Clinical evaluation of the modified tension band wiring technique for the fractured patella

P.G in Orthopaedics, Navodaya Medical College, Raichur584103, India. Associate Professor of Pathology, Navodaya Medical College, Raichur584103, India. Assistant Professor of Orthopaedics, Navodaya Medical College, Raichur584103, India. Senior resident, Department of Orthopaedics, Navodaya Medical College, Raichur584103, India. Associate Professor of Orthopaedics, Navodaya Medical College, Raichur584103, India. Associate Professor, Department of Forensic Medicine, Ashwini Rural Medical College, Kumbhari, Solapur – 413006, India.


Introduction
Fractures of the patella are common and constitute almost 1% of all skeletal injuries. 1 Opinions differ widely as to the proper treatment of a fractured patella. Haxton 2 in 1945 and Kaufer in 1971 3 on the basis of experimental work showed that the patella was not without importance in the knee joint and was responsible for improving its efficiency. It is because of this that the need to preserve the whole or part of the patella becomes imperative, especially in a country like India where social habits and needs require a full range of knee flexion.

Aims and Objectives of the Study a)
To study the functional outcome by early mobilization. b) To study the complications of tension band wiring. c) To clinically evaluate the tension band wiring technique for fracture patella. d) To assess knee joint motion and stability after the procedure. e) To study the mode of injury for fracture patella.

Materials and Methods
The present study consists of 20 selected cases of fractured patella treated by modified tension band wiring at the Navodaya Medical College, Raichur from July 2011 to October 2013.
The details of the cases were recorded as follows: The name, age sex, occupation, address, family history and past history were noted. The history was elicited from the patients. The nature of trauma, whether due to direct or indirect violence was noted. Whether trauma due to Road traffic accidents, assault, fall in the same plane or fall from a height were specifically asked. Enquiry was made to note pain, swelling its rate of increase and if the patient was able to bear weight on the affected limb and was able to do active movements of the affected joint.
General condition was examined as to his build, nutritional status, the condition of respiratory and cardio-vascular systems and for associated injuries.
IJBAR (2014) 05 (01) www.ssjournals.com  Any local rise of temperature, tenderness over the bone a palpable transverse defect or sulcus, crepitus, fluctuation and broadening of patella. 3. Active extension movements of the affected knee noted & compared with normal side. It was also noted whether the patient was able to stand on his injured limb. 4. The circumference of both the thighs were measured to note any reduction in the bulk of the quadriceps. 5. The other knee joint was examined for comparison and to note any anatomical variation. Investigations: Routine examination of blood and urine were done for haemoglobin percentage, total and differential WBC count, bleeding and clotting time and presence of albumin and sugar in urine and HbsAg, HIV tests.

X-ray Examination
X-rays in lateral and antero-posterior views were taken for confirmation of diagnosis. X-rays in skyline view were taken in cases suspected to have longitudinal and marginal fractures. Treatment: After the X-rays the limb was immobilized by an above knee POP posterior slab. Operations were done at a later date. If abrasions were presents in the skin they were cleaned, dressed and antibiotics given. Patients were prepared for surgery during this period. On the day before the surgery the part was prepared and antibiotics started. Patients were taught static quadriceps drill and straight leg raising exercises.

Operative Procedure
The operation was performed under general or spinal anaesthesia. Tourniquet was applied to the upper part of the thigh and th e part was painted with iodine and spirit and draped. A vertical lazy 'S' incision was put over the anterior aspect of the knee. The skin and fa scia were retracted to expose the fracture site. The knee was flexed to 20 and positioned on a roll. The fractured surface was cleaned of all blood clots. The extent of retinacular tears was explored and the joint inspected for any damage to the femur. The joint was then thoroughly lavaged.
About 5mm from the anterior surface of the patella, one hole is drilled with a 2 mm drill bit, from the fracture surface. A 1.6 mm K wire is inserted in the first hole and is used as a guide to drill the second hole parallel to the first. To ease drilling th e proximal fragment is held with reduction clamps and the fragment tipped so that the fracture surface faces the surgeon. Now the fracture is reduced with reduction clamps. The accuracy of the reduction is checked by inspecting and palpating the a nterior and posterior surface in case of retinacular tear. Now the K wires are removed and two holes are drilled into the distal fragment from the proximal fragment. The drill bit is removed and replaced with 1.6 mm K wires which are hooked at the tip. A 20 gauge wire is passed around the K wire in a figure of 8 patterns so that the eye comes to lie next to the proximal end of the lateral K wire. This facilitates future metal removal. The wire is then tightened with the A.O tightener. After tightening the wire the tightener is tipped 90° and cut about 1 cm l ong and the cut end burried in the soft tissues.
The K wires are adjusted so that the curved ends face backwards, pulled down and hammered into bone. The distal portions are cut off about 1 cm from where they exit from bone. The joint capsule and quadriceps retinaculae are meticulously repaired and the fascia repaired with plain sutures. The skin is closed with interrupted mattress sutures and a compression bandage given.

Post-operative management
The patient is advised to do quadriceps exercises from the first post operative day onwards and is allowed full weight bearing from the 3 rd day after removal of the compression bandage. Later knee flexion was started with the quadriceps board, and continued with th e continuous passive motion machine. The patients were then taught dynamic quadriceps exercises which they could do themselves at home, advised to do them regularly and discharged on the 14 th day.

Follow up
The patients on discharge were advised to report for follow up after 1 month in the first instance and then after every 2 months. During each follow up patients were questioned about subjective complaints like pain, difficulty in walking, squatting, climbing and stepping down stairs and inability to perform normal work.

Observation and Results
Since the advent of surgical treatment of the fracture patella, opinion has changed from one advocating removal of the patella to one preserving either part or preferably whole of the patella. If the fragments can be realigned and fixed in such a way that once it heals, it is in no way different from its pre-fractured status, it would be the ideal treatment. In this series 20 cases of fractured patella were treated in patients between the age group of 20-50 years by the modified tension band wiring technique, special attention was given to mobilize the knee early as it helps to regain the quadriceps power.

Results
 In this study, 12 cases were male and 8 cases were female,.  15 cases were having indirect injury and 5 were having direct injury.  Fourteen cases graded as excellent, 5 cases graded as good and one case as poor. Criteria to grade the cases mentioned below:

Excellent
This knee was functionally normal. The patient has no subjective complaints like pain, difficulty in squatting and climbing steps and objective deficiencies like quadriceps wasting and limitation of flexion and extension and normal quadriceps power.

Good
There was occasional pain. Patient can squat and climb steps with some difficulty. Limitation of flexion less than 20°, quadriceps wasting less than 1 cm, and reduction of quadriceps power from grade-5 to grade-4.

Poor
Cases which failed to attain the above standards.

Discussion
The findings, the end results and various other data was analyzed and compared in the following discussion.

Subjective Complaints following Modified Tension Band Wiring:
In the present study subjective complaints like pain was observed in 6(30%) patients and difficulty in squatting was observed in 6(30%) patients.

Objective deficiency after modified tension band wiring:
In the present study 6(30%) patients had flexion limitation, quadriceps wasting was observed in 6(30%) patients, a quadriceps power of grade IV was observed in 6 (30%) patients. There was no extension lag in any of the cases.

Summary and Conclusions
Twenty cases of fracture patella treated by modified tension band wiring technique at Navodaya Medical College Hospital & Research Centre, Raichur have been presented.
IJBAR (2014) 05 (01) www.ssjournals.com Fractures of the patella are common though rare below the age of 20 years. Fall in the same plane is the most common cause of fractures of the patella. Vertical incision is more helpful to mobilize the patient early. Early mobilization of the knee restores quadriceps power and range of knee motion within a short period. Excellent range of movement was achieved in 70% of cases. Early and continuous physiotherapy following the modified tension band wiring technique is of paramount importance in determining the end results. Modified tension band wiring is therefore the choice of treatment for the fracture patella.