Preoperative coagulation biomarkers associate with survival and pulmonary embolism after surgical treatment of non-spinal skeletal metastases.

BACKGROUND: Thrombotic complications are synergistic and associated with orthopedic procedures, trauma, and malignancy. Because cancer enhances coagulation activity and vice versa, we assessed preoperative biomarkers for survival and complications after treatment of pathologic fractures in non-spinal skeletal metastases. PATIENTS/METHODS: Our study population comprised 113 actual or impending pathologic fractures in 100 patients admitted to two referral centers. Laboratory variables were collected retrospectively from patient records and analyzed related to incidence of pulmonary embolism (PE) and mortality (Kaplan-Meier and Cox regression analyses and biomarker quartiles). RESULTS: Preoperative coagulation variables were high without exceptions. PE occurred in 12 patients at 36 post-operative days at incidence of 11% in the lower and 13% in the upper extremity fractures. Patients with fibrinogen exceeding 5 g/l (log-rank 0.022) developed PE earlier (5 to 15 days postoperatively) than others. Also, mean patient survival with normal fibrinogen range (2-4 g/l) was 34 months, whereas it halved upon elevated fibrinogen (log-rank p = 0.009). Survival in patients with FVIII levels under 326 IU/dl (Q3) was 22 months, but only 7 months if FVIII exceeded 326 IU/dl (log-rank p = 0.002). Combined elevated fibrinogen and FVIII predicted survival: for patients with levels below threshold limits was 22 months versus only 7 months when both variables exceeded the ranges (log-rank p < 0.001). Multivariate analysis to control confounders supported an independent role of fibrinogen and FVIII for survival. CONCLUSIONS: Our study has established fibrinogen and FVIII as potential preoperative contributors of survival and complications after treatment of metastatic fractures. These results highlight the need for novel anticoagulation and thromboprophylaxis strategies among these patients.

Surgical and patient-reported outcomes after total knee arthroplasty requiring soft tissue flap reconstruction - A 12-year experience from high-volume arthroplasty hospital.

BACKGROUND: This study investigates the outcomes of complex knee joint reconstructions performed by an orthoplastic surgery team at a tertiary referral hospital. METHODS: Retrospective review of all the total knee arthroplasty (TKA)/revision TKA (rTKA) procedures with soft tissue flap reconstruction performed between 2008 and 2019 was conducted. Patients were stratified into two groups according to the urgency of surgery: scheduled non-complicated (SNC) and emergent complicated (EC). The whole study cohort was also categorized into non-infected and infected groups. RESULTS: Of 20,184 TKAs operated, 58 patients required flap reconstruction (SNC group n = 27; EC group n = 31). The most common reconstruction was medial gastrocnemius flap (74%). Mean follow-up time was 31.9 months. Functional knee joint salvage was achieved in 96.3% the SNC group and in 80.6% the EC group patients (p = 0.07). Transfemoral amputation rates were 3.7% in the SNC group vs. 6.5% in the EC group (p = 0.36). Oxford Knee Score was 34.5 vs. 25.5 (p = 0.21), and range of motion was 100° vs. 93° (p = 0.37) in the SNC and EC groups, respectively. Superior functional knee joint salvage rates were achieved in the non-infected group compared to the infected group (97.1% vs. 75.0%, p = 0.004). However, the transfemoral amputation rate was nearly three-fold in the infected group (8.3% vs. 2.9%, p = 0.36). Estimated five-year survival with functional knee joint was higher in the non-infected group (p = 0.03). CONCLUSIONS: Both the SNC and EC groups had similar acceptable limb salvage rates, and functional and PROM outcomes. Infection reduces the probability of a functional knee joint after TKA and flap reconstruction.

Outcomes of the rotating hinge knee in revision total knee arthroplasty with a median follow-up of 6.2 years.

BACKGROUND: The purpose of this study was to determine the mid-term clinical, radiographic and health-related quality of life (HRQoL) outcomes and define the survival rate in patients who had undergone revision total knee arthroplasty (TKA) using the single rotating hinged knee (RHK) design. METHODS: Between January 2004 and December 2013, 125 revision TKAs were performed at our institution using the single RHK implant. We conducted both a retrospective analysis of prospectively collected outcome data of these patients and a prospective follow-up study of all 39 living patients (41 knees). The follow-up phase included an optional extra follow-up visit, PROM questionnaires, and plain radiographs. RESULTS: The ten-year Kaplan-Meier survival rate of the revision RHK knees was 81.7% (95% CI 71.9-91.6%) with re-revision for any reason as the endpoint. Overall, 15 knees (12% of the total) underwent re-revision surgery during the follow-up. The median follow-up was 6.2 years (range, 0-12.7 years) post-operatively for the baseline group. One mechanical hinge mechanism-related failure occurred without any history of trauma or infection. At the time of the final follow-up, the majority of patients evinced a fairly good clinical outcome measured with patient-reported outcome measures and none of the components were radiographically loose. CONCLUSION: We found that in patients undergoing complex revision TKA, fairly good functional outcome and quality of life can be achieved using an RHK implant. Further, it seems that in this type of patient cohort, revision TKA using an RHK implant relieves pain more than it improves ability to function. The NexGen® RHK design can be regarded as a suitable option in complex revision TKA.

Good mid-term outcome of the rotating hinge knee in primary total knee arthroplasty - Results of a single center cohort of 106 knees with a median follow-up of 6.3 years.

BACKGROUND: The prognosis of complex primary total knee arthroplasty (TKA) with severe deformity and ligament deficiency is not clear. There is a paucity of evidence in the current literature on treatment outcomes of the rotating hinge knee implants in primary TKA. The aim of this study was to determine the mid-term clinical, radiographic, and health-related quality of life (HRQoL) outcomes in patients who had undergone complex primary TKA using single hinged knee replacement. METHODS: In total, 106 complex primary TKAs (101 patients) were performed using the single rotating hinged knee (RHK) implant design at our institution between January 2004 and December 2013. We conducted a retrospective analysis of prospectively collected outcome data of these patients, obtaining also information on all possible revision surgeries from the Finnish Arthroplasty Register, and conducted a prospective follow-up study of all living patients. RESULTS: The 10-year Kaplan-Meier survival rate of the RHK knees was 91.6% (95% CI 86.0% to 97.2%) with revision for any reason as the endpoint. Overall, eight knees (7.5 %) underwent revision surgery during the follow-up. None of the unrevised RHK knees were radiographically loose. The majority of patients evinced good clinical outcome and quality of life as measured with patient reported outcome measures. CONCLUSION: The hinge knee replacement which was assessed current study can be regarded as a suitable option in complex primary TKA, provided adequate attention is paid to the correct indications and patient selection.

Surgical treatment of skeletal metastases in proximal tibia: a multicenter case series of 74 patients.

Background and purpose - The proximal tibia is a rare site for metastatic bone disease and is a challenging anatomical site to manage due to the proximity to the knee joint and poor soft tissue envelope. We investigated implant survival and complications of different surgical strategies in the treatment of proximal tibia pathological fractures.Patients and methods - The study comprised a 4 medical center, retrospective analysis of 74 patients surgically treated for metastases of the proximal tibia. Patient records were reviewed to identify outcome, incidence, and type of complications as well as contributing factors.Results - Reconstruction techniques comprised cement-augmented osteosynthesis (n = 33), tumor prosthesis (n = 31), and total knee arthroplasty with long cemented stems (n = 10). Overall implant survival was 88% at 6 months and 1 year, and 67% at 3 years. After stratification by technique, the implant survival was 82% and 71% at 1 and 3 years with tumor prosthesis, 100% at 1 and 3 years with total knee arthroplasty, and 91% at 1 year and 47% at 3 years with osteosynthesis. Preoperative radiotherapy decreased implant survival. Complications were observed in 19/74 patients. Treatment complications led to amputation in 5 patients.Interpretation - In this study, the best results were seen with both types of prothesis reconstructions, with good implant survival, when compared with treatment with osteosynthesis. However, patients treated with tumor prosthesis showed an increased incidence of postoperative infection, which resulted in poor implant survival. Osteosynthesis with cement is a good alternative for patients with short expected survival whereas endoprosthetic replacement achieved good medium-term results.

Complications and re-revisions after revisions of 528 metal-on-metal hips because of adverse reaction to metal debris.

Background and purpose - There is limited amount of evidence about optimal revision indications, technique, and implants when performing revision surgery for metal-on-metal (MoM) hip replacements due to adverse reaction to metal debris (ARMD). We assessed which factors are related to re-revisions and complications after a revision of MoM hip arthroplasty because of ARMD. We also aimed to provide information on optimal implants for these revisions.Patients and methods - 420 MoM total hip arthroplasties (THA) and 108 MoM hip resurfacings were implanted and later revised at our institution. We used Cox regression to analyze the factors associated with re-revisions and complications after a revision for ARMD.Results - A re-revision was performed on 27 THAs (6%) and 9 resurfacings (8%). The most common indication for re-revision was recurrent dislocation (20 hips, 4%). Complications not leading to re-revision were seen in 21 THAs (5%) and 6 resurfacings (6%). The most common complication was dislocation treated with closed reduction in 13 hips (2%). Use of revision head size > 36mm was associated with decreased risk for dislocations. Presence of pseudotumor, pseudotumor grade, pseudotumor size, or the choice of bearing couple were not observed to affect the risk for re-revision. Non-linear association was observed between preoperative cobalt and risk for re-revision.Interpretation - As dislocation was the most frequent post-revision complication, large head sizes should be used in revisions. Because size or type of pseudotumor were not associated with risk of re-revision, clinicians may have to reconsider, how much weight is put on the imaging findings when deciding whether or not to revise. In our data blood cobalt was associated with risk for re-revision, but this finding needs further assessment.

Modified Harrington's procedure for periacetabular metastases in 89 cases: a reliable method for cancer patients with good functional outcome, especially with long expected survival.

Background and purpose - The pelvis is the 3rd most common site of skeletal metastases. In some cases, periacetabular lesions require palliative surgical management. We investigated functional outcome, complications, and implant and patient survival after a modified Harrington's procedure.Patients and methods - This retrospective cohort study included 89 cases of surgically treated periacetabular metastases. All patients were treated with the modified Harrington's procedure including a restoration ring. Lesions were classified according to Harrington. Functional outcome was assessed by Harris Hip Score (HHS) and Oxford Hip Score (OHS). Postoperative complications, and implant and patient survival are reported.Results - The overall postoperative functional outcome was good to fair (OHS 37 and HHS 76). Sex, age, survival > 6 and 12 months, and diagnosis of the primary tumor affected functional outcome. Overall implant survival was 96% (95% Cl 88-100) at 1 year, 2 years, and 5 years; only 1 acetabular implant required revision. Median patient survival was 8 months (0-125). 10/89 patients had postoperative complications: 6 major complications, leading to revision surgery, and 4 minor complications.Interpretation - Our modified Harrington's procedure with a restoration ring to achieve stable fixation, constrained acetabular cup to prevent dislocation, and antegrade iliac screws to prevent cranial protrusion is a reliable reconstruction for periacetabular metastases and results in a good functional outcome in patients with prolonged survival. A standardized procedure and low complication rate encourage the use of this method for all Harrington class defects.

Declining Revision Burden of Metal-on-Metal Hip Arthroplasties.

BACKGROUND: Adverse reactions to metal debris (ARMD) have been a problem with metal-on-metal (MoM) hip systems for a decade. Unacceptably high revision rates have been described for both stemmed MoM total hip arthroplasties (THAs) and hip resurfacings. The aim of this study was to report survivorship and temporal trends of hip revisions in patients with MoM hips. METHODS: We identified 2520 patients with 3013 MoM hip arthroplasties performed at our institution. These included 1532 primary stemmed MoM THAs, 1262 MoM hip resurfacings, and 219 stemmed MoM THAs implanted in revision surgery. RESULTS: Revision surgery was performed on 551 (36%) primary stemmed MoM THAs and on 179 (14%) resurfacings. The most common reason for revision was ARMD both among primary MoM THAs (83%) and hip resurfacings (70%). The 15-year implant survivorship was 69% (95% confidence interval [CI] 67-71%) for the whole study group, 56% (CI 53-60%) for stemmed primary MoM THAs, and 84% (CI 82-87%) for hip resurfacings. Clear temporal peak in the number of revisions for ARMD was seen in 2011-2013, and the trend has been decreasing since. CONCLUSION: After a decade since outburst of the ARMD problematics with MoM hips, a large proportion of them have gone through revision surgery at our single high-volume center. The peak years were 2011-2013, and thereafter, the number of ARMD revisions has decreased every year. With the threshold for revision remaining constant at our institution, it is not likely that large amount of new cases of ARMD will be seen. As these results are derived from a single center's data, similar studies from other institutions are needed to see whether our results represent a global trend.

Revision rate of reconstructions in surgically treated diaphyseal metastases of bone.

INTRODUCTION: Skeletal metastases can weaken the bone, necessitating surgery, and surgical treatment options vary. The aim of this study was to investigate the revision rate of reconstructions in surgically treated diaphyseal skeletal metastases. MATERIALS AND METHODS: Between 2000 and 2018 at Helsinki and Tampere university hospitals in Finland, a total of 164 cases with diaphyseal skeletal metastases were identified from a prospectively maintained database. Tumor location was humerus, femur, and tibia in 106 (65%), 53 (32%), and 5 (3.0%) cases, respectively. A total of 82 (50%) cases were treated with intramedullary nailing (IMN), 73 (45%) with IMN and cementation, and 9 (5%) with another technique. RESULTS: In the upper extremity, implant survival (IS) was 96.4% at 1, 2, and 5 years; in the lower extremity, it was 83.8%, 69.1%, and 57.6% at 1, 2, and 5 years, respectively. Lower extremity IS for impending lesions was 100% at 1, 2, and 5 years, and in cases operated for true pathologic fracture, it was 71.6%, 42.9%, and 21.5% at 1, 2, and 5 years, respectively. In IMN cases without cement, the complication rate was 16% (13/82) when compared to 6% (4/73) in IMN cases with cementation. DISCUSSION: We would advocate for early intervention in patients with metastatic bone disease affecting the femur rather that watchful waiting with the risk for fracture and the need for urgent intervention. However, this choice must be balanced against the underlying risk of surgical intervention in a potentially fragile population with often limited prognoses.

Total hip arthroplasty, combined with a reinforcement ring and posterior column plating for acetabular fractures in elderly patients: good outcome in 34 patients.

Background and purpose - Low-energy acetabulum fractures are uncommon, and mostly occur in elderly patients. Determining the optimal operative treatment for such fractures is challenging. Here we investigated whether acutely performed total hip arthroplasty plus posterior column plating (THA) reduced complications and reoperations compared with open reduction and internal fixation (ORIF) in elderly patients with acetabular fractures. Patients and methods - We retrospectively reviewed the records of 59 patients, > 55 years of age, with complex acetabular fractures, caused by low-energy trauma, treated between January 2008 and September 2017. Of these patients, 34 underwent acute THA, and 25 ORIF alone. Patient and implant survival were compared between groups using Kaplan-Meier survival analysis and Cox multiple regression. Functional outcomes assessed by Oxford Hip Score (OHS) were compared between the THA patients and those 9 ORIF patients who underwent secondary THA due to posttraumatic hip osteoarthritis (OA) during follow-up. Results - Overall patient survival was 90% (95% CI 82-98) at 12 months, and 64% (CI 47-81) at 5 years. Of 25 ORIF patients, 9 required secondary THA due to posttraumatic OA. Large fragments on the weight-bearing acetabular dome upon imaging predicted ORIF failure and secondary THA. The acute THA group and secondary THA group had similar 12-month OHS. Interpretation - Acute THA including a reinforcement ring resulted in fewer reoperations than ORIF alone in elderly patients with acetabular fractures. These findings support acute THA as first-line treatment for complex acetabular fractures in elderly patients.

Tibia Adamantinoma Resection and Reconstruction with a Custom-Made Total Tibia Endoprosthesis: A Case Report with 8-Year Follow-Up.

This case study describes a total tibia resection and reconstruction with a custom-made endoprosthetic replacement (EPR) and a long-term, 8-year follow-up. The patient underwent a total tibia adamantinoma resection in 2009. Reconstruction was performed with a custom-made total tibia EPR, where both the knee joint and ankle joint were reconstructed. Two muscle flaps, latissimus dorsi free flap and a pedicled medial gastrocnemius flap, were used for soft tissue reconstruction. The patient returned to normal life as a kindergarten teacher, without complications for eight years. This case demonstrated the importance of successful multidisciplinary teamwork in close collaboration with industry. In our best knowledge, no over 2 years of follow-up of total tibia replacement reports have been published.

Complications after surgical treatment of femoral neck fractures in men with alcohol dependence syndrome: retrospective register analysis of 154 cases.

PURPOSE: One-third of hip fractures occur in men. The causes underlying hip fractures in men differ from those in women and include alcohol abuse. This retrospective register study evaluated the trends and results associated with different surgical treatment methods for nondisplaced and displaced femoral neck fractures in male patients with alcohol dependence syndrome. METHODS: Men with hip fractures were identified from a local district hospital database. Alcohol dependence syndrome was identified as a diagnosis in medical records. RESULTS: For displaced fractures, implant survival after total hip arthroplasty was significantly lower compared to hemiarthroplasty. For nondisplaced fractures, implant survival of cannulated screws was significantly lower compared to sliding hip screws. Overall patient survival for males with alcohol dependence syndrome with hip fracture was 62% at 1 year and 49% at 2 years. Patient survival in this population did not differ between displaced and nondisplaced fractures or among different surgical methods. CONCLUSION: Patients with alcoholism who had documented evidence of alcohol dependence syndrome represented nearly half of patients <70 years old with low-energy hip fracture. In patients with nondisplaced femoral neck fractures, stability of the internal fixation appeared to play a major role in implant survival; sliding hip screws should be considered over multiple cannulated screws. In patients with displaced fracture, total hip arthroplasty was associated with a significantly higher risk of complications leading to revision compared to hemiarthoplasty. LEVEL OF EVIDENCE: Prognostic Level III.

High blood metal ion levels in 19 of 22 patients with metal-on-metal hinge knee replacements.

Background and purpose - There has been increasing alarm regarding metal-on-metal (MoM) joint replacements leading to elevated levels of metal ions and adverse reactions to metal debris (ARMDs). There is little information available concerning the prevalence of and risk factors for these adverse reactions, except with MoM hip joint replacements. We determined the levels of metal ions in blood and the rate of revision due to ARMDs in patients treated with MoM hinge total knee arthroplasty (TKA). Patients and methods - 22 patients with TKAs and MoM hinge connecting mechanisms were studied for whole-blood chromium and cobalt levels at 6 months, 1 year, and/or ≥2 years after surgery. Possible ARMDs were investigated by MRI. 12 patients with TKAs and metal-on-polyethylene (MoP) connecting mechanisms served as controls. Results - The cobalt levels were over 5 ppb in 19 of the 22 patients in the MoM group and in 1 of the 12 patients in the MoP group. The chromium levels were over 5 ppb in 11 of the 22 patients in the MoM group and in none of the 12 patients in the MoP group. Pseudotumors were operated in 4 of the 22 patients in the MoM group and in none of the patients in the MoP group. Interpretation - Our results clearly show that the MoM hinge TKA carries a high risk of increased levels of systemic metal ions and also local ARMD, leading to complicated knee revisions. We therefore discourage the use of MoM hinge TKA.

Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement.

BACKGROUND AND PURPOSE: There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors. PATIENTS AND METHODS: 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles. RESULTS: The prevalence of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that "preoperative diagnosis other than osteoarthrosis" was the strongest predictor of the presence of fatty atrophy. INTERPRETATION: Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

Genetic alterations in periprosthetic soft-tissue masses from patients with metal-on-metal hip replacement.

Adverse soft tissue reactions in patients with metal-on-metal (MoM) hip replacement are associated with cobalt (Co) and chromium (Cr) particles released from the implant. Exposing the patients to long periods of increased metal ions concentrations resulting from the wear of these implants poses an increased risk of genotoxicity/mutagenicity. A variable proportion of patients develop periprosthetic soft-tissue masses or pseudotumors at the site of the implant. There is a concern that exposure to increased metal ions could increase the risk of cancer. In order to investigate whether the periprosthetic soft-tissue mass harbours any cancer- related genetic alterations, we studied DNA isolated from periprosthetic tissues of 20 patients with MoM hip replacement, for copy number alterations and mutations in hotspot regions of 50 cancer genes using aCGH and amplicon-based next generation sequencing. Our results showed copy number gains at 12q14.3 and 21q21.1in tumour from patient diagnosed with liposarcoma. Copy number alterations in periprosthetic tissues were seen in three other patients, one had a region of gain at 9q24.1 affecting JAK2 and INSL6, and two patients had region of gain at 6p21.1, affecting RUNX2. Mutation analysis showed V1578del mutation in NOTCH1 in two patients. The copy number alterations and mutations seen in periprosthetic soft-tissue masses are earlier reported in either haematological malignancies or in osteoblast related bone dysplasia. The presence of genetic anomalies was associated with longer in-situ time of the implant. Our findings warrant the need of similar studies in larger patient cohorts to evaluate the risk of development of neoplastic alterations in periprosthetic tissues of patients with MoM hip replacement.

Repeated magnetic resonance imaging in 154 hips with large-diameter metal-on-metal hip replacement.

BACKGROUND AND PURPOSE: The US Food and Drug Administration and the UK Medicines and Health Regulation Agency recommend using MRI in the evaluation of patients with large-diameter metal-on-metal (LD-MoM) hips. Such recommendations do not take into account the relevance of repeated cross-sectional imaging. We therefore investigated the natural course of pseudotumors in patients with LD-MoM hip replacements. PATIENTS AND METHODS: Of 888 ASR patients (1,036 hips) 674 patients (798 hips) underwent 2 follow-up visits at our institution. Of these, we identified 124 patients (154 hips) who had undergone repeated clinical assessment including MRI and whole-blood metal ion assessment. RESULTS: A change in classification in imaging findings between the 2 MRIs was seen in 17 of the 154 hips (11%). In 13 hips (8%), a significant progression of the pseudotumor was evident, while in 4 (3 %) there was a retrogressive change. 10 of these 13 hips had had a normal first MRI. Patients with a progressive change in the scans did not differ significantly from those without a change in MRI classification regarding follow-up time, time interval between MRIs, or changes in whole-blood Cr and Co levels between assessments. INTERPRETATION: A change in classification was rare, considering that all patients had a clinical indication for repeated imaging. Progression of the findings did not appear to correlate clearly with symptoms or whole-blood metal values.

An unusual case of clear cell chondrosarcoma with very late recurrence and lung metastases, 29 years after primary surgery.

Clear cell chondrosarcoma is a rare bone neoplasm with low-grade clinical course and the potential to metastasize to the skeleton and lungs. The aim of this report is to present a case that is extremely rare, but in accordance with the literature where the clear cell chondrosarcoma reportedly has a tendency for late metastases. In our patient the primary surgery was intralesional, since it was mistakenly interpreted as a benign tumour in the early 80s. The local recurrence and lung metastases occurred, however, 29 years after the initial treatment. The local recurrence was resected with wide margins, no additional surgery or oncological treatments were given, and two and half years postoperatively patient is doing well and there is no progression in the disease. In conclusion, it is important to have a long follow-up to the clear cell chondrosarcoma patients even for decades or lifelong, because the malignancy tends to metastasize or recur after an extended period. The course of metastasized disease may be unusually slow, so relatively aggressive treatment in metastasized and recurring cases is justified.

Predictors of mortality following primary hip and knee replacement in the aged. A single-center analysis of 1,998 primary hip and knee replacements for primary osteoarthritis.

BACKGROUND AND PURPOSE: High age is associated with increased postoperative mortality, but the factors that predict mortality in older hip and knee replacement recipients are not known. METHODS: Preoperative clinical and operative data on 1,998 primary total hip and knee replacements performed for osteoarthritis in patients aged ≥ 75 years in a single institution were collected from a joint replacement database and compared with mortality data. Average follow-up was 4.2 (2.2-7.6) years for the patients who survived. Factors associated with mortality were analyzed using Cox regression analysis, with adjustment for age, sex, operated joint, laterality, and anesthesiological risk score. RESULTS: Mortality was 0.15% at 30 days, 0.35% at 90 days, 1.60% at 1 year, 7.6% at 3 years, and 16% at 5 years, and was similar following hip and knee replacement. Higher age, male sex, American Society of Anesthesiologists risk score of > 2, use of walking aids, preoperative walking restriction (inability to walk or ability to walk indoors only, compared to ability to walk > 1 km), poor clinical condition preoperatively (based on clinical hip and knee scores or clinical severity of osteoarthritis), preoperative anemia, severe renal insufficiency, and use of blood transfusions were associated with higher mortality. High body mass index had a protective effect in patients after hip replacement. INTERPRETATION: Postoperative mortality is low in healthy old joint replacement recipients. Comorbidities and functional limitations preoperatively are associated with higher mortality and warrant careful consideration before proceeding with joint replacement surgery.

Treatment of pathological humerus shaft fractures with intramedullary nails with or without cement fixation.

INTRODUCTION: Bone metastasis is a severe complication for patients with cancer. Not only does it cause intractable pain and other clinical problems such as fracture after trivial injury, it also signifies that the malignant process is incurable. Since life expectancy of metastasised cancer patients has improved due to advanced oncological treatment but is still limited, appropriate surgical intervention has increased. METHOD: This is a retrospective control study of 21 patients who underwent cemented intramedullary nailing for pathological fractures in the humeral shaft between 2005 and 2009 as compared to a historical control group of 19 patients that underwent locked intramedullary nailing for pathological fractures in the humeral shaft between 1999 and 2004. Four major outcomes were assessed, namely, pain relief, use of analgesics, recovery of function and rate of complication. RESULTS: Patients treated with cemented intramedullary nailing had better pain relief, less use of analgesics and better functional restoration immediately after surgical procedure when compared to the patients without cement fixing. The rate of complication did not differ between these two groups. CONCLUSION: Since surgery for metastases does not prolong life but improves the quality of life, the aim towards a short postoperative rehabilitation time is recommended. Cement fixation gives immediate stabilisation to the fracture site and thus allows less pain but full range of motion from the first postoperative day.

Disturbed synthesis of type II collagen interferes with rate of bone formation and growth and increases bone resorption in transgenic mice.

Transgenic mice carrying an internally deleted human type II collagen gene (COL2A1) were used to study bone growth and development. This mutation has previously been shown to disturb the development of collagen fibrils in articular cartilage, causing chondrodysplasia and osteoarthritis. Type II collagen expression in bones was investigated with immunohistochemistry. The development and mineralization of the skeleton and anthropometric measurements on bones were evaluated using X-rays and dynamic histomorphometry. Type II collagen was expressed in the cartilage of developing bones. The bones of transgenic mice were smaller compared with the controls. The bone mass remained almost unchanged in transgenic mice after 1 month of age, leading to differences of 47% in trabecular bone volume (P = 0.012) and 40% in trabecular thickness (P < 0.01) at the age of 3 months compared with controls. At the age of 3 months the eroded surface per bone volume was 31% greater in transgenic mice compared with controls (P < 0.05). Trabecular thickness correlated positively with body weight (R = 0.71, P < 0.001). Interestingly, body weight correlated with bone volume in control mice (R = 0.27, P < 0.01), but no correlation was observed in transgenic mice. The disturbed synthesis of cartilage-specific type II collagen in growing transgenic mice retarded bone development, increased bone resorption, and altered tissue properties. This led to a negative net bone balance and small bone size. The results support the idea that an altered synthesis of cartilage-specific molecule(s) can disturb postnatal bone development and growth.