Does Microwave Ablation of the Tumor Edge Allow for Joint-sparing Surgery in Patients With Osteosarcoma of the Proximal Tibia?

Background

Joint-sparing surgery of a patient’s native joint for osteosarcoma likely affords better function and comparable survival. However, it sometimes is challenging to resect a juxtaarticular osteosarcoma in a way that preserves the affected epiphysis because wide margins are necessary to minimize the risk of local recurrence. If there was a method to resect a tumor close to the joint and treat a potentially positive margin to prevent recurrence, it might allow salvage of a joint that otherwise might be lost.

Questions/purposes

We therefore asked (1) whether joint-preserving tumor resection could be performed for juxtaarticular osteosarcoma after microwave ablation of the tumor edge under navigation without leading to local recurrences, (2) what is the resulting function, and (3) what are the complications associated with this procedure.

Methods

Between 2009 and 2011, we treated 11 patients who had juxtaarticular osteosarcoma of the proximal tibia (mean age, 12 years; range, 9–16 years) with joint-preserving surgery by transepiphysis tumor resection after navigation-assisted microwave ablation of the tumor edge; they were followed a minimum of 37 months (mean, 48 months; range 37–62 months), and none was lost to followup. Patients were considered eligible for this procedure if they had a distance from the tumor edge to the articular surface between 10 to 15 mm, good chemotherapy responses, no pathologic fracture and no tumor involvement of major neurovascular structures. Allograft in combination with a vascularized fibula flap was used for segmental reconstruction. We recorded local tumor control, complications, and functional outcomes using the Musculoskeletal Tumor Society score, which ranges from 0 to 30, with higher scores indicating better function.

Results

There were no local recurrences. Major complications included osteonecrosis of part of the epiphysis in two patients and deep infection in one. The Musculoskeletal Tumor Society score ranged from 26 to 30 with a mean of 29.

Conclusions

In selected patients with osteosarcoma invading the epiphysis, navigated resection facilitates performing joint-sparing surgery, and in our small series, the adjuvant microwave ablation seemed to provide adequate local tumor control. Although more experience and longer followup are needed, this approach may make it possible to salvage more native joints when performing limb salvage for osteosarcoma.

Level of Evidence

Level IV, therapeutic study.     

Is the Induced-membrane Technique Successful for Limb Reconstruction After Resecting Large Bone Tumors in Children?

Background

Resection of primary malignant tumors often creates large bony defects. In children, this creates reconstructive challenges, and many options have been described for limb salvage in this setting. Studies have supported the use of an induced-membrane technique after placement of a cement spacer to aid in restoration of bone anatomy.

Questions/purposes

We asked: (1) What complications are associated with the induced-membrane technique? (2) How often is bone healing achieved after resection greater than 15 cm using this technique? (3) What is the functional outcome of patients treated with this technique?

Methods

We performed a retrospective evaluation of eight patients with a mean age of 13.3 years (range, 11–17 years) treated for a malignant bone tumor between 2002 and 2012 at our centers. The primary malignant tumors involved the proximal humerus, femur, and tibia. All patients were treated using the induced-membrane technique after a resection with mean bone loss of 18 cm (range, 16–23 cm). The general indication for using the induced-membrane technique during this time was a large diaphyseal defect after resection of the tumor. In addition to using cancellous graft as with the original technique, in the current patients an autogenous nonvascularized fibula was used to enhance stability. The patients were assessed at the last followup using the Musculoskeletal Tumor Society (MSTS) scoring system. Mean followup was 47.1 months (range, 24–120 months), and none of the patients were lost to followup before 2 years.

Results

A total of four unplanned reoperations were performed in these eight patients. A fracture of the reconstruction occurred in three patients and all were treated successfully, two with surgery and one with immobilization. Bone fusion was obtained in all patients within 4 to 8 months (mean, 5.6 months) after the reconstruction. The mean healing index was 0.31 month/cm of reconstruction (range, 0.23–0.5 month/cm). At last followup, the mean MSTS score was 74% (range, 67%–80%).

Conclusions

Our findings suggest that the modified induced-membrane technique is a reasonable alternative to other limb reconstruction techniques for bone tumors in children and has the advantage of not requiring a bone bank or an expensive metal prosthesis. Although more patients will be needed to substantiate our findings, it has become a standard part of our arsenal in the treatment of large bone defects after resection of pediatric primitive bone tumors.

Level of Evidence

Level IV, therapeutic study.     

Reconstruction by bone transport after resection of benign tumors of tibia: A retrospective study of 38 patients

Background:

The commonly used reconstructive options after post resection defects in bone tumors like megaprosthesis, autograft, allograft, bone graft substitutes and recycled bone have their own demerits on a long term. Bone transport that regenerates patient''s own bone is a less explored option of reconstruction after resection of benign bone tumors and reports on this are limited. This technique is very much relevant in tibia where Ilizarov fixator is surgeon and patient friendly. We report our experience.

Materials and Methods:

This is a retrospective series of resection and bone transport in 38 patients with benign tumor of tibia. There were 14 males and 24 females with mean age of 23.40 years (range 9–40 years). Lesion was located in proximal third tibia in 27, middle third in two and distal third in nine patients. The diagnosis was giant cell tumor in 32, chondroblastoma in three, chondromyxoid fibroma, enchondroma and desmoplasic fibroma in one patient each. The resection was intercalary in 28 and transarticular in 10 patients. Osteosynthesis was monofocal in three, bifocal in 31 and polyfocal in four cases.

Results:

Mean followup was 7.22 years (range 1.5–15 years). Mean resection length was 10.21 cm (range 3–22 cm). The mean duration of external fixator was 308.03 days (range 89–677 days) and mean external fixator index was 36.14 days/cm (range 16.84–97.43 days/cm). Twelve patients had difficulties in the form of 11 problems and five obstacles that were successfully managed. None of the patients had local recurrence of tumor or any long term complication. Mean Musculo-skeletal Tumour Society score at final followup was 27.18 (90.60%).

Conclusions:

Bone transport is an excellent option after resection of benign tumors of tibia with good local control and functional outcome, despite minor difficulties that need timely management.     

Total Femur Replacement After Tumor Resection: Limb Salvage Usually Achieved But Complications and Failures are Common

Background

Primary bone or soft tissue tumors of the femur sometimes present with severe and extensive bone destruction, leaving few limb-salvage options other than total femur replacement. However, there are few data available regarding total femur replacement and, in particular, regarding implant failures.

Questions/purposes

We asked: (1) What are the revision-free and overall implant survival rates of conventional total femur replacements in patients treated for sarcoma of the femur or soft tissues? (2) What are the revision-free and overall implant survival rates of expandable total femur replacements in skeletally immature patients? (3) Using the comprehensive International Society of Limb Salvage failure-mode classification, what types of complications occur with conventional and expandable total femur replacements?

Patients and Methods

Our retrospective, single-center cohort study was based on data prospectively collected for 50 patients who received a total femur replacement after tumor resection for indications other than carcinoma or metastatic disease. Of the 50 patients, six (12%) were lost to followup before 6 months. Ten of the remaining 44 patients received expandable implants. The mean followup was 57 months (range, 1–280 months) and 172 months (range, 43–289 months) for patients who underwent conventional and expandable total femur replacements, respectively. For implant survival, competing risk analyses were used.

Results

At 5 years, revision-free implant survival of conventional total femur replacements was 48% (95% CI, 0.37–0.73), and overall implant survival was 97% (95% CI, 0.004–0.20). Five-year revision-free implant survival of expandable total femur replacements was 30% (95% CI, 0.47–1.00) and overall implant survival was 100%. With conventional total femur replacements soft tissue failures occurred in 13 of 34 patients, structural failures in three, infection in six, and local tumor progression in one. No patient had aseptic loosening with conventional total femur replacements, but hip disarticulation occurred in two patients owing to extensive wound-healing problems and infection. With expandable total femur replacements soft tissue failure, aseptic loosening, and infection occurred in one patient each of 10, and structural failures in three of 10 (two periprosthetic fractures, one loosening of an enhanced tendon anchor). No hip disarticulations were performed. Additionally expandable total femur replacement-related failures included hip instability in eight of 10 patients, contractures attributable to massive scar tissue in six, and defect of the implant’s expansion mechanism in four patients.

Conclusions

Although the indications for total femoral resection are rare, we think that total femur replacement is a reasonable treatment option for reconstruction of massive femoral bone defects after tumor resection in adults and skeletally immature patients, and results in limb salvage in most patients.

Level of Evidence

Level IV, therapeutic study.     

Survival,Recurrence, and Function After Epiphyseal Preservation and Allograft Reconstruction in Osteosarcoma of the Knee

Background

Bone tumor resections for limb salvage have become the standard treatment. Recently, intercalary tumor resection with epiphyseal sparing has been used as an alternative in patients with osteosarcoma. The procedure maintains normal joint function and obviates some complications associated with osteoarticular allografts or endoprostheses; however, long-term studies analyzing oncologic outcomes are scarce, and to our knowledge, the concern that a higher local recurrence rate may be an issue has not been addressed.

Questions/purposes

We wanted to assess (1) the overall survival in patients treated with this surgical technique; (2) the percentage of local recurrence and limb survival, specifically the incidence of recurrence in the remaining epiphysis; (3) the frequency of orthopaedic complications, and, (4) the functional outcomes in patients who have undergone intercalary tumor resection.

Methods

We analyzed all 35 patients with osteosarcomas about the knee (distal femur and proximal tibia) treated at our center between 1991 and 2008 who had resection preserving the epiphysis and reconstruction with intercalary allografts. Minimum followup was 5 years, unless death occurred earlier (mean, 9 years; range, 1–16 years), and no patients were lost to followup. During the study period, our indications for this approach included patients without metastases, with clinical and imaging response to neoadjuvant chemotherapy, that a residual epiphysis of at least 1 cm thickness could be available after a surgical margin width in bone of 10 mm was planned, and 16% of patients (35 of 223) meeting these indications were treated using this approach. Using a chart review, we ascertained overall survival of patients, oncologic complications such as local recurrence and tumor progression, limb survival, and orthopaedic complications including infection, fracture, and nonunion. Survival rates were estimated using the Kaplan-Meier method. Patient function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system.

Results

Overall survival rate of the patients was 86% (95% CI, 73%–99%) at 5 and 10 years. Five patients died of disease. No patient had a local recurrence in the remaining bony epiphysis, but three patients (9%; 95% CI, 0%–19%) had local recurrence in the soft tissue. The limb survival rate was 97% (95% CI, 89%–100%) at 5 and 10 years. Complications treated with additional surgical procedures were recorded for 19 patients (54%), including three local recurrences, two infections, 11 fractures, and three nonunions. In 10 of these 19 patients, the allograft was removed. Only five of the total 35 study patients (14%) lost the originally preserved epiphysis owing to complications. The mean functional score was 26 points (range, 10–30 points, with a higher score representing a better result) at final followup.

Conclusions

Although the recurrence rate was high in this series, the small sample size means that even one or two fewer recurrences might have resulted in a much more favorable percentage. Because of this, future, larger studies will need to determine whether this is a safe approach, and perhaps should compare epiphyseal preservation with other possible approaches, including endoprosthetic reconstruction and/or osteoarticular allografts.

Level of Evidence

Level IV, therapeutic study.     

Resection arthrodesis for the management of aggressive giant cell tumor of the distal femur

Background:

Giant cell tumors (GCTs) of bone are aggressive benign tumors. Wide resection is reserved for a small subset of patients with biologically more aggressive, recurrent, and extensive tumors. Wide resection and mobile joint reconstruction are preferable for treating tumors around the knee. In certain situations, resection arthrodesis or an amputation is suggested. In this prospective study we report the outcome of 8 patients of aggressive GCT of lower end of femur treated with resection arthrodesis.

Materials and Methods:

Eight patients with mean age of 37.25 years (range 30–45 years) with Campanacci Grade III (Enneking stage III) giant cell tumors at the distal femur were treated with wide resection and arthrodesis using dual free fibular graft and locked intramedullary nail from January 2003 to January 2008. There were four males and four females patients. The mean follow-up was 48.75 months (range 30–60 months). The functional evaluation was done using the standard system of musculoskeletal tumor society with its modification developed by Enneking et al.

Results:

At the final follow up the functional score ranged from 20 to 27 out of total score of 30. Graft union was achieved in all cases in a duration mean of 14.5 months (range 12-20 months).One case required secondary bone graft due to delayed union, and one case had superficial wound infection which healed on systemic antibiotics. At final followup, all the patients were disease free.

Conclusion:

Wide resection and arthrodesis in aggressive GCTs of the distal femur with involvement of all muscle compartments is a good treatment option. Resection arthrodesis offers a biological reconstruction alternative to amputation in a special group of patients when extensive resection precludes mobile joint reconstruction.     

Are Complications Associated With the Repiphysis? Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

Background

Reconstruction of the distal femur after resection for malignant bone tumors in skeletally immature children is challenging. The use of megaprostheses has become increasingly popular in this patient group since the introduction of custom-made, expandable devices that do not require surgery for lengthening, such as the Repiphysis^® Limb Salvage System. Early reports on the device were positive but more recently, a high complication rate and associated bone loss have been reported.

Questions/purposes

We asked: (1) what are the clinical outcomes using the Musculoskeletal Tumor Society (MSTS) scoring system after 5-year minimum followup in patients treated with this prosthesis at one center; (2) what are the problems and complications associated with the lengthening procedures of this implant; and (3) what are the specific concerns associated with revision of this implant?

Methods

At our institute, between 2002 and 2007, the Repiphysis^® expandable prosthesis was implanted in 15 children (mean age, 8 years; range, 6–11 years) after distal femoral resection for malignant bone tumors. During this time, the general indication for use of this implant was resection of the distal femur for localized malignant bone tumors in pediatric patients. Alternative techniques used for this indication were modular prosthetic reconstruction, massive (osteoarticular or intercalary) allograft reconstruction, or rotationplasty. Age and tumor extension were the main factors to decide on the surgical indication. Of the 15 patients who had this prosthesis implanted during reconstruction surgery, five died with the implant in situ or underwent amputation before 5 years followup and the remaining 10 were evaluated at a minimum of 5 years (mean, 104 months; range, 78–140 months). No patients were lost to followup. These 10 patients were long-term survivors and underwent the lengthening program. They were included in our study analysis. The first seven lengthening procedures were attempted in an outpatient setting; however, owing to pain and burning sensations experienced by the patients, the procedures failed to achieve the desired lengthening. Therefore, other procedures were performed with the patients under general anesthesia. We reviewed clinical data at index surgery for all 15 patients. We further analyzed the lengthening procedures, implant survival, radiographic and functional results, for the 10 long-term survivors. Functional results were assessed according to the MSTS scoring system. Complications were classified according to the International Society of Limb Salvage (ISOLS) classification system.

Results

Nine of the 10 survivors underwent revision of the implant for mechanical failure. They had a mean MSTS score of 64% (range, 47%–87%) before revision surgery. At final followup the 10 long-term surviving patients had an average MSTS score of 81% (range, 53%–97%). In total, we obtained an average lengthening of 39 mm per patient (range, 17–67 mm). Exact expansion of the implant was unpredictable and difficult to control. Nine of 10 of the long-term surviving patients underwent revision surgery of the prosthesis—eight for implant breakage and one for stem loosening. At revision surgery, six patients had another type of expandable prosthesis implanted and three had an adult-type megaprosthesis implanted. In five cases, segmental bone grafts were used during revision surgery to compensate for loss of bone stock.

Conclusions

We could not comfortably expand the Repiphysis^® prosthesis in an outpatient setting because of pain experienced by the patients during the lengthening procedures. Furthermore, use of the prosthesis was associated with frequent failures related to implant breakage and stem loosening. Revisions of these procedures were complex and difficult. We no longer use this prosthesis and caution others against the use of this particular prosthesis design.

Level of Evidence

Level IV, therapeutic study.     

MRI After Patellofemoral Replacement: the Component–Bone Interface and Rotational Alignment

Background

In an earlier paper, it was shown that tailored magnetic resonance imaging (MRI) allows for reproducible analysis of the preserved knee joint structures after patellofemoral replacement (PFR).

Purposes

This pilot study investigates to what degree MRI could produce reliable assessment of the implant–bone interface of femoral and patellar components and rotational alignment following PFR.

Methods

MRI tailored for reduction of metallic artefacts was performed in seven patients who had undergone PFR. Two independent investigators evaluated the implant–bone interface at femoral and patellar components and the rotational alignment of the femoral component. They also assessed their degree of confidence in evaluation using a five-point scale. The inter-observer reliability was determined.

Results

Implant-induced MRI artefact was barely observed and there was no interference with component–bone interface evaluation. There was excellent inter-observer reliability, inter-observer agreement, and confidence for the implant–bone interface at femoral and patellar components and for rotational alignment. The applied score for the interface was found to be reliable.

Conclusion

Tailored MRI allows reproducible analysis of the implant–bone interface and of rotational alignment of the femoral component in patients who have had PFR. It might prove helpful in the assessment of painful PFR.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9336-x) contains supplementary material, which is available to authorized users.     

Uncemented allograft–prosthetic composite reconstruction of the proximal femur

Background:

Allograft–prosthetic composite can be divided into three groups names cemented, uncemented, and partially cemented. Previous studies have mainly reported outcomes in cemented and partially cemented allograft–prosthetic composites, but have rarely focused on the uncemented allograft–prosthetic composites. The objectives of our study were to describe a surgical technique for using proximal femoral uncemented allograft–prosthetic composite and to present the radiographic and clinical results.

Materials and Methods:

Twelve patients who underwent uncemented allograft–prosthetic composite reconstruction of the proximal femur after bone tumor resection were retrospectively evaluated at an average followup of 24.0 months. Clinical records and radiographs were evaluated.

Results:

In our series, union occurred in all the patients (100%; range 5-9 months). Until the most recent followup, there were no cases with infection, nonunion of the greater trochanter, junctional bone resorption, dislocation, allergic reaction, wear of acetabulum socket, recurrence, and metastasis. But there were three periprosthetic fractures which were fixed using cerclage wire during surgery. Five cases had bone resorption in and around the greater trochanter. The average Musculoskeletal Tumor Society (MSTS) score and Harris hip score (HHS) were 26.2 points (range 24-29 points) and 80.6 points (range 66.2-92.7 points), respectively.

Conclusions:

These results showed that uncemented allograft–prosthetic composite could promote bone union through compression at the host–allograft junction and is a good choice for proximal femoral resection. Although this technology has its own merits, long term outcomes are yet not validated.     

Haptic Robot-assisted Surgery Improves Accuracy of Wide Resection of Bone Tumors: A Pilot Study

Background

Accurate reproduction of the preoperative plan at the time of surgery is critical for wide resection of primary bone tumors. Robotic technology can potentially help the surgeon reproduce a given preoperative plan, but yielding control of cutting instruments to a robot introduces potentially serious complications. We developed a novel passive (“haptics”) robot-assisted resection technique for primary bone sarcomas that takes advantage of robotic accuracy while still leaving control of the cutting instrument in the hands of the surgeon.

Questions/Purposes

We asked whether this technique would enable a preoperative resection plan to be reproduced more accurately than a standard manual technique.

Methods

A joint-sparing hemimetaphyseal resection was precisely outlined on the three-dimensionally reconstructed image of a representative Sawbones femur. The indicated resection was performed on 12 Sawbones specimens using the standard manual technique on six specimens and the haptic robotic technique on six specimens. Postresection images were quantitatively analyzed to determine the accuracy of the resections compared to the preoperative plan, which included measuring the maximum linear deviation of the cuts from the preoperative plan and the angular deviation of the resection planes from the target planes.

Results

Compared with the manual technique, the robotic technique resulted in a mean improvement of 7.8 mm of maximum linear deviation from the preoperative plan and 7.9° improvement in pitch and 4.6° improvement in roll for the angular deviation from the target planes.

Conclusions

The haptic robot-assisted technique improved the accuracy of simulated wide resections of bone tumors compared with manual techniques.

Clinical Relevance

Haptic robot-assisted technology has the potential to enhance primary bone tumor resection. Further bench and clinical studies, including comparisons with recently introduced computer navigation technology, are warranted.     

Revision knee arthroplasty with a rotating-hinge design in elderly patients with instability following total knee arthroplasty

Background

Revision knee arthroplasty with a rotating-hinge design could be an option for the treatment of instability following total knee arthroplasty (TKA) in elderly patients.

Purpose

To evaluate the clinical and radiographic results of revision arthroplasties in TKAs with instability using a rotating-hinge design in elderly patients.

Methods

We retrospectively reviewed 96 rotating-hinge arthroplasties. The average age of the patients was 79 years (range, 75–86 years); the minimum follow-up was 5 years (mean, 7.3 years; range, 5–10 years). Patients were evaluated clinically (Knee Society score) and radiographically (position of prosthetic components, signs of loosening, bone loss).

Results

At a minimum followup of 5 years (mean, 7.3 years; range, 5–10 years), Knee Society pain scores improved from 37 preoperatively to 79 postoperatively, and function scores improved from 34 to 53. ROM improved on average from −15° of extension and 80° of flexion before surgery to −5° of extension and 120° of flexion at the last followup (p = 0.03). No loosening of implants was observed. Nonprogressive radiolucent lines were identified around the femoral and tibial components in 2 knees. One patient required reoperation because of a periprosthetic infection.

Conclusions

Revision arthroplasty with a rotating-hinge design provided substantial improvement in function and a reduction in pain in elderly patients with instability following TKA.

Level of evidence

Level IV, therapeutic study.     

Tantalum Cones Provide Durable Mid-term Fixation in Revision TKA

Background

Multiple studies have reported favorable short-term outcomes using tantalum cones to reconstruct massive bone defects during revision TKA. However, longer-term followup is needed to determine the durability of these reconstructions.

Questions/purposes

We wished to determine the mid-term (1) reoperation rates for septic and aseptic causes, (2) radiologic findings of osseointegration, and (3) clinical outcomes based on the Knee Society score in patients who underwent revision knee arthroplasty with tantalum cones for severe bone loss.

Methods

We retrospectively evaluated records of 18 patients (18 knees) who underwent revision knee arthroplasty with use of tantalum cones between 2005 and 2008; the primary indications for use of this approach were to reconstruct massive bone defects classified as Anderson Orthopaedic Research Institute Types 2B and 3. During this period, all defects of this type were treated with this approach and no cones were used for more-minor defects. A total of 26 cones (13 tibial and 13 femoral) were implanted. There were 12 female and six male patients with a mean age of 73 years (range, 55–84 years) at the time of revision. The indication for the revision included aseptic loosening (five patients) and second-stage reimplantation for deep infection (13 patients). Patients were followed for a mean of 6 years (range, 5–8 years). No patient was lost to followup. Clinical and radiographic outcomes were assessed with the Knee Society clinical rating system and radiographic evaluation system.

Results

There have been two reoperations for recurrent infection; at surgery, the two cones showed osseointegration. No evidence of loosening or migration of any implant was noted on the most recent radiographs. Knee Society knee scores improved from a mean of 31 points before surgery to 77 points at latest followup (p < 0.001), and function scores improved from a mean of 22 points to 65 points (p < 0.001).

Conclusions

Tantalum cones for reconstruction of massive bone defects in revision knee arthroplasty provided secure fixation with excellent results at average followup of 6 years, although this series included relatively few patients. These devices are a viable option for surgeons to use in situations with severe bone loss. Further studies with longer followups are needed to confirm the durability of these reconstructions.

Level of Evidence

Level IV, therapeutic study.