Miguel Ayerza

Intercalary femur and tibia segmental allografts provide an acceptable alternative in reconstructing tumor resections.

Intercalary femur and tibia segmental allografts were implanted in 59 consecutive patients after segmental resection—52 for malignant and seven for benign aggressive bone tumors. The patients were followed up for an average of 5 years. Allograft survival was determined with the Kaplan–Meier method. Infection, fracture, and nonunion rates were determined. The overall 5-year survivorship for the 59 intercalary allografts was 79%, and we found no significant differences between allograft survival in patients receiving or not receiving adjuvant chemotherapy. Infection and fracture rates were 5% and 7% respectively. From 118 host-donor junctions, 11 did not initially heal (9%). The nonunion rate (10 of 69 osteotomies) for diaphyseal junctions was higher than the rate (one of 49 osteotomies) for metaphyseal junctions. Although some patients required reoperations because of allograft complications, it seems that the use of intercalary allograft clearly has a place in the reconstruction of a segmental defect created by the resection of a tumor in the diaphyseal and /or metaphyseal portion of the femur or tibia.

Use of Distal Femoral Osteoarticular Allografts in Limb Salvage Surgery

BACKGROUND As diagnostic and therapeutic techniques improve, patients with a musculoskeletal sarcoma should expect longer survival, fewer complications and side effects, and an improved quality of life. Functional longevity of the reconstruction after resection of the tumor becomes a major concern, especially in young and physically active patients. The purpose of this study was to analyze the mid-term and long-term survival of reconstructions with a distal femoral osteoarticular allograft in a series of patients. METHODS We retrospectively reviewed the results of eighty reconstructions with a distal femoral osteoarticular allograft following resection of a bone tumor in seventy-six patients. The mean duration of follow-up was eighty-two months. The rates of survival of the allograft and the joint surface were estimated with use of the Kaplan-Meier method. Cox regression analysis was performed to determine whether age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were independent prognostic factors. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up. RESULTS Five patients were lost to follow-up, leaving seventy-five allografts in seventy-one patients available for study. Thirteen patients (thirteen allografts) died of tumor-related causes without allograft failure before a two-year radiographic follow-up could be performed. Of the remaining sixty-two allografts, fourteen failed: six failed as a result of infection; four, because of local recurrence; one, because of massive resorption; and three, as a result of fracture. At the time of final follow-up, at a mean of 125 months, forty-eight allografts were still in place. The overall rate of allograft survival was 78% at both five and ten years, and the rate of allograft survival without the need for resurfacing with a knee prosthesis was 71% at both five and ten years. With the numbers available, age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were not found to have a significant effect on the overall allograft survival rates. The patients who retained the original allograft had good or excellent functional and radiographic results. CONCLUSIONS The life expectancy for most patients with a highly aggressive or malignant tumor in the distal part of the femur is now several decades. In this study, we found a high rate of survival of distal femoral allograft reconstructions at both five and ten years.

Osteonecrosis of the knee following arthroscopic meniscectomy in patients over 50-years old

We reviewed eight patients over 50-years old, with an initial diagnosis of medial meniscal tear confirmed with magnetic resonance imaging (MRI) and with no evidence of osteonecrosis. After arthroscopic meniscectomy, all patients had recurrent aggravated knee pain and reevaluation with MRI showed images compatible with osteonecrosis. The average age was 65 years (range 54 to 75 years). The mean time from MRI to surgery was 8 weeks (range 1 to 28 weeks). In five patients a total meniscectomy, and in three a partial meniscectomy with recontouring of the meniscus were performed. Surgical treatment was initially successful, but all eight patients returned to our office with recurrent aggravated pain in the treated knee. Reevaluation with MRI, at an average of 18 weeks postoperatively, found abnormalities at the medial condyle consistent with osteonecrosis. The purpose of this study is to report a potentially serious outcome after arthroscopic meniscectomy in patients over 50-years old.

Partial Epiphyseal Preservation and Intercalary Allograft Reconstruction in High-Grade Metaphyseal Osteosarcoma of the Knee

BACKGROUND The purpose of this study was to analyze a series of patients with a high-grade metaphyseal osteosarcoma of the knee who had been treated with a transepiphyseal resection, with preservation of the distal femoral and the proximal tibial (articular) portions of the epiphysis, and an intercalary allograft reconstruction. METHODS The cases of thirteen patients with a high-grade metaphyseal osteosarcoma around the knee who had transepiphyseal resection and reconstruction with an intercalary allograft were retrospectively reviewed at a mean of sixty-three months. Complications, disease-free survival of the patient, final preservation of the limb and epiphysis, and functional results according to the Musculoskeletal Tumor Society scoring system were documented at the time of the latest follow-up. RESULTS At the final follow-up examination, eleven of the thirteen patients continued to be disease-free. One patient died of bone and pulmonary metastases with no evidence of local recurrence, and the remaining patient had no evidence of disease after resection of a local recurrence of the tumor in the soft tissues. No patient had a local recurrence in the remaining epiphysis. Seven patients had complications that included a fracture (three patients), diaphyseal nonunion (two), deep infection (one), and a local recurrence in the soft tissues (one). The allograft was removed in only four of these patients. At the latest follow-up examination, twelve patients were alive with preserved limbs. In one patient, the epiphysis, which originally had been preserved, was resected because of a metaphyseal fracture, and the limb was reconstructed with an osteoarticular allograft. The patients with a preserved epiphysis had an average functional score of 27 points (maximum, 30 points). CONCLUSIONS Preservation of the epiphysis in high-grade metaphyseal osteosarcoma at the knee is an alternative in carefully selected patients. Crucial factors needed to obtain local tumor control and achieve an acceptable functional result are a positive response to chemotherapy, accurate preoperative assessment of tumor extension to the epiphysis, and appropriate fixation techniques for intercalary allografts. LEVEL OF EVIDENCE Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Arthroscopic Fixation of Osteochondritis Dissecans of the Knee Clinical, Magnetic Resonance Imaging, and Arthroscopic Follow-up

Background Optimal treatment of osteochondritis dissecans of the knee is still controversial. Purpose To review a group of patients with osteochondritis dissecans of the knee who were treated with arthroscopic compressive screw fixation and who were evaluated with magnetic resonance imaging studies and a second-look arthroscopic procedure at follow-up. Study Design Case series; level of evidence, 4. Methods A total of 14 patients (15 knees) with osteochondritis dissecans of the knee were treated with arthroscopic titanium Herbert screw fixation of the osteochondral fragment. A second-look arthroscopic procedure was performed to remove hardware and to evaluate fragment stability. At final follow-up, magnetic resonance imaging studies were used to evaluate potential healing of the subchondral bone. Outcomes were clinically evaluated at a mean follow-up of 50 months (range, 25-104 months) by the Lysholm score and by the International Knee Documentation Committee score. Results At second-look arthroscopy, 14 of 15 knees showed evidence of a stable fragment with an intact smooth surface. According to magnetic resonance imaging parameters, 14 knees showed evidence of a healing process of the osteochondral fragment. The average Lysholm score improved 18 points from a mean of 79 preoperatively to 97 postoperatively, and according to the International Knee Documentation Committee score, 13 of 15 knees showed a normal result. Conclusion This study suggests that magnetic resonance imaging parameters of a healed osteochondral fragment and patients with satisfactory functional results correspond with arthroscopic evidence of fragment stability. According to this study, arthroscopic fixation with compressive screws is an effective method of repair for osteochondritis dissecans of the knee.

Survivorship and radiographic analysis of knee osteoarticular allografts.

An evaluation of long-term survival and radiographic deterioration of 118 knee osteoarticular allografts in 114 patients was performed. Radiographic analysis was done according to the Musculoskeletal Tumor Society grading system. A failure was defined as when the allograft was removed during a revision procedure or amputation. Ten patients were lost to followup during the first 2 years after surgery. Eighteen patients without allograft failures died of complications related to the tumor. Twenty-six allografts failed because of infection (13 allografts), local recurrence (eight allografts), massive resorptions (three allografts) and fractures (two allografts). Sixty-four allografts still were in place at a mean of 98 months (range, 36-360 months) after implantation. The Kaplan-Meier 5-year survival rate for the knee osteoarticular allografts was 73% and the limb preservation rate was 93%. The mean radiographic score was 83%. Sixty-four percent of the allografts showed no radiologic changes or minor articular deterioration. Fourteen percent had narrowing of the joint space of more than 2 mm, and 22% had some form of subchondral bone collapse. Five patients required joint resurfacing to preserve the original allograft. Most of the allograft failures occurred during the first 4 years, and the allograft survival rate for the current series remained unchanged after 5 years.

The use of a bone allograft for reconstruction after resection of giant-cell tumor close to the knee.

The results of bone-allograft reconstruction after the resection of giant-cell tumor close to the knee were reviewed in fifty-two patients (fifty-five allografts), who had been followed for a mean of seven years (range, two to twenty-four years). One giant-cell tumor was graded as stage 1; twenty, as stage 2; and thirty-one, as stage 3. Three reconstructions were repeated transplants that were done after the failure of a previous transplant. Ten allograft reconstructions were intercalary and were combined with an arthrodesis of the knee, and forty-five were osteoarticular. Major complications included infection (after three reconstructions), resorption of the graft (six), collapse of the articular surface (two), fracture (two), and recurrence (one). According to the criteria described by Mankin et al. for functional analysis, forty-two (76 per cent) of the extremities had a result that was considered to be excellent or good. Radiographic evaluation according to the system of the Musculoskeletal Tumor Society showed a mean score of 72 per cent for osteoarticular reconstructions, and of 86 per cent for intercalary reconstructions.

Tumors About the Knee Misdiagnosed as Athletic Injuries

Background: Musculoskeletal tumors may originally mimic a traumatic condition, and, on the basis of an erroneous diagnosis of an athletic injury, an invasive diagnostic or therapeutic procedure may be performed. We determined the number of such cases treated at our institution, and we analyzed the initial and final diagnoses as well as the changes in the indicated oncologic surgical technique due to the initial erroneous diagnosis. Methods: Twenty-five patients who had a bone or soft-tissue tumor about the knee that originally had been diagnosed as an athletic injury were referred to our institution. The complete clinical, radiographic, and pathological records were reviewed. Studies that had been performed prior to the invasive procedure and at the time of admission to our institution were evaluated to determine differences in the tumor stage and the oncologic treatment that was indicated at each time. Results: Of 667 knee tumors diagnosed in our institution, twenty-five (3.7%) previously had been treated with an intra-articular procedure as a result of a misdiagnosis of an athletic injury. The final diagnoses made at our institution were a benign tumor in eleven patients and a malignant tumor in fourteen. Oncologic surgical treatment was affected in fifteen of the twenty-five patients. Conclusions: When a knee tumor is initially misdiagnosed as an athletic injury, treatment may be adversely affected by the delay in diagnosis or an inappropriate invasive procedure that results in extension of the tumor. Initial poor-quality radiographs and an unquestioned original diagnosis despite persistent symptoms were the most frequent causes of an erroneous diagnosis. Level of Evidence: Prognostic study, Level IV (case series). See Instructions to Authors for a complete description of levels of evidence.

Localized pigmented villonodular synovitis of the posterior compartment of the knee: Diagnosis with magnetic resonance imaging

Localized Pigmented Villonodular Synovitis (LPVS) is a lesion that may affect any joint but is frequently found in the knee. Detection and diagnosis of this entity are clinically difficult, and plain roentgenograms are usually within normal limits. We present a case report of a LPVS localized at the posterior compartment of the knee that mimics a meniscal lesion. Magnetic resonance imaging (MRI) performed before the resection through an arthroscopic procedure helped to diagnose the tumor, which in this case had an infrequent location. MRI is a valuable clinical tool for the assessment of intraarticular tumors of the knee joint that otherwise may be misdiagnosed and treated as a meniscal tear.

Accuracy of 3-D planning and navigation in bone tumor resection.

Surgical precision in oncologic surgery is essential to achieve adequate margins in bone tumor resections. Three-dimensional preoperative planning and bone tumor resection by navigation have been introduced to orthopedic oncology in recent years. However, the accuracy of preoperative planning and navigation is unclear. The purpose of this study was to evaluate the accuracy of preoperative planning and the navigation system. A total of 28 patients were evaluated between May 2010 and February 2011. Tumor locations were the femur (n=17), pelvis (n=6), sacrum (n=2), tibia (n=2), and humerus (n=1). All resections were planned in a virtual scenario using computed tomography and magnetic resonance imaging fusion. A total of 61 planes or osteotomies were performed to resect the tumors. Postoperatively, computed tomography scans were obtained for all surgical specimens, and the specimens were 3-dimensionally reconstructed from the scans. Differences were determined by finding the distances between the osteotomies virtually programmed and those performed. The global mean of the quantitative comparisons between the osteotomies programmed and those obtained through the resected specimen was 2.52±2.32 mm for all patients. Differences between osteotomies virtually programmed and those achieved by navigation intraoperatively were minimal.