A.-C. Masquelet

The concept of induced membrane for reconstruction of long bone defects.

Clinical, experimental, and fundamental studies have shown the interest of a foreign body-induced membrane to promote the consolidation of a conventional cancellous bone autograft for reconstruction of long bone defects. The main properties of the membrane are to prevent the resorption of the graft and to secrete growth factors. The induced membrane appears as a biological chamber, which allows the conception of numerous experimental models of bone reconstruction. This concept could probably be extended to other tissue repair.

Clinical, Quantitative Assessment of First Tarsometatarsal Mobility in the Sagittal Plane and Its Relation to Hallux Valgus Deformity

Today, bunion surgery is still controversial. Considering that a bunion deformity in fact may be a result of multiple causes, the rationale of the currently applied techniques of surgical treatment has not been conclusively demonstrated. In view of the known hypermobility syndrome of the first ray that results in insufficient weightbearing beneath the first metatarsal head, the relationship between this syndrome and hallux valgus deformity has been investigated. The results suggest a direct relationship between painful hallux valgus deformity and hypermobility in extension of the first tarsometatarsal joint. A pathological mechanism of symptomatic hallux valgus is proposed that relates this pathology with primary weightbearing disturbances in the forefoot where angulation of the first metatarsophalangeal joint is one of the consequences. The alignment of the metatarsal heads within the sagittal plane seems to be a main concern in many hallux valgus deformities. As a consequence, treatment includes reestablishing stable sagittal alignment in addition to the horizontal reposition of the metatarsal over the sesamoid complex. As an example, first tarsometatarsal reorientation arthrodesis regulates the elasticity of the multiarticular first ray within the sagittal plane and may be the treatment of choice in many hallux valgus deformities.

Treatment of posttraumatic bone defects by the induced membrane technique.

INTRODUCTION Among bone reconstruction techniques, the induced membrane technique, proposed in 1986 by Masquelet, has rarely been studied or evaluated in the surgical literature until recently. The 2010 French Society of Orthopaedic Surgery and Traumatology (SoFCOT) Annual Convention symposium was the occasion to evaluate a large cases series having used this technique. PATIENTS AND METHODS This retrospective study included 84 posttraumatic diaphyseal long bone reconstructions using the induced membrane technique (1988-2009). The series included 79 men and five women (mean age 32-year-old). In 89% of cases, the initial trauma was an open fracture. The leg was involved in 70% of cases. The mean delay between the accident and treatment of bone defects (BD) was 8 months. In 50% of the cases, infection was present. Bone defects were larger than 5cm in 57% of the cases. RESULTS Union was obtained in 90% of cases, a mean 14.4 months after the first stage of the reconstruction. A mean 6.11 interventions were necessary to obtain union. Malalignment was present in 17% of cases. Delayed interventions to correct deformities mostly of the foot were necessary in 16% of the cases. Eight failures (10%) involved severe leg traumas associating extensive bone defects, soft tissue lesions and infection and required amputation in six cases. DISCUSSION This series emphasizes the severity of open fractures of the leg, especially those with primary or secondary infection. The induced membrane technique has been shown to be effective in treating bone defects, regardless of their magnitude. In a two-step procedure, this simple but demanding technique, which may be more complicated when repair of soft tissue is necessary, provides successful treatment in case of initial infection and fulfills the goal of controlling infection before bone reconstruction. Moreover, the induced membrane technique can be integrated in hybrid reconstruction procedures. LEVEL OF EVIDENCE Level IV. Retrospective study.

Bone transport techniques in posttraumatic bone defects.

INTRODUCTION The treatment of posttraumatic diaphyseal bone defects (BD) calls on a number of techniques including bone transport techniques: isolated shortening, compression-distraction at the fracture site, shortening followed by lengthening in a corticotomy distant from the site and segmental bone transport. PATIENTS AND METHODS The multicenter retrospective study combined 38 cases: 22 cases of initial diaphyseal bone defect and 16 cases of secondary diaphyseal BD, sometimes associated with metaphyseal or metaphyseal-epiphyseal BD, involving the humerus, the forearm, the femur and the tibia. These techniques were mainly used on the lower extremity (33 cases), for the most part on the tibia (22 cases) in young men. RESULTS Bone healing was acquired in 37 cases out of 38 after a mean 14.9 months (range, 6-62 months). A mean 4.3 secondary interventions were required to obtain final union; most notably, a bone graft was necessary at the docking site for the segmental bone transport procedures. DISCUSSION Many reconstruction techniques can be proposed to treat posttraumatic BD. None responds to all situations. Bone transport techniques have their place and their indications. Isolated shortening is intended for bone loss not exceeding 3cm, notably in the humerus and to a lesser degree in the lower extremity. Shortening associated with lengthening is valuable in the femur and the tibia for bone loss up to 6cm. Segmental bone transport is the only technique that can treat bone defects associated with shortening in the lower limb. For substantial bone loss beyond 10cm, segmental bone transport is particularly indicated. However, these cases of substantial bone loss tend to be resolved by a hybridization of the procedures. The distraction gap of a bone segment can, for example, be prepared using an induced-membrane technique. LEVEL OF EVIDENCE Level IV. Retrospective study.

Bone regeneration in long-bone defects: tissue compartmentalisation? In vivo study on bone defects in sheep

Regeneration of living tissue varies with species, age and type of tissue, and undoubtedly with the biological and mechanical environment of the precise tissue. Autologous cancellous bone grafting is a well-known technique that provides bony regeneration. We investigated the efficiency of autologous bone grafting in a well-vascularised muscle environment, and additionally when isolated from the muscle and connected only to the bony environment. We designed a reproducible animal model producing a stable 3cm middiaphyseal bone and periosteal defect on sheep femurs and created a foreign-body membrane with a temporary poly-methylmethacrylate spacer. The foreign-body membrane had the outer dimension of the removed bone segment. We then ascertained the bony regeneration potential within the bone defect using autologous cancellous bone graft. Regeneration of bone is enhanced considerably by an autologous foreign-body membrane that separates the interfragmentary space from the muscular environment. This effect is independent of the autologous bone graft. The results suggest that bone behaves like a compartment that protects its specific humoral or its cellular environment, or both. Regeneration of bone can be enhanced by compartmentalisation of the bone defect.

Anatomic study of the distally based vastus lateralis muscle flap.

The anatomy of the vascular perforation to the distal portions of the vastus lateralis muscle has been studied in 20 cadaver extremities to outline the vascular basis for distally based vastus lateralis muscle flap. From the 15.4 +/- 2.4, 11.8 +/- 1.7, and 7.9 +/- 2.0 cm distally to the patella, three quite large branches that issue from the deep femoral artery with the mean diameter of 2.8 +/- 0.2, 2.6 +/- 0.2, and 2.2 +/- 0.3 mm, respectively, distribute the distal parts of vastus lateralis muscle. These branches are thought to be an anatomic basis for the distally based vastus lateralis muscle flap. This allows the distally based vastus lateralis muscle flap to be raised for coverage of defects (1) in the popliteal fossa posterior and inferior portions of the knee anteriorly, (2) in the proximal one-third of the leg, and (3) for a below-knee amputation and the rotation of muscle tissue, such as when the gastrocnemius and soleus muscle are unavailable.

Experimental Animal Model Proving the Benefit of Primary Defatting of Full-thickness Random-pattern Skin Flaps by Suppressing “perfusion Steal”

Background: The value of primary flap defatting remains unclear. This experimental animal study provides a novel theory on the problem of primary defatting, “steal of perfusion” to the skin by fat. This theory is based on the fact that the fat brings blood supply to the proximal flap portion but blood is sequestered in the fat of the distal flap portion, to the disadvantage of skin perfusion. Methods: Fifteen full-thickness random-pattern skin flaps, with a 3:1 length-to-width ratio, elevated on the necks of pigs and then left in situ on a plastic sheet interposed between the flap and the deep vascularization from the muscle, were compared with 15 identical contralateral flaps, defatted in the distal half. Results: In the 15 nondefatted flaps, necrosis of the distal half of the flap was observed. Among the 15 defatted flaps, no necrosis was observed in four defatted flaps, partial necrosis was seen in five defatted flaps, concentric necrosis in three defatted flaps, partial necrosis in two defatted flaps, and necrosis in one defatted flap. Necrosis in defatted flaps was significantly less than that in nondefatted flaps (25.6 ± 21.8 percent of flap surface versus 50 ± 2.7 percent; p < 0.001). Conclusions: There is a benefit to primary defatting. Perfusion steal exists for pedicular and peripheral vascularization. Primary partial defatting of a random-pattern flap is beneficial for distal perfusion, which is attributed to suppression of perfusion steal. Complete defatting is detrimental to flap survival. The fat is indispensable for perfusion of the proximal flap portion and is paradoxically detrimental for the distal region.

External fixation of the thalamic portion of a fractured calcaneus: a new surgical technique.

The optimal treatment for intra-articular calcaneus fractures remains controversial, despite internal fixation techniques providing good results. The major point of contention is the need to reconstruct the overall morphology versus to restore the anatomy of the subtalar joint perfectly. We will describe a two-stage technique for treating intra-articular calcaneus fractures in which the primary fracture line goes through the thalamic fragment. The first procedure focuses on the overall morphology by restoring the height and length with osteotaxis being accomplished with a medial external fixator. The second procedure consists of internal fixation through a minimally invasive lateral approach to restore the anatomy of the articular facets. Any defects are filled with injectable bone substitute. This novel technique is compared to the complication rates and radiology and anatomy outcomes in published studies. This two-stage surgical technique reduces the length of hospital stays and the number of complications.

A lateral approach to the distal humerus following identification of the cutaneous branches of the radial nerve

We describe a lateral approach to the distal humerus based on initial location of the superficial branches of the radial nerve, the inferior lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm. In 18 upper limbs the superficial branches of the radial nerve were located in the subcutaneous tissue between the triceps and brachioradialis muscles and dissected proximally to their origin from the radial nerve, exposing the shaft of the humerus. The inferior lateral cutaneous nerve of the arm arose from the radial nerve at the lower part of the spiral groove, at a mean of 14.2 cm proximal to the lateral epicondyle. The posterior cutaneous nerve of the forearm arose from the inferior lateral cutaneous nerve at a mean of 6.9 cm (6.0 to 8.1) proximal to the lateral epicondyle and descended vertically along the dorsal aspect of the forearm. The size and constant site of emergence between the triceps and brachioradialis muscles constitute a readily identifiable landmark to explore the radial nerve and expose the humeral shaft.

Principles of soft tissues repair at the foot and ankle

Soft tissue defects at the foot and ankle are a common and difficult problem because of the different features of juxtaposed tissues. One should distinguish several areas which require specific indications of coverage. These are the dorsum of the foot, the perimalleolar zone, the weight bearing area, the posterior aspect of the heel and the distal part of the achilleus tendon. The armamentarium of procedures comprises fascio-cutaneous and muscle flaps. As far as possible, we use island predicled flaps which are quicker, easier and more reliable than free revascularized flaps. Numerous loco regional island flaps are available as the dorsalis pedis, the latero supramalleolar, the medial plantar, the medialis pedis, the extensor digitorum brevis, the abductor hallucis and the peroneus brevis flaps. The coverage of the heel remains an unsolved problem. It seems preferable to employ fascio-cutaneous flaps to restore weight bearing areas. The cross leg flap is a good alternative to a loco regional flap or a free flap to repair the heel entirely. Complications and sequelae are usually due to shear stresses and require a permanent care. The restored sensibility does not seem to prevent the recurrent ulcerations which are provoked by mechanical factors.