The use of Ligament Advanced Reinforcement System (LARS) in limb salvage surgery: a pilot clinical study

Synthetic Ligament-Assisted Functional Soft-Tissue Reconstruction in Tumor-Related Proximal Femoral Replacements

BACKGROUND

Soft-tissue functional reconstruction is important for restoring hip function in proximal femoral replacement for tumor resection. This study evaluated the functional outcome and postoperative complications of a specific synthetic ligament for soft-tissue functional reconstruction in proximal femoral replacement for tumor resection.

METHODS

This cohort included 80 patients (40 men and 40 women, mean age, 40 years (range, 10 to 79)) who had benign invasive tumors (n = 13), primary malignant bone tumors (n = 40), or bone metastases (n = 27). Patients' medical records, imaging files, surgical details, and postoperative pathological diagnoses were collected. Tumor staging was performed with the Enneking staging criteria. Lower limb and hip functions were assessed using the Musculoskeletal Tumor Society scoring system and Harris Hip score, respectively.

RESULTS

Mean postoperative Musculoskeletal Tumor Society and Harris Hip scores were 27 (range, 24 to 30) and 90 (range, 76 to 97), respectively, indicating satisfactory range of motion and stability. Trendelenburg gait was observed in 3 osteosarcoma patients (3.8%), and 6 patients showed unequal lower-limb lengths. Reoperations occurred in 5 cases, including 3 cases of deep vein thromboses and 1 case each of giant cell granuloma and periprosthetic infection. There were 27 patients who had bone metastases who did not require reoperation.

CONCLUSIONS

The synthetic ligament reconstruction of the hip with proximal femoral replacement for tumor resection was associated with improved outcomes. Its implementation exhibits the potential to reduce postoperative incidences of hip dislocation and periprostheses infection, thereby warranting its prospective clinical application.

Use of LARS for soft tissue function reconstruction during tumor-type hemi-shoulder replacement achieves a good prognosis: a retrospective cohort study

BACKGROUND

Shoulder soft tissue function reconstruction during tumor-type hemishoulder replacement is an important step to restore shoulder function. This study evaluates the functional prognosis and postoperative complications of ligament advanced reinforcement system (LARS)-assisted soft tissue functional reconstruction in tumor-type hemi-shoulder replacement.

MATERIALS AND METHODS

Twenty-two patients with an average age of 37.5 ± 17.8 years diagnosed with benign invasive tumors, primary malignant bone tumors, or bone metastases were enrolled in this study. The patient's medical records (history and surgical details), histological sections, imaging files, oncological prognosis, functional prognosis, and postoperative complications were collected. The upper limb function and shoulder joint function were evaluated using the Musculoskeletal Tumor Society (MSTS) system and American Shoulder and Elbow Surgeons (ASES) scoring criteria, respectively.

RESULTS

Twenty-two patients comprising 12 males and 10 females were enrolled. Overall, 9 patients had preoperative pathological fractures. The mean lesion length was 8.6 ± 3.0 cm. The local recurrence was observed in 3 cases, including 2 cases of osteosarcoma and 1 case of MGCT. A further 4 cases had pulmonary metastasis, including 2 cases with local tumor recurrence. The average postoperative MSTS score was 25.8 ± 1.7, and the score of postoperative ASES was 85.7 ± 6.0, both of which showed satisfactory functional recovery. Two cases experienced postoperative complications requiring surgical intervention, including one periprosthetic fracture and one giant cell granuloma. Prosthesis dislocation occurred in 1 case. None of the cases of periprosthetic infection or postoperative complications resulted in implant failure.

CONCLUSIONS

LARS-assisted soft tissue function reconstruction in benign and malignant proximal humerus tumors after a tumor-type hemi-shoulder replacement is an effective technical improvement, which can effectively repair the integrity of the joint capsule to restore joint stability, provide a medium for soft tissue attachment to rebuild the muscular dynamic system, and eliminate residual dead space around the prosthesis, effectively improving limb function and reduce postoperative infection complications.

[Application of LARS ligament combined with three-dimensional printed prosthesis in reconstruction of radial hemicarpal joint after tumor resection]

OBJECTIVE

To investigate the effectiveness of LARS ligament and three-dimensional (3D) printed prosthesis on the combined reconstruction of radial hemicarpal joint after distal radius tumor resection.

METHODS

The clinical data of 12 patients with combined reconstruction of radial hemicarpal joint with LARS ligament and 3D printed prosthesis after distal radius tumor resection between September 2017 and March 2021 were retrospectively analyzed. There were 7 males and 5 females with an average age of 41.8 years (range, 19-63 years). There were 8 cases on the left side and 4 cases on the right side, and 10 cases of giant cell tumor of bone and 2 cases of osteosarcoma. The disease duration ranged from 1 to 20 months, with an average of 8.1 months. The osteotomy length, operation time, and intraoperative blood loss were recorded, and the wrist function was evaluated by Mayo wrist score and Musculoskeletal Tumor Society (MSTS) score before and after operation. The grip strength of the affected limb was expressed by the percentage of grip strength of the healthy upper limb, and the range of motion (ROM) of the wrist joint was measured, including extension, flexion, radial deviation, and ulnar deviation; the bone ingrowth and osseointegration at the bone-prosthesis interface of the wrist joint were observed by radiographic follow-up; the possible wrist complications were recorded.

RESULTS

All 12 patients successfully completed the operation. The osteotomy length was 5.0-10.5 cm (mean, 6.8 cm), and the operation time was 180-250 minutes (mean, 213.8 minutes). The intraoperative blood loss was 30-150 mL (mean, 61.7 mL). All patients were followed up 11-52 months (mean, 30.8 months). Radiographic follow-up showed that bone ingrowth and osseointegration at the bone-prosthesis interface were observed in all patients, and biological fixation was gradually achieved. During the follow-up, the stability, motor function, and ROM of the wrist joint were good. There was no complication such as arthritis, subluxation, prosthesis loosening, and infection, and no tumor recurrence and metastasis. At last follow-up, the Mayo score was 82.1±5.4, and MSTS score was 27.5±1.5, which were significantly improved when compared with those before operation (48.8±13.5, 16.4±1.4; t=-10.761, P<0.001; t=-26.600, P<0.001). The grip strength of the affected side was 59%-88% of that of the healthy side, with an average of 70.5%. The ROM of wrist joint were 55°-80° (mean, 65.42°) in extension, 35°-60° (mean, 44.58°) in flexion, 10°-25° (mean, 17.92°) in radial deviation, 10°-25° (mean, 18.33°) in ulnar deviation.

CONCLUSION

The combined application of LARS ligament and 3D printed prosthesis is an effective way to reconstruct bone and joint defects after distal radius tumor resection. It can improve the function of wrist joint, reduce the incidence of complications, and improve the stability of wrist joint.

Limb Salvage Using Non-hinged Endoprosthesis and Staged Correction of Leg-length Discrepancy for Children with Distal Femoral Malignant Tumors

OBJECTIVE

Limb salvage in pediatric patients remains a challenge. We describe a staged strategy. The procedure includes: (i) tumor removal and non-hinged static endoprosthesis reconstruction; (ii) leg length discrepancy (LLD) correction by shoe lift or distraction osteogenesis; and (iii) maturity reconstruction by regular endoprosthesis. The aim of the study was to investigate the results of non-hinged static megaprosthesis reconstruction and staged LLD correction in the treatment of malignant tumors in the distal femur in children.

METHODS

Non-hinged megaprostheses were implanted in 12 pediatric patients with osteosarcoma in the distal femur. The prosthesis consists of a femoral component with constrained condylar knee (CCK) design, and a tibial component with a small-diameter press-fit stem and derotation fins. A posterior stabilizing polyethylene component is fixed on the tibial component. The cases were prospectively followed up with focus on the growth rate of adjacent uninvolved bone in the salvaged limb, joint stability, knee stability, function outcome, length discrepancy, and surgery-related complications.

RESULTS

There were five girls and seven boys included in the study, with an average age at the time of primary surgery of 10.0 years (range, 8-12 years). All the tumors were located in the distal femur. The average follow up was 76.3 months (range, 24-139 months). The Ligament Augmentation and Reconstruction System (LARS) ligament was used in two patients to enhance the soft tissue reattachment and reconstruct medial collateral ligament (MCL). Ten patients were alive at the final follow-up and two had died of lung metastases. Expected LLD was 6.7 cm (range, 3.0-13.2 cm) at initial surgery. At the final follow-up, nine patients reached skeletal maturity and the actual LLD at the femur was 5.3 cm (range, 3.0-10.1 cm), excluding 1 cm correction at initial surgery by endoprosthesis. The proximal tibia physis showed an average of 86.7% (range, 56.5%-100%) growth of the contralateral side. The mean reduction in tibial length was 1.2 cm (range, 0.5-4.7 cm). Six patients received distraction osteogenesis at a mean length of 5.4 cm (range, 3.0-9.1 cm). Range of knee movement was between 85° and 125°, with an average of 102.5°. The Musculoskeletal Tumor Society 93 score of patients alive was 80.6 (range, 60-90).

CONCLUSION

Non-hinged static megaprosthesis followed by LLD correction with shoe lift or staged distraction osteogenesis appears to be an alternative option to treat children with malignant bone tumors around the knee.

Surgical and Functional Outcomes After Limb-Preservation Surgery for Tumor in Pediatric Patients: A Systematic Review

BACKGROUND

Limb-salvage surgery and segmental reconstruction for the treatment of lower extremity osseous tumors in the pediatric population have been described in the literature, but there is little consensus regarding the optimal surgical treatment for this patient population.

METHODS

A systematic review of the literature was performed to identify studies focusing on limb-salvage procedures in pediatric patients who were managed with one of three reconstructions with use of a metallic endoprosthesis, allograft, or allograft-prosthesis composite. Data were segregated according to the excised and reconstructed anatomical location (proximal part of the femur, total femur, distal part of the femur, proximal part of the tibia) and were collated to assess modes of failure and functional outcomes of each reconstruction type for each anatomic location.

RESULTS

Sixty articles met the inclusion criteria; all were Level-IV evidence, primarily consisting of small, retrospective case series. Infection was a primary mode of failure across all reconstruction types and locations, whereas allograft reconstructions were susceptible to structural failure as well. The rate of failure in the pediatric population correlated well with previously published results for adults. The incidence of subsequent amputation was lower in the pediatric population (5.2%) than has been reported in adults (9.5%) (p = 0.013). Meaningful growth of expandable metallic endoprostheses was reported in the literature, with an overall rate of leg-length discrepancy of 13.4% being noted at the time of the latest follow-up. The Musculoskeletal Tumor Society (MSTS) questionnaire was the most consistently used outcome measure in the literature, with average scores ranging from 71.0% to 86.8%, depending on reconstruction type and anatomic location.

CONCLUSIONS

The current state of the literature detailing the surgical and functional outcomes of segmental reconstruction for the treatment of pediatric bone tumors is limited to Level-IV evidence and is complicated by under-segregation of the data by age and anatomical location of the reconstruction. Despite these limitations, pediatric limb-salvage surgery demonstrates satisfactory initial surgical and functional outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Megaprosthesis versus Allograft Prosthesis Composite for massive skeletal defects

Massive skeletal defects are encountered in the setting of tumors necessitating excision, failed total hip arthroplasty with periprosthetic bone loss, periprosthetic fracture, complex trauma, multiple failed osteosynthesis and infection. Reconstruction of the segmental defects poses a tremendous challenge to the orthopaedic surgeons. The goal of osseous reconstruction of these defects is to restore the bone length and function. Currently the most commonly employed methods for reconstruction are either a megaprosthesis or an Allograft Prosthesis Composite (APC). Megaprosthesis, initially created for the treatment in neoplastic pathologies are being used for the non-neoplastic pathologies as well. The longevity of these implants is an issue as majority of the patients receiving them are the survivors of oncologic issue or elderly population, both in which the life expectancy is limited. However, the early complications like instability, infection, prosthetic breakage and fixation failure have been extensively reported in several literatures. Moreover, the megaprostheses are non-biological options preventing secure fixation of the soft tissue around the implant. The Allograft Prosthesis Composites were introduced to overcome the complications of megaprosthesis. APC is made of a revision-type prosthesis cemented into the skeletal allograft to which the remaining soft tissue sleeve can be biologically fixed. APCs are preferred in young and low risk patients. Though the incidence of instability is relatively low with the composites as compared to the megaprosthesis, apart from infection, the newer complications pertaining to APCs are inevitable that includes non-union, allograft resorption, periprosthetic fracture and potential risk of disease transmission. The current review aims to give an overview on the treatment outcomes, complications and survival of both the megaprostheses and APCs at different anatomic sites in both the upper and lower limbs.

Use of Ligament Advanced Reinforcement System tube in stabilization of proximal humeral endoprostheses

AIM: To review outcomes following usage of the Ligament Advanced Reinforcement System (LARS^®) in shoulder tumors.

METHODS: Medical records of nineteen patients (19 shoulders) that underwent tumor excisional procedure and reconstruction with the LARS synthetic fabric, were retrospectively reviewed.

RESULTS: Patients’ median age was 58 years old, while the median length of resection was 110 mm (range 60-210 mm). Compared to immediate post-operative radiographs, the prosthesis mean end-point position migrated superiorly at a mean follow up period of 26 mo (P = 0.002). No statistical significant correlations between the prosthesis head size (P = 0.87); the implant stem body length (P = 0.949); and the length of resection (P = 0.125) with the position of the head, were found at last follow up. Two cases of radiological dislocation were noted but only one was clinically symptomatic. A minor superficial wound dehiscence, healed without surgery, occurred. There was no evidence of aseptic loosening either, and no prosthetic failure.

CONCLUSION: LARS^® use ensured stability of the shoulder following endoprosthetic reconstruction in most patients.