlete. This is the first report of symmetric tibial unicameral bone cysts in the literature. The patient complained about persisting shin splint-like symptoms over 5 months despite comprehensive conservative treatment before MRI revealed extensive osteolytic bone lesions in both diaphyseal tibiae. The patient-tailored, less-invasive surgical procedure, allowing the patient to return to his competitive sports level symptom-free 3 months after surgery and to eventually qualify for this years Biathlon Junior World Championships, is outlined briefly. Pathogenesis and various treatment options for this entity will be discussed. CONCLUSION: This report will help to raise awareness for musculoskeletal tumors as differential diagnosis for therapy-refractory symptoms in young athletes and encourage medical staff involved in sports medicine and athlete support to perform early high quality imaging and initiate sufficient surgical treatment in similar cases. Moreover, our less-invasive surgical procedure aiming for a fast return to sports might be an optimal compromise between traditional open curettage with low risk of recurrence and a soft tissue-saving and bone-sparing minimal-invasive technique.

Long-term functional outcome and quality of life following rotationplasty for treatment of malignant tumors.

BACKGROUND: Malignant bone tumors of the lower extremity are more frequently found in children and adolescents than in adults. Modern treatment regimens led to high limb salvage rates and offer the choice between endoprosthetic replacement and rotationplasty in many cases. Rotationplasty has proven to be an effective, highly functional option in short- and mid-term studies. Aim of this study was to assess long-term results regarding quality of life and functionality after rotationplasty and to compare the obtained results to a representative healthy German sample cohort. METHODS: In total 12 patients who underwent rotationplasty between 1991 and 2001 were enrolled in this study. After physical examination, they were evaluated regarding health related quality of life, functional outcome and psychosocial status. While quality of life was mainly assessed using the SF-36 (The Short Form (36) Health Survey v2), functional outcome was measured using the musculoskeletal tumor society score (MSTS) as well as the Tegner activity level scale. RESULTS: Average age at the time of surgery was 19 ± 10 year. and 32 ± 11 year. at the time of follow up. Mean follow-up was 14 ± 9 years. The SF-36 scores accounted for 80.4 ± 15.7 regarding physical functioning, for 78.1 ± 24.1 regarding the physical role functioning, for 74.1 ± 17.6 regarding bodily pain and for 71.8 ± 26.1 regarding general health. SF-36 score for vitality was 75.0 ± 12.8, for social functioning 98.9 ± 3.6, 88.2 ± 23.9 for emotional role functioning and 89.6 ± 10.1 for the mental health. Comparison to a representative German sample cohort revealed significantly higher patient's scores for vitality, social functioning and mental health (p < 0.05). The overall MSTS resulted in an average of 64 ± 12 % and the Tegner activity level scale accounted for 4.1 ± 0.6 pts. CONCLUSIONS: The presented long-term results indicate that rotationplasty provides a high quality of life. Patients are satisfied with a good functional outcome regarding activities of daily life and even sports.

Unicameral Bone Cyst in the Calcaneus of Mirror Image Twins.

Unicameral bone cysts (UBCs) are benign tumor-like lesions that commonly occur in the diaphyseal or metaphyseal region of the long bones within the first 2 decades of life. Until today, the pathogenesis of UBC has been unclear, but mechanisms such as vascular occlusion or a response to trauma have been supposed. During the past decade, in particular, the genetic aspects of the development of this rare lesion have been discussed. We present the first case of mirror image monozygotic twins with a mirror image UBC of the calcaneus. Our findings reinforce the importance of additional studies to understand the significance of cytogenetic factors in the etiology of UBC.

[Insufficiency fractures after irradiation therapy - case series]. / Insuffizienzfrakturen nach Strahlentherapie : Eine Fallserie.

BACKGROUND: Radiation therapy plays an essential part in modern treatment regimes of musculoskeletal tumors. Nevertheless damage to the surrounding tissue does occur inevitably. Postradiogenic changes of bone are associated with decreased stability and an increased fracture rate. The orthopedic surgeon therefore faces a challenging situation with altered bone metabolism, changes in perfusion and soft tissue problems. PATIENTS/MATERIAL AND METHODS: We present 3 cases of radiation induced fractures during the treatment of soft tissue tumors, all of which received radiation doses of > 58 Gy. All fractures occurred over 1 year after the exposure to radiation in otherwise uneventful follow ups. RESULTS: Postoperative follow up showed fracture healing or in the case of the arthroplasty, osseous integration without further complications. CONCLUSIONS: Radiation doses of ≥ 58 Gy are a major risk factor for pathological fractures in long bones. Regardless of their low incidence, fracture rates between 1,2 and 6,4 % prove their importance. Local tumor control has therefore to be weighed against the resulting decrease in bone quality and stability. Treatment options should always take into consideration the increased risk for complications such as infection, pseudarthroses and wound healing disorders. Our results show that substitution of vitamin D and calcium as well as the the use of reamed intramedullary implants benefits the outcome.