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Headless Compression and Twist-Off Screws 

Surgical Technique

Figure 1

Figure 2

The following surgical technique describes a Twist-Off 
Screw being used in a Weil osteotomy. 

Surgical Approach 

A Weil osteotomy is performed using a dorsal approach. 
Incision is initiated within the intermetatarsal space 
and extends to the web space ( Figure 1). Osteotomy 
skin retraction provides exposure of both extensor 
muscles.

Place the lesser metatarsal in plantar flexion to expose 
the metatarsal head and dislocate the joint. Placing 
one Hohmann retractor on each side of the metatarsal 
should make this maneuver much easier. The use 
of a spreader helps to ensure a safe osteotomy by 
providing adequate protection. 

Osteotomy

The osteotomy is made horizontal and parallel to the 
sole. It starts in the cartilage of the head, near the 
dorsal margin, and should be at least 2.5 cm long 
(Figure 2).

Caution:

 The direction of the cut should be adjusted 

according to the condition of the forefoot. In case of 
pes cavus, the cut may be too short and the resection 
level should therefore be raised. In case of pes planus 
(or for the fourth or fifth metatarsals), the cut may be 
too long and the resection level should be lowered. 

Twist-Off Screw Technique

Summary of Contents for Headless Compressionand Twist-Off Screws

Page 1: ...Headless Compression and Twist Off Screws Surgical Technique...

Page 2: ......

Page 3: ...al Applications 4 Osteotomy 4 K Wire Placement 5 Screw Measurement 6 Insertion 7 Drilling Optional 7 Screw Removal 7 Bicortical Osteotomy 8 K Wire Placement 8 Drilling Optional 8 Insertion 9 Screw Rem...

Page 4: ...e 2 5 mm 10 40 mm 2 mm increments 3 0 mm 10 40 mm 2 mm increments Tapered Threads 0 9 mm Cobalt Chrome K Wire T7 Hexalobe Drive Four Cutting Edges TiMAX Titanium 1 8 mm minor diameter designed for inc...

Page 5: ...the dorsal aspect of the first metatarsophalangeal joint just medial and parallel to the EHL tendon The incision is carried down to the subcutaneous tissues Figure 2 Retract the soft tissues carefully...

Page 6: ...t a 0 9 mm k wire perpendicular into the center of the first metatarsal head Figure 3a A medially based long arm Chevron type osteotomy is then created from medial to lateral Remove the k wire The cap...

Page 7: ...4 mm from the depth gauge measurement to avoid penetrating the articular cartilage with the distal tip of the screw For example if the measurement is 20 mm then select the 16 mm screw Tip When using a...

Page 8: ...rew length may vary depending upon the level of obliquity applied to the k wire during insertion To determine the screw length and with the obliquity of the k wire in mind record the measurement Using...

Page 9: ...te The Zimmer Biomet Headless Compression screws are designed to be self drilling and self tapping and may be inserted under power If the bone is deemed to be too hard prior to screw insertion or an o...

Page 10: ...the 2 5 mm Head Relief Drill and for the 3 0 mm screw use the 3 0 mm Head Relief Drill Figure 10 Headless Compression Screw Technique Bicortical Applications Figure 9 K Wire Placement For bi cortical...

Page 11: ...rt the T7 Solid Driver into the head of the screw and turn the Driver counterclockwise until the screw is removed 2 0 x 65 mm Cann Drill Bit AO 110027744 Compatible with the 70 mm and longer k wires 2...

Page 12: ...ements 2 7 mm Screw 8 mm 16 mm 1 mm increments 18 24 mm 2 mm increments Expanded shaft length over previous design for use with pin drivers 3 point head engagement designed for stable driving Cortical...

Page 13: ...t Placing one Hohmann retractor on each side of the metatarsal should make this maneuver much easier The use of a spreader helps to ensure a safe osteotomy by providing adequate protection Osteotomy T...

Page 14: ...at it is sitting flush with the bone The depth gauge displays the measurement from the distal tip of the depth gauge to the top of the k wire Figure 3 Figure 5 Insertion Hold the head against the meta...

Page 15: ...ing the Twist Off Screw in osteoporotic bone stop advancing the screw before the head engages the near cortex Place the mosquito clamp against the screw below the head applying pressure while bending...

Page 16: ...hortening Z shaped release of extensor muscles is often necessary Close the incision Note The 2 0 mm Twist Off Screw is designed with cortical threads while the 2 7 mm Twist Off Screw has cancellous t...

Page 17: ...Sterile Description 110018424 110018425 110018426 110018427 110018428 110018429 110018430 HCS Screw 2 5 x 28 PT HCS Screw 2 5 x 30 PT HCS Screw 2 5 x 32 PT HCS Screw 2 5 x 34 PT HCS Screw 2 5 x 36 PT...

Page 18: ...Twist Off Screw 2 7 x 14 Twist Off Screw 2 7 x 15 Twist Off Screw 2 7 x 16 Twist Off Screw 2 7 x 18 Twist Off Screw 2 7 x 20 Twist Off Screw 2 7 x 22 Twist Off Screw 2 7 x 24 Included in tray Implants...

Page 19: ...hand In the foot these include procedures to correct Hallux Valgus bunions Hallux Varus and Hallux Rigidus Hammer toe Claw toe and Mallet toe CONTRAINDICATIONS 1 Infections 2 Patient conditions includ...

Page 20: ...rbiomet com This technique was prepared in conjunction with a licensed health care professional Zimmer Biomet does not practice medicine and does not recommend any particular orthopedic implant or sur...

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