Role of Resorbable polylactide membrane for treatment of segmental bone defects

USA: Segmental bone defects are a challenging clinical problem. Synthetic membranes have emerged as an option for the treatment of critical bone defects, as these require only one procedure. In animal studies and craniomaxillofacial surgery, resorbable polylactide membrane (OrthoMesh; DePuy Synthes, West Chester, PA) shows promise for treatment of bone defects. This study by N.J.Nahma et al presents the results of the treatment of segmental bone defects with resorbable polylactide membrane, bone morphogenic protein-2 (BMP-2), and autograft.

The goal of the synthetic membranes is to contain bone graft, preserve the intramedullary space, offer structural integrity, and exclude intrusion of non-osseous tissue into the bony defect. Resorbable polylactide membrane is composed of 85:15 poly (L-lactide-co-glycolide).It is a meshed, double-layered construct that is available in 5 cm × 5 cm or 10 cm × 10 cm sheets. It has been approved by the Food and Drug Administration in 2008.These sheets can be cut to size intraoperatively and rolled into appropriate size to fill a bone defect. The meshed feature facilitates vascular ingrowth, and the membrane is bioresorbable, thereby avoiding repeat surgery for explantation.

This study was approved by the institutional review board. All patients with a segmental bone defect treated with a resorbable polylactide membrane by a single surgeon from 2010 to 2019 were retrospectively reviewed. Data related to demographic variables, surgical details, and union were collected.

At the time of resorbable polylactide membrane reconstruction, the bone defect was subperiosteally exposed. Autograft was obtained, typically through the Reamer/Irrigator/Aspirator system. The bone graft was mixed with bone morphogenic protein-2 (BMP-2) .The resorbable polylactide membrane was then cut to size and place. The bone graft and BMP-2 were then inserted into the membrane, and the membrane ends were sutured together, creating a bone graft cage. The proximal and distal ends of the membrane were secured to the bone ends with screws.

Results:

 Eleven patients with median age of 37 years (range 22–62 years) were included in the study with segmental bone defects in the tibia (n = 3), femur (n = 4), or forearm (n = 4).

 Median bone defect size was 6 cm (range 3–12 cm).

 Etiology of bone defects included osteomyelitis (n = 7), oncologic resection (n = 3), and post-traumatic aseptic non-union (n = 1).

 Flap coverage was performed in two patients.

 Median radiographic follow-up was 24 months (range 5–75 months).

 Ten patients (10/11) achieved union at a median of 17 months (range 5–46 months).

 Seven patients required reoperation for any reason with six patients requiring repeat grafting.

The authors concluded that this study is the largest series of patients with segmental bone defects treated with resorbable polylactide membrane. Resorbable polylactide membrane in combination with BMP-2 and autograft represents a safe and effective method of bone graft containment in segmental bone defects measuring up to 12 cm in this series. Ten of 11 patients achieved union at a median time of 16 months with 6 patients requiring repeat grafting. These results compare favourably with the induced membrane technique. This study is limited by its retrospective design, absence of control and comparison groups, and low patient numbers. Future prospective randomized study of the induced membrane technique and resorbable polylactide membrane should be undertaken to determine preferred approaches for treatment of segmental bone defects.

Further reading:

Resorbable polylactide membrane for the treatment of segmental bone defects

Nickolas J. Nahma, Janet D. Conway

Injury 53 (2022) 376–380

https://doi.org/10.1016/j.injury.2021.11.024