Restoration of Spinopelvic Continuity with the Free Fibula Flap after Limb-Sparing Oncologic Resection Is Associated with a High Union Rate and Superior Functional Outcomes

Reconstruction of Internal Hemipelvectomy Defects After Oncologic Resection

Internal hemipelvectomy is preferred to hindquarter amputation for pelvic tumor resection if a functional lower extremity can be obtained without compromising oncologic principles; multidisciplinary advances in orthopaedic and plastic surgery reconstruction have made this possible. The goals of skeletal reconstruction are restoration of pelvic and spinopelvic skeletal continuity, maintenance of limb length, and creation of a functional hip joint. The goals of soft-tissue reconstruction are stable coverage of skeletal, prosthetic, and neurovascular structures, elimination of dead space, and prevention of herniation. Pelvic resections are divided into four types: type I (ilium), type II (acetabulum), type III (ischiopubic rami), and type IV (sacrum). Type I and IV resections resulting in pelvic discontinuity are often reconstructed with vascularized bone flaps and instrumentation. Type II resections, which traditionally result in the greatest functional morbidity, are often reconstructed with hip transposition, allograft, prosthesis, and allograft-prosthetic composites. Type III resections require soft-tissue repair, sometimes with flaps and mesh, but generally no skeletal reconstruction. Extension of resection into the sacrum can result in additional skeletal instability, neurologic deficit, and soft-tissue insufficiency, necessitating a robust reconstructive strategy. Internal hemipelvectomy creates complex deficits that often require advanced multidisciplinary reconstructions to optimize outcomes and minimize complications.

Is 3D-printed self-stabilizing endoprosthesis reconstruction without supplemental fixation following total sacrectomy a viable approach for sacral tumours?

PURPOSE

The spinopelvic reconstruction poses significant challenges following total sacrectomy in patients with malignant or aggressive benign bone tumours encompassing the entire sacrum. In this study, we aim to assess the functional outcomes and complications of an integrated 3D-printed sacral endoprostheses featuring a self-stabilizing design, eliminating the requirement for supplemental fixation.

METHODS

We retrospectively analyzed patients with sacral tumours who underwent total sacrectomy followed by reconstruction with 3D-printed self-stabilizing endoprosthesis. Clinically, we evaluated functional outcomes using the 1993 version of the musculoskeletal tumour society (MSTS-93) score. Perioperative and postoperative complications were also documented.

RESULTS

10 patients met final inclusion criteria. The median age was 49 years (range, 31-64 years). The median follow-up time was 26.5 months (range, 15-47 months). Median postoperative functional MSTS-93 was 22.5 (range, 13-25). The median operation time was 399.5 min (305-576 min), and the median intraoperative blood loss was and 3200 ml (2400-7800 ml). Complications include wound dehiscence in one patient, bowel, bladder, and sexual dysfunction in four patients, cerebrospinal fluid leak in one patient, and tumour recurrence in one patient. There were no mechanical complications related to the endoprosthesis at the last follow-up.

CONCLUSION

The utilization of 3D-printed self-stabilizing endoprosthesis proved to be a viable approach, yielding satisfactory short-term outcomes in patients undergoing total sacral reconstruction without supplemental fixation.

Lumbopelvic shortening and local host bone-to-host bone reconstruction: a surgical method for lumbopelvic fusion following total sacrectomy

PURPOSE

Primary sacral tumors are rare, representing fewer than 7% of spinal neoplasms. Following total sacrectomy, lumbopelvic instrumentation and fusion carries a high risk of non-union with no current consensus on fixation techniques to augment bony defects. We aim to describe the outcome of a reconstruction technique following total sacrectomy whereby lumbopelvic shortening is performed and the posterior pelvic ring is compressed to enable contact with the native L5 vertebra.

METHODS

Retrospective chart review of 2 patients with 2 and 7 years post-operative follow-up. A review of hospital records including clinical assessments, complications, pathology and imaging reports.

RESULTS

Patient 1 was a 17-years-old male with recurrent sacral chondrosarcoma, who presented with lumbosacral neuropathic pain and radiculopathy after failed intralesional surgery. Patient 2 was a 51-years-old male with chronic low back pain caused by a large low-grade chondroid sacral chordoma. Reconstruction technique involved mobilizing the L5 vertebra into the pelvis and pelvic ring closure to obtain host-bone-to-bone contact, eliminating the need for alternative grafts. Post-operative complications included superficial abdominal wound drainage, lower limb DVT, pulmonary emboli and deep pelvic infection. Serial CT scans demonstrated bony fusion in both patients. Neither patients had evidence of tumor recurrence and were able to ambulate at recent follow-up. Imaging demonstrated changed acetabular version of - 4.6/- 8.1 and - 14.4/- 14.8 (patient 1/2, R/L, respectively).

CONCLUSION

Primary lumbopelvic shortening represents an alternative local autograft reconstructive technique for management of large sacral defects following total sacrectomy. This technique obviates the additional morbidity and surgical cost associated with the use of previously described techniques.

Pelvic ring reconstruction with double-barreled fibular free flap: A systematic review

INTRODUCTION

Pelvic ring reconstruction after internal hemipelvectomy is an extremely challenging surgical procedure, and mandatory reconstruction is to provide a durable and pain-free functional outcome, especially for young, active patients. One of the most widely employed techniques is reconstruction with a double-barreled fibular free flap (DBF). The aim of our work was an in-depth analysis of the outcome of pelvic ring reconstruction performed using the above-mentioned method, in particular looking for a correlation between the fixation technique and either ambulation status or complications.

MATERIALS AND METHODS

A systematic review was performed in November 2020 using PubMed and MedLine Ovid databases according to the PRISMA guidelines and the results were statistically analyzed.

RESULTS

Studies were published between 1994 and 2015. A DBF was used in each case, with a total of 30 patients. Reconstruction was performed with screws in 13 cases, Cotrel-Dubousset rod fixation in 6, screws and plate in 5, screws with external fixation in 4, and ISOLA in 2. Follow-up time ranged from 3 to 131 months. Functional outcome was excellent in 4 patients and good in 26 patients. Statistical analysis showed no statistical evidence of existing correlation between fixation technique and complications (p = .873), while statistical correlation between age and fixation technique was found (p < .001).

CONCLUSION

Reconstruction of pelvic ring with DBF provides an overall good functional outcome. Our data indicate that there is no statistical evidence of existing correlation between the fixation technique and either complications or ambulation status.

Comparison of free vascularized fibular flaps and allograft fibular strut grafts to supplement spinopelvic reconstruction for sacral malignancies

AIMS

Orthopaedic and reconstructive surgeons are faced with large defects after the resection of malignant tumours of the sacrum. Spinopelvic reconstruction is advocated for resections above the level of the S1 neural foramina or involving the sacroiliac joint. Fixation may be augmented with either free vascularized fibular flaps (FVFs) or allograft fibular struts (AFSs) in a cathedral style. However, there are no studies comparing these reconstructive techniques.

METHODS

We reviewed 44 patients (23 female, 21 male) with a mean age of 40 years (SD 17), who underwent en bloc sacrectomy for a malignant tumour of the sacrum with a reconstruction using a total (n = 20), subtotal (n = 2), or hemicathedral (n = 25) technique. The reconstructions were supplemented with a FVF in 25 patients (57%) and an AFS in 19 patients (43%). The mean length of the strut graft was 13 cm (SD 4). The mean follow-up was seven years (SD 5).

RESULTS

There was no difference in the mean age, sex, length of graft, size of the tumour, or the proportion of patients with a history of treatment with radiotherapy in the two groups. Reconstruction using an AFS was associated with nonunion (odds ratio 7.464 (95% confidence interval (CI) 1.77 to 31.36); p = 0.007) and a significantly longer mean time to union (12 months (SD 3) vs eight (SD 3); p = 0.001) compared with a reconstruction using a FVF. Revision for a pseudoarthrosis was more likely to occur in the AFS group compared with the FVF group (hazard ratio 3.84 (95% CI 0.74 to 19.80); p = 0.109); however, this was not significant. Following the procedure, 32 patients (78%) were mobile with a mean Musculoskeletal Tumor Society Score 93 of 52% (SD 24%). There was a significantly higher mean score in patients reconstructed with a FVF compared with an AFS (62% vs 42%; p = 0.003).

CONCLUSION

Supplementation of spinopelvic reconstruction with a FVF was associated with a shorter time to union and a trend towards a reduced risk of hardware failure secondary to nonunion compared with reconstruction using an AFS. Spinopelvic fixation supplemented with a FVF is our preferred technique for reconstruction following resection of a sacral tumour. Cite this article: Bone Joint J 2021;103-B(8):1414-1420.