View of Use of Blocking Screws in Supplementary Way to Interlocking Nail in the Management of Non-Diaphyseal Tibial Fractures

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5962 http://annalsofrscb.ro

Use of Blocking Screws in Supplementary Way to Interlocking Nail in the Management of Non-Diaphyseal

Tibial Fractures

Eslam Eid Abdel-Mohsen¹, Abdallah Attia Mohammed², Riad Mansour Megahed³, and Mohammed Abdel-Fattah Sebaie ⁴

1 Orthopedic Surgeon at Egyptian ministry of health;

2 Professor of Orthopedic Surgery, Faculty of Medicine, Zagazig University.

3 Professor of Orthopedic Surgery, Faculty of Medicine, Zagazig University.

4Assistant Professor of Orthopedic Surgery, Faculty of Medicine, Zagazig University.

Correspondingauthor:Eslam Eid Abdel-Mohsen Email:[email protected]

Abstract

Background:proximal and distal fractures of tibia tend to undergo malalignement when treated with intramedullary nails or functional braces. Blocking or “Poller” screws are a particularly useful technique to help guide the nail correctly. This technique involves placing a blocking screw, drill bit, or K-wire to force the reamer and then the nail into the proper path.

Aim of the study: The aim of this study wasto evaluate the role of blocking (poller) screws in preventing malalignment after interlocking nailing of non-diaphyseal tibial fractures.

Patients and methods:12 patients suffering from metaphyseo – diaphyseal tibial fractures were treated by intramedullary nailing with blocking screws in Department of Orthopeadic surgery at Zagazig University and el Zaitoun Specialized Hospital.Fracture classification was done according to AO surgery reference and of soft tissue injury according to Tcherne classification for open fractures. Following removal of sutures (2 weeks), patients were seen in the clinic every month until union was achieved clinically and radio graphically and after the union, they were also seen at 6 month.

Results:Two of the twelve patients had postoperative fracture varus angulation that was less than 5°, they had score excellent, and one patient had postoperative valgus angulation of about 3° who achieved score good. Healing time was affected by some factors that causes delayed healing time (22-24 weeks). All the twelve patients (100%) achieved union at average time twenty weeks (ranging from 16 to 24 weeks). Five patients showed delayed union 24 weeks, 2 patients were over fifty years showed complete union at 20 and 24 weeks respectively. Delayed union was not related to the technique of poller screws or the concept itself as all the other younger patients or medically free patients healed at shorter time with no complications.

Conclusion:This study demonstrated that the overall results of our patients were studied in correlation to Olerud & Molander score, where we have 5 cases having excellent score (42%) & 7 cases have good score (58%). There is some factors that affect the overall result of our cases as type of fracture, smoking, mode of trauma, patient general condition, type of intramedullary nail used and its application, postoperative range of motion of knee and ankle joint.

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Keywords:Non-diaphyseal Tibial Fractures,Blocking Screws, Interlocking Nail.

1. Introduction:

It is well known that proximal and distal fractures of tibia tend to undergo malalignement when treated with intramedullary nails or functional braces. Intramedullary nailing for metaphyseal tibia fractures with short proximal and distal fragment is associated with frontal and sagittal plane malalignment. This may be attributed to an inaccurate entry site, displacing muscular forces and residual deformity along with discrepancy between voluminous area of the metaphyseo-diaphyseal junction and size of nail(1)(2) .

The high rate of malreduction has led some surgeons to recommend percutaneous plating for its relative technical ease in comparison to proximal nailing, and outcomes for plating and nailing of proximal fractures appear to be similar(3).

The typical deformity present is valgus and apex anterior (procurvatum).The valgus is typically created by using too medial starting point that creates an initial reaming pathway which runs from too medial to lateral.(1) Once the nail is placed, this tips the fracture into valgus.Similarly, the apex anterior deformity is created by the pull of the extensor mechanism and is worsened by an initial reaming path that is angled too far posterior which produces the deformity once the nail is introduced.(1)

Several reports describe techniques to overcome this tendency to malreduce proximal tibia fractures with a nail and have demonstrated relatively low malreduction rates (4)(5).

The use of an ideal starting point and starting wire direction is particularly important for proximal fractures for reducing the fracture before reaming(6).

There is an interest in the use of the suprapatellar starting point for proximal fracture patterns. This is thought to be beneficial because the ideal starting point and reaming path are not blocked by the patella as they are in more traditional approaches. Further, nailing can be performed in a more extended position where the pull of the extensor mechanism is less of a deforming force(7)(8).

Other techniques to prevent malreduction include the use of percutaneous clamps .Provisional plating with unicortical screws has also been described. The use of a femoral distractor or an external fixator can be helpful to hold the fracture in a reduced position while nailing(9).

Blocking or “Poller” screws are a particularly useful technique to help guide the nail correctly.

This technique involves placing a blocking screw, drill bit, or K-wire to force the reamer and then the nail into the proper path(10)(11).The screw can be left in place to increase stability which may be particularly useful in geriatric fractures with wider tibiae and poorer bone quality(11)(10).

The screw is typically placed on the concave side of the fracture or where we want to prevent the nail from being located(11)

The above techniques are all useful to avoid malreduction. Once the error has been made and a

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nail pathway has been established with a nail in place, the deformity can be difficult to correct.

Often, removal of the nail and insertion of blocking screws with subsequent reaming of a new pathway is the most straight forward technique to create the correct pathway for reinsertion of the nail(6).For distal fractures, are also prone to malalignment because the metaphysis is much wider than the diameter of the nail and care must be taken to avoid malunion as this may lead to a worse functional outcome(12)(13).

The keys to avoid malalignment distally are ensuring the guidewire is placed centrally on both the AP and lateral images (the “center-center position”) and keeping the fracture well aligned during reaming and nail insertion(13).

In the absence of metaphyseal cortex contact, the nail may translate along interlocking screws, owing to the play between screws and the nail holes. This can be limited by the use of blocking or Poller screws(14).

The blocking screws are placed so as to effectively reduce the size of the medullary canal either proximally or distally and thereby guide both the guide wire and the nail into an acceptable position. They can be placed in any plane but are usually placed either the sagittal or coronal planes(14).

The Poller screws have been used to guide the nail in the desired central position before inserting the interlocking screws. However, it has been observed that the Poller screw functions like stabilizing device for the nail and fracture(15)(16).

We aimed in this study to evaluate the role of blocking (poller) screws in preventing malalignment after interlocking nailing of non-diaphyseal tibial fractures.

2. Patients and Methods:

2.1. The current study was conductedfrom November 2018 to July 2019, 12 patients suffering from metaphyseo – diaphyseal tibial fractures were treated by intramedullary nailing with blocking screws in Department of Orthopeadic surgery at zagazig university and el Zaitoun Specialized Hospital after obtaining the approval of the institutional review board (IRB) of Zagazig University.

2.2. A consent form approved by the committee of human rights in research in Zagazig University was obtained from each participant before the study initiation.

2.3. Patients who were included in this study who haddistal tibia lmetadiaphyseal fractures, proximal tibia lmetadiaphyseal fractures and who were skeletally mature.

2.4. All patients who had proximal and distal tibial articular fractures, open fractures except gustillo type 1 & 2, and who had pathological fractureswere excluded from the study.

2.5. The patients who met the inclusion criteria and were suitable candidates for the study have

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been subjected to:

Complete personal history: name, age, sex, occupation, marital status and residence.

Musculoskeletal Examination:

Examination of the spine, knee, Ankle, pelvis and calcaneus are very important for associated injury.

Local and Neurologicalexamination.

• Peripheral pulse for Dorsalis Pedis & posterior tibial artery.

• Neurological examination: Motor power for ankle &big toe dorsiflexors, evertors and plantar flexors - Sensory examination for deep peroneal nerve, superficial peroneal nerve, sural nerve, tibial nerve and saphenous nerve.

Radiological and laboratory examination:

Plain X-ray and CT scan of knee if suspected intra articular fracture extension

CBC, Renal function test, Liver function test, Random blood sugar, Prothrombin time, activity ad INR, and HCV & HBV

Preoperative planning

In our study; 6 patients underwent spinal anesthesia, 3 patients underwent epidural anesthesia and 3 patients underwent general anesthesia and all were after the anesthesiologist team recommendations according to the general condition of the patients or the recommendations of the patients themselves.

Surgical Technique:

Positioning of the patient: supine position on a radiolucent fracture table with a pneumatic tourniquet applied to the proximal thigh, then sterilizing and drapping the limb in sterile position.

A transpateller approach was used for nail insertion.

The starting point was obtained using an awl with fluoroscopic guidance Figure (23) just medial to the lateral tibia spine on the anteroposterior (AP) fluoroscopic image (ensure appropriate rotation using the fibular bisector line (overlap of the lateral border of the tibia bisecting the fibula head) and just anterior to the articular surface on the lateral fluoroscopic image “flat plateau”. The flat plateau lateral view lines up the posterior aspect of the femoral condyles

Figure (1): Fluoroscopic (A) AP & (B) Lateral view of the knee shows the starting point.

Obtaining the correct starting point was important for nailing proximal tibia fractures for two

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reasons as shown in Figure (24). First, just as in standard nailing for tibial fractures, we avoided damage to the intraarticular structures. Second, obtaining appropriate intraoperative fluoroscopic images was important, because a slight external rotation of the proximal tibia when obtaining fluoroscopic images of the starting point can result in a misleading medial entry point, which may accentuate a valgus deformity.

Figure (2): The accurate entry point for ILN tibia.

The starting point is localized and confirmed fluoroscopically with either an awl or with a guide pin that can be enlarged with a cannulated drill or awl. Care was taken to avoid injury to the skin, meniscus, patella, and the cartilage of the femoral condyle during initial awl insertion and instrumentation of the tibia.

Fracture reduction:

Closed reduction of tibial shaft fractures was performed by longitudinal traction and correction of translational and angular deformities under anesthesia. It is predicated on the concept of restoration of length, alignment, and rotation with stable fixation.

The traditional method of nailing tibia fractures, regardless of location of the fracture, has been to nail in flexion. Hyperflexion of the knee allows accurate placement and alignment of the guidewire in the sagittal plane, nearly parallel to the anterior cortex.

For nailing of proximal tibia, flexion was limited to approximately 15 degrees to neutralize the force of the extensor mechanism on the proximal tibia leading to an apex anterior deformity, and to relax the tissues allowing for easier instrumentation in proper alignment. The slight flexion allowed access to the proximal tibia to obtain the correct starting point. This was done with small radiolucent bump or triangle under the knee, which allows for slight flexion. In addition, the use of an elevated radiolucent leg ramp elevates the injured extremity above the contralateral leg, making intraoperative fluoroscopy easier.

This point likely led to modifications to the implant system and surgical technique to accommodate nailing in the semi extended position, making it easier to keep the fracture reduced while reaming and during passage of the IMN.

Fracture was reduced before canal preparation (reaming) and implant placement. For proximal diaphyseo-metaphyseal tibial fracture, it was in need for reduction techniques to balance apex anterior deformity (procurvatum) and valgus deformity which were the most common occurring

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deformities while reduction and fixation.

Blocking screw was used as a reduction technique to avoid malalignment. It was placed either before nail insertion if malalignment was suspected as in long spiral fractures, very proximal or very distal fractures with wide voluminous metaphyseal region, presence of comminution or according to intra operative preference.

It was also placed after malalignment with ILN but necessitate removal of the nail & re reaming then nail insertion. Ideal time for blocking screw placement was before reaming and placing the nail that shorten the time of operation. It was also used to enhance construct stability in metaphyseal fracture with poor bone quality or comminution.

It was larger screws or the systems interlocking bolts, because smaller screws (≤3.5 mm) may bend or break under load caused by weakening if a portion of the screw is reamed.

Several nailing systems have targets for placing blocking screws.

Watching carefully under fluoroscopy & consider placing the blocking screws at least 1 cm away from fracture were important notes to minimize the risk of fracture propagation.

Because of the cavernous proximal tibia and the typical deformity associated with proximal tibia fractures, blocking screws, also referred to as Poller screws, have been used to decrease the effective size of the proximal tibia, thus controlling the IMN path in the proximal tibia and helping to mitigate potential malalignment.

Blocking screws were always placed on the concavity of the deformity (One rule of thumb is to apply the screws on the concave side of the deformity). For proximal tibia fractures, which have a typical apex anterior and valgus deformity, the blocking screws were placed lateral and/or posterior to the nail in the proximal segment.

There was another technique for accurate placement of blocking screw. We draw a line down the long axis of the displaced, flared segment of bone. Then we draw a second line along the plane of the fracture, ensuring to bisect the first line & identify the acute angles. Place the screw in the acute angle of the metaphyseal or flared segment.

Insert the guide wire under fluoroscopy guidance, ensuring the tip passes the correct side to ensure reduction. Insert the nail, which was deflected on engaging the screw providing reduction and compression at the fracture site.

Fracture distal tibia associated with a fibular fracture (3 cases) and loss of the “lateral” column support.When the fibula is fractured, open reduction and internal fixation is an effective technique to restore length and alignment. This is generally done through a separate lateral incision and, can be done using plates or an intramedullary device. It is recommend using "flexible” implants to avoid malreduction of the tibia.

Fixation of fibula was done if the fracture was within 7cm of distal fibula (affect ankle stability) or if there was mal reduction of tibial fractures after other reduction techniques.

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Blocking pins and screws also have an important role in providing stability in the distal tibia.It is worth reemphasizing that the guide wire must be in the central portion of the distal fragment in both the AP and lateral views to avoid a translational or angular deformity.

Interlocking screws: For proximal and distal metaphyseo-diaphyseal fractures, we utilized the standard two proximal and two distal interlocks.

For very unstable proximal metaphyseal fractures, or in patients with severe osteoporosis, additional anterolateral to posteromedial oblique locking screw were added. Similarly, in distal tibial fractures, multiplanar screws were placed to enhance fixation stability.

A common mistake associated with the interlocking screws is irritation of the pes anserine or anterior tibial tendons secondary to not fully “seating” the large screw heads against bone.

Another error is syndesmotic irritation from excessively long distal interlocking screws. Both complications can be avoided by careful attention to detail.

Postoperative treatment:

The patients received post-operative antibiotics and the 1^st dressing after three days. Joint mobilization of both knee and ankle joints was started on the second post-operative day and partial weight-bearing was allowed for six to eight weeks. Thereafter, weight-bearing was increased based on the absence of pain and a study of the radiographs (appearance of callus) in follow-up visits.

Isometric exercises started from the first day after the operation. Early active knee and ankle range of motion exercises were encouraged in all patients who were compliant.

Following removal of sutures (2 weeks), patients were seen in the clinic every month until union was achieved clinically and radio graphically and after the union, they were also seen at 6 month.

3. Results:

The twelve patients were followed up in the outpatient clinic for assessment of fracture healing or the establishment of a nonunion.

Union was defined as healing of at least three of four cortices on biplaner radiograph. Nonunion was defined as lack of any healing within 6 months. Malunion was defined as any angular deformity, in any plane, of greater than 5°, translation or shortening greater than 5 millimeters, or rotational malalignment of greater than or equal to 10°.

Delayed union was not related to the technique of poller screws or the concept itself as all the other younger patients or medically free patients healed at shorter time with no complications.

AP and Lateral radiographs were obtained for all cases postoperatively and at each follow up visit. Fracture alignment was determined on each of these radiographs. AP radiographs were used to determine coronal plane deformity (varus and valgus), and Lateral radiographs were used to determine sagittal plane deformity (flexion and extension).

Changes in alignment were noted. Malalignment was defined as more than 5° of angular

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deformity.

Two of the twelve patients had postoperative fracture varus angulation that was less than 5°, they had score excellent, and one patient had postoperative valgus angulation of about 3° who achieved score good (Table 1).

All the twelve patients (100%) achieved union at average time twenty weeks (ranging from 16 to 24 weeks).

Healing time was affected by some factors that causes delayed healing time:

 Four patients less than 40 yrs old healed with average 20 weeks. Expect one patient with diabetes mellitus healed within 22 weeks.

 Two patients from 40 to 50 years old where they are diabetic, and hypertensive healed within 22 weeks while one patient healed within 20 weeks having no diabetes mellitus or hypertensive.

 The last four patients over 50 yrs old healed within 24 weeks two patients of them were diabettc and hypertensive while the other two patients having no medical history (Table 2).

Number and site of the blocking Screws:

i. In the group of the varus deformity, the patient we have treated with IMN and two blocking screws (one medial proximal and other lateral distal to the nail, both in the distal fragment) and this patient also had score excellent.

ii. In the group of the lateral translation deformity, we used two blocking screws lateral to the nail from anterior to posterior in one patient (8.33%) who got score excellent and we used one blocking screw medial to the nail in other two patients (16.67%); of them one (8.33%) got score excellent and one (8.33%) got score good.

iii. In this group five patient with the Valgus deformity, we used one blocking screw medial to the nail from anterior to posterior in two patients (16.67%), the two-patient had distal third tibial fracture, we used one blocking screw medial to the nail in the distal fragment, one patient had score excellent and the other patient had score good.

We used two blocking screws in two patients (16.67%) (One lateral proximal and the other medial distal to the nail, both in the distal fragment). The two patients got scores good. In the last patient (8.33%) we use blocking screw lateral to the nail from anterior to posterior the patient have score good.

In the group of the three patients with the apex anterior deformity in proximal third tibial fractures, we used in the entire three patients (25%) one screw posterior to the nail from medial to lateral in the proximal fragment. one patient (8.33%) had score excellent and two patient (16.67%) had score good(Table 3).

Timing of application of blocking screws:

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We used blocking screws in seven patients before introducing the nail to correct the alignment mainly in patients with apex anterior deformity in proximal third tibial fractures (three patients 25%), two patients with lateral translation deformity (16.67%) and two patients with Valgus deformity (16.67%). Three patients had excellent score (25%) and four patients had good score (33.33%).

We used blocking screws after the insertion of the nail in five patients (41.67%) to improve and maintain the achieved reduction, from these patients; two patients had score excellent (16.67%) and three patients had score good (25%)(Table 4).

Follow up

Patient came to outpatient clinic for clinical and Radiographic follow up to assess maintenance of reduction, limb alignment, re-establishment of bone continuity, loosening of metal and callus formation.

All the twelve patients (100%) achieved union at average time twenty weeks (ranging from 16 to 24 weeks).

Five patients showed delayed union 24 weeks which was related to age and medical history.

Two patients were over fifty years (52 and 54 years) showed complete unon at twenty two and twenty four weeks respectively.

The other three patients had significant medical history; two patients were diabetic and hypertensive and one patient was only hypertensive.

Delayed union was not related to the technique of poller screws or the concept itself as all the other younger patients or medically free patients healed at shorter time with no complications.

Complications.

Complications were divided into BS related and BS unrelated. Potential blocking screw-related complications included mechanical instability leading to a fracture nonunion, new fracture lines through the blocking screw holes, nail failure resulting from drilling-related nail damage, sinking of the blocking screws and blocking screw breakage.

Non BS related complications included all other fracture or intramedullary nailing related complications such as compartment syndrome, infection, rotational malalignment, and interlocking screw breakage, as well as nerve injuries.

In our study, there was one patient had a new fracture line at the site of placement of the blocking screw so we delayed weight bearing and applied a back slab for two weeks then started partial weight bearing. This patient achieved complete union and maintained alignment and according to functional recovery using Olerud – Molander score, he accomplished good score.

Table (1): Post-operative fracture healing Frequency Olerud – Molander

score

Percent Neutral

10 4 Excellent 33.34%

6 Good 50%

Varus 1 Excellent 8.33%

Valgus 1 Good 8.33%

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Total 12 100%

Table (2): Post-operative healing time Healing time

patient age Medical history Percent

20 weeks 5 >40 4

Non 33.34%

40-50 1 8.34%

22 weeks 3

>40 1 Diabetic 8.34%

40-50 2 Diabetic and

hypertensive 16.66%

24 weeks 4 50-60

2 Diabetic and

hypertensive 16.66%

2 non 16.66%

Total 12 100%

Table (3): Number and place of blocking screws No of

patients

No of BS screws

Site of BS screws

Olerud – Molander

score

Percent

Varus 1 1 Double 1 medial

& 1 lateral Excellent 8.33 % Lateral

Translation 3 2 Single medial Excellent 8.33 % Good 8.33 %

1 Double lateral Excellent 8.33 %

Valgus 5

3 Single 1lateral &

2 medial

1Excellent 8.33 % 2 Good 16.67 % 2 Double 1 lateral &

1 medial Good 16.67 %

Apex

anterior 3 3 Single Posterior 1Excellent 8.33%

Good2 16.67 %

Total 12 100%

Table (4): Timing of blocking screws.

Frequency Olerud – Molander

score Percent

Patients with Bs

before nail 7 3 Excellent 25 %

4 Good 33.33 %

Patients with BS

after nail 5 2 Excellent 16.67 %

3 Good 25 %

Total 12 100 %

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Figure (3) shows Preoperative x-ray

Figure (4) Post-operative X ray (AP and Lat view)

Figure (5) last follow up after 24 weeks

4. Discussion:

Proximal and distal tibia is subcutaneous and is prone to trauma and injury. The treatment of extra articular proximal and distal tibia is challenging to orthopedic surgeons due to poor soft tissue coverage , blood supply and malalignment(16). _B

A

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Intramedullary nailing of simple diaphyseal tibial shaft fractures usually results in near anatomic reduction, as the intramedullary nail fills the intramedullary canal. In contrast, the proximal and distal tibial fracture in the diaphysio-metaphyseal region, stabilized with intramedullary nail is associated with a high incidence of malalignment. This has been assigned to muscular forces which displace the fracture and leads to instability. This results due to the play of a nail along the interlocking screws. The contributing factors take account of poor nail-bone contact in the metaphysis when screws are placed in the nails in one plane. The varus-valgus malalignment might follow after screws are generally placed in the coronal plane (4).

Accurate reduction of tibial fractures that are near the metaphysio-diaphyseal junction is notoriously problematic when treated by intramedullary nailing. In the absence of special techniques to achieve and maintain accurate reduction, extra-articular proximal third tibial fractures treated with an intramedullary nail will commonly be malreduced in valgus, apex anterior, and have posterior displacement of the distal segment(13).

Regarding the Poller screw:

Krettek et al.(10)was the first to introduce the technique of using BS to supplement intramedullary fixation of metaphyseal femur and tibia. They prospectively studied 21 fractures of the tibial shaft in 20 patients (12 men and 8 women) with a mean age of 44 ± 17 years (18 to 76).

Pollar screws were selected for use by the surgeon for one or more of the following reasons:

1) To correct alignment after insertion of the nail (7 fractures)

2) To maintain alignment or to improve the stability of the bone-implant complex (21 fractures) 3) To control the nail during insertion (4 fractures).

Our study included 12 patients with metaphysio-diaphysealtibial fractures treated with IMN supplemented with Poller screws. Blocking screws were selected either to achieve alignment before insertion of the nail in 7 fractures, or to maintain alignment or to improve the stability of the bone-implant complex in 5 fractures.

In cases with varus/valgus deformity the screws are placed at concave side of deformity, proximal or distal to fractures. Whenever a second screw is needed it was placed on the convex side of the angulation far from the fracture site in the short segment. While in cases of apex anterior deformity the poller screw was placed posterior to the nail from medial to lateral. A single poller screw was used in 3 cases.

Regarding fracture healing:

In our study, all the twelve patients (100%) achieved union at average time twenty weeks (ranging from 16 to 24 weeks). According to Olerud–Molander score, outcome was excellent in 5 patients, good in 7 and poor in none of the patients. Our study showed comparable results with reported series in literature.

These results were slightly different from the study done by ParthGawatre, et al.,(18) who , found that 27 patients (90%) united in <20 weeks ,one (4%) united betwwen 20_24 weeks and two (6%) united in >24 weeks and fully united in 28 weeks .Their results are superior to the results in this study . This might be due to their use of exppert tibial nail in all cases and the fracture typ difference .

In the series by Kulkarni et al. (13) all 75 cases achieved bone union eventually. In 69 cases,

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healing occurred after a mean of 4.2 months. In 5 cases, there was non-union, which was resolved by bone grafting. One case was mal-united. Sixty three patients had recovered a full range of knee motion (0º–130º), and the remaining 7 patient sustained flexion of 0º to 90º. All patients were able to perform activities of daily living and walk with full weight bearing and without a limp or shortening.According to the knee rating scale of the Hospital for Special Surgery, outcome was excellent in 50 patients, good in 14, poor in 3, and failed in 3 at month 12, and remained so after a mean follow-up of 30.8 months.

Gadegone et al. (18) studied the results of one hundred and twelve patients of distal tibia that involved the distal 6 cm of the tibia treated with reamed intramedullary nailing with use of two distal interlocking screws and one proximal screw in dynamic mode. The augmentation was done with Poller screws whenever it was necessary. The average time to union of the closed fracture was 15.4 weeks. After average follow up of nine months (7 months-18 months) the results were graded according to the criteria laid down by Johner and Wruhs. Their results were excellent in79 cases (70.54%), good in 29 cases (25.90%), and fair in 4 cases (3.56%).

Regarding the Postoperative alignment:

In our series cases of metaphysio-diaphyseal fractures treated by intramedullary nail in combination with Poller screws there were ten cases that showed good alignment with neutral position, while one patient had postoperative fracture varus angulation that was less than 5°, and one patient had postoperative valgus angulation of about 3°.

Similar results were reported in other studies as well. Kulkarni et al. (13) showed the results of seventy five tibial fractures underwent intramedullary nailing supplemented with poller screws.

Postoperatively, 74 cases had <5º of varus or valgus malalignment, and only one developed a varus of +7º. 65cases had no deformity, 7 had a deformity of <3º, and 3 had a deformity of 4º to 9º.

In the study by Gadegone et al. (18), among 112 distal tibia that involved the distal 6 cm of the tibia; the fracture showed varus angulation in seven cases. The angle ranged from 5˚ - 10˚, valgus angulation 6˚ - 8˚ in twelve cases and in three cases recurvatum deformity was encountered but malalignment was under physiological limits and the patients presented at the routine clinic- radiological review.But that did not affect the functional demands of the patients.

Sengodan et al. (14)reported in a prospective study of 20 consecutive cases of distal tibialmetaphyseal fractures treated with statically locked intramedullary nailing with supplementary blocking screw; a mean postoperative varus/valgus alignment of ±1.7 degrees when compared to a mean preoperative varus/valgus alignment of ±10.3 degrees. The alignment was maintained till union with the mean remaining the same in the coronal plane. The mean postoperative antecurvatum/recurvatum alignment was ±0.2 degrees when compared to the mean preoperative antecurvatum/recurvatum alignment of ±8.0 degrees. The mean antecurvatum/recurvatum alignment was maintained till union at ±0.2 degrees. The mean ratio of fracture segment to the nail length (i.e., the length of tibia) was14%.

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Regarding the Postoperative complications:

In our study, there was one patient had a new fracture line at the site of placement of the blocking screw so we delayed weight bearing and applied a back slab for two weeks then started partial weight bearing. This patient achieved complete union and maintained alignment and good score according to Olerud–Molander score.

These results were slightly similar to the study done by ParthGawatre, et al.(18). who found in their study that no cases of chronic osteomyelitis, one case of impant breakage,seven cases of malalignment which was accepted, no cases of nonunion or secondary procedures & three cases of anterior knee pain that interfere with daily activities .

In the study by Kulkarni et al. (13) postoperative complications included anterior knee joint pain in 8 cases, and superficial infections in 4 cases, which was treated with local debridement and use of antibiotic impregnated beads.

5. Conclusion:

This study demonstrated that the overall results of our patients were studied in correlation to Olerud & Molander score, where we have 5 cases having excellent score (42%) & 7 cases have good score (58%). There are some factors that affect the overall result of our cases as type of fracture, smoking, mode of trauma, patient general condition, type of intramedullary nail used and its application, postoperative range of motion of knee and ankle joint.

We have few complications that doesn't dramatically affect our result as mild knee joint pain &

muscle atrophy around ankle joint & decreased skin sensation & colour of skin also delayed union and fracture displacement and this is due to high grade of fracture comminution & incorrect application of intamedullary nail, Therefore, application of blocking screws as a supplement to interlocking nail minimize complication & rate of malalignment that happens with traditional interlocking nailing in an easy & safe way for fixation of these types of fractures..

6. ConflictofInterest:

Noconflictofinterest.

7.References

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