Fixed-hinge cemented modular implants: An effective reconstruction technique following primary distal femoral bone tumor resection. A 136-case multicenter series

Induced-membrane technique for lower limb reconstruction after malignant bone tumour resection in paediatric patients: Complication and re-operation rates

BACKGROUND

The objective of this study was to assess the complication and re-operation rates, evaluate the risk of non-union, and describe the functional outcomes at last follow-up in children and adolescents after lower-limb malignant tumour resection and reconstruction using the induced-membrane technique.

HYPOTHESIS

Weight-bearing resumption 6 weeks after the second stage of the induced-membrane procedure promotes bone healing.

MATERIAL AND METHODS

The study included 13 patients (9 with osteosarcoma, 3 with Ewing's sarcomas, and 1 with alveolar sarcoma) managed between 2000 and 2020 by oncological femoral or tibial resection followed, at a distance from adjuvant chemotherapy, by reconstruction using the induced-membrane technique. Non-union was the primary outcome measure and the MusculoSkeletal Tumor Society (MSTS) lower-limb functional score was the secondary outcome measure. Mean follow-up was 6.1 years (range, 2.0-12.7). At last follow-up, mean age was 18.1 years (range, 11.0-26.0) and the mean MSTS score was 66.6% (37.0-93.0%).

RESULTS

After the second reconstruction stage, 8 complications developed in 6 patients (46%). Either a complication or limb-length inequality required 12 re-operations in 8 patients (61.5%). Non-union occurred after reconstruction in 5 (38.5%) patients. Early resumption of 50% weight-bearing 6 weeks after reconstruction was associated with bone healing (p=0.02).

CONCLUSION

The non-union rate was 38.5%. Partial, 50% weight-bearing with two elbow crutches and an orthosis, if allowed by construct stability, may promote bone healing.

LEVEL OF EVIDENCE

IV.

Diagnosis and management of METS-Stanmore Morse taper failure

We describe clinical semiology in 6 cases of METS-Stanmore distal femoral Morse taper impaction failure: from obvious forms with intraprosthetic dislocation to chronic forms with less obvious symptoms: instability, piston sensation, rotational disorder in gait. The diagnostic procedure in chronic forms is described, notably with dynamic examination under fluoroscopy. Reduction and re-impaction by external maneuver can be attempted; in case of failure or of any suspicion of taper disassembly, the 2 modular implant components have to be replaced. Finally, we provide a review of the literature on this rare but serious complication. LEVEL OF EVIDENCE: IV.

What to improve: Results of fixed-hinge knee endoprosthesis reconstructions over 40 years in a single tumor center

INTRODUCTION

Over the past decades, numerous structural changes in implants, medical treatments, and surgical techniques have been made for Malignant Bone Tumors (MBT) around the knee. However, the overall care improvement is still unclear. The method is crucial when analyzing outcomes in surveys involving tumors, and a thorough assessment of the mortality is mandatory because death acts as competing event. The aims of this study were: 1) a comprehensive and longitudinal assessment of the revisions with an extensive follow-up and adequate methods; 2) a complete mortality review to consider competing risks.

HYPOTHESIS

The hypothesis was that some prosthesis's structural improvements were made while the surgical toll increased as well as an improvement of mortality was also expected.

MATERIAL AND METHODS

Analyses were performed on 248 patients with MBT (mean follow-up was 8.7 years, surgeries between 1972 and 2017). Three prosthesis models were successively used over time: 120 Guepar (older model), 42 Tornier, and 86 Stanmore (more recent model). The primary outcome was the assessment of revisions sorted out according to Henderson: type-1 soft-tissue failures or instability, type-2 aseptic loosening, type-3 structural failures, type-4 periprosthetic infections, type-5 tumoral progression. Death and amputations were considered as competing events. An extensive assessment of mortality was performed by merging the dataset with the French register of Deaths (INSEE). Cumulative probabilities were computed at 2, 5, 10, and 15 years and compared with Gray's tests.

RESULTS

The overall 5-year survival was, 80% (95% CI: 73-87) for Guepar, 69% (95% CI: 56-84) for Tornier, and 71% (95% CI: 62-82) for Stanmore (p=0.4). The 5-year cumulative risks for type-1 were 5% (95% CI: 1-9), 9% (95% CI: 0-18), and 17% (95% CI: 9-25) for Guepar, Tornier, and Stanmore, respectively (p=0.01). The 15-year cumulative risks for type-2 were 22% (95% CI: 15-39), 8% (95% CI: 0-17) and 8% (95% CI: 2-14) for Guepar, Tornier, and Stanmore, respectively (p=0.10). Ten patients had an implant failure, nine Guepar, and one Tornier. The 5-year cumulative risks for type-4 were 7% (95% CI: 2-12), 19% (95% CI: 7-31), and 12% (95% CI: 5-18) for Guepar, Tornier, and Stanmore, respectively (p=0.08). There were 29 tumoral progressions; the 15-year risks were 16% (95% CI: 2-22), 2% (95% CI: 0-7%), and 12% (95% CI: 4-19%) for Guepar, Tornier, and Stanmore, respectively (p=0.08). No difference whatsoever was found between the proximal tibial and distal femur.

CONCLUSION

There were some improvements in prosthesis design (forged steel instead of cast steel) and probably also in cemented stem fixation, but not in prosthetic joint infection and local recurrence over forty years. The overall mortality did not change significantly over the last 40 years amongst this specific cohort of patients who benefited from a hinge reconstruction prosthesis.

LEVEL OF EVIDENCE

III; comparative case series with sensibility analysis.

Recovery of leg strength based on isokinetic testing after tumor resection and reconstruction with a modular rotating hinge knee system: Prospective cross-sectional study with a minimum follow-up of 24 months

BACKGROUND

While modular reconstruction implants can be used to replace the bone lost after bone tumor resection, tumor excision from the neighboring soft tissues can lead to loss of strength and joint range of motion (ROM), which results in worse knee function. Functional recovery after total knee arthroplasty for osteoarthritis has been extensively documented. But few studies have evaluated the recovery after total knee reconstruction following tumor excision despite the fact that most of these patients are young and have high functional demands. We did a prospective cross-sectional study to: 1) compare muscle strength recovery around the knee with an isokinetic dynamometer after tumor excision and reconstruction with a modular implant to the healthy contralateral knee; 2) determine if the differences in peak torque (PT) in the knee extensors and flexors had a clinical impact.

HYPOTHESIS

Resection of soft tissues during tumor excision around the knee causes strength loss that cannot be fully recovered.

METHODS

The 36 patients who underwent extra- or intra-articular resection of a primary or secondary bone tumor in the knee area followed by reconstruction with a rotating hinge knee system between 2009 and 2021 were eligible for this study. The primary outcome was the ability to actively lock the operated knee. The secondary outcomes were the concentric PT during isokinetic testing at slow (90°/sec) and fast (180°/sec) speeds, flexion-extension ROM, Musculoskeletal Tumor Society (MSTS) score, the IKS, Oxford Knee Score (OKS) and KOOS.

RESULTS

Nine patients agreed to participate in the study, all of whom had regained the ability to lock their knee postoperatively. PT in flexion and extension on the operated knee was less than the healthy knee. The PT ratio for the operated/healthy knee at 60°/sec and 180°/sec in flexion was 56.3%±16.2 [23.2-80.1] and 57.8%±12.3 [37.7-77.4], respectively, which corresponded to a slow-speed strength deficit of 43.7% in the knee flexors. The PT ratio for the operated/healthy knee at 60°/sec and 180°/sec in extension was 34.3%±24.6 [8.6-76.5] and 43%±27.2 [13.1-93.4], respectively, which corresponded to a slow-speed strength deficit of 65.7% in the knee extensors. The mean MSTS was 70%±20 [63-86]. The OKS was 29.9/48±11 [15-45], the mean IKS knee was 149.6±36 [80-178] and the mean KOOS was 67.43±18.5 [35-88.7].

DISCUSSION

Despite all patients having the ability to lock out their knee, there was an imbalance in the strength between opposite muscle groups: 43.7% strength deficit at slow-speed and 42.2% at fast speed for the hamstring muscles, and 65.7% at slow-speed and 57% at fast speed for the quadriceps muscles. This difference is considered pathological with an increased risk of knee injury. Despite this strength deficit, this joint replacement technique, which is free of complications, can preserve good knee function with acceptable knee joint ROM and satisfactory quality of life.

LEVEL OF EVIDENCE

III; prospective cross-sectional case-control study.

Management of sarcoma recurrence after megaprosthesis of the knee

BACKGROUND

The management of local sarcoma recurrence about the knee (at the distal femur or proximal tibia) is challenging. The objective of this study was to describe the locations of local sarcoma recurrences about knee megaprostheses, the treatments used for each type of recurrence, and the outcomes according to the treatment used.

HYPOTHESIS

The strategy for treating a local sarcoma recurrence about the knee must be based on the topography of tumour involvement.

MATERIALS AND METHODS

We included 13 patients who had local sarcoma recurrence about a knee megaprosthesis and were followed up for at least 2 years. The diagnosis was osteosarcoma in 10 patients and chondrosarcoma in 3 patients. The distal femur was involved in 11 patients and the proximal tibia in 2 patients. We classified the patients into two groups based on whether the tumour involved important structures or was at a distance within the soft tissues.

RESULTS

The recurrence was a nodule at a distance of important structures in 8 (57%) patients, in whom the mean time to recurrence was 15 months (range, 2-34 months). The remaining 5 (38.5%) patients had involvement of important structures in the popliteal fossa and a mean time to recurrence of 42 months (range, 16-80 months). Surgery was performed in 10 patients; the other 3 patients received palliative care due to rapid metastatic dissemination. Of the 6 patients who had surgery for a recurrence at a distance from important structures, 5 (83.3%) underwent isolated tumour resection with the goal of salvaging the limb and 1 (16.7%) underwent transfemoral amputation. Transfemoral amputation was performed in all 3 patients who had surgery for popliteal recurrences. Lung metastases were detected in 10 (77%) patients, 2 at the time of initial sarcoma diagnosis and 8 at the time of the local recurrence. At last follow-up, 5 patients were alive, including 2 (33.3%) of the 6 patients with recurrences at a distance from important structures and all 3 patients with popliteal recurrences. Of the 5 survivors at last follow-up, 2 had metastases.

CONCLUSION

In patients with local recurrence of knee sarcoma, three presentations can be distinguished. When the local recurrence coincides with distant recurrence, failure to control the disease is likely and the local treatment should be designed as a component of palliative care. When no metastases are detected but the local recurrence is in contact with important structures, amputation is advisable at present given the complexity of limb-salvage surgery and high risk of further local recurrence. Finally, when no metastases are detected and the local recurrence is at a distance from important structures, limb-salvage surgery deserves consideration.

LEVEL OF EVIDENCE

IV, retrospective observational study.

Outcomes of Cemented Distal Femoral Replacement Using "Line to Line" Technique With All-Polyethylene Tibial Implant for Tumors

BACKGROUND

Both cemented and cementless stemmed endoprosthetic implants have been used to reconstruct large skeletal defects after tumor resection with similar outcomes. In this study, we examined the oncologic, clinical, and functional outcomes in patients undergoing distal femur replacement using the French paradox technique.

METHODS

A total of 125 patients who underwent distal femur replacement between 1990 and 2019 using the line-to-line cementation technique were reviewed. Implant failure was recorded as per Henderson's classification. Functional outcomes were analyzed using the Musculoskeletal Tumor Society and Toronto Extremity Salvage Score scoring systems. The mean follow-up was 84 (1-350) months.

RESULTS

Aseptic loosening of the femoral stem was recorded in one patient at 21-years of follow-up. Twenty of 125 patients required bushing exchange for polyethylene wear, all after 10 years. Six tibial bearing component fractures were recorded in four patients while one femoral stem component Morse taper fractured. Two all-polyethylene cemented tibial implants were revised for polyethylene granuloma. Deep surgical site infection occurred in 13 patients, while six patients experienced local recurrence. Kaplan-Meier estimates for implant survival for all-cause revision were 85% at 1 year and 70% at 5 years. These estimates for femur or tibia loosening as an end point were 96% at 10 years and 90% at 15 years. The mean Musculoskeletal Tumor Society and Toronto Extremity Salvage Score scores at the last follow-up were 76% and 74%, respectively. Thirty-five patients died of disease progression.

CONCLUSION

The line-to-line cementation technique, used with all-polyethylene tibial implants, demonstrates low incidence of aseptic loosening at medium and long-term follow-ups.

LEVEL OF EVIDENCE

III.

Distal femoral impaction bone grafting in revision for tumor endoprosthesis

BACKGROUND

Reconstruction using tumor endoprosthesis has been widely used in cases with large bone defects caused by bone and soft tissue tumor resection of the distal femur which extend into the knee joint. However, reconstruction failure can lead to major problems in the long term. We have been performing impaction bone grafting with allogeneic cancellous bone during revision surgery for tumor endoprosthesis of the distal femur to compensate for the thinness and fragility of the remaining femur. The aim of this study is to examine the surgical method, problems, and clinical outcomes of revision surgery with impaction bone grafting.

METHODS

Three patients who underwent revision surgery for tumor endoprosthesis using impaction bone grafting at our institution with more than 2 years of follow-up were included.

RESULTS

Union between the graft and host bone were achieved in all cases. The mean time to radiographic union was 1.0 year (0.6-1.5 years). Although intraoperative penetration to the anterior cortex of the distal femur occurred in 2 cases, there were no postoperative fractures. There were no failures of tumor endoprosthesis at final observation.

CONCLUSION

Good short-term results were observed in 3 patients who underwent revision tumor endoprosthesis with impaction bone grafting following a bone and soft tissue tumor resection of the distal femur. The method was considered to be a useful treatment option. Impaction bone grafting is an established surgical option that can be applied to revision surgery for tumor endoprosthesis.