Osteoarticular Reconstruction Research Articles

Biological reconstruction of bone defect after resection of malignant bone tumor by allograft: a single-center retrospective cohort study

BackgroundAllograft reconstruction following the resection of malignant bone tumors is associated with high rates of complications and failures. This study aimed to evaluate the efficacy and current problems of allograft reconstruction techniques to optimize treatment strategies at our center.Materials and methodsThirty-eight cases (16 men and 22 women), who were diagnosed with malignant bone tumors and had undergone allograft reconstruction, were recruited. Allograft was fixed by intramedullary nail, single steel plate, double plate, and intramedullary nail combined plate in 2, 4, 17, and 15 cases, respectively. Allograft union, local recurrence, and complications were assessed with clinical and radiological tests. Tumor grade was assessed using the Enneking staging of malignant bone tumors. Functional prognosis was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system.ResultsIntercalary and osteoarticular reconstructions were performed in 32 and 6 cases, respectively. Six patients underwent reoperation related to allograft complications, four patients had local recurrence, and three patients with allograft fracture underwent allograft removal. A total of eight host–donor junctions showed nonunion, including seven cases (18.4%) in diaphysis and one case (3.1%) in metaphysis (p < 0.01). Host rejection and secondary osteoarthritis occurred in nine and two cases, respectively. No deep infection and internal fixation device fracture occurred. The overall allograft survival rate was 81.6%. Postoperative MSTS score of patients with allograft survival was 26.8 ± 2.9, indicating a significant improvement as compared to their preoperative function.ConclusionsAllograft represents an excellent choice for intercalary bone defects after malignant bone tumor resection. Robust internal fixation protection across the whole length of the allograft is an important prerequisite for the survival of the allograft, while multidimensional osteotomy, intramedullary cement reinforcement, and pedicled muscle flap transfer can effectively improve the survival rate and healing rate of the allograft.

A comparison of osteoarticular allografts and allograft-prosthesis composites for reconstruction of the distal femur after resection of a bone tumour in childhood : a retrospective study.

Osteoarticular reconstruction of the distal femur in childhood has the advantage of preserving the tibial physis. However, due to the small size of the distal femur, matching the host bone with an osteoarticular allograft is challenging. In this study, we compared the outcomes and complications of a resurfaced allograft-prosthesis composite (rAPC) with those of an osteoarticular allograft to reconstruct the distal femur in children. A retrospective analysis of 33 skeletally immature children with a malignant tumour of the distal femur, who underwent resection and reconstruction with a rAPC (n = 15) or osteoarticular allograft (n = 18), was conducted. The median age of the patients was ten years (interquartile range (IQR) 9 to 11) in the osteoarticular allograft group and nine years (IQR 8 to 10) in the rAPC group (p = 0.781). The median follow-up of the patients was seven years (IQR 4 to 8) in the osteoarticular allograft group and six years (IQR 3 to 7) in the rAPC group (p = 0.483). Limb function was evaluated using the Musculoskeletal Tumor Society (MSTS) score. At final follow-up, the knee was unstable in 9/18 patients (50%) in the osteoarticular allograft group and 2/15 patients (13%) in the rAPC group (p = 0.026). The median range of motion (ROM) of the knee was 117° (IQR 115° to 120°) in the osteoarticular allograft group and 100° (IQR 95° to 105°) in the rAPC group (p < 0.001). The median MSTS score was 25 (IQR 23 to 26) in the osteoarticular allograft group and 28 (IQR 26 to 29) in the rAPC group (p = 0.007). Osteoarthritic change was detected in 11/18 patients (61%) in the osteoarticular allograft group and in 4/15 (26%) patients in the rAPC group (p = 0.048). In our series, a resurfaced allograft-prosthesis composite provided better knee stability and function, with a lower rate of osteoarthritis; an osteoarticular allograft was associated with better knee ROM.Cite this article: Bone Joint J2022;104-B(10):1174-1179.

Definition of post-traumatic outcomes of operated and unoperated knee fractures

Knee fractures include fractures of the tibial plateau, distal femur, and patella. The most frequent complication of these fractures is post-traumatic osteoarthritis, defined as secondary osteoarthritis that develops as a result of direct damage or trauma to a specific joint. According to the available data, 23-36% of people who have suffered an intra-articular knee fracture will develop secondary osteoarthritis. The average age at which it develops is 9-14 years before the average age at which primary osteoarthritis develops in the general population. Analysis of the literature shows that treatment of knee fractures must be chosen according to various parameters such as age, state of health, and degree of activity of the patient as well as the extent of damage to the joint surface. In young patients, there is an indication for open reduction and internal fixation treatments, corrective osteotomies, or osteoarticular reconstruction, while in elderly patients with low functional demands the use of total knee prostheses should be considered. It must be taken into account, however, that poor functional results of prostheses are reported when used in cases of high complexity of joint deformity, especially if they involve both the femur and tibia and in case of compromised soft tissues that require reconstruction.

Do irradiated osteo-articular recycled tumor autografts still hold promise for biological joint reconstruction? Our experience with acetabular and proximal ulna ECRT

BackgroundJoint reconstruction following resection of malignant bone tumors is challenging in itself in spite of several options in hand. Ability to restore joint anatomy, function and mobility while achieving optimal oncological outcomes are the requirement of reconstructions today. While biological reconstructions (allograft or recycled tumor autografts) following tumor bone surgery are popular for intercalary resections not involving the joint, their use for osteo-articular reconstructions are associated with concerns over cartilage and joint health. We have used extracorporeal radiation therapy (ECRT) and re-implantation of the osteoarticular segment as a size matched recycled tumor autograft reconstruction after complex acetabular and proximal ulnar resections; owing to the lack of significantly superior reconstruction alternatives in these locations and also review the current literature on other biological/non-biological reconstruction options. Questions/purposes(1) What are the oncological, reconstruction and functional outcomes with osteo-articular reconstruction using ECRT and re-implantation of recycled tumor autograft for the acetabulum and olecranon? (2) Is there an evidence of cartilage loss, joint damage or avascular necrosis resulting from irradiation of the articular autograft? Methods19 patients with primary bone tumors underwent limb salvage surgery with en-bloc resection and reconstruction using the resected articular tumor bone after treating it with extra-corporeal irradiation of 50–60Gy. These included 16 acetabular and 3 proximal ulnar. While all patients were included for oncological assessment; minimum follow-up of 24 months was considered for final outcome assessment of function and joint status. ResultsMSTS scores of the 16 acetabular reconstruction patients with minimum 2 years follow-up was 87% (26/30). Neither delayed union, non-union at osteotomy sites nor was any fractures reported in the irradiated graft. There was no local recurrence within the irradiated graft and only 1 patient required graft excision for uncontrolled infection. All 3 patients of proximal ulna reconstruction achieved healing and full range of movement of the elbow. Scores of MSTS: 100% (30/30), MEPS: 100 and DASH: zero was achieved. Two patients developed osteonecrosis of the femoral head; one requiring a joint replacement and one awaiting replacement. One patient of acetabular reconstruction has joint space narrowing on radiographs with mild clinical symptoms. ConclusionsExtracorporeal radiotherapy and re-implantation after osteo-articular resection is an oncologically safe option offering promising outcome in our small series. The availability of size-matched graft, thus avoiding inherent problems of allograft also provides a better economic option over endoprosthesis and its associated complications in select sites. The results can deteriorate over time that may require secondary reconstructive procedures like joint replacement. Level of evidenceLevel IV, Therapeutic Study.

Different reconstructive techniques for tumours of the distal tibia.

The aim of this study was to report the results of three forms of reconstruction for patients with a ditsl tibial bone tumour: an intercalary resection and reconstruction, an osteoarticular reconstruction, and arthrodesis of the ankle. A total of 73 patients with a median age of 19 years (interquartile range (IQR) 14 to 36) were included in this retrospective, multicentre study. Reconstructions included intercalary resection in 17 patients, osteoarticular reconstruction in 11, and ankle arthrodesis in 45. The median follow-up was 77 months (IQR 35 to 130). Local recurrence occurred in eight patients after a median of 14 months (IQR 9 to 36), without a correlation with adequacy of margins or reconstructive technique. Major complications included fracture of the graft in ten patients, nonunion of the proximal osteotomy in seven, and infection in five. In the osteoarticular group, three of 11 patients developed radiological evidence of severe osteoarthritis, but only one was symptomatic and required conversion to ankle arthrodesis. Functional evaluation showed higher values of the Musculoskeletal Tumour Society (MSTS) and American Orthopaedic Foot and Ankle Society (AOFAS) scores in the intercalary group compared with the others. Preservation of the epiphysis in patients with a distal tibial bone tumour is a safe and effective form of limb-sparing treatment. It requires rigorous preoperative planning after accurate analysis of the imaging. When joint-sparing resection is not indicated, ankle arthrodesis, either isolated tibiotalar or combined tibiotalar and subtalar arthrodesis, should be preferred over osteoarticular reconstruction. Cite this article: Bone Joint J 2020;102-B(11):1567-1573.

Does Osteoarticular Allograft Reconstruction Achieve Long-term Survivorship after En Bloc Resection of Grade 3 Giant Cell Tumor of Bone?

En bloc resection of benign tumors is only indicated in aggressive lesions with substantial destruction of the affected bone. Few reports have evaluated the long-term outcome of Grade 3 giant cell tumor of bone (GCTB; defined as severe bone destruction and soft tissue extension) treated with en bloc resection and reconstruction with a massive allograft. We recently reported that patients with benign tumors achieved better allograft reconstruction survivorship compared with those treated for a malignant bone tumor. In light of that finding, we wondered whether osteoarticular allografts would be a viable long-term alternative for Grade 3 GCTB, which could be important in some countries because of greater availability and lower costs compared with endoprostheses. We analyzed a group of patients with Grade 3 GCTBs treated with en bloc resection and osteoarticular allograft reconstruction in terms of (1) survivorship free from allograft removal at 10 years; (2) survivorship free from reoperation for any reason at 10 years, (3) functional results as measured by the Musculoskeletal Tumor Society (MSTS) score, (4) assessment of arthrosis at the knee. We retrospectively analyzed all patients with a Grade 3 GCTB treated between 1980 and 2007. Only patients treated with en bloc resection and reconstruction with massive osteoarticular allografts were included in the analysis. The indication for osteoarticular reconstruction during that time included severe bone destruction with intraarticular compromise of the tumor, intraarticular fracture because of tumor growth, the presence of inadequate remaining subchondral bone to resist normal loading (for the distal femur or proximal tibia), and the preservation of a soft-tissue component (ligaments or meniscus) for articular stability. During the period, 75 patients were treated with en bloc resection. Patients treated with intralesional curettage (n = 7), reconstruction with an endoprosthesis (n = 2), intercalary arthrodesis (n = 13), or unicondylar reconstruction (n = 14) were excluded. Of the original 75 treated with en bloc resection, 52% (39) were treated with osteoarticular allograft reconstruction, and no patient was lost to follow-up before 2 years or had substantial missing data. However, of the 39 patients, another 21% (8) have not been seen in the last 5 years, but these were included here because they reached the 10-year minimum surveillance period before being lost. Twenty-three of those 39 patients were previously reported by our group and 16 new patients (treated between 1980-1985) were included in this series (eight distal radius, six distal femur, two proximal tibias), extending the follow-up period and including more patients for analysis. The median (range) follow-up duration was 26 years (10 to 34). We assessed survivorship using a Kaplan-Meier analysis, we drew MSTS scores retrospectively from patients´ medical records, and we graded arthrosis using the Ahlbäck scale for the knee (which was by far the most common joint involved, n = 31, and so it was the joint we assessed for the presence of arthrosis). The survivorship free from allograft removal was 85% at 10 years (95% CI 74 to 96). The allograft survivorship free from reoperation for any reason at 10 years was 72% (95% CI 59 to 87). The median (range) MSTS score was 28 points (19 to 30). The grade of arthrosis in the knee at last follow-up was analyzed in 20 patients and classified in nine as Ahlbäck Type 4, in six as Type 3, in three as Type 2 and in two as Type 5. Osteoarticular allograft reconstruction after a Grade 3 GCTB en bloc resection showed excellent long-term survivorship. We believe these results compare favorably with other studies on endoprosthetic reconstruction and head-to-head studies of these approaches should be performed; these would need to be multicenter trials. In the meantime, in locations where endoprostheses are unavailable or too expensive, we believe our results support the use of osteoarticular allografts. Level IV, therapeutic study.

Wrist Arthrodesis and Osteoarticular Reconstruction in Giant Cell Tumor of the Distal Radius

The aim of this multi-institutional retrospective study was to compare osteoarticular graft reconstruction (OA) and wrist arthrodesis (WA) after distal radius resection for giant cell tumor. Sixty-seven patients affected by giant cell tumor of the distal radius underwent resection and reconstruction with OA (47 patients) or WA (20 patients). The mean age was 40 years (range, 13-74 years). Grafts included fresh-frozen allograft or nonvascularized fibular autograft. Complications requiring surgical revision were recorded. Clinical outcome was assessed with the Musculoskeletal Tumour Society Score (MSTS) and Disabilities of the Arm, Shoulder, and Hand (DASH) score. Fifteen patients developed a local recurrence after a median of 12 months (range, 6-137 months). Sixteen patients required revision surgery for complications. Of these, 10 were graft-related complications (7 in the OA group and 3 in the WA group). Among OA, 2 patients with painful instabilities and 4 with severe arthritis required conversion into WA after a mean of 26 months (range, 13-38 months) At a median follow-up of 105 months (range, 12-395 months), similar functional outcome (MSTS and DASH score) was observed between OA and WA. Our results did not show any advantage of OA or WA over the other technique. A patient-by-patient decision should be taken both regarding the type of reconstruction (OA or WA) and the type of graft (allograft or autograft). The reconstructive choice should also consider the patient's functional expectations. Therapeutic IV.

Reconstructive Challenges of Proximal Ulnar Bone Tumors: Our Experience with Biological Osteoarticular Reconstruction Using Extracorporeal Irradiation and Reimplantation.

Introduction Limb salvage surgery following proximal ulna resection poses a challenge in reconstruction of the complex elbow anatomy. Various reconstruction methods described offer inadequate restoration of function and stability. Following resection of proximal ulna tumors, we aimed to restore the joint using the resected osteochondral segment of proximal ulna treated with extracorporeal irradiation and reimplantation. Questions/Purposes (1) Does irradiated osteoarticular autograft reconstruction for proximal ulna allow anatomical joint restoration and what are the oncological and functional outcomes? (2) Is there evidence of graft-related complications or osteoarthritis at a minimum of 2 years follow-up with irradiated osteoarticular autografts for the proximal ulna? (3) How does our method of reconstruction fare as compared to reported reconstruction options in the literature? Materials and Methods. 3 patients with primary bone tumors involving the proximal ulna underwent limb salvage surgery with en bloc resection and reconstruction using the resected bone after treating it with extracorporeal irradiation of 50 Gy. Minimum follow-up of 2 years was considered for assessment of final outcomes. Radiographs were assessed for bony recurrence, union across osteotomy junction, and signs of joint arthritis. Functional outcome measures included range of movement, muscle power testing, and functional and disability scores. Results 2 complete and 1 partial olecranon involving proximal ulnar resections were performed for three cases of Ewing's sarcoma in 2 males and 1 female. Follow-up ranged from 28 to 42 months, and all patients continue to remain disease free. All 3 patients have achieved full range of flexion-extension and pronosupination movement in comparison to the contralateral side. Muscle power for flexion and extension was 5/5. MSTS score: 100% (30/30); MEPS score: 100; and DASH score: zero were achieved for all patients. Union across osteotomy junctions at median follow-up of 8 months without need for intervention/bone grafting was achieved. No complications related to joint laxity/subluxation, infection, graft fracture, or implant failure was noted. None of the patients have clinical or radiological signs of joint arthritis across the irradiated articulation. Conclusion Biological restoration of elbow anatomy using osteoarticular irradiated graft for proximal ulna reconstruction offers great joint stability and functional outcomes. Although the potential risks of infection and graft failure need to be considered, reconstruction with the size-matched radiated autograft eliminates donor site morbidity, offers a low-cost alternative to endoprosthesis, and provides outcomes superior to any other methods of reconstruction as analyzed from the literature.

Long-term Results of Osteoarticular Allograft Reconstruction in Children with Distal Femoral Bone Tumors.

There is no consensus regarding the best method of reconstruction in pediatric population following the wide resection of malignant bone tumors. More exploration of the complications of osteoarticular reconstruction leads to less existing controversy of this type of reconstruction, which is the main point of this article. Long-term outcomes and complications of osteoarticular allograft reconstruction of primary distal femoral bone sarcomas in 22 children with mean age of 10.7 years old were reviewed in this study. Musculoskeletal Tumor Society (MSTS) scoring system was used for functional evaluation of the allografts. With an average follow-up time of 81 months, the outcomes of 16 patients with allografts at the final follow up were evaluated. As expected, Limb length discrepancy (LLD) was observed in all patients (mean LLD= 2.73cm), which was significantly correlated to allograft survival time (P<0.001). Degenerative joint disease (DJD) was also seen in all patients and its grade was also significantly correlated to allograft survival time (P<0.001). The mean MSTS-score was 74% at the latest follow-up, ranging from 60% to 90%. Five and 10 year survival rate of allografts were found to be 93.3% and 62.2%, respectively. Osteoarticular allograft reconstruction could result in several complications including DJD. Despite its considerable biologic advantage over endoprosthesis, osteoarticular allograft reconstruction is a long-lasting but still a temporary solution before performing megaprosthesis. This allows patients to preserve their remaining physis for limb growth and become old enough for an adult megaprosthesis.

En bloc Excision and Matched Metatarsal Transfer for Expansive Benign Osteolytic Lesions of the Metacarpal

Benign aggressive expansile osteolytic lesions such as giant cell tumors and aneurysmal bone cysts involving the metacarpal head pose problems in management. Unacceptably high rates of recurrence are reported after curettage and bone grafting. An en bloc excision of such tumors ideally requires osteoarticular replacement of the excised metacarpal heads to retain mobility and function. We used nonvascularized metatarsal head and shaft harvested from the foot to replace the metacarpal defect after en bloc resection to retain movement and function of metacarpophalangeal (MCP) joint. The purpose of this study was to evaluate results of patients who underwent this procedure. Nine patients treated with metatarsal transfer for osteoarticular reconstruction after en bloc excision of benign aggressive osteolytic metacarpal head tumors were reviewed retrospectively. The postoperative evaluation included examination of radiographs, joint mobility, and patient rated return of function using the Michigan Hand Questionnaire. Of 9 patients, 4 had aneurysmal bone cyst, 4 had giant cell tumor, and 1 an atypical cartilaginous lesion. Patients were aged between 14 and 45 years at the time of surgery. After an average of 44 months of follow-up (minimum follow-up of 24 months; range, 24-104 months), all patients had good postoperative function, satisfactory results, and no recurrence of tumor. The mean active range of motion at the reconstructed MCP joint was 75° (range, 0° to 90°). The Michigan Hand Questionnaire score averaged 80 (range, 69-92). No patient complained of donor site morbidity. One patient underwent MCP joint fusion after a pin tract infection. Use of a matched metatarsal graft for osteoarticular reconstruction after en bloc excision of benign aggressive tumors involving the metacarpal head is a potential treatment option. In this limited series, consistent results with respect to functional range of motion atMCP joint, and without recurrence of tumor or notable donor site morbidity were obtained. Therapeutic IV.

Topographic matching of distal radius and proximal fibula articular surface for distal radius osteoarticular reconstruction.

During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined.

Mid-term radiological and functional results of biological reconstructions of extremity-located bone sarcomas in children and young adults.

Biological reconstruction is a useful option for reconstruction following bone sarcoma resection in children. The mid-term functional and radiological outcomes of biological reconstructions after resection of bone sarcomas in children are presented in this study. Eighteen patients [average age 12.5 years (range 4-22 years)] with primary sarcomas of long bones underwent wide surgical resection and biological reconstruction. The bone defects were managed by intercalary (n=14), osteoarticular (n=3) reconstructions and arthrodesis (n=1) with a vascularized fibular graft (VFG). VFG was combined with a massive allograft in seven lower extremity reconstructions. The average follow-up was 45.7 months (range 25-78 months). Graft union and graft hypertrophy was observed in 17 (94.4%) of 18 patients at 12 months. The VFG-allograft osteointegration rate was 100% at 24 months. The average final follow-up Musculoskeletal Tumor Society (MSTS) scores for lower and upper extremity reconstructions were 79.7% (range 66.6-90%) and 80.9% (range 53.3-100%), respectively. Four (22.2%) complications, including nonunion (n=1), implant failure (n=1), infection (n=1) and skin necrosis (n=1), required reoperation. The disease relapsed in three (16.6%) patients. Defect size and VFG length did not correlate with MSTS scores and radiological parameters (P>0.05). Biological reconstruction with VFG can provide permanent stability and progressively increasing functional and radiological results.

What was the survival of megaprostheses in lower limb reconstructions after tumor resections?

Prosthetic replacement is the most commonly used option for reconstruction of osteoarticular bone loss resulting from bone neoplasm resection or prosthetic failure. Starting in late 2001, we began exclusively using a single system for large-segment osteoarticular reconstruction after tumor resection; to our knowledge, there are no published series from one center evaluating the use of this implant. We investigated the following issues: (1) What is the overall survival, excluding local tumor recurrence, for these endoprostheses used for tumor reconstructions of the lower extremities (knee and hip)? (2) What types of failure were observed in these reconstructions? (3) Do the survival and complications vary according to site of implant? Between September 2001 and March 2012, we exclusively used this implant for tumor reconstructions. During that time, 278 patients underwent tumor reconstructions of the hip or knee, of whom 200 (72%) were available at a minimum 2 years followup. Seventy-eight patients were excluded from the study for insufficient followup as a result of early death (42) or loss at followup (36). The reconstruction types were the following: proximal femur (69 cases), distal femur (87), proximal tibia (32), and total knee (12). Failures were classified according to the Henderson classification. Nine patients among those with followup shorter than 2 years had presented one or more failures and they were included in our analysis but separately evaluated. Overall survival (no further surgical procedures of any type after primary surgery), excluding Type 5 failure (tumor recurrence), was 75.9% at 5 years and 66.2% at 10 years. Seventy-one failures occurred in 58 implants (29%). Mechanical failures accounted for 59.2% and nonmechanical failures for 40.8%. The first causes of failure of the implants were the result of soft tissue failure in 6%, aseptic loosening in 3%, structural failure in 7%, infection in 8.5%, and tumor recurrence in 4.5% of the whole series. Nine implants sustained two or more failures. Overall incidence of infection was 9.5%. No statistically significant differences were observed according to anatomical site. Like in the case with many such complex oncologic reconstructions, the failure rate at short- to midterm in this group was over 20%. Comparative trials are called for to ascertain whether one implant is superior to another. Infection and structural failure were the most frequent modes of failure in our experience. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Allograft Reconstruction for the Treatment of Musculoskeletal Tumors of the Upper Extremity

In comparison with the lower extremity, there is relatively paucity literature reporting survival and clinical results of allograft reconstructions after excision of a bone tumor of the upper extremity. We analyze the survival of allograft reconstructions in the upper extremity and analyze the final functional score according to anatomical site and type of reconstruction. A consecutive series of 70 allograft reconstruction in the upper limb with a mean followup of 5 years was analyzed, 38 osteoarticular allografts, 24 allograft-prosthetic composites, and 8 intercalary allografts. Kaplan-Meier survival analysis of the allografts was performed, with implant revision for any cause and amputation used as the end points. The function evaluation was performed using MSTS functional score. Sixteen patients (23%) had revision surgery for 5 factures, 2 infections, 5 allograft resorptions, and 2 local recurrences. Allograft survival at five years was 79% and 69% at ten years. In the group of patients treated with an osteoarticular allograft the articular surface survival was 90% at five years and 54% at ten years. The limb salvage rate was 98% at five and 10 years. We conclude that articular deterioration and fracture were the most frequent mode of failure in proximal humeral osteoarticular reconstructions and allograft resorption in elbow reconstructions. The best functional score was observed in the intercalary humeral allograft.

Unicondylar osteoarticular allograft reconstruction of the distal femur in a patient with a traumatic osteoaticular defect of the lateral femoral condyle

The objective of this study was to report the clinical results for a patient with a post-traumatic osteoarticular defect of the lateral femoral condyle treated with unicondylar osteoarticular allograft reconstruction. We describe the case with a massive osteoarticular loss of the lateral femoral condyle combined with a grade IIIA open distal femoral diaphyesal fracture. The patient underwent unicondylar osteoarticular reconstruction with an allogenic fresh-frozen condyle. There were no complications after the reconstructive procedure. At the five year follow-up, the patient showed a favorable clinical outcome with a full range of motion of the knee joint. Degenerative changes were seen in the graft compartment, but they did not cause serious functional limitations. Unicondylar allograft reconstruction appears to be a surgical option for patients who suffer from a post-traumatic distal femoral osteoarticular defect in which only one condyle is absent or severely damaged.

MESENCHYMAL STEM CELLS – A BIOLOGICAL ALTERNATIVE IN OSTEOARTICULAR RECONSTRUCTION IN DOGS

Mesenchymal stem cells (MSC) posses the ability to differentiate into any type of somatic cells if properly stimulated. This study documented the effects of using mesenchymal stem cells loaded scaffolds in repairing large bone and cartiladge defects in dogs. The innovative aproach to osteoarticular reconstruction in dogs by using auto- or alogenic MSC loaded scaffolds, opens up new possibilities for treating diverse conditions with bioreactive materials and cells. The MSC were obtained from the humeral bone marrow aspirates. The multipotent cells underwent a specific cultivation and differentiation protocol, derived from the standard procedure. The protocol was altered to best fit the cells behaviour as it follows: the cultivation period needed to reach the 60-80% junction point, differed from dog to dog as well as the potency of the cell cultures, this determining the moment of their passage; the MSC were poured on the scaffolds and only then the diffentiation medium was added, this allowing the cells to differentiate on the osteogenic and osteoinductive material, thus obtaining a better cell load and disposition of the bioactive scaffold.

Techniques for dog bone marrow stromal cells sampling, culturing, differentiation and loading scaffolds.

The bone marrow is composed of the non-adherent hematopoietic and adherent stromal cell compartments. This adherent bone marrow stromal cell fraction contains pluripotent mesenchymal stem cells and differentiated mesenchymal bone marrow stromal cells. In vivo the mesenchymal stem cells self-renew by proliferation while maintaining their stem-cell phenotype and give rise to the differentiated stromal cells which belong to different lineages. This experimental study demonstrate that mesenchymal stem cells from dog bone marrow had the in vitro capability to differentiate in osteogenic and chondrogenic lineages after culture in proper media and these properties can be used in osteoarticular reconstruction if the differentiated cells had a suitable support.

Proximal Humerus Reconstructions for Tumors

The optimal method for reconstructing the proximal humerus in patients with tumors is controversial. To determine functional outcomes and complication rates after different types of reconstructions, we reviewed a consecutive series of 49 patients who underwent proximal humerus resection and osteoarticular allograft (17 patients), allograft-prosthetic composite (16), or endoprosthetic (16) reconstruction. Operative indications included primary malignancies (24 patients), metastatic disease (19), and benign aggressive disease (six). Implant revision was more common after osteoarticular reconstruction (five of 17) than after allograft-prosthetic composite (one of 16) or endoprosthetic (zero of 16) reconstructions. At a minimum followup of 24 months (median, 98 months; range, 24-214 months) in surviving patients, Musculoskeletal Tumor Society functional scores averaged 79% for the allograft-prosthetic composite, 71% for the osteoarticular allograft, and 69% for the endoprosthetic reconstruction cohorts. Shoulder instability was associated with abductor mechanism compromise and was more common after endoprosthetic reconstruction. Allograft fractures occurred in 53% of patients receiving osteoarticular allografts. We recommend allograft-prosthetic composite reconstruction for younger patients with primary tumors of bone and endoprosthetic reconstruction for older patients with metastatic disease. Because of the unacceptable complication rate, we do not recommend osteoarticular allograft reconstruction for routine use in the proximal humerus. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Pelvic reconstruction using massive frozen autograft bearing tumor

9040 Background: Allograft is difficult to obtain in Japan for socioreligious reasons, so autograft bone, such as irradiation, autoclaving and pasteurization et al, has been widely used. However, they may cause weakness of the treated bone and loss of bone induction activity. So we developed a new method for treating autografts that utilizes the hypothermic effect of liquid nitrogen, especially reconstruction after the resection of illiosacral joint or periacetabulum, based on the results of in vitro and in vivo studies. Methods: Six patients with pelvic malignant bone tumors (2 chondrosarcomas, 1 osteosarcoma, 1 Ewing sarcoma and 2 metastatic tumors) were treated with this method. All these tumors invaded illiosacral joint or periacetabulum, the type of resection were P14P4, P14, P123, P124, P2and P12P12 according to Enneking's classification. After tumor excision, the tumor and surrounding soft tissue were removed, and the specimen was immediately frozen in liquid nitrogen for 20 minutes. Later, the specimen was gradually thawed at room temperature and in distilled water. Finally reconstructed with liquid nitrogen autograft, osteosynthesis with suitable internal fixation. Results: With a mean follow-up of 18 months, union of host-graft junction was observed in 6 patients in 5.5 months after surgery, and the reconstruction of pelvic ring was complete in 5 patients. Osteoarticular reconstruction was performed perfectly for 6 patients. Excellent function was found in 3 patients, good in one, fair in one and poor in one. As for complications, there were two deep infections, frozen autograft was removed in one patient, the other patient was given debridement and the infection subsided eventually. Bone absorption and fracture were not found. One local recurrence arised from residual soft tissue. Three patients were still free of disease and three had died of metastatic disease. Conclusions: This biological reconstruction is considered to be a new and promising option in pelvic and sacral tumor, because it can provide perfect matching and immediate stability. No significant financial relationships to disclose.

Functional Laboratory Assessment After Oncologic Shoulder Joint Resections

A laboratory evaluation was undertaken to assess the shoulder range of motion and distal strength after oncologic resection and reconstruction involving the shoulder joint and to compare these functional parameters based on potentially important variables. Inclusion in the study was limited to 32 patients with bone tumors of the proximal humerus or scapula treated surgically by resection of the shoulder joint including the proximal humerus from 1976 through 1992. Active shoulder range of motion and isometric elbow extension and forearm supination strength are significantly less after surgery in patients with greater amounts of bony resection and with resection of the deltoid. Patients who had a modified Tikhoff-Linberg resection were able to achieve 10 degrees to 15 degrees greater shoulder motion in each direction than were patients who had the classic procedure including complete scapulectomy. However, elbow flexion and extension strength and forearm pronation strength were greater for the patients with the classic resection. Osteoarticular allografts as a reconstructive alternative provide as a group the best shoulder motion and overall distal upper extremity strength, but these reconstructions were performed only when the rotator cuff muscles and deltoid were able to be reconstructed. Diminishing elbow strength was seen with longer followup in the patients with osteoarticular reconstructions, corresponding temporally to subchondral collapse observed on radiographs. Range of shoulder motion except rotation was just as good for allograft vascularized fibular arthrodeses as for the osteoarticular allografts, but strength was significantly less with the arthrodeses.