Are fibula strut allografts a reliable alternative for periarticular reconstruction after curettage for bone tumors?

A new joint reconstruction technique in the treatment of giant cell tumors around the knee: Structural allograft and unicompartmental arthroplasty

OBJECTIVE

The long-term prognosis of patients who underwent unicompartmental knee arthroplasty (UKA) with a structural allograft or hemiarticular allograft transplantation to treat giant cell tumors (GCTs) around the knee and the prosthesis survival rate were analyzed.

METHODS

We retrospectively reviewed 73 patients who were diagnosed with GCTs around the knee and underwent surgery to restore joint function from 2000 to 2015. Patients were divided into two groups according to the surgical procedure used for functional knee reconstruction: hemiarticular allograft transplantation or structural allograft and UKA. The Knee Society Score (KSS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used to analyze postoperative knee function between the two groups. The Kellgren-Lawrence (K-L) classification system was used to evaluate the progression of osteoarthritis. The incidence of complications and the prosthesis survival rate were also investigated.

RESULTS

Patients who underwent UKA to treat GCT demonstrated significantly improved knee function. The rate of an excellent or good KSS was significantly different between the two groups (p = 0.041 at the 1-year follow-up, p = 0.033 at the last follow-up). The proportion of severe cases according to WOMAC in the two groups was also different (p = 0.030 at the 1-year follow-up, p = 0.021 at the last follow-up). According to the K-L grade of unaffected compartments, UKA better prevented the progression of osteoarthritis (p = 0.034).

CONCLUSIONS

Patients with GCTs around the knee could benefit from UKA. In addition to providing better knee function and range of motion, UKA could also slow the progression of osteoarthritis in the knee joint. This new surgical method could meet the needs of patients wishing to preserve joint integrity and favorable joint function.

Giant Cell Tumor of Talus: T-Construct Method of Bone Grafting

Giant cell tumor (GCT) or osteoclastoma is a benign, locally aggressive tumor with a tendency to recur. Giant cell tumors typically occur in the epiphysis of long bones, including the distal femur and proximal tibia. They are uncommonly found in the small bones of the foot or ankle, and involvement of talus is rare. The authors present a case of GCT of the talar body in a 21-year-old man, which was diagnosed radiologically by the presence of a well-defined osteolytic lesion involving more than half of the talar body with thinning of the cortices. An intralesional curettage and chemical cauterization with phenol was done using a medial approach following an osteotomy of the medial malleolus for adequate exposure. Intraoperative frozen section of curetted tissue was sent and was reported as benign GCT. The residual cavity was packed with autologous corticocancellous bone grafts fashioned in a T-construct like manner. A protective cast was applied for a period of 2 months and patient was subsequently gradually mobilized to full weightbearing status. At 2-year follow-up, there was no clinical or radiologically evident signs of recurrence. There was good consolidation of the bone graft in the talus with no signs of collapse of the weightbearing articular surface.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case Study.

Use of a fibular strut allograft in an osteoporotic distal humerus fracture: a case report

In 2004, nearly 120 000 fragility fractures of the humerus were reported. As the US population ages, this number is expected to increase. Fractures of the distal humerus can be treated in a closed or open fashion. Open treatment includes open reduction and internal fixation or total elbow arthroplasty. Open reduction and internal fixation typically involves dual plating for increased stability and early mobility. We present a case in which dual plating failed due to lack of screw purchase in osteoporotic bone. This patient's fracture was then revised with the use of a fibular strut allograft for improved stability and screw purchase. This method of fixation has not previously been described in the distal humerus and may prove useful in open fixation of osteoporotic distal humerus fractures.

Repeated freeze-thaw cycles do not alter the biomechanical properties of fibular allograft bone

BACKGROUND

Allograft tissues can undergo several freeze-thaw cycles between donor tissue recovery and final use by surgeons. However, there are currently no standards indicating the number of reasonable freeze-thaw cycles for allograft bone and it is unclear how much a graft may be degraded with multiple cycles.

QUESTIONS/PURPOSES

We therefore asked whether (1) the mechanical properties of fibular allograft bone would remain unchanged with increasing numbers of freeze-thaw cycles and (2) histologic alterations from increased numbers of freeze-thaw cycles would correspond to any mechanical changes.

METHODS

Fibular allograft segments were subjected to two, four, and eight freeze-thaw cycles and compared biomechanically and histologically with a control group (one freeze-thaw cycle). Two freeze-dried treatments, one after being subjected to one freeze-thaw cycle and the other after being subjected to three freeze-thaw cycles, also were compared with the control group.

RESULTS

For all segments, the average ultimate stress was 174 MPa, average modulus was 289 MPa, average energy was 2.00 J, and the average stiffness was 1320 N/mm. The material properties of the freeze-thaw treatment groups were similar to those of the control group: ultimate stress and modulus were a maximum of 16% and 70% different, respectively. Both freeze-dried treatments showed increased stiffness (maximum 53% ± 71%) and energy to failure (maximum 117% ± 137%) but did not exhibit morphologic differences. There were no alterations in the histologic appearance of the bone sections in any group.

CONCLUSIONS

Fibular allograft segments can be refrozen safely up to eight times without affecting the biomechanical or morphologic properties. Freeze-dried treatments require further study to determine whether the detected differences are caused by the processing.

CLINICAL RELEVANCE

Cryopreserved cortical allografts are thawed by surgeons in preparation for procedures and then occasionally discarded when not used. Refreezing allograft tissues can result in a cost savings because of a reduction in wasted graft material.

A eletrocauterização isolada como adjuvante no tratamento dos tumores ósseos benignos

OBJETIVOS: Avaliar o papel da eletrocauterização como método adjuvante isolado na ressecção intralesional dos tumores ósseos benignos, levando em conta fatores associados à recorrência dessas lesões. MÉTODOS: Foram incluídos 47 pacientes com diagnóstico de tumores ósseos benignos que foram tratados com curetagem associada a eletrocauterização como método adjuvante. Os pacientes foram acompanhados por um tempo médio de 32,7± 19,4 meses e foi avaliada a taxa de recidiva em relação às seguintes variáveis: idade, sexo, localização do tumor, tipo histológico, estadiamento (B1, B2, B3), tamanho, tipo de material utilizado como preenchimento (PMMA ou enxerto ósseo). A taxa e o tipo de complicação pós-operatória também foram analisadas. RESULTADOS: A recidiva global foi de 19,1%, havendo correlação significante do grau do tumor em relação ao tempo de recidiva (p=0,028). Não foram observados outros fatores diretamente relacionados à recidiva local. CONCLUSÃO: A eletrocauterização mostrou-se um método simples, barato e eficaz no tratamento adjuvante dos tumores ósseos benignos. Nivel de Evidência IV, serie de casos.

Managing bone deficiency and nonunions of the proximal femur

Revision surgery of the proximal femur with bone loss secondary to failed cephalomedullary nails is problematic and becoming more prevalent as their use grows. This article presents a technique of deformity correction, bone graft techniques that reconstitute residual defects, and definitive fixation using load-sharing devices that provide immediate stability for bone healing and early rehabilitation. Preoperative planning and the potential advantages and disadvantages of newer fixed-angled plates versus established implants are discussed. With proper planning, surgical execution with proved techniques, augmented by the addition of newer graft harvesting techniques, anatomic restoration, and bone reconstitution with healing, has invariably been the result.

Joint preservation after extensive curettage of knee giant cell tumors

Curettage is the most attractive procedure for surgically treating a giant cell tumor because it preserves joint function. However, since many giant cell tumors compromise subchondral bone this technique can jeopardize the articular surface with subsequent fractures or collapse. We asked whether intralesional curettage of a giant cell tumor close to the knee that combined morselized bone and cortical structural allograft would preserve joint function. We retrospectively reviewed 22 patients treated with that approach. The minimum followup was 2 years (average, 48 months; range, 24-80 months). The distal femur was involved in 12 patients and proximal tibia in 10. Complications and failures were recorded and functional results evaluated with Musculoskeletal Tumor Society score. We determined survivorship using the Kaplan-Meier technique using removal of the implant as the endpoint. The survival was 85% and the average functional score 28 points. Three of the 22 patients had a local tumor recurrence and one had a partial subchondral collapse not requiring further treatment. Among the remaining patients, none had fracture, infection, or knee instability. The combination of fragmented and cortical allograft allows reconstructing the bone defect and ligaments created after extensive curettage of a knee giant cell tumor obtaining normal joint function and a high survival rate with minimal complications in a high percentage of the patients.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Distal femur defects reconstructed with polymethylmethacrylate and internal fixation devices: a biomechanical study

Benign aggressive distal femur tumors are treated with curettage, adjuvant phenol or argon, and polymethylmethacrylate (PMMA) packing. For large defects, an internal fixation device is added to reduce the fracture risk. The purpose of this study is to compare the strength of locking plates to other fixation devices for stabilization of these defects. Lateral condyle defects in young, fresh frozen femurs were packed with PMMA and augmented by internal fixation. Three groups of 4 matched pairs of femurs were organized for the following comparisons: (1) stacked Steinmann pins vs crossed screws; (2) stacked pins vs locking plates; and (3) crossed screws vs locking plates. Specimens were subjected to axial load-to-failure testing on an MTS machine. There was no difference in load-to-failure strength (P=.177) using Steinmann pins or crossed screws. Locking plate constructs were stronger (P=.028) than Steinmann pin constructs. Locking plate constructs were also stronger (P<.001) than crossed-screw constructs. Steinmann pin constructs failed with severe intra-articular fractures; crossed screw constructs failed with bulging of the defects, articular impaction, and minimal fracture propagation. Locking plate constructs failed with extra-articular spiral shaft fractures.

Distal tibial giant cell tumour treated with curettage and stabilisation with an Ilizarov frame

A 36-year-old man presented with a long history of pain in his left ankle. Imaging and biopsy confirmed this to be a giant cell tumour of bone. This was treated with curettage of the lesion and stabilisation with an Ilizarov frame. After a prolonged course of rehabilitation he has excellent function and has returned to hill walking and there is no evidence of recurrence of the giant cell tumour.