- See:
Synthes Unreamed Tibial Nail: Characteristics:
- Skin Incision and Initial Exposure:
- as noted by Keating et al 1997, 77% of patients who had a mid-patellar tendon splitting incision had significant knee pain;
- in the report by Jarmo A.K. Toivanen, MD, PhD, the authors evaluated anterior knee pain in patients that underwent tibial
IM nailing using either a paratendinous approach versus a transtendinous approach;
- 14 (67%) of the 21 patients treated with transtendinous nailing reported anterior knee pain at the final evaluation;
- 15 (71%) of the 21 patients treated with paratendinous nailing reported anterior knee pain, and ten of the fifteen were impaired by the pain;
- the authors noted that a paratendinous approach for nail insertion does not reduce the prevalence of chronic anterior knee pain or
functional impairment by a clinically relevant amount after IM nailing of a tibial shaft fracture;
- references:
- Knee pain after tibial nailing. JF Keating et al. J. Orthop. Trauma Vol 11. No 1. p 10-13. 1997.
-
Anterior Knee Pain After IM Nailing of Fractures of the Tibial Shaft A Prospective, Randomized Study Comparing Two Different Nail-Insertion Techniques
Jarmo A.K. Toivanen, MD, PhD, The Journal of Bone and Joint Surgery (American) 84:580-585 (2002)
-
Anterior knee pain after IM nailing of frx of tibial shaft: an 8-yr follow-up of prospective, randomized study comparing 2 different nail-insertion techniques.
-
tourniquet:
- may be used during the initial exposure, since bleeding is often frustrating during this exposure;
- tourniquet should never be used during reaming of the canal (risks thermal necrosis);
- references:
The use of a tourniquet when plating tibial fractures.
- incision for midshaft and distal tibial frx:
- midline incision centered over distal pole of the patella down to the tibial tuberlce;
- lateral patellar tendon incision:
- advantages: allows better access to the starting hole position than the medial incision;
- use the knife to split thru the lateral 1/3 of the patellar tendon;
- if necessary, the incision can be carried up proximally along the lateral border of the patellar (which may be required for proximal tibial fractures
inorder to gain entry to the IM canal);
- medial patellar tendon incision:
- disadvantages: access to the starting hole is more difficult that with the lateral incision;
- incise thru the medial 1/3 of the patellar tendon with the knife;
- by splitting thru the medial portion of the patellar tendon (as compared to the medial tendon - retinacular junction), it is easier to
insert the guide pin in the correct central location;
- proximal incision is carried only to deep fascia: knee joint is not entered (the fat pad prevents entry into the joint);
- distal incision is carried down to bone;
- infrapatellar fat pad:
- pushed proximally and posteriorly into knee joint w/ an elevator;
- anterior surface of proximal tibia is exposed;
- periosteum is reflected over a one cm diameter area after incising it with cautery;
- proximal tibial fractures: incision will have to modified;
- as noted by Tornetta 1996, proximal tibial fractures will require an extended medial parapatellar incision inorder to achieve correct entry hole position;
- this will be similar to a
TKR surgical approach:
- utilized an extended medial parapatellar incision, which allow slateral subluxation of the patella, and which allows a more proximal and lateral
starting hole to be achieved;
- by using this extended incision, hyperflexion of the knee was not required inorder to achieve a proximal starting hole and to
keep the reaming parallel to the anterior cortex;
- note that hyperflexion of the knee tends to flex the proximal fragment which sends the nail towards the posterior tibial cortex (which is the biggest pitfall);
- patient is position supine with the leg slightly flexed;
- mid-line incision is made from superior pole of the patella to the tibial tubercle;
- incise thru the medial 1/4 of the patellar tendon and continue this incision around the medial pole of the patella (upto its superior border);
- retract the patellar tendon and the patella laterally so that the femoral trochlea is exposed;
- use flouro to mark out the center of the proximal fragment (AP view);
- direct the awl (or starting reamer) just in front of the trochlear surface;
- direct hand held reamers parallel to the anterior tibial cortical surface down to the frx site;
- take care that the jig apparatus does not injure the trochlear chondral surface as the nail is driven down;
- always drain the arthrotomy site;
- references:
- Semiextended position for intramedullary nailing of the proximal tibia. P. Tornetta MD and E. Collins MD. CORR No 328. 1996. p 185-189.
- Entry Point:
- entry point lies along long axis of the tibia on anterior edge of tibial plateau;
- in the report by P. Tornetta et al (Orthopaedic Trauma Association, 1999), the authors note that the anatomic safe zone (lies on the lateral plateau between the medial meniscus
and the lateral meniscus;
- the authors correlate this anatomic landmark with a radiographic landmark;
- the authors noted that on AP radiographs the safe zone was in line with the medial aspect of the lateral tibial spine;
- on the lateral radiograph, the starting point is located at the anterior margin of the articular surface;
- in the follow up report by Timothy McConnell et al., the authors wished to identify the radiographic correlate of
the anatomic safe zone for tibial portal placement;
- safe zone for tibial nail placement as seen on radiographs is just medial to the lateral tibial spine on
the anteroposterior radiograph and immediately adjacent and anterior to the articular surface as
visualized on the lateral radiograph;
- ref: Tibial Portal Placement: The Radiographic Correlate of the Anatomic Safe Zone. Timothy McConnell et al. J Orthop Trauma 2001 March/April;15(3):207-209
- using the universal Chuck with T handle or a cannulated power drill, insert 4.0 mm Centering Pin thru the proximal metaphysis and into
the meduallary canal, just posterior to the anterior cortex and closely approximating the 9 deg angulation of the tibial nail bend;
- a sterile nail may be held anterior to the tibia to act as a guide for placement of the centering pin;
- note: w/
proximal tibial fractures the nail insertion site is critical;
- insertion site needs to be more lateral than is usual, inorder to avoid a valgus deformity and needs to be inserted more posterior
than is usual, inorder to better direct the nail down the center of the meduallary canal of the proximal fragment;
-
pearls:
- hyperflexion of the knee actually makes the nail insertion more difficult;
- have the patient's leg resting on several "bumps" so that the tibia is elevated and knee is flexed about 45 deg;
- mid flexion of the knee allows enough room for nail entry and does not cause excessive patellar tendon
tightness (which can deflect the nail when the knee is placed in full flexion);
-
hazards:
- be careful to avoid placing the entry point so far posterior that it enters the joint;
- ref: Proximal entry for intramedullary nailing of the tibia. Thr risk of unrecognised articular damage P. Hernigou, D. Cohen. J Bone Joint Surg [Br] 2000;82-B:33-41.
- Cannulated Cutter:
- pass the 11.0 mm Cannulated Cutter and Protection Sleeve over the
centering pin with the longer cutting edge positioned posteriorly;
- oscillate the cutter around the pin to carve an opening thru the
metaphyseal bone and into the canal;
- alternatively use the 13 mm Cannulated Drill Bit over the 3.2 mm guide wire from
Titanium Unreamed Femoral Nail Standard Insertion and Locking Set, or use a
smaller cannulated drill from the ACL reconstruction set;
- initially the reamer is directed posteriory, however, as it is advanced, its direction is
changed from posterior to anterior in order to end up within and parallel to the
meduallary canal of the shaft;
