An ideal osteotomy technique is one that minimizes soft-tissue and periosteal disruption, lessens thermal necrosis, and produces high-quality healing tissue. The old classic method to cut a tibia was defined as a “corticotomy,” a percutaneous subperiosteal cortical osteotomy. This technique, performed with an osteotome, is described for triangular bones such as the tibia, ulna, and radius, and round bones such as the femur and humerus.

Currently, multiple drill-hole and Gigli saw osteotomy are the 2 foremost methods for osteotomy, being favored and recommended by many orthopedic surgeons. The subperiosteal percutaneous Gigli saw osteotomy technique also known as the Afghan technique, is a recognized and popular method for performing osteotomies in long bones, as well as the foot, which preserves the periosteum while completely transecting the endosteum.1–3

To facilitate the bone cut with the Gigli saw, mostly performed by the main surgeon in field, we present the two-man technique, in our view easier and safer for the patient.

SURGICAL TECHNIQUE

The technique is described for high tibial osteotomy fixed with a hexapod external fixation. Two transverse 2 cm incisions are made, one over the anterior tibial crest, the second over the posteromedial border of the bone. Through subperiosteal dissection a suture is passed from the second to the first incision using a right-angled and curved clamp. The Gigli saw is tied to the suture and is pulled from posteromedial to anterolateral. At this stage, 2 surgeons (Figs. 1–3), each grasp with the right hand 1 handle at the end of the saw, while the left hand is grasping a right-angle retractor to protect the skin and muscle, an assistant is holding the external fixator frame, keeping it steady. With reciprocal motion back and forth, keeping a 90-degree angle between the 2 limbs of the saw, cutting initially the posterolateral cortex of the tibia and the medullary canal, then the saw is held horizontally, completing the osteotomy by cutting the medial cortex of the bone. Each surgeon ensuring that the surrounding soft-tissue in their side is protected. Finally, the saw is cut with a wire cutter and removed.1,3,4

FIGURE 1:

The Gigli saw is handled by 2 surgeons—demo on saw-bone model.

FIGURE 2:

The Gigli saw is handled by 2 surgeons—demo in surgery.

FIGURE 3:

X-ray of the cut with Gigli saw.

DISCUSSION

The percutaneous Gigli saw osteotomy technique was first described in the English literature by Paley and Tetsworth5 in 1991. We treated 16 patients in all age group (7 to 65 average 29 y old) with this technique for 20 tibia osteotomies. The patients were treated for several indications (Table 1) and for all cases had no complications.

TABLE 1 - Patients Treated With 2 Men Technique No. Age Side Segment Etiology Indication 1 19 Bil Tibia Adolescent blount Varus knees 2 21 Lt Tibia Adolescent blount Varus knees 3 18 Bil Tibia Achondroplasia Varus knees—instability and short statue 4 7 Lt Tibia Blount disease Varus knee 5 10 Lt Tibia Blount disease Short tibia 6 8 Rt Tibia Fibular hemimelia grade 2 (Paley) Short tibia 7 11 Lt Tibia Russel silver syndrome Short tibia 8 58 Lt Tibia MCOA—medial compartment osteroarthritis Varus tibia 9 51 Rt Tibia MCOA—medial compartment osteroarthritis Varus tibia 10 65 Rt Tibia MCOA—medial compartment osteroarthritis Varus tibia 11 51 Lt Tibia MCOA—medial compartment osteroarthritis Varus tibia 12 15 Lt Tibia Adolescent blount Varus tibia 13 14 Bil Tibia Achodroplasia Varus tibia—instability ~(thrusting) 14 51 Rt Tibia MCOA—medial compartment osteroarthritis Varus tibia 15 58 Rt Tibia MCOA—medial compartment osteroarthritis Varus tibia 16 9 Bil Tibia Achondroplasia Varus tibia—instability 7-65 (29 y) Total 20 Blount disease—5 MCOA—6 Achondroplasia—3 Russel silver syndrome—1 Fibular hemimelia—1

Bil indicates, bilateral; Lt, left; Rt, right.

There are many advantages to the use of the Gigli saw3,5:

Minimally invasive procedure. Minimal soft-tissue dissection required. Eliminates the possibility of an incomplete osteotomy. The transverse orientation of the osteotomy greatly facilitates radiographic verification of the completeness and new regenerate formation at the osteotomy sites. The purely transverse orientation of the cut and its smooth surfaces are of great help when rotational deformities are to be corrected. Even in a relatively short segment more than 1 osteotomy can be performed. The procedure is low-energy, stimulates neovascularization at the regenerate site to a greater extend, in comparison to the other osteotomy types. May also be used with in intramedullary nail in situ. The instrument is routinely available almost everywhere. In high tibial osteotomy in metaphyseal bone, it allows a close bone cut to the apex of the deformity, especially when using a hexapod fixator and gradual correction. Easy to perform when a precise cut is required in small structures, such as the midfoot. There are no butterfly fragments or spiral extensions of the osteotomy The osteotomy can be performed very close to transfixion wires or half-pins, without the risk of extension to the pin sites.

Despite all of the advantages, this osteotomy is not frequently adopted among reconstructive surgeons. This technique should be done very precisely as potential damage to soft-tissue structures around the saw always exists. The bone cut itself is mostly performed by a single surgeon activating the saw, holding the proper handles with its 2 hands. This maneuver is a substantial burden on the surgeon: Standing on the medial side of the tibia, forced to concentrate on the 2 skin cut tissues, the surgeon is dependent on 2 assistants to protect the skin and muscle with a right-angle retractor, and a third one to hold firmly the external fixator. Initially, the 2 ends of the Gigli saw are held at 90-degree to each other while cutting the posterior and lateral cortices of the tibia. However, in order to cut the medial cortex, the angle of the Gigli saw must be flattened, forcing the surgeon to an extreme abduction of the shoulders, in an ergonomically less efficient position, while the elbows and hands should be moved in a reciprocal manner. The final cut of the outer medial cortex is the most challenging part, the surgeon is obliged to grasp the rough wire with his hands close together, to offer more control.3,5

Activating simultaneously the Gigli saw by 2 surgeons, has the following advantages:

The force required to cut the bone is divided between 2 surgeons instead of 1, less energy is required to be applied by each surgeon. Better control is achieved to protect the soft-tissue. Each surgeon is concentrating on a single skin cut instead of 2, avoiding an inadvertent extent of the skin cuts by the saw. The last step of the osteotomy which requires the angle of the Gigli saw to flatten, is much easier when 2 surgeons are holding at each side of the Gigli saw, grasping the proper handle and do not touch the rough saw with the hands. REFERENCES 1. Dabis J, Templeton-Ward O, Lacey AE, et al. The history, evolution and basic science of osteotomy techniques. Strateg Trauma Limb Reconstr. 2017;12:169–180. 2. De Bastiani G, Aldegheri R, Renzi-Brivio L, et al. Limb lengthening by callus distraction (callotasis). J Pediatr Orthop. 1987;7:129–134. 3. Nahm N, Boyce Nichols LR. Percutaneous osteotomies in pediatric deformity correction. Orthop Clin North Am. 2020;51:345–360. 4. Peek AC, Timms A, Chin KF, et al. Patterns of healing: a comparison of two proximal tibial osteotomy techniques. Strateg Trauma Limb Reconstr. 2016;11:59–62. 5. Paley D, Tetsworth K. Percutaneous osteotomies. Osteotome and Gigli saw techniques. Orthop Clin North Am. 1991;22:613–624.